1
48
148
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PDF Text
Text
11 can't
happen to
11
crew in o 767 con do it;
if 134 Rights in Australia
over the lost five years con
terminate due to fuel
exhaustion; if innumerable
other pilots can terri~
themselves, it can happen
to you and you'd better
believe ii. If you're serious
about the flying game, you
know full well that
on~hing con happen.
Your job (yes, 'iob') is lo
cover off every eventuali~
to the best of your obili~ ·
All THE TIME.
..An
aircraft is
an aircraft
is an
aircraft...
II
(or, 'I can lean it out
better than any
book figures').
No matter how many
hours you hove in your
logbook, never forget thot
manufacturers' manuals
ore not written merely to
comply with legal
requirements · they ore
there to point out the
characteristics of the
oircroh in question. Read
and learn before you hire
and Hy!
11'11 be
Aviation
Fuel
lchecked
CAVOK by
fuel's too
gauges
the tanks
the time we expensive, are precise last
• hi...
get to the
and
insbumenb.!' n1g
Yes, well, we oil know the
Good for you! Any reas~}
other
anvway, the answer
to that one don't
why you didn't check them
end... "
perhaps ii ought
this morning? (other thon
i ALA should we?to be(or'shouldn't
we?'). At
ICTilN). lots of things con
(or, 'on the basis of
... be easy to best, o fuel gouge is o happen in the wee small
the forecast, I won't'
fIRd...
very approximate
hours, from venting and
have to hold/ divert';
11
11
11
11
II
II
or 'the headwind
will never be that
strong')
In plain English !or more
properly, Australian). this
implies that you ore putting
your life · and your
passengers lives · on the
line. Are you so confident
of the forecost that you
con trade fuel for freight?
Be aware of the
reporting/forecasting
limitations for your
destination. Hove enough
fuel to divert.
Of course ii isl Bui how
much would you pay for
another ten litres in the
tanks when the gauges
(see next item) read
EMPTY, you're in marginal
VMC and the only place
to go is still (you think)
25 nm away?
analogue of fuel contents.
Agood rule of thumb is to
assume they always over
read. Check fuel
remaining against
published consumption
roles os port of your
normal navigation cycle.
leaks to thievery. Check
contents and carry out o
fuel drain os part of the
first pr~light of the day.
�Aviation Safety Digest is prepared and
published by the Civil Aviation Authority. It is
distributed to Australian licence holders
(except student pilots), registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
Manager, Publications Centre, P.O. Box 1986
Carlton South, 3053, AUSTRALIA
Telephone (03) 342 2000(4 lines); 008 33 1676
008 33 4191; (03) 347 4407
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The articles
are intended to serve as a basis for discussion
and even argument in an effort to identify and
resolve problem areas and potentially
hazardous situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the material without altering
the author's intended meaning.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Telephone (06) 268 4583
Contents
4
Fuel for thought (or vice versa)
7
A challenging comparison
10
Accident response
13
Do you lose airspeed when you
turn downwind?
16 Con~essions of an
(
ICAO airspace -
19
What's the 'arm in it?
20
Low flying
23
Advanced air traffic systems
agreed
a positive view
Roger Marchant
Lyn Coutts
Diagrams:
P20
Kathy Foldszin and Soussanith
Nokham
Cartoon:
P5
Kathy Foldszin
Photographs:
P17
P20
P21
CAA file photo
BAS/ File photos
A. Lang
ISSN 0045- 1207
Printed by Ambassador Press Pty Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
undeserving
18
Covers
Front: Design by Soussanith Nokham CM Design Studio
Back: Design by Andrew Rankine CM Design Studio
INCE 1986, there have been in Australia 75 accidents known to have been caused by fuel
starvation or exhaustion, and a further 17 where these causes were strongly indicated. Of
these accidents, 8 included fatal injuries to at least one of the a ircraft's occupants.
Therefore, in addition to the covers, there is an article in this magazine concerning fuel
management. Please take heed of what it says - there is nothing quite as embarrassing as
hearing a lot of no noise from your trusty Pratt and Whitney or whatever on any occasion except
that of having switched off, parked safely on the aerodrome. Checks before take-off and in-flight
may be a chore, but it's these little things that help to keep us safe in the air - all the time.
Also about fuel: most will know that CAR 234 has been amended to say, in essence (vive
l'essence), that you need only carry sufficient fuel to complete your flight safely. That is, no
fixed, no variable reserves are prescribed for private/airwork category flights. In fact, the fuel
you actually need for the flight h as of course not changed; it is only the emphasis on pilot
responsibility that is enhanced. Clearly, if you come to a grinding halt tangled up in the approach
end fence you probably have not loaded sufficient fuel. Your consequent explanation to the judge
will be interesting, to say the least!
The definition of 'sufficient', in line with the CAA philosophy of deregulation, is left to the
operator. How to defend your idea of enough fuel for the trip is another matter, and in this
exercise help is provided by a new Civil Aviation Advisory Publication (CAAP 234-1(1). This
addresses all matters that have to be considered when calculating fuel requirements. Copies of the
CAAP may be obtained from CAA Pubs Centre, address as in the inside front cover. For
commercial (Air Operator's Certificate) work, the Company Operations Manual containing rules for
fuel has to be approved by the CAA .
As the note at the foot of 'Low-flying' indicates, there have been a fair few losses over the last
half-year. All are tragic, but those suffered by the professional (agricultural/mustering)
community are especially galling, as that group comprises operators who should know all the
risks, assess them and take appropriate precautions.
note: as part of the new airspace arrangements, an amendment to CAR 157 is in preparation
changing the '1 500 feet' to '1 OOO feet'.
I hope Neville Probert's piece on aerodynamics is sufficient to make an end to the argument on the
effects (if any) of turning downwind. But perhaps there are those who would like to offer further
enlightenment?
The survey concerning the possible fate of this publication has generated a welter of response and
we thank our respondents . Our trusty database reveals opinion to be approximately 90% for
continuing publication. In conjunction with other factors, these figures are being taken into
account by those who will make the decision.
On the first yellow page is the result of the Caption Contest. I hope you'll agree that at least a
little of the flavour of aviation has been caught by those chosen. There were around 200 entries,
and here in the office we were able to chortle at some that in no way could have been selected for
printing ...
S
survivor
Editor:
Sub-Editor:
© Civil Aviation Authority 1991
Editorial
�Aviation Safety Digest
Aviation Safety Digest
149
149
Fuel for thought
(or vice versa)
engine stoppages from fuel problems are
so ... ooo final. AND, more than any other type
of accident, they are almost totally avoidable.
BAS! statisticians tell us that every year, in
Australia, 14 major accidents take place as a
result of fuel starvation or exhaustion. What a
waste!
Before we start mumbling that accidents will
happen - that they are an inevitable part of
the human factor in the accident equation let's stop and consider. I'll grant that there are
occasions when a combination of factors,
occuring in the same time scale, can overpower
the pilot's capabilities - but I believe the great
majority of accidents are avoidable even if the
cost of avoiding goes outside other boundaries
set by the participants - money, time, willingness, greed etc. Fuel related accidents, however,
usually involve fewer factors, most of which
are early indicators to the pilot and, if acted
upon, can save the day.
The power / fuel mixture setting used was on
the high side of normal. After two-thirds of
the planned flight, the pilot became concerned
about his rapidly diminishing indicated fuel
resources, and planned one diversion, then a
further one as his concern increased. The
engine stopped in the circuit area of t he second
selected airfield, and the aircraft was seriously
damaged when unable to make it to the strip.
• On returning to land from an instructional
flight, the student was asked to select another
tank, but because of inexperience , shut off the
fuel when he moved the selector to a position
without actively seeking and finding the
detente position.
()
.
I
Mark Perrett, FOl(GA)
Definitions
Fuel exhaustion: no fuel left in the tanks
Don't think it couldn't happen to you!
Fuel starvation: fuel in the tanks but for some reason,
usually finger-trouble, not available to the keep the engine
running.
Let's look at some of the accident stories. Our
list of involuntary contributors to this article
ranges from student pilots to senior commercial
GA pilots, even up to the captain of a Boeing 767.
• A Boeing 767 had an unserviceability in its
main fuel quantity indicating system, but government approval was available for the aircraft to be flown on scheduled operations. The
aircraft was refuelled using dipstick and calculations. Because of errors made using conversion factors required for the calculations,
only half the fuel required was added. En
route, both engines flamed out. Only the fortunate coincidences of the pilot's being a practising glider pilot and the proximity of a large
disused airfield averted a major disaster.
• On the third take-off of the morning by an
agricultural aircraft, the engine failed just
after lift-off. As not enough time was available to select the alternate tank and restore
fuel to the engine, the aircraft was severely
damaged during the ensuing emergency landing. The aircraft had been refuelled the night
before by 'other persons', but not to full. The
fuel gauges were inaccurate, and very little
fuel had been contained in the tank initially
selected. The audible low fuel warning was
not operational.
• A charter could not be fully refuelled because
of the proposed load. The high-wing aircraft
carried neither a calibrated dipstick nor a ladder, and an accurate visual assessment of fuel
contents was difficult. A small amount of fuel
was added, bringing the fuel up to an estimated 240 minute level for a 180 minute
flight.
TLAR: 'That looks about right'
W
E ALL have a hoary old instructor, complete with wise sayings, somewhere in
our aviation background. The one in
mine (G'day, Jimmy) once pronounced on 'the
three things most useless to a pilot'. They were:
- the runway behind you;
- the height above you; and
- the fuel you used to h ave [or didn't load ].
I've tried to fly, and live, by that advice since.
Those of you VIC/TAS Safety Awareness Seminar groupies who are reading this will, I hope,
recall the spectacle of me ranting about fuel
management and the utter wastefulness of t he
fuel exhaustion/fuel starvation accident. The
good news is, that's what I'm going to talk
about again, and the bad news is, they' re still
happening.
Exhausting all the fuel in an airborne aircraft,
or being µnable, through mishandling or lack of
time, to get access to fuel on board, is aviation's
equivalent to the heart attack, and concludes
with the same sort of results. By awareness and
a healthy lifestyle, we can stave off, if not
eliminate, ticker trouble; with good fuel management we can do even better in the operation
of aircraft.
Why the song and dance? Well, you may or may
.1ot have first hand experience of this, but
0
J 1U
• The aircraft departed with an estimated
endurance of 430 minutes. During the return
flight, the pilot decided to continue to a
further field, a considerable dist ance beyond
destination. When preparing for a precautionary landing because of low fuel indications,
the engine stopped. In the forced landing, the
aircraft overturned, with substantial damage.
The aircraft had been airborne for a total of
366 minutes. On planned fuel usage, landing
at the revised destination would have been
well inside the fixed reserve.
Discussion
A BASI study covering an eighteen-year period
drew a number of interesting conclusions:
43% of all fuel exhaustion occurrences resulted
in accidents, as did 19% of fuel starvation
occurrences. Also, 62% of fuel exhaustion
occurrences forced pilots to land off-airfield.
The major factors contributing to accidents were:
- miscalculated consumption;
- poor in-flight decisions;
- inadequate pre-flight actions; and
- mismanaged fuel.
[note that some of these factors may seem to be
very similar, but if you think about it each f actor is really quite discrete - edj
30% of all fuel starvation cases occurred during
take-off or landing, and 22% (including 3% on
take-off!) of all exhaustion cases did, too.
Fuel exhaustion accients/ incidents occurred
mostly in WA, followed by NSW, QLD and
SA/NT, with VIC/ TAS least.
In fuel exhaustion cases, pilot factors were
involved in 89%, and in starvation cases 45%.
With the exception of a small hump in the 100300 flying-hour group, fuel exhaustion accidents occurred across the spectrum of flying
experience, but by far the largest percentages
of occurrences involved those with less than
100 hours on type .
60% of all fuel exhaustion cases happened on
private/ business flights.
In aircraft factors, 48% of fuel exhaustion accidents were associated with fuel inst rumentation, and 43% were related to tanks,, vents,
and drains.
Most needless occurrences arose from either
failure to perform physical checks before flight
or determination to continue flight with low
fuel indications.
Other common elements are:
- failure to appreciate the hazards and consequences of fuel stoppages;
incorrect results from using fuel conversion
calculations; and
scepticism regarding fuel contents gauges.
To attempt to discuss all of the conclusions I
have listed would fill this magazine. I have presented them as seen in the hope they will generate consideration and discussion within your
aviation group. Even so, a number of recommendations suggest themselves, both in general
terms and in regard to various phases of
flight.
General Recommendations
Always cross-check your fuel amount by at
least two separate methods.
Do your utmost to ensure correct calculations of
fuel required - use tables or visual diagrams
in preference to calculators.
Constantly monitor fuel status in flight. Use a
system, and record all y our fuel management
actions.
Take pains to understand fully the management
of your aircraft's fuel system, and apply that
principle to pilots you supervise.
If you have any influence over biennial flight
reviews, make sure they cover fuel management
knowledge, including:
working the system;
- calculation of range and endurance (what's
the difference?);
- in-flight calculations result ing from
diversions; and
- the ability to determine fuel state at an y
stage of flight .
We can summarize what has been covered by
making a list of items to consider when planning a flight.
Pre-flight planning
Use accurate fuel planning figures . Your school
or provider organisation should keep up-to-date
fuel consumption records for each aircraft.
Beware the use of 'standard' figures such as
240, 300, or 360 minutes - calculate, calculate,
calculate!
..•
�Aviation Safety Digest
149
Selectively use the fuel block on the flight planning form for planning your fuel consumption.
Remember, a considerable amount of extra fuel
is used for start-up, taxi, run-up, take-off,
climbing and then manoeuvring prior to actual
departure.
Know and use the maker's/operator's instructions for the determination of fuel necessary
for the cruise segment of your trip.
Make it a rule to set out on even the shortest
cross-country flight with full tanks, for you
never know when or where you might have to
divert. Plan to arrive at your destination with
at least 45 minutes reserve fuel. That is for use
if you are delayed unexpectedly in making your
landing approach and NOT to be used as an
en-route reserve if you encounter un-forecast
headwinds. In other words, accept the administrative problems associated w ith a prudent
diversion to an alternative aerodrome. Being
safety-conscious does not mean you're a wimp!
Preflight inspection
Visually check the fuel amounts in your tanks.
If at a ll possible, use a dipstick, but beware of
inaccuracies of calibration or in the way you
use it.
If, in calculating fuel amounts by differing
means, you come up with more than 3% difference, accept the lowest figure.
Ensure absolute accuracy of 'fuel required' figures; check carefully conversions/calculations.
Ensure fuel filler-cap security AND seating.
(Siphoning from a loose cap can rob you of
most of your fuel.) Ensure drains and vents are
working correctly.
Refuel on level ground - obviate inaccuracy
and/or unwanted transfer.
Satisfy yourself as to the quality of the fuel
(water etc).
Rock the aircraft to rid the tanks of trapped air.
AviationSafety Digest
149
Treat fuel gauge readings with suspicion!
Cross-check the readings with another method
(e.g. fuel flow x time). Learn the use of
'howgozit' graphs. Always believe the lower
figure. That is, if cross-calculation tells you the
gauges are over-reading, believe the calculation,
(but re-check). If the gauges read less than you
calculate you have, believe the gauges, because
birdstrike, structural weaknesses, siphoning
and venting can all cause unexpected loss of fuel.
Develop a system whereby at each reporting
point or, say, every 30 minutes, you make a
positive check of fuel remaining against time
airborne, taking into account altitude and
mixture.
()
A challenging
comparison:
Also, we have to use the term 'commercial pilot'
generically. The U.S. has only one class of commercial licence, whereas we have two. Airline
pilots are excluded from t his comparison
because they all have instrument ratin,gs.
Instrument-rated pilots in 4ustralia and
USA
Despite these problems, it is true to say that
smaller percentages of Australian pilots h ave
instrument ratings compared with their American counterparts. But the whole truth is more
complex than that.
Robert Phillips, Research Section
Standards Development, CAA
ONCERNING instrument rated pilots in
Australia and the United States:
C
Conclusion
• Do we have a smaller percentage of instrument rated pilots in Australia compared with
t he US?
• If so, does this mean that it is harder to get
an instrument rating here?
• And does this also mean that aviation is more
dangerous in Australia because we make it
harder to get an instrument rating?
In trying to answer t hese questions, we must
mak e international comparisons. But, a s this
paper will show, comparing data (especially
statistics) from different countries involves a s
many pitfalls as, say, t rying to fly VFR in IMC.
I realise, if you are reading this, you probably
belong to the converted, but I urge you in any
case to help spread the word. Too many people
become statistics for us to revert to the TLAR
method of fuel management. In the aviation
world's drift into de-regulation, more and more
onus is devolving on to individual pilots. Under
the CAAP system, we may expect a change in
fuel management regulations. Then, what I am
saying here will become even more important.
Statistics on instrument ratings
Never, ever, put yourself
in the position of
desperately wishing for
the fuel you used to
have, or could have
had!
To begin with, we can only sensibly compare
fixed-wing pilots in Australia and the United
States. It is very difficult to compare other categories of pilots because of different requirements and classification systems in the two
countries. So for 'pilots', read 'fixed-wing
pilots'.
REQUIREMENTS
NOTE:
The very useful article Time In Your Tanks,
was re-published in AOPA magazine, February
1988. It is recommended reading!
ASD commends this article, and, noting that
the introduction and discussion are interesting,
asks that you read carefully the general recommendations and really try to follow each various 'ensure', 'monitor', 'beware' and 'check'. At
least, you will have then done all you can to
guarantee fuel to the carburettor, injector or
nozzle.
The best generalisation one can make is that,
compared to an Australian pilot, an American
private pilot is three to five times as likely to
have an instrument rating.
Why is this so?
Could it be due to tougher requirements for
obtaining a rating in Australia, compared to
USA? Perhaps it's the weather, or it all could
be due to other factors.
The answer is that all of these are relevant.
Instrument rating requirements
The attached table outlines the requirements
for obtaining an instrument rating in t he United
States as per FAR 6 1.65, and for the Australian
Command Rating under CAO 40.2.1.
50 hours
50 hours
20 hours
20 hours
20 hours (implied)
20 hours
20 hours (implied)
15 hours, at least 5 in an
aeroplane or helicopter
20 hours
10 hours
Minimum instrument time requirements
55 hours
40 hours 3
Night flying
May be included
in private licence training
1O hours, at least 5 of
wh ich as pilot-jn-command
for appropriate aircraft
category
Total minimum time from ab-initio 4
125
approximately 125
• maximum on synthetic flight (ground)
trainer
• minimum on aircraft category for which
rating is required
• minimum hours cross-country
• dual instrument flight instruction
u
In Australia, pilots can also hold a night VFR or
copilot IFR rating, usually the former. In USA,
in order to have a ' Night Flying Prohibited'
endorsement removed from their licences, private pilots are required to do three hours night
flying under tutelage, including ten take-offs
and landings. However, there are no American
statistics from which to make a comparison
with Aust ralia on night VFR priv ileges.
INSTRUMENT RATING REQUIREMENTS : US -v- AUSTRALIA
UN ITED STATES 1
AUSTRALIA 2
Cross-country as pilot-in-command
Instrument time
In flight
Use a comprehensi\'.e fuel log, taking into
account quantity and tank selection. Calculate
the effects of changed ETAs and changed
engine power configurations.
Make proper use of the mixture control.
Reip.ember, various leaning procedures exist for
the cruise ('best power', 'range' and 'endurance') and consumption figures for these are
markedly different.
Use the correct cruise power settings, derived
from the maker's manual or the company operations manual.
16% of America's private pilots and 85% of its
commercial pilots have instrument rat ings. By
contrast, only about 3% of Australian private
pilots, and about 40% of commercial pilots hold
command instrument ratings.
1.
2.
3.
4.
Instrument rating requirements as per Federal Aviation Regulation Part 61.65
Command Instrument Rating requirements as per Civil Aviation Orders Part 40.2.1
May be reduced to 30 hours for an instrument rated training course of integrated ground and air training , as per CAO 40.2.1.8.4
Does not appear to include flight test times
j
�Aviation Safety Digest
149
Aviation Safety Digest
149
From the table, it is clear that the requirements
are similar. The minimum flight time, simulator
time and cross country time are similar, and the
American system actually requires more instrument hours . In both countries, the minimum
time ab initio to obtaining an instrument rating
is about 125 hours, not a llowing for flight tests.
It seems, therefore, that our system does not
make it harder for a private pilot to obtain an
instrument rating, and may actually make it
somewhat easier.
In the American system, instrument ratings are
issued in perpetuity, whereas in Australia they
have to be renewed annually and lapse
altogether if not renewed within two years.
However, the US recency requirements are
more stringent than ours. In Australia recency
may be retained by completing just one hour of
t he appropriate kind of flying every ninety
days; in US six hours of such flight is required
every six months.
Therefore, w ith regard to comparative statistics, the US instrument rating system has
greater scope for 'dormant' ratings. A pilot with
a rating may not have obta ined recency for several years, but will still appear as a statistical
entity. In Australia 'dormant' ratings would
cease after two years following expiry date,
and be removed from the stats. Therefore, in
terms of 'active' r atings the US percentages of
instrument-rated pilots may be inflated compared to Australian figures.
By contrast, in more densely populated areas
(by people, airports and aircraft), there are
likely to be more IFR operation s. This is partly
because of greater traffic density, controlled
airspace, radar coverage and availability of
navaids .
The other major cause is pollution. The densely
populated areas of North America generate
enough smog, fog and haze to create conditions
that are frequently marginal or unsuitable for
VFR operations. Pilots in t hese areas tend to get
instrument ratings. In Australia, the situation is
somewhat different. Pollution in the Sydney
and Melbourne areas may be an incentive for
pilots to get instrument ratings. But two-thirds
of the country is even less densely populated
than Alaska. Thus there are many VFR operations into remote landing strips at mines,
cattle stations and so on. Furthermore, pilots
can expect VFR conditions for at least 330 days
per year. The terrain is generally flat. Railway
tracks, roads and other landmarks are rarely
covered by snow or forest, and t he nearest
navaids may be hundreds of miles away. In
such conditions there is little incentive to get an
instrument rating.
To summarise, the relationship between
weather conditions and a pilot's propensity to
obtain an instrument rating is not a simple one.
Nor does weather seem to account for all
regional variations in percentages of instrument
rated pilots. It is clear that some other factors
are involved a s well.
Weather
People often assume that weather is a major
factor in persuading pilots to obtain instrument
ratings. That is, more pilots obtain instrument
ratings in a country like the USA simply
because the weather is generally worse there
than in Australia.
If weather is the determining factor in p ilots
obtaining instrument ratings, then we might
expect t hose areas of the US that have the
worst weather conditions to a lso have the
highest percentage of instrument rated pilots.
Yet it turns out that those r egions of the United
States where we would expect to find t he worst
weather conditions - Alaska and North West
Mountains (the Rockies), have the lowest percentages of private· pilots with instrument
ratings (7.39% and 13.26%) and the lowest a nd
third lowest for commercial pilots (82.25% and
81.93%).
Au stralian pilots who have flown in North
Ame rica have pointed out that in remote areas
such as Alaska, North ern Canada, the Rockies
and the Sierras, many operations are better
suited to VFR than IFR flying.
Reference to visua l landmarks must be ma intained, for examp le, w hen flying through steep
mountain passes or landing in remote locations
su ch as mining, timber or hunting camps. In
~iany cases you fly VFR or you don't fly at all.
Navaids
The region with the highest percentages of
instrument rated pilots in the U.S. is the Eastern seaboard, around Washington and New
York (18.4% p rivate and 89.5% commercial).
This is a lso the area with the highest concentration of radio navigation aids (average distance between n avaid locations= 30.2nm) and
presumably the greatest amount of air traffic.
It is clear from examining Jeppesen charts for
the United States and statistics on percentages
of instrument rated pilots by region t h at t hose
regions with the highest density of navaid
locations (mainly in the east and south) h ave
higher percentages of instrument r ated pilots
than where navaids a re sparse (cent r e, northwest and Alask a).
By examining navaid locations on Australian
ERC(L) charts, it is clear that the concentration
of navaid locations in Australia is considerably
less than in the United States.
The average dist a nce between navaid locations
in Australia (91.4nm) is in fact greater than in
the Arctic st ate of Alaska (61.8nm). Since only
7.39% of Alaskan private airplane pilots have
instrument r atings, th e corresponding Australian figure of 3. 15% compares reasonably well.
In general, it would seem that the more navaids
av ailable, the greater t he propensity for pilots
to obtain instrument ratings. This is partly
because they don't have to fly as far afield to
do their instrument t raining. A case, perhaps,
of supply influencing demand.
0
Perhaps in Australia a smaller percentage of
pilots who hav e such commitments fly for
business/ commercial purposes. And even for
those Australian pilots whose time is precious,
t he clear azure skies for which th is country is
famous may be a disincentive to gaining an
instrument rating.
Controlled airspace
..
Navaids tend to be concentrated in those areas
that are densely populated by people, airports
and aircraft. These are the areas of controlled
airspace, with radar coverage and direction by
air traffic control. The advantage of flying IFR
in these areas is that the aircraft has a t ransponder frequency (and individual code in
North America). The aircraft is being monitored
by ATC radar and the pilot feels safer; in fact,
IFR aircraft often r eceive priority over VFR aircraft at major airports. For example, at Toronto
(Canada), VFR flights are rest ricted at certain
times of the day.
Given that most U.S. continental airspace is
controlled, there is therefore a strong incent ive
for pilots to get instrument ratings .
Instrument ratings and safety
Finally, there is the question of w hether having
an instrument rating improves flying safet y . In
its 1985 review of FAR 61-65, t he FAA publis hed figures from a 198 1 general aviat ion
safety review, w hich showed t his to be so:
Pilot qualification I flight
condition
non-IFR in IMC
IFR in IMC
Accident rate
1 per 1459 hr
1 per12 186hr
non-IFR in VMC
1 per 61900 hr
IFR in VMC
1 per 94819 hr
Economics
Economics is another factor that might be
expected to influence whether pilots gain
instrument ratings. But t he evidence is
contradictory.
Average per capita income in t he United States
is about seventy per cent higher than in Australia. Surely, therefore, not only could a larger
percentage of American pilots afford to get
their instrument rat ings, but more American
citizens could afford to get t heir pilot licences
in the first place.
In fact, the United States has fifteen times as
many people, and fifteen times as many private
and commercial pilot s as Australia. To put it
another way, despite our lower per capita
incomes, Australians are twice as likely to take
up the challenge of flying.
In the USA, however, it is commonplace for
business people to fly their own aircraft to
attend meetings in various parts of t h e country .
For them, having an instrument r ating is a distinct advantage. They are less inconvenienced
by weather conditions, and thus able to make
better use of their time in meeting fixed
commitments.
It should be noted , however , that in those days,
U.S. pilots were required to have at least 200
hours flying t ime before t hey could obtain their
instrument ratings. This requirement in itself
may have significantly reduced accident rates
for inst rument rated pilots.
No comparable survey has been conducted in
Australia, partly because t he relevant data on
flying hours is not available, but also because
accidents are defined differently in the two
countries. A good example is undercarriage failure; it may be defined a s an accident in Australia and an incident in the U.S.
Nevertheless, the CAA's Safety Promotion Unit
is well aware of the dangers of VFR pilots
pressing on into bad weat her. The Unit h as produced a film on t he subject called Going Too
Far, which was released in April 1990.
You can obtain a copy of the full research
report from the CAA Librar y or from the
author in Standards Development, CAA, GPO
Box 367, Canberra ACT 2601.
�AviationSafetyDiges~
149
Accident
response
Cessna 152 -v- Cessna 152, 29 May 1990
Circumstances
The pilot of VH-BFT, with limited experience in
General Aviation Airport Procedures (GAAP),
had completed a successful period of dual
instruction immediately prior to the accident
flight and was on a solo circuit when the accident occurred.
The pilot of VH-TNO was completing the first
circuit following a solo period in the training area.
The pilot of BFT, turning downwind from its
first take-off, gave a downwind call in the early
downwind position and was told by the Aerodrome Controller to 'follow the Cessna entering
mid-downwind in the 10 o'clock position'. This
was TNO, rejoining the circuit via the
crosswind leg, in front of BFT. BFT's pilot
acknowledged the instruction. The pilot of TNO
then gave a mid to late downwind call and was
told to follow the twin (DEP, a Piper Navajo)
on late downwind. The sequence DEP, on late
downwind, TNO, mid to late downwind, and
BFT, early to mid-downwind was then
established.
The pilot of BFT did not sight TNO at any stage
downwind, but instead identified the twin on
late downwind as the aircraft to follow. The
pilot of TNO sighted and followed the twin, as
instructed. TNO's pilot also sighted BFT behind
and to the right and assessed that BFT was
clear of TNO. The two aircraft proceeded to
carry out normal circuits.
During their independent turns on to final
approach to runway 06, BFT, which turned
base leg inside TNO, descended onto TNO from
above, behind and slightly to TNO's left. BFT's
right wing tip lead~ng edge contacted the top of
TNO's vertical stabilizer, bending the top one
third oflhe rudder, causing it to jam, and denting and dislodging the fairing at the top of the
tail fin.
The relative positions of the two aircraft during
the base leg and turn onto final approach prevented either pilot from seeing the other aircraft until after the collision. Following the
collision the pilot of TNO realised that something had happened, t hat the aircraft rudder
was jammed and that an immediate landing was
necessary. The pilot of TNO continued straight
ahead and landed on runway 06. The aircraft
n m off the runway onto the grass.
The pilot of BFT sighted TNO shortly after the
collision, diverted to the left and below TNO
and initiated a go-around. BFT eventually
landed safely.
Three controllers were on duty in the Jandakot
control tower at the time of the accident. One
controller occupied the Aerodrome Controller's
(ADC) position and a second controller the combined position of Surface Movement Controller
(SMC) and Co-ordinator (Co-ord). A third controller, occupying the Senior Tower Controller's
position (Snr Twr), had completed a handover/
takeover after coming on duty and was occupied at the rear of the tower.
Circuit traffic at the time of the accident was
moderate, although traffic during the period
immediately before the collision was heavy. In
the hour before the collision, 98 movements
were recorded with a further 66 during the
hour of the accident.
·
In the 12 minutes prior to the accident a disproportionate number of movements ( 44) were
recorded. There were seven other aircraft in the
circuit when TNO joined downwind, with six
remaining at the time of the collision. Radio
traffic was also very heavy during the period
immediately prior to the collision. The ADC
made and received 125 two-way radio transmissions during the 12 minutes preceding the
accident.
..
..
Having allocated a downwind sequence to the
two aircraft, and believing that BFT pilot's
acknowledgement of sequencing instructions
meant that TNO had been sighted, the ADC's
attention was concentrated on the other circuit
traffic.
During the 2 minutes 40 seconds between the
ADC's last-downwind call to TNO and the
collision there were 14 two-way transmissions.
The workload and practices were such that the
ADC did not observe e ither TNO or BFT again
until immediately prior to the collision. The
ADC had checked the runway was clear of
traffic, was moving TNO's flight strip and was
giving its pilot a clearance to land when the
impending collision was first noticed. As both
aircraft were head-on to the tower and t he aircraft were approximately the same distance
from the threshold it was not possible for the
ADC to determine which ·c all-sign belonged to
which aircraft. The ADC was unable to give
any collision avoidance instructions, as this
could have made the situation worse.
0
Responsibility for separation in the circuit area
at Jandakot rests with the pilots-in-command of
circuit aircraft. Assistance is provided by the
air traffic controllers by issuing instructions for
rejoining, downwind sequencing and landing
clearances. Safe separation in the circuit
depends on a good look-out and on the pilot
understanding the controller's instructions, following those instructions or advising the controller if the instructions have not been
understood or cannot be complied with.
In this accident, both the pilot of BFT and the
ADC thought that the downwind sequence
instruction had been understood and was being
followed. The pilot's inexperience led to a
traffic misidentification, whilst a combination
of workload and aircraft positions probably led
to a less than adequate look-out and consequent
failure to sight the conflicting aircraft.
Despite the presence in the tower of three controllers, circumstances, workload and the belief
that the pilot of BFT had sighted the conflicting
traffic prevented the developing collision from
being observed by the Tower Controllers until it
was too late.
Significant factors:
The following factors are considered relevant to
the development of the accident:
1. Pilot inexperience
The pilot of BFT was inexperienced in aviation
and particularly in GAAP. Although instructed
to follow the Cessna entering mid-downwind in
front at the 10 o'clock position, the pilot identified a different aircraft, a twin of different
make, late downwind in the 12 o'clock position.
A more experienced pilot would be expected to
look for the aircraft at 10 o'clock, to know the
difference between that aircraft and another on
late downwind and, if it was not identified,
indicate that fact to the Tower by radio. The
pilot had completed a dual trip immediately
prior to the accident flight and although difficulties were initially encountered with
J andakot circuit procedures the instructor's
final assessment was that the pilot's procedures
were satisfactory.
2. Distraction by other procedures and/ or cockpit visibility problems
As stated above, an experienced pilot would be
expected to sight another aircraft in front and
to the left at the same height on downwind.
Although the reason why the pilot of BFT did
not sight TNO during t he downwind leg could
not be determined, there were three main
possibilities:
(a) The pilot was concentrating on the
downwind spacing from the runway, and
manipulation of t he aircraft controls and/ or
downwind checks. This caused a distraction
which prevented a good look-out
(b) The position of TNO in relation to BFT was
such that the left-hand windscreen pillar
prevented t h e pilot of BFT from sighting TNO
(c) A combination of both the above.
3. Task Saturation
The radio transmission traffic during t he period
preceding the collision was very heavy. An
experienced pilot would be expected to listen to
the radio transmissions to help determine the
position of the traffic in the circuit. The pilot of
BFT had the opportunity to recognise a mistake
when the pilot of TNO was given downwind
sequencing. Inexperienced pilots, attempting to
cope with the other tasks associated with circuit flying may mentally tune out the radio
traffic that does not refer to their aircraft.
4. Failure of the Safety Net
The safety net, an overall safety concept provided by the Tower Controllers, is dependent on
the controllers having the time to carry out
their sequencing, landing clearance and other
tasks as well as being able to inspect the circuit
for unsafe situations in the making. The ADC,
having given the pilot of BFT sequence instructions and believing that they were understood
and followed, was then engaged on other tasks
and did not check the late downwind to final
legs of the circuit again until immediately prior
to the collision. The Surface Movement Control
Co-ordinator and Se~ior Tower Controllers were
engaged in their own tasks and did not observe
the developing confliction. Consequently the
safety net did not work.
5 . Aircraft Identification Problems
(a) The position of t he aircraft in relation to
the ADC prevented the ADC from being able
to differentiate between the conflicting aircraft, and so issue collision avoidance
instructions.
(b) The use of t he words 'Cessna' and 'twin'
may not have provided sufficient identification information. A Cessna can also be a
twin.
BASI Recommendations
1. All pilots and operators at GAAP aerodromes
should be reminded, through the publication of
this incident in either t he BASI Journal or the
Civil Aviation Authority (CAA) Safety Digest,
of their obligations to ensure that t hey and/ or
their pilots and students understand and comply with circuit radio and operational procedures. In particular, student pilots should not
be permitted to operate solo in a GAAP circuit
unless they are fully conversant with all the
required procedures.
2 . The Civil Aviation Authority should carry
out a review of the operational and administrative procedures used in the Control Towers
at GAAP airports with a view to improving the
safety net provided by the Tower Controllers.
�Aviation Safety Digest
149
In particular, the CAA should consider the allocation of a specific task, 'traffic spotting', to
one of the Tower Controllers. At airports where
there are high traffic densities and/or there is a
significant pilot training component, this task
may need to be allocated to an additional tower
position.
CAA ATS comments
Since this incident, great changes have been
wrought at J andakot. The commissioning of a
second runway has split the aerodrome into
what are virtually two independent operations,
each under the control of a separate Aerodrome
Controller with a dedicated frequency. This
brings J andakot into line with all other GAAP
aerodromes (except Camden - traffic there
does not yet warrant such upgrading).
This change in procedure has halved the area
that each Aerodrome Controller is required to
monitor, which means a very much enhanced
traffic-spotting ability. The 'new' Jandakot is
working well, and we consider the current
arrangements more effective than employment
of a separate ' traffic-spotter'; resource utilisation is more efficient and job satisfaction
much greater. On the occasions that operations
are confined to one runway, manning levels do
allow the use of a dedicated traffic-spotter.
CAA Operations Branch comments
While a reminder that pilots are primarily
responsible for their own separation while operating in GAAP control zones would not go
amiss, some other actions may also bear
consideration.
The possibility of air traffic controllers advising pilots of position in the landing sequence as
well as the type of aircraft preceding them. In
this instance, had the pilot been told that he
was number three, he might have been alerted
to both the aircraft ahead, a nd thus less willing
to accept that the aircraft he actually sighted
was the one to follow.
The present system also relies upon pilots being
aware of the names of different types of aircraft, and assumes that they can recognise
these aircraft in flight - a surmise not necessarily correct, particularly in the case of student
pilots (in this case, though, one would have
thought that t he pilot would have recognised
the same type of aircraft as he was flying
himself).
Perhaps a standardised system of naming different types for recognition purposes would be
of value, for ·e xample, 'Cessna' for all high wing
Cessna aircraft, and 'Light twin' for all such
types might suffice. Training organisations
would then be required to ensure that student
pilots were at least familiar with designated
generic types, prior to flying solo. An article in
the Digest, on the problems related to visibility
ASD 147 CAPTION
from high wing types, stressing the need for
adequate training in lookout procedures, may
also be of value.
C')
0
[ASD finds it hard to believe that instructors do
not emphasise such problems to each student.
Or are we being naive? Alternatively, I'm sure
I'm not alone in discerning an association
(possible poor instruction) with the inadequacies described in the article 'A little learning... ' in ASD 147 - ed]
z
~
m
CJ)
~
Mooney M20F
from a BAS! report
The aircraft was being used for pilot-underinstruction training towards CSP and retractable landing gear endorsement. This was only
the second flight on type for the PIC and first
for the pilot under instruction.
Both pilots stated that the pre-landing checks
had been completed and that the landing gear
'down and locked' light was illuminated and
this was rechecked on final approach to the
runway. The pilots reported that touchdown
seemed normal but the aircraft soon adopted a
left wing low attitude. The propeller then contacted the runway surface and the aircraft collapsed onto its underside before skidding to a halt.
A thorough examination of the landing gear
system revealed no fault. The type and location
of abrasion damage to the nosewheel doors and
the lack of damage to t he main gear fairings
and brake assemblies indicated that the doors
were closed when the aircraft contacted the
runway. In other words, the landing gear was
in the retracted position.
It was noted that the red and green post lights
on the instrument panel indicating high and low
vacuum pressure were of the same type as the
landing gear position lights. The green vacuum
light was seven centimetres from the green
'landing-gear down' light, in approximately its
two o'clock position. It was considered possible
for the crew to have mistaken one light for the
other.
Significant factors
• neither pilot was familiar with the aircraft type
• the landing gear was not extended
• the pilots possibly mistook the green vacuum
light for the green landing gear light on the
intrument panel
• the aircraft landed with the gear retracted.
ASD makes a further observation: similar
lights, different (and vital) functions - should
they be quite so close together? Traps for young
players #1001?
I know he's the captain, but do we really have to kiss his feet each time?
The contest was judged by two senior members of the CAA's Yic{fas Field Office, Warren Dickson (AGM
Corporate Management) and Mike Lewino (AGM Safety Regulation). They reported that it was great to do
business with us all, and selected the following:
WINNER:
I know he's the captain , but do we really have to kiss his feet each time ?
0
P Novakovic, PO Box I 004 COOLANGATTA, 4225
HONOURABLE MENTION:
I'm sure the flight attendant said "board the aircraft through the forward door".
Mark Nelson, 43 Hang Lok Road, HONG KONG
Well crew - I suppose you are wondering why I've called you all together here ?
W Heitbrink, 1/ 114 Castle Hill Road, WEST PENNANT HILLS , 2125
Now you all may be wondering why we are gathered here today.
Bryan O'Toole, Lot 2, Beaudesert/Beanleigh
Road, WOLFFDENE, 4027
Quick! Hide! the CAA inspectors coming!
R Schultz, 15 First Ave, NTH DANDENONG,
3175
Beam us up Scotty!
John Markoulis, 36 Milner Road,
GUILDFORD, 2161
Wow! What a big rubber band!
Andrew Baxter, 10 Palisade Lane,
WILLETON, 6155
The judges
A handsome, suitably inscribed plaque is being produced, courtesy of the Vic{fas Field Office, and will be
despatched to Peter Novakovic ASAP. To the runners-up we offer our congratulations for their imagination,
and to all the two hundred readers who entered the contest go our thanks for lightening the drabness of (some
of) our days!
Aviation Safety Digest 149 / i
�- If
Jl#ll
ASD 147 was obviously contentious, for we have received
much more mail than usual. The following letters are typical:
Dear Sir
Mr Tizzard (ASD 147) demonstrates a total lack
of comprehension of what was in my letter. As
a consequence his response is irrelevant and
meaningless.
I wrote to draw attention to a very real defect
in current legislation. What happens to the VFR
pilot who is caught inadvertently in non VFR
conditions? The answer is that the present
legislation kills a proportion of those unfortunate pilots, legally and efficiently.
There is no fundamental flaw in my understanding of what to do in non VFR conditions.
Mr Tizzard's advice, to hold, divert or make a
precautionary landing is excellent advice. The
fatal problem with it is that circumstances can
arise where none of these options can be
exercised.
He describes instrument training in the RPPL
and UPPL syllabi as being there to teach pilots
that flight in IMC conditions is highly undesirable. In plain English, what he is saying is that
instrument flight training is there only to
frighten the student. This theme is repeated a
few lines later in the '175 seconds to loss of
control'. The use of fear as a training aid disappeared generations ago.
While I would prefer to ignore it, comment must
be made on Mr Tizzard's discourtesy. Public
debate on an issue cannot take place when it
descends to the level adopted by Mr Tizzard.
It is grossly insulting. to be told that my comments are 'not merely disingenuous'. This is followed by the observation that he cannot
determine whether I have any aviation knowledge or whether I am acting for a constituent.
Other considerations aside, these observations
are completely irrelevant. The matter for
debate is the adequacy of the regulations.
For the record I have held a licence for 26
years, owned my own aircraft for more than
20. Furthermore, as a Senator I would never
feel constrained to act in the interests of any of
my constituents. Indeed I would be failing in
my duty if I did not.
Since the ASD has been published, I have been
contacted by a large number of people, some as
far away as Perth and the majority total
strangers. Without exception they have all been
outraged at the attitude and conduct of Mr
Tizzard. For my own part, in what has now
been a long and close association with the CAA
and its predecessors, I have never experienced
anything but unfailing courtesy in my many
dealings with its officers, Mr Tizzard excepted.
ii/ Aviation Safety Digest 149
iliCI
My letter was written out of concern for the
pilot who is genuinely caught out in non VFR
conditions. But the issue is much wider than
that. Pilots should be able to fly in IMC conditions without a Command Rating with the
proviso that there are some limitations on what
they can do. Other countries with far worse
weather conditions than Australia successfully
operate an En Route IMC rating. The very fact
that the CAA grants a night VMC rating means
the CAA accepts and condones pilots flying at
night in IMC.
Senator David MacGibbon
CAA comment by Paul Middleton, Assistant
General Manager, Standards Projects Branch,
Sa/ety Regulation and Standards Di?Jision:
The introduction of the Command Instrument
Rating in 1987 was a reduction of the requirements of the previous decade. It was designed
as a 'minimum standard' instrument rating at
considerably reduced monetary cost to the
holder. It is a compromise between the highly
questionable 'enroute rating' and the previous
standards.
To date, the Authority is very pleased with the
Command Rating. While some sectors of the
industry claim it is far too lenient, the accident
rate for IFR is still comparable to that of
pre-1987.
No doubt readers are aware that the overseas
'enroute rating' is not an open slather arrangement, but contains requirements for 'let-down'
training through to severe restrictions on use
depending upon the country.
ASD merely adds that the Senator's letter
suggests any VFR pilot can 'inadvertently' get
into non-VMC conditions. Is he therefore proposing an IFR rating as part of the PPL?
Dear Sir
I was most disturbed to read Steve Tizzard's
attack on Senator David MacGibbon and his
support for the en-route instrument rating in
Aviation Safety Digest 147. For the information
of Mr Tizzard, the Senator is an experienced
pilot and a Freeman of the Guild of Air Pilots
and Air Navigators. He is well informed on aviation matters and was a member of the recent
Senate Select Committee into the airline pilots'
dispute.
Senator MacGibbon is supporting the efforts of
the Guild over many years to reduce the loss of
life in weather-related accidents. Our research
has shown that even the limited instrument
expertise of a Night VFR pilot and the consequent ability to fly in cloud to an area of
known VMC is sufficient to produce an accident
rate from such causes five times lower than
that of the general pilot population.
The key to instrument proficiency is recency
and the proposed en-route instrument rating
would enable pilots to maintain that recency
within their limited capability. Such ratings
have been successful in the UK and in
Singapore.
A few diehards within the CAA and its predecessors have consistently blocked the proposal
despite its success overseas and its wide support within Australia from such organisations
as AOPA.
Mr Tizzard should also be aware of Recommendation 59 of the Air Safety Regulation Review .
'The Civil Aviation Authority and the industry
should investigate the feasibility of introducing
an en-route instrument rating along the lines
proposed by the Aircraft Owners' and Pilots'
Association and the Guild of Air Pilots and Air
Navigators'.
It is time to do something other than simply
preaching at VFR pilots to avoid a non VMC
situation. Many pilots have died attempting to
remain in VMC. Had they had the benefit of
some recent instrument experience they would
most likely have survived. It is time to
implement Recommendation 59 of the Air
Safety Regulation Review and get the en-route
instrument rating under way.
P K Davenport, Chairman, Australian Region
Guild of Air Pilots and Air Navigators (Phil
pavenport is a pilot with QANTAS)
GAPAN sent us statistics (supplied by DoT for
the years 1972-76 inclusive) in support of his
proposition of the five-times -lower accident
rate. Here are extracts from the GAPAN letter:
Weather Related Accidents
Loss of control
Other Weather
Instrument
in flight or
related accidents
Rating
controlled flight
accidents
into terrain
Class 3 or higher
2 (2)
7 (1)
Class 4 or 5
1 ( 1)
1
No Rating
17 (14)
74 (1)
Total
20 ( 17)
82 (2)
(parentheses indicate fatal accidents)
As of 30 June, 1976, there were 1332 holders of
Night VMC ratings out of a total pilot population of 18449 (7.2%)
On a pilot population basis, the 7.2% Night
VMC pilots had 5% of the loss of control and
terrain collision accidents, and only 1.2% of
other weather-related accidents.
As Night VMC ratings were then a requirement
for the issue of a CPL, the annual hours flown
by a Night VMC pilot were from anecdotal evidence at least three to four times that of an
unrated private pilot.
When the additional annual hours flown by a
typical Night VFR pilot are considered (say
three times as many), Night VMC pilots flying
21.6% of the hours had 5% of the loss of control and terrain collision accidents, giving a
probability of between 4 and 5 times lower than
non-rated pilots. The overall weather-related
rate for Night VMC rated pilots flying 21.6% of
the hours had 1.2% of the accidents for a probability 18 times lower than the non-rated pilot
population.
The Guild proposes a standard of en-route
instrument flight considerably in excess of that
currently required for Night VFR. Indeed, the
standard proposed is substantially that for a
Command Instrument Rating, without the letdown procedures which currently occupy a considerable portion of the course. As night flying
away from extensive ground lighting requires
substantial instrument rather than visual reference, we feel that such operations should
qualify as instrument time for En-Route Instrument recency purposes.
GAPAN also notes the figures are rather dated,
but submits that the high fatal accident rate of
the loss of control or flight into terrain accidents is a major source of concern.
ASD, in turn, suggests that these figures support the argument that to fly in cloud requires
at least a Command Instrument Rating, for
there is nothing in the statistics presented to
suggest that NVFR pilots enter IMC. If NVFR
pilots do in fact fly on the gauges, perhaps we
need a new definition of VMC.
A cogent argument might be that the '3 to 4
times' the annual hours flown by Night VMC
rated pilots would, apart from anything else,
have delivered the message that IMC is inappropriate for VFR operations. To such an
extent, we propose, that such pilots would
realise their limitations, either on the ground
at the briefing stage or well before being committed to flight in cloud during a trip. Notice
the figures don't mention the number of Night
VMC (NVFR) rated pilots who avoided accidents, by day or night, simply because they possessed sufficient self-discipline to cancel their
Aviation Safety Digest 149
/iii
�- -,
plans or, if the weather airborne deteriorated,
had no qualms about making an early decision
to hold, return, divert or even carry out a precautionary search and landing, all in VMC.
In summary, this magazine agrees with Mr
Middleton - if you want to fly in cloud in Australia, you should be professional and get yourself a Command Rating (the 'minimum
standard', and more or less what GAPAN proposes). Don'tforget that, although pressures
may exist for you to be trained on each of the
the various let-downs, you can gain your rating
on just one aid. The hours, the instruction and,
yes, the money you spend will all increase the
safety and convenience of yourself and your
passengers.
Of course, 'minimum standard' can be defined
and re-defined ad nauseam, but isn't that
where we came in... ?
Dear Sir,
The Senator's comments would truly represent
many VFR pilots' views regarding a possible
en-route instrument rating. Certainly, twelve
months ago I felt the same. I privately fly a
Cl82 Australia-wide, about 300 hours a year.
The Senator's comment relating to the fact that
'in the real world, VFR pilots, if they fly
enough, will be faced with non-VFR conditions
at some time' is certainly true, and I faced this
more and more as my flying hours clocked up. I
am an Electronic Engineer and have always felt
confident flying on instruments. I had been
hoping for quite some time that this new
en-route instrument rating would be introduced,
because it suited my situation perfectly.
Finally, however, I felt compelled to make the
effort and justify a .Class 1 Instrument Rating,
as it now has become easier without the Morse
code requirement.
This was when the 'real world' of IMC flying
caught up with me. I know now that there can
be no en-route or intermediate rating, because
of the many factors and situations that can and
do arise when you actually enter that cloud. A
pilot flying in IMC must be able to safely conduct procedures for an undetermined length of
time. Flying in IMC is not merely keeping the
aircraft upright, it is precise flying within tight
tolerances to enable the pilot to know the
plane's position accurately at all times.
iv/ Aviation Safety Digest 149
Dear Sir
The Senator is completely unfounded in his
comments about the exorbitant expense of over
30 hours, frequently in a twin. I conducted my
Class 1 training totally in a 210, making my
rating valid for single-engine aircraft only. Concerning the comment 'stress of constant
renewals', I believe the licence currency
requirements are very realistic. I know myself
that after three weeks without an ILS, when I
actually perform one it may be within tolerance, but not as good as I have done.
The Senator also made mention that a VFR pilot
holding an 'en-route' rating would not abuse the
privilege and not take off in solid IMC. Of
course, in time the situation would arise when
the pilot would feel confident enough to try it.
Consider the following case:
Say the pilot departs Parafield to the east on a
still morning and heads straight into stratus at
1500 ft, expecting to pop out at say 4000, a few
minutes later. The pilot may be stuck in it a lot
longer than planned! On the climb out, icing
may occur at a much lower altitude than ever
imagined, or forecast (it has happened to me
out of Parafield). This could be instant panic
for the VFR pilot, who continues heading over
the Mt Lofty Ranges, still in cloud, not climbing
as fast as planned but simply hoping to get on
top of it. Now, not being 100% sure of position,
the decision is made to return. To avoid hitting
anything it is necessary to remain in cloud for
some time coming back over the ranges. Say
some 25 minutes have now passed. If panic
hasn't resulted in a spin and crash, how can a
safe landing be made without following a prescribed Instrument Approach to either Adelaide
or Parafield? Surely now, a full emergency must
be declared and the aircraft be radar-vectored
to a [visual] approach to the runway.
I now know from personal experience that all
the Class 1 training undergone is necessary to
ensure the safe landing of a flight such as that
described above. I honestly believe the way the
Class 1 regulations and procedures are laid out
are precisely what is required for the pilot to
carry out safe IMC flight, and so I strongly support Steve Tizzard's view. If Senator David
MacGibbon is a private pilot, I strongly urge
him and any other private pilot to simply get a
Command Instrument Rating if they need to fly
in cloud; their views will change, just as did
mine. The rewards of operating IFR anywhere
and everywhere are wonderful, generating the
safest and most self-satisfying flying possible.
There cannot be an in-between: you either fly in
IMC by the Class 1 rules or you don't fly in IMC
at all.
K. Eldredge
When I retired, some years ago, from airline
flying, I continued to hold a private licence.
Two years later I renewed it with three hours
on a Tiger Moth, thereby completing the full
circle. It amazed me to find that while it was an
easy aircraft to hire, the club instructors
headed for the hills when I asked for someone
to take me for a quick refresher. I have had a
great affection for the Tiger ever since my
instructor demonstrated a landing backwards
and upside down, and was astonished at the
terror it seemed to inspire in what appeared to
be an otherwise normal group of pilots.
Two years later, when confronted with another
renewal, without having flown in the meantime,
I chose to let the licence lapse.
My reasons were as follows:
0
• There seemed to be little point in renewing
the licence just to have it. I did not have the
time to use it, and I had other things on which
I preferred to spend my time and money.
• I realised that I was rusty on control and circuit procedures and was probably becoming a
hazard to myself and others. This would not
have been difficult to overcome, but I also
realised that there must be others similarly
placed but without my years of background,
who could well be swanning around in the
same airspace.
The odds, in other words, were becoming
unfavourable, so I quit while I was in front.
Had I decided to continue, I would have wanted
a solid refresher. Perhaps I was over cautious,
but there it is. I have always been a devout
coward.
One of the things that prompted this letter is
the sad similarity between this ASD and almost
any other since it was first published. Only the
aeroplanes have changed.
It would seem to me that the PPL course is
inadequate in content and suffers from possible
discontinuity. I know there is a severe problem
with cost, and that a more comprehensive and
cohesive course would eliminate numbers of
aspiring pilots for financial reasons, if no other.
But in these increasingly crowded skies may
this have to be considered?
Are we looking at a civilian equivalent of CFS?
As I do not want bullets through my kneecaps, I
will leave it there. But is it a case of 'Your
money or your life?' Remember we have a sort
of relief valve in the Ultralights.
The letter from Senator MacGibbon is dangerous. Lots of people will believe an authoritative
statement from a Senator, but Senators have
been making authoritative statements for over
two thousand years without allowing themselves to be confused by facts. While I would
never say that much of his letter is codswallop,
I would hesitate to accept his offer of a lift.
If I tread on any toes because of my opinions I
am unrepentant, but if these opinions are out of
line because by knowledge and understanding
they are out of date, then I do apologise.
'Biggles'
'Biggles' (name and address supplied) is
ex-QANTAS, with some 16 OOO hours.
Dear Sir
I feel I must write to express my disappointment in this present summer edition of the
Safety Digest. The submission by Jeff Bolinger
titled '89rs' is an offence to the standard of the
publication and one would question the wisdom
of its inclusion in any edition, and, the maturity
of the author.
I was under the impression that this new look
Digest was to reflect an intelligent and helpful
presentation for the benefit of all airmen. What
then is the value of a contribution such as this
which is extremely negative and critical of a
significant number of pilots.
In this article pilots such as myself are
reportedly not 'real pilots' at all, we have
'wasted our hard earned dollars on a flying fantasy', we are 'accidents about to happen' etcetc.
1 felt personally hurt by the insolent a nd
degrading terms and remarks made by Mr
Bolinger. Indeed, I should like to see some
official reply to the inferences and accusations
made by this egotistical person. After each
check flight I am assured by my instructor that
I am a safe pilot. Is he right, or is Mr Bolinger
right? Am I a pest to other pilots, as I am said
to be in this article?
I am aware of my limitations and fly accordingly, and I resent reading in the Digest that I
am a liability to my fellow airmen and that
'with any luck I might get tired of it and give it
away'.
This kind of material will do nothing to
advance the cause of safety, nor will it perpetuate the sense of brotherhood among airmen.
K MCooke
['a significant number... '? -
ed]
Aviation Safety Digest 149 / v
�The next extract was a further thought by a
correspondent in his reply to our spin
questionnaire:
...I commend the comments in your article
'89rs', as I went down that road. Because of a
lack of funds, I amassed only 60 hr total in the
six years following my RPPL. At this point I let
my licence lapse, as it was obvious that I
wasn't maintaining a suitable standard. When I
took up flying again in 1986, thirteen years
after first gaining my licence, I was surprised
how far behind the ball I was, although age
may have been a factor. If you can't afford to
fly at least 25 hours a year, you should not
obtain a licence. Note that I consider 25 hours
the absolute minimum.
S D Mellow
... and again, from another concerned pilot:
Dear Sir,
I have just completed reading the article
entitled '89rs', which highlights a personal concern that I have had for some time, ie, the currency of licence status under the 2-year Private
Pilot's Licence Aero Medical and Biennial Flight
Review as now applies.
Some twenty or more years ago, it took me a lot
of money and effort to gain the licence from
which I have had some enjoyment and sense of
achievement in safari-type expeditions, glider
towing etc. For this reason, I am most reluctant
to relinquish the licence. However, financial
commitments with children at school, and the
usual attendant costs of just living allow very
little time or money for flying. In fact, I'm
almost down to the bare amount every two
years when the BFR is due.
The item mentioned above highlights the matter, and I have been dreading the introduction
of MONTHLY currency checks as a strict
requirement for retaining the PPL.
This stems from having a totally vitriolic
stream of abuse fired very effectively at me of
recent date by a group of three what I understand to be either Commercial Pilots and/or
instructors. Their main thrust ran as follows:
It's people like you who cause most of the bad
accidents/incidents, give all light aircraft operators a bad name, cause hold-ups and delays at
airports because you don't know the latest correct procedures, don't keep an adequate lookout in busy areas because you 're to involved in
trying to remember how to control the aircraft
(meaning placement of switches and controls},
cost all tax-payers and GA pilots a lot more
than it should in mailing necessary infor·
mation; and all this JUST SO PEOPLE LIKE
YOU CAN HA VE THE STATUS SYMBOL OF A
PILOT'S LICENCE!
vi /Aviation Safety Digest 149
To say that a manoeuvre is dangerous, and yet
not understand what is involved is sheer ignorance on the instructor's part, and should not be
tolerated.
Many of our students have been down this
road, that is why they come to us in order to
obtain confidence in their flying, especially in
the manoeuvres mentioned above, which have
been so badly tarnished by the ignorant.
Once they complete our course many of them
often say "WHY WASN'T I TAUGHT THAT IN
THE FIRST PLACE!" They are referring to our
stall recovery techniques and other BASIC
manoeuvres.
WHY INDEED! Because the Civil Aviation Authority is not using its authority to uphold an
acceptable flight training standard. We all
should be aiming for a high standard, not just
the minimum required, as we have now, which
inevitably brings everything down to the lowest
common denominator.
I believe that the CAA should review its minimum acceptable candidates from various
schools.
I also believe the standard for issue of a Grade
3 instructor rating should be increased greatly
to include syllabus items like those mentioned,
and candidates tested on them. Instructors
should be stopped from teaching incorrectly or even at all, as in the case with some of my
students.
These matters need to be addressed now, not
until someone else is killed by a manoeuvre that
he/she is incapable of recovering from, merely
because he/she was never shown how to
recover.
It was concluded that the CAA should:
• call in all log books and scrutinise the frequency of the licence-holder's flying; ·
• ask those who fly less than once a year what
their intel).tions are; and
• cancel the licences of those who now only fly
once a year or less UNLESS they go through a
complete and comprehensive ground and air
course and undertake to fly regularly every
30 or perhaps 60 days thereafter.
Tough talking indeed! I would have to surrender
my licence and say 'goodbye' to ever flying a
light aircraft again - a very sad day indeed.
Again, TOUGH! It would be a damn sight sadder
if I caused my wife to be a widow, my children
to be orphans, or if I was the cause of another
person's death or injury simply because I was
not fully alert and aware of what I was doing
in the air, even with the best of intentions, by
not being properly and fully current.
I have written this to obtain your opinion on
the matter, and also to see if the opinions so
strongly expressed to me are shared by others
in the flying business. Surely there must be a
way for those of us who love to fly to be able
to retain our licences and not be the perceived
'menaces' as would appear. Otherwise, flying
will become a rich person's hobby and those
with real talent and a sense of responsibility
will be excluded.
With some trepidation,
Yours in aviation,
'VJE' (name and address supplied)
'VJE' may be contentious and even a little inaccurate, but he's certainly no wimp. Any ideas?
Dear Sir
I am writing to you in deep concern of the standards of flight training, or should I say the lack of!
I am an aerobatic flight instructor based at
Bankstown airport, and most licensed pilots we
get as aerobatic students share Mr Perkins's
lack of confidence in recovering from level
stalls, wing drops at stall, and incipient spins.
Pilots at the UPPL level should be confident at
recovering from these situations, if they are not
it is because of poor instruction, and through
no fault of their own.
The poor instruction is caused by a lack of
understanding by the instructor of those
manoeuvres that in my mind are essential for a
pilot to know. The instructor himself is uneasy
in demonstrating the manoeuvre and avoids
demonstration by saying it is dangerous to perform. This information I have gained from
many students.
Let us all lift our game, that includes you
too, Civil Aviation Authority!
D Nidzovic
Concerning 'Heavy Landings', in ASD 147, we
have received some interesting input. I hope
you won't accuse us of stressing
( overstressing?) the obvious if we print this
extract from a letter by the Director, Flight
Standards, GAG Vanuatu. He speaks from personal experience:
)
' ... the fact is, that when an aircraft suffers a
heavy landing (even a crash!), the impact rarely
feels as bad as everybody on board expects.
Almost any external observer will wince, but
inside the aircraft it doesn't feel that bad. The
reason is quite simple: any airframe (or even
your car), in breaking up, bending, crumpling or
whatever, is in fact absorbing impact forces,
which are therefore not being strongly transmitted to the occupants. A rigid, exceptionally
strong airframe may survive impact more successfully, but at the expense of its occupants .
I remember an MU2 flared for landing at 50ft.
It fell to the earth with a thud that severely
damaged the airframe (surprise!), but both
pilots were astonished at the damage done,
because 'the landing seemed quite normal'.
The lesson, of course, is that your approach
looks abnormal, late or high, the severity, or
otherwise, of the touchdown should not be a
basis for deciding to carry out a detailed postflight inspection. If you flare either very early
or very late, one of the subsequent bad signs is
that you do not bounce: an airframe efficiently
absorbing shock by crumpling just doesn't!
When I discuss this with pilots, they usually
respond 'Of course we understand that', but I
believe that too often this conscious process of
thought doesn't get applied when driving an
airframe, otherwise more heavy landings would
get reported than now is the case.
ASD, in agreeing with this, re-implores pilots to
write-up or at least report anything untoward
that might have happened during their stewardship of the aircraft.
Dear Sir,
I read with interest the article on heavy landings in ASD 147.
I flew the aircraft in question only two or three
weeks prior to the incident described. After a
firm night touch and go, which was certainly
not hard, the gear ·in transit light remained
illuminated after gear up selection. After cycling the gear without any change in the situation, I returned to Bankstown and reported the
problem.
In this case, the LAME simply re-adjusted the
microswitches and the problem went away for a couple of weeks.
Such problems are not uncommon in Piper aircraft with this type of undercarriage system.
The undercarriage has no uplock, and depends
upon hydraulic pressure to hold the gear up. If
for any reason one of the gear up
microswitches trips, even with inflight turbulence, the electric driven hydraulic pump will
start and the gear in transit light illuminate.
Cycling the gear will usually clear the pro~lem.
In this particular aircraft, I suspect that there
had been some progressive movement at the
undercarriage attachment point which prevented the microswitch from closing properly.
Aviation Safety Digest 149 /vii
�AviationSafety Digest
149
Do you lose airspeed when you
turn downwind?
1111&
The microswitch adjustment should not drift so
quickly without some underlying cause.
While the Airworthiness Branch of the CAA has
no history of progressive undercarriage failure
on Piper Arrows, there is always a first time.
Qantas had an undercarriage collapse on a
Boeing 707 during push back a few years ago.
The aircraft in question had been used for circuit training at Avalon for some time, and happened to have more landings than any other 707.
We must keep in mind the fact that most singleengine aircraft in Australia are quite old. The
probability of age-related mechanical failures
should encourage pilots to be particularly diligent in pre-flight checks. LAMEs should also
consider whether the need to adjust some part
like a microswitch might indicate something
more serious happening nearby.
John R Colwell
ASD remarks that it's sure that LAMEs do just
that as a matter of course. As for preflight
checks, well, the beast you 're looking at is
about to take you into the wide blue yonder;
you want it to bring you safely back, too.
Dear Sir,
I would like to relate the following experience
in the cause of flight safety, particularly in
areas of high density such as the circuit area:
The weather was VMC and safe, so I decided to
take a student for a lesson on circuits and landings at our uncontrolled aerodrome. We gave
taxiing, backtracking and departure calls and,
since there was no other traffic, just a first
base call. From then on we maintained a
listening watch and, of course, look-out. My
intention, as normal, was to give calls when
hearing traffic or sighting other aircraft, either
airborne or on the ground.
We were downwind at 500 ft AGL when we
sighted an aircraft in our 2 o'clock (we were on
right-hand circuits ·RWY 18), same level, nose to
nose at about 200 metres we immediately
turned left, and I transmitted the direction of
the runway in use. As the response was not of
good quality, I subsequently requested the
other pilot's intentions. 'Transitting to the
south' was the reply!
Now, I thought, how really nice of him - going
through a circuit area at 500 AGL without saying a word. Surely he valued his life as much as
I did mine?
On the ground, I checked the register, found the
aircraft type, and estimated a closing speed of
around 200 kt. Then I flipped through 'Aircraft
viii/ Aviation Safety Digest 149
and Aerospace 1991 Annual Reference Edition'
to obtain details of the aircraft and, lo and
behold, came across an article 'Basics to avoid a
mid-air collision'. The para read: 'When you fly
close to an aerodrome or ALA, do you overfly
or throughfly the circuit area?'
Now this was eminently interesting and relevant, so when I rang Flight Service to check
the info was up to date, I mentioned the incident and the article. The Briefing Officer said
'Oh yes? I wrote that piece!' - too much of a
coincidence? I don't think so.
I hope people will observe some simple rules
and commonsense when flying past an uncontrolled aerodrome, ie either fly at or above
1500 ft AGL, or keep clear by at least 3 nm.
As for me, well, even when there is apparently
no other traffic, I will give a call on· every circuit, even though it may congest the frequency.
After the incident described, I'm afraid I can't
rely on others to adhere to the correct
procedures.
Neil Johnston
CPL, CFI
Two notes:
1. Let's keep coincidences out of the circuit!
2. Be advised that, though 1 500 ft will keep
you away from virtually all propeller traffic,
it's not sacrosanct - anyone can.fly circuits
at that altitude, and most jets do.
Neville Probert, Aircraft Performance Engineer
(
0
A
OPA' , the journal of the Aircraft Owners
and Pilots' Association of Australia,
recently published a series of letters to the
Editor on the subject of turning downwind in
strong wind conditions. Some writers warned
that an aircraft loses airspeed when turning
downwind, but gains airspeed when turning
into wind. Others disagreed. The debate proved
to be a lively one and attracted many letters.
Supporters of the proposition that an aircraft
loses airspeed when turning downwind offered
detailed explanations resembling the following:
Consider an aircraft flying at 80 knots true
airspeed into a 30 knot headwind. Its ground
speed is 50 knots. It turns through 180° and its
ground speed increases from 50 knots to 110
knots. The 60 knot increase in ground speed is
the result of an acceleration which can only be
caused by loss of height or additional thrust
from the engine. It takes time for the aircraft to
accelerate to 110 knots ground speed and until
that happens the airspeed must be below 80 knots.
Some writers warned that many fatal accidents
have been caused by pilots carelessly turning
downwind and recommended that in an emergency close to the ground a quick turn into wind
would be beneficial because of the additional
airspeed which results. Others disagreed. The
AOPA experience has shown that the subject is
of great interest to most pilots, but clearly
there are at least two conflicting viewpoints. It
should be of benefit to all pilots, particularly
instructors and those new to aviation, to understand why it is NOT inherently hazardous to
turn downwind and why an aircraft DOESN'T
gain airspeed when turning into wind.
This theory of a cyclic variation in airspeed
during turning flight in wind conditions is
almost as old as manned flight itself. It became
a popular but incorrect explanation for the
unintentional spin which was poorly understood
and caused many fatal accidents in the years
before improvements such as the Handley-Page
slat. Most attempts at proof are theoretical.
Observations offered as practical evidence
relate to bodies other t han aircraft in free
flight, or to occasional experiences which are
best explained in terms of induced drag or local
atmospheric effects. Despite development of the
Flight Data Recorder and Iner tial Navigation
System no sound evidence has ever been found
of any cyclic variation in airspeed due to wind.
Many pilots appear to have been deceived by
the following kind of experiment involving a
360° turn:
Heading into wind they note the indicated airspeed and then roll into a steep turn. Induced
drag increases and as they turn downwind they
observe a decrease in airspeed or loss of height.
They continue the steep turn unt il heading into
wind again and then roll wings level. Induced
drag reduces and they observe an increase in
airspeed or gain of height. They will observe
the same things regardless of the wind speed or
their initial and final heading.
Flight testing of an aircraft's turning performance, if it is to be credible, must be done in a
steady turn in order to minimise the transient
effects caused by a varying lift coefficient.
Helicopter pilots sometimes observe changes in
a irspeed during apparently steady turns but
this is due to changes in forward thrust or sideslip.
Persistence of the belief in a loss of airspeed
when turning downwind appears to be due to a
misunderstanding of Newton's First Law of
Motion, sometimes called the Principle of Inertia. Those who predict a loss of airspeed when
turning downwind usually explain that it is
due, not to the action of some force, but to inertia. In fact, this idea contradicts the Principle
of Inertia which asserts that a body's speed and
direction will change only if some external
force acts on the body. The Principle of Inertia
applies to true airspeed with as much validity
as it does to ground speed 1 , although the presence of turbulence, wind shear or wind gradient
can cause fluctuations in airspeed unrelated to
the action of any force. The theory incorrectly
attempts to explain the increase in groundspeed
as being due to excess thrust or loss of height.
But it offers nothing to suggest what force
might be responsible for a decrease in airspeed.
�~
Aviation Safety Digest
Aviation Safety Digest
149
149
1PHYSICS Section 1-3 Reference Frames, by
David Halliday and Robert Resnick , published
by John Wiley &Sons Inc., New York 1966, states:
The velocity of a train has one value if
measured by an observer on the ground, a different value if measured from a speeding car,
and the value zero if measured by an observer
sitting in the train itself. None of these values
has any fundamental advantage over any
other.
and
Consider reference frames moving with uniform
velocity with respect to each other. Observers
in different frames may obtain difjerent
numerical values for measured physical quantities, but the relationships between the
measured quantities, that is, the laws of
_physics, will be the same for all observers.
0
'""
""'
•
c
B
A
FIGURE 1
Notice that the horizontal component of lift is
perpendicular to the heading, causing no change
in airspeed. More importantly, notice that the
horizontal component of lift is NOT perpendicular to the track. It is inst ructive to resolve this
force into_two components, A and B. Component
A acts at a tangent to the aircraft's curved path
across the ground. It is a tangential force causing an INCREASE in ground speed. Component
B is a centripetal force causing curvature of the
aircraft's path across the ground. Notice that
the ground speed is increasing even though
there is no change in airspeed. The radius of
turn observed from the ground is partly determined by the magnit ude of component B. The
instantaneous centre of the turn observed from
the ground lies in the direction indicated by
component B.
WIND
'
In order to uncover the correct explanation for
the motion of an aircraft turning in wind let's
first review something familiar to all pilots forces acting on an aircraft in flight. Figure 1
shows three aircraft flying straight and level.
Of the four forces acting on an aircraft only
thrust and drag appear on these diagrams .
These two forces on aircraft A are equal and it
has a constant speed. Aircraft B experiences
excess thrust and its speed is increasing. Aircraft C experiences excess drag and its speed is
decreasing.
Figure 2 shows an aircraft turning in level
flight at constant speed. Thrust and drag cancel
so they are not shown. The force pointing
towards the centre of the turn, the centripetal
force, is the horizontal component of the lift
acting on the aircraft. The velocity of the aircraft is also shown. (This is the true airspeed
and heading of the aircraft). Even though the
centripetal force is large it does not increase or
decrease the speed of the aircraft because it
acts perpendicular to the velocity. The radius
of turn of the aircraft through the air is partly
determined by the magnitude of the centripetal
force. The centre of the turn through the air
lies in the direction indicated by the centripetal
force.
Figure 3 shows two aircraft turning in level
flight. Aircraft A is experiencing excess thrust
and its airspeed is increasing. Aircraft B is
experiencing excess drag and its airspeed is
decreasing. Notice that the resultant force on
each aircraft is no longer perpendicular to the
aircraft's velocity.
When a force acts on a body in motion any
component of the force perpendicular to the
body's velocity causes the body to turn, following a curved path, but does not affect its speed.
Any component parallel to the velocity causes
the body's speed to increase or decrease, but
does not ca use it to turn.
11ue1111pee<1
I
HORIZOtfTAL
HORl20NTAL
COMPONENT
OF LIFT
COMPONENT
OFUFT
0
WEIGHT
•
FIGURE 2
•
FIGURE 4
Aircralt heading crosswind In steady lelt 1urn
Alrcratt 1urning in level lligh1 a1 cons1anl speed
It should now be clear that the cyclic variation
in ground speed when an aircraft is turning in
wind conditions is brought about by the tangential component of lift. The increase in
ground speed when turning downwind does not
occur due to excess thrust! The decrease in
ground speed when turning into wind does not
occur due to excess drag!
At the instant a turning aircraft is tracking parallel to the wind its tangential component of lift
is zero. As it continues to turn, the component
of lift t angential to its path across the ground
increases to a maximum v alue at the instant the
aircraft is tracking directly crosswind, and then
decreases again as the turn continues.
The lift on an aircraft acts perpendicular to the
aircraft's direction of motion through the air, so
never causes any change in airspeed. Any horizontal component of lift is always a purely centripetal force. Consequently there is no force to
cause a loss of airspeed when an aircraft turns
downwind unless t here is a gain of height, a
reduction in thrust or an increase in drag. Similarly there is no force to cause an increase in
airspeed when an aircraft turns into wind
unless there is a change of height, thrust or
drag. But relative to the aircraft's direction of
motion across t he ground t he horizontal
component of lift is partly cent ripetal and
partly tangential if there is any wind. The t angential component causes the change in ground
speed.
Let's now examine an aircraft as it t urns into
wind. Figure 5 shows the aircraft, halfway
through its turn, heading crosswind.
WIND
N
'
HORIZONTAL
··~"'"'
COMPONENT
O F UFT
~
~
HORIZONTAL
HORIZONTAL
COMPONENT
COMPONENT
OF UFT
•
OFUFT
FIGURE 3
Two alrcratt 1urning in level llighl
•
FIGURE 5
Aircrah heading crosswind in s1eady lett 1urn
Let's return to the problem of an aircraft turning in strong wind conditions. Figure 4 is an aircraft making a steady, level turn, shown as it is
heading crosswind. The thrust and drag are
equal and have been omitted. The triangle of
velocities has been a dded, showing:
• airspeed and heading,
• wind speed and direction,
• ground speed and track.
0
As expected, the horizontal component of lift is
perpendicular to the aircraft's heading but it is
not perpendicular to its track. This force can
again be resolved into two components, A and
B. Component A is a tangential force causing a
decrease in ground speed. Component B is a
centripetal force causing curvature of the
aircraft's path across the ground. Notice that
the ground speed is decreasing even though
there is no change in airspeed.
A turning motor vehicle derives its centripetal
force from the action of tyre on road, so its
ground speed remains constant during a steady
turn. A control line model aeroplane derives its
centripetal force from a person stationary on
the ground, so its ground speed remains constant except for the consequences of the cyclic
variation in drag. Neither of these two bodies
experiences constant airspeed during a turn if
there is any wind. Helicopter rotor blades
derive their centripetal for ce from t he mast
which in forward flight is moving relative to
both the ground and the air, so neither the
ground speed nor the airspeed of the blades
remains constant. But birds, boomerangs,
insects and· aircraft are unique. When turning in
free flight they derive their centripetal force
from the air, so their airspeed does remain constant during a steady turn.
The airspeed of an aircraft will vary from time
to time for any one of a variety of reasons, but
turning downwind will not cause a decrease in
airspeed and turning into wind will not cause
an increase in airspeed.
�AviationSafetyDigest
Aviation Safety Digest
149
149
Confessions of
an undeserving
•
survivor
However, my instructor was demanding and
meticulous and I took a very responsible
approach to the precision of my piloting. I
believed that my dedication to flying by the
book in a crisp and precise manner would serve
me well and I wondered in amazement at the
folly of many of those I read about in the
Digests who entered cloud, distrusted their
instruments, gave way to senseless feelings
such as the 'certainty' that a wing had dropped
etc and ended their journeys in disaster. It
could never happen to me I felt. (I know, you
have heard it over and over again).
Lightning Ridge to Wagga type 140
Contribution by reader Christopher Hutchinson, an older
and not so bold pilot.
HE FOLLOWING stories are offered in an
attempt to get the message across that it
does not matter how serious a young pilot
might be about treating flying procedures with
the utmost respect and professionalism, he just
cannot expect to fly in cloud without appropriate training and get away with it. I am absolutely convinced of this, at last. I genuinely
believed that I had absorbed sufficient knowledge of others' experiences after reading
bundles of Digests to believe that I could never
fall foul of the strange phenomena that affects
one's brain when flying in cloud. I believed that
I had full control of myself, and therefore my
aeroplane at all times I flew and believe me, I
did pride myself on flying precisely, crisply and
always by the book. How wrong I was!
Young pilots must become convinced by some
means, other than a real-life experience, that
when inexperienced aviators enter cloud, their
bodies control their minds and senses no matter
how level-headed(!) they may otherwise be.
I have a son training as a navigator in the
RAAF, from whom~ expect a far higher standard of responsibility and honesty than I ever
asked of myself, so the letter from Senator
David MacGibbon and reply from Steve Tizzard,
Airflow, ASD 147, has after many years,
brought me to life; a life I might add that Steve
Tizzard might well - and with reason - say
that I have no expletive deleted right to still enjoy.
When I learned to fly, I lived at Lightning Ridge
and trained in clear Western NSW skies with
Walgett Aero Club. Under-the-hood sequences
were not on the prescribed syllabus in those
days and I gained my UPPL with little more
than a casual interest in the artificial horizon
and vertical speed indicator.
T
Why did I concentrate on the magnetic compass
with its inherent sluggishness on south characteristic? My mind was so literally clouded by
the situation that I didn't want to use the DG
because of its one-degree-every-half-hour
inexactitude. I wanted to be so precise in that
white environment that the DG which served
me so well in VMC was no longer accurate
enough! What a professional! I would not have
lived had I not had some training in full spin
recovery. What is worse, some of the very
much more responsible than I residents of
pretty little Temora might well have died with me.
It's a funny thing now, looking back on this
experience, to reflect on how quickly the eyes
and mind can work together to scan and record
the flight instruments. When the noise of the
increasing airspeed alerted me to my predicament, my hands and feet worked to get the
power off and centralise the rudder and re-trim
from the nose up trim set for the climb. In what
seemed to be milliseconds, the eyes left the
magnetic compass and scanned the full panel. I
can still see the airspeed nearing the red zone,
the altimeter reading 3 700 ft and rapidly
descending, the artificial horizon toppled, the
directional gyro rotating, the VSI, the ball etc.
etc. then the red corrugated iron!
hours on
Magnificent flight, clear skies, full SAR at 8 OOO
ft. Scattered Cu, tops around 5 OOO, started
about 30 minutes before Temora. Ten minutes
out of Temora I commenced a descent through a
hole in 4/ 8 cover. Arrived over Temora exactly
on the ETA but at 500 ft AGL to avoi,d scud. A
heavy shower was passing over Temora at the
time and conditions were bumpy and uncomfortable compared to the tranquillity and clear
conditions at cruise flight level. Despite the
rain, I cou ld see Wagga bathed in sunlight
about 30 nm to the South, compass heading
exactly 180. I had descended over Temora to
get a positive visual fix preparatory to the last
leg of the journey, as the countryside had been
bare of fixes for over an hour and I had no
navaids. To proceed directly towards Wagga at
500 ft AGL in rain and scud looked dangerous
so I elected to climb through a hole in what
now looked to be about 7 / 8 cloud, to climb back
to the original altitude expecting then to be in
clear sky all the way to Wagga. I trimmed the
aircraft at about 500 ft/ min rate of climb, controls centred and concentrated on holding heading on the magnetic compass. At about 1 OOO ft
the hole in the sky closed and for the first time
in my life I was flying in cloud.
0
No way I thought, will I get flustered. Hold the
heading on the magnetic compass, keep controls
centred, altimeter is showing steady rate of
climb, airspeed looks fine, little aeroplane in
AH looks level but ascending. No problems, just
hold that heading.
Compass swung a degree off course so I gave it
a little right rudder, just a little. I kept the control column centred. Funny thing, but the compass swung a bit more off course so I gave it a
bit more right rudder and again, and again ...... .
At exactly 3 700 ft the noise of increasing airspeed drew my attention from a singular fixation on the compass problem and the fact that
I now had on full right rudder. I arrested that
spiral dive by centring the controls, cutting off
the power and raising the nose as the airspeed
decreased. The aircraft levelled as I broke
through the scud just above the rooftops of
Temora. I will always remember that red galvanised iron.
0
Walgett to Lightning Ridge type 150
hours on
Fourth trip of the day, bringing food to our
store in floodbound Lightning Ridge. A trip I
could do with my eyes closed. Almost every
flight I had ever flown had included a Walgett
- Lightning Ridge leg. Departed Walgett with
full tanks in light rain but fair visibility about
one and a half hours before official last light
but decidedly less in reality due to weather.
Rain increased and visibility reduced on route
and aircraft was subject to severe buffeting and
most of flight was conducted at 500 ft AGL to
maintain reference to ground features. Lightning Ridge was not on the nose at the time it
should have been and surrounding countryside
gave no clues to its direction. Flying by the
book, I opted for the reciprocal heading to get
me back to the point where I last had a positive
fix, namely Walgett. I thought about winds, but
due to the conditions there were none of the
usual features that I knew of that would give
me any indication, such as dust behind cars,
smoke from fires, ripples on dams. Just rain,
buckets of it rushing up the windscreen. However, the VFG said fly a reciprocal heading
when lost. I saw the Barwon River as I crossed
it but the familiar silos around Walgett were
nowhere to be seen. Absolutely nowhere to land
on the flood-drenched country. Not a road in
sight. Back to the Barwon river, the only
earthly feature I recognised. I could use it to
find Walgett only if I knew which side of
W algett I was on. Otherwise I would be heading
for either Brewarrina or Collarenebri without
sufficient light to reach either. I guessed and
turned towards Brewarrina in minimum visibility. I guessed wrong and never passed
Walgett.
I elected to ditch in the Barwon but could not
find a straight section free of trees. Yet the
Barwon looked a better place to land than the
tree-studded and flooded countryside. Visibility
was about 200 metres from about 200 ft AGL. I
continued my search for a straight bit of river
when I overflew a homestead with a sodden
dirt road in front. I elected to land on the road
in front of the homestead, expecting the nose
wheel to bury in the mud and the aircraft to
turn over. At about 50 ft on finals, in near
darkness, I realised that I was about to land on
the backs of a flock of sheep that were running
along the road under me. I decided to fly a circuit at 50 ft AGL and land as planned, hoping
the sheep would be gone. Then, as I turned
crosswind for my chosen place to die, I passed
over a long row of white painted tyres and a
windsock on higher ground adjacent to the
homestead!
I landed and I lived on. I had in fact flown
through a squall (the buffeting) enroute Lightning Ridge. I was 12 nm off track when I
reached what should have been Lightning Ridge
and 24 nm off track when I reached the Barwon
after flying the reciprocal heading to W algett.
Yes, Mr Tizzard, I know that you will be saying
that I deserved to be amongst the sheep in that
flock West of Walgett, and who am I to argue?
�Aviation SafetyDigest
149
Aviation Safety Digest
149
ICAO airspace
- a positive
•
view
Ben Schiemer, FOi (GA)
Introduction
HE ICAO AIRSPACE classification system
is contained in Annex 11, Amendment 33.
The system was adopted by ICAO on 21
March 1990, and under our agreements with
ICAO Australia is obliged to implement the
classifications or to register differences. If we
so chose we could register so many differences
as to reflect our existing system rather than
adoption of the ICAO airspace classifications,
but this would be done only if we were convinced that our existing system was superior to
the incoming ICAO system.
We are in an international environment, and
standardisation brings its own safety benefits,
so we cannot stick with what we've got just
because it is too much trouble to change sooner or later the change must come, and CAA
is on balance sure that the change will not
degrade safety standards if we can get pilots to
concentrate on the changes until we all become
used to them. The new system is in fact simpler
than the existing system, and carries fewer
illusions about the nature of our safety net.
The objective of any form of organisation of air
traffic is to en able flying activity to take place
with the minimum chance of collision. With the
introduction of ICAO airspace classifications,
pilots will find few changes in the way they
operate in CT A, apa,rt from some s implification
in flight planning and notification, especially
for VFR.
Outside controlled airspace we currently rely on
self-separation based on a combination of direct
and indirect movement advice and see-andavoid practices. Not all aircraft carry radio,
and in 'remote' AFIZs it is a fair guess that not
all movements are reported. It is worth remembering that the present system does not in any
way guarantee safe separ ation - as we all
know, the worst case for operations OCTA is in
higher traffic densities, where the present system can quickly overload and become markedly
reduced in effectiveness.
T
Under the ICAO system, traffic advice from
ATS will not be available at all in Class G airspace. We will be relying on other pilots - and
they will be relying on us. We were anyway of
course, but FS made it feel like Big Brother was
looking out for us. In controlled airspace, VFR
aircraft will be given more flexibility and
responsibility for their own separation,
although clearances will still be required.
The procedures to be adopted under the ICAO
airspace classification system are being
addressed elsewhere, so I will confine myself to
some background ideas that may help us make
the most of what we are to get.
It is my belief that a network of measures can
be constructed to achieve equivalent safety in
the new airspace. Many of the things I will
suggest would equally enhance t he safety of
operations in the current airspace, but the fact
is that they have not been widely addressed in
the past.
r
Some Ways to Improve Safety OCTA
To improve safety, what can influential aviation personnel (FOl'S, ATS officers, ATO'S,
CFI'S, Instructors, senior pilots and industry
managers anywhere) do? Here are some
recommendations.
• Speed. Reduce speed in terminal areas - a
study h as shown that see-and-avoid is 97%
effective at closing speeds of 100-200 kt,
reducing to 47% above 400 kt. In addition to
the 250 kt limit below AlOO I h ave proposed a
limit of 200 kt below A050 for all public
transport aircraft.
• Workload. Particularly in bigger aircraft,
ensure that approach checks are done outside
15 nm and above AlOO. When OCTA, try to
have no FMS/GNS/ IRS manipulation and minimise other checks on taxi and in flight below
AlOO.
• Aircraft. Discourage use of aircraft with poor
visibility from the cockpit, disorganised or
unnecessarily complicated instrumentation,
high angles of incidence at low speeds, complicated checks and etc. Among light aircraft, I
give the Baron three out of ten and the Beech
76, nine. Among jets simple is safe - lots of
toys are a disadvantage, as is sweepback, big
pillars and posts. Checklists, maps or devices
should not be placed on the glare-shield of
any aircraft.
• Radio. Encourage carriage and use of radio. If
there is no statutory requirement, a hand-held
radio can be carried instead of a certified
radio unit and can be used to good effect prov ided its power (range) limitations are understood. Studies show t hat a traffic alert greatly
enhances see-and-avoid practices, and longrange communication is n ot usually critical. In
addition, instructors can reduce the formality
of radio without turning it into a CB by teaching the objective of a radio call as the first
priority, and the form of the call second.
0
• Lights. Promote strobe lights at all times and
within (say) 10 miles of any significant aerodrome insist on the use of landing and taxi
lights below AlOO.
• Evasive Manoeuvre. How many of us have
practised the standard manoeuvre? Not many
I guess, and still less have practised it enough
to overcome the reflex dart to the left t hat we
use driving to work - practice may save us
those fractions of a second that could mean
the difference between hit or miss . The
manoeuvre should be in every t raining s yllabus, and tested in every flight review.
• Accuracy Versus Lookout. We all strive for
flying accuracy. With 500 ft vertical separation as the norm we had better be good at it
- flying accurate altit ude needs to be
emphasised in our training and checking. But
what about lookout versus flying accuracy at
MDA or in the circuit? It is easier to rate flying accuracy, and I would venture most check
pilots mark down the pilot who does not fly
accurately in those circumstances, without
assessing lookout with equal stringency: perhaps a change of culture is in order.
• Letdowns. Instructors s hould ensure that all
pilots are made aware of instrument letdown
procedures, so that pilots are always well
aware of what an IFR aircraft is likely to be
doing.
• Clock System. Int roduce the clock system of
aircraft location at the initial phase Of flying
t raining and keep it in use. How many of our
students a nd co-flyers can look at another aircraft and tell the other pilot our relative position, clockwise?
• See-and-Avoid. Introduce into air studies see
and avoid and its limit ations. An excellent
BASI study on the subject will soon be in print.
I am confident that if t hese ideas were put into
each t raining syllabus and firmly established as
part of our flight culture, the air would be
safer after ICAO than before. There mu st be
many more ideas out there - let's hear them.
The advent of the ICAO airspace classification
will not greatly change the way GA operates.
Just as most of us could do it better now, we
can do it better under the new r ules, for we are
t he ones who either enhance or degrade safety,
and that won't change much whether we u se
t he old or the new system.
ASD merely comments that there is n ot a lot in
the preceding paragraphs that pilots ought not
already to be meticulous about, anyway.
0
What's the 'arm
in it?
pilot contribution by Raymond M Johnstone
RIDAY WAS CLOUDY - no good for photography - so I took advantage of the day
to have the engineers check out a persistent
oil leak from no. two engine. To save labour, I
de-cowled the engine for them.
After lunch, I returned to the airport, checked
their work and re-cowled the engine. All that
remained was to wheel the aircraft back from
the hangar and taxi it to dispersal.
The aircraft was parked on a slight rise, so I
released the brakes, removed the chocks, then
gave it a gentle nudge so t hat it might start
rolling down the slope. I'd done this many t imes
before.
The aircraft quickly gathered momentum, so I
threw a chock under the mainwheel, which
went CLUNK right over it. Behind, parked at
right angles to our path , was a Cessna 210 and
I h ad visions of my aircr aft's tail collecting it
amidships.
So I used the only tools available - my hands
- in an attempt to avert an accident. The
F
0
• Transit. VFR pilots should avoid planning
t ransit over busy aerodromes or nav-aids. Try
to go where others aren' t!
nosewheel tyre quickly picked up my hand and
fed it throu gh the gap at the top, gouging out
part of my hand in the process. My w rist and
forearm quickly followed. By this time, I had
become res igned to liv ing the remainder of my
life with one arm, and the t hought crossed my
mind that this therefore superfluous piece of
flesh and bone might make a u seful tool to
retard the motion of the aircraft, by acting as a
wedge.
The h ypothesis proved correct and the aircraft
stopped. Fortunat ely, ther e had been sufficient
friction between rubber and fore arm skin to
stop the aircraft before my elbow was
crunched, so no permanent injury was
sustained.
Apart from my stupidity in allowing circumstances to evolve in the first place, t he most
intriguing aspect of the experience was this
t hought: what evolutionary process or history
of self-preservation so prepared me t hat a part
of my body could be sacrificed and instantly
recognised as a tool?
ASD makes no comment on the writer's philosophical question, but hopes that this grisly
story will help prevent similar incidents. We
asked the author for a re-run of the incident,
for the benefit of our photographer, but he
declined ...
�-,
Aviation Safety Digest
149
Not much damage here...
Aviation Safety Digest
149
The aeroplane made a complete 180 before it
struck some trees , where it cartwheeled and
crashed upside down. As a result of the crash
and the leaking fuel the machine caught fire a fire so intense that no one could approach to
help. Three people died a most terrible death.
And this was supposed to be fun.
It was lucky the aeroplane did not end up in
someone's house, for people on the ground also
h ave a vested interest in how safely aircraft
are flown.
Some operations - crop spraying, cattle must ering and power line inspection, require the
pilot to fly at low level. Pilots engaged in such
operations are required to undergo special
training in order to conform to the requirements of CAR 157. The training covers pitfalls
and dangers encou ntered at low level and how
best to counter them. False airspeed perception,
wires, and terrain avoidance requirements -vavailable aircraft performance are among the
dangers emphasised. Engine failures are demonstrated and pilots are taught the best way to
conduct a forced landing with the little reaction
time available . These emergency drills are then
practised (for a basic agricultural licence some
40 hours of intensive flying is required) until
all pupils are justly confident of their ability.
The armed forces h ave a particular requirement
to fly at low level. Even thou gh ser vice aircraft
are sp ecifically equipped or even designed for
the task, the military rely heavily on comprehensive low level training, close supervision,
regular check flights and a large array of
restrictive orders to ensure that t h eir operations are as safe as possible. Every low level
sortie is preceded by meticulous planning, a full
briefing and careful vetting before the flight is
cleared.
Low flying
CAR 157 (1) An aircraft shall not fly over any city town or
populous area at a lower height than 1 500 ft, or any other
area at a lower height than 500 ft.
Rod Beneke, FOi (GA)
AR 157 was written , along with other
Regulations, as a result of the accumulated
experience of many pilots, and after many
unnecessary and tragic accidents .
Have you heard of Cobber Kain, a New Zealander and an ace in the Royal Air Force in
WWII? He died not as a result of enemy action,
but in the conduct of unauthorised low flying.
He was doing a beat-up to impress his friends.
They were all very impressed and the best
came at t he end, when he hit the ground and
killed himself.
And how about Bluey Truscott, DFC and Bar?
He was an RAAF ace. Bored with operating
from Exmouth after the ex citement and drama
of battle in Europe and the Pacific where he
claimed ma ny kills, Bluey decided to do a few
mock attacks on a Catalina h e was escorting to
base. Unfortunately on the last attack Bluey
didn't realise the Cat was about to land - and
it is almost impossible to judge height over
smooth water. Despite frantic last-minute calls
of 'Pull up , pull up!' from his w ingman, Bluey
hit the water at high speed and was no more.
These accidents, and alas there h ave been
innumerable others before and after, were
caused by highly trained pilots attempting
impromptu, unplanned low level flying.
'But', you might say, 'they were a irforce pilots .
That sort of thing does not happen to civilians,
right?' - Wrong! How about this, it happened
late last year:
Five pilots together with the family of one of
them flew in t wo aeroplanes to an outback
town in New South Wales for a weekend away.
On the Saturday and Sunday mornings bot h
aeroplanes were observed carrying out low flying activities. On Sunday afternoon a couple of
the pilots decided it would be good fun to try a
little low level bombing using flour bags. The
target was to be in front of the hotel. The first
pass, at around 50 ft, resulted in the bomb
overshooting t he target. Never mind, let's go
round again for another go. The second pass
was below 50 ft and it appears the flour bag
jammed in the window through which it was to
be dropped.
The spectators in the h otel saw both pilots trying to release the flour bag and were hor rified
as t he aeroplane entered a steep climbing turn
to t he left. The bank angle increased to over 90°
and t h e port wing buckled as it collided with
the roof of the court house.
C
c
Flying at low level is dangerous, even for the
trained and qualified pilot. It introduces a number of new and pressing problems. Here are a few:
The altimeter is useless for indicating height
above the terrain . The usual setting we use on
the a ltimeter below transit ion altitude is QNH.
This setting enables the a lt imeter to indicate
height above mean sea level within a limit ed
area, and takes no account of the elevation of
the s urrounding earth or water surface (lakes
are rarely at sea level). It can be difficult to
judge your height above the terrain, because
t he size of surrounding objects can deceive.
What you think is a large tree can on occasion
turn out to be a small salt bush. This is particularly a problem in redu ced visibility and where
t here is no clearly defined horizon.
Changes of contour can be very deceiving and
you can rapidly run out of airspeed as the aircraft climbs up a gr adient y ou h ad not detected.
For the average light aircraft, you will b e surprised how shallow that gradient is.
Because of the lack of visibility it is not difficult get lost when flying at low level. This is
a lways embarrassing and can be more than
slightly fatal.
Wind can cause problems. If it is strong it can
cause t urbulence downwind of obstacles, even a
line of t rees will do. This turbulence could
result in loss of control, to the extent that your
aircraft might even hit the ground. Remember
some of the hairy approaches to land you have
made in windy conditions? Well, they are not as
exciting as the conditions you will find attempt ing to fly at really low level.
�Aviation Safety Digest
L.....J---.........
AviationSafety Digest
149
149 ~.~
Turbulence can be severe, especially near
rising ground. A downdraft over a mountain
can reduce your maximum rate of climb to zero
or even a descent. When the ground in front of
you is rising this is not good. Is there enough
room to turn around before you hit the ground?
Have you been practising maximum rate or
minimum radius turns lately? You may need
this skill if you find yourself trapped in a valley.
Drift becomes very apparent at low level, your
aircraft points in one direction but goes in
another and so you could be caught out when
trying to avoid an obstacle. The larger problem,
though, is that of perceived speed. At low-level,
there is a strong tendency to judge your speed
by movement of the ground below, rather than
reference to the ASI. An aircraft flying into
wind will seem slow. If you then accept this
slow speed as normal flying downwind, or
indeed when making a turn, you may well stall.
Groundspeed and IAS are not the same. How is
your low level stall recovery technique? You
have probably never seen such a manoeuvre, let
alone received any instruction in the art. Your
first stall could be the last!
Another problem associated with perceived
speed is that you seem to be going faster the
lower you fly. We certainly have a dangerous
mix here. Turning adds more problems, drift
during the turn, apparent slip or skid, and inertia.
Aircraft inertia is interesting. Because your
aircraft has mass and motion it responds to
Newton's laws. One of them says 'a body cont inues at rest or in uniform motion unless acted
upon by an external force'. Therefore, your aircraft will continue along its path in both the
horizontal and vertical planes until acted upon
by a force, in this case the aircraft controls.
However, the effect of control input is not
instantaneous, and although aircraft inertia is
not evident at higher a ltitudes, it is a vital consideration when close to obstacles.
Before the controls overcome this inertia, the
aircraft for a short time continues along its
original path. Low-level, therefore, you have to
commence your avoidance manoeuvre early,
otherwise you might make Sir Isaac's day.
Again, you have to pull up from a dive sooner
than you would expect, especially if you are
fast . Are you experienced in just how much
extra to give it? Would you - do you? - bet
your life on it?
Flying over large stretches of water at low
level is also fraught with danger. It is
extremely difficult, (ask Bluey) if not impossible to judge height when flying over calm,
glassy water, particularly in hazy conditions
where there is no clear horizon. Climb to the
top of a high diving board and look down at the
pool below. If the water is still you will see the
problem, or rather you won't see (check diving
competitions on TV and you'll note the jets of
water that ensure the surface of the pool is
ruffled). Real pilots would never fly below 500
ft over water without a radar altimeter, preferably with some sort of head-up warning. Is
your aircraft thus well-equipped?
There are other problems related to flight
below 500 ft - engine failure and forced
landing, turbulence due to thermal action, aircraft fatigue, navigation problems, the difficulty of seeing wires until it is too late and
many more. This short article cannot deal with
them all and is not intended to. It is rather to
persuade you not to try unauthorised low flying, for your life's sake.
Flight at low level in contravention of CAR 157
means flying in an environment in which you
have no training or recent experience. A lack of
either makes you incompetent for the task. You
are putting yourself and your passengers at
risk, and endangering the lives of people on the
ground. You almost certainly will be causing an
unnecessary disturbance, and in my opinion it
is one of the occasions when use of the full
force of the law is justified.
In the last two years in Australia at least eight
people have died and a further eight have suffered severe injury in nine accidents caused
because the pilots decided to break the law.
This sad toll was totally unnecessary, the result
of bravado and incompetence. As a n industry,
we all must labour under an image which is
constantly tarnished by fools and incompetents.
We can not afford this, in either human or
economic terms. Low flying is not an activity
for amateurs, so for all our sakes please leave
it to t he professionals, and enjoy a higher probability of living to old age.
Advanced air
traffic
systems agreed
by John Wright
Assistant General Manager
Airways Transition Program
I
0
Rod Beneke spent his formative {flying) years
over the length and breadth of Europe at 450
kt, 250 ft day/600 ft night
Class A IFR aircraft only,
positive separation provided
- - LOW FLYING to
Class B orC
Positive separation provided
•
The
Professionals
(
N THE PREVIOUS Autumn issue of the ASD,
it was mentioned that the AMATS proposals
were subject to extensive consultation with
industry and that some of the detail contained
in the articles had been overtaken by events.
The major focus of the debate has been the services and procedures appropriate to airspace
which is currently uncontrolled.
Taking account of the views of industry, the
CAA was able to announce during April that
the international airspace classification system
would be adopted. When the new system is
fully implemented a separation service will be
available to pilots flying under IFR in areas
that are currently uncontrolled and there will
be vastly improved services for aircraft in busy
areas through the extended use of radar. The
airspace management plan and the two centre
system will be known as The Australian
Advanced Air Traffic System (TAAATS).
It is now planned that the Class E separation
service will be provided by ATC throughout
Australia by June 1994. A Flight Information
Service will be available to all across the whole
country involving similar VHF and HF coverage
as offered today but not including a traffic
information service.
The CAA intends that the introduction of The
Australian Advanced Air Traffic System will
take place progressively from December 1991
until the end of 1995. We also fully appreciate
that we will need to provide timely in,formation
to pilots on the changes prior to introduction.
The next issue of the Aviation Safety Digest
will contain a selection of articles relevant to
the first changes which are scheduled to come
into effect from 12 December.
Among the changes planned for December 1991
are:
• the base of the control area over Australia
will be lowered from FL245 to FL200;
• the !CAO hemispherical table of cruising
levels will come into effect;
• traffic information (other than information
about VFR flights) will continue to be available to IFR flights outside controlled airspace;
• full reporting will no longer be available to
VFR flights. SARTIME will be;
• radar advisory services will be introduced as
staffing and facilities permit;
• all VFR aircraft (except gliders) will be
required to carry radio and be prepared to use
radio when flying above 5 OOO'. (}liders will
be expected to comply whenever possible;
• all VFR aircraft will be required to carry and
use radio when within the prescribed distance
(usually 5 OOO' and 15NM) from an airport
with a Mandatory Traffic Advisory Frequency
(MTAF);
• a Common Traffic Advisory Frequency
(CTAF) will be notified for a ll other licensed
airports;
• new VMC minima will be notified; and
• VFR GA flights will not be required to submit
flight notification to the CAA other than for
flights in controlled airspace above 10 OOO' .
The Aviation Safety Digest will be a valuable
source of information for pilots but I would ask
pilots to consider the benefits of ensuring that
they have access to other documentation particularly Class 2 NOTAMS, AIP/MAP and ERSA.
0
A~::Y :o::n~t: :a~r ~:s _
Class C
IFR - positive separation
VFR - traffic advice and conflict resolution
__
~
Class E
IFR aircraft separated
and given VFR traffic
Carriage and use of Radio required
----~- -- - -rM;,-FT
STOP PRESS !! /n lhe last six rronths, there have been re,xxted32 aai:Jents rorreming low- flying. Eighteen peq:ie (25 if you irdlXie
lhe BeD200 on Marcil 2) have loot their /Nes.
A summary plan of the new airspace and services
__ _
A
oso
�
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Aviation Safety Digest, number 149 (Winter, 1991)
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149
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1991
-
https://collections.heritageoftheair.org.au/files/original/731385a39ae688490f6d67737f785c74
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~
Remember, wheth er IFR or VFR, when you con see outside - look outsid'
KEEP THAT SCAN GOINGI
Note: Even when in controlled airspace and in a radar environment, all potential collision risks may not be known to the controller.
Civil Aviation Authority
AUSTRALIA
�Aviation Safety Digest is prepared and
published by the Civil Aviation Authority. It is
distributed to Australian licence holders
(except student pilots), registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Editorial
Contents
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
4
Classic beauty -
Manager, Publications Centre, P.O. Box 1986
Carlton South, 3053, AUSTRALIA
Telephone (03) 342 2000(4 lines); 008 33 1676
008 33 4191; (03) 347 4407
5
Play the percentages
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The articles
are intended to serve as a basis for discussion
and even argument in an effort to identify and
resolve problem areas and potentially
hazardous situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the material without altering
the author's intended meaning.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
.
G.P.O. Box 367,
Canberra, A.C. T. 2601, AUSTRALIA
Telephone (06) 268 4583
6
'89rs'
8
Heavy landings
classic blunder
10 Search and Rescue - Alerting
12 A little learning is a (very)
dangerous thing
13
Weatherwise flying
14
Airflow
18 Field Office Forum
Danger in numbers
Acknowledgement to Qantas for material from
their Cockpit Resource Management Course
19 Nil Defects
22 Ground to air
Personal standards, airworthiness,
airmanship, confidence - good marks
here mean safe aviation.
Personal standards - Do some of us really feel
happy at accepting minimum standards? More
important, perhaps, what do the rest of us
think of others who may be sharing the same
intimate airspace and at the same time
re-learning to ·fly? '89r s' suggests that all too
often this may be the case and we could be flying adjacent to a pilot who is always a minute
or so behind the aircraft.
Airworthiness - Corrosion can not only
streamline your bank balance if you're an aircraft owner, but if you're the pilot as well it
could comprehensively spoil your day. Therefore, have another look at the woodpecker
nestholes in the old tree on the front cover,
read the article inside, then go and check your
aircraft. Hopefully there will be no correlation.
Covers
Front: 'From wing main spar - Cessna 1858'
Photograph: CAA Materials Laboratory
Back: 'See and Avoid' by The Artworks
Airmanship - a sub-set of personal standards:
'risk-management' if you like. Certainly 'Heavy
Landings' is a graphic description of the sort of
chain of events that might lead to sleepless
nights ... or a smoking hole in the ground. If
you even only 'think' there's something amiss,
please be an adult and make it known. Which
leads us nicely to:
Confidence - CAIR (are they really con fidential?), requests for assistance (surely the world
will know!) - both forms of communication
must be encouraged if aviation safety is to
flourish. I talked about CAIR in ASD 145; here,
our Group General Manager is at pains to
reassure pilots that confidentiality in these
matters is really absolute; if you get yourself
into trouble (not, of course, by deliberately
flouting the rules) the CAA may subsequently
feel moved to offer advice and direct you to
appropriate training, but it will not, repeat not,
indulge in a dabbing-in exercise.
Roger Marchant
Lyn Coutts
Editor:
Sub-Editor:
©Civil Aviation Authority 1990
ISSN 0045-1207
Printed by Ambassador Press Pty Ltd
51 Good Street. Granville, N.S.W. 2142,
AUSTRALIA
Diagrams:
P11
P20&21
Kathy Foldszin
Cartoons:
Pl
Jeff Bolinger
Soussanith Nokham
P12
Photographs: P4
PB
Stan Tilley
Richard Sibly
�.4
Aviation Safety Digest
147
Aviation Safety Digest
- 147
Classic beauty
classic
blunder
Pilot contribution by Stan Tilley
0
IL CAP TIGHT; cowl buttons done up;
hand lightly on the propeller (No! the
engine does not need pulling through it's already flown today) CLICK - ROAR!! the
engine bursts into life, the plane jumps the
handbrake and careers across the aerodrome.
As it moves I frantically dodge the scything
propeller and leap for the cockpit. No good! I'm
knocked flat as the plane drives over me,
bounces off a fuel bowser and continues on
through the boundary fence.
Damage? Considerable to the wings and
undercarriage, not to mention the fuel pump,
five stitches in my hand and massive bruising
that made it difficult for me to walk even three
weeks later.
But, as you might guess, the deepest laceration
was to my confidence and self-esteem. How
could I, with over 20 years' and three thousand
hours' experience, make such a Bloody Stupid
Mistake, smash my super little aeroplane and go
desperately close to writing myself off in the
process?
Bad Luck? - No way! If luck had anything to
do with it, it was good luck that no other
people or aircraft were involved, and amazingly
good luck that the fuel installation did not
explode .
So why or how did it happen?
0
The accident occurred around half an hour
before last light. Very early that morning
another pilot had flown the aeroplane, then
about 10.30 I had taken it out of the hangar
once more to wash it down and complete a
'daily' in readiness for a planned trip to a destination about 100 miles away, where we were
due to stay for a few days.
I had also arranged for a car to be driven to the
same place for local use once I had arrived, so I
interrupted the daily to deliver the car to my
driver, since it was twice the time by road.
However, it all came to naught as the driver
went sick. So, no panic, the whole thing was
put off for 24 hours, allowing me to put some
valuable work time in.
I finished late in the afternoon and returned to
the 'drome to hangar my aeroplane for the
night. Needless to say, it was a magnificent evening and the temptation for a last-minute local
flight was just too great. A quick 'walk-round',
fuel dip (I h adn't refuelled previously), climb
in, buckle up, commence prime for cold fuel
injection start - throttle open - mixture rich .
.. hold on, I had decided earlier that some oil
was necessary - had I replaced the oil cap
correctly and closed the cowl? . . .Unbuckle,
climb out, check oil cap tight, cowl done up,
hand 'lightly' [lightly? - ed] on the prop CLICK - ROAR!!
i
Hindsight:
So where do we go wrong?
Perhaps the most frightening thing about this
whole disastrous incident was the number of
pilots who admitted the same thing had happened to them. Certainly in the majority of
cases the results were not serious - sometimes
almost funny (the Partenavia going around in
circles with one engine running or the pilot
hanging on to the tail of the Decathlon come to
mind). Others were not so amusing, like the
scarred and twisted arm carried by a pilot as a
perpetual reminder of his folly.
With many of us it was part and parcel of our
training to pull the engine through to break the
oil seal, check compression and prevent damage
caused by a possible hydraulic lock. With the
old inverted Gipsy and the smaller radial
engines this is certainly still a recommended
procedure, but now most modern engines are
horizontally opposed. I therefore ask the serious question:
In every case the common denominator
was a hand on a 'live' propeller.
What is more dangerous - to pull a
motor through or to risk damage by confining the propeller preflight to a visual
inspection only?
Were these stories true or were my fellow pilots
merely trying to make me feel better? I think
they were true; in fact, the reports were often
prefixed with 'Well, now it's happened to you, I
must admit .. .'
I know what I'll be doing from now on!
Play the
percentages!
Pilot contribution
'Nothing puzzles me more than time and space; and yet
nothing troubles me less, as I never think about them'
(Charles Lamb)
V
u
ERY MANY light aircraft pilots list 300
minutes as 'endurance' on their flight plans.
But do they really have this?
In an emergency situation, an incorrect figure
can have drastic effects. My plane has an
endurance of 360 minutes at cruise but I always
(used to) insert 300 and calculate fuel purely
by time. I rationalised that the extra 60 minutes
would be a bonus in hard times and great in an
emergency. WRONG!! That extra 60 minutes
can result in catastrophe. How can extra fuel
be dangerous?
In an emergency situation, eg becoming lost at
night or encountering IMC on a VFR flight, you
· advise ATS of your predicament. Your
endurance is 300 minutes (it's there on your
FPL!), and perhaps you have been flying for
240 minutes, say to your destination then half
way home; ATC/ FS may only be able t o advise
you of a suitable location to force-land, or
vector you to an airstrip that is far from ideal,
because as far as they are concerned you don't
Any other first-hand experiences? -
ed D
have enough fuel to go to a suitable alternate
aerodrome, perhaps only 30 min away, and still
retain the 45 min fixed reserve. Nor are they
able to have you climb clear of cloud and/ or
l:mld. That extra 60 minutes fuel you'v e
carefully t ucked away becomes nothing but a
hazard. Whereas it could have sav ed y ou and
your plane w ithout difficulty, now it may be a
sentence rat her than a bonus.
So, the only sure thing you know about your
endurance is the quantity of fuel on board.
Write it down! Fuel flow per hour at cruise
should be known, so fuel burned off for the
duration of the trip can be calculated. 45
minutes' fixed reserve (at cruise power) is
easily worked out. 30 minutes' holding at a
capital city? This would not be at cruise but
may be down around 45%. Determine the flow
rate and insert this. Taxi and run-up? No time,
but insert an appropriate fuel quantity.
Subtracting the above amounts from your initial
fuel load, then dividing the result b y the fuel
flow at cruise gives you y our actual margin.
Endurance is then the sum of fuel required and
t h e margin, translated into time.
OK, so this may take a few more minutes on the
ground, but the few more minutes you squeeze
out of your calculations could save your life in
t h e air!
All that I can add to this is a common-sense
reminder: if, for any reason, you calculate that
your endurance has changed, tell the Air
Traffic Service you are currently working.
Armed wi th up-to-date information, they can
offer you the very best opti on if things go
wr ong D
�Aviation Safety Digest
147
Aviation Safety Digest
147
Steve Tizz ard (E of A, GA) observes:
'89rs'
Just like most of you should, I work for a living and have to support my bad habits by a
lot of compromise. My recreation has been
cut to one half-price movie a week or a Friday night home video marathon with Pizza
Hut doing the catering. So when it's time for
me to squeeze in a fortnightly flurry of circuits or a condensed airwork routine, the last
problem that ATC or any other pilot wants is
to be baby-sitting an 89'r.
What's an 89'r you ask? You know who you
are. You're the ones who fly once every
eighty nine days or so attempting to maintain
some kind of currency. If you're that desperate, give me your name and address - I'll do
us all a favour and send you fifty bucks to
stay away from airports. You aren't pilots,
you're accidents about to happen. You wildguns make me nervous; take up sailing - it 's
cheaper and safer. Or how about all you fairweather IFR 89'rs, you're my favourites. At
least I've got enough sense to stay home on a
lousy day and do the domestics ... right
dear? Generally speaking, pilots are supposed
to be an intelligent group of people: I'm convinced otherwise.
pilot submission from Jeff Bolinger
VER THE YEARS I've learned that practice nudges towards perfection. Not that
I've reached such a height; nevertheless,
it's nice to know that persistence pays off.
On the other hand, little or no practice
results in poor performance and this I can
relate to.
0
In the flying business minimum practice
qualifies you as a safety hazard teetering on
the edge of danger and disaster. Your horoscope probably reads; 'Day Wrecker' . Those
of you shaking your heads in protest save
your breath. You can kick and scream all
day, but the truth is you know when your
flying is sloppy. That excuse you call a landing proves that you're way over par for the
course. Yes, it's you they're all pointing and
laughing at . . .
Being a married man, I tossed away my ego
years ago and have no trouble admitting that
I have to work hard just to reach a comfortable average. So I'm not a natural-born flyboy, and nor are you unless there's plumage
sticking out of your backside and you
resemble 'Condor Man' . There's nothing
wrong with being average as long as you are
at a safe level of proficiency; that means r egular practice.
To waste thousands of hard-earned dollars on
a flying fantasy instead of buying a house,
two cars, or a three week holiday in Hawaii
is absurd. I don't care how much the nut next
to me on the run-up bay loves t o fly so long
as when our hero is turned loose, he's safe.
After all, safety's the issue here .
Now, to raise an issue without offering a solution is kind of like waking a hungry lion
with no intention of feeding it. So how about
changing biennials to annuals and requiring
three take-offs and landings every thirty
days instead of ninety days. That'll keep the
real pilots in the air (and, more important,
the corollary to that assertion). Sure, the
89'rs will become 29'rs or Parker pen pilots
- no system is flawless; however, with any
luck they'll get tired of it and lose interest. If
you're going to fly mate, FLY. If not, give it
away.
On the way home from the airport this afternoon I was nearly forced off t he road by this
lunatic driver. As he roared past me I caught
a glimpse of his bumper sticker. It read, I'd
rather be flying. I could only pray that when
this idiot bought the car, the sticker was
already on it.
Sadly, the scenario painted by Jeff is all too
often true: most low-time pilots who fly a
mere three circuits per ninety days maintain
little more than 'theoretical' currency. They
may get some form of satisfaction from their
legal currency, but in truth they are proficient only in the circuit and in the best of
weather. I shudder to contemplate them
facing any sort of airborne emergency.
Part 40 of Civil Aviation Orders is a distillation of many years of both national and
international regulatory experience. It sets
out the minimum exposure to certain operations deemed necessary for a pilot with
average skills and knowledge. It goes without
saying that this minimum cannot be expected
to guarantee a safe performance under all
circumstances and it is fortunate that most
organisations hiring out aircraft require
more evidence of competency than could be
OruE... TWO ... \\--\R~E ...
B(AO~
l'I"\ GcnD FOR
offered by an 89 'r before they let someone
take charge of an expensive piece of
equipment.
As a former full-ti m e GA instructor I sympathise wi th the suggestion that 89'rs become
29'rs and that BFRs become YFRs. However,
although accident statistics do not support
this point, performance figures might well
indicate that modern lighties are relatively
forgiving contraptions, and many 'pilots' kid
only themselves as to their personal flying
competence.
For persistent 89 'rs I suggest the answer is
not with Big Brother and more regulation
(refer our Chairman), but in your own
hands. That hard-earned money will be better spent in regaining currency via a good
session of circuits (normal, glide, flap less,
STOL), all in a decent crosswind and with an
instructor. You will be amply r ewarded by
the discovery that your skills leave a lot to be
desired D
�Aviation Safety Digest
147
()
Heavy landings
(extracted from a pilot report)
HE INCIDENT appearing on page 13 of ASD
142, concerning unreported damage to the
left undercarriage of a P A28, reminds me of
an almost identical incident.
It was a NVFR flight under the supervision of
an experienced flyi_n g instructor, for the purpose of regaining currency after about 12
months since last I flew at night. The trip was
to include a series of touch and go landings.
The first landing was heavy due to a misjudged
flare, caused in part by my being distracted by
the late departure from the runway of a preceding aircraft. The flare was such that the flying instructor apparently did not contemplate
assuming control, and t he landing aroused comment from neither him nor an experienced back
seat passenger. To my surprise, the aircraft did
not bounce after touchdown. Nothing was said
about th e severity of the landing; all on board
considered it to be within reasonable limits.
T
Certainly, I have at various times observed
other pilots make apparently harder landings,
both in this and other. aircraft. During the
debrief the instructor made no comment on the
landing; indeed, several days later, when questioned about the flight, she could remember
nothing that might have damaged the
undercarriage, and was 'flabbergasted to think
that any damage might have been done on that
particular flight'.
However, to return to the flight in question,
immediately following the landing an
undercarriage problem occurred in that the gear
'in transit' light remained illuminated. As the
micro-switches were a known problem, this was
not a cause of immediate concern. Then the
load meter showed that the electro-hydraulic
pump was not operating continuously, and
recycling the gear plus a further landing did
not resolve the problem. The trip was cut short
and a 'normal' final landing made.
The problem with the 'in transit' light was
reported to the owner on the following morning,
and that afternoon the aircraft was positioned
in preparation for a travel flight, which was
completed the next day. The pilot apparently
found no damage on either pre-flight inspection,
and on arrival at his destination approached a
LAME to fix the 'in transit' problem; this was
immediately diagnosed as being the result of
damage to the left u/ c assembly. The LAME
considered it so severe th at the wing could
h ave collapsed under stresses imposed by
merely taxiing t he aircraft. Both top and bottom wing skins were fractured and considerable
internal damage was found.
The damage was reported to the owner [and
written up? - ed], who contacted the several
pilots who h ad recently flown the a ircraft.
No-one (including me) admitted a heavy landing. In my case, I was backed up by the
instructor with whom I flew the night circuits.
On reflection, though, it is likely that the major
damage was caused by my landing, which I still
believe to have been within normal limits. My
hypothesis is that there may be either a structural or design weakness in certain types of
light aircraft that allows a progressive failure
to occur in the area of the u/c attach point in
the wing. The occurrence which finally causes
the damage may not be of the magnitude
required to a lert the occupants to the fact t hat
t he damage had occurred. I feel that it is likely
that t he u / c failure, apparently resulting from
my 'heavy' landing was the result of a progressive failure over a period of time and needs
to be a ddressed by periodic maintenance. I
believe that during repair it was noticed that
several rivets in key areas had failed at some
point prior to the main failure.
I asked a colleague, who heads the structures
cell in Airworthiness Branch, to comment here.
He assured me that a search of Major Defects
Reports revealed no evidence of progressive
failure of the PA28R landing gear, or indeed,
that it does not meet design requirements.
When defects are found, they are attributable to
defective maintenance or actual abuse. Perhaps
pilots of light aircraft expect too much of the
undercarriage?
What an aircraft designer can and does do is to
build in systems, warnings and check requirements that are intended to bring to light incipient or actual problems. But, just as any beast
of burden, an aircraft will show unequivocally
that it is being overstressed or maltreated BUT ONLY TO THOSE WHO LOOK WITH DILIGENCE. As to the heavy landing(s), with a consequential dismissal of ominous signs and/or
non-recognition of actual damage, well, a
warning is a warning is a warning - and if
you get three before you become part of a smoking heap you 're luckier than you deserve to
be... D
,
>)
NOTAM C4 I 1990
refers to a fax trial within Sydney and Brisbane F!Rs to
offer pictorial information on Military Low Jet Route (LJR)
operations. Low flyers are strongly encouraged to phone details to
008 I 028238 (RAAF Amberley QLD) or 008 I 077243 (RAAF Williamtown,
NSW) to allow F 78 and F17 7crews to plan accordingly. PLEASE advise your
local RAPAC of the effectiveness of the trial.
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••
�Aviation Safety Digest
Aviation Safety Digest
147
147
Search and
Rescue
Alerting
Jim Hanigan, National SAR School
VER THE HISTORY of aviation, methods
of alerting the Search and Rescue (SAR)
system have been developed according to
the technology available. Initially, people only
reacted to the non-arrival of a particular flight
when there had been some form of pre-take off
warning. As the 'electronics' industry grew,
pilots became able to advise ground operators
of in-flight emergencies and diversions .
By the early 1970s, both electronic and battery
technology had advanced to the stage where a
low-power transmitter carried in an aircraft
was capable of being automatically activated in
the event of an crash. Thus the Electronic
Locator Beacon (ELB) became a part of the
safety-conscious aviator's essential items of
equipment. The system not only aids the aviator in distress but also the mariner, who uses
a similar beacon called an Electronic Position
Indicating Radio Beacon (EPIRB).
In the earlier years of the ELB, success of the
alerting function of this equipment relied on the
monitoring capability of aircraft flying through
the area. Nowadays, though, the big eyes in the
sky forming COSPAS/SARSAT are becoming
increasingly efficient in receiving and reporting
(with position information) emergency
transmissions.
An International cooperation program involving
Canada, France, Gr~at Britain, Norway, the
Soviet Union and the United States of America
developed the COSPAS/SARSAT system.
COSPAS is an acronym in Russian meaning
Space Project for Searching for Vessels and Aircraft in Distress, while SARSAT stands for
Search and Rescue Satellite Aided Tracking System. The system does not have its own dedicated satellites but operates from packages
carried by other agencies, such as the weather
satellites operated by NOAA, in near polar orbits.
The system can operate by detection of the signal radiating from existing ELBs and EPIRBs on
121.5 MHz. As the satellite passes the position
of the beacon, an apparent shift in frequency
0
(Doppler Shift) is detected and analysed by
ground-based software. This analysis will provide a latitude and longitude readout of the
beacon location. On the initial pass, an ambiguity will result because of a second possible
location of the beacon, the mirror image on the
other side of the satellite's track. Second or
subsequent satellite passes will resolve the
ambiguity and isolate the transmitter. A typical
error in position for a current generation ELB is
of the order of 20 km radius.
Reliability of Beacons
Currently, the ELB is the weakest link in the
SAR alerting system. Certainly a beacon could
be designed to withstand the extreme forces
applied during an aircraft crash, including the
possible post-impact fire. However, the cost of
this equipment would be extremely high. Statistics available from Canada and the USA indicate that current generation beacons have
failed to activate on two out of every three
accidents. A Canadian analysis of 155 accidents
over a five year period has classified some of
the reasons for failure as follows:
• 30% - human, not armed or not carried
(although carriage was indicated on flight
plan or flight was in an area where carriage
was required).
• 17% - environmental (ie antenna under
water).
• 50% - malfunction due to crash.
Added to the above poor reliability is the high
number of false alarms generated by current
ELBs. No attempt has been made to extract
data for the Australian scene (although this
will be done eventually) but again using overseas statistics, a false alarm rate of the order of
97% is indicated. Such poor statistics do not
encourage the aviator to invest his hard-earned
dollar in a piece of equipment that has a low
chance of performing when required, yet a high
probability of embarrassment due to inadvertent activation.
Similar statistics can be expected for the Australian area and will be presented when available. The disturbing factor in the analysis is the
number of pilots who are prepared, whether
knowing its shortcomings or not, to fly without
the safety device fitted or with the device fitted but not armed, possibly in the belief that 'It
can't happen to me'!
I
One of the greatest limitations of COSPAS/
SARSAT operation with 121.5/243 MHz beacons
is the requirement for the satellite to be visible
simultaneously to both the beacon and the
ground station, as this part of the system operates in a relay mode. The area thus covered,
however, handsomely contains Australia's domestic airspace. A second major limitation is that
the system can become saturated when too
many beacons transmit simultaneously.
A new generation beacon has been designed to
operate with COSPAS/SARSAT on 406 MHz.
Rather than transmitting the distinctive warbling tone of older 121.5/243 MHz units, this
new beacon will emit short coded bursts every
50 seconds. Several benefits will result,
including:
• Coding will provide specific beacon (and
therefore craft) identification.
• Improved area coverage: these signals can be
stored on board the satellite when no ground
station is visible, then downloaded when the
next station comes into view.
• Greater accuracy in position, typically of the
order of 3 km, because of closer tolerances in
beacon specifications.
Australia has an earth terminal called a Local
User Terminal (LUT) to receive COSPAS/
SARSAT information. The terminal is located at
Alice Springs, with the Mission Control Centre
at the Marine Rescue Coordination Centre Australia (formerly Federal Sea Safety Centre) in
Canberra. This centralised location can view the
satellites anywhere within the Australian continent and, as they 'rise' and until they 'set', for
some distance offshore. However, information
from up to double that distance is attainable, as
each satellite has its own horizon and thus can
receive then relay emergency transmissions
from as far east as New Zealand or New Guinea
in the north.
A number of measures can be taken to reduce
the incidence and/ or duration of false alarms.
• 'Start up' and 'shut down' procedures in AIP
and VFG include a suggested technique for
pilot monitoring of 121.5 and the reporting
procedures that should be followed if an inadvertent activation is discovered.
• Pilots should know when ELB equipment is
fitted to the aircraft being flown; if a 'hard
landing' is experienced, check 121.5 MHz to
see if the beacon has been activated - if it is
transmitting, switch it off immediately and
inform your nearest Air Traffic Services Unit.
• Include a physical check of the ELB during
your pre-flight checks if possible. This could
also include a regular periodic check of operation on the 'Test' function in the prescribed
manner.
• Remove batteries from a portable ELB when it
is not intended for use for some time (say one
week or more).
SUMMARY
Some of the statistics shown above do not convey a favourable impression of the ELB as an
alerting device. However, this equipment is
essentially first generation and the technology
is advancing rapidly.
Remember that these small emergency transmitters can save the lives of those unfortunate
enough to be involved in an aircraft accident.
Australia has its own LUT for COSPAS/
SARSAT . This will provide the location of an
ELB within 3 hours of activation, significantly
reduce search time and, as a direct consequence, increase prospects of survival.
In the centre section of this edition is a small
questionnaire that we ask your indulgence in
completing and returning to the address shown D
COSPAS/SARSAT coverage for 121.5/243 MHz EPIRBs;
·t
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r
m~e~d~
i aTn~ti~m~eTt~
o~d~
e~
t erc~ta~n~d~l=
oc=a=te~.=::::::::::1~-----i~~r---, 4 s
24
As the new beacon uses pulse transmissions,
direction finding systems on search aircraft will
not be effective. Consequently, a second transmitter operating on 121.5 will have to be
included with the package to enable final
homing on to the target. However, this secondary beacon can be of a lower power than present ELBs, giving an extended battery life and
reducing the saturation level of
COSPAS/SARSAT.
55
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9_
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0 _ _1i20_ __1 s~o-~1~4~
0 --1~so=---~
1 6~0-~1~77
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aoE
�Aviation Safety Digest
If you are not eligible for a free issue, or if you would like additional copies of the Digest:-
147
A little learning
is a (very)
dangerous thing
Pilot contribution by R A Perkins
I
AM WRITING to you regarding the recent
fatal accident in Sydney involving a student
pilot during solo flight training.
It appears from the pictures on TV that the aircraft impacted the ground nose-down at high
speed with partial flap extension, and it was
reported that the student was practising stalls.
It appeared that the aircraft was not recovered
from a fully-induced stall and was possibly in a
spin.
When I was doing solo flight training I always
dreaded stalls, as all the time in the back of my
mind was the question can I recover from a
spin should it ever occur?
Sure, we were always shown how to recover
from a stall, and if an error was made with the
instructor present the necessary corrections
were made before anything dramatic developed.
Looking back through my training syllabus,
spins and spirals were only covered as the second last exercise. On reflection, I believe it
would have been more useful to have covered
spin recovery much earlier - as early, in fact,
as the introduction to stalls before circuit training. I believe that a student pilot should experience recovery to level flight from every
possible attitude of the aircraft, in order to
become accustomed to the aircraft's handling
and to gain confidence in one's own ability to
react instinctively should the need arise.
To this day I still approach stalls with less than
100% confidence, so I think it's time for me to
do more than a bit of soul-searching - thinking
that the accident could have been me and doing
something about it:
(a) writing to you to start a discussion on the
subject;
(b) suggesting that flight instruction centres
put more effort into teaching spin recoveryeveryone can fly straight and level; and
(c) enrolling myself for a course of aerobatics
to gain confidence in handling the aircraft
in all attitudes.
As a footnote, I should like to record my thanks
to my RPPL examiner for putting me through a
few different manoeuvres and recoveries that
previously I had not experienced.
We admire the courage of this correspondent
for freely admitting his lack of confidence in
his ability to recover the aircraft he is flying
from any unusual attitude. His problem is
reasonably common and is a shocking indictment of some so-called professional flying
instructors.
We feel so strongly about the predicament this
pilot finds himself in that an entire edition of
this magazine could be devoted to answering
his concerns and those of many others like him.
These problems stem from flying training often
being little better than the blind leading the
blind. For a variety of reasons the flight
instructor profession is unique in that the bulk
of the teaching appears to be given by those
who are themselves very much at the bottom of
the learning curve. Hence we have people
paling around the sky who, just as the pilot in
question, are unsure of their ability to control
the aircraft in other than normal
circumstances.
We believe this situation is so serious that, as
requested, we will initiate thought and discussion on the topic of unusual attitude
recoveries in general. The refore, in place of our
normal quiz, we sincerely solicit your considered response to the questions in the centre
section. An analysis of the results will be published in a near-future Digest 0
(),
Four
iSSW8S
$A 14.00
· · . . ·' :.;,.,,:. -·. - . ·i1 .,;1;,;..;-~-;;L-i ; -- .•. ,~~-~
AVIATION SAFETY DIGEST reports incidents, recounts
stories, relays technical information, represents the pilot
and others involved in aviation, and, to the extent that it
falls short of being a legal document, reflects the viewpoint of the CAA.
We have noted previously that regulation alone may well
have been exhausted as a means of reducing accidents.
This is not to say the CAA is on autopilot - there are
moves afoot to make CARs, CAOs and subsidiary legislation more user-friendly (or at least, somewhat simpler).
Although an aviator will always benefit from reading about
another's brush with disaster, we are all fortified in the diligence of our personal pursuit of safety by the knowledge
that there are a lot of fellow flyers who think twice - nay
three times even - before committing themselves (and
their passengers - never forget the pax) to operations in
(inc1udingsur1acepostage;
,
.
.
marginal conditions. Self-discipline, mechanical reliability
and the correct application of hard-gained expertise are
but the three leading links in the chain of circumstances
that define a tru ly successful flight.
The wide range of submissions that cross the editor's
desk are testimony that 'marginal conditions ' cover practically everything. There are a million articles out there in
the real world, and a zillion incidents (99% of which you
wouldn't dream of putting your name to - that' s OK,
we 'll respect your desire for anonymity). So why not share
your hard-earned lessons? As I said , your story is unique!
To be part of this accumulated wisdom, those with an
interest in flying , be it as a professional or paid-for-byyourself, will do themselves a favour by reading the Digest
on a regular basis; if you do not obtain a free copy, the
subscription form is, as they say, overleaf.
-------------~----------------------------~-- ·
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to: AIRFLOW
Aviation Safety Digest
G.P.O. Box 367
CANBERRA A.C.T. 2601
Australia
Aviation Safety Digest 147 / i
�0
Entry Form for the Aviation Safety
Digest Photographic Competition
Dear Sir,
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details are as follows:
Category of Entry:
Film Size and Type: - - - - --
Camera Type:
Caption or Title:
----
I
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I
I
I
I
I
I
I
issues 1-146
Index of articles
Accident & incident
investigation
)
Toxic pesticides 34-28
Wire strikes 3-26 7-23 8-25 8-27 9-21 9·25 12-4 12-21 12·22 13-24
15-27 20-19 21-18 28-22 31-28 36-1 36·18 56-16 59-16 63.17 64-22
67-167-367-5 68-10 70·7 70-26 80·28 88-16 102-8 108-19 114-4
120-11 120·12 123-21 135-12 140-7 142-5 146-7
See also Special Ag. Issue 1985
Description of the Photograph and Theme (please identify any aircraft type):
Ancient accidents 138-23 145-9 146-12- and flight testing 138-30
Aircraft systems
BASI (history) 138-10
Costs of aircraft accidents 121-18
Name of Entrant:
Could it happen to me? 142-10
Address:
Engine failure 135-19 136-8 137-19
Helicopter accident review 129·8
Phone and/or Fax no.
How to make the game tough 130-20
I agree to be bound by the conditions of entry as described in the advertisement
Signature:
Canberra ACT 2601
immunity 24-1 54-1 100-1 114-3 122-12
the Australian system 109-14
Date:
TO: Photographic Competition
Aviation Safety Digest
Civil Aviation Authority
GPOBox367
Incident reporting 27-10 32-15 109-16 113· 13
--
Involving private pilots 129-4
Kilmore gap 133-4
ENTRIES CLOSE: Last Mail
Friday, 4 April 1991
Results will be published in the
Spring edition of the Digest
controls 36-12
monitoring gauges 107-12
Low cloud base, rising terrain 129-20
Fuel
Release of information 117-3
Statistics 87-12 110-30 115-18
Takeoff 103·6
Theory of prevention 102-10 128·3
Entry Form for the Aviation Safety
Digest Photographic Competition
Engine
Flight recorder 110-9
Predictability of causes 138-34
{~
123-17 127-10 132-14
Licence suspension 37-22
Mid-Airl 142-6 142·8
-~---------------------------------------------L--
Electrical 12-1 32-18 46-14 75-8 98-12 98-26 105-18 105·19 105-20
Undercarriage 137-4
auxiliary fuel pumps 121·8
Cessna 200 fuel system malfunctions 114-20
leakage 38·5 79-16
mixture control technique 55-13 87-22 106·4 126-13
spark plug fouling 113-22 127-22
specific gravity 112-28
systems 57-8 119-23 120-12
tank caps 27-4 37-14 109-18
tank vents 35-10 59·4 89-24 113-10
vapour lock 43·6 121 -8
Gust locks 100-4
Hydraulic 127-10
failure 14-24 32·6
fluid contamination 17-5
Aerobatics
Dear Sir,
Landing gear 59-19 111 -14 115-10
Oil
exhaustion 104-28
filter 32-19
on windscreen 45·5
shortage 44-9 46·26
system 56-24
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details are as follows:
Category of Entry:
Film Size and Type: _ _ __ _ _ _ _ _ __ _
Camera Type:
Caption or Title:
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Propeller 6-12 18·10 43-16
Description of the Photograph and Theme (please identify any aircraft type):
Undercarriage indicator lights 59-15 102-18
8·23 9·22 10-17 27-3 27-27 28-12 33.9 34-19 40·4 47.5 75-12 76-12
78·6 81 -10 87·6 92·2 102-19 104-26 117-6
Warning systems 119· 15
Name of Entrant:
Address:
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Signature:
TO: Photographic Competition
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Civil Aviation Authority
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Canberra ACT 2601
Date:
ENTRIES CLOSE: Last Mail
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Results will be published in the
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II
Airports and aerodromes
Agriculture
I
6-7 6-22 7-22 7-27 8-5 9.7 9-23 9-24 10·17 10-19 11-26 12-19 13-26
16-27 18-118-7 20-17 27-10 20-18 20-25 21 -27 24·8 28-14 28-24
30-7 30·8 30-16 31-26 31-27 33-23 38-1 41 -14 42-12 44-14 44-19
48·450-14 56-2659-25 62-1970-1974-1080-2190-692-2794-26146-7
ag. strips 13-25 13-27 58-10 86·19 98-2 98-9 104-18
Aerodromes
Authorised landing areas 58-17 64-14 67·1 67-10 97-22 135-5
145-13
Government, licensed, ALA 107·5
licensed 41-24
outback 5-6 53-20 58· 17 103·29
procedures 49-13
Aviation Safety Digest 147 / v
�Aircraft security
general 102-16
theft of fuel 59-21 98-27 114-22
Animals 70-24 101 -24 103-27 106-21 130-23
Anti-collision lights 105-25
Birds
ground attack on aircraft fabric 53-28
nests in aircraft 83-21 99-28 107-26 112-12 118-14
strikes 2·9 34-24 38-6 41·11 49-5 71-1 87-27 102-28
104-12 109-13 120-18 128-16
strike reporting 112-30 128-19
Fire
brake and wheel 71-27 45-18
engine 9-18 18-4 24-24 33-6 39-23 45-2 64-16 83-13 115-14
undershoots 3-15 5-17 12-17 21-13 26-16 43-12 61 -24 64-1 76-2
78-14 80-26 93-20 93-24
unsuitable landing areas 42-20 47-26 50-2 55-14 58-6 58-18
58-20 61 -20 65-20 67-19 70-1 70-11 78-18 93-12 96-21 100-24
103-29 115-3 123-14
wheels-up landings 1-10 6-26 14-4 14-25 29-12 39-27 50-27
51-21 62-10 66-12 68-18 83-18 92-12 92-18 98-28 110-16 113-12
116-21 117-21
hand portable fire extinguishers 124-3
in flight 7-5 9-18 33-14 64-16 146-20
refuelling 1-7 18-31 42-24 45·14 55-9 63-13 104-30
spootaneous combustion 119-12
Lookout 136-15
Fumes in cockpit 61 -22 77-1
lnflight vibration 119-10
Chocks 105-9
Mercy flights 5-19 8-17 17-13 25-27
Stall 2-24 3-29 5-18 5-21 5-25 6-24 7-25 8-23 9-22 11 -23 14-21
Ground safety 24-3
Monitoring 121 .5 127-23
Insects
extermination hazards 83-27
hazards 43-27
nests 16-26 49-22 55-21 89-24 118-11
Power lines 144-20
19-20 20-1 21-12 30-3 34-14 34-19 37-10 44-10 45-12 47-2 48-10
56-8 84-26 88-9 92-2 92-7 92-20 93-6 93-10 94-22 97-6 99-24
101 -18 121-6
Runways
condition 5-21 6-21 8-7 9-9 20-24 23-21 85-10 89-13
foreign objects on 41 -22 45-25 50-7
lighting, VHF activated 103-19
visibility 3-7
Procedures 2-18 8-14 28-13 36-20 36-23 41 -12 56-12 57-14 98-12
Vne 122-13
Wake turbulence 104-11 121-3
Human factors -
Propeller 13·1 128-16
Taxiing 53-20 58-5
Sarwatch 39-8 50-13
Trim 15-5 32-22 46-148-1070-14 118-8
Search and rescue 25-21 25-28 36-3 77-1 86-21 91 -20 101-28
Special 1987
102-24 103-22 104-27 105-28 125-16
airborne direction finding 125-17
Aircraft Instruments 129-18
Airsickness 90-13
Structural damage 116-12
Gliding
Survival 18-1 46-21 50-26 77-6 116-15 117-20 139-21
Undercarriage 137 -4
T-vasis 41 -5 114-13
Weather 137-15 138-27
physiology
Takeoff 1-13 1-24 2-15 5-7 18-26 20-16 53-18 61 -12 71 -1 85-10
88-9 90-10 90-16 91-1192-20101-18 104-6 104-16105-7
123-16
Taxiing 1-22 3-24 58-5
Alcohol 52-2 52-6 63-1 77-20 85-2 127-18
Caffeine 116-19
Carbon monoxide 23-26 45-16 51 -13 89-18 109-3 113-23 126-11
Dehydration 110-3
Tie-down 110·6 112-18 146-10
Diet 103-25
Wake turbulence 2·16 21-6 25-7 31-20 51 -14 54-25 63-14 65-16
87-20 94-28 95-10 121-3
Windsocks 135-20
Tail rotor failure 69-8 86-16
Weight and balance 25-17
Spin 1-22 3-20 5-23 10-22 10-23 14-21 16-28 19-18 26-10 104-20
Chipmunk 22-1
65-12 80-11 98-16
Slung loads 122-6 130-16
Loss of rudder control 17-19 23-7 54-14
Life jackets 92-25
Jet
blast and intake danger 15-2 19-29 26-13 50-8 60-20
Safety 82-16
Disorientation 140-16
Flying techniques
9-20 15-28 19·10 19-11 21-2622-22 27-22 33-22 42-15 54-11 61-1
62·2 84-2 84-6 84-10 84-14 84-21 84-26 90-2 101-4 101-1 7 101-19
107-18 107-19 118-10 124-12 125-13 127-9 135-16 143-4 144-20
,.
Special edition 1986
Drugs and medication 8-6 48-27 58-16 63-9 63-19 85-8 90-13
132-23 142-16
Ergonomics 1-5 102-18 117-16
Fatigue 8-2 12-10 12-22 17-22 19-6 20-18 26·6 72-10 86-27 95-19
123-12 125-5
Emergencies
Food poisoning 40-22 51-11 104-10
i-iiili
Airmanship 139-14 133-6 134-20 144-8
Airspeed 26-20
limitations in turbulence 21 -1 43-20 116-24
manoeuvring speed 27-3 31 -1 107-16
Va and aircraft weight 118-7
Aquaplaning 142-20
Asymmetric flight 1-11 4-1 6-17 7-10 8-1~ 12-14 13·11 16-20 17-7
19-8 19-26 20-26 21-24 23-10 26·6 27-6 31-8 36-1 6 41 -12 44-2 51-6
63-5 78-11 90-20 93-2 105-10 108-3 109-9 123· 10 125-8 126-6
Decompression 35-16 37-19
Ditching 5-10 5-19 7·6 10-12 16-20 29-23 33-6 36-4 60-16 80-16
92-25 139-8
Door open in flight 32·10 63-2176-1987-8 100-28 115-7 118-22
123-22
Emergency landings 3-25 6-25 7-5 7-10 8-21 8-22 8-26 10-21
11-25 11 -26 12-18 14-17 17-26 18-23 21-22 22-8 23-18 23-25 24-1
30-18 34-8 36-20 36-24 37-24 39-27 42-13 43.4 44-2 45-12 49-6
50-22 50-26 52-10 54-23 55-13 57-8 58-13 59-1 59-21 59-22 65-28
66-4 67-7 70-1 70-16 71-17 71 -22 74-14 76-22 77-1 78-11 78-18
78-24 82-24 82·26 85-9 86-2 86-19 87-2 88-12 89-14 92-7 92-1 1
92-14 99-10 99-27 103-20 107-20
Emergency locator beacons 91 -20 116-17 125-19
Engine failure 1·23 2-18 6-22 7-6 7-10 8-14 10-20 10-21 11 -23
11 -25 12-12 12-14 13-6 13-12 16-20 16-26 18-30 19-26 26-24 28-16
32-12 36-4 36-20 41 -12 44-2 45-12 46-6 51 -6 52-10 55-13 59·1 59.4
69-5 70-16 71 -22 74-14 76-22 76-23 80-28 89-14 91 -3 92-14 121-11
123-10 135-19 136-8 137-19 141-16
Evacuation 26-14 108-23
Aquaplaning 29-16 37-16 39-1 53-14
G-loc 138-4
Helicopter
Circuit entry 97-14 99-8 108-25 127-3 127-4
Accidents 1974-83 129-8
Engine handling 136-8 139-16 141 -14 141-15
Compressor washing 130-18
Fuel management 1-23 3-17 5-10 6-25 7-6 8-21 8-22 21 -12 36-24
37.9 37-24 39-27 40-24 42-26 43.4 46-18 50-14 50-26 55·2 57-17
59-21 59-22 67-7 71-17 81-24 86-2 87-2 87-26 91 -22 93-16 103-20
103-21 109-16 112-14 112-23 115-4 124-13 126-13 127-6 127-22
138-14 138-26 144-8 144-19
Landing
checks 99-13 119·9
engine failure 135-19
expectancy 107-10
flap retraction 76-14 111-23
ground effect 9-3 111 -3
ground loops 29-26 63-24 65-6 74-24 79-27 96-10
heavy landings 12-17 14-15 23-4 25-24 47-21 60-16 63-22 64-26
,
89-20 122-10
non-precision instrument approach 108-26
overrun 9-9 17-9 30-4 101-2
soft-field operations 116·18 118-15
tailwheel aircraft and crosswind landings 122-3
technique 6-3 10-3 14-5 21-5 23-21 25-8 27-6 28-26 29-16 64-1
79-22 95-19 97-10 99.5 104-22 111 -23 117-5 134-8 134-13
to 134-19 136-4 136-17
transition from instrument to visual approach 126-9
High altitude flight 3-3
Hypothermia 123-8
Oxygen
antidote to cockpit fumes 52-21 61-22
hypoxia 66-7 101 -23 105-3
oxygen systems 18-6 41-21 112-1 145-20
Pilot incapacitation 29-1 51 -1 100-26 104-20
Engine overspeeding 60-10
Protective clothing 130-17 132-21 143-10
General 47-10
Scuba diving, flight after 28·7 43-11
Grass fires 48-17 50-21 113-7 126-17
Sensory illusions 2-53-9 7-816-1 20-21 35-637-2575-2 75-18 96-14
Ground resonance 125-20
Skill fatigue 121-20
Hughes 500 fuel tank vent fairing 111-20
Ice 30-10
Loss of directional control 128-4
Maintenance 109-22
Mast-bumping 115-20
Performance 141 -18
Power-settling 68-20
vi /Aviation Safety Digest 147
Heat stress 122-20 135-10
Dynamic rollover 126-18
Overpitching 51 -9
II
Hearing conservation 118-12
headsets and warning horns 122-7
turbine aircraft 37-20
Rollover 91 -25
Toxic fumes 130-22
Vision
blind spot 106-3
dusk 70-19
eye protection 101-11
night vision 108-24
photochromic lenses 95-29
polarised glass 109-23
sunglare 6-25 9-23 17·21 58-27 59-25 98-8 107-3
wirestrikes 123-21
eyesight 133-22 136-9
Visual illusions 37-25 48-18 67-24 78-1 78-14 93-20 103-8 110-24
111-10
Aviation Safety Digest 147 / vii
..
�Human factors - physchology
•
.
•
Navigation 5·19 12-15 18-1 6 19-12 21-10 26·6 26-19 27·11 31-13
32-16 35-1 39-18 41-6 44-20 47-26 55·2 55-10 55-16 66-4 70-1 72-1
72-18 72-21 72-28 78-18 85·6 93-12 97-16 98·2 99-18 102·5 102-13
110-28 113-20 143-17
lanes of entry 113-4 116-23
Engines
compressor washing 130-18
control maintenance 36-12 54-23
ground run fiasco 130-13
mounting failure 62-16
OCTA 141 -10
Fabric separation 30-23
Passengers 129-13
Flexible hose installations 56-24
Restricted areas, penetration of 111 ·27 117-12 124-20
Foreign objects 14-10 23-1127-1241-22 45-25 50·7 61 ·6 62-18
Area Forecasts 140-12
Assessing the situation 130-12
Density altitude 33-1 110-18
Downslope winds 143·11
Dust devils 101-20 139·4
Dust stonns 122-6
68-24 76-21 92-28 104-25
Fog 40-20 41-2 61-24 76-2 100-20 107-28
Alnnanship 48-14 67-14 78-28 79-14 102-4 116·5 117-13 127-8
Fuel tank caps 27-4
Forecasts, interpretation 106-26 109-24 119-21 126·7
130-4 145-14
Glued structures 32-20 35-18
Frontal weather 142-7
Channelised attention 103-28 107- 19
Ground handling procedures 126-22
Frost 62-20 102-27 106-10
Harness 144-9
Hail 31-18 49-10
Heat treatment 145-16
History of 138-12
Heavy landings 47-20 60-16 63·22 122-10
Ice 25-4
airframe 14-1 19-20 23-18 25·3 40-6 57-16 61-25 62-20 85-24
Special 1987
Weather 133-4 137-15 138-27 141-8 143-20 145-10
Crew
crewmanship 5-3
division of responsibility 28-26 30-18 95-19 110-28
114-17 119-19 123-9
flight deck management 63-5 103-8 109-8 110-24 115-16
liquids in the cockpit 6-5 27-25
Decision-making 31-22 116-1 1 124-17 146-8
frustration 110-29 124-16
IFRNFR compromise 7-15 9-14 10-16 17-18 18-20 18-28 20-10
23-12 30-1131-2437-141-842-18 49-16 54-7 73-13 73-24 74-1
77-17 78-21 79-18 80-2 81-2 81-6 82-10 82-19 85-9 89-2 94-2
95-295-696-14100-20100-23100-30105-26 106-7109-26 11 1·4
113·8 114-23 120-16 121-13 122·9 126-20
programmed mind 5·24 6·27 7-26 10-22 12-15 14-23 16-14 16-16
16-18 16-25 17-13 18-20 37-1 39-4 40-20 41-16 49-1 52-14 55·2
57-18 57-27 60·1 65·1 68-1 73-2 73-8 73.17 75-2 77-10 79-2
82·10 82-19 87-16 91-6 91- 16 99-14 102-2 102-9 103·3 103-25
104-18 105-15 112-23 119-16 122-9 127·13
recognition of personal limitations 109-30 116·4
Distraction 77-28 83-13 83-18 88-2 94-6
Exceeding authorisation limits 3-29 5-23 5-25 6-16 6-24 6-25
8-23 8-26 9-22 9-26 11-22 12-4 13-25 14-26 15-28 15-30 16-25
16-26 25-14 28·1 35-22 36-1 36-8 43·8 47-5 47-7 56-18 60-4 66-1
68-10 74-8 74-24 77-20 78·6 79-6 79-10 81-6 81-28 83-2 84-16 96-4
97-2 115-17 126·3
Stress 115·6 119-17 120-14 129·6 130-14
Supervision and self-discipline 121-12
I
Instruments and navaids
Complacency 94-6 123-18
'
•
Hydraulic fluid contamination 17·5
Hydraulic pressure failure 14-24
Ignition switch, misaligned 53-26
Inadvertent undercarriage retraction 23-23 101 -10
Altimeter 7-3 14-18 19-4 27-14 45-24 48-18 65-14 65-23 74-28 78-1
80-22 87 ·6 87-28 94·6
Landing gear 33-15 39-7 49-18 60·22 69-12 112-13
Autopilot 21-14 70-14 90-26 118-13 144-10
Loose objects 130-21
Compass
error 31 -22 44-20 72-21
interference 22-20 27-26 28-23 55-20 69-22 97-28
Maintenance error 5-11 15-24 17-19 17-26 18-19 22·8 22-16 23-14
26-24 28·6 33-16 33-24 34-10 36-11 38-26 42-11 46-26 47-22 48·7
70-22 92-27 100·15 120·21
Deficiencies 28-1 1 31-6 34-20 53-13 64-27 98-24 118-13
Maintenance release 115-8 137-6
DME 143-12
Metal fatigue 2-20 15-7 57-10
Pltot
blockage 66-9 75-23
covers 49-14 52-16
Summer 139-13
Navaids 33-27 87-26 109-21 146·4
Permissible unserviceabilities schedule (PUS) 3 1-16
Temperature and humidity: effects on wing lift and engine
power 11-7
Radar 24-6 40-5
Propellers 1-22 2-14 6-12 9·11 15-24 17-9 18-10 26·9 33-20 35-26
102-18 103-28 104-17
Monitoring instruments 24-13 54-18 127-6
Airworthiness 140-9
Bogus aircraft parts 17-1 141·21
Controlled airspace 28-3 31-13 34-1 46-4 69-22
penetrations 19-12 28·3 46-4 69-22
Brakes 11-27 45-18 71-27 91-28
excessive wear on dirt strips 111-9
failure 85·10 88-14
reverse thrust 31-7
Flight Service 8-7 85·6 101-22
Cessna 310 fuel selector 128-14
Low jet routes 101-5 136-14 143-18
viii/ Aviation Safety Digest 147
-
\
.
~
Control cables
crossed 6-8 8-21 20·5 59-27 107-30
inspections 29-24 107-15
rudder controls 17-19 23-17 54- 14
splices 101-13
123-3
Spring 134-5 142-5
69-1 72-24 117-22 132-16
fatigue failure 27-1 99-21
shock loading 67-22
Air pollution 122-11
74-18 75-28 77-26 98-5 10 1-8 103-27 119-3
near miss 74-18 75-28 77-28 108-25 115-13
Satellites 137-1O
Solitary waves and low altitude wind shear in Australia 99·2
Interference with controls 54-2 58-13 69-16 89-13 99-27 100-4
Maintenance and servicing
Loss of separation 19-3 35-1 6 1·10 94-28 102-14
collision 5-16 7-24 7-27 11-13 20-6 25-20 27-18 28-4 33-10 62-6
Mountain wave effect 3-22 5-22 21-25 30-17 42-6 57-10 57-22
88-27 94-14 137-12 137-13
Oleo leg 47-16
lnflight operations
GAAP Quiz 140·21
Microbursts 130·6 144·4
Instrument procedure design 143-12
Recording procedures 33-16 65-26
47-28 49-13 52-13 57-14 68-22
loss of 22-7 45-13 46-28 103-30 109-18 130-9 140.14 143-12
Meteors 46-8
Modifications 32-22 62-19 126·10
Strobe lights and ELBs 115-7
Communications 19-3 19-15 32-1 35·8 38-28 40-26 42-28 47-19
Lightning 39-10 40-12 62-22 66-24 146-18
ILS 9-6 22-10 139·9
Radio compass ?3· 1
Air Traffic Control 8-7 20-14 27-18 34-1 57-14 77-17 85·6 146-22
92-23 137-8
carburettor 25-18 35-21 45-20 50-22 55-20 59-25 61-26 85-18
103-31 106-28 108-14 112-24 121-16 145-4
engine 28-16
fuel 109-25
pitoUstatic 39-24 99-24
TAFS 141-5
Thunderstonns 11-3 31-14 52-22 59-10 60·6 68-5 82-2 82-22
94-10 104-3 108·8 113-21134-7 145·8 146-10
Tornadoes 54-26
Spark plug fouling 113-22 127-22
Turbulence
clear air 13-10 67-12 93-24
low level 109·10; downslope winds 143-11
Stop nuts 56-17 65-11
Weather radar 143-20
Structural
damage 49-16 54-21 65-1 2 76-12 77-17 88-24 90-28 failure 2-20
Wind
shear 6-9 14·13 30-12 3 1-14 34-12 98-20 103·8 133-18 106-14
5·25 9·20 11-16 14-15 15-28 21-1 21·6 23-4 24-4 25-24 27-3
28-12 31-1 33-22 34-24 35-18 43-20 46-12 51-20 57-10 59-10
68-5 81-10 82-2 83-13 86-8 90·2 94-2 107·16
limits 30-3 38-1 46-12 76-12 90-2
loose parts 46-11 59-20 78-11 138-15
]
Throttle-control failure 56-17 105-16 112-9
]
Turbo-charger failure 103-30
Tyres 23-17 49-21 118-23
106-22 110-24 133-18
speed, assessment 118-20
Winter 137-17
See also Decision-making in Human factors -
psychology
Mustering
Welded pipe lines 33.5
Wooden structures 19-1
lJ
Meteorology
93-6 93-1 0 101-25 117-18 118-3 123-13 129-23
Corrosion 86·8 109-20
Defect diagnosis 23-22
Aviation Safety Digest 147
/ ix
�Night VMC
Safety harness 26·1 34·11 36·27 99·9103·4 104·26 108-6111·8
114-22 119·7
Privacy or Paranoia?
Seats 62· 14 96-28 111 ·26 112·26 123·19
In ASD 146 was to be found a letter from Alan Heggen, Group General Manager, Safety Regulation. In
it Mr Heggen asked that pilots seek assistance whenever they found themselves in need, rather than battling on in self-imposed silence.
Weight and balance 5-18 7·26 8·24 10·9 14·26 18-23 19·24 31·12
135.5 56-182·686-12 103-14 104·8 116·3
Windscreen 3-31 45·26 57·16 74·21 97-29
72·172·1094-26102·13 114·1 5 120·8
The letter elicited lively response, typical being the
sentiments expressed by an up-and-coming pilot. His
letter follows, together with Mr Heggen' s reply. Airlines particularly, and employers ofpilots generally,
are asked to write to us and make their position in
this matter quite plain:
Special operations
Parachuting
Dear Sir,
Banner towing 39-17
48·156·1369·14 70-11 101-14 116-27 125·7
I have just received your open letter to all pilots
regarding the need for pilots to ask for in-flight assistance should they find themselves in difficult circumstances, and I appreciate the comments you
have made in that letter.
Beach operations 107·8
Outback 5·6 46-21 53·20 55·2 55· 10 55-supplement 58· 14 72·28
77·6 97·16 97-20 98-14
Preflight preparation
Papua New Guinea 3·22 7·26 21·20 43·1 45·1166·1671-10 100·7
100·13
However, there is a fear that exists amongst those of
us who are involved in obtaining CPL licences with
the intention of gaining employment with the major
airlines that ANY Form 225 [now renumbered CA
2593] with your name and licence number on it constitutes a 'black mark' against your file, regardless
of the incident, and that this data is readily accessible and utilised by airline recruiting sections to
determine an applicant's suitability.
Tiger Moth 3·20 81·14 83·17
Training
Aircraft familiarisation 29· 11 59· 15 62·28 70· 16
Cargo restraint 6-23 11·21 2308 80·6 101·7 113·13
This is not isolated 'crewroom chatter'. I have
spoken with pilots from many schools throughout
Australia and on the CPL subject courses I have attended, and the prevailing mentality is that any requests for assistance from ATC due flight difficulty,
or any other incident resulting in a 225 being filed,
can have long-term effects on your career. This is a
major reason why many pilots avoid reporting
problems.
Dangerous cargo 14·8 16·11 21 ·21 22·23 26-27 37·13 50· 19 52·21
66·10 89·28 101·26 115·23 120·3 126·4
Flight planning 3·25 12·18 18·28 19·6 21 ·10 22·15 28·8 28·20 42·5
49·13 55·14 55-supplement 59·8 69·27 70·1 78-18 82·6 88·22 89·8
97·2 99·10 102·2 105·8 109·19 111·28 120·16 125·3 143·12
24·20 56·5 76·26 128·10 133· 14
NAIPS 144-17
Students 64·26 65·8 91·3 91·8 106·3
Passenger briefing 110-29
Theory exams 136·6
If safety is at stake, there is a need to utilise every
available means of assistance, both within the cockpit and from external sources , but pilots who intend
to be career pilots will continue to weigh up the two
issues - on one hand 'I'm stressed out and in trouble
- I need assistance', and on the other 'Is it worth my
while to report I'm in trouble?'
Performance 11-7 33·1 37·4 42·150-1658·1 64·10 67-16 83·6
110-18 112·11117·10
P·charts 118-16 120·6 123·20
Preflight checks 26·26 28·21 34·6 38-24 42·14 42·19 42·26 46-26
60-14 65·28 66·9 66·12 69-25 86·17 93·16 96·196·2998·27 103·6
107·7 109·6 112-14 120·22 121·19 122·18 129·5 133·6 133·14
139·18 140·4 140·13
brakes 5·21 103·26
control locks 62· 14 68·27 90· 16 110·21
fuel 13·11 18·9 32·24 43-27 44.9 50·24 54·22 67·7 87·26 90·27
109-28 115·15 117-19120·12 125·18 128·15 133·16
contamination 12-19 14·17 24·18 26·22 30·16 35·14 45·8 45·27
46·6 64·9 64·28 65.7 74·14 91·3 108·13
Post flight checks 137·5
Propeller safety 35·20 40·3 40· 10 45·6 56-14 65·24 76-16 83· 11
89·23 91·14 96·23 96·26 103·12 124·18
Ultralights
For what it's worth, I hope this gives you a bit of an
idea of what's going through the minds of many
CPL candidates, especially as things become more
competitive and expensive, and airlines have niore
people to choose from. I would appreciate any comments you have on this issue.
23·25 11 9· 13 124·6 126·5
1
Yours faithfully.
Quiz 141·12 144·7 145·12 146·12
Craig Smith
Refuelling H 18·31 35·14 42·24 45·14 55·9 63-13
104·30 125·14 126·12
fuel conversion charts 125·12
x /Aviation Safety Digest 147
The Group General Manager
Replies
Dear Mr Smith,
I was very gratified to receive your letter of 2 October 1990 but was somewhat dismayed to read of
the apprehension that you say exists in the minds of
CPL candidates regarding the flow-on effect of a
call for assistance.I can understand tha~ such concerns might exist, and it would be naive of anyone to
deny the existence of the ' bush telegraph'. However,
I want to assure you and the entire aviation community that you are quite incorrect in your belief
that an individual's aviation history record is readily
accessible by airline recruiting sections, or indeed
by anyone outside the Bureau of Air Safety Investigation and the Civil Aviation Authority.
Protection of information relating to an individual's
aviation history is not simply a courtesy extended by
BASI and ourselves, it is a privilege conferred by
law. The Privacy Act 1988 makes provision for
protection of privacy of individuals and it places
very specific constraints upon 'record keepers'. In
brief, the Act prevents the 'record keeper' (in this
case BASI or the CAA) from using or disclosing personal information except with the consent of the individual concerned or when it is necessary, for instance, to prevent serious or imminent threat to the
life or health of persons, or for the purpose of enforcing the law.
The contents of an individual's aviation history file
are therefore most definitely not accessible to a
potential employer. CAA officers are not only extremely conscious of the law governing protection of
personal information, but they are responsible
people who respect the rights of the individual.
I suggest also that you misjudge the perceptiveness
of potential employers. I am certain that in most
cases applicants would be required to provide a
resume of their aviation history' including any involvement in incidents or accidents. I find it difficult to
believe that any .employer worth his salt would look
unfavourably upon pilots who had had the good
sense to call for assistance when finding themselves
in need of it. In fact, I expect that an airline would
derive a certain amount of satisfaction from knowing that its applicant was prepared to place the
safety of the aircraft and its contents above personal
(false) pride.
I trust this letter will serve to allay any concerns that
you and your associates may harbour. Nevertheless,
I would be interested to know whether I have judged
the employers' position correctly or otherwise and,
as I discussed with you, I will be seeking their comment through the Aviation Safety Digest
Yours sincerely,
Alan Heggen
Aviation Safety Digest 147 I xi
�CHANGES TO VFR OPERATIONS IN CONTROLLED AIRSPACE
In keeping with the CAA objective of more people benefiting from safe aviation, the way in
which Air Traffic Control apply separation to Visual Flight Rules aircraft operating up to
and including 10 OOOft is about to change.
What can they be doing /
s-
The effect of this change will be to speed the flow of these flights in controlled airspace.
~.
~
~
~.
Under present procedures, separation between VFR aircraft (below 5 700 kgs MTOW)
operating in Primary Control Zones may be achieved by requesting the pilot of one aircraft
to sight and follow another aircraft, provided the pilot acknowledges acceptance of this
responsibility and advises ATC how the separation will be achieved - a somewhat
cumbersome process, but one which·was developed having regard to legal precedent
regarding the functions of ATC.
~
~
~
Aircraft operating to Visual Flight Rules (VFR) in Control Areas in Australia are at present
provided with the same positive air traffic control separation service as aircraft operating to
Instrument Flight Rules.
rJJ
~
Regulation changes, which are expected to become effective in January 1991, will enable
ATC to allow the pilots of VFR aircraft to provide their own separation from other VFR
aircraft.
~
What are the implications for VFR pilots?
(IQ
As from the date the legislation is changed, in Primary Control Zones and their associated
Control Area steps, up to and including 10 OOOft, ATC may achieve separation by:
- instructing the pilot of one aircraft to "sight and follow"
another, or
- by providing traffic information on other VFR aircraft.
The traffic information will contain any of the following data as necessary to assist the pilot
in identifying the other aircraft:
-
type
callsign
altitude
position, either by o'clock reference, bearing and distance, relation to a geographical
point or reported position and estimate intentions
- direction of flight.
~-
::::1
To celebrate 1991 , we thought we might run a small competition.
Just this once, we've been let off the leash, so entries do not have to
be aviation safety orientated (although that is not to say that the
judges won't look kindly at entries that reflectASD's mission). The
(original) caption adjudged the funniest will earn its writer an
(original) Safety Promotion Unit plaque, eminently suitable for
hanging where one can sit and gaze at it in quiet and isolated
contemplation ...
Competition closes 31st March 1991, address as per the inside
cover; we'll publish the best printable entries in the Winter edition.
Others will be enjoyed in the privacy of the Digest Office.
The pilot's responsibility will be to operate according to the terms of his ATC Clearance
and maintain constant surveillance in order to provide safe separation. However, if a pilot,
having been given traffic on another aircraft, is unable to provide safe separation, e.g he is
unable to see the other aircraft or is not sure of the other aircraft's intentions, he will be able
to request ATC to provide the separation by use of the phrase, 'REQUEST SEPARATION
FROM ..... (callsign of the aircraft if necessary)'.
CAPTION:
Of course, if a controller observes aircraft to be in close proximity and on converging
courses, he will ascertain whether one pilot has the other in sight or will issue instructions to
one or both aircraft to resolve the conflict.
Address:-- - -- - - - -- - - - - - -- - - - - - -
xii/ Aviation Safety Digest 147
·~
Aviation Safety Digest 147 / xiii
�r
Search and Rescue Questionnaire
The SAR article on page 10 is the first of a series which is aimed at increasing the level of SAR
awareness. Future topics could include SAR Trained Operators, SAR Training, Supply Dropping,
and Observer Training . While there are many topics that can be covered, these would only reflect
the views of the author. What we would like to hear from you is a list of topics on SAR that can be
discussed in ASD.
I would like to suggest the following topics for discussion in future issues of the Aviation Safety
Digest:
Aviation Safety Awareness Seminars
These seminars are conducted jointly with the CAA and Aircraft Owners and Pilots
Association and the 1991 program is as follows:
•
Apart from the possible interest in reading about it, there may be some readers who wish to do
something about SAR through some form of training or learning package. So that the degree of interest can be determined, could you please indicate the type of training course or self-tutoring package you would like to be made available.
23 February
23 March
20 April
25 May
15 June
20 July
24August
28 September
26 October
23 November
Warrnambool
Canberra
Sydney
Melbourne
Darwin
Brisbane
Mackay
Launceston
Perth
Adelaide
Each seminar will be advertised widely prior to the event.
NAME
ADDRESS (optional) _ _ _ _ _ _ _ __
For further information on these seminars please contact either AOPA or the
Field Office Safety Promotion Liaison Officer.
Spin recovery Questionnaire
Please describe the various recovery
techniques as follows:
5. Unusual attitudes:
(a) nose low:
What I was taught:
1. Incipient stall
What I do:
What I was taught:
What I do:
Why there is any difference:
2. Stall:
What I was taught:
What I do:
Why there is any difference:
3. Incipient spin:
What I was taught:
What I do:
Why there is any difference:
4. Spiral dive:
What I was taught:
What I do:
Why there is any difference:
xiv/ Aviation Safety Digest 147
Why there is any difference:
(b) nose high:
What I was taught:
Safety Pr:omotion Liaison 0ff icers
Central Office
Queensland
Ian Heugh
Safety Regulation
Civil Aviation Authority
GPO Box 367
CANBERRA ACT 2601
Telephone
06 2684918
What I do:
Why there is any difference:
General comments:
Name and address (optional)
Licences/ratings held:
Total hours:
Contact phone number(working hours):
(optional; it is only to allow resolution of any
misunderstanding)
I
New South Wales
Mary O'Brien/John McQueen Telephone
Safety Regulation
02 2187111
Civil Aviation Authority
P 0 Box 409
I
HAYMARKET NSW 2000
Vic/Tas
I
Mark Perrett
I
Safety Regulation
_._
Civil Aviation Authority
GPO Box 1733P
MELBOURNE VIC 3001
Bill Taylor
Safety Regulation
Civil Aviation Authority
P 0 Box 10023
BRISBANE QLD 4000
Telephone
07 8336578
~ SA/NT
Ron Scott
Safety Regulation
Civil Aviation Authority
P OBox 2270
ADELAIDE SA 5001
Telephone
08 2180231
WA
•
Telephone
03 6678663
Bill Birkbeck
Safety Regulation
Civil Avition Authority
GPO Box X2212
PERTH WA 6001
•
Telephone
09 3236695
Aviation Safety Digest 147 / xv
•
�Aviation Safety Digest
147
AERONAUTICAL INFORMATION SERVICE AUSTRALIA
Weatherwise
flying
NOTICE
CURRENT DOCUMENTATION AND
PLANNED NEXT ISSUE
#
Document
Current Issue
Planned Next Issue
DAP(E)
13-12-90
7-3-91
DAP(W)
10-1-91
4-4-91
INTERNATIONAL
AGA 0 - l - 2
31-5-90
30-5-91
AIP (book)
13-12-90
@'
VFG (book)
13- 12-90
(~
AIP/MAP
13-12-90
*
VFG/MAP
13-12-90
*
DAH
13-12-90
*
ERSA
13-12-90
#
7-3-91
# Dates quoted are effective dates
(a
AIP a~d VFG are subject to review and a complete reissue is expected
in the first 6 months of 1991
Articles prepared by the Bureau of Meteorology in ASOs
over the past two years have dealt with many aspects of
aviation weather in order to improve pilots' understanding
of various phenomena, and thus enhance safety. This
short article sets out to provide some overall princip les for
weatherwise flying, whatever the circumstance the p ilot is in.
T
HE BASIS of all safe flying operations is
pre-flight p lanning. It is here that an
assessment of the met. forecast becomes
most important, and no rational evaluation of
t he met. officer 's work can be made unless the
content of the forecast is completely understood. Area forecasts are largely in plain
language and aerodrome forecasts, although
coded, are not all that difficult to comprehend.
OK, so you understand wh at the met. office r is
trying to tell you . What now? Well, at this stage
it is helpful to
• develop a mental picture of the weather and
r elate it to the terrain . If there are any
discontinuit ies (trough lines, fronts etc), their
impact on the desired route must be assessed .
• p la n a lternative courses of action if marginal
conditions a re for ecast - t hese important
decisions are far better made at the time of
init ial p lanning than if left until t he pilot
actu ally experien ces hazardous weather
conditions .
Op eration s in:
• remote ar eas;
• the tropical north in t he wet season; and
• u nfamiliar a reas
all require meticulous attention to weatherwise
flying. The following two extracts bear this out:
* The next issue of charts will be delayed due to implementation of new
airspace management requirements.
NOTE : NOTAM CLASS I AND CLASS II ARE TO BE READ IN
CONJUNCTION WITH THE ABOVE DOCUMENTS
ISSUE: 12
DATE: 23 SEPT 1990
xvi/ Aviation Safety Digest 147
from ASD 126
The relevant Area Forecast showed that there
was a surface trough situated close to the
Birdsville-Alice Springs track. At latitude 258
(lying approximately along the planned track)
the wind direction was predicted to change
through some 120° at 7 OOOft on QNH from one
side of the trough to the other.
The pilot had completed his flight plan using
the 7 OOOft w/ v (250/15) for south of 25° south.
However, once the aircraft was descended to
3 500ft, it w as affected by a markedly different
wind (140/15). The flight plan had not taken
this into account and therefor e the pilot made
no appropriate allowance. The altered wind
effect would have shortened the time interval
Birdsville-Alice by about 36 minutes. This
explained the navigational error, which only
became apparent at ETA Geosurvey Hill.
Navigating for long periods over featureless
terrain can be a demanding exercise,
invariably requiring meticulous preflight
preparation for successful completion. In
these circumstances, attention to weather must
be even more thorough than ever. While
weather forecasts may be tempered by in-flight
observations, a sound understan ding of the
total meteorological situation - not just selected items - is essential. The presence of the
trough near the planned route should have
been a factor to be considered by the pilot when
the change in altitude was required.
and from ASD 55
... and behind all the events and circumstances
th,at led to this catastrophe there is the fact
that the pilot was inexperienced in the ways
of the north's wet season and the particular
hazards presented over featureless areas with
great distances between even emergency landing places. It is vital for all pilots to r ealise
that weather conditions likely to be encountered in the northern wet season, especially
during late afternoon, can be a very different
proposition to the thunderstorm-type weather
normally encountered in southern Australia,
and diverting to another airfield usually
involves long flights over country where mapr eading is most difficult.
The second component of weath erwise flying is
being able to r ecognise in flight the early signs
of hazardous meteorological conditions and take
appropriate action. Signs associated w it h many
hazardous conditions (microbursts, mountain
waves, t h understorms, dust-devils etc) and recommended courses of action were discu ssed in
Digests commencing Winter 1988. It is particularly perilous to ignore signs such as the lowering and t hickening of cloud, a line of h eavy
dark clouds or roll cloud. The best safeguard in
these circumstances is probably a 180 before
the aircraft is enveloped in bad weather and
circumstances develop that are beyond the control of t he p ilot.
Finally , in-flight weather reports from aircraft
(AIREPS) can provide much valuable data to
augment t he convent ional obser vational information upon which forecasts are based D
�Aviation Safety Digest
147
Aviation Safety Digest
147
Dear Sir,
It is disturbing to read in the latest ASD the
passage 'the en route instrument rating is currently catered for by the Command Instrument
Rating, the only safe way to ever consider
flight in IMC'.
It is an inescapable fact that in the real world,
VFR pilots, if they fly enough, will be faced in
flight with non-VFR conditions at some time. It
does not matter how prudent, cautious and lawabiding they might be.
It might happen in the first few months of a flying career or it might take 20 year s. The frequency is not the point. One event is too many.
When it h appens only two courses are open to
the pilot. The pilot may be so frightened by th e
legislative prohibition against flying in cloud
that flight is attempted below the cloud base,
literally at ground level with the inevitable contact with rising terrain or some other immovable object such as power lines or a radio mast.
Alternatively , the pilot enters the cloud to find
he lacks the training and the mental discipline
to cope with the situation. It really is quite different to being under the hood in placid conditions for a Biennial review in a Cl 72. The end
result is the same in both cases.
Mr Tizzard is correct in pointing out the difficulties of precisely flying an ILS approach and
in drawing attention to the fallibility of
weather services. He is incorrect when he uses
the extreme case as the nor mal to justify his
argument. The overwhelming majority of cases
where VFR pilots get into trouble in IMC are
occasions where it is not eight octas of cloud
from the grass to the stratosphere.
It is totally impracticable to say to VFR pilots
that they must go to the exorbitant expense of
over thirty hours training, frequently in a twin,
to get a command rating and then face the cost
and stress of constant licence renewals . It is
also unnecessary because they are not going to
captain an airliner in CAT III conditions into
Sydney.
Most VFR pilots are responsible and will not
depart or continu~ flight in solid IMC. If they
are that obtuse they would almost certainly
have been killed on the roads years ago.
The consequences of the present policy are
stark and unambiguous. More lives are lost
through an inability to fly for a short period on
instruments than messing up an instrument
approach.
While being fully conscious of the need to have
the skills required to safely terminate a flight,
there has to be a facility by which VFR pilots
can safely and legally fly without visual reference to the ground for some short period.
Senator David MacGibbon
Steve Tizzard ripostes:
Senator MacGibbon's letter is in response to an
article in ASD 145, where I stated the CAA 's
opposition to an 'en route instrument rating'.
Alas, his comments, which I sincerely hope are
not merely disingenuous, serve only to
strengthen my views on this matter. As written,
the letter makes it difficult to ascertain
whether the author has any flying experience
or whether he wrote to us solely on the advice
of his constituency.
This subject is so serious that I shall deal with
the particulars of the Senator's case:
Paragraphs two to five reveal a fundamental
flaw in the understanding of what a VFR pilot
should do when faced with non VFR conditions.
The answer is
• divert; or
• hold; or
• conduct a precautionary search and landing
(all while remaining in VMC).
To continue flight in weather conditions which
preclude at least one of these options is to court
disaster. The CAA insists upon some instrument
training in the RPPL and UPPL syllabi in order
to teach pilots that the option espoused by the
Senator (flight in IMC) is highly undesirable.
I am accused of using an extreme case as the
normal to justify the argument. The five hours
thirty minutes of unexpected flight in cloud
mentioned in my article was not an extreme
case - I could cite many other instances of
extended, unforecast IMC. It was, however,
some five hours twenty seven minutes or
11314% in excess of the average time (175 seconds) the untrained instrument pilot lasts in
cloud before losing control of the aircraft.
The Senator furth er states: 'Mr Tizzard is correct in pointing out the difficulties of precisely
flying an !LS approach'. R ead ASD 145 again
and you will see that I implied almost exactly
the opposite!
The statement regarding where a VFR pilot gets
into trouble is incorrect. It is not overstating
the case to declare that the pr oblem invariably
stems from a loss of visual contact with the real
horizon and is frequently compounded by casual factors.
The facts of the matter get a bit of a serve in
the Senator's fourth last paragraph; there are
certainly four misstatements, and I may have
missed others.
'Most VFR pilots are responsible .. . ' is an
ind!ictment agairnst the intelligence of VFR
pilots.
I have great delight in finally finding some
common ground with Senator MacGibbon on
this issue, for his assertion that 'The consequences of the present policy are stark and
unambiguous' is entirely correct: current procedures have been formulated by pilots with
skill, knowledge and much experience. We
plead with you to stay out of cloud unless you
hold an instrument rating.
The Senator's conclusion again misrepresents
the facts; legislation already exists whereby
'VFR pilots can safely and legally fly without
visual reference to the ground for some short
period. ' Up to two hours, in fact - but not in
expletive deleted cloud, thank you very much.
Dear Sir,
There probably isn't a pilot around who at
some time or another hasn't been disenchanted
with ATC or Flight Service. We all know the
stories that are so often repeated whenever
pilots get together, clearances that aren't available when expected, time spent in holding patterns waiting for some controller to get his act
together, and, even worse, incident reports filed
against you by ATC or FS for some petty oversight on your part as pilot. Yes we've all
enjoyed a 'whinge' session at the CAA's
expense at some time or another. A recent
experience clearly reminded me, however, that
t he people pilots like to complain about the
most are, in fact, very dedicated professionals.
Over the last weekend in February a very big
airshow was staged at Ballarat, Victoria. By a
fortunate combination of circumstances I had a
pristine Cessna 1 70 to take to the a irshow from
Moorabbin. The flight on t h e Saturday was
uneventful and a great time was had by all; on
the Sunday another air display, followed by the
hour-long flight back to Moorabbin.
The departure was very much a 'take your
turn' affair with so many aircraft departing in
a short time-span. As many aircraft were heading to Moorabbin, I well knew that the area frequency of 124.9 would be really busy and that
Moorabbin would be 'delayed' by arrivals not a problem if you take your time and stay
ahead of the aeroplane. But sit uations can change.
The flight was proceeding normally until abeam
the small town of Wallace, whereupon the overcentre latch mechanism on the pilot's door window failed. The window flew open, alarming
everyone, especially my young daughter in the
rear seat. The slipstream was so powerful that
my wife, in the right hand seat, had to take
temporary control while I wrestled the window
shut. Once closed the only way to keep it secure
was for my wife to reach around behind the
pilot's seat and hold the latch down with her
hand. And there was still 30 minutes to
Moorabbin!
As the flight continue d Melbourne FS did not
acknowled ge any of my position reports or
ET As, but I was not overly concerned as the
area frequency was really busy and I guessed
the FSO was probably a bit over-stretched.
Once we were abeam Westgate I changed to
Moorabbin ATIS, noted the details on my flight
plan and changed to the West Arrivals and
Departures frequency of 123.0 and was it busy!
Over Brighton I attempted to contact the Tower
with my inbound call but had to wait for a
break in radio traffic to do so. Finally I made a
transmission but the radio didn't have my comp lete attention, as the traffic was the busiest I
had ever known in the Moorabbin area - it
really was 'see and be seen' stuff. I sure was
grateful for my years as a glider tug pilot,
wh ere we used to fly in busy circuits constantly
and had to be conscientious about outside
surveillance.
The controller was now advising an aircraft
that· its t ransmissions were faulty and he was
only getting the initial microphone 'click'. He
asked if the aircraft was inbound and if so to
respond with three clicks. Seconds passed nothing - but wait, he hadn't acknowledged
my inbound call! More traffic reports came in
and I began to feel uneasy as I waited a for a
further t raffic break to try again. By now I was
halfway between Brighton and Moorabbin
itself. The second try dispelled all doubt, the
controller coming straight back advising that he
had received nothing but an initial microphone
click and asks again for three clicks if the aircraft is an inbound arrival. It had to be me, and
I felt perhaps it wasn't my day - the window
episode was proving enough unplanned
excitement .
Quickly now I punched off three clicks and
prayed silently he would not be annoyed that I
didn't respond to him in the first instance.
Questions raced into my mind: Would he divert
me? With this traffic he had the right to
remove a virtual no radio aircraft out of the
control zone. Should I divert automatically?
Berwick wasn't too far away - we could get
back to Moorabbin some how to collect our car.
The aeroplane could be ferried back later after
the radio was made serviceable again.
Back came the controller and asked me to join
the circuit area but to remain at 1500ft, overfly
the tower then maintain a n upwind heading. He
obviously wanted to get a look at me before his
next instruction - was this the first step of an
�Aviation Safety Digest
Aviation Safety Digest
147
incident report he intended to file? Three more
clicks on the microphone button acknowledged
his call.
As I approached the tower, several aircraft
were already in various stages of the circuit
and while it may have been very busy at lOOOft
it was very lonely up here at 1500ft. I slowed
down to 80 kt to give the tower staff a good
chance to read my callsign and awaited the
next step. It wasn't long in coming .. .
The controller read out my callsign then asked
me to confirm, with the now customary three
clicks, that I'm the radioless aircraft. From that
point events proceeded something like this:
Do not acknowledge any further transmissions,
maintain your present heading and descend to
1 OOOft. When advised turn right on crosswind
leg. All traffic Moorabbin circuit area be
advised a Cessna 170 taildragger type aircraft
is joining the circuit without radio capability.
A few moments later:
Make right turn now and establish visual contact with a Baron on downwind; he is
approximately one nautical mile ahead of you
now.
The big Beech was exactly where the controller
said and it crossed my path just as its gear was
starting to extend. I was amazed that the controller found time and opportunity to issue such
detailed instructions in the face of a very high
workload. He had at least five aircraft (and me)
actually in the landing pattern and four, or
more, others had made initial inbound contact
w ith him over the last few minutes.
Again the controller came to my aid in guiding
me around the circuit:
Turn right on to downwind leg, there is a
Cherokee six approximately one and a half
miles ahead of you and the Baron is turning
onto final approach at this time; you are number two to land, behind the Cherokee.
This was very welcome and most unexpected;
I'm was virtually given circuit priority and
that's far different from being directed out of
the control zone. Later in the approach the controller asked me (note: asked not told) to
extend my downwind leg to allow three Pitts
Specials to land ahead of me, thus decongesting
the circuit area overall. This was easily accomplished with no effect at all on my approach.
After landing a nd securing the a ircraft I called
into the Briefing Office to say thanks. The officer on duty simply replied No worries, that's all
part of the service.
147
'Service' indeed; that ATC officer had no way
of knowing that I h ad one very tired wife jamming a window shut for me. He couldn't have
known that my car was at Moorabbin and a
diversion would undoubtedly add hours to the
time that we would eventually get home (and
all t hat with two ver y young and very tired
children). He couldn't have known that the
operator was planning to do some work on the
aeroplane the very next morning and that an
'outside' tradesman was making a special journey to do the work - very embarrassing (and
costly) if you have to cancel such an arrangement because the aeroplane isn't available to
work on.
So just remember - should you ever have a
genuine 'beef' against A TC or Flight Service
there are official - and effective - channels
available to do something about it. However,
when a pilots' clubhouse or Briefing Room
'whinge' session starts up, just think of the
times when ATS went out of their way to help
- and throw it in to balance up the perspective for all concerned.
Afternote:
The a bove took place on February 25th at
about 1800LMT on Arrivals and Departures
West frequency 123.0. Regardless of whether
the foregoing is established or not I should be
most grateful if my vote of thanks could be
passed a long through the 'system ' to the individual concerned. Oh yes, the aircraft was
VH-HSV.
Gary Crowley
Moorabbin ATC spokesperson says:
It is pleasing to read contributions from pilots
that confirm procedures working as designed.
Even more pleasing is Mr. Crowley's f eeling of
having received a good service, and on behalf
of the controller on duty, I thank him for his
kind thoughts.
The lessons for us from this article?
- The absolute importanc_e of the controller/
pilot working relationship to ultimate safety
ie; a partnership based on mutual respect
and common sense.
- The dangers of talking ourselves into a state
of mind. Because the pilot expected radio
traffic to be heavy on the FIA frequency, the
unacknowledged calls fai led to alert him to
the radio problem at an earlier stage.
- If the aeroplane is fitted with a transponder, then remember to squawk code 7600.
The pre-warning our radar colleagues can
provide as a result makes life that little bit
easier.
n
Dear Sir
Can you trust a Primary FS forecast
(Primary Zone)?
As a PPL I enjoy r eading the Safety Digest and
ponder the dilemmas of other pilots. Some of
the incidents hit pretty close to home, and I
know the feeling that you can get in t he pit of
your stomach.
I read in your 1990 Autumn edition of the pilot
examining a dry tank and only later wondering
just how the previous pilot flew in on such bare
bones. I am a class 4 NVMC rated pilot and I
know that dry tank feeling .
A potential disaster was clearly demonstrated
to me several years ago when some friends and
I decided to fly from J andakot to the Birdsville
races in outback Queensland. I flew a Mooney
201 - a delight for speed but not for comfort.
I just squeeze in at 20 stone on the old scale;
my t wo friends were thankfully both beanpoles
and lightweights.
The flight across the desert was uneventful and
hav ing to fly over cloud and get positive fixes
every 2 hours w as a challenge I enjoyed. I was
only ever two miles off track, so I was pretty
happy with my n av. Now the aero club where I
was taught to fly , like most schools, gives out
little helpers like PUFF and CLEAROF. Also,
I've always had it drummed into me to calculate fuel and distance to the gallon and the minute. Nowhere did I need it more than on the
trip out of Birdsville. By my calculations I had
55 minutes of fuel upon arrival at Birdsville.
After 3 days of fun, fights and races we were
ready to leave.
First thing, a flight plan. Second, how much
fuel will I need? Well you can't use a carnet
card at Birdsville and t he horses h a d been less
than kind to me but I knew I could get fuel at
Coober Pedy on the card. However , the fuel
operator was charging like a wounded bull at
$ 1.00 per litre. After figuring out fuel for a 90
minute flight at 8.5 gph I calculated 13 gallons
or 58 litres. I worked out I still had 55 minutes
or 8 gallons or 36 litres still in the tanks. So
needing 135 minutes of fuel I calculated I
needed 86 litres to get me to Coober Pedy, so I
bought 50 litres. I was right on the nose for
fuel plus reserve.
method and use 10 minut e sections to calculate
fuel, position etc. On t he climb I lose a bit and
pick it up on descent, so for the first 20 minutes I expect some variations or discepancies.
At the 30 minute check I started to get an
uneasy feeling that perhaps things weren't
quite right; maybe the forecast wasn't too
accurate.
We weren't where we should have been and I
was getting positive fixes due to the unusual
terrain. The plane was operating correctly, s he
was trimmed and leaned out to the maximum.
The further we went the further my doubts
grew. Shortly we would reach PNR and a
decision would have to be made. I calculated
that, instead of the 20 kt tailwind forecast, I
was copping a 30/ 40 kt headwind. I checked the
forecast again to see if I'd got it wrong, but no,
my calculations were right in line with what
met. had said. It was a bit hard to start cursing
t he guys at the FS while you're trying to think
quick; anyway the only thing I could think of
started with 'F'. Oodnadatta was starting to
look good and fuel and distance checks took priority over profanit ies.
Still 50 m inutes to go and we should get down
with 30 minutes fuel spare. Now 30 minutes
approx . and only about 20 minutes to spare.
God! the headwind is still increasing!
20 minutes from Coober Pedy I put her into a
gentle descent and cut the power back a bit but
maintained airspeed.
I can see Goober Pedy and we're about 10 minutes out and by my reckoning I've about 10
minutes of fuel over that required. I'm trying to
hold that 10 minutes in the left tank in case the
right one runs out so I'll at least know there's
10 minutes to get her down on a road or
something.
I was never so happy to see t hat runway on my
w ingtip. Downw ind, then as I crossed t he
threshold the fu el light was flashing low fuel.
That feeling w hen we touched terra firma was
one of unbelievable relief.
When I look back I'm ever so grateful my
instructor told me CLEAROF, PUFF on final,
and check fuel and position ev ery 10
minutes.
Afternote:
we were 2nd in line to take off at first light
and it was r eally quite spectacular to see 30 to
40 aeroplanes lined up behind us blowing up a
duststorm.
Can we trust the forecast? Usually we can, but
I keep a check myself just to make s ure. And
yes, the tanks were so dry the dipstick didn't
register any fuel at all. (At Birdsville due to the
number of planes coming - about 400 - t hey
set up a Primary Control Zone for those 3 days).
We took off about 0605 local and proceeded on
track to Coober Pedy. I work on the CLEAROF
M J Donnes
�Aviation Safety Digest
147
Danger in numbers
John McQueen, E of A (GA),
gethomeitis, particularly when there is no-one
else in the aircraft to counsel otherwise, is a
prime example of bad rationalisation. However,
it is the cumulative effect of artificially positive opinions that is so insidious in groupthink.
Safety Promotion Officer CAA NSW
W
E ALL KNOW the strength of teamwork
and that two heads are better than one,
but have you ever stopped to think that
this is only true if the correct principles of
teamwork are applied? If they are not, there is
definitely danger in numbers. Let me explain:
Have you ever observed the behaviour of a
group? A crowd of teenagers on the train? A
sporting team in the pub? The office party?
Groups demonstrate markedly different
behaviour-patterns to those followed by their
members acting as individuals.
Why is this so? Well, there are a number of
reasons and it's important that you understand
them if you belong to any organised group, say
an aero club or parachute club or if you are
engaging in any organised activity like a safari.
Should you be a member of a flight crew, you
must be particularly aware of some team
characteristics that can be dangerous.
Negative aspects of team action are known in
psychological jargon as groupthink and arise
because each member subconsciously wants to
nurture the nice secure feeling experienced in
being part of the group. I'm sure you can think
of examples you have seen or perhaps been
involved in yourself. Let's run through the
symptoms:
Invulnerability - We Can Do Anything
The group shares the illusion of impregnability;
this can lead to over-confidence and a willingness to take unnecessary risks. There may even
be a failure to respond to clear warning signs of
danger. I'm sure you've all competed against
the 'A' team - you know, the ones who know
they can't be beaten at anything!
Rationalisation - She'll Be Right Mate
Rationalisation is when you attempt to defend
your actions by a process of selective justification - that is, eagerly accepting reasons for
doing something while ignoring indications that
perhaps you should think it through at least
once more. A group is particularly prone to
rationalisation because each member can
usually think of something to support a desirable course of action. In reality, though, they
may be putting themselves into a situation an
individual would recognise as perilous. Of
course, this is not confined to group action -
,Morality - Anything Goes
Members of a group can begin to believe in a
joint inherent morality that differs from their
personal standards. This belief can cause members to ignore the ethical or moral consequences
of their actions. This symptom is very prevalent with sporting teams (win at any cost), but
could apply to an aviation group (we're here to
make money) and cause it to disregard SOP's or
regulations.
Peer pressure - We're All In This Together
If an individual has doubts about the decisions
made by the majority, there can be direct pressure applied to achieve a change of mind. This
type of behaviour is vividly illustrated in the
movie Twelve Angry Men, which shows such
pressure affecting due process by a jury in a
seemingly open-and-shut murder case. · Junior
members of flight crew can be very susceptible
to peer pressure unless crew discipline
reinforces their training.
Time pressure - Let's Get On With It
When making a decision, members of a group
are often more concerned about the constraints
of time than the quality of their conclusion. For
some reason time becomes more important than
the task. The group can start to become anxious
if a decision isn't made quickly and will accept
the first suggestion that comes along, even if it
suspects that there may be serious repercussions later on.
Filtering - No Problems!
Some members of the group subconsciously (or
even consciously) regard themselves as minders
to protect the leader and other members from
information that may destroy apparent harmony and wellbeing. Taken to extremes this
could involve not giving the leader information
vital to the group's security.
These are the main symptoms of groupthink.
What can we do to counteract them? The
answer lies in good leadership. Leaders must
use their influence to encourage, motivate and
stimulate people to do things. There is no set
way to achieve this, but the key factor is the
relationship between the leader and the team
members. A good relationship with a trusted
and respected leader makes the exercise of good
influence and authority very much easier.
Self-censorship - What Would I Know?
If t he group has made a decision, there is a
tendency for an individual to keep quiet even
should doubt exist. They may even try to convince themselves that they can't be right
because the group must know best. It could be
described as a subtle kind of peer pressure,
inhibiting an individual from even beginning to
question anything that is supported by an
apparent strength of numbers.
Unanimity - If We All Agree, We Must Be Right
The effects of unanimity are partly caused by
self censorship. If an individual remains silent
during the decision-making process the group
can make the false assumption that everyone is
in full agreement. The resultant illusion is
therefore shared by most members in any
judgement expressing a majority view.
Good leaders
• understand the correct process for decision
making
• try to involve every member of the team
because everyone has something to contribute
- it may only be one piece of information but
the one that is vital to the success of the mission
• allocate duties to the most appropriate person
and recognise and respect their expertise
• communicate clearly and supervise fairly by
acknowledging a good performance and correcting a poor one
• focus on individual needs so that everyone
can develop knowledge and skills.
A team that is contributing, well-led, committed
and aware of the dangers of groupthink can be
very effective in achieving the task. It can demonstrate that there is also safety in numbers and unlimited potential 0
Nil.4 J)l~l~l~C~'l'S
Rats in the
airframe
Ralph Murphy, Senior Airworthiness Engineer
Aircraft Structures
UCH AS ANCILLARY aircrew may argue
the point, we're not here talking about
pilots. Rodo, rodere, rosi, rosum, are
parts of the Latin verb 'to gnaw', and it is no
mistake that this has been used to form the
stem of the words 'rodent' and 'corrosion', for
both of these can surreptitiously eat away
those things we hold vital to our well-being.
M
Q. Why do metals corrode?
A. Entropy (look it up). The ores from which
the end-product is refined have probably lain in
the earth for millions (billions?) of years, and
the process of disorganisation that entropy pursues is very well advanced. To such an extent,
in fact, that the ore is an extremely stable substance. Left alone in the ground it probably
wouldn't change for another few hundred thousand years.
But, contrary to what appears obvious, metal
as we know it, having had much energy
expended on the refining process, exists in a
highly reactive unstable state. It spends its
time, if you like, trying to return to chemical
stability - back to an ore, in fact (see again
entropy). Given a bit of help from chemical or
electrochemical action - and an electrolyte can
be as simple as mere water with some dissolved
impurities - your lovely alloy will happily
revert to oxides, hydroxides and sulphates etc.
This quite normal atavistic process is bad news
for us, and is described in scathing terms as
'rust', 'scale' or perhaps 'corrosion products'.
In aviation, we are most suspicious of corrosion
because we continually seek to produce aircraft
materials with higher and higher strength-toweight ratios. The downside is that in many
cases such materials have very poor inherent
corrosion resistance. Thus, the prevention, or at
least a deceleration of corrosion is crucial to the
integrity of all aircraft structures.
Corrosion prevention on aircraft is initially
achieved by:
• careful selection of materials
• corrosion control treatments s uch as plating,
anodising and painting
• special assembly techniques
• careful detail design
However, the long-term effectiveness is determined by the maintenance of the aircraft.
Owners and operators must ensure:
• adequate cleaning of the aircraft
• early recognition and treatment of corrosion
• restoration of paint systems
• cleaning up spillage of corrosive substances
• drainage and removal of trapped moisture
Corrosion, very like cancer, can be kept at bay
by wise preventative procedures, and may be
cured completely following early detection and
treatment.
Any unexpected or unusual corrosion should be
reported to the CAA via a Major Defect Report
(MDR) so that the CAA can investigate any pattern that emerges and can help other owners
and operators.
�Aviation Safety Digest
147
Aviation Safety Digest
147
•
•
lntergranular:
The most common forms of corrosion are:
Galvanic:
•
•
Paint
Primer
Clad
Al alloy
•
Dissi;nilar metal
Anode, corrosion
location
© Aluminium oxide
.,.. Moisture
e
Symptoms: Powder-like white or
grey deposits.
Cause: two dissimilar metals in contact in the presence of an electrolyte. Carbon fibres (as used in some
advanced composite materials) in
contact with metal can also set up
galvanic corrosion.
e
Symptoms: Usually only noticed as
cracking. It is typified by an apparent increase in the corrosion rate
with time.
Cause: Chemical and electrolytic
action along grain boundaries in the
material; some alloys are highly susceptible to this action. Breakdown
in the surface coating can allow
moisture and corrosive agents to
enter.
@
••
•
Fretting:
Exfoliation:
Symptoms: Flaking and loss of
metal through the thickness of the
material.
Cause: Corrosion proceeds from
exposed grain ends along planes
parallel to the grain surfaces. The
swelling of the corrosion products
forces metal away from the body of
the material giving a layered
appearance.
Stress:
Symptoms: Usually only noticed as
cracking, with fast crack growth
and possible subsequent failure.
Cause: Sustained tensile stress in a
corrosive environment.
•
•
. , : '')9
Paint
Primer
Al alloy
Anode, corrosion
location
€l Aluminium oxide
.,.. Moisture
Symptoms: Combined wear and corrosion between contacting surfaces
which are subject to slight relative
movement. Ferrous metals often
show red material oozing from
between the surfaces and light
alloys display black deposits and/or
streaking.
Cause: Abrasion of metal under load
in a humid environment
®
••
•
Crevice:
•
•
®
Paint
Primer
Al alloy
Aluminium oxide
Moisture
Symptoms: Severe localised corrosion at narrow openings or gaps
between metal components.
Cause: Penetration of a corrosive
agent into a joint, often due to
flexing. Faying surface sealants
should be correctly applied.
®
Symptoms: Corrosion occurring
beneath paint in the form of random threadlike filaments. Often
causes paint bulging as blisters.
Cause: Moisture and corrosive
agents that reach the metal through
cracks or damage in the paint and
set up active corrosion cells. Particularly severe in h~gh humidity,
marine and industrially polluted
environments.
•
Paint
Primer
Clad
•
Al alloy
Anode, corrosion
location
® Aluminium oxide
.,.. Moisture
e
e
•
Pitting:
Symptoms: Localised pits or holes in
the surface of the material. Can be
quite deep and serious.
Cause: Corrosive agents setting up
small electrolytic cells. Surface
should be clean and the surface
coating kept in good condition to
minimise the risk of pitting.
Paint
Primer
Clad
Al alloy
Anode, corrosion
location
€l Aluminium oxide
.,.. Moisture
e
e
Paint
Primer
Al alloy
Dissimilar metal
Anode, corrosion
location
Aluminium oxide
Moisture
Primer
Al alloy
•
Fungus colony
Anode, corrosion
location
~ Micro-organisms
Symptoms: Local surface attack or
formation of deposits such as fungi.
Cause: Growth of micro-organisms
in moisture traps. Occurs
predominantly in aluminium integral wing fuel t anks that use kerosene based fuels . The organisms
feed on the t ank lining, exposing
the structure to electrolytic attack.
These represent perhaps the most common
forms of corrosion; there are many others t hat
can occur under given conditions. However,
whatever the particular variety encountered ,
effective treatment, as said earlier, begins with
accurate reporting and prompt counteraction.
Look carefully; look again - then do something
about it!
Paint
Primer
Al alloy
Corroded area
Aluminium oxide
•
Micro-biological:
Filiform:
Paint
Primer
Clad
Al alloy
Anode, corrosion
location
Alµminium oxide
Moisture
Grateful thanks for the ideas and particularly tor the pictures to:
FAST, Airbus Technical Digest
Airbus lndustrie Product Support
Blagnac, France D
�TO
'You scratch my
back ... '
Warwick Bigsworth
Manager, Sydney Airport Capacity Enhancement
N EARLY 1989 I had the opportunity to lead
a small group of very experienced Australian
Air Traffic Controllers on a visit to several
North American airports. The purpose of the
visit was to see if we could learn something
from the Canadians and Americans about
efficient airport operations and reducing delays,
and to put such practices, procedures and standards into effect in Australia.
I hope and expect that most aircrew and air
traffic controllers will have already noticed
some recent improvements to the efficiency of
the air traffic services system; these have
resulted from recommendations arising from the
visit to North America. Improvements to SIDS,
more realistic runway selection criteria, revised
wake turbulence separation standards, new simultaneous runway operations standards and
improvements to the ATC management structure are all items which have been introduced
or will be introduced by the end of 1990. The
industry and the CAA are also considering recommending to Government means to improve
noise abatement procedures, recognising that
many of the restrictions were imposed in the
late 1960s and the improvements to aircraft
noise emissions and performance, whilst also
ensuring that the community is not adversely
affected.
Perhaps the most outstanding revelation to my
group was the attitude and esprit de corps
between North American aircrew and air traffic
controllers. Readers will be aware of the enormous amount of a ir traffic processed in North
America and the need to keep aircraft moving
whilst minimising delay. One important item
which is necessary' to achieve that is the joint
effort required in co-operation by pilots and
controllers.
There are a number of important items which
the air traffic controller can do to make an airport and airways system work more efficiently,
particularly in keeping the pilot informed. Consider how many times on departure you as a
pilot have just selected parking brake on, when
only a moment later you are cleared for takeoff or to line up. How often have you reported
ready or leaving an altitude and there has been
either a long delay in, or no acknowledgement
from ATC? Have you:
I
TO
AIR
• ever just commenced descent on profile and
suddenly have been told by A TC to reduce to
60 kt below your desired optimum speed?
• been caught in the position of being at 3000 ft
and 7 nm from touchdown in an unpressurised
aircraft and then asked to make a short
approach, and keep the speed up?
• ever just entered the holding pattern, only to
be told to cancel holding and resume desired
speed?
Do some of these scenarios sound familiar? If
only you had been given some forewarning, you
might have been better equipped to comply. On
the other hand, controllers don't issue instructions without valid reason, but forethought and
keeping pilots informed obviously gives them a
better chance of ensuring a smooth, 'safe
operation.
But how does the controller feel about some of
the things that pilots have been known to do?
• When your aircraft is cleared for take-off, do
your take more t han just a few seconds to roll?
• When you are at the holding point and have
been cleared for take-off, do you line up and
stop?
• Do you land and use minimum braking just for
your own convenience?
• Do you always try to vacate the runway on
the first available taxiway?
• Do you argue or whinge over the radio?
• Do you advise you require a different runway
when you are arriving at a major airport and
only have a few miles to run for the nominated runway?
• When operating outside radar coverage, do
you always advise A TC of amended ETAs?
• Do you readback clearances, assigned levels
and transponder codes?
I'm sure that most controllers will be very familiar with these frequent occurrences.
In North America, the above problems rarely
occur because there appears to be a better level
of co-operation and understanding between controllers and pilots. It seemed to u s that everyone wanted to ensure that they did their part in
contributing to a safe, orderly and efficient
flow of air traffic. If pilots or controllers don't
fulfil their obligations and compromise the
safety or convenience of others, he's made well
aware that he could be the victim on another
occasion.
The following tips, if regularly practise d by
pilots and a ir traffic controllers , would make a
significant contribution to the safe, orderly and
expeditious flow of air traffic at Australian
airports.
AIR
Pilots:
Air Traffic Controllers:
• Keep the pilot informed; the pilot cannot read
your mind, so, for example, when you want
an aircraft to roll as soon as the runway is
clear, give the pilot that expectation.
• Advise speed restrictions as early as possible;
it can be quite difficult to descend on an
acceptable profile if late notification of speed
restrictions are made.
0
• Don't forget to give t he pilot trac1< miles to
run; the pilot can t hen gauge t he rate of
descent in a more precise manner (it contributes to noise abatement as well).
• If you need the aircraft to expedite, tell the
pilot; a pilot will vacate t he runway quick
smart if he knows there is another aircraft
close behind.
• Endeavour to keep taxiing aircraft moving; be
prepared for those 'ready' calls and ensure
departures clearances are at hand. Think
ahead.
• Endeavour to use sp eed control rather than
holding; with a bit of forward planning most
pilots will reduce en-route cruising speed
much more happily than having to enter a
holding pattern. It usually sav es fuel and
reduces workload on t he part of both controller and pilot.
• Keep in mind the r elationship of miles to run/
speed / altitude; this applies particularly to
non-pressurised aircraft, but can cause significant difficult ies to pressurised aircraft a s well.
• Try not to cancel a SID in the same breath as
clearing an aircraft for immediate take-off;
the pilot has set up the instruments for a SID
and no doubt h as gone through a briefing on
the same. There is a good chance he might not
be able to expedite take-off safely.
• Advise the pilot of t he reason for a delay, if it
is not otherwise apparent; if the aircraft is at
the holding point and reported ready and
there does not seem to be other movement,
explain the reason for t he delay. Similarly,
when the Approach frequencies are split and
your one aircraft is being delayed by speed or
radar vectoring, give its position in t he
sequence and expect ed landing time.
• Use correct and courteous r adio procedures;
don't shortcut call signs or clearances, and if
extra advice to pilots is necessary, do it postlanding over the telephone. 'Good morning' or
'good afternoon' never causes offence.
• Enter and vacate the runway exp editiously; if
you have reported ready, ATC expect you to
move onto t he runway as soon as cleared.
Long landing rolls j ust to save t he brakes or
to get closer to y our terminal only delays the
aircraft behind you. Tomorrow it may be you
who suffers.
• Commence rolling immediately w hen cleared
for take-off; w hen cleared to line up you
should be spooled up , checks complete and
ready to go.
• Advise ATC a s early a s possible when you
require a runway other than that nominated;
it is no u se expecting original priority if you
suddenly advise that you require a runway
contrary to the traffic flow.
• For departure, advise ATC at or before clearance request; on arrival, preferably prior to
top of descent.
• Don't whinge or argue over t he radio; human
nature being what it is, arguing will only cr eate acrimony. If you have a legitimate complaint, telephone ATC after you have landed.
• Provide t he earliest revision of estim ates;
when outside radar coverage your Sarwatch
and separation is dependent on your navigation and est imates.
• Read back clearances and assigned levels correctly; abbrev iated readbacks can lead to misunderstandings a nd incorrect assumptions.
• Use correct and courteous radio procedures;
short cuts cause confusion and can lead to
incidents.
Many pilots may not be completely familiar
w ith the CAA's Air Traffic Services system.
Nearly everywhere pilots are welcome to visit
A TS facilities and see how t he system works. A
call to the local ATS Manager will usually get
you an invitat ion to the Unit or Centre at a
mutually convenient time. Such a visit might
lead to a better understanding. Certainly, a s
was said in a recent Digest, it'll score you a cup
of CAA coffee!
[Has anyone else noticed the extraordinary politeness and patience of the average A merican
car driver? Even on the spaghetti junctions of
Los A ngeles? Could it be that Australian driving habits r eflect a national characteristic?
Does our closely-held individuality and, let's
admit i t, our aggression, spill over into our
behaviour as pilots and Air Traffic Controllers?
- ed} D
�
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1990
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https://collections.heritageoftheair.org.au/files/original/fa22cd47b1ffd2400c909197ec89255a
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Text
30SECONDS
That's all the time it takes
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�Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots), registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
Manager, Publications Centre, P.O. Box 1986
Carlton South, 3053, AUSTRALIA
Telephone (03) 342 2000(4 lines); 008 33 1676
008 33 4191; (03) 347 4407
Contents
4
Unless otherwise noted, articles in this
publicat ion are based on Australian
accidents, incidents or statistics.
Reader comments and contribut ions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the material without altering
the author's intended meaning.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Telephone (06) 268 4583
©Civil Aviation Authority 1990
ISSN 0045-1207
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
Keeping us on the straight and
narrow
7 30 seconds to save your life
8
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The articles
are intended to serve as a basis for discussion
and even argument in an effort· to identify and
resolve problem areas and potentially
hazardous situations.
Editorial
The heat of the moment
10
Christmas comes but once a
year . ..
12
Unauthorised descent -
12
Quiz
13
Field Office Forum
14
Accident Response
16
Airflow
18
Flash
20
Trial by fire
22
Ground to air
Hobart
When you break out at DA/MDA it's good to
see the runway lights where you expect them to
be, and if you as a matter of course fly in all
sorts of weather it's better still to be confident
that the approach aids will always work as
advertised (I'm assuming that you are assiduous
in your callsign, warning flags, CDI and altitude/
DME checks). Enroute, too, it's nice to know
that your DMENOR fix puts you where you
really are. All these, plus NDBs, are in such
constant use that I believe the article on navqid
calibration will be of great interest, for the job is
done by people who are pernickety in their
standards of accuracy. Since we've introduced
a Dickensian term, we'll now misquote him: the
crews of the calibration aircraft do put too fine a
point upon it, and we fly all the more safely as
a result.
Covers
Front: CAA F28 calibrating Canberra !LS
Photograph: Bluey Thompson,
July 1990
Design:
Sean Silvey
Back: 'Extra Hazard Check'
by Andrew Rankine
CAA Graphic Design Studio
It seems you don't have to be flying your aircraft to incur great expense. There's a good
message from the Bureau of Meteorology in the
advice that moderately severe storms occur
fairly frequently as you approach tropical Australia. Are you really happy that your tie-down
procedures will protect your precious investment
from a 50kt wind-squall? Perhaps it's a word to
the wise, who will double check the security of
their parked aircraft - to get caught out might
spoil that idyllic weekend by the sea.
Once again we're pleased to run a photo competition. I want to emphasise that although artistic prowess bears heavily on the result of two
categories, the main prize could be won with a
mere snapshot - it's the aviation safety message that we're seeking and everyone is encouraged to have a go.
Concerning Ground to air in this edition: please
be advised that as a result of a recent Aviation
Regulatory Proposal, the whole question of
operational control in Australian airspace is now
under review.
Editor:
Editorial Assistant:
Roger Marchant
Lyn Coutts
Diagrams:
Shirley Wheeler
Kathy Foldszin
Pl
Photographs: P4&5
Lyn Coutts
P6
CAA Flying Unit
PB
Brenton Hollitt
P11
Harvey Turner
P18&19 Stuart Westmorland
taken in Seattle
P20
BAS/
�r
Aviation Safety Digest
146
Aviation Safety Digest
146
Keeping us on
the straight and
narrow...
The contract to purchase the F28s was signed
in 1974 and the first aircraft was delivered
during December 1976. The choice of F28 aircraft was influenced by the following factors:
(1) an equipment load of up to 3000 kg to calibrate all civil/ military airways facilities;
(2) forward-facing consoles;
(3) fitment of up to 50 antennae;
( 4) large underfloor cargo area to carry support equipment and ground tracking
systems;
(5) low tyre pressure for the aircraft to operate from unsealed runways;
(6) aerodrome performance to access 1600
metre runways;
(7) high cruising speed in the order of Mach
0. 7 (420 kt) and range sufficient to reach
Perth (2871 km) or Darwin (317B4 km)
from Melbourne with only one refuelling
stop;
(8) good low speed handling and go-around
performance from very low altitude
(9) compliance with the noise standards; and
(10) program cost
There are over 800 navigation aids in Australia
and PNG for which CAA holds in-flight calibration responsibility, including a few
privately-owned facilities and t hose operated
by the Department of Defence at the various
RAAF and RAN bases around the country. Each
facility has to be checked, not only on a rout ine
basis with time intervals varying from six
months to two years, but also to reinstate an
aid following modification, primary component
change or failure.
Every day in Australia tens of thousands of passengers fly
safely and confidently by virtue, in part, of the precision,
accuracy and reliability of the navigation aids that delineate our airways and provide approach paths to many
aerodromes. However, these admirable characteristics are
neither easily nor cheaply maintained. In the following
article Leon Norsworthy, Assistant General Manager of
the CAA Flying Unit based at Essendon Airport, Victoria,
explains the role of his organisation and sets out the
reasons for the use of what some might see as possibly a
too large and too high-tech aircraft, the F28.
Navaid Calibration in Australia
The blue and white aircraft of the CAA's fleet
are a fairly familiar sight at many airfields
around Australia, as they go about their tasks
of route surveying, providing currency flying
for CAA specialist pilots and transporting
officials around the country on their various
technical, operational, surveillance and examining duties. The most common CAA aircraft to
be seen by the average General Aviation pilot is
either the Beech 35 or 36, or the Gulfstream
1000 turboprop light twin. However, the other
CAA type, although there are only two in the
fleet, is much wider ranging and puts in regular
appearances at many Australian airports. This
is the Fokker F28 twin jet, which is prima rily
used for the calibration of Australia's civil and
defence aeronautical radio-navigation aids.
i
v
In the 1970s, the F28 surpassed its competitors
in complying most closely with the criteria and
was a natural selection. In the intervening
years, the criteria have changed little; for
example, the equipment load is now about 2500
kg. The F28 has proved to be an excellent ·
choice and since its introduction 13 years ago
has been more than satisfactory in performing
calibration and flying training tasks . Moreover,
the economic predictions based on operating
this highly reliable and utilitarian aircraft continue to be fulfilled through the achievement of
major program cost reductions over the years.
The F28, along with the rest of the fleet, give
excellent value for money.
The F28s are operated by the CAA's Flying
Unit, from its Headquarters at Essendon Airport in Victoria. Calibration missions can last
up t o ten days, covering t he Australian FIRs
from Cocos Island in the West to Norfolk Isla nd
in the East plus Papua New Guinea on a contract basis.
Each F28 is fitted out to enable it to fulfil its
calibration role with equipment that is
additional to that installed as part of the
aircraft's normal av ionics. The equipment is
operated by specialist technical personnel
seated at two consoles in the forward passenger
cabin. The test equipment is itself subject to
rigorous test and calibration sequences by the
Flying Unit's Laboratory, as part of ensuring
compliance with the national measuring
standards.
Rout ine calibration methods for NDB and DME
do not call for any particular operational t echniques - the aircraft is usually flight-planned
to pass within range of the nominated facility
and the various signal characteristics are
recorded and compared against previous results
to detect any change. If a fault is detected, the
ground technica l staff responsible for the aid
are adv ised, and t hey rectify the defect. With
some of the remote sites, the technical staff can
be several hundred kilometres away by road,
and in s uch cases, a repeat flight is arranged to
coincide with their presence at the site to confirm that t he defect has been corrected.
As part of the current inst allation, there a re a
total of 39 dedicated flight inspection antennas
fitted to the aircraft to inspect th e performance
of NDB, DMEA, DMEI, TACAN, LLZ, GP, VOR,
MKR, SSR together with VHF and UHF communications facilities. In addition, t he aircraft
can be used to calibrate GCA/ P AR and VASIS,
although these facilities do not require any
specialist electronic equipment apart from discrete VHF/UHF communications, and ground
tracking equipment (eg. t heodolite).
Calibration of those aids which prov ide precise
t rack guidance, such as ILS, is more complex.
With ILS, t he Localiser and the Glide Path ar e
calibrated as separate elements; the signal
characteristics such as alignment and width,
and the behaviour of the installation under the
various alarm conditions a re measured in comparison with a very accurate automatic tracking device which provides reference data on the
aircraft's flight path.
�Aviation Safety Digest
Aviation Safety Digest
146
This tracker, which was developed 'in-house' by
the then Department of Civil Aviation, uses a
vidicon (light-sensitive video receiver) to track
a high-intensity, gyro-stabilised light on the
nose of the calibration aircraft, and can
measure angular displacement to within .01°.
The tracker is set up near the ground antenna
of the element to be measured, and tracks the
calibration aircraft as it makes a series of
approaches. Movement of the tracker head as it
follows the aircraft is converted to a digital signal and then telemetered back to the aircraft on
a discrete VHF channel where it is compared
electronically to the incoming signal from the
Localiser or Glide Path and the results recorded
on a multi-channel recorder. As the flight test
progresses, the Flight Surveyors at the consoles
monitor the results and advise the ground party
of any adjustments which may be required. A
typical routine flight test of a Localiser or Glide
Path will require from eight to twelve
approaches and consume some 75 to 90 minutes
flight time, with every alternate flight test
(annual) being carried out in greater detail,
measuring more parameters and requiring
additional approaches.
The piloting and measuring tasks require a high
degree of concentration and teamwork within
the crew, not to mention a high degree of precision and skill on the part of the pilots. As can
be appreciated, the presence of faults and
delays caused by other traffic can extend the
flight time. For one survey at a two-ILS major
airport the requirement was to do a routine
check on one installation and an annual check
on the other; several adjustments were necessary in the navaids, which resulted in the crew
performing no fewer than 73 ILS approaches in
two and a half days.
146
VOR calibration is less complex, but the technique still requires the use of an independent
ground-based measuring device in the form of a
very accurate pilot-balloon theodolite. The
theodolite is set up at a previously surveyed
position near the VOR and the calibration aircraft flies an orbit around the site at a radius
of six nautical miles and an altitude 2000 ft
above the site elevation. The altitude can vary
for particular sites, depending upon local terrain; at Cairns for example, the orbit is flown
at 4000 ft and the site elevation is almost at
sea level. As the aircraft is flown around the
VOR, it is tracked with the theodolite by the
ground party, and the magnetic bearing is
called, on a discrete VHF frequency, every ten
degrees. The bearings are compared with those
radiated by the beacon and received by the aircraft and the results recorded and compared
with those found on previous tests .. The orbit
establishes the basic alignment of the beacon
and, if necessary, adjustments are made to
bring the system into tolerance. At the completion of the orbit the calibration aircraft then
flies a series of route radials out to a distance
of 12 to 15 nm, to check such parameters as
course quality, bending, scalloping etc while
being tracked with the theodolite. Bearings are
again called by the ground party and compared
with the data received in the aircraft. Up to
twelve radials will be flown, selected from the
published routes, to provide a representative
picture of the facility through 360°.
From the test crew's point of view, ILS and
VOR calibration work is the most int-ensive part
of their duties, requiring considerable concentration for comparatively long periods of time.
Calibration of TACAN and GCA is also demanding, as they are variations on the ILS/VOR
theme.
All ILS installations in Australia are situated
within controlled airspace, at least at those
periods when th ey will be calibrated. With the
willing co-operation of ATC, traffic separation
is rarely a problem, and ATC will, where possible, fit the calibration aircraft into the traffic
pattern to enable the task to be completed with
the minimum delay and the maximum
efficiency. The same situation applies with
checking VORs within controlled airspace. However, many Australian VORs are sited outside
controlled airspace, where the responsibility for
traffic separation rests with the individual
pilots.
In si.xteen years with the Flying Unit, CAA pilot
Brian Surtees has managed to average one !LS
calibration run per F28 hour flown (he has some
6000 hours on type).
Calibration operations OCT A place significant
extra demands on the crew, as t hey not only
have to concentrate on the calibration task,
with its demands for precise flying, but they
can be required to monitor up to three communications frequencies, as well as look out for,
and keep mental track of other aircraft in the
vicinity. Over the years, there have been
occasions when separation standards have
broken down. The message for all pilots flying
OCTA is, of course, to keep your eyes open at
all times, but to pay particular attention when
operating in the vicinity of any navigation aid,
which by its very nature, will act as a focal
point for air traffic. Even if it is not required
by the VFG/ AIP, don't hesitate to broadcast
your position and intentions if you think it may
help some other airspace user. The CAA 's F28
flight inspection crews welcome early traffic
notifications.
The task of navigation aid calibration is important to all sections of the aviation industry,
from the international Boeing 7 4 7 operator to
the Aero Club or Flying School student pilot,
yet it is probably fair to say that few pilots
have ever given it much thought. The calibration crews perform a valuable quality assurance task, so that when you, the pilot, tune in a
beacon and correctly identify it, you can be
sure that it is feeding y ou the 'right stuff'.
A recent audit of the task recommended:
(a) A complete review of flight survey procedures and techniques of existing facilities
and the introduction of procedures, techniques and standards for anticipated new
facilities eg. MLS. This is expected to result
in fewer hours being flown to obtain the
same results as are achieved at present.
(b) Upgrading of flight inspection measuring
systems to automatic systems with the following prospects:
(i) less payload requirement (a reduction in
total payload from 3000 kg to 1560 kg)
(ii) less space required for racks/ consoles
(decrease from 6 cu.meters to 2.7
Cu.metres)
(c) automatic systems to analyse more data and
give insta ntaneous results with less manpower requirements (one Flight Surveyor
for enroute aid checks and two Flight Surveyors for ILS/ MLS checks as against the
present survey crew of three).
However, new systems are costly and range
from $3.0M to $5.0M per system without
spares, laboratory and introductory costs. Technical and operational evaluations are underway
which, when complete, will lead to an economic
and financial analysis of the best airborne system and aircraft combination to satisfy
Australia's requirements into the next century.
A final word - any time you see one of the
blue and white F28s on the ground at any airport, go up and introduce yourself to the crew.
They'll make you feel at home, and will be
happy to show you over their aircraft and
explain their job. If you' re lu cky, you might
even score a cup of CAA coffee! D
30SECONDS
That's all the time it takes
,
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let down, pull
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run itself for
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Wherev er possible carry out clean
up runs away rrom wires so that
the problem has been dealt with
and preferably into wind lo
reduce groundspeed
30 seconds to
save your life!
John Freeman, our Examiner of Airmen (Agricultural) has
asked once again that we publish a plea to all ag. pilots.
In ASD 142 (Spring 1989), John wrote at length about wire
survival, and a late entry in that edition (page x) referred
to the sad death of yet another high-hour very experienced operator.
G. OPERATIONS necessarily mean flying
close to the limits - all the time: to retire
from the game fit and well means extreme
vigilance and self-discipline - all the time. It is
not pleasant to have to record that over the last
two years we have lost twelve pilots (seven to
wire strikes), during agricultural operations.
John has identified the 'extra hazard check' as
being vital to continued safe ag. operations:
You've done a good job, and covered the area
in an efficient and economical way. Now it's
time for the clean up run. Is i t just possible
that your defences have slackened a little?
John thinks this might sometimes be the case,
hence his p lea for the extra check. The Ag.
Pilots Manual carries a large segment on wires,
their location and avoidance; don't be too proud
to take its advice.
The check takes so little time - see the heading. The representation above and on the back
cover is John's example of a method of
rechecking hazards affecting clean-up runs.
Oh yes, one more point . The human short-term
memory is a fragile thing, so if you depart the
treatment a rea for an hour or so, p lease do a
quick extra hazard check upon your return,
before you restart operations [j
A
�r
Aviation Safety Digest
146
Aviation Safety Digest
146
The heat of the
moment
Pilot contribution by P J Little
HE FORECAST was not good for my trip
from Bankstown to Glen Innes but not bad
either. Some low cloud was forecast for
Armidale, where I needed to refuel on the
return trip, and isolated thunderstorms
thereafter with a 20% possibility of isolated
thunderstorms forecast for Bankstown on our
return. Glen Innes had an amended TAF which
was good. It was hot everywhere.
With the exception of a 30 minute delay in
taking off, when they lost my flight plan, the
trip to Glen Innes with my three passengers
was uneventful. Having completed our business,
we were delivered back to the airport in fine
weather and gooti time, our host departing
before we boarded the aircraft.
T
A check of the tanks and oil and a quick check
of the aircraft then we were strapped in ready
to start. The engine turned over a couple of
times and then nothing, just a clicking sound.
The starter motor had gone dead and nothing I
did would induce it into life again. We deplaned
and I removed the covers, checked the battery
terminals and ascertained that the clicking was
coming from the solenoid. If stuck, several
sharp knocks should have freed it up but no
such luck. What to do?
Whilst I am quite happy to tinker with my car
or other mechanical devices, I hate even
removing the covers off my aeroplane, as to me
this is the realm of experts. Just then the sole
other person at the airport, who was mowing
the grass, came past and I asked him if there
were any engineers in the area. He informed me
the closest was at Inverell. Fortunately the
phone worked and I rang my Bankstown service
organisation who could not suggest any quick
remedies other than those I had already tried
and informed me there were thunderstorms in
the Sydney area so there was no chance of
them mounting a rescue operation. (I later
learned one of them was prepared to drive - a
nine hour trip.)
So in desperation I rang Inverell only to be told
the boss was out and would not be back for 20
minutes. Half an hour later when I came to ring
back I realised I had run out of coins and
nothing would induce Telecom to connect me
except as reverse charge. Fortunately they
accepted the charges and listened to my story.
Well I could try shorting out the solenoid or I
could hand swing it. In any case if I paid for
the aircraft he could be there in 50 minutes but
he had sold his last 24 volt solenoid yesterday.
~
•I
I would not swing a prop unless my life
depended on it, particularly a three bladed one,
and I'd been told you could not start my
aircraft by hand swinging the prop anyway. In
any case, none of my passengers knew anything
about aircraft so who was to sit at the controls?
- not entirely necessary but a comfort if I'm to
do the swinging. So I told him to come over and
whilst I was waiting I got a screwdriver and
shorted out the solenoid terminals. One large
spark convinced me that I was right not
wanting to take the covers off!
Exactly 50 minutes later he arrived in a smart
looking tail dragger and apologised for not
telling me to switch the terminals over. He very
quickly narrowed the fault to the starter motor.
What was I to do? Put my passengers on a
commercial or drive them back to Sydney and
bring an engineer and a spare starter motor
back with me? Leave the aircraft where it was
until someone could fix it? Burn the aircraft
and collect the insurance?! All very costly and
time consuming and really no joke.
At this point he offered to hand swing the prop
but my spirits were at a low ebb and I pointed
out to him that I had to refuel at Armidale and
how would I get started again. To my surprise
he suggested that I fly to Inverell where he
would organise some fuel for me and then he
would start me again. Do such nice people
exist? It appears they do in Inverell. In any
case my spirits leapt and I immediately
accepted his offer. I was conscious of the
thunderstorms at Bankstown and that they
could come in later in the afternoon so without
further ado I loaded my passengers and he
swung the prop for me.
,
The 300 HP motor does not turn over easily and
just when it looked like a waste of time it
sprang into life amidst cheers from the
passengers, who had waited patiently for the
two hours all this had taken.
I was about to taxi when it struck me, what
about my checks!! For a pilot who is meticulous
about his checks on the ground and in the air I
was about to taxi out and take off. I radioed
my friend who had started his tail dragger and
told him to go ahead and then forced myself to
quieten down. The anxiety of the situation
together with the excitement of the moment
had been enough to negate the years of training
discipline that I had built up. Having reminded
myself I was a pilot first I settled down to do
my checks and departed shortly thereafter for
Inverell. I must confess I had expected more
trouble from Coffs Harbour when I informed
them that I had revised my flight plan via
Inverell due to mechanical problems but other
than ask for a time interval and whether I
would have any problems landing, they did not
worry me at all.
He was as good as his word and on landing at
Inverell he had the fuel ready. We refuelled and
discussed starting techniques with hot engines
- I decided to try the starter motor just in
case and believe it or not the gremlins had left
and it worked normally.
As we departed Inverell I felt my old self
having recovered from my lapse at Glen Innes,
but the day wasn't over. At Mount Sandon,
Sydney advised us of severe turbulence to the
south and west of Sydney then a little later
that Sydney was closed with thunderstorms and
then that Bankstown was closed but would
reopen soon. As we were still half an hour
away I decided that it would probably have all
passed by the time we got there. At Mount
McQuoid we were given a radar heading which
was to take us west of the thunderstorm but
my weather radar showed one directly in front
of me so large that almost the entire centre of
the screen was red. I asked for and was granted
a further detour to the west wondering if the
controller was aware he had given me a
heading towards the middle of the storm. They
brought me into Bankstown from the south and
although the airport was clear the storm was
passing it on its northern boundary.
Bankstown Tower informed me that as there
was no other traffic and that I could do a left
hand circuit for Runway 29. But half way along
the downwind leg he informed me of a sudden
wind shift and that I should do a 180 degrees
for a right hand circuit to Runway 11. That
was the last straw for the passengers. They had
been glued to the weather radar watching the
storm and could not believe their eyes. Now a
sudden turn-around in the circuit and a landing
into a 15 knot crosswind just capped off the
day. As darkness fell they all headed for the
bar and one for the telephone to relate how
lucky he was to be alive. The thunderstorm did
considerable damage in Sydney and particularly
in the Bankstown area, cutting power supplies
and unroofing buildings D
�r
Aviation Safety Digest
146
Aviation Safety Digest
146
Christmas
comes but once
a year ....
from a letter by Harvey Turner
N CHRISTMAS EVE, December 24th 1989,
a severe thunderstorm struck the Brisbane
region between 1600 and 1700 hours particularly causing significant damage at both
Archerfield and Redcliffe aerodromes. I
attended at Archerfield shortly after the storm
had passed to check my Flying Group's aircraft
and again the next day at Redcliffe after
receiving word of the severe damage to aircraft
that occurred there. There were some obvious
reasons why damage was so severe, and the
reason I am writing is to promote awareness
and discussion amongst the aviation
community.
At Archerfield (where our Grumman Tiger was
found unharmed and still chained securely to
good galvanised wire tie-downs) the following
was noted:
(1) Major damage caused by a parked DC-3
being pushed by the wind some 400 yards
through the general aviation aircraft
parking area where aircraft were secured to
the standard wires pegged across the grass
area in front of the Royal Queensland Aero
Club. The DC-3 clipped the tails of two aircraft before picking up a Cessna 182, breaking the wire tie-downs it was secured to,
and then demolishing that aircraft as both
became entangled in the next tier of tiedown wires. The force of their progress was
sufficient to pull out of the ground the large
concrete block at the end of the tie-down
wire and drag it some 10 feet horizontally
before the aircraft came to rest. Just as well
as it saved damage to more aircraft parked
in the line of travel.
What I considered significant was that the
DC-3 was not tied down and this certainly
seems to be normal procedure with any aircraft bigger in size than a Beechcraft Baron.
So there is a lesson to be learnt there and
noted by the likes of FAC who control the
major airports - ensure all aircraft are
properly tied down, big and small.
(2) The wire tie-downs pegged across the grass
at Archerfield have been there many years
and a lot of them are rusty and rotten. The
Cessna 182 mentioned above had good rope
tie-downs to the wire and it was the wire
O
t hat parted! So t here is another lesson for
all airport operators - ensure your tiedown wires are galvanised, in good condition and properly anchored.
(3) A Cessna 185 aircraft parked adjacent to
our Grumman Tiger had broken all three of
its rope tie-downs and very fortunately had
not run or been blown into other aircraft.
The ropes were of a substantial diameter
and synthetic, however they were powdery
and rotten from age and exposure to sunlight. That shows a degree of irresponsibility on the part of the owner - for the
sake of about $15 cost for new tie-down
ropes, he endangered his own and every
other nearby aircraft.
At Redcliffe, the storm destruction was more
concentrated and severe. Four aircraft were
up-ended and destroyed, and virtually every
aircraft on the field suffered damage to some
degree. There were unconfirmed reports that
vessels moored in the nearby Newport Marina
recorded wind gusts up to 180 km/ hr on digital
recording equipment.
What was significant at Redcliffe was that it
was high wing Cessnas that were up-ended, the low wing aircr aft that were securely tied
down surviving with varying lesser damage
caused by flying debris or Cessna aircraft that
had come adrift, colliding with the low wing
aircraft. In one case a Cessna 172 had pulled
the star picket stakes it was secured to clean
out of the ground and then been up-ended on
top of the Grumman Tiger next to it that was
securely tied down. Both aircraft appeared to
be writeoffs.
So it would appear that extra care must be
taken with high wing aircraft, and possibly the
use of screw in tie-down stakes in soft ground
encouraged. The standard star picket type stake
appears to be unsatisfactory in soft ground,
especially when subject to vertical forces.
Aircraft secured to common wire tie-downs had
all been pushed sideways by the wind, sliding
their individual tie-downs along the wire until
all the aircraft were in contact with each other
bunched at the end of the wires. More damage!
So maybe another lesson to be learnt - some
means of securing an aircraft's tie-down ropes
(or ideally chains) to the wires to that they cannot slide sideways.
The final cause of damage at Redcliffe was the
destruction of one hangar in a row of four similar hangars. The doors were of the folding type
that are pegged top and bottom at each fold.
The pegs were old and bent (or missing) and
the hangar doors just imploded and this inrush
of wind ripped off every sheet of iron from the
roof and end wall - some carried about 250
yards and one 20' length actually speared right
through a parked Musketeer. So the condition
of ha ngars or buildings can also be t he cause of
significant damage in these circumstances.
In summary it is apparent that most damage is
caused in these situations by aircraft (or
debr is) tha t break loose, running into, or fly ing
into other aircraft that may be very secu rely
and responsibly t ied down. Screw in a~chor
type stakes are very common in U.S.A. for use
by General Aviation air craft and would p robably be very useful her e in soft ground situations. Would it be appropriate for CAA or
some simila r body t o conduct compar ative tests
on the d ifferent types available and report
through the Aviation Safety Digest?
The Bureau of Meteorology, Qu eensland
R egional Office, kindly sent us the f ollowing
comm ents:
'The maximum gust recorded at the A rcherfield
Weather Service Office was 57 kt. A t that point
the autographi c recorder fai led and i t is possible that stronger squalls may have occurred
shortly afterwar ds. No observations were avai lable from R edcliffe aerodr ome but, following
the storm, investigations in that area r evealed
a reading of 100 kt had been observed on an
anemometer on a yacht m oor ed about 2 km east
of the aerodrome.
Although very sever e storms are, in any given
location, relatively inf requent, less sever e
activity does occur more regularly during summer mon ths, producing wind-squalls of the
order of 40-50 kt. In a recent survey, an average of more than fou r su ch storms p er year was
noted in the Greater Brisbane area. The p rime
characteristics of the squalls is the rapid
increase in wind speed in a short time. At
Archerfield on Christmas Eve 198 9 the mean
speed between 3 pm an d 3.50 pm was 12-18 kt;
in the following f ew minutes i t in creased rap idly to 5 7 kt.
Whi le thu nderstorms are less frequent ov er
southern Austr alia, strong squally winds m ay
occur with the passage of troughs or f ron ts and
sustain ed strong to gale force winds may be
experienced in association with intense pressure systems. '
Authority involvement in these matters is:
• requiring that any tie-down p oints fitt ed to
aircraft be properly stressed. Note: tie-downs
are not a certification requirem ent and the
CAA does not necessarily check the relevan t
stress analyses.
• informing aerodrome operators of the need to
provide light air craft tie-down facili ties.
• including recommended tie-clown procedures
as a subject in the 'Syllabus of Training for
Private Pilots '.
The CAA does n ot offer public comp arison
between commercial products; this might be
conducted more properly by your par ticular
Associati on or flying organisation. It is deemed
the owner/ operator's responsibili ty to secure
the air craft an d any damage resulting f r om
storms etc is then catered for by the insurance
company or, at worst, common law 0
�Aviation Safety Digest
If you are not eligible for a free issue, or if you would like additional copies of the Digest:-
146
Unauthorised
descent
Hobart
from ASD 2
T
ASMANIAN weather on the 14th of February was generally poor, and as no early
improvement was expected, one DC4
enroute Hobart and one CV.240 holding over
that city returned to Launceston. After the
Convair had set course for Launceston, Hobart
ATC suggested to Launceston Operations that a
DC3 at Launceston remain there instead of proceeding to Hobart, as it was unlikely that HB
weather would improve in the near future.
However, the captain of the DC3 elected to proceed to Hobart, and at OlOOZ reported over
Ross Homer at 5000 ft, giving his Hobart ETA
as 0123Z. Hobart weather was passed to the
aircraft and the captain was advised that the
aerodrome was closed to landings. A few minutes later, he was further advised that no clearance to descend below 4000 ft would be given
because of the prevailing weather conditions.
The aircraft arrived over Campania Homer at
0123Z and was cleared to descend to 4000 ft.
At 0127Z, the aircraft reported its position over
the Inner Marker at 4000 ft and was instructed
to hold at that altitude on the standard holding
flight path. However, some nine minutes lat er
the captain reported contact through a break in
the cloud and requested a clearance to make a
VFR approach. This was not granted, but at
0138Z the aircraft was sighted about eight
miles SE of the field below an overcast layer,
the base of which was estimated to be about
1 OOO ft. The day minimum for Hobart is 1 730 ft.
The captain advised that he intended to land
and landing instructions were then provided.
The landing was completed at 0141Z under fluctuating conditions that were still below the
landing minima.
The main point of this incident is that the captain of the DC3 deliberately disobeyed a valid
ATC instruction by making the unauthorised
descent.
As a result of the investigation into the occurrence, the captain's First Class Airline Transport Licence was suspended for a peFiod of four
months. The suspension did not affect his
capacity to hold a Third Class ATL.
Aggrieved by the decision, the captain applied
for an independent Appeal Board to be constituted to consider the suspension.
The Appeal Board [having considered the evidence] gave its decision to confirm the fourmonth suspension.
... a blast from the past indeed. Captains were
captains in those days, and some of them knew
far more than any old Air Traffic Controller D
Four
..
iSSU8S
$A 14.00
AVIATION SAFETY DIGEST reports incidents, recounts
stories, relays technical information, represents the pilot
and others involved in aviation, and, to the extent that it
falls short of being a legal document, reflects the viewpoint of the CAA.
We have noted previously that regulation alone may well
have been exhausted as a means of reducing accidents.
This is not to say the CAA is on autopilot - there are
moves afoot to make CARs, CAOs and subsidiary legislation more user-friendly (or at least, somewhat simpler).
1;nc1udingsur1acepostageJ
marginal conditions. Self-discipline, mechanical reliability
and the correct application of hard-gained expertise are
but the three leading links in the chain of circumstances
that define a truly successful flight.
The wide range of submissions that cross the editor's
desk are testimony that 'marginal conditions' cover practically everything. There are a million articles out there in
the real world, and a zillion incidents (99% of which you
wouldn't dream of putting your name to - that's OK,
we'll respect your desire for anonymity). So why not share
your hard-earned lessons? As I said, your story is unique!
Although an aviator will always benefit from reading about
another's brush with disaster, we are all fortified in the dili- To be part of this accumulated wisdom, those with an
interest in flying, be it as a professional or paid-for-bygence of our personal pursuit of safety by the knowledge
that there are a lot of fellow flyers who think twice - nay yourself, will do themselves a favour by reading the Digest
on a regular basis; if you do not obtain a free copy, the
three times even - before committing themselves (and
their passengers - never forget the pax) to operations in subscription form is, as they say, overleaf.
------------------------------------------~--
As the pilot-in command of a Cessna 182,
you are requested to carry a parachutist in the
RH control seat position. Two relatives of the
parachutist wish to travel as pax, to observe
the jump. The aircraft has an in-flight paradrop
door which is approved with a supplement
included in the Flight Manual. The passengers
are properly restrained in the rear seat. Can
this operation be conducted in accordance with
Civil Aviation Orders?
Q2 You are flying along in a Cessna 1 72 and
see on the ground beneath you another aircraft
that you identify as a Cessna 206. It is parked
near a shed on a cattle station. There appears
to be a well-cared-for airstrip with short grass,
white-painted tyres, windsock, and fresh tyre
marks from the runway to the parked aircraft.
On the roof of the nearby homestead is painted
in bold letters the name CABRAMATTA HOMESTEAD. You look in your ERSA, but the aerodrome is not listed.
Ql
Can you legally land your aircraft at this
aerodrome?
(Captain R C Winckel, Airways Surveyor (GA)
Q3 In a General Aviation Control Zone
(GAAP), what is the missed approach (goround) procedure?
(N Holden, Senior Tower Controller, Jandakot)
Q4 Where would you look to ascertain the
empty weight and empty weight CG position of
your light aircraft?
(a) Pilots Operating Handbook;
(b) Operations Manual;
(c) Approved Flight Manual; or
(d) Maintenance Release.
(Roy Scaife, AGM Safety R egulation, WA)
Q5 May an IFR flight be legally conducted at
night to a destination not served by a radio
navigation aid?
(Answers page 23)
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
G.P.0. Box 367
CANBERRA A.C.T. 2~01
Australia
I
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Aviation Safety Digest 146 / i
�r
Entry Form tor the Aviation Safety
Digest Photographic Competition
Dear Sir,
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details crre as follows:
Category of Entry: _
_ _ _ __
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_ _ _ _ _ Caption or Title:
Description of the Photograph cmd Theme (please identify any aircraft type): _ _ _ __ __ _ _ __
Name of Entrant:
Address: -
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"'Despite the clear intention of
the BOSO procedure, I am constantly
amazed by the number of pilots
who believe a BOSO notification
includes SOOOft (AOSO). We also
find the occasional smart-Alec who,
when asked for present altitude
BOSO for traffic, advises '4999 ft'.
Not in the spirit of BOSO... ?"
--------------
Phoneand/orFaxno. _ _____ __ _ _ _ __ _
I agree to be bound by the conditions of entry as described in the advertisement
Date:
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ENTRIES CLOSE: Last Mail
Friday, 4 April 1991
Results will be published in the
Spring edition of the Digest
TO: Photographic Competition
Aviation Safety Digest
Civil Aviation Authority
GPOBox367
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-~----------------------------------------------L--
Entry Form tor the Aviation Safety
Digest Photographic Competition
ARP
Dear Sir,
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details crre as follows:
Category of Entry: _ __ __
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!agree to be bound by the conditions of entry as described in the advertisement
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)
'
CURRENT STATUS
89/1
Amendments to CAO 20.7.IB Aeroplane
weight and perfonnance limitations
Advice to AAAC on future
progress at July meeting
89/3
Amendments to CAR 157 and CAO 20.7.4
- single engine
Complete
89/8
Follow on Review Reg 206
Letter to industry on
classification and licensing
28 June
90/2
Operational Control- Implementation of
Terrell Report
ARP responses assessed.
Further action delayed
pending discussion with
Civil Air.
- - -- - - -- -
Caption or Title:
SUBJECT
Date:
ENTRIES CLOSE: Last Mail
Friday, 4 April 1991
Results will be published in the
Spring edition of the Digest
Aviation Safety Digest 146 / v
�Noise isolating headsets
Meteorological information via Telecom's
Discovery system
,
Cockpit noise can reduce the effectiveness of aircraft communications, can cause
noise related fatigue and in some cases can damage the pilot's hearing. In recent
times, manufacturers of aircraft headsets have been improving the noise isolation
Telecom's Discovery system (formerly known as Viatel) now offers a range of
meteorological products, including:
of their products. These headsets are very effective in protecting the pilot's
• low-level area forecasts over SE Australia;
hearing from the aircraft noise in the cockpit and this is a desirable result.
• relevant weather warnings; and
There is, however, a possible down side to this protection.
Aircraft manufacturers are required by the aircraft certification rules to provide
• a selection ofTAFs and METARs within that area.
It is hoped to extend the system Australia-wide within twelve months. Further information
is available from:
warnings for such things as stall, undercarriage position, aircraft configuration
etc. for your protection.
Noise attenuating and noise cancelling headsets can in some circumstances
reduce the effectiveness of the cockpit aural warnings and other aural cues such
Discovery Telemarketing
(MEI'EX INFORMATION)
Freepost 20
GPO Box 188C
Melbourne 3001
phone 008 033 342
as abnonnal noises, which might give some warning of unusual operations. This
is particularly so at times of high stress, when aural cues need to be very obvious
in order to gain the pilot's attention.
Staff in the Head Office Avionics Section of Continuing Airworthiness in the
CAA feel that pilots who use these headsets should be aware of these possible
drawbacks and have some care in the way they use the headsets.
No regulatory action to limit the use of such headsets is being considered. The
responsibility for adequate communications in the cockpit and for responding to
the aural warnings remains with the pilot. However, owners or operators whose
pilots use this type of headset should, where practicable, give consideration to
wiring the aural warnings through the aircraft audio system.
The Australian Sport Aviation Confederation is offering a prize of
$500 for a new logo design. More info from:
PO Box 144
CURTIN ACT 2605
vi / Aviation Safety Digest 146
Aviation Safety Digest 146 / vii
�AERONAUTICAL INFORMATION SERVICE AUSTRALIA
r
NOTICE
Anatomy of Safety
Regulation SA/NT
CURRENT DOCUMENTATION AND
PLANNED NEXT ISSUE
Current Issue
Document
#
~8J Field Office Forum
Planned Next Issue
#
Thomas Charles Russell, Examiner of Airmen, GA
DAP(E)
23-8-90
18-10-90
DAP(W)
26-7-90
20-9-90
INTERNATIONAL
AGAO- 1-2
31-5-90
30-5-91
AIP (book)
23-8-90
13-12-90
VFG (book)
23-8-90
13-12-90
AIP/MAP
23-8-90
13-12-90
VFG/MAP
23-8-90
13-12-90
DAH
23-8-90
13-12-90
ERSA
23-8-90
13-12-90
#Dates quoted are effective dates
NOTE : NOTAM CLASS I AND CLASS II ARE TO BE READ IN
CONJUNCTION WITH THE ABOVE DOCUMENTS
ISSUE: 11
DATE: 23 AUG 1990
viii/ Aviation Safety Digest 146
S USUAL, when someone asks what do you
do and what are the problems associated
with the job one tends to exaggerate
slightly. When, on the other hand, there is a
request that it be put it into an article for all to
see, most examiners find pressing business
elsewhere.
When the editor of this publication asked my
Leader of Men, Barry Lodge (Assistant General
Manager, Safety Regulation, SA/ NT) to write
about what we do, I was slower than my p eers.
Then came the problem - what t o write
about?, nothing long, you understand, something simple, five or six thousand words,
Bloggs - we have faith in you!
After much soul searching, the odd bit of bribery etc, it became fairly obvious that a major
difference in our Region compared to the others
is 'The tyranny of distance'. High sounding
words, but they truly describe our basic problem. SA/ NT has an enormous area to cover,
with major centres separated by immense distances. The variety of life styles, ranging from
southern temperate areas, then through the Red
Centre and right up to the northern tropical
areas, reflect the enormity of the Safety Regulation task.
In any short set of days, the range of tasks
could cover sophisticated airline-type aircraft
checks, then through to Alice with scenic flights
to the Olgas, and possibly on to Darwin with it s
companies servicing t he far-flung and isolated
Aboriginal and mining communities. During this
small space of time, our decisions and judgements must reflect the safety standards
required as well as displaying and using our
knowledge of that particular area.
Adelaide, as an example, would have a range of
tasks checking several large Supplementary airline companies whose aircraft vary from light
twins to sophisticated jets. In the same area a
host of flying schools and charter organisations
also exist, again with a myriad aircraft types.
All these companies exist in a relatively up t o
date area, with availability of latest technology,
and instant access to specialist CAA staff.
A
As we continue northwards , not only does t he
scenery change, but also the type of operation.
With floods throughout the region, aviation is a
lifeline. These activities range from outback
mailing runs to tour operators and the everready Flying Doctor. Each operation has its
own special problems inherent in the harsh and
unforgiving terrain . The simple lack of ready
access to parts, technology and social amenit ies
give rise to problems that Safety Regulation
staff must understand, cope with and be able to
advise on in a practical and safe manner.
According to some people, the CAA is not
always right; however, the main object iv e is to
understand problems peculiar to the remot e
areas and come up with decisions that in reality
we can justify and live with.
Last but not least, the tropics . Surprising how
many staff decide that Darwin needs a visit or
four during the cold and bleak months of a
southern winter. Operational necessity, I
believe is the term used most often. The t ropics
introduces its own special problems for companies and the workforce. The remoteness of
Darwin from the main centres of t he south and
the sense of isolation can play hav oc with the
idea of keeping staff in the long term. Some
people just p lain hate sun 365 days a year with
little or no temperature variation. Aircraft
parts, particularly radios, do not like humidity
and tend to collapse, rest, give up etc usually
when you need the aircraft (ie right now). The
lack of weather makes the recency requirements for instrument rat ing holders difficult to
arrange. In some cases special training flights
must be conducted; this affects the cost structure of any company.
Everything considered, the region offers a challen ge to all of us. The distances involv ed, the
different types of people, the different problems, both social and professional, combine to
make life really interesting. It is a compliment
to all SA/ NT Field Office staff that on the
whole we cope and have good rapport with
other sections of our diverse industry. The compliment is enhanced when it is realised that for
our organisation 'safety' is a byword, not a
short-lived economic gain for some. Frankly, we
all realise that the lessons of the past were
gained through exposure to the harsh realit y of
aircraft accidents. The CAA (as a Government
Business Enterprise) and aircraft operators a re
now all in the same indust ry, and it is t o our
collect ive credit that t hings work so well for us
in SA/ NT D
�Aviation Safety Digest
146
Accident
response
Embraer EMB-110, 22 November 1989
The flight from Mount Isa had been conducted
in rain and cloud. At 5000 ft during the
descent, the pilot became visual with the runway lights and the nearby goldmine. The runway was overflown, and it was noted that the
windsock was showing no significant wind. During the circuit for landing on runway 21,
increasing rain and cloud as noticed on
downwind, and on left base the pilot experienced heavy rain and strong wind gusts. The
pilot turned the windscreen wipers on but they
were not clearing the windscreen effectively.
Forward visibility was significantly reduced,
and on final approach the pilot was having difficulty keeping the aircraft aligned with the
runway due to the turbulence and wind gusts.
He elected to go around and carry out another
circuit. During the next circuit the conditions
had not improved, and the pilot again decided
to go around, as it had become increasingly difficult to maintain runway alignment. As the
go-around was commenced the pilot heard a
loud bang and realised the aircraft had struck
trees. The aircraft was climbed and the Kidston
NDB approach procedure was carried out. The
pilot became visual at 2900 ft and carried a circuit and landing on runway 03 . (Kidston is
1620 ft above sea level).
After shutdown the aircraft was inspected and
was found to have sustained tree impact damage to the left inboard leading edge, the left
propeller, and the left horizontal stabiliser. The
pilot believes the tree strike occurred as a
result of downdraft associated with the storms
in the immediate area.
The Kidston aerodrome is established according
to the provisions of AIP AGA-6 and although
approved for the night operation being conducted, it does not have an approach guidance
lighting system.
The aerodrome does not have any other ground
lighting in the immediate vicinity other than
the runway lights, and this may lead to the
pilot having a false perception of height and
runway perspective. It is considered that the
lack of approach guidance, combined with the
prevailing weather conditions, contributed significantly to the cause of this accident. There is
rising terrain on the approaches to runway 21.
Aviation Safety Digest
146
The pilot reported that he was having difficulty
with forward visibility due to ineffective windscreen wipers. The effect of the heavy rain on
aircraft windshields may lead to a number of
visual errors. One effect is to make objects
appear to be lower in relation to the aircraft
than they actually are. Whilst it is difficult to
estimate the magnitude of the error, the
elements were present in this accident, and may
have given the pilot a false impression of his
height in relation to the runway lights.
The following factors were considered relevant
to the development of the accident:
1. Weather associated with thunderstorms in
the local area.
2. The aerodrome is not equipped with a
serviceable runway approach lighting
system.
3. During a visual approach the p ilot encountered excessive crosswind, reduced visibility
and turbulence.
4. The aircraft struck a tree on the approach to
runway 21, due to the inability or' the pilot
to appreciate the proximity of the aircraft to
the terrain on final approach.
5. The aircraft windscreen wipers were not
working efficiently.
6. Excessive rain on the windscreen may have
caused a visual error and contributed to the
pilot flying the aircraft into an undershoot
situation.
BAS! recommendation
The Civil Aviation Authority should immediately review the suitability of Kidston aerodrome for night operations. The aerodrome was
surveyed in February 1989 preparatory to the
installation of approach lighting. The system
was installed but was not commissioned due to
problems with excessive light intensity.
The Civil Aviation Authority should assess the
need to make approach guidance lighting a
requirement for night operations at Kidston.
Socata MSTB20, 10 October 1989
The aircraft was being flown on an air test
after a previous flight incurred a defect with
the emergency gear extension system. The test
was conducted in the Bankstown training area
and all gear extensions both normal and emergency worked correctly. On return to Bankstown
for landing on runway 29 Right, the landing
gear was lowered on downwind in the circuit
a nd the normal three green indication was
noted. The approach and landing was normal
until just as the nosewheel touched the runway
the right maingear collapsed and the aircraft
skidded to a halt to the right of the centreline.
Subsequent investigation revealed the right
maingear jury strut pin had separated from the
attach bracket on the rear spar. The strut pin
retaining circlip has been incorrectly fitted during the last installation.
Improper maintenance was considered relevant
to the development of the incident:
BAS! recommendation
The jury strut spar bracket P /N
TB20.43.013.000 L/H or .001 R/H is supplied as
an assembly ex-factory consisting of the
bracket and two bushes. Unless the bushes are
fully inserted in the bracket the locking characteristics of the circlip on the pin may be
compromised.
The jury strut pin retaining circlip cannot be
inspected in situ on MSTB20 aircraft.
It is therefore recommended that the Civil A viation Authority consider notification to owners
and operators of MSTB20 aircraft that a defect
may exist and detail procedures to check the
integrity of the circlip and jury strut pin.
runway. Inspection of the aircraft failed to find
any pre-existing defects or abnormalities which
were contributory to this accident.
Flight test evaluation of the stall characteristics
of this model aircraft had indicated that it only
marginally achieves the certification requirements, and is difficult to control in all but ideal
stall conditions.
It is considered probable that the attention of
the pilot was diverted from the operation of the
aircraft due to the failure of the landing gear to
retract and the cockpit workload and associated
anxiety following the heavy landing. Medical
evidence indicated that both occupants had
been holding their respective control columns at
the time of impact. What effect this may have
had on the development of the accident was not
established.
·The reason why the aircraft entered an abnormal flight manoeuvre at an altitude from which
the pilot was unable to recover could not be
determined.
Significant factors.
Mooney M20J, 18 June 1989
The pilot had recently been endorsed to fly
retractable undercarriage and constant speed
propeller aircraft, and h ad accumulated six
hours on this aircraft type. When the aircraft
arrived in the circuit area the wind was westerly at 10-15 kt gusting to 20 kt. The pilot
elected to conduct an approach to runway 23,
although an into wind runway was available.
The reason for this decision was not established. The pilot carried out a go-round from
his initial approach. Following the second
approach to the same runway the a ircraft
touched down very heavily. Structural damage
to the aircraft was sustained, with the left main
landing gear door and retraction rod-end bearing being detached from the aircraft. After
bouncing on the runway the aircraft became
airborne again, and with the landing gear down
and hanging free, it was observed to commence
anoth er left hand circuit. At an estimated
height of 200-300 ft, the a ircraft turned on to a
low level downwind leg with an increasing nose
high attitude. It then was observed to roll into
a spiral dive manoeuvre from which it failed to
recover.
The on-site investigation revealed that the aircraft had impacted soft waterlogged ground,
outside the aerodrome boundary, in a near vertical attitude. Rear fuselage distortion was consistent with the aircraft having been rolling
a bout the longitudinal axis at the time of
impact. Ground impact had reduced the cockpit
area to non-survivable dimensions. The engine
and propeller, which were buried in the soft
ground beneath th e cockpit area showed no evidence to indicate that the propeller had struck
the ground during the heavy landing on the
The following factors were considered relevant
to the development of the accident:
1. The pilot elected to carry out an approach in
gusty crosswind conditions when a more
suitable runway was available.
2. The pilot did not maintain a stabilized
approach to land, possibly because of the
turbulent conditions and/or his lack of familiarity with the aircraft.
3. Heavy landing.
4. Following the heavy landing the pilot
encountered unforeseen circumstances
beyond his capability.
5. The pilot's attention was probably distracted
from the operation of the aircraft.
6. Loss of control with insufficient h eight to
effect a recovery.
7. Possible inadequate training on the specific
aircraft type, particularly with regard to
slow speed handling and stalling
characteristics.
BAS! recommendations
That the Civil Aviation Authority consider
removing this model of aircraft from the group
endorsement for single engine, retractable
undercarriage and constant speed aircraft in
favour of a specific endorsement which requires
additional flying training in stall and spin
recovery techniques.
That the Civil Aviation Authority provide the
industry with advisory information concerning
stall warning strips and switches, their positioning, flight testing and procedures for setting and adjusting.
Response to these BAS! recommendations is
still under consideration by the Authority 0
�Aviation Safety Digest
146
A LAST-MINUTE RUSH
I hold 3:n Unrestricted private licence, day VFR
only, with 200 hours, a third of which are in
command. Whilst on holiday in my home town
of. Albany, I flew to Bunbury to pick up a
fnend and return home via the southwest coast
armed with a video camera.
'
I planned to fly a Cessna 1 72 directly to
Bunbury - a one and a half hour trip. The
return trip was to be three legs: via the coast to
Margaret River; direct to a hamlet on the coast
west of Albany, then coastal to Albany.
I p lanned for nil wind, partly for ease of flightplann.ing. and partly to ensure that I got some
practice m nav techniques. The forecast for the
day was fine and beaut, with a light southeasterly, which meant a tailwind to Bunbury.
The trip to Bunbury was near-perfect, and was
followed by a couple of hours in enjoyable company. I obtained an updated forecast 1 which
indicated that the SE wind would be about 20
~nots on the way home. No drama, I thought,
I ve planned to arrive home by 1930 and last
light isn't until 1954. Plenty of fudg~ factor in
that. Mistake #l!
At the airfield, I allowed goodbyes and a guided
tour ?f the aircraft to delay our departure by
15 minutes. Mistake #2.
We got airborne at 1720, with 5 hours endurance and a (nil wind) ETA of 1930. We headed
for the coast for that Mecca of WA surfing
Marg River. The beaches along the way we~e
captured on film then we were at our first
tur!ling-point, 5 minutes later than my initial
es.t1mate. The first touch of concern entered my
mmd. Our next fix caused me to add another 5
minutes to our next estimate: sure enough we
were 5 min behind schedule at the second turn.
I'd come to my senses by this t ime and realised
we wouldn't be home by last light unless I did
something constructive. We descended from
3500 to 1500 to reduce the headwind
component, accelerated to ll O kt and diverted
directly to home base. Navigation was easy keep the coast on the right and follow the ADF.
My friend remarked that he couldn't wait for
the sun to set, so that he could catch it on film.
He was in~ormed that there was no hurry at a ll
for that big orange ball of fire to disappear! We
maintained ll 0 kt IAS - as fast as the little
beast. would go - and were advised by FS that
last light was 1954: a fact of which I was
already acutely aware. The PAL was activated
we were overhead Albany by 1944 and were o~
the ground a couple of minutes later having cut
it as fine as ever I would want.
'
1
In retrospect, I should have taken charge a bit
more forcefully at the airport and told my passenger that I'd be airborne at 1700 with or
without him. More important, I sh ould have dug
out the nav computer and calculated some new
ETis based on the forecast wind. It's all well
and good to plan for nil wind, but it's still
vitally important to have a good look at the
forecast, work out as accurately as possible the
effect the weather and wind is likely to have on
y~ur flight, and fly accordingly. It was only a
mmor drama, but one which could easily have
been avoided by more careful preparation.
Kevin Lathbury
1
There is not a lot to add to this cautionary tale;
perhaps only to say that to ignore the
headwind component is to guarantee yourself
ex~ra workl~a:1 in the air - one of the very
things that 'flight-planning' is supposed to
relieve.
Dear Sir,
In ASD 139 pages 8 and 9, the question was
again raised of overwater flight and the use of
lifejackets.
L~aving aside the problems of exiting the
aircr~ft and avoiding hypothermia, the plain
fact is that most available lifejackets are
unsuitable for the prescribed use in light
aircraft. They are uncomfortable, they get in
the way and are prone to damage from
repeated packing, wearing and subsequent
repacking.
I ~elieve. the CAA should look into this problem
"'."1th a view t? .recommending a jacket along the
lmes of the IDlhtary pattern ie a fabric vest
with an enclosed and protected inflatable collar.
Such vests can be comfortably worn by pilots,
and they have the bonus of pockets for pens
and other impedimenta (particularly the VSB).
When I was in UK and involved in regular
cross-channel flying I had the use of one of
these 'Mae Wests' and found it by far the best
solution available.
Gordon R.W.Davies
We asked Martin Aubury, our Principal
Engineer (Structures) for comment here. He
said that while the Authority whole-heartedly
supports the thrust of Gordon's letter we are
charged with the setting of standard; and
cannot recommend particular configurations.
Jt:!artin added that readers may also be
interested to know that lifejackets from
overseas meeting the current US FAA and UK
CAA standards are now automatically
acceptable in Australia (CAO 103.13, Issue 6
contains details).
Dear Sir,
Although I have held a CPL and IR for more
than twenty years, all my flying is of a business and private nature, and most has been in
the South-East.
The aeroplanes I fly (mostly my own Cessna
210) are usually not fitted with de-icing equipment and so the 'freezing-level' line in the forecast often receives a second glance. If it is at a
critical level related to the lowest safe altitudes
I make further enquiries. Sunday 16 July and
Mon~~Y 17 July were typical examples of such
cond1t1ons, and many other similar occasions.
S~nday 16 July I had been in Sydney for the
mght and needed to get back to a property near
Rugby before lunch. A morning call to
Bankstown elicited a forecast of low cloud and
a freezing level of 4000 - 6000. Since the lowest safe was 4700 (via Shelleys), I asked
further questions, but the only information I
received had been garnered from balloon flights
over Nowra at 3.30 am, and there were no
'actual' reports available for the freezing level
or icing conditions.
I proceeded with the flight on the basis that if
the freezing level was 4000 I could get back
into Bankstown or Sydney; I would find this
out on initial climb, before reaching the high
country. In practice, the freezing level was
around 6500 and there were no problems.
Monday 17 July I had to get back to Sydney
and on a cloudy, rainy morning rang
'
Bankstown, told the Met. officer I was IFR to
Bankstown and asked for the forecast. The
answer included information on the wind and
the assertion that there was 'no problem this
side of the ranges'. Since ceiling and visibility
were at minimums where I was 1 I asked for the
freezing level. The answer was 3000 - 4000
(well below lowest safe), but if I hadn't specifically asked I wouldn't have been told!
After. a great ?eal of further enquiry the only
hard mformat10n available was from the balloons at Nowra and Wagga (again at 0330);
there were no 'actuals' for freezing level or
icing. A look at the thermometer on the front
verandah suggested the freezing level would be
above 5000, and I was able to satisfy myself
that a low level escape route to Cowra was
available: this was essential, since I would be in
the murk by 3500 ft. In the event there was no
icing at 5000 - the freezing levei would have
been about 5500.
The reason for this letter and its summary of
two recent flights is that the system could easily be changed to IMPROVE INFORMATION ON
FREEZING LEVELS AND ICING CONDITIONS.
On both of these mornings perhaps fifty or
more aircraft would have landed and taken off
in Area 21 (forecast area). The majority of
th~se would have operated through the critical
a~t1t~?es at speeds which would not give rise to
s1gruf1cant friction heating effect, and the pilots
could have supplied icing information even if
their OAT gauges were not particulariy accurate. On both these mornings there was not a
single 'actual' available from either Sydney or
Bankstown.
In my e~perience, freezing levels don't change
very qmckly except in well-defined situations.
Surely the FIS system could obtain actual
reports of levels when forecasts indicate they
are below most of the Lowest Safe Altitudes.
Light aircraft IFR flights must still cope with
two weather situations that are 'no go': embedded thunderstorms and icing. The former are
hard to forecast and situations change rapidly
so '.act ua1s , may not necessarily be of much '
assistance, but freezing level and icing actuals
would be of great value.
Please, on behalf of many GA IFR operations
~~uld we have some 'actual' freezing level and
icmg reports, perhaps tacked on to the 'critical
locations' part of the forecast?
Geoffrey F J Ashton
This long letter is printed in full because it not
only addresses an area of general concern but
it contains pointers to the solution, or am~lior
ation, of the pilot's problem. Two main arguments apply:
First, if you are going to fly single-engine JFR
regularly, with neither radar nor de-icing
capa~ili.ty, survival depends upon an approach
to aviation as professional and intelligent as is
d_em~nstrated by this correspondent. It's your
life: if you don't know, ask. That's why you
have underg?ne meticulous training - in
order to equip you to cope in such an
unforgivir:g ~nvironment. This is pointed up by
the peculiarity of Australian climate - we
have nine or ten months of (it seems) 8/8 blue
with freezing levels > 8000 ft. When the
'
'we°:ther' finally arrives, we'd better be ready
for it.
Second, have a look again at AIP MET-0-9, para
6.5.2, or RAC/ OPS-1-83 para 3.5l or even VFG
40.8. It's there, in black and white. Basic
airmanship, not to mention mere good
manners, should ensure that you let others
kn?w about significant weather (or indeed any~hing unusual that might affect flight safety). Is
it really true that none of us ever send SHORT
AIREPS? On the other hand, how often have you
heard such a message being broadcast? Perhaps
the solution is in our own hands and, rather
than expecting 'Big Brother' to arrange it all
we really should be diligent in helping each oth~r.
Just a thought...
�I
I .
"' .;,
~hink
The USAF Flying Safety Magazine of March
about it: weather ~adar keeJ!S yott O'IJt of
troUble, while you are outside. To rely on~he
radar to get you out of trouble one.e you are in
tff' can be very counterpr-0ductwe
J 990 r.eliJ,tes wfiat coutd happen, after q, light· ,.
ning strike. A 'Well done Award' ha.s been pre- , .
sentiJd to. Ca'Rtam Curtis L. Cook, of the 388tw ·.~~,.
~n;radar·equipped air.er.aft oi: .~ftcr;aft with
Tactical Fighter Wing, Hill AFB, Utah,'lor tkm'
bit of airma.nship and determination: >·w. "
- -
flown
~
~
.
· - inoperable radar .should not be
'into
known or forecast area&?of thnnciet~torms
·ifi\1ess weather conditio.ns will allow vi6ual ,separation from cloud.
""'
;t
in t;oday's tight.Air Traffi~Control environ-
~
ment, fue.optitms forlaiterati-Otf of J;tack may be
·atmirushed, and it fakes s,P~ct~r eff-0.r~ to av-Oid "
., . risk
o.f' a lightning strike-;;Altho'ugh afreraft
'*'
_.
- - '""'
Jgn and ~structio.q have' led -tQ;?redOCed
o,tential for lightning damageglie~mosteffective approach to lightning is/ to.av6Jd ·a reas <>f
~ospheric electrical a.cti;r,jt}~f a,t aJ:l .possible.
Captai~ Cook's?F-1{)' wai?fsever~ly dam~ged.
B9th external fuel :fan.M exploded, ~lie left one
:cataStroP,hlcally, damaging -t_Ite left wing, the
TJte .bottom line is that ~w.e. ~ave :n<>' requirement
for flying iIJ.to thunde~Qrms or t&fly for
left side of t!t~ !l!s~lage~ a11f1,.thf tall .s<tcli-On -Ot:
the aircraft. In addition, aU of his primary
extended periods in areas of high potential for
flight control and navigation instruments failed
.lightning strike at or near fr~ezingJevel. .
including his ajrspeed,;:attitlide, heading indicator~ and h~ head-up display.
It is particularly important, if yoii nave flown
in conditions of ambient electrical activity (i.e.
iri :or near CB),_toe carry out an even more
As a result; (;aptain.Cook found himself flying
qieticulous after-flight inspection~ looking in
in clouds inan F·f6...with signiffoant structural
pm-ticular for small burn-holes in radomes, prodamage and with only a ~andbyattitfide indipeller trailing edges and extremities of the
cator and the altimeter fo"use for instrument
wings and empennage. Don't forget that lighfreferen~es. 'DeSpite the dangerofis situation.in
niqg affects not only the 'obvious' parts of ari
which he'fo\lnd fiimself; Captairi Cook main.,
aircraft - compass system, radios and
tai.Jlechait:.craft C-Ontrol:a:nd informed the arrival
airframe - but also the propeller and engine,
g:round controller ·of the emergency and his
which can be key areas for subse<;iuent failure
downed wipgman."'
,
·
iMhey are not !J!spected. A cdllapsed bearing in
a turbo .p rop propeller or reduction gearbox
cou\d have disastrous results,.-Or at the very
Hezskilifiifly 1descended untii 'J:le;wa& b~-0w;the
least .an .eXtremely expensivof! engine overhaul
clouds and could use~vfsuat references:ito"lniin·
.after the metafgoes through the. oil system.
taill flttitll,de co;trol, 1'<Ieit1 he,- eoorJinated for ·
another aif.craft tb 19fn him, and usirlg·airspeed
ref,erences from the chase aircraft; performed a
controlfahility check to dete
ne if he,c-0u1a
saf~ly -1
ls; crippled j~t,_ ~
...
I
~
-
· Tempera.tme.dist,ributiol'.t most suitl!-ble for · ·
lightning 's,1tikes is between :} S degrees and -S
degtees C. / £he freezing zone m ,a nqp stormy
i;ain rlg:lili 1s a partieulprfy ef~ctric~jly v-0latile
regi9n. S<mte rombinati~ of tlte:f Qll0:wing
· w;~at:twr phel}Om~na ~p:.raetors. co~stently
present wl;J:~n aJigbtning s,trike4 oc.curs. ·
• 'Uustable'fa}r, stationary front,·c-Old froh~-0r
;gquaH Jirte
:. withina"d-0ud
·
x
.
~
•
• air temperature near zero degrees C
• St Elmo•s fire 'ill
• "
·~ • turbulence
~
vj)
Dissipated
,,
thtndeisto~ean .still p.rodlice
·» .•
-:3-
.ri
<•
0
-
I
. i
and
The pr.ofessian_a l skill.
airmanship "aispla:yeO,;..by'iCaptain CoQk saved the loss of a valuable
combat aircraft aJ(assist~d' in the qu'i!}k ~ .,
recov~y of
irreplaceable wingman. :WELL
DONE!
an
�Aviation Safety Digest
146
Trial by fire
Pilot contribution by David Lyons
M
OST PILOTS do, at some time, think about
the possibility of a fire in flight, and they
wonder how they would react, how well
their training would sustain them, and if their
luck would hold.
On the l3th of August last year I found myself the
pilot-in-command of an aircraft which h ad lost
half its power and t he cabin of which was rapidly
filling with smoke. The terrain was less than 2000
feet below and our rate of descent was close to
1700 feet per minute. I had very little time to
make some critical decisions.
I had decided to take my young son on a skiing
holiday, and as the forecast was acceptable I
elected to fly to Cooma in our plane where an
elder son would meet us and drive us to a ski-resort.
Our aircraft was a Cessna 336, just one hour out
of an extensive and expensive major inspection.
For those who are not familiar with this type I
shall briefly expand upon its details. The 336 was
the first of the Cessna centre-line thrust series of
aircraft. It has two 210 hp engines, one at the
front of the cabin and one at the rear. Unlike its
off-shoot the 337, its wheels do not retract. With
one engine out, it behaves well and has a rate of
climb far exceeding its rivals. It is a simple aircraft to fly. I had deliberately chosen this aircraft
because of this. I'm getting older and very conscious of the possible effects of aging on my flying
performance. I didn't want to have to rely on fast
reflexes or a complex knowledge of aircraft systems or performance in an emergency. As most of
my flying is out of bush strips I wanted rugged
gear and I was willing to sacrifice speed for the
certainty of a set of wheels down and locked. The
336 is a twin for mug pilots. I didn't want to be
tested by a more difficult aircraft in case my
skills would not cope. In near a quarter of a century of flying I've flown a bit over two thousand
hours, pottering about the country, the inland and
the islands, keeping myself out of trouble. So I'm
an average pilot, no hot shot.
Aviation Safety Digest
146
On the day we departed for the snow I had
obtained a weather forecast for the route and
spent the morning packing and preparing the aircraft. Having flown many hours cross-country on
\
single-engined aircraft I still gave a lot of thought ~
to survival gear, consciously thinking of the ter.
rain we were to fly over. I ensured we had water,
first aid, food and sleeping bags. As I put new
matches into the tool box my young son asked
why. Not wishing to alarm him I merely replied
~
they were there if we ever needed to make a fire. ~
·
Similarly I secured the skis and cases, making sure
there was soft luggage on top for my passenger to
.
pack around himself in the case of a forced landing. Why would anyone contemplate a forced landing in a twin?
We departed our coastal property after lunch.
Cooma was two hours away. The trip was
uneventful after we skirted some coastal weather
and the hazards of the busy Bankstown training
area. The cloud cleared by Mittagong and at Lake
Bathurst I received a clearance at 5000 feet to
Captain's Flat. I was aware that this level gave us
minimal terrain clearance at some points but the
winds were most favourable and we had two
engines anyway.
Abeam Canberra I thought I smelt a whiff of
something hot, then it was gone. I automatically
checked temperatures and pressures, there was
nothing amiss there, and I moved on to the fuel
quantities, and noted we h ad used less than half
our tankage. Cooma was about 20 minutes away.
Suddenly the aircraft lost power. I firewalled the
six levers without thinking, as much in hope of
recovery as to ensure that we would lose no
precious altitude, and headed towards the sun, to
where the ADFs indicated Canberra to be.
At this point I became aware of TWO different
aspects of myself. There was Body who flew
reflexively, who only made decisions on the basis
of instinct and experience, who could do little
thinking and could barely read a number. Then
there was Mind, who liked to think a problem
through, using all he could remember from study
and training. And somewhere between was me,
watching this pair of clowns.
It was Body who had firewalled the levers and
had headed the aircraft into the sun. Mind st arted
to protest, debating the inconvenience if we didn't
land at Cooma. It was then my son pointed to the
expanding billow of smoke slowly filling the cabin.
Suddenly the nature of the problem changed from
They kept vectoring me until eventually I could
an expensive inconvenience to that of a lifesee the runway, just a mile or so away. A military
threatening emergency. Body knew the rear engine . helicopter tailed us in and confirmed that the fire
was out. Three fire engines waited as we landed.
had the problem and proceeded to close it down,
feather and secure. Mind warned that we must go
The seriousness of the damage to the aircraft was
through the proper procedure and identify and
not apparent to me from within. Only when the
confirm before closing down. Mind directed Body
firemen requested that I allow them to inspect the
to look at the fuel flow meters, to look at the
holes burnt in the cowling and lower fuselage, did
tachometer and establish the failed engine from
I become aware of the extent and fierceness of the
the data provided. Body looked. Where was the
fire . An examination indicated that the exhaust
fuel flow gauge? Which needle was which? Mind
pipe had had a piece separated from it. The
started to explain, but Body had the smoke to
ducted air had converted this into a blow torch
guide him and the funny little fish-tailing effect
which had melted aluminium, buckled the steel
t hat happens on a 336 when the air is fighting the
firewall, and burnt out much electrical wiring and
rear prop; he feathered and secured the rear
the fuel line.
engine anyway. The fish-tailing ceased.
I called Canberra and announced our problem.
Canberra quickly replied giving a heading to fly
and a distance to go for Canberra. That was great,
no silly questions, just the basic help that Body
needed. My next observation was that we were
losing height rapidly and I knew this shouldn't be
so, Clive Cessna didn't lie. We could fly on one.
But Body had decided before Mind that we had to
get down and vacate the aircraft and had already
reduced the power.
Mind was absolutely furious about this and proceeded to mention some of the things that Body
should have done first but Body pointed out that
it didn't matter very much and that if that fire
was still going (smoke was still there) we should
land very quickly in the nearest paddock and then
vacate the aircraft. Although the fire was away
from the tanks and spars I concurred. I radioed
my changed intention to Canberra and again
appreciated their simple acceptance of my change.
At this point the clowns united and I took over
again. Down below was a valley but there were
some paddocks which looked possible, but coming
up very quickly. The 336 glides like a cast-iron
bath tub so I selected a field which was close and
had its length into wind. I crabbed an angling base
and turned onto a short final. Then I noticed the
cattle. Base again. The next field was similar but
a bit wet looking. The last was okay and rather up
hill, maybe it was a thousand feet long. As we
were very close in I rolled out all t he flap and
watched completely confident, as the plane stood
on its nose and sank down at about 70 knots. I
KNEW we'd make a decent landing.
With fully ten seconds to go Mind mentioned the
smoke had cleared and we should continue on
with the front engine to Canberra. Experimentally
I moved the throttle and the front engine roared
into life and we climbed up from the paddock. I
announced to Canberra that we had changed our
plans again and now intended to fly on to
Canberra. Again they gave me a heading and a
distance to fly. That was most comforting. But
again I had a problem, the aircraft had stopped
climbing. It was mushing along at 50 knots and I
had to plan terrain avoidance, giving due consideration to wind direction in the turn. Suddenly it
struck me, I. hadn't cleaned up the flap. Flaps up,
the plane climbed at over 300 feet per minute and
cruised at around 95 knots. It was only a matter
of finding Canberra. The tower gave me a heading
to steer to intercept the runway, but because of
the nose up attitude and the fact I was flying
directly into the sun I still couldn't see the field.
I learnt rather a lot from that experience and I'd
made a few mistakes. The Hot Shots will learn
nothing from my experience but others might.
My mistakes:
1. Maybe I should have planned at a higher altitude to give my aging mind and body a greater
chance to do the right things in an emergency.
2. I didn't send out a Mayday call. (It proved
unnecessary but procedure should be followed.)
3. Despite the preflight planning I didn't give a
preflight briefing to my small passenger, nor
did I attempt this during the emergency. This I
will always do in future: time was very very
short up there.
4. Not cleaning up the flap on the go-around was
inexcusable, even for the few seconds involved.
In my last biennial flight review (completed
only a few weeks before this incident) I had
elected to go through all 'the hoops' at night.
The one thing I didn't do was a single engined
go-around and I don't normally take off with
flaps as I know then I don't have to clean up to
achieve the best single engined rate of climb in
the event of an engine failure.
I learnt a few other things too, that day:
1. Quite simply, I was too busy solving problems
to panic or dwell on the outcome. Generally my
training did stand up quite well, although I was
slow to clean up on the go-around.
2. My experience in landing aircraft in confined
areas and from unusually steep attitudes gave
me great confidence for the forced landing. Forget the 3% gradient stuff!
3. The time my first instructor spent flying me
around a tree in a paddock to d~monstrate the
effect of wind on a turn was appreciated once
again.
4. I appreciated the controller's response very
much. There were no silly questions to answer,
just the helpful information. The practice of
telling a mug pilot which heading to fly is far
better than giving the relation of the pilot's
position to the field.
5. I had difficulty sleeping that night, I kept
thinking how lucky I was that I had chosen an
aircraft so docile in default with engines distant from both fuel and main spars, for fire
burns through aluminium like tissue paper 0
�TO
Why didn't you call?
Bob Livingstone
ATC Bankstown Tower
ESPITE the wide variety of accidents and
incidents in General Aviation VFR flying,
there is one cause which stands out in the
statistics year after year - weather-related
accidents; they occur again and again. How
many times have you read at the end of a
report : 'Probable Cause: the pilot, who was not
rated for flight in IMC, continued flight into
non VMC.'?
We in Air Traffic Services CATS) often think
that a contributing factor is the reluctance of
pilots to advise us of their problem by radio in
sufficient time for us to be able to help. The Air
Traffic Controllers and Flight Service Officers
who guard the frequencies are not the police,
watching for infractions of the regulations and
waiting to pounce on an offender. We are there
to provide assistance as an integral part of the
Search and Rescue service provided by the
Authority.
As currently outlined in CARs 98(1) and 110(1),
the functions of Air Traffic Control and Flight
Service are:
D
Air Traffic Control
(a) prevention of collisions between aircraft,
and, on the manoeuvring area, between aircraft and obstructions;
(b) expediting and maintaining an orderly
flow of air traffic;
(c) the provision of such advice and information as may be useful for the safe and
efficient conduct of flights;
( d) the control of the initiation, continuation,
diversion or termination of flight in order to
ensure the safety of aircraft operations; and
(e) notifying appropriate organisations regarding aircraft known to be or believed to be in
need of search and rescue aid, co-ordinating
search and rescue aid and otherwise assisting
those organisations, as required.
Flight Service
(a) the provision of such advice and information as may be required for the safe and
efficient conduct of flight; and
(b) notifying organisations regarding aircraft
known or believed to be in need of search and
rescue aid and assisting those organisations as
required.
If you as pilot do not tell ATS of your problem,
we are unable to help. The later you leave it
TO
AIR
the harder it usually is to provide that help the conditions have deteriorated, fuel expiry is
looming or daylight is running out.
Those of you who have experienced such a
trauma will know that there is nothing worse
than finding yourself in the dark or out of fuel
or on top of cloud uncertain of your position
(or worse, a combination of these predicaments). Many years ago I lost a friend in these
circumstances - he attempted a forced landing
in the dark straight into a clump of trees.
Some of the flying fraternity consider ATS staff
to be WOFTAMs - a Waste of Flaming Time
and Money - and, to a degree, I can see their
point. The only time I really feel that I have
earned my salary is when I have helped someone avoid a collision, helped another out of a
sticky situation or assisted a pilot in handling
an aircraft malfunction.
Many of the ATS officers whom you know only
as voices have years of experience in their jobs,
and lots of us are pilots too; not only private
pilots, but some high time commercial flyers
who continue to hold command. They have seen
it all before, have helped many others before
you and will put your safety ahead of any
other task expected of them.
Many times I have been able to solve the p ilot's
dilemma in just a couple of seconds.
Imagine the relief of knowing that you have
been directed to an area where shortly you will
see the ground and can descend safely for a
landing, instead of blundering on 'in the hope'! I
once had a student pilot, still on runway heading and just two miles from take off in poor
visibility, call that he was lost. Of course he
wasn't, but he realised his limitations and
reacted quickly. With binoculars I sighted him
instantly and directed him to a safe landing in
no time at all.
Did this pilot get into trouble because he called?
Of course not; had he waited even another few
seconds he would have been out of sight and
getting him back to the field would have been a
much involved process. I would, however, question the competence of the instructor who authorised his flight in such conditions and I cannot
guarantee that there would be no further CAA
involvement for the pilot in command in circumstances such as these.
All ATS officers involved in incidents are dutybound to submit an Air Safety Incident Report
(ASIR) on the situation after it is over. The
AIR
ASIR system is designed to highlight trends in
aviation safety so that general remedial action
can be taken to arrest that trend.
In an incident of the type described above, a
Bureau of Air Safety Investigator, should he
think that any further action were required,
might interview the pilot in an attempt to
determine why the situation occurred and to
ensure that it was understood by the pilot so
that it would not happen again. If any lack of
understanding of the necessary elements for
safe flight were found, I am sure a recommendation would be made for the further education
of the pilot. But I repeat - get into trouble?
No! We are speaking of education and understanding, not punishment. It is better to discover one's shortcomings and rectify them than
die denying them.
ATS officers can be your best friends.
Avcharges pay for their salaries - use their
services!
(I feel the writer undersells himself - ATS officers earn their money all right: the daily
smooth handling of all types of traffic bears
witness to that. Sorting out emergencies is
merely an extension of normal services - ed)
What is your situation? Caught on top of cloud
or underneath it with a lowering, base and
increasing rain?
• Am I absolutely certain of my position?
• Just what is the terrain around here like?
• Where's the nearest suitable aerodrome?
• What heading should I fly to find it?
• When is last light?
• Am I going to have enough fuel?
• Is there a hole in the cloud somewhere where
I can descend safely?
A lot of questions! Why, when help is as close
as a radio call, should you on your own be trying to answer all these (and more)? Just flying
the aeroplane, keeping out of trouble and away
from controlled airspace is work enough for one.
If the aircraft you fly is equipped with a transponder, find out how to use it. Within radar
coverage your exact position can probably be
found within seconds and any terrain problems
avoided immediately. ATS has instant communication with associated units, Met. offices, and
other aircraft able to give a rapid picture of the
weather situation. Many times I have been
asked if the conditions in the area I can see
from Bankstown Tower are such that an aircraft caught on top would be able to get down.
Al Yes, provided the RH control column has
been removed and the family members are
qualified, current parachutists.
(CAO 29.1.0.4.2, 4.5, and 4.6)
A2 The answer is maybe, as not enough information has been provided for a definite yes or no.
Firstly, the aerodrome must be at least an ALA
(since it is not listed in ERSA, it cannot be a
licensed aerodrome). AIP AGA-6 and VFG Section 8 detail the physical requirements for an
ALA: if the strip fails to meet these stipulations
you may not legally land there.
Secondly, although the strip be an ALA, its
dimensions must be sufficient for the requirements of the Cl 72. Strip width details for aircraft under 5700 kg are to be found in AGA-6
and the aircraft flight manual sets out the
length needed.
Thirdly, if you just pop in on someone's airstrip
without an invitation you could be in for a big
surprise! Civil Aviation Regulation 93 (Protection of Certain Rights) contains a warning that
needs to be understood. You could be charged
with trespass, and in the event of damage to
your aircraft caused by some deficiency in the
ALA you may have no claim against the owner;
indeed, legal action could be taken against you
for damages to the owner's property.
Finally, a word of warning. Many insurance
companies these days can be quite reluctant to
pay out claims if the pilot is seen to be in
breach of regulations. For example, if the strip
on which you landed had, say, something of a
ditch across the middle (so therefore could not
be an ALA), it is quite possible that any repair
bill may have to be paid out of your pocket.
(note: the CAA video 'Going Bush', plus Steve
Tizzard 's exhaustive article concerning ALAs
in Digest number 135 will refresh your knowledge about this aspect of General Aviation).
A3. (a) commence a climb to circuit altitude
(b) position the aircraft on the active side
and parallel to the nominated runway,
whilst maintaining separation from
other traffic.
(c) follow ATC instructions where issued,
otherwise re-enter the circuit from
upwind
(AIP/ RAC-OPS 1.63 and 1.64)
A4 In the Flight Manual.
A5 No
(AIP/ IAL-2-18 para 4.4.1)
�
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Aviation Safety Digest, number 146 (Spring, 1990)
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146
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1990
-
https://collections.heritageoftheair.org.au/files/original/1b52bb36fe24b11db46617d9e0f2a86a
e183a0f5a2ef53679f8b03400f293bd9
PDF Text
Text
CARBURETTOR ICING
----- 53 ~
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KNOW TBE FACTS
• KNOW THE FUEL SYSTEM.
• KNOW YOUR MET.
• KNOW HOW TO RELATE IN-FLIGHT CONDITIONS
TO ENGINE CHARACTERISTICS.
• KNOW THE PROCEDURES FOR YOUR AIRCRAFT.
• USE HEAT FOR PREVENTION - IT MAY NOT BE
AVAILABLE FOR CURE .. .
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�Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by lhe
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots). registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distnbutees who experience delivery
problems or who wish to notify a change of
address should contact:
Manager, Publications Centre, P.O. Box 1986
Carlton South, 3053, AUSTRALIA
Telephone (03) 342 2000(4 Imes): 008 33 1676
008 33 4191, (03) 347 4407
Aviation Safely Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Contents
4
Be ice conscious
8
Thunderstorms
9
Take-off accident Moorabbin airport
10
Think it through
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone 008 02 6148. Telex M62013
1~ Quiz
Subscriptions may also be lodged at
Commonwealth Government Bookshops rn
the capital cities.
13
Field Office Forum
11.
My BFR
1
Survey of General Aviation
crashworthiness features
1
Nil Defects
11
Airflow
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor :wd are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The articles
are intended to serve as a basis for discussion
and even argument in an effort to identify and
resolve problem areas and potentially
hazardous situations.
Unless otherwise noted, articles rn this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contnbut1ons are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the rratenal without altering
the author's intended meaning.
Reader contributions and correspondence
should be addressed to:
The Editor.
Av1at1on Safety Digest
Civil Av1at1on Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Telephone (06) 268 4583
©Commonwealth of Australia 1988
ISSN 0045-1207
B89 /20570 Cat. No. 89 0558 2
Printed by Ambassador Press Ply Ltd
51 Good Street. Granville, N.S.W. 2142,
AUSTRALIA
2 ' .. Take a
22
deep breath!'
Ground to air
Editorial
Winter is upon us and, although by no means
confined to that season, icing has the ability to
cause problems to anyone flying an aeroplane.
We hope that t he covers and t he article inside
will serve to refresh your awareness of this
ever-present hazard.
Field Office Forum is the first of what I hope to
be a regular series of articles from those who
deal with you on a daily basis. It is a furtherance of an attempt to increase the relevance of
the content of the magazine, and I for one w ill
be interested to find out if in fact there are any
real differences State to State.
The Authority has a new Chairman of t he Board
and those of us who know Dick Smith are prepared for exciting times ahead. Th is magazine
is in full sup port of the initiatives already produced, for there is a difference between a formal Public Service Department and the
Government Busi ness Enterprise that the CAA
is about to become; this is thrown into sharper
focus by the impending deregulation of Australian c ivil aviation. Our legislation , as I mentioned earlier, will reflect advances in thinking,
and concerni ng safety in flight (which is what
ASD is all about), perhaps I might quote the
Chairman direct , from a presentation he made
recently to CAA workers , in which he d iscussed
that axiom of the bus iness world 1 cost-benefit:
.. . I do know that if you go to spend money in
the most effective way you've really got to look
at it in a cost-benefit way. Some of you might
have read the Swedavia-McGregor report fram
New Zealand where they have done that. It
appears they have been doing it in Northern
Europe and in North America for about ten ·
years now. And it does mean valuing a life and
working back from that. People might be horrified, 'Oh, you can't value a life!' Well, that's
what we've a/ways been doing subjectively. You
have to do that of course, because otherwise
you just have to keep spending more and more
money.
As far as most of us are concerned, let me
reiterate what I've said before in comment: the
chances are that we as operators have got the
complicated , expensive th ings nicely covered
off - it 's the simple and obvious that seems to
catc h so many out. Learning may be tedious
and se lf-discipline onerous, but they gain us
many points in the categories 'cost-effect ive '
and 'fli ght safety' . It d oesn 't cost us megabucks
to hold our lives in high esteem .
Covers
Front: 'Induction Icing' by Andrew Rankine
CAA Graphic Design Studio
Back: Gary Clark (Ding Duck's idiosyncratic
approach to flight safety can be seen
in the new edition of 'Clear for
Take-off')
Editor:
Editorial Assistant:
Roger Marchant
Lyn Coutts
Diagrams:
Kathy Foldszin
Soussanith Nokham
Cartoon
Photographs:
P12
PB
pg
P11
P17
P20
Soussanith Nokham
Brenton Hollitt
BAS/ file photo
Kim Wirth
Andrea Hirschon
Roger Marchant
�Aviation Safety Digest
145
Aviation Safety Digest
145
Be ice
conscious!
or
'Give the carby
a fair go ... '
Question: Whal is carburettor icing?
Answer: Carburettor Icing is the accumulation
of ice in the fu el discharge nozzle, the butterfly
valve and the Venturi of the fuel induction system. If this build-up is allowed to continue the
supply of fueljair mixtu re to the engine will
r educe to the point where the engine may stop.
Case history 1.
' ... post-accident examination of the engine
revealed no evidence of any mechanical or system malfunction and later, when the aircraft
was lifted back on to its wheels, the engine
s tarted and ran normally. Although the we ather
at the time was fine and very warm, the
humidity was high and conditions were
es pecially favourable for carburettor icing. The
symptoms accompanying the loss of power were
characteristic of the formation of ice in the carburettor and , in the absence of any mechanical
defect, it was concluded that ice had built up
undetected in the carburettor to the point
where the engine had lost all power .'
Case history 2.
'Shortly before taking off from Moorabbin on a
dual training flight in a Cherokee 140, the
instructor had briefed his student on practice
forced landing techniques, including engine
handling and the use of carburettor heat. Once
airborne, the aircraft was flown to the local
training area where, levelling at 2 500 feet, the
student applied pa:rtial carburettor heat and
closed the throttle to s imulate engine failure.
Leaving the carburettor heat control in this
intermediate position , the student completed his
emergency cockpit drills , selected a field and
established the a ircraft in a forced landing pattern, clearing the engine every 500 feet until
the a ircraft had descended to a height of l OOO
feet. Without cle aring the engine again, the
student continued the descent until, at 300 feet,
the instructor was satisfied with his performance and told him to go around. But when the
student opened the throttle, the engine did not
res pond. The instructor immediately took
control but the aircraft was by now very low
and he had no choice but to continue with the
forced landing into the selected paddock.
Although the ground was wet, the aircraft
touched down normally and rolled t o a stop
undamaged.
The cool and humid conditions existing at the
time were conducive to the formation of carburettor ice and when, a short time later, t he
engine was started and ground run sat isfactorily , it appeared clear that ice had formed in
the carburettor during the descent and the
small amount of heat se lected had been insufficient to prevent it building-up. When no fault
could be found with the engine, t he aircraft
was moved to a dry part of the field and was
flown back to Moorabbin without further
incident.'
of moistu re in the intake air it can cond ense to
form frost or ice. Even a small amount can
r estrict the eff icient flow offuel/air to the engine.
The temperature range of + 15° C to + 30° C
with a relative humidity of 50 % is most dangerous, with outside temperatures around + 15° C
consi dered most significant.
0
Question:
What are the warning signs available to the pilot?
A nswer:
The eff ect of induction icing is a gradual, progressive decline in the power delivered by the
engine. With a f ixed pitch prop eller this may
becom e apparent by r ough running, reduced
RPM and thus reduced airspeed. With a constant speed propeller, there will normally be no
change in RPM but the same decrease in aircraft perf ormance will occur. With a manifold
pressure gauge, a d ecrease in manifold
pressur e may be noted befor e any significant
d ecrease in aircraf t performance. With an
exhaust gas temperature indicator, a decrease
in e.x haust gas temperatiire will occur before
an y n oticeable d ecrease in engine and aircraft
performance. If these indications are not noted
by the pilot an d no corrective action is taken,
the d ecline in engine power will probably progress u n ti l it becomes necessary to relrim lo
maintain altitude and engine roughness will
occur probably f allowed by backfiring. B eyond
this stage, in suffi cient power may be available
lo maintain flight and complete stoppage may
occur, especially should the throttle be moved
abruptly.
Case history 3.
'A student pilot, while on a dual training flight
in a Beech Musketeer from a country aerodrome
in Victoria, was being instructed on in-flight
emergency procedures. The exercise. had commenced with the instructor demonstrating
action to be taken in the event of fire. Starting
at 4 OOO feet, he had shut down the engine by
closing the throttle and turning off the fuel and
ignition switches. At this stage, he selected full
carburettor heat. Once the aircraft was es tablished in the descent and he was satisfied that
t he student was familia r with the procedure , he
decided that, wit h the height still in hand, he
would demons trate re-starting the engine by
diving the aircraft.
After stopping the propeller , t he instructor set
the controls for a res tart, and then pushed the
nose down until, at 125 knots , the prope ller
began to windmill. But when he levelled out
and opened the throttle, there was no response
from the engine. Double checking the various
engine controls, he pers is ted with his starting
attempts until, at 2 300 feet, he re alised t ha t
the engine was not going to fire. Committed
now to a forced landing, the instructor established the aircraft in an approach to a field
only a short distance from the aerodrome and
put the aircraft down without damage. Shortly
afterwards, a licensed engineer examined the
aircraft but could find no defect. The engine
was started without difficulty and afte r it had
been s uccessfully ground run, the aircraft was
flown back to its base by the CFI.
In all three case his tories, the engine failure
was attributed to the s uspected formation of
carburettor icing.
Question:
How does Carburettor ice form and under w hat
atmospheric condi tions is it m ost likely to occur ?
Answer:
Carburettor ice resu lts fr om the cooling eff ects
of fuel vaporisation and air pressure drop
across the Venturi. The air can be cooled by as
much as 40° C an d depending upon the amou nt
I
Every year the accident and incident r ecords
conta in a number of occurrences in which carburettor (induction) icing was conside red to be
t he probable cause of a n engin e power loss .
BASI records indicate 97 cases of induction
icing between 1980 and 1989, fourteen of which
were followed by for ced or heavy landings
r esulting in substantial d amage to the ai rcraft.
Remember, these ar e only the reported cases; it
is not unreasonable to suppose that plen ty more
pilots were frightened by th rottle stiffness and
d w indling power attributable to t he presence of
ice in t he fuel induction a rea. Carburettor
(induction) icing has exposed the occupants of
light aircraft to u nnecessary danger and has
cost oper ators many thousands of dollars during t he past few years . Despite the increased
emphasis placed on this problem by t he flying
t ra ining organisat ions, we find ma ny light aircraft pilots are still being caught out. Simply,
t hey spring the t rap because they eit her fail to
appreciate the wide range of conditions under
which car burettor icing can occur, or do not
recognise the symptoms in t ime to take corrective action. Although t his p henomenon is by no
means res tricted to the appr oaching colder
months of the year (over t he last ten years 38%
w int er, 26% s pring, 23 % autumn and 13% in
s umme r have been t he propor tions), it is an
opportune t ime to again r evise our actions as
p ilots should we suspect carburettor icing.
The following paragraphs offer you food for
t hought as to what h appens, why it happens
and when it is most likely to happen. A few
minutes of your t ime thinki ng along these lines
and refamiliarising yourself w ith the procedures laid down for each a ircr a ft t ype you
fly may some day save your life, or a t least
your hip pocket.
�Aviation Safety Digest
145
Aviation Safety Digest
145
Vital to the successful management of an aircraft engine is a knowledge of its method of
operation and a DETAILED knowledge of the
manufacturer's instructions plus the relevant
information contained within the flight manual,
pilots notes, owners handbook, and company
operations manual (where applicable).
It is impossible to over-emphasize the need to
comply with these instructions. The engine
manufacturer has expended a lot of effort, time
and expense to design and install a hot air
supply to combat ice formation in the carburettor; he knows his product like no-one else: he
has, in line with Government regulations,
ensured that all test points have been satisfied
in the operation of the engine. This necessarily
includes the pilot actions necessary to avoid or
mitigate induction icing.
A quote from the aeronautical engine design
standards applicable to Australia sets out
manufacturer responsibilities:
'Fuel and induction system
(a) the fuel system of the engine must be
designed and constructed to supply an appropriate mixture of fuel to the cylinders throughout the complete operating range of the engine
under all flight and atmospheric conditions.
(b) The intake passages of the engine through
which the air or fuel in combination with air
passes for combustion purposes must be
designed and constructed to minimise the
danger of ice accretion in those passages. The
engine must be designed and constructed to
permit the use of a means for ice prevention. '
(FAR 33.35)
It is up to you, the pilot, to recognise the conditions under which t hese means sh ould be
used. If you follow the book, you are doing t h e
best in your ability t o operate the aircraft
safely and efficiently . As with everything else
in aviation, ignorance, carelessness or plain negligence can exact a terrible toll.
The most important single factor is to be aware
of the atmospheric conditions favourable to
icing, and thus be on th e alert for the operational symptoms in their earl'y st ages. The
cooling effect of fuel evaporation w ithin t he
carburettor will reduce t he air temperature by
as much as 15° C. In clear air conditions where
t he humidity exceeds 70%, or in rain, cloud, fog
a nd some forms of haze, the moist ure present
can be sufficient to produce a dangerous
accumulation of ice. Under these conditions carburettor heat may be required at some stages of
the flight, and it may be necessary to clear the
induction system prior to take-off. The operational application of hot air w ill vary w ith
indiv idual aircraft and engines, and a pilot
should follow implicitly the instructions contained in the manufacturer's or operations
manual. In addition , it is well to remember that
under most conditions the formation of carburettor ice is a relatively slow process and it is
possible for a pilot not to recognise the early
symptoms of icing unless he is conscious of the
significance of the meteorological conditions.
Basically, a carburettor functions a gr eat deal
like the expansion valve in a mechanical
refrigerator, w ith t he result that a temperature
difference as great as 15° C can exist between
the free outside air temperatur e and the
carburettor-mixture temperature. A carburettor
can literally manufacture its own ice - at any
season of the year.
Three t ypes of carburettor ice can be encountered. They are Impact Ice, Throttle Ice, and
Fuel Evaporation Ice.
Impact ice is formed by snow, sleet or
supercooled water droplets impinging on surfaces where there are changes of direction in
airflow. It includes the ice formed when water
strikes s urfaces, such as carburettor air
intakes, which are below 0° C. Impact ice may
seriously affect engine operation where ambient
temperatures are below o· c, particularly if
snow, sleet or sub-cooled liquid exists in the
atmosphere.
.
Throttle ice is formed at or near the throttle,
particularly when it is in a part closed position ,
and is due to the drop in temperature which
accompanies the reduction in pressure created
by the Venturi effect. It is formed from moisture particles which freeze outside the airflow
boundary laye r and are t hen carried to metal
surfaces su ch as the t hrottle butterfly by t heir
initial momentum. Comprehens ive tests show
that throttle ice may form in air temperatures
up to about 3° C. Wh ere the air t emperature is
above 3° C the cooling effect of the increased
velocity alone is insufficient to result in icing.
Fuel evaporation icing is caused by the vaporisation of the fuel after it is introduced into the
intake a irstream. The heat required to ch ange
the fuel from a liquid to a v apour is supplied
mainly by the airstr eam, with the result that
even t hough the outside air temperature may be
well above freezing point, th e temperatur e of
the a ir passing through the s ystem aft of the
fuel spray nozzle, an d of the surrou nding structure, can be reduced to below 0° C. This type of
carburettor icin g is the most common and it
may cau se rough running by upsetting the fuelair ratio, or the mixture distribution through
the manifold, as well as engine failure by
obstructing the passage of air t hrou gh the
carburettor.
Carburetor Icing
Fuel
0
It is possible t hat all three types of icing will be
encountered at the same time, but that arising
from fuel evaporation is t he most likely except
in extremely cold condit ions.
Recognition of the symptoms is easier if it is
appreciated that ice in the induction system
acts in the same way a s closing the t hrot tle. As
ice builds up it obstructs t he a ir now, caus ing a
reduction of power and, w ith a fixed p itch p ropeller, a reduction in RPM. With a constant
speed propeller this reduct ion of power will not
in the early stages affect RPM; however, boost,
and airspeed, w ill decrease. Should t he condition be allowed t o progress to a point where
the power developed is not sufficient t o ca use
the propeller to remain above the fine pit ch
stops t h ere w ill be a reduction in RPM even
w ith a con stant speed propeller. Irrespective of
the propeller installation, a suspected format ion
of ice can often be detected by increasing the
throttle opening. If the throttle movement is
sticky or abnormal, or it fails to increase the
power, there is a st rong possibility that ice has
formed and the application of hot air has
already been delayed longer t h an is healthy BUT it is still n ot too late!
Frequently pilots fail to recognise icing in its
early stages and so attempts to increase the
throttle opening by slight increments to compensate for falling off of RPM or boost . These
are precisely the conditions that lead to maximum ice formation. Remov al of ice already
formed is best accomplis hed by use of full carburettor heat. If t he pre-heat ca pacity of t h e
system is sufficient and t he remedial act ion has
not been delayed, it is only a ma tter of seconds
before the ice is remov ed . The pre-heat capacity
can be incr eased by applying more power an d,
where possible , closing cow l flaps .
If ice formation is allowed to progress to a critical extent the loss of power may make it
impossible to generate s ufficient heat t o clear
t he engine. It is for t his reason t hat we have
emphasised t he need to recognise meteorological
conditions favoura ble to ca rbur ettor icing and
take early preventive action.
Use heat for prevention - it may not be
available for cure!
To prevent accide nts resulting from intake icing,
the pilot should be alert at all t imes fo r indications
of icing in the induction system. The fo llowing
represents the sort of advice/ instructions given
by engine manufacturer s :
• Periodically check the carburettor heat systems
a n d controls fo r pro p e r cond it i o n a nd
operation.
• Start the engine with the carburettor heat
control in the COLD posit ion to a void possible
damage to the system and a fire h azard because
of a backfire while starting.
• As a p re-take-off vital action , check the carburettor hea t effectiveness by noting the rev drop
when heat is applied on run-up. If ambient condit ions dict ate , also check for the presence of
car by icing (see next p a ragraph).
• When t he relative humidity is above 50% and the
temperat ure is below 20° C, apply carburettor
heat briefly imme diately before t ake-off to
remove any ice accumulat ed du ring taxi and
run-up. Generally, t he use of carburett or heat
for t a xiing is not recommended because of possible ingestion of foreign matter with the
unfiltered a ir a dmitted with the control in the
HOT or ALTERNATE AIR position.
• Conduct take-of f wit hout carburettor heat,
unless extr eme intake icing conditions are
present.
• Remain alert for indications of induction system
icing during t a ke-off and climb-out , especially
w hen t he relative humidity is above 50 per cent,
or when visible moisture is present in th e
a t mosphere.
• If you have carburettor or mixture temper ature
gauges, use p ar tial heat to keep the intake temperatu re in the safe r ange. Without such instrum e n t a t ion, f u ll h e at sho uld be used
intermittently as consider ed necessary.
• If induction system ice is suspected of causing a
power loss, apply full heat or alternate air. Do
not disturb the t hrot tle until improvement is
n oted . Expect a further power loss momentarily
and then a r ise in power as the ice melts.
• If the ice persists after a period with fu ll heat,
gradually a dvance t he throt tle to full power and
climb at the maximum rate available to p roduce
as much heat as possible. Leanin g with the mixture cont rol w ill generally increase the heat but
should be used w it h caution as it may stop the
engine under circumstan ces in which a re-start is
impossible.
• Apply heat fo r a short time to warm the induct ion syst em before beginning a prolonged
desce nt with the engine th rot tled back. Leave
heat on during the descent and then be ready to
turn t he it off after power is reapplied.
• Remembe r that intake icing is possible with temperatures as high as 40° C and t he humidity as
low as 50%. It is most likely, h owever, where
temperatures a re below 20° Celsius a nd the relat ive humidity is above 80%. The likelihood of
icing increases as t he temperat ure decreases
(down to zero• C) a nd as the relative humidity
increases.
Note: lhe effects and recommendations described
in this article are general in nature and while
they may apply to most piston-engined aircraft,
the final authority must always be the engine/
aircraft manufacturer's recommendations and
the (company) operations manual.
Finally, refer t o all a vailable ope rating instructions and p la cards pe rtaining t o t he a ircra f t t o
determine w hether any s pecia l cons idera tions
or procedures apply to its ope rat ion 0
�Aviation Safety Digest
Aviation Safety Digest
145
145
Don't
Thunderstorms
Bureau of Meteorology
HUNDERSTORMS are the most violent and
potentially destructive smaller-scale
meteorological phenomenon encountered in
Australia.
Storms vary in characteristics, particularly
between the tropics and higher latitudes. However, a fundamental rule of all flying is: STAY
WELL CLEAR OF THUNDERSTORMS.
Associated hazards include turbulence, hail,
icing, low ceiling and visibility, lightning,
downdrafts, wind shear, tornadoes, squall lines,
high intensity rainfall and flash-floods. Thun;
derstorms are usually classified as 'severe' if
surface wind gusts exceed 92 Km/ hr (50 kt) or
hail stones have a diameter in excess of 2.5 cm
(approx 1 in).
Severe storms are continuously well organised
internally with the updraft and downdraft
being separated. This is usually because a
strong windshear (direction and speed) exists
between the lower and middle levels of the
thunderstorm environment.
T
Dome
~ Storm
moUon
. , _ Lowlevel
. , _ environmental
wind
Heevyraln
and hall
Gust front
The following are some SUGGESTED do's and
dont's of thunderstorm avoidance.
Do
Plan to avoid storms . In the first instance if flying into unfamiliar territory gain some appreciation of storm likelihood. Climatological
information is available on thunderstorm incidence for preliminary planning.
Before becoming airborne check the forecast
and plan an alte rnative route if thunderstorms
are predicted. Planning will be far more
rational in the calm of the briefing office than
in flight when confronted with the problem. Be
prepared to divert before thunders torms
become unavoidable.
A void by at least 30 km any thunderstorm
identified as severe or giving an intense radar
echo.
Reduce air speed immediately to the
manufacturer 's recommended airspeed for turbulent air penetration at the first sign of
turbulence.
Don't land or take off in the face of an
approaching storm. A sudden gust front could
cause loss of control and downdrafts can produce a fatal altitude loss.
Don't attempt to fly under a thunderstorm even
if you can see through to the other side. The
vertical currents and turbulence and wind shear
can lead to loss of control or damage to the aircraft. Large hail can suddenly occur in areas
with good visibility.
Don't trust the visual appearance a s a reliable
indicator of turbulence inside a thunderstorm.
Don't assume the air above a storm is necessarily turbulence-free.
Take-off
accident
Moorabbin
airport
0
If you cannot avoid penetrating a thunderstorm, following are some do's before
entering the storm
Tighten your seat belt, put on your shoulder
harness if you have one, and secure all loose
objects.
Plan and hold your heading to take you through
the storm in a minimum time.
To avoid the most critical icing, establish a penetration altitude below the freezing level or
above the level of minus 15 degrees Celsius.
Verify that pitot heat is on and select carburettor heat or turbine-engine anti-ice. Icing can be
rapid at any altitude and cause almost instantaneous power failure and/or loss of airspeed
indication.
Configure y our aircraft for turbulence penetration using power settings and airspeed recommended in your aircraft manual.
Turn up cockpit lights to highest intens ity to
lessen temporary blindness from lightning.
Following are some do's and don'ts during thunderstorm penetration.
Keep your eyes on your instruments. Looking
outside the cockpit can incre ase dan ger of temporary blindness from lightning.
Let the aircraft 'ride the waves'. Manoeuvr es in
trying to maint ain constant altitude increase
stress on the aircraft.
Don 't change p ower set tings ; maint ain settings
for recommended turbulence penetration
airspeed.
Don 't turn back on ce yo u are in a t hunders torm. A straight course through the storm
most likely will get you out of the hazards in
the shortest time. In a ddition , turning
manoeuvres increase stress on t he aircr aft D
the aircraft to r est within t he aerodrome
bound ary. The aircraft gradually lost height
and t he main wheels str uck a mound of ear th
near t he aerodrome boundary . It t hen bounced
acr oss the r oad a nd s truck a telephon~ post,
sev ering some 14 feet of t he p ort w ing, and
finally struck t he ground on the other s ide of
t he road , coming t o rest in a cultiv ated field .
Reprinted from ASD 1
MMEDIATELY aft er becoming airborne from
Moorabbin Airport, Victoria , on 17 January
1953 t he port engine of an Av ro Anson failed.
The aircraft continued across the aer odrome a
few feet above the ground until it struck a
telephone post on the road at the n orthern
boundary of the aerodrome and crashed into a
field on the opposite side of the r oad . The cr ew
of three were uninjured. The aircraft was
extens ively damaged by collision an d imp act.
I
)
History of the flight
On the evening of the day prior to t h is flight
the aircraft was insp ected by a licensed aircr aft
maintenance engineer and found t o be
airworthy. After t he aircraft was loaded and
immediately prior to flight the pilot carried out
a pre-flight ins pection and j ust befo ' leav ing
the tarmac the engines wer e given a f ull r un-up .
An engine revolution drop of approximately
150 revolutions on t he starboard magneto of
the starboard engine revealed during this
run-up w as cleared after t he engin e had been
operated for some 15 to 20 minutes.
The a ircr a ft wa s then taxied to t he take-off
point where the p ilot carried out a pre-take-off
cockpit check. The commencement of the takeoff was quite normal and aft er t r avelling
approximately 1 800 to 2 OOO feet t he air craft
became airborne . At this s tage, t he pilot felt a
loss of power w hich h e at first thought was in
the starboard engine because of t he p revious
rpm drop. However , he immediately r ealised ,
from the tendency of the aircraft to swing to
the left, that the power loss was on the port
side and was moving to pull the port throttle
off when the engine momentarily picked up
again. The pilot thought that it wa s only a
temporary loss of power and decided to
continue to take-off, but almos t immediately the
port engine failed completely. Realising that he
.would not be able t o climb away, the pilot
elected t o fly unde r some telephone w ires on
the northern boundar y a nd land in a paddock
across the road r ather than attempt to br ing
Analysis
An examination of t h e engines failed to r eveal
any defect, abnormality or evidence of
ma lfunct ioning t hat may h ave cont ributed to or
caused t he engine failure .
The testimony of t he p ilot and cr ew r evealed
t hat t here had been an unnecessary,
unorthodox and complicated manipulation of
t he fuel cocks prior to ta ke-off which suggested
t hat t he engine failure could hav e been due to
mis management of the fu el system.
The nature of t he engine failure was consistent
w it h fuel starvation . Furthermor e , the stage at
which the engine failed corr esponds w ith the
p oint an engine would fail if the fu el ha d been
t urned off at t he pre-take-off posit ion.
Interrogation of t h e pilot r evea led that t his was
only his second flight as a pilot of a n Anson
aircraft for some nine years and that he was
not entirely familiar w ith the fuel system.
Ther e is no possibility that the take-off could
h ave been cont inued after t he loss of on e engine
as tests show that an A vr o Anson , wit h t h e
undercarriage down , w ill on ly just maintain
height on one engine, at an all-up weight of
7 400 lb, w hen operated under standard
atmospheric conditions at sea level. The air craft
in th is case was loaded to approximately 8 200 lb.
Cause
The cause of the accident wa s the failure of the
por t engine, just after the aircraft became
airborne, w hich resulted in the a ircraft being
unable to climb away. The en gine failur e was
caused by fuel star vation p robably due to
mismanagement of the fuel system by the p ilot D
�Aviation Safety Digest
Aviation Safety Digest
145
Think it through!
pilot contribution
'M WRITING to relate an experience I had one
spring. To set the scene, I had been operating
an Aztec in N.Qld for several weeks, when I
had to ferry it back down to Melbourne.
I had already ferried the aircraft to Sydney, the
only major unserviceability being an alternator;
this didn't affect me in any way as at this stage
I was operating in the Private category and
therefore was quite legal. The DME, too, was
u/ s - due to the exorbitant price quoted to
replace a valve whilst away. I didn't consider
these to be major problems, as it was a straightforward flight that was planned.
The day after I had arrived in Sydney I
departed for Melbourne, the planned route
being SY-SLS-CB-CRG-ELW-PLE-EN. I obtained
a forecast that indicated there was no cloud
forecast between SY and CB, but from CB
onwards tops were forecast up to 8 OOOft.
Based on this, I saw no problem in flying to CB
at 8 OOO, then climbing to 10 OOO to remain
clear of cloud.
In Sydney that day the weather was fine and
beaut, so I dressed in shorts and a tee-shirt. I
got airborne and all was going well. As I passed
Shellys I started to feel a little cold, so I selected the cabin heater. Unfortunate ly , that particular day it decided not to work (it had been
OK the day before). However, I decided I could
handle the temperature; I was only a little
uncomfortable and anyway I had a sweatshirt I
could put on.
I then commenced a climb to 10 OOO and much
to my surprise I found myself in cloud
approaching Canberra. By the time I reached
cruising altitude I was still in cloud and there
was a little bit of rime ice forming on the
wings . 'What's a bit of ice?' I thought to myself.
I had encountered that plenty of times before.
However, and much to my surprise, near
Corryong the ice quickly thickened. The OAT
probe froze over at -4 degrees Celcius, and I
was starting to feel the cold: in fact I was
finding it difficult to write or operate the pushto-talk switch.
I
145
The ice build-up continued and I dropped to my
Lowest Safe Altitude of 7 600, which itself was
difficult to maintain. I was starting to get a bit
concerned, due to a number of factors. Firstly,
the oil temps were red-lining. I didn't like the
look of this; obviously the coolers had iced
over. Then there was the fact that I had only
one alternator - should it fail, I would be left
in a real predicament. Another worrying factor
was that the airspeed had dropped from 140kt
in the cruise to a meagre lOOkt, yet my next
LSA was 8 400. I could see the reason for the
drop in airspeed: the HF antenna had grown ice
about an inch thick before it snapped off. Need
I say what the wings looked like!
I informed Cooma FS of the problems and they
suggested that I should head there, as it was
CAVOK. Unfortunately for me, the LSA for
such a diversion was again 8 400, so I had to
rule it out.
As the aircraft was becoming almost impossible
to handle, I decided it was time for an actual
diversion. I had not declared an emQrgency
(what was the use - who could help me anyway?) but I was prepared to if my airspeed
dropped any further.
Albury was the nearest suitable aerodrome, so I
commenced a descent and headed there. Having
passed 6 OOO, the aircraft started to shed ice, so
I figured I was home and hosed. I'd land at
Albury, remove the HF antenna, put on a warm
set of clothes and reset the circuit breaker to
the heating unit.
All these plans were dashed when I was
informed t hat t he only way to get to visual was
via a VOR/ DME approach. But of course the
DME was u/s so all I could do was continue on
to Essendon, as the weather was fairly crook
north of the divide. The only other available
place was Mangalore, but the weather was
down on the deck there , too.
I eventually landed at Essendon without further
incident. The HF antenna was still hanging on
and the VOR antenna, which had been forwardfacing, was bent back by the airflow over the
accumulated ice so that it was perpendicular to
the tail.
I feel that I was extremely lucky not to have
become another statistic. If I had not have been
alone there would almost certainly have been a
disaster, for I think any extra passenger weight
would have put us down.
All this trouble was caused by the desire to get
home quickly. I took the short route without
cons ideration of variable factors such as icing
and cloud heights. Met forecasts are just that
- forecasts. I had no plan of action to get me
out of strife . As soon as I started collecting ice,
I should have diverted to a more suitable route
and, remembering that both oil temps were redlining, we all know what would h ave happened
if I had lost a n engine ...
()
Perhaps I should have declared an emergency, I
don't know, but I was concerned about the consequential grilling that I would possibly receive
from the Department. Maybe there could be
some discussion on this aspect.
I hope that from my experience the readers of
the Digest can learn too.
Ben Schiemer (Examiner of Airmen GA)
thanks the sender for a letter full of good messages, and makes the following observations:
Unserviceabilities
Yes, in my opinion, i t's OK to carry 'legal'
deficiencies (there have been suggestions that if
i t 's fitted it should be working, but that makes
people avoid fitting a lot of good gear). But.. .,
unless you're remaining within the circuit,
don't count on the weather being good as a condition of going unless the patterns are widespread and stable, and if you plan to fly over
tiger country, desert, unfamiliar regions or
through CTAs, make every attempt to have
operational redundancy in critical gear.
Weather
Forecasting seems to be an art with about Prob
05 of being spot on. Because we know this, we
tend to interpret the likelihood of the Met man
being right or wrong in the light of our
preferences at the time. What we must do is
steel ourselves against proceeding on a forecast
that has to be accurate if we are not to be in
trouble. In this particular case, the cloud tops
were forecast 8 OOO and safety depended upon
that being right! It wasn't. Like summer,
autumn and winter, spring weather is fickle,
only more so.
Clothing
I've seen a lot of pilots flying in light clothing
- even wearing thongs. But look at what the
kerosene cowboys wear: boots, gloves, fireresistant suits and helmets - and for the most
part their job is no more haz ardous than flying
a GA aircraft. In an accident, the poorly
clothed pilot will have much less chance of
saving self, family or friends, and as the article
shows, even a minor snag (heater failure) can
become a major problem in adverse
circumstances.
Icing
It is dangerous to venture into icing conditions
if your aircrajt is not suitably equipped. If it
isn't filled with wing boots (that work), propeller heater and so forth, it wasn't meant to be
flown into visible moisture above the freezing
level. Here, our correspondent met only light
ice: in heavy icing conditions an aircraft can
be in dire straits in seconds, and out of control
before it can be turned about. Wings lose their
contour and drag increases; controls lock up
and intakes block over. Perhaps worst of all,
unheated props gather ice and become unbalanced: a potentially lethal sequence unless the
engine is shut down, and then where is there to
go? And at GA airspeeds, once there is an
accretion of ice it is necessary to descend well
below the freezing level before it will melt away.
Emergency
If you have an emergency, a potential emergency or even an incipient problem, tell someone. Forget the OK phrases; tell it like it is and
then either act upon any advice received or do
what you as captain think is best. The ATC/ FS
staff will be your co-pilot until the danger has
passed. Remember that, much as they do not
need it, a call for help certainly relieves the
tedium of (their) routine - they will want to
help and use their professional expertise to
your benefit. In this case, had the FS officer
known about the icing problem, traffic hazards
would have been assessed, cloud areas could
have been mapped out from airborne reports,
suitable diversions would certainly have been
suggested (it is unrealistic to assume a pilot
knows everything about possible bolt-holes),
and other contingency actions would have been
completed to cope with the emergency.
A grilling
I won't deny it's happened, but that's the
human condition. However, I believe a 'grilling'
is much the exception, and not to be genuinely
feared anyway, simply because the CAA,
despite a bad press, will not support an
unreasonable member of its staff The overwhelming ma}ority of us are keen to educate
rather than berate, because we are well aware
which approach is the more effective in the
prevention of accidents. Obviously, if someone
starts to abuse us we react like anyone else, but
really, a 'grilling' is more the stuff of stories
than of fact. To see us as ogres is to deny us
one of our most pertinent functions - that of
sensible analysis, evaluation of options and
further education of all pilots (including ourselves) who have experienced dangerous situations in the air D
�If you are not el igible for a free issue, or if you would like additional copies of the Digest:-
(Answers on page 21)
Ql. You are captain of a charter flight and
arrive over your destination only to find the
aerodrome temporarily closed. There is 150kg
of usable fuel remaining.
Your pax ask t hat they be taken to t heir second
choice, 160 nm away. Aircr aft details: Cruise
fuel flow 80kg/ hr; TAS 180kt 'Approved' holding consumption 48kg/hr
(a) In nil wind conditions, how far may you
plan to fly from your present position
(overhead the original destination) a nd
still return if t hat aerodrome is declared
'open'?
(b) What is the effect on the distance calculated in (a ) of
(i) tail-wind out increase/ nil/ decrease?
(ii) head-wind out increase/ nil/ decrease?
(JJ Harrison, Examiner of Airmen (Theory)
Q2. ATC direct that you climb/ descend 'at standard rate'. What is required?
(G Evans, ATC Townsville)
Q3 (a) When t he pilot of an aircraft at the
holding point to a runway calls 'Ready ',
what conditions must be met?
(b) Having received line-up clearance from
t he Tower , may a pilot back-track to the
runway threshold?
(GR Finlayson, Senior Tower Controller)
Q4. What is the rated coverage of a VOR
beacon?
(a) 60 nm
(b) 120 nm
(c) depends on t h e station - look it up in
ERSA
(d ) depends on your altitude
(Mike Hennessy, Airways Surveyor)
Q5. You are to conduct a VFR private flight ·
from Roma to Gladstone. You hold neither a
NGT VFR Rating nor an Instrument Rating, so
you must plan to arrive prior to last light
Gladstone.
You have obtained the following TAF for
Gladstone:
TAF GLA 2008 26005KT 9999 2CU030 4AC160
RAPID 2301 18010/ 25KT 5CU030
INTER 0608 2000 17TS 5ST007 2CB035
27 30 28 26 1019 1020 1019 1017'
Your calculated last light for Gladstone is
0754UTC and you have a total time interval of
89 minutes.
What is your latest possible departure time
Roma?
(Alan Betteridge, Flight Service instructor)
Q6. May a private pilot legally replace a broken
radio aerial on an aircraft?
(a) No
(b) Yes, providing he owns t he aircraft
(c) Yes, on VFR a ircraft only
(d) Yes, on private aircraft only
(e) Yes
0
F0 LI r issues $A 14 .00
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AVIATION SAFETY DIGEST reports incidents, recounts
stories, relays technical information, represents the p ilot
and others involved in aviation, and, to the extent that it
falls short of being a legal document, reflects the viewpoint of the CAA.
We have noted previously that regulation alone may well
have been exhausted as a means of reducing accidents.
This is not to say the CAA is on autopilot - there are
moves afoot to make CARs, CAOs and subsid iary legislation more user-friendly (or at least, somewhat simpler).
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(including sur/ace postage)
Although an aviator will always benefit from reading about
another's brush with disaster, we are all fortified in the d iligence of our personal pursuit of safety by the knowledge
that there are a lot of fellow flyers who think twice - nay
three times even - before committing themselves (and
their passengers - never forget the pax) to operations in
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marginal conditions. Self-discipline, mechanical reliability
and the correct application of hard-gained expertise are
but the three leading links in the chain of circumstances
that define a truly successful flight.
The wide range of submissions that cross the editor's
desk are testimony that 'marginal conditions ' cover practically everything. There are a million articles out there in
the real world, and a zillion incidents (99% of which you
wouldn't dream of putting your name to - that's OK,
we 'll respect your desire for anonymity). So why not share
your hard-earned lessons? As I said, your story is unique!
To be part of this accumulated wisdom , those with an
interest in flying, be it as a professional or paid-for-byyourself, will do themselves a favour by reading the Digest
on a regular basis; if you do not obtain a free copy, the
subscription form is, as they say, overleaf.
!------------------- ------------------------ ~--1
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Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
G.P.O. Box 367
CANBERRA A.C.T. 2601
Australia
Aviation Safety Digest 145 / i
�AERONAUTICAL INFORMATION SERVICE AUSTRALIA
NOTICE
CURRENT DOCUMENTATION AND
PLANNED NEXT ISSUE
Document
Current Issue
#
Planned Next Issue
Western Australia
#
N Western Australia the aviati~n . industr~ is
faced with the problem of prov1dmg services
to a small population spre ad across a large
land mass: less than one tent h of the population
of Australian lives in an area approximately
one third of the Aus tralian continent. This
small population means smaller revenue generation with consequential limitations on the size
and numbers of the facilities that can be
provided.
This set of circumstances h as resulted in the
development of perhaps higher than a verage
numbers of Authorised Landing Areas ( ALAs)
to service mainly private and charter operations in West ern Australia. People in the aviation industr y are probably aware that the
concept of establishing landing areas by general
description is a means of enabling more people
to benefit from aviation w it hout incurring the
costs associated with the CAA having to accept
responsibility for the day-to-day standard of
these facilities.
A number of the larger country t owns in WA
provide ALAs which are, to a ll intents a nd p urposes of the µsers, the same as licensed aerodromes. This simila rity in appearance has led
some pilots to overlook or ignore the essential
differences between licensed aerodromes and
ALAs.
An important example is that there is no system of notification to pilots when an ALA is
unsuitable for aircraft operations. To overcome
the dangers a ssociated with attempts to land at
ALAs w hich are eit her temporarily or permanently unserviceable, the CAA introduced a
requirement (see AIP AGA-6-2), that pilots ar e
to ensur e that the runway is suitable for landing or take-off. The Notes at AGA-6-6 go on to
remind p ilots that t hey may require the
approval of the landow ner before using an ALA.
It seems that familiarity breeds complacen cy
and during 1989 w e saw in WA a number of
incident reports submitted after pilots had
landed at unserviceable ALAs, thankfully without major damage or injury. In one incident, a
pilot attempted to land in the middle of run way
works - to t he embarrassment of the p ilot ,
a nger of the council worker s, and confusion of
the ALA owner.
The message must be brought clearly home to
a ll pilots who operate regularly into ALAs th at
I
DAP(E)
28-6-90
23-08-90
DAP(W)
31-5-90
26-7-90
INTERNATIONAL
AGA 0- 1-2
31-5-90
30-5-91
AIP (book)
3-5-90
23-8- 90
VFG (book)
3-5-90
23-8-90
AIP/MAP
14-12-89
23-8-90
VFG/MAP
14-12- 89
23-8-90
DAH
14-12- 89
23-8-90
ERSA
8-3-90
23-8-90
#Dates quoted are effective dates
NOTE : NOTAM CLASS I AND CLASS II ARE TO BE READ IN
CONJUNCTION WITH THE ABOVE DOCUMENTS
ISSUE: 10
DATE: 08 MAR 1990
viii / Aviation Safety Digest 145
even though the st rip may look like a licensed
aerodrome there is no system established by the
CAA whereby pilots can be , or are, not ified of
runway works in progress, of temporary damage, erection of power lines, or even of the
closing down of maintenance at an ALA. Even
if you fl y to town once or more a week, it is
your responsibility to ensure, each t ime , that
the ALA will be s uitable for your landing.
There is a lso a message in this for the owners
and oper ator s of large ' public' ALAs (in the
main , country councils or shires). Firstly, be
aware that the CAA does not, and cannot, exercise control over the condition of your 'aerodrome' and, most important ly, cannot provide a
system of notification to pilots when you intend
to carr y out r unway works or otherwise change
the u sability of the ALA. When using an ALA, a
pilot is under a common law dut y of care to his
passengers to take reasonable care in all the
circumstances to prevent injury. It is, of course,
also the pilot's responsibility to ensure that the
aircraft is of a type authorised to land and take
off at that ALA, that the aircr aft is engaged in
operations specified in the instrument of authorisation for that place, and that any condit ions
specified in the aut horis ation ar e complied
with.
ALA owners should also consider their s it uation
at common law, under which is owed a duty of
care t o pilot and passengers of aircraft that are
to u se the ALAs. An owner provid ing an
unlicensed aerodrome which is generally
intended to be available fo r public use, but is
temporarily not s uitable for that purpose, may
be held liable if reasonable steps are not taken
to bring this to the attention of pilots who are
likely to use the facility and thereby cause
damage to th eir aircraft and injury to themselves or other persons.
Although it is not possible to use the NOT AM
system of notification in association with ALAs,
consideration can be given to the use of notices
in local newspapers, to posters at the ALA
itself, notices posted at the offices wher e landing fees are collected, and even aviation magazines such as 40P A. Owners a re advised that
there is no r estriction under aviation law on the
collection of fees for use of ALAs; indeed such
revenue might be used to fund an appropriate
notification system.
Finally, ALA owners in need of assistance in
the marking of unserviceable areas etc are
ad vised that t he CAA Field Offices may be able
to act as consultants, on a fee-for -service basis,
for all matters associated with aerodrome standards and aerodr ome operation D
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Aviation Safety Digest
145
My BFR
Pilot submission
N THE PHONE Ron seemed such a reasonable sort of bloke. He reminded me of the
need to do a flight review every two years.
Even offered to drive out, look over my property and let me operate from my own ALA.
Naturally, I agreed to that.
Anyway, Ron turned up last Wednesday.
He said he was a bit surprised to s ee the plane
outside my homestead because the ALA is
about a mile away. I explained that, being
closer, this trip was more convenient. Actually,
there are power lines crossing it at about midway but it's really no problem to land and take
off because at the half-way point you are
always on the ground.
For some reason Ron seemed nervous. So,
although I had done the pre-flight inspection
only four days earlier, I decided to do it again.
Because he was watching me carefully I walked
right around the plane three times instead of
my usual once.
My effort was rewarded because the colour
returned to Ron 's cheeks - in fact, they went
bright red.
In view of Ron's obviously better mood I told
him I was going to combine the flight test with
my requirement to deliver three poddy calves
from the home paddock to the main herd. After
a bit of a chase I caught the calves and toss ed
'em in the back.
We climbed aboard but Ron started nagging
about weight and balance calculations . Of
course, I knew that sort of thing was a w a ste of
time because the stock likes to move about a
bit. However, I did assure Ron that I keep the
trim wheel araldited to neutral s o we would
always remain stable .
Anyway, I started the engine and cleverly minimised the warm-up time by tramping hard on
the brakes and gunning her to 3 500 RPM.
I then discovered that Ron has very acute hearing. Through all that noise he detected a metallic rattle and demanded I account for it.
Actually it was cau sed by a screwdriver that
last month fell down a hole in the floor and
lodged in the fuel selector mechanism. The
selector can' t be moved but because it was on
'All Tanks' I figured it didn't matter. However ,
as Ron w a s obviously a nit picker I bla med the
noise on vibrations from a sta inless steel
thermos I keep in a be aut lit tle poss ie between
the windshield and the magnetic compass.
0
Abou t half way th rough t he descent I looked
back to see t he ca lves gracefully suspended in
mid air. I w as going to comment on this unusual
s ight but Ron had rolled h imself into t he foetal
p osition and was emitting h igh-pitched squeals.
My ex planation seemed t o r elax Ron because he
slumped back in his seat and looked at the cockpit roof.
I released the brakes to taxi out but
unfortunately the plane gave a leap and spun to
the right. 'Oh hell', I thought , 'not the starboard
wheel chock again.'
The bump jolted Ron back to full alertness . He
looked around wildly just in time to see a rock
thrown up by the propwash disappear through
the windshield of his new Commodore.
While Ron was busy ranting about his car I
ignored his requirement that we taxi to the
ALA and took-off under the powerlines . Ron
didn't say a word - at least not until the
engine coughed at lift off, then he screamed,
'Oh God!'
'Now take it easy', I told him firmly , 'that often
happens on take-off and there's a good reas on
for it.'
I explained patiently that I usually run the
plane on standard MOGAS, but one qay I accidentally put in a gallon or so of kerosene. To
compensate for the low octane of the ker o I
siphoned in a few gallons of super MOGAS and
shook the wings up and down to mix it up.
Since then the engine has been coughing a bit,
but in general it works just fine .
At this stage Ron seemed t o los e all interest in
the flight test. He pulled out some ros ary beads,
closed his eyes and became lost in pray er.
I selected some nice music on the HF t o help
him relax.
At about 500 feet I levelled out but fo r some
reason we cont inued sinking. When we reached
50 feet I applied power and that helped quite a lot.
As luck would ha ve it, at t hat height we flew
into t he dust cloud caused by the cattle and
went IFR. I made a ment al note to consider an
instru ment rating a s soon as t he gyros are
repaired. Suddenly Ron's elongated neck a nd
bulging eyes reappeared. His mouth opened
wide, very w ide, but no sound emerged .
'Take it easy', I told h im, 'we'll be out of this in
a minute.'
Sure enough, about a minute later w e emerged;
s t ill straight and level and still at 50 feet.
Admittedly, I w as a bit s urpr ised t o notice w e
were upside down. This minor tribulat ion
forced me to fly across to a nearby valley in
which I did a half roll to get upright again.
By now the main herd had divided into two
groups leav ing a narrow strip between them.
'Ah', I thought, ' t here's an omen. We'll land there.'
Knowing t hat the tyre p roblem demanded a
slow approach I flew a couple of steep t urns
w ith full flap. Soon t he stall warning horn came
on and so I knew we w ere s low enough. I
turned steeply onto a 75 foot final and put her
down . Strangely enough I had always thought
you could only groundloop in a taildr agger.
Halfway throµ gh our t hird loop Ron at last
recovered his sense of humou r. Talk about
laugh ... I've never seen the likes of it: he
couldn't stop!
Meanwhile, I climbed to my normal NOSAR NO
DETAILS cruis ing altitude of 10 500 feet.
On levelling out I noticed some wild camels
heading into my improved pasture. I hate
camels and always carry a loaded .303 carbine
clipped inside the door. We were too high to hit
them, but as a mat ter of principle, I decided to
have a go through t he open w indow.
The effect on Ron was electric. As I fired t he
first shot his n eck lengthened by about s ix
inches and his ey es bulged like a rabbit with myxo.
In fact , Ron's reaction w as so distracting that I
los t concentration and the next sh ot went
through the port tyre.
Ron w as a bit upset about the shooting (' Probably one of those pinko animal lovers', I
thought) so I decided not to tell him about our
little problem.
Shortly after w ards I located t he main h erd and
decided to do my fighter pilot t rick.
Ron had gone back to praying when, in one
smooth sequence, I pulled on full flap , cut the
power and started a sideslip dow n to 500 feet.
Aviation Safety Digest
145
We finally r olled to a h alt and I released the
calv es. I then began p icking clumps of d r y
grass . Between gut-w renching fits of laughter
Ron asked wha t I was doing.
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'CRASHWORTHINESS' - a p a rt of aviat ion
that nobody really wants to know about s uddenly becomes t op priority when you
are in an aircraft t hat might be ju st seconds
from an unpla nned interface with terra firma.
Sometimes items of crashw orthin ess , su ch as
worn seat atta chments, fr ayed seat belts or
faulty inertia reels, are often overlooked during
t he rout ine inspections of the ai rcraft systems.
To gain a n understanding of the var ious aspects
of cr ashworthiness featur es in GA, t he Aviation
Med icine Branch are cond ucting a survey of aircraft in service. Member s of the Branch , in company w ith Airwort hin ess officer s ar e visiting
various centres throughout 1990. Aircraft,
selected at r andom from the var ious types of
GA operation (training, ag. char ter, etc), will be
care fully inspected. Not, though , before obtaining the owner / operator 's consent - this is in
no way s urveillance: it is an exer cise in education for the CAA w ith the object of gaining
information on the broad issues of
crash worth iness.
I explained t hat w e h ad to stuff the port tyre
wit h grass so we could fly home.
It was t hen tha t Ron started running. The last I
s aw of him he w as off into the distance, arms
flailing in t he a ir and still shrieking with laughter. I lat er h eard h e had been confined to a psychiatric inst it ut ion.
0
Anyhow , t hat 's enough about Ron; I j ust got a
let ter from CAA withdrawing, as they put it,
the privilege of h olding a licence to fly . Now I
a dmit I made a mist ake in taxiin g over the
wheel chock but I can 't see what else I did that
was so terrible. Can you? 0
Better knowledge
=
better safety;
the surveys are for the benefit of all and
your co-operation is sincerely appreciated.
�Aviation Safety Digest
145
Aviation Safety Digest
145
NII~ J)l~l~l~C~'l'S
Cranky business
A major contributing factor to failure in piston
engines is the heat treatment process associated
with the weld repairs of crankcases and cylinders, according to an investigation by the CAA.
The investigation, carried out over the last several months, found that a significant number of
repaired crankcases and cylinders had failed in
service.
CAA investigators found that the failures were
caused by the initiation and rapid growth of
fatigue cracks - some of which resulted in t he
complete separation of cylinders, cylinder heads
and, once, a severe in-flight fire.
These fatigue cracks were related to the
adverse effect welding repairs had on the
strength of the heat-treated aluminium alloys
used in the original engine components. Analysis of the investigation results showed that
repair procedures were not ensuring that the
welded alloy component was returned to
specification.
A report on the issue says, 'Any repair process
which involves heating - for example, preand post-heating, stress-relieving or heating to
a llow disassembly and re-assembly of parts of a
component - may effect the mech anical
properties of the component by affecting [the
strength of the material]. '
The report, t itled 'Deficiencies in Crankcase and
Cylinder Repair Procedures - Continental
Lycoming Horizontally Opposed Engines', was
presented at a conference of CAA
Airworthiness officers in Canberra on 20 February 1990.
The conference, involving technical specialists
responsible for engine defect analysis, maintenance related problems and material evaluation,
was told that there was an increasing number
of failure in piston· engines which h ad been
welded. It was also told that the Feder al Aviation Authority in the US had noticed a similar
trend .
The Canberra conference decided t hat the way
around the Australian problem was an education program to spell out to industr y the
proper techniques to be used for the welding of
aluminium alloy engine components. The planning of this e ducation program is now
unde rway and industry will be advised as soon
as the program is finalised.
Aviation Safety Digest will keep you up to date
on these initiatives D
Lycoming 0-360 crankcase
Dear Sir,
Dear Sir,
I have been told t hat aircrew members should
not be blood donors. This came from an
unqualified source. I am aware that I could get
an expert opinion from Aviation Medicine but I
felt a paragraph or small article in the Safety
Digest on this matter would benefit a number of
people. Maybe you could give this some
consideration for a future Safety Digest.
Re ASD 142, AIRFLOW, page 18:
Gar y Cameron
From time to i·i me the question is asked by
flight crew members as to whether or not they
may donate blood. In a healthy individual the
donation of one unit of blood every four to six
months should not cause any problem likely to
interfere with that individual's ability to
operate an aircraft. All blood donation centres
check the donors haemoglobin level prior to
taking blood. If this level is thought to be on the
low side of normal, blood donation is not
proceeded with. The only other significant
eff ect related to blood donation is the loss of
500mls of fluid volume from the central
circulation. This fluid depletion will invariably
be r eplaced over the ensuing 24 hours by
normal drinking. In light of the above,
individuals who donate blood should allow the
elapse of at least 24 hours prior to proceeding
with duties as a flight crew member.
Dr R W Liddell, Director, Aviation Medicine
Nature of failure: Large section or crankcase broken away
Nt1Wre of repair. Exte nsive welding in Lhe lower skirt region, lower cylinder deck region,
no.3 cylinder
Time si11ce repair. 270 hours
Couse of failure: Rapid propagarioa
or fatigue crack, iniliating near a stud. Parent metal
softened in the region of stud thread, hardness 60-85 HVIO, original component hardness
in the range 97-101 HV lO.
Lycoming cylinder GS0-4 80
Nature of failure: Partial separation of cylinder he3d from barrel - severe inlligbt fire with
engine mounts so badly affected tha t the eng.ioc sagged onto the lower cowling.
Nature of repair. Cylinder barrel chromium plated.
()
Time since. repair. 400 hours +
Time j·inct last inspection: 21 hours
Ca11se of failure: Separation of head caused by rapid fatigue crack grow1h from barrel
retention thread. L)'lindcr head material had been softened by
proccssc~
disassemble and reassemble the cylinder during chromium plating, hardness
the range 60·68 H VlO ·original material hardness in the range 88-921 IVI O.
used lo
or t he head in
The reference by R E Baird, and your reply ,
reminds me of the everyday habit of grabbing
hold of the propeller to push or pull an a ircraft
around. The engine may be cold or hot (she's
right, mate!). Is the ignition switched ON or
OFF? - and I wonder if the ignition's earths
a re intact? (Gosh-where are those earth
points?) Offenders often are experienced airmen , and include instructors.
I'd like to see BLAZONED REMINDER SIGNS
around the hanger and in the flight office.
While I'm on the job, thank you for your valuable publication. The QUIZ is a very good idea,
too; helpful and informative, especiaUy to the
many who are no longer with training
organisations.
Old and Not So Bold.
... and thanks to you, too, O&NSB, for your
support. OK, so we don't hear about too many
heads being chopped off as a result of unexpected ignition, but, once again, the chance of such
an accident is a risk that is totally unnecessary
for anyone to take.
�Aviation Safety Digest
145
Aviation Safety Digest
145
E
Dear Sir
The Summer Aviation Safety Digest contained
an article, on the s ubject of mid-air collisions
between gliders, which highlights an anomaly
existing in the operation of aircraft cruis ing a t
or above 5 OOO'. Whilst their powered counterparts are busily maintaining quadrantal cru ising levels, giving accurate position reports, and
evaluating the relative position of other traffic
in their a rea, all in the interest of collision
avoidance, glider pilots do not ma intain a particular level or track, or, as your article implies,
carry VHF COMMS. Whilst gliders cannot, by
necessity, maintain levels or tracks, the carriage and use of VHF COMMS, if they intend
operating above 5 OOO', would reduce the risk
of mid-airs. If a glider pilot copies the position
report of an IFR CHARTER aircraft which indicates his track will cross the 'cloud street' in
which gliders are operating, a simple broadcast
could avert disaster. If a glider inadve rtently
drifts into an AFIZ (a glider pilot I know says
this happens occasionally at places like Du bbo)
it would be appropriate to alert the AFIS.
The disregard for other traffic which results
from the rules under which gliders operate is,
however, overshadowed by w hat I consider a
dumbfounding disregard of the pilot's own
safety. Your article described two, apparently
experienced, pilots who climbed into aircraft
from which they were quite prepared to jump
and in which all landings are forced , yet did not
have the facility to transmit a MAYDAY when
an a pparent risk became reality. One pilot,
injured and bleeding, had to land near the 'pie
cart' in the hope that someone would notice him
and come to his aid.
I believe anyone who can fly an aircraft, powered or otherwise, can be taught how to use a
FISCOM, and should be obliged to carry and use
VHF if he or she intends to operate at or above
5 OOO'. In the meantime, all those powered
pilots who thought they were safe on full
reporting at or above 5 OOO', beware! Gliders
may be there. Many are deaf and dumb, and
many carry a piece of emergency equipment
you don't - a parachute!
Yours faith fully
Clint Mckenzie
Standards Development Division and the Operational Standards and Procedures Branch of
Airways Operations Group offer the following
comments on Mr McKenzie's observations:
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The matter of carriage ancl use of radio by
gliders was considered al length by the
Authority's Standards Development Division
last year, to honour a commitment give11 when
the flight notification require men ls were
reviewed in 1979. In fact many gliders do
carry quite sophisticated VIJF radios and there
are circumstances when their use is required
(e.g. in controlled airspace). In his article
Duncan Ferguson didn't say, but it is quite
likely his radio was rendered useless by the
collision, just as may occur to an aeroplcwe.
The limitation on glider radios is more due to
limited battery capacity than technical sophistication or pilot ability to ·u se them.
Glider pilots, like all VFR traffic or !FR traffic
flying in VMC, must keep a good lookout, ancl
are obliged to maintain separation from powered aircraft by 500 feet/600 metres.
If glider positional information were passed by
VHF radio to aircraft and/or Flight Service, it
would only be of limited v alue. The information
is valid for approximately tivo minutes only;
beyond that time the altitude and position cannot be predicted.
Apart from traffic, another reason for aeroplanes and helicopters to give position reports
is that the CAA has the search and rescue alerting responsibility for them. Gliders have their
own approved organisation - the Gliding Federation - for search and rescue alerting.
The gliding symbol + +, u•ith or without a W
to indicate wire launching, i.s intended to
imply the presence of gliders within a 20 mile
radius. Hi'hen a gliding contest is on and sei
eral gliders are flying the same course, a
NOTAM is issued to advise other pilots of this.
Gl-iders planning to fly beyond 20 miles from
their base are requested to ndvise Flight Service so that other p-ilots mliy be made awarn of
a glider in the area, but bear in mind that the
pilot's intentions may change depending on the
weather encoimtered en rm1 te. Nevertheless, FS,
having received a radio message fmm a glider
that operations are taking place in a particular area 5 OOOft and abo·ve, icill provide general information to /FR, RPT ancl M.LJ, (and,
indeed VFR aircraft 0 11 a 'one-of) basis) eg
'Glidel' operating in . .. area al time . . . ,last
reported level ... '.
In short, the best way to protect yaw· uircl'qft is
to rely on your own (and /1011 r passengers')
eyes instead of somebody else's l'aclio, 1Phich
can al best only indicate /.hat there may be
something to see.
1
I'd like to know people's reaction to such a
licence in Australia, particularly as the night
rating is not now considered an instrument
rating, and opinion appears to be 'Don't go!',
rather than help to get us airborne.
Requests for an en route instrument rating
have surfaced many times over the years. Quite
rightly, in our opinion, the authority of the day
has not developed a rating for the purpose
specifically described by the correspondent,
although he is right in implying that a signal
delight in flying is the ability to climb ov.t
through some cloud, enjoy a smooth ride on
top, then descend through patchy cloud at your
destination without having to do an instrument
approach. No need for a formal and expensive
course here! However, let me give you another
scenario: some years ago I expected such a trip,
from S. Qld to Canberra, for the weather men
had assured me of VMC all the way. No sir! By
the time I reached home I had flown an NDB
approach to just above MDA for a fuel stop at
Dubbo, and then was faced with a 'real' !LS
into Canberra. Total time in cloud five hours
thirty and two instrument approaches when the
forecast had indicated virtually no cloud!
Proponents of an en route instrument rating for
the Australian scene should think again. Forecasts are notoriously inaccurate, due to, I hope,
the relatively few weather stations given the
size of the continent. Frequently there are no
reliable forecasts or actual reports of weather
(ie no met. observer) at the destination. Therefore I believe it would be irresponsible, on the
balance of probabilities, to state that the proposition would hold good as an approved procedure for Australian conditions, either down
to lowest safe or any other selected height. In
my opinion the hardest part of any instrument
approach - and that is what you might be
committed to once you have entered cloud - is
the necessary manoeuvring from arriv al overhead the beacon to the commencement of the
outbound leg. The rest is relatively easy.
For instance, I was in a twin from Kalgoorlie to
Perth. In comma nd was a four-ringer with an
instrument rating. On take-off he immediately
selected autopilot and stayed on it throughout
the journey. About 50 DME Perth , under radar
cont rol and just past last light we were cleared
to descend from our cruise at 10 OOOft. There
was a band of cloud , tops about 7 OOO, base
around 3 OOO; LSALT was 2 500. The first penetration was in patchy cloud with some sky reference, and par t ground reference. As we
reached 4 OOO, it was solid whiteout for about
thirty seconds before we broke clear. My point
is that under VFR I would be illegal to do that,
and would have had to divert . With an IMC
rating, that slight penetration of cloud would
allow me to complete my journey, without the
complication of a full IFR rating.
To summarise: the 'en route ' instrument rating
is currently catered for by the Command
Instrument Rating, the only safe way, I believe,
to even consider flight in IMC. Although commercial pressures exist to train you on all aids
(NDB, ILS/ LLZ, VOR and DME), a rating may
be obtained on only the NDB if yov so wish.
You need to pass the relevant exams, with just
15 hr of simulator time plus 15 hr of additional
flying trainin g IF YOU ARE GOOD ENOUGH. If
you are serious about your flying, that's the
way to go! - Steve Tizzard (E of A, GA)
EA Mills
/and refer Brian Hill 's letter in ASD 144 re
financing this achievement - Ed}
Dear Sir ,
'Sequence of Events' (ASD 142) prompts me to
have my say in the knotty question of Instrument Ratings.
There is only one useful instrument rating in
this country: the first class instrument rating,
the same as a Jumbo pilot has, together with
the renewal and recency requirements. It also
represents the sort of time and expense that I
for one can't afford, let alone keep on the offchance that I might be caught in cloud someday. As a private pilot of thirty years'
experience, now flying a SE four-seater, that
rating is completely out for me.
u
-
J
In Britain, wher e I learned to fly , and where
instrument flying is a part of life (or death if
you don't have the experience) , they brought in
the very successful IMC rating. It was useful
for people like myself, w ho just needed to penetrate cloud in a controlled condition to go, say,
VMC on top, or descend through cloud into VMC
before landing. We were thus able to go, rather
than stay on the ground, or, what was worse ,
go and try to remain below cloud and risk scattering ourselves over the hills.
�Aviation Safety Digest
Aviation Safety Digest
145
145
A further , and most important, point is t hat the
pilot's oxygen mask must have an integral
microphone (CAO 108.26.5). It's not much use
(dangerous, in fact) to t r y to pass your ATS
messages 'off oxygen ' when you're above
10 OOO ft cabin altit ude.
So the new Order can make compliance somewhat cheaper for operators of pressurised aircraft, and oxygen may be seen both as an aid to
more efficient operations and as a further form
of insurance against the possibility of being
forced into a threatening situation in the air.
' ... Take a deep
breath!'
lncident:At first glance the defails of the flight might not have
seemed particularly unusual - just a Cessna 172 on a
private VFR flight from Broken Hill to a country town in
South Australia. But it didn't take Adelaide FS long to
notice one thing that was out of order: the pilot had
reported to Broken Hill that he was cruising at FL 140. A
Cessna 172? . .. At 14 OOO ft? The FSO called the aircraft
and enquired anxiously of the pilot: 'Are you equipped
with oxygen?'. The reply was slow in coming, with the
words slurred and enunciated very slowly ...
'Nuh-eg-a-tive'.
The FSO immediately suggested that the pilot begin a
descent to below 1OOOO ft. This advice was followed,
although communications from the aircraft still reflected a
state of mental confusion and drowsiness on the part of
the pilot. However, once established below 10 OOO ft there
appeared to be no further evidence of incapacity, the
radio transmissions became crisp and competent and the
flight was completed without further incident.
The pilot later explained that he had climbed to FL 140 in
an attempt to avoid the strong headwinds encountered at
his planned level of 6 OOO ft. Altogether, the cabin altitude
had been above 10 OOO ft for around 35 minutes. Throughout this time, of course, the pilot should have been using
oxygen.
On this occasion he was lucky - an alert FSO picked the
apparent anomaly in aircraft type and actual altitude and
made an intelligent assessment of the true situation. As it
was, the flight ended safely, but it is more than possible
that had it continued at FL 140 without the pilot being on
oxygen the progressive effect of hypoxia (oxygen deprivation) would have led to disaster. (from a previous ASD)
lncident:Aircraft type:
Beech Baron
Pilot rating:
Senior Commercial
Category:
Private flight - Corporate/executive
Details:
Pilot failed to make a position report;
INCERFA declared; contact finally made
and aircraft descended to below 10 OOO
ft; flight completed normally.
Pilot ·had fallen 'asleep' for 22 minutes.
Diagnosis:
Reason:
Hypoxia allied to fatigue
*
ACTUAL ALTITUD
(Non - Smokers(
lL
Feet
Sea level
10,000
20,000
~-
*
\tJi ( - . . .
'"\\........_ ~~Lf / -·;-A
\
rif
*
APPARENT ALTITUDE
{Smokers)
Feet
8,000
4,000
22,000
COMPARATIVE ANALYSIS OF HYPOXIA SYMPTOMS VS ALTITUDE
Ambienl Allilude
(Feel)
Time before
Symptoms
Typical Symptoms
none
4000
10000
IVIL AVIATION Order 20.4 has been
reissued, and one positive result is that it
now should be significantly less expensive
to fit an oxygen system for certain types of
operation.
This article only addresses single-pilot aircraft
(there are additional changes in the Order relevant to multi-crews, but they will be actioned
by company check and training organisations).
Essentially, the new Order now allows chemical oxygen systems to be fitted for operations
by pressurised aircraft up to FL 250. The
changes to achieve this are:
(a) the deletion of the previous requirement for
a pre-flight functional check, ie actually
donning a mask and breathing the gas (not
possible with chemical s ystems because , once
initiated, the oxygen-producing reaction is
unstoppable);
(b) for the operating crew, a reduction in the
minimum quantity of supplemental oxygen to
be provided from 45 to 15 minutes ; and
(c) a choice for the aircraft operator to provide
30 minutes of oxygen for 10% of the passengers
or - and this is part of the amendment - 15
minutes for 20% (chemical systems, although
generally able to supply all passengers, only
last about 15 minutes and once oxygen is
initiated it will be necessary to descend to
below 10 OOO ft before the supply runs out).
It is important to remember, though, that there
is still a requirement to confirm the physical
serviceability of the system (mask, hoses etc
pass your visual examination), and that there
must be an approved self-check feature , eg
'press-to-test' light, to assure you that the system h as not previously been fired. This is
necessary because the equipment is likely to be
fitted behind panels, and anyway it may not be
immediately obvious from looking at the oxygen
generator whether or not it has already been used.
C
some loss of Nghl visOn
4Hts.
labgue. slugglshness
15000
2Hrs. {oi 1ess)
fatigue, drowsiness. headache. poor judge.nent
18000
112 Hr. (or less)
lalse sense of wed-being, over-c:onfidence. laulty reasornng,
narrowmg field ol attention, blurring Vision, poor merrory
20000
1/4 Hr. (or lcss)
loss of muscular control, judgement. memory, reawmng, time-sense;
repealed purposeless movemenls; emobonal outbursts
22000
Minutes
26000
4·6Min.
loss ol consciousness
30000
l-2Mn.
Joss ol consciousness
38000
30St'C. (orless)
lossolconsCIOusness
50000
10·12Sec.
Jossofc:onsOousncss
Al(a).
Time to PNR =
convulsions, loss of consciousness
Safe Endurance X G/S Back
G/S Out + G/ S Back
Safe Endurance = Fuel remaining minus
Reserves (ie plan to arrive back with reserves
intact). Therefore 150 minus fixed reserve (45
minutes at approved consumption rate)
36 = 114 kg. This figure represents 11 5% (ie
flight fuel + 15%), so 100% = 99 kg. 99 kg@ 80
kg/ hr = 7 4 min safe endurance
74 x 180
Time t o PNR = 180 + 180 = 37 min
Dist to PNR =
= 111 nm
Time to PNR X G/ S out
60
nm =
37 x 180
60
(b)(i) Take the example of a 40 kt tailwind
from departure:
74 x 140
Time to PNR =
28.8 minutes
360
28.8 x 220
Distance to PNR =
(ii) For a 40 kt headwind:
74
Time to PNR =
x 220
360
45.2
0
Distance to PNR =
=
x 140
60
N OTE: If you are the proud owner of an
unpressurised aircraft which is a ble to fly
above 10 OOO ft, supplemental oX'!}gen could
increase your operational envelope dramatically, if only by allowing you lo climb abo've the
weather or take advantage of fav ourable
tailwinds aloft. H owever, as you are required
to breathe OX'!}gen continuously above 10 OOO ft
cabin altitude, chemical systems will be of limited value because they normally only last for
15-20 minutes. B etter by far, if you wish to consider flight above that altitude, to fit a gaseous
oxygen system 0
t hen a rate of 500 fpm over the 1 OOO feet to
the assigned level
(AIP RAC/ OPS 0-23 10.2.3.3)
A3.(a) If cleared for take-off, a pilot should not
backt rack or stop in a lined-up position ; the aircraft must make a ' roll-on' t a ke-off in one cont inuous movement.
( b ) Yes
(AIP RAC/ OPS-0-52 subject 5)
A4. (d) . For planning purposes, the r ated cover age of a VOR is:
Range (nm)
Aircraft alt itude (feet)
60
Below 5 OOO
90
5 000-10 OOO
120
11 000-1 5 OOO
16 000-20 OOO
150
180
Above 20 OOO
(AIP RAC/ OPS-1-46 8.2.2.4)
A5. Last light as calculated
UTC
minus 10 minute 'buffer'
minus 30 minute Wx holding
106 nm
60
As a general observation, it's important to
realise t hat, although the rules only require
oxygen above 10 OOO ft cabin altitude, mild
hypoxia, t he first s tage of oxygen deficiency ,
manifests itself particularly by night ~bove
4 OOO ft, caus ing a significant loss of v is ual
acu ity ('Aeromedical Training for Flight Personnel', Department of US Army, 1983) . And if
you're one of that fast-disappearing(?) breed,
the pilot who smokes, be aware that even at sea
level t he oxygen efficiency of your body may be
equivalent to that of a non-smoker at 8 OOO ft!
45 .2 minutes
Latest possible arriv al time
nm
In other words , for both tail and headwind the
distance to PNR will DECREASE
(standard n avigation formulae)
A2. A rate of climb/ d escent of at least 500 fpm
until the final I OOO feet of the level change,
- 10
-30
0714
UTC
minus total time interval
= 105
0754
- 89
Latest possible departure time
0545
UTC
(AIP RAC/ OPS-0-12. 3 .2.2 NOTE 2 [but see also
N OTE l ];
VFG 24-1 and 24-2)
A6 . (c)
(ANO 100.5. 1 Appendix II)
�r
TO
CENE: Charlene and Ralph are at the
counter in the Bankstown Briefing Office,
and have submitted a flight plan for a
below 5 OOO ft flight to Hillston in South-West
NSW.
S
FS Briefing Let's have a look ... you've
indicated Katoomba, Cowra and
Officer:
abeam West Wyalong as reportingpoints by putting a plus against
them. You 've also nominated a
SARTIME. If you intend proceeding
B050 on a SARTIME you don't need
to plan reporting points , or to make
position reports. But you are
required to make a broadcas t prior
to transitting the aerodrome at
Cowra, and again at West Wyalong
if you are within 10 miles of the
aerodrome. Plus your inbound call
at Hillston.
Ralph:
What sort of broadcast?
FS B.O:
Well , basically y ou are required to
broadcast at 20 miles from the
aerodrome, or d escending through
5 OOO feet, y our aircraft type, position, actual level, estimate and
intentions. Something like ... 'All
stations Cowra, ZZZ Cessna 172,
two-zero miles north east, two
thousand, Cowr a at four five,
overflying for Hills ton' , will do
fine. Incidentally , you'll be pus hing
it to get VHF contact with Wagga
FS at Hillston. You'll probably have
to cancel SAR by phone, s ince you
don't have HF.
Ch a rle ne :
We 'll phone Wagga FSU w hen we
get into town.
FS B.O:
Fine, but please do not forget! I'll
just amend your plan to indicate
that you'll be cancelling SAR by
phone .
Ralph:
FS B.O:
Does that h a ppen often forgetting to cancel their
SARTI ME?
pilots
More often than it should . My
guess is that pilots t end to get preoccupied once they reach their destination. Who knows - perhaps
they are just so relieved to get
there that cancelling SAR is sometimes overlooked, especially if t hey
are unable to ma ke radio contact
with Flight Service, a nd have to
cancel by phone .
AIR
Charlene:
Checklists would help.
FS B.O:
Sure, but who takes their checklist
with them to the pub , once the aircraft is tied down? By the way,
have you checked the frequency
boundaries on the latest Visual
Enroute Charts? You will be changing area VHF frequency several
times en-route, and you w ill need
to be on the correct VHF frequency
when you make your broadcasts
overflying Cowra and West
Wyalong, and inbound to Hillston.
Ralph:
Will we get frequency change
reminders from Flight Ser vice?
FS B.O:
No, as I mentioned before, aircraft
operating below 5 OOO on a
SARTIME are not required to
report their progress. Flight Ser v ice
would not know where you ar e.
Ralph:
FS B.O:
Ralph:
FS B.O:
Ralph :
FS B.O:
Char lene:
Why's that?
FS B.O:
Mainly, FS workload. In any case,
pilots of VFR aircraft are required
to keep a lookout for other aircraft,
and to listen to the area VHF frequency to ascertain whether there
are any other aircraft in their
vicinity.
Ral p h:
FS B.O:
Charlene:
That's right. Not unless you intend
to climb to 5 OOO feet or above.
What if we do decide to climb
above 5 OOO?
Well, first of all, you have to
report to Flight Ser vice that you
are doing so. You tell them your
callsign, aircraft type, position and
time a t that position, intended a ltitude, next position and estimate,
and destination. You will then get
traffic on any IFR, RPT or military
low je t that you may be coming
into conflict with by climbing to
the level above 5 OOO. If you're
unable to contact Flight Service,
you broadcast the same
information .
Once we're above 5 OOO, will we
continue to get a fu ll traffic information serv ice?
u
Yessir! Let's say that you're finding
it a bit bumpy below 5 OOO and
decide to climb to say, 6 OOO;
you're required to make the report
prior to climbing, and then make
posit ion reports as if you are a
FULLSAR flight . The difference , of
course, is that if you miss a position report, Flight Service wou ldn't
commence SAR alerting until your
SARTIME has expired.
Fair enough . Tomorrow, we'll be
pushing on down to Mildura and
then home to Moorabbin, depending
on whether we finish our business
in Hillston on t ime.
FS B.O:
No problem. Give Wagga FSU a
ring to get your briefing and to
submit your flight plan details.
Have you operated into an AFIZ
recently?
Ch ar lene:
No, not for some time. I was going
to brush up on AFIZ procedures
tomorrow morning.
FS B.0:
like this: 'Mildura, ZZZ, Cessna
172, 30 miles north east, four thousand, circ'uit area at zero five,
inbound; received Bravo'. Mildura
FS will then provide you with
traffic information, if there are any
other conflicting aircraft.
Ralph:
And then comes the circuit area
report, right?
FS B.0:
Right! 'ZZZ, circuit area Mildura,
runway 27'. Then after y ou' ve
landed and are clear of the landing
area, 'ZZZ, landed'.
Charlene :
OK , thanks. What about when
we' re ready to depart again?
FS B.0:
First of all, listen to the ATIS to
find out which runway is preferred, then make your taxiing
report prior to entering any of the
runways 'Mildura, ZZZ, Cessna
If we're above 5 OOO, are we then
required to report our position?
Does that also mean we wouldn 't
get t raffic information?
You'll get t raffic information on
IFR , RPT and MLJ aircraft only
when you advise changing level.
Or, if y ou specifi cally request
traffic, you' ll get information on all
other conflicting air craft, but it
only refe rs to that particular point
in t ime. Flight Service a ren't
obliged to continue to pass traffic
to you.
AIR
TO
The main t hing t o remember about
a n AFIZ is that everyone is
req ui red to make several mandatory reports, so t hat the FSU can
effectively assess you for traffic
purposes.
Ralph:
And those reports a re ... ?
FS B.O:
The first is the report at 15 miles
from the AFIZ boundary, which in
this case would be at 30 DME. By
th is time you should have taken
note of the A TIS on the NDB. If
memory serves me correctly, you 're
reminded of right-hand circuits on
runways 27 and 36 at Mildura. So
your report would be something
172, taxing for Moorabbin,
received Charlie, runway 27'.
Ralph:
What about t raffic information?
FS 13.0:
If there's any conflicting traffic ,
Mildura FS will pass it to you,
otherwise you'll get the advice: 'No
traffic'. Remember, don't e nter the
runway until you have received
traffic information. Once you 're
airborne , report: 'ZZZ airborne'.
Charlene:
Yes, it's a ll coming back to me now.
We report departure: 'ZZZ departed
three zero, tracking one three
three, climbing to five thousand
five hundred', and we get area
QNH from Flight Service.
FS B.0:
That's right . Will you be descending OCT A into Moorabbin?
Charlene:
Yeah; we're getting good at Lane of
Ent ry procedures .
FS B.O:
Well, ever ything looks in order
here; got your weathers and
NOTAMs?
Ralph:
Yep; thanks for you r help .
FS B.O:
No problems, enjoy your flight.
Charlene:
'Bye.
�
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Aviation Safety Digest, number 145 (Winter, 1990)
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145
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1990
-
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PDF Text
Text
National Aeronautical Information Processing System
NAIPS
Available 1992
Telephone Briefing Service
Pilots may obtain a pre·llight briefing (and submit a flight plan)
by letephone from anywhere In lhe counlry, using a 008 number.
Proposed locaUons: BH. CB, CG, CH, MK. MC. MA. PMO,
TW, WG, TL. AK. AV, HB, LT, EN, Ml.AS, BUD . OBY.
KA. KG. KU, GV. CS, PD.
Telephone Switch
Military Briefing Office
·1------000-...
Briefing and Flight Planning
Pilots with a suitable Home P.C.
Telephone Briefing
(k>cal information only)
Centralised Briefing Units (CBUs)
Briefing Officers with terminals conduct briefings by lelephone
Located at Brisbane and Melbourne
a
Existing Pilot Briefing Offices
With Terminals for use by
Pilots and Briefing Officers.
Located at: BN, AF, SY, BK, ~L. MB,
AO, PF, PH, JT and ON
User access lo Melbourne
NAIPS wlll be the same as for
Brisbane NAIPS
Air Traffic Services
Flight Data Pfocesaong CFDPJ
Australian NOTAM
Office (NOF)
Loca1ed 1n Brisbane
NAIPS will:
•
•
•
•
•
•
Provide route-specific pre·fligh t briefi ngs
Prepare flight plan s for pilot acceptance
Validat e and acce pt flight plans for distribution to ATS units
Provide pi lots and companies w ith the means to store regularly used fligh t plans
Receive and store NOTAM and MET data
Contain a database which includes: aircraft performance, AGA data, all air-routes,
standard flight plans, topograph ical data etc.
A contract for the supply of NAIPS was signed o n the 3rd. April, 1989, by CAA and
MacDonald Dettwiler and Associates Ltd. {MDA).
Bureau of
Meteorology
�Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots). registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
Manager, Publications Centre, P.O. Box 1986
Carlton South, 3053, AUSTRALIA
Telephone (03) 342 2000(4 lines); 008 33 1676
008 33 4191; (03) 347 4407
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone 008026148. Telex M62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The articles
are intended to serve as a basis for discussion
and even argument in an effort to identify and
resolve problem areas and potentially
hazardous situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the material without altering
the author's intended meaning.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, AC. T. 2601, AUSTRALIA
Telephone (08) 268 4583
© Commonwealth of Australia 1988
ISSN 0045-1207
B89/20570 Cat. No. 89 0558 2
Printed by Ambassador Press Pty Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
Contents
4
Microbursts
7
Quiz
8
Talk and tank
9
'Prove all things; hold fast
that which is good'
10
Nil defects
16
Quiz answers
17
National Aeronautical
Information Processing
System (NAIPS)
18
Ground to air
19
What fuels these mortals be!
20
A current affair
22
Editorial
Airflow
1
The main article in this edition is concerned with
autopilots, and is competently introduced by a
senior member of our Airworthiness staff. I
make no apology for the fact that it is lifted,
completely, from a sister publication because,
whereas on the most obvious level it·is an
explanation of what can go wrong with your
autopilot and is replete with case histories, what
attracted me was the underlying, and continuous, plea by the author(s) - 'Learn, Know and
CHECK'. This, it seemed, was flight safety discipline in microcosm. The best pilots I know
never, but never, stop learning. They take
advice from wherever it may be available, consider it carefully, then use what they have confirmed to be correct. They are never too hurried
to check and double check, and, knowing that
aviation is an achievement in the face of Nature,
maintain a continued healthy scepticism concerning the safety of any operation. You will
note I said 'best' - alas, BASI statistics indicate that over the last 20 years in Australia 76%
of all aircraft accidents have had assigned to
them at least one human error as a 'major factor'; this gets us nicely back to the article, the
thrust of which is that, no matter what goes
wrong (short of a catastrophic failure), the PIC
of any aircraft should be fully aware of the
reversionary procedures available to at .least
mitigate the problem. Things generally work as
advertised but, as Allan Sherman said in
another context, 'each large appliance
... treats us with defiance'. It's up to us to
show machines who's the boss; to do that we
have to know all their little ways.
I hope the quiz is of interest; given the source
of the questions it certainly should be relevant,
and those who are still to sit theory exams
might do well to consider the content quite
carefully.
Notwithstanding industrial turmoil, aviation in
Australia grows year by year. There were some
800 new aircraft registrations 88-89; all we in
the business have to do is increase our proficiency and enjoy our flying (necessarily in that
order).
Covers
Front: Shows the Flight Station on a
Boeing 737-300
Photograph taken by Bob Finlayson
Back: Facilities available via the National
Aeronautical Processing System
Editor:
Editorial Assistant:
Roger Marchant
Lyn Coutts
Diagrams:
Shirley Wheeler
Cartoons
P16
P21
Gary Clarke
John Inger
Photographs:
P5
PB
B of Met
Gordon Quantock
Lyn Coutts
From Photographic
Competition G. Gunning
P17
P20
�-
...,..
Aviation Safety Digest
J
Microbursts
Aviation Safety Digest
144
Bureau of Meteorology
Over the past 10-15 years there has been a considerable
amount of research on the impact of microbursts on
aircraft operations. This research has been directed
towards a better scientific understanding of microbursts,
the development of detection and warning systems and
enhanced knowledge of aircraft performance within a
microburst. The bulk of this R & D has been conducted in
the USA, where there have been several major accidents
attributed to microbursts.
As recent studies suggest microbursts present a
significant hazard to aircraft operating in Australia, the
following brief summary represents current knowledge on
the phenomena, and is offered as assistance to pilots
generally.
Description
MICROBURST is a strong, concentrated
downburst of cold air from the base of
convective cloud, inducing an outburst of
strong winds near the surface over a limited
horizontal area. The peak wind gusts last only
two to five minutes, but the associated
downdrafts and horizontal wind shear can
present a very serious hazard to aircraft
operations at low altitudes.
Microbursts may be associated with heavy
convective precipitation (the 'wet' microburst),
or there may be little or no rain reaching the
surface (the 'dry' microburst). Typically, the
wet version will emanate from a large
convective cell or a thunderstorm, and
observations from USA suggest approximately
5% of thunderstorms produce microbursts.
On the other hand, in situations where the
cloud base is high and the sub-cloud layer is
unstable and relatively dry, a very light shower
from a thin layer of cloud is sufficient to
generate a microburst. In such circumstances
the precipitation may not even reach the
ground (the 'dry' microburst).
Evaporation and melting of precipitation as it
falls through the sub-cloud air causes cooling of
that air. This cooler, more dense air accelerates
downwards as a downdraft. Downdrafts
associated with microbursts are typically only a
few hundred to 3 OOO feet across. When the
downdraft reaches the ground, it spreads
horizontally and may form one or more
horizontal vortex rings (Figure 1). The outflow
region is typically 6 OOO to 12 OOO feet across,
and the horizontal vortices may extend to over
2 OOO ft AGL.
A
144
When an aircraft flies through a microburst at
low altitudes it will initially encounter an
increasing headwind, followed rapidly by a
strong downdraft and increasing tailwind. This
may result in a rapid and potentially hazardous
decrease in airspeed and angle of attack. In
America, Doppler radar wind measurements
indicate the wind speed change you might
expect when flying through an 'average'
microburst is around 45KT, although
differences of up to lOOKT have been
measured.
Microburst outflows may be asymmetric, and in
these situations there may be no sudden ASI
increase to alert you to the imminent - and
possibly catastrophic - drop in airspeed.
Windspeeds associated with microbursts
typically intensify for about 5 minutes after
initial ground contact, then dissipate in 10-20
minutes' time (Figure 2). Because of its short
life-cycle a reported encounter during the initial
stage of microburst development may not be
considered significant, but an aircraft following
only a few minutes later may get into extremely
hazardous shear.
·
In ill al
Oowndraft
\\\\\
'.:J
Ground
Contact
~ ~
!' '~
I
r..,~,'\\,.",l
Iv
'--1
, __
Maximum
Shear
Intensity
... •
111'
ii\\
I l l\
Il l \
1111
:.:.'i;\.lr..'.: ~!
\ \ j \,_ I
,,;fu)
10
Elap sed Time (min)
Dissipation
Beg ins
·, \
\',1 ·,\1
·'~\\1
Cloud bills~
as high as
15,000 tt
;\~\.....)
~1.?j \\-1\
..._ ,
15
Occasionally, micro bursts in close proximity can
become organised into a 'micro burst line', which
can persist for a long time. Typically, the
microburst line has a lifetime of about an hour,
although individual bursts within the line may
be much less persistent. Microburst lines in the
vicinity of an airport's arrival and/ or departure
lanes obviously pose a most serious hazard to
operations.
• virga. The pilot should be alert to the
possibility of 'dry' microbursts particularly if
the cloudbase is h igh and the sub-cloud lay er
is hot and dry.
Visual recognition of microbursts
This should begin in the flight-planning stage ,
with a close ex amination of current weather
and the forecast for each aerodrome to be used.
Any convection in the atmosphere presents the
potential for microbursts . Remember that if the
conditions are hot and dry and there is a high
cloud base, it takes only small cumuliform
clouds and virga showers (precipitat ion that
doesn't reach the ground) to generate 'dry'
micro bursts.
Some 'clues' to look out for include:
• reports of hazardous wind shear from other
aircraft operating in the area
• unusual fluctuations during take-off or final
stages of landing
• unusual vertical airspeed fluctuations (ie rate
of climb/descent)
• blowing dust, particularly if it appears to
have a circular pattern: for 'dry' microbursts
this may be the only indication of h azardous
wind shear.
• precipitation from convective cloud,
particulary if a curling outflow is evident
near the surface.
Figure 2. Evolution of a microburst. Mlcroburst winds intensify
for about 5 min after ground contact and typically
dissipate 10 to 20 min after ground contact.
Microbursts will often occur in groups, and if a
microburst is encountered or reported, pilots
should be alert to the possibility of further
bursts occurring in the area. If several
microbursts are closely spaced a series of
horizontal vortices can form near the ground;
these can produce very powerful updrafts and
roll forces, in addition to the more familiar
downdraft.
Cloud Base
If wind shear is encountered during take off or
Figure 1. Symmetric microburst. An alrplane transiting the
microburst would experience equal headwinds
and tailwinds.
landing, it is essential that it be reported to
ATS, or details broadcast , even if it is not
considered particularly dangerous. Should t he
shear be associated with a developing
microburst , following aircraft could be placed
in peril.
�Aviation SafetyDigest
Aviation Safety Digest
144
144
Aircraft encounters with microbursts
Microburst encounters have been responsible
for over 600 fatalities and several major
aircraft accidents involving US air carriers over
the last 10-15 years. In Australia, recent studies
suggest a microburst was responsible for the
crash of the Fokker Friendship at Bathurst in
1974.
The best method to avoid an accident
associated with a microburst is to avoid the
encounter in the first place, for some bursts
cannot successfully be negotiated by any known
technique. Nevertheless, meeting a microburst
may be unavoidable, so familiarity with the
conditions surrounding past accidents and
incidents may well be of vital value.
Reported accidents and incidents associated
with microbursts can be divided into three types:
• during take-off on the runway
• after lift-off
• on the approach to land.
Familiarity with these three possibilities will
help the pilot understand what is happening
should he be unfortunate enough to fly into a
microburst. Early recognition of a microburst
encounter will enable him to initiate immediate
and appropriate recovery action. In some cases
as little as 5 seconds may be available for this.
Worst cases could be:
• Encounter after lift-off: The take-off
typically proceeds as normal until a few
seconds after lift-off, when the aircraft
encounters a rapidly-increasing tailwind.
Airspeed is lost, the aircraft descends to crash
some distance beyond the end of the runway
~
Runway
Windshear encounter during takeoff after liftoff. {1) Takeoff
initially appeared normal. (2) Windshear encountered just
after liftoff. (3) Airspeed decrease resulted in pitch attitude
reduction. (4) Aircraft crashed off departure end of runway
20 sec after liftolf.
Because of the short life span of microbursts
and their limited horizontal extent, it is not
really possible at this stage to forecast t heir
occurrence. Systems are being developed in the
USA to identify microbursts and alert ATS and
pilots of their presence. However, the
introduction of such system in Australia may· be
some years away. It is therefore imperative
that pilots be aware of any clues, visual or
otherwise, that may suggest the likelihood of
microbursts upon departure or approach.
Frequency of microbursts in Australia
Recent studies in Darwin with Doppler radar
indicate the frequency of t hunderstorms during
the wet season lead to a h igh possibility of
microbursts. The events observed were .all 'wet'
microbursts, and it is reasonable to extend this
possibility across all tropical areas of the
country whenever convectively unstable
conditions prev ail.
In sout hern and inland areas of Australia the
chance of microbursts also increases with any
increase in convective instability.
In particular, pilots should be alert t o the
possibility of 'dry' microbursts over inland and
southern parts of the country . D
• Encounter on approach to land: In the final
stages of approach the aircraft experiences an
increasing downdraft and tailwind. Airspeed
is lost, flight continues increasingly below the
glidepath, resulting in a crash short of the
threshold.
E decided that the people in daily contact
with the industry were perhaps the best
to pose questions. Therefore, examiners,
airways surveyors, airworthiness engineers, air
traffic controllers and flight service officers
were asked to provide questions that best
represented t he sort of thing that 'bugged' them
as far as the aviation knowledge of their
customers was concerned. A selection, with
(most) authors' names , follows (answers on
page 16):
Ql .Is it legal to test an ELB without notifying
the appropriate authorities?
(Gareth Phillips and Kees van Riel, Flight
Service Officers).
Q2. Who are required to report arrival at noncontrolled aerodromes outside an AFIZ and
what is to be included in such circuit area reports?
(Stuart Hunt, Flight Service, Townsv ille).
Q3. You are operating a passenger-carrying
charter flight by night in a twin-engined
aeroplane not exceeding 5700kg MTOW. Your
destination is Dogsville (DGV). DGV has only
one instrument approach procedure (NDB/
DME), and your aircraft is suitably equipped
with a single ADF and a single DME. The lowest
holding altitude and initial approach altitude
for the IAP is 3 OOO'. DGV has an a erodrome
elevation of 75'. The ARFOR and the TAF
indicate that except for '5CU030', t he weather
forecast for your arrival could be described as
CAVOK. The LSALT for both IFR and NGT VFR
on the final route segment to DGV NDB is 4 300' .
(a) May your flight be planned 'NGT VFR'?
(b) Would you be required t o provide for an
alternate aerodrome?
Enroute, you discover that your aircraft's DME
is faulty ...
(c) Are you required to notify ATS of the DME
problem?
W
Windshear encounter during approach. ( 1) Approach
initially appeared normal. (2) Increasing downdraft
and tailwind encountered at t ransition. (3) A irspeed
decrease combined with reduced visual cues resulted
in pitch attitude reduction. (4) Airplane crashed short
of approach end of runway.
• Encounter during take-off on the runway:
in this case initial indications at brakes-off
may be normal. However, as the aircraft
accelerates the tailwind increases, possibly to
the extent that the end of the runway arrives
before take-off speed is achieved. Even if
initial acceleration seems normal, the
microburst may induce an over-rotation by
the pilot, in an effort to get airborne, even to
the extent of the rear fuselage striking the
ground. After lift-off the tailwind continues to
increase, the aircraft fails to gain altitude and
consequently strikes an object off the
departure end of the runway (ie crashes).
The table further suggests that decreasing the
pitch attitude of an aircraft in order to gain
airspeed will lead to increased loss of lift where
there is increasing tailwind and downdraft.
Changes to wind speed and direction (either
vertically or horizontally) alter both airspeed
and angle of attack, thus altering lift. Whereas
the lift coefficient for an aircraft as a function
of airspeed and angle of attack is of course
dependent upon aircraft ty pe and its flight
settings, the Lift Force Table is representative
of commercial swept-wing aircraft during a
flaps-extended take-off. It shows t he fractional
loss of lift due to a one-knot increase in the
tailwind, or a one-knot increase in any
downflow speed. It can be seen that the loss of
lift due to an increase in tailwind is
independent of the angle of attack, whereas the
loss of lift due to an increase in downdraft
speed increases significantly as the angle of
attack decreases.
LIFT FORCE TABLE
Fractional (%) loss of lift force due to a one knot increase
of the tailwind or one knot increase of the downflow.
For simplification, A = G = 150 kts was assumed.
Windshear encounter during takeoff on runway. (1) Takeoff
initially appeared normal. (2) Airspeed buildup slowed due
to windshear. (3) Airplane reached V R near end of
Angle of attack
runway, lifted off but failed to climb. (4) Airplane contacted
obstacle off departure end of runway.
Loss of lift by tailwind
1.3
Loss of lift by downflow 13.2
1.3
4.5
1.3
2.5
1.3 1.3% per kt.
1.3 0.5% per kt.
(d ) Does the faulty DME affect your plan to use
DGV as a destination? Why?
(e) If your answer to (d) is 'yes', may you
continue to DGV w ith the intention of
landing ther e after makin g a visual
approach?
(f) What requirements must be satisfied before
a visual approach is commenced at night?
(Barry Cowdell, Airways Surveyor).
Q4.Wit hout rushing to your aeroplane , decode
t he colours marked around the ASI.
(Paul Middleton, Assistant General Manager ,
Standards Projects).
Q5.You are planning a flight to Melbourne
(AMML) with an ETA of 0500UTC. At pre-flight
briefing you obtain AD forecast s for AMML
which commence as follows:
'TAF AMD AMML 0324 .... .'
'TTF/ METAR AMML 0230 ... .'
Which statement r egarding the applicability of
t hese forecasts to the planned flight is correct?
(a) Neither forecast s hould be used because
they both expire before 0500 UTC.
(b) The T AF s hould be used because it is valid
until 2400 UTC, whereas the TTF METAR
expires at 0230 UTC.
(c) The TAF should be used because it is valid
until 2400 UTC, w hereas the TTF METAR
only provides a weather trend.
(d ) The TTF METAR should be used because it
is valid until after your ETA, and
supersedes the TAF.
(Paddy Earle , Theory Examiner).
Q6. What is the correct procedure to be
employed in a 'step climb'?
(Rockh ampton ATC). D
�Aviation Safety Digest
Aviation Safety Digest
144
144
Talk and tank
Pilot contribution
AVING held a Private licence for 33 years,
I can be identified as one of those pre-radio
pilots for whom 'clearance' was a green
light from the Tower, and for whom a relayed
phone message usually meant 'Sarwatch
terminated'. Now and again, if lucky, one might
be afforded the privilege of a ride in a new
luxury machine which actually sported that
modern miracle called two-way radio.
Now, thirty years down the track and still
flying, I am amazed and appalled at the radio
procedures used by some GA pilots, even those
with thousands of hours under their belts and
all having known no way of communication
other than radio. I am at a complete loss to
understand why these (certainly not all) pilots
think it as clever, or at the very least
acceptable, to deliver a report which could be
likened more to an underwater kindergarten
party than an integral part of the general flying
safety spectrum. Surely a message that is so
slurred or mis-modulated that it needs to be
repeated two or three times cannot be deemed
to be smart, efficient or time-saving. Yet it is
true that most radio calls are understood by
ATC and FS, because the personnel there are
anticipating THAT call from THAT aircraft and
they know almost word for word what the call
will contain. But other aircraft in the area have
the utmost difficulty in translating these sloppy
calls. This is of course wrong - they should
know what is being said, and indeed have a
right to know. The old rule of 'see and be seen'
is just as important today as it was thirty years
ago, but so is the 'new' rule 'hear and be
heard'. Aircraft separation is the concern of
pilots as well as ATC and FS, and those flyers
who are too lazy to open their mouths and let
others hear who and where they are should not
be afforded the privilege of holding current
licences.
H
•
While FS and ATC are generally above this
criticism, some of the ATIS recordings that
must be endured are also beyond belief. Once
again, if the message can be anticipated and the
pilot is familiar with both the area and the
aerodrome, there will be little trouble
deciphering the message. But this is not always
the case, with the result that pilots are still
making mistakes in busy circuits. Surely a
message that is being repeated over and over
again on a tape is not restricted by time
duration, and therefore should be clearly
enunciated and correctly punctuated. A message
that promotes confusion is worse than no
message at all.
On another matter, there seems to be no
standard fire safety procedures regarding the
fuelling of aircraft from bowser hoses.
Recently, I was involved in heated exchanges
with refuellers at several aerodromes because I
had observed with great concern and
displeasure the refueller removing the cap from
the fuel tank of my aircraft BEFORE connecting
the earth lead from the hose. It seems they
remove the cap, place the fuel hose nozzle in
the tank - and only then connect the earth
strap. Someone please tell me if I am right or
wrong. Surely any static discharge must be
allowed to happen before the tank is opened.
Am I old-fashioned to be paranoid about this
small thing? And if I am right and they are
wrong, why is no one else bothering to tell them
so? I.n other words:
'Earth strap on,
Fuel tank cap off,
Fuel hose nozzle into tank,
Fuel hose nozzle out of tank,
Fuel tank cap on and secure,
Earth strap off.'
We referred these two important aspects of
flight safety to one of our oldest and boldest
examiners. 'Why!', he said, 'Was not everyone
in the aviation game taught 'RSVP'?' Well, we
asked around, and no-one knew what it meant
(perhaps he is too old!). Anyway, the mnemonic
is well-worth committing to memory, for it
reminds us, when transmitting, of'
Rhythm - a steady, even flow of words
Speed - slightly slower than normal
Volume - slight increase
Pitch - slight increase
Incidentally, Air Traff ic Services instructions
(AOI-GEN 12-1-1) limit ATIS transmissions to
30 seconds: 5 for station ident, 25 for
information. The need for clarity is therefore
obvious.
Concerning refuelling procedures, Steve gave
100% to the writer's sequence of events, but
remarked that he wondered how many of us
really knew why this was the only safe way to
treat the operation. We believe every pilot and
every refueller knows full well that the aircraft
has to be earthed from before commencement to
after completion of the fuelling process. There
is no other safe m ethod; certainly sticking a
A VGAS nozzle into an unearthed aircraft that
has perhaps just taxied in from a trip in
thundery weather seems suicidal (and/or
murderous).
There are formal requirements: CAO 20.9 lays
down that the aircraft and all items of
refuelling equipment be connected in such a
way as to ensure that they are of the same
electrical potential. The fuel companies, too,
have strict operating procedures and of course
they include the sequence of action described
by the correspondent.
And yet, and yet... slipshod practices do exist. It
is only to your advantage as the pilot/ owner to
keep a sharp watch on refuelling. If you see
something being done that you think is stupid
- speak up! It's possible that you might be
wrong on occasion, but far better that than
letting a disaster develop due to your timidity. 0
'Prove all things;
hold fast that
which is good'
Seat belts and harnesses are a bit like
instruction books - their v alue becomes
obvious only when all else fails! But:
(1 Thessalonians)
That is why the gear needs to be kept in good
repair. When t here's a catastrophic
deceleration, or application of negat ive ' G', it's
too late to be thinking about that small cut in
the webbing or those torn threads.
There are two answers for damaged or worn
webbing: REPLACE or REP AIR. Strictly
speaking, 'repair' is not the right word, as the
only acceptable fix is to replace it completely
using the existing hardware. Each seat belt
design is approved by strength and functional
tests. Once approved, subsequent belts are
exact 'clones' of the prototype. NO variation
can be legally made without further tests.
Therefore, any re-webbing of a belt must be
carried out by an approved organisation. The
stitch pattern, cotton and webbing must be
exactly similar to the original. However, as this
information is often unavailable, alternatives
must be sought AND APPROVED.
Maintenance organisations, operators and
particularly pilots, whose lives might depend on
it, need to be confident that all seat belts are in
good condition and either original or have been
re-webbed by an approved organisation.
'THAT WHICH IS GOOD' is, of course, you
and your nearest and dearest, and you
certainly don't want to compromise the
safety of any of them. OK, so you make sure
seat belts are done up as part of the pre-take
off checks. But what do we need to know about
the equipment itself?
The pilot of a glider involved in a mid-air
reports thus:
'I ejected the canopy and released the harness,
but could not get out. Looking down I realised
that the harness had not released properly and
I was still held in by the waist straps. I
released these and pushed my f eet out of the
glider, which was now in a vertical dive and
commencing to spin to the right. '
Inspection of the harness buckle revealed wear
marks which indicated that the first element of
the buckle had been protruding too far into the
second element, thereby allowing it to jam.
The buckle could assume this position because
part of the original harness the abdominal pad
had been replaced with a smaller pad which did
not restrict the buckle elements to their correct
positions. The GFA has issued an Airworthiness
Directive.
when a seat belt/ harness is needed, you
definitely want it to work as advertised
REMEMBER - it is dangerous to fit
unapproved seat belts, not because they are
unapproved but because there is no
guarantee that they will work properly 0
�Aviation Safety Digest
144
Aviation Safety Digest
144
NII-'
J)l~l~l~C~'l'S
Traps await
unwary users of
autopilots
The following article is reprinted in toto by permission of
Aviation Safety, 75 Holly Hill Lane, Box 2626, Greenwich,
Connecticut 06836-2626 (all rights reserved).
Frank Grimshaw, Principal Engineer, Avionics,
Airworthiness Branch comments thus:
All pilots should be aware of the potential for
disaster that exists when the untrained, led by
the uncaring, step into the unknown.
Perhaps those last words are a little
provocative, so before reading the article, you
might care to ask of yourself these few
questions:
• do you know how to operate the autopilots in
the aircraft you fly?
• do the aircraft you fly have electric trim
systems?
• have you read the operating instructions?
• is a copy of the operating instructions for the
autopilot and electric trim installation
available in the aircraft you choose to fly?
• have you read the flight manual supplement
that spells out the limitations applying to the
use of the autopilot?
• do you, as a matter of course, perform the
required pre-flight tests of the autopilot
and/or electric trim system?
• do you know the drill for in-flight autopilot
malfunction?
• do you know how to override and disengage
the electric trim system following a runaway?
• what happens if you, as instinct would have
it, overpower the autopilot?
• what did the person who checked you out for
endorsement on the aircraft you fly tell you
about the autopilot and/or electric trim
system fitted? and finally, and possibly of
most importance,
• WHAT DID YOU ASK?
Please read on; the article needs no further
introduction...
0
NE OF THE more complex devices found on
light aircraft is the autopilot. However, as
with any mechanical system, the possibility
of both mechanical failure and operational
error goes up drastically with increasing
complexity. FAA certification regs require that
no single failure of the system will lead to loss
of aircraft control, and the manufacturers go to
great lengths to ensure that the pilot can take
control of the airplane should the autopilot go
bad. However, as the record shows, there are
traps inherent in autopilot systems that can
lure an unwary or inattentive pilot into
difficulty or even disaster.
Insidious failures
Some of the ways in which an autopilot can go
wrong could sneak up on a pilot, and under
some circumstances the failure could go
unnoticed until it was too late.
Aviation Safety's own Mooney 201 displayed
just such a problem at one time. It was first
noticed while flying down the New York VFR
corridor over the Hudson River. The pilot
engaged the autopilot (a Century 41) in
altitude-hold mode. A short t ime later, he
switched on the landing light to increase the
airplane's visibility to oncoming traffic. Almost
immediately, the autopilot began to· slowly
pitch the aircraft down, and some altitude was
lost before the problem was rectified. The
effect was relatively mild and easily controlled
given that the system was shut off almost
immediately. But, it was still an undesirable
and, more importantly, uncommanded change in
trim.
However, the trouble was not in the autopilot
at all. It was the aircraft's alternator, w hich
was not producing sufficient power to run the
landing light, pitot heat and radios as well as
the autopilot. After the alternator was
replaced, the problem never recurred.
Under different circumstances (like on a nightIFR flight , with strong turbulence and a high
stress level in the pilot), the pilot might have
shut off the autopilot, but not noticed the nosedown trim the a utopilot had cranked in until a
dangerous condition had developed.
It should be noted that, t hough the Century 41
has many fail-safe modes that will s hut off the
autopilot a utomatically, this is not one of them.
The only response to low voltage is a flashing
of the autopilot annunciators. The autopilot
remains engaged . A Century representative,
when told of the incident, responded that the
company had not heard of the model 41
producing uncommanded nose-down trim with
low power input (nor have we - it may be an
isolated incident).
Mechanical glitches
When the trouble is in the autopilot, all sorts of
things can happen, some of them alarming.
Aviation Safety obtained printouts of Service
Difficulty Reports dating back to 1973
concerning autopilots and related control
system components. We include here the control
and automatic trim systems, since autopilots
are so intimately tied to them that there is no
real dividing line.
..
Failures that manage to get past the safeguards
built into the system are relatively rare, but
they still happen. Occas ionally, these failures
also produce control difficulties.
For example, one report told of an incident in
which a Piper PA-34-200 Seneca went into a
dive while cruising. A contact had broken off of
the pitch-trim sensor and shorted the unit out,
leading to full nose-down trim. Fortunately, the
pilot was able to recover. A similar failure
affected another Seneca, only in the opposite
manner. The contacts in the pitch-trim sensor
were damaged, preventing nose-down operation
of the electric trim.
There were a few reports of sticking vacuum
actuators in Brittain autopilots. These systems
are unusual in that they are not
electromechanical, but rather vacuum-driven.
The failures may lead to autopilots that w ill not
disengage - and Brittain autopilots have no
alternate method of shutting the system down.
For example, a Brittain B4 autopilot was
involved in an incident in which the pilot of a
Beech S35 Bonanza found he was unable to
move the aileron control to the right shortly
after takeoff due to binding components behind
the instrument panel. He made a successful
landing.
In another report, a Cessna T210M equipped
with an ARC 400B autopilot encountered
runaway trim while in altitude-hold mode. The
autopilot would not disengage, and the pilot
recovered within 200 feet of the ground. The
exact nature of the failure was not reported.
However, one mechanic found four separate
ARC 400B installations (all in Cessna 421Cs) in
which the pitch actuator relay contacts fused
together. As a result, the autopilots could not
be shut off.
Another report told of a Cessn a 421C equipped
with an ARC autopilot. The unit had a defective
computer, reportedly causing violent pitch and
roll oscillations whenever the unit was engaged.
When it comes to Bendix autopilots, clutches
seem to be a trouble point. For example, a
Bendix M4-autopilot, installed in a Beech E90
King Air, had worn teeth on the main servo
clutch, preventing the clutch from disengaging.
Clutch problems plagued other Bendix
autopilots as well. The roll servo clutch in a
Cessna 3 10L failed, locking the ailerons. The
pilot reported the controls to be very restricted.
In another incident, the pilot of a Beech Duke
encountered a frozen elevator in cruise flight.
He suspected ice, and reported that it took a
force of 120 pounds to move t he control. The
actual cause was later traced to a damaged
autopilot clutch.
There were numerous reports of trouble with
bridle cables and their associated capstans on
Eda/Mitchell autopilots. In most cases, failure
of the cables simply disabled the autopilot. In
some instances, though, there were
complications. A Beech El8S had a bridle cable
get tangled in the capstan, locking the aileron
cables. A Piper PA-30 Twin Comanche suffered
a frayed and broken aileron bridle cable, which
led to the cable clamp getting caught on the
aircraft primary structure. This, in t urn, caused
the ailerons to jam in a right-wing down
position.
Many autopilot problems are elusive t o
maintenance personnel. One report told of an
Eda/Mitchell Altimatic 2 installed in a Piper
PA-23-250 Aztec. The Aztec suffered runway
nose-down trim in flight , but the problem could
be reproduced only intermittently on the
ground - a complaint not uncommon with
autopilot systems.
Some reported failures were of the most
mundane nature. A Beech Super King Air 200s
Sperry SPZ200A refused to disengage. The
reason: The engage switch was stuck in.
Poor workmanship by field mechanics was
targeted in several reports. In one report, an
ARC autopilot computer installed in a Cessna
4 l 4A had 15 wire splices in its wiring harness,
one of which had not been insulated properly,
leavin g a bare wire.
In another report, failure to clean up properly
after completing other work caused a King
KFC-200 installed in a Mooney 201 to operate
erratically. Metal chips left from working on
the instrument panels with a drill were found
shorting some of the autopilot's connectors.
The clutch settings on one KFC-200 installation
in a Piper Navajo had been done in reverse the pitch servo clutch had been adjusted to the
roll servo setting, and vice versa.
Three seconds
Just how long does a pilot have to deal with a
problem if the autopilot malfunctions? Should a
major failure of the flight control system occur,
sooner or later a significant change in altitude
and/ or airspeeds is bound to occur (probably
sooner). Exactly how long that is depends on
the airplane and circumstances, but FAA
standards call for only three seconds.
Part of the certification process of a flight
control system involves flight tests in which
failures are imposed on the system and a FAAcertified test p ilot employed by the
manufacturer deals with them. According to
Kevin Jones, a spokesman for Century Flight
Systems, Inc., the test pilot waits three seconds
to react (measured by stopwatch), and t he
deviation from normal flight experienced in
that time is recorded and ultimately winds up
in the airplane's flight manual.
�Aviation Safety Digest
If you are not el igible for a free issue, or if you would like additional copies of the Digest:-
144
I
!
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NII.. J)l~l~l~C~'l'S
The three-second delay is meant to simulate the
time it would take a pilot, once he has noticed
the problem, to decide on a course of action and
perform it. It is measured not from the time the
failure is instigated, but rather from the time
the test pilot first notices it. Determinations of
exactly when the problem becomes noticeable is
left to the test pilot.
Failure tests are also performed with the
airplane in approach configuration, but here the
delay before action is taken is only one second.
This is based on the heightened awareness a
pilot supposedly has during this phase of flight,
said the manufacturer.
Under ordinary circumstances, a pilot should
have no difficulty in reacting to a systems
failure in the time allowed. However, should he
fail to do so in the flight-tested three seconds
(or one second), he has entered a realm of flight
where it is not really known what the system
will do.
Sneaky pitch trim
One malfunction theme that shows up
consistently in the accident record stems from
the way some autopilots control the pitch of the
airplane. In general, autopilots control pitch by
moving the elevator itself. This works well, as
long as the airplane is trimmed properly; an
out-of trim condition will overpower the
autopilot's clutch and allow the airplane to
climb or descend.
But in airplanes equipped with electric trim the
autopilot also has control of the trim
mechanism. It will sense whether or not
constant pressure is being applied to the
elevator in order to maintain altitude and
interpret it as an out-of-trim condition, running
the trim motor to correct it.
A system failure in an airplane without autotrim can very easily be overpowered by the
pilot. With auto-trim installed the pilot may be
able to overpower the elevator clutch, but the
trim motor may still continue to run, causing a
real problem. It is for this reason that 'fail-safe'
trim interrupt switches are installed on these
autopilots.
Using electronic switching, the autopilot can
perform self-checks of the auto-trim system, the
gyros, the altitude information provided by the
static system, and sensing of correct electrical
power input. When the self-check turns up
something amiss, the autopilot can shut itself off.
Yet, despite trim interrupt switches and
automatic interrupts, runaways still occur.
Unless the pilot realizes fairly quickly that he
needs to shut off the electric trim and retrim
the airplane by hand, he may find he is about
to either exceed Vne or stall.
'Runaway trim in an airplane equipped with an
electric trim system is one of the more insidious
failures,' said Century spokesman Jones. If the
pilot fails to catch the trim problem in time, he
may not be able to deal with it at all. It may
take both hands and all his strength just to
hold the control wheel. Many small planes have
enough trim authority that a typical pilot may
not be able to hold the airplane in straight-andlevel flight against the trim if its run up against
its stops.
To see what level of force is involved in
fighting against unwanted trim, we took up our
Mooney and tried to maintain straight-and-level
flight while cranking in trim. At about 125
knots (close to turbulence-penetration speed),
there was no way to reasonably hold the
airplane level after the trim had passed a point
about two-thirds of the way to the stops. A
runaway electric trim condition could reach this
point in considerably less than a minute. At
higher speeds, even less deflection would be
needed to produce a serious problem. Although
there are safeties built into the system to
prevent a runaway from happening, these may
not always work, as evidenced by reports of
the condition occurring. The trick is to catch a
trim imbalance and correct it before it is too
late, regardless of its source.
'Main strength'
An accident that graphically shows the danger
inherent in a runaway trim situation occurred
on May 26, 1984 Birmingham, Alabama. The
pilot, an instrument-rated doctor with 350 total
hours, 305 of which were in type, was killed
when his Beech A36 Bonanza dove into the
ground.
The accident came just a few minutes after
departure. The pilot's final transmission to
controllers indicated he thought the problem
was with the autopilot. 'I'm over here on
Fayette heading this way', he said . 'My, uh,
automatic pilot is stuck. It's taking main ·
strength to hold it. I'm heading back to
Birmingham... How about, uh .. . talking to
somebody that knows about a Bonanza to see
what I can ... to see what I can ...'
The Bonanza crashed seconds later. Witnesses
reported seeing the airplane nose over in a
broad arc and dive vertically to the ground. The
attitude at impact was slightly beyond vertical.
At the scene, investigators found the Bonanza's
trim tabs in the full nose-down position,
indicating the possibility of runaway trim.
The autopilot, a King KFC-200, had been
malfunctioning prior to the accident. A pilot
who flew the Bonanza the day before the
accident said the autopilot would not disconnect
by using the OFF switch. The accident pilot had
aborted a flight earlier that day due to 'HSI
problems.'
Four
..,
iSSU8S
$A 14.00
AVIATION SAFETY DIGEST reports incidents, recounts
stories, relays technical information, represents the pilot
and others involved in aviation, and, to the extent that it
falls short of being a legal document, reflects the viewpoint of the CAA.
We have noted previously that regulation alone may well
have been exhausted as a means of reducing accidents.
This is not to say the CAA is on autopilot - there are
moves afoot to make CARs, CAOs and subsidiary legislation more user-friendly (or at least, somewhat simpler).
Although an aviator will always benefit from reading about
another's brush with disaster, we are all fortified in the diligence of our personal pursuit of safety by the knowledge
that there are a lot of fellow flyers who think twice - nay
three times even - before committing themselves (and
their passengers - never forget the pax) to operations in
(inctudingsurtacepostageJ
marginal conditions. Self-discipline, mechanical reliability
and the correct application of hard-gained expertise are
but the three leading links in the chain of circumstances
that define a truly successful flight.
The wide range of submissions that cross the editor's
desk are testimony that 'marginal conditions' cover practically everything. There are a million articles out there in
the real world, and a zillion incidents (99% of which you
wouldn 't dream of putting your name to - that's OK,
we'll respect your desire for anonymity). So why not share
your hard-earned lessons? As I said, your story is unique!
To be part of this accumulated wisdom, those with an
interest in flying, be it as a professional or paid-for-byyourself, will do themselves a favour by reading the Digest
on a regular basis; if you do not obtain a free copy, the
subscription form is, as they say, overleaf.
------------------------------------------~--
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
G.P.O. Box 367
CANBERRA A.C.T. 2601
Australia
Aviation Safety Digest 144 / i
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b. Antibiotics: The most commonly prescribed groups of antibiotics are, tetracycline,
penicillin and its derivatives and the erythromycins. Most individuals find that they
can take a course of antibiotics without the drug having any effect on their well
being, or their ability to work. The most important problem when antibiotics are
being used is the underlyin~ illness which has required their use. If this problem is
not such that it causes incapacity of any sort and provided the first dose of
antibiotic is not taken on a day during which the individual wishes to operate an
aircraft then these drugs may prove to be compatible with flying.
c. Sleeping Drugs: From time to time individuals may go through a phase of having
sleeping difficulties. In situations such as this, it is not uncommon to have sleeping
drugs prescribed to help achieve sleep. The problem with many of the older
generation of sleeping drugs is that they remain in the body and have a slight
residual effect well into the next day. This situation is not compatible with air crew
duties. Fortunately here are available newer generation drugs which have a very
short half life in the body. The effects of these drugs have completely gone 8 hours
after taking the drug. These drugs are short acting benzodiazepines such as
Temazepam and Triazolam. Sleeping drugs should not be relied upon for sleep on a
long term daily basis.
d. Tranquillises and Antidepressants: These drugs by their very nature act to slow
down reaction times, and allow the individual to take a more relaxed and casual
attitude to all things. The attributes of this group of drugs do not relate well to air
crew duties. Your Aviation Medical Examiner's opinion must be sought regarding the
use of these drugs whilst flying.
e. Stimulants: Most stimulants are now not available either over the counter or on
prescription. The reason for this is that despite keeping the individual awake, they
effect the decision making process, causing over confidence, tremors, anxiety, and in
some cases bizarre hallucinations. Their use is not compatible with air crew duties.
ASO 142 carried an article on the possible results of the ingestion of certain substances. The burden of the
message was 'Be aware; check your reactions!'. In an expansion of the discussion, the Director of Aviation
Medicine here tells us of the sort of thing aircrew particularly should look out for.
~
~ Food, Drink, Drugs, Illness and Flying
N THE SPRING issue of the ASD, an article was printed quoting anecdotal evidence
concerning the use of the non-sugar sweetener aspartame. The tenor of the article was
that the use of sweeteners containing this substance would on some occasions be
associated with effects which could incapacitate an individual. The fact is that there is
no clinical medical evidence to support this view. The article however, raised a hornets
nest of questions and dogma about food, drink, medical drugs, illness and their effects
on the pilot.
The problem with the human animal is that the only thing that we can be sure of
medically is life and death. Between those two extremes there are no absolute
certainties just many shades of grey. To say that a drug will cause unpleasant side.
effects on everyone is just as wrong as to assume that another drug will have no side
effects on any user. We all know of people who only have to take an aspirin and it can
almost kill them or an orange or chocolate may effect another with incapacitating
migraine. Yet most of the population happily take aspirin and chomp chocolates and
oranges with pleasurable indifference.
Similarly the effects of illness and injury vary from individual to individual. A problem
which leaves one individual moribund in bed may leave another feeling well enough to
work. This individual variation in the effects of foods, drugs, illness and injury is no
indictment of the individual but is a characteristic over which the individual has little
control.
In most forms of recreation or occupation it is of little consequence if an individual is
feeling below par because of food allergy or the effects of illness or drugs to treat that
illness. In aviation however there is no place for individuals attempting to operate
aircraft when they are distracted by anything which effects their well being and ability
to concentrate.
When the treatment of an illness or injury involves the taking of medication, whether or
not these drugs are prescribed or purchased over the counter, the fact that undesirable
side effects are not mentioned is no assurance that the individual will not experience
some side effects. Equally if an individual is dieting or materially altering the food and
drink from that which is normally consumed, in some small percentage of people some
adverse effect will be experienced.
This leaves us with the fact that because of individual variability nothing can be
assumed to be without some form of deleterious side effect. The only sensible path for
any aviator is to make sure that no first time drugs, food or drinks are consumed when
aircrew duties are anticipated.
I
The following is a guide regarding several of the more commonly consumed drugs.
Antihistamines: These drugs are prescribed for allergic symptoms. The most
common condition for which they are prescribed is seasonal hayfever. Many over the
counter preparations for the treatment of the common cold also contain an
antihistamine along with other preparations.
The most frequent side effect noted with these drugs is secfation, however they can
also cause a dry mouth and difficulty with focusing. There are available now newer
generation antihistamines which as a rule do not have any side effects. These are
Terfenadine and Astemazole.
f.
= ~
@'--------'*
Antihypertensive Drugs: Drugs used in the control of blood pressure do not usually
cause any problems, or effect an individual's performance. Apart from the usual
caution of not participating in aircrew duties whilst becoming established on the
drug, and clearing its use with your Aviation Medical Examiner, the drugs are
generally quite compatible with flying.
g.
::::::;=
:::=::;: ....,._
~~
Alcohol: The use of small quantities of alcohol as a social drink has not been shown
to have any significant deleterious effects in most people. Alcohol is a tranquilliser
and sedative, and is not compatible with air crew duties. Fortunately alcohol is
fairly rapidly dealt with by the body and provided at least 8 hours pass after
moderate alcohol consumption there should be no residual effect. This is not the case
after heavy alcohol consumption, and a period of at least 12 hours should elapse
before flight crew duties and even this length of time may be insufficient for certain
effects to cease. Attention should be drawn to the deleterious effects of long term
heavy consumption, and the high incidence of alcoholism amongst regular heavy
consumers.
An individual starting a course of drugs or changing diet significantly, should always
enquire as to whether this activity is compatible with aircrew duties. If the answer is
yes that is still no assurance that there will be no side effects. The most reliable
indication as to the effects of any medication on an individual is how that individual
feels in the hours following the taking of the drug. Common sense dictates therefore,
that when anything different in the individual's diet therapy is being commenced, wait
at least 24 hours before commencing aircrew duties.
Finally the salient point remains: that it is the responsibility of the licence holder to
approach the problem of fitness to exercise the privileges of a licence in a mature and
sensible manner and to err on the side of safety if there is ever any doubt.
~=
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= ~
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~~
Dr R W Liddell
=~
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iv/ Aviation Safety Digest 144
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Aviation Safety Digest 144 / v
�Accident and Incident Response
Examination of the flight data recorder information has shown that the aircraft was in a landing
configuration and aligned with the Bruce Highway. It was subsequently descended to 168 ft '
(radio altimeter) on a heading of ISOM, the same heading as the highway, and that the CAS was
reduced to 137kt. Witness reports confirm that the aircraft was flown over the highway in a
southerly direction at a very low altitude.
Beech 95-C55, 25 July 1988
After all attempts to extend fully the nose gear failed the aircraft was landed on a grass runway
with the nosewheel some 20 from the locked down position. During the landing roll the nosegear
collapsed and the aircraft settled on its nose.
Prior to making the approach and landing, the pilot said he had shut down the right engine and
feathered the propeller, which was then parked in a horizontal position. On short final, the left engine was shut down and the propeller feathered. Insufficient time was available to park the
propeller, which struck the ground in a vertical position. The left engine crankshaft fractured rear
of the propeller hub mounting.
BAS/ recommendation
An inspection of the area surrounding Mackay Airport and the Bruce Highway was carried out in
an attempt to ascertain if there were-similarities between the runway and the road. Runway 14 is
1981 metres long and is lit by side variable-intensity white lights 65 metres apart. The runway is
also equipped with T-Vasis approach lighting. The relevant part of the Bruce Highway is lit by
post-mounted street lights on either side of the road. The lights are approximately 30 metres apart
and run for a distance of about 1200 metres before becoming a single row of lights. The northern
end is flanked either side by two 24-hour service stations. These provide an intense pool of light
on each side of the road. There was no similar lighting on the threshold of runway 14, nor does
any lighting on the highway resemble T-Vasis.
It is apparent that the pilot flying the aircraft at the time (the captain) misidentified the highway as
Mackay runway 14.
The actions of the pilot, although done with the best of intentions in shutting down both engines
priot to landing, be the subject of a report in the ASD. The report should highlight the dangers involved in this practice, both airborne and after touchdown.
The flight crew declined to make themselves available to the investigators for interview, apparently under direction from their industrial association. This action by the crew hampered the investigation and resulted in the reasons for the misidentification not being determined.
Significant factors
The Authority agrees with the BASI opinion; we accept the recommendation, and this sort of pilot
action will be discussed in our new safety promotion video, currently in production, entitled
'Going Down - a guide to in-flight emergencies'.
The following factors were considered relevant to the development of the incident:
1. The pilot flying the aircraft misidentified part of the Bruce Highway for Mackay runway 14
2. Neither pilot became aware of this error until late in the approach to a landing
BAS/ recommendation
Boeing 737-376, 14May1989
On descent to Mackay the pilot was instructed by the Tower to make a Dl\-1E arrival and to report
at 10 Dl\-1E. He was advised that there was a shower at the field, moderate rain and that the
visibility was about 6000 metres. A few minutes later the Tower con_troller indicated that the
weather was improving and the showers were mostly to the SW of the field. He then gave the
pilot a choice of left- or right-hand circuits and advised that there were a few patches of low cloud.
Two minutes later the pilot advised he would be making a left-hand circuit for R/W 14 and was instructed to report on final. Approximately one-and-a-half minutes later the controller asked the
pilot to confirm that the aircraft was making a missed approach. The response from the pilot was
'Negative'. Following this the controller advised that the aircraft was very low to the west of the
aerodrome and suggested that a climb should be commenced. The pilot later reported that he had
the runway in sight and would make another approach. A left circuit was carried out for runway
14 and the aircraft landed without further incident.
That the CAA should take immediate steps to survey the lighting situation at Mackay in order to
establish whether corrective action be required to prevent a reoccurrence of this nature.
The survey has taken place and a recommendation has been made to OTC for the inclusion of a
modified simple approach lighting system in the Consultant's master plan for the redevelopment
of Mackay aerodrome.
Aviation Safety Digest 144 / vii
vi / Aviation Safety Digest 144
..
�Aviation Safety Digest
144
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NOTE : NOTAM CLASS 1 AND CLASS 11 ARE TO BE READ JN
CONJUNCTION WITH THE ABOVE DOCUMENTS
ISSUE: 9
DATE: 08 FEB 1990
viii/ Aviation Safety Digest 144
NII.. J)l~l~l~(~'l'S
The pilot's brief radio transmission suggests he
thought he was fighting the autopilot, not the
airplane's trim condition. While the autopilot
might have caused the t rim condition in the
first place, the key to recovering was to shut
off the electric trim system and correct it
manually, which he apparently never did. He
h ad only moments to realize the true situation
before the airplane was headed straight
towards the ground.
Coupled with this was the known problem with
shutting the autopilot off in the normal manner,
further complicating the s ituation.
Part of the investigation into the crash involved
tests of the autopilot installation. NTSB
investigator Preston Hicks said that though
tests of the autopilot computer were attempted,
it was too badly damaged to learn anything
from. 'In fact, we blew the test rig out trying,'
he said. Hicks further noted that the pitch trim
servos and sensor microswitches appeared to be
serviceable at the time of the accident.
NTSB's probable cause statement highlights the
pilot's failure to deal properly with the
situation. Listed among the probable causes
were failure to understand the proper remedial
action to take, failure to correct the trim, and
failure to correct the autopilot.
The King KFC-200 has also been implicated in a
number of other incidents involving altitude
hold problems . In one particularly ironic case ,
the pilot of a V35 Bonanza wrote a letter to the
NTSB about two weeks after the Birmingham
crash. It detailed problems he was having with
his autopilot.
'The problem would occur only occasionally and
without prior warning. Each time it happened,
the autopilot was engaged in straight-and-level
flight , and the airplane would suddenl y begin
nosing over in an ever-steepening dive.'
Three-and-a-half months later, the Bonanza
broke up in flight over South Carolina. Again,
tests of the autopilot were inconclusive because
of damage, and the probable cause statement
does not mention the autopilot as a factor in
the case.
It is important to note that there is no d irect
eviden ce specifica lly implicating the autopilot
in this crash as there was in the Birmingham
incident. Further, the crash occurred before the
Bonanza tailmod AD was issued. None the less,
lawsuits were filed against both King and
Beech , and both companies settled out of court.
The KFC-200 has historically had some troubles
with its altitude-hold function, some of which
were traced to the altitude-hold printed circuit
board in the computer, one of the first built
with a solid-state barometric pressure sensor.
The company received several complaints about
airplanes that would wander up and down
when the altitude-hold function was engaged .
The SDRs contain numerous complaints of
altitude-hold problems.
Is it off?
When the automatic interrupts do function
correctly, it is often up to the pilot to determine
if the autopilot has packed it in. In most cases
this is obvious , but some installations and
circumstances effectively require that the pilot
look directly at the autopilot control to
determine its status.
One pilot we interviewed has occasional
failures of his autopilot that have been so
persistent he now treats them as routine. He
says his installation (a Century IV in a Beech
Baron) will give uncommanded pitch changes in
cruise. 'You'd be on altitude hold and for some
reason the autopilot starts trimming against
itself. All of a sudden it'll shut itself off,' he
said . 'I re-engage and there's no problem.'
The trouble is , the autopilot control panel is
located low and to the left on the instrument
panel, and the indication of whether the unit is
on or not is a light that reads either ON or OFF.
'It is just a short word beginning with 0 . Unless
you are looking at it, it is easy to miss. This is
rather insidious, because the airplane will start
to drift off altitude without the autopilot
engaged. ' He commented that a warning horn or
prominent light would would alleviate the
problem.
Interestingly, Century's Jones mentioned that
the manufacturer is installing just such a horn
in its new autopilots . It is also worth noting
that most airline installations have an autopilot
disconnect warning horn.
Forced runaways
Century's Jones outlined a scenario where a
pilot could get trapped by an autopilot's
automatic trim control that is working properly
if he reacts to the system in the wrong way. If
the pilot moves the wheel against the autopilot
for more th an three seconds, the system will
'think' that the airplane needs to be re-trimmed
to maintain normal flight , according to Jones.
This might happen in any number of ways. An
unwitting passenger may use the yoke as a
handhold, or the pilot may accidentally push
against it while digging something out of the
back seat. The system will t rim against the
force being applied to t he wheel, 'thinking' that
it is a result of normal feedback from the
control surface. The pilot may interpret this as
a problem with the a utopilot, and pull (or push)
harder, while the autopilot continues t o run the
trim. Or he may have forgotten that the
autopilot is engaged and attempt to manoeuvre
the aircraft, interpreting the resistance he feels
as a problem with the control system itself.
�Aviation Safety Digest
144
Aviation Safety Digest
144
NII~ J)l~l~l~C~'l'S
After a few seconds the pilot realizes he is
fighting the autopilot and turns it off, only to
discover that he is still wrestling with a badly
out-of-trim airplane. He may well interpret this
as failure of the autopilot to disengage, since
the controls do not feel any different. Believing
the autopilot is causing his problem (when it is
actually the trim), he may to try to
troubleshoot the autopilot and ignore the trim
until it is too late to recover.
Aviation Safety tried fighting the autopilot in
our Mooney and found a couple of things. First,
it is unlikely a pilot would get into too much
trouble in this way unless he were well and
truly confused about what was going on. The
force pushing against the wheel becomes
noticeable before the airplane gets very badly
out of trim.
Second, once the force does become noticeable,
the inclination of the pilot is to relax
somewhat. The trim condition the airplane is
now in produces a very sharp, surprising (and
disorienting) acceleration 'spike' as the airplane
assumes its new attitude. (We only tried this
with the autopilot commanding nose-up trim,
feeling it unsafe to experiment with strong
nose-down trim forces.)
While, in our opinion, it is unlikely a pilot will
try to fight the autopilot for very long, it does
happen. A 1977 accident is a case in point. The
pilot was making a coupled IFR approach at
night into Ypsilanti, Michigan. During
go-around, he inadvertently tried to manually
control the pitch of the airplane with the
autopilot still engaged. The autopilot eventually
was disengaged, but by this time it had cranked
in full nose-down trim in response to the pilot's
nose-up pressure on the controls. The result:
The MU-2 hit the ground short of the runway,
seriously injuring both pilots.
Control consistency
Other traps involve the ergonomics of the
autopilot installation. There have been several
cases in which pilots got into trouble because
they were not thoroughly familiar with the
operation of their autopilots, sometimes
stemming from poor or inconsistent layout of
the controls. In one case, problems related to
the pilot's operation of an autopilot led to an
emergency Airworthiness Directive on the
Mitsubishi MU-2.
A series of incidents, two of which occurred in
June, 1986, disclosed a problem with the
autopilot control locations in different
Mitsubishis. The first, a fatal accident, involved
an apparent malfunction of the autotrim
system.
The accident happened during a priority mail
flight that had departed from Austin, Texas
just minutes before. The sequence of events
illustrates the short time available for action
when a failure is experienced in the flight
control system.
Six minutes after takeoff, the pilot, a 5,268hour ATP, reported level at 9,000 feet. One
minute, 44 seconds later, the pilot reported
trouble with the autopilot, saying he could not
control or disconnect it. 'It is trying to pitch me
nose-down,' he said. Fifty-seven seconds later,
he said, 'It's descending at 6 ,000 feet per
minute and I can't control it.' A company pilot
in another airplane asked if he could find the
autopilot circuit breaker, to which the MU-2
pilot replied 'Call you back.' Moments later,
radio and radar contact were lost.
The Mitsubishi impacted in an inverted,
45-degree nose-down attitude at an estimated
400 knots. The total time from the pilot's first
report of difficulty to his last transmission was
only one minute and ten seconds. The
destruction of the aircraft precluded a
determination of just what went wrong.
The other June, 1986 incident was much more
illuminating. An experienced MU-2 pilot
experienced runaway nose-up autopilot trim on
takeoff, nearly causing a crash. He was able to
regain control of the airplane after pulling the
circuit breaker on the Bendix M-4C autopilot.
Even though the pilot had roughly 4,000 hours
in the MU-2, investigators learned that he was
mistaken about the function of some of the
autopilot controls, notably the red yoke button.
Some of the installations had the yoke-mounted
disconnect switch placed on the right horn of
the control wheel, thus requiring the pilot to
take his hands off the throttles to disconnect
the autopilot - potentially disastrous during a
go-around from a coupled approach.
The FAA ultimately issued an AD(88-13-01)
that standardized the location of autopilot
switches on MU-2s. Compliance with the AD
also involved functional tests of the various
ways to disconnect the electric trim system.
Shut it off!
There are many ways in which a pilot can cope
with mechanical failure of the autopilot or its
related systems. Aside from the on/off switch
on the unit, there is usually at least one other
switch on the yoke, a temporary override (also
on the yoke), the avionics power switch and/or
the master switch, and the autopilot's circuit
breaker. Some airplanes, notably many Pipers,
do not allow the option of 'pulling the plug' by
yanking the drcuit breaker, since they are
NII~ J)l~l~l~C~'l'S
equipped with non-pullable breakers. In
airplanes with electric trim, there is a separate
switch for the trim circuit. As a last resort,
there is also the possibility of physically
overpowering the autopilot, though this carries
with it a whole extra set of difficulties in
certain cases.
Post-crash analysis of radar data showed that
the Mitsubishi was maintaining a constant
altitude for the two minutes before it entered
the spin. During this time it steadily
decelerated from 180 to 120 knots. At the
accident site, the airplane's elevator trim was
found in a 13-degree nose-up position.
Brittain autopilots are very different, however.
Since they are entirely vacuum-driven, none of
these shut-off procedures apply. According to
Brittain vice-president Gerald Walters, the only
way to shut off a Brittain autopilot is by
opening the master cut-off valve. There is no
backup system.
NTSB concluded that the crew reduced power
to slow the airplane on entering tur bulent
condition. As they did this, the autopilot
steadily commanded nose-up trim to maintain
altitude as it was programmed to. When the
crew advanced the throttles after reaching the
slower speed, the trim setting caused the
Mitsubishi to suddenly pitch up, roll over, and
enter a spin.
Getting the autopilot turned off quickly can be
a real problem, sometimes. A good example was
the hard landing of a Beech C90 King Air in
January of 1986. The pilot was flying a coupled
approach into Akron, Ohio using a Sperry 200
autopilot. The airplane broke out of the clouds
at only 300 feet agl and the pilot hit the
disconnect switch.
According to the pilot, the autopilot failed to
disconnect, and he spent the remaining few
seconds of the flight t r ying all the various ways
built into the system to shut the autopilot off.
He did not make it through the complete list
before impact.
An interesting aspect of the accident is that
part of the emergency checklist calls for pulling
the autopilot circuit breaker. On the King Air,
however, the breaker is located on a crowded
panel on the far side of the airplane's 52 inch
wide cockpit, and it is debatable whether or not
the pilot could have sorted out its location a nd
r eached it in time.
After the accident, neither a local avionics shop
nor Sperry could recreate the failure, and its
cause was never determined.
The weak link
Perhaps the weakest link in the au topilot
system is the human pilot. Although the
autopilot is functioning correctly, the human
pilot's lack of knowledge or understanding of
t he system can be the source of problems.
Operated incorrectly, 'George' can fly the
airplane into a corner.
For example, there was the Ma rch 5, 1986
crash of a Mitsubishi MU-2. The two-man crew
and three passengers died when the airplane
entered an uncontrolled spin from cruise flight
at 4,000 feet over Eola, Illinois. The flight was
on an IFR flight plan, and weath er conditions
included turbulence and icing. The 4,590-hour,
ATP-rated pilot in command had logged some
180 hours in the MU-2.
The Board, in its probable cause statement said
that t he crew was not paying attention to what
the a utopilot was doing to the airplane as they
were slowing down. Fatigue was also cited as a
factor - the crew had been on duty 11 hours
that day. The autopilot itself was not at fault
- the crew had fallen into a trap by not
t hinking of what the autopilot would do in that
situation.
Know thyself
Unfort unately, proper use of autopilot,
including recognizing failures and dealing with
them, is rarely t aught. Most pilots wind up
learning how the system works by a kind of
self-teach method.
'The biggest weakness in the system is that
people do not fully understand the information
in the autopilot flight manual supplements,'
said Century's Jones, point ing out the
supplements contain information on exactly
what the autopilot will do if various
malfunctions occur (the results of the 'three
second' flight tests noted earlier). Other
manufacturers agree. 'The number one problem,
of course, is a lack of understanding on t he part
of the pilot,' said Brittain vice-president Gerald
Walters. 'This includes things as simple as
shutting the system off.'
'You have got to realize that if you are going to
give control of the airplane to an automatic
device, you need to know ever ything t h ere is to
know about that system and how it will react,'
Jones said.
'A lot of people move up into an airplane with
a sophisticated autopilot, but nobody ever
really teaches them anything about it,' he
continued. 'They wind up learning by
experiment, but never go beyond finding out
how to do the basic things they want it to do.
They never learn what will happen if s omething
goes w rong, or how to deal with it.' D
�Aviation Safety Digest
144
Answers to the quiz
Al.
Yes, provided it is for less than 10 seconds; any
longer requires prior notification [AIP /SAR-29.4.l(d) (e); VFG Safety 3-3(d)) With the advent
of AUSSAT and its ability to 'fix' transmissions
it is even more important not to start the SAR
authorities on a wild goose chase.
A2.
All FULLSAR aircraft and aircraft wishing to
cancel SARWATCH at this time. Call is:
'(callsign) Circuit area (aerodrome), Runway
(number of runway or direction intended to be
taken for landing)'.
Additionally, 'Cancel SARWATCH/Report after
landing/ETD for SAR' (as appropriate).
Reference AIP RAC/OPS-0-86.13; -1-35, -1-36,
NOTE 1; -1-111.3.3; -1-112.3.4.
A3.
(a) No. Neither the Civil Aviation Regulations
nor the Civil Aviation Orders specifically
prohibit NGT VFR when more than 4/8
cloud is forecast to exist below LSAL T +
500', but AIP RAC/OPS clearly disallows it in:
• 1-11.1.3.4 concerning flight-planning;
• 1-43.6.4 concerning LSALT for NGT VFR;
and
• 1-45.7.3, plus 1-45.8.2.1.3 and 4
concerning route specifications and
navigation by visual reference to ground
or water.
(b) Yes. The primary reference is CAO
20.8.4.2.2.3.
(c) Yes. AIP RAC/OPS-1-14.4.1 refers.
(d) Yes. CAO 20.8.4.2.2.3 states that 'a flight
under the Instrument Flight Rules ... s h all be
p lanned on the basis of executing an
instrument approach at its destination for
all operations at night ... '. With failure of
the aircraft's DME, the DGV NDB/DME IAP
cannot be used. The pilot is obliged to plan
another destination.
(e) Yes. Failure of the aircraft's DME does not
prevent the flight from continuing to DGV,
using IFR procedures. A visual approach
might be possible using NGT VFR
procedures, in accordance with AIP RAC/
OPS-1-44.6.4.2. It can also be argued that a
vis ual approach is authorised by AIP IAL-23 .1.8, but a counter-argument is that the
pilot cannot use the provisions of the IAL
procedures when he is unable to execute an
instrument approach. The pilot could advise
his intentions by applying the ZZZZ
procedure described in RAC/OPS-1-12, while
actually nominating another destination to
comply with CAO 20.8.
( f) AIP IAL-2-3. l.8(b) requires the aircraft to
be established in VMC within:
• the prescribed circling area; or
• 5NM of the aerodrome, aligned with the
runway centreline and established on the
VASIS.
A4
AIRSPEED INDICATOR TABLE
MARKING
SIGNIFICANCE
Red Radial
Air minimum control speed.
While Arc
Ope rat ing speed range with wing flaps set as per Flight Manual.
Lower limit is maximum weight stallimg speed in landing
configuration. Upper limit is maximum speed permissible with
wing !laps extended as per Flight Manual.
Green Arc
Normal operating range. Lowe r limil ts maximum weight stalling
speed with flaps & landing gear retracted. Upper limit is maximum
slructura l cruising speed.
Blue Radial
One engine inoperative best rale -<>f·climb speed at sea level
Sl~ndard da y condhions & weight as per Flighl Manual
Yellow Arc
Caution range. Operations must be oonducted with caution &
only in smooth a ir.
Red Radial
Maximum speed tor all ope rations
A5.
(d) , reference AIP/ MET-0-6 and VFG 40.4.
A6.
Pilots engaged in a stepped climb/ descent shall
adopt the following procedure:
• the pilot in command of the lower aircraft
shall report approaching each assigned leve l
in the sequence; and
• the pilot of the higher aircraft, on hearing the
lower a ircraft approaching each assigned
level, shall report his last vacated level, thus
providing ATC with the next level for
assignment to the lower aircraft (reference
AIP RAC/OPS-0-20. 10.2.3 and 3.1). D
1.-EAlZN
l'o t=i..Y
t...ASI
fl...IG+\T
FRE:E:
~-
National
Aeronautical
I nformation
Processing
System
AIPS, which will provide an automated
pre-flight briefing and flight-planning
system for the Australian aviation
community, is expected t o be fully
commissioned during 1992.
The system will assist pilots in flight-plan
(FPL) submission by:
• providing a Specific Pre-Flight Information
Bulletin (SPFIB), containing aeronautical
information (NOTAM) and meteorological data
directly relevant only to the route submitted;
• allowing the pilot to enter the FPL by
electronic or manual means, and, if required,
storing route details for subsequent use;
• validating the FPL against regulations, orders,
instructions and operational requirements
currently applicable to the type of flight and
aircraft; and
• providing the pilot with an SPFIB update and
a FPL printout.
SPFIB will be produced by reference to either a
published or non-standard route and will take
into account all relevant briefing data within an
envelope commencing 25NM before the
departure airfield, extending 50NM either side
of track and finishing 25NM beyond the
destination.
To minimise input required from the pilot,
NAIPS will work from a comprehensive
database, containing not _only t ime-critical
details of NOTAMs and weather, but also items
such as airways system data and information
on aircraft equipment and performance.
N
There w ill be a variety of ways that you can
access the system:
• face-to-face briefings at CAA-manned Briefing
Offices at SY+ BK, BN + AF, PH + JT, DN,
ML + MB, and AD + PF. Each of these will
also have computer terminals for direct pilot
access.
• direct pilot access via remote briefing
terminals located at:
(QLD) Bundaberg, Mt Isa, Cairns, Coolangatta
Mackay, Maroochydore, Townsville and
Rockhampton.
(NSW/ ACT) Canberra, Coffs, Pt Macquarie,
Tamworth, W agga, Albury and Broken Hill.
(VIC/ TAS) Hobart, Launceston, Essendon and
Mildura
(SA/ NT) Alice Springs and Gove.
(WA) Derby, Karratha, Kalgoorlie, Kununurra
and PT Hedland.
• suitable privately-owned computers linked to
NAIPS, either directly or via dial-up modems.
Compatibility details should be available
mid-1990.
• Telephone facilities for those pilot~ w ithout
access to face-to-face or computer briefing
• Centralised Brie fing Units (CBU) located at
BN and ML, accessible via 008 numbers for
long-distance calls. In general, BN CBU will
service the north-east portion of Australia,
and ML CBU will cover the south-west and
south-east of the country. Computer-generated
voice briefings will be a feature of these
services.
• Access to manned Briefing Offices on local
matters will be available v ia a local phone call.
Apart from provis ion of appropriate computer
systems, a strategy to ensure that NAIPS
provides an efficient service from day one
includes:
• the establishment of a group of industry
representatives, through the Australian
Aviation Advisory Committee and the
National Airspace Users Advisory Council, to
protect the customer's interests;
• the development of an integrated marketing,
PR, educational and t raining plan to fully
prepare some 60 OOO users for the
introduction of the system; and
• close liaison with the FAA, to glean as much
informat ion as possible from the US Direct
User Access Terminal project.
A pictorial representation of the NAJPS set-up
i,s on the back cover D
�Aviation Safety Digest
144
Aviation Safety Digest
144
'iit!J[5G5 R505U5N5D:==T50:==A51R:==:==
Squawk ... and be
seen!
altitude information, including level changes,
on all aircraft being provided with a service
(Figure 1). As a bonus, SSR has the ability to
identify aircraft in areas where primary radar
cannot reach.
In relat ion to any emergency the pilot may
experience, the SSR emergency codes, when
selected, provide an aural and visual alarm at
any ATC centre receiving t he signal. For
example, a pilot with radio failure can squawk
the appropriate code - they are listed in AIP I
ERSA - and a large 'R' (bright display) or
'RAD' (synthetic display) is shown on the radar
screen (Fig 3) to draw the controller's attention
FIG. 3
BRIGHT
R
Bernie Rodgers, Air Traffic Procedures Section, Canberra
Additional information given by SSR Transponder for
both the older "bright" & more modern "synthetic"
displays.
ECENT legislation requires pilots who wish
to fly in controlled airspace within radar
coverage to have serviceable transponders
fitted in their aircraft. This article explains the
way in which transponder information is used
by ATC.
SSR is passive radar; that is, the pilot activates
a signal that is sent out from the aircraft and
received by a ground station that is 'listening'
only. Unlike primary radar, SSR ground installations do not send out any 'active' signals.
In most cases, an aircraft flying in controlled
airspace within radar coverage will be
instructed to 'squawk' a particular four-figure
code. This assists ATC to identify and
subsequently track the aircraft, and so facilitates provision of radar control services. This
code is allotted to the aircraft callsign when the
flightplan is received by the relevant control
centre, and the four-figure group is noted on
the ATC flight strip for controller reference (a
'flight-strip' is in this case a strip of card with
various aircraft/flight details marked upon it).
At this stage the pilot neither knows, nor needs
to know, the code allocated to his flight.
In the ATC centre the four-figure code is
entered into a computer, along with the aircraft
callsign, so that when a pilot responds to the
instruction to 'squawk' that code the computer
expects that particular response and recognises
it as having been allotted to the aircraft. The
appropriate information is then displayed on
the controller's radar screen.
When an aircraft is given a SSR code (either on
taxi if at a controlled aerodrome or with the
airways clearance if entering controlled airspace from OCTA), the pilot selects the fourfigure group in the display box in the cockpit.
The resultant display on the radar screen will
be the aircraft callsign (Mode A) and altitude
(Mode C). This information, together with a SSR
position symbol, is displayed next to the primary paint. Thus ATC can view callsign and
BRIGHT
SYNTHET1C
+••
R
•
BR1GHT
SYN THETIC
BRIGHT
C)A3C
OABC
.Q.ABC
0
0
0
-E7 poo
•
••
(White slash on a
green screen)
E9ABC
090
.Q.
E7
Mode ·A·
Primary Radar
SYNTHETIC
••
•
Mode "C"
(Callsign plus
Altitude)
In this case 90001!.
(Callsign Only No
Primary Paint)
New-generation radars being installed in Australia over the next few years will be reliant on
SSR as the principal means of identification and
tracking in the en-route phase of flight. Consequently, the use of SSR transponders will
become more and more important for flights in
controlled airspace.
As can be seen, the more information that can
be acceptably shown on the radar screen (too
much causes clutter), the easier it is for ATC to
identify and keep track of each aircraft. Using
primary radar alone makes the identification
process cumbersome, needing a radar vector or
DME distance check and requiring on the part
of the controller time and effort which would
be better spent on other duties.
As a check to ensure that the squawk is from
the correct aircraft, and not the result of some
other pilot who has by chance activated the
same code, ATC will often ask for a 'squawk
ident'.This will cause a triangle to appear over
the primary paint (bright display) or the symbol to flash (synthetic display), and eliminates
the risk of a mis-ident (Fig 2).
FIG. 2
A
BRIGHT
AB C
~ ~~
Iden! Triangle
( r .".,..
'©
SYNTHETIC
ABC
Position symbol
SSR Information
~
t ~'f ;jp~
FIG. 1
Secondary Surveillance Radar (SSR) transponders
SYNTHETIC
\. I I I I'
=ABC=
Primary Paint
FIG. 4
BRIGHT
x
NAVAID
SYNTHETIC
x
+••
•
Primary Paint
(Approaching Navaid)
CALLSIGN
ALTITUDE
& " RAD"
ALL FLAS H.
Radio Fail Indication
to the emergency. An alarm bell rings in the
radar room; this can only be silenced by the
controller carrying out the correct emergency
drills. On the screen, the v isual warning continues until the pilot deselects the emergency
transmission.
The following is an example of what happens
when the pilot of 'ABC', a light aircraft
equipped with SSR Mode C, wishes to enter controlled airspace within radar coverage (Fig 4
refers):
BRIGHT
SYNTHETIC
.
)(
ABC
.:-ffi-:..
070
,\::[7,
,
'
••
SSR response
(If mode A only carried, no
altitude information wou ld
appear)
'ABC clearance: enter controlled area, track
via .... (navaid). Enter at 7000, squawk code
4321 with i dent.'
In this case, the comput er has been told t o
expect t he response of 4321 to be ABC. It recognises this response from the aircraft's transponder and displays the information received
in its correct position (next to the primary
paint if within primary radar coverage). It then
recognises the ident response and places the triangle around ABC, leaving the controller in no
doubt as to the identity of the aircraft.
There a lso exists a Mode 'S'. This is an
advanced system, fully compatible with Modes
A and C. Australia will shortly begin testing
Mode S to ascertain possible advantages; more
info on this in a later article D
Pilot contribution by M Barber
subsequently the flight commenced and
proceeded normally.
Approximately one half hour into the flight it
was considered timely to change fuel tanks. As
this was carried out the realisat ion struck
home: the fuel selector was on t h e tank found
to be 'dry' during the pre-flight inspection!
It would seem that the previous flight very
nearly terminated prior to landing - certainly
it appeared that th e pre-landing checks had
included no form of fuel management.
ERFECT weather, a good friend, and a
Piper P A28 Warrior; who could ask for
more than this recipe for a pleasant flight?
Alas, the subsequent experience was to cast a
chill over an otherwise enjoyable experience
and teach a valuable lesson.
The pre-flight revealed a very low fuel state it was not possible t o obtain any dip-stick
reading on the right-hand tank. The reading on
the left tank was minimal.
The aircraft was refuelled , both tanks being
completely filled. Since this was t horoughly
established, there was no need to make any
tank change on pre-take off checks and
Although perhaps not proof positive of slipshod
airmanship this sort of r evelation provides a
free lesson in procedure, and, since the
correspondent found it out for himself, one that
is not easily forgotten.
We had a bit of a think about this, then wrote
to Mr Barber, asking whether he had pursued
the matter. As we had hoped , and indeed
expected, the incident had been reported
without delay to the organisation responsible
for flying operati ons from that particular base.
Mr Barber reports that he has no doubt that the
pilot involved was invited to partake in an
appropriate educational session. D
What fuels
these mortals
be!
P
�and w e all know that time expands/ contracts
under intense stress), bu t it seemed reasonable
to assume that, if no electrical inj ury is
sustained at the instan t of impact, by the time
you 're jumping out the broken power line
would be carrying no charge and thus be
innocuous. Well, we ma de some m ore enquiries
of the electricity people and what do you know
- we were dead wrong! (no pun intended).
They were at great pains to poin t out that the
scenari o was a likely one, but not guaranteed.
Around Australia, there are differing
regulations about rechargin g lines.
After an automatic cut-out, a manual recharge
is attempted to establish that the fault is not
transient, then the patrol goes out to physically
locate the fault. In the country, par ticularly,
the judgement whether to manually recharge
after the automatic cut-out has operated is left
to the duty manager's discretion: it could be
anything from 5 to 30 minutes after the short.
A current affair
Extracted from a pilot contribution
.
W
E HAD A devastating accident last year,
when our beautiful Kl3, just 21 years
young, was wrecked in power lines. I'm
pleased to report it will be repaired, to fly once
more.
We have two sets of power lines marked by
large fibreglass orange spheres - these were
t he ones we didn't hit. The ones that caught us
were unmarked because they were out of the
\Vay of any 'normal' circuit. If you have any
power lines within gliding distance of your field
you should mark t hem - if not, they will
eventually trap somebody.
When we hit, the Kl3 finished up on the
ground resting on top of the two lines carrying
22 OOO volts. My pupil suffered severe
electrical burns on his ankles, the right hand
through the control column and on the back of
his neck from the steel canopy crossbar.
As he was in the front cockpit, I was aware
immediately that he was in convulsions. I
quickly got out and went to his aid. In that
short time he was unconscious and had stopped
breathing. Now, I have been farming for forty
years and would have 'pulled' about 1000
lambs, always clearing their air passages by a
finger down the throat, so it was from sheer
habit that I immediately opened Brian's mouth
and saw his tongue down his throat. I pulled it
back with my forefinger, undid the straps, but
was unable to lift him out. Working fast, and in
desperation, I gave him resuscitation by hard
pressure on the chest. At once he started to
breathe and regain consciousness. Fortunately
my crew arrived very quickly and we removed
the casualty by main force, within about five
minutes. The time is important, for two of us,
at least, knew about automatic and manual
recharging of electrical lines. We took Brian
well away from the aircraft and then to
hospital. Thankfully he is well, but has a long
recovery time from the severe electrical burns
from such a high voltage.
Very nasty - but, as the writer indicates, it
should never have happened. Let's emphasise it
once again: if you 're into low circuits,
agricultural flying, or, as a glider pilot, faced
with the ever-present possibility of an
outlanding near the circuit, you must know
where the lines are. If the cables are marked
with big orange spheres, all well and good, but,
if as usual, they're extremely hard to see, then
the responsibility's all yours: know the local
area.
We asked the electricity authority about
re-energisation and received confirmation of
points in the article. Specifically, the following
example illustrates a representative autoreclose sequence followed by a powerline
circuit-breaker:
• open - circuit breaker senses fault
• + .3 second -first reclose attempt
• open - fault is persisting
• + 15 seconds - second reclose attempt
• open - fault still there
• + 45 seconds - third reclose attempt
• open, fault diagnosed as 'permanent' and power
automatically cut off
Here, three attempts have been made to
re-energise within one minute. We have no
statistics on the time it takes to vacate a
crashed aircraft (reports are totally subjective,
Some places will not manually r echarge for a
specified time - say half an hour, sometimes
i t's as soon as the technician can r each the
switching station, per haps only a few hundred
metres f rom the sub-station.
Therefore, they say, you should assume one
thing only about power lines - they're always
live. So, if you are u nfor tunate enough to be in
an accident involving ground electricity, sit
tight un ti l someone outside confirms the
absence of electrical current. A ny need to
vacate the aircraft without delay due arcing, a
strong smell of aviation f uel or even actu al f ire,
indicates the absolute necessity to jump clear,
making sure no par t of your body or clothing
touches both aircraf t and ground. As the ar ticle
shows, sometimes a risk has to be taken, but
avoiding fur ther trouble is a million times
better than accepting the consequences of illconsidered actions. 0
�Aviation Safety Digest
144 '----------J>.---'
Aviation Safety Digest
.___....___, 144
C P HIRD (ASD 142) certainly brought a swag
of replies! Nearly all were sympathetic and
positive: below is the essence of one that best
encapsulated the general feeling. It came from
Brian Hill, a member of the Canberra Aero
Club, who starts by stating what we all know
too well:
Sir,
It's a worry, alright: that letter about the
difficulties of staying current and safe on a
limited budget.
Unfortunately, the problem is further
compounded by several fundamental laws of
aviation
• if the weather's fine and beaut, every last
aircraft will have been booked hours ago;
• if by chance an aircraft does become
available, you'll inevitably be stuck at work;
• if it's a perfect flying weekend you're sure to
be strapped for cash; and
• on those rare occasions when you can find
both time and money for an hour of circuits,
it's almost certain to be 8/8 overcast and
blowing a gale.
Brian then offers possible ways to get around
these and associated difficulties. They include:
• utilising a bank or credit union loan to finance
in a less painful way the hours necessary to
attain your licence;
• joining in your club's regular competitions
(forced landings, spot landings etc). They
offer good experience and exchange of ideas
for only a modest outlay - say half an hour's
flying;
• trying to get an instructor to be the air judge
in the aforesaid competition, that's the way to
get your errors pointed out! (incidentally, if
you consistently shun such events for fear of
showing yourself up, best have a long hard
look at your reasons for flying in the first place);
• joining in on your club's weekend flyaway
(again you may score an instructor in the
RHS). Two or three of you together can
complete your Unrestricteds in one hit and
get to see a lot of Australia as a bonus;
• insisting on less than a whole hour's hire of
an aircraft if you can only afford less. A mere
30min in the circuit can do wonders for your
confidence; two or three circuits a week will
probably keep you current;
• forming a syndicate to actually buy a basic
aircraft. A once-only buy-in price for say a
Warrior should get you flying for $50-60/hr.
And of course, you can always sell your share
- possibly at a modest profit - if times get
too tough;
• teaming up with one other pilot, paying for
flying week by week about, but flying
together each time, will double your exposure
to all the aspects of aviation that go hand in
hand with merely poling the beast; and
• getting away from the ultra-expensive capital
city aerodromes and taking the family (and
the dog) to a country field for the day. Places
like Camden and Tyabb represent less traffic,
less taxi time, probably friendlier company,
almost certainly better value for your dollar.
Wrapping it up, I'll again quote Brian directly:
Ultimately, however, it has to be recognised
that for most people the privilege and pleasure
of private flying does require some sort of
sacrifice - financial and/or otherwise - and
that if one is serious about staying current then
it costs money, and something has to give.
Sadly, C P Hird, it also depends on how much
your long-suffering, non-flying partner will put
up with. But no doubt you've found that out
already.
(. .. and an answer lo the last paragraph
immediately comes to mind - doesn't it?)
We asked, once again, Steve Tizzard (EofA, GA)
to comment. He is in basic agreement, but
added: 'Do not chase endorsements on, for
example, CSU, retractable, tailwheel or twin
types unless you are going to fly them
regularly: low time pilots can get into all sorts
of difficulty coping with these additional
features if not in constant practice'.
PC RULES, OK?
If you are a PIC, with or without a PC,
commit these BASIC rules to MEMORY,
that they may ECHO in your CENTRAL
PROCESSOR:
e before you LOG ON, always check
your HARDWARE
• throughout your session, ensure that
DIGITAL SYSTEM is not INSERTED
- don't be just a WORD-PROCESSER
• Do not BYTE off more than you can
chew
Never forget that if you have a SYSTEM
CRASH, the SOFTWARE travelling in the
MAINFRAME may become merely MEGABITS and end up on SPREADSHEET
....•••.............& then you are DELETED!
... and Norm Thomson, of Adelaide, reminds us
quite strongly that self-discipline and
application on the ground can result in many
more pleasurable minutes out of each expensive
hour in the air:
Like many other private pilots I, for a variety
of reasons, often have to go for quite long
periods without the pleasure of 'in command'
flight. These days when I do get the chance to
fly I want it to be 'visual' and enjoyable; so
what's the problem?
Well, it may sound strange to the current
professional pilot (commercial or service) but I
believe that the last thing to suffer from
periods of absence is the 'hands-on' control of
the aircraft itself (the old adage of learning to
ride a bike!). I confirmed this on return from
one 20 year absence from flying when I found
both ultralights and ordinary aircraft
immediately responsive - and me to them.
Similarly, visual navigation was no more
difficult than it was in the past. What does
deteriorate rapidly with time is what I call
'cockpit orientation'. That is, the instant ability
to move hands, fingers and eyes to the correct
spot in the cockpit with confident accuracy.
Flying different types only compounds the
difficulty in maintaining proficiency.
With regular flying, routine tasks like turning
switches, moving levers, winding on trim and
cross checking instruments are virtually secondnature; but to the Infrequent Pilot it can
become the predominant, not the subordinate
task. This not only reduces flying pleasure, but
can be darned unsafe as well.
Although I address my remarks to the
'irregular1 private pilot, many crash reports
suggest that they may apply equally to some
professional pilots as well. How often do we
read of an inadvertent raising of undercarriage
(instead of flaps?) while still on the ground, or
incorrect fuel management in commercial flight?
For those of us with more mundane ambitions
it's the hesitancy in 'finding' the electrical fuel
pump switch, or groping - and eventually
looking to the floor or roof - to find the flap
lever or the trim wheel, sometimes tucked away
in what feels like the remotest corner of the
cockpit. Apart from anything else, without
adequate cockpit orientation, confidence is
shaky and crispness and speed reduced. I'm
always afraid that if I move too swiftly I'll
operate the wrong switch. Imagine turning off
the master switch instead of the strobe light or
fuel pump? For glider tug pilots, imagine
grabbing the emergency tow rope release lever
instead of the flap lever!
The point is, that for normal visual flight,
instead of devoting something like 95 per cent
of attention to things outside the cockpit, mixed
in with quick and regular cross checks of the
panel, cockpit disorientation results in using up
eye energy (and time) just locating the
instruments themselves! Its neither comfortable,
safe, nor enjoyable.
So what can be done about it?
Ideally, the old solution of spending time in the
cockpit before start-up still applies. But how
often is such time limited, how often are
passengers impatiently waiting, and in any
case, how often can you get out to the airfield
and quietly carry out such a task? Here is an
alternative that I have found to be an
extremely useful (and completely cost-free!). I
call it 'desk flying' and I first learnt it as an 18
year old, when as a junior cadet I was taught
useful skills by those more experienced. One
gift that I received from the senior classmen
who shared our Nissen hut was to make me, as
a brand new student-pilot, 'fly' the wooden
desk that sat by my bed. That is, pencils,
rulers, ink bottles and the like were very
carefully measured out around me and I had to
instantly and accurately respond to the drills
and procedures directed at me. The result was
that when I actually flew the aircraft, my
hands went unerringly to the correct spot at the
correct time thus leaving me free to devote my
attention to learning how to actually control
and fly the machine.
I was able to apply the same technique later,
especially when working for an organisation
where it was necessary to fly a variety of
aircraft with virtually no dual check-out. In
that case the aircraft manual (especially the
photographs) always gave me a chance for a
pre-flight desk sortie. It's too late to get
airborne with an observer at 2 a.m. and be
unable to find the circuit breakers because your
instrument lights have gone!
Technology today can make refinements easier
for the occasional pilot. Any decent camera can
pick up the cockpit and instrument panel
details. The photographs can be dragged out
and referred to whenever you like, although
pumping down imaginary flap or mumbling
engine-failure drills could prove alarming to
fellow passengers during a domestic airline
flight! Rusty radio- and other procedures can be
similarly polished up. It really depends upon
how interested you are in devoting the
maximum attention to your fitful flying.
There_ is nothing new in all this: it's essentially
pre-flight preparation. When I get the chance to
fly these days I prefer to feel 'at home' in the
cockpit; I believe other pilots do too. I hope
these s_uggestions, despite the smirks they may
evoke m some, prove of practical use to at least
one other Infrequent Pilot. O
�
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Aviation Safety Digest, number 144 (Autumn, 1990)
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144
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1990
-
https://collections.heritageoftheair.org.au/files/original/6f20e55d151cd6a15d9f67d4704d2b36
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ABOUT
• Review your approach plan - circuit entry/ altitude
• Keep to your planned altitude
DOUBT, DON'T
• Keep to the right and break right if in conflict
• Watch the wind - track is not heading
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DOWN THE LANE ...
�Statement by Ron Cooper
Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots), registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
Manager. Publications Centre. P.O. Box 1986
Carlton South, 3053, AUSTRALIA
Telephone (03) 342 2000(4 lines): 008 33 1676
008 33 4191; (03) 347 4407
General Manager, Standards Development
' .. and live to talk about it'
8
1C Dress sense
11
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishmg Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone 008026148. Telex M62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The articles
are intended lo serve as a basis for discussion
and even argument in an effort to identify and
resolve problem areas and potentially
hazardous situations.
Photographic competition results
Downslope winds are dangerous!
1~
These D-M-E'd elusive codes
12
Instrument procedures
1'
Beware the big bang
1
Give military jets a miss
Accident response
2
Canyon flying
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Telephone (062) 68 6319
©Commonwealth of Australia 1988
ISSN 0045-1207
B89/20570 Cat. No. 89 0558 2
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
I took up the position of General Manager of Standards
Development in February 1989 and have since spent much
time refining the organisation to allow us to get on with the
review and development of standards to the benefit of both
industry and the travelling public.
We are currently bringing to a conclusion some projects that
might be termed 'long-standing', the flight crew licensing
review and the classification of flying operations being two
obvious examples. Our intention is to simplify the legislation to
remove administrative action and requirements that do not add
to safety, and so reduce costs and inconvenience. I expect
that, by the end of the year. flight crew licences will no longer
need to be renewed - a current medical slip will be all the
validation necessary.
Following consideration of the first report of the Air Safety
Regulation Review Task Force, a decision has been taken to
adopt a two-tier legislative framework. This will require all
mandatory requirements to be contained within the Civil
Aviation Act (first tier) or the Civil Aviation Regulations (second
tier). Information to assist people in aviation to comply with the
law will be made available as Civil Aviation Advisory
Publications. This system will be introduced progressively, in
line with the review of particular standards. The two-tier format
will replace existing CAOs relating to a standard, and the aim
is to have the more simple system completely in place within
four years.
Review and development of safety standards is a major step
towards providing benefits to the industry and the travelling
public alike: I am both enthusiastic and optimistic about the
future of aviation in this country.
Action is well advanced to revise the rules governing the use
of ultra-light aircraft; CAO 95.55 and its related orders are
expected to be in effect by the time you are reading this edition .
Editorial
Ground to air
Editor:
Editorial Assistant:
Roger Marchant
Lyn Coutts
Graphic Design:
Diagrams:
Soussanith Nokham
Kathy Foldszin
Cartoon:
Gary Clarke
Photographs:
P5 & 7
P10
P17
P18
P2 1
W
E HAVE SEEN over the past few months, and probably
will see in the near future, turbulence (pun intended) in
the aviation industry; it may be some time before
stability returns.
Standing aside from the infighting are the eternal verities of
aviation: training, responsibility, and gravity. Knowledge gained
from diligent application of the first two will go a long way
towards conquering the third. Knowledge is what the Digest
tries to offer every pilot. The BASI Journal most effectively sets
out the accidents, and you will profit from perusal of that
publication; we attempt to keep you out of their (bulging) fi les,
and incidentally, out of the hands of Al Bridges, my
predecessor and Editor of ASD 's 141 and 142, who has moved
to a senior position within the Bureau. We extend our good
wishes for his new job.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the material without altering
the author's intended meaning.
VIATION IN AUSTRALIA depends upon the skill and care
of those involved in the industry , operating within a
rational and appropriate framework of safety standards.
The better the framework, the easier and more efficient it will
be for the industry to provide safe aviation for more people.
The development of a better framework of aviation safety
standards is a challenging and rewarding task that has been
allocated to Standards Development.
U ~~~~~~~~~~~~~~~~
1
2
() A
Bureau of Air Safety
Investigation
from 'Born to Fly' by
Nancy Bird Walton
NT Dept of Mines and
Energy
Department of Defence
Honeywell Industries
be apprehensive about taking advantage of what is a very
good system. As I say somewhere else, 'the Air Trafficker is
your friend!'
Finally, a few lines to introduce myself: 20 years navigator
RAF, five with the RAAF (radar controller, Tullamarine), eight
with Aviation, DoTC and CAA, mostly in Flight Standards. I
have been writing for Australian and overseas flight safety
publications for many years and maintain a passion for general
aviation. My aim, therefore, is relevant articles, interesting
letters, controversy where productive, but with accuracy as top
priority. After all , never was I more than half a mile off track.
Mr Cooper's statement indicates that, whereas the law is the
law, a somewhat simpler presentation should enhance
comprehension and thus compliance. The 'rules' are designed
to offer flight safety to those who know and remain within
them. It is always as well to remember that just flying an
aircraft requires lots of ability and attention - in this business
doing the unexpected merely loads the odds against you.
Following the pieces on mid-airs in ASD 142, we now present
an accident from which the pilots walked away. Applied
knowledge in this case saved them both: it is worth reading the principles involved apply to any aircraft, and the lessons
are there for the taking.
Also, this edition welcomes 'Ground to Air', the beginning of
what I hope wil l be a regular feature giving Air Traffic Services
a voice in this forum. The blow-by-blow record of a run down
the lane to Moorabbin should be read in conjunction with the
GAAP poster from ASD 141 and this edition's back cover.
There is an awful lot of controlled airspace around our capital
cities - not to hinder pilots, but to help them. No-one should
1
Covers
Front: The cover picture by Brian Westin
titled 'Avoiding Action-Whose
Environment' is the winner of Category
Two of the NIKON/ASD photographic
competition.
Back: Poster design and production by
Norm Wintrip
�Aviation Safety Digest
143
' ... and live to
talk about it!'
Scenario
Both pilots were at Horsham to compete in the
annual 'Horsham Week' gliding competitions. On
the day of this accident no task had been set
but both pilots had taken the opportunity to
make pleasu re/familiarisation flights of the
area.
At the time of the accident the two aircraft
were at approximately 5000 feet above sea
level. VH-HDY was flying towards Horsham on
a constant heading of approximately 330
degrees. The aircraft was in a descent and the
pilot estimated he was about 1000 feet below
the cloud base. Cloud cover was reported as six
eights of cumulus type cloud.
VH-KYO was flying in the opposite direction to
VH-HDY, also on a constant heading at the
same altitude. The pilot of VH-HDY reported
that he had just completed a scan of his instruments when he looked up to see the other glider
head on. He was unable to prevent a collision.
The pilot of KYO reported that he had also
looked up from concentration on another task,
to sight the other aircraft head on at the very
last moment. He had no time to take any avoiding action.
The right wing of HDY hit the nose/cockpit
area of KYO, smashing the canopy, dislodging
the instrument panel and damaging the nose.
HDY lost part of its right wing, became uncontrollable and the pilot took to his parachute.
The pilot of KYO received injuries to his right
foot and face in the collision but was able to
maintain control of the aircraft and fly it back
to Horsham where he made a safe landing in a
paddock beside the aerodrome.
At the time of the accident both aircraft were
operating in an environment where the pilots
were responsible for maintaining separation
from other aircraft on the basis of see and be
seen. In this accident both aircraft were
approaching head on, both were gliders with
thin wings and narrow fuselages, both were
essentially white in colour when viewed from
head on and both were against a background of
whitish coloured cloud. Such circumstances
would have made it very difficult for either
pilot to sight the other's aircraft.
This is a difficult accident upon which to make
any meaningful safety recommendations. What
it r eally boils down to is that the accident
occurred because the pilots did not see ea ch
other's aircraft. They w ere operating in a see
and be seen environment yet failed to see and
be seen. Both admitted that they had not been
Aviation Safety Digest
143
looking out immediately beforehan d but both
had been on a constant heading for a consi derable period prior to the collision. Both had
been following the same 'cloud street' but in
different directions.
The accident was discussed in depth with the
Gliding Federation and a point it made was
that when there are cloud streets existing a
pilot should always keep it in mind that someone else will no doubt be following the same
street and not necessarily on the opposite side
of the road. It is a ti me for extra vigilance, and
in this case that was exactly the situation.
An idea that comes to mind for accident prevention when considering the above is 'at what
distance could a pilot r easonably be expected
to see another glider in a head on situation,
such as was the case in this accident?' Gliders
head-on do not present much to the eye.. A
glider that is basically white against a whi tish
cloud background obviously makes acquisiti on
very difficult.
It is recommended that some research be d on e
on this area with a view to publishing some
meaningful information to the gliding fraternity. Whether the research be done within BAS!
or outside can best be decided by BAS! Central
Office. Allied to this subject are closing speeds
and reaction times. In this case the closing
speed was appr oximately 170 knots.
Both Duncan Ferguson and Bob Irvine are v er y
experienced glider pilots, and have written for
us two detailed an d efficient accounts of the
accident. Having accepted the fact that the
mid-air perhaps was preventable, it is a
pleasure to publish 'success' stories such as
these, wherein are cover ed practically all
aspects of post-collisi on survival...
I h ad seen h im only just before the impact. He
was coming straight at me - his fuselage
slightly to the right of mine, wings and pitch
level. I had no time t o take avoiding action .
Not surprisingly, the impact was violent but
brief. My first reaction was disbelief. The canopy had gone, the u pper h alf of the nose of my
glider had been dest royed an d t he instrument
panel had been bent t owards me and across to
my left. I was aware that I was injured but I
had not lost consciousness an d felt alert.
With considerable damage to t h e glider and t he
airflow blasting my face my first decision was
to jump and use the parachu te. I quickly
released my harness and located the rip cord
handle with my right h and - careful not to
pull it at this stage. Since I h ad plent y of height
- about 5500 ft - I took a couple of seconds
to tighten the straps on my parachute.
I then realised that t he glider was still flying
wings level but in a slight dive. Although I
didn' t really believe it would be controllable, I
thought it worth trying; I had plenty of height
to jump if it became necessary.
I took hold of the stick a nd s uccessfully r aised
the nose , happy to feel the r educing airflow on
my face. The aircraft felt n ormal. I quickly
decided that it was worth fur t h er investigation.
Again I let go of the stick in order to re-latch
my harness I latched t he waist straps on ly. I
then s ystematically tested all the primar y controls - eleva tor aileron and rudder. All
functioned normally, s o I flew sever al gentle 'S'
turns without incident . I h a d no instruments
but felt this of little concern. I looked at each
wing and they looked fine . Since t here was no
canopy and I only h ad waist straps on I was
able to sit upright and turn my h ead to exa mine
the tail. It looked normal except that t he Brunswick tube on t he fin w as bent considerably .
This was the only damage I could see outside
the cockpit area.
0
Duncan Ferguson
Saturday 6th February was to be the first day
of competition for Horsham Week 1988. Since
there had been a lot of r ain overnight, the competition organisers decided to cancel the day
rather than risk outlandings in boggy paddocks.
However, local flying would be permitted in the
afternoon.
I decided to take the opportunity to further
familiarise myself with VH-KYO, the LS4 I had
hired from Euroa Soaring Centre. I launched to
2000 ft at around 4.45pm local time. The surface wind was about 15 knots SW and soaring
conditions looked good with 4/ 8 Cumulus at
about 6500 ft .
I quickly climbed to around 6000 ft and about
20 'minutes after launch decided to follow one
of the cloud streets that led south towards t he
Grampia ns. The street was working well and I
was a ble to ma intain height without turning
between 5000 and 6000 ft as I headed s out h.
I reached a point about 10 km south of the
aerodrome, cruising at about 90 knots (IAS),
when I collided head-on with t he ASW-20B.
CJ
0
At this stage I decided that a landing might be
possible. The on ly other control I needed for a
sa fe landing was the air bra kes. Not much time
had passed so I consider ed t hat I still had well
over 4000 ft - still plenty of height tq jump
should the airbrakes cause some failure in the
wing. I gently cranked the brakes open and
extended t hem to about two-thirds of their
limit. Everything felt norma l so I closed them
again .
I was then satisfied that t he glider was probably capable of being landed; I recognised t h at
it was likely that there would be other damage
t o the airframe but t he glider felt fine. The only
oth er question wa s whether I was well enough
to carry off a safe landing. I didn 't feel too bad.
I knew that t here wa s somet hing w rong with
my r ight leg and foot but I could work t he rudder. There was a lot of blood a round. My left
arm and face were bleeding a lot. My left eye
had obviously received a thump because it was
alr eady swollen to the point w here I couldn't
open it. I could see clearly out of my right eye,
t aking into account the irr itation of the airflow
in my face. I felt around my face and hea d to
see if t her e were any more serious injur ies but
found none . I felt aler t and reflected on the fact
t hat I was thinking clearly . I committed myself
t o a landing.
I decided t h at the safest way to descend was at
a low airsp eed and without airbrake. Although
I w ould be airborne longer, this would put minimum st ress on the airframe. Since I would be
a chieving a r easonable glide angle in this configuration I decided that I may as well h ead
towar ds t he aerodrome. I wasn 't overly concerned abou t reaching t h e aerodrome but I
though t it was worth a try.
The single fact t hat most concerned me was my
vision. My good eye (the right one) was being
blocked by blood from cuts on my face. A
couple of times this complet ely obscured my
vision. I used my left hand and part of my shirt
t o clean out the eye regularly during the
descent.
�Aviation Safety Digest
143
Aviation Safety Digest
143-I tracked well to the east of the city of
Horsham and then towards the aerodrome. I
could see by judging the angle to the aerodrome
that I was going to make it easily.
I decided that the landing should be conducted
with the main wheel retracted. This would
minimise the ground run - thereby eliminating
the risk of damage due to loss of control on the
ground. I was also concerned t~at lowering the
wheel might cause further stram on t he structure with the attendant risk of structural
failure.
I decided to land directly into wind in a paddock immediately adjacent to the duty strip and
the Pie Cart. I felt that a landing on the duty
strip would carry an unnecessary risk of damaging one of the many gliders tied down alongside should I loose control near t he ground. I
had had a good look at t he paddock before
take-off. Ironically, a training glider pilot had
asked me whether this particular paddock
would be a suitable choice for an outlanding. I~
was. I felt that a landing within sight of the Pie
Cart was a priority since I wanted to attract
the attention of the people in the area. I knew I
would need medical attention and I could also
alert them to the fact that there was probably
another pilot in trouble.
I flew to a point directly downwind of the Pie
Cart area, arriving at a good height for a long
straight-in approach to the paddock. I had a .
very gentle left t urn onto long final. Everything
worked well. I left the wheel up and used half
airbrake during the first part of the approach.
The touchdown was gentle but the ground run
was very short. People from the Pie Cart soon
came to my assistance and called an ambulance.
Bob Irvine
I am a very keen competition gli~er pilo~, and
after placing third in the Australian N~t10nal_
Championships, I decided to share a ghder with
the other members of my club in Horsham
Week which is one of the biggest noncham~ionship glidir:ig competitions ~n the calendar and competitors vary from beginners to
ch~mpions. I enjoy both the low-key flying-for
-fun atmosphere and the ideal gliding countryside around central Victoria.
On the first day no task was set, due soaking
rain and high wind. By afternoon, however,
conditions had improved sufficiently to allow
our club's UK visitor, Cynthea, to launch the
ASW 20 sailplane for an area famil. She flew
for an hour and a half below 7 /8 Cu, finding
strong thermals in the moist, unstable air. I
then launched at about 4pm and found conditions very good: thermals of 600/800 fpm to
the 6000 ft. cloudbase.
I flew south to the Grainpians, a mountain
range of considerable ruggedness and beauty,
some 50 km south of Horsham. Because of the
close spacing of the cumulus clouds, I was able
to stay high, frequently near the_ c~oudbase and
never below 4500 ft. This made it ideal to
explore the otherwise forbidding region without
th e risk of an outlanding. As I approached the
mountain peaks surrounding Wartook Reservoir, I deliberately climbed close to the
cloudbase (6500 ft. over the peaks) to keep a
healthy safety factor for a glide, if necessary,
to the nearest paddocks, 25 km away. In the
event, this was not needed; the lift so regular
that I could maintain altitude near the bases,
s imply by flying from _c~oud to ~loud 3:n? sl owing down in the best nsmg air ( dolphmmg ).
Thus I made my way back to Mt Stapleton, 33
km from Horsham.
l
•
1
Since I was above 5500 ft. at this point, and the
countryside steadily fell away to flat farming
land, I was in easy gliding range of Horsham
Airfield even allowing for the strong westerly
drift. I decided to RTB direct, heading considerably upwind of the now-visible airfield in order
to counter the drift, frequently looking at my
destination as confirmation that the glide angle
was satisfactory.
It is useful practice for competition gliding to
carry out realistic glides to the airfie~d f:om
various directions, learning to recognise important landmarks and the general look of the
place, so that in actual competition_ no time is
wasted on the 'final' glide. If the pilot leaves
his last climb with in sufficient height, and
glides down too low before recognising_the need
for more height, he may be unable to fm? more
lift and thus be committed to an outlandmg, or,
in competition, be forced to use ·~eak' l~ft and
t hus waste time gaining the reqmred heigh~. On
the other hand if he leaves with excess height,
and fails to re~ognise this, he will arrive at his
goal without having taken advantage of the
energy surplus. The correct technique is to sta~t
with an excess of height and fly at an appropriately higher airspeed, as the excess height is
recognised with greater and greater _acc~racy,
reducing the excess only when the circmt area
is reached.
However, I was well over the required height,
and making no attempt to fly the correct speed
as I approached Horsham town. My memory
tells me that I was at about 5000 ft and 70-80
kt. Then, as I lifted my eyes after an instrument scan I saw another glider, head-on and
very close: directly in front of me. I judged it to
be just above so pushed the stick hard forward;
in what seemed like 2-3 seconds it passed over
the top of my cockpit.
I almost had time to think 'Missed!' before I
heard the bang. My aircraft continued to pitch
down into a steep dive - attempts to pull out
were quite ineffective and I was experiencing
negative 'G'. I decided there and then that I had
no control in pitch and would have to bail out.
0
G
I consciously located and identified the red
canopy-jettison handles on each side of the
cockpit. A moment of indecision - 'Should I
go?', but the aircraft was now past t he vertical
and I was hanging in the straps, so I had no
choice . I jet tisoned the canopy, which immediately tore out of my hands in an explosion of
plexiglass and a roar of air. My glasses and
maps vanished with the debris sucked out by
the wind.
I remember staying quite calm, and thinking
t hrough my actions. Since I was hanging in the
straps, I would fall out as soon as I released my
seatbelt, I decided to locate the parachute
ripcord before I departed. I grasped the handle
with my right hand (a little awkwardly, as it
was j ammed between my left side and the
seatpan), then pulled the seatbelt release. I
immediately fell cleanly from the aircraft. I
pulled the ripcor d until it was completely out of
the pack and a few seconds later saw the parachute sn aking ou t behind and above me .
Because I was falling head-down, the view I
had of the opening was between my legs - it
seemed st range ... I had expected a large jolt as I
came to t he end of my tether, but it was
surpris ingly gentle as first I was snatched
upright by the shoulder straps then arrested by
the leg h arness. Ever ything went extremely quiet.
Several seconds later, I saw my glider above
me, inverted. It passed below and continued
down in a flat spin It seemed to take ages to
descend, but t hen impacted in a ploughed paddock below. The sound of the crash snapped me
out of my calm reaction phase; I could now feel
the adrenaline in my system and for the first
time felt fear. I craned my neck, but couldn't
see another glider, or even a chute.
The next few minutes were a condensed lesson
in parachute flying. I practised turning (by
pulling the bundles of lines behind each
shoulder) - yes, I could turn, but turning created large pendulum swings as well. So I practised not t urning. The wind was pretty strong
(20 kt), so I headed into it. Even so, the landscape under me moved backwards and it was
hard to see w here I was going Eventually I
realised t h at t h e ground was rapidly approaching, and I was safely over one fence and clear
into t he next paddock. The landing (bent knees)
and backwards roll were not elegant, but I was
up and ready to reef in one side of the canopy
as it fell, before the wind could reinflate it. It
was a bit of a struggle, but I eventually managed to collapse my friend the parachute. Then
I could relax.
I walked to a road, followed it to the highway
and called Horsham from a farmhouse (it
wasn't easy - the lines were engaged: I wonder why?). They told me the other glider had
'crashed' on the airfield, and the pilot was injured.
When help arrived, we went back and examined
the wreckage. To my surprise, the tailplane
h adn't been struck, but the starboard wingtip ,
including the aileron, had lost 2.5 metres.
It seems that after the collision the aircraft
entered an inverted spin because it was at a
negative angle of attack (as I attempted to
dive) when it received a large yawing moment
(impact) and rolling moment (asymmetry of the
wings).
So what have I learned? Well, the importance of
a good lookout is obvious. I think my attention
in general was outside the cockpit and in the
direction it needed to be (ie focused on the distant ground, out near the horizon ahead). But a
glider [any aircraft? - ed.} approaching
head-on is hard to acquire.
Bailing-out? Glider pilots always wear parachutes in competition; most strap them on at all
ot her t imes, except perhaps for circuit training.
The majority of our sailplanes are designed
with bail-out in mind. The ASW, for example,
has a plexiglass canopy 1.8 m long and, when
jettisoned, the complete canopy, frame and all,
is blown away. The instrument panel then
springs upward, allowing the pilot an
unobstructed escape-route. It was also obviously well worth-while that I had familiarised
myself with the emergency exit procedures and
parachute operation. Having this knowledge
kept me calm and helped me work through the
procedures without panic.
This is not to say I advocate parachute training
for all! The modern safety chute operates
reliably for even unskilled operators, in the
most d ifficult of circumstances.
I have always said that I would do my first
jump when the wings come off. They did, and I
did. A nd it saved my life D
�Aviation Safety Digest
143
The Digest competition was a great success, attracting over 200 entries, most of an exceptional
standard. My thanks to all those people who participated and made my job and that of the two
other judges so difficult! The winners are:
Category One: The open category for the best overall photograph was won by James Dobbin for
his Tiger Moth Over Cairns. This picture is featured below; James wins a Nikon f-401 Auto-Focus
SLR camera with a 50 mm FL.8AF lens.
Category Two: The category for a photo on a safety theme was theme Brian Westlin, for
Avoiding Action - Whose Environment? (cover picture)
Category Three: The best black and white
entitled Thrush (on facing page).
p~oto
was that by David Foote with his picture
Both Category Two and Three winners have been awarded Nikon TW2 Dual Lens AF Compact
cameras, all prizes being kindly donated by MAXWELL OPTICAL INDUSTRIES.
In addition it was decided to award a number of Highly Commended citations.
The winning entries will be featured in future Digests, and the awards go ( in no
particular order of excellence) to:
Category One:
Kevin Waid Augusta
Kim Wirth PA23 Off the Coast of Cape York
Dennis Starson Finals
David Staley Photo of the B200
Category Two:
Andrea Hirschon Double Troub le
Andrea Hirschon Off With His Head!
Raymond Wilson Further Left, Mate!
()
Category Three:
David Foote for a second entry, also titled Thrush.
�Aviation Safety Digest
143
Down slope
winds are
dangerous!
Dress sense
')
l .
Bureau of Meteorology
ECHANICAL turbulence and downslope
waves are well-known hazardous conditions that form in the vicinity of mountains under certain meteorological conditions. A
not-quite-so-familiar condit ion involves
downslope winds which, under favourable conditions, create wind shears and turbulence in
the downwind (or lee) side of the mountain.
These can be particularly dangerous t o aircraft
close to the surface.
To see how these effects occur it is necessary to
develop a picture of the airflow under particular circumstances. In the example, we consider
an easterly low-level flow in the region just to
the east of Adelaide (see diagram).
M
HAT WAS THAT? This is often the reaction of many of us to the figure dressed
in old leathers with a battered helmet
stuck on his head - the bikie.
But experienced motorcyclists know the
dangers, particularly the injuries they might
sustain coming off the bike, even at a low
speed. Good riders dress for the occasion - not
because they plan to fall off every time they
set out: they merely take sensible precautions.
On the roads of today, they aim for survival.
Exactly the same dress sense is important though often ignored - in other activities ...
cover up on the beach against the sun, wear all
sorts of things against a fast bowler, don't wear
WWII 'paratrooper' boots when parachuting
(they tend to transfer the load off the ankle on
to the lower leg - could be nasty in a
crosswind). In motor racing, protective gear is
mandatory.
What about flying? Why is it that the Defence
Forces purchase expensive Nomex flying suits
- coveralls - and equally efficient gloves,
boots, socks and helmets for their aircrew? It's
significant that most of this clothing is antiheat, anti-fire.
Many people have survived the crash but died
from toxic smoke inhalation or, overcome by
the heat, have perished in the ensuing flames.
Dress sense and rapid evacuation provide the
best protection against heat, fire and smoke. A;.
smoke hood may be of use but may, on the
other hand, cost the potential survivor valuable
seconds of escape time trying to put it on properly and then removing the smoke that is
already inside.
In aviation, particularly for aircrew, dress
sense means covering as much skin as possible.
Wear well-fitting clothes, not too tight, _but certainly not loose and flowing. The more layers
you wear, the more protection from heat and
flames. Choose light colours and a tight knit,
rather than dark colours and a fuzzy material.
W
The best protection in everyday clothing is
closely-woven, light-coloured wool.
Although synthetics generally are not good
(they melt into your skin), some are expressly
designed to offer fire protection. They are
expensive and not found in everyday clothing,
but may well be one of your best investments if
you are a regular flyer. To check the character- \
istics of a material, take a. few strands and
__,J
burn them. If they melt - don't wear the garment they came from. Try to find something
that merely chars when put to the flame.
Shoes are very important items of your clothing. Again, they must be well-fitting and should
be made of leather. Shoes with open toes, high
heels, sandals and thongs ought not be worn in
aircraft. Because of the problems during the
emergency evacuation of a badly broken-up aircraft, flat shoes are obviously to be preferred
- high heels can so easily get jammed in
wreckage; they certainly will make their wearer
less sure-footed at a time when agility could
equate to safety.
Dress sense is applicable equally to a Cessna
150 and a 'Boeing 747. fndeed, it is important in
all forms of transport. Just as the motor-cyclist,
none of us expects to becomeArwolved in an
aceident, otherwise we'd stay indoors. But once
committed tO' a journey, the statistics act
against us. Therefo-re, to be prepared;rni_ght
mean the difference between a long li-fe and a
tragically short one, or even worse, years
where each day is filled with the agony of third
degree burn scars: the Guinea-Pig Club of WWII
could tell us - but they had the odds really
stacked against them 0
DRESS SENSE
CLOSE-KNIT WOOL COVERING
AS MUCH AS POSSIBLE_
ENCLOSED, LOW-HEEL LEATHER
SHOES
GLOVES D
0
gentle slope to windward and a steep ,slope
leeward).
The downslope winds and associated effects
described above occur predominantly in the
warmer months of the year, particular ly during
the period from late evening to mid-morning.
Pilots operating to the immediate west of the
Darling Scarp nea r Perth, or of the Mt Lofty
Ranges in SA, should expect turbulence near
the surface in an easterly airflow, especially
during the night and in the early morning.
These hazards may exist on t he lee side of any
large hill/ mountain, if conditions are right.
In the absence of confirming evidence from
other aircraft or specific wind shear
information, Wind-socks may provide valuable
visual clues to the presence of wind shears and
rotors. If an aircraft on its approach experiences considerable drift - and one or more of
the windsocks is limp, or if the socks are pointing in different directions, w ind shear and/ or
rotors must always be suspected. Be aware,
however, that rotors may not be all that large
in area, although quite vicious in effect. One to
two kilometres across is usual, which means
2
(
1
(km)
•
~
A
/
(
DISTANCE
(km)
ROTOR FORMATION NEAR ADELAIDE AIRPORT. THE CLOCKWISE ROTOR IS PARTICULARLY STRONG.
0
As the airstream crosses t he escarpment it
flows quickly down the lee side, and a marked
wind shear occurs near the discontinuity
between the r apidly descending air and the
relatively slow-moving or undisturbed air
further away from the escarpment. Towards
the base of the escarpment t urbulent eddies or
rotors may form as a result of this wind shear,
creating a very dangerous situation for aircraft
on approach or take-off. The airflow under
these conditions is analogous to the frothy, turbulent water visible at t he base of the spillway
of an overflowing dam. The t opographicallyinduced wind shear and turbulence is accentuated where there is a ramp-shaped range.(ie a
that the visual clues may not be available until
you are almost upon the beasts.
Bureau of Meteorology staff in Adelaide and
Perth are working towards the provision of
more specific advice concerning wind shear and
turbulence. One result of t heir studies is the
confirmation that the degree of turbulence is
related not only to windspeed, but also to the
difference in temperatures between the points
A and B, as indicated on the diagram - the
greater the variation, the more severe the
turbulence D
�Aviation Safety Digest
143
Those D-M-E'd
elusive codes!
HIS LITTLE article is directed, I'm sure, at
only a handful of Australian pilots. These
few, though, can make life very difficult.
Australia, New Zealand and PNG have a DME
system, known here as 'Domestic ('Australian')
DME', utilising the 200MHz frequency band. All
other DMEs around the world operate in the
lOOOMHz region, and are known here as 'International DME'.
With more and more 'international' DMEs being
installed around the country, it becomes
increasingly important for the pilot to make
sure that ATC know what type of equipment is
carried. Aircraft with only international DMEs,
for example, cannot interrogate the 'Domestic'
version, and vice versa.
Therefore, ATC can only provide the 'quicker'
service associated with the use of DME (separation by distance) if flight-plan information is
correct.
And here lies the s nag. Over the years, there
has been not only a change in flight-plan format, but also in the identification of DME
information upon that plan.
As a signatory to the Chicago Convention, Australia has accepted the great majority of the
flight standards developed by the International
Civil Aviation Organisation. One of these, very
small, but totally logical to the r est of the
world, is the adoption of 'D' as the flight plan
designator for DME ('international' DME, of
course), just as 'O' is used for VOR, 'F' for ADF
and ' L' for ILS. After the ICAO designators
were used, 'X' was one of the few letters still
available, so this was chosen as the code for
domestic DME on the domestic flight plan form.
Therefore, in the navaids box in the Aus tralian
domestic flight plan, there appe ars 'D' and ' X' ...
T
'0' MEANS 'INTERNATIONAL' DME
'X' MEANS 'DOMESTIC' DME
Therefore, pleeeeeease, get it right! Take pity
on the poor old Domestic-DME-equipped Air
Trafficker who has set up a nice tight sequence,
on the assumption all the arriving aircraft can
read out their DME distance, only to find that
s ome !#!$%?@! put 'X' on his flightplan, thinking it meant 'internationa l', and can't in fact
interrogate the beacon . Believ e me, a lastminute revers ion to more one rous st andards for
separation not only wastes your precious time ,
but grows ulcers on the controller 's ulcers.
* * * *** * ***X for domeXtic !**********
If you are not el igible for a free issue, or if you would like add itional copies of the Digest:-
Instrument
procedures
METICULOUS
'scrupulous abou t minute detai ls; very careful,
accurate' ·(fr om Latin m etus = f ear)
Four
Instrument procedures are carried out by the
thousand each day: the majority of pi lots flying
large jets make every approach on the clocks,
VMC or no, and lesser mortals rely on the NDB,
!LS etc when i t's a bit murky. Adde<i to this
is the daily training, traini ng, trai ning in
instrument p r ocedures, whether it be 'cheap ly '
(in the simulator) or und er the eagle eye of an
examiner/ ins tru ctor in the real air.
$A 14.00
AVIATION SAFETY DIGEST reports incidents, recounts
stories, relays technical information, represents the pilot
and others involved in aviation, and, to the extent that it
falls short of being a legal document, reflects the viewpoint of the CAA.
We have noted previously that regulation alone may well
have been exhausted as a means of reducing accidents.
This is not to say the CAA is on autopilot - there are
moves afoot to make CARs, CAOs and subsidiary legislation more user-friendly (or at least, somewhat simpler).
I wonder, though, j ust how much we u n d erstan d the need to fly accurately when we let
d own i n weather ? (other than w hen we're being
observed by the aforesaid examiner, that is).
Although an aviator will always benefit from reading about
another's brush with disaster, we are all fortified in the diligence of our personal pursuit of safety by the knowledge
that there are a lot of fellow flyers who think twice - nay
three ti mes even - before committing themselves (and
their passengers - never forget the pax) to operations in
John Edwards here leads us gently throu gh
some of the p roblems facing the p rocedure
designer and his inter!ace with th e pilot. The
piece d eserves careful reading - althou gh the
concepts are simple, the complications f ollowing therefrom show tha t 'meticulous' in a ll i ts
shades of meaning is the correct adjective to
descri be the su rveyor's work.
(includingsurtacepostageJ
marginal conditions. Self-discipline, mechanical reliability
and the correct application of hard-gained expertise are
but the three leading links in the chain of circumstances
that define a truly successful flight.
The wide range of submissions that cross the editor's
desk are testimony that 'marginal conditions ' cover practically everything. There are a million articles out there in
the real world, and a zillion incidents (99% of which you
wouldn't dream of putting your name to - that's OK,
we 'll respect your desire for anonymity). So why not share
your hard-earned lessons? As I said, your story is unique!
To be part of this accumulated wisdom , those with an
interest in flying, be it as a professional or paid-for-byyourself, will do themselves a favour by reading the Digest
on a regular basis; if you do not obtain a free copy, the
subscription form is, as they say, overleaf.
------------------------------------------~---
Producing an instrument procedure represents
one of the more dem anding aspects of the airw ays surveyor's craft. In Austr alia, the requirement is identified and subsequent draft p lans
are drawn up by surveyors in the Field Off ices.
The fi nal design, ch ecking, approval, drafting
and , if all be well, publi cation is a Head Office
responsibility.
It is an extremely serious aff air, where the
meticulous (that w ord again) stan dar ds intern ationa lly agreed are rigorously applied. The
procedure designer wants to assur e a ll pilots
flying instrument procedures that they will not
hi t the groun d, or any known obstructi on. However, an d this is where we _must read carefully,
to stay alive the pilot must not only be aware of
the constraints implicit in the d esign of the
ap proach, bu t stay alw a ys within those limits.
iSSU8S
Feeling a little query?
I
0
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
G.P.O. Box 367
CA NBERRA A.C.T. 2601
Australia
I
I
I
I
I
~
A viation Safety Digest 143 / i
�Dear Sir,
I'm concerned about people who enter occupied
hangars whilst taxying their aircraft - a practice I witnessed recently.
The diagram shows the relevant layout:
angar
angar
c
CHEROKEE
L
-+-
u
B
H
0
,,-
u
s
I
E
I
,,
/
I
I
I
Taxiway
--
,,~
/
\
~
emf
---~-----
This letter arrived from a correspondent who
did not want to be identified: that's all right the message is of sufficient importance to act as
a reminder to all pilots. Laziness, or misplaced
over-familiarity and over-confidence has led
the pilot in question to display appalling
airmanship (yes, airmanship applies on the
ground as well: goodness knows how he flies).
And yes, it was illegal: he blatantly transgressed CAO 20.9 subsection 5. There are so
many complicated traps in the aviation game
- why on earth get caught by a simple one?
I was sitting in the Long Ranger, ready for a
demonstration flight. The Cessna 210 attached
to the Aero Club returned, taxied around the
back of the 172, entered the hangar then turned
through some 120 degrees. Normally, the 210 is
backed into the corner of the hangar, with the
172 blocking the way out.
Obviously, the 172 had been pulled out of the
way so the 210 could depart. This left not much
room on the grassed/tarmac area to turn the
210 around when it returned.
Of course, shifting the planes manually would
have meant a hassle with the steering handle,
plus muscle work: it's always convenient to
stop as close to the parking spot as possible,
and 99 times out of a 100 a pilot will get away
with cutting the corner on safety to do just that.
But I tend to think of what the results could be
if that 1:100 chance came up, and in this case
there was a real risk of collision with the
Cherokee in a hangar with a built-in clubhouse
and a 172 parked just outside. And all this
within a couple of metres of another hangar
containing a stationary he licopter with another,
rotor turning, outside. To me, it was poor
airmanship, indicating a lack of thought or
awareness of possible consequences of the
action.
I was taught never to trust aeroplane brakes to
be 100% effective at all times - an instructor
whose opinions and explanations I respect
drummed that into me the first time I rolled
nose-first up to a fuel bowser.
iv / Aviation Safety Digest 143
Such a scenario sounds horrific to the uninitiated, principally due to the lack of opportunity to participate in the decision making of
the critical last minutes prior to touchdown.
Applying such judgement to the conduct of a
well-planned outlanding is a highly rewarding
experience.
Gliding training has greatly reduced my concerns regarding the outcome of an engine failure or such while flying powered aircraft.
Laurie Hoffman
Even those who fly privately have to be professional in their approach to those areas
because, I believe, they are the foundations of
aviation safety. When someone does something
stupid the public doesn't distinguish between
professional and private pilots. Flying gets the
blame, thus reinforcing the attitude that what
is really one of the safest of activities is the
most dangerous.
A study of flying organisations' maintenance
accounts might well make trainees appreciate
the potential cost and effect of careless
mistakes.
Dear Sir,
In ASD 139 Michael Badge expresses his concerns that flying training rarely provides actual
forced landing practice. Having made literally
hundreds of forced landings, I agree
wholeheartedly with Michael that what happens in the last few hundred feet 'determines
whether your passengers survive or not'.
The relevant articles promised for ASD will be
most useful; however, the point is that firsthand experience, so crucial in the training of a
pilot to cope with such an emergency situation,
is generally unavailable.
Training in carrying out forced landings is actually readily available through organisations
which have been conducting such exercises for
decades - gliding clubs. Most power pilots
would be aware that every· glider landing is a
forced landing , but few would realise that many
of these landings are actually 'outlandings'.
Glider pilots who regularly fly cross-country
tasks do so in the knowledge that on at least
some occasions their flights will end in an
outlanding. Training permits them to methodically and as a matter of routine select a suitable landing area during the final minutes in
the air.
]
Agreed. Gliding does provide practice at landing without an engine - every time! (and a lot
of other skill-sharpening practices for pilots in
general). Gliders also have flatter glide angles
than most light aircraft, and better control of
the approach glide angle. Even for an experienced glider pilot an engine-off landing in an
aeroplane is highly stressful.
As to Michael Badge's letter, unless pilots have
access to an ALA (with the owner's permission,
of course), the actual touchdown during a practice f arced landing carries greatly increased
risks, particularly if the surface hasn't been
inspected. Rocks, stumps and holes usually
aren't visible from circuit height. The surface
may be rough, boggy, covered in tall vegetation
and contain unseen fences. It is absolutely
essential, before landing off a practice forced
landing approach, to know that the surface is
safe for landing (and a subsequent take-off!),
and to have the landowner's permission. Not
even glider pilots land without doing this, if
the outlanding is for practice rather than
forced.
Any touchdown in a real paddock {whether
practice or after engine failure) must be as
slow as possible to reduce ground-roll, wings
level, and into wind. In a retractable the
wheels are provided for a landing on, so they
should be used in a real forced landing if at all
possible, unless the approved pilots handling
notes recommend otherwise.
Mike Cleaver, Inspector (Sport A viation)
Support for this sort of training also came from
Mark Townsend, of Bankstown, who is of the
ultralight fraternity. Here is a paraphrase of
his most pertinent point: '... and as ultralights
are currently required to operate no higher
than 500 ft, much time is spent considering
emergency procedures that commence below
that altitude and do not terminate until the
aircraft is well into ground effect ... If you want
to know what it's like to 'go all the way', afew
hours spent at an ultralight training school
will probably do more for your forced landing
education than a week in the training area. '
Dear Sir,
I am writing to you to express my views with
reference to the back cover poster which
featured on ASD 140 by Kathy Walter.
As a LAME and Flight Engineer one can but
wonder who holds this belief that the LAME or
indeed mechanics and engineers in general are
in anyway viewed as the heart of anything, let
alone airworthiness.
To many pilots, maintenance is only important
when serviceable aircraft are not available for
flight, or unserviceabilities in flight cause them
concern. After all, in the scheme of things the
status of piloting is more important than
maintenance.
Manufacturers would like us to believe that
their machines are rugged and reliable. Minimal
maintenance requirements are a design criteria,
after all, maintenance is so costly to aircraft
operators. So cutting the costs of maintenance
is more important than the maintenance itself.
The CAA treads the delicate path of policing
minimum standards so as not to unduly effect
the commercial environment, while keeping the
incident and accident rate at a politically
accept able level. So maintenance standards are
set by the political climate. The input of the
LAME to this process is minimal.
To operators economics is more important than
any other consideration. Maintenance is a direct
cost against revenue so it must be contained.
This containment however is a matter of
insightful judgement. The LAME's opinion is not
sought, instead a remote decision is made to
which the LAME must attempt to comply .
So who and where is the LAME in the scheme
of things.
I would suggest he is an overworked, underpaid, underappreciated and grossly undervalued
member of the aviation community. He plays no
part in the decision making process of senior
management. In fact I would be surprised if
management even considered consulting a
LAME for his opinion when an important
decision which will effect him is made.
Currently not only in Australia but worldwide
there is a crisis in the maintenance of airworthy aircraft. Rapid expansion in the demand
for air travel combined with unremitting cost
cutting, especially where maintenance is concerned, now shows itself in accidents which
should never have happened and t housands of
revenue hours which cannot be flown.
Aviation Safety Digest 143 / v
�Chronic undermanning, underpaying,
underskilling and undervaluing of the LAME
and the role he plays continues to lead to a
mass exodus of dedicated professionals from
the industry. At the same time management culture and practice which has presided over this
state of affairs wrings its collective corporate
hands. While admitting it has a massive problem it continues to dither in the dark of its own
twisted economic logic so far removed from the
workplace. To the LAME he wonders what
other company they work for .
Airworthiness IS the heart of aviation. It takes
decades to build a dedicated professional
workforce able to make it a reality. This reality
is rapidly leaving the industry and the community in general will suffer as a result.
Once again a world-leading Australia n industry
is deskilled by its own inepitude. Unable to perform and compete at such a basic level it must
turn increasingly to overseas suppliers of dubious quality and all that this implies to
Australia's reputation and economy.
The heart is rapidly leaving the LAME as he
looks for advancement and fullfilment outside
an industry blinded by shortsightedness.
Yours faithfully,
J .S. Seaburn
We hope the poster may help to keep the heart
in the LAME.
Dear Sir,
Yesterday 18-07-89 I travelled Du - Lilydale
by charter aircraft on business. Due inclement
weather beyond Eildon Weir we were forced
over the top (LSALT 5200) and began to plan a
diversion to Moorabbin. The duty controller for
our sector went to additional effort to radar
vector us away from high country and allowed
a descent earlier than would normally have
been available. During the descent radar confirmed us in close proximity to Lilydale. We
obtained a visual fix and subsequently completed a landing, thus enabling us to meet our
business commitments. Please convey our
thanks to the responsible operator for his
assistance.
David Honner
Thanks duly conveyed to Melbourne Radar.
Morals: 1. They were absolutely right to make
preparations for a diversion in good
time
2. The Air Traffic Controller is your
friend!
vi /Aviation Safety Digest 143
Dear Sir,
Whilst on a navex recently Melbourne asked us
if we would look for a C-150, presumably
forced down.
It turned out that the C-150 was uncertain of
its position and not forced down, as we had
expected. Anyway, before this was known, we
spotted a highwing Cessna on the ground a long
the search route. As I realised that the probability of spotting a Cessna on the ground was
extremely small, it seemed that the Cessna that
we saw could have been the subject of our
search. However, we couldn't be certain, since
the plane on the ground appeared more like a
Cessna 172 than a 150. I thought at the time
how positive identification could have been
easier if aircraft registration markings were
painted on the top of the wings. Co\,\ld this not
be a consideration, to aid those involved in SAR
operations?
On the issue of forced landings, I'm sure most
pilots would find it extremely inconvenient if a
landing had to be made in a high-tree-density
area. After my first navex over an area south
of La Trobe Valley, I realised this possibility, as
I flew over forest for the first time.
Although high-tree-density areas are not clearly
indicated on WACs, other charts, such as the
Tactical Pilotage Chart (TPC) series used in
Papua Niugini show the location of forest and
boundaries of clearings distinctively. Could not
this be an inclusion in the next WAC edition? If
not, could there be easier access to the TPC
series for Australian FIRs?
J uanda Ismail
Thanks for the constructive suggestions. Your
letter has raised considerable interest and comment here. This lengthy reply is therefore
justified:
Concerning aircraft markings, it was a requirement up to 1978 that markings should be displayed on upper and lower wing surfaces. Now,
however, Civil Aviation Regulation 17(5)
requires that nationality and registration
marks be located on the lower surface of the
wing. Advice is that the expense to operators
involved in painting both wings is not merited
by SAR considerations: in other words, the likelihood of a rescue attempt being compromised
in the fashion you described is sufficiently
remote. [this is not to say I wouldn't like the
aircraft I was aboard having two sets of identification on its wings - ed]
Perhaps far more value for money would be the
universal carriage of Emergency Locator Beacons (ELB), operating on 121.5. As you may
know, the Government, through the Federal Sea
Safety Centre (FSSC), has funded a COSPAS/
SARSAT LUT (Local User Terminal), located in
Alice Springs. Testing of this facility is in progress, and it is already giving good results
from beacons located all over Australia, as well
as from ships on the surrounding seas. During
Exercise Kangaroo '89 an Orion, way out over
the Indian Ocean, homed on to a fix reported
by the satellite to Alice Springs. The point is
that the aircraft could have been coming to
your aid, if you were unlucky enough to be in a
survival situation - BUT only if you were
ELB-equipped.
We'll run a comprehensive article on satellite/
ELB capabilities when the system is declared
fully operational.
There has been detailed discussion between
mapping authorities about including highdensity tree areas on the current charts. However, there were problems. The first (to get it
over quickly) is that the cost may be formidable - to the extent that it might make the
product far too expensive for the benefits
achieved.
Second is the impracticability of accurate
depiction of vegetation on l:lM charts (WAC).
A flight trial in 1986 compared LANDSAT data
with the visual picture at representative VFR
cruising altitudes; the results were no better
than 'mixed'. Whereas intensely cultivated
areas usually showed a good correlation
between 'map' and 'ground', scrub bordering
on to grassland, together with the more complex patterns of cleared and timbered land,
proved difficult to process, and produced an
uncomfortably 'cluttered' impression. Most of
mainland PNG that you referred to is either
thickly forested or tropical swampland - both
of which provide good contrast for any cleared
area.
The Australian ONG (also 1: JM) does make
some effort to delineate 'vegetation' (thick
scrub or heavily timbered woodland) and 'distinctive vegetation' (pine forest or mangrove).
These areas, where they are distinctive pockets
of vegetation, can be useful for position fixing,
but the ONG is of doubtful value for general
nav. purposes or planning a route clear of tall
timber. This drawback would of course apply to
the WAC as well.
The 1:500 OOO Tactical Pilotage Chart (TPC) is
much better, although the boundaries of normal
scrubland and wooded areas still need to be
treated with caution - not only may they
change between issues of the chart but the patterns of vegetation are depicted only in relatively level terrain, in order not to interfere
with the more important relief data.
A general point concerning the use of maps and
charts in the air (TPC, 1:500 OOO topo survey
or even a Shell road map): remember that Air
Traffic staff, by international agreement, have
the WAC as standard reference, and this is the
chart that is most frequently updated (radio
masts etc). So, if you try to describe a position
that may be on your map, but doesn't appear
on the WAC, ATC or FS may not know what
you 're talking about.
Having said all that, we agree that the TPC is
perhaps the favoured visual navigation aid. It
presents information in a very readable format, and the scale is appropriate for mapreading, even if you har;e to carry more sheets
than if you had opted for the WAC. Following
agreement by the RAAF to make the charts
available for civilian use, the CAA is currently
negotiating means whereby the TPC may be
sold through the Authority's outlets. Australiawide cover may take until around 1992,
though.
A plea to those who do use the TPC - the frequency of changes to Prohibited, Restricted and
Danger areas makes it very difficult for these
to be kept completely up to date on the chart.
Therefore DO NOT rely on P,R or D boundaries
as shown until you have checked them against
a VEC/VTC, ERG/ AC, DAH or other authoritative and current source.
oK .. r 1}.\1NK
l'M R1 &~I
Now ...
Aviation Safety Digest 143 /vii
�Aviation Safety Digest
143
AVIATION REGULATORY PROPOSALS
1
The following ARPs have been circulated since the last Digest:
89/4
CAR 214 Maintenance Training
89/10
AGA-7
Closed 30 Nov Responses under
consideration
Review Closed 9 Oct Responses under
consideration
Revelations
Restrictions
Requirements
Captain John Edwards
Airways Surveyor, Civil Aviation Authority
******************************************************
note: readers ' attention is drawn to !LS Some whats and whys, publis hed in ASD 139
AERONAUTICAL INFORMATION SERVICE AUSTRALIA
O! THIS IS NOT an article about power p lus
attitude equals performance, neither is it
about degrees lead and needle movement to
become established on the nominal track as if
you were on a railway line. Rather, this discussion is about how you should perceive a procedure, how it is designed, what operating
assumptions are made and what are the consequential operating limitations for the pilot if he
is to ensure separation from obstacles in the
manner intended by the procedure designer.
N
CURRENT DOCUMENTATION AND PLANNED NEXT ISSUE
DOCUMENT
CURRENT ISSUE
DAP(E)
14 DEC 89
11JAN90
4MAY89
11JAN90
OAP (W)
AGA 0-1-2
ADDGM
ERSA
AJP(BOOK)
VFG(BOOK)
AIP/MAP
VFG/MAP
DAH
14 DEC89
14 DEC89
14 DEC89
14 DEC89
14 DEC89
14 DEC89
NEXT ISSUE
PROCEDURE AND PERCEPTIONS
8MAR90
5 APR90
3MAY90
DISCONilNUED
(SEE BELOW)
8MAR90
3MAY90
3MAY90
28JUN90
28JUN 90
28JUN 90
Dates quoted are effectlve dates
1. CLASS I AND CLASS II NOTAM ARE TO BE CONSULTED WHEN USING ANY OF THE ABOVE
DOCUMENTS
2. The Issue of Aerodrome Diagrams effective 11 JAN 90 wlll be the last as a discrete document.
The diagrams wlll appear In the ERSA edition effective 8 MAR 90.
Issue 8 Date 11 JAN 90
)
viii / Aviation Safety Digest 143
The types and parts of procedures are the holding procedure, the approach procedure which
may be precision or non- precision, the missed
approach procedure and the standard instrument departure(SID). Except for the SID, the
purpose of these procedures is to enable the
pilot to take the a ircraft from the safety of the
en-route lowest safe a ltitude (LSALT) or a n
area safety a ltitude down into the more hostile
obstacle environment and to a point from which
a high probability of successfully completing a
landing s hould be ass ured. The missed approach
procedure is provided to enable aircraft that
cannot complete the approach due to weather
or an on -board problem s uch as a n avigation
receiver failure, or external navigation signal
failure or corruption, to regain the safety of the
more benign en-route environment via a safe
climb away.
The purpose of the SID is to provide a detailed
departure clearance routing that h as been
assessed to provide a path of known performance requirement safely past or over obstacles
until the safety of the en-route lowest safe altitude is reached.
To achieve these objectives, a procedure
designer must provide a series of connect ed volumes of air to provide safe passage for t he aircr aft. This air must encompass a ll the likely
errors of the navigation techniques required,
the inaccuracies of the manoeuvring aircraft ,
the inaccuracies of the transmitted signals, the
problems caused by meteorological factor s, the
inaccuracy of the obstacle data to be used and
the changes that are likely to occur to that data
before the next obstacle survey. These' portions
of air have to be strictly defined so that the
pilot knows exactly what is provided and so
that the designer can define the necessary volume geometrically.
Therefore, each portion of the procedure must
have a defined start point or fix , a specified
track or nominal track, a defined end point of
fix and vertical limits. In addition, precision
procedures must specify a path in the vertical.
Missed approach procedures and departure procedures a lso specify a minimum acceptable vertical path (This performance requirement is
expressed as a minimum gradient to be
achieved.)
To visualize what is provided, a non-precision
procedure may be thought of as a series of abutting boxes starting at the LSALT w ith each successive box lower than the last until the MDA is
achieved. A precis ion procedure is a nonprecision des ign until the final approach fix or
point (FAF / F AP) is reached; from there to the
decision altitude (DA) it is more like a sloping
half-funnel channelling aircraft to the runway.
Missed approach and departure procedures are
boxes w ith upward sloping bottoms, except the
acceleration segments, which are normal horizontal boxes. The diagram illustrates a typical
instrument approach .
A way to check the adequacy of any part of the
pre-procedure brie fing is to check to see if
enough information has been ident ified to
define adequately each s uccessive volume of air
to be used . If t his test is not satisfied, either a
vital point has been missed or insufficient
information has been provided. A further
element of an instrument approach briefing is
the action to be taken if a missed approach is
necessary from any point in the approach procedure. For reasons given earlier, some aircraft
may begin the missed approach before reaching
the missed approach point (MAPt). Usually, the
only course that is available to ensure the
safety of the aircraft is to follow the prescribed
tracks, even if only by DR techniques in the
event of signal loss, until the safety of the
missed approach altitude is reached.
DESIGN
In the horizontal, procedures have both straight
and turning segments and to define properly
the necessary areas designers must account for
the following:
•aircraft
- geometry;
- TAS;
- turn radius;
- aircraft inertia;
- pilot reaction times;
�Aviation Safety Digest
143
Aviation Safety Digest
143
PROFILE
• meteorological factors
- wind ;
• navigat ion facility performance and
interpretation
- t he ground system tolerance;
- the monitor tolerance;
- airborne receiver tolerance;
- flight technical tolerance - The t olerance
allowed for the pilot to int erpret and t rack
the signal; and
• the quality of the obstacle information
- the accuracy of the surveys available;
- the age and reliabilit y of t he surveys;
- the frequency of the surveys and the
likely effects of cult ural and vegetation
grow t h during the per iod between surveys.
I rI. . .., ,. . . ...'"
T. . ..
Ob!>laelecle.,•ncedesignedintolha procedurelo • ltowro1tolt1 ances
~::::::::.~· .m "" .......
········~· · ···· ·· · ·
Transl~l ubslaclu-
Tr•lns.
S hlp<J,V• l'llcleselc._
Acc..111auon
Segmenl
In t he vertical, the designer accounts for the
following:
lnfll1I
HOlOING PJIOCEDURE
NON- PRECISION S EG MENTS
MISSED APPROACH
PAECtSION SEGMENT
TYPICAL PROCEDURE PROTECTION (NOT TO SCALE)
M IS SED APPROACH
SEGMENT
ITEM
ARRIVAL
INITIAL
INTERMEDIATE
FINAL
: INITIAL
INTERMEDIATE
FINAL
AIRCRAFT
en route
manouevring
changing configuration
speed & positioning
alignment &
descent tor landing
: transitioning to
• missed approach
climbing at
stabilised
speed
accelerate &
climb
NAVIGATION
guidance req'd
guidance required.
D R for max 10nm
guidance inbound
10 FA F
guidance shall be
provided
: not possible
can use availa ble
guidance
can use
guidance
LENGTH
as required
as req'd by height loss
between 5 & 15
(optimum 10 nm)
normally 6 nm to landing
surface or MAPt
: MAPt or timing
• tolerance + 15 sec
: + tailwind
a s required to
achieve 164 ft MOC
as required
OBSTACLE
CLEARANCE
en route
1000 ft
500 ft
( 1} at precision approach OA
initiate missed approach;
( 2) at non-precision MDA do
not go below (300 ft)
: as !or final
• segme nt
100ft
164 ft then
300ft
( 1) ILSILLZ 2.5-3 .5 degrees
(2) radar 5% (6.5% max)
(3) VORINDB (+FAF)
5% (6.5% max)
•
•
: level
2.5%
2.5% then 1%
._ __ - - - - - - - - - - - - - ---- -- - - - - · - -- -- - - - - - - - - - : level
max 5%
max 5%
(1) using tracks
(2) part of racetrack
or reversal procedure
( 1) exces::;ive length
(2) mountaif)ous terrain
(3) remote altimeter
setting
(4) forec'ast altimeter
setting
: ( 1)~ requirement to
distracted by speed &
configuration changes
paying attention
: climb
GRADIENT
Norm al
Maximum
OPTIONS
COMMENT
(Crew alertness)
4% (243 fVnm)
en route
flat
• --- - - - - - - - - - - - - - - - - -- - - - - - - - - - - --- • •
then flat
en route
8% (486 tvnm)
5% (304 tvnm) segment
en route
en route
(1)
(2)
(3)
(4)
using track • DME arcs
radar vectors
racetrack procedure
reversal procedure
en route
INSTRUMENT APPROACH PROCEDURE SUMMARY
:
:
:
chan~e ? lreclion
•
perm1ss1ble
• (2) MAPt
:
(a) facility
:
(b) fix
•
(c) distance
.
.
• concentraung on
: establishing .climb
• & configuration
~ changes
( 1) may alter !rack
15 degrees maximum
(1) turns OK
(2) accel.
segment 6nm:
300ft MOC:
1% dimb grade
relaxed enough
to navigate
accelerating to
en route dimb
configuration
- relaxing
• aircraft
- geometry;
- minimum specified ascent gradients;
- maximum descent gradients;
- altimet ry effects;
- a ircr aft iner tia and t ime needed to change
configuration;
- pilot r eaction times;
• meteorological effects
- t he qu ality of QNH data, ie reported or
forecast QNH;
- t h e QNH inaccuracies and handling difficult ies exp erien ced in mountainous areas;
• navigation facility performance and
interpretation
- as befor e; and
• th e quality of obstacle informat ion
- as befor e .
It s hould be noted that the designer cannot
allow for eit h er pressure err or correction
(PEC), as t his is sp ecific to aircraft type, or
temperat u re error correction , as this is a local
variable effect. To provide an allowance for
such effect s w ould require large values; t hese
would prove unnecessarily punitive to many
operat ions. Th erefore , such corrections are the
r esponsibility of t he pilot.
The designer supports t he above information
with the following assumptions:
a. aircraft will not descend vertically, but will
be flown in a way that gives a descent gradient
w hich is ext remely unlikely to exceed 15%;
b . during the different p h ases of a procedure
the pilot is capable of differing degrees of navigation and t he a ircraft should only be required
to perform certain manoeuvres. A summary for
an instrument approach procedu re is shown in
the t able; and
c. the pilot will fly the nominated tracks as
closely as possible. This assumes that where
t r ack guidance is not pr ovided, the pilot will
use best known drift corrections except when
being radar vectored.
Two assumptions need a little discussibn.
a . Descent gradient. The provision of a descent
gradient assumption is necessary, as the fix at
the beginning of the segment is freq uently
marked by the passage of facilities which are
sited on hills, or it is selected to mark the passage of a limiting obstacle. Consequently, the
assumption allows the designer to consider most
facility sites or the obstacle as an obstruction in
the segment being exited rather than an
obstacle in the segment being entered.
b. Tracking accuracy. Obstacle protection is
provided on a statistical basis. Therefore, if the
t r ack or nominal t r ack is not followed as
closely as possible, the pilot is deliberately
allowing erosion of the design safety margins;
there is no provis ion in the margins for this
source of degradation . What this means in practice is t hat for the majority of t he time tracking
deviations should be less than half the prescribed tracking tolerance, an d only very rarely
(less t han 5% of occasions) should the
indication show a deviation from track greater
than 2/ 3 of the prescribed tolerance.
The factors and assumptions listed are all
straightforward but the procedure designer
must be able to reduce them to geometric
shapes containing the maximum and min imum
possible positions of the normally operating aircraft at any t ime during the procedure. The
designer must a lso use a irsp ace efficiently if
unnecessary penalties are to be avoided . These
con straints lead to interesting solutions and
requirements, some of which are discussed
below.
Hold ing and racetrack procedures. Here are
some questions for those w ho hold instrument
ratings:
1. Why are the entry sector bound aries defined
by heading and not track?
2. Why does AIP / IAL require that the outbound
track be parallel to the inbound t r ack, ie only
one drift allowance, rather than a non-parallel
track that would allow for t he dr ift effect
accumulated in t he turns at both ends of the
pattern plus the d r ift effect on the outbound leg?
3. If your outbound track is goin g to cross the
procedu re's inbound track what are you
r equired to do?
4. In a sector 2 ent ry, ar e you r equired to intercept and track t h e 30 degree offset after passing the fix or do you merely adopt a 30 degree
offset heading?
�Aviation Safety Digest
143
Answer 1. The procedure designer needs to
know the maximum number of degrees through
which the aircraft might turn if he is to be able
to draw up the protection area. This is not
possible if the sector boundaries are defined by
track, as the drift allowance (which is variable)
might increase the time spent in the turn
beyond that provided in the design. Therefore,
sector entry boundaries are defined by heading.
Answer 2. To minimise the airspace required
for the procedure, the designer applies drift
corrections throughout the procedure. This
means that only the drift allowance experienced
on the outbound leg is provided for in the
design of that leg. Consequently, flight procedures that apply a greater drift allowance, up
to 2 or 3 times, to the outbound leg invalidate
the design and pilots may not assume that the
manoeuvre will be contained within the prescribed airspace.
NOTE: A subsequent AIP /IAL requirement in
the procedure is 'execute a 180 degree turn to
realign the aircraft on the inbound track'. This
requirement does not require re-alignment
w ithout passing through the inbound track.
Some wind conditions will require the pilot to
pass through the inbound track before
re-alignment and this has been provided for by
the designer.
Answer 3. The pilot has no track guidance on
the outbound leg, so it is possible that the
achieved track may cross the required inbound
track. The probability of this occuring in a
holding procedure is low, but it is likely with
the longer outbound times permitted in racetrack procedures. In order to conserve airspace,
designers recognise that pilots have sufficient
information available to identify such an occurrence and assume that pilots will not cross the
inbound track but will adjust their achieved
track to continue outbound on the reciprocal of
the inbound track until the prescribed t ime or
position is achieved. The procedure should then
be completed in the normal way and in the
direction specified.
Answer 4. To minimise the airspace required,
you are required to intercept and track the 30
degree offset outbound.
Approach procedures. More questions:
5. Is it safe to join the procedure below the
initial approach altitude, provided that the altitude at which you jOin is higher than the next
descent limit in the procedure?
6. In a reversal procedure , is it safe to shorten
the outbound leg and turn early?
7. Why does the AIP /IAL caution against
descent rates in excess of lOOOft/min?
Answer 5. NO! because the vertical and lateral
obstacle clearance provided to protect the joining manoeuvres will no longer be assured.
Answer 6. NO! because the protection for the
turn is provided on the assumption that the
turn is initiated at the prescribed fix. Turns
initiated early might not be contained within
the normal protected area, as the areas are
usually widest at the planned turn point.
Answer 7. The obstacle clearance provided contains some allowance for excursions below the
prescribed descent limits. However, to ensure
the best operational advantage in the procedure
and at the DA or MDA, these allowances are
small and not sufficient to accommodate the
excursions associated with arresting high rates
of descent.
Undoubtedly, briefing rooms, crew rooms and
bars can produce similar informative discussion
on missed approach and departure procedures
as well as expanding the above quick quiz.
However, the usual warning against 'informal'
intelligence must of course apply!
LIMITATIONS
Beware the
big bang
The interface between the procedure designer
and the pilot to ensure that both have a
common and unambiguous understanding of the,
procedure are the API/IAL requirements for:
• IAS;
• average achieved bank angle;
• tracking tolerances;
• fix and timing rules;
• joining procedures;
• rules for drift application; and
• special s ituation rules such as those applying
to holding in question 3.
CONCLUSION
The source of the rules and techniques used for
instrument procedure design by the CAA have
been developed from a considerable international experience base. Therefore, it is
unlikely that any s ingle pilot would know sufficient or be able to access the required data on
the spur of the moment to take a liberty with a
procedure or the rules and yet be able to ensure
the safety of the operation. However, the rules
and the underpinning experience are not sacrosanct and are continually subject to review by
the CAA and ICAO. Therefore, change and variation are possible but all proposals need
thorough documentation followed by exposure
to a w ide range of relevant discussion and
experience before they may be attempted in
practice.
More immediately, in preparing to fly a
procedure, the pilot can increase the safety of
his operation by visualising what the procedure
is doing for him and ensuring that he has been
given and identified the necessary elements of
information for each segment of the procedure.
We should be mindful that designers are not
infallible and that even an error in the proofreading or printing of t he chart could mean that
a significant element of information is omitted
or corrupt; the pilot must endeavour to identify
the problem before commencing the procedure D
0
'Dear Sir,
On numerous occasions I have had cause to
contact your Department with regard to helicopters flying over this mine site. On the most
recent occasion, two different helicopters flew
over, one at about 600 feet and the other at
only 200 feet. This last overflight was but 15
minutes from a blast... '
This extract is from a letter written by a mine
manager to the CAA. Further excerpts emphasise the dangers of flying low over mines:
' ...up to seven tonnes of explosive are used in a
single blast. '
'... a safety fuse of about three minutes' duration
is used. Once the fuse is lit, there is no safe
way to stop the blast. '
'. .. blasting at surface level is a regular
occurrence'.
The Chief Government Engineer for t h e NT
Department of Mines and Energy also was
sufficiently concerned to write. Here is part of
his letter:
'Open cut mines and quarries are recognisable
from the air, and may be blasted at any time,
although usually by daylight. However, pilots
should be suspicious of even apparently abandoned mines; these are sometimes reopened,
and some quarries are worked very
infrequently. From the air, the preparations for
blasting will not be visible. A mine that
appears deserted might in fact be cleared for
blasting. We have no information on the height
of trajectories of rock fragments, but opinion is
that they could rise at least to 500 feet, and
they have been known to travel 500 metres
horizontally.'
A recent TV travelogue was filmed from a balloon in Australia. The balloon was cruising at
about 100 ft on a beautiful morning when suddenly t he ground dropped away into a huge
opencut mine. Serenely, and with hardly a
sound, the balloon floated over the busy scene
below. An accident was averted only because
the very active mine happened not to be blast ing at the time.
Balloons have raised the ire of the oil industry,
too, although the message is applicable to all
low-level aviation. The balloon/ oil incidents
involved flight over bulk storage tanks. Fort unately, the tanks were not venting at the time.
A similar danger can be encountered with seatankers. Some liquid-gas vessels have tanks up
to lOOft above sea level, and they vent automatically, at high pressure to ensure the gas
clears the crew's living quarters. The tonnes of
vented gas are highly flammable and present a
major hazard to low-flying aircr aft.
Luckily, this type of vessel is not a frequent
v isitor to Australian waters, and although
tankers regularly put into Westernport Bay,
Spencer Gulf and Dampier , they rarely vent gas
when at sea: However, there are at least three
occasions when all liquid-gas tankers vent:
approaching dry-dock, preparing for a change
of cargo, and, of course, in emergency. Note
that none of these circumstances need be
readily obvious to an aircraft.
So, low-level flight does present hazards extra
to birds, unexpected fly ing machines, wires and
t urbulence. And, of course, close to the ground
leaves less time for action in an emergency.
Therefore beware the big bang! Only go as low
as is lawful, and certainly no lower than is
necessary. And if you plan to fly down there at
the legal limit, do yourself a favour and learn
where the hazards are likely to be, and exactly
what sort of danger might confront you.
The picture shows a representative opencut
mine - very recognisable from a reasonable
(and safe) alt itude, but liable to creep up on
you unobserved if your horizon is only some
twenty miles away, and your attention is fully
occupied by the ground just a head! D
�Aviation Safety Digest
143
Give military jets
•
a miss
F
OR SOME TIME now the CAA, RAAF and
Agricultural Aviation Industry have been
seeking to minimise potential conflict
between military jets on low jet routes (LJR)
and civil aircraft carrying out agricultural
operations.
Most LJR operations take place below 500 feet
AGL, both day and night, just the right height
to contribute to the premature ageing of the
agricultural pilot fraternity. Several agricultural pilots who have had encounters of the
close kind with military low jets (MLJ) would
doubtless testify that relying on the 'see and be
seen' principle is just not good enough.
Aviation Safety Digest
143
While efforts to date have concentrated largely
on development of a satisfactory method of
notification of LJR operations to civil operators,
there is also a need for RAAF crews to be
aware of conflicting agricultural operations
when flight p lanning LJR operations. A better
system of notification is also required in this
respect, and at the time of going to press the
plans are as follows:
Agricultural operators who operate in areas of
likely LJR activity are encouraged to notify
directly to the RAAF the details of their
intended operation, giving as much advance
notice as possible. As LJR operations are generally planned and notified to the CAA on the
afternoon of the preceding day, advice of
planned agricultural operations should also be
passed to the RAAF on the preceding day to
maximise the benefits of this information to
both parties. The RAAF has agreed to provide
008 telephone numbers for Amberley and
Williamtown. These numbers will be published
in ERSA, but in the interim will be notified by
NOTAM Class I and to AAAA as soon as they
are installed, hopefully by the time that you are
reading this article.
All notified agricultural activity is plotted in
the RAAF Flight Planning rooms, on maps
which crews are r equired to check before flight.
If the MLJ is to avoid you, timely notification is
a must D
Cessna 172M, 29 January 1989
Accident
response
0
Piper PA23-250, 23 March 1989
The grass was 10-15cm and wet on the firm
750m strip. The pilot had not previously operated a PA23 in wet conditions. The aircraft was
held on the brakes under full power, with 10
degrees of flap selected. During the take-off roll
the pilot became concerned at what appeared to
be a slow rate of acceleration, but put this
down to the characteristics of the type he was
flying; he considered aborting, but there seemed
to be too little strip remaining to stop the aircraft successfully.
The aircraft became airborne about 20m from
the upwind end; shortly afterwards the port
wing contacted vegetation, slewing the aircraft
left and breaking the fuselage just aft of the
cockpit. The 'take-off' ended in a mangrove patch.
The take-off performance chart for the aircraft
indicated that the strip was of sufficient length
for take-off under dry conditions. However,
there was no information available to the pilot
as to what allowance should have been made
for long wet grass. The aircraft probably
became airborne before the correct speed had
been reached.
BAS! recommendation
ASD produce an article highlighting the effect
of variable ground conditions on light aircraft.
CAA action
We have reproduced below, courtesy of the UK
CAA 'General Aviation Safely Information
Leaflet', a table of variables affecting, particularly, light aircraft take-off performance. It is
emphasised, though, that this accident appears
to be pilot error: AIP AGA 6-8 Section 9, para
9.2.1, and VFG 81-11 warn of substandard runway surfaces.
FACTORS ARE CUMULATIVE AND MUST BE MULTIPLIED
I
TAl<t=.f'IC:C:
CONDITION
INCREASE IN
DISTANCE
TO HEIGHT
SOFT
FACTOR
Al\Jnll\J~
INC REASE IN
LANDING
DISTANCE
FROM SO FT
FACTOR
20%
1.2
10%
1.1
10'4
1.1
5%
1.05
An lnctMM of 10 deg C In ambient
temperature
10%
1.1
5%
1.05
Dry gra..• ·Shor~ 5" (13an)
- Long,b - 5" & 10'"(13·2San
20%
25%
1.2
1.25
20%
30'4
1.2
1.3
Wet gron· · Short
25%
30'4
1.25
1.3
30%
40'4
1.3
1.4
uphil
10'Y.
1.1
opood
20%
Sottground or s~
2 5%
or mote
A 10% increase i"I Mt'oplane weighl
Al'lincrMM of 1000ft ii aecodrane
oltilJdo
• Long
A 2% Slopo"
0
c
dowmll
IOo/,
1.1
1.2
20%
1.2
1.25
25%
1.25
+
A la.l~nd component of 10% of Uft:-oH
NOW USE ADDITIONAL
SAFETY FACTO RS
+
1.33
«more
1.43
Ill data Is unlocloredl
NotM: "Effect on Gtound A..r\/Rdl will be great•
My dwiation from normal opera Ing tecmtques ~ llkety to rM IAt In an lncreo.sed distance
The aircraft was hired for a short local
pleasure flight. After take-off, at approximately
100 feet and 60 kt the engine began to run very
roughly. The pilot landed back on the strip,
started to brake but realised he wouldn't stop
in time so applied full power in an attempt to
clear the boundary fence. He didn't make it; the
aircraft hit the top wires and an adjacent hedge
and stopped within 50 metres, with nose gear
detached.
Witnesses reported that the take-off was
attempted a very short time after start-up.
There was evidence of a tailwind component of
around 10-20 kt during take-off. Carburettor
icing was excluded as a factor, but examination
of the engine revealed a number of faulty
spark-plugs: an engine specialist confirmed that
this could lead to rough running.
BAS! recommendation.
As the strong suspicion that the engine was not
up to operating temperature at take-off, faulty
spark-plugs and the undoubted existence of a
tailwind were all factors in this accident, the
Digest should highlight these points.
CAA action
The report speaks for itself: downwind
components dramatically increase strip length
requirements and engine inspections and operating temperatures are specific and vital.
Cessna 182P, 14 June, 1989
Run-up, taxi and take-off - normal. At 200ft
the engine failed completely. A landing back on
was attempted, but the aircraft touched down
on the overrun, entered a muddy area, and
overturned. An inspection of the fuel system
disclosed that the engine had stopped due water
contamination of the fuel supply to the carburettor. The fuel cap to one tank had a defective
seal.
The aircraft had been refuelled two days before
the accident. In the meantime, heavy rain had
fallen and the pilot found a significant amount
of water in the fuel system during the pre-flight
fuel check. Fuel was drained from the system
until no water was present in the fuel sample.
The pilot was not aware that water accumulated in the fuel tank may not be completely
cleared merely by a fuel drain. Consequently,
he did not 'rock' the aircraft to ensure that all
the water was clear.
BAS! recommendation
That it be emphasised that aircraft parked on a
slope and aircraft with bladder type fuel tanks
can have water in their fuel systems even
though the fuel drain check strongly indicates
that the system is clear.
CAA action
There is really nothing to add to this warning
- be diligent in knowing and carrying out all
the checks; after all, it's your life! D
�Aviation Safety Digest
143
Canyon flying
Pilot contribution by P J Little
T WAS WITH eager anticipation that the Monday morning arrived for my business trip to
Cairns from Bankstown in the company of a
very old friend who was to spend the week
travelling around with me. We had planned to
make Mackay in Queensland the first night's
stop then proceed to Cairns the next day, stopping on the way home for a night at Hamilton
Island, and then flying Hamilton Island to
Bankstown on the Friday.
However, Monday morning dawned with overcast conditions and a forecast of occasional to
frequent thunderstorms along the coast from
Sydney to Cairns. Our friendly Met. man at
Bankstown suggested that west of the ranges
was clear and provided we could make it over
the ranges and back to the coast we would have
little else to worry about. I planned IFR to
Roma via Mudgee, Coonamble and Walgett and
then to Mackay via Emerald.
We had an uneventful flight to Roma, refuelled
man and machine and again departed, knowing
that thunderstorms are worst in the afternoon.
Our anxiety level was soon raised when Brisbane started to issue reports of thunderstorms
in its vicinity, the reports being frequent and
varied but mostly issued with a kind of
urgency. We had completed 90 miles of the 182
miles to Emerald when the cumulus started to
build and we were forced to climb to FL180 to
remain on top. Then I saw it on the weather
radar about 60 miles ahead: green with a yellow centre. As we approached it was directly in
our path towering 6 or 7000 feet above us and
then going what seemed to be all the way to the
ground, white and rounded on top, crisp and
well defined, all sparkling in the sunlight like
new fallen snow then dark and sinister-looking
down below, the murky grey and black patches
interspersed with shafts of rain or even hail. As
the weather was moving west to east generally
and as it appeared clearer to the west we made
a 70 degree turn to the left and tracked west
around the storm, watching it on radar as we
passed. In the nine months I had owned the
weather radar this was the first time I had
used it in earnest and I was fascinated to see
the storm appear just as the book said it would.
It had a red centre (hail), about five miles long
and three miles wide, the overall storm being at
least 10 miles long by radar. And much longer
visually.
Despite a considerable diversion to the west we
arrived at Emerald only one minute late, thanks
to a tail wind, and headed towards the coast
and Mackay, still at FL180, and in clear skies.
I
However, about 80 miles out of Emerald the
way ahead was again blocked to both the north
and the south for a considerable distance either
way. The weather radar, which I was beginning
to have confidence in, showed a gap through
the middle all the way to Mackay. This was not
entirely supported by visual inspection, as the
apparent gap appeared to end in blackness.
Regardless of this, since the storm stretched at
least 50 miles either way, I decided to at least
have a look and, as predicted by the radar, I
found a gap between the cells that enabled me
to descend into Mackay in clear skies.
After landing, my passenger commented on
what a smooth flight it had been and when I
thought back I realised that although we had
passed through the most dreadful weather
maybe there had hardly been a bump. Was this
due to the radar? Maybe, maybe not, but I
know I would not have attempted the trip
without it. That night on the television we saw
torrential rain in Sydney with local flooding
and also the damage storms had wreaked in
Brisbane and various other cities that day. One
of those upper air troughs which seem to be
used to describe any weather that was not forecast had appeared from nowhere inland from
the eastern seaboard and was creating havoc.
The balance of the flight to Cairns was
uneventful. The trip from Mackay to Cairns
was flown in the morning in clear skies. The
return flight to Hamilton Island was not quite
as good because although it was the morning
we ran into two larger cells just north of
Townsville but again used the radar to successfu lly negotiate a path between them. However
our trip to Sydney was to be another story.
I had planned our flight from Hamilton Island
to Bankstown direct with fuel stops at Rockhampton and Archerfield. The forecast, however, indicated few problems to Archerfield, but
beyond to Bankstown it was 'isolated CB 2000
coastal 4000 inland tops 36000 becoming
occasional after 05Z with SCT CU 4000 tops
1.8000 and SCT AS 10000-18000' and TAF for
Bankstown which included 'PROB 20 INTER
04-11 3000 95TS 3 CB 040' together with a
special on Sydney at 22Z 'Wind 180/ 10 Vis
7000 rain 3/ 8 500 8/ 8 1000'. I decided to proceed to Archerfield and review the situation there.
We arrived at Archerfield after skirting two
thunderstorms en route Rockhampton and a
check with briefing revealed that the actual for
Bankstown was well above minima but that
thunderstorms were still forecast after 05Z. The
en route thunderstorms were also still forecast
although they could not provide details. A
glance in the general direction revealed nothing
untoward. We therefore departed again hoping
to reach Bankstown by 0615Z, well after the
0400 for thunderstorms on the TAF, and cruising at a:n altitude of FL140.
Within 50 miles of Archerfield our radar began
painting colours and visual inspection showed a
massive build-up 20 miles ahead. At this time a
0
0
c
DC9 above and ahead of me reported diverting
to the west, so I followed. It was becoming
obvious that FL140 would not clear the lower
cloud so we went to FL160 and then to FL180
and even so we were concerned over the magnitude of the diversion necessary, when the DC9
reported he was 110 DME Brisbane and returning to track. I was about 90 DME at this time
and still tracking west. At exactly 110 DME I
rounded the storm to see a gap to the east and
was able to turn to achieve a 30 degrees intercept of track. We now entered an eerie sort of
canyon with large build-ups all around us but
the way ahead clear, although the space was
layered with altostratus layers above and some
below us. At times visibility to the left or right
was completely obscured by layers of altostratus. My passenger chose this time to go to
sleep, thus adding to the eeriness. Then up
ahead I could see a complete wall with no
breaks and it was becoming apparent that I
would have to penetrate it. The weather radar
showed clear although registering cells off in
the distance, but just then a high flying aircraft
on track Williamtown to Casino at 34000 feet
reported he was diverting west to avoid several
build-ups. I wondered how high they must go
and whether I would be flying into them. I
asked him what it looked like on my track from
Mount Sandon to Singleton and he said it
appeared to be clear with one or two cells
further west. The radar was still showing clear
so I plunged into the cloud only to emerge a
short while later in almost clear skies. After
dodging one more cell we arrived at Bankstown.
My friend woke up during the descent and
remarked again what a smooth flight it had been.
If you can aj'ford a weather radar, this,
another of Mr Little's excellent contributions,
should convince you to splurge. A good radar is
a marvellous tool and will help you get the job
done safely when others must call it quits.
Notice that Mr Little says he would not have
undertaken the trip without his radar. Notice,
too, that he compares the visual size of a storm
with the radar size - without the radar you
may well have to divert 50 miles further.
A word of caution, though, on radar and storm
scopes. They are aids, useful tools to help you.
But they are not infallible. I'm sure all IFR
rated pilots have tales to tell. I well remember
flying into cloud which gave no paint on our
radar. Within seconds, we were icing up and
losing airspeed. At the point where I was about
to add power, we popped out into the clear
again. We were in it for only about 30 seconds,
it did not paint on radar, yet we iced up
unbelievably.
And a word of caution for the no-radar pilot.
As you can see from this article, radar fitted
aircraft have a big advantage over non-radar
fitted. Do not be tempted to push on just
because you hear someone else getting through.
If you have doubts, ask ATS or the other aircraft, but make it clear you are not radar
equipped.
Mr Little has another very good technique to
complement the use of radar. He communicates
very well. He listens to other aircraft near him,
learns from their reactions to the weather and,
when in doubt, asks for advice.
Through careful planning and good communication we can all make the right decision when
it comes to lousy weather. Adding the extras Command Instrument rating, storm scope,
weather radar - will give us more confidence,
a greater margin of safety and enable the job to
be done more often 0
�Aviation Safety Digest
143
TO
CENE: Ch arlene and Ralph in t heir Cessna
172 flying southeast down t h e Light Aircraft Lane into Moorabbin for the first time.
S
AIR
Charlene: Time to call inbound . . . Moorabbin
Tower t his is Cessna ZZZ Brighton,
one thousand five hundred, inbound,
received information Sierra.
follow , and those Navajos are pretty
fast, better make it a reasonably close
circuit.
Ralph:
OK . . . Those runways look pretty
close together and there's three of them!
Charlene: Let's check ... They're using runway
35, so if we extend the runway
centreline to 8 miles we're to the west
of the line, so we call 123.0, the western frequency. Runway 17 is obviously the same.
Speaker: ZZZ Moorabbin Tower , join downwind.
Ralph:
Charlene: Yeah.
Charlene: Nah, there used to be three under t he
old system, but now there should only
be two ... see ... the middle runway
doesn't have any runway markings on
it. It must be used as a taxiway now.
Ralph:
Charlene: ZZZ
Ch arlene: (examining the Visual Terminal
Chart) Let's see ... Moorabbin ... a
3 mile zone up to 2000 with a 5 mile
frequency buffer .. . inbound point
from the north-west iiiiiiis .. .
Brighton ... j ust south of the outbound point ... Point Ormond ...
we've also got Westgate Bridge, Point
Ormond and Station Pier, t he routes
in and out of Essendon ...
Charlene: Well ... extending the centreline ...
it passes to the north of Point
Ormond and Brighton, and we're west
of it, so we'd still call the western
frequency.
Ralph:
Ralph:
Ralph:
Charlene: If we fly down the coast and head
east we'll be nose to nose with aircraft on crosswind, t hat doesn 't
appeal to me.
Speaker: QQQ.
Ralph:
Speaker : ZZZ, clear to land.
Sounds like a pretty bu sy area!
Charlene: Yeah, it looks like the combination of
t he Melbourne Control Zone and t he
military restricted area funnels a lot
of traffic through this area. We're at
1500 now, and we should be at 1500
at Brighton.
Ralph:
What do aircraft flying from
Moorabbin to Essendon do?
Charlene: There's a new procedure. Aircraft flying down t h e Lane like us are at
1500, and going back we'll be at 2000,
so going from Moorabbin to Essendon
via Point Ormond they'd climb to
2000 so they aren't nose to nose with
us at 1500.
Ralph :
I suppose that going from Essendon to
Moorabbin they fly at 1500 to match us.
Charlene: Yeah, that's r ight.
Ralph:
Better listen to the A TIS.
Ch arlene: OK.
They listen to the ATIS:
'Moorabbin Information Sierra, arrivals and
departures east runway 35 right frequency
118.1, arrivals and departures w est runway 35
left frequency 123. 0, wind 3 60 degrees 10 knots,
QNH 1013, temperature 14, CAVOK. Ulhen calling ready, nominate direction of departure,
Moorabbin information SIERRA.'
Ralph:
What's this arrivals and departures
east and west?
Charlene: GAAP's two aerodromes back to back,
two frequencies, two controllers.
Ralph:
Which one do we call?
Ralph:
Whatifthe duty runway was 13 or31?
Downwind eh?
Should I fly dow n the coast, then east
to intercept the normal downwind
turning point, or s hould I fly straight
ahead to intercept the highway heading SSE?
Yeah, you 're r ight.
Speaker: QQQ, approaching the coast, preceding Cessna unsighted.
Speaker: QQQ, the Cessn a is now on base.
OK, what about 04/22?
Charlene: Let's see ... there's only one runway
in that direction so there would only
be one frequency and one controller
... the frequency would be on the
ATIS, but the old frequency when
Moorabbin only had one controller
was 118.1, so I'd use that one if I was
them ... that's the eastern frequency.
Ralph:
Can you work out the frequency for
all entry and exit points from the
runway in use, using the extended
runway centreline method?
Charlene: Don't forget to be at 1000 at the zone
boundary.
Ralph:
)
Charlene: Yeah. SAPS say that when 17 / 35 is
being used Carrum is in the western
circuit.
Ralph:
Ralph:
Speaker: AAA, ready for the training area.
Charlene: The training area is down to the
south-east so AAA w ill be departing
on downwind. We'd better try and
find h im, t he tower doesn 't think he's
traffic, but we have a joint responsibility for separation , so let's look . . .
There he is, getting airborne, we'll be
well ahead of him.
You mean there's the usual exception!
Charlene: ZZZ ... don't d awdle on t he run way
Ralph, t he Navajo is going to be r ight
behind us.
Right.
Speaker: AAA, clear for take off!
Charlene: Almost!
Ralph:
OK, I'll follow t he highway.
Speaker: QQQ, s ighted.
Right !
Charlene: The runway is three times as wide as
the sealed surface in the middle ...
see the white gable markers ... and
the yellow lines on the t axiways?
They mark the edges of the runway.
Ralph:
So w hen I land I'm not clear until my
tail has passed the yellow line.
Charlene: Right.
Ch arlene: Nice landing Ralph.
But it's not if you use the extended
runway centreline method?
Speaker: Moorabbin Tower this is Navajo, QQQ
Shoal, one thousand five hundred,
received Sierra.
Charlene: No.
Ralph:
Thanks Ch arlene.
Speaker: QQQ, clear to land .
Ralph:
I wonder why they changed it.
Charlene: Let's have a look ... 17 / 35 .. . extend
centreline Brighton's to the west and
the Academy, GMH and Carrum are to
t he east. Yeah, I see ... if it was left
like t h at you'd have the eastern circuit being ver y busy, and the western
circuit very quiet. Putting Carrum in
the western circuit evens out t he
workload on the controllers and
reduces congestion in the eastern circuit. Whaddya reckon?
Ra lph:
Speaker: QQQ, Moorabbin Tower , track for a
straight in approach, you are number
two, follow a Cessna joining
downwind, report crossing t he coast.
Sounds reasonable.
Speaker: QQQ.
Charlene: OK, we're clear, better call on the
ground frequency . .. ZZZ.
Speaker: QQQ.
Speaker: ZZZ.
Ralph:
That's us!
Ralph:
0
Charlene: Yeah! Time to report downw ind ...
ZZZ downwind.
That was pretty easy.
Speaker: ZZZ number one.
Charlene: Yeah, it is if you try to make sense of
the system and keep an eye and an
ear out.
Charlene: That means there is no-one for us to
Ralph:
No worries D
�
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143
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1990
-
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Text
ASD 142
X - extra hazards
check before
clean-up or
recommence
t
SPRING 1989
~~I~
'"II!· 1111~ L3
•!!!•!!iii·
...
�Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots). registered aircraft
owners and cenain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Statement by Phil Bowen
Contents
Spring -
Group General Manager, Airways Operations
the season of change
Wire Survival
Dlstributees who experience delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Civil Aviation Authority
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
t
Mid-air!
Mid-air collision over Cerritos
T
HE AIRWAYS Operations Group is the commercial heart of
the Authority. The Group has about 5,000 staff (mainly air
traffic control, flight service, rescue and firefighting
service, and professional and technical support staff). an
annual turnover of about $500M and a capital budget of about
$100M per year.
With the exception of about $3M per year from the
Government for search and rescue, the Group's revenue is
derived from industry charges.
The charter of the Airways Operations Group is to deliver high
quality services which meet industry demand and safety
requirements, whilst containing and if possible reducing
charges.
The main objectives of the Group are to:
1. Streamline air traffic management procedures
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Au$1ralian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALJA
Telephone (062) 95 4411. Telex AA62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops In
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority nor should they be construed as
regulations, orders or directives. The anlcles
are Intended to serve as a basis for discussion
and even argument in an effort to identify and
resolve problem areas and potentially
hazardous situations.
Unless otherwise noted, anicles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety and
will make editorial changes to submissions in
order to improve the material without altering
the author's intended meaning.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.0. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Telephone (062) 68 6319
10
Could it happen to me?
1 •~ Accident response
1"
2. Provide services to the aviation Industry on a more
commercial basis
Nil Defects
There will be a closer focus on the services provided to
industry with a view to ensuring that they meet the industry's
requirements in a commercial way. A business proposal for the
future provision of operational control services is nearing
completion un~er the guidance of Captain Mike Terrell,
formerly Operations Manager with Ansett.
1t
Aspartame -
1i
Frontal Weather
18
Airflow
It Is proposed to adopt a similar approach to examinations of
the other services provided by the Group. An important issue
which will be resolved in this context is the provision of
Rescue and Firefighting Service Units at capital city secondary
airports.
2
Aquaplaning
Productivity performance indicators are being developed to
enable the efficiency of the Group to be monitored and, where
21
A sequence of events
Editorial
not for the dieting pilot?
3. Improve Productivity
23
HERE ARE three major themes in this Digest: Mid-air
collisions; Spring fever and Low level hazards facing
Oh, dem sticky valves
Editor:
Editorial Assistant:
Graphic Design:
Photographs:
© Commonwealth of Australia 1988
ISSN 0045-1207
B89/20570 Cat. No. 89 0558 2
Printed by Ambassador Press Pty Ltd
51 Good Street. Granville, N.S.W. 2142,
AUSTRALIA
In addition to progressing the initiatives to improve traffic
management at Sydney arising from the recommendations of
the team which recently examined air traffic procedures at
certain North American airports, it is proposed to develop by
31 December 1989 a program for the review of airspace
management Australia-wide. The aviation industry will be
closely consulted in the development of this program and in
particular in determining those areas which need priority attention.
Al Bridges
Karen Hutchison
Lesley Boulton
P4
PS
P17
P20
P23
Bureau of Meteorology
Terry Walls
Al Bridges
BAS/
Warwick Budd
Diagrams:
Peter Garfield
Cartoon:
Gary Clarke
necessary, corrective action taken on an ongoing basis. In
addition, the Group is continuing to progress. OJ1 a fast track
basis, the major airways facilities modernisation program
which, through such initiatives as consolidation of many flight
service and some air traffic control units to major capital city
centres, offers large productivity gains for the Authority which
will be reflected in lower costs to the aviation industry.
4. Establish effective project management procedures
The successful implementation of the current capital
Investment program, including new radars for Sydney,
Brisbane and Canberra and the rectification of the problems
with the radar systems at Melbourne, Adelaide and Perth,
rests heavily on having in place effective project management
arrangements and adequate project management resources.
The Authority is seeking outside assistance to help with this
massive task and as a risk minimisation measure will, as a
general rule, be acquiring only off-the-shelf systems already
operating successfully elsewhere.
The key to achieving these objectives lies with the people who
make up the Airways Operations Group. Operational and
technical staff are being involved more effectively in the
Authority's decision-making processes, in particular In the
acquisition of new operational facilities. For Instance, we
consider the cost associated with sendi~ a 10 man multidisciplinary team overseas to look at possible options for new
radars at Sydney, Brisbane and Canberra a small price to pay
to get the decision right. The Authority is also embarking on a
major increase in its staff development and training effort with
particular emphasis on management and supervisor training
and skills broadening.
In essence, we have recognised the need to become more
people-oriented and trust this will be reflected in a high level
of service and a high level of customer satisfaction.
11~
........
PHIL BOWEN
T
In the centre section is a complete index of Airworthiness
Advisory Circulars. This very useful aid is provided not only for
LAMEs, but for owners and pilots alike.
The series of articles on mid-airs is designed to show how to
avoid disaster, and the aim is to educate us all through
lessons learned. Mid-airs are just too final for anyone to benefit
from personal experience.
In Australia, Spring is a pretty active season. The sap may
rise, right enough, but so does the cloud, and often it contains
all sorts of nasties. Any type of weather is to be expected:
Spring is a time for great care in pre-flight planning. Always
allow plenty of time for your journey and you'll find the all-toofrequent sudden change in the weather won't catch you out.
A short paragraph in the yellow pages emphasises that far too
often, alas, agricultural pilots fly into power lines. The accident
highlights an article concerned with the disciplines necessary
for successful operations close to the ground. The back-cover
poster reinforces the message: at very low level wires and turbulence are major hazards. We have just released a video on
this theme, too. It's called 'Going Ag...Grow' and can be
obtained or viewed at your nearest Field Office or major agricultural operation.
Finally, the Digest welcomes BASl's 'new look' Journal. This
fills the gap between accidents and our analysis of lessons to
be learned. The Journal gives the facts more fully than before
- number four of Autumn '89 complements this Digest with
excellent cockpit visibility diagrams on the back cover and a
very relevant article on 'The Mid-Air Crisis'.
-
the agricultural pilot.
~~
Editor
Covers
Front: Entry in previous Photographic Competition taken
by E. Mason
Back: Poster design and production by Soussanith
Nokham
�Aviation Safety Digest
Aviation Safety Digest
142
142
Northern Australia
In northern Australia there is also a general
increase in atmospheric instability as spring
progresses (see table 2).
Table 2.Average frequency of thunderdays at
various localities in late winter and spring (*
indicates less than one)
Darwin
Alice Springs
Croydon (Nth Qld)
Charleville
Bureau of Meteorology
ECENT editions of the Digest contained
_articles on flying weather in the other
seasons. Spring brings its own type
of weather, and we will briefly refer to the
changes which occur in different parts of the
country and their implications for flying.
Southern Australia
As spring progresses showers and storms tend
to replace the fog/persistent low cloud that
characterises winter in many parts of southern
Australia (see Table 1). There are a number of
reasons for this change, including:
• An overall increase in low level heating.
• The increasing incidence of a trough in the
easterly flow at Mean Sea Level along the
West Australian and eastern coasts.
• Incursions of cold air from the Southern
Ocean over southern Australia at middle and
higher levels in the troposphere.
• The prevalence of sharp upper air troughs
and southerly jet streams.
Table 1. Average frequency of thunderdays and
fog days at Canberra in late winter and spring
(*indicates less than one)
AUG
*
5
SEP
2
4
OCT
3
3
SEP
*
1
2
1
*
*
OCT
7
3
4
5
NOV
13
4
7
6
By late spring many features of t he 'wet'
season are usually evident in northern Australia and these present the pilot with a far different scenario to the southern storms. The
summer 1988/89 Digest provided considerable
information on 'wet' season flying, and is well
worth rereading.
Spring
the
season of
change
Thunderdays
Fog days
AUG
*
*
NOV
5
1
The freezing level is usually quite low in
springtime cold outbreaks and aircraft icing
then becomes a very serious problem. The winter 1988 and winter 1989 Digests contained
articles providing valuable information on
airframe and engine icing.
Behind all the events that led to the final catastrophic moments, is the fact that the pilot was
inexperienced in the ways of the North's wet
season and the particular hazard it presents
over featureless areas with great distances
between emergency landing places. It is vital
for all pilots to realise that weather conditions
encountered in the North's wet season, particularly in the late afternoon, are a very different
proposition to the storm-type weather normally
encountered in southern Australia, and diversion action usually involves long flights over
country where map reading is most difficult.
- Extract from Aviation Safety Digest No 55.
A special type of cloud worthy of mention
occurs on some spring mornings in the vicinity
of the southern Gulf of Carpentaria - this is
'the morning glory' cloud phenomenon and is
ma nifest as a mobile low level roll cloud. (A
photograph of the morning glory is on the cover
of Digest No 123). Turbulence typical of that
associated with any 'rolling' cloud is present
a nd pilots are advised to give it a wide berth.
Overview
Pilots must particularly heed the latest forecasts and warnings in spring because:
• The h eavy s howers and storms often contain
many of the h azards of hail, downdrafts, gust
fronts, microbursts and reduced visibility.
• The weather typically changes very quickly.
• Discontinuities (eg upper air troughs) are
us ually sharp.
To complement the forecasts, pilots are advised
to look for the visual clues that often indicate
the rapidly changing condit ions, a nd exercise
all the skills of weatherwise flying (which will
be the subj ect of an article in a later Digest) D
Wire survival
by John Freeman, Examiner of Airmen, Civil Aviation
Authority
The brutal fact is that, with a possible career
spanning 20 years and thousands of wirestrewn paddocks to be treated, unless the basics
are followed the ag. pilot is going to be pretty
lucky to survive.
There are many ag. pilots who have grown up
in the current situation where coping with
wires is a many times a day occurrence. They
do this day after day from the time that they
go out into the world with their new rating, and
they don't hit wires . They are doing something
right. The only way to join them is to remember
the basic rules 1. Carry out the WISHST ANDE check (see
HE DEATH of a young agricultural pilot the
other day prompts me to w rite this article.
This young man had a promising career
ahead of him in agricultural aviation . I flight
tested him in May 1987 for issue of his agricultural pilot rating and found him to be at a good
standard; an above average pilot, careful,
metic.ulous and mindful of his training.
He hit a wire during a clean-up run. The wir e
was hard to see with a long span between
poles. However, the pole run was quite obvious.
Where did he go wrong and what could have
prevented the accident?
Agricultural flying training sequences now
carry great emphasis on wire location and
avoidance. Budding ag. pilots are shown how
easy it is to use clues to the wire runs so that
they may locate the wires themselves. They
also have hammered into them the requirement
for an extra 'hazard check' to be fully comp leted before carrying out those potentially
dangerous clean-up runs. The current issue of
the Agricultural Pilots Manual has been
updated by me to include a very la rge segment
on wires, their locat ion and avoidance. In that
publication it is said that if the Air Force can
carry out an extra 'check wheels' check on final
approach to avoid wheels up landings, so surely
agricultural pilots should likewise carry out the
extra 'h azard check' prior to carrying out
clean-up runs.
Its all a matter of professionalism. Even so,
how does it happen t hat a young, recently
trained pilot hits a wire, particularly in a
clean-up run?
Well, for starters, this is not the first t ime, and
personally I'm tired of seeing fellows, with
whom I have flown and come to like, disapp ear
in a pall of smoke!
When the pilot is going through h is agricultural
fl ying training he is taught the bas ics of survival in agricultur al flying, just as a child is
taught how to cross the road. If the pilot takes
notice of those basics, proper wire location,
extra hazard checks etc, only until he feels that
he has set up his own approach to the problem
then ceases to 'think', he is as long for this
world as the child who forgets to look to the
right, to the left and to the right again, before
crossing the road.
below) before commencing the treatment.
2. Locate all wires within the treatment and
manoeuvering areas.
3. Leave ground-borne distractions on the
ground and concentrate only on the job being
carried out.
And your final life insurance.
4. Carry out an extra 'hazard check' before
clean up runs.
There's nothing quite as delightful as an old
ag. pilot, and nothing quite as sensible as a
dedicated ambition to become one.
W-
wind direction and strength
I
identification of treatment area
S
sun position
H
hazards, treatment and manoeuvring
areas
S
susceptible crops
T
terrain
A -
access for markers
N -
nuisance, people and stock
D -
direction of t reatment
E -
emergency landing areas D
�Aviation Safety Digest
Aviation Safety Digest
142
142
Physical
Mid-air!
If\ ~, ID-AIR! The media love it, all those great
, ,, human tragedy s_tories with lots of good
_
pictures of smoking holes and twisted
wreckage. But what of ourselves? We wonder
what went through the minds of those involved,
how do their loved ones feel now... how did it
happen, could it happen to me?!
Every pilot, every member of an aircraft's crew
and every Air Traffic Service Officer has a personal interest in avoiding mid-airs. Obviously
those in the aircraft may well be killed. But the
effect on those left behind, ATS, can be equally
devastating. Overseas controllers have suicided
after observing a mid-air on their screen.
Doctor Liddell, the CAA 's Aviation Medicine
Director, has written our first article on midairs. He describes in terms we can all understand the capabilities and limitations of the
human eye. The second article describes the
mid-air collision of a DC-9 and PA-28 over a
large city, a scenario which could happen in
Australia if we do not follow procedures correctly and fail to apply common sense to our
aviation. The third article then describes two
Australian mid-airs and summarises the
lessons from each of these articles.
Physical relates to the properties of the other
traffic (the target) and the physical environment surrounding the target.
The most obvious factor is size. A 7 4 7 viewed
from 100 metres cannot escape attention. However, the same aircraft at eight km will not be
so obvious. Yet at jet aircraft closing speeds of
1000 knots or one mile in four seconds the
observer has only 20 seconds to see the other
aircraft, decide that there could be a conflict
and take avoiding action. In light aircraft with
closing speeds of 200 knots (one mile in 15 seconds) there is more time available to see
another aircraft; however, the target size is
much smaller especially if the aircraft are
approaching head on. (Refer to Figure 1).
The contrast with the surrounding environment
will have a marked affect upon visibility. The
white contrails from jet engines seen against a
blue sky are highly visible. However, set
against a backdrop of white overcast the
contrails virtually disappear. Equally, trying to
sight another aircraft below the horizon can be
extremely difficult as it becomes lost in t he
background of earth colours or the shapes and
confusion of suburbia . Combat pilots are
trained to realise the importance of the s~m;
targets between the observer and the sun are
virtually invisible because of the extreme contrast caused by the sun's brightness. Pilots
must appreciate that their aircraft is invisible
to any traffic 'down sun' from their position.
3 SECONDS TO IMPACT - ,11
11
11
fl
r:
,,
1I
JI
n
11
11
11
l..J
11
11
'I
1.5 SECONDS TO IMPACT __ )j
I I
I I
I I
Well clear, near miss or
mid-air!
Understanding Seeing! Dr Robert Liddell,
Director of Aviation Medicine, Civil Aviation Authority
A week rarely goes by w ithout an article in the
press about a near miss between two aircraft
somewhere in Australia. All too frequently
there is a mid-air collision with its almost inevitable destruction of aircraft and loss of life. As
a pilot, understanding the act of seeing will
increase your chances of remaining clear of
other traffic.
The act of seeing can readily be broken down
into three distinct areas; physical, physiological
and psychological.
I I
i'
I I
I
:
;-..1
0.4 SECOND TO IMPACT
'\I/
:
I
-------~~~~~~-·~~/w
-0
===-o~
=O
CLOSING SPEED 1000 KNOTS
THE RETINAL SIZE OF THE COLLIDING
AIRCRAFT REMAINS RELATIVELY SMALL
UNTIL VERY SHORTLY BEFORE IMPACT
FIG.1
-----------~~
--------~
')....
------
AIRCRAFT B
p.1l-1G - - - - -
\j\;.e;~---
p.(;.~--
~ --
!!- --
pilots. This should be considered the worst case
and if by wearing glasses or contact lenses an
individual can improve the visual acuity to normal (6/ 6) or better t hen that should be done.
The difference in visual ability between 6/ 6 and
6/ 12 could mean the difference between seeing
an aircraft in t ime to take avoiding action or a
'mid-air'!
The technique to overcome this effect is to
make a conscious effort to push the point of
focus out to infinity by focusing on points away
from the aircraft such as the ground, the wing
tips, distant clouds or star s. This refocusing
must be done repeatedly as over a few minutes
of looking at empty space the point of focus
will move in again .
IF TWO AIRCRAFT ARE GOING TO COLLIDE. EACH
MAINTAINS A CONSTAN T RELATIVE BEARING TO THE OTHER
..{"'- AIRCRAFT A
FIG.2
The greatest enhancement to contrast exists
w ith the flashing strobe light. This light ma kes
use of two mechanisms to attract a ttent ion. The
first is the contrast of t he light's colour against
the background. The second relates to the
apparent movement of the light as its brilliance
expands and contracts with each flash.
Movement is the most important physical property in the visibility of targets. Objects which
move acr oss the visual field stimulate more
nerve endings in the eye and are noticed soon er.
The unfortunate aspect of this is that a target
which moves relative to the observer is not generally a collision risk. If two aircraft flying on a
constant heading and at constant speed are
going to collide, they will ma intain a constant
relative bearing to one another and appear to
remain stationary in the windscreen. Thus one
of the most important cues for visual target
acquisition (movement) is missing on the very
target which poses the greatest t hreat. Figure 2
illustrates t he constant relative bearing
situation.
Surprisingly many pilots ignore one of the
aspects of vision with the simplest solution.
There is little point searching the sky for the
small dot which threatens to become an aircraft
on collision course if the windscreen is covered
in small dots of dead insects and dirt . In
today's aviation envir onment the pilot must
take every step available to improve the possibility of seeing traffic, and pristine clean windscreens and glasses are a good place to start .
Physiological
The optics of the eye determine how clearly the
eye can focus distant objects. The standard for
normal distant vision is 6 / 6. This mean s that an
individual can see clearly the 6/ 6 line of a ch a rt
at a distance of 6 metr es. 6/ 9 or 6/ 12 vision
means that the subject sees clearly at 6 metres
what t he normal eye sees at 9 or 12 metres .
The v isual standards allow for vis ion as poor as
6/12 for private pilots and 6/ 9 for commercial
Psychological
The best vision in the world is of no value if it
is not used. The pilot who does not look out of
the cockpit will never know about t he traffic
until the sound of impact.
Seeing involves looking and looking involves
expectation; the expectation of finding a target.
If you think you are the only aircraft in your
airspace, then you will not see the other traffic.
Finally, ask yourself how can you help to make
yourself more visible to your fellow p ilots.
Be awar e of your position in relation to the
sun, radio your position and intention to all
t raffic in uncontrolled areas, slow dow n and
use strobes, beacons and lights in areas of high
traffic density; and keep a good lookout.
The technique used for searching the skies for
traffic is important. The optics of the eye are
s uch that to see a small target such as a distant
aircraft the eye must be looking straigh t at the
t arget. This is especially importa nt if the target
is not moving relat ive to t he observer i.e. on a
collision course. To achieve this the eye must
scan each area of t he sky in a systematic
fashion so that all quadrants are covered.
Nothing will be gained by sweeping the gaze
rapidly across the areas of search, as the eye
only sees when it is stationar y. When t he eye is
moving from one point of fixation to the next it
is functionally blind. The technique then is to
divide the sky into quadrants and move the
gaze across the quadrants stopping every few
degrees of eye travel for a moment to sear ch
tha t area for traffic.
Myopia is a term used to describe shortsightedness. Empty field myopia is what happens to all individuals w hen looking out of a
cockpit at the empty sky . As there is nothing at
infinity on which to focus, the eyes focus at a
point 1-2 metres away. This is made worse by
the effect of window frames and posts a s t hey
tend to cont ribute to dragging the focusing
point in from infinity. The effect of this is that
w hils t searching the empty sky the eye may be
focused on a point 1-2 metres outside the aircraft w ith the result that a target a t a distance
will at best be blurred and probably invisible 0
�Aviation Safety Digest
142
• Aviation Safety Digest
• 142
Mid-air collision over
Cerritos
At about 1140 am a PA-28 departed Torrance,
just south of Los Angeles International Airport
(LAX), on a VFR flight to Big Bear, about 60
miles to the east and at about 6,000 feet up in
the mountains. At 1120 an Aeromexico DC-9
had departed Tijuana for LAX. These aircraft
collided over Cerritos, a suburban city of Los
Angeles, at about 1152, both aircraft falling to
the ground. The three occupants of the PA-28
were killed in the collision; 58 passengers and
six crew in the DC-9 were killed by ground
impact forces and 15 people on the ground were
killed.
The NTSB determined that the probable cause
of the accident was the limitations of the ATC
control system to provide collision protection.
Factors contributing were the inadvertent and
unauthorized entry of the PA-28 into the Los
Angeles Terminal Control Area (TCA) and the
limitations of the see and avoid concept to
ensure traffic separation.
The PA-28 route was planned to keep it well
south and east of LAX climbing to 9,500 feet.
The PA-28 pilot did not activate his flight plan,
nor was he required to. The transponder was
set correctly to the VFR code and does not give
height information. The pilot, flying from the
left seat, was familiar with the area. He had
two passengers , one seated in the front right seat.
The DC-9 was on an IFR plan and was cleared
to approach from the south at 7,000 feet. The
aircraft was then cleared by approach control's
arrival radar controller to reduce to 190 knots
and descend to 6,000 feet. Just over one minute
later the two aircraft collided at about 6,500
feet. Both pilots of the DC-9 were familiar with
the area and the captain was very experienced.
At the time of the accident the controller considered his workload to be 'light'. He had
responsibility for several aircraft and was also
checking two different scopes for conflicting
traffic for two flights and taking a change of
details for the DC-9 from the arrival
co-ordinator. A traffic conflict also demanded
his attention when a Grumman Tiger requested
a clearance. The controller informed the pilot
he was in the middle of the TCA and suggested
that 'in the future you look at your TCA chart.
You just had an aircraft pass off your left
above you at 5,000 feet and we run a lot of jets
through there right at thirty five hundred'. He
then noticed the radar no longer tracking the
DC-9 and could not establish radio contact.
Weather at the time was clear with visibility of
14 miles and no cloud. The sun was high in the
sky behind the DC-9 and about the two o'clock
position on the PA-28.
The radar recording, the DC-9 Flight Data
Recorder and the PA-28 altimeter witness
marks from the mid-air impact, all indicated the
collision occurred as the DC-9 was descending
through 6,560 feet. It was tracking north west
and the PA-28 was tracking east, crossing the
DC-9 track from left to right. The collision damage on the DC-9 was confined to the vertical
and horizontal stabiliser, the horizontal stabilizer separating from the DC-9.
The engine of the PA-28 struck the left side of
the DC-9's vertical stabilizer. The left horizontal
stabilizer sheared the roof off the PA-28 cabin,
the damage indicating the PA-28 was in an
almost wings level attitude at impact. Figure 3
shows the relative positions on impact.
The arrival radar controller stated that the
PA-28 ' ... was not displayed. It is my belief that
he was not on my radar scope'. He testified
that, with regard to TCA intrusions, the number
varied and 'it could be anywhere from zero to
10 or 15 a shift that I will observe'.
Seven months after the accident a DC-9
reported, as it was happening, a near miss with
a Cessna under similar circumstances. The controller re-checked his radar display which did
not depict the Cessna. He had another controller confirm the Cessna was not depicted.
Despite the absence of a return on the smaller
aircraft in each incident, when the radar
recording was played back both the PA-28 and
Cessna were depicted. Numerous tests were
conducted in an attempt to resolve this
anomaly. A satisfactory solution was not
reached.
A visibility study was conducted to determine
the physical limitations to visibility from each
of the pilot seats. The time histories of both aircraft flight paths and attitudes were combined
with binocular photographs of the cockpits. The
binocular photographs are taken by a camera
with two lenses, the spacing between the lenses
being equal to the average distance between
human eyes. The viewing angles for each aircraft were then calculated and plotted at five
second intervals in relation to the design eye
reference (DER) points for each windshield
(Figure 4).
The study showed that for about the last 90
seconds of controlled flight, the PA-28 was
about 15 to 30 degrees left of the DER point on
the captain's windshield and the first officer's
windshield. This meant that the P A-28 was primarily in an area where the captain could see it
with both eyes. From the first officer position,
the PA-28 was in the DC-9 centre windshield
and in an area, for about 50% of the time,
where he could see it with both eyes.
~~----~~--~~;;
CAPTAIN'S
CO-PILOT'S
WINDSHIELD
WINDSHIELD
._.;
LEFT SIDE
WINDOW
DC9 CAPTAIN POSITION
MONOCULAR
OBSCURATION
SIDE
CAPTAIN'S
WINDOW WINDSHIELD
CO-PILOTS
WINDSHIELD
DC9 CO-PILOT POSITION
RIGHT SIDE
PA28 CO-PILOT POSITION WINDOW
LEFT SIDE
WINDOW
FIG.4
PA28 CAPTAIN POSITION
For the PA-28 pilot, the DC-9 was about 50
degrees to the right of the DER point and could
only be seen by him on the far right side of the
co-pilot windshield. From the front, right seat
of the PA-28, the DC-9 was about 55 degrees
right of the DER point and would have
appeared at the left edge of the right side window.
TIME 10 COLLISION (SECONDS)
5
l~
10
15
20
25
30
35 40
45
50
1.
0.
~
:z:
0
;::
u;
o.e
(.)
0.5
<
0.4
s
0
<
_,
=>
5 0 .3
(/)
u.
0
>- 0.2
~
co
;a
0
a:
a..
0.1
o.o
o.o
FIG.5
0.5
1.0
1.5
2.0
RANGE (NM)
2.5
3.0
3.5
4.0
Previous studies by the Massachusetts Institute
of Technology had been conducted to determine
target acquisition parameters for pilots. Sixty
four tests were conducted with pilots who did
not know the test objectives. Intercepting aircraft were flown head-on, at 90 degrees and
135 degrees, predominantly from the left, and
v isual acquisition was achieved in 56%, the
median range being 0.99 miles. The greatest
acquisition range was 2.9 miles.
A further 66 tests were conducted in a TCA
with the pilots aware of the test objectives. Visual acquisition was obtained in 86% and the
median range was 1.4 miles.
Using these tests and pertinent data from the
Cerritos mid-air, Figure 5 was constructed.
These graphs do not allow for limitations such
as cockpit structure or the monocular regions.
The NTSB probability of visual acquisition
graphs indicate the PA-28 pilot had an 80%
probability of seeing the DC-9 15 seconds
before the collision and the DC-9 pilots a 30%
probability. These graphs attempt to allow for
aircraft size, relative positions, closure rates
and other factors.
Regardless of this, however, both aircraft were
operating in visual flight conditions and were
required by FAA regulations to see and avoid
each other, even though the DC-9 was under
radar control in a TCA on an IFR flight plan.
The failure to see and avoid must be considered
in relation to the limitations of angles of closure, target sizes, conspicuity of targets and the
physiological capabilities of the eye.
Of particular interest, the probability of acquisition graphs indicate that had the controller
seen the PA-28 and been able to provide altitude information as well as range and bearing
to the DC-9, the DC-9 crew's probability of
acquisition would have risen from 30% to 95% .
In any case, some avoiding action would have
been initiated.
The major NTSB findings were that:
• Both pilots were required to see and avoid.
There is no evid ence that either pilot
attempted an evasion.
• The PA-28 pilot was not cleared to enter the
TCA but his entry was inadvertent.
• Both aircraft were displayed on the arrival
controller's radar but that the PA-28 primary
target may not have been displayed or displayed weakly.
• The arrival controller did not see the PA-28
radar return.
• The Los Angeles area was not equipped with
an automated conflict alert system. (Board
tests had indicated that such a system would
have alerted the controller.)
The NTSB probable cause was the limitations of
the ATC system to provide collision protection.
Contributing factors were the inadvertent and
unauthorized entry of the PA-28 into the TCA
and the limitations of the see and avoid
concept. D
�Aviation Safety Digest
142
Could it happen to me?
Over a 10 year period, the Bureau of Air Safety
Investigation has r ecorded over 1,000 breakdown in separation occurrences. Of these, over
600 were in controlled airspace. For the 10
years to 1989, BASI recorded 22 mid-air accidents. Five of these involved General Aviation
aircraft operating in or near aerodromes and
not engaged in display t ype flying.
Near the busier aerodromes, particularly when
constricted by lane of entry requirements, the
need for lookout is paramount. The following
example illustrates the dangers.
A Beech 50 was cleared through the Melbourne
control zone at 2000 feet to Moorabbin. After
leaving controlled airspace, the aircraft probably descended to 1500 feet before calling
Moorabbin tower.
A Bell 47 helicopter was tracking from Keilor,
abeam Essendon, to Moorabbin at 1500 feet.
Although initially well a head of the Beech
which was cruising at about 150 knots, the helicopter was cruising at only 60 knots. In
addition, the probable tracks of both aircraft
were closely paralle l w ith the helicopter crossing the Beech track at two points.
Before either aircraft called Moora bbin Tower
but after both pilots had set the Tower frequency, the aircraft collided. All five people
were killed in the acciden t .
A weak cold front had passed through the area
about 30 minutes before the accident. As a
result, the cloud base was about 2500 feet with
lower patches . Visibility was in excess of eight
kilometres. The accident happened at about
2. l 7pm. Both anti-collision beacons on the helicopter were working a nd the upper beacon and
probably the lower beacon on the Beech were
working at the time of the collision.
Initial contact was between the Beech's right
propeller and the helicopter's main rotor. The
right w ing of the Beech was between the
helicopter 's main rotor blades and the transmission gear box. The wing was then severed
when it impacted the rotor mast. Finally, the
rotor severed the tip of the Beech's fin. The
helicopter lost a rotor stabiliser tube and
weight and the outboard section of one rotor
blade, as well as sustaining other substantial
damage in the collision.
It was concluded that the flight paths of the
two aircraft were converging at about 40
degrees, w ith the helicopter ahead and to the
right of the Beech. Together w ith the relative
speeds, this w ould result in the a ircraft
approaching each other along a constant line of
bearing of a bout 20 degrees to the right of the
Beech a nd 120 degrees to the left of the
helicopter.
It was estimated that the pilot of the Beech
would not have been able to see the helicopter
until under six kilometres in ideal conditions .
The conditions were considerably below ideal.
The maximum distance at which a standard
anti-collision light can be seen under these conditions is less than two kilometres.
It was determined that the collision occurred
outside controlled airspace w hile both aircraft
were operating VFR. The probable cause was
that the pilot of the overtaking aircraft, the
Beech 50, did not s ee and avoid t he helicopter.
Within the circuit area also demands a good
lookout. Jandakot, Archerfield, Bankstown and
Parafield as well as Moorabbin have all had
their share of mid-airs . A Parafield accident
illus trates how easily a mid-air can occur in the
circuit.
A Cessna l 72M was returning from the training
area and extended the base leg, probably to get
spacing on the preceding aircraft. A Piper
PA-28 w as conducting circuits at the same time.
The aircraft collided at about 250 feet altitude
on finals , all five persons being killed .
At the time of the accident (12.16pm), visibility
was good, although there was 7 /8 of cloud at
3000 feet. Posit ioning of each aircraft in
relation to the other, may have meant t h at each
aircraft h ad ground features behind it which
made it less conspicuous. During its turn onto
final , the Cessna would have appeared to the
Piper's pilot in a constant posit ion in t he
Piper's right windscreen, about 40 degrees to
t he right. Unless he looked directly at it, it is
unlikely that the Piper pilot would have seen
the Cessna.
About 23 seconds before the collision, the Piper
began a 30 degree left bank turn onto finals. It
w ould then have been impossible for t he Piper
pilot to see the Cessna. About 10 seconds before
the collision , the Piper commenced to roll out
on final and the Cessna should have been
theoretically visible to the Piper pilot. The
Piper was then overtaking by at least eight
knots from above and to the left. However, as
no avoiding action was taken, it is assumed that
the Cessna was too low for t he Piper pilot t o
see it. The Cessna pilot would have had
extreme difficulty in seeing the Piper.
The aircraft collided while the Piper was overtaking and above the Cessna. The Piper's propeller cut t hrough the Cessna's cabin roof and
the right flap scraped down t he leading edge of
the Cessn a's fin . The Piper locked together wit h
the Cessna, positioned with its nosewheel
against the Cessna's left inboard flap, right
w ing root on the Cessn a's tail cone and forward
of the t ail and the right wheel on the right side
of t he Cessna's fuselage. The aircraft fell to t he
ground locked together.
The investigation was unable to determine if
the anti-collision beacons on both aircraft were
operating normally. Due to impact damage, it
was also impossible to determine without doubt
the radio frequencies set and the volume control position of the VHF radios. However, no
evidence was found of any defect or
malfunction in either a ircraft which might have
contributed to the collision.
The Tower Controller observed the two aircraft
turning base, but the substantial longitudinal
separation would have appeared to the controller to have been more than adequate. On finals,
he instructed the PA-28 to go around on three
occasions, 14 seconds, 7 seconds and 2 seconds
before the collision. His first transmission was
partially over transmitted by another aircraft.
As no action was t aken by the PA-28 pilot and
a s t he runway appeared clear , it is probable
that this pilot did not hear or did not appr eciate the urgen cy of t he situation.
Due to a combination of the wind on final and
the extended base leg, the Cessna took just over
three minutes to fly from the point where the
pilot reported base to the collision point. The
PA-28 took just under two minutes to fly from
its base point to the collision point. The Piper
p ilot would, therefore, probably not have considered the Cessna to be a traffic hazard. The
pilot of the Cessna would probably have not
been aware of the Piper. Both pilots posit ioned
t hemselves to give adequate spacing on the preceding aircraft, another PA-28.
The chain of events leading to this accident
commenced w hen the Piper turned onto base
ins ide the Cessna, each pilot apparently posit ioning himself behind the preceding PA-28.
The accident could have been averted if either
of the pilots had adequately scanned the airspace to t he left and r ight of their aircraft. The
base leg is a principal area of the circuit w here
pilots must position their aircraft relative to
one another; it is also the area wher e aircraft
are at a considerable distance from the
controller.
The cause of the accident w as that, whilst operating in those areas of the circuit pattern where
confliction could have been detected , neit her
pilot exercised the degree of vigilance necessary
for the avoidance of the collision.
It is the mid-air that brings down a big jet
which really catches media attention. In 1978
144 people died when a DC-9 and Cessna 172
collided in the circuit at San Diego. The BASI
Journal number 4 describes a near-miss incident over Sydney between a Boein g 7 4 7 and a
Piper PA-28. The Journal also describes the
collision between two Cherokees over Moreton
Bay, an area where ev ery pilot should be awar e
of possible traffic and on the lookout.
Most of us fly the little aircraft and it is in
these that we are most likely to encounter a
mid-air . Why? There are more of them, they are
found just anywhere and their pilots are often
overworked and underexperienced (reJ11ember
what it was like when you were a student?).
Studies indicate that most near misses and midairs involved overtaking aircraft and only a
minority from head on. Most also occur near
aerodromes and below 3000 feet.
Doctor Liddell discussed physical, physiological
and psychological considerations when using
the eye for lookout. He described how to make
y ourself more conspicuous - aircraft size, the
use of radios and the use of lights, particularly
strobe lights . He warned of the lack of relative
motion with the aircraft y ou are about to hit
and su ggested the best form of attack is a pristine clean window. He suggested that to find
and see a distant target we need to focus our
eyes on a distant object first. And, finally, he
made t he most important point - all this is
lost if you do not look outside .
The Cerritos accident demonstrates the possible
limitations of the radar system and its operators. It is possible, for various reasons, that
the controller may not see a target on the scope
or may, consciously or subconsciously, ignore
the target. The introduction of mandatory use
of mode C to give alt it ude readouts to the controller will certainly help in Australia. Outside
controlled airspace, it certainly helps to make
you more conspicuous if you go full reporting.
These accidents not on ly show the limitations
of radar but also the limitations of the eye.
Lookout and good scan technique are the only
real answers. Keep vigilant in ar eas where you
least expect other traffic; that is, in controlled
airspace and the back of beyond. Back t his vigilance up with a sound knowledge of where you
are in relation t o likely busy spots - small airfields, glider areas, hang glider jump-off spots
- and listen for other traffic on the radio.
Pilot lookout is the only present method available to over come the shortcomings of r adar. A
pilot operating in the Bankstown area on a Sunday will have all available eyes outside. Will
the same pilot be as vigilant 10 miles away on
approach into Sydney or 1000 miles away
approaching Ceduna? Studies hav e shown that
you are much more likely to see traffic if y ou
are expecting t r a ffic and are looking out. If you
are not really expecting to see another a ircraft
and are just 'gazing into space' you will not see
the traffic. Each of these accidents show that
mid-airs do occur with the sun high in t he sky
and the weather fine and beaut.
The only good that comes out of horrific accidents like these is the lessons learned t o prevent a r ecurrence. Apply the lessons to you rself
and stay a ler t, aware and alive D
�Aviation Safety Digest
If you are not eligible for a free issue, or if you would like addit ional copies of the Digest:-
142
Cessna 21 OE, 14 May 1988
Accident
response
Cessna TU206-A, 18 February 1988
After 207 minutes of flight with a calculated
endurance of 300 minutes, the engine began to
surge and stopped. Emergency procedures,
including auxiliary fuel pump on 'LO' with
short periods of 'HI', failed to remedy the situation. A successful forced landing was
executed, although the aircraft received substantial damage in a ditch. The left wing fuel
tank had partially collapsed, reducing the
amount of fuel but still indicating full fuel.
BAS! recommendation
The instrument panel placard should clearly
indicate that the auxiliary fuel pump should be
set to 'HI' as the first action following fuel flow
fluctuations.
CAA action
The CAA does not agree with the recommendation. The various configurations of the auxiliary fuel pump control on the Cessna 200 series
can only adequately be covered by good system
knowledge. In all cases, the potential for a second failure only seconds after power recovery
is very high.
Cessna A 188-A1, 1O May 1988
On the second day, the pilot completed spraying
area two. During the clean-up run, the aircraft
struck a power line. The pilot's attention had
been on avoiding accidentally s praying a
near-by crop.
BAS! recommendation
The CAA should continue to publish warnings
on power lines and the importance of aerial
inspections.
CAA action
This Digest contains another article on power
line hazards as well as a poster. The video
'Going Ag ... grow' has recently been released .
The engine failed in the cruise following detachment of the oil filter adapter. The right gear
collapsed on touch down as the pilot could not
fully pump the gear down because the emergency gear extension handle had inadvertently
been moved slightly inward.
D
BAS! recommendation
The CAA should alert maintenance organisations to the dangers of thread failure if proper
torquing is not carried out. Information on the
use of emergency gear extension handles in
Cessna 210 aircraft should be publicised.
CAA action
Due to the magnitude of this problem, an
Airworthiness Directive is being prepared. Full
details on the use of the emergency gear extension system are published in the Owners
Manual.
(including surface postage)
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BAS! recommendations
The CAA should re-emphasise the need wherever possible to operate at heights which provide increased safety margins. The CAA should
also review this type of failure to determine if
a special service life is j ustified.
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Hughes 269C, 26 May 1988
While in the cruise at 100 feet AGL, the belt
drive clutch control tension spring assembly
failed, resulting in loss of power. The helicopter
hit a tree during the autorotation and rolled
onto its side.
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pilot behaviour by positive reinforcement of
sound techniques. It will examine all aspects of
piloting and publish formal results as well as
'the tricks of the trade'. The 'crash comic' will
become a 'how not to crash ' comic.
or over thirty years, the Aviation Safety
Digest has been an integ ral part of
Austral ian aviation .
In July 1986, responsibility for the Digest was
transferred from the Bureau of Air Safety
Investigation to the Flight Standards Division of
the then Australian Department of Aviation
(now CAA). This move reflected the perception
that civil aviation may have reached the limit of
accident prevention through regulation and
that the way forward is through increased
emphasis on safety education in general, and
the 'human factor' in particular. Rather than
just draw lessons from accident investigations,
the Digest will increasingly seek to influence
•
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Anyone with an interest in aviation will benefit
from tapping into this unique source of the
accumulated wisdom of the profession and
the latest research into aviation safety in
Australia. Indeed, anyone with an interest in
high technology and the roles and lim itations
of the human operator wi ll find th is publ ication en lighten ing .
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CAA action
An article will be prepared for the ASD on this
topic. It is considered that the schedule of cable
inspections - 50 and 400 hours - is adequate.
Cable failure history indicates only one failure
in 32,000 hours.
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Hughes 269C, 26 June 1988
While mustering cattle, t he number one connecting rod failed and penetrated the engine crankcase. An autorotat ion was carried out onto
unsuitable terrain and the helicopter rolled
over.
BAS! recommendation
The CAA should consider replacement of connecting rods at overhaul or reduce the time
between engine overhauls for helicopters used
in the mustering or similar roles.
CAA action
The accident was caused by the failure of a
connecting rod bolt. These bolts are subject to
the requirements of AD/ LYC37 amendment 6.
As the defect r eport indicates that the standard
and ext ent of maintenance at overhaul may
have contributed to this failure, no action as
recommended is justified.
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Feeling a little query?
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The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others .
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Write to: AIRFLOW
Aviation Safety Digest
G.P.O. Box 367
CANBERRA A.C.T. 2601
Australia
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Aviation Safety Digest 142 / i
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ii/ Aviation Safety Digest 142
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The Civil Aviation Authority, Continuing
Airworthiness Section receives many enquiries
about airworthiness subjects. Many of the questions have been previously discussed in the
1 OOO or so articles distributed by the Authority
since the introduction of the Airworthiness
Advisory Circulars (AAC) in September 1966.
The AACs were introduced as a vehicle to pass
on items of general interest on airworthiness
subjects. Many of these articles give helpful
guida nce on airworthiness matters, whilst
others draw attention to potential technical
problems .
The main purpose of these articles is to inform
people interested in aviation related matters of
the latest airworthiness trends and keep them
aware of recommended but not mandatory
items.
To assist those who may be interested in the
information contained in the published AACs,
the ar ticles and their identification numbers are
listed below. Should anyone wish to receive a
copy of an article, they should first approach
th e Air worthiness Office at the major airports
in each State Capital City or contact the Authority by telephone, facsimile or letter addressed
to:
Manager
Cont inuing Airworthiness
Civil Aviation Authority
GPO Box 367
CANBERRA ACT 2601
Attent ion: Documentation
Teleph one: (062)68 4073 Facsimile:
(062)57 4228
AIRCRAFT
Aerospatiale AS 350 and AS 355 (Squirrel and
Twinstar) - inspection of fuselage to tailboom
attachment frame for cracks
172-2
AESL (Victa) Airtourer brake lines
111 -6
Agricultural aircraft - deflector cables
192-5
Aircraft designations
22-3
Aileron interconnect strut failure
167-5
Auster aircraft accident survival
6-3
Beechcraft fuselage honeycomb panels
163-1
Beagle Pup B1 21 flyi ng cont rols
58-1
Beechcraft wing fatigue - The danger of
complacency
124-1
Beech 23 flexible push/pull controls - rigging and
replacement
35-4
Beech A23-24, A24, A24R Musketeer governor
drive failure
46-3
Beech 33, 35, 36, 55, 56, 58, 60, 65, 70, 80, 88, 95 inspection for non-ferrous engine mount nuts
43-3
Beech 35 MLG - Murphy is alive and well
104-1
Beech A36 and 55 - Cabin Door Failure
204-3
Beech Baron fuel cell inspection
121-4
Beech 65 fire hazard
54-3
Beech 76 nose landing gear door hinges
189-2
Beech 90 Air Intake Duct
202-4
Beech 200 airconditioning condenser failure
149-1
Bell 47 engine cooling fan and belts - maintenance 33-1
Bell 47 bearing replacement
201-2
Bell 47G Series - fuel shut off valve
11 2-10
Bell 206A collective control cover
41-5
Bell 212 winch hook malfunction CAA Report
131-5
Brackett Induction Air Filters
168-3
Callair A9 wing inspection
57-5
Cattle Mustering Aircraft - inspection
requirements
135-1
Cessna aeroplanes - use of MOGAS
191-2
Cessna aileron hinge pins - retaining pins
144-5
Cessna Aircraft Replacement Parts
172-1
Cessna Fuel System Contamination
202-1
Cessna Singles - down stop bumper
155-2
Cessna 100 Series - fuel line
109-7
Cessna 150 instrument system
103-5
Cessna 150 upper body restraint
91-3
Cessna 150, 170, 177, 180, 205, 206, 207, 210 flap
actuator maintenance
47-1
Cessna 150 and 152 rudder pedal bar
116-3
Cessna 172 RG U/C hyd downline chafe
128-4
Cessna 172 throttle arm ineffective clamping
58-2
Cessna 172 incorrect fitment of MLG downstop
bumper pads
172-4
Cessna 172K metal fuel tanks
121-4
Cessna 177 fuel shut off valve control
56-2
Cessna 182 cowling care
29-3, 41-2
Cessna 182 incorrect fitment of MLG downstop
bumper pads
172-4
Cessna 182, A 182 rudder pedal link rod pins
31-7
Cessna 182J fuel vent losses
121-4
Cessna 185 throttle control
81-5
Cessna A 185 induction airbox shaft assembly
117-4
Cessna A 188 pilot seat adjustment
112-9
Cessna TP206, TU206, 210 alternate air door
modification
32-3
121-4
Cessna U206 fuel line chafe
Cessna 200 Series exhaust mufflers (non turbocharged engines)
101-4
Cessna 205, 206, 207, 210, fuel flow stabilisation
placard
113-6
Cessna 206, 207 and 210 - induction airbox
improvement
168-6
Cessna 207 - smoke in cabin and jammed throttle
control cable in flight
115-4
Cessna Model 210 horizontal stabilizer rear spar
cracks
159-2
Cessna 210 st abilizer spar cracks
146-4
Cessna 300/400 Series nose gear ring pack support 126-7
Cessna 300/400 Series combustion heaters
41 -6
Cessna 310, 320, 340, 401, 411 , 414, 421 landing
gear retraction and extension systems
85-1
Cessna 310/400 landing gear torque link shaft
failures
31-6, 160-5
Cessna 337 aileron pulley bracket cracking
164-3
Cessna 337, PA28 electric trim system wiring
17-5
Cessna 400 Series wing spar crack
164, 1
Cessna 400 Series landing gear emergency system 128-2
Cessna 400 rudder hinge protection
48-3
Cessna 400 Series engine exhaust system
1'24-2
Cessna 41 1, 411A, 421 McCauley propeller
attachment
41-3
Cessna Ag aircraft - fin wire strike protection
138-2
Cessna engine oil quick drain valve failure
103-4
Cessna fuel cap seals
121-4
Cessna instruments - security of installation
120-3
Cessna landing gear down indication failures
29-2
Cessna nose wheel forks
38-5
Cessna prop feathering hose
109-7
Cessna shoulder harnesses
183-2
Cessna twin engine aircraft landing gear indication
failures
84-2
Cessna vented fuel tank caps - mandatory
installation
11 2-8
Aviation Safety Digest 142 / iii
�Cessna wing locker fuel tank syphoning
76-2
DH82 Tiger Moth landing gear collapse
56-3
DH82 (Hot Tiger)
123-5
DHC1 Chipmunk crashworthiness
1-3
DHC2 Beaver installation of bench seats
150-2
DHC2 Beaver tailwheel spindle cracking
7-6
English production Chipmunk - Product Support 172-3
Experimental aircraft - design and construction 196-1
Flight loads
2-2
FU-24 Series Aircraft Fatigue Related Airworthiness
Directives
202-5
Gates Learjet Model 35A - main wheel outer half
bead radius cracked
167-2
General Aviation aircraft - carriage of extra
persons in standard seats
47-5
113-1
General Aviation aircraft - maintenance
19-1
General Aviation aircraft - recording TIS
38-1
General Aviation aircraft - structural failure
General Aviation aircraft - upper body
restraint
54-1, 62-1, 69-4
Grumman American AA-5 autopilot recertification 117-6
Gulfstream 500 and 600 spar cap corrosion
180-1
Gulfstream Aerocommander - landing gear
selector lever failure
154-4
Gulfstream Aerocommander 690 - hydraulic pump
drive & shaft keyways fractured
167-1
Hughes main rotor separation
126-2
Hughes 269 bogus tail booms
151-3
Hughes 269 helicopters - throttle cable assembly 126-3
Lycoming powered aerobatic aircraft
154-5
Mooney M20 landing gear electric actuator
78-2
Partenavia P68 nosegear oleo
121-4
Partenavia P68 Series fuselage frame
151-2, 159-2
cracks
Piper PA18 fuel filler cap
90-5
203-4
Piper PA-18 Kits
7-1
Piper PA22, PA24, oil cooler pipelines and seals
23-3
Piper PA23 emergency hydraulic hand pump
Piper PA23-250 engine over-speeding with air
feathering propeller
53-5
Piper PA23-250 - fuel selector levers
108-2
Piper PA23-250 magnetic compasses - excessive
deviation
98-2
Piper PA23-250 main landing gear selector handle 106-8
Piper PA23-250 Weldon fuel pumps
52-3
PA24 MLG bungees
109-7
Piper PA25 rubber fuel cells
199-1
Piper PA25 wing installation
108-4
Piper PA28-140 severe corrosion of flap ribs
173-2
Piper PA28 fuel line chafe
126-4
Piper PA28, Cessna 337 - electrical trim system
17-5
wiring
Piper PA28 - throttle shaft binding and cable
123-2
buckling
Piper PA28-140 electrical power failures 30-2
alternators
Inspection of aft wing spar attachment
fittings - PA28 and PA32 series aircraft
163-2
Piper PA28, and PA32 Series - fuel tank vent hoses 129-1
Piper PA28, PA32 fuel quantity gauges 99-3
erroneous indications
100-3
Piper PA28 fuel selector
122-7
Piper PA28 fuel filter drain valve
93-3
Piper PA28, PA32, PA34 magnetic compasses
194-2
Piper PA28 structural wing fatigue
121-4
Piper PA28-181 throttle linkage
121 -4
Piper PA28R engine oil quick drain valve
33-5
Piper PA28R landing gear
Piper PA30 asymmetric flap operation
24-4
Piper PA30 fuel selector handle
40-4
13-1
Piper PA30 landing gear indication
180-4
PA31 elevator down springs
11 6-9
Piper PA31 LG downlock hook defects
iv / Aviation Safety Digest 142
133-1, 135-5
Piper Navajo - model designation
101-5
Piper PA31 park brake
146-4
Piper PA31 stabilizer spar cracks
Piper PA32 main landing gear separation 188-3, 190-3
17-1
Piper PA32 rear seat restraint
194-2
Piper PA32 structural wing fatigue
Piper PA34-200T-radio cooling manifold fouls
elevator control
109-2
Piper PA34-200T fuel lines
121-4
Piper PA-38 - inspection of electrical cables
11 2-5
Piper Aerostar elevator trim - misrigging
148-3
Pitts control stick grip
180-3
Preparation of aircraft for painting
208-2
Rockwell Commander 114 wiring loom fouls aileron
control chain
99-6
Soloy Conversions - Hydrogen Embrittlement
206-1
of P/N NAS1305-2H Bolts
111-6
Victa Airtourer brake lines
151-1
Victa 100/115 fuel filters
19-6
Victa Airtourer fuel gauge transmitters
40-5
Victa Airtourer LG strut housing
5-3
Victa Airtourer shoulder harness
128-3
Westwind 1124 - aileron control difficulty
27-1
Wooden aircraft - policy
108-6
Wooden aircraft and wood glues
AIR NAVIGATION ORDERS
ANO Part 100.7 weight control of aircraft
94-4, 97-4
ANO Part 105 AD/GEN/39B - alternators
10-1
ANO Part 105 AD/INST/6B Cancelled (Fuel contents
and fuel flow gauge marking)
15-2
Aviation Regulatory Proposals on AME Licensing
ANO 100.90 Series
157-4
Aviation Regulatory Proposals aircraft
maintenance and approved organisations
186-4
Airworthiness assessment and acceptance of
ultralight aeroplanes under the provisions of
ANO 95.25
170-2
Airworthiness - operators compliance with
135-3
manufacturers service documents
Airworthiness Directives - revised issue
system
108-1' 183-1
179-2
Concessions - Air Navigation Orders
Cost benefit risk assessments with respect to
169-2
Airworthiness Directives
FU-24 - Fatigue Related Airworthiness Directives 202-3
117-1
Urgent ADs - the operator needs to know
176-1
Urgent Airworthiness Directives
Supply of Airworthiness Directives
184-1
143-1
203- 1
50-1
108-7
AUTO PILOTS
Auto Pilot Maintenance
190-4
Auto pilot recertification - Grumman American
AA-5
117-6
Auto pilot servos - servo disconnects and
overpower forces
67-1
EDO Aire Mitchell auto pilots - servo bridle cables 99-4
Smiths SEP-2 AP torque switches EAP 2340/109-3
BRAKES
Dunlop brake airbags
Piper PA31 park brake
Cessna 172 throttle arm ineffective clamping
Garb. throttle shaft binding - M.S. MA4 SPA
Marvel Schebler Carburettors
58-2
109-1
157-3
COCKPIT VOICE RECORDERS
Cockpit voice recorder carriage 5700kg MTOW
aircraft below
181-2, 188-2
CONTROLS
Airframe and engine system controls - security 89-4
Bell 206A collective control cover
41-5
Brittain automatic flight control systems certification documents
47-3
Cessna aileron hinge pins - retaining pins
144-5
Cessna 150 and 152 rudder pedal bar
116-3
Cessna 182, A182 rudder pedal link rod pins
31-7
Cessna 185 throttle control
81-5
Cessna flap actuator maintenance
47-1
Control cables
41-1, 61-1, 106-7, 121-3, 111-1, 191-1
Duplicate Inspection of flying controls
144-6
Engine control systems
185-1 23-2
Flexible push/pull controls - rigging and
'
replacement
35-4
Flight controls - Beagle Pup B121
58-1
Flight control system maintenance - use caution 46-5
Fouling of flight controls by radio cables
94-3
Maintenance notes - engine control systems
136-2
Rockwell Commander 114 - wiring loom fouls
aileron control chain
99-6
Throttle cable assembly - Hughes 269 helicopters 116-1
Vertical stabilizer decals
116-4
CORROSION
Another corrosion mode
177-1
Beach operation of aircraft
105-1
Beech A36 and 55 - Cabin Door Failure
204-3
Control cable corrosion
191-1
Corrosion of aircraft metals
3-1
Corrosion prevention in piston engines
175-4
Corrosion preventive measures
69-5
Corrosive properties of flame retardant solutions 156-1
Corrosion removal and treatment
176-3
Corrosion removal and treatment - observe proper
practices and techniques
173-1
Corrosion - small turbine engines
25-2
Corrosion in older G.A. ·aeroplanes
115-3
Water displacing corrosion preventatives (WDCP) 154-1
ELECTRICAL
AIR NAVIGATION REGULATIONS
Amendments to Aviation Legislation
Approval and Certification of Modifications to
Aircraft
Registration of aircraft - ANR amendment
Upper surface wing marks
CARBURETTORS
166-8
101 -5
Alternators - AD/GEN/39B
10-1
Alternators - drive coupling installation
180-2
Alternators - electrical power failure
30-2
Alternators - negative earth lead inspection
51-3
Alternators - problems in G.A. aircraft
36-1
Alternators - Prestolite, drive retaining nuts
46-4
Anti-collision lights - approved types
42-1
A new Ni Cad Problem - KOH Corrosion
103-2
Automotive batteries - use in aircraft
166-3
Avionics Equipment - Environmental Categories 203-3
Batteries - Ni Cad
65-1, 103-1
Batteries - Ni Cad ventilation systems
117-5
Batteries - SAFT 40AH Type 40976
204-5
Bendix rotate-to-start ignition switches
112-3
Brushes - starter/generator instant filming
189-1
Bussman current limiter - fire hazard
38-3
Cable terminations - a gripping problem
67-2
Calculators and other electronic devices - use in
aircraft
104-8
Care in battery maintenance
176-2
Cargo compartment lighting
52-1
Cessna 337, PA28 electrical trim system wiring
17-5
Electrical cable ties - use in aircraft
157-5
Electric Motors and Generators - maintenance 201-1
Emergency location beacons and lithium batteries 106-3
Lead acid battery maintenance
177-4
Lead acid battery problem
111-3
Mooney M20 landing gear electric actuator
78-2
Piper aircraft - aluminium cables
190-2
Piper PA28 - inspectiQl'l of electrical cables
112-5
Revere electronic weighing kit - earthing
96-5
Rockwell Commander 114 - wiring loom fouls
aileron control chain
99-6
SAFT 40AH Type 40976 Batteries
204-5
Silicone rubber adhesives/sealants - care with
use in electronics
93-5
Spark plug ANO - Cancellation
106-4
Spray lube and electrical connectors
175-1
Starter/generators - Lear Siegler
23000 Series
43-6, 46-2
Starter relays and solenoids - sticking
52-2, 186-1
Strobe light system dangers
96-1
Voltage regulator adjustment
122-10
ENGINES
Alternator drive coupling installation
180-2
Brackett air filter assemblies
126-5
Brackett induction air filters
168-3
Cessna 200 Series aircraft exhaust mufflers
(non turbo-charged engines)
101-4
Champion spin-on oil filter defects
100-4
Continental 10-360, L/TSI0-360 connecting rods 179-4
Continental 360 and 520 series engines crankshaft ultrasonic inspection
171-2
Continental crankshaft counterweights and rollers 85-2
Continental engines - crankcase inspections
157-6
Continental engine - governor oil transfer sleeve possibility of incorrect assembly
162-1
Continental and Lycoming - loss of crankshaft
main bearing retention
71-2
Continental piston engines overspeed limits
73-4
Continental supplemental data
194-1
Control systems
23-2
Corrosion prevention in piston engines
175-4
Dynamic counterweights - detuning - precautions 70-4
Early Gipsy and Cirrus engines - operation on
AVGAS 100
98-1
Engine air inlet flexible ducting
115-6
Engine exhaust gas leaks - a wing spar hazard 113-4
Engine overhaul periods
146-1
Exhaust clamps - turbocharged aircraft
140-3
Exhaust systems, turbo-charger - inspection
and operation
21-1 , 49-1
Flame outs/power loss - Allison 250 Series
123-3
Gipsy major bronze cylinder head damage
195-1
Gipsy Series engine product support
166-5
Induction system alternate air doors 78-3, 131-3, 145-2
Lycoming 10-540 rotator type inlet valve failure
89-2
Lycoming crankshaft counterweights and rollers
85-2
Lycoming engines utilising AC diaphragm fuel
pumps
190-1
Lycoming exhaust valve replacement
154-2
Lycoming - inspection after valve failure 53-1, 133-2
Lycoming and Continental - loss of crankshaft
main bearing retention
71-2
Lycoming main bearing stepped dowel failures
68-1
Lycoming piston engines overspeed and overboost
limits
80-2
Lycoming powered aerobatic aircraft
154-5
Lycoming rocker arm inspection and rework
183-3
Lycoming rocker shaft covers - PN 72242
155-4
Lycoming Service Bulletin 456A - replacement of
sintered iron oil pump impellers
164-4
Lycoming - sticking valves
192-3
Aviation Safety Digest 142 / v
�...
..
•
•
Lycoming oil pump impellers - replacement
caution
170-3
Mount brace corrosion by exhaust gases
132-2
Piper PA23, PA30 aircraft - engine overspeeding
53-5
with air feathering propeller
Piston engines - chrome plated cylinders 69-3
precautions
147-2
Piston engine air intake systems
163-3
Piston engine valve failures - debris ingestion
Piston engines - compression checks diagnostic value
71-1
Piston engines - corrosion prevention
111-5
Piston engines - cylinder failures, G.A. aircraft
91-2
Piston engines - dry chemical extinguisher hazard 115-5
Piston engines - testing after overhaul
100-2
Pratt & Whitney R985 cylinder head failures
98-5
Sand erosion in gas turbine helicopter engines
112-1
Soloy Conversions - Hydrogen Embrittlement of
P/N NAS 1305- 2H Bolts
206-1
Spark plug ANO - cancellation
106-4
Sticking starter relays and solenoids
52-2
Synthetic lubricating oils, aircraft engines
101-3
Top end inspection
72-2
Timing of Teledyne continental engines
208-1
Turbo jet engines in aircraft - ground operation 53-3
Volkswagen derivatives
198-4
Water methanol - use caution
8-5
FIRE EXPLOSION
Agricultural aviation - spontaneous explosion
hazard
69-2
Ammonium nitrate fertilizer explosive
19-2
Beech 65 fire hazard
54-3
Beech 90 Air Intake Duct
202-4
Bussman current limiter - fire hazard
38-3
Cabin material fire hazard
97-1
Cessna 300 and 400 Series - mandatory installation
of powerplant fire detection systems
135-2
Dry chemcial extinguisher hazard - piston engines 115-5
Electrostatic discharge from paper towels
132-2
Flexible hoses and fire sleeving
122-8
Fire extinguishers - portable
1-2
Fire hazard - gaseous oxygen systems
115-1
Fire in hangar - poor maintenance practices
31-3
Fire sleeving - flexible hoses
122-8
Flammable fluid lines in engine compartments fire resistance
66-3
Hoses - fire res[stance standards
94-2
Induction system drain lines - fire risk
26-1
Inspection and maintenance for fire protection
64-2
PVC tape-a new source of fire hazard
106-5
Smoke in cabin and jammed throttle control cable
in flight
115-4
Strobe light system dangers
96-1
FIRST AID KITS
53-4
FUEL
AC diaphragm fuel pumps - Lycoming Engines 190-1
Avoiding refuelling with incorrect fuel types
163-4
Additives in aviation fuel
22-1
Aircraft fuel drain Checks
128-6, 202-1
A.R.P. No 83/5 - use of Mogas in certain light
142-3
aircraft
AVGAS 100 - use in engines rated for
92-1, 96-2
AVGAS 80
AVGAS 100LL - introduction
116-8
56-2
Cessna 177 fuel shut-off valve control
Cessna 205, 206, 207, 210, fuel flow stabili sation
113-6
placard
202-1
Cessna Fuel System Contamination
132-2
Ces~;na - damaged line at door post
76-3
Cessna wing locker fuel tank syphoning
35-5
Collapsed fuel cell - use of incorrect filler cap
128-5
Copper fuel lines
Dangers of gasoline on composite
aircraft
165-1, 170-4, 175-3
Early Gipsy and Cirrus engines - operation on
AVGAS 100
98-1
Fuel contents, fuel flow gauge markings 15-2
AD/INST/6B - CANCELLED
43-1
Fuelling facilities - remote country aerodromes
169-1
Fuel Drain Valves
Fuel filter maintenance
108-3
Fuel leaks in the cabin
132-1
59-1
Fuel losses during flight
126-6
Fuel quantity indicating systems
Fuel quantity gauges - accuracy and placards 101-1
Fuel quantity system calibration - light aircraft 171-3
Fuel systems - incorrect hoses
122-6
Fuel tanks, light aircraft - water
116-2, 202-1
contamination
166-6
Incorrectly installed filter elements
90-5
Piper PA18 fuel filler cap
108-2
Piper PA23-250 fuel selector levers
52-3
Piper PA23-250 Weldon fuel pumps
Piper PA25 rubber fuel cells
199-1
122-7
Piper PA28 fuel filter drain valve
Piper PA28, PA32 fuel quantity gauge erroneous
99-3
indications
100-3
Piper PA28 fuel selector
40-4
Piper PA30 fuel selector handle
130-2
Security of fuel tank caps
31-2
Selector cocks - lockwiring
4-5
Selector valves - binding
40-1, 48-4
Synthetic rubber fuel cells
26-2
Tank caps - importance of proper sealing
19-6
Victa Airtourer fuel gauge transmitters
Water contamination of fuel systems on high-wing
Cessna aircraft
147-1, 202-1
Water drains - turbine engine fuel systems
148-1
MOGAS
110-1, 152-1, 191-2, 195-2
I
I
•
..•
Handling of electrostatic sensitive devices at
Lufthansa shops
155-1
Hazard Warning-Alocrom 1200
157-7
Hydrogen Embrittlementof P/N NAS1305-2H Bolts 206-1
Imported aircraft - initial certifications
74-1
Imported aircraft components and materials - use
of
37-1
Incorrect ground handling procedures
153-2
Industry participation in AAC
167-3
Logic and numbering systems - an introduction 119-1
Luggage compartment door locks
38-4
Mercury contamination of aircraft
90-2
Microfiche - what you should know about it
105-5
Microlon CL-100 Aircraft Formulation Approval
157-8
Night VMC operations - removal of requirement
for 20% reduction of landing distance
181-3
Organic Peroxide - a catalyst hazard
162-3
Paint Stripper Application
205-1
PNG Airworthiness address details
200-1
Placards, decals and markings
144-8
Queensland region -Airworthiness reorganization 188-1
Structural commercial materials
198-3
The Continuing Airworthiness of Geriatric Small
Aircraft
161-1
Timbers and Plywood for aeronautical use
196-4
Twenty Years On
179-1
Urgent Airworthiness Directives - the operator
needs to know
117-1
V-Belt drive systems
140-1
Warnings reprinted from RAAF sources
174-2
Water Displacing Corrosion Preventives (WDCP) 154-1
Weight control
88-1, 90-3, 94-4, 97-4
Work performed under an arrangement
164-5
HEATERS
Cessna 300, 400 series combustion heaters
Is YOUR cabin combustion heater safe?
Lubrication of cabin heater controls
41-6
131-2
47-6
HELICOPTERS
GENERAL
Administration of the Airworthiness Branch 182-1
Central Office
204-2
Airworthiness Office - Papua New Guinea
205-2
Aircraft Undercarriage Systems
Are you buying an aircraft overseas?
81-1
22-3
A/C Designations
Approval of aircraft modification having prior
166-1
foreign STC approval
Approval and Certification of Modifications to
203- 1
Aircraft
103-3, 160-3
Aircraft noise requirements
Amendments to aviation legislation
143-1
166-4
Cargo restraint
159-4
Carriage of stretcher patients in aircraft
111-2
Carbon monoxide contamination in aircraft
Calculators and other electronic devices - use in
aircraft
104-8
Changes to ANO covering design standards and
issue of C of A
123-1
Coastal environment coupled with low utilisation spells 'Hazard'
128-7
Commercial Anti-friction bearings - use in aircraft 143-7
Commercial material for aircraft structures
198-3
Component replacement
33-3, 56-4, 68-3
Cowl latches - Hartwell,, security
122-9
Depleted uranium in aircraft
150-1
Defective bolts
11 5-7
Departmental inspection of aircraft
197-4
Fuselage drains
143-2
Glove compartments, map cases etc. retain objects
safely
111-4
..
Bell 47 bearing replacement
201-2
Bell 47 engine cooling fan and belts - maintenance 33-1
Bell 47 freewheel slippage
121-2
Bell 47 - incorrect engine installation
117-2
Bell 47 t ransmission shock loading
2-5
Bell 47G Series - fuel shut-off valve
112-10
Bell 206A collective control cover
41-5
Bell Model 206 Helicopters - oil cooler blower
impellers
156-2
Bell 206 main rotor blade grip
167-4
Bogus helicopter parts - warning
82-1
Determination of retirement lives for Bell Model 47
helicopter components
166-2
Helicopter certification responsibilities and
examinations - changes
99-1
Helicopter fatigue critical parts - a lesson learnt
the hard way
93-2
Hughes Helicopters - Four Bladed Tail Rotor
Drive System
156-3
Hughes 269 helicopters - throttle cable assembly 116-1
Hughes 269 lower pulley bracket - misalignmentfailure
121-1
Propeller and tail rotor markings
87-3
Robinson R22 belt drive system
177-2
Robinson R22 'VEE' belts and sheave assembly
wear
144-7
Robinson R22 Helicopters - cyclic friction
adjustment
156-5
Rotor blades - protective tape - precautions
96-4
Sand erosion - gas turbine helicopter engines 112-1
Soloy Conversions - Hydrogen Embrittlement of
P/N NAS1305-2H Bolts
206-1
HOSES
Flexible hoses and fire-sleeving
Hoses - fire resistance standards
Powerplant flexible hose assemblies accuracy
122-8
94-2, 126-8
length
108-9
HYDRAULICS
Cleaning Hydraulic Components Using Alcohol
Based Cleaners
Hydraulic power pack maintenance
Hydraulic systems - mixing of fluids
Piper PA23 emergency hydraulic hand pump
Swearingen SA 226 - in service hydraulic leaks
Use the right part
202-2
101-7
131-1
23-3
143-4
177-3
IGNITION
Bendix rotate-to-start ignition switches
Faults caused by Bendix induction vibrators
Ignition switch alignments
Spark plug fouling due dust ingestion
112-3
4-6
17-2
8-1
INSTRUMENTS
Aeromarine type instruments
67-5
Agricultural liquid spray systems - direct reading
pressure gauges
174-3
Aircraft instruments - 'handle like eggs'
30-1
Airspeeds - the limits are indicated
1-1
Altimeters of US manufacture in general aviation
aircraft
106-6
Altimeters - temperature compensation
89-3
Cessna 150 instrument system
103-5
Cessna instruments - security of installation
120-3
Electrical turn and slip indicators 12V DC
55-2
Fuel contents and fuel flow indicator markings-AD/
INST/6B - CANCELLED
15-2
Gyro maintenance and handling precautions
48-1
Loud speakers and compasses
98-3
Piper PA23-250 magnetic compasses excess
deviations
98-2
Piper PA28, PA32 fuel quantity gauge erroneous
indications
99-3
Piper aircraft magnetic compasses
93-3
Presssure gauge connections
189-4
Teflon tape
104-9
Victa Airtourer fuel gauge transmitters
19-6
I
••
I
I
Iii
LANDING GEAR
Aircraft Undercarriage Systems
205-2
Beech 35 MLG - Murphy is alive and well
104-1
Beech Bonanza, Baron, Duke and Travel Air
Landing Gear Rigging
153-1
Beeech 76 nose landing gear door hinges
189-2
Cessna 188 main landing gear bolt fatigue
149-2
Cessna 310 and 400 - LG torque link shaft failures 31-6
Cessna LG down indicator failures
29-2, 84-2, 97-2
Cessna N/W forks
38-5
Cessna NLG Actuators - Rod End Fitting Failures 154-3
Cessna Singles - N.1 .G. down lock material
change
142-2, 150-3
DH82 Tiger Moth LG collapse
56-3
DHC2 Beaver tail wheel spindle cracking
7-6
Embraer EM B-110 Bandeirante landing gear
contamination
143-5
Heavy duty nose landing gear spacer assembly Gulfstream 695B nose gear steering pin
164-2
LG cleanliness
31-1
LG failures in single-engined aircraft
176-4
LG lubrication
76-3
LG maintenance
22-5
LG warning system maintenance
23-6
Landing wheels
17-8
Aviation Safety Digest 142 / vii
vi / Aviation Safety Digest 142
--
�Mooney M20 LG electric actuator
Piper PA28 backup landing gear extender
Piper PA28R Cherokee Arrow LG
Piper PA30 LG indication
Piper PA31 park brake
Piper PA31 LG downlock hook defects
Piper PA32 backup landing gear extender
Piper PA34-200 Seneca - incorrect assembly of
N.L.G. centering attachment bolt
Piper PA34-200T Seneca II - nose landing gear
fuselage mount assembly broken
Piper PA34-200T Seneca II - main landing gear
trunnion housing cracked
Scott T/W assemblies - maintenance
Tyre sealers
Tubeless tyres and tubes - troubles
Victa Airtourer LG strut housing
78-2
194-3
33-5
13-1
101-5
116-9
194-3
143-3
168-1
168-2
22-6
89-6
33-4
40-5
LICENSED AIRCRAFT MAINTENANCE
ENGINEERS
CERTIFICATION
Aircraft of plastic construction
Airframe and engine category review
Airframe grouping classifications
Revison of requirements
V.L.F, Omega and G.P.W.S
Welding authorities
112-2
139-5
144-3
120-2
112-13
72-1
EXAMINATIONS
AME examinations - 1988
193-2
AME Examinations - 1989
204-1
AME licencing examinations - results of
questionnaire
165-3
AME Licencing Examinations
161-2
Aircraft Maintenance Engineer Licencing - specific
examination 'J' category engines Pratt and Whitney
JT9D
163- 5
AME Licence examination courses Padstow TAFE
205-4
Category Radio
144-2
Change of examination centres
142-7
Completion of examination application forms
141-3
Concession against experience requirements
126-9
Dishonest Acts in examinations
145-4
Engine specific type examination Allison 501
174-1
Impending changes to examination procedures
175-5
Review of AME licence requirement
178-1
Revised AME Examination Syllabi Categories:
Electrical Instruments and Radio
168-4
Revised AM E licencing and examination system 193-1
Suggested study reference for AME licencing
examinations
168-5
TRAINING
Acceptance of overseas training and examinations 139-1
Acceptance of training courses in lieu of DofA
specific type AME examinations
178-2
Basic CN training course
186-3
Grant of an Australian AME Licence in recognition of a
foreign licence
178-3
Training for AME licence examinations
182-2
MAGNETOS
Bendix magneto - incorrect internal timing
117-7
Bendix Scintilla S700
4-2, 64-2
Bendix Scintilla S20, S200, S1200 breaker point
scr@JNS
70-1
Bendix Scintilla S20, S200 housing rework
8-3
Bendix Scintilla S1200 vent plug change
19-3
Bendix Scintilla S1200 distributor gear timing marks 52-4
Bendix Scintilla S1200 - primary lead insulation 36-3
viii/ Aviation Safety Digest 142
Bendix Scintilla condenser leads chafing
20-3
Bendix Scintilla contact spring height
23-5
Bendix Scintilla impulse couplings
55-1, 70-3
53-2
Fitting split pins in magnetos
Slick 4200 and 6200 loose fingers
197-3
27-3
Slick 660 Series - Cam oiler pad removal Distributor block attachment screws Slick 662 Distributor block screws tighteness
21-2
Slick impulse couplings
43-5, 70-3
Slick maintenance
43-2
Watch that magneto timing
64-3
With switch leads removed - Ground that magneto 3-5
MAINTENANCE SERVICING
Airborne dry air pump - improper maintenance
technique
63-2
Aircraft maintenance
textbooks
106-1, 108-10, 112-11, 162-4
Aircraft Undercarriage Systems
205-2
Approval and Certification of Modifications to
Aircraft
203- 1
158-1
Approval of Systems of Maintenance
27-4
Aircraft seat maintenance
201-2
Bell 47 bearing replacement
Cessna flap actuator maintenance
47-1
Cleaners, Polishes and Brighteners
10-2
Cleaning Hydraulic Components Using Alcohol
Based Cleaners
202-2
Component overhaul
192-1
Control cable inspection
41-1, 61-1, 67-2, 106-7
Control lever rod end wear
127-2
Don't use cadmium plated tools on titanium parts 31-4
Dopes and paints - alternate
197-2
Electric motors and generators - maintenance 201-2
Fabric - Airworthiness
22-2, 58-3
Fabric - Linen and cotton, replacement by
synthetics
81-2
Fairey Reed Propeller Maintenance
203-2
Fairey Reed Propeller Hub Nut Lockplate Cracking 205-3
Fire in hangar - poor maintenance practices
31-3
Fitting split pins in magnetos
53-2
Flight control system maintenance
46-5
Fluid lines, electrical looms - preventive
maintenance
18-5
Fluid lines - prevention of chafing
75-3
Flutter and aircraft maintenance
93-1
Fuel filter maintenance
108-3
GA maintenance
113-1
Hydraulic power pack maintenance
101-7
Hydrogen Embrittlement of P/N NAS1305-2H Bolts 206-1
Inspection and maintenance for fire protection
65-2
Improper tapped threads in turnbuckle bodies
PIN MS 212518
162-5
LG cleanliness
31-1
22-5, 76-3, 104-2
LG maintenance
LG warning system maintenance
23-6
Metal propeller blades - care and inspection
34-1
104-1
Murphy is alive and well - Beech 35 MLG
More on undercarriage lubrication
123-4
Oleo shock struts - servicing
108-5
Oil and fuel additives
130-1
Paint Stripper Application
205-1
Paint stripper, etc - hazards
23-1
144-8
Placards, decals and markings
105-4
PNG registered aircraft in Australia
Scott tail wheel assemblies - maintenance
22-6
Slick magnetos - maintenance
43-2
Structural inspection after abnormal loads
98-4
Structural inspection after heavy landing
31-5
Welding of tanks -precautions
30-3
Wooden propellers - maintenance
17-3
Wood rot
165-2
MAJOR DEFECTS
•
Defect reporting
Defect Report Summary
Major defect reporting
Major Defect Summary
Issue of revised MOR form (DA 132)
Report those defects - OR let's not tell them
130-4
166-7
209-1
94-5
209-2
28-1
METALS
Cadmium embrittlement
7-3
Don't use cadmium plated tools on titanium parts 31-4
Magnesium alloys
157-1
Mercury contamination of aircraft
90-2
METRICATION
Metrication -
aircraft and equipment
74-2
NOISE
Aircraft noise requirements
103-3, 160-3
NON DESTRUCTIVE INSPECTION
Don't be responsible for 'spectacular' inspection
failures
104-6
Exhaust system inspection
21-1
Magnetic particle inspection - AC magnetisation 198-1
Magnetic particle inspection of bolts
5-2
OIL
Aircraft engine synthetic lubricating oils
Cessna engine oil quick drain valve failure
Champion spin-on oil filter defects
Newly approved oil for piston engines
Oil container cap lock rings and seals
0-Rings
PA22, PA24 oil cooler pipe-lines and seals
TCM Oil filters - faulty threads
101-3
103-4
100-4
146-2
185-2
187-2
7-1
131-6
OXYGEN
Gaseous oxygen systems Oxygen system lubrication
Stowage of oxygen masks
fire hazard
115-1
72-3
85-3
PARTS
Aircraft components - U.S.A. P.M.A. produced
parts approved for use
142-5
Aircraft goods from U.S.A. - acceptable
documentation
115-8
Aircraft parts - standard parts used in critical
applications
32-2
Bogus helicopter parts - warning
81-2
Bogus parts
146-3
Bogus and non-approved aircraft parts
173- 3
PNEUMATIC
Airborne dry air pump failures
Airborne dry air pump improper maintenance
technique
Dry vacuum pumps
39-1
63-2
170-1
PROPELLERS
AD/PROP/2 - Functional check of feathering
propellers
11 7-3
Beech Musketeer - failures of governor drive
46-3
Effect of Low Ambient Temperatures on Propellers
Lubricated with Aeroshell No 5 Grease
204-4
Fairey fixed pitch propellers - installation
7-2
Fairey Reed Propeller Hub Nut Lockplate Cracking 205-3
Fairey Reed Propeller Maintenance
203-2
Hamilton Standard Pitch Stop Dowells
201-3
Hamilton Standard propeller blade corrosion
125-2
Hartzell 'Compact' propellers - blade tip failure 28-2
Hartzell CP propellers pitch change guide collar
slippage
44-3
Hartzell propeller amended overhaul period
177-5
Hartzell Propeller TBO - AD/PHZU43
173-5
Hartzell Propellers - inspection
145-1
Installation of McCauley C501 propellers
173-4
McCauley propeller blade ferrule cracking
80-3
McCauley propeller attachment Cessna 411 , 411A, 421
41-3
McCauley propeller hub cracking
16-1, 20-1
McCauley turbine propellers torque values
192-2
Maintenance of wooden propellers
17-3, 141-1
Metal propeller blades - care and inspection
34-1
Oil filled McCauley propellers
125-1
Oil filled McCauley propellers - red dye leakage 141-2
Propeller and tail rotor markings
87-3
Propeller balancing
120-1
Propeller care and inspection
179-3
Sensenich 76EM Series fixed pitch propellers blade modification
43-4
Use of correct propellers
45-1
Wooden Propellers
187-1 , 188-4
Woodward propeller governors - loss of control 47-2
RADIO
Airborne weather radar - radiation safety
precautions
84-1, 108-8
Aircraft loudspeaker failures
32-4
Aircraft radio installations and modifications
184-2
Aircraft radio station licences
199-2, 67-3
Aircraft VOA systems - testing
17-1 O
Approved Radio Equipment
182-3
Avionics Equipment - Environmental Categories 203-3
Burndept BE 375 non-buoyant survival beacon
160-1
Cessna 303 - H.F. interference in autopilot
139-3
DME(D) to DME(I) transition
. 194-4
Electrostatic Discharge (E.S.D.) 155-1 , 142-4, 143-6, 189-3
Elusive NOB idents
101-2
Feedback in transmitter circuits
128-1
Fouling of flight controls by radio cables
94-3
HF communications antenna systems
139-4
HF antenna broken in heavy icing conditions
104-3
HF communications - change to SSB
126-1
HF Double Sideband Equipment - deactivation 142-1
High power radio transmission - effect on aircraft
systems
157-9
Improper installation of ELT
159-3
King Kl 204 VOR/LOC GS indicator potentiometer
problems
112-4
King VOR/LOC GS meter indication unreliability
73-1
Loudspeakers and compasses
98-3
Mobile telephones - banned in aircraft
196-2
NARCO ELT 10 battery test and inspection
99-5
NARCO NAV 121, 122 - Connector wiring
116-5
NDB's Proposed use in the 1600-1700 KHz band 186-2
Non-aviation radio - use in aircraft
104-7
Secondary surveillance radar
192-4
Sunair HF transceiver ASB 125 - poor transmission 89-5
Survival beacons and CLBs
57-1, 75-1, 78-1
Testing of Survival Beacons
160-2
VHF communications frequency requirements
199-3
VHF survival beacons (VSB) testing and inadvertent
operation
57-1
VHF transceivers
67-4
VLF navigation system
112-7
WHEELS/TYRES
Aircraft landing wheels
Inflation of tyres with an inert gas
Tubeless tyres and tubes - troubles
Tyre sealers
17-8
195-4
33-4
89-6
Aviation Safety Digest 142 / ix
�RECORDS LOG BOOKS
DOCUMENTATION
SAFETY EQUIPMENT
Acceptable documents for imported aircraft and
materials
18-1
Aircraft goods from the U.S.A. - acceptable
documentation
115-8
Aircraft and Engine Log Books - revision
142-6
Aircraft Log Book - DoA Form 9
112-6
Aircraft time in service - records
120-5
Display - Nationality and registration marks
by foreign aircraft
122-5
Flight Manuals
158-4, 161-4, 164-6, 169-6, 173-7
Light Aircraft Log Book - new instructions
97-5
Log Book Statements
66-1
Military insignia - display by aircraft
145-3
Release Notes - unauthorised issued by distributors80-1
Retention of log Books
162-2
Recording TIS - GA aircraft
19-1, 198-1
Used aircraft - {un)reliability of records
115-2
REGISTER
Allocation and reservation of registration markings 12-1
ANR amendments - aircraft registration
50-1
Change of address proforma
148-5
The Aircraft Registry and reservation of registration
marks
155-3
WATER/METHANOL
Use caution
8-5
WEIGHT CONTROL
Aircraft weight control
Revere electronic weighing kits -
earthing
88-1
96-5
Approval of safety equipment
Approved life jackets
Life raft inflation - valve defect
Use of approved safety equipment
195-3
87-4
196-3
70-2
SAFETY HARNESS
Carriage of stretcher patients in aircraft
159-4
148-2
Cessna aircraft - seat belt modification
Cessna shoulder harnesses
183-2
Inertia reels for agricultural aircraft
113-5
Inertia reels for GA aircraft
200-2
197-1
Inertia reels - Pacific Scientific
17-1
Piper PA32 rear seat restraint
Safety harness requirements - front and pilot seat
occupants
15-3
Safety harness mismatch - Pacific Scientific rotary
buckle
130-3
Seat belt adjustments - possible misuse
87-5
Seat belts and harnesses - their use and mis-use 185-3
Sideways facing seat installations guidelines for
175-2
improved occupant restraint
Upper body restraint - Cessna 150
91-3
54-1, 69-4, 200-3
Upper body restraint in GA aircraft
5-3
Victa Airtourer shoulder harness
SEATS
Carriage of extra persons in standard seats - GA
aircraft
47-5
Seat maintenance
27-4
Seat security
30-4
Sideway facing seat installations - guidelines for
improved occupant restraint
175-2
WELDING
WINDOWS
Aircraft acrylic windows
83-1
Welding Authorities
Welding of tanks - precautions
72-1
30-3
MEA CULPA, MEA CULPA
ASD 141 carried some significant inaccuracies, for which we apologise, and explain thus:
(1) On page 5 we invoked Captain Murphy, who promptly, and retrospectively, upstaged us. There are,
to the best of our knowledge, no Twin Comanches equipped with magneto switches functioning as
battery or alternator master switches. Therefore, for 'magneto' read 'alternator and battery master
switches' . The photographs should, of course, have been centred upon the battery/alternator switch
system. It seems unfair to single out the PA-30 for obloquy - most light aircraft can be flown on
battery alone.
(2) On the back cover, top diagram, the pilot has neglected to state his position -
'Racetrack'. At
position 2, 'Descend to circuit height' is redundant. The aircraft needs wheels.
In the bottom diagram he certainly would have made the Tower Controller's day by calling '36 right',
then proceeding, without pause, it seems, to 36 left! The picture shows him initially calling 'Tower' normally at GAAP airfields 'Ground' is the first call, in which case the ready call should be prefixed by
station identification.
These errors are being corrected on the poster, and no, we didn't put them in merely to start you
talking; that way lies editorial suicide.
~viation
Regulatory Pro11osals
Aviation Regulatory Proposals (ARPs) are an important means by which the Authority consults
with industry about proposed changes to operational legislation and requirements. Copies of all
proposals are circulated to relevant organisations, and occasionally to individuals for information
and comment. The comment received provides a valuable source of advice which greatly assists the
Authority in the development of the completed documentation.
Each edition of the Digest contains a listing of those ARPs circulated since the previous
edition.
Should you wish further information about any of the ARPs, p lease contact your industry
organisation.
Number
Subject
Status
89/ 1
Amendments to CAO 20.7.lB Aeroplane weight and performance
Responses assessed by
31/ 8/ 89
89/ 2
Provision and use of oxygen and
protective breathing equipment
Completed CAO 20.4 redrafted
and in approval chain
89/3
Amendments to CAR 157 and CAO
20. 7.4 - singl e engine aircraft
operations
CAO 20.7.4 amended CAR 157
amdt with AGs
Your urgent attention is drawn to the article on page 5, relating to the need for an extra hazard check
to be carried out before commencing clean-up runs.
89/4
CAR 214 Maintenance Training
(Airworthiness)
Not yet circulated
Yet another tragic accident within the last few weeks emphasises this requirement.
89/5
Review of operating limitations CAO 101.55, 95.32 and 95.10
Responses assessed by
18/8/89
89/6
Removal of the limited IFR
procedure
Replaces 87 / 17. To be
circulated
89/ 7
Review of procedures for the
administration of standards for
international parachute descents
Replaces 88/ 14. To be
circul ated August 1989
89/8
Follow on Review Reg 191
Follow on 88/9. Responses due
31/7/89
89/9
Review of standard passenger
weights
To be circulated August 1989
89/10
AGA-7 Review
To be circulated circa 31 / 8 / 89
-
AG PILOTS V POWER LINES
No matter who you are, how good you undoubtedly are, or how experienced you are, if you neglect to
carry out a comprehensive re-check and re-location of wire hazards before commencing clean-up runs
or re-starting treatment on a field that you have been away from for an hour or so, you put yourself at
great risk.
The extra hazard check is of utmost importance for you as an ag. pilot take-off drills, which no one ignores.
I
more so even than the pre
For your sake, your family's sake, the operator's sake, and for the good of the industry as a whole
CARRY OUT THE EXTRA HAZARD CHECK BEFORE
CLEAN-UPS OR RECOMMENCING AFTER A BREAK
- NOW AND FOREVER!
Aviation Safety Digest 142 / xi
x /Aviation Safety Digest 142
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�Aviation Safety Digest
142
Aerospatiale AS 3508, 29 July 1988
AERONAUTICAL INFORMATION SERVICE AUSTRALIA
An untested strop w as used to lift an external
load. The rope of the strop slipped through the
whipped s ection of the eyelet, releasing the
load, and recoiled into the rotor. One blade was
damaged and one horizontal stabilizer was
r ipped.
NOTICE
CURRENT DOCUMENTATION & RLANNED NEXT ISSUE
Document
Current Issue*
Planned Next Issue*
DAP(E)
24.08.89
19.10.89
DAP(W)
21.09.89
16.11.89
--
AGA 0-1-2
04.05.89
II
03.05.90
...!I
Aerodrome Diagrams
21.09.89
16.11.89
ERSA
24.08.89
14.12.89
AIP (book)
24.08.89
I,,
•
14.12.89
VFG (book)
24.08.89
A IP/MAP
29.06.89
14.1 2.89
VFG/MAP
29.06.89
14.12.89
DAH
,,. ,.. .,-
14.12.89
29.06.89
•
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I •
•
-....
._._
•
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...:
...
•
...
J-~
..
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-
I
-
I
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•
*dates quoted are effective dates
..
•
•
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•
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xii/ Aviation Safety Digest 142
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•
The student parachutist's main parachute
deployed prematurely. The risers became
entangled in the horizontal stabiliser, damaging
it and locking the elevator. Both students and
the instructor evacuated safely and the pilot
made a safe landing on a salt lake with the
parachute still attached.
BAS! recommendation
The pilot's actions in saving the aircraft should
be publicly commended in the ASD. A second
recommendation on single pin, low deployment
pull parachutes was directed to the parachute
manufacturer and the Australian Parachuting
Federation.
·1
••
I
ISSUE: 7
DATE: 21 SEPT 89
CAA action
This response constitutes public
acknowledgement of the pilot's actions.
Piper PA28R-180, 17 October 1988
A cleaner reported significant damage to the
landing gear and wing spar. The damage indicated a vertical descent onto the left wheel first ,
followed by the right wheel. Upper skin damage
was evident to the left wing. All six pilots who
had been involved with the aircraft over the
preceding two days denied any knowledge of an
incident.
BAS! recommendation
The unethical action of not reporting this accident and the danger s of flying an aircraft with
such damage should be publicised.
CAA action
An article will be prepared for the ASD illus trating the hidden danger s w ith heavy landings
and t he need for adequate preflights.
Bell 2068, 4 December 1988
Grumman-Frakes G73T Turbo Mallard, 25
August 1988
Note:CLASS I & CLASS II NOTAM ARE TO BE CONSULTED
WHEN USING ANY OF THE ABOVE DOCUMENTS
.. -
CAA action
Alternative earthing points have been examined
but none are suitable. It is normal practice to
make such cables as conspicuous as possible
and the CAA recommends that operators follow
such procedures.
.1
•
•
BAS! recommendation
The CAA should remind pilots of the dangers of
oper ating helicopters w ith what may appear to
be only superficial damage. The CAA should
examine positioning of the earth cable jack
point or ways of making the cable more
conspicuous.
I
•
Cessna 172, 11 September 1988
Aerospatiale AS 3508, 20 August 1988
•
:.
CAA action
The CAA Standards Development Division will
be requested to draft a CAO Part 103 to specify
external load carrying support to comply with
Australian Standards requirements.
The jack t ype earthing cable was left attached
to the helicopter and part of the cable and the
clip were severed by the tail rotor. The earth
cable was removed and, as only superficial
damage was noted, the flight was continued.
Minor damage was s ustained by a tail rotor
blade but the tail rotor gear box was removed
for overhaul.
14.12.89
•
BAS! recommendation
The CAA should consider the implementation of
a standard for the construction and testing of
helicopter sling equipment.
CAA action
The accident is considered to have resulted
from inadequate maintenance. The responsible
maintenance organisation has been subjected to
a review.
During takeoff on the open sea, number two
engine failed due to sulphidation attack on the
compressor turbine. The prevailing conditions
resulted in loss of directional control and the
aircraft stopped on a sand bar. The left float
and pylon and three metres of the left w ing
were torn off.
BAS! recommendation
The CAA should introduce compulsory 200
hourly borescope inspections of turbine engines
operated in marine environments.
While attempting a landing at night on a medical evacuation, the helicopter encountered considerable t urbulence and wind shear. The loss
of airspeed and high rate of descent probably
resulted in a vortex ring condit ion and the helicopter hit the ground.
BAS! recommendation
The CAA should publish an article in the ASD
to r emind pilots to weigh the urgency of evacuation against t he possibility of a n accident.
CAA action
An article will be prepared for t he ASD illustrating this point 0
�, Aviation Safety Digest
142
Aviation SafetyDigest
142
Nil.4
Dirty fuel
revisited
Would you purchase dirty or contamin ated fuel
for your motor car?
Fuel associated problems are still plaguing
today's motoris ts despite the increased use of
in-line fuel-filters. Why, then, would you want
to take a chan ce in a less forgiving environment
t han your local highway by pu tting contaminated fuel in your aircraft? The in-line filter
has not cured the root cause of the problem for
t he motor ist, alt hough it has reduced t he incidence of such even ts. A similar problem ex ists
in General Aviation.
The Latin phrase 'caveat emptor', let the buyer
beware, sums up the situation. The only
alternative is for the owners/ operators/pilots to
go to great lengths to assure themselves of the
quality of the product they are using. The casual check for water in a soft drink bottle is
about as far as most pilots are prepared to go.
To suggest t h at a pilot should be required to
carry water detecting paste is fairly impractical
as well as being so onerous t hat it would not be
observed.
CAO 20-9 details the responsibilit ies of a pilot
with regards to fuel and refuelling. It is cle arly
established in t he CAO that pilots engaged in
RPT operations are required to obtain a Release
Note for aviation fuel and other necessary
fluids such as oil and hydraulic.
A Release Note is not just a receipt or invoice,
it confirms that the fu el/fluids meet the manufacturers specifications. Vendors of fuel and
other aviation liquids who are u nable to pro-
FUEL DISPENSING FROM A DRUM
FIG. 1
INCORRECT
FI G.2
RECOMMENDED
vide a Release Note should be treated with caut ion and t he standards of such things as storage
assessed prior to purchase.
By obtaining fuel and other liquids under cover
of a Release Note the purchaser is ensured that
wh at he has purchased not only meets the
stringent controls instituted by the oil company
during manufacture to agreed specifications,
but continues to be preserved in a fit and
proper manner for dispensing into an aircraft.
Oil companies ensure the continu ance of the
product's qu ality by appoint ing agents who
r egula rly monitor for compliance under the procedures specified in their organisation's Quality
Control Manual. Only such appointed agents can
issue a Release Note on behalf of an oil
company.
As we are all aware, most aviation ·fuel purchased at GA airfields around Australia is
obtained in less formal circumstances. Distribution systems for non-authorised 'agents' vary
from bowsers and t railers (often not inspected)
to the more usual 200 litre drum. Release Notes
cann ot be obtained from such sources and contamination is a known problem .
The storage and handling of aviation fluids
from delivery at t he aerodrome to dispens ing
into an aircraft is our area of concern. CAO
20-9, subsections 3.3 and 3.4, contain notes on
some s imple safeguards which should be
observed. CAO 20-9, subsection 4, details precautions to be observed during aircraft
refueling.
When obtaining fuel from any source it is recommended t h at you request from the vendor a
Release Note. If one is provided, y ou may
reasonably assume that what you receive is
wh at you expect and have paid for. No release
note - caveat emptor!
FUEL DRUM STORAGE
FIG.3
INCORRECT
FIG.4
RECOMMENDED
J)l~l~l~C~'l'S
Vendors of aviation fluids are recommended to
institute some system of control. It need not be
too sophisticated or involved, but it should
show such items as delivery dates, water
checks and persons performing duties.
When refuelling from drums, remember that the
drums s hould always be bonded to the aircraft
before a fuel hose is allowed to touch the aircraft; a little spark can cause a big fire. Always
ensure an in-line filter is installe d between the
drum and the aircraft's t ank and that the drum
is tilted slightly away from the pump. (See figures one and two). Fuel drums should be stored
as in figure 4 t o keep both bungs covered 0
Helicopter hoist
hooks
A recent review of incidents which occurred
during hoisting operations has shown the need
to assess the acceptability of some hoist hooks.
There have been at least two repor ted cases
where the load on the hoist disengaged from
the hook. In both instances the load rested on a
protuberance (skid , footrest) outside the helicopter door sill, thus relieving the hook of the
weight of the load. With no weight on the hook,
it was easy to twist the 'D' ring up the hook to
rest on the safety latch. When the load was
reapplied, it slipped t hrough the safety latch.
This is just one way the load may disengage
from the hook. Our assessment has s hown that
hooks are susceptible to three modes of failure :
• Load relief. As already described; the hook is
relieved of the weight of the load allowing the
'D' rin g to travel up the hook and disengage
when t he load is reapplied.
• Torsion. The 'D' ring-hook throat torsion
causes the 'D' ring to ride up the throat and
subject t he keeper to a side load. The keeper,
being unable to react to torsion, fails under
excessive side load.
• Load jolt. During a jolt to the load, the 'D'
ring jumps up around the keeper and rests
against the keeper on the tip of the hook. As
with case one , when the load is reapplied t he
keeper allows the 'D' ring to s lip t hrough.
In gene ral, operators should:
• Pay close attention to the selection of
hook/'D' ring combinat ions; and
• Exercise care when attaching the 'D' ring to
the hook 0
Will it save your
life?
Item: Life jacket RFD Type 102 Mk 1.
Malfunct ion: Life jacket deflated during pres sure test.
Nature of defect: Life jacket material porous.
Known problem for this model and age jacket .
Comment: This jacket was owned by a private
a ircraft owner w ho was not aware of the
AD/ EMY / 2 amendment 4 requirements,
although he h as imposed his own 18 month test
period. Ther e are probably hundreds of priv at e
aircraft owners with their own life jackets who
are not aware of test requirements or who do
not know that life jackets have a finite life.
Many of these jackets have probably never been
tested.
These details were taken from a defect report
prepared by the CAA earlier this year. The suppliers advised that the jacket was manufactured in January 1976 and that the average life
of a jacket is api;>roximately 10 years .
All safet y equipment are forms of insurance you hope you will not need it but, if you do,
you are glad - relieved even! - it is t here and
works.
For particular operations, safety equipment is
mandatory . CAO 20.11, for example , requires
that air craft engaged in RPT and charter operations over water should carr y life jackets.
However , any pilot operating over water
(including lakes, bays and ha rbours) would be
wise to carry a life jacket for each occupant.
Equ ipping your aircraft w ith life jackets (and
other safety equipment) is pa rt of t he solution.
Ensuring t hat the equipment r emains servicea ble is the other vital part of the solution.
The pearls of wisdom that led you to purchase
the equipment in the first place should a lso
lead you to maint ain that equipment in a
serviceable condition . Folded and stowed life
jackets are quite v ulnerable to deterioration.
Manufacturers issue maintenance instructions
for their products. The CAA has issued
Air wort hiness Directives - AD/ EMY/ 2 amendment 4 for life jackets a nd AD/ EMY / 4 amendment 5 for life rafts . These can be found in the
CAO 107 series.
If you fly over water, a life jacket is good
in surance.
If you carry life jackets, ensure they are
serviceable - just in case 0
�Aviation Safety Digest
142
Aspartame not for the
dieting pilot?
SPARTAME is a synthetic compound of two
amino acids (aspartate and phenylalnine)
bonded by methanol. So w h at? Aspartame
is a widely used food and drink sweetener, particularly used in place of sugar. And evidence
from the United States suggests that for some
people aspartame produces reactions which
pilots would rather not have.
The issue appears to have been hotting up
throughout the 80s in the States. A number of
pilots have informed the FAA of various symptoms which they attributed to the use of
aspartame. Some of these symptoms were bad
enough to result in loss of licence.
A pilot report this year to the FAA followed a
night flight before which the pilot had drunk
two cups of hot chocolate artificially sweetened. He stated: 'During the final night leg of
the flight, I found myself unable to see the
instruments clearly because of blurred vision. I
remember the controller asking me my airspeed.
I w as confused and unable to read or interpret
the instrument, so I gave him my DME digital
readout which was in large, bold numbers. I
maintained altitude by keeping the big white
needle straight up and down on the altimeter . I
felt apprehensive, insecu re and 'way behind the
airplane'. I knew that if I had a real in-flight
emergency I would be unable to handle it, since
I was already in an overload condition'.
Some of the symptoms reported include: severe
continuing headaches; nausea; v ertigo; blurred
vision; memory loss; gastro disorders; seizures;
hearing loss; rashes; and numbness. Some of
these reactions have been severe enough to
result in suicidal depression and loss of limb
control.
Neither the company which manufactures
aspartame, nor t he United States Food and
Drug Administration (FDA) nor the FAA have
acknowledged the reported symptoms as being
caused by aspartame. Both the manufacturer
and the FDA have indicated that other causes
could result in the reported sympto.ms. The
FAA has not yet made a definitive ruling on its
position.
Although these symptoms are not officially
ascribed to aspartame, a growing number of
people, including some doctors, believe that
aspartame does cause these symptoms in some
people. Cases have been reported in which a
person has gone onto an artificial sweetener for
the first time, suffered adverse symptoms and
finally recovered after stopping the use of the
artificial sweetener.
If you regularly use an artificial sweetener containing aspartame and have had no adverse
reaction you probably have nothing to worry
about. But if you are an occasional user of
these products or ab@ut to use them for the
first time, monitor your reaction and do not fly
until you are sure you suffer from no ill effects.
Reference materi al supplied by Texas
Aspartame Consumer Safety Network 0
Yes, I usually make a high and low recon before I land in a
strange area but I had to get down real quick. My stomach
was acting up pretty badly and I didn't think I could make
it to our destination. No, I don't usually see the doctor for
an upset stomach. Anyway, he wouldn't give me my usual
medicine which I ran out of yesterday. I don't suppose
you could call it a real forced landing, though. There
wasn't anything wrong with the helicopter until the skid
dug in and it rolled over.
Taken from an old accident report.
Frontal weather
Bureau of Meteorology
,.., FRONT is a major weat her s ignal. By its
very nature it separates a ir masses of dif:.::;ferent properties and may be ass ociated
with many kinds of weather.
The most frequent form of front experienced in
southern Australia is a cold front; this occurs
when an airmass moving from higher latitudes
sweeps across the continent. The cold front is
associated with changes, which may occur rapidly, in wind, weather, temperature and
humidity. It extends into the upper at mosphere
and slopes westward with height, a typical
frontal s lope being of the order of 1:100. Its
speed of movement may vary, with an extreme
value of the order of 60 knots being observed
on Ash Wednesday 1983. Cold fronts tend to
lose their characteristics if they intrude into
low latitudes, where the cold air following the
front rapidly becomes modified by moving over
the warm tropical surface.
Pilots must be concerned with:
• The wind changes across the frontal
boundary.
• The cloud. In spring and s ummer particularly
lines of cumulus and cumulonimbus cloud may
form up to some hundreds of kilometres ahead
of the surface position of the front.
• Other hazards, eg vis ibility reduction, turbulence (which may be particularly severe if
associated with convective cloud), wind shear
etc.
The structure of the cold front itself may be
quite complex in terms of the changes in wind,
temperature and cloud; consequently careful
at tention to detail is required if t ravers ing a
frontal zone. The follow ing points are recommended for consideration:
• Prior to flight det ermine whether any fronts
may be in t he vicinity of your selected flight
route; if so, check the location, speed of movement or expected posit ion, associated cloud ,
weather, vis ibility and t he magnitude of the
wind shift .
• If flying through a frontal zone it is usually
best to fly the most direct route (provided
VFR conditions permit for t hese flights).
• Be conscious of the impact of the wind change
on navigation.
• Plan for alternatives if penetration is too
dangerous.
• Conv ective turbulence associated with a cold
front is particularly severe and can extend
well outside the cloud.
• Be extremely wary of flying through mid level
cloud ahead of a cold front , as t here may be
embedded cumulonimbus cloud. In these circumstances icing can occur suddenly .
One type of front worthy of special ment ion is
the 'southerly burster' (more commonly
referred to now as the 'southerly buster' and
once even called the ' brickfielder'!) along NSW
coastal area. This fas t moving cool change may
bring low cloud and thunderstorms or be
experienced as a sh arp wind change without
cloud. There are a number of features of the
sout herly burster of which the pilot must be
aware:
• It has an extremely turbulent edge.
• It frequently accelerates when travers ing t he
NSW coast.
• Its movement inland may be retarded b y t he
mount ains, wit h the surface pos ition ass uming
a ' bent-back' configuration.
• It may develop ahe ad of a Southern Ocean
front 0
�Aviation Safety Digest
Aviation Safety Digest
142
142
- - - -- - - --- -- -- - --
-
----
- - -- --- -----
Dear Sir,
I refer to Pilot Contribution 'Flying to the Black
Stump' (ASD 140) an excellent, albeit thinlydisguised, lecture on outback flying.
As informative as the article may be, I fear it
may tempt the inexperienced adventurous types
to follow suit.
I occupied the right hand front seat on a trip to
the Birdsville races in 1985. We departed from
Townsville, North Queensland, and I would
loosely estimate that about 75% of the journey
was flown over fairly barren territory.
Although he did not make a big issue of it, I am
reasonably sure that our own pilot, Frank, an
experienced and competent holder of a CPL,
was glad to have another pilot (or experienced
navigator) checking his navigation while he
concentrated on the workload of flying the aircraft - on course - over that nearly featureless land.
I firmly believe that no-one but an experienced
Outback pilot should undertake that type of
cross-country flying unaccompanied by another
pilot or at least a skilled navigator. The
Outback is a Hell of a place in which to get lost.
Yours faithfully,
Denis Myles Lewis
The contribution was definitely not a lecture. It
was meant for discussion. Thank you for discussing it and passing on all your ideas.
Dear Sir,
Reading 'T~aps for Young Players' (ASD 139),
Trap 1 reminded me of an incident that
occurred several years ago while still a student
pilot. My instructor also used the 'mixture control to idle/cut off' technique for simulating
engine failure, as I had the habit of keeping my
hand firmly on the throttle to overcome his
annoying habit of constantly closing it.
After a session of solo circuits one afternoon, I
taxied to the apron, parked the aircraft and
commenced the shutdown checks. As I pulled
the mixture to idle/cut off, there was little
resistance and several inches of cable appeared
from the instrument panel. The engine stopped
Uust) and I went in sear ch of the Chief
Engineer.
Needless to say, after relating the incident to
my instructor, he never used the same technique for simulating engine failures. Had the
incident occurred in the training area, it would
definitely have been a case of 'Taking over!'.
Yours sincerely,
Geoff Williams
Simulated is simulated, not 'jor real'.
Dear Sir,
Re: Recency /currency
Reading ASD 139 has reminded me of a problem
that pops into mind from time to time.
Having just renewed my restricted licence for
the first time since obtaining it, I checked to see
the hours I have flown. I was very surprised to
s~e th~t I held less than ten hours total flying
time smce 1987.
The surprise was not as you would expect at
how little I had flown but that people in the
same situation as myself are not put to more
stringent tests. At this point I should point out
that my financial burdens have been increased
by marriage and the purchase of a house.
As I could not be considered proficient in the
fields of recent experience, aeronautical experience, knowledge and skill, should I 'be reissued
with a licence to fly an aircraft? I may be burying myself with these comments, but I would
really like to know the general opinion of other
pilots.
I do not see my situation changing in the near
future, but justify renewing my licence on the
grounds of:
• my love of aviation,
• a hope to obtain and fly under full PPL, and
• that I don't see myself jumping into an aircraft and taking off into the wild blue yonder
without first being fully proficient.
'
Discussion on this topic, be it good or bad for
me , would be appreciated.
Yours faithfully,
C.P. Hird
I, too, would like to hear other opinions.
Dear Sir,
Time and time again I have noticed media and
amateur photographers, when taking aviation
type photos, have this desire to have pilots and
people touching, leaning on or entwined around
propellors.
In my private pilot days, it was standard
throughout Australia to drill all concerned that
ALL contact with propellors was dangerous and
unnecessary contact was extremely foolhardy.
I wonder when this 'hands on' technique will
become a 'hands off' event.
Yours faithfully,
RE Baird
Agree. I once shooed a group away from the
propellor of a homebuilt when I noticed the
keys in the ignition were still on - and the
engine was very warm!
Dear Sir,
In response to your article 'Beyond the call of
duty', I do have a couple of points to make.
Firstly all commercial pilots should belong to
the Australian Federation of Pilots. Should a
pilot be sacked for not flying outside CAO 48.l
then he could obtain full representation by the
AFAP to secure his position back again.
Secondly and even more to the point is the
CAA's toothless tiger approach to deal with
companies breaching CAO's. If a pilot is sacked
because he won't breach flight time limitations,
fly overweight aircraft and unserviceable .aircraft, then a full investigation by CAA should be
made and, if necessary, the full weight of the
law brought down on the company involved.
If pilots could be assured of companies being
charged for breaching such CAO's by CAA, then
we wouldn't have to worry about being sacked
for not breaching them ourselves to get the task
completed.
I will bet you the company involved with your
story has not been charged for obviously rostering a pilot outside 11 hours duty and thus
breaching CAO 48.1.
I believe this is where you must start. Make
companies aware of their responsibilities and
discourage profiteering outside the CAO's.
Yours faithfully,
Bill Hobday
Dear Sir,
REF: 'Beyond the call of duty' ASD 140
I recall hearing of a similar occurrence from an
acquaintance who was asked to phone his
employer after landing at about midnight, following a very strenuous couple of days flying.
He was given details of another charter flight
to be commenced immediately. His protests
about fatigue, flight times etc. were met with
the question:'Do you want your job or not!'.
In both these instances, MANAGEMENT problems were off-loaded onto the pilots as OPERATIONAL problems, and in both cases the
assent of the pilots was necessary for this
'off-loading' to happen. No doubt, any consequent accident would have been headlined as
'pilot error'.
I suggest that any pilot, finding himself in a
similar situation, should cast his mind back to
r/ING l/t..lCK CL.E:AI<.
lolAK~-OFr.".'I'
his initial visual navigation exercises,' where
great emphasis was placed on 'seeing the big
picture' instead of trying to navigate 'from
crossroad to creekbed'. The same emphasis
needs to be applied here, - that is, think of
the problem as a whole, and throw in a few
'what ifs' for good measure. Don't think merely
of how to get from 'A' to ' B' while fatigued/ out
of hours/ hungry/ depressed/ frustrated/ angry/
lonely!
There are situations where even the most st able
and loyal pilots need to call on the added
weight of their industrial 'union' or 'federation'
when pointing out to managers what their legal
obligations are: NO pilot should fear for his job
if placed in one of those 'damned if you do and
damned if you don't' situations. There is
enough stress in the occupation already.
Yours faithfully,
J P Gammon
Dear Sir,
I think it's about time somebody said
something!
It appears to be a regular thing these days to
see single engined aircraft takeoff and have
their undercarriage retracted at an altitude of
ten feet, with three to five THOUSAND feet of
runway still in front of them (CAA included).
When I learned to fly , it was one of the BASICS
that you didn't tuck your wheels away until
they were no longer of any use to you.
Although reliability of engines has improved
greatly over the years,as far as I am aware,
engine failures do still happen occasionally.
Maybe they are all just twin-drivers who forgot
they only had one throttle lever this time, but
even so, who wants to struggle around the circuit on one engine in an aircraft which may or
may not climb, when they could easily shut
both down and land safely straight ahead on
the remaining runway?
A final note for the 'it will never happen to me'
pilots - just remember the non-current pilot
who went around in a Cessna 210 (power up,
gear up, flaps up) and promptly sank back onto
the gravel strip, with lots of nice loud scraping
sounds from underbelly and prop ...
Yours faithfully,
Marcia Hremeviuc
·n. \1S ~1-\oUL..0 eG
1N1"~R~S11 NG>.':'"
�Aviation Safety Digest
142
Aviation Safety Digest
142
Aquaplaning
IRCRAFT (PA-31) overran runway on landing. Aircraft landed in heavy rain, plus
crosswind, and aquaplaned on wet runway,
overran end of runway and came to rest in a
drainage ditch. DAMAGE: Minor.'
Part of the BASI initial report. Unfortunately,
the ditch was full of water and the aircraft was
extensively water damaged.
Aquaplaning (or Hydroplaning) is something
many of us have learnt to live with after the
phenomenally wet season on Australia's east
coast. If nothing else, then, maybe this article
will persuade the rain to go away!
Aquaplaning in an aircraft is the same as water
skiing along the runway. It affects aircraft of
all weights and sizes. The tyre is lifted clear of
the hard surface and a layer of water prevents
direct contact with mother earth. The tyre may
slow to a stop, it may even reverse direction; it
may not, on initial 'touch down', break through
the water surface and so not spin up to speed.
Aquaplaning comes with three hats: viscous,
dynamic and reverted rubber.
Viscous aquaplaning usually occurs on very
smooth runway surfaces. As little as 0.025 mm
of water depth is needed to help viscous
aquaplaning along the way. Major danger areas
are the runway thresholds, where painted surfaces and rubber deposits will aid the onset of
viscous aquaplaning.
Dynamic aquaplaning is usually brought on by
a high aircraft speed and relatively deep standing water. Runways without adequate water
run-off are most susceptible, as are runways in
areas where heavy rainfall can be expected.
Even a runway with a high crown may have
standing water if t he wind is strong enough to
prevent water run-off.
,,
. ..
'.¥' .
Reverted rubber aquaplaning can occur when
a locked tyre is skidding along a very slippery
wet or icy runway. It is usually the result of
locked brakes and can continue until the aircraft stops. It normally follows after either viscous or dynamic aquaplaning. High
temperatures are formed which result in the
rubber reverting to its original state, losing the
tyre tread (a flat spot) and filling tread with
molten rubber.
The speed above which tyre aquaplaning is
most likely to start is found from the formula:
V = 9Jp where 'V' is the aircraft velocity above
which the tyre will commence to aquaplane and
'p' is the tyre pressure in p.s.i. For tyre pressures in kPa, the formula is: V = 3.43Jp. If you
are landing on a very wet runway and the
wheels are not rotating before touchdown, the
aquaplaning speed is much lower. In this case,
the psi formula becomes: V = 7. 7 Jp and the kPa
formula: V = 2.93Jp .
From the first formula, a small aircraft with
main wheel tyre pressures of 25 psi would have
a dynamic aquaplaning speed of 45 knots. At
any speed above 45 knots you can expect to
aquaplane. If you then run into pooled water on
the runway, you may expect reverted rubber
aquaplaning well below 45 knots. And if you
then find yourself on the rubber deposits and
painted threshold at the far end, you can
expect viscous aquaplaning! Three ways to get
you!
If we next consider the problems of crosswind,
the aquaplaning theory becomes even more
complicated and a safe landing much more difficult. As you slow down on the runway, the
relative effect of crosswind will increase,
tending to force you to the downwind side of
the runway. If you are aquaplaning, you have
no control below rudder effectiveness speed
other than asymmetric power. Rudder is fine
while it is effective. But beware when
aquaplaning stops; you will not be pointing
straight down the runway, and when those
tyres suddenly grip you may be off the side of
the runway before you know it. Playing with
asymmetric power (reverse) is a last ditch resort.
Some considerations then:
• Smooth, flat runways with poor drainage, rubber deposits and painted surfaces are the
worst. Runways with high crowns, textured
surfaces or grooves are the best.
• Be wary of wasting runway. If you encounter
viscous aquaplaning at the far end just before
turning off, you may end up in the overrun.
Therefore, avoid landing long, avoid excessive
touch-down speed and do commence slowing
down without delay.
• Tyre tread is important. During the preflight
check the amount of tread. If it is low, be prepared to aquaplane.
• On landing, ensure the aircraft is pointing
straight down the runway at touchdown and
avoid 'greaser' landings. Lower the nosewheel
without delay.
• Commence braking immediately, using the recommended technique for the aircraft. Raising
the flap at this stage will put more weight on
the wheels, but if you are already
aquaplaning you will get more aerod~namic
control by leaving the flap down. Check the
recommended procedure for your aircraft
type.
A sequence of
events
The aircraft that I was to fly was an IFR
equipped Cherokee 180 and was booked to
depart Taree at 7 .30pm. The aircraft is
equipped Dual Nav/Com. On arrival at Taree
aerodrome at 6.30pm I found that the aircraft
had not yet returned from a VFR flight to
Kempsey. I had planned to depart before last
light to enable me to look at the weather and
cancel if necessary.
Pilot contribution
• Ensure speed is safe before turning off the
runway.
• Be aware of the added hazards of crosswind
and seriously consider landing somewhere
else.
• Before takeoff, remember to consider the
extra hazards and ground roll if an abort is
necessary D
WARNING BELLS were beginning to ring within
myself but I did not recognise them.
URING THE CAA/ AOP A Pilot Awareness
Seminar at Port Macquarie, I spoke briefly
about an incident I experienced as the sole
person on board during a Night VMC flight. As
this incident had a dramatic effect on me personally, I thought the story may help others.
I am 41 years old and have held an unrestricted
private licence for some 13 years with about
340 hours. I obtained my Class 4 rating several
years ago. I am a firm believer that a successful
flight is conducted by a thorough preflight on
the ground before departure.
The intended flight was from Taree - Coffs
Harbour (via Kempsey) - Port Macquarie Taree. An area 20 weather forecast obtained
from Coffs Harbour at 5pm dictated a change of
plan due to enroute marginal conditions. I then
planned Taree - Kempsey - Port Macquarie
-Taree at leg altitudes of 5000, 5500 and 6000.
The flight plan was telephoned to Coffs Harbour Flight Service Unit. I nominated Port Macquarie as my alternate for Taree which I had
nominated previously when flying this same
route. The Flight Service officer would not
accept Port Macquarie and insisted on Coffs
Harbour as the alternate. I did not think to ask
why, because he seemed so sure. I quickly
rattled off a time interval and a distance off
the top of my head without working it out or
looking at a map.
• In 40 minutes I had to go to the toilet four
times, each time passing considerable amounts
of water. Body language I am aware of but
did not recognise.
• As the time reached, a nd passed, 30 minutes
before departure time with no sight of a
returning aircraft, I became more on edge as
my pattern was being upset.
• I made a telephone call to Coffs and amended
my departure time to 8pm.
When I rang, the Flight Service officer advised
me that he had corrected my time interval for
the alternate, Coffs for Taree. After checking, I
appreciated that the error, though small in
space, could have been large in consequence if
overlooked (68 nm and 42 minutes).
The aircraft arrived at 7.30pm. The pilot
advised that the return altitude that he flew to
remain VMC from Kempsey to Taree was 3500
and there was no rain about. This height was
less than my planned altitude of 5000 but I
decided that the cloud base may have been an
isolated section. The weather forecast indicated
scattered cumulus 2500/7000 with broken
cumulus north of Port Macquarie, tops to
10 OOO, so I continued, departing Taree at
7 .52pm and climbing to cruise at 5000 AFTER LAST LIGHT.
�Aviation Safety Digest
Aviation Safety Digest
'--'....___.142
The night was pitch black with reflections off
cloud bases from towns along the coast. When
abeam Port Macquarie at the planned time, I
reported my position with intentions to leave
5000 for 3500 to remain VMC. The lowest safe
Taree-Kempsey is 4200 with the highest point
about 8 NM behind me, so I thought it OK to
descend to the lower height to remain clear of
the dreaded cloud that seemed to be threatening. At this time I engaged the automatic pilot
to give me more time to watch outside. And
then a SAL aircraft on the ground asked me to
relay messages to Coffs Harbour.
The workload was building up: lowest safe, was
I definitely clear of high ground, changing radio
frequency, position confirmation, radio relays,
cloud present, pitch black night, fly the aircraft
(with the automatic pilot on), read the instruments, look outside, look for cloud, look inside,
look outside etc, etc. Kempsey visual about 9-10
miles in front, where it should be - phew, good.
BANG - Nothing outside, only the noise of the
plane and dull lighting inside.
IN CLOUD
My body went a deathly cold, the plane seemed
to go very cold, no longer a friend. PANIC What do I do, it's happened, caught in cloud.
For about 20-30 seconds everything seemed to
stand still. Well, I thought, get a grip on yourself, leave the automatic pilot on, it does not
know that you may be about to die and will
keep the aircraft straight and level at least.
As strange as it may seem the thought crossed
my mind at that time wondering what they
would write in the Aviation Safety Digest about
this crash.
I checked all the flight instruments to re-assure
myself that everything was OK because the seat
of my pants had the strange feeling that the
aircraft was in a slight turn to the right with
me lea ning to the left. The instruments did not
support this. Heck this feels terrible . Look to
the left outside, instruments, front outside,
instruments, right outside, instruments, above
outside, instruments, still no lights or stars.
In a numbed state of mind, I did this all in a
regimental manner as I used to in the army,
even though it didn't seem to make sense as to
why and what I was doing it for. I started to
talk to myself and my maker and started to
think what it would feel like when I hit the
ground.
This lasted for four minutes and was possibly
the longest four minutes of my life. Suddenly, a
light to the left, several lights to the right, a
group of lights in front - CLOUD GONE,
almost over Kempsey.
142 ....___
Back into action again, I made a radio report
and needed to dodge all the cloud I could now
see 22 miles out of Port Macquarie. Coffs asked
me to confirm my time Port Macquarie as 36.
My answer, with all the deviations, was a guess
and I amended to 42. I arrived over Port Macquarie at 36 exactly!
I entered the circuit at Port Macquarie and
landed with one of the best approach and landings I h ave ever done. I did a slow turn-around
and departed for Taree only for problems to
occur as soon as I lifted off.
Oh, dem sticky
valves ...
Pilot contribution by Warwick Budd
My little clip-on torch fell as I adjusted my position on the seat, lodging just out of reach near
the r ight rudder pedal. To maintain orientation,
I turned right towards Port Macquarie city to
give me a horizon as I attempted to retrieve the
light, without advising traffic. Another aircraft
did ask me if I was turning right, which I confirmed. The torch was retrieved without problem and I set track to Taree.
Several weeks of hard study occurred and I
then sat for my Command Instrument Rating
theory examinations. If successful, by the time
this is printed I should have a Command Instrument Rating added to my licence.
For those who h ave been through similar incidents, and those who have not, please don't
rate yourself in the category that it will not
happen to me, because it can, as I found out,
and it is a period of time that I never wish to
repeat.
Call this article what you like, I can only call it
hard-earned experience. Any comments that
may be made on this particular occurrence can
only be of benefit to me and my flying.
This story illustrates an area of the unknown
for many of us. Keeping your cool and using the
autopilot obviously saved this pilot. Planning
for the future should prevent it hap pening to
him again. But why voluntarily fly night VFR?
If you wish to regularly fly at night, do as this
pilot has done - get a command instrument
rating D
And the problem did then go awa y.
I like telling the story any how - perhaps it is
like wanting to show everyone your freshly
removed appendix, but in t his case I'm telling
t he story because it might help others.
The important thing is that there was no reason
to h ave gone so long wit hout correctly ident ifying the problem. When doing the daily inspection on the day t he problem first appeared we
h ad not iced that only one cy linder had really
good compression and that t he others were very
low. We just didn't take enough notice of the
fact. Sticking v alv es will make the compression
very low , and the difference after the engin e
h ad its operation was r emarkable.
I gave the departure report to Coffs with an
amended altitude of 4600 (Non-Quadrantal) to
remain VMC. The cloud base remained about
1000 ft above all the way to Taree. I arrived
overhead Taree at exactly the planned time
interval of 20 minutes, cancelled my Sarwatch,
made another very good landing, put the aircraft into the hanger, completed the paperwork,
locked up the club rooms and went and sat in
my car. All of a sudden I didn't feel like going
anywhere, even the two kilometers to my
house. I had a tremendous headache which persisted for several hours after I arrived home.
The whole night leading up to the flight, the
actual flight and aftermath will remain in my
memory for a long time and is a night that
prompted positive action on my part which will
help me greatly in my future flying.
Until t he day it ran worse than ev er and clea rly
wasn 't going to come good. So instead of going
to Ayers Rock we went to see a LAME. H_e
looked at the en gine and immediately p ointed
out the bent ex haust v alve pushr od OR number
four cylinder. It turned out t hat three of the
four exhaust v alves were sticking and had to
have their guides cleaned of accumulat ed carbon. 'Twas a wondrous thing to see the job
being done wit h hardly any disassembly of the
engine.
ECENTLY I realised a long-held ambition
and, in company with two other pilots of
:.._ rather more experience than my own, flew
a Warrior around a large part of Australia. We
had a magic trip and I'm willing to share our
experiences with anyone who has a day or t wo
to spare to listen and watch a million or so slides.
R
But there is one experience that I would like to
share more widely and about which I'm willing
to be brief enough not to bore people to death.
It all started when we lit the engine for our second day's flying. To say t hat it ran like a hairy
goat would be ch aritable - but, after a minute
or so of very lean running, it smoothed out and
passed all the power tests with no trouble, so
on we went, westward-ho!
The problem recurred sev eral times, and always
responded to the same treat ment . We concluded
it was plug fouling, and were reassured when
some CPLs we consulted thought so too. Six
p lugs were changed during a 100-hourly inspection that was done in Perth but, alas, it wasn't
long before we had the problem again.
So we continued as before - pay careful attention to leaning the mixture and be prepared t o
let the engine have a bit of t ime to settle down
after being started.
Appa rently it is well known that t he exhaust
valves of Lycoming 0-360s tend to become
sticky about 1100 hours from new or after a
t op ov erhaul. So, if your engine fits this
description, has poor compression on a cylinder
or two or three and runs roughly after a cold
start, watch out for sticking v alves. As it
turned out we were lucky and the earn-follower
was not damaged - if it had been it would
h ave been necessary to remove the engine and
split the crankcase to fix it.
Alice Springs is a nice place to spend a few
days, if you've planned it that way D
�
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Aviation Safety Digest
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Aviation Safety Digest, number 142 (Spring, 1989)
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142
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1989
-
https://collections.heritageoftheair.org.au/files/original/ba7e8d1594fbcc620de4e4defc8fa5bc
966e2db446664903f8f97cc6483c23ba
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ATIS, altitude, lane of entry, initial report to tower at q
Check local procedures to overfly, circuit direction.
Abeam upwind end -descend to circuit height, make
downwind report.
No base call but landing clearance is required.
Go-around active side - climb to circuit altitude,
,
rejoin circuit upwind .
dfp111t1rtes
ATIS, report taxiing
Report ready
Depart zone by extending leg - runway heading, cross or down
wind remain clear of LOE and q
Endeavour to be above IOOOft by boundary - check local
procedures
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Establish communications if required with appropriate agency.
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Check.local pro"cedures for entry I exit through CTA
Pilot is required to sight traffic and maintain separation
Notify ATC if unable to comply or sight traffic.
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�Contents
Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots). registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Pilot-induced electrical failure in
controlled airspace
5
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
TAF: Terminal aerodrome forecast
The Publications Distribution Officer (EPSD)
Civil Aviation Authority
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
Aviation Safety Digest is a/so available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Statement by Alan Heggen,
Group General Manager, Safety Regulation
Don't tell anyone
1
What goes up .
1
QUIZ -
14
Engine icing
15
Ice -
1
Forced landing after takeoff
18
Enter at own risk
.!
Flight plans
Subscriptions may a/so be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
yet another way to get you
2
NIL DEFECTS
22
AIRFLOW
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
Reader contributions and correspondence
should be addressed to:
The Editor.
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Telephone (062) 68 6319
© Commonwealth of Australia 1988
ISSN 0045-1207
BB9/20570 Cat. No. 89 0558 2
Printed by Ambassador Press Pty Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
Editor:
Editorial Assistant:
Graphic Design:
Al Bridges
Karen Hutchison
Lesley Boulton
Photographs:P4, 12
PB
P14
P17
Al Bridges
Ron Israel
RAAF
BAS/
Diagrams:
P7, 12, 13 & 18 Peter Garfield
Cartoon:
P23
Gary Clarke
aving been invited to contribute an 'editorial statement' to this issue of the Aviation Safety Digest
and having joined the CAA as recently as 6 February I quickly concluded that the most useful contribution
I could make would be to devote my allocated space to
introducing myself. While it might not rate among the
more appealing items in the Digest. it is at least a matter of which I have some knowledge.
Just over a month ago I assumed office as Group General Manager, Safety Regulation . My predecessor in this
position was Mr R.C. (Jerry) O'Day - a man who is, I
am certain, extremely well known to the more seasoned
readers of the Digest as a most professional, colourful
and dedicated advocate of the science and practice of
aviation. I am indebted to Jerry for the very fine shape in
which he has handed-over the Safety Regulation Group.
Like Jerry's, mine is a military background. I spent a
little over 40 years in the RAAF where. in those days
when the opportunity presented itself, I flew as a Navigator on aircraft of types which today evoke emotions of
nostalgia and discomfort among the over-50s and polite
curiosity among the turbo-fan, titanium and ring-laser
community. Nevertheless , the past 20 years of my Air
Force career has been in positions (some more senior
than others) in and around the Department of Defence ,
which have called for management and marshaling of
often dissimilar interests towards achievement of a common objective. I suspect that experience will bear some
relevance to the regulatory process in which I am now
privileged to find myself.
Those readers who are familiar with the folk-lore will also
appreciate that, despite first appearances, assumption
of this office by a Navigator might not be entirely inappropriate. After all it might be said that I have , in one
way or another, spent most of my career looking after
pilots, protecting them from the elements, exotic distractions, and, more particularly, themselves.
Whether you are inclined to believe that or not, you may
be assured that my days of active navigation and my
more recent experience in what we tend, only half disparagingly, to term 'the bureaucracy ' have convinced
me that the successful conduct of any useful enterprise
invariably relies on the performance of its 'crew' in an
area that has come to be termed 'risk management'.
The connection between 'risk management' and 'safety'
is plain. Aviation, like motoring. like crossing the street
or even stepping out of the shower, involves some risk.
It is in the nation's interests that the aviation industry
should prosper. It is in the public's interests that while
we are all sharing in the fruits of national development,
we should not be placed at undue risk to life, limb or
wallet. It is Governments' responsibility to put in place
legislative and management arrangements that have
regard tor the well-being of all concerned and for our
position in the world arena. Somewhere in the midst of
those various objectives stands the regulatory process,
striking a sensible balance between the pursuit of absolute safety for the public and viability of the aviation
industry. It is a challenging prospect, but as readers will
know, is not one that we are any longer free to pursue
regardless of cost. We must look to our own business
strategy if we are to provide a service to Government,
Industry and the public that is marketable and
affordable in all three dimensions. In short we have an
omni-directional risk management problem.
I look forward to the challenge of that risk management
problem. I am sure it is one that we can and must
handle in partnership, and I look forward to working with
you - at whichever corner of this omni-directional you
happen to stand.
Editorial
t is surprising the various ways ice can get you. It can
build up on wings and tails almost imperceptibly; it can
be there in abundance almost within an instant. It can
break off and go down engine intakes. It can block engine
air inlets. It can form while the aircraft is still on the ground .
And it can choke carburettors.
Because Australia does not usually have the severe icing
conditions of many northern hemisphere countries, we are
often less experienced at recognising the symptoms and
dealing with the problem. To help us safely weather the
dangers of this winter, two articles on icing are included in
the Digest. A further article, 'Don't tell anyone', illustrates
the way in which concern for weather problems might well
mask more urgent concern for an aircraft problem.
With this edition we introduce a new section - NIL
DEFECTS. In this section will be items of interest to both
pilots and engineers. The item on replacement parts is of
particular interest to everyone involved in aviation. It invites
you to question the source of your replacement parts - the
supplier, the overhauler and the history of the part itself is it genuine, is it second-hand and has it been correctly
overhauled?
This Digest includes a poster covering the basics of GAAP
procedures. At about this time, too. the video 'Going To
Town' should be with your local Aero Club or Flying School.
Why not have a look at the video and fly a GAAP -you'll be
pleasantly surprised!
The Winter watchword - Whether. Whether to go or not to
go. Don't decide the day before that you will go. Look at the
weather on the day so that you can be confident of your
decision.
~~Al Bridges
Editor
7
Covers
Bell 2068. Photographic entry by G. Gunning.
Design by Kathy Walter. Production by
Soussanith Nokham.
Front: All at sea -
Back: GAAP poster -
�r
Aviation Safety Digest
141
Aviation Safety Digest
141
The incident
Pilot-induced
electrical failure
in controlled
airspace
Pilot contribution by Colin Field
HIS IS AN incident which occurred some
time ago on approach to Essendon Airport
_ and is a good example of the ways in which
multiple, unrelated factors can combine in
unexpected w ays to cause problems. In this
case, none of the dramatis personae were in
any real danger; however, the necessity to
hand-crank an undercarriage down was narrowly averted, and under the circumstances
that developed there was some fear that a
'wheels-up' landing would have to be carried
out, with the obvious increased potential
danger of such a course of action. If proper procedures had been carried out, none of the
events described below need have happened.
Three people set out in t he school's Piper PA-30
Twin Comanche for this purpose; a senior flying instructor as pilot-in-command, with two
individuals who 'went along for the ride' - a
student pilot in the right front seat, plus one of
the school's newly-qualified instructors in the
rear seat.
As the Cl 72 crew was anxious to embark on its
navex and return before last light, the PA-30
made a hasty takeoff and approach to Essendon
via Westgate Bridge and Flemington Racecourse. Essendon tower gave permission for a
straight-in approach on the duty runway. However, on final approach, transmission from the
tower became intermittent, and then ceased
completely; contact could not thereafter be
re-established. The pilot-in-command decided to
continue the approach, but when the t ime came
for undercarriage extension, he did not receive
green-light confirmation of this event. The aircraft had no choice but to execute a missed
approach and track back out of controlled airspace via Westgate, the three occupants keeping
nervous eyes out for any approaching traffic.
The pilot-in-command intended to fly back out
over Port Phillip Bay and deploy the
undercarriage manually, using the emergency
undercarriage hand-crank, or, failing this, to
perform a wheels-up landing at Moorabbin. He
instructed the student pilot, sitting in the righthand front seat, to unstow the hand-crank and
consult the instruction book on how to use it.
At that stage the student pilot, in the righthand seat, and directly in front of the fuel contents gauges, noted that both indicated empty .
He pointed this out to pilot-in-command, adding
that he knew the gauges could not be giving
accurate readings, as he had visually checked
fuel contents as part of his contribution to the
pre-flight inspection.
Background
The incident took place late one winter Sunday
afternoon. Our Moorabbin based Flying School/
Flying Club had several light singles available
for hire. Two members had hired a Cessna) 72,
and intended to perform a navex towards lhe
north. Their flight plan ~ncluded. a lan?ing at a.
Essendon, in order to ga111 experience m opera\ing in controlled airspace.
Several members and employees were lounging
at the School when an anguished telephone call
was received from Essendon. The Cl 72 had
landed without incident, had been parked on
the apron there for some time. However, when
it came time to depart, the two hapless aviators
discovered that their battery was flat, and as a
consequence they were stranded. Under these
circumstances the method of choice in starting
t he engine is to 'swing the prop'. As the two
crew were not experienced in this procedure
however, a senior flying instructor at our
school decided that it would be advisable to
mount a rescue party to Essendon.
0
N
-~-!L!C' O
*"'"t
PRIME R
ON
~(
5
-
A'llOt·JlCS
POWER
The p ilot -in-command concluded that the aircraft h ad s uffered an electrical failure which
h ad effected the radio, undercarriage and fuel
gauges. He instructed the student pilot to check
the circuit breakers, located under a panel in
the floor. The student pilot not ed that several
circuit-breakers had popped, and, under direction of the pilot-in-command, attempted to push
them back in. This could not be accomplished.
At this stage the pilot-in-command noticed that
the aircraft's magneto switches had been inadvertently left in the 'off' position prior to
takeoff. They were then switched on, and all
circuit breakers were successfully pushed in.
All electrical power was there aft er restored,
with radio communicat ion re-established, and
fuel gauges and undercarriage now operating.
The aircraft was turned around and tracked
once again to Essendon and the still-stranded
Cl 72. Subsequent approach and landing at
Essendon, prop-spinning of the Cl 72, and
return to Moorabbin were completed without
incident.
Conclusion
Magnetos had been left switched off prior to
takeoff from Moorabbin. As a consequence, all
electrical power for the aircraft was being
drawn from its battery. Hence, at a t ime of high
electrical drain (switching on the electricpowered hydraulic system for undercarriage
extension), the load on t h e battery was too
much, causing the intermittent and then complete failure of the radio, and the popping of
the radio and hydraulic system circuit breakers.
TAF: Terminal
aerodrome·
forecast
Analysis
Several factors combined to create a potentially
hazardous situation. These included:
l . Overconfidence on the part of the pilot-incommand, a senior flying instructor with several years experience, who was perhaps
over-anxious in wanting to demonstrate his
'prop-spinning' prowess.
2. Excessive haste used to get the Twin
Comanche into the air and over to Essendon.
The crew of the Cl 72 were anxious to get their
aircraft into the air and to complete the navex
before last light. However the Twin Comanche's
pilot-in-command should not have felt obliged
to apply haste in these circums tances , at the
expense of adequate preflight planning and
cabin checks.
3. Pilot-in-command's relative inexperience with
the aircraft type in which the incident
occurred. In the Twin Comanche, the magnetos
must be switched on using two toggle switches.
Most of his flying experience was in Cessna
singles, where magnetos are switched on with a
key; hence it is impossible to operate those aircraft without the magnetos being switched on.
4. Poor design of the Twin Comanche's electrical system, which allowed the aircraft to be
operated in a mode whereby only the battery
was supply ing current. This in itself is a neat
example of Murphy's Law, which dictates that
if a system can be operated incorrectly, it will be.
A timely reminder of the dangers of haste. I
wonder, if the rescue to Essendon had been in
haste but had been incident free and the haste
was an element present during the manual
prop swing ... ? D
code and breaking it into component groups, it
becomes easy to understand. The diagram below
shows the overall structure of the T AF and we
will examine eac;__~f the components.
TAF 1>r TAF AMO
Bureau of Meteorology
This ident ifies th e message. The term AMD
means,~e T AF R.as been amended ie there has
been a srgnificant change to part or parts of the
prev ious issue of the T AF for this aer odrome.
What is a TAF?
Place
1
"-
IMPLY A TAF is an AERODROME FORECAST, ie a statement of t he meteorological '
conditions expected for a specified period
in the airspace within five n autical miles of the
centre of the aerodrome or runway complex.
T AFs are presented in coded format so that the
format and contents can be standardised a nd
transmission is quick. By presenting the T AF in
The place to which the TAF refers is indicated
by either a four letter ICAO location indicator
(eg ASBK), the place name, or an approved
CAA abbreviation (eg SCN).
Period of validity
The first two number s indicate the commencement t ime in hours (UTC), and the last two t he
end of the period of validity (also in hours UTC) .
�TAF - AERODROME FORECAST
Aviation Safety Digest
141
8
2
1
Mean wind direction and speed of the
surface wind
The me an wind (ie the direction from w hich the
wind is coming) is given in degrees true to the
nearest 10 degrees and the speed is given in
knots; mean wind speeds are given in two figures eg 5KT is given as 05. Calm is given as
00000 and variable direction as VRBL. If the
maximum wind speed is expected to exceed the
mean by more than lOKT, then this is indicated
by a stroke followed by the strength of the
maximum wind or gust.
Visibility
This information (in metres) is always given in
a four figure group. It is given in increments of
100 metres up to 5 kilometres, and in
increments of 1000 metres from 5km to 9km.
The code group 9999 is used to forecast a visibility of lOkm or more.
Information on cloud covers the general cloud
dist r ibution of the various layers or masses.
The order is such t hat t he lowest cloud is given
first, the nex t higher b ase second and so on .
Cloud details are not given if CA VOK is used .
Cloud
The cloud information is given as a group(s) of
the form NCChhh, where N refers to the cloud
amount in eights, CC is the cloud type given as
a two letter abbreviation, viz
Cl
cirrus
CC
cirrocumulus
CS
cirostratus
AC
a ltocumulus
AS
altostratus
NS
nimbostratus
SC
stratocumulus
ST
stratus
CU
cumulus
CB
cumulonimbus
and hhh is the he ight of the cloud base above
the ae rodrome reference point given in hundred s of feet, using three figures eg 001
decodes as lOOft, 050 as 5000ft, 200 as
20000ft.
PLACE
Visibility, weather and cloud groups ar e
omitted if CAVOK is used.
Indicator of significant variatio.n
Because the weather can (and often does)
change there has to be provision for this in t he
TAF code. Reference to significant changes or
variations is made if changes or variations in
one or more of the e lement s wind (direction
and/or speed), visibility, weather or cloud ar e
expected. It should be noted that these apply to
improvements a s well as deteriorations.
Indicators of significant v ariation include:
TEMPO, which indicates a change(s) expected
to last for period(s ) of 30 minutes or more but
less than 60 minutes , but sufficiently
infrequently for the prevailing conditions to
remain those of the preceding part of the fore cast.
INTER, which indicates changes to occur frequently for period of less than 30 minutes in
each instance.
GRADU, which indicates a change forecast to
t ake place at an approximately constant rate
throughout the period.
RAPID, which indicates the change is forecast
to take p lace during a period lasting less than
30 minutes.
6
INTER
TIME
INDICATOR
GROUP
TEMPO
GRADU
r---~~r--;AVOK
10
VARIATION
RAPID
1 - - -- - - --1
WIND
7
CLOUD
-.,d,
11
L _ _ _ _ _J
r-~ r---~~ ,--~
l ___ J
VIS !-1WEATHERH CLOUD
L -_J L _ _ _ -J L _ _J
L
J
ANY OR ALL THESE ELEMENTS REPORTED AS NECESSARY
12
POSSIBILITY OF
POOR VISIBILITY
- -HAZARDOUS
- - - - -13.....
METEOROLOGI CAL
CONDITIONS
This is used to indicate the time per iod
throughout which t he ch ange is expect ed to
take place, t he first t wo numbers indica ting t he
commencement and t he last two the end.
Details of the change groups
These are formatted in t he same way as in t he
body of the T AF.
Possibility of poor visibility
When the occurrence of poor visibility, ie less
than the alternate minimum, during any part of
the forecast period is considered possible due to
the occurrence of fog, mist or dust, but the
PROBABILITY of such occurrence is assessed at
50 percent or less, t he form PROB (per cent) is
used.
Hazardous meteorological conditions
Special reference is made in TAF to hazardous
meteor ological conditions which may endanger
aircraft or adversely affect their safe operation.
These conditions ar e:
• Moderate or severe icing.
• Moderate or sev ere tur bulence, marked mountain waves.
• Severe line squall.
• Vertical wind shear.
Air temperature
Temperature information (in degrees Celsius) is
given for certain aerodromes u sing two figu res.
Values below zero degrees are preceded by MS
(minus) .
The information following the change or v ariation groups gives s ignificant changes or variations in the elements wind dire ction and/ or
speed , visibility, weather and cloud. Reference
to one or more of the elements is omitted when
no significant change or variation is expected in
the element concerned.
QNH altimeter setting
14
t - - ---t
Time group
These change and variation groups (TEMPO,
INTER, GRADU, RAPID) are not introduced
until all information necessary to describe the
elements wind, visibility, weather and cloud
have been given.
It is important t o rea d the whole TAF, not just
the INTER or TEMPO variation, a s in fact the
conditions in the body of the T AF may be
worse than that indicated by the v ariation.
WIND
WEATHER
CAVOK
This term is used when the following conditions
are forecast to occur simultaneously:
(i) visibility lOkm or more
(ii) no cloud below 5000ft, or below the
highest minimum sector altitude, w hichever is the higher, and no cumulonimbus
(iii) no pr ecipitation, thunderstorm, shallow
fog, fog patches, fog at a distan ce, low
drifting snow or dust devils.
CAVOK
PERIOD OF
VALIDITY
9
Weather
The weather is presented as a group consisting
of two figures and a series of letters; the two
figures are of interest to meteorological personnel only, and you need only be concerned with
the letter group. The groups you are likely to
see are:
FU
smoke
HZ
dust haze
PO
dust devils
BR
mist
FG
fog
MIFG
shallow fog
BCFG
fog patches
DZ
drizzle
RA
rain
SH
showers
SN
snow
GR
hail
SA
sandstorm or duststorm
TS
thunderstorm
The qualifier XX means heavy. The above
groups may be combined, eg RASH rain
showers, XXTSGR heavy thunderstorm with ha il.
TAF OR
TAF AMD.
3
QNH is given as a w hole number of
hectopascals.
Forecasts of a ir temperatu?e and QNH ar e given
at three hourly intervals for a maximum of nine
hours. The forecast va lues relate to t he commencement of the TAF validity, and subsequent
three hour intervals. If you are planning to
arrive at an aerodrome at a time between t h e
time at which the v alues are given , then you
should interpolate to find the value at your
AIR
TEMP
15
QNH
arrival t ime. On occas ions when TAF a re
amended there may be a t ime indicated after
the first temperature and QNH quoted - this
refe rs to the forecast conditions at that time,
and t he subsequent temperatures and QNHs are
for three hourly intervals from that time.
In conclusion, let us examine a T AF and see
what it means :
T AF ASSY 1818 00000 CAVOK
GRADU 2301 34018/ 30KT 9999 3CU040
RAPID 0709 18020/ 35KT 9999 80RASH 3ST009
5CU20
INTER 0410 MAX 45KT 3000 95TS 5ST010
4CB040
23 24 28 33 1012 1013 1014 1002
This is a forecast for Sydney a irport for the
p eriod 1800UTC to 1800UTC (24 hours). The
forecast is for calm wind and CAVOK condit ions initially.
Bet ween t he hours 2300UTC and OlOOUTC the
w ind is forecast to become 340 degrees true at
a mean speed of 18 knots w ith a maximum of
30 knots. Visibility w ill be lOkm or mor.e and
there will be t hree eights of Cumulus at 4000ft.
Between the h ours of 0700UTC and 0900UTC
t here will be a rapid chan ge whereby t he wind
will change to 180 degrees true at a mean of 20
knots with a maximum of 35 knots . Visibility
w ill be lOkm or more. There will be rain
showers with cloud of t hree eighths of Strat us
at 900ft and five eighths of Cumulus at 2000ft.
The re will be periods of less than 30 minutes
between the h our s of 0400UTC a nd lOOOUTC
when the w ind will gust to 4 5 knots, t he visibility will drop to 3000 met res and t here will be
t h understorms; cloud will be fiv e eighths of
Stratus at lOOOft and fou r eighths
Cumulonimbus a t 4000ft.
Th e forecast temperature and QNH at 1800UTC
is 23 d egrees and 1012 hectopascals; t he other
temperatures and QNHs apply t o t he times
2100UTC, 2400UTC and 0300UTC.
Th ere you h ave it . The T AF is t he weather
forecast for t he indicated place and t ime per iod,
formatted to t ell you t he forecast conditions
with any ch anges of a temporar y or lasting
nature D
�~
AviationSafety_
141
Don't tell
anyone
Pilot contribution by Peter Little
HE DAY started well, the weather in Sydney was fine and beaut, a typically great
winters day and the T AFs (Terminal Area
Forecasts) that I obtained over the phone for
my destinations of Glen Innes and Armidale,
whilst not as good as I had expected, were easily legal and no alternates were required.
The weather man (i.e. Met. Officer) confirmed
the earlier T AFs with little to add except that
the weather was expected to improve as the
day went on and he backed this up with the
satelite pictures showing a front clearing to the
North East and totally clear skies expected for
the afternoon. I filed my IFR flight plan happy
in the knowledge that whatever little weather
there was would clear as the day progressed.
Having completed my pre-flight inspection I
loaded my three passengers and departed
Bankstown at 10.06 am local time p lanning to
land at Glen Innes at 12 Noon and after some
local inspections departing Glen Innes at 2.45
pm stopping at Armidale for fuel, and arriving
back at Bankstown at 5.30 pm.
I climbed out of Sydney to 12 OOO feet in my
pressurised single engine aircraft on a 29 West
Maitland 1 departure which took me to the 002
radial north and gave my passengers the most
beautiful view of the Sydney Harbour, the City
and North Sydney. As I reached my cruising
altitude, now established on the 002 radial, I
went to throttle back to cruise power only to
discover I was already at cruise power. How
Piper Malibu over St Huberrs Island, Brisbane Water.
Aviation Safety Digest
141
did that happen? I instinct ively checked all the
other gauges and everything was in order
except the cabin pressure which was showing
7000 feet when it should have been showing
6000 feet. Not enough difference to worry
about. It had been nearly a month since I had
flown, mainly due to bad weather at my
intended destinations, and I concluded that I
had inadvertently set cruise power for the
climb instead of climb power.
Just the same I watched the gauges more than
usual for the next 30 minutes but all remained
normal. My attention was soon diverted by a
large cloud mass north of the Hunter 8/8ths at
around 6000 feet and an even larger mass in
the distance rising to 15 OOO to 20 OOO ft. The
forecast was for broken Strato Cu but there
was nothing broken about this. I had enough
fuel to get to Armidale and return to
Bankstown with my reserves intact and since I
was enjoying the flying I decided to push on
and see what eventuated. I did take a look in
the direction of Tamworth which looked doubtful but I knew Cessnock and Aero Pelican were
clear.
Approaching Armidale, a few small breaks
appeared in the cloud, although Armidale was
completely covered. There was a large hole to
the West with broken cloud beyond that, so I
assumed that since the front was clearing to the
North East Armidale would become clear later
on. In front was different and I was faced with
a wall of cloud up to 15 or 20 OOO feet. I
plunged on into the cloud noting the outside
temperature was -4 degrees C, my aircraft is
fitted with de-icing equipment but I prefer to
avoid it if possible. I therefore commenced my
decent into Glen Innes in dense cloud and later
heavy rain and emerged below the cloud right
on the lowest safe. I landed at Glen Innes in
heavy rain but with ample visibility.
Whilst in Glen Innes the weather cleared a little
but on returning to the airport it had once
again closed in. Having completed my checks
and engine run up (all of these were normal), I
taxied out and commenced my ground roll after
applying full throttle. I soon noticed that the
manifold pressure gauge did not read full boost
and in fact was indicating climb power only. All
else was normal including the apparent acceleration so I presumed a faulty gauge. However,
despite the fact that I was now at rotation
speed, I aborted the takeoff. As there were no
other aircraft in the area, I ran it up going the
wrong way down the strip and could find no
fault except the lack of full boost on manifold
pressure. As I had found no lack of performance on my first takeoff attempt and there are
no service organisations in Glen Innes, I decided
to try a take off, conscious that I could easily
abort if necessary.
The takeoff was normal but once in climb the
rate of climb was barely 500 feet per minute
and the MPG still showed climb power only at
full throttle. I was so absorbed in watching the
gauges I had climbed several thousand feet
before I looked out the window and realised
that I had forgotten to retract the
undercarriage and flaps. Once this was done the
climb speed became normal and I was now in
thick cloud climbing to my cruise altitude to
Armidale of 7500 ft. Now I noticed the MPG
dropping as if the engine wasn't turbocharged
and by the time I reached cruising had in fact
dropped to cruise power with full throttle. Also
the cabin pressure was 5000 ft instead of 3500
ft. I pondered on the probable cause deciding
that the MPG was in fact working, so was it the
turbo charge? Had I accidentally left one of the
plugs in the air vents and blocked the air flow?
I decided it was most likely the turbo charger
and then became racked with doubt. Was it
dangerous? Should I have taken off?
By now I was 10 minutes out of Armidale in
thick cloud and about to descend to Area Minimum Altitude when Coffs Harbour announced
that they had an amended T AF for Armidale
which now required an alternate. I was told the
Fokker had got in an hour ago so I decided to
give it a go. Remembering the trip up I nominated Tamworth as an alternate and after some
considerable delay was informed that
Tamworth would be acceptable. My entire concentration was then taken up in the NDB
approach and to my surprise broke visual right
on the minima of 4500 ft. There was a nasty
cross wind on the main strip and everything
was soaking wet but the landing was
uneventful.
Having refueled I checked to make sure none of
the air vents were plugged. Without removing
the covers, as I did not want to frighten my
passengers, I inspected as much of the engine
and turbo charger as possible but could find
nothing wrong. I was pondering on what to do,
whether to leave the aircraft in Armidale and
have it seen to or to fly it back to Bankstown
when one of my passengers, all of whom were
unaware of any problem, came across to me and
said 'Lets get out of here as quickly as possible,
I'm freezing to death'. That was it, I loaded
everyone and again found no indication of any
fault during my checks and engine run up.
The takeoff was again normal and because I
remembered this time to retract the gear, climb
was also normal except that the manifold pressure kept dropping. By the time I reached cruising altitude of 11 OOO ft, the manifold pressure
was two inches below normal full throttle
cruise. I checked the fuel flow which was normal and I had plenty of fuel, however the cabin
pressure was low again at 7000 ft. We were
now cruising above 8/8ths of cloud and having
satisfied myself that all the gauges were OK
and nothing was altering I began worrying had
I done the right thing. What if the turbo
charger seized? Was I taking an unnecessary
risk? Was I risking my passengers? I looked
around for emergency landing areas and calculated distances to airports gliding from 11 OOO
ft. I noted holes in the cloud and above all
watched the gauges.
1 was somewhat relieved passing Singleton as
the cloud was breaking up and I could see
Cessnock and by the time I reached Parramatta
I was in clear skies.
After landing, I refueled and put the aircraft
away and an inspection by the engineers the
next day revealed as I now expected, a clamp
on one of the turbo charger hoses had come
loose and once tightened the engine now
boosted normally. I reflected on the number of
flights where nothing goes wrong and that the
actual weather is usually better than forecast
and then on the number of varied events that
had happened to me in one day but I couldn't
tell anyone about it could I? I was pleased with
my performance although I realised at times I
was using all my concentration but don't tell
anyone - might not get anyone to fly with me!!
Pressure. Single pilot !FR operations have
enough built-in pressures without voluntarily
adding to them. Well, that's easy to say! Part of
those built in pressures are getting the job done
- customer satisfaction. It is a most important
pressure if you are to stay employed.
Then along comes a problem, the unplanned,
uninvited extra pressure. In this case the extra
pressure was applied very slowly through the
turbo charger clamp. The pressure was at
maximum before departure from Armidale an obvious aircraft problem, lousy weather and
the passengers giving the hurry-on.
What would you have done? Perhaps a phone
call from Glen Innes may have solved the problem. Discussions with someone, particularly the
boss, will share the pressure and help you to
make the correct decision. Perhaps the passengers would not have been so keen to pressure a
departure from Armidale if they had known of
a problem.
This pilot did what many of us would do push on. He shared the story of these pressures
with us so that we might recognise extra pressures building against ourselves and take corrective action 0
�r
Aviation Safety Diges
141
viation Safety Digest
141
If we lay the legal side apart, however, and
What goes
up ... !
UTSIDE controlled airspace, when must
you report your intention to change level?
1. Cruising at or above 5000ft.
2. Cruising below 5000ft and you intend to
climb to 5000ft or above.
3. Having notified FS of a specific cruising
level below 5000ft, you intend to change to
another level or operate at non-specific
levels below 5000ft.
4. Cruising non-quadrantal below 5000ft.
5. Cruising non-quadrantal above 5000ft in
IMC.
We can all go to the references and dig out the
answers. But, in flight these are some of the
things we need to know 'off the top of our
head' . Weather often forces an unplanned
change in level and other considerations - a
passenger request, for example - might also
result irl these changes.
But the real question is when should you report
your intention to change levels? This puts it
back onto you, the pilot, whose level of professional pride as a pilot should ensure a very
high degree of sound airmanship.
The regulations require a report for each of one
to three in the opening paragraph. Four and
five are answered in one to three. If you are
cruising non-quadrantal at 3000ft and have not
told Flight Service your level, there is no legal
requirement to advise a change of level remaining below 5000ft. The fifth situation is covered
in the first; you are above 5000ft and must
legally notify a change of level irrespective of
IMC or VMC.
look at cruising levels and level changes from
the good airmanship perspective, we might feel
professionally pressured to report all levels and
level changes. The hint is in item three; 'Having
notified FS .. .'
OCTA B 5000 can mean to some pilots open
slather. Obviously aircraft can be expected at
any altitude in training areas and around airfields. But OCT A B 5000 should not be treated
in the same way. After all, the only difference
below 5000ft to above 5000ft is the larger volume of air traffic below 5000ft. Therefore, the
more reason for flying at quadrantal levels and
telling Flight Service of intention to change
levels. Flight Service will then give you conflicting traffic about which the operator is
aware. The more of us who report our level and
request traffic for change of level, the more
Flight Service can help us not to run into each
other.
When OCT A below 5000ft there is no legal
requirement to tell anyone what le"'.el you are
at. Airmanship, professionalism, common sense
even, but particularly safety demands you fly
quadrantal whenever possible, tell Flight Service your altitude and advise before changing
altitude.
What if the weather is a bit off putting? Of
course if you intend VFR operations you must
stay 500ft below the cloud and 1500ft above
towns so you might have to try different altitudes. Tell Flight Service. 'For weather reasons,
I will be operating between 2000ft and 4000ft',
and tell Flight Service again when you select a
new - hopefully, quadrantal - cruising level.
Its not only those below 5000ft who can be
guilty of transgressing the laws of airmanship.
RPT do it, too. One big jet flew right across
Australia at the wrong level while another,
again at the wrong level, had half a dozen Air
Force jets pass in the opposite direction, same
level, while all were in IMC.
Over a five month period in mid 1988, seven
known incidents were recorded of IFR aircraft
within 200 miles of Sydney changing level without informing Flight Service. This is alarming; it
could be me who is killed by such unthinking
behaviour. All the advise is to notify Flight Service two minutes before changing level. This
gives Flight Service time to check other traffic
for you.
We had to wait awhile for the maintenance people to build up
some sand bags to land on. Just on the right side. That's the
only skid that was gone. The skid? Well, you see there was this
two and a half tanner that came over the crest of this hill the
same time we did, but in the oppositie direction. No, we didn't
report a midair. You couldn't have a midair with a truck, could
you?
Extract from accident report
'No known traffic.' What do you think when
you hear that from Flight Service? Do you put
traffic out of your mind or do you wonder
about that word 'known'? 'Known' rings alarm
bells every time for me. Look what we have
talked about so far and we haven't even considered those who don't say a word to Flight
Service.
Two more real life examples may convince you
to tell everyone what level you are cruising at
and what level you intend to change to.
A twin commuter was cleared on the 062
degrees localiser to Sydney at 6000ft. This aircraft had a near miss with another twin, supposedly tracking from Bankstown to Deniliquin
via Shelleys on climb to 8000ft OCTA. However,
due to thunderstorms, the outbound aircraft
diverted north-west of track and climbed to
6000ft, the lower level of the CTA, without
advising Flight Service or requesting a
clearance.
This example shows the hazards involved in
operating near controlled areas and not being
altitude aware. There have been recent incidents of aircraft straying out of the light aircraft lane into Bankstown from the north and
getting perilously close to the big jets. Certainly, these examples include a large element
of not being where you are supposed to be. But
if you are not where you are supposed to be the
chances are, especially in controlled airspace,
you will not be at the correct altitude for your
track and position. Those of you who operate
near our busiest airports, do you know what
the bottom limit of the CTA is and do you know
why? The ILS glideslope to some runways can
put some very big aircraft very close to the bottom of the CTA. If you think you have strayed
into CT A, tell someone and keep your eyes open.
A final example covers the OCTA above 5000ft
area, irrespective of VMC or IMC. A commuter
was cruising non-quadrantal after departing
Cowra for Sydney. A charter from Melbourne to
Bathurst reported Cowra, cruising quadrantal
and the same level as the commuter. A passenger in the commuter (which had 13 souls on
board) pointed out the charter to the pilot. The
aircraft passed very close.
The charter aircraft was at the right altitude
but was 20 miles abeam Cowra, not overhead
Cowra as reported. The commuter had advised
FS cruising non-quadrantal. One pilot took a
risk on the altitude; the other on position. Bot h
these decisions were deliberate. The result was
almost disastrous.
Perusing a list of occurrences involving change
of altitude without notification provides some
food for thought. Penetration of CTA is a regular with unfamiliarity with boundaries the
most likely cause. This could result in a particularly nasty accident like the DC-9 and PA-28
over Los Angeles in 1986 (next ASD will have
more on this accident).
Distractions while climbing or, even, in the
cruise and inadvertently climbing add to the list
of busted altitudes. Distractions may be caused
by the weather - rain, cloud or turbulence or
problems such as engine trouble and the
demands of test flying or training. '
Training. It is a distracting passtime. Not just
for the instructor, too. The student pilot doing a
solo in the local training area may well have his
hands full while still gaining experience. How
close do you fly to training areas? Its worth
giving them a wide berth, both above and to the
sides.
Other reasons given for changing altitude without notice include forgetting to say anything,
misunderstanding a clearance and letting the
passenger work the radio, resulting in misunderstanding between pilot and passenger.
The worst incident was a lie. The aircraft was
involved in a parachute jump and the pilot
reported operating below 5000ft. Another aircraft at 5500ft had to take evasive action to
avoid the para jump aircraft.
Thorough preflight planning is really the
answer to all this. It is very satisfying to have
ATC accept your flight plan with no changes
and for you to fly it as planned. I always urge
the submission of a flight plan as it imposes
professional discipline on the pilot, as it can be
a satisfying extension of the flight and as it
provides added safety. Not just safety because
of full reporting, either, but also because of the
preflight planning you must do.
Even if you do not intend going full reporting,
spend some time on the charts becoming familiar with the different types of airspace you
will be flying through or near, and the limits of
that airspace. Plan your own altitude accordingly, noting where you must climb or descend,
taking into account not only CTAs but also
quadrantal levels and lanes of entry.
The planning stage must include the latest
weather. The forecast can be spot-on, sometimes it is not, particularly area forecasts predicting cloud levels. If a VFR flight, you should
plan a level clear of forecast cloud. If, in flight,
the cloud does not live up to the forecast, you
can always cruise at a different level.
Always talk to Flight Service. Tell them your
level and, two minutes before you wish to
change, ask them for traffic. That way Flight
Service can prevent a nasty coming together.
And that's what altitude reporting is all about
- not coming together. With the ever increasing number of flying objects in our skies, it
takes only one pilot to ignore basic airmanship
for the evening news to show pictures of two
smoking holes in the ground D
�If you are not eligible for a free issue, or if you would like additional copies of t he Digest:-
Since th e introduction of t he FDP compatible
flight plan form, many errors h ave been noted
that would not only prevent automatic processing, but could also contr ibute to air safet y
incidents .
To assist pilots in correct ing these errors, a
series of incorrect flight plans will be shown in
successive Aviation S afety Digests, to challenge
and test pilot ability to detect planning and
operational errors.
Spot the mistakes in th e plan below and check
your results on page 13 .
Flight plans
\Ji
ithin the CAA planning is well advan ced
toward the introduction of automated systerns for the processing of flight plan
infor mation. The project is par t of the
Authority's commitment to reduce costs.
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Digest has been an integral part of
Australian aviation .
In July 1986, responsibility for the Digest was
transferred from the Bureau of Air Safety
Investigation to the Flight Standard s Division of
the then Australian Department of Aviation
(now CAA). This move reflected the perception
that civil aviation may have reached the limit of
accident prevention through regulation and
that the way forward is through increased
emphasis on safety education in general, and
the 'human factor' in particular. Rather than
just d raw lessons from accident investigations,
the Digest will increasingly seek to influence
pilot behaviour by positive reinforcemen t of
sound techniques. It will examine all aspects of
piloting and publish formal results as well as
'the tricks of the trade'. The 'crash comic' will
become a 'how not to crash ' comic.
Anyone with an interest in aviation will benefit
from tapping into this un ique source of the
accumulated wisdom of the profession and
the latest research into aviation safety in
Australia. Indeed, anyone with an interest in
high technology and the roles and limitations
of the human operator will find this publication en lightening .
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The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to: AIRFLOW
Aviation Safety Digest
P.O. Box 367
CANBERRA A.C.T. 2601
Australia
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S1od.No. 1680U
Aviation Safety Digest 141 / i
�Safety contacts
Accident response
Safety promotion liaison officers
Bell 206B Jet Ranger II, 23 May 1987
Following a series of engine chip warning lights, the engine failed due to engine bearing failure. The
helicopter autorotated into trees and was destroyed by fire.
Central Office
Steve Tizzard
Safety Regulation Group
Civil Aviation Authority
GPO Box 367
CANBERRA CITY ACT 2601
FACSIMILE: 062 485239
NSW
John McQueen/Mary O'Brien
Safety Regulation
Civil Aviation Authority
P.O. Box 409
HAYMARKET NSW 2000
VIC/TAS
Mark Perrett
Safety Regulation
Civil Aviation Authority
G.P.O. Box l 733P
MELBOURNE VIC 3001
Telephone
062 68 4918
02 2187111
03 6622455
QLD
Bill Taylor
Safety Regulation
Civil Aviation Authority
P.O. Box 10023
Adelaide Street
BRISBANE QLD 4000
SA/NT
Ian Smith
Safety Regulation
Civil Aviation Authority
G.P.O. Box 2270
ADELAIDE SA 5001
WA
Lesley Smithers
Safety Regulation
Civil Aviation Authority
G.P.O. Box X2212
PERTH WA 6001
07 8336211
CAA action
This accident will be the subject of an article which will stress the importance of following procedures.
08 2180211
09 3236611
These are conducted in association with the Aircraft Owners and Pilots Association. The program
for the remainder of 1989 is as follows:
July 29
Perth
August 26
Dubbo
September 23
Rockhampton
October 21
Mount Gambier
November 25
Moorabbin
The above dates are provisional, and accurate at time of printing. Final dates, themes and venue
details are published in the AOPA monthly Journal in the months preceding the event.
24 hour contact numbers for BASI offices:
Canberra
Adelaide
Brisbane
Melbourne
Perth
Sydney
(008) 02
(08) 218
(07) 835
(03) 663
(09) 378
(02) 281
0616 or (062) 57 4150
0579
3676
7015
1333
3120
Cessna 206U, 27 May 1988
In flight, the pilot discovered that throttle movement was restricted to 18 to 23 inches MAP. On
advice of the company chief pilot, mixture was closed at 300 to 400 feet on finals to Kununurra.
The aircraft then landed short and struck a ditch.
BAS! r13commendation
The Aviation Safety Digest should publish an article showing the correct and incorrect procedures
used in this accident and the presentation of external advice to pilots who are under stress.
Pilot Safety Awareness Seminars
BASI contacts
BAS! recommendation
The Aviation Safety Digest should publish an article stressing the importance of adhering to engine
manufacturer's maintenance procedures.
CAA action
The accident has lessons for us all and will be the subject of a future article.
Partenavia P68-B, 14 October 1988
The aircraft crashed while attempting to land at an 850 metre long ALA, illuminated by two
vehicles' headlights. It was a moonless night and the ALA does not meet the requirements for night
operations.
BAS! recommendation
The Aviation Safety Digest should publish the requirements for night ALA operations and the
dangers of night VFR flight.
CAA action
Although night VFR operations have been covered many times before, a short, descriptive article
will be prepared as a guide for p ilots.
Robinson R22-Beta, 2 November 1988
The pilot commenced mustering at about 5 am and flew for three hours. For the next seven hours
he completed routine station duties in temperatures near 40 degrees C. After about 20 minutes into
the second flight he decided to land for a drink of water. On landing, the tail rotor hit a small
sapling, the assembly separated from the helicopter and the pilot landed after two revolutions.
BAS! recommendation
The Aviation Safety Digest should remind pilots of the insidious effects of heat stress.
CAA action
The Digest regularly publishes articles on heat stress (e.g. ASD 110) and duty hours, including
letters in Airflow. This topic will be revisited in the Summer edition.
CAIR.office contact (office hours)
Canberra
(008) 02 0505
vi /Aviation Safety Digest 141
Aviation Safety Digest 141 / vii
�Aviation Safety Digest
141
AERONAUTICAL INFORMATION SERVICE AUSTRALIA
7. Failure to nominate reporting points is probably the most common error detected by briefing officers. Reporting points are easy to forget
when producing your flight plan, but are essential for Flight Data Processing. DO NOT use
triangles.
NOTICE
CURRENT DOCUMENTATION & PLANNED NEXT ISSUE
Current Issue
Document
It
Planned Next Issue
8 . 'TMB' is not an approved abbreviation.
T AMBO is the correct abbreviation for Tambo
Crossing. If you don't know the abbreviation,
do not guess it, research it or write the location
out in full.
#
· ~
29.06.89
DAP(E)
DAP(W)
01.06.89
24.08.89
27.07.89
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Aerodrome Diagrams
01.06.89
27.07.89
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04.05.89
24.08.89
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.......••• .
.....
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04.05 89
11. Navigation aid training Cooma (CM). The
pilot should have inserted 'AREA' not 'A WK' in
the Route/ Segment/PFR section of the plan
with NAT/CM NDB in the OTHER INFORMATION portion of the plan. (Rac/Ops-1-21 and
Rac/Ops-1-22A, VFG 44-8 and VFG 44-11)
,_
I
24.08.89
I
U.-
VFG (book)
04.05.89
24.08.89
A IP/MAP
29.06.89
14.12.89
VFG/MAP
29.06.89
14.12.89
DAH
29.06.89
14.12.89
fL I
FLI -&K
I
I
14. There is a requirement for charter operators
to carry first aid kits. (CAO 20.11 para 4.1)
1. IFR Category, passenger carrying charter
operations using single engine aircraft are not
permitted. (Rac/ Ops-0-13 3 .3.2)
15. There is a requirement for aircraft to carry
life jackets on overwater flights and for each
occupant of the aircraft to wear a life jacket
during t he flight over water. (Rac/Ops-1-49,
CAO 20.11 para 5.1)
And how did you score?
3. Mode C SSR equipment is now required for
operations within cont rolled airspace at Sydney. (Class 2 NOTAM CO 2/1988)
dates quoted are effective dates
Note: CLASST & CLASS
12. Fuel endurance is a must and TBA is not
acceptable. If you don't know what your endurance will be from a location, calculate and
insert a 'Fuel Req'd' figure.
13. When nominating an endurance from a
location there is no need to show it as a
'FROM-TO' as shown; ie BK-FLI
2. When circling navigation aids do not
encompass both the number and the letter. Only
the letters are used in FDP.
It
10. There is no requirement to'DITTO' or to
repeat the same information down columns; eg
levels.
IL
i-1
-1
1-1
ic
AIP (book)
9. There is no requirement to show climb or
descent arrows.
4. Pilot has not indicated an ETD for Flinders
Island. Where an ETD is not accurately known,
insert the earliest likely departure time. Fa ilure
to insert ETD will result in the flight plan being
rejected by FDP. (Ra c/ Ops-1-21, VFG 44-8)
TT NOTAM ARE TO BE CONSULTED
WHEN USING ANY OF THE ABOVE DOCUMENTS
ISSUE: 6
DATE: 29 JUNE 89
Amendments to flight planning procedures were
promulgated to the Aviation Industry in 1987
as AIC CO 17, and the flight plan forms currently in use a re compatible with Flight Data
Processing (FDP) equipment.
FDP equipment will automatically supply Air
Traffic Service officers with the information
necessary to provide services to aircraft, both
within and outside controlled airspace.
5. The departure point, ETDs and landing
points are not correctly inserted . There should
be no space between the departure/landing
points and the ETD, and the departure point
information is separated from landing poin t
information by a dash; ie, ASBK0700-FLI0930ASBK. (Rac/ Ops-1-21 , VFG 44-8)
Pilots have an important role to play, for when
th ey complete their Flight Plan in the correct
format, they ensure th e plan's rapid processing
by CAA staff.
6. The aircraft arrives at Flinders Island after
last light. Lighting at Flinders Island is available for emergency use only. (ERSA)
Detailed instructions for the completion of
flight plans are contained in AIP, VFG and as
part of the flight plan pad D
viii/ Aviation Safety Digest 141
I
t
�Aviation Safety Digest
, Aviation Safety Digest
141
141
Engine icing
Bureau of Meteorology
N A RECENT edition of the Aviation Safety
Digest, an article on airframe icing
highlighted important aspects to consider in
both flight planning and flight stages, to prepare a pilot for possible icing conditions.
Engine icing can be another form of aircraft
icing. Like airframe icing, engine icing is a
major cumulative hazard to flight operations. If
left unchecked, it can choke the engine's induction system until sufficient power to maintain
flight is no longer available.
Engine or carburettor icing can be a frequent
hazard to piston engined aircraft. Fortunately,
nearly all such aircraft have carburettor
heaters to prevent this problem. There can be a
15 to 20 degree C temperature drop between
the outside air intake to the coldest part of the
carburettor. Carburettor icing can be avoided
providing the pilot recognizes the conditions
conducive to it.
The cooling effect of fuel vaporization together
with the expansion of air as it goes through the
carburettor can result in a large temperature
drop sufficient enough to freeze the moisture in
the incoming air. Of th e two cooling processes,
vaporization of fuel causes the greater temperature drop. Ice can form in the carburettor
usually at small throttle openings around the
butterfly opening and in the area where the
fuel is mixed with the air.
Ice may form at any time of the year and under
a wide range of atmospheric conditions, regardless of whether the aircraft is being flown in
cloud, precipitation or clear air - provided
that the incoming air has the proper moisture
content and temperature.
If the relative humidity of the outside air being
drawn into the carburettor is high, ice can form
inside the carburettor with a temperature as
high as 25 degree C. It is most serious when the
temperature and the dewpoint approach 20
degree C.
The carburett or heater is an a nti-icing device
which preheats t he air before it reaches the
carburettor, melting any ice entering the intake
and keeping the mixture above the freezing
point. The heater is usu ally adequate to prevent
icing, but will not alwa ys clear out ice which
has already formed .
Therefore if engine icing is suspected with
symptoms being rough running and loss of
power, the pilot's immediate action should be to
select full carburettor heat. The melting of ice
inside the induction passages may initially
result in the engine running rougher, but the
temptation to return to cold air should be
resisted and the hot air be allowed time to clear
the ice.
Points to remember
These are some worthwhile points to remember
concerning icing conditions in general:
-
During your meteorological briefing, check
for possible icing areas. Take the opportunity to check AIREPS in the area of your
planned route.
If your aircraft is not equipped with deicing
or anti-icing equipment, avoid areas of
known icing.
-
Use your deicing and/ or anti-icing equipment during situations of light icing; but
when such equipment becomes less effective, immediately change altitude and/ or
course rapidly to take your aircraft clear of
icing areas as soon as possible.
Remember that the meteorological briefer and
other people on the ground have no way of
observing actual icing conditions. Be considerate of your fellow pilots, file an AIREP if icing
conditions are encountered 0
DC3 in icing conditions.
Ice
yet
another way to
get you
by Ben Schiemer, Examiner of Airmen, Civil Aviation Authority
RACK AND heading 093 to Noojee, lowest
safe 6200: wild, beautiful tiger country
below. A package of aviation history to fly,
enough cloud to make flying interesting and a
red-hot pot-bellied stove waiting in the crewroom at Sale. We could only feel guilty for collecting our pay.
But the C47 has no radar (can you imagine
Indiana Jones needing radar?) . Suddenly it was
very dark except for the white stuff rushing in
waves at us, and the throb of engines was overlaid by the slashing of cold rain and ice.
Turbulence no problem for such handsome daredevil pilots, height holding O.K. Power reset for
turbulence penetration speed. Jeez - look at
that ice build-up on the windscreen: wing boots
on cycle, heaters checked on, gills fully closed,
carb air hot.
Carb air hot! The levers are stuck fast! Look at
that build-up in the ram air intakes - it's
blocking the rotation of the doors! Those bloody
engines will die in a couple of minutes unless
we can turn the doors to HOT!
I heaved at the carburettor air controls with
increasing desperation, suddenly vividly aware
of the great trees on the steep slopes in the
cloud below. Fearful of breaking cables and
connections, I rammed the levers back and
forth to tear the intake doors free, my co-pilot
watching the struggle with increasing anguish,
the boost gauges edging down.
At last the air doors turned - first one, then
the other. The big radials purred on. I learned
about icing from that.
Most piston pilots know about carburettor icing,
but it is natural to associate it with cold, wet
conditions. Accident reports show some 18
identified (the evidence disappears) forced
landings due to carburettor icing in the last
four years. Many of the pilots involved may
have been expecting carburettor ice but failed
to use hot air properly (steady application of
hot air at the right time, not whacking it on and
off), others didn't remember that you can get
carby ice at ambient temperatures up to 25
degrees C if the humidity is in a critical range.
My problem with the C47 was impact ice. Carburettor ice was not a serious problem because
the PW1830 has an injector system that feeds
fuel into the supercharger after the venturi and
throttle butterfly. But the engine does,need a
lot of air and if the air intake is blocked by ice
(or anything else) then the big donk will soon
enough snuff it. And so will any other engine,
fuel injected, turbocharged, or whatever.
Impact icing will always occur when there is
visible ice on the rest of the aircraft. On the
C4 7 ice accretions could jam the air intake
doors in the ram position, because they have to
be rotated to go from Ram to Hot selection.
Designs differ of course. The Baron, for
instance, has air intake through a filter fed by
ram air. Should the air intake or filter become
blocked a spring-loaded, normally closed door
will open under suction to allow warm air from
around the engine to get to where it's needed.
Being thoughtful fellers, the Beech mob have
provided a breakout cable and handle just in
case a 'flash flood' of freezing water gets
through the filter and welds the alternate door
closed. All the pilot has to do is give the alternate air T-handle a firm tug to make sure the
flapper door is free.
Don't confuse this manoeuvre with selection of
carby heat on a carburettor engine! If you cycle
from Cold to Hot and back to Cold too quickly a
splash of hot air will be introduced to the
venturi: the most likely result would be sufficient melting of ice to smooth it into a rockhard base for further accumulations until the
venturi looks like one of those arterial vein diagrams the medical doom-dooms use to get us old
blokes off bacon-n-eggs. Roughly the same
result.
Remember that snow and slushy sleet - cold
crud - will stick in the intake under conditions
where such would slide gracefully off the
airframe, probably taking an aerial or two with
it. This is obvious when you consider that primary air intakes are designed to collect, hold
and direct air to the engine's gullet, be it
injected or carburetted. The slushy stuff will
tend to fill up your air intake/carburettor
rather like the mud that accumulates in the
wheel-wells of your Range-Rover, while it slides
despairingly off the glistening exterior.
So look at the system on your particular aircraft: look at the machine, not just the
handbooks, and talk to your favorite LAME
about it. If nothing else it will get you aware of
engine ice as a problem, leaving you less likely
to forget about it when the thunderclaps are
roaring. Remember that when the manufacturer
writes about his machine he has a vested interest in minimising the warts. That's why you
should look at the machine and talk to the
LAME, to see what you could do if the chips go
down.
�Aviation Safety Digest
141
That's all straight-forward enough. Or so it
would seem. It seems so straight-forward that
manufacturers, while putting carburettor icing
procedures up front in the checklists, often
mention intake icing for injected engines as
something of an aside.
And it shows because pilots sweat out roughrunning engines, drop into the bush, hills and
gullies, and occasionally cream themselves
because they didn't get around to selecting
alternate air (they were probably too busy flying on one, calling May-Day, or selecting a soft
spot, to go for alternate air).
So read your manual: it may tell you all about
it. But if it doesn't, remember that the aircraft
probably wasn't cleared for icing conditions and
there may therefore be little mention of what
you should do if you find yourself in it. Manufacturers have the privilege of expecting their
products to be used as directed, but real life
can find you suddenly projected into something
they didn't cater for (they might have recommended an FA18). So if the manual doesn't
say much about what to do if you suddenly ice
up, pray that you've gleaned what you can ...
or just pray.
Carburretor icing
Carburettor icing can grab you like a brown
bear when it's cold and dark and rainy. Or it
can creep up on you on a clear midsummer's
day. You must always cater for the possibility
of carburettor ice. And it is not just a matter of
using hot air any time you pull the throttle
back; hot air used in hot dry conditions may
boil off fuel in the carburettor and unbalance
the mixture enough to cause rough running or
engine failure. Or if you are descending on a
cool day you may have to keep the speed down
and the power up to get enough hot air to keep
carburettor icing at bay.
Bone up on the owner's manual, seek advice
from old hands, read all about it (the Manual of
Met. Aviation Supplement, ASD 132, pilot
licence theory texts; all have something to say).
Above all make it second nature, priority one,
to use carby heat correctly on a routine basis.
That way you won't find yourself too busy to
get around to carby heat one day, because you
didn't get around to it.
Impact icing
If your aircraft hasn't been cleared for flight
into icing conditions then you must try to stay
away from it. Prop ice and resulting imbalance,
frozen trims, higher stall speeds all occur, and
many components may not cope with the ice
loads and vibrations. The dying song of your
(expensive) HF aerial may well alert you to an
icing condition.
But if despite trying you do get caught out,
then go for alternate air as priority one to
ensure that induction icing doesn't make a hard
life even more difficult, confusing, or
impossible 0
Forced landing
after takeoff
fl ICHAEL Badge, in ASD 139, raised some
questions on forced landings. Other
_
articles, including Airflow, discuss early
considerations in a forced landing. Here, we
will look only at the engine failure in a single
engine aircraft soon after takeoff. First a reallife example.
The flight was planned as a single circuit for a
passenger joy ride. Runway 35 was used with
the wind 310 at 5 knots. At about 1.00 feet and
90 knots after takeoff the engine lost nearly all
power. Because he was just past the end of the
strip, the pilot turned left with the aim of landing back on the strip.
Witness' description of the flight path indicated
that the turn was almost completed when the
aircraft stalled and descended steeply, right
wing down, to ground impact. Both occupants
received severe spinal injuries and the aircraft
was badly damaged.
From early in the training sequence, pilots are
taught not to attempt a turn back through 180
degrees. Obviously, with a large airfield a turn
may require only 90 degrees. Such a
maneouvre, however, needs to be thought out
before the emergency.
With any wind, a turnback is even more hazardous . After the initial shock of engine failure,
the typical wide-eyed pilot will be frantically
looking outside for the best place to land. While
in the air - even as a glider - the aircraft
still has to be flown. During an emergency
turnback, the eye will subconsciously detect an
increased groundspeed as the turn continues
from into wind to downwind. This will be interpreted as an increased airspeed - the conscious mind is still working on where to land and result in back stick, reduced airspeed and,
eventually, stall.
I was amazed to witness this process once when
a small aircraft did an approved low pass. The
pass was done downwind, with about 20 knots
tail wind, but was planned to be as slow as
possible so that observers on the ground could
see the passengers. Why the pilot did the
flypast downwind I never understood. However,
his turn onto base for the second run was similar to a turn back following engine failure. The
pilot was looking outside to align the aircraft
for the next run and, about three quarters
through the base turn, the aircraft stalled,
crashed and burnt.
Before the takeoff, consider where to go if the
engine does stop. The aim is to get as slow,
without stalling, and as low as possible before
hitting anything, if obstructions cannot be
avoided. But you must stay in control. If the
aircraft stalls, you no longer have control, you
are along for the ride.
One important point should be made. If you fly
a twin (or more than one engine), your options
are much greater. Of course it is always possible that you have so overloaded the aircraft
that, following an engine failure, you a re forced
to land straight ahead anyway. Assuming, however, that you have checked the aircraft performance data you should be able to complete a
single engine circuit. An option always is some
type of procedure turn for landing in the
opposite direction but that is more likely to
cause more problems than the familiar circuit.
This point is important simply because some
people who have recently upgraded to twins or
who fly both single and twin engine aircraft do
forget about the second engine following an
engine failure and give themselves an unnecessary forced landing.
To finish, lets hear from a pilot who walked
away from an engine failure soon after takeoff.
Dear Sir,
Like Michael Badge, I have tried to keep my
forced landing procedures and skills up to the
mark with frequent practice and check flights
with instructors.
But when I recently experienced a REAL forced
landing, there was little opportunity to put my
training into actual practice.
You see it all happened below 300ft, and yet all
my training has been above this altitude.
When the engine of my Cherokee 140 decided to
internally self-destruct on takeoff at about
250ft, I had just crossed the upwind threshold.
My immediate thought was, 'Can I get back to
the field? No! There's the beach, that'll do me!'.
My instructors have always maintained that at
low altitude it's impossible to return to the
field, but I'm really not so sure. But it's not a
situation I can readily repeat just to find out.
After my experience, I can assure your readers
that a REAL engine failure is very different
from a simulated one with an instructor sitting
alongside.
Firstly, t he noise and the fumes. A conrod
thrashing around inside the crankcase made an
enormous din and that effected my ability to
think clearly. Oil fumes too, made me fearful of
fire.
Did I close the throttle? Yes, at least it was
quieter and the engine had lost most of its
power. Carby heat and F-MOST checks are not
much use when the engine is destroying itself.
May Day? Not a chance, and anyhow I was still
on the ALA frequency. Turn off switches and
mains? Did not give it a thought until on the
ground. Unlatch the door? No!
I only had time to tighten my seat belt, crank
on three stages of flap , slow the aircraft down
and settle onto the beach. I estimate there was
only 30-40 seconds between engine failure and
touchdown.
I was very, very lucky not only to survive but
to have a relatively un-damaged aircraft.
(Unfortunately some further damage was sustained in recovering the aircraft from the
beach.)
It's a situation I certainly do not want to
repeat, but it's also a situation that I wish
could be practiced in safety.
Yours faithfully ,
Chris Wilson 0
�Aviation Safety Digest
Aviation Safety Digest
141
141
A casual study of the diagram does not indicate
the potential dangers of ignoring the advice
given. After all it is only advisory hence its
usual placement in the Performance section of
the flight manual. For some types the diagram
appears in the Limitations section; but this is
not strictly correct as it is not a limitation on,
or prohibited area of, operations.
Enter at own
risk
The following discourse is intended to briefly
sumarise the requirements for HV diagrams, the
way they are dev eloped and the potential for
disaster of not only venturing into but, in some
circumstances, straying too close to boundaries.
by Keith Engelsman
NOT UNCOMMON sign at the entrance to
properties generally indicating the presence
of savage dogs, billy goats and other semidomesticated animals likely to present a risk to
life and limb. These signs are provided as a
friendly warning that you should either stay
out or, if you choose to continue, be aware of a
potential danger.
All helicopter flight manuals contain a similar
warning. It is called by many names: Limiting
height-speed envelope; A void area; and Dead
man's curve are just a few. The generally
accepted term is Height-velocity (HV) diagram
which, in itself, does not suggest anything hazardous. The fine print that accompanies the HV
diagram is normally a mild admonition to 'avoid
operation in the shaded area'. A typical HV diagram is at Figure 1.
HEIGHT VELOCITY DIAGRAM
500
AVOID OPERATION IN
SHADED AREA
UJ
~
~20
1:?:
Cl
iii
:?:
10
20
40
60
80
INDICATED AIRSPEED - KNOTS
100
Manufacturers do not produce HV diagrams out
of the goodness of their hearts. The suggestion
that their latest and greatest machine might
have some flight regimes that are less than perfect does not accord with the glossy brochure.
HV diagrams are produced because they are a
certification requirement. The actual regulation
states inter alia 'If there is any combination of
height and forward speed (including hover)
under which a safe landing cannot be made
under the applicable power failure condition ...
a limiting height-speed envelope must be established (including all pertinent information)for
that condition ... '
The applicable power condition referred to
means complete and sudden power loss on one
engine and the remaining engine(s), if you have
any, operating at maximum power. The regulation also requires the envelope to cover all
weights up to MTOW at altitudes up to at least
7000 ft.
HV diagram development is a very high risk,
and expensive operation. The manufacturer will
wish to produce t he smallest avoid area possible which in turn w ill r equire flight to the very
edge of the safe landing envelope. Unsafe landing will, by definition, result in some damage to
the aircraft; and possibly the crew and passengers. For these reasons, HV testing is normally
left until the end of the certification programme, the oldest development aircraft is used
and there is a certain amount of 'short straw
drawing' in the test pilots office.
Before commencing HV testing, the test pilot
will become totally familiar with the
autorotational characteristics of the aircraft.
This will include rotor decay rates, handling
qualities during transition from powered to
autorotative flight, optimum flare heights, attitudes and rates. The test aircraft will be instrumented to record critical parameters, notably
vertical and longitudinal accelerations, and
loaded to the correct weight. Supporting personnel, including fire and r escu e ser vices, will
be briefed on their part in the tests. The test
area will be surveyed to choose sites for ground
recording equipment and cameras. The cameras
are important for data recording purposes and
occasionally provide some sobering records of
what h appens when you step over the line.
The flying to develop the HV diagram will
involve dozens, and even hundreds, of data
points. The aircraft will be flown to its absolute
limits, with respect to vertical and horizontal
accelerations, in an attempt to establish the
smallest possible 'unsafe' areas. Occasionally
limits will be exceeded and there w ill be a
pause in the programme whilst the aircraft is
repaired; or replaced.
At the end of the programme the certification
authority will require the manufacturer to
prove the HV diagram. This process involves
spot checks of certain points along t he edge of
the avoid areas. It is carried out by an experienced test pilot after a comprehensive familiarisation with the aircraft and its autorotational
characteristics.
The net result, as shown in the flight manual is
the product of extensive testing and checking
but what does it mean for the average h elicopter pilot?
First and foremost is the fact that if you have
an engine failure whilst operating in the av oid
area you will damage the aircraft in the ensuing landing. The extent of damage will depend
on how far over the line you are and may result
in injury to you and your p assengers. For
example engine failure during a high hover taxi
('high' means greater than five feet in most
machines) will damage the undercarriage but
hopefully not much else; always a ssumin g you
eliminate yaw and drift before touchdown.
More dramatic is an engine failure whilst hovering at say 100 feet. A high speed run across
your mates property with the skids in the
w heat may be exhilarating but if the engine
stops you will be lucky if all that results is a
wrecked tail rotor as you try to flare off
ground speed; that's if you get a chance to flare
before impact.
Another feature of HV diagrams is that, unlike
other performance data in your flight manual,
there is no buffer or margin for error. They
have been developed by someone who is probably the best pilot in t hat particular machine.
Your chances of doing better are about the
same as winning Lotto. Hence, in all probability, an en gine failure in the 'safe' area, but
close to the line, will r esult in a crash. This has
been proven on several occas ions by
overzealous instructors seeking a more demanding emergency simulation for their students.
At the end of the day there are a few simple
rules for dealing w it h the HV diagram.
Rule 1
If at all possible, don't fly in the avoid areas :-
keep your hover and air taxi height as low as
possible (three to four feet is normally a mple);
is it really necessar y to hover at 200 feet to
t ake that picture? (Could you go higher or put
on 30 knots?). A void low passes as they allow
no room for error.
Rule 2
Don't take liberties with avoid area boundar ies :
you would be amazed if you knew how little
margin there is before the bottom drops out of
your world. Your insurance company will not
thank you for failed attempts to adv ance this
area of aviation research.
Rule 3
If you must operate in the avoid area, give
yourself the best chance of minimising injury in
the event of an engine failure :- seat in good
condition to absorb impact forces?; harness
t ight and secure?;how about a helmet on your
next sling load job?
To conclude, a few facts about commonly held
beliefs from HV diagrams.
'It only applies to maximum weight operations'
- Not so. Some parts of the avoid areas are
defined by p ilot reaction irrespective of weight.
The problem is you don't know where they are
and what margin, if any, exists for reduced v ertical velocities at lighter weights in other areas.
See Rule 2 before contemplating researching
this aspect.
'High hovers and air-taxi are safe in strongish
wind' - Only true in very strong (greater than
40 knots in the above diagram) winds and even
then t here is a complication. Remember t h e HV
diagram relates to IAS, but when t he engine
stops at say 100 feet and 40 KIAS, ground
speed becomes a major consideration. Construction of the HV diagram involved use of flare.
effects w herever possible. If airspeed equals
w indspeed then that flare effect is not available
- unless you w ish to touchdown going backwards . Think about this circumstance next time
you fly in strong winds and give yourself an
extra margin beyond t he avoid area limits.
'The high hover limit point ( 450 feet in the
above diagram) is the minimum h eight I s hould
fly downwind' - Not so. The HV diagram only
holds true for a landing in t he direction of
flight following power failure. Minimum recommended downwind height is dictated by the
autorotational performance and handling of the
particular aircraft type. There is no direct correlation between the two issues.
In summary, the HV diagram has been provided
to w arn you of a potential danger. If you must
operate in it, eg. sling load operations, then give
y ourself t he best chance of surviving the inevitable crash landing if the engine stops. If you
don't have to enter th e avoid area then don't ·
believe me, you don't need that sort of t hrill 'o
�Aviation Safety Digest
141
Aviation Safety Digest
141
Aviating with
Mogas
Maule
North American
OR THOSE aeroplane owners and/or operators who wish to use MOGAS in their aeroplane the following may be of interest:
Petersen Aviation Inc. is an American firm
which is the current holder of a large number
of U.S. supplemental type certificates (STCs)
covering the use of MOGAS in many piston
engine aircraft.
Recently Dr. Ray Hodges acting as the Australian agent for Petersen Aviation, applied to
the CAA (Australia) for Australian acceptance
of those STCs which cover the use of MOGAS in
the following aeroplanes:
Piper
Piper
Make
Model
Air Tractor
Ayres
AT-300, AT-30I
S-2C and 600 S-2C,
Serial Nos I I 63C &
600- I I 63C thru I 526C
or 600-I526C only
S-2R, S2R-RI320, 600
S2D
600-S2D, S-2R,
S2R-RI340
7GCAA, 7GCBC, 7 AC,
S7 AC, 7BCM, 7CCM,
7DC, S7DC, S7CCM,
7EC, S7EC, 7FC, 7GC,
7HC, 7GCA, 7JC, 7GCB,
7KC, 7GCBA and 7ECA
75(PT-I3), A75(PT-I3A,
I3B, I3C), B75(N2S-2),
E75(PT-I3D, NS2-5, PTI3D/N2S-5),
A75Jl(PT-I8),
A75L300
I 50, I 50A thru I50M ,
Al50K, Al50L, Al50M,
I 52 and A I52
I 70A and I 70B
I 72, I 72A-M
I 75, I 75A, I 75B, I 75C,
PI72D
I77
I80, ISOA-H and ISOJ
I S2, I S2A-H, IS2J-N a nd
I S2P
(with Continental 0-4 70R
or 0-470S installed)
ISS, ISSA, ISSB
DHC-2MkI Beaver
Ayres
Ayres
Bellanca
Boeing
Cessna
Cessna
Cessna
Cessna
Cessna
Cessna
Cessna
Cessna
de Havilland
Piper
Piper
Piper
Piper
Piper
Piper
M-4, M-4C, M-4S, M-4T
BC-IA, AT-6 (SNJ-2), AT6A(SNJ-3), AT-6B, AT6C(SNJ-4), AT-6D
(SNJ-5), AT-6F(SNJ-6),
SNJ-7 and T-6G
J4E (L-4E)
Normal category
PA-IS ' I 50', PA-ISA
'150', PA-ISS ' I 50', PAISAS 'I50'
PA-ISA ' I50'
restricted category
PA-20, PA-20S, PA-20
'115', PA-20S '115', PA20 ' I35' and PA-20S ' I35'
with Lye I50 hp engines
PA-22, PA-22'-lOS,
PA-22-I35, P A-22S-I35,
PA-22- I50 and
PA-22S-I50
PA-2S-I40 , PA2S-I50
PA-2S-I5I
PA-2S-235
PA-23
If your aircraft is one of the above t ypes and
you wish to use MOGAS please contact Dr.
Hodges at the following address:
Dr. R. Hodges
(Churchill Heights)
RMB 4333 Rickards Drive
MORWELL VIC 3S40
Alternatively you may wish to phone him on
business hours (05I) 22-0200 or after hours on
(05 I ) 22-I845.
Please note that approval to use MOGAS in a
particular aeroplane will only be valid whilst it
is being used in the private or aerial work category and whilst it remains under the control of
the applicant for the supplement. New applications are required upon change of ownership.
The Gippsland Institute of Technology is also
the current holder of an Australian STC number
I46-I for t h e use of MOGAS in Beech A23-I9
aeroplanes. Dr. Hodges is also the relevant contact for anyone interested in the above Australian STC.
If you are interested in further reading on the
use of MOGAS in aircraft, the following
Airworthiness Advisory Circular (AAC) articles
are available through your local Airworthiness
Office:
AAC I52-I Use of MOGAS in certain light aircraft,
AAC I9I-2 Use of MOGAS in certain Cessna
aeroplanes, and
AAC I95-2 MOGAS correction D
Replacement
parts
~
N 19S7, a Bell 47G2 helicopter crashed in
UCanada. It was found that the steel core of
: the wooden blade had failed at a butt weld
2Scm from the tip. The blades were Hiller I2
blades which had been extended to suit the Bell
4 7. The modification is not approved by the
manufacturer nor is it authorised. A further 11
bogus blades have since been found by the
Canadians.
Such a weld can only be found by x-ray inspection. The bogus modificat ion is done in such a
way that it cannot be detected visually.
Two years earlier an Australian operator sent
his Bell 47 blades to the United States for overhaul. The blades were correctly marked a s
being manufactured by Bell. However, the overhaul facility reported the blades were in fact
Hiller blades which had been supplied by a
company in Torence, California.
Despite the best efforts of the CAA's Continuing Airworthiness Section, the FAA advised
that they were not able to take any action
against the company becau se the r elevant
records were no longer available. The lesson for
Australian operators is to have your blades
checked and be sure of the facilities you use for
overhaul and source of replacement parts.
The problem of bogus parts ext ends well
beyond Bell 4 7 helicopters. But bogus parts are
one side of the problem: the other s ide is
improperly or poorly overhauled replacement
parts.
Both t he cost of replacement parts and difficulty in obtaining them puts the pressure on to
use second hand parts. This is okay if the part
has been properly qualified and if it is the correct part for your needs. But, increasingly, both
these conditions are not met. Don' t assume that
this is an overseas problem, it is already here.
There ar e overseas companies which buy up
large amounts of used aircraft and aircraft
parts and sell them in ' a s new' condition w ith
t he full life of the original article. Some of
t hese companies do no more than clean the part
to make it look good. The worst companies will
change identification markings and sell the part
as genuine - the bogus p art.
As we saw in t h e Bell accident, bogus parts can
k ill. So can second-hand replacement parts sold
as new. The best protection for you is to use
only genuine parts . If you a re confident of the
source of replacement parts, t h en certainly do
u se t hem. If you h ave doubts, seek advice from
the aircraft agents or the CAA D
�1:
.
Aviation Safety Digest
141
Dear Sir,
I have just read with interest the latest Avia tion Safety Digest No. 139 and in particular
the correspondence from Michael Badge in the
'Airflow' section. Having just successfully
walked away from my first forced landing in 13
years of flying , I would like to relate my
experiences for my fellow readers, and
especially Michael.
Though the crucial phase of the forced landing
(that is, the landing itself) cannot be carried
out whilst simulating an engine failure during
instruction, I believe pilots can do a lot to prepare themselves for the day when the real thing
may occur.
Here are a few practical suggestions to help
prepare for the day when that reassuring 'purr'
up front is replaced by a deathly silence. Bearing in mind that a forced landing can occur at
any phase in the flight, keep a constant lookout
for suitable areas upon which to land, should
t he unexpected occur. Watch for any wind indicators, such as smoke, dust, windmills etc, and
update the information in your mind as often as
you can during the flight.
Remember that most light aircraft do not need
a runway the length of Sydney airport to safely
put down on. We are fortunate that the greater
part of Australia is relatively open farming
land, and even an area that looks the size of a
pocket handkerchief from 5000ft can be plenty
big enough to put down on and walk away
from. If over a built up area, a golf fairway or
a larger sporting oval is better than a suburban
street.
Whilst flying, especially over farming country, I
often indulge in a little mental exercise which
for want of a better name could be called 'spot
the power line'. Such things could obviously
cause a major hangup if one were to get tangled
up in them in the stages of a forced landing.
Most farm homesteads and sheds etc. have
powerlines in t he vicinity, so make a mental
note of where t hey are so as to avoid them
should a forced landing take place.
Over the years I have also made a practice of
simulating forced landings whilst in the circuit
area. For example, as you turn base, cut the
power right back and experiment with different
flap settings to adjust the rate of descent. Aim
for an overshoot on long final with no flaps ,
then gradually apply flaps as the field gets
closer. Try not to use t he power (unless you
have to, of course) because when the r eal thing
happens there is no power up front. Your glide
rate w ill be determined by the amount of wind,
the amount of height, the amount of forward
speed and the amount of flap. Spot landing
competitions are not only fun to participate in,
they can be very helpful for honing your skills
in this area.
Aviation SafetyDigest
141 ._
Whilst I do not pretend to be an authority on
forced landings, I recently walked away from
my first one in 300 hours of Private Flying.
Whilst flying an Auster J5G Autocar from
Wongan Hills to Bencubbin (W.A.), distance
about 65nm, and cruising at 2000ft agl just
after sunrise, number four conrod broke in half
and proceeded to demolish crankcase, front
engine mounts and cowling. The windscreen
immediately blotted out with oil, so forward
visibility was impossible. I was about 5nm
north of Koorda at the time, and as my height
would not have permitted me to make the local
town airstrip , I elected to land in a paddock
close to a farm house just to the left of my
flight path. The w ind was coming from the east,
so having shut the motor off, I commenced a
lazy spiral descending turn to the west which
brought me to the western side of the paddock I
had elected to land in. A quick check revealed
that the powerlines branched off to t he south
and east of the house, so I hoped there were no
more in the area.
Forward visibility was out of the question, with
an oil splattered windscreen and landing right
into the rising sun. The wind was a little
stronger than I had anticipated so I elected to
land flapless so as to make sure that I made it
over the top of some tall gum trees. The landing
was uneventful, though I found on a subsequent
ground inspection that the paddock was libera lly littered with many small heaps of rocks.
Fortunately the landing took place w ithout collecting any of these .
I was very thankful for the many hours of
simulated forced landing training I received
whilst gaining my licence. In the pressure of the
moment it is marvelous how it all comes back to
you. One final tip which one of my instructor s
impressed upon us in our training - 'if you are
going to hit any fence, make sure it is the last
one, not the first one '. In other words, if it is
impossible to land without hitting something in
the process, make sure you have got rid of as
much speed as possible before you do so. Try to
take the impact on the w ings, in the case of a
tree or powerpole etc., rather than with the
passenger compartment. Brake heavily , ground
loop if necessary. And remember that any
forced landing which you can walk away from
is a good one!!'
Hoping this article may be of some use in the
next Digest. Yours in pursuit of Air Safety
Cliff York
Hopefully to inspire some 'crew room' type dis-.
cussion I have included some thoughts I and
others in my crew have had over many years
on forced landi ngs. I will welcome useful
suggestions.
If you must land in tall trees, try to get below
the foliage and have the wings take the impact
on the trunks close to ground level. If this cannot be done, then use full flap, get as slow as
possible without stalling, level the aircraft and
gently let it down onto the tree tops. The
chances are sti ll high the aircraft will fall nose
first and ki ll you, but those chances are less
than stallin g into the trees. Every accident I
attended where the aircraft had stalled just
before hitting the trees has been a fatal
accident.
Ditching is a particular problem as the swells
are at right angles to the wind. I decided I
would always land along the sw ell line, even in
a very strong wind. To land into wind mean s
nose first into a wall of water unless you manage to put down just after a crest. It is important, again, to be as slow as possi ble, to adopt a
flat attitude and to keep control of the aircraft
- don't stall. Some people advocate a slight
nose high attitude. I think that as the water
gets closer you will inadvertently apply some
backstick anyway. The danger is in touching
the tail first and slamming the nose down so
that it digs und er.
With both landi ngs in trees and in the water,
the wheels should be up, if you have that
alternative. Wheels down gives more opportunity to turn the aircraft over. Keep the aircraft under control; don't stall and keep the
wingtips clear as long as possible. Finally, if at
all possible, use available engine power. If fuel
starvation is imminent and you are miles from
land, ditch while you still have engine
assistance.
Dear Sir,
The letter from Michael Badge in Digest number
139, bemoaning the lack of actual landings in
'forced landing' practice, is becoming a very old
complaint. Fortunately there is a partial answer
to the problem.
Many Flying Clubs and Aero Clubs throughout
the country have regular competitions, and a
common competition is a 'forced landing'* TO A
FULL STOP. This is completed on a runw ay,
and although it does not involve landing on
Q
~
~ ~
trees or water it is nevertheless useful- in building confidence for the real situation.
Anyone worried about this factor of training is
urged to find a nearby Club which has regular
competitions, and gain some practice below the
300ft minimum.
Yours faithfully ,
Lawrie Debnam
President
Cessna Flying Club Inc.
• T he 'forced landing' is conducted as a glide approach
from overhead the runway at 2500ft agl.
A note on anonymous contributions. The Digest
welcomes any item which will enhance safety,
including anonymous. Items which d o not have
a safety overtone will not be used. A recent
anonymous letter was very critical of the
Digest, air traffic services and the CAA.
Any safety message this letter might have contained was negated in the revelation of the
writer's abysmal piloting abilities. He was 'not
unduly concerned' when he missed a turning
point by 'a mammoth 100 miles' and descended
low enough to read a town name on the railway station. Twice in his short letter he talks of
nearly running out of fuel, once losing an
engine until he sorted out which tank was full
and which empty and once landing on an ALA
in the dark with emergency lights and insufficient fuel to reach the planned destination .
I mention this letter for two reasons. If you
wish to remain anonymous, we will respect that
wish and will still use your contribution if i t
contains a safety message.
The second reason is most important - i t goes
to the heart of safety. The regulations under
w hich we fly are there for our safety - pilots,
passengers and those on the ground. Th ey are
not there to restrict the rights of competent
pilots to fly.
No doubt there are other pilots with the attitude of our anonymous. Your attitude is unprofessional an d frightening to the responsible
p ilot. You must get your act together befor e
your act gets you.
WAAr WOLJL.t/
You L..IKE lo
f A\...K A&>t.J"f ?..
c
�
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141
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1989
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Text
The LAME is the
of airworthin
~~
ASD 140
AUTUMN 1989
Be alert to commercial pressures and complacency.
�Statement by Mr Alan Woods, Chairman of the Board
Aviation Safety Digest is prepared by the Civil
Aviation Authority and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots). registered aircraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
Contents
I
4
Flying to the black stump
7
Living with power lines
8
Autumn weather
Mail Order Sales
Australian Government Publishing Service
G.P.0. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
9
What the pilot doesn't see
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
12
Area forecasts
13
How far should passenger briefing go?
14
Some suggested 'rules' to improve our
R/T procedures
16
The false climb -
18
AIRFLOW
The Publications Distribution Officer (EPSD)
Civil Aviation Authority
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
©Commonwealth of Australia 1988
ISSN 0045-1207
R85/979(10) Cat. No. 87 1577 8
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
20
L
a fatal illusion
R
inging in the changes. In the last Aviation
Safety Digest we foreshadowed some changes
_ t o the ASD in line with suggestions from our
readers. This edition introduces some of those
changes with the inclusion of articles on
Airworthiness and other specialised areas.
A second change for the Digest is my appointment
as Editor. I hold a CPL, but most of my flying was
on helicopters and transport aircraft during 23 years
with the RAAF. I enjoyed a two year exchange with
the USAF, during which I mainly flew the King Air
8200. At that time I completed six American and
Canadian accident investigation and prevention
courses and wrote many articles for the USAF's Flying Safety magazine.
The RAAF posted me to safety in Canberra where I
looked after all our transport aircraft and was the
safety Spotlight magazine editor. In both Australia
and the States I have investigated a number of accidents, every one of which included a fatality.
Beyond the call ... of duty
Covers
21
The purpose of the CAA could be summarised as
being to enable more people to benefit fr.om sate
aviation. The Authority plans to pursue this through
a focus on Safety, Efficiency and Service. Our prime
objective, in accordance with the Government's
intention and the CAA's legislative obligations, is to
promote aviation safety. It is recognised though that
safety is not without cost to industry, and ultimately
cost to the travelling public. There is a need to maintain proper balance between the two, as a contribution towards keeping flying from being priced
beyond the means of the majority of the public.
Australia's excellent safety record in aviation has not
come about by chance. It results from ongoing commitment to safety on the part of both operators and
Safety regulators. I applaud the dedication and professionalism of the many people involved. To maintain this record will require the continued effort and
co-operation of all parties in a more rapidly changing
and complex environment.
Editorial
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, AC. T. 2601, AUSTRALIA
Telephone (062) 68 6319
ast year saw major initiatives by the Government
in aviation administration in Australia. The Fed_eral Airports Corporation took control of most of
Australia's larger airports on 1 January and the Civil
Aviation Authority assumed responsibility tor safety
regulation and the air traffic services system on 1
July. A further element of the Government's strategy, economic de-regulation of domestic trunk route
services, is to take effect in October 1990.
These changes are timely in meeting the challenges
which lie ahead. The next ten to fifteen years will
see significant changes in the areas of new technology aircraft, satellite-based communications. navigation and surveillance systems and runway
precision approach systems.
Economic de-regulation, when it comes in 1990, will
bring a more diverse and changing commercial aviation environment than we have faced in the past .
This will call for adaptability and innovation on the
part of the CAA as well as the aviation industry.
The Authority is moving to equip itself adequately to
meet the demands which a de-regulated environment may bring.
QUIZ - How well do you know your
GAAP procedures?
I believe very much in the role of the Digest to help
us all enjoy our flying by creating a safer environment. I believe that with expanding fleets and new
technology the time is ripe to widen the role of the
Digest to make it an informed forum for all those
engaged in aviation activities. It is in this way that
we will attract a wider readership which will result in
a better informed community.
My thanks to David Robson, the previous Editor,
who's excellent work on the Digest has set a very
high standard. To help maintain that standard I will
welcome positive suggestions and criticism from
you, the reader. Your input is vital; it allows me to
gauge the effectiveness of the Digest and to include
safety information you see as being important.
~~
Editor
Editor:
Editorial Assistant:
Graphic Design:
Al Bridges
Karen Hutchison
Lesley Boulton
Photographs:
Steve Small
S. Hopper
P. Machin-Everill
Front. Ayers Rock - a different view.
Cloud dropping over Ayers Rock in mid
1974.
Photographic entry by Yvonne M. Dobinson
Back. Airworthiness poster.
Design by Kathy Walter
P4
PB
P20
Diagrams:
P7
P16-17
Cartoons:
P14
P15
Ag. Pilots Manual
Peter Garfield
Peter Garfield
Lesley Boulton
�Aviation Safety Digest
140
The right aircraft
Bob explained how I should consider the distance to be flown, the number of passengers
and the amount of luggage we would need to
carry .
On this trip there would be four of u s in the
aircraft and we would be away for seven days.
As we would be operating over remote areas I
would need an aeroplane wit h good radio gear,
in particular HF.
r
Pilot contribution
few months ago a friend of mine asked me
to take him and a couple of others on a
_ _! little flight. When I asked where to, he said
'Birdsville'.
Well like any good mate, I agreed.
When he left I wiped my brow, hoping he
hadn't seen the glistening beads of sweat that
had formed as I contemplated what I had just
done. Me, fly to Birdsville? I didn't even know
where it was. Oh I had heard of it all right, and
had often wondered what it would be like. I
knew that it was way out west in a desert
somewhere, but that was the s um total of my
knowledge of the p lace.
I made a dash for my friendly atlas and after
several minutes scanning the maps of three
states, lo and behold, there it was in the south
western tip of Queensland. A long way from
anywhere.
By this time swallowing was becoming a bit
hard; I had suddenly grown a golf ball in my
throat. 'What am I worried about', I thought,
and tried to settle myself down. 'After all it's
only a little bit further west than I've flown
before'. About four hundred miles!
I spent the rest of the night tossing and turning; my wife spent it snarling. Women, they just
don't understand this aviation business. This
latter point was brought home to me very
forcefully next morning over breakfast when I
was trying to explain to her the incredible
dangers I, her brave spouse, a true man
amongst men, would face navigating a tiny aircraft across corpse ridden deserts, and the
occasional crocodile festooned river. She raised
her eyes from the morning paper, looked
squarely at me and said, 'thats w hat you spent
a ll our money training for isn't it, or do I ask
for a refund?'
She was right. I had spent many thousands of
hard earned dollars beavering away trying to
•'friN•
-
attain a childhood dream, to learn to fly. Here I
was at last with a nice new private pilot licence
and the opportunity to use it. Why was I so
nervous?
With a new sense of purpose I sat down and
spent the rest of the afternoon thinking about
the forth coming trip, just three weeks away.
What would I need to do, where should I start?
Well I thought the first thing to do would be to
obtain a new set of WAC charts. I bought a new
set from t he CAA Administration building at
Bankstown Airport and sat down and studied
them in detail. While that helped me get a grip
on things I felt that I should really be talking to
someone who had lots more experience than
myself. It was then that old Bob, my instructor,
sprang to mind. He had so recently patted me
on the back and pushed me out the door probably hoping that he had seen the last of me for
a while. He was just the person to handle this.
Next day I packe d up my charts, bundled them
into my trusty Volkswagen and headed for the
flying school and my instructor.
'Hey Bob' I said, 'I am going to Birdsville in the
next few weeks and I was wonder ing if you
could spare the time to give me some advice
and help me plan it?' 'Sure mate, if you go
about it corr ectly and carefully you will have a
great time, its really fabulous country out
there, a gr eat flying experience.'
Well, over the next few days we p lanned the
trip. Deciding to ask Bob was one of the best
decisions I made. His experience and assistance
was of immense help.
Bob told me that I should look at a ll trips, not
only this one, in close detail. He said that as my
experience increased I would feel more comfortable and confident in making more decisions for
myself, but that I had done the right thing in
seeking advice from an experienced person and
to a lways seek advice if I felt the slightest
doubt about anything. Between us we identified
the following points to consider for this trip.
We chose a Cessna 210, not because it was the
only type suitable as there are many that would
fill the bill. Basically, the requirement for
space, speed and range could be met by several,
Bonanza A36, Piper Saratoga, etc, but I decided
on the 210 because of its availability and my
familiarity with the type.
HF radio was important because Bob explained
that although I could legally go SARTIME I
would be far better off to accept the protection
of the system and opt for Full SAR by making
regular position reports. This sounded like a
good idea to me. If the worst should happen at
least the rescue teams would know where to
start and if I kept the reports to every thirty
minutes or so the area to be searched would be
relatively small giving us the best chance to be
found quickly .
Route
Bob explained that the route I should choose
need not be the most direct; in fact that rarely
would be the case on any flight. He explained
how important it is to plan to fly over the best
terrain to avoid mountain chains and large
stretches of desert. He went on to say that I
should study the charts and select a route that
overflies topographical features that would be
easy to identify from the air, such as towns,
major river systems, dams, power stations, railway junctions and prominent geological features. After selecting the basic route it would
then be time to compare my choice against the
CAA charts to see if the route selected needed
to be adjusted to avoid r estricted areas or if it
passed through any control zones or controlled
airspace. The restricted areas would need to be
avoided while the latter would need to be
marked on the WAC and an alternative route
selected and marked in case a clearance
through CTR or CT A was not available on the
day. Fuel was also a consideration. Bob told me
that I should also give some con sideration to
refueling stops, as fuel is not always available,
and, when it is, it is sometimes sold from
drums. I had heard of the precautions to
observe with drum refueling, like making sure
the cap was secure, no water, proper filtrat ion,
never use the last gallon or so in the bottom
where all the rubbish settles. But what I didn't
know was that you are normally expected to
buy the whole drum, regardless of how much
you need. Therefore, if you don't plan the
refueling stops carefully you can end up wasting an awful lot of money just to get that
needed extra few litres.
Radio
The decision was taken, then, to operate full
reporting, t hus availing ourselves of the protection of the SAR system should the worst happen. With the decision made to proceed full
SAR Bob explained that I should try and select
a route that w ould allow me to maintain VHF
radio contact as much as possible. I hadn't
thought of that really, I considered that as the
aircraft would have HF radio fitted it wouldn't
be a problem. When I expressed this v iew Bob
nodded w isely then explained how difficult it
can be at times to establish HF contact due to
sun spot and atmospheric activity. What he
said made good sense, so we went back to the
charts and compared our proposed route
against the FISCOM chart. We found that if I
planned to fly about 5000 feet I would need to
adjust one of the legs further north by about
fifty miles. Bob explained that I should consider
5000 feet for planning radio reporting because
if I used the FISCOM to select a route that was
near the edge of the 10 OOO foot shaded area I
would be in bad shape if poor weather forced
me lower. In practice all I had to do was select
a track well within the shaded area. In the finish I was left with a section of about 150 miles
over which VHF contact might be doubtful. Not
too bad.
Time frame
You might be scratching your head wondering
how I came to allow a week for this trip, particularly as I would be flying a 210. No its not
because my select ion of the route had us going
via Perth, its just that as my friend wasn't in a
hurry to get to Birdsville and back we decided
that the trip should be taken steadily with
reasonable stage lengths each day. We also
decided to allow an extra couple of days in case
the weather bombed out and we were stuck
somewhere en-route for a while. Bob thought
that about three hours should be the maximum
planned stage length on any one day. He
explained that as I was a relatively newly
licensed pilot a stage len gth of three hour s
would probably see me out physically and mentally. Besides, it would ensure that I always
had enough fuel left to mount a search or
divert if I either got lost or some other unexpected calamity should occur. During the actual
flight I was really thankful I had taken Bob's
advice on this point, he was dead right, after
about three flying hours I was bushed. With all
the preflight and post flight activities of planning and checking I found that I spent on average about an extra two to three hours each day
on top of the flying time.
�Aviation Safety Digest
140
Aviation Safety Digest
140
Survival gear
Apart from the radios fitted to the aircraft I
also obtained the loan of an ELT from the flying school. I figured that although it wasn't
legally required to be carried, as we had HF, I
would be a damned fool to leave it behind. At
least it had a separate power source and would
work even if the aircraft's battery was flat and
I reckon that that alone is a good enough
reason to carry one. You never know what
shape the aeroplane may be in if you are forced
to make an emergency landing!
Water is another problem. When the air temperature gets to around 35 degrees Celsius we
each need between 4.5 and 5.5 litres per day to
survive. With four of us on board I decided to
carry 20 litres. As it would be mid August
when we went I was hopeful that the daily
maximum temperatures would not be quite that
high. In any event it gave us a full days water
each, and hopefully with us operating full
reporting we would not be out there too long if
we came down.
Food wasn't much of a consideration, as we
could go a lot longer without food than water.
However, knowing that my nerves would
demand that I chew something I decided to give
my fingernails a break and packed a selection
of things that didn't need water to prepare, or
too much to metabolize. Dates, sesawheat biscuits, sugar cubes, barley sugar sweets and a
nice selection of cheeses filled the bill. Clothing
requirements were to ensure that we had sufficient body protection from the sun during the
day and something war m for the nights, as
although it can get very hot in the daytime the
clear night sky means that it also gets mighty
cold just before sunrise. Everyone was advised
to bring a jumper or jacket and something light
with long sleeves and a good hat to help avoid
sunburn during the day. I also decided to pack
a can of insect repellant to keep 'Louie' at bay.
The flight
'Well how did the trip pan out' I hear you ask.
Not bad actually. There was one time when I
was 'temporarily unsure of my position' but as
I had prepared my charts by penciling in each
track, 10 degree drift lines, lOnm markers and
a half way point it ma de the actual en-route
navigation problem mainly one of finding my
pencil. The one time I did momentarily get
bushed I was quickly able to compare distances
between each 10 minute pinpoint I had been
plotting on the ch art and suddenly realised that
I had misidentified Mt Howitt. I was able to
quickly establish my error w hen my nav computer revealed the distance between each of the
previous pinpoints related to a groundspeed
150kts. My last pinpoint had us suddenly back
to 90kts. Obviously I had either made an error
or flown into a hurricane. As the weather
beyond the perspex hadn't changed I decided it
must have been me! When I applied 150kt
groundspeed since my last pinpoint I came up
with a new position on the chart. Suddenly the
picture outside made sense.
The picture outside is another story. I found
that over feature rich terrain it was easy to
establish my position by reference to a few of
them. After all, I had deliberately planned to
make it easy for myself. However as the terrain
flattened out and definitive features became
fewer I used the 'big picture' more and more.
As an experienced bush pilot once told me its
'macro' navigation versus the 'micro' navigation
us fringe dwellers normally use.
I deliberately kept busy with the navigation. As
we went further out west I realised that if I
slackened off, just for a few minutes, landmarks were so rare that one could easily go by
unnoticed. If that were to happen I sensed I
could easily lose the flow of things and make
an error. I think thats what happened at Mt
Howitt but luckily my log keeping had been
consistent and accurate, and I was able to
quickly remedy the situation. However if I had
been a bit s lack with my log I reckon re-establishing my position would h ave been pretty
difficult.
The weather was pretty good for most of the
trip so I flew the highest quadrantal level available. The radio communications were just as
Bob had explained they would be. I had good
VHF communication for most of the trip. The
only time I had to resort to HF was around
Cunnamulla . I was surprised to note during
planning that there is a VHF repeater at
Birdsville. So I was even able to talk to
Charleville via VHF on the ground.
We stayed at Birdsville for a couple of days;
most of it I even remember. Let me just say
that t he night life at Birdsville is really something else. I do hope the Hotel's dog, Boss, has
forgiven me. He spent a long time trying to
push me out of his favorite spot in the gutter,
but t hat's another story.
What more can I say. The trip was a howling
success. We all had a great time. The flying was
made a lot easier by the careful planning Bob
and I had done before I left. By applying all
that I had been tau ght and keeping an accurate
log of my positions and fuel burn-off as I went
I know I saved the day at least once.
That, after all, is why I had taken all that
trouble in the first place. Out in that country
you only need one mistake.
It was probably the most challenging and enjoyable trip I have undertaken so far. I still get
Bob t o run his eye over any trip I plan for t he
first time. His comments are getting fewer as I
get more experience, but when he says something, its a gem 0
The solution to the problem takes two obvious
forms:
Living with
power lines
First - Never fly at an altitude where wires
may be encountered , wit hout first surveying
the area to locate the wire clu es and the wire
runs t hemselves. Any doubt as to the advisability of this statement can be alleviated by
asking an experienced ag. pilot to descend to
wire height in an ar ea he hasn't previously surveyed. He s imply cannot do it. Yet he is down
there every day and knows the wire clues backwards. Our military aviators, too, conduct a
thorough wire survey before allowing low level
operating in any exercise area.
by John Freeman, Examiner of Airmen (Agricultural), CAA
Second - When flying at wire height increase
your field of vision by moving your head from
side to side - just as forward looking low level
radar does, it has a field of vision problem too.
Never, but never fly at wire height looking
straight ahead otherwise the first wire clue you
will see is the w ire itself a few feet in front of
your face.
"'~ ET ANOTHER accident where a helicopter
~ flew into a wire at right angles to its flight
._ path prompts further thought into possible
reasons.
Note: The Agricultural Pilots Manual gives a
wealth of information on how to locate wires 0
In this case the helicopter was following a road
carrying out a filming exer cise with r ally cars
travelling along the road. The clues to the wire
were poles either s ide of the road. Unfortunately, one was hidden by trees but the other
was in plain v iew.
This accident mirrors many others, s ome of
which have had poles in excellent view. A large
cross section of aircraft have been involved,
agricultural, helicopter, fixed wing survey and
private. The incidence is obviously higher in
undulating terrain where wire spans are larger.
I
A IRCRAFT
TRACK
WIRE
WITHIN RANGE OF
VISION BUT OUTSIDE
FIELD OF VISION
OF
v,
~~1-
Why does a pilot fail to see such obvious clues
as poles on either side of a valley or in open
cou ntry? Maybe the answer lies this way -
70°
'r---1
PILOT'S EYE
The general field of vision is approximately 70°,
i.e. 35° either side of straight ahead. The range
of vision in locating and identifying potentially
threatening items is limited by background ,
camouflaging effects, glare etc. Car eful study of
the diagram will show that there is a strong
possibility that when the clues to the wire are
within the field of vision they are outs ide t he
range of vision. When they are within t he range
of v ision they are outside the field of vision.
In t his event the sober t ruth is t hat unless t he
location of a crossing w ire is determined before
descending to its level, it may be physically
impossible to see the clues, looking straight
ahead, and collision is inevitable.
WITHIN FIELD OF
VISION BUT OUT
OF RA NGE
<;>Of \11s 10
~
~
~~
70°
H
PILOT'S EYE
I
AIRCRAFT
TRACK
POLE
�Aviation Safety Digest
Aviation Safety Digest
140
140
How successful are we?
What the pilot
doesn't see
This article is a precis of a talk given by Alan Emmerson,
CAA Airworthiness Engineer, to a safety seminar at the
Bicentennial Air Show
Aircraft safety starts with safe aircraft
.., HERE seems to be a view at large that since
we happily kill 1500 people a year on Aus. .::..tralian roads, there is no need for further
effort in aviation where we only kill 40 people
a year.
My response is: 'That's six Australian Boeing
747s a year - one every sixt y days for ever.
Where would you like the first one to crash,
Botany Bay or the Blue Mountain s?'
The approximate accident rates which describe
the risk you take when you drive a car or fly
an aeroplane are shown in Figure 1. Bear in
mind that the aviation accident r ate shown was
achieved in a climate of very strict control of
a ll aviat ion activity.
Autumn weather
Bureau of Meteorology
VIATION Safety Digests 137 (Winter 1988)
and 139 (Summer 1988/89) contained
., articles dealing in considerable detail with
aspects of aviation weather in those two
seasons. Autumn generally sees the progressive
transition between the weather experienced in
summer to t hat in winter, with features of the
summer scene (particularly the convective
activity in northern Australia) often persisting
into early autumn and fe atures of the winter
scene often evident in late autumn.
Generally good flying conditions are experienced during the daytime in mid-autumn. However pilots should be wary of:
• carburettor icing, particularly if flying in low
level moist onshore streams.
• running out of daylight as the days a re rapid ly shortening.
• increased incidence of fog/low cloud.
A
Average number of fog days (per month) at
various locations showing increased inciden ce
from late summer through autumn.
Rockhampton
Richmond NSW
Canberra
Launceston
FEB
MAR
APR
1
2
1
1
1
5
3
3
2
7
4
4
MAY
4
9
8
6
Late autumn generally sees an increase in the
frequency of cold frontal and stream weather
along the southern coastal areas of Australia.
With these fronts are wind changes, often low
cloud, reduced visibility, precipitation, wind
shear and turbulence. (An article is planned for
the Spring 1989 edition w hich will give more
information on flying aspects of frontal
weather).
While talking in very broad terms about 'average' autumn weather, large variations from the
'average ' may be experienced, e.g. a late season
tropical cyclone affecting northern coastal
areas, an inland deep low pressure system or an
upper air disturbance leading to very poor flying conditions. The principles of 'weatherwise'
flying must a lways be observed even at this
generally 'weather-benign' time of year. Anticipation and proper preparation are the key
elements to obviate any potential problems t hat
may arise D
COMPARATIVE ACCIDENT RATES
Fatal Accidents
Per Million Hours
of Travel
Rural Roads
30
Urban Roads
55
All Australian Roads
38
General Aviation
13
Fig ure 1
Airworthiness control
Airworthiness control is exercised by the CAA
through the Airworthiness Branch to formulate
regulations intended to protect people from
physical or financial injury caused by an
aircraft.
To do this we specify the design , maintenance,
repair and construction standards for aircraft
and components and we review submissions by
the industry in accordance with the standards.
We then maintain surveillance of industry's
compliance w ith the standards; and we investigate problems found with aircraft in service,
both in Australia and abroad. Finally, we exercise whatever control action is necessary to
ensure that the standards are met.
We may never know the extent of our success
because the acceptable accident r ate is so low
that t rends are ma sked by chance occurrences.
The data in Figure 2 describes r ecent Australian experience and shows the number of
reported aircraft incidents in w hich BASI invest igators determined that malfunction of part of
the aircraft was a principal or contributory
cause of the incident. Excluded are
malfunctions obviously caused by flight crew
action - s uch as doors being left open. In
short, they are airworthiness problems .
AUSTRALIAN AIRCRAFT INCIDENTS
WITH MATERIAL MALFUNCTION
AS CAUSAL FACTOR 1982-1987
Attributed to
Number Reported
> 5700 kg < 5700 kg
auw
auw
Design or
Manufacture Fault
26
144
Maintenance Fault
70
452
Other Cause
17 20
6242
Total
18 16
6838
Figure 2
What t his means is that four times every day in
Australia, the safety of an aircraft is prejudiced
by a malfunction. We h ave an unpleasant ma intenance error every three days. You pilots and
passengers should be t he judge of whether
that 's good enough.
New technology
We are of course obliged to keep our standards
up to date. Over the p ast two years we h ave
put a major effort into rev iewing these standards especially in t he light of new technology.
Not surpris ingly we found t h at for each technological change there was an upside and a down
side - a gain and a risk. The changes we investigated included:
Continuously operated full authority
automatic fligh t controls;
Gust a lleviation systems;
Electrical display and signaling in-flight
controls;
Winglets;
Propulsion fans ; and
Fibre reinfor ced plastics .
Aging aircraft
The mention of new s truct ural materials leads
on to what has been anot her m ajor worry for
us over the past t wo years. This is t h e matt er
of aging aircraft . It is not a new problem,
r ather its an old one revisited.
�Aviation Safety Digest
Aviation Safety Digest
140
140
In the period 1976-1979 , severe structurally significant cracking was found unexpectedly in a
number of different types of modern airliner.
This was the era of the so called geriatric jets.
There were several tragic accidents.
The one which provided the answers was t hat
which resulted from the inflight failure of the
starboard tailplane of a Boeing 707 at Lusaka
on 14 May, 1977. Because of an error in the
design and certification process of a new model
the tailplane spar failed through fatigue and
inadequate inspections.
As a result of these incidents we all tightened
up our regulations - not so much by making
them more stringent but by trying to say what
we really meant.
Then on 12 August 1985, a B747 of Japan Airlines crashed into Mt Ogura, Japan, killing 520
people. The accident was caused by secondary
damage resulting from rapid depressurisation of
the cabin following a fatigue failure of the rear
pressure bulkhead. No inspections of the rear
pressure bulkhead were scheduled because
Boeing believed that any cracks would be obvious and would be detected before becoming
catastrophic. The fatigue process was aggravated by an improper repair to the bulkhead
seven years earlier.
Following the Japan Airlines accident, inspection of several B7 4 7s revealed widespread
fatigue cracking in the forward fuselage. Aeroplanes were found to have adjacent frames severed in such a way that a coincident skin crack
only 20cm long would have resulted in explosive decompression and probable destruction of
the aeroplane.
It is reasonable to suppose that, if the JAL accident had not happened, a catastrophic failure
of a forward fuselage would have occurred
somewhere in the near future.
On 29 April 1988, a B737 of Aloha Airlines
experienced massive damage to the pressure
cabin in flight at an altitude of about 24,000
feet. Sixty passengers were injured and a flight
attendant was blown out of the aircraft. There
is little doubt that the cabin rupture was
caused by fatigue cracking.
The generally held view is that the continued
airworthiness of those aircraft types and their
cousins is ensured for the immediate future.
But, extreme vigilance must be maintained,
with no further complacency, so that problems
which do arise will be recognised and quickly
dealt with.
I don't want you to think that the problems of
aging aircraft are confined to airliners. If you
look at an age profile of the Australian fleet,
you will note that we have 4000 aeroplanes in
the 10 to 25 year age bracket.
Many people were surprised when the wing
broke off a Beech King Air that was only thirteen years or 5000 hours old. The accident
resulted from fatigue initiated by a metallurgical fault. The time between inspections was too
long and one inspection seems to have been
done improperly.
There have been quite a few near accidents of
the same general type in Australia, and some
catastrophes.
There is particular significance of these events
to the remainder of what I have to say . In each
event there was a substantial contribution from
human error in the airwort hiness control
process.
Human error
Before discussing human error, I should make it
clear that, in my view and that of our chief
engineer, an honest mistake made under intolerable pressure or at the edge of the state of the
art does not constitute negligence or
incompetence.
The conventional view of the direct causes of
major accidents to commercial jet transpor t aircraft is something like this:
• Flight crew error 55%
• Aircraft design, manufacture and maintenance
18%
• Other known causes 12%
• Unknown 15%
I would like to offer an alternative view which
was presented to t he 1986 Flight Safety Foundation seminar.
The airworthiness of aircraft systems w as the
first event in the chain in 39% of accidents to
large aircraft. A reasonable hy pothesis from the
data is t hat human response to airworthiness
problems causes about 20% of accidents. Moreover, we must not forget t he errors t hat are
made but are detected by the airworthiness control system.
In discussing human error I want to move away
from the past concentrat ion on 'operators '. We
should now be looking at the singular actions of
key people, especially those actions in which
the output is a decision rather than an operation , and including those w here the wrong
decision has an unwanted result, not immediately, but fifteen or twenty years on.
An important example of human error is t he
situation in which the doctrine fails. That is,
when the received theory, held by the profession to be generally applicable, is erroneous.
Because they are so per vasive, doctrinal errors
are often ve ry serious. They can have important financial consequences for the industry
which has used the faulty doctrine. This also
leads to pressure being placed on the regulatory
authority to relax safet y standards while the
situation is recovered.
Doctrinal errors a re ever y bit as much human
errors as dropped spanners and cockpit
confusion.
How about errors which occur by chance?
On New Year's Eve 1968, twenty-six people
died in Western Australia from impact forces
experien ced when their Vickers Viscount hit the
ground after a wing broke off. About four years
earlier, somebody found that a steel bush in the
wing s par wa s not a light interference fit as
requ ired. He belled out each end of the bush 0 .1
mm with a conical tool and drove the bush into
the hole in the spar. The result was invisible.
But by changing the local stresses and surface
finish he reduced the fatigue life of the spar to
one half of its expected worst possible value with catastrophic consequences .
Who could have expected that?
If we have a large range of possible error types,
and a consistent cause of error cannot be found,
and the time between errors cannot be pr edicted, then we have chance errors, and there is
little we can do to prevent them happening.
What we can do is find the errors a fter they
have been made and before t hey do damage.
Everything must be checked, and checked again
and checked that it was checked. The manufacturer designs the aircraft, the country of
origin's airworthiness a uthority checks the
design, and the importing countr y's
airworthiness authority independently spot
checks it again.
Such redundancy is, and has been for many
years, a fundamental component of aviat ion.
However, the reasons for it have not been well
documented and it is expensive . In today's
financial climate it is under threat.
In changing times it is easy to overlook or
ignore not only t he lessons that have taught us
the need for redunda ncy but also the conditions
that are needed t o make it work.
There must be the time and the mean s for the
inspectors to find errors and to respond. Each
person must be given adequate role t raining and
direction so t h at each under stands what he is
expected to do w hen , where and why. There
must be a proper arrangement of role relationships so t h at the authority delegated to each
person is clear both to him and to his
colleagues.
The people should be t echnically well trained
and sufficiently confident in that training to
challenge things that do not seem to be right.
They should s tick to established organis ational
procedures, but above all they must keep their
imagination working.
Most of those precautions seem to h ave been
absent in t he lead up to 25 May 1979 when a
DC 10 suffered a structural failure during takeoff. Two hundred and seventy three people
were killed. The aircraft crashed becau se t he
pilots w ere unable to control its flight path
after an engine and its support pylon broke
from the wing and severed h ydraulic a nd electrical connections as they left.
This accident was an orchestration of human
misjudgment - human errors in design and in
maintenance, human error in airworthiness control. (For a full description of t his accident you
should read the NTSB report).
This brings me to the question of motivation.
What motivates the key people in aircraft
design, manufacture , and maintenance to
behave with the care, skill, concentration and
persistence necessary for safe aviation?
I have no doubt that character is of primary
importance in aviation safety. We need people
who have:
• 'a h igh level of responsibility for the welfare
of others,
• a high level of personal integrity, and
• a high level of self discipline'.
Those are not my words but t hose of the Technical Director of IATA Dr RR Shaw a for mer
chief engineer in the Australian Department of
Civil Aviation.
I expect engineers who work for me to have:
• an enquiring mind with sufficient curiosity to
notice and find out why;
• sufficient persistence to get to the bottom of a
problem;
• clarity of observation, clarity of thought, and
clarity of expression;
• t he ability to get on with people - especially
when persistence is not welcome; and
• a healthy prot ective anticipation.
I would like them to develop a 'd eep inner conviction or compulsion that permits no personal
indifference, or surrender to expediency, or the
taking of anything for granted in the discharge
of their responsibilities'.
It has been said that there are 'aeroplane
people', those who understand what aeroplanes
can regularly do and what they cannot; and
what is necessary to keep them going - in the
air , airmanship , on the ground, engineering
j udgement .
Perhaps t h e an swer to t he question of motivation is simply t hat in the past, aviation has
attracted men and women of determination and
integrity. These would h ave known t hat there is
intrisic merit in doing thin gs properly and in
getting it right the first t ime. Importantly, they
would have had t hose qualities of personality
which lead others to behave in the same way.
I want to leave y ou with the idea that the prevention and detection of human e rror in design
and maintenance decision making is a primary
part of airworthiness cont r ol.
'An aeroplane is ten million human judgements one ofthemfoolish none infallible'
�Aviation Safety Digest
If you are not elig ible for a free issue, or if you would like additional copies of the Digest:-
140
Area forecasts
conditions to occur, e.g. a s a result of t opography, or the influence of different synoptic or
dynamic factors. If sub-divisions are defined
here, they are retained in the remainder of the
ARFOR. If a pilot is operating through part of
an area only, then he can identify and concentrate on those sub-divisions appropriate to his
flight.
Winds and temperatures
Bureau of Meteorology
""": HE DOMESTIC area forecast system,
ARFOR, is assigned primarily to meet the
~ needs of pilots of general aviation aircraft.
There are 35 areas for which forecasts are prepared, covering Australia and the nearby
waters.
Weather conditions may vary quickly in time
and over short distances in space. Consequently
in changing weather conditions, when forecasts
are most crucial to flight safety, ARFORS tend
to become very complex and lengthy. A revised
format was introduced in an attempt to make
the ARFOR more 'user-friendly' and overcome
other difficulties (e.g. excessive use of codes,
poor presentation). Some information on each of
the sections now contained in the ARFOR
follows.
These are provided at intervals from 2000 feet
to 18500 feet. The forecasts are prepared in
tabular format for easy interpretation.
Cloud
Some changes have been made to the previous
guidelines on cloud. The term 'layers' is now
used if appropriate. Also if differing cloud
types with reasonably homogeneous bases
exceed 4/8, then they are collectively
referred to as BKN.
Weather
More plain language is used in this section.
Visibility
If the vis ibility exceeds 1Okm the precise value
is not specifically referred to. If fog is referred
to in the Weather section, then it is assumed
the visibility is less than lkm in fog areas.
Overview
The aim of this section is to highlight the more
significant information by referring to meteorological conditions that may be hazardous or
impair aircraft operations us ing visual flight
rules. It contains reference to affected regions,
and spatial and temporal variations, as
required. The Overview will immediately indicate if conditions throughout an area are very
poor, marginal, deteriorating or improving. The
pilot will still be required to examine t he body
of the ARFOR to obtain the relevant details, but
this can now be done with h elpful background
provided in the 'Overview'.
Four issues $A 14 .00
or ove r thirty years, the Aviation Safety
Digest has been an integral part of
Australian aviation.
In July 1986, responsibility for the Digest was
transferred from the Bureau of Air Safety
Investigation to the Flight Standards Division of
the then Australian Department of Aviation
(now CAA). This move reflected the perception
that civil aviation may have reached the limit of
accident prevention through regulation and
that the way forward is through increased
emphasis on safety education in general, and
the 'human factor' in particular. Rather than
just draw lessons from accident investigations,
the Digest will increasingly seek to influence
(including surface postage)
pilot behaviour by positive reinforcement of
sound techniques. It will examine all aspects of
piloting and publish formal results as well as
'the tricks of the trade'. The 'crash comic ' will
become a 'how not to crash ' comic.
Anyone with an interest in aviation wi ll benefit
from tapping into th is unique source of the
accumulated wisdom of the profession and
the latest research into aviation safety in
Austra lia. Indeed, anyone w ith an interest in
high technology and the roles and limitations
of the human operator w ill find this publ icat ion enlightening .
Freezing level
The subdivisions are used if appropriate.
Icing
------------------------------------------~--
If CB cloud is forecast, then severe icing is
assumed.
Turbulence
If CB cloud is forecast then severe turbulence is
assumed. Generally the main types of turbulence referred to are clear air and mechanical.
Sub-divisions
Critical locations
Frequently there are marked variations within
an ARFOR, on a temporal, spatial or weatherrelated basis. 'Sub-divisions' are used in an
ARFOR if the forecaster expects contrasting
These are written in plain language in T AF format, with information on cloud, visibility and
weather. Variation terms (INTER, TEMPO) are
used as appropriate D
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
P.O. Box 367
CANBERRA A.C.T . 2601
Au stralia
There must have been a real strong headwind to
make us land so far short of the overrun
Extract from accident report
Aviation Safety Digest 140 / i
�Safety contacts
Safety promotion liaison officers
Central Office
Telephone
062 686294
Steve Small
Aviation Standards Division
Civil Aviation Authority
GPO Box 367
CANBERRA CITY ACT 2601
FACSIMILE: 062 497349
NSW
John McQueen/Mary O'Brien
Aviation Standards
Civil Aviation Authority
P.O. Box 409
HAYMARKET NSW 2000
02 2187111
VIC/TAS
Mark Perrett
Aviation Standards
Civil Aviation Authority
G.P.O. Box l 733P
MELBOURNE VIC 3001
03 6622455
QLD
Bill Taylor
Aviation Standards
Civil Aviation Authority
P.O. Box 10023
Adelaide Street
BRISBANE QLD 4000
SA/NT
Ian Smith
Aviation Standards
Civil Aviation Authority
G.P.O. Box 2270
ADELAIDE SA 5001
WA
Lesley Smithers
Aviation Standards
Civil Aviation Authority
G.P.O. Box X2212
PERTH WA 6001
07 8336211
Kawasaki BK117, 15 January 1988
08 2180211
09 3236611
Pilot Safety Awareness Seminars
These are conducted in association with the Aircraft Owners and Pilots Association. The program
for the remainder of 1989 is as follows:
April 29
Coolangatta
May 27
Broken Hill
June 24
Canberra
July 29
Perth
August 26
Dubbo
September 23
Rockhampton
October 21
Mount Gambier
November 25
Moorabbin
The above dates are provisional, and accurate at time of printing. Final dates, themes and venue
details are published in the AOPA monthly Journal in the months preceding the event.
BASI contacts
24 hour contact numbers for BASI offices:
Canberra
Adelaide
Brisbane
Melbourne
Perth
Sydney
(008) 02
(08) 218
(07) 835
(03) 663
(09) 378
(02) 281
0616 or (062) 57 4150
0579
3676
7015
1333
3120
Accident response
As a descent was commenced, the left engine access cowl unlatched and struck the main rotor
blades. Vibrations were so severe that instruments could not be read. The pilot elected to land in
the water close to a beach.
BAS! recommendation
The CAA should evaluate suggested modifications to the latch system.
CAA action
Airworthiness Branch and Kawasaki have investigated the proposed modifications. It was decided
that a modified latch system would be mandatory on any BKl 17 aircraft on the Australian register.
Piper PA25-260, 19 March 1988
The pilot was spraying a crop in a valley. During a procedure tum the aircraft sank into the trees.
The surface wind was a light breeze, but there was a strong wind at 2000 feet. Aircraft performance was insufficient to outclimb the sink rate.
BAS! recommendation
An article should be published in the ASD on the dangers of flying near mountain ranges· in strong
wind conditions.
CAA action
Articles have been written on this problem in the past, especially ASD 137 and the special agricultural issue of the ASD. A video is planned on agricultural flying with special emphasis on low level
turbulence.
Cessna 336, 3 August 1988
While in the cruise, the rear engine lost power and smoke entered the cabin. It was found that
cracks had extended along either side of the lower welded seam from the muffler attachment
flange. This had resulted in separation of a large section of the left exhaust stack.
BAS! recommendation
The CAA should r emind LAMEs of the importance of performing thorough inspections on exhaust
systems and repair defects immediately.
CAA action
A CAA investigation is still proceeding. If it is determined that cracks were present but undetected
during maintenance, stronger action than that proposed by BASI may be instigated.
CAIR office contact (office hours)
Canberra
(008) 02 0505
vi /Aviation Safety Digest 140
Aviation Safety Digest 140 / vii
�Aviation Safety Digest
-
140
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How far should
passenger
briefing go?
My inlaws, sitting right at the back, started
showing signs of panic because of the actions of
this passenger. My wife spoke up and calmed
them down and prepared them for a quick and
orderly exit when the word was given. Meanwhile, the smoke had stopped and my 'front
passenger was still trying to get the impressions
of various instruments off his face. All of this
took place in about 10 to 20 seconds from start
to finish and the fire brigade turned up soon after.
DAP(E)
09.03.89
04.05.89
DAP(W)
06.04.89
01 .06.89
This incident raises certain questions and issues
for me, the first of which was to get hold of
Australia's latest 200 metre sprint gold medalist
and debrief her (although other more unattractive thoughts did cross my mind). This debrief
included:! . What if there h ad been some flames? Opening the door would have allowed more fuel (i.e.
oxygen) to the fire.
AGA 0-1-2
05.05.88
04.05.89
Aerodrome Diagrams
06.04.89
01 .06.89
Pilot Contribution by David Shi/ston
* ERS A
09.02.89
04.05.89
AIP (book)
15.12.88
04.05 .89
VFG (book)
15.12.88
04.05.89
A IP/ MAP
15.12.88
29.06.89
VFG/MAP
15.12.88
29.06.89
DAH
15.12.88
29.06.89
II dates quoted are effective dates
*
Note: CLASS T & CLASS
TT NOT AM ARE TO BE CONSULTED
WHEN USING ANY OF THE ABOVE DOCUMENTS
ISSUE: 5
DATE: 06 APR 89
viii / Aviation Safety Digest 140
ECENTLY I was the pilot in command of a
C-210 flying family and friends to Brisbane
for EXPO 88.
3. Did s he know where she was running to? Did
she look for other traffic, i.e. other taxiing aircraft or ground vehicles? Was she aware that
the prop was still spinning? The answer to
these questions was no.
Preceding the trip I briefed my passengers with
the do's and don'ts (as per CNO 20.11-14) then
asked if anybody had any questions, and after
the usual 'where are the parachutes' and 'is
there still time to walk' etc, I settled down to
the workload and to flying which resulted in a
smooth uneventful and enjoyable flight.
In brief, (actually I talked to her for well over
an hour) she did panic as her ignorance with
aircraft led her to believe t hat it was every person for themselves (despite two previous
briefings) and that the fuel tanks were about to
explode (she thought the fire was coming from
the engine).
Before starting the return leg three days later, I
briefed the passengers. With everything looking
good, we were cleared to line up. I applied
power and moved forward.
So, how far should you go with passenger briefing? Should you brief them on the difference
between engine fires and cabin fires? Should
you brief them for every possible situation that
could arise? Perhaps you should 'just carry a
gun and shoot the first person who panics!'
People like our new gold medalist are not only a
danger to themselves but to everybody else, as
panic breeds panic.
Suddenly there was a foul smelling smoke pouring into the cabin from under the right hand
side console (where the front passenger sits).
Within a second or two it was non-VMC in the
front of the cabin. As I contacted the tower
informing them there was smoke in the cabin
and that I was shutting down and evacuating
my passengers, my front passenger had his
head under the console with fire extinguisher at
hand and reported 'no flames '.
New document replaces AGA 3 & AIP/ERS
2. What would have happened if she had
knocked the front passenger unconscious when
she pushed the back of his seat forward, and
by opening the door the flames caught on? He
would have received bad burns at least, as it
would have taken time to run around to his side
of the aircraft and probably require more
strength than I possess to lift him out.
Just as he stated this (I was turning everything
I could find to 'off') I saw out of the corner of
my eye his head smash involuntarily into the
the dash. He tried to straighten up with a
pained expression upon his face as the door
flew open and the passenger who was previously sitting behind him was 200 metres
down the strip before a word could be said.
(The prop was still spinning.)
I would especially like to thank my wife and
my mate who sat beside me (hope the face gets
better soon) who both played a responsible and
co-operative passenger role. Also a big thank
you to the fire unit and safety officers at Brisbane Airport who were so quick to be on the scene.
Unfortunately, it is impossible to predict who
will and who will not panic in any given situation. Your passenger brief could become so
long you never get off the ground and, in any
case, the passengers will only retain a fraction
of it. Stick to the major items, tell them who is
boss and try to exude masses of confidence during the emergency 0
�....
Aviation Safety Digest
140
Aviation Safety Digest
140
'Laverton approach, Tango two four is three
zero miles southwest of Laverton at four two,
cruising four thousand, estimate Point Cook at
... aah ... (expletive deleted)'.
9. If the ground station says 'Good morning' or
whatever, then respond, but don't you start
the pleasantries.
Some
suggested
'rules' to help
improve our R/T
procedures
Pilot contribution by Senja Robey
10. Always report leaving an assigned level.
Remember that being told to make a visual
approach is a clearance to leave an assigned
level when ready.
11. When making an en-route frequency change
many pilots give all sorts of details. If you
check on the correct phraseology you 'll no
doubt be astounded at how incorrect you've
been.
As an Air Force transport pilot with a whole
crew, including a co-pilot and navigator to
help me, I would still write out any lengthy or
little used transmissions. It is easy lo have a
plastic covered page made up so you can
quickly write in the details. The risk is high
you may forget a detail or confuse the numbers
you jot down if they are not written in a logical
manner.
12. Do you really know how to correctly use a
t ransponder ? Incorrect use makes life hell
for the air traffic controller.
13. If you don't understand an instruction don't
h esitate to say 'Say again'.
14. If t h e ground station speaks too quickly
then don't be afraid to say 'Say again,
speak slower'.
1. A im to be professional, even if you are a
student.
2. Hold the microphone correctly.
3. Don't shout - s peak normally so others on
the frequency a ren't blasted out of t heir
cockpits. (otherwise they turn down the volume a nd miss ground transmissions.)
4. Don't acknowledge an acknowledgement t h is can go on all day.
5. Preface all transmissions by your call sign
- however tempting it is to s imply a nswer
the question.
6. If you can 't correctly give standard reports
(departure, full position, inbound etc.) 'off
the cuff' then use a crib sh eet under plastic
with spaces for times, heights and places
etc. and r ead it off (until sufficiently practised and skilled to manage without the
crib). Then no-one will know you're not yet
the Pro you're going to be.
For standard phraseology refer VFG Section
28 - Communications .
7. Know what to read back - assigned levels,
transponder codes, clearance limits, a level
requirement or restriction.
8. On VHF, address the ground station by
name only on the initial contact. When
using HF it is normally necessary to identify the station being addressed each t ime as
there may be numerous ground stations
monitoring the same frequency.
Every rule has an exception and when
transferring from SMC to the Tower frequency (or vice versa) only give your call
sign , rather than firs t addressing them by
name as they are sitting beside each oth er
at the console and exp ecting your call, probably with R/ T space at a premium, so don't
clutter it with unwanted transmissions.
It was late 1965 and I was almost home from
my first solo cross country in a Winjeel. My
feelings of pleasure al a successful NA VEX
quickly disipaled when I blew this radio call.
Ever since, I have gone through in my mind
what should be said before saying it.
15. The phrase 'This is', was dropped ages ago.
16. 'Affirmative' has been replaced by 'Affirm'.
Strange, but true!
1 7. 10 is 'One Zero', not 'Ten' a nd so on.
18. If you want to give Full Position Reports so
'they' and 'everyone' w ill know w her e you
are in the event of a dire emergency, then
for goodness sake submit a formal flight
plan w ith ALL your details rather than
using the excuse of being in too much of a
hurry, s imply not knowing how or being too
lazy and going NOSAR. Did you stop to
think t hat when you pipe up with departure
and full pos ition reports whilst NOSAR t he
flight service officer, who has no deta ils on
your flight, starts a witch hunt to try and
find where in the system things have got
lost. This can be very time con suming and
very COSTLY.
19. Do you know the CORRECT procedures
relating to Departure Reports and Listening
Watch wh en leav ing GAAP aerodromes on a
travel flight? Refer to VFG 61.7.
20. Imagine the busy controller's frustration at
the following pilot response:
ATC
'Alpha Br avo Ch arlie, are you the
first or second a ircraft at the
holding point?'
PILOT
'Alpha Bravo Charlie.'
If you don't understand t he question then
ask, 'Say again'.
21. When the Tower frequency at GAAP aerodrome is very busy you may not be able to
report 'downwind' at th e appropriate place
(when abeam the upw ind t hresh old). No
great h assle, but when you do get the call
in , stipulate where you are e.g. mid
downwind, late downw ind, turning base etc.
Heard recently in similar circumstances a
solo student on short final blurting out •...
downwind, touch-and-go' . There must be a
lesson here for instructors .
22. Try and follow what is being said between
t he ground and other a ircr a ft , particularly
in busy control zones so th at you can anticipate what may be said to you, the reby making it easier to understand and comply.
23 . We all know we must not tran smit over
another person's message, but frequently a
pilot's acknowledgement of a controlle r's
instruction is lost by an over transmission,
leaving the controller in doubt as to
whether his/ her instruction was received
and understood. Make sure that the previous transmissions are complete.
24. How many have heard the call ' . . . returning to base'. Makes you wonder what
t hey've been up to at t hese uncontrolled
aerodromes.
With such a cheat sheet it is easy to say
'Charlie A lpha Alpha departed zero seven,
tracking zero seven zero, climbing to seven
thousand '. Imagine if you don't often get to fly
out of your local area and you simply jotted
down a series of sevens and zeros; might easily
get lost in the middle of your transmission.
Even though I have always (almost!) made a
habit of writing down my transmissions, I have
used abbreviations. For example, there were
certain routes I flew regularly and, for these, I
needed only to jot down the numbers in
sequence, ensuring I had crossed out all, nonpertinent information. In that way I could
write 10, 140, and 30 and say 'Charlie A lpha
A lpha was Cooma one zero, flight level one four
zero, Livingstone three zero' (assuming I had
clearance).
But i t does get more complicated. No longer an
Air Force pilot, I have learnt quickly the difficulties many of us have in finding the money to
fly oft en enough to stay current.
I fly so infrequently that I j ot most of it down
most of the lime, particularly if numbers with
heights, times and tracks are involved. To
avoid the need for ten hands, I prepare as
much as possible before starting engines. Back
in my Air Force days, the firs t thing I would do
after arrival and passenger disembarkation
would be to gel out all the pertinent information for the next leg and put away all of the
last leg information, even if the next leg was
the next day. Part of that preparation included
checking radio procedures for the departure.
Sounds like a h assle? Rather go NOSAR?
Despite radio mistakes, I always go full reporting; its much safer. I think, too, it is much more
professional, even ifyou do make the odd blunder.
Thanks for the reminders, Senja, and the reference to the VFG Section 28. Don't forget the
change in the way altitude is expressed. 'One
fiv e zero zero' is now 'One thousand five
hundred' 0
�Aviation Safety Digest
140
Aviation Safety Digest
140
A detailed description of the structure and
function of the otolith is outside the scope of
this article but in relation to the 'false climb'
illusion, it can be illustrated (see Figure 3) as a
hair which stands vertically with a small stone
at its tip. The base of the hair is inserted into a
sensory cell which conveys information about
the angle of t he hair, to the brain.
The false climb
- a fatal
illusion
- -- - STONE
1- - --HAIR
The 'false climb' illusion occuring
in VFR climb into IFR conditions.
By CADUCEUS
The author of this article flew Spitfires on operations in
World War II and later qualified as a flying instructor. After
graduating in medicine he joined the RAAF as a Medical
Officer and flew Mustangs and Vampires. As Senior Medical Officer at Point Cook in the 50's he was responsible
for aircrew aviation medicine training and high altitude
indoctrination in the decompression chamber. He is still
flying light aircraft for pleasure.
_ 0 MOST pilots the term 'spatial disorientation' conjures up a picture of an inexperi_ en ced flyer, caught out in bad weather and
forced to fly into cloud. Very soon the unfamiliar and conflicting sensations from the body's
' position sense' organs, conflict with the pilot's
interpretation of the aircraft's instruments.
Panic sets in - control is lost - often with
fatal consequences.
This scenario is common enough as a cause of
fatal accidents but t here is also a very subtle
and dangerous form of disorientation to which
even experienced pilots can fall victim. The
wings may be level, and the course steady and
the pilot completely unaware that it is occurr ing. This is the 'false climb' illus ion.
Many accidents are reported in which aircraft,
flown by instrument-rated pilots strike the tops
of hills in cloud or poor visibility, or crash into
the ground after takeoff on dark nights (see
Figure 1). The actual cause of these accidents is
difficult to establish as they are usually fatal
and the aircraft is extensively damaged. An
inor dinate number of such accidents occur
within a few feet of safety and it seems reasonable to presume that many other aircraft, in
similar circumstances, escape the same fate by
a small margin and fly on without being aware
of their proximity to a disaster.
The main culprit in this illusion was found to
be the otolith - an organ w hich forms part of
the inner ear and vestibular apparatus, as illustrated in Figure 2. The otolith has its own
special function - to sense and signal to the
other organs, the position of the head relative
to the vertical. In the absence of visual cues,
this signal becomes a powerful influence on the
balance and orientation of the body. Without
the otolith, it would be impossible to maintain
one's balance with the eyes closed.
_ _ _ _ NERVE
When the head is t ilted backwards, as in Figure
4 , the weight of the stone bends the h air and
t his message is relayed by the sensory cells to
t he brain, where it is interpreted as a backward
t ilt. If the head is held vertical and is accelerated forwards, the hair will bend in a similar
fashion owing to t he inertia of the stone. Thus,
both tilt and acceleration produce the same
r esponse by the otolith. However, the br ain is
unable to differentiate between these responses.
'Acceleration' is read as 'tilt' .
HEAD TILT
ACCELERATION (1 g)
CONSTANT
GRAVITY 1g
.
NO HEAD TILT
IMPOSED
ACCELERATION
INERTIAL FORCE~
DUE TO
ACCELERATION
1g
RESllJANT
, . 19
IDEALISED DEFLECTION OF THE OTOLITH ORGAN
Figure 4
Figure 2
acceleration of 0.2g if sustained for several
minutes, is sufficient to produce this illusion.
After a brief acceleration, s uch as a catapult
launching (5g for 2-3 seconds), the apparent
nose-up illusion takes a minute or s o to die
away. Similar but opposite sensations are produced by tilting the head forward or by decelerating the subject.
• Takeoff - night or IFR.
• Overshoot (missed approach).
• Climb from VFR into IFR conditions.
Figure 3
GRAVITY 19
VESTIBULAR APPARATUS
It has been shown that a relatively low linear
There are three common situations in which the
'false climb' illusion may occur. In these cases,
it is assumed that visibility outside the cockpit
is absent or at least inadequate for visual
flight. These situations are:
Figure 1
In Britain during World War II, an investigation
was carried out into a series of accidents which
occurred at flying training units in w hich aircraft taking off on dark nights, crashed into the
ground shortly after leaving the runway . No
obvious cause of these accidents was found, but
eventually investigators concluded that the
p ilots were deluded into thinking that their aircraft was climbing or at least in level flight,
when in fact the aircraft was descending. The
author called t his phenomenon the 'false climb'
illusion.
steeply. Owing to lag in the altimeter and VSI,
the loss of height may go unnoticed until it's
too late to avoid ground contact. (By the way,
this illusion is known as the 'somatogravic
illusion' in the U.K. and the 'posturogravic
illusion' in the U.S.)
'
If tilt and acceleration ar e experienced simul-
taneously, and in the same direction , the
interpretation is that of a much steeper tilt.
This is the explanat ion of the 'false climb'
illusion. When a pilot is subjected to climb and
forward acceleration at the same time, and
deprived of external visual cues, he experiences a strong sensation of a steeper than
actual climb . It is t his illusion which tempts the
pilot to lower the nose of the aircraft. This
increases the forward acceleration component
- and increases the illusion of climbing
The takeoff or overshoot, on dark nights or IFR
conditions, are clear cut situ ations where the
pilot is set-up for the illusion.
·During a climb from VFR into IFR conditions
the illusion can be compounded by turbulence,
t urn or an AH that wasn't quite erect. This
s ituation may well have been r esponsible for
many accidents where aircraft have cr ashed
into hillsides . Usually the decision to climb has
been dictated by deteriorating weather conditions and is unplanned - t his is enough to
cause some anxiety and to interfere with correct decision-making. As the aircr a ft is already
flying at r edu ced power and airspeed, the fullthrottle climb will produce the illusion.
Summary
All pilots irrespective of experience or skill are
s usceptible to the illus ion.
It is particularly letha l as the effect is subtle
and there are few cues to what is going wrong.
The effect is an apparent positive climb a s
sensed by the body and perhaps even a nose-up
attitude indicated by the AH, wher eas in fact
the a ircraft may be descending. Eventually the
performance instruments will show the descent
but perhaps not in time to avoid impact.
The bottom line is to anticipate the illusion and
ignore it, to establish a pos itive climb attitude,
to hold that positive pitch attitude and to check
the per form ance instruments for confirmation
of t he climb - then adjust t he attitude to
maintain the optimum climb airspeed. (In some
situations this may be the speed for best angleof-climb r ather t han best rate-of-climb. ) 0
�Aviation Safety Digest
140
Dear Sir,
In 1978 I flew a C206 to Mascot on a Saturday
to pick up three American friends who had just
arrived in Australia.
At that time I had about 960 hours most of
which were on C206, C210 , Piper Lance plus
182s. I was no stranger to Mascot, as for 18
months prior to that I'd flown into and out of
Mascot once or twice a week on business. After
a ll necessary clearances I asked for a departure
via Runway 07's taxiway Hotel. This was
granted, I called ready and was told to line up,
which was done. My front seat passenger (a
Delta Airlines employee in the States) was a
very big man. I sat for about 50 seconds and
after having heard nothing called ready twice.
No answer.
I looked be hind for traffic and was horrified to
see an Australian airlines 727 executing a go
around and the Boeing passed over me at about
100? feet. Radio failure , and in 1978 no SSR.
As I reached to turn up the volume on the ADF
I noticed that the transmit (VHF) button on the
top of the dashboard (This was a 1976 C206)
was NOT depres sed. I pressed it and immediately called ready again and a not too happy
controller cleared me for takeoff probably
thinking all private pilots are a menace. What
h ad happened, as I taxied to line up , was my
passenger had bumped the row of buttons with
his elbow hence the te mporary radio failure.
My apologies to Australian airlines and the
boys in the tower. I pride myself on checking
everything. That was something I'll never forget to check again.
Yours faithfully,
Geoff Westbury
Small cockpits and passengers in the front seat
can be a problem. I r emember a RAAF Iroquois
spreading its skids about 20 years ago when a
passenger, while getting into the front seat,
pulled up on the collective with the engine at
idle. These situations demand a good brief i ng
and eternal pi lot vigilance.
Dear Sir,
I had not many hours under my unrestricted
belt, so as an over-abundance of reasons were
at hand I decided to take my w ife flying. Our
main destination was Cairns but to gain hours I
thought we'd take in a trip to 'The Tip'. From
Archerfield to Horn Island and back would beef
up the log-book and hopefully would serve as a
good learning experience.
Expecting tropical splendor at T.I., and finding
little but dollar hungry locals we decided to
leave ASAP. I w asn't confident enough as yet to
try island hoping which I'm told is a magic
experience, so we rang Horn Is. to seek fuel.
Yes, $50 opening fee . Well, it was Sunday ...
Aviation Safety Digest
140
Checking charts showed a return via Coen was
O.K. They had to travel 30 miles to open and it
was only $35 and they took a cheque! Nice people.
The last leg was Cairns via Cooktown. Things
were wrong from the start. I wasn't lost, but I
just couldn't get the sums right: I couldn't pick
the wind.
Then when I decided to make the best of w hat I
knew, the ranges ahead of me were shrouded
with dark cumulus. So I diverted left toward
clear sky and the coast which was fine. I spotted what I thought was Lizard Island and hearing a chopper making for it I made a ' Hello, I
know you're over there and I'm over here' call.
I thought I was twenty miles from it. I was in
fact looking at Howick Island and getting my
sums all wrong again. Suspicions started
looming in my mind, bells started ringing; I
looked at my fuel. My poor cockpit management
had not detected an assymetric feed. The left
tank was almost empty . A change of tanks and
thinking ahead to what might hav e happened if
things had gone very quiet at some later
moment, even now r aises a sweat . What it did
was distract me from navigating properly.
The weather ahead was looking nasty , but ,
looking at the full fuel tank and at that stage
feeling comfortable flying in clear skies 'knowing' where I was, I fell into the trap of letting
the future take care of itself.
Cooktown is a lovely place, but t he aerodrome
was thirty kilometers or so from the city . Having spent hours hitching rides to and from the
place two days previously, it was a priority
NOT to go there. So it was Cairns and a welcome bed or bust. Well it was almost bust .
Barrelling on, I was dropping altitude, to stay
under the cloud. I picked up Cooktown NDB, or
so I thought. Knowing NDB errors such as
mountain effect, is not knowledge merely to
pass tests. I didn't figure that out at the time.
Incredibly, I started to think my compass was
misreading when it didn't match my DR and the
ADF.
Blind faith and knowing if I looked backwards I
could still see clear air I kept going, getting
lower and lower. When I was at five hundred
feet, and the wings were skimming the cloud
base, some mis-interpretation of meteorological
lore urged me to turn west.
I ploughed into cloud and rain and for two or
three insane minutes I was heading towards
mountains, blind. For some reason I thought it
would be clear over the beach and I could follow that to Cairns. Out of the corner of my eye,
while keeping a concerned yet confident look on
my face , I could s ee my wife looking terrified. I
think it w as her absolute confidence in me,
even though she was terrified, that made me
r ealise how bloody stupid I was being.
If she hadn't been t here I might h ave done
something ev en more stupid. I think back now,
r emembering the st ate I was in, and if the
phr ase ' if you inadvertently get clouded in ,
climb' had popped into my h ead, I probably
would have done that and killed bot h of us on
the side of a mountain .
God and sens e finally won t h rough and I turned
180 degrees and headed ea st. My wife told me
later that that turn w a s what almost made her
crack. She had lost all sense of d ire ction and as
we could only see cold w ater below we were
virtually flying blind. I w asn 't going to go any
lower as memories of being two hundred feet
off set altitude while t raining w ere still fresh in
my head, I w anted as much space between me
and the w ater as possible. So I doggedly flew on
into sunshine.
From that point on it was as if there was a new
pilot in control. I made the correct calls, found
Cape Flattery where I figured it would be, put
down w ith plenty of runway to spare.
When my wife stepped on firm ground s he cried
with relief. If I h ad been less of a fool, I w ould
have too.
Yours sincerely ,
Paul Neilsen
We have sent you a complimentary cop y of our
n ew video 'Going Nort h - A Pilots Guide to
Remote Nav igation'. It contains a lot ofuseful tips.
Dear Sir,
A 't w ang' w as felt in the st ick of a Super Cub
on downwind. The aircr aft remained controllable and w a s landed wit h some difficulty w ith
a strong crosswind from the left . Something felt
wrong with the stick, and much us e of brakes ,
rudder and throttle was needed t o control the
ground roll. After the landing an inspection of
the fuselage and tail surfaces revealed n othing
unusual but then it was discovered that t he left
rear sliding window panel w as on t he rear s eat,
angled between the rear s eat belt buckle and
t he stick. The knob on t op of t he stick pre vented use of the le ft rear t hird of stick position. No amount of 'jiggling' the stick w ould
dislodge the window panel. The p anel w as
replaced in posit ion in its slides and secured .
The experience of hundr eds of previous landings in tail wheel aircraft w a s a factor in the
s afe landing of this incident .
Anon
A good reason f or a careful pre-flight of all
pan el secur ity.
Dear Sir ,
I have read several times now, w ith interest ,
the a rticle by Brian Bigg, on the Sydney training area, and some of his experiences. As one of
t he many w ho use this area, I can do nothing
but agree with his article. However, I feel, as
do others I have spoken to, that maybe , just
ma ybe , you have printed this article to generate
discussion on h is views and experiences.
Most of my flying is out of Hoxton P ark, as was
all of my training, and I agr ee t hat it may be
'Raffer ty's Rules' there on occasions, especially
with s ome of the establishmen ts ther e appearing t o teach cross country circuits, which makes
a normal circuit difficult to fly. What Hoxton
Par k doesn 't need, however , is on a weekend ,
all the Bankstown students coming over there
for s ome circuits away from the h assle of the
tower. As Mr Bigg said, Hoxton P ark is busy
enough without t he Bankstown boys a nd girls.
The main r eason for this let ter is his remarks
on a circuit ent ry at Hoxton Park, wher e it
would seem he had a bit of a scare. Allow me to
maybe point out where Mr Bigg went wrong.
The Aerodrome Directory says of Hoxton Park,
'elev. 135ft', which means that correct circuit
height of l OOOft above ground lev el is l135ft .
We use llOOft which would put h im at an altitude of 1250 + 135 = 1385ft. Pretty high circuit
for Hoxton Park, when the locals are using
llOOft. Even if his 1250 was altitude, it is st ill
a pretty high circuit . Aircraft over fly t he circuit at 500ft above circuit height, w hich at
HOX. w ould be 1600ft, s o if he was at 1385ft,
and an aircr aft overflies at 1600ft, h e is righ t,
ther e isn't very much dist ance between the t wo
aircraft . I would suggest t hat the oth er aircraft
was overflying before circuit entry. If t hat is
t he case, I would s uggest that the one who
should have been on t he receiv ing end of the
stones, is Mr Bigg. Maybe it is just as well th at
he has moved t o less busy r egion, for all t he
Sydney area pilots sake.
As for -his formation stalling out in the t raining
a rea, w ith a CFI no less, my God! What were
they looking at during the 360 degree t urn,
which should be carried out before pract ice stalls.
Hopefully we all learn from mist akes , whether
t hey be our own or ot hers.
Yours fait hfully,
Peter Eaton
1385ft does seem a bit high for Haxton Park. A
good lookout, as described by Mr Bigg, is most
important. Ev en with a clearing turn it is sti ll
possible to miss other traffic, especially if you
d o not look above you. And, y es, all the articles
are printed in the hope of generating
discussion.
�- -,
Aviation Safety Digest
140
Aviation Safety Digest
140
Beyond the call
... of duty
by Paul Middleton
'Aenno forty-eight, dunnomate, never heard of it, is that a
replacement for 1080?'
A
S COMMERCIAL pilots, how many of us
have hea rd conversations like that? Certainly ANO 48. 1, or nowadays CAO 48.1
'Pilot Flight Time Limitations' , is one of the
hardest to read, most maligned, vilified and
probably disobeyed set of requirements in the
Auth ority 's bag of t r icks. Yet, the standards
and requirements laid down in that order are as
near to correct and proper as any general
safety requirement can be. The Order has
nothing to do w ith industrial agreements; the
requirements are there for no other reason than
the protection of the passengers, the crew and
the public on the ground. Unfortun ately it is an
area which is open to abuse by the industry
and the pilot, who, while certainly not
blameless, is often t he ham in t he s andwich.
Here is a short story from the grey distant past.
I h ad finally wangled myself a job as a commuter pilot and felt very smug indeed. No more
round and r ound the circuit; no more charter
waiting until after dark at some cattle sale on a
black ALA; nice big aeroplanes, scheduled services, a jacket with three gold bars and even
days off - life was indeed good. The pilot rostering was handled by a pilot committee and
was all fair and legal. We flew ninety hours a
month, all scheduled with about 90% loadings
- what a difference to the charter game!
On the weekend of my story, I was rostered for
the normal southern run, something like;
SY-NW-MRY-NW-SY then off to TUM and CTM.
The difference on this occasion was that
instead of twiddling my thumbs in a motel unt il
Sunday arvo for the flight back to Sydney, I
would take a charter group to t he north of the
state and return next day in time for the scheduled run. Looked good.
Saturday morning u p at 0515, shave etc., quick
brekkie, quick trip ahead of the traffic across
the city to KSA. Grab the weather, toss in a
plan, up to the light aircraft park, quick daily
(company policy always fueled an d oiled the
aircraft at the end of the day) taxi down to the
terminal getting my airways clearance on t he way.
OK, sounds fine , where's the catch? Back at t he
terminal the company representative (ticket collector, baggage handler ) points out t h at he has
a message for me from the Chief Pilot who was
passing through heading to point s unknown for
a few days. Open the note. There has been a
foul up w ith my charter, it's a pick up out of
Temora, up to the wedding and back again all
today! Blood pressure rising! Southbound passengers are already boarding - expletive of
four letters - into the seat, doors close 0700
on time. Arrive Nowra, south easter has push ed
some muck in so I sta rt my day w ith an NDB.
At least with it being a weekend the navy are
all somewhere else and I don't have t o worry
about them. Passengers out, hand out the luggage, off to Moruya. Weathers a bit better h ere
so a visual approach , load up and back to
Nowra, only a half NDB that time, load up
again back to West Pymble for an ILS into Sydney.
If you do the sums its an eighteen hour duty
day and about nineteen hours on the run. There
is not a shadow of a doubt that by the time I
was making that last NDB at Temora I wasn't
anywhere near the ball, let alone on it!
So thats it, but what do you do in that sort of
situation? Pilot jobs were extremely hard to
come by, ones in commuter operations even
harder still. I had the mandatory wife and
couple of kids an d General Aviation was my
life. The last thing I needed was a reputation as
a pilot who wouldn't 'work' . If you refused to
fly or lost a passenger then you were out on
your ear and there were fifteen pilots beating
the door down wanting your job.
There is no doubt in my mind that the task I
carried out was 'rostered' even though it didn't
show up that way on the roster sheets. The
charter passenger spokesman w as adamant they
had always had a single day t r ip booked and
hadn't changed any of the detail. I believe him
and have from that day held the conviction that
the operator set me up knowing that I was in a
situation where I had to finish the job.
Let s have a look at the options: there was no
contact numbers available to us at Mascot to
talk to the charter group, and company representatives with any authority were conspicuous by their absence.
Option one - try to get our rep. (baggage
handler) to try to contact somebody in authority (tried that - failed).
Option two - complete the scheduled legs as
per normal and refuse to leave CTM. Chart er
passengers in the lurch - me sacked.
Option three - pick up the charter passengers,
do first half of charter and refuse to fly back
until I had a rest period (ten hours) but that
would mean an overnight anyway. Unhappy
passengers - me sacked.
I don't know what the answer is, but I do know
that the operator breached CAO 48.1.1.5, 'An
operator shall not roster a pilot for a tour of
duty in excess of 11 hours' . For me I certainly
busted CAO 48.0.1.4 which in part says that if
the pilot is suffering from fat igue he shall not
fly. In r etrospect I placed the passengers, the
aircraft and possibly some of the residents of
Temora at risk.
My justification at the time was that I needed
to keep my job and my reputation as a person
who got the job done. However fifteen years
later looking back in the cold clear light of day
what is the difference between what I did and
somebody who steals to feed his family? At
least the thief is not putting other peoples lives
at risk.
I would like to hear your thoughts on the subject, so take ten minutes off and drop the editor
a line. If we get some good responses we possibly can analyse them and I might even give
you the Senior Examiner s point of view D
How well do you know your GAAP procedures?
General Aviation Airport Procedures cater for
high density operations in VMC in General A viation control zones. When these procedures a re
followed correctly, airport traffic flows q uickly
and safely . Problems arise however when,
either through lack of knowledge or understanding, the procedures are incorrectly
applied. How well do you know your GAAP
procedures? Try this multiple choice test and see.
Right, now what about this bloody charter mess
- no chief pilot, no senior pilots in captivity,
and managers don't w ork weekends do they?
Western passengers are boarding so off we go
to Tumut and Cootamundra. Nobody at Coota
knows anything and its nearing the charter
pick-up time. Quick fuel up and off to Temora
to load the wedding party.
1. In a General A viation control zone in VMC
who is resp onsible for aircraft separation?
I won't continue to bore you with the flight
detail but w hile the passengers were at the
wedding I had to reposition the aircraft for fuel
and then return to pick t hem up. The finale is a
limp, r ed eyed pilot doing an NDB down to
minima at Temora at 1145pm as in 2345 and
finally buttoning the beast up at h alf-past
midnight.
(a) Air Traffic Cont rol in all cases.
(b) The pilot in command in all cases.
(c) Air Traffic Control provide runway separation and the pilot provides all other
separ ation.
(d) Nobody is responsible for separation.
2. In a General Aviat ion control zone when
VMC do not exist, who is res pons ible for aircr aft sepa ration?
(a) Air Traffic Control apply positive
separation.
(b) The pilot in comm and.
(c) Air Traffic Control provide runway separation and the pilot p rovides all other
separation.
(d) Nobody is responsible for separation .
3. The VMC minima for General Aviation cont rol zones is:
(a) Ceiling 800 ft; and visibility 4000 meters.
(b) Ceiling 1500 ft; and v isibility 5000 meters;
or as determined by ATC.
(c) Ceiling 1000 ft; and visibility 3000 meters.
(d) Ceiling 300 ft; and visibility 1200 meters ; or
as determined by ATC.
�Aviation Safety Digest
140
Aviation Safety Digest
140
4. In addition to the general information on
GAAP in AIP RAC/OPS 1-61/64 and VFG Section 28, where would you find supplementary
operating procedures applicable to specific General Aviation aerodromes?
(a) Route IFR Operating Limitations (LIM).
(b) En-Route and Aerodrome Special Procedures
(SAP).
(c) Aeronautical Information Circulars CAICs).
(d) Departure and Approach Procedures (DAP).
5. Which of the following are a pilot's responsibilities in a General Aviation control zone?
(a) To sight and maintain separation from other
aircraft operating in the General Aviation zone.
(b) To comply with ATC instructions while
ensuring separation is maintained from other
aircraft.
(c) To immediately advise ATC if unable to
comply with a control instruction.
(d) To advise ATC if unable to sight other aircraft notified as traffic.
(e) Both (b) and (d).
(f) All of the above.
6. Is an airways clearance required prior to
entering a GA control zone?
(a) No in all cases.
(b) Yes, unless the pilot is returning from the
training area.
(c) Yes in all cases.
(d) Only in IMC.
7. Operational terminal information required
prior to departure or arrival is obtained by :
(a) Asking the MET officer.
(b) Requesting the information from A TC on
initial contact.
(c) Dialing up the ATIS broadcast.
(d) (b) if unable to comply with (c).
(e) A waste of time and not required.
8. What is required of a pilot if instructed to
'follow th e Cessna downwind'?
(a) The pilot is required to follow the exact
path of the preceding aircraft.
(b) The pilot is required to sight and identify
the preceding Cessna and regulate circuit s peed
and approach path to achieve correct circuit
spacing.
(c) The pilot is only required to sight the preceding aircraft.
(d) The pilot has no requirement to either sight
or follow the a ircraft.
9. When parallel runways are ut ilised for simultaneous contra circuits and runway right is
nominated what is the circuit direction?
(a) Either left or right.
(b) Left.
(c) Right.
(d) Not s ure.
10. What has been omitted in the following
transmission to BK ground? 'Bankstown
Ground, Romeo Alpha Tango , for Bathurst,
Runway II. '
(a) The runway designator (left or right).
(b) The ATIS designator.
(c) The SAR status (full SAR/ SAR time/ No SAR).
(d) Both (a) and (b).
(e) All of the above.
11. Romeo Alpha Tango reports 'ready' while
still well back from the holding point and number four to depart, is there anything wrong
with this?
(a) No, a 'ready' report may be made at any time.
(b) Yes, the pilot should wait until closer to the
holding point.
(c) Yes, the pilot should report 'ready ' when
approaching the holding point and next for
takeoff.
(d) Yes, there is no r equirement for a 'ready' call.
12. Cherokee Alpha Bravo Charlie entering
Parafield control zone at Dam Wall gives the
following call. What has the pilot omitted?
'Parafield Tower, Alph a Bravo Charlie, Dam
Wall, inbound, Received Bravo'.
(a) No information omitted.
(b) Aircraft type omitted.
(c) Altitude omitted.
(d) Both (b) and (c).
13. Are there any mistakes in the following
statement? In VMC, both IFR and VFR category
flights arriving from outside controlled airspace
by day or night shall track visually via a general aviation appr oach point.
(a) The statement is true in all respects.
(b) The statement is only applicable to VFR category flights.
(c) The statement is only applicable during the
day.
(d) There is no requirement for either IFR or
VFR category flights to track via General A viation approach points.
14. Where would you find the General Aviation
approach point mentioned in question 13
specified?
(a) AICs.
(b) DAP.
(c) ERS/ SAP.
(d) LIM.
15. The ATC instruct ion 'Join upwind':
(a) Permits entry to the circuit upwind at circuit height, clear of the opposite circuits;
(b) Authorises entry into the opposite circuit on
upwind leg;
(c) Requires entry into the circuit at 1500 ft
QNH on upward leg, clear of the opposite
circuit/ airspace; or
(d) Authorizes entry to the control zone at 1500
ft QNH, tracking upwind parallel to the duty
runway centreline on t he active side of the circuit, and clear of the opposite circuit airspace.
16. The ATC instruction 'Overfly' :
(a) Authorizes entry into airspace associated
with the opposite circuit and circuit height;
(b) Directs aircraft to overfly the aerodrome at
1500 ft QNH, and, where parallel runw ays are
in use, authorises entry into the airspace associated with the opposite circuit;
(c) Allows the pilot to enter the circuit of the
opposite airspace after overflying at circuit altitude; or
(d) All three of the above.
19. When departing a General Aviation control
zone a pilot may t rack by the General Aviation
approach points and associated VFR routes. Do
you agree with this statement?
(a) Yes. There is nothing wrong with t racking
via these points.
(b) No. A pilot shall track well clear of th ese
points.
(c) Yes. However caution must be exercised to
watch out for arriving aircraft.
(d) No. Because t here is no such thing as a General Aviation approach point.
20. What does a red flashing light from the
tower mean to an aircraft on final?
(a) The pilot is authorised to land if satisfied
no collision risk exists.
(b) It has no significance.
(c) The aerodrome is unsafe. Do not land.
(d) Give way to other aircraft and continue
circling.
21. What should a pilot do if unfamiliar with
operations at a particular GAAP Aerodrome, or
not fully understanding of an ATC instruction?
(a) Give up flying as it is all to hard.
(b) Bluff his/ her way through, after all what
could go wrong?
(c) Ask ATC, or include this information in the
Flight Plan (ATC's are there to help).
(d) Give up flying into GAAP Aerodromes.
17. A downwind call should be made at a position abeam the upwind thres hold. If, due to
frequency congestion, a pilot is unable to make
this report what s hould he/ she do?
(a) Disregard the call completely.
(b) Report on base inst ead.
( c) Report either mid-downwind or
late-downwind.
(d) Nothing, as the statement is incorrect and a
downwind call is not required.
18 . When a go-around has been initiated a pilot
s hall climb to circuit altitude, position the aircr aft on the active side and parallel to the
nominated duty runway, while maint aining separation from other a ircraft and follow ATC
instruction where iss ued, otherwise re-enter the
circuit from upwind. Is this a true statement?
(a) No. The pilot should position the aircraft on
the dead side of the runway.
(b) No. The pilot is not required to comply with
A TC instructions.
(c) Yes. The statement is correct in all respects .
(d) No. There is no requirement t o climb to circuit altitude.
Now check your answers and see how well you
have done.
1 (c), 2 (a), 3 ( b), 4 (b), 5 (f), 6 ( c) ,
7 (d ), 8 (b), 9 (c), 10 (e), 11 (c), 12 (d),
13 (a), 14 (c), 15 ( d ) , 6 (b) , 17 (c),
18 (c), 19 (b), 20 (c), 21 (c).
The purpose of this series of multiple choice
questions has been for you to test your knowledge on GAAP procedures. Your score is not
important, what is , however, is the answer to
the question ' How good is my knowledge
really?', and you are the only person who can
answer it.
When was the last time you sat down and read
Section 28 in VFG or RAC/ OPS 1-61/ 64 or consulted ERS/ SAP or checked to ensure your
VTCs were current? Half an hour occasionally
will cost you very little but in the long run may
save you a lot D
�
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140
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1989
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ASD 139
SUMMER 1988/89
�Aviation Safety Digest is prepared by the Civil
Aviation Aulhorily and is published by the
Australian Government Publishing Service. It is
distributed to Australian licence holders
(except student pilots), registered aircrah
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
environment.
Distributees who experience delivery
problems or who wish to nolify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Civil Aviation Authority
· P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There 1s a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C. T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
3
Editorial
y ou said .. .
4
Printed by Ambassador Press Pty Ltd
51 Good Street. Granville, N.S.W. 2142,
AUSTRALIA
f
We would like to thank those readers who took the
_
trouble to complete and return the reader survey
which was included in the Aviation Safety Digest last year.
Dust devils
6
Exams -
8
Life jackets
why bother?
8
Medium-rare and well-done
9
ILS -
13
Some whats and whys
Some like it hot
14
Benchmark safety
16
Ice and water don't mix
18
Mea culpa -
20
Traps for young players
21
a sobering confession
Surprisingly, however, we only received 61 returns from a
distribution of over 40 OOO. This may be accounted for by
the comment offered by one respondent on a photocopy
of the survey page; 'I don't like cutting up my Digests'.
Either that or we could assume that over 39 900 readers
reckon we are getting it right!
Despite the small return, the comments covered a total
cross-section of views. Generally, with only one or two
exceptions, readers found the format, timing and style
quite appropriate. The comments we received about the
content and emphasis of articles were the areas where
readers disagreed significantly. Private pilots supported
the current balance and th rust of articles where the professionals within the industry and those involved with
other aspects of aviation want to see changes to cater for
their particular needs.
We agree. The Digest has to cater for a total crosssection of people within the ind ustry. Therefore, from the
next issue you wil l see some changes. There will be at
least two articles which will specifically address subjects
of interest to the professionals, an article on airworthiness
and one concerning overseas RPT accidents. We also
intend to include a regular quiz so that you can test your
'air mindedness'.
The most common comment we have received in letters
and face-to-face, when the Division has been in attend·
ance at joint CAA/AOPA Pilot Safety Seminars or
Ai rshows, is that readers miss the summary of accidents.
This section of the Digest was always provided by the
Bureau of Air Safety Investigation and now that the Authority has been established and BASI remains as a part of
the Department of Transport and Communications, the
Bureau is producing its own Journal which we are distrib·
uting for them with the Digest every quarter.
Covers
Front. Unique - the only Slingsby T66
Nipper currently flying in Australia.
Owned and flown by Trevor Wright at the
annual Prairie, Vic. fly-in during
September 1988.
Photograph by Steve Small
Mamiya RZ67 Fujicolor
Back. View from the seat many would
aspire to - state-of-the-art displays in
the Coles-Myer HS 125 - 7008.
This photograph by R Ban Semer was an
entry in the last Nikon ASD Photographic
Competition.
The ASD has been in constant production since 1952 and
has always been considered an important element in the
enhancement of aviation safety. The CAA will continue to
ensure it meets the needs of the day and welcomes your
views.
Sea survival
Editorial Assistant:
Graphic Design:
Karen Hutchison
Lesley Boulton
Photographs:
Mike Griffin
David Larkey
Scott Allen
BAS/
TERRY WALLS
SAFETY PROMOTION SECTION
AVIATION STANDARDS DIVISION
© Commonwealth of Australia 1988
ISSN 0045-1207
R85/979(10) Cat. No. 87 1577 8
Editorial
Contents
22
AIRFLOW
P5
PB
P17
P20
Diagrams:
Soussanith Nokham
Kathy Walter
Cartoon:
Soussanith Nokham
�....
[
Aviation Safety Digest
Aviation Safety Digest
139
Dust devils
Bureau of Meteorology
139
In general the dust devils are larger, higher and
longer-lived w hen the temperature is higher and
lapse rate steeper. In the Alice Springs area
small dust devils with diameters less than 10
feet, height less than about 10 feet agl and life
span less than two minutes may occur with
temperatures in the range 18 to 28 degrees.
With temperatures in excess of 35 degrees the
diameters may range from 30 to 100 feet, with
heights up to 10 OOO feet agl and life spans up
to 30 minutes longer.
Particularly long lived dust devils (in the order
of one hour) have been observed in the flat
vegetation-sparse areas such as the Nullarbor
and the north of South Australia.
An active meteorological system such as a
trough evident on Mean Sea Level charts may
cause the dust devils to be larger and also leads
to marked visibility reduction in haze.
Hazardous nature
tr"
UST DEVILS are s mall-scale wind circu~ lations that occur in the arid inland parts
of Australia, generally in the hotter months
of the year. They are generally visible as minitornadoes t hat draw up dust into a swirling
cloud-like formation; however the wind circulation may be present without visible evidence,
and these type of dust devils are especially
dangerous. These latter types of dust dev ils
often occur over grass, or soil 'sealed' w ith
recent rain.
Dust devils may move at speeds of up to 30
knots, but they may stop suddenly, restart or
change direction suddenly.
Conditions for formation
The prerequisites for visible dust devils are a
source of dust, steep lapse rates , high surface
temperatures and us ually light winds within the
boundary layer. The dust must be loose,
although not necessarily thick; the dust devils
may occur where sparse vegetation and scattered trees are interspersed with areas of no
trees or grass. Dusts devils are seldom seen
over salt marshes , well-watered grasslands or
thick forests; small dust devils may occur in the
monsoon forests over Arnhem Land.
Given fairly light winds in the boundary layer,
strong surface heating and the establishment of
a steep lapse rate cause very narrow columns
of rotating air or whirlwinds to form; these
interact and tease the soil particles as they pass
over a dus ty surface. These are lifted, transported and eventually dumped. In the process
the particles are sifted, with th e lightest falling
last. As a dry period of weather pe rsists, the
top soil takes on progressively a more talc-like
texture, ultimately the increased availability of
fine 'talc' allows dust devils to become more
s pectacularly visible.
Dust devils, whether vis ible or not, are a hazard to a ircraft especially during takeoff or
landing. Because the background wind is generally light they produce a sudden impact when
la nding or taking-off. They have t heir greatest
energy near the ground w hen the pilot's attention is concentrated on fl ying t he aircra ft,
r ather than watching for evidence of
whirlwinds. At higher levels their dangers are
generally less, but there is the risk of loss of
control. This risk in flight is greatest n ear the
upper part of the disturbance where the rising
column of air changes its structure by spreading. At this level the aircraft's lift can be affected, resulting in sloppy control responses.
There is often difficulty in accurately gauging
the distance to or from a dust devil because
there is very little scale reference available.
..
Alice Springs
Wind
Suggested flying techniques and
visible clues
Pilots who fl y daily in dust devil prone areas
adopt appropriate procedures to minimise their
impact. To a pilot who has gained experience in
coastal areas, the first encounter with a dust
devil can be frightening. For s uch pilots the following advice is offered:
• Delay takeoff and landing until the airstrip is
clear.
• At operating levels try to avoid going anywhere near dust devils.
• To minimise encounters, whenever possible
confine fl ying to morning hours.
• Watch tall grass movement when landing; this
may provide an indication of any invisible
dust devil.
• A void by at least 2000 feet the region above a
dust devil.
• Always make a powered approach in areas of
dust dev ils.
In dust devil prone areas light aircraft should
be securely pegged down if not parked in a substantial hanger.
Some pilot experiences of dust devils from
Aviation Safety Digest No. 101, 1978.
A pilot was flying a Cessna 172 in the
Cunnamulla area at 10 OOO ft in the cloudless
conditions. The surface temperature was above
38 degrees C and the wind light and variable.
No dust devils were visible at the cruising level,
but many could be seen below. The aircraft was
heavily loaded , with the pilot's wife and three
children as passenger s. The pilot believes he
flew into t h e invisible top of a cauliflowe ring
dust devil: 'In spite of full corrective control
and full power,' h e recounts, 'the aircraft rolled
inverted and was flown out underneath. I could
not climb any higher and was forced to descend
to maintain control' .
•O
30
>O
1130
1145
I
I
I
1200
1215
1230
I
12 4 5
1300
I
1315
1330
I
1345
l
14 00
1415
I
1'30
1445
1500
Time
Record of surface wind observation, Alice Springs airport, 23
October 1987, showing a gust of 55 knot coincident with a dust
devil passing over the observing instrumentation.
At Nanda an aircraft was landing into a gusty
wind of 20 to 30 knots. Small n umbers of scattered dust dev ils were v isible a nd the s urface
temperature was about 38 degrees C. 'At the
last moment,' t he pilot r elates, 'a dust devil several hundred feet high crossed the landing path,
slewing the aircraft first one way then the
other, and rolling it on to each main landing
wheel alternately. The whirlwind was one of a
group of t hree, and was invisible until it moved
on to an ungrassed area and picked up dust. At
one point t he aircraft was lifted clear of the
ground at or just below stalling speed - ver y
unpleasant!'
At Richmond, a Cessna 150 was taking off in
almost calm conditions. The temperature was
41 degrees C and the sky was cloudless. At a
height of about 100 feet it encountered a whirlwind. (The pilot believes this was in the process
of forming at the time - it was not visible as
he was taking off but it later became a very
large dust devil.) The pilot's first indication of
the encounter was a very sudden gain of about
200 feet in height. But then the upward motion
stopped so suddenly that the pilot was flung
against the restraint of his seat belt and
bumped his head against the cabin roof. At the
same time the airspeed indicator needle shot up
into the red arc! Though buffetted, the aircraft
remained controllable. The pilot considers the
only real dange r was the effect of the gust on
the aircraft's structure as the a irspeed indicator
showed an increase of some 60 knots. Had the
whirlwind been fully developed , he feels that
structural overloading could have resulted in
airframe failure.
Another pilot said he had seen the roofs of two
houses at Richmond lifted by dust devils and
the sheets of galvanised iron carried half a
mile. He believes that light aircraft would certainly be lifted if not pegged down. On one
occasion a Cherokee six tied down at Windorah
with four l 6mm diameter ropes was tipped on
to its back when a whir lwind snapped two of
the ropes. Another pilot told of a Piper Colt
which had just been wheeled from a hangar in
the course of a 100 hourly inspection. Before
those pushing it had time to walk back into the
hangar, a whirlwind had struck the air craft,
picked it up and dropped it again upside down,
damaged almost beyond repair D
Alice Springs airport. Possible small tornado associated with a
trough and large cumulus.
�-. Aviation Safety Digest
139
Aviation Safety Digest
139
I
Exams
bother?
why
by Graham Smith
EOPLE HAVE been flying aircraft for over
80 years and in previous times, pilots did
not have to pass all of t he examinations
that are currently required. An yway, why can't
all the theoretical bits be tested during the
flight test? Aren 't the exams just another way
of giving more public servants a job?
The bas ic function of any licens ing system is to
grant privileges to selected individuals. This of
course means that some people will be
app roved to have these privileges a nd oth ers
will be excluded. In fact it becomes illegal for
those to practice the particu la r activity. This
applies to tradesmen w here certain trained a nd
skilled people only are permitted to ins tall or
modify electrical wiring or plumbing. It applies
to vehicle driver s - and it applies to people
engaged in avi ation either as licensed maintenance engineers or pilots. A minimum standard
of training, knowledge a nd technical skill is a
prerequis ite for those people to have the privilege of holding a licence - and in all cases
some mean s of testing t hat knowledge and skill
is required so that the individual can be
assessed as fit or unfit to hold that licence.
In the case of aviation, we are authorising the
individual to exercise the privileges of the particula r licence in such a way that it is unlikely
t h at the safet y a nd well-being of t he rest of the
community is prejudiced and so that passengers
are safely and reliably conducted to their
destination.
Two points s hould be emphasised:
• The use of t he word, 'unlikely' is well considered. There is no absolute guara ntee that
any system will be perfect and it would be
unduly restrictive to make the tests so severe
that only a very select few can gain a licence.
The legal term is 'beyond reasonable doubt' I
believe.
• Specialist skills and qualifications are
required to pilot an aircraft safely. Persons
who do not possess those s kills and qualifications may not pilot aircraft. Additionally
not a ll persons who wish to pilot aircraft are
capable of achieving t he skills necessary to
ens ure that the rights of other members of the
public ar e protected.
The Australian Government has charged the
Civil Aviation Authority w ith the task of ensuring safe air navigation, and has specifically
empowered it to utilize licensing of aircraft
pilots as one means to achieve that objective.
Along with all other ICAO States t he Authority
has established control mechanisms governing
t he qualifications of pilots, a nd uses eigh t
measures to assess the suitability of p ersons to
pilot a ircraft • Cit izenship.
• Medical standards.
• Language qualifications.
•Age.
• Aeronautical knowledge.
• Aeronau.t ical experience.
• Aeronautical skill.
• Recent experience.
Testing methods
There are several different methods of testing a
candidate's suitability against each o.f the above
criteria. Arguments can be mounted for and
against t he methods used by t h e Authority. For
example the value of measuring blood pressure
in a doctors surgery instead of in the cockpit
during periods of high workload is questionable. It can be argued that vision standards
could be adequately tested during operations,
and hence the 'artificial' standards to be met
during the present remote testing can unfairly
r estrict an individual. The same can be said
about audio standards. T he r ationale for us ing
age as a measure of mental and physical
maturity is a ls o open to debate. And for how
much does aeronautical experience count? Why
isn 't demonstr ated ability alone enough? Flogging around familiar terr a in just to accumulate
command hours or to 'gain' navigational experien ce can be regarded as a r ather futile exercise.
However all ICAO States utilize the same criteria and s imilar techniques as Austra lia to
'ensu re' safe air n av igation. No St ate has been
able to derive any dramatically different
methods.
One r eason for using remote testing of p ilot
qua lifications is administrative efficiency.
Ther e is no doubt that a ll of the crite ria could
be measured adequately in the cockpit. But the
cost of doing so, for several thousand pilots
each year, would be prohibitive.
Standards
The determination of acceptable standards is
another aspect w hich all regulatory au thorities
find difficult. Should the hearing s tandard for a
pilot flying j et aircraft be the same as for one
flying a twin-piston? Should a ll pilots be able to
flight plan in 30 minutes? Shou ld PPL holders
be required to demonstrate proficiency under
the hood or be able to u se the VOR? There are
no clear cut ans wer s to these questions, and t he
problems a re exacerbated w hen remote testing
techniques are employed.
Testing knowledge
And so to testing aeronautical knowledge in
formal written examinations in an environment
remote from the aircraft.
Three groups of aeronautical knowledge are
widely r ecognized • Must know.
• Should know.
• Could know.
The difficulty of determining the elements in
each of the groups is increased by the rapid
ch anges in aviation technology. As in all fie lds
of scientific endeavor, aviation technology is
changing at an enormous rate. What seems to
be relevant to today's operational techniques is
irrelevant to tomorrow's. Perhaps a poor
·example but one which illustrates the point is
t he advent of the ADF. Mos t of us have never
used a radio compass which required t he loop
to be rotated manually. Nowadays, just switch
it on , identify the s tation and the needle point
to the station! Beauty! Automatic ! But did you
realize that there's a reason why it's called an
AUTOMATIC Direction Finder ? It wasn 't
always so easy. A ma nually rotated loop
r equired a differ ent knowledge standard higher in fact.
Assuming that we have established t he items of
knowledge required , we can s tart t hinking
about pass standards. Sure ly t he ' must knows'
have a pass standard of 100%. Anything less
must be unsafe. Right? Right! But are we confident t hat we can demand 100% in a remote (or
simulated) environment? And if not 100% then
what? And what about the poor candidate who
works right t hrough the problem until the last
line, but then makes an arithmetical mis take
and 'loads' far too little fuel for the overwater
flight?
Now what about the 'should knows'? Why are
they 'should knows' and not 'must know '? What
purpose do they serve? Opinions around t he
world differ markedly . Perhaps the most widely
accepted argument is that after a pilot has complied with the prescribed procedures, and hence
he s hould know because they ena ble him to
improve the efficiency of his operation. One
example might be the effect of wind on specific
ground r ange. Not important for many flights
but nevertheless it may have a bearing on others.
The 'could know' items are less well defined
again. Perhaps t hey give the pilot a sense of
comma nd of his operating en vironment, and
consequently impart some 'emotional security'.
The biggest danger in this a rea st ems from
pilots believing they know more than they do: a
little knowledge can be a dangerous thing.
Recency
The need for recent experience is readily
accepted in the area of aeronautical skill. The
argument is not so readily accepted for aeronautical knowledge. The Biennial Flight Review
calls up a review of aerona utical knowledge
and perhaps this is adequate. Knowledge
deteriorates w ith t ime and a bit of a brush up
now and again doesn 't do any harm. Some other
areas for which a recent demonstration of
knowledge s hould perh aps be demanded and
which a re not so obvious are progression to a
higher licence level, IFR pilots operating VFR
after a long break from VFR ops, and airline
pilots operating OCT A again after a long break
from that en v ironment. At t he present moment
there is no formal testing required for the later
two transitions. Regarding up-grading licences,
testing of all the knowledge applicable to the
lower level of licence would require a very long
exam.
CPL
No discussion of written examinations as a
method of testing aeronautical knowledge
would be complete without some mention of the
CPL (Aeroplanes) examination structure. The
Australian system is unique, but is not likely to
be for much longer. At least two countries are
interes ted in t he system. The provision for candidates to prove their proficiency in t h e elementary concepts (elementary does not mean 'easy',
but rather 'constit uent') before being confronted with the compound and complex task of
planning a commercial operation is proving a
boon to both candidates a nd the Authority. At
the time of going to press, t here had only been
one ex am series where the pass rate was less
t han 50%. This is in stark contrast to the situation of the previous system w here pass rates
of 25% were common. However the system is
still far from perfect. Until now the Final Exam
has only been available at three scheduled sittings per year, and it is something of a milestone t hat the availability was increased to 'on
demand' from October 1988 - would it be in
order to say that this is another Bicen tennial
Achievement? This will complete the transition
from a ll exams being availa ble only on a s cheduled basis to all exams being non-scheduled the change-over having been accomplished in
less than four years. The last step in the CPL
system w ill be to streamline the s ubjects and
exams a s discussed a bove. Hopefully t his will
result in a substantia l reduction in the number
of multi-choice exams.
The challenge of d etermining a ppropriate flight
crew standards, more accurately defining the
role of aeronautica l knowledge, and t he most
efficient method of testing that knowledge, will
forever be with us . Meanwhile t hink about
what you know and note wher e and when you
h ave been uncer tain what to do. Maybe the
uncertainty was due to a lack of know ledge 0
�Aviation Safety Digest
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Aviation Safety Digest
139
Sensitive and critical areas
ILS
Some
whats and whys
Life jackets
.mHE AIRCRAFT had just taken-off and was
cruising at 1000 feet over the water. At this
_ point the pilot noticed a change in the
engine note and turned back towards the strip.
The engine was now running roughly and the
power output reduced to zero. A ditching was
inevitable.
The landing on the water was successful and
the aircraft floated in a sixty degree, nose-down
attitude. Water began to enter the cabin
through the broken windscreen.
The four passengers escaped through the righthand door and the pilot through the left
window.
After clinging to the aircraft for a short time,
they all decided to swim for shore - a distance
of about t wo kilometres.
They were all s ubsequently picked up by a rescue boat.
The aircraft sank after about fifteen minutes .
None of the occupants were wearing the life
jackets that were provided and which were
required to be worn by the company's operations manual.
l
by Captain John Edwards, Airways Surveyor, Civil Aviation
Authority
The recent ditching near Outer Harbour in
South Australia ended in more tragic circumstances - one of the occupants swam for the
shore and was never found . Again no-one was
wearing life jackets even though this flight had
just crossed St Vincent's Gulf.
It seems stupid to say that the requirement to
wear life jackets was framed to protect the
pilot and passengers of the aircraft - not to
make them uncomfortable. It's not alw ays possible to fly at an altitude that keeps you within
gliding distance of dry land and the risk of having to ditch may be low - but it's hard to
explain to grieving relat ives t hat their kin
drowned, especially in some cases, while there
was a perfectly serviceable life jacket in the
baggage compartment D
T
HIS ARTICLE is not intended to describe
how to fly an ILS in a particular aircraft
_ with a certain instrument fit , but rather, to
identify w ith justification some of the features
of the operational environment th at are
required because of an ILS. The article w ill also
discuss some of the less well understood features of an ILS procedure. The n eed for the
article is that much of the relevant material is
not conveniently collated under one cover with
t he result that it is a constant source of reasonable questions - refer ences are provided at the
end of the article.
The operational environment
Medium-rare
and well-done
HE AIRCRAFT was being ferried to
' Waikerie for a major inspection. The
_ weather was not a problem and the aircraft
;.a;, cruising at 2500 feet.
The pilot had owned the aircraft for about six
months and had been operating from his own
property.
As he was cruising along he became aware of a
hot, oily smell. He turned off the heaters and
checked the engine gauges. Indications
appeared normal although the oil temperature
was on the high side of the green sector.
Then oil started streaming up the windscreen.
The pilot immediately closed the throttle,
declared an emergency and picked a paddock
for a forced landing.
~·-=JC
He turned the aircraft left and made a
straight-in approach. Although the engine was
turning normally he made a glide approach and
on final, turned the switches off and pulled the
mixture to idle/cut-off.
The aircraft touched-down normally and the
pilot braked as quickly as possible.
As the aircraft came to a stop the pilot noticed
smoke billowing from the engine area. As the
aircraft stopped rolling he grabbed the
extinguisher and exited by the rear door to
avoid the smoke that was now billowing from
the engine. He opened two fasteners on the
engine cowls and emptied the contents of the
extinguisher into the compartment.
It had no apparent effect and fearing that the
aircraft might explode, the pilot grabbed his
overnight bag and ran up the hill to the south.
As he passed the 100 metre mark, the engine
fell forward from the airframe and the tail
settled onto the ground. Within a further two
minutes, the cabin was ablaze.
The aircraft was destroyed by the fire.
The damage was so severe as to prevent any
reliable assesssment of the cause of the fire.
Fortunately this type of occurrence is mediumrare and this pilot's response was well-done D
The category of ILS operation h as a direct bearing on the requirements of the operational
environment provided, as does the geometry of
the installation relative to the movement area.
Therefore every installation w ill not necessarily
attract each feature discussed in the following
paragraphs.
Multipathing
Multipathing (1 ) occurs when an ILS localizer
or glidepath signal is reflected from a s urface
not associated with the ILS installation. The
res ult is an additional unplanned signal path
from t he transmitter to the airborne receiver. If
the receiver is una.b le to detect and discriminate
against the false path, the input to the pilots
indication will be corrupt. The likely indicat ion
will be a needle fluctuation, sometimes for a
number of seconds. In ba d cases , the ' OFF' flag
may activate momentarily. Such occurrences
may cause an autopilot to disengage.
During some phases of an ILS approach, such as
approaching the DA, or during a procedure's
autoland phase when the aircraft is below t he
category 1 DA, it is unacceptable to have the
ILS signal corrupted by avoidable events. At
other critical stages of an ILS, avoidable corruption is extremely undesirable as it can cause
pilots unnecessary concern about the
serviceability of the ILS to the extent that
approaches may be aborted.
In order to minimise multipathing from t rans ient sources, such as aircraft, vehicles et c , areas
around each transmitter ar e assessed and critical areas and sensitive areas are declared. The
critical ar ea is in the immediate vicinit y of the
antenna and must be kept free of transient
mult ipath sources during all ILS operations.
The sensitive area sur rounds the critical ar ea
and must be kept free of larger t ransient
mult ipat h sources during t he more critical
phases of ILS operations . The most likely
sources of infringement of theses areas are:
(a) Glidepath. Air craft taxiing for takeoff a nd
p ass ing in front of the antenna, and
(b) Localiser. Landing aircraft during roll-out
and while taxiing away from the immediat e
runway area, and aircraft overflying the
antenna during takeoff.
Operational procedures (SMC and vehicle control) are used to prevent unauthorised penetration of these areas. However, pilots need to
be able to ident ify the areas to prevent
unaut horised and inadvertant penetrat ions. The
internationally approved means of marking
critical and sensitive areas a re:
(a) Day. By marker boards or holding points
(2), (3), and
(b) Night. By having the t ax iing centreline
lighting within the area displayed as alte rnate green and yellow lights (4) and/ or
marker boards and holding point s (2) and (3).
We should recall the AIP RAC/ OPS-0-40 defines
condit ions which cause aircraft to be of concern
as sources of multipath interference in sensitive
areas.
Monitoring
Suscept ibility to multipat hing means that ILS is
a navigation aid that can be serviceable but
which may present to a pilot as being unreliable. This is one of the reasons that ATC is
required to h ave r eal t ime monitoring of the
ground inst allation. This enables a pilot who
experiences brief interference to the ILS and
w ho is unable to ident ify the likely source as an
aircraft movement, to q uickly check t h at the
ground equipment is indicating normal opera tion. ATC also need to know as early as possible of the failu re of an ILS component as a
likely outcome is an immediate requirement to
re-organise t r affic.
Holding points
The discussion on multipat hing expla ins why
ILS holding points might be established around
the roll-out end of an ILS runway and near the
approach end in the vicinity of the glidepath
antenna. However , ILS operat ions may also
require the establishment of h olding points
around the first 1200 m or so, of runway to
ensure that a ircraft on the ground do not present a n obst acle to air cr a ft that execute a
�Aviation Safety Digest
139
Aviation Safety Digest
139
missed approach from the DA (5). Holding
points establish ed for this reason are usually
further from the runway than many pilots may
expect as the norm and, in fact, a need may
arise to establish these points along parallel
taxiways. These holding points are nearly
always required where category 2 or 3 operations are authorised.
Localiser width
Many pilots will have found some localisers to
be more sensitive than they expect. The reason
is that contrary to widely h eld belief, localisers
are not installed so that they all have the same
angular displacement for a given sensitivity, ie
a dot on the pilots indicator does not represent
the same number of degrees on all localisers.
This is brought about by an operational consideration which is that the pilots chance of
landing off an ILS should not vary between
installations, ie, at the threshold the aircraft's
displacement from the centreline should be the
same on all runways for a given indication in
the cockpit. The advent of autoland made this
consideration a requirement. Therefore,
localisers are installed so that normally they all
have the same width at the threshold (6), Figure 1 refers. Consequently localisers on longer
runways will be narrower at the markers and
considerably narrower at the outer locator.
Assistance in overcoming loca liser intercept
problems is provided by lead radials and bearings and is described later.
The purpose of the marker beacon is:
(a) Outer marker, to enable the pilot to conduct
an altimeter/ glide slope validity check (11),
(b) Middle marker, to warn of the impending
arrival of minima (12), and
(c) Inner marker , to warn of the impending
arrival of the threshold (13).
The outer marker allows the pilot to compare
the 'on slope' altimeter reading with the precalculated trigonometric information calculated
by the procedure designer and provided on the
approach chart. Any difference will only have
its source in variation in the atmospheric conditions from those assumed by the procedure
designer (usually ISA), an a ltimeter malfunction
(misset QNH or mechanical failure) or a
glideslope failure that has not been detected by
the ILS monitors.
The role of the middle marker has changed
subtly with the acceptance of the aircraft category concept and the potential for various categories of ILS operation to be flown on the
same installation. The marker would .be positioned a long way from some minima points if
it were sited to satisfy the highest possible
minima. Therefore, in Australia the middle
marker is usu ally sited near the category 1
minima points (5) and, for the pilot, receipt of
the marker signal means that he should h ave
made or should be making the decision to continue the approach or to execute a missed
approach.
Procedure design
Marker beacons or DME
The normal ILS installation requires the provision of marker beacons (7). DME may be provided in lieu of markers (8) but only where the
provision of a normal system is impractical and
then only in accordance with strict frequency
pairing (9) and geometrical (10) requirements.
Markers are superior to DME in th at they provide the pilot with independent and preset
audio and visual reminders that he has reached
a point on the procedure where certain parameters must be confirmed or actions taken if
the safety of the procedure is to be assured. By
comparison, DME information is passive and,
therefore, must be actively sought by the pilot
to provide a similar service. Consequently, a
pilot who is distracted during an ILS/ DME
could easily miss a s ignificant safety
check-point.
Altimeters are calibrated to read correctly in
ISA conditions. When a pilot sets QNH, he
applies a correction for both the pressure and
temperature variation from ISA conditions at
the QNH datum. (The QNH datum is the place
where the meteorological readings are taken,
usually the aerodrome in Australia).
Unfortunately, the QNH corrections are only
correct at the datum. Consequently, as height
above the datum increases , so does the magnitude of these errors in the indicated altitude,
but with the origin of the error now the datum
rather than mean sea level, Figure 2 refers.
RATIO OF
LLZ WIDTHS
ALONG TRACK
distorting effects. However, pilots who assess
cold weather conditions as justifying corrections that increase the lowest holding altitude
and intermediate descent limits are free to do
so but not without notifying ATC of their
required altitudes as such changes could affect
separation with other traffic. Pilots operating
in some overseas areas would be well advised
to make these additional corrections as a matter
of course.
Therefore, during preparation for an ILS the
pilot should receive the ATIS, assess the temperature effect on the DA and determine the
value that he should use, and assess the effect
on the outer marker crossing a ltitude and determine the expected indicated altitude at the
marker.
Application to outer marker checks
/
QNH datum
/
To calculate altitud e correction lrom temperature
on a computer. use heigh t above lhe elevaUon of
the QNH datum.
- - -- TRUE ALTITUDE
- - INDICATED ALTITUDE
Figure 2
An ILS procedure is designed using nonprecision techniques up to the final approach
fix (FAF) or, if a fix is not specified, the final
approach point (FAP) and for the missed
approach usually after the procedure reaches a
height of 1000 feet. This means that even
though the pilot may acquire, and navigate by
reference to he glidepath before the FAF/FAP,
the safety of the aircraft is only assured if he
complies with the descent limits and fixes that
define these segments. Because the tolerances
associated with the glidepath exceed those
required by non-precision techniques at ranges
in excess of 3 nm from the threshold, a pilot
w ho chooses to fly the glidepath at the expense
of other descent limits may place his aircraft in
jeopardy. In other words precision techniques
are only used to ensure obstacle clearance for a
ver y small part of an ILS procedure.
LLZ WIDTH AT THRESHOLD
Temperature error correction (14)
The pilot does not have the means, or in most
cases the time, to determine the exact magnitude of altimeter error due to temperature variation from ISA. Even if he could, it would be
unwise to apply the value in a simple additive
fash ion as it is not the only factor assessed in
the procedure designers obstacle clearance
values and, these factors are not usually combined by a simple additive method. However,
temperature variation can achieve a disproportionate significance. Therefore, to ensure a
safe operation AIP-DAP page 2-11, para 2.9
requires the minima to be increased when temperatures are less than ISA. However, the same
section of DAP prohibits reduction of descent
limits in the same way for the reasons given
above.
AIP-DAP has no requirement to adjust descent
limits encountered before the DA or MDA or the
lowest holding altitude, rather, t he need for
such precaution is a judgement left to the pilot.
The reasons for this are that Australia does not
experience the extremely cold air masses common in Canada for example, and this means
that in Australia the most significant variation
from ISA will be near the surface and, consequently, near the DA/ MDA where obstacle
clearance protection is least tolerant of
The effect of temperature variation from ISA
on the indicated a ltitude shown during an outer
marker check s hould be understood. Because
the pilot is flying the glidepath, he needs to
apply the temperature correction to indicated
a ltitude in the opposite sense to that used when
determining minima and descent limits. Therefore, the pilot who is 'on slope' on a hot day
can expect a low indicated altitude at the outer
marker a nd the reverse for cold conditions. An
example of the magnitude of this effect combined with other factors is given in AIP-DAP
page 2-11 para 2.8.
Lead radials and bearings
Earlier discussion identified the potential for
narrow localisers. If a pilot who is intercepting
a narrow localiser waits for the localiser bar to
become active before initiating the turn on, he
may be unable to avoid overshooting the localiser. The same effect may occur if t h e localiser
intercept angle is too large. The procedure
designer can assist the pilot by providing a lead
radial or bearing. These lead radials/ bearings
are nominally 2 nm before the localiser course
and are points where the pilot may initiate the
turn so as to avoid overshooting the loca liser
during the intercept. The DAP legend shows
how lead radials/ bearings are depicted.
Missed approach initiation and height loss
The DA/ DH is the latest point at which the
pilot must initiate the missed approach (15) by
the most effective means (16) if the pilot has
decided against continuing to land. This means
that the decis ion to continue or not, is taken
before the arrival at the DA/DH. This strict
definition is necessary so that both pilot and
procedure designer have a common understanding which then a llows the designer to apply
height loss values to the DA/DH. These values
are to protect the aircraft during the initial
missed approach when the aircraft will sink
below the DA/DH. The values used are in the
table over (17) and were det ermined from
observation of normal operations.
�Aviation Safety Digest
139
A IRCRAFT
CA T EGORY
( Va t>
MARGIN USING
RADIO A LTIM ETER
MET RES
FEET
If you are not eligible for a free issue, or if you would like additional copies of the Digest: -
MARGIN USING
PRESSURE ALTIMETER
MET RF,S
FEET
A
169 km/ h ( 90 kl)
B
223 km/ h ( 120 kl)
c
260 km/ h ( 140 kl)
13
42
40
130
18
59
43
142
22
71
46
150
26
85
49
l(il
D
306 km/ h ( 165 kl)
The difference between the radio altimeter
values and the pressure altimeter values are the
inaccuracies associated with pressure altimeter.
Therefore , the radio altimeter values are essentially those associated with the aircraft. However, these values are intended to protect all
aircraft. Therefore, pilots wishing to assess the
legitimacy of their recovery technique s hould
use a third of the radio altimeter value in the
table above as the value achieved by 50 percent
of all s uch operations and two thirds of the
radio altimeter value as protecting 95 p ercent
of all ope rations. However, these values will
suffer a further slight reductions if read from a
pressure altimeter owing to altimete r lag.
CAO 40.2
CAO 40 .2 requi res t he pilot to be positioned at
t he minima s o that he may 'land w ithout undue
manoeuvering' . This requirement recognises:
(a) the concerns of CAR 257 and the need for
aircraft permitte d to the minima to have a
high assurance of completing a successful
landing,
·
(b) That pilots who proceed below the DA/ DH
into the visual segment of the procedure
and then execute a missed approach are
doing so from a point below and in front of
that assumed by the procedure design and,
this may significantly reduce the design
protection of the missed approach, and
(c) That the speed range at the minima differs
between aircraft types so that all types are
not equally sensitive to pos itioning at the
minima.
The requirement calls for a subjective v alue
judgement by examining officers but to do
otherwise would not recognise the different
capabilities of different aircraft types.
-
Readers should remember that determination of
DH by radio altimeter is not normally authorised for other than category 2 or 3 operations
because of the environment preparation and
controls necessary to ensure the necessary level
of confidence in the procedure.
CAR 257
CAR 257 prohibits a pilot continuing an
approach 'whe n any e lement constituting the
meteorological minima for landing is less than
that determined for that aerodrome except in
the case of an emergency' . This CAR prevents a
pilot proceeding to the minima to 'look and see'
if he can land. This seemingly conservative
restriction recognises that the missed approach
is not designed with protection that permits its
u se as a normal event (as distinct from the comparatively infrequent use it should get from
operations conducted in accordance with the
CAR). In the case of the precision segment of
an ILS the segment is designed with the follow ing safety objectives:
i
.•
~
Conclusion
This article dis cusses s ome of the less well
known features and less we ll understood facets
of ILS operations . The discussion is intended to
assist better pilot under standing. The
references provide a more comprehensive discussion of the items. The ILS is an excellent
navigation aid but like everything else in aviation it can be used a little more wisely and
confidently with an improved unders tanding D
Four
iSSU8S
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or over thirty years, the Aviation Safety
Digest has been an integral part of
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In July 1986, responsibility for the Digest was
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that the way forward is through increased
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Anyone with an interest in aviation wi ll benefit
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------------------------------------------~
References
(a) Overall risk of collision with obs tacles
1 x 10 - 1 c1s)
(b) Missed approach rate
1 x 10 2 (19)
1. AIP RAC/ OPS - 0 - 40
ICAO Annex 10, ParL 1, Att achment C para 2. 1.10
2. !CAO Annex 14 para 5.4. 2.3
3 . ICAO Annex 14 pa ra 5 .2. 9.2
4 . ICAO Annex 14 para 5 .3. 16.4
5. ICAO Annex 14 para 5.2.10.2
TCAO Doc 8169 - OPS/ Cill , Vol 2, Table 21-2
6. ICAO Annex 10, Part 1, para 3. 1.3.7.3
7. !CAO Annex 10, Part l , para 3.1. 2. l
8. !CAO Annex 10, Part 1, para 3.1.7.6.6
9. ICAO Annex 10, Parl 1, para 3.1.7.6.6.2
10. !CAO Annex 10 , Part 1, para 3.1.7.6.6. l
11 . ICAO Annex 10 , Part I, para3. l. 7.6.2.2
12. ICAO Annex 10, Part 1, pa ra 3. 1.7.6.2
The CAR recognises the above and is intended
to ens ure that pilots of a ircraft which are permitted to proceed to the minima enjoy a high
probability of being able to land off the
approach. (NOTE: International assessment has
been t hat the criteria necessary to protect the
missed a pproach ris k equal to the norma l event,
most likely would incur s ignifica nt operational
p enalty).
13. ICAO Annex 10, Pa rt 1, par a 3. 1.7 .6. l
14. AIP-DAP page 2-11 pa ra 2.9
ICAO Doc 8168-0PS/ 611 Voll , Table 3-4
15. AIP-DAP, 1-4
ICAO Doc 8168-0PS/611 , Vol 1, page 1-1
16. ICAO Doc 927 4-AN/ 904 pa ra 4.2. l
17. ICAO Doc 8168-0PS/ 6 11 Table 21-4
18. !CAO Doc 8 168-0PS/ 6 11 , Vol 2, para 21.l.4
19. !CAO Doc 8 168-0PS/ 611 , Vo! 2, pa ra 21.4.8 .8.3.2
!CAO Doc 9274-AN/ 904, Pa rt 2, para 7.3.1
-
SF
== - =
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
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'Immunity' applies with respect to any
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highlighted for the benefit of others.
Write to:
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Aviation Safety Digest
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CANBERRA A.C.T. 2601
Australia
Aviation Safety Digest 139 / i
�Aviation Safety Digest
139
AERONAUTICAL INFORMATION SERVICE AUSTRALIA
NOTICE
Some like it hot
CURRENT DOCUMENTATION & PLANNED NEXT ISSUE
Current Issue
Document
#
Planned Next Issue #
Bureau of Meteorology
DAP(E)
20.10.88
15.12.88
DAP(W)
17.11.88
12.01.89
AGA0-1-2
05.05.88
04.05.89
Aerodrome Diagrams
22.09.88
12.01.89
~ UMMER FLYING conditions vary greatly
- throughout Australia. This article provides
an overview of conditions in the tropics and
some other p arts of Australia; it does not
include all the local variations which are often
topograph ically induced.
The tropics
* ERS A
20.10.88
09.02.89'
A IP (book)
25.08.88
15.12.88
VFG (book)
25.08.88
15.12.88
A IP/MAP
30.06.88
15.12.88
VFG/MAP
30.06.88
15.12.88
DAH
30.06.88
15.12.88
II
dates quoted are effective dates
*
New document replaces AGA 3 & AIP/E RS
NOTE: C LASS 1 & CLASS 11 NOTAM ARE TO BE CONSULTED
WH EN USIN G ANY OF THE ABOVE DOCUMENTS.
ISSUE: 4
DATE: 01 N OV 88
viii / Aviation Safety Digest 139
The 'wet ' season in the tropics encompasses all
the summer months and a variable period at
either end . The 'wet' is characterised for most
of the time by weak pressure gradients and hot,
humid unstable weather conditions. Thunderstorms are almost an everyday occurr ence at
some locations with a diurnal peak in the late
afternoon and evening. The frequency is
greatest over the northwest Kimberley, the 'top
end' of the Northern Territory, and inland
Queensland between Normanton and
Charleville .
Tropical storms are much larger in vertical
extent t han those experienced in temperate latitudes and often spread out to form sheets of
altostratus an d cir rostratus clouds towards the
end of t heir life cycle, r esulting in steady overnight rain an d low cloud persisting in the morning . Th ey also grow rapidly and the transition
from benign to dangerous flying conditions can
be dramatic.
The onset of the n or thwest monsoon in earnest
sees a change from the thunderstorm patter n to
one ch ar acterised mor e by heavy stratiform
rain. This is pa rticularly so in the vicinity of
t he monsoon trough where the northwest winds
from t he equator meet the easterlies which predominate over cont inental Australia dur ing
summer mont h s. Low stratus is a real hazard in
this sit uation due to persistent heavy precipitation and over cast middle level cloud, and may
persist around the exposed coasts and ranges
for days on end. However, the mere presence of
t he mo nsoon t rough does not guarantee this
type of weather . The monsoon has active and
quiet periods and t he associated weather patterns can range bet ween t he two scenarios
described here - t h e point is that a lmost every
d ay during t h e wet season will produce weather
condit ions which a re difficult, if not dangerous,
for the unwary pilot. Careful scrutiny of t he
forecasts and, w her e possible, elaborative briefing are of paramount importance.
Southern Australia
Summer, w ith its long periods of clear skies
over much of southern Australia, often presents
the best flying conditions there. However the
pilot must be conscious of:
• The moderate to severe thermal activity in the
lower atmospheric levels that accompanies the
high temperatures.
• The occasional thunderstorms that are usually
high based, but nevertheless can cause sev ere
downdrafts, heavy showers and hail.
• The reduced visibility that occurs when dust
is raised from the dry surface.
• The high dens ity altitude at elevated locations
and its implicat ions.
• Local topographic effects which a re often
magnified in summer.
• The relatively high incidence of low cloud and
reduced visibility usually associated with
shower s and drizzle along the NSW and East
Gippsland coasts and windward s ide of t he
ranges when an onshore stream prevails 0
�Aviation Safety Digest
139
Aviation Safety Digest
139
Benchmark
safety
Setting some personal 'benchmarks' in our flying could go
some way towards improving our sa fety record.
by Julian Johnson
AFETY AND good airmanship are synonymous. But we all break Lhe rules or do
something stupid occasionally.
I've just been looking at general aviation aircraft accident numbers for 1986 and 1987. They
make interesting reading only if you have a
morbid fascination for statistical data. In bare
bones terms, they tell us that there were 218
general aviation accidents in 1986 and 215 in
1987.
The experts s ay that, for general aviation at
least, accident numbers have ' ... stabilized at a
mean of 235 per ann um, regardless of the number of hours flown '. In plain language that
really means that our accident record has ' bottomed out' and , given essent ially similar conditions, is not like ly to vary much in the
foreseeable future. Lest you should start feeling
comfortable about that though, its worth knowing that some 8% of our accidents are fatal and
res ult in the death of about fifty people every
year. There's no room to be comfortable about
that level of tragedy.
As well as being tragic, the individual accidents
that make up our statistical record make good
headline news. Technically uninformed though
it may be, bad press is a powerful weapon in
convincing the general public that fl ying light
aircraft is a dangerous occupation , and such
public view can, and often is, used as the justification for the imposition of more r egulat ion
and controlled airs pace by our opinion conscious political masters.
Statistics also mean money. A Rureau of Air
Safety Investigation sLudy estimates thaL, in
1980 terms, the minimum annual cost of a ircraf t accidents to Lhe community is $3 1 million .
The cost of nearly everything we pay for when
we go fl ying, from fuel, to insurance, to t h e
actual price of the a ircrafL is, at least in p art, a
reflection of ou r safety record.
Reading the details of the individual accidents
making up our safety record, iLs hard not Lo
reach the conclusion t hat Lhere are some pretLy
crazy people around. Perhaps, with t he all
powe rful benefit of hindsight we may laugh a
little, smugly confident that we would never
personally get ourselves into s uch a situ ation.
But in truth there's probably few of us who
could not say ' ... there but for the grace of God
go I'. In truth, every one of us can probably
recall a time in our per sonal flying w hen we
have broken t he rules or displayed abominable
airmanship.
One school of tho ught has it that on ly by flying
close to the edge is it possible to build Lhe
expe rie nce necessary to become a fully compeLent pilot. AnoLher that a viation, whilst not
in itself inherently dangerous, is s imply more
unforgiving of error than many other forms of
activity. Whichever way you look at it though,
it would appear th at most malfunctions occur in
Lhe front left seat and that they could in many
instances have been easily avoided by better
decision making. Human nature seems to promote a view that perseverance will be rewarded
with s urvival.
Think of it in terms of driving you r car. There
are a good few t imes when we ar e faced with
the decision to s top as a t raffic light t urns
amber at an intersection, or press on, trusting
to speed and bravado to get us through before
it turns red . A nervous glance in the rear view
mirror, a silent ' phew!' and we are on our way.
Was it a good decision? We ll - in hindsight
perhaps not, but we survived didn't we?
And the same is true in flying, at least to the
extent that we are required to make many
decisions - some of which will be wrong.
Wrong because it is an undeniable human trait
that, by definition , some decisions will be
wrong decis ions. The more t raine d, the more
experienced we are, so w ill the proportion of
' right' decisions we make increase . But you can
bet your life you'll never get one hundred percent.
That's not to be de featist about it; just realistic
about the fact that we are all human. Perh ap s
that's why the experts say that our safety
record has bottomed out. There is surely a recognition there that wrong decisions are going t o
continue to be made .
One possible conclusion to reach is that we may
be able to enhance our decis ion making ability
if we each set ourselves some personal benchmarks in our flying - benchmarks which we
have a commitment to adhe re to when making
decis ions about our flying.
I've thought of a small example set of personal
benchmarks w hich we might try applying to
ourselves. They a re just an example of what is
possible - perhaps to get you started on a set
more appropriate t o your own particular needs.
Working them out is not necessarily an easy
task because there is always a tendency to try
to be too comprehensive and in doing so defeat
the purpose of t he whole exercise. You see, for
any set of benchmarks to be consisLenLly
applied they must be fundamentally simple.
Otherwise we may fail to remember the m or to
make accurate decisions about them when we
have reached t hem.
Anyway, he re is an example set which you may
like to consider. Keeping s implicity in mind, it
is based on the mnemonic 'SAFETY' where 'S'
stands for Signs, 'A' for altit ude, 'F' for Fuel,
'E' for Evaluate, 'T' for Turning, and 'Y' for Yield.
Here's an explanation:
Signs - read the signs. If something doesn't
feel or seem right, make a conscious decision to
stop what you're doing and look at the signs.
What are t he clouds and cl'oud shadows doing?
Wher e's the wind from and at what speed? Are
there horses in the trees next t o that short runway or signs of heavy rain the nighL before?
What does the engine n ote tell you? The bulk of
potentially h azardous situations in f'lying tend
to pre-announce themselves. If you can read
and react t o the signs before things get out of
hand: your chances of making more right
decisions have to improve. Even if t h ey're not
pre-annou nced , most problems will be better
solved if you remember to consciously stop
what you 're doing and read the signs.
Altitude - Set a minimum safe altitude for
every flight of 1500 feet above terr ains 10
miles either side of your track. There 's space on
the Flight Plan Form. If good VFR isn't possible
at that altitude, look to turning back. T h is
benchmark will keep you 1000 feet above terrain and 500 feet below the cloud base at all times.
Don't fly on top of even scatter ed clouds except
where they're localised a nd well defined. Cloud
shadows will help you make the righ t decision .
Fuel - a lways ensure a reser ve of 60 minutes
in your t anks on the runway at the end of your
flight. If you can see during the flight t h at
yo u're going to be short, look to alternat ive
actions.
Evaluate - constantly before; during the progress of; and after your flight . What went
wrong and what went right? How can I
improve? Through constant evaluation, always
know your position, your fuel state, wind direction, and the closest suitable landing area.
Turning - never sharp turns (more than 30
degrees of bank) below 500 feet . If you're
below 500 feet chances are you 'II be in a
takeoff or landing configuration. EiLher way,
airspeed will be criLical and you '11 have no time
to recover if something goes wrong.
Yield - to the s ingle minded determination t o
press on when the signs indicate that you are
about to exceed one or more of your
benchmarks.
Sound simple enough? Well, all this is not to
say that the simple expediency of apply ing a
set of personal benchmarks to our flying will
improve our safel y record overnight.
What they w ill do though is to provide you
with a self im posed limit or reference point a 'fence ' if you like wh ich w ill automatically
ring alarm bells as you approach it. Because the
time will s urely come when you will ignore the
limit. The point is that if your limits are set
and are simple enough to easily remember, you
will imme diately know when you break them.
This knowledge, in itself , can be very useful to
you. You will know that you are entering into a
possibly hazardous situaLion and steel yourself
to a range of alternative actions. This is where
the old adage of 'prior preparation preven ts
poor performance' comes inLo its own.
Forewarned in t he knowledge thaL you are
breaking you r own self imposed limits, Lher e is
a greater likelihood that you will be better prepared for the consequences.
So setting personal benchmarks on your own
flying could, at the ver y least, stop you from
getting into mos L poten t ially dangerous situations . But, in the event that it doesn't, t h ere's
at least a better than even chance that you'll be
more adequately prepared for the consequences
than would otherwise have been Lhe case.
Perhaps the setting of these kinds of person al
limits on your flying may appear a bit
'wimpish' to you. After a ll, one of the biggest
ad vant ages of priva te flying is the flexibility in
personal trans portat ion Lerms tha L it offers . To
remain a useful tool it must also remain un restricted by the imposition of arbitrary limits.
But the line between what is p r actical and what
is foolhardy must be drawn somewhere. That's
why we have rules . Remember that red t raffic
light?
So give it a try. Use the suggested mnemonic as
you write out your flight plan; as you' re climbing to you r cruise altit ude; as an in-flight check
list during any periods of inact iv ity; or w hen
your sixth sense tells you all is not as it should be.
Per haps setting some per sonal benchmarks in
our fly ing could go some way towards improving our safety record 0
�Aviation Safety Digest
139
Aviation Safety Digest
139
Ice and water
don't mix
by Roger F Tracey, Manager, Flight Operations, United
Technologies International
HE COMPLICATED and varied interactions
that determine t he effects of w a ter inges tion on turbine engine operation preclude
deta iled qu antitative engine module by module
analysis. The magnitude of t he s hifts in gas
gener ato r performance will var y depending
upon the par t icular cir cumstances. Howev er ,
the overa ll qualit a tive ch anges in engine oper ation resulting from t he ingestion of water
t hrough th e engine are listed below for a const ant t hrot tle pos ition.
N l & N2
May or may not be affected Depends on engine control mode
a nd amount of water ingest ed
Decreases
EGT
Incr eases
Fuel Flow
Increased possibilit y
Surge
Increased poss ibility
Flameout
Ingestion of w ater in liquid or s olid form will
affect engine operat ion because of the higher
specific h eat of water and t he latent he at of
vaporization associated w ith evaporation. When
flying through heavy rain storms, the compressors of a dua l compressor engine a re
' rematched ' b y th e water ingested. The reason
for t his is that when the water is v aporized
within the engine, it abs orbs a bout 1000 BTU
per pound of water from the air passing
t hrough the engine, e ffectively reducing the air
temperature in the downstream sta ges of t he
compressor and in the combust ion cha mber. The
ingestion of ice further incr eases the cooling in
the compressors as it absorbs heat while melting into water and t hen more heat as it ev aporates. The degr ee of rematch is, of course,
proportion al to the w ater/ air r atio and t he compressor design . The compressor rematch moves
the high pr essure compressor operating line
t oward the su r ge line , as illust rated in Figure 1,
t hus causing t h e compr essor to be more suscept ible to surge.
In addition, the compress or an d engine response
may be affected by the w ater as the aerod ynamics , tip clearance and sensed cont rol parameters become modified. If sufficient w ater is
ingested , compressor sur ge or engine flameout
may occur.
The engine inlet size basically determines t he
capt ure a rea for w ater ingestion. However, the
amount of air ingested depends upon air craft
a nd engine speed . At high a ircraft speeds and
low engine RPM more air is being forced into
t he inlet than t he engine r equires. Thus air is
spilled out of the inlet w hich effectively
r educes the size of t h e colu mn of air being
ingested. The water d roplets, being heavy, are
not ej ected and the result is an increased water/
air rat io. On a typ ical high bypass ratio engine,
this 'scoop factor' during idle descent increases
th e water/ air rat io by as much as 200 percent.
Incr easing en gine RPM incr eases the air flow
r equirement while maintaining the same area
for water ingestion. Reducing aircraft speed
w ill also reduce air spillage around the inlet.
This combination significantly reduc:es the
water/ air ratio as illust rated in Figur e 2.
HIGH PRESSURE COMPRESSOR
C ompression
ratio
JW11 !
llOllll •I
Airflow
SCOOP FA CTOR
lnlel air s pillage al low engine 1pm/ hig h aircr.·tlt s p@ed im; re;ises engine lace
Wll le r/ airratio
High e ngine rpm/low aircrall s peed d ec reases en g ine f<'ICI' w<>ler/ a ir ralio b~
redu cin g air splllage
w,
_,.,,/"
Figure 2
T YPICAL ENGINE CONTROL CHARACTERISTICS
Steady slate
dry operating line
fuel/air
ratio
-
Deceleration
schedule
Figure 3
N•
N2 decay due to waler ingestion a t constant throttle P?Sition
The effect of water ingestion on the engine
res ponse varies depending on the type of fuel
control installed on the engine. Earlier model
engines such as the JT8D and J T9D use a cont r ol w it h a droop governing mode, whereas
more r ecent engines such as the PW2000 and
PW4000 featu re an isochronous governing cont rol. The engine response characteristics pertinent to each fu el control are discussed
separately below.
Figure 3 illustrates the effect of water ingest on
on the fuel control sched ules for engines which
use droop governing controls . The da shed lines
represent fuel requ ired (operating) lines for
va rious rates of water ingestion. As t he water/
air ratio is increased the operat ing line moves
upwards tow ar d the acceleration schedule . The
highe r th e operating line t h e more fuel is
required to run s teady -state . It is apparent
from t he slope of the lines of constant t hrottle
pos ition on t he diagram that a rise in the operating line result s in a loss in N2 s peed w hen
t h rottle posit ion r emains fixed. The acceleration
schedule represent s the maximum fu el/ air ratio
av ailable to t he engine . As the operating line
rises it can , under t he most severe s it uat ion ,
reach the acceleration sch edu le, at which point
t he fuel control w ould be unable to deliver
addit ional fuel to accommodate t he increasing
water ingest ion. Under this condition, t he
engin e would sp ool down to the point where the
maximum fuel flow available was su fficient to
operate th e engine steady state. This would
event ually result in s pool down below idle, loss
of the t hrottle response and loss of a ircraft
elect rical power if t he generator drops off t he
line . As t he air craft leaves the ar ea of heavy
precipit ation , t h e water/ air r atio would
decrease and the fuel requ ired line would
low er, a llowing t he engine to re-accelerate to
t he origin al s et s peed providing surge or
flameout has not occurred as a result of t he
water ingest ion.
For engine cont r ols which use isochronous
governing, the engine r esp ons e will be similar
except that t he rotor s peeds will not ch ange at
constant th rottle pos it ion as water ingestion is
increased until the limitin g acceleration fuel
schedule is rea ched. At t hat point t h e engine
would rapidly spool down .
The engine response to t hrottle mov ement
var ies dep ending on t he d ir ection the th rott le is
moved.
Throttle Advance
As the fuel con t rol operating lin e rises due to
t he increasing wate r ingestion, the mar gin
bet ween the oper at ing line a nd t he acceleration
s chedule is reduced. Th e engine w ill respond
s lu ggishly to a n accele ration command from the
throttle because of t h e r ed uced 'overfueling'
ca pability of the control.
Throttle Retard
As the operating line rises, the margin between
the operat ing line and the decelerat ion schedule
is increased and the engine response to a
throttle position decrease is more rapid than
normal. Th is could result in a sub-idle condition
and possible engine flameout .
In summary, the ingestion of water by a tu r bine
engine result s in the following:
l. Reduced surge mar gin.
2. Possible engine spooldown to sub-idle.
3. Possible engine flameout.
4. Sluggish r esponse to throt tle advance a nd
rapid response to throttle retard .
Sever e storms s hould be avoided. Typically the
highest water concentrat ion exists bet w een
15 OOO and 20 OOO feet a ltitude . If flight must
be made in extreme p recipitation , the following
techniques are recommended:
1. Tu rn on ignit ion system to protect against
engine flameout .
2. Turn autothrot tles off to avoid rap id throttle
movements and pr otect against engine
spooldown.
3. Red uce ai rcraft speed and increase en gine
rpm to r educe water/ air ratio, increase
engine energy to deal wit h water evapor ation
and protect against spooldown. This condition is most prevalent when at low thr ust
d uring descent and holding operation.
4 . Avoid rapid throttle movements to r educe
possibility of engine surge. If t h rust changes
are necessary move throttles very slowly and
do not change t hrottle direction u ntil the
engine has stabilized .
These procedures a re most effective if init iat ed
p rior to ex t r eme pr ecipitat ion.
An Aeros p ace Industr ies Association (AIA)
committee consisting of r epresentatives from
engine and aircraft manufactur ers ar e stud ying
the effects of water ingestion on turbine engine
operat ion. This a rticle contains information
ava ilable at this t ime. The results of the study
and model s pecific recommendations w ill be
forw arded as they become k nown.
This has been coordinated with t he Boeing Aircr aft Company , Douglas Aircraft Compan y a nd
Air bus Industrie 0
�Aviation Safety Digest
139
Aviation Safety Digest
139
Mea culpa sobering
confession
a
6 HOLD a private licence with a command
g instrument rating and twin endorsement. I
have about 500 hours in total of which 300
hours are Twin Comanche time and I am the
proud owner of a Piper Twin Comanche PA30
Aircraft which is kept in good order and condition and w hich I fly regularly. The aircraft is
equipped with DME, 2 VORs, 2 ADFs as well as
HF Radio. I've held my private licence since
1982 and have passed two renewals of my
instrument rating.
I planned a flight in the Twin Comanche from
Coffs Harbour to Echuca to join in with the
International Comanche Society Australian
Tribe's 'fly in'. The flight was planned IFR,
departing Coffs Harbour at approximately 0330
GMT, refueling Bankstown and continuing to
Echuca, expecting to arrive after last light .
The weather for the trip was forecast to be
reasonable with the possibility of thunderstorms to t he west of Echuca at about my ETA.
Having regard to the forecast and t he fact that
ETA would be after last light, I planned to
refuel at Bankstown and thus have a maximum
endurance of 280 minutes for the estimated 139
minute flight from Bankstow n to Echuca.
My company on the flight was a friend who
holds a Restricted Pilot's Licence and is currently training for a n Unrestricted Licence .
The departure from Coffs Harbour was made as
planned and the flight to Bankstown uneventful
apart from some minor weather. Full refueling
was carried out at Bankstown and departure
timed at 0612 GMT. The p lanned time interval
to Echuca ex Bankstown was 139 minutes. The
endurance was 280 minutes leaving a planned
margin of 45 minutes after allowance for fixed
reserve of 45 minutes, IFR reserves of 20 minutes allowance (being 15% fuel for the flight
time of 139 minutes) and provision of an
a ltern ate.
The flight proceeded smoothly and the weather
near perfect.
=
The final leg from Corowa to Echuca was a distance of about 78 miles and would be flown
VFR procedures as there was no aid at Echuca.
The flight plan was to track outbound from the
NDB at Corowa with a cross check at
Numurkah, a town approximately 46 nautical
miles on the direct track to Echuca. We arrived
overhead Corowa at 0800 confirmed by the two
ADF's (tuned to the Corowa NDB) falling away
as anticipated. The outbound track was commenced on the 230 radial from Corowa with a
heading of 235 degrees, a 5 degree drift allowance being made. The VOR and DME were both
switched off as it was considered they would be
of no further use. The No. 2 ADF was tuned to
the off-track Shepparton NDB to enable directional orientation.
Darkness fell at Cor owa and an estimate overh ead Numurkah was made for the planned 0828
and care was given to track outbound from the
Corowa NDB on the planned track. Approaching
0820 a lit town was sighted over the nose of
t he aircraft and at 0827 both pilots identified
to their satisfaction that town as Numurkah.
The No. 2 ADF was reviewed and showed a
station at 330 relative. The WAC chart was also
reviewed and t he major road noted running
t hrough the town identified as the Valley Highway running north-south as well as a minor
road running away from Numurkah to the west,
t he roads being clearly visible. At this point,
being happy with the navigation, the flight continued a nd a ground speed check was undertaken that showed an average ground speed
since Corowa of 146 knots which is within
expectations for the aircraft.
At about 0840 the lights of a large town
appeared over the nose of the aircraft and we
considered that Echuca was in sight. Our ET A
for Echuca was 0840 and t he ETA was accordingly amended to 084 7 and Flight Service
advised.
Communication at this stage was commenced
with an inbound aircraft to Echuca. Communication was poor and the first inklings of trouble
with navigation became apparent as we were
unable to sight either the inbound aircraft or
the Echuca runway lights. It quickly became
obvious that the town w hich we had identified
as Echuca was not ou r intended destination.
Flight Service was immediately advised of the
difficulty and were most helpfu l and supportive
in our predicament. Flight Service immediately
sought my endurance, POB, our last reported
position, heading since then and T AS, of which
were provided as promptly as workload would
permit .
They s uggested the PAL for Shepparton be activated. Unfortunately this proved ineffective
and a command decision was made to return to
Shepparton. The NDB for Shepparton was
tuned in on both ADF's and t h e aircr aft took up
a heading of 060 with both ADF's on the nose
and Flight Service was advised of our intention.
At this stage, severe directional disorientation
was experienced and while no difficulty
occurred in the mechanics of flying the aircraft
the directional disorientation was most disconcerting. I had no knowledge as to how far
Shepparton was from my known position and
this created s ignificant stress and pilot
workload.
Flight Service then, and without any pressure,
r equested that I tune up the Mangalore navigation aids, advising the DME number which I
tuned and was successful in receiving. The VOR
frequency was next but wouldn't tune up. In
trouble s hooting this problem I remembered
that I had turned off the VOR! The VOR was
immediately turned on and activated. Thereafter the OBS was t urned until the flag read
'To' and the CDI centered. The track to
Mangalore was read off the instrument and the
aircraft's heading was brought around to track
to that station.
Flight Service h ad arranged for the lighting at
Mangalore be switched on and the rotating beacon activated . What a welcome sight! We were
given the forecast for Mangalore NOTAMs were
advised and an offer to activate the crossrunway lights if we preferred that direction. In
the circuit area as we entered the landing pattern Flight Service's advice to 'check wheels'
was welcomed and appreciated! We landed
safely at Mangalore and SAR was canceled on HF.
Needless to say, we were grateful to be on the
ground and somewhat disconcerted that despite
careful planning for the Corowa - Echuca leg
we had been unsuccessful in reaching our
planned destin ation.
It didn't take long when reviewing the charts
and flight plan to find that the correct track
from Corowa to Echuca was indeed 250 and
that for some reason this had been transposed
on t he flight plan to 230. A careless error
which could have had serious consequences.
Normally when preparing a plan for such a
VFR leg I take the track direct off the IFR
en-route chart with the use of a protractor and
I am unable to explain how the error in the
track occurred in the preparation of this flight
plan.
The cross checks that I had instituted also
failed to indicate early enough the impending
difficulties and only goes to illustrate how one
small careless error can lead to an accumulation
of problems.
In hindsight there are many lessons to be learnt
and I list some of these for your consideration:
l. Endurance - it is true that endurance is one
of t he more important aspects of flying particularly under IFR, when the destinat ion
does not have an appropriate aid, ETA is
after dark and the weather forecast is
marginal.
Whilst the pressure placed upon me due to
my error was considerable it was not half as
considerable as it may have been if either
fuel was a minimum or the weather had been
bad.
2. Normal careful flight practices tend to fall
away when pressure is applied and it is
important to realise that those long established practices and training which we all
undergo as pilots must be put into effect
when difficulty is encountered.
Stress creates a lessening of flying ability
and a conscious effort had to be made by me
to overcome rising panic, to put in place
those good flying practices in which I had
been trained and get down to the task of
resolving the difficulty in which I found myself.
3. It is hard to imagine the directional disorientation that one can suffer in the situation
described, even when Instrument Rated, as
the brain refuses to accept the obv ious that
you are not at the location at which you
should be.
4. It is also difficult to depart to another
location of safety when the location of the
departure point is unknown, and ther efore
the distance to the 'safety point' is unknown.
This only served to create further stress.
5. I managed to overcome these problems
reasonably successfully, setting up the aircraft for maximum endurance, ensuring that
it was flown carefully at an appropriate altitude and endeavoring to resolve logically the
dilemma by tuning in the appropriate heading and tracking to the a ids.
6. Hindsight states the obvious that better use
could have been made of the off-track aids at
Shepparton and Mangalore. I had at my disposal aids which included NDB, VOR, DME
which if used appropriately could have prevented significant stress , anxiety, and
embarrassment!
7. Flight Service - The value of assistance and
support from the Melbourne Flight Service
Unit was inestimatable. Their prompt and
professional assistance was a most valuable
weapon against the rising panic accompanying our navigational un certainty.
This incident serves to show how one small act
of carelessness can lead to a chain of events
which may have an unhappy conclusion. That
chain of events however can be broken if the
disciplines learned during the hours of training
are skillfully applied, all appropriate resources
available are utilised, adequate fuel is available
and the pilot is able to draw from his training
and currency in piloting techniques.
Any fool can make a mistake but successful
recovery requires more than being an ordinary
fool! D
�Aviation Safety Digest
139
Aviation Safety Digest
139
FOR YOUNG
PLAYERS
Trap 1
Trap 2
During a flying training sortie the instructor
simulated an engine failure by moving the mixture control to the idle/ cut-off position. The
student closed the throttle and pulled the carby
heat on. The instructor then moved the mixture
control to rich.
During the pull up at the end of a clean-up run,
a small note pad fell to the floor of the cockpit.
The pilot leant forward to retrieve it but almost
immediately the aircraft struck the ground.
During the s ubsequent descent the throttle was
opened twice. Each time the rpm w as brought
up almost to the green arc for about three seconds.
Because they were in a low flying area the
instructor allowed the descent to continue to
about 100 feet agl where he requested a
go-around.
The student moved the carby heat to cold and
applied full throttle. The engine responded
normally .
When the aircraft was climbing through 200
feet agl the instructor simulated an engine failure after takeoff by again bringing the mixture
control to idle/cut-off.
The instructor 's main concern was to see that
the student quickly lowered the nose to maintain flying speed. When the nose was lowered
he reselected the mixture to rich . The throttle
was still fully open.
There was no response from the engine. The
instructor took control and manipulated the
throttle without success. The aircraft was
landed in swampy scrub with considerable damage. The occupants were unhurt.
The dry bulb temperature at the t ime was 20
degrees and the dew point 17.
The note pad was used to record spraying
deta ils that were not critical to the operation of
the aircraft.
Trap 3
The aircraft was engaged on a multi-sector
flight for the purpose of transporting bank
documents. The pilot completed t he pre-landing
checks and made a normal tou chdown on runw ay 05 .
During the landing roll the under car riage began
to retract and the left main and nose gear
s ubsequently collapsed.
It was believed t hat t he pilot inadvertently
selected the gear up in stead of t he fl aps.
Trap 4
The departure from the ALA at Shute Harbour
had been delayed and the pilot was running late
for arrival at Hayman Island - an arrival that
was to be filmed by a TV cr ew that w as
already in position.
During the short flight the pilot noticed that
the airspeed was s lightly lower than normal but
he attributed t his to the possibility of water in
the pitot system - a problem that he had
encountered the previous day in another aircraft and that he had discussed with other
pilots t h at night. He tried pitot heat to correct
the problem without success.
The aircraft was to land on the w ater. The pilot
noticed on short final that the flap w as not in
the landing p osition - w hich he then s elected.
On touchdown, the pilot realised t hat the
wheels were still extended.
He tried to prevent the floats digging-in but the
left wing struck the water befor e the a ircraft
came to rest.
Sea survival
by M J Sonneveld (John)
..-- HE FOLLOWING is a brief story concerning
survival in the sea.
~ After last light on 22 January, 1979, I was
informed of a missing yachtman in Westernport
Bay , Victor ia. At the time I was employed to fly
a Surf Rescue Helicopter. The information I was
given was that t he man had been sailing a very
small (Pram) yacht and had not returned to
Phillip Island as expected .
As is common in r eports of a person missing in
Westernport or Port Phillip Bay, the seriousness of t he situation is not obvious until quite
late in the day after all other reasons for the
persons absence have been exhausted by family
and or friends .
The formal search was not commenced until
about 30 minutes before last light. All inexpensive means of searching were availed of first ;
the helicopter was not called out: nor could it
have achieved a great deal at night. Rescue
Helicopters were not quite as sophisticated in
those days. The night was quite warm and t he
seas were calm. However, t he sea currents in
Wes ternport reach about six knots and the man
could have dri fted a long way in a relatively
short t ime.
The man was not found that night. By next
morning the authorities were concerned enough
to pay for more expensive r esources. So the rescue helicopter was called out at first light. The
swamped , missing yacht was found by the helicopter crew about 90 minutes later . Some hundreds of metres from the swamped yacht we
sa w the very pale , exposed head of a man s till
wea ring his yellow life vest; he was dead from
hypot hermia. He had been in the water for
about 13 hours.
With this story in mind , how on earth w ill
people survive who have been fo rced to ditch
their aircraft in an expanse of sea su ch as Bass
Strait? I believe that most of the responsibility
falls on the pilots to ensure that they and their
passengers have a chance.
Assume you are island hopping across Bass
Strait in a single engine Cessna with two pass engers. Midway between the Kent Group and
Flinders Island you have an engine failure. You
manage to get out a Mayday; you prevent the
aircraft from breaking when it contacts ' the
water by ' holding off' close to the water as long
as possible. Were you wise in requiring all on
board to wear their life vests or did you leave
the life vests in their valises to avoid soiling
them? Lets say you were lucky and all on board
managed to be wearing their life vests before
the Cessna sank. (You might be very lucky to
have the aircraft afloat for three minutes.) Now
the three of you are in the sea. Where is your
survival beacon. Oh! It was mounted in the aft
fuselage; it has disappeared with the aircraft.
Sure a search will be mounted as soon as possible but finding you will be about as difficult as
finding three needles in a hay-stack. You are as
good as dead .
Assume you were wiser. On the same flight you
all wore your life vests and you managed to
borrow a four man life raft. You all got into the
raft and thou gh cold and wet none of you was
injured. However, the survival beacon sank
with the aircraft. Have you any comprehension
how difficult it is to see a small life raft bobbing in the white caps in a large expanse of sea.
You may be lost for days or perhaps it is sunny
and you knew how to use the helicopter to
flash one of the search a ircraft. Later you are
rescued by a h elicopter. You will most certainly
be sea sick and quite possibly suffering from a
degree of hypothermia. You are ver y thankful
for the rescue but are you wiser?
Assume you are well prepared for the above
ditching. You a re all wearing your life vests.
The life raft is la rge enough and readily accessible in the aircraft. You are also equipped with
as survival beacon designed to operate in the
sea. You h ad briefed the passengers properly on
what to do in the event of ditching and they
remembered the inst ructions. You find yourself
in your life vests , in the raft with the beacon
on. Ninety minutes later a large helicopter is
w inching you out of the sea. This helicopter is
equipped with a very efficient Automa tic Direction Finder which enables the helicopter to
locate your beacon quickly .
But what of the man who went missing in
Westernport a nd was found dead. The helicopter crew who just rescued you would have a
simple answer to that . They will each show you
the small, inexpensive strobe light which they
wear attached to their body or equipment. A
small strobe light can be seen fo r man y miles at
night 0
�Aviation Safety Digest
Aviation Safety Digest
139
139 ~-~
Dear Sir,
Dear Sir,
I am presently a private pilot with 140 hours
and am now looking forward to obtaining my
commercial
licence in the next few weeks. I
Survival Gear carried
have only been flying for a very s hort time (1
Let's get more wisdom into survival
1/2 years) and so the training I received for my
preparation.
licence is still fresh in my mind.
Could we have:
Of course one thing I noticed is that a lot of
1. Learned statements from 'The Authority', this training was concentrated on perfecting my
other authorities and experts on precisely what forced landings.
these items mean to them.
It was very reassuring to know that my
2. Comment from one and all about how they instructor could cut the power at almost any
understand requirements for first aid, emerg- time and that I would usually find a suitable
ency rations and water.
place to put it down.
3. Suggestions as to whether more or less items So now you would think I am fairly confident
should be included on the flight plan from that if the real thing happened , I would be able
under 'survival gear carried' (fire lighters, to run through my eme'r gency checks and if the
'space blankets'?).
problem could not be rectified, find a suitable
4. Suggestions as to what should be carried in clearing and bring it down for a safe landing practice in the aircraft under these item but I'm not. In fact, I'm rather worried because
now I realise something crucial to a successful
headings.
5. Accounts of real situations in which such items forced landing had been omitted: THE LANDor others have proved useful, useless or a ING ITSELF!
During all that time spent going through the
hindrance.
emergency checks, finding the next suitable
To start the non acrimonious process let me say
area to land, and making the correct Mayday
that most FIRST AID kits I have seen are a
calls, not once did we ever get below 300 ft.
joke, a financial rip off, and are often treated
Surely
what happens in the last 300 ft is what
as such - certainly rarely relating to needs of
determines whether you and your passengers
s urvival.
s urvive or not, and if you have never been
For example, tiny whisps of cotton wool, little
s hown what to do in these final seconds, the
bandages , bottles of antiseptic and other 'toys'
rest of the training before it is rather useless.
are unlikely to benefit by comparison with say
I must imagine there are different techniques
reversible adult / child artificial airway, robust
for putting aircraft down on different s urfaces,
bandages, pads and adhesive butterfly
for example:
'sectures' to maintain respiration and arrest
bleeding.
• How would you touch down on a flat paddock
as opposed to one on a hillside?
What sorts of rations for how many people for
how long?
• How should you put an aircraft down in an
area of tall trees? Should you stall it just
What weight/ load ratio, cost/length of preser above the tree tops?
vation ratio? Necessary? Minimal? Mandatory?
Desirable? Excessive/undesirable?
• How do you ditch an aircraft in water to prevent it flipping over?
Recent reminders in the Aviation Safety Digest
of need for rehydration in the air and on the
• Do techniques change for fixed and retractground (half a litre per half hou r and so on)
able undercarriages?
make a mockery of a two litre plastic bottle of
I have asked a number of people these kinds of
water (which may be remembered, and could be
questions
but none have really given me a satisfull 'if you're lucky'/sensible) to be s hared
factory answer. May be they have the same
between 2-4 persons during air work or private
problem I have or maybe they have never
flight - doubling up as meeting the additional
really thought about it.
need for water in an emergency. Should all
I would really appreciate it if you could proinstructors/pilots have basic first aid/survival
duce an article in a future digest about this
training? Examinable as part of licensing?
important a rea of air safety.
Available free on a voluntary basis at a ll training establishments? Would such training do
Yours sincerely,
more harm than good? If so, would we also be
Michael Badge
better off flying without training?
Donald Scott-Orr
Relevant articles are planned for the Winter
ASD 1989.
Dear Sir,
With reference to ASD 137 the section on permissible defects; that although the throttle
accelerator pump can be used for starting, it is
quite likely to cause a fire due to misuse and so
what you have written may be dangerously
misinterpreted.
The primer supplies a metered quantity of fuel
into the cylinder. The accelerator pump relies
on intake suction to draw the fuel not the cylinder.
By pumping the throttle and activating the
accelerator pump you can not meter the quantity of fuel. This fuel is sloshing around the
bottom of the engine from the intake manifold
and is downstream from the carburettor and
can lead to fire, during the start because of
backfiring.
If the primer is unserviceable, fix it. If it is
urgent to fly the aircraft, activate the accelerator pump only when cranking the engine to
minimize fuel accumulation.
Yours faithfully,
Elly Brooks
I fully endorse and totally agree with the comments made by Elly Brooks.
I would only add that if you MUST use the
accelerator pump, be aware of the potential for
an induction fire and if one eventuates or is
suspected, continue to crank the engine. This
has the effect of 'swallowing' the fire. A further
caution is warranted however. A starter jam is
also a potential result of a backfire and should
this occur the situation is exacerbated with the
obvious result. Following such an incident a
close inspection of the induction system should
be performed.
Bob Scott
Principal Engineer
Mechanical Systems
Civil Aviation Authority
Dear Sir,
In the current issue Winter '88 of Aviation
Safety Digest a very misleading suggestion on
Page 22 has been given in relation to compensating for the wind with two timed runs.
A distance travelled is not the average of two
dissimilar time/distance estimates. Average
speed equals total distance over total time.
Take the example of a 3600 foot strip and a 60
knot airspeed. Allowing for a 20 knot wind, the
ground speed one way equals 80 knots, ground
speed the other way equals 40 knots. The time
to travel 3600 feet at 80 knots equals 26.7 seconds, the time to travel 3600 feet at 40 knots is
53.4 seconds, giving a total time of just over 80
seconds. If you assume your average speed was
60 knots i.e. approximately 100 feet per second,
you would come up with a strip length of 4,000
feet, an error of over 10 percent.
It could be seen that taken to the limit, if the
wind was 60 knots, the downwind ground speed
will be 120 knots, time to travel one way 18
seconds, but you would never get back again as
your ground speed would be NIL. In other
words, to average 60 knots would be impossible
in a 60 knot wind. The higher the wind velocity, the greater the error.
Since many errors less than 10 percent have
added up to accidents in the past, I don't think
this is a very good method of estimating strip
length.
Yours faithfully,
P J McNiven
Quite correct, but the contributor was only
suggesting a method to 'estimate' distance more
accurately than 'eye balling ' the strip. As you
have, both h e and the comment provided by
David Robson cautioned against the margin for
error which will be influenced by significant
airspeed and windspeed differences. As long as
one is aware of the margins for error and
makes sufficient allowance, it is far better than
not making a calculation at all!
/
1
�
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,.
_,
''
...
~
.
~
~
Australia
1788-1988
ASD138
SPRING 1988
~-
�Aviation Safety Digest 1s prepared by the Civil
Av1at1on Authonty and 1s published by the
Australtan Government Publishing Service. It is
distributed to Australian licence holders
(except student p1/ots), registered atrcraft
owners and certain other persons and
organisations having an operational interest in
safety within the Australian civil aviation
envtronment
Distributees who experience delivery
problems or who wish to notify a change of
address should contact·
The Publications Distribution Officer (EPSD)
Civil Aviation Authoflty
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRAUA
Telephone (03) 667 2733
Av1at1on Safety Digest is also available on
subscnplton from the Australian Government
Publishing Service. There is a subscnption
form in this issue. Inquiries and notifications
of change of address should be dtrected to.·
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Subscnpt1ons may a/so be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Av1at1on Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Authority. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Contents
4
It started with a hisssss ...
12
A backward look at forecasts
14
It isn't easy being green
15
Still a pilot's greatest dread
19
Subscription form
Photo competition details and
entry form
23
A time to remember
26
Look out
27
'I believed I could climb above it' .. .
30
Trial and error
34
The times they are a'changing
... or are they?
37 AIRFLOW
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Civil Aviation Authority
G.P.O. Box 367,
Canberra, A.C.T. 2601, AUSTRALIA
Editor:
Editorial Assistant:
Graphic Design:
David Robson
Karen Hutchison
Lesley Boulton
Peter Garfield
Soussamth Nokham
Photographs:
BAS/
RAAF
Colin Owers
Neil Follett
Keith Meggs
S. J. Toomey
G. Taberner
©Commonwealth of Australia 1988
ISSN 0045-1207
R85/979(10) Cat. No. 87 1577 8
Pnnted by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRAUA
Art
§
Oh 'g' what can the matter be?
10
21
-=--
David Robson
Statement by Mr Collin Freeland, AO
Chief Executive, Civil Aviation Authority
l
Almost certainly all readers of the Digest are conscious of
the major changes currently taking place in the industry
and in the administration of aviation in Australia.
A new era is emerging with the forthcoming economic
deregulation of the domestic industry and the advanced
levels of technology now used in civil aviation in Australia
with the introduction of state-of-the-art aircraft like A320,
B747·400 and FSO. Paradoxically, this is happening at a
time when we are also facing problems with an aging fleet
of GA aircraft. Another growing concern is the increasing
evidence that Australia does not possess the pool of avi·
ation skills and expertise to cope with all these changes.
Shortages are evident in both the flight crew and aircraft
maintenance areas. We are also facing the need for a
major modernisation of our airways systems.
The Government has created the Civil Aviation Authority
(CAA) in response to the emerging complexities and diffi·
culties that were facing both the industry and the old
Department. The new Authority became operational 1 July
1988 and has responsibility for safety and operational
regulations as well as the business of providing air traffic
services.
The Authority has been designed to provide a more
responsive and flexible infrastructure to facilitate the provision of services and the regulatory framework for aviation. The main mechanism for achieving this will be the
removal of the Authority from the constraints of the Gov·
ernment budget cycle by placing its operations under the
control of a Board with membership from the business
community and the requirement that it operate in a business like way in providing its various services.
The Government has also established the Air Safety Regu·
lation Review for streamlining and modernising the operational and safety regulations and thus providing the
environment wherein the Authority and the industry can
work in closer co-operation to maintain Australia's outstanding safety record. The Government has made it clear
that the Authority will
be required to give primacy to safety considerations over
commercial ones and that ample resources, including
necessary legislative compliance tools, will be provided to
ensure that safety regulation and survei llance are in no
way diminished.
Both the Authority and the industry are facing challenges
and opportunities which if met with determination, imagin·
ation and co-operation can enrich the aviation industry to
the benefit of all Australians. For my part, I intend to see
that the Authority performs and provides cost effective
support to the travelli ng public and the industry. I believe
that, in this endeavor, I will have your support and
co-operation and that we can all lift our sights above our
own or sectional interests - to view the interests of the
community at large and that of the industry as a whole.
As far as safety promotion is concerned the CAA will
maintain the initiatives sponsored by the Department. The
Aviation Safety Digest will continue to perform its vital role
and will continue to respond to the safety needs of the
aviation community. It will also continue to be supplied
free-of-charge to encourage and promote informed dis·
cussion on flight safety topics.
The Safety Promotion area will actively follow the already
established program of videos, posters and brochures that
has been so well received by the industry.
The program of co-operative seminars and workshops with
AOPA and other organisations will continue and I believe
may need to grow to meet the increasing demand. We will
also be exploring ways for APT operators to become
actively involved in similar programs.
Aviation in Australia is entering an exciting phase - one
where significant technological and economic develop·
ment will bring new levels of operational efficiency - and
one where co-operatively we can set new levels of avi·
ation safety.
Editorial
C. W. FREELAND
The moving finger writes and, having writ, moves on ...
weaknesses of the human machine. I believe we can now
make significant progress towards safer flight - if each
of us strives to admit and to compensate for our individual
and collective characteristics. Time marches on but we
don't have to accept the same accidents as inevitable.
We can do something about it - individually.
Time marches on for editors too. This issue is my last as
editor of the Digest. I would like to thank you all for your
support, ei1couragement and constructive criticism over
the past two and a half years. I wish you smooth air, clear
skies, gentle breezes and safe arrivals for all your future
flights.
As the first fleet sailed into Sydney 200 years ago, we had
already experienced our first aviation fatality, two
balloonists kil led while attempting to cross the English
Channel in 1785 - that's right, three years before white
settlement in Australia.
It was over a hundred years later that gliders and then
powered aircraft were developed. However, we soon
learnt most of the ways to kill ourselves.
When we study modern day accidents there is little differ·
ence in the types of aviation accidents. The reason is
fairly obvious - the same humans with the same limitations are piloting, maintaining and controlling them.
It is mainly since the last world war that we have really
made great inroads into understanding the nature and
It.I~
L~
DAVID ROBSON
�Aviation Safety Digest
138
Oh 'g' what can
the ntatter be?
HE BUILDER/OWNER/ PILOT was making
his first visit to the Hunter Valley Gyro
Club's strip at Bowmans Crossing but was
well known t o many of the members.
He had a rrived at the strip at about lunchtime
and assembled his gyroplane.
At about 1700 the pilot took off and carried out
a demonstration of his machine's abilities, as he
often did at this type of gathering. He then flew
off to the south of the strip, out of sight of the
camp area. It was reported that he usually disappeared after his displays, to fly by h imself
for half an hour or so.
One of the club members away from the camp
area reported watching the aircraft leave the
strip and head south towards the area where
t he accident ultimately occurred. He reported
seeing it descend into wind (towards t he west)
very low, then climb steeply, make a s teep left
turn onto a reciprocal heading, descend out of
sight behind terrain, reappear climbing and
make another steep left turn back into w ind.
The aircraft again descended out of sight but
this tif!1e failed to reappear.
The witness rushed to the club area and
advised that he thought t he aircraft had gone
down. While vehicles proceeded towards the
area, another club member took off and located
the wreckage from the air.
The mature age pilot had previously enquired
about 'blackouts' and had told his friends that
he had occasionally felt 'woozy' during some
manoeuvres. He had asked to fly in a Decathlon
to see if the effect was the same as he had been
experiencing.
Aviation Safety Digest
138
After the official party had arrived and the
opening ceremony had commenced, the pilot of
the Mustang was cleared to position his aircraft
to the north-east in preparation for a low run
to the south-west over the field. As the a irfield
was about to be declared officially open, the
Mustang was cleared to s tart its pass.
As he rolled into a turn the pilot of the Mustang lowered the nose and descended with
increasing speed towards the strip.
The aircraft crossed the aerodrome boundary at
a height of 2-300 feet and continued to descend
to 150 feet. The speed was estimated at 250
knots during the pass and the pilot then pulled
the nose up 30 degrees, climbed to 1500 feet
and turned for a second run.
The aircraft then approached the strip at a
lower height than the first run but after being
warned about power lines, the pilot a bruptly
checked the descent. The aircraft was held
down to cross the field at 270 knots and again
climbed at 30 degrees. The pageant organiser
then requested an additional run anq t he pilot
acknowledged.
The aircraft continued its steep climb to about
1500 feet and rolled into an almost vertically
banked turn to the right. Almost immediately
the nose dropped and the Mustang flicked into
a roll to the right for two and a half turns as
the flight pat h changed to a descent angle of 30
degrees.
At a height of 800-1000 feet, the aircraft
appeared to hesitate on its back w ith the nose
down at 45 degrees, then fell in a tight descending spiral to the right making a bout four more
turns before disappearing from view. A few
seconds later black smoke rose from the direct ion of the lost aircraft.
Because the evidence of a number of witnesses
clearly indicated the turn at the end of the second run was quite tight, cons ideration was
given to the possibility of the pilot having lost
control as a result of blacking-out under high
flight loads or having become incapacitated in
some way. However, as he appeared to lose control early in t he 180 degree turn it was considered most unlikely that he wou ld have been
affected by 'g' force to any appreciable degree
by that stage. Furthermore, the onset of blackout is progressive and the condition can be
relieved promptly by easing the back-pressure
on the elevator controls, so reducing the load
factor.
This account is from a Digest of some years
ago. It is interesting to note the apparent
unawareness of the possibility of G-LOC without prior symptoms and the insidious effects of
mental confusion and possible disorientation
that may follow G-LOC.
As a result of all the above accidents which to
some extent are 'unexplained', I have asked our
Human Factors expert, Dr Harry Rance to
explain a few aspects of 'g' to us.
G-LOC the twilight zone
by Dr Harry Rance
The Bureau of Air Safety Investigation (BASI)
suspects that a number of otherwise unexplained accidents following acrobatic
manoeuvres, may have 'g'- related disorientation, confus ion or even loss of consciousness
as their cause.
It is therefore opportune to discuss some of the
e ffects of acceleration on the human body and
to present some data on acceleration levels
which can occur in ordinary, non-competitive,
aerobatic flying.
Finally the neck accelerates the head in the
new direction. While all this is happening the
pilot feels that his head and upper body are
pushing down when in fact the lower body is
pushing up against the inertia of the upp,er parts.
Acceleration may be applied in any direction.
Linear accelerations are usually described in
relation to the human body, by reference to
three orthogonal (right angled) axes passing
through the heart - lateral, longitudinal and
vertical. Vertical acceleration is correctly
abbreviated as Gz but more commonly, 'g' is used.
What is 'g'?
Load factor, or 'g' is the ratio of the acceleration applied to the aircraft compared to the
normal acceleration due to gravity. Hence it is a
measure of the effective weight that is felt by
the aircraft (and the pilot's body). Thus 4 'g'
represents a force which is four times that of
gravity.
Acceleration is of course, the rate of change of
velocity (speed or direction). It is associated
with changing speed or flight path and consequently, manoeu vring involves almost continuous changes in 'g'.
Accelerations may be of several types:
• linear - as in accelerating or braking
• radial - as in a turn (centrifugal force)
• angular - as in rotation about an axis (when
the ice skater spins).
In an aircraft we feel :
• linear accelerations when we take-off and
land, slip or skid and pull up or pitch down
• radial accelerations when we turn the aircraft
and in fact, we feel the resultant reaction to
both centrifugal force and gravity
• angular accelerations when we displace the
ailerons suddenly and cause the aircraft to
accelerate to a rapid roll.
Linear accelerations are the most significant
and of those, the accelerations through the vertical axis of the body have the most noticable
effect.
To change flight path the pilot a lters the angleof-attack of the wing which therefore generates
an excess of lift. This excess lift accelerates the
aircraft in that direction and causes a change in
flight path. The aircraft structure responds and
the seat (in the case of positive vertical acceleration) pushes the pilot's bottom in the new
direction . The pilot's spine is then compressed
as the lower body causes the upper body to
change direction.
Gy
Vertical acceleration is what you feel when you
go over a bump in the car. Lateral acceleration
is felt when you go around a corner. Longitudinal 'g' is felt when you accelerate or brake. You
rarely feel lateral 'g' in an aircraft because it is
banked like a motor-cycle - so the resultant
acceleration is felt as a vertical acceler ation.
The vertical axis is the most significant in
terms of physiological effects (except perhaps
for the massive longitudinal deceleration
experienced in a sudden stop!). With positive
acceleration ( + g) the ine rtial reaction (the
tendency to 'slump') is away from the head and
is often known as 'eyeballs-up' acceleration.
�Aviation Safety Digest
138
Aviation Safety Digest
138
Negative acceleration is consequently called
'eyeballs-down'. The response of the body to 'g'
depends on a number of factors including the
magnitude, direction, duration and raLe of
application of 'g' (also called the rate of onset).
Differences between individuals are also
important and may be critical. The important
features of a body's reaction to 'g' revolve
around the changes in effective weight of various parts of the body and the shift of body
fluids - particularly the blood supply.
At + 3g it is difficult to rise from the seat, at
+ 5g you cannot raise your head and at + 8g,
the hands cannot be raised although you can
still move your fingers.
Additionally, under these positive accelerations
the internal organs of the body are pushed down.
Body fluids, especially the blood , w ill tend to
shift down and p ool in the lower p arts with a
consequent reduction in supply and pressure at
the level of t he brain.
Normally at +lg, as you sit reading this
Digest , the blood press ure at the brain is
75-80% of the pressure a t t he level of t he heart.
If you are subjected to + 4.5g (a typical value
in a loop) the blood pressur e at the brain will
theoretically be reduced to 1 % - not enough to
support brain fu nction.
Further, the heart will be forced d own and
further exacerbate the situation. In practice t he
body compensates to mainta in blood flow to the
brain - pressure sensors in the main arteries
t o the brain sense the reduced pressure and as
a result the output of the he art is incre ased in
an attempt to keep up the supply of blood.
If + Gz is sustained fo r a long period, then
blood will begin to pool in t he lower limits and
lower trunk. The amount of available circulatory blood w ill be reduced and a consequent
reduction in flow to the brain will occur and
eventually lead to loss of consciousness.
This period of unconsciousness is followed by
at least 12-15 seconds of extreme confusion and
disorientation during which co-ordinated control of the aircraft becomes impossible.
The pilot will not remember the event - an
effect similar to the amnesia associated with
hypoxia or lack of oxygen. In addition you may
lose consciousness you will be aware of changes
to your vis ion. Initially there will be some loss
of peripheral v isual field (tunnel v ision) and an
overall 'greying' of the vision (loss of colour or
grey-out) followed by a total loss of vision.
These are a ll good reasons t o be careful before
any flying but more importantly, before flights
where you will be deliberately applying 'g'.
There is a lso a group of persons who arc placed
at risk by their activities. These people have a
high level of aerobic fitness which leads to a
low pulse-rate and blood pressure. These 'fit'
people actually start at a disadvantage when
exposed to 'g'.
What about negative 'g'?
Negative 'g' usually occurs w ith inverted or
'outside' manoeuvres and inverted s pins. The
body is less able to cope w ith negative 'g' and
quite low values will produce severe
decrements in performance. The disturbances to
the body are mainly related to the cardiovascular system. Exposure to minus-one g produces a fullness and pressure in the head which
is very disagreeable. Minus two may produce
small haemorrhages in the skin of the face and
neck. The blood pressure and flow of blood to
the head rises and the body responds by slowing the heart in an effort to compensate.
G-LOC the BASI Casebook
This article is a summary of a BAS! report, available to
interested parties from government bookshops. BAS/ will
be sensitive to possible cases of G-LOC in future and I
would appreciate advice from pilots of any similar
experiences.
Rate of onset of 'g'
I have been discussing the effects of 'g' but
there is a fw·ther factor - the rate of onset.
The prominence of the warning sign's and the
reaction time to compensate for the effects of
'g' reduce at high rates of onset of 'g' . In military aviation there have been instances of
pilots losing consciousness with out having any
of the visua l symptoms - and t hese pilots are
current and wear ant i-'g' suits.
T he rapid onset of 'g' prevents t he compensat ory mechanisms from having any worthwhile
effect. Loss of consciousness occur s w hen the
oxygen reserves of the brain are used up five seconds or less . This p henomenon has
become k nown as g-induced loss-ofconsciousness - or 'G-LOC'. In military experience, the levels have been as low as + 2g and it
is possible t hat many reports have been withheld because loss of memory has erased the
incident .
It s hould be pointed out that you don't need to
be in a high-performance jet aircraft to be susceptible to G-LOC. It can be experienced in most
aerobatic aircraft if you use high values of 'g'
or high rates of application - and it is accentuated if you pass from negative to positive 'g' in
a short time.
G-LOC can result in loss of con t rol and ground
impact during the period of lost consciousness
or subsequent disorientation and mental
confusion.
How to avoid G-LOC
• Be aware of the problem, the dangers and the
possible lack of symptoms.
• Avoid flying when other stresses exist.
• Practice the anti-'g' straining manoeuvre.
• Undergo a fitness program to build-up muscle
strength (as distinct from an aerobics
program).
Introduction
HE BUREAU of Air Safety Investigation
recently conducted research into t h e rat es
of 'g' onset and 'g' levels experienced by a
light aircraft pilot d uring normal aerobatics.
The objective was to relate data obtained from
the research to other data available f rom military authorities, in order to evaluate t he possibilit y or otherwise of a light aircraft p ilot
sustaining 'g'-induced loss of consciousness
(G-LOC) during aerobatics.
T he r esearch followed a fat al accident in
Australia during 1987 involving a pilot w ho
was practicing a n aerobatic sequence in a
Bellanca 8KCAB Decathlon aircraft.
The Bureau fitted a Decathlon aircraft w ith
appropriate instrumentation to enable acceleration values in three axes t o be r ecorded during
a sequence of ten aerobatic m anoeuvres.
Circumstances of the particular accident
which initiated the research
The purpose of the flight w as t o p ractice an
aerobatic sequence of t en manoeuvres in preparation for a competition. The pilot had
arranged for an observer to assess his performance from the ground, a nd there w ere s everal
other pilot witnesses t o the sequence of events.
It was known that the pilot intended to practice
the following sequence of manoeuvres:
A one-turn spin
Roll-off-the-top of a loop
270 degree horizontal t urn using 60 degrees of
bank
90 degree turn in the opposite direction using
60 degrees of bank
Loop
Reverse Yz Cu ban 8
Yz Cuba n 8
Aileron roll
Stall turn
Barrel roll
The pilot commenced aerobatics over the aerodrome, probably at 4000 feet, but apparently
stalled while inverted at the end of the second
maneouvre the 180 degree roll-off-the-top of
the loop. There was witness evidence that the
pilot had heard on the preceding day that it
was not possible to perform one and half rollsoff-the-top of a loop in a Decathlon and evidence that he was anxious to attempt such a
maneouvr e on the day of the accident.
After recovering from the inverted stall the
pilot continued w ith aerobatic manoeuvres, but
it was not possible to determine from the evidence whether he continued with the planned
sequence, recommenced the seque nce, or performed some other sequence of aerobatics.
Although it was considered impossible to perform one and a half rolls-off-the-top in a
Decathlon, there was no means of determining
whether t he pilot was in fact attempting to fly
such a maneouvre. Equally, an acrobatic pilot
would be aware that to length en the maneouvre
from a half roll to one and a half rolls would
require some combination of a higher airspeed
and/ or tighter loop p r ior to attempting t he
maneouvr e.
However , after completing a n um ber of
manoeu vres following th e inverted stall, the
aircraft w a s observed t o e n ter a steep spiral
dive which continued without a ny app arent
control input until it struck powerlines, caught
fire and fell to the ground, killing the p ilot.
Investigation
An intensive examination of the w reckage did
not reveal a ny pre-existing mechanical defect .
No evidence was found of any physical or
psychological fact ors w hich might have
impaired the pilot's flying a bility.
Consideration w as given t o t he possibility of
temporary loss of consciousness of t h e pilot
induced by the positive Gz forces associa ted
with the aerobatic manoeuvres being flown. The
question of G-LOC arose due to a n umber of
witness comments w hich strongly suggested
that the manoeuvres w ere flow n with unusual
t ightness. Such comments, if correct, would not
be inconsistent with an attempt, or attempts, by
t he pilot t o complet e a one and a half rolls-offt he-t op maneouvre.
Although t here was no evidence to show that
t he pilot in the Decathlon accident had suffered
G-LOC, equally it was difficult to ignore the
consistent witness evidence concerning the
tightness with which the manoeuvres were
apparently flown. For example, one pilot witness described some of t he high-g manoeuvres
prior to t he descent to the ground as being the
most excessive manoeuvres he had ever seen
during ten years of observing aerobatics over
the particular aerodrome.
�+9g
Aviation Safety Digest
138
Conclusions
The research undertaken by BASI was on a
relatively small scale due to limitations of
available resources. It would require a more
comprehensive experimental design, duplication
of measuring and recording devices and a much
greater degree of repetition across a representative sample of pilots before fully validated conclusions could be drawn.
Nevertheless the project successfully explored
in a broad-brush fashion the order of magnitude
of Gz changes and their durations during aerobatics in a light aircraft. It provided information useful to the particular investigation
and to the aviation community in general.
There can be little doubt that instantaneous
G-LOC is a real possibility in s uch aircraft.
International studies have revealed that the
phenomenon is a possibility in medically normal
individuals at levels as low as + 2 10 + 3Gz. In
recent surveys in the RAF, USN and RAAF
numerous occurrences of G-LOC have been disclosed involving aircraft similar to the
Decathlon in performance.
These latter surveys have shown that
approximately 20% of military pilots have
either suffered loss of consciousness themselves, knew someone who had, or had seen
someone lose consciousness. The possibility that
civilian pilots may have generally lower G-LOC
thresholds than military pilots cannot be
ignored, not only because of possibly different
fitness levels but because of a number of other
factors including a lower frequency of exposure
to Gz amongst civilian pilots. The effect, if any,
of aging on tolerance is largely unknown. Now
that we know it's a possibility in civil aviation
we must all be doubly cautious D
Protection due to oxygen
level in brain
•
G-LOC summary
+7g
I was interested to read an account in the EAA
magazine, 'Sport Aviation', of the flight characteristics of the BD-5. The pilot reported that the
manoeuvring flight characteristics were excellent because of the quick r esponse and low
stick forces required. These manoeuvring
characteristics were not completely without
fault , however, as he noted in the following
incident. During a photo flight , he was overtaking the photo aircraft (Cessna 175) at a high
closure rate. He elected to reduce speed by
executing a quick 360 degree turn. He banked
sharply and abruptly applied back pressure.
Instantly all reality with the outside world disappeared and he 'woke-up' in a slightly banked,
nose-down attitude. The 'g' meter iQdicated
slightly over + 3g. He was confused and
couldn't understand why he had blacked out at
such a low value of 'g' and why there were no
prior symptoms.
There was no narrowing of field of vision, no
grey-out - just instant loss of consciousness.
The next day an article in 'Aviation Week' discussed a new phenomenon known as GLC (loss
of consciousness due to 'g') which had been
experienced by fighter pilots in highly
manoeuvrable a ircraft such as the Fl5 and Fl6.
The loss of consciousness without prior cues
was attributed to rapid rates of onset of 'g'.
The following week the same pilot flew the
BD-5 in turning manoeuvres and noted that he
could go to about + 3.5g before some narrowing
of v ision occurred. In these turns he tightened
his stomach muscles (a part of the anti-g straining manoeuvre) and applied the 'g' load
gradually.
However, whe n 'g' was applied rapidly, GLC
effects set in as previously noted. Apparently
the BD-5 with its inherent quick pitch response
and low stick force gradient (approximately
2 lb/g as compared with about 8lb/ g for a typical GA aircraft) was capable of simulating a
basic problem encountered with some digitallycontrolled, fly-by-wire fighter aircraft.
This brings to light another aspect. If the stick
force gradient is high then it is likely that the
semi-conscious pilot would release the applied
' g' during the manoeuvre and therefore soon
recover. However, with a low stick force gradient and especially if the aircraft was trimmed
for a lower speed (higher angle-of-attack) then
the 'g' would be sustained during the period the
pilot was blacked-out and he may not regain
consciousness at all before impact w ith the
ground.
Further, the side-stick controller fitted to both
the F16 and the BD-5 may have some influence
in allowing the 'g' to be sustained.
+5g
......
__ .,..,,,,,,. ..... ---
+3g
.............
''
'
Protection due to
cardio-vascular reflexes
+1g
0
5
10
15
A.rapid onset, brief period
'snatch-pull' such as
corner or square loop.
B.smooth onset - sustained
such as normal loop
normal symptoms
20
'
\
''
''
....
25 seconds
C.rapid onset - sustained,
such as high 'g' sequence
of manoeuvres.
Few or no symptoms
before I oss of
consciousness.
CAUTION: The vertical scale is an "average". Some pilots
on some days may find their .band of symptoms is as low as +2g.
G-LOC is a known phenomenon but it's not as
simple as we first thought. The guidance I can
offer is:
• Be cautious about any aerobatic or h igh 'g'
manoeuvring routine.
• Practice the same sequence and gradually
work up to the full 'g' values.
• Fly one aircraft type for these sequences or
start from scratch if you have to use some
other aircraft.
• A normal aerobatic sequence can be flown
without requiring more than + 5g for more
t han five seconds. Be conservative about
higher values or more sustained periods.
• Try to avoid going directly from a high value
of negative 'g' to a high positive value. Use a
wing-over or similar manoeuvre in between .
• Condition your body to high 'g' slowly and
maintain a high level of medical and physical
fitness .
• For a display routine I set maximu m continuous power in level flight and trim the aircraft
for a high cruise speed. I don't touch t he trim
during the display as this gives me a constant
and continuous feel in terms of stick force and
stick position of wher e I am in relation to
applied 'g' and the stalling a ngle-of-attack.
• Try to plan the high 'g' manoeuvres so that
they end in an upward f\light path.
• Plan sequen ces to include low 'g' escape
routes in case you become disoriented or
'lose-t he-place'.
• Plan sequences for a smooth transition from
one manoeuvr e to the next and avoid high
r ates of onset or 'snatch ' manoeuvres.
G-LOC is a loss-of-consciousness w hich can lead
to loss-of-control due to the unconsciousness
itself or to the subsequent confus ion and
disorientation.
Like any other form of loss-of-control it
requires time a nd space from w hich to recover.
That time a nd space has to be allowed for when
you plan the routine - long before you take off D
�Aviation Safety Digest
138
Aviation Safety Digest
138
It started with a
hissssss ...
From Rainhill to Bass Strait: Aviation accident
investigation's railway heritage
James Walker is and has been the Historical Officer for
the Department for over five years. This article arose
because of James' academic interest in railway history
and his p rofessional interest in aviation history.
EFORE THE coming of mechanical transport, loss of life while t ravelling was normally cau sed by shipwreck - which did
not affect t he majority of the population. While
coach accidents were far from r are, the comparatively low speeds involved and lowness to
the ground, meant th at fatalities were unusual.
The advent of the railway was to change that
state of affairs. Reactions (and techniques)
which were adequate for a coach lu mbering
along at four miles per hour were not so with
trains running at forty miles per hour.
The problem was quickly made apparent on the
opening of the Liverpool and Manchester Railway when the President of the Board of Trade,
Huskinson , was run down by the 'Rocket'
driven by Joseph Locke. The ' Rocket' had no
brakes, and there was no time to pin down the
brakes on the carriages. Another major cause
was Hus kinson's panic on meeting an unprecedented s ituation.
The problems which confronted the early railway men were without precedent. There was
much to learn. The learning process was to be
accelerated by the inspecting officers of the
Railway Department of the Board of Trade. The
Department, including the Railway Inspectorate, was set up under the Railway Regulation
Act of 1840. The measure was received with a
great deal of opposition. Many engineers
resented what they regarded as interference.
Brunel claimed that no one would co-operate
with the inspectors. Daniel Gooch was later to
r efer t o 'minute and irresponsible inte rference.'
Their view was the common one. On the other
hand, George Stephenson, in a letter to the
President of the Board of Trade, dated 31
March 1841, supported the new regime. One of
Stephenson's reasons was the inexperience of
many of t he engineers and contractors engaged
in railway construction.
The inspectorate w as set up to inspect and certify new lines before they opened. The Act had
not given them any powers to investigate accidents. Indeed, statutory provisions on inquiries
were not enacted until 1871, although t he 1840
Act did require the railway companies to submit returns of all accidents involving personal
injury. This, however , did not stop inspectors
carrying out investigations. The first investigation of an accident involving p assenger facilities was in December 1841. Eight third class
passengers had lost their lives and seventeen
had been injured, when a Great Railw ay goods
train, w it h two passenger carriages attached,
ran into a 'slip' in Sonning cutting. The
inspector's report exonerated t he Company
from blame for the acciden t, but criticised t he
arrangements which had passengers travelling
in open trucks in a goods train.
The lack of statutory powers for these investigations forced the inspectors to rely on t he
co-operation of the railway companies and t heir
officers and employees. On t he surface, it is
surprisin g that such co-operation was so often
forthcoming. Two factors appear to h ave been
important in achieving this. One was the social
activity of the inspectors. Pasley, the second
Inspector-General, 'attended a party given by
the Secretary of the London & Birmingham
Railway, was the guest of the engineer whose
line he was about to inspect and drank champagne with the Secretary of the Great Western
Railway'. Other staff of the Department acted
s imilarly . The policy was eminently successful.
So successful, indeed, that some inspecting officers later joined the railway companies. Captain
Coddington , with the inspectorate from 1844 to
1847, then became Secretary of the Caledonian
Railway. Sir Henry Tyler became Deputy Chairman of the Great Eastern Railway . These officers were, in their turn, able to ease the
acceptance of other inspectors.
The other factor was the growing realisation
that the activities of the Inspectorate had benefits for the companies. Boards of smaller companies, made up of men with little knowledge of
railway construction and operations, often welcomed a report which was independent of the
companies' officials. Engineers and operating
staff found the inspectors, because of the wide
range of their activities, had much to contribute. Probably of more importance was that
inquests into accidents, usually technically
uninformed, could be highly embarrassing to
the companies - as the juries preferred, when
in doubt, to blame the companies. The report,
issued with official sanction by a competent
engineer, could, and often did, correct these
tendencies. However, to gain the benefits, the
companies had to exercise at least a minimum
of co-operation with the inspector and to give
at least lip service to the recommendations of
his report. Even so, if the recommendations
involved spending money, the companies would
normally try to avoid it.
Many accidents in the early years were caused
by boiler explosions. Two engine crews were
killed at Bromsgrove on 10 November 1840
when the boiler of their engine exploded. Year
after year there were further incidents. The
year 1864 saw three particularly bad
explosions. As corrective measures were
applied, the number of incidents decreased but
three men were killed, and another three
injured by a boiler explosion as late as 1909.
There were two major causes of the explosions.
One was excessive wear of boiler plates, the
other faulty safety valves. There were two
needs. One was for regular boiler inspections by
qualified staff. The other was for thorough prejourney checks of valves and gauges by the
engine crew. It was the investigation reports
w hich first drew attention to these two needs.
Another major cause, breakage of tyres, springs
and couplings, further emphasised the need for
inspections. Many people can still recall the
sound of the wheel tappers, checking the carriage tyres. What was being learnt was that
nothing could be taken for granted.
Causes which were the most puzzling for investigators were those involving decisions, or lack
of decisions, by operating staff, and especially
by footplate crew. Unfortunately, t hose who
made the mistake were often amongst those
killed. The accident causes could be divided
roughly into excess speed, failure to obey s ignals and lack of caution in foggy conditions. A
good example of the former was the accident at
Grantham on 19 September 1906. In this incident the driver and fireman were killed
instantly . It is_ still not known why the train
approached Grantham station, where it was due
to stop, at excessive speed. This was one of
three such accidents within a period of two years.
The classic example of the misreading of signals
was the Aisgill tragedy on 2 September 1913 ,
when the driver of an express mistook the
aspect of a distant signal, then ran through a
stop signal into the back of the preceding train.
November 1870 saw a good example of lack of
caution during fog at Harrow, when seven
people were killed, including the driver, who
was criticised in the report for driving too fast
in view of the poor visibility, and for overriding the signals which had been set against him.
Doesn't it all sound familiar?
When, in 1919, the rising number of aircraft
accidents caused extreme concern in the British
public, it was natural for the Government t o
turn to precedents. Consequently, the Accidents
Investigation Branch was organised in the A ir
Ministry under Colonel Clifton Brown of the
Royal Flying Corps. The Branch investigated
accidents to both civil and military aircraft. Its
position was formalised under the Air Nav igation Act of 1920, supplemented by the Civ il
Aviation (Investigation of Accidents) Regulations of 1922, 1925, 1930, and 1935.
In 1945, the Branch was transferred to the new
Ministry of Aviation, which was in turn,
absorbed in 1953 into the Ministry of Transport
and Civil Aviation.
Throughout the period to World War I, the rail
inspectorate had relied on persuasion, rather
than on compulsion, even when the means of
compulsion existed. The heads of the inspectorate r esisted pressures for more direct government control. They largely saw it as a question
of responsibility. Direct supervision or control
by the government would divide, and so
weaken, responsibility. The inspectors believed
that final responsibility must remain with the
railways themselves. All the government could
do was to try to bring about reform by persuasion and pressure of public opinion.
Because of this, the Board of Trade commenced
to publish the accident reports and the annual
accident statistics. There were two reasons for
this. One was to apply pressure on the culprit
managements. The other was to spread the
lessons learnt as widely and quickly as possible.
(This of course is the same reason for publication of the Aviation Safety Digest .)
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138
This approach proved itself on the railways of
Britain. By the time many safety measures had
been enacted by Parliament, they were already
in widespread use, due to the urgings of the
Railway Inspectorate. Similarly, new safety
practices are generally introduced in civil aviation long before their legal enforcement.
In Australia, we followed the UK precedents.
From the start, officers of the Civil Aviation
Branch investigated aviation incidents in Australia. In 1927 the Air Accidents Investigation
Committee was formed. In 1946 the Accident
Investigation Branch was formed in the Directorate of Air Transport and External Relations.
The same year also saw the creation of the
Accident Studies Branch of t he Directorate of
Air Navigation and Safety.
But it took a little longer to learn from the Railway Inspectorate experience, which had shown
the need for close co-ordination between those
looking a t general trends and those investigating particular incidents. This was corrected in
the 1952 reorganisation when the two Branches
were combined into a new Accident Investigation Branch, which reported to the Director
General. Early in 1982 there were proposals to
expand the Air Safety Investigation Branch into
a multi-modal Investigation Branch, similar in
oper ation to the National Transportation Safety
Board in the United States, but this proposal
was dropped when the Department of Transport split in May 1982. Under the new Department of Aviation, the Branch became the
Bureau of Air Safety Investigation, with direct
reportage to the Secretary of the Department,
and some direct access to Minister. We have
now reached the situation where an active
Safety Promotion Section has been formed and
will be part of the Civil Aviation Authority.
BASI will retain its independent, purely
investigative role.
Australia's first fatal aviation accident was on
28 March 1917 when a Sopwit h biplane crashed
into Port Phillip Bay.
The pilot, Basil Watson, was killed.
In the years 1931 and 1932, a total of 276 accidents, forced landings and mishaps occurred. Of
these 13 accidents we re fatal and 18 people
wer e killed. There were 205 aircraft on the
register, of which 173 had airworthiness certificates. There were 601 licensed pilots and 170
government aerodromes and emergency landing
grounds.
Now, over fifty years later the aviation scene is
far more complex. Nevertheless , Australia has
achieved an e nviable aviation safety r ecord one which will require continuing vigilance [and a t apping of wheels] D
A backwards look
at forecasts
'
Bureau of Meteorology
ETEOROLOGICAL services to civil aviation commenced around 1920. The early
_ services were very generalised, as can be
seen by the forecast provided to the aircrew of
the 'Southern Cloud' for its fligh t from Sydney
to Melbourne on the morning of 21 March 1931:
'Cloudy and unsettled with rain and thunderstorms from the north at first, but with a cooler
southerly change over the state from the west
over the weekend'.
The forecast was in fact provided to the pilot
at Mascot by phone from the Sydney Weather
Bureau very early that morning and based on a
weather ch art of 9am the previous day. After
the aircraft departed, the subsequent observations showed conditions were much worse
than originally anticipated , but with no
on-board radio there was no way of conveying
this vital information to the crew . After passing
Goulburn, the aircraft would have encountered
severe frontal conditions causing massive drift,
low cloud, squally winds, severe icing and turbulence; the aircraft crashed into the Snowy
Mountains, the wreck not being discovered for
another 27 years.
Following the crash of the 'Southern Cloud'
more specialised services wer e provided to civil
aviation. Individual forecasts were provided to
each flight and these included information on
wind and cloud along the route. Until 1948
most aircraft operated below 10 OOO feet, but in
the next 11 years, they flew at increasingly
higher levels. Appropriate forecasts were
required for these new type of operations and
the emphasis ch a nged. Until the advent of the
turbo-jet era in 1959, aircraft were still
frequently operating in cloud. Jet aircraft were
above most of the weather when operating at
their normal cruising level, but they frequently
encountered jet-stream strength winds.
A remarkable growth has occurred in aviation
in Australia in the last 30 years; there has been
a four-fold increase in the number of aircraft
on the Australian register. To cater for the
rapid growth and diversification of aircraft
types there has been a trend from individual
forecasts to advices covering many flights. Area
forecasts are provided for 35 areas for low
level users; these provide forecast information
on the temporal a nd spatial variations in all
elements of concern.
The type of information contained in present
day low level area forecasts would have been of
inestimable value to the crew of the 'Southern
Cloud' on that fateful day in 1931.
For higher level users pictorial significant
weather prognoses are available.
In addition:
• In 1957 SIGMET advises were developed to
provide warnings of hazardous meteorological
conditions for all aircraft.
• In 1970 a VOLMET broadcast was developed
to meet the ever-increasing demand of international jet aircraft for information on conditions a t the terminal aerodrome.
• In 1970 a system of routine forecasts was
designed for major a ir routes.
The safety record for RPT operations in Australia is very good. The loss of the Viscount aircraft VH-TVC in storm-associated turbulence
close to Sydney airport in 1961 emphasised the
importance of weather conditions in the terminal area. Justice Spicer in his Report to the
Board of Inquiry on the accident recommended
that 'when thunderstorm activity is present the
approach controller should be provided with
the best current weather information pertinent
to the assessment of the changing weather
pattern.'
'
This resulted in the use of ground based radar
to provide information on the location of severe
turbulence areas within 60 nautical miles of
major airports.
In 1963 a Joint Approach Control Meteorology
Advisory Service was established and as its
name implied it was a cooperative advisory service provided by the mutual efforts of the Air
Traffic Control Offers of the (then) Department
of Civil Aviation and Meteorological Officers of
the Bureau of Meteorology. The service evolved
to the now-named Terminal Area Severe Turbulence (TAST) service. This service is currently
being revised to provide an automated forecast
of hazardous airspace.
The new service provides a colour display basically divided into two parts. The left part of
the display shows the current weather radar
return in six colour intensity. By continual
updating, the changing pattern is displayed and
the growth and decay of storms can be
monitored.
The right part of the display contains the
actual T AST advice. The details of the display
have not been finalised yet but one possible
form of display involves the core of the forecast severe turbulence area and a buffer being
shown by two distinctive shades. This display
will be updated at very frequent intervals and
consequently will provide the best possible
advice for departing and arriving aircraft D
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Aviation Safety Digest
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It isn't easy being
green
An experience of a lifetime. by Graham Gillies
I had my own WAC so I grabbed a scale and
made a couple of quick calculations. We still
had two hours to go, at this ground speed.
'What's the endurance?' I asked again.
'Three hundred and fifteen litres at 1 litre per
minute= 315 mins, 5 hours 15 minutes endurance.' This seemed enough, but the left main
gauge was getting low. I pointed it out. No
response from him.
We were now approaching t he cloud. I couldn't
see many instruments. 'Are you going to fly
into that?' I asked, hoping he would say no. In
we went - rain, turbulence, darkness, flashes,
terror. At one stage I thought the aircraft was
in a vertical dive. I had to force myself to look
at t he instruments on his s ide, for reassurance.
We weren't vertical, thank heavens. I'm not
religious but I was on the verge of conversion.
'Arc you instrument-rated?' I mumbled dreading the answer.
'Night VMC,' was the answer. Night VMC in a
thunderstorm! I thought it was all over. I was
surprised how calm I was.
·
'I think we'll do a' 180' ,'he said. I nearly cheered.
HE SCENE OPENS ... it was to be a four
hour flight in two stages. The first was
approximately 70 minutes. The tanks were
filled and jerry cans containing eighty litres of
fuel were put in the rear of the p assenger section and strapped in securely. A preflight
inspection was carried out.
The aircraft, a 1968 model Cherokee six, was in
good shape.
My first worry occurred when the young pilot
(19) started the engines with the aircraft still in
the hangar - and simply 'drove' it out.
We weren't heavy and the long, grass runway
presented no problems. The first stop, we had
telephones and fuel available, plus there was a
RPT 'Bandit' on the ground.
My pilot made a decis ion to top up the ta nks,
then changed his mind as, 'We've only used
eighty litres'. I asked if that was ample and
was assured it was. I asked the RPT pilot what
the weather was like on our track and he asked
if we were IFR. I asked my pilot. He said,
'limited' . The RPT pilot offered to transmit the
weather to us as he would be on our track and
well ahead. 'Thanks'.
We took off at four thirty into clear skies. On
the horizon, I could see build-ups and they were
pretty high s o I made reference to them. Then
the engine stopped (the right main was dry).
The build-ups were getting bigger and pinker as
the s un went down. We were on track and all
was apparently well. I made a subtle hint that
we should 'maybe' track toward the coast - a
bit north of our present track.
I don't think he liked hints from an old bloke
like me, especia lly a helicopter pilot. 'What
would he know?' , he probably thought. We
pressed on. Darkness arrived.
We broke out to reasonable visibility and
located ourselves over the ground. Relief
abounded inside me.
I persisted about the fuel contents so I flew
while he did his calculations. He said we were
fine. I suggested an alternate. He said we were
okay.
Ten minutes later he said we would land at an
aerodrome enroute and put in t he 80 litres contained in the jerry cans.
'No you won't' I said, 'No lights'.
'Oh,' he said, 'I think we'll divert to the coast'
'Good idea,' I said.
We didn't cha nge track and w hen asked, he said
he would p refer to track via his reporting
point. I stressed our fuel contents. We tu rned .
Amending our planned route brought a bit of
pressure to bear on my young friend. I think
the controller had a sense of problems.
'Endurance?' he asked, 'POB?' 'Alternate for
our new destination in case lights U/S?'
'Why were we NGTVMC in these conditions?!'
- a very inquisitive person . My pilot lied about
our endurance.
We would be lucky to make our new port, let
a lone an alternate. The controller was going
home. We had no one to talk to in case of an
emerge ncy .
By now the tip tanks were both on 3-4 gals, the
right main was empty, the le ft just below ten
US gallons.
In the distance, I could see the flicker of a beacon rotating. 'The re's our aerodrome,' I said ,
'tha t beacon is on a tower there.'
'There's no tower there', he said .
'Not a control tower, a tower for a beacon that
is activated by the P.A.L.' I replied.
'Never seen one of those' he said.
'Believe me. Track to it'.
Bright lights of a town appeared to our left.
'Thats it, over there' he proclaimed.
'Believe me. Track to that light over there.' I
convince him to track my way but he doesn't
really believe me.
We are at 4000 ft over sea-level terrain a nd he
flies straight into a rain cloud! I'm counting the
cc's of fuel and he flies into cloud! The needles
are having a race to empty.
Still a pilot's
greatest dread
'Descend, Please.'
We descend and break out 3 0 degrees north of
track, more cc's wasted and I'm starting to hate
him and the 80 litres in the back of the cabin.
The town comes into view and t he runway
lights appear, we are at 2000 ft, three miles out
and intercepting for a straight-in from 20
degrees off the centreline. It's raining and the
town lights keep disappearing behind low cloud
My ex-friend turns right.
'What are you doing?' I nearly scream.
'Turning downwind' he says.
'Go straight in, we don't have any fuel in the
tanks.' For God's sake, we've made it this far
a nd he's going to run out of fuel in the circµit area!
'1 got into trouble once' he reckons, 'for not
doing three legs.'
We're committed to a circuit, downwind in rain
and base.
I said 'Turn on t he fuel pump. If we run-out I'll
select a tip tank. You just fly it'. Final, two lots
of flap and all needles hit the stops. We are
almost a glider. Over the threshold, on the
ground, off the ground, floating, three legs of a
circuit and we land w ith 20 knots of wind up
the bum. We're on the ground and I'm not dead.
315 litres. 315 mins - but empty in four hours
We put in the 80 litres in the drizzle and called
a refueller. He puts in 200 litres.
The pilot couldn't believe it because, ' My dad's
Che rokee gets five hours '. He'd never timed the
fuel flow , he just ASSUMED that aircraft of the
same name got the same endurance. He found it
hard to believe that ALL aircraft are d ifferent,
even the same type can have vastly different
characteristics: flight, fuel and controls.
His assumptions on that night, had his passenger been ignorant of things, would probably
have been fatal.
We landed one hour s hort of our destination
with less than 20 litres spread through three
tanks. I'll bet the consequences still haven't
sunk in.
[J don't know the identity of our young P.I. C.
However if you do, please take him to one side
... and brief him thoroughly.] D
~ HE
STRUCTURE of an aircraft is continuously under stress and the stress is continuously changing - for example as a result of
normal manoeuvres or turbulence. Some parts
are more h ighly stressed than others and it is
not always deliberately so - for example a
small nick in an otherwise smoot h component
can lead to a concentration of st ress and an
accelerated reduction in str ength.
The aircraft sttucture can accept an enormous
number of changing loads and provided they
remain within norma l limits, the structure will
not show any deleterious effects even though it
may be suffering undetectable fatigue damage.
However, as the structure a ges, the accumulated fatigue damage may then begin to show as
visible or insidiously hidden cracks and depending on the criticality of the component, may
eventually cause complete failure.
One preventative meas ure is for the life of the
aircraft to be limited to a value safely below
the life at which degradation of strength is estimated to occur.
These days aircraft s tructures are required to
be 'fail-safe' or 'damage tolerant' and nondestructive techniques have been developed to
detect the potential cracks before they reach
the stage of critically affecting the strength of
the structure - provided of course that you
know where to look for them!
Further, a complex monitoring system has been
developed between regulatory authorities,
manufacturers and operators to exchange information on particular aircraft t ypes in service so
that catastrophic failures can be avoided.
But it wasn 't always t hus:
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Aviation Safety Digest
138
[Incidentally, wood does not fatigue like metal
and hence the whole concept of fatigue was a
revelation.]
The Stinson was the first fully recorded civil
aircraft crash in the world, known to have been
caused by primary structural failure as a result
of fatigue. Canada had imposed a life of 14
years on metal aircraft as an arbitrary limit
and was the only regulatory body at that time
to have any limit.
It was January, 1945 and the Stinson, one of
two modified to a twin engined configuration,
was taxying at Essendon for a flight to Kerang.
It was early morning and the aircraft carried
two crew and eight passengers.
The Captain and First Officer were experienced
and the aircraft was fully serviceable and correctly loaded.
Departure was normal and about an hour later,
at 0807 hours, the DCA Aeradio station at
Essendon received a routine message from the
aircraft that operations were normal - 'I have
nothing to report', it said.
Residents of Spring Plains, about 54 miles
north-west of Essendon, saw the aircraft about
ten minutes later on track at an altitude of
about 1000 feet, due to the cloud base. The visibility was good but conditions were gusty and likely turbulent. The aircraft was flying
normally, although the engine noise was loud.
The aircraft passed over a fairly steep-sided
gully. Suddenly and without warning, the port
outer wing came away. The aircraft immediately rolled over and hurtled to the ground
about three quarters of a mile further on. In the
dive, various other portions of the aircraft separated. Just before impact, the tailplane was
seen to be thrashing about - there was nothing
to suggest that this had started before the wing
separated.
The aircraft burned on impact and all were lost.
The investigation by DCA experts and the
Council for Scientific and Industrial Research
concluded that the failure had begun as a
fatigue crack which propagated from a cavity
in a weld which attached the lower main spar
to a support lug.
The cavity was under the surface of the weld
metal and could not have been seen by eye. The
cavity set up a stress concentration which
started a fatigue crack in the weld metal and
under the resulting further stress concentrations, the crack progressed in the parent
structure. Eventually the residual strength of
the component deteriorated to the extent that it
could no longer support normal flight loads and
this resulted in the catastrophic failure of the
spar.
The recommendations of the investigation panel
were significant:
• all welded steel, highly stressed members
were to be Magnaflux tested - for detection
of invisible cracks
• the accident was to be reported to the Australian Council for Aeronautics with a request
that they undertake a study into fatigue of
airframe structures
• the remaining Stinson be grounded
• that the outer wing panels from the grounded
aircraft be examined by CSIR and DCA to
further knowledge of fatigue damage
• that DCA obtain recorders to survey conditions of turbulence on the Australian air
routes - a knowledge of such loads would
then allow comparison of predicted fatigue
lives with the environmental conditions of
other countries.
Thus the world was introduced to the concept
of metal fatigue - in this case welded steel fittings. The problem though was to predict the
safe life of other metal structures - most aircraft were now made of stressed skin aluminium construction.
Aircraft designers generally adopted a 'safe
life' philosophy. That is to say that the life of
airframes were very conservatively estimated
by applying a safety factor to the predicted
failure areas. For example the wing root fittings were generally considered to be the
highest load-bearing members. If these fittings
were tested in a rig which could represent the
in-flight loads and if they showed signs of
deterioration or failure after the equivalent of
say 30 OOO hours, then the structure would be
approved for a safe life of 6000 hours (a safety
factor of 5) after which time the fittings had to
be retired from service or had to undergo periodic inspection to ensure there were no cracks
developing.
The validity of this safe-life theory depended
on two factors:
• that the selected item was the critical item
• that the loads used to simulate the in-flight
conditions were in fact representative of the
in-service life of the a ircraft in all parts of
the world.
Thus the safe-life design philosophy was
backed up by other inspections for signs of
fatigue in other areas and data was gathered on
in-flight loads.
Research was also undertaken with full size,
complete airframes in hydraulically operated
test rigs to verify critical load paths and likely
failure items.
However, the system was not foolproof:
In October 1951, near Kalgoorlie, a Dove aircraft experienced a catastrophic failure of the
centre-section spar boom. This accident caused
a world-wide re-appraisal of aircraft design
standards and led to a comprehensive fatigue
research program by DCA and ARL.
But fatigue prediction was still an art rather
than a science:
On the thirty-first of December 1968, a
Viscount airliner taxied at Perth airport, bound
for Port Hedland on the north-west coast.
The flight was planned to cruise at FL 170 and
the EET was 189 minutes. The aircraft carried
a crew of four and twenty two passengers.
Takeoff and departure were normal and the
Captain advised that they were climbing at an
IAS of 155 knots instead of the planned 175
knots, due to turbulence. Cruising level was
amended to FL 190. The flight and all communications were normal and at 1120 hours they
advised their intention to commence the descent
into Port Hedland in three minutes tirfle. At
1134 hours they reported passing 30 miles DME
and had left 7000 feet on descent. This was the
last transmission received from the aircraft.
Two witnesses saw the aircraft descending rapidly and steeply but did not sec any impact. At
1223 hours a searching Cessna 337 located the
burning wreckage of the Viscount, close to
planned track and 28 miles south of Port
Hedland.
There were no survivors.
The aircraft had a total of nearly 32000 hours
and 25000 landings. It had been Correctly maintained and was loaded within AUW and CG limits.
There was no evidence of any dangerous cargo
being carried on this flight.
The Viscount had an aluminium, stressed skin
structure. The wing carried a single main spar,
with leading and trailing edge members and a
stressed skin.
The spar alone was designed to carry 90% of
the overall wing bending moment and shear force.
Weather conditions were generally good with
moderate turbulence forecast and experienced
between 5000 and 7000 feet, during the climb.
�Aviation Safety Digest
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138
There was no other significant turbulence
experienced and there was no cloud en-route,
nor significant winds.
As a result of earlier accidents there was by
now a requirement for all RPT aircraft to be fitted with a flight data recorder. The recorder
had been damaged on impact but was found to
offer a usable record of the flight. The flight
apparently proceeded completely normally to
the point where it passed an altitude of 7000
feet in the descent into Port Hedland. After
this, there were gross variations in vertical
acceleration, heading and indicated airspeed
while the rate of descent increased to an average of 14000 fpm until ground level.
The trace of normal acceleration ('g' forces)
showed the tu rbulence experienced during the
climb, where deviations of approximately plus
and minus 0.5g were recorded - relative to the
normal level of plus lg in level flight. After the
7000 foot descent point, it showed accelerations
from nearly plus 3g to minus 3g.
The most significant observation made from
examination of the wreckage was that the
whole of the starboard wing, outboard of the
inner engine but including the outer engine, propeller and supporting structure, was found
some three thousand feet away from the main
point of impact. The tail section and rear fuselage was found some 1600 feet from the main
point. This evidence suggested that there had
been a failure of t he aircraft stru cture before
ground impact.
The components were then r emoved for closer
examination in the laboratory. It was evident
that failur e of the tail section and rear fuselage
were caused by an overload and there was no
evidence of a ny prior defect. The starboard
tailplane a nd elevator had also failed in flight
as a result of being struck by sections of the
separating w ing s t ru cture.
An intensive search w as then carried out for
missing pieces of the w ing structure. All of the
fracture surfaces evident on the sections of the
main spar boom visible above the ground, displayed overload failures consistent with ground
impact but, immediately adjacent to the w reckage of the number 4 engine, there was a large
ground indentation from w hich three sections
of the main spar boom protruded. [The spar
booms , upper and lower are the main loadbearing sections of the spar as distinct from the
spar web which keeps the booms apart, i.e. if
the spar was an 'I' section then the upper and
lower horizontals would be the booms and the
vertical line would be the web.]
After a digging operation lasting two days,
three sections of the boom were recovered from
very hard rocky ground and one section which
had been driven about three feet into the
ground was identified as being the most inboard
section of the lower spar boom in this group of
wreckage.
Despite considerable damage as a result of
being driven into the hard ground, t here were
unmistakable s igns of fatigue on t he fracture
s urface. The face of t he structure which mated
with this area was subsequently located and
showed even more distinct s igns of fatigue. It
was determined that t he failure had occurred at
a point coinciding with the outer edg.e of the
number three engine nacelle. The fatigue cracking and subsequent failure had occurred
through a bushed hole - one of a group o~ five
which passed through the spar boom at this
point to carry the engine nacelle support t ube.
This particular bush had been distorted on
insertion and had scored the hole. This created
a nucleus from which a premature fatigue crack
subsequently grew.
Tests by the Aeronautical Research Lab?ratories in Melbourne showed that t he fatigue
crack extended over some 85% of the crosssection of the boom, at the time of the ultimate
failure.
It was originally estimated that the safe life of
the boom using a safety factor of 5 for airborne
loads was 11 400 flights - and yet this boom
failed after only 8000 flights. A very detailed
examination into the cause of the failure was
undertaken and suffice to say that the life of
t he spar was critically dependent on the way in
which the hole was bored and the way the bush
was inserted. Alt hough this item triggered the
fatigue crack, it was also found t hat other
Viscounts suffered similar fatigue damage.
1
Five is sues $A 16 .0 0
o r ove r thirty years, the Aviation Safety
Digest has been an integ ral part of
Aust ral ian aviation.
In July 1986, responsibility for the Digest wa s
transferred from the Bureau of Air Safety
Investigation to the Flight Standard s Division of
the Australian Department of Transport a nd
Communications. This move reflected the
perception that c ivil aviation may have reached
the limit of accident prevention th rough
regulation and that the way forward is through
increa sed emphasis on safe ty educa tion in
general, and the 'human factor' in particular.
Rather than just draw lessons from accident
investigations, the Digest wil l inc reas ingly seek
I
As a consequence of this accident and the subsequent investigation, all Viscount spars were
inspected. Several Viscounts overseas were
found to h ave fatigue cracks and required spar
boom changes. The safe life was reduced to
7000 flights.
By the way, the flight load spectrum for Australian conditions had been measured and used
to calculate the safe life of t he Viscount spar
and a safety factor of 5 h ad been used for calculating airborne 'damage'.
The Viscount was lost as a result of fatigue
cracking which started around a tiny hole but
more importantly many lives were saved as a
result of the international cooperation which
had developed in the study and protection
against fatigue failures. But for this exchange
of information several other Viscounts would
almost certainly have suffered similar catastrophic failures.
Later developments have led to the concept of
'damage-tolerant' design which is a totally different way of predicting t he life of airframes
- but that's another story in the continuing
development and maintenance of safe aircraft
operation D
Onclud;ng su,face postage)
to influence pilot behaviour by pos itive
reinforcement of sound techniq ues . It will
examine all aspects of piloting and publish
formal results as well a s 'the tricks of the trade' .
The 'crash comic' will become a 'how not to
crash' comic.
Anyone with an interest in a viat ion will benefit
from tapping into this unique source of the
accumulated wisdom of the profession and
the latest re search into aviation safety in
Aust ra lia . Indeed , a nyone with an interest in
high technology and the roles and limitations
of the human operator will find this publ ic ation en lightening .
------------------------------------------ ~-
Feeling a little query?
I
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The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others.
Write to:
AI RFLOW
A viation Safety Digest
P.O. Box 367
CANBERRA A.C.T. 2601
Australia
�Aviation Safety Digest
138
Pomp and Ceremony
A tinte to
TO: Photographic Competition
Aviation Safety Digest
Civil Aviation Authority
GPO Box367
Canberra, ACT 2601
re01e01ber
ENTRIES CLOSE: Last Mail,
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14 April 1989
Results will be published in the
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ENTRY FORM FOR THE
DIGEST PHOTOGRAPHIC COMPETITION
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ENTRIES CLOSE: Last Mail,
TO: Photographic Competition
Friday,
Aviation Safety Digest
14 April 1989
Civil Aviation Authority
GPO Box367
Results will be published in the
Canberra, ACT 2601
Spring edition of the Digest
Dear Sir,
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details are as follows:
Category of Entry:
. . . . .. . . .
Film Size and Type:
Caption or Title:
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(Signature)
(Date)
Official Secrets?
HE DH-9 was approaching to land at Pratts
aerodrome near Geelong. When the aircraft
was at a height of about two feet, the cadet
pilot noticed a cow, which had been running
away with about twenty others, turn around
and come back towards the landing area.
The pilot immediately opened the throttle but
failed to clear the cow. The impact broke the
port undercarriage strut. Because he was
unsure of the extent of the damage, the pilot
elected to land ahead and 'pancaked' from a
height of six feet.
After exiting the damaged aircraft, the pilot
made contact with the officer of the watch to
report the accident and then returned to his
machine.
The local senior constable s ubsequently arrived
and asked for the pilot's n ame and a statement
of what h ad ha ppened. The pilot refused to
give him either but requested that the cow
which had internal injuries, be attended to.
The pilot was then approached by a local
reporter who tried five or six times to get the
pilot to discuss the accident. He again rigidly
refused to provide any information.
(The cow was later valued at between seven
and eight pounds.)
In April 1927, a RAAF formation was providing
top cover for HRH The Duke of York. The
leader of the formation was briefed to lead a
vie of seven DH-9 aeroplanes from Point Cook.
His instructions were to escort the Royal party
from the time of their leaving HMS Renown
until arrival at Federal Government House.
The aircraft were to remain in close formation
for the whole time and were not to come within
2000 feet of the Royal party - in case the
noise of the engines interfered with the
ceremonies.
These instructions were observed and when the
Royal party arrived at the gates of Government
House, the leader of the formation decided to
return to Point Cook.
At this time the formation was flying at a
height of about 1000 feet. The leader of the formation then dived as he passed over St Kilda
Road - with the intention of giving a final salute. The lowest point of the dive was about five
or six hundred feet.
The leader then pulled up into a steep climb
and as he passed nine hundred feet, he looked
back to see if the following a ircraft were still in
position. He saw that the two rear machines on
his starboard quarter were falling apart, evidently after a collision.
One of these almost immediately went into a
vertical dive and disappeared through the roof
of a building about three hundred yards West
of the gates to Government House. Immediately
after this machine disappeared , a sheet of
flame shot through the roof of the building.
The other machine, which appeared to have a
badly damaged port wing, commenced a flat
spin and it appeared that the pilot was strug~ling to regain control.
Finally it crashed into a street about fifty yards
east of where the other machine had hit.
It appeared to other members of the formation
that both aircraft had been lagging and that
one of them tried to regain position a n d pull up
into the climb at the same time. It was possible
that the other aircraft was then obscured by
the upper wing.
All crews were killed.
Up to a point ...
Having received its flight clearance the DC-3
tax ied out to the holding point.
It was four minutes past two in the morning. It
had been raining heavily but had now eased to
a light shower. The lights on a nearby mast,
nearly three miles away were visible as were
lights on another hill six miles away. Main
cloudbase was 8000 feet.
�Aviation Safety Digest
138
One wing dropped, was raised and then the
other dropped until the aircraft was almost on
its side. One witness believed that the engine
noise died away at this point and the comparatively undamaged state of the airscrews
suggests that the engines were delivering little
power on impact.
When it was still some appreciable height above
the ground, t h e aircraft assumed a flat attitude
a nd eyewitnesses emphasised how it appeared
to then drop most steeply and on an even keel
until it hit the ground. Examination of the
wreckage and s urroundings revealed that the
aircraft had struck in a most unusual manner in
that there was practically no indication of forward movement.
The aircraft was found to be loaded beyond the
permissible aft CG limit. Also the t rim tab was
in a setting of three degrees nose-up whereas a
setting of ten degr ees nose-down was appropriate to aft CG positions.
The CG in this aircraft would also move further
aft with undercarriage retraction. There would
be a further nose-up trim change due to the
change in the drag vector associated with the
gear retraction.
The t hree crew, sixteen adult passengers and
two children all perished and the a ircraft was
destroyed by impact and fire .
Other company pilots had reported difficulty in
controlling this aircraft during takeoff when
the CG was known to be in the vicinity of, if
not beyond, the aft limit, but on no known
occasion did the CG approach its position on
this flight.
It was also observed t hat w hen the aircraft
began to climb steeply, the fuel and baggage
would move as far rear ward as they could
thereby further moving the CG aft.
The aircraft appeared to take off normally and
became airborne after about 1750 feet. By the
time it reached the end of the 4000 feet runway, it had climbed to a height of about 50 feet.
From this point, it was seen to climb steeply
until its attitude was almost vertical - with its
back towards the way it had come. It reached a
height of 500 to 600 feet when it suddenly
nosed down , the port wing dipped and the
machine plummeted to earth. It was unclear
whether the aircraft did a 'back-flip' or pitched
nose-down at the peak of its flight path.
One of the remarkable features of the crash
was the very confined area of the wreckage.
All crew and passengers were killed.
The court of inquiry found that the evidence
was inconclusive in determining the cause of
the crash but it found that the aircraft was
loaded beyond t he allowable aft CG limit for
this aircraft. The court also made the observation that improper dis tribution of the load
may render the aircraft at best more difficult to
handle and at worst highly dangerous.
. . . and beyond
The fully-loaded Lockheed Lodestar taxied for
take off.
There was apparently no prior run-up and the
aircraft accelerated for takeoff.
The ground run was quite short - indicating
that the engines were delivering full power.
After leaving the ground, the aircraft was
observed flying level, close to the ground
during which time the wheels retracted. It was
just as the retraction was completed that the
aircraft started to climb - but this climb soon
became abnormal in its steepness.
Some eyewitnesses gained the impression that
the aircraft would go over the vertical and they
estimated that it ultimately reached an attitude
of 80 to 85 degrees . A pilot who observed the
flight, estimated a more conservative 40 to 45
degrees.
The aircraft reached a height of 200 to 300 feet.
Why did I choose these part icular accidents?
For interest? Certainly. In one case perhaps for
a touch of humour. The important thing though
is t he 'message', the moral of t he story. I don't
need to remind pilots of the frequency of accidents involving a collis ion of some kind, either
with an animate object - as experienced by
our cadet friend - or an inanimate object.
Of these, the mid-air collision is especially
frightening. You will recall t he recent
'Sky dancers' accident and t he RAAF's
'Roulettes'. There have also been mid-airs in the
circuit area. Even one is too many.
The aft CG accidents are topical because of the
hidden danger of a ircraft loading - a danger
not realised until it's too late. A recent accident
in the United States brings this horrifyingly to
mind:
A Lockheed Lodestar was being used to carry
skydivers. The big lumbering transport was the
ideal platform for mass jumps where dozens of
jumpers could exit close together and link up.
The aircraft was designed to carry a nominal 10
to 14 passengers but with the seats removed
and with low fuel, it could carry 24 jumpers
and still stay within the all-up-weight limit.
However, the CG was another matter.
It was theoretically possible to carry a load of
24 parachutists and stay within the CG envelope. However, in practice the jumpers with
their bulky parachutes could not be arranged in
this way.
Nevertheless, the Lodestar regularly carried
this load - and it remained controllable.
To minimise the separation between jumpers, it
was usual to have a few hanging around the
outside of the door - indeed a special ledge
had been constructed for this purpose. The
remainder bunched inside. The pilot would slow
the aircraft to within 10 knots of the stall with
gear and flaps down and then throttle back the
left engine to minimise prop blast on the exiting
jumpers.
As the aircraft slowed down for the drop, the
parachutists moved back towards the door. The
pilot applied full nose-down trim and held the
y oke h ard forward - to hold the tail up
against the effect of the extreme aft CG
position.
(The CG was estimated to be some 16 inches
beyond the aft limit for the aircraft.)
The jumpers began to exit as the aircraft ran
out of elevator power. It pitched up, stalled ,
rolled inverted and entered a near vertical,
spiral dive . Three jumpers got out after the
spiral began. Two dragged themselves out
against heavy centrifugal forces and were
struck by the tailplane. A third was killed by
this impact. The remaining eight jumpers and
two pilots died in the aircraft .
It was later discovered that four other
instances had occurred, of spins or spirals in
these circumstances. In these cases the pilots
had been able to recover. (perhaps the jumpers
managed to exit and the aircraft again became
controllable.)
So that's a slice of history, both humorous and
tragic. All accidents have a message. Individually we must be r eceptive to these messages.
Above all oth ers, the message from our forebears is:
'Don't you make the
same mistakes that
killed us.'
�Aviation Safety Digest
138
Aviation Safety Digest
138
'see and avoid' the other aircraft due to th e
erroneous traffic advisory combined with
physiological limitations of human vision and
reaction time at night.
Look out
by Roger Marchant
One aspect, though, predominates. The Falcon
and all other aircraft were circuit traffic. Only
the PA28 was in overflight. But they were all
at 1500 ft agl! The Archer pilot knew there
were other aircraft; he knew they were in the
circuit. Could it be he assumed all circuit traffic
flew at 1000 ft. Did he really think he had a
certain 500 ft separation?
ATC
'I believed I
could clintb above
it'
It is interesting to consider the situation in Aus-
. N November 10 1985, in the vicinity of
Teterboro airport, New York, a PA28-181
...::.. Archer impacted the leading edge of the
port wing of a Falcon DA50 jet. The Archer was
t ransitting the airport traffic zone. The Falcon
was manoeuvering for a standard instrument
approach. Both aircraft were operating in VMC
at night, were at 1500 ft above t he field and
were under the control of Teterboro tower.
There were six other aircraft on frequency, and
the Falcon had been ordered to 'plan number
t hree following traffic turning downwind abeam
the tower'. The Falcon acknowledged this call
and thirty seconds later, advised the tower;
'traffic in sight' . In fact, he had acquired the
PA28, which, far from maneouvering for an
approach, w as merely crossing west to east.
The Falcon subsequently made a left turn outside the Archer in order to remain in the pattern, lost sight of the light aircraft, which was
maintaining its heading across the zone, until
eight seconds before impact, when the captain
shouted 'Hey watch. out, this guy's coming right
at us!'
Subsequent calculations established that a minimum of 12~ seconds would have been required
under the prevailing circumstances for t he Falcon crew to make a substantial change to aircraft heading/altitude. The weather conditions
were good, but it was 10 minutes past evening
civil twilight and t he accident took place above
a heavily populated, well lit area.
The National Transportation Safety Board
determined the cause of the accident to be a
combination of breakdown in ATC coordination,
whereby an overloaded tower controller passed
inaccurate advice, resulting in an air traffic
conflict, and the inability of the Faclon crew to
tralia. The IFR jet would be given positive separation by ATC, not merely 'traffic' on other
aircraft operating VMC. And, of course, everyone knows that circuit height is 1000 ft for pistons, 1500 ft for jets. Or do they? Or, more to
the point, is it? Well, let's assume most pilots
are of the opinion that those heights prevail for
the differing aircraft types. Nowhere in the Air
Navigation Act or the Regulations is it legis lated that there is a particular heig.ht above the
ground for 'circuit' flying. The only stipulations
are that the traffic pattern mu st be joined up,
cross or downwind and all turns be to the left
(even this is capable of variation by the Secretary). There are, however, many subsidiary
documents and publications - none of w hich
has legal status - to persuade you that 1000 ft
is correct. For example, the VFG at 61-2, 4.3.1
suggests t hat any other circuit altitude than
1000 ft above the ground requires an individual
clearance, and at 61-5 it quotes 'normal circuit
pattern' as being 1000 ft above aerodome
elevation.
More recently, in this very magazine, the
beautiful diagram titled 'How are your circuit
entries?' (ASD Summer 1985) specifies the same
1000 ft. In truth, t here is nothing legally to prevent you doing a circuit at 1200 ft, or even
down to 500 ft (where ANR 133(2) (b) steps in
to prevent low-flying). It is as well to know,
then, that should you be overflying an airfield
at 1500 ft agl, you may well be confronted with
somebody who is legitimately 'downwind'. This
goes double for jets, for 1500 ft is a more comfortable altitude for bigger/faster aircraft and
it normally coincides with final approach fix
altitude for practice instrument approaches.
Therefore operators, in their operations
manuals, stipulate 1500 ft for circuit flying.
But be w arned! These are n ot legal requirements. 1000 ft for pistons, 1500 ft for jets, like
Topsy, have 'just growed up' as convenient circuit h eights in Australia. So don't get caught.
Be aware of the possibilities of other aircraft
operating at your a ltitude. Give your eyes a
chance and make sure your undoubtedly excellent scan is backed up by an awareness of the
law and a knowledge of the consequent possibilities of confliction.
Above all, do not plan to operate in a circuit
where jet ope rations take place, at 1500 feet agl 0
From an earlier Digest
HE SINGULARITY of t his latest addition to
the 'Below VMC' accident list, lies in the
fact that it didn't h appen - at least not in
the way we normally expect. The traditional
type of ending was however , avoided only by
what must have been the narrowest of
markings and certainly n ot by any good management on the part of the pilot! Thus, as well
as providing another most valuable object
lesson on the danger s of unauthorised 'Below
VMC' operations, t he happy ending to this neardisaster exemplifies the value of requesting
assistance when in difficult ies, and gives some
idea of the help that is readily a nd freely
offered to pilots w ho are known to be in trouble.
At the time control was lost, t he light aircraft
involved was in the vicinity of Kilmore, en
route from Moorabbin to Canberra . Kilmore is
situated in a gap in t he Great Dividing Ra nge,
35 miles north-east of the city of Melbourne.
The story has been taken almost verbatim from
the actual record of communications between
the aircraft and Melbourne ATC, and t he pilot's
description of the flight which he gave after
landing at Melbourne Airport.
1125 AIRCRAFT Melbourne, this is Juliett Victor Mike on 118. 9.
ATC
This is Melbourne Departures. You 're not yet identified. Report present altitude.
1126 AIRCRAFT Present a ltitude 3000.
ATC
Climb t o 7000 VFR. Area
QNH 1005. Report at 7000.
Your route clearance is
Kilmore, direct Mangalore.
1129 ATC
Confirm you'r e just pass ing
Kilmore now.
AIRCRAFT Cannot see Kilmore. We're
not in VFR conditions. I'm
climbing to 4000 now and
going to 7000.
Confirm you're not in VFR
conditions or you j ust don't
have sight of the ground?
AIRCRAFT I don't have sight of the
ground.
ATC
Roger , but confirm you can
continue climb in VMC?
AJRCRAFT Well I'm going to keep going
jar a little longer to see how
I go.
ATC
Roger , advise if you can't
maintain VMC.
1133 ATC
Present altitude?
AIRCRAFT Just going through 6000.
ATC
Are you equipped with
130.4?
AIRCRAFT Standby.
1135 ATC
Still this frequency?
1136 (Aircr aft calls on 124 .7)
ATC
This is Melbourne Approach,
maintain VFR a nd report if
in VFR conditions
AIRCRAFT We are not VFR!
ATC
Roger, r eport your altitude.
AIRCRAFT Four and a half thousand.
1147 AIRCRAFT Juliett Victor Mike. We 're
having terrible difficulties at
the moment. We're not VFR
and we 're about four and a
half thousan d. I'm trying
hard to control the aircraft!
ATC
Roger , report w h en yo u are
clear of cloud. Are you able
to maintain a level attitude?
1138 ATC
Reply when read y. Ar e you
able to maintain a level
attitude?
1139 AIRCRAFT Just m anaged to regain level
attitud e. I'm having a h ell of
a job. But I'm at 5000 f eet
and I am in a level attitude
at the moment and I'm f allowing the ADF to
Mangalore.
ATC
Roger you 're clea red at 5000.
Maintain a level attit ude and
report when you are visual,
clear of cloud.
1140 ATC
Reply when convenient wit h
your fuel endurance .
AIRCRAFT We d eparted Moorabbin with
310 minutes endurance.
1142 ATC
Your flight conditions at the
moment?
AIRCRAFT I s till cannot see the ground
and I'm flyin g straight and
level. I've got the ADF needle
heading for Mangalore and I
can see the sun a bove me but
that's all.
�Aviation Safety Digest
138
ATC
1143 AIRCRAFT
ATC
AIRCRAFT
1147 ATC
ATC
1149 AIRCRAFT
ATC
AIRCRAFT
1150 ATC
AIRCRAFT
A TC
AIRCRAFT
Roger. If you can climb
safely, suggest you initiate a
climb to get on top of cloud
and this will also improve
our radar response on your
aircraft.
Am climbing now from 6000
through 7000 ... my present
heading is 360 with the ADF
needle pointing to 0. I might
help you to pinpoint my
position.
We h ave you identified at 10
miles SSE of Mangalore.
Report your flight conditions
now.
I'm climbing through seven
and a half and I can't see the
ground. I'm still not above
cloud... do you suggest I continue to climb?
We've been advised t he cloud
tops are at 10 OOO feet so if
you ' d like to level out we'll
initiate a turn r ight, on to a
heading of 2 10. Make a very
gradual turn and report
when established on 210.
Your position is 35 miles
NNE of Melbourne. You can
either maintain 7000 or you
can continue to climb to try
to get on top of this cloud.
Advise.
I'm even on 7000. My present
heading is 175 and I'm
endeavoring to steer to 210.
I'll continue to plot you on
radar. The main thing is to
maintain a level attitude.
Am continuing to climb. Am
now at 7200. It's just
starting to clear a little in
front of us... we've broken
through the cloud and we
can see holes in it down
below us!
Roger. Do you think you can
maintain a clearance from
cloud in your present position or w ill you be going
back into cloud?
I'm going back into cloud. I
can just see the ground.
There's a little farmhouse
below us.
Sugges t you continue to
maintain a level attitude and
if you're able, position yourself clear of all cloud.
Could you suggest at the
moment a heading to try and
keep on track?
Aviation Safety Digest
138
Your heading is good to
Essendon or Melbourne. If
you like you could turn right
on to a heading of 210.
AIRCRAFT Is the weather in Melbourne
visual?
ATC
Affirmative. There are
reported gaps in the cloud
between you and Melbourne.
AIRCRAFT I'd like to turn back to Melbourne if you'd gi,ve me the
guidance.
ATC
Roger, I'll continue to plot
you on radar. You can expect
gu idance to Melbourne but
the main t hing is to maintain
a level attitu de at this time.
AIRCRAFT Am heading now 215.
115 1 ATC
1153 ATC
Your heading is good for
Melbourne.
1154 AIRCRAFT I have located Essendon NDB
on 35 6 and am now following the n eedle.
ATC
Roger . Maintain a level
attitude .
1155 AIRCRAFT Melbourne, I've now broken
through and can see blue sky
in front and a break in different cloud formations.
ATC
Roger. Advise when you are
fully VFR on top of t his
cloud.
1156 AIRCRAFT Melbourne, this is Juliett
Vi ctor Mike,. Now that I'm
out of the cloud, I've just
noticed that the aeroplane
has suffered structural damage on the wings due to the
forces encountered whilst we
were out of control.
ATC
Roger. Maintain VFR on top
and advise the extent of this
structural damage also your
indicated airspeed.
AIRCRAFT I'm now fa the open away
from cloud and can see the
ground clearly. The structural damage is that the
wings have bent just outward
of the tanks on both sides
where the wing joins. It's
approximately five f eet from
the wing roots on both sides.
ATC
Could I h ave your indicated
airspeed?
AIRCRAFT Indicated airspeed is 96
knots.
1157 ATC
Roger. Are you able to
descend from your present
position Lo 4000 feet maintaining VFR?
AIRCRAFT It is possible. It's quite clear
beneath me now. Descending
from 7000 through to 4000.
ATC
Report approaching 4000.
1159 ATC
Could you advise if your
wings are bent up or down?
AIRCRAFT Both 'Wings are bent
upwards.
At this stage, the flight was vectored west of
Melbourne Airport while the air traffic controller working the aircraft telephoned Moorabbin
Airport to confer with a highly experienced flying instructor who was thoroughly familiar
with the aircraft t ype. They discussed the possible effect of the wing damage on the handling
of the aircraft during the approach to land, part icularly in relation to the strong crosswind
components which prevailed on both runways
at Melbourne Airport. As it seemed desirable
that, in its damaged condition, the aircraft
should be landed into wind, the question of it
returning to Moorabbin was considered.
Before any decision w as made however, t he
pilot was requested to check the aircraft's
handling characteristics at a safe height by
slowing to about 10 knots above stalling speed.
He was warned while doing so to leave t he
flaps up and to restrict the angles of bank to no
more than 20 degrees. A few minutes later the
pilot reported that the aircraft's characteristics
seemed normal but he had not wished to 'push'
the tests too far as the wings had begun to 'flap
a bit' as the aircraft approached the stall.
The pilot was then advised that his approach
speed should be maintained at 80 knots , 10
knots above normal, to make allowance for this
fact. It also was decided that it would be
unwise to take the aircraft back over the suburban built-up areas to Moorabbin Airport in its
damaged condition. Instead, a grassed area
between the runways at Melbourne Airport,
where the aircraft would be able to make a
landing into wind if the pilot so desired, was
prepared. Fire tenders were brought into position and after the aircraft had been vectored
over the airport and detailed instructions had
been passed to the pilot, he was told that the
airspace was 'all his' and that he was cleared to
land anytime he wished. The aircraft
subsequently made a safe crosswind landing on
the runway.
Describing his experiences afterwards, the
somewhat shaken private pilot said:
We departed Moorabbin a t 1051 and I tracked
to Yan Yean via Nunawading at 2000 feet without any problems although I was not familiar
with the area. From Yan Yean we tracked to
Kilmore and visibility to Kilmore was quite
good. We could see the ground at Kilmore
although there were patches of cloud in the
area. I gave a position report at Kilmore at
1122 at 3000 and I was going to commence my
climb from there. From there on I d id not keep
a log but at about 1135 I was aware that it had
become misty and I asked for a clearance to
7000 feet because I could see the sun above us
and believed that we could get above the cloud
and into the sunlight.
The clearance came back to climb to 7000 feet
and I immediately initiated the climb to seven
thousand. It was during this climb that Melbourne asked if I had 130.4. Not having used
this frequency before I was not sure that I had
it or not. I tried to select this frequency and
this is where the trouble started. I took my eyes
from flying the aircraft and it was then that I
lost my flying attitude. When I had finished fiddling with the radio selector I noticed that the
flight attitude indicator had toppled. Then I
tried to get back to the original frequency but I
could not remember what it was. Eventually I
managed to contact Essendon, who advised me
the correct frequency. This is where I lost control of the aircraft completely and my wife had
the presence of mind to select the Melb01trne
Approach frequency and I asked her to advise
them that we were in difficulties.
From then on we were going up and down, in a
spiral dive and I think that the aircraft
descended from 6000 feet to about 2000 feet
because I saw the ground at one stage - very
close. But I managed to get in to a climb and
the altimeter indicated the climbs and
descents. The airspeed indicator was fluctuating from 0 to 140 and 160 knots. Eventually I
got the aircraft approximately stabilised and
managed to keep it on an even keel. From there
on Melbourne asked me to let them know when
I was straiqht and level, which I did. They then
advised that they had me on radar and
vectored me to Tullamarine. When we broke
clear of cloud, I could see that the wings had
suffered structural damage and during the
descent we picked up some rime ice. We were
given different headings to fly and when we
could see the ground we were asked to descend.
We eventually landed at Tullamarine.
The pilot, who needless to say, had no instrument flying experience, added that when he
commenced his climb to 7000 feet at Kilmore
he believed he could climb above the cloud '
ahead. The cloud increased as the aircraft
climbed but t he pilot thought this would be
temporary only. He had considered turning
back but, because he could still see the sunlight,
he continued ... D
�Aviation Safety Digest
138
Aviation Safety Digest
138
Trial and error
From Lilienthal to Ligeti
N THE course of aeronautical progress many
sacrifices have been made. The early pioneers
certainly had to learn the hard way but today
with such a wealth of aeronautical knowledge,
is this loss of life inevitable?
I don't believe so. There are experts in most
fields and flight testing is no exception. A flight
test program is carefully planned and conducted to minimise risk and to maximise data gath.ering. No-one wants to lose the valuable
aircraft or the expensive-to-train, test pilot. It
is doubly important where the pilot is also the
designer of the aircraft.
A flight test program is exploratory by nature
and the golden rule is to always start from a
known safe point and explore the envelope
carefully from that point. There are many ways
to identify that point using computer prediction, models, wind tunnel tests and modification
to proven configurations.
To go straight to the first flight without such
prediction is increasing the risk significantly.
There is enough risk and loss of aircraft in professionally conducted programs - the risk in
non-professional programs is potentially much
greater.
Also tests arc planned with a way out - an
escape route for the pilot - perhaps a parachute, ejection seat, anti-spin chute and above
all tests are conducted at a safe altitude - an
altitude such that if things turn to worms the
pilot has time and space to attempt some novel
recovery methods and still have time to get out.
In recent years the design of ultralight aircraft
has emulated those early pioneering days the new dawn of aviation. But why do we not
learn from the past? There is a wealth of data
available. It seems crazy to make all the same
mistakes and accept further unnecessary loss of
life.
Historically there are many incidents. Overseas,
famous pioneers such as Lilienthal, Wright, de
Havilland were lost in exploratory or demonstration flights. There were several in Australia. Here are a couple from the archives:
Oct 1921
Rainbow VIC Experimental machine
Struck tree in taking-off on trial flight. Pilot
not licensed.
Sep 1930
Mascot NSW
DH-71 Tiger Moth
Test flight in experimental machine. First flight
by pilot. Take off normal. When travelling at
high speed at 1000 feet, the machine dived,
then rose and the pilot fell from the machine.
Pilot had not affixed safety belt before leaving
ground. Pilot used controls coarsely through
inexperience causing machine to hunt during
which he was thrown from his seat. Fatal.
Aug 1937
Fishermen's
Experimental
Bend VIC
Monoplane
Starboard wing crumpled and broke off at end
of power dive and although the pilot
straightened the machine out and attempted a
pancake landing, it became uncontrollable and
crashed. Fatal.
March 1985
Similarly, more recent flight test accidents have
aspects that are cause for concern:
March 1984
Kingaroy Qld
Bryan HP18
The glider was undergoing its second test flight
since construction had been completed. After
the test sequence had been completed satisfactorily, the pilot positioned the aircraft for landing. When the aircraft was about 150 feet agl
the pilot reported by radio 'something broke'. It
was observed to enter a steep spiral descent
which continued until ground impact.
The glider had been built by the owner from a
kit of parts which had included the fuselage for
one glider type and the wings of a different
type. This anomaly was not detected until the
wings were being fitted to the fuselage. The aircraft kit manufacturer then advised the builder
on ways to overcome the problem. The builder
had carried out the modifications but found
that the flap drivers did not fit correctly into
the flap ends. Plates were then added to the
flap drivers to provide more engagement with
~he flap ends.
Following the first test flight, the pilot, an
approved sailplane engineer, undertook to carry
out work on the aircraft to correct various
faults discovered during the flight. These faults
included problems with the flap actuating
mechanism. The alterations were carried out
with the wings removed from the aircraft.
When the aircraft was assembled prior to the
second test flight, the pilot apparently failed to
notice during his inspection, that the flap
drivers were not adequately engaged in the flap
ends. During the approach to land, the left
hand flap driver had become disengaged and
the flap retracted. The resulting asymmetric
flap condition led to loss of control of the aircraft.
Nagambie Vic.
Veenstra Rustler
The owner/ pilot had been designing and building ultralight aircraft for a number of years.
This particular aircraft had been designed for a
noscwheel landing gear system. However, after
flying the aircraft, the pilot decided that he did
not like this particular configuration. He had
decided to modify the aircraft to a tailwheel
design and had spent a considerable time over
the preceding weeks on the rebuilding program.
After completing the work, the pilot was forced
to wait for several days for suitable weather
conditions in which to carry out the first flight.
On the morning of the accident, the pilot carried out a pre- flight inspection before taxying
to the end of the strip. He was observed to
exercise the controls prior to commencing the
take-off. The aircraft became airborne after a
ground run of about 125 metres, and the angle
of climb was seen to progressively increase. At
a height of about 80 feet above the ground the
left wing dropped and the aircraft dived steeply
to the ground.
An inspection of the wreckage revealed that the
ailerons had been incorrectly rigged and were
operating in the reverse sense. It was considered possible that the pilot may have been
momentarily confused when the aileron
response was not as expected, and may not
have noticed the steepening nose attitude in
time to take corrective measures. In this design,
he pilot sat in a totally exposed position at the
front of the aircraft, and had only limited pitch
attitude references. The pilot had not flown a
totally open cockpit aircraft for some considerable time and was not wearing goggles. Apart
from the aileron problem, no other faults were
found during the investigation.
October 1985
Bankstown NSW
Quickie Q200
The aircraft was being flown for the first time.
The pilot stated that after take-off, the aircraft
felt very nose heavy and that he had difficulty
in maintaining a nose-up attitude. When he
attempted to reset the elevator trim, the friction nut broke. The back pressure that he was
required to hold, reduced as the airspeed
increased. During the subsequent approach, the
pilot found he had insufficient elevator control
to flare the aircraft. On touchdown, the aircraft
bounced and a go-around was carried out. The
pilot made several other landing attempts but
on each occasion, the aircraft bounced. On the
final attempt, the aircraft bounced a number of
times before the right canard collapsed and the
aircraft ran off the runway.
The aircraft had been correctly loaded, with the
centre of gravity 14% aft of the forward limit.
However, the rigger's angles of incidence on the
wing and the canard were found to be 0.3
degrees outside the design specifications. It was
apparent that there was a critical relationship
between these angles, the centre of gravity position and the amount of pitch control available.
�Aviation Safety Digest
138
Aviation Safety Digest
138
July 1986
Toogoolawah Qld
Unnamed
Prototype
Initial test flying of the aircraft had been commenced the previous day. The pilot, who was a
friend of the owner, had carried out a number
of short hops along the 1000 metre strip. The
following morning, a further six hops were carried out, after which the pilot announced his
intention to conduct a right hand circuit and
landing. He made one further short flight along
the strip, before taking off for the circuit. The
aircraft passed over observers on the ground at
a height of about 300 feet, before passing out
of sight. Shortly afterwards the noise level of
the engine changed several times before ceasing
a ltogether. A nearby farmer saw the aircraft in
a left turn when the engine stopped. The turn
tightened and the aircraft disappeared behind a
hill. Sounds of impact were then heard.
Investigation revealed that the aircraft had
struck the ground while in a left spiral and
travelling at relatively high speed. The engine
was not rotating at the time of impact but no
evidence could be found to suggest that it was
not capable of operation. The fabric on the left
wing showed signs that it had separated along
the entire trailing edge in flight.
September 1987
Deeral Qld
Wheeler Scout
Previously the aircraft had to be flown with
the control stick displaced to the right of centre
in order to maintain a wings-level attitude. The
aircraft owner advised a visiting ultralight pilot
of the problem, who offered to attempt rectification. After conducting a flight to experience
the problem first hand, this pilot adjusted the
right wing warping wire and conducted another
test flight.
The adjustment had improved the trim problem
but had still not completely provided a fix. The
pilot then readjusted the right wing warping
wire to its original condition and added a
D-shackle to the left wing warping wire, to
increase its length. Another test flight was carried out and it was found that the aircraft
could only be maintained in level flight with
full right rudder and full right control stick
applied. Unfortunately the aircraft was then
struck by a wind gust and the left wing
dropped. As no further control was available to
correct this situation, the pilot grabbed a wing
warping wire. As luck would have it he pulled
the right wire instead of the left wire and was
unable to correct his error before the aircraft
struck the ground.
A subsequent inspection of the wreckage found
that the right wing warping wire was 19 millimetres longer than the left. Also, all the dimensions of the right wing were slightly larger than
that of the left wing, resulting in the right wing
area being about 80 square ccntime~res greater.
September 1987
Penfield Vic.
Ligeti Stratos
This aircraft was intended to be the production
version of the 'Stratos' aircraft. The prototype
version had successfully flown some 340 hours.
The production model incorporated significant
changes made by the designer/ pilot. These
changes included the removal of the dihedral
from the main wing, the use of full span elevators on the canard wing and full span ailerons
on the main wing. The engine mounting was
lowered such that the ducted propeller was
totally below the main wing and the lower part
of the propeller duct was extended well for'Nard to form a 'channel wing' or strake.
The main purpose or the channel wing was an
attempt by the designer to lower the stall speed
of the aircraft and to consequently reduce both
landing and takeoff speeds and distances. As
far as the investigation could determine, the
effect of these modifications had not been
checked by wind tunnel or other methods prior
to this flight.
On the day of the accident, the pilot and his
assistants had worked at the factory preparing
the aircraft for testing. The preparation
included a determination of the CG position,
although no record was kept of these calculations. The aircraft was taxied up and down
the runway five times and during these taxy
tests, the control column position was adjusted.
On the next run, the aircraft became airborne
and flight was continued in the local area for
about 17 minutes before the aircraft carried out
a 'very slow ' run over the airfield at an altitude
of between 400 and 500 feet agl. The aircraft
then flew for about a kilometre before turning
and heading towards the airfield. Several witnesses reported that, shortly after the turn, the
aircraft went out of control. The description of
the type of manoeuvre performed by the aircraft at this time, varied from the nose of the
aircraft going up and over the tail, to the nose
abruptly falling through the vertical. All the
witnesses agreed that the aircraft then fell vertically while the nose swung in a pendulous
motion. The aircraft impacted rocky ground in
an inverted attitude with little or no horizontal
speed.
An inspection of the aircraft found that all
airframe components were essentially intact
and there was no indication of any airframe or
control failure prior to ground impact . The
engine was test run and strip inspected and no
fault could be found.
No aerodynamic testing was carried out on the
airframe to determine the likel y effect on performance of the various modifications made to
this aircraft. However, given that the prototype
appeared to suffer no adverse flying characteristics, it is possible that the modifications incorporated in the new aircraft had an adverse
effect on the stall characteristics.
The names of today's pioneers may one day
become household words just as the early pioneers were household names in their day - the
Veenstra's and Ligeti's of today are no different
from the Lilienthal's and Wright's of
yesteryear. But let's learn from the past and
keep future pioneers alive a little longer. Please
use professionals for flight test programs. Little
aeroplanes can push the frontiers of technology
just as much as the multi-million dollar j ets and they can kill you just as dead 0
�Aviation Safety Digest
138
Aviation Safety Digest
138
But for a moment, let's turn back Lhe clock:
The tinies they
are a' changing
- or are they?
Mar 1921
Avro
Pithara WA
Doubt as to cause but suspicion of interference
by passengers with pilot. Fatal.
Apr 1921
Maryborough
Avro
Water in petrol caused forced landing. Machine
struck rough ground.
May 1921
Port Melbourne
Avro
Passenger's heel jammed controls. Fatal.
Nov 1921
Sale
Boulton
Paul
Passenger interfered with joystick. Write-off.
DH-6
Dec 1921
Canterbury
Flying dangerously. Licence suspended for 6
months.
Bristol
Dec 1921
Gerald ton
Error of judgement. Banked too steeply when
landing in rough country. Fatal.
Feb 1922
FE-2B
Boulder
Engine trouble. Struck post w hile trying to
land.
Nov 1922
Service ton
Boulton
Paul
Struck car when taking off. Ground used was
too small.
Short
Dec 1922
Sydney Harbour
Machine canted to one side a fter rising from
water, fell back and sank.
Dec 1922
DH-6
Cronulla
Faulty ignit ion. Sparking plug failed. Gross negligence on part of engineers. Machine's licence
cancelled. Pilot inj ured.
HEN YOU look back over the years it
seems at first s ight t hat we are ma king
t he same mistakes and having t he same
accidents as our forebears . It is so consistent
t hat it is predictable.
In the coming years t here will probably be some
of each of th e following:
• stall/spin, loss of con tr ol
• takeoff, unable to climb
• engine failure, turn-back
• landing accidents
• loss of control in clou d
• wire strike
• maintenance fault
• collisions with variou s objects - animate and
inanimate, and
• perhaps a mid-air collis ion or two.
Bristol
Tourer
Error of judgement of pilot. Hit fence while
taking off. Passenger killed.
Jan 1923
Hedland
DH-4
Gilford Park
J u n 1923
Struck unforeseen telegraph wire when landing.
Badly damaged.
Oct 1924
Cunningham
DH-9
Encountered thunderstorm. Aircraft damaged
during precautionary landing.
, DH-6
Apr 1925
Orange
Pilot suffered from weak heart. Pilot unlicensed
and medically unfit. Machine without C of A.
Fatal.
Sep 1925
Caloundra
Avro
Machine damaged on landing. Encountered loose
sand.
Oct 1925
Moss Vale
DH-6
Engine giv ing insufficient revs for takeoff possibly due to inferior benzine.
Jan 1927
Wallacedale
Avro
Struck stump when taking off. Then struck
fence and overturned. Machine badly damaged.
Jan 1927
Longreach
DHMoth
Flying school pupil doing first solo. Report indicates that pupil got air bump, lost his nerve
and control over machine which crashed with
engine on.
Feb 1927
Ripley
Avro
Engine stopped at comparatively low altitude
when petrol from one of the two grav ity ta nks
was exhausted. Petrol from the other tank took
some time to reach carburettor and before
doing so, the pilot turned off the cock, possibly
to avoid risk of fire.
Jul 1924
Cloncurry
DH-9C
When taking off pilot experienced engine
trouble. Blockage in petrol system. Forced
landing.
Feb 1927
Mackinlay
DH-50A
Attempting to take off on very soft ground
after heavy rain. Collided with fence. Badly
damaged.
Mar 1927
Essendon
DH Moth
Pupil made bad landing, switched engine on
again but couldn't pick up quickly. Struck Anec
aircraft which was on the 'drome.
Mar 1927
Mascot
DH-9C
Result of bad approach which was followed by
stalling of the machine. Fatal.
Dec 1923
Longreach
Bristol
Loss of height quicker than expected. P ilot h it
ground wit h nose of machine in endeavour to
clear a fence.
Jun 1927
Brisbane
Pupil made 'pancake' landing.
J ui 1924
Hcdland
Bristol
When turning at heigh t of about 400 feet,
machine suddenly nose-dived into sea. Cause
not determined . Passenger apparently drowned.
Jul 1927
Perth
DHMoth
Pupil doing fourth solo flight. Machine 30 feet
from ground came in contact with tramway
cables and ignited. Fatal.
DHMoth
�Aviation Safety Digest
138
Aug 1927
Essendon
DH Moth
Rudder control jammed following steep right
hand turn when about to land. Jamming probably caused by passenger's feet.
Aug 1927
Mascot
DH-50
Struck by propeller. Failed to get out of the
way of the machine which was taxying after
landing. Fatal.
Mar 1928
Parafield
DHMoth
Carrying out aerobatics at too low an altitude.
Fatal.
Mount Lofty
Sep 1928
DH-50
Owing to compass being located in Ranges
unsuitable position, pilot experienced difficulty
in maintaining straight course while flying in
thick clouds. Machine got out of control. Mechanic killed, pilot injured.
Sep 1928
Coonabarabran
DH Moth
While taking off the machine suddenly lost
height and the undercarriage failed to clear
trees. Subsequently destroyed by fire caused by
cigarette.
Aug 1928
St Peters
Curtis
Tail spin - machine got out of control at 2000
feet - pilot did not regain control. Pilot not
s eriously injured .
Nov 1928
Essendon
DH Moth
Error of judgement. Pilot believed passenger
pilot had taken over and r elinquished control.
Machine flew uncontrolled for some time and
struck fence at 85 mph.
Dec 1928
Wagga
Widgeon
Restricted takeoff (buildings opposite runway)
caused pilot to stall when climbing - and spin
developed. First time pilot h ad tried to
manoeuvre machine out of this park.
DHMoth
Feb 1929
Mascot
Pilot put machine into controlled stall at about
1500 feet and when at an altitude of about 200
feet, lost control, the stall developing into a
right hand spin from which he did not recover.
Weather conditions bad owing to low lying
clouds - visibility very bad.
Jul 1929
Blue Mountains
DH Moth
Lost in fog. Struck tree when attempting to
land. Fatal.
Oct 1929
Baandoe
DHMoth
When flying at low altitude in the East-West air
race, struck a tree which pilot did not see, in a
fallowed field.
Aviation Safety Digest
138
Oct 1929
Ardrossan
DH Moth
Engine stalled at 800 feet. Due to a spin following an aerobatic manoeuvre. Fatal.
Widgeon
Nov 1929
Grenfell
Destroyed following structural failure of the
wing in flight. Fatal.
DHMoth
Mar 1930
Inverell
When taking off machine struck a cow hidden
in long thistles.
Jun 1930
Smeaton
Avro
In endeavour to gain s ufficient height to clear
trees in line of flight, pilot stalled the machine
at low altitude and had insufficient height to
recover from resulting nose-dive before striking
ground. Fatal.
Brighton-le-Sands
DHMoth
Aug 1930
Failure to recover from inverted spin d ue to
either stalling on the top of a loop or from a
steep turn at a height of a pproximately 2500
feet, the pilot being thrown clear of the
machine at 1000 feet. Fatal.
Aug 1930
Brisbane
DH Moth
Pilot flying at a dangerously low altitude. In
flying low and doing a left hand turn a round
the bows of HMAS Albatross, the aircraft
touched the water causing it to crash.
We could go on for years. The significant points
are the similarit y of the types of accidents to
today's operations. Technology has provided
more reliable machines. Airfields are genera lly
better. Air traffic services, communications and
Met services are better. Instruments and
avionics are much improved - as is our understanding of the strength s and weaknesses of the
human in the scheme of things.
And yet, when I look through the list of accidents, I can find recent cases of almost exact
circumstances. Does that mean that we haven't
learnt from the past? I hope not. It would be a
pity for all of those aviation pioneers to have
died in vain. It is an essential requirement for
progress, that we learn from our cumulative
experiences and adapt our behaviour accordingly. Most pilots are doing just that. Some
choose to go their own way. Some of the less
experienced pilots may not have had the
exposure to information that is available to
help them survive in the unforgiving aviation
environment.
It's up to each and every one of us to communicate and contribute to the bank of aviation
knowledge.
Our future depends on our learning from the
past D
Dear Sir,
As I am sure you know by experience, readers
are ever ready to write in and blast the editor
for some small conceived error, yet give no
praise for anything learnt from the articles in
the magazine. In this letter I am one of these narks.
On page 21 of ASD134 under heading 'The
in-flight cure' there is a statement: 'It is difficult if not impossible to close a door in flight'.
During the mid-1970 's I took out a P28 140
Cherokee on a weekday for a solo stooge from
Bankstown over Katoomba and return. This
was an RAC aircraft just out from a 100hourly. At about 500 ft after takeoff, the top
catch of door sprung open and door warped
enough to let in a lot of fresh air and noise. I
informed the Tower, completed the circuit and
landed, thinking I had not properly closed and
latched the door.
During checks prior to takeoff, I t humped the
door to see if it was properly locked and it certainly was firmly shut. About Springwood, I
dropped a wing to have a look at some traffic
on the highway. Again the door came open at
the top with all the accompanying noise and
concern as to whether the centre latch would
hold. On reaching Katoomba, I headed over to
the strip at Blackheath and at about 1500 ft
agl, pulled off the power, set the aircraft into a
slow glide, reached over and fully opened the
door and slammed it shut, locking it in place. It
remained closed for about ten minutes until hitting turbulence, when the top again opened.
No difficulty was experienced on landing.
Therefore, I disagree - having had practical
experience, with the statement quoted above.
(Name and address supplied).
Thanks .for your comments. Despite your experience I would be re!uctanl to play around wilh the
door in flighl. A recent accident we// i//ustrates my
concerns:
The pilot was carrying out a callle-spotting jlighl
before his colleague started the muster. After
initially setting-up a circuit pattern at 650 feet ag/
- due to turbulence at lower levels - he lowered
20 degrees of.flap and maintained 65 knots.
When the mustering aircraft arrived, he tightened
the pattern lo slay on his side o.f lhe road and a.fl er
lhe olher aircraft moved off. he retracted the flaps
and descended lo 500 .feet agl lo see if any animals
had been missed. As the aircraft was levelled, it
encountered a severe updraught followed by severe
downdraught and turbulence. The aircraft was still
descending when the pilot's door became unlatched.
The pi fol applied fit!/ power and lowered 10 degrees
offlap as the airspeed was fluctuating between 55
and 65 knols. While he was al/empting to close the
door. he noticed that the airspeed was reducing and
the aircraft was continuing to sink. He abandoned
the auempts to latch the door when the bt([feting
and the sink rate increased. Height was now down
to 250 feet and the airspeed was fluctuating
between 40 and 50 knots.
The pilot realised the seriousness o.f the situation
and lowered the nose and lowered another 10
degrees of.flap. He decided lo turn LO avoid the turbulence and to head into wind to regain lost airspeed. As he entered the turn and started to lower
more flap, heavier bi([fet was experienced and the
right wing dropped. The aircraft stalled and started
to spin.
He tried to recover from the spin by applying full
le.ft rudder and centralising lhe controls - followed
by s/ighl forward pressure. There was no immediate
response and because of the limited altitude, the
pilot tried to 'rock' the aircraft out of the spin by
shoving the controls forward and back and by
applying and reducing power accordingly.
�Aviation Safety Digest
Aviation Safety Digest
138
H e then returned to normal anti-spin control with
forward pressure on the controls and the aircraft
began to respond and the right wing started to
come up.
However, by this stage the pilot felt that impact
was inevitable and to avoid the risk offire, he
pulled the power of],' cut the master switch and
pulled the mixture control. He was in the process of
turning off the ji1el cock when the aircraft struck
the ground right wing first. The pilot recalls his
face im pacting the instrument panel and some time
later realising he was still in the aircraft with severe facial cuts and bruises and a broken collar
bone. He managed to scramble clear of the wreckage which did not catch fire.
The pilot assessed the conditions as far more severe
than anything he had previously experienced in
that region - this was in the Pilbara region during
the hot summer months and willy-wil!ys were
common.
I have described this accident in some deta il
because the pilot was able to provide us with a
fa irly good record of the events leading up to what
could well have been a fatal accident - in which
case we wouldn't even have detected or considered
the popped-door. It may not have been significant
but sim i/arty, it's j ust the sort of minor distraction
that can mean the difference between a safe arrival
and an accident.
Dear Sir,
In ASD 136 there is a very readable and
informative article by John Edwards - 'A
meas ure of success' on 'h appy and accurate
la ndings '.
At the top right of page 18 there is a table of
VSis for a 3 degrees glideslope and the figures
given are OK. Next comes a formula for use for
any slope which translates as:
'Sink rate (ft/min) = glideslope degrees
X GSkts X 100.'
Let's take for example the Ba ndierante with an
ILS spee d of 120 kts:
Sink rate = 3 degrees X 120 kts X 100
= 36 OOO ft / min (!!!)
Whew! This looks more like t he terminal velocity of an ICBM tha n a sedate approach to the
touchdown zone.
I think that if you check with John, h e will
agree that there is a bit missing out of the formula, namely the radian measure of 1 degree
which is 0.0175 because:
- 36 OOO X 0.0175 = - 630 ft/ min.
138
This is close enough to Lhe accurate result from
a complete trig. calculation which gives
-636 fpm.
The '100' in the formula is a substitute for
101.27 fL/min, which is 1 kt (based on
1852 m = 6076 fL per nm) wh ich must be good
enough for practical purposes in the cockpiL.
As they are constants in the formula the 100
and 0.0175 can be combined multiplied to give a
factor of 1.75.
So now our example becomes:
VS = 3 degrees X 120 kt X 1.75 = -630 ft/min.
This agrees with the result obtained from the
second formula using the slope percentage.
Because of the use of 100 instead of 101.27 in
both these for mula, the results are under-stated
by a shade over 1% and keen types <:an mentally add 1%, in the example above it would be
630 + 6 = 636. Alternatively they may choose to
use 1.77 as the factor and get a similar result.
I can think of a number of people down here
(and up there) who would regard this as pedantic quibbling, and I'll agree with any body
who says that it is easier when flying w ith one
hand, a nd thumbing around a circular slide-rule
(or the 'prayer wheel' on the back of Dalton) to
find the bigger graduation for 1.75 with the other.
As soon as I discovered this 'gremlin' my first
response was to ring my 8000 hr, 4 ring Check
Captain friend and ask him:
'Greg, do I or don 't I write to David Robson, he
may have already received a couple of dozen
letters about this?'
'There may have been a number of people who
have found the problem but haven't bothered to
write, and very few will have taken the time
and effort to find out what went wrong. It's
you r duty to write.'
So, David, here it is.
Captain L Buckworth
Dear Len,
Thank you for your comment. If you look
closely at John's formula you will see that it
includes ground speed - not in knots but in
miles per minute. Hence for your 3 degree/120
knot approach, the approximate rate of descent
would be:
3 degrees X 2 (miles per minute) X 100
= 600 fee t per minute.
Obviously this meth od is not as accurate as
your use of radian measure but as a guide, it
serves the purpose fairly well and is easier to
'compute'.
And to all of you experienced Captains out
there, p lease take the advice of the 'four-ringer'
and write. As he said, 'It's your duty!'
Dear Mr Robson,
ASD 136 - A Measure of Success
Judging a three degree glideslope or setting up
the correct rate of descent on a localiser or
locator approach with a groundspeed which
may reduce from 200 to 120 knots can require
some mental gymnastics if the 5 X G/S rule is
used.
We on the B767 at Ansett simply divide the
ground speed by two, add a zero and call it rate
of descent.
1 0
180 kt G/S = : = 90 plus a zero= 900 fpm rate
of descent
Yours sincerely,
Graham Thomas (Captain)
Thanks Graham. Dividing by 2 and adding a
zero is of course mathematically the same as
multiplying by five - but I agree that it is an
easier way of doing it.
There are several such 'rules-of-thumb' in aviation and if readers have any similar mental
tricks, I would be keen to see them shared via
the Digest.
Dear Sir,
In your article 'Gone with the wind', you
omitted one significant point regarding selection
of a strip in crosswind conditions. The torque
and gyroscopic effects all operate in the same
direction. It's a sensible precaution in a situation where the wind is directly across the
strip, to choose a takeoff direction where the
crosswind counters the other effects, rather
than adds to the problem.
If the aircraft normally swings left on takeoff
then a crosswind from the right can actually be
favorable.
Regards,
Doug Ryan
Good thinking Doug -
and good planning.
�
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1988
-
https://collections.heritageoftheair.org.au/files/original/94c9ebc01407177246443b18512b6404
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----~~--------------------~ ---·
- --
ASK YOURSELF :
eAm I sure I can achieve my planned
threshold speed ?
eAm I sure I can achieve my planned
touchdown point ?
e Am I sure I can cope with
the conditions?
\
- ~
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.
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�Aviation Safety Digest is prepared by the
Flight Standards Division and is published by
the Australian Government Publishing Service.
It is distributed to Australian licence holders
(except student pilots), registered aircraft
owners and certain other persons and organisations having an operational interest in safety
within the Australian civil aviation environment.
Contents
4
Undercarriage -
Editorial
oops!
lnadvertencies.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Department of Transport and Communications
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone (062) 95 4411 . Telex M62013
5
Winter 1988
W
Armchair theatre
The pause that refreshes.
6
The maintenance release crew aspects
flight
What we always wanted to know but were afraid to
ask.
8
Airframe icing
Lumps of another dimension.
10
Satellite pictures
What does it all mean?
Subscriptions may a/so be lodged at
Commonwealth Government Bookshops in
the capital cities.
12
Mountain wave activity and its effect
on aviation
The ups and downs of mountain flying.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Division. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
13
Visual detection of mountain waves
What to look for.
14
The new area forecast
Good stuff in plain language.
Unless otherwise noted, articles in this
publication are based on Australian
accidents. incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safely.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safely Digest
Flight Standards Division
G.P.0 . Box 367,
Canberra, A C. T. 2601, AUSTRALIA
inter is upon us - in fact it has been for some time. This
issue includes the first of a series of articles kindly
_
con tributed by the Bureau of Meteorology on weather and its
sig nificant effect on flying. The articles will correspond to the
seasons and will appear in each issue of the Digest over the next
year. While they are not intended as a course in Met, I hope that
they will serve to remind us of the more important aspects of the
Australian cl imate and the effects of local weather.
In the other Australian aviation environment, the operational one, a
significant change is taking place - with the formation of the Civil
Aviation Authority. While it may appear to be a rad ical step, it is
intended to make the operC:).tional side of the previous Department a
more efticient and more responsive organisation and in the process,
to enhance standards of aviation safety.
Safety promotion will be a very active part of the CAA and the
Digest, seminars and video production will continue to have as
much, if not more, support. The next Digest will include a major
statement by the Chief E x~cut ive of the CAA.
You will notice that this issue includes a survey form in the centre
section . So that the Digest can best serve the aviation community,
would you all please provide some feedback. We need to know if we
are g·oing in the right d irection .
You will see that the centre section of the Digest no longer includes
the accident summaries. This change reflects the more independent
status of BASI, the confidential nature of its accident investigations
and its new confidential reporting system. The accident summary will
continue to be published by BASI as a separate document.
Now is the time to double-check your aircraft 's systems before
encountering IMC, night, conditions of reduced visibility or
turbulence . The little things that are a minor inconvenience during
VFR flight can assume enormous significance when you're 'on the
clocks' - for example; that slight left-wing down indication on the
AH or the blown bulb over the airspeed indicator on the instrument
coaming, or the intermittent OFF flag that occasionally appears on
the turn-and-balance or VOR.
The time is righ t -
15
A hole in one
Not about golf.
16
Aviation winter weather
More gloom .
19
Fences are cheap
Mustangs are not.
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.$.W. 2142,
AUSTRALIA
22
Back. The last 'message' on landings please make a final conscious decision
whether to continue or to go round.
Poster design by Soussanith Nokham.
to fix 'em.
In the centre section of this issue you will find details of the
Bicentennial Air Show and the associated safety activities. The next
issue will include advice as to how to safely fly into and out of, the
very high traffic density airspace around Sydney. Please prepare .
now by ensuring you have all the necessary paperwork and charts
for the trip. There is a list of current Al l's in the centre.
Editor:
Editorial Assistant:
Graphic Design:
David Robson
Karen Hutchison
Lesley Gordon
Photographs.·
BAS!
SMEA
RAAF
P4
P9
P 13
p 10, 11,
AIRFLOW
The readers' column.
Front. There's nothing quite like a
taildragger.
Cessna 185 at Bendigo, 1987.
Photo by David Robson.
NIKON F Fujicolor
The Digest wi ll once again be running its very popular photographic
competition in the coming months in conjunction with Maxwell
Optical Industries who have kindly donated Nikon cameras as pri zes.
Full details and en try forms will be contained in the Bicentenary
issue of the Digest to be d istributed in September. Entry forms will
also be available at photographic shops and at pilot briefing offices.
© Commonwealth of Australia 1986
ISSN 0045-1207
R85/ 979(10) Cat. No. 87 1577 8
the time is right now -
Covers
DAVID ROBSON
Editor
13, 17
P 20
P 13
JBUMET
Kevin Limon
unknown
ANARE
�J
Aviation Safety Digest
137
Aviation Safety Digest
137
It is also likely that he held back stick to
Undercarriage
oops!
reduce the load on the nosewheel as he passed
over the hump. This combination was sufficient
to lift the weight from the squat switch which
is fitted to the nosewheel on this aircraft.
Hence the retraction sequence was allowed to
commence even though the aircraft was on the
ground.
The pilot of the Baron had completed a type
endorsement only two days previously. During
the endorsement the instructor would retract
the flaps during each touch-and-go. Following
the endorsement the instructor recommended
that the pilot conduct a period of solo circuits
to consolidate his training.
A
T 40-50 KNOTS during the takeoff roll, the
pilot heard a loud bang and felt the aircraft
--- adopt a progressively lower nose attitude.
As if in slow motion the nose dug into the surface of the strip and the aircraft turned over
onto its back.
After evacuating the aircaft the pilot saw that
the undercarriage was retracted - both
nosewheel and mains.
The pilot could not positively recall the position
of the undercarriage lever at the start of the
takeoff roll but did not touch the lever during
the takeoff - he maintained one hand on the
t hrottle and one on the control column.
The strip was mostly smooth and hard with
only minor undulations. However, about 200
metres from the eastern end there was a noticeable bump where a water pipe ran underneath.
There was no apparent fault with the U /C system.
[Apparently the gear lever was not in the fully
down position and when the weight of the aircraft was lifted off the squat switch it allowed
the retraction cycle to commence.]
The pilot of the Cessna 210 ferried his wife to
the intermediate stop and then flew the last leg
alone.
The circuit and landing at the destination were
normal until late in the landing roll when the
pilot carried out the after landing checks. He
selected flaps up and then inadvertently selected the gear up instead of opening the cowl
flaps as he had intended.
The warning horn sounded and the pilot
realised his mistake. He immediately selected
the gear down but sensed that the gear had
already started to retract. As he felt the gear
motor operating he pulled the mixture to idle/
cut-off and turned off the fuel and electrics.
The aircraft settled onto the ground in the
centre of the strip.
The strip had a hump in the middle and may
not have met the criteria for an ALA.
It seems that the pilot was still travelling at a
reasonable speed when he selected the gear up.
This may have been to roll through to the end.
After the first circuit the pilot was lined up on
final but was gaining on a preceding aircraft.
To avoid a confliction, he was given approval
to carry out a touch-and-go on the parallel
runway.
The landing was normal. However, during the
ground roll the pilot inadvertently retracted the
gear instead of the flaps. The aircraft settled
onto its belly.
The pilot admits to selecting the lever without
visually confirming that it was the flaps. The
aircraft was travelling at a speed such that
there wouldn't have been sufficient weight on
the wheels to activate the squat switch.
He had only 2.5 hours on this type of aircraft.
All his previous experience was in aircraft
which had the gear and flap lever in reverse
locations.
After selecting the undercarriage down the indicators showed that the left main gear was
unsafe. The pilot diverted to a more suitable
airfield for an emergency landing and tried several times without success to get the gear dow n
and locked.
He then selected the gear up and carried out a
wheels-up landing.
The left gear had not been rigged or lubricated
in accordance with maintenance instructions
and the gear-up-lock roller had seized. The
rollers on both main legs had apparently not
been free to rotate for some time. The pilot may
not have been aware of the need to check these
rollers during the pre-flight inspection.
And one with a twist
As part of a refresher check on the aircraft
type, a Mooney M20, the instructor required the
pilot to use manual system for lowering the
undercarriage. After turning the crank handle
the recommended number of turns, the geardown-and-safe light did not illuminate. The
pilot continued to rotate the crank handle a few
more turns and a loud bang was heard, after
which there was little resistance to further
rotation of the crank.
However, t h e gear down light still didn't illuminate although the visual gear position indicator
in the cockpit did indicate that the gear was in
the down position.
The gear actuator circuit breaker was reset and
the gear was selected up. The gear did not
retract but t he gear unsafe light illuminated.
All further attempts to obtain a gear down light
were unsuccessful. Observations made from
another aircraft and by people on the ground
suggested that the gear was down and locked.
The aircraft was diverted to Bankstown.
Unfortunately the gear collapsed immediately
after touchdown.
It was found that a fault in the gear indicating
system prevented illumination of the gear down
light when the gear reached the down-andlocked position from a manual extension. When
in this case the pilot continued to rotate the
crank, an overload failure of the actuator housing occurred. The gear was unlocked when the
up selection was made but the damaged actuator prevented either retraction or safe
extension.
In this aircraft, the actuator plays a vital role
in retaining the gear in the down and locked
position as it pre-loads t he landing gear braces
in an overcentre position. Once the actuat or
was damaged, the collapse of the gear on touchdown was unavoidable D
Armchair
theatre?
E DISCUSSED previously the potential
benefits of carrying out a post-flight
....... = inspection in the same way as we carry
out a pre-flight, to detect changes or damage or
leaks in time to have them rectified.
A similar benefit can be gained by postflighting (and pre-flighting for that matter) ourselves.
Consider the situation where we have just shut
down. The flight was safe but there were
traffic problems and the radio was hard to
understand at one point. There were no incidents but the landing was a bit firm and the
pre-takeoff checks were a bit rusty.
Instead of rushing to the bar to erase all memory of the flight with the thought, 'Thank goodness that's all over. I can relax now until the
next time.' - Stop and think.
There were lessons from that flight that could
help avoid a similar or worse situation in the
future.
An armchair re-enactment or even a bedtime
re-enactment can provide a relaxed self analysis that can only be of tremendous benefit.
From the time we gain our licence we rarely fly
under the scrutiny of another pilot - thank
goodness. But we do have the best judge in the
world with us - ourselves. If we are absolutely honest with ourselves and thorough about
our self analysis then we know exactly what
we did correctly or incorrectly, what we were
familiar with and what we had to guess or
bluff our way through. We know whether the
aircraft really is fully servicieable. We know
whether we were at risk or whether we were
fully prepared and competent in our handling
of the flight.
What a terrifically valuable facility to have!
Perhaps the best basis for pre-flight planning is
an honest post-flight analysis of the previous
trip D
�Aviation Safety Digest
137'
Aviation Safety Digest
137
The Maintenance
release - Flight
Crew aspects
T
HESE NOTES have been prepared to give
guidance to persons operating aircraft that
.!_ are maintained to the requirements of ANO
100.5.1 and the Department of Transport and
Communications form DA 741 Maintenance
Release which is issued on completion of
maintenance.
The issue period for a maintenance release is
nominally 100 hours time in ser vice or 12
months from its time of issue. By r eferring to
t he maintenance release document, it will be
seen at the top of Part 1, t h at the date and
total aircraft t ime in service when reached, will
cause the maintenance release to no longer
remain in force i.e. expire.
ANR 108(1) states in part that an a ircraft shall
not commence a flight unless it has a maintenance release in force covering the period of the
flight and the flight is not in contravention of
any condition set out or referred to on the
maintenance r elease. Unless otherwise
approved, the maintenance r elease must be carried on a ll flights (ANR 113 refers).
~
Daily inspections
Let us now consider Part 3 of the maintanence
release. This is w here certifications for the
daily inspections are made and w her e time in
service is to be recorded. Daily inspections are
required to be performed prior to the first
flight of each day (requirement is specified in
para 3 .1(5) of ANO 100 .5 .1). A daily inspection
may be p erform ed b y the pilot-in-command
(being other than a student pilot) in which case
certification is not required. If the daily inspection is performed by other than the p ilot in
command, certification is required. The only
persons authorised to certify for a daily inspection are:
• An appropriately licensed AME.
• The holder of an appropriate maintenance·
author ity covering t he maintenance.
• The holde r of a valid commercial pilot licence
(or higher) endorsed on the a ircraft type or
group (with sufficient know ledge and
experien ce) .
• Other pe rsons as specified in the regulating
document w hich is para 4.2(1) of ANO
100.5.1. It is of interest to note that the
holder of a priv ate pilot licence is not authorised to certify for a daily inspection.
Time in service
Time in service is defined in ANO 100.5.0 and is
the time from wheels OFF to wheels ON. It is
required to be entered on the maintenance
release at least at the end of each days flying
(para 8 of Appendix 5 to ANO 100.5.1). By
referring to Part 3 of the maintenance release
document, a space can be seen at the very top
of the progressive total column to record the
aircraft total t ime in service at the time the
maintenance release is issued . It is then only a
matter of recording an entry after each days (at
least) flying and adding this time progressively
in the second column (progressive t otal).
Endorsements: (Defects unserviceabilities)
permissible
A proper understanding of the use of Part 2 of
the maintenance release is necessary and let it
be clearly understood that THE ENTERING OF
A DEFECT ON THE MAINTENANCE RELEASE
DOES NOT AUTOMATICALLY GROUND AN
AIRCRAFT.
It is important to understand the proper
rel~tionship to the appropriate pieces of legislation of defects, unserviceabilities and damage.
A defect by definition is a lack of something
essential to completeness, a sh ortcoming. It
does not mean something is necessarily unserviceable or damaged. Let us consider some
defects in this context: - e .g.
- The engine primer is stiff and hard to operate, it can be u sed w ith some difficulty but
is of little consequence - the engine can be
started quite normally u sing the throttle
operated accelerator pump.
'VHF COMM - squelch breaks through
occasionally, but not affecting reception. '
The parking brake handle will not always
lock in the parked posit ion on first attempt
to park the brakes - after second or third
attempt it locks in park.
ANR 49F requires the owner, t he operator or
flight crew member, once they become aware of
the existence of a defect in an aircraft, to
endorse the maintenance release with particulars of the defect and to sign t he endorsement.
The defect having been committed to paper,
now provides a means for the n ext person who
may wis h to fly the aircraft with the necessary
information to allow a proper judgement to be
made against other requirements as to whether
h e can fly with the defect or h ave maintenance
performed before he flies. It a lso provides a
person likely to p erform mainten ance on an aircr aft with t he necessary information to decide
on appropriate action.
Referring back to ANR 108(l)(c) one of the
requirements before commencing a flight is that
all defects and conditions are considered and
that the flight will not be in contr avention of
any condition set out or referred to in the maintenance release.
The requirements of ANR 236 must be considered by the pilot-in-command before he commences takeoff. This Regulation requires him to
establish satisfactory engine preformance,
check instruments and perform such checks and
tests required by the flight manual or operations manual. Para 8 of ANO 20.1 8 requires all
instruments and equipment fitted to an aircraft
to be serviceable prior to takeoff, subject to
certain qualifying provisions.
Section 5 of an aircraft flight manual specifies
mandatory instruments and indicators which
must be fitted to an aircraft and be serviceable
prior to takeoff.
As can be seen from the above, the pilot-incommand has requirements placed on him for
determinations to be made before flight and if
we consider those defects quoted as examples
earlier in t hese notes, it would be found that
those defects would not preclude further flight.
Let u s now consider unserviceability. When a
component can no longer render service and
perform its design function it becomes unserviceable . Thinking back to our defective VHF
Comm - our problem has degenerated to a
s ituation where the squelch breakthrough is
n ow continuous and VHF reception is unreadable - this unit is now u nserviceable.
The last problem for consideration is damage,
some form of physical defect such as impact
dents or tears in the s kin, control surface
attachments cracked as a r esult of air loads,
undercar riage members buckled result ing from
ground-loops etc.
Remember - all unserviceabilities and damage
are defects, but, all defects may not necessarily
by unserviceabilities or damage. ANR 42 provides a means of having defects and damage
approved as permissible unserviceabilities. For
the general av iation sector such approval is
granted by Department of Transport and Communications only. Permissible unserviceabilit ies
a re not usually approved for aircraft in current
use for private, aerial work or charter operations wit h the exception of those that are
approved through ANO 20.8 or ANO 20.18.
Where a permissible unserviceability is
approve d by any of the above methods, ANR
49E requires that the permissible
unserviceability is endorsed on the maintenance
release along with any condit ion required to be
observed when operating with the
unservicibility. The respon sibility for complying
with the requirement of ANR 49E is imposed
upon the owner , operator or flight crew member and he is required to s ign the endorsement .
We now come to the final set of circumstances
which, if encounter ed, provide the means for
endorsing t he ma intenance release to declare an
aircraft to be unairworthy and in so doing,
legally ground the aircraft. ANR 49C requires
an owner, operator or flight crew member who
considers that:
(a) A maintenance requirement has not been
complied with.
(b) The aircraft has suffered major damage or
developed a major defect (major damage
and major defect are defined in ANR 5).
(c) The aircraft has had abnormal flight or
ground loads imposed on it;
and there is a likelihood that the aircraft may
be flown before corrective maintenance can be
performed, the maintenance r elease shall be
endorsed setting out the facts of the situation
and declaring t he aircraft to be unairworthy.
The maintenance release now ceases to be in force.
Once a maintenance release has been actioned
under the provisions of ANR 49C it can only
recommence to be in force under the provisions
of ANR 49D. When appropriate corrective maintenance has been performed and certified, the
authorised person after satisfying himself that
the reason for the ANR 49C endorsement no
longer exists, shall then make a further
endorsement cancelling the ANR 49C endorsement and sign it. The pilot-in-command of an
aircraft operating in any class of oper ation
other than under an Airline Licence is a person
who is authorised to make such a cancelling
endorsement. (Refer to ANR 49D(2)).
In concluding these notes it must be clearly
understood that where reference has been made
to specified ANR's and ANO's only abridged
ver sions of the texts have been quoted for
easier reading. Please read the specified
requirements fully to see and u nderstand the
legal requirements. The maintenance r elease is
a legal document and failure to comply with the
requirements can r esult in a breach of the Air
Navigation Regula tion s.
Consider t he following:
(a) When checking t he maintenance release
before flight, make su re it has been issued
to cover the class of operation you ar e
about to embark on. Remember ANR 108(1)
(c)! Your class of operation should not have
been deleted from the box in the right hand
top corner of Part 1 of the maintenance
release document. Also en sure all required
maintenance h as been completed and
certified.
(b) If you are operating away from a fixed base
carry the a ircraft log books w ith you . A
LAME cannot make a clearing certificat ion
against a defect entered on the maintenance
release unt il he has made appropriate
entries and certification in the air craft log
book. Read Appendix 5 to ANO 100.5.1.
(c) Para 6.9 of ANO 100.5.1 requires the owner
(or operator) of an a ircraft to retain an
expired maintenance release for at least one
year from the date it ceased to be in force D
�Aviation Safety Digest
137
Aviation Safety Digest
37
Rime ice
Airframe Icing
This is a porous, white, usually granular form
of ice which is not as dense as clear ice. Rime
forms when water droplets freeze as fast as
they accumulate. Since this freezing is almost
instantaneous on striking the aircraft there is
no excess of liquid so the rime freezes where
the water droplets hit. This will usually be on
the leading edges and on protruberances such
as antennas, steps, thermometer probes etc.
Rime is not as strong as clear ice and is usually
removed more easily .
Mixed forms of ice
Bill Mcintyre is Chief Pilot with the Snowy Mountains
Hydro-Electric Authority. He has been flying fixed and
rotary wing aircraft out of Cooma for over five years and
has personal experience with the various forms of icing
that he mentions in his article.
(""} ILOTS WHO operate IFR in the southern
C-' areas of Australia during winter will
l eventually find themselves in an icing situation. Unfortunately there is not a great deal of
literature available to GA pilots to enable them
to prepare themselves for their first encounter.
It is not surprising, then, that most new pilots
look forward to this event with considerable
dread. The purpose of this article is to give
some practical advice on what to expect.
If you fly an aircraft in cloud at temperatures
around 0°C or below you can usually expect to
accumulate some form of ice. The type of ice
and the amount accreted depends on several
factors, including temperature a nd size of the
water particles. There are three basic types of
ice that concern us.
Clear ice
This is a glassy transparent or whitish form of
ice that adheres tenaciously to exposed surfaces. It accumulates most heavily on all forward facing surfaces including the leading
edges of the wings, empennage and propellers.
It often forms in successive smooth strong
layers and is difficult to remove ex cept by
bre aking t he seal between it and the underlying
surface or by melting.
Clear ice is formed when wat er accumulates
faster than it freezes by collision with raindrops or cloud droplets, so that the outer surface is always wet with an excess of free
water. It generally conforms to the shape of the
structure to which it freezes and is slow to distort the form of the leading edge of the wing.
Excess free water will flow back over the top
and bottom of the wing and freeze there,
roughening the surface.
Not all ice encountered will be either clear or
rime exclusively. As conditions vary between
those forming clear and those forming rime, any
intermediate forms of ice may result. If snow is
encountered together with clear ice conditions,
snowflakes may adhere and freeze to leading
edges, producing a thick rough accumulation in
a short time. It is even possible that wet sticky
snow may pack on the leading edges·. Dry snow
or ice crystals will not adhere to an aircraft
and so therefore do not present an icing hazard.
The rate at which ice accumulates is directly
related to the amount of water particles that
hit the aircraft. It follows, then, that
cumuliform cloud will present more water to
the aircraft and so therefore create a worse
icing situation than stratiform cloud where the
water particles are smaller. Cumulonimbus
clouds, because of their high water content,
cause some of the most severe icing conditions.
Many pilots think that the major problem with
ice accretion is the increase in weight that the
aircraft is required to carry, but this is just the
tip of the iceber g. Other factors of vital importance are:
• decreased propeller efficiency,
• decreased lift caused by deformation of the
aerofoil,
• increased drag.
All of these factors in concert cause a requirement for more power to maintain the desired
airspeed and a higher stalling speed caused by
the deformation of the aerofoil section. Aeroplanes with high wing loading can be very
quickly affected by ice.
Preflight considerations
The first line of defence against an ice affected
flight is to avoid icing conditions in the first
place. Forecasts give ample information on
cloud types and levels, temperatures and freezing levels and significant icing. Careful flight
pla nning will often allow you to avoid icing
regions even on the worst days.
If flight into known icing conditions is unavoid-
Some additional points to remember
able it should be kept to an absolute minimum
and even then it should only be undertaken in a
properly equipped aircraft and after careful
preflight checks. All de-icing equipment should
be inspected for proper operation including a
functional check of the anti-ice/ de-ice on the
propellers, airframe, windshield, engine int akes,
fuel vents, stall warning v anes, pitot heat and
the outside air temperature indicating system.
It should be appreciated t hat prolonged flight in
known icing conditions is highly undesirable,
even in aircraft t hat are certified for it. The
best possible outcome will be longer time spent
en route cau sed by a r edu ced airspeed. Use
your de-icing equipment to enable you to fly
clear of icing condit ions.
• All electric de-ice or anti-ice equipment should
be turned on well in ad vance to allow plenty
of t ime for it to warm up.
• Follow the manufacturer's instructions carefully when using pneumat ic de-icing boots.
The amount of buildup before activiation is
critical. Too much accumulation might be
impossible to shed, too little might only crack
and not break off cleanly . This allows a build
up of more ice over t he top, r endering the
boots u seless. Most systems require half a
centimetre to function correctly.
• Clear ice will often break off in line with the
rear of the de-icing boot creating a ridge
which adv ersely effects the performance of
the wing.
• Rime ice sometimes forms a thin bead along
t he leading edge of t he w ing. Although it
looks innocent enough, it can create a dangerous situation on landing by increasing the
stalling speed.
• Many manufacturers have warnings in their
Pilot Operating Handbooks about the use of
flap when t here is an accumulation of ice on
the wings. Make sure that y our aircraft has
no restrictions after a flight in icing
condit ions.
• Find out the handling characteristics of your
aircraft and its de-icing system before you
need to use it in an icing region. All aircraft
behave differently, some are mo re bao1y
affected t han others.
In s ummary, encounters wit h ice are like everything else in aviation, they require preparation,
planning and a clear rehearsed understanding
of what to do when the going gets tough. If
Jack Frost gets you in his clutches make sure
you know what to do D
In flight actions
On first entering an icing region the pilot needs
to make an immediate decision about extricating himself from it. In order of priority, these ar e:
1. Cli mb. In many cases t his will enable a
cruise on top of cloud and clear of ice or at
a level that is so cold t hat ice will no longer
form. Limiting factors are lack of pressurisation or oxygen and the aircraft's maximum
operating ceiling. Cloud of consider able ver tical extent may be beyond your aircraft's
capability .
2. Descend. Descending may enable a cruise at
temperatures above the freezing level or
clear of cloud. The only limiting factor is
the lowest safe altitude in t he icing region.
3. Go back. If climbing or descending is not an
option then proceed back to where the icing
conditions started and re-plan from there.
In s hort, before going in to an icing region,
make sure you have an 'out' .
�Aviation Safety Digest
137
Aviation Safety Digest
137
VISUAL (VIS)
Satellite pictures
Contributed by the Bureau of Meteorology
The VIS picture shows a generated area of scattered to broken
cloud over parts of Cape York Peninsula.
DN
A WEATHER Service Office th ere are
ii usu ally displayed two types of satellite pie-
.. t ures, labelled VIS and IR. This article aims to
provide pilots w ith some basic facts about t hese
two types of satellite data in order to better
understand briefings provided by Bureau of
Meteorology staff, as was recommended at t h e
Second Aviation Workshop in June 1986. It
must be stressed t hat satellite data alone does
not completely describe t he state of t h e at mosph ere; it combines w ith convent iona l and computer generated d ata t o build up a
comprehen sive picture of t he atmospher e.
Visual satellite pictures (VIS) show us in black
and white the view we would see if we were
located on the satellite. The image is based on
reflected sunlight, and clouds a re, in general,
good reflectors. The best reflectors are
cumulonimbus, large cumulus, and all thick
clou ds as they reflect most of t h e sunlight that
strikes t hem , and ~hey appear w hite. Thinner
clouds are gen era lly not so w hite because less
light is reflected.
Unless cumuliform clouds spread out at higher
levels into s heets (as often happens in the
t r opics) they appe ar on visu al pictures as discrete clouds w it h spaces in between . Wh en the
sun a ngle is low, cumulus tops cast shadows
result ing in a textured pattern. In general,
cumuliform clou ds are eviden t by t heir lumpy
appearance, while stratiform clouds appear
flatter.
In winter t he illumination is poor and in general, clouds are not well represented on VIS
pictures.
Infrared pictures (IR) display the relative temperatures of the cloud tops, or the earth's surface ~{ the area is cloud-free. If there are
several layers of cloud at a location then the
temperature displayed is that of the highest
cloud top. Cloud tops which are cold (of the
order of - 30°C or colder) - eg cirrostratus or
cumulonimbus, appear white. The earth's surface itself on a hot day (of the order of 30°C or
higher) appears black. Temperatures in
betw een + 30°C and -30°C are shown as
varying shades of grey, with warmer temperatures being dark grey and temperatures
approaching -30°C, light grey.
Because the temperature at the top of a fog or
low cloud layer is usually fair ly similar to the
temperature of the adjacent fog-free earth's
surface it is very difficult and on most
occasions impossible to discern fog/ low cloud
on IR imagery. Clouds with the coldest temperatures are best represented on IR pictures .
Satellite imagery is normally available at
approximately three hourly intervals, with visual pictures of course only available in daylight
hours. IR imagery, with its availability at
steady intervals, does enable the movement and
development of clouds and cloud systems to be
followed ; some clouds do u ndergo their life
cycles w ithin three hours and do not necessarily appear on satellite pictures at all.
The best result is obtained when the two types
of pictures can be used in conjunction. The sate llite pictures (opposite) are sections of pictures
taken at 0300 UTC 29 March 1987. They provide a 'snap-shot' of conditions at that time,
and the commentary indicates how certain features become apparent when the VIS and IR
pictures are considered together D
There appears to be more cloud over inland WA on the IR picture.
Cirroform cloud is more easy to recognise on IR pictures.
EARTH'S SURFACE (SHOWN BLACK) - - - -- - -,
COLD HIGH CLOUD TOP (SHOWN WHITE)- - - -,
LOWER LEVEL CLOUD TOP (SHOWN GREY)
The VIS picture shows scattered cloud over inland WA.
t
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The IR picture highlights the areas of coldest and highest cloud
top (thus strongest vertical development) as white.
J
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·"'
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IL
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The VIS picture shows clouds associated with major synoptic
patterns over SE Australia and The Great Australian Bight.
The IR picture gives a better idea of the cloud tops (see captions).
However low cloud may be masked by higher cloud .
�Aviation Safety Digest
137
Mountain wave
activity and its
effect on aviation
If you are not eligible for a free issue, or if you would like additional copies of the Digest:-
In Australia mountain wave activity is most
likely to be encountered over and to the lee of
the mountain systems of southeast ern Australia, south from approximately latitude
26°30'.
The dangers of mountain waves
(i) Vertical currents
The most usual danger is the large sink
rates on the 'downside' of mountain waves.
An aircraft flying along the lee side of a
lengthy mountain range might remain in a
downcurrent continuously until the whole
length of the mountain range h as been traversed. In such circumstances a catastrophic
loss of height could occur.
The extent to which an aircraft's flight path
will be affected by mountain waves is
dependent not only on the severity of t he
waves and the speed of the airflow, but also
on the type of aircraft and its track a nd
ground speed. Crossing a ridge of high
ground into the wind when winds are
strong and mountain waves are ·likely can
be much more hazardous than doing so
with the wind. There are two r easons for
t his - firstly, when fly ing into the wind
the aircraft's ground speed is reduced and it
will therefore remain in downcurrents
longer; secondly, where no attempt is made
to counteract h eight changes, the aircraft's
height variations when flying into the wind
are out of phase with the standing waves,
so the aircraft is at its lowest height when
it is a ctually flying over the highest ground
(see diagram).
For downwind flight the reverse is true, ie
the aircraft's involuntary height fluctuations will be in phase with the airstream
waves and, provided that adequate terrain
clearance is maintained, there is less likelihood of the aircraft being forced dangerously close to t he ground by downdrafts.
Bureau of Meteorology
M
OUNTAINOUS or hilly country acts as an
impediment to any low level air flow,
_
with the air forced to rise up the windward side of the mountain barrier. If the atmospheric conditions are favourable th en the air,
once it has passed over the barrier, begins to
sink down the lee side of the mountain and
then forms a series of standing waves downstream from the barrier. In ideal conditions
these waves can continue downstream from the
mountain range for many hundreds of kilometres and be felt high into the tropospher e.
For wave formation the wind must be blowing
more or less perpendicularly to the ridge, with
wind direction remaining fairly constant with
height. The wind speed at ridge level must
exceed a certain minimum, dependent on the
he ight of the ridge, but generally this minimum
figure is regarded as about 20 to 25 knots .
$A 16 •00
•
or over thirty years, the Aviation Safety
Digest has been an integral part of
Australian aviation .
•
I
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In July 1986, responsibility for the Digest was
transferred from the Bureau of Air Safety
Investigation to the Flight Standards Division of
the Australian Department of Transport and
Communications. This move reflected the
perception that civil aviation may have reached
the limit of accident prevention through
regulation and that the way forward is through
increased emphasis on safety education in
general, and the 'human factor' in particular.
Rather than just draw lessons from accident
investigations. the Digest will increasingly seek
(;nclud;ngsudacepos/age)
to influence pilot behaviour by positive
reinforcement of sound techniques. It will
examine all aspects of piloting and publish
formal results as well as 'the tricks of the trade'.
The 'crash comic' will become a 'how not to
crash' comic .
Anyone with an interest in aviation will benefit
from tapping into this unique source of the
accumulated wisdom of the profession and
the latest research into aviation safety in
Australia. Indeed, anyone with an interest in
high technology and the roles and limitations
of the human operator will find this publication enlightening.
30
30
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Feeling a ITttle query?
LENTICUL AR CLOU D
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The AIRFLOW column is intended to pror:iote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is particularly welcome.
Anonymity will be respected if requested .
'Immunity' applies with respect to any
self-confessed infringements that are
highlighted for the benefit of others .
Write to:
AIRFLOW
Aviation Safety Digest
P.O. Box 367
CANBERRA A.C.T. 2601
Australia
10
5
5
Aviation Safety Digest 137 / i
Km
0
8
16
�Public transport will be provided for pilots and their passengers between Schofields and
Richmond, and will include train and bus services, rental cars and charter helicopters.
Crews will not be permitted to camp at Schofields, and all pilots will be issued with
airfield passes to ensure control of access to aircraft and tarmac areas. At night, a
professional security firm will be employed to ensure the security of visiting aircraft.
Aircraft refuelling will be by way of mobile tankers, which will meet arriving aircraft in
the parking area. Both A vgas and Avtur will be available.
An aviation maintenance organisation will have staff available at Schofields to perform
minor aircraft maintenance.
The Australian Bicentennial Air Show 1 to be held at RAAF Richmond, near Sydney,
between 12-16 October, will be the largest aviation event ever held in the Southern
Hemisphere, and the aviation centrepiece of Australia's Bicentenary.
Combining an international Aerospace Expo, an Australian General Aviation Trade Fair,
extensive flying displays, and static displays featuring the history of civil and military
aviation in Australia, and the use of aviation in the community today, the Air Show is
expected to be one of the largest single events of the Bicentenary year.
In addition to attracting a large number of civil and military aircraft from overseas, it is
anticipated that large numbers of Australian General Aviation pilots will want to fly-in to
the event.
Because of the large number of static and display aircraft that will be on the ground,
parking space at RAAF Richmond will be severely limited, and only display aircraft and a
limited number of approved charter flights will be able to operate into the RAAF Base.
Schofields Aerodrome
All other General Aviation aircraft will be catered for at Schofields, 9run southeast of
Richmond, where full-scale aircraft reception and refuelling facilities will be provided by
the Australian Bicentennial Air Show Organisation and the Schofields Flying Club.
Schofields will be open to visiting aircraft between Monday, 10 October and Wednesday,
19 October. Because of the likely traffic volumes, pilots are encouraged to plan their visit
to the Australian Bicentennial Air Show over several days.
Using tarmac and grassed areas at Schofields and the adjoining HMAS Nirimba, parking
for up to 800 General Aviation aircraft will be provided. In wet weather, a minimum of
400 aircraft can be catered for.
The Air Show Organisation will provide parking, ground transport, aircraft refueling,
crew reception, domestic facilities and airfield security at Schofields.
All visiting aircraft will be met by Air Show representatives, and transport will be
provided to the Aircraft Reception Centre in the Schofields Flying Club building.
This facility will include information services, refreshments, comfort stations, car hire,
accommodation information, transport to and from Richmond, entry ticket sales,
telephones, fax and telex.
iv/ Aviation Safety Digest 137
Accommodation
Visiting pilots can arrange accommodation through the Hawkesbury Regional Tourism
Centre (045) 77 5915, the Penrith Tourist Information Centre (047) 32 2330, or the Blue
Mountains Tourist Accommodation and Tour Booking Service (047) 39 6318, 24-hour
Information Hotline (04 7) 39 1177.
Alternatively, fly-in pilots may elect to use camping facilities being made available in the
grounds of the Hawkesbury Race Club, adjacent to the RAAF Base. Enquiries to the Race
Club Secretary-Manager, Mr Stewart Allsop on (045) 77 2263.
The Australian Bicentennial Air Show Organisation is planning a number of social
functions for fly-in pilots and display participants on the Friday, Saturday and Sunday
nights of the show; details will be available at the Aircraft Reception Centre at
Schofields.
The first three days of the Air Show (Wed-Fri 12-14 October) will be trade days, entry to
which will be restricted to those with a professional or commercial involvement in the
aviation or aerospace fodustries, student and private pilots (on production of their
licence), attendees at the various conferences and symposia being held in cortjunction
with the Air Show, or those aviators who have purchased membership in any of the
various Air Show clubs being offered.
Persons under the age of 18 will not be permitted to the trade days, except where they
are holders of a current flight crew or aviation engineering licence.
To assist planning for the reception of aircraft flying in to Schofields, and so that
information can be sent to fly-in participants, pilots are urged to register in advance with
the Air Show Organisation.
Names and addresses, with details of aircraft type and registration and likely number of
persons on board, should be sent to:
Bicentennial Fly-in Co-ordinator
Australian Bicentennial Air Show
PO Box 338
RIVERSTONE NSW 2765
Telephone: (02) 626 6211
Aviation Safety Digest 137 / v
�EXAMINATIONS AVAILABLE DURING THE BICENTENARY AIR SHOW
PPL FLIGHT RULES AND PROCEDURES
CPL SUBJECTS FOR FIXED AND ROTARY WING
CPL FINAL EXAM
THE INSTRUMENT RATING EXAMINATION
BASIC GAS TURBINES
•
AIR SHOW INVOLVEMENT
The PPL FR&P will be of particular interest to visiting pilots from overseas who wish to fly in
Australia. Licences can be validated on the spot.
Of special note is an opportunity for feedback during the course of the examination schedule.
There will be presentations and an opportunity for discussion before the Instrument Rating
Exam and the BGT so that pilots can gain a better understanding of such thing as PANSOPS.
Similarly there will be feedback after the marking of the CPL Finals for those pilots who
would like to know specifically how they went.
Normal exam rules apply. Please refer to AIC C01/1988 and new AIC's to be issued in July
for complete requirements. Obviously entrants for the CPL final must have first passed the
individual subjects, including those attempted during the show. Exam marking will be such as
to allow this.
All of the exams will be available without prior request but since there is expected to be a
considerable demand for these exams you are requested to complete the enclosed notice of
intent. Those who have notified us will receive priority for sittings.
-
· CIVIL AVIATION AUTHORITY
The proposed schedule is as follows:
WEDNESDAY 0900 - 1200 CPL individual subjects and CPL Final
1300 - 1500 Instrument Rating Briefing
1530 - 1830 Exams as requested (except Instrument Rating)
1900 - 2100 PPL FR&P briefing for overseas pilots
THURSDAY
0900 - 1200 Exams as requested including CPL Final
1330 - 1500 BGT briefing
1600 - 1900 Exams as requested
FRIDAY
1500 FEEDBACK on CPL Final
Fees can be paid on-site and all reference material will be on sale at the Departmental shop
adjacent to the examination centre.
•
The Civil Aviation Authority will have a
significant presence at the Bicentennial Air
Show in October. Details will be included in
the Spring Issue of the Aviation Safety Digest.
Activities include:
• Mounting of a corporate CAA static display
with special industry briefings conducted on
the trade days.
• Mounting of a separate CAA Safety Promotion
display.
• On-site exams up to CPL Final with special
briefings and de-briefings.
• Sale of operational publications and reference
material; and
• A major Aviation Safety Seminar on Friday 16
October.
To:
Flight Crew Examinations Section
Flight Standards Division
PO Box 367
CANBERRA ACT 2601
NAME OF CANDIDATE:_ _ _ _ _ _ _ _ _ _ _ _ _ _LICENCE NO.:_ _ _ __
BICENTENNIAL AIR SHOW 1988
Yi/ Aviation Safety Digest 137
�--
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Aviation Safety Digest
137
•
Visual detection
of mountain
waves
Since Flight Standards Division assumed responsibility for the Digest, we
have experimented with a new look and with new columns - and we felt it
was about time we checked to see if you think we're heading in the right
direction. Please complete the enclosed form so that we can deliver the
magazine that you think would make the most positive contribution towards
safer flying.
Bureau of Meteorology
1. The Format.
Is it the best size, shape and presentation for the material it contains?
1ft ·
•
2. The Style.
Is the style appropriate to the content and nature of the material?
3. The Timing.
Is the frequency and the lead time responsive enough to the needs of the aviation
community?
I
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4. The Content.
Is the content appropriate and correctly targeted?
('
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5. The Emphasis.
Is the right emphasis given to the areas most needing of attention?
I
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6. The Future.
How should the Digest be changed to better contribute to aviation safety?
viii/ Aviation Safety Digest 137
OUNTAIN WAVES can often be detected
1\ " by the presence of characteristic lenticu-
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(ii) Turbulence
Although flights through mountain waves
are often ver y smooth, turbulence can be
encountered at a ny level in mountain wave
systems and may, on occasions, be as violent as t hat encountered in severe thunderstorms. The worst turbulence encountered
over mountainous t errain is usually found
in rotors . Generally speaking, when conditions are favourable for the formation of
mountain waves, the only sure way of
avoiding flight through a turbulent rotor
zone is to allow an adequate ma rgin of
safety height above the high ground. All
evidence indicates that this margin should
be at least the height from the surface to the
ridge again above the actual ridge top. On
occasions rotors have been encounter ed at
higher altitudes, and this h as usua lly
occurred at the base of strong temperature
inversions or at levels at which there is a
sudden change of wind speed or direction.
A pilot must bear these factors in mind
when mountain wave activity is forecast,
and assess the situation before deciding on
his route. In extreme cases it may be necessar y, and certainly preferable, to plan a
diversion rather tha n risk flight over mountainous terrain D
.... lar (lens-shaped) clouds which may form
in the wave crests, if there is enough moisture
available. The ascending air produces condensation, and the descending air evaporation. The
lenticular or wave cloud remains more or less
stationary in the crests of the waves. The turbulent nature of the airflow is apparent if the
clouds display rotational characteristics. In
these circumstances rotors must be suspected.
Frequently there may be no visible warning of
the existence of waves or rotors when they form
in dry air and therefore have no accompanying
cloud. This will be hazardous for the unwary
pilot.
Evidence from satellite pictures
Satellite pictures may reveal mountain wave
activity as a series of regularly spaced cloud
bands in the lee of the mountain chain. The
spacing between clouds indicates the wavelength of the mountain waves. However, mountain waves may be present without evidence on
satellite pictures because the atmosphere may
be too dry to produce cloud, or a layer of
higher cloud may mask the lower level clouds
indicative of mountain waves.
�Aviation Safety Digest
137
Aviation Safety Digest
137
The main objective for the new format was simplicity - in presentation and interpretation.
The New Area
Forecast
oe- HE BUREAU of Meteorology and the
Department recently undertook a review of
..,... the presentation of the area forecast - the
ARFOR. As a result, a new format was introduced last December and many of you will be
familiar with the new plain language layout.
Only certain abbreviations were to be used and
headings and indentation were adopted to aid
legibility.
I couldn't see any cloud at all on our track as
we departed PMQ.
A hole in one
Additionally, guidelines for combining areas
were agreed; areas may be combined when the
weather in these areas is substantially similar.
Areas may be subdivided when specific, identifiable, operationally significant weather can be
localised.
These changes are designed to make the forecast more 'user friendly'. When you have had a
chance to use the new format we would
appreciate your constructive comment and
suggestions D
AMENDED ARFOR Area 21/22 Valid 05 1700 to 060700
OVERVIEW: A moist onshore coastal stream, bringing low cloud to eastern ranges and coastal areas.
SUBDIVISIONS
A: Eastern ranges/coastal areas
B. Western ranges a nd inland
WIND:
10000
7000
5000
2000
230/ 15 PS06
230/ 15
A: 140/10
160/10
240/20 PS05
240/ 15
240/10
B: 240/10
CLOUD AMD
1000-4000
A: BKN St
2500-8000
BKN Cu/Sc
5000-10000
B: SCT Cu
WEATHER
A: Areas drizzle
SCT showers
B: Nil
VISIBILITY
A: 3000M in sh owers
5000M in d r izzle
B: Good
FREEZING LEVEL
12000
TURBULENCE .
Moderate in Cu
ICING
Nil
CRITICAL LOCATIONS
Mt Victoria
2000M drizzle, BKN St 3700 above MSL
Bowral
4000M drizzle, BKN St 3000 a bove MSL
GRADU 0102 10 km, BKN Cu/Sc 4000
14000
270 /20 MS02
260/20 PSO l
18500
270/30 MSll
270/30 MSll
From visual fixes , I kept a log of groundspeed
and time intervals. At 1045 (local) the cloud
had developed to four oktas with tops to 4000
feet. The wind for 5000 feet was VAR/ 10 knots
and at 7000 feet, it w as 150/ 10 knots. I felt
that the wind was stronger than forecast and
that the cloud was orographic. A groundspeed
check confirmed that we were getting an ext ra
five knots so I concluded it would be clear on
the other side of Barrington Tops. I looked
behind me and the cloud dissipated to nothing
on the coast.
My last visual fix was only about five minut es
later. I just couldn't believe it! I was on top of
eight oktas. We were cruising at 8000 feet and
t here was about three thousand feet between us
and the cloud.
E PLANNED to fly from Port Macquarie
to Scone in a Cessna 172.
I t hink it was about 7:30 am when I
called the Coffs Harbour briefing office. They
didn't have a TAF for Scone so as a rough
guide, I asked for Tamworth's.
When I submitted the flight plan, Scone's TAF
came through and I noted it. The forecasts
looked reasonably good so I decided to go to Scone.
We departed Port Macquarie 27 minutes after
ETD and the forecast looked as accurate as
they usually are - for this time of t h e year.
There was h ardly any cloud at Port Macquarie
and the sun was shining brightly. Scone was an
hour's flight away w ith only two oktas at 1000
feet and two oktas at 2500 feet .
I called Sydney on 124.8 and for an 'actual' for
Scone. They replied, 'Scone TAF update, are
you ready to copy?'
He s aid something about an INTER and then a
TEMPO and I copied down the worst of it. It
didn't look so good so I advised my passengers
that I might have to divert to Tamworth. They
were disappointed and so was I - for not looking as professional a s I should - for not getting them where they wanted to go.
From Scone we headed to Tamworth via Werris
Creek (NDB) and the cloud tops were far below.
We could see Willow Tree through a very big
hole in the cloud and I was able to do a slow
rate, descending turn and amend the flight plan
again for Scone.
We were just on VMC minima all the way
towards Scone but there was a break in the
heavy rain and I could see a town w hich I
believed was Scone. (It turned out to be
Murrurundi.) Still not accepting the fact that it
may not be Scone, I turned toward the lower
country to the West to maintain VMC. A quick
check of my map confirmed that I still had
about 15 miles to run and that I was on the
north-western side of the Liverpool Ranges. I
didn 't accept this . I still don't know w hy . It
seems obvious now.
I quickly checked behind to see if there was a
way out and I found to my dismay t hat cloud
was completely blocking t he valley that we had
come through. The cloud hadn't rolled in from
any part icular direction - it had just formed!
I looked around in front of me and the valley
came to an abrupt end behind which was a hills ide enshrouded in cloud!
I quickly got onto the 'clocks' and saw that I
was in a 30 degree banked turn to the left. I
levelled the wings on the Artificia l Horizon,
applie d full power and climbed. I transmitted
some sort of garbled PAN call and noticed trees
flashing past less than fifty feet below the a ircraft. I thought I had killed us all.
�Aviation Safety Digest
137
Back on the panel, I saw that the aircraft was
climbing at an amazing 1500 fpm. My aircraft is
fit ted with a coarse pitch prop and rarely
climbs at more than 500 fpm . Our weight was
about 1900 lb. The airspeed was 55 knots, so I
lowered the nose slightly and settled on 65
knots only to see an average climb r at e of just
under 500 fpm.
My passenger in the r ight seat screamed out,
'Hang in ther e, get us out of here!'
Sydney FS said something about control of the
aircraft and I replied, 'Affirmative! '
We had climbed from 2800 feet to 4300 feet by
this stage. I thought we would be visual by
5000 feet but we weren't until 6500 feet. We
continued to climb to 8000 feet.
The tops were building up so rapidly I just
could not believe it. It was like time-lapse photography - and more cloud was appearing as
if from nowhere.
I climbed to 9000 feet and the tops were at
eight. I climbed to 10000 feet and the tops
approached nine. I fina lly cruised at 10300 and
still there was less than 500 feet separation. I
was told that we were 68 miles from Port
Macquarie.
I remember forgetting all my radio procedures.
I said to Sydney FS, 'There's a hell of a lot of
cloud up h ere, y ou know. I don't see how I'll
ever get down visually .'
They asked me to check the wings for damage
and to see that the doors weren't popping. Now
don't you think I would have noticed that? I
could only presume that they thought the aircraft ha d spiralled. I explained that I ,made the
PAN call because I had entered cloud , well
below lowest safe altitude, as a non-ins trument
rated pilot and that I had not lost control
altogether .
They then persisted by saying that I should not
make any steep turns and that I should make a
flapless landing at my destination. I asked
where that was to be and there w as a long
silence before being told either Port Macquarie
or Coffs Harbour.
I was given radar headings for PMQ and was
told that if I saw a hole large enough to let
down through it a nd land at PMQ. I thought
there would be no chance of that. Then other
traffic was saying that I didn't h ave enough
fuel to get to Coffs! Yet I had 160 minutes
r ema ining.
The first hole that I saw in the cloud all the
way from Scone was right over the top of Port
Macqua rie - not the tow nship, just the aerodrome - and as we descended the hole closed
over again. Another aircraft noticed t his as well.
We landed safely at PMQ.
The reason for the FS concern about possible
structural damage to the aircraft, was because
in the PAN call, the pilot said that he was out
of control and that he had been in cloud. Talk
about the lucky country D
Aviation Safety Digest
137
Aviation winter
weather
Bureau of Meteorology
· INTER FLYING requires a special
'weather eye', even in the tropics where
_
there are traps for the unwary pilot. This
article discusses separately winter weather conditions in southern Australia, and northern
Australia, with additional comments on northern Queensland. It provides a broad overview
only and does not take into account ' local
weather', which is usually strongly influenced
by small scale topography.
~
Southern Australia
At this time of year southern Australia is
usually under the influence of the westerlies
and t heir associated cold fronts, or a stabilising
airmass w hich often forms after the cold front.
Adverse condit ion s are relatively frequent on
winter mornings in the highlands and valleys of
southeastern Australia and the WA Goldfields
area. They are also prevalent at locations fairly
close to the coast (eg Richmond NSW, Sale, Mt
Gambier).
Kalgoorlie
•
8
Woomera
Tamwort h
s.
4 •
1
1
Mildura
1
10.
2
Adelaide
10
1
% FREQUENCY OF
4/ 6 CLOUD, BASE <1000FT
OR VISIB ILITY< 5KM
AT LOCATIONS IN JULY
TOP FIGURE: 9 AM
LOWER FIGUR E: 3 PM
K~glse~
3
•
1
La nceston
13
5
The typical westerly flows often create mountain waves, but the incidence in any location is
dependent on the orientation of the mountain
range and t he wind direction . These can occur
in higher latitudes in any month, but ar e more
likely over SE Queensland in late winter and
early spring.
The cold fronts usually bring w it h t hem
reduced visibility in precipitation and lowered
cloud bases. Over the southwest corner of WA a
particularly vigorous cold front may produce
thunderstorm activity either along the cold
front or in the cold southerly air that follows
the frontal passage. In the wake of the frontal
p assage, clearing skies and moderating winds
lead to favourable condit ions for fog. Inland,
these fogs may begin the early evening an d in
particularly dense cases, can last until midday.
Over the highlands and slopes of south -eastern
Australia, and locations relatively close to the
coast, areas of radiation fog frequently form
overnight in any calm cloudless conditions,
without the prior passage of a cold front.
The t ypical winter flow patterns may be interrupted at times by intense low pressure systems
forming off the east coast of A ustralia. Ad verse
conditions occur where the onshore str eam
crosses the coast and on t he windward side of
the ranges. Deep layered cloud with a very low
base and moderate to he avy rain may persist
for up to several days, clearing when the ' low'
moves out to sea.
One particularly bad weather system is often
referred to a s the 'northwest cloud band'. This
is frequently first apparent to the northwest of
t he continent and extends for several thousand
kilometres, typically towards the east-southeast. The cloud appea rs to form when warm,
moist tropical air moves poleward and ris es
rapidly . Usually light rain falls init ially and as
the intensit y increases, the cloud base lowers ,
and the v is ibility deteriorates. This system represents very bad flying conditions because:
• The cloud cover extends for thousands of
square kilometres.
• The cloud is often unbroken from the surface
to 20,000 ft. Once in the cloud in a light aircraft there is little opportunity for escape.
• Below minima conditions may persist for
many hours or even days. This is in contrast
t o most other weather systems where t he
minima generally improve or at least
fluct uate.
The northwest cloud band may occur in any
month, but is most evident in winter.
�Aviation Safety Digest
137
Aviation Safety Digest
137
Northern Australia
Flying conditions in northern Australia in winter are usually good. However there are a few
aspects which must be taken into consideration
when planning a flight.
• Poor visibility
Smoke and haze frequently create
nav igational difficulties for VFR pilots , particularly if they are unfamiliar with the area.
Fires are prevalent at this time and their
smoke is widespread below the level of the
temperature inversion, which generally varies
in height from approximately 6-8000 ft in the
north to about 10 OOO ft at the latitude of
Alice Springs. The inversion traps the smoke
below its level by acting as a convective 'lid'
on air rising from below. Horizontal and angular visibility in areas of smoke is commonly
less than 10 km and quite often as low as 2 km.
Navigation in remote areas becomes difficult
when normally well defined la ndmarks may
not be recognised if visibility is poor, and
careful attention is not given to maintenance
of the planned track. Quite often an aircraft
may be out of range of radio navigation aids,
so track keeping and time keeping between
known points assumes gr eat importance when
flying in smoky conditions. Fly ing below t he
invers ion level is sometimes uncomfortable
due to thermal and mechanical turbulence.
During the dry season in the tropics, the prevailing easterly wind regime at lower levels
can be quite strong and will cause mecha nical
turbulence in areas, as well as being a hindrance to accurate track-keeping. The cumulative pressures of long distance flights under
su ch conditions can seriously affect a pilot's
judgment.
The alternative is to fly above the inversion
where horizontal visibility is good and, quite
often, the wind is lighter, or from a different
direction. Flying above the inversion is much
more comfortable, and gives greater effective
range to navigation aids, but vertical and
angular visibility through smoke may be
worse.
• Low level 'jet'
A strong low level jet frequently forms in the
tropical inland in the early morning in winter.
While surface w inds may be calm, winds of
up to 50 knots (although more usually in the
order 25 knots) can be experienced in the
lowest 3 OOO ft. The associated strong windshears are particularly hazardous for low
level operations.
• Cloud and weather conditions in north
Queensland
In winter the southeast trade winds blowing
onto the north Queensland coast have traversed a large body of water and contain considerable moisture. Resultant cumulus cloud is
limited in vertical extent by the trade wind
inversion and shower activity is usually confined to maritime areas (wit h a maximum
activity pre-dawn) and exposed coastal areas
on the windward s ide of t he Great Dividing
Range. Cloud and showers may persist
throughout t he day on the higher peaks, but
maximum activity occurs before midday and
generally earlier. The cloud and showers may,
on occasions, be organised in lines or 'streets'
inclined at a slight angle to the flow . On
occasions a 'surge' of increasing SE w ind progresses northwards with enhanced shower
activity in the surge region. In general, the
stronger the wind, the further inland shower
activity will be found.
The proximity of north Queensland to the sea
and usual onshore winds results in the
reasonably common occurrence of coastal fog.
The chances of fog are enhanced if precipitation has occurred in the previous 36 hours.
Most fogs develop in the early morning, and
generally clear by 8 am in Cape York Peninsula and 9 am further south. Longer lasting
sea fog occasionally occurs, particularly in
the Whitsunday / Mackay area .
Mechanical turbulence may be induced as a
strong SE stream crosses the coastal and highlands region of north Queensland D
FINAL
APPROACH?
Fences are
cheap
Rob Black is the National Secretary of the Sport Aircraft
Association of Australia and has kindly agreed to allow me
to reproduce this article which appeared in their magazine, 'AIRSPORT'.
I WAS ONCE informed by a grey haired mem0ber of the Ancient Order of Aviators that
• there are two kind of pilots: those who have
bent an aeroplane and those who are going to.
That being the case, you should have reason to
believe that if you were unfortunate enough to
suffer the ignominy of bending your favourite
aeroplane then you could expect to be secure
from further embarassment for at least a decade or so . After all 'Murphy', w hose laws are
well k nown, states 'You should believe in something.' I believe I'll h ave another drink.
Yes it was all true, n ot one broken aircraft but
two, and all in the space of 17 days, not quite a
National record but close.
Barry Coutts, one of those fortunate enthusiasts whose assets include a home complete with
airstrip, had organised a fly-in, fun type day
and had threatened physical violence if I failed
to attend with the Midget Mustang . A free sausage from the proposed barbeque was also promised , so the decision was taken to attend. Also,
the navigation skills r equired for the 25 mile
trip were not considered overly demanding,
regardless of t he fact that the Murray River
fails to flow past the property.
I arrived at Barry's to find a reasonable crowd
had gathered and were awaiting all types of
aircraft. The landing strip was east-west w ith
2400 ft between the fences, a gap cut t hrough
massive Cypress trees at the eastern end a nd
power lines at the western - and just to add to
the confusion, there was a really vicious windshear accompanied by an equally savage
crosswind. However , a satisfyingly smooth
landing was negotiated, accompanied by a
straight roll-out in front of the crowd. Maybe
things weren't so bad after all.
I set up camp with other pilots amidst lots of
laughter as we cheered later arriving pilots,
desperate for survival as they negotiated their
way through t he tiny gap in the Cypress, meeting the windshear, applying big heaps of power
and lots of control input - all to the plaudits
of the growing crowd most of whose critical
assessment was honed by a 'tinnie' or two. All
great fun!!
A variety of aircraft were in attendance,
ultralights, homebuilts, antiques and Barry had
even hired a helicopter for the day. Plus of
course, there was the usual array of Cessnas
and Pipers. The vintage car brigade also
attended to provide further interest.
However , time, unlike the wind, quickly passed
and my good lady had warned that I must be
home by 6.30 pm as we were dining-out w ith
relatives. Fearful of the wind which had now
become a southerly of 15 knots or so, I delayed
my departure for as long as possible - being
ever mindful of the orders issued by She-whomust-be-obeyed. 'Don't be late as we are going
out to tea.' (To the 'in-laws', of course.)
Most of the taildraggers, or at least those with
engines rotating in a direction other t han th at
of a Gypsy Major, elected to take off with the
crosswind from the right. This certainly makes
the task of keeping the little Mustang straight,
that much easier - something to do with the
'P' factor - although there was some possibility of having to cop a slight downwind
component.
Preflight done and departure imminent, engine
run-up gives a dr op of 150 rpm on the right
magneto. I run it up to 1900, lean to minimum
and recheck. Everything now appears normal. I
check all clear and away we go, concentrating
on staying s traight. Everything is in the green
and we are air borne slightly prematurely . Surprise! The little bird settles back on the turf
and immediately drifts to the left of the runway. I pull back the stick and for ce the
machine into the ai r , thinking dark thoughts
about win dshear and possible downwind gusts.
About two thirds of the way down t he strip t he
penny is starting to drop t hat the acceleration
is remarkable by its absence. The engine
appears smooth enough but it's down on power.
A ~uick check. Did I leave off one of the mag
switches? No. Hell! there's not much strip left
a nd I have those Cypress nicely lined up what a predicament!! Even I know that to safely
keep an aircraft flying, you must have at least
two of the following commodities: Airspeed,
Altit ude, Brains. All three are in perilously
short supply, plus I have the t rees to contend
with. By pedalling furiously I manage to slip by
the t rees, thinking, 'the worst is over, I should
be right from here' . Wrong! An altitude of 20
feet and an airspeed a shade over stalling, combined with with an ailing engine and a pilot
short on grey matter, gets us back t o the aforement ioned rules of aerodyn amics, not to mention Mr Murphy's.
�Aviation Safety Digest
137
Aviation Safety Digest
137
Still, there's 3050 feet of bitumen. You could
almost land a Jumbo here compared to Tyabb. I
use up about one third of the available runway
before getting the wheels planted, consider
going round and dismiss the idea as absurd. I
raise the flaps and apply the brakes. By golly,
we are eating up the strip! It might be a bit
tight, maximum braking and we are slowing
rapidly but the once adequate runway is now
much shorter and the brakes appear to be
fading. I leave the bitumen, pass onto the grass
overrun and am still doing about 15 mph. I
elect to turn rapidly to the right rather than
take on the fence. Just when I reckon I have
gotten away with things, the left undercarriage
retracts and I am again enveloped in the sounds
of tortured metal as the aircraft sinks to the grass.
On vacating the aircraft I can't believe it. The
wind is howling down the strip at 12-15 knots.
The aircraft appears superficially at least, to
have suffered no damage other than to the ADF
aerials and amazingly, the LH propeller had
stopped in the horizontal position and not
struck the ground.
Both airframe and engine decide enough
aviating has been done for the day, and both,
largely unassisted by the ashen-faced pilot,
make a nice landing in the paddock - 150
metres past the end of the runway, but only 15
metres short of a robust four-strand electric
fence. My world is encompassed by showers of
splintering posts and propeller, tearing metal,
twanging wires a nd tortured fibreglass. A
cacaphony of sound, then silence.
I realise all is not well with the world and I
would be better placed outside the confines of
the cockpit. So I calmly switch off the fuel and
electrics and vacate the scene. (If you believe
this you must still believe in the Tooth Fairy).
Three seconds later, I am clear. A further two
seconds and Barry is 15 metres away in the
hovering Bell 47, having witnessed the whole
disaster.
The accident investigation the next day, reveals
little wrong. However, an engine strip shows a
faulty RH magneto, which just stops magneting
or whatever magnetos are supposed to do. A
throwaway Slick which should have been
thrown away earlier, is the diagnosis.
However, life must go on. Sure, my little Mustang is badly damaged but at least it is repairable. My ego is dented but I can live with that.
Look on the bright side. I have escaped a serious accident without a scratch and I have
avoided dinner with the in-laws. Yeah, I really
am lucky and the insurance will more than
cover the cost of repairs.
Although I am so lucky, I am shortly afterwards struck down by some evil virus. I feel
absolutely rotten and to make matters worse,
have to return to work early. Work is full of
urgent unplanned requirements, but things are
on the up. A customer from Morwell has a new
job and I decide a short flight is in order to discuss his needs - although I am still suffering
the effects of the virus.
Home for a quick cup of tea, over to the airstrip, fire-up the Seneca and up to the 'Valley'.
At Tyabb, it is blowing a westerly of about five
knots max. The smoke-stacks at the Loy Yang
power station show little apparent wind and it
seems as if 03 is the runway to use. I fly over
the top of the airfield for a confirming look at
the primary windsock. There it is, etched forever in my memory, situated on a bitumen
circle with a freshly-painted white line around
the perimeter, but as to the sock, I cannot see it
at all. Has it been dismantled or is it just lying
limp? I determine that it's playing dead and I
fail to pick up the secondary sock. I broadcast
my intentions to join crosswind for 03 and join
the circuit, failing to even consider another look
at the windsock. Downwind checks completed, I
turn onto base.
'PUF' checks out of the way, what a dreadful
approach. In a last-second flurry of cockpit
activity, the runway is lined-up and airspeed is
back to 82 knots. The aircraft is waffling
around a little and I am still a little higher than
anticipated. Is that wind playing tricks like
everything else at LTV?
The airfield appears deserted as I make the
short trip to the clubhouse. 'How could I be so
stupid' - there is no excuse. I am not unduly
shaken - just unbelievably angry and full of
self-doubt . I contemplate my future in what had
been an all encompassing passion for the last 13
years. 'What an unbelievably stupid thing to
do!', keeps running through my mind. How can
a lunatic like this be let loose on the
population?
After arriving at the deserted clubhouse, I ring
the Department and inform them of my misdemeanour. Surprisingly, they are most sympathetic. They are not such a bad mob after all.
John Brown and John Williss arrive and
efficiently organise all that is required.
I am given a ride home with a relative to find a
shocked wife. She knows everything already.
John Sonneveld, my personal accident investigator, has already been on the phone. I ring
John back and arrange to return to LTV the following day. It really is the last place on the
face of the earth that I wish to visit. John is
marvellous and I am back home at noon, but
how can I ring Jeff Butler of the Aviation Pool
Insurance? It takes an hour to pluck up the
courage. He is incredulous at first but sympathetic and helpful, before threatening to disclose
the facts of my folly to aviation partners and
close friends. However, on reflection he realises
that I just might commit suicide or more likely,
some equally violent act upon him and remains
silent.
I am totally depressed and refuse to answer the
phone or see my friends. My wife, for the first
time in 25 years, really feels for me - for
which I am eternally grateful. I feel mentally
scarred and ashamed. The once joyous. sound of
an aircraft engine brings mental pain. It is obvious that I shall never go near another aeroplane
and the SAAA will have to find another
Secretary.
However, time passes. A few days away from it
all works wonders and I realise members and
friends are genuinely concerned about my misfortune. I eventually find myself picking-up an
old aviation magazine from force of habit and
even watching Peter Bernardi on climb-out from
Tyabb in his magnificent old Ryan.
Friends materialise with all sorts of odd
pretentions. Could I accompany them on a short
trip to Coolangatta? - and they somehow contrive situations where I just have no option but
to ferry a Seneca on a short trip. Before I know
it, I am once again ensnared in the sometirneswonderful, world of aviation.
I doubt if anyone has ever checked the landing
charts of their aircraft to ascertain how much
extra distance is required - should you land as
I did, with 12 knots of downwind component. In
the case of the Seneca, it is an additional 130
percent. A rough rule of thumb is an extra 10
percent distance for each knot of downwind.
So please check that you are landing upwind
even if it is only a couple of knots, particularly
if your strip is marginal. Just because the wind
was from a certain direction on takeoff, does
not mean it will still be the same 15 minutes later.
Oh yes, the title, 'Fences are cheap'. I had to
pay for the damage - four posts and about
100 metres of wire - a total cost of $47.00 and
I paid it personally. Who would have had the
nerve to claim it on the Pool?
[When Rob agreed to the publication of this
article in the Digest, he asked me to re-iterate
two points:
• It was not traumatic to put in a report to
BAS/ - in fact the positive, supportive treatment that Rob received went a long way to
getting him back into the air. He said he
almost gave the game away.
• If you feel for any reason that perhaps you
shouldn't be going flying that day, then don't
go. Stay at home and wait for a better
time.] D
�Aviation Safetv Digest
137
Aviation Safety Digest
137
211:1
Dear Sir,
With reference to ASD 135, I was interested in
Steve Tizzard's article on ALA's.
I concur with everything that Steve said and
would like to add one other point, if I may.
As a tug pilot I am often called upon to retrieve
gliders that have landed in some paddock which
in some cases may not even comply with even
the broadest interpretation of what constitutes
an 'ALA'.
Apart from all the other points that Steve
made, the length of the strip is of prime
importance.
The selection run can be indeed done at the normal approach speed. However, if safety is not
compromised, another selection run can be
made at 60 knots. At 60 knots you are travelling at about 100 ft/sec. By counting 'one thousand, two thousand' etc. as you pass along the
length of the landing areas you can obtain a
fairly accurate idea of the length of the strip. If
60 knots is not possible ( eg a fully loaded
C-210) then the speed can be 120 knots and the
number of seconds is multiplied by two to give
you the length.
Naturally, the faster you go the less accurate
the measurement becomes. I feel, however, that
most two and four seat, single-engine aircraft
could fly at 60 knots fully loaded without any
problem.
I hope that some pilots will find this hint helpful. It is at least better than a guess and it also
helps you verify the length that may have been
conveyed to you by a farmer or anyone else.
It seems to have worked in the gliding fraternity for quite some time.
Yours faithfully,
William Comerford
Thanks Bill,
Your technique is a useful one. I think 60 knots
is a little slow for some aircraft especially near
the ground in windy conditions. What can be
done in these instances is to work out for your
particular aircraJt type, the minimum elapsed
time for a run which represents a safe landing
and take-off distance at a speed that is comfortable for you. For example in a Warrior PA28161 you may choose to fly the run at 80 knots
- in which case an elapsed time of say 20 seconds corresponds to a strip length of about
2700 feet, which is reasonable for this aircraft.
Don't forget, too, that we are metricated - the
Australian Supplement to the flight manual
gives performance criteria in metres. Using
your example, at 60 knots the aircraft travels
100 feet each second and that is close enough
for all practical purposes, to 30 metres per second. A 20 second run at 60 knots therefore corresponds to a distance of600 metres, or 2000 feet.
An important point though - the timed run
principle applies to a 'groundspeed' of 60 or 80
knots or whatever. It is invalidated in any sort
of strong wind. In this case you should do two
timed runs in opposite directions and average
the two figures - this will compensate for the
effect of the wind.
Also I would caution against relying on counting the time unless you have practised the technique - ask any skydiver about the' differing
length of 'seconds'. Perhaps it would be better
to use a stopwatch or the second hand of your
wristwatch, taking care not to stare at it to the
detriment of flying the aircraft.
Dear Sir,
I note in the 'AIRFLOW' column in ASD136, a
letter concerning the use of a cellular telephone
in an aircraft. The use of such devices in aircraft has been banned by Telecom and they
have asked that we advise pilots of the reasons
for this ban. The gist of their concerns are as
follows:
'Telecom has a policy that mobile phones are
not now permitted to be installed or used
within aircraft. There are two main reasons for
this policy .
Firstly, Telecom is concerned about the possible
inteference from RF emission to aircraft navigation systems and other aids essential to safe
flight. This is also a major concern overseas
where the FAA and the US Federal Communications Cornmisssion have banned the use of
mobile phones in aircraft because of the risk of
interference to comrns and nav equipment.
Another major problem is the significant interference to the mobile telephone network itself
from airborne mobile phone users. Telecorn's
latest mobile telephone network (MobileNet)
which has been specifically designed for landbased mobile use only, utilises the cellular radio
concept where identical frequencies are re-used
in non-adjacent cells within the same geographic area. The extended propagation path
available from an airborne phone results in significant interference to the network as multiple
channels can be simultaneously selected. This
interference includes the disconnection of established calls, crossed lines and numerous other
problems.
The term mobile phone includes not only the
traditional car phone but transportable and
hand-held models which are available from
Telecom and other suppliers.'
As well as endorsing the Telecom policy, the
Department has been liaising with aircraft operators for the control of electonic devices in aircraft. Of particular note is the fact that it is the
responsibility of the pilot-in-command to supervise the carriage of such items by their
passengers.
Peter Routledge
Department of Transport and Communications
Dear Sir,
My son flies BN-2 Islanders in Vanuatu. He
recently experienced an emergency on a flight
from Sara which has a 450 metre grass strip
with a 500 foot cliff at each end.
I thought the enclosed account may be of value
to your readers.
'Dear Dad,
Thanks for your letter of the 25th which I
received this morning. Amazing!
I am presently a quarter of the way to Fiji having departed Vila at 1.07 pm. Yes, risking my
life again! I'm at 10 OOO feet and it's 10 degrees
celsius. I have a life raft on the seat beside me
and the engine that failed last week is in the
back. The engine will be overhauled and the
aircraft will have a major inspection.
You asked me for the details of the emergency
so here they are. Last Tuesday, (last week)
Tom, the new pilot (who went to Churchie) and
I were flying the normal scheduled route from
Santo to the islands. Tom had almost got his
endorsement on the aircraft so I let him do
most of the flying. However, I did the flying in
and out of Sara - the 450 m strip you may
remember. I did a lovely landing and didn't
even need to use the brakes. We took off with a
full load - ten passengers - so 12 persons on
board, at a weight of 2730 kg, nearly 270 kg
under the maximum. We got airborne okay and
normally you turn left into wind to increase the
angle of climb and to avoid the hills. I had just
done that and hadn't touched the throttles
when the propellers started going out of synch
and the right engine manifold pressure dropped
rapidly, followed by the rprn. I looked at the oil
pressure gauge and there was no pressure. We
were only 200 feet above the runway which is
at 500 feet elevation. Over the water we had
700 feet altitude and we managed to reach 800
feet before I feathered the propeller. We had
lost oil but we couldn't see any on the engine
cowling. I purposely ran the engine until it
almost stopped before I feathered it so I knew
it had had it. The aircraft maintained height
fairly well for about two minutes with the left
engine at maximum continuous power but the
left engine has always been a dog and it began
to overheat. Then its performance deteriorated
and we started going down.
By now I had the aircraft well set up and
trimmed at the correct speed, angle of bank etc.
We were heading to Longana which is about 16
miles away over water. I couldn't risk landing
with one engine at Sara - it's hard enough
with two engines and if I got a downdraught on
final, I could have flown into the cliff at the
threshold. So we were descending at 50-100 feet
per minute and only doing 65 knots . At that
rate we wouldn't make it so I went to full
power on the left engine. It was really hot and I
just hoped that it would keep going. We were at
200 feet over the water with about a mile to go
to the island and I thought we may have to
ditch. That meant Torn and I probably would
have been killed straight away. With fixed
undercarriage and a high wing this is a very
bad aeroplane to have to ditch.
Anyway Torn got all of the passengers to put on
their life jackets so now they really knew something was wrong. Now we were at 150 feet and
I thought we might make it to the strip . Both
Tom and I were really worried. I was going to
send him down to the rear of the plane to
throw out some of the cargo but I then realized
that we were flying right on the stall. I pushed
the stall warning circuit breaker in (I normally
leave it pulled out because it annoys me and
the passengers when it goes off on landing) and
the warning blared. If he had gone to the back,
the CG would have changed and we would
probably have stalled.
We strapped ourselves in tightly in case we hit
the trees and I did a very wide circuit to the
runway which I couldn't see anyway because
we were so low. Torn almost had a fit when he
saw where the runway was. We were a long
way out so all that I could do was very gentle
turns so as not to lose any more height. We
skimmed the tree-tops and maintained height
probably because of the heat rising from the
surface. We landed safely and I was shaking
like a leaf when I got out of the aircraft. I
thought we were going to die. I've often
thought about how I would react to that kind of
situation. I was determined to get the aircraft
to the runway. We flew so close to the stall
that the aircraft buffetted a couple of times.'
�~11
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17881988
ASD138
SPRING 1988
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Aviation Safety Digest
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Aviation Safety Digest, number 137 (Winter, 1988)
Identifier
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137
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A point or period of time associated with an event in the lifecycle of the resource
1988
-
https://collections.heritageoftheair.org.au/files/original/26177567710a0440fee7f355c8b4691f
3f6e75da3f999ed53f996531e96820f6
PDF Text
Text
~--.Bottle*
l)<)ttles <)r
thr<)ttles?
t
hours. I
to Throttle
l)<)ttles C)r
thr<)ttles?
l)<)ttles <)r
throttles?
It is not possible to
establish a hard-and-fast rule
regarding drinking alcohol
and flying.
Have at least 8 hours
,
sleep.
· (f !/
Sleep is the only cure for ~ {
a hangover. If you don't
, "~\.
feel rested ... don't fly.
If you can't remember .. '-:.(.:'
how you got home, or
any other part of the
night before ... stay
in bed. If you have a
headache . . . don't fly.
If you feel sick or
dizzy ... don't fly.
There's no pleasure
in flying with a hangover. Have a sensible
breakfast. If you can't
face breakfast. .. don't
even consider facing
an aeroplane ...
certainly not one with
passengers.
·Y!))
The eight
o'clock rule.
To auoid aeronautical misery:
As a general rule, finish your
drinking by 8 o'clock. Have a
decent meal if you haven't
already done so. Go for a walk,
read a book, watch TV or go to
bed. Drink water, fruit juice,
vegetable juice or soup.
Lots of it!
In the morning get some fresh
air, a little exercise,
have a shower
. and drink more
juice or water ...
not tea or coffee.
Have a light
breakfast. Spend
the day doublechecking everything.
ASD 136
AUTUMN 1988
I
Australia
1788-1988
• 7 so mls beer
Designed IJy Les ley Gordon
�Aviation Safety Digest is prepared by the
Department of Transport and Communications
and is published by the Australian Government
Publishing Service. It is distributed lo Australian licence holders (except student pilots),
registered aircraft owners and certain other
persons and organisations having an
operational interest in safety within the Australian civil aviation environment.
Contents
Gone with the wind
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
Crosswind landings are still a challenge and this article
from an earlier Digest has some valuable advice.
The Publications Distribution Officer (EPSD)
Department of Transport and Communications
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
It's that time again
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Peeper keepers
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Due to reader interest this article examines presbyopia
and the choices in lenses that may best suit a pilot.
1" The low-down on fast jets
This article was contributed by the RAAF and explains
F111 operations at low altitudes and how to minimise
any risk of collision.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Department. The articles are intended to
serve as a basis for discussion and even
argument in an effort lo identify and resolve
problem areas and potentially hazardous
situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
1
Eyes in the back of your head
A humorous tale with a serious message about flying in
the Bankstown area.
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
I honestly couldn't say that flying was safer than road travel as I
wasn't sure of the statistics in terms of number of passsengers,
number of vehicles, distances travelled, probability of accidents,
probability of serious injury or death as a result , probability of
breakdown or mechanical failure, probability of injury as a result
of the failure, vulnerability to weather and the probability of a
resulting accident or injury, reliability of safe and timely arrival,
and of course, relative costs versus speed, comfort and ease of
travel.
As a pilot, I felt intuitively that flying was safer. I am more comfortable in an aircraft than in a motor vehicle. I know and understand
the aircraft and its environment. I feel that the likelihood of being
killed or injured on the road is greater as I am more vu lnerable to
the mistakes of others. At least in an aircraft, if I am killed, it will
probably be my own fault .
And that was the crux of it. Safety depended on who was
'driving'. I am a reluctant passenger in an aircraft if I don't personally know the pilot and know his or her attitudes, temperament,
behaviour under stress and ability. In the case of RPT travel I rely
on the selection, the training and the close supervision of
aircrews associated with those operations - although I still sit up
in response to the throttles being cycled on final, larger than normal attitude changes and unexpected or unusual noises.
But how do you tell?
• By his dress?
Covers
Front. A touch of nostalgia. Perhaps the
most successful training aircraft of all
time, the Tiger Moth is still a joy to fly on a nice day.
Geoff Aitken's Tiger at Prairie, 1987.
Photo by David Robson.
NIKON F Kodacolor Gold
Back. The most serious drug problem in
the aviation community? Coming to grips
with the 'social' use of alcohol can
require considerable self-discipline. When
have we had enough? Each of us must
decide for ourselves and be responsible
for our own condition. It may not be easy.
Poster design by Lesley Gordon
• By her manner?
• By his confidence?
• By the thoroughness of her preparation?
• By the cleanliness of the aircraft?
• By intuition?
1
A measure of success
The final in our series on landings, this article considers
the performance aspects.
Reader contributions and correspondence
should be addressed to:
©Commonwealth of Australia 1986
ISSN 0045-1207
R85/979(8) Cat. No. 87 1577 8
I
was recently asked for advice on the best means of travel for
a family trip. Would I recommend a light aircraft? Was it sate?
_ How did it compare with road travel?
However, I would rather drive than fly as a passenger in an aircraft with a pilot that I did not know. My advice to my friends was
to travel by air - if they could afford delays due to weather and
only to fly with a pilot that was sate!
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
The Editor,
Aviation Safety Digest
Department of Transport and Communications
G.P.O. Box 597,
Canberra, A.C.T. 2601, AUSTRALIA
j
It all depends on the pilot
I thought about it for some time as the people asking were close
friends.
Water in the air or water in the fuel - both are significant problems and in the Southern states, autumn and
spring are high risk periods.
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
Editorial
2
Traps for young players
Our regular look at possible pitfalls in flying.
The advantage that we have as pilots, is that we know the pilot
- don't we? We know how we will react under stress - don't
we? We know that we won 't skimp on preparation - don't we?
We know that we won't take short cuts which may increase risks
- don't we? We know that everything necessary for a safe flight
has been checked, personally - don't we ? We know that we
wont be pressured into risky situations without having a way out
- don't we? We know when our personal performance is not up
to par and we make allowances for it - don't we?
With us, flying is much safer than driving -
isn't it?
Editor:
Editorial Assistant:
Graphic Design:
Photographs:
2
AIRFLOW
The readers' column.
DAVID ROBSON
Editor
P4
p 8, 21
p 13
p 17, 19
Diagrams: P 5, 9, 10,
11, 14
Cartoon:
David Robson
Karen Hutchison
Lesley Gordon
Malcolm Lloyd
BAS/
RAAF
David Robson
adapted by Soussanith Nokham
and Peter Garfield
Gapinski
�Aviation Safety Digest
136
Encountering turbulence generated by the gusty
crosswind conditions on final approach, the
pilot maintained a speed of at least 75 knots
until he had crossed the threshold. After
rounding out, however, the aircraft floated for
over 300 metres before touching down on the
mainwheels. The nosewheel quickly dropped to
the ground and still at high speed the aircraft
skipped three or four times before settling onto
the ground. Almost immediately the nosewheel
began to oscillate and the aircraft swung rapidly to starboard under the influence of the
crosswind until it was heading towards the
edge of the runway. The pilot attempted to
regain directional control but the aircraft left
the sealed surface and headed directly towards
two cone markers on the boundary of the flight
strip. Though he was now pressing hard on the
left rudder pedal, the pilot was unable to check
the swing and the aircraft smashed through the
markers into a bank of soft sand. The nosewheel broke off and the aircraft came to an
abrupt halt on its nose, extensively damaged.
Gone with
the wind
This article previously appeared in Aviation Safety Digest
number 97.
T
0 MANY PILOTS, even quite experienced
ones, the prospect of a crosswind landing
..::... remains something of a secret fear - somet hing to be ignored most of the t ime in t he
pious hope that if ever they have to make a
'maximum effort', they will be able to cope somehow!
This article encourages p ilots to face this situation, explaining what is involved and enjoining
practices which will enable crosswind difficulties to be accepted with confidence and skill .
Arriving over a country aerodrome, the ownerpilot of a newly restored vintage aircraft estimated fr.om the windsock that the wind was
blowing from the east at about ten knots.
Anticipating that these conditions would produce only a slight crosswind component on the
12-duty strip, the pilot decided to practise
some crosswind landings and carried out a circuit and approach. After touching down, the
aircraft bounced, but when the pilot saw that it
was not drifting, he decided to continue with
the landing and applied power to cushion the
f
descent. But as the aircraft touched down
again, the port wing suddenly lifted and the
aircraft swung rapidly off the strip into a cultivated area in the middle of the aerodrome.
Unable to check the swing, even with full rudder and aileron, the pilot opened the throttle to
go around but, realising the swing had progressed too far, promptly closed it again. As the
aircraft skidded downwind, the port wheel dug
into the soft earth, one of the undercarriage
bracing struts collapsed, and the aircraft
pitched forward onto its nose and overturned,
coming to rest on its back. It was subsequently
determined that at the time of the accident, the
wind was indeed blowing from the east but was
gusting to about 25 knots, producing a crosswind component in excess of the maximum
permitted for the aircraft type.
Admittedly, such aircraft are not easy to
handle in a crosswind and it may seem a little
unfair to select an accident like this as an
example of mismanaging a crosswind landing in
a light aeroplane. However, the Department's
records s how that the sort of problems experienced in this case are by no means confined to
earlier types of aeroplanes and that crosswind
landing accidents are continuing to occur in
many modern light aircraft, despite the
inherent directional stability of their nosewheel
undercarriages.
Typical of these is an accident involving the
pilot of a Cherokee. Arriving over his destination, which had only a single, sealed eastwest runway, the pilot circled the aerodrome
twice while he assessed the wind strength and
planned his approach. As it turned out, the
wind, a southerly of about ten knots, was blowing virtually at right angles to the runway, and
as it did not particularly favour either direction, the pilot eventually decided to land into
the east.
• By heading the aeroplane sufficiently into
w ind to counteract the drift and, with the
wings level, tracking or crabbing along the
intended landing path .
~.Ctt~•,;:t• . ~:t .·1 i '~-,~=~
]J!tl: :l.!
:~ ~ - 1- -~~~·· :'~-. ~-
• By lowering the up-wind wing and, holding
on opposite rudder to stop the t urn, sideslipping the aircraft sufficiently to descend
in line with the landing direction.
Planning ahead
Planning for a cr osswind landing, as with any
other type of landing, should begin well in
advance of the actual approach and touchdown.
Correction for drift in the circuit is quite different to that normally required and allowance for
it mu st be made early to avoid distortion of the
circuit pattern. Special care is needed on the
downwind leg to ensure that the aircraft tracks
par allel to the intended landing path and thus
maintains the correct distance from it. The pilot
also needs to remember that ground speeds on
crosswind and base legs will be different to
those he is used to and he should be prepared
to begin the t urn onto final approach earlier or
later than usual, depending on the wind direct ion, in order to roll out of the turn correctly
lined up with the runway.
The approach
As most pilots w ill recall from their student
days, a good approach makes for a good landin g, and a good approach rar ely follows a poor
circuit. This is especially so in crosswind conditions where any error in assessing drift in the
circuit or on final approach will make judgment
more difficult and only increase the chances of
a poor or misjudged landing.
There are two fundamental methods of compensating for drift du ring an approach to land out
of wind:
Of these two techniques, the crabbed approach
is the more straightforward method of compen·
sating for drift. Once a crab angle sufficient to
cope with the conditions has been established,
the aircraft handling, at least up to the point of
touchdown, is quite straightforward and similar
in a ll other respects to a normal approach.
In the case of the side-slipping technique, however , there are several important considerations
to be taken into account. In many aircraft
types, flight manual requirements prohibit
extended side-slips with low-fuel quantities
because of the danger of uncovering the tank
outlets and causing engine failure from fuel
starvation, a situation which could be
extremely embarrassing at low height! In some
aircraft too, side-slipping with flaps extended
beyond a particular setting is not recommended
because of the possibility of shielding the tail
surfaces from airflow and producing a sudden
nose-down pitch which could be difficult to correct close to the ground.
Yet another and perhaps not quite so obvious
shortcoming of this type of approach is the
possibility of 'running out of control'. In a very
strong crosswind, considerable into-wind aileron
and a correspondingly large rudder deflection
may be necessary. In these circumstances, there
may be insufficient control t ravel r emaining for
the pilot to right the aircraft should an exceptionally strong gust or unexpected t urbulence
cause an upset near the ground.
�1-
Aviation Safety Digest
136
Aviation Safety Digest
136
Touchdown
Dur ing a crosswind landing, the wind force acts
over the entire side area of the aircraft and
tends to push it towards the downwind side of
the runway. This force is proportional to the
square of the crosswind velocity; thus, in a ten
knot crosswind, the side force on the aircraft
would be quadruple that produced by a five
knot wind component. Generally, the centre of
pressure of this crosswind force acts aft of the
centre of rotation (the main undercarriage) so
that a yawing moment which tends to make the
aircraft weathercock into the wind is usually
produced.
Undercarria ges are not designed to withstand
heavy side loads, a fact brought home only too
clear ly by accidents such as those described at
the beginning of this article. It is imperative
therefore that the air craft is not permitted to
contact the ground while drifting and that at
the moment of touchdown it is aligned with th e
runway.
As in the case of the crosswind approach, there
are two basic methods of counteracting drift at
the point of touchdown. Both are simply extensions of the techniques already described. If the
crabbed approach is used, the touchdown technique consists of flaring the aircraft in the normal way, with the drift correction still applied ,
and then as s peed diminishes and the aircraft
begins to settle towards the runway , smoothly
but firmly applying rudder to yaw the aircraft
into line with the landing path just before it
tou ches down. As the aircraft is straightened in
this way, opposite aileron should be used if
necessary to keep the wings level.
Despite the obvious advantages of the cr abbed
approach , this exercise of 'decrabbing' immediate ly before touchdown calls for a very high
degree of skill and judgment. The pilot must
resist the temptation to align the aircraft with
the runway too soon or, though still pointing in
the landing direction, it will quickly commen ce
drifting towards the downwind edge of the runway. Any attempt at this stage to re-align the
aircraft by making a co-ordinated turn into
wind will almost certainly result in it striking
the ground while drifting downwind. Conversely, if the pilot waits too long to straighten
up, the aircraft will touch down at an angle to
the runway, subjecting the undercarriage to the
very loads which the exercise is intended to
avoid. And e ven if the pilot has correctly
judged hi°s height above the runway and he
starts to reduce the crab angle at what he estimates to be the right moment, he may still find
himself in difficulties. Decaying airspeed during
the hold-off might well have reduced rudder
effectiveness to the point that, even with fullpedal defle ction, there may be insufficient control available to yaw the aircraft into line
before the wheels touch the ground.
By contrast with these difficulties, landing off a
side-slipping approach does not requir e such
p recise judgment or t iming. The aircraft is
already aligned with the runway and after
what is virtually a norma l flare and hold-off,
t he a ircraft touch es down without drift on the
upwind mainwheel. The fact that t h e upwind
wing remains lowered also provides some
measure of protection a gainst stron g sideways
gusts.
The combination method
The crosswind landing technique w hich probably gives the greatest degr ee of control without making unnecessarily high dem ands of pilot
skill is the combinat ion crab-slip method . In this
type of approach and landing, the pilot compensates for drift on the approach by c rabbing t he
a ircr aft into wind and holding the drift correction until after the a ircraft is flare q for landing. But as the speed begins to diminish and
before the aircraft starts to settle towards the
ground, the pilot transitions to the slip method
by yawing the aircraft into line with the runway while speed is still s ufficient to maintain
rudder effectiveness. Then, when the aircraft is
tracking straight down the run way, the upwind
wing is lowered smoothly to prevent further
drift and the hold-off continued until the
upwind wheel touches the ground. After t ouchdown, the aircraft is kept straight by using a
combination of rudder and upwind aileron.
Directional control after touchdown
Maintaining directional control after touchdown
in a tailwheel aircraft generally presents no
major difficulty provided a wheel-landing technique is used. The aircraft is held straight
initially by the careful application of rudder
and then judicious use of brakes as the tailwheel is lowered to the runway. Into-wind
a ileron helps pre vent the upwind wing from
rising in a strong gust.
In nose-wheel aircraft, however, there are the
limitations of nosewheel steering to contend
with. A few modern general aviation aircraft
have fully castering, non-steer able nosewheels
but the great majority have some form of steering system. On some types, the st eering is not
direct but arranged through a spring linkage so
that when the wheel is off the gr ound and the
strut is fully extended, the wheel automat ically
aligns itself with the centre-line of the aircraft .
But on most others, the nosewheel is coupled to
the rudder pedals by a direct-act ing linkage so
that the wheel turns whenever rudder is
applied . It is this arrangement which can lead
to handling problems in crosswind landings. For
no matter which crosswind technique is used)
rudder application (sometimes full deflection) is
necessary to align the aircraft with the runway.
If the nosewheel is allowed to contact the
ground with rudder still applied, the aircraft
will immediately swing in the direction in
which the wh eel is turned regardless of the
wind direction.
A deliberate effort is therefore required to cent ra lise the rudder pedals befor e the nosewheel
tou ches down to avoid the onset of an uncont rolled swing and ground loop. Pilots must a lso
bear in mind that a simila r manoeuvre could
result if, in an endeavour to hold the aircraft
on t he ground, too much forwar d elevator control is applied at too high a speed, thus transferring most of the aircraft's weight to the
nosewheel. In some instances, this could lift th e
mainwheels clear of the run way altogether.
General technique
As a gener al rule, it is p refe ra ble to carry out
powered approaches in crosswind conditions.
The use of power helps a pilot regulate the rate
of descent ov er a very wide range to compensate for v arying wind strengths. It also r esults
in a smaller change in attitude during the landing fla re compared with t hat for a full-glide
approach. Furthermore, whenever the wind is
strong and gusty, no matter from which direct ion it is blowing, it is always desirable to use a
slightly higher approach speed to p rovide a
greater measure of contr ol and a higher mar gin
above t he stalling speed. On the other hand, the
use of too high a speed in a crosswind can lead
to many kinds of problems. For instance, as the
crosswind angle increases, the headwind
component decreases until, with a wind blowing
at right angles to the ru nway, the headwind
component is reduced to zero. An excessively
high approach speed in these circumstances, no
matter how hard t he wind is actually blowing,
will result not only in a significant in crease in
the landing distance but also in a much higher
ground speed at touchdown, which could well
lead to handling difficulties in some types of
nosewheel aircraft.
Some pilots, in an attemp t to offset the
crosswind effect, aim to land near the
downwind edge of the runway, apparently
reasoning that by allowing themselves this
additional manoeuvring space, th ey would have
more chance of recovering control should the
aircraft start to weathercock to into-wind after
touching down. These pilots, however, overlook
the fact that in this situation it would not take
an especially strong gust to blow th e aircraft
off the runway altogeth er , possibly into a rough
or otherwise unserviceable area. Others, thinking along slightly different lines, plan t heir
approach for the up-wind side of the runway t o
provide an additional margin should t he aircraft begin to drift downwind before the wheels
contact the ground. This t echnique has an
inbuilt snag in that if the aircraft d id weath ercock after touchdown, the pilot might not h ave
room to regain directional control before it runs
off the runway. All things considered, it is far
better to adhere to established techniques and
to aim to touch down about the normal distance
in from the threshold as near as possible to the
centre line.
Pilots should at all times guard against the
error of touching down first on the downwind
wheel. This raises the upwind wing, presenting
a large surface area to the wind. Not only does
this increase the chance of the aircraft being
blown laterally off the strip but it can also
induce a rolling motion which, once developed,
can be very difficult to correct. A similar effect
can be produced if the aircraft touches down
near the downwind edge of a heavily cambered
surface.
Practice
Pilots should be capable of handling a variety
of crosswind conditions competently and safely.
In addition to operations at major airports
where procedures frequently call for landings
out of wind, they may be confronted from time
to time with unexpected situations such as a
tempora ry obstruction on an into-wind runway
of an in-flight diversion to an aerodrome where
the win d may be blowing strongly at an an gle
to the only available strip.
As precise judgment is required to estimate
height and drift angle in crosswind conditions,
and a high degree of co-ordination is necessary
to correctly align the aircraft with the touchdown direction, proficiency in crosswind landings is a skill that can only be maintain ed by
regular pr actice. Traffic at busy secon dary airports does not always permit operations contrary to th e nor mal circuit pattern but
frequently, even on the duty runway, there is a
small crosswind component which sh ould be
properly allowed for. Pilots should use these
opportunities to p ractise and perfect their
crosswind landing technique rath er t han simply
ignoring this factor and t rusting the aircraft's
normally forgiving tricycle undercarriage to
cope with side loads a nd sort out the directional stability problems
Maximum crosswin d components a re normally
specified in the aircraft flight manu al. Th ese
values are generally based on tests carr ied out
by the manufacturer and represent th e maximum crosswind values at which the air craft has
been demonstrated (in dry conditions) to possess satisfactor y handling qualities. Such demonstrations a re usually conducted by test pilots
and the results may well be regarded as being a
limitat ion for the type. Pilots should therefore
exercise discr etion in stron g crosswind conditions to ensure that th e operations are confined to cr osswinds w ithin their own
capabilities and to accept that this may be significantly less than the crosswind component
r eferred to in the flight manu al 0
�Aviation Safety Digest
136
Aviation Safety Digest
136
It's that time
•
again
HE PILOT held a RPPL and had a total of
52 hours experience. He was authorised for
_ a two-hour flight in the training ar ea which
was over French Island.
The pilot and a passenger took-off at about
1445 hr. The tanks contained 100 litres of fuel.
The aircraft had flown about three hours
already that day and h ad about 36 hours to go
before the next 100 hourly.
The weather was warm and humid.
A number of manoeuvres were carried out in
the training area including power changes. Aircraft behaviour and engine r esponse appeared
normal.
After about an hour's ·flying, the pilot decided
to try a practice forced landing into a disused
dirt airstrip at the north-west corner of the island.
The aircraft was at a h eight of 1000 feet and
the pilot selected carby heat on before reducing
power. He performed t he norma l drills - glide
speed, field selection and trouble checks and
then set up a pattern for an approach into the
north.
He did not exercise the throttle during the glide.
Approaching a h eight of 200 feet on final, with
30 degrees of flap , he selected carby h eat to
cold and pushed the throttle forward.
The engine didn't r espond fully - only about
1300-1 500 rpm was obtained. He turned right
towar ds open country and opened and closed
the throttle twice without a satisfactory
response.
He reduced the flap setting to 20 degrees. Mixture was fully rich and the carby heat w as left
in the cold setting.
The stall warning was sounding and the airspeed was decayirig.
The pilot avoided sever al trees, ' ballooned' over
three or four fences and touched-down in an
open , level paddock. The aircraft ran through
the long grass and crossed a ditch - the pilot
tried to pull the aircraft over the ditch but it
hit the far s ide. This broke the nos ewheel and
the a ircraft came to rest on its nose.
No fault could be found with the aircraft that
would have led to the loss of p ower. The OAT
(plus 25-30°C) and t he dew point at the time
(plus 20°C) represented a predicted risk of
carby icing described as, 'serious icing descent power' .
I
THE student pilot was almost ready for his
licence test and had completed a solo and a
dual trip that day. The student and his
instructor refuelled the aircraft for another solo
flight.
Sixty litres were added and the pilot calculated
a total contents of 84 litres - which represented about four hours endurance w ithout
r eserves.
The tanks were drain-checked for water.
The pilot took off for a period of circuits and
completed about five touch-and-go's, the last of
which was a short field landing.
During the subsequent takeoff, at about
powerline height - t he engine failed. The pilot
pumped the throttle and the en gine picked up.
It failed again shortly afterwards and the pilot
was committed to a forced landing.
He turned right and headed for what he
assessed was the best paddock.
The pilot later recalled selecting carby heat on
base as soon as rpm was below 200() and he
could definitely remember de-selecting it on
final for the last landing. After touchdown he
had reduced the flap to 10 degrees and applied
full power. He was certain t hat th e throttle was
fully forward and t hat the engine was producing full power.
He also said that the fuel selector was not
touched during the flight - it was left on the
whole time. He noticed the oil pressure was in
the green after the failure.
The aircraft h ad suffered two previous engine
failures attributed to water in the fuel and it
had previously been usual to find some w ater
in the fuel samples during the drain check.
At the t ime of the accident the ambient temperature was plus l0°C and the dew point was
plus 5°C. D
Peeper
Keepers
As the basis for defining our requirements, let's
define the viewing distances as follows:
• NEAR - for reading charts and maps
• INTERMEDIATE - for r eading the main
instrument panel
• DISTANT - for looking outside t he aircraft.
What sort of bifocal?
The most common forms of bifocal are t he
round segment, the D segment and the executive or E-line.
D segment bifocal
This article follows one published in the winter 1987
edition - ASD 133, which outlined some of the visual
problems associated with advancing years, especially
presbyopia. Now it is hoped to give you some help to
obtain the best multiple-focus glasses to enable you to fly
more effectively and safely. This is in fact an abbreviated
version of a booklet produced by the Department for
optical p rescribers. The authors were B.L. Cole and A.J.
Vingrys of the Victorian College of Optometry, University
of Melbourne.
CQUIRING the best possible glasses
requires co-operat ion between y ou and your
_ lens prescriber. To do this y ou need to
know what types of glasses are available and
how to s pecify your cockpit environment and
optical r equirements.
A
Executive or E~li ne bifocal
Round segment bifocal
The straight-line transition of the D seg and
E-line is an advantage especially for pilots
who need to scan a w ide horizontal arr ay of
instruments and these two forms of bifocal
are t herefore recommended .
Some people prefer the wider segment of the
executive bifocals. The D seg bifocal is s uitable and wide segment forms, 28 and 35 mm
wide, are available. (The usual segment width
is 25 mm, which gives a 45 degree field-ofview.)
The D segment bifocal provides clear, distant
vision thr ough the outer parts of the lens to
the right and left of the near segment. This
may be an adv antage during t akeoff and landing when peripher al visual informat ion is
needed.
Glass or plastic?
There are two main materials, crown glass and
a plastic known as CR39. A ver y tough
polycarbonate lens material is also a vailable.
All three lens materials are acceptable . CR39
and polycarbonate h ave these advantages:
• highly impact resistant
• light weight
• low thermal condu ctivity and less liable t o
foggin g.
CR39 is more vulnerable to surface damage
than glass and CR39 lenses must be car efully
protected from scr atchin g, esp ecially during
cleaning. CR39 can be obtained with an
abrasion-resistant coating to r educe its susceptibility to surface d amage .
Height of the bifocal segment
The near segment of the bifocal h as to be set
at the height to best s uit the needs of the
wearer. This is a critical judgment to be made
by t he pr escr iber. The p ilot can h elp by giving
valid (preferably measured ) information about
the position of his eyes in relation to the layout of the flight deck of his aircr a ft. If the
segment is set too low, the head may have to
be tilted back uncomfortably - in order to
look through the near segment . If t he segment
is too high, it may interfere w ith distant
vision or may require t he head to be tilted
forward - to avoid interferen ce by t he n ear
segment.
�l
-Aviation Safety Digest
136
Aviation Safety Digest
136
I
Segment ->et low
Usu~l
height of 5egmen t
Segment high
When making these observations, remember to:
• have the seat adjusted to its usual position,
bearing in mind that pilots often adjust the
seat to different positions in the different
phases of flight
• adopt a normal body and head position - not
too erect, as we tend to relax our posture during a long flight
• ensure that the spectacle frame is seated
properly on your face.
If your presbyopia is at an early stage, you
and your ophthalmic adviser have an important choice to make about the height of the
near segment.
The height can be set so that you view the
instrument panel through the -near segment as well as using it for charts and manuals at
an ordinary reading distance.
Alternatively, the segment can be set low so
that it is used only for charts, manuals and
reading. When viewing the instrument panel
you will look over the top of the near segment
to use the distant part of the bifocal.
The choice will depend on:
• whether or not you are having any difficulty
reading instruments on the forward instrument panel, and
• your residual accommodation (you need at
least 2.75 to 3.5 Diopters of accommodation if
you are to see the instrument panel clearly
and comfortably through the distant part of
the bifocals).
You should also bear in mind that if the segment is set low, the bifocals will not be very
suitable for reading at home and you may need
a separate pair of reading glasses or bifocals
for everyday use.
Make sure the seat is adjusted to its usual position and that you take account of the fact t hat
you may use the seat in more than one position
depending on the phase of the flight.
,,
Usually the critical distances in order of
importance, are:
• flight instruments
• engine instruments
• check lists (including EFIS and flight management displays)
• approach charts
• radios and navaids
• general charts.
The problem of the overhead panel
The top of the segment should be aligned with
the glare shield (A) when it is planned that the
near segment is to be used for all near work
including the forward instrument panel. When
it is set so that the forward instrument panel is
to be viewed by looking through the distant
part of the lens, the segment height needs to be
set to allow a clear view of the instrument
panel (B).
How to nominate the segment height
Working distance
Optometrists and spectacle dispensers are
s killed at setting the segment height correctly,
but flying is a demanding occupation and it
may be worth spending a little more time than
usual in defining your requirements.
Before the lenses have been fitted to your
chosen spectacle frame, I suggest that you take
the frame away with you - to make some
trials on segment height in your ~ircraft. With
the spectacle frame correctly positioned on
your face, sit in your us ual seat and stretch
transparent, adhesive tape across the frame so
that the upper edge of the tape is at the height
desired for the segment.
If you wish to use the near segment for viewing
the instrument panel, the upper edge of the
tape should be aligned with the glare-shield,
between the instrument panel and the
windscreen.
If the near segment is to be set low, for reading
maps and charts but not the instrument panel,
the tape should be set so you have an
unimpeded view of the panel.
The next problem is to ensure that the glasses
prescribed are suited to the particular near
working distance imposed on you by the flight
deck of your aircraft. This may not be a critical
problem for your first pair of near glasses but
it becomes increasingly critical as presbyopia
progresses.
Near glasses have a limited range of clear
vision which depends on the power of the
lenses prescribed and y our residual
accommodation.
It is vitally important that the range of clear
vision encompasses all the near objects t hat
need to be seen clearly . Typically, this will
range from the reading of maps and operations
manuals at ordinary reading distances of
450 mm to the more distant parts of the instrument display which may be 750to1300 mm away.
Sit in the pilot's seat and have another person
measure the distances between your eye and
each near viewing distance. Make the measurements in millimetres and take them with you to
your optometrist or ophthalmologist.
The overhead panel can be a problem both
because it is overhead and because it can be
very close to the pilot's eye. Such a close distance means that the presbyopic pilots will
have difficulty seeing labels and numerals
clearly. Yet in order to view through the near
segment of bifocals or through look-overs, it is
necessary to t ilt the head bacl} awkwardly. This
can be a problem in some aircraft types. Don't
forget, too, that some aircraft have placards
and checklists attached to the back of the sun
visors .
What are the possible solutions if the overhead
panel proves to be a problem?
• the s implest solution is to lift up the bifocals
(or look-overs) so that the head does not have
to be tilted back so far
• flip-down spectacles can be provided with an
additional lens power to clearly focus the
overhead panel when viewing through the
upper, distant part of the bifocal lens. However, flip-downs are cumbersome and they
might be accidentally left in position, blurring
distant vision. There is also a risk that they
may flip down accidentally during some critical phase of flight
• there are vocational multifocals which have a
n ear segment in the upper part of the lens as
well as the u sual near part in the lower part
of t he lens However, the position between the
two segments is only 12 or 15 mm deep giving
a vertical field-of-view of only 26° or 31°
which pilots may find impedes their visual scan.
• a special multifocal can be constructed to provide a small near viewing segment in the
upper part of the lens. This can be achieved
by cementing an additional lens in the appropriate position or by special fabrication.
In general, the more complex solution should
only be pursued if there is a substantial and
persistent problem with the overhead panel.
The overhead panel usually does not demand
critical visu al acuity a nd may not be used in
critical phases of flight - so it may not present
a serious problem.
Viewing distances to the overhead panel can
vary from 380 to 700 mm depending on aircraft
type and the part of the panel viewed.
The need for trifocals
As presbyopia advances, the power of the near
spectacle correction must be increased to compensate for the further loss of accommodative
power. As a result , the range of clear v ision
decreases .
When this occurs, trifocals are usually necessary. Trifocals provide an intermediate s egment
which has half the power of the lower near segment. The diagram shows how trifocals solve
the problem.
D seg trifocal
E-line trifocal
0
0
E/ D trifocal
Vocational trifoca ls
(The power of the intermediate segment is
usually half that of the near segment and
focusses for intermediate distances.
The intermediate segment of trifocals is usually
7 mm deep (8 mm for the E/ D) . The E/ D is also
available with an intermediate segment 13 mm
deep, but in a limited range of near a dditions.
(Trifocals with non-standard intermediate segment depth can be specially fabricated.)
The figure shows the range of clear vision
through the intermediate segment of trifocals of
different power. It is evident from the figure
that the intermediate segment gives clear vision
over a w ide range for the longer distances, sufficient to en sure clear vision of the instrument
panel.
Trifocals are available in a D seg form, in an
execut ive or E-line form and in a combined E/ D
form. All th ree types ar e a cceptable. Of course,
the executive form prov ides a wider horizontal
field-of-view and might t h erefore r equir e less
frequent head movements.
�Aviation Safety Digest
If you are not eligible for a free issue, or if you would li ke additional copies of the Digest:-
136
The intermediate segment of the typical trifocal
is about 7 mm deep. Since spectacles are normally located about 25 mm from the centre of
rotation of the eye, the vertical field-of-v iew
through the typical intermediate segment, is
about 15 degr ees. At a distance of one metre
this means a vertical distance of about 280 mm
is seen clearly through the intermediate segment. This may be too limited for a complex
instrument panel extending some distance
below the windscreen - although head movements can compensate for this limited
field-of-view.
It can also be argued that during an approach
and landing, the pilot's visual tasks involve
alternating between scanning the instrument
panel and viewing outside the aircraft. Reading
maps and manuals at close distance, say
450 mm, occupies less time and is usually done
during less demanding phases of flight. If this
is the case, then for flying, the distant and
intermediate segments of trifocals may be more
important than the near segment.
So for pilots, it may well be an advantage to
increase the size of the intermediate segment at
the expense of the near segment.
The E/ D trifocal has a slight advantage in this
respect. Its intermediate segment is 8 mm deep
giving an 18° vertical field compared to 15° for
the standard trifocal. In addition, the intermediate segment surrounds the D shaped near
segment.
The E/ D occupational trifocal gives a deeper
intermediate segment (13 mm) but is only available in a limited range of near additions.
Trifocals with wider intermediate segments can
be specially fabricated but at additional cost.
If standard lenses are to be used, the E/ D may
be the optimum trifocal for pilots .
Prescription sunglasses
Glare is often a problem when flying above
cloud or when flying into the sun.
-~~--
Clip-on sunglasses can be obtained to clip over
bifocals or trifocal glasses and can be quickly
removed when there is a sudden transition from
glare conditions to relatively dark conditions as can occur during a descent. They have the
further advantage of being inexpensive.
Getting used to it all
The need for bifocals or trifocals is a reminder
that the years are passing. Comfort yourself
with the thought that you are not alone everyone eventually faces the same problem.
After a ll, life begins at 40 and you have the
benefit of maturity and experience. At least the
solutions to the visual problem, although not
good enough to restore youthful vitality to the
accommodative mechanism of your eye, are
simple and innocuous. You do get used to the
idea of wearing glasses, nuisance that it may be.
But then you get your first pair of bifocals. You
may find this a little disturbing at ~irst. Your
first reaction might be that you cannot tolerate
them. But persist. After a week or two, you will
no longer notice the reading segment and you
will switch from the distant part to the near
segment without noticing that you have done so.
Make sure your bifocals are kept in good
adjustment because if they are not, they will
not work as well nor be as comfortable as they
should be. Return them to your optometrist or
dispenser whenever you need to have them
readjusted. Never adjust your own spectacles.
Finally, look after your glasses. Keep them
clean and free from dirt and grease. Make sure
the lenses do not get scratched. Scratched and
dirty lenses can obscure your vision in bright or
glare conditions just as can a dirty windscreen .
To get the best glasses requires co-operation
between yourself and your prescriber. The
check list below is a starting point but seek the
advice of the lens prescriber.
Perhaps your flying life need no longer be
'Through a Glass Darkly'!! 0
Five is s ues $A 16 .00
or over thi rty years, the Aviation Safety
Digest has been an integral part of
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In July 1986, responsibility for the Digest was
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WORKING DISTANCE CHECKLIST*
Working distance (m)
Locationst
Nearest Distance
Farthest Distance
Flight instruments
Engine instruments
Checklists
EFIS flight management
display
Approach charts
Radio
General charts and
manuals
Other
tLocation may be forward instrument panel (FIP), central instrument panel (CIP), central console (CC), overhead panel (OP), glare shield (GS), control column (C) .
*It would be useful if pilots completed this table prior to their eye examination.
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relating to aviation safety. Input from student pilots and
flying instructors is partic ularly welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any
self-confessed infringem ents that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
P.O. Box 594
CANBERRA A.C.T . 2601
Australia
Aviation Safety Digest 136 / i
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li£]
Aircraft accident reports
AGPS
Third quarter 1987
Send to:
The following information has been extracted from accident data files maintained by the Bureau
of Air Safety Investigation. The intent of publishing these reports is to make available
information on Australian aircraft accidents from which the r eader can gain an awareness of the
circumstances and conditions which led to the occurrence.
Mail Order Sales
Australian Government Publishing Service
G. P.O. Box 84
CANBERRA A.C.T. 2601
At the time of publicat ion, many of the accidents are still under investigation and the
information contained in those reports must be considered as preliminary in nature and possibly
subject to amendment when the investigation is finalised.
I wish to subscribe to . . .. . .. copies of Aviation Safety Digest for five issues at $16.00
including surface postage in Australia and overseas.
'
Readers should note that the information is provided to promote aviation safety it intended to imply blame or liability .
Name ..
Preliminary reports
Add ress .............................................. .
The following accidents are still under
investigation
Postcode
Fixed Wing
Signature .... . .... . ..... ... ............................... Date ... ... ... .
18 Oct, CESSNA 182 A, VH·WCG, Sport parachuting,
ARATULAQLD
The pilot was conduct ing his first drop of parachutists and
also his first takeoff from this strip. The strip was rough
and the pilot, being concerned that unnecessary stress may
be placed on the nosewheel, r aised the nose early in the
takeoff run. The aircraft became airborne after a ground
roll of about 350 metres in a nose high attitude at an indicated airspeed of 50 knots. Almost immediately the left
wing dropped and t he aircraft turned to the left with the
rear fuse lage and mainwheels coming into contact with the
ground. The aircraft continued under full power beyond t he
end of the strip striking two logs and a sapling before
coming to rest embedded in a large felled tree.
I enc lose my cheque/money order for $ ........ .. ..... .. .... . .. . .. payable to AGPS
or charge my:
D AGPS account no.
D Bankcard
D Visa
D MasterCard
Card No . . .. .. . . . . ........ ... .. .... . Expiry Date . . . .
-~------------------------------------------
20 Oct, CESSNA A188B Al, VH-EUU, Aerial agriculture,
INNISFAIL QLD
The pilot was carryin g out aerial spraying on a banana
plantation in hilly country. As he was completing the clean
up run, a long one side of a section of the plantation, the
aircraft struck a set of powerlines which ran diagonally
across the flight path. It subsequently struck the ground in
a nose down attitude and apparently caught fire on impact .
Dear Sir,
29 Nov, CESSNA Rl72 K, VH-UDU, Non commercial pleasure, GATTON QLD
Having just completed a short flight with the President of
the local aero club onboard, the owner of the aircraft
offered to allow another pilot, who had also been on the
aircraft during the flight, the chance to carry out a circuit.
After changing control seats, the pilot completed a circuit
and witnesses reported that the subsequent landing was
very heavy. The aircraft bounced into t he air to about 20
feet, power was applied and it was observed to climb
slowly, in a high nose attitude, to about 80 feet above
ground level. It then entered a skidding turn to t he left
through 180 degrees to be heading in a downwind direction.
The witnesses stated t hat the flaps remained in t he fully
down position and aircraft appeared to be laterally unstable
until at an altitude of about 50 feet, the left wing and nose
dropped suddenly and the aircraft impacted the ground.
- . . . . . . . ... . . .... . .. .... ... . . . ... . ...
. . .... .. . ........... . . ... . . . . . . . ....
Yours sincerely, .. . .. . .... . . . .. . .. .. . .. ... ........ .. ... . . .... ... . .. . . .. . . . .
Name: . . . ....... . .. . . ..... ... . . . ... .... .. .... . ... ..... ... .. ..... .. . . .... .
Add ress : ... .... .. . . . . . .. . . .. . . . .. . . .. .. . .. . ....... .. . ... . . .. . ....... . ... .
Details to be published?
0
No name
ii/ Aviation Safety Digest 136
0
Initials okay
0
Full name okay
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:t
07 Dec, RUTAN VARI EZE, VH-EZH, Non commercial pleasure, GLADSTONE QLD
At the commencement of the final approach the aircraft
was positioned above t he normal approach profile wit h a
higher t han normal airspeed. The pilot reported that the
in no way is
correct airspeed and approach profile was regained but that
he was slow with the use of power to correct the rate of
descent. The aircraft subsequently landed heavily on the
mainwheels and w hen the nosewheel contacted the runway
the nosegear leg failed.
22 Dec, AYRES S2R-Rl820, VB-HGT, Aerial agriculture,
MUNGINDI QLD SN
The pilot reported that he had completed the spraying of
one a rea and while waiting for the markers to move to the
next area, he completed two short runs in the vicinity of
t wo sets of powerlines. When he commenced the next long
run the fin of the aircraft struck one of the powerlines. The
impact resulted in the pilot experiencing difficulties in
controlling the aircraft so he decided to land the aircraft in
the paddock, rather than return to the departure strip. During t he landing roll the aircraft ran through two fences
before coming to rest nose down in a gully.
26 Oct, BEECH 58, VH-EZG, Training, BANKSTOWN NSW
The flight was part of a t ype endorsement. After completing the upper air sequences five circuit and landings were
carried out without incident, although the fift h landing was
reported as being heavier than normal. On the downwind
leg of the next circuit, both pilots reported that the gear
was found to b e still extended when the pre-landing checks
were commenced. When the aircraft subsequently touched
down the left maingear began to collapse. The instructor
assumed control and attempted to keep the aircraft straight
along the runway. However, the aircraft veered to the left
and the nosegear collapsed prior to t he aircraft coming to
rest, ten metres off the side of t he runway.
31 Oct, PIPER 32-R301, VH-WIV, Non commercial pleasure, GRIFFITH NSW
The aircraft was observed to descend rapidly, in a high
nose attitude, during t he later part of the approach. It
struck the ground heavily and the right maingear collapsed.
09 Nov, BEECH 95 B55, VH-EHN, Charter - cargo operations, BREWARRINA NSW
The pilot reported that as fu ll power was applied on the
takeoff run he heard a loud bang, and the aircraft yawed to
the right. He shut down the right engine and brought the
aircraft to a stop.
An inspection of the aircraft revealed that the right propeller assembly had failed at the hub. One blade had separated
from the hub and struck the nose section of the aircraft.
The blade becoming dislodged resulted in an out of balance
situation which caused the crankshaft to shear behind the
attachment flange.
10 Nov, DE HAV C2, VH-IMJ, Activities Associated with
Aerial Agriculture, GLEN INNES NSW
The aircraft was being operated from a strip with an excessive longit udinal gradient, and takeoffs were being conducted with a two to three knot tailwind. It was reported that
Aviation Safety Digest 136 / iii
�on the sixth takeoff of the day that a strong wind gust substantially increased the tailwind. The a ircraft did not
become airborne as expected and the pilot is reported to
have pulled t he hopper handle in an attempt to reduce the
weight of t he aircraft, and clear the boundary fence. The
load failed to d ump normally. T he pilot applied more flap
and the a ircraft lif ted off in a tail-low a t titude. The
mainw heels cleared the fence but the t ailwheel struck a
fence post . The aircraft rema ined airborne and the pilot
subseq uently landed it without further incident at Glen
Innes aerodrome, a distance of about fo ur kilomet res from
t he point of takeoff.
I9 Nov, BEECH V35, VH-CFH, Non commercial pleasure, CASSILIS NSW I N
The aircraft was cruising at 10,000 feet a msl on a Night
IFR fli ght w hen the passenge r , who is a pa rt owner of t he
aircraft , noticed t he ma nifold pressure d rop t wo inches. The
engine rpm a lso dropped and t he pilot changed fuel tanks,
switched on the fuel boost pumps and moved the throttle
a nd pitch controls to t he fully forward position. At a bout
the s ame time the manifold pressure and engine rpm readings reportedly dropped to zero. The a ircraft was set up in
a glide and despite several attempts eng ine power could not
be restored. The pilot tracked the a ircr a ft towards Cassilis
and descended over the town before taking up a westerly
heading in prepa ration for landing. At about 20 feet a bove
t he ground t he aircraft s truck a t ree and then landed
heavily on a steep bank.
An inspection of the engine found t hat t he crankshaft had
fa iled.
05 Dec, FAIREY AS-6, VH-HMW, Test, CAMDEN NSW IN
The a ircraft had been out of service for severa l mont hs,
undergoing engine maintenance. This was t he first flight
following the completion of that ma intena nce. After takeoff
t he aircraft was observed to climb t o about 15 00 feet,
trailing black smoke. It t hen t urned t owa rds the a ir field
and began to lose height rapidly unt il descend ing out of
view behind t rees. The a ircraft t ouched down heavily, tail
first , in a paddock, bounced and fo llowing t he second touch
down slewed sideways through a fence and down an
embankment .
An inspection of the engine revealed that both the right and
left camshaft inclined d rive upper bevel shaft gears had
been overheated as a result of a lack of lubrication. The distortion of t he left d rive was sufficient to d isconnect it from
its camshaft drive bevel gear result ing in t he s ubsequent
loss of power.
The engine was fitted wit h an external oil priming system
to lubrica te the camshaft d rives during and immediately
after sta rting. This system was con nected on each side into
the appropriate valve tra in oil supply by 'T' fittings and
flexible hose assemblies. During reassembly, associated wit h
the latest engine ma intenance, the 'T' fittings were omitted
and t he fittings in t he front case drillways were blanked
wit h plugs, effectively cutting off t he engine oil supply to
the camshaft drives.
22 Dec, SMITH 600, VH-IGV, Charter - cargo operations, CASSILIS NSW llE
The aircraf t had been chart ered to carry freight to Coolah.
The pilot was accompanied by a friend who was also a pilot
but not endorsed on this aircraft type. The flight apparently proceeded normally and about 18 minutes before the
estimated arrival t ime at Coolah the pilot reported t hat a
descent from cruising level had been commenced. Witnesses,
located some 55 kilometres from the destina t ion , observed
t he a ircraft flying at a bout 1000 feet a bove the terrain and
performing a series of t urns until it entered a spiral
descent , t hen a steep dive, before impacting t he ground.
I3 Oct, PIPER PA25-235, VH-HMC, Aerial agriculture,
DONALD VIC lOE
During the pull up at t he end of a clean u p run, a small
note pad fell to the floor of t he cockpit. The pilot leant forward to retrieve it but almost immediately the aircraft
struck t he ground.
iv/ Aviation Safety Digest 136
18 Oct, AIRBUS A300, VH-TAC, AIRLINE TRANSPORT,
MELBOURNE VIC
During the landing roll on Runway 27, the Aerodrome Controller noticed smoke issuing from the left maingear
assembly. He advised the pilot of this as the a ircraft
entered the taxiways, and the pilot confir med that he had a
hot wheel ind ication in the cockpit. The fire services were
summoned a nd followed t he aircraft on its taxi path. Just
after the a ircraft crossed Runway 34, the Surface Movements Cont roller advised t he pilot t hat fi re had broken out
in the left maingear. The aircraft was brought to a halt and
the fire was extinguished using the rapid intervention
vehicles. The pilot ordered an evacuation of the aircraft
and the injuries were sustained dur ing the evacuation.
Investigation to date has revealed t hat the overheat ing
which led to t he fire was d ue to continuous application of
the brake on No.2 wheel. This condition resulted from a
short circuit in an electrical solenoid of t he anti-skid unit
t hat controls t he brake for that wheel.
This occurrence was upgraded from incident to an accident
on receipt of ad vice t hat some of the injuries sustained
were serious.
02 Nov, PITTS SlE, VH-XIl, Non commercial - practice,
WHITSTOCK FIELD
After making two touch and go's, the pilot decided to make
the t hird landing a full stop. At the end of the landing roll
the aircraft commenced a ground loop to the ·left. Despite
the application of f ull power, directional control could not
be regained and the a ircraft entered an a rea of small saplings to the left of the s trip, and overturned. The landing
d irection was to the northeast and the prevailing wind was
a northerly, which resulted in a crosswind component of
approximately 10 knots.
03 Nov, CESSNA I 75, VH-WAR, Non commercial pleasure, LEONGATHA VIC 13SSW
The pilot was departing to t he southwest from his proper ty
strip in conditions of strong a nd gusty northwesterly winds .
At about 200 feet agl, the aircraft experienced difficulty
maintaining positive climb. Strong downdrafts generated by
t he high terrain ahead resulted in the aircraft descending to
100 feet agl whilst in the climb attitude with full power
applied to t he engine. The pilot realised he could not
out climb t he terr ain a nd picked an open area just to the
right of his tr ack in which to land. The land ing gears were
dislodged when the a ircraft contacted the soft sur face of
that landing area.
08 Nov, PIPER 32 300, VH-WGO, Non commercial pleasure, WOODEND VIC 5ENE
As the nose was raised at the end of the take-off run on the
650 metre long property strip , t he pilot reported t hat t he
engine miss fired and lost power. Although t he engine
recovered, t he pilot was not cer tain that it was producing
full power a nd so elected to abandon the take-off attempt.
In an effort to clear the fence at the end of the strip the
pilot applied back pressure on the control column but the
noseleg failed to clear the top railing. The noseleg collapsed
during the s ubsequent ground roll.
11 Nov, CESSNA A188 Al, VH-KQB, Aeria l agricul ture,
ELMORE VIC
The take-off attempt was made in cond itions of lef t
crosswind. When the t a ilwheel left t he ground at about 25
knots, the aircraft swung left but the application of right
brake and full right rudder failed to correct t he t urn. The
pilot closed the t h rottle and t he aircraft completed the
ground loop which resulted in t he collapse of t he right gear
leg.
I6 Nov, PIPER 25 235, VH-AMZ, Aerial agricult11re,
ECHUCA VIC 8SSE
The pilot was spraying a tomato crop and had been briefed
by the farmer as to the location of powerlines near the area
to be treated. Towards the end of the j ob t he pilot positioned to once again fly under a powerline, but struck
another powerline 80 metres from the one he was intending
t o fly beneath. He was unaware of t he presence of t hat line.
The aircraft impacted the ground and was consumed by t he
resulting fire.
The pilot had not treated t hat paddock previously and had
not performed a pre-treatment ground inspection of the job.
20 Nov, CESSNA A185 F, VH-TLO, Non commercial pleasure, SILVAN RES VIC
Af ter take-off from a property strip near the Silvan Reservoir, t he aircraft was flown at a low height above the calm,
s mooth surface of the water. A left turn was completed at
low level, but shortly thereafter the aircraft struck the surface near t he middle of the dam. On initial contact, water
entered the front of the cabin and the engine ceased running. The aircraft t hen bounced back into the air and the
pilot attempted, unsuccessfully to re-start the engine. The
aircraft lost height and skidded along the surface to a halt
before the nose began to sink. The three occupants evacuated the a ircraft but only one passenger succeeded in
reaching the shoreline.
Unt il t he aircraft struck the surface of the reservoir, there
was no indication of engine or control problems.
24 Nov, PEREIRA OSPREY 2, VH-LII, Test, CAPE
LIPTRAP 5ENE
At a height of a bout 50 feet on initial climb, the aircraft
suffered a birdstrike which resulted in the canopy being
broken. Although t he pilot's vision was inhibited by the
effects of windblast, he was able to return for a landing.
After t he engine was shut down the pilot heard a noise,
determined that the aircraft was on fire and vacated just
before it was totally consumed. It is likely that as a result
of the birdstrike, a fuel line was damaged which allowed
fuel to spray onto the hot engine/ exhaust area.
04 Dec, TRANSAV PL12-T300, VH-AUL, Aerial
agriculture, DEVONPORT TAS 5E
During the clean up run, after spraying a crop of potatoes,
the engine s uddenly lost power. The pilot selected the right
tank and t urned the fuel boost pump ON , however the
engine failed to respond. The aircraft struck the ground,
collapsing the r ight main gear.
T he pilot stated that prior to take-off he checked the quantity of the inboard fuel tanks. He took-off with the left tank
selected, which contained 23 lit res of fuel, intending to
change to t he full r ight tank prior to starting the spraying.
He omitted to change tanks as planned and the engine failed
due to fuel exh aus tion even though the right tank was full.
Investigation is continuing into the failure of the engine to
re-start after t he full tank and boost pump were selected.
11 Dec, CESSNA 172-P, VH-RWV, Instructional - solo
(supervised ), CAMBRIDGE TAS
The pilot was carrying out a period of solo circuits as part
of a check on t he aircraft type. Following the third circuit,
the aircraft was observed to approach and land normally
into the 10 to 15 knot headwind. During the subsequent
land ing roll, while still travelling at about 30 knots, the aircraft veered suddenly to the left. The pilot applied full
right brake and rud der and then both brakes in an attempt
to stop the aircraft. However, before the aircraft stopped it
struck one of t he boundary fence posts.
An inspection of the aircraft did not reveal any mechanical
defects that could have contributed to the occurrence, and
the pilot was unable to explain the reason for the loss of
d irectiona l control.
24 Dec, CESSNA 180, VH-MPW, Non commercial pleasure, MOORABBIN VIC
The pilot reported that after touchdown the aircraft
encountered a strong gust of wind from the right. The aircraft swung s uddenly to the right and the pilot was unable
to maintain con trol. The left maingear leg bent and the
airframe distorted, allowing the left door to become dislodged. The aircraft finally came to rest off the side of the
runway, having groundlooped through 130 degrees.
11 Oct, PIPER 23-250, VH-ESA, Non commercial pleasure, OODNADATTA SA
After refuelling, the pilot started the left engine normally
but was unable to start the right engine. The starter was
engaged a number of times but t he engine would not maintain idle RPM. The pilot's son approached the aircraft and
advised that a fire had broken out in t he right engine ba y.
The engines were shut down immediately but not before the
fire had caused substantial damage to that bay .
09 Nov, CESSNA 404, VH-ANM, Charter - passenger
operations, PEPPERMINARTI NT
After landing, the aircraft was backtracked on' the runway
to enter the apron area when the nosegear collapsed. The
pilot reported that at the time of the collapse the aircraft
was moving at about 4 knots because he had slowed t o take
the turn into the apron. He said that there was no unsafe
indication and that he had not inadvertently raised the gear
when he retracted flap.
23 Nov, CESSNA 172-P, VH-FCQ, Training,
DELISSAVILLE NT
The student was carrying out a practice forced landing on
Delissaville strip as part of a pre-licence test. After t he
student had initiated the flare for landing, the instructor
became aware of a high descent rate but too late to prevent
a hard landing. The instructor took over control, carried out
a touch and go, then advised the student to return t o Da rwin. Inspection there revealed that the aircraft had suffered substantial damage as a result of the hard landing.
12 Dec, AMER AIR 5, VH-ETT, Non commercial pleasure, PORT LINCOLN l4NW
The aircraft touched down 385 metres into the 675 metre
long paddock. The pilot applied the brakes but reported
that they did not slow the aircraft. He decided that insufficient area remained for a successful go-around to be carried out and attempted to steer the aircraft through a gate.
The right wing struck the gate and the aircraft turned
through 190 degrees before coming to rest.
22 Dec, CESSNA 402-C, VH-TFD, Scheduled passenger
service, NGUKURR NT
After a reported normal touchdown, the aircraft was
allowed to roll through to the end of the runway before
commencing a left turn to backtrack the runway . During the
turn the right maingear collapsed.
An inspection of the aircraft revealed that the right
maingear leg actuator had failed.
01 Nov, BEECH A36, VH-RCS, Non commercial - business, KARAWARA WA
As the aircraft approached Jandakot the pilot noticed that
the engine RPM was increasing, and he was unable to control it with the propeller control lever. He partially closed
the throttle which enabled him to regain control over the
engine. A straight in approach to Jandakot was planned,
but just after the power reduction, the engine began t o
make unusual noises and the cockpit filled with smoke. The
pilot decided to make a forced landing on some playing
fields he had just overflown, but on approach he observed
that they were in use. He modified his approach to land on
a nearby , vacant rubbish tip and after touchdown the aircraft collided with a mound of earth and overturned.
Investigation revealed that there was no oil in the engine as
it had leaked overboard during the flight. This lack of
engine oil caused the propeller overspeed and internal fail ure of the engine.
09 Nov, CESSNA 2IO N, VH-CWN, Non commercial pleasure, ERONG SPRINGS WA
The aircraft was hired at Parafield for a holiday through
the north west of Australia. The pilot noticed that during
the roll out after landing, the aircraft tended to drift to t he
left . He modified his approach technique, by using different
speeds and flap settings, because he thought the veering
was pilot induced. During the landing at Erong Springs, the
pilot allowed the aircraft to roll for a short d istance
unimpeded by brakes, and t h en retracted the flaps. Almost
immediately, the aircraft veered sharply to the left off the
flight strip and collided with a large mulga tree before control could be regained.
Advice has been received that the aircraft may have been
involved in an unreported heavy landing just prior to it
leaving Parafield.
Aviation Safety Digest 136 / v
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Rotary Wing
02 Oct, HILLER UH12-E, VH-FFT, Commercial,
GEORGETOWN Q 80NE
The aircraft was cruising at an altitude of about 300 feet
above ground level when the pilot heard a loud bang followed by a vibration. The engine continued to operate for
about two to three seconds, before stopping. Because of the
unsuitable terrain, over which the aircraft was flying, the
pilot was forced to attempt a landing into trees and the aircraft rolled on its side.
An inspection of the engine found that the number 3 connecting rod had failed.
21 Nov, ROBINSON R22, VH-HBG, Non commercial pleasure, DALBY QLD 48W
After taking delivery of his new helicopter the pilot carried
out an acceptance flight and reported to maintenance personnel that the collective control felt stiff. He was assured
that this was normal for an aircraft that was new. The following morning the pilot decided to take two of his relatives for a short flight around their property. Near the
completion of the second of these flights, as the aircraft
was descending through 200 feet for landing, the rotor rpm
warning horn sounded. The pilot stated that he chose an
area on which to land, increased the throttle setting and
slightly lowered the collective. The aircraft struck the
ground at a forward speed of about 40 knots on the heel of
the both skids and the tail rotor. It then skidded, rocked
forward and the main rotor severed the tailboom before the
helicopter turned through 180 degrees and came to rest on
its right side. Both occupants evacuated the wreckage, the
passenger suffering bruising as the result of contact with
emergency locator beacon that was mounted between the
two seat backrests.
24 Nov, BELL 206 B, VH-FJB, Charter - passenger operations, CAIRNS QLD 95SW
The helicopter was engaged in the transport of personnel
for stream sampling operations. The pilot was to pick up
one of the samplers from an area that was sloping. To
achieve t he pick up he manoeuvred the helicopter so that
the left skid was resting on a slab of rock and the right skid
was still in the air. Prior to the passenger boarding the aircraft, the pilot a~usted the position of the skid on the rock
and the right skid contacted a tree stump. The helicopter
subsequently rolled onto its side but both occupants
escaped without injury.
29 Oct, ROBINSON R22, VH.JVC, Instructional - solo
(supervised), JANDAKOT WA
After take-off, the pilot noticed a vibration in the a irframe
and immediately returned to land. Once on the ground he
decided that the vibration was too bad to continue so he
shut down t he engine. When he pulled the mixture control
to the idle/cut-off position, he felt the main rotor impact
the tail boom. Inspection showed that one main rotor blade
had slashed the tail boom. Strong, gusty wind conditions
were prevalent at the time of the occurrence.
10 Nov, BELL 206-B, VH-AZH, Non commercial - aerial
application, MT MAGNET WA 78S
Due to a loose seat belt banging against the fuselage of the
helicopte r , the pilot slowed the aircraft and commenced an
approach to land as soon as possible. Shortly after commencing the ap!]roach, the rate of descent increased rapidly
and the pilot's application of collective pitch to correct the
situation further increased the descent rate. During the
approach, both the audio and visual annunciators indicated
that the engine had failed. The pilot lowered collective but
then had to flare as t he aircraft was about to impact a
small mulga tree. The aircraft cleared that tree but was
damaged as a result of a collision with a nearby tree.
Gliders
31 Oct, SCHLEICHER K7, VH-UKY, Non commercial pleasure, GULGONG NSW
The pilot was attempting to complete a solo flight of at
least one hour duration as part of the qualification for the
issue of a C Gliding Certificate. Witnesses reported that
vi /Aviation Safety Digest 136
during the winch launch, the glider lifted off too early and
at too low an airspeed and then assumed a climb attitude.
The pilot stated that she released from the launch when she
became aware that the airspeed was too low. At about the
same time the right wing dropped and the aircraft turned
through 540 degrees before impacting t he ground with the
right wingtip.
02 Nov, GLASFLUGEL MOSQUITO, VH-GML, Non commercial - practice, CORRYONG NSW 47E
After about four hours flying, the pilot decided to return to
Corryong to land. Because the aircraft was too low he
tracked towards a valley in an attempt to find lift. The
attempt was unsuccessful and the pilot selected a sloping
area on which to carry out an outlanding. Shortly after
touchdown one wing struck a small bush and the aircraft
groundlooped.
20 Dec, ICA IS28 B2, VH-Gll, Instructional - dual,
BENALLA VIC
After completing some upper-air work, the circuit was
entered with t he student pilot at the controls. During the
final approach full airbrake was selected and a flare for
landing commenced. The flare was high and the instructor
took control of the aircraft. However, the aircraft contacted
the ground heavily before any remedial action could be
taken.
Ultralights
21 Nov, ULTRLIGHT, NOT REG, Non commercial pleasure, BULGA NSW
The owner pilot had recently recovered his a ircraft w ith
new fabric, and is reported to have taxied it up and down
the strip for a couple of hours before taking off. About 15
minutes after the aircraft became a irborne, a witness
reported that he heard a loud bang, followed by the engine
noise stopping, and then observed the aircraft spirally
toward the ground. The a ircraft impacted in an inverted
attitude in a creek.
05 Dec, SAPPHIRE ULTRALIGHT, NOT REG, Non commercial - pleasure, BANGHOLME VIC
The pilot was reported to be manoeuvring the a ircraft for
landing when he encountered a wind gust. This resulted in
the aircraft striking a tree, after which it crashed to the
ground.
Final reports
The investigation of the following
accidents has been completed
Fixed Wing
07 Oct, BELLANCA 8 KCAB, VH-CCC, Instructional dual, ARCHERFIELD 30S, Senior commercial, 13000 hrs
During a period of dual training, the instructor noticed that
the oil temperature was rising to an undesirable level and
that the oil pressure was falling. He elected to carry out a
precautionary landing on a short, disused agricultural strip,
rather than flying 20 minutes back to the aerodrome. The
student was to carry out a short field landing under the
supervision of the instructor, who was to talk her through
the exercise. At about the point of touchdown, the press-totalk switch in the rear pilot compartment failed and the
student was unable to hear any furthe r instructions. She
became apprehensive about the length of strip remaining
a nd applied heavy braking, which the instructor was unable
to overcome, and the aircraft nosed over.
An inspection of the aircraft revealed that a cleaning rag,
which had been missed during the daily inspection, had partially covered the oil cooler, rendering it less effective.
09 Oct, CESSNA 172 N, VH-MSJ, Non commercial pleasure, MAROOCHYDORE QLD 28WSW, Private, 00155
hrs
The pilot stated that during the flight the cloud base gradually lowered until he found himself in a valley with the
cloud on the hilltops. The cloud also closed in behind the
aircraft and t he pilot decided to find a suitable area and
land. He selected an area with some fences running through
it and landed the aircraft. During the landing roll the tail
section of the aircraft struck a fence post.
12 Oct, CESSNA U206 F, VH-SKZ, Non commercial pleasure, ESCOTT ST QLD, Private, 00080 hrs
The pilot reported t hat while taxiing after landing the
engine began to run roughly and stopped. He started the
engine again and continued taxiing to the fuelling depot.
After refuelling, the pilot carried out a fuel drain, removed
and replaced the spark plugs, which were found to be clean,
and started the engine . He completed an engine check and
found that the engine ran roughly at idle but ran smoothly
when operated at higher RPM. Shortly after takeoff, as the
pilot was setting climb power, the engine failed. He was
forced to carry out a landing on unsuitable terrain, and during the landing roll the nosegear broke off.
An inspection of the engine found that the throttle to fuel
control unit link rod assembly had become disconnected at
the fuel control unit end following the loss of a split pin.
This resulted in a mismatch between the internal position of
the fuel control unit and the position of the throttle butterfly which was set by the pilot when he moved the throttle
lever. The fuel control lever had apparently vibrated to a
position where insufficient fuel was available to the engine
to sustain engine power.
24 Oct, CESSNA 177, VH-DZI, Non commercial pleasure, BUNDABERG QLD 55W, Private, 00414 hrs
The pilot reported that the windsock at the strip indicated
a gusty 30 knot headwind and that he conducted t he
approach with full flap down and considerable power
applied. As he closed the throttle and flared, the aircraft
suddenly rolled to the right and dropped to the ground
impacting nose wheel first. Later inspection revealed that
the nose wheel leg mount had been broken and that the
lower firewall and cabin floor had been damaged.
Air mass thunderstorms were present in the area at the
time of t he accident and witnesses at the strip reported a
particularly s trong gust of wind exceeding 40 knots at the
time of t he accident. The wind direction was reported to
have changed t hrough 90 degrees shortly after the accident.
This accident was not subject to an on-site investigation.
scenic flights over the local area. On final approach, on the
second of t hese flights, the aircraft struck powerlines which
were strung across the eastern end of the str ip, about 85
metres prior to the threshold. The aircraft struck the
ground in a nose down attitude 25 metres beyond the
powerlines and came to rest inverted.
The pilot was unaware of the existence of t he powerlines
and had not sought the owner's approval or ascertained the
strip condition and dimensions before commencing t he operation. The poles supporting the powerlines were adjacent to
tall trees which resulted in them being difficult to see. Also,
it was late afternoon and the approach was being conducted
into t he west.
24 Nov, VICTA 100, VH-MUQ, Non commercial pleasure, SYDNEY NSW 8N, Private, 03500 hrs
The pilot had flown the aircraft from Archerfield to Sydney
earlier in the morning. It was his first long flight in the aircraft since purchasing it four months previously. He
reported that the fuel tank had been filled to capacity on
the day prior to departure from Archerfield , and during the
flight he had used the correct mixture leaning technique.
On arrival at Sydney the pilot calculated there was
adequate fuel for the flight to Camden and noted that the
fuel gauge indicated "10 gallons". Twelve minutes after
takeoff the engine lost all power. The pilot was then forced
to attempt a landing on a sports oval. The aircraft touched
down in the cent re of the oval and ran t hrough the boundary fence and over an embankment before coming to rest.
An inspection of the wreckage revealed that the engine had
failed after all t he usable fuel had been exhausted. The fuel
tank was subsequently filled to capacity and it was found
to hold only 119 litres, instead of the 132 litres specified in
the Aircraft Flight Manual, although the pilot believed the
tank capacity to be 159 litres. This reduction in tank
capacity had been caused by creases in the bladder fuel
tank, and it is also likely that the fuel gauge overread as a
result of the creased bladder.
07 Oct, PIPER 23 250, VH-WGN, Charter - passenger
operations, KIMBA SA, Commercial
After landing, as the aircraft turned left into the taxiway,
the left maingear collapsed. Inspection revealed that the
drag link centrebolt had failed.
Examination of the bolt revealed that it had failed due to
fatigue, which had initiated from pit corrosion along t he
shank of the bolt. It also displayed signs of in-service wear
which possibly contributed to the failure. This aircraft
reportedly operated from rough, uneven dirt strips on a regular basis.
26 Nov, MAULE M5 235C, VH-MEO, Non commercial aerial ambulance, SPRINGFIELD ST, Private, 00150 hrs
The pilot received a request at 5am from a neighbouring
property to fly a seriously ill person to a hospital some 150
kilometres away. During the approach to the property strip
the pilot realised t hat the aircraft was too high and too fast
so he attempted a sideslip to lose a ltitude. The aircraft
floated the full length of the strip before the pilot decided
to go around. During the go-around the aircraft stalled at
about 50 feet above the ground after the pilot had commenced a steeply banked climbing turn to avoid trees.
12 Nov, CESSNA 150 B, VH-RWM, Non commercial pleasure, KOOKYNIE WA, Private, 02400 hrs
As the aircraft was being flared for the landing, a mob of
sheep ran onto the strip. Two sheep were hit by the aircraft, one being thrown up against the left flap and the
other struck the right tailplane. The landing was completed
without further incident .
The strip was not fenced off from the rest of the paddock
and the pilot did not see the mob as he approached to land.
09 Oct, PIPER 28 140, VH-CNL, Instructional - solo
(supervised), CESSNOCK NSW, Student, 00036 hrs
Following a normal approach for landing during a period of
solo circuits, the aircraft touched down heavily and
bounced. Attempts by the pilot to recover from the bounced
landing resulted in a second more accentuated bounce.
Recovery from the second bounce was not effected and the
aircraft impacted the runway in a nose low attitude.
No pre-existing defects were found which could have contributed to this occurrence.
Rotary Wing
15 Nov, PIPER 22 150, VH-AUX, Non commercial pleasure, BAROOGA NSW, Private
The pilot had arranged to meet his son at the Barooga airstr ip. Although he had overflown the strip on several
occasions he had never previously operated into the strip.
After arrival, he was requested to take some friends for
17 Dec, HILLER UH12-E, VH-FXX, Aerial agriculture,
A YR QLD 6NE, Commercial 06450 hrs ,
Prior to commencing operations in the area the pilot carried
out an aerial reconnaissance to check t he location of
powerlines. He stated that he had almost completed the second load when he had the feeling that he was running out
of chemical. He believes that he momentarily looked at his
instruments to check for pressure and load remaining and
temporily forgot about the presence of the powerlines. He
subsequently saw the powerlines as the aircraft was
approaching t he end of the run, just before they were
struck by the canopy of the helicopter. Control was maintained with diffic ulty, and when the pilot noticed t hat the
aircraft was trailing wires he decided to land. The landing
in a cleared paddock was heavy, causing the skids to col-
A viation Safety Digest 136 / vii
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lapse, and the main rotor to flex downwards, striking the
t ailboom and severing the tail rotor.
The pilot stated that the powerlines were difficult to see
because of wire sag and the backdrop of trees and buildings.
This accident was not the subject of an on-site investigation.
Gliders
30 Oct, SZD 32A FOKA 5, VH-GEF, Non commercial pleasure, OAKEY QLD 6W, Glider, 00087 hrs
The aircraft was on the last leg of a cross country flight
when an area of sink was encountered. The pilot was forced
to make a landing in a paddock. During the subsequent landing roll the aircraft struck a concealed rock which resulted
in the fuselage breaking just forward of the tailplane.
Final updates
The investigation of the following
accidents has been completed. The
information is additional to or replaces that
previously printed in the preliminary report
Fixed Wing
04 Jui 86, CESSNA 172 F, VH-DNU, Senior comme rcial,
YARALLA STN QLD, 12700 hrs
The pilot in command was continuing a mustering endorsement which had been commenced the previous day. After
flying for about 85 minutes the pilots stopped for a break
of some 30 minutes. About 75 minutes after flying had
recommenced a person on the ground he ard a thump, and
the wreckage of the aircraft was discovered shortly afterwards. It had struck the ground in a steep nose down attitude while spinning or turning to the le ft , about 270 metres
to the south of the 30 strip.
Investigation revealed that, at some stage prior to the final
impact with the ground, the unde rsurface of the le ft wing
had contacted the ground, causing left aileron failure fol lowed by a loss of controllability. Medical evidence indicated that the pilot may have suffered a partial or complete
loss of consciousness due to a pre-existing heart condition.
However, it could not be determined whether this was a factor in the accident.
06 Jui 86, AMER AIR 5 A, VH-SYX, Private,
TANGALOOMA QLD, 00183 hrs
The first takeoff attempt towards the South was abandoned
because the pilot was uncertain whether the aircraft would
become airborne in the distance available . He noted that the
windsock indicated calm conditions, and a fter complet ing
another engine run, elected to take-off towards the North.
However, the windsock was sheltered from the prevailing
wind and did not indicate the five to seven knot t ailwind
existing for the initial part of the takeoff. Full power was
applied before the brakes were released, however acceleration appeared to be uneven, reducing as the wheels passed
through soft areas on the strip. The aircraft struck a fence
s hortly after lift-off, and touched down in a nose-high attitude. It then bounced several times, struck a mound of s and
and debris, and overturned.
The investigation established that with the tailwind and
soft wet surface conditions existing at the time there was
insufficient runway length available. The pilot recognised
the slow acceleration of the aircraf t, but delayed his
decision to abort the t akeoff attempt.
07 Dec 86, CESSNA 172 N, VH-MJJ, Priva te, TOOWOOMBA QLD, 00351 hrs
The pilot had t aken part in a flour bombing a nd balloon
burs ting competition and was returning to land. The front
viii / Aviation Safety Digest 136
seat passenger was a flying instructor and was acting as a
safety pilot and judge for the competit ion. The approach t o
land was high and the pilot decided t o go around, howeve r ,
the safety pilot suggested that sufficient strip remained for
completion of the landing.
The aircraft touched down about 600 metres beyond the
runway threshold and bounced. The pilot applied some
power and continued with the landing attempt, but the stall
warning sounded and the airspeed was noted to be below 40
knots. The front seat passenger ret racted flap to the takeoff setting and instructed t he pilot to apply full power and
to lower the nose of the aircraft. He then placed his hands
on the controls to monitor the pilot's control inputs. The
aircraft failed to accelerate as it flew along the strip about
a metre above the ground. It subsequently struck the a irfield boundary fence before coming to rest 160 metres
beyond.
14 Dec 86, CESSNA 182 F, VH-DIJ, Private, CHARTERS
TOWER 9N, 02300 hrs
The pilot reported that while he was conducting a landing
at his property strip, a calf and cow ran ont o and along the
strip. To avoid the animals he decided to delay any further
descent until the aircraft had passed the animals. However,
when the aircraft was about 15 feet above the strip, the
nose dropped and the nosewheel struck the ground resulting
in damage to the firewall, engine mounts and t he cabin
floor.
The pilot did not adequately monitor the airspeed during
the the extended hold off period and the aircra ft stalled
onto the strip.
This accident was not t he s ubject of an on-site investigation.
22 Dec 86, PIPER 18-125/ Al, VH-HCM, Commercial,
REDCLIFFE QLD, 07000 hrs
The student had completed about seven hours t raining and
was undergoing her second session of circuit training. The
instructor stated that the student had previously had difficulty with the directional control of the aircraft. On this
takeoff he a llowed the student t o manipulate only the rudder, so that she could concentrate on the d irectional control
aspect, while he manipulated all t he ot her controls. As t he
power was increased the a ircraft gradually swung to the
le ft. Approaching the left side of t he st rip the swing
increased and the instructor ap plied right rudder a t the
same time as the student . The aircraft swung to the right
and as it crossed the right s ide of t he strip the le ft wheel
dug into the ground and the a ircraft tipped onto the left
wing.
10 Dec 86, CESSNA 210 M, VH-MOB, Commercial,
NEWMAN WA 21NW, 00440 hrs
The pilot was ferrying t he aircraft to a nea rby strip
because of planned runway works at Newma n. After holding overhead the strip, while two other company aircraft
landed, the pilot descended the a ircraft into t he circuit and
completed the prelanding checks. He elected not to lower
the gear at that time because he considered the airspeed
was to high. The aircraft was subsequently landed w ith t he
gear retracted.
The pilot stated that he was concent rating on to carry out a
good landing. Althoug h he recalls touching the landing gear
selector on final, he does not recall checking t he gear position indicators.
This accident was not t he subject of an on-site investigat ion.
06 Jan 87, PIPER 28 161, VH-BSY, Senior comme rcial,
MCKINLAY 90SW, 04300 hrs
Shortly after the student had made a normal touchdown, a
sheep ran across t he strip in front of the aircraft. The
instructor had not been looking forwa rd, and he w as t a ken
by surprise when the student applied a considerable amount
of nosewheel defle ction in an effort to avoid the animal.
The aircra ft ran off t he side of the st rip and struck an
earth run-off water vane.
It was reported that the strip was 37 metres w ide and this
width is less tha n tha t required for a tra ining authorised
landing area.
This accident w as not t he subject of an on-site investigation.
20 Jan 87, CESSNA 182 G, VH-DGF, Private, YATTON
QLD, 00296 h rs
The pilot was approaching to land in 10 knot crosswind
conditions. Turbulence was encountered in the circuit area,
and t he pilo t elected to approach at 80 knots with 20
degrees of flap selected. After a normal fla re, the aircraft
floated for half the 61 0 met re st rip before touching down .
T he pilot applied heavy braking, but was unable to stop t he
a ircraft within the confines of the strip. Damage was sust ained as the aircraft passed through t hree drains.
The approach speed was h igher t han required for the existing condit ions . The strip slop ed down in t he direction of
landing and it is probable that a t ailwind existed at the
time of landing.
04 Ma r 87, PIP ER 31, VH-PNL , Airline t ra nsp ort, CAPE
FLATTERY QLD, 18000 hrs
The aircraft was engaged in t he transfer of passengers from
Cape Flattery t o Cooktown . It was observed to overshoot
from the first approach and to carry out a low level circuit
subsequently landing w it h the gear ret racted.
The pilot reported t hat during t he circuit following the
missed approach, he was required to adjust t he circuit pattern beca use of heavy rain in the area, a nd as a consequence flew a tighter than normal circuit. He also stated
that during the circuit he was interrupted by rad io conversations with another aircraft which was approaching Cape
Flattery.
An inspection of the aircraft revealed that the gear was in
the locked up position and no damage had been caused to
the main gear doors. No fault was found wit h the land ing
gear system that could have caused it not to extend when
correctly selected down. The pilot believed that it was possible that when moving t he gear selector lever to the down
pos it ion he had not moved it fully down. He does not recall
checking tha t t he gear down indicator lights illuminated.
05 Mar 87, GOVT.AC N24-A, VH-FCX, None, NOOSA QLD,
00000 hrs
A person who had previo usly held a Commercial Pilot
Licence gained entry to the aircraft and was able to start
the e ngines. The aircra ft then apparently rolled forward
a nd collided wit h a d isused fuel ta nker.
At about 0710 hours in t he morning the regular pilot
arrived t o find t he aircraft embedded in the side of the
tanker wit h t he engines still oper ating at low power . The
per son was subseque ntly located, by police, as leep on the
s ide of a nearby r oad.
11 Mar 87, BEECH C9 0, VH-FDP, Comme rcia l ,
CHARLEVILLE QLD 150NW, 11185 hrs
The pilot had been advised by the property owner to land
on a strip about two kilometres from the homestead instead
of t he usua l strip. The available strip length w as 1400
metres which was a dequate for the operat ion. The pilot
repor ted t hat when the a ircraft became low during the later
stages of the approa ch, he applied power, but realised t hat
the ma in wheels would probably pass thr ough tall grass
near t he t hreshold . J ust prior to touchdown, the pilot heard
and felt a loud bang. Immediately after touchd own, the aircraft adopted a left wing low attitude before the propeller
blades of t he left engine and left wing tip contacted t he
ground. The aircraft slewed th rough 90 degrees to the left
and ran off t he strip .
The investigation revealed that when t he landing gear was
allowed to pass through the long grass in the undershoot
a rea, it struck a concealed mo und of earth , seven met res
prio r to t he t hreshold . The impact caused the left oleo leg
to become detached from t he aircraft.
18 Ma r 87, PIPER PA44-180, VH-KHG, Commercial ,
HERBERTON QLD, 11500 hrs
Shortly after touchdown the nosewheel struck a 20 centimetre high anthill. The downlock latch on the nosegear was
broken a nd when the nosewheel entered a slight depression,
some 145 metres further along the ground roll, the nosegear
colla psed.
The pilot had overflown the strip during the approach.
However, due to t he heigh t of the grass on the strip the anthill would h ave been difficult to sight from t he air.
02 Apr 87, BRITTEN NOR BN2-A21, VH-SBH, Commercial, MABUIAG IS QLD, 07256 hrs
During the later stages of the approach the aircraft developed a higher ra te of descent than desired. The right main
gear subsequently struck a sand filled drum which was
located just short of t he threshold lip. The impact resulted
in the right wing being buckled and one of the, right engine
mounts fracturing. The pilot reported tha t he did not
believe that t he land ing was heavy and as a consequence
did not discover the damage on a subsequent superficial
inspection before cont in uing the flight.
The approach was flatter than normal and into a 20 to 30
knot wind. On late final the aircraft encountered a
downdraught and the pilot d id not a rrest t he rate of
descent, resulting in the touchdown occurring prior to the
t hreshold.
07 Apr 87, CESSNA T337 B, VH-DPX, Commer cia l, MAER
ISLAND QLD, 02028 hrs
The pilot reported t hat he h ad difficulty obtaining effective
braking during the landing roll, d ue to a grassed, wet strip
surface. He was able to initiate a groundloop near the end
of the landing roll but the aircraft drifted sideways off the
side of the strip p rior to the upwind threshold.
Ver y heavy rain had fallen during t he previou s night and
up unt il 30 minutes prior t o the landing, and there were
a reas of standing water on t he st rip. The airstrip was not
suitable for the intended operat ion.
09 Apr 87, CESSNA 337, VH-RDY, Senior comme rcial,
MAER ISLAND QLD, 01890 hrs
On the night prior to t he accident heavy rain had fallen in
t he area. The pilot stated that he carried out an inspection
of the centre section of t he strip prior t o departure and
found it to be suitable. This inspection did not include the
last 150 metres of the strip, in the proposed direction of
take-off. The area used for t he take-off roll was to one side
of the centre of the st rip, where the grass cover varied substantially in length a nd density.
During the t a keoff run the a ircraft entered a patch of water
approximately 150 metres before the upwind end, causing
the airspeed to rapidly decay from 65 knots to 40 knots.
The pilot elected to continue the take-off and overran the
strip before encountering t hick vegetat ion.
13 Apr 87, CESSNA 182 K, VH-DQR, Private, MT ISA QLD
240SSW, 001 75 hrs
Shortly a fter what was reported by the pilot as a normal
landing the nosewheel fork failed. This a llowed t he
nosegear strut to dig into the strip surface and resulted in
the aircraft overturning.
The nosewheel fo rk failure was found to have been caused
by overload forces and there was no evidence of any preexist ing defect.
0 7 Apr 87, ROLLASON BETA STANDARD, VH-IWA, P rivat e restricted, KOORALBYN QLD, 00128 hrs
It was reported by a wit ness that the aircraft bounced several times on landing and ran off the strip, collapsing t he
the maingear.
The accident was not reported by the pilot and the pilot
and wreckage were not locat ed until some five months after
the accident.
The pilot stated that he had been taxiing the a ircraft to
keep it serviceable. Whilst taxiing with t he tail off the
ground, the a ircraft began to bounce u ncontrollably. He
said, t hat in the interests of safety, he applied full power,
took off and flew a circuit. During the su bsequent landing,
the aircraft bounced, causing the landing gear to collapse.
Following t he accident he removed t he w reckage to a farm
fo r storage.
This accident was not the subject of a n on-site investigation.
04 May 87, CESSNA 162 M, VH-UFU, Senior commercial,
BRIBIE ISLAND QLD, 02160 hrs
During a fly ing training sor tie t he instructor simulated an
engine failure by moving the mixture control to the idle cut
off position. The student closed t he throttle and pulled t he
carburettor heat on, the instructor t hen moved the mixture
Aviation Safety Digest 136
I
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�control to rich. During the descent the throttle was opened
twice. Prior to commencing a go-around, at about 100 feet
above ground level, the student moved the carburettor heat
control to cold. At about 200 feet, on climb, the instructor
simulated another engine failure by again moving the mixture control to idle cut off. As soon as the student lowered
the nose of the aircraft the instructor moved the mixture
control to rich, with the throttle open. However, there was
no response from the engine and the aircraft was
subsequently landed in swampy terrain.
No mechanical engine defect was found and tests carried
out revealed that the engine should have been capable of
operating normally. Atmospheric conditions at the time of
the accident were conducive to moderate carburettor icing
at cruise power and severe icing at descent power. The carburettor heat control was not operated in accordance with
the manufacturer's instructions.
01 Jul 87, PIPER PA36-375, VH-PXZ, Commercial, OAKEY
QLD 26S, 01276 hrs
The operator of the aircraft had contracted to spray 160
hectares of barley with weed killer. On arrival over the
property, the pilot flew an inspection orbit and commenced
spraying the first paddock towards some tall trees and a
powerline. After this first pass the aircraft was pulled up
into a procedure turn before diving steeply over the same
obstacles, in the reciprocal direction. When the aircraft was
clear of the obstructions, the pilot attempted to level the
aircraft for the next spray run. However, the aircraft continued along its established flight path until striking the
ground in a pronounced nose high attitude. The impact
damaged the propeller, spray booms and landing gear.
Chemical sprayed over the windscreen depriving the pilot
of forward vision, and he was unable to control the subsequent landing run sufficiently to prevent the aircraft
from broadsiding.
The aircraft was being operated at a weight in excess of the
Agricultural Gross Weight and at a relatively slow airspeed.
During the pullout from the dive, the load factor ('G'
loading) applied to the a ircraft caused an aerodynamic stall.
The pilot was una ble to effect a recovery at such a low
altitude.
07 Aug 87, VICTA 115, VH-RQB, Commercial, KAGARU
QLD, 03181 hrs
After takeoff the aircraft was flown to the local training
area where upper air sequences were carried out. Following
their successful completion the pilot was instructed to carry
out a practice forced landing. The first attempt resulted in
a significant undershoot and the aircraft was climbed to
2500 feet for a further attempt. On the second attempt the
aircraft was placed in a position too high and too close to
the proposed landing strip, so the pilot under check decided
to fly an 'S' turn to lose altitude. During this manoeuvre the
aircraft became grossly misaligned with the strip, the stall
warning horn was sounding intermittently and the
instructor instructed the pilot to go-around. However, the
pilot banked the aircraft steeply to the left to a lign it with
the strip, the aircraft began to roll rapidly to the left and
despite the application ·Of right rudder and full power it
struck the ground. The nosegear a nd left maingear collapsed and the aircraft came to rest after a ground run of
39 metres.
07 Aug 87, PIPER 34 200, VH-SMM, Private,
CALOUNDRA QLD, 01500 hrs
Shortly after touchdown, the gear unsafe warning horn
sounded and the red gear unsafe warning light began to
fl ash . The right wing slowly lowered and the aircraft
veered to the right of the strip before coming to rest.
An inspection revealed that the right maingear had collapsed because of the fatigue failure of the maingear side
brace attachment stud. The fatigue cracks on the stud
initiated in rough machine tool marks in the radius between
the s hank and the lug.
x / Aviation Safety Digest 136
13 Aug 87, DE BAV DHC2-MK1, VH-HQE, Commercial,
HAYMAN ISLAND QLD, 05300 hrs
The pilots departure from Shute Harbour aerodrome had
been delayed and he was running late for his arrival at
Hayman Island. During the short flight he noticed that the
cruising indicated airspeed was slightly less than normal,
but attributed this to the possibility of water in the pitot
system, a problem that he had encountered the previous
day in another aircraft. On touchdown for the water landing, the pilot realised that the wheels were still extended.
He attempted to prevent the floats digging in but the left
wing struck the water before the aircraft came to rest.
This accident was not the subject of an on-site investigation.
23 Aug 87, PIPER 28 140, VH-CWE, Private, NOOSA QLD,
01034 hrs
The pilot was taking part in a flying competition consisting
of several flying sequences flown from the right hand seat
and monitored by a safety pilot/ adjudicator occupying the
left hand seat. The sequences included a practice forced
landing that was commenced from the upwind end of the
strip at an altitude of 1500 feet. This sequence was to be
conducted without the use of the aircraft instruments.
Accordingly all the instruments, including the stall warning
indicator, but with the exception of the tachometer and the
vacuum gauge, were covered with a piece of cardboard.
The pilot stated that he set the aircraft up in a glide for
runway 29. Approaching over a tidal lake, artd on late final,
he realised that the pilot had not adequately compensated
for the wind and an undershoot was developing. The safety
pilot said that he noticed the rate of sink increase rapidly
on late final and when the pilot at the controls did not
apply power, he called for a go-around and applied power.
However, the mainwheels contacted the water and the aircraft nosed over coming to rest inverted in the shallow
lake, 150 metres prior to the runway threshold.
13 Sep 87, CESSNA 172-RG, VB-KOS, Private,
TOOWOOMBA QLD, 00153 hrs
The pilot was manoeuvring the aircraft on the apron to
park adjacent to another parked aircraft. Whilst making a
right turn he was observing the other aircraft which was to
his right, when the left w ingtip struck a corner post of the
a irport boundary fence. The pilot had observed the fence
post prior to commencing the turn and had assessed that
there would be adequate clearance for the manoeuvre. However, he failed to continue monitoring t he clearance with
the post during the turn.
14 Sep 87, BEECH A36, VH-TLB, Private, GOONDIWINDI
QLD 76WNW, 00110 hrs
The pilot had landed at the strip on a number of previous
occasions, but this was the first time in t his aircraft type.
To give himself more time t he pilot made a longer than normal final approach. At about 100 feet above the ground,
with the airspeed at about 65 knots, t he aircraft began to
sink. The pilot applied full power to commence a go-around
and as the nose pitched up, the left wing dropped. The pilot
did not prevent the nose of the aircraft pitching up, t hus
aggravating the almost stalled condition of the aircraft.
Power was then reduced and the aircraft landed heavily in
a wheat paddock along s ide the strip and s lid sideways as it
came to rest.
23 Sep 87, AEROCDR 500 S, VH-MEH, Commercial,
CHARTERS TOWERS QLD, 01350 hrs
The pilot had been conducting a six and a half hour low
level sur vey flight. He stated t hat on joining t he circuit, at
the completion of thE: flight, he lowered the landing gear
and obtained a gear down indication. The gear indication
was again checked on final approach but during the subsequent landing roll, as the nosewheel was being lowered to
the runway, the landing gear handle in t he cockpit sprung
to the up position. The landing gear retracted and the a ircraft slide to a halt on its undersurface.
An inspection of t he a ircraft could find no pre-impact
defect with the landing gear or its systems which could
have contributed to t his inadvertent retraction. The landing
gear was found to be capable of normal operation. The
reason for the selector deselection remains undetermined.
19 Feb 87, CESSNA 172 M, VH-UGK, Private,
BANKSTOWN NSW, 00107 hrs
The pilot reported t hat during the takeoff roll the aircraft
was slow to accelerate. At about 50 knots the aircraft
became airborne in a nose-high attitude, and t he pilot
experienced difficulty in lowering the nose. Shortly afterwards the aircraft stalled, the left wing dropped and the
aircraft turned through about 120 degrees before impacting
the ground. It was determined that t he takeoff had been
conducted with the flaps in the fully extended position.
The pilot had not previously flown this particular aircraft,
a nd was not aware that a flap position indicator was fitted.
He had judged the takeoff setting by watching the flaps
extend, and had then released the selector, expecting it to
be spring-loaded to the neutral position. However, the
centering spring was broken and t he flaps continued to full
extension. The aircraft was found to be about 57 kilograms
above the maximum permitted all-up-weight, and the centre
of gravity was close to the rear limit. It was evident that
the pilot was surprised by the aircraft attitude and the
unusually high control column forces required after takeoff,
and was unable to react to the situation in time to avoid
losing control of the aircraft.
23 Feb 87, PIPER 30, VB-CON, Commercial,
BANKSTOWN NSW, 12800 hrs
During a training sequence, the pilot in command simulated
a failure of the left engine. The pilot under check correctly
identified the failed engine, and applied full right rudder to
counter the effects of yaw. The flight then continued normally, but the crew were later unable to obtain a down and
locked indication for the landing gear. An inspection from
another aircraft revealed that the gear was only partly
extended, with the nosewheel turned to the right. After all
efforts to lower the gear were unsuccessful, a safe
wheels-up landing was made. It was later discovered that
there was a rigging fault in the nosewheel steering and rudder system. This had allowed a roller, which normally
engages in a channel to centre the nosegear during retract ions, to move outside the channel when full right rudder
was applied. This had resulted in jamming of t he nosegear.
26 Feb 87, PIPER 25 235, VH-BCJ, Private, WAGGA NSW,
01000 hrs
When the pilot arrived at his planned destination, he was
unable to obtain a down and locked indication for the
nosewheel. Both normal and emergency means of lowering
the gear were employed, but without success. A diversion
was made to a more suitable aerodrome, where a safe landing was made with the nosegear ret racted.
It was determined that the hinge on the left door of the
nosegear assembly had seized because of corrosion. On the
previous retraction, the door linkages had been forced out
of position in such a manner that the gear doors were
jammed closed. All required maintenance and inspections
had been certified as being completed, and it was not possible to determine how the hinge had become corroded.
26 Feb 87, MOONEY M20 J, VH-IJL, Commercial, WEE
WAA NSW, 01200 hrs
When preparing for the return leg of a charter flight, the
pilot discovered that the engine starter motor would not
engage. He elected to hand-start the engine, and briefed t he
passenger on the operation of the controls. No wheel chocks
were employed. When the engine started, the aircraft commenced to move and the passenger's efforts to control the
aircraft were ineffective. After travelling about 20 metres
the aircraft ran into a ditch and the engine stopped after
the propeller struck the ground.
08 Mar 87, BELLANCA 8-KCAB, VH-SFK, Private
restricted, SCHOFIELDS NSW lE, 00922 hrs
The pilot intended to conduct a practice aerobatic flight ,
and had arranged .for an observer on the ground to monitor
and assess his performance. The planned sequence was commenced, but the observer noted that the second manoeuvre
was not completed satisfactorily, and the aircraft apparently stalled while inverted. After recovering from this sit uation, further manoeuvres were carried out. Other
witnesses suggested that the entries to some of these
manoeuvres were performed at higher 'G' loadings than
normal. The aircraft subsequently entered a spiral dive,
which was continued without any apparent effort being
made to effect recovery. The aircraft maintained the spiral
until it collided with power lines, then impacted t he ground.
A fierce fire broke out and consumed the wreck.age.
A detailed investigation failed to discover any defect or
malfunction with the aircraft or its systems which might
have contributed to t he accident. The pilot had been in current practice for aerobatic flight, and tbere was no evidence
of any physical illness or incapacity which might have
affected his ability to control t he aircraft. However, it was
evident that the aircraft was not under control during the
spiral dive. It was considered possible t hat the pilot might
have lost consciousness as a result of either a rapid
increase in 'G', or sustained high 'G' loads applied during
the preceding aerobatic sequence.
11Mar87, MOONEY M20 J, VH-UDD, Commercial,
BANKSTOWN NSW, 01003 hrs
As part of a refresher check on the aircraft, the instructor
required the pilot to use the manual system for lowering
the landing gear. After turning the crank handle the
recommended number of turns the gear down light did not
illuminate. The pilot continued to rotate the crank handle a
few more turns and a loud bang was heard, following which
there was little resistance to crank handle movement. However, the gear down light still did not illuminate although
the visual gear position indicator in the cockpit did indicate
that the gear was in the down position. The gear actuator
circuit breaker was reset and the gear selected up; the gear
did not retract but the gear unsafe light illuminated. All
further attempts to obtain a gear down light were unsuccessful. Observations made from another aircraft and by
persons on the ground indicated that the gear was down
and locked. The aircraft was diverted to Bankstown and the
gear collapsed immediately after touchdown.
A fault in the gear indicating system prevented illumination
of the gear down light when the gear reached the down and
locked position on the initial manual extension. When the
crank handle was wound further, an overload failure of the
actuator housing occurred. The gear was unlocked when the
up selection was made but the damaged actuator prevented
either retraction or safe extension. The actuator has a vital
function in retaining the gear in the down and locked position as it pre-loads the landing gear braces in an overcentre
position. Once the actuator was damaged, gear collapse on
landing was inevitable.
14 Mar 87, PIPER 32 300, VH-PWD, Private, COOTS
CROSSING 3S, 04500 hrs
The aircraft had not been flown and had stood in the open
for about two months. Some 20 minutes after departure the
engine commenced to run roughly, and the pilot elected to
divert to the nearest suitable aerodrome. Shortly afterwards, t he engine backfired severely and black smoke
entered t he cabin through an air vent. The engine
subsequently stopped completely and the pilot was committed to a forced landing on unsuitable terrain. The gear collapsed and the aircraft collided with two fences before
coming to rest. On vacating the aircraft, the pilot discovered that a fire was burning under the cowls on t he
right side of the engine. The fire was extinguished by the
pilot and passengers.
The cause of the engine failure could not be determined.
How~ve r, the insulation of both magneto coils was badly
deteriorated. It is considered likely t hat during t he period
that the aircraft was inactive, moisture accumulated in t he
magnetos. This moisture, together with the deteriorated
insulation, probably caused the magneto to misfire and fail.
The fire developed in the engine bay after severe backfiring
caused the exhaust cluster on the right hand side of the
engine to separate from the muffler. The hot exhaust gases
then ignited t he fibreglass cowling and the melting resin
emitted t he black smoke which entered the cabin via the
hot air vent.
Aviation Safety Digest 136
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�r
17 Mar 87, PIPER PP60·600, VH-NOA, Senior commercial,
ARMIDALE NSW, 04220 hrs
Shortly after touchdown the left wing began to drop and
the aircraft veered off the runway. It came to rest after colliding with a runway light and a culvert. Inspection
revealed that the castellated nut from the left gear torque
link pivot bolt was missing. This allowed the lower torque
link to rotate with the wheel and separate from t he upper
torque link.
It was evident that a split pin which should have locked the
castellated nut had not been in place for a considerable
time, thus allowing the nut to work loose. However, the
reason the pin was not in place could not be positively
established.
31 Mar 87, BEECH 58-TC, VH-FTZ, Commercial,
TAMWORTH NSW, 16830 hrs
On arrival at the destination aerodrome, the pilot was
unable to obtain a down and locked indication for the landing gear. He noted that when the gear was selected, there
was an abnormal noise, and the gear motor only ran for a
few seconds. On a subsequent re-cycling, a down and locked
indication was obtained, but the pilot not iced a strong smell
of hydraulic fluid. A diversion to a more suitable aerodrome
was made, where a flypast confirmed that the gear
appeared to be extended. The gear warning horn did not
sound when the t hrot tles were closed. However, the pilot
was unable to move the emergency gear handle from its
stowed position when he decided to use this device to
ensure the gear was in fact down.
During the ground roll, following a smooth touchdown, the
right main gear collapsed. The investigation revealed that
the right gear up-lock roller was seized. The pilot did not
detect this fault during the pre-flight inspection. The landing gear braze rod, the push rod between the actuator and
landing gear, was bent and the relevant gear position
microswitch was incorrectly adjusted, resulting in a premature landing gear down and locked indication. The landing
gear manual extension handle could not be moved because
of an incorrectly fitted trim panel. All these mechanical
defects were a consequence of inadequate maintenance.
14 Apr 87, CESSNA 210 K, VH-CHL, Private, DUBBO
NSW, 01000 hrs
The pilot intended to conduct a series of night circuits and
landings to maintain currency. On the second circuit, the
gear was selected down but failed to fully extend. All
attempts to lower the gear were unsuccessful. The aircraft
subsequently touched down with the partially extended
gear, which collapsed as the aircraft slid to a halt.
An inspection of the aircraft revealed that the failure of
left maingear hydraulic actuator resulted in t he loss of
hydraulic fluid and prevented completion of the gear extension cycle.
tided with powerlines and trees before falling to the grow1d
about 1.5 kilometres from the strip.
The powerlines consisted of three cables strung on individual poles. The span wh ich crossed the river was about 645
metres in length, and the height of the cables at the point
of collision was 35 metres above the river level. The
weather at the t ime was fine, with no restrictions to visibility. However, the wires were difficult to see against the
background, and t he pilot had not been aware t hat there
were any powerlines in the vicinity.
27 May 87, PIPER 28-161, VH-UZT, Senior commercial,
BANKSTOWN NSW, 04200 hrs
The pilot intended to conduct a short flight using Night
VMC procedures. Shortly a fter take off from runway 29C,
when the aircraft had reached a height of about 250 feet
above the ground, the engine commenced to run roughly ,
with an associated loss of power. The pilot applied carburettor heat, but was unable to regain climbing power. A
skidding left turn was carried out to position the aircraft
for a downwind landing on the aerodrome. Touchdown
occurred on a north-easterly heading near the eastern end
of runway 29 on an unlit area. The aircraft bounced and
power was applied to effect recovery. During the recovery
the a ircraft passed over a series of hangars before stalling
at a low height and landing heavily on a sealed taxiway.
An inspection of the engine revealed t hat the power loss
was caused by a mechanical failure of the ,right magneto
which affected the ignition timing.
23 Jun 87, BEECH 58, VH-PBU, Commercial,
BANKSTOWN NSW, 00366 hrs
The pilot had completed an endorsement on t he aircraft
type two days previously, and intended to carry out a
series of circuits with touch and go landings to consolidate
his training. During the landing roll following the first
touchdown, the pilot inadvertently retracted t he landing
gear when he attempted to raise the flaps. The aircraft slid
to a halt on the runway.
The instructor who had carried out the endorsement t r aining was not aware that it was company policy to prohibit
the conduct of touch and go landings for solo operations in
retractable gear aircraft. He had therefore not briefed the
pilot on this matter. The pilot stated that during his circuit
training in the aircraft, w hich consisted of a series of touch
and go landings, the instructor had raised the flaps after
each touchdown. The pilot had only limited exposure to
retractable landing gear aircraft types with the gear and
flap controls laid out in a sinillar fashion to this particular
aircraft.
20 Apr 87, PIPER 34 200, VH-SEN, Private, TRUNDLE
NSW 30E, 00680 hrs
When the pilot arrived at his destination it was a fter last
light and t here was no strip lighting available. The pilot
nevertheless decided to land, and although he believed he
had aligned the aircraft with the strip correctly, it was in
fact lined-up to the left of the strip. After touchdown the
aircraft ran through .a washout and the nosegear and left
ma ingear collapsed.
The pilot had been aware when he commenced the flight
that he would be unable to reach his destination before last
light. He had been reluctant to land at an alternate aerodrome, because he had been wearing old clothes and had no
money or credit cards wit h him.
This accident was not subject to an on scene investigation.
27 Jun 87, JODEL 09, VH-PBW, Private, COOMA NSW,
00240 hrs
The pilot reported that the takeoff and initial climb were
normal. However, a substantial loss of engine power had
occurred when the aircraft had just passed the upwind end
of the runway and had reached a height of about 400 feet.
The engine regained power briefly but then failed completely. The pilot considered that the terrain ahead of the
aircraft was unsuitable for a fo rced landing, and he elected
to attempt to return to the strip. By this time the aircraft
had descended to a height of about 200 feet. As the a ircraft
entered the turn it stalled and attempts by the pilot to
recover from the stall were unsuccessful. The aircraft
descended rapidly and struck the runway about 56 metres
from the threshold.
An investigation of the aircraft revealed no pre-existing
defects which could have contributed to the accident and
the cause of the reported loss of engine power remains
undetermined.
16 May 87, AUSTOR J5-190, VH-SCO, Airline transport,
GRETA NSW 3NNE, 09107 hrs
The aircraft was one of a group attending a vintage a ircraft
fly-in. It had been engaged on a photographic flight in company with another a ircr aft, in an area west of t he Hunter
River. During the return to the strip, the two aircraft
became separated. The subject aircraft was observed to
descend to a low height over the river, while apparently
tracking for a right base leg position. It subsequently col-
19 Jui 87, CESSNA Rl72 K, VH-SPJ, Private, COLLECTOR NSW 3N, 00380 hrs
The pilot was flying the jump a ircraft for a parachute club.
After having completed the fift h drop for the day, the aircraft was observed to make a high s peed pass, at an altitude of about ten feet above t he ground, over a group of
spectator parachutists . The aircraft then climbed steeply to
an estimated altitude of between 200 and 300 feet before
carrying out a wingover type manoeuvre. It then descended
xii / Aviation Safety Digest 136
'
'J
rapidly and impacted the ground in a slightly nose low, left
wing low attitude, before nosing over and coming to rest 56
metres from the point of impact. The pilot was trapped
inside the wreckage and the efforts of would be rescuers
were thwarted by a fire which rapidly engulfed the aircraft.
An examination of the wreckage fai led to reveal any preexisting mechanical fault. It was reported that the pilot had
carried out similiar manoeuvres on previous occasions, and
had been counselled, about these activities, by the senior
instructor at the parachute club.
06 Aug 87, CESSNA 180 G, VH-MJC, Private,
TENTERFIELD NSW 15S 02526 hrs
The aircraft had been parked in the open and was exposed
to a heavy frost. The pilot and his son attempted to clear
ice accumulations from the top surfaces of the aerofoils by
t hrowing warm water over them. Some 20-25 minutes
elasped between the ice clearing operation and the takeoff
attempt, during which time the aircraft was taxied to t he
airstrip and a second passenger emplaned. No further
checks were made for new accumulations of ice.
Following lift off, the aircraft commenced an uncommanded
t urn to the right. By the use of full left aileron and left rudder, the pilot was able to regain some directional control,
but could not prevent the aircraft from striking boulders on
the side of the strip. During the subsequent ground slide,
the fuel system was broached and the aircraft was
destroyed in the resulting fire.
Post crash inspection of the aircraft revealed that the rudder had been fouling the elevator control, thereby preventing adequate control travel, for continued flight under the
existing conditions.
11 Sep 87, PIPER 28 235, VH-FAR, Private, KULPRA STN
NSW, 00300 hrs
The purpose of the fligh t was to return to Underbool after
visiting friends and rel atives at Kulpra Station. On departure from Underbool the aircraft carried 136 litres of fuel,
68 litres in each main tank, the t ip tanks were empty. The
flight to Kulpra was conducted using fuel from the right
main tank.
The pilot stated that at an altitude of about ten feet after
lift-off, the engine failed. The aircraft was landed back on
the strip, heavily on the nosewheel, and the nosegear
subsequently collapsed. The pilot reported t hat on inspection the fuel tank selector was positioned to draw fuel from
the empty left wingtip tank instead of the left main tank.
12 Sep 87, CESSNA 182 H, VH-PQB, Private, BOXTON
PARK NSW, 00093 hrs
The pilot reported carrying out a normal approach to runway 34 in light and variable wind conditions. The aircraft
bounced on first touchdown and then landed heavily on the
nosewheel. Sever al more bounces occurred before the aircraft came to rest. The pilot taxied the aircraft back to t he
parking area where he found that the propeller blades had
been bent.
After the initial touchdown the pilot had attempted to correct the bounced landing by pushing the control column
forward.
17 Sep 87, AIRPARTS FU24-954, VH-MYW, Commercial ,
BRAIDWOOD NSW 20S, 24000 hrs
The pilot was operat ing from an agricultural landing area.
During the takeoff run the left mainwheel struck a vehicle
tyre, t hat was being used as a strip marker. The tyre was
flung into the air and struck the left stabilator caus ing it to
jam in about the neutral position. As t here was insufficient
strip remaining to land the aircraft and bring it safely to a
halt, the pilot decided to continue with the takeoff. The
pilot subsequently landed t he aircraft in a paddock three
kilometres from the point of departure. During the landing
roll the aircraft struck a fen ce.
The pilot had commenced the takeoff from the left side of
t he strip because the centre area was rough. The tyre
struck by the aircraft was difficult to see as t he white
paint on it had worn off, and it was partly obscured by
clumps of long gr ass.
20 Sep 87, CESSNA 210 M, VH-TIU, Private, MT SANDON
22N, 00600 hrs
The pilot stated that he carried out a normal circuit at his
dest ination. During the landing roll he selected the flaps up,
and then inadvertently selected the landing gear up before
realising his mistake and select ing the gear (iown again. The
gear up selection occurred just as the aircraft was travelling over a hump in the strip and it is believed that this,
combined with the pilot holding up elevator, caused t he
weight of the aircraft to come off the wheels. This resulted
in the landing gear safety switch becoming ineffective and
the gear commencing the retraction sequence. When the aircraft came to rest the nosegear was fully retracted, the left
maingear was partially retracted and the right maingear
was still down and locked.
Subsequent inspection and testing of the landing gear system did not reveal any faults that could have contributed to
the occurrence. The pilot stated that he believed he had
mistakenly applied the after-takeoff checks instead of the
after-landing checks and had selected the gear up instead of
opening the cowl flaps.
This accident was not the subject of an on-site investigat ion.
31Mar87, PIPER 28 140, VH-PBR, Commercial, SWAN
HILL VIC, 13000 hrs
The student was being instructed in crosswind techniques,
and several circuits and landings had been completed without incident. On the final circuit a normal approach and
touchdown were made, but during the landing roll the right
wing lowered and the aircraft swung through 90 degrees.
Initial inspection found that the lower torque link bolt on
the right gear had failed, allowing the wheel assembly to
detach.
Engineering investigation revealed that the torque link bolt
was of defective manufacture in that stress raisers existed
near the thread root. This condition resulted in a slow progressive fatigue fracture originating from the stress raisers.
There is no inspection requirement for this bolt and the
defect is considered an isolated case.
14 Jun 87, AUSTER J5 P, VH-BYW, Private, BALLIANG
VIC 2SE, 00390 hrs
The pilot was carrying out practice circuits for type familiarisation. Landings were being made into wind and on the
first touchdown the aircraft bounced and the pilot carried
out a go-around. On the next approach, the aircraft bounced
on touchdown to about 10 feet above the ground, and the
pilot held the elevator control back and opened the throttle
rapidly, intending to go around. The engine failed to
respond and the aircraft landed heavily, collapsing the left
maingear.
No defect was found with either the engine or the failed
gear tubing that could have contributed to the accident. The
misjudged landing flare was probably a result of the pilot's
lack of familiarity with the aircraft type. The recovery was
initiated too late and the lack of response from the engine
was most likely due to the throttle being opened too
rapidly.
28 Jun 87, CESSNA 172-N, VH-TST, Private, TYABB VIC,
00205 hrs
The taxiway for the particular strip is a continuation of the
gravel centre section of the strip. The taxiway then makes
a right angled turn. After a normal landing the pilot proceeded straight ahead, along the taxiway but failed to negot iate the turn. The aircraft entered a ditch and the left wing
struck the ground.
No fault was found with the aircraft's brake or steering
systems that could have contributed to the accident. Insufficient attention was paid to the operation of the aircraft
and t he turn was attempted at too high a speed.
12 Sep 87, BEECH V35 B-MK2, VH-ILY, Private, MITTA
MITTA 3.5NW, 00200 hrs
Upon arrival at Mitta Mitta the pilot performed a touch and
go on the 1000 metre long gravel strip, before approaching
for the full-stop landing. After touchdown, the aircraft
veered to t he right but was repositioned on the centreline
within a short distance. However, it again veered to the
right and departed the hard packed gravel surface of the
Aviation Safety Digest 136 / xiii
�strip and entered an area of long, damp grass. The pilot
was unable to control the direction of travel and the aircraft encountered a drainage ditch, an earth mound and a
fence before coming to rest with its noseleg collapsed.
No fault was found with the aircraft systems that may
have contributed to the accident. The pilot had not flown
the aircraft for 18 months and it is probable that the veer
was caused by differential braking in combination with the
damp, slippery grass on the sides of the strip. Weather conditions were fine and calm and were not considered a
factor.
•
•
08 Feb 87, CESSNA 210 N, VH-UFA, Commercial,
NUMBULWAR NT 19SW, 00855 hrs
The aircraft was to be ferried out of the path of an
approaching cyclone. Shortly after takeoff the pilot heard a
loud noise and the engine began to vibrate violently. He
turned the aircraft towards the only available area and
transmitted a "Mayday" call. During the turn, oil began to
stream over the windscreen from the rear of the engine.
The area selected for landing was about 600 metres Jong
and surrounded by low trees. The approach was high and
fast and the aircraft was still airborne as it approached the
end of the area. The pilot elected to stall the aircraft into
the trees.
The engine crankshaft was severely damaged on the No 4
and 5 big-end journals, consistent with a loss of oil, seizure
of the bearings and eventual failure of the connecting rods.
An explanation for the loss of oil supply to those bearings
could not be established, however, it is likely that the bearings were able to spin in their mounts which blocked off
those oil feeder holes.
This accident was not the subject of an on-site investigation.
05 Jun 87, BEECH 76, VH-RVS, Senior commercial,
PARAFIELD SA, 16350 hrs
When the pilot selected the gear lever to the down position ,
only the maingear responded. Attempts to lower the
nosegear were unsuccessful and the aircraft was landed
with the nosegear retracted. After touchdown both propellers were feathered. However, the right propeller did not
stop in the horizontal position and as the nose of the aircraft was lowered the propeller dug into the runway. The
right engine was torn from the aircraft and the aircraft
slewed to the right, damaging the left wing and propeller.
Investigation determined that the cause of the nose gear
binding, was inadequate lubrication of_ the nose ge~r door
hinges. This extra resistance resulted m the actuating mechanism coming out of alignment, which caused the gear to
jam. After the engines had stopped. rotating, th_e~e was
insufficient time for the pilot to adjust the pos1t10ns of the
propellers prior to the nose of the aircraft dropping onto
the runway.
01 Jui 87, CESSNA 210 M, VH-MCE, Private,
ARK.AROOLA SA, 00120 hrs
On arrival at the destination strip, the pilot assessed the
wind to be from the west at about 15 knots. He decided to
land on runway 03, using full flap, shortfield technique, but
during the flare the pilot found he was unable to counteract
right drift and the aircraft touched down on th~ nosewh~el.
The nosegear subsequently collapsed, and the aircraft skidded to a halt just off ttie right side of the strip.
The pilot said that during the approach he had been concentrating on his crosswind technique and had omitted to refer
to the airspeed indicator after crossing the threshold. When
he realised that the aircraft could not be aligned with the
strip, he considered initiating a go-around but the aircraft
struck the ground.
This accident was not the subject of an on-site investigation.
05 Jul 87, CESSNA 172-P, VH-WIQ, Commercial,
ANTHONY LAGOON NT, 00950 hrs
The pilot attempted to takeoff on an access track to a.
cattleyard. A southerly wind of about 15 knots necessitated
take-off to the south, towards the yard. The aircraft was
near gross weight and short-field technique wa~ used. A_t a
position 411 metres from the brakes-release ~omt, th.e nght
brake caliper assembly struck a 1.65 metre high section of
xiv/ Aviation Safety Digest 136
fence which formed the cattleyard. The right wing sheared
off outboard of the fuel tank when it hit an adjacent
three metre high fence cap. The aircraft then impacted the
ground in a steep nose down attitude and slid inverted for a
short distance before coming to rest. The aircraft had been
airborne for 155 metres prior to the first impact.
The pilot did not consult performance charts and underestimated the distance required for the aircraft to safely complete the take-off at this weight. There was sufficient room
available for the pilot to taxi the aircraft at least a further
300 metres along the track to the north before attempting
the take-off. A properly constructed, serviceable airstrip
was located within 500 metres of the cattleyard.
11 Jul 87, PIPER 28 181, VH-TXN, Private, ALICE
SPRINGS NT, 00160 hrs
After touchdown the aircraft bounced back into the air and
the pilot then raised the flap to the fully retracted position.
The aircraft contacted the runway nosewheel first, bounced
again and landed on its nosewheeel for the second time. The
nosegear subsequently failed and the aircraft skidded
straight ahead and came to rest on the runway.
The pilot had been advised by an instructor, on the day he
left on this trip, to use an approach speed of 80 knots.
However the Piper Operating Instructions for this aircraft
recomme~ds an approach speed of 66 knots. The aircraft
was flared at 80 knots and ballooned. The pilot said that he
was uncertain about landing at a major airport and apprehensive about this landing because of the possibility of
wake turbulence from a Boeing 727, which had departed
five minutes previously.
This accident was not the subject of an on-site investigation.
06 Sep 87, AMER AIR AA5-B, VH-MQW, Private,
INNAMINKA SA, 00484 hrs
The pilot decided to land on the shorter of two strips, using
a short field technique. Touchdown was made 75 metres
into the 470 metre strip, but the pilot was undecided
whether to apply maximum braking or to initiate a
go-around. Full power was applied an~ the airc~aft became
airborne for a short time before touching down m rough
terrain. It came to rest with both main gears collapsed, 282
metres beyond the end of the strip.
The pilot had not obtained data on the strip and th~refore
had not checked the landing performance chart which
would have indicated that the strip was too short for the
aircraft weight and prevailing conditions.
23 May 87, CESSNA 182 G, VH-DGI, Private, BOYUP
BROOK 26NE, 00227 hrs
The pilot was conducting a parachute drop from 9000 feet.
She reported that the cloud base was broken at about ~500
feet and that she climbed the aircraft through a break m
the cloud cover to reach the drop altitude. After the parachutist had exited the aircraft the pilot found a break in
the cloud cover and descended. However, she was then
unable to locate the airstrip and spent some time flying in
various directions until she decided to land and ascertain
her location. A paddock was selected and after an aerial
inspection a landing approach was conducted. The. aircraft
touched down about 150 metres into the paddock m
tailwind conditions. It then ran through a fence, across a
road and struck another fence before the nosegear leg collapsed. The aircraft then nosed over and came to rest
inverted.
The accident site is located about 47 kilometres south-west
of the Hillman Farm Airstrip.
After descending below the cloud base the pilot's reported
actions did not include basic procedures when lost. She
advised that when she could not establish her position, she
became confused and apprehensive and consequently picked
an unsuitably short paddock in which to land. The pilot had
only recently recommenced flying after a .3 year break, _and
had completed a biennial flight review pnor to conducting
these parachute drops. Although this review totalled almost
6 hours flying and covered many important sequences, the
instructor did not appreciate that the pilot had no crosscountry experience in at-least that time. Navigati?n techniques and basic actions if lost were not covered m the
review.
16 Jun 87, CESSNA 421 C, VH-URT, Senior commercial,
BAGGA WA, 04161 hrs
On arrival in the circuit area, the pilot elected to land on
runway 27. During the final approach to thal runway he
considered that the wind velocity favoured t he opposite
landing direction and carried out an overshoot, retracting
both the gear and flap. The pilot does not. recall lowering
t he gear at any stage during the subsequent circuit. Neither
he nor any of the passengers recall hearing the gear warning horn when the second stage of flap was extended on the
base leg. The aircraft was subsequently landed with lhe
gear retracted.
Investigation revealed that the gear and warning systems
were serviceable. Although the pilot used the checklist for
the first approach he did not backtrack the list after the
go-around, but instead relied upon his memory to initiate
the required procedures prior to landing.
Rotary Wing
03 Jui 86, BELL 47 G3Bl, VH-ANG, Commercial,
COLEMAN RIVER QLD, 03500 hrs
The helicopter was being used in a program of disease
eradication in cattle. After operating for about one hour,
the pilot flew to a boat anchored in the river and hovered
alongside it while signalling to the crew that the aircraft
would return in about two hours. As the helicopter left the
hover it was climbed to approximately 60 feet in a left turn
through 270 degrees. The aircraft was then descended to an
unnecessarily low altitude while gaining speed. Shortly
afterwards, as the aircraft approached the bank of the
river, the pilot realised that the aircraft was not responding
to control inputs as he had expected. He applied more collective control in an effort to avoid fl ying into the water,
but the rotor overpitched and the aircraft struck the water
at about 40 knots.
No defect was found that would have prevented normal
operation of the flight controls or engine.
28 Nov 86, HUGHES 2 269-C, VH-KLQ, Commercial helicopter, SCARTWATER QLD 00440 hrs
·The pilot was conducting cattle mustering operations.
Weather conditions at the time were very hot, with a 10 to
15 knot wind. The pilot advised that while flying downwind
at 30 knots and 80 feet above the ground, he commenced a
pedal turn to the right. After some 90 degrees the turn suddenly stopped and the aircraft sank rapidly to about 35 feet
above the ground. The main and tail rotors struck trees, but
the pilot was able to maintain control and fly the he hcopter
to a clear area, where a safe landing was made.
No defect was found with the helicopter or its systems
which may have contributed to the occurrence and the
reason for the loss of control, reported by the pilot, was not
determined.
This accident was not the subj ect of an on-site investigation.
17 Sep 86, AGUSTA 206-8, VH-LED, Commercial - helicopter, MANGALORE VIC 3NW 06924 hrs
The purpose of the flight was to film a moving train. Prior
to commencing the operation, the pilot made an aerial
inspection of the a rea and mentally noted the various
obstructions. On the second filming run the helicopter collided with power lines at a height of 33 feet above ground
level. The helicopter descended and struck the ground about
50 metres beyond the point of collision. It then bounced and
came to rest on its side.
The pilot was highly experienced in aerial photography and
survey operations. At the time of the accident, visibility
was reduced to less than 2 kilometres in light rain. One of
the poles supporting the power lines was hidden from the
pilot's view by a large tree. It was also possible that the
pilot had flown outside the area he had previously
inspected, as he had not been aware of the presence of the
particular set of wires.
27 Feb 87, HILLER UH12-E, VH-HJW, Commercial - helicopter, CHARTERS TWR 90SE, 06000 hrs
During the descent the pilot heard a loud bang, following
which the engine stopped. An autorotational descent was
carried out for a landing onto the clearest available area, a
dry river bed. The helicopter touched down with some forward speed on the soft sand, pitched forward and rolled
over.
An inspection of the wreckage revealed that a connecting
rod big-end had failed due to fatigue. These fatigue cracks
had initiated in the area of the recesses for the big end bolt
nuts, where production machining was found to be quite
coarse.
This accident was not the subject of an on-site investigation.
11 Apr 87, HUGHES 269-C, VH-HFC, Commercial - helicopter, CAIRNS QLD 130NW 00350 hrs
The pilot was attempting to bring the helicopter to a hover
in the lee of a hill, but found that there was insufficient
power to arrest the rate of descent. The aircraft struck the
ground and rolled over. The pilot reported that the conditions were very windy.
The helicopter was reported to have been operating normally prior to the accident. The pilot stated that in attempting to arrest the rate of descent he had inadvertently
overpitched the rotors at an altitude from which recovery
was not possible.
This accident was not the subject of an on-site investigation.
14 Jui 87, BELL 206 8, VH-PHA, Private - helicopter,
GAYNDAH QLD, 1800 hrs
The helicopter was heading in a westerly direction following takeoff from the pilot's property. The track was to take
the a ircraft directly over Mount Gayndah so the pilot
decided to track to the south of the mounta in to provide better terrain clearance. When the helicopter was abeam the
mountain, at about 500 feet above ground level, it struck
two power lines suspended between a pole on top of the
mountain and a pole 1100 metres to the south in the foothills. The pilot was unaware the aircraft had struck the
wires, but immediate ly lowered the collective and turned
the aircraft towards the only available cleared area.
Approaching the area it became obvious to the pilot that
the aircraft would not clear trees on the approach path and
he increased the collective. The helicopter cleared the trees
and turned right through 180 degrees before touching down
in a level attitude while travelling rearward. The landing
skids collapsed and the aircraft slewed to the right before
coming to rest.
The two 90 tonne breaking strain wires had been broken
when they were struck by the main rotor blades of the helicopter. The wires then severed the tail rotor drive shaft, a
substantial portion of one tail rotor blade and almost severed the tail boom just in front of t he vertical stabilisers.
22 Jui 87, HUGHES 269-C, VH-MZR, Commercial - helicopter, TOWNSVILLE 260WNW 02235 hrs
The pilot was making a landing approach, to an area not
norma lly used for helicopter operations, at the conclusion
of a stock mustering operation. The helicopter collided with
a single wire telephone line then landed heavily, rolling
onto its side as the skids collapsed.
The pilot reported that the wire was normally difficult to
see because of age discolouration and the long span between
poles. On this occasion he had forgotten that the wire ran
through the area and did not see it during the approach.
This accident was not the subject of an on-site investigation.
10 Mar 87, BELL 47G2, VH-KHK, Private, BALRANALD
90NE, 09700 hrs
The pilot reported that as he brought the aircraft into the
hover in preparation for landing, it sank to the ground from
a height of about 15 fe et. The tailrotor blades struck a
lygnum bush and the drive shaft sheared. The pilot indicated that the main rotor rpm had decayed, possibly from
over-pitching during the latter stages of the approach.
Aviation Safety Digest 136 / xv
�Operations had been conducted in gusty wind conditions.
When the pilot noted that the main rotor speed had decayed
to 2800 rpm, he applied more power but was unable to
arrest the rate of descent.
This accident was not subject to an on scene investigation.
18 Mar 87, HILLER UH12-E, VH-ECK, Commercial - helicopter, TAMWORTH NSW 4W 04448 hrs
The pilot had been carrying out crop spraying operations,
and was hurrying to return to his base before last light. He
was concerned with t he fuel state, and made an enroute
landing, where one of the passengers dipped the tank.
Believing that adequate fue l remained, the pilot took off
again, but shortly afterwards the engine lost all power. During t he subsequent autorotation, manoeuvring was necessary to avoid power lines. The helicopter then landed
heav ily and the main rotor blades struck and severed the
tail boom. It was determined t hat at the time of the accident the aircraft had been operating for 7 minutes longer
than the expected total endurance.
The pilot had not kept an accurate record of fuel usage, and
it was likely that his decision making processes had been
impaired by fatigue. It was probable that the helicopter had
been resting on sloping ground at the time the tank contents
were checked, resulting in an erroneous reading on the
d ipstick.
27 Jui 87, BELL 206 B, VH-PHX, Commercial - helicopter, BANKSTOWN NSW, 06020 hrs
One of the pilots was undergoing practice in engine failure
emergencies at night. The helicopter was equipped w ith a
"N ightsun" light, which was used to illuminate t he ground
below the aircraft. Fixed lights were a lso installed at the
edges of the helipad. During the third practice autorotative
descent, the Nightsun light was inadvertently ex tinguished
when the aircraft was about 300 feet above the ground. It
was turned on again by the time the aircraft had descended
to about 100 feet, and the remainder of the descent a nd
flare appeared to be normal. However , after touchdown the
aircraft became a irborne again, before touching down on
the heels of the skids while moving slowly forward. The
aircra ft rocked forward and the main rotor severed the tail
boom just forward of the t ail rotor assembly.
The s urface of the helipad had been softened by recent
rain, a llowing the heels of the skids to dig in slightly. This
probably accentuated the rocking movement which led to
main rotor blade contact w ith the tail boom. The type of
manoeuvre being performed requires a high level of skill.
Shou ld a slight error of judgement occur, there is little
opportunity for any corrective action to be success ful. It
has been recommended that t his type of training be modified to ensure that practice engine failure emergencies at
night are terminated at a safe heig ht above the ground.
17 Sep 87, BELL 47-G2, VH-KHK, Commercial - helicopter, HAY NSW 65W, 00830 hrs
The helicopter was engaged in the mustering of feral pigs
for a cull. After descending the helicopter to follow the pigs
into a cleared ·area, the pilot noticed that more power was
required to fly the aircraft. The aircraft was immediately
landed at the base area, where an inspection revealed damage to the leading edge of bot h rotor blades. The damage
was consistent with the blades striking small branches of
trees. The pilot reported that neither he nor his passenger
had been aware of the helicopter striking any objects.
11 Mar 87, HILLER UH-12E, VH-MJV, Commercial - helicopter, DARWIN NT 135SW 02734 hrs
The pilot was directing cattle through a gate when a cow
turned and began to walk back towards the helicopter. It
stopped in front of the aircraft before charging. The pilot
applied back cyclic and up collective in an attempt to avoid
the animal but the t ail rotor struck the ground. The helicopter began to yaw and the pilot landed the a ircraft immediately. It continued to yaw after the landing and the landing
skid assembly was substantially damaged.
The pilot was relatively inexperienced on the helicopter
type, having the majority of his recent experience on more
powerful and responsive types. On this occasion, t he rate of
xvi/ Aviation Safety Digest 136
cyclic application was too great and not compensated for by
the collective input.
This accident was not the subject of an on-site investigation.
09 Sep 87, HUGHES 269-C, VH-PSK, Commercial - helicopter, ANNA PLAINS 20S, 07330 hrs
Whilst mustering cattle near a holding yard, the helicopter
was being held in the hover in a 15-20 knot headwind.
Because some of the cattle broke away, t he pilot t urned
downwind to herd them back. As the aircraft rolled out of
the t urn it began to descend and t he pilot attempted to
arrest the sink by increasing collective. However, t he helicopter continued downward and impacted heavily on the
ground resulting in the tail boom being sheared off. It then
bounced into the air and began to yaw rapidly but the pilot
quickly and firmly placed it back onto the ground. When
the helicopter came to rest the occupants were able to extricate themselves from the wreckage.
The pilot misjudged the performance that could be expected
from the helicopter. When the machine was turned
downwind, the sudden loss of lift resulted in a descent from
which the pilot was unable to recover before the aircraft
collided with the ground. The pilot reported that he
believes he overpitched the main rotor during the recovery
attempt.
Gliders
24 Jan 87, SCHEMP STD.CIRRUS, VH-GGC, Glider,
KINGAROY QLD, 00490 hrs
During t he ap proach the pilot became aware that the aircraft was going to undershoot t he intended landing area. He
adjusted the approach, however, the aircraft landed short
of the aerodrome in a cult ivated field and struck an earth
bank.
Witnesses reports indicate that the air brakes had been
deployed prior to the glider t urning final. It is possible that
the pilot was distracted by the other aircraft and forgot
that the air brakes had been deployed during the approach.
This accident was not t he subject of an on-site investigation.
26 Sep 87, SCHLEICHER K7, VH-GQX, Glider,
BOWENVILLE QLD, 00269 hrs
The instructor st ated that after a normal flight a nd circuit
approximately h alf air brake was set for the approach.
Additionally d uring t he approach further air brake was set,
for a short period, to steepen the approach . When the
instructor then checked the indicated airspeed he observed
that it had reduced to less t han 45 knots. He stated that he
d id not close the air brake in time to prevent a heavy
landing.
This accident was not the subject of an on-site investigation.
24 Jan 87, SCHLEICHER KA7, VH-GNX, Glider,
WOODV ALE VIC, 00014 hrs
The pilot had conducted a soaring flight for an hour in part icularly turbulent conditions. The subsequent landing was
conducted with a light crosswind from the right. The pilot
misjudged the flare, and the aircraft ballooned to a height
of about 15 feet, w hile veering to the left. The pilot then
retracted the air brakes and the glider subsequently struck
the ground heavily in a slight nosedown attitude.
This had been the longest flight undertaken by t he pilot,
and the weather conditions probably resulted in stress and
fatigue. The landing fl are had been made with r apid, rather
than progressive, control movements. The pilot had then
lost directional control, a nd while he was attempting to
regain a normal glide attitude the a ircraft had s truck t he
ground in a shallow dive.
This accident was not subject to an on scene investigation.
30 Jan 87, GLASFLUGEL 206 HORNET, VH-GMU, Glider,
SADDLEWORTH 4NW, 00205 hrs
The pilot was attempting a 300km cross country flight.
After release from t he aerotow t he glider only achieved
3000 feet above mean sea level. As the flight continued no
further height gain was achieved and on descending to
below 2000 feet t he pilot decided to carry out an
outlanding. While t he glider was being manoeuvred in the
circuit, at about 50 feet above ground level, the right wing
dropped and struck the ground.
The pilot had selected a landing field when flying with
2000 feet indicated on the altimeter. He was unaware that
the terra in over which he was flying was 1000 feet above
mean sea level and thus only 1000 feet below the aircraft.
During the approach the aircraft became low and the airs peed decreased until the aircraft stalled at too low an altitude to a llow recovery.
01 Feb 87, BURKHART ASTIR CS, VH-GDZ, Glider, BOND
SPRINGS 4W, 00070 hrs
The pilot was carrying out local gliding in the Bond Springs
a rea attempting to achieve a flight time of five hours which
would qualify him for a Silver C certificate. He had flown
away from the vicinity of the airfield in search of lift . On
returning to the airfield he became aware t hat he would be
unable t o reach the airfield and selected the only suitable
area to carry out a la nding. The aircraft failed to make the
selected area a nd struck a tree during the approach,
subsequently impacting the ground on the right wing and
slewing t hrough 180 degrees before coming to rest .
08 Feb 87, GLASFLUGEL LIBELLE H201, VH-GYQ,
Glider, BOND SPRINGS 3N, 00520 hrs
While returning to the airfield the glider experienced a
deterioration of lift and the pilot decided to carry out a
landing on the Stuart Highway. The pilot observed two
vehicles on the road and attempted to warn them of his
intention t o land. The first vehicle stopped but a bus following, continued a long the roadway. The pilot decided to
land before reaching the bus. After touchdown the pilot
moved the glider to the side of the road but the left wing
struck a road sign then a tree. The glider slewed off the
road and t he landing gear was torn off.
The pilot was forced to accept a collision with known
obst ructions in order to avoid the bus. The countryside in
t he vicinity of the highway was considered unsuitable for
an outla nding.
This accident was not the subject of an on-site investigation.
22 Aug 87, BURKHART ASTIR CS, VH-IKG, Glider,
BORDERTOWN SA, 00050 hrs
The glider was being winch-launched from strip 36. During
the la unch, t he left wingtip dropped into lush vegetation
covering the strip. The glider rolled rapidly to the left
around the wingtip, until it was inverted. It impacted
heavily in this a tt itude and came to rest 96 metres from,
and 15 metres to the left of the take-off point.
A 15-20 knot north-easterly w ind was blowing at the t ime
and the right w ing was seen to lift as the left wing contacted a reasonably heavy cover of dandelions which were
30-40 centimetres tall. The pilot had activated the manual
release and the winch operator stopped the launch when
t he glider adopted the acute roll angle, but both of these
actions were too late for recovery to be achieved prior to
impact. Due to soggy conditions, the gliding club had not
used the strip for the previous 2 months, and had not mown
the surface prior to recommencement of operations.
06 Sep 87, BURKHART TWIN ASTIR, VH-KYN, None,
BEVERLEY WA, 00023 hrs
The pilot was carrying out a practice circuit. Although the
approach was good, the flare was initiated too high. The
pilot attempted to cor rect by lowering the nose, however he
was late in initiating the second flare. The aircraft struck
t he ground and bounced into a nose high attitude. The pilot
again lowered the nose which resulted in another bounce.
The gear finally collapsed after the third ground impact.
The instructor assessed that the pilot's performance on
earlier dual fli ghts that day was of a sufficiently high standard to authorise him to do a solo circuit. However, on this
circuit the flare height was misjudged and the technique
used to recover from the bounced landing was incorrect.
Ultralights
03 Jun 87, MAXAIR DRIFTER XP503, NOT REG, None,
HUNGERFORD QLD, 00200 hrs
The pilot had flown the aircraft to Hungerford to attend a
Field Day. The following morning he adjusted t?he aircraft
brakes and apparently decided to take the aircraft for a
test flight. After taking off from the local racecourse, the
aircraft climbed to about 150 feet above the ground before
descending to fly just above the tops of the trees . The flight
continued at this altitude until t he aircraft struck a single
wire power line and spun to the ground.
The pilot had discussed the presence of the wire with the
owner of the aircraft prior to taking off. However, the wire
was of small gauge and not easily discernible from the air.
29 Aug 87, DRIFTER XP 503, NOT REG, None, MERIMAN
QLD, 01000 hrs
On arrival at the property, the pilot landed the aircraft in
front of the homestead. A short time later he departed with
t he property owner on board for a cattle spott ing flight. On
returning to land, again in front of the homestead, the aircraft hit a single powerline, pitched nose up and fell to the
ground inverted. The pilot stated that he was not aware of
the presence of the powerline prior to colliding with it.
30 Sep 87, SKYCRAFT SCOUT MK 3, NOT REG, Student,
BABINDA QLD ION, 00838 hrs
The aircraft had previously had to be flown with t he control stick displaced to the right of centre in order to maintain a wings level attitude. The aircraft owner advised a
visiting ultralight pilot of the problem, w ho offered to
attempt rectification . After conducting a flight to experience the problem first hand, the pilot adjusted the right
wing warping wire and conducted another test flight. The
adjustment had improved the trim problem but still not
completely provided a fix. The pilot then readjusted the
right wing warping wire to its original condition and added
a D-shackle to the left wing warping wire to increase its
length. Another test flight was carried out and it was found
that the aircraft could only be maintained in level fligh t
when full right rudder and full right control stick were
applied. The aircraft was struck by a wind gust and the left
wing dropped, as no further control was available to correct
this situation, the pilot pulled a wing warping wire.
Unfortunately he pulled the right wire instead of the left
wire and was unable to correct his error before the aircraft
struck t he ground.
A subsequent inspection of the wreckage found that the
right wing warping wire was 19 millimetres longer than the
left. Also, all the dimensions of the right wing were slightly
larger than that of the left wing, resulting in the right wing
area being about 80 square centimetres greater.
17 Feb 87, SADLER VAMPIRE SV2, NOT REG, Private,
WILTON NSW, 13549 hrs
The pilot was completing a 50 hour test flying program on
the aircraft. Two previous sorties had been flown during
the day, without incident. On this occasion, the pilot was
conducting a glide approach, but when power was
re-applied to go around, the engine delivered some 400 rpm
less than normal. The pilot attempted to conduct a low level
circuit, however the engine power continued to decay on
the downwind leg. The turn onto base leg was conducted at
about 100 feet, and shortly afterwards all power was lost.
The aircraft landed heavily in a paddock.
A post accident test run and inspection of the engine found
that the power loss was caused by a spark plug failure.
This accident was not the subject of an on-site investigation.
31 May 87, MAXAIR DRIFTER, NOT REG, None,
TAYLORS ARM NSW, 00061 hrs
The aircraft had completed several successful flights during
the day. At the completion of a power off descent, the pilot
rapidly opened the throttle. The engine began running
roughly and t hen failed completely. During the subsequent
glide approach, for a forced landing, the aircraft collided
with powerlines which crossed a gully about 350 feet above
the ground. One line contacted the pilot's throat, inflicting
severe lacerations, and the aircraft descended to the ground
out of control.
Aviation Safety Digest 136 / xvii
�An inspection of the engine did not reveal any defects that
could have contributed to the occurrence. This particular
type of engine, which has inverted cylinders, floods quickly
with rapid advance of the throttle . This flooding with
unburnt fuel, swamps the spark plugs causing the engine to
fail.
25 Sep 87, ULTRALIGHT WINTON SAPPHIRE, NOT REG,
Unknown/not reported, DOYALSON AIR PARK
The pilot had borrowed the aircraft from his brother to
carry out some taxi training. He had previously flown
gliders . After making about 20 runs along the strip the aircraft became airborne, the pilot decided to continue with
t he takeoff as he was uncertain if the aircraft could be
stopped in the remaining available strip. The aircraft collided with trees at the end of the strip and became wedged
in the tree tops. The pilot escaped from the aircraft uninjured and had to climb down the tree to the ground.
This accident was not the subject of an on-site investigation.
16 Aug 87, THRUSTER GEMINI, NOT REG, Commercial,
WARRACKNABEAL VIC, 01640 hrs
It was the student's fourth flying lesson and the effects of
power were being revised. The student turned the aircraft
90° to the left onto downwind but when he attempted to
level the wings after the turn, the bank angle increased
from about 30° to 50°. The instructor took over the controls
and attempted to recover by applying right aileron, full
power and holding the nose up briefly. When the a ircraft
did not immediately recover, the instructor lowered the
nose but the aircraft s truck the ground, in a left wing, nose
low attitude, before full control could be regained.
After revising the effects of power, the engine speed was
set too low for the aircraft to sustain level turn. The
student maintained altitude by progressively applying up
elevator and the instructor did not notice the incorrect setting because speed was assessed with re ference to the
ground in a 20 knot tailwind. The instructor delayed t a king
over the controls, because he thought that the aircraft was
being subjected to mechanical turbulence generated by
trees, over which they were flying.
31 Jan 87, THRUSTER GEMINI, NOT REG, Other
(Foreign, Military, etc), KAPUNDA SA 7N, 00075 hrs
The pilot was carrying out his first cross country flight
over unfamiliar terrain. After passing over one of his
planned turning points he became concerned about the
aircraft's location and decided to follow a road back
towards the destination. Enroute the pilot descended the
aircraft to read a road s ign in an endeavour to establish his
location. However, the aircraft struck a power line and
subsequently collided with the ground.
This accident was not the subject of an on-site investigation.
Safet¥ contacts
Safety promotion liaison officers
Central Office
Telephone
Steve Small
062 686294
Flight Standards Division
Department of Transport and Communications
GPO Box 594
CANBERRA CITY ACT 2601
FACSIMILE: 062 497349
Bill Taylor
07 2531211
Flight Standards
Department of Transport and Communications
P.O. Box 600
FORTITUDE VALLEY QLD 4006
NSW
John McQueen
02 2187111
Flight Standards
Departme nt of Transport and Communications
P.O. Box 409
HAYMARKET NSW ·2 000
SA/ NT
Mike Greentree
08 2180211
Flight Standards
Department of Transport and Communications
G.P.O. Box 2270
ADELAIDE SA 5001
VIC/TAS
Mark Perrett
03 6622455
Flight Standards
Department of Transport and Communications
G.P.O. Box 1733P
MELBOURNE VIC 3001
WA
Sam Todhunter
09 3236611
Flight Standards
Department of Transport and Communications
G.P.O. Box X2212
PERTH WA 6001
Bureau of Air Safety Investigation
Central Office
P.O. Box 967
CIVIC SQUARE ACT 2608
FACSIMILE: 062 473117
Sydney Field Office
P.O. Box K237
HAYMARKET NSW 2000
Melbourne Field Office
Private Box 1
Exhibition Street Post Office
MELBOURNE VIC 3000
xviii /Aviation Safety Digest 136
QLD
Brisbane Field Office
P.O. Box 24
Adelaide Street Brisbane
BRISBANE QLD 4000
Adelaide Field Office
G.P.O. Box 1112
ADELAIDE SA 5001
Perth /Field Office
P.O. Box 63
GUILDFORD WA 6055
Aviation Safety Digest 136 / xix
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xxiv /A viation Safety Digest 136
DATE _ -/ _ -/ _ _ _ _
YEAR
WO HIGH-SPEED aircraft operating at low
altitude, crossed paths and collided. Wreck- age was strewn for about a kilometre in
both directions. Amongst the twisted fragments
of metal were the broken bodies of two pilots.
It happened near Townsville.
This collision was between members of the
same group of aircraft who were briefed, aware
and expecting to be in visual contact. The daily
risk of mid-air collision from incidental confliction is very remote in Australia, but the horrific results of a collision should keep every
aviator alert to the possibility. This article discusses some aspects of F-111 flying which
might interest all pilots, particularly lowaltitude operators - and assist their motivation for alertness and lookout at all times.
Is there a significant risk?
Since the introduction of the F-111 into the
Royal Australian Air Force and Australian airspace, there has been much concern voiced at
the risk of mid-air collision posed by this
35-tonne, supersonic, strike aircraft. Is the concern justified?
Yes!
Why? - because the F-111 has these
characteristics:
• camouflage
• very high speed
• relatively poor cockpit field-of-view
• poor manouevrability or conversely, high
momentum (by light aircraft standards)
• silent operations (no full reporting)
• operating in the heavily-used, low-altitude,
east-coast region
• high crew workload (at times reducing lookout effectiveness)
Yes, we should be concerned about collision
with F-lll 's. F-111 operators are as, or more
concerned about the remote possibility of
collision. Let us not single out the F-111 though
- many of the points apply equally to other
aircraft. For example, Ag pilots a lso operate in
the low-level, high-workload environment.
Each category of aviation has its own purpose
and needs. Procedures which increase awareness, decrease the chance of collision and
improve the safety of low level operations,
must be established.
�Aviation Safety Digest
Aviation Safety Digest
136
Such procedures must satisfy all concerned to
the maximum extent - and that brings us back
to t h e subject of F-111 mid-air collision r isk.
What can be done?
Let us examine the points previously raised:
• Camouflage - there is an operational reason
for the F-111 paint scheme. Hence the aircraft
is difficult to see when you are looking down
on it, over water, forest or dark backgrounds.
Additionally, the F-111 has a s mall frontal
area - making it difficult to detect if it's
coming towards you.
• Speed - the aircraft simply cannot be flow n
at low speed. The very high, even supersonic,
speeds that might be used in combat, create
noise and over-pressure (shock-wave) problems, that are not acceptable around our country side . The compromise is a cruise speed of
480 knots. Interestingly, a high cruise speed
results in a priority sector for crew lookout an aircraft with a crossing speed of less than
180 knots that is outside t he 20° sector (40°
cone), w ill not collide. So th e F-111 crew can
emphasise lookout in this front 40°. (Naturally
for operational training, lookout is practised
through 360°)
180kts
• Cockpit field-of-view by military standards, is
not good and is a fu nct ion of the aircraft's
design. However, by civilian aircraft standards, the view is not bad and crews are
trained to put maximum effort into lookout.
They are required to reach a high standard as
part of their operational t raining and this
includes special head movements and
co-ordination of lookout between pilot and
navigator as well as between aircraft in
formation.
• Manoeuvrability is also a function of air craft
design , mass and speed - and 35 tonnes at
480 knots has a great deal of moment um to
overcome. Thus its flight-path is very predictable and not easy to change, compared w ith
light aircraft. Turn radius varies w ith configuration, weather and operational requirements but two to three nautical miles is typical.
• The periodic high cockpit workload and high
groundspeed, make full reporting impractical.
These speeds would require an F-H 1 to be
almost continuously transmitting. Instead, to
advise other aviators of the presence of
F-lll's , NOTAMs are issued for each flight.
Flight service units ·broadcast the F-111
activity on appropriate area VHF frequencies .
They also advise F-111 cr ews of known conflicting traffic. Crews maintain a listening
watch on HF (the aircraft are not currently
fitted w ith VHF). F-111 crews adher e closely
to their advised track s and times.
• The area and a ltitude of operations are
governed by a few factors. Training requires
that crews fly against a variety of simulated
targets, day and night, in VMC and IMC, u sing
different a ttack profiles. Hilly terrain is pref erred to practice navigation and terrain
shielding (using terrain to mask the F-11 1
presence from 'enemy ' radars). Routes are
varied also to reduce the exposure of residents to the jet noise. Most sorties are conducted in the south-east of Queensland and
northern New South Wales - but they a re
periodically planned t hroughout Australia as advised by NOT AM. Cruising altitude is
generally above 10,000 feet agl and between
200 and 700 feet on a low-level sector. In the
target area, a 'toss' manoeuvre (a pull-up followed by a wingover back to low level), is
often used. The aircraft reaches about 4,000
feet in this manoeuvre which lasts less than
30 seconds .
• The high workload associated with IMC and
night operations reduces lookout by F-111
crews. Fortunately, other air craft do not operate in these conditions at low alt itude, so the
chance of a collision is virtually non-existent.
In VMC, turn points and attacks require some
increased cockpit activities, so lookout in t he
'danger sector' is reduced for 30 seconds or so
during t his phase of flight . This occurs about
t hree times during a two hour flight.
So far I have outlined some of the F-lll 's operating ch aracteristics. All crews are very aware
of the risk of mid-air collision (two aircrew
died in September 1977 after a collision with a
bird). Preflight preparation undertaken by the
crews, specifically to avoid mid-air collisions
includes:
• Study of charts which show sensitive areas
(noise, particular industrial activity, intense
crop-spraying areas, licensed airfields and
other active airfields that crews notice during
missions).
• Submission of rout es t he preceding day for
NOTAM action.
• Referen ce to the flight planning section to
note, amongst other things, any cr op-spraying
activity that has been advised.
• Preflight briefing of known conflicting traffic,
lookout responsibilities, listening watch and
HF frequencies .
In summary, an enormous amount of planning,
t raining and administration goes into low-jet
op erat ions to improve safety margins an d to
minimise the risk of collision. The F-111 operator s would like to think that other users of
low-alt itude airspace are equally concerned.
From our perspective, there are a few things
you can do to help. It is difficult to see an
F-111 cruising at your level or lower, particularly since it may approach from any direction,
so it is best to:
• Tell us w here you will be and when, and we
will try t o avoid your ar ea of operations (submit a flight plan, advise flight Service Operators or phone Amberely Operat ions on
07-280222 as many Ag pilots do now). We can
contact our F-11 1 crews Australia-wide, at
any time to relay such information.
• Find out where we are from our NOTAMs or
appropriate VHF FS frequencies and avoid the
area or t ime - or at least be alert for our
presence. Remember we are busiest and most
unpredictable at turn-points. These ar e shown
on NOT AMs. On low-level legs, we are rarely
above 1,000 feet, except at some targets
where we also turn - hence it is safest for
you above 1,000 agl or below 200' agl.
One point that s hould be made, is that in lowlevel attack t raining, we do not use the radar to
detect and avoid aircraft. You may be aware of
ou r air-to-air radar modes, but in low altitude
attack missions, we use the radar only for navigation and terrain avoidance.
For u s too, the 'eyes' have it!
The bottom line for VFR operations, is that we
ALL must keep our heads OUTSIDE the 'office'
and when w e are advised of other t raffic in the
vicinity, u se t he information intelligently and
ult imately:
• LOOK AFTER each other and LOOK OUT for
each other D
Eyes in the back
of youli head
Brian Bigg is a j ournalist who has just gained his RPPL.
Here he expresses his views on flying at Bankstown.
ATURE DID n ot consider student pilots
when she gave us only one set of eyes.
-Having recently passed my restricted
licence test (relat ively unscathed), I recommend
that when a person walks off the street into
flight school at Bankstow n , he or she be presented (perhaps for a refundable deposit) with
at least another two pairs of eyes for use in the
circuit and t raining areas .
Even having extra rented eyeballs, however,
won't prevent that heart-stopping shock of
looking up from intently pract ising a tight turn
to see another student, equally intent on practising a tight turn, whizz by within spitt ing distance (alt hough, of course, by that sta ge one's
mouth has gone completely dry).
N
Circuit views
The student's first solo sorties in the circuit at
Bankstown, can t ake year s off his life .
The feeling of 'flying is a doddle', that one gets
after going solo for the first time, withers
quickly when the twin overtakes you late on
downwind while there are already eight planes
in the circuit and the air is murky brown.
'How dare you?' you shout, indignantly. The
diagrams in t h e textbook were quite clear on
cir cuit procedure. As you w ave your fist at him
the first trickle of uncertainty cr eeps in.
A glance at the right hand seat r eminds y ou
that the instructor, from wh om all wisdom emanates, is no longer ther e to clutch. A scream of
'handing over!!' had generally got you out of
trou ble before. But this is now ... what should be
done?
Forcing yourself to stay calm and being too
unsur e of yourself to ca ll the tower for help ,
you extend t he leg, t urn too soon onto final,
speed up t o stay in front of the Cessna behind,
and finally, too fast, too h igh and totally bewildered, decide to go around.
On on e occasion t his happened to me , I
announced my decision to go-around just as
another aircraft took-off from the strip at the
other end on a tou ch-and-go. I ended up sixty
metr es behind him - both of us only fifty feet
from t he ground.
To make matters worse, at the same time my
radio switch jammed on, so the tower couldn't
contact me to find out if I was in control.
�Aviation Safety Digest
136
Everyone in the circuit could have h ea rd me
promise God a life of purity and piet y if he
would save me just this once. It taught me to be
much more s trict with myself in circuit
procedures.
Worse was to await me in the training are a.
Flying in the Bankstown training area is riskier
than telling a heavyweight boxer you think his
mother is ugly.
On the weekends, swarms of aviation hopefuls
take to the air to practice forced landings, stalls
and tight turns. One of my instructors told me
he preferred not to go near the training area on
Saturdays or Sundays because it was too
dangerous.
At Hoxton Park, aircraft enter and leave the
circuit at the same rate as cars cross the Harbour Bridge. Everyone appears to have a different interpretation of the proper procedure and
in the murk that sometimes passes for air in
Sydney, one's head cannot swivel fast enough
on one's neck to cover all areas from which
other planes will attack.
On one occasion, while joining downwind at
1250 feet agl, another aircraft overflew the airstrip across my path, no more than a stone's
throw above me and believe me, if I'd had any
stones with me he'd have copped one.
The air above t hat pipeline is like Pitt St reet on
the weekends. One j oker even practices forced
landings along it. Aircraft come at you from all
heights, while others going t he same way as
you , conveniently sit just in the blind s pot
underneath you or behind the wing.
If, as I did, you decided to abandon the pipeline
and hunt further south for vacant air in which
to practise, there's the chance of getting very
friendly with someone practising aerobatics.
During my licence check ride, I had begun to
stall the aircraft as per the CFI's instructions
when an aerobatic aircraft dropped past my
right wing having just been put in a stall from
above me and a short distance away .
On one memorable day, I was returning to the
airport and reported inbound at Prospect Reservoir at 1500 feet. Much to the surprise of the
tower, two ot her aircraft also reported being at
Prospect at the same height, immediately
afterwards.
It came as a shock to me as well, but not nearly
a s much a s finding one of the planes, a Cessna,
close by on the right of my Tomahawk and
slightly below me, so we couldn't see each other
through our respective wings .
The other was above me and behind and I have
since developed the belief I'm safer not flying
on round number s .
The other trap for young players in the busy
skies of the training area is the lure of following a r ecognisible landmark, such as the pipeline which borders the Bankstown zone. The joy
of discovering the easy way back to the airport
is tempered by the realisation that everyone
else has too.
I've since moved to a less busy region but the
habit I developed of treating the airspace as
somewhere where ever y one is out to get me,
still has me scanning righ t to left and back
again t he inst ant my aircraft 's wheels lea ve t he
ground and I always check u n derneath the aircraft as I return from the t raining ar ea D
Training area blues
A measure of
success
by John Edwards
VIATION SAJ<'ETY DIGEST 134 provided a
series of articles on landing. Unfortunately,
_
the presentation concentrated heavily on
how to manipulate the aircraft and how to
a ssess when manipulation is requir ed . But
that's only half the story. To balance t h e discussion, an article on the oper ational decisions
and judgeme nts is necessary.
Therefore, this a rticle a ddresses the following
questions:
• What landing performance does this aircraft
have?
• How should I assess the approach and land ing
so t hat I achieve the predicted performance?
• What justification is t here to deviate from the
flight-paths and the techniques that form the
basis for t he predicted landing per formance?
A
-111
What landing performance do I have?
The basic answer to the performance question
is found in the ANO 20.7 series. For most aircraft, the landing distance required is based on
the landing distance that is needed, following
an approach at a speed not less that 1.3 times
the minimum speed (the minimum speed is the
stall speed or minimum steady flight speed, in
the configuration being used) , and it assumes
this speed is maintained to a height of 50 feet
above the landing sur face. The r esulting distance is then multiplied by a safety factor .
However, this is not the complete answer.
There are other consider ations such as:
• What is the angle of t he glidepath used during
the determination of landing distance
r equired?
• Are the pilots and techniques used dur ing
testing, repr esentative of ourselves (an average, typical pilot if there is s uch a person)
and the way we operate?
• How do the figures account for differing operating conditions such as wet runways,
tailwinds and older aircraft with a little more
wear on systems and tyr es than t he test aircraft?
• Are these consider ations accounted for in the
str ength of the air frame and undercarriage?
The next keys to a complete answer 11e in the
ANO 101 series. Broadly, landing performance
is established with t he expectation of a threedegr ee glidepath in normal operations. The
demonstr ated landing distance is factored - to
account for variables su ch as p ilot reaction
time, flying techniques and the condition of the
aircraft's systems.
�Aviation Safety Digest
136
Aviation Safety Digest
136
Other factors are applied for runway surface
and meteorological variations and all struct ures
are required to be strong enough to withstand a
normal operational life under the conditions
used to measure performance.
This is all very reassuring as long as the factors
are large enough and the braking systems work
correctly.
Firstly, the factors have been determined from
experience and found adequate for the vast
majority of operations and aircraft types. However, this does not mean that under extreme
conditions, they offer a gold-plated guarantee.
It means that they offer an adequate margin for
safety without incurring unreasonable operational penalties.
Retardation systems are a little more complex.
Duplicated or redundant systems are rare in a
light aircraft as t hey would impose unreasonable weight and cost penalties - so these aircraft may have a single system. On heavier
aircraft however, it is not unreasonable to have
two or more systems and for these aircraft,
landing performance is usually assessed on the
basis that at least one of these systems is not
used, but is in reserve - a built-in safety factor.
So there we have it. Landing performance data
is not absolutely perfect, but it does account for
most elements of most operations in a reasonable way - and if we fly our approach and
landing to parameters close to those used to
establish the performance data, we s hould stop
safely in the prescribed distance.
Assessing the approach
Achieving the expected landing performance is
heavily dependent on the approach being stabilised on the correct glideslope being maintained
and on crossing the threshold at the prescribed
height. These requirements are easily met with
the assistance of an ILS or a VASIS, but what
about the other runway s?
We are not quite as helpless as it may appear.
A simple calculation s hows that a three degree
glidepath w hich crosses the thres hold of a level
runway at 50 feet, will inter sect the runway at
a distance of 290 metres from the threshold.
Fortunately, most runways have maj.or
markings at 300 metres and these provide an
aim-point. Even if the runway is unmarked,
pre-landing preparation and self-briefing can
provide a good estimate by noting the runway
length and determining the proportional distance of the 300 metre point from the
threshold.
Judging a three degree glideslope without
assistance, is a little more difficult. Howev er,
experience, a stable approach and reference to
the VSI can provide a good guide. For most
approach es, the pilot has a r ea sonable idea of
the wind velocity and this enables an est imate
of groundspeed.
1
The r elations h ip betw een glideslope a nd
groundspeed enables t h e pilot to calculate the
expected rate of descent. The following table
and formulae will help:
Groundspeed (knots)
90
120
150
180
3' path rate of descent (ft/ min)
480 640
800
960
Rat e of descent ( ft/min) = Glideslope ( degrees) x
Groundspeed (nm/m in ) x 100
Rate of descent (ft/m in) = Glides lope ( percent) x
Groundspeed (kt)
[A simple rule-of-th umb fo r a three-degree glidepath is to
multiply the ground-s peed by five to determine the desired
rate-o f-descent. ]
Once the expected rate of descent is determined , the pilot has enough information to recognize if the expected performance is not being
achieved - the most likely causes are an incorrect glidepath or an inaccurate wind
assessment.
It is worthwhile examining the effect on landing performance if every thing other than height
over the thres hold, is correct. An extra 20 feet
for a three-degree glidepath means t hat the aircraft will touchdown 116 metres furth er down
the runway than expected and so t h e landing
distance is increased by this amount. (However ,
the determination of landing data accommodates threshold crossing heights up t o 10 feet
high - so this factor is n ot of concern unless
the 10 feet is exceeded) .
More importantly, the element that will
invalidate landing performance more rapidly
than any others, is excessive speed. Ultimat ely,
landing distance is required to allow the
braking systems to dissipate kinetic energy and
as energy increases a s the square of speed,
s mall va lues of excess speed have a significant
effect on the landing distance required. The
speed that is necessary to ensure landing p erformance should be extracted from th e flight
manual.
What deviations are justified?
A short wait at the holding point prov ides an
opportunity to wat ch landing p erformance in
real terms. The variations in glidepath,
threshold height and touchdown points are surprising. A glance into the pre-threshold area
shows that not all touchdowns occur on the
runway - and t he range in tyre-mark sizes
proves that short landings are not the exclusive
product of one pilot or aircraft group.
Why is it then that p ilots choose to approach
and land in a way that fails to replicate t he
conditions necess ary t o ensure the v alidity of
the landing data that is provided in the Flight
Manual?
Firstly, let 's look to see if the conditions of the
performance data are realistic:
• What does the 50 f eet crossing h eight offer us
and what is the effe ct of the consistent
glidepath? The .threshold crossing height prov ides a buffer against touching-down short of
the runway. It allows for mishaps due to turbulence on late final (the change of texture
bet ween t he pre-threshold area and the runw a y frequently cont ributes to turbulence) and
it prot ects a gainst vertical position variations
p ossible w ith 'on slope ' indications from landing aids - e.g . w ith a three-degree glide slope
and nominal 50 ft threshold height, t he VASIS
will indicate 'on glide-pat h' for crossing
heights as low as 39 feet. The glidepath plays
a major role in controlling the length of the
zone on which touchdowns occur. As you can
see, there are sound reasons for these factor s
and buffers .
• Are the selected values reasonable? PNG
experienced people will recall that la nding
performance in that area, was predicated on a
threshold cr ossing-height of 30 feet for some
specially approved operators and pilots. We
should recall that many operations in P NG
would not h ave been possible if this type of
safety compromise had not been made. At the
same time, we need to recognise that oper at ions in Australia do not have to accept this
t ype of increas ed a nd avoidable risk - as
that lit tle ex tra run way length and 'normal
margins' can be p rovided comparatively
cheaply .
So, why do we see t ouchdowns on the pia no
keys? Common r easons ar e 'to tur n off at a convenient exit and so min imise taxi time', 'runway behind you is unusable' an d 'to
demons trate fly ing accu racy and a ircr aft
control'. To this list we should a dd 'to take a
risk'. Perhaps a pilot who de liber ately crosses
the thresh old below 50 feet would be justified
- if there was eviden ce to suggest that the
factoring used in determining landing performance data w a s suspect. However, the si gnificant
weight of operational history does not support
such a, position.
Secondly, this pilot is accepting higher-thannormal risks immediately prior to and during
the flare , to achieve a landing distance that is
less than t h e distance both he and his air cra ft
require for normal, safe oper ation - ~nd that
distance was used to determine the acceptability of the str ip in the first place!
Normal operations frequently include situations
such as gusting wind or tu r bulence when it may
be prudent to approach an d lan d at an h igher
speed to ensure adequate control. Ther efor e,
when speed increases are warranted, w e should
remember that it is the groundspeed on touchdown t hat will affect landing p erformance
rat her than IAS. Consequent ly, an increase in
fin al IAS by a value propor t iona l to the s teady
surface h ead-wind, p lus a percentage of the
gust factor, will not unduly jeop ar dise landing
performance. It's a m atter of relative risks or risk management .
Occasions may a rise when the total risk to t he
success of an oper ation can be minimised by
deliberately accepting a slightly increased risk
in one aspect of the exercise . However , where
landing and landing per formance is con cerned ,
the only measur ed data available is presented
in the Flight Manual, it is presented w it h the
benefit of accumulated experience, it accounts
for the factors involved in landing and combines them in a way t hat minimises the overall
r isk in that phase of flight.
Therefore, it must be wiser to condu ct an
approach and landing as closely as possible to
landing per formance criteria - and I can only
conclude tha t pilots who cross the threshold
low or high, from less -than-optimum approach
paths or at speeds that ar e higher than necessary, ar e merely experiencing on e of t hose slight
inaccuracies t o which we ar e all prone - or
perhaps they can contribute yet another article
to the Digest to ensure a complete and meaningful discussion.
Happy (and accur ate) landings 0
�FOR YOUNG
PLAYERS
Trap 1
After a two-and-a-quarter hour flight the glider
pilot entered the circuit and was distracted by
a tug aircraft that was on final as he was on base.
He then realised that he was undershooting and
to correct the problem, planned to land diagonally across the field to shorten his approach path.
This still resulted in an undershoot.
The aircraft touched down in a paddock short
of the field and struck an earth bank at a speed
of about 45 knots. The aircraft ground-looped
and was substantially damaged.
The weather was fine and the wind was a light
northerly.
The air-brakes had been deployed prior to the
glider turning final. It was possible that the
pilot was distracted by the presence of the
other aircraft to the extent that he forgot that
the airbrakes were still deployed.
had to cross a ridge line. As the aircraft
approached the ridge the pilot noticed that the
aircraft was descending. He applied full power
and jettisoned the load. However, the stub wing
of the aircraft struck some tall trees below the
top of the ridge and a short distance later, the
forward flight of the aircraft was arrested
when it collided with a lar ge tree. The aircraft
slid down t h e t r ee and became wedged between
it and two other trees.
The pilot was able to evacuate himself from the
wreckage and walk to the airstrip.
The pilot had previously taken 19 loads across
the ridge-line en-route to the treatment area. He
had been clearing the t r ee tops on the ridge by
30-60 feet on each run and planned to do the
same this time. However, the pilot reported that
as the aircraft approached the r idge-line , it
encountered a downdraught.
Trap 2
Trap 4
The flight was to evacuate an ill patient from a
property. The pilot had been advised by the
property owner to land on a strip about two
kilometres from the homestead, instead of the
usual one.
He was also advised not to use the southern
section of the north-south strip due to its rough
surface.
The remaining available strip length was 1400
metres, which was adequate for the operation.
The pilot set up a short-field approach to the
south, aiming to touch down on the threshold.
The wind was calm and the visibility was good .
The aircraft became slightly low during the latter stages of the approach and the pilot applied
power. He was not perturbed when h e realised
that the mainwheels would probably pass
through some long grass near the threshold.
Just before touchdown, the pilot felt and heard
a loud b ang.
Immediately, the aircraft adopted a left-w inglow attitude and despite oppos ite aileron, brake
and r everse on the right engine, the propeller
and the left wingtip contacted the ground. The
a ircraft s lewed through 90 degrees and left the
strip .
The ma in oleo and left wheel were found 116
metres along the strip and 25 metres left of the
centreline.
There was a concealed mound of earth in the
long grass short of the threshold.
Two Beavers were deployed for top-dressing
operations. After operating normally during the
morning, they stopped to refuel at about 1030
hr. The aircraft had been uplifting one-tonne
loads abou t every s ix minutes. Fuel endurance
w ith both tanks full was approximately two
hours.
The pilot was conducting his 25th takeoff for
the day, about one hour after refuelling. Witnesses obser ved that the aircraft did not
become airborne at the us ual point, two-thirds
of the way along the 675 metre strip. Liftoff
finally occurred at the end of the strip, but
almost immediately afterwards, the aircraft
clipped a fence. It was seen to sink slightly,
before climbing at a steeper than normal angle,
until some 250 metres beyond the fence.
At this point the nose dropped suddenly and
the aircraft dived steeply into rising ground .
Fire broke out and consumed much of the
wreckage. Preliminary investigation revealed
that the fuel selector was in the 'off' position.
The load was not dumped and t here was no
attempt to abort the takeoff.
This was the first occasion that the pilot had
flown this particular aircraft, and the fuel
selector in this aircraft was different to the
other Beaver that the pilot had flown.
In the previous aircraft, rotating the selector
anti-clockwise through 180 degrees changed the
selection from the rear to the forward tanks. In
the accident aircraft, a similar selection
changed the selection from the rear tank to the
off position. This difference had not been
brought to the pilot's attention and it was possible t hat he was not completely familiar w ith
the functions of the selector in this aircraft.
Trap 3
The p ilot was engaged in spreading fertilizer on
a forest. The airstrip being used was in a valley
and to fly to the area of operation, the aircraft
Aviation Safety Digest
136
It was considered likely that the takeoff was
commmenced with the selector positioned to the
almost empty , rear t ank. During the takeoff
roll, the fuel-low-quantity-bell and associated
light had activated and the pilot had ehanged
the selection by feel while continuing with the
takeoff. The selector was now in the off position and the engine stopped. The aircraft
stalled from too low an altitude to permit
recovery before impact. Perhaps the pilot had
'his head inside the cockpit' and w as changing
the fuel selection.
He was killed in the cr ash .
Trap 5
As part of a type endorsement, the instructor
planned a practice forced landing. The simulated engine failure occurred at a height of
2800 feet over an ALA. The pilot completed the
'trouble' checks and changed the fuel select ion
from left to right tank.
During the descent the instructor was distracted by a distress call on the area frequency
and consequently the engine was not exercised
(cleared) during the glide descent. (The call had
in fact come from his own aircraft as the
student had inadvertently pressed the transmit
button for his practice call as part of his
'trouble' checks.)
It then became apparent that the aircr aft was
undershooting and the instructor asked the
pilot to go around. When the the throttle was
opened at about 500 feet, there was n o
response.
The instructor took control at about 300 feet
and concentrated on maintaining airspeeed. He
left the gear down, flaps at 20 degrees and propeller in full fine. It was obvious the aircraft
would still touch down short of the strip and
the instructor flared the aircraft normally. The
aircraft touched down about 90 metres short of
the selected strip. The gear was torn off as the
aircraft went through several spoon drains and
the right wing was severed after collision with
an ironbark fence post.
No mechanical defect could be found with the
aircraft or associated systems. It was possible
that plug fouling resulted from the prolonged
period of idling and the lack of engine exer cise
during the descent.
After the abortive go-around, no attempt was
made to change th e aircraft's configuration to
increase the chance of reaching the field.
After the failed response the pilots did not use
the boost pump nor consider selecting coarse
pitch to extend the glide.
The manufacturer of the aircraft cautions
against prolonged idle power descents due to
the likelihood of plug fouling caused by the carbon deposit associat ed with a rich mixture at
low power.
The final cause could not be determined but
fuel mis-selection was also possible.
�Aviation Safety Digest
136
Aviation Safety Digest
136
aE a -=
s
Dear Sir,
I refer to the cover photo of ASD 134 and you r
caption suggesting that the F28 in the picture is
making a go-around.
The aircraft is not in fact making a go-around,
but is being purposely held down after takeoff
for the photographer.
For a two-engine go-around in the F28, the aircraft must be rotated to 15 degrees, max power
applied, and the flaps selected from 42 to 25
degrees. When a positive rate of climb is
achieved, the gear is selected up and normal
climb segments followed.
Clearly this is not the case here as the aircraft
is flying level with both engines at substantial
power and t he flaps in the latter stages of
retraction.
I myself have a blown-up, framed copy of this
fine s hot which was taken at Tennant Creek in
the NT.
One would hope that the photographer had
good ear protection!
Yours faithfully,
A. Kiiver
You are correct. John Raby also chastised me. I
used this rather dramatic photograph to
attract interest and to promote discussion.
Rather than use it to illustrate how to carry
out a go-around in an F28, I intended it to convey a 'too- late' go-around.
But I take your point. I would not want it
misconstrued.
One aspect that is well illustrated though is the
vortex pattern downwind of the aircraft - and
the reason for the holding-point being well
clear of the runway.
Dear Sir,
I should like to correct an error of fact which is
presen t in t he 134th edition of the Aviation
Safety Digest. Mr Rudolf's statement at page 22
that 'the RAAF did not take into consideration
the properties of the SPH-5' when acquiring a
new helmet is incorrect. On the contrary, the
SPH-4 Product Improvement Program, which
culminated in the SPH-5 , was closely monitored
from its inception both through direct contact
w ith Gentex Internationa l and the auspices of
Working Party 61 of the Air Standardisation
Co-ordinating Committee - an international
body of specialist, military, aviation medicine
advisers and researchers. An alternative helmet
to the SPH-5 was selected for Australian
Defence Force, n on-fast, jet aircrew simply
because it met the required project specifications and timescale more appropriately than
the Gentex product.
The Australian Defence Force continues to support the efforts of industry to further enhance
aircrew protection, and Mr Rudolf's comments
encouraging aircrew to persist in wearing their
life s upport equipment are endorsed.
I should appreciate your publishing the essential details of the first paragraph of this letter
in order that the record may be set straight.
G. R. Peel
Wing Commander
for Chief of Air Force Personnel
Thank you, Graham, for setting the record
straight. I think our industry, especially the Ag
operators, would be most interested in the
RAAF and ASCC Reports if they are releasable.
It's a fairly dark and moonless night as we
reboard our aircraft at Port Pirie for the return
flight to Parafield. A few clicks of the mike and
the place lights up, like a Christmas tree wonderful invent ion, PAL.
Taxi call to Adelaide FS made and acknowledged and we head down the runway and up
into the inky-black. A quick look back at the
lights as we set heading, I check a few figures
and give the depar ture call to Adelaide FS.
No answer.
Try again. Oh, oh! Out with the ERS and we
make a few quick calls to other FS frequencies.
Nothing.
Another problem. It's a dark night with no horizon. Every time I look at the radio or ERS I
start a turn [no auto-pilot] . Good thing there's
another pilot on board. I fly, he fiddles.
I look back at Pirie again. The lights are out by
now. No comms and therfor e no way to
reactivate them. What to do now?
Continue flight as per flight plan and hope for
something good to happen when we reach
bright lights. The transponder gets a thought.
We squawk 7600 and hope someone sees that.
Bright spark in the right-hand seat suggests the
ADF may be worth listening to. On it goes and
- BINGO!
"Alpha, bravo, charlie, this is Adelaide. You are
cleared for direct track PIR to PF according to
flight plan. Maintain 5000. We are receiving
your transmission. Acknowledge my transmissions and listen out on ADF".
Wonderful! Big brother is listening and
watching for us. The flight proceeds normally
with the message changing once to tell us to
overfly Edinburgh and when to descend for PF,
whose tower by now is not manned. Approaching ED we are surprised by a burst of noise
over the radio. Terrific.
'Adelaide, this is ABC, we are back on air'.
'ABC this is Adelaide, welcome back to the fold'.
And the rest of the flight proceeded with normal communications and a safe arrival at PF.
Moral to the tale: all is not lost if you have a
radio failure at night. Big brother can help if
you remember to listen out on the ADF. Having
another pilot on board removed much of the
stress that could have been experienced under
the conditions at the time and aided the safe
completion of the flight.
I hope this tale helps a fellow pilot.
Best wishes,
Adrienne Williams.
Thanks, Adrienne. You make several important
points and I particularly endorse your comments regarding the presence of another pilot
to reduce the workload. And perhaps 'big
brother' is not such a derogatory term after all.
Dear Sir,
I would like to draw attention to an area of risk
that could result in a mid-air collision.
The problem of unnotified traffic conducting
aerial work at navigation aids, OCTA, has once
again surfaced. Two aircraft operating over
Redland Bay NDB near Brisbane wer e recently
involved in a near miss in VMC. The aid is situated OCTA and the pilots concerned were not
aware of each other's presence. In this instance ,
the see-and-avoid concept worked. Both pilots
had advised Flight Service of their position
over the aid and their intentions to conduct
A WK, but were 30 minutes apart in arriving
over the aid. The first aircraft to arrive was a
NOSAR aircraft and as su ch, did not generate a
Flight Strip with t he Flight Service Unit .
Additionally, the Flight Service Officers had
changed shifts in the period between the arrival
of each aircraft over the aid so that the officer
on duty at the time the second aircraft reported
its arrival was not aware of the first aircraft
and correctly advised 'no known traffic' .
Notwithstanding the fact that the pilot of the
first aircraft should have heard the second a ircraft report over the aid and that both safety
pilots should have been keeping a good lookout,
an aid is a point of convergence r ather like a
road intersection - and that is where collisions
occur because that is where the traffic is.
The obvious fix is for pilots to be encouraged to
submit flight plans and to operate on full
reporting for instrument training flights,
thereby ensuring their presence is known to
Flight Service and can be passed on to other
traffic in the same area.
R. L. Williams
,
You have highlighted an area of real concern. I
know that near Canberra, the Yass and
Goulburn NDB's are in the same category - as
are the Stonefield and A rdrossan beacons in
South Australia.
L et's all treat instrument training as the real
thing and submit a flight plan.
Dear Sir,
You may find the following of interest to
readers of Avi ation Safety Digest.
Several days ago I was required to fly from
Sydney to Canberra on business. I was unable
to rent my usual aircraft and decided to try
something new; t he TB-20 Trinidad. After being
checked out, I filed my flight plan, met my
passenger and we boarded the aircraft .
Takeoff was normal and on leaving the
Bankstown zone, I altered heading, commenced
a cruise climb to 2000 feet OCTA and changed
freq uencies.
No other station appeared to be using the
Sydney frequency, although the squelch did not
appear to fully 'quiet' the receiver.
I then gave a departure call to Sydney FSU. No
acknowledgement, but the frequency was still
quiet.
I t ried again; still no answer. (All hands having
a cup of tea?)
I tried again ; still nothing.
At this stage I decided I may hav e a radio problem and t urned to advise my passenger that we
may have to return to Bankstown.
He was in deep conversation using a p ortable
cellular radio telephone.
I asked him to switch it off, which he did, and
the radios immediately leapt back into life.
I gave my departure call, which was acknowledged by Flight Service, who then proceeded to
berate me for not keeping a listening watch and
for transmitting over other stations.
I did not notice if the radio navigation aids
were effected but expect that they would have
been.
Portable and mobile Cellular Radio Telephones
transmit in the frequency range 825 MHz and
receive from 'cells' on frequencies from 870
MHz to 890 MHz. The unit which interferred
with my radio had a power output of less than
one watt.
Mike Norman
Thanks for the warning, Mike. I'll see if other
pilots have had similar problems.
�
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Aviation Safety Digest
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Aviation Safety Digest, number 136 (Autumn, 1988)
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136
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1988
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ASD 135
SUMMER 1987
�Av1at1on Safely Digest is prepared by the
Department of Transport and Communications
and is published by the Australian Government
Publishing Service. It 1s distributed to Australian licence holders (except student pilots),
registered aircraft owners and certain other
persons and organisations having an
operational interest in safety within the Australian civil aviation environment.
Contents
A year lo remember
4
ALA's alas
How to sneak up on an ALA.
-
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Department of Transport and Communications
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
7
Aviation Safely Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
s/Jmulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Department. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
If it wasn't difficult enough already
The hand-held microphone can be the last straw particularly on landing.
8
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A. C. T. 2601.
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Photographic competition
The 'unsafely' category.
10
The heat is on ...
Temperature affects not only the aircraft performance.
12
Strike me lucky and strike me pink
Wirestrikes -
13
16
continued.
Reader contributions and correspondence
should be addressed to:
The Editor.
Aviation Safety Digest
Department of Transport and Communications
G.P.O. Box 597,
Canberra, A. C.T. 2601, AUSTRALIA
© Commonwealth of Australia 1986
ISSN 0045-1207
R85/979(8) Cat. No. 87 1577 8
Any landing that you walk away from
The humble windsock In an age of databases, inputs and outputs, the simple
tubular rag is still invaluable.
23
Traps for young players
Pitfalls that lie in wait for all of us.
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S. W. 2142,
AUSTRALIA
The safety promotion program includes seminars, pilot's nights,
the production of videos, posters and brochures and of course,
the Digest.
The Department has formed a Safety Promotion Section to
co-ordinate these activities. This team has direct contact with
the aviation community through various committees as well as
th rough the Regional Offices of the Department.
Please make use of this resource.
A cool-headed approach to survival.
20
'Safety Promotion ' is a term that you have probably been
hearing recently. Safety promotion encompasses those activities
which seek to improve our safety record and to encourage safer
practices by the dissemination of knowledge and experiences
on aircraft operations. It is a program which is designed to
supplement the rules and regulations and to encourage each of
us to both learn and to teach - by discussing our individual
experiences.
AIRFLOW
What goes up may have trouble
getting down
--
It would be interesting to see our Bicentenary year declared as
'The Year of Aviation Safety' - a year where we demonstrate
significantly that we can reduce the number of avoidable
accidents. If each of us was to double-check everything, if we
always left ourselves an escape route and if we made a
conscious, early decision to use that escape route, then
between us we could reduce the number of accidents
significantly - simply by each of us making sure that it is not
us that has the accident.
The readers' column.
An experience worth recounting and an encounter best
not experienced .
19
'he coming year is historic. Of major proportions will be the
celebrations associated with the Bicentenary. The year will
be significant in aviation terms too - air shows, air races,
fly-ins and hopefully, safety.
Within each Regional Office a Safety Promotion Liaison Officer
has been nominated. The SPLO is a valuable contact for clubs
and training organisations as a source of a diverse range of
safety promotional material from within Australia and overseas
- as well as a source of professional advice on safety matters.
Unless otherwise noted, articles m this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and comributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
Editorial ·
Thanks to all of you who have supported the 'new' Digest and
in particular-tor the positive feedback for the 'Human Factor'.
The Digest has also been recognised in an international forum.
The Flight Safety Foundation, based in the United States, has
announced that the Digest is the winner of its annual
publications award for 1987. I think that is a reflection of the
overall interest in safety shown jointly by the Australian aviation
community and the Department - and not just for the past
year bu t for the previous thirty years that the Digest has been
published. Australia continues to be a leader in this field . We
can all be proud.
Equally important was news from W.A. that the Digest is so well
regarded that it is hung on a string in the 'loo'. One of the most
effective ways of disseminating information is by presenting it to
a captive audience, especially one that is in a meditative or
contemplative mood. It is a practice that I support and I would
encourage schools and clubs to similarly hang a few copies for
·reflection'.
The Spring 1988 issue of the Digest will be a 'special' not only
to mark the Bicentenary but to coincide with the Bicentenary Air
Show and the 1988 Annual Convention of the Fligh t Safety
Foundation which is to be held in Sydney. Your contributions
will be welcome.
Let's make it a year to remember - in aviation safety terms 0
- ~--- · -.r
-- -··· --·---·-·
Font of wisdom?
Covers
Front . The cover photo is the winner of
Category One of the NIKON/ ASD photographic competition. It is titled 'Scottish
Pioneer' and shows a Scottish Aviation
Twin-Pioneer over Sydney.
Photograph by Ron Israel
Pentax 6 X 7 cm 120 Fujicolor Type S
Back. The winner of Category Three of the
competition was 'A little low wouldn 't you
say, Louie?' Fokker Friendship landing at
Parafield, S.A.
Photograph by P. T. Crowe
5 X 4 inch Royal Pan
Editor:
Editorial Assistant:
Graphic Design:
David Robson
Karen Hutchison
Lesley Gordon
1,/~
Photographs:? 4, 21
P7
PB
p 17
p 20, 23
David Robson
The Canberra Times
William Young
Allan Ash ·
BAS/
DAVID ROBSON
Editor
Diagrams:
Soussanith Nokham
�Aviation Safety Digest
135
margin. You need to also consider the prevailing
winds during your period of operation and, if
there has been any rain, how the surface will
be affected. If there has been rain it is a good
idea to remove the wheel spats from the aircraft. They can become clogged with mud.
If there is no windsock at the ALA have the
owner place a brightly coloured streamer on a
steel post in a pre-arranged position.
Step two -
Having completed this 'selection run' (at economical cruise power setting for your type),
climb to 400 feet agl and position the aircraft
on downwind. This selection run and the
remainder of the procedure is shown in the following diagram.
arrival
If, after the above deliberations , you decide to
ALA's alas
Steve Tizzard is the CF/ of the Canberra Aero Club and
has spent a lifetime flying little aircraft into and out of
short strips.
T
HE AIM of this article is to discuss oper-
1 ations into strips with which you are not
,._ familiar - safely and efficently .
As a gen eral rule - sneak up on them! By that
I mean that anticipation is half way to solv ing
a problem. Then approach the strip carefully
and look for possible traps that you didn't
anticipate.
We were taught a technique known as 'precautionary search' in our basic training. I
believe the name 'precautionary search' is
invalid. A more appropriate n ame for the
sequence is 'landing ground operations'. The
actual technique for an ALA operation does not
differ significantly from a precautionary search
and this recommended change of n ame might
a lso h elp remove the mystery from such
operations.
Step one -
plan ahead
Prior to contemplating t he use of an ALA, it is
wise to have a good look at Section 81 of the
VFG. In essence, you need to ensure that:
• The physical characteristics are suitable.
• The geographic locat ion is suitable .
• A method exists for determining the wind.
• You have consent to use the landing ground
(from the owner or occupier).
The above four elements determine whether a
landing ground is 'authorised'. [Even then,
check whether the aircraft's insurance is valid
for the particular strip.]
Always be cautious of information given to you
by people who have no aviation background.
Details of slope and length may be pure guesswork. It can be helpful if you can ascertain
what other types of aircraft have used the ALA
and when it was last used. Be very cautious if
the ALA has been u sed only by aerial
agriculture aircraft. Such operations are permitted from strips w hich are not suitable for other
general aviation operations.
Having gained all the information you can on
t he proposed ALA, consider if it is marginal for
your operation. If so, is there a more s uitable
A LA or airfield nearby . Also consider the use of
a different aircraft. For example two POB in a
Cessn a 150 might be marginal whereas two POB
in a Cessna 172 will give you a greater safety
use the ALA, make sure you arrive overhead
with plenty of time and fuel - so that you may
divert to a licensed aerodrome if you are
subsequently unhappy with any aspect of the
proposed operation.
On arrival bear in mind the mnemonic:
W - wind
0 - obstacles (on/ near strip)
S - size
S - surface
S - slope
S - shoots (undershoot/overshoot area)
S - sun (position)
(This mnemonic is equally applicable to selecting a field after an engine failure or for a precautionary search.)
In the case of the ALA operation , most of the
information is known before arriving but must
be reconsidered on the basis of your airborne
inspection.
Do not forget to cancel SAR on arrival. Regardless of whether or not you are a SARTIME or
NOSAR flight, it is sensible to arrange someone
to attend your landing in case you do have a
mishap.
Having positively identified the ALA do not, as
some manuals recommend, set the d irectional
gyro on North , during an inspection run. This is
a bad practice as you can lose your general
orientation during the inspection process.
Step three -
inspection
The next critical assessment is of the surface
wind. Use all the clues available - windsocks ,
smoke, trees, dams, dust and blown crops.
Before commencing any 'inspection run' I thoroughly recommend what I call a 'selection run'.
This is done, after car efully considering the
likely location of power lines in the ar ea, by
descending to abou t 200 feet agl well to the
right and parallel to the landing area. This
'oblique picture' enables you to more accu rately
determine any problems with:
• the approach area
• the overshoot area
• length
• slope
• shielding - which may induce wind-shear.
Only one selection run is shown on the above
diagram, however it must be repeated until you
are absolutely certain the landing area is suitable. Then comes the close inspection.
The inspection runs should be flown no lower
than 50 feet agl with repeated scanning of t he
following:
Obstacles (ahead) - and watch out!
Strip (condit ion)
A irspeed.
The aircraft should be in the approach configuration with part flap extended and with the
propeller in fine pitch, read y for full power if
required. Don't reduce speed below the normal
approach speed for your aircraft. During the
base leg and final segment of the selection runs,
you should be getting a ' feel ' for what the conditions are like (w ind , turbulence, sink, lift,
glare from the sun and the like). You must also
determine a minimum and maximum touchdown
point and stick to this touchdown zone with
religious ferver! If you are not on the ground by
the maximum touchdown point you must go
around. This point must be fixed in your mind
i.e. abeam an anthill, gate, tree or similar.
During the inspection run(s) you must a lso pay
attention to the texture of the surface i.e. is
ther e a green patch on a brown str ip? Be very
careful of any t rack which crosses the la nding
area . Is there an associated rut which may
cause damage?
�I
Aviation Safety Digest
135
.
Also be very cautious of any animals in the
same field. They may be stationary during the
inspection runs but mobile during the landing
ro ll. Stock on the downwind side will probably
run away from the aircraft - other stock may
cross the strip to join them.
The wire from very old fences can also be a
problem. Cattle can become entangled and don't
realise that they shouldn't free themselves and
leave the wire in the middle of an ALA! Watch
out for temporary fences across a s trip which
uses two paddocks. If there is a fence which
seems to disappear at the edge of Lhe strip look out.
Apart from animal diggings on the s urface (rabbits and pigs), it is also not uncommon to find
pieces of farm machinery or other miscellaneous objects on the ground.
Small rocks from 50 feet can be BIG when you
land on them.
Step four -
the approach
On your final approach please keep to the published airspeed and DO NOT ADD A FEW
KNOTS FOR MUM AND THE KIDS. In my
experience this is probably the major cause of
accidents in ALA operations. Wind-shear is the
only reason for carrying excess speed. Use the
recommended configuration for your aircraft
a nd for the conditions that exist at the time.
Also be prepared to go-around if you are
unhappy with any aspect of the approach.
[Your thought processes must be so organised to
land if all is okay but to to be prepared to
go-around at any stage.]
After touchdown use firm braking with the control column hard back. Use careful braking on
rocky, stony or patchy wet and dry surfaces or
with a tailw heel aircraft. With a taildragger,
keep the tail up as long as possible to keep the
end of the strip in sight.
If you have any doubt about the surface, shut
down as soon as you come to a stop and conduct a detailed inspection on foot. If you deem
this unnecessary, be careful of parking areas tie-down s takes are often left in the ground, are
difficult to see and can caus e a lot .of damage if
you taxi over one. ·Also be mindful of wire or
ropes in the parking area.
I should have liked to devote a major portion of
this article to landing on slopes. With proper
training (and curren cy) slopes of up to 15 per
cent with one way operations are quite acceptable but two per cent slope is all you are
allowed (excluding aerial agriculture operations) and is enough to contend w ith. Even a
two to three per cent slope can cause problems
for the uninitiated. There is a subconscious
illusion regarding the relationship between
slope and the approach angle which can catch
you out.
Aviation Safety Digest
135
Normal approach appears steep
Greater attitude
If it wasn't
difficult enough
already!
If yo u are landing up Lhe slope (and that is the
way you should be landing) look t o the far end
of the strip and make a definite flare. Only flies
can land on walls.
In hilly terrain watch out for false horizons.
The escape clause
Handheldmikesagain!
In addition to what I have already said, an
'escape route' must be selected during the
inspection run. A go-around, if necessary, may
well be conducted to the left or right of the
extended cent re line t o give:
• greater terrain clearance
• avoidance of inhospitable terrain
• noise sensitive areas, and
• known or expected turbulence.
Always select a go/no-go p oint for your final
decision and if you are not in the groove by this
point, go-around . In general, the t hreshold can
be a decision point unless the particular strip or
aircraft performance makes a go-around from
this point risky. In some cases the go-around
can be as late as from the last point of touchdown - the one you previously determined .
As
lar
be
be
0
Conclusion
In the closing stages of this article, I believe it
necessary to comment u pon a common problem
on final approach, where the approach profile
is all over t he place. Hav ing discussed ·this mat ter with pilots who have t he problem I believe
t here is a simple solution. Consider setting the
aircraft up very early on final in the approach
configuration, with the correct air speed and the
attitude that will hold that airspeed. Ii' you '
p erceive any change in the s ight picture (aimpoint or threshold 'sinking' or rising) make a
minor power change early and ensure you keep
the airspeed constant by making a
correspondingly slight change to the a ttitude.
Small, continuous corrections are the way.
Many people, who are nervous of ALA operations , get very low - apply 'heaps of power'
and f'ly almost level to the threshold and still
arrive high and fast.
ALA operations can be very rewarding and
enjoyable if done correctly - otherwise they
can be disastrou s.
Like many other aspects of aviation, successful
operations into unknown landing strips are
s imply a matter of how you APPROACH them 0
l.
.,.
.
you have probably gathered by now I have no particuliking for the use of hand-held microphones. They can
a downright hazard in instrument conditions. They can
an unnecessary distraction at any time.
E WAS UNDERTAKI NG his fourth solo
flight an d was to practise circuits with
touch-a nd-go landings.
He had flown about one hour dual and a half
an hour solo that day.
At about 200 feet agl on what appeared to be
an extended but normal approach , the student
was given a landing clearance. As he reached
forward to replace the microphone, he dropped it.
He leaned for ward t o ret rieve it and as he did,
the aircraft touched down heavily 200 metres
in from the thr esh old and bounced about eight
metres into t he air.
The pilot tried to recover the situation by pushing forward on the control column and applying
power. He then r ealised that contact was inevitable and he closed the throttle.
The aircraft continued in a steep nose-down
attitude and struck the runway with the propeller and nosegear which collapsed rearwards.
The aircraft started to wheelbar row along the
str ip slewing to the left before groundlooping to
the right and coming to rest on the flight strip .
The h and-held microphone is a potential hazar d. If you use one, th ink about what you will
do when someone calls you on shor t Final and what you 'll do if you d rop it .
Remember the priorities:
l. Aviate
2. Navigate (when everything is under control)
3. Communicate (when you have control and
are orientated).
In this predicament a late landing clearance is
not unusual. Often the t ower has no option. If it
happens though, you don' t have to answer
straight away. If you're cleared to land , then go
ahead and land - if not, then go around and
talk about it when you are safely climbing. Certainly ther e is some pressure to acknowledge
calls immediately but only if your priorities
allow it.
Having criticised hand-held mikes, I now would
like to balance the books and mention my second most active hobby-horse - intercoms or,
more precisely , out-of-come;!
I believe it is wrong, unfair , inefficient and negligent to try and teach fl ying in an aircraft
which either has no intercom or one which
doesn't pro vide clear and reliable communications .
As an instructor I have suffered d istorted comms,
faded comms, intermittent comms, comms which
wait for your second wor d before they decide
to turn t hemselves on each time, and comms
which require you use the t r ansmit button and
hence a second switch to select internal comms
or ext ernal comms and which invariably result
in you giving a lesson on 'straight-and-level' to
everyone within 100 nm radius!
Imagine how it is for the student.
Clear communications ar e close to the top of
the list of priorities for effective instruction if not the first priority.
'Was that "take off power" or "takeorr power",
over? ' 0
�, Aviation Safety Digest
Nikon
• 135
,.VIATION PHOTOGRAPHIC COMPETITION
.. ' ,,,,,'
~
.. "'\
'""'')
)
,_, ,, .. ,
AVIATION
GASOLINE
UN No. 1863
The Digest photographic competition was a
great success and I wou ld like to thank all who
participated. There were over fiv e hundred
entries and the standard was high ..Judging is
complete and the winners arc:
Category One
the open category for the
best overall photograph
was won by Ron Israel
with his print titled
'Scottish Pioneer'.
Category Two
the category for a photograph on a safety theme
was won by Bill Young
with 'What's in these
drums?'.
Category Three -
for the best black-andwhite photograph was won
by P. Crowe with 'A little
low wouldn't you say,
Louie?'.
The winners of the Digest/NIKON photographic
competition were announced in the last issu e
and the Category 1 and Category 3 winning
entries are presented on the front and back
covers of this issue, respectively .
The Category 2 winning entry is the double
photograph displayed opposite. The message is
clear - I think. This was an actual case of mislabelled and re-cycled drums . I am most grateful to Mobil for investigating the circumstances
of this s ituation and for their positive, safetyconscious attitude. I have therefore published
the letter from their Aviation Technical Officer.
The message to pilots is now certainly clear.
THE RESPONSIBILITY IS ULTIMATELY OURS
- AND I DO MEAN, 'ULTIMATELY'.
Photographs by Bill Young
Pentax ME Super. Kodacolor 135
Dear Sir,
Re confusing drum labelling
By now you should have received a letter from
our General Manager - Operations, explaining
the common industry practice of re-us ing aviation fuel drums for ground fuels, and the probable scenario of how the drums identified may
have appeared with double-brands.
Despite the best endeavours of our company, it
is possible that some transgressions on our
strict operations policy may occur with some
secondary drum users or country agents. While
the non-removal of a hazardous product identification label when re-using a drum may not
appear important to some, we view it with the
utmost seriousness. From a general safety viewpoint as well as from the potential misfuelling
aspect, we stress the importance of clear and
concise labelling.
The important lesson to all aviators from this
example is that all may not be as it seems.
Despite the carefu l labelling and the best care
and protection policies of the s upplier, there is
always the possibility, however remote, that
any item purchased for your aircraft may be
wrongly packaged or misbranded. ALWAYS
CAREFULLY CHECK THE CONTENTS BEFORE
USE. With petroleum fuels, only Avgas 100/ 130
is dyed green. Only Avgas lOOLL is blue. This is
done to a llow for your easy positive identification. (Occasionally the acceptable mixture of
Avgas 100/ 130 and the lOOLL may result in an
in-between colour, however this is still readily
identifiable against the r ed of s uper petrol and
pale yellow of unleaded petrol.) Always ch eck
the seals are intact and the drum is correctly
stored.
As an organisation Mobil makes every endeavour to ensure that confusing drum labelling
does not occur, and that only high quality clean
and dry fuel is provided. However, we have no
control over what happens to any drum once
sold . Operators should a lways check the contents of any container before use. If in doubt,
don't take the chance. It is important that you
become the hars hest judge. After a ll, it's your
life at stake.
Yours faithfully,
G. D. ZIPPEL
AVIATION TECHNICAL OFFICER
�Aviation Safety Digest
135
The heat is
on • • •
Or Harry Rance is a regular contributor to the Digest. Here
he talks about about the insidious but serious risks of
summer flying.
Many pilots concentrate their flying activities during the
summer months when they expect fine weather with clear
visibility in dry and cloudless conditions. It is these apparently perfect flying conditions which can cause havoc with
some.
R
ECENTLY I completed a trip to the Northern Territory with four friends. One of the
_
passengers had the 'flu prior to leaving
and despite the 'USual precautions at Milditra,
my throat felt 'all right '.
During the night I woke several times bathed in
perspiration. At breakjast I did not feel ill,
although I had trouble swallowing and I was
perspiring freely. I had the 11,sual amoimt of
fluid, orange juice and two cups of tea.
We departed for Alice Springs via a lunch and
refuelling stop at Leigh Creek. On arrival I still
felt well despite the sore throat and I lhoitght
the e.xcessive perspiring was due to the 30
degrees heat and the two cups of hot lea.
On departure, Leigh Creek radioed saying that
fue l appeared to be leaking from the left lank,
and as no other traffic was present, I could
land and check the cap on the runway. This I
did. I needed to sit on the shoulders of a male
passenger lo check the caps and despite the
humorous comments, it was quite hard work.
Nothing was found amiss and we departed for
Alice Springs.
We over~{lew Oodnadatta arriving on time and
our estimate for Finke was passed. A student
pilot was flying the aircraft from the right
hand seat and while I was explaining where we
were, DME distance etc, I realised my estimate
for Finke was wro~ig. I then started recalculating and decided my watch m'USt have stopped.
After querying the lime from the student and
realising the difference in GMT and Soitth Australian time I recalculated again. Finally it
occurred to me that I had added the miles lo
the estimated time interval instead of the minutes, so I crossed it out for the second or third
time, and added it again.
After a lot of eff ort I accomplished this task
and Finke was overflown as flight planned. By
this time rny head was aching and I f elt quite
hot and as it was getting la te in the afternoon,
the turbulence had also increased.
Aviation Safety Digest
135
I passed our ETA to Alice Springs after
labm.tring over the very simple addit'ion and we
arrived at that time.
After the usital landing and tie-down chores
were completed I felt very uncomfortable with
the headache becoming more severe. At this
stage I started to drink the soft drink we had
on the plane, and after the reaching the hotel, I
seemed to drink several gallons more.
Later that evening wh en I started lo flight plan
the next stage of the journey, I was absolutely
amazed at the state of that day's flight plan.
Besides the numerous crossing-outs of the ETAs,
the figures had become progressively harder lo
decipher. The errors I had made with the
addi tions were so obvious and it was hard to
believe the flight plan was mine. The ATIS
information for Alice Springs was written down
and I could hardly recognise my own writing
or figures.
There is absolutely no doubt in my mind that I
had a llowed myself to becom e dehydrated and
the difficitlty of the additions and the slate of
the flight plan was the direct result .of it. The
aircraft was on track at all times and navigation was not a problem, but i l raises the
question of how much more difficult i t would
luwe become if another problem had presented
itse ~f requiring clear thinking, or difficult
decision-making.
One could rightly ass·u me that this could only
happen lo a first-time Territory 'goer' with limited f lying experience and a 'dry' aircraft. Not
so, I have been on nitmero'US trips to the
outback, have over 2000 hoitrs experience, hold
a Commercial Licence with a Class I Instrument Rating, and on board the aircraft were
ten gallons of water and packets of soft drink.
It goes without saying that the fluid on the aircraft was taken in liberal doses by the pilot
and crew for the remainder of the joitrney.
This article is directed at three specific aspects
of s ummer flying w hich can be disastrous if
care is not taken. These as pecLs a re interwove n,
but for ease of discussion will be dealt with
separately.
Heat Stress
This topic was discussed comprehensively in a
previous Aviation Safety Digest (122/ 1984) ~ut
some salient points are worthy of re-emphasis.
If you can get hold of a back copy it would b.e
worthwhile to read it again. An aircraft left m
the s un will obv ious ly 'soak-up' h eat especially those with a lar ge expanse of
perspex. Gliders are prime examples of the
potential for the effect of heat-soaking. The
advantage of the good visibility fro~ the 'glas.s
bubble' brings the disadvantage of high cockpit
t emperat ures when left even for a s~ort time. in
the s un. Temperat ures within cockpits may n se
to 15-25°C above ambient temperatures and the
surface temperatures of items within t he cock-
pit may be even higher, in some instances even
high enough Lo cause Lrue burning or the skin.
A princip le of physics taught to mosL of us at
school or learnt by experience was thaL black or
dark objects are good absorbers of heat so we
should ensur e that our clothing is light
colou red , preferably whiLe, to reflect as much
heat as possible. Headgear is useful and w ill
he lp to keep the head cool especially if there is
a layer of air between t he hat and head.
While you expect the heat to dissipate once yo u
get airborne due to cooler ambient ai r and the
loss of heat due to convection, conduction to
Lhe cooler air and radiation from the heated aircraft structure, there is the risk of h eat a bsorption beneath the cockpit from solar radiation .
The 'greenhouse' effect of the perspex 'bubble'
is very real , particularly if t he fli gh t is not to
a ny greaL altitude and is extended more t han a
few hours .
The effect of getting into a hot cockpiL and
being exposed to solar radiation is akin to
gentle cooking. Our bodies produce energy
internally for u s to live, to drive our inLernal
engine and heat is produced . We take in fuel ,
food and drink, and convert it into energy for
life. The heat produced is us u ally lost to the
environment a s with any other mac hine, by
radiation, conduction and convection Lo the surrounding environment. In addition our bodies
produce liquid on the surface of the skin,
s weat, which is evaporated to provide
additional cooling.
If we are in a hot environment we are unlikely
to lose much, if any, heat by r adiat ion, conduction or convection to the surrounding air or
structures. Our only facility for cooling is this
evaporati ve effect of losin g fluid .
We have a ll experienced this phenomenon in
hot weather. With no breeze and little activity,
we are soon running with s weat because our
bodies ar e trying to remain within t he close
limits of internal temper atures for optimum
p erformance. Quite obviously to produce s weat
we need a reserve of fluid within our bodies
and this topic of fluid balance will be discu ssed
later.
What happens if we cannot keep our temperature down? Our design specification calls for
very narrow limits for the internal core temperature. To go outside those limits will produce a severe reduction of pe rformance. Studies
s how that aircrew make more cont rol errors in
hot environments than in temperate ones and
the errors are characterised by unpredictability.
Typically, errors were made in speed , altitude
and heading control movements. Attention was
narrowed and learning ability impaired among
student pilots. Newly acquired or little-used
skills wer e affected first as one would expect.
Heat s tress will add to other stressors su ch as
fatigue, sleep deprivation and emergency situations and may influence the most vulnera ble
phase of flight, landing - especially after a
long day of fly ing.
Dehydration
,
Mention has a lready been made that in a hot
environment, cooling of the body may only
occur through the evapor ation of sweat . The
formation of sweat is dependent upon fluid
being available within the body to be brought
to the skin surface to produce this cooling
effect. The body contains a large quantity of
waLer, about 60 per cent of body weight. We
maintain a balance of this fluid by drinking and
eating and then excreting excess fluid through
the kidneys.
We have all experienced the after-effects of
drinking large quantities of fluid over a short
t ime period . There is a need to rapidly lose the
excess fluid through t he kidneys. On the other
hand it we deprive ourselves of an adequate
water supply the body uses its own s tores to
produce s weat and if the store is not replaced
we lose more fluid that we can afford. This is
dehydration. The extent of the dehydration is
related to Lhe amount of sweat lost and the
amount of fluid we r eplace by drinking.
Once the ambient temperaLure rises to 33°C our
only chance of keeping the body temperatur e
down is by evaporating sweat. At that sort of
temperature the body needs aL least four litres
of water a day, even without a ny untoward
exercise. The fluid replacement mu st be spread
r easonably uniformly t hroughout the day. If we
exercise then we require more fluid. Climbing
around an aircraft on pre flights, manhandling
aircraft and s imilar tasks require more fluid. At
altitude the atmospheric pressure is reduced
and incr eases the evaporation of sweat which
compounds the problem.
As an aid to cooling, the drinking fluid s hould
be cool (iced water is not a lways easy to drink).
Tea and coffee are best avoided as they contain
caffeine, which is a diuretic. (A diuretic is a
substan ce w hich promotes excretion of urine
from the kidneys which is not what is r equired
in this situation. ) Alcohol, also a diuretic, is
obviously not a s uitable fluid replacement for
many reasons , especially when flying. When we
sweat we also lose salt, but there is no need to
concern ourselves on this count unless we arc
to be in the hot environment, working and
sweating, for more than a couple of days. If we
are in that position then salt should be added to
your meals as the most palatable means to that
end. It has been s uggest ed that y our fluid
intake should be spread throughout the day.
You cannot wait until you feel thirsty, it is too
late by then, you arc already dehydrated.
A better indication is the frequency of the need
to urinate and the colour of your urine; once it
is darker than a pale s traw colour you s hould
drink at least 250 ml of fluid ever y 30 minutes,
or more frequently if you are actively working.
�Aviation Safety Digest
135
Symptoms of dehydration include headache,
muscle weakness, drowsiness, nausea and
impaired vision. All these symptoms appear
vague and could be related to other conditions,
but in a hot environment dehydration must be
considered as the likely cause. The performance
of a complex psychomotor task as flying will be
affected in an insidious manner and you may
not be aware of your deficiencies until too late.
Sunburn
Most of us like to expose our bodies to the sun
to change our skin colour to light brown - to
tan our skin. Much advertising and peer pressure encourages the practice of 'sun bathing' to
achieve a suntan, but we are at risk of not just
tanning our skin but burning it. Sun burn is not
only an aesthetic disaster but may destroy skin
cells and produce scarring such as one might
see in a person burnt by fire or scalded by hot
fluid. Sunburn causes a change in the skin not
unlike a severe a llergic reaction, with swelling
and blistering. This process is accompanied by
pain, and if it occurs in the region of joints, a
substantial degree of immobility.
We are a ll aware of these dangers and if we set
out to 'sun-bathe' we usually take precautions
by not exposing our skin for too long or protecting the skin with suitable sunscreen applications. Problems arise when we bare our skin
for what we think will be short periods of time
and forget the effect when the sun is beating
down on bare skin through a side wi ndow or
even under a glass bubble of a cockpit. It is in
these situations when we arc trapped without
additional clothing or sunscreen agents that we
run into trouble and give ourselves yet another
stressor with which we have to cope on top of
possible dehydr ation, heat stress and all the
difficu lties of flying.
Conclusion
Flying in the summer months can be fraught
with danger unless we think ahead.
l. Attempt to provide shade for at least the cockpit of the aircraft.
2. On the ground have as much cockpit ventil ation
as possible, doors, windows a nd ' bubble'
open.
3. Ensure you have p repared yourself with
adequate rest and fluid intake in the days
beforehand.
4. Wear sensi ble clothing to reflect heat and protect against solar radiation .
5. Have a su n screen agent of your choice with a
high blocking factor; 15 + is safest.
6. Drink plenty of fluid during the day, aim for at
least 250 ml every 30 minutes or so and take
some on board your a ircraft.
Prepare your aircraft and yourself. Prevent
dehydration and sunburn and then enjoy your
flying and get home safe an d sound.
Stay 'with-it' 0
If you are not el ig ible for a free issue, or if you would like addit ional copies of the Digest:-
Strike me lucky
and strike me
pink
Strike one
FTER COMPLETING the first swath run,
the Agwagon climbed over a single set of
,
power lines. At the end of the second run
the aircraft flew under these same wires. As he
did so, the pilot saw for the first time a second
set of wires. He tried to go under them but the
canopy of the aircraft struck the cables.
The aircraft flew on but the pilot could see in
the rear-vision mirror that the fin and rudder
were extensively damaged. Rather than risk a
loss of control, he immediately landed in the
nearest field - a field of sugar cane.
The pilot escaped unhurt and I think he made
the right decision. However, the pilot had been
using a 'mud-map' provided by the property
owner. This map indicated the area to be
sprayed and showed, by means of crosses, a
power line at the end of the spray run. The
pilot assumed that this meant a single set of
wires, and being anxious to get the job done, he
didn't ca,rry out his own recce before starl'ing
the job.
Incidentally, the wire deflector cable had
broken and therefore allowed the wire to sever
the top of the fin and rudder.
$A 16 •00
(including surface postage)
to influence pilot behaviour by positive
reinforcement of sound techniques. It will
examine all aspects of piloting a nd publish
formal results as well as 'the tricks of the trade' .
The 'crash comic' will become a 'how not to
crash' comic.
or ove r thi rty years , the Aviation Safety
Digest has been an integral part of
Austra lian aviation .
In July 1986, responsibility for the Digest was
transferred from the Bureau of Air Safety
Investigation to the Flight Standards Division of
the Australian Department of Transport and
Communications. This move reflected the
perception that civil aviation may have reached
the limit of accident prevention through
regula tion and that the way forward is through
inc reased emphasis on safety education in
general, and the 'human factor' in particular.
Rather than just draw lessons from accident
investigations, the Digest will increasingly seek
Anyone with an inte rest in avia tion will bene fit
from tapping into this unique source of the
accumulated wisdom of the profession and
the latest resea rch into aviation safety in
Australia. Indeed, anyone with an interest in
high technology and the roles and limitations
of the huma n operator will fi nd this publ ication enlighteni ng .
Strike two
The pilot was reminded of power lines in the
area before he started spraying. There was also
a group of trees in the paddock. The pilot
sprayed the clear area first and flew over the
power lines at least twice.
He then told the owner he would spray the
area near the trees 'free hand' before finishing
the rest of the paddock. On the first pass near
the trees the aircraft struck the power lines. The
cockpit-to-fin cable deflector failed and one
power line struck the fin about 50 cm from the
top. The rear fuselage failed and the entire
cmpennage separated from the aircraft which
dived into the ground and came to rest inverted.
The pilot was seriously injured but did recall
having the power lines in sight as he planned to
go under them. The pilot's injuries were more
severe than they would have been because he
was not wearing a helmet and the seat belt
buckle failed . It was not of a type approved for
ag operations.
Please, please, please - wear a helmet, note
the wires and don't relax your lookout,
particularly after you have been spraying for a
while and you think you've got it made 0
Feeling a little query?
The AI RFLOW column is intended to p ro mote discussion on top ics relating to av iation safety. Input from studen t pi lots and
fly ing instructors is particu larly welcome.
Write to : AIRFLOW
Aviation Safety Digest
P.O. Box 594
CANBERRA A.C.T. 2601
Australia
Anonymity will be respected if requested .
'Immu ni ty' applies with respect to any
se lf-confessed infringements that are
hig hli ghted for the benefit o f othe rs.
•
Aviation Safety Digest 135 / i
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During November 1987, aircraft owners, operators and licensed aircraft maintenance engineers were notified via AAC 191 of Departmental approval for the
use of 'super' grade motor vehicle petrol in a wide range of single-engine
Cessna aircraft.
Please note that this approval was limited to high-wing Cessnas with low compression engines and that some types were excluded - such as the C210
series and other fuel-injected models.
Note also that approval did not include aircraft used for charter or ANR 203
operations.
The approval carried the proviso that the person who controlled the use of the
aircraft had applied for a flight manual amendment. This amendment includes
a number of limitations and cautions. The onus is on the applicant to ensure
that the aircraft is used strictly in accordance with the approved amendment.
Before using motor vehicle fuel, pilots must satisfy themselves that the flight
manual amendment applies to the specific aircraft they are about to fly. (Note
specific aircraft, not just aircraft type.) The fuel tanks should be placarded
and the pilot should be familiar with the cautions and limitations that are
applicable. If in doubt - don't use it.
NOTE:
• The oil companies cannot guarantee that the motor fuel is free from dirt or water.
• The engine may be more likely to experience carburettor icing.
• Mixing A VGAS and MOGAS will invalidate any dye test.
• Flight endurance may be reduced due to greater evaporation of MOGAS.
Any motor fuel which is used must be filtered in an approved manner to
remove possible contaminants .
Other aircraft types are being considered for approval and some have already
been approved to use MOGAS. Interested parties should contact the Regional
Office of the Department or refer to AAC 152 for further details .
�Aircraft accident reports
Safety contacts
..
The following information has been extracted from accident data files maintained by the Bureau
of Air Safety Investigation. The intent of publishing these reports is to make available
information on Australian aircraft accidents from which the reader can gain an awareness of the
circumstances and conditions which led to the occurrence.
Safety promotion liaison officers
Central Office
Telephone
062 686294
QLD
Steve Small
Flight Standards Division
Department of Transport and Communications
GPO Box 594
CANBERRA CITY ACT 2601
FACSIMILE: 062 497349
Bill Taylor
07 253 1211
Flight Standards
Department of Transport and Communications
P.O. Box 600
FORTITUDE VALLEY QLD 4006
NSW
John McQueen
02 2187111
Flight Standards
Department of Transport and Communications
P .O. Box 409
HA YMARKET NSW 2000
SA/NT
Mike Greentree
08 2180211
Flight Standards
Department of Transport and Communications
G.P.O. Box 2270 .
ADELAIDE SA 5001
VIC/TAS
Mark Perrett
03 6622455
Flight Standards
Department of Transport and Communications
G.P.O. Box l 733P
MELBOURNE VIC 3001
WA
Sam Todhunter
09 3236611
Flight Standards
Department of Transport and Communications
G.P.O. Box X2212
PERTH WA 6001
Bureau of Air Safety Investigation
Central Office
P.O. Box 967
CIVIC SQUARE ACT 2608
FACSIMILE: 062 4 7311 7
Sydney Field Office
P.O. Box K237
HAYMARKET NSW 2000
Melbourne Field Office
Private Box 1
Exhibition Street Post Office
MELBOURNE VIC 3000
iv / Aviation Safety Digest 135
Third quarter 1987
Brisbane Field Office
P.O. Box 24
BRISBANE QLD 4000
Adelaide Field Office
G.P.O. Box 1112
ADELAIDE SA 5001
Perth /Field Office
P.O. Box 63
GUILDFORD WA 6055
At the time of publication, many of the accidents are still under investigation and the
information contained in those reports must be considered as preliminary in nature and possibly
subject to amendment when the investigation is finalised.
Readers should note that the information is provided to promote aviation safety it intended to imply blame or liability.
Preliminary reports
The following accidents are still under
investigation
Fixed Wing
07 Aug, PIPER 34 200, VH-SMM, Non-commercial pleasure, CALOUNDRA QLD.
Shortly after touchdown , the gear unsafe warning horn
sounded and the red gear unsafe warning light began lo
fl ash . The right wing slowly lowered and the a ircraft
veered to the right of t he strip before coming to rest.
An inspection of t he right rnaingear revealed that the
rnaingear had collapsed because of the failure the maingear
s ide brace stud.
08 Aug, PIPER 28 161, VH-PZK, Non-commercial pleasure, KOORALBYN QLD
The pilot stated that the a ircraft touched down well into
t he 1400 metre strip, and a fter commencing to brake he
decided to carry out a go-around. During the attempted
go-around the aircraft crossed a deep gully, off the end of
the s trip, and the rear fuselage struck a dirt bank. The
impact caused the nosewheel to strike the grou nd heavily
and the nose gear s trutcollapsed. The aircraft skidded
across a paddock striking severa l fence posts and a fence
before corning to rest on a road, 208 metres beyond the end
of the strip.
10 Aug, PIPER PA31, VH-HVA, Charter - passenger
operations, MT ISA QLD
When t he a ircraft was about 75 kilometres south-west of
Mt Isa the left engine failed without warning. The flight
continued to its destination and the pilot decided to leave
the selection of fl ap and landing gear unt il late on
approach. When the landing gear was selected down there
was no response. The pilot carried out a missed approach
fo llowed by a low level left circuit during which he
unsuccessfully attempted to unstow the hydraulic hand
pump to manually lower t he landing gear. The aircraft was
s ubsequently landed 'gear-up' a djacent to the sealed runway on the grassed flight strip.
An inspection of the left engine revealed that bolts holding
lhe number 3 cylinder to the crankcase had fa iled. Also
that the operation of the h ydraulic pump handle had been
hampered by a build up of hardened lubricant and dust.
13 Aug, CESSNA 402 B, VH-TWZ, Charter - passenger
operations, CUNAMULLA QLD
Just after liftoff, at about 50 feet above the runway, the
pilot heard a loud bang and noticed smoke coming from the
left engine . Power was increased on the right engine and
the landing gear and flap retracted. However, the aircraft
began to descend and veer to the left before touching down
in no way is
on its undersurface. ll skidded for 103 metres and came to
rest 155 metres to the le ft of the runway centreline abeam
the upwind threshold.
An inspection of the left eng ine revealed that the thread of
the nut on t he number 2 cylinder connecting rod big end
bolts was stripped, causing the big end to become detached
from the crankshaft and forcing the connecting rod through
the crankcase.
23 Aug, PIPER 28 140, VH-CWE, Non-commercial pleasure, NOOSA QLD
The pilot was taking part in a fl ying competition consisting
of several fly ing sequences which were to be flown from
the right hand seat. A safety pilot/ adjudicator occupied the
left hand seal. The sequences included a practice forced
landing that was commenced from the upwind end of the
strip at an altitude of 1500 feet. This sequence was to be
conducted without the use of the aircraft instruments and
a ll the instruments, with the exception of the tachometer
and the vacuum gauge, were covered with a piece of
cardboard.
The pilot stated that he set the aircraft up in a glide for
runway 29, approaching over a tidal lake, and on late final
realised that an undershoot was developing. The safety
pilot said that he noticed the rale of s ink increase rapidly
on late final and when the pilot at the controls did not
apply power, he called for a go-around and applie d power.
However, the rnainwheels contacted the water and the aircraft nosed over corning to rest inverted in the shallow
lake, 150 metres prior to the runway threshold.
27 Aug, PIPER 28-235, VH-CEE, Non-commercial pleasure, CLERMONT QLD
The pilot and his passengers were on the final stages of a
trip through central and northern Australia. After spending
the night at Clermont they were observed to enter the aircraft and following an engine runup the aircraft commenced
the takeoff run. T he aircraft was then observed to become
airborne and a short time later the sound of an impact was
heard. The wreckage was located in t imbered country, 475
metres beyond the threshold of the departure runway.
27 Aug, GRUMMAN Gl6 4, VH-PUV, Aerial agriculture,
DUNWICH QLD
Just after takeoff, at about 40 feet above ground level, the
engine began to mis fire and run roughly , then failed completely. The pilot dumped the load a nd commenced a steep
turn to the le ft in an attempt to land on a track behind the
aircraft. During the turn he realised that the aircraft would
not make the chosen area and the aircraft was stalled into
the tops of the trees. After the impact it descended steeply
to the ground, the pilol escaped with scratches and some
bruising.
Inspection of the wreckage found that the left magneto had
become detached from its mountings.
Aviation Safety Digest 135 / v
�31 Aug, CESSNA Al88B Al, VB-IEV, Aerial agriculture,
AYRQLD 35SW
The pilot reported that shortly after liftoff the engine
began to lose power. He commenced to dump the load but at
about the same time the right mainwheel and tailwheel
struck an earth bank just beyond the end of t he strip. The
aircraft became airborne, and 115 metres further on the left
wingtip contacted the ground. The right mainwheel then
contacted the ground and the a ircraft swung through 130
degrees to the left and travelled a further 44 metres before
coming to rest.
14 Sep, CESSNA U206-G, VB-WEN, Non commercial business, NOOSA QLD
Just prior to touchdown, the pilot observed kangaroos on
the edge of the strip. He applied power with the intention
of carrying out a missed approach but one of the animals
ran in front of the aircraft. The pilot heard a thump and
realising the aircraft had struck the a nima l he abandoned
the go-around and landed t he aircraft.
Post flight inspection revealed s ubstantial damage to the
empennage and rear fuselage.
14 Sep, BEECH A36, VB-TLB, Non commercial - business, WILLOW GLEN QLD
The pilot had landed at the strip on a number of prev ious
occasions, but this was the first time in this aircraft type.
The final approach was made longer than normal. At about
100 feet AGL, with the airspeed at about 65 knots, the aircraft began to sink. The pilot applied full power to commence a go-around and as the nose pitched up, the left wing
dropped. The pilot d id not prevent the nose of the aircraft
pitching up, thus aggravating the almost stalled condition
o f the aircraft. Power was then reduced and the aircraft
landed heavily in a wheat paddock alongside the s trip and
slid s ideways as it came to rest.
Although the pilot had conducted short field landings in the
aircraft type, on a long strip, he had not previously conducted a landing on a short strip which required the use of this
short field technique.
01 Sep, BEECH 35 C33, VB-DHB, See circumstances
below, EMERALD QLD
During a scheduled 100 hourly inspection, a maintenance
organisation discovered s ubstantial damage to the right
wing structure consistent w ith the application of overload
forces to the right wing.
23 Sep, AEROCDR 500 S, VB-MEO, Aerial mapping/
photography/survey, CHARTERS TOWERS Q
The pilot had been conducting a six and a ha lf hour low
level survey flight. He stated that on joining the circuit at
the completion of the flight he lowered the la nding gear and
obtained a gear down indication. The gear indication was
again checked on final approach but during the s ubsequent
landing roll, as the nosewheel was being lowered to the runway, the landing gear handle in the cockpit s prung to the
up position. The la nding gear retracted and the aircraft
s lide to a halt on its undersurface.
An inspection of the landing selector found t hat it
functioned normally and no reason for its reported
deselection has, as yet, been determined.
24 Sep, MOONEY M20 B, VB-DUV, Non commercial business, THEODORE QLD 19W
Prior to proceeding to the flig ht the pilot checked the strip
d etails with the owner. The details included advice that
there was a power line on the approach. On arrival at the
strip, the pilot located a power line and assumed this was
the one to which the owner had referred. During the
approach, the pilot saw a single power line and attempted,
uns uccessfully , to avoid the line. The aircraft yawed
violently to the left, however, the pilot was able to regain
control and land the aircraft off the approach . A section of
the fin and rudder had been torn from the aircraft.
27 Sep, PIPER 34 200, VH-RYL, Charter - passenger
operations, ROMA QLD
After arriv ing overhead his destination the pilot selected
t he landing gear to the down position, but received an indication that the nosegear had not locked down. The emerg-
vi /A viation Safety Digest 135
ency gear extension procedure was carried out. but failed to
achieve a nosegear down and locked indication. The pilot
diverted the aircraft to Roma and following touchdown, the
nose was lowered onto the runway and t he aircraft slid to a
stop.
An inspection of the of the nosegear found that a bolt had
been incorrectly installed and had fouled the nosegear linkage rods.
13 Sep, AMER AIR AA-5A, VB-JSK, Non-commercial pleasure, ELDERSLIE NSW
The pilot intended carrying out a one-day return flight to
Luskintyre. However, when in the Luskintyre area he
misidentified the Elderslie strip for that of his planned destination and entered the circuit for a landing. It was
reported that the later part of the approach was flat and
the pilot stated that when the aircraft was about 10 feet
above the strip it suddenly dropped. Full power and back
stick were applied but the aircraft landed heav ily and
bounced. The pilot decided to go-around and during the
attempt the aircraft struck a runway light and a fence
before the throttle was closed.
29 Sep, HUGHES 269 C, VH-THR, Aerial Mustering,
TOOGOOLAWAH QLD
The pilot stated that after landing the helicopter he allowed
the engine temperature to stabilise for about one minute at
2800 RPM. He then reduced the power to about 2000 RPM
and after another minute, as he was about to disengage the
rotor, the helicopter was affected by ground resonance. The
pilot, who had already released his seat belt, was thrown to
the floor of the a ircraft.
13 Sep, PIPER 28 161, VB-MHE, Non-commercial pleasure, SCHOFIELDS NSW
The pilot had been authorised to carry out circuit and landing practice. The aircraft had been operating for about 20
minutes when witnesses reported that following a touch
and go it assumed a higher than normal nose attitude. At an
altitude between 100 and 150 feet above the runway, the
engine noise ceased and the aircraft pitched forward to a
steep nose down attitude. This attitude was maintained
until the a ircraft impacted the ground, 50 metres to the
right of the runway centreline.
02 Jul, AUSTER Jl B, VB-ASK, Non-commercial pleasure, W ALCHA NSW 30NE
The pilot was undertaking his t hird flight for t he day , during which he completed a number of circuits and landings.
Following a touch and go landing, the aircraft had reached
a height of about 300 feet when it was seen to commence a
turn back towards the strip. During the turn t he nose
dropped and the aircraft subsequently struck the ground in
a steep nose-down attitude. Initial investigation revealed
that there was virtually no fuel remaining in. the tanks, and
the engine was not under power at the time of the accident.
17 Sep, AffiPARTS FU24-954, VB-MYW, Aerial
agriculture, BRAIDWOOD NSW
The pilot was operating from an agricultural landing area.
During the takeoff run the left mainwheel struck a vehicle
tyre, that was being used as a strip marker. The tyre was
flung into the air and struck the left stabilator causing it to
jam in about the neutral position.
The pilot subsequently landed the aircraft in a paddock and
during the landing roll the aircraft struck a fence.
13 Jul, CESSNA 152, VH-FST, Instructional - solo
(supervised), BANKSTOWN NSW
At the completion of a flight in the local t raining area, the
student returned for a full-stop landing. As the aircraft was
flared prior to touchdown, the pi lot was a ffected by sun
glare. The a ircraft bounced a number of times and the
nosegear strut collapsed.
19 Jul, CESSNA Rl 72 K, VH-SPJ, Sport parachuting,
COLLECTOR NSW
The pilot was flying the jump aircraft for a parachute club.
After hav ing completed the fifth drop for the day, the aircraft was observed to make a high speed pass, at an altitude of about ten fee t above the ground, over a group of
spectator parachutists. The aircraft then climbed steeply to
an estimated altitude of between 200 and 300 feet before
carrying out a wingover type manoeuvre. It t hen descended
rapidly and impacted the ground in a slightly nose low, left
wing low attitude, before nosing over and comin g to rest 57
metres from the point oJ impact. The pilot was trapped
inside the wreckage, which was destroyed by the ensuing
fire.
06 Aug, CESSNA 180 G, VH-MJC, Non-commercial pleasure, EAGLE CREEK NSW
The aircraft had been parked overnight in freezing conditions, and a coating of rime ice covered the upper s urfaces. The pilot poured several buckets of warm water over
the aircraft before taxiing to the strip , about one kilometre
from where the aircraft had been parked. Takeoff was commenced after the various checks had been completed. The
takeoff was normal, but shortly after the a ircraft became
airborne the pilot noted that the performance was s luggish.
The aircraft tended not to respond to aileron inputs, and
the pilot was forced to use coarse rudder movements to
maintain directional control. The aircraft lost height and
struck large granite boulders before coming to rest adjacent
to the end of the 550 metre strip. Fire broke out and
destroyed much of the fuselage a nd t he inboard sections of
the wings.
11 Sep, PIPER 28 235, VH-FAR, Non-commercial pleasure, KULPRA STN NSW
The pilot stated that at an alt it ude of about ten feet a fter
lift-off, the engine fai led. The a ircraft landed heavi ly on the
nosewheel a nd the nosegear subsequently collapsed. The
pilot reported that on inspection the fuel tank selector was
posit ioned to draw fuel from the empty left wingtip tank
instead of the left main tank.
0
the aircraft bounced necessitating heavy braking for the
remainder of t he landing roll. The tail lifted and the aircraft nosed over and came to rest inverted on the side of
the road. Initial investigation established that the head had
separated from No.9 cylinder.
22 Aug, PIPER 38 112, VH-PCF, Instructional ...,- dual,
WERRIBEE VIC SSW
At about 2500ft above ground level during climb, a loud
noise was heard coincident with an rpm drop and severe
vibration. The prevailing wind was a 35 knot northerly and
after changing his selected landing spot a couple of times,
the instructor decided to land to the west as this gives
maximum ground roll. The aircraft touched down 188
metres from a fence and a 2 metre high levee bank. It impacted the levee bank at an estimated 40 knots, was catapulted
over the drain and landed inverted 15 metres beyond. The
student was able to extricate himself from the w reckage
but the instructor was trapped for 90 minutes until help
arrived.
It was determined that the loss of power was due to a
spark plug, complete with heli-coil, becoming dislodged
from the Number 1 cylinder.
22 Aug, PIPER 25 235, VB-KRT, Aerial application,
NHILL VIC ZONE
The pilot had just commenced spraying a crop of peas on
his own property. At the e nd of a swath run the left wing
struck a nine metre high tree during an attempted pull up.
The aircraft veered left, apparently out of control, and
crashed through a large gum tree 235 metres further on.
The aircraft came to rest inverted and caught fire. Initial
investigation indicates that the engine was performing normally prior to the impact. It has also been determined that
the pilot was not qualified to perform aerial agricultural
operations nor had he received any training for such tasks.
18 Sep, PIPER 25 235, VH-SGD, Aerial agriculture,
ALBURY NSW 60NW
The pilot was engaged in spraying a wheat crop. Two large
trees, 18 metres apart, were situated in the centre of the
paddock and the pilot intended to fly between the trees during one of the spray runs. He positioned the aircraft to fly
under overhanging foliage and as close as possible to the
tree on his right. As the aircraft passed the tree the right
wing struck a dead branch. The pilot was able to maintain
control of the aircraft and land it back at the airstrip,
approx imately three kilometres away.
12 Sep, BEECH V35 B-MK2, VB-ILY, Non-commercial pleasure, MITTA MITTA 3.5NW
Upon arrival at Mitta Mitta the pilot performed a touch and
go on the 1000 metre long gravel strip, before approaching
for the full-stop landing. After touchdown, the aircraft
veered to the right but was repositioned on the centreline
within a short distance . However, it again veered to t he
right and departed the hard packed gravel surface of the
strip and entered an area of long, damp grass. The pilot
was unable to control the direction of travel and the aircraft encountered a drainage ditch, an earth mound and a
fence before coming to rest with its noseleg collapsed.
21 Sep, MAULE M5-235C, VB-XCM, Non-commercial pleasure, HARTLEY NSW
As the pilot was unfamiliar with operations at Bankstown,
he had arranged to land at a strip near Hartley to pick up
another pilot who would accompany him to Bankstown. The
pilot inspected t he s trip from the air and was advised by
the pilot on the g round to land uphill, into the north-east. A
landing in this direction resulted in a quartering 10 knot
tailwind. The aircraft bounced on touchdown and began to
swing to the left. Being unable to regain di.rectional control,
the pilot applied full power to go around. During the
go-around the tailplane struck a fence, and the aircraft
came to rest against t he fence, 38 metres to the left of the
strip centreline and 250 metres from the initial point of
touchdown.
01 Jul, CESSNA 210 M, VB-MCE, Non-commercial pleasure, ARKAROOLA SA
On arrival at the destination strip, the pilot assessed the
wind to be from the west at about 15 knots. He decided to
land to the northeast using short field technique but during
the flare the pilot found he was unable to counteract right
drift and the aircraft touched-down on the nosewheel. The
nosegear subsequently collapsed, and the aircraft skidded
to a halt just off t he right side of the strip.
27 Sep, QUICKIE Q2, VH-BQQ, Non-commercial pleasure, PT MACQUARIE NSW
The pilot reported that as he flared the aircraft for landing
it dropped heavily, nose first, onto the runway and
bounced. He applied power and straightened the aircraft,
which then touched down on the mainwheels, but the nose
dropped again and t he aircraft overturned.
20 Aug, Affi TRACTOR AT 301, VB..JFA, Aerial
agriculture, CORRYONG VIC lOE
The pilot was spr ay ing a pine forest in hilly country. The
spray runs were made in the downhill direction only, which
requi red a low power setting during application. When the
pilot applied power at the end of a run, engine roughness
was noticed. He turned towards Corryong Aerod.rome but
the engine problem worsened to the point that he decided to
land. The only s uitable area was a road, but on touchdown
05 Jul, CESSNA 172-P, VH-WIQ, Non-commercial pleasure, ANTHONY LAGOON NT
The pilot attempted to takeoff on an access track to a cattle
yard. A southerly wind of about 15 knots necessitated
takeoff towards the yard. The aircraft was near gross
weight and short-field technique was used. At a position
411 metres from the brakes-release point, the right brake
caliper assembly struck a 1.65 metre high section of the
fence which formed the cattle yard. The right wing sheared
off outboard of the fuel tank when it hit an adjacent 3
metre high fence cap. The aircraft then impacted the
ground in a steep nose down attitude and slid inverted for a
short distance before coming to rest. The aircraft had been
airborne for 155 metres prior to the first impact.
11 Jul, PIPER 28 181, VH-TXN, Non-commercial pleasure, ALICE SPRINGS NT
After touchdown the aircraft bounced back into the air and
the pilot then raised the flap to the fully retracted position.
The a ircraft contacted t he runway nosewheel first, bounced
again and landed on its nosewheel for the second time. The
nosegear subsequently failed and the aircraft skidded
straight ahead and came to rest on the runway.
Aviation Safety Digest 135 / vii
�03 Aug, BEAGLE Al09, VH-UEM, Non-commercial pleasure, STREAKY BAY SA
After application of full throttle during the takeoff run, a
severe vibration developed which rapid ly stopped the
engine from rotating. When t he aircrart came to rest the
pilot noted that one of the two propeller blades had cleanly
separated from its hub.
08 Aug, CESSNA 402 B, VB-UBI, Scheduled passenger
service, ADELAIDE SA
Upon arrival at Penncshaw the pilot railed to obtain a gear
down and locked indication for the r ight main gear. Several
alternative methods were tried but a safe indication could
not be obtained. During a flypast, another pilot on the
ground observed the aircraft with the aid of binoculars and
reported that the gear appeared to be down. During the
landing roll the pilot felt the right gear start to collapse. He
decided to go-around and fly back to Adelaide where better
facilities were available. Several more attempts were made
to lock the gear in the down position, but to no avail. Our·
ing the subsequent landing the right gear collapsed at about
30 knots and the aircraft slid a further 212 metres before
coming to rest on a taxiway off the right side or the
runway.
06 Sep, AMER AIR AA5·B, VH-MQW, Non-commercial pleasure, INNAMINKA SA
The pilot decided to land on the shorter of two strips, using
a short field technique. Touchdown was made 94 metres
into the 470 metre strip, but the pilot was undecided
whether to apply maximum braking or to initiate a
go-around . Full power was applied and t he aircraft became
airborne for a short time before touching down in rough
terrain. It came to rest with both main gears collapsed , 282
metres beyond the end of the strip.
19 Sep, PIPER 32 260, VH-BMB, Non-commercial pleasure, COOBER PEEDY SA
Upon arrival in the circuit, the pilot assessed the conditions
and approached to land into wind on runway 04. When the
nosewheel was lowered onto the runway, t he aircraft
veered to the right a nd did not respond to the application
of left rudder. A go-around was initiated, but soon after
becoming airborne, the aircraft rolled to the right until it
reached a bank angle of about 50 degrees. The pilot
attempted to counter t he roll with the application of
opposite aileron but the a ircraft continued to roll right until
the starboard wing tip touched the ground. The auxiliary
wingtip tank ruptured and caught fire. The nose of the air·
craft dropped and t he aircraft struck the runway heavily in
a wings level attitude. The landing gear collapsed and the
aircraft slid to a halt outside the strip markers, with flames
now emanating from the engine bay and right wing. The
occupants then evacuated the aircraft success fully. The
pilot reported that a fter exiting the aircraft he sighted the
windsock which indicated a wind direction of
approximately 3 10 degrees and estimated the speed to have
been 35 knots.
28 Sep, CESSNA 152, VH-ALH, Non commercial - busi·
ness, MARYV ALE NT
The pilot was attempting to take-off from a dirt road to fl y
to the Station's strip to pick up his partner. Just as the air·
craft became airborne a slight left turn had to be negotiated. During the turn, t he left wingtip struck a clump or
bushes and slewed the aircraft to the left. The left wheel
struck an embankment and the aircraft proceeded through a
sma ll bus h and also clipped the top off another small tree
with the right wing. Full power was still applied to the
engine and the aircraft was again begi nning to fly when the
left tai lplane caught on a large bush which bought the air·
craft back onto the ground. The pilot then abandoned the
take-off attempt and closed the throttle. The aircraft ran
through another large bush before finall y coming to rest.
31 Aug, BEECH 58, VH-WLC, Non-commercial pleasure, PORT HEDLAND WA
After selecting gear down, a safe indication could not be
obtained for the left main gear. The pilot diverted to Port
Hedland where furthe r attempts to lower that gear also
fail ed . The gear was retracted and a gear up landing carried
out.
viii / Aviation Safety Digest 135
A similar le ft gear unsafe indication occurred 3 landings
prior, but on that occasion a fter recycling the gear a normal
extension was obtained.
23 Jui, CESSNA Al88B Al, VH-RYO, Ferry, BALLIDU WA
SSE
The pilot stated that at t he end of the take-off run the
wheels hit a 60cm high contour bank. He also reported that
he misjudged the dis tance between the point at which t he
takeoff was commenced and t he bank. The aircraft sus·
tained substantial deformation damage to the landing gear
attachment points and the carry through structure.
)
23 Sep, CESSNA 210 L, VH-MHC, Aerial application,
KUNUNURRA WA
The maingear uplock assembly had just been fitted with a
new seal and the aircraft was flown to ensure the correct
operation of the system. The gear retracted normally but
could not be lowered and a gear up landing was made.
inspection revealed that the unit had been incorrectly
reassembled after the seal was changed.
Rotary Wing
27 Sep, PIPER 28 140, VH-RVN, Non-commercial pleasure, CERVANTES llESE
After arrival at his friend's farm, the pilot s tated that he
was informed of acts of vandalism at Cervantes airstrip,
where he had left his aircraft. He inspected several possible
landing sites on the farm and next morning w~nt to the
strip to fly the aircraft back to t he farm. After doing a number of aerial inspections of the farm, an approach was made
to one of the chosen landing s ites. The site consists of a flat
touchdown area, then about 40 metres further on becomes a
steep and undulating s lope. The planned touchdown point
was overshot so a short burst of power was applied and the
a ircraft was flared in an attempt to land on the up s loping
s urface. The nosewheel contacted the ground heavily and
collapsed, then 25 metres from t he touchdown point, the
aircraft pitched inverted and slid to a halt.
02 Aug, BOEING 747-338, VH-EBT, Airline Transport,
GUAM 37S
QANTAS Flight 22 departed Narita with a complement of
327 passengers, and 22 technical and flight cre w.
The Captain reported that en route to Guam, isolated thun·
derstorm activity was observed on the Aaircraft weather
radar. A continuous radar watch was maintained, and t he
aircraft made a number of diversions from the planned
t rack in order to avoid the storm activity. About 30 kilo·
metres south of Guam, a heading alteration of 10 degrees
was made to regain track. Shortly after the turn was completed, the aircraft entered an area of severe turbulence.
The encounter lasted about 30 seconds, during which the
aircraft was subjected to accelerations of + 1.8 G to - 0.4
G (the acceleration due to gravity, normally + 1 G).
Both the Captain and the Second Officer (who was occupy·
ing the right hand control seat), had been monitoring t he
weather radar, and advised that there was a total absence
of returns from any convective cloud on either radar
screen. The aircraft was flying in cirrus type cloud, and no
lightning had been observed.
Forty eight passengers and one night attendant received
varying degrees of injury. As there was no warning of the
encounter, the seat belt signs were off. Most of the injured
passengers had been asleep, with their seat belts
unfastened. This was despite an announcement made in
English and Japanese arter departure from Narita, that
passengers should have their seat belts fastened at a ll times
when they were seated. The seat belt signs we re switched
on again at the onset of t he turbulence.
The cabin crew were assisted in treating t he injured by a
Japanese doctor. He adv ised the Captain that no one was
seriously injured or in need of specialist medical treatment
which warranted a diversion from t he fl ight plan. The
flight crew included two flight engineers who carried out
individual checks and inspections. They subsequently
ad vised the Captain that the aircraft was apparently struc·
turally and mechanically unaffected by the encounter with
the turbulence. In the light of the information provided to
him, the Captain e lected to proceed to Sydney as planned.
On arrival in Sydney the injuries were re-assessed, and
twenty eight passengers and the flight attendant were con·
veyed to various hospitals. All but one of the passengers
was released later that day. The passenger remaining in
hospita l was the only one considered to have sustained seri·
ous injury.
Maintenance engineers conducted a severe turbulence con·
ditional inspection , and found no evidence of any structural
damage to the aircraft. Both weather radar units were
removed, tested and found to be fully serviceable.
It was established that only one of the passengers who had
had their seat belts fastened at the time of the encounter
received any iaju1·y.
)
14 Jut, BELL 206 B, VH-PHA, Non-commercial pleasure, GA YNDAH QLD lOW
The helicopter was heading in a westerly direction following takeoff from the pilot's property. The track was to take
the aircraft directly over Mount Gayndah so the pilot
decided to t rack to the south of the mountain to provide bet·
ter terrain clearance. On passing abeam the mountain, at
about 500 feet above ground level, t he helicopter struck
two power lines, strung across t he flight path, between the
mountain top and a river flat below. The pilot stated that
he immed iately lowered t he collective and turned t he air·
craft towards a cleared a re a. Approaching the area it
became obvious to the pilot that the aircraft would not
clear trees on the approach path and he increased the collective. The helicopter cleared the trees and turn ed right
through 180 degrees before touching down in a level at ti·
tude whi le travelling rearward. The la nding skids collapsed
and the aircraft s lewed to the right before coming to rest.
An inspection of the helicopter revealed that impact with
the wires had occurred initially near t he ends of both main
rotor blades then on the upper surface of the tailboom. The
tai l rotor drive s haft was severed as was a substantial
portion of each tail rotor blade, and the tailboom was
almost severed at a position in front of the ve1·tical
s tabilisers.
22 Jul, HUGHES 269-C, VH-MZR, Aerial mustering,
ROSELLA PLNS QLD
The pilot was making a landing approach at the conclusion
of a s tock mus tering operation. The helicopter collided with
a single wire telephone line, t hen struck t he ground a nd
rolled onto its s ide.
20 Sep, BELL 206 B, VH-BLR, Aerial mapping/
photography/ survey, WAIKERIE SA 24W
The helicopter was flying at 40ft above ground level to
enable the cameraman to film a vehicle. The crew heard a
loud bang and the pi lot suspected an engine failu re so he
commenced an autorota tion. However, he quickly found
that the engine responded normally to power changes but
not knowing what caused the noise, he decided to land on
suitable terrain just ahead. After they had exited the heli·
copter, the cameraman reported to the pilot that he saw a
wire just prior to hearing the noise. Inspection of the
machine confirmed that it had suffered a wirestrike.
13 Jui, BE_LL 206, VH-BEQ, Charter - passenger oper·
ations, KARRATHA WA
After consultation with his passengers regarding the
expected d uration of the return survey flight, the pi lot
decided that he needed only one 200 litre drum to re-fuel.
Just short of Karratha he advised the passengers that he
would have to land due low fuel state. During the descent
the engine stopped, due to fuel starvation , and t he helicopter was substantially damaged
09 Sep, HUGHES 269-C, VH-PSK, Aerial mustering, ANNA
PLAINS 30SSW
Whilst mustering cattle near a holding yard, the helicopter
was being he ld in the hover in a 15-20 knot headwind.
Because some of the cattle broke away, the pilot turned
downwind to herd them back. As the aircraft rolled out of
the turn it began to descend and the pilot attempted to
arrest t he sink by increasing collective. However , the heli·
copter continued downward and impacted heavily on the
ground resulting in the tail boom being sheared off. It then
bounced into the air and began to yaw rapidly, but the pilot
quickly and firmly placed it back onto the ground. When
the helicopter came to rest the occupants were able to cxtri·
cate themselves from the wreckage.
The pilot reported that he believes he overpitched when he
increased collective during the recovery attempt.
Gliders
26 Sep, SCHLEICHER K7, VH-GQX, Instructional - dual,
JONDARYAN QLD
The instructor stated that after a normal rlight and circuit
approximately half air brake was set for the approach.
Additionally during the approach further ai r brake was set,
ror a short period, to steepen the approach. When the
instructor then checked t he indicated airspeed he observed
that it had reduced to less than 45 knots. He stated that he
did not close t he air brake in time to prevent a heavy
landing.
31 Aug, HUGHES 369-HS, VH-HED, Aerial agriculture,
RATHDOWNEY QLD
The pilot reported tha t s hortly after takeoff he sensed a
loss o r engine power and the helicopter began to descend
towards a fast flowing creek, over which it was passing.
The le ft s kid struck a log and the helicopter began to rotate
be fore settling onto s loping ground . The pilot switched off
the electrics and fue l before the aircraft rolled onto its side.
22 Aug, BURKHART ASTIR CS, VH-IKG, Non commercial
- pleasure, BORDERTOWN SA 4W
The glider was being winch-launched on strip 36. During
the launch, the le ft wingtip dropped into lush grass cover·
ing the strip. The glider rolled rapidly to the left around the
wingtip, until it was inverted. The aircraft impacted
heavily in this attitude and came to rest 96 metres from,
and 15 metres to the left of the take-off point.
A 10-15 knot north-easterly wind was blowing at the time.
17 Sep, BELL 47-G2, VH-KHK, Aerial Mustering, HAY
NSW 65W
The helicopter was engaged in the mustering or feral pigs
for a cu ll. After descending the helicopter to follow t he pigs
into a cleared area, the pilot noticed that more power was
required to fly the aircraft. The aircraft was immediately
landed at the base area, w here an inspection revealed damage to the leading edge of both rotor blades. The pilot
reported that neither he nor his passenger had been aware
of the helicopter striking any objects.
06 Sep, BURKHART TWIN ASTIR, VH-KYN, Instructional
- solo (supervised), BEVERLEY WA
The pilot was carrying out a practice circuit. Although t he
approach was good, the flare was in itiated too high. The
pilot attempted to correct by lowering the nose, however he
was late in initiating t he second flare. The aircraft struck
the ground and bounced into a nose high attitude. The pilot
again lowered the nose which resulted in another bounce.
The gear finally collapsed after the third ground impact.
20 Aug, BELL 47 G3B2A, VH·AAU, Aerial Mustering,
LEILA CREEK NT
At a height of 80 fee t above ground level with the helicopter almost s tationary, a total power loss was experienced.
Du ring the autorotational descent the main rotor struck
trees, and when the helicopter touched down t he right skid
was torn off and the machine rolled onto its right side. The
occupa nts evacuated unhurt through the pilot's door.
Lighter than Air
15 Sep, KAVANAGH D-105, VH-OBF, Charter - passen·
ger operations, W ALKAMIN QLD 5S
Following a check of the weather situa tion, t he balloon was
la unched in a five knot wind. After about 20 minutes the
pilot observed that the wind strength had increased and
decided to land the balloon. The passengers were rebriefed
Aviation Safety Digest 135 / ix
�on t he landing procedures and the burner pilot light was
turned off in preparation for landing. On touchdown, in an
estimated 20 knot wind, the basket tipped over a nd was
dragged along the ground for 90 metres before coming to
rest. Two of the occupants let go of the grab ropes on
touchdown and were thrown from the bas ket on initial
ground impact. During the ground slide two other passengers a lso let go of the grab ropes, the pilot managed to
restrain one and keep her within the basket, however, the
other passenger was thrown out of the bas ket.
05 Sep, THRUSTER GEMINI, NOT REG, Non commercial
- pleasure, BEULAH VIC 8W
The pilot reported that he had been flying over his farm for
a bout 30 minutes inspecting t he crops a nd sheep. When
crossing a road , whilst proceeding to another section of the
farm at a height of about 30 feet, he remembered the
location of a power line 50 metres ahead. He banked the
aircraft le ft to avoid the line, but the left w ing hit the top
of a tree. Control was lost and the aircraft impacted the
ground, coming to res t inverted.
20 Sep, KAVANAGH Kl60, VH-HGU, Charter - passenger operations, RUTIIERGLEN VIC 4E
In the final st ages of the landing attempt, the balloon was
affected by a rapid change in meteorological conditions.
This resulted in a collision with a small tree and the danger
of overshooting the planned, safe landing area just a head.
To ensure touchdown in the planned clearing, the pilot activated the rip panel at a height of about 45 feet. A heavy
landing resulted and the basket rolled over in the direction
of flight. Prior to touchdown, t he passengers had been
briefed and were standing braced ready for landing.
22 Sep, LIGETI STRATOS, NOT REG, Test, PENFIELD
VIC lE
The designer was test flying t he first production model
which incorporated several changes from t he prototype.
Witnesses report that the ultralight was being flown at
about 500 ft above ground level and that just prior to the
accident the pilot appeared to be testing the low speed
characteristics of the machine. The ultralight then appeared
to stall but reports vary considerably regarding the behaviour of the aircraft during its descent until its inverted
impact with the ground. The ultralight was not fitted with
a parachute.
Ultralights
22 Sep, RESURGAM ULTRALITE, NOT REG, Non commercial - pleasure, NORTH ARM QLD
After becoming airborne the aircraft proceeded to fly over
a nearby town be fore turning to head back towards t he
strip. Witnesses report that when the a ircraft was about
two kilometres south of the strip , the wings appeared to
'flap' and the aircraft descended rapidly hefore tumbling
into the ground.
An inspection o f' the wreckage found that the fabric on t he
wings had decayed and was generally of low strength . It
was apparent that the wings had lost their rigidity after
the fabric became detached.
30 Sep, SKYCRAFT SCOUT MK 3, NOT REG, Test,
BABINDA QLD ION
The a ircraft had previously had to be flown with the control stick displaced to t he right of centre in order to maintain a wings level attitude. The aircraft owner adv ised a
visiting ultra light pilot of the problem, who offe1·ed to
attempt rectification. After a conducting a flig ht to experience t he problem first hand , the pilot adjusted the right
wing warping wire and conducted another test flight. The
adjustment had improved the trim problem but still not
completely provided a fix . The pilot then readjusted the
right wing warping wire to its original condition a nd added
a D-shackle to the left wing warping wire to increase its
length. Another tes t flight was carried out and it was found
that the a ircraft could only be maintained in level flight
when full right rudder a nd full right control s tick were
applied. The aircraft was s truck by a wind gust and the left
wing dropped, as no further control was avai lable to conect
this situation, the pilot pulled a wing warping wire.
Unfortunately he pulled the right wire instead of the left
wire and was unable to correct his e rror before the aircraft
s truck the ground.
A subsequent ins pection of the wreckage found that the
right wing warping wire was 19 millimetres longer than the
left. Also, all the dimensions of the right wing were slightly
larger than that of the left wing, resulting in the right wing
a rea being about 80 square centrimetres greater.
26 Sep, HUGHES LIGHTWING, 250081, Non commercial
- pleasure, THE OAKS NSW
The student was landing the aircraft in a crosswind from
the right. As the speed reduced , during t he landing roll , the
aircraft began to veer to the right. The instructor applied
full left r udder and brake in an attempt to co rrect the situation but the aircraft continued to veer off the strip. Being
concerned that the a ircraft would strike a fence and overturn, the ins tructor applied full power in an attempt to
clear the fen ce and la nd in an adjoining paddock. The aircraft cleared the fence but subsequently stalled and was
blown back against the fence.
x /Aviation Safety Digest 135
FINAL REPORTS (The investigation of the
following accidents has been completed.)
Fixed Wing
01 Jul, PIPER PA36-375, VH-PXZ, Aerial agriculture,
OAKEY QLD 26S, Commercial, 1276 hrs
The operator of the aircraft had contracted to s pray 160
hectares of barley with weed killer. On arrival over the
property, the pilot fl ew an ins pection orbit and commenced
s praying the first paddock towards some tall t rees a nd a
powe r line. After this first pass t he a ircraft was pulled up
into a procedure turn before diving steeply over the same
obstacles, in the reciprocal direction. When the a ircraft was
clear of the obstructions, t he pilot attempted to level t he
aircraft for the next spray run . However, the ai rcra ft cont inu ed along its establ is hed fli ght path until striking the
ground in a pronounced nose high attitude. The impact
damaged the propeller, spray booms and landing gear.
Chemical sprayed ove r t he windscreen depriving t he pilot
of forward vision, and he was unable to control the subsequent landing run s ufficien tly to prevent the a ircraft
from broadsiding.
The aircraft was being operated at a weight in excess of the
Agricultura l Gross Weight and at a relatively slow airspeed.
During the pullout from t he dive, the load factor ('G'
loading) applied to the a ircra ft caused an aerodynamic stall.
The pilot was unable to effect a recovery at such a low
altitude .
14 Jul, MITSUBISHI MU2B-25, VH-MUK, Charter - passenger operations, TOOWOOMBA QLD, Commercial, 9500
hrs
The pilot stated that the wind was blowing directly across
t he strip and he joined t he circuit for a landing on runway
29. lie reported t hat when the aircraft was on final
approach it encountered a significant tailwind, and a missed
approach was carried out, fo llowed by a 'tear-d rop' style
turn to align the aircraft on final fo r runway 11. The pilot
stated that after touching down on t he mainwheels, t he
nosewheel was lowered and he heard a bang before the
nose of the aircraft contacted the runway. The a ircraft slid
along t he runway before coming to rest just off the sealed
surface.
An ins pection of the landing gear assembly revealed t hat
the nosegear downlock linkage failed due to overload forces
causing the nosegear to retract. The landing gear mechanis m was also bent by overload forces.
No evidence could be found to indicate that defects in the
landing gear system existed prior to this landing. It is possible t hat in selecting the propellers to t he Beta range and
applying heavy braking, prior to the nosewheel touch ing
down, that the nosewheel was forced onto the ground,
thereby contributing to this occurrence.
)
07 Aug, VICTA 115, VH-RQH, Instructional - check,
KAGARU QLD, Commercial, 3181 hrs
After takeoff the aircraft was flown to the local training
area where upper air sequences were carried out. Following
their successful completion the pilot was instructed to carry
out a practice forced landing. The first attempt resulted in
a s igni ficant undershoot and the aircraft was climbed to
2500 feet for a further attempt. On the second attempt the
aircraft was placed in a position too high and too close to
t he proposed landing strip, so the pilot under check decided
to fl y an 'S' t urn to lose altitude. During this manoeuvre the
a ircraft became grossly misaligned with the strip, the stall
warning horn was sounding intermittently and the
instructor instructed the pilot to go-around. However, the
pilot banked the aircraft steeply to the left to align it with
the strip, t he ai rcraft began to roll rap idly to the left and
despite the application of right rudder and full power it
struck t he ground. The nosegear and left maingear collapsed and the aircraft came to rest after a ground run of
39 metres.
13 Aug, DE HAV DHC2-MK1 , VH-HQE, Charter - passenger operations, HAYMAN ISLAND QLD, Commercial,
5300 hrs
The pilots departure from Shute Harbour aerodrome had
been delayed and he was running late fo r his arri val at
Hayman Island. During the short flight he noticed that the
cruising indicated airspeed was slightly less than normal,
but attributed t his to the possibility of water in the pitot
system, a problem that he had encountered the previous
day in another aircraft. On touchdown for the water landing, t he pilot realised that the wheels were still extended.
He attempted to prevent the floats digging in but the left
wing struck the water before the aircraft came to rest.
This accident was not the subject of an on-site investigation.
22 Aug, BELLANCA 8-GCBC, VH-SUT, Non commercial pleasure , BOONAH QLD 15SW, Private, 409 hrs
The pilot was approaching to land on an undulating 586
metre strip. A tow rope was connected to the aircraft, as
the pilot intended to tow launch a glider from the strip. He
aimed to touchdown well into the strip so that the t railing
tow rope would not foul the strip boundary fence. The aircraft floated longer than the pilot expected and touched
down at the commencement of the uphill A sloping section
of the strip. In an e ffort to stop the aircraft before reaching
the glider parked at t he end of the strip, the pilot applied
braking before the tailwheel had settled on the ground. The
aircraft subseq uently nosed over and came to rest inverted
on t he strip.
The pilot did not attempt to go around, as he was concerned
that t he tow rope might foul a fence during the climb out.
He had overlooked t he tow rope quick release facility availa ble to him . Neit her the pilot nor the operator had ensured
that t he stri p was s uitable for the proposed operation.
13 Sep, CESSNA 172-RG, VH-KOS, Non commercial pleasure, TOOWOOMBA QLD, Private, 153 hrs
The pilot was manoeuvring the aircraft on the apron to
pa rk adjacent to another parked aircraft. Whilst making a
right t urn he was observing the other aircraft which was to
his right, when the left wingtip struck a corner post of the
airport boundary fence . The pilot had observed the fence
pos t prior to commencing the turn and had assessed that
there would be adequate clearance for the manoeuvre. However, he fai led to continue monitoring the clearance with
the post during the t urn.
12 Sep, CESSNA 182 H, VH-PQB, Non commercial pleasure, HOXTON PARK NSW, Private, 93 hrs
The pilot reported carrying out a normal approach to runway 3 4 in lig ht and variable wind conditions. The aircraft
bounced on first touchdown and then landed heavily on the
nosewheel. Several more bounces occurred before the aircraft came to rest. The pilot taxied the aircraft back Lo the
parking area where he found that the propeller blades had
been bent.
After the initia l touchdown the pilot had attempted to correct t he bounced la nding by pushing the control column
forward.
20 Sep, CESSNA 210 M, VB-TIU, Non commercial pleasure, MT SANDON 22KM N, Private, 600 hrs
The pilot stated that he carried out a normal circuit at his
destination. During the landing roll he selected the flaps up,
and then inadvertently selected the landing gear up before
realising his mistake and selecting the gear down again. The
gear up selection occurred just as the aircraft was travelling over a hump in the strip and it is believed 'that this,
combined with the pilot holding up elevator, caused the
weight of the aircraft to come off the wheels. This resulted
in the landing gear safety switch becoming ineffective and
Lhe gear commencing the retraction sequence. When the aircraft came to rest the nosegear was fully retracted, the left
maingear was partially retracted and the right maingea1·
was still down and locked.
Subsequent inspection and testing of the landing gea1· system did not reveal any faults that could have contributed Lo
the occurrence. The pilot stated that he believed he had
mistakenly applied the after-takeoff checks instead of the
after-landing checks and had selected the gear up instead of
opening the cowl flaps.
This accident was not the subject of an on-site investigation.
09 Jul, CESSNA 210 M, VH-WRD, Non-scheduled charter
passenger, ROPER BAR NT 8741022
As the aircraft turned onto final , the pilot noticed a large
bird (later identified as a kite hawk) above and assessed
that the aircraft would pass beneath it. However, the bird
rolled over, dived and struck the windshield. The sudden
heavy impact smashed the perspex into small pieces which
cut the pilot about the face and chest. The broken windshield resul ted in a substantial increase in the descent rate
which required a considerable increase in power to overcome. A difficult landing was further complicated by a
reduction in visibility due to wind blast, blood and feathers.
Although the pilot's sunglasses and headset were knocked
from his head, had he not been wearing glasses it is probable that he would have been blinded as a result of the
collision.
The specialist ornithologist reported that large birds like
kite hawks and eagles have only one evasive manoeuvre
and that is to fold thei r wings and dive. llowever, if given
sufficient warning they will simply turn away from an aircraft. Given that they are adept at avoiding collisions, this
bird was caught unawares probably by the low power setting of the engine whilst the aircraft was on approach .
When surprised by the proximity of the aircraft it reverted
to instinct.
09 Aug, PIPER 25 235/ Al, VH-FAL, Glider towing,
BATCHELOR NT, Private restricted , 250 hrs
Soon after lift-off, whilst tow launching a glider, the aircraft was struck by two kite-hawks. One hawk smashed the
windshield and also struck the pilot in the face. The pilot
released the gl ider and made a normal land ing on the
remaining runway.
Although the pilot was cut about the face by the impact of
the bird and broken pieces of perspex , it is considered that
because he was wearing sunglasses at the time, he avoided
probable serious eye damage.
Rotary Wing
27 Jul, BELL 206 B, VH-PHX, Instructional - check,
BANKSTOWN NSW, Commercial - he licopter, 6020 hrs
One of the pilots was undergoing practice in engine failure
emergencies at night. The helicopter was equipped with a
':\ightsun' light, which was used to illuminate the ground
below the aircraft. Fixed Lights were also installed at the
edges of the helipad. During the third practice autorotative
descent, the 'Nightsun' light was inadvertently extinguished
when the aircraft was about 300 feet above the ground. It
was turned on again by the time the ai rcraft had descended
to abolll I 00 feet, and the remainder of the descent and
flare appeared to be normal. However, after touchdown t he
aircraft became airborne again, before touching down on
the heels of the skids while moving slowly forward. The
ai rcraft rocked forward and the main rotor severed the tail
boom just forward of t he tail rotor assembly.
Aviation Safety Digest 135 / xi
�The s urface of t he helipad had been softened by recent rain
,allow ing the heels of t he skids to dig in s lightly. This proba bly accentuated t he rocking movement which led to main
rotor blade contact with t he t ail boom. The type of
ma noeuvre being performed requires a high level of skill.
Should a slight error of judgement occur, there is little
o pportunit y for any corrective action to be successful.
Lighter than Air
23 Aug, THUNCOLT 240A, VH-WMS, Non commercia l pleasure, ALICE SPRINGS 5S, Balloon, 1100 hrs
The balloon operator had arranged a familiaris ation flight
for visiting travel agents. After some low and higher level
demonstrations, t he pilot descended the balloon to drift at
treetop level above the Todd riverbed . As he was aware of
power lines in the vicinity he elected to land on a clearing
jus t ahead. The pilot activated the rip panel which resulted
in a high descent rate and very hard landing.
The pilot became committed to the landing on unsuitable
terrain after choos ing to descend too early. The pilot of
another balloon, that had been operating in company with
this balloon, had delayed his descent a short t ime and made
a successful landing on an open area.
This accident was not the su bject of an on-site investigation.
The pilot reported that after the stall, he applied full back
stick to try to raise the nose, but to no avail. The aircr aft
stalled as a result of the steep climbing turn but recovery
was not effected d ue to incorrect stall recovery technique.
16 Aug, THRUSTER GEMI NI, NOT REG, I ns t ructional dual, WARRACKNABEAL VIC, Comme rcial, 1640 h r s
It was the student's fourt h fl ying lesson and t he effects of
power were being revised. The student t urned t he a ircraft
90 degrees to the left onto downwind but when he
attempted to level the wings a fter t he turn, the bank a ngle
increased from about 30 deg rees to 50 degr ees. The
instructor took over the cont rols and at tempted to recover
by applying right a ile ron , full power and hold ing the nose
u p briefly. Whe n the aircraft did not immed iately recover,
the instructor lower ed t he nose but the aircraft struck the
ground, in a lef t wing, nose low at titude, before full control
could be regained.
After revising t he effects of power, the engine speed was
set too low fo r t he aircraft to sustain a level tu rn. The
student maintained altitude by progressively a pplying up
eleva tor and t he instructor did not notice the incorrect setting because speed was assessed with re ference to the
ground in a 20 knot tailw ind. The instructor delayed taking
over the controls, because he t hought that the aircraft was
being subjected to mechanical turbulence gener ated by
trees, over which t hey were flying.
inner sur face of the strut. The strut had not been subjected
to corrosion prevention methods . An inspectio1~ cycle recommended by the manufacturer had not been followed .
)
Ultralights
18 Jui, FIRST STRIKE SUPERCAT, NOT REG, Non comme rcial - pleasure, BRISBANE QLD 66W, Other
(Foreign, Military, etc), 70 hrs
The pilot was carrying out circuit practice in his aircraft.
After about 15 minutes fl ying the engine stopped. Realising
that the aircraft would not glide to the strip, the pilot
attempted a fo rced landing in a grassed paddock just short
of the property boundary fence. Just after touching down,
the aircra ft s truck t he trunk of a fallen t ree and the landing gear was bent rearwa rds .
An inspection of the wreckage found that a hose cla mp
holding the fue l line to the inlet side of the carburettor had
fail ed and a llowed fuel to s iphon overboard. The failure of
the clamp had resulted from the incorrect size clamp being
used and t he resul tant size differential resulted in geometrical discont inuity a nd circumferential s tress overload. The
engine failed due to fu el exhaustion.
29 Aug, DRIFTER XP 503, NOT REG, Non co mmercial pleasure, MERIMAN QLD, None , 1000 hrs
On a rrival at t he property, the pilot landed t he aircraft in
front of the homestead. A short t ime later he departed with
the property ow ner on board for a cattle spotting flight. On
returning to land, again in front of the homestead, the aircraft hit a single power line, pitched nose up and fell to the
ground inverted. The pilot stated that he was not aware of
the presence of the power line prior to colliding with it.
25 Sep, ULTRALIGHT WINTON SAPPHIRE,NOT REG,
Non commercial - pleasure, DOYALSON AIR PARK,
Unknown/ not reported
The pilot had borrowed the a ircraft from his brother to
carry out some taxi training. He had previous ly flown
gliders . After making about 20 runs a long the strip the aircra ft became a irborne, the pilot decided to continue with
the takeoff as he was. uncertain if the a ircra ft could be
stopped in the remaining availa ble strip. The aircra ft colli ded with trees at the endof t he strip and became wedged
in the t ree tops. The pilot escaped from the aircraft uninjured and had to climb down the tree to the ground.
This accident was not the subject of a n on-s ite investigation.
26 J ui, ULTRALIGHT SAPPHIRE, NOT REG, Non commer cial - pleasure, BAIRNSDALE 12W, None, 225 hrs
After ta keoff the pilot purposely held the aircraft at a low
height above the strip to allow it to accelerate . At the
upwind end, he initiated a steep climb and a steep t urn to
t he right, however t he a ircraft stalled at about 150 feet
a bove the ground . The a ircraf t struck the ground heavily
and s lid into a ringlock fence. The pilot freed himself from
t he wreckage, and t he engine which was s till running at
high speed , was shut down by a s pectator.
xii / Aviation Safety Digest 135
FINAL UPDATE S (The investigat ion of the
following a ccid e nts has been completed . The
informa tion i s additional t o or replaces that
previously printed in t he pre limina r y r e port).
F ixe d Wing
26 Fe b 86, CESSNA 402, VH-MWF, Commercial, ROCKHAMPTON QLD, 1437 hrs
As the aircraft was climbing through 1000 feet t he pilot
not iced a reduction in mani fold pressure and fuel fl ow readings for t he rig ht engine. He advanced the right t h rottle and
found that the engine instruments ind icated that t he engine
was performing as if it was normally aspirated. A shor t
time later he sa w flames coming from t he right engine and
t he fire warning light and alarm bell activated. The fuel to
t he engine was s hut off but the pilot was unable to feat her
t he propeller. The fire did not go out. However , t he pilot
was able t o s uccessfully land the a ircraft at Rockhampton
where t he fire was extinguished.
An inspect ion of the a ircraft revealed t hat the number 4
cylinder was cracked a nd holed around the seat of the
exhaust valve. It is cons idered that t he cylinder cracking
and t he subsequent burn away of materia l resulted fro m
extre me operating temperatures. The torching of the combustion products through the hole resulted in the induction
manifold being consumed by fire .
It was also determined that the propeller could not be
feathered because t he propeller governor control cable had
become inopera tive a fter its mount poin t on the induction
manifold had been destroyed by fi re.
29 Dec 86, PIPER PA 34-220T, VH-F YU, P rivate,
COOLANGATTA QLD, 9 40 hrs
When t he pilot selected t he landing gear up after takeoff,
the gea r unsafe light remained on. Recycling the gear had
no effect. The pilot continued to his planned destination,
with the aircraft performing at about 10 knots below t he
expected speed. On a rrival, a visual inspection confirmed
t hat the right maingear was tra iling. The p ilot then carried
out a successfu l emergency landing, during which the right
fla p and propelle r sus tained damage as the gear collapsed.
Subsequent investigation disclosed that the right gear strut
had failed on takeoff from Mudgee. Examination of t he failure indicated that corrosion fatigue had initiated on the
0
17 Aug 86, PIPER 32 300, VH-PXY, Private, BANKSTOWN
NSW 2W, 200 hr s
The pilot, w ho was a part-owner of the aircraft, had
a rranged to t ake some friends on a scenic flight over
beaches to t he north of Sydney. The aircraft made an
apparently normal takeoff, into a wind of a bout 10 knots.
About one minute later , the pilot advised that an engine
fail ure had occurred and he requested a landing in the
reciprocal d irection. At this t ime the aircraft was at a
height of about 400 feet above the ground . Witnesses
observed the aircraft commence a turn with a bank a ngle of
a bout 30 degrees. Height was lost rapid ly, and after turning
throug h 180 degrees t he aircraft collided wit h the roof of a
factory and burst int o flames. The survivor escaped from
the left rear seat shortly before the front section of the aircraft fe ll t h rough the factory roof to the floor below.
A number of witnesses had heard the engine splutter before
the exhaust note died away, suggesting a problem with the
aircraft fuel system. lt was determined that the engine was
delivering lit tle or no power at the time of impact. No evidence was found of a mechanical defect or malfunct ion
w hich might have caused the power loss, and the reason for
t he apparent engine failure was not established.
At the point where t he pilot commenced to turn towards
the aerodrome, the a ircr aft did not have the necessary gliding per forma nce to reach the runway. The terrain ahead of
the aircraft in the takeoff direct ion afforded a greater
cha nce of a successful forced landing. The reason the pilot
elected to a ttempt to return to the aerodrome could not be
determined.
03 Sep 86, CESSNA 402, VH-RED, Commercial,
ESSENDON VIC 2 NNW, 11284 hrs
The fli ght was intended to return patients to their home
a rea following medical t reatment in Melbourne. After an
apparently normal take-off, the aircraft ceased climbing at
a bout 100 feet above ground level. In response to a query
from the Tower, t he pilot advised that the left engine had
faile d, that he was feathering the propeller and would
return fo r landing. The aircr aft was seen to be deviating to
the le ft, towards a large array of power lines. These lines
extend from about 40 feet to 90 feet above the ground, and
as the a ircr a ft converged with the ar ray it was probably
below t he height of t he u pper wires. The aircraft then suddenly veered to t he left and subsequently struck the ground
in a steep nose-down attitude. A fire broke out on impact
a nd destroyed much of t he wreckage.
The fin a l ma noeuv re performed by t he aircraft was typical
of that which occurs when one engine of a twin-engine aircraft is producing considerably less power than the other,
and a irspeed is reduced to below that required to maintain
d irectiona l cont rol. The pilot had reported that t he left
engine had fa iled , a nd the loss of control as described by
w it nesses was consistent with a red uction of power from
t his engine, combined with low airspeed.
The investigation of t he accident was hampered by the
extent of the fire damage. However, an extensive technical
examina t ion did not reveal any evidence of a defect or
malfunction wit h either the engines, t he various systems or
t he ai rframe which might have contributed to the accident.
Alt hough the pilot had indicated that he was feathe ring the
left propeller , it was determined that the propeller was not
feathe red at t he t ime of t he accident. It was not possible to
establish if t he pilot had subsequently elected not to initiate
fea thering action, orwhet he r such action was initiated too
late for it to be completed before impact with the ground.
The reason for t he loss of performance reported by the
pilot could not be established. It is likely that while t he aircraft was being manoeuvred to avoid the power lines and
return for a landing, t he airspeed decayed to below the
minimum req uired to enable adequate control of the aircraft
to be maintained . At t he point where control of the aircraft
was lost, t here was insufficient height available fur the
pilot to effect recovery. The reason continued flight was
attempted, rather than a controlled forced landing in open
areas prior to t he power lines, could not be determined.
13 Jun 86, PIPER 32 300, VH-BTL, Private, BROKEN
HILL 78NNW, 1090 hrs
The pilot was conducting a flight under Night Visual Flight
Rules from his property to Broken Hill. About 30 minutes
after departure the pilot reported t hat t he aircraft engine
was running roughly. Shortly afterwards he rep9rted that
the engine cowling had become detached and then that the
aircraft was on fire. No further transmissions were received
rrom the aircraft which was destroyed as a result or impact
forces and fire.
It was established that the No.3 cylinder became detached
from the engine crankcase and damaged the engine cowling
as it was forced outwards against it. The cowling blew back
against, and smashed the left windshield. Engine oil
escaped from the crankcase where the cylinder had been
attached, and was blown onto the cabin area. The likely
source of the fire was fuel escaping from broken fuel lines.
Engineering investigation revealed that the lower front,
half-inch cylinder hold-down nut ceased to maintain tension
on the hold-down plate. Other cylinder hold-down nuts from
this engine were examined and showed no signs of structural weaknesses. [t is considered that t he subject nut also
complied to specifications, although this nut was not
recovered. The engine had been overhauled 46 flight hours
prior to the accident. It is considered that the nut was
incorrectly torqued at that overhaul. The reason for the
incorrect torquing or the cylinder hold-down nut could not
be established.
The subsequent severe impact with the ground was a result
of the extreme distractions with which the pilot had to contend. The aircraft was cruising at 3500ft AMSL when the
engine disintegrated and the fire broke out. Part of the
emergency procedure for this type of occurrence is to di ve
the aircraft in an attempt to blow out the fire. As the aircraft impacted the ground in a steep nose-down but wings
near-level attitude, and only slightly off course, it is
thought that the pilot was complying with that drill. However, the low cruising altitude d id not afford him sufficient
Lime to accomplish this and establish the aircraft in a more
suitable attitude for a forced landing. His limited night fly ing experience in combination with a dark night might have
resulted in him not being able to estimate his height above
ground level.
28 Aug 86, CESSNA 421 B, VH-TWH, Senior co mmercial ,
PARAFIELD SA, 12500 hrs
The aircraft had not flown since December 1985 and had
been parked in t he open. The Maintenance Release had
expired , and a Permit to Fly was obtained to allow the aircraft to be ferried to Para.field for maintenance. When the
gear was lowered for landing, only the nosegear indicated
that it was down and locked. Recycling the system did not
result in locked indications being obtained for the maingear,
although to persons on the ground it appeared to be down.
During the subsequent land ing roll the right gear collapsed.
The a ircraft had been inspected prior to the flight and the
engineers had noted that the gear bearings were dry and
slightly corroded. They did not bring this to the attention of
the pilot and he did not detect the condition during the
preflight inspection. When the gear failed to fully extend
prior to landing, because of lack of lubrication and corrosion, the pilot discussed the situation with an engineer on
the aircraft and they decided that the fault was probably in
the gear posit ion indication system. As a result no attempt
was made to lower the gear using the emergency system.
10 Sep 86, BEECH C23, VH-AHB, Priva te, F ARRELL
FLAT SA, 148 hrs
The pilot hired the aircraft, a type he had not flown for
four years, for a trip to what he believed to be an authorised landing area (ALA). However, he did not check the
str ip condit ion prior to departu re for the ALA.
During the takeoff run at the ALA, the aircraft entered
thick grass located to the left of a ten metre cleared area
along the strip centreline. The acceleration of the aircraft
was retarded and the pilot, realising that the aircraft would
not accelerate to takeoff speed in the d istance remaining,
abandoned the takeoff. The aircraft stopped 64 metres
beyond the end of the strip after collid ing with two fence
lines and a road shoulder.
Aviation Safety Digest 135 / xiii
�22 Sep 86, PIPER 32 300, VH-SBH, Private, WAIKERIE
SA 56S, 1200 hrs
The a ircraft was being flown to Waikerie for a major
inspection . While the a ircraft was cruising at 2500 feet en
route, the pilot stated that he smelt smoke and almost
immediately noticed oil streaming over the windscreen. He
closed the throttle and commenced an approach to a large
paddock. The aircraft was landed without further damage.
The pilot vacated the aircraft via the rear door to avoid the
billowing smoke from the engine compartment and
attempted to extinguish the fire with a portable fire
extinguisher. On realising the attempt would be unsuccessful, he collected his luggage from the cabin of the aircraft
and cleared the area. The aircraft was subsequently
des troyed by fire.
Inspection of the rear of the engine compartment was
hampered by the degree of damage caused by the intensity
of the fire. The investigation did not discover any
malfunction that might have caused the fire.
27 Sep 86, DE HAV 82 A, VB-ART, Private, KINGSTON
SE SA, 167 hrs
During the takeoff run, the pilot reported that the aircraft
encountered a crosswind from the left. Despite the application of left rudder and aileron the aircraft continued to
drift towards the right of the strip. The pilot attempted to
manoeuvre the a ircraft over a gable marker but one of the
mainwheels struck the marker and caused the a ircraft to
turn further to the right. The aircraft continued and the
lower right wing was torn off after it struck a fen ce pos t.
The ai rcra ft came to rest 13 metres beyond the boundary
fence.
During the takeoff the wind velocity had changed
appreciably and the aircraft had drifted well to the right of
the strip before the pilot had attempted to take corrective
action. The takeoff was not abandoned until a fter the aircraft had struck the fence.
17 Oct 86, CESSNA 310-R, VH-DZH, Commercial,
PARAFIBLD SA, 703 hrs
On anival in the circuit area at Streaky Bay the pilot selected the gear down and obtained an instrument indication
that the gear was locked down. While the aircraft was on
final approach it encountered turbulence and the gear
warning horn sounded, the gear unlocked indicator light
illuminated and the nosegear down light extinguished . The
pilot initiated a go-around and after unsuccessful attempts
to obtain a gear locked down indication, diverted the aircraft to Parafield. On landing at Parafield the nosegear
collapsed.
Inspection of the nosegear revealed that the bolt which
secures the nosegear retraction linkage to the drag brace
had fail ed in the thread area due to fatigue. It is evident
t hat the bolt failed and partially withdrew in the circuit
a rea at Streaky Bay, giving rise to the unsafe gear condition.
31 Oct 86, PIPER PA32-260, VH-PYV, Private, ROBE SA,
311 hrs
Prior to the flight the J)ilot had an associate check that the
strip was serviceable. On arrival overhead the a irfield the
pilot chose to land on the shorter of the two strips into a 30
knot wind. During the landing roll, as the aircraft crossed
the other strip, the pilot observed that the strip had been
recently hoed. The nosewheel sunk into the soft surface, the
aircraft vee red to the left and the nosegear leg folded
rearwards.
The associate did not check the condition of t he strip but
advised the pilot that the s trip was "always okay". The
pilot did not check with t he owner of the strip to ascertain
its status, which at t he time of t he accident was undergoing
reconstruction. Although not required for an ALA, the
owner had placed a white 'unserviceable' cross adjacent to
the windsock. The pilot reported that he did not see that
marke r.
This accident was not the subject of an on-s ite investigation.
xiv/ Aviation Safety Digest 135
28 Dec 86, PIPER 32 R300, VH-BRG, Commercia l,
COOBER PEDY SA, 2026 hrs
Shortly after takeoff, the pilot discovered that the aircraft
had s uffered an electrical failure and he elected to return
and land. On selecting the landing gear down, he advised
th at he felt the a ircraft s low down and thought that the
gear was extended. No gear position lights were available
because of the electrical ma lfunction . During the landing
flare the pilot realised that the a ircraft was lower than normal, and applied full power "in an attempt to go around. The
aircraft settled onto the runway with the gear retracted
before the power application was able to take effect.
The reason for the electrical failure could not be determined. The pilot was unaware that, although the gear
extension system is hydraulically actuated, the hydraulic
pump is electrically operated and thus did not function following the electrical failure.
This accident was not the subject of an on-s ite investigation.
09 Jui 86, BEECH A23 24, VH-TYY, Private restricted,
CUNDERDIN WA, 137 hrs
The pilot was conducting the second leg of his first solo
cross-country exercise. He subsequently reported that during the takeoff t he aircraft failed to become airborne when
expected. Power was reduced in order to abandon the
attempt, but the aircraft then momentarily became
airborne. The pilot applied forward pressure ~o the control
column to place the aircraft back onto the ground, but a
heavy toucl\down occurred. The nosegear collapsed and the
aircraft slid for 183 metres before coming to a s top. After
vacating the aircraft, the pilot realised that he had
attempted to takeoff with a downwind component of about
10 to 15 knots.
The pilot s tated that he had not considered the wind direct ion prior to the take off attempt due to his feeling of
elation a fter success full y completing t he first leg of his first
solo navex. The runway assumes a down s lope past the
intersection and the pilot mis identified the gable markers
near the runway intersection as delineating the end of the
strip . From the position at which the aircraft came to rest
there were 9 17 metres remaining of the 1900 me tre strip.
17 Jul 86, CESSNA A188B Al, VH-SUA, Commercial,
ROCKY GULLY 15E, 948 hrs
During the course of the day 's activities, the pilot had
landed at the strip on 24 occasions. The surface was wet
and landings had been made with a quartering tailwind. On
each occasion the pilot had stopped the a ircraft about 100
metres short of a cattle yard at the end of the strip. The
pilot was making his first approach after cha nging operations to a nother paddock. The ai rcraft touched down about
100 metres beyond the previous touchdown area. However,
the pilot continued with the landing and despite heavy
braking he was unable to prevent t he aircraft colliding with
the fence of the cattle yard.
It was reported that while the aircraft was on approach the
wind strength increased to about 15 knots.
31 Jul 86, CESSNA Al88 A2, VII-DOD, Commercial,
ESPERANCE WA 120W, 500 hrs
The pilot was engaged in the s preading of urea. During the
operation he had observed that the a ircraft was not performing as well as normal. He carried out a trouble check
and after the completion of s ome rectifications and an
engine run, believed he had rectified the proble m. Six more
s orties were completed without problem. However, s hortly
after takeoff on the next sortie the engine again partially
los t power. The pilot decided to return and land, but not
dump the load. During the turn toward the a irstrip the aircraft stalled and impacted the ground with the left wingtip.
The investigation determined that the loss of engine power
was caused by a faulty magneto and contributed to by t he
generally poor condition of the engine. The engine had not
been operating norma lly for some t ime, and attempts to rectify the problems , by unlicensed ma intenance personnel,
had not been successful.
)
04 Oct 86, MOONEY M20J, VH-SXT, Commercial, PERTH
WA, 3900 hrs
The pilot in command estimated that t here were
approx imately 26 gallons of fuel in the tanks before the
flig ht commenced. They intended to conduct exercises in the
training area for about 20 minutes, followed by a series of
ci rcuits and landings. Shortly after takeoff for the fifth circuit, the engine failed. The pilot in command took control,
selected the landing gear down, and attempted to hold the
aircraft off the ground until the gear had extended . However, touchdown occurred wit h the gear only partially
extended and the aircraft s lid to a halt on the runway.
The aircraft had not been refuelled following a flight of 4.8
hours duration. The estimate of the fuel remaining onboard
the aircraft was based on the reading from a fu el metre
that subsequently proved to be unserviceable. When the
engine fai led , due to fuel exhaustion , the aircraft had been
a irborne for 1.1 hours and the ex haustion of the fuel
s upply was consistent with the flight time since the las t
refuel.
11 Oct 86, CESSNA Al88 A2, VH-KVA, Private,
KALANNIE WA 30N, 562 hrs
Before commencing spraying operations, the pilot discovered that the left maingear tyre was deflated. The tube
was patched, however about half way through the spraying
task the pilot noticed that the t yre was partially deflated .
Air was added to the tyre, and the operation was continued. On t he last landing for the day the left gear comm{'nced to vibrate and the aircraft veered to the left. The
pilot was unable to maintain adequate directional control,
and the ai rcraft entered t he crop at t he s ide of the strip
before ground looping to a halt. The left main tyre was
found to be flat.
15 Oct 86, CESSNA 150 M, VH-WNT, Private, GASCOYNE
JTN 70NE, 400 hrs
On t he day preceding the accident the station manager was
informed that the pilot hired to carry out t he muster wou ld
be late in arriving. He asked Mr Mainwaring, who was
employed as a stockman, if he wou ld carry out spotting
duties until the other pilot a rrived .
About 20 minutes after the operation had commenced, t he
ground pa rty heard the sounds of a n aircraft impact. The
pilot stated that he had been fl ying at between 400 and 500
feet above the ground when he lost control of the aircraft
in a turn. The aircraft was discovered to have struck the
ground while in a nose-low, s talled condition. The engine
was not developing power at the time of impact, however
no defect was subsequently found w ith t he engine or systems of the aircraft. The pilot did not hold a mustering
endorsement and had appa rently not received forma l training in low level operations.
22 Dec 86, BEECH C23, VH-SHP, Private, BIG BELL WA
lSW, 4419 hrs
The pilot was carrying out a check of the station windmills
prior to commencing mustering operations. About 15 minutes a fter departure he reported that an acrid smelling gas
entered the cabin. lie turned off the radios, the mas ter
switch and closed the cabin air vent and diverted to the
nearest suitable strip. En route the acrid smell intensified
and as the pilot was having trouble breathing he decided to
land the aircraft in a nearby clearing. The t hrottle was
closed in an endeavour to reduce the fumes but reapplied
when this was not successful. However, the engine did not
respond and the aircraft was landed short of the cleared
area. During the landing roll t he a ircra ft collided with trees.
Followi ng the last engine start t he starter relay contacts
remained closed due to internal .:orros ion, this resulted in
the motor continuing to operate. The continuous operation
of t he st a rter produced enough heal to melt the nonstandard engine earth strap at t he attachment point to the
firewall . Earth was then made through the tachometer
cable and magneto switch leads, which overheated and
burnt causing the mag netos to earth and the engine to
subsequently fail.
21 Feb 87, CESSNA A188B-Al, VH-HOP, Commercial,
THANGOOL QLD 44NW, 1064 hrs
The pilot was engaged in the spraying of a crop of beans
and had successfully completed several spray runs. At tlw
commencement of the next spray run the a ircraft flew into
power lines which struck the main landing gear. The a ircraft s ubsequent ly struck t he ground in a st.eep·nose-down
attitude, then nosed over and came to rest inverted some 73
metres beyond the point of collis ion with the wires.
The pilot's memory was affected by trauma suffered in Lhe
accident and he cou ld not remember details of the wire
strike. Consequently, a reason for the wire strike was not
established. However, it was noted that the power Jines
were oxidised and that the span between the poles was
quite long. Both of these factors could have adversely affected the pi lot's ability to see the wires against t he natural
background.
17 May 87, PIPER 32 300, VH-TPJ, Private, SWEERS
ISLAND QLD, 1038 hrs
The pilot reported that just after touchdown he felt a
bump. As the aircraft s lowed the nose of the a ircraft sank
s lightly, allowing the prope lle r to strike the strip s urface
several times. An ins pection of the aircraft revealed that a
wallaby had struck a nd bent the nosegear strut.
This accide nt was not the subject of an on-site investigation.
15 Apr 87, BEECH 200, VH-MSZ, Commercial,
TJBOOBURRA NSW, 4575 hrs
The pilot was making a night la nding approach. Late in the
flare a thump was heard , and s hortly a fter touchdown the
nosegear collapsed. The aircraft came to rest on the s trip
390 metres further on. It was discovered that a large kangaroo had struck the nosegear, and that a number or other
ka ngaroos were in the immediate viciniCy.
This accident was not subject to an on scene investigation.
04 Jan 87, CESSNA U206 A, VH-RPZ, Commercial,
PAKENHAM VIC IS, 1100 hrs
The two parachutists were prepa ring for a jump in which
one pulled the other from the a ircraft. During the fin a l
stages of the prepa ration, the reserve parachute of the
front jumper prematurely deployed. Both persons were
ej ected from the aircraft, and the lead ing jumper s truck t he
tailplane. A portion of the horizontal stabiliser was torn off
and the aircraft pitched down beyond the vertical. The pilot
was unable to regain any control, and, with some difficulty,
abandoned the a ircraft. He deployed his parachute at about
500 feet above the ground, and landed safely . The parachutist who had s truck the tailplane wa<; initially rendered
unconscious, and had suffered a broken right a rm . She
recovered sufficiently to deploy her ma in parachute and
control her descent when close to the grou nd . The aircraft
was destroyed when it impacted the ground in a steep nosedown attitude at high speed .
The inadvertent deployment of the reserve parachute was
probably caused by the body movements of the parachutist
as she moved to her jump pos it ion outside the aircraft. The
most Likely explanation fo r the inadvertent deployment was
that either the securing pins were not engaged correctly or
that the rip chord was too short. The rip chord was not
recovered.
26 Apr 87, PIPER 28 180, VH-DMB, Commercial,
MATARANKA HS lSW, 1470 hrs
.Just a fter the aircraft reached the top of climb, at 1000 feet
a bove the ground , the engine fai led. The pilot was unable to
rectify the problem a nd decided LO land the aircraft on a
road. During the landi ng roll t he left wing struck a road
sign and the aircraft ran off the road , then travelled a
further I 00 metres before colliding with a tree.
Engineering investigation revealed that the stepped dowel
used to align the cranksha ft liming gear had failed. This
resulted in the cranks haft and camsha ft timing being 30
degrees out of a lignment, hence the ina bility of the engine
to deli ver any power. The stepped dowel fail ed due to the
cranksha ft timing gear reta ining bolt being incorrectly
torqued wh ich a llowed the gear to move on the cranks haft
a nd eventually s hear the dowe l. The e ngine had been overha uled prior t.o the occurren ce and ii. is like ly that the bolt
Aviation Safety Digest 135 / xv
�was incorrectly torqued due to oil or dirt being located
between the gear and the crankshaft during engine
reassembly.
Rotary Wing
16 Jui 86, ROBINSON R22-ALPHA, VH-UXV, Commercial
- helicopter, CAMDEN NSW, 2200 hrs
An exercise in emergency procedures was being carried out
in the circuit area. A number of landings were completed,
with the instructor simulating a jammed tail rotor pedal. On
the last landing, a jammed right pedal was being simul ated.
After a standard approach for the circumstances, the
student flared at about 45 centimetres above the ground
and at a speed of about 15 knots. As he then began to
reduce power, the engine apparently suffered a substantial
loss of power and the aircraft landed heavily. The left landing skid dug in , and t he helicopter somersaulted before
coming to rest on its right s ide.
No fault or defect was subsequently found with the engine
or its systems which might have explained the reported
power loss. Atmospheric conditions at the time of the accident were conducive to the formation of carburettor icing,
particularly during descents with reduced power. The pilots
had not used carburettor heat during the approach, possibly
because the carburettor air temperature gauge was indicating a temperature just above the caution range. This instrument was later found to be reading in error by 9 degrees.
The pilots had not checked the reading of the gauge against
the ambient temperature prior to engine start, and were
therefore unaware of the malfunction.
When the power loss occurred, the helicopter was in such a
position t hat it had contacted the ground before the
ins tructor could in itiate any corrective action .
11 Jui 86, BELL 47-GSA, VH-LEF, Commercial - helicopter, OLD DELAMERE 20SE, 4015 hrs
During mustering activities the aircraft was operating
between 50 and 80 feet above the ground, when the engine
suddenly stopped. The wind at t he time was a quartering
tailwind, and during the attempted autorotation the aircraft
struck the ground in a tail-low attitude. The tail boom was
severed, the aircraft bounced, spun to the right and came to
rest with the la nding skids collapsed.
An inspection of the engine revealed that the magneto idler
shaft had s heared due to overload caused by foreign objects
fouling t he magneto drives. The foreign objects were identified as crankshaft flange bolts which had been incorrectly
torqued at overhaul.
25 Mar 87, HUGHES 269 C, VH-PHK, Commercial - he licopter, MAREEBA QLD 31S, 135 hrs
On the previous day the pilot had ferried the aircraft to a
maintenance organisation for a scheduled ser vicing. No
abnormalities were discovered and a satisfactory engine run
was carried out by the pilot prior to departure for the
return flight. A search was commenced when the helicopter
did not arrive at the destination, and t he wreckage of the
a ircraft was located a fter a VSB signal was heard. The aircraft was lodged in the branches of a tree some 18 metres
above ground level. The tail boom was lying near the base
of the tree and most components had received substantial
impact damage.
Examination of the wreckage revealed that the engine had
failed during flight. This was caused by a fatigue failure in
the number 2 cylinder connecting rod big end cap. The damaged end of the connecting rod broke away a large piece of
the crankcase housing the lubricating oil gallery. This led to
overheating of bearings through a lack of essential lubrication. The fatigue failure of the connecting rod end cap
was cons istent with failure caused by the connecting rod
bolts being insufficiently torqued. The terrain over which
the aircraft was flying was unsuita ble for a forced landing.
Gliders
25 Oct 86, SCHEMP NIMBUS 2, VB-GEL, Glider, LAKE
KEEPIT NSW, 500 hrs
The pilot was approaching to land in strong crosswind conditions. The area near the threshold of the strip was
obstructed by machinery and another glider, and the usable
strip width was reduced because of long grass. Although
there was adequate strip length, the pilot elected to land
close to the other glider. During the landing flare the aircraft drifted towards the obstructions, and the pilot raised
one wing in an effort to avoid them. The other wing entered
the long grass and the aircraft slewed sharply before falling
to the ground.
This accident was not subject to an on scene investigation.
22 Nov 86, GLASER-DIRK DG 400, VH-HDE, Glider,
GA WLER SA, 3000 hrs
Before lining up for takeoff, the motor glider pilot estimated that there would be sufficient time for his takeoff to
be completed between a landing glider, and the tug aircraft
that had just joined the circuit. The takeoff was delayed by
the time taken to clear the landing glider from the strip.
The tug aircraft, just prior to turning final, was observed to
increase power and head towards the departing motor
glider which had just commenced its takeoff run . It passed
low over the motor glider and the tow rope struck the right
aileron of t hat aircraft.
The glider pilot had lined his a ircraft up for takeoff on the
strip the tug pilot intended to use for landing. The tug pilot
stated that his intention was to teach the glider pilot a
lesson not to attempt to takeoff in front of him again. In
taking this action the tug pilot forgot that the tow rope was
still attached and trailing his aircraft.
22 Nov 86, GLASFLUGEL LIBELLE, VH-GYN, Glider,
BORDERTOWN SA SN, 258 hrs
The pilot was competing in a cross country gliding competition when it became apparent to him that an outlanding
would be necessary. He then pos itioned the glider to carry
out a circuit for a landing in a paddock. After turning the
aircraft onto final approach and deploying fu ll airbr ake, the
pilot noticed that the indicated airs peed had greatly
reduced. He then attempted to close the airbrake but the
nose of the aircraft dropped and struck the ground. The aircraft bounced on impact and came to rest 17 metres beyond
the initial point of impact.
14 Jan 87, ENTWICKLUNG PHOEBUS, VH-GYC, Glider,
MARYBOROUGH 13SSW, 3000 hrs
The pilot was returning to land after a period of
thermalling flight, when severe turbulence was encountered. The pilot's head hit and broke the canopy, and he
then had problems with his vis ion. Heavy s ink was a lso
experienced, and an outlanding was attempted in a cane
field. The area selected was a 5 metre wide strip between
a reas of cane growing to about 1.7 metres in height. The
left wing caught in the cane and the aircraft slewed
v iolently before coming to rest with the wing completely
torn out of the fu selage.
Ultralights
05 Jun 87, HANG GLIDER ULTRATRIKE, NOT REG,
Hang glider, HOLBROOK NSW 4N, 300 hrs
Although the pilot was experienced in operating unpowered
hang gliders, he had only limited exposure to powered versions . He had been conducting a short local flight, and
subsequently advised that he had probably misjudged the
landing flare. The aircraft struck the ground in a relatively
steep nose-down attitude. The la nding gear collapsed and
t he aircraft overturned before coming to rest on the flight
strip .
This accident was not s ubject to an on scene investigation. -
One of the major roles of the Bureau of Air
Safety Investigation is to interpret the accident
and incident statistics and to recommend ways
to prevent or at least reduce, recurrences. BASI
has just completed its latest study - into accidents and incidents which involved fuel starvation and fuel exhaustion. It came about
because approximately one third of all enginefailure accidents since 1969, were fuel related.
The res ults are published in a report which is
being dis tributed free-of-charge to all registe red
training organisations in Australia. It is titled:
AUSTRALIAN AVIATION OCCURRENCES
INVOLVING FUEL STARVATION AND
EXHAUSTION, 1969 - 1986
BASI Report Number 87 - 116
ISBN 0 644 06463 3
The r eport is also on sale at Australian
Goverment Bookshops for $3.95.
The study found that the 'human factor' was
again the culprit in most cases. Fuel starvation
frequently arose from mismanagement of the
fuel system while fuel exhaustion was more
commonly the result of inadequate pre-flight
preparation.
The report makes recommendations for both the
industry and the Department to reduce the incidence of similar occurrences in future. The
major recommendation to industry is for consideration of fleet standardisation with regard
to fuel selection and management systems and to the Department, for a pilot education
program on fuel-management related topics.
BASI is currently undertaking other studies into landing accidents and the relationship
between pilot experience a nd accidents or incidents. These reports should be released shortly.
For further information, contact:
Mr Conn Copas
Bureau of Air Safety Investigation
062 68 4080
Aviation Safety Digest 135 / xvii
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I
YEAR
I think you have rL very valid point, Margaret. I
would like to see the Digest reach every student
during the early stages of his or her training.
Unfortunately, the turnover in students who
begin training and for various reasons discontinue, means it is almost impossible to keep
track of all active stildents witho·ut the enormous cost of sending copies to everyone who
only does a TIF.
The soliltion is to send a batch of ten or so
copies to every ground and flying training
organ·isation and to ask the Chief Instructors to
encourage their students to read and discuss
the issiws. Th·i s method rel?:es of course on the
motivation and dedication of the instructors
but ultimately I bel'ieve that is the case anyway.
In any event we'll give it a try for a while and
see what response it receives.
I
The Manager
Aviation Publication Distribution Cantre
P.a Box 1988
CARL TON SOUTH 3053 (Australia}
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Dea r Sir,
The point I wanted to raise is the non-issuing of
you r Digest to student pilots. I understand from
learned pilot friends that the attrition rate is
high and that ins tructors (one I know) constantly drum safety into students. Reading your
articles, though, reminded me of many years of
potentially lethal 'hit and miss' trials of keeping
my car on the road and managing my washing
mach ine.
One surel y cannot assume that most instructo rs
will relay most of these extra safety t ips e.g.
cleaning the oil slick from the appropriate
places to avoid loss of w indscreen vision
(Aut umn 1987 Digest).
The best learning, unfortunately, seems to take
place on the 'rocky roads '. Would it not help to
present these to students prior to setting off?
Margaret Safron
Dear Sir,
I was surprised to see my pri vate letter (Bush
techniques - Survival) published in the last
Digest. As it could not be made clear that this
guide was written to a 350 hour pilot (with a
brand new instrument rating) proceeding to the
Solomon Islands several year s ago, some
readers could possibly assume all recommended
procedures were applicable to Australia. Most,
but not all.
I do not w ish to be held accountable for the
consequences of Australian pilots attempting
Papua New Guinea and Solomon Island bush
flying procedures here. Therefore, I'd like to
clarify cer tain aspects of the guide. Gap flying,
low flying and pressing on visually in poor
weather have no place in Australian flying
operations (wit h the exception of low flyi ng in
ag work). The main reason PNG style flying can
easily be fatal here is the profusion of wires
strung over the count r yside. Impor tantly, with
reference to VFR -
my original letter 'stated
'In the tropics, Australian VFR rules don't
apply, etc' (I meant PNG and the Solomons).
The stress of weather up there, especially during 'the wet', necessitated different techniques
to cope - and nav-aids were rare. Waiting for
VMC wou ld mean being permanently grounded.
Certain 'contentious' aspects should be viewed
in the light of logical priorities and advice given
to one so in experienced venturing into equatorial, mountain and island flying for the fi rs t
time .
• Practising instrument fly ing w ith maps on the
windscreen was recommended only for the
Solomons where there's little traffic and full
radio reporting. Above LSALT, for short
periods and without passengers w as about the
only way (albeit illegally) to retain currency/
IFR skills . Around Camden such a practice
would be fatal.
• 'Harmless lightning' - was mental conditioning (like ignoring flak) to avoid panic and
ensure the priority of controlling the aircraft
in severe turbulence.
• 'Fuel overload' - the lesser of two evils and Solomons only, (long overwater flights
are n ormally to/ from longer ai rstrips) considering type performance. I am dead against
blatant overloading but know of several cases
of fuel exhaustion (some fatal) and was concerned (given his low experience) that 'Dan '
may get caught-out fly ing in 'the wet' on
island ops. If he made a mistake - my
preference was - ' a little too much fuel' .
While it was true that cer tain procedures recommended were slightly less than legal (even
up there) the aim of the exercise was survival.
Such techniques have been used in PNG for
many years where common-sense is a prer equisite for survival. My intention was to pass on
some hard-won experience to an above average,
but inexperienced pilot. 'Dan' came through , I
hope I helped a little.
signed
ex-PNG bush pilot
Dear 'Bush Pilot',
I am indebted to you for both your letters. In
the transcription of your original letter there
was an error - what should have read, 'In the
bush, (meaning PNG and the Solomons), Australian VFR rules don't apply,' was incorrectly
written as, 'In the Australian bush, VFR rules
don't apply.' I share your concern regarding
possible mis-interpretation by ine:x:perienced
pilots and indeed this was one aspect that
caused m e to consider not publishing the letter.
Now that your intent is clear, I value more
than ever the 'wisdom' of your original advice.
Than k you.
�Aviation Safety Digest
Aviation Safety Digest
135
135
1ll:a
- - - Dear Sir,
Dear Sir,
During my t raining I had an incident w hich has
My eyes are di m, bu t I CAN sec, thanks to tr imade me ext r emely cautious as f ar as checking
focals. I hasten to write in their defence after
a ll systems very thoroughly before I attempt to
t he somewha t less tha n en t husiastic comments
take off. The incident is as follows:
in Lhe article on p ages 22 a nd 23 of Aviation
Saf ety Digest No. 133.
I had reached the s tage of going solo but only
to do a few circuits . My very thorough and
My sight followed Lhe basic pattern - pe rfect
competent ins tructor told me Lo do four circuits
Lill my late forties w hen the arms became too
and I was ins tructed to come to a full stop and
short. In keepi ng with av iation requirements I
return to the threshold before each takeoff. I
went to bi-focals (even t hough t here was no
had completed t hree circuits and landings quite
correction in t he top h a lf). They nearly drove
s uccessfully.
me mad. As the years passed, I had t wo
I was just airborne after the fourth takeoff
changes in the reading prescription and was
when I discove red I cou ld not gain altitude. I
irritated every time I had to tilt my h ead back
noted each time I pulled back on the yoke my
to read clearly the ins trument p anel of t he
flying speed fell alarmingly. After two more
plane or car. I t hen t ried the graduated lenses
attempts Lo establis h my climb attitude, I flew
but they and I were not compatible so I went to
down the strip, ' porpoising' and just managed
tri -focals. They are the best t hi ng sjnce Bleriot
to clear t he aerodrome fence . I became quite
crossed Lhe ch annel.
alarmed at the situation - being a s tudent of
With scarcely any head movement, I can clearly
only a fe w hours experience - and a lso realisread ALL the instruments and by looking down
ing I had to clear a hill about a mile away from
through
the r eading section, can equally cle arly
t he aerodrome.
read
maps,
flight plan etc. And far vis ion is just
A quick glan ce ouL of the cockpit s howed that I
as
easy
.
I
would
certainly have to agr ee that
was crawling through the a ir s o I ha d a careful
for normal a nd less interesting occupations such
list en to t he engine. It was performing quite
as bench work or (worse) house-work, the
normally . At this point I decided Lo take a grip
middle segment IS too s ma ll , but for fl ying (or
on myself and falling back on my thorough
driv
ing) I have never had a sin gle moment
training, I went through a systematic cockpit
when
1 have found the middle segment less
check and dis covered I was try ing to take off
than
optimum.
On my glasses this seems to be
with 30 degr ees of flap!
about 7-8 mm in depth, but I can 't see too well
At the time I was flying a Cessna 150 Aerobat
without my glasses! So, if your eyes ARE dim,
which was noted for its poor performance even
t hen I strongly recommend you to 'tri-focals'.
when things wer e normal. As soon as I retracted the flaps I climbed aw ay quite normally and · Since I'm writ ing, I might as well add my comcofQpleted my circuit and landing - much to
ments on s tatements in conclus ions 3, 6, 7 , 8
and 9. Conclusion 3 states' ... ther e is evidence
my relief.
that [difficulty in seeing charts and manuals]
I hope th at you consider t his a rticle wor thy of
arises in part t hrough the prescription of
publication because I feel it is an excellent
glasses to ensure clear vision for ins truments at
example of how disaster can be the result of
the cost of t he a bility to see cha rts and
one simple moment of carelessness.
manuals.' It h as been my opthalmological
Yours fait hfully,
experience t hat t he patien t h ad a lar ge say in
W.J . McKillop
w hat (s)he needs and wants, especially w here
t he basic problem is on ly ageing.
During circui t training there is a very r eal
Conclus ion 6 conce rns sunglasses . I, a long with
danger of m'issin'g the pretakeojj' v ital actions
the r est of t he two-thirds of pilots, like to wear
in a stop-and-go or where the aircraft is taxied
sunglasses
when flying, to combat the glare.
back for a further circ·uit. The only p rotection
Probably illegally, my second compulsor y set of
of course is to complete the checks as if every
prescription glasses are therefore (tri-focal)
takeoff is the f irst.
s unglasses .
Jn your case, the flap setting represented a
serious haz ard. Jn another air craft an incorConclusion 7 - charts. The Department is to be
rect trim positi on can be sufficient to cause loss
reproached for its economy in reducing t he size
of control.
of the aerodrome diagrams. And whilst nobody
r eally wants to carry any MORE p ap er in t h e
We are all vulnerable to thi,s insidious trap cockpit, YOU try r eading t he NDB for Cobar on
irrespective of our experience. As I said, the
a VEC chart, or worse, in the ERS, whils t trying
only protection is to run through the pretakeoff
Lo fly a light aircraft without auto-a ids in s umvital actions from beginning to end before
mer turbulen ce.
every takeoff.
Conclus ions 8 and 9 . Fortunately I don't fly aircraft with over head panels or oxygen masks
and I know I couldn 't read the first or wear the
second with ANY glasses. This problem is not
specific to TRI-FOCALS. Anyone confronted
with these problems has my sympathy.
Be seeing you.
Re seeing you.
Be seeing you .
I3everlcy F. Young.
PPL
As you have found from personal experience,
B everley, tri-jocals do work in some - perhaps
m any, cases. The general caution about trifocals was based on some problems discovered
in A merican use. Their sititability for you in
your aircraft can only be determined by trial
and very much depends on the care with which
the pilot's requirements are explained to the
opthalmologist.
There has been tremendous interest in this
topic and so I will be publishing a major
article in the next issiie which will include
advice as to how to define the power and size
of the segments to suit each individual
requirement.
Your point about the paperwork is noted and I
wou ld appreciate suggestions as to how aeronautical information can best be presented to
GA pi lots.
Dear Sir ,
I read with interest, in the Aviation Safety
Digest on 'The Human Factor', your article on
Ratbaggery and enclose a photo, I consider, of a
ratbag in action.
In 1981 my wife and I, with friends, were on a
flying trip in a Cessna 172 and landed for fuel
at Maroochy Airport. As we were taxiing to the
fuel pump my wife noticed a helicopter following behind, spraying vapour, and managed to
take the accompanying photo through the rear
window.
When we stopped, the helicopter hovered above
us and dropped a very unpleasant smelling oily
substance, completely enveloping our aircraft.
Of course, we quickly closed the windows in an
endeavour to prevent Lhe vapour entering.
We concluded from his action that the helicopter p ilot had expected us to allow him to
receive fuel first. Apparently this was the penalty. In my opinion, this pilot was a ratbag.
Name and Address supplied.
It's difficult to understand the attitude of
someone who would do a thing like this.
Fortunately, such an alt'il'u de is rare in
aviation circles. Let's hope U stays that way.
�l
Aviation SafetyDigest
135
What goes up
may have
trouble getting
down
The following account of a glider pilot's encounter with an
intense frontal passage has a message for all of us
WAS LAUNCHED in my ES60 Boomerang
from Bridgewater just after four o'clock in
_ the afternoon. The wind was vary ing a bit
but was generally from the north. A very high
cloud base was reported and some of the club
pilots were going to attempt a 'Gold C' height gain.
The tow was quite satisfactory - a bit turbulent but it was not difficult to maintain station
behind the Auster. I eventually released in moderate turbulence while we were orbiting a large
thermal at 1700 ft agl. This took me up to
7000 ft. The thermal varied considerably in its
strength and width, so that sometimes I had to
turn very steeply and at other Limes a wide,
leisurely circle kept me in the lift. I had to
work at it t hough and I felt that, while my
centring ability could be improved, that wasn't
the whole trouble.
At 7000 ft the lift was still there and I was still
several thousand feet below the main cloudbase. I thought I'd fly around for a while, so I
flew over to the Bridgewater township, about
four miles NW of the airfield.
The breeze was quite stiff and I didn't encounter any more lift. By now I was down to 3000 ft
and so I headed for home. About halfway back,
still at 3000 ft, I found another good thermal
(or the original one) which I worked to 5000 ft.
During this time I saw several other gliders, all
below me, including a Ka6 and a Libelle, then
subsequently the Golden Eagle, a beautiful
antique glider which I watched admiringly for
quite a while.
I noticed that operations were continuing on the
field and that aircraft were still taking-off into
the north.
At 5000 ft, I was a little disturbed to find the
a ir rather hazy, even though the base of my
own cloud looked to be thousands of feet above
me. Other cloud bases I could see were a ll at
comparable height.
I
I could now sec heavy cloud formations about
twenty miles to the south-west extended right
down to ground level, and I thought iL looked
like an intense cold front.
I was painfully aware that I knew very little
about fronts, other than that they sometimes
arrived very suddenly with a marked change in
wind direction and with some violence - winds
which had been known to tear well tied-down
gliders from their anchorages and cause severe
damage. Behind the front there could well be
continued high winds for a period, and sometimes heavy rain and thunderstorms.
Of their effects at altitude, I was uncertain
although I knew there could be severe sink just
behind them.
I considered these factors and decided to commence a descent. I had been fl y ing for about an
hour and a half and although I didn 't like leaving good lift, nor did I relis h the thought of getting caught in a front.
While the alarm bells had commenced ringing in
my mind they were not very loud and the presence of the Golden Eagle, still about .fifteen
hundred feet below me, was very reassuring. Its
crew were very experienced , and they wouldn't
risk damage to their beloved old glider.
I flew upwind (to the north) for about two
miles at 60 knots and I then turned back
towards the airfield. I could see the tug doing a
very long final approach , about a mile it
seemed, from the s outh.
I always trim to speed. I trimmed nose down
for this speed and there the trim s tayed for the
rest of this flight.
When I arrived back at my starting point, I was
still at 5000 ft. I opened the air-brakes and
completed another two mile run to the north - ·
this time deviating to the right and left considerably - actively searching for sink, and
ready to circle in it when I found it. The air
was turbulent but not alarmingly so, and everywhere I went I found either broken lift, or at
best, no sink. I was now cruising at 65-70
knots, trim forward, brakes open.
Five minutes later, I was at 5500 ft, and the air
had a peculiar dark colour, with patches of
haze sweeping past. The cloud-base was still
several thousand feet above me, extending
about twenty miles to the south-west, where
the full , but multi-coloured cloud-bank extended
all the way down to the ground. By multicoloured, I mean that some were typically blueblack and some grey, with sharp definitions
between the banks. It was like looking horizontally at a vertical stormy sky, instead of looking up at a horizontal s ky.
To the east I could see Bendigo, apparently
underneath the same huge cloud.
In the distance, further south I could see the
bases of several other large clouds, also much
higher than me.
I then carefully r eviewed my s ituation a nd the
options that were open to me.
I didn't want to get caught in the intense front,
which was what I certainly faced - I could
now see huge dust-clouds rolling along Lhe
ground ahead of the front .
I'd heard of glider pilots flying ahead of a front.
and eventually landing successfully. Indeed I
had r etrieved a pilot who had successfully done
this. But on that day, our Club CFI had been
most critical of the exercise, pointing-out that a
landing in high winds was still inevitable, with
possible risk of injury and damage or loss of
the glider.
I then considered staying airborne until it
passed, but I was deterred by the possibilities
of poor visibility in heavy cloud behind the
front, with accompanying rain and by now I
appeared to be well in the grip of a powerful
cu-nim and the thought of my glider breakingup and my being swept up and flung down
several thousand feet on the end of my parachute didn't appeal to me one little bit.
The front still looked to be twenty miles away,
so I decided to use all the height-loss techniques
available to me and to land back at the airfield.
At least there I could expect help in handling
the glider on the ground when the inevitable
high winds came through , help which I felt I
was sure to need and which would not be available if I outlanded.
The brakes were still open and I was circling
fairly tightly, carefully considerinng that my
old wooden glider has a rough-air limiting airspeed of 80 knots. The turbulence was still not
too bad, despite the almost continual lift and I
kept the airspeed fairly stable at about 65
knots, although the ASI was flu ctuating a bit.
I still didn't lose much height and occasional
burs ts of lift would negate much of my height
loss, so I decided to try a prolonged side-s lip.
I straightened and stabilized at 60 knots, then
put on a fairly steep left bank and a lot of right
rudder. The glider s lipped a lright, but I had
trouble controlling the airspeed.
I hadn't carried out a s ustained side-slip previously in the Boomerang (what glider pilot
wants to lose height at thousands of feet per
minute?) - so I was monitoring the speed and
altitude very carefully.
At 70 knots, which it reached very quickly , a
pronounced buffeting started, which I could
damp-out by reducing the airspeed but at anything below 60 knots, my s ink-rate wasn't very
high. Furthermore, at much below 60 knots, it
was very easy to suddenly lose all feel of the
glider as if it was fully stalled. Centring the
controls and levelling the wings quickly cured
that and I set-up the slip again. This happened
a couple of Limes.
I flew in long upwind and downwind beats of
about a mile.
(Years ago, I had Ingo Renner give me a specific
lesson in side-slipping, in a Bocian, in case I
ever needed the technique - and I'm very glad
that I did.)
In this way, I gradually lost height to 3000 ft,
all in the vicinity of the airfield. I still had time
to keep an eye on the front , and I estimated it
had moved a bout ten miles in about twenty
minutes. I had a lso noticed the Auster take off
without a tow, do a big circuit and another of
its very long approaches, landing still into the
north. 'Ah', I thought, 'they have spotted the
front but the wind hasn 't changed yet.'
I could see no other gliders in the a ir, but several on the ground.
At 3000 ft, from a point a li ttle to the northwest of the northern end of the strip, I levelled
out and completed one more fairly steep, slipping t urn under full brakes and then decided to
set up a normal left-hand circuit for the northerly runway and see how the conditions were. I
was s till experiencing a lot of minor lift and not
much sink.
I flew on a very long downwind leg to a point
about 400 ft past the threshold, turned
crosswind and onto final, at about 1000 ft.
From here, with my full brake technique, I
knew I could get in safely with a fast, steep
approach, which would be well s uited to the
high wind conditions.
During the downwind leg, I had been trying to
find the windsock and cou ldn't. I had stopped
monitoring the approach of the front, which I
thought was still miles away.
As I turned on to final , I s uddenly saw it - or
the great dus t cloud heralding its arrival coming from the south-west, with me h eading
north! In other words, I had a forty-fi ve degree
tail-wind component.
�Aviation Safety Digest
Aviation Safety Digest
135
The strip runs a long the western boundary of a
large paddock. Just outside this boundary, to
my lefL, was the home paddock with the homestead , a very large dam, and three or four farm
buildings - as well as an assortment of disused
farm machinery, the clubhouse, and three
hangers.
I couldn't land there, so I abandoned thaL circuit and immediately turned on to a new
downwind leg to enable me to land into wind.
This took me diagonally across the paddocks, in
a norLh-casterly direction ahead of or with, the
front. Only for a very brief period though,
because I was now in the thick of the highspecd air mass.
My airspeed was still 60 knots, and my speed
over t he ground was enormous - my spellbound wi Fe, Margaret , said I went by like a
whiplas h. I co uld see t he northern boundary
fe nce but only with difficulty , because of the
dust. I turned into wind, monitoring my airspeed carefully because I am incl ined to pick up
speed in final t urns. When I straightened up, by
then only about 150 rt high, I was d iagonally
over the fence, alt hough I couldn't sec it
d irectly below . My airspeed was 65 knots .
Then a second or two later, Lo my g reat concern, the fence appeared below and Lo my right,
slowly creeping ahead of me as I was now fl ying backwards and descending onto Lhc fence.
The wind musL have been over 80 knots and my
height was t hen well under 100 fL, perhaps only
50 n.
As l was still flying with full brakes, I closed
t hem and lowered the nose. To my r elief, the
glider picked-up speed and Lhe fence slid convincingly behind me.
Insti nct Lhen took over, as reason had descrLed
me, and I opened the brakes again. I had been
flying fast, under nose-down t rim , but when I
immediately tried to raise t h e nose, t here was
no response. The glider s truck the ground in a
fifteen-degree nose-down attitude - w ith an
enormous bang.
l was badly winded by t he h arness, and my
head struck the canopy relatively lightly. This
comb ined with the canopy s pringing forward on
impact, caused it to be knocked-off its hinges,
fortunate ly w ithOHL damage. My hat and s pectacles flew off.
I was fu lly conscious and retained full control.
The ground run was very short and the wings
remained level but at quite a low speed, the
gli der gave a great swing to the left, as if Lo
ground-loop. I immediately applied full right
rudder and t he g lider sw ung hack on course
before stopping. I somehow don't fee l that my
control input helped much, and I decided that I
had run t hrough patches of turbulence in the
ai r mass. My son, who was running to help and
was the n only a few feet away, formed identical impressions.
135
I was so badly winded and bruised I could only
breathe with difficulty, and had to be lifted
from the glider.
My first reaction was how light the wind was,
but the people on the ground didn't think so.
I was surprised at the extent of the soreness
and bruising around my entire rib cage, front
and rear. My harness is a good one with a
broad abdominal band , a nd the main webbing
was replaced at the last C of A inspection , only
a few months ago.
The damage to the glider was relatively light
and was confined mainly to the fibreglass fairing from abou.t two feet behind the nose, back
to the wheel, and there was some damage to the
wheel mounting brackets and axle.
I concluded that I had n't pulled the lap-strap
down tightly enough before tightening the
shoulder straps, as I have previously observed
that it is difficu lt to position the lap-strap properly over my comfortable middle-aged belly .
It is difficult to reach conclusions as to what
else I could have done having once cjecided on
my cour se of action. Certain ly I was badly al
fault in not r ecognizing the fro nt earlier and
getting straight down.
Altogether, I t reated the early part of the situation too casually, and having decided to lose
height and land, I hadn't allowed for the time it
took to escape from the cu-nim, altogether
about twenty minutes. Even without this delay ,
my t ime allowance was too marginal.
I don't regret not staying up - to me the
unknown possibi lities already mentioned were
too numerous and the potential risk too high.
While I was sore and bruised and my glider
damaged , I did manage to land it right into the
face of a ver y strong front, and the impo rtant
decision was to land into wind . The opening of
the brakes at the last moment was wrong. If
Lhey were closed , there was still the pos ibilily
of control difficulty in the flare, but the probability of a better landing was high.
In retrospect I th ink I may have been closer to
t he cloud-base - or at least to its area of influence - t h an appeared al the t ime.
While I could see u pwind quite clearly for severa l miles and the downwind view was excellent, I think t he cloud base was wedge-shaped ,
lowering as the front approached. The grip of
the cu-nim perservered , however, for at least
two thousand feet from the height at which I
commenced my descent , and I didn 't fl y th rough
any perceptible sink down to 1000 ft agl from where I was too busy Lo continue monitoring my Variometer.
And to pilots gener ally , if you feel that yo u
may indulge in such antics, I advise you not to
have your wife watching' 0
Any landing that
you walk away
from
forced landing that is . ..
HE PILOT OF Lhe Cessna 150 was to fly
from Cooroy in Queensland Lo Noosa to pick
_ up a passenger and then on to Roma.
He dipped the tanks at Cooroy and again aL
Noosa wher e he obtained a reading of 10 gallons in the right tank and 11 gallons in the lefL.
The pilot a lw ays dipped the tanks and flew on
'time'. He never trusted the fuel gauges.
He had a total of 650 hours of which 450 were
on t he Cl 50. He had flown nearly 90 hours in
t he previous 90 days of which 50 were on type.
He held constant-speed, retractable, formation
and aerobatic endorsements.
He picked up the passenger at Noosa and they
departed for Roma at about 0900 hours.
The aircraft was established in Lhe cruise at
4000 reet and the mixture was leaned with refe rence to the EGT. The p ilot planned on a fuel
cons ump tion of five gallons per hour - on the
basis of previous experience where he usuall y
obtained 4. 7 gallons an hour at that altitude.
As the aircraft approached Roma the passenger
noticed that the fuel gauges were getting close
to empty. The pilot agreed but thought there
must be something wrong with t he gauges as he
h ad dipped the tanks and should have had
enough fuel for over four hours flying.
About five miles east of Roma the engine
stopped completely and without warning. The
pilot pushed the mixture to full rich and
pumped the throttle. The engine spluttered but
no more.
He continued towards the airfield as ther e was
a chance he could make the cross runway but
he also started looking for a paddock. He could
see there was a fairly strong headwind and
decided not to continue towards the airfield as
t here were houses in that direction.
He considered the highway but there was a lot
of t raffic. The football field looked wet and the
goalposts looked too high to clear. There were
several roads but too many power lines. He
selected a paddock but on getting close, it
looked very wet so he rejected it.
He then spotted another newly-constructed road
in a sub-division and was by then committed to
getting down pretty quickly. He noticed there
was a truck at the approach end which left him
little room. He also realised he was landing
downwind but at this stage, had no choice.
On short final he selected flap and had to avoid
the truck and land as close to it as he could.
Indicated airspeed on landing was 50 knots but
the groundspeed was obviously higher. He
realised the road was newly-surfaced and he
braked heavily.
About 145 metres from touchdown the road
veered 65 degrees to the right. The pilot could
see he was running out of room. There were
poles ahead and the area to the right of the
larger pole looked wet and had some stumps in
it. He was worried about overturning. He
applied left rudder and steered between two
poles.
The passenger was looking at the pole coming
towards him and observed, 'If you don't move
over, I'm going to wear this power pole.'
The pilot replied, 'Look mate. I'm doing my best
to move over!'
The pilot aimed between the large pole, a
shorter pole and the staywires - with the
intention of taking the impact on the wing
roots. The aircraft was still travelling at about
50 knots.
Then it was bang! Stop! The a ircraft stopped in
a distance of about one metre.
The passenger was caught and could not release
his seat belt. He appeared to be in pain. The
pilot released his own and the passenger's belts
and they exited the aircraft.
There was no fire and no serious injury .
There was no usable fuel remaining in the tanks.
The forecast w ind at 4000 feet was southwester ly at 15-20 knots. The pilot had not
checked the forecast and had planned for a T AS
(and presumably a groundspeed) of 90 knots
with a fuel comsumption of five gallons per
hour. With this wind, the ground speed was 7 4
knots (a 16 knot headwind) and the total fuel
required for the trip was 19 gallons - with no
reserves. The aircraft had 21 gallons of which
2.5 were unusable.
NINETEEN REQUIRED AND EIGHTEEN POINT
FIVE AVAILABLE - unfortunate arithmetic!
(Remember the WWII song, 'Coming in on a
wing and a prayer'?)
�Aviation SafetyDigest
Aviation Safety Digest
135
135
Patterns can be interpreted. A difference in
direction or speed as indicated by two socks
can show a transient change or the influence of
mechanical interference such as trees or buildings. It is not unusual during the passage of a
front to have windsocks at either end of the
runway showing wind directions directly
opposed - and willy-willies can produce all
sorts of interesting effects.
What is the significance of the windsock?
All takeoffs and landings should be as intowind as possible for the following reasons:
• shorter ground-roll
• lower groundspeed on liftoff and touchdown
• better aerodynamic control at a lower
groundspeed
• steeper climb and approach angle for obstacle
clearance
• in the case of engine failure the shortest
ground-roll and lowest ground speed
• the greatest remaining runway for aborted
takeoff or go-around
• the least wear and tear on the undercarriage
and brakes.
Remember that a calm day is a disadvantage as
far as takeoff and landing performance are
concerned.
The humble
windsock
Therem lies a tail.
N THE NINTH decade of the twentieth century, a transport aircraft weighing close to
half a million pounds is still vulnerable to a
puff of wind.
And in the ninth decade of t.tte twentieth cen·
tury, the most important clue to the behaviour
of the wind is the humble windsock.
Every licensed aerodrome has one. Every ALA
has to have a wind indicator - also generally a
windsock.
And the windsock - despite its primitive
appearance - is a. very valuable, valid and
informative aid.
But do we glean every ounce of information out
of it?
What can it tell us. The direction of the wind
certainly. The strength of the wind, certainly
The consistency of the direction of the wind ~
and the consistency of the strength of the wifl,d..
In relation to other wind cues -or in those c~
where there are two or more socks we can a®·
ally read the wind pattern around the airfie16
and especially around the threshold. We can
also read a trend by comparing the upwind ~
with the downwind sock?
There's more to it than meets the eye.
Let's start at the beginning.
Firstly direction. This can be read directly from
the sock and relative to the runway. The velocity can then be factored to determine the
headwind and the crosswind components. The
consistency of the direction or conversely, its
inconsistency can be observed.
Next strength. The strength or speed of the
wind can be read from the angle of the sock
from the vertical or the horizontal. If the sock
is hanging vertically there is no wind (or someone has filled the sock with lead). If the sock iS
absolutely horizontal the wind speed is 30 knots
or more. If the sock is half way between vertical and horizontal the speed is approximately
15 knots. If the angle is varying the speed is
varying or there is a vertical gust component
affecting the sock.
I
There is much to be learnt from this accident
and not just in regard to fuel p lanning. The
pilot's handling of the forced landing, his
decision to forget stretching the glide to Roma,
his avoidance of the power lines and his cool
manoeuvring between the poles, are all positive
clues as to how, having been caught, the pilot
can in most cases recover the situation Lo the
extent of avoiding serious injury. I think he
coped pretty well.
BUT HE SHOULDN'T HAVE BEEN IN THAT
SITUATION IN THE FIRST PLACE. Where have
I heard that before? 0
11
I
Half out and all across
All out and half across
Now that all-over fields are rare we are left
with the inevitable - the strip never points
exactly into wind - there is always an element
of crosswind.
Many GA aircraft seem to have a crosswind
limit in the region of 15 knots. Tailwheelers are
generally lower, perhaps 10-12 knots and some
trikes can be as high as 25 knots. But as a general rule, 15 knots is a good figure to watch out
for.
The sock at a vertical angle of 45 degrees indicates a wind speed of 15 knots so if it is all
across the runway, then the aircraft's limit is
close. The sock at a directional angle of 30
degrees to the runway indicates that half the
wind speed will be felt as crosswind so that if
the sock is horizontal (indicating about 30
knots) the 15 knot crosswind is again reached.
Similarly if the sock is 45 degrees to the runway direction and almost horizontal, the
crosswind is again close to 15 knots.
As a guide, remember -
ALL OUT AND HALF
ACROSS or
HALF OUT AND ALL
ACROSS
Then WATCH OUT - you are close to or have
just exceeded the aircraft's demonstrated
crosswind limit.
�_______Aviation
s. SafetyDigest
�
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0
'
0
ASD 134
SPRING 1987
0
LANDING
�Av1at1on Safety Digest is prepared by the
Department of Transport and Communications
and is published by the Australtan Government
Publishing Service. It is distributed to Aus
tralian licence holders (except student pilots).
registered aircraft owners and certain other
persons and organisations having an
operational interest in safety within the Aus·
tra/1an civil aviation envlfonment.
Contents
4
Av1at1on Safety Digest is also available on
Spring is in the air
Flying has its ups and downs
- especially in the Spring.
D1stnbutees who expenence delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Department of Transport and Communicat10ns
P 0 . Box 1986, Carlton South. Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
6
Afterthoughts?
A safe flight is nicely finished off by a post-flight
inspection.
7
The power of nature
Thunderstorms deserve respect
- and a wide berth.
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. lnqu;,ies and notifications
of change of address should be directed lo.
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T 2601,
AUSTRALIA
Telephone (062) 95 4411 . Telex AA62013
8
Subscriptions may also be lodged at
Commonwealth Government Bookshops m
the capital cities.
13
Arrival -
the best part of the journey?
Wha l does it take to make every landing a safe landing?
Unless otherwise noted. articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish onl'f those items which are assessed
as being constructive towards flight safety.
Reader contributions and correspondence
shoufd be addressed to:
14
How do I land thee? Let me count the
ways
Choosing the best approach
Attitude is the vital ingredient.
15
A flare for landing
A new visual cue for initiating the flare.
Department of Transport and Communications
G.P.O. Box 367,
Canberra, A. C. T. 2601 , AUSTRALIA
©Commonwealth of Australia 1986
ISSN 0045-1207
R85/979(7) Cat. No. 86 0310 3
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S.W. 2142,
AUSTRALIA
Most of us have just been through our leanest period of
aviating for the year and we may be more than a little rusty. Our
familiarity with the aircraft and its systems, with procedures and
checks is at its lowest ebb. Our handling techniques - the visual judgments and control inputs - are less automatic and may
need greater conscious effort.
In the southern States. Spring weather can be changeable , with
frontal passages and gusty winds. The weather can turn fairly
quickly from sunny to heavy downpours. The rmal activity is
increasing and there can be significant mechanical turbulence.
Spring can ge a time of crosswinds. windshear and perhaps wet
runways.
As we trundle the faithful craft ou t of the hangar, it is worth
reflecting on these conditions and our limitations and making
sure we are as prepared as the aircraft for the coming flights.
A major portion of this issue is devoted to the subject of the
approach and landing. Landing an aircraft safely, consistently
and well is the greatest challenge that we have to face. That is
not to say that all landings are poor.
Covers
Front. When the going gets tough ... the
tough get going. A major element in
landing accidents is a late decision to go
around. He who floats and flies away,
lives to float another day?
Photograph by Brenton Hollitt
Pen tax SP 1OOO - Kodacolor
Back. In every walk of life. we have to fit
in, to accommodate each other - there
must be some give-and-take and there is
usually some unwritten code of behaviour.
Aviation is no different. 'Do the right
thing' unto others and they will 'do the
right thing' unto you. ['Do the right thing'
unto the aeroplane also.]
My thanks to the N.S.W. State Pollution
Control Comm1ss1on for permission to use
material from their highly successful
. campaign.
The vast majority of the thousands of Jandings carried out each
year are safe and those that result in an accident or incident
usually do not result in death or injury. Nevertheless. there are a
significant number of landing accidents and incidents (more
than during all other phases of flight com bined) and most of
them are caused by you and me (the pilots of the aircraft) and
most of them are avoidable - if we pay attention to three aspects:
decisions,
18
The gentle touch
Let the aircraft land itself.
19
When everything turns to worms
Escape clauses -
always check them.
The Editor,
Aviation Safety Digest
T'S SPRING at last. The birds are singing and it's time for us
to get back into the air after the winter lay-off.
It may be a wise precaution to have a dual ride wi th the CFI
before we let ourselves loose on the world . Some study would
be good value and so wou ld some 'air conditioning'.
There is more than one technique for landing an aircraft.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Department. The articles are mtended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazardous
situations.
Editorial
20
•
application,
•
technique.
Some of you may have seen the new video, The Gentle Touch,
produced by the Department. It has been circulated to all flying
training organisations in Australia free of charge and may be
shown and copied without restriction . I urge you to see it and
please let me know what you think of it. It is designed to pro·
mote discussion - as are the articles in this issue. Please talk
about them with your colleagues and only experiment when you
have an instructor with you and when you have previously
briefed what you are going to try.
Seat belt, belt, belt, belt, belt, belt, belt
Editor:
Editorial Assistant:
Graphic Design:
I hear you knocki ng but you can't come in.
Photographs:
22
Airflow
P4
p 7. 8
DAVID ROBSON
Editor
p 12, 13
p 20
David Robson
Karen Hutchison
Lesley Gordon
Mike Cleaver
BAS/
Michael Jensen
Steve Small
The readers' column.
Diagrams:
Soussanith Nokham
�Aviation SafetyDigest
134
0
Spring is in
the air
Garry Leach is a former GA pilot who also had some gliding and hang-gliding experience before becoming an
ultralight aircraft pilot. He has logged about 350 flying hours.
His main flying interests include cross-country trips and
trying to catch thermals. One cross-country trip included
crossing Bass Strait both ways by ultralight.
Garry has been the AUF Vice-Presiden! for two years and
is an active member of the AUF committee for proposed
airworthiness standards. He would like to see the development of ultralight competitions.
CAN ONLY touch briefly on t he topics in t his
shm·t article. If you wish to have a better
• understandi ng of t his area, the n you should
read some of the relevant books. One book on
t hese s ubjects, which I have found to be compre'he nsive a nd reasonably easy to follow , is
'Micro-meteorology' by Dennis Pagen.
It is like ly t hat you . h a ve not been fly ing in the
past t hree or fou r mont hs, due to w int ry
weathe r . It is quite possible that your last
flight was in t he ideal conditions of an Autumn
high-pressure system. This article is intended _to
remind you t h at spring weather is u su ally qmte
different from a ut umn weather in sout hern
Australia.
Pla nts like to grow in spring because they get
,plenty of what t hey need for growing - t~ain
and sun. So spr ing is characterised by rapidly
a lternating periods of s un and _rain (often both
in the same day) and fast-moving pressm·e systems and fronts.
A certain amount of t urbulence could mean a
slight bump in an airliner. However, the same
amount could h ave a quite severe effect on an
ultralight , due to its very low size, mass and
wing-loading. The effect on GA air cr a ft a lso
¥aries with wing-loading and would l>e s omewhere between the above two extremes. The
danger is not so much the likelihood of structur al damage from the thrashing of t he air , but
r ather t he loss of control authority. Loss of control at altitude could be recoverable or it could
lead to manoeuvres outside the aircraft's envelope. Unfortunately , t here have been a number
of reported accidents, pa rticularly ove rseas,
from stru ctura l dama ge due to loss of control.
Structu ral damage should not occur if the aircraft is flown below its t urbulen ce penetration
speed. If t his speed is not provided by t he
manufacturer , it can be calculated as the stall
s peed mult iplied by t he squa re root of t he
aircraft's design load. Since t he limit load for
u ltralight aircr a ft is supposed to be + 4 g and
- 2 g, t he n t he manoeuvring speed should be
stall speed t imes two for normal flight and less
for down ward gusts. If properly designed , const ructed a nd maintained, your structm-e should
not fail if you keep w it hin these speeds,
because t he w ing stalls before becoming overloaded. (It is essential that the accuracy of your
ASI be k now n when you operate close to your
aircraft's limits.) However, the factor for negative loads is qu ite low a nd t his is w here some
a ircra ft h ave failed - t h ere have been two
Australian examp les in t he past 15 mon ths. The
other a spect, t hough, is w hat degree of control
you have after t h e aircra ft has stalled due to
excessive 'g' loading.
Fly ing in t urbulence is an acquired taste, like
eating blue vein cheese. Because of t his , some
pilots never fly in t urbulence. The ability to
operate in t urbulence depends on t he severity
of t he t urbulen ce, t he s kill of t he p ilot and t he
behaviour of t he a ircra ft (rea ction to tur bulence a nd cont r ollability), more or less in t hat
order (for lightly loaded ult r alight aircraft).
Pilot skills need to be developed gradually, by
starting w it h mild tu rbulence and slowly progressing to more severe condit ions.
0
0
0
0
There are four main types of turbulence mechanical, s hear , thermal and wingtip vortices. In our a llowed airspace (below 500 feet
agl), we can expect to find all of these types of
turbu lence, at various times.
Wingtip vortices a re more likely to be found
near airrields, particularly j oint-use GA/ UL
fields . The vortex from an aircraft of equal
wing-loa ding is quite noticeable; from a heavier
air craft it can be uncontrolla ble. Even a Cessna
150 produces vortices which may severely
affect ult ralight aircraft. Since w ingtip vortices
flow rearward a nd downward from a n a ircraft,
avoid flying below a nd behind anot her aircr aft .
Take off shorter t han a pr eceding aircraft a nd
land further down the runway than a preceding
air craft. Better still , wait for a couple of minutes - and stay well clear of helicopters.
Shear turbulence often occurs at the meeting of
cold and warm air masses. Air masses with d ifferent temperatures tend to move with differ ent v elocities, due to their different origins or
response to a pressure system. A cold or warm
front , a sea breeze or simply an inversion w ill
often present s hear t urbulence. Shear turbulence can occur at the top of a 'pool' of cooler
air t hat fills a v alley in t he morning or evening,
when the ambient w ind blows over the top of
the v alley from the plains or hills surrounding
the v alley . The shear may be either at a horizontal or vertical surface.
Mechanical t urbulence res ults from the wind
encount eri ng an object such as a building , t ree
or hill. The resulting dis turbance to t he a irflow
is felt as turbulence. The amount of t urbulence
depends on the velocity of the wind and t he
s ize of the object. If t here a re many objects,
t hen t he airflow is disturbed in a much more
complex way and resu lts in even mor e turbulence. If you wer e to fly close to an object of
the size of a VW micro-bus in a 15-knot wind ,
you wou ld expect to find the t urbulence quite
noticeable, a nd it may extend for a considerable
dist ance downwind, depending on many
meteorological factors.
The airflow on the lee s ide of a hill or ridge
will most likely include a downdr a ft , w hich can
be q uite s trong in a moder ate w ind a s well as
being quite turbulent, and may even include
occas ional reve rsals of the s u rface wind
di rection.
Large obj ects, such as a row of tall t rees or
buildi ngs can cause a wind 'sha dow' as well as
mech anica l t urbulence. The wind sha dow for ms
a wedge wit h its t riangula r profile sloping from
the top of t he obstruction out to t he ground.
Wit hin t his wedge , t he wind s peed can be
virt u ally 2ero. However, the tu rbulence is more
h azar dous th an the calm ai r is beneficial, so
su ch obs tructions should be t reated w it h
res pect.
A wind gradient means that there is a graded
change, which is often sharp and pronounced
(almost always an increase) in the wind velocity with height. The basic reason for this
situation is friction of the air with the earth's
surface. A wind gradient is usually more severe
during stable conditions. Unstable conditions
(usually caused by thermal activity) result in
ver tical a ir movement which mixes the air and
evens-out the velocity at heights close to the
ground. The main times in which wind gradients can affect us are during a descent or turn
within 100 feet of the ground (although it can
be a problem even higher).
Turns in a wind gradient may also cause difficulty because the wingtips a re in air moving at
different speeds, so a ileron response w ill be different - a nd in an ultraligh t t he wind velocity
represents a significant proportion of cruise airs peed. If you are t urning d own wind t he lower
wing w ill have mor e a irspeed (hence mor e lift)
s o bank tends to decrease (or more control is
needed): if you are turning into wind the situation is the opposite and bank tends to increase
- if the lower wing st a lls you are in serious
t rouble, so either don't tu rn low down in strong
w inds, or e lse fly faster near t he ground.
T hermals a re rising parcels of ai r which arc
warmer tha n t he surrou nding a ir . Typically, t he
air has been warmed by contact with a patch of
ground which, due to its nature or colour
(ploughed field, burnt gr ass, asphalt, rocks,
water), has been a bsorbing heat from the sun at
a faster rate than n ear by areas.
The airflows in a t he rma l a rc not usually even ,
s ince s ome par ts arc warmer than others and
some other p arts are cooled by mixing w it h
n on-rising a ir. In a ddition, there is often s t rong
s inking a ir near by, in part mov ing to replace
t he rising a ir of the t herma l. This ' mixture' of
fast-ris ing, s low-rising a nd s inking a ir can push
an ultralight aircraf t in a ll di rections.
A parcel of ai r which is still s itting on t he
ground, becoming warmer by the minute, can be
disturbed by a passing vehicle or low-fl ying aircr aft or, event ua lly, by its ow n buoya ncy. The
release of the ther mal usually triggers an
inflow of air , from a ll directions, to take its
place. This can create a te mporary tailwind . It
could also create a w hirlwind , wh ich could
cause control dif ficulties, a nd may be less
noticeable in spring than the typ ical 'dust-dev il '
of s ummer .
Another weathe r-related factor wh ich can cause
difficu lties close to the ground is a microburst.
A microbu rst is triggered by an increase in
moisture (s uch as ra in fallin g), wh ich cools the
air and causes it to s ink , sometimes at s peeds of
thousands of feet pe r minute. The sinking ai r
can cause under-shoot ing, a hea vy landing or
worse. As t he downd ra ft a pp roaches the
ground, it spreads outwards in all directions,
often raising dust and prod ucing increasing
�Aviation Safety Digest
134
Aviation Safety Digest
134
headwinds, crosswinds or tailwinds, so a n
expanding r ing of dust is to be avoided. The
difference in speeds of the w ind at either side
of a microburst (i.e. t he headwind on one side
and the tailw ind on the other side) can be in
excess of 50 knots. Fortunately, microbursts do
not last for long (five t o 15 minutes) and are
quite localised (one to three km diameter). One
indication of t h e possibility of a microburst is
'virga', t he mid-level rain which s tops before
hitting t he groun d - it a ppears as a veil h anging below the cloud.
If thunderstorms or heavy shower s a re in the
area, t hey may affect the surface wind for a
distance of tens of kilometres, and ult r alights
(and GA pilots) should be alert for s udden
changes, or should a void fly ing in t hese condi tions a ltogether .
Flying in ra in is not recommended , due to t he
marked reduction in visibility and t he changed
fl ying characteris tics of wet w ings. In p ar ticular the s ta ll s peed is increased s ign ifi cant ly and
t he stall characteristics may be very different.
Also, t he ra indrops play havoc w ith wooden
propellers.
If you are taking off through a w ind-gradient
your airspeed and rate of climb w ill incr ease
quickly as you climb through it. The reverse
happ ens on descending into the s lower mov ing
a ir on la nding, caus ing a loss of airspeed and an
appa rent unde rs hoot. If you do not car r y
enough excess speed to over come this, the loss
Afterthoughts?
A habit that I acquired from an old hand has that touch of
aeronautical wisdom that may have been Jost in recent
times. The Airlines do it and so do the Armed Services but
their good habits and practices aren't always filtering
through to we pilots of wee aeroplanes.
HE BENEFITS of a thorough pre-flight are
obvious, a lthough I am embarrassed to say
that s ome pilots are only cursory examiner s
and some pilots have been known to skip a preflight altogether. But enough of that hobby horse.
The tip I have to pass on is the value of a p ostflight inspection. The commercial operators use
trained ground staff to ins pect the aircraft
afte r each flight. We have to do our own .
The benefits are fairly clear-cut:
• you can detect an unserviceability earlier and
get it fixed before your planned departure or
the next scheduled sortie, (I'm sure that's
why the Airlines do it - they have tight
schedules. The Services of course need to
know that the aircraft is r eady to go at an y
time.)
• you can warn the next pilot that s omething is
a miss ,
• you can pick a trend towards a possible failure, earlier.
of a irspeed may even cause a stall , despite a
low nose attitude. This is why, in an ultralight ,
you add a n additional Y3 of the wind s peed to
Lhe normal nil-wind approach sp eed of 1 Yz
Limes Lhe stalling s peed . As you descend
t hrough t he w ind gradient you will need to
lower the nose to maintain speed, and poss ibly
add power Lo s low your descent rate an d help
you a ccele rate. Because your ground speed is
higher now, the landing roll will proba bly be
longer than you exp ected .
In light winds a t emporary ta ilwind w ill als o
produce problems on approach a nd la nding. The
ground speed will be high , giving a false
impression that the airspeed a lso is high , and
t he approach path w ill be flatter t han usual. As
well as increasing th e ground run t here is a risk
of over shooting your intended touch down point,
and a loss of directional control as you run out
of airspeed while still rolling. It may be safer to
go around rather th an persever e with a landing
which is going wrong in these circums ta nces.
Remember the wind may be different w here
you arc landing from that at the windsock, 200
metres a way.
0
What I have described her e is noL something
that onl y happens to th e other guy. I h ave
either exp erienced these phenomena or have
been flying w ith other pilots wh en they experien ced t hem. Remember to kee p your upper limit
of turbulence well below you r level of
controlla bility and you w ill enjoy fl ying for
many s prings Lo come D
After climbing to 8500 ft, the p ilot report ed
that he could see t he lights of t he mines to the
south of Blackwater. He tracked to that ar ea,
and subsequently to Blackwater town, where he
set himself up in a racetrack p atte rn at 2400 ft
AMSL between 35 and 40 DME from Emerald
on the Blackwater-Emerald t rack. There were
storms to t he north and wes t of the area. After
some time wit h out success at arranging the
lights, t h e pilot asked Flight Service to ring his
company at Emerald and ask them to arrange
for lights to be displayed. The pilot reported
tha t he also ch an ged t he engine speed over the
town in order to stir someone into deploying
the lights.
()
o
The power of
nature
What to look for
If you do your pre-flight with a rag in your
hand and clean any smears, drips or pools of
oil , grease, hydraulic fluid or fuel, then the
important part of the pos t-flight inspection is to
look for le aks. Any fresh smea rs or runs are
immediately evident, as is any damage from
stones, grav el, hail or whatever.
The combination of a pre-flight and post-flight
inspection inunediately shows any dete rioration.
Seeing both the 'before' and the 'after' gives an
immediate comparison or trend, like the ads on
TV. Any suspect leaks can be confirmed or
watched. Any nicks in the prop can be r elieved
be fore the next flight and wit hout the urgency
of a late-discovered discrepancy in the
pre-flight.
Someone once told me that there was more energy in a
large thunderstorm than there was in a nuclear explosion.
Now I believe her.
Method
My pos t-flight checklis t is simple. I double
check that the ignition and the Master switches
are off and I do a slow walk around concentrating on the underside of the aircraft and looking
for leaks, smears, drips, stone damage, chips to
the prop, tyre scuffs and loose 'bits'.
Then I lock the controls and tic the aircraft down.
As an afterthought, it has saved me mu ch
stress and avoided ma ny delays. It has repaid
the time it ta kes, many times over D
0
0
HE PILOT was conducting a charter flight,
carry ing freight from Bris ba ne to Emerald.
_ The flight was conducted with numerous
t hunder storms around. Although the pla nned
cruise altitude was 4500 ft , Lhe pilot h ad
climbed to 8500 ft approaching Emerald in
order to r ema in clear of cloud a nd main tain visual contact wit h t he storm cells. During the
fli ght, he observed t hat Th angool a nd Rockha mpt on had s torms in t he a rea and that Blackwater was clear , although ther e were s torms
around . There were also s torms in the Emerald
area.
He conducted a DME arriva l into Emer ald until
forced to a bandon the approach at 10 DME. The
extent of the line of sto rms running north/
south through t hat area was such th at he could
not diver t to Clermon t or make a ny other
attempts to pos ition himself on their wes tern
side. The pilot initiated a climb to 85 00 rt a nd
divert ed to Black water a t 0310 hou rs local
time. A s hort time later, Brisba ne Fligh t Service
as ked t he pilot if he had arra nged for lights at
Blackwater, w hich he affir med .
Dur ing his secon d racetrack pattern when
approaching 35 DME, the pilot entered cloud
for the fir st t ime. Shortl y a fter enterin g t he
cloud, severe turbu lence was encountered, his
headset was thrown off a nd his hand accidentally knocked the gear down .
The pilot reported that he made no fur ther control inputs and found himse~f a bout ten seconds
la ter a ble to v acate the aircraft which was 1w 'w
on the ground.
When he de termined t hat the a ircraft would not
burn he retu rned to it in orde r to activate t he
ELB. All the li ghts and radios ca me on when
the master switch was t urned on and he was
a ble to check t ha t the ELB was operating.
Shortly after this he noticed vehicles moving
past not too far away, so he turned ever ything
off an d went to t he road to fl ag down a car.
The driver was a woma n going to t he airport to
deploy t he lights for him. He a s ked for the
nearest p hone so he could notify his company .
Eviden ce indicates t hat an aircraft had flown
a round t he South Black water mine area at
a bout 0320 at about 400 ft agl. Around 0330,
an aircraft flew low ov er the town on a number
of occasions and some witnesses reported that
the engines were varying in speed. Ligh t rain
was falling over most of t h e ar ea. Some a reas
had wind gusts a nd heavy rain. No witnesses
saw the aircraft near t he a irpor t, but it appears
tha t there may have been a storm cell in the
vicinity of t he airport at t he time. No s ignifican t w ind or ra in was observed at t he airport
for a consider able time after t he accident.
The aircraft s truck t he low s crub hea ding SSE
with 40 degrees of bank to t he r ight a nd a sh allow descent angle, about 250 metres to the east
of t he runway. After t he righ t w ingtip contacted t he ground, the aircraft rota ted clockw ise so that its nose was scraping t he soft
ground and the ta il was in the air. The fuselage
was moving s ideways as it contacted the
ground. The ma in gea r legs were broken off and
the aircraft s lid to a ha lt w hile moving backwards. The a ircraft t ravelled 150 metres from
t he first ground strike to r est D
�Aviation Safety Digest
134
Arrival - the
best part of the
journey?
Aviation Safety Digest
134
n
Normal checks were carried out on downwind
and he turned Base and Final normally. He had
decided to use an approach speed of 70-75
knots instead of his usual 65 knots due to the
AUW of the aircraft and the crosswind conditions and possible t urbulence.
The aircraft was seen to fly through the
centreline and S-turned to regain the correct
approach path. It first touched down about half
way into the field and then bounced several times.
The pilot thought he could still land successfully but then realised that the end of the runway was getting quite close. He decided to go
around and applied full power.
The pilot said that he deliberately left full flap
selected to a void any sink.
HE LANDING phase can be a problem area
for many pilots. Statistics show that a s ig- nificant percentage of accidents occur during the approach and landing· and that a major
proportion of these are avoidable - that is to
say they are our fault, the pilot's fault faults in decision-making, in judgment, in procedures, in checks or in contr ol of Lhe a ircraft.
Let's keep it in perspective, though. There are
thousands of landings each year and the vast
majority of these are safely completed. Having
said that, we s till should try to reduce the accidents that do occur - particularly as t hey
appea r to be easily avoided.
To ensure t hat the thrust of the Depar tment's
safety promotion activities was in the right
direction, the Bureau of Air Safety Investigation was asked to examine the overall accident statistics for a ten-year period. This study
confirmed that t he landing phase wa:s a s ignificant problem area. The Bureau then looked
more closely at a one-year period to see if this
could pin down the cau se of landing difficulties.
This study gave us a close-up view of the problems and the contributory factors but still did
not answer t he real question - why did the
accident occur? What really caused t he accident? Why was the a pproach speed excessive?
Why did the pilot, w ho was presumably t a ught
correctly, mis handle the bounced landing? Why
didn't h e go around? Why did he misjudge the
flare? Why didn't he anticipate th e w indshear?
Why did he press on w hen a 8afe landing was
doubtful?
Why? Why? Why? Why? Why? Why? Why?
Let's look at a few typical landing accidents:
1. The aircraft flew from Port Macquarie to
Aeropelican near Newcastle. The p ilot j oined
' the circuit and examined t he windsocks. His
estimate was that the wind was from the southeast at 8-10 knots and s o he made a standard
right-hand circuit for runway 07.
He had not previously made a go-around from
after touch-down. The initial touch-down
wasn't dramatic and he thought it had only
bounced a foot or two. He could feel that the
aircraft was rocking fore and aft. Everything
happened so quickly .
3. The Grumman Tiger appeared to make a normal approach for runway 23 at Birdsville
except to some it appeared hot or high. Initial
touchdown was well into the strip, about halfway along.
Surface wind was 300°/ 10 kt -
all crosswind .
The aircraft just became airborne some 150
metres before the boundary fence and seemed
to hang in the air . The stall warning was
blaring. The p ilot turned the aircraft slightly
left to avoid some heavy steel cables that he
knew were at the end of the runway. The aircraft struck the boundary fence and skidded to
a halt. The pilot and passenger escaped unhurt.
The aircraft touched down in a fairly level at titude and bounced. The next touchdown
appeared level if not slightly nose low and the
aircraft bounced again. At this point an
observer called out in the Australian idiom that
something was amiss.
2. The student p ilot had been conducting practice forced landings in the local training area.
There was no fire nor injury.
During the overshoot from one of these
approaches, he noticed that the flap on his
Cessn a 152 would not retract beyond the twostages-down position.
He advised the flying club of the problem, discussed it with his instructor and returned for a
landing.
The pilot later explained his concern or preoccupation with the flaps and that he wanted
to land as soon as possible and to avoid a
go-around with the flaps stuck in this position.
He flew , what was in his own words, too tight a
circuit and had to S-turn on final to regain the
centreline. This was partly due to the distraction caused by an aircraft taxiing for takeoff.
The surface wind was 330°/ 10 kt - a 5-6 knot
crosswind. His approach speed was 70-75 knots.
The approach appeared to be a little steep but
the flare looked normal.
The aircraft bounced on touchdown but with
his mental attitude, the pilot was determined to
keep the aircraft on the ground and so he persevered with the landing.
0
From t he cockpit the bounce didn't seem all
that bad. It was when all the wheels were on
the ground and the pilot couldn't control the
aircraft t hat he became concerned.
From outside it appeared that the aircraft was
pushed onto the runway (back pressur e
released). The nosewheel struck the ground ,
bounced, struck the ground again and collapsed.
The aircraft left the runway at about 30-40
knots and overturned.
The aircraft impacted the runway in a markedly nose low attitude and skidded to a halt
resting on its mainwheels and nose.
4. The pilot of the Cessna 182 overflew the 610
metre long ALA and checked the windsock. He
assessed a crosswind of 10 knots.
As he turned Base he experienced moderate turbulence and decided to make his approach at 80
knots with 20 degrees of flap selected. He
crossed the threshold and closed the throttle.
The aircraft floated until finally touching down
half way along the strip at 68-70 knots. The
pilot started braking heavily but the aircr aft
didn't seem to be decelerating significantly. The
aircraft veered off the strip, bounced through
three drains and crossed a road.
To try to understand the steps or pitfalls
associated with landing an a ircraft safely, I
t ried to break down the approach and landing
into its functional elements. I concluded that
there were three primary elements involved:
• Decisions
-
what decisions, whether and
when.
• Application -
a combination of procedures,
checks and standards.
• Technique
the visual references used,
the control inputs made and
escape manoeuvres.
-
�Aviation Safety Digest
134
Aviation Safety Digest
134
Decision
The essential first step in any phase of flight is
the decision. At this point an accident can be
caused or avoided.
Some pilots didn 't actually make a conscious
decision but appeared to press on until something forced them to change their p la ns. This
often occurred too late for a safe a lternative to
be chosen .
Many pilots deferred the decision until the
probability of a safe alternative course of
action was seriously reduced.
Some pilots made a decision that was less than
optimum or not the safest or wisest option . The
decis ion-making process may seem to be second
nature but it is worth considering what is
involved.
Many of us pride ourselves on being able to
make a positive decision - a quick decision on
t he spur of the moment - an 'operational'
decision. We are captains of our aircraft and we
therefore make all the necessary decisions we don 't sh irk our responsibility. We make a
decision and get on with it.
But it isn 't a lways necessar y to make su ch a n
urgent decision. There is usually time to consider all the factors and options carefully and
to make a reasoned judgment - and t he n to
test the wisdom of t hat decis ion . If there
doesn 't appear to be s ufficient time we can
usually make time - by anticipating the need
for a decision , or by going ar ound for another
approach.
Certainly t her e are occasions wh en a decision
has to be made t hen and there a nd we do the
best we can . It is better to make a decision t han
to defe r until it is made for us, but better s till ,
we should use the time available to make a
quality decision - a wise decision.
The first s tep in the decision-ma king process is
t o gather information - to collect data t h at is
r elevant to the decision. In the case of the
approach and landing, it includes inform ation
relating to either the risk or the probability of
s uccess of t he landing - such as the runways
available, t he condition of the s urface, the
direction in relation to the wind, the s urface
wind , the slope , the temperature , the
approaches, the overruns, the retention of a
safe esq1.pe route and the lighting conditions.
It is obv ious ly important to ens ure that we
h ave gathered all the r elevant data or ot h erwise the decision may be invalidated - perh aps seriously.
The next step is to compare the data against
some form of yardstick. In the case of the landing there a rc two 'machines' wh ich have to be
a ble to s uccessfully cope with t he conditions one is t h e a ircraft and t he other is the pilot and that means that particula r a ircraft a nd that
particular pilot in that particular s tate and at
that time - FOR BETTER OR WORSE.
So there are two yards ticks:
• The capabilities of the aircraft.
• The capabilities of the pilot.
It is important to realise t hat we a re talking
about that aircraft's capabilities at lhal weight
and in that con dition - a nd we ar e talking
about that pilot's capabilities at that time, in
that aircraft, with lhat degree of training, currency, ex perience, familiarity , confidence,
fatigue and well-being.
The first decis ion is fairly clear-cut. We can
compare the conditions that exist with the published and tested capability of the aircraft such
as runway length r equired, crosswind limits,
weight limits and t hreshold speeds - all blackand-w hite, documented criteria. Only in dire circumstances wou ld a pilot deliberately take the
ai rcraft beyond those limits.
The first decision then is an easy one - if we
are honest about it and if we know t h e limits
and capabilities of our aircraft.
'
The second decision is the hard one. We have t o
admit to ourselves that we may not be as current in crosswind conditions as we should be,
that we a rc a little tired and hungry, that we
a re a bit eager to get onto the ground, that we
are not so familiar with this particular aircraft
in this en vironment, that we are not so sure
that we can cope safely with the conditions or
with an approach into this particular strip at
t his time of day .. .
This is wher e our 'second self' comes in handy.
If we cannot admit to our limitations then our
alter-ego w ill cast doubts in our mind and we
s hould be r eceptive to those doubts. By all
means we can continue the approach to full y
explore the conditions but do so with the intention of going around - keeping that escape
route open and planning on us ing it .
So t here are two decisions, two yards ticks. Our
decis ions aren't necessarily good by being
quick. They are good decisions by ens uring a
high probability of s uccess while retaining an
alternative course of action for the safe survival of ourselves, our passengers and our
aircraft.
Application -
We go through a certain procedure to pos ition
the aircraft for a landing. We go through a
series of ch ecks to prepare the aircraft for
landi ng and we set certain targets for ourselves
in establishing the approach. These may not be
conscious steps but nevertheless they' re there
in one form or another. It seemed valuable to
try to integrate them in some way.
( j)
So 'Application' includes:
• procedures;
• checks, and
• standards.
procedures
0
We follow a procedure to enter the circuit and
position for a landing. There are set patterns
th at we fly and they are not just for traffic
separ ation purposes. They are the basis for consistency in the approach and they are to give us
time and cues to initiate checks, to weigh up
th e conditions and to make decisions.
The square circuit is not just a relic of pre-war
aero clubs. It is a sens ible way of entering the
circuit so that we can look for other a ircr aft
and know where to look and so that other aircraft can look for us and know where to look.
We can stabilise the a ircraft and take time to
examine the windsock, assess the drift at
circuit height and assess the strip , the
approaches and the overruns. It gives us time
to look at t he effect of the conditions on other
air craft in the p attern and to adjust ours
accordingly - all because we use a common
and consistent procedure for joining the circuit.
checks
Checks are the formal way of preparing the aircr aft and the pilot, for landing. They also ser ve
to double-check the critical, life-preserving
items before we are committed to concent r ating
on the approach. Much has been argued for and
against written checklists versus memorised
checks. As long as they are complete, done in a
thorough and consistent manner , done in the
same p lace each time and a lways r epeated if
interrupted, then I don't think it matters too
much whether they are written or not.
The accidents show that there are sufficient
distractions to warrant both a downwind (prelanding) check and afinal check of critical items.
Remember ... PUF, PUF, PUF, PUF, PUF.
the second step
We have made our decision to continue with the
approach. We have considered the wisdom of
that decision and we are now ready to do someth ing about it. Application is t he way we put
the decision into effect.
While looking at the factors that would lead to
a successful landing I came to the conclusion
that there were considerable adva ntages to be
gained by a dopting a seque ntial and logical
approach to landing a n aircr aft .
standards
0
Consciously or otherwise, we each accept acertain degree of accuracy or a certain degree of
control when we fly. Perhaps it's a compromise
between the workload necessary to achieve a
certain accuracy a nd the acceptability of
slacker tolerances - and w heth er or not someone is watching. The end result is t hat each of
us has standards that we are prepa red to
accept. Perhaps we tell ourselves t hat we could
achieve gr eater accuracy if we wanted to, but if
it isn't necessary, why bother? Perhaps we sa ve
our con centration for t hose difficult occasions
- so that we have something in reserve. Perhaps we just accept the s tandards that our
instructor, chief pilot or our colleagues s et for
themselves and they become good enough for
us. Perhaps we kid ourselves.
More importantly, there are standards t hat the
aircraft demands - tolerances t h at t he aircraft
can accept in regard to minimum speeds at that
weight and configuration , maximum speeds
beyond which it is difficult to control near the
ground or beyond which the nosewheel may
contact the runway before the mainwheels.
There is a maximum height that the aircraft
can accept over the thres hold and still be able
to s top in the available runway. There is a
minimum height that the aircraft needs over
the threshold so that it can respond to longitudinal control inputs and be able to flare safely.
There is a maximum sink rate that t h e aircraft
can accept before the undercarriage and structure w ill be damaged. There is a maximum sidcload or drift angle that the a ircraft can tolerate
on touchdown before the gear will fail laterally.
Don't be concerned. These tolerances are e as ily
achieved. Aircraft are designed, t ested are certificated to ens ure that the toler ances are
achievable by average pilots in normal circumstances. Furthermore, our training and flight
tests are designed to en sure that we are able to
achieve tolerances well within those needed for
the aircraft to perform safely. All it takes is
application.
Of all the factors associated with landing problems excessive speed is a significant, recurrent
problem. Yet it is fairly easy to control - if we
have consciously set ourselves a ta rget.
The tolerances aren't the re to s how our passenger s that we are the world's greatest pilots but
to tell ourselves whether we are ma intaining
the degr ee of control that we should have for
the conditions that exist and the runway
available.
Technique is what you look at
and what you do about it
I deliberately risk opening this Pandora's Box
because of recent developments that have come
to light.
Let's assume that we h ave done the right thing
and made a conscious decision - two in fact.
We have u sed standard procedures, thorough
checks and we have set the appropriate standards. We have considered the conditions and
we are mentally prepared for a go-around while
setting ourselves up for the approach. We are
on late downwind and we need to know the
optimum technique for controlling the approach
a nd landing and we need to know what
references to use in judging the approach and
flar e.
�I
Aviation Safety Digest
134
So how should we fly?
There is no right way or so I am told. There are
pet theories, secret techniques and much folklore. But the fact remains that the most crit ical
phase of flight is apparently the least understood and the least conclusive as far as technique is concerned.
How do you safely and consistently land an aircraft? I think this is where I came in!
For what it's worth I will describe my way of
doing things and why I do it this way. I will
later introduce you to some other ideas on the
subject. Please discuss them with your
instructor, yo ur colleagues and local Examiners.
For me the essence of a good approach and
landing starts with the circuit. Above all else I
aim to minimise the variables - I aim for constancy. I fly a comfortably wide and long
downwind leg so that I have plenty of time to
assess the conditions and complete the checks
well before I have to think about flying the
approach. In this way I can devote all my attention to flying the aircraft and reading the signs.
I am not vulnerable to distractions or they are
at least minimised because I know I have set
things up and I know I have completed a ll the
checks.
On downwind I pay particular attention to
selecting my threshold speed and my touchdown point. These give me my two approach
goals - the aircraft attitude for the approach
and the aim-point on the runway. I turn Base in
the same position and in the same way each
time - just like entering a descent - Power,
Attitude, Trim, only in this case I lower part
flap. I reduce the power as I enter the Base
turn, hold the attitude until the airspeed decays
to the flap limit and I lower the flap as I adjust
the attitude for my approach speed.
Next I take care in trimming the aircraft accurately. In this way, the aircraft's nat ural stability will help maintain my a pproach attitude
(angle of attack) and hence approach airspeed.
It's like riding a horse - if the aircraft is in
trim, it will go where I point it - if not, it will
resist going where I want it to.
On Base I have another careful look at the
w indsock and I look at both ends of the runway
II
!
to help me to imagine an extension of the
centreline that I can use as a reference for judging the turn into Final. I turn as if I was turning into my driveway. I turn early rather than
late - particularly in conditions where there is
a tailwind on Base - and I am ready to
increase bank in the early part of the turn so
that I don't find myself having to tighten the
last part of the turn.
As I line up on Final I complete my final check
- PUF - make my final decision and if that
decision is to continue, I lower full flap, adjust
the attitude and re-trim the aircraft.
From here, I aim to fly my eyes on a constant
path to the aim-point. I make continuous small
corrections and fly my eyes down the sight-line
almost irrespective of where the nose of the air craft is pointing . It's like pushing a shopping
trolley down the aisle at the local supermarket
- it doesn't matter so much where it's pointing
- it matters where it is going.
My primary r eferences on Final are:
• the aim-point on the runway - t hat is
whether it is maintaining a constant position
in the windscreen,
• the attitude of the aircraft - that is the
nose in relation to the horizon, and
• the airspeed - which of course tells me if I
have the correct attitude.
My continuous scan is - aim-point - attitude
- airspeed - aim-point - attit ude - airspeed. This constant approach technique
enables me to arrive over the threshold at a
constant height, at a constant airspeed, in a
constant attitude and in a constant configuration each time. All the variables are stabilised
and this gives me a constant basis for starting
the flare.
But hold off! Before we discuss the flare let's
digress a little and let a couple of pilots talk
about their approach - and let's recall how we
got her e in the first place: ·
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------------------------------------------~-
• DECISION
• APPLICATION
• TECHNIQUE
Feeling a little query?
The ingredients of a safe landing 0
The AIRFLOW column is intended to promote di sc ussion on topics re lating to avia.tion safety. Input from student pilots and
flying in st ructors is parti cu larly we lcome.
Anonymity w ill be respected if requested.
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Aviation Safety Digest 134 / i
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AND THE WINNER IS ...
The Digest photographic competition was a
great success and I would like to thank all who
participated. There were over five hundred
entries and the standard was high. Judging is
complete and the winners are:
Category One
- the open category for the
best overall photograph
was won by Ron Israel
with his print titled
'Scottish Pioneer'.
Category Two _- the category for a photograph on a safety theme
was won by Bill Young
with 'What's in these
drums?'.
Category Three - for the best black-andwhite photograph was won
by P. Crowe with 'A little
low wouldn't you say,
Louie?'.
I wish to subscribe to . . . .. . . copies of Aviation Safety Digest for fi ve issues at $16.00,
including surface postage in Australia and overseas.
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Dear Sir,
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Three categories were judged:
Category 1 - For the best print or transparency
on the general subject of Australian civil aviation
or Australian civil aircraft. The judges' emphasis
in this field was photographic and artistic quality.
Category 2 - For the best picture illustrating a
safety aspect or an unsafe aspect of Australian
civil aviation. A clue in this field was that the primary
contributory factor in aviation accidents was the
'human factor'. The judges' emphasis was the
'message' and how wel1 the photographic design
conveys that message.
Category 3 - There was a specific prize for the
best monochrome print. Bl ack-and- white
photographs in particular are a valuable
contribution to the Digest. The judges l ooked
for photographic skill and artistic composi tion
which best exploited the unique quality of the
black-and-white photograph.
. . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............
...... . .... . . ... ...... . .......... .. . . ... ... ... . .......... ..... ...... . . . .
.............. . ... . ..... .. ....... . ... ..... ....... ... . . . .... ......... . ....
................. . .............. . .... ... .. .. ............... . ... ..... . ...
c
Yours sin cere ly, .............................. . .. ... . ... · · · · · · · · · · · · · · · · · · ·
Name: .. ... .. . .... .... . .......... . .... . . ...... .. . . ................ .. .....
Address: ........ . . .. . . . . . . . . . .. . .. . ..... . ..... ... ... · · · · · · · · · · · · · · · · · · · · ·
Details to be published?
0
ii/ Aviation Safety Digest
No name
134
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Initials okay
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Full name okay
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Three prizes will be awarded as fol1ows:
Category l - A Nikon
F-301 Program/ MotorDrive Camera with a
50mmll.8 lens.
Retail Value:
AS 1.035.00. This is a
state-of-the-art
, automatic camera
with manual reversion
and integral film-wind.
Category 2 -A Nikon
FG-20 Auto/ Manual
Camera with a 50mm
11.8 lens.
Retail Value: AS725.00.
The FG-20 is a 35mm
single-lens reflex with
aperture priority
exposure and manual
over-ride.
Category 3 - A Nikon
L35 AWAf Auto-Focus
camera with built-in
flash.
Retail Value: AS595.
This is the rugged,
waterproof. fully automatic Nikon with builtin motor-drive.
You may recall that Ron also won our last
competition but I should add that he only just
scraped in. The final selection was very close
and took serious deliberation. The judges were
myself. Mr Kevin Ginnane-very experienced
aviation photographer - and Mr Harvey
Ritchie - a previous editor of the Digest and a
very experienced pilot and accident
investigator.
Congratulations to the winners and my thanks to
all participants. 'I will be publishing several
entries in future issues of the Digest and the
winners will appear in the next issue .
Aviation Safety Digest 134 / iii
�Aircraft accident reports
Second quarter 1987
The following information has been extracted from accident data files maintained by the Bureau
of Air Safety Investigat ion. The intent of publishing these reports is to make available
information on Australian aircraft accidents from which the reader can gain an awareness of the
cir cumstances and conditions which led to the occurrence.
At t he time of publicat ion, many of the accidents are still under investigation and the
information contained in t hose r eports must be considered as preliminary in nature and possibly
subject to amendment when t he investigation is finalised.
Readers should note that the information is prov ided to promote aviation safety it intended to imply blame or liability.
in no way is
Preliminary data indicate aircraft type and regis trat ion , location of accident, date, category of
flying , pilot licence and rating, and total hours.
Preliminary reports
The following accidents are still under
investigation
Fixed Wing
Britten Norman BN2-A21, VH-SBH, Mabuiag Island Qld.,
02 Apr. 87, Charter - passenger operations.
Du ring the later stages of t he approach, the aircraft developed a higher rate of descent than desired . The right
maingear subsequently struck a sand-filled drum which was
located a bout 20 metres prior to the threshold. The impact
resulted in the right wing being buckled and one of the
r ight engine mounts fracturing. The pilot reported that he
did not believe that the landing was heavy and as a consequence did not d iscover the damage on a subsequent superfic ia l inspection before continuing the flight.
Cessna T337-B, VH-DPX, Maer Island Qld., 07 Apr. 87,
Charter - passenger operations.
The pilot reported that he had difficulty obtaining effective
braking d uring the landing roll due to a grassed, wet strip
surface. He initiated a groundloop but the aircraft drifted
sideways off the side of the strip prior to the upwind
threshold.
Cessna 337, VH-RDY, Maer Island Qld., 09 Apr. 87,
Charter - passenger operations.
The takeoff was apparently normal up until the aircraft
encountered two areas of standing water at about the midpoint of the strip. T he aircraft was slowed considerably and
subsequently overran the strip before encountering t hick
vegetation.
Cessna 182-K, VH-DQR, Mt Isa Qld., 13 Apr. 87, Noncommercia l - pleasure.
Shor t ly after touchdown the nosewheel fork faile d. This
allowed the nosegear strut to dig into the strip surface and
resulted in the aircraft overturning.
(
Rollason Beta Standard, VH-IW A, Kooralbyn Qld.,
07 Apr. 87, Non-commercial - pleasure.
It was reported by a witness that the aircraft bounced several times on landing and ran off the strip, collapsing the
ma ingear.
The accident was not reported by the pilot and attempts to
locate the pilot and wreckage have so far been
unsuccessful.
Cessna 152-M, VH-UFU, Bribie Island Qld., 04 May 87,
Instructional - dual.
During a flying training sortie, the instructor simulated an
engine failure by moving the mixture control to the idle cutoff position. The student closed the throttle and pulled the
carburettor heat on, t he instructor then moved the mixture
control to rich. During the descent the throttle was opened
twice. Prior to commencing a go-around, at about I 00 feet
above ground level, the student moved t he carburettor heat
control to cold. At about 200 feet, on climb, the instructor
simulated another engine failure by again moving the mixture control to idle cut-off. As soon as the student lowered
the nose of the aircraft, the instructor moved the mixt ure
control to rich, with the throttle open. However, there was
no response from the engine and the aircraft was
subsequently landed in swampy terrain.
Jodel Dll, VH-DRJ, Archerfield Qld., 06 Jun. 87, Noncommercial - pleasure.
Just after the aircraft became airborne, the pilot heard several loud bangs and noticed pieces of fibreglass from the
cowls fly past the canopy. Believing t hat t he cowls may
come adrift, he decided to land the aircraft in a small paddock just outside the airfield perimeter fence. The a ircraft
touched down heavily on t he soft, wet ground and after
travelling only five metres, the propeller struck the ground.
The aircraft came to rest after a total ground roll of 34 metres.
An inspection of the a ircraft revealed that the upper and
lower sections of the cowls had come ap art following the
failu re of the fibreglass at the screw-holes where they are
connected.
Cessna 402-C, VH-WBQ, Bundaberg Qld., 21 Jun. 87, Noncommercial - aerial ambulance.
The flight had been arranged to transport a critically
injured patient to hospital in Brisbane. The pilot advised
the Brisbane Flight Service Unit (FSU) that the aircraft was
taxiing at Bundaberg and two minutes later advised that
takeoff was being commenced from runway 14. No further
t ransmissions were received from the aircraft and witnesses
reported hearing the sound of an impact shortly after the
aircraft took off.
The investigation revealed that the aircraft had struck trees
800 met res beyond the airfield boundary. It t hen continued
through medium-density timber for 177 metres before
impacting the ground. The wreckage had been a lmost
totally burnt out.
Cessna 206, VH-ESM, Tilpa N.S.W., 12 Apr. 87, Noncommercial - business.
Enroute to the destination aerodrome, the aircraft suffered
an electrical system failure. The pilot selected the gear
down in the circuit area and then used the emergency low-
A viation Safety Digest 134 / v
�ering handle. However, he believed this handle jammed
before the gear was fully extended. He then attempted to
re-cycle the gear electrically and mechanically several
times. When all efforts to positively lower the gear had
failed, he carried out a safe wheels-up landing. Initial investigation revealed that the emergency lowering system was
serviceable and the jamming reported by the pilot was probably the resistance felt when the gear was in the down-andlocked position.
Cessna 210-K, VH-CHL, Dubbo N.S.W., 14 Apr. 87, Noncommercial - pleasure.
The pilot intended to conduct a series of night circuits and
landings in order to maintain currency. On the second circuit, the gear was selected down but failed to fully extend.
All attempts to lower the gear were unsuccessful and the
pilot considered that the symptoms indicated a complete
loss of hydraulic fluid. The aircraft subsequently touched
down on the partially extended gear which collapsed as the
aircraft slid to a halt about 250 metres from t he initial
touchdown point.
Piper 34-200, VB-SEN, Trundle N.S.W., 20 Apr. 87, Noncommercial - pleasure.
When t he pilot arrived at his destination, it was after last
light and there was no strip lighting available. The pilot,
nevertheless, decided to land and although he believed he
had aligned the aircraft with the strip correctly, it was in
fact lined-up to the left of the strip. After touchdown, the
aircraft ran through a washout and the nosegear and left
maingear collapsed.
De Havilland 82-A, VH-PFL, Camden N.S.W., 26 Apr. 87,
Charter - passenger operations.
The pilot reported that after commencing the takeoff run,
when he applied forward pressure on the control column to
raise the tail, the tail rose more rapidly than normal. He
was unable to correct the situation and the propeller struck
the ground several times before the aircraft overturned.
Cessna 172-M, VH-MWS, Port Macquarie N.S.W., 23 Apr.
87, Non-commercial - pleasure.
Prior to commencing the flight, the pilot received a briefing
on the meteorological situation. This briefing indicated that
the flight under Visual Flight Rules (VFR) would not be
possible over the route and that the conditions were
unlikely to improve during the day. The pilot apparently
decided to check the weather situation for himself and submitted a flight plan for a flight to Port Macquarie. The plan
indicated that the flight would comply with the Visual
Flight Rules. The aircraft departed Tamworth but failed to
arrive at the destination before the expiry of the nominated
SARTIME.
A land and air search was commenced but no trace of the
aircraft was found and the search was suspended after five
days. Two days later the wreckage was located by an a ircraft conducting a private air search.
The aircraft had flown into tall trees on the top of a 3500
feet high ridge line. It had been torn apart by the impact
forces and the wreckage was spread over a distance of
some 90 metres beyond the initial impact point.
Auster J5/ 190, VH..SCO, Luskintyre N.S.W., 16 May 87,
Non-commercial - pleasure.
The aircraft was one of a group attending a fly-in and the
pilot had been conducting a photographic sortie in company
with another vintage aircraft. After the completion of the
exercise, the aircraft was observed to descend to a low
level. It then collided with a set of power lines some 1.5
kilometres from the strip and subsequently struck trees
before falling to the ground.
Piper 28, VH-UZT, Bankstown N.S.W., 27 May 87, Non·
commercial - pleasure.
The pilot intended to conduct a short fli ght using Night
VMC procedures. The aircraft had reached a height of about
250 feet above the ground when the engine commenced to
run roughly, with an associated loss of power. The pilot
applied carburettor heat but was unable to regain climbing
power. A skidding turn was made and the pilot positioned
the aircraft for a downwind landing on the aerodrome.
vi / Aviation Safety Digest 134
day . During a break for a meal, the pilot discussed the presence of a power line which crossed a creek on the property.
Immediately following the break, the pilot spread a portion
of the load before turning and following the line of the
creek. Witnesses believed he was proceeding towards an
area which required clean-up runs. The right wing of the
aircraft struck and became entangled in the single-wire
power line and the aircraft crashed into the creek bed. A
fire broke out on impact and consumed the wreckage. The
particular power line was suspended from poles on either
side of a gully, with the span between the poles estimated
to be some 700 metres.
Touchdown occurred on an unlit area and the aircraft
bounced, before stalling at a low height and landing heavily
on a taxiway.
Bede 4, VH·ECW, Hoxton Park N.S.W., 07 Jun. 87, Noncommercial - pleasure.
At a height of about 350 feet after a normal takeoff, the
engine commenced to run roughly. The pilot considered that
the problem may have been caused by part of a propeller
blade becoming detached. Power was reduced and the pilot
commenced to turn back towards the aerodrome. A substantial amount of height was lost during this turn and the aircraft was seen to make a number of lateral oscillations. It
then struck the ground in a tail-low, wings-level attitude at
relatively low-forward speed.
Pitts Sl-E, VH-XII, Bendigo Vic., 18 Apr. 87, Noncommercial - pleasure.
At the conclusion of an aerobatic sequence, the pilot posit ioned the aircraft for a landing on the grass flight strip.
At the time, there was a crosswind of about eight knots
with occasional gusts. Towards the end of the landing roll
the aircraft groundlooped and the left maingear collapsed.
Smith 600, VH-BKS, Cooma N.S.W., 08 Jun. 87, Noncommercial - business.
About 200 metres from the start of the takeoff roll, the aircraft made a smooth turn to the left through some 15
degrees and departed the side of the runway. Shortly after
leaving the runway, the nose of the aircraft rose steeply
and the aircraft became airborne briefly before settling
back onto the ground. It then continued over an embankment and collided with a fence. The pilot later indicated
that he had been unable to maintain directional control of
the aircraft and he had attempted to force the aircraft into
the air in order to avoid a collision with T-Vasis equipment
on the side of the runway.
Piper 28-161, VH-TRV, Morrabbin Vic., 21 Apr. 87,
Instructional - solo (supervised).
The pilot was carrying out a session of solo circuits. The
a ircraft rounded out high and subsequently landed heavily
causing damage to the nosegear.
Beech C24-R, VH-EDN, Moorabbin Vic., 10 Jun. 87, Non·
commercial - pleasure.
The pilot was conducting a practice flight in the training
area when he noted that the radio had failed. He was concerned because of approaching last light and made a
no-radio entry return to the aerodrome. A flypast of the
Control Tower resulted in a red light being displayed
towards the aircraft and a go-around was conducted. The
pilot selected the landing gear down but there was no cockpit indication of the position of the gear. Because he was of
the opinion that t he aircraft problem was related solely to
communications, he did not consider using the emergency
gear system. The aircraft subsequently touched down with
the gear retracted.
Investigation revealed that the aircraft battery was discharged. The pilot, who was unfamiliar with the aircraft
type, had not turned on the alternator field switch during
the pre-start or pre-taxi checks.
Cessna Al88B Al, VH-EUU, Dubbo N.S.W., 11 Jun. 87,
Aerial agriculture.
On touchdown following a superphosphate spreading operation, the pilot heard a loud cracking noise from the left
side of the aircraft. Shortly afterwards, the left mainwheel
detached, the aircraft swung sharply and tipped onto its
nose, before coming to rest in an upright attitude. The left
mainwheel axle was found to have fractured.
Beech D55, VH-MKE, Bankstown N.S.W., 19 Jun. 87,
Charter - cargo operations.
Following a normal approach for a night landing, touchdown was made on the main landing gear. The pilot then
noticed that the nose was lowering by an excessive amount
and he carried out a successful go-around. Examinations
from the ground and from a helicopter equipped with a
searchlight revealed that the nosegear was inclined at about
30 degrees to the vertical. The position of the nosegear did
not alter when the gear was cycled and the pilot subsequently carried out a safe landing with the maingear
retracted.
Beech 58, VH-PBU, Bankstown N.S.W., 23 Jun. 87, Noncommercial - practice.
After having completed an endorsement on the aircraft
type, t he pilot was instructed to carry out a period of solo
circuit consolidation. Two days later the pilot, using the
same aircraft, commenced a period of circuits. While on the
fina l approach for the first landing, he realised that his aircraft was gaining on the preceding aircraft and requested a
touch-and-go on a parallel runway. During the subsequent
landing roll, the pilot inadvertently retracted the landing
gear when he was attempting to select the flap-up prior to
carrying out the next takeoff.
Jodel D9, VH-PBW, Cooma N.S.W., 27 Jun. 87, Non·
commercial - pleasure.
The pilot reported that the takeoff and initial climb were
normal but a substantial loss of engine power had occurred
when the aircraft had reached a height of about 400 feet.
The engine regained power briefly but then failed completely. The pilot considered that the terrain ahead of the
aircraft was unsuitable for a forced landing and he elected
to attempt to return to t he strip . During the turn, the aircraft descended rapidly and struck the ground about 56
metres s hort of t he runway threshold.
Cessna Al88B Al, VH-ESB, Sunbury Vic., 02 Apr. 87,
Aerial agriculture.
The pilot had been engaged in superphosphate spreading
operations on the particular property since the previous
Auster J5-P, VH-BYW, Balliang Vic., 14 Jun. 87, Noncommercial - pleasure.
The observer was also the owner of the aircraft and he
intended to check the performance of the pilot-in-command
on the type. Landings were being made into wind. On the
first touchdown, the aircraft bounced and the pilot carried
out a go-around. On the next approach, the aircraft bounced
again on touchdown, to a height of about 10 feet above the
ground. The pilot held the elevator control back and opened
the throttle rapidly, intending to go-around. The engine
failed to respond and the aicraft landed heavily, collapsing
the left maingear.
Cessna 182-F, VH-RYT, Beaconsfield Tas., 02 Jun. 87,
Non-commercial - pleasure.
The pilot was approaching to land on a one-way agricultural strip. He was aware that the owner of the strip had
placed a fence across the approach end but was not aware
that there was a second fence some 15 metres in from the
first. This fence was not easy to see from the air. The aircraft cleared the first fence but collided with the second.
<
(
Transavia PL12, VH-MLJ, Gretna Tas., 29 Jun. 87, Aerial
agriculture.
The pilot took off from Cambridge, transitted to the agricultural strip, and commenced spreading on the property with
the fuel selector positioned to the left tank. Shortly after
becoming airborne on about the fifth or sixth takeoff, the
engine failed due to fuel starvation. The pilot immediately
changed tanks and placed the fuel pump switch in the high/
prime position; however, the engine did not respond. The
pilot dumped the load and carried out a forced landing
which resulted in the aircraft nosing-over. Prior to departing Cambridge, the left tank capacity was reduced by a
small quantity but the· right tank was full.
Preliminary inves tigation revealed that the fuel pump
switch was not working in the high/ prime position.
Cessna 172-N, VH-TST, Tyabb Vic., 28 Jun. 87, Noncommercial - pleasure.
A taxiway for the particular strip is a continuation of the
gravel centre section of the strip. The taxiway then makes
a right-angled turn. After a normal landing, the pilot proceeded along the taxiway but failed to negotiate the turn.
The aircraft entered a ditch and the left wing struck the
ground.
American Air 5-A, VH-SYF, Parafield S.A., 23 Apr. 87,
Non-commercial - pleasure.
The pilot was taking a group of mentally retarded children
for a flight. On the first flight, one of the children became
distressed and the flight was terminated. On final for the
first landing of the second flight, the child seated behind
the pilot became hysterical and grabbed the pilot around
the throat. A missed approach was carried out and another
circuit completed. As the aircraft approached for landing,
the child again became agitated. The pilot reported that he
was concerned about the situation and lost concentration
during the approach. The aircraft ballooned and landed
heavily.
Cessna 182-G, VH-DIY, Groote Eylandt N.T., 25 Apr. 87,
Charter - passenger operations.
The pilot reported that when the aircraft was cruising at
1000 feet above mean sea level, shortly after takeoff, the
engine note changed. He immediately turned the aircraft
back towards the strip and by this time the engine had
begun to run roughly. Attempts to rectify the problem were
unsuccessful and the pilot stated that engine power gradually reduced to nil and a ditching became inevitable.
The aircraft was ditched at low speed and floated in a
60-degree nose-down attitude. Water began to enter the
cabin through the broken windscreen. The four passengers
exited through the right door and the pilot opened and
swam out through the left-side window. After clinging to
the aircraft for a short time, they all decided to swim to
shore, a distance of about two kilometres. They were
subsequently picked up by a rescue boat. The aircraft sank
after about 15 minutes.
Piper 28-180, VH-DMB, Mataranka N.T., 26 Apr. 87, Noncommercial - pleasure.
Just after the aircraft reached the top of climb, at 1000 feet
above the ground, the engine failed. The pilot was unable to
rectify the problem a nd decided to land the aircraft on a
road. During the landing roll, the left wing struck a
roadsign and the a ircraft ran off the road, then travelled a
further 100 metres before colliding with a tree.
Piper 25-235, VH-BCP, Port Lincoln S.A., 19 May 87,
Aerial agriculture.
Nearing the completion of the task the aircraft struck a
single power line. The aircraft remained airborne but the
pilot decided to land in a paddock and assess the damage.
He found that the top 30 centimetres of the rudder had
been torn off.
Cessna 210-L, VH-TIZ, Leigh Creek S.A., 31 May 87, Noncommercial - pleasure.
The aircraft landed heavily and bounced three times. On
the third contact with the ground, the rim of the nosewheel
apparently broke, resulting in the complete oleo leg
assembly separating from the aircraft. The aircraft slid to a
halt on the lower section of the engine cowl.
Beech 76, VH-RVS, Parafield S.A., 05 Jun. 87, Instructional - dual.
When the pilot selected the gear lever to the down position,
only the maingear responded. Attempts to lower the
nosegear were unsuccessful and the aircraft was landed
with the nosegear retracted. After touchdown, both propellers were feathered; however, the right propeller did not
stop in the horizontal position and as the nose of the aircraft was lowered, the propeller dug into the runway. The
right engine was torn from the aircraft and the aircraft
slewed to the right, damaging the left wing and propeller.
Aviation Safety Digest 134 /vii
�Cessna 182-G, VH-DGI, Boyup Brook W.A., 23 May 87,
Sport parachuting (not associated with an airshow).
The pilot was conducting a parachute drop from 9000 feet.
She reported that t he cloud base was broken at about 4500
feet and that she climbed the a ircraft through a break in
the cloud cover to reach the drop altitude. After the parachutist had exited the aircraft, t he pilot found a break in
the cloud cover and descended. However, s he was t hen
unable to locate the strip and spent some time fl ying in
variou s directions until s he decided to land and ascertain
he r location . A paddock was selected and after aerial
inspection a landing approach was conducted. The a ircraft
touched down about 150 metres into the paddock in
tailwind condit ions. It then ran through a fen ce, across a
road and strnck another fence before the nosegear leg collapsed. The aircraft then nosed over and came to rest inverted.
The accident site is located about 47 kilometres south-west
of the Hillman Farm s trip.
Cessna 421-C, VH-URT, Bagga W.A., 16 Jun. 87, Charter
- passenger operations.
On arrival in the ci rcuit a rea, the pilot elected to land on
runway 27. During the final approach to that runway, he
considered that the wind velocity favoured the opposite
landing direction and carried out an overshoot, retracting
both the gear a nd flap. The pilot does not recall lowering
the gear at any stage during the subsequent circuit. Neither
he nor any of the passengers recall hearing the gear warning horn when the second stage of the flap was extended on
the base leg. The aircraft was subsequently landed with the
gear retracted.
Rotary Wing
Hughes 269-C, VH-HFC, Cairns Qld., 11 Apr. 87, Aerial
mustering.
The pilot was attempting to bring the helicopter to a hover
in the lee of a hill but found that t here was insufficient
power to arrest the rate of descent. The aircraft struck the
ground and rolled over. The pilot reported that t he conditions were very windy and believes that he overpi tched
the rotors during the manot>uvre.
Hughes 269-C, VH-CHM, Coolangatta Qld., 13 May 87,
Non-commercial - pleasure.
The heli copter was on late final approach when the pilot
attempted to open the throttle. The engine d id not respond
to the throttle movement and the helicopter was entered
into an autorotational descent. However, the rate of descent
was not arrested and the aircraft landed heavily.
An inspection of the aircraft found that t he bolt attaching
t he throttle cable to the collective/throttle linkage was
missing. The bolt and nut were later found on the floor of
t he aircraft between the seats.
Bell 206-B, VH-BLI, Coen Qld., 23 May 87, See circumstances below.
The helicopter was engaged to transport two hydrographers
to various remote sites on the Cape York Pensins ula.
About 20 minutes after departing Coen, t he Engine Chip
Warning Light illuminated. This was immediately followed
by a s harp mechanical noise from the engine area and other
signs of an engine failure. The pilot is reported to have
commenced an autorotational descent from an altitude of
about 600 feet above ground level and to have headed the
ai rcraft towards a cleared area. One of the passengers
stated that the aircraft struck trees, then impacted t he
ground in a tail-down attitude. The aircraft was torn apart
by the impact forces but both passengers were able to get
clear of t he wreckage before it was destroyed by fire.
An on-site ins pection of the wreckage revealed that the
Power Turbine Rotor Assembly had disintergrated and was
missing fro m the area of t he wreckage. The aircraft had
been on fire prior to impact with the ground. When the
engine was inspected, it was found that the number four
bearing had failed.
viii / Aviation Safety Digest 134
Hiller UH12-E, VH-FFX, Pomona Qld., 23 May 87,
Commercial.
The pilot stated t hat the helicopter was cruising at an altitude of 2000 feet when without warning the engine suffered a complete loss of power. Tht> aircraft was subsequently force landed in a tail-down attitude. The tail
boom was bent and the tail rotor gearbox separated from
the aircraft.
Initial investigation revealed t hat the t>ngine-accessory
drive had failed, causing both magnetos to cease operation.
Hughes 269-C, VH-KLQ, Scartwater Qld., 22 Jun. 87, Noncom.mercial - Aerial mustering.
The helicopter had been engaged to spot cattle for a ground
muster party. During what had apparently been t he first
sweep of the muster area, just inside the property boundary
fence, the aircraft struck a single power line. There were no
witnesses to the accident and the wreckage was not located
until about eleven hours after the wire strike.
Bell 47 G3Bl, VH-SJI, Mountain Valley N.T., 31 May 87,
Aerial mustering.
The pilot was approaching the rear of a mob of cattle when
he attempted to climb the aircraft. As he raised the collective control, the engine rpm started to decrease. There was
no suitable landing site below the helicopter, so the pilot
was forced to manoeuvre the a ircraft around several trees
to get to a suitable landing area. As he flared the aircraft
for a landing, the tail rotor contacted the ground and the
main rotor severed the trunks of a tree and two saplings.
The helicopter yawed to the left and slid sideways collapsing the left landing skid.
Ultralights
Maxair Drifter 503, N/R, Hungerford Qld., 03 Jun. 87,
See circumstances below.
The pilot had flown the aircraft to Hungerford to attend a
Field Day. The following morning he adjusted the aircraft
brakes and apparently decided to take the aircraft for a
test flighl. After taking off from the local racecourse, the
aircraft climbed to about 150 feet above the ground before
descending to fly just above the tops of the trees. The flight
continued at this altitude until the aircraft struck a single
power line and spun to the ground.
1
l
1
Chinook, N/R, Streaky Bay S.A., 07 May 87, Noncommercial - aerial application/survey.
The pilot had intended to go fish spotting in his aircraft. At
about 1730 hours, the aircraft was observed flying at about
100 feet above ground level and heading towards Streaky
13ay. No further sightings of the aircraft wt>re reported and
when the pilot failed to return home, a search was
commenced. The wreckage was subsequently lo('ated the
following morning. The aircraft had impacted in light mulga
scrub in a steep nose-down attitude.
Inspect ion of the w reckage revealed an apparent fatigue
failure of the body tube.
Hiller UH12-E, VH-HKJ, Perth W.A., 13 Apr. 87, Construction work.
The pilot intended to position a beacon on the roof of t he
Perth Control Tower. The task was to be accomplished by
sling-loading the beacon, which weighted 199 k ilograms,
below the helicopter. The aircraft was positioned about 40
metres to the north and about 25 feet above the tower. The
pilot carried out an approach to the roof and deposited the
load. The load was then released from the rope which was
attached to the helicopter. The aircraft was then manoeuvred across the roof with t he rope being dragged over
the surface. The hook on the rope became s nagged on the
guard rail and the helicopter pitched nose-down and rolled
rapidly to the right. lt fe ll to the ground at the base of the
tower, caught fire, and was burnt out.
Aerospatiale SA330J, VH-WOF, North Rankin A Rig
W.A., 07 May 87, Charter - passenger operations.
The pilot reported that when the aircraft was in the cruise
at 3500 feet, he heard a noise, followed by severe vertical
and less severe lateral vibration. The a ircraft was
descended and checks carried out in an attempt to ascertain
the cause of t he v ibration. The cause o f the vi brat ion was
not determined and the pilot decided to hover taxi the aircraft back to the platform. The aircraft was subsequently
landed on a barge without further incident.
An inspection of t he ai rcraft found that one of t he two lugs
on a main rotor blade flapping hinge had failed.
Gliders
Eiri Avion PIK 20-E, VH-MQN, Lilydale Vic., 02 Apr. 87,
Non-commercial - pleasure.
The particular aircraft is a glider fitted with a retractable
engine. Shortly after takeorr for a soaring flight, the pilot
noticed that the airspeed indicator appeared to be operating
erratically. The flight was cont inued with the p ilot estimating the airspeed , but no thermals were round a nd the pilot
decided to return to the departure point using engine
power. The aircraft stalled during the landing flare and the
left wing struck the ground. The ai rcraft s lewed to the left
and touched down while t ravelling sideways. The fuselage
was fractured during the ensuing ground slide.
Maxair Drifter, N/ R, Macksville N.S.W., 31 May 87, Noncommercial - pleasure.
The a ircraft had completed several successful flights during
the day. On this occasion, the engine commenced to run
roughly when power was reduced prior to a descending
t urn. The engine subsequently failed completely and the
pi lot attempted to carry out a forced landing. During the
approach, the aircraft collided with power lines which
crossed a gully about 300 feet above the gully floor. One
line contacted the pilot's throat, inflicting severe lacerations, and the aircraft descended to the ground out of control.
Final updates
I
•
The investigation of the following
accidents has been completed. The
information is additional to or replaces that
previously printed in the preliminary report
Fixed Wing
De Havilland DHC2, VH-AAY, Walcba N.S.W., 22 Dec. 86,
CPL/ Ag. Cl. 1, 8950 hrs.
Superphosphate spreading was being carried out, with the
a ircraft uplifting one-tonne loads every six minutes. Fuel
endurance with both tanks full was approximately two
hours. The pilot was conducting his 25th takeoff for the
day, about one hour after refuelling. Witnesses observed
that the aircraft did not become airborne at the usual point,
two-thi rds of the way along the 675-metrc strip. Liftoff
finally occurred at t he end of the strip but almost immediately afterwards, the aircraft clipped a fence. It was seen to
sink slightly before climbing at a steeper-than-normal angle
until some 250 metres beyond the fence. At this point, the
nose dropped s uddc ndly and the aircraft dived into rising
ground in a steep nose-down altitudle. Fire broke out on
impact and consumed much of t he wreckage. Preliminary
investigation revealed that the fuel selector was in the 'off'
position.
This had been the first occasion that the pilot had flown
t his particular aircraft. The fuel selector in this aircraft
was different to that in the other Beaver the pilot had operated. In the previous aircraft, rotating the fuel selector
t hrough 180 degrees anti-clockwise changed the selection
from t he rear to the forward fuel tanks. In the accident aircraft, a similar movement of the selector changed the selection from the rear tank to the 'off' position. This difference
had not been brought to the pilot's attention and it was
possible that he had not thoroughly familiarised himself
with the aircraft prior to commencing operations.
It was considered likely that the takeoff had been commt>nced with the fuel selector positioned to the almost
empty rear tank. During the takeoff roll, the fuel lowquanity bell and associated light had activated and the pilot
had changed the fuel selector by feel while continuing with
the takeoff. With the fuel supply turned off, the engine had
failed from fuel starvation and the aircraft had subsequently stalled at too low a height above the ground to
permit recovery bt>fore impact.
Piper 32-300, VH-CLF, Melbourne Vic., 09 Dec. 86, CPL/
Cl. 4/Flt. Inst., 380 hrs.
Prior to departure, the pilot had been made aware of a
Notam advising pilots to disregard temporary displaced
threshold markings for runway 27 at the destination. During the subsequent approach, the pilot noticed red and
white lighting and associated this with the displaced
threshold. Tt was his intention to land beyond these lights,
which were in fact the approach lights. Very late in the
approach, the pilot realised he was too low but before
power could be applied, the aircraft struck the lights 180
metres short of the runway. The maingear legs were torn
off and the nosegear collapsed before the aircraft slid to a
halt on the side of the runway.
The pilot had been confused by the Notam relating to the
displaced threshold but had not sought clarification prior to
departure. He had limited night-flying experience and was
unfamili ar with the presentation of High Intensity
Approach Lighting. It was evident that during the
approach, he had focused his attention on these lights, to
t.he exclusion of the runway lighting.
Piper 25-235/Al, VH-FAN, Horsham Vic., 28 Nov. 86,
CPL/ Ag. Cl. 1, 1500 hrs.
Spraying runs were being conducted over a paddock which
had power lines along one boundary. The pilot had been
passing beneath the Lines during each run; however, after
completing about two-thirds of the task, the wire deflector
on the aircraft snagged and broke the power Lines. The pilot
carried out a precautionary landing and discovered that the
rudder of the aircraft had been substantially damaged by
the wire strike.
At the point where the wire strike occurred, there was less
clearance between the wires and the ground than that available during previous swath runs. The pilot was aware of
I he situation but had been subject to a visual illusion which
had led him to believe that t here was sufficient clearance to
allow the aircraft to pass beneath the wires. By the time he
realised that the clearance was insufficient, he was unable
to take avoiding action and had elected to allow the wire to
strike the deflector rather than risk the landing gear contacting the ground. The anti-snag deflector plate on top of
the rudder had failed, allowing the wire to contact the rudder. The upper portion of this component had been torn
from the aircraft.
This accident was not subject to an on-site investigation.
Cessna Al52, VH-BYS, Dry Creek S.A., 07 Jun. 86, PPL/
Cl. 4, 287 hrs.
The pilot had intended to carry out aerobatic practice in the
Dry Creek Aerobatic Training Area. After departure, the
pilot requested, and was cleared, to operate in the Dry
Creek area up to an altitude of 3500 feet. The aircraft was
then observed to be spinning and crashed into a salt evaporation pan.
The investigation revealed no pre-existing defects with the
aircraft or its systems which may have contributed to the
pilot's inability to effect recovery from the spin. However,
it was found that at the time of the accident, the weight of
the aircraft exceeded the maximum allowable by abou t 26
kilograms.
The pilot was a member of a local acrobatic club and had
accumulated some 30 hours of aerobatic fl ight. He had been
assessed by his instructors and other experienced club
members as a competent aerobat ic pilot.
The circumstances surrounding the entry to the spin and
reasons for the pilot's apparent inability to recover from
the manoeuvre could not be determined.
Aviation Safety Digest 134 / ix
�Cessna 150-K, VB-EIS, Wondagee Stn. W.A., 15 Jun. 86,
CPL/Cl. 4, 415 hrs.
The aircraft was being flown at about 250 feet above
ground level in a left turn while the pilot was attempting to
locate some sheep. The pilot reported that the aircraft
stalled and that during the recovery it struck a bush. This
resulted in damage to the right mainplane, right wing strut,
right horizontal stabiliser and the brakelines on both
mainwheels. The pilot was able to maintain control of the
a ircraft and land at a nearby airstrip.
The p ilot's attention was diverted from the operation of the
aircraft w hilst he searched for the sheep and directed the
ground party. He had been working long hours and was
only obtaining about four hours sleep each night and considered that fatigue was a factor in his allowing the airspeed to decay unnoticed.
Cessna 172-F, VH-DFW, Musgrave Stn. Qld., 13 Mar. 87,
PPL/Cl. 4, 630 hrs.
The pilot was aware that there was an area of soft ground
on the strip. The area was marked by a cone marker which
was about ten metres in from the edge of the strip. The
pilot intended to land some 100 metres beyond the cone;
however, turbulence and strong sink was encountered during the latter stages of the approach. As the a ircraft
touched down, the tailplane struck the cone marker which
was made of galvanised iron.
This accident was not subject to an on-site investigation.
Rotary Wing
Enstrom F28-C, VH-IYP, Carlingford N.S.W., 20 Sep. 86,
CPL-H, 1418 hrs.
The pilot had been conducting a series of joy flights as part
of a school fund-raising program. Refuelling equipment was
positioned some 100 metres from the passenger loading
area. The pilot had offered to take two boys with him as he
air-taxied the aircraft prior to refuelling. After takeoff
from the passenger area, the pilot decided to carry out a
short local flight, but as he turned back towards the fuel
dump, the engine lost power. The pilot was unable to reach
a cleared area and attempted to land in a street. The helicopter collided with trees, then stuck the roof of a house
before coming to rest on its s ide in the driveway of the house.
During joy fli ght operations, the pilot did not rely on the
fuel gauge inside the aircraft. He briefed an assistant, who
relayed information relating to the fuel remaining by reference to sight gauges on t he fuel tanks. There had evidently
been a communication breakdown between the assistant and
the pilot as to the amount of fuel remaining prior to the
last joy flight. The flight had been made on t he spur of the
moment, in order to give two handicapped children an
opportunity to see their school from the a ir. The engine h ad
failed from fu el exhaustion while the aircraft was over an
area which was unsuitable for a forced landing.
Robinson R22, VH-UXI, Greta N.S.W., 19 Nov. 86, CPL-H/
Cl. 4./Flt. Inst., 2089 hrs.
Following a period of circuit practice, t he instructor was
demonstrating some enroute emergency procedures. An
autorotation was entered from 2000 feet, with the pilot
a iming for a paddock on the side of a river. He advised that
descent was continued to about 250 feet above the ground.
Shortly after power was re-applied, the helicopter collided
with a set of power lines and dived to the ground . The pilot
had noted two other sets of wires in the area but had not
sighted a set of three cables between the others until
immediately before the collision.
The helicopter was being operated outside the designated
training area. The grey oxidised power lines, which were
estimated to be between 80 and 100 feet above ground
level, were very difficult to see against the overcast sk y
conditions. The span between supporting poles was greater
than those between the other sets of cables.
x /Aviation Safety Digest 134
Hughes 269-C, VB-THY, Kalumburu W.A., 01 May 86,
CPL-H, 1500 hrs.
The pilot was engaged in mustering operations and was
attempting transition from a low-forward speed to an outof-ground-effect hover in order to turn a breakaway beast.
As it approached the hover, the helicopter experienced a
sudden partial power failure. The pilot maintained the aircraft heading, lowered the collective lever and attempted to
gain some forward airspeed. In the attempted landing, with
partial power, the helicopter struck the ground heavily and
its main rotor blades hit a small sapling. The forced landing
was made in light downwind conditions.
Investigation revealed that t he number two cylinder
exhaust valve had failed in fatigue and the valve seat and
retaining cap had failed in overload. Further testing indicated that the exhaust valve had been subject to higherthan-normal operation temperatures which would have
contributed to the premature failure of the valve.
Cessna 150-F, VH-RWI, Roy Hill Stn. W.A., 16 May 87,
Non-commercial - aerial application/snrvey, PPL,
716 hrs.
The pilot was carrying out a cattle-spotting operation prior
to the commencement of the muster. He descended the aircraft to 500 feet above the ground to get a better view of
some animals amongst the trees. The pilot reported that as
the aircraft was being returned to level flight, it was affected by severe turbulence and the pilot's door became
unlatched. While attempting to close the door, he noticed
that the indicated airspeed had reduced and that the aircraft was continuing to sink. A turn to the right, to clear
the area of turbulence, was commenced but during the turn
the aircraft stalled and entered a spin. Attempts to recover
from the spin were unsuccessful and the aircraft struck the
ground in a nose-down attitude while turning to the right.
Ultralights
Birdman Chinook WT-25, N/R, Maroota N.S.W., 24 May
87, Non-commercial - pleasure, N/A.
During the takeoff run, the engine developed a maximum of
about 5800 rpm, almost 1000 rpm lower t han expected. The
aircraft became airborne but did not achieve t he climb perfo rmance necessary to clear trees along the takeoff path.
The observer called to the pilot that he was assuming control, closed the throttle and turned off the fuel and ignition
system. The aircraft collided with t he trees and fell to the
ground.
No mechanical defect was subsequently found with the
engine or systems of the a ircraft. A number of reports have
been received concerning induction icing in this type of
engine in which there is no provision for directing warm air
to the carburettor. It was considered likely that induction
icing occurred on this occasion. The pilot had not abandoned the takeoff attempt when the loss of power became
apparent.
This accident was not subject to an on-site investigation.
Gliders
Glasflugel H206 Hornet, VH-GSC, Tomingley N.S.W., 24
Oct. 86, Glider.
The pilot had been carrying out a solo cross-country training flight when deteriorating lift forced him to make an
outlanding. The approach to the paddock selected involved
passing over a line of high trees. Severe sink was encountered and the pilot realised he would not clear the trees. He
therefore applied full spoilers and attempted a landing
short of the planned area. During the landing roll, the glider
collided with a flock of sheep killing five of the animals on
impact.
The pilot was a Japanese national who was visiting the
area. Before departure, he had advised the soaring club
that he wished to undertake a local flight. As a result, he
was not briefed on cross-country procedures and outlandings. When thermals were encountered after takeoff, he
had elected to conduct a longer flight. When the outlanding
became necessary, the pilot had misjudged the strength of
the wind and had continued downwind beyond the point
where a successful approach to the selected paddock could
be made.
Thruster Gemini, N/ R, The Oaks N.S.W., 03 Jun. 87,
Instructional - dual, N/ A.
The student had about 75 hours experience in ultralight aircraft and was undergoing a training program to enable him
to become an instructor. At about 100 feet above the
ground after takeoff, the instructor closed the throttle to
simulate an e ngine failure. The student was slow to react
and the airspeed rapidly decayed. The instructor took control and applied full power but was unable to prevent the
aircraft from contacting the ground heavily. This contact
resulted in the lower fuselage striking the ground and the
t hrottle control became jammed. The aircraft became
ai rborne again with full power applied and the instructor
turned off the ignit ion system. A second heavy touchdown
occurred before the aircraft came to rest.
Final reports
The investigation of the following
accidents has been completed
Hang Glider Ultratrike, N/ R, Holbrook N.S.W., 05 Jun.
87, Non-commercial - pleasure, Hang Glider, 300 hrs.
Although the pilot was experienced in operating unpowered
hang gliders, he had only limited exposure to powered versions. He had been conducting a short local flight and
s ubsequently advised that he had probably misjudged the
landing flare. The aircraft struck the ground in a relatively
steep nose-down attitude. The landing gear collapsed and
the aircraft overturned before coming to rest on the flight
strip.
This accident was not subject to an on-site investigation.
Fixed Wing
Piper 32-300, VH-TPJ, Sweers Island Qld., 17 May 87,
Non-commercial - pleasure, PPL, 1038 hrs.
The pilot reported that just after touchdown, he felt a
bump . As t he aircraft slowed, the nose of the aircraft sank
slightly allowing the propeller to strike the strip surface
several times. An inspection of the aircraft revealed that a
wallaby had struck and bent the nosegear strut.
This accident was not subject to an on-site investigation .
Beech 200, VH-MSZ, Tibooburra N.S.W., 15 Apr. 87, Noncommercial - aerial ambulance, CPL, 4575 hrs.
The pilot was making a night landing approach. Late in the
flare a thump was heard and shortly after touchdown, the
nosegear collapsed. The aircraft came to rest on the strip
390 metres furth er on. It was discovered that a large
kangaroo had struck the nosegear and that a number of
other kangaroos were in the immediate vicinity.
This accident was not subject to an on-site investigation.
c
Aviation Safety Digest 134 / xi
�Aviation Regulatory Proposals
Av ia tion Regulatory Proposals (ARPs) are an important means by which the Department consults
wit h industry a bout proposed changes to operational legislation and requ irements. Copies of all
proposals are circulated to relevant organisations, and occasionally to individuals for information
a nd comment . The comment received provides a valu able source of advice wh ich greatly assists the
Dep artment in t he development of the complete d documentation.
Each edi tion of the Digest cont ains a listing of those ARPs circu lated since the previous edition .
Shou ld you w ish further information about any of the ARPs, p lease contact your in dustry
organisation .
•
-
..
Number
87/ 4
•
Subject
Review of Aircr aft Maintenance
Engineer licensing system
Status
Issued 21 April 1987
Comments due 1 June 1987
87/ 9
Suit a bility of aerodromes; minimum
run way widths , opera ting cri teria
Issued 4 June 1987
Comments due 31 August 1987
87/ 13
Medical standa rds for Flight Crew
member s of a ircraft a nd Air Traffic
Cont rollers - colour perception
standa rds
Issued 14 May 1987
Comments d ue 19 June 1987
87/ 3
Review of ANO 95.4; Gli ding
operations
Issued 23 July 1987
Comments due 30 September
1987
87/ 8
'Hot' (engines running) re fuelling of
helicopters
Issued 9 June 1987
Comments due 31 Ju ly 1987
86/ 18
Aircra ft r egistrat ion
Issued 24 July 1987
Comments due 30 September
1987
Discussion paper; loadi ng of a irc raft
ANO 20.16 .1
Issued 7 Ju ly 1987
Comments due 3 1 August 1987
c
Aviation Safety Digest 134 / xiii
�AIP & AN 0 PURCHASE 0RDER Fr-=-=DR..:.:.:.:M=------=====
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HERE HAVE been many arguments about
the control of an aircraft on final approach.
_ There is no one right way. The major
'camps' are:
• elevators control airspeed and power controls
rate of descent,
• elevator s control flight path (therefore rate
of descent) and power controls a irspeed,
I~
• both control both.
Total
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explain.
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SIGNATU RE
The aircraft's flight path, angle of attack and
power are not directly displayed to the pilot.
Instead of having this vital information
directly, he has to interpret this data from the
perfor mance that results from h is control
inputs. As we learn with instrument flying, concentr ating on t he performance instruments
usually leads to overcontrolling - higher
workload and less accurate and less smooth flying - more 'meandering' than flying .
DATE _ - / _ -/ ___ _
YEAR
c
We can't see our flight path and we can't see
the a ngle of attack but we can use the next best
thing. With experience we can come to know
the appropriate attitude, configuration and
RPM that will r esult in a certain performance.
Attit ude represents a combination of angle of
attack and flight path and the power w ill sustain that flight path.
For me t here are two types of control:
instantaneous, and
• su stained .
The control column gives an instantaneous
change of flight path but must be accompanied
by an appropriate change of power if the new
flight path and airspeed a re to be sustained.
Adjustments on final approach require sustained changes and so power changes are
r equired. A minor change can be achieved by a
small power adjustment alone wher eas a major
ch ange requires both the attit ude and the
power to be adjusted.
So my way of flying fo r visual, instrument and
final approach (indeed for all flying) is to set
an attitude that I know is close to where I want
it, set the power which I know is close to where
I want, trim the aircraft and allow it to stabilise in its new flight path direction - and then
make a minor adj ustment if required.
CHANGE -
CHECK -
H OLD -
ADJUST-
TRIM is the way I was taught to fly, 'on the
clocks'. The only difference on final is that
wind has to be taken into account. This is fairly
simple to do. A ground-based a im point is used
to assess flight path direction and small power
adjustments are made to adjust the flight path
towards the aim point.
Too easy - but that's only my opinion. What
about others?
When we start to talk about technique, I am
very conscious that I am skating on thin ice. I
have published the following articles to promote discussion and to solicit your ideas.
The techniques described are not necessarily
advocated by the Department.
Before attempting these techniques, please discuss them fully with an instructor 0
�Aviation Safety Digest
134
Aviation Safety Digest
134
Choosing the
best approach
Controlling rate of descent with throttle and airspeed with
elevator is one way of making a landing approach. The
constant attitude approach is another. Here Warren Wilks
·discusses his development of this latter technique and
proposes to remove even the attitude change due to flap
extension.
Warren is CF! at the Austavia Flying School in Albury,
N.S. W. A flying instructor for over 20 years, he has been
an advocate of the constant attitude approach for some
time. He has even developed an approach aid that is
based on this attitude reference technique.
HE MOST important, and certainly the most
· unavoidable part of any flight is the land..:__ ing. And for student pilots in particular, the
difficulties in learning to make good landings
are often brought about by making poor
approaches. It's often been said that it takes a
good approach to make a good landing.
The pilot can make a good app roach only if he
has t he correct mental picture of w hat he and
his aircraft are doing [and tr ying to do], all the
way down the approach path .
The traditional method of approach was based
on airspeed as t he primary reference. The pilot
controlled the airspeed using the elevator and
the rate of descent u sing the throttle. However ,
there are a number of problems and s hortfalls
associated w ith t his method.
Firstly, because he u ses the elevator to control
airspeed, the attitude of the aircraft varies continuously as the aircraft moves down the
approach path. Thus the a ircraft doesn 't go
where it is pointed - a problem that becomes
more obvious and more disconcerting the closer
it gets to the grotJ.nd.
Secondly, for given atmospheric conditions and
aircraft weight, the airs peed achieved during
t he approach is a product of three pilotcontrolled variables:
• aircraft attitude,
• aircr a ft configuration , and
• power setting.
The pilot must juggle these variables in just the
righ t proportions all t h e way t hrough the
approach in order to maintai n a des ired
approach path. The ability to combine these
variables correctly is very much a matter of
experience .
T
Thirdly, the best approach airspeed (which is
predetermined for each aircraft) changes with
varying atmospheric conditions and aircraft
weight. The pilot must remember different
airspeeds for different occasions.
All other areas of flying are taught as sequential routines: takeoff, t urns, climbing, descending - even st all recovery. The student
practises the routine until eventually it becomes
second nature to him. This is because within
t he limits of each procedure, the ro ut ine never
varies.
But with the approach and landing, the routine
is not so clearly defined. Because the approach
technique v a ries, individual instructors find it
difficult to teach a standard procedure . Beyond
a few theoretical facts, the student is often left
to his own devices - almost forced to teach
himself - to learn by trial and error.
What then is so different about the approach
and landing?
All other areas of flying are tau ght w ith reference to aircraft att itude - the posit ion of the
horizon on the windscreen. Airspeed is just a
check, a confirmation t ha t the attitude is
correct .
But for this approach, the student is told to
ignore aircraft attitude except as it relates to a
reference airspeed. This is a complete contradict ion of all that h e has just learned. And contradictions confuse. Think of it. Except for t he
approach , she h as been told that th e safest,
easiest, most n atural way to fly is by attitude.
Now she is asked to change from being an
attitude-reliant pilot to being an airspeedreliant pilot - but only during an approach.
Where on ce the right at titude and throttle setting meant the right airspeed for the prevailing
conditions, she must now make corrections to
the reference air speed for extremes of weight,
wind and weather.
The only words of encouragement I can offer to
the student pilot in this position is that s he is
in good company. We all find it difficult .
So wh y do we use air speed as a r eference during the approach? Simply because there didn't
seem to be a better way . Airspeed was the cue
for an gle of attack and we ther efore made certain of not going too far above or below a particular airspeed. Airspeed was the critical
parameter on final approach.
Over the past few years, we at Austavia h ave
been convinced that attitude reference is a
better way.
The ideal approach is one which has a constant
and consistent approach angle. If we could
gua r antee to maintain a constant approach
angle each time , we could start each approach
from th e same point every time and land at t he
same point on the air strip ever y time. And how
much safer th at would be!
The t raditional difficulties associated with
learning, teaching and making an approach
would be simplified if we could ju st adopt a
constant approach angle - and t he s implest
way to maintain a constant approach angle is to
maintain a constant lift/ drag ratio throughout
the approach. If t he lift/ drag ratio remains constant, the approach angle must remain constant.
What affects the lift / drag ratio of the aircraft?
A flare for
landing
• the aircraft body angle - the attit ude of the
aircraft as it moves t hrough the air,
• the power setting drag,
thrust, affecting lift and
• t h e aircraft's configuration - undercarriage
position and the setting of flaps or other
devices w hich alter the camber of the wing.
No mention of airspeed - because airspeed is a
product of these t hr ee. Thus, the lift / drag ratio
(and the approach angle) can be maintained by
three pilot-controlled variables: attitude, power ,
and configuration.
Now the object of our endeavours has been to
minimise t h e number of v ariables the pilot must
r ecognise and manipulate during the approach.
Bearing in mind the relationship be tween attitude, power and flap setting, it becomes obvious that th e only two variables that will affect
the approach an gle, once the attit ude has been
established , are p ower and flap.
During a normal approach we lower flap, so the
w ing configuration varies. How do we compensate for a variation in wing configuration and
thus a ch an ge in t he approach path? - by simultaneously adjusting the power. As the wing
lift/ drag ratio decreases, the aircraft begins to
move down a steeper approach path. To maintain t he initial approach path, we restore the
lift/ drag r atio by an incr ease in power. Nothing
else is required.
0
It's that simple. For a change in flap, we use
balancing power and the aircraf t cont inues
along the r equired approach path at a reduced
air speed.
Throughout the approach, the a ircraft acts as
its own approach computer. By maintaining a
constant attitude, any r equirement for more or
less power (compensating for changes in
weight , temperature, pressure, headwind etc.)
will become obvious by the movement of the
pilot's approach path away from the desired
aim point. The pilot makes automatic adjustments fo r t he above variables using one control
- the p ower lever.
What could be simpler and safer? Using t his
method of approach, any pilot, afte r a suitable
period of training , can make a safe , cons istent
and confident approach and landing. What mor e
could we ask? 0
Captian David Jacobson is a training captain on DC-9s
with Australian Airlines and is a Grade 1 instructor at the
RAAF Point Cook Flying Club. His system sounds comp licated at first but in rea lity is delightfully simple. It works
for little aircraft too.
FALL THE manoeuvres performed in
fixed-wing aircraft , the landing flare is an
_ enigma. It is crit ical to t he s afe and satisfactory conclusion of flight and yet, despite
international research, remains more an art
than a science. The way the pilot judges the
flare is still not fully under stood.
Student pilots and experienced pilots alike find
it at times alternatively satisfying and
frustr ating, simple and complex, safe and
hazardous.
In Digest 129 t he Bureau of Air Safety Investigation identified improper landing fla re as the
thir d most significant of t hirteen factors in
instances w here pilot factors were assigned to
accidents involving p rivate pilots.
In an age of technical precision, this critical
manoeuvre r emains imprecise.
This proposal discusses a practical technique
for establishing a co nsistant flare point which
does not rely on the pilot's perception of vertical height. It embraces the physical principle of
motion parallax to provide a s imple cue for
commencement of the flare. No device or modification is required and t herefor e no costs are
incurred. Safety is enhanced and the technique
is 'pilot-portable'.
Current practice
The landing flare is one of the last critical
phases of flight to which the term 'seat-ofthe-pants' may still be applied. The vast
majority of landings, worldwide, are practised
by pilots utilising highly developed qualities of
judgment, co-ordination, experience and skill.
�Aviation Safety Digest
134
Aviation Safety Digest
134
Existing flare techniques involve a critical estimation of height above the landing surface.
This is very difficult to achieve because the
estimation of h eight and the particular height
are subject to many variables, such as:
• Aircraft type.
• Aircraft size.
• Aircraft configuration.
• Glide path angle.
• Pilot total experience.
• Pilot recent experience.
• Pilot experience on type.
Pilot seating position.
• Pilot performance or skill.
• Landing surface.
• Day versus night.
• Visibility.
• Wind and turbulence.
Historically, instruction in determining a suitable and consistent flare point has been inadequate to say the least. We are attempting to
recognise and extract one flare point from a
range of acceptable flare circumstances . Generally, the best that instructors have been able to
manage is to demonstrate a suitable flare point
for a particular aircraft as being 'about here'.
The student pilot has no proper model except in
his memory, and that in itself is inconsistent.
Trial and error are the arbiters in determining
the soundness of his developing judgment.
Unfortunately, even after the basic skills are
mastered, the problem still exists because every
aircraft type requires a different flare height.
As a pilot converts to successive aircraft types,
he faces the same problem over and over. He
has no proper model at the very time he needs
one most, and there lies a clue.
Just as the student pilot consolidates his flareheight judgment, so does the experienced pilot
after conversion to another aircraft type. After
a time, he becomes comfortable with his a ircraft (if he consolidates and flies regularly),
and can land it as well as any flown prev iously.
Probably, this is a subconscious r ecognition of
something visible to the pilot through his winds hield that is providing a useable cue for flare.
Obviously, to achieve consistency some recognition and quantification is necessary.
Vague terms such as the height of a doubledecker bus , 20 feet, when the individual blades
of grass are discernible, when the ground starts
to 'rush', when you feel that your feet are just
about to r each the threshold or 'about here' are
too imprecise or inconsistent. And for a student
they are almost incomprehensible.
We need to bring this 'something' out into the
open so that we know exactly w hat we are
looking for, what works for us, and what to use
in t he future.
Another way
When properly taught, pilots have little difficulty with the concept of selecting and flying
an approach to a nominated aim point on the
landing surface. With or w ithout glide-slope
guidance, pilots can learn to fly a consistent
and stable approach angle to the aim point.
Accep ting that the glide-path angle may be
fixed within reasonable tolerances, it follows
that any point located longitudinally on the
approach path, short of the aim point, will corr espond wit h a particular vertical height
(simple triangulation).
reference distance
Flare
height
Calculation of this distance from the aim point
to the flare cut-off p oint involves energy/
geometry considerations, quickly determined in
practice but complicated to derive by analysis.
However, a suitable approximation, based on
aircraft/ approach geometry, and thorough practical testing, has provided a simple and effective alternative technique with near universal
application.
Therefore, a flare-height of greater consistency
than is possible using mere perception could be
pr ovided by a suitably chosen point along t he
approach path and overflown by the aircraft.
Much has been written on t he subject of the
aim point being the centre of expansion of a
flow pat tern, providing the pilot w ith a visual
illusion as points surrounding the aim point
accelerate radially outwards as the aircraft
approaches the ground (motion parallax).
For a given aircraft type, the distance between
the aim and impact points has provided suitable
quantification for t he flare-point estimate. Th is
distance accommodates the critical variables of
glide angle, eye height above mainwheels and
horizontal distance between the mainwheels
and the pilot's eye - when the aircraft is on a
stable approach in the landing configuration
and attitude.
reference d istance
eye path
(
The Jacobson Flare
On final appr oach, the aircraft occupies space
vertically , in practical terms between t he pilot's
eye and the main wheels. Two parallel paths
may be traced down the approach path: the
pilot-eye path which intersects the landing surface at the aim point; and assuming, no flare ,
the lower mainwheel path which would intersect the landing surface at a point called the
impact point.
The exact formula for computing the position of
the impact point is simplified as follows:
Points beyond the aim point will appear to
move upward from t he aim point, w hile points
short of the aim point will appear to m ove
downward. It is a point in this 'six o'clock' sector of the pilots' view which has proven useful.
If such a point were selected and could be
simply identified, a consistent longitudinal fix
for the flare point for a given aircr a ft could be
obtained as the preselected point appeared to
move down the windshield (due to increasing
depression angle) to the point w here it reached
the lower vision or cut-off angle (limit
depression angle) of the cockpit. This angle is
dictated by the geometry of the pilot's seating
position in relation to the aircraft structure,
where, within limits, some design consistencies
exist between aircraft types .
Distance short
of aim point
(Reference
distance)
=(
60
glide-path angle
x
The flare is initiated when , on a stable
approach, the pre-determined impact point,
appearing t o move downward from the aim
point, reaches the cockpit cut-off angle and disappears from v iew under the aircraft. In practice, it is t he simplest of tasks to notice the
aircraft overtake the impact point while flying
an approach using standard techniques. It does
not detract from the pilot's attention because
the point in question is on the a pproach centr eline in t he pilot's normal field of view.
vertical height)
of eyes above
mainwheels
+
horizontal
distance of
eyes from
mainwheels
For example: a light aircraft w ith the p ilot' s eyes 5 feet above the mainwheels
and no significant ho rizontal distance between the m -- on a 3% gl ide -path angle;
Reference distance
=60 x 5 =100 feel
3
I
(i.e. flare reference point is 100 feet short of the approach aim-point and
when that point disappea rs below the coaming, ii is time to start the flare.)
�Aviation Safety Digest
134
Aviation Safety Digest
134
The next important st ep is to locate the calcula ted impa ct point on the land ing surface, s hort
of the aim p oint. Many av iation authorities
have developed runway surface ma rkings as
dis t an ce guides, oft en at 500 , 1000 and 1500
feet from the approa ch t hreshold.
But what to aim to reach?
The gentle
touch
There are many ways to skin a cat - and it seems there
are just as many ways to land an aeroplane. Many of us
have our pet theories. This is mine.
by David Robson
I 11 K HA VE discussed the control of the ai rVV craft. I ha ve mentioned t he constant at tiSimple interpolation of these markings by the
p ilot satis fies the practical r equirements for a
vis ual fix along the approach axis. Wher e distance markers do not exist on a landing surf a ce,
the pilot ca n estimate the position of the impact
point using variat ions in surface colour or texture for identification. For night operations
from these surfaces, calculations based on the
known distance between runway-ed ge lights
provid~ t he pilot with a similar cue.
This fla re-point concept is e.>..1;remely tolerant
when compared with traditiona l perception
techniques. F or a standard 3° glide path, any
error of judgment of fla re height will, w it hin
limits, be magnified approximately 20 times,
longitudinally. In marked contrast , any longitudinal inaccuracy will be reflected as only 5 per
cent of the figure, vertically. The expanded
scale of the approach axis (approximately 20
times th e vertical dimens ion), t oget her with a
v isual fix, provides a model that is visible and
which prov ides unparalleled consis tency of
judgment for student and exp erien ced pilot
alike.
Non-standard approaches
The impact point calculated for a n ormal
approach also serves for non-standard landing
configurations, with their likely varia tions in
aircraft attitude. An aircraft on approach at a
higher attitude ( body angle) than norma l would
require a higher flare point to accommodat e t he
reduced mainw heel clear a nce. The higher attitude self-compensates beca use the lower cut-off
angle is reached further back up the approach
path, providing a n earlier cue to flare, as would
be expected . The converse also applies.
Conclusions
This technique is s imple, practical and
extre mely effective. It was develop ed and
test ed over a p eriod of three years in man y aircraft t ypes, ranging from single-engine light aircraft t o la rge j et t ransports, by civil a nd
military pilots of varied ages, abilities and
experience - and it works D
tude app roach technique that I favou r .
Warren Wilk's a rticle modifies that technique to
include th e use of power to offset the drag of
t he flap - without changing attitude further .
Captain David Jacobson has described his novel
and successful cu e for initiating t he. fl are. Well
we are a lmost on the gr ound - but not quite.
The major problems that I observed as an
instructor were related to the actual process of
flaring t h e aircraft , such as:
•
•
•
•
•
early or late rotation,
too fast or too slow an attitude change,
t oo much or too little rotation,
over controlling in t he flare,
holding the controls fixed and wait ing for the
'crunch ',
• pu shing the controls for ward to keep t he
runway in sight or to get the landing over with.
It was my feeling that t he reason for all of
these problems was t hat the pilot didn't have a
refer ence point to aim fo r. There w a s a tendency to gaze at t he appr oach a im-point, t he far
horizon, t he expected tou chdown point, some
other part of the run way or even the nose of
t he aircraft .
I w ould n ow like to intr oduce a way of
controlling the aircr aft in the fl ar e that has
helped me a nd my students to land safely and
consistently.
The flar e is in it iated by raising the nose attitude to redu ce the r ate of descent and to
change t he flight p ath . T he p ower is reduced t o
cause the s peed to decay, eit her ahead of, during or a fter the attitude change. The timing of
this power reduction is lar gely a matter of
whether the threshold speed was slightly high,
low or spot -on, whet her the descent angle was
st eep or shallow and what the shear and turbulence is like.
But let's consider t he reference point a little
further .
We can all fly vis ua lly - fly the aircraft so
t hat it w ill actually hit an aim-point. So why
not use t he same tech nique for land ing the
a ircraft?
·
'--'
I found with my students that if I could convince them to actually aim to reach the centre
of the far end of the ruriway, then the aircraft
would land itself. They knew exactly what to
aim for and they didn't 'tense up ' .
From initiation of the flare the original aimpoint serves no further purpose - it has
alread y positioned us over the threshold at the
desired height. We then need something else to
aim for . The point at the centre of the far end
of t he runway is useful for several reasons:
it is a constant point if we are flying directly
towards it [and we are not trying to guess
height or flight path from rapidly moving
peripheral cu es],
• it is t he best r eference· for distance-to-go
information,
• it is t he best reference for tracking or direct ion al information , • it is t he best reference for drift infor mation.
• it is the best reference for flight-path
infor mation.
When I'm sure that the momentum of t he aircraft w ill carr y me to the approach aim-point, I
t ransfer my attention to the centre of the far
end of the runway. I simply start to flare , close
t he t hrottle and continue to actively fly the aircraft in an attempt to get my eyes to actually
reach the centre of the far end of the runway. I
.strive to get ther e.
This refer ence then causes the aircr aft's flight
path to converge on the far end of the nmway
- both laterally and vertically. The aircraft
descends ever so slightly until the wheels
touch . There is n o tendency to overcontrol nor
for a divergent flight path to go undetected.
It only remains for the pilot to correct any drift
before touchdown and to hold the attitude on
touchdown until the nosewheel is lowered.
For landings with less than full flap or for
taildragger s, it may not be possible to keep the
flare aim-point in s ight until touchdown - t he
nose gets in th e way. I find that I can imagine
t he nose is transparent and I can picture the
posit ion of aim-point as if the nose weren't
there. There are enough cues to be able to
imagine t his without difficulty - in fact, this
may well be what we have been d oing
unconsciou sly for years.
With this flight -path aim-point and a deliberate
attempt to reach it, I have found that it is rare
for students t o misjudge th e flare and they
seem to develop confidence in their ability to
land consistently. There is j ust as much need t o
h ave t he correct threshold speed and approach
path and to start the flare at the r ight p lace
but t h e landing itself becomes consistently
easier - and the touchdown more gentle D
When everything
turns to worms
It happens to all of us occasionally!
Every contact should have an escape clause.
f F THE APPROACH doesn't turn out to be as
Bcontrolled or as accu rate as planned, then
_ there are always escape routes - provided
we have left ourselves an 'out'.
It is possible from any stage of a normal
approach or landing to go around and start again.
Within the approved limits of loading, environment al conditions and runway criteria, a light
aircraft can safely climb away from a misjudged approach or mishandled landing if the
correct technique for that particular air craft is
used.
Check the technique described in the flight
m anual for your air cr aft and rehear se it both
mentally and actually so that when the time
comes, y ou are prepared.
As a gener al guide, my normal p rocedure for a
go-around is:
• smoothly app ly full power (taking the propeller and mixture lever s forward with the
throttle),
• set the normal climb attitude, and
• partially retract the flap.
When the aircraft is positively climbing, I
retract the undercar riage.
When the aircraft is safely clear of the ground,
I retract the remainder of the flap.
For a bounce on touchdown , I force myself to
concentrate on the far end of the ru nway and
to set an attitude that will get me there.
If the bounce is bad or the aircraft gets 'hung
up', then I go aroun d.
T here are rarely situations in flight wher e th e
pilot hasn't sufficient control or where t h e aircraft hasn't s ufficient perfor mance to 'escape'
for another try pr ovided:
• the decision is made as soon as the p ilot feels
less t han comfortable with the way t h e
approach is going,
• the procedure for our a ircr aft is rehearsed at least mentally.
Both of these precautions save time and confusion when the landing 'turns to worms'.
See? Landing's not so d ifficult after all D
�Aviation Safety Digest
134
Aug 81
Char ter
Bell 20fi
Pilot heard a loud clapping noise; declared a PAN
a nd landed. Passenger 's seat-belt was hanging
outside.
Sep 81
Cessna 152
Training
Shor tly after takeoff t he pilot heard a loud noise
accomp anied b y v ibration. Returned for landing.
Pro ba ble seat -belt p rotrusion.
Charter
May 82
Hughes 269
Pilot reported noisy blades. Aircraft landed safely.
Paint on fuselage suggested that seat-belt was
flapping.
Nov 82
Cessna 206
Private
Pilot r eported loud flapp ing noise and returned for
emergency landing . Seat-belt found protruding from
door.
Private
Cessna 152
Dec 82
Pilot reported unusual loud noises coming from outside the aircraft and r equested an immediate landing.
Seat-belt trapped outside the cockpit.
Charter
Grumman A7
J ui 83
Pilot realised that the sound from the right fuselage
was caused by a seat-belt. He aband oned the takeoff.
Seat belt, belt,
belt, belt, belt,
belt, belt
A stitch in time .. .
For the sake of a . .
S THE PRINT folded out of the BASI computer I was frankly amazed at the res ults. I
:._knew of' the occasional aborted sortie due
to noises and v ibrations - noises and
vibrations cau sed by the seaL-belt or buckle
oscillating in the breeze - but I had no idea of
the frequency of these occurrences.
Have a look for yourself:
A
Boe ing 727
RPT
Oct 76
Pilot a borted takeoff du e to report from cabin crew .
Strap h a nding out _of buffet door.
Oct 77
Cessna 150
Training
Aborted takcorr due to banging noi se. Scat-bel t hanging out.
Charter
Oct 78
Cessna 206
Returned for landing due to flapping noise. Seat-be lt
hanging out.
F'eb 79
Cessna 150
Training
Pilot m a de a pre cautiona ry landing on the field due
1 to a loud met a ll ic noise ema nating from under the
foselage. Seat-belt found protruding from door.
PA32
Mar 79
Ch a r ter
Heturncd after r eport of seat-belt hanging out of door.
Jun 79
J ui 83
P A38
Private
Just after t akeoff a loud banging noise was heard at
rear of cockpit. The aircraft was landed. Lap belt
a nd buckle hanging out.
Mar 80
Cessn a 206
Charter
Returned for landing due to seat-bel t flapping in the
slipstream.
Jul 83
Cessna 210
Charter
Pilot reported t h at he was experiencing a thumping
noise outside t he aircraft. He returned fo r a landing.
A few inches of the strap for the cargo net was
hanging out of the door.
BN2
Charter
Knocking noi se from side of aircraft. Returned fo r
land ing. Unused harness hanging out.
Oct 80
Cessna 152
Train in g
Loud flapping no ise and vibration e xpe rienced during
t urn at 500 feet during nigh t VMC solo training
flight. Seat-belt fl app ing outside.
Nov 80
Cessna 2 10
P rivat e
Aircraft retu rned due to loud banging noise from side
of ai rcraft. Protruding seat-belt was banging against
side of aircraft.
.ran 8 1
Boeing 727
RPT
Retu rned due to strap caught in rear galley door.
Feb 8 1
Cessna 172
Private
Returned due to knocking noise after tak co ff. Seatbelt ba nging against side of fuselage.
Mar 8 1
PA38
Training
Ins tructor heard a very loud banging noise and suspected a n e ngine fa il u re . Scat-belt was d iscovered
hanging from door and flapping against fuselage.
Apr 8 1
Bell 20()
Business
Climbing t hrou gh 1000 feet a loud c lunking noise
was heard . Pilot landed in allotment . Seat-belt hanging out.
Apr 8 1
PA3 l
Charter
Retu rned a fte r pilot repor ted a door problem. Seatbelt was h a nging out.
Jun 8 1
Cessna 152
Private
Pilo t thought th at t he engine w as running roughly
and returned. Seat-b elt was flapping against
fuselage.
Aug 83
PA28
Private
After takeoff t h e pilot heard a severe ba nging noise
and returned for a landing. Metal end of seat-belt
was flapping against side of fuselage.
Aug 83
Cessna 152
Training
After takeoff t h e pilot heard a loud banging noise
which h e thought was corning from the engine cowling. The pilot decla red a PAN and returned for a
landing. Seat-belt was found protruding from the door.
Nov 83
Beech 58
Charter
Pilot advised s he was r eturning for a landing due to
a seat-belt hang ing out of the door. After rectifying
the seat-belt s he adv ised that she was landing with
the door open.
... and so on.
There are severa l lessons to be learnt here:
• most of these incid ents involved charter or
training sorties - understandably
• almost every pilot correctly aborted the flight
and returned f or an immediate landing.
As pilots-in-command, we a re r esponsible for
t he safety and security of all on board. Inst ructors a re ultimately responsible for their
students and pilots are ultimately r esponsible
for their passengers - or their vacant seats.
Every aircraft scat should possess a secured
passenger, piloL, student or empty-but-tied-up
harness.
Apart from the considerable loss of re venue due
to these aborted sorLies, there is always' the
potenLial for a more ser ious outcome due to the
distraction alone.
There are Lwo other aspects that come to light
in these incidents:
• the aborted takeoff,
• the attempted in-flight cure for the problem .
The aborted takeoff
When the pilot detects something unusual during the takeoff roll, there is a critical decision
period - a p eriod in which the pilot has to
assess the extent of the problem and decide
which is the lesser of the two evils - to abort
or to continue with the t akeoff.
Certainly at the very beginning of the takeoff
roll there is no r eason to continue and the aircraft can be brought to a h alt without difficulty. As the aircraft accelerates, the problem
becomes less clear. Aborting the takeoff may
cause more damage than it cures. Ther e again,
continuing the takeoff with an aircraft that
may be less than serviceable has inherent
dangers.
There is no clear-cut, black-and-white criterion
- t he pilot mus t decide on the basis of t he
symptoms and his or her assessment of the risks.
I recently had a door come open on a Duchess
just as I lifted off. That of course is a critical
t ime for things to happen in a twin-engined aircraft and there is only an instant t o decide
what is occurring. I t hink that I waited a second to see if there wer e any changes in aircraft
beh aviour or performance, in cont rol response
or flight pat h, and I elected to continue the
takeoff and reassess the situ ation when I was
safely clear of the ground.
The in-flight cure
In one of the in cidents described above, the
pilot attempted to recover the protruding seatbelt in flight and was then left with t h e problem of flyin g around with a door that couldn't
be closed and locked. It is difficult if not
impossible to close a door in flight - you can' t
open it enough to slam it shut and often there
is some negat ive pressure that prevents it fully
closing. It is noisy and somewhat distracting
though and it makes it even more important for
the pilot to concentrate on the job-at-hand and to fix t he problem when safely back on the
ground .
It is worthwhile to muse occasionally on the
possible events and our options in various scenarios . This I believe is one of the v ital benefits
of publications such as the Digest.
Think about it - please 0
�Aviation Safety Digest
134
Aviation Safety Digest
134
Gentlemen:
We read your r ecent article 'I wouldn 't be s een
dead w ithout my bone-dome ' with interest . We
congratulate pilot Gavin Thomson for his w is dom in per sever ing a nd wearing h is helmet in
s pite of his original discomfort.
The Gentex SPH-4 helmet h as been in service in
t he U.S. Ar my since 1969 and during th ose 18
years h as been r esponsible for s aving many
lives. Consequ ently , it continues to be t he helmet of choice in the Army , Navy (SPH-3C) and
Air Force. Nonetheless, there has been a cont inuing effort to ma ke it better as technology
advan ces, a nd the r esult is a completely new
SPH helmet currently known as t h e SPH-5. The
features w hich distinguis h t his helmet from the
SPH-4, t o which it looks outwardly ident ical,
are a s follows:
• n ew lightweight shell of fibreglass on Kevlar
• new t hicker , less dense impact line r w ith
great er a rea of cover age
• new cust om-fittable t her mopla st ic fitting
liner
• new energy-abs orbing earcups
• new adjustable univers al r eten t ion
• new 300 p ound chinst rap
• new lightweight dual visor system .
(Total weight for an ext ra-large-size helmet is
less t han 3 lbs with du al visors.)
The helmet n ow complies w ith a revis ed U.S.
Gov ernment specification which substantially
increased t he impact resistance requ irements,
bot h in t he cranial an d lateral region s. This
means t hat the 'g' f orces trans mitted to the
head t hrough the helmet in a crash are cons iderably less t h an before.
Th e Aust ralian Forces have for y ears flown t he
SPH-4A which was a variant of t he SPH-4
des igned to their own requirements, and not a
standard U.S. Ar my SPH-4. It was a h eavier ,
d u al-v isor helmet syst em. In switching to
another helmet , t he RAAF did not take into
cons ideration t he prope rties of t he SPH-5,
w hich we cons ider to be u nfortunate.
P lease continue to encourage your readers to.
utilise their life-support products whenever flying. Whatever d iscomfort there may be is compensated for by the benefits of ha vin g the item
in place w hen disaster strikes. We in th e indust ry will in turn cont inue to striv e to make t he
produ cts more user-friendly , w hile maintaining
t he highest poss ible levels of protection.
Sin cerely ,
GENTEX INTERNATIONAL, INC.
Cha rles G. Ru dolf
Managing Director
Worldwide Defence Ma rket ing
Dear Sir,
In his account of a flying trip to Wolf Cr eek
Crater (Airsport, J anuary 1986), Claude
Meun ier r eported crossing paths with five
wedge tail eagles, two of which dropped into
vertical dives, and he posed the question, 'Is
t his their way of dodging aircraft?'
Dear Sir ,
Why the change of ruling w ith res pect t o DME
limits in HOLDING PATTERNS? The old rule
where t he t ime cou ld be exceeded as long as th e
DME limit w as ad hered to seemed quite logical.
Could you explain w hy the inbound t urn must
n ow be commenced pr ior to the 0 / B t ime limit,
even if w it hin DME limit?
Yours s incerely,
Brent McColl
The gr eat Englis h glider pilot, Phillip Wills ,
w riting of his experience while flying in Africa,
p ointed out tha t lar ge soaring birds such as
eagles a nd vultures are much too heavy to even
sust a in flight by flapping , much less climb to ·
any marked degree. From the groun d it requires
a supreme effort to become airborne and to
elevate t h emselves to a perch in the nearest
t ree. They are only able to flap briefly to
launch th emselves into thermals and if they
didn't find lift almost immediately, they would
ret urn t o their perch.
I am advised as f ollows:
AIP IAL-2-6 para 3.4 descri bes how to fl y the
stan dard h olding pattern. Sub-para (b)
specifies the drift allowance to be used on the
outbound leg. Procedure d esigners use this drift
allowance coupled with the proce'dure time and
th e maximum !AS to assess separation from
obstacles and other ai rcraft. If, as you propose,
you continu e outbound for a longer time than
has been allowed, you have the potential to generate a greater cross-track error than that for
w hich protecti on has been provided. Therefore,
the use of DME is to control the absolute length
of a p rocedure for f ast aircraf t an d for strong
tailwinds and not to allow slow aircraft to
lengthen p rocedures.
Several readers have writt en t o me regarding
the accident to VH-WRV at Banks town . Briefly,
the aircr aft landed at night, wh eels -up . The
pilot vacated t he aircraft after turning off the
Master s witch. A Ces sna 172 was clear ed for
takeoff, wit h the A erostar st ill occupying the
st rip. Luckily, t he instructor in the Cessna s aw
t he other aircraft in the beam of his landing
lights and managed to clear the Aerostar by 20
feet.
Comments that I have received suggest that t he
wording of the accident summary implied crit icism of t he pilot for s hutting everything down
before advising t he tower t h at t he a ircr aft was
still on the run w a y .
Both the tow er cont roller and the instructor in
the Cessn a w er e t r icked into believing t he
Aerostar was clear beca use it veered left just
before it stopped .
My view is that the pilot of the Aer ostar acted
correctly in switching-off and v a cating t he aircraft immediately it came to a st op . However , I
am not in t he busin ess of attributing blame .
Both t h e controller and the instructor wer e
deceived an d perhaps s hould have doublechecked t h at t he runw ay was clear - but it
does illustrate how easily s uch an incident can
occur.
Many moons ago while flying cross-country in a
sailplane, I spotted an eagle on the same heading about 200 metres ahead and slightly below,
so I decided to sneak up on it and give it a fright.
As is their habit and purpose in such a situat ion, t he bir d h ad its head down , scanning the
ground in search of a meal, and it was about
three metr es ahead and two metres inboard of
the starboard wingtip when it became aware of
company.
I still retain a mental sn apshot of t he look of
ter ror in its beady eye in the in stant it raised
its head and saw its attacker. The r eaction was
immediate as it rolled to the right, folded its
wings an d plunged s traigh t down.
It seems probable that eagles only take this
evasive action when they are t aken by s ur prise
or feel menaced - only two of five birds
encountered by Claude Meun ier did so - and it
is not unusu al for eagles to sh ar e thermals with
sailplanes w hen t hey have had the opportunity
t o become accustomed t o the presence of the
ot her lar ge birds .
Cons idering t hat t he best glide sp eed for the
eagle is probably about 25 to 30 k nots a nd its
ability to climb in a n emergency is practically
nil, t here is only one way to go - down . It
seems likely t ha t when eagles ar e s aid to have
attacked aircr aft, they were in fact s imply
seeking to escape by the on ly path available to
them for a rapid exit.
0
In view of t h e a bove, it would seem t hat the
rule for avoiding our feather ed friends is
around or over, NEVER UNDER!
Dear Sir,
I thought you might be interested to hear of the
following incident involving my A36 Bonanza
recently. The ai rcraft had been parked in the
open on a country airstrip 25 miles south of
Goulburn and had been left unattended for
about three weeks. When I carried out my
preflight inspection, I noticed bird droppings on
the right main gear wheel. A careful inspect ion
of the undercarriage-well revealed a Swallow's
mud nest. I removed the nest at that t ime.
On another occasion, a bout three weeks la ter,
on inspecting the un dercarr iage-wells I fo und
another Swallow's nest in more or less the same
location . On this occasion there were no telltale
bird droppings to suggest the pr esence of a nest.
Accordingly, when aircraft .are parked in the
open it is important to carr y out a careful
inspection of all possible locations for nests. On
the occasion wh en I found the first Swallow's
nest in the undercar riage-well, there was also
one in the engine compartment, which of course
became perfectly obvious as par t of the rout ine
pr eflight check. It becomes apparent that an
undetected bir d's nest could be a cause of
malfunction of the under carriage mechanism.
I might mention another hazard which is probably rather more obvious. The aircraft had
again been left in the open during some of the
torrential rain last year. My initial check for
w ater contamination was done w ith one of
those narrow plastic t ubes wh ich has a scre wd river at one end. This did not demonstrate any
fluid level but the colour of the drain con tents
did not look q uite t he normal fuel colour,
although it did have a t inge of dye. Also w hen I
tipped the contents over my hand, the surface
tension did not appear to be that of fuel.
Accor dingly, further fuel was drained off into a
small soft-drink bottle and after about thr ee or
four litres had been drained, th e fluid level
became apparent. It was necessary to drain a
further two or t h ree litres before t h e fuel presented free of water contaminat ion . It is apparent that if on inspection of the drained fluid
t here is no fluid level, it ma y be assumed that
there is no w ater contamination w h en in fact
t h e drained fluid consists en t irely of water.
This experience confirms the w is dom of
checking for the presence of w ater with the
water-detection paste s hould a ny doubts exist
about water cont amin ation .
If one has doubts whether the d rained fluid
cons ists entirely of water a small quantity of
water can be added which will of cour se provide a fluid level if in fact the drain ed fluid is
all Avgas.
G.A.
I agree. In my experience birds do indeed head
f or th e gr o'J,.tnd when they see you coming.
Your s sincerely,
Edward W. Gibson
�
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Aviation Safety Digest, number 134 (Spring, 1987)
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134
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1987
-
https://collections.heritageoftheair.org.au/files/original/9647203294c0bc035af5d77d131d871e
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Text
•CAUSES
HIGH THRESHOLD
SPEED (ESPECIALLY
WITH FULL FLAP)
AIRCRAFT FORCED
ONTO GROUND
NO HOLD-OFF
THRESHOLD FIXATION
OVERCONTROLLING WHEN
TRYING TO CORRECT A
BOUNCED LANDING
•EFFECTS
NOSE LOW AmTUDE
NOSEWHEEL TOUCHES BEFORE
MAINWHEELS
NOSEWHEEL KICKS UP OR SIDEWAYS
PILOT OVERCONTROLS {PUSHES THE NOSE
DOWN)
NOSEWHEEL COLLAPSES
PROPELLER STRIKES
AIRCRAFT BREAKS
•PREVENTION
CORRECT THRESHOLD SPEED FOR AUW AND CONFIGURATION
HOLD-OFF UNTIL LANDING ATTITUDE
DON'T FORCE IT ONTO THE GROUND
KEEP THE NOSEWHEEL OFF UNTIL THE MAINS ARE ON THE GROUND
GENTLY LOWER THE NOSEWHEEL BEFORE BRAKING
PULL THE CONTROL COLUMN BACK AS THE BRAKES ARE APPLIED
•CURE
IF THE AIRCRAFT BOUNCES OR THE NOSEWHEEL TOUCHES AND REARS UP
OR THE AIRCRAFT STARTS SNAKING DOWN THE RUNWAY:
PULL THE CONTROL COLUMN BACK TO GET THE NOSEWHEEL OFF THE GROUND
OR THE WEIGHT OFF THE NOSEWHEEL
SET AND HOLD THE LANDING ATTITUDE
IF THERE'S ROOM - CONTINUE THE LANDING NORMALLY
IF THERE'S NOT - HOLD THE LANDING ATTITUDE
APPLY FULL POWER
SET CLIMB ATTITUDE
FLAPS TO INTERMEDIATE {IF THEY SERIOUSLY AFFECT CLIMB PERFORMANCE E.G. Cl 50)
WHEN SAFELY CLIMBING - GEAR UP
FLAP UP
(IF YOU SUSPECT THE PROP HAS HIT THE GROUND - CLOSE THE THROTTLE AND STOP AS BEST YOU CAN.)
c
�Aviation Safety Digest is prepared by the
Department of Aviation and is published by
the Australian Government Publishing
Service. It is distributed to Australian licence
holders (except student pilots), registered
aircraft owners and certain other persons
and organisations having an operational
interest in safety within the Australian civil
aviation environment.
Contents
3
Editorial
Editorial
Winter
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Department of Aviation
P.O. Box 1986, Carlton South. Vic. 3053.
AUSTRALIA
Telephone (03) 667 2733
Kilmore -
apt but sad
That dreaded gap.
The keys of the kingdom
Aviation Safety Digest is also avaifable on
subscription from the Australian Government
Publishing Service. There is a subscription
form In this issue. Inquiries and notifications
of change of address should be directed to:
The airmanship checks.
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.G. T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Department. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazarduous
situations.
Cooking with gas -
turbines that is
Handling the small jets.
The single-engined light aircraft is probably the most vulnerable
vehicle of all. I don't mean unsafe. I mean that the pilot has to
take special precautions because of that vulnerability. The aircraft
is vulnerable to wind for takeoff and landing. The aircraft is vulnerable to rain in the form of pooled water or precipitation. The
aircraft is vulnerable to frost and ice. The piston engined aircraft
1s vulnerable to carburettor icing. The slow aircraft is vulnerable to
airframe icing. The VFR aircraft is vulnerable to low cloud and
reduced visibility. All are vulnerable to mechanical turbulence and
vertical gusts.
1
AIRFLOW
1
Orchestrating a non-accident
1
•
by avoiding the critical situations - and this requires some
sensitivity to be able to 'read ' the conditions - such as
watching for problems near thresholds that are partly sheltered
by trees
•
by allowing 'room to manoeuvre' - adding a small additional
amount to approach speed, picking a runway that has very
clear approaches and overruns, and picking the time of day
that minimises the risk of gusts or shear
•
by staying cu rrent in the particular environment and the particular skills that are necessary for this type of flying
•
by having a check-flight with your CFI to brush off those cobwebs.
Water, water everywhere and not a drop
to drink
The age-old problem -
1
Of all the threats to a safe flight, probably the most frequent is
simply wind - in all its various guises. The aircraft is most vulnerable during takeoff and landing and that's just where the wind
is least predictable because of frontal weather, local effects
beneath and around storm clouds, terrain effects and the influence of buildings. The aircraft's vulnerability is reflected in the
number of accidents that we have during these phases of flight.
rock your wings.
Shear terror
Winter flying can be most enjoyable and there is no reason to be
deterred from flying in winter. Just keep a weather eye open D
The ups and down of a Final approach.
The Editor,
Aviation Safety Digest
Department of Aviation
G.P.O. Box 367,
Canberra, AC. T. 2601, AUSTRALIA
Printed by Ambassador Press Ply Lid
51 Good Street, Granville, N.S. W. 2142,
AUSTRALIA
Back. Whee/barrowing is a harrowing
experience - and a recurrent one in the
accident statistics.
Poster design by Soussanith Nokham.
This vulnerability also can be countered:
A polished performance.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constrtJctive towards flight safety.
©Commonwealth of Australia 1986
ISSN 0045-1207
R851979(4) Cat. No. 86 0310 3
Front. 'Raindrops on Roses. and Dewdrops
on Noses. · A cold spring morning at Bathurst
before the SCAR 1986. Corby Starlet VH-PVS.
Photograph by David Robson NIKON F - FUJICOLOR.
Sounds gloomy, doesn't it? Bu t I say again that it isn't necessarily
unsafe - just more demanding on the pilot to maintain adequate
standards, margins and escape routes. The planning must be
more thorough. The cau tion more eviden t.
Unless otherwise noted. articles In this
publication are based on Australian
accidents. incidents or statistics.
Reader contributions and correspondence
should be addressed to:
T'S AMAZING how many images a single word can generate.
The precise image depends on our locale and our experiences
.. - winter means different things to different people. It also
varies in significance according to our professions, hobbies and
means of travel. The aviator is probably the most significantly
affected by weather - and I include mariners in that judgment.
2•~
My eyes are dim, I cannot see
I have not brought my specs with me.
DAVID ROBSON
Editor
Editor:
Editorial assistant:
Graphic design:
David Robson
Karen Hutchison
Lesley Gordon
Photographs: P 5. 17, 20
P8
P 19. 20
Cartoon:
P 15
Aphorisms:
BAS/
Ron Israel
Steve Small
Soussanith Nokham
David Robson
�Avif!!tion Safety Digest
Aviation Safety Digest
133
Kil more
apt but sad
That dreaded gap
HE PILOT and his four passengers had
p lanned a trip to Sydney and back for the
ANZAC Day long weekend. In preparation
for the flight, the pilot had obtained a flight
check in a Bonanza.
On the morning of the flight, the pilot checked
the route forecast and submitted a flight plan
at Moorabbin. The flight plan showed that the
flight would proceed via Mangalore OCTA,
below five hundred.
When the flight plan was submitted the pilot
was advised that the weather was not suitable
for a VFR flight through t he Kilmore Gap. For
those who don't know the area, the Kilmore
Gap is a route through high terrain north of
Melbourne and allows a VFR flight out of Melbourne, clear of controlled airspace - weather
permitting.
The pilot decided to delay his departure until
the conditions improved.
The pilot and his passengers subsequently
boarded the aircraft. His taxi call was not the
normal GAAP procedural call and he asked for
airways clearance which suggested he was not
current on operations from Moorabbin.
The aircraft was cleared for takeoff at 0857
hours. The pilot had not requested an update of
the weather in the Kilmore Gap. At 0904 a
radar return was observed by the Melbourne
Approach controller near Doncaster shopping
town inside Melbourne's CTR. The pilot was
asked to activate his transponder. The aircraft
was at 2500 feet and was asked to maintain
altitude and heading .
At 0908, the pilot, on request, advised that he
had Yan Yean reservoir in sight and that he
was happy to resume pilot navigation. He was_
transferred to Flight Service and reported cruising at 2000 feet.
133
The Met radar at Laverton was showing an area
of rain-bearing cloud between about Whittlesea
and Broadford and also to the west. The pilot
reported that he had received a revised area
forecast that was transmitted on that
frequency.
0
At about 0918 hours the aircraft was s ighted
over Kilmore at a height of about 600 feet agl,
heading in a north-westerly direction . The aircraft was reportedly in and out of low cloud.
Shortly after, the pilot was asked for an assessment of the weather in the Kilmore Gap.
In reply, he told Flight Ser vice that the weather
was unfavourable and that he was going to
carry out a 180 degree turn. Some twenty seconds later he advised that he was unsure of his
position and requested the aircraft's bearing
from Melbourne. An Uncertainty Phase was
declared. He was advised that the aircraft was
not in r adar coverage and asked if h~ could
climb to 4000 feet altitude and still remain VMC.
The pilot advised that he was already IMC.
He was passed the Whittlesea weather in case
he wanted to try and land there.
He was advised that three minutes earlier the
a ircraft was 30 miles north of Melbourne and
that if he turned south h e s hould come w ithin
radar coverage in a short time. Two minutes
later the Flight Service asked his heading and
altitude. The pilot replied that his heading was
120 and his altitude was 2000 feet.
Weather in the area included low cloud and
rain. Nothing more was heard from the aircraft.
I
I
(
Residents in Mt William reported hearing an
aircraft at about 0926. There was low cloud in
the area, below 2000 feet. Some heard a
muffled explosion shortly after. Another aircraft approaching Kilmore some five minutes
later was VMC at 2000 feet but reported a wall
of rain and cloud to the north and west of
Kilmore. He turned back to Moorabbin.
The wreckage was finally located by a motor
cycle rider that afternoon. Initial impact had
been in a slight right-wing-low attitude on a
heading of about 135 at an altitude of 2180 feet
on the slopes of Mt William, the top of which is
2639 feet amsl. The aircraft was apparently
under control at the time of impact.
After the initial impact the aircraft rolled
inverted before striking the ground again, 70
metres further on.
Fire broke out and consumed the wreckage .
There was no fault detected with t he aircraft
that would have contributed to t he accident.
[I'll bet you knew the outcome of this accident
as soon as I mentioned the Kilmore Gap.]
A t certain times of the year, the Gap could be
classified as a high-risk area for GA aircraft
trying to remain VMC.
The pilot here was obviously a little rusty. He
made some incorrect calls and was no), fully
current on the aircraft. To be fair he did have a
check ride before this trip but the chain of circumstances was already in motion. Once he was
in the shrouded valley his only way out was to
climb - if he turned either way there was high
ground - higher than his cruising altitude. He
maintained control of the aircraft during the
turn and nearly made it - but that mountain
was in the way. The conditions demanded a
very current, competent and confident pilot to
safely complete the flight - even then it was
likely that a non-rated pilot would have to turn
back (or climb through the cloud even if not
rated). This pilot maintained control through
the turn and apparently could have coped just
as well with a straight climb through cloud. In
this predicament it is worth assessing the situation carefully before rushing into a turn. It
may be better to climb on top, get radar assistance to a clear area and then let down visually.
Most weather in my experience has gaps in .it,
and around Australia it is often layered so that
you can safely fly on top of the scud until you
reach a clear area. In any event, the first priority must be to climb to an altitude that gives
you a safe margin above terrain. As soon as
you lose you r visual horizon, get 1OOO feet
a bove the surrounding terrain as quickly and as
safely as you can - then sort out the
navigational problem.
r
Priorities
1. AVIATE
2. NAVIGATE
)
3. COMMUNICATE
But let's not talk just about last ditch
manoeuvres. There were many opportunities to
discontinue this flight before the final turn.
Those of us who do not fly frequently have to
allow greater margins, more time and very clear
escape routes - preplanned escape r outes.
First, establish some go/no-go criteria. For
example, in the planned flight the pilot could
have said to himself, 'If the cloud base is below
1500 feet or if the visibility is poor I won't
depart the circuit. If the cloudbase is below
2000 feet I will not go beyond Ringwood. If the
cloud base is 2000 feet I will go as far as Yan
Yean reservoir a nd be ready to turn back. I will
track to the eastern end of the reservoir so I
can turn back to t he left and avoid both the
high ground to the north-east and the controlled
airspace. If the cloud base is above 2000 feet
and I can see Kilmore, I will go that far and be
ready to turn back over the township if I can't
obviously get through the Gap.'
In this way we can pre-consider the possibilities
and h ave ready-made decisions. Decisions that
will save time and confusion in the air. This
sort of mental planning doesn't take long and it
provides insurance - life ins urance.
Think about it 0
�Aviation Safety Digest
Aviation Safety Digest
133
The keys of the
kingdom
133
Maybe you check these thi ngs as part of your
normal thought processes wh ile you are flying ,
but perhaps there are occasions when one or
other item might be overlooked. Wouldn't it be
useful to have an 'airmanship' chccklist to
ensure that we hadn't missed anything
important?
Here are a couple that I have developed to keep
myself 'on the ball '. Perhaps they are of use to
you too.
Having completed the checklist ite ms by reference to the flight manual, I always run through
the pretakeoff VITAL ACTIONS,
TccMPecFISCH.
So I have double-checked the items critical to a
s uccessful takeoff. nut what about the
airmanship aspects?
0
The airmanship checks
E ARE ALL used to checks and chccklists.
We u se them to start the engine , to
functionally test the aircraft's systems
and perhaps to check ourselves. It is these latter ones that I refer to as 'airmanship' checks.
Remember the 'CLEAR' check on a crosscountry and the ' HASELL' checks before aerobatics or stalling? These are checks which go
beyond checking the aircraft to include checks
on the pilot, or more specifically, they cause
the pilot to check on factors which affect the
safe conduct of the flight, i.e. they arc
'airmanship' checks.
Having sufficient altitude or ensuring the navigation log is maintained are aspects of commonsense good airmanship, but it is as well to have
a reminder , particularly when we arc learning
or during times of distraction or high workload.
Some of you may have heard of the
'DOWNFAST' check prior to an instrument letdown, and of course the vital check that all
pilots do, the pretakeoff vital actions 'TMPFISCHH' (TT AFFIOHHHC to you RAAF
operators).
But if we examine them carefully, we may find
we are omitting the most important airmanship
points of all.
Consider the s ituation where you are about to
take off. What should you have considered in
addition to the above VI As?
What about:
Weight and balance?
Density a ltitude?
Wind velocity?
Performance charts?
Runway suitability?
Or consider the situation prior to landing. You
do a 'BUMFF' check but what about:
Wind velocity?
Runway surface?
Approaches?
Airfield elevation?
AUW and Threshold speed?
I use my own mnemonic - ' WARTS',. to ensure
I have considered all the factors relevant to the
takeoff.
'W' - WIND VELOCITY headwind component?
crosswind component?
gusts?
shear?
turbulence?
vortices?
' A' - ALTITUDE of the runway above mean
sea level (this is Pressure Altitude as
s hown on the altimeter with 1013.2 mb
set on the sub-scale - don 't forget to
reset QNH)
' R' - RUNWAY s urface - ditches, water , sand, etc
slope
length
condition - long grass, dust, wet or dry
approaches, climb path - power lines
obstructions - trees, fences
'T' - TEMPERATURE Density Altitude ( = P.A. factored for
ambient temperature)
effect on performance for takcoff and
climb
'S' - SAFETY BRIEF decision speed and decis ion point
passenger brief
self- brief of emergency procedures:
•engine failure, vibration or rough
running
• aborted takeoff
• seat collapse
• door opening
• ASI failure
SPEEDS nosewheel rotation
liftoff
initial climb
single-engine safety s peed .
0
0
Maybe yo u unconsciously consider all of these
factors. I like to have a reminder. In many
cases where you operate from one airfield of
adequate length where you know the re arc no
DA or runway problems for your particular air~raft, t hen you may choose to skip many of the
items and merely use a safety brief as your
airmanship check and have a look at the windsoc.k ~s yo u line up. Realise, though, that by
omitting any of the items from conscious cons ideration, you are taking some slight risk. It's
better to be sure.
So much for takeoff. During the climb you need
~o maintain a look-out and monitor the engine
instruments. Above 5000 feet you may lean-out
th.e mixture. For such a continuous process you
will probably not u se a chccklist - just your
normal scan. If you w ish, you could use 'FLEM'
as a cue:
'F ' - FUEL Sclection and Contents
Boost Pump and Pressure
' L'
LOOK-OUT
' E'
ENGINE INSTRUMENTS
' M'
MIXTURE and Carby-heat
(I always check carby-heat with
mix ture).
While cruising, you probably already use the
'CLEAR' check at top-of-climb and at turning
points. I use a modified version, '0 -CLARE':
'O' - ORIENTATION Are you going in th e right genera l direction? (some old hands teach a CLEARO
check to include this)
'C'
COMPASS check the D.G. a lignment and your
heading
'L'
LOG fill-in the navigation log
update ETA
'A'
ALTIMETER check area QNH and cruis ing level
'R'
RADIOposition report
' E' - ENGINE engine ins truments
mi xture and carby-hcat.
At about 15 minute intervals, I repeat the climb
check - ' FLEM ' - during the cruise, to keep
track of fuel in particu lar.
Before descent we need the mixture rich and
perh aps to pre-heat the carby throat. I do this
as part of the last routine 'FLEM' check.
Before reaching circuit height, I repeat the
'WARTS' check for landing, except I consider
the runway factors in relation to a landing, performan ce factors in relation to a go-around and
saf~ty aspects in relation to landing emergencies. Speeds, of course, include threshold
speed (bearing in mind the weight and surface
conditions), s ingle-engine safet y speed (minimum speed up to the point o(' commitment to
land), and the tolerance on the threshold speed
above which I will go-around rather than land
(on that particular runway in t hose particular
conditions).
In the circuit, I use the well-known 'IlUMFH '
check on downwind . Abeam the upw ind end of
the runway, I say to myself, 'Speed below ...
knots' (gear extens ion limit), brakes ...
As soon as I roll out on Final, I use the ' PUF' c heck:
'P ' - Propeller Full-Fine
'U'
Undercarri age Three ... confirmed
DECISION
CONTI NUE OR GOAROUND
'F' - Flaps Full flap if I a m landing.
I remind myself of my previous ly consider ed
decis.ion criteria for a go-around, particularly in
relatton to the maximum threshold s peed I will
accept under the circumstances and my tolera nces on centreline and glidepath .
Back on the ground and clea r of the runway I
stop the aircraft and use the written chcc kli~t
for the after-landing and s hut-down checks.
For aerobatics or s talling, I use 'HASELL'.
It may sound like a lot of checking but in
reality you adopt the routine very quickly and
it works. It develops a thoug ht p attern that
becomes a habit. It w ill s tay with you for your
whole flying career and it will increase the
chances of that career being incident free.
'TeeEmPeeFischh, WARTS, FLEM, 0-CLARE,
BUMFH AND PUF' arc the keys to safe flight
- the 'keys of the kingdom ' D
From now on 1·11 be more
professional about my
flying
�Aviation Safety Digest
133
Overtemperaturc on starting is relatively
unusual, but if encountered , it is rapid and if
not checked quickly, will result in a repair bill
containing s ix figures.
0
0
The airframe
There are probably four major airframe considerations to be taken into account when
t ransitioning to your first jet:
• the large range of indicated airspeed
• the prospect of high a lt itude flight
• the relatively close proximity of t he a ircraft
to the speed of sound
• the lack of propeller effect on the airframe
Airspeed envelope
Cooking with
gas
turbines
that is ...
Darryl Newman is a very experienced jet instructor and
has run jet conversions on Lears and Citations. He is currently a Chief Pilot and Check and Training Captain on
Lear 35s. I though some words of advice from Darryl
would help all of us who may be about to undergo a conversion onto jets, those who are studying the theory of jet
performance and those who may never fly a jet but who
are curious about the differences.
T
HE STEP FROM a GA light twin to your
f firs
t jet is not only the most excitin?
probably the biggest single step up m airb~t
;';ft performance that you will make in your
aviation career. As with all aspects of flying,
preparation is the key word . The more ground
work you put in, the more you know of your
aircraft's systems , performance, flight planning,
etc., the smoother will be the trans it ion. With a
little help from a tail wind, your jet can comfortably achieve a ground speed of ten miles a
minute - that's not the t ime to find that you
are uncertain of how to rectify a fuel imbalance, or be light on for knowledge of how to
flight plan to an a lternate when the destination
weath er turns bad.
Once again, it is a big step, so don't try to rush
it. Be prepared to sit in t he right hand seat and
learn the ropes for a w hile. The initial endorsement is really only the stamp in your licence the first step up the ladder. It takes hours of
route flyin g during which time you will experience different operating conditions such as
weather, changing aircraft weight, in-flight
re-planning, and the odd in-flight malfunction ,
to complete the training a nd fully prepare a
pilot to assume command of a j et a ircraft.
The aircraft is going to be at least 250 kts
faster than your GA twin, so you w ill h ave to
plan well ahead for descent point, approach
details , weather avoidance, deceleration point
etc. You must fly the aircraft at a speed to suit
your present set of conditions. You can fly
downwind at 270 kts (in CTA) if you want, and
have insufficient time to do any thing but hang
on, or reduce well in advance to the correct cir cuit speed for the aircraft w hich w ill in all
probability be within 20 kts of the circuit speed
of a reasonable-sized general aviation twincngine aircraft.
The majority of small jet air craft do not have
powered controls and therefore h ave no artificial feel , i.e. they are manually operated like
other GA aircraft. If your aircraft fits into this
category it will be requir ed to fly from ll O kts
during a lightweight approach to land , to perhaps 350 kts on descent. Clearly the aircraft
will not h ave the same 'feel' at both ends of the
speed range - the most noticeable effect being
at the high-speed end of the range where the
aircraft will become extremely sensitive in both
pitch and roll, and considerable care must be
exercised in order to avoid overcontrolling.
The following text outlines some of the more
obvious differences that you will encounter
when transitioning to y our first jet.
The engine
A jet engine is basically a very simple piece of
equipment to operate. It has only one control
lever and the further forward you push it, t he
more thrust it develops. All jet engines have
temperature limits and, w hether they be
exhaust gas temperature, jet pipe t emperature,
or inter-turbine temperature, they must be
strictly observed. In addition there are rpm
limits (Fan and Turbine) and, on some aircraft,
EPR (engine pressure ratio) to be watched.
A jet engine differs greatly from a piston engine
in the power versus rpm r elationship. In a
propeller-driven aircraft, the horsepower
delivered by the propeller is directly proportional to rpm (remember that power is
speed-related). However, with a jet engine this
is not the case. A modern high by-pass (fan )
engine will idle at approximately 30-35 per cent
N l (N l is a standard abbreviation for fan rpm).
With thrust lever advancement through to
maximum setting (usually rpm limited) only a
small amount of thrust will result from the rpm
increase to as high as 75 per cent N 1. The vast
majority of thrust will be produced between 85
and 95 per cent N 1.
With the above in mind, it is vital that the pilot
has some rule-of-thumb rpm settings for the following • the circuit
• an instrument approach
• the increase necessary for asymmet ric
operations
These settings will vary with change in aircraft
weight. However, they will serve as a starting
point from which adjustments may be made as
n ecessary . Remember, a jet engine may be relatively straightforward in its basic operating
t echnique; however, they are extremely expensive to repair if they are abused or d amaged.
even moderate airspeed excursions could put
the aircraft quite close to either the high or low
speed buffet. If you cannot avoid it (e .g. clear
air turbulence) then you must descend. By
descending you will place the aircraft ,at a level
which w ill give it greater mar gins between the
cruise Mach number and the high and low speed
boundaries.
The speed of sound
Most jct aircraft performance, i.e. the top end
of the climb, the cruise and the descent, is
predicated on Mach number (the aircraft's TAS
expressed as a ratio to the local speed of sound
- e.g. Mach 0.8 is eight-tenths or 80 per cent
of the speed of sound at that temperature).
Most aircraft have a combination airspeed
indicator/ Mach meter , so IAS and Mach number
can be read simultaneously. As Mach 1.0 (the
speed of sound) is a function of air temperature, the t rue airspeed will var y as OAT
changes. For example , at an OAT of - 45 C, a
Mach number of 0.75 gives a TAS of 440 kts. If
the OAT wer e to drop to - 60 C, the same
Mach number will now produce a T AS of only
427 kts. From this it can be seen that t ime
intervals and t herefore endurances may vary
despite a con stant Mach number being flown.
Modern jet aircraft cruise relatively close to the
speed of sound, between 75 per cent and 85 per
cent of it. As the air craft's Mach number
increases towards its maximum (MMO) there is
a sharp increase in the drag produced by t he
airframe. Obviously then , cruising at or close to
the aircraft's Mach limit while producing a high
TAS will usually involve a fuel flow out of all
proport ion to the increase in speed. If t h e aircraft is pushed beyond its MMO, the a irframe
may become unstable, even to the point where
cont rol is lost . If maximum range or endurance
is required, the figures quoted in the Aircraft
Fligh t Manual should be strictly adhered to, as
any deviation above or below the Mach number
for the par t icular aircraft weight will result in
a n increased fuel burn.
High altitude
0
0
High altit u de flight, i.e. flight above 30 OOO
feet, introduces a whole r ange of aerody namic,
performance , planning and physiological problems not associated w ith flight below 10 OOO
feet in general aviation light twins . All pilots
undergoing or about to undergo a conversion
onto a high-performance jet should complete the
RAAF passenger decompression course at Point
Cook. Whilst this will not simulate an explosive
decompression, it will give the pilot an insight
as t o what to expect should such an event
occur. One aspect of high a ltitude jet operations
that has to be closely monitored by the pilot is
t he penetration of areas of turbulence. An aircraft flying at FL450 will usua lly be w ithin 0.1
Mach of its maximum operating Mach number
and only some 30 kts above its minimum (stall)
speed. Any turbulence severe enough to cause
Lack of propwash
The airfram e is totally devoid of any effect
such as - p ropeller wash, critical engine,
torque or propeller blade effect. All the
airframe under stands is angle of attack and a irspeed, whether on on e engine or two (or three
if applicable).
In any asymmetric situation t he airframe will
perform exactly as it does with all engines
operat ing except that it will r equire additional
power from the operating engine and exhibit
yaw toward the d ead e ngine. The aircraft must
be flown continually by reference to attitude set a pitch a ttitude (and thrust setting), hold it,
obser ve t h e result, adjust if necessary and
repeat the procedure.
�Aviation Safety Digest
Aviation Safety Digest
133
133
Flight planning
Most of t he current smaller GA jet aircraft cosL
close Lo $2000/ hr to operate, and in order to geL
the absolute maximum out of every hour, accurate flight planning is essential. The capacity to
operate a jet aircraft inefficiently is almos t limitless. Setting maximum cruise Lhrust at a flight
level well below Lhe optimum for the aircr aft's
weight and having little regard for the prevailing wind compone nt will produce fuel consumption figures that will make the company
accountant's eyes water. In still a ir (a rare animal ) a jet aircraft will use less fuel per ground
naut ical mile as its operating altitude is
increased. The limit h ere being the maximum
altitude achievable at the aircraft's weignL aL
the present OAT. Simple you say. Go as high as
possible and you have it made. Unfortunately,
across Australia at v arying altitudes and latitudes, depending upon the season , we have a
series of jet streams, the strength of which can
reach 180 kts. This introduces a ll sorts of variables - can you climb above the core? Is it
worth dropping below it to improve your
ground nautical miles per pound? Is there a turbulent level? - you can 't h ave the managing
director spilling his Bourbon a ll over himself.
Close attention to the factors mentioned above
may even eliminate a possible en route fue l stop
on a long leg - a very worthwhile saving in
terms of both a ircraft operating costs and passenger inconvenience.
External
External daily in spection
Normal preflight inspection
Engine bay inspection
Fuelling procedures
Internal
Cabin familiarisation covering:
fire extinguish ers, first aid kit
location , operation of life
jackets or rafL, emergency
oxygen, emergency escape
hatches, baggage areas, use of
Lhe galley eLc.
Cockpit layouL:
instrumentation, controls,
crew oxygen, radios, navigation equipment.
Aircraft weighL and balance
Takeoff data
Crew briefing
In the air
A n ormal takeoff and climb Lo, depending on
the type, FL390 or FL410 covering:
use of climb power,
airframe and engine anti-ice,
t he autopilot.
On reaching cruise speed , the following will be
carried out:
Flight profile
All j et aircraft, regardless of size, consume
large quantities of fuel. A Lear 35, probably
one of the most fuel-efficient of all the small
jets will u se around 1300 lb (approx. 600 kg)
of f~el between Melbourne and Sydney if it is
flown efficiently. With this in mind the flight
profile must be monitored closely. Deviations
from this minimum-fuel climb s peed, excessively high (or low) cruis ing Mach number, or ~n
incorrect descent point res ulting in t he aircraft
going above or be low the optimum descent pr?file will r esult in an increased fuel burn. Dev1ati~ns below the descent profile will necessitate
the use of power to correct, and hence more
fuel. Being above the profile will r equire the
use of Lhe aircrafL's s poilers and t his is simply
a waste of energy _:___ energy gained by the consumption of fuel earlier in the flight.
The conversion
After satisfactorily completing t he en gineering
course, t he time will arrive to commence flying
and the practical side of the endorsement will
be covered something like this -
gene ral handling,
level turns,
limit ing Mach number.
This is all hand-flown in order to gain proficiency in flying Lhe aircraft at high altitude.
On completion , a s imula ted explosive decompression with an emergency descent to around
FL1 50 is conducted.
At this level the following sequences will be
covered:
handling at high a nd low IAS ,
the effect of flap, gear and the
spoilers,
steep turns,
emergen cy gear extension,
h ydraulic malfunction,
stalls,
Dutch roll,
bas ic instrument fly ing,
flight on limited panel,
unusual attitudes,
general handling with one engine
out,
engine fire drill,
engine shut-down and relighL,
and any idiosyncras ies that t he
type might display.
From her e to the Navaid work - all engine and
asymmetric NDil's, all engine and asymmetric
ILS's and a VOR approach.
0
0
The last part to be covered is t he circuit work.
By this Lime the trainee should be developing a
feeling for the aircraft and the all-important
areas of manoeuvring in Lhe circuit and low
speed asymmetries can be Lackled. The circuit
training will embrace:
normal flap takeoff,
full flap landing (us ua lly fullstop
landings),
flapless landings,
landing w ith a runaway pitch
trim,
engine failure below VI (aborted
takeoff),
engine failure after VI but before
VR (takeoff continued),
single engine landing,
s ingle engine overshoot,
crosswind takeoff and landing.
To complete the endorsement, night circuits (all
engines) are r equired , again to a full stop. This
will give you your endorsement. However,
remember that it is a bas ic training period and
it will require considerable route flying to give
you the depth of experience necessary to
efficiently command a j et aircraft.
Some pitfalls along the way:
• Never try to fly a jet aircraft by any primary
r eference other than the A.I. Attitude is all
important in accurately controlling t he airspeed, Mach number , rate of climb or descent
and altitude.
• Give yourself sufficient time to slow down to
the prescribed speeds for the circuit, an
approach , turbulence penetration etc. Any
problems you already have will treble if you
arrive 100 kts too fast.
• The aircraft will be heavier than the types
you have been flying. It will have more
momentum so sink rates on approach will
have to be more closely controlled. Get set-up
early on final and hold the approach angle.
Remember the thrust lever controls both the
rate of descent and the airspeed.
• You must have some rule-of-thumb thrust
settings for s ituations such as - circuit
speed, ILS approach and the approximate
increase required in the even t of losing an
engine. It is quite different to 'feel' power
settings in a jet aircraft.
• Descent profiles mus t be monitored closely.
Any reduction in speed on descent will result
in the aircraft going high on the profile. Correct any excursion early - if high by the use
of the spoilers, or if low by either reducing
speed slightly or by increasing power.
• Under normal cruise conditions the aircraft
will be covering ground at around seven to
eight nm per minute. The old IFR training
comment 'If you s it there for two minutes
and do nothing, you have forgotten s omething' was never more p ertinent than in a j et.
• Don 't try Lo 'do it all yourself' in Lhe cockpit.
Apart from some Cessna Citations, all jet aircraft are two crew operations and for good
reason. The company operations manual will
deLail cockpit procedures and responsibilities
- stick to t hem.
'
• To fly in a j et w ith a pilot who can accurately a nd smoothly control t he aircraft and
put it w here he wants it without high roll
rates or pulling the skin from you r cheeks is
a pleasure. Aim to achieve a t echnique where
you can get the aircraft where you want it
without the passengers ever knowing it
happened.
The two pilot cockpit
You are now (or about to become) part of a two
crew operat ion. Getting Lhe aircraft from A to B
in the safest and most e fficient manner must be
a team e ffort . The captain and co-piloL both
have a role to play, each depending on the
other for certain actions or calls to be taken or
made. It may initially seem tedious to work off
the same checklis t time and time again when
yo u feel that you could probably do jus t as
good a job by heart. Every item could result in
a n expensive aborted flight (a pitot cover left
on), damage to the airframe or engines (en gine
anti-ice on at too high a temperature), or in the
extreme, the loss of the aircraft (pitch trim
fully forward or aft and a premat ure rotation ,
or no rotation).
If the above appears a strong pitch for the u se
of the checklist, then the case of the in-flight
emergency is an even stronger one. Here the
Phase 1 checks (memory items) will be carried
out by the captain immediately following the
emer gency and backed up by the co-pilot with
the checklist to confirm the Phase 1 checks and
continue with the engine shut-down or whatever is required to deal with the situation. In
s ome aircra ft the checklist to deal with something as apparently simple as a failed inverter
consumes two pages, the actions to be taken
depend upon the position of circuiL breakers
and the effect they have on the system when
they are either pulled or reinstated. Here of
course the painstaking use of the checklist is an
absolute necessity . The moral here is not to
adopt a cavalier attitude towards the checklist,
it may well save your life, your passenger's life,
and your aircraft - not to mention your job.
Well there it is, your first jet endorsement.
Most pilots you talk to will agree it will make
you think quite differently about your fl ying.
Even your attitude towards flying a light twin
will change.
A jet is exhilarating to fly , and ver y satisfy ing
to fly accurately . Take your time a nd enjoy
your self. You're a jet jockey now 0
�Aviation SafetyDigest
133
If you are not eligible for a free issue, or if you wou ld like additional copies of the Digest:-
=
Our w·ticle 'Shades of Darkness' (ASDl.'Jl ) by
Adrian Zentner, may have shed more light on
this vexed topic than originally intended.
The u rticle rerornmended pilots obtain N DJ5
lenses. Such lenses are a neutral density tint <LS
described; however, they trans mit 15 per cen t
of ambient light, not absorb 15 per cent as
·i nadvertently suggested in the arti.cle. Lenses
that absorb only 15 per cent of light would be
'ND85' - which fortuna tely are not general.ly
available.
Sarne pilots have found it difficult to obtain
sunglasses that meet the A ustralian Standard
for 'specfic purpose' use. This is because very
few manufacturers are able to meet all the
infra-red requirements of this standard. A pair
<~{ 'ND15' sunglasses that meets AS1067 1988
for general purpose sunglasses may be con sidered quite satisfactory for flying. The Standard (many argue it is too stringent) is in the
process of being reviewed.
So for flying we recommend ND15 s1mglasses,
approved to AS1067 for general purpose use.
My apologies for any confusion this may have
caused.
A Trinidad was on track from Wonthaggi to
Strathbogie at 8000 feet, when the engine
misfired and began to run roughly. The pilot
diverted to E ssendon where he landed safely.
Subsequent inspection revealed water and contaminants such as paint and metal particles in a
sample of fuel that was drained from the fuel
strainer.
Although it is a requirement of the Daily Inspection that the strainer be drained, I don't believe
this check is included in the aircraft manual. In
my experience it is an essential check befo~e t~e
first start of the day. I have found contammation
similar to that described above. Bleeding the
engine drain is recommended .as ~ daily ch~c~ by
the engine manufacturer and m hght of this mc1dent, I would suggest that it is a wise precaution
to remove the contamination from the strainer
each morning and give it a helping hand to do its
job.
You don't need to turn on the mixture or fuel
pump - just the fuel cock. By the way , on the
TB20, the strainer drain is accessible through the
underside of the rear of the engine cowling, on
the left side.
If there is any significant contamination or if it
is a regular find, then the aircraft is unserviceable and the fuel system needs pu rging.
It may be that similar contamination is possible
in your aircraft/engine type. It would be worth
checking with the maintenance organisation just in case D
Dear Sir,
I read wi th interest t he a rticle in ASD 131
Lilied 'Y 'all come back now, y'hear'?'. The inference seemed to be that it is fine to a rrive at a
w inch gliding site with no p rior know led ge of
the operation or the s ite, have a good look
while in the circuit and then cautiously let d own .
Fair enough , but ...
Unless a gliding field has a quite separate
powe r landing are a, there is considerable possibility of con flict for the following reasons :
• A glide r's wings may be levelled prior to
takeoff as advice to other pilots or cr ew on
t h e ground that takeoff is imminent. It may
be ve ry difficult to see from the air and the
wing may be lifted only seconds before
takeoff.
• No mention is made of the fact that gliders
climb on the winch at up to 3000 ft per min
at a forty-fi ve degree angle at speeds up to
70 kt a nd may lay-off to windward by a very
cons iderable amount.
• It is stated that the cable may be several
inch es off the ground if broken. In fact, after
cable-break s ingle strand cables often form
coils up to half a metre high.
• That one sh ould even consid e r t a>..iing whe re
cables are laid is su rely less th an responsible .
• These cables, a nd t here may be more than
one, whether broken or not, are quite inv isible from the air and often fro m beyond a
s hort distance on the ground. Most certainly
from short final they would be hard to detect
given the poor forward v ie w from most powe r ed a ircraft.
• Whe n cables do break they may be anywhere
on the field , and the pos it ion of the drogue is
n o s ure indication of t he rest of the wire.
• For a number of quite good reasons, a numbe r of clubs do not permit power operations.
In our case it is outside the terms of the
lease, for example. Clubs do operate successfu lly with both winch and power operating
togethe r. However, where this is done, everyone involved has a thorough knowledge or
the situation a nd works w ithin it.
Certainly gliding clubs welcome visitors. Ho wever , unless you h ave been able to make prior
contact with that club's experienced staff a nd
been thorou ghly briefed, I am s ure you would
be even more welcome if you a rrived by road.
X. H.KE NEDY
Thanks .for your advice, Norman. Your points
llre valid and I wo·u ld certainly advise pilots to
t<J,lk to the CF! at the particular site they
intend to visit, before they set out. The a.rlicle
was i 11te11ded to point out aspects that could
cause difficulties to unwary pilots who had not
previously encountered winch operations.
)
)
0
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Aviation Safety Digest 133 1 i
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Aircraft accident reports
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Readers should note that the information is provided to promote aviation safety it intended to imply blame or liability.
Preliminary data indicate aircraft type and registration, location of accident, date, category of
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Preliminary reports
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The following accidents are still under
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Fixed Wing
Piper PA28·151, VH-BSY, McKinley Qld., 06 Jan. 87,
Instructional - dual.
Shortly after the student had made a normal touchdown, a
sheep ran across the strip in front of the aircraft. The
instructor had not been looking forward, and he was taken
by surprise when the student applied a considerable amount
of nosewheel deflection in an effort to avoid the animal.
The aircraft ran off the side of the strip and struck an
earth run-off water vane.
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Cessna 182-G, VH-DGF, Yatton Qld., 20 Jan. 87,
Non-commercial - pleasure.
The pilot was approaching to land in light crosswind conditions. Turbulence was encountered in the circuit area and
the pilot elected to approach at 80 knots with 20 degrees of
flap selected. After a normal fl are, the aircraft floated for
half t he 610-rnetre strip before touching down. The pilot
applied heavy braking but was unable to stop the aircraft
within t he confines of the strip. Damage was sustained as
the aircraft passed through three drains.
Dear Sir,
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Yours s incerely, ... . ..... . . . .. .... .. . .... . .... .. ... ...... . . ...... ....... .. .
Name: .. .. .. . .... ..... ... .. .... . ....... .... ..... . ... ... . . . .... . . .... . ... .
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Details to be published?
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ii I Aviation Safety Digest 133
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Initials okay
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in no way is
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Cessna 402-B, VH-TLQ, Mt Dianne Qld., 02 Feb. 87,
Charter - passenger operations.
The aircraft was the first of a group of four aircraft being
used to return staff to an alluvial gold mine after a weekend break. It is reported that the weather in the area of the
destination was scattered low cloud on the hills, overcast
and drizzle.
The aircraft was initially held in the area of the Mount
Dianne copper mine, ten kilometres to the south of the
strip, for about six minutes. Two of the surviving passengers reported that the pilot then conducted an approach
straight to the strip. One passenger, who had travelled in
the aircraft previously, stated that the gear was extended
and as t he aircraft became close to the strip, the gear began
striking the tops of trees. The pilot t hen applied power and
the aircraft commenced a steep turn to the left before
impacting the ground in a left-wing, low nose-down attitude. During the turn, the passenger reported hearing a
horn buzzer sound. The aircraft came to rest inverted after
a ground-slide of approximately 46 metres and caught fire.
Cessna A188B·Al, VB-HOP, ThangooI Qld., 21 Feb. 87,
Aerial agriculture.
The pilot was engaged in the spraying of a crop of beans.
After completing several successful spray-runs, the aircraft
struck a power line with the rnaingear. It dived into the
ground in a 60 degree nose-down attitude, nosed over and
slid 73 metres before corning to rest.
Piper PA31, VH-PNL, Cape Flattery Qld., 04 Mar. 87,
Charter - passenger operations.
The aircraft was engaged in the transfer of passengers from
Cape Flattery to Cooktown. It was observed to overshoot
from the first approach and to carry out a low-level circuit
subsequently landing with the gear retracted.
GAF N24·A, VH-FCX, Noosa Qld., 05 Mar. 87,
Non-commercial - pleasure.
A person who previously held a Commercial Pilot Licence
gained entry to the aircraft and was able to start the
engines. The aircraft then apparently rolled forward and
collided with a disused fuel tanker.
At about 0530 hours in the morning the regular pilot
arrived to find the aircraft embedded in the side of the
tanker with the engines still operating at high power. The
person was subsequently located, by police, asleep on the
side of a nearby road.
Beech 95-A55, VH-FDP, Well Close Qld., 11 Mar. 87,
Non-commercial - aerial ambulance.
The pilot had been advised by the property owner to land
on a strip about two kilometres from the homestead instead
of the usual strip. The available length was 1400 metres,
which was adequate for the operation. The pilot reported
that when the aircraft became low during the later stages
of the approach, he applied power, but realised that t he
main wheels would probably pass through tall grass near
the threshold. Just prior to touchdown, the pilot heard and
felt a loud bang. Immediately after touchdown, the aircraft
adopted a left-wing low attitude before the propellers of the
left engine and left wingtip contacted the ground. The aircraft slewed t hrough 90 degrees to the left and ran off the
strip .
An inspection found that the left wheel and oleo leg had
been detached after contact with a mound of dirt seven
metres before the threshold.
Piper PA44-180, VH-K.HG, Herberton Qld., 18 Mar. 87,
Instructional - check.
Shortly after touchdown, the nosewheel struck a
20-centimetre high anthill. The downlock latch on the
nosegear was broken and when the nosewheel entered slight
depression, some 145 metres further along the ground roll,
the nosegear collapsed.
Aviation Safety Digest 133 I iii
�De Havilland DH82-A, VH-CCD, Canberra A.C.T., 08 Jan. 87,
Non-commercial - pleasure.
As the pilot was about to flare the aircraft for landing, a
sheep ran onto the strip. It struck the left landing gear, and
the pilot carried out a go-around. The aircraft continued to
perform normally, and a decision was made to land in the
opposite direction, which gave a distance of about 1000
metres to the body of the sheep. During the landing roll, the
left gear progressively collapsed and the aircraft swung to
the left. The propeller dug into the ground as the aircraft
nosed down before coming to rest in an upright position.
Socata MSTBIO, VH-JTJ, Luddenham N.S.W., 25 Feb. 87,
Instructional - dual.
The student was receiving training in forced landing procedures. The first three exercises were completed without
incident. At the end of the fourth approach to the selected
paddock, the student applied full power and initiated a
climb, intending to return to 3000 feet for a further exercise. However, when the aircraft had reached about 1700
feet, the engine lost power. The instructor took control but
was unable to gain any response from the engine. The a ircraft was landed in a paddock and collided with a fence
some 200 metres from the point of touchdown.
Anvspier Robin, VB-NXY, Wollongong N.S.W., 06 Jan. 87,
Instructional - dual
The student was undertaking his first instructional flight.
At about 2000 feet during the climb towards the training
area, the engine failed completely. A successful forced landing was carried out; however, during the landing roll the
gear struck a number of rocks.
Initial investigation revealed a defect in the fuel cock selector mechanism, in that irrespective of the cockpit indication, the fuel supply cock remained.
Piper PA25-235, VH-BCJ, Wagga N.S.W., 26 Feb. 87,
Non-commercial - business.
When the pilot arrived at his planned destination, he was
unable to obtain a down and locked indication for the
nosewheel. Both normal and emergency means of lowering
the gear were employed, but without success. A diversion
was made to a more suitable aerodrome, where a safe landing was made with t he nosegear retracted.
Rockwell S2R, VH-WBW, Mungindi N.S.W., 06 Feb. 97,
Aerial agriculture.
The pilot had ferried the aircraft to the strip in order to
carry out aerial top-dressing operations. At the conclusion
of the seventh load for the day, the pilot calculated that he
had been operating for a total of about 150 minutes. The
expected endurance of the aircraft was 180 minutes and the
pilot elected to conduct a further short flight to complete
the task. During this flight, the engine stopped suddenly
and the pilot attempted to glide clear of the flooded paddock. The aircraft subsequently stalled and struck an
embankment between the end of the crop and a road on
which the pilot was attempting to land.
Initial inspection revealed that there was v irtually no fuel
remaining in the tank.
Ayres S2R-Tl5, VH-IWI, Boggabri N.S.W., 10 Feb. 87,
Aerial agriculture.
The pilot was engaged on cotton spraying operations. During the second takeoff for the day from this particular
strip, a cow ran in front of the aircraft. The pilot attempted
to fly over the top of the animal; however, the left
maingear struck and killed the cow. The pilot was unable to
maintain control of the aircraft and diverted to a more suita ble aerodrome, where a landing was made without further
damage.
Cessna 172-M, VB-UGK, Bankstown N.S.W., 19 Feb. 87,
Non-commercial - pleasure.
The pilot reported that during the takeoff roll the a ircraft
was slow to accelerate. At about 50 knots, the aircraft
became airborne in a nose-high attitude a nd the pilot
experienced difficulty in lowering the nose. Shortly afterwards the aircraft stalled, the left wing dropped and the
aircraft turned through about 120 degrees before impacting
the ground. It was determined that t he takeoff had been
conducted with the flaps in the fully extended position.
Piper PA30, VH-CON, Bankstown N.S.W., 23 Feb. 87,
Charter - cargo operations.
During a training sequence, the pilot-in-command simulated
a fail ure of the left engine. The pilot under check correctly
identified the failed engine and applied full right rudder to
counter the effects of yaw. The flight then continued normally but the crew was later unable to obtain a down and
locked indication for the landing gear. An inspection from
another aircraft revealed that the gear was only partly
extended, with the nosewheel turned to the right. After all
efforts to lower the gear were unsuccessful, a safe
wheels-up landing was made. It was later discovered that
there was a rigging fault in the rudder system. This had
allowed a roller, which normally engages in a channel to
centre the nosegear during retractions, to move outside the
channel when full right rudder was applied. This resulted
in jamming of the nosegear.
iv I Aviation Safety Digest 133
link pivot bolt was missing. This allowed the lower torque
link to rotate with the wheel and separate from the upper
torque link.
Cessna 180-G, VH-DJS, Albury N.S.W., 20 Mar. 87,
Non-commercial - business.
The pilot was making a landing approach in moderate
crosswind conditions. He commenced the flare at about 15
feet above the runway, with the intention of touching down
in a three-point attitude. The aircraft sank rapidly, touched
down and bounced to about ten feet. The pilot maintained
rearward pressure on the control column but did not apply
power. The nose of the aircraft dropped sharply and the
propeller struck the runway. The aircraft subsequently
overturned, coming to rest on the runway centreline.
Beech 58-TC, VB-FTZ, Tamworth N.S.W., 31 Mar. 87,
Non-commercial - pleasure.
On arrival at the destination aerodrome, the pilot was
unable to obtain a down and locked indication for the landing gear. He noted that when the gear was selected, there
was an abnormal noise and the gear motor only ran for a
few seconds. On a subsequent re-cycling, a down and locked
indication was obtained but the pilot noticed a strong smell
of hydraulic fluid. A diversion to a more suitable aerodrome
was made, where a flypast confirmed that the gear
appeared to be extended. The gear warning horn did not
sound when the throttles were closed. However, the pilot
was unable to move the emergency gear handle from its
stowed position when he decided to use this device to
ensure the gear was in fact down. Shortly after touchdown,
the right main gear collapsed.
Preliminary investigation has revealed that the right
gear-up lock roller was seized, t he relevant gear position
microswitch was incorrectly adjusted, and the manual
extension handle could not be moved because of an
incorrectly fitted trim panel.
Mooney M20..J, VH-IJL, Wee Waa N.S.W., 26 Feb. 87,
Charter - passenger operations.
When preparing for the return leg of a charter flight, the
pilot discovered that the engine starter motor would not
engage. He elected to hand-start the engine, and briefed the
passenger on the operation of the controls. No wheel chocks
were employed. When the engine started, the aircraft commenced to move and the passenger's efforts to control the
aircraft were ineffective. After travelling about 20 metres,
the aircraft ran into a ditch and the engine stopped after
the propeller struck the ground.
Bellanca 8-KCAB, VH-SFK, Schofields N.S.W., 08 Mar. 87,
Non-commercial - pleasure.
The pilot intended to conduct a practice aerobatic flight and
had received a clearance to operate up to 4000 feet in the
local area. Witnesses reported that the aircraft performed a
number of manoeuvres without apparent problem. However,
the aircraft was then seen to descend from a height of
about 1000 feet in a stable but steep nose-down attitude,
t urning to the left. This descent continued unchecked and
the aircraft struck power lines before impacting the ground.
A fierce fire broke out and consumed the wreckage.
Mooney M20..J, VB-UDD, Bankstown N.S.W., 11 Mar. 87,
Instructional - check.
As part of a refresher check on the aircraft, the instructor
required the pilot to use the manual system for lowering
the landing gear. At the end of this procedure, the geardown light did not illuminate and the pilot continued to
rotate the appropriate crank handle. A loud bang was
heard, following which there was little resistance to crank
handle movement. All attempts to obtain a gear-down light
were unsuccessful. Observations made by another aircraft
and persons on the ground indicated that the gear was
down and locked. However, the gear collapsed immediately
after touchdown.
Piper PA32-300, VH-PWD, Coots Crossing N.S.W., 14 Mar.
87, Non-commercial - pleasure.
The aircraft had not been flown for about two months.
Some 20 minutes after departure, the engine commenced to
run roughly and the pilot elected to divert to the nearest
suitable aerodrome. Shortly afterwards, the engine
backfired severely and black smoke entered the cabin
through an air vent. The engine subsequently stopped completely a nd the pilot was committed to a forced landing on
unsuitable terrain. The gear collapsed and the aircraft collided with two fences before coming to rest. On vacating the
aircraft, the pilot discovered that a fire was burning under
the cowls on the right side of the engine. The fire was
extinguished by the pilot and passengers.
Piper PA60-600, VH-NOA, Armidale N.S.W., 17 Mar. 87,
Charter - cargo operations.
Shortly after touchdown, the left wing began to drop and
the aircraft veered off the runway. It came to rest after colliding with a runway light and a culvert. Inspection
revealed that the castellated nut from the left gear torque
{
Cessna U206-A, VH-RPZ, Pakenham Vic., 04 Jan. 87,
Sport parachuting (not associated with an airshow).
The two parachutists were preparing for a jump in which
one pulled the other from the aircraft. During the final
stages of the preparation, the pilot parachute of the front
jumper prematurely deployed. Both persons were ejected
from the aircraft and the leading jumper struck the
tailplane. A portion of the horizontal stabiliser was torn off
and the aircraft pitched down beyond the vertical. The pilot
was unable to regain any control and, with some difficulty,
abandoned the aircraft. He deployed his parachute at about
500 feet above the ground and landed safely. The parachutist who had struck the tailplane was initially rendered
unconscious and had suffered a broken right arm. She
recovered sufficiently to deploy her parachute and control
her descent when close to the ground. The aircraft was
destroyed when it impacted the ground in a steep nosedown attitude at high speed.
Piper PA34-200T, VB-STT, Latrobe Valley Vic., 14 Jan. 87,
Non-commercial - business.
The pilot was approaching to land in what he believed were
light wind conditions. As he crossed the threshold, he
realised that there was a tailwind component, but he
elected to continue the approach. Touchdown occurred with
about 415 metres of the strip remaining. During the landing
roll, the pilot became concerned that the aircraft would not
stop before the boundary fence, and a ground loop was
attempted. The maingear collapsed as the aircraft came to
rest 103 metres before the fence. The landing attempt had
been made in 12 to 10 knot downwind conditions.
Cessna A188B-Al, VH-UDV, Toora Vic., 20 Jan. 87, Ferry.
The pilot had landed at the one-way agricultural strip in
order to deliver covers for a load of superphosphate. The
subsequent takeoff was normal until the point where the
tail of t he aircraft was raised. At this point, the aircraft
was affected by a strong wind gust and the pilot was
unable to maintain directional control. The aircraft ran off
the side of the strip and struck scrub and a steel fence post.
The wind at the time was relatively strong, giving a substantial downwind/crosswind component.
Siai Mar F260, VH-ARU, Yabba North Vic., 24 Jan. 87,
Non-commercial - pleasure.
At a height of about 100 feet after takeoff, the engine
faltered briefly. It then returned to full power, but the pilot
decided to conduct a low-level circuit and land in order to
investigate the apparent anomaly. On the downwipd leg, the
engine stopped and the pilot was committed to a wheels-up
landing in a paddock. Shortly before touchdown, engine
power was regained and the propeller contacted the ground
under almost full power. The pilot later advised t hat he had
inadvertently selected an almost empty fuel tank prior to
takeoff. He had not checked the fuel selector when the firs t
loss of power was noticed because he had been convinced
that he had selected the correct tank.
Cessna 170-B, VB-BUX, Ballarat Vic., 07 Feb. 87,
Instructional - check.
The pilot arranged for a checkflight in the aircraft, as it
was a type he had not flown for some time. The instructor
commented that as the pilot made rudder corrections during
the takeoff roll, he also inadvertently applied light braking.
After a period of general flying, the aircraft was returned
to the circuit for a landing in moderate crosswind conditions. Touchdown was made in a three-point attitude but
shortly afterwards the aircraft commenced to swing to the
right. Corrective measures by both pilots were unable to
arrest the swing and the left gear subsequently collapsed.
The pilot had used left aileron and right rudder inputs to
align the aircraft at touchdown, and had possibly inadvertently applied braking to the right mainwheel.
Cessna 172-B, VB-KWV, Fyansford Vic., 15 Mar. 87,
Instructional - solo (supervised).
The pilot was undertaking a solo navigation exercise prior
to a flight test for the removal of area restrictions on his
licence. About 20 minutes after departure, the engine commenced to run roughly and the pilot diverted toward a suitable aerodrome. However, the engine performance
deteriorated and the pilot elected to carry out a precautionary landing in a paddock. Towards the end of the landing
roll the aircraft collided with a fence. Initial investigation
revealed a broken rocker arm on one of the engine
cylinders.
Piper PA28-140, VH-PBR, Swan Hill Vic., 31 Mar. 87,
Instructional - dual.
The student was being instructed in crosswind techniques
and several circuits and landings had been completed without incident. On the final circuit a normal approach and
touchdown were made, but during the landing roll the right
wing lowered and the aircraft swung through 90 degrees.
Initial inspection revealed that the lower torque link bolt on
the right gear had failed, allowing the wheel assembly to
detach.
Cessna 210-N, VB-UFA, Numbulwar N.T., 08 Feb. 87,
Charter - passenger operations.
The aircraft was to be ferried out of the path of an
approaching cyclone. Shortly after takeoff, the pilot heard
a loud noise and the engine began to vibrate violently. The
pilot turned the aircraft towards the only available area
and transmitted a 'Mayday' call. During the turn, oil began
to stream over the windscreen from the rear of the engine.
The area selected for landing was about 600 metres long
and surrounded by low trees. The approach was high and
fast and the aircraft was still airborne as it approached the
end of the area. The pilot elected to stall the aircraft into
the trees.
Cessna 172-D, VB-DEN, Pine Creek N.T., 14 Mar. 87, Ferry.
At about 500 feet above ground level after takeoff, just
after the pilot commenced a left t urn, the engine lost power.
The pilot was unable to rectify the problem and chose a
cleared area in which to land. During the approach, it
became obvious to the pilot that the aircraft would not
make the selected area, so he decided to land on a bush
track. The aircraft touched down on the nosewheel and
bounced, then touched down again before running through
thick grass, coming to rest 74 metres beyond the second
point of touchdown. A fire then broke out in the engine
compartment which subsequently destroyed the aircraft.
Aviation Safety Digest 133 Iv
�Cessna Al85-E, VH-KPF, Meekathara W.A., 10 Jan. 87,
Non-commercial - company flight.
When the pilot arrived at the destination, he noted that the
wind direction indicator showed apparently calm conditions. Almost immediately after touchdown, the aircraft
began to swing to the right. Attempts to correct the swing
were unsuccessful and the left gear leg collapsed. After
vacating the aircraft, the pilot noticed that t here had been
a quartering tailwind of about ten knots during the landing.
De Havilland 82-A, VB-FAS, Jandakot W.A., 31 Jan. 87,
Non-commercial - pleasure.
As the aircraft was executing a stall turn, the pilot noticed
that the engine and propeller had stopped. He attempted to
restart the engine by diving the aircraft. However, the
engine had not restarted by the time the aircraft reached
2000 feet above ground level and the pilot decided to land
the aircraft in an open area. During the approach, the pilot
realised that t he selected landing area was unsuitable, so he
chose another area. As the aircraft approached t he new
area, it struck trees and came to rest among the trees prior
to that area.
Cessna 182-P, VB-MOO, Albany W.A., 07 Feb. 87,
Non-commercial - pleasure.
In the course of a daily inspection, a LAME discovered that
the aircraft had sustained damage to the nosewheel support
structure a nd the firewall. It was evident that the damage
had occurred as a result of a heavy landing. The last pilot
to fly the aircraft reported t hat after making an enroute
landing, he had noted that the nosewheel oleo was flat.
After seeking advice from the aircraft operator, he had
flown the aircraft to its home base. It was possible t hat the
damage had occurred during the enroute landing.
Piper PA31-Al, VB-HFD, Cervantes W.A., 20 Feb. 87,
Non-commercial - aerial ambulance.
The aircraft was carrying out a night flight to a strip lit by
portable fluorescent lights. These lights were spaced 190
metres apart along the length of the strip. During the
approach, the left maingear struck rising ground which
formed the end of t he built-up strip surface approximately
29 metres short of the threshold. The gear was bent rearward but did not collapse, and the landing was completed
without further incident.
Rotary Wing
Hiller 12E, VH-HJW, Ayr Qld., 23 Jan. 87, Aerial
agriculture.
The pilot reported t hat the engine lost power while the aircraft was flying at a height of 30 feet above the ground.
The subsequent forced landing was made onto newly cultivated ground and all four skid legs were bent.
Bell 47-G2, VB-RFY, Maroochydore Qld., 25 Jan. 87,
Charter - passenger operations.
The helicopter was being flown along a beach at 500 feet
above ground level when the engine lost power without
warning. The pilot turned the aircraft into wind and carried
out an autorotation. The subsequent landing was heavy, in
soft, uneven sand. Both occupants evacuated the helicopter
while the rotor blades were still turning. The pilot stated
t hat as he was a bout to return to the helicopter and turn
off the fuel and switches, the right skid broke t hrough the
sand and the helicopter lurched to the right rear, causing
the ma in rotor blade to sever the tail boom.
Hiller UH12-E, VH-HJW, St. Pauls Stn. Qld., 27 Feb. 87,
Ferry.
During the descent the pilot heard a loud bang, following
which the engine stopped. An autorotational descent was
carried out for a landing onto the clearest avaialble area a dry river bed. The helicopter touched down with some
forward speed on the soft sand, pitched forward and rolled
over.
An inspection of the wreckage revealed t hat a connecting
rod big-end had failed.
vi I Aviation Safety Digest 133
Hughes 269-C, VH-PHK, Atherton Qld., 25 Mar. 87,
Non-commercial - pleasure.
On the previous day, the pilot had ferried the aircraft to a
maintenance organisation for a scheduled servicing. No
abnormalities were discovered and a satisfactory engine run
was carried out by the pilot prior to departure for the
return flight. A search was commenced when the helicopter
did not arrive at the destination, and the wreckage of the
a ircraft was located when a VSB signal was heard. The aircraft was lodged in the branches of a tree some 18 metres
above ground level. The tail boom was lying near the base
of the tree and most components had received severe
impact damage. Init ial examination of the wreckage
revealed substantial internal engine damage.
Schemp Std. Cirrus, VH-IIZ, Geelong Vic., 23 Feb. 87, Air
show/ air racing/air trials.
The pilot, who was an experienced glider pilot and
instructor, was taking part in a gliding competition. Only
two of the 12 competitors were able to complete the exercise, the remainder being required to outland. Almost four
hours after being launched, the aircraft was sighted in a
right-hand circling descent, apparently being manoeuvred
for an outlanding. At low level, the angle of bank was seen
to s uddenly increase and the nose dropped. The right wing
struck the ground and the aircraft cartwheeled before
coming to rest 22 metres from the point of initial impact.
a
Shemp Ventus A, VB-FQS, Benalla Vic., 12 Jan. 87,
Air show/air racing/air trials.
Schleicher ASW20, VH-KYF, Benalla Vic., 12 Jan. 87,
Air show/air racing/ air trials.
A large group of pilots were practising for the forthcoming
World Gliding Championships. There were a number of
weak therma ls in the area near the starting gate position,
and there were several gliders in each terminal. The pilot of
VH-FQS encountered a surge of lift and commenced to
increase the angle of bank and pull-up, achieving a climb
rate of about six knots. Shortly afterwards, the canopy of
this aircraft struck the wing of VH-KYF which was at a
climb rate of about four knots. The canopy was shattered
and the left flap of VH-KYF was broken in half. The pilots
maintained control of their aircraft and subsequently
landed safely.
Bell 47G2, VH-KHK, Balranald N.S.W., 10 Mar. 87,
Non-commercial - aerial application/survey.
The pilot reported that as he brought the aircraft into the
hover in preparation for landing, it sank to the ground from
a height of about ten feet. The tailrotor blades struck a
lygnum bush and the drive shaft sheared. The pilot indicated that the main rotor rpm had decayed, possibly from
over-pitching during the latter stages of the approach.
Hiller UH12-E, VB-ECK, Tamworth N.S.W., 18 Mar. 87,
Charter - cargo operations.
The pilot had been carrying out crop spraying operat ions
and was hurrying to return to his base before last light. He
was concerned with the fuel state and made an enroute
landing, where one of the passengers dipped the tank.
Believing that adequate fuel remained, the pilot took off
again but shortly afterwards the engine lost all power. During the subsequent autorotation, manoeuvring was necessary to avoid power lines. The helicopter then landed
heavily and the main rotor blades struck and severed the
tail boom. It was determined that at the time of the accident, the aircraft had been operating for seven minutes
longer than the expected endurance.
Hiller UH-12E, VH-MJV, Darwin N.T., 11 Mar. 87,
Non-commercial - aerial mustering.
The pilot was direct ing cattle through a gate when a cow
t urned and began to walk back towards the helicopter. It
stopped in front of the aircraft before charging. The pilot
applied back-cyclic and up-collective in an attempt to avoid
the animal but the tail rotor struck the ground. The helicopter began to yaw and the pilot landed the aircraft immediately. It continued to yaw after t he landing and the landing
skid assembly was substantially damaged .
Schleicher K7, VH-GNX, Woodvale Vic., 24 Jan. 87,
Non-commercial - pleasure.
The pilot had conducted a soaring flight for an hour in particularly turbulent conditions. The subsequent landing was
conducted with a light crosswind from the right. The pilot
misjudged the flare and the aircraft ballooned to a height of
about 15 feet while veering to the left. The pilot then
retracted the a ir brakes, and the glider probably stalled
before impacting the ground heavily.
)J
Schneider ES-60B, VH-GYT, Oatlands Tas., 21 Mar. 87,
Non-commercial - pleasure.
The pilot was conducting a soaring flight when deteriorating lift conditions made an outlanding necessary. A paddock
was chosen and the pilot carried out a standard approach
pattern, a iming to land into wind. He noted a powerline
pole on a hill some 500 metres away but could not see any
other poles near the intended landing area. However, as he
was about to turn onto final approach, he noticed a single
power line d irectly ahead of the aircraft. There was insufficient time available to take any avoiding action and the
wire struck the aircraft canopy. The aircraft subsequently
impacted the ground and cartwheeled to a stop 87 metres
beyond the point of collision with the wire. Initial investigation revealed that the supporting poles for the power line
were one kilometre apart.
Hughes 269-C, VH-THQ, Alroy Downs N.T., 17 Mar. 87,
Aerial mustering
The pilot was chasing a calf that had broken away from t he
main herd. When the animal turned towards the helicopter,
the pilot attempted to take evasive action. The pilot felt the
aircraft rock, and believing that it had been struck by the
animal, he pulled it up to about 40 feet above the ground.
The aircraft began to yaw. During the subsequent landing,
while still yawing, the landing skids collapsed.
i
Gliders
Entwicklung Phoebus, VH-GYC, Maryborough Qld., 14
Jan. 87, Non-commercial - pleasure.
The pilot was returning to land after a period of thermalling flight when severe turbulence was encountered. The
pilot's head hit and broke the canopy and he then had problems with his vision. Heavy sink was a lso experienced and
an outlanding was attempted in a canefield. The area selected was a five-metre wide strip between ar eas of cane
growing to about l.7 metres in height. The left wing caught
in the cane and the aircraft s lewed violently before coming
to rest with the wing completely torn out of the fuselage.
Schemp Std. Cirrus, VH-GGC, Kingaroy Qld., 24 Jan. 87,
Non-commercial - pleasure.
During the approach, the pilot became aware that the a ircraft was going to undershoot the intended landing area. He
adjusted the approach; however, the aircraft la nded short
of the aerodrome in a cultivated field and struck an earth bank.
'
0
(j
Glasflugel 206 Hornet, VB·GMU, Saddleworth S.A., 30
Jan. 87, Non-commercial - pleasure.
The pilot was attempting a 300 km cross-country flight.
After release from the aerotow, the glider gained altitude
s lowly, obtaining only 3000 feet above mean sea level. As
the flight continued, the glider did not gain any further altitude and the pilot decided to carry out an outlanding. While
the glider was being manoeuvred in the circuit at about 50
feet above ground level, the right wing dropped and struck
the ground .
Burkhart Astir CS, VH-GDZ, BondSpringsN.T.,01Feb.87,
Non-commercial - pleasure.
The pilot was carrying out local glid ing in the Bond Springs
area attempting to achieve a flight time of five hours. He
had flown away from the vicinity of the airfield in search
of lift. On returning to the airfield, he became aware that
he would be unable to reach the airfield and selected the
only suitable area to carry out a landing. The aircraft failed
to make the selected area and struck a tree during the
approach, subsequently impacting t he ground on t he right
wing and slewing through 180 degrees before coming to rest.
Glasflugel Libelle H201, VH-GYQ, Bond Springs N.T., 08
Feb. 87, Air show/air racing/ air trials.
While returning to the airfield, the glider experienced a
deterioration of lift and the pilot decided to carry out a
landing on the Stuart Highway. The pilot observed two
vehicles on the road and attempted to warn them of intention to land. One vehicle stopped but a bus continued a long
the roadway. The pilot decided to land before reaching the
bus. After touchdown, t he pilot moved the glider to the side
of the road but the left wing struck a tree, t hen a road sign.
The glider slewed off the road and the landing gear was
torn off.
Burkhart Twin Astir, VH-IKU, Waikerie S.A., 25 Mar. 87,
Instructional - solo (supervised).
The pilot had completed a soaring flight of some two and a
half hours duration. The aircraft was seen to make an
apparently normal approach but during the landing flare,
the tail cone contacted the ground and the glider pitched
nose down. The forward fuselage area then struck the
ground heavily. The glider received only minor damage;
however, the pilot suffered serious back injuries.
Ultralights
Sadler Vampire SV2, N/ A, Wilton N.S. W ., 17 Feb. 87, Test.
The pilot was completing a 50-hour test flying program on
the aircraft. Two previous sorties had been flown during
the day , without incident. On this occasion, the pilot was
conducting a glide approach, but when the power was
re-applied to go around, the engine delivered some 400 rpm
less than normal. The pilot attempted to conduct a circuit;
however, the engine power continued to decay. The turn
onto base leg was conducted at about 100 feet, and shortly
afterwards all power was lost. The aircraft had been close
to stalling speed, and landed heavily in a paddock.
Firebird Ml, N/ A, Judbury Tas., 07 Feb. 87,
Non-commercial - pleasure.
The aircraft was the only known one of its type in the
country and had been imported by the pilot in 1982. It had
not been flown since April 1984. The pilot intended to fer ry
the aircraft to a neighbouring strip, but about seven minutes after depart ure the a ircraft was seen to turn back.
Approaching the departure point, the aircraft suddenly
pitched up, and shortly afterwards the left wing failed. The
pilot attempted to use the recovery parachute, but this
became entangled in the rotating propeller and t he aircraft
fell to the ground.
Gemini Thruster, N/ A, Kapunda S.A., 31 Jan. 87,
Non-commercial - pleasure.
The pilot was carrying out a cross-country flight. After
passing over one of his planned turning points, he became
concerned about the aircraft's location and decided to follow a road back towards the destination. Enroute the pilot
descended the aircraft to read a road sign in an endeavour
to establish his location. However, the aircraft struck a
power line and subsequently collided with the ground.
Final reports
The investigation of the following
accidents has been completed
Fixed Wing
Cessna 172, VH-RDP, Quilpie Qld., 24 Jan. 87,
Non-commercial - pleasure, PPL. 118 hrs.
The aircraft had been flown from an a djoining property by
the owner. Because of difficulties encountered in starting
the engine, the owner left it running while the pilot for this
flight took his seat. At the t ime, weather condit io ns were
hot, w ith a shade temperature of 46 degrees Celsius, and
with little wind. The pilot subsequently a dvised that during
takeoff, a steeper than normal nose-high attitude was
adopted and the aircraft stalled from a height of about 20
feet above the ground.
Aviation Safety Digest 133 I vii
�The particular aircraft was an early model of the type, with
a different instrument panel layout, instrument coarning
shape and height to that which the pilot had been operating
during the preceding month. The pilot believed that the attitude selected after liftoff was the appropriate one, but
because of the difference in instrument coaming heights,
the actual attitude was too steep. The departure had been
hurried and the pilot had not familiarised himself with the
layout of the instrument panel. The extreme ambient temperature had probably caused a degradation in the pilot's
performance.
Cessna 172-F, VH-DFW, Musgrave Stn. Qld., 13 Mar. 87,
Non-commercial - pleasure, PPL/Cl. 1, 630 hrs.
The pilot was aware that there was an area of soft ground
on the strip. The area was marked by a cone marker which
was about 10 metres in from the edge of the strip. The pilot
intended to land some 100 metres beyond the cone; however, turbulence and strong sink was encountered during
the latter stages of the approach. As the aircraft touched
down, the tailplane struck the cone marker which was made
of galvanised iron.
This accident was not subject to an on-site investigation.
Piper PA28-R200, VH-SVX, Coffs Harbour N.S.W., 16 Jan.
87, Non-commercial - pleasure, PPL, 160 hrs.
About five minutes after takeoff for a sightseeing flight,
the latches on the cabin door released and the door partially opened. The pilot was distracted by the resulting
airflow noise and was concerned that the door may have
opened further. An immediate return was made to the
departure point but the pilot then forgot to lower the landing gear before touchdown.
The subsequent investigation revealed that the top-door
latch had probably not been correctly secured before departure. The pilot had not checked the security of the door but
had asked his passenger to make sure the door was closed.
The main latch was found to be out of adjustment, such
that a firm push could cause the door to spring open.
The pilot had not previously experienced a door-open in
flight situation. He had been unduly anxious to land and
had not completed the prelanding checks. The noise of the
airflow past the door had masked the sound of the gear
warning horn. The aircraft is equipped with an automatic
gear lowering system; however, the handle for this system
was in the manual override position.
This accident was not subject to an on-site investigation.
Piper PA28-180, VH-NBF, Bankstown N.S.W., 06 Feb. 87,
Non-commercial - pleasure, PPL, 350 hrs.
The pilot had hired the aircraft in order to maintain currency on the type. After an uneventful flight in the training
area, he returned to the circuit and carried out a normal
approach. However, shortly after touchdown the aircraft
swerved to the left and the pilot was unable to regain directional control. The aircraft ran off the side of the runway
and the nosegear collapsed.
It was discovered that the elevator trim had been set
almost fully nose down and the rudder trim was set almost
fully nose left at the time of the accident. The nosewheel
had contacted the runway at about the same time as the
mainwheels and it was likely that the subsequent loss of
control was the result of the aircraft 'wheelbarrowing' on
the nosewheel. The pilot, who had only limited experience
on the type, had believed that the aircraft had been correctly trimmed prior to touchdown.
Cessna Al88B-Al, VH-UDV, Nar Nar Goon, 10 Jan. 87,
Aerial agriculture, CPL/ Ag. Cl. 1, 2500 hrs.
The pilot had been carrying out spraying operations for
most of the day. The flight in question was to be the first
for the day from this particular strip. The pilot had
pumped 644 litres of water-based spray into the hopper,
having previously carried this size load from the 604-metre
strip. Normal takeoff procedures were employed; however,
the aircraft failed to become airborne as expected. Almost
immediately after liftoff, the left gear leg struck and severed the top wire of a fence. The left flap, horizontal stabiliser and elevator collided with a fence post. The pilot was
able to retain control of the aircraft, dumped the load and
returned for a successful landing on the strip.
viii I Aviation Safety Digest 133
Although the pilot had previously operated with a waterbased spray-load of 644 litres from this strip, he had overlooked the fact that the loads had different specific
gravities. On this occasion, the specific gravity of the load
was significantly higher and resulted in the aircraft being
about 190 kilograms above the gross weight permitted for
agricultural operations. Under the conditions, there had
been insufficient strip length available to permit a safe
takeoff.
Cessna 152, VH-IBL, Shepparton Vic., 18 Jan. 87,
Instructional - solo (supervised), Student, 23 hrs.
The pilot was conducting practice forced landings in the
training area. When overshooting from one of these
approaches, he observed that the flap would not retract
from the two stages-down position. After advising the flying club by radio of the problem, the pilot returned for a
landing. The aircraft bounced on touchdown and then began
to porpoise. The nosewheel was dislodged and the aircraft
slewed off the runway before nosing over onto its back.
The flaps had failed to retract because of a faulty microswitch. The pilot had not experienced a malfunction of this
nature before and had allowed this to distract him from the
operation of the aircraft. He had persevered with the landing after the initial bounce but had not been able to exercise adequate pitch control.
Cessna 152-M, VH-WLA, Geelong Vic:, 30 Jan. 87,
Instructional - solo (supervised), Student, ·18 hrs.
The student lost directional control of the aircraft during a
touch-and-go landing in moderate crosswind conditions. The
aircraft ran off the runway and collided with the aerodrome boundary fence.
The student had only limited experience in handling the aircraft in crosswind conditions. The accident occurred during
the first landing of the practice session.
Cessna 172N, VH-BAC, Cox Bight Tas., 02 Feb. 87,
Non-commercial - pleasure, PPL, 132 hrs.
Before commencing a fishing expedition, the pilot had
determined that a particular section of beach was frequently used by light aircraft. An uneventful landing was
made on the beach and later the pilot made a takeoff and
circuit of the area before landing on another section of the
same beach. The group had no success with their fishing
and the pilot decided to fly to another beach on the
opposite side of the bight. During the landing roll, the pilot
discovered that the left brake was not operating. The aircraft subsequently ran through a shallow-water run,
entered an area of soft sand, and overturned.
The pilot had no previous experience in operations from
beaches and the operator of the aircraft was not aware that
a beach landing was intended. The section selected was not
used by other pilots who operated in the area. The reason
for the brake failure was not determined; however, the left
brake unit had a recent history of malfunctions, possibly
related to defective seals.
This accident was not subject to an on-site investigation.
Cessna 182-Q, VH-BXL, Numbulwar N.T., 31 Jan. 87,
Charter - passenger operations, CPL/Cl. 4, 417 hrs.
The pilot was conducting the return leg of a charter flight
when weather conditions deteriorated abou t 130 kilometres
from the destination. Thunderstorms were evident on either
side of track and converging ahead of the aircraft. The pilot
elected to return to the departure aerodrome; however,
approaching this strip the weather again deteriorated to the
point w here flight in visual conditions was not possible.
After searching for over an hour to find a clear route to
another aerodrome, the pilot elected to land in what
appeared to be a suitable paddock. During the landing roll,
the nosewheel sank into the soft surface and the nosegear
was dislodged.
The pilot had only limited experience in operating in the
Northern Territory during the wet season and had probably
not received sufficient training and supervision from the
aircraft operator.
This accident was not subject to an on-site investigation.
Gliders
Aer-pagaso M-lOOs, VH-HDJ, Waikerie S.A., 02 Feb. 87,
Air show/air racing/ air trials, Glider, 112 hrs.
The glider was being launched via an aero-tow. It became
a irborne after a short ground run and climbed to a higher
than normal altitude. The pilot attempted to correct the
situation
the glider bounced twice on t he strip, breaking
off _the tail skid. As the glider climbed away, it continued to
oscillate in a position above the tug aircraft. The tow rope
was released when the glider was about 120 feet above
ground level and the pilot, believing t hat t here was insufficient runway remaining to land, attempted to t urn back
for a landing on the strip. During the turn t he glider
entered a spin, subsequently striking the ground in a noselow attitude.
The pilot was inexperienced on t he aircraft t ype, having
not flown the type for about two months. On the day, there
was a gusty wind blowing and it was the opinion of experienced local pilots that a landing straight ahead after rope
release would have been possible.
?ut
Schemp Discus A, Unknown, Deniliquin N.S. W., 29 Jan. 87,
Air show/air racing/air trials, Glider, 4000 hrs.
Schemp Discus A, VH-GSO, Deniliquin N.S.W., 29 Jan. 87,
Air show/air racing/air trials, Glider, 3620 hrs.
The pilots were competing in a race as part of the World
Gliding Championships. The gliders were in a group climbing in a thermal when they collided at about 3900 feet
above mean sea level. The Italian pilot in LB did not see the
other aircraft, while the Polish pilot of VH-GSO only
became aware of the proximity of LB at the last moment.
The collision severed the right half of the horizontal stabiliser of LB; however, the pilot was able to retain control of
the aircraft and landed without further damage.
This accident was regarded as an operational hazard
inherent in this type of competition, and was not subject to
an on-site investigation.
Glasflugel Libelle, VH·GBN, Bathurst N.S.W., 25 Jan. 87,
Non-commercial - pleasure, Glider, 130 hrs.
T~e pilot was approaching to land at the end of a soaring
fhght. There was t urbulence in the circuit area with a moderate crosswind for the landing direction. The pilot realised
he was overshooting his planned touchdown point, and sideslipped the glider to lose height. At the conclusion of this
manoeuvre the glider was some 1000 feet in from the
threshold. It then landed heavily and bounced, before a second heavy touchdown occurred.
The pilot had evidently been distracted by the presence of
another glider and a tug aircraft at the strip threshold, and
probably by the wind strength and turbulence.
Schemp Nimbus 2, VH-WVY, Coleambally N.S.W., 16 Feb. 87,
Non-commercial - pleasure, Glider, 278 hrs.
While conducting a cross-country flight, the pilot encountered deteriorating lift conditions, and an outlanding
became necessary. On short final approach to the selected
paddock, strong lift was experienced and the pilot overshot
the touchdown point. During manoeuvring for another
approach, the glider stalled and struck the ground in a very
steep nose-down attitude.
When it was apparent that the aircraft would overshoot the
target touchdown point, t he pilot had carried out a steep
turn to re-position for final approach. During t his
manoeuvre the spoilers, flaps and landing gear had been
left extended. The pilot ha,d evidently not monitored the
airspeed and the glider had stalled and entered an incipient
spin.
Std Jantar-3, VH-HNG, Horsham Vic., 14 Feb. 87,
Air shoe/ air racing/ air trials, Glider, 345 hrs.
The pilot was conducting the last leg of a competition flight
when he realised that an outlanding would probably be
necessary. However, he was able t o reach a point about
three kilometres from the destination aerodrome and while
manoeuvring towards the selected paddock he c~nsidered
he could in fact reach the aerodrome. The planned
outlanding attempt was abandoned, but approaching the
aerodrome boundary the pilot realised he was too low and
decided to land in a s tubble paddock. During the turn onto
final approach, the left wingtip contacted the stubble and
the glider struck the ground heavily.
The pilot had delayed making an outlanding because of his
desire to complete the competition. Wind conditions were
calm and the pilot could have conducted a straight-in
approach to the stubble paddock thus avoiding a turn at
very low height above the ground. The pilot had been
airborne for nearly five hours and it was possible that he
was affected by fatigue.
This accident was not subject to an on-site investigation.
Schneider ES-60, VH-GQW, Euroa Vic., 19 Feb. 87,
Non-commercial - pleasure, Glider, 1188 hrs.
The glider was winch launched to a height of 900 feet
above the ground. The pilot was unable to find any strong
lift and when the glider had descended to 600 feet, the pilot
rejoined the circuit for landing. Some sink was experienced
on the downwind leg and the glider was only about 200 feet
above the ground when t he base t urn was made. During the
turn onto final approach, the right wing of t he glider struck
the ground. The aircraft swung sharply to the right and
subsequently landed heavily.
There was no other t raffic in the area and the pilot could
have modified his circuit and landed on a cross-strip. It was
likely t hat he had attempted to land the aircraft close to
the winch launch cable to facilitate the next flight.
Ultralights
Thruster Gemini, N/ A, Goulburn N.S.W., 01 Feb. 87,
Non-commercial - pleasure, N/ A.
The pilot held a Student Licence as issued by the AUF. During a landing approach the aircraft overshot the intended
touchdown point. It subsequently ran off the end of the
strip and collided with a t ree.
It was reported that the student was not being supervised
by an instructor at the time of t he accident. The reason he
apparently misjudged the approach was not determined.
The accident was not subject to an on-site investigation.
Sorrell Hyperlight, N/ A, Oxley Island N.S.W., 25 Feb. 87,
Non-commercial - pleasure, N/ A, 6500 hrs .
During a flight earlier in the day, the pilot noted that an
airspeed indicator he had fitted was not operating. This had
been of no concern, as the original indicator fitted to the
aircraft was functioning correctly. After landing and rectifying the defect in the new indicator , t he pilot elected to
carry out a further short flight. At about 200 feet after
takeoff the engine failed and while attempting to restore
power, the pilot forgot t o monitor the airspeed. The aircraft
stalled at a height of about 100 feet and the pilot w as only
able t o regain partial control before the aircraft stuck the
ground heavily .
The reason for the loss of engine power has not been
established.
This accident was not subject to an on-site investigation.
Final updates
The investigation of the following
accidents has been completed. The
information is additional to or replaces that
previously printed in the preliminary report
Fixed Wing
Piper PA31, VH-CJB, Cairns Qld., 02 Sep. 86, CPL/ Cl. 1,
895 hrs.
The pilot hired t he aircraft privately from his employer to
conduct a holiday flight during his leave. The j ourney commenced at Moorabbin on 25 August and the aircraft arrived
at Cairns about midday 30 August, after stopovers at
Coolangatta and Proserpine. The pilot and his passengers
then spent the next t hree days at leisure in the Cairns area.
Aviation Safety Digest 133 I ix
�On the day of the accident, the pilot attended the Cairns
Briefing Office where he collected the relevant weather
forecasts and submitted a flight plan. The flight plan indicated that the flight would be conducted in accordance with
Instrument Flight Rules. It contained a deficiency in that no
details were given for the first route segment from Cairns
to Biboohra. It is apparent that the pilot had not noticed
that the tracks to the west of Cairns, on the relevant
enroute chart, emanate from Biboohra, and not Cairns.
There was no track line which joined Cairns and Biboohra.
Such a line might have alerted the pilot at the time he
planned the flight. The error in the flight plan was not
detected when the plan was submitted.
When the pilot was issued with an airways clearance prior
to departure, it was apparent that he did not understand
the terms of the clearance, which gave the initial tracking
point as Biboohra. The location of this point was explained
to the pilot and he subsequently accepted the clearance. He
elected to depart using visual procedures, after being
offered a choice of these or the published Standard Instrument Departure profile. A visual departure from the particular runway in use allows an aircraft proceeding towards
Biboohra to intercept the required track sooner than is
possible with an instrument departure.
The aircraft was issued with takeoff instructions which
included clearance for the pilot to a right turn after
takeoff. Witnesses observed that the aircraft complied with
this clearance and headed in a south-westerly direction
before turning to the north-west and subsequently entering
cloud. The cloud base was estimated to be between 2000
and 2500 feet above mean sea level. No further communications were received from the aircraft and a search was
commenced that afternoon. The search effort was hampered
by the weather and the wreckage was not located until the
following afternoon.
Inspection of the wreckage indicated that the aircraft
struck the top of a ridge line 250 metres south-west of the
highest point of the Mt Williams area. At the time, the aircraft was on a west-north-westerly heading, flying wings
level and climbing at an angle of about five degrees. No
fault was found with the aircraft that could have contributed to the occurrence.
At the time the aircraft entered cloud, the pilot should have
reverted to Instrument Flight Rules procedures. To comply
with these procedures, a pilot is required, inter alia, to
ensure that adequate terrain clearance is achieved during
climb to the lowest safe altitude. The relevant altitude for
the route segment Cairns to Biboohra is 4500 feet above
mean sea level (amsl). As the aircraft was apparently under
control at the time of impact, with the ground at about
3250 feet amsl, it was likely that the pilot had overlooked
the lowest safe altitude requirements.
De Havilland C2, VH-IDG, Cooma N.S.W., 09 May 86,
CPL/Ag. Cl. 1, 17 OOO hrs.
During the takeoff roll, the left mainwheel struck a tyre
which was being used as a strip marker. The tyre deflected
into the tailplane; however, the pilot did not feel the impact
and discovered the damage at the conclusion of the flight.
An inspection indicated that the tyre had been moved from
its normal pos ition prior to the impact and was hidden from
the pilot's view by the long grass on the strip.
This accident was not subject to an on-site investigation.
Cessna 310-B/Al, VH-1TM, Bankstown N.S.W., 26 Aug.
86, CPL/Cl. 1, 349 hrs.
The purpose of t he flight was to deliver the aircraft to its
new owner. The aircraft had been imported from Papua
New Guinea in December 1985 and had flown only a limited
amount since that time. The pilot carried out three circuits
prior to departure and made a successful landing enroute
for refuelling. However, on touchdown at Bankstown following a normal approach, the nosegear collapsed. Initia l
investigation revealed that the nosegear-down lock h ad not
completed its travel to the overcentre position. In addition,
the microswitch was incorrectly adjusted, giving a down
and locked indication before the lock was fully engaged.
The nosegear had collapsed because of faulty rigging on the
gear, which prevented it from completing the full extension
x I Aviation Safety Digest 133
cycle. The applied loads had been held by the actuating
rods and bellcranks until a bellcrank rod-end had failed in
overload.
Cessna 150-E, VH-KML, Tundulya N.S.W., 25 Nov. 86,
PPL, 300 hrs.
The pilot had been carrying out a number of flights to
strips in the general area. After completing repairs to a
bore pump, the pilot and passenger prepared to return to
the property homestead, some 20 kilometres to the north.
Shortly after the takeoff roll commenced, the aircraft began
to veer to the right. Full left rudder was progressively
applied, but directional control could not be maintained.
The right wing collided with a number of bushes and saplings alongside the strip. The aircraft then slewed rapidly to
the right and the nosegear collapsed.
Investigation revealed that the aircraft had rolled for 104
metres before the right wing struck and broke a small sapling. This coincided with the initial veer to the right as
reported by the pilot. As the aircraft diverged from the
centre of the strip, it entered an area of soft loam which
increased the drag on the right wheel. The scrub struck by
the aircraft had encroached onto the strip, reducing the
width in places to about 15 metres. The pilot had been
aware that the strip had not been cleared of undergrowth
for some 21 months.
Piper PA23·250, VH-MBU, Essendon Vic., 29 May 86, CPL/
Flt. Inst. Gr. 3, 610 hrs.
.
The pilot was carrying out a preflight inspection of the aircraft in preparation for an Instrument Rating flight test. He
had selected the flaps down and began operating the
hydraulic hand pump to extend the flaps. After a few pump
cycles, the right maingear collapsed and the pilot then
noted that the gear selector was in the up position.
It was suspected that the anti-retraction valve, which is
designed to prevent gear retraction on the ground, was
unserviceable. However, no fault was discovered. Test
determined that the gear could be unlocked if the hand
pump was operated rapidly, and the pilot advised that he
had pumped briskly on this occasion. The checklist provided by the aircraft operator did not alert pilots to confirm the position of the gear handle before using the
hydraulic hand pump. It was not possible to establish why
or by whom the gear selector had been placed in the up
position.
Gulfstream 695-8, VH-LTM, Mangalore Vic., 20 Nov. 86,
SCPL/Cl. 1, 6000 hrs.
The crew was conducting a series of circuits and landings.
The checkpilot was sitting in the right-hand control seat
and was holding the checklist. During the circuit in question, the checkpilot spent a considerable amount of time discussing various aspects of the aircraft operation. There was
further cockpit talk during the final approach, and neither
pilot realised that the landing gear had not been lowered.
The aircraft slid on its belly for some 360 metres after
touchdown.
No fault was subsequently found with the aircraft or its
systems. The gear warning horn was serviceable but had
probably been deactivated by the pilot when power was
reduced in the early stages of the circuit. To re-arm the
warning system, the power levers have to be advanced to
about 30 per cent torque. The particular circuit was being
flown with the flaps up and was consequently conducted at
a power setting lower than that required to e ffect
re-arming.
The pilot in the left seat had experienced minor difficulties
in handling the aircraft as precisely as desired and the
checkpilot had assumed an instructional role. Under these
circumstances, the normal two-pilot challenge and response
method of conducting the various prelanding checks had
broken down.
Piper PA28-161, VH-BZB, Lilydale Vic., 09 Dec. 86, PPL,
560 hrs.
After conducting a t horough preflight inspection, t he pilot
prepared to ferry the aircraft to a maintenance organisation
which was to perform a scheduled inspection. The aircraft
performed normally until it reached a height of about 200
feet after takeoff. At this point, the engine lost a substantial amount of power and the pilot was committed to a
forced landing. During the landing roll, the aircraft collided
with a fence and came to rest in the adjacent paddock.
Initial inspection revealed that there was a serious leakage
of fuel past the fuel filter bowl seal and it was likely that
the defective seal had allowed air to enter the fuel system.
The clamping nut which held the filter bowl in place had
evidently been modified by someone other than an
approved engineer. The modification had not allowed the
bowl to be held with sufficient tension to prevent the leakage of fuel past the seal.
Cessna 210-M, VH-ITM, Batchelor N.T., 03 Sep. 86, CPL/
Cl. 4, 1290 hrs.
After takeoff, at about 100 feet above ground level, the
engine began to surge. The pilot changed the fuel tank
selection and operated the auxiliary fuel boost pump, but
the engine did not regain power. The pilot then manoeuvred
the aircraft in an attempt to find a clear area to land. However, he was unsuccessful and the aircraft collided with
trees at a low forward speed. During the impact sequence, a
fire broke out and almost completely consumed the cabin
area and the inboard sections of the wings.
Despite the extensive fire damage, small amounts of water
and rust were found throughout the fuel system. No other
defects were discovered which might have explained the
reported engine malfunction and it was likely that the
power loss was caused by water contamination of the fuel.
The method by which the water entered the fuel tanks was
not established but may have resulted from condensation
and/or the ingress of rain water through the tank caps. The
water had not been detected by the pilot during his
preflight inspection.
Gliders
Schleicher KA-6, VH-GTW, Tumbarumba N.S.W., 06 Dec.
86, Glider, 205 hrs.
Following a winch launch, the pilot spent 12 to 15 minutes
gliding before returning for a landing. On the downwind leg,
he noted that the aircraft appeared to be lower than the
height indicated on the altimeter. At about the base-leg position, the aircraft was very low and witnesses expected the
glider to land in one of several suitable paddocks. However,
the pilot continued towards the strip and the glider touched
down during the turn onto final approach. The tail section
was broken off when it contacted long grass.
The pilot had accumulated most of his gliding experience at
the particular strip and was familiar with the area. The
flight in question was to be the first made by the aircraft
since returning from another aerodrome. During his
prelaunch checks, the pilot had forgotten to re-set the altimeter to read zero feet. As a result, the altimeter was overreading by some 500 feet. The pilot had concentrated on the
indicated height and had not visually assessed the approach
profile. He was unable to explain why he had persisted
w ith the approach when he became aware that the aircraft
was abnormally low and there were suitable outlanding
areas available.
This accident was not subject to an on-site investigation.
Std Jantar 3, VB-HNI, Scone N.S.W., 30 Dec. 86, Glider,
715 hrs.
Because of deteriorating lift conditions, the pilot was
required to make an outlanding. A normal circuit and touchdown were carried out, but after a ground roll of about 20
metres the landing gear struck a large rock which had been
hidden in the long grass.
This accident was not subject to an on-site investigation.
Corrigendum
In the Final Reports section of Aviation Safety Digest 131,
an incorrect registration was given in the preliminary
inj'ormation for a DH82A accident at Bankstown on 02
Aug. 86. The correct registration was VH-ASC, not VH-ASG
as stated.
Aviation Safety Digest 133 I xi
�Aviation Safety Digest
133
Aviation Regulatory Proposals
Aviation Regulatory Proposals (ARPs) are an important means by which the Department consults
with industry about proposed changes to operational legislation and requirements. Copies of all
proposals are circulated to relevant organisations, and occasionally to individuals for information
and comment. The comment received provides a valuable source of advice which greatly assists the
Department in the development of the completed documentation.
Each edition of the Digest contains a listing of those ARPs circulated since the previous edition.
Should you wish further information about any of the ARPs, please contact your industry
organisation.
Subject
Aircraft maintenance Engineer
Licensing system
Status
Issued 9 February 1987
Comments due 1 April 1987
86/20
Agricultural operations
Issued 10 February 1987
Comments due 31 March 1987
86/21
VFR Flight below 5000 ft
Issued 19 February 1987
Comments due 30 April 1987
87/2
Authorised landing areas
Issued 11 February 1987
Comments due 30 April 1987
86/3
Aircraft maintenance policy
review
Issued 6 March 1987
Comments due 1 June 1987
86/19
Supplementary airline licence
requirement
Issued 18 March 1987
Comments due 31May1987
86/9
Approved organisations policy
review
Issued 26 March 1987
Comments due 1 July 1987
87/6
Aircraft navigation and flight
management computers
Issued 8 April 1987
Comments due 7 July 1987
Number
86/14
xii I Aviation Safety Digest 133
(
Dear Sir,
Recently I was asked to participate in a group
activ ity, t he pur pose of which was to t ake some
folk fl ying in groups of three while others were
enjoying a BBQ at the airport.
The flights were to be of various durations, viz:
20 , 30 and 45 minutes . Total flying time was to
be about 220 minutes.
While checking the aircraft I noted that one
wing tank was full and the other was at the tab
level, giving a total of 155 litres of fuel in the
air craft and a du r ation of 258 min. A refuelling
st op would be made some time during the day.
The various flights took place without incident
- I changed tanks during run-up and downwind checks as required. The fuel gauges were
showing t he usage of fuel as they indicated
reducing contents as the day wore on.
The second-last group of passengers boarded
the air craft for a 45-minute flight and while I
don't specifically remember checking the fuel
gauges while running-up on this occasion, I certainly turned int o wind and, to the best of my
memory, car ried ou t those checks.
This flight was without incident except that,
after turning off t he runway , where I stopped
to carry out the postflight checks, the engine
tended not to idle -very well, and when the
throttle was opened to taxi to the boarding
area, the response was very hesitant.
Nonetheless, we taxied without further irregularit ies. Even at t h is point of time I didn't recognise that there may have been a fuel
problem; maybe I pushed the throttle foward
too fast?
I was aware t hat the gauges were showing that
th e fuel was getting low so as I left the cabin, I
gr abbed the dip stick to check how much fuel
was in the a ircraft. When I removed the fi ller
cap from the tank it was painfully obvious that
it was not going to be needed, as I could not sec
an y fuel at all. For whatever reason , perhaps in
disbelief , I still d ropped the dip stick into the
t ank to double-check that it was so em pty . It was!
Numbed as I was, J checked the left tank and
found that t he fu el in this tank was just visible,
but n ot even up to the baffle. It was obvious
t h at the air craft needed to be refuelled, and so
I climbed aboard and did my start-up checks.
Imagine my fu rth er surprise when the e lectric
fuel pump did not quieten until I changed from
the righ t tan k to t he left.
While refuC'lling the aircraft I noticed that the
right tan k took approximat ely 20 litres before
it was to t he same level as t he ru el in the left
tank. At this stage, after t he first few litres discharged as usual, I must have pulled t he hose
and caused it to kink and restrict the flow. Not
wanting my plight to be discovered I was content to let the fuel dribllle int o t he tank and,
aller about 20 litres, I looked into t he tank to
see if the fuel was visible. It was , but it was
not enough for a further flight of 30 min ( 18 I)
and the mandatory reserve of 45 min ( 27 1) a total of 45 litres. Someone happened by and I
suggested that the underground tank might be
empty. They quickly pointed out that the hose
was ' kinked ' and re-arranged the hose to
remove it. The fuel flowed freely once again.
There are many ' what ifs' that come out of this
experience.
What if I had kept an accurate duration for
each flight 9 I would have found that each trip
(of which there were nine) was over by several
minutes each time . The total time logged for the
day was 280 minutes, as compared with an estimated 220 minutes.
What if the engine had quit on an undershoot
at 100 feet? Would I have been quick enough to
recognise the problem and change to another
tank?
What if a 'go-around' had been necessary from
a low height - same problem.
One could go on. However, what concerns me is
why this happened. I don't think I'm ir responsible, but perhaps I was complacent because I
was operating from a familiar airport. Was I
getting tired and missing vital checks? - and
the 'kink' in the fuel hose? Were there other
checks that I was missing? Why was I too
embarrassed to find out why the fuel was not
flowing properly?
This has been a vital lesson to me. Even though
the next and las t trip was uneventful , I know
that I will agonise over these events for some
time to come.
I shudder when I think how close I came.
ANON
I think that there ar e several lessons, but the
qlaring one i.s about fuel management. You
m ust n ot rely on the fuel gauges. You must keep
track of your fue l usage. You must allow a generou s margin. You m ust n ot take off without
knowing how much.fuel is on boar d.
'TIIERE'S PROBABLY ENOUGH FUEL FOR
JUST ONE MORE CIRCUIT' is the same as 'TIIE
GUN'S PROBABLY NOT LOADED '. Good luck.
IF YOU
TRUST THE GAUGES
MORE FUEL YOU
�Aviation Safety Digest
Aviation Safety Digest
133
Orchestrating a
non-accident
133
A ircraft accidents usually result in the ensuing
investigation revealing what h appened, but too
little knowledge is gained of why it happened.
The orchestration of many accidents happens
years, weeks or hours before the event - not
seconds. There is always a series of events
leading to the accident and the interru ption of
this sequence is often all that is necessary to
avoid the accident.
In general, the factors in a safe fligh t (or otherwise) can be sub-divided as follows:
the operator
(the pilot)
the machine
(the aircraft)
(the weather)
the env ironment
the terrain
(the airfield) .
Each of these factors has many elements . However, only the major ones are detailed here.
The weather
c
The airfield
How many pilots are fully aware of the requirements for using an ALA? If in any doubt you
can check the VFG. Estimates of length, width
and s lope are often suspect. Also be aware that
an ALA meeting minimum aerial agricultural
standards, will not meet private or other aerial
work standar ds. And of course, an y assessment
of the airfield has to be related to the performance of the aircraft and the performance of the
pilot in those conditions on that day.
The pilot
Steve Tizard is a most experienced pilot and instructor.
He is currently the CF/ of the Canberra Aero Club.
It takes a deliberate effort to arrange a flight so as not to
have an avoidable accident and to minimise the probability and the consequences of an unavoidable accident.
Steve's analogy of an orchestra which aims to have a
series of individual inputs co-ordinated into a smoothly
running and polished performance is a good one.
N MUSIC, EACH part of an or chestra and
each musician has to wor k in harmony to produce t he ultimate sound. Piloting an aircraft
is much like being th e conductor of the orchestra. The pilot has to harmonise the various
inputs to achieve a polished (erro r-free)
performance.
Too often , aircraft accidents are blamed on
p ilot error (finger trouble) or, in t hese more
enlightened times, the human factor. That is to
say, they are avoidable. We all know only too
well the likely types of accidents that occur and
we can each predict with some accuracy the
probable causes of next year's accidents. With
this knowledge surely we can do s omething
about our individual vulnerability to accidents.
Too little knowledge from past a ccidents is
applied to the prevention of s imilar occurrences
in the future. We keep repeating history. The
publicat ion of accidents in the Digest is a step
in the right direction. But we read about accidents and then I don't think we consciously
r elate them to our own vulnerability. It is a
pity that trends in accidents and causes of accidents (as distinct from types of accidents) are
not more readily identi fied so that emphasis on
certain aspects of training could be changed.
The accident that does not result in death or
injury should not be ignored. Repair bills cost
us all. A spate of accidents results in an
increase in insurance premiums - and look at
t he effect of litigation on the US aviation industry .
Undoubtedly he or she is the most complex
aspect of all. The question is often asked, 'Why
did a cautious and conscientious pilot convert a
costly piece of serviceable machinery into a
heap of junk?' It is interesting to nbte that a
pilot is tested on a w ide range of topics, yet
r arely, if ever, is he encour aged to make a critical examination of himself. A healthy person
with a valid pilot's licence and meeting all legal
r equirements is not immune from h aving a flying accident. Take the case of a pilot who
a rrives at an ALA after a long flight. His judgment and ability during that final landing may
not be commensurate with his 'normal'
performance.
This pilot may h ave been subjected t o
navigational difficulties, deteriorating weather,
s ick passengers a nd tiredness (to name a few
examples). His performance, under th ese circumstances, may not be as good as the same
landing s ituation when not subjected to these
additional pressures. Such pressures are not
necessarily counteracted by experience but
rather by a disciplined approach to all aspects
of fly ing and an awareness of the problems.
What about flying skill?
This article deliberately avoids discussion on
skill or technique. These aspects vary from
individual to individual and from day to day.
Only you know if your performance is up to
scratch. Only you can ensur e that you have a
margin for e rror to allow for your level of skill
in that situation on thal day. However, the old
The aircraft
Knowledge of all flight procedures, the
a ircraft's handling characteristics, normal and
emergency procedures plus currency on t ype,
are essential. No matter how mentally prepared
you are for the flight, the knowledge and proficiency described above is still paramount.
To load an aircraft over its AUW or CG limits
or to fly outside the approved flight envelope is
courting disaster - and there is no excuse.
Flight instructors regularly find , during biennial
flight reviews, t hat essential knowledge of the
aircraft is lacking. A reason for t his is often
due to insufficient flying. While flying t raining
has become comparativ ely cheaper over t he last
forty years , many people do not allocate sufficient funds for continuation training. Remember currency requirements are minimum
requirements. And currency relates directly to
the type of flying t hat you are a bout to do.
Knowledge of weather and its effects is often
forgotten immediately after an exam, hav ing
been dismissed as no longer relevant. Yet the
theor y of many 'Met' topics is an essential aid
to understanding the subject in broad terms Lo explain what we encounter in practice and
then to be better able to predict what the consequences will be. Flying conditions associated
with thunderstorms , fronts, icing, sea breezes,
the formation of fog and the effects of density
altit ude are amo ng the subjects which m,itsl not
be forgotten.
0
saying of 'poor planning leads to a poor perrormance' just as 'a poor approach leads to a
poor landing' is very true. No matter how
skilled you are as a pilot you arc vulnerable to
an accident - in some circumstances. You have
to recognise that vulnerability and make an
allowance for it. If all else fails always leave
yourself an escape route.
Conclusion
For the reasons discussed, you and you alone,
as the pilot in command, are totally responsible
for orchestrating a successfu l flight.
Remember this formula
PILOT PROFICIENCY AND
CURRENCY ON TYPE
+
CORRECTLY LOADED AIRCRAFT
+
CORRECT TECHNIQUE
+
SATISFACTORY ENVIRONMENTAL
CONDITIONS
+
SUITABLE AIRFIELD
SUCCESSFUL FLIGHT.
The safe and successful integration of these
various inputs is up to you as the conductor,
the orchestrator of the performance, the
pilot-in-command.
!Bravo! Bravo! Encore! Encore!! 0
�Aviation Safety Digest
133
Water, water
everywhere and
not a drop to
drink
During an on-site inspection it was found that
t he strainer contained mostly w ater and the
carby contained a fifty-fifty mix of fuel and
water. Samples from the right tank were clear
but the left tan k contained significant amounts
of water.
The pilot was apparently not aware of the wing
rock requirement for checking the drains in
Cessna a ircraft with bladder fue l tanks.
The seals on the fuel caps were in poor shape
and the aircraft had been out in the open during rain sho wer s during the previous few days.
It is presumed t h at the attitude change associated wit h full flap select ion together with the
prior selection of both tanks was enough to dislodge water that had been pooled in the
recesses of t he left hand bladder tank and this
failed the engine.
0
Thrice
Twice
Once
1•
HE PILOT was taking his grandchildren on
a sh ort cross-country trip. During the
.!_ preflight he found water in the fuel w hen
he drained samples. He drained t hem until no
water r emained and a lso drained the strainer
drain until it appeared clear of water.
Most of the flight was routine with the right
tank selected. The pilot selected both tanks on
dow nwind before landing. As he rolled out on
final he selected full flap (none ha d previously
been extended) and the engine suddenly s uffered a total loss of power.
The pilot managed to glide over a railway cutting but the le ft main gear hit a cement post
and the aircraft hit the ground some two metres
further on. The undercarriage leg was severed
half-way along and the stub had dug into soft
earth. The Cessn a pitched forward on to its
nose a nd r ight wing tip before falling back onto
its belly.
No-one was hurt. (Remember this pilot was
carrying his grandchildren. Imagine his feelings
if they had been injured .)
The Cessna 206 had undergone a major inspection and subsequently r emained in the open.
During this period there was heavy rain and
flooding. The tan ks were full except for the
fuel used du ring regular ground runs of the
engine.
The aircraft was then sold , and prior to deliver y was taken on a check flight. The p ilot carried out wh at was described as a ' casual ' daily
inspection and found a 'normal' quantity of
water in the fuel. On takeoff there was an
engine problem and the aircraft was put back
down on the airfield. Fuel samples s howed
about a fifty-fifty mixture of fuel and water and some brown 'gunk'.
The fuel system required extensive dismantling
to remove the sludge. The fuel pump h ad to be
reconditioned and the fuel tank caps h ad to be
replaced as the seals had deteriorated .
The method for checking for water, specified by
Cessna and the Flight Manual Supplement, was
then carried out. (This entailed rocking the
w ings and lowering the tail to disturb the water
trapped in the gullies of the fuel bladder inside
the tanks . This check was done unt il there was
no further s ign of contamination.)
The aircraft then departed on its delivery
flight. During this flight there was another serious engine problem which required an emergency landing. More water was found in t he fuel
system and, after fu rther fuel draining, it was
delivered to its new owner. The aircraft was
refuelled and more water was s ubsequently
found. That evening the CFI took his wife and
family on a night VMC flight! He ret urned
safely but subsequently more water was found
in the fuel sys tem.
Neither the n ew owner nor the CFI was told
about the history of water contamination i n
this aircraft.
The Cessna h ad been parked in t he open for
s ome days and had been subjected to numerous
rain showers. A substant ial amount of water
wa s d rained from the fuel system durin g the
prefligh t.
Shortly after takeoff the engine lost p ower and
the pilot manoeuvred for a forced landing. He
was able to obtain part ial power for a brief
period and then the engine failed completely.
The pilot w as committed to a landing on soft
wet ground.
Water was found in bot h wing tanks, the fuel
filter and t he carburettor. One of t he fuel cap
seals w as defective. Two of t he three drums of
fuel from which the aircraft h ad been refuelled
w ere contaminated.
Older Piper aircraft had a fuel drain at the
front of the tank and i t was possible to have a
w ater -free sample while the tail was down.
When the aircraft changed to a level a ttitude
th e w ater could enter the fuel lines. The
Pawnee was in this category as were the older
J3 and Super Cubs. The major problem today
though is with the Cessna singles which have a
riibber blad der tank inside each wing. It is a
frequent occurrence that wa ter can si t in the
f olds of the bladder and not be detected in a
fuel d rain - hence the procedure of rocking
the wings and lowering the tail to disturb the
pudd les.
Our lives depend on a reliable engine. The
engine depends on pure and correct fuel.
I would a dd tw o further points:
• if you are doing a 'check.flight' d on't risk
other peoples lives, esp ecially loved ones
• if you susp ect the ai rcraft has a p roblem t ell
t he poor pilot who is about to fly it. Perhaps
one day someone will return the favour an d
w arn you of a problem, and that warning
could save y our life or the lives of your
family 0
�Aviation Safety Digest
Aviation Safety Digest
133
133
Shear terror
'1 ,12 't I NDSHEAR
has become the bogey of modW.4 ern
flying. Several lar ge jet aircr aft have
been lost because of it. It is s till not fully
~rstood , at least to the e xtent of being able
to predict or det ect it. The avionics manufactu rers are wo r king flat-ou t on solutions employing doppler radar, iner tial sensors and vertical
velocity sensors . These techniques are designed
to help t he pilot to detect the presence of
marked w inds hcar early enough for the a ircr aft
t o avoid or to recover from it.
It seems to h ave only recent ly appeared but like
the medical profession , most ailments have been
around a long time an d only now arc being
unde r stood and correctly classified . Windsh ear
has a lways been around t oo. Only now is its
significan ce being underst ood as onl y now ·are
massive air craft with enormous values of
momentum commonplace.
That 's correct - the lar ge aircraft are more
vulnerable to s hear t ha n smaller ones. And t hat
has only recent ly been understood . It's incredible to t h ink th at a 'Jumbo' of some half a million pounds all-u p weigh t is vulnerable t o wind
effects .
It is a lit tle h ard to come to gr ips wit h , but it is
essen tial in unders ta nding windshear t o understa nd t he d ynamic effects as well as the aerodyna mic effects on a n aircraft.
An aircr a ft cruising along at constant altitude
and ai rspeed h as a cert ain momentum, i.e . a
certain tenden cy to cont inue at that speed and
in that direct ion. The strength of that tendency
is equ iv alent to its velocity mu ltiplied by its
mass . Moment um equals m X v. That is, the
more massive it is and the fast er it is tr avelling
the gre ater the momentum.
The velocity we are talking a bout here is it s
velocit y in space, ·measured from it s starting
pos ition on t he eart h , i.e. i ts speed relative to
the earth.
This concept is the cr ux of our understanding
of windshear. When we are ta lking a bout
momen tum we arc dealing w it h speed relat ive
to t he eart h a nd t hat is 'ground speed' . As far
as momentum is concerned th ere is no wind an d
no such thing as airspeed. It only deals with
s peeds re lat ive to the eart h . And t hat is t he
p roblem, because aeroplan es must deal in a irspeed . They mus t , because below a cer tain
value the aircraft w ill cease flying, or at best ,
s uffer from a n enormous drag rise.
So our Jumbo, cruising at a ground speed of
550 knots at a mass of 300 OOO kg, has a
momentum of 550 X 300 OOO units. A Warrior
at a ground speed of 100 knots and at a mass of
1000 kg has a momentum of 100 X 1000 units.
The momentum of the J u mbo is 165 million
units compared to the Warrior 's 100 thousand.
It is 1650 times as much , and that repr esents a
much stronger tendency t o continue at it s parti cular grou nd speed and in its particular
direction .
This momentum is both good news and bad
news. It means that the J umbo is more r esistant
to a disturbance of its flight path, and in terms
of ease of flying, this is a bonus. The aircraft
will t end to stay 'on the rails' or 'in the groove' .
Conversely the War rior will req uire more active
pilot participation to maintain a steady fligh t
path.
If the Jumbo exp eriences a transient gust or
momenta ry turbulence, it will ride t he distu rbance by the aircraft continuing due to momentum and t he structure absorbing the
disturbance by flexing of its w ings. ·The Warrior w ill feel the distur ban ce, and because of
t h e low momentum, will react to it by a change
in flight p ath. The p ilot is r equired to contribute more to t he maintenance of a steady fli ght
path in t he small air cr aft than t he Jumbo.
These then are t he benefits of high momentu m.
What is th e disadvantage?
Look again at the J umbo cruising at a ground
speed of 550 knots. Say there is a head-wind of
50 knots . The air speed is therefore 600 knots .
(Assume for now that T AS= IAS = CAS .)
Remember the momentum is the strength of the
tendency to continue at that ground-sp eed and
in t hat direction. Let the wind suddenly stop .
The air craft will tend to continue at a ground
speed of 550 knots . With the wind gone, t he airsp eed drops instantly to 550 knot s. If the t h rust
w as left at the va lue for 600 knots IAS, then
the air craft will gradually accelerate to that
s peed (an d a ground speed of 600 knots in nil
w ind, but the th rust h as to change the moment um and that takes t ime). Not e th at for a fi nite
t ime t he a irspeed dropped by the valu e of the
change in wind velocity.
Try a J umbo at a gr ound-speed of 550 knots
and a t ailwin d of 50 knots. The airspeed is 500
knots. The w ind drop s and the J um bo q uickly
shows an a ir sp eed increase to 550 knots until
t he thrust deficie ncy causes a reduction in
momentum. (Note th at while the moment um is
t he tendency to continue at t hat speed, th e
t hrust must still over come t he d rag to pr event a
gr ad ua l decay in speed.) Note also that t he drop
in tailw ind has caused an increase in airspeed
equal to t h e change in the w ind velocity.
0
Once more, an aircraft with high values of
momentum shows a change in airspeed due to a
change in wind velocity . The magnitude and
suddenness of the change is a direct function of
the changing wind. The duration of the change
is a fu nction of t he ability of the aircraft to
change its airspeed and that depends on excess
t hrust available, pilot reaction time, and engine
reaction time .
The small air craft with low values of moment um on the ot her hand is a ffected by the drop
in wind and simultaneously by the changed
dr ag due to the changed airspeed. It t herefore
respon ds immediately to restore the trimmed
airspeed, and because of the low momentum,
there is not a significant delay. That is not to
say t hat the small aircraft is not vulnerable to
shear but t hat it reacts more quickly and is
t herefor e less likely to develop h igh sink rates
or to fall below Vs during the airspeed
transients.
The problem is compounded when we realise
the low values of excess thrust possessed by
the lar ge transport and the lengthy acceleration
t imes of a gas t urbine engine. Further, the
momentum comes back into play if the aircraft
st arts heading downhill; remember, momentum
is also a tendency to continue in a particular
direction, and once that is downwards , the a ircraft will almost inevitably consume a large
amount of alt itu de in the attempted go-around .
The pist on engine h as almost instantaneous
thrust response. The turbo-prop has the turbine
alread y spun-up and only requires a change in
pr op eller blade-angle for instant thrust. The
t u rbo-jet or t urbo-fan has to spool-up , to accelerate t o high rpm before any significant thrust
in crease is available.
So the p roblem is compounded in jet aeroplanes.
What can be done?
G
Pro blem number one is to predict the conditions
where t he w indshear is likely or is severe. Data
is being accumulated to this end.
Next w e can s urmount the thrust delay problem
by car rying extra drag a nd therefore extra
th rust on final ap proach.
But we can 't car ry sufficient excess airspeed on
finals to counter the shear and still land
successfully.
This is the r eal problem. We need a reserve of
air speed which we can't afford to carr y and an
excess th rust we can't afford in terms of
reduce d p ay load .
Resea rch in the United States has employed
Flight Simula tors to replicat e the behaviour of
aircraft in sever e windshear conditions. Pilots
can t hen develop and rehear se flying techniques
t o counter the problem.
In some conditions experienced in p r actice and
reproduced in the simulator, the only
survivable technique was to go-arou nd and wait
until conditions improved. Befor e putting our
heads into t he lion 's mouth, we should consider
t h e consequences of it sneezing!
As far as the problem of flying is concerned,
the optimum technique appears to be:
• apply full power early
• hold a constant angle of attack while the
engine is accelerating, i.e. keep just OHt of
the stall warning regime by gently lowering
the nose, but
• don't lower t he pitch attitude to the extent of
developing excessive descent rates, while you
are trying to eradicate the stall-warning
• gently trade airspeed for a positive rate-ofclimb as the thrust picks-up.
I3ETTER STILL, DON 'T I3E PLACED IN THAT
POSITION IN THE FIRST PLACE.
What does all of this mean to us littlies?
Although it appears we are not as badly off as
larger aircraft, we can still lose control. We are
better off if we keep our minds on the job and
avoid these situations. We have many cues to
windshear in a small aircraft because we are
more exposed and more sensitive to conditions
than a large aircraft.
The pilots involved in the following situations
have kindly described what they experienced. I
publish them, not to criticise but to show that
windshear is serious, and in retrospect there
were clues that they could have used to avoid
the problems.
Southern Cross Scare Race?
Bill Huntly recalls his confrontation w ith a
storm at Echuca. [I was on the ground watching
and I thought that the a ircraft was going out of
control as it t r ied to go ar ound.]
Under the storm T
�Aviation Safety Digest
Aviation SafetyDigest
133
'My incident occurred during the final stages of
Day 1 of the 1986 Southern Cross Air Race. As
pilot-in-command of the PA-28-181 we were
third in line to commence an extended
downwind for runway 35 at Echuca. This
extended downwind commenced about 5 nm
north of the aerodrome. At about this time I
became conscious of a " black wall" a pproaching
from the west. This thunderstorm a lso s howed
a few flashes of lightning. I estimated it to be
quite a few miles away.
' However, when we were approx imately halfway along the downwind s ide of the strip, I had
my doubts that we would beat the s torm. As I
turned Base I noticed the a ircraft in front of me
had touched down and t he windsock was pointing directly down RWY 35.
' When I turned final, the wind direction had
cha nged and was now indicating the w ind to be
from the west. The strength of the w ind was
s uch that I was easily blown off t he runway
centre-line a lthough I was lay ing-off a bout
30-35 degrees of drift. Without hesitation I
elected to have "another go" - this time for
17, now that the wind was more or less favouring the south/ west - it had changed yet again.
Turning final at a height of 500 feet, I felt that
the wind was of a force that I had never
experienced before. I elected to go around. and
at the same time turn on an easterly heading
away from the storm which was over t he western perimeter of the aerodrome.
133
or trees
.& Bill's storm
After the storm
and shrubs which effectively shield the
northern threshold from a westerly or southwesterly w ind .
The wind was from the south-west at about 30
knots. Th e pilot soon realised that the conditions were not suitable for his flight and
decided to land.
Final approach was made to t he south w ith
some power and with full fl ap selected . The
s peed was about 10 knots high er than normal.
The conditions were gusty. The aircraft did not
settle in the flare and the pilot decided to go
around.
The main wheels touched down briefly as the
pilot rotated t he aircraft and the aircraft had
reached a height of about 10 feet when it
passed abeam the end of the sheltered zone.
Suddenly and violently the aircraft s hifted to
t he left.
The nose dropped s harply and then veered to
the right when the nosewheel contacted t he
ground with a loud apparent breaking noise.
The mains then touched down. The nosewheel
was dragged a long the grass for about 10
me tres before the aircraft became a irborne
again.
After liftoff the nosewheel light went out and
the gear unsafe light illuminated. The pilot
diverted to Bairnsdale where a safe la nding was
made. The nosewheel leg was bent s ideways .
Post flight weather analysis s howed that windgusts in the area could h ave been as high as 50
knots.
The pilot's decision to go to Bairnsdale was a
good on e - if only he had made it before
attempting the approach into the ALA.
[A part-sh eltered thres hold or strip is no place
to be when the wind is that strong.]
~
'I "firewalled " ever ything and tried to gain
height, but the a ircraft was still descending at
1000-1500 feet per minute on the VSI. At one
stage t he airspeed indicator was indicating 135
knots and the stall warning beeped . The t urbulence was horrendous. I thought we were going
to roll inverted. The biggest problem at t he time
(which lasted a couple of minutes) was the
inability of the aircraft to outrun the storm. It
seemed to be gaining on us. I st a rted turning
north gradually, trying to get on a heading for
Deniliquin which I knew was OK becau se other
a ircr aft were landing there. I eventually completed the turn towards Deniliquin and we wer e
in the clear. Then we heard a r adio broadcast
that the storm had passed over t he aerodrome.
We proceeded around behind t he s torm a nd
completed an uneventful landing.
'In w riting this note I'd first like to say I have
never experienced anything more vicious (for
want of a better word). My pilot friends on
board were of a simil ar frame of mind. The
pure force of this wind was unbelievable. I'd
like to know what the w ind velocity was!'
Aggravated approach?
Discretion is the better part . . .
It was quite windy when the Arrow took off
from the s trip at Fraser Is land. The s trip was
a bout 450 metres long wit h overruns of 40
metres at the nort hern end and 110 metres a t
the southern end . On the western boundary,
along the nort he rn half of the strip, was a line
0
c
The pilot had landed at the one-way Ag strip
before. It was 490 metres long, grass and on the
crest of a hill.
The pilot called the owner to make sure it was
clear of sheep and cattle and took off. Enroute
conditions were turbulent w ith a moder ate to
strong north-westerly blowing. The pilot
decided to make a dummy approach to assess
the conditions before landing.
As he crossed the threshold he found t he conditions were good. He made a snap decision to
land a s he reached a point one-third of the way
along the strip. After touchdown the aircraft
passed beyond the portion of the strip that was
protected by trees and it was suddenly exposed
to a strong gusty crosswind. The left wing was
lifted and the aircraft moved to the right.
The right wheel was twisted when it struck an
earth mound and the a ircraft crossed two deep
vehicle tracks a nd passed t hrough a fence. No
one was hurt.
[That part-sheltered threshold again.]
Fatal arrival
Dr Donold Allsop from South Africa recounts
his bit ter meeting with a storm.
'It was in December 1977, in North Transvaal,
South Africa. I was planning a pleasure' t rip.
The weather was cloudy with scatter ed t hunderstorms . Johannesburg weather was assessed
as "safe to fly" (VFR). I was comin g in to land
about an hour-and-a-half later in a Cessn a 172.
By this time t he thunderstorms were heavy and
much nearer to the airfield.
'On the first touchdown, t he w ind was swinging
behind - I was too fast - I went round. An
instructor happened to be flying nearby. We
discussed the situation on t he radio and I
turned to make another app roach. (I had 450
hours and had done some aerobatic training.) I
can 't remember anymore after that. I spun from
1000 feet on Final - due to wind s hear - confirmed two years later by the DCA inspector at
the inquest. My w ife was killed and I was badly
injured. It was N OT PILOT ERROR! I had never
heard of "windshear" before this incident.
'My advice is, " KEEP A WAY FROM THE EDGE
OF THUNDERSTORMS" . This one was more
than five miles away and passe d over in 15
minutes. What rotten luck!'
In all these instances ther e were warnings. The
big blokes can be caught out wit hout warning,
but we will rarely not have some clues. It's up
to us to listen to our inner self and get out of
the situation before it becomes uncontrollable.
It is not good enough to 'suck it and see' . While
a light aircraft will gener ally be a ble to escape
from the shear , it is still possible to find ourselves in a s ituation where we lose control near
the ground or wh ere we s imply haven't sufficient excess t hrust or control power to climb
away and ma intain attitude.
We have to make the decision before we commit
ourselves to a landing and that decision s hould
be made on final. I use the PUF check as the
point where I decide whether or not to give it a
go. If there is any s ignifica nt turbulence, any
significant airspeed fluctu ations, any lateral
control problems, i.e. if I have to use large and
rapid aileron inputs, or if t h ere are any significant changes in lift and sink on final , I go
around and reassess the s ituation from circuit
height. It is difficult to define a yardstick for
t he go-round decision. Ultimately, if it starts to
w orry me unduly, I give it away and climb for
another look.
If there is a decent wind blowing a nd there are
trees on s hort final I prepare myself for a
go-around from the flare.
If it gets out of hand:
• SET FULL POWER AND THE CLIMB
ATTITUDE AND HOLD ON.
• RETRACT THE GEAR AND REDUCE THE
FLAP FROM FULL TO INTERMEDIATE
WHEN YOU CAN D
�Aviation Safety Digest
Aviation Safety Digest
133
133
My eyes are
dim, I cannot
see ...
This article is based on the Executive Summary of a
Report by B. L. Cole and J. L. Ungerer of the Victorian
College of Optometry. It describes a survey of the use of
glasses by pilots over the age of forty. It has significance
for many of us 'old-and-bolds'.
HE ABILITY of the eyes to focus at near
distances decreases progressively with age
so that between the ages of 40 and 50 ye ars
difficulty is experienced seeing objects clearly
at close range. This limitation is called ' p~esby
opia' and is a normal phys iologica l change that
occurs with age. It requires correction w ith
r eading glasses or multifocal glasses to provide
clear, comfortable vision for near-reading tasks.
Pilots have a visually demanding tas k requiring
clear close-in vision for reading operational
charts and manuals as well as flight and engine
instruments - especially at night when cockpit
lighting is subdued. Because of this it was
expected that pilots may be troubled by the
onset of presbyopia at an earlier age and since
pilots arc subject to regular assesssment of
vision, work in a highly regulated and safety
conscious industry and have a visually demanding occupation, it was expected that most pilots
over the age of forty would seek spectacle correction for presbyopia and make u se of glasses
when fly ing.
It is well known that the near visual tasks
involved in flying pose some special problems
for prcsbyopic pilots because charts, manuals
and instruments are at widely varying distances
from the eye. The overhead panel in particular
poses a problem because of its location and
close ness. It is difficult to prescribe corrective
lenses that enable clear vision at near distances
and still ensure that more distant instruments
are clearly seen. Alternatively, there may be a
need to use complex forms of lenses, such as
trifocals, progressive power and quadrifocals,
that provide clear vision at several near distances. It was expected therefore that older
pilots would experience problems with some
near tasks even with appropriate spectacle correction for their presbyopia and would frequently have spectacles using more complex
lens forms.
A questionnaire asking about the use of glasses
and vis ual difficult ies when flying was
designed. It was sent to 1300 pilots who were
over the age of forty years and held an Australian commercial, senior commercial or airline
transport pilot's licence. The response rate was
75 per cent. Although the study did not
encompass private pilots, it was considered to
be equally valid.
The purpose of the questionnaire was to document the u se of glasses by pilots like ly t o be
presbyopic and to relate t he main vis ual difficulties to the type of glasses used. Perhaps
some conclusions could then be drawn about the
forms of visual correction best suited to the
task of flying .
Principal conclusions
1. Failure to obtain or use presbyopic correction. A surpris ing result was th at 45 per cent
of all the pilots who r esponded and 17 per cent
of those over t he age of 50 years (an age when
presbyopia is well established), did not use
glasses when flying even though a number had
glasses for use at home or were required to
carry glasses when fly ing. Several respondents
admitted difficulty seeing at near distances
although they had passed the statutory t est and
were not required to wear glasses . These
findings suggest that the procedures for examination of near vision for pilots over the age of
forty years should be r e-assessed, possibly
introd ucing earlier and more frequent
assessments and more rigorously defined
methods of assessment. In addition , a significant proportion of pilots had not had a change
of glasses for five or ten years. Age of glasses
was related to visual difficulties especially
with charts and manuals and more rigorous
periodic assessment of vision might encourage
the maintenance of optimum s pectacle
correction.
2. Factors determining use of glasses. The
use of glasses when flying was strongly dependent on age, as expected, but only weakly
associated with the extent of flying or the
degree of responsibility taken. Thus it cannot
be assumed that senior pilots fly ing scheduled
air transport will show greater compliance in
the wearing of glasses than those who fly
smaller aircraft or who are part time. The question of compliance in the use of glasses when
flying may deserve further investigation.
3. Infrequent use of multiple focus glasses.
The most common forms of sp ectacle correction
were lookovers ( 43 per cent of those who wore
glasses when flying) and bifocals (36 per cent).
Relatively few (9 per cent) made use of
trifocals, progressive power lenses or other
multiple focu s lens forms. Even for pilots over
the age of 55 years, when multiple focus correction is strongly indicated for a tas k like flying ,
only 19 per cent of pilots had been prescribed
these forms of lenses. A large proportion of
p ilots report difficulty seeing charts and
manuals and there is evidence that this arises
in part through the prescription of glasses to
ensure clear vision for instruments at the cost
of the ability to see charts and manuals. In
order to over come this problem there is a need
to explore t he means by which the use of multiple focus glasses can be encouraged.
4. Suitability of trifocals. There is some evidence that conventional trifocals are not suitable for flying. Only two of the 16 pilots who
had t rifocals for their previous glasses had
trifocals prescribed for their current glasses.
The others had changed to other lens forms .
Eighteen per cent of t rifocal wearers compl ained the 'segment was too small' while only
six per cent of bifocal wearers had that complaint. This and other comments made by the
respondents suggests that the vertical depth of
the intermediate segment of conventional t rifocal is not deep enough to give a sufficiently
wide field-of-view for the instrument panel. The
suitability of t he occupational trifocal with a
deeper intermediate segment should be
investigated.
5. Are progressive power lenses suitable?
Although progressive power lenses are currently not recommended for use in flying, fo ur
per cent of those wearing glasses had progressive power lenses. Some pilots repor ted t hat the
lens form was ideal although others commented
that it w as not suitable for flying. Those wearing progressive power lenses made significantly
more reports of difficulty with t he instrument
panel and there were a number of reports of
trouble with distortions and illusions. However,
five of the seven who had this form of lens in
previous glasses retained the same fo rm in t heir
current glasses - s uggesting the lens for m is
successful for them. The literature indicates
that this form of lens has high acceptance by
pilots . The suitability of progressive power
lenses requires further considerat ion. There are
two basic forms of progressive power lens and
one may be more suitable than the other for flying.
6. Problems with sunglasses. Two-thirds of
pilots use sunglasses when flying , s upporting
the conventional view t hat pilots are often
exposed t o glare. A common problem reported
was that there was no glare protection incorporated in spectacle correct ion so that either
the spectacle correction had t o be removed to
enable sunglasses to be worn or gla re protection
had to be foregone . Lookovers pose a special
problem in this regard and nearly half of the
pilots who used lookovcrs removed their
lookovers to wear sunglasses. Of those pilots
who reported the need to use their lookovers
for the instrument panel , over a third removed
their lookovers when wearing sunglasses. There
is a need to encourage the prescription of
bifocals instead of lookovers so that a sunglass
tint can be incorporated in a second pair or
clip-on sunglasses can be used . Although the
use of photochromic lenses is discouraged , 13 .6
per cent of pilots use photochromic sunglasses.
T hree pilots reported that the react ion of
photochromic lenses was too slow .
7. Problems with charts. Over one-quarter of
pilots reported difficulty with charts and
manuals. In part this is shown to be the result
of the compromise between the need to see the
instrument pane l at distances of 750 to 1200
mm as well as charts at ordinary reading distance of 300 to 400 mm. Many pilots commented that the design of charts could be
improved by increasing the size of crit ical
alphanumeric information and increasing cont r ast and there may be merit in investigating
t he options for improving the design of charts.
The problem can a lso be addressed by encouraging regular eye examination and maintaining
optimum s pectacle correction and by encouraging the use of su itable multi-focus lens forms
rather than lookovers and bifocals.
8. Problem with the overhead panel. The survey confirmed that the overhead panel does
cause visual difficulty. Forty per cent r eported
difficulties although two-thirds said it was not
a problem. Only six pilots had special glasses
designed to assist them with the overhead
panel. Pilots and prescribing practitioners
should be made aware of the opt ions available
to assist t hose who have particu lar difficulty
with the overhead panel.
9. Compatibility with the oxygen mask.
T hirty-s ix pilots commented t hat glasses were
not compatible with the use of oxygen ma sks
and 11 reported the same difficulty w ith t he
radio head set. T he lack of compatibility with
the oxygen mask deserves furthe r investigation .
[The survey has shown us some potential prob_lem areas bu t in the interim it can only be
emphasised that if near-distance focus is a
problem, you must seek professional advice.
Vision is still the pilot's most important asset.
A n d please - if glasses are prescribed - wear
them.] 0
FLYING is not ...
a TRIVIAL PURSUIT
�
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133
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1987
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ASD 132
AUTUMN 1987
�Aviation Safety Digest is prepared by the
Department of Aviation and is published by
the Australian Government Publishing
Service. It is distributed to Australian licence
holders (except student pilots), registered
aircraft owners and certain other persons
and organisations having an operational
interest in safety within the Australian civil
aviation environment.
Contents
3
Editorial
4
Staggering statistics
Takeoff performance is adversely affected by many
small factors.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer (EPSD)
Department of Aviation
P.O. Box 1986, Carlton South, Vic. 3053,
AUSTRALIA
Telephone (03) 667 2733
Editorial
7 The foggy, foggy dew
Carburettor icing is still a recu rring problem serious consequences.
8
with
Flappery will get you everywhere
The optimum use of flap for you r aircraft is laid down
in the flight manual.
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.G. T. 2601,
AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops in
the capital cities.
10
NVMC -
Currency
Uncurrency leads to close shaves escapes.
11
The best-laid plans ...
At the end of the flight a change of plans is hard to
accommodate.
12
Passengers rights
Passengers have rights -
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Department. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazarduous
situations.
Unless otherwise noted, articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being cons.tructive towards flight safety.
Reader contributions and correspondence
should be addressed to:
The Editor,
Aviation Safety Digest
Department of Aviation
G.P.O. Box 367,
Canberra, A.G. T. 2601, AUSTRALIA
©Commonwealth of Australia 1986
ISSN 0045-1207
R85/979(4) Cat. No. 86 0310 3
Printed by Ambassador Press Pty Ltd
51 Good Street, Granville, N.S. W. 2142,
AUSTRALIA
and miraculous
13
Pilots rights
Pilots have rights too responsibilities.
14
and wrongs.
more importantly they have
Wiggly amps
The ups and downs of the sometimes overworked
electrical system.
16
Parting gestures
Structural failure of the propeller can be catastrophic.
18
Airflow
Your feedback column.
·2 0
Digest Photographic Competition
C'mon aussies c'mon .
21
• crosswinds and windshear
• running out of daylight
• water in the fuel.
I have tried to highlight topics in this issue wh ich may assist
pilots to mentally prepare for these problems - they aren 't
problems if you are prepared and practised for them. This
anticipation and mental rehearsal is what professionalism in
flying is all about.
I recently had the opportunity to f ly in an Ansett Boeing 767
flown by Captain Henry Landsberg, Fi rst Office r And rew
Townley and Flight Engineer Peter Nash. There were many
aspects worthy of comment but I would like to make two observations here:
• after takeoff from Adelaide, the First Officer, who was flying
the aircraft, visually cleared the flight path before turn ing and
asked his Captain to confirm that it was clear,
• du ring the approach into Melbou rne, Captain Landsberg set
his assigned altitude and asked both his First Officer and his
Flight Enginee r to read back what he had set and to confirm
its co rrectness.
This is a state-of-the-art ai rcraft with a complex computer-based
and digitally displayed flight data system and these 'humans '
were double checking everything they did - that's professionalism. My thanks to Henry and his c rew.
On a very different tack, I had the pleasure to follow the
Southern Cross Air Race and Mapping Competition in conditions
that were close to the autumn weather I have high lighted above.
I found the standard of piloting and judgment among the competitors to be impressive. Many turned back. Many found a way
through in marginal conditions. Many abandoned the race tasks
so that they cou ld safely cope with the flying conditions and
associated workload. Al l pilots had to contend with reduced
visibility, strong gusty crosswinds and wet surfaces. The race
was completed without incident due to the judgment and skill of
the pilots. Congratulations.
In terms of flight safety objectives, I have been told that it isn 't
possible to make much impact on the accident statistics. I can 't
accept that. I believe we can nominate specific objectives and
have a significant effect - fo r example I th ink it is possible to
have an autumn period without a sing le carbu rettor icing
incident - it doesn't take any great organising - it simply
requ ires each of us to make sure it doesn 't happen to us. That's
the basis of safe flight - each of us, making sure.
I wouldn't be seen dead without my
bone-dome
Ag pilots have to decide risk of fatal head injuries .
23
A
UTUMN IS here and with it the shorter days, earlier
sunsets, moist, cool air, strong , gusty winds, rain showers
_
and lumpy clouds.
To the aviator, autumn is a beautiful time but it brings its
challenges. Traps for the unwary include:
• carbu rettor icing
• wet runways and soft su rfaces
slight discomfort or the
Doped-up?
The ill effects of medication.
DAVID ROBSON
Editor
Covers
Front. Perhaps the most demanding and
the most satisfying form of flying is close
formation . It brings together the skills of
piloting and the skills of leadership in a
way that is intolerant of error. As a
result, I think it makes us more considerate of the other aircraft, more
aware of the environmental factors, and
more critical of our own flying.
Photograph by David Robson
Nikon F - Kodacolor Gold
from a Robin 2160 flown by Chris Thorne.
Wingpersons Jake Jansen and John
Woods. Canberra Aero Club 1986.
Back. Approaching darkness is one of
those situations where a pilot can be left
with no escape route - no way out. Be
generous with your planned reserves of
time. Plan a 'HOWGOZIT' point - an
intermediate landing point beyond which
you will not proceed unless you have a
confirmed margin between the ETA for
your destination and last light.
Poster design by John Eglitis.
Editor:
Editorial assistant:
Graphic design:
David Robson
Karen Hutchison
Lesley Gordon
John Eglitis
Tony Kelly
Photographs: P 20
David Robson
BAS/
Soussanith Nokham
John Freeman
Cartoons: P 12, 13
Aphorism:
P 21
�J
Aviation Safety Digest
AviationSafety Digest
132
Staggering
statistics
·p
ERFORMANCE-WISE, the takeoff is the
most critical phase of flight. Apparently
_ insignificant factors can add up to the point
where it is simply not possible to become airborne in the available distance or even worse,
where the pilot is tempted to 'press-on regardless' and forces the aircraft into the air at less
than safe flying speed and 'on the back-end of
the drag curve'. The subsequent lack of acceleration, lack of climb and probable impact with
trees or rising ground, is often catastrophic.
I said apparently insignificant factors - some
are, but in some cases the pilot actually causes
the situation where the chance of a safe takeoff is
slim.
Stagger one
The pilot departed his home base and flew to a
strip from which he intended to conduct topdressing operations. Shortly after liftoff, the
engine lost power. The load was dumped and the
aircraft was landed in a paddock where it collided
with a fence and ground looped.
No fault could be found with the engine which
was still idling as the aircraft came to rest.
When he had first arrived at the strip, the pilot
had left the engine idling for several minutes
while the aircraft was loaded with superphosphate and with the carburettor heat on cold.
The conditions at the time were conducive to
· carby icing. The problem was compounded by
this pilot's technique of using oruy partial power
for takeoff. More on this later.
132
Stagger two
Carby icing
The pilot had intended to carry-out a scenic
flight including some aerial photography. En
route, one of his passengers became unwell and
the pilot landed on a grass strip near the
property to let the passenger out.
During the subsequent takeoff the acceleration
was slower than normal. The aircraft was pulled
into the air at the end of the strip but it then
descended, ran through two fences and collided
with some farm machinery. It came to rest in a
nearby river bed.
Before takeoff, the pilot had looked at the performance charts but:
• the strip was 100 metres shorter than
estimated
• the weight of the aircraft was incorrectly
estimated
• the strip was covered in grass some 20
centimetres long
In fact the strip was only half the length
required under the circumstances and the long
grass became 'the final straw' which precluded a
successful takeoff.
There is nothing new about carby icing. If the air
is moist and cool, the temperature drop in the
throat of the carby can be sufficient to form ice
- and this obstruction has a direct effect of the
power output of the engine - a negative effect.
If the conditions are such that it is foggy or feels
damp, humid or muggy or the engine does not
produce full static rpm or if you have to idle for
a long period, always do a full power check and
run the engine for a time with the carby heat ON
to compare rpm - before y ou attempt to takeoff
Similarly, if you are airborne in these conditions,
run the engine with the carby heat ON at cruise
power before you reduce rpm for_landing - you
may need full power for a go-around.
Stagger three
It was hot and there was a gusty wind blowing
across the strip. The aircraft appeared not to
climb away normally. It passed over a boundary
fence and remained at tree-top height for about a
kilometre. It was then seen to turn sharply and it
disappeared from view. It was later discovered to
have struck the ground in a steep nose-down
attitude and was completely destroyed by the
post-impact fire. Three of the four occupants
died.
No evidence was found of any defect or malfunction with the aircraft. The takeoff had been
attempted with the aircraft's weight approximately 20 per cent above the maximum
allowable and alt hough it became airborne, the
combination of excess weight and the hot, windy
conditions denied the aircraft any climb performance or acceleration.
Factors
There were several obvious factors in our
examples:
• carburettor icing
• part throttle takeoffs
• misjudged strip length
• misjudged or excessive gross weight
• insufficient allowance for environmental
factors - long grass, high temperature and
high humidity.
Let's take them one at a time.
Part-throttle takeoffs
Don't do it. There is a false premise that reduced
power on takeoff will extend the life of the
engine. Similarly some pilots reduce to climb
power just after liftoff, 'to save the engine'.
These are false assumptions because:
• at this low airspeed, the reduced airflow means
reduced cooling of the cylinders and the higher
CHT causes additional stresses in the engine
• the reduced power also means reduced carby
heat to the extent that it could delay clearing
the ice
• part-throttle takeoffs increase the temperature
drop across the carby throat thus increasing
the possibility of induction icing.
Also, all the performance estimates are invalidated if you don't use the recommended settings
- there is no way of predicting what the performance will be, and if you discover that you
haven't used enough power, then what? (You 've
probably heard the saying about altitude above
you and runway behind you - 'power you didn't
use' is in the same category.)
Misjudged strip length
The only way to estimate the length of the strip
is to pace it out yourself. You may feel instinctively that a strip is marginal - don't risk it.
Pace it out.
Misjudged gross weight
This is a kind way of saying overloaded aircraft.
Once again the only way to tell is to measure
everything you put into the aircraft. You can
estimate by equating payload to fuel, e.g. one
pax equals about 110 litres of fuel. I know the
problem is compounded by the mix of metric and
U.S. units but that is something that we, as
pilots, have to accommodate. Don't forget that
this rough estimate does not take into account
the centre-of-gravity. If the tanks are near full, if
the seats are near full or if the baggage compartment is near full - always do a proper weight
and balance calculation - and then calculate
your takeoff performance unless you are certain
the strip is more than adequate.
�l
Aviation Safety Digest
Aviation SafetyDigest
132
132
Environmental factors
The 'P' charts take into account the ambient
temperature and pressure altitude and hence DA
- density altitude. In a GA aircraft flight
manual there is no allowance for surface conditions. The charts show the performance of the
aircraft as tested - from a level, dry, paved surface with the engine at optimum power output
and flown by an experienced pilot using what the
manufacturer's test pilot deduced as the
optimum configuration and technique. The
Australian flight manual for the aircraft then factors this performance by an extra 15 per cent to
allow a margin for less than optimum conditions.
Under most circumstances this is a conservative
guide to your aircraft's runway requirements.
But if you have less than full power, carby icing,
uphill slopes, high humidity, soft surface or long
or wet grass, then things are not so rosy.
Carburettor icing -
As a guide, the effect of an uphill slope of only
2 per cent is to add about 14 per cent to the
takeoff run - there goes our 15 per cent margin!
The effect of wet grass or long dry grass is to
add about 6 per cent to the takeoff run - the
effect of both the uphill slope and the long grass
is to add nearly 25 per cent to the distance!
As pilot-in-command of the aircraft it is our
ultimate responsibility to make these allowances
- and we can only do that if we start with an
accurate weight, strip length, temperature, slope
and wind velocity and if we use the power setting, configuration and technique recommended
by the manufacturer.
Further, a trick used by old hands is to nominate
a 'HOWGOZIT' point - a reference by which
they can judge how it's going. By observing the
performance of your aircraft at different weights
and temperature conditions against a feature say
200 metres along the strip, you will get to
recognise the range of speeds that you should
expect as you pass this point. If you're
appreciably below the usual speed, then abort the
takeoff while there is still plenty of room to stop.
And watch out for carby icing 0
probability chart
,100%
S ATUR ATED AIA
( WET BU LB"" DRY B ULB)
To use the chart
- Plot the wet and dry
bulb temperatures or
one temperature against
the Relative Humidity
80%
-The intersected point wi ll
show the probability and icing
from the shading legend
70%
>
Example described in article
60%
- Wet bulb temperature 15.5° C
1-
c
::?:
~
- Dry bulb te mperature 17°C
50% J:
UJ
- From intersectio n of the temperature lines the
shading l eg end gives , 'moderate icing - c rui se
power , seriou s ic ing - descen t pow er'
>
I<(
40% ~
- Relative humiduty 85 per cent
a:
lilill&f:I
30%
SERIOUS I CING · ANY POWER.
~ M O DERATE ICING - CR UISE POWER OR
~S ERIOUS I CING - DESCENT POWE R.
20%
r."7'J SERIOUS ICING • DESCENT
L:.:.:j POWER.
10%
rr7:1 LIGHT I CING • CRUI SE OR
LJJj DESCENT POWER
0
5
10
15
20
25
30
DRY BULB TEMPERATURE °C
35
The technique I was taught was t o:
• start the engine with the carby heat off;
The foggy,
foggy dew
• check the carby heat on run-up - with the
engine at run-up rpm select carby he~t on.
There should be a slight drop in rpm. If there
is an increase in rpm or an increase following
an initial drop, leave the rpm set and the
carby heat on for a good few second s and then
select carby heat off for takeoff. (If the takeoff
is then delayed run the engine at run-up rpm
with the carby heat on before you roll and
reselect carby heat off for the takeoff.);
• watch for any drop in rpm, manifold pressure
or EGT or any power loss in flight and if you
suspect carby icing, select full hot and leave it
set until the power or rpm is restored;
• if you have a carby throat temperature gauge,
then use carby heat to keep t he needle in the
green and keep an eye on it, particularly if you
are approaching cloud, fog or rain;
T
HE BELL 4 7 was enroute from Sydney
Harbour to Parramatta when t he pilot
...._ noticed the carburettor air temperature
needle creeping towards the yellow arc of the
dial. He applied carby heat momentarily until the
needle returned to the green sector.
About t hree minutes later, the engine ran
roughly and then stopped altogether. There was
no time to apply carby heat or to complete
trouble checks.
The pilot was familiar with the area and could
see two football fields about one kilometer distant which he knew were free of power lines and
obstructions.
He chose the larger of the two fields and carried
out a rather good autorotative landing without
the benefit of the hy draulic assist to the flight
controls.
He touched down with little forward speed and
there was nil damage to t he pilot, aircraft,
passengers or property on the ground.
Conditions were:
Visibility ... . . ... . ..... . . . . .. . ..... . . 25 km
Wind velocity .. . ... . .. . . . . . .. .. .. . .. SW/2 kt
Cloud ... ........ . . . .. . . ... .. . . 1 octa 2500 ft
Temperature .. . .. .. .. . .. . . . . .. . dry bulb 17 °C
wet bulb 15.5 °C
Relative Humidity (plotted from the
wet and dry bulb temperatures) . . . . .... . .. . 85 %
When these environmental conditions were plotted on t he Carburettor Icing - Probability Chart
the conditions were just outside the 'serious icing
- any power' range but in the 'moderate icing cruise power' or 'serious icing - descent power'
range.
The Bell 4 7 is susceptible to carby icing and
under the circumstances, the short application of
carby heat was insufficient to prevent the buildup recurring.
The pilot then carried out a copy-book forced la nding under difficult circumstances.
• use carby heat for some t ime b efore reducing
power for a descent if you suspect the conditions are suitable for icing - and leave it on
for the descent. If you have a low power setting warm the engine every 1000 feet of
descent altitude - both for CHT and carby
icing considerations;
• if conditions in the circuit are suspect, select
carby heat on for a while on downwind and
leave it on for base and final - being prepared
to select it off for a go round.
HOW DO YOU KNOW I F THE CONDITIONS
ARE FAVOURABLE FOR CARBY ICING?
There isn't a display of Relative Humidit y in the
cockpit but many aircraft do have a carby air
temperature gauge. You can ask the Met man or
the Tower can give you wet and dry bulb
temperatures. If the wet bulb is close to the dry
bulb it means there is lit tle evaporation - hence
high humidity.
With temperatures or relative humidity, you can
use the chart to very accurately predict the probability of carby icing.
In the absen ce of these details (and in most cases
you can't obtain this information for your location and operating altit udes), you have to rely on
your senses - if it feels damp or humid or there
is visible moisture such as fog or mist, drizzle or
rain, then the relative humidity is high enough
for carby icing. If the t emperature is low or dropping then watch out. Be alert for rough running,
MAP or rpm drop and check the system
thoroughly before t akeoff.
Particularly, be aware of the correct procedures
for your aircraft type - some engine installations are far more vulnerable to carby icing than
others. If in doubt use full carby heat at any
time that you think icing may be present and
then select it off if you need full power - e.g. for
takeoff or go-around 0
�Aviation Safety Digest
AviationSafety Digest
132
132
Flappery will
get you
everywhere
Too much?
A
T THE COMPLETION of a local pleasure
flight, the pilot decided to carry out three
practice circuits. The first two landings were
without incident but on the third landing, the aircraft touched down on the right mainwheel,
bounced and rolled to the right. The pilot applied
power and left aileron but on noticing the skidball, also applied right rudder. By this time the
· bank angle had increased to the extent that the
right wing touched the ground. The aircraft
cartwheeled and came to rest inverted. The
occupants scrambled clear.
The landing was attempted in gusty crosswind
conditions and the pilot had used full flap.
Cessna recommends minimum flap be used in
these circumstances.
In this case the problem was compounded by the
pilot's use of rudder during the bounce but nevertheless, the situation may not have deteriorated
to the same extent if flap was limited. In the
C150, full flap also seriously affects the performance in an attempted go-around.
Too much -
too late?
During the takeoff roll, the pilot noticed a loss of
performance but judged that there was insufficient strip remaini;ng to stop the aircraft. He
continued the takeoff and shortly after liftoff the
aircraft's tail assembly struck the top wooden
railing of a bridge.
Under the circumstances the pilot could not take
any avoiding action and the left wingtip struck a
dead tree. The aircraft slewed to the left, touched
down and came to rest with the engine and landing gear torn from the fuselage.
No fault could be found with the aircraft or
systems which would account for the loss of performance. The takeoff, from a one-way strip, was
done with a slight tailwind component and the
estimated takeoff weight slightly exceeded the
published climb weight limit.
The aircraft had taken off previously with a
similar load but on this occasion it had also been
refuelled and there was a tailwind. The available
strip length was not enough for the aircraft at
this weight, with any tailwind at all. The pilot's
technique was to progressively select full flap
during the takeoff roll from the point when the
tail wanted to lift. After liftoff, he then reduced
the flap setting progressively to allow the aircraft to accelerate.
On this occasion the combination of factors was
sufficient to degrade the aircraft's performance
and to cause it to hit the bridge.
Comments heard in the Bar:
'Don't use flaps in a strong cross-wind.'
'Retract the flaps immediately after touchdown.'
'Lower the flaps at liftoff speed. '
'Don't go around with flaps down.'
'Retract the flaps before liftoff on a
touch-and-go.'
'Don't use more than takeoff flap if it's gusty.'
'Don't use flaps on takeoff at all.'
Where do we start to determine the correct way
to employ flaps? It is like every fundamental of
flying - there is no right and wrong way that
applies equally to all types of aircraft and all
circumstances.
For a start, 'flaps ain't flaps'. There are many
types of flap, each with its own advantages and
disadvantages. Let's consider a few common ones
and their typical characteristics:
Simple Flaps. The simple flap is a trailing-edge
section of the wing which hinges downwards, e.g.
the Chipmunk. The first 20 degrees or so of
travel is primarily lift-increasing with little drag
penalty and little attitude change. There may be
some, usually slight, trim change with this movement. Further travel gives a further increase in
lift but a greater increase in drag. The attitude
change is more pronounced, as is the trim
change.
Split Flaps. The split flap is one whereby only
the lower segment of the trailing-edge section
lowers. That is, the upper wing skin remains
undisturbed, e.g. the Dakota. The lift change is
not as marked as the simple flap but the drag at
high deflection angles is significant. The attitude
change is only marked in a glide but the required
power increase is noticeable. Trim change is
usually slight.
Slotted Flaps. The slotted flap is a simple flap
which encourages the passage of air through the
slot between the main-plane and the flap. It is
more efficient in terms of high values of lift at
high angles of attack. The change in stalling
speed is greater than with simple or split flaps.
The attitude change is more marked also. Trim
change can be pronounced.
Fowler Flaps. The Fowler flap uses a displaced
hinge or screw-jack to extend the flap rearwards
as well as deflecting it downwards. The result is
an increase in wing area as well as an increase in
camber. The consequent lift increase is ~on
siderable and the drag is high at high deflection
angles.
Complex Flaps. Complex flaps are a combination
of the previously described flaps, the most common being the double or triple slotted flap and
the combined slotted and Fowler flap. The
modern airliner generally has double slotted
Fowler flaps. The increase in lift co-efficient is in
the order of 120 per cent. They are usually combined with leading-edge Kruger flaps. By combining the leading and trailing-edge devices the
resultant trim and attitude change is usually
small.
What is the flap primarily for?
Increased lift?
Increased drag?
Increased forward view?
Increased margin over the stall?
Increased descent angle?
Increased thrust required?
All of the above?
In the context of normal operations the flaps
have several purposes. For takeoff their primary
contribution is increased lift for the least possible
increase in drag. Increased lift allows lower liftoff
speed and shorter ground-roll. Increased lift
means greater margin over the stall. Flaps allow
an increased lift at a lower pitch attitude and so
the forward view is improved and the deck angle
is less dramatic (leading-edge devices have the
converse effect). However, the benefits in terms
of takeoff distance have to be offset by any
increase in drag and hence reduction in excess
thrust.
For the approach, flaps allow a lower nose
attitude and hence improved view (compared to a
flapless approach). Any drag increase results in a
steeper glide-path and hence improved obstacle
clearance. Increased lift provides a lower
approach speed and a greater margin above the
stall. The increased drag requires that a higher
thrust be maintained on finals. (This is beneficial
for turbo-jets in particular as it provides better
engine response and hence quicker acceleration.)
On landing the extra lift is unfavourable as it
reduces the weight on the wheels and hence braking efficiency and at any given speed, the aircraft
is more sensitive to gusts. Any drag is favourable
in reducing the landing roll.
In summary:
• for takeoff the flaps should provide the most
lift increase for the least drag increase;
• for the approach the flaps should provide both
increased lift and increased drag; and
• for the landing-roll the flaps should provide a
maximum of drag and preferably a reduction
in lift.
�Aviation Safety Digest
Aviation Safety Digest
132
132
The arguments
Takeoff The first stage of flap gives an increase
in lift for little drag. The lift/drag ratio, however
is reduced slightly. So theoretically the drag
'
increase is penalising and offsets the advantage
offered by the lower liftoff speed. The margin
above the stall is improved if we still climb at
the no-flap speed (l.2XVs) and the lower nose
attitude allows a better view. For a short-field
takeoff where the lowest possible liftoff speed
and lowest possible stall speed is required, the
flap benefits outweigh the disadvantages. The
reason some manufacturers recommend the use
of nil flap for takeoff is usually because, in their
particular case, the advantages are slight and the
limitations, perhaps due to the trim change on
retraction or the risk of exceeding the flap·
limiting speed or the risk of stone damage to the
flaps, are more significant. In the case of twins,
there are also considerations regarding the singleengine climb performance.
~pproach.
During the approach, lift and drag
mcreases are both favourable. Most flap should
deploy~d ~~ to the point where the drag
mcrease s1gn1f1cantly exceeds the lift increase. In
gusty or strong crosswinds high flap deflections
are .fa':ourable up to the point where they may
preJudice lateral control response. Leading-edge
devices are favourable in this context.
Landing. After landing the maximum drag is
required and the least lift. If the aircraft has
~igh flap deflection angles available then full flap
is best - again provided there is no adverse
lateral control effect. If only small angles are
available then it is a compromise as to whether
th~ lift reduction and improved braking (more
weight on the wheels) outweighs the reduced
drag. At very low speed it certainly would.
?e
Conclusions
There is no universal guide to the optimum use
o.f flaps. The only tested and proven configuration and technique for each aircraft is described
in the flight manual. Use t he recommended setting for takeoff and retract them with caution.
For approach, use an intermediate setting until
committed to land and then select full flap unless the conditions are unsuitable for the use
of full flap in the particular aircraft. (As a
general rule I try tq use full flap for all landings.)
If there is a chance that you may have to go
around or if the conditions are such that the
lateral control of your aircraft may be affected,
delay or don't use full flap. If the landing
distance available is such that you require full
flap in conditions that cause handling problems,
then delay your landing or go somewhere else.
One~ you ~re saf~ly on the ground leave the flap
settmg as is, until you come to a virtual stop and double-check that it is the flap lever you are
about to select UP! The retraction of flap during
landing roll is fraught with peril, although I
know that in some aircraft it is necessary for
touch-and-go's - but that's another story O
NVMCCurrency
HE AIRCRAFT arrived overhead the
· destination strip about 40 minutes after last
_ light. Weather conditions in the area were
good, with light winds and clear skies. However
the night was very dark and there was no visibl~
horizon. The lights of the nearby town, the flarepath and nearby farms were clearly visible.
Witnesses on the ground reported that the air·
craft seemed to be at normal height o'n the cross·
wind leg and at the start of the downwind leg.
It was then seen to enter a gradual but steady
desc~nt. About half-way along the downwind leg,
the lights of the aircraft were lost to sight. The
aircraft impacted the ground in a straight-andlevel attitude and bounced and skidded for 350
metres. Injuries varied from minor to serious.
From the statements made, no-one was aware of
anything untoward before impact. Nothing was
found wrong with the aircraft or systems.
The pilot had not flown at night for some 11
months and only twice in the previous 32
months. On each of those occasions he only made
one landing.
It appears that having reduced power and
lowered the undercarriage, the pilot was concentrating so much on the flare path that he did not
re-introduce power nor did he properly scan the
instruments. The aircraft simply 'settled' onto
the ground.
A pilot who flies without recent experience is
taking a risk. The longer the period, the greater
is the risk. A pilot who carries passengers under
these circumstances is irresponsible. The NVMC
currency requirements were framed to keep the
risks within bounds - please observe them 0
The best-laid
plans .. .
Richard Sherer is a ;ourna/ist in the Public Relations
Branch of the Department and is an active GA pilot.
HINGS GENERALLY quieten down at
Sydney Airport briefing office as the night
wears on and large RPT jets are safely
curfewed. The briefing officer has time to care·
fully go through the relevant NOTAMS, particularly those affecting runway lengths due to
nocturnal works-in-progress.
The forecaster had been very helpful, allaying my
fears that the coastal cloud I had squeezed under
on the way into Sydney may prevent a nightVMC return to Canberra. Both Sydney and my
destination were forecast and I was told were
actually CAVOK.
It was a great night for flying and I was soon
radar-vectored to intercept my planned outbound
track. It was just after midnight and while I
wasn't particularly tired, I was looking forward
to getting home after a long day.
I could see the lights of Canberra from a good 30
miles out and the aerodrome beacon quickly pinpointed my destination.
It was then that I noticed the first warning
signs; there appeared to be a slight haze diffusing the lights of some of the small settlements
near my track. I wasn't concerned as the
Canberra controller had previously mentioned the
likelihood of smoke haze in the area. I heard
Approach talking to another aicraft closer in,
who was apparently having some trouble locating
the field. Shortly after, the controller reported
the possibility of some fog patches in the area
that they should dissipate quickly. After all,
it was late October and the surface temperature
was plus 9 degrees Celsius.
But things rapidly deteriorated. The other aircraft managed to land with some difficulty, after
being radar-vectored onto an ILS approach.
There were fog patches along both runways and
the pilot commented that the Airport would
probably soon have to close.
The controller advised that the fog was persisting and that I would have to divert. I decided
to try Goulburn because it was the closest air·
field and because it had looked clear when I had
passed 20 minutes previously.
By this time, the length of the day was beginning to take its toll. I reluctantly turned away
?ut
from Canberra and tracked in a northerly direction. I was maintaining a safe altitude and I
started drifting eastwards. The controller
suggested a heading correction.
I found Goulburn by its NDB and I triggered the
PAL lighting. It confirmed what I was already
beginning to fear - there was fog there too.
I reported this to Flight Service who asked for
my endurance and undertook to locate a suitable
fog-free landing place. It was getting rather late '
at night to be doing mental arithmetic, and while
continuing to head north past Goulburn I
calculated that I had about 80 minutes of fuel
remaining.
The FS officer came back a few minutes later and
said what I hoped he wouldn't - that I should
return to Sydney. He asked for an ETA. My
mental calculations were getting worse and I
gave a time interval of 75 minutes - fortunately
he questioned this figure and asked me to turn
on the transponder. Sure enough, by now I was
only 75 miles from Sydney with an ETI of 45
minutes.
The FSO kindly phoned my wife to explain what
~ad been happening. I was happy to see the
hghts of Sydney and even happier to see the
lights of runway 34 jutting out into Botany Bay.
I landed and taxied in without incident although
Murphy made sure the landing light was UIS.
It was now 2.30 am local.
I had some sleep in the aircraft and some more in
the nearby commuter lounge, conscious that I
would have to depart early to return the aircraft
to Canberra in time for its next booking. No such
luck - the fog was there to stay and wasn't
expected to lift until after 11.00 am local.
I refuelled the aircraft and only then did it dawn
on me how close I had come. A PA28-151 takes
1.80 litres of fuel. The refueller had put in 158
htres. I was less than half an hour (or a stiff
headwind) from fuel exhaustion and yet I had
taken off with all the required reserves including
30 minutes holding and I had a further 20
minutes spare.
I was on my way again about two hours later
and my second flight was notable only for the
eternity which it seemed to take. I had made two
complete return trips in the space of nine hours.
Conclusions
Time may fly when you're having fun but flying
when you 're tired isn't fun. I wasn't really aware
of fatigue until, ·with a mixture of resignation
and mild annoyance, I was turned away from my
destination.
From that point, I was in a mood and condition
to do only the minimum necessary to get safely
onto the ground somewhere - anywhere. I was
flying almost automatically, even to the extent of
relying on Flight Service and ATC to sort out
problems such as the endurance of both the aircraft and myself and to point me in the right
direction.
Thankfully they did just that O
�If you are not eligible fo r a free issue, or if you wou ld like addit ional cop ies o f the Digest: -
Passengers rights
Ass PASSENGER you ARE entitled to ask
your pilot:
• have you checked the weight and balance of
the aircraft?
• have you checked the takeoff and landing performance charts for the aircraft at this weight
and for the airfields concerned?
• have you obtained a weather forecast?
• have you submitted a flight plan?
• are you correctly licensed, rated and current
for this flight? e.g. are you qualified to fly in
cloud?
• is the aircraft fully serviceable?
• are you fully serviceable and within duty time
limits?
• are you carrying a Locator Beacon and survival equipment?
• should I make alternative transportation arrangements or delay commitments to allow for
weather problems?
Five iSSUeS $A 16. 00
or over thi rty years , the Aviation Safety
Digest has been an integral part of
Austral ian aviation .
As a PASSENGER your ARE NOT entitled to
ask your pilot:
• to carry a payload beyond the weight and
balance limits of the aircraft
• to take off or land at an airstrip which is less
than the length required by t he aircraft at that
weight
• to fly below the legal minimum altitude
• to fly beyond his or her licence, rating or currency limitations, particularly with respect to
weather
• to fly beyond the pilot's duty time limits
• to take unreasonable risks by continuing a
flight for the sake of meeting your prior commitments.
In July 1986, responsibility for the Digest was
transferred from the Bureau of Air Safety
Investigation to the Fl ight Standards Division
of the Australian Department of Aviation . This
move ·reflected the perception that civil
aviation may have reached the lim it of accident prevention th rough regulation and that
the way forward is th rough increased
emphasis on safety education in general, and
the 'human factor ' in particular. Rather than
just draw lessons from accident investigations, the Digest wil l inc reasingly seek to in-
onc1udingsudacepos1age1
fluence pi lot behaviour by positive reinforcement of sound techniques. It will examine all
aspects of pi loting and publish formal results
as well as 'the tricks of the trade'. The 'crash
comic ' will become a 'how not to crash '
comic.
Anyone with an interest in aviation will benefit
from tapping into this un ique sou rce of the
accumulated wisdom of the profession and
the latest research into aviation safety in
Australia. Indeed, anyone with an interest in
high technology and the roles and limitations
of the human operator wi ll find th is publication en lightening.
------------------------------------------~-
Feeling a little query?
The AIRFLOW column is intended to promote discussion on topics relat ing to av iation safety. Inp ut from student pilots and
flying inst ructors is particularly welcome.
Anonymity wi ll be respected if requested.
'Immunity' applies with respect to any
self-c onfessed infringements that are
highlighted for the benefit of others.
Write to:
AIRFLOW
Aviation Safety Digest
G.P.O. Box 367
CANBERRA A.C.T. 2601
Austral ia
Aviation Safety Digest 132 I i
�~
Aircraft accident reports
AGPS
fourth quarter 1986
Send to:
The following information has been extracted from accident data files maintained by the Bureau of Air
Safety Investigation. The intent of publishing these reports is to make available information on
Australian aircraft accidents from which the reader can gain an awareness of the circumstances and
conditions which led to the occurrence.
Mail Order Sales
Australian Government Publishing Se rvice
G.P.O. Box 84
CANBERRA A.C.T. 2601
At the time of publication many of the accidents are still under investigation and the information
contained in those reports must be considered as preliminary in nature and possibly subject to
amendment when the investigation is finalised.
I wish to subscribe to . ...... copies of Aviation Safety Digest for five issues at $16.00,
including surface postage in Australia and overseas.
Readers should note that the information is provided to promote aviation safety - in no case is it
intended to imply blame or liability.
Preliminary data indicate aircraft type, location of accident, month and year, category of flying, pilot
licence and rating, and total hours.
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. ..... ..... ..... . . ....... .. .... .. .. ·....... ............... Postcode
Preliminary reports
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The following accidents are still under
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I enclose my cheque/money order for $ .. . ... . . ... ..... .. ....... .. payable to AGPS
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-~------------------------------------------'
Dear Si r,
Fixed Wing
Piper PA24-260, VH·MCW, Toowoomba Qld., 22 Nov. 86,
Non-commercial - pleasure.
While taxiing before takeoff, the pilot established two-way
communications with Brisbane Flight Service Unit. After
takeoff, the pilot attempted unsuccessfully to pass his depar·
ture message and checks revealed that the aircraft had suf·
fered an electrical failure. The pilot elected to return to
Toowoomba and en route noticed that the radio operated
intermittently. He selected the gear down and stated that he
observed the 'Gear down and locked' indicator light
illu.m inate momentarily and believes he heard the gear motor
run. The aircraft was subsequently landed gear up.
Inspection of the aircraft revealed that the connector for the
earth battery strap was broken.
Cessna 172-N, VH·MJJ, Toowoomba Qld., (f1 Dec. 86,
Non·commercial - pleasure.
The pilot had taken part in a flour bombing and balloon
bursting competition and was returning to land. The front
seat passenger was a flying instructor and was acting as a
safety pilot and judge for the competition. The approach to
land was high but the pilot decided to continue and the air·
craft touched down about 600 metres beyond the runway
threshold, and bounced. The pilot applied some power and
continued with the landing attempt, but the stall warning
sounded. The front seat passenger instructed the pilot to
apply full power and to lower the nose of the aircraft. He
then placed his hands on the controls to monitor the pilot's
control inputs. The aircraft flew along the strip about a
metre above the ground before striking t he airfield boundary
fence and coming to rest 160 metres beyond the fence.
Yours sincerely, . . . ... .. . . . ... .. ..... ............. .. ...... . .......... .. ... .
Name: . .. . . ...... ... .. .... ... . . ........ . .. . . . . ... .. . .... .... ... . . ...... . .
Address: ...... . .. . . . . . ..... . .... . . . . .... . . .. .. . . . .. . . . .... .. . .. . ... ..... .
Details to be published?
D
No name
ii I Aviation Safety Digest 132
0
Initials okay
D
Full name okay
Piper PA25-235, VH-SEG, Ingham Qld., 15 Dec. 86, Aerial
agriculture.
The pilot was engaged in the spraying of sugar cane. During
one of the swath runs, as he turned the aircraft to follow the
line of the cane, the right wing struck the cane. The aircraft
impacted the ground and bounced several times before com·
ing to rest.
Cessna 172-M, VH-WTL, Boulia Qld., 16 Dec. 86,
Non·commercial - pleasure.
The pilot landed the aircraft on a nine-metre wide gravel
road to check on one of his staff working nearby. Following
the check, the pilot commenced a takeoff towards the west in
10·15 knot northern wind. At an indicated airspeed of about
40 knots, the aircraft drifted to the left, off the side of t he
road. The pilot continued with the takeoff attempt but the
aircraft continued to turn to the left, downwind, and travel·
led about 600 metres before the nosewheel entered a ditch
and the aircraft overturned.
Cessna 182-F, VH·DIJ, Charters Tower, 14 Dec. 86,
Non-commercial - pleasure.
The pilot reported that while he was conducting a landing at
his property strip, a call and cow ran onto and along the
strip. To avoid the animals, he decided to delay any further
descent until the aircraft had passed the animals. However,
when the aircraft was about 15 feet above the strip, the nose
dropped and the nosewheel struck the ground, resulting in
damage to the firewall, engine mounts and the cabin floor.
Cessna 182-F, VH-TWM, Gibberland Mine, 22 Dec. 86,
Non-commercial - pleasure.
Shortly after takeoff, the pilot heard a noise and noticed two
holes appear in the engine cowl. The airspeed began to
decrease and the aircraft landed, bouncing twice before
nosing over and coming to rest 50 metres beyond the end of
the strip. Both propeller blades had been dislodged from the
aircraft. One was located 80 metres to the left of the strip
and the other, with hub and constant speed unit attached,
was located 40 metres to the right of the strip.
Piper PAlS..125/Al, VH·HCM, Redcliffe Qld., 22 Dec. 86,
Instructional - dual.
The student had completed about seven hours training and
was undergoing her second session of circuit training. The
instructor stated that the student had previously had dif·
ficulty with the directional control of the aircraft. On this
takeoff he allowed the student to manipulate only the
rudder, so that she could concentrate on the directional con·
trol aspect, while he manipulated all the other controls. As
the power was increased the aircraft gradually swung to the
left. Approaching the left side of the strip the swing
increased and the instructor applied right rudder at t he same
time as the student. The aircraft swung to the right and as it
left the right side of the strip, the left wheel dug into the
ground and the aircraft tipped onto the left wing.
Aviation Safety Digest 132 I iii
�Piper PA34-220T, VH-FYU, Coolangatta Qld., 29 Dec. 86,
Non·commercial - pleasure.
When the pilot selected the landing gear up after takeoff, the
gear unsafe light remained on. Recycling the gear had no
effect. The pilot continued to his planned destination, with
the aircraft performing at about 10 knots below the expected
speed. On arrival, a visual inspection confirmed that the
right maingear was trailing. The pilot then carried out a successful emergency landing, during which the right flap anrl
propeller sustained damage as the gear collapsed.
Piper PA24-250, VH-GED, Moree N.S.W., 11 Oct. 86,
Non-commercial - pleasure.
The aircraft normally used by the pilot was unserviceable
and he had obtained the use of the PA24, a type he had not
flown for about three years. The initial leg of the flight was
uneventful but the departure for the return journey had been
delayed and the aircraft arrived at the destination at about
last light. When the gear was selected down, a complete electrical failure occurred. The pilot was unable to read the
instructions for manual lowering of the gear, which were
printed on a cover on the cockpit floor, because there was
not a torch available. He therefore decided to land as soon as
possible as the grass strip selected was not lit. The landing
was made about 10 minutes after last light and the aircraft
slid for about 60 metres before coming to rest on the strip.
Bellanca 7-ECA, VH-SLO, Bankstown N.S.W., 12 Oct. 86,
Non-commercial - pleasure.
The pilot reported that gusty and turbulent conditions
existed as he made his landing approach. During the flare
the aircraft ballooned to about 10 feet, and after the sub·
sequent touchdown the aircraft veered to the left before coming to rest on its nose and left wingtip.
Cessna 172-N, VH-BEM, Goulbum N.S.W., 25 Oct. 86,
Instructional - solo (supervised).
The pilot was conducting a solo navigation exercise which
involved an en route landing. Turbulence was encountered
during the latter stages of the landing approach and a heavy
touchdown occurred. The aircraft bounced and again touched
down heavily before the pilot was able to regain control of
the landing. After taxiing to the parking area, the pilot
discovered damage to the nosegear leg and adjacent structure.
Cessna 172-N, VH-IXK, Nymagee N.S.W., 08 Nov. 86,
Non-commercial - pleasure.
The surface of the particular ALA was covered with long
grass and areas of low scrub and bushes. The pilot taxied
along one of the strips until he came to an area of thicker
scrub and saw markers which he believed defined the end of
the strip. During the takeoff roll, the aircraft had reached a
speed of about 50 knots when the pilot realised that he was
approaching the upwind end of the strip. He abandoned the
takeoff and attempted to steer the aircraft through a gate in
the boundary fence. However, the left wing and mainwheel
struck the gate post, the aircraft slewed rapidly and the
nosegear collapsed. The pilot later advised that he had begun
the takeoff from the intersection of the two flight stips and
had confused markers on the other strip for those at the end
of the strip selected. As a result, the length available had
been only 400 metres, compared with the full-strip length of
680 metres.
Air Tractor AT-301, VH-FRP, Collymongle N.S.W., 19 Nov.
86, Aerial agriculture.
The pilot was performing a takeoff in crosswind conditions of
about 15 knots. When the aircraft had reached a speed of
about 40 knots, it suddenly veered to the left and, despite
corrective action, the pilot was unable to maintain directional
control. With full power still applied, the aircraft ran off the
side of the strip. It then passed over an embankment and
travelled a further 200 metres before colliding with trees
which were some 60 metres from the edge of the strip.
iv I Aviation Safety Digest 132
L
Beech B58, VH-PGQ, Canberra A.C.T., 29 Nov. 86,
Non-commercial - pleasure.
On arrival at the destination, the pilot selected the landing
gear down. Almost immediately afterwards, the radio frequency indicators faded and a strong burning smell became
evident. The pilot carried out a go-around, during which
radio communications were lost and the burning smell
became stronger. The pilot attempted to lower the gear with
the emergency system but found he was unable to move the
manual extension handle. Under the circumstances, he
elected to land as soon as possible. The aircraft touched
down on the runway, with the gear partially extended, and
slid for about 200 metres before corning to rest.
Cessna 207, VH-UBX, Wilton N.S.W., 21 Dec. 86, Sport
parachuting (not associated with an airshow).
A student parachutist was exiting the aircraft for a static
line jump when portion of the main canopy became entangled
around the right horizontal stabiliser. Approximately half
the right elevator was torn away, together with portion of
the trim tab, while the outer section of the stabiliser was
bent downwards through 45 degrees. The parachutist landed
safely and the jump instructor then made a normal descent.
The pilot was able to retain control of the aircraft and
elected to divert to a more suitable aerodrome, where an
uneventful landing was subsequently carried out.
De Havilland C2, VH-AAY, Walcha N.S.W., 22 Dec. 86,
Aerial agriculture.
Superphosphate spreading was being carried out, with the
aircraft uplifting one-tonne loads about each six minutes.
Fuel endurance with both tanks full was approximately two
hours. The pilot was conducting his 25th takeoff for the day,
about one hour after refuelling. Witnesses observed that the
aircraft did not become airborne at the usual point, twothirds of the way along the 675-metre strip. Liftoff finally
occurred at the end of the strip, but almost immediately
afterwards the aircraft clipped a fence. It was seen to sink
slightly, before climbing at a steeper-than-normal angle, until
some 250 metres beyond the fence. At this point, the nose
dropped suddenly and the aircraft dived into rising ground in
a steep nosedown attitude. Fire broke out on impact and con·
sumed much of the wreckage. Preliminary investigation
revealed that the fuel selector was in the 'off' position.
Pitts Sl, VH-WIZ, Leongatha Vic., 12 Oct. 86, Air Show/air
racing/air trials.
The pilot was flying one of three similar aircraft in practice
for a forthcoming aerobatic display. The three aircraft car·
ried out a stream landing, with the pilot of the subject aircraft intending to land to the left of the centre of the strip.
Shortly after a normal touchdown, the aircraft encountered a
soft area of the strip and subsequently overturned, coming
to rest 85 metres from the initial point of touchdown. The
display team had had no prior indication of any soft areas on
the strip surface.
Piper PA28-161, VH-BZA, Lilydale Vic., 26 Oct. 86,
Non-commercial - pleasure.
The surface of the 795-metre strip was covered in long erass.
The pilot noted that acceleration for takeoff was less than
normal, and the aircraft took about 400 metres to achieve a
speed of 45 knots. At this point, the pilot considered that he
was committed to takeoff, and towards the end of the strip
he attempted to force the aircraft into the air. The aircraft
struck an embankment at the end of the strip, crossed a
road, and collided with a fence before coming to rest about
200 metres further on.
Cessna 172-N, VH-WSI, Harewood Vic., 30 Oct. 86,
Instructional - solo (supervised).
The pilot had been conducting a series of solo circuits and
landings. On the seventh circuit, a normal approach was
flown but the aircraft ballooned slightly as the flare was
commenced. The aircraft was then seen to climb abruptly to
a height of about 20 feet, and shortly afterwards the left
wing dropped. Full power was applied but the descent continued and the left wingtip struck the ground. The aircraft
s lewed rapidly to the left and the nose struck the side of a
ditch.
Piper PA32-260, VH-FIC, Moorabbin Vic., 31 Oct. 86,
Instructional - dual.
The student had been practising circuits with touch-and-go
landings for about 75 minutes. An approach was then made
for a full-stop landing. The aircraft was flared too high and it
subsequently touched down heavily and bounced. The
instructor took control and landed the aircraft, but the left
wing lowered until it touched the ground. After vacating the
aircraft, the crew discovered that the left maingear torque
bolt had failed, allowing the wheel and oleo assembly to fall
clear of the strut during the bounce.
Piper PA25-235/Al, VH-FAU, Hopetoun Vic., 06 Nov. 86,
Aerial agriculture.
The pilot was conducting spraying operations on a pea crop.
Swatch runs were being made at right angles to a power line
and low trees which were located just beyond the end of the
crop. On the final run, the aircraft was flown beneath the
power line, but the right wing then struck the top branches
of a dead tree. The aircraft was seen to climb to about 200
feet before descending steeply and striking the ground some
370 metres beyond the point of collision with the tree. A
fierce fire broke out on impact and engulfed the wreckage.
Transavia PL12, VH-MYH, Mirboo Nth. Vic., 07 Nov. 86,
Aerial agriculture.
Before departing from his home base for his first operation
from the particular agricultural strip, the pilot had been
briefed not to land down the slope unless there was a strong
headwind component favouring that direction. A normal
landing was made and the pilot was then given details of the
task to be performed. He departed for an aerial inspection of
the area and on return noted that there appeared to be a
headwind of about 25 knots for landing down the slope.
However, on late final approach to land in this direction, the
pilot realised that the wind strength had decreased to about
10 knots. He continued with the landing but was unable to
avoid overrunning the end of the strip. A groundloop was
initiated during which the left gear assembly collapsed.
Grumman 0159-B, VH-LTM, Mangalore Vic., 20 Nov . 86,
Non-commercial - practice.
The crew was conducting a series of circuits and landings.
The check-pilot was sitting in the right-hand control seat and
was holding the checklist. During the circuit in question, the
check-pilot spent a considerable amount of time discussing
various aspects of the aircraft operation. There was further
cockpit talk during the final approach and neither pilot
realised that the landing gear had not been lowered. The air·
craft slid on its belly for some 360 metres after touchdown.
Piper PA25-235, VH-SKJ, Horsham Vic., 29 Nov. 86, Aerial
agriculture.
The pilot was conducting spraying operations over an
irregularly shaped paddock. Power lines were located along
two sides of the paddock. At the end of a clean-up run conducted parallel to one set of the lines, the aircraft struck and
severed two wires which crossed its path. It then yawed
sharply and collided with the other wires before impacting
the ground in a steep nosedown attitude. During the ensuing
s hort ground slide, both the engine and the rubber fuel tank
were torn out. The pilot advised that he had been aware of
the power lines but had temporarily overlooked their
presence.
Cessna Al88-Al, VH-DGO, Boort Vic., 29 Nov. 86, Aerial
agriculture.
The pilot was spraying a crop with liquid fungicide. As he
pulled up to clear trees during the third swath run, the
fungicide evidently surged in the hopper and a quantity
escaped past the hopper-lid seal. It then splashed over the
windscreen, severly restricting the pilot's forward vision. He
elected to return to the strip to clean the screen and check
the hopper seal. The strip length was about 1000 metres and
the pilot did not consider it necessary to dump the remainder
of the load. During the landing, which was made in light
downwind conditions, the pilot experienced difficulty in seeing the strip. During the latter stages of the ground roll, the
aircraft began to veer to the right. Corrective action failed to
redress the situation and the right wing struck the fence
bordering the strip. The aircraft came to rest after sliding
sideways into a ditch alongside the fence, some 315 metres
from the point of touchdown.
Auster J-1, VH-AMK, Three Hummock Island, 07 Dec. 86,
Non-commercial - pleasure.
The pilot was attempting to take off on a wet strip which
sloped markedly down from the centre towards each end. To
minimise the effect of a slight tailwind, and to avoid an
obstruction at the end of the strip, the pilot planned to angle
the ground run. Takeoff was commenced from the left side of
the strip but when the aircraft had reached the top of the
hump in the strip, the pilot realised that he had angled the
run excessively and was now outside the markers on the
right side. The aircraft subsequently collided with scrub and
overturned.
Piper PA28-161, VH-BZB, Lilydale Vic., 08 Dec. 86, Ferry.
After conducting a thorough preflight inspection, the pilot
prepared to ferry the aircraft to a maintenance organisation
which was to perform a scheduled inspection. The aircraft
performed normally until it reached a height of about 200
feet after takeoff. At this point, the engine lost a substantial
amount of power and the pilot was committed to a forced
landing. During the landing roll, the aircraft collided with a
fence and came to rest in the adjacent paddock. Initial
inspection revealed that there was a serious leakage of fuel
past the fuel filter bowl seal and it was likely that the defective seal had allowed air to enter the fuel system.
Piper P A32-300, VH-CLF, Melbourne Vic., 09 Dec. 86,
Non-commercial - pleasure.
Prior to departure, the pilot had been made aware of a
Notam advising pilots to disregard temporary displaced
threshold markings for runway 27 at the destination. During
the subsequent approach, the pilot noticed red and white
lighting and associated this with the displaced threshold. It
was his intention to land beyond these lights, which were in
fact the runway approach lights. Very late in the approach
the pilot realised he was too low, but before power could be
applied the aircraft struck the lights, 120 metres short of the
runway. The maingear legs were torn off and the nosegear
collapsed before the aircraft slid to a halt on the side of the
runway.
Piper PA25-235/Al, VH-FAN, Horsham Vic., 28 Nov. 86,
Aerial agriculture.
Spraying runs were being conducted over a paddock which
had power lines along one boundary. The pilot had been
passing beneath the lines during each run; however, after
completing about two-thirds of the task, the wire deflector
on the aircraft snagged and broke the powerline. The pilot
carried out a precautionary landing and discovered that the
rudder of the aircraft had been substantially damaged by the
wire strike.
Bushby Ml, VH-JBR, Koo-wee-rup, 28 Dec. 86,
Non-commercial - pleasure.
The pilot was making a takeoff in 15 knot crosswind conditions. Initial acceleration appeared to be normal and the aircraft lifted off at 60 knots. However, about 30 metres further
Aviation Safety Digest 132 Iv
�The pilot was probably concerned because two other aircraft
were approaching to use the same runway, and she perceived
a need to vacate the area at the first taxiway. Witnesses
reported that the aircraft did not flare for touchdown and
that it appeared that the pilot had tried to force it onto the
ground.
Beech C23, VH-UML, Maryborough Qld., 07 Nov. 86,
Instructional - solo (supervised), student, 21 hrs.
The student had been briefed to carry out a series of solo circuits and landings. The instructor observed the first circuit,
and reported that it appeared to be normal. On touchdown,
the aircraft bounced, then pitched nose down. The subsequent touchdown was heavy and the nosegear was torn
off.
The student had accumulated 1.5 hours of solo operations on
four previous flights and had received a dual check on her
last flight, which was eight days prior to the accident. When
the aircraft bounced, she had evidently been unable to take
suitable corrective action to prevent the subsequent heavy
touchdown.
Cessna 15().E, VH-KML, Tundulya N.S.W., 25 Nov. 86,
Non-commercial - pleasure, PPL, 300 hrs.
The pilot had been carrying out a number of flights to strips
in the general area. After completing repairs to a bore pump,
the pilot and passenger prepared to return to the property
homestead, some 20 kilometres to the north. Shortly after
the takeoff roll commenced, the aircraft began to veer to the
right. Full left rudder was progressively applied but directional control could not be maintained. The right wing collided with a number of bushes and saplings alongside the
strip. The aircraft then slewed rapidly to t he right and the
nosegear collapsed.
Investigation revealed that the aircraft had rolled for 104
metres before the right wing struck and broke a small
sapling. This coincided with the initial veer to the right, as
teported by the pilot. As the aircraft diverged from the
centre of the strip, it entered an area of soft loam, which
increased the drag on the right wheel. The scrub struck by
the aircraft had encroached onto the strip, reducing the
width in places to about 15 metres. The pilot had been aware
that the strip had not been cleared of undergrowth for some
21 months.
Gliders
Glasflugel Libelle, VH-GCP, Wyreema Qld., 10 Oct. 86,
Non-commercial - pleasure, Glider, 450 hrs.
Because of deteriorating lift conditions, the pilot elected to
make an outlanding. The paddock selected had been recently
ploughed and the surface was soft. Almost immediately after
touchdown, the glider yawed, then groundlooped through 90
degrees, resulting in a compression fracture of the fuselage.
It was likely that the glider had been affected by a sudden
wind gust shortly after touchdown and the pilot had been
unable to maintain directional control.
This accident was not subject to an on-site investigation.
Schleicher KA-6, VH-GTW, Tumbarumba N.S.W., 06 Dec. 86,
Non-commercial - pleasure, Glider, 205 hrs.
Following a winch launch, the pilot spent 12 to 15 minutes
gliding before returning for a landing. On the downwind leg
he noted that the aircraft appeared to be lower than the
height indicated on the altimeter. At about the base leg position the aircraft was very low and witnesses expected the
glider to land in one of several suitable paddocks. However,
t he pilot continued towards the strip and the glider touched
down during the turn onto final approach. The tail section
was broken off when it contacted the long grass.
The pilot had accumulated most of his gliding experience at
the particular strip and was familiar with the area. The flight
in question was to be the first made by the aircraft since
viii I Aviation Safety Digest 132
L
returning from another aerodrome. During the preflight
inspection the pilot had forgotten to re-set the altimeter to
read zero feet. As a result, the altimeter was over-reading by
some 500 feet. The pilot had concentrated on the indicated
height and had not visually assessed the approach profile.
He was unable to explain why he had persisted with the
approach when he became aware that the aircraft was abnor·
mally low and there were suitable outlanding areas available.
This accident was not subject to an on-site investigation.
Final updates
The investigation of the following
accidents has been completed. The
information is additional to or replaces that
previously printed in the preliminary report
Fixed Wing
Quickie Q200, VH-FMV, Bankstown N.S.W., lO·Oct. 85, PPL,
21.000 hrs.
The aircraft was being flown for the first time. The pilot
stated that after takeoff the aircraft felt very nose heavy
and that he had difficulty in maintaining a nose-up attitude
after liftoff. When he attempted to reset the elevator trim,
the friction nut broke. The back pressure that he was
required to hold with the control column reduced as the
airspeed increased. During the subsequent approach, the
pilot found he had insufficient elevator control available to
flare the aircraft. On touchdown, the aircraft bounced and a
go-around was carried out. The pilot made several other land·
ing attempts but on each occasion the aircraft bounced. On
the final attempt, the aircraft bounced a number of times
before the right canard collapsed and the aircraft ran off the
runway.
The aircraft had been correctly loaded, with the centre of
gravity 14 per cent aft of the forward limit. The angles of
incidence on the wing and the canard were found to be about
0.3 degrees outside the design specifications. It was apparent
that there was a critical relationship between these angles,
the centre of gravity position and the amount of pitch control available. The aircraft manufacturer subsequently recom·
mended a modification to the control system.
Amer Air 5-B, VH-IFS, Birdsville Qld., 05 Sep. 86, None, 200
hrs.
The pilot had held a Private Pilot Licence which had expired
about six months prior to the accident. A witness reported
that after the aircraft touched down it bounced about three
times before landing in a nose·down attitude, which resulted
in the nosegear strut failing in overload.
The landing was attempted in a 10 knot crosswind and the
pilot reported that the aircraft was affected by a wind gust
during the landing sequence. The pilot was not in recent flying practice and had not flown for about five months prior to
this trip.
Cessna 182-R, VH-PJV, Wando Vale Station, 21 Sep. 86,
PPL, 998 hrs.
The pilot stated that the strip used for landing was aligned
into the morning sun. On late final approach, he noticed
several kangaroos near the threshold of the strip and decided
to land beyond the animals. He reported that just as the aircraft was about to touch down, he saw a small kangaroo and
then heard a thump. An inspection of the aircraft revealed
that the animal had been struck by the left tailplane.
This accident was not the subject of an on-site investigation.
Rockwell S2R, VH-LGG, Griffith N.S.W., 24 Jan. 86,
CPUAg. Cl. 1, 9000 hrs.
Shortly after an apparently normal takeoff, engine power
was lost and the pilot was committed to a landing straight
ahead. Initial touchdown was in a flooded rice paddy and the
aircraft then struck a levy bank and ran through a fence,
coming to rest inverted in an adjoining dry paddock.
Investigation revealed that one cylinder head had become
detached from the engine and had removed a section of the
inlet manifold.
The cylinder head had failed as a result of fatigue cracking
which had commenced at the edge of an exhaust valve insert.
Piper PA28-140, VH-WKE, Lennox Head N.S.W., 02 Feb. 86,
PPL, 251 hrs.
While the aircraft was cruising at 2000 feet above mean sea
level the engine commenced to run roughly. Trouble checks
failed to determine the source of rough running and the pilot
elected to land at an en route aerodrome. However, before
reaching this strip, the engine lost power completely and the
pilot was committed to a forced landing. Because of crowds
at an adjacent beach, the pilot attempted to land on a road.
Touchdown was further along the road than expected
because of a strong tailwind component, and the aircraft collided with a kerb before coming to rest. Initial investigation
disclosed a number of mounting stud failures on one cylider,
together with an exhaust valve failure in the same cylinder.
Investigation revealed that nuts on the various bolts and
studs securing the number three cylinder to the crankcase
had evidently not been correctly tightened. Five of the eight
mounting studs/bolts had failed from fatigue during normal
operations, finally allowing the cylinder to become loose. The
engine had completed 83 hours time in service since an
overhaul. There was no logbook record to show whether the
particular cylinder had been removed or replaced since that
overhaul.
Beech 95-B55, VH-APL, Ballina N.S.W., 30 Jun. 86, PPL,
2500 hrs.
During the takeoff roll, the aircraft had reached a speed of
about 85 knots when the left engine suddenly lost power.
The pilot immediately closed both throttles and applied braking but was unable to prevent the aircraft overrunning the
730-metre strip. The landing gear was torn out before the aircraft came to rest. Initial investigation revealed that the
takeoff attempt had been made with the fuel tanks selected
to the auxiliary positions, and these tanks were about onequarter full. It is probable that the fuel ports became
uncovered as a result of the takeoff accleration, allowing the
ingestion of air to the fuel system.
The pilot normally followed a written checklist but had omitted to use it on this occasion. After checking the fuel system
during the before-takeoff vital actions, he had inadvertently
left the fuel selectors on the auxiliary positions.
Cessna U206-G, VH-UFG, Molong N.S.W., 10 Sep. 86,
PPL/Cl. 4, 2398 hrs.
The pilot was making an approach in light wind conditions
to a 600-metre long strip. Undulations on the surface were
such that the slope in the landing direction varied from
about 7 per cent up to 4 per cent down. The pilot was using
a short-field landing technique. Touchdown occurred just
prior to the threshold and the aircraft bounced. Full power
was applied but the aircraft then touched down heavily 100
metres in from the threshold. The noseleg broke at the fork,
the propeller struck the ground several times, and the aircraft came to rest at the edge of the strip.
The strip did not meet the published requirements for an
ALA suitable for Private category operations. The
premature touchdown short of the threshold may have
resulted from visual illusions associated with the strip slope.
The aircraft had stalled during t he attempted recovery from
the bounce after initial touchdown.
Piper PA28-151, VH-IBU, Bankstown N.S.W., 12 Sep. 86,
Student, 14 hrs.
The student was undertaking his fourth solo flight and had
been instructed to practise circuits with touch-and-go landings. After acknowledging a landing clearance, the pilot
inadvertently dropped the microphone. He learnt down to
retrieve it and shortly afterwards the aircraft touched down
heavily about 200 metres short of the threshold. The aircraft
bounced, the pilot applied forward elevator control, and a
further heavy touchdown took place on the nosewheel and
propeller. The nosegear folded back and the aircraft
groundlooped to a halt on the flight strip.
The student had become distracted from controlling the aircraft while attempting to retrieve the microphone. When he
looked up again, he realised that the aircraft had deviated
from the desired flight path, but he had persevered with the
approach.
Piper PA31, VH-UCK, Benalla Vic., 16 Jui. 86, CPUCI. l, 895
hrs.
At the time of the attempted takeoff, the night was dark
with overcast cloud conditions and light rain falling. Wind
conditions were light and variable. The pilot reported that
initial acceleration was normal and the aircraft became airborne at about 95 knots. A positive rate of climb was
established and the landing gear was selected up. The pilot
subsequently advised that the speed then decayed to 90
knots. At this time there was nothing unusual in the engine
noise and the controls felt normal. Shortly afterwards the
propellers struck the ground 116 metres beyond the end of
the runway. The aircraft then struck an embankment and
passed through a fence before coming to rest 247 metres
from the initial ground strike.
Although wind conditions were light and variable when the
engines were started, shortly after the accident the wind was
moderate from the west/south-west. A detailed analysis conducted by the Bureau of Meteorology indicated that while
the pilot was preparing for takeoff, a cold front with winds in
excess of 20 knots had probably passed over the aerodrome.
As the pilot had conducted the takeoff on runway 08, there
was probably a substantial tailwind component. Conditions
were also assessed as suitable for the development of
microbursts but the lack of recording instruments in the area
prevented confirmation that this type of phenomenon had in
fact occurred.
The pilot had been deprived of the opportunity to observe
changing wind conditions at the aerodrome. The wind direction indicator adjacent to the threshold of runway 08 was
not lit and the illuminated wind direction indicator was not
visibile from the point where the aircraft was lined up for
takeoff.
Cessna 15().M, VH-WWS, Coldstream Vic., 10 Aug. 86,
Student, 39 hrs.
The pilot had been conducting a series of circuits with touchand-go landings. Shortly after takeoff for another circuit, the
engine lost power. The pilot pumped the throttle and the
engine responded briefly but then failed again. The pilot was
committed to a forced landing in an unsuitable area. The
touchdown was heavy, the nosegear was dislodged, and the
aircraft overturned.
The reason for the loss of engine power was not established.
Corrigendum
In the 'Final updates' section of Aviation Safety Digest 131,
an incorrect registration was given in the preliminary information for a Beech C23 accident at Echuca on 05 Jan. 86.
The correct registration was VH-MRG, not VH-MRC as
sta ted.
Aviation Safety Digest 132 I ix
�r
I
The Digest is pleased to announce its second
photographic competition for aviation enthusiasts.
Aviation Regulatory Proposals
Category 2 -A Nikon
FG-20 Auto/ Manual
Camera with a 50mm
fl.8 lens.
Retail Value: AS725.00.
The FG-20 is a 35 mm
single-lens reflex with
aperture priority
exposure and manual
over-ride.
Each edition of the Digest contains a listing of those ARPs circulated since the previous edition.
Should you wish further information about any of the ARPs, please contact your industry
organisation.
Status
Helicopter Winching
85/16
(Issue 2) ANO 29.7
Issued 02 December 1986
Comments due 28 February 1987
Category l -A Nikon
F-30 l Program/ MotorDrive Camera with a
50 mm fl.8 lens.
Retail Value:
AS 1,035.00. This is a
state-of-the-art
automatic camera
with manual reversion
and integral film-wind.
The competition is designed to encourage an
awareness of satety related matters in the field of
civil aviation. It is also to promote a high standard
of photography of aviation subjects which may be
used to maintain the quality of presentation and
reader participation in the Aviation Satety Digest.
The competition is sponsored. by Maxwell Optical
Industries Pty Ltd, the Australian distributors of
Nikon photographic equipment.
Aviation Regulatory Proposals (ARPs) are an important means by which the Department consults
with industry about proposed changes to operational legislation and requirements. C6pies of all
proposals are circulated to relevant organisations, and occasionally to individuals for information and
comment. The comment received provides a valuable source of advice which greatly assists the
Department in the development of the completed documentation.
Number Subject
Three prizes will be awarded as follows:
Three categories will be judged:
Category l - For the best print or transparency
on the general subject of Australian civil aviation
or Australian civil aircraft. The judges' emphasis
in this field will be photo graphic and artistic quality.
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safety aspect or an unsafe aspect of Australian
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contributory factor in aviation accidents is the
'human factor'. The judges' emphasis will be the
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photographs in particular are a valuable
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Category 3 - A Nikon
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flash.
Retail Value: AS595.
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Entries close with the last mail on Friday,
26 June 1987 and should be addressed to:
Photographic Competition
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GPOBox367
CANBERRA ACT 260 l
CONDITIONS OF ENTRY:
Any nu mber of entr ies may b e submitted fn any or all categories.
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of the Digest or available !rom the SaJety Promotion Liaison Of!icer m any
Dep a r tmental Regional Olfice. Pilot Br iefi ng Room a nd most Photographic stores.
Entries should be clearly m arked - PHOTOGRAPHIC MATERIAL - DO NOT BEND.
x I Aviation Safety Digest 132
The competition is open to all Australlan citizens with the exception of staff from
the Solely Promotion Section of the Department of Aviation and employees of
Maxwell Optical Industries. a nd their immediate families.
The Digest reserves the right lo p ublish once. a ny entry received in this competition.
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�ENTRY FOR.M FOR THE
.
· .
DIGEST PHOTOGRAPHIC COMPETITION
TO: Photographic Competition
Aviation Safety Digest
Department of Aviation
GPOBox367
Canberra, ACT 2601
_
.
Pilots rights
ENTRIES CLOSE: Last Mail,
Friday,
19June 1987
As PILOT-IN-COMMAND of an aircraft you
HAVE NO RIGHT
... to endanger the lives of your passengers by:
• loading the aircraft beyond its weight and
balance limits
• omitting any flight planning or preflight steps
• carrying insufficient fuel
• not completing all systems checks and vital
actions
• flying beyond the limitations of your licence,
rating or currency
• accepting an aircraft that is less than fully serviceable
• exceeding your duty time linlits
• flying when you are not completely serviceable
.. . even if your passenger asks y ou to.
Results will be published in the
Spring edition of the Digest
Dear Sir,
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details are as follows:
Category of Entry: . . . . . .. .. .. .. . . . .. . . . .. ..... ...... .... ... Film Size and Type: . .. .. .. . . .. .. .. .. .. .. .. .
Camera Type: .. . . . . .. . . .. . . . . . .. . . .. .. .. . .. .. .. .. .. .. . . . .. .. Caption or Title:
.
...
Description of the Photograph and Theme: .
Name of Entrant: ..... ........ ..... .
Address: .... ........ ............................. ............. ..... ... .. .
I do/do not wish the photograph to be returned (return postage enclosed?)
I agree to be bound by the conditions of entry as described in the advertisement
(Date)
(Signature)
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--- -------------------------
~
--------------~-
ENTRY F.ORM FOR THE
DIGEST PHOTOGR~PHIC COMPETITION
TO: Photographic Competition
Aviation Safety Digest
Department of Aviation
GPOBox367
Canberra, ACT 2601
.
ENTRIES CLOSE: Last Mail,
Friday,
19June1987
As PILOT-IN-COMMAND of an aircraft you
HAVE EVERY RIGHT to expect your
p assengers to:
• comply wit h your directions as to loading of
t he aircraft
• respect your request for silence during takeoff
and the approach to land
• accept without complaint the nature of VFR
flight and the possibility of delays or overnight stops en route
• follow your inst ructions in the event of an
emergency D
Results will be published in the
Spring edition of the Digest
Dear Sir,
Enclosed is an entry for the Aviation Safety Digest Photographic Competition. Details are as follows:
Category of Entry: . . . ......... .............................. .... Film Size and Type: . . . . ... . . . ............. ..
Camera Type: ... . .. ... ... ..... ............ ........................ Caption or Title:
. .. ............................ _
---~
Description of the Photograph and Theme: . . .. . . . . . . .. . . . .. .
Name of Entrant: . . . . . . . . . . . . . . . . . . . . . .. . .. .. . . .. .. . . . . . .. . . . . . . . . . . . . .
Address: . . . .. . . . . . ... . .. .. .. .. .. . . .. .. .. . . . .. . .. . .. .. .. . . .. .. .. .. . .. .. . . .. .. .. .. . . .
I do/do not wish the photograph to be returned (return postage enclosed?)
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(Signature)
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(Date)
�Aviation Safety Digest
Aviation Safety Digest
132
Wiggly amps
132
effect. Some twin engine aircraft, despite their
having two generating systems, are in the same
position. Typically, electrical generating system
failures result from such mundane causes as a
broken V belt, loose or broken wire to the
generator/alternator or voltage regulator, voltage
regulator failure and even bearing failures in
alternators/generators.
Note that while one failure may cause a loss of
generated electrical power, that does not imply a
total loss of electrical power. All being well, there
remains a battery with a capacity to supply some
power for some period of time. Despite this
redundancy, the Department receives, on
average, 50 reports of loss of electrical power in
single-engined aircraft each year.
Aircraft electrical systems
Frank Grimshaw is an electrical engineer in the
Airworthiness Branch of the Department of Aviation.
A
IRCRAFT electrical systems work well and
last a long time. Of course they do, but like
- all things, sooner or later there is bound to
be a system failure. Whether or not the failure
turns out to be a problem depends on many
. things: the nature of the failure, the type of
operation in which the aircraft is involved, the
pilot, or more specifically, the pilot's knowledge
of the electrical system, and last but not least,
the adequacy or otherwise of aircraft
maintenance.
The purpose of this article is not to provide
specific guidance on what pilots should do to
minimise the effects of an electrical system
failure - everyone knows the immediate requirement is to reduce electrical system loading. Nor
is this article going to attempt to tell aircraft
maintenance engineers how to perform
maintenance - they have all been thoroughly
trained and maintenance manuals contain the
necessary detailed information. Perhaps that
doesn't leave much scope for an Aviation Safety
Digest article. But let's have a closer look at
each of the factors mentioned in the opening
paragraph and see if we really appreciate their
significance.
·
(At this point I should add that the following
comments are really directed at single engine aircraft. Some of the comments may be equally
applicable to light twins and larger, but each
reader should make due allowance for the
differences.)
Electrical System Failures
Naturally there are many components in any aircraft electrical system whose failure could result
in loss of generated power. In single engine aircraft the failure of only one item can have that
The designer has rules which require that the
likelihood of total electrical failures shall be
remote. The rules are applicable at the time of
certification of the aircraft, one of the certification tasks being to review the aircraft electrical
system to ensure that the loss of all electrical
power is unlikely. In addition, the rules apply to
aircraft modifications, again to ensure that
nothing is done to the aircraft electrical system
which would reduce the level of safety originally
established. These rules apply to the aircraft
hardware, and where necessary , to the methods
of operating the electrical system by instructions
and procedures contained in the aircraft's flight
manual.
Type of aircraft operation
There would be little argument that loss of electrical power at night, in IMC, is the most critical
situation. However, before addressing that situation in more detail, let's not neglect apparently
less dramatic situations. Perhaps the least severe
operation as far as the consequence of loss of
electrical power is concerned would be day VFR.
Provided the aircraft had no critical systems
requiring electrical power, and at this time in
Australia none do, there is no reason why the aircraft could not at least be safely landed albeit
perhaps not where originally intended. Before
writing-off this situation as 'not a problem', give
some thought to your typical operations or those
of your students. What systems would y ou have
left - flaps, undercarriage extension, comms?
What compensating actions would be required
and how would you ensure you were not going to
be a hazard to someone else? Perhaps while
addressing those questions it would be wise to
consider how much monitoring of your aircraft
electrical system y ou per form when flying in
these relatively ideal conditions.
How about night VMC? In this type of operation
there is likely to be significantly more reliance on
the aircraft electrical system - for instrument
lighting, if nothing else. Again though, t he rules
applicable to t his type of operation require the
carriage of a torch, so even if all electrical power
is lost there is no good reason why a safe landing
should not be possible. Don't dismiss this situation too lightly though. Ever tried landing at
night with only a torch (stuck in you r mouth or
right hand or wherever) for instrument lighting?
No landing lights either, perhaps no flaps and
possibly with the undercarriage having to be
extended manually (was it 50 turns of the
handle?), but hopefully landing at your intended
destination and hopefully with runway lights (if
you can turn them on)!
Now to IFR operation - loss of electrical power
leaves you with a torch for illumination and a
standby compass for navigation. Good luck! Yes,
but I always have the aircraft battery as an
emergency back-up, you say. True. But for how
long following a generating system failure? And
while I am at it, how are you going to know
when the generating system fails? How long is it
going to take you to reduce t he electrical loads
on the battery to a minimum? How do you
reduce the electrical loads to a minimum without
switching off the system(s) you need? Just what
are the minimum loads you should retain? What
compensating actions are necessary when load s
are reduced to your minimum - is the undercarriage driven by an electrically-operated hydraulic
pump? Will you have flaps? Is the electrical fuel
pump really necessary?
Obviously t he answers to all these questions
spring to mind while t he autopilot is controlling
the aircraft for you. Another load on the battery!
Of course if t he answers don't spring to mind
there is always the flight ma nual which you have
to carry in the aircraft. That must have the
answers. Checked it lately? OK, the pilot's
operating handbook - maybe, but do you have
it, and have you got t ime to read eit her of them
anyway?
Like most things in life, the answers to these
questions are neither simple nor easy. It all
depends. But, one thing is sure, you do not have
any time to spare after the generating system
fails if y ou are going to successfully manage the
situation.
Aircraft system knowledge
It should be obvious by now that a detailed
knowledge of the aircraft electrical system is an
essential requirement for all who fly IFR. This is
not to suggest that a detailed knowledge of all
aircraft systems is not necessary for all operations. However, in IFR the electrical system does
assume considerable importance.
Knowing t hat non-essential electrical loads
should be shed as soon as possible after a
generating system failure is not sufficient
knowledge. Knowing how and what loads to shed
is essential - and perhaps in what order. Having
some idea of the likely time available before battery power is depleted is desirable since it provides the key to the urgency of your actions. Of
course it makes sense that whatever battery
power is left after a generating system failure
should be conserved for essential systems.
But there is a peculiarity in battery characteristics tha t makes the time element critical. The
peculiarity being that the amount of energy that
can be extracted from a battery is dependent on
the rate at which the energy is extracted. The
higher the ra te the lower the total energy that
can be extracted. For example, a 15 Ampere
Hour battery may be able to supply a current of
t hree amps for five hours. However, the same
battery will only provide about eight amp hours
at 15 amps discharge rate (32 minutes), six amp
hours at 30 amps (12 minutes) and 5.25 amp
hours at 40 amp s (eight minutes).
To illustrate the point mentioned above, and
perhaps some others, it is useful to consider a
scenario for the operation of an aircraft. Let's
take a common single-engine I FR approved t ype
and make some assumptions (if you don 't think
they are reasonable check out your aircraft), and
let's look at t he state of t he battery (related to
emergency time available) at various times. Let's
assume:
1. The aircraft has a generating system failure
warning light that gives immediate warning of
a failure.
2. A generating system failure occurs soon after
takeoff a t night, in IMC.
3. It takes you two minutes to shed all nonessential loa ds.
4. The aircraft has a serviceable 15.5 amp hour
lead acid battery which is fully charged before
engine start.
5. You spend five minutes on t he ground after
starting for taxiing and run up, pretakeoff
checks etc.
6. The aircraft has an emergency load of 11 amps
and a normal load (at night) of 40 amps
excluding landing lights.
We start off with a serviceable battery, t hat is,
one having at least 80 per cent of original capacity a nd which is fully charged. Battery capacity
is 12.4 amp hours. Assume two 10-second
attempts at engine start. Because of the high
current drain, t he battery capacity will typically
be reduced by 3.3 amp hours. We now have
9.1 amp hours remaining.
After engine start we apply the normal load of 40
amps by switching on such things as radios, nav
lights, taxi light and la nding light, anticollision
beacon etc. The alternator now provides some
power; however, we are at idle rpm and even
alternators don't provide full output at idle. Let's
assume the alternator provides 50 per cent of its
output at 1000 rpm (a not unusual case) and is a
50 amp alternator. The alternator therefore provides 25 amps and t he battery must supply the
remainder of t he 40 amp load, i.e. 15 amps, for
the five-minute taxi etc. At this rate of
discharge, t he battery will typically lose a further
2.25 amp hours capacity. Remaining battery
capacity is 9.1 - 2.25 = 6.85 amp hou rs.
-1
�Aviation SafetyDigest
Aviation Safety Digest
132
132°"
Very soon after takeoff the generating system
fails. We know immediately because of the
failure-warning light. We now have a 40 amp
load for two minutes while we collect our
thoughts, control the aircraft in IMC and reduce
the load to the emergency figure of 11 amps.
During this two minutes we will have consumed
around 3.4 amp hours of the battery's capacity.
We now have 6.85 - 3.4 = 3.45 amp hours left.
With the emergency load of 11 amps, the battery
will typically only provide 0.7 of its capacity. We
therefore have:
0.7 X 3.45 amp hours remaining= 2.15 amp
hours
2.15 X 60 = 129 amp minutes
129 amp minutes = 11.7 minutes of battery
power at 11 amps
That's right - about 12 minutes!
Remember the assumptions. A fully charged serviceable battery, a warning light that alerted us
immediately to the generating system failure and
last, but not least, sufficient knowledge of the
systems in the aircraft to be able to shed nonessential loads in only two minutes. What would
have happened if we had taken just a couple of
minutes longer to react and shed the nonessential loads? Well, with the 40 amp load we
would have had only a total of about four or five
minutes of battery power and by the time we had
shed the loads, would have had little or no
. electrical power left!
Aircraft maintenance
So much for knowledge of the electrical system.
What about the maintenance factor that was
mentioned earlier? Let's look at a significant
assumption in the foregoing example - a serviceable, fully-charged battery. Is it? Does it ever get
a capacity check? When is it replaced? How
many times have you had to do a jump start
with an external power source? How many times
has the engine on your aircraft been obstinate at
starting and how much power would have been
left in the battery after it finally started? Finally,
how many times have you written-up the
maintenance release for problems you may have
had with an obviously less-than-serviceable battery? Maintenance staff are not going to fix a
problem they are not aware of.
Summary
Obviously this article has asked a lot of questions. Not too many answers have been provided
though. Why? Well, that wasn't the purpose of
this article. Perhaps it is sufficient to pose the
questions and leave the answers for another time
- it's probably more value for each of us to consider these situations in our particular aircraft
and to refer to our own flight manual. In the
meantime, if we all give a little more thought to
the humble old electrical system, the article will
have achieved its aim 0
PS: Winter is approaching and batteries don't
like cold weather.
Parting
gestures
HE FIRST effect of any significant
imbalance in a rapidly rotating mass is vibra- tion. The severity of such vibration, when
a propeller loses part of its blade, is surprising in
its violence.
The following examples illustrate the' dramatic
consequences.
The Cessna 206 had taken off from Longreach
and the pilot reduced power to 25 inches and
2550 rpm at about 300 feet agl. At 500 feet, the
pilot turned left to intercept the 222 ° omni
radial.
At 1200 feet abeam the field he gave the departure report and continued the climb. By 3500 feet
the throttle was fully forward to maintain 25
inches MAP. About 30 seconds later there was a
loud bang and violent vibration.
'Immediate action was throttle closed - no
change (suspected broken prop). Mixture to "idlecut-off" - no change. Mags off - no change.
Climbed rapidly to reduce speed. Engine
[propeller] stopped at 75 knots. Turned back
towards Longreach - glide established - doubtful whether we could reach the field - selected
two other sites. Fuel off - MAYDAY calls - 3
VHF, 1 HF - no replies. One more on VHF was
replied to. Decided safest alternative was to land
on bitumen road south of the airfield. Commenced approach. Two cars on road in the way
but managed to manoeuvre to land behind them.
Landed successfully.'
Damage was:
• 1 prop blade broken off about 6 inches from
the hub
• 2 rear engine mounts broken
• structural damage around left mount
• front cowling broken
• left cowling buckled
• chafing to baffles and plumbing.
In the next case the pilot was flying a home-built
aircraft. He was cruising home towards Camden
after a general flying sortie, flying level about
130 knots and at about 1300 feet agl.
Suddenly the aircraft shook so violently that the
pilot was flung against the side of the cockpit.
The aircraft started vibrating severely. He closed
the throttle, shut off the fuel and ignition and
slowed to 80 knots. The vibration was still
violent .
The area below consisted of small paddocks with
large gum trees and power lines. He made an
approach between two trees to land in a
reasonably sized paddock, although he knew it
wasn't long enough. The aircraft continued
vibrating severely.
In the latter stages of the approach towards the
paddock the right wing struck a tree. The aircraft dived into the ground and was destroyed.
The pilot was seriously injured.
More than half of one of the propeller blades had
separated in flight. The subsequent vibration was
so severe that the pilot's vision was affected and
he could not accurately judge his approach
between the trees.
In such circumstances it is obviously insufficient
merely to close the throttle. Even shutting down
the engine by selecting the mixture control to the
cut-off position may not stop it. The rotating
mass has t o stop rotating for the vibration t o
cease. This means that the pilot has to reduce
the airspeed to a minimum until the propeller
stops - and these actions have to be done
quickly to prevent further damage. It is possible
for the vibration to be so violent that it will
cause the engine to be shaken out of its mounts.
Then there is the forced landing. Our pilots coped
exceptionally well with the problem.
Like most things, prevention is better than cure
- watch out for nicks, although in some cases
the fatigue damage may not be evident during a
walk-around. If in doubt have a LAME check it
out.
To be safe:
• have any sharp nicks contoured out - particularly those in the leading edge area of the
outer half of the blade
• Check the rear face of the blade as well as the
front face
• Avoid run-ups over loose stones
• If you have to man-handle the aircraft without
a tow bar, pull or push only the part of the
blade immediately next to the hub - where
there is plenty of 'meat'.
If you experience any severe vibration in flight,
immediately:
• close the throttle and try to identify the
source of the vibration
• if the vibration continues, reduce airspeed and
again try to locate the source - it may be an
unlocked door or hatch
• if the vibration continues, shut down the
engine.
I haven't experienced a propeller failure of this
nature, but from the description given by these
pilots, there seemed little doubt as to the source
of the vibration 0
�Aviation SafetyDigest
AviationSafety Digest
132
132
---
,: =
= -== = =
«
(Everything you always wanted to know about
flying but were afraid to ask, or everything you
always knew about flying but were reluctant to
tell.)
AIRFLOW is a column through which you are
encouraged to communicate with the aviation
community on topics which are related to flight
safety.
Your ideas, thoughts, questions and suggestions
are welcome in this forum, irrespective of your
experience level or your status within the aviation community. Queries from student pilots and
advice from instructors will be particularly
welcome.
Anonymity will be respected if requested.
'Immunity' applies with respect to any selfconfessed infringements that are highlighted for
the benefit of others.
sf
=
=
It wasn't too bad, I suppose. It didn't cause any
damage, but it was a bit disconcerting to a 70
hour pilot. These days, no matter who is in the
right-hand seat, I do my own preflight. Little
things, if unexpected, can kill too.
ANDREW J. KERANS
DARWIN, N.T.
As you point out, Andrew, it's the little things
that catch us out. It's strange when you think
about it, but if you rely on someone else to check
these things for you - you are trusting them
with your life. There aren't many people, perhaps
two or three, that I trust that much, and then
only because I have known them for a long time
and they have earned that trust. That might be a
good philosophy for aviation too.
Dear Sir,
I believe your editorial in ASD130 highlighted
two very important attitudes in the aviation
community:
Dear Sir,
This little incident could well be titled 'Make
Sure'.
. In October of 1982, as a new UPPL with only 70
hours or so in the book, I took a Cessna 206 from
Archerfield to Bathurst for the Hardie-Ferodo
races.
The trip down was uneventful and a great
weekend was had by all.
Come Monday and time to go home - the
weather had deteriorated below VMC - back to
town for lunch - the weather then lifted
somewhat, marginal VMC - back to the airport!
The aircraft was fuelled and preflighted and I
asked a passenger who was a student pilot to put
two litres of oil in the engine while I joined the
queue to phone-in a plan.
On my return, the passenger assured me that the
oil was now OK so we all strapped in, completed
the run up and took off for Archerfield.
At about 500 feet and a mile or so out, I sud·
denly discovered that clouds are not the only
way to go 'inadvertent VMC'. A thick coating of
black oil covered the windscreen.
I immediately made a slightly unusual radio call
to 'All Stations Bathurst' and rejofaed the circuit. The landing was safe but bumpy. It's hard
to judge a flare from the side window. A few
minutes were spent cleaning up the mess, topping off the oil, and making bloody sure the cap
was on properly this time. By the time we
arrived at Archerfield, the windscreen once again
had a liberal coating of oil blown from the nooks
and crannies under the cowl and, together with
the afternoon sun, made for another interesting
landing.
• first - all sections of the aviation community
are indeed interested in initiatives to improve
aviation safety
• second - there is some sensitivity to the
'human factor' aspects of seeking assistance
from ATC.
Pilots are reluctant to ask for help or declare a
problem in case they risk some form of subse·
quent disciplinary action. May I suggest a
change in the system which I believe would
humanise this delicate situation.
In general, a pilot is not informed when ATC or
Flight Service submits a routine incident report,
however minor the occurrence. This causes two
major problems:
• the incident report that is submitted may not
be completely accurate, or at best may not
include a picture of the events from both
points of view
• the pilot, not knowing a report has been sub·
mitted, may have dismissed the occurrence
from his or her mind in the belief that the
matter was over and done with.
There is obvious concern when some time later,
the pilot is asked to explain - not by A TC or FS
but by a BASI officer who is investigating the
occurrence and who is not personally aware of
the circumstances. There is a feeling of confusion
and resentment at being placed in a position of
having to defend oneself without all the facts and
having to rely on a vague memory of what had
happened. Hence the claim, 'They are ganging,up
on me! '.
.::.
=
--=
Surely it's common courtesy to inform all the
parties involved by phone or by mail:
• that a report has been submitted, and
• details contained in the report.
The pilot involved may then submit his or her
own report while the events are still fresh to
mind.
Yours faithfully,
MARY O'BRIEN
SCPL
Mary, I think your idea is both fair and worthwhile. I have asked BAS! to formally examine
your proposal and I will publish the details in
this column as soon as I have a response.
Thanks.
Dear Sir,
Southern Cross Air Race '86
Out of the blue, I received a phone call from my
mate's boss, Gary Armstrong, asking if I would
like to be a member of his crew in the Southern
Cross Air Race. Having gained my restricted
PPL in April '86, I jumped at the chance.
He explained to me some of his experiences in
previous races, both good and bad, the
camaraderie among competitors and, of course,
the 'dinner and drinks'.
Having heard of these events, my wife became
rather apprehensive about having me flying
around the skies of Vic., N.S.W. and S.A. for
four days, but nothing was going to stop me.
Friday October 17
We met at Moorabbin - myself, the pilot and
two other crew members. Our flight plan was to
track over Eildon then direct to Albury to pick
up one more crew member. After a successful
VMC departure from Moorabbin we headed for
Healesville.
Noticing the cloud cover above the Ranges, we
circled Healesville while Gary obtained a
clearance to climb to 5000 feet. After obtaining
his clearance, he was still apprehensive about the
cloud.
The point I am trying to bring to your attention
is that Gary had previously informed me that we
would be flying over Eildon and of the terrific
views and photographic possibilities.
Instilled in my mind was this route over Eildon
and I personally would have carried on being all
geared-up for this (and a terrific weekend to
follow) not thinking of safety or even an alternative route. Having little or no experience in
navigation or flying in such conditions, I was
fortunate to have Gary explain to me how easily
pilots are ' misled' and find themselves in serious
trouble.
=
«.:
Electing not to track over Eildon we amended
our flight plan and tracked Kilmore - Mangalore
- Albury, picked up our crew member and finally on t o Bathurst without mishap.
The race began Saturday morning from
Bat hurst, with the weather looking poor.
About halfway along t he first leg, we had to put
down for two hours at Temora due to bad
weather. We eventually got away and managed
to complete that day 's race route in poor conditions and by gaining weat her reports constantly
from the leading competitors.
I found the attention directed to the safety of
crew and aircraft by our pilot and all other competitors, was second to none.
After completing day one of the competition,
ourselves and two other crew elected not to complete the air race and we opted for Sunday in
Swan Hill.
WARNING: Seafood eaten in Echuca plays
havoc with the digestive system (or was it
something we drank?). Steve drank a bottle of
Mylanta (thickener) from Echuca to Swan Hill!
After a pleasant day in Swan Hill we set off for
Albury, with the weather to the south looking
poor. On touchdown at Albury, the thought of
staying overnight was already dawning on us.
After reading the met forecast and making
numerous calls to Melbourne, our pilot elected to
stay overnight in Albury. This was not an easy
decision to make as three of the crew had rather
important appointments in Melbourne on
Monday.
From discussions I overheard, there was a
chance that we could have got t hrough to
Melbourne but it would have been very touch·
and-go. Thirty minut es after this decision was
made, the storm activity around Albury, Kilmore
and Melbourne had increased significantly and I
felt great to be in Albury.
As Gary said numerous times during the
weekend - 'It is better to be on the ground
wishing you were in the air than in the air
wishing you were on the ground. '
All in all it was a terrific weekend. The comradeship of all the competitors, attitude towards
safety and the hospitality at the Aero Clubs was
great.
Next step, ' unrestricted'.
KIM BRITTER
VICTORIA
Thanks for the comment, K im. I too found the
pilots in the race to be most professional. I would
like to see Gary's philosophy emblazoned across
the sk y in large letters - IT IS BETTER TO
BE ON THE GROUND WISHING YOU
WERE IN THE AIR THAN IN THE AIR
WISHING YOU WERE ON THE GROUND wise words indeed.
�I wouldn't be
seen dead
without my
bone-dome
- - -- -
-- ------- -
-.-
-
- - -: - - ·-
Protective helmets for Agricultural pilots
Digest
.Photographic
Competition
Above - Example of a potential entry
for the general category - Category 1.
Right - Examples of potential entries
for the 'unsafety' category - Category 2.
If you see such potential hazards please report
them before they lead to damage to a valuable
aircraft or pilot - and of course take a picture
for the competition:
Unsafe -
one
These drums of discarded oil are awaiting collection for
recycling. Behind that wall is a hangar full of valuable
aeroplanes and valuable maintenance staff.
Unsafe - two
A not so obvious potential accident is this Cessna. It was
tied down but because there was no tie-down at the tail,
it has moved in the wind. Where aircraft are parked
close together this movement may be sufficient to allow
a collision. Also the now slackened tie..<:Jown on the far
side will allow that wing to lift should the wind change.
On this occasion the wind had dropped and there was
no significant risk of further movement but it does
illustrate the importance of that third tie..<:Jown.
I
READ FREQUENTLY of lives of Ag pilots
saved by the fact that they were wearing a pro• tective helmet. This of course implies a
properly designed and fitted helmet - but more
of that in a minute.
Remember the Pawnee Brave that crashed near
Griffith, N.S.W. late last year?
The pilot was carrying out the first spray run in
the particular paddock. Towards the end of the
run he was distracted when a large flock of birds
fiew up in front of the aicraft. The pilot descended to fiy under the flock and momentarily forgot
about a power line that was in the vicinity. As he
pulled up at the end of the run, the main undercarriage leg snagged the wire. The wire cutters
fitted to the gear did not sever the wire and the
aircraft impacted the ground some 82 metres
later.
The inertia reel which was selected to the auto
position failed to lock, and during the crash the
pilot was thrown forward. (The reel should loc,k
the harness on sensing the deceleration.) The
pilot's head impacted the padded instrument
coaming, and despite this padding he would have
probably suffered serious injuries if he hadn't
been wearing a helmet.
The pilot in this accident, Gavin Thomson,
kindly agreed to recount his view of the events.
'When I started my Ag flying training in 1979,
the company I worked for supplied me with a
new Gentex DH118 safety helmet. The training
pilot with our company insisted that it be worn
at all times while working. Although it was a
good quality helmet, I initially found it too
heavy, hot and generally irritating. However,
after persevering for a few months, I became
used to it and even felt uncomfortable without it
on.
�Aviation Safety Digest
AviationSafety Digest
_ _ 132
'Six and a half years later I was still using the
same helmet when I caught the two wires around
the undercarriage of the Pawnee Brave. The
wires did not break until the aircraft struck the
ground in a nose-down attitude. The front of the
helmet was undamaged even though the crashpad, dash and instruments were badly damaged
by it. At some stage of the accident sequence the
port wing folded back and a broken spray boom
passed through the side window, badly cracking
my helmet above the left ear. I am sure that
wearing a good quality helmet saved my life
twice in the one accident.'
Gavin goes on to say - 'Any pilot buying a
helmet should consider spending a few extra
dollars on an adjustable strap, suspended type,
which gives much better comfort and cooling and
probably gives better impact protection.
'One of the problems for a young pilot who has
just spent a lot of money on a Commercial and
an Ag rating is the very high cost of purchasing
a good helmet. I think Australian companies
should consider supplying helmets - as New
Zealand companies do.
'I would also like to add that some of the very
experienced Ag pilots, who often only work with
lap belts and ear muffs, should consider the
'e xample they are setting for new and inexperienced pilots, even if they have little regard
for their own safety.'
There is much in what Gavin has said. First, I
would like to shake the hand of the Ag instructor
who insisted his trainees wear a helmet.
Obviously, the wearing of a helmet will increase
the chance of surviving a crash - and in Ag
operations the crash is often as a result of a wire
strike and the aircraft is not under control.
Let's look though at the design of the helmet.
Pilots are reluctant to wear a helmet that is
heavy, hot and especially if it restricts the fieldof-view. It is the age-old problem of weighing up
the disadvantages against the odds of an accident where the helmet may save your life. It's
the same with a parachute. Many pilots initially
refused to wear one because of the discomfort
and the probability of successfully force-landing
the aircraft. As speeds got higher and the chance
of walking away from a landing became less, the
parachute was accepted. Similarly, the fighter
pilot should wear an immersion suit if he has to
eject, and if he is to survive long enough in our
winter seas to be rescued. However, the suit is
hot, uncomfortable and restricts movement.
Obviously it is a compromise. The odds of an Ag
pilot needing a helmet are high enough in my
estimation to warrant wearing one all the time.
What we must do is ensure that the helmet is the
lightest, most comfortable and least restrictive
that current t echnology can produce and pilots or
.o perators can afford.
132
The Gentex that was mentioned is a civilian version of the U.S. military SPH-4 helmet. It has
been in service for many years and is proven. If
you have one, I urge you to wear it. The point
that Gavin makes about the suspension is significant as is the damage caused by the sideways
impact of the spray boom. The Australian Forces
have reviewed the SPH-4 and are now acquiring
another helmet, the ALPHA, for both the Air
Force and Army pilots who fly low and slow. It
does have the adjustable suspension and is the
lightest available.
If you are about to buy a helmet it would be
worth trying both before you decide.
Of great importance in either case is correct
fitment.
If you still have doubts about the need for a
helmet, consider the following:
The pilot was ·making a night spraying run over
a cotton crop. During the third run at about 50
feet agl, the engine suddenly lost all power. The
pilot attempted a landing in a flooded paddock.
Immediately after touchdown, the aircraft nosed
over and sank into the soft muddy surface. The
pilot was able to extricate himself from the partly flooded cockpit.
The pilot had selected the most suitable area
available in the circumstances. When the aircraft
overturned, the fi breglass roof of the cockpit
failed and cut into the top of the pilot's helmet.
Had the pilot not been wearing this protection, it
was likely that he would have suffered head
injuries and, as a result of t his incapacitation,
probably would have drowned D
---;-r--
Doped-up?
Heady advice on the use of prescription drugs by
anyone involved in aviation.
Doctor Harry Rance is a specialist m Aviation Medicine
in the Department's Central Office.
HE WORD 'drug' has many connotations. In
general terms we are concerned with those
_ chemical compounds which may be taken to
cure specific symptoms or t o stimulate except ional behaviour. For example a drug could be a
cure for hay fever, or an antidepressant. It could
be a sleeping pill or a counter to sleep. It could
be a relaxant or it could be a 'pep pill'. These are
all drugs and all have effects which can be
significant to our ability to act as pilot-incommand.
Let's examine a few more common drugs:
Anti-histamines - a very commonly prescribed
drug for allergies such as hay-fever and contained in many 'cold' cures. Anti-histamines can
cause drowsiness.
Amphetamines - sometimes prescribed with
diets as they reduce hunger. Amphet amines are
stimulants relieving feelings of tiredness and
depression and giving temporary feelings of
vitality and energy. In larger doses they can
cause elation, aggressiveness and excitability.
Antibiotics - drugs used to combat illness or
disease. The pilot being treated will probably not
be fit to fly because of the illness but some a nti·
biotics produce side-effects such as headaches,
upset stomach, slight depression or even act as a
sedative. Some people may be allergic to
penicillin, a common antibiotic.
T
Analgesics - 'headache' powders and tablets can
be taken.without immediate side-effects but some
of the stronger medications can cause possible
side-effects.
Barbiturates - sleep-producing drugs. Used as
sedatives or as sleeping pills, barbiturates can
upset thought processes and impair judgment
and co-ordination. They can induce sleep at
inappropriate times and although described as
'short acting' may leave a measurable effect for
some time.
Tranquillisers - are used to treat stress, anxiety
and emotional distress. All are likely to cause
drowsiness and slower reactions. Nearly all of
them intensify the effects of alcohol or sedative
drugs. They have been associated with some aircraft accidents.
Drugs to reduce blood-pressure - can also cause
side-effects such as headaches, drowsiness and
dizziness.
Other dangers associated wit h pill-popping and
flying include:
Allergies - An allergic reaction can occur
without warning and can be incapacitating.
Side-effects - Different people react in different
ways. Some pilots may be subject to nausea or
vertigo (disorientation) from drugs which are
innocuous t o most of us.
Change of effect - High-altitude or high 'g'
forces h ave been seen to modify the effect of
some medications.
Combinations - Drugs in combination can
cancel each other, aggravate each other or produce a completely new reaction. Similarly the
mixt ure of t he social drug, alcohol, with medication can produce unexpected results.
Flying is a demanding art and skill. It requires
our best ability and that comes with a sickness·
free and drug-free body. Any medication carries a
potential for reduced performance and the use of
drugs to extend performance in the short term
carries longer term penalties.
Social drugs are out. Non-prescribed drugs are
out. Borrowing a colleague's cure is out. Medication should be prescribed in the knowledge of t he
side-effects and its influence on your ability to
fly an aircraft. Off-the-shelf medication must be
in moderation and treated with caution.
The safest way to take drugs is to first identify
the cause of the problem and have it fixed before
you fly.
Don't be tempted to use drugs t o offset the
symptoms and then end up in the situation
where you have both the problem and the sideeffects of the cure while you are trying to fly an
aeroplane D
�
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1987
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--
~
- -- .. .
....
.
�Aviation Safety Digest is prepared by the
Department of Aviation and is published by
the Australian Government Publishing
Service. It is distributed to Australian licence
holders (except student pilots), registered
aircraft owners and certain other persons
and organisations having an operational
interest in safety within the Australian civil
aviation environment.
3
4
Editorial
A bunch of the boys was beating it up ...
Some pilots cannot resist the temptation to do beatups and impromptu displays.
Aviation Safety Digest is also available on
subscription from the Australian Government
Publishing Service. There is a subscription
form in this issue. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.G. T. 2601,
AUSTRALIA
Telephone (062) 95 4411 . Telex AA62013
Subscriptions may also be lodged at
Commonwealth Government Bookshops m
the capital cities.
6
Unless otherwise noted. articles in this
publication are based on Australian
accidents, incidents or statistics.
Reader contributions and correspondence
should be addressed to:
8
9
What a drag!
Some propellers have latches which prevent feathering below a certain RPM .
10
The seat of the problem
It's difficult to maintain control of the aircraft when
you're flat on your back.
13
Airflow
The readers column.
14
Pilot workload
the final straw?
In some situations the pilot's workload is critically
high. A small additional task may cause serious
distractions.
Aviation Safety Digest
Department of Aviation
P.O. Box 367,
Canberra City, AC. T. 2601, AUSTRALIA
Printed by Ambassador Press Ply Ltd
51 Good Street, Granville, N.S. W. 2142,
AUSTRALIA
Things that go thump in the night
A night approach into an ALA is a critical manoeuvre
requiring total concentration.
The Editor.
©Commonwealth of Australia 1986
ISSN 0045-1207
R851979(2) Cat. No. 86 0310 3
Strike one . . . you're out! (again)
Wire strikes are still a major hazard and often it's the
one you have seen that gets you.
Distributees who experience delivery
problems or who wish to notify a change of
address should contact:
The Publications Distribution Officer
Department of Aviation
P.O. Box 18390, Melbourne, Vic. 3001,
AUSTRALIA
Telephone (03) 662 2455
16
Circuits and bump
The decision to abort must be preplanned and not left
until it's too late.
19
Y'all come back now, y'hear?
Courteous pilots are welcome at glider fields.
The views expressed in the Aviation Safety
Digest are those of the editor or the
individual contributor and are intended to
stimulate discussion in the fields of aviation
safety and related areas. They do not
necessarily reflect the policy of the
Department. The articles are intended to
serve as a basis for discussion and even
argument in an effort to identify and resolve
problem areas and potentially hazarduous
situations.
Reader comments and contributions are
welcome but the editor reserves the right to
publish only those items which are assessed
as being constructive towards flight safety.
2 I Aviation Safety Digest 131
Editorial
Contents
20
Nut case
Another life is saved by a protective helmet.
21
22
Photographic competition
~
AY I TAKE this opportunity to present my credentials. I
was born in 1944 in England and grew up in Melbourne.
In 1960-61 I learnt to fly at Biggin-Hill, to glide at White
Waltham and to parachute at Fairoaks in the U.K. I continued
flying at the Royal Victorian Aero Club and parachuting at
Packenham. In 1964, I joined the RMF where I spent twentyone years as a fighter pilot, test pilot and project manager. I
served in South Vietnam as a Forward Air Controller, flying
Cessna 0-2A aircraft. I completed the course at the Empire Test
Pilots School in 1972 and flew many aircraft types ranging from
gliders and Chipmunks to the Argosy and Lightning. My last post
in the AMF was as Resident Project Manager for the Wamira.
More recently I was the Chief Ground Instructor and an active
flying instructor at the Australian Aviation College at Parafield.
This issue of the Digest is the first that is completely produced
'under new management' . It represents an attempt to make the
magazine more positive, more constructive and more readable.
Traditionally, the Aviation Safety Digest has been a forum for
the analysis and discussion of causes of accidents. Articles
were prepared so as to present the probable sequence of
events which led to a particular accident or series of accidents
and to forewarn the rest of us. We can and should all learn
from each other's mistakes. However, a problem remained in
cases where the cause was not posi tively identified or where
there was no one correct solu tion or course of action. To
enable discussion of such items I have taken responsibility for
presenting my opinion of what might have happened, or what
should happen . I do this in the knowledge that I could well be
wrong but at least we can all learn from the results and subsequent discussion.
I am also encouraging individual contributions from many
sources so as to bring ou t into the open , topics which have
been misunderstood, mistaught , misapplied or si mply avoided. It
is therefore essential that you the readers have your say. The
authors of such material will be clearly credited.
The World Gliding Championships at Benalla in Victoria have
highlighted that very active type of flyi ng and there are many
facets that are applicable to powered flight. The glider pilots'
sensitivity to slight changes in weather conditions, their need for
constant lookout, the continuous demand for assessment and
decision-making, the stress of competition and their selection
ar:id achievemen t of a suitable landing area, are skills that cou ld
be refined by all pilots.
Summer is upon us and with it the need for care of our own
well-being and physical condition. There was an excellent article
in Digest 122 on heat stress, which I encourage you to read
again. The human factor is no less significant this year and I will
continue to accentuate these topics.
The photographic competition is in full swing and your input will
be welcome. I wou ld personally like to encourage black-andyvhite photos as they provide a valuable contrast to colour and
can be widely used throughout the Digest. The competition is
fully described in the back of this issue.
I wish you all a safe and smooth 1987 D
A glaring deficiency ... or shades of
darkness
Selection of the correct sunglasses is important for
pilots.
DAVID ROBSON
Editor
[
Covers
Front. The pleasure of general aviation is
well expressed by this colourful little aircraft - Decathlon, VH-KAR - at
Parafield. As the sage once said: 'Flying is
like love - it can be shear pleasure if
you're careful, shear misery if you're not.'
Photograph by David Robson NIKON F - Fujicolor 100
Back. There is still a 'cowboy ' element in
aviation and like the original cowboy, his
days are numbered. If you know a cowboy
(or cowgirl) pl/ot, don't ;ust ignore it say something, or at least warn your
friends.
Poster design by Soussanith Nokham
\
EditOf'
Editorial assistant:
Graphic design.
David Robson
Karen Hutchison
Lesley Gordon
Tony Kelly
Photographs P 7
p 19
P22
Cartoon
P 12
Illustration
P8
John Freeman
Jack Stevens
John Devine
Soussanith Nokham
Ian Dickinson
Aviation Safety Digest 131 I 3
�l
I
A bunch of
DI boys was
beating it up
~'"Ti INCE
• • •
LILIENTHAL, pilots have regularly
+~ collided with solid objects and come off
~ second best. In the early days the pilots had
limited control of their aerial vehicles. Collisions
were largely unavoidable. However, alongside the
evolution of the aircraft, piloting skills were
being developed. With this developing skill and
confidence, pilots began to demonstrate their
degree of control and degree of daring by flying
as low as possible, climbing as high as possible,
diving as fast as possible and recovering as late
as possible. These arts were refined by the stunt
pilots of the 1920s and 1930s - highly experienced showmen with highly manoeuvrable aircraft in highly rehearsed scenarios.
The image lingers. The temptation for the 'redblooded' pilot to fly under the wires, between the
trees, to make waves with the prop-wash or to
leave skid-marks on the sand is almost irresistible. More pilots than would care to admit it
have succumbed to the temptation, frightened
themselves and returned to their home base
sheepishly, grateful to be alive and slightly more
reflective than when they took off. Some escaped
unscathed, some had dented pride because they
were foolish enough to display their inadequacies
in public view, some had dented aeroplanes and
some had dented heads. Many didn't make it
back at all.
Personality has a lot to do with it. Some people
are born 'hams'. The opportunity to perform in
front of a live audience is simply irresistible.
Some people cannot resist the opportunity to
compete. It is a natural characteristic of the
human animal to strive to do better than his or
her fellow. It's part of the will to survive. Unfortunately in the aviation game, many do not
survive.
Not all of the inadequacies are human. Most
modern light aircraft do not have the control
response, the structural strength nor the excess
thrust to allow display routines that are both
exciting and safe. The mark of the professional
display pilot is that he or she can show the limits
of the aircraft without breaking it. They take
their work seriously and some of them, despite
their thoroughness and care, also succumb.
Display flying is a high-risk occupation. There is
little margin for error.
Beat that -
one
What could have been more fun than a 'fly-in' t o
a country property - a chance to chat about aircraft and flying and a chance to show off a new
aircraft that had been lovingly built by hand
over a period of nearly seven years.
Several aircraft arrived overhead the property
together and while some circled the farmhouse,
the remainder went on to the airstrip and landed .
One of the aircraft, a beautiful red and white
Starlet, circled the house a couple of times then
conducted a low flypast. During the low run the
aircraft was estimated to be flying at 100 knots
and at an altitude of about 20 feet.
As it approached the house, the pilot raised his
right hand and threw something out. As he did
so, the right wing dropped slightly and hit the
top of a tree next to the house. Impact with the
tree occurred 5 metres above the ground and
severed the right wing at mid-span. The uncontrollable aircraft hit the ground with a 'thump'
and disintegrated.
The pilot had thrown a flour bomb. He had a
history of low flying which was considered
dangerous to the extent t hat his colleagues had
cautioned him several times. H is club had even
considered expulsion but thought they might be
able to better influence his behaviour if t hey kept
him within the group.
The pilot died on impact .
The Starlet is controlled by t he right hand on t he
control stick and the left hand on the t hrot tle. It
might be said that changing hands to throw t he
flour bomb (thereby having to fly at very low
altitude using the left, non-standard hand) caused
the wing to drop and therefore impact the t ree.
However, the pilot should simply not have been
there in the first place.
Many of us have flown at low altit ude and
perhaps below the legal and safe 500 feet or 200
feet agl that was authorised. But 20 feet, in close
proximity to a house and tree, while flying with
the left hand and throwing a flour bomb!
Beat that -
two
At t he conclusion of a t raining op eration, t he
pilot was a sked t o ferry a Bell 47G back t o an
airst rip on the property . A second pilot was on
board as an observer.
After takeoff, a practice autorotation was conducted over t he dam and wa s followed by some
unauthorised low flying in the vicinity .
On arrival at the strip, the helicopt er performed
several low runs with t orque t urns t o change
direction at each end of the strip. The second
torque turn was assessed by the CFI who was
watching from the ground, as being well outside
the limits of the aircraft and he did not expect
the pilot to recover from it . The CFI was going
t o a parked aircraft to use the radio to tell the
pilot to stop the illegal manoeuvres but , after t he
second torque turn, he t hought the pilot had
frightened himself enough t o stop any fur ther
antics voluntarily .
The helicopter then flew in a southerly direction ,
parallel to the airstrip. At t his stage, t he CFI
thought t he aircraft was returning to the p arking
area to land. However, near the southern end of
the strip, just p ast t he parking area, t he aircraft
entered a t hird t orque turn from low altitude.
During this manoeuvre, the helicopt er wa s pulled
up past t he vertical and reached an altitude of
80-100 feet. The nose t hen fell a way to t he left
and t he aircraft dived into the ground, impacting
in a near-vertical attitude.
Fire broke out immediately, consuming t he
occupants.
How do y ou stop pilot s killing t hemselves in t his
way? It's such a terrible waste of life. Of the
t ot al population of pilots, the vast majority will
recognise their own limitations and not even consider such temptations. A small minority will
eventually kill t hemselves no matter what their
colleagues say or do. In between t hese two
groups is a small floating population of pilots
who t hrough their inexperience or personality,
may still be tempted to try such foolishness. It is
still possible to influence t his group. They are
not beyond redemp tion.
This is not an advocacy ag ainst aerobatics. On
t he contrary, t uition in aerobatics is valuable for
all pilots as are regular refresher courses for
t hose of us who spend our normal flying hours
right-side up. There are excellent aerobatic aircraft and instructors who will gladly teach Basic,
Intermediate and Adv anced a erobatics. From
t his, a pilot can go on to display flying when he
or she has sufficient experience and is approved
t o do so.
My concerns relate to illegal low flying, beat -ups
and imprompt u displays. All I can as k of pilots
who indulge in t hese practices is:
• If you mus t do it , then at least spare your
family and friends the added grief of having to
watch you die.
• If you must do it, don 't do it in public.
• If you must do it, don 't carry passengers.
• Or, bett er s till, if you mus t do it, learn how to
do it properly, i.e. in a suit able aircraft , from a
qualified aerobatic inst ructor and within the
limits that in structor will impose for your level
of experience.
If you know of a pilot who is inclined to do these
dangerous manoeuvres, t hen it is your responsibility to either stop them flying, stop t hem flying your aircraft, stop them flying in your club,
tell your CFI or at the very least, tell anyone
who is likely to fly wit h t hem, not to D
Aviation Safety Digest 131 I 5
�How does he accomplish this?
I
Strike one .
DI you're out!
(again)
• •
The human factor in agricultural
operations
The following article was written by John Freeman.
Examiner of Airmen (Agricultural Operations). from the
Adelaide office of OofA. John is an ag. pilot and operator
of some 25 years · experience. It amplifies previous
articles in the Special Ag. Issue of the Digest. John's
point is that most strikes take place with previously
detected wires.
OR THE AG. PILOT to live a full, happy
and productive life he must not have a
wirestrike. Wirestrikes are usually followed
by one of three things:
• The aircraft crashing out of control, killing the
pilot.
• The aircraft crashing out of control, seriously
injuring the pilot.
• The aircraft crashing out of control and the
pilot escaping injury thanks to aircraft design
for survivability.
On the odd occasion, the pilot maintains control
of the aircraft and lands. He then buys a lottery
ticket as quickly as possible before his luck
deserts him.
What causes a highly tra!ned and often
highly experienced pilot to strike wires
with his aircraft?
To avoid striking wires associated with a
particular treatment area, the ag. pilot must do
three things:
(1) Prior to treatment he must locate all wires
associated with the treatment:
in the treatment area
around the treatment area
within the manoeuvring area
(2) Prior to treatment he must locate all
obstacles in close proximity to, and particularly
beneath, the wires.
(3) During treatment he must be able to recall
quickly all of the above until the treatment, including clean-up runs, is finished.
6 I Aviation Safe ty Digest 131
(1) By using the following indications of wires, in
order, and then by visually locating the wire
itself:
• towns, settlements requiring power
• dwelling houses, sheds, pump sheds, etc. which
will have power connected
• the poles that carry the wires, be they steel,
concrete or wood
• the crosstrees on the poles which allow more
than one wire in a run to be carried
• the insulators which join the wires to the
poles.
All the foregoing indicate the wire position.
Remember that having located the indication, the
wire itself must be located. One doesn't hear of
indicator strikes, only wire strikes.
One other consideration is that wires place stress
on poles. If the stress is in a straight line, the
poles themselves will absorb the stress, at times
helped by guy-wires in line with the wire run.
Any deviation in the wire run, however, will
place extra stress on the pole which eventually
will require extra bracing through 'guy-wires
placed on the opposite side to the direction of
stress. Guy-wires, if anticipated, are easily
located. They often have a wooden protective
piece tied to them which shows up clearly.
In any case, any change in a wire run, i.e. an
extra crosstree, extra insulator, different
insulators, pole or crosstree placed differently,
pole leaning etc. must be treated with suspicion
and fully scrutinised before treatment
commences.
Wirestrikes are not just confined to within and
around the treatment area. Wires can be
contacted while manoeuvring due to emergency
landing, downdraught activity, turbulence or
undulating terrain. Therefore wherever the aircraft is likely to be 300 feet and below, the wires
must be located.
(2) It's a fact of life that if you run under a wire
during treatment you are likely to find a problem
under it or near it, i.e. a post or iron dropper, a
poorly briefed marker, a spectator, turbulence,
undulations, trees, bushes, etc. To avoid this and
the obvious result you must look, anticipate and
properly brief personnel. If you don't, Murphy
will ensure that eventually you will have to
choose between an obstruction or the wire. One
hell of a choice if the obstruction is a human
being.
If you are faced with such a choice and it's not a
human being the obstruction usually beats the
pants off the wire if you have to hit something.
Control is more likely to be maintained after·
contacting a wooden or iron post than after
contacting a wire.
(3) When the wires and associated problems have
been located the ag. pilot now has to remember
them. Usually the treatment area is partly
affected by wires, therefore the ag. pilot, while
remembering the wire, can ignore it where it
doesn't immediately affect him.
1
However, read on!
Seven wirestrikes in ten are on wires previously
located. If the wire is so life threatening - and it
is - how is it possible to forget it? The answer
lies in supermarket shopping. Go shopping
without a written list, remembering as many
items as you are comfortably able to. Just prior
to entering the supermarket have someone ask
you to get a couple of extra items or strike up a
conversation with a friend. When you come out
you will find you have forgotten some of the
original items and not necessarily the unimportant ones.
When treating an area the ag. pilot has to
remember:
• the location of wires and other hazards
• his application rate and how far the treatment
has progressed consistent with pesticide
dispensed
• his fuel state
• the location of susceptible crops nearby
• the avoidance of nuisance areas
• possible areas of turbulence
• areas requiring clean-up
• encroaching rising terrain
• areas not to be sprayed during his spray-run
with corresponding shut-off, open-up and
clean-up required
• whether the markers are tracking correctly
• whether the wind is rising, falling, changing
direction
• etc., etc.
This is hard enough without cluttering his brain
with items that are not important in the air, such
as:
• the general progress of the job
• the day's work
• water supplies
• AVGAS supplies
• chemical supplies
• marker availability
• the effect of the weather
• aircraft and spray gear serviceability
• etc., etc.
These latter items are all ground items and are
not to be taken into the air: when the ag. pilot is
in the cockpit, aircraft loaded, engine running,
about to close the aircraft door and somebody
comes running up to say that the chemical hasn 't
arrived, the A VGAS isn't available, his wife
rang, there's another 500 acres to spray before
leaving, etc. he is now set up to strike that wire
he has b~en working around, or which crosses his
clean-up run.
To summarise: things that can only be dealt with
on the ground must be left on the ground otherwise that distraction will kill.
In recognising the limitations of human memory
he can also take the precaution of drawing a
'mud map' which notes the location of all wires
and obstacles. Even if this map can 't be u sed in
flight it can be u sed to jog the memory between
flights and the action of drawing the map
reinforces the image of the treatment area.
Accident records clearly show that the most
likely candidate for a wirestrike is the ag. pilot
who is also:
• an owner-driver
• in charge of the operation
• married or otherwise attached
• between 35 and 45 years old
• experienced with 4000 + hours ag. flying
• trained before 1980.
This man is the likely candidate. However, ag.
pilots who don't fit this picture but who do not
fully survey the treatment areas, locate the wires
and then remember them by leaving the ground
items on the ground, have a better than even
chance of striking a wire. In this event only luck
or good aircraft design will save them as they
are no longer in control of their destiny. D
Aviation Safety Digest 131 I 7
�• Our pilot had developed the habit of conducting long shallow approaches because he believed it gave him better control of the landing.
• T he pilot was distracted to look down in to t he
cockpit t o select the carby -heat during this
most critical phase of the flight .
Things that go
thump in the
night
Figure 1: A shallow but constant approach.
Runway aspect constant and position in windscreen
constant.
"
HE PILOT was conducting a Night VMC
. flight to maintain recency ; the flight con,! sisted of a short cross-country to Narrogin
for a night landing and return to J andakot. He
had a Class 4 Instrument Rating, issued within
t he previous 12 months. He had flown s everal
times at night since then but had not landed
away from Jandakot since the Rating test. The
test had included a night landing at Narrogin.
Approaching N arrogin, the pilot triggered t he
pilot-activated lighting and saw the airfield
directly ahead. He descended to 2000 feet on
QNH , entered the circuit and completed an AL A
inspection at an est im ated 80 feet agl. He noticed
that there were two rows of trees on the extended centreline, about 300-600 m etres from t he
threshold.
The pilot climbed to circuit height , completed his
downwind checks and turned on to final at about
700 feet agl. When he had lined up he realised
that he was a long way out and shallow. As he
continued the approach he realised he had not
selected the carby-heat . After attending to this
he realised he was too low. He applied power and
raised the nose. There didn't seem to be an
immediate response. At this st age, there was a
'thump ' and the nose of the Warrior pulled to the
left. The pilot was able to m aintain control and
as he could s ee no damage to t he left wing,
assumed that it was the left undercarriage tha t
had struck the trees. H e elected to continue the
approach as he did not know the extent of any
damage and how t he aircraft might behave in an
overshoot (go-around).
The aircraft landed safely . The leading edge of
the left wing was badly damaged by impact with
the dead branches "of a tree.
Several factors are significant:
• The obstacle-free gradient (including the treetops) was 3 per cent or about 1 V2 degrees, that
is the trees were a bout 15 metres high and
about 500 m etres from the threshold. On a
normal approach the aircraft should clear
t hese b y 10 m etres (33 f t on a 3 degree or 5
per cent glideslope).
• T he runway had a 1 p er cent downslope which
generally would delude t he pilot into believing
tha t he was lower t han he really was, even or:i
a norm al glidepath.
8 I Avia tion Safety Diges t 13 1
To hit t he tree-tops the pilot m us t have been
either on a shallow ( < 1 Y2 degree) approach pat h
or descending towards a point short of t he
threshold. In t he fir st ins tance, t he aspect of t he
runway would have been grossly flattened but
constant (assu ming constant I AS, W/V and aircraft configuration ). See Figure 1. In t he lat ter
case the runway aspect would have b een flat tened , getting flatt er and moving up in t he windscreen (same p rovisos). See F igure 2.
Final approach t o an ALA at night offer s a
paucity of v isu al references , part icularly where
t here are no peripheral cues su ch a s lights or
reflections in the undershoot area. I n such a
sit uation, the pilot has only t he run way lights a s
a reference for bot h t he app roach gradien t (st eep
or shallow) and for trends (flatt ening, st eepening,
overshooting or undershoot ing ). Such angles and
changes are subtle and require dedicated concentr ation. For a nig ht app roach it is even more
crit ical that all 'housework ' (checks etc.) b e ou t of
t he way and all lig h ts adjusted and set before the
final approach.
T he approach should be no steeper and no
shallower th an daytime. If like our pilot, you
have lap sed into 'subm arine' approaches as a
means of achieving a sm ooth touchdown near the
t hreshold, you are sett ing you rself up for some
form of imp act short of t he t hreshold. It is a
misconcep tion to b elieve th at a shallow approach
gives better cont rol of the speed and t ouchdown
point . A short-field approach is a slower
approach but not a shallower approach .
The alt imeter is also a useful guide. As you roll
out on final the altimet er should read about 500
feet agl (if you fly a st andard circuit). When you
are a good runway-leng th (s ay 1000 metres) s hort
of the t hreshold you s hould be at about 150- 200
feet agl. Don 't look inside to the det riment of
your visual a ssessm ent of the approach - ju st a
quick glimpse of t he alt imeter as a cross-check of
how you are going .
The essence of a g ood landing is a const ant
approach and this comes from self-imposed consistency, day and night. If y ou are not consist ent
you have no reference, no ba sis for judgment .
Consequently, your appreciation of how t he
runway-light 'picture' s hould look m ay be wrong .
Irrespective of such considerations , if it d oesn 't
feel righ t, even if you don't know why, go arou nd
and set up another approach .
Figure 2: A shallow, undershooting approach.
Run way aspect flattening and moving up in the
windscreen.
Having said all t his, the pilot in t he example is
t o be commended for put ting t he aircr aft on t he
ground safely and then analysing t he problem.
H e did not risk a go-around in a damaged aircraft and t hat' s a lesson for all of us D
What a drag! . . . minimum
rpm for feathering
The following was prompted b y and partly produced from
an article in our sister publication, New Zealand Flight
Safety.
H E B R ITI SH CAA has recently drawn
att ent ion to a design feature of most comm on
constant-sp eed p ropellers in use on ligh t
twin-engine aircra ft - for ex ample Hartzell and
McCauley propellers. The propeller s incorporate a
feature which prevent s the blades g oing t o t he
feat hered position when t he propeller is turning
at low rpm .
The reason for t his fea tu re is to prevent t he prop eller from feathering when t he engine is shut
down. Hence it will remain in a fine-pit ch position for the subsequent st art.
The propellers include centrifugal latches which
hold t he blades at fine pitch as the rpm reduces
below 700- 1000 rpm. Consequently the propeller
cannot be feat hered below t his range.
In flight t he windmilling speed of t he propeller
on a failed engine could fall below this range and
prevent fea thering . This is part icularly likely in
t he case of a seized engine due t o mechanical
failure or loss of oil, where the rpm decay can be
rapid.
The usual procedu re in t he even t of an engine
failure is t o control t he aircraft , ident ify t he
failed engine (dead leg, dead engine) and then to
confirm the failed engine by checking for
response to t hrottle movement . I n my case I was
t aught to open t he t hrottle first and t hen close
it. If there was no response the failed engine was
confirmed. T he CAA suggest t hat, if windmilling
rpm has fallen below the latching range, opening
t he t hrott le will usually increase t he rpm suffi~
cien tly t o improve the probability of succes sful
feathering.
The CAA is qu oted as saying:
T
The loss of performance associated with a stopped
propeller in fine p itch, or more importantly wit h a
windmilling propeller, is potentially serious. The
ad ditional drag will considerably reduce the singleengine climb performance from t ha t available with a
fully fea thered propeller. Directional controllabilit y
will also be reduced , t hough adequate control
should still be available down to minimum con t rol
speed (Vmca) as [this speed] is determined with the
propeller in th e condition prior to feathering action
by t he pilot . .. It will probably not be possible to
trim t he aircraft on the rudder trim at t he best rateof-climb speed, and a con siderable foot-force may
have to be held to maintain h eading. It cannot be
overemphasised t ha t, if it is necessary to gain or
conserve altitude, t he best av ailable performance is
essential, and for t his t he best engine-out rate of
climb mus t be maintained .
TO DO THIS THE BEST SINGLE-ENGINE RATE-OFCLIMB SPEED (Vyse) MUST BE MAINTAINED 0
Avia ti on Safe ty Digest 131 I 9
�The seat of the
problem
The chain is as strong as its weakest
link
. N ANY AIRCRAFT system, there is a human
~ element. The flight control s~stem re9uires a
human manipulator. The engme reqmres a
human controller. The electrical system requires
a human operator. The fuel system requires a
human selector. All systems require a human
estimator, monitor and decision-maker.
The critical link then is between the pilot and the
systems. The cockpit is the space where t he
human operator 'interfaces' with the aircraft and
its systems. The controls and displays are there
to enable the pilot to monitor, manage and
operate those systems. The controls have not
always been well designed, logically arranged or
easy to operate. The displays have not always
been reliable, easy to read or well positioned. But
designers are now taking more care with
ergonomics, the science of making the manmachine interface as efficient as possible.
Of course, a vital factor in this interface is the
physical position of t he human operator in relation to the controls and the means of keeping
him or her there. The design of the pilot's seat is
critically important in respect of range of adjustment, support, comfort and strength. The seat
and the restraint system are designed primarily
for the rapid deceleration case - the sudden
stop. Often the st.r;ength of the seatback in a
rearward direction is substantially less. The seatback is also vulnerable to wear, damage and
fatigue as passengers and crew often lean heavily
on it when entering or leaving the aircraft. Seats
with adjustable rake (seatback angle) can experience weakening of the locking assembly. Similarly, the seat-track or rails and its locking
assembly can wear or be damaged.
The consequences of a failure of the seatback or
the fore-and-aft locking mechanism can be
catastrophic. If the pilot cannot reach the controls then in some circumstances the aircraft will
crash. Let's be quite clear on this - a simple
10 I Aviation Safety Digest 131
failure or unlocking of the seatback can cause the
loss of the aircraft and all on board. A worn or
unlatched fore-and-aft lock can similarly cause
loss of control. And over the years, several aircraft have been lost for precisely these reasons.
Imagine on liftoff, the seat fails and the pilot
falls backwards. He is holding the control column
and the throttles ...
These are not hypothetical situations. Such
simple failures have caused many serious.
accidents in the past. Of a total of 27 accidents
and incidents on the files of the Bureau of Air
Safety Investigation the following are typical:
May 85
Tobago
Seat slid back during taxiing. Pilot could not
operate the brakes properly, collided with
another aircraft. Cause: seat not locked.
May 84
Cessna 188
The aircraft's tail rose on landing and it slowly
overturned. The aircraft was substantially
damaged but only minor injuries sustained.
Cause: the pilot inadvertently applied harsh braking when she slipped forwards and out of her
shoulder harness. Because of her small size, she
was not adequately restrained by the harness.
Mar. 83
Cessna 210
During the flare for landing, the seat collapsed.
Cause: fatigue of component.
Feb. 83
Aero Commander 680
The back of the pilot's seat failed during the
climb. Cause: retaining bolts had sheared due to
normal wear.
Feb. 83
Cessna 180
The back of the pilot's seat failed on takeoff. He
lost control and the right-hand main landing gear
collapsed in the subsequent ground loop. The aircraft was destroyed. Cause: fatigue crack.
Aug. 82
Merlin
As the pilot applied takeoff power, the seat slid
backwards. The takeoff was aborted. Cause:
incorrect installation of seat.
June 82
Cessna 185
The pilot moved his seat forwards on downwind.
The seat moved backwards during landing. The
pilot lost control of the aircraft which tipped
onto its nose. Cause: seat not locked.
Jan. 80
Piper P A-38
Seat slid back during takeoff. Pilot managed to
regain control of the aircraft and land normally.
Cause: incorrect installation.
Dec. 79
Cessna 180
Seat lifted off track during taxiing. The uncontrolled aircraft collided with a mound which tore
off the right-hand main landing gear. Damage
was substantial. Cause: seat and harness not
secured.
Nov. 79
Cessna 180
During takeoff the pilot's seat slid rearwards.
The pilot was unable to reach t he rudder pedals
and lost directional control. The pilot closed the
throttle and shut down the engine. The aircraft
was substantially damaged as it swung around.
Cause: seat not properly secured and maintained.
Jul. 79
Cessna 185
The pilot's seat slid off its rails during the landing roll. Cause: stops left out during servicing.
May 79
Cessna 180
During the takeoff run the pilot's seat slid to the
rear. The pilot closed t he throttle but was unable
to maintain directional control. The right wheel
dug in and the aircraft tipped over. It was
substantially damaged. Cause: seat not locked.
Feb. 78
American Aviation AA5
Seat slid backwards on takeoff. Cause: seat not
locked.
May 76
Cessna 172
The pilot's seat slid rearwards and the pilot
could not apply the brakes. The aircraft was
substantially damaged in an ensuing collision.
Cause: seat not properly locked.
Feb. 76
Cessna 180
Pilot's seat slid back on takeoff. The aircraft was
substantially damaged in the subsequent ground
loop. Cause: seat incorrectly fitted.
Jan. 76
Mooney 20
The pilot's seat slid backwards as power was
applied for takeoff. The aircraft veered off the
runway. Cause: seat not locked.
*The relatively high proportion of occurrences
involving tailwheel-configured Cessna aircraft is
noteworthy.
For whatever reason, the failure or movement of
the pilot's seat can be catastrophic. Most of the
above pilots survived unscathed. The main
reason for this was that the seats failed or slid
during taxiing or early in the takeoff roll, when
power was applied. This will not always be the
point of failure although it is the most likely.
Consider again our scenario of seat failure on liftoff. It has happened at least three times that I
know of. One was a first solo:
The student taxied back to the holding point. So
far, it had been a reasonably con sistent period of
circuits although he was annoyed at his stupid
mistakes - particularly forgetting the downwind
call. The instructor looked across at the student
and grinned reassuringly: 'Do the n ext one on
your own.'
The student felt both excited and unsure. He
knew he could fly all right, but up there, alone?
He swallowed, wiped his palms on his t rouserlegs and smiled back weakly.
'Don't forget to listen for instructions from the
Tower and take your time. If you are not h~ppy
about the approach - go around. You're in command, good luck.' The instructor climbed out of
the aircraft, secured the harness and locked the
door. He stepped down off the wing, gave a
'thumbs-up' and slapped the fuselage.
The student looked at the empty seat next to
him with a mixture of relief and apprehension.
He double-checked the pretakeoff vital actions,
changed to Tower frequency and called 'Ready'.
After the Cherokee on short final had passed, he
lined up. He felt good but his palms were still
sweaty. He wiped them once more, checked the
Cherokee was clear, confirmed his clearance and
opened the throttle wide.
The 150 accelerated smoothly and he felt the
thrill of the takeoff roll. No matter how often he
did it, it always had t he same effect. The aircraft
seemed to leap ahead and although he could have
rationalised the cause as being the reduced
weight, he was more interested in making a good
takeoff to justify his instructor's faith in him.
He could feel the flight controls becoming effective as he maintained a presentably straight
takeoff roll. He eased back on the control column
and the nose came up towards the takeoff attitude that his instructor had drummed into him.
This was going to be his smoothest takeoff yet.
He felt the weight of the aircraft lifting off the
wheels and he was about to look along the side of
the nose to maintain runway direction when his
seat gave way.
It took a split second to comprehend what was
happening. He was falling backwards. He still
had the controls in his hands. The nose of the aircraft was rising. He could no longer see the
horizon. In desperation he let go of the controls
and as he fell, he grabbed the throttle.
With the throttle closed, the nose of the aircraft
immediately began to pitch down, although he
couldn't see this. The airspeed decayed and the
aircraft touched down nosewheel first and bourJ.ced. By now much of its energy was dissipated
and the second touchdown was firm but permanent. The aircraft swerved sideways and stopped
in a very short distance.
There was a smell of burnt rubber. Only then did
he realise the engine was still ticking over
althou gh he knew the propeller must have touched the ground during the landing. He pulled the
mixture control and switched off the ignition and
battery switches . He suddenly awoke to the
noises and bustle around him - the siren, the
voices and the spraying liquid. Somebody swore
and told him to get t he hell out of there. He felt
a bit panicky as he undid his harness and struggled with the door. The door was almost wrenched out of his hands and a massive gloved fist
reached past him and t urned off t he fuel cock.
When his feet touched the ground, they felt
remote and his legs wavered when they first took
his weight. He was overwhelmed with relief and
a joy-to-be-alive. His hands shook visibly. H is
voice was similarly unfamiliar and uncontrolled.
The instructor reached the wreck as the fire crew
were jokingly supporting the wavering and, by
now, rapidly talking student. The instructor had
run the length of the airfield. He looked little better than the student. The tale of the first-solo
student is a true one. Thank God he let go of the
control column and grabbed the throt tle.
Aviation Safety Digest 131 I 11
�If you are not el igible for a free issue, or if you would like additional copies of the Digest:-
The pilot of a Cessna 180 was taking off. As he
was about to lift off, the back of the seat failed.
He let go of the control column as he fell
backwards and his feet lifted from the rudder
pedals. He managed to reduce the power to idle
and he pulled the parkbrake handle full on. The
aircraft ground looped and the right main landing gear was broken off. The propeller hit the
ground and the right wing was bent upwards.
The aircraft was damaged beyond repair.
Again the pilot had the instinctive reaction to let
go of the control column and close the throttle.
A Digest reader described the tale of his nearmiss, condensed as follows:
On entering the Cherokee 140, I adjusted the
seat and thought I had locked it. Shortly after
takeoff, the seat suddenly slid back. The nose
immediately rose and I had to push on the control column to avoid a stall. I was pushing with
all my strength and could not risk taking one
hand off for long enough to try to adjust and
lock the seat. I waited until the aircraft had
climbed a little further and then made a grab for
the trimwheel. After several attempts I managed
to wind it forward enough to allow me to let go
of the controls long enough to adjust and lock
the seat.
Once again a potentially disastrous situation well handled. The nose-up pitching moment was
due to the high power setting. The pilot did not
want to reduce power until he was safely clear of
the ground. Why the takeoff trim setting did not
counter the pitching moment is not clear;
possibly due to an increasing airspeed. The
apparently high control force was probably due
to the rearward seat position and the stretch
necessary to reach the forward control position.
However, at least a partial power reduction
would have helped. Quite a dilemma. It is significant that this pilot has unusually long arms. If
he hadn't, then his only option would have been
to reduce power. He now checks the seat lock on
entry and during the pre-takeoff vital actions.
The seat failure accident is a preventable one.
Pretakeoff vital actions include 'hatches and
harnesses '. When you check the harness make it
an automatic action to also check that the seat is
locked fore-and-aft, that the seat rake is locked
and that the seatback is sound. I check this by
trying to slide my bum back and forth and by
trying to push the seatback back. In the process
I may be causing additional wear on the seat
assembly. So be it. I would rather cause a failed
seat during a ground test than have it fail at a
critical stage of flight.
Also check the seat when you first strap-in and always do it, even if you are only taxiing to
the refuelling point.
Perhaps most importantly of all, mentally
rehearse the seat-failure situations, so you know
that if the occasion arises your reaction will be
automatic and correct.
As far as the inflight adjustment is concerned I
consider this to be decidely risky. If the seat is
correctly adjusted in the first place there should
be no need to adjust it in flight . If there is a
need, then a second pilot should be in control
during the manoeuvre~
Like most elements of t he operation of an
aeroplane, the care and feeding of seats is important. Thoroughly brief your passengers on how to
correctly board the aircraft so as to minimise
wear and tear - and include seats as a vital part
of any checklist.
As the Cherokee pilot also pointed out, there
have been several unexplained accidents where
an aircraft pitched nose-up after takeoff, stalled
and crashed. Locked controls? ... or unlocked
seat? D
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12 I Aviation Safety Digest 131
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Aviation Safety Digest 131 I i
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Aircraft accident reports
AGPS
Third quarter 1986
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The following information has been extracted from accident data files maintained by the Bureau of Air
Safety Investigation. The intent of publishing these reports is to make available information on
Australian aircraft accidents from which the reader can gain an awareness of the circumstances and
conditions which led to the occurrence.
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Fixed Wing
Cessna 172-F, VH-DNU, Goodooga N.S.W., 04 Jui. 86,
Instructional - dual.
The pilot in command was continuing a mustering endorsement which had been commenced the previous day. After flying for about 85 minutes the pilots stopped for a break of
some 30 minutes. About 75 minutes after flying had recommenced, a person on t he ground heard a thump and the
wreckage of the aircraft was discovered shortly afterwards.
It had struck the ground, in a steep nose-down attitude while
spinning or turning to the left, about 270 metres to the
south of the strip .
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Amer Air 5-A, VH-SYX, Tangalooma Qld., 06 Jui. 86,
Non-commercial - pleasure.
The first takeoff attempt towards the south was abandoned
because the pilot was uncertain whether the aircraft would
become airborne in the distance available. He noted that t he
windsock indicated calm conditions, and after completing
another engine run, elected to take off towards the north.
Full power was applied before the brakes were released;
however, acceleration appeared to be uneven, reducing as the
wheels passed through soft areas on the strip. The aircraft
struck a fence shortly after liftoff and touched down in a
nose-high attitude. It then bounced several times, struck a
mound of sand and debris, and overturned.
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Beech A-36, VH-MNS, Caloundra Downs Qld., 26 Aug. 86,
Instructional - dual.
A simulated forced landing exercise was planned by the
instructor as part of an endorsement onto the type. The exercise was commenced at about 2800 feet above ground level,
but because of distractions relating to radio transmissions,
engine power checks were not conducted during the descent.
When the throttle was opened at about 500 feet, there was
no response from the engine. The instructor took control but
was unable to prevent the aircraft touching down about 90
metres short of the selected strip. The gear was torn off and
the right wing was severed by a collision with a fence post.
Piper PA31, VH-CJB, Cairns Qld., 02 Sep. 86,
Non-commercial - pleasure.
The pilot hired the aircraft privately from his employer to
conduct a holiday flight during his leave. The journey commenced at Moorabbin on 25 August and the aircraft arrived
at Cairns about midday, 30 August, after a stopover at
Coolangatta enroute. The pilot and his passengers then spent
the next three days at leisure in the Cairns area.
On the morning of the accident, the pilot attended the Cairns
Briefing Office where he collected the relevant weather
forecasts and submitted a flight plan. The flight plan indicated that the flight would be conducted in accordance
with Instrument Flight Rules. It contained a deficiency in
that no details were given for the first sector from Cairns to
Biboohra. This error was not noticed when the flight plan
was submitted.
When the pilot was issued with an airways clearance prior to
departure, it was apparent that he did not understand t he
terms of the clearance, which gave the initial tracking point
as Biboohra. The location of this point was explained to the
pilot and he subsequently accepted the clearance.
T he aircraft was issued with a takeoff clearance which
instructed the pilot to turn right after takeoff. Witnesses
observed that the aircraft complied with this instruction and
headed in a south-westerly direction before turning to the
north-west and entering cloud. The cloud base was estimated
to be between 2000 and 2500 feet above mean sea level. No
further communications were received from the aircraft and
a search was commenced that afternoon. The search effort
was hampered by the weather and the wreckage was not
located until the following afternoon.
Inspection of the wreckage indicates that the aircraft struck
the top of a ridge line, 250 metres south-west of Mt
Williams, while flying wings level and climbing at an angle of
about five degrees.
Amer Air 5-B, VH-IFS, Birdsville Qld., 05 Sep. 86,
Non-commercial - pleasure.
The pilot had held a Private Pilot Licence which had expired
about six months prior to the accident. He reported that
after a normal touchdown, a gust of wind lifted the aircraft
off the ground and that it subsequently landed heavily on
the nosewheel. The nosewheel strut broke and t he aircraft
came to rest in a nose-down attitude.
Beech C-35, VH-AKI, Cheepie Qld., 05 Sep. 86,
Non-commercial - aerial application/survey.
The aircraft was being operated at between 500 feet and
Aviation Safety Digest 131 I iii
�Piper PA32-300, VH-SBH, Waikerie S.A., 22 Sep. 86,
Non-commercial - pleasure.
The aircraft was being flown to Waikerie for a major inspection. While the aircraft was cruising a t 2500 feet enroute, the
pilot smelt smoke and almost immediately noticed oil streaming over the windscreen. He closed the throttle and commenced an approach to a large paddock. The aircraft was
landed without further damage. The pilot vacated the aircraft via the rear door to avoid the billowing smoke from the
engine compartment and attempted to extinguish the fire
with a portable fire extinguisher. On realising the attempt
would be unsuccessful, he collected his luggage from t he
cabin of the aircraft and cleared the area. The aircraft was
subsequently destroyed by fire.
Piper PA25-235, VH-JPT, Burra S.A .. 26 Sep. 86, Aerial
agriculture.
Shortly after the takeoff run was commenced, a large stone
was thrown up by the right mainwheel and struck the spray
boom. The pilot dumped the load and returned for a landing.
The strip was rough and undulating and during the landing
roll the right gear leg collapsed. The right wing then struck
the ground and the aircraft ground looped. The pilot turned
off the electrical system and vacated the aircraft, but shortly
afterwards a fire broke out and consumed the aircraft.
-
De Havilland DH82-A, VH-ART, Kingston S.A .. 27 Sep. 86,
Non-commercial - pleasure.
During the takeoff run, the pilot reported that the aircraft
encountered a crosswind from the left. Despite the application of left rudder and aileron the aircraft continued to move
towards the right of the s trip. The pilot attempted to
manoeuvre the aircraft over a gable marker but one of the
mainwheels struck the marker and caused the aircraft to
turn further to the right. The aircraft continued and the
lower right wing was torn off after it struck a fence post .
The aircraft came to rest 13 metres beyond the boundary
fence.
Beech 58, VH-REH, Lawlers W.A.. 01 Jui. 86, Charter passenger operations.
As the aircraft was accelerating to the normal climbing
speed after takeoff, the pilot lost elevator control. The nose
continued to pitch up until the pilot closed the throttles. He
then discovered that he could maintain limited pitch control
by the judicious use of power. A successful gear-up forced
landing was made; however, during the landing slide, one
wing was torn off after it s truck a tree.
Beech A23-24, VH·TYY, Cunderdin W.A.. 09 Jui. 86, Instructional - solo (supervised).
The pilot was conducting the second leg of his first solo
cross-country exercise. He subsequently reported that during
the takeoff the aircraft failed to become airborne when
expected. Power was reduced in order to abandon t he
attempt, but the aircraft then momentarily became airborne.
The pilot applied forward pressure to the control column to
place the aircraft back onto the ground, but a heavy
touchdown occurred. The nosegear collapsed and the aircraft
slid 183 metres before coming to a stop. After vacating the
aircraft, the pilot realised that he had attempted to take off
with a downwind component of about 10 to 15 knots.
Cessna Al88B-Al, VH-SUA, Rocky Gully, 17 Jui. 86, Aerial
Agriculture.
During the course of the day's activities. the pilot had
landed at the strip on 24 occasions. The surface was wet and
landings had been made with a quartering tailwind. On each
occasion, the pilot had stopped the aircraft about 100 metres
short of a cattle yard at the end of the strip. The pilot was
making his first approach after changing operations to
another paddock. The aircraft touched down about 100
metres beyond the previous touchdown area, and despite
heavy braking the pilot was unable to prevent the aircraft
colliding with the fen ce of the cattle yard.
vi I Aviation Safety Digest 731
Cessna Al88-A2, VH-DOD, Munglinup W.A .. 31 Jui. 86,
Aerial agriculture.
The pilot was engaged in the spreading of urea. During the
operation he had observed that the aircraft was not performing as well as normal. He carried out a trouble check and
a fter the completion of some rectifications and an engine run,
believed he had rectified the problem. Six more sorties were
completed without problem. However, shortly after takeoff
on the next sortie the engine again partially lost power. The
pilot decided to return and land but during the turn toward
the airstrip, t he aircraft stalled a nd impacted the ground
with the left wingtip.
Cessna 150-M, VH-TDP, Mt Magnet W.A., 06 Aug. 86,
Non-commercial - aerial mustering.
The pilot was attempting to take off from an eight metre
wide road. Just after full power was applied, the left maingear overran a windrow on the edge of the road and the aircraft ran off the road. It mounted a one metre high dirt
mound and rolled inverted.
Rotary Wing
Enstrom F28-C, VH-IYP, Carlingford N.S.W., 20 Sep. 86,
Charter - passenger operations.
The pilot had been conducting a series of joy flights as part
of a school fund-raising program. Refuellihg equipment was
positioned some 100 metres from the passenger loading area.
The pilot had offered to take two boys with him as he airtaxied the aircraft prior to refuelling. After takeoff from the
passenger area, the pilot decided to carry out a short local
flight, but as he turned back towards t he fuel dump, the
engine lost power. The pilot was unable to reach a cleared
area and attempted to land in a street. The helicopter collided with trees, then struck the roof of a house before coming to rest on its side in the driveway of the house.
Bell 47G-3B-1, VH-ANG, Coleman River Qld., 03 Jui. 86,
Aerial mapping/photography/survey.
The helicopter was being used in a program of disease
eradication in cattle. After operating for about one hour, the
pilot flew to a boat anchored in the river and hovered
alongside it while signalling to t he crew that the aircraft
would return in about two hours. Shortly afterwards as the
aircraft approached the bank of t he river, the pilot realised
that the aircraft was not responding to control inputs. He
applied more collective control in an effort to avoid flying
into the water, but t he rotor overpitched and the aircraft
struck the water at about 40 knots.
Bell 47G-5A, VH-BHQ, Normanton, 27 Jui. 86, Non-commercial
- aerial mustering.
The pilot was engaged in mustering cattle out of thick
undergrowth. As he was moving the helicopter slowly forward, while checking the undergrowth for any remaining
cattle, the main rotor moved under the overhanging branch
of a large tree. The pilot attempted to move the helicopter
down and to the right but the main rotor struck the main
overhanging branch. The helicopter impacted the ground and
caught fire.
Robinson R22-Alpha, VH-UXV, Camden N.S.W., 16 J ui. 86,
Instructional - dual.
An exercise in emergency procedures was being carried out
in the circuit area. A number of landings were completed,
with the instructor simulating a jammed tail rotor pedal. On
the last landing, a jammed right pedal was being simulated.
After a standard approach for the circumstances, the s tudent flared at about 45 centimetres above the ground at a
speed of about 15 knots. As he t hen began to reduce power,
the engine apparently suffered a substantial loss of power
and the aircraft landed heavily. The left landing skid dug in
and the helicopter somersaulted before coming to rest on its
right side.
Agusta 206-8, VH-LED, Mangalore Vic., 17 Sep. 86, Aerial
mapping/photography/survey.
The purpose of the flight was to film a moving train. Prior to
commencing the operation, the pilot made an aerial inspection of the area and mentally noted the various obstructions.
On the first filming run, the helicopter collided with power
lines at a height of 33 feet above ground level. The helicopter
descended and struck the ground about 50 metres beyond
the point of collision. It then bounced and came to rest on its
side.
Bell 47G-5A, VH-LEF, Old Delamere N.T., 11 Jui. 86, Aerial
mustering.
During mustering activities, the aircraft was operating between 50 and 80 feet above the ground when the engine suddenly stopped. The wind at the time was a quartering tailwind, and during the attempted autorotation the aircraft
struck the ground in a tail-low attitude. The tail boom was
severed, the aircraft bounced, spun to the right, and came to
rest with the landing skids collapsed.
Robinson R22, VH-UXM, Kununurra W.A., 16 Jui. 86, Aerial
mustering.
The pilot had planned to operate for 120 minutes before
refuelling, and the aircraft had an endurance of 150 minutes.
As the aircraft was approaching the refuelling area after a
total flight time of 121 minutes, the engine failed. The pilot
carried out an autorotative landing, but on touchdown one
landing skid became entangled in a large tuft of grass.
Believing that the aircraft would roll over, the pilot applied
rearward cyclic control. The main rotor severed the tail
boom, but the aircraft remained in an upright attitude.
Initial inspection revealed that the engine failed from fuel
exhaustion, although t he low-fuel warning light did not
illuminate.
Robinson R22H, VH-UXQ, Kalannie W.A., 13 Sep. 86, Ferry.
As the aircraft was cruising at 2500 feet above mean sea
level, the pilot noticed a vibration in the airframe. He
reduced the manifold air pressure setting slightly and the
vibration stopped. A short time later the aircraft lost directional control and began to spiral to the right. The pilot was
unable to stop the rotation and when the helicopter landed, it
rolled over.
Initial inspection of t he wreckage indicates that the vertical
fin, tail rotors and tail gearbox became detached in flight.
Gliders
Burkhart twin Astir, VH-IKV, Bundaberg Qld., 27 Jui. 86,
Non-commercial - pleasure.
The glider was being winch launched. The launch was normal
until the glider reached an altitude of about 70 feet above
the strip when t he winch cable went slack. The aircraft was
levelled before commencing a descent and the landing flare
was initiated at about 10 feet above the strip. The aircraft
t hen stalled, landed heavily and bounced. The nosewheel collapsed during the landing roll.
Final reports
The investigation of the following
accidents has been completed
Fixed Wing
Cessna 172N, VH-KZG, Archerfield Qld., 20 Jui. 86,
Non-commercial - pleasure, PPL, 141 hrs.
The pilot was making a- landing approach in eight knot cross·
wind conditions. Witnesses reported that the aircraft was
flared at a greater height above the ground than normal and
it subsequently landed heavily and bounced. The pilot
elected to carry out a go-around, applied full power and raised the flaps. Shortly afterwards, the aircraft stalled and
struck the ground in a left wing low attitude at about
90 degrees to the runway heading.
The pilot had not flown for several weeks, and had evidently
misjudged the height of the aircraft when he commenced the
landing flare. After he applied full power to go-ar<mnd, he
had retracted the flaps while the airspeed was still relatively
low.
Cessna 182R, VH-PJV, Wando Vale Stn., 21 Sep. 86,
Non-commercial - pleasure, PPL, 998 hrs.
The pilot stated that the strip used for landing was a ligned
into the morning sun. On late final approach, he noticed
several kangaroos near the threshold of the strip and decided
to land beyond t he animals. He reported that just as the aircraft was about to touch down, he saw a small kangaroo and
t hen heard a thump. An inspection of the aircraft revealed
that the animal had been struck by the left tailplane.
This accident was not the subject of an on-site investigation.
Piper PA25-235, VH-PPA, Mandurama N.S.W., 01 Jui. 86,
Aerial agricult ure, CPL/Agric. Cl. 1, 14800 hrs.
The pilot left his home base and flew to the strip from which
he intended to conduct top-dressing operations. Shortly after
a normal takeoff with the first load of superphosphate, the
engine power suddenly deteriorated. The pilot dumped the
load and landed in an adjoining paddock, but the aircraft collided with a fence and subsequently ground looped.
No fault was subsequently found with the engine, which was
still operating at idle power when the aircraft came to rest.
After arrival at the agriculture strip, the pilot had left the
engine idling for several minutes with the carburettor heat
selected to the cold position. Atmospheric conditions were
suitable for the formation of carburettor icing and it was
most probable that this had occurred. The pilot had been in
the habit of using reduced power for takeoff, which may
have aggravated any tendency for carburettor ice to form.
Beech A36, VH-MGM, St. Marys N.S.W., 10 Jui. 86, Charter
- passenger operations, CPL/Cl. 4, 3200 hrs.
On arrival in the circuit area, the pilot assessed the wind to
be from t he south-west at 10 knots. He elected to land downwind, as ths strip sloped slightly uphill to t he north-east.
Touchdown occurred about halfway along the strip and the
pilot was unable to bring the aircraft to a stop in the
distance remaining. The aircraft collided with a fence and
came to rest 60 metres beyond the end of the strip.
The strip was undulating, wit h the slope in the landing direction varying from 2 per cent up to 1.5 per cent down. The
average upslope was in the order of 1 per cent and the pilot
evidently misjudged the effect this slope would have on a
landing in downwind conditions. The aircraft crossed the
threshold slightly higher than t he pilot desired and it floated
for a considerable distance under the influence of t he tailwind. After touchdown, the pilot was reluctant to carry out a
go-around because of the s lope.
Piper PA30, VH-CON, Bankstown N.S.W., 20 Jui. 86,
Non-commercial - pleasure, PPL, 224 hrs.
On returning from a flight in the local area, the aircraft was
cleared for a straight-in approach. When the gear was
selected down, the in-transit light illuminated and stayed on.
The gear warning horn sounded and a go-around was made
from short final. Following a flypast, the Control Tower confirmed that the wheels were only partially extended. As the
aircraft was climbing through about 700 feet, there was a
surge of engine power and the aircraft yawed from side to
side, mainly to the right. The pilot assumed that the right
engine had failed, closed both throttles and made a gear-up
landing on the grass alongside.the runway. Initial investigation revealed that t he gear motor circuit breaker had popped.
Aviation Safety Digest 131 I vii
�This was a known fault with the aircraft, although the pilot
had not been alerted to it. Although fuel was found in the
right main and both auxiliary tanks, none remained in the
left main and the left engine system was devoid of fuel.
During his pre-flight inspection, the pilot had evidently overestimated the quantity of fuel in the left main tank. He had
limited experience on multi-engine aircraft and had not been
formally checked on asymmetric handling procedures for
some four years. Under the circumstances, he elected not to
attempt to maintain height on one engine and concentrated
on achieving a safe forced landing.
De Havilland DH82A, VH-ASG, Bankstown N.S.W., 02 Aug.
86, Charter - passenger operations, CPL/Cl. 1, 2000 hrs.
The pilot was taxiing the aircraft along a gravel path in the
direction of a run-up area for runway 36. The duty runway
was 29, and the pilot's request to depart into the north was
not approved. A gentle turn was made to join a marked taxiway but before the aircraft reached this taxiway the left
wing struck a metal sign.
The pilot was aware of the location of the sign but had
inadvertently overlooked its presence.
Maule M5-235C, VH-MEU, Wynyard Tes., 09 Jui. 86, Ferry,
CPL/Cl. l, 1310 hrs.
When the pilot arrived at the destination, the wind was
swinging from south to south-west and gusting from 15 to
35 knots. Runway 23 was unserviceable and the pilot later
advised that there were no suitable grass areas for an intowind landing. An approach was made to runway 26, but during the landing roll the aircraft was affected by a strong
wind gust. The pilot was unable to maintain directional control, and the aircraft ground looped, collapsing the rig ht
maingear.
The pilot was relatively inexperienced on tailwheel-type aircraft. He had elected to make a landing approach after being
informed that the present wind was from 190 to 230 degrees
at 18 knots. This would have resulted in a crosswind component of between nine and 15 knots, while the maximum
allowable for the aircraft type was 12 knots. More favourable
landing conditions existed at other aerodromes in the area.
The pilot had apparently not considered the possibility of
strong wind gusts as he made the approach.
This accident was not the subject of an on-site investigation.
Air Tractor AT301, VH-ODA, Edenhope Vic., 14 Jui. 86,
Aerial agriculture, CPL/Agric. Cl. 1, 7900 hrs.
Towards the end of a spraying operation, the pilot
manoeuvred the aircraft for a clean-up run. This required fly·
ing between two trees before diverting around another tree
and pulling up over a power line. The first part of the
manoeuvre was accomplished but as the pilot applied rudder
to yaw around the single tree, his left foot slipped off the
rudder pedal. He then tried to lift the right wing over the
tree but the outer section of the wing struck a large branch.
The pilot was able to maintain limited control of the aircraft,
which touched down heavily in a nearby paddock.
The pilot had experienced some discomfort of his left leg,
possibly due to his wearing of shoes with lower heels than
those on the boots he normally wore. To alleviate the discomfort, he had placed his foot on the side of the left rudder
pedal, from which it had slipped when pressure was applied
to yaw the aircraft.
Cessna 150-M, VH-WWS, Coldstreem Vic., 10 Aug. 86,
Instructional - solo (supervised), Student, 39 hrs.
The pilot had been conducting a series of circuits with touchand-go landings. Shortly after takeoff for another circuit, the
engine lost power. The pilot pumped the throttle and the
engine responded briefly, but then failed again. The pilot was
committed to a forced landing in an unsuitable area. The
touchdown was heavy, the nosegear was dislodged, and the
aircraft overturned.
The reason for the loss of engine power was not established.
viii I Aviation Safety Digest 131
Rotary Wing
Aerospetiale AS355F-l, VH-NWA, Bankstown N.S.W., 28
.Tul. 86, Ferry, CPL-H, 6800 hrs.
During the downwind leg of the circuit, th~ pilot hea~d a .
sharp crackling noise which was accomparued ~y .a v1~rat10n
in the airframe. He also noted that the transm1ss1on oil
pressure warning light had illuminated. A precautionary
landing was carried out and an initial inspection re.vea~ed
that a transmission cowling had become detached m flight.
The cowling had struck the main rotor disc and a piece of
debris had then hit a tail rotor blade.
The design of the latches of the cowling is such that they
can appear to be locked when they are actuall?' in an
unsecured position. It was possible that the pilot had not
fully secured the cowling during his pre-flight inspection.
However, the locks were not recovered and the precise
reason for the cowling opening in flight could not be
established.
A detailed examination failed to reveal any reason for the
illumination of the oil pressure warning light. It was likely
that the warning was spurious, probably being generated by
moisture around the pressure-sensing switch wiring.
Bell 47-G2, VH-KHL, Bankstown N.S.W., 11 Aug. 86,
Non-commercial - corporate/executive, CPL-H/Cl. 4 with Flt.
Instr., 5180 hrs.
After landing, the pilot was taxiing the aircraft a long a
marked taxiway between two hangars. S~veral aircraft were
parked in the vicinity and the pilot taxied at a slightly
higher level than normal in order to reduce the effects of
downwash. He suddenly noted cables just above eye level
and banked steeply to the left in an effort t.I) avoid a collision. However, the main rotor blades struck and severed
the cables, which were a pair of disused Telecom lines strung
between the hangars, and both blades then struck the
ground.
The cables were not marked, and at t he point where they
crossed t he taxiway t hey were 6.6 metres above the ground.
Final updates
The investigation of the following
accidents has been completed. The
information is additional to or replaces that
previously printed in the preliminary report
Fixed Wing
Rockwell 685, VH-MML, Ben Lomond, 20 Jan. 84, CPL/Cl. 1,
670 hrs.
During the flight the pilot reported that he would descend to
cruise at 500 feet above ground level. Witnesses saw an aircraft at low level on the expected track and others heard aircraft noise and then the sound of impact. Weather condit ions
were overcast with low cloud covering t he hills. The
wreckage was found at an elevation of about 4300 feet above
mean sea level. The aircraft had apparently struck the
ground while in a steep nose-down attitude and rotating to
t he right. A fire had broken out and engulfed the wreckage.
Investigation did not reveal any defect or malfunction of the
aircraft which might have contributed to the development of
the accident. Both engines were operating at high power settings and the gear and flaps were up.
The aircraft had been operating under the Instrument Flight
Rules when t he pilot reported his intention to descend. Conditions at the destination were suitable for visual flight, and
the reason the pilot elected to proceed at a low height above
the ground was not determined. It was likely that while
cruising below t he cloud, the pilot was suddenly confronted
by localised adverse weather conditions in the vicinity of the
accident site. The maintenance of control of the aircraft
under these conditions should have presented little problem
to the pilot, who was suitably qualified to operate in instrument conditions. In these circumstances, the precise
sequence of events leading to the evident loss of control of
the aircraft could not be established.
Piper PA28-140, VH-TVJ, Bankstown N.S.W., 06 Jui. 84,
PPL/Cl. 4, 300 hrs.
About five minutes after his estimated arrival time the pilot
reported that he was uncertain of his posit ion. Attempts to
locate the aircraft were unsuccessful until the pilot climbed
to 6000 feet, and 22 minutes after the initial call the aircraft
was radar identified 78 kilometres north of Sydney. The aircraft was vectored towards Bankstown but about nine
kilometres from the aerodrome the pilot advised that the aircraft was out of fuel. A forced landing was carried out onto a
suburban street, during which power lines and a power pole
were struck.
The aircraft had departed with adequate fuel to conduct the
flight. The pilot had only limited experience with night
operations and had not maintained a detailed navigation log.
He had apparently not been aware of the critical fuel state of
the aircraft until about 10 minutes before engine failure,
which occurred 56 minutes after the position-uncertainty was
reported.
J
J
Beech 58, VH-SWT, Collymongle Stn., 03 Dec. 85, CPL/Cl. 1,
1000 hrs.
As the aircraft was being rotated for takeoff, the pilot
detected a slight loss of performance from the right engine.
He looked towards t he engine and saw evidence of fire
around the air intake on top of the cowling. The takeoff was
abandoned, both propellers were feathered and heavy braking was applied. The aircraft overran the strip and entered a
very muddy field. The nosegear collapsed and the right
engine was torn from its mounts before the aircraft came to
rest 110 metres beyond the strip threshold. The pilot rapidly
vacated t he aircraft and waited for several minutes until
rescuers arrived and extinguished the fire.
The subsequent investigation did not reveal any evidence of
a pre-impact fire and all fire damage was found to have
occurred after the aircraft had come to rest. No positive
reason for the reported power loss was established; however,
tests showed that t he spark from the magnetos was weaker
than normal. At the point where t he takeoff attempt was
abandoned, insufficient strip length remained in which to
stop the aircraft.
Conaero LA4-200, VH·XDH, Strahan Tas. , 11 Dec. 85,
SCPL/Cl. l, 4900 hrs.
The pilot had not previously landed at the particular area
but had carried out a detailed inspection to ensure no debris
was present in the water, which was about one metre in
depth. Almost immediately after touchdown the nose yawed
some 20 degrees to the left and t he aircraft pitched forward
and overturned. A subsequent inspection revealed considerable damage to the hull below the cabin floor.
The investigation discovered that the right-hand nosegear
door had pre"'.iously been damaged. The repairs carried out
had not corrected weaknesses in the door result ing from this
damage.
The area selected for landing on this occasion was too short
for normal operations, and discolouring of the water
prevented the pilot from detecting any obstructions below
the surface. The aircraft adopted a nose-low attitude shortly
after touchdown, but whether this was pilot induced or the
result of striking a sandbank was not established. The
resulting pressure of water on the nose area distorted the
already weakened gear door and forced the left door
sideways into about the normal open position. During the
subsequent yaw and overturn, the right wing and nose of the
aircraft struck the bottom of the river.
Beech 95-C55, VH-TOE, Coolangatte Qld., 07 Apr. 86,
CPL/Cl. 1, 3700 hrs.
Prior to landing , the gear was selected down and a normal
gear-down indication obtained. The touchdown was normal
but when the airspeed was reduced to about 65 knots, a
vibration similar to a wheel shimmy developed. Attempts
were made to keep t he aircraft straig ht with brake a nd rudder but when it was realised that the right maingear was not
supporting the aircraft, the right engine was shut down.
Investigation revealed that the uplock bracket spring had
become detached from the uplock bracket. This along with
some corrosion and stiffness in the bracket pivot bolt caused
the bracket and uplock not to be withdrawn during the
extension sequence. As a result, the extension rod was bent
during the extension cycle and the right gear dip not extend.
There is no provision made for lubrication of the bracket
pivot bolt and no requirement for regular removal and servicing of this item. The pilot was unaware of the gear malfunction due to the design feature of the system which does not
indicate gear-leg position but only the extent of gearbox
travel.
Mooney M20-E, VH-IJN, Camden N.S.W., 07 Jan. 86, CPL,
4500 hrs.
Approaching the circuit area the pilot selected t he landing
gear down but the appropriate gear position light did not
illuminate. The pilot then noticed that all electrical systems
were inoperative. He subsequently advised that he checked
the mechanically operated posit ion indicator and was
satisfied that the gear was down. Witnesses observed the aircraft making a normal approach but then saw the gear collapse shortly after touchdown. Initial investigation revealed
that the aircraft battery was fully discharged.
The aircraft alternator had failed some time previously and
the battery had been steadily depleted. However, this situation would not have been evident to the pilot, as the
ammeter was defective and showed a steady charge a t all
times.
The last part of the gear extension cycle results in a very
small movement of the position indicator and it is considered
difficult to assess the precise position of the gear by
reference to the indicator. The aircraft handbook warns that
a discharged battery may prevent t he gear from fully extending by electrical power. The pilot was aware of this warning
but had not employed the emergency lowering procedure to
ensure t hat the gear was locked down.
Air Tractor AT-301, VH-FRC, Walgett N.S.W., 20 Feb. 86,
CPL/Ag. Cl. 1, 3280 hrs.
The pilot was making night spraying runs over a cotton
crop. During t he third run at about 50 feet above ground
level, the engine suddenly lost all power. The pilot attempted
a landing at slow speed in a flooded cotton field. Almost
immediately after touchdown, t he aircraft nosed over and
sank into the soft muddy surface. The pilot was able to
extricate himself from t he partly waterfilled cockpit.
The subsequent examination of the engine revealed massive
internal damage. It was likely t hat one connecting rod had
failed and this led to similar failures in three other cylinders.
The reason for the initial failure was not determined.
The pilot had selected t he most suitable area available for
the forced landing. When t he aircraft overturned, the
fibreglass roof of the cockpit failed and cut into the top of
the pilot's helmet. Had the pilot not been wearing this protection it was likely he would have suffered head injuries and
probably drowned.
Piper PA60-601, VH-CUO, Lismore N.S.W., 11 Mar. 86,
SCPL/Cl. 1. 2500 hrs.
When the aircraft arrived in the destination area, another
aircraft was also in the circuit. The pilots were in communication with each other and arranged that VH-CUO
would land after the other aircraft. However, t he pilot of VHCUO apparently misjudged the relative speeds of the two
aircraft. He initiated a go-around from a position on final approach to runway 15 when there was evidently insufficient
separation with the preceding aircraft to allow a normal landing. The aircraft remained at a low heig ht above the ground
and t he pilot broadcast a message that he intended to land
in the opposite direction, on runway 33. The wind at the t ime
was from the south-east at about 10 knots. Witnesses
observed the aircraft as it tracked along t he western side of
Aviation Safety Digest 131 I ix
�the runway. The turn onto base leg was made at an angle of
bank of about 60 degrees, and about three-quarters of the
way around the turn the nose of the aircraft dropped rapidly.
The aircraft then dived steeply to the ground and was
destroyed by the impact and subsequent fire.
The subsequent investigation did not reveal any defect or
malfunction which might have affected the operation of the
aircraft. The pilot was conducting an operation known as a
'bank run', and there is pressure on pilots performing such
runs to adhere to the prescribed schedules. The pilot's
decision to perform a low level circuit and land downwind
was considered to be related to his desire to arrive at the terminal as close as possible to the scheduled time. While conducting the circuit, the aircraft stalled during a turn at a
height which was too low to allow the pilot to recover control
before impact with the ground.
Piper PA24-250, VH-RJY, Barraba N.S.W., 09 Jun. 86,
PPL/Cl. 4, 830 hrs.
The aircraft arrived at the destination strip about 40
minutes after last light. Weather conditions in the area were
good, with light winds and clear skies; however, the night
was very dark and there was no visible horizon. Witnesses
on the ground reported that the aircraft seemed to be at a
normal height on the crosswind leg and as it turned onto
downwind. However, it was then seen to enter a gradual but
steady descent. About half way along the downwind leg, the
lights of the aircraft were lost to sight. The aircraft impacted
the ground in a straight and level attitude, bounced ll8
metres, and then bounced and skidded for a further 216
metres before coming to rest.
No fault was subsequently found with the aircraft which
might have contributed to the development of the accident.
The pilot lacked recent experience in night operations. He
had made only two night flights in the previous 32 months,
the most recent being some 11 months prior to the accident.
On the downwind leg of the circuit, the pilot had apparently
not increased engine power after the gear was lowered. He
had also been concentrating on his position relative to the
flare path, and had evidently paid insufficient attention to
the height of the aircraft.
Piper PA60-000, VH-WRV, Bankstown N.S.W., 10 Jun. 86,
CPL/Cl. l, 2100 hrs.
As the pilot approached his destination, he was advised that
he was number three in the landing sequence. A visual,
straight-in approach was made in clear, dark conditions.
After receiving a landing clearance, a normal flare was made
and it was not until the aircraft settled onto the runway surface that the pilot realised that the gear was retracted.
At the end of the landing slide, the pilot turned off the
master electrical switch and vacated the aircraft. He had
made no attempt to a lert the Control Tower to the fact that
the aircraft was disabled on the runway. The controller not
seeing any lights indicating that the runway was obstructed,
cleared a waiting Cessna 172 for takeoff. Only prompt action
by the instructor in this aircraft prevented a collision with
the stationary aircraft.
Beech 58, VH-NSK, Crooble N.S.W., 30 May 86, SCPL/CI. 1,
15000 hrs.
·
At the completion of one leg of the flight, the passengers
disembarked and the pilot prepared to ferry the aircraft to
another aerodrome in preparation for the next day's flying.
The strip in use was constructed of crushed limestone laid on
black soil. The pilot taxied onto the black soil at one end of
the strip as he prepared to carry out a 180 degree turn to
line up for takeoff. The nosegear entered a hole about 150
millimetres deep, and collapsed.
The area where the nosegear collapsed had been affected by
washouts and had gradually become filled with soft silt.
There was no indication to the pilot that the area was
unsuitable. The owner of the property had no flying experience and was probably unware that the condition of the
strip surrounds had deteriorated.
This accident was not subject to an on-site investigation.
x I Aviation Safety Digest 131
Cessna 210, VH-BEC, Ballina N.S.W., 30 Jun. 86, PPL/Cl. 3,
950 hrs.
The aircraft crossed the threshold higher than the pilot
desired and touchdown occurred well into the 730 metre
strip. After initially running normally along the ground, the
aircraft bounced twice before coming to rest in a nose-down
attitude. Investigation revealed that the aircraft had landed
on the left side of the strip, where the surface was very
rough, and the aircraft had suffered a broken nosegear fork.
The nosewheel had become detached and the nose strut was
pulled away from the firewall.
The pilot was feeling fatigued after completing 7 hours flying
for the day. He had elected not to go around when the aircraft was high on the approach, as adequate strip length
remained for a safe landing. The rough area of the strip was
not visible from the air and the aircraft entered this area at a
higher speed than would have resulted from a touchdown at
the normal aiming point.
Cessna 180-K, VH-WSN, Caramut Vic., 14 Apr. 86, PPL, 2541
hrs.
On arrival at his destination, the aircraft overflew the
homestead. This was the pilot's normal practice, to indicate
to persons on the ground that transport from the nearby
strip was required. The aircraft was then seen apparently
following a gully containing a sunflower crop in which the
pilot and passenger were partners. Shortly afterwards the
sounds of an impact were heard. The aircraft was found to
have struck the side of the gully while in a steep nose-down
attitude and probably rotating to the right.
No pre-impact defect or malfunction of the aircraft was
found which might have contributed to the development of
the accident. However, about 12 months previously, the pilot
had applied tape over the stall warning vane, thus depriving
him of aural warning of an impending stall. The wreckage
distribution was consistent with that which follows a stall at
low level where control of the aircraft is not regained before
impact. It was likely that the aircraft stalled while the pilot
was manoeuvring above the crop, but the precise reason for
the stall and subsequent loss of control was not established.
light. As the enroute weather was satisfactory, the pilot pro·
ceeded as planned. However, about 10 kilometres from the
aerodrome, rain s howers and deteriorating visibility were
encountered and the pilot did not consider it safe to continue. There was insufficient daylight remaining to reach the
planned alternate aerodrome and the pilot elected to carry
out a precautionary landing on a sealed stretch of road. The
aircraft touched down normally, but then began to drift to
the right. A go-around was initiated but the tailplane struck
a fence post. The force of this impact almost tore t he tail section from the aircraft. The pilot felt the impact but was
unaware of the extent of the damage until after he had
landed the aircraft in the adjoining paddock.
The road on which the pilot had attempted to land was
narrow, and the approach had been nade in crosswind conditions. The pilot had limited experitnce on the type and had
been unable to maintain directional control under the
existing conditions.
Piper PA32·RT300, VH-MSX, Fraser Island Vic., 08 Jun. 86,
PPL, 80 hrs.
The pilot was approaching to land into the south. The wind
at the time was from the south-west and gusting to about 30
knots. The first half of the strip was sheltered from the wind
by a solid line of tall scrub and trees. The aircraft did not
touch down when the pilot flared for landing and a go-around
was initiated. At a height of about 10 feet and passing
abeam of the end of the sheltered area, the aircraft suddenly
moved violently to the left. The nose dropped sharply and
the nosewheel dragged on the ground for some 10 metres
before the pilot was able to continue the go-around. A diversion to a more suitable aerodrome was made, where a postlanding inspection revealed that the nosegear had been bent
sideways by the previous ground contact.
Because of the turbulent conditions, the pilot had
approached at about 10 knots faster than normal. The strip
was relatively short and the general crosswind in gusts was
probably above the maximum for the type. A post analysis
of the weather conditions indicated that wind gusts in excess
of 50 knots may have occurred in the area.
Rotary Wing
Cessna Al50-K, VH-RAI, Coldstream Vic., 13 May 86,
Student, 28 hrs.
The pilot was conducting a series of solo circuits and landings into a wind of 10 to 20 knots, with occasional gusts to
25 knots. On the third approach, the aircraft had been flared
for landing when it suddenly ballooned and a wing dropped.
Full power was applied but the aircraft sank heavily to the
strip and the nosegear collapsed.
The student pilot had reacted correctly when a sudden wind
gust was encountered ; however, he had been unable to prevent a heavy touchdown.
This accident was not the subject of an on-site investigation.
Beech C23, VH·MRC, Echuca Vic., 05 Jun. 86, RPPL, 365
hrs.
Following a dual check on circuits and landings, the pilot
carried out some upper air work before returning for circuit
practice. The weather conditions were fine, with light and
variable winds. A normal approach was flown but the aircraft bounced slightly on the initial touchdown and this was
followed by two further bounces of increasing magnitude.
The pilot persevered with the landing attempt but the propeller struck the ground and the nosegear collapsed before
the aircraft was brought to a halt.
This accident was not the subject of a n on·site investigation.
Cessna 210-L, VH-SRJ, Ascot Vic., 09 Jun. 86, PPL, 254 hrs.
The pilot's flight plan indicated that he would reach his
destination 20 minutes before last light. During the flight,
this estimate was amended to seven minutes before last
Bell 206B, VH·FHB, Sydney N.S.W., 05 Aug. 84, CPL-H/CI.
4, 375 hrs.
The pilot brought the helicopter to a hover at 1000 feet agl,
pointing approximately into wind. The aircraft began t? yaw
to the right and the pilot was unable to s top the resulting
rotation. The helicopter descended in a steep nose-down
attitude and struck the ground heavily while s till rotating to
the right. The landing skids were torn off and the helicopter
came to rest on its left side.
No mechanical fault or defect was found with the helicopter
which might have contributed to the development of the
accident. It was considered likely that the aircraft experienced the phenomenon known as 'tail rotor breakaway',
which results in an uncommanded yaw to the right accompanied by a steep nose-down pitch change. The pilot was
aware of the phenomenon and had read various articles on
the subject. However, much of the information available at
the time was of a confusing and conflicting nature and the
recovery action employed by the pilot on this occasion was
ineffective.
Hughes 269-C, VH-TES, Cloncurry, 02 Apr. 86, CPL-H, 1720
hrs.
During a mustering operation at 100 feet above ground level,
the pilot noticed an unusual vibration in the aircraft. He
decided to land in a nearby clear area to investigate the
source of the vibration. As the pilot commenced the
approach, the engine suddenly oversped and the pilot
.
immediately commenced an autorotational descent. The wrcraft touched down while still moving sideways and rolled
over.
Inspection of the aircraft found that the short drive shaft
from the engine to the transmission had failed. The failure
was the result of t he shaft overheating due to a lack of
lubrication when the grease-retaining boot on the drive shaft
adaptor fell off. The clamp that held the boot in position was
not found and the reason t he boot was lost could not be
determined.
This accident was not the subject of an on-site investigation.
Bell 206B, VH-LAQ, Cunnamulla, 12 Jun. 86, CPL/Cl. 1, 6052
hrs.
The helicopter was engaged in an inspection of the oil
pipeline between Jackson and St. George. The inspection involved landing at various points along the pipeline to allow
the technicians to check the pipeline. As the aircraft took off
after an inspection stop, the front passenger warned the pilot
about the position of a power line. The pilot attempted to
take avoiding action but the aircraft struck a power line.
Control of the aircraft was lost and it struck the ground in a
nose-low attitude and rolled onto its right side. A section of
the helicopter's transmission was torn from the aircraft and
struck the front seat passenger.
During the day the flight had been delayed by problems with
the inspection schedule and aircraft fuelling. While waiting in
the aircraft for the technicians to complete their task, the
pilot was involved in flight-planning the next stage length to
St. George to arrive there before last light. The pilot
reported that he had seen the power line during the previous
landing sequence but had forgotten about its presence on
takeoff.
Bell 205-Al, VH-UHP, Falls Creek Vic., 09 Feb. 86, SCPLH/CI. l, 6250 hrs.
A group of five firemen had finished a task in a fire-fighting
area and were to be winched out from steeply sloping terrain.
The helicopter hovered at about 30 feet while the first two
men attached themselves to the dual winch hook. They were
then raised to t he aircraft, following which the next fireman
was also lifted. The remaining two men then attached
themselves to the hook. The operation proceeded normally
until the men were close to the skids of the helicopter. At
this point the winch cable broke and the men fell to the
ground.
An inspection of the cable revealed that it had come off one
of the pulleys of the hois t and became jammed. Fraying of
the cable had occurred and it had finally failed in overload at
a point some four metres from the hook. A number of kinks
were found in the cable, possibly resulting from the
operator's maintenance and inspection procedures. Such
cable twisting would have increased the possibility of the
cable riding over the edge of the pulley, particuarly when the
cable was not under tension. Such a situation would occur
when extra cable was paid out to assist with the attachment
of the cable to a person's lifting harness. The length of
frayed cable was consistent with this sequence happening on
the hoist on which t he accident occurred.
This accident was not subject to a n on·site investigation.
Gliders
Scheibe SF25C, VH-GXM, Cunderdin W.A., 14 Jun. 86,
Glider, 289 hrs.
The student pilot was being checked on the Motorfalke
powered glider. At about 50 feet above ground level, the
instructor shut the engine down to simulate an engine
failure. The student elected to land the glider straight ahead
on the remaining runway and the instructor being satisfied
with the student's initial actions directed his attention to
stopping the propeller in the horizontal position. The student
fully opened the s poilers and a hig h rate of descent was set
up. The instructor took control of the glider but was unable
to arrest the high rate of descent and a heavy landing
resulted.
Lighter than Air
Colt 240, VH-NMS, Alice Springs N.T., 15 Apr. 86, Balloon,
240 hrs.
Following a 30-rninute flight, the pilot landed the balloon and
the passengers waited in t he basket for t he retrieve vehicles
Aviation Safety Digest 131 I xi
�to arrive to affect a passenger changeover. During t his
period a strong wind blew up, caught the balloon and
dragged it towards trees. The pilot advised the passengers to
adopt a crouch position and operated the burner to apply
heat to raise the balloon. The balloon climbed steeply,
cleared the trees, then descended rapidly, bounced, and the
basket began oscillating about 30 degrees either side of ver·
tical. The pilot was thrown out of the basket and 10 of the
11 passengers received injuries, although all remained in the
basket. The balloon continued to be blown along the ground
and one of the passengers climbed into the pilot's section of
the basket and applied heat; this took the balloon aloft. The
pilot chased the balloon and after one of the retrieve vehicles
located him, he was able to contact the balloon by radio and
relay instructions on the use of the burner to the passenger.
The balloon landed about 3.5 km from the position it had
been waiting to changeover the passengers.
Corrigendum
The following is an amended version of the narrative of an
accident report described in the 'Final updates' section of
Aviation Safety Digest 130.
De Havilland DH82·A, Bond Springs N.T., Jan. 86,
SCPL/Cl. 4, 3600 hrs.
Analysis of a video recording, taken of the takeoff run by
the occupant of the front seat, indicated that the aircraft
became airborne after a ground roll of about 18 seconds. The
aircraft then continued in the direction of t akeoff for a fur·
ther 11 seconds at what appeared to be near to takeoff
speed. The aircraft did not climb away. It was not clear from
t he recording whether or not the aircraft was airborne
throughout the 11 seconds. At t he end of this time, however,
t he aircraft was on the ground and it then veered sharply to
the right. At the time, t he prevailing wind was a left quarter·
ing crosswind. The pilot was unable to regain directional con·
trol and the aircraft ran off the side of the strip and struck
an embankment before coming to rest inverted.
No defect was found with the engine or flight controls and
the aircraft weight and centre of gravity were within the
required limits. The aircraft had been fitted with a braking
system and had recorded 27 hours in service since the
modification. An examination of the brake shoes revealed an
excessive rate of wear to the left brake shoes, and a cable
within the braking system was found to be incorrectly
adjusted. However, whether these defects contributed to the
development of the accident could not be established.
The reason for the loss of directional control was not
det ermined.
In the corrigendum contained in the Accident Report section
of Aviation Safet y Digest 130 there was a corrected narrative
regarding a glider/tug accident in Tasmania. Unfortunately,
it contained a typographic error. The corrected report is as
foUo ws:
Czech Blanik Ll3, Woodbury Tas., Aug. 84, Glider, 232 hrs.
The student glider pilot had carried out three previous
flights during the day. Her instructor had informed her that
she was at a suitable stage of training to be introduced to
practice emergency procedures. After sighting her training
log book, the instructor for the final flight left the glider to
speak to the pilot of the tug aircraft. The instructor returned
to the glider and preparations for takeoff were then con·
tinued.
Witnesses observed that t he tug and glider became airborne
and subsequently carried out normal turns to position the
aircraft on a downwind leg at about 500 feet agl. The tug air·
craft was then seen to waggle its wings sharply three times.
Almost immediately this aircraft assumed a steep nose-down
attitude, its tail apparently being pulled into a vertical posi·
tion by the tow rope which was still attached to the glider.
The glider then also assumed a steep nose-down attitude and
both aircraft spun or spiralled towards the ground. The tow
rope was released from both aircraft, but neither pilot
regained control before impact with the ground.
The subsequent investigation did not disclose any defect or
malfunction with either aircraft that might have contributed
to the development of the accident.
xii I Aviation Safety Digest 131
During glider towing operations when the pilot of t he tug
waggles the aircraft wings, it is a signal to t he glider to
immediately release from the tow. This 'wave-off' signal
would normally be given when the tug pilot detects some
malfunction or when the glider is sufficiently far out of posi·
tion behind the t ug to affect the tug pilot's control of his air·
craft.
On this occasion, it was considered possible that the instruc·
tor in the glider had arranged for the t ug pilot to simulate an
emergency by giving a wave-off signal. The wave-off signal
was observed to be given in the normal position relative to
the strip for such training manoeuvres to be performed. The
reason for the subsequent loss of control of both aircraft
could not be determined. However, it was evident that when
the aircraft released the tow rope there was insufficient
height remaining to permit recovery to normal flight.
Probable significant factors
There was insufficient evidence available to determine the
precise cause of t he accident. Nevertheless, the following
were considered to be probable factors in t he development of
the occurrence:
1. The gliding instructor and the tug pilot arranged to give
the student a practice emergency.
2. When the wave-off signal was given, the glider did not
immediately release from the tow.
3. Control of both aircraft was lost at too low a height to
permit recovery.
Aviation Regulatory Proposals
Aviation Regulatory Proposals (ARPs) are an important means by which the Department consults
with industry about proposed changes to operational legislation and requirements. Copies of all
proposals are circulated to relevant organisations, and occasionally to individuals for information and
comment. The comment received provides a valuable source of advice which greatly assists the
Department in the development of the completed documentation.
Each edition of the Digest contains a listing of those ARPs circulated since the previous edition.
Should you wish further information about any of the ARPs, please contact your industry
organisation.
Number Subject
Aircraft Weight and Performance
86/7
Limitations
Authorised Landing Areas used for
86/10
ab·initio flying t r aining
Operation of Hang Gliders in Military
86/12
Control Zones
Fuel Requirements
86/15
86/16
Life Jackets
86/17
Second Pilot
Instrumentation
Status
I ssued 27 August 1986
Comments due 15 December 1986
I ssued 30 June 1986
Comments are under consideration
I ssued 26 August 1986
Comments due 1 October 1986
I ssued 20 October 1986
Comments due 14 January 1987
I ssued 20 October 1986
Comments due 31March1987
I ssued 16 October 1986
Comments due 31January1987
Aviation Safety Digest 131 I xiii
�ENTRY FORM FOR THE
.
DIGEST PHOTOGRAPHIC COMPETITION
Nikon
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The Digest is pleased to announce its second
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exposure and manual
over-ride.
Category 2 - For the best picture illustrating a
safety aspect or an unsafe aspect of Australian
civil aviation. A clue in this field is that the primary
contributory fac tor in aviation accidents is the
'human factor'. The judges' emphasis will be the
'message' and how well the p h otographic design
conveys that message.
Category 3 - There will be a specific prize for the
best monochrome print. Black-and- white
photographs in particular are a valuable
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Results will be published in the
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Dear Sir,
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TO: Photographic Competition
Aviation Safety Digest
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Entries close with the last mail on Friday,
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ENTRY FORM FOR THE
DIGEST PHOTOGRAPHIC COMPETITION
TO: Photographic Competition
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Canberra, ACT 2601
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19June 1987
Results will be published in the
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�Sir, I read with interest the article in D igest 129
titled 'Overstressed'. I noticed a mistake in the
article and an omission which I feel is of great
importance and should have been discussed in
the article.
The mistake is where you refer to the PA28's
maximum positive load factor in the utility
category being 3.8 g. An aircraft must have a
positive load factor of 4.4 g to be certified in the
utility category. The PA28 does meet this
requirement [for the ut ility category] or can
operate in the normal category with a load factor
of 3.8 g.
The omission is in not mentioning the effect of
flap on the load factor. While the PA28 manual
does not state flap position when it gives the
maximum load factors, both the P A38 and the
Cessna 152 manuals give positive load factors
with flaps up and flaps down. The flaps down
load factor is nearly 50 per cent less than with
flaps up, i.e. with a flaps up load factor of 3.8 g
the load factor with flaps down is around 2.0 g.
As the article mentions t hat the pilot had over
half flap selected I feel that the above information is pertinent and should be mentioned in a
later edition.
DONAL SMITH
You are quite correct, Donal. The Warrior has
been accepted in Australia under the terms of
ANO 101.22 which requires that the aircraft
meets the criteria specified in the U.S. design
code, CAR 3. CAR 3 lays down the structural
standards for the normal category and t he utility
category. Under the U.S. Regulations for the certification of light aircraft, the manufacturer is
required to provide a structure which can safely
withstand a positive manoeuvring load factor of
3.8 g for it to be certified in the normal category
and 4.4 g for it to be certified in the utility
category . Further the structural design must pro.vide a safety margin by tolerating a load 1.5
times these figures before failure.
Under the terms of CAR 3 the structural
integrity of the Warrior with the flaps fully down
must cope with a manoeuvring load factor of
2.0 g. This value also carries the '1.5 times'
margin before failure.
Most manufacturers include this figure in the
flight manual. For some reason Piper does not.
You may assume that the Warrior has a positive
load factor limit of 2.0 g, flaps down.
xvi I Aviation Safety Digest 131
The Warrior in the article had only partial flap
deflection and could probably withstand a load
slightly greater than 2.0 g. To experience the
damage that it did, it was probably subjected to
a positive load factor well in excess of 2.0 g, and
perhaps in excess of 3.0 g. This pilot was in a
regime where the primary structure could have
been close to catastrophic failure.
Of more concern to me are three other aspects:
1. Aircraft used as trainers and which are hence
more exposed to unusual attitudes and misapplied recoveries, do not have a display or a record
of applied load factor. The onus is on the pilot to
be sensitive to load factor and to report any
suspected overstresses. Our lives depend on each
ot her's integrity in this area.
2. The load factor limits above are for symmetrical loads - any additional rolling moment,
that is any aileron input can cause one wing to
be overstressed even if the total load is within
limits.
3. Another insidious aspect of load factor is t he
sensitivity of the pilot to the rate of application
of the g-force. The pilot may snatch-pull a very
high load factor and immediately release it - he
will have felt only part of the force before it was
released. The structure feels every bit of it.
A pilot in the predicament described in the
D igest article can only do whatever is necessary
to survive. In the process he risks damaging or
breaking the airframe. Indeed many of t he 'VFR
into IFR' accidents result in the catastrophic
failure of the structure before impact. A normal
category aircraft has sufficient strength to
accommodate the loads of normal flight plus a
reserve margin. Any loss of control at the upper
end of the speed range places the pilot in a grey
area between safe recovery and airframe failure;
and I include here t he upper end of the flap
speed range as being just as risky.
In the example it appears that the pilot was in
this situation and did indeed apply both elevator
and alieron to regain a level attitude. I would
suggest that the combination of speed and control inputs exceeded the a ircraft's structural
limits.
Of further concern is the non-detection of the
failure. I would suggest a post-flight inspection
as a worthwhile habit at any time - I do it so I
can detect any unserviceabilities in time to have
them fixed before the next trip (it is particularly
useful for detecting stone damage to the propeller or airframe; or oil, fuel or hydraulic leaks).
After an incident like this a LAME inspection
would have been an investment even if the pilot's
check showed nothing obvious.
I thank you for raising these important aspects
of t he art icle D
Aviation Safety Digest 131 I 13
�I
Pilot workload DI the final straw?
OG I CALLY, all controls in an aircraft are
located so that the pilot can identify, reach
and operate them with ease. Take for
example the primary flight and power controls the control column in the left seat is located so
that it can be easily operated by the left hand
and the power levers are located so that t hey can
be easily operated by the right hand. Therefore,
one does not interfere with the other.
Next, because of the almost cont inuous need to
keep the left hand on the control column, other
ancillary controls are u sually located for operation by the right hand when it is not occupied
with t he power levers. Such an arrangement is
logical and functional.
Problems can arise though when it is not possible
to locate the less important controls in their ideal
position because of space, access or routing. In
some cockpits the trimwheel is on the left; in
others the light switches are only easily opera ted
by the left hand. In these instances the pilot has
to change hands at least momentarily, to operate
the system.
The problem is compounded in IMC and when
the pilot also has to manage the 'paperwork' or
use a computer or write something down. We
left-handers have particular problems as we have
to change hands on the controls every time we
wish to write. Add to t his already high workload
and we are running into problems - big
problems.
Consider the plight of the lone pilot conducting
an ins trument approach into an airport for the
first time. The weather was lousy - rainshowers,
turbulence and reduced visibility. The main
cloudbase was 1000 feet so there was no expected
problem getting in. However, she was having to
work hard to fly within reasonable tolerances.
14 I Aviation Safety Digest 131
Passage over the NDB was accurate under the
circumstances and the pilot entered the holding
pattern to lose altitude and to carry out the
approach checks. There was a marked drift in the
pattern and s he mentally noted t he expected
wind for the letdown and t hat the duty runway
would necess itate a circling approach from the
minima.
She double-checked the QNH and the station
ident and left the coding on low volume. Next
s he organised the letdown plate and her checklist
on the clip board on her lap. She noted down the
ATIS and attached the piece of paper to the
board. The freezing level was forecast to be at
4000 feet and she selected the pitot heat on
before entering the next layer of strato-cumulus
cloud. There was no lightning about but there
was a good chance of rime icing. She hoped that
there would be no need to hold in cloud.
She checked that the fuel was sufficient for an
approach and a diver sion to the nominated Alternate. She checked t he trim indicator and
disengaged the autopilot before descent. The
lower cloud looked lumpy and slie would prefer to
get used to manually flying the plane before
reaching the minima. Because of the need for a
circling approach, she elected to lower the gear
before descent to minimise her workload during
the final leg.
Checks complete, she concentrated on getting a
good 'overhead' before descent. Over the Aid, she
confirmed her altitude, checked the carby-heat
position and reduced power. Already she was
having to make large corrections to stay within 5
degrees of t he outbound track. The turbulence
was getting worse and the rain was making a fair
amount of noise on the airframe. A small leak
near the VHF antenna above her head was causing an annoying drip, drip, drip of water on her
forehead and this was running into her eye.
She wiped her brow wit h the back of her right
hand and 'sweated' on the flight instruments.
The ADF needle was wa ndering occasionally but
the ident was still good.
The water dripped onto the letdown plate making
a distracting little splodge right over the 'circling
minima' column. She had already noted the
minimum altitude. The noise of the rain was getting worse and the turbulence was continuous s haking and bouncing the small aircraft like a
toy.
As she turned inbound, the buffeting became
momentarily worse and it needed large, sudden
control inputs to maintain a sensible attitude.
She noticed a distracting flash over her left
shoulder and before she realised it was the reflection of the strobles on the large water droplets,
her heart missed a few beats and her stomach
tightened.
Steady inbound now, she double-checked her
altitude, kept the wings level and peered through
the wall of shimmering water. She could make
out vague shapes of dark colour below but she
could see nothing ahead. The descent was
approaching the minima and this approach
required an immediate overshoot if the field was
not in sight at the minimum altitude. She did not
fancy climbing back through it all and she
anxiou sly searched ahead for a familiar pattern
of runways and buildings - she had studied the
aerodrome diagram and knew what to expect
from t his viewpoint.
Almost simultaneously , the turbulence reduced
and the rain became broken. As she broke out
A TC called a change of wind direction and asked
her intentions from the minima. She picked up
the 'mike' to reply as she sighted the runway off
to her left. It was tight. She dropped the mike,
grabbed for the flap lever and S-turned onto
finals.
It is always in situations like this that the blessed aeroplane just doesn't want to slow down. She
managed to get the speed within 10 knots of the
planned threshold speed as she crossed t he piano
keys. She knew she had adequate runway
available even at that higher speed.
She was gingerly testing the brakes when the
Tower blithely asked if she had decided what her
intentions were from the minima. She couldn't
remember whether she had received clearance to
land. She thought it ironic that this uncertainty
now caused her more concern than any other
aspect of the flight.
The microphone was still on the floor.
I would like you to imagine t his same letdown
with two further complications:
• The aircraft concerned is not alone in t he
pattern
• There are concerned passengers who interrupt
occasionally in the hope of gaining some
reassurance
The pilot's workload is now getting seriously
high. There is an additional frequent need to
communicate with A TC and with the other aircraft - each time requiring the pilot to reach
down and pick up the microphone. During this
time the pilot's right hand is not available to
adjust the throttles, lower the wheels or trim the
aeroplane. The microphone gives no feedback or
side-tone and in these conditions, the pilot is not
really sure what and how well he is transmitting.
In the meantim,e he occasionally has to shout to
his passengers to ease their concerns or to tell
them to shut-up, if necessary.
Add an additional requirement to write down a
clearance limit, set an ass igned altitude or make
a frequency change and the pilot is now akin to
the 'one-armed paperhanger'.
Now make the pilot left-handed so that every
time he wants to write he has to change hands
on the con trols - he ends up with a pencil in his
left hand between his fingers, and that hand is
holding t he controls. He pick s up t he microphone
to transmit with his right hand. The reply has to
be written and read back. The right hand, still
holding the mike, grips the controls somewhat
insecurely and t he left is now free to write. O!after each call, he places the mike back in its
holder before changing hands. It all takes time
and during this procedure the aeroplane' is
making its own decisions about which way is up.
Now, just as he changes hands to write the information, give him an engine failure ... (real CFI
stuff this).
The point I am trying to ma ke is that a pilot even one as competent as our example - has a
high enough workload as it is. Don't make it any
harder. Our pilot had planned ahead and was
organised before t he descent from the initial
approach fix. Even then, the workload was high
enough to make her susceptible to error with
only a minor increase in distraction.
She coped well. She may have had an easier time
of it if she had a headset and a press-to-talk
button on the control wheel - one easily reached
with the thumb of the left hand while flying normally. Such a system allows communications
with no additional workload. The pilot hears via
the sidetone, what he has said and how clearly.
It may be garbled in the transmission but it is
better than having no clue at all. Similarly, a
system which allows the pilot to talk to his
passengers via an intercom also allows him to
talk in a normal calm voice without increasing
his workload. The passengers are better soothed.
At the same time, passengers without an intercom can be excluded from t he pilot's audio
environment.
With a head set, the pilot can better hear and
understand incoming calls without the interference of cockpit noises. Similarly the pilot's
transmissions are easier to understand when the
microphone is held in the optimum position in
front of his mouth. The headset does this for
you.
The argument against headsets has been t hat
cockpit audio warnings can be lost. Maybe so.
The audio warnings should be accessible via the
headset. If not, I am not concerned. I'll tell you
why:
• The simple stall warning syst em is not always
a valid warning anyway, i.e. it often sounds
during turbulence and perhaps during takeoff
and landing so it becomes less alarming.
• There are 'natural' stall warnings.
• The undercarriage 'not down' warning
operates when the throttle is closed below a
certain value which is often on landing, i.e.
when it's not too late to do a nything about it.
• The more complex warning systems can be
operated through the headset and combine
audio with visual warnings.
• Even complex alarms have not eliminated the
possibility of landing 'wheels up'.
As you can guess, I am strongly against handheld microphones and I urge you a ll, even if you
are right-handed, to use a headset and press-totalk button. Be a two-armed paperhanger D
Aviation Safety Digest 131I15
�Circuits and
bump
~.
~
DECISION made under the pressure of time
has to be made, for better or worse. It can't
_
be put off. The chances of this decision
being a correct one can be dramatically improved
by mentally rehearsing the possible and probable
emergency situations and by imagining the
possible consequences of each course of action.
If you then reinforce the selected course of
action:
• by discussing it with your instructor and
colleagues
• by rehearsing it in your mind
• by sitting in the aircraft and going through
the physical motions in conjunction with your
mental rehearsal
• by practising in a simulator
when the real emergency arises, your actions (the
ones already selected as being the most correct in
those circumstances) become almost automatic.
This not only saves valuable time, it reduces the
mental workload and allows you to be planning
your landing, advising air traffic services or
briefing your passengers while you are coping
with the situation.
Perhaps the most critical phases of flight are
takeoff and landing. However, they are made
even more critical in three particular situations:
• a go-around from short final
• an aborted takeoff
• a touch-and-go.
The reason for this is the high workload - the
pilot has to complete a complex series of correct
actions and correct judgments in a very short
space of time. There is a reduced margin for error
and there are usually several distractions.
The touch-and-go is at least preplanned, but on a
marginal length runway or if the sequence is
interrupted it can rapidly become an uncontrolled
situation.
The following is an embellished description of a
real incident:
An aerosol can was one of many items found by
the maintenance staff during the 100 hourly servicing. The Warrior was generally well looked
after and the can contained a cleaning agent for
the windscreen. It was in the baggage compartment with several rags, the tie-downs and a pitot
16 I Aviation Safety Digest 131
cover. The LAME collected these items and put
them in a cardboard box which he tied down in
the compartment.
The aircraft flew several sorties after the servicing before the rags, tie-downs and the aerosol can
were once again roaming around the baggage
area. The cardboard box was discarded after it
became damp from contact with a wet rag.
In the Warrior, the baggage compartment is
open to the space under the rear seats, a space
that is not easily visible and is not usually checked during a preflight inspection. You guessed it.
The aerosol can headed this way - and also contained in this area are the exposed elevator
control cables.
The can hovered inoffensively for several flights,
in the area of these cables.
Our pilot was due for some practice in the circuit
area and decided to combine his continuation
training with a pleasure flight for three friends.
His preflight was thorough but did not include
the area under the rear seat. He assisted his
passengers and carefully briefed them on the
coming flight.
·
Start-up and taxi were normal. After the run-up
and a final check of his passengers, he completed
the pretakeoff 'vital actions' and lined up.
The ALA was of adequate length but not such
that a pilot could ignore the far end when carrying out touch-and-go's. Takeoff was smooth and
on downwind the lady passenger in the front seat
seemed to be relaxing and enjoying the
experience.
The can was still under t he seat but due to the
vibration of the takeoff was edging its way along
the elevator control cable towards the pulley. On
downwind, the can settled into a niche between
the cable and the pulley.
The circuit was fairly tidy and the pilot concentrated on the final approach. He was keen to
demonstrate a smooth touchdown. The
passengers were enjoying the flight and an air of
expectation engulfed all four persons on board as
they looked down final at the runway threshold.
The can was still resting in its niche.
Threshold speed was spot-on as the pilot closed
the throttle and gently raised the nose to the
landing attitude. He was unconsciously holding
his breath when the wheels brushed the grass
surface. The pilot chuckled to himself and
momentarily bathed in the admiration of his
passengers. As he did so, the nosewheel touched
down firmly and the aircraft shook mildly as it
ran along the slightly uneven surface. The can
nestled further into the crutch of the pulley.
Time was now pressing. The pilot opened the
throttle to full power, lowered the flap lever to
retract the flaps and restored the trim to the
takeoff position. At about 60 knots he started to
pull back on the control column.
There was no response from the aircraft, no
change in attitude and no liftoff. The can was
now firmly wedged between the cable and the
pulley and prevented either from moving.
The pilot then wound back the trim; still no liftoff. At 70 knots with firm back-pressure and still
no liftoff, the pilot decided to abort the takeoff.
There was some 150 metres of runway remaining.
He shut down the engine and applied the brakes.
The Warrior overran t he runway and was headed
towards a 2 metre high earth levee. The pilot
tried to cushion t he impact by raising the nose.
Surprisingly, full-up elevator travel was now
available. The can, having been squeezed by the
pulley, had decided to move back towards the
baggage area. The aircraft was badly damaged
by the impact and the front-seat passenger
received a cut to her forehead from the visor. All
four POB exited the aircraft safely. There was no
fire.
Now let's look at the sequence of events with the
clock ticking. The touchdown occurred well
before the half-way point of an 850 metre runway. On touchdown the pilot:
• applied full throttle;
tick . . . t ick . .. tick .
• retracted the flaps; and
tick . .. tick ..
• restored the trim to t he takeoff
position.
tick . . tick ..
At 60 knots he applied back
pressure . . .
tick . .. tick . . .
and there was no response.
tick .. . tick . .. tick .. .
He applied further nose-up trim. tick ... tick . .. tick .. .
At 70 knots .. . and no takeoff,
he decided to shut down t he
engine.
tick . . . tick . . . tick .
There was now only 150 metres left to run.
During the groundroll the average speed of t he
aircraft was in the order of 60 knots. That is, it
travelled about 30 metres every second. From
touchdown, say one-quarter of t he way down the
runway to a planned liftoff, say three-quarters of
the way down, the pilot had some 14 seconds to
reconfigure the aircraft, make a control input,
assess t he response, make a decision based on
that response and takeoff or abort as appropriate.
In some aircraft the flaps can be raised instantly
whereas in others it takes several seconds. In
some aircraft the power is available instantly
whereas in others it takes some time to obtain
full power. In some aircraft the trim can be reset
quickly or doesn't have to be reset, whereas in
others, it can be critical and time consuming. In
some aircraft you may even have to change
hands to complete these actions.
Our pilot made the correct decision - the only
decision under the circumstances. But to avoid
the overrun, it should have been made earlief. If
he had decided to abort as soon as he felt t he
restriction in the control circuit, perhaps he could
have stopped within the remaining runway
distance.
For the benefit of all of u s, let us consider how
such a decision could have been pre-empted.
Aviation Safety Digest 131 I 17
�Knowing that we intend to touch and go, we
could mentally rehearse the actions that are
necessary for our particular type of aircraft.
These are probably familiar but note that they
vary from type to type. Also consider the
sequence in which they are done. Logically, the
power levers should be advanced first so that the
engine is accelerating while flaps and trims are
being set. Carburettor heat should be set to cold.
Flaps and t rims s hould be set as laid down in the
flight manual, if there is a procedure in the flight
manual for a touch-and-go. (Watch out for the
undercarriage selector when retracting the flaps.)
Bear in mind that failing to retract the flaps will
affect acceleration. It will also affect climb angle
and rate but it may well be better to do these
actions in the air rather than hesitate on the
ground. Some aircraft such as the Cl50 won't
perform very well unless flap is at least partly
retracted.
Failing to retrim will result in a nose-up pitching
moment. That is, the nose will want to rise due
to the application of power and the increasing
airspeed. This trim change could also be affected
by flap position or movement but in most cases,
not significantly. The out-of-trim forces can be
held without difficulty for the short period of
time that is required to retrim the aircraft.
However, ask your CFI to demonstrate these
effects in your aircraft type, at a safe altitude, so
that you can experience its behaviour.
Follow the procedure as described in the par·
· ticular flight manual, if there is one for a touchand·go, but if there is any doubt or confusion or
hesitation apply full power and fly away when
you have flying speed. Keep t he nosewheel off
the ground if you can and lift off normally. Then
you can retract the flaps slowly or in stages and
retrim the aeroplane as you go.
So now we have a predetermined series of actions
for a touch-and-go which can be rehearsed. What
else can be done to improve the margin of safety?
First, reduce the Landing Distance Required
(LDR) and the Takeoff Distance Required
(TODR) as these determine how much runway
will be consumed during the touch-and-go. LDR
is determined by t hreshold speed which is deter·
mined by All-Up-Weight (AUW) and factored for
gusty conditions. TODR is determined by AUW.
Both are affected by Wind Velocity (W/V), run·
way slope and surface and density altitude. So a
touch-and-go is sa~est at minimum AUW, into
wind, on a level, dry, smooth, long, ·runway at
low density altitudes. Select a runway of suffi·
dent length - as a rule-of-thumb, plan on using
a groundroll at least equal to your normal TODR
- and use this as the minimum runway length
for a touch-and-go in your aircraft.
Next, nominate a 'decision point' at which, if you
are not airborne, you will abort. This point is
selected on the basis of your ability to stop in
the remaining runway distance.
Spend the least possible time in the transition
from landing to takeoff, having achieved t he
normal threshold speed. Excess speed is not
acceptable on a touch-and-go.
Now we have selected the optimum conditions
for the manoeuvre, what about the unexpected,
the emergency? This is largely up to the individual pilot. There are an infinite number of
emergency scenarios. We should consider the
most probable and the most critical. For day
VFR flight, it would b e relevant to mentally
rehearse the following:
• engine failure, particularly during takeoff, goaround or touch-and-go situations
• control failure during takeoff
• flap extension failure
.
.
• undercarriage extension or retraction failure
• pilot seat failure or unlocking .
.
• door opening in flight, particularly durmg
takeoff
• navigational, medical and weather emergencies.
Our pilot, then, could have reduced the AUW by
leaving the passengers behind. (It would be
better not to carry pax on a 'demanding' training
sortie anyway. ) He was probably aware of the
procedures for a touch-and-go for his aircraft. He
could have rehearsed these and he may well have
done. Most importantly, he could have mentally
rehearsed the situation where he discovered
locked or restricted controls during takeoff.
The reaction must be immediate. Any control
problems while still on the ground - ABORT
ABORT ABORT - immediately.
Postscript
This pilot and his passengers were both lucky
and unlucky. The pilot made only one mistake
and that was to waste time by having a second
go at retrimming and lifting off instead of aborting immediately. If the aircraft had lifted off and
the pilot had found t he controls locked in a rear·
ward position the results would have been
disastrous. This could well have happened in this
case as t he controls had been fouled by the
aerosol can under the rear seat and they could
have jammed in any position 0
,..
It~
the thing you d~n't check
that will kill you
18 I Aviation Safety Digest 131
Y'all come back
now, y'hear?
on finals with good airbrakes is 10-15 degrees.
By avoiding a steep approach, you should be able
to easily see a glider on finals, silhouetted
against the sky. You are required to give way to
it.
Circuits may be in either direction - if over·
shooting keep straight and do not turn over the
airstrip in u se. It is easy to see if a glider is
about to be launched - instead of being parked
with a wingtip on the ground, the wings will be
held level. Sometimes a large signal bat will be
waved towards the winch driver.
HE FOLLOWING ARTICLE was prepared
by Noel Matthews, Flying Operations
Section, SA/NT Region of DofA. Noel is an
active glider pilot. He presents some very
valuable tips for power pilots who intend visiting
a glider field.
1. What to look for:
There are many small gliding clubs operating
near country towns; often theirs is the only nearby airstrip and being friendly, they are only too
willing to give permission for a visiting power
pilot to use their airfield. In fact regular 'power'
traffic can be a good reason to get the local
Council to assist in maintaining the airstrips.
Now this will immediately give rise to another
hazard: most Council grader-drivers automatically keep their blades at an angle suitable
for draining water off roads. So your gliding
strip, which is not very wide anyway, will prob·
ably have a fair camber. If you fly a taildragger
- watch out.
Many gliding clubs operate with winch launches
and what looks like a nicely gravelled airstrip is
probably really a winch 'road ' over which the
gliders take off. It is not normally used for landings. The landing areas are in fact usually
adjacent to the takeoff points. When the gliding
club is active these will be marked by a group of
parked cars or perhaps a mobile control van.
2. Arrival:
The VFG states that an arriving aircraft should
not overfly a (winch) gliding site below 1500 feet
agl. In fact it is safer not to overfly t he airstrip
in use at all. In strong winds (or with a long
strip) it is possible for a winch cable (breaking
strain 500 kg force) to go to 3000 feet or more.
Enough said!
Having arrived at the site with a brief radio call
on 122.7 MHz (there may not be a radio in u se)
complete a circuit to check the windsock, then
make a shallow to normal but not too long,
approach. The u sual approach angle of a glider
Be careful of landing while a winch launch is in
progress. If t he launching cable breaks the glider
will execute a very quick abbreviated circuit and
will aim to land anywhere he can, preferably on
the airfield. Gliders can safely execute a 180
degree t urn and land back in the event of a cable
break. The danger can come from the broken
cable which if attached to a drogue parachute,
will drift downwind, sometimes for a considerable
distance. (I've seen them finish up downwind of
the strip end.) If there is a crosswind obviou sly
that's t he way the drogue will fall.
Having landed, be careful when taxiing. If you
can ~ee a winch at the upwind end of the airfield,
assume that there are cables laid. Do not taxi
along the cables - if you need to cross them, do
so at right angles and without delay and only if
you can see that they are flat on the ground. If
one has broken it is possible for coils to be some
inches above t he ground (especially if high-tensile
wire is used, which is common). It is possible for
wire t o be picked up by a propeller - the next
one won't be the first.
Look for guidance to park somewhere out of the
way (not under the approach path).
3. Departure:
Before taxiing watch a few launches to see how
t he system operates and to see where the gliders,
cables and the winch are heading. Arrange for
some form of 'all clear' signal to be given to you
before takeoff ... and you will be wefoome
back 0
Aviation Safety Digest 131 I 19
�[ NUT
Nikon
iu CASE J
AVIATION PHOTOGRAPHIC COMPETITION
REPORT ON an accident involving a Bell
47 stated:
The Digest is pleased to announce its second
photographic competition for aviation enthusiasts.
While flying at a low forward speed approximately
15 feet above the trees, the helicopter suddenly yawed
to the right. As the pilot was unable to correct the
yaw he attempted to manoeuvre the helicopter ~o a
clear area. The helicopter impacted the ground m a
level attitude, moving rearwards and rotating.
Category 1 - A Nikon
F-301 Program/ MotorDrive Camera with a
SOmm fl.8 lens.
Retail Value:
AS 1.035.00. This is a
state-of-the-art
automatic camera
with manual reversion
and integral film-wind.
The competition is designed to encourage an
awareness of safety related matters in the field of
civil aviation. It is also to promote a high standard
of photography of aviation subjects w hich may be
used to maintain the quality of presentation and
reader participation in the Aviation Safety Digest.
The competition is sponsored by Maxwell Optical
Industries Pty Ltd, the Australian distributors of
Nikon photographic equipment.
During the impact the Bell's main rotor hit a
dead tree: the rotor and mast were torn forward
and across the canopy bubble. The mast smashed
the bubble and tore the pilot's firmly fastened
helmet from his head.
Category 2 - A Nikon
FG-20 Auto/ M anual
Camera with a SO mm
fl.8 lens.
Retail Value: A$725.00.
The FG-20 is a 35mm
single-lens reflex with
aperture priority
exposure and manual
over-ride.
Based on the damage which the helmet sustained, it is likely that if the pilot hadn't been wearing it, he may well have suffered severe head
injuries or even been killed.
'Hot, heavy and uncomfortable' are some of the
adjectives used to describe safety helmets. At
least one pilot describes them as 'life-savers' 0
1· ••
Three categories will be judged :
Category 1 - For the best print or transpcrrency
on the general subject of Australian civil aviation
or Australian civil aircraft. The judges' emphasis
in this field will be photo graphic and artistic quality.
Category 2 - For the best picture illustrating a
safety aspect or an unsafe aspect o f Austral.ian
civil aviation. A clue in this field is that the primary
contributory factor in aviation accidents is the
'human factor'. The judges' emphasis will b e the
'message' and how well the photographic design
conveys that message.
\
Three prizes will be awarded as follows:
R~~~\
....
~t
,.
j\\)\\0·'
.. . ,.-
Category 3 - There will be a specific prize for the
best monochrome print. Black-and- white
photographs in particular are a valuable
contribution to the Digest. The judges will lo ok
for photographic skill and artistic compo sition
which best exploits the unique quality of the
black-and-white photograph.
Category 3 - A Nikon
L35 AWAF Auto-Focus
camera with built-in
flash.
Retail Value: AS595.
This is the rugged,
w aterproof, fully automatic Nikon with builtin motor-drive.
Entries close with the last mail on Friday,
26 June 1987 and should b e addressed to:
Photographic Competition
Aviation Safety Digest
GPOBox 367
CANBERRA A CT 2601
CONDITIONS OF ENTRY:
Any number of entries may be submitted in any or oil categories.
Prints should be g loss finished and preferably be about 13 cm x 18cm all hough
a ny format Is acceptable. Transparencies must be mounted.
Entries must be accompanied by the entry form enclosed In the centre seclion
o f the Digest or available from the Sotety Promotion Liaison Olticer in any.
Departmental Regional Oftice. Pilot Briefing Room and m ost Photographic stores.
Entries should be clearly marked - PHOTOGRAPHIC MATERIAL -
DO NOT BEND.
The competition is open to oil Australian citizens with the exception of stall from
the Safety Promotion Section o t the Deportment of Aviation and employees ot
Maxwell Optical Industr ies, and the ir Immediate !amities.
The Digest reserves th e right lo publish once. any entry rece ived in this competition.
Any tur ther pub lication will b e with the express permission of the photographer
concerned. Winning entries becom e the property of the Deportment o t Avmhon.
The Digest will ta ke every co re with entr ies but canno.t a ccept responsibility
foiloss or damage. Selected enlries w!li b e te mporarily retained by the Digest
tor a display to tour m a jor aviation venues. It entries ore to be returned. p l ease
include return postage.
The judging panel will consist ot:
the editor o ! the Digest;
..
.
.
a p hotographic specia list !rom outside the Deportment. fpm1hor wi th aviation
subjects. and
.
.
a representative from the Bureau o f Air Solely lnveshgahon.
20 I Aviation Safety Digest 131
The judges decision will be final.
�A glaring
deficiency . .
or shades of
darkness?
The lenses
•
Doctor Adrian Zentner is an aviation medicine specialist
in the central office of DofA. He has recently returned
from a period of study at the Institute of Aviation
Medicine at Farnborough, UK. In this article he offers
advice for pilots on the selection of sunglasses.
f
.
LARE IS ONE of the most common problems encountered by pilots and yet it has
received scant attention in aviation safety
publications. Impairment of vision by glare and
dazzle has been reported as the primary cause of
disorientation and loss of control in a number of
aircraft accidents. The wearing of suitable
sunglasses for glare protection may help prevent
such occurrences. Ho wever some types of
sunglasses have themselves been implicated in
aircraft accidents.
Suitable glare protection obviously improves the
safety of visual flight. The problem is to find the
right sunglasses for the aviation environment.
There are two primary factors to be considered
when choosing sunglasses - the frame and the
lenses.
L
~
Sunglass lenses should protect the eyes from
glare without adversely affecting the visual cues
necessary for safe flight. Accordingly, lenses
should not be too dark - ideally they should
absorb about 15 per cent of the ambient light.
The 'tint' should be 'neutral density' (ND) that is a greyish tint that does not change the
colour of objects as perceived by the pilot and
does not adversely affect r ed signal detection and
recognition (warning lights and cockpit displays).
The optimum lens for pilots is then 'ND15'.
To ensure that sunglasses provide adequate protection from solar radiation that could damage
your eyes, only those sunglasses that conform to
Australian Standard AS1067 -1 983 should be
worn. For aviation use, those sunglasses marked
'specific purpose s unglasses' are recommended,
provided their frames are appropriate. The lenses
of these sunglasses have been specifically designed for use in conditions in which glare is very
intense, such as flight above cloud, where at
higher altitudes, atmospheric absorption of
ultraviolet radiation is reduced.
Sunglasses that conform to AS1067-1983 also
meet acceptable standards for lens quality, frame
strength and lens retention, for aeronautical use.
Polarised sunglasses should not be used while
flying: The polarising filter interacts with the
cockpit transparencies to produce a distorted and
degraded visual field that could be a significant
hazard.
For those who wear spectacles
Those pilots who already wear prescription spectacles for flying can choose from a number of
options for glare protection. Prescription
sunglasses with ND15 lenses can be obtained or
ND15 clip-on or flip-on sunglasses may be worn
over prescription spectacles.
Pilots who require correction of t heir near vision
only and who wear 'lookovers' are advised t o
obtain bifocals with a 'piano' - that is uncorrected upper segment. Clip-ons or flip-ons can
then be worn with them.
Another option is the graduated tint. Glasses can
be made in such a way that the lower portion of
the lens is only lightly tinted or not tinted at all.
This provides glare protection for distant vision
outside the aircraft and near vision inside the
cockpit is not impeded. The use of a single tinted
segment in bifocal glasses should be avoided as
the visual effect of the 'false horizon' where the
two segments meet, can be distracting and
disturbing.
A further solution to the problem of glare which
may seem ideal for wearers of prescription
glasses, is the photochromic lens. These lenses
react to the light level and go darker in bright
conditions and bleach when the light intensity
fails. Unfortunately these lenses have some
disadvantages that make them unsuitable for
flying.
First - their response times are r elatively slow.
Photochromic lenses take about five minutes to
increase their density t o the level of a sunglass
but more importantly, the bleaching time from
maxi~um to minimum density can be as long as
30 minutes although there is a rapid lightening
of the lens in t he first five minutes. This can be
too long in the aviation environment when there
~s a sudden var iation in light level due to flying
m and out or under cloud or when you wish to
scan from outside the aircraft to inside the
cockpit.
Second - even when they are fully bleached,
photochromic lenses still absorb slightly more
li~h.t than untinted lenses. Since flying is so
cr1ticallY: dependent on vision at low light levels
and at rught, even a small decrease in the
amount of light reaching t he eye can be
significant.
Conclusion
As much as 80 per cent of the information
required by a pilot is acquired by sight. Pilots
who wear suitable sunglasses can protect their
eyes from damaging solar radiation, glare, and
still ensure that vital visual information is not
prejudiced.
·
To be safe - choose the correct sunglasses and
have them properly fitted O
The frame
Any spectacle frame reduces the pilot's field of
view - that is the area of the uninterrupted
visual field. So narrow, slender frames are best.
A void frames with deep side-arms as they interfere with the peripheral view and this view is
vital to pilots for both collision avoidance and
judgment of attitude, motion, distance and
height above the ground.
Choose a comfortable frame and have the spectacles correctly fitted to your head. We all differ
slightly and ill-fitting 'sunnies' can be a real
'pain' after a few hours.
22 I Aviation Safety Digest 131
Aviation Safety Digest 131 I 23
�
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•
Knowledge + Preparation + Recency
.D
D
�Contents
3 Editorial
3 The policy on pilot immunity
4 The pilot -
cause or victim of the accident?
A pilot-in-command must take command.
6
Cockpit communication breakdown
A missed approach was initiated as a DC-9 passed
through the centre of a microburst. The Captain then
elected to land, incorrect ly perceiving that the aircraft
would not climb, and the DC-9 struck the runway with
the gear partial ly extended.
12 Assessing the conditions
An Aztec was damaged during a go-around from an
unexpected tailwind on an island st rip.
13 Ground-run fiasco
The owner of an Amer Air had swung the propeller in
order to give the engine a ground-run. The tie-down
ropes snapped, the aircraft struck the tail of a Cessna
Aerobat and then ran into a Cessna 182 before the pilot
was able to get into the coc kpit and shut down the
engine.
14
A slung load became unstable and struck the tail boom
of a Bel l 206B Jetranger during a ship to shore run. The
investigation revealed a number of interesting factors.
16 Protective clothing
When a large Cormorant flew into the cockpit of a
PA25, the pilot's life was saved by a helmet which he
had acquired 10 days earlier.
18 Compressor washing
Unless otherwise noted, articles in this publication are based
on Australian accidents, incidents or statistics.
Distributees who experience delivery problems or who wish to
notify a change of address should contact:
The Publications Distribution Officer
Department of Aviation
P.O. Box 18390, Melbourne, Vic. 3001, AUSTRALIA
Telephone (03) 662 2455
Aviation Safety Digest is a/so available on subscription from
the Australian Government Publishing Service. There is a
subscription form in this issue. Inquiries and notifications of
change of address should be directed to:
human factor' and articles in the aeronautical press
are generating discussion, a rgument and ideas. This is
a positive effort which will benefit all of us .
To further promote the increasing awa reness of the
roles and limitations of the pilot-in-the-loop, a special
issue of the Digest, to be published next year, wil l
focus on 'The human factor' . Your contr ibu tions would
be we lcome.
The photog raphic compet ition run by the Digest
during 1985 was such a success that many have asked
for a re-run. I am happy to an nounce the competition is
to be held aga in early in 1987 along similar lines to the
previous one.
I hope that with your assistance, the Digest can
cont inue to play an importan t role in accident
prevention.
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.G. T. 2601, AUSTRALIA
Telephone (062) 95 4411. Telex AA62013
Subscriptions may also be lodged at Commonwealth
Government Bookshops in the capital cities.
The policy on pi lot immunity
Reader contributions and correspondence on articles should
be addressed to:
How to make the game tough
The Editor, Aviation Safet y Digest
Department of A viation
P.O. Box 367, Canberra City, A.G. T. 2601, AUSTRALIA
© Commonwealth of Australia 1986
ISSN 0045-1207
R851979(1) Cat. no. 86 0310 3
Printed by Ambassador Press Pty Ltd
51 Good Street, Granville, N.S. W. 2142, AUSTRALIA
Editor
Editorial assistant
Graphic design
A pilot w ithout an instrumen t rating and under the
influence of alcohol was killed when he attempted a
night landing at Cooma.
21
There has been much debate recently concern ing
situations whe re pilots call for assistance . It has even
been suggested that pilots should not seek assistance
in case they risk some fo rm of d iscip linary action. The
concern of the GA community is understandable and at
a joint AOPA/D.ofA. Pilot Safety Awareness Seminar at
Coif's Harbou r recently, it was evident that the subject
was prom inent in pilots' minds. As a con sequence, I
have asked the First Ass istant Secretary, Flight
Standards Division of the Department of Aviation, Mr
Jerry O'Day, to respond formally on this important
matter. Mr O'Day's statement fo llows this editorial.
It is encou raging to see the initiatives and responses
taken by all sectors of the aviation commu nity towards
improved safety standards in General Aviation . The
Pilot Awareness Seminars, the video 'Pilot - the
Human factors in wheels-up landings
16 Slung-load instability
20
Aviation Safety Digest is prepared by the Department of
Aviation and is published by the Australian Government
Publishing Service. It is distributed to Australian licence
holders (except student pilots), registered aircraft owners and
certain other persons and organisations having an operational
interest in safety within the Australian civil aviation
environment.
Microbursts and Australian aviation
The phenomenon of the microburst was perceived by
the investigator-in-charge of an F27 accident at
Bathurst in 1974. It was subsequently identified and
researched by Professor Fujita of the University of
Chicago. In December 1982, glider pilots in S.A.
observed and photographed a dry microburst.
9
Editorial .
David Robson
Linda Thomson
Lesley Gordon
Tony Kelly
Loose aerosol can causes fire
\
The nose locker of a Beech 58, which landed with a
cab in fire, was found to contai n two 1 litre cans of oil
and three aerosol cans, one of wh ich contained paint.
22
Dangerous fumes (Reader contribution)
23
Animal acts
In a representat ive 2V2 -year period, there were 57
reported occurrences of animals obstructing landing
areas in Australia.
COVERS
The human factor
The sing le most important factor in aviat ion safety
is the human one. To highligh t its significance we
have adopted a logo which w ill be used to link all
items within this category. Logo design by David
Robson.
2 I Aviation Safety Digest 130
Front. The cockpit enviro nment is subjected to many
stresses - as are the humans inside. Our cover design
rep resent s the disruption caused by physical, physiological
and psycho log ical st resses - stresses that can cause 'the
human factor' to perform at less than optimum levels.
Back. Safety starts with the pilot. Thi s poster identifies some
of the important stepping stones whic h lead to safe flight.
I mentioned in the editoria l for the July issue of the Digest
that I would clar ify the situation regarding immunity for
pilots in c ircumstances where they call for assistance.
I am particularly concerned about suggestions that
pilots shou ld not seek assistance, because to do so could
result in punitive action.
This is simply not true. The standing policy is that pilots
a re granted immunity from discip linary action in
situations where, because of navigational or other
diff iculties, they seek assistance from Air Traffic Services.
This immunity applies rega rdless of whether or not the
outcome involves entry into controlled airspace without a
clea rance.
You have my assurance that punitive measures will not
follow an event of th is nature provided those involved
acted in good faith. In other words, provided they did not
flagrantly ignore the ru les or ac t withou t regard for the
safety of others and that they were properly prepared tor
the flight.
There will be occasions when, despite proper planning
and correct procedures, a pilot wil l get caug ht out. It may
be that a con tributory factor such as poor navigation , lack
of fam ilia rity with the airc raft o r area, or even deficient
flying techn iques is discovered. In such circumstances the
Depa rtment may propose remedial training or a flight
check with the pilot's own CFI or with an Examiner. This
action is not punitive. It is designed to assist the pilot in
particular and the aviation commun ity in general to
maintain the required degree of operational safety. The
Department would be rem iss if it did not take such action.
It is not a slur on the pilot concerned. It is a constructive
procedure, aimed at resto ring a safe level of competence
and it is in this spirit that any such training o r check will
be conducted.
The policy exists to encou rage pilots in serious
difficu lties to use whatever assistance is necessary to
ensure safe flight and to do so without hesitation. It is
important that such calls for assistance are made at the
ea rliest possible time while adequate fuel and daylight
remain, so that other traffic can be d iverted to assist and
so that adequate terrain clearance and weathe r
avoidance can be ar ranged.
I urge you to take advantage of the Air Traffic
Services without a second thought. Air Traffic Controllers
and Flight Service Officers are there to assist you to
complete your fligh t safely. They are keen to help.
However, as was highlighted at the Coif 's Harbou r
Seminar, there can be a psychological barrier that
sometimes exists wh ich deters private pilots from ca lling
for help or even from submitt ing a flight plan, fo r fear of
making a mis take and feeling a fool or being rebuked by a
Departmental officer. We must overcome th is barrier . The
way to do so is for pilots and Fligh t Service Office rs to
d iscuss thei r problems, ideas and procedu res with each
other on a regular and informal basis.
I am assured by my colleagues in Ai rways Division that
approaches of this kind wil l be welcomed .
We all have the same aim : to enjoy a high degree of
safety in our flying . To achieve this we must work
together. If you need help, ca ll for it.
I hope these comments will clear up any
misconceptions that may have existed rega rding the
'immunity' policy.
Oerry O'Day)
First Assista nt Secreta ry
Flight Standards Division
Aviation Safety Digest 130 I 3
�r
~
mu
The pilot - cause or victim of
the accident?
Professionalism in aviation requires that the pilot
recognise and allow for his or her own capabili ties and
limitations and those of the aircraft as well a s the
influences of the environment. This professional
attitude is a combination of knowledge , anticipation,
skill and self-discipline . It begins in the student pilot as
a combination of motivation and talent. It is developed
by observation , by example, by training and by
expe rience .
The pilot with thi s attitude becomes the fail-safe
pilot. However , two influences remain which can
threaten the predictable and safe conduct of his flying :
• the unexpected occurrence such as mechanical failure
or extreme weather ; and
• the relaxation of self-discipline and lowering of
standards by factors such as lack of sleep, overindulge nce or the subtle influence of o ther human s.
Unexpected occurren ces can be countered , or the ir
effect minimised , by mental and phys ical rehearsal of
emergen cy situatio ns . (Simulators can play a significant
part in these reh earsals.)
H owever , the relaxation of self-discipline and
lowering of standards is an insidiou s p rocess . The pilo t
may not even realise the effect on his or he r skill or
judgment though he or she will q u ite likely feel one
sym ptom - stress - cau sed by a co nflict of interests.
*
*
*
Stress one
The C herokee was to be the second of t hree a ircra ft in
an island-ho pping shuttle flight. After loading, it was
discovered that the a ircraft had a flat batter y . With
some delay a batter y-cart was bor rowed and the aircraft
was started using this external power source. Soon after
takeoff, the fi rst a ircraft experienced radio problems
and turned back to the mainland. Our pilot was now
leadin g the shuttle (stress beginning) .
At Prince of Wales Isla nd, a group of Isla nders was
awaiting the arrival of the three aircraft to take them to
Mer Isla nd. Included in the group was a coffin
co nt aining the bod y. of a recently decea sed female
Islander whose funeral was to ta ke place on that island.
The gro up was originally to h ave been transported to
M er Island on the preceding W ednesday but had been
frustrated in their endeavours by th e un serviceability of
the scheduled aircraft. This d elay h ad cau sed
considerable annoyance to the fun eral p arty and it had
meant being fer r ied p ar t of the way in a sm all boat not a h appy congregation.
N ot sur prisingly, the late-arri ving C h erokee was
greeted with less-than-o pen arm s. The pilot was
criticised for th e delay and hara ssed by a ll and sundry.
Unco ntrolled efforts then began to pile as m a ny of the
. group as possible, plus the coffin, in to the C herokee .
4 I Avia tion Safety Digest 130
touched down some 10 metres in from the threshold
and bounced. The next touchdown was about 140
metres fa rther in. Full braking was applied but it
becam e o bvio us the aircraft could not be stopped in the
remaini ng ru n way distance. The pilot tried to ground
loop but the aircraft slid sideways off the end of the
str ip, down a 40 degree embankment and came to rest
against the trees some 8 metres below.
T here were no inj uries.
These efforts were stopp ed by the pilot who informed
the agents that , bei ng in com man d of the aircraft, sh e
would load it as she co nsidered fi t and proper. T h is
attitude received a cool reception (more stress).
The two rear seats were removed and the coffin was
lo aded and secured. Then th ere was an uncon trolled
rush to boa rd the aircraft. O nce a gain, the pilo t had to
exert her authority and inform the group that she
would select the passengers to accom pany the coffi n.
She therefore picked three child ren and three of the
sm allest adults a nd loaded them into the aircraft.
However, these pro blem s had caused further delays
and valuable tim e was passing (more stress) .
After entering the aircraft and attem pting to start the
engine , the pilot d iscovered to h er d ismay that, once
again , the batter y was unable to perform its task . T he
passengers were d isem ba rked and var ious attempts
made to star t the engine . T hese fu rther delays caused
more aggravation and d iscontent to the funeral party
(mor e stress).
The engine was even tually started and the p ilot h ad
to rema in in the aircraft while the passengers
r e-em barked . This caused the pilot further an xiety
because of th e m anner in which a ll a nd sun dry were
milling around under no d irect con trol by the agents
and there was a consequent r isk of someon e walking
into the spinning propeller. T he pilot was also star ting
to feel the effect of the m idday heat and she h ad no t
had an y food or d r ink since the night before.
Eventually the flight departed for Mer Island. On the
fligh t across th e pilot had several things on her m ind:
• There was sufficient fuel fo r the flight to M er Island
but sh e would have to return via H o rn Island for
fuel - this would fu rther delay the rema ining
Isla nders and hence cause more antagonism .
• She was u ndecided wheth er she should keep the
en gine running while u nloading at Mer Island o r
shut do wn and r isk a no -star t. If the engine was kept
running, the pilot would be faced with the problem
of an excited party of Islanders unload ing the
a ircra ft, n ot under the control of an y responsible
person and with the consequent risk of injur ies
th rough a prop-strike.
• The a ircraft was required back at C airns that night
to carry out a chart er on the following day , which
she was sched uled to fl y .
• She was alread y tired , frustrated by the delays and
feeling the psychological effects of th e aggressive
a ttitude of the passengers.
U nder these conditions the pilot set u p the aircraft
for a final ap proach to land on Mer Island.
Dur ing the approach she fou nd the aircraft's fligh t
path d escending below the level of the runway (the
threshold was elevated above the surrounding terrain).
Power was a pp lied and while correcting the fligh t path,
it also led to an excessive threshold speed . T he aircraft
So we have an apparently misjudged and overco rrected lan ding approach. Under the circumstances,
the pilot dese r ves an award for diplomacy and for
resolve in controlling t he events as well as she did .
H owever, it would have been valuable to 'switch off' all
extraneo us thoughts when the 'downwind' checks were
carried out. In th is way the pilot could have devoted
her undivided attention to the final approach - the
m ost cr itical phase of flight.
W ith hindsight and with experience, it is possible to
men tally con d ition ourselves in this way. You may have
h eard of ' load-shedding', which simply means putting
aside non -relevant o r lower-priority thoughts and
concent ra ting on the task at hand. It is a form of
mental self-discipline.
*
*
Stress two
Three passengers were to be flown from a rural
property to Geraldton and return . At the last minute,
the aircraft owner was not available and the pilot was
asked to cond uct the fl ight. She agreed and arranged to
meet the passengers at the farm . She inspected the
'strip' (which was the road into the farm) but was
concerned about the len gth and the width. The grass
had recently been cut and baled and the bales were
alongside the strip (stress beginning).
T o ease her concern, the owner of the aircraft took
off and completed a circuit to demonstrate the
acceptability of the str ip. Our pilot agreed to do the
flight, bu t wit h som e reservations.
The fl ight to Geraldton was uneventful. But after
la nd ing , the p ilot felt un happy about the weather and
the strip sh e was to ret urn to and tried to make
arrangements to stay overnight in Geraldton .
Unfor tunately, one of the passengers had to return that
night. H er car was at the strip and she didn't want to
be la te h ome.
The fligh t back was also uneventful but the pilot had
many things on her mi nd:
• She was not happy a bout the fo r thcoming landing
and considered diverting to a nearby airfield which
was used regularly by the aero club and with which
she was fa m il iar and confiden t .
• The passengers ' cars were parked at the strip.
• There was no telephone at the airfield to make
alternative transport arrangements .
• Any delay caused by such a diversion was
unacceptable to at least one of t he passengers .
She elected to continue to the stri p but she ~as
hardly relaxed a bout it. On arrival, she carried out an
a irborne inspection . The windsock indicated a southerly
at 5-10 knots. She would land into the wind but was
concerned that the aircraft was heavy (half fuel plus
four pax) and that the available strip length was
marginal. Although the road that made up the strip was
marked with tyres, the gravel road extended beyond the
tyres fo r some distance at the approach end. She
decided to land on the road short of the marked
threshold to increase the landing run available (more
stress) .
The approach was normal, using full flaps. After
touchdown on the gravel road, the aircraft moved to the
left side and stayed there despite all efforts by the pilot
to control it. This was the final straw in her decision to
reject the strip. She dec ided to go around and divert to
the nearby airfield.
The pilot applied full power. Almost immed iately,
the aircraft turned sharply left and headed towards a
fence. To avoid impact, she pulled hard back on the
control column and the aircraft staggered into the air,
over the fence and touched down, left-wing first, in the
paddock beyond. The a ircraft swerved violently and the
nosewheel snapped off.
T here were no injuries.
(The cause of the pull to the left was a gully which
trapped the left wheel. The cause of the sudden turn
was the wheel hitting one of the tyres which marked the
threshold.)
Again the pilot was pressured into a situation where
an accident was almost inevitable.
The latter pilot had allowed the indecision to linger
to the point where she was highly stressed. If a t any
point the sequence had been interrupted - by staying
overnight, by diverting to the airfield or even by
decid ing to land at the strip and consequently preparing
herself and the aircraft to ensure the best chance of a
successful landing (i.e. minimum all-up-we ight , pract ice
approaches to explore the cond itions, men tal rehearsal
of short-field techn iques and finally trust in her· own
judgment and skill), then the stress would have been
contained so th at it could not interfere wit h flying the
aircraft.
*
*
Remember all these stress factors are additive but onl y
if they are allowed to be.
T hese pilots did not cause the accidents. But they did
allow themselves to become victi ms of their
circumstances . T he first pilot was rightly assertive but
allowed men tal distractions to affect her concentration
on the final approach . A landing can never be routine
to the extent th at your mind can be on other things.
The latter pilot was not assertive enough despite her
conti n uing concern abou t the landing.
A piloc-in -command must take command:
• of himself or herself (though ts as well as act ions);
• of the aircraft ; and
• of the passengers and crew •
Aviation Safe ty Digest 130 I 5
�Microbursts and Australian
aviation
Based on a paper /1repared and contributed by W.
f.
Grace and M.
f.
Fig. 3
Haney, Bureau of Meteorology, Adelaide, South Australia
Description of a downburst
As water from a kitchen tap spreads out horizontally
when it hits the bottom of the kitchen si nk , so a
downward draught of air in the middle levels of the
atmosphere will eventually become an outflow of
horizontal winds if and when it reaches the ground.
Such a downdraught is classified as a 'downburst' if
these horizontal winds exceed 35 knots. The a ir
spreading horizontall y is known as the outward burst.
Near the ground the outward burst often has a
violent lifting effect at the outer perimeter. Swirls of
dust and leaves, and even roll-type clouds may be
associated with the phenomenon. Frequently there is a
loud roaring noise, similar to that of a tornado. In the
worst cases, trees may be blown down and buildings
destroyed. H owever, a downburst not strong enough to
damage buildings may still present a significant danger
to ai rcraft operations.
An idealised downburst in otherwise still air will
produce a uniform, or radial outburst (Figure I). If this
down burst is moving horizontally, embedded in the
overall wind flow, then the area affected by the outward
burst will approximate an ellipse with the major
diameter , or path length, being aligned with the overall
wind flow (Figure 2). The lateral diameter is called the
path width and would typically be about half to onethird of the path length, although occasionally the
downdraught rotates as it descends causing the path
width to be greater than the path length . As awareness
of the phenome non has increased, the number of
observations have risen and surface damage patterns
may a lso be studied. A downburst is now classified as a
'microburst' or a 'macroburst' according to the
horizontal dimensions of the damaging winds.
Headwind
Fig. 1
'
I
I
I
I
I
Vertical cross-section
O u lflow
6 I Aviation Safety Diges t 130
J / 1\~"'-~
'--~=<::~\4 " ' -~~
~---.:5
----
~
..
/
I~
Ou I flow
/
/7J/;7~~ITIT/!1@1II/ITITIT)!l;//Im;;~1//II1//1
!.f'
11 1 krn ) - - - -
Plan view
A microburst situation: a heavy ;et airc raft depart ing in to a microburst experiences (1) improved performance (2)
decreasing headwind (3) a strong downdraught and then (4) a strong tailwind. Posit ion (5) could be reached p rior to
impact in a strong m icroburst. Since 1970 t he U.S. Nationa l Transpo rtati on Safety Board has identified 15 airline
accidents where windshear was a cause or contributing factor. In 12 of the cases the aircraft encountered a
downdraught or microburst.
situation and lead to an accident . An aircraft taking off
into a micr oburst could be in even greater danger than
in the land in g case.
Fig. 2
An Australian microburst and aircraft accident
Vertical cross-section
Microburst
The terminology of microbursts was introduced in 1976
by Professor T. Fujita of the University of Chicago. A
microburst is a downburst with horizontal dimensions
less than 4 km, while the dimensions of a macroburst
exceed 4 km. A typical microb urst would have
horizontal dimensions of 3 km, a lifetime of 10
minutes , and a horizontal wind differential or shear of
approximately 50 knots. The vertical depth of the
outflow is o rdin ar ily between 300 m and 1200 m, or
1000-4000 feet. Since 1964 nearly 500 people have
been killed throughout the world in accidents known to
have involved microbursts. If an idealised microburst
were centred over an aerodrom e while an aircraft was
making an approach to land , the pilot(s) would first
encounter a rapidly increasing headwind which could
raise the indicated airspeed substantially, encouraging
the pilot to make a large power reduction . With
reduced power, the a ircraft would then quickly enter
the huge downburst a t the centre of the microburst,
"
Tailwind
Plan view
before passing into a tailwind of the same magnitude as
the prev ious headwind (Figure 3). In these
circumstances a go-around m igh t not be successful,
particula rly if the downburst was encountered in heavy
rain at the min ima o f say an ILS approach. D epending
upon the p a rticula r circumstances, the performance of
the aircraft could prove unequal to the demands of the
A classic case involving this phenomenon occurred at
Hathurst , N ew So uth Wales , in Ma y 1974. An F27
engaged on a R egu lar Public Transport se rvice entered
the circuit area in generally line conditions, wi th the
su r face wind reported as 5 knots from the north-east.
Some rain wa s ev ident over the eastern sector of the
aerodrome associated wi th a nearby active cum ulus cell,
and a fter descendin g through 300 feet above terrain th e
a ircraft encountered heavy rain . A headwi nd
componen t of 30 knots rap~dly developed, the aircraft
drifted well off t he centreline, and with a wheel height
of 50 feet a go-aro und was in itiated. By this time the
F27 had left the headwind and entered an area of
rapidly in creasi ng tail wind. Coi ncident with the chan ge
in wind direction the aircraft was also probably affected
by a downdraught of at least 2 . 5 metres per second ,
and the F27 crashed 48 metres from the runway
centreline (see photograph) .
T he BAST Inspector (A ir Safety) in charge of the
accident investigation was the firs t person in the world
lo perceive th at this largely u nknown phenomenon
co uld be an acciden t cause, and it was later· that the
terms d ownburst and microburst became more widely
known. The unpredicted behavio ur of the a ir d uring
the go-aro und at Ba thurst h ad adversely affected the
climb performance of the a ircraft at a height too low to
effect recover y, and the acciden t report gives this as the
cause .
T he investigation report on th is accident aroused
considerable interest overseas, particularly in the
U n ited States where scient ific research into mi crobursts
was being initiated. Professo r Fuji ta of the Un ivers ity of
Chicago researched the phenomenon a t Stapleton
Internacional Airport in De nver, Colorado, in 1982 - 84,
using h igh reso lut ion Doppler radar a nd other
equ ipment, and for the first time the characterist ic
a ir now with in a microburst was determined . This was
known as the Jo int A irport Weather Studies (JAWS)
Aviation Safety Digest 130 I 7
�I
Cockpit communication
DI breakdown
project wh ich , besides expanding our knowledge of
m icrobursts, found that an average of 1. 4 m icrobursts
per day occurred in the study a rea.
Visual appearance of microbursts
Many m icrobu rsts observed during the JAWS program
were not associated with thunderstorm activity, and
were freq uentl y seen in what appeared LO be quite
harm less conditions . Many mi crobursts were associated
with light precipitation which evaporated before
reachin g the grou nd, a phenomenon known as 'virga'.
O thers were em bedded in heavy rain and had an
appearance closer to a pilot's traditional view of a
thun derstorm . Another visual characteristic was the
appearance of localised blowing dust at the surface as
the downburst reached the ground. In dry and dusty
environment s this character istic co uld provide valu able
clues to pilots a nd enable them to stay well clear of a
microburst. A rarer but more severe form of microburst
is associated with intense or well-developed convective
storm s. R esearch into the developme nt of m icrobursts
in th ese situations is continuing.
Causes of microbursts
Amongst the mechan isms which may cause or
contribute to th e forma tion of a microburst
downdraught the fo llo wing have been proposed by
research ers:
- cooling of a ir by the evaporation of falling rain
- coolin g from me lting snow or ha il
- frict ional drag from fallin g precipitation
- a highly localised alteration to the a ir pressure
gradien t with in a nd adjacent to the developing
microburst due to upper level wind effects
- deflection of a ir already in h orizontal motio n
adjacent to the developing sh aft of the microbu rst
into the shaft itself
In addition it is possible that if th e downdraught
rotates as it descends, then its overall dimen sions will
be reduced and the outflow of air o_n the ground will be
co nfined to a smaller area. Of the mechanism s wh ich
m ay in itiate a microburst probably the most common is
evaporative coolin g. Since microbursts may or m ay not
be associated with precipitation , they are term ed either
'wet ' or 'dry' microbursts .
and other data, meteorologists calculateC! that the
cloudbase was 10 500 feet, the speed o f the surface
outflow was 35 kno ts, a nd the downward velocity
achieved was 3000 feet per minu te. I t was also
estimated tha t the tim e taken from initial formation of
the downdra u ght at cloudbase, through the m icroburst
stage to decay require d 10-12 minutes.
At the present time theoret ical calculation s indicate
that the maximum speed wh ich could occur in the
surface outflow a ir is 49 knots. An aircraft fl ying
through a microb urst of this magnitude wo uld th erefore
experience a ho rizontal windshear of 98 knots.
C alculations also indicate that theorelically the
maximum a tla inable down burst velocity could be 3500
feet per minute. The maximum wind differential
observed in a sample of 70 microbursts from th e JAWS
project was 93 knots:
B!?ear terror .I
Observation of a dry microburst in
South Australia
In the late afte rnoon of 12 December 1982, m embers o f
the Murray Bridge Gliding Club observed and
photographed a hug<.; expanding ring of dust. T he
in itial core of the downdraught was du st-free and
estima ted to be 600- 700 m etres in diameter, with the
oute r rin g of dust estim ated to 200- 250 m etres or
650- 800 feet in both height and width. After a few
minutes the dust-free core h a d expanded to about 10
km in di amete r , while the outer rin g of du st became
higher, wider and more diffuse. The visual impression
to the glider pilots was that of a huge explosion. G lider
pilots fl ying in the area reported sink rates as high as
2000 feet per m in ute. No showers were reported in the
a rea alth ough some streaks of virga a re eviden t beneath
the mammatus cloud in the photograph.
Using Adelaide Airport upper a ir temperature
soundings, the surface temperature at Murray Bridge
8 I Aviation Safety Digest 130
References
W. J . G race & M . J . H aney, 'T he microburst and Australian
aviation ', 1986.
J. M cCarthy & J. W . Wilson, ' T he microburst as a hazard to
aviation ', N atio nal Centre for Atmospheric Research ,
Boulder, Colorado, 1984.
Accident Investigation R eport 76-2, Australian Department of
Transport , 1976 •
A DC-9 d esignated Flight 183, operated by a n
American co mpan y, took o ff in the mid-afternoon with
5 1 passe ngers, bound for the Detroit Metropolitan
Ai rport. The weather forecast was typical for summe r ,
including a prediction for 'quite a few scattered
a fternoon and evening thunderstorms, possibly severe ' .
En route weather verified this forecast. About 90 miles
from Detroit the crew detected scattered thunderstorms,
most of them west of the a irport.
T uning in the Automatic Terminal Information
Service (ATIS), they received information 'Charlie',
giving scattered cloud at 4500 feet , visibility 7 miles,
su rface wind 280/ 13; Instrument Landing System (ILS)
approaches were being used for ru nways 21L and 2 1R.
As the DC-9 approached the airport th e crew observed
a thunderstorm 7 m iles in d iameter, just to the west.
The crew began a n ILS approach to 21R, and at 1650
hours Eastern Standard Time (EST) th ey descended first
to 3000 feet, then 2600 feet. While in the descent they
entered a near -solid cloud deck. The flight crew
continued to observe area thunderstorm s on radar ,
noting that a thunderstorm west of the fi eld produced
the strongest returns. As they discussed its location 10
nm away, the controller announ ced, ' M etro visibility is
two m iles'. A Learjet on an ILS approach to runway
21L at the same time asked the controller for a weather
update. T h e con troller responded with current
conditions, includ ing: ' ... thunderstorm in progress' .
The captain of Flight 183 understood the discu ssion
related to weather at the a irport, b ut sin ce the Learjet
was landing on runway 21 L h e assumed the
information did not apply to runway 21R. The first
officer later said he could not determine the
thunderstorm's location from lhc discu ssion. Neither
p ilot requested add itional weather information . At 1653
hours, the crew discussed missed approach procedures
for runway 21R, a nd their concern about the
thunderstorm west of the field. As th ey talked, the
controller a n nounced airport visibility had decreased to
one mile. The first officer stated later he observed cells
on their final approach path, but did not consider them
an impediment to landin g. T he crew tuned in the local
tower frequency and heard : ' Winds are 320 degrees at
26, peak gusts 36, north bounda ry winds 270 degrees at
16 , east bou ndary winds 3 10 at eight, south boundary
wi nds 290 degrees at 22'. The fl ight crew stated they
recalled the tra nsmission but did not consider it a wind
shear alert. The capta in said the tran smission indicated
rapidly shiftin g winds, a nd the first officer said he
th ought it was m erely add ition al wind data. At 1655 the
captain said ' It's go ing to get choppy ... here in a
minute . .. '
Flight 183 th en broke out of the clouds momentarily,
and th e crew could see a low grey-wh ite layer of clouds
Aviation Safety Diges t 130 I 9
�along th e localiser course t o 21R. At 1655 hours, the
first officer ca lled , ' Runway a pproach lights in sight'.
A t th is tim e the con troller stated that she observed the
a irport visibility had d ropped to one-qu arter of a m ile
because of rai n . Fligh t 183 entered the low-lying clo uds
a bo ut 350 feet above the ground , an d simul ta neou sly
encountered h eavy rain, h ail an d turbulen ce .
The captain lost sigh t of the r unway environ ment
a nd im med iately started a m issed approach . H e called
fo r gear up , advanced t he throttles to the mecha nica l
stop s a nd rotated the a ircraft to a 15 ° n ose-up att itude .
H e noted the ind icated airsp eed increased to about 140
kno ts . Afte r passing the m iddle marker , the aircraft
flew ou t of the rain and hail shaft and the p ilot saw the
run way . H e felt the aircraft was still descending an d
contact w ith the ru nwa y was in ev ita ble. The captain
th en ordered : ' D own the gear , down th e gear ' .
Followin g this comma nd , he pushed the nose over lo
ensure a level to uchdown , and pulled the th rust levers
back to reduce power..
The D C -9 landed at 1656 ho ur s, about 2000 fee t
beyon d the th resho ld of runway 2 1R, with its gear
parti ally extended . The aircraft skidded about 3800 fee t
on the runway before sl id ing in to the grass on the left
side of the runway . There were no fatalities or serious
inju r ies , althou gh three crew m em bers a nd seven
p assengers suffe red minor injuries . The D C -9 was
severely damaged .
Analysis
T he Nation al Transpo rtat ion Sa fety Board (NT SB)
focused their investigation on th e factor s impin ging on
the p ilots' decision -m akin g processes an d flying
abilities .
Weather. T he D C -9 flight crew observed a conto uring
cell about 5-8 miles west-sout h-west of D etroit. T h is
sto r m wa s not reported via ATIS because of the rapid
d evelopment of the stor m cell and the gro und clutter o n
the D etroit rad ar wh ich prevented the o bserver from
receiving a true radar pictu re of the airport proper. T he
cap tain of a no th er ai rcra ft just beh ind Fligh t 183 saw a
cell of 'sign ificant intensity ' moving across t he nor thern
portion of the field vi a his weather radar a t the time of
the accident.
The D etroit N ational Weather Service ( NWS) station
visually obse rved a thun derstor m three miles west of the
field at 1635 h ours.
The Board concluded the thunde rstorm which
a ffected Flight 183 was part of an a rea of scattered cells
which were obser ved as early as 16 15 ho urs by pilots
a nd ground observe rs. The thunderstorm , which was
VIP levels
Echo intensity
weak
1
2
3
4
5
6
moderate
strong
very strong
intense
extreme
Rainfall rate (in.lhr)
0.2 (light)
0.2-1 .1 (moderate)
1.1-2.2 (heavy)
2.2- 4.5 (very heavy)
4.5- 7.1 (intense)
7 .1 (extreme)
10 I Aviation Safety Digest 130
over the airpo rt at 1656 hours , intensified rapidly as it
ap proached the field from west to cast. The Board
further concluded the storm wa s of V IP (Video
I ntegrator P rocesso r equipm ent) level 4 and travelli ng
at about 30 knots . The V IP level was con fi rmed by a
1730 hou rs weath er radar o bservation a nd the
associated heavy rain , 1:1 -in ch hail, a nd wind gusts u p
to 42 knots . T he centre of the cell passed over the
approach en d of r unway 2 1R , which placed the rain
and h ail shaft in' the pa th of Flight 183.
Aircraft p erfor m a nce. Analys is of fli ght data recorder
info r m at ion revealed conclu sively the airci-aft was
su bjected to wildl y d ivergen t winds ch aracterist ic o f
m icrobursts as it passed through the heavy ra in and
h ail. It con fir med the capta in ' s assessm en t of the
airspeed in cre ase to 143 k nots followed by a ra pid
decrease to 119 knots. The data clearly in dicated ,
however , that the ai rcraft rem a ined in level fl ig ht, even
a s the airspeed decayed. Yet even with maximum
power th e a ircraft d id n ot achieve a posit ive climb rate .
In fact, the a irspeed dec reased at a rate of two
knots/ second. (In no -wind cond itions, the a ircr aft would
have been accelerating a t abo ut fo ur knots/ second ra te .)
This revealed a severe wind shear with ,an actual wind
change of about six knots/ seco nd . The NTSB concl uded
th at the pilot probably avei-ted a cata strophe by
in it iating th e go-ar ound . As the a ircraft flew out of the
rain and hail sha ft, the p ilot perce ived a dec rease in
airspeed and a con tin ued descent .
T he captain was the victim of a visual ill u sion. As
the a ircraft em er ged from the weather, h is visual cues
in creased rap id ly, giving h im the sensat ion he was
approaching the g round. Meanwh ile , the cockp it
instrum ents available to both pi lo ts showed level flight.
Given the cap tain 's perceptio n of the circ umstances, h is
decision to lower the gear and reduce power wa s
appropria te. The fl igh t data recorder, however, showed
that even wh en he reduced power , the !AS actually
in creased , su pport in g the h ypothesis tha t the D C -9 h a d
penetrated the severe wind shear and had ach ieved
cli m b capability when it struck the runway .
T he NT SB felt a well-t ra ined , alert capta in sho uld
have bee n a ware tha t the ai rcraft would re sum e posi ti ve
performance after exit ing a micr~burst . They fell the
captain should have contin ued the m issed app roach
once he ini tia ted one. By reducing power, however , the
pilot co m m itted the a ircraft to land ing befo re the gear
was down. T he Safety Board fe lt the pilot' s kn owledge
that he was over the runway should have m itigated his
concern a bou t possible ground contact afte r the land in g
gear was down d uring th e con tin ued missed approach .
Indication
Light to moderate turbulence is possi ble with lightning.
Light to moderate turbu lence is possible with light ning.
Severe turbulence possible, lightning.
Severe t urbulence li kely, lightning.
Severe t urbu lence, li ght ning , org anised wi nd gusts.
Severe t urbulence, large hail, lightning, extensive wind
gust s and turbu lence.
T he refore, rather than reduce power and commit
himself to a la ndin g before the landing gear was fully
d ow n , the Safety Bo ard believes that the proper
d ecision would have been to continue the missed
approach eve n after the landing gear was lowered and
even if a ' touch-and -go ' on the runway proved
necessary to p reve nt fu rther loss of a irspeed.
The Sa fety Boar d fel t , in thi s instance , that the
overrid ing factor wh ich shou ld have affected the pilot's
decis ion was the location of th understorms near the
ai rfield . T he crew was aware a thunderstor m wa s no
mo re than five m iles west of the field, probably closer,
as they reached the outer m arker. T hey were also aware
that the thunderstor m was affecting the wind conditions
at the field . Gi ven th is in fo r mation, the Board felt the
crew sho uld h ave been aware they would enter
th un derstorm -related weat her cond itions if they
con tin ued the !LS app ro ach to runway 2 1R, and
therefore the cap tain' s d ecision to continue was
inappropriate .
C ockpit management . A lack of preparation and
ant icipation characterised the flight crew's managem ent
of the fi nal portion of the fli gh t. Wh ile the crew
accomplished all req ui red a ction s, the y did not discuss
the special situation they were in . T he crew made no
requests fo r any of the following: weather . updates
(desp ite obvio us discrepancies between reality and the
ATIS), clarificat ion of the wind data provided (despite
confusion as to its sig nificance by both pilots),
clar ification of the location of a known thun derstorm
(despi te its obv io us p roxim ity) .
Furt her indica ti ons of the flight crew's unprepared
sta le in cl uded fl yin g the DC-9 into the centre of a
thunderstorm; lack o f anticipation of thunderstor m related weather; and lack of recognition of these
phenomena at onset . T he re sult of this lack of
preparation was confusion in the cockpit - the
decision -m aking process broke down . The capta in's
belief that he was being 'pushed down ' was actually a
decrease in airsp eed, not a loss of altitude . His
perception of immin ent ground contact was
overwhelm ing and wen t unchal lenged, despite the fact
th e ai rcraft instrume nts worked properly a nd were
avai lable to both p ilots . T he pilot's decision to land was
b ased on his 'seat· of the pants' interpretation of the
eve nts, not the actual situation .
T he Safety Boa rd also poi nted out that the first
office r fail ed to sup por t the captain, save mandatory
checklist item s, nor did he provide any information. In
fact, he d id no t question the information h e ha d , even
thou gh he was unsure of its significance. The Safety
Board felt the first officer should have been more
aggressive in resolvin g h is conce rns about the existin g
condition s, and sh ould have voiced his concerns to the
pilot. His u n certaint ies should have led him to
d iscussing th e fea sibili ty of abandoning the approach . .
In this mishap , the NTSB saw little indication of
leadership from the capta in, nor any crew
augm en ta tion fro m the co-pilot .
T his m isha p clearly h ighlights the nece ssity for
a ircrew a ssert iveness and co-ord ination training - e.g.
cockpit in fo rmation m a n agement training . T he NTSB
feels tra ining in crew co-ordination a nd decision-making
should be req u ired fo r all crew members as these skills
are essen tial for the safe operation of aircraft .
Conclusions
T he NTSB had 27 find ings in this mishap. The
following nine are the most directly related to the causal
sequence :
1. A V IP level four th understorm passed over ,the
northern portion of the air port and the threshold of
runway 2 1R as Flight 183 approached decision height .
2. T he flight crew had sufficient information upon
which to make a decision to start a m issed approach
before enter ing the thunderstorm .
3 . T he a ircraft was flown in to the thunderstorm before
a missed approach was started , a nd the missed
approach was initiated as the aircraft passed through
the centre of the rain and hail shaft.
4 . T he a ircraft's rate of descent was stopped by the
initiation of the missed approach, and th e aircraft was
flown a t a constant altitude fo r about 16 seconds.
5 . The ai rcraft was capable of main ta ining level flight
d urin g the missed approach .
6 . The captain ' s belief that the aircraft would not climb
was infl ue nced by the incorrect perception of
information, an d the physical consequences of en tering
t he thunder storm cell, i.e . the rain, hail, and effect on
the aircraft's pitch att itude.
7 . T he captain elected to lan d the aircraft when he saw
the runway, although the aircraft may have been
capable of contin ued safe flight.
8 . There was inadequate crew co-ordination and
management during the instrument approach a nd
missed approach .
9. T he first officer failed to assist the captain to the
fu llest ex tent possible un de r the circumstances by not
vo icing his uncertainty abo ut airport weather
conditions.
Probable ca use
T he National Transportation Safety Board determined
the probable cause of the accident was inadequate
cockpit co-ordination and management, which resulted
in the captain 's inappropriate decision to contin ue the
instrument approach into known thunderstorm activi ty
where the aircraft encountered severe wind shear •
Ada/J/ed from NTSBIAAR-85-01 by The Mac Flyer
Flexibility
Frankfur t Approach: ' L ufthansa 343 expect an I LS
approach to runway 25 Left '.
Luftha nsa 343 : ' O h, that's a pity!'
Frankfurt A pproach: 'Why?'
L ufthansa 343: 'Well, we had actually prepared
for an ILS approach to runway 25 R ight , but it
doesn't m atter, we'll take 25 Le ft. We are
flexible ' .
Frankfurt Approach : 'So a re we. Expected
runway 25 R ight '.
Aviation Safety Digest 130 I 11
�Assessing the conditions
The Terminal Aerodrome Forecast (TAF) can be a valuable indicator of what to watch out for. It is
then the pilot's responsibility to judge the actual conditions.
p
A Piper PA-23 on a charter flight arrived at an island
and confirmed that they were operating normally. He
airstrip to find a heavy rainshower overhead the
concluded that he had not hit anyth ing wi th the
destinat ion. The pilot orbited for about five minutes a
propellers, but rather with the undercarriage. H e
few miles south-west of the island while the squall
therefore decided to leave the wheels down and
passed. When the airstrip became visible he began an
complete the flight back to his home base. However,
approach to runway 32. He did not check the windsock
shortly afterwards, he retracted the gear to in crease the
until the Aztec was on a very wide base position , at
rate of climb. The 'gear down' green lights
which time he estimated the wind as coming from the
extinguished but the 'gear up' light failed to illuminate.
north-east quarter at about five knots. The approach
The pilot looked at the mirror on the engine cowling
was continued using a planned t?reshold speed of 80
and observed that the nosewheel was still down but was
knots .
slightly back from its normal position .
On arrival at home base he carried out a flypast for
Touchdown was made left of centre in the first
visual inspection. I t was confirmed that the mainwheels
quarter of the strip . About 300 metres in from the
were fully retracted but the nosewhccl was down and
threshold this strip has a 'hump'. Braking was
cocked about 90 degrees. The undercarriage was
commenced well before this was reached. As the PA-23
selected 'down' and extended normally•and th ree greens
passed over the hump the pilot noticed that the more
were obtained. H owever, during the landing the
level section of the strip had extensive areas of water
nosewheel collapsed on contact with the runway .
lying on it.
At this stage he felt the Aztec's brakes lock and
Investigation
thought that the deceleration was less than expected .
Passing the windsock (which was about two-thirds of
A T AF was not obtained by the pilot before the fligh t.
the distance down the strip), the pilot noticed that it
The forecast wind for the strip in fact was 110/ 16,
was now indicating a tailwind component for runway
which would predict a tailwind component of 14 knots
32. With the airspeed indicator still showing 45 knots,
on runway 32 . Of course, a forecast can be one thing
he began to doubt that he would be able to stop the
and actual conditions another; nevertheless, a
aircraft in the d istance remaining. The possibility of
knowledge of the overall pattern is helpful in making
groundlooping the Piper was briefly considered and
assessments of the weather and trends. In this case, the
rejected in favour of a go-around.
rainshowers in the area were expected to influence
Power was applied and the aircraft eventually became
landing conditions. Not only was there a forecast
airborne two metres beyond the marked end of the
possibility of water on the grass strip but also
strip . Full flap was still selected . The nosewheel struck a
substan tial variations in wind speed and direction were
glancing blow on the top of a 1.3 metre-h igh fencepost
/ likely to be associated with the squalls.
45 metres past the marked end of the strip. This caused
The forecast was an accurate warn ing of the expected
the nosewheel to be offset 90 degrees to the airflow .
conditions a nd in light of th is warning, the pilot's
The pilot heard the noise of the impact and, once he
inspection of the runway and assessmen t of the wind
had established a safe fl yi ng speed, checked the engines
seems a little cursory e
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Airstrip from position at which pilot checked windsock (circled). Landing direction is arrowed.
12 I Aviation Safety Digest 130
Avia tion Safety Digest 130 I i
�~
Aircraft accident reports
AGPS
Second quarter 1986
Send to:
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Cessna Al88B·Al, Chinchilla Qld, Apr. 86, Aerial agriculture.
The pilot reported that during a crosswind spray run along a
fence line the left wing struck a tree. Despite extensive
damage to the wing, the aircraft remained airborne and the
pilot was able to land the aircraft at the departure strip,
some 3 kilometres away.
Beech 95-C55, Coolangatta Qld, Apr. 86, Instructional dual.
Prior to landing, the gear was selected down and a normal
gear down indication obtained. The touchdown was normal
but when the airspeed was reduced to about 65 knots, a
vibration similar to a wheel shimmy developed. Attempts
were made to keep the aircraft straight with brake and rudder but when it was realised that the right maingear was not
supporting the aircraft, the right engine was shut down.
Investigation revealed that t he uplock bracket spring had
become detached from the uplock bracket. This, along with
some corrosion and stiffness in the bracket at tachment bolt,
caused the bracket and uplock not to be withdrawn during
the extension sequence. As a result the extension rod was
bent during the extension cycle and t he right gear did not
extend.
Victa 100, Michelton Vic., Apr. 86, Non-commercial pleasure.
The pilot reported that the aircraft brakes were serviceable
prior to departure. However, during the landing roll the
brakes did not operate and aircraft overran the strip and ran
t hrough a fence.
Cessna 180K, Caramut Vic., Apr. 86, Non-commercial pleasure.
On arrival at his destination, the pilot overflew t he
homestead to indicate that transport from the nearby strip
was required. The aircraft was then seen apparently following a gully containing a sunflower crop in which the pilot
and passenger were partners. Shortly afterwards the sounds
of an impact were heard. The aircraft was found to have
struck the side of the gully while in a steep nosedown
attitude and probably rotating to the right.
Transavia PL12, Seymour, Vic., Apr. 86, Aerial agriculture.
The pilot had been spreading in the general area of the strip
for most of the afternoon. When he commenced operations
on a paddock to the south of the strip an area of sink was
experienced on approach. To allow for this on following
flights, he reduced the weight of the load to be carried and
another six flights were completed successfully. As the ·pilot
was turning the aircraft to align it for the next run, he encountered an area of sink and turbulence. Realising t hat the
aircraft would not clear a line of trees, t he pilot continued
t he t um to t he left but t he angle of bank suddenly increased
and t he nose pit ched down. The pilot dumped the load and
applied right rudder but the aircraft struck the ground
heavily.
Cessna 210L, Mt Botham Vic., May 86, Non·commercial pleasure.
At about 200 feet above ground level on final approach t he
pilot noticed kangaroos near the threshold. He adjusted the
approach to fly over the animals but the aircraft was subsequently landed heavily about four metres t o t he right of
the centre of the strip. The aircraft slewed to the right and
struck a windrow. The right maingear and nosegear folded
and the aircraft slid to a halt 105 metres after the point of
touchdown.
Cessna 210N, Wingelinna W.A., May 86, Non-commercial business.
The aircraft arrived in the circuit area in the late afternoon.
The pilot assessed that the prevailing wind would ma ke it
necessary to land into t he sun on strip 29. The aircraft
t ouched down on the left side of the strip and t he pilot look·
ed out of t he left window in an attempt to keep the aircraft
aligned wit h the strip. However, he did not see three half
200-litre steel drums that were located 14 metres off the left
side of t he strip and the left mainwheel struck one of these
drums. The left maingear folded and t he aircraft slewed to
t he left and became entangled in t he perimet er fence before
coming to rest.
De Havilland DHC·2, Cooma N.S.W., May 86, Aerial
agriculture.
During the takeoff roll, the left mainwheel struck a tyre
which was being used as a strip marker. The tyre deflected
into the tailplane; however, the pilot did not feel t he impact
and discovered t he damage at the conclusion of the flight.
An inspection indicated that the tyre had been moved from
its normal position prior to the impact, and was hidden from
the pilot's view by the long grass on the strip.
Aviation Safety Digest 130 I iii
�Beech E33, Bendana Qld, Mey 86, Non-commercial pleasure.
Prior to the flight the pilot ascertained that the strip was
serviceable, although rain had fallen in the area. The
previous aircraft had landed without difficulty. However, as
the pilot of VH-ENU applied braking after touchdown, the
aircraft began to slide. The pilot considered carrying out a
go-around but elected to continue with the landing. The aircraft overran the strip and travelled 67 metres before stopping.
.(
Avions Pierre Robin R-2160, Camden N.S.W., May 86,
Instructional - solo (supervised).
The pilot had been briefed to carry out her first period of
solo aerobatic manoeuvres. The period was to include spins,
loops, rolls, stall turns etc. About 30 minutes after departure
for the aerobatic training area, the aircraft was observed at a
relatively low altitude, spinning or spiralling towards the
ground. The rotation continued until the aircraft collided
with a group of large trees and fell to t he ground.
Cessna 182, Durham Downs Qld, May 86, Non-commercial aerial mustering.
The pilot had only recently arrived in the area and had not
operated from this strip previously. On his first takeoff from
the strip he decided to conduct a short-field takeoff. The aircraft became airborne after a ground roll of about 250 metres
but after travelling a further 110 metres, the wingtip struck
the ground. The aircraft landed heavily and ran off the side
of the strip. The pilot continued with the attempted takeoff
and the aircraft travelled a further 325 metres before the
t akeoff was abandoned when the aircraft s truck trees.
Piper P A23-250, Essendon Vic., May 86, Instructional check.
The pilot was carrying out a preflight inspection of the aircraft in preparation for an instrument rating flight test. He
had selected the flaps down, and began operating the
hydraulic hand pump to extend the flaps. After a few pump
cycles, the right maingear collapsed and the pilot then noted
that the gear selector was in the up position. Initial investi·
gation revealed that the anti-retraction valve, which is
designed to prevent gear retraction on the ground, was
unserviceable.
Beech 58, Crooble N.S.W., May 86, Charter - passenger
operations.
At the completion of one leg of the flight, the passengers
disembarked and the pilot prepared to ferry the aircraft to
another aerodrome in preparation for the next day's flying.
The strip in use was constructed of crushed limestone laid on
black soil. The pilot taxied onto the black soil at one end of
the s trip as he prepared to carry out a 180 degree turn to
line up for takeoff. The nosegear entered a hole about 150
millimetres deep, and collapsed.
Transevie PL12, Bunbury W.A., June 86, Aerial agriculture.
The pilot was engaged in spreading fertilizer on a forest. The
airstrip being used was in a valley and to fly to t he area of
operation the aircraft had to cross a ridge line. As the air·
craft approached the ridge the pilot stated that he noticed
that the aircraft was descending; he applied full power and
jettisoned the load. However, the stub wing of the aircraft
struck some tall trees below the top of the ridge and a short
distance later the forward flight of the aircraft was arrested
when it collided with a large tree. The aircraft slid down the
tree and became wedged between it and two other trees. The
pilot was able to evacuate himself from the wreckage and
walk to the airstrip.
Cessna 172M, Mt Surprise Qld, June 86, Aerial mustering.
The aircraft was being flown at about 900 feet above ground
level while the pilot spott ed horses for a programmed
iv I Aviation Safety Digest 130
muster. When the pilot attempted to increase engine power
he found that there was no response to t hrottle movement
other than a decrease in power to idle. The pilot was unable
to correct the situation and selected the best available area
for landing. This area was covered with small basalt
boulders. On touchdown, the left wing struck a small dead
tree and the propeller struck t he ground before the aircraft
came to rest.
An inspection of the aircraft revealed that the outer throttle
cable had come loose from the clamp at the engine. This
allowed power to be reduced but not increased.
Beech C23, Echuca Vic., June 86, Instructional - solo
(supervised).
The pilot was conducting a series of circuits a nd la ndings
following a period of dual instruction. During one of these
landings the aircraft landed heavily and bounced several
times. The nosegear and propeller were damaged before the
aircraft was brought to a halt.
Cessna A152, Parafield S.A., June 86, Non-commercial practice.
The pilot had intended to carry out aerobatic practice in the
Dry Creek Aerobatic Training Area. After departure, the
pilot requested, and was cleared, to operate in the Dry Creek
area up to an altitude of 3500 feet. The aifcraft was then
observed to be spinning and crashed into a salt-evaporation
pan.
Piper PA-32-RT300, Fraser Is. Vic., June 86, Non-commercial
- pleasure.
The pilot was approaching to land into the south. The wind
at the time was from t he south-west and gusting to about 30
knots. The first half of the strip was sheltered from the wind
by a solid line of tall scrub and trees. The aircraft did not
touch down when t he pilot flared for landing and a go-around
was initiated. At a height of about 10 feet and passing
abeam of the sheltered area , the aircraft suddenly moved
violently to the left. The nose dropped sharply and t he
nosewheel dragged on the ground for some 10 metres before
the pilot was able to continue the go-around. A diversion to a
more suitable aerodrome was made, where a post-landing
inspection revealed that the nosegear had been bent
sideways by the previous ground contact.
Cessna 210L, Ascot Vic., June 86, Non-commercial pleasure.
The pilot's flight plan indicated that he would reach his
destination 20 minutes before last light. During the flight
this estimate was amended to 7 minutes before last light. As
the en route weather was satisfactory, the pilot proceeded as
planned. However, about 10 kilometres from the aerodrome,
rain showers and deteriorating visibility were encountered
and t he pilot did not consider it safe t o continue. There was
insufficient daylight remaining to reach the planned alter·
nate aerodrome, and the pilot elected to carry out a pre·
cautionary landing on a sealed stretch of road. The aircraft
touched down normally, but then began to drift to t he right.
A go-around was init iated, but the tailplane struck a fence
post. The force of this impact almost tore the tail section
from the aircraft. The pilot felt the impact but was unaware
of the extent of the damage until after he landed the aircraft
in the adjoining paddock.
Piper PA-24-250, Barraba N.S.W., June 86, Non-commercial
- pleasure.
The aircraft arrived at t he destination strip about 40
minutes after last light. Weather conditions in the area were
good, with light winds and clear skies; however , the nig ht
was very dark and there was no visible horizon. Witnesses
on the ground reported t hat the aircraft seemed to be at a
normal height on the crosswind leg and as it turned into
downwind. However , it was then seen to enter a gradual but
steady descent. About half-way along the downwind leg, the
lights of the aircraft were lost to sight. The aircraft impacted
the ground in a stright-and-level attitude, bounced 118
metres, and then bounced and skidded for a further 216
metres before coming to rest.
Piper PA-60-600, Bankstown N.S.W., June 86, Charter cargo operations.
As the pilot approached his destination he was advised that
he was number three in the landing sequence. A visual,
straight-in approach was made in clear, dark conditions.
After receiving a landing clearance a normal flare was made,
and it was not until t he aircraft settled onto the runway sur·
face that the pilot realised that the gear was retracted.
Cessna U206G, Mabuig Is. Qld, June 86, Charter passenger operations.
The pilot reported that the aircraft encountered turbulence
late on the final approach. This resulted in a heavy landing,
during which t he left maingear and nosegear were deformed.
Piper PA-32-300, Broken Hill N.S.W., June 86, Noncommercial - pleasure.
The pilot was conducting a flight under Night VMC from his
property to Broken Hill. About 30 minutes after departure,
t he pilot reported that the aircraft engine was running
roughly. Shortly afterwards, he reported that the engine
cowling had become detached and then that the aircraft was
on fire. No further transmissions were received from the aircraft which was destroyed as a result of impact forces and
fire.
Cessna 150K, Wondagee Stn W.A., June 86, Aerial
mustering.
The a ircraft was being flown at about 200 feet agl in a left
turn while the pilot was attempting to locate some sheep.
The pilot reported that the aircraft stalled and that during
the recovery it struck a bush. This resulted in damage to the
right mainplane, right wing strut, right horizontal stabiliser
and the brake lines on both mainwheels. The pilot was able
to maintain control of the aircraft and land at a nearby
airstrip.
De Havilland DH-82, Shute Harbour Qld, June 86, Charter passenger operations.
The pilot reported that as he applied full power for takeoff,
the aircraft began to swing to the left. He was unable to correct the situation and the aircraft ran off the strip and collided with t rees.
The nosewheel had become detached and the nose strut was
pulled away from the firewall.
Hughes 269C, Moorabbin Vic., Apr. 86, Instructional - dual.
Following a period of general training, a practice autorotational landing was made. A moderately firm touchdown
occurred and a repeat of t he exercise was requested by t he
instructor. Touchdown on this occasion was normal;
however, during t he ground slide, the right landing gear
collapsed.
Hughes 269C, Ormiston Gorge N.T., Apr. 86, Aerial mapping/
photography/survey.
As the pilot was overflying the Ranger's cottage, he noticed
two rangers run out, waving frantically. Believing they
required assistance he landed the helicopter in the nearby car
park. The rangers approached the helicopter and urged the
pilot to move the helicopter as they were about to commence
blasting. In his haste to clear the area the pilot overpitched
the rotor blades. He attempted to land the helicopter on an
access road but the main rotor blade struck tall scrub, t he
aircraft yawed to the left and the tailrotor collided with the
base of the bush before the helicopter landed.
Hughes 269C, Theda Stn W.A., May 86, Aeria l mustering.
The helicopter was hovering at 50 feet agl when there was a
partial loss of engine power. An autorotational descent was
commenced but the aircraft struck trees and landed heavily.
Inspection of the engine indicated that the exhaust valve
guide and spring cap on number 2 cylinder failed allowing
the exhaust valve to drop into the cylinder t hus causing the
loss of power.
Bell 47G-2, Camden N.S.W., May 86, Non-commercial practice.
The aircraft had recently been sold, and had been ferried
from Moorabbin to Camden by the previous owner. The
Chief Flying Instructor for the company which had pur·
chased the aircraft arranged to be taken for a re·
familiarisation flight, as he had not flown the type for almost
one year. During a practice autorotative landing, the
helicopter fell heavily to the ground from a height of about 6
feet. The tail boom was severed and the bubble canopy was
shattered. The matter of which pilot was in command and
which was manipulating the controls has not yet been
resolved.
Beech 95-B55, Ballina N.S.W., June 86, Non-commercial,
business.
During the takeoff roll t he aircraft had reached a speed of
about 85 knots when the left engine suddently lost power.
The pilot immediately closed both throttles and applied braking, but was unable to prevent the aircraft over-running the
730-metre strip. The landing gear was torn out before the aircraft came to rest. Initial investigation revealed that t he
takeoff attempt had been made wit h the fuel tanks selected
to t he auxiliary positions, and these tanks were about one·
quarter full. It is probable that the fuel ports became uncovered as a result of the takeoff acceleration, allowing the
ingestion of air to t he fuel system.
Bell 47G-3B·l, Killarney N.T., June 86, Aerial mustering.
Three helicopters were engaged in t he mustering of cattle on
the property. One became unserviceable during t he afternoon
but returned to the muster after rectification. By 1830 hours
the herd of 4000 cattle were near the homestead and one of
the pilots was instructed to return to the homestead and
land. The other two helicopters continued t he muster using
t he landing lights of the aircraft for lighting. Last light in
the area was 1842 hours.
At about 1910 hours the muster was nearing completion and
t he pilot of VH-HMX was instructed by the property
overseer to move his aircraft away from the herd. Shortly
afterwards the pilot of the other aircraft observed a fire, and
upon investigation found the wreckage of VH-HMX. The aircraft had struck the ground in a steep nose-down attitude
while banked at about 90 degrees to the left.
Cessna 210L, Ballina N.S.W., June 86, Non-commercial pleasure.
The aircraft crossed the threshold higher than t he pilot
desired, and touchdown occurred well into t he 730-metre
strip. After initially running normally along the ground, the
aircraft bounced twice before coming to rest in a nosedown
attitude. Investigation revealed that the aircraft had landed
on the left side of the strip, where the surface was very
rough, and the aircraft had suffered a broken nosegear fork.
Bell 206B, Cunnamulla Qld , June 86, Power and pipeline
control.
The helicopter was engaged in an inspection of the oil
pipeline between Jackson and St George. The inspection in·
volved landing at various points along t he pipeline to allow
the technicians to check t he pipeline. As the aircraft took off
after an inspection stop, t he front seat passenger warned the
pilot about the position of a power line. The pilot attempted
to take avoiding action but the aircraft struck the power
Aviation Safety Digest 130 I v
�by a grass tussock. The severed section of the leg punctured
the right wing and the tailplane as the aircraft slid to a halt.
Initial investigation indicated that the failure of the leg was
caused by fatigue.
A subsequent metallurgical examination confirmed that the
leg fractured because of the growth to critical size of a
fatigue crack. The fatigue had originated in small surface
imperfections caused by corrosion pitting.
Rockwell 114, Sea Lake Vic., Jan. 86, PPL/Cl. l, 1000 hrs.
Shortly after takeoff the pilot's door opened. The passenger
became very agitated and the pilot elected to carry out a
low-level circuit and landing. The passenger's condition
deteriorated to the extent where the pilot was experiencing
difficulty in concentrating on the approach. The aircraft
touched down in a paddock 22 metres short of the aerodrome
boundary fence, ran through the fence and came to rest near
the strip threshold.
Atmospheric conditions at the time were conducive to the
formation of downdraughts and willy-willies. It was possible
that the aircraft was affected by such a disturbance at a
time when the pilot was distracted by his passenger's
condition.
Piper PA-28-Rl80, Mansfield Vic., Jan. 86, PPL, 130 hrs.
The pilot had intended to carry out a scenic flight which
would include aerial photography of a property at Merrijig.
An en route landing was not planned, but the pilot subsequently advised that one of his passengers became unwell
and a decision was made to land at a grass strip near the
property. Takeoff from this strip was commenced about 90
minutes later, and the acceleration was reported to be slower
than expected. The aircraft was pulled into the air near the
end of the strip, but it then descended, ran through two
fences and collided with some disused farm machinery. It
came to rest in a nearby riverbed.
Prior to the attempted takeoff, the pilot had made calculations from the performance charts in the aircraft. However,
the strip was 100 metres shorter than estimated, and the
pilot also incorrectly assessed the takeoff weight of the aircraft. Based on the corrected figures, the charts indicated
that about 1030 metres would have been required for takeoff.
The strip being used was only 550 metres in length and,
although it had a downslope, it was covered in grass some 20
centimetres high. The long grass had s lowed the rate of
acceleration of the aircraft and flying speed could not be
obtained under the conditions.
De Hnvilland DH82-A, Bond Springs N.T., Jan. 86,
SCPL/Cl. 4, 3600 hrs.
About 450 metres from the start of the takeoff run the air·
craft became airborne, but almost immediately sank back
onto the ground. The aircraft then veered sharply to the
right, and the pilot was unable to regain directional control.
The aircraft ran off the side of the strip and struck an
embankment before coming to rest inverted.
No defect could be foui:id with the engine, flight controls or
brake system and the aircraft weight and centre of gravity
were within the required limits. Since fitment of the braking
system, the aircraft's recorded time in service was 27 hours.
However, examination of the brake shoes revealed an exces·
sive rate of wear which was consistent with the brakes being
applied during takeoff or landing. The left gear brake shoes
were found to have suffered greater wear than the right gear
brake shoes and a cable within the braking system was
found to be incorrectly adjusted such that on application of
the brakes, a differential braking force would be produced
which favoured the left wheel. A progressive application of
right rudder would be required to overcome this differential
braking effect as speed increased during a takeoff run while
brakes were applied.
The takeoff run was significantly longer than was normal for
the prevailing conditions and this flight was to be the pilot's
second in an aircraft of this t ype fitted with brakes.
viii I Aviation Safety Digest 130
Cessna 152, French Island Vic., Feb. 86, PPL, 52 hrs.
The pilot was carrying out various manoeuvres in the train·
ing area. After about an hour general flying, the pilot
decided to conduct a practice forced landing approach to a
disused strip on the island. At about 200 feet on final ap·
proach, the pilot moved the carburettor heat control to the
cold position and applied full power to overshoot. The engine
failed to respond normally, and produced only about 1500
rpm. The pilot exercised the throttle control without obtaining any further power increase, and he was then committed
to a forced landing. Touchdown occurred in a cleared paddock and damage to the nosegear and propeller was sustained when the aircraft ran through a ditch.
No fault was subsequently found with the engine or its
associated systems. Reference to the appropriate chart indicated that atmospheric conditions were conducive to the
formation of moderate to severe carburettor icing. Although
carburettor heat was selected at the start of the forced landing practice, it was likely that some icing had already formed
and was not dispersed by the time the throttle was re·
opened. When the engine failed to deliver full power, the
pilot had not re-applied carburettor heat in an effort to
restore normal engine operation.
Piper P A-25-235, Lady Barron Tas., Feb. 86, CPL, 11000 hrs.
The pilot was using his aircraft for agricultural operations on
his own land. The aircraft had been performing normally during the day; however, on this particular takeoff, the engine
lost power when the aircraft had reached about 55 knots.
There was insufficient strip length remaining for the pilot to
stop the aircraft, which struck several fences before coming
to rest in a ditch 50 metres beyond the end of the strip.
Despite an extensive examination of the engine and
associated systems, the reason for the power loss could not
be determined.
Transavia PL12-T300A, Nannup W.A., Feb. 86, CPL/Ag.
Cl. I, 5900 hrs.
The pilot was operating from a strip on top of a ridge line.
Because of the slope of the strip, landings were being made
with a quartering tailwing of about 10 to 15 knots. At the
end of a landing roll, the pilot commenced to turn around
prior to reloading when the wind gusted to about 25 knots.
The pilot applied more power in order to assist the turn, but
the nosewheel bounced into the air. The aircraft weathercocked and ran off the side of the strip. It then ran down the
slope of the ridge line until the nosewheel entered a large
hole and the aircraft overturned.
The pilot had attempted to turn the aircraft around for
reloading while traversing an area of rough ground adjacent
to a steep slope at the side of the strip. All previous turns to
position for reloading had been conducted on a flat area on
the opposite side of t he strip. However, the pilot decided to
reverse the direction of turn to assist the loader driver who
was experiencing difficulty in positioning the loader close to
the aircraft.
Beech 95-C55, Brampton Is. Qld, Feb. 86, CPL/Cl. 1, 1450 hrs.
The pilot reported that shortly after takeoff he positioned
the fuel selector to feed fuel to the right engine from the
right auxiliary fuel tank. After levelling the aircraft at the
cruising altitude of 1500 feet, he noticed the right engine
falter, and immediately positioned the fuel selector for that
engine to 'crossfeed'. The right engine then stopped. The
right engine fuel selector was then positioned to draw fuel
from the right main fuel tank; however, the engine did not
restart. The left engine then stopped, and attempts to
restart it were unsuccessful. The pilot transmitted a
'Mayday' call and ditched the aircraft.
Only the engines of the aircraft were recovered; however, no
fault was found with them that could have contributed to
the accident. It is probable that the disruption of power from
the right engine was due to the depletion of fuel in the right
auxiliary fuel tank. The reason the left engine failed could
not be determined; however, it is likely that air entered the
fuel system when the pilot selected the right fuel selector to
'crossfeed'. It is probably that the left engine could not be
restarted because there was insufficient time to purge the
fuel system of air before the aircraft ditched.
The manufacturer's operating manual for the aircraft limits
the use of 'crossfeed' to operations where fuel is used to
operate only one engine. It also requires the auxiliary pump
be selected on, to stabilise the fuel flow, prior to crossfeed
selection.
Cessna 150H, Koonmarra Stn W.A., Feb. 86, RPPL, 189 hrs.
The pilot was engaged in sheep spotting. The aircraft had
been refuelled two days prior to the flight, and before departure the pilot had checked the fuel contents gauges, which
indicated full fuel. After about two hours of the planned
three-hour flight, the pilot noticed that one of the fuel contents gauges indicated empty and the other almost full. As
he was near one of the property airstrips, the pilot decided to
land the aircraft and dip the tanks. Having apparently
satisfied himself that sufficient fuel remained, he continued
the flight. An hour later, as he was returning to the station
airstrip, the engine stopped. The aircraft was landed on a
road but during the landing roll the left wing struck a tree
and the aircraft ran off the road and into the bush, sustaining further damage.
An inspection of the aircraft revealed that the engine had
stopped after the usable fuel had been exhausted. The fuel
gauge for the right fuel tank was found to overread by 10
litres; however, the reason the fuel had been exhausted after
a flight time of only three hours could not be positively
determined.
Piper PA-18-150, Katherine N.T., Feb. 86, PPL, 113 hrs.
Near the end of the landing roll the left wing rose and the
aircraft lifted off the strip, then settled back onto the ground
on the right mainwheel. The brakes were still applied and the
aircraft turned sharply to the right and the right wing
struck the ground. The aircraft rolled over and came to rest
inverted.
The pilot had assessed the crosswind component affecting
the main property strip as being close to the maximum for
the aircraft type. He had therefore decided to use an
adjacent area which was aligned into wind, but because of
the position of buildings at the end of the area a go-around
was not possible. It is possible that mechanical turbulence
from the buildings affected the aircraft during the landing
roll. The approach was conducted at a higher airspeed than
that recommended in the P-charts, and heavy braking was
applied on touchdown before the tailwheel had contacted the
ground.
Piper PA-28-161, Alice Springs N.T., Feb. 86, Student, 10 hrs.
After a dual check, the pilot's instructor briefed the pilot to
carry out two circuits, each with a full-stop landing. Follow·
ing the first circuit and landing, the pilot applied power to
commence the takeoff without bringing the aircraft to a
stop. The aircraft veered sharply to the left and became airborne momentarily before settling back onto the ground outside the flight strip. Flaps were selected fully down and the
aircraft continued under full power across a stormwater
drain for another 38 metres before coming to rest.
This was the pilot's second solo exercise. Following the loss
of directional control, it appears that the pilot became con·
fused and did not apply the correct control inputs to bring
the aircraft to a stop.
Parteoavia P-68C-TC, Orbost Vic., Mar. 86, SCPL/Cl. l,
2450brs.
The pilot was preparing to depart from a strip which was
only marginally longer than t he minimum length required.
He reported that when ta keoff power was applied, an over·
boost warning light illuminated. Although a considerable
power reduction was required on the right engine before the
light extinguished, the pilot continued with the takeoff
attempt. He advanced the right throttle to match the posi-
tion of the left lever, but as the aircraft became airborne it
struck the boundary fence and the left mainwheel was
dislodged. The pilot elected to return for a landing at the
strip. During the landing roll, the left gear leg collapsed and
the aircraft ran off the side of the strip.
No fault was subsequently found with the engines and
associated systems of the aircraft. The overboost warning
light system fitted to the aircraft type is characterised by a
significant lag during power reduction. The normal method
of re-setting power under these circumstances is by reference
to the manifold pressure gauges. Although the strip was
marginal for the intended operation, the engines were not
advanced to a high-power setting before the brakes were
released.
Cessna 150L, Alice Springs N.T., Mar. 86, PPL, 149 hrs.
At the completion of a local pleasure flight the pilot decided
to carry out three practice circuits. The first two landings
were without incident but on the third landing the aircraft
touched down on the right mainwheel and bounced. The pilot
applied power in an attempt to stabilise the aircraft but the
angle of bank to the right increased and the right wing
struck the ground. The aircraft cartwheeled onto the left
wing and came to rest inverted, 190 metres to the right of
the runway centreline.
The landing was attempted in gusty crosswind conditions.
The aircraft manufacturer's owners manual recommends that
a mimimum flap setting be used in these conditions;
however, on this occasion the pilot selected full flap. The
pilot stated that when the aircraft bounced, he attempted to
raise the right wing by the application of left aileron but seeing the skid ball was well out to the right, he then applied
right rudder. The aircraft then rolled rapidly to the right and
the wing struck the ground.
Cessna 150M, Geelong Airport Vic., Mar. 86, CPL/Cl. 1,
1000 hrs.
The flight was intended to be a revision exercise in crosswind
circuits and landings. The first landing was completed
satisfactorily and the student subsequently advised that the
flaps were raised to the takeoff setting and full power was
applied. However, the instructor reported that only partial
power was applied and he said to the student 'I've got the
flaps '. The student believed the comment was 'Take it off',
and she responded by closing the throttle. The instructor
took control and continued the takeoff, but the tail tie-down
ring struck the boundary fence and the aircraft then collided
with mounds of soil beyond the fence.
The investigation was unable to resolve the apparent confusion which existed in the cockpit with regard to the
amount of power the student applied or the phraseology
which was used by the instructor. At the point where the
student closed the throttle, the instructor considered that
insufficient strip distance remained to stop the aircraft.
Cessna 172M, Walcha N.S.W., Mar. 86, Student, 26 hrs.
At the conclusion of a dua l check-flight, the student landed
the aircraft into a light north-westerly wind. T he landing roll
was completed about half-way along the 838-metre strip, and
the pilot turned the aircraft around preparatory to taxiing
back to the upwind threshold. The instructor left the aircraft
at this point after briefing the student on the solo sequences
he wished him to practise. Shortly afterwards, full power was
applied as the student commenced a takeoff downwind. The
aircraft failed to become airborne, collided with a fence and
overturned.
The student was subsequently unable to give any reason for
his decision to commence a takeoff roll from other than the
thresh.old of the strip.
Airparts 24, Armidale N.S.W., Mar. 86, CPL/Ag. Cl. l,
3500 hrs.
Before commencing the l 7th spreading flight for the day, the
pilot noted that one fuel tank indicated empty and the other
indicated one-quarter full. After a normal takeoff and turn at
Aviation Safety Digest 130 I ix
�:f
I~
about 150 feet above ground level, the engine lost all power.
The pilot was committed to a landing in a small paddock
with a downhill slope. Touchdown was made in light tailwind
conditions, and during an attempt to turn the aircraft to
lengthen the landing distance available, the left wing struck
the ground. The aircraft partially ground looped, one tyre
was rolled off its rim, and the aircraft came to rest within
the confines of the paddock. The pilot then physically
checked t he fuel tank contents and found that only a few
litres remained in one of the tanks while the other was
empty.
The loss of engine power was caused by fuel starvation. The
pilot had not previously flown t he aircraft and was not aware
of t he time the aircraft had been flown since it had last been
refuelled. He did not accurately determine the quantity of
fuel in the aircraft prior to commencing the operation, nor
did he have any method of determining the duration of the
flight. He relied solely on the fuel gauges to determine the
q uantity of fuel in the aircraft .
T his occurrence was not the s ubj ect of an on-site investigation.
I
Bellanca 8GCBC, Harts Range N.T., Mar. 86, PPL, 664 hrs.
During the landing roll, both mainwheels entered soft areas
in the strip surface. The aircraft swung t hrough 120 degrees
to the left, then slid sideways for 17 metres before the right
maingear collapsed. The wing struck the ground and was
bent upwards.
The condition of the strip surface was unsatisfactory because
the first 500 metres contained soft spots. The positions of
the soft spots were not marked nor was the strip threshold
displaced. The pilot had used the strip previously but on this
occasion he did not check its serviceability before the flight.
Piper PA-28-161, Narrogin W.A., Mar. 86, PPL/Cl. 4, 167 hrs.
The pilot, who held a Class Four Instrument Rating, had
planned the flight as currency training. At Narrogin, he set
the aircraft up on a long final approach but reported that on
several occasions during the approach, he found that the aircraft became low and he needed to adjust the flight path.
About midway along final, the pilot stated that he felt a
thump on the left side of the aircraft but the aircraft continued to operate normally, so he continued with the approach and landing. After parking the aircraft the damage to
the left wing was noticed.
The pilot had a total of 15 hours night flying experience and
this was the first time since obtaining his Class Four Instru·
ment Rating, some 12 months previously, that he had landed
an aircraft at night at any location other than Jandakot. The
pilot stated that he had developed the habit of carrying out
a flat approach to ensure he made good his nominated
touchdown point. He believes he carried out the same pro·
cedure on this occasion. The tree struck by the aircraft was
15 metres high and situated about 500 metres before the
strip threshold, it was below the required approach gradient.
Piper PA-28-161. Lilydale Vic., Mar. 68, Student, 25 hrs.
The pilot was conducting her second solo flight. She reported
that following a normal approach, the aircraft touched down
and bounced. She was unable to correct the situation and a
further two bounces occurred before the aircraft could be
brought to rest. An inspection revealed damage to the
nosegear assembly and the engine mounts.
Piper PA-29-250, Benkstown N.S.W., Jen. 85, CPL/Cl. 4,
830hrs.
The pilot reported t hat the three gear-posit ion indicator
lights were green as he commenced the takeoff roll. At about
40 knots the gear commenced to retract and the aircraft slid
to a halt with all wheels retracted and the position lights
indicating that the gear was up and locked.
No fault was subsequently found with the landing gear
system which might have contributed to the accident. The
pilot had not checked the position of the gear selector lever
x I Aviation Safety Digest 130
during his preflight and prestart checks. The sequence of
events during the attempted takeoff was consistent with the
selector being in the up position. The gear system includes
an anti-retraction valve which prevents inadvertent retraction while the weight of the aircraft is on the mainwheels.
When the aircraft had reached about 40 knots, there was
evidently sufficient lift being developed to allow the antiretraction valve to close and the gear to retract.
Cessna 404, Canberra A.C.T., Mar. 85, SCPL/Cl. l, 6528 hrs.
In order to avoid thunderstorms in t he immediate vicinity,
the pilot requested takeoff from a runway direction giving a
slight downwind component. Light rain was falling at the
time, but it increased in intensity shortly after t he aircraft
commenced to roll. The initial stage of the takeoff run was
normal, but the aircraft then failed to accelerate. The takeoff
was abandoned at about 65 knots Indicated Air Speed;
however, braking effectiveness was reduced because of the
wet runway conditions. A ground loop was attempted, the
nosegear subsequently became detached and the aircraft slid
sideways into the aerodrome boundary fence.
No fault or defect was subsequently found with the aircraft
engines, propellers or braking system which might have contributed to t he development of the accident. A detailed
engineering study revealed that under the existing conditions the wind velocity, rainfall rate and runway slope corn·
bined to prevent normal drainage off the runway. As a
result, water tended to pool on the runway -to a greater
depth than anticipated. Quantitative estimates indicated
that under these conditions, the rate of acceleration of an air·
craft could be reduced by up to 50 per cent. When the pilot
abandoned the takeoff attempt and applied the brakes, the
depth of water present was such that the aircraft commenced to aquaplane.
Beech 65, Biloela Qld, Aug. 85, SCPL/Cl. 1, 11575 hrs.
This aircraft had only recently been acquired by the com·
pany. It had a fuel system different to other aircraft of the
same type in the fleet. On the other aircraft there were three
detents for each fuel selector: On, Off, Crossfeed. On this aircraft there were four detents: Off, Outboard, Inboard,
Crossfeed. The pilot had not previously flown this aircraft.
After a flight time of about 110 minutes the pilot reported
that both engines had stopped and he was unable to access
fuel from the outboard tanks. When the wreckage was
located, no evidence of fuel was found in the inboard tanks.
An inspection of the wreckage did not reveal any fault with
the engines or fuel system which may have contributed to
the occurrence. It was evident that the engines had stopped
when the fuel from the inboard tanks was exhausted. A
quantity of fuel remained in the outboard tanks.
The day prior to this flight the pilot was briefed on the fuel
system of VH-FDR by the company check pilot. The briefing
was carried out with the use of the pilots operating manual
for the aircraft. Because VH-FDR was not available at the
time, the pilot was not able to study the fuel management
panel in daylight hours. It is not known if the pilot
familiarised himself with the panel before commencing the
flight.
The aircraft is normally operated with the inboard tanks
selected for takeoff. Evidence was obtained from flight
documentation found in the wreckage which indicated that
the pilot had changed the fuel selections from inboard about
30 minutes before he reported that the engines had stopped.
However, the exhaustion of the fuel contained in the inboard
tanks indicates that the selectors could not have been cor·
rectly positioned in the detents for the outboard tanks. Tests
carried out found that if the selectors were positioned
between the inboard and outboard detents, sufficient fuel, to
allow the engines to be operated, would still be drawn from
the inboard tanks.
The reason the pilot was unable to access fuel from the outboard tanks could not be determined.
Cessna 310R, Pt Hedland W.A., Sept. 85, SCPl.JCI. 1.
Prior to touchdown the gear-position indicator indicated that
the gear was down. During the landing roll the right main
gear collapsed and t he right wing, engine, propeller and flap
struck t he ground.
Collapse of t he right maingear resulted from excessive wear
of t he right overcent re lock bush bearing. The reason for the
excessive ra te of wear of t he bush could not be determined.
Thirty-six la ndings had been recorded since the last
scheduled maintenance inspection of the gear and it is considered t ha t some evidence of the excessive wear should have
been present at that inspection.
Cessna 172N, Pinjarra W.A., Nov. 85, PPL, 500 hrs.
Prior t o attempting t he landing the pilot carried out an aerial
inspection of t he strip. The aircraft touched down on a
gravel road leading to the strip; however, the ground track
of the aircraft was affected by a windrow along the side of
t he road and t he pilot was unable to control the aircraft. The
pilot applied power to carry out a go·around, but the right
mainwheel struck a car tyre, which was used to mark the
strip t hreshold, causing t he aircraft to veer to the left
towards a fence. The pilot managed to manoeuvre the aircra ft over t he fence but it struck the ground, wingtip first, in
an adjacent paddock.
The surface of t he strip within the boundary markers consisted of a 4 metre wide road and the pilot was apprehensive
about its use. However, following t he conduct of a circuit at
the strip by the aircraft's owner , the pilot decided to use the
strip, as t he passenger s were waiting to depart for
Geraldton. On t he ret urn flight the pilot was apprehensive
a bout the la nding, but decided not to divert to a nearby air·
field because of the likelihood of the passengers experiencing
subseq uent t ra nsport ation delays. To increase the landing
distance available, the pilot decided to land short of the
threshold marked by t he tyres at the edge of the road. Once
on t he ground, t he pilot 's view of the tyres was restricted by
long grass.
Victa 115, Victor Harbour S.A., Nov. 85, PPL, 1312 hrs.
The pilot had arranged to take each of his guests on a scenic
flight of t he local area. On the second of these flights, the
passenger took along a video camera. The aircraft was
observed flying at a low altitude and subsequently struck
the top wire of a 10 metre high three-strand power line. The
aircraft t hen continued towards rising ground and climbed
over a row of t rees before descending rapidly into the
ground. A fire broke out and consumed the fuselage of the
aircraft.
An inspection of the wreckage revealed that only the underside of t he rear of t he aircraft had struck the wire. It is con·
sidered unlikely that t his impact would have adversely af·
fected the control of t he aircraft, other than to reduce its
a irspeed. The inspection did not reveal any other defect that
could have contributed to t he occurrence.
It is probable that as the aircraft was climbing over the
trees it stalled and that there was insufficient altitude
available for t he pilot to recover the aircraft. Both occupants
survived the impact but were apparently unable to evacuate
the a ircraft and died in the subsequent fire.
Piper PA-18-150, Meekatharra W.A., Dec. 85, PPL, 4143 hrs.
The pilo t was engaged in sheep mustering. The aircraft was
being flown at 200 feet agl, and about three minutes after
t he fuel tank selection was changed, the engine lost power.
The pilot selected the other fuel tank but the engine did not
respond. The aircra ft touched down heavily on unsuitable
terrain and t he main gear collapsed.
No defect was found with the engine and 55 litres of fuel was
drained from t he fuel system following the accident. It is
considered probable that the loss of power resulted from fuel
starvation caused by the pilot inadvertently turning t he fuel
selector beyond the correct position. An inspection of t he
fuel selector valve found that it had been incorrectly
assembled. This resulted in t here hr ing no effective detent to
indicate t hat the selector had beei. ..:orrectly positioned. Also
it was found that if the selector was positioned slightly
beyond the required position, fuel flow was considerably
restricted.
Bell 47G-2, Colson Camp N.T., Jan. 86, CPL-H, 340 hrs.
The aircraft was carrying out a survey in a remote area.
When last light occurred, the aircraft was still some distance
from the base camp. The pilot decided to follow a road into
the camp. En route t he engine lost power and an autorotat ion descent was carried out for a landing on the road. Dur·
ing the landing the left skid struck a low dirt bank and the
tail rotor struck t he dirt bank on the opposite side of the
road.
Throughout the survey the pilot had used a higher-thannormal cruise power setting, but had not recalculated the
endurance for the higher fuel usage. The engine fa iled after
t he fuel became exhausted.
H ughes 269C, Hughendon Qld, Feb. 86, CPL·H, 8121 hrs.
The helicopter was being used as a platform for test equip·
ment. Part of t he test equipment included an aerial that was
mounted vertically below the helicopter. This aerial could be
retracted and stowed in a horizontal position for landing by
operating a control which was positioned in front of the
technician. On this occasion t he pilot inadvertently attempted to land the helicopter wit h the aerial extended. J ust prior
to touchdown the helicopter began to vibrate, the pilot
lowered the collective and the helicopter rolled onto its right
side.
Following the completion of each test it was normal for the
technician to raise the aerial prior to landing. On this occa·
sion, the technician became engrossed with the transmission
of test data and forgot to retract the aerial. The pilot was
concentrating on the landing and neglected to ensure that
the aerial had been retracted.
Normally if a landing is attempted with the aerial extended,
a weak link in the system fails and the aerial is retracted by
a spring. However, it is believed that because the helicopter
touched down with little forward speed, the weak link did
not fail at the required time in the landing sequence.
Enstrom F-28F, Narellan N.S.W., Mar. 86, CPL·H, 574 hrs.
The pilot had been carrying out a series of joy flights at a
rural field day . Refuelling was taking place from 200-litre
drums, which had been placed in the shade of a large tree.
On the second occasion that fuel was required, the pilot
hover-taxied to the drums, which were rolled out of t he way
on completion of t he refuelling. As the pilot started to hovertaxi again, the helicopter suddenly rose higher than an·
ticipated and the main rotor struck the overhanging
branches of the tree. One rotor blade de-laminated, severe
vibration occurred, and t he helicopter struck the ground
heavily.
With the helicopter hover-taxiing two feet above t he ground,
there was only three feet of clearance between the rotor
blades and the tree branches. The reason t he helicopter rose
sharply and struck the branches was not determined, but
may have been the result of a wind gust.
Bell 206B, Nowra N.S.W., Oct. 85, CPL-H/CI. 4, 5140 hrs.
The helicopter had been chartered because the passenger's
farm had been isolated by floodwaters. The crew carried out
a survey of t he area before landing to check the suit ability of
tlie chosen site. Shortly after takeoff, t he aircraft collided
wit h a power line which was about 25 feet agl, and then
struck the ground heavily about 15 metres beyond the line.
Both the pilot and the crewman reported that they had
sighted t he power line during t he survey prior to landing.
However, the pilot subsequently forgot the presence of the
line and conducted a shallow climb after takeoff. Because the
rear seat cushions were wet, the passenger was placed in t he
front seat while the crewman occupied the rear seat. When
he became aware that the helicopter was climbing at a
shallow angle, he reminded the pilot to beware of the wires.
Aviation Safety Digest 130 I xi
�T
The pilot then saw the power line directly ahead of the aircraft, but was unable to avoid the collision.
Bell 206B, Spencers Brook W.A., Dec. 85, CPL-H/Cl. 4,
3355hrs.
The helicopter was being used as an airborne filming platform. It was being flown at about 30 feet above ground level
along the side of a roadway, while the film crew filmed a bus
that was travelling along the road. The helicopter was
observed to gain altitude and pass over a power line, then
descend again to 30 feet above ground level. After travelling
a further 500 metres the helicopter struck a spur line running from the main power line, then pitched nose-up before
descending out of control and colliding with the ground. The
wreckage slid 50 metres before coming to rest on the road.
The position of both the s un and the support poles of the
spur line would have made detection of the line difficult
unless the pilot had prior knowledge of its position. The pilot
was not seen to conduct a survey of the area for obstacles
prior to commencing low-level operations. The task required
the pilot to concentrate on the bus to the right of the
helicopter as well as the flight path ahead.
Examination of the wreckage did not reveal any malfunction
which may have contributed to the occurrence. It appeared
that on impact with the spur line, one cable contacted the
bottom of the windscreen pillar and the other became
entangled in the rotor blades. All significant damage to the
aircraft appeared to have resulted from ground impact.
Aerospatiale SA-341G, Mt Perisher N.S.W., Dec. 85, CPLH/Cl. 4, 5018 hrs.
The helicopter was being used to transport empty fuel drums
from a dump at an elevation of about 6500 feet on the summit of the mountain to the valley floor. One load of five
drums had been successfully lifted about 10 minutes
previously, and the pilot returned to sling load a further four
drums. He subsequently reported that as he began to lift the
drums he detected a change in the engine note. The load was
immediately jettisoned, but the engine continued to wind
down and the pilot was committed to a landing in a confined
clearing. Full collective was applied to arrest the forward
speed and the aircraft landed heavily. After the helicopter
had come to rest, the pilot extinguished a small fire which
had broken out at the rear of the engine compartment.
At the time of the accident, the helicopter was being
operated well within its performance capabilities. When the
heavy touchdown occurred, the exhaust pipe was severely
distorted, restricting the flow of exhaust gases. As a result,
the turbine assembly experienced an extreme over·
temperature condition and t he blades and guide vanes were
melted before the engine was shut down. This damage
precluded the investigation of any possible malfunction of
the assembly during the hover immedia tely before the engine
apparently lost power. No other defect or malfunction was
discovered and the reason for the reported loss of power
remains undertermined.
Romainian 1S-28B2, Leongatha Vic., Jan. 86, Glider, 1043 hrs.
The pilot, who was also the holder of a Private Pilot Licence,
was conducting his first gliding flight for the day. The glider
was aerotowed to 1100 feet above the aerodrome, but only
weak lift was encountered in the area. The pilot elected to
return for landing and commenced a normal circuit. On the
downwind leg, strong sink was encountered and the base
turn was conducted at about 300 feet above the ground
Indicated airspeed at the time was reported to be about 55
knots. The pilot subsequently advised that the roll into the
turn was normal, but he was unable to level the wings again,
even with full opposite aileron. The aircraft continued
descending in a wing-low attitude and struck t he ground
about 250 metres before the threshold of the strip.
Investigation revealed no evidence of a ny pre-impact defect
or malfunction of the controls, and astmospheric conditions
at the time were reported as being stable. When the sink was
encountered on the downwind leg, the pilot had modified his
circuit by flying closer to the s trip. As a result, the angle of
bank required for t he base turn was steeper than normal. It
xii I Aviation Safety Digest 130
•
was considered probable that the aircraft had stalled during
this turn onto base, with insufficient height remaining to
allow the pilot to recover control.
Schleicher KA-6, Temora N.S.W., Jan. 86, Glider, 130 hrs.
Towards the end of a 4 hour competition flight, the pilot
realised that the aircraft would not reach the finishing line
and that an outlanding would be necessary. After
establishing the aircraft on final approach to t he selected
paddock, the pilot noticed a pile of stones obstructing the
target touchdown area. While manoeuvring to avoid t his
obstruction, the left wing of the aircraft struck t he ground
and a ground loop ensued.
The pilot had been suffering the effects of a head cold and
sinus infection, and had probably become fatigued during the
flight in demanding conditions. He had persisted in his
efforts to reach the finish until the glider was too low to
allow a more suitable paddock to be selected for the outlanding.
This accident was not the subj ect of an on-site investigation.
Schneider ES~B. Ross Tas., Jan. 86, Glider, 51 hrs.
The pilot had been soaring in wave conditions when sink was
encountered and an outlanding became necessary. The field
initially selected was obstructed by a power line and the pilot
manoeuvred towards another area. On late final approach the
aircraft collided with a single-strand power line and sub·
sequently struck the ground heavily. The pilot later advised
that he had seen a pole supporting the line but had thought
it was aligned in another direction.
The large distance between the poles supporting the power
line reduced the possibility of the pilot being able to
accurately assess the direction of the line.
Rolladen LS4, Benalla Vic., Jan. 86, Foreign, 1562 hrs.
The pilot was a member of t he French team competing in the
'Austraglide '86' gliding championships. At the end of a
cross-country exercise the pilot reported that he was 5
kilometres from the finish line. The pilot of another glider
observed that when the subject aircraft was 1 kilometre from
the line it was apparently low. Shortly afterwards the glider
collided with power lines. The tailplane was cut off by this
impact and the glider t hen struck the ground in a steep nose·
down attitude.
The glider was seen leaving an area of thermal activity with
apparently sufficient altitude to complete t he flight to
Benalla. The reason why the glider subsequently descended
to the low altitude which resulted in t he collision with the
power lines could not be determined.
Glaser-Dirk DG300, Benalla Vic., Jan. 86, Glider.
The pilot was competing in the Austraglide '86 international
gliding championships. During a cross-country exercise a
number of gliders were thermalling in the same area. The
pilot noticed several gliders underneath his aircraft as he
entered the t hermal at about 4000 feet above ground level.
His entry was made via a 45 degree bank right turn, but
after t urning through about 90 degrees the left wingtip contacted t he forward under-fu selage area of a Discus B
sailplane, VH-HNZ. This aircraft had been in a left t urn with
about 12 degrees angle of bank. Following t he collision, both
aircraft remained under control and were flown to the planned destination without further incident.
Neither pilot saw the other aircraft prior to t he collision. VHHNZ and the other aircraft established in t he thermal were
t urning to the left. The pilot of D-2870 did not realise any
aircraft were above him, and elected to carry out right-hand
t urns. This procedure was contrary to the accepted practice
laid down by the competition organisers, where the direction
of t urns was governed by aircraft already in a thermal. The
pilot advised that he was turning towards the sun when t he
collision occurred.
Schemp Discus B, Benalla Vic., Jan. 86, Glider.
The pilot was competing in t he Austraglide '86 international
gliding championships. During a cross-country exercise a
number of gliders were thermalling in the same area. The
pilot noticed several gliders underneath his aircraft as he
entered the thermal at about 4000 feet above ground level.
His entry was made via a 45 degree bank right turn, but
after turning through about 90 degrees the left wingtip contacted the forward under-fuselage area of a Discus B
sailplane, VH-HNZ. This aircraft had been in a left turn wit h
about 12 degres angle of bank. Following the collision, both
aircraft remained under control and were flown to the planned destination without further incident.
Neither pilot saw t he other aircraft prior to the collision. VHHNZ and the ot her aircraft established in the thermal were
turning to the left. The pilot of D-2870 did not realise any
aircraft were above him, and elected to carry out right-hand
turns. This procedure was contrary to the accepted practice
laid down by the competition organisers, where the direction
of turns was governed by aircraft already in a thermal. The
pilot advised that he was t urning towards t he sun when the
collision occurred.
Glasflugel H206, Bacchus Marsh Vic., Mar. 86, Glider,
200 hrs.
Gliding operations during the day had been conducted on
strip 19. On this occasion the pilot planned to approach to
that strip but to land on the cross-strip 09, to a llow the
glider to complete its landing near the club hangar. During
the turn onto final approach, t o strip 09, t he pilot noticed a
tug air!!raft apparently making an approach to the same
strip: He continued his turn in order to avoid any conflict
with the tug, and the aircraft subsequently touched down
across strip 19. It t hen ran through a ditch before colliding
with a fence.
The tug pilot stated t hat he saw the glider and thought that
it would land on the left sife of strip 09. The t ug aircraft was
not fitted with a radio which denied two-way communications between the two aircraft. The two aircraft came into
close proximity and the glider lost excessive height as the
pilot forgot to retract t he airbrakes during t he turn to avoid
the tug aircraft. The tug pilot continued the approach and
landed but t he glider pilot was committed to a downwind
landing and attempted to la nd across the other strip.
Rolladen LS3, Forbes N.S.W., Dec. 85, Glider, 163 hrs.
An inst ructor who was watching the aircraft as it entered
the circuit estimated that the aircraft was about 200 feet too
low on the downwind leg. The base turn was conducted at
about 50 feet and during t he turn onto final the wing of the
glider struck the boundary fence. A subsequent examination
indicated that t he altimeter was over-reading by some 200
feet.
The altimeter had been set to indicate zero prior to departure. In the following four and a half hours, pressure changes
had occurred which resulted in the apparent over-reading.
During the circuit, the pilot had been concerned with other
traffic about to take off, and had attempted to alter t he flap
setting in order to modify the circuit. However, he had in·
advertently applied the dive brakes and the glider lost height
rapidly until the situation was corrected. A landing straight
ahead was considered, but t he pilot elected to try to reach
the strip. It was likely that he was suffering a degree of
fatigue after a long flight.
Czech Blanik Ll3, Woodbury Tas., Aug. 84, Glider, 232 hrs.
The student glider pilot had carried out three previous
flights during the day. Her instructor had informed her that
she was at a suitable stage of training to be introduced to
practise emergency procedures. After sighting her training
log book, t he instructor for the final fligh t left the glider to
speak to the pilot of the tug aircraft. The instruttor returned
to t he glider and preparations for takeoff were then continued.
Witnesses observed that the t ug and glider became airborne
and subsequently carried out normal turns to position t he
aircraft on a downwind leg at about 500 feet agl. The tug aircraft was then seen to waggle its wings sharply three times.
Almost immediately this aircraft assumed a steep nose-down
attit ude, its tail apparently being pulled into a vertical position by the tow rope which was still attached to the glider.
The glider then also assumed a steep nose-down attitude and
both aircraft spun or spiralled towards the ground. The tow
rope was released from both aircraft, but neither pilot
regained control before impact with t he ground.
The subsequent investigation did not disclose any defect or
malfunction with either aircraft t hat might have contributed
to t he development of t he accident.
During glider towing operations when the pilot of the tug
waggles the aircraft wing, it is a signal to the glider to
immediately release from the tow. This 'wave-off' signal
would normally be given when the tug pilot detects some
malfunction or when the glider is sufficiently far out of position behind the tug to affect the tug pilot's control of his aircraft.
On this occasion, it was considered likely that the instructor
in the glider had arranged for the tug pilot t o simulate an
emergency by giving a wave·off signal. The wave-off signal
was observed to be given in t he normal position relative to
the strip for such training manoeuvres to be performed. The
reason for the subsequent loss of both aircraft could not be
determined; however, it was evident that when the aircraft
released the tow rope there was insufficient height remaining
to permit recovery to normal flight.
Probable s ignificant factor s
There was sufficient evidence available to determine t he
precise cause of the accident. Nevertheless, the following
were considered to be probable factors in the development of
the occurrence:
1. The gliding instructor and t he tug pilot arranged to give
the student a practice emergency.
2. When the wave·off signal was given, t he glider did not
immediately release from the tow.
3. Control of both aircraft was lost at too low a height to
permit recovery.
Corrigendum
The following is an amended version of a final update which
appeared in Aviation Safety Digest 126. The report as
originally published indicated that one of the probable factors
in the occurrence was that the student glider pilot may have
been inadequately briefed before the flight. Following
representations from various parties the report was reviewed.
It was agreed that the assigned probable factor should be
deleted, as there was no evidence to show whether any briefing at all had in fact been given.
Aviation Safety Digest 130 I xiii
�Auiation Regulatory Prioposals
Aviation Regulatory Proposals (ARPs) are an important means by which the Department consults
with industry about proposed changes to operational legislation and requirements. Copies of all
proposals are circulated to relevant organisations, and occasionally to individuals for information and
comment. The comment received provides a valuable source of advice which greatly assists the
Department in the development of the completed documentation.
In future, each edition of the Digest will contain a listing of those ARPs circulated since the previous
edition.
As this is the first listing, it includes all ARPs on which action is still in train.
Should you wish further information about any of the ARPs, please contact your industry
organisation.
Number Subject
83/10
Separation requirment for VFR flights in
primary control zones
Sµpplementary Airline licence
83/15
requirements
84/4
Preferred runway procedures
84/10
Medical Standards
84/12
Safety Precautions during aerodrome
works
84/14
Instrument ratings
84/22
84/24
85/7
85/10
Operation of helicopters on aerodromes
Transit flights below 500ft - agricultural
operations
Aircraft Engine Emissions
Miscellaneous amendments of ANRs
Night aerial spraying
Aerodrome standards for ab-initio Pilot
Training
Sideways-facing seats
Ultralight Air-worthiness Standards
85/11
Minimum Runway Width
85/12
85/16
86/2
Aerial Agricultural Rating
Helicopter Winching and Rapelling
operations
CPL - Aeroplanes
86/4
CPL - Balloons
8616
86/8
Air Service Licence requirements charter and Aerial Work
Model Aircraft
86/11
Cabin Fire Safety
84/27
84/28
85/2
85/6
xiv I Aviation Safety Digest 130
Status
Awaiting action on ANR 94
ANO Amendment being processed
AIP being processed
ANO Amendment being processed
Comments under consideration
Comments closed 31 March '86 now under
consideration
'
Amendments being processed
ANO Amendment being processed
postponed pending overseas developments
ANR Amendments being processed
ANO Amendments being processed
AIP Amendment being processed
ANO Amendment being processed
Comments under consideration. No action
pending outcome of Parliamentary inquiry
Comments closed 1 June '86 now under
consideration
ANO Amendment being processed
Comments closed 31 March '86 now under
consideration
Comments closed 30 April '86 now under
consideration
Issued 24 June '86. Comments due 31 July
'86
Issued 7 April '86. Comments due 1
August '86
Issued 30 May '86. Comments due 30 June
'86
Issued 10 May '86. Comments due 13 June
'86
Aviation Safety Digest 130 I xv
�Ground-run
ji~co
As he was driving past the aerodrome where his
Amer ican Aviat io n AA5 -B was parked, the owner
decided on the spur or the moment to call in and give
its engine a ground-r un beca use the machine was not
being flown much, a nd a co u ple of months ago he had
noticed that the battery charge was low.
A rriving at the aircr aft , he opened the cockpit and
tr ied to start the engine. H owever, the battery was
com pletely d ischarged. Accordingl y, he decided to hand
swing the propeller.
T he p ilot checked that the park brake was set and
ensured that th e three tie-down ropes were in place . H e
opened t he throttle a n estimated one-quarter or an inch
and swung the propeller. T he engine fired on the thi rd
kick . I ni tially it 'sp lu ttered' , but then the rpm rapidly
increased to an obv iously high power setting .
L eaving the pro peller area, the pilot started to run
arou nd the right wing to return to the cockpit so that
he cou ld throttle the engine back. Just as he reached the
wingtip, the r ight tic-down rope snapped and the
aircraft began to m ove . The pilot managed to clamber
onto the wing nea r the cockpit, but before he could take
a ny action to retr ieve the situation he was thrown off
balance when the AAS's right wingtip struck the tail of
a Cessn a Aerobat.
At this stage both the tail and right wing tie~down
ropes had snapped, and the aircraft was starting to tu rn
to the left, swivelli ng around the left wing t ic-down
rope , which remained secure. The aircraft turned
through 180 degrees before running into a Cessna 182,
which was parked in the line behind the AA5 's original
position. The pilot was still hanging on when the
second impact occurred, and was su bseq uen tly able to
get into the cockpit and shu t down the engine.
All three aircraft were substantiall y damaged.
Lessons
T h e safety lessons emerging from this occurrence arc
self~evident in th e sequence of events identified by the
air safety investigator:
• The park brake was not set effectively.
• The wheels were not chocked.
• Assistan ce from another pilot was not obtained, even
though an aero club was only 100 metres away .
• The nylon rope tie-down s were rotten .
• Close to full throttle must have been set before the
propeller was swung.
• Once the engine started, the pilot was unable to
restrain or re-enter the r unaway aircraft •
The right wing of VH·IFS struck the tail of VH·FUH at A and continued in to VH· WFR.
xvi I Aviation Safety Digest 130
Aviation Safety Digest 130 I 13
�l
Human factors in wheels-up
landings
A rece nt wheels-up landi ng in western N .S.W. ra ised a
number of interesting questions which promp ted the
Bureau of Air Safety In vestigation to undertake a
co mputer-based rev iew of accidents and incidents of this
type , covering th e period January 1980 to March 1985.
T he variety of circumstances involved in each case
proved to be very wide as o ne mi ght expect; however ,
some co mmon factors emerged which are of inter est.
The particula r accident in western N .S.W. involved
a P iper PA28 ,in wh ich a n electrical failure d isabled the
aircraft's normal mea ns of gear extension. The pilot-incommand could not recall the procedu re used to
manually extend the gear an d the outcome was a
wheels-up land in g . A key point which emerged from
the in vestigation was that the aircraft handbook was
stowed in t he rear locker, and co ns'.::quently unavailable
to th e pilot. There were no injuries to the occupants
a ltho ugh the aircraft sustained severe d amage . Such an
avoidable accident led to this rev iew of all wheels-up
la ndings over the a bove period .
Analysis
T he total num ber of wheels- up la ndin gs was 171. These
accidents have not been separated according to category
of operatio n as the objective was to obtain an over view
14 I Avia tion Safety Diges t 130
of the relative importance o f h uman factors in probable
cau ses . Statistics ind icate that approximately 52 per
cent of wheels-u p landings were probably attributable to
human factors . Equipment m alfunct ions or failures
accounted for another 33 per cent o f the accidents ,
although th ese ha ve not been subdivided according to
hum an an d other facto rs. Approximately 1 per cent of
whee ls-up landin gs occurred as a result of conscious
pilot dec isions, and the remainder involved human ,
technical, weather and other factors in differing
combinations. Separation o f the statistics into two broad
categories of h uman and tech nical factors was made lo
facilitate the review, an d it is not suggested that a ll
accidents a re so easily separable . The probable cause o f
an individual acciden t usuall y involves several fac tors
acting sepa rately o r in combination .
By far the most com mon sho rtcom ing highlighted
a mon gst the 52 per cent of accidents in the h uman
factors group could be termed 'complacency' . P ilots
e ither m isused the checklist, failed to use it at all, or
recalled it inco rrectly fro m m emo ry . T here were several
instances where pilots followed the checklist precisely,
but in giv ing challe nge and r esponse made the cardinal
error of omittin g to check that the particular selector or
indicato r was in agreement with the checklist
requirem en t before giv ing the response . In nearly 10
per cent of cases the pilot stated that he or she ' forgot'
to sele.ct the gea r down prior to landing.
While man y of those pilots claimed they simply
for got to lower the gea r , others were able to identify
reasons which contributed to their accident. Some were
distracted by radio comm unications at a critical
moment, the presence of other tra ffic, a change of
r unway, a nd occasionall y personal stress. Personal
stress varied from pressures of the environment , due to
weather or syslcrn m a lfunctions, to family and domest ic
problems. O ccasio n.ally a pilot operated the wrong
selector when the a1rn was to lowe r the gear, and there
were several instances where the flaps were raised
instead of lowering the gear.
Some ligh t a ircraft wi th retractable undercarriage
systems have an a uto matic extension facility designed to
lower the gear sho uld the pilot omit this item in the
pre-landing check list. In addition, most aircraft have
a n aural warning system to alert the pilot that the gear
is still up when the t hrottle(s) is retarded with zero or
specific flap settings . The accident reports show that in
man y cases these automatic extension and warning
systems were either inoperative, malfunct ioning, or out
of adjustment.
T he classic case of continuing with an approach
wh ilst. the u ndercarriage warning horn was sounding
arose m several msta nces, while p ilots occasionally
pulled the undercar r iage warning horn circu it breaker
to silence an incorrectly adjusted system during flight
- then 'fo rgot ' to reset it duri ng the pre-land ing
checklist . Some li ght sin gles and twins have automatic
d imm ing to the undercarriage warning lights when the
navigatio n ligh ts are o n, and from time to time pilots
who were unaware of this characteristic on their type
fa iled to realise th at the gear was in fact down and
locked prior to landin g. Th is could then lead to further
non -standard manipulation of the normal and
emergency gear co n trols until a wheels-up landing
occurred .
Aircraft types involved over the whole spectrum of
these accidents ranged from a Grumman Gulfstream to
C essna 177RGs . Cessna 210 models accounted for 19
per cen t of the acciden ts, Piper PA28s 7 per cent, while
Cessna 310 and Beech A36 models each accounted for
4. 7 per cen t of the tot al.
Checklists
R egardless of the statist ics relating to individual types,
the Bureau is co ncerned about the high percentage of
wheels-up land ings involving human factors. Man y of
these acciden ts m ay have been avoidable wi th a more
thorough a tt itude towards checklists and better
knowledge of aircraft systems and emergency
procedures. A com placen t pilot makes the game tough
enough wi tho ut a lso leaving the aircraft manual in an
inaccessible place. Don't be complacent, know your
checklists and use them, understand the aircraft
systems, and have a sound grasp of abnormal,
alternative, and emergency systems. Automatic
extension system s a nd visual and aural warning devices
are intended to be back-u ps in properly conducted
operatio ns, and were never designed to prov ide pilots
with pri mary cues to lower the undercarriage prior to
la nd ing . T hat is the proper function of the chccklist .
Other factors
An approach with the gear up is conducive to higher
airspeeds, and in turn this may preclude the operation
of undercarriage warning systems. Highe r speeds may
also inhibit the operation of automatic extensi.~m devices
until the th rottle(s) is closed by wh ich time it is too late.
The review also revealed a number of instances in
which pilots made late gear-down selections, and landed
on partly exte nded gear. Incorrect application of
emergency drills with both fu lly funct ioning or
malfunction ing u ndercarriage systems often revealed a
low standard of knowledge with drills and systems .
Undercarriage componen ts are frequently exposed to
the elements with water, mud, and other debris being
th rown into wheel-well bays and o ther sensi tive a reas.
In one instance a pilot in northern Australia
demonstrated very poor airman ship by taki ng off from
an airstrip which was so rain -d renched and muddy, that
on arrival over the destination the gear could not be
shifted by ei ther normal or emergency me thods .
Conclusion
Airrnanship is a theme which should run through the
thougl~t processes and actions of pilots in all day-to-day
operat ions. In particular, the review of wheels-up
landing accidents pointed to a m isuse of checklists, and
in turn this frequentl y ind icates a poor standard of
a irmanship. ln the majority of cases there was no need
for haste in attempting to resolve an undercarriage
problem . It 1s far better to proceed to a quiet area and
carefully complete all drills relevant to the emergency,
than attempt lo deal with communications and other
traffic a t the same time . AT C and FSU officers arc also
usually on hand to assist pilots in an y way possible e
Look out ... listen out ...
It is not uncommon for instructors to turn down
the volume control of the radio to eliminate
distracting noises at tjmes when a student is
struggling to hear and to understand a particular
lesson.
In the training area there is some risk that in
doing so, a call from Flight Service or from
a11other aircraft will be m issed. Such a call could
be both important and urgent.
To turn down the radio volume in the circuit
area though is fraught with danget:, both for the
aircraft concerned and for everyone else in that
cirt:w t area.
Try to avoid turning down the volume at all. If
it is necessary to do so, keep the time to the
absolute minimum and don't forget that you have
turned it down . Under no circumstanees tum it down
wlzeri in the circuit area. The busiest, noisiest time
co uld be when it is most important that yo u listen
and remain atte ntive to radio transmissions •
Aviation Safety Digest 130 I 15
�Slung-load instability
~
I
I~
I
~ I
A Bell 206B Jetranger was bein g used to fer ry sl ung
loads between a ship and a shor e base . T he pilot had
ove r 2500 hou rs fl ight experience on rotar y wing
a ircraft but , apar t from a recent re famili arisation course
and th e p receding few days' operations, had no t flown
helicopters for two years. Carryi ng slung loads was not
covered during the refresher flying as at the time it was
not believed that the p ilot would be involved in th at
activity.
Following o ne ship to shore run , the pilot was asked
to b ackload a cont ainer wh ich was iden tical in
appeara nce to others h e had previou sly carried. The
load was hooked up and the B206 departed for the ship.
The pilot noted on li ft-off that this box was much
lighter than those he had shi fted before .
After levelling off a t about 120 feet agl and 60 k no ts,
the pi lot felt a bump o n the rear of the helicopter and
noticed that the m ach ine pitched up slightly. H e
coun tered t his m otion with cyclic . H owever, the 'bump'
and p itch-up occurred again , so he pressed the loadrelease b utton .
Almost immediately the helicopter started to yaw to
the righ t, so a descent fo r landing was init iated and
control inpu ts made to try to a rrest the yaw. H owever,
the aircraft contin ued to rotate and after seve ral turns
impacted the ground on the front of the right float,
wh ich h ad been inflated . The J etranger th en toppled
over onto its right side, sustainin g su bstantial damage.
The p ilot , who received minor inj uries, was able to
escape throu gh the broken can opy.
Protective clothing
Above. General view of aircra f t showing (1) base camp (2)
final resting place of bo x and (3) approximate position of
tailrotor wreckage.
Below. View of horizon tal stabilizer showin g ( 1) rop e securely
attached and (2) p oint of tailroto r shaft M eakage.
H ow m uch value do you place on your life? This is a
question that pilots employed in comparatively high risk operations such as aerial application and cattle
m ust ering should ask themselves when assessing the
cost of p rotective clothing. It is a question that
shou ld not be difficult for one particular pilot to
answer following the rapid return he got on just such
an investmen t .
The pilot was spraying a small crop of wheat and
had completed the first run. He began the second
run and was side-slipping around a large tree and
between telephone lines at a height of abou t 6-7 feet
AGL when, in his words, 'the windscreen shattered
and the inside of the cockpit was showered with
blood and guts'. P ulling his PA25 up and away from
the paddock, he determined that the aircraft's
windscreen had sustained a severe birdstrike. H e was
able to fl y back to his airstrip and spent the rest of
the morning cleaning the remains of a large
Cormoran t from the Piper's cockpit . (The bird's
weight was later assessed at about 3 Y2 kg.)
There is, however, more to this incident than that.
At the time of the birdstrike the pilot had been
wearing a helicopter-type SPH helmet, with visors,
that he had acquired ten days earlier. Again to use
the pilot's words ' . .. but for the fact that I had the
helmet on and the visor down the story would have
ended differently, as the bird came through the
perspex relatively intact and hit the visor with
considerable force' .
The helmet which almost certainly saved this
pilot's life retails for about $850. By any measure,
that amounts to a bargain . Readers should also note
that protective fl ying clothing may be tax deductible ,
either full y or through depreciation. The Department
of Aviation strongly supports the use of good quality
protective clothing by those pilots involved in
comparatively high risk operat ions •
Analysis
It was appa rent that the slu ng load had become
unstable and h ad struck the ta il boom . In fact, it had
also passed over the tail boom between it and the m ain
rotor, and was sitting on the tail boom - this
expla ined the b ump and pitch- up which was
exper ien ced twice. W hen the load was su bsequen tly
released, it slid back a nd was struck by the ta il rotor ,
breakin g off one blade and sn appin g the drive shaft.
G iven the invidiou s circu mstances, it is problem atical
whether the pilot could ha ve done a ny more tha n he
did . If the uncomm anded yaw was to be countered ,
t hen an alm ost immed iate a utorotation h ad to be
in it iated. The pilot later stated that he was not sure a t
fi rst whether the J etranger had suffered a tail roto r
fa ilure, for, while the loss of yaw control was total, it
was not severe (as 'is to be expected, tho ugh , the
severity increased as airspeed redu ced ). T he low
altitude a lso was a factor in his decision-making, as he
had li ttle time to thin k abou t alte rnative courses of
action . H is decision was to try to fly t he aircraft usin g
whatever cyclic control rem a ined, a nd to a ttem pt to
cu sh ion the impact by using the cyclic to raise the nose
and pulling full collective a t the last secon d. H e later
said th at at th e point of touchdown th e h elico pter had
little forward speed and was almost level.
The slung load
Dur ing the investigation it emerged that the box in the
sling may have had a defective latch. I t was postulated
16 I Aviation Safety Digest 130
Operational technique
that this m ay have allowed the box's lid to come open
o nce the load was airborne, thus creating extra drag
and causing the load to become unstable. There was
reason fo r some concern in the fact that th e loader had
not received any for mal train ing, and could not
remember if he had closed the latch properly. H e was
aware that one of the boxes being used had a defective
(bent) latch but could not remember if it was the one
used on th is particular flight. [Contin ued opposite.]
Some differen ce of opin ion was expressed by senior
check and training helicopter pilots regarding the
o perational aspects of the accident.
I t should be men tioned that once a pilot has received
an initial endor sement for slung-load operations,
refresher trainin g in the technique is not mandatory. A t
the same tim e, the consen sus among the senior pilots
with whom the BASI investigator spoke was that, while
the basics of the proced ure are not forgotten, the finer
po ints may take some time to resurface if a pilot has
n ot flown helicop ters for a year or so. In this regard ,
the training p ilot who conducted the Jetranger pilot 's
refresher said' that he would have included slu ng-load
operations in the training sequences had he known that
the pilot was going to be sent on the particular task.
General agreement was also reached on the issue of
'flying' the load . The collective opinion of the
specialists was th a t o nce the pilot had lifted the
conta iner off the ground and noted that it was light er
than the others, he should have treated it as an entirely
new load: he should h ave monitored it carefully in the
m irror attached to the aircraft for that purpose, and
been cautious a bout selecting a forward airspeed . The
key requ irement was to use a speed at which the load
would remain stable.
On this brief flight, the pilot had checked the load in
the mirror as he lifted the box clear of the ground , and
it had appeared to be sitting flat on its normal base,
while the net seemed symmetrical. A cruising speed of
60 knots was used as it had been on all other transits.
T he load was not checked again in the mirror until the
unexpected thumps were felt. It was because he then
could not see the load that the pilot decided to release
it.
Conclusion
This was a difficult and dangerous occurrence, in which
events unfolded rapidly. In the circumstances, the
bottom line is that the pilot walked away from it. At the
same time, as the BASI investigation showed, there were
a n umber of factors evident which should be of interest
to all those involved in this sort of operation.
Perhaps the final word should be given to a
helicopter specialist who, in an article in R otor News,
stated that:
There is no one set of rules that assures every load will fl y
the same . Quite often you may fl y the same type of load ;
and because of some minute difference of airspeed, wind
gust, rigging, etc. your next load could fl y erratically.
This accident was a case in point •
Aviation Safety Digest 130 I 17
�Compressor washing
During takeoff the engine instruments of a Bell 206B
were checked while the helicopter was in a hover. No
abnormalities were noted . However, just as forward
movement was commenced a loud noise was heard and
all engine power was lost. A significant drop in rotor
rpm occurred and, during the subsequent forced
lan ding , the main rotor struck the tail boom.
Post-accident inspection revealed a total mechanical
failure of the engine compressoi-.
The maj ority of compressor blades were found to be
broken and the resulting degree of damage precluded
identification of the location of the in iti al failure .
H owever, the exam inat ion of sections of blades r evealed
corrosion pitt ing consistent with inadequate compressor
washing servicin g.
The J ctrangcr had been opera ting in a corrosive
atmospheric environment, and it is probable that the
initial failure within the co mpressor resulted from
co rros ion-induced fatigue.
I t cont inues:
Engines su b jected lo salt water or other chem ically laden
atmosphere ( including pesticides) shal l undergo water
r insing after shu tdown follow ing the last fli!{ht of the day .
Pe rform the rinse operation as soon as practical after flight,
but not before the engine has cooled to near ambient
temperature.
Corrosive conditions
O perators should be aware that salt-laden air may be
encountered as far as 75 miles inland under certain
weather conditio ns. Furthermore, chemically burdened
air in the vicin ity of industrial complexes is a corrosive
source requi rin g the same daily maintenance as salt air
conditions. In some meteorological situations air
contamin a ted by ind ustrial waste may travel through
valleys a nd be fo und considerable distances from the
source .
Damage to compressor rotor.
Washing procedures
Technical investigation
D am age to the rotor of the Alliso n 250-C20 engine was
severe. The second, third and fourth stage rotor blades
ha d been completely strip ped from th e roto r a nd all that
was left were small 'stumps' at the ir roots. These
stumps h ad been severel y battered , prevent ing
conclusive analysis of the fracture surfaces. The damage
was consistent with the failure of a blade or vane in
stages 2, 3 or 4, probably stage 2 or 3 .
The co mpresso r was very d irt y, suggesting that it had
not been washed r egularly. Streakin gs of d irt co uld be
seen coming from pits o n the leading edges of blades in
three of the four rema ining stages of rotor blades. Dirt
could not be found on the other (fifth) stage beca use of
the damage to its leading edges cau sed by the break-up
o f the other stages . H owever, because pitting, foreign
object damage ( FOD) and dirt streaking we re found on
blades upstream and down stream of the stages that had
either failed or been badly damaged , it was clear that
there would have been sim il a r d a mage and st reaking on
the stages that had failed.
The cor rosion pitting, dirt s11·eakin g and amount of
dirt present indicated two main facts:
• the J etranger had been operated for a long period in
harsh and dirt y en vironments ; and
• the co m pressor had not been receiv ing rinses a nd
washin g as required by maintenance instructions.
Pitting, FOO damage and streaking on a sixth-stage rotor
blade.
Other infor mation unearthed during the investigat ion
in to a Jetranger accident indicated that one group of
military hel icopter s (presumably U.S.) which did no t
receive com pressor wash ing experienced a number of
low-time accidents at aro und the 200- 400 h our mark.
Also, one Australian operato r involved in sea rescue is
known to have had a failur e from corrosion fa tigue 188
ho urs after an ove rhaul. Consequently a program of
dai ly compresso r washing was introduced, and when
the compressor was subsequentl y split for inspection
after 300 ho urs of o peration, there was no sign of
corrosion .
Case studies
A let ter distributed by the All ison Company in 19 76
d iscussed the e ffectiveness o f compressor w ashin g in
rel ation to compressor fa il ures . It cited the example of a
helicopter organisation operatin g a flee t of 125 aircraft
in the Gulf of Mexico. At one stage the organisation
was experiencin g an average of a compressor fa il ure
every month. However , after purging the fleet of
corrosion-a ffected compon ents and inst itut ing daily
compressor wash es, they had not had a fa ilure for three
years - a nd during that time th e fleet h ad expanded to
170 a ircraft , each avernging more than 100 ho urs a
m onth .
18 I Aviation Safety Digest 130
Comment
The All iso n Operation and M a in tenance Manual for
the 250-C20 provides a specific warn in g regarding
corrosion as follows:
WA RNING
SALT LADEN HUMIDITY AN D CHEMICALS WILL
CORRODE COMPRESSOR BLADES AND VANES AND
CAUSE THEM TO FAIL.
Washing proced u res and the terminology used can vary
between eng ine m an ufacturers and operators. I n
general terms 'compressor wash ing' is used to defi ne a
procedu re intended to overcome contamination
problems . 'Washing ' is perhaps best defined and
understood as the following actions:
• Rinsing: the application of fresh/demineralised water
to remove de pos its accumulated by operation in salt
a nd/or chemically laden environments.
• C leaning: the appli cation of a chemical cleaning
solution to remove dirt and contaminant products
when performance is affected, followed by rinsing.
These processes can var y in procedure and the
method of application . Some general observations are,
however, val id:
• Fo r som e engines, rinsing without closing the bleed
valve/s allows water to exit the compressor via the
bleed valve orifice, leading to ineffectual rinsing of
the later stages of the compressor.
• C hemical cleaning must be followed by thorough
rinsing, because residual chemicals can be as
detrimental to the engine as a contaminated
environment.
• Accu m ulations of residual water in the engine
followi ng r insing can be harmful to systems· (e .g.
anti-ici ng , fuel control/governing) which use air
tapped off the corn pressor . Therefore, a drying-out
ground run is n ecessary to complete the rinsing
proced u re .
Preservation
Operators should al so appreciate that if an aircraft is
not go ing to be used for an extended period,
preservation of the com pressor is necessary to combat
co rrosive deterioration of stators and rotors. If a
compresso r has been pr eserved, thorough r insing is
essential before further flight.
Conclusion
Compressor washing can play an importa n t part in
engine safety . For t he exact procedures fo r yo ur
particular engine, con sult the relevant operation a nd
maintenance man ual •
In brief
During instruction in the use of VOR as a- fixing
aid, the VOR in an RAF HS-125 was tuned to
113.4 Mhz, but it continued to code (indent) and
indicate the previously selected beacon, which was
113 .5 Mhz. When a frequency of 112 .4 Mhz was
selected, the bearing and coding were those for
the beacon on 112 . 5 Mhz. The equipment was
eventually persuaded to operate on a frequency
which included 0.4 Mhz by stepping through 0 .1
to 0.3 Mhz.
This occurrence emphasises the need for a
careful check of the aural coding whenever a
navaid is retuned . T he selection of a new
frequenc y is no gu arantee that the information
displayed will be correct.
*
*
A Cessna 310 was cruising at 10 OOO feet when
the left-hand wing locker burst open and
discharged about 75 bags of surgical cotton balls.
The bags containing the cotton balls were sealed,
unvented, non -evacuated plastic containers. They
had expanded because of the reductio n in ambient
atmospheric pressure as the C310 climbed, to the
extent that they eventually forced the locker door
open .
*
*
An S-61 helicopter was engaged in transferring
one passenger and his baggage by winch to the
deck of a research ship. The passenger was
transferred without incident, but during the
winching down of his baggage the co-pilot
observed a black polythene dustbin bag being
drawn into the rotor d isc on the port side of the
aircraft. This was ingested into the n umber 2
engine, causing it to stall with a complete loss of
engine torque. Unable to maintain the hover the
aircraft sank, with the landing gear up, on to the
deck . As the co-pilot slowly retarded number 2
engine speed select lever, power was regained,
torque matched and the a ircraft was quickly lifted
into the hover. The landing gear was extended,
brakes and safety pins were applied, and the
aircraft was landed on the deck of the ship
without fu rther incident.
I t has been determined that the aircraft was
2182 pounds above the maxim um permitted
(si ngle-engine) hover weight (out of ground effect)
for the conditions ( 15 250 pounds) when the
winching operation commenced.
The occurrence draws attention to the dangers
of plastic bags and plastic sheeting left insecure in
or around a helicopter landing area.
*
While taxi ing in strong winds, a Cessna 172 was
caught by a gust and fl ipped on its back. The
wind was estimated to have been gusting up to 50
knots. As a general guide, it is risky to taxi a light
aircraft in winds a bove 35 knots .
*
*
Aviation Safety Digest 130 I 19
�l
I
How to make the game tough
A private pilot with probably about 150 hours asked his
employer, who owned a Cessna 182, whether he could
borrow the aircraft over a winter weekend for personal
use. The proposal was to fly from Camden to
Bankstown to carry out some night circuits, and the
next day fly out to Bathurst. The owner agreed to this
proposal, however at Bankstown the pilot submitted an
IFR flight plan from Bankstown to Cooma, and
departed Bankstown at 1738 EST.
The pilot had told various people from time to time
that he was studying for an instrument rating. He
mentioned some training organisations to different
people where it was purported the trainin g was being
conducted, although it was subsequently found that he
was not enrolled with any approved organisation in the
Sydney area. In addition, there was no Department of
Aviation record of the pilot having completed any of
the necessary theory examinations for the issue of an
instrument rating.
The general weather situation between Bankstown
and Cooma at the time of the flight was characterised
by a fresh north-west airstream over the area , with a
cold front lying approximately 50 n autical miles east of
a line Melbourne-Hay. This front moved through
Cooma aro und '0300 EST the next mornin g. Although
there were probably no more than two-eighths of
stratocumulus at Cooma when the Cessna arrived at
1902 , nevertheless there was the possibility of severe
turbulence in the circuit area. The pilot of an a ircraft
which landed at Cooma shortly before the Cessna 182
reported a very strong westerly wind, no significant
cloud, considerable turbulence, a 20 knot windshear on
final approach to runway 36, and generally difficult
conditions. This pilot required power variations on final
ranging from idle to 75 per cent , and experienced
difficulty staying on the centreline. H e noted that it was
a black night without moon , and the only lights were
those associated with the runway.
After the pilot of the Cessna 182 reported in the
circuit area at Cooma for landing on runway 36, he
fa iled to give any subsequent calls , and the Aler t Phase
was declared at 1917. Subsequently the Distress Phase
was declared when the aircraft could not be located.
The aircraft wreckage was found at approximately 0700
the next morning, 5 km south of the Cooma airport.
The aircraft had struck the ground in at least a 50
degree nosedown attitude in a slight left yaw and turn.
The force of the collision with the ground was such that
the distance from the initial point of impact to the point
where the tail came to rest was 60 metres. L arge
components were thrown from the aircraft along the
wreckage trail and the aircraft nosed over before finally
coming to rest. The wreckage was co nsumed by fire
and the cabin area reduced to ashes. T he pilot's body
had been thrown from the aircraft during the b reakup.
Post-mortem reports indicated that the pilot had a.
significant blood alcohol level, to the extent that h is
piloting performance would have been adversely
affected. During inspection of the wreckage six cans of
beer had been found, three of which had bee n opened
by using the 'ring pull'.
The wreckage also contained the pilot's handwritten
summary of the Cooma NDB approach chart , although
whether he had endeavoured to ·complete or had
completed any part of that approach could not be
determined . A thorough tech nical examination of the
wreckage did not reveal any evidence of a d efect or
malfunction which m ight have contributed to the
accident.
The pilot had su bmitted an IFR flight plan without
holding an instr,um ent rating, and whilst heading south
for a retu rn to land on runway 36 at Cooma he would
have had no external visual clues , local turbulence m ay
have been severe, there was co nsiderable crosswind and
ev idently windshear , and to make th ings really tough
the pilot had been consumi ng alcohol. It was likely that
the pilot lost control of the aircraft wh ile m anoeuv ring
to land in conditio ns which m ight have been d emanding
fo r well-qualified and experienced pilots. This pilo t
however stacked the odds so com pletely against h imself
that the outcome may have been predictable from t he
m oment the flight departed Bankstown •
Loose aerosol can causes fire
A Beech 58 on a charter flight from Laverton to
Kalgoorlie was 10 miles from destination when the pilot
no ticed black sm oke entering the cockpit from the base
of the forward b ulkhead. Alternators and unnecessary
equipment were switched off, and after advising
Kalgoorlie FSU of a cabin fire , V H F C omm and the
battery were also swi tched off. The black smoke
thickened r apidly ,and in an effort to make the cockpit
environment bearable the p ilot opened the main cabin
door with the assistance of his sole passenger. T he
battery was switched on prior to gear and flap
extension , FS was advised the aircraft was on a right
base for RW28 , and the battery then switched off again .
Flight Service implemented aerodrome emergency
procedures, but due to the proximity of the aircraft to
the aerodrome the police , fire b rigade, and ambulance
d id not arrive until one minute after the aircraft had
landed. A Flight Service Officer and a local CFI raced
to the Beech as it came to a stop on the runway, with
smoke po uring from the nose locker. They carried fi re
extinguishers from the FSU and were able t o bring the
fire under control within a few minutes. Later the
aircraft was taxied clear of the runway escor ted by the
fire engine.
Investigation
Several loose items were fo und in the nose locker
includ ing two 1 litre cans of oil, and three aerosol cans,
one of which contained paint. The fire had cau sed
damage to electrical wirin g and looms, melted a plastic
heater d uct which carried hot aircon ditioning air to the
cabin from a heater under the locker floor , burnt a
hessian mat on the floor and damaged soundproofing
material. The aircraft skin was not buckled although it
was d iscoloured by smoke inside the locker.
T he flight had experienced light to moderate
turbulence en route to K algoorlie , and an unrestrained
aerosol can containing pa int had fou nd its way into a
recess which h eld the alternator circuit breakers.
20 I Aviation Safety Digest 130
Although normally protected by rubber boots the
a lternator circuit breaker contacts were bridged by the
aerosol can which then heated, ruptured, and caught
fire. T he fire spread rapidly and it was ex tremely
fortunate for both occupants that they were so close to
Kalgoorlie , otherwise the outcome of the in cident may
have been quite different. Circui t breaker protective
devices vary between different Beech 58 models, and it
was not possible to determine the condition of the
protective devices on this particular a ircraft after the
fire had occurred.
The Flight Manual for the Beech 58 requires
alternator and battery switches to be turned off if an
electrical fire is suspected. Opening the pilot's small
side window is recommended for smoke evacuation if
necessary following a fire . Although the intensity of the
smoke was intolerable to the pilot, openin g the main
cabin door would have increased the airflow through
the aircraft and fanned the fire. Again, it was the
proximity of the destinatio n which prevented an
incident develop ing into a serious accident.
Conclusion
Air Navigation Orders P art 33 specifies the conditions
covering the consignment , handling and carriage of
dangerous cargo by air. The cans of o il and aerosol
carr ied in this incident were not only unrestrained but
the aerosol, and possibly the oil, required special
packaging in order to comply with the requirements.
Any pilot who may carry a can of aerosol when fl ying
should take considerable heed from this incident, since
it could easily have ended in disaster. Any cleaning
agents are best left back a t base and aerosol can s in
particular should not be carried arou nd in the off
chance that they might be needed. C o mplacency is
dangerou s, and pilots should always be on the lookout
fo r any personal item or piece of cargo which might be
potentially dangerous •
Aviation Safety Digest 130 I 21
�'i<eadut
~
4nimal acts
Dangerous fumes
A Cessna 402 pilot's experience with a leaking outboard motor illustrated the danger posed by toxic
fumes in a confined area.
11
After a flight to an island airstrip the pilot had to lift an
outboard motor off some luggage in the nose baggage
locker. Although the motor was new it obviously had
been tested before shipment , as some fuel had dripped
onto the floor. This spillage was cleaned up, and the
pilot then confirmed that the motor's fuel tank was
empty. With the matter seemingly reso lved, the flight
was continued.
Some slight odour was apparent after takeoff, but this
was not considered significant. Another stopover was
made and , again, on the subsequent leg, fumes were
noticed. They seemed to be originating from the left
side of the nose locker, where the outboard motor was
still located . Both the pilot and the passenge r sitting in
the co-pilot 's seat were aware of the fumes. This
particular leg took an hour, during which time the
pilot 's stomach began to feel empt y: he attributed this
to hunger. Shortly afterwards he started to feel lightheaded, an d again decided that hunger was the cause .
T hat sector also concluded at an island strip, where
some time was spent outside th e aircraft. Takeoff was
then made for a further leg.
About 25 minut es afte1· departure the pilot tried to
cat something but found he had no appetite . He also
again began to experience a feeling of light headedness, although this time it was more
pronounced . At this stage he began to suspect that he
may have been experiencing mild food poisoning from
the previous evening. He was not too concerned, as he
fell he was in complete command of the situation.
H owever, several minutes later he began 10 vomit . In
view of his condition , the pilot wisely decided to engage
the autopilot. Having been sick, he almost immediately
felt better and assumed that all hi s problems were gone .
Th is was not the case, for , when he arrived in the
circuit area , the manoeuvring for landing again made
him ill: he was particularly aware of feeling weak a nd
drained.
The 'drained' feeling persisted after landin g so the
pilot drank some staminade , which seemed to improve
his condition. About 20 min utes later he was read y to
depart again, but, ju.sl aft er he had finished checking
the security of a ll baggage lockers, he suddenly became
ill and once more started vomiting . The drained feeling
returned and he also began ' to experience dizziness.
At that stage he decided he should not fl y aga in , but
instead shou ld stay overnight where he was, and seek
m edical attention.
T reatme nt was administered by a nurse, wh o put the
pilot on oxygen for one hour and advised him to rest all
evening . Oxygen was made available for use if
necessary durin g the night.
Follow-up action
Conce rn ed by the incident and app reciatin g that its
consequen ces cou ld have been worse, the pilot too k
22 I Aviation Safety Digest 130
some trouble to pass on to o thers what had happened .
DetaiJs were broadcast to other operators by R / T , while
a comprehensive report , on which this art icle was
based, was sent to the Bureau of Air Safety
Investigation.
Medical advice
Generally the hazards of petrol vapour arc rel at ively
slight , with the exception of their flammability. It
would be for the latter reason that the presence of such
fuels in open con tainers and/ or with inadequate
ventilation would usuall y be strongly d iscouraged.
The inhalation of petrol vapour docs .have a mild
anaesthetic action . Concentrations required to have th is
anaesthetic effect a1·e generally quite h igh; however, at
lower concentrations a varie ty of effects may be n oticed.
These include giddiness, flushing of the face , nausea ,
loss of appetite and inco-ordination. I n extreme cases
th is can progress to disorientation , convulsions a nd
coma .
While these effects o f petrol vapo ur inhal at ion are
usuall y mild at sea level, they become of much greate r
significance at altitude. T he petrol mist acts by
displacing oxygen in the a ir , thus wor senin g th e
expected pilot hypoxia a t a given al titude .
If petrol vapo ur is not iced in fligh t, all efforts should
be made to in crease ventilation and u se an oxygen
mask, if a vailable.
Treatment o f mild cases consists of removal from the
exposure area to fresh air. More severe cases m ay
require oxygen therapy or assisted respirat ion •
Wishful thinking
When a pilot makes a decision to continue in
marginal conditions, it may be that he is
indulging in a little wishful thinking .
It is one thing to make a decision based on local
knowledge or experience - it is an entirely
different matter to press on in m arginal
conditions, believing that things always get better.
Consider a local fog with a forecast for improved
cond itions. It would be downright foo lish to coun t
on the fog clearing to th e extent of being
committed to land on a rrival and having no
options. Or consider the occasion when there is an
excessive rpm drop on runu p - it would be just
as foolish to assume that it is plug-fouling and
that it will clear on takeoff.
Whenever we say ' She'll be right , mate' , we
are exposed to u nnecessary risk. A good gambler
not only considers the odds b ut he also refuses to
bet more than he can a fford to lose.
In aviation the stakes are too high - wishful
thinking is not often survivable •
In a representat ive 2 V2 year period, there were 57
reported occurrences of animals obstructing landing
areas in Australia: doubtless there were other
instances which were not reported. These selfpropelled obstruct ions ranged from cattle to sheep,
dogs to foxes, and emus to kangaroos. They were
democratic in the ir cho ice of landing areas, p icking
on lice nsed a erodromes and i\LAs without apparent
favour.
In those 57 occurrences, da ma ge to aircraft varied
from ni l for inciden ts in which a go-around or
aborted takeoff was successfu lly executed, to
substan tial when either collision with the animal
occurred or allemptcd avoi ding action resulted in an
acci dent.
Obviously, every effort should be made to prevent
this problem.
ALAs
The responsibili ty for ensuring that an ALA is clear
rests squarely with the pilot-in -command. The Visu al
Flight Guide (VFG) states :
The pilot in command shall not land or take off unless
persons, animals, vessels and other objects are clear of
the runway strip or channel and clear of the aircraft on
the ground or water when an engine is operating.
It is also important to note that pilots should contact
the ' own er, occu p ier or controlling authority' before
using an ALA, and it clearly makes sense that the
likelihood of animals - especially livestock - being
on the strip should be checked at that stage .
Notw ithstanding the foregoing, owners of ALAs are
strongly encouraged to take all reasonable steps to
keep animals off their strips .
Licensed aerodromes
A erodrome licensees are responsible for, inter alia,
ensuring that no 'vehicle, person or th ing en ters or
remains upon an y part of the aerodrome in
circumstances in which the safety of an y aircraft or
its passengers or crew is likely to be imperilled'. As
there have been a number of incidents lately in
wh ich livestock have gained access to movement
areas, it would seem that some aero drome
operators/owners arc not complying with their
C onditions of L icence.
Conclusion
All aerodrome licensees must be aware of their
responsibilities and the possible consequences of
neglect. The dictates of good airmanship also
demand that a pilot checks that any movement area
is clear before it is used, regardless of whether he is
at a n in te rnational airport or an ALA •
Avia tion Safety Digest 130 I 23
�
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�Contents
Editorial
3 Editorial
4 Accidents involving private pilots in Australia
Key results from a recent study by the Bureau of Air Safety
Investigation
5 Planning, checking, replanning
6 Accumulative stress
(human)
8 A review of Australian helicopter accidents
1974-83
13 Looking after your passengers
Aviation Safety Digest is prepared by the Department of Aviation and
is published by the Australian Governmen t Publishing Service. It is
distributed free of charge to Australian licence holders (except student
pilots), registered aircraft owners and certain othef' persons and
organisations having an operational interest in Australian civil aviation.
Unless otherwise noted, articles in the publication are based on
Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
The Publications Distribution Officer
Department of Aviation
P.O. Box 1839Q, Melbourne, Vic. 3001
15 Lap-sash belts
Aviation Safety Digest is also available on subscription from the
16 Power towing
Australian Government Publishing Service. Inquiries 'and notifications
of change of address should be directed to:
18 Human factors and aircraft
in~truments
20 Low cloud base, rising terrain
21 Overstressed
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601
(airframe)
22 Asleep on the job
(reader contribution)
23 The herd strikes back
Subscriptions may also be lodged at AGPS Bookshops in the capital
cities.
Reader contributions and correspondence on articles should be
addressed to:
First Assistant Secretary
Flight Standards Division
Department of Aviation
P.O. Box 367
Canberra City, A.C.T. 2601
© Commonwealth of Australia 1986
ISSN 0045-1207
R841403(5) Cat. No. 85 1958 4
Cover
The artwork on the front cover of this issue is based on a
printout from the Bureau of Air Safety Investigation's computer
graphics system. The scene portrayed is that of an aircraft
involved in an actual incident whilst carrying out a non-precision
instrument approach to an Australian airport close to the coast.
However, the image of an IAI Westwind used in the graphics is
for illustrative purposes only and the incident portrayed did not
involve this type.
The reconstructed flight and ground paths were derived from
the aircraft's flight data recorder. The coastline, the airport, the
letdown profile and the aircraft's ground track, as well as the
aircraft model, are animated and to the viewer it appears as if
you are in a following aircraft. The view can be changed at will
from that shown to vi rtually any view which best suits the
purpose of the investigation. If more than one aircraft is in the
airspace it will be seen in its relative position. The display can
be speeded up, slowed, stopped or run in reverse. Terrain data is
derived from maps of the area in question.
The graphics system can also be used to simultaneously
display flight and navigation instrument readings throughout the
approach, so that the instruments fly the profile of the aircraft
based on the recorded flight data.
For the technically minded the computer graphics system is an
Evans and Sutherland PS300 high performance interactive
graphics computer with 3Mb of memory.
2 I Aviation Safety Digest 129
Printed by Finepress Offset Printing Pty Ltd
35 Fitzpatrick St, Revesby, N.S.W. 2212
There is now widespread recognition within the aviation community that human factors,
in one way or another, are the most significant contributions to breakdowns in aviation
safety.
Seeking to maintain and, where possible, improve upon our existing safety record is a
responsibility we must all share regardless of our position or standing within that
community.
In order to adequately discharge that responsibility, it is important for all of us to have
not only a knowledge of the rules and procedures and the rationale for their existence
but also of the need for all things associated with aviation to be done meticulously.
This is fundamental to the safe and orderly conduct of operations and is the
cornerstone upon which a sound sense of airmanship can be based. Most experienced
pilots, maintenance staff and Air Traffic Services personnel already have this knowledge
and the qualities that stem from it. Others, perhaps less experienced, must gain it if
they are to accept their share of the responsibility.
The Department is now moving to put additional emphasis on programs to address
the human elements of aviation safety. The Flight Standards Division of the Department,
which is charged with the responsibility of seeking to ensure safety in civil aviation , has
now taken the initiative to press home the message about the need for all of us to
continue to be very safety conscious. As part of this initiative, the editi ng and production
of the Aviation Safety Digest will in future be undertaken by Flight Standards as part of
its developing safety promotion activities.
The Digest has proven to be a very popular publication . While its change of
'management' will not in itially lead to significant changes in style, form at or content, we
will , in time, endeavour to improve its usefulness by including more general information
on why we should practise pilot and aircraft operating procedures as they are
prescribed, why airworthiness and maintenance procedures need to be as they are and
why we maintain the medical standards that we do.
In future editions I will be commenting upon the 'immunity' of pilots from punitive
action following calls to Air Traffic Services units for assistance and will be seeking
comments from readers on how the publication may be improved. However, the editorial
policy will be to concentrate on safety education and promotion of the human factors
safety message.
Qerry O'Day)
First Assistant Secretary
Flight Standards Division
Aviation Safety Digest 1 2 9 I 3
�Accidents involving private pilots in
Australia
Key results from a recent study by the Bureau of Air Safety Investigation
During th e years 1983, 1984 and 1985 the number of
accidents in General Aviation fell from 263 , to 220 a nd
209 respectively. Over the five-year period prior to 1983
the a nnual average had been 239 accidents. These
statistics include a ll GA accidents regardless of the
category of pilot licence held, although gliding accide nts
have been excluded. While the large number of GA
accidents in 1983 could have several explana tions,
nevertheless th ere has been a worthwhile decline since
then from the five-year average of 239 .
Accidents involving PPL holders which are included in
these same statistics were 123, 81 and 69 , so that the
decline in t he number of all GA accidents is a lmost
entirely explained by the fall in the number of accidents
involving PPL holders. Rather than provide priva te pilo ts
with a large amount of statistical information on the
subject , the Bureau of Air Safety Investigation has
summarised results of the study for the benefit of PPL
holders, fl ying schools and owners of private a ircraft.
The question of whether there has been a mea ningful
decline in the number of accidents or whether the decl ine
is purely a ra ndom one has been set aside for the
purposes of this article. What appears to be particularly
significant however, is that there has been a decline in
th e proportion of pilot to tota l factors in accidents
involving private pilots. Accident factors are assigned
from several different categories which cover pilots,
weather , powerplants, systems, airframes, terrain and
several others. In 1983 , pilot factors assigned to accide nts
involving private pilots represented 30 per cent of t he
total of a ll factors assigned to these accidents. In 1984
the proportion was 23 per cent and in 1985 21 per cent.
In hig hlighting this favo urable trend , it must a lso be
stressed tha t during the past eight years only 19 per cent
of accidents involving private pilots failed to attract any
pilot factors a t a ll wh en the probable causes were being
determined . BASI then examined the p attern of pilot
factors assigned during the five-year period prior to 1983
and compared this with the years 1983, 1984 and 1985
taken individua lly.
It became apparent that there were thirteen pilot
factors from a total inventory of several hundred which
accounted for two-thirds of all instances in whi'ch pilot
factors were assigned to PPL accidents. T hese thirteen
factors are listed below in order of relative importance
according to the number of occasions each was assigned
over several years:
• Inadequate pre-flight preparation and/ or p lan ning
• Improper inflig ht decisions or inflight planning
• Improper landing flare
• Did not obtain or maintain fl ying speed
• Selected unsuitable area for takeoff or landing
• Lack of familiarity with a ircraft
• Attempted operation beyond experience/ a bilities
• Diverted attention from operation of aircraft
• Improper recovery from bounced landing
4 1 Aviation Safety Digest 129
• Did not initiate go-around/ missed approach/
overshoot
• Improper compensation fo r wi nd conditions
• Improper operation of powerplant controls
• De layed initiating go-around .
Since 1983 there h as been a considerable improvement
in the following areas, signified by a d ecline in the
number of occasions on which the factor was assigned :
Operational decisions
• Improper inflight decisions or inflig ht planning
• Selected unsuitable area for ta keoff or landing
• Did not initiate go-around/ missed approach/
overshoot
Handling techniques
• Did not obtain or maintain fl ying speed
• Improper compensation for wind conditions
Other
• Lack of familiarity with aircraft
A much weaker improvement occurred amongst the
fo llowing factors, a lthoug h it is difficu lt to know whe the r
the small changes involved are suffi ciently significant to
reveal an underlying tre nd:
Handling techniques
• Im proper landing flare
• Improper recovery from bounced la nding
Other
• Attempted operation beyond ex perience/ a bilities
Li ttle or no change occurred in t he case of the
following three factors:
• Diverted attention from operation of a ircraft
• Improper operation of powerpla nt controls
• Delayed initiating go-around
T he outstanding feature of the resu lts of the study
however was that it is apparent little impact is being
made in the area of the most importa nt factor of all:
INADEQUATE PRE-FLIGHT PREPARATION
,,,_
'PT .I.
"1T~r"
There were several possible influences at work in the
areas where improvement appears to have occurred. For
instance the biennial flight review may have had some
effect by 1984 f ollowing its introduction in September
1982, while the wider use of pilot safety seminars and
higher levels of saf ety education throughout the industry
generally must be important considerations.
It is clear though that Private Pilot Lz'cence holders are
in a key position to make substantial cont ributions
towards reducing the number of accidents, through
greatly improved pre-flight preparation and planning.
This area includes the study of weat her fo recasts,
selection of route and altit ude, method of navigation,
allowance for alternative courses of actz'on, calculation of
fuel reserves, evaluation of Notams, study of
maint enance releases, pre-flig ht inspection of aircraft,
fuellz"ng, evaluation of departure aerodrome surface and
weather conditions and many others. Pre-flight
preparation and planning needs to be completed in an
unhurried fashion by pilots who are properly rested,
and who feel physically and mentally alert for the
proposed operation.
The improvement in some areas will require
continuous reinforcement through a disczphned approach
to all aspects offlying operations if the trends are to
continue. Pi'lots of all licence categories could give
careful consideration to the broad findings of this
review, while flying instructors conducting ab initio
training and biennial flight reviews should find the
information particularly useful. Without in any way
detracting from established syllabuses and methods of
training, it is repeated that these thirteen accident factors
together account for two-thirds of all the instances in
which pilot factors were assigned to accidents involving
private pilots •
Planning, checking, replanning
The process of planning, checking and replanning is one
that is never completed in piloting . At all stages of a flight
a pilot possesses information relating to any one of a
number of operational considerations - navigation,
aircraft performance, fuel consumption and so on which must be continually reviewed and updated; and as
a result of that process , the pilot either verifies or
amends existing decisions. This latter action might range
from a minor heading change or an amendment to ETA, to
a decision to divert.
In the investigation summary which follows, the pilot
involved failed both to plan properly on the ground and
check on operational data in the air. Consequently, he
was not able to replan inflight to adjust for prevailing
conditions, and ran out of fuel about 8 miles from his
destination .
Fuel exhaustion
A PPL holder with about 800 hours flight experience and
a Class Four rating was asked to ferry a Grumman
American AAS from N.S.W. to Perth. After three days
the pilot had reached Eucla in W.A. On the morning of
the fourth day he refuelled at Eucla and flew to Forrest,
where the Grumman was again refuelled, this time for the
leg to Kalgoorlie. The pilot assessed that he would not
be able to reach Kalgoorlie without a further refuelling ,
so he took a 5-gallon jerry can of Avgas with him,
intending to land at Zanthus to add this fuel. He also took
on board at Forrest a passenger who urgently needed to
get to Kalgoorlie .
The fuel top-up was completed at Zanthus as planned.
However, about 3 0 nm east of Kalgoorlie the AAS's
starboard fuel tank ran dry and, for the first time, the pilot
began to feel some anxiety about the fuel state . This
anxiety was well founded, for about 8 nm east of
Kalgoorlie the aircraft's engine stopped , and the pilot
was forced to make an emergency landing on the road
he had been following. This was done successfully,
without damage either to occupants or machine.
A casual attitude
The pilot's approach to planning and flying this long trip
can only be described as off-hand. As was his 'normal
practice', he had not obtained any weather briefings or
Notams, nor submitted flight plans. Further, during the
first three days of the trip, no attempt was made to
determine actual fuel usage , as compared to the book
figures.
For the Eucla-Forrest-Kalgoorlie flight a written flight
plan was not prepared . A mental 'plan' of the
Forrest- Kalgoorlie leg was done, with the pilot selecting
his own en route wind, which he decided would be
abeam at 20 knots, i.e. no allowance was made for any
headw ind or tailwind component.
It seems that, once airborne, little effort was made to
exercise operational management over events: although
the basic requirement for track-keeping was observed by
following prominent features (in itself, a sound practice).
little if any attention was paid to fundamental navigational
techniques and applying the information those techniques
produce . There was no disciplined monitoring of fuel
usage, w hile the pilot also seemed prepared to sit back
and let checkpoints and destinations appear.
As it happens , the Grumman had a carburettor
unserviceability which caused a higher than expected
fuel flow; while aircraft performance was below that
detailed in the pilots operating handbook, for both the
climb and cruise. Obviously , these factors considerably
reduced the AAS's range and endurance.
Also working against the pilot was his lack of thorough
flight planning. The area forecast predicted an abeam
wind for half of the Eucla-Kalgoorlie flight and a 1 0- 12
knot headwind component for the remainder. In fact the
actual winds (determined later from meteorological
balloon data) were more westerly than forecast , thus
giving a greater headwind component.
In combination with the pilot's failure to plan properly
on the ground, check inflight, and then replan on the
basis of any new information or different performance
data, the unexpected - and, equally as dangerous undetected increase in fuel usage exposed him to the
deathly hush that no pilot wishes to experience.
Comment
There is no formal requirement for flight notification or
weather briefing for the type of operation the pilot
planned to undertake, although the Visual Flight Guide
does state that for flights where no forecast is required ,
the pilot ·... must study all available weather reports to
form an appreciation of the conditions you are likely to
meet' . All that was needed here was a reverse charge
call to the nearest Flight Service Unit. The opportunity
also was not taken during the preceding three days to
record fuel added , monitor the gauges carefully in flight,
and dip the tanks after landing, and so calculate an
accurate fuel flow.
Finally, by not observing the plan/check/replan cycle,
the pilot was not able to control events but, rather, just
let things happen •
Aviation Safety Digest 1 2 9 I 5
�Accumulative stress
approach, but he did remem ber concentrating very h a rd
on his landing. Unfortunately this proved to be a t the
expense of other essential actions. T he culmin ation was
an extremely hazardous landing, not only for himself
but also for all on board the SAL aircraft.
Discussion
It might be easy to say, but it's true: a fl ight is not
finished until the aircraft is tied do wn, signed off and so
on ...
Given this pilot's inexperience and the p roblems he
encountered, the anxiety he felt - the stress which
gradually accumulated - is entirely underst andable.
However, having sensibly d ealt wit h th e p roblems, the
effects of the stress he had been under - aga in
understandably - did n ot entirely d issipate . T hus, still
a bit panicky, he found he h a d to make one 'last effort'
i.e . join the circuit and land safely. This, of course, can
be one of the h ighest workload, m ost demanding
sequences a pilot h as to complete. Regardless of what
may have happened beforehand, standard procedu res
must be observed and sound judgment exercised.
About five miles east of an uncontrolled aerodrom e
servin g a large country centre, th e crew of a
Supplementary Airline (SAL) aircraft p assed a PA28,
apparently bound for the same destination.
Up on arrival the SAL aircraft joined crosswind, flew a
standard circuit and transmitted the usual radio calls
before completing a routine landing. After rolling
through to the end of the runway the pilot turned and
started to backtrack - only to be confronted by the
Cherokee which was on a very short final approach.
The SAL pilot stopped and flashed his aircraft's
landing lights, but to no avail. T h e PA28 continued
with the landing and then turned off the runway before
reaching the other aircr aft.
An independent observer later stated that the
Cherokee h ad not overflown the field but, instead, had
joined the circuit on final approach.
When th e incident was..discussed with the Cherokee
pilot, it became apparent that he was uncertain how he
had entered the circuit. It also becam e apparent that his
dangerous landing was, to a large extent , a result of
accumulated inflight stress which h ad caused his overall
p erformance level to deteriorate
A solo navex
The PA28 pilot h eld a PPL with area restrictions: the
flight during which the incident occurred was his
seventh solo navex. As it happens, this exercise had b een
very difficult, probably even traumatic at times.
Initially the pilot had been able to cruise at 3000 feet
6 I Aviation Safety Digest 12 9
but a lowering cloud base forced him to descend to 1500
feet. Conditions were such that a t one stage he came
close to carrying out a 180 degree tum to 'get out', but
the cloud h ad thinned and he h ad emerged into the
clear. However, by then h e was off track and could not
recognise any ground features. He decided to maintain
heading until he could get a fix, and finally came across
a large town h e recognised, although it was on the
opposite side of his planned track.
Sensibly, the pilot orbited over the town for several
minutes to collect his thoughts and give himself time to
re-organise the navex. Eventually he set heading again
and some time later was very relieved to see his
destination.
A recap on the events to date will be useful here in
assessing the pilot's probable state of mind when he
entered the destination aerodrome's circuit. He was
inexperienced, h ad been on a solo navex and h ad
become lost en route. This had been very disturbing for
him. Further, from reviewing th e actual weather
conditions l ater , it was possible th at some of the flight
may be have been conducted in conditions less than
VMC. This would have been a source of more pressure.
To his credit, the pilot - through common sense and
keeping his head - finally extricated himself from his
stressful circumstances. H e was understandably relieved
to arrive at his destination.
T h e Ch erokee pilot later stated th at h e had been
upset by the navex problem s, and when he reached his
destination he was feeling a bit p anicky. In that state of
mind he was unsure of exactly how he flew his
Dealing with stress
In the words of som e unknown fellow human being:
'When you'r e up to your b utt in crocodiles it's hard to
remember that your initi al task was to drain the swamp'.
The above quotation is not only somewhat amusing, but
also reasonably accurate. One of the m ost com mon and
predictable behavioural results of the stress reaction that
we call fear, or panic or an xiety is a narrowing of our
focus of at!:ention, sometim es called channellised
attention.
A pilot experiencing cha nn ellised attention may fin d
him or herself monitoring attitu de so inten tly that they
stop monitoring airsp eed and / or altitude. This type of
reaction often happens when V FR p ilots find themselves
in IMC conditions.
As the pilot of the PA28 sta ted , when he reached h is
destination he was feeling a bit panicky. H e did not see
the aircraft on the runway, but he did remember
concentrating very h ard on his landing.
T he question is: h ow can we recognise and overcome
these types of stress-induced behaviours?
Apart from continuing one's education through
articles such as this and fin ding out what type of
behavioural patterns can result from specific
psychological rea ctions, the only effective and portable
method for recognising and dealing with these types of
p roblems is by learning to pay more attention to
yourself.
It is generally true th at m ost pilots are acutely aware
of the condition of their aircraft. Not only ar'e the
instruments a source of informa tion which tells a pilot
how th e aircraft is performing, but most pilots a re also
aware of whether or not the aircraft 'feels' right and
whether it 'sounds' right .
Perhaps sur prisingly most pilots do not seem to p ay as
much a ttention to their own state as they do to the state
of their aircraft. Yet we know that in the majority of
occurrences the wea k link in the chain is often the pilot,
not the aircraft. We also know subjectively from our
experiences as hu m an beings in h abiting plan et Earth
that the way we m ake decisions and the types of
decisions we make are quite different if we are angry
an d aggressive as opposed to b eing happy and calm.
Anger is one of the psychological states that we tend
to be aware of, perhaps beca use we experience anger
more often than other psychological states of mind
bec ause anger is usua lly directed at some specific event
or person.
W ith less com mmon psychological st ates such as fear,
particularly if the fear is n on-specific and not entirely
and im mediately tied to some specific person or event,
we tend to be less aware of the effect th at su ch a
psych ological state has on the way we p rocess
information.
If as a pilot you find yourself in a situ ation where you
are afraid or anxious, take the time to say consciously to
yourself 'I am afraid' or ' I am anxious'. Take th e time to
recognise fully the psychological state you are in and
then simply ask yourself: 'What am I doing or not doing
now th at I would or would not be doing if I were not
afraid or a nxious?'
Summary
In summary, clearly and consciously acknowledge your
em otional reaction. Recognise the potential for a
deterioration in your performance as a resul t of your
emotional sta te. Ask yourself, 'What are the standard
p rocedures for this situ ation ?' an d force yourself to
follow each of these procedu res •
In brief
A PA 28-R201 (retractab le) landed wheels up on a
country airfield at the conclusion of a practice forced
landing . T wo pilots were o n board, one under
training and the other as instructor.
Most of the trainee's flying had been in fixed -gear
aircraft, and in this instance , d u ring the forcedlanding emergency d r ills, h e followed his usual checks
- which did not include the un dercarriage. T he
instructor seems to have been concentrating on the
immediate exercise at the expense of vital actions.
*
*
*
T he alternator drive belt on a Cessna 2 10 failed,
causing loss of output. With a low battery voltage, the
aircraft's land ing gear motor was incapable of fu lly
extending the gear and continued to run at a reduced
speed. Event ually the motor overheated a nd burned
out.
Airworthiness engineers recommended that landing
gear motors be examined for d amage if the gear has
been cycled on low voltage.
*
A viation Safety Digest 129 I 7
�A review of Australian helicopter
accidents 1974-83
Table I : 1974-83 (incl.)
Accidents by
phase offlight
All
helicopters
%
%
G ROUND
engine(s) operating
4.3
1.7
T AXI
to takeoff
from la nd ing
othe r
1. 7
1.3
0.4 (3 .4)
2.5
2.9
0.0 (5 .4)
TAKEOFF
run
initial climb
discontinued
other
0 .9
10. 7
0 .4
0.4 (12.4)
6.9
9.8
2.0
0.0 ( 18.7)
F LIGHT
climb
cruise
descent
aeroba tics
agriculture
low flying
holding/ hovering
0.4
16.2
6.0
0.4
3.4
26.5
6.0 (58 .9)
2.4
8.9
2.0
0.1
6.4
3.9
n/ a (23. 7)
2 .6
2 .6
14.1
1. 7 (21.0)
100.0
8.2
22. 7
16.5
3.1 (50 .5)
100.0
Delivery of replacement propeller for Indonesian Patrol boat, Thursday Island wharf. Photograph by Mr John Devine.
L AN IJINC
a pproach
level-off, touch-down
roll
go-around
wing aircraft. The majority of helicopter accidents in the
low-flying ca tegory occurred during aerial mustering.
These helicopter statistics reflect the fact that a
considerable proportion of helicopter operations are
conducted in close proximity to the ground. T he position
is reversed with the landing phase, helicopters
experiencing 21 .0 per cent of accidents in this area
compared with 50.5 per cent for fixed-wing aircraft. This
substantial difference is principa lly due to the high level
of fixed-wing aircraft accidents in the level -off and
touch-down manoeuvre, where the proportion was
a pproximately 10 times higher than for helicopters.
All fixed· wing
single-engine
aircraft
Acc ident rates
Accident rates are measured in terms of the number of
a ccidents per 100 OOO flying hours. As total hours
increase it is found that the accident rate normally
declines. Graph 1 compares total helicopter hours flown
and the accident rate. The dotted line through 1978 is
drawn to separate two periods with different
characteristics. D uring the early half of the period, total
hours and accident rates tended to move in similar
directions, which is the opposite to that normally
expected. This may have been partly due to a
considerable amount of technological change wh ich
occurred in the helicopter segment of the industry during
the early and late 1970s. R ises or falls in helicopter flying
activity involving new equipment may have been
correlated with rises and falls in the number of accidents,
until sufficient learning had occurred for the appearance
of 'normal' trends after 1978. During this time, for
example, many helicopters were refitted wit h more
generally not ·applicable to helicop ters. However, 58.9
per cent of helicopter accidents occurred during the
segments listed under the flight phase compared with
23. 7 per cent fo r fi xed-wing aircraft. If the flight phase is
confined to climb , cruise and descent , helicopters were
still hig her than fi xed -wing aircraft with a proportion of
22.6 per cent com pared with 13.3 per cent. Agricultural
and low-flying accide nts accounted for 29.9 per cent of
t he helicop ter total against 10.3 per cent for the fixed-
15 0
The Bureau of Air Safety Investigation has recently
received requests for an overview of past helicopter
accidents, and the 10-year period 1974-83 has been
selected for this purpose. The number of registered
helicopters more than tripled during this time and now
exceeds 300. When helicopters were first introduced
during the 1950s they were relatively small, carried little
payload, tended to be underpowered and were soon
involved in a number of accidents. Until the 1970s
helicopter accident statistics were amalgamated with
those for fixed-wing aircraft, mainly due to their small
numbers. From 1973 onwards new and separate
statistical series were developed for helicopters and these
records form the basis for this review.
Unique characteristics of the helicopter make it
adaptable to a wide variety of environments which
frequently take it into difficult or unusual situations.
Helicopter operations cover a wide range of activities
including the following: air taxi, charter, cattle
mustering, patrol {pipelines and powerlines), agriculture,
road traffic control, National Parks surveillance , water
sampling (creeks and rivers) , fire-fighting, news media,
geological survey, Reg. 203 services, search and rescue,
evacuation, police, oil rig support, supply {mountain and
8 I Aviation Safety Digest 129
snow country) , industrial sling-loading, training .
Although statistics for the number of takeoffs and
landings per pilot per day are not collected, cycles of up
to 60 per day are known to occur. The inherent
aerodynamic instability of helicopters means that most,
particularly early models such as the Bell 4 7, cannot be
trimmed to various phases of flight as can fixed-wing
aircraft, and piloting tends to be a full- time task.
Helicopter autopilots are very rare and their use is largely
confined to twin-engine types and IFR operations,
consequently the bulk of operations involve continuous
hand flying.
Accidents by phase of flight
Table 1 shows the distribution of helicopter accidents
amongst 19 different phases and types of opera tion, and
compares them with similar information for all fixedwing (single-engine) aircraft accidents.
There were 234 helicopter accidents during the ten·
year period, and 1779 accidents in the fixed-wing (single·
engine) aircraft group.
In the takeoff phase the results a re broadly
comparable to one a no ther although the takeoff run is
6 0 .....
(/)
0
::::i
0
s.
0
..r:
~ 100
0
80
0
;;::::
I',
~
::::i
0
I
..r:
.....
0
'
........
'
...
I
a.
I
0
I
.~
I
Q)
(ii
I
I
2
..r:
I
50
Q)
'
I
I
Accident rate
I
'
GRAPH 1
... ""
c
"O
I
;§
0
1 9 74
4 0 f.l
... "
·c:;
''
(.)
ctl
.....
' ' '-
_/
_...
- - -- -
2
a.
20
I
0
.~
Q)
I
I
0
75
76
77
78
79
80
81
82
83
Year
Aviation Safety Digest 129 I 9
�powerful engines, several new types were introduced,
while others were phased out. Some Hughes 369 series
and many Bell 206 helicopters had Allison C20 engines
substituted for the original Cl8 engines. Fleet changes
also occurred as operators began to show preference for
new Bell 206 helicopters, while earlier models were
simultaneously being re-engined witQ. the C20 engine.
The advent of turbine-powered helicopters was another
technological change which introduced new and different
problems. For instance, sustained operation of turbinepowered helicopters in outback desert conditions caused
compressor wear through dust ingestion. In turn this
reduced compressor efficiency and therefore power
output, although the extent of the problem was not
recognised for some time. However, it is not possible to
be precise on the extent to which technological change
affected helicopter statistics prior to 1978.
From 1978 onwards the common relationship between
accident rate and total hours flown emerges. Growing
technical sophistication of helicopters along with
improved knowledge and skill amongst ground and flight
crews probably contributed to this gradual change. Also,
statistical trends would have become clearer as the
number of helicopters increased. The altered trends from
1978 are discussed further in the following section.
Assigned factors
Table 2 shows the proportion of helicopter accident
factors which were assigned to different categories and
compares them with similar information for all
private/ business fixed-wing single-engine aircraft
accidents. This further refinement of the presentation
was deliberately selected in order to highlight differences
between rotary and fixed-wing aircraft accidents, rather
than to draw parallels. Only one accident to a multiengine helicopter is included in the data. The
comparison is therefore between single-engine h elicopter
accidents and single-engine fixed-wing aircraft accidents.
Arranging the informa tion in this way also makes a
deliberate comparison between two essentially different
pilot groups. 90. 7 per cent of the helicopter pilots
involved in these accidents held Commercial or Senior
Commercial Helicopter Pilot Licences, while only 15 per
cent of the private/ business pilots held equivalent
licen ces. The total number of helicopter accidents
covered by the table was again 234, while the total for
the single-engine group was 1113.
Table 2: 1974-83 (ind.)
Assigned
accident factors
by category
H elicop ters
Pilot
Weather
Powerplant
Other systems
Terrain conditions, off aerodrome
Miscellaneous
Aerodrome/ landing area
Other personnel
Airframe
10 I Aviation Safety Digest 129
Privlbusiness
fixed-wing
single-engine
aircraft
3
3
53.7
4.8
8.9
8.4
9.8
3.0
0.6
9.4
1.4
60 .7
8.0
3.9
1.5
4 .3
2.8
3.3
4 .5
11.4
100.0
100.0
Pilot factors
The proportion of pilot factors in helicopter accidents
during the ten-year period was 53. 7 per cent compared
with 60. 7 per cent for fixed-wing aircraft. However,
accidents involving powerplant and other systems factors
for helicopters totalled 17.3 per cent against 5 .4 per cent
for fixed-wing aircraft. On the other hand, airframe
factors constituted only 1. 4 per cent of the total
helicopter factors assigned, compared with 11 per cent
for the fixed-wing aircraft. The helicopter statistics were
then re-examined in two equal periods, 1974-78 and
1979-83, to see whether there was any significant
difference in the pattern of assigned factors before and
after 1978. However, there were only minor differences
between the two periods.
The 10 most important pilot factors out of a total of
39 assigned to helicopter accidents are listed below, in
descending order of importance:
1. Attempted operation with known equipment
deficiency
2. Inadequate pre-flight preparation and/ or planning
3. Improper operation of primary flight controls
4. Improper level-off during landing
5. Did not see or avoid objects or obstructions
6. Did not maintain adequate rotor rpm
7. Diverted attention from operation of air-craft
8. Selected unsuitable area for takeoff or landing
9. Misjudged horizontal/vertical obstacle clearance
10. Inadequate supervision of flight with multi-crew
These 10 factors accounted for 64 per cent of all the
helicopter pilot factors identified in accident
investigations over the 10-year period 1974-83 (incl.).
Similar information for the fixed-wing group is given
below a nd it is evident that the two main helicopter pilot
factors are also common there , i.e. 'attempted operation
with known equipment deficiency' and 'inadequate preflight preparation and/ or planning' . Except for these two
factors, the order of importance of the remaining eight
factors either tend to diverge between the two groups or
are different factors altogether.
Diverted attention from operation of a ircraft
Inadequate pre-flight preparation and/ or
planning
1. Attempted operation with known equipment
deficiencies
2. Inadequate pre-flight preparation and/ or
planning
3. Did not see or avoid objects or obstructions
) equal
Improper operation of primary flight controls )
Pilot fatigue
T he question of fatigue is sometimes raised by the
helicopter pilot group in relation to accidents. This
concern may be associated with the rela tively high
number of daily takeoffs and landings performed by
many helicopter pilots. Certain human factors relating to
pilot performance, such as fatigue, a re assigned to
accidents where appropriate. Computer data however
revealed only two accidents 1974-83 where pilo t fatigue
was assigned as a factor . By coincidence both of these
involved the Bell 4 7 m odel. T he possibility of pilot
fatigue was also mentioned in a number of accident
reports , a lthough it was considered there was insufficient
evidence for fatigue to be assigned as a separate factor in
those instances. Overseas studies have shown that the
importance of pilot fa tigue as a possible factor in
The comp arison between two essentially different pilot
groups was continued in order to highlight differences
rather th an identify similarities , and again 90. 7 per cent
of pilots involved in the helicopter accidents held
Commercial or Sen ior Commercial Helicopter Pilot
Licences, while 15 per cent of the private/ business pilots
held equivalent licences. The graph shows tha t in 25.2
per cent of the fixed- wing accidents, pilots had only
flown 0- 10 h ours during the preceding 90 days.
H elicopter pilots on t he other hand experienced 2.4 per
cent of their accidents in the same hours' group, while
22.9 per cent of their accidents occurred with 101-150
hours in the preceding 90 days. To some degree t he
contrasts between each group reflect differing levels of
%
Private/ Business
Fixed-wing, Single engine
accidents
Cl>
(.)
c:
7
Cl>
·;:::: 25
Cl>
a.
x
Cl>
c:
~
''
', ......... ,,."'
.;
.... '\
\
Helicopter Accidents
/
\
\
\
20
\
~
\
0
\
\
\
... ...
''
''
' ' ... ...
... ...
--- -... _
OL-~--~~...-~--~~...-~---~~..-~----=:..-...
o-
10
equal
Recent experience
The amount of flyi ng performed by helicopter pilots
during the 90-d ay period preceding an accident was then
compared with similar information for pilots of fixedwing single-engine aircraft operating in the
private/ business category. T his data is p lotted in Graph
2 and illustrates some significant differences between the
two groups. T raining accidents were excluded from totals
in each case, and a small private/ business component
rem oved from helicopter figures. The horizontal axis
shows the hours groupings, while the vertical axis
measures the percentage of accidents which fell into each
hours category.
It is clear that common pilot factors between the two
periods include: ' improper operation of flight controls',
' inadequate pre-flight preparation' and 'attem pting
operation wi th known equipment deficiencies'.
1974-78 (incl.)
1. Improper operation of primary flight controls
2. Improper level-off during landing
3. Attempted operation with known equipment
d eficiencies
h elicopter accidents may not have been recognised in
past investigations, and the low incidence of this factor
amongst Australian statistics may simply reflect a similar
posi tion.
1979-83 (incl.)
30
1. Inadequate pre-flight preparation and/ or planning
2. Attempted operation with known equipment
deficiency
3. Selected unsuitable area for takeoff or landing
4. Improper landing fla re
5. L ack of familiarity with aircraft
6. Did not see or avoid objects or o bstructions
7. Improper compensation for wind conditions
8. Did not obtain/ maintain flying speed
9. Improper recovery from bounced landing
10. Attempted operation beyond experience/ abilities
Because of the apparent change in relationship
b etween helicopter total hours and accident rates around
1978, the pattern of assigned pilot factors was also reexamined in two 5-year periods in order to identify any
ch anges between 1974-78 and 1979- 83. Although there
were minor changes in the order of importance of factors
between the two periods, no re ally significant differen ces
were identified. The three most important pilot factors in
the two periods are given below:
) equal
)
)
GRAPH 2
1120
21 40
4160
61100
101150
151- 201- 250&
200 250 over
Pilot recent experience (hours) during 90 days
prior to accident
A viation Safety Digest 129 I 11
�the generally h azardous environment in which helicopters
operate. As a helicopter pilot's recent experience grows
the number of daily takeoff and landing cycles is also
likely to rise significantly, and the question of skill fatigue
cannot be overlooked.
Helicopter piloting is normally a full-time hands-on
task, and as the number of flying hours increases the
likelihood of making errors also rises. Skill fat igue is
defined as 'the deterioration in performance caused by
work that demands persistent concentration and a high
degree of skill'. It might th erefore be anticipated that
degradation in helicopter p ilot performance would occur
during sustained periods of concentrated flying. It is
associated with memory fa ilure, judgrnent , integrating
ability and presence of mind, and may be accentuated by
factors such as sleep loss. Skill fatigue also needs to be
considered in conjunction with workload . Identical fl ying
tasks may represent quite different workload levels to
pilots with d ifferent individual levels of skill and
experience. The characteristics of skill fatigue with a
supporting article may be found in Digest 121.
Photograph by Mr Jason Medway
experience and qualifications. 80.4 per cent of helicopter
pilots involved had in excess of 1000 hours total
experience and 78. 7 per cent of them had over 100 hours
on th e type in which they experienced accidents. By
comparison 61.1 per cent of the private/ business aircraft
pilot group had 500 hours or less and 58. 9 per cent of
these had 100 hours or less on type. With regard to age,
39.5 per cent of the helicopter pilots were 35 or over,
while 63.1 per cent of the second group were 35 or over.
The peak in helicopter accidents at the 101- 150 hours
mark may be partly due to a common practice in some
helicopter operations, whereby pilots fly high hours for
four successive weeks then have a two-week break. Over a
90-day period this wou ld tend to place them in this hours
bracket.
The graph confirms that lack of recent experience is
an important consideration in single-engine fixed-wing
private/ business aircraft accidents. The incidence of
these accidents declines ~.s recent experience grows, to the
point where there were almost no accidents amongst
pilots with substantial recent experience. This contrasts
with helicopter pilots who had few accidents when they
were low on recent experience. On the other hand the
proportion of their accidents in the d ifferent hours
brackets rose with increasing levels of recent experience
before peaking at 101- 150 hours.
The small proportion of helicopter accidents which
occurred when pilots were low on recency m ay be partly
related to their higher qualifications and greater
experience . On the other hand the rising proportion of
accidents which occurred with higher levels of recent
experien ce may be associa ted with special factors, besides
12 I A viat/on Safety Digest 129
Experience levels
The greater proportion of helicopter accidents was
incurred by relatively experienced pilots. Of pilots who
h ad accidents, 16.8 per cent had 101 - 300 hours on type,
14.6 per cent 301-500 hours , 16.4 per cent 501- 1000
hours, and 24.3 per cent 1001- 3000 hours. Amongst the
last group i.e. those with 1001- 3000 hours on type, t he
high level of experience did not mitigate against the
proportion of pilot factors in t heir accidents. The three
most common factors in accidents involving this subgroup were, in order of importance:
1. Did not see or avoid objects or obstructions
2. Diverted attention from operation of aircraft
3. Improper level-off prior to landing
The occurrence of these t hree pilot factors togeth er
assumes considerable significance when related to the
symptoms of skill fatigue. For instance, two symptoms of
well-developed skill fa tigue are 'inattention' a nd 'errors in
timing', each of which cou ld be related to the three p ilot
factors listed above.
There were few accidents with very low or very high
levels of pilot exper ience on type. This may be partly due
to the fact that many ex-service pilots joining the
helicopter section of civil aviation do so with considerable
previous rotary-wing time. There may also be a tendency
for very high-time civil helicopter pilots to move into
other segments of aviation, or perhaps to leave the
industry altogether. In addition, this would
approximately coincide with the time when growing
family and socia l responsibilities made prolonged
absences from home on flying duty less acceptable.
Conclusion
The combination of a hazardous operating environment ,
large number of daily flight cycles, increased flying
hours, and more subtle factors such as skill fat igue need
to be given serious consideration b y helicopter pilots a nd
operators. In turn the principle of good airmanship
remains a vital concept, particularly when the items
raised under 'Assigned factors' a bove are taken into
account •
Aircraft accident reports
FIRST QUARTER 1986
The following information has been extracted from accident data files maintained by the Bureau of Air Safety Investigation. The
intent of publishing these reports is to make available information on Australian aircraft accidents from which the reader can gain
an awareness of the circumstances and conditions which led to the occurrence.
At the time of publication many of the accidents are still under investigation and the information contained in those reports must
be considered as preliminary in nature and possibly subject to amendment when the investigation is finalised .
Readers should note that the information is provided to promote aviation safety- in no case is it intended to imply blame or liability.
Note 1: All dates and times are local
Note 2: Injury classification abbreviations
C = Crew
P = Passengers
0 = Others
N = Nil
F = Fatal
S = Serious
M = Minor
e.g. C1S, P2M means 1 crew member received serious injury and 2 passengers received minor injuries.
PRELIMINARY REPORTS (The following accidents are still under investigation.)
Date
Aircraft type & registration
Kind of flying
Time
Location (km)
Departure point/Destination
Injuries
Record Number
03 Jan
Aerocdr 690A VH-AAG
Charter - cargo operations
C1N
1715
Brisbane Old
Mungeranie SNBrisbane Old
8611003
As the pilot was manoeuvring the aircraft prior to parking, the right wing tip area struck a steel fence corner-post. This post supported a 1.8
metre high chain wire fence topped with several strands of barbed wire.
Cessna A185 E VH-KPF
Aerial mapping/photography/survey
C1N
04 Jan
8651007
Rudall River WNRudall River WA
1200
Rudall River WA
The pilot was attempting a short field landing. When he flared the aircraft it landed heavily before the threshold on a rocky outcrop. The right
maingear tyre deflated and the aircraft veered to the right and ran over a windrow, damaging the elevator.
06 Jan
Bell 47-G2 VH-OCT
Aerial mapping/photography/survey
C1N, P2N
2002
Colson Camp NT 10N
Colson Camp NT/Colson Camp NT
8641003
The aircraft was carrying out a survey in a remote area. When last light occurred the aircraft was stil l some distance from the base camp. The
pilot decided to follow a road into the camp. Enroute the engine lost power and an autorotational descent was carried out for a landing on
the road. During the landing roll the left skid struck a low dirt bank and the tail rotor struck the dirt bank on the opposite side of the road.
Non commercial - pleasure
C1N , P3N
Mooney M20 E VH-IJN
07 Jan
8621003
Camden NSW
Camden NSW/Camden NSW
1252
Approaching the circuit area the pilot selected the landing gear down, but the appropriate gear position light did not illuminate. T he pilot then
noticed that all electrical systems were inoperative. He subsequently advised that he checked the mechanical extension system and was satisfied
that the gear was down. Witnesses observed the aircraft making a normal approach but then saw the gear collapse shortly after touchdown.
Initial investigation revealed that the aircraft battery was fully discharged.
11 Jan
Piper 38 112 VH-FTI
Instructional - dual
C2N
1800
Kempsey NSW
Kempsey NSW/Kempsey NSW
8621005
The student was receiving training in crosswind take-offs and landings in 5 to 10 knot wind conditions. For the third take-off in the sequence
a minimum ground roll technique was employed. The aircraft lifted off in a slightly nose-high attitude but did not appear to be climbing or accelerating.
The instructor took control but was unable to improve the aircraft performance and the right wing and maingear collided with a fence. The
gear leg was detached, and shortly afterwards the aircraft touched down in the paddock beyond the fence. The nosegear collapsed and the
aircraft slid sideways to a halt.
C1N, P3N
Cessna 182 P VH-WTR
Non commercial - corporate/executive
14 Jan
8641002
Tindal NT/Bradshaw Stn NT
1140
Bradshaw Stn NT
After joining the circuit, the pilot noticed some cattle standing at the side of the strip. So as to avoid them should they suddenly decide to run
onto the strip during the landing, he decided to carry out a short field landing. When the aircraft was about 15 feet above the ground on final
approach, the pilot reported that it entered a rapid sink. He flared the aircraft and it landed prior to the threshold. During the landing roll the
nosegear was torn off after it struck a drum that was being used as a strip threshold marker.
17 Jan
Piper PA36-375 VH-OON
Aerial agriculture
C1N
0930
Colleambally 8NE
Colleambally 8NE/Colleambally 8NE
8621006
During the take-off run the right gear leg failed shortly after the aircraft passed through a soft patch of ground followed by a grass tussock.
The severed section of the leg punctured the right wing and the tailplane was the aircraft slid to a halt. Initial investigation indicated that the
failure of the leg was caused by fatigue.
C1N
Non commercial - pleasure
Glasflugel Libelle VH-GGS
19 Jan
8621007
Leeton NSW/Leeton NSW
1830
Leeton NSW 28NW
The pilot was competing in the Australian National Gliding championships. An outlanding became necessary when thermal activity declined
and an approach was made to a dry field which was used for irrigation. On the downwind leg of the circuit, the pilot noted that a ditch crossed
the field, however this ditch was not visible to him on final approach. During the landing roll the glider collided with the ditch.
Aviation Safety Digest 129/i
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
21 Jan
Piper 28 R180 VH-ASN
Non commercial - pleasure
C1N, P3N
1630
Mansfield VIC 19E
Mansfield VIC 19E/Moorabbin VIC
8631006
The pilot had intended to carry out a photographic flight from Moorabbin to Mansfield and return. He subsequently advised that on arrival in
the Mansfield area, one of the passengers was unwell and a decision was made to land on a grass strip. Take-off from this strip was commenced
about 90 minutes later, and the acceleration was reported to be slower than expected. The aircraft was pulled into the air near the end of the
strip, but it then descended, ran through two fences and collided with some disused farm machinery. It came to rest in a nearby river bed.
09 Feb
Piper 38 112 VH-FTE
Non commercial - pleasure
C1N
0840
Moreton Is OLD
Moreton Is OLD/Archerfield OLD
8611006
The take-off was attempted on a grassed sandy strip. The pilot reported that the aircraft seemed to accelerate more slowly than usual. At 50
knots he lowered half flap, and as the indicated airspeed approached 60 knots he realised that insufficient runway length remained to effect
the take-off. The pilot pulled back on the control column but the aircraft did not rotate. He then closed the throttle but was unable to stop the
aircraft in the remaining runway. The aircraft overan the runway and overturned.
25 Jan
Bell 47-G3B1 VH-UTX
Test
C1S, P2S
1515
Well Tree Sin 2N
Well Tree Stn NT/Well Tree Sin NT
8641004
Following the first 50 hour oil change after a recent overhaul, the engineer who completed the overhaul and service arranged for he and his
wife to accompany the pilot on a scenic flight of the local area. The flight proceeded normally for about 15 m inutes until the engine suddenly
lost power, it then ran roughly momentarily, before stopping. The pilot attempted to land the aircraft in a large clear swampy area but during
the approach it struck a large tree and crashed into the swamp.
09 Feb
Bell 205 A1 VH-UHP
Activities associated with fire control
C2N,P1S,P1M
0630
Mt Beauty VIC 3SE
Mt Beauty VIC/Mt Beauty VIC
8631012
Two firemen had finished a task in a fire-fighting area and were to be winched out. The helicopter hovered above them at about 60 feet while
the men attached themselves to the dual winch hook. The operation then proceeded normally until the men had reached the skids of the helicopter.
At this point the winch cable broke and the men fell to the ground.
26 Jan
Rolladen LS4 VH-GXG
Non commercial - p leasure
C1F
1705
Benalla VIC 1NW
Benalla VIC/Benalla VIC
8631007
The pilot was a member of the French team competing in the "Austraglide '86" gliding championships. At the end of a cross-country exercise
the pilot reported that he was 5 kilometres from the finish line. The pilot of another glider observed that when the subject aircraft was one kilometre
from the line it was apparently low. Shortly afterwards the glider collided with power lines. The tailplane was cut off by this impact and the
glider then struck the ground in a steep nose down attitude.
27 Jan
Glaser-Dirk DG300 D-2870
Non commercial - pleasure
C1N, 01N
1802
Benalla VIC 50NE
Benalla VIC/Benalla VIC
8631008
The pilot was competing in the "Austraglide '86" international gliding championships. During a cross-country exercise a number of gliders
were thermalling in the same area. The pilot noticed several gliders underneath his aircraft as he entered the thermal at about 4000 feet above
ground leve l. His entry was made via a 45 degree bank right turn, but after turning through about 90 degrees the left wingtip contacted the
forward under-fuselage area of a Discus B sailplane, VH-HNZ. This aircraft had been in a left turn with about 12 degrees angle of bank. Following
the collision, both aircraft remained under control and were flown to the planned destination without further incident.
27 Jan
Glasflugel Libelle VH-GZK
Non commercial - pleasure
C1S
1300
Warwick OLD
Warwick OLD/Warwick OLD
8611004
During the aero-tow launch the right wing of the glider contacted the ground and the glider began to veer to the right. After travelling about
40 metres in this manner the glider was seen to climb steeply and roll to the left before impacting the ground nose first.
30 Jan
De Hav D H82-A VH-BDX
Non commercial - pleasure
C1N, P1N
0945
Bond Springs NT
Bond Springs NT/Alice Springs NT
8641005
During the take-off run, the pilot applied forward pressure to the control column to raise the tail. He then maintained a constant control position
in order to allow the aircraft to become airborne in the selected attitude. About 450 metres from the start of the take-off run the aircraft became
airborne but almost immediately sank back onto the ground. Shortly afterwards it veered sharply to the right, and the pilot was unable to regain
directional control. The aircraft ran off the side of the strip and struck an embankment before coming to rest inverted.
01 Feb
Piper 25 235 VH-KRT
Non commercial - aerial application survey
C1N
1630
Flinders Island
Flinders Island/Flinders Island
8631011
The pilot was usi ng his aircraft for agricultural operations on his own land. The aircraft had been performing normally during the day, however
on this particular take-off the engine lost power when the aircraft had reached about 55 knots. There was insufficient strip length remaining
for the pilot to stop the aircraft, which struck several fences before coming to rest in a ditch 50 metres beyond the end of the strip.
01 Feb
Cessna 152 VH.:rYA
Non commercial - practice
C1 N, P1M
1545
French Island VIC
Tyabb VIC/French Island VIC
8631010
The pilot was carrying out va_rious manoeuvres in the training area. After about one hour of general flying, the pilot decided to conduct a practice
forced landing approach to a disused strip on the island. At about 200 feet on final approach, the pilot moved the carburettor heat control to
the cold position and applied full power to overshoot. The engine failed to respond normally, and produced only about 1500 rpm. The pilot
exercised the throttle control without obtaining any further power increase, and he was then committed to a forced landing. Touchdown occurred
in a cleared paddock and damage to the nosegear and propeller was sustained when the aircraft ran through a ditch.
01 Feb
Glasair FH-2 VH-HRG
Non commercial - pleasure
C1N
1700
Northam WA
Northam WA/Northam WA
8651002
As the aircraft touched down, the pilot felt the left maingear leg give way, he applied power, but was unable to keep the aircraft straight. To
avoid colliding with trees outside the airfield boundary the pilot closed the throttle and landed the aircraft. The left maingear leg collapsed and
the right wing was damaged when it struck small bushes.
02 Feb
Piper 28 140 VH-WKE
Non com mercial - pleasure
C1N, P2N
1140
Lennox Head NSW
Pt Macquarie NSW/Coolangatta OLD
8621011
While the aircraft was cruising at 2000 feet above mean sea level the engine commenced to run roughly. Trouble checks failed to determine
the source of rough running and the pilot elected to land at an enroute aerodrome. However before reaching this strip, the engine lost power
completely and the pilot was committed to a forced landing. Because of crowds at an adjacent beach, the pilot attempted to land on a road.
Touchdown was further along the road than expected because of a strong tailwind component, and the aircraft collided with a kerb before comi ng
to rest. Initial investigation disclosed a number of mounting stud failures on one cylinder, together with an exhaust valve failure in the same cylinder.
06 Feb
Transav PL12-T300A VH-ABU
Aerial agriculture
C1N
1800
Nannup WA
Nannup WA/Nannup WA
8651003
The pilot was operating from a strip on top of a ridge line. Because of the slope of the strip, landings were being made with a quartering tailwind
of about 10 to 15 knots. At the end of a landing roll, the pilot commenced to turn around prior to re-loading, when the wind gusted to about
25 knots. The pilot applied more power in order to assist the turn, but the nosewheel bounced into the air. The aircraft weather-cocked and
ran off the side of the strip. It then ran down the slope of the ridge line until the nosewheel entered a large hole and the aircraft overturned.
08 Feb
Hughes 269 A VH-GMD
Aerial mustering
C1N
Brewarrina 56NNE
1300
Amaroo HS NSW/Amaroo HS NSW
8621014
The aircran had been engaged in mustering cattle in flat, open country. The pilot elected to land near a utility van to obtain further instructions
from stockmen in the vehicle. Approaching the vehicle, the aircraft suddenly commenced to vibrate severely and to lose height. The pilot was
unable to avoid a collision with the utility, following which the aircraft struck the ground heavi ly and overturned.
Aviation Safety Digest 129/ii
11 Feb
Hughes 269 C VH-WAA
Aerial mapping/photography/survey
C1N , P1N
1420
Cheviot Hills OLD
8611007
Cheviot Hills OLD/Cheviot Hills OLD
The helicopter was being used as a platform for test equipment. Part of the test equipment included an aerial that was mounted vertically below
the helicopter. This aerial could be retracted and stowed horizontally for landing by operating a control which was positioned in front of the
technician. On this occasion the pilot inadvertently attempted to land the helicopter with the aerial extended. Just prior to touch down the helicopter
began to vibrate, the pilot lowered the collective and the helicopter rolled onto its right side.
15 Feb
Burkhart Astir CS VH-WVM
Non commercial - pleasure
C1N
1502
Bunyan NSW
Bunyan NSW/Bunyan NSW
8621018
The pilot was making a landing approach and intended to touch down at the threshold of the strip. The strip had recently been mown and
its edges were clearly defined, however it was surrounded by long grass. Touchdown occurred short of the threshold, the left wing entered
the long grass and the glider ground looped.
16 Feb
Beech 95-C55 VH-JZN
Charter - passenger operations
C1M
1230
Brampton Is 2SE
Brampton Island OLD/Mackay OLD
8611008
The pilot reported that shortly after take-off he positioned the fuel selector to feed fuel to the right engine from the right auxiliary fuel tank.
After levelling the aircraft at the cruising altitude of 1500 feet, he noticed the right engine falter, and immediately positioned the fuel selector
for that engine to 'crossfeed'. The right engine then stopped. The right engine fuel selector was then positioned to draw fuel from the right
main fuel tank, however the engine did not restart. The left engine then stopped, attempts to restart it were unsuccessful. The pilot transmitted
a 'Mayday' call and ditched the aircraft.
20 Feb
Airtract AT 301 VH-FRC
Aerial agriculture
C1S
1945
Walgett NSW 65E
"Whitewoods" NSW/"Whitewoods" NSW
8621019
The pilot was making n ight spraying runs over a cotton crop. During the third run at about 50 feet above ground level, the engine suddenly
lost all power. The pilot attempted a landing at slow speed in a flooded rice paddock. Almost immediately after touchdown, the aircraft nosed
over and sank into the soft muddy surface. The pilot was able to extricate himself from the partly water-filled cockpit.
21 Feb
Piper 18 150 VH-SOP
Non commercial - business
C1N
1715
Katherine NT 58SW
Scott Creek NT/Scott Creek NT
8641007
Near the end of the landing roll the left wing rose and the aircraft lifted off the strip, then settled back onto the ground on the right mainwheel.
The brakes were still applied and the aircraft turned sharply to the right and the right wing struck the ground.· The aircraft rolled over and came
to rest inverted.
23 Feb
Piper 28-161 VH-AAS
Instructional - solo (supervised)
C1N
0920
Alice Springs NT
Alice Springs NT/Alice Springs NT
8641008
After a dual check the p ilot's instructor briefed the pilot to carry out two circuits, each with a full stop landing. Following the first circuit and
landing, the pilot applied power to commence the take-off without bringing the aircraft to a stop. The aircraft veered sharply to the left, became
airborne momentarily, before settling back onto the ground outside the flight strip. It then continued under full power across a stormwater drain
for another 38 metres before coming to rest.
Cessna 210 M VH-IDZ
Non commercial - pleasure
24 Feb
C1N
1000
Caloundra OLD
Brisbane OLD/Caloundra OLD
8611009
The aircraft touched down just short of the sealed runway and bounced. The pilot applied power and the aircraft was landed, mainwheels first,
on the runway. Towards the end of the landing roll, as the nose of the aircraft was lowered, the propeller contacted the runway and the aircraft
came to rest with the nosewheel pushed back against the gear doors. Pieces of metal from the nosegear retraction mechanism were found
along the runway.
26 Feb
Cessna 402 VH-MWF
Charter - cargo operations
C1N
0247
Rockhampton OLD
Rockhampton OLD/Mackay OLD
8611010
As the aircraft was climbing through 1000 feet the pilot noticed a reduction in manifold pressure and fuel flow readings for the right engine.
He advanced the right throttle and found that the engine instruments indicated that the engine was performing as if normally aspirated. A short
time later he saw flames coming from the right engine. He shut the fuel off to the engine but was unable to feather the propeller. The fire did
not go out. However, the pilot was able to successfully land the aircraft at Rockhampton where the fire was extinguished. An inspection of the
aircraft revealed that the number 4 cylinder was cracked and holed around the seat of the exhaust valve.
27 Feb
Aerocdr 500-S VH-SDO
Test
C2F,C1S
0935
Can ning Dam WA 2N
Jandakot WA/Unknown
8651005
The flight was planned to check the onboard survey equipment. After departing Jandakot the aircraft operated to the south of the airfield for
about 80 minutes, before the pilot advised that he would be be extending his operation to the east over the Darling Ranges. The aircraft was
then sighted, by several witnesses, over the foothills heading in a easterly direction. These witnesses reported that the engines were not operating
normally. A short time later, the aircraft was observed to pass over the dam wall at an altitude of about 25 feet, and head down a valley in
a northerly direction before disappearing from sight.
An inspection of the wreckage indicated that the aircraft had collided with two 30 metre high trees, in a nose high attitude at a low forward
airspeed, before falling to the ground below the trees. At impact neither engine was delivering power and the fuel system, wh ich was found
to be relatively intact, contained only 9 litres of fuel.
01 Mar
Glasflugel H206 VH-GSA
Non commercial - pleasure
C1N
1645
Bacchus Marsh VIC
Bacchus Marsh VIC/Bacchus Marsh VIC
8631014
During the turn onto final approach, the pilot noticed a tug aircraft apparently making an approach to the same strip. He continued his turn
in order to avoid any conflict with the tug, and the aircraft touched down on a cross-strip. It then ran through a ditch before colliding with a fence.
Aviation Safety Digest 129/iii
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Date
Time
Injuries
Record Number
03 Mar
Partavia P68C.:rc VH.:rcu
Aerial mapping/photography/survey
C1N , P5N
Orbost VIC 55ENE
Orbost VIC 55ENE/Mallacoota VIC
1430
8631015
The pilot reported that acceleration was normal during the take-off run and the aircraft was rotated at about 70 knots. He further stated that
the aircraft experienced " a sudden loss of lift" and that he then released some of the back pressure on the control column . As the aircraft
became airborne it struck the airfield boundary fence and the left mainwheel was dislodged . A circuit was completed and during the subsequent
landing roll the left gear leg collapsed and the aircraft ran off the strip.
05 Mar
Cessna 150 L VH-KOF
Non commercial - practice
C1N , P1M
1759
Alice Springs NT
Alice Springs NT/Alice Springs NT
8641009
At the completion of a local pleasure flight the pilot decided to carry out three practice circuits. The first two landings were 'without incident
but on the third landing the aircraft touched down on the right mainwheel and bounced. The pilot applied power in an attempt to stabilise the
aircraft, but the angle of bank to the right increased and the right wing struck the ground. The aircraft cartwheeled onto the left wing and came
to rest inverted 190 metres to the right of the runway centreline.
06 Mar
Piper PA25·235 VH-JPT
Test
C1N
8611011
1130
Archerfield OLD
Archerfield OLD/Archerfield OLD
The pilot was conducting a flight to check the output of the spray system fitted to the aircraft. During the take-off he heard a noise from the
rear of the aircraft and noticed something moving away from the aircraft. He continued with the take-off and two spray runs before positioning
the aircraft on a downwind leg for landing. As the aircraft was turned onto the base leg the pilot realised that he could not apply left rudder.
The pilot stated that he then intended landing the aircraft on the base leg but found that cone markers blocked the path. The aircraft was then
lined up with and landed on runway 22. An inspection found that a leaf spring which supported the tailwheel had failed.
11 Mar
Piper 601 VH-CUO
Charter - cargo operations
C1F
1717
Lismore NSW
Coolangatta OLD/Lismore NSW
8621023
When the aircraft arrived in the destination area, another aircraft was also in the circuit. The pilots agreed that VH-CUO would follow the other
aircraft. However, insufficient separation was maintained and the pilot of VH-CUO initiated a go-around. Witnesses observed the aircraft operating
apparently normally, but at a low height above the ground. A turn was then commenced, indicating to the witnesses that the pilot was intending
to land in the opposite direction. The angle of bank was in the order of 60 degrees, and about three-quarters of the way through the turn the
nose dropped rapidly. The aircraft then dived steeply into the ground, and was destroyed by the impact and subsequent fire.
Bell B206 VH-BHY
Non commercial - practice
C2N
12 Mar
Adelaide SA/Adelaide SA
8641010
1025
Adelaide SA
During the initial climb after take-off, before translational lift was obtained, the check pilot closed the throttle to simulate an engine failure. The
aircraft touched down heavily on the rear of the left pop-out float and pitched forward onto the right float. It then rolled backwards bending
the rear of the tail boom, which was then severed by the main rotor. The crew shut the helicopter down before evacuating the aircraft.
Airparts 24 VH-AFN
Aerial agriculture
C1N
19 Mar
Enmore NSW/Enmore NSW
8621024
Armidale NSW 25SE
1028
Before commencing the 17th spreading flight for the day, the pilot noted that one fuel tank indicated empty and the other indicated one quarter
full. After a normal take-off and turn at about 150 feet above ground level, the engine lost all power. The pilot was committed to a landing in
a small paddock with a downhill slope. Touchdown was made in light tailwind conditions, and during an attempt to turn the aircraft to lengthen
the landing distance available, the right wing struck the ground. The aircraft partially ground looped, one tyre was rolled off its rim, and the
aircraft came to rest within the confines of the paddock. The pilot then physically checked the fuel tank contents and found that only a few
litres remained in one of the tanks, while the other was empty.
23 Mar
Bellanca 8GCBC VH·PEV
Non commercial - pleasure
C1N, P2N
0945
Harts Range NT
Bond Springs NT/Harts Range NT
8641011
During the landing roll both mainwheels entered soft areas in the strip surface. The aircraft swung through 120 degrees to the left then slid
sideways for 17 metres before the right maing9ar collapsed. The wing struck the ground and was bent upwards.
28 Mar
Osprey 2 VH-OLC
Non commercial - pleasure
C1S, P1S
0935
Tyabb VIC
Tyabb VIC/Tyabb VIC
8631018
The aircraft had previously been flown to test a new propeller installation. Maintenance personnel then checked the propeller, after which the
pilot taxied for a local flight. Shortly after take-off there was a sudden and complete loss qt power. The pilot attempted a forced landing in a
paddock, but the aircraft stalled at a low height and struck the ground heavily.
29 Mar
Piper 28 161 VH-TVE
Non commercial - pleasure
C1N
2044
Narrogin WA
Jandakot WA/Narrogin WA
8651008
The pilot, who held a Class Four Instrument Rating, had planned the flight as currency training. At Narrogin, he set the aircraft up on a long
final approach but reported that on several occasions during the approach he found that the aircraft became low and he needed to adjust the
flight path. About midway along final, the pilot stated that he felt a thump on the left side of the aircraft but the aircraft continued to operate
normally, so he continued with the approach and landing. After parking the aircraft, damage to the left wing was noticed.
Aviation Safety Digest 129/iv
Kind of flying
Departure point/Destination
Injuries
Record Number
31 Mar
Piper 28 161 VH-BZB
Instructional - solo (supervised)
C1N
0945
Lilydale VIC
Lilydale VIC/Lilydale VIC
8631019
The pilot was conducting her second solo flight. After a normal approach the aircraft landed heavily and bounced . The pilot was unable to
correct the situation and a further two bounces occurred. When the aircraft was stopped, damage to the nosegear assembly and engine mounts
was discovered.
01 Mar
Enstrom F28·F VH-IPE
Charter - passenger operations
C1N, P1N
1630
Narellan NSW
Narellan NSW/Narellan NSW
8621020
The pilot had been carrying out a series of joy flights at a rural field day. Refuelling was taking place from 200 litre drums, which had been
placed in the shade of a large tree. On the second occasion that fuel was required, the pilot hover-taxied to the drums, which were rolled out
of the way on completion of the refuelling. As the pilot started to hover-taxi again, the helicopter suddenly rose higher than anticipated and
the main rotor struck the overhanging branches of the tree. One rotor blade de-laminated, severe vibration occurred, and the helicopter struck
the ground heavily.
03 Mar
Piper 31 VH-WDY
Non commercial - aerial ambulance
C3N
1940
Derby WA
Derby WA/Broome WA
8651006
The pilot commenced the take-off run and confirmed that full power was selected. At an indicated airspeed of 90 knots he rotated the aircraft
and waited for the performance instruments to indicate that a positive rate of climb and the single engine climb speed had been achieved.
The aircraft did not accelerate beyond an airspeed of 95 knots and a positive rate of climb was not obtained. The pilot retracted the gear to
avoid the boundary fence, and then realised that the left engine was losing power and altitude was not being maintained. He closed the throttles
and the aircraft landed in the runway overrun area.
Aircraft type & registration
Location
1
FINAL REPORTS (The investigation of the following accidents has been completed.)
Date
' Time
Pilot licence
Aircraft type & registration
Location (km)
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Injuries
Record
Number
Rating
~,_-
'-
01 Jan
Romainian IS-28B2 VH-IKZ
Non commercial - pleasure
C1N, P1N
1423
Leongatha VIC
Leongatha VIC/Leongatha VIC
8631001
Glider
Glider
57
1043
3
The pilot, who was also the holder of a Private Pilot Licence, was conducting his first gliding flight for the day. The glider was aero-towed to
1100 feet above the aerodrome, but only weak lift was encountered in the area. The pilot elected to return for landing and commenced a normal
circuit. On the downwind leg strong sink was encountered and the base turn was conducted at about 300 feet above the ground. Indicated
airspeed at the time was reported to be about 55 knots. The pilot subsequently advised that the roll into the turn was normal, but he was unable
to level the wings again, even with full opposite aileron. The aircraft continued descending in a wing-low attitude and struck the ground about
250 metres before the threshold of the strip.
Investigation revealed no evidence of any pre-impact defect or malfunction of the controls, and atmospheric conditions at the time were reported
as being stable. When the sink was encountered on the downwind leg, the pilot had modified his circuit by flying closer to the strip. As a result,
the angle of bank required for the base turn was steeper than normal. It was considered probable that the aircraft had stalled during this turn
onto base, with insufficient height r.emaining to allow the pilot to recover control.
02 Jan
Cessna 172 N VH-UJS
Non commercial - pleasure
C1N, P1M
1245
Agnes Waters Old
Archerfield Old/Great Keppel Is OLD
8611001
Private
34
145
40
None
The aircraft was being operated on a VFR flight and was cruising at 1500 feet above ground level. The engine suddenly began to run roughly,
and the rpm dropped to about half the normal setting . Emergency trouble checks failed to alleviate the problem, and the pilot transmitted a
Mayday call as he tracked towards a nearby strip for a precautionary landing. The approach to this strip was too high and power was applied
in an attempt to go around. However, severe engine vibration occurred, and the pilot was committed to a forced landing in densely forested, hilly terrain.
The power loss and vibration was caused by the partial separation of the exhaust valve head on one of the cylinders.
02 Jan
Cessna R182 VH-IVO
Non commercial - pleasure
C1N , P1N
1515
Albury NSW
Dubbo NSW/Albury NSW
8621001
Private
49
179
6
None
The pilot carried out a normal approach and landing. The nosewheel was kept off the ground until the speed had reduced to a suitable figure.
However, almost as soon as the wheel contacted the runway it became detached, and the aircraft skidded to a halt 97 metres further on.
The nosewheel assembly had failed from overload, which had probably resulted from a recent heavy landing . There was ample evidence
to indicate that the damage had not occurred on this particular landing, and the date and circumstances surrounding the heavy landing could
not be established.
02 Jan
Cessna A188B A1 VH.:rZK
Aerial agriculture
C1S
1915
Gunnedah NSW 25NW
Carroll NSW/Carroll NSW
8621002
Commercial
25
1125
200
Agricultural class 2
The aircraft was engaged in spraying a cotton crop. The spray runs were being flown into the west in the afternoon. About three-quarters of
the way into the treatment area a power line crossed the swath path at right angles. The line was carried on poles about 300 metres apart,
and the aircraft had crossed under or over the line on about 8 occasions. With the sun shining directly in his eyes, the pilot found it difficult
to see the markers. While concentrating on lining up the swath run, he temporarily forgot the presence of the power line. The aircraft collided
with the cables and subsequently struck the ground in a steep nose-down attitude 57 metres beyond the run of the lines. The pilot sustained
serious burn injuries in the post-impact fire which gutted the aircraft.
Piper 38 112 VH-MIR
Instructional - solo (supervised)
C1N
04 Jan
1145
Swan Hill VIC
Swan Hill VIC/Swan Hill VIC
8631002
Student
35
14
14
None
Following a dual check, the pilot was authorised to carry out a series of solo circuits and landings. Two landings had been completed successfully,
however the pilot advised that on the next approach the aircraft was affected by a wind gust. Appropriate corrections were made, but another
gust was encountered and the pilot applied power in order to go around . Almost immediately afterwards the left wingtip contacted the ground,
followed by the left mainwheel. The nose gear collapsed when it struck the ground and the aircraft came to rest at right angles to the strip direction.
The wind at the time was generally down the strip at about 10 knots, with gusts to about 15 knots. The pilot had flown successfully in similar
conditions in the past, but on this occasion had not been able to react sufficiently quickly when the left wing dropped.
05 Jan
Piper 25 235 VH·KLZ
Aerial agriculture
C1N .
1000
Willow Glen OLD
Willow Glen OLD/Wilfow Glen OLD
8611002
Commercial
31
837
330
Agricultural class 1
As the aircraft approached the end of the landing roll the left main landing gear leg collapsed. The aircraft swung to the left before coming
to rest in a left wing low attitude.
The landing gear leg had failed due to overload . The cause of the overload failure could not be determined.
Aviation Safety Digest 129/v
�Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
Victa 115 VH-RSI
Non commercial - pleasure
C1N, P1N
0915
Pelican Field VIC
Pelican Field VIC/Trafalgar VIC
8631003
Private
47
350
150
None
Shortly after a normal take-off, the pilot sensed that the engine was not delivering full power and the passenger commented that he could
detect rough running. The pilot attempted to reach a clear area ahead, but the aircraft collided with 3 metre high scrub while in a nose-high
attitude. It then spun through 180 degrees before coming to rest about 10 metres from the initial impact point. A fire broke out which destroyed
most of the fuselage and part of the wings.
The investigation was hampered by the degree of fire damage, however no fault was found with the engine which might have explained
the reported loss of power. Atmospheric conditions were conducive to carburettor icing, but whether this had in fact occurred could not be determined.
06 Jan
08 Jan
SZD 48 Jantar VH-UKQ
Air show/air racing/air trials
C1M
1851
Gawler SA 1N
Gawler SNGawler SA
8641001
Glider
62
1017
240
Glider
The pilot was taking part in a gliding race. About 3 kilometres from the destination the pilot realised that he would not reach the aerod rome
and that an outlanding would be necessary. He selected a small paddock with trees on the approach boundary, but sink was encountered
and he found he was unable to clear these trees. The aircraft stalled either just before or coincident with colliding with the tree tops. The right
wingtip then struck the ground 22 metres beyond the trees and the glider rotated through about 140 degrees to the right before the fuselage
impacted heavily with the ground.
The decision to outland was left too late.
10 Jan
Beech C23 VH-ARF
Non commercial - pleasure
C1N, P3N
1040
Moruya NSW
Canberra ACT/Moruya NSW
8621004
Private
27
167
3
None
After a normal approach, the pilot was surprised when the aircraft bounced on initial touchdown. A second bounce occurred, during which
the pilot applied power to cushion the next touchdown. The power application seemed to have little effect and the nosewheel and propeller
struck the ground heavily. The aircraft then ran off the side of the runway and collided with a fence.
.
The pilot had been given a check flight on the aircraft two days previously. During his check, he was advised to use less flap for landing
than that specified in the Flight Manual. At the time of the accident, the aircraft was being operated in excess of the maximum permitted all-upweight. The pilot advised that he had not carried out a weight and balance calculation because the hiring organisation had assured him that
the aircraft could be operated with full fuel tanks and four persons on board. Following the bounced landing the pilot had not initiated a go
around and directional control had been lost after the nosegear suffered damage on heavy contact with the runway.
10 Jan
Schleicher KA-6 VH-GTW
Airshow/air racing/air trials
C1N
1830
Temora NSW SSE
Temora NSW/Temora NSW
8621012
Glider
30
130
40
Glider
Towards the end of a 4 hour competition flight, the pilot realised that the aircraft would not reach the finishing line and that an outlanding would
be necessary. After establishing the aircraft on final approach to the selected paddock, the pilot noticed a pile of stones obstructing the target
touchdown area. While manoeuvring to avoid this obstruction the left wing of the aircraft struck the ground and a ground loop ensued.
The pilot had been suffering the effects of a head cold and sinus infection, and had probably become fatigued during the flight in demanding
conditions. He had persisted in his efforts to reach the finish until the glider was too low to allow a more suitable paddock to be selected for
the outlanding.
T his accident was not the subject of an on-site investigation.
19 Jan
Schneider ES-60B VH-GYT
Non commercial - pleasure
C1N
1521
Ross TAS 8W
Woodbury TAS/Woodbury TAS
8631004
Glider
60
51
38
Glider
The pilot had been soaring in wave conditions, when sink was encountered and an outlanding became necessary. The field initially selected
was obstructed by a power line and the pilot manoeuvred towards another area. On late final approach the aircraft collided with a single strand
power line and subsequently struck the ground heavily. The pilot later advised that he had seen a pole supporting the line but had thought
it was aligned in another direction.
The large distance between the poles supporting the power line reduced the possibility of the pilot being able to accurately assess the direction
of the line.
20 Jan
Rockwell 114 VH-DDY
Non commercial - pleasure
C1N, P1N
1705
Sea Lake VIC
Sea Lake VIC/Essendon VIC
8631005
Private
54
1000
100
Instrument rating 1st class or class 1
Shortly after take-off the pilot's door opened. The passenger became very agitated and the pilot elected to carry out a low level ci rcuit and
landing. The passenger's condition deteriorated to the extent where the pilot was experiencing difficulty in concentrating on the approach.
The aircraft touched down in a paddock 22 metres short of the aerodrome boundary fence, ran through the fence and came to rest near the
strip threshold.
Atmospheric conditions at the time were conducive to the formation of downdraughts and willy-willies. It was possible that the aircraft was
affected by such a disturbanc.e at a time when the pilot was distracted by his passenger's condition.
24 Jan
Rockwell S2R VH-LGG
Aerial agriculture
C1 N
1000
Griffith NSW 15ESE
Ag Strip 3 km NE/Ag Strip 3 km NE
8621008
Commercial
46
9000
4000
Agricultural class 1
Shortly after an apparently normal take-off, engine power was lost and the pilot was committed to a landing straight ahead. Initial touchdown
was in a flooded rice paddy, and the aircraft then struck a levy bank and ran through a fence, coming to rest inverted in an adjoining dry paddock.
Investigation revealed that one cylinder head had become detached from the engine and had removed a section of the inlet manifold.
T he cylinder head had failed as a result of fatigue cracking which had commenced at the edge of an exhaust valve insert.
26 Jan
Corby CJ1 VH-IHT
Non commercial - pleasure
C1F
0930
Busselton WA
NA Cowaramup 32SSW/Busselton WA
8651001
Private
41
490
152
None
The aircraft was one of a number conducting a "fly-in" to the property. On arrival overhead the farm, the aircraft was observed to make a low
pass over the homestead, during which the pilot attempted to drop flour bombs on the building. Whi le the pilot was attempting to drop the
bombs, the right wing of the aircraft struck a tree about five metres above the ground. The aircraft rolled to the right and collided with the ground
beyond the tree.
An inspection of the wreckage did not reveal any defects that could have contributed to the accident. The pilot had recently been counselled
by members of his Association regarding previous instances of low flying.
Aviation Safety Digest 129/vi
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
29 Jan
Hughes 269-C VH-IHV
Instructional - dual
C2N
1035
Moorabbin VIC
Moorabbin VIC/Moorabbin VIC
8631009
Commercial - helicopter
25
1146
900
Flight instructor grade 1 or 2
The student had a total of 45 hours helicopter flying, and also had a Private Pilot Licence with 130 hours fixed wing experience. During a period
of practice circuits and engine failures in 15 to 20 knot wind conditions the student required several practice autorotative landings in order to
reach a satisfactory standard. These exercises were commenced about 700 feet above the ground. During this period, the Tower advised that
the wind strength had increased to 35 knots. Conditions remained stable and the instructor elected to continue with the training. A further engine
failure after take-off was simulated from about 400 feet, and on successful completion of this manoeuvre, the instructor simulated a failure at
100 feet. On this occasion a high rate of descent developed and the instructor took control. The touchdown was firm, and was on the heels
of the skids. The helicopter rocked forward and the main rotor struck the tail boom.
It was considered probable that the aircraft had been affected by a reduction in wind speed at the time the engine failure was simulated.
The low height at which the manoeuvre was being performed did not allow sufficient time for adequate corrective action to be taken to arrest
the rate of descent.
30 Jan
Piper 25 235 VH-CPT
Instructional - solo (supervised)
C1M
1700
Cudal NSW 1NE
Cudal NSW/Cudal NSW
8621010
Other (Foreign, Military, etc)
36
2300
4
None
The pilot was a Chinese citizen who was being trained, as part of an Australian Development Aid program, to a standard equivalent to that
required for an Agricultural rating. His Chinese Commercial Licence was suitably endorsed to allow training in this country. The flight in question
was authorised as a practice spraying exercise and was to be the pilot's last solo sequence before a flight test. At the end of the first practice
spraying run the entry into the procedure turn was delayed, and the turn was then conducted at less than the normal angle of bank. This placed
the aircraft in a wide and low turn, during which it collided with a tree. This collision occurred at about 50 feet above ground level, and the
aircraft struck the ground 35 metres beyond the tree.
The pilot subsequently reported that the aircraft had been affected by a downdraught. However, other pilots and ground witnesses in the
area indicated that excessive sink or downdraughts were unlikely to have occurred. The tree struck was prominent and contrasted well with
the surrounding vegetation. It was likely that the pilot was looking back to check his flight path in relation to the spraying runs and had not
seen the tree prior to the collision.
Cessna 182 B VH-MPM
Sport parachuting (not associated with an airshow)
C1N, P4N
1255
Toogoolawah OLD
Toogoolawah QLD/Toogoolawah QLD
8611005
Commercial
23
958
102
Instrument rating class 4
During the take-off run, when the indicated airspeed was about 40 knots, the pilot saw three wallabies run onto the strip in front of the aircraft.
He rotated the aircraft in an attempt to avoid the animals, but one of them collided with the tailplane. The pilot closed the throttle and landed the aircraft.
The fencing around the aerodrome was inadequate to keep out native fauna and there was high vegetation close to the sides of the strip.
The pilot stated that he had not previously seen wallabies within the boundaries of the aerodrome.
This accident was not the subject of an on-site investigation.
01 Feb
Cessna A188A A1 VH-AIN
Aerial agriculture
C1N
0655
Narromine 23NE
Trangie NSW/Trangie NSW
8621013
Commercial
48
9000
250
None
Spraying operations were planned to be conducted on two paddocks. A briefing on the operation was passed to the pilot by telephone by one
of the owners of the property the previous even ing. The briefing indicated that a particular power line was strung outside the boundary of the
smaller of the paddocks, clear of the likely swath run approach path. Based on the information supplied, the pilot drew a map of the area.
In fact, the line cut across the corner of the paddock.
Before commencing operations, the pilot carried out an aerial inspection of the area. However, he failed to detect the actual position of the
power line. While descending for the first run over the paddock, the aircraft struck the line. The impact partially severed the left wing, and a
fire broke out behind the engine firewall. The pilot was able to complete a semi-controlled landing in the adjacent paddock, and the fire was
extinguished by the ground party.
06 Feb
10 Feb
Cessna A185 F VH-CWH
Activities associated with aerial agriculture
C1N
0845
Taralga NSW 16E
Gunning NSW/Taralga NSW 16E
8621015
Commercial
31
2631
237
Agricultural class 1
Prior to his departure for the agricultural strip, the pilot had been assured that there would be no stock in the paddock containing the strip.
As the aircraft was flared for landing, three sheep ran out from tall thistles adjacent to the strip. One of the sheep struck the right main gear
leg and the pilot conducted a go around. He was informed that the leg was out of alignment, and elected to divert to a more suitable aerodrome.
The gear leg folded during the landing run.
The person who advised the pilot that there was no stock on the strip had not made a thorough inspection of the area.
Piper 31 350 VH-RDA
Charter - passenger operations
C1N, P9N
1115
Broken Hill 15SE
Coonbah Sin SNBroken Hill SA
8641006
Commercial
39
9757
350
Instrument rating 1st class or class 1
Shortly after take-off the pilot noticed a 10 to 15 centimetre gap between the forward ends of the upper and lower cowlings on the left engine.
He elected to continue the flight at reduced airspeed and engine power. About 15 kilometres from the destination the upper cowling became
detached and struck the horizontal stabiliser. It remained wrapped around the stabiliser and resulted in severe vibration and a temporary loss
of elevator control. The pilot was able to regain control, and during the turn onto a lo11g final approach elevator control returned to normal when
the engine cowling fell free.
The cowling did not become detached until well after departure. It was likely that an uneventful landing could have been carried out had
the pilot returned to the departure aerodrome as soon as he noticed the problem. The detached cowling was not found and the reason for
the failure of the latches to hold it in place was not determined. However, the surface of the departure strip was reported as rough and the
aircraft had flown about 12 hours since the cowlings were last disturbed.
13 Fe b
Aviation Safety Digest 129/vii
�Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
FINAL UPDATES {The investigation of the following accidents has been completed. The information is additional
to or replaces that previously printed in the preliminary report.)
Date
Time
16 Feb
Romainian IS-2862 VH-WVU
Instructional - dual
C2N
1215
Richmond NSW
Richmond NSW/Richmond NSW
8621016
Glider
26
350
70
Glider
The fl~ght was intended to give the student practice in the procedures required in the event of a breakage of the tow line. The instructor released
the glider.from the t.ow at about 350 feet above ground level. The. st.udent man.oeuvred the aircraft towards the strip. On final approach both
pilots realised the aircraft was low, but they expected 11 to land w1th1n the confines of the strip. However, the left wing struck a tree some 19
metres from the aerodrome boundary. This impact slewed the aircraft, which then collided with a fence before striking the ground while travelling
backwards.
The pilot of the tug ~i rcraft had not complied with the pre-flight briefing, which required him to maintain runway heading after take-off. The
tug had turned to the right at about 200 feet above ground level. This action placed the glider in a less favourable position for the pilot being
c~ecke~ to employ th ~ s~andard procedure for returning to the field when the cable break was simulated. Although he was an experienced
glider. pilot, this was his first cable break exercise for three years and he was not in current flying practice. At the time the pilots realised that
the gild.er was low, suitable areas for an outlanding were available, but the instructor relied on the other pilot's judgment and allowed the approach
to continue.
17 Feb
Beech D55 VH-CLA
Charter - cargo operations
C1N
1845
Sydney NSW
Bankstown NSW/Sydney NSW
8621017
Commercial
32
1500
120
Instrument rating 1st class or class 1
The pilot advised that during the landing run, he inadvertently selected the landing gear up instead of the flaps. The nose and right gears
retracted and the aircraft slid to a halt on the edge of the runway.
The !anding "'!f!-S the last in the J;>ilot's duty period and he subsequently advised that he had relaxed after achieving a good touchdown in
crosswind cond1t1ons. For the previous two weeks he had been operating another airc raft type in which the gear and flap selectors were in
the opposite locations to those in this aircraft.
18 Feb
Piper 32 300 VH-RRZ
Non commercial - pleasure
C1N; P4N
1242
Flinders Island
Essendon VIC/Flinders Island
8631013
Private
19
173
16
Instrument rating class 4
On arrival at the destlna.tion, the pilo_t noted that the wind was from the west-south-west, but joined the circuit for landing into the north-east.
~n final ~pproach the air~raft was h1.gh and fast, and touched down with only 330 metres of the 1100 metre strip remaining. At this time the
p1_lot realised he was landing downwind, and shortly afterwards applied full power in an attempt to go around. However, the aircraft collided
with the aerodrome boundary fence and came to rest on its belly after crossing a road and striking another fence.
20 Feb
Cessna 150 H VH-KQR
Non commercial - aerial application/survey
C1N
1015
Koonmarra Stn 20W
Mt Hale WA/Koonmarra Sin WA
8651004
Private restricted
45
189
183
None
The pilot was engaged in she~p ~po~ting . The aircraft had been refuelled two days p rior to the flight and before departure the pilot had checked
the fuel contents ~a~ges, which indicated full fuel. After about two hours of the planned three hour flight, the pilot noticed that one of the fuel
conte~ts gauges indicated empty and the other almost full. As he was near one of the property airstrips, the pilot decided to land the aircraft
and dip t h~ tan~. ~aving app?rently satisfied hin:iself that sufficient fuel remained he continued the flight. An hour later, as he was returning
I~ the Station airstrip, the engine stopped. The aircraft was landed on a road but during the landing roll the left wing struck a tree and the
aircraft ran off the road and into the bush, sustaining further damage.
An inspection of the aircraft revealed that the engine had stopped after the usable fuel had been exhausted. The fuel gauge for the right
fuel tank was found to overread by 10 hires, however the reason the fuel had been exhausted after a flight time of only three hours could not
be positively determined.
02 Mar
Cessna A185 E VH-RKZ
Glider towing
C1N
1130
Warkworth NSW
Warkworth NSW/Warkworth NSW
8621021
Private
39
2100
300
None
During th~ daily inspection prior to a ~eries of gl!der towing operations, the pilot noticed that the brake linings were worn. During the landing
roll following the third of these operations, the right brake failed and the airc raft ground looped before coming to rest.
The_ brake ~ad failed following the lo~~ of hydraulic fluid from the seal for the brake caliper piston. This was caused by excessive piston travel,
asso?1ated with severely worn brake linings. When the assembly was dismantled, it was found that the linings had worn completely off the
backing plate, and those on the pressure plate were only 1.1 millimetres in depth. Both b rake discs were pitted from the effects of corrosion
which would have caused the excessive wear in the linings.
'
09 Mar
1420
Commercial
Aircraft type & registration
Location (km)
Age
Hours Total
Pilot Ucence
Hours on 1YPB
Rating
Record
Number
28 Jun 84
Cessna 210 L VH-KWW
Private
8451017
1410
Kalgoorlie WA
46
934
234
None
When the pilot selected the gear up after take-off, the retraction cycle took longer than normal. The gear was selected down prior to the next
landing and although the gear up light extinguished the gear motor did not operate and the gear down light did not illuminate. Attempts to
lower the gear using the manual system were unsuccessful and the aircraft was diverted to a more suitable airfield. During the subsequent
landing roll the main gear, which was only partially extended, collapsed.
Although the pilot was experienced on the aircraft type and carried out a trouble check of the gear system, he did not reset the hydraulic
pump circuit breaker, which had tripped. The circuit breaker had probably tripped during the retraction cycle after the previous take-off. The
reason the manual extension did not operate could not be determined.
n
29 Sep 84
Cessna A188B A1 VH-EVU
Commercial
8411043
1045
Coreen OLD
42
1845
20
Agricultural class 2
The strip being used was aligned south-east and the wind of 15 kt was swinging from south-east to south-west. On the second take-off for
the day acceleration was sluggish and the pilot kept the main wheels in contact with the strip surface for longer than normal before allowing
the aircraft to become airborne. Shortly after liftoff the aircraft mushed and the wheels contacted the ground. The pilot abandoned the take-off
attempt and the aircraft came to rest 240 metres beyond the end of the strip after sustaining damage to the left wing and landing gear.
The pilot had limited experience on the type and did not appreciate that the engine was not developing full power during the take-off attempt.
The mixture control cable outer sheath was found to be broken, in such a position that it could randomly prevent full travel of the mixture control,
with subsequent reduction of fuel flow to the engine.
23 Nov 84
Cessna 210 L VH-EDE
Private
8421066
2210
Parkes NSW
54
2150
1000
Instrument rating class 4
Prior to departure for a nearby aerodrome the pilot decided to carry out some practice night circuits. He subsequently advised that all necessary
checks were completed for the first landing, however the aircraft landed with the gear retracted. When the aircraft came to rest the pilot noted
that the gear hydraulic pump motor was still operating. It was determined that the aircraft had touched down on the gear doors, whic h were
open at the time.
Although the main gear doors had completed their extension cycle, a defect in the gear control valve spool prevented the gear itself from
extending. Contamination of the hydraulic system was also evident, probably resulting from ineffective filtering of the fluid. The pilot had evidently
not checked the gear position indicator lights prior to landing.
17 Jan 85
Cessna A185 E VH-SWE
Senior Commercial
8511004
0900
Bendemeer Stn QLD
57
15000
Unknown
Agricultural class 1
After a normal touchdown a swing to the right developed. The swing was controlled initially with rudder but as brake became necessary the
pilot lost directional control. After the aircraft had swung through about 120 degrees the left wheel was dislodged. The left main axle assembly
had separated from the leg because a bolt had failed and a section of the broken bolt had jammed between the brake unit and the brake disc,
locking the left wheel. The locked wheel caused the remaining bolts to fail.
The bolt that failed was found to have been worn by fretting. The aircraft had only operated 20 hours since servicing was carried out to the
gear legs. The failed bolt had not been changed at that service.
16 Feb 85
Cessna 172-8 VH-CRB
Commercial
8521012
1520
Rylstone NSW
56
586
297
None
Witnesses reported that after take-off in hot and gusty crosswind conditions the aircraft did not climb away normally. It passed over the boundary
fence at a low height and then remained at about tree-top height for about one kilometre. The aircraft was then seen to turn sharply to the
left before disappearing from view. It was subsequently discovered to have struck the ground while in a steep nose-down attitude, and been
completely destroyed by a post-impact fire.
No evidence was found of any pre-impact defect or malfunction of the aircraft which might have contributed to the accident. The take-off
had been attempted with the ai rcraft approximately 200/o above the maximum allowable weight. It was considered that the combination of aircraft
weight and ambient weather conditions caused a significant reduction in the aircraft climb performance. The available performance was insufficient
to allow the aircraft to clear rising ground beyond the aerodrome boundary.
Cessna 150 M VH-PIG
Geelong Airport
Instructional - dual
C2N
Geelong Airport VIC/Geelong Airport VIC
8631016
23
1000
450
Instrument rating 1st class or class 1
with instrument rating
The flight was intended t~ be a revision exercise in ~ross-wind circuits and_landings. The first landing was completed satisfactorily and the
student subsequently advised that the flaps were raised to the take-off setting and full power was applied . However, the instructor reported
that only partial power was applied and he said to the student ' I've got the flaps'. The student believed the comment was 'Take it off' and she
responded by closing the throttle. The instructor took control and continued the take-off, but the tail tie-down ring struck the bound~ry fence
and the aircraft then collided with mounds of soil beyond the fence.
T~e investigation was unabl~ to resolve the appa~ent confusion wh ic~ existed in the cockpit with regard to the amount of power the student
applied or the phraseology which was used by the instructor. At the point where the student closed the throttle the instructor considered that
insufficient strip distance remained to stop the ai rcraft.
'
09 Mar
Cessna 172 M VH-BAW
Instructional - solo (supervised)
C1 N
1120
Walcha NSW
Walcha NSW/Walcha NSW
8621022
Student
34
26
13
None
At the conclusion of a dual chec_k flight, the ~tu dent landed the aircraft into a light north-easterly wind. The landing roll was completed about
half way_along the _853 ~etre strip? a_nd the pilot turned the aircraft around preparatory to taxiing back to the upwind threshold . The instructor
left the aircraft at this point, after briefing the student on the solo sequences he wished him to practice. Shortly afterwards, full power was applied
as the student commenced a take-off downwind . The aircraft failed to become airborne, collided with a fence and overturned.
The student was subsequently unable to give any reason for his decision to commence the take-off roll from other than the threshold of the strip.
Aviation Safety Digest 129/viii
07 May 85
Cessna 310 N VH-KOM
Commercial
8521028
1755
Cudal NSW
21
1035
227
Instrument rating 1st class or class 1
On the two previous landings the pilot noticed a nose wheel shimmy during the landing roll. As his next stop was at his company's maintenance
base, he advised the company of the problem. No nose wheel shimmy was noticed on landing, however, the aircraft was inspected by service
personnel. During the subsequent take-off, a violent shimmy developed and the pilot abandoned the take-off as the nose leg strut fractured.
The nose leg strut had failed from overload, most probably induced by the sudden onset of severe shimmy. The reason for the shimmy could
not be positively established.
Private
8521036
Piper 28 140 VH-MAM
09 Jun 85
None
Wedderburn NSW
56
1150
350
1411
As part of a club competition, the pilot was required to carry out a practice forced landing on the strip. On the downwind leg the height of the
aircraft was lowe~ than desired and the pilot adjusted his tracking in order to converge with the strip. A continuous turn from downwind to final
was attempted, during which the left wing suddenly dropped and the rate of descent increased. The pilot was able to regain partial control
but the aircraft struck the ground heavily and ran off the side of the strip, colliding with rocks and scrub.
After misjudging the height and distance to the selected touchdown point, the pilot elected to continue the approach. During the latter stages
of the turn onto final, the aircraft probably encountered mechanical turbulence, which resulted in control difficulties and an increased rate of
descent. It was likely that the pilot was influenced by the competition atmosphere existing at the time.
Aviation Safety Digest 129/ix
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
13 Jun 85
De Hav DHC2 VH-IME
Commercial
8521038
1600
Derrigo NSW 17W
28
3118
1380
Agricultural class 1
The pilot reported that shortly after take-off the elevator control jammed. He then noted that the horn end of the left elevator was hangi ng about
eight centimetres below the horizontal stabiliser. The load was jettisoned as the pilot prepared to land but increasing difficulty was experienced
in keeping the aircraft nose-up. On short final approach the left elevator separated from the aircraft but despite the lack of elevator control the
aircraft was landed w ithout further damage.
Investigation revea led damage to the leading edge of the left elevator horn . It was probab le that this area had been struck by an object whi le
the elevator was in the full nose-up position, i.e. with the horn pointing downwards. The object which caused the damage was not identified,
however the impact allowed the inboard hinge pin to become dislodged fro m its bearing. This in turn led to the jamming of the elevator controls
and to the subsequent detachment of the left elevator.
19 Jun 85
Piper 38 112 VH-UAL
Student
8521039
1130
Bankstown NSW
32
18
18
None
On return from his third so lo flight, the pi lot was attempting to complete a 180 degree turn in a confined area between two hangars. He positioned
the aircraft on the left extremity of the concrete apron prior to starting the right turn. The left outer wing section struck a vertical support for
the hangar located adjacent to the apron.
22 June 85
Robinson R22 VH-HBL
Private - helicopter
8511027
1057
Charters Twr 66SE
25
372
286
None
After helping to herd cattle to a yard , the pilot turned the helicopter and accelerated away along a creek. The helicopter struck a powerline,
which crossed the creek at right angles, and impacted the ground on its right side. One of the main rotor blades bounced backwards into the
cabin and almost severed the pilot's right foot.
The powerline was difficult to see against the background of the surrounding countryside. The pilot, who has no memory of the accident,
was aware of the location of the powerline but now believes he must have temporarily fo rgotten about its presence.
24 Jun 85
Conaero LA4 VH-EJX
Commercial
8511028
0955
Townsville OLD
47
8000
50
Instrument rating 1st Class or class 1
The student pilot was receiving instruction for an endorsement on the aircraft type. Following a touch and go landing, the instructor closed
the throttle to simulate an engine failure. The subseq uent landing was firm and the right wheel broke off. The aircraft ground looped through
180 degrees before coming to rest. Inspection of the gear leg revealed severe corrosion in the internal section of the leg.
The right maingear leg failed on landing due to corrosion. This corrosion apparently had not been detected during the most recent periodic
a nd major inspections, and there was no evidence that the bore of the maingear leg had been coated and sealed to prevent ingress of moisture.
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
20 Jui 85
Ryan STM VH-CXR
Commercial
8551016
1655
Wyndham WA
38
13600
140
Instrument rating 1st class or c lass 1
The pilot had been req uested to carry out an aerobatic d isplay over a fair being conducted at the local racecourse.
During the d isplay three spins were completed , with each being entered at about 1500 feet agl and recovery effected by 500 feet agl. The
d isplay appeared to be finished when the pilot made a low pass from behind the crowd at approximately 100 feet agl and then climbed out
for what looked initially like a normal entry to the circuit at nearby Wyndham Airport.
However, as the aircraft app roached 1000 feet agl it was observed to carry out a spin entry similar to that used on the three previous spins.
A spin to the left started and four turns were completed before recovery appeared to commence at about 200 feet agl. The aircraft struck the
ground before recovery was complete, still yawing to the left and with the nose attitude about 24 degrees below that required for level flight.
Whether or not the entry to the final spin was deliberate could not be determined. The pilot was not approved to carry out aerobatic manoeuvres
below 3000 feet agl, however, reports indicate that he had previously conducted low level aerobatic displays.
0 2 Aug 85
Beech V35 MK2 VH-DYS
Private
8541013
0738
Mataranka HS NT
62
1018
688
Instrument rating class 3
The pilot was conducting an around Australia holiday with three friends. On the day of the accident he intended flying the aircraft to Tindal,
a d istance of about 90 kilometres, to refuel prior to departing for his Queensland destination.
After the ai rcraft was taxied from the parking area to the threshold of the runway, witnesses reported hearing the engine being run-up. The
aircraft was then observed to take off in a no rth-westerly d irection and climb to about 150 feet above the strip. It then entered a steady, wings
level descent and collided with trees, 400 metres beyond and 100 metres to the left of the strip. The aircraft was destroyed by impact forces
and the ensuing fire.
The examination of the wreckage was hampered by extensive fire damage. However, with the exception of the vacuum pump, which was
probably unserviceable at the time of the accident, no evidence was found to suggest that the aircraft was not capable of normal operation.
There was no evidence to indicate that the pilot had suffered any sudden illness or incapacity, and the cause of the accident remains undetermined.
03 Aug 85
Hiller UH12-E VH-FFX
Commercial
8511034
0755
Hughenden OLD
35
4600
4550
None
At about 400 feet agl on climb, the helicopter suffered a partial loss of engine power. The pilot decided to use the available power to carry
out a landing on the airfield. At about 50 feet agl, the engine stopped and the aircraft was subsequently landed heavily, collapsing the skids.
The engine had seized. An inspection revealed that the condition of the engine was consistent with that of having been operated without
oil. There was no evidence of inflight oil loss or of any component failure which might have caused the loss.
When the engine began to lose power the helicopter was climbing at an ajrspeed of 60 knots. When the engine stopped the helicopter no
longer had sufficient performance to allow the successful completion of an autorotational approach.
05 Aug 85
05 Jui 85
Cessna 310 L VH-EDK
Commercia l
8521042
2218
Sydney NSW
56
4200
1000
Instrument rating 1st class or class 1
The pilot stated that he selected gear down but did not check for a down and locked indication. After havil'lg kept sufficient power applied to
land well down the runway, the pilot heard the gear warning horn immediately prior to touchdown, but co uld not prevent the aircraft land ing
with the gear retracted.
When the pilot p urchased the aircraft it had been fitted with an unguarded switch type circ uit breaker adjacent to the gear selector handle,
and a receptable for a remote gear switch . These modifications, which had not been approved by the Department of Aviation, were apparently
designed to allow the gear to be raised or lowered from outside the aircraft d uring maintenance checks when the aircraft was supported by
jacks. When selecting the gear down on this occasion, the pilot had evidently knocked the circuit breaker to the' 'off" position, removing electrical
power to the circuit. Neither the pilot nor the passenger, who held a c urrent Comme rcial Pilot Licence, realised that there were no aural or
aerodynamic indicatio ns associated with the extension of the gear into the airstream when the gear was selected down.
!I
13 Jui 85
Bell 47-G2 VH-SRE
Commercial - helicopter
8531018
1630
Balliang VIC
36
889
113
Instrument rating class 4
A group of pilots had travelled from a property strip to a nearby dam in order to complete training exercises on a float-equipped Bell 47 helicopter.
VH-SRE was not fitted with floats but had been used to ferry some of the pilots to the area. At the co nclusion of the training operation the
pilot arranged to ferry VH-SRE back to the property strip. After take-off a practice autorotation was conducted over the dam and was followed
by some unauthorised low flying in the vicinity. On arrival at the strip low level runs were performed along the strip with torque turns at each
end. Control of the aircraft was lost during the third of these turns and the aircraft struck the g round in a steep nose-down attitude. Fire broke
out on impact and eng ulfed the wreckage.
The subsequent investigation did not reveal any evide nce of a pre-impact defect or malfunction of the aircraft which might have contributed
to the accident. Sever_al of th~ pilots who observed the flight reported that the final manoeuvres performed were outside the normal operating
parameters of the hehcopte r, and were conducted at an unsafe he ight above the ground. It was, however, not possible to establish which of
the pilots was flying the aircraft at the time of the accident.
17 Jui 85
1920
Bell 206 B VH-FJR
Lancelin WA
helicopter
8551015
Instrument rating class 4 with flight
instructor
The pilot was positioning the helicopter before carrying o ut a medical evacuation from a ship. Prior to departure he had arranged to land on
the school oval at Lancelin, to refuel, and to have two vehicles positioned at the oval to provide lighting for the landing. During the subsequent
night app roach to the oval the helicopter collided with sand dunes.
Witnesses reported that during the approach the aircraft descended to a low altitude and disappeared from sight behind the sand dunes
before impact. An inspection of the wreckage revealed that apart from the altimeter no other faults were found with the aircraft that could have
contributed to the occurrence. Examination of the altimeter found that it was outside operating limits and d uring operation the aircraft was likely
to have been erratic in its indications. No such erratic indications were reported by the pilot or his passenger, who was also monitoring the altimeter.
The weather at the time of the occurrence was reported as overcast with light drizzle and a light wind. The visibility was 20 kilometres although
the night was dark and the o nly source of light in the area was from the town and the headlights of the two vehicles being used to light the
landing area. T hese conditions are conducive to the pilot suffering fro m visual illusions and it is possible that these illusions caused the pilot
to misjudge the altitude of the helicopter during the approach .
Aviation Safety Digest 129/x
41
12000
Commercial 7000
Cessna 182 Q VH.:fQJ
Private
8511036
1220
Townsville 128SSE
70
5121
2500
None
After touchdown, the pilot applied gentle braking but believed the aircraft was not decelerating. To avoid running off the end of the strip he
attempted a ground loop, however, the aircraft ran off the side of the strip and struck a derelict vehicle.
An inspection of the aircraft did not reveal any pre-existing defect that could have contributed to the occurrence. It is probable that the pilot
misjudged the speed of the aircraft and the distance to the end of the strip when applying the brakes during the landing roll. He was not wearing
the sash component of the seat belt and received facial injuries when he struck the control column during the collision with the vehicle.
09 Aug 85
Cessna 182 N VH-EKF
Private
8511038
1545
Burketown 25NW
36
220
57
None
Approaching the destination, the engine began to run roughly. As the aircraft was losing altitude the pilot selected a track running through
the scrub as the only suitable landing area. During the landing roll both wings struck trees and the aircraft ran off the track.
Rough running was caused by a worn carburettor float valve assembly, which in turn stuck closed and then too far open . Consequently the
engine first ran too lean, and then too rich. Once rough running began the pilot selected the mixture to full rich. This d id not resolve the problem,
but the pilot left the control in full rich instead of attempting to adjust the mixture through the full range available.
13 Aug 85
Cessna 182 H VH-KMM
Private
8551020
1027
Ord River HS WA
22
191
92
None
The desti nation was served by two landing sites - an ALA near the homestead and a licensed strip 12 kilometres to the north. The pilot elected
not to use either, but made an approach to a road adjacent to the homestead. The usable length of this road was 450 metres and the width
was less than 3 metres. The approach was made over a shed in light downwind conditions. Touchdown occurred about 200 metres from the
end of the road, and the pilot then attempted to go around. During this attempt the aircraft struck two wire fences before colliding heavily with
a tree. Fire broke o ut and gutted the wreckage.
The reason the pilot elected to land on the road and not one of the available ALAs could not be determined, although it is possible his decision
was influenced by one of his passengers.
Once the pilot elected to go around, it seems likely that he became concerned about avoiding a 10 metre high tree located d irectly ahead
of the end of the road. Witness reports and wheel marks indicate that a slight left turn was made almost as soon as the aircraft lifted off, presumably
to miss that tree. However, the left turn took the aircraft towards the line of fences which ran almost at right angles to the flight path, just off
the road. These fences wo uld have been difficult to see, and it is unlikely that the pilot was aware of their presence. Control of the aircraft was
lost when it struck the fe nces.
20 Aug 85
Cessna 182 K VH-KRH
Commercial
8541017
1720
Batchelor NT
22
218
30
Instrument rating class 4
As the fou r parachutists were preparing to jump from the aircraft, the reserve parachute of the parachutist who was standing on the wing strut
of the aircraft deployed. The reserve parachute was ejected forward over the leading edge of the wing causing the parachutist to be dragged
over the w ing before falling from the aircraft. Th is resulted in the buckling of the inboard section of the leading edge of the wing. During the
subsequent descent the parachutist released the main parachute which failed to fully deploy. In an effort to reduce his high rate of descent
he steered towards a large tree, contacting the branches before falling to the ground.
Sections of the reserve parachute were lost during the descent and it was not possible to determine the reason for inadvertent deployment
of the reserve parachute. The main parachute d id not fully deploy because one of the steering toggles and some suspension lines became
tangled with the streaming reserve parachute lines.
Aviation Safety Digest 129/xi
�Date
Time
Aircraft type & registration
Location
Age
24 Aug 85
1700
Cessna 310 L VH-KVY
Harden NSW
20
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
Commercial
23
8521046
Instrument rating class 4 with flight
instructor
About.20 minutes after take-off on the return leg of a charter flight and while cruising at 4500 feet amsl, the right engine suddenly lost all power.
The pilot reported that ~e was u~able to. restore P?Wer, and he .elected to land at a nearby ALA. From the downwind position a continuous
left turn was flown to align the aircraft with the strip. On short final approach the left engine also lost power and the aircraft touched down
short of the strip boundary. It ran through two fences and the nosegear collapsed after striking a dirt bank.
The flight was the first one in the aircraft type for the pilot in an unsupervised capacity. Investigations carried out at the accident site revealed
that there was adequate fuel remaining in the main tanks, although the auxiliary tanks were virtually empty. Both engines were started and
ran normally, and no fault was subsequently found with them that might have explained the power losses. The pilot did not have a detailed
knowledge of the fuel system, and it was considered likely that he had mismanaged the system.
270
26 Aug 85
Cessna 210 M VH-RQD
Commercial
8551021
1625
Pumnu WA
19
1281
71
Instrument rati ng 1st class or class 1
About 150 metres after touchdown, when the.brakes were applied, the a.ircraft began to veer to the right. Despite the application of heavy braking
the pilot was unable to stop the airc raft .and 11 ran off the end of the strip, through a gully and collided with a tree. While the aircraft was being
vacated, ~ fire was noticed amu.n d the right whe!'.I area: This fire ~as controlled by use of the portable extinguisher. A subsequent examination
of the strip revealed marks 1nd1callve of heavy, intermittent braking forces being applied to the right wheel du ring the landing roll.
Insp ection of the a.ircraft revealed that the left brake had failed due to fatigue cracking of the brake hydraulic line. The cause of this fatigue
could not be determined.
02 Sep 85
Cessna 182 Q VH-DER
Private
8521048
1118
Wagga NSW
60
1055
444
None
During his pre-flight inspection, the pilot detected water in the fuel samples from the various drain points. Further samples were taken until
no trace of water. was evident. The subsequent flight of almost 90 minutes was uneventful, until the pilot selected full flap on final approach
to land. At this point the engine l<?s~ all power and dur!ng the ensuing forc.ed landing the aircraft collided with a fence post. lnv~stigation revealed
that the fuel caps were n~t providing adequate sealing, and a substantial amount of water remained in the fuel system. Prior to the flight the
aircraft had been parked 1n the open for some days and considerable amounts of rain had fallen.
!he water in the fuel system had most probably been trapped in wri.nkles in the left fuel bladder, and had entered the engine following the
attitude chan11e associated with selection of full flap. Du.ring the previous scheduled maintenance, a mandatory inspection and leak test of
the fuel tank filler caps was not earned out. The owner/pilot had frequently found evidence of water during pre-flight inspections but had not
specifically instructed the maintenance organisaHon to investigate and rectify the problem.
'
06 Sep 85
Piper 32 TR300T VH-CXX
Private
8521049
1205
Mudgee NSW
Unknown 145
30
None
Shortly .after ~ake-off a lo~d banging no.ise was heard from th.e inboard area of the right wing. The pilot elected to fly a low level circuit and
land to investigate the noise. On short final approach heavy sink was encountered, and despite the application of power the aircraft touched
down ~bo~t 100 metres short of lh!'. runway. It ran through the airport boundary fence and came to rest near the flight strip with the gear collapsed.
lnvesllgat1on revealed that a section of the door seal had become unstuck and had trailed in the slipstream, beating against the door.
The. pilot ha~ believed that the aircraft had suffered a s~rious malfunction. and was anxious to land as soon as possible. Her husband, who
o~cup1ed thi: right front seat, was a more expenen~ed pilot. How~ver, he did not offer to take control of the aircraft. It was possible that the
a1rsp!'.ed dunng the approach was less than the optimum. When sink was encountered, the power and control inputs which were applied were
1nsufflc1ent to prevent the aircraft striking the ground in a semi-stalled condition.
06 Sep 85
1245
Avnspier Robin-R2160
VH-NRK
Private
8521050
The Oaks NSW 4NE
30
152
8
None
The pilot was conducting a flight in the local training area. He reported that as he applied power to climb from 2000 to 3000 feet amsl the
engine suddenly stopped completely. Efforts to regain power were unsuccessful and during the ensuing forced landing the right wing struck
a dead tree.
. A ~iece of ~il~stic material was found to be ~l~cking the main d isc~arge tube of the carburettor. Spectroscopic analysis indicated that the
s1last1c was s1m1lar to that used to seal the radio inspection hatch against water ingress. It was probable that when the hatch was opened for
radio mainte nan~e some of the sealing compound fell into the engine area below. Maintenance records revealed that the carburettor bowl was
removed for repair on the day preceding the accident, however it could not be positively determined whether the silastic entered the carburettor
on this, or on some other occasion.
07 Sep 85
Rand KR2 Turbo VH-LLL
Private
8521051
1230
Camden NSW 10NE
40
400
70
None
T.he pilot repo.rted that while the ai;craft wa.s in cruising flight it suddenly began to vibrate heavily. The pilot closed the throttle but the violent
v1brat1on continued. The surrounding terrain was generally unsuitable for a forced landing, and in the latter stages of an approach towards
a small paddock the right wing struck a tree. The aircraft then dived into the ground and was destroyed. It was subsequently determined that
more than half of one of the two propeller blades had separated in flight.
The propeller h~d failed as a res~lt of fatigue cracking. A similar crack was discovered in the other blade. The propeller had only operated
for 42 hours tot~I time before the failure occurred. During the approach to land, the pilot's vision was affected by the violent vibration caused
by the propeller imbalance. As a result, he was unable to accurately judge his flight path between two trees on the edge of the selected paddock.
23 Sep 85
Aerocdr 500 A VH-ICE
Commercial
8551024
1702
Port Hedland WA
38
3448
100
Instrument rating 1st class or class 1
Afte; the .gear w~s selected ~own , no do~n indication was received for the right gear leg. The pilot decided to divert to Port Hedland where
engineering advice was available. When 11 was decided that all the options were exhausted, the pilot landed the aircraft. As the right wheel
contacted the ground the leg collapsed and the aircraft slid to a stop.
The right ma!ngear ret:act.ram had become disconnected from the body of the gear leg when an improperly secured clevis caused the failure
of the body fitting to which 1t was connected. The components had been incorrectly assembled during previous maintenance.
25 Sep 85
Cessna 152 VH-FUR
Student
8511043
1205
Archerfield OLD
26
15
15
None
On the third landing of the exercise, the pilot stated that the aircraft touched down on all three whAels and bounced. The aircraft was then
observed to land on the mainwheels then the nosewheel. The nosegear collapsed and the aircraft skidded for 33 metres on the lower engine
cowl before coming to rest.
After the aircraft bounced the pilot did not take any corrective action prior to the second touchdown.
Aviation Safety Digest 129/xii
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
04 Oct 85
Piper 24 400 VH-EDM
Private
8531019
1204
Launceston TAS
36
340
60
Instrument rating class 4
The pilot reported that as the aircraft became airborne, he noticed a loss of engine power and believed the aircraft may have touched the ground
after the landing gear was selected up. He was subsequently unable to obtain a gear down and locked indication, although the gear appeared
to ground observers to be fully extended. During the landing roll the right main gear collapsed.
The right gear did not fully retract or extend because of damage sustained by the retraction mechanism, probably as a result of ground contact
after the down lock had been released. The cause of the partial power loss reported by the pilot was not determined.
05 Oct 85
Private
8511046
Jodel D9-A VH-SJZ
1130
None
Gatton QLD
58
242
442
After completing a circuit, the aircraft was flown along the strip at an altitude of 50 feet. An airspeed of 50 knots was maintained with a low
power setting. Towards the end of the strip the pilot attempted to apply climb power but the engine did not respond . The pilot selected a clear
area straight ahead and landed the aircraft. During the landing roll the aircraft struck a tree stump which was hidden in the tall g(ass.
The contact spring was missing from the distributor cap, which caused the output from the magneto to short circuit to ground and as a result
of which the engine lost power.
09 Oct 85
Hiller VH12-E VH-AGL
Commercial - helicopter
8531020
1415
Cape Portland 10S
31
372
235
None
The pilot reported that while he was hovering the helicopter at about 25 feet agl, the engine suddenly lost power. He placed the helicopter
in an autorotation but maintained the throttle setting that had been set while the aircraft was hovering. Just as the skids were about to contact
the bushes, the engine momentarily regained power. The helicopter impacted the ground on its right hand side and fire broke out. Both the
occupants escaped from the helicopter before it was destroyed by fire.
An examination of the engine revealed that both valves in one cylinder had been striking the top of the piston, and the inlet valve was badly
chipped. It was likely that when the inlet valve failed , a flashback occurred in the induction system, resulting in a complete loss of engine power.
The engine regained power momentarily when the mixture build-up again reached a combustible level. Had the pilot closed the throttle when
the engine initially failed, the sudden power surge should not have affected his ability to control the autorotation.
Cessna 150 G VH-KPP
Private restricted
8551027
09 Oct 85
120
None
1030
Nookawarra HS WA
20
128
After the aircraft had been airborne about 90 minutes, the engine began to run roughly. The pilot's attempts to restore full power were unsuccessful
and the engine stopped. During the latter stages of the subsequent landing roll, the aircraft struck a dead tree and damage was caused to
the left wing and lower engine cowl.
Before commencing the flight the pilot had checked the fuel contents gauges, they indicated that both tanks were about half full. He did
not, however, visually check the fuel quantity in each tank nor did he specifically plan the duration of the flight. The loss of engine power was
caused by fuel exhaustion.
12 Oct 85
Hughes 269 C VH-SBR
Commercial - helicopter
8551028
1410
Kununurra 97NNE
28
190
80
None
The pilot was requested , by the passenger, to land the helicopter on the mud flats to the north of Kununurra. He decided to make a run on
landing as he believed he may have difficulty in hovering the helicopter. As the aircraft approached the touchdown point, the pilot allowed it
to yaw into wind, but it contacted the ground still moving sideways. The left skid caught in the dry mud and the helicopter rolled onto its side.
The pilot was inexperienced in the operation of helicopters and had experienced difficulty in hovering the aircraft when he departed Kununurra
that morning. The approach to land on the mud flat was poorly planned and the pilot misjudged the altitude of the aircraft during the turn into wind.
14 Oct 85
1000
Robinson R22-ALPHA
VH-HBQ
Private - helicopter
8541018
Warooka SA 5S
37
802
99
None
The pilot positioned the helicopter on the downwind leg of the circuit at an altitude of about 300 feet agl. The wind was gusting between 30
and 35 knots. Towards the end of the downwind leg the pilot noticed that the helicopter was yawing to the right and that a high rate of descent
had developed. The pilot applied full power and lowered the collective slightly. The helicopter continued to descend and the pilot applied full
up collective, but the helicopter struck the ground heavily and bounced. On the second touchdown, the tail rotor struck the ground and broke off.
At the point of turning downwind, the helicopter was being flown at an indicated airspeed of 30 knots. On downwind it is probable that the
pilot unwittingly allowed the indicated airspeed to decrease well below translational lift because of the rapid increase in groundspeed, resulting
from the 30 knot tailwind. Had the helicopter touched down at zero indicated airspeed , when travelling downwind, it would have contacted the
ground at 30 knots groundspeed and travelled a considerable distance along the ground. However, the helicopter travelled only about 12 metres
after the first point of touchdown. This indicates that the helicopter was probably flying backwards in relation to the airmass in which it was
flying, prior to touchdown. In such a situation the power available would not have been sufficient to arrest the rate of descent.
Commercial - helicopter
8551029
Hughes 269-C VH-MSL
26 Oct 85
560
None
1705
Karratha WA 61SE
24
750
As the helicopter was cruising at 1000 feet agl , the engine suffered a complete loss of power. An autorotation was commenced and the pilot
headed the aircraft towards a clear area to land . At the completion of the landing flare, the heel of the skids dug into the ground and the main
rotor blades struck the tail boom.
An examination of the engine determined that the fuel regulator diaphragm stem had suffered a fatigue failure. This allowed the diaphragm
to shut off fuel flow to the engine. The pilot elected to carry out a zero speed touchdown because he believed that the terrain was unsuitable
for a run-on landing, but he misjudged the landing flare.
10 Nov 85
Westland Scout VH-NVY
None
8521062
1950
Schofields NSW
32
None
The helicopter had been transported by road to Schofields to form part of the static display associated with an air show. Although it was airworthy,
the helicopter was the on ly one of its type in the country and had not been approved for flight at the show. At the conclusion of the show, one
of the persons responsible for the restoration of the aircraft became concerned for its security, and he elected to hover taxy the helicopter a
short' distance onto Naval property. He had never received any formal helicopter flying instruction and control of the aircraft was lost shortly
after it became airborne. The helicopter struck the ground while moving backwards and came to rest on its side some 60 metres from the
parked position.
Aviation Safety Digest 129/xiii
�11
, ~,
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
13 Nov 85
Beech 95 B55 VH-MLC
Commercial
8521063
1103
Hunthawang NSW
54
16285
5215
Instrument rating 1st class or class 1
Shortly befor_e the aircraft landed a tractor had finished slashing the strip. The driver had not noticed any soft areas, and the strip appeared
to be of a uniform colour. As the aircraft decelerated to about 20 knots during the landing roll, the nosewheel suddenly broke through the
strip surface and sank to a depth of some 30 cm. Shortly afterwards the wheel snapped off near the bottom of the strut, which then folded
rearwards and the aircraft skidded to a hall on its nose.
'
The strip was in regular u.se, however this had been the first landin9 since isolated heavy rain had fallen over the area two days previously.
It was probable that the rain had affected a small section of the strip, but not to the extent where the soft patch was detectable by aerial
or ground inspection.
13 Nov 85
Robinson R22 VH-UXE
Commercial - helicopter
8551031
1555
Whim Creek WA 37S
55
12259
350
Agricultural class 1
The pilot was mustering a herd of cattle across a tree-lined dry creek bed, when the mob scattered. He positioned the helicopter at tree
top height to block the escape of the cattle from the creek. The rotor RPM rapidly decayed and the pi lot was unable to prevent the aircraft
sinking and landing heavily on the bank of the creek.
The P!lot had attemp~ed t.o brin\:! the helicopter to a hover in a 15 knot dow.nwind. At the time the helicopter was being operated near to
the maximum all up weight in ambient temperatures of about 45 degrees cels1us. Insufficient power was available to maintain flight in these
cond1t1ons.
16 Nov 85
Piper 25 235 VH-SPB
Commercial
8531023
1145
St Arnaud VIC 24N
38
3300
2450
Agricultural class 2
At the end of each spray run, the aircraft was flown under a power line before the turn to change direction was commenced. Several runs
had been. completed when the pilot climbed the aircraft to commence the turn and the aircraft collided with the power line. The pilot dumped
the remainder of the load and the aircraft continued to fly, trailing the power line. After travelling a short distance the aircraft apparently
stalled and struck the ground in a nose down attitude. A fire broke out and completely engulfed the wreckage.
The pilot subsequently advised that he had temporarily overlooked the presence of the power line. It was probable that on this particular
spray run a pole supporting the wire was no longer in the pilot's field of vision. The severed wire became entangled around the right wing
and lift strut, resulting in bending of the strut and probably inducing stalling of the wing.
17 Nov 85
Beech A36 VH-RNM
Private
8531024
1910
Lilydale VIC
37
200
26
None
On arrival in' the destination area the pilot encountered deteriorating weather conditions, including rain and turbulence. Strong sink was
ex~eriE'.nced on the base leg of the circuit and the pi lot found it was necessary to increase power and raise the landing gear in order to
maintain adequate control of the aircraft. The approach was continued but the pilot forgot to re-select the gear down. The warning horn
sounded just before ground contact and the aircraft slid to a halt on the strip.
18 Nov 85
PA36-375 VH-JND
Commercial
8521064
1200
Griffith NSW 26SW
30
5700
200
Agricultural class 1
The pilot was carrying out the fi rst spraying run in the particular paddock. Towards the end of the run he was distracted when a large flock
of birds suddenly flew up in·front of the aircraft. The pilot descended in order to fly under the birds, but temporarily forgot that there was
a power line in !he vicinity. A_s he pulled up at the end of the run , the main gear snagged the wire. The wire cutters fitted to the gear did
not sever the wire and the aircraft subsequently struck the ground 82 metres beyond the run of the power line.
21 Nov 85
Beech B24 R VH-DJD
Private
8511051
1510
Emerald OLD 35N
35
3bb
16
None
After h_aving inspected a property, the pi lot and hisyasseng_ers returned t_o the aircraft _to prepare for departure. A storm was approaching
the strip from the north and a 10 to 15 knot crosswind prevailed at the strip. A take-off into the east was commenced, the aircraft became
airborne and as it crossed the upwind end of the strip, it was affected by a sudden gust of wind. The aircraft yawed to the right lost altitude
and struck the ground before coming to rest in a ploughed paddock.
'
_At the time_of the att~rr:ipted take-off the loca~io n of the approaching storm was conducive to the presence of strong downdraughts or possibly
m1crobursts 1n the v1cin1ty of the stri p. The pilot elected to commence the take-off because he was concerned that heavy rain at the strip
would have rendered it unserviceable.
22 Nov 85
De Hav 82 VH-MDV
Commercial
8521065
0740
Camden NSW
60
3000
200
Instrument rating 1st class or class 1
The ~i rcraft had been refurbished during the prec.eding months, and at t~e completion of th is work the pilot intended to carry out a short
te.st flight. He subsequently repor~ed that as soon as the a1rc_raft became airborne after a normal take-off roll, it veered sharply and the right
wing dropped. Corrective control inputs had no effect, the wing and propeller struck the ground and the aircraft overturned, coming to rest
about 200 metres from the start of the take-off roll.
The surface w~nd was reported to be varying up to 30 degrees off the runway direction, and gusting up to 15 knots. Because of the degree
of damage sustained however, it was not possible to determine whether the wind conditions or the rigging of the aircraft was the major factor
contributing to the accident.
22 Nov 85
Cessna 172 N VH-UWD
Private
8511052
1030
Quilpie OLD 32SSW
33
107
77
None
At about. 200 feet a_gl after t<;ike-off, the engine. began to vibrate and lose power. The pilot turned the aircraft to the right to position over
more suitable terrain. The aircraft was stalled into small trees and bushes before touching down heavily on the nosewheel which broke
off. The aircraft then overturned and came to rest inverted.
'
The power loss was caused by two engine exhaust valves sticking open. Although the valves were found to have been set at the minimum
recommended clear!'lnce a bui!d up of combustion re~id ue w<;is pres_ent w~ich probably restricted valve movement. Operations in high ambient
temperatures involving slo"." flight and. re~ uced enQine cooling at rich m1x.tures can promote a combustion residue build up reducing valve
guide clearance and resulting valve sticking. The aircraft had been operating in the western Queensland summer conducting sheep survey
operations.
Aviation Safety Digest 129/xiv
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
23 Nov 85
Cessna 402-C VH-UEZ
Senior commercial
8541024
1345
Pulparee SA
25
3900
779
Instrument rating 1st class or class 1
The flight had been arranged to take passengers and freight from Pulparee, a seismic exploration field camp, to Brisbane. Just after the
aircraft became airborne the right wing struck two men who were working on the top of the cabin of a truck. A section of the right wing
was torn from the aircraft, however, the pilot was able to land the aircraft at Pulparee without further incident. The truck was located approximately
24 metres to the right of the centreline of the strip.
From the point where the take-off was commenced the strip met the criteria for an authorised landing area. The vehicle was struck 1110
metres from the start of the take-off and about 200 metres after the aircraft became airborne. At the time the surface wind was gusting from
the left and there were dust devils in the area. Shortly after becoming airborne, the pilot felt that the aircraft was not performing normally,
and he looked into the cockpit to check the instruments. During this time, the aircraft diverged from the strip direction and the right wing
dropped. The pilot heard the impact as the men were struck, and then looked out to see that the right wingtip had been severed.
. No evidence was obtained to indicate that the aircraft was not capable of normal operation. The pilot had been working in direct sunlight
in temperatures of about 40 degrees Celsius for four hours prior to the flight. It was therefore likely that he experienced some degree of
heat stress. One of the effects of heat stress is that the time taken to integrate information is increased. It is considered probable that when
th_e pilo~ looked at his instruments he required longer than normal to assimilate the information presented by the instruments. II was during
this period that the aircraft was affected by the crosswind and possibly a dust devil and drifted off the intended flight path while travelling
the distance to the truck. It was probable that the correct climb attitude was not maintained.
30 Nov 85
Ayres S2R-T15 VH-WBE
Commercial
8521067
1830
Moree NSW 4N
36
6514
2100
Agricultural class 1
The pilot intended to spray a cotton crop. A power line crossed the area at an oblique angle, and at the point where the aircraft passed under
the wire there was a head ditch one metre high, dividing two paddocks. On the first spraying run the pilot misj udged the clearance under
the wire and the mainwheels struck the top of the ditch. The aircraft remained controllable and an uneventful landing was subsequently
carried out at the destination aerodrome. Damage was confined to the gear truss points and shock absorbers.
05 Dec 85
Beech C23 VH-IHP
Student
8511055
0830
Cairns OLD
56
78
30
None
The pilot was carrying out a period of solo circuit training, after having completed three check circuits with an instructor. On the second
landing, the aircraft bounced, then touched down again heavily on the nosewheel. The nosegear leg failed due to overload and the aircraft
ran off the runway.
The pilot was attempting to carry out a short field landing and misjudged the flare. He stated that following the bounce, the nose of the
aircraft dropped and he was unable to regain the landing attitude before the nosewheel struck the runway.
This accident was not the subject of an on-site investigation.
13 Dec 85
Cessna A188B A1 VH-UDV
Commercial
8531026
1200
Koo Wee Rup 18NE
42
7500
3000
Instrument rating class 4
The pilot was spraying a potato crop in a paddock which had a power line running along one boundary. Spray runs were conducted at right
angles to the wires, and the pilot was flying under the wires on each run. At the end of one run the pilot pulled up, conducted a procedure
turn, and was then slightly distracted by noise on his CB radio. While adjusting the squelch on the set, he forgot the presence of the power
line and the aircraft struck the wires about 32 feet agl. The aircraft remained under control and the pilot was subsequently able to make
a normal landing at his destination strip.
Commercial
15 Dec 85
Comwlth 28 C VH-SSY
8531027
1700
Wangaratta VIC
58
2254
4
None
A fly-in had taken place to the site of an aviation museum. At the conclusion of the organised activities, it was decided to position the Ceres
in such a manner as to allow it to be photographed against the background of the museum hangar. Shortly after start-up, the engine stopped
of its own volition, and after the restart it faltered again prior to normal take-off. During the flight the engine again lost power and the pilot
was committed to a forced landing. The only area su itable for landing had a group of Tiger Moth aircraft at the far end, and after touchdown
the pilot initiated a ground loop in order to avoid these aircraft. The left gear leg collapsed and the aircraft slewed to a stop short of the parked aircraft.
Examination of the fuel system revealed that seals in the hand-operated fuel pump had deteriorated and cracked. This allowed air to enter
the system and cause fuel starvation.
19 Dec 85
Cessna 182 P VH.:rSA
Private
8511057
1625
Miles OLD 2E
26
715
None
As the aircraft was being taxied for take-off, the nosewheel struck a small termite mound. The nosegear was broken off and the aircraft
came to rest on the lower engine cowl.
The strip was normally slashed every two weeks, a process which cut the grass and removed termite mounds. Because of recent dry
weather which had inhibited grass growth , slashing had not been done for 4-5 weeks, and small termite mounds had built up. Several of
these mounds were not noticed during the pre-fl ight strip inspection. The low colour contrast between the mounds and the strip surface,
and the sun angle at the time, made the mounds difficult to see.
20 Dec 85
Cessna A 152 VH-THF
Student
8531028
1700
Tyabb VIC
34
12
12
None
Following a period of dual instruction, the student was authorised to conduct a series of solo circuits and landings. On the first approach
he lowered 30 degrees of flap and the aircraft touched down normally. After travelling about 50 metres, the aircraft veered sharply to the
left, ran off the side of the strip, and came to rest in a shallow ditch just outside the boundary of the strip.
The approach and landing had been conducted in light crosswind conditions. While compensating for these conditions, the pilot had probably
inadvertently applied excessive forward pressure to the control column and a "wheel-barrow" situation developed. The elevator trim was
found to be in the take-off position, which would have compounded the nose-down tendency during the landing roll .
Private
Cessna R182 VH-MQG
8511059
21 Dec 85
137
34
None
Bowen OLD
0815
19
On landing the aircraft bounced about four times before the nose gear broke off. The aircraft overturned, coming to rest on the runway.
Gusty wind conditions prevailed at the time of landing. When the aircraft bounced on the initial touchdown , the pilot did not take suitable
corrective actions and a porpoising situation developed until the nose gear failed.
Aviation Safety Digest 129/xv
�l
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
Number
26 Dec 85
Piper 25 235 VH-CKL
Commercial
8531029
1530
Meander TAS
37
2000
900
Agricultural class 1
The pilot was spraying a small paddock, to the south-east of which the ground rose steeply. All spraying runs were being conducted towards
the south-east, with the pi lot carrying out left hand orbits at the end of each run in order to reposition the aircraft. However, manoeuvring
in this manner was taking the aircraft close to houses in a noise sensitive area. The pilot therefore decided to carry out a procedure turn
and conduct a run into the north-west. About half way around this turn the aircraft lost performance, probably as the result of a downdraught,
and then stalled at about 100 feet above the ground. There was insufficient height avai lable for the pilot to effect recovery and the aircraft
struck the ground in about a 30 degree nosedown attitude.
The pilot subsequently advised that he was aware that downdraughts were likely to be present in the prevailing conditions. However, he
had been concerned to avoid the noise sensitive area, and had not considered the possibility of downdraughts as he manoeuvred over rising
terrain. When he was attempting to recover from the stal l situation, the pilot had not dumped his load because there were valuable animals
in the paddock below the aircraft.
Looking after your passengers
-
/
/I
Pazmany PL4-A VH-URR
27 Dec 85
Private
8541026
0746
Parafield SA
56
300
1
None
The pilot had built the single seat aircraft himself and had previously only flown it on one occasion. After completing the first circuit, the
aircraft was taxied back to the threshold and the second take-off commenced. Just after lift-off the aircraft was observed to pitch nose up.
The right wing dropped and the aircraft turned to the right before impacting the ground.
When the aircraft tail came up during the take-off roll, the pilot became concerned that it was too high and that the propeller might strike
the ground. In attempting to avoid this, excessive back pressure was applied to the control column. The aircraft became airborne prematurely
and then stalled .
Burkhart Astir VH-WQL
Glider
8521076
28 Dec 85
1930
Parkes NSW 30N
18
80
12
Glider
The purpose of the flight was to achieve the cross-country distance requirements for the upgrading of the pilot's qualifications. He had been
ai rborne for over 6 hours when fu rther lift could not be found and an outlanding became necessary. While manoeuvring towards the selected
area, the pilot misjudged the strength of the wind and was forced to turn onto final approach at a low height above the ground. During the
turn the right wingtip struck a tree and the aircraft rotated about 110 degrees to the right before striking the ground.
It was considered likely that the pilot's performance was affected by fatigue resulting from the length of the flight and his exposure to
direct sunlight for a period of more than 10 hours.
This accident was not the subject of an on-scene investigation.
41
29 Dec 85
Cessna P206 VH-MYD
Commercial
8521007
1530
Medlow Bath NSW
23
336
17
Instrument rating class 4
During the pre-landing c hecks, the pilot noted that no pressure was available from the left brake pedal. The strip has a slight slope, and
the pilot elected to land up the slope in light quartering tailwind conditions. The aircraft bounced twice after touchdown and the pilot commenced
a go-around. The aircraft veered off the strip and collided with several trees before coming to rest 50 metres from the centre of the strip.
The left brake had lost pressure because a worn seal had allowed air into the brake line. The pi lot advised that the brake problem did
not affect the selection of landing direction. It was considered that directional control was lost during the attempted go-around when the
aircraft was affected by a wind gust at a critical stage of the flight.
30 Dec 85
Cessna 152 VH-SDT
Student
8521078
0950
Cooranbong NSW
27
21
8
None
Following a dual check, the pilot was authorised to carry out three solo circuits and landings. The first of these was completed satisfactorily,
but on the next landing the aircraft bounced and the pi lot applied full power in order to go around. Shortly afterwards the aircraft sank, struck
the ground with the nosewheel and the left wing, and overturned. The pilot later advised that he had held the control column fully back
during the go-around attempt , and he had not raised the flaps from the fully lowered position.
31 Dec 85
Transav PL12 VH-M LJ
Commercial
8531030
1000
Bridgport TAS 10W
22
1820
1000
Agricultural class 1
The aircraft was being operated from a strip which had been cleared in a hay paddock. The pilot was aware that the strip was of marginal
length and had therefore reduced the load to be carried. On take-off, the aircraft accelerated normally to about 40 knots but the performance
then appeared to stagnate. The pilot attempted to dump the load, but only partial dumping was achieved before the right main gear struck
a fence post as the aircraft became airborne. The impact displaced the gear, however the aircraft remained under control and the pilot diverted
the ai rcraft to a more suitable aerodrome. The right main gear became completely dislodged during the landing.
A subsequent inspection of the stri p revealed that it had a soft sandy surface, covered with short and thick grass. Heavy rain had fallen
in the area during the night and early morning, and the grass was very wet at the time of the take-off. When calculating the load he could
safely carry from the strip, the pilot had not appreciated the degree to which the surface conditions would affect the take-off performance.
Aviation Safety Digest 129/xvi
Evidence fro m air safety investigations ind icates that it
is t he well- pr epared passenger who is most likely to
esca pe from a wrecked aircra ft, or to take the correct
actions during a n infl ight emergency. In this context,
the ex tent to which passengers are well prepared is
closely r elated to the advice given to them by the pi lotin-com ma nd during h is prefligh t briefing.
Amon g t he m an y responsibilities attaching to the
p osition of pilo t-in -command is that for passenger
safety: as the re leva n t Air Navigation Regulation states,
' In addition to being responsible for the operation and
safety of the a ircraft during flight time, the pilot-incom ma nd shall be responsible for the safety of persons
a nd ca rgo carried a nd safety of members of the crew'.
An important com ponen t of this responsibility is the
passenger briefing, wh ich should be an integral part of
the pilot's prefligh t activities, regardless of whether th e
intended fli ght is with fare -paying passengers on an
internatio nal jet , o r with famil y or friends in a singleengi ne GA aeropla ne.
Pr inted below is a list of items which GA pilots should
consider befor e g iving their passenger briefing. T he list
is comprehensive an d clearly too long to be used on
every fl ight. It is up to the pi lot to decide what is
appropri ate for an y particular occasion.
For all briefi ngs a pilot should use simple l anguage
as some phrases (e.g . leading edge, trailing edge, port,
starboard) m ay be unfamiliar to his passengers. I t may
a lso help passengers who have flown in passenger jets
b u t not in ligh t aircraft to highlig ht some of the m ain
differences between regular public transport and
GA flyi ng .
Before boarding
• Advise passengers to beware of other aircraft (and
their propellers) when going to and from the
a ircraft .
- Propellers and helicopter rotors are ex tremel y
hazardous and should be a voided at all times,
even when stationary.
- Rotating propellers and rotors (particularly tail
rotors) may be very hard to see, especially from
the side .
The hazard can be masked if other nearby
aircraft have engines running.
- Propeller-driven aeroplanes must always be
approached and left from behind the wi ng. The
only exceptions are a sm all number of types with
pusher propellers or entry doors forward of the
wing. W ith these aeroplanes the engine(s) must
always be stopped when passengers are boarding
or leaving. Passengers must never step forward off
the wing leading edge towards a propeller .
• Someone must be in charge of ch ildren, particularly
small ones, both in flight and when going to and
from the aircraft.
• Beware of the hazards u nder the wi ngs of high winged aircraft , su ch as struts, and pitot tubes.
• Passengers should be instructed on the use of any
steps or hand -holds. If there are wing walk-ways,
make sure that passengers know where they must
not step because of the risk of holed fabric or
dented skin.
• Passengers should know how to operate external
door catches and locks. A door suddenly opening,
Aviation Safety Digest 129 I 13
�Extra precautions when ditching
•
•
•
•
•
•
helped by the wind, can cause injury to passengers
and crew or damage to the door hinges.
Luggage must not be overweight, must be properly
stowed and should not contain hazardous items,
such as:
- flammable liquids and solids, e.g. fire lighters,
paint
- explosives, e.g. fireworks, toy gun caps
magnetic materials, e.g. loudspeakers
compressed gases, e.g. camping gas, aqualung
cylinders
- corrosives, e.g. acids, alkalis, wet-cell car
batteries.
Advise passengers if there is any restriction on
smoking in or near the aircraft.
Passengers should wear sensible clothing, e.g. bare
limbs or thin nylon are hazardous if there is a fire.
In winter, warm clothing should be avai lable for use
in any diversion or forced landing; high ground in
winter is no fun in shirtsleeves.
Advise on the effect of flying when ill , or when
recovering from illness or a cold.
Make sure your passengers know they must not fly
when they are drunk.
Tell passengers not to distract the pilot at critical
times, e.g. by asking questions in the middle of the
Vital Actions, or by interrupting the pilot's
navigation or monitoring of the flight by excessive
conversation.
When on board
Make sure your passengers:
• Are fami liar with how to fasten , adjust and release
seat belts or harnesses. Suggest they keep them
fastened throughout the flight in case of turbulence.
• Know about the closing, locking and opening of
doors or canopy. Locks and handles should be le ft
well alone once the doors are closed.
• Do not obstruct the controls with objects such as
cameras, handbags, knees or feet, do not put
metallic or magnetic objects near the compass, and
do not interfere with the controls in flight.
• Can use the intercom, if fitted, and know how to
communicate if there is no intercom.
\
A
B
--c
LIFE RAFTS
Decide which passenger is responsible for getting the
life raft out - it is too late when the aircraft has sunk
with it still in the aircraft. The life raft should not be
left unsecured on top of the baggage where it can strike
people's heads during deceleration. Passengers should
know how to inflate the life raft and what emergency
equipment it contains, e.g. fluorescent dye , flares.
Tell passengers to swim away from the aircraft
before inflating the life raft so that there is no danger
of its being holed. When inflated , make sure it does
not blow away, leaving some or all of the passengers
still in the water.
Above all, impress on your passengers not to panic.
There will be a lot of water flying around, perhaps
through a broken windscreen, but there is usually at
least one to two minutes to get out.
Summary
Passengers are your responsibility, so make sure you
look after them prope rly •
Lap-sash belts
D
Emergencies
Forced landing and ditching
Before flight, instruct passengers that they should brace
themselves if impact or ditching appears likely. There
are two prime reasons for this:
- to reduce secondary impact which may cause
inju ry
- to reduce flailing .of the body.
Secondary impact can be reduced by placing the
body, particularly the head , against the surface it
would be likely to strike during impact. Flailing can be
reduced by flexing, be nding or leaning the body
forward over the legs.
Where there is room , passengers should adopt
position A, resting their heads and chests against their
legs. Flailing is reduced by grasping the legs or ankles,
or by wrapping the arms under the legs. If there is no
room for position A, passengers should put their heads
and arms against the sea t or bulkhead in front of them
as per position B. In aft-facing seats, adopt position C.
Front-seat passengers with upper torso restraint should
LIFEJACKETS
Before flying over water in a single-engine aircraft,
make sure that passengers are wearing lifejackets, know
how to inflate them and how to use any ancilliary items
e.g. light , whistle. If the aircraft is twin-engine, point
out the location of lifejackets and how to put them on.
If one engine stops, get the passengers to put on their
lifejackets - it is now a single-engine aircraft.
Impress on your passengers that lifejackets should
NOT be inflated until outside the aircraft.
Passengers unfamiliar with light aircraft
Those who have not flown before , or who are more
used to package holiday jets, may find a light aircraft a
very different experience. No one wants an early return
with a sick or frightened passenger. Chat to them
beforehand about:
• The higher noise level - cotton wool in t-he ears
may help.
• Turbulence - the light aircraft will be more
affected. Don't fight it, relax and go with the
motion.
• Pressure c hanges and the ears - most light aircraft
are unpressurised and climb quite slowly and the
ears automatically compensate. During fast descents,
holding the nose and blowing it with the mouth
closed will work, or follow the practice of some
airlines and have a few sweets handy.
• Mention the stall warning horn and other a ural
warnings. A sudden unexpected blast on landing will
not help passengers' nerves.
.
• Lookout - discuss the usefulness of a second pair of
eyes when joining the circuit.
• What to do if feeling unwell , but don ' t mention the
word sick. (Make sure there are sick bags on board.)
• The lack of a toilet , even in some larger twin -engine
aircraft.
use position D , with their chins resting on their chest ,
but if a n inertia reel system is fitted position C is
better. (Incidentally, much of this advice is equ ally
applicable to car passengers.)
Decide the order in which the aircraft should be
abandoned.
Harness and belts should be tight, and headsets
removed and stowed.
Brief passengers to unlock the cabin doors just before
landing or ditching, but not to unfasten doors before
impact.
Keep seat belts fastened until the aircraft has
stopped, undo belts, open doors and get out fast.
Make sure that passengers know how to operate the
front seat-back release (which releases rear-seat
passengers in some a ircraft) and door locks. If the pilot
is unconscious it is too late to ask.
Tell passengers to kick or force out a window if the
doors or canopy cannot be opened , or if the aircraft
has overturned.
A student pilot had been authorised to carry out a
period of solo circuits and landings. His last flight had
been 21 days earlier when he had completed a dual
check before going on his third solo. Conditions were
fine: CAVOK, the wind light and variable and a
temperature of + 15° C.
Four uneventful circuits were carried out in the
PA28. On the fifth circuit the pilot flew a normal
approach and landing. At about 4-0 knots on the rollout, as he was about to reintroduce engine power to
take off again, he applied pressure to the right rudder
to counter the anticipated swing. The Cherokee
immediately swung to the right in a rapidly increasing
skid.
Departing the runway about 127 metres beyond the
initial touchdown point, the aircraft skidded across a
grass surface for a further 90 metres before sliding
into a drainage ditch 2.5 metres deep and 6 metres
wide.
Comment
T he accident was attributable to incorrect operation
of th e rudder controls by the pilot at an early stage of
his training. This was a matter for him to sort out
with his instructor.
What emerged of general interest was the fact that
the pilot suffered minor facial lacerations during the
impact because he was not wearing the sash
component of the aircraft's lap-sasb seatbelt. Looking
at the accident photograph, it is clear that the injuries
sustained could easily have been worse. The reason
given for not using all of the belt was comfort,
although this is a little difficult to understand given
that the sash was connected to a serviceable inertia
reel. The pilot also stated that he had worn the full
belt only once, which is a poor reflection on that
aspect of his training.
Seatbelts are a proven life-saver; it is in every pilot's
interests a lways to use them properly •
Aviation Safety Digest 1 2 9 I 15
14 I Aviation Safety Digest 129
�Power towing
A Cessn a 40 1-A o n an ! FR charter fl ight arrived in the
circuit a t a country airport for la nding. Sarwatch was
cancelle d and pre landing checks carried o ut . H owever,
the pilot was una ble to obtain a nose gear 'd own and
locked ' in dication.
After checking the indicating system the pilo t
e lectrically cycled the undercarriage a bou t fo u r times,
without success. A m an ual extension was then
a ttempted , and it too was unsuccessful. The pilo t
retracted the undercarriage, advised the Flight Service
Unit of his problem, and passed de tails of his intention
to d ivert to a GAAP airport, where emergency services
and technical assistan ce were availa ble.
After a n uneventful flight the Cessna en tered the
GAAP Con trol Zone, where a n a ttempt was again mad e
to lower the nose gear. The indi cations wer e the same
as befo re, and during a fly-p ast for insp ection , a LAME
con fi r med that the nose gear was in an u nsafe position ,
being only p artially exten ded .
T he pilot t herefore d iscontin ued attem pts to lower
the nose gear and decided to m ake a landing on the
mainwheels only. In clear conditions and wi th a
head wind componen t of a bout 5- 10 kn ots, a smooth
tou chdown was m ad e . Initia ll y the nosewheel was held
off. At a low forward airspeed th e C401 settled on to
the nosewh eel , which collapsed rearwards and allowed
the nose of t he aircraft to impact with the landing
surface.
Technical investigation
A specialist examina tion of the nosewheel
undercarriage actuati ng system showed th at materia l
fa ilures h ad occurred in the fuselage nose sectio n
structure su p porting the retraction linkage.
T he nose gear section of t he a ircraft was
substan tia lly damaged during the emergen cy la nding.
However, detai led techn ical inspection showed tha t
fat igue cracking of the torque tube mou n ting bracket
assembly and suppor t bracket was present. C h afe marks
on a n adj acent angle bracket, caused by the movement
of th e ou tboard bellcran k , confirmed that the fa tigue
cracks in th e support brackets had been present before
the emergency la nd ing.
T h ese su pport brackets absorb the major torque
reaction loads in th e nose gear section, d u ring:
• undercarriage exten sion
• undercarriage retraction
• groun d h andling .
On th e available eviderice, it appeared that th e fatigue
cracking h ad been progressive, an d had probab ly
orig ina ted from a section of the torqu e tu be mounting
bracket adjacent to the end of a stiffe ner. In time , the
crack progressed vertically down wards th roug h most of
the material, a llowing the forward section of the
bracket to move under load.
T his caused the adjacent support bracket to flex,
resulting in a fat igue crack emana ting fro m t he a ngled
vertical section a nd progressing horizontally to t he
lig htening ho le .
As the structural integrity of t he section decayed , it
could be expected t hat the downlock and up lock
16 I Aviation Safety Digest 129
In brief
tensions would d ecrease. This in fact had been the
case: it was fou n d that these tensions had required
freq uent a djustment, wi th the m ost recent having been
m a de 20 hours before the accident. These adjustmen ts
had , however, been within specified tolera nces, and so
were not considered abnormal.
Eventually the mounting bracket supporting the out·
board bellcrank and its associated support bracket
fa iled com pletely, which resul ted in ' lost motion' a nd
in effectual cranking of the nose gear operating system .
Under these circum stances the nose gear could not be
locked d own ei ther by normal m ethods or emergency
h and cranking.
The pilot was therefore committed to an em ergency
land ing wit h the nose gear in an unsafe position. This
was du ly carried out in a competen t manner, resulting
in m inima l d am age.
Analysis
O n the ava ilab le evidence it was not possi ble to ident ify
a particu lar event which precipitated the onset of
fa tigue cracking. However, the assessment of
investigators was that, most prob ably, the cracking was
the result of stresses imposed on t he torque mounting
bracket over a p rolonged period.
Str esses on the nose gear components are imposed as
a matter of course by the normal extension and
retraction of the undercarriage. Additionally, stress can
be applied by:
• operations from rough surfaces; and
• power towing of the aircraft during maintenance
operations using a r igid towbar attached to the
nose gear.
Discussion
About 5 per cent of this aircraft's takeoffs and la ndings
were made on relatively rough surfaces, all of which
were considered by the operators to conform with
acceptable stan dards.
It was normal workshop practice to tow the C401
using a motor driven tug. A large , adjustable towbar
was used for this purpose . The towbar was not
equipped wit h any shock-absorb ing device or s hear
pms.
The service manual for the 40 1 includes the advice
tha t :
Shoulder harnesses will be installed as stand'cl.rd
equipment on all forward facing seats in all U .S.
personal and business General Aviation aircraft that
are manufactured after 1January1985. The nonregulatory agreement by the manufacturers is the
latest step in a joint effort by the General Aviation
Manufacturers' Association and the Aircraft Owners'
and Pilots' Association to encourage pilots and
passengers to use shoulder harnesses. The two
associations claim that serious injuries and fatalities
would be reduced 35 per cent if aircraft occupants
wore shoulder harnesses. General aviation aircraft are
required by reglilation to have shoulder harnesses, but
only for their front seats.
*
Fuselage nose section structure showing outboard bellcrank and
failed outboard support bearing bracket in situ.
*
*
A pilot under training took off in a Cessna 172 on a
solo navex. One of the turning points in the navex was
within 10 nm of the edge of his topographical map.
During the course of the exercise the pilot became
unsure of his position. In fact, he had overshot the
particular turning point, and had 'gone off the edge'
of his map. As he was not carrying the adjoining map,
he was unable to fix his position visually. However,
with the help of ATC, he was eventually repositioned
back on his map and was able to conclude the flight.
It was later noted that, in addition to not ensuring
that the pilot was carrying all relevant maps, the
supervising instructor had allowed his student to take
off with an incomplete flight plan - true airspeed,
wind velocity and lowest safe altitude were all missing.
*
*
*
*
Having lined his Auster up on runway 25, a British
pilot ran the engine at 1800 rpm in order to clear
some rough running which he attributed to having
taxied at a low power setting. When the throttle was
opened fully at the start of the takeoff run the engine
misfired once but then ran smoothly. After the tail
had lifted and the aircraft had become airborne the
engine misfired badly. The pilot landed back on the
runway at a point half-way along its total length.
Braking was impaired by brake fade, especially on the
right hand side. The aircraft ran into some concrete
blocks which were positioned at the sou th-western end
of the runway to prevent vehicular access. The pilot
and passengers escaped injury.
Subsequent examination of the engine revealed that
the number 4 exhaust valve was sticking in its valve
guide. None of the valve guides had been correctly
reamed out after their installation in the engine.
Power towing is not recommended . However , aircraft can
be power towed to move aircraft over soft or muddy
ground or in emergencies by attaching a rope harness to
the main landing gear. Do not power tow aircraft with
towing vehicle attached to nose gear or the tail skid . When
power towing station a crew member in the a ircraft to
apply brakes in case of emergency. Use extreme caution to
avoid jerky motions, as serious structural damage can
result.
It is p ossib le that shock loads transmitted through the
nose gear to th e actuating mechanism may have caused
fatigue in the torque tube mounting structure, or at
least accelerated the rate of crack propagation.
Comment
Following the accident to the Cessna 401 , the company
decided to modify its towbars to include s hock
a bsorption a nd steering limit shear pins •
*
*
*
*
*
A typical propeller on a piston engine idling at 900
rpm has the kinetic energy of a 5 lb brick travelling
at about 250 mph.
Rigid towbar used for power towing during maintenance operations.
Aviation Satety Digest 12 9 I 1 7
�Human factors and aircraft
instruments
10
Adapted from an article by Prof. E. Edwards in Aerospace, Journal
of the Royal Aeronautical Society.
- ••
(a) Vertical
10
35.5%
9
8
Instruments may rightly be called the 'brains' of the
aircraft, for it i's upon their indications that the pilot
depends for flight safety and the effident operation of his
plane. Instruments and instrument flying are a may'or
branch of aviation and all personnel are required to have
knowledge, in .varying degrees, of this important branch.
The time is past when a superfi'cial understanding of
simply the general purpose of the instruments was
suffi'cient. Today a thorough knowledge of instruments
and their use i's a necessity and a distinct step in
advancement for pilots, groundmen, m echan£cs, and in
fact all engaged in aviati'on.
(G. C . De Baud, Pilots and Mechanics A iTcraft Instrum ent Manual ,
Ronald Pres.s Co., New York, 1942)
The primary fun ction of aircraft instruments is the
transfer of operational information to the pilot. The
accuracy of pilot interpretatfon of an instrument display
is influenced by the quality of the presentation , and the
degree to which human factors interfere with an accurate
transfer of the information. In quiet moments on the
ground when time is available, pilots should take a long
slow look at the manner in which information is
presented on cockpit instruments. Which way does a
pointer move, what are the graduation units , what do
different colour markings mean, what lighting is
available to each dial, and what happens if power or the
excitation source fails? In a well-known and frequently
quoted experiment, an American investigator R .B.
Sleight invited people to note the readings on a number
of dials. Five different dial formats were used, viz.
vertical, horizontal, semi-circular, circular and openwindow, as illustrated in Figure 1. The scale length,
pointer width, gradua tion marks and numeral design
were the same in each case. The participants were shown
several examples of each dial with different readings,
each presentation being of only 120 milliseconds
duration. The pointer always appeared on a graduation
mark, so that interpolation was unnecessary and each
response was clearly either right or wrong. Errors were
totalled for each display in order to compare the relative
efficacy of the five formats. The results arc shown in
Figure 2.
Many people might fe'el confident they could predict
the outcome of the experiment in advance. The
application of 'common sense' however does not always
provide either the correct answers or sufficient d etail
whe re human performance is concerned , and there is
ample evidence to show that this is the case. Designing
instrumentation for pilots is an activity which demands
valid data both from a pplied research, operational
experience, and accident investigation. Instrument design
has undergone enormous change over the past 70 ye ars ,
due almost exclusively to a combination of systematic
experimental studies and a wealth of operational
experience. Basic deficiencies in a design may be masked
18 I Aviation Safety Digest 129
7
012345 1 6
6
-
(a) Vertic al
1
8
9
10
I, I , I, I , I . I. I. I , I, I, I
27 .5%
(b) Horizontal
5
4
3
2
0
0
2
3
4
I
I
I
I
of instruments matches the particular task. Nevertheless,
pilots should become familiar with the design features of
cockpit instruments as a counterbalance for those
occasions where pilot performance is impaired.
The pioneering work on instrument errors was carried
out by Fitts and Jones in the U.S .A. after the-Second
World War. One section of their work concerned the
psychological aspects of aircraft instrument displays, the
objective being to modify the design of aircraft
instruments to improve the efficiency of the system. From
the data they collected, errors made by pilots were
divided into nine categories as follows:
sl
6
7
8
9
I , I
I
I
I
10
I
I
(b) Horizontal
(e) Open-window
.I.
....L--1.....
0.5%
Fig. 2. The errors committed by the 60 people who took part in
the dial experiment.
(c) Semi-circ ular
(d) Circular
(e) Open-window
Fig. 1. The five dial shapes used in the expPriment by
R. B. Sleight.
and only become apparent later, for example in an
emergency , when individual differences in dealing with
an unusual situation produce varying pilot error rates in
instrument interpreta tion. It is impossible to present
information on an instrument in a way which will
entirely cope with the infinite variety of situations which
arise in aircraft operations. Factors such as reduced speed
of pilot performance, fatigue or low morale may interfere
with instrument interpre ta tion even though certain
instrument design features may reduce the proba bility of
errors over a broad band of a nticipated conditions.
Consequently, it is important that pilots are familiar with
the characteristics of the ir instruments, in orde r to
improve interpretative pe rform ance in a va riety of
circumstances.
A serviceable aircraft instrument steadfastly supplies
the pilot with information regardless of the pilot's skill,
knowledge , stress, fatigue and environmental pressures.
The almost infinite variety of circumstances in which an
instrument must provide information to different pilots
places limitations upon tl-!e capacity of an instrument
design to cope with every circumstance. For instance,
pilot performance is adversely affected by discomfort,
which may have a variety of environmental causes,
including:
1. Thermal environment: wide variations in
temperature, humidity, and air movement are
discomforting. so that clothing is a relevant
consideration.
2. Lighting: brightness, glare, reflections, colour and
colour changes may affect performance.
3. Noise: loud or intermittent noises may cause
discomfort and distraction, or even damage to
hearing; very high noise levels may be debilitating.
4. Other environmental hazards: radiations, low
atmospheric pressures, vibration, acceleration,
hypoxia.
In the dial-reading experiment, different people made
different forecasts about the outcome of the experiment
before the results were known, and many of these
forecasts were incorrect. In other words, there is no
'common sense' knowledge which permits armchair
solutions regarding possible human performance. The
importance of proper evaluation is highlighted by the
results for the vertical and open window dials which
attracted 35.5 per cent and 0.5 per cent of all errors
respectively, or a ratio of errors between them of 70: 1. It
might be concluded that the experiment provided a
strong indication of optimum design. However, this is not
really so, as the most appropriate instrument design
depends upon the particular application. In the
laboratory experiment, the best design was the open
window, but once a specific application is defined, a
quite different arrangement may have provided optimum
pilot interpretation. Today's aircraft manufacturers
should avail themselves of the latest developments in the
human factors aspects of visual displays so that the design
Type of error
Proportion oftotal(%)
1. Errors interpreting multi-revolution
instruments (the most common specific error
was misreading the altimeter by 1000 feet)
2. Reversal errors, where the interpretation of
an instrument indication was reversed, and
subsequently applied corrective measures
served to aggravate the condition
3. Signal interpretation errors, e.g.
misunderstanding the message conveyed by
warning horns or lights
4 . Legibility errors, usually due to the difficulty
of reading an instrument scale distinctly
enough to obtain a correct reading
5. Substitution errors: mistaking one instrument
for another, confusing which engine or system
an instrument refers to , or failing to locate an
instrument when needed
6. Using an inoperative instrument
7. Scale interpretation errors, due to difficulty
in interpolating between numbered
graduations on a scale, or failure to interpret
a numbered graduation correctly
8 . Errors due to illusions, e.g. misconceptions of
attitude because of differences between body
sensations and instrument indications, or due
to illusions which occur under instrument or
marginal conditions of weather
9. Forge~ting errors: failure to refer to or
properly check an instrument prior to takeoff
or during flight
18
17
14
14
13
9
6
5
4
100
Accident investigations show that these categories cover
all instrument interpretation errors made by pilots today.
Whenever a pilot makes an instrument interpretative
error, it will fall into one of these categories.
One finding made by Fitts and Jones was that the
difficulties they exposed in interpretation of aircraft
instruments posed a greater variety of problems for
researchers than did errors in using aircraft controls.
With the passage of time an enormous amount of
research has occurred in this area, which is of great
significance in advanced technology cockpits. The advent
of microprocessors, digital systems and cathode ray tube
displays on the flight deck are bringing about a dramatic
change in the pilot's working environment. Different
aircraft types, whether large or small , may attract
different and specific considerations regarding
instrument interpretation, but pilots generally should
consider carefully how the instrumentation of the
particular aircraft type(s) they operate may be prone to
the kinds of errors categorised above •
Aviation Safety Digest 129 I 19
�Low cloud base, rising terrain
Overs'tressed
Those pilots who have lost control of an a ircraft know
wha t an alarming experience it can be. Because of the
stress which the pilot will a lmost certainly experience
when control is lost, sometimes it is difficult to assess
how much of ano ther kind of stress - nam ely, tha t on
the a irframe - was applied during attempts to rega in
control. With the adrenalin pumping a nd the airs peed
possibl y increasing rapidly, the actua l aerodyn amic
load can often be well in excess of that which the pilot ,
thro ug h his 'feel' of the aircraft , believes he is applying.
As structura l damage often is eithe r not easily detected
o r in fact is all be low the surface, it is good airm a nship
to have your aircr aft thoroug hly inspected if you have
ha d to ' pull out' following a n in ad vertent loss of
co ntrol. Failure to do otherwise can place subsequent
users of the aircraft at risk.
A viation Safety Digest 122 contained an article entitl ed
'Freud , Jung a nd all that' in which the author
suggested tha t a co nnection exists between the
subconscious and the ' press-on must -get-through'
attitude which seems to be at the root of m a ny
weather-related accidents invol ving VFR pilots. The
article a rg ued tha t , when most of us plan a flig ht fro m
A to B , we p rogra m our subconscious to get to B . We
usu a lly have n o d oubt about getting to B . All o ur
thoug hts and expecta tions are of a positive nature; we
think o nly a bout getting there, and work ou t how to do
it. W e rarely pla n to get par t-way there a nd turn back.
This kind of mental state seems to have been a
significant factor in an a ccident in which a Grumma n
AA5A m a de a controlled entry into m ounta inous
jungle terrain .
Pressing on
Not lo ng after the Grumman took off, the pilot no ti ced
low cloud obscuring the tops of a mountain range
which h e intende d crossing. Approaching the range he
h ad to fly around some hills to stay under the cloud . A
little further o n he flew over a ridge where the ga p
be tween the treetops and the cloudbase was abou t 300
fee t. Having squeezed through th a t gap he found his
prog ress blocked by a hill, which necessita ted a left
turn - whereupo n he was confronted by another ridge.
Again, a n arrow ga p existed b etween the terrain a nd
the cloud b ase. With foll power applied the pilot
a ttem pted to 'outclimb' the ridge and escape from the
tra p intp which he had pla ced himself. However , he
had left it too late. T he performance simply was not
availa ble: the Grumma n flew into the jungle canopy in
a wings-level a ttitude a bout 200 feet below the top of
the ridge line.
Analysis
Not the least of the safety lessons to em erge from this
a ccident was th a t of the pilo t's low exp erience level. H e
h ad flown only 230 hours over a ten year period . For
m ost of us a combina tion of limited exp erien ce a nd a
slow rate of accumulation of tha t experience has
20 I Aviation Safety Digest 12 9
obvious consequences fo r the development of judgment ,
particularly in demanding c ircumstan ces.
Just as interesting was the pilot's refusal to accept the
obvious, i.e. the actual conditions. In discussions after
the accident the pilo t commented tha t it was apparent
when he was approaching the mo unt ains tha t the track
he wished to fly was going to be 'difficult' or 'unlikely' .
Yet he continued 'for a closer look', even thoug h all his
energies had to be directed towards rem a ining clear of
terra in and cloud , a nd othe r tasks such as navigation
had to be ig nored.
As is a lmost always the case wit h this sort of
accident, opportunities to turn back in time we re
ignored . Even as la te as th e fina l left turn towards the
ridge it seems likely tha t a turnback could have been
m ade. However , the pilot a llowed himself to be drawn
on by the 'gap ' a head.
T wo other fac tors are worth m entioning . First , in
deciding to make the fina l lef t turn , the p ilot
misjudged the distance and heig ht to the ridge line .
This kind of misjudgme nt is commo n in VFR/ IFR
a ccidents. The point to absorb here is tha t m a king a
correlation between the conditions a nd your aircraft's
performance capabilities can be difficult, pa rticula rly if
you are under stress and inexpe rien ced . Second, the
pilot did not know the pe rform an ce par am eters to
a chieve the best angle of climb fo r his pa r ticula r
a ircraft.
Summary
T he pilot subsequently m entione d tha t h e suffe red
from a m ental block during the la tter stages of the
flight; clearly, this would h ave impaired his decisionmaking capabilities. As Freud, Jung and company
observed so long ago, this potentially da ngerous
behavioural characteristi c - from which few , if any, of
us are immune- can be related to a ttitude. For
avia to rs th e key to ove rcoming the problem lies
prima rily in preflight planning , a nd infligh t
understa nding of one's equipment, environmen t an d
limi tations •
An IMC circuit
T he fi rst leg of what was to be a long , combined
business and pleasure trip wa s initi a lly cond u cted in
visu a l me teorological conditions. H owever , as the
Wa rrior approached the circuit a t the first planned
la nding point , low cloud began to close in . The pilot
joined the circuit at 500 feet agl , intending to land on
r unway 19, but, when he rolled out on fina l, he saw
that he was in a g ross overshoot and m ad e a goaround. H e then adjusted his flig ht p ath to join for
run way 11 , but midway down wi nd lost sig ht of the str ip
because of ra in a nd low cloud. A r igh t turn was carried
out towards the nearby township in an a ttempt to give
h im self time a nd space to sort things ou t; instead ,
however, the PA28 entered cloud.
Experien cing tempora ry confusion ove r interpreting
the info rm ation displayed on the fl ight instruments, the
pilot lost control of the a ircra ft. With two notches of
fla p selected , the a irspeed built up to about 120 kno ts
before control was regained. The pilo t la ter estim ated
tha t the force he applied was a bo ut the sam e as tha t
needed to hold a level, 60 degree banked turn , i.e. 2g.
After two minutes in cloud the Warrior e merged in the
clear, a bo ut 1000 feet lower tha n the heig ht a t which it
ha d entered: fortuna tely for those o n boa rd it had been
tracking towards lower terrain.
Becau se of the ra pidly deteriorating weather.
condi tions, the pilot decided to la nd a t a n agricultura l
strip a bout fi ve miles from the township ; this he
completed uneventfully.
Following this occurrence the trip was resum ed and
about 18 ho urs were flown before the PA28 re turned to
its hom e base. A further 8.5 ho urs were then flow n by
a n umber of o ther pilots. Despi te numero us d aily a nd
preflig ht inspectio ns, no d a m age was noticed by a ny of
the p ilots.
However , o n a subsequent p eriodi c inspectio n , both
wings were found to be bent upwards as a result of
a pplied aerod yna mic loads. The m a inten a nce report
stated tha t both the left and right wing upper inboa rd
skins a ft of the sp a r showed signs of extre me stress,
with the skin being cracked in several places.
Comment
Discussions with the pilots who flew the a ircraft after its
return indicated tha t none of them had placed unusua l
demands on the Piper. Thus, while a definite
conclusion could not be drawn , it seemed probable that
the damage ha d b een done following the loss of control
in cloud.
Two main safety lessons ca n be drawn from this
occurrence. First , the PA28 a irfra m e has a limiting
maximum positi ve load facto r in the utility category of
3. 8 . The pilot thoug ht he applied abo ut 2g; however,
as both wings we re b ent u pwa rds , they obviously h ad
been subjecte d to muc h more th a n th at. As a nyone
who has flown aerob atics, and t he refore m o nitored a
direct-reading g-meter in flig ht , ca n attest , when it's
'all happening', it is very easy to a pply fa r more g th a n
intended . Clearly, this is likely to be the case dur ing a
recovery from loss of con trol. Indeed , there a re
numerous recorded occurrences of inflig ht breakup of
GA aircraft bec ause of extreme aerodynamic loads
having been applie d during attempted recovery
manoeuvres. The point is tha t , following this sort
of occurre nce, there is good reason to have a
thorough inspectio n made of the aircraft by a suitably
endorsed LAME.
Second , any d a m age can be ha rd to de tect. A
number of pilots failed to see the surface indica tions of
airframe damage o n this W arrio r (see the photograph).
T his reinforces th e need to have a specia list inspect the
m a chine •
In brief
Delay in initiating a go-around (that is, making the
choice too late) is as prominent a cause of landing
accidents as is failure to perform the manoeuvre and,
according to U.S. National Transportation Safety
Board reports, is far more likely to result in serious
injuries and fata lities.
Aviation Safety Digest 129 I 21
�•
c..o~~:...i .,....~'Wolll~~4.lll....... •
The article entitled 'Fatigue on the midnight express'
(Aviation Safety Digest 125) reminded me of an
experience I had, and which I would li.ke to share with
your readers as warning against the possible effects of
fatigue in the cockpit, particularly at night.
The incident
During one of the periodic refuelling strikes which took
place a few years ago I was asked to fly a Piper Aztec
from Archerfield to Sydney and return. Due to the fact
that the flight would not terminate at Archerfield until
the early hours of the morning of my seventh day of
duty, a dispensation was obtained from the Department
to conduct this flight. My preceding tours of duty were
not particularly tiring, and if the flight had proceeded
as originally planned I doubt that I would have
experienced any undue fatigue.
However, as often happens in such cases, there were
delays in the arrival of my aircraft following a previous
trip to Sydney and return, so that we did not actually
depart until some hours after the original ETD. The
problem was then compounded by the fact that
refuelling was required at Coffs Harbour after the
normal hours of operation of the -refuelling service, and
quite a few other aircraft were also waiting their turn
to be refuelled at Coffs. It was therefore already very
late in the evening by the time I had obtained the
necessary fuel and departed Coffs for Sydney.
There was considerable wind and thunderstorm
activity over the route, so that by the time I arrived
over Mt McQuoid VOR it was close to midnight, and I
was feeling pretty tired with the effort of continuous
IfR flight in rough conditions.
From Mt McQuoid I was cleared via the Hawkes
intercept to the 16 ILS approach. The distance from Mt
McQuoid to Hawkes is only 21 nm, and takes only
about seven minutes in an Aztec. In that seven minutes
I had to review the approach plate, tune and identify
the aids, complete my approach checks, and continue
to fly the aircraft in the rough conditions existing.
Having carried out all these necessary items I then
sat back to relax for a minute or two until the intercept
at Hawkes was reached. I think that it must have been
at this point during that brief period of relaxation, that
I literally fell asleep with my eyes open!
I can distinctly recall seeing the localiser needle leave
full scale deflection and, incredible as it may seem, I
also remember just watching it as it traversed the
deflection scale to centre and then out to full scale on
the opposite side, and thinking 'Now isn't that
interesting!' Why I did not react to the indication I do
not know, as I clearly saw what was happening. A few
seconds later Sydney Approach advised, 'Radar has you
through the localiser and diverging'. Even then I did
not react! I merely picked up the microphone and
acknowledged their transmission. As I was replacing
the microphone in its clip, I suddenly woke up to what
I was doing - or rather, what I was NOT doing. If I
remember correctly I think that I then said, 'My
apologies - it's too late at night. Request a radar
vector back to the localiser'.
22 / Aviation Safety Digest 129
Asleep on the job
This was given and acted upon , and I then reintercepted the localiser withouLdifficulty.
Having reported established and then visual at about
2000 ft, I was instructed to call Sydney Tower, who
advised me to 'continue approach, expect late landing
clearance'. In front of me were the bright approach
lights and the lights of the city, and these seemed to
have a kind of hypnotic effect, because once again my
mind drifted off the job in hand. The next thing I
remember was flaring over the e nd of the runway and
the Tower controller's voice: ' I say again, cleared to
land'.
I simply do not remember flying the final approach
- I seem to have been flying completely automatically
with only the subconscious part of my mind operating!
While taxiing in at Sydney the SMC controller asked
me for my ETD for Archerfield. When I advised that I
was cancelling the return flight in order to have some
sleep first, his reply (in somewhat less than standard
R / T phraseology!) was that he thought tha't would be a
... good idea! The return flight later that day after a
few hours of sleep was uneventful.
Analysis
I am sure that it was only my subconscious reactions,
due to having a reasonable amount of flight
experience, which prevented a more serious situation
from developing. I certainly cannot claim any credit
for consct"ous flying technique!
In retrospect, there were several things which I could
have done to avoid this situation, and which I would
now do in similar circumstances.
First, there was the original fatigue associated with
previous tours of duty. Although under the original
flight plan this was not a signifiqnt factor, once it
became apparent that departure from Archerfield was
going to be considerably delayed I should have either
cancelled or postponed the flight until the next day .
Second, while in cruise from Coffs Harbour to Mt
McQuoid I could have turned up the cockpit lights to
full bright for, say, ten minutes , and carried out some
simple stretch and flex exercises. There would have
been ample time to regain good night vision after
turning the cockpit lights back down again.
Third, I could have attempted a conversation with
the passenger sitting alongside me, who was awake and
reading a book, instead of just idly monitoring
instruments while the aircraft flew on autopilot.
Although I was unaware of it at the time, the fact that
I just 'couldn't be bothered' to talk to him was actually
an indication of the fatigue I was suffering.
Finally, and probably most significantly from an
operational viewpoint, I should have anticipated the ILS
approach and reviewed the procedure well before Mt
McQuoid. This would have reduced the workload in
that short leg to Hawkes. I believe that the sudden
burst of concentrated cockpit activity followed by a
minute or two of idleness before the intercept of the
localiser would have tended to be the 'last straw' to an
already overtired mind .
(Continued on next page)
The herd strikes back
Photograph courtesy of Mr K. Atkinson of 'Wrotham Park', Cairns.
While cattle mustering in the Northern Territory the
pilot of a Hughes 269 helicopter suddenly found
himself confronted by a cow which refused to move in
the desired direction. The pilot dropped down to a
few feet agl whereupon the cow began walking slowly
towards the herd. It then stopped again and the pilot
edged closer. The cow spun around, reared on its
hind legs, and attacked the helicopter, catching one of
its horns in the skid area. The cow was too much for
the helicopter and pilot, and seemed to push the
helicopter over in its fury. The helicopter then pitched
forward, rolled to the right, and struck the ground
causing substantial damage. The tail rotor assembly,
major sections of the vertical stabilizer, sections of
drive shaft, tail boom and large sections of perspex
were scattered up to 9 metres from the main
wreckage. When Bureau investigators attempted to
find the offending cow to examine its horns, they
learned it had been shot and butchered for the
evening meal on the day of the accident.
Investigation revealed that the pilot had been
Conclusion
I have been 'tired' on other occasions during my flying
career, but this was the first and (as far as I am aware
the only) time that I have been acutely fatigued.
properly endorsed in cattle mustering, but was low on
experience. In addition the operator's check and
training organisation did not provide the pilot with
adequate support to shepherd him through his early
mustering work. The pilot was in proper control of
the helicopter, which responded to. his inputs of cyclic
to the left, collective up , and additional power. The
pilot later stated he had been unaware that the cow
would turn on him, otherwise the accident may not
have occurred. In the helicopter mustering industry it
is considered necessary to get down low in order to
control some animals, although it is also common for
them to turn against the helicopter.
Cattle being mustered by helicopter tend to become
'stirrey' and sometimes take a while to settle down
after forming into a herd. Some herds have become
used to helicopter mustering and their familiarity may
easily encourage them to turn against their oppressor.
In this accident the pilot was also motivated by a need
to muster every single animal in order to make a TB
eradication program successful •
The Aviation Safety Digest is to be congratulated on
the article on fatigue which prompted this letter that article should be mandatory reading for every
pilot. It can happen to you! •
Aviation Satety Digest 1 2 9 I 23
�
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1986
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�Contents
3 Editorial
4 Helicopter safety -
loss of directional control
Articles by the U.S. Flight Safety Foundation and the Australian
Department of Aviation on the subject variously referred to as
'unanticipated right yaw', 'loss of tail rotor effectiveness' or 'loss
of directional control' in helicopters.
1o Fuel selection
An incident involving a Cessna 31 OR raised a number of
interesting points regarding fuel selector checks which are
completed under pressure.
11 Private pilot flight skill retention
A summary of a study sponsored by the U.S. Federal Aviation
Administration into the degradation of pilot skills.
15 Refuelling check
(Reader contribution)
A Hiller UH12 helicopter was refuelled with Jet A 1 instead of
Avgas.
16 Strike one -
you' re out!
A few facts which aviators ought to know about birds.
18 What is to be done?
This article discusses the question of whether the propellers
should be feathered before an emergency landing in which the
undercarriage is suspect.
19 Birdstrikes - a scientific approach
A new laboratory in Canberra has enabled the Department of
Aviation to identify bird species from a few fragments of feather.
20 Excessive approach speed
22 Index of articles -
issues 1-128
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation
Regulations and is published by the Australian Government Publishing
Service. It is distributed free of charge to Australian licence holders
(except student pilots), registered aircraft owners and certain other
persons and organisations having an operational interest In Australian
civil aviation.
Unless otherwise noted, articles in the publication are based on
Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
The Publications Distribution Officer
Department of Aviation
P.O. Box 1839Q, Melbourne, Vic. 3001
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Inquiries and notifications of
change of address should be directed to:
Mail Order Sales
Australian Government Publ/sh/ng Service
G. P.O. Box 84, Canberra, A.C.T. 2 601
Subscriptions may also be lodged at AGPS Bookshops in the capital
cities.
Reader contributions and correspondence on articles should be
addressed to:
The Director
Bureau of Air Safety Investigation
P.O. Box 367
Canberra City, A.C.T. 2601
© Commonwealth of Australia 1985
ISSN 0045-1207
R84/ 403(3) Cat. No. 85 13 76 3
Printed by Finepress Offset Printing Pty Ltd.
35 Fitzpatrick Street, Revesby, NSW 2212
Covers
The covers continue the theme of over 30 years of Digests - the
Australian aviation industry at work.
Front. A Bell Jetranger is shown lifting a Robinson R22 from a
remote location following an accident attributed to dynamic rollover.
Photograph by Mr John De Ruyter of BASI, Brisbane.
Back. A Hiller 12C at Moorabbin in 1962. Photograph courtesy of
Mr Neil Follett.
2 I Aviation Safety Digest 1 2 B
l
Editorial
This is the last regular issue of the Aviation Safety Digest to be prepared by the Bureau of Air
Safety Investigation. The Safety Education Section of the Bureau will be transferred to the
Flight Standards Division of the Department of Aviation on 1 July 1986. The purpose of this,
change is to allow safety regulation and safety education functions of the Department to be
administered by the one unit, thereby achieving a higher degree of co-ordination.
The origins of the Digest lie in the incident reporting system which was developed during the
years following the Second World War, and w hich led to the regular issue of a report entitled
the Accident and Incident Summary. Due to the wide interest which this document attracted,
an expanded discussion of selected accidents and incidents was commenced with the
production of Aviation Safety Digest No. 1 in July 1953. During the subsequent thirty two
years the Digest underwent several gradual changes in response to requests from the
industry, or new requirements perceived from within the Department.
The Bureau itself had several ancestdrs, the first being the Accident Investigation and
Analysis Branch of the old Department of Civil Aviation, followed by the Division of Air Safety
Investigation. After some minor name changes it became the Air Safety Investigation Branch in
1964, and finally the Bureau of Air Safety Investigation was established in June 1982.
Production of the Digest was maintained as these changes occurred, and it became a
magazine which was much anticipated and well received by the industry. Overseas interest in
the Digest has also grown with the passage of time, and it is now widely distributed throughout
the world to safety authorities, airlines, air forces, universities, and various General Aviation
organisations and operators. In return this has opened lines of communication which have
often proved to be mutually beneficial, through exchange of information and reports concerning
aviation safety matters.
Although annual accident rates have been gradually reducing in Australia for some time , it
seems that the rate of improvement has slowed or even plateaued . At the same time the
proportion of accidents where pilot factors are assigned continues to be unacceptably high.
For instance, between January 1969 and May 1985 there were exactly 50 fatal accidents
where the pilot-in-command factor 'continued VFR flight into adverse weather conditions' was
assigned as a principal or contributory factor. In these accidents 1 59 passengers and crew
were killed, nine people seriously injured, and only two persons survived unscathed. The past
four decades have seen the introduction of regulations, orders and rules to control the aviation
industry with the objective of improving safety levels. It is now believed both here and
overseas, that civil aviation generally may have reached the limit of accident prevention through
regulation, and that the way forward is through improved safety education.
The Department of Aviation has every intention of continuing to monitor compliance with
existing regulations, to modify regulations where necessary, and to develop new ones
wherever appropriate. However the Bureau itself does not have any regulatory functions, as its
role is to investigate accidents and incidents as an independent instrumentality, making
recommendations where necessary to the regulatory divisions with a view to enhancing safety.
The Aviation Safety Digest was part of the Bureau's safety education unit. With the transfer of
this unit to Flight Standards it will be possible to achieve better co-ordination of regulatory and
safety education functions by having both under control of the one division. It is also important
that the Bureau should not be seen to have the dual role of investigator and educator. The
aviation industry is in a state of gradual but continuous change, and it is hoped that the new
arrangements will lead to further reductions in the number of accidents through improved
education of pilots and .other personnel engaged in the industry.
Paul Choquenot
Director
Bureau of Air Safety Investigation
Aviation Safety Digest 12 BI 3
�Helicopter safety directional control
Photograph by Mr C. Alviani
loss of
The subject referred to as 'unanticipated right
yaw', 'loss of tail rotor effectiveness' or 'loss of
directional control' in helicopters has been a
matter of considerable concern for some time,
and a number of articles on the topic have been
written.
This section of the Aviation Safety Digest
contains two such items: the first is reprinted by
courtesy of the Flight Safety Foundation and
contains recent information derived from
extensive flight and wind tunnel testing of the
OH-58 (the U.S. Army version of the Bell
Jetranger); the second was prepared by the
Department of Aviation. The Department's
article is the second of two notices previously
issued to helicopter pilots and operators
warning them of the phenomenon and advising
on avoidance and recommended recovery
procedures.
The two articles are considered
complementary.
FLIGHT SAFETY FOUNDATION
however, except that for 'continental' helicopters (with
rotors that turn clockwise when viewed from above)
azimuths are mirrored and the phenomenon becomes
unanticipated left yaw.
The information presented in this item is important to
pilots of all single rotor/anti-torque tail rotor
configuration helicopters.
The information which follows has been given wide
dissemination among helicopter operators overseas
because it describes a phenomenon of low-speed
helicopter flying that has only recently been fully
understood . Earlier misconceptions have undoubtedly
contributed to some fatal helicopter accidents.
T h e phenomenon is called variously, unanticipated
right yaw or loss of tail rotor effectiveness. The
renewed understanding has come from extensive flight
and wind tunnel tests of the OH-58, the U.S. Army
version of the Jetranger. These tests disproved several
earlier assumptions concerning the yaw phenomenon.
And although the tests relate to only the one helicopter
type, the American FAA has issued advice that the
phenomenon applies to all single roto~ helicopters with
an anti -torque tail rotor.
It would be as well at this point to emphasise that all
figures given below relate specifically to the OH-58.
They can be taken as a guide Tor other aircraft,
Definition of unanticipated right yaw
Unanticipated right yaw is the occurrence of an
uncommanded right yaw rate which does not subside of
its own accord and which, if not corrected, can result
in the loss of aircraft control.
4 / Aviation Safety Digest 128
Low speed flight characteristics
Four aircraft characteristics during low speed flight
have been identified through extensive flight and wind
tunnel tests as contributing factors in unanticipated
right yaw. For the yaw to occur, the relative wind must
fall within certain azimuths and speeds. The four
aircraft characteristics and their associated relative
wind velocities (figures for OH-58) are as follows:
• weathercock stability (120-240 degrees, 5- 17
knots)
.
• tail rotor vortex ring state (2 10-330 degrees, 7-1 7
knots at 270 degrees, changing to 14- 17 knots at
the arc limits)
• main rotor disc vortex interference (285- 315
degrees, 10 - 20 knots)
• loss of translational lift (ail azimuths)
The aircraft can be operated safely with the above
relative winds if proper attention is given to controlling
the aircraft. If the p ilot is inattentive for some reason ,
however, and an unanticipated right yaw rate is
initiated while in one of the above relative wind
regions , the yaw rate may increase unless suitable
corrective action is taken.
operated routinely in this region. If corrective action is
timely, this characteristic presents no significant
problem. But if a right yaw rate is allowed to build,
the helicopter can rotate into the wind azimuth region
in which weathercock stability will accelerate the right
turn rate.
Weathercock stability
Relative winds from the rear will attempt to
weathercock the nose of the aircraft into the relative
wind. This characteristic comes from the fuselage and
vertical fin. The helicopter will make an
uncommanded turn either to the right or left,
depending upon the exact wind direction, unless a
resisting pedal input is made . If a yaw rate has been
established in either direction, it will be accelerated in
the same direction when the relative winds enter the
120-240 degree sector, unless corrective pedal is
applied. The importance of timely corrective action by
the pilot to prevent high yaw rates from occurring
cannot be overstressed.
Main rotor disc vortex
Relative winds from a small sector of the front left
quadrant can cause the main rotor vortex to be
directed onto the tail rotor. The effect of this main
rotor disc vortex is to change the tail rotor angle of
attack. Initially, as the tail rotor comes into the area of
the main rotor disc vortex during a right turn , the
angle-of-attack of the tail rotor is increased. This
increase in angle-of-attack requires the pilot to add
right pedal (reduce thrust) to maintain the same rate of
turn .
As the main rotor vortex passes the tail rotor , the tail
rotor angle-of-attack is reduced. The reduction in
angle-of-attack causes a reduction in thrust, and a
right yaw acceleration begins. This acceleration can be
surprising, since the pilot was previously adding right
pedal to maintain the right turn rate. (Analysis of
flight test data has verified that the tail rotor in this
situation does not stall.)
Thus the helicopter will exhibit a tendency to make
a sudden, uncommanded right yaw which, if
uncorrected, will develop into a high right turn rate.
When operating in this region, the pilot must therefore
anticipate the need for sudden left pedal inputs.
Tail rotor vortex ring state
Relative winds from the left will cause development of
vortex ring state of the tail rotor. The vortex ring state
causes tail rotor thrust variations, which result in
irregular yaw r ates. Since these thrust variations are
irregular, the pilot must make corrective pedal inputs
as the changes. in yaw acceleration are recognised.
The r esulting high pedal workload in tail rotor
vortex ring state is well known, and helicopters are
Main rotor vortex from a Bell 4 ?G engaged in agricultural spraying
Aviation Safety Digest 12 BI 5
�360°
Figure 1. Weathercock stability
90
180
REGION WHERE WEATHERCOCK
STABILITY CAN INTRODUCE YAW RATES
Figure 2. Tail rotor vortex ring state
360'
Relative winds from within
the arc shown can cause
tail rotor vortex rmg slate
Relalive wind speeds of as
low as 7 knots from directly
abeam. highe r
from olher directio ns.
can cause this phenomeonon
REGION OF ROUGHNESS
OUE TO TAI L ROTOR
VORTEX RING STATE
CALCULATED DATA
180
Figure 3. Main rotor disc vortex interference
REGION OF DISC
VORTEX INTERFERENCE
1
300
285
360
Loss of translational lift
The loss of t ranslational lift results in increased power
demand an d additional anti- torque requirements. If
the loss of translational lift occurs when the aircraft is
experiencing a right turn ra te , the right t urn will be
accelerated as power is increased unless corrective
a ction is taken by the pilot. When operating at, or
ne ar , m axim um power , this increased power demand
could result in rotor rpm decay.
This characteristic is most significa nt when operating
at, or near, maximum power a nd is associated with
unanticipated right yaw for two reasons.
First, if the pilot's a ttention is diverted as a result of
an increasing right yaw rate, he may not recognise that
he is losing relative wind an d hence losing translational
lift.
Second, if the p ilot does n ot maintain airspeed while
making a right downwind turn , t he aircraft can
experience an increasing right yaw rate as the power
demand increases and the aircra ft develops a sink rate .
Thus , insufficient pilot attention to wind d irection
and velocity c an lead to an unexpected loss of
translational lift. The pilot must continually consider
aircraft heading , ground tr ack, and apparent ground
speed, all of which contribute to wind d rift and
airspeed sensations. Allowing the h elicopter to drift
over the ground with the wind results in a loss of
relative wind speed an d a corresponding decre ase in the
translational lift produced by the wind.
Any reduct ion in t ranslational lift will result in an
increase in power demand and anti-torque
requirements.
Recovery technique
The U .S. Army/ Bell tests showed that the aerodynamic
loss of tail rotor efficiency that indu ces the
una nt icipated rig h t yaw in some low-speed regimes is
n ot a tail rotor stall caused or aggravated by the
application of left pedal, as ha d been previously
thought. The tests a lso determin ed that:
• full left pe dal to counteract the yaw, and
• forward cyclic to increase speed
invariably stopped the unan ticipated right yaw .
Collective p itch redu ction will also aid in arresting
the yaw rate but may cause an excessive rat e of
descent. Any subsequen t large, rapid increase in
collective to prevent ground contact m ay then increase
the right yaw rate. T he decision to reduce collective
must therefore be based on the pilot's assessment of the
h eight ava ilable fo r recovery.
If the right yaw cannot be stopped a nd ground
contact is imminent then an autorotation may be t he
best cou rse of a ctio n .
Conclusion
Operating a single rotor helicop ter with relative wind
velocities from certain sectors requires a sou nd
kn owledge of the forces a nd phenomena involved and a
h igh level of con centration on controlling the aircraft ,
with p a rt icu la r atten tion to the correction of
u n an ticipated yaw in any direction, but more so if t he
yaw is to the right (or left for 'continental' helicopters).
*
6 I Aviation Safety Digest 1 2 B
*
*
DEPARTMENT OF AVIATION
In April 1983 the Department of Aviation distributed a
paper titled ' Loss of directional control in 'helicopters'
to Australian helicopter opera tors and p ilots. Since
then , the Department has continued to investigate the
problem of loss of dir ectional (yaw) control in
helicopters due to non- m echanical causes. As a result
of this ongoing investigation and in the light of
exte nsive resea rch and trials conducted by Bell
Helicopter Textron in the U .S.A., it is now n ecessary to
modify the advice of April 1983 in some respects. It
should be noted , however, that the Depa rtment is n ot
yet satisfied th a t the complete facts rela ting to this
phenomenon have been established , and further
information is being sought from overseas civil aviation
and military au thorities.
I n the m eantime, it is considered desirable in the
interests of flight safety to disseminate what is presently
known a bout this problem , to reiterate the need for
avoidance of conditions likely to lead to a loss of ya w
control, to stress pilot awareness of the problem and to
clarify recovery actions should control be lost.
While all of the known loss of yaw control accidents
and inciden ts in Australia h ave involved Bell 206
helicopters, sufficient evidence is availa ble to indicate
that this phenomenon is not unique to that type of
helicopter. Insufficient information is available to
deter m ine whether some types are more susceptible
than others. This paper should therefore be taken to
apply to all tail rotor-equipped helicopters including
those with main rotors rotating in a clockwise direction.
However, in the interests of clarity, only helicopters
with counter-clockwise rotating rotors are discussed.
Background
In recent years in Australia , five lives have been lost,
six injuries have occurred, and four helicopters have
been destroyed o r substantially damaged in acciden ts
attributed to or suspected of being caused b y loss of tail
rotor control. In addition, the Departmen t has received
info rm al advice of several other occurrences where yaw
control was lost b u t the pilot involved managed to
rega in control. It is unfortunate, of course, that these
incidents were not formally reported when the y
occurred and subjected to normal investigative action
- a clearer and more comprehensive picture of the
extent of this problem m ay have been id entified much
earlier.
I t is difficult to determine why this phenomenon h as
only relatively recently been recognised and given
publicity. The tail rotor exh ibits much the same
a erodynam ic characteristics as tue main rotor, and it is
not unreaso nable to suspect t h at a vortex ring state or
settling with power condition could also occur in the
tail rotor when an airflow equ al and opposite to the
induced flow is introduced. N evertheless, opinion
continues to be divided on the cause and effect of this
phenomenon. For example, when the Federal Aviation
Administration in the U.S.A. was recently asked
whether they had any knowledge of this problem they
stated, -in part: 'The suggested tail rotor stall condition
. .. has not been considered a cause factor to any
accidents or incidents . '. .' The U.S. Army on t he
A viation Saf ety Digest 1 2 BI 7
�the helicop ter to simultaneously encounter a strong
weather -cocking yaw to the r igh t and a vortex ring may
be generated wh en the airflow from the left of the ta il
rotor's plane of rotation equals th e induced flow .
Under certain circumstances, insufficient left pedal
may be available to con trol the combin ed effect of
th ese yawing moments and the helicopter will enter an
uncontrolled yaw to the right. T he onset of this yaw
can be quite rapid and h a s been likened , by those who
have experien ced it, to a complete loss of tail rotor
thrust as would occur if the drive sh aft h a d failed. In
some cases, the uncontrolled yaw has been
accompanied by a severe nose d own or nose up p itch.
The reason for this has not yet been determin ed.
High gross weight and / or density altitude m ay also
h ave a bearing on the likelihood of encou ntering this
phen omenon in that both require additional left pedal
when hovering . Neith er is consid ered t o be critical ,
however, and numerous inciden ts of loss of yaw control
h ave been recorded at q uite low weights and density
altitudes. Main rotor and hence tail rotor droop can
also affect the on set of loss of yaw control and the
subsequent recove ry by limiting the thrust availa ble
from the tail rotor.
Photograph courtesy of Mr Andrew Lang
other hand has been concerned since at least 1977
about what they term 'loss of tail rotor effectiveness' in
their OH-58 helicopters.
One explanation is that , in p art , helicopters are
being operated differently now than ten or twenty years
ago. In the military, emphasis is now on nap-of-e arth
flying, and in the civil environment, police, r escue,
ambulance and especially m edia helicopters are often
called upon to operate out of ground effect at low
airspeeds or in a hover. While modern helicopters are
much more capable of operating in this environment
due to better power-to-weight ratios , basic piloting
skills and techniques may have suffered as a result.
Be that as it may, there can be little doubt that loss
of yaw control is an incr easing rather than a
diminishing problem. In the short term, it is
improbable that manufacturers will be able to
overcome it by design changes or engineering
modifications. Like main rotor vortex ring, retre ating
· blade stall , ground re~onance, dynamic rollover etc.
loss of yaw control is just one more aerodynamic
problem that helicopter pilots must contend with. T he
answer , therefore, lies in pilot training and awareness
and in avoidance of situations where it is likely to
occur.
Conditions conducive to the onset of loss of yaw
control
The airflow around a t ail rotor c an be quite complex,
and is influenced by the movement of the tail rotor in
relation to the air m ass a round it (caused by control
inputs or ambient wind), m ain rotor trailing vortices
(similar t o wing tip vortices in a fixed -wing aircraft)
8 ! Aviation Safety Digest 128
and the airflow generated by the tail rotor itself by
virtue of its rota tion and aerodynamic properties . T he
flow through the tail rotor can , of course, be from
either side of the plane of rotation depending on
whether the rotor is under power or operating in a
windmill state.
In normal cruise flight, main rotor vortices do not
interfere with the air mass in the vicinity of the tail
rotor and main rotor torque is balanced by a
combination of fuselage / vertical stabiliser slipstreaming and thrust from the tail rotor. The direction
and velocity of the airflow into the tail rotor are
relatively constant under these conditions .
This situation changes markedly when the helicopter
is decelerated to airspeeds below approximately 30
knots , especially if a left crosswind is p resen t or is
created b y allowing the helicopter to yaw to t he right.
On this latter point, the absence of visual cues at
heights above approximately 200 feet makes the
maintenance of heading difficult , particularly if the
pilot's attention is diverted by other requirements
relating to the task he is attempting to per for m. An
inadvertent, unnoticed and hence uncorrected right
yaw can be a major factor in the onse t of loss of yaw
control.
As effective t ranslational lift is lost, increasing left
pedal must b e applied t o m aintain h eading . If this is
not done or if the h elicopter is deliberately yawed to
the right during this critical transition stage, the
trailing m ain rotor vortex m ay introduce t urbulent a ir
into t he t ail rotor and cause large and rapid ch anges to
the amount of th rust produced. Depending on t he
relative directio n of t he left crosswind, it is possible for
Recovery actions
Much conflicting advice has been p ublished over recent
years concerning recovery from loss of yaw con trol. Bell
206 operators will recall Bell H elicopter T extron
O peration s issued two Safety Notices da t ed 31 O ctober ,
1983, de tailing recovery a ction. The Department did
not ag ree with the p roposed action and recommended
an alternative autorotative recovery in a letter to
h elicopter opera tors dated 19 Decem ber 1983. T his
was d one on the basis of reports from pilots wl:10 had
successfully recovered the helicopter using that
procedure an d because the pilot had no way of
knowing whether the loss of tail rotor control had been
ca used b y a erodynamic effects or by a m echanical
failure or m alfunction.
Since that time , Bell H elicopter T extron (BHT) h as
conducted wind t unnel and flight trials which in dicate
th a t the recovery procedures contained in the BHT
Safety Notices of 31 October 1983, plus a BHT
Information Letter d ated 6 July 1984, are the most
ap propria te FO R BELL 206 T YPE H ELICOPTERS . The BHT
aerodyn amic an a lyses and recovery procedures have
also been endorsed by the Federal Aviation
Ad ministration in the U .S.A. In the absence of flig h t
test or other d a ta to refute or throw doubt on the BHT
findings, the Departmen t has no alternative oth er than
to endorse the recovery actions proposed in Bell's
references. Accordingly , the Dep artment's letter of 19
December 1983 h as b een ca ncelled and Be ll 206 pilots
should follow the BHT recover y procedures when there
is no d oubt that the loss of yaw control was caused by
aerod ynamic effe cts rather than by a mechan ical
m alfunction or failure .
As previously mentioned, overseas experience
indicates t hat loss of yaw control can and does occur in
other h elicopter types. Unfortunately, little is presently
known ab out the effectiveness or otherwise of th e
recove ry procedures used , and no firm
recommendations can be made at this time. It would
appear reasonable, however, to suggest that the
immediate application of full pedal opposite to the
direction of the yaw together with forward cyclic will
recover the h elicopter during t he incipient or early
stages of the uncommanded yaw. If this does not have
the desired effect , and if height permits, entry into
forward autorotational flight may be the best solution.
O nce control has been regained, normal powered flight
can, of course, be resumed.
Summary
An uncommanded yaw can occur when a helicopter is
operated below approximately 30 knots out of ground
effect wi th crosswinds opposing the induced flow
through the tail rotor . Unless timely corrective a ction i1
taken by the p ilot, control of the helicopter may
subseq uently be lost.
Pilots should therefore avoz'd sit u ations which involve
a combina tion of the following:
(a) flight below 30 knots , out of ground effect
*(b ) crosswin ds from the left, particularly left rear
crosswinds
(c) high density altitude/ high gross weight
(d) sudden loss of effective translation al lift
(e) main rotor droop
*(f) right yaw either inadvertent or p ilot induced
*The 'avoid ' situations listed above refer only to those
helicop ters with counter -clockwise rot ating rotors. For
helicopters with clockwise rotating rotors the 'avoid'
situa tions marked * are reversed, as follows :
(b) crosswinds from the r ight, p articularly right
rea r crosswinds
(f) left yaw eithe r inadvertent or pilot ind uced
Common sense and airm anship dictate that such a
combination should never be d eliberately flown when
within the helicopter's heigh t / velocity avoid curve.
If low speed fl igh t is necessary:
(a) ensure th e helicopter is d ecelerated smoothly
(b) maintain the helicopter's nose into the wind
( c) prevent rotor droop
(d) prevent any deviation in the yawing p la ne
*
*
*
References
Department of Aviation, Loss of Directional Control in
Helicopters, April 1983.
2. Bell Helicopter Textron Operations, Safety Notices OSN
206L-83 -7 and OSN 206 -83-10, 31 October 1983.
3. Department of Aviation , Letter Ml31/l / 363-l ,
19 December 1983.
4 . Bell Helicopter Textron Information Letter
206-84-41 / 206L-84-27 , 6 J uly 1984.
Helicopter operators and pilots who do not already have these
references can obtain them by writing to:
T he Director, Special Operations Section, Flight
Standards Division, Department of Aviation, P .O . Box
367 , Canberra City, A.C.T. 2601 (for references land
3).
Bell Helicopter Australia (A ttn: Librarian), P.O . B ox 18,
Brisbane Airport, Q ld 4007 (for references 2 and 4) •
l.
Aviation Safety Digest 12 81 9
�Private pilot flight skill retention
Photograph by Mr R. Sibley
One of the first emergency checks a pilot has to carry
out following a loss of engine power concerns the fuel
selector - is it ON, and is it selected to the desired
tank?
An incident involving a Cessna 310R raised a
number of interesting points regarding fuel selector
checks which are completed under pressure.
Power line patrol
The Cessna was engaged on a low-level power line
inspection, looking for a broken line. As the operation
was being conducted over fairly rugged terrain, the
pilot was devoting all his attention to flying ~he
aeroplane. A reduced power setting of 18" of MAP and
2300 RPM was being used, sometimes with 15 ° of flap,
to keep the IAS between 110- 120 knots.
In due course the broken section of the line was
located, but the spotter wanted to continue the
inspection to see whether thunderstorms from the
previous evening had caused any other damage.
Approaching a small hill, which necessitated a gentle
climbing turn, the pilot applied power to both engines.
While the right engine accelerated normally, the left
engine lost power.
Trouble checks, including the fuel selector, were
immediately performed, but failed to restore power.
The pilot suspected it was some kind of fuel problem,
even though the selector and quantity checks had not
revealed any apparent anomaly. Because of this
suspicion he did not feather the left propeller after the
emergency check. This in turn created performance
problems. It was a hot day, so, with the high density
altitude, the 310 did not want to climb. After some
minutes the pilot did, however, feather the left
propeller, and a slow but safe climb was established,
and a safe single-engine recovery made.
Company inspection
Company engineers removed the cowls and inspected
the e ngine; they could find nothing wrong. A senior
pilot then took the aircraft out and carried out power
checks, which also were satisfactory. However, the pilot
then carried out a number of trials, which eventually
pinpointed the problem.
The C310R has a fuel selector for each engine. For
the left engine, the sequence of selection on the
circular indicator, reading in a clockwise direction, is:
•
•
•
•
Left engine OFF
Left main
Left aux.
Right main
The pilot found that with 18" MAP and 2300 RPM,
moving the selector from 'Left main' (which had been
the setting at the time of the power loss) to 'Left aux.'
did not affect the engine's output. However, if the
selector was positioned towards the OFF segment, just
enough for the fuel flow indication to flicker, th e
situation changed.
Under those circumstances, when the left throttle was
opened, the engine failed. This clearly was a
10 /Aviatfon Safety Digest 128
consequence of insufficient fuel being available to
satisfy the increased demand.
Analysis
Further examination by the company showed that, for
this particular aircraft, the left fuel selector pointer
could move some radians without actually moving the
vertical shaft on which it was mounted , i.e. without
moving the fuel selector valve. Thus, it was possible for
the pointer to indicate 'Left main' when in fact it was
partially OFF. It was also found that the placard for the
selector was not glued properly and could move, which
further increased the possibility of an erroneous
indication occurring.
At this point some comment on the design of the
selector label is warranted. As shown in the
diagram, the 'Left main' position encompasses an
arc of about 60 degrees. However, t here is a precise
detent for the ON position, and it is essential for the
selector to b e in that detent. It seems highly likely that
it was not in the detent when the incident occurred.
Follow-up
Not satisfied with leaving his investigation at that, the
senior pilot concerned carried out two more 'tests'.
When the power failure happened, the pilot-incommand had Instrument Approach Charts on the
floor near the fuel selectors. It was determined that it
was feasible for those documents to move the fuel
selector if bumped against them.
On the emergency procedures aspects, the
opportunity was taken during an Instrument Rating
Renewal on another pilot several days later to observe
his emergency procedures. When a simulated engine
failure was given in flight, the pilot identified,
confirmed, and, during his trouble checks, pointed to
the left fuel selector and stated 'Fuel on'. He did not,
however, physically check that the selector was in the
detent. As it happened , the pilot undergoing the
Renewal had given the pilot who had the engine failure
his 310 endorsement. Game, set and match to the
senior pilot who had traced this incident through with
commendable thoroughness.
All compa ny pilots and engineers were made aware
of the circumstances, and a detailed report was
submitted to the Department of Aviation for the
benefit of C310 (and similar types) operators •
Some pilots believe that flying an aeroplane is like
riding a bike - once you have learnt, the skills are
never really forgotten and all that is needed is an
occasional refresher flight.
However, the evidence is that this is not the case. All
pilots get 'rusty' to some extent if their skills are not
exercised sufficiently. Early discussions between
Department of Aviation pilots and industry instructors
indicate that a degradation of skills is often apparent
during a Biennial Flight Review.
Those who undoubtedly suffer most from the
problem of infrequent flying are the recreational pilots,
who, in the great m ajority of cases, hold a Pr iva te Pilot
Licence.
The extent to which pilot skills degrade was the
subject of a study sponsored by the U .S. Federal
Aviation Administration (FAA) . Entitled 'Private pilot
flight skill retention', this study was initiated with the
objective of identifying the following items:
• The retention patterns for skills needed to
perform a representative range of private p ilot
flight tasks.
• The factors influencing the retention of these
skills and the nature and d egree of such
influences.
• The continuation training methods necessary to
maintain or improve skills.
A secondary objective was to assess pilots' ability to
predict and evaluate their own proficiency level.
While there are differences between U.S. and
Australian General Aviation - training, flying
conditions and so on - there are also many
similarities, to the extent that the findings of the FAA
study have considerable relevance in Australia , both for
the individual pilot in assessing his competence and the
flying supervisor who plans and monitors continuation
training.
With the kind permission of t he FAA , a summary of
the study is presented below.
A note for frequent flyers
Even though this study is concerned with PPL holders , it
is most important to note that all pilots are subject to
skill degradation, regardless of their licence category
and frequency of flying, if their technique or
continuation training cycle is deficient. For example,
evidence can be cited which shows that profession al
pilots lose skills in sequen ces, e.g. emergencies, which
are not practised often and regularly; while if
sequences are performed frequently, b u t in a sloppy
fashion, skill degrad ation will again occur .
The study - introduction
Flight skills will degrade over time if not exercised
sufficiently for the p ilot to be able to retain or improve
them. Thus, pilots who do not fly for extended periods
of time , or who fail to practise certain critical tasks
when they do fly, may be expected to make errors.
These errors can, in turn , contribute to a variety of
safety problems from which accidents and incidents
may be the end result.
The flying skill degradation problem can be
addressed through effective continuation training
programs. Such programs should be implemented on
the basis of a clear perception of the flight skills that
degrade over time and an understanding of the factors
that affect this degradation.
The p ilot proficiency data an alysed in the present
study were collected 8, 16 and 24 months after the
subjects received their certificates. All data could be
meaningfully compared since flight and written tests
used to collect the skill retention data were identical to
those used earlier in conjunction with private pilot
certification.
This study was conducted at the FAA Technical
Centre, Atlantic City Airport, New Jersey. Subjects
were personnel employed b y the FAA. Of the initial 42
subjects, 12 were available for the fin al 24-month
check. At the time of the final retention check, subjects
A viation Safety Digest 1281 11
�had a mean of 162 total flight hours (standard
deviation = 51 hours), and had flown a mean of 89
hours (standard deviation = 47 hours) since passing
their private pilot flight test. Some of the subjects had
undertaken additional training between their private
pilot flight test and the various retention checks,
whereas other subjects received no such training.
All flight proficiency data were acquired via the use
of an objective inflight data collection instrument
containing a standard sequence of flight tasks to be
administered in the aircraft. Error percentages on tasks
contained in the instrument served as the major
dependent measure of skill retention. In other words,
the percentage of errors made on the task was used as
the fundamental measure of how much of a pilot's skill
had been retained. However, four other types of data
were collected on each subject. They were:
1. survey data concerning flying activities since
certification
2. scores on an adaptation of the FAA Private Pilot
Written Test
3. precheck (prediction) questionnaire data
4. postcheck (evaluation) questionnaire data
The experimental design for this study evolved into one
in which comparisons were made of the skill retention
levels of the subjects who underwent additional
instrument training sessions during the 24-month
interval versus those subjects who did not.
A second performance comparison was derived from
an examination of when additional training was
received relative to the three retention checks. This
comparison was between two training subgroups, one of
which received most of its additional training before
the 8-month check (Group A) and the other of which
received most of its training after the 8-month c heck
(Group B). Thus, the skill retention of these two
subgroups and that of the no-training subgroup (Group
C) was compared across flight checks.
Subjects' flying activity data at the time of the 24-month
retention check
Total flight time (hours)
Recency (days since last flight)
Mean
Standard
deviation
162.3
157.0
51.7
98.I
B
70
FLIGHT EXPERIENCE SINCE PRIVATE PILOT CERTIFICATION
Flight time (hours)
Instrument training (hours)
Multi-engine training (hours)
Hood time (hours)
Dual time (hours)
Simulator time (hours)
Cross-country time (hours)
General Aviation aircraft passenger
time (hours)
General Aviation aircraft types
flown (number)
89.1
46.4
14.8
42.1
64.4
29.2
34.7
46.8
14.1
6.2
15.3
35.1
22.6
30.0
10.9
27.1
3.9
2.0
Group C , which received no additional training,
experienced virtually all of its skill Joss during the first
8 months. While Group A's decrement was relatively
less than that of Group B and C during the first 8
months, the decrement was statistically significant for
all three groups, a finding of definite operational
concern. In other words, the loss of flying skills since
certification was statistically significant for every group
- it could not be attributed to chance.
Skill decrement over the 24-month period was
statistically significant for combined flight tasks , as well
as for each task considered separately (except one
involving the use of a checklist) . Flight tasks exhibiting
the greatest and least decrement over the 2-year
retention interval were identified.
Scores on written examinations significantly
decreased over the initial 8-month period, but no
relationship was found between these scores and
inflight
error rates on the 8-month check.
Results and discussion
Subjects demonstrated a moderate ability to predict
Data were analysed for all three retention checks
and evaluate their own overall proficiency at the
relative to private pilot checkride performance. The
8-month
check. However, they were not accurate in the
majority of flying experience acquired by subjects
case of predictions/ evaluations of specific flight tasks.
during the 2-year interval occurred in conjunction with
Results of the present study strongly indicate that
their participation in other FAA-sponsored training
research projects. At the time of the 24-month check, a private pilots who do not operate aircraft frequently
mean of more than 5 months had elapsed since subjects need continuation training to maintain or improve
flight skills. To attempt to identify the specific types of
had flown, and most of the subjects' additional flying
experience had accrued during the 12 months following flying skills that degraded in the present study, a
preliminary analysis was conducted of performance
private pilot certification.
errors.
This analysis revealed that cognitive/ procedural
General decrement in performance was apparent for
all groups as represented by the decreases in percentage components were frequently performed in error on the
retention checks. For instance, all subjects failed to
of correctly performed measures over time. With
acknowledge at least one ATC instruction at some point
respect to combined ~oups, the decrement was
during
the 24-month check, and 70 per cent of the
curvilinear (i.e. skills degraded in a curved-line pattern
subjects used improper entry procedures for one or
and not uniformly with time) and approximated the
more of the stall manoeuvres.
classical 'forgetting curve' described in psychological
Both the general literature on skill retention and the
literature. However, the pattern of the decrement was
results
of the present study suggest that generation of
group-specific (i.e. degradation of skills was relatively
methods to improve the retention of cognitive skills
consistent within the three groups, but the specific
should be one of the primary objectives of continuation
pattern of skill decay was different for each group).
training. General aviation continuation training, as it
Group A's decrement was delayed by the effects of its
involvement in additional training occurring during the presently exists, does not sufficiently address the
initial 8-month retention interval. Group B experienced cognitive/procedural types of skills that are rather
rapidly lost during lapses in operations.
substantial decrement initially but relatively less
decrement during the second 8-month interval when
the majority of its additional training was received.
12 /Aviation Safety Digest 128
Mean flight times of the groups by 8-month retention intervals
60
A
Early Instrument-trained group
B
Late Instrument - trained group
c
No training group
A
Mean flight
t1mes(hours)
50
D
40
Instrument training hours
~
Multi-engine training hours
~
All other flight hours
30
20
B
10
0
0-8
8-16
16-24
Retention interval (months after certification)
Conclusions
Based on the results presented and the discussion and
implications thereof, a number of general conclusions
can be drawn:
1. Recently certificated private pilots who do not fly
regularly can be expected to undergo a relatively
rapid and significant decrement in their flight
skills. Further, such decrement will affect most
flight tasks that are required of the private pilot.
2. The effect of additional flight training is to
forestall (not prevent) skill decrement.
3. Instrument training, properly conducted, can
exert positive effects on the retention of both
contact and instrument flight tasks.
4. Greater and more pervasive performance
decrements may be expected for flight tasks that
require appreciable co-ordination between
cognitive and control skills.
5. Written test (i.e. knowledge) scores decrease
significantly during the 8-month period following
certification; however, written test scores are not
useful for predicting actual flight performance.
6. Private pilots who do not fly frequently need
periodic diagnostic assistance to help them
pinpoint specific flight tasks on which they need
continuation training.
7. Continuation training methods should be skillspecific and emphasise the development and
reinforcement of cognitive cues.
8. An urgent need exists for the development of
more effective performance criteria and of
continuation training methods designed to aid
private pilots in m eeting those criteria.
(continued overleaf}
Aviation Safety Digest 12 BI 13
�Mean per cent correctly performed measures by groups
across flight checks
Mean per cent correctly performed measures for each flight
task across flight checks
Tasks
Groups
90
(/)
A
B
c
~
:>
80
(/)
"'
E
Cl>
70
"U
Cl>
§
.g
Q;
a. 60
ti"'
~
50
c:Cl>
40
0CJ
~
Cl>
a.
c
"'
Cl>
::E
0
Private Pilot
8
check
24
16
Flight check
period in months
Editor's note
Further to this article, in mid-1985 the FAA issued a
proposal which included a number of changes in the
requirements for a Private Pilot's Licence. These
included the proposal that non-instrument-rated
private pilots with less than 400 hours of total flight
time would be subject to a new 2-hour annual training
requirement and annual review and recent flight
experience requirements •
Stop water contamination
Flight check (months)
8
16
24
84
54
51
88
74
100
64
48
76
37
79
80
51
52
67
67
94
60
50
66
39
71
76
38
57
89
94
95
90
94
93
93
88
83
84
74
70
68
75
67
80
89
81
54
52
56
51
52
55
56
54
65
53
58
53
52
62
40
56
51
56
51
61
75
63
41
41
38
33
97
90
100
94
100
66
79
90
68
93
70
63
85
65
87
66
52
78
54
74
100
95
79
72
83
99
98
79
90
92
95
98
74
68
74
62
77
77
76
Aircraft accident reports
LAST QUARTER 1985
The following information has been extracted from accident data files maintained by the Bureau of Air Safety
Investigation. The intent of publishing these reports is to make available information on Australian aircraft accidents
from which the reader can gain an awareness of the circumstances and conditions which led to the occurrence.
At the time of publication many of the accidents are still under investigation and the information contained
in those reports must be considered as prel iminary in nature and possibly subject to amendment when the
investigation is finalised.
Readers should note that the information is provided to promote aviation safety - in no case is it intended
to imply blame or liability.
Note 1: All dates and times are local
Note 2: Injury classification abbreviations
C = Crew
P = Passengers
0 = Others
N = Nil
F = Fatal
S = Serious
M = Minor
e.g. C1S, P2M means 1 crew member received serious injury and 2 passengers received minor
injuries.
PRELIMINARY REPORTS (The following accidents are still under investigation .)
(corrigendum)
Page 12 of Aviation Safety Digest 126 carried an
article on the outside storage of fuel drums and
requires correction. Somewhere between artwork
preparation and printing the drum lying down was
'rolled' 90 degrees, so that the bungs in the diagram
were shown as being in the 6 o'clock position instead
of the 3.45 position. The correct position ensures
both bungs are covered so that a leaking bung will
show, and also minimise 'weathering' of fuel should a
drum breathe due ·to expansion and contraction. If a
drum constantly breathes and a bung is not covered
with fuel, the light fractions in the fuel will gradually
be lost to atmosphere and the fuel will b e off
specification. The tilted drum was intended to
indicate the recommended position for pumping and
water testing. The low side of the drum is tested for
water, while the foot of the pump should be on the
high side.
The policy of some oil companies is that refuelling
aircraft directly from drums is an exceptional
14 I A viatfon Safety Digest 128
1. Engine runup before takeoff
check
2. Takeoff and departure
3. VOR tracking
4. Straight and level
5. Minimum controllable airspeed
6. Takeoff and departure stall
7. Approach stall
8. Steep turns
9. Accelerated stall
10. Engine failure during flight
11. Forced landing
12. Traffic pattern
(uncontrolled field)
13. Landing (uncontrolled field)
14. Short field takeoff
15. Short field landing
16. Soft field takeoff
17. Crosswind takeoff
18. Crosswind landing
19. S-turns across a road
20. Turns about a point
21. Rate climb (hood)
22. Magnetic compass turn (hood)
23. Unusual attitude
recovery (hood)
24. 180° turns (hood)
25. Go-around
26. Landing (controlled field)
27. Communications
Initial
licence
check
situation, and the drummed fuel should first be
pumped into a tanker or other approved arrangement
with proper filters and d rains. Any leaking drum, one
which has had the seal tampered with, or one which
h as an illegible exp iry date is downgraded to mogas
or otherwise disposed. The oil companies have no
policy regarding partly used drums , so that an
opened drum should be used immediately •
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure/Destination
03 Oct
1125
Robinson R22-Alpha VH-UXR
Wanaaring 83WSW
Non commercial - aerial application/survey
" Reola" Stn NSW/" Reola" Stn NSW
05 Oct
1200
Jodel 09-A VH-SJZ
Gatton QLD
Non commercial - pleasure
Gatton OLD/Gatton OLD
09 Oct
1415
Hiller UH12-E VH-AGL
Cape Portland TAS
Aerial mustering
Cape Portland Tas/Rushy Lagoon H'stead
09 Oct
1000
Cessna 182 P VH-I RL
Lawn Hill Stn OLD
Non commercial - pleasure
Tennant Creek NT/Lawn Hill Sin QLD
Injuries
Record number
C1N
8521054
The pilot intended to land the helicopter near a water tank so that he could free sheep bogged in the muddy ground. When the aircraft
was at about 80 feet agl on descent, the pilot applied power and raised the collective to reduce the rate of descent. He heard a bang,
followed by a noise he described as clutch growl and the helicopter began to vibrate severely. The collective was lowered momentarily
and power was re-applied, however, the clutch growl and vibration continued. The pilot lowered the collective but the helicopter struck
the ground firmly at a low forward speed and the main rotor severed the tail boom.
C1N
8511046
After completing a circuit, the aircraft was flown along the strip at an altitude of 50 feet. An airspeed of 50 knots was maintained with a
low power setting. Towards the end of the strip the pilot attempted to apply climb power but the engine did not respond. The pilot selected
a clear area straight ahead and landed the aircraft. During the landing roll the aircraft struck a tree stump which was hidden in the tall grass.
C1N , P1N
8531020
The pilot reported that while he was hovering the helicopter at about 25 feet agl, the engine suddenly lost power. He placed the helicopter
in an autorotation but maintained the throttle setting that had been set while the aircraft was hovering. Just as the skids were about to
contact the bushes, the engine momentarily regained power. The helicopter impacted the ground on its right hand side and fire broke out.
Both the occupants escaped from the helicopter before it was destroyed by fire.
C1N , P1N
8511048
The pilot stated that the aircraft was caught in a downdraught j ust prior to touchdown. The aircraft landed heavily and bounced . After a
second bounce the pilot carried out a go around. Following the subsequent landing, the damage to the propeller, fuselage and engine
fi rewall was discovered.
Aviation Safety Digest 128 I i
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure/Destination
Injuries
Record number
C1N
Non commercial - pleasure
Cessna 150 G VH-KPP
09 Oct
8551027
Nookawarra HS WA/Nookawarra HS WA
Nookawarra HS WA
1030
After the aircraft had been airborne about 90 minutes, the engine began to run roughly. The pilot's attempts to restore full power were
unsuccessful and the engine stopped. During the latter stages of the subsequent landing roll, the aircraft struck a dead tree and damage
was caused to the left wing and lower engine cowl.
C1N
Test
Quickie 0200 VH-FMV
10 Oct
8521057
Bankstown NSW/Bankstown NSW
Bankstown NSW
1230
The aircraft was being flown for the first time. The pilot stated that after takeoff the aircraft felt very nose heavy and that he had difficulty
in maintai ning a nose-up attitude after liftoff. When he attempted to reset the elevator trim the friction nut broke. The back pressure that
he was required to hold with the control column reduced as the airspeed increased. Du ri ng the subseq uent approach the pilot found he
had insufficient elevator control available to flare the aircraft. On touchdown the aircraft bounced and a go around was carried out. T he
pilot made several other landing attempts but on each occasion the aircraft bounced . On the final attempt the aircraft bounced a number
of times before the right canard collapsed and the aircraft ran off the runway.
10 Oct
0059
Israel 1124 VH-IWJ
Maroubra NSW 3E
Charter - cargo operations
Sydney NSW/Brisbane OLD
C2F
8521056
The aircraft was planned to conduct a regular freight service to Brisbane and Cairns. After an evidently normal takeoff from Run.way 16
the crew contacted Departures Radar, advised that the aircraft was climbing to Flight Level 370 and requested the direct track to Brisbane.
Approximately two minutes later the crew did not respond to calls from the radar controller, and the aircraft faded from the radar screen .
Witnesses subseq uently reported that the aircraft was seen diving steeply towards the water.
To date some of the wreckage has been recovered and attempts are being made to locate and recover the remai nder, together with the
flight data and cockpit voice record ers. Water depth in the area is about 85 metres.
12 Oct
1410
Hughes 269 C VH-SBR
Kununurra 97NNE
Aerial mapping/photography/survey
Kununurra WA/Kununurra WA
C1M, P1M
8551028
The pilot was requested, by the passenger, to land the helicopter on the mud flats to the north of Kununurra. He decided to make a run
on landing as he believed he may have difficulty in hovering the helicopter. As the ai rcraft approached the touchdown point, the pilot ~!lowed
it to yaw into wind, but it contacted the ground still moving sideways. The left skid caught in the dry mud and the helicopter rolled onto its side.
C1N
Non commercial - business
Hughes 269 C VH-WPP
14 Oct
8511047
Leigh Holme OLD/Epping Forest OLD
Clermont OLD 5W
0615
About five minutes after takeoff, the pilot heard a change in engine note and felt a slight yaw to the left. This occurred several times in
quick succession. The pilot reduced power and commenced a descent towards a disused mining area. At about 200 feet agl, the engine
failed and an autorotational descent was set up. As the pilot was attempting to manoeuvre the helicopter into wind and clear of some mullock
heaps, the tail rotor struck the ground. The main rotor then severed the tail boom and the helicopter came to rest 10 metres from the initial
point of impact.
C1N, P1M
Robinson R22-Alpha VH-HBO Non com mercial - pleasure
14 Oct
8541018
Warooka SA 5S
Warooka SA/Warooka SA 5S
1000
The p ilot positioned the helicopter on the downwind leg of the circuit at an altitude of about 300 feet agl. The wind was gusting between
30 and 35 knots. Towards the end of the d ownwi nd leg the pilot noticed that the helicopter was yawing to the right and that a high rate
of descent had developed. The pilot applied full power and lowered the collective slightly. The helicopter continued to descend and the
pilot applied full up collective, but the helicopter struck the ground heavily and bounced. On the second touchdown, the tail rotor struck
the ground and broke off.
C1S, P2S
Charter - passenger operations
Bell 206 B VH-PHB
15 Oct
8521058
Nowra NSW 26N/Albion Park NSW
Nowra NSW 26N
1515
The hel icopter had been chartered because the passenger's farm had been isolated by flood waters. The crew carried out a survey of
the area before landing to c heck the suitability of the chosen site. Shortly after takeoff, the aircraft collided with a power line which was
about 25 feet agl, and then struck the ground heavily about 15 metres beyond the line.
C1N
Non commercial - pleasure
Schemp STD Cirrus VH-GYZ
19 Oct
8531021
Horsham VIC/Horsham VIC
Horsham VIC
1430
During the launch by a tug aircraft for the pilot's fi rst flight of the day, turbulence was encountered at about 40 feet agl. The pilot released
from the tow and attempted to land straight ahead, however the right wi ng struck a post of the aerodrome boundary fence and the aircraft
grou nd looped before coming to rest.
22 Oct
0709
Piper 32 300 VH-PPF
Peterborough SA
Non com mercial - business
White Well SA/Mildura VIC
C1 F, P4F
8541019
Prior to departure, the pilot obtained a weather forecast for the route to be flown. He then submitted flight details that indicated the flight
would be conducted in accordance with visual flight rules. The aircraft was later observed to takeoff and head towards the north-east. At
the time of departure, it was reported that rain was falling and that low cloud covered the area .
Approximately 40 minutes after the aircraft departed, the wreckage was sighted by a passing motorist. Ground marks indicated that the
aircraft had struck the ground while head ing in a north-westerly direction.
C1 N
Ferry
Hughes 269-C VH-MSL
26 Oct
8551029
Mardie Stn WA/Mundabullangana HS
Karra1na WA 61SE
1705
As the helicopter was cruising at 1000 feet agl , the engi ne suffered a complete loss of power. An autorotation was commenced and the
pilot headed the aircraft towards a clear area, to land. At the completion of the landing flare, the heel of the skids dug into the ground
and the main rotor blades struck the tail boom.
ii I Aviation Safety Digest 128
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure/Destinatjon
Injuries
Record number
31 Oct
1245
Cessna A188B·A1 VH-UAY
Naracoorte SA 46NW
Aerial agricu lture
Naracoorte SA46 NW/Naracoorte SA 46NW
C1N
8541021
The pilot was engaged in spraying an area of grape vines. On the final spray path the aircraft had to pass under a set of power lines.
The pilot reported that as the aircraft approached the power lines, it was affected by an updraught. He pushed the control column forward
but the propeller and fin mounted wire deflector struck the power lines. The aircraft descended and struck a post used to support the vines
before it came to rest in the crop.
01 Nov
1657
Maule M7-235 VH-MBL
Bankstown NSW
Non commercial - pleasure
The Oaks NSW/Bankstown NSW
C1N, P1N
8521059
The pilot was making a landing ap proach in moderate crosswind conditions. Touch-down was made in a three-point attitude at an airspeed
of about 40 knots. Immediately afterwards, the p ilot experienced difficulty in preventing the into-wi nd wing from rising. He elected to go
around and applied full throttle, but was unable to maintain directional control. The propeller struck the ground and the aircraft cartwheeled
before coming to rest.
01 Nov
1730
Cessna 172 N VH-BWN
Pinjarra WA 5E
Non commercial - pleasure
Geraldton WNPinjarra WA
C1N, P3N
8551030
Prior to attempting the landing the pilot carried out an aerial inspection of the strip. The aircraft touched down on a gravel road leading
to the strip, which the pilot believed formed part of the strip. The ground track of the aircraft was affected by a wind-row along the side
of the road and the pilot was unable to control the ai rcraft. The pilot applied power to carry out a go around , however, the right main wheel
struck a car tyre which was used to mark the strip, causing the aircraft to veer to the left towards a fence. The pi lot managed to manoeuvre
the aircraft over the fence but it struck the ground, wingtip first, in an adjacent paddock.
02 Nov
1413
Cessna 172RG VH-KPL
Compton Downs OLD
Non commercial - pleasure
Compton Downs OLD/Richmond Downs OLD
C1N
8511050
The pilot reported that at about 50 knots during the takeoff run, he heard a loud noise and the aircraft began to progressively adopt a
nose-low attitude. The nose of the aircraft dug into the ground and the aircraft overturned . When the pilot inspected the aircraft following
the accident , he found that the landing gear was retracted and that the gear selector was in the up position . The p ilot did not recall the
position of the selector before the commencement of the takeoff.
07 Nov
0900
Cessna 152 VH-WFQ
Wollongong NSW
Instructional - solo (supervised)
Wollongong NSW/Wollongong NSW
C1N
8521060
The student was conducting a series of circuits with touch-and-go landings. Wind conditions were calm and during the fifth circuit the
pilot decided to carry out a full-stop landing before using another runway. At a speed of about 30 knots during the landing roll the pilot
applied braking , but the aircraft immediately veered sharply to lhe right and ran off the side of the runway. The nosegear was broken when
the aircraft entered a ditch before coming to a halt.
08 Nov
1150
Piper 28 R180 VH-CH I
Cessnock NSW
Instructional - solo (supervised)
Cessnock NSW/Cessnock NSW
C1N
8521061
. The p ilot had successfully carried out a series of seven ci rcuits with touch-and-go landings. He subsequently advised that he had been
experiencing difficu lties in maintaining accurate height and tracking on the downwind leg, and while concentrating on these points on
the eighth circuit he forgot to lower the landing gear. As he flared the aircraft, he heard a radio message instructing him to go around.
Full power was immediately applied , but the aircraft contacted the runway and skidded to a halt.
09 Nov
1208
Victa 115 VH-FHP
Cairndale SA
Non commercial - pleasure
Aldinga SA/Aldinga SA
C1F, P1F
8541022
The pilot had arranged to take each of his guests on a scenic flight of the local area. On the second of these flights, the aircraft was observed
flying at a low altitude and subsequently struck the top wire of a three-strand power line. The aircraft then cl im bed over a row of trees
before descending steeply into the ground. A fi re b roke out and consumed the fuselage of the aircraft.
10 Nov
1704
Hughes 369 HS VH-FAM
Baxter VIC
Non commercial - pleasure
Moorabbin VIC/Moorabbin VIC
C1F, P1F
8531022
The pilot and passenger were en route to Hastings to make an aerial inspection of a boat which the two men were considering buying .
The aircraft was in c ruising flight at a height estimated to be between 200 and 500 feet above ground level. A number of witnesses reported
that the engine made a spluttering noise, followed by a bang. Pieces were then observed falling from the aircraft , and some witnesses
saw the tail rotor assembly detach. The helicopter then dived to the ground and was destroyed by the impact and a fierce fire w hich broke
out immedicately afterwards.
10 Nov
1950
Westland Scout VH-NVY
Schofieli;Js NSW
Ferry
Schofields NSW/HMAS Nirimba NSW
C1N
8521062
The helicopter had been transported by road to Schofields to form part of the static display associated with an airshow. Although it was
airworthy, the helicopter was the only one of its type in the country and had not been approved for flight at the show. At the conclusion
of the show, one of the persons responsible for the restoration of the ai"rcraft became concerned for its security, and he elected to hover
taxi the helicopter a short distance onto Naval property. Control of the aircraft was lost shortly after it became airborne, and it struck the
ground whi le moving backwards before coming to rest on its side some 60 metres from the parked position.
12 Nov
1616
Cessna 177 VH-DZD
Morven OLD 9N
Non commercial - pleasure
Mitchell OLD/Charleville OLD
C1N
8511054
The pilot reported that while the aircraft was established in cruise, the engine rpm suddenly increased and the windscreen covered with
oil. The engine oil pressure gauge was indicating zero. During the subsequent landing, the aircraft ran off the sealed roadway.
Aviation Safety Digest 128 I iii
�Date
Tim e
Aircraft type & registration
Location
Kind of flying
Departure/Destination
Injuries
Record number
C1N, P5N
Supplementary airline
13 Nov
Sweargen 226 T (B) VH-SWK
85410 23
Olympic Dam SA/Goober Pedy SA
Goober Pedy SA
1115
The pilot reported that as the aircraft approached the flare height, it yawed violently to the right. The right maingear and nosewheel struck
the ground heavily and the aircraft turned to the right before the pilot was able to regain control. An inspection of the ai rcraft revealed
that the four blp.des of the right propeller had been bent and the lower fuselage skin was buckled.
05 Dec
0830
Beech C23 VH-I HP
Cai rns OLD
Instructional - solo (supervised)
Cairns OLD/Cairns OLD
C1N
8511055
C1N, P1N
Aerial mustering
13 Nov
Robinson R22 VH-UXE
8551031
Croydon Yard WA/Croydon Yard WA
Pt Hedland 84SW
1555
The pilot was mustering a herd of cattle across a tree-lined dry creek bed , when the mob scattered. He positioned the helicopter at tree-top
height to block the escape of the cattle from the creek. The rotor rpm rapidly decayed and the pilot was unable to prevent the aircraft
sinking and landing heavily on the bank of the creek.
09 Dec
0930
Date
Time
Aircraft type & registra tion
Location
Kind of flying
Departure/Destination
Injuries
Record number
C1S
Aerial agriculture
16 Nov
Piper 25 235 VH-SPB
8531023
Donald VIC/Donald VIC
St Arnaud VIC 24N
1146
At the end of each spray run, the aircraft was flown under a power line before the turn to change direction was commenced . Several runs
had been completed when the pilot climbed the aircraft to commence the turn and the aircraft collided with the power line. The pi lot dumped
the remainder of the load and the aircraft continued to fly, trailing the power line. After travell ing a short distance the aircraft apparently
stalled and struck the ground in a nosedown attitude. A fire broke out and completely engulfed the wreckage.
C1N, P3N
Beech B24 R VH-DJD
Non commercial - business
21 Nov
8511 051
Morana Station OLD/Emerald OLD
1510
Emerald OLD 37N
After having inspected a property, the pilot and his passengers returned to the aircraft to prepare for departure. A storm was approaching
the strip from the north and a 10-15 knot crosswind prevailed at the strip. A takeoff into the east was com menced and as the aircraft crossed
the upwind end of the strip it was affected by a sudden gust of wind . The aircraft yawed to the right, lost altitude and struck the ground,
before com ing to rest in a ploughed paddock .
·
C1N , P1N
Non commercial - pleasure
22 Nov
De Hav 82 VH-MDV
8521065
Camden NSW/Camden NSW
Camden NSW
0740
The aircraft had been refurbished during the preceding months, and at the completion of this work the pilot intended to carry out a short
test flight. He subsequently reported that as soon as the aircraft became airborne after a normal takeoff roll, it veered sharply and the
right wing droppedl Corrective control inputs had no effect, the wing and propeller struck the ground and the aircraft overturned , com ing
to rest about 200 metres from the start of the takeoff roll.
C1N , P3N
Non commercial - business
Cessna 172 N VH-UWD
22 Nov
8511052
Ouilpie OLD 32SSW/Ouilpie OLD
Ouilpie OLD 32SSW
1030
At about 200 feet agl after takeoff, the engine began to vibrate and lose power. The pi lot turned the aircraft to the right to position over
more suitable terrain. The airc raft was stalled into small trees and bushes before touch ing down heavily on the nosewheel, which broke
off. The ai rcraft then overturned and came to rest inverted.
C1N , P3N , 02S
Charter - passenger operations
Cessna 402-C VH-UEZ
23 Nov
8541024
Pulparee SA/Brisbane OLD
Pulparee SA
1345
T he flight had been arranged to take passengers and freight from Pulparee, a seismic exploration field camp, to Brisbane. Just after the
aircraft became airborne the right wing struck two men who were working on the top of the cabin of a truck. A section of the right wing
was torn from the aircraft, however, the pilot was able to land the aircraft at Pulparee without further incident. The truck was located approximately
24 metres to the right of the centreline of the strip.
C1N
Non commercial - aerial mustering
Piper 18 150 VH-CPI
02 Dec
8551032
Boolard y HS WA/Boolardy HS WA
Meekatharra 150W
0820
The pilot was engaged in sheep mustering. The aircraft was being flown at 200 feet agl, and about three minutes after the fuel tank selection
was changed, the engine lost power. The pilot selected the other fuel tank but the engi ne did not respond. The aircraft touched down heavily
on unsuitable terrain and the main gear collapsed.
C1N
Charter - passenger operations
Beec h 58 VH-SWT
03 Dec
8521068
Collarenabri 22NE/Pt Macquarie NSW
Collarenabri 22NE
1530
As the aircraft was being rotated for takeoff, the pilot detected a slight loss of performance from the right engine. He looked towards the
engine and saw evidence of fire around the air intake on top of the cowling. The takeoff was abandoned, both propellers were feathered
and heavy braking was applied. The aircraft overran the strip and entered a very muddy field. The nosegear collapsed and the right engine
was torn from its mounts before the aircraft came to rest 110 metres beyond the strip th reshold. The pilot rapidly vacated the aircraft and
waited for several minutes until rescuers arrived and extinguished the fire.
C1N
Charter - cargo operations
Piper 23 250 VH-MMZ
04 Dec
8511053
Brisbane OLD/Emerald OLD
Blackwater OLD
0340
The pilot had intended to conduct a night freight service to Emerald. There were several thunderstorms in the Emerald area and the pilot
elected to divert to Blac kwater, 70 kilometres to the east.
On arrival in the Blackwater area, the pilot reportedly commenced holding at an altitude about 1700 feet above ground level, whi le he
waited for the runway lights to be displayed . The ai rcraft then entered cloud and severe tu rbulence was encountered . The pilot stated that
his headset was thrown off his head and that he accidently knocked the gear lever into the down position . He said he made no furthe r
control inputs. The aircraft struck the ground in a 40 degree tu rn to the right, at a shallow angle of descent, about 250 metres to the east
of the Blackwater runway. The aircraft rotated to the right and slid for about 150 metres before coming to rest. The maingear, right engine,
aileron and both flaps had been torn from the aircraft during the impact sequence.
iv I Aviation Safety Digest 128
The pilot was carrying out a period of solo circuit training, after having completed three check circ uits w ith an instructor. On the second
landing, the aircraft bounced, then touched down again heavily on the nosewheel. The nosewheel was detached and the 9ircraft ran off
the runway.
Bell 206 B VH-FUT
Spencers Brook WA
Aerial mapping/photography/survey
C lackline WA/Spencers Brook WA
C1F, P1S, P1M
8551033
The helicopter was being used as an airborne filming platform. It was being flown at about 30 feet above ground level along the side of
a roadway, while the film crew fi lmed a bus that was travelling along the road. The helicopter was observed to gain altitude and pass over
a power line then descend again to 30 feet above ground level. After travelling a further 500 metres the he licopter st ruck a spur line running
from the main power line. It somersau lted through the air before colliding with the grou nd.
11 Dec
1945
Conaero LA4-200 VH-XDH
Strahan Tas 18N
Non commercial - company flight
Strahan Tas 18N/Strahan Tas 18N
C1N, P2M
8531025
The pilot had not previously landed at the particular area, but had carried out a detailed inspection to ensure no debris was present in
the water, which was about one metre in depth . Almost immediately after touchdown the nose yawed some 20 degrees to the left and
the aircraft pitched forward and overturned. A subsequent inspection revealed considerable damage to the hull below the cabin floor.
12 Dec
0923
Bell B206-L1 VH-HIL
Black Reef OLD
Charter - passenger operations
Hamilton Island OLD/Black Reef OLD
C1M, P1F, P2S, P2N
8511056
Fou r helicopters had b een arranged to transport twenty-one Hamilton Island resort guests to Black Reef for a boat cruise. At Black Reef
the helicopters were to be landed on a pontoon, which had recently been marked to accommodate th ree helicopters at the one time.
The first helicopter to arrive (a Bell 222, VH-HIA) was parked in the centre position, then shut down with the rotor blades positioned
along the fore and aft axis of the aircraft. The second to arrive was parked to the left of VH-HIA and shut down. The third helicopter landed
and after off-load ing passengers proceeded to a nearby smaller pontoon . The fourth helicopter arrived, parked, and as the pilot selected
idle power he noticed that the forward rotor blade of the adjacent helicopter (VH-HIA) was moving towards the rotor arc of his own aircraft
(VH-HIL). The rotors became entangled and VH-HIL turned violently through 180 degrees. During the manoeuvre two passengers were
ejected from VH-HIL, and the mai n rotors, the mast, and a section of the roof were torn from the aircraft.
Initial investigation has revealed that the rotor brake on VH-H IA was not in the 'park' position.
12 Dec
Rockwell S2R VH-PCE
Aerial agriculture
C1N
1320
Boggabri 14NNW
Gunnedah NSW/Boggabri NSW
8521071
Before commencing operations, the pilot had carried out a detailed survey of the area and noted that a power line crossed the particular
paddock to be treated . On the second spraying run the pilot temporarily forgot the presence of the power line, and the gear legs collided
with the wires. The aircraft subsequently struck the ground in a steep nose-down attitude and cartwheeled for 30 metres before com ing
to rest w ith only the cockpit area still intact.
13 Dec
Cessna A188B A1 VH-UDV
Aerial ag riculture
C1N
1200
Koo Wee Rup Line
Nar Nar Goon VIC/Nar Nar Goon VIC
8531026
The pilot was spraying a potato crop in a paddock which had a power line running along one boundary. Spray runs were conducted at
right angles to the wires, and the pi lot was flying under the wires on each run. At the end of one run the pilot pulled up, conducted a
procedure turn, and was then slightly distracted by noise on his CB radio. While adjusting the squelch on the set, he forgot the presence
of the power line and the aircraft struck the wires about 32 feet agl. The aircraft remained under control and the pilot was subsequently
able to make a normal landing at his destination strip.
13 Dec
1225
Aerospat SA341G VH-PWS
Mt Perisher NSW
Non commercial - aerial application/su rvey
Mt Perisher NSW/Perisher Valley NSW
C1M , C1N
8521072
The helicopter was being used to transport empty fuel drums from a dump at an elevation of about 6500 feet on the summit of the mountain
to the val ley floor. One load of 5 drums had been successfully lifted about 10 minutes previously, and the pilot returned to sling-load a
further 4 drums. He subsequently reported that as he began to lilt the drums he detected a change in the engine note. The load was immediately
jettisoned , but the engine continued to wind down and the pi lot was committed to a landing in a confined clearing. Full collective was
applied to arrest the forward speed and the aircraft landed heavily. After the helicopter had come to rest the pilot extinguished a small
fire wh ich had broken out at the rear of the engine compartment.
15 Dec
1600
Comwlth 28 C VH-SSY
Wangaratta VIC
Non commercial - aerial application/survey
Wangaratta VIC/Wangaratta VIC
C1N , P1N
8531027
A fly-in had taken place to the site of an aviation museum. At the conc lusion of the organised activities, it was decided to position the
Ceres in such a man ner as to allow it to be photographed against the background of the museum hangar. Shortly after start-up, the engine
stopped of its own volition , and after the restart it faltered again prior to a normal takeoff. Du ring the flight the engine again lost power
and the pilot was committed to a forced landing. The only area suitable for landing had a group of Tiger Moth aircraft at the far end , and
after touchdown the pilot initiated a groundloop in order to avoid these aircraft. The left gear leg collapsed and the aircraft slewed to a
stop short of the parked aircraft .
17 Dec
2016
Beech 95 B55 VH-EHN
Bankstown NSW
Charter - cargo operations
Moruya NSW/Nowra NSW
C1N
8521073
On arrival in the destination area the pilot was unable to obtain a down and locked indication for the landing gear. An inspection from
another aircraft indicated that the left gear was only partially extended and the pilot elected to divert to Ban.kstown . All further efforts to
lower the gear fully by normal or emergency means were unsuccessful, and the gear ultimately jammed in the m id-position. A safe landing
was subseq uently made, w ith the aircraft touching down on a grass undershoot area and sliding to a stop on the selected runway.
Aviation Safety Digest 128 I v
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure/Destination
Injuries
Record number
FINAL REPORTS (The investigation of the following accidents has been completed.)
18 Dec
1400
Piper 25 235 VH-MCH
Lismore NSW 19SW
Non commercial - aerial application/survey
Lismore NSW/Lismore NSW
C1N
8521074
Date
Time
Pilot licence
The pilot was carrying out a survey of various properties he intended to spray in the near future. While climbing to return to Lismore after
surveying the last property, the engine suddenly ran roughly and then stopped. The pilot was committed to a forced landing on unsuitable
terrain, and the.aircraft collided with a wind-row of fallen trees 146 metres after touchdown. A fire then broke out and engulfed the wreckage.
19 Dec
1625
Cessna 182 P VH-TSA
Miles OLD 2NE
Non commercial - pleasure
Miles OLD 2NE/Miles OLD 2NE
20 Dec
1715
Cessna 404 VH-BPM
Townsville OLD
Charter - passenger operations
Townsvi lle OLD/Palm Island OLD
04 Oct
1203
Private
Initial investigation has revealed a loose fuel line union in the right wing just outbo"ard of the engine.
Non commercial - pleasure
Mittagong NSW/Pt Macquarie NSW
Piper 25 235 VH-CKL
Meande r TAS
Aerial agriculture
Meander TAS/Meander TAS
C1N , P5N
8521075
Pazmany PL4-A VH-URR
Parafield SA
Non commercial - practice
Parafield SA/Parafield SA
27 Oct
1440
Commercial
C1N
8531029
Cessna P206 VH-MYD
Katoomba NSW 2N
Charter - passenger operations
Katoomba NSW 2N/Katoomba NSW 2N
Burkhart Astir VH-WG L
Parkes NSW 30N
Non commercial - pleasure
Forbes NSW/Forbes NSW
C1N
8541026
30 Dec
1800
Rolladen LS3 VH-WUR
Forbes NSW
Non commercial - pleasure
Forbes NSW/Forbes NSW
An instructor who was watching the aircraft as it entered the circuit estimated that the aircraft was about 200 feet too low on the downwind
leg. The base turn was conducted at about 50 feet and during the turn onto final the wing of the glider struck the strip boundary fence.
A subsequent examination indicated that the glider altimeter was over-reading by some 200 feet.
31 Dec
1420
Cessna U206 G VH-SHO
Brisbane OLD 61NW
Non commercial - pleasure
Archerfield OLD/Somerset Dam OLD
C1M, P3F, P1M
8511060
24
Non commercial - pleasure
Walkam in OLDfTully OLD 13WNW
3375
2975
Instrument
rating class 4
C1N , P1N
8511049
37
Charter - Passenger operations
Batchelor NT/Pt Keats NT
4500
1250
Instrument
C1N , P3N
rating 1st class 8541025
or class 1
The pilot reported that as the aircraft was climbing through 3000 feet it suffered a bird strike. The aircraft was landed at the departure
aerodrome without further incident. The bird, an eagle, became embedded in the vertical stabiliser.
13 Nov
1103
Commercial
Beech 95 B55 VH-MLC
Hunthawang NSW
54
Charter - passenger operations
Narrandera NSW/Hunthawang NSW
16285
5215
Instrument
C1N , P1N
rating 1st class 8521063
or class 1
Shortly befo re the aircraft landed a tractor had fi nished slashing the strip. The driver had not noticed any soft areas, and the strip appeared
to be of a uniform colour. As the aircraft decelerated to about 20 knots during the landing roll, the nosewheel suddenly broke through the
strip surface and sank to a depth of some 30 cm . Shortly afterwards the wheel snapped off near the bottom of the strut, which then folded
rearwards and the aircraft skidded to a halt on its nose.
C1N
8521076
C1N
8521079
Hughes 269 C VH-FHJ
Tully OLD 13WNW
11 Nov
Cessna 402 C VH-ANO
1540
Batchelor NT
Senior commercial
C1N, P4N
8521077
The pilot was carrying out a cross-country flight when sink conditions were encountered and an outlanding became necessary. The pilot
was making his approach parallel to trees on the side of the intended landing area, when the right wing struck a small tree. The glider
rotated 90 degrees to the right before coming to rest.
C1N , P2N
8531019
The pilot had not previously landed at th is property, and was unaware that the tarpaulin had been left on a loading ramp. It had evidently
been lifted into the air by rotor slipstream and had then fallen into the rotor disc. This caused one blade to become partially detached ,
with resulting imbalance of the rotor system and a short period of ground resonance.
During the pre-landing checks, the pilot noted that no pressure was available from the left brake pedal. The strip has a slight slope, and
the pilot elected to land up the slope in light quartering tailwind conditions. The aircraft bounced twice after touchdown and the pilot commenced
a go around. The aircraft veered off the strip and collided with several trees before coming to rest 50 metres from the centre of the strip.
29 Dec
0630
Instrument
rating class 4
The pilot advised that during the approach he did not notice a piece of blue plastic tarpau lin in long grass adjacent to the landing area.
As he lowered the collective control after touchdown, there was a loud bang and the aircraft began to shake violently. Main rotor rpm had
virtually ceased before the pilot was able to shut down the engine. As the aircraft became stationary the pilot noticed a piece of the tarpaulin
was attached to one of the main rotor blades.
The pilot had built the single seat aircraft himself and had previously only flown it on one occasion. After completing the first circuit, the
aircraft was taxied back to the threshold and the second takeoff commenced. Just after liftoff the aircraft was observed to pitch nose up.
The right wing dropped and the aircraft turned to the right before impacting the ground.
29 Dec
1430
36
Non commercial - pleasure
Longdown TAS/Fernleigh VIC
340
60
The right gear did not fully retract or extend because of damage sustained by the retraction mechanism, probably as a result of ground
contact after the down lock had been released . The cause of the partial power loss reported by the pilot was not determined.
The pi lot was sprayi ng a small paddock, to the south-east of which the ground rose steeply. All spraying runs were being conducted towards
the south-east, with the pilot carryi ng out left-hand orbits at the end of each run in order to reposition the aircraft. However, manoeuvring
in this manner was taking the aircraft close to houses in a noise-sensitive area. The pilot therefore decided to carry out a procedure turn
and conduct a run into the north-west. About half way around this turn the aircraft lost performance, probably as the resu lt of a downdraught,
and then stalled at about 100 feet above the ground. There was insufficient height avai lable for the pilot to effect recovery and the aircraft
struck the ground in about a 30 degree nosedown attitude.
27 Dec
0746
Piper 24 400 VH-EDM
Launceston TAS
The pilot reported that as the aircraft became airborne, he noticed a loss of engine power and believed the aircraft may have touched
the ground after the landing gear was selected up. He was subsequently unable to obtain a gear down and locked indication, although
the gear appeared to ground observers to be fully extended. During the landing roll the right main gear collapsed.
VVhile cruising at 3000 feet, the aircraft suddenly encountered strong turbulence. Almost immediately afterwards, the engine commenced
to run roughly and the pi lot was unable to maintai n height. He intended to carry out a precautionary landing on a freeway, but then sighted
a strip nearby and positioned the aircraft for a left circuit. He subsequently advised that he elected not to lower the landing gear because
he considered that the aircraft would have rolled beyond the end of the 550 metres long sealed strip. The aircraft tGJuched down some
350 metres beyond the threshold and slid for 134 metres before coming to rest.
26 Dec
1530
Rating
Injuries
Record
Number
The loss of eng ine powe r resulted from a design defect with in the aircraft fuel system. Wear in the internal valves of the engine-driven
fuel pump caused valve seats to move off centre and stick open. This allowed fuel under pressure to be recycled back to the inlet of the
electric fuel pump and resu lted in a loss of fuel pressure to the carburettor. The loss of fuel pressure may have also resulted in fuel<Vapour
locks forming downstream of the electric fuel pump which had been selected 'on' prior to takeoff.
C1N, P11 N
85211058
As the pilot was applying power at the commencement of the takeoff ru n, the right engine lost power. An explosion was then heard from
the vicinity of the right engine. The pilot secured the engine and after stopping the aircraft, evacuated the passengers before leaving the
aircraft himself. He then noticed a small fire under the right wing which he extinguished with a fire extinguisher obtained from the aircraft.
Cessna R182 VH-ITS
Somersby NSW
Age
Kind of flying
Departure poinVDestination
Hours total
Hours on type
02 Oct
Piper 24 250 VH-MCD
Non commercial - pleasure
C1N,' P2N
1527
Fork Lagoon OLD
Fork Lagoon OLD/Craiglands OLD
8511045
Private
42
920
870
None
When the aircraft was at about 50 feet above ground level after takeoff, the engine lost power, recovered to full power, then lost power
again. The pilot commenced an approach for a landing, straight ahead. During the approach the engine again recovered power, the pi lot
· closed the throttle and landed the aircraft in a tree strewn paddock. The left wheel struck a dead tree lying in the paddock and the aircraft
groundlooped before coming to rest.
C1N
8511057
As the aircraft was being taxied for takeoff, the nosewheel struck a small termite mound. The nosegear was broken off and the aircraft
came to rest on the lower engine cowl.
21 Dec
1245
Aircraft type & registration
Location
f
I
The strip was in regular use, however this had been the first landing since isolated heavy rain had failed over the area two days previously.
It was probable that the rain had affected a small section of the strip, but not to the extent where the soft patch was detectable by aerial
or ground inspection.
17 Nov
1910
Private
Beech A36 VH-RNM
Lilydale VIC
37
Non commercial - pleasure
Hay VIC/Lilydale VIC
200
26
C1N, P4N
8531024
None
On arrival in the destination area the pilot encountered deteriorating weather conditions, including rain and turbulence. Strong sink was
experienced on the base leg of the circuit and the pilot found it was necessary to increase power and raise the landing gear in order to
maintain adequate control of the aircraft. The approach was continued but the pilot forgot to re-select the gear down. The warning horn
sounded just before ground contact and the aircraft slid to a halt on the strip.
The flight had been arranged by one of the passengers as a scenic joy flight. The aircraft departed Bribie Island and landed at South
Stradbroke Island, where the occupants had lunch. After departing South Stradbroke Island, the aircraft landed at Archerfield to refuel
before proceeding to Somerset Dam where it was intended that the passengers have a swim before returning home.
18 Nov
1200
Commercial
As the ai rcraft was approaching to land on Somerset Dam, witnesses observed that the four wheels were extended. When the aircraft
alighted on the water it immediately nosed over and sank, then floated inverted under the water. The pi lot surfaced and immediately dived
down to the aircraft and freed one of the passengers. However the efforts of the pilot and others were unsuccessful in rescuing the remainder
of the occu pants.
The pi lot was carrying out the first spraying run in the particular paddock. Towards the end of the run he was distracted when a large flock of bi rds
suddenly flew up in front of the aircraft. The pilot descended in order to fly under the birds, but temporarily forgot that there was a power line in
the vicinity. As he pulled up at the end of the run , the main gear snagged the wire. The wire cutters fitted to the gear did not sever the wire and
the aircraft subsequently struck the ground 82 metres beyond the run of the power line.
vi I Aviation Safety Digest 128
Piper PA36-375 VH-JND
Griffith NSW 26SW
30
Aerial agriculture
Griffith NSW 26SW/Griffith NSW 26SW Agricultural
5700
200
class 1
C1M
8521064
Aviation Safety Digest 128 I vi i
�Date
Time
Pilot licence
Aircraft type & registration
Location
26 Nov
Piper 601 VH-CUO
1745
Macksville NSW 6E
Senior commercial
Age
Kind of flying
Departure point/Destination
Hours total
Hours on type
Injuries
Record
Number
Rating
26
Charter - cargo operations
Macksville NSW 6E/Sydney NSW
3150
25
Instrument
C1N
rating 1st class 8521066
or class 1
During the takeoff roll the right mainwheel entered an area of soft sand and sank to a depth of 230 mm. The resultant loads applied to
the scissor link caused it to fail and the wheel swivelled through 180 degrees. This in turn produced flexing of the gear leg, the downlock
disengaged, and the leg collapsed. The aircraft swerved to the right and came to rest just outside the flight strip.
The pilot and the operating company were aware that soft areas were present on the strip. The pi lot had landed and departed again
during the morning without undue problems, and had made an uneventful landing shortly before this particular takeoff attempt. However,
on this occasion wind conditions dictated a takeoff in the opposite direction to that employed earlier in the day and a soft area was encountered
at a speed of about 50 knots.
30 Nov
1830
Commercial
Ayres S2R:f15 VH-WBE
Tarcoola NSW
36
Aerial agriculture
Moree NSW/Moree NSW
6514
2100
Agricultural
class 1
42
Instructional - check
Cuda! NSW/Cudal NSW
2000
10
ClN
8521069
None
The pilot was a member of a group of Chinese ex-military pilots who were being trained to allow them to reach the equivalent of an Australian
agricultural rating. He had almost completed this course and was being checked on a simulated spraying exercise by an Exam iner of Airmen
watching from the ground . The pilot, who did not speak English, was being provided with instructions via an interpreter.
At the completion of the check, the pilot intended to carry out a normal landing into the east. However as he was about to tu rn downwind,
he was advised to "come back quickly". A steep turn was made to position the aircraft on a low and close base for landing into the west.
The final approach turn was overshot, and during the attempt to line up with the strip the aircraft stalled, struck the ground heavily and
overturned.
The instructor supervising the training of the pilots had noticed that thunderstorms were developing about 20 kilometres south of the
strip. He had asked the interpreter to advise the remaining pilots not to waste time during their respective flights, in case the storms moved
closer. The interpreter, who did not have an aeronautical background, had misconstrued the message and had passed the instruction to
return quickly to the pilot. During the modified approach the pilot had not monitored the ai rspeed and had insufficient height available
to recover control when the aircraft stalled.
20 Dec
1700
Student
Cessna A152 VH:fHF
Tyabb VIC
34
Instructional - solo (supervised)
Tyabb VIC/Tyabb VIC
12
12
None
The approach and landing had been conducted in light crosswind conditions. While compensating for these conditions, the pilot had
probably inadvertently applied excessive forward pressure to the control column and a "wheel-barrow" situation developed. The elevator
trim was found to be in the takeoff position, which would have compounded the nose-down tendency during the landing roll.
Cessna R182 VH-MOG
Bowen OLD
19
Non commercial - pleasure
Charters Towers OLD/Bowen OLD
137
34
C1N
8511059
None
On landing the aircraft bounced about four times before the nose gear broke off. The aircraft overturned, com ing to rest on the ru nway.
Gusty wind conditions prevailed at the time of landing. When the aircraft bounced on the initial touchdown, the pilot did not take suitable
corrective actions and a "porpoising" situation developed until the nose gear failed .
30 Dec
0950
Student
Cessna 152 VH-SDT
Cooranbong NSW
27
Instructional - solo (supervised)
Cooranbong NSW/Cooranbong NSW
21
8
C1N
8521078
None
Following a dual check , the pilot was authorised to carry out three solo circuits and landings. The first of these was completed satisfactorily,
but on the next landing the aircraft bounced and the pilot applied full power in order to go around. Shortly afterwards the aircraft stalled ,
struck the ground with the nosewheel and the left wing , and overturned. The pilot later advised that he had held the control column fully
back during the go-around attempt, and the flaps had been lowered.
viii I Aviation Safety Digest 128
Age
Kind of flying
Departure point/Destination
Hours total
Hours on type
Rating
Injuries
Record
Number
31 Dec
Transav PL12 VH-MLJ
Aerial agriculture
C1 N
1000
Bridgport TAS 10W
Bridgport TAS 10W/Bridgport TAS 10W Agricultural
8531030
Commercial
22
1820
1000
class 1
,
The aircraft was being operated from a strip wh ich had been cleared in a hay paddock. The pilot was aware that the strip was of marginal
length and had therefore reduced the load to be carried. On takeoff, the aircraft accelerated normally to about 40 knots but the performance
then appeared to stagnate. The pilot attempted to dump the load , but only partial dumping was achieved before the right main gear struck
a fence post as the aircraft became airborne. The impact displaced the gear, however the aircraft remained under control and the pilot
diverted the aircraft to a more suitable aerodrome. The right main gear became completely dislodged during the landing.
A subsequent inspection of the strip revealed that it had a soft sandy surface, covered with short and thick grass. Heavy rain had fallen
in the area during the night and early morning, and the grass was very wet at the time of the takeoff. When calculating the load he cou ld
safely carry from the strip, the pilot had not appreciated the degree to which the surface conditions would affect the takeoff performance.
FINAL UPDATES (The investigation of the following accidents has been completed. The information is additional
to or replaces that previously printed in the preliminary report.)
Date
Time
Aircraft type & registration
Location
Age
Hours total
Pilot licence
Hours on type
Rating
03 Mar 84
0830
Mooney M20 F VH-ERS
Redcliffe OLD
63
1126
Private
910
None
Record
number
8411009
The pi lot reported that prior to touchdown all gear down indications were normal. Shortly alter touchdown the right gear collapsed and
the aircraft came to rest on the right wing tip 6 metres from the edge of the runway.
A subsequent inspection found that the right gear collapsed because it failed to lock overcentre. This was probably caused by the inadequate
lubrication of the landing gear system.
30 Mar 84
1030
Hiller UH12-E VH-FBZ
Muttaburra 52NE
23
80
Private restricted - Helicopter
15
None
8411017
The pilot in command was occupying the rear control position , which did not have tail rotor control pedals, while another pilot flew the
ai rcraft. During the approach to land the pilot-in-command became concerned when the airspeed decayed and he pushed the cyclic control
forward to initiate a go-around . The aircraft yawed to the right, control was lost and the aircraft struck the ground heavily, comi ng to rest
on its right side.
The inexperienced pilot occupying the front
Althou gh he had been instructed to apply left
the helicopter st ruck the ground. Inspection of
This may have also contributed to the loss of
seat had been surprised when the rear seat pilot had taken control during the approach.
pedal, it is likely that his delay in doing so prevented control from being regained before
the aircraft revealed that forward cyclic control movement was limited by incorrect rigging.
control.
C1N
8531028
Following a period of dual instruction, the student was authorised to conduct a series of solo circuits and landings. On the first approach
he lowered 30 degrees of flap and the aircraft touched down normally. After travelling about 50 metres, the aircraft veered sharply to the
left, ran off the side of the strip, and came to rest in a shallow ditch just outside the boundary of the stri p.
21 Dec
0815
Private
Aircraft type & registration
Location
C1N
8521067
The pilot intended to spray a cotton crop. A power line crossed the area at an oblique angle, and at the point where the aircraft passed
under the wire there was a head ditch one metre high, dividing two paddocks. On the first spraying run the pilot misjudged the clearance
under the wire and the mainwheels struck the top of the ditch. The aircraft remained controllable and an uneventful landing was subsequently
carried out at the destination aerodrome. Damage was confined to the gear truss points and shock absorbers.
05 Dec
Transav PL12 T-400 VH-TRX
1230
Cuda! NSW
Other (Foreign, Military, etc)
Date
Time
Pilot licence
05 Apr 84
Cessna A185-F VH-SFS
Commercial
8411019
0645
Cairns OLD 26NNW
32
6500
1700
None
The aircraft had been refuel led the previous afternoon and hangared overnight. When the pilot and passengers arrived the following morning,
the pi lot loaded their baggage and freight into the aircraft . The aircraft was pushed out of the hangar and the pilot carried out a pre-flight
inspection. After the passengers boarded the aircraft the engine was started and an engine check completed before the aircraft was taxied
to commence takeoff from runway 15.
About 12 minutes after takeoff, the pilot reported that the engine was malfunctioning. It subsequently lost power completely and the
pilot was committed to a forced land ing. The sea conditions were unfavourable for the aircraft type, with estimated strong winds and about
a 1.5 metre swell. The aircraft cartwheeled on touchdown and sank almost immediately. The pilot and two of the passengers were able
to free themselves from the sinking aircraft and make their way to the surface. There they supported themselves on the floats which had
become detached from the aircraft during the landing. Their subsequent attempts to locate the aircraft and rescue the other passenger
were unsuccessful. The three men were later rescued by a police boat.
An extensive search of the area , at the time, failed to locate the missing aircraft. About twelve weeks after the accident the engine was
located by a trawler and salvaged. Some six weeks later the airframe was located by another trawler, it was also salvaged. Following the
salvage of each part of the aircraft it was washed down and subjected to extensive exami nation . The immersion of the wreckage in salt
water and the growth of marine life on the wreckage inhibited thi s examination . However, no fault was found that may have contributed
to the accid ent. The investigation did reveal that at the time of takeoff the aircraft was approximately 300 kg in excess of the maximum
allowable all up weight.
04 Jui 84
1421
Piper 32 R300 VH-S BK
Charleville OLD
42
1780
Commercial
350
8411032
Instrument rating 1st class or
class 1
During cruise the pilot noticed that the electrical system was malfunctioning . The ammeter was reading zero, the system was switched
off and a diversion for landing carried out. The pilot reported that , on arrival in the circuit area, the landing gear could not be lowered
by the emergency system. A wheels-up landing was made.
An inspection of the aircraft revealed that the electrical problems were due to an alternator failure which resulted from a faulty connection
on a brush lead. The reason that the gear was unable to be lowered by the emergency system could not be determined.
Aviation Safety Digest 128 I ix
�Date
Time
Aircraft type & registration
Location
Age
Hours total
Pilot licence
Hours on type
Rating
13 Oct 84
1046
Piper PA36-300 VH-FET
Finley NSW 18NE
53
21000
Commercial
420
8421054
Agricultural class 1
Record
number
During the takeoff roll, the pilot noted a loss of aircraft performance, but considered that there was insufficient strip length remaining to
safely stop the aircraft. Shortly after becoming airborne the tail assembly struck the wooden top railing of a bridge. The left wing tip struck
a dead tree 65 metres further on , the aircraft slewed to the left, touched down and came to rest with the engine and landing gear torn
from the fuselage.
No fault could be found with the aircraft systems which may have contrib uted to the reported loss of performance. The takeoff, on a
one-way strip, was conducted with a slight tailwind component and the estimated takeoff weight slightly exceeded the climb weight limit
specified in the aircraft P-chart. T he p ilot's technique to assist in getting the aircraft airborne was to p rogressively select full flap during
takeoff. On this occasion the use of ful l flap ap parently degraded the c limb performance of the aircraft to such an extent that it collided
with the brid ge.
20 Nov 84
1100
Cessna 150 L VH-DIV
Muttabu rra 65NNE
29
2289
Commercial
34
8411053
Instrument rati ng class 4
The pi lot reported that the flig ht was commenced with fu ll fuel tanks. An endurance of over 210 minutes was anticipated with the planned
fuel flow. The engine failed after three hours and the aircraft sustained damage to the nosegear and right wing du ring the ensuing forced
landing. The pilot advised that when he subsequently dipped the fuel tanks there was no fuel remaining .
The pilot had not leaned the mixture correctly, and the consequent fuel flow was greater than he had expected. On previous occasions
he had operated the aircraft for shorter flight periods and had not calculated the actual fuel usage rate.
27 Nov 84
0746
Beech 58 VH-ETV
Maitland NSW
31
3273
Senior commercial
8421068
614
Instrument rating 1st class or
class 1
The pilot advised that when he selected the landing gear down, aerodynamic noises were normal and the main gear green light illuminated.
When he c losed the throttles the warning horn did not sound, however during the landing roll the left gear collapsed and' the aircraft came
to rest on the grass adjacent to the landing runway.
The left gear uplock had failed to release at the approp riate stage of the extension cycle, possibly due to the incorrect fitment of the
uplock release cable attachment bolt. This would have resulted in misalign ment of the uplock assembly when the gear was in the up position .
When the pilot selected the gear down the actuating rod became bent and prevented the gear from ful ly extending. However, the visual
and aural warning systems for the gear are triggered by a microswitch on the actuator assembly, and if this has moved th rough its full
travel the position of an individual gear leg is not necessarily accurately reflected .
21 Dec 84
1715
Conaero LA4-200 VH-AOW
Hook Island QLD
28
1610
Commercial
1310
8411059
Instrument rating class 4
Throughout the afternoon the pilot had flown the aircraft on a number of sorties in the area. During the subject flight the pilot reported
abeam a point on Hook Island, en route to pick up some divers he had dropped off earlier. No further communications were received from
the aircraft.
An extensive search failed to find any trace of the aircraft. A thorough investigation has found no reason for the disappearance of the aircraft.
11 Jan 85
1133
Cessna 172 K VH-RGT
Mittagong NSW 3ESE
Private
45
208
8521003
None
The pilot reported that the aircraft became airborne after a ground roll of about 760 metres and initial climb was commenced at an indicated
airspeed of 65 knots. Soon after lift off the climb performance of the aircraft decayed and the airspeed reduced to 50 knots. Several gradual
turns were made to avoid trees but the aircraft struck trees on rising terrain and impacted with the ground.
Examination of the engi ne revealed that the two front cylinders had been runn ing over-rich . An incorrect model carburettor was found
to have been fitted to the engine. However, it could not be determi ned if this had been the cause of the fuel mixture p roblem.
Local aero club pilots reported that, in this aircraft , with the mixture control in the full rich position, the engine obtained about 200 RPM
less than the optim um. It was well known to club pilots that the mixture control required leaning out by about three centimetres before
takeoff to achieve the correct engine performance. On the day of the accident, the pilot leaned the mixture slightly less than one centimetre.
It is likely that the loss of aircraft performance was the result of reduced engi ne performance caused by an over-rich mixture.
15 Jan 85
0635
Piper 34 200T VH-KG R
Moramana QLD
24
550
Commercial
100
8511003
Instrument rating class 3
After arriving in the area the pilot was unable to locate the destination strip. He decided to land on a gravel road near a house to seek
directions. Shortly after a normal touchdown the nosegear collapsed and the aircraft came to rest in a drain beside the road . The pilot
reported that there had been nosewheel shimmy during the previous takeoff and just prior to the nose leg collapsing.
. The pilot had not previously operated into the strip at his intended destination. The nosewheel tyre was found to be deflated, and it is
likely that it had become deflated during the previous takeoff. However, due to the extent of the damage caused to the tyre during the
landing, it was not possible to d etermine the reason the tyre had become deflated.
20 Mar 85
1233
Cessna 404 VH-UOP
Lismore NSW
Senior commercial
8521022
650
Instrument rating 1st class or
c lass 1
On initial touchdown the pi lot d etected an abnormality with the landi ng gear. An immediate go-around was carried out and the pilot of
another aircraft reported that the left mai n gear was sloping rearwards of its normal alignment. T he pilot was committed to a landing with
the gear in this position and the gear leg subseq uently collapsed at about 60 knots. Initial investigation indicated that the fai lu re of a slotted
pin al lowed the trunnion forward pivot pin to work itself free, with conseq uent misalignment of the gear leg.
30
8300
The pivot pin showed evidence of grinding, apparently carried out during maintenance in order to facilitate the fitting of the pin into its
appropriate socket. However, the grinding also resulted in excessive free play, which allowed the pivot pin to apply bending loads to the
slotted retaining pin and which resulted in the eventual failure of this pin.
x I Aviation Safety Digest 128
L
Date
Time
Aircraft type & registration
Location
Age
Hours total
Pilot licence
Hours on type
Rating
16 Apr 85
1530
Hughes 269 C VH-PHK
Mt Hope QLD
33
650
Commercial 350
helicopter
None
Record
number
8511018
The pilot reported that just after liftoff the engine seemed to lose power. She manoeuvred the helicopter to a suitable landing area, but
during the landing the main rotor blades struck a sapling. The helicopter was then repositioned to another landing site where the engine
was shut down and the damage to the main rotors noticed.
An inspection of the engine revealed that the number two and four exhaust valves had been sticking and that the valve guides were
out of tolerance. It is probable that the loss of engine power was a result of the exhaust valves sticking.
19 May 85
1130
Robinson R22 VH-ON E
Mt House Si n
28
1419
Commercial 694
helicopter
8551012
Instrument rating class 4
After the helicopter had been transitioned to forward fl ight, the pilot felt a vibration th rough both the collective and cyclic cont rol~. Duri ng
his attem pts to stop the vibration, the hel icopter was allowed to descend. As he then selected a climb attitude the helicopter yawed to
the right. The pilot was unable to correct the yaw and the tai l struck a tree which slowed the yawing and allowed the pilot to land the helicopter.
Initial inspection revealed that the intermediate flexplate in the tai l rotor drive system had disintegrated .
A metallurgical examination of the flexplate indicated that it probably failed due to overload. The examination also revealed that prior
to the application of the overload that resulted in the ultimate failure, the flexplate had been cracked and weakened by another previous
overload. The cause of the overload that resulted in the pre-existing crack could not be determined. However, examination of the tail rotor
indicated that the ultimate failure most likely occurred as a result of a minor tail rotor strike whilst the helicopter was transitioning into forward
flight.
29 May 85
0930
Bell 47 GS VH-SJY
Ivanhoe Si n WA
31
2800
Commercial 2550
helicopter
None
8551013
The helicopter was being flown at about 50 feet agl, when one main rotor blade grip failed. The main rotor blade separated from the helicopter
and the resulting imb alance caused the other main rotor blade and transmission to b e torn from the helicopter. The fuselage then fell to
the ground, landing on its right sid e.
The main rotor blad e grip fai led due to a combi nation of fatigue and overload forces. Examination of the aircraft records revealed that
because of an error in the recording of com ponent hours, the 5000 hour service life of the grip had been exceed ed by 687 hours.
Du ring the investigation, inspections of the blade grips on several other helicopters were carried out. Fatigue c racking was revealed
in a significant number of the blade grips inspected. As a result, the man ufactu rer of the aircraft has recommended a reduction in the
service life of the component.
03 Jun 85
1711
Conaero LA4-200 VH-AWY
Shute Harbour QLD
36
10059
Commercial
49
8511023
Instrument rating 1st class or
c lass 1
During the landing roll the aircraft began to swing to the right. The pilot attempted unsuccessfully to correct the swing by applying left
brake and rudder. Because of the likelihood of striking a parked aircraft he then induced a ground loop to the right and the aircraft was
brought to a stop. An inspection of the aircraft revealed that the right maingear had unlocked and the ai rcraft had settled on the right float.
No fault could be fou nd with the landing gear system. The gear collapse was consistent with there being insufficient hydraulic pressure
available to hold the gear locks in position during the landing. The post-accident inspection revealed that the hydraulic pump switch, which
is located next to the electric fuel boost pump switch, was in the off position. It is li kely that the hydraulic p ump switch was inadvertently
selected off after the previous takeoff.
14 June 85
1150
Piper PA30 VH-UOY
Armidale NSW
59
14436
Commercial
379
8521037
Instrument rating 1st class or
c lass 1
The aircraft entered the circuit in preparation for a practice single engine landing. The gear was selected down, however neither pilot checked
that the gear-down light illuminated. The aircraft was landed with the gear retracted and the pilots reported that they then noticed that
the gear motor circuit breaker had popped .
The circuit breaker had probably popped during the previous retraction cycle. During the approach, the pilot under instruction was
concentrating on handling the asymmetric situation, while the instructor was closely monitoring the airspeed and the handling tech niques
being employed. During the landing flare the gear up warning horn operated, but its sound was masked by the louder tone of the stall warning.
21 Jun 85
1422
Piper 32 300 VH-MGQ
Mer Island QLD
27
620
Commercial
120
8511026
None
When the aircraft became low on app roach, the pilot applied power to correct the app roach angle. However this resu lted in a higher than
recommended airspeed and touchdown was not effected unti l 170 metres after the threshold. As insufficient runway remained for the aircraft
to be brought to a stop, the pilot attempted to carry out a grou ndloop. The aircraft skidded sideways off the strip and down a steep incli ne
before coming to rest agai nst a tree.
The pilot had encountered several problems prior to the accident. The aircraft battery had gone flat twice causing delays to the passengers.
The passengers had become irritated by the delays and vented their anger on the pilot. The pilot stated that she was concerned about
starting the engine after the landing and about the time avai lable to complete the schedule before returning the aircraft to the base that
night. She also stated that because of her preoccupation with the above matters she had not planned the approac h and landing.
Aviation Safety Digest 128 I xi
�Date
Time
Aircraft type & registration
Location
17 Aug 85
1610
Cessna U206 G VH-APH
Oodnadatta SA
Age
28
Hours total
Pilot licence
Hours on type
Rating
Record
number
209
Private
9
8541014
Instrument rating class 4
After touchdown the aircraft began a series of bounces. The pilot initially attempted to control the aircraft with the elevators but then applied
full power to go around. However, the aircraft struck the ground in a nose-down attitude tearing off the nosewheel and bend ing the propeller
blades.
~~
Refuelling check
The pilot was relatively inexperienced in the aircraft type. The circuit was poorly judged and resulted in a steep final approach at a low
power setting. Following the misjudged landing flare, the pilot delayed in carrying out a go around.
28 Aug 85
1142
Cessna 180 K VH-APW
Parafield SA
43
2800
Commercial
2
8541015
None
The pilot, who had just purchased the aircraft but had little experience on tailwheel types, had completed two hours of training the previous
day. On the following morning he intended to further familiarise himself with the aircraft, by carrying out a number of circuits. During an
attempted three-point landing the left wingtip struck the runway and directional control was lost. The aircraft veered off the runway and
came to rest outside the flight strip.
The landing on which the accident occurred was conducted in gusting crosswind conditions. The recent train ing received by the pilot
did not include any instruction in crosswind landing techniques.
20 Sep 85
1500
Cessna 150 G VH-RZD
Muresk WA
59
777
Private
450
8551025
None
Earlier in the day the pilot had flown the aircraft from his farm to Muresk. Because no fuel was available at Muresk, he decided to fly the
aircraft to Northam, 13 kilometres to the north. Just after the aircraft became airborne, the engine lost power. The pilot was committed
to landing in a paddock. During the landing sequence the aircraft struck a fence and ran over a depressed roadway, tearing off the nosegear.
The loss of engine power was due to fuel exhaustion. Prior to commencing the takeoff, the pilot did not check the quantity in the fuel
tanks, nor did he calculate the remaining fuel endurance.
22 Sep 85
1210
Cessna A152 VH-FMG
Camden NSW
45
32
Student
32
8521052
None
After flaring too high the student pilot continued with the landing attempt but the aircraft struck the runway heavily then bounced several
times. The nosegear assembly was distorted and the engine support frame was bent.
27 Sep 85
1750
Thorp T18 VH-ELW
Cairns OLD
49
650
Private
500
8511044
None
The pilot-in-command, who was also the owner of the aircraft, was acting as the safety pilot for the other pilot, who had only recently received
training on the aircraft. This was the first occasion on which the co-pilot had flown the aircraft from the right hand seat. He flared the aircraft
too high on the first circuit and was advised by the pilot-in-command that the flare had been commenced too early. As he attempted to
reposition the aircraft closer to the runway it struck the runway heavily and bounced. T he co-pilot inadvertently closed the throttle and
the aircraft struck the runway in a nose down attitude. Damage was caused to the propeller, engine firewall and the gear.
29 Sep 85
1415
Cessna 185 A VH-AG I
Hillman Farm WA
38
1400
Private
60
8551026
Instrument rating class 4
At the conclusion of a parachute dropping sortie, the pilot landed the aircraft at the strip in a strong crosswind. During the landing roll
the aircraft began to swing to the left and the right gear leg collapsed . The right wing, tailplane and elevator were bent after contacting
the ground.
The aircraft was one of four operating from the strip when the wind backed and increased in strength during the passage of a weak
front. The pilot had been aware of the change in wind velocity attempting the landing.
xii I Aviation Safety Digest 128
Through this article I hope to impress upon all readers
of the Digest the importance of completing a fuel check
after every refuelling. One that I carried out almost
certainly saved m y two young sons and m yself from a
serious accident.
The incident which happened to me could happen to
anyon e. It was a perfect flying day, blue skies, n il
wind, clear crisp morning and a very enjoyable flight
until the incident. I was ferrying a Hiller UH12
helicopter through N.S.W . with my two small sons as
company and we stopped at a major northern N.S.W.
airport for fuel. We had just landed when an F27
Friendship arrived on a scheduled flight. As soon as the
F27 parked t he refueller b egan to top it up . I told him
that I was in no great hurry and asked him to fill my
helicopter when he finished the Friendship. We left
him to it and refreshed ourselves with drinks, and had
a chat to the locals. As soon as the refueller finished
the Friendship and it had departed for Sydney, he
refuelled the helicopter. We fin alised all the paperwork
(a mistake on my part as I never took any notice of
what type of fuel he recorded on the docket), and then
he proceeded to pack up and go home. The nearest
township was 12 km away by road .
I started to have a look over the helicopt er before
continuing our planned flight; th is inclu ded a water
check , which I do before every flight. What d id I find?
To my shock and horror the fuel was the wrong colour.
The refueller had finished the Friendship and
continued on to fuel the helicopter from the same t ank,
i.e. with Jet Al instead of Avgas. This could have
been disastrous. I estimated we would have just been
airborne when we would h ave had an engine failure
due to the wrong fuel. The airport is surrounded by
thick scrub, and the thought of doing an 'au to' into
that with m y two small sons on board was frightening
to say the least.
This incident just should not happen, as surely
someon e wh o holds the responsible position of
refuelling aircraft should have some id ea regarding
what type of aircraft takes what type of fuel. There is a
big difference b etween Avgas and Jet Al fuel;
additionally, I was annoyed because the Hiller had two
placards at the fuel tank , one on the side of the
helicopter near the ta nk, and one on the filler flap and
cap, indicating the fuel type, yet the refueller still put
th e wrong type of fuel in. H e was sorry, but it's a bit
late when you h ave an engine failure into trees. We
had to travel to town, borrow some hoses etc. from a
local fuel depot and completely drain th e helicopter of
its full tank of fuel. This was not only an expensive
exercise, but it also delayed our flight until the
next d ay.
Another mistake I made was the reluctance to report
th e occurrence with a 225. This incident happened
approximately 18 months ago , and the more I th ink
about it, the more I realise I should have reported it
straight away. A timely report may prevent the same
refueller from doing the same thing again and causing
a serious accident.
The two main points I would like to make are the
importance of water checks a t all times and the use
and value of 225s.
*
*
*
Comment
The pilot's anger with the refueller is understandable as
this incident was attributable solely to n egligen ce. At
the same time , pilots must appreciate that , in the final
analysis, whatever gets· pumped into an aircraft's tanks
is the p ilot-in-command's responsibility. It is a sound
p ractice always to look at the tanker as it pulls up,
read its decals to ensure that it contains the type of fuel
you want, and check t he colour of the liquid as it first
comes out. Don't be shy-it is a fact of life that
refuellers do occasionally make mistakes, a n d it's
your hide you are looking after by taking a few
simple precautions.
The matter of submittin g a 225 is fully endorsed by
the Digest . Reporting a safety occurrence is not
'dobbing' someone; on the contrary, as this reader
commented, it may be a means of saving someone
else's life •
Aviation Safety Digest 12 BI 15
�•Over 90 species of birds
are known to have been
struck by aircraft in
Australia.
Strike one - you're out!
....
Have you ever wondered what is going through a bird's mind when it finds itself eyeball to eyeball with
an object many times larger, thousands of times heavier and travelling, oh .. . 20 times as fast? We
can't really answer that because we haven't yet learned how to plumb a bird's mind. But we do know
something about those feathery creatures with which we have to share the sky, and with which we
occasionally have traumatic and even fatal (for both parties) encounters. Herewith, then, are a few things
you ought to know about birds, if you are going to share their domain - and try to reduce the
birdstrike hazard.
•A snake at 3000 ft AGL
A chicken at 800 ft AGL
A mouse at 8000 ft AGL
A flying squi rrel at 5000 ft AGL
•About ten per cent of
birdstrikes to civil aircraft
result in damage costing
an average of $1-2m each
year .
•Most commonly struck birds
include kites , hawks, gulls,
plovers and galahs .
•Even a few small fragments of
feather can be sufficient to
identify the bird species
involved.
• Birds will usually dive to
avoid collision with aircraft.
• The first recorded birdstrike
accident occurred in 1912. A
seagu ll got caught in the
aircraft control cables. In the
resulting crash the pilot was
killed.
•The heaviest Australian birds
that fly weigh in excess of 8
kilograms and include
pelicans, swans and
bustards.
~i.
(~1"
2··· (<J
(
•In 1984 there
were 585
reported
birdstrikes in
Australia .
•The impact force of
a 2 kg bird at 135
knots is 3.8 tonnes.
•Australian airlines report
about one birdstrike
per 2000 aircraft
movements.
• The highest recorded birdstrike occurred
at 37 OOO feet.
•Even a single bird of about
500 g is capable of destroying a
jet engine.
•The longest
migration route
for any bird is
that of the arctic
tern, (12 OOO
miles ... arctic
to antarctic).
•Ninety-seven per cent of
reported birdstrikes occur on
or in the immediate vicinity of
aerodromes .
ftThe greatest mass of birds hit by an
aircraft in Australia was 6 swans approx. 34 kilograms!
Please report all birdstrikes - remember, without accurate and comprehensive data the birdstrike hazard
reduction program cannot be effective •
16 I Aviation Safety Digest 1 2 8
A viation Safety Digest 1 2 BI 17
�What is to be done?
Several years ago a PA23-250E was involved in a fatal
accident at Fua'amotu International Airport at Tonga
following an emergency landing. The Aztec pilot had
been unable to extend the landing gear safely - the
nosewheel would not lock - so he elected to make the
landing on the mainwheels. On final approach he
feathered the propellers in accordance with the advice
in the aircraft owners handbook that: 'The propellers
should be feathered and stopped in a horizontal
position prior to contact with the ground'.
When the aircraft touched down , the nosewheel
collapsed, the PA23 overturned , and one of its
passengers later died from injuries received.
Apparently the Aztec's propellers were still rotating
when it touched down. Because they were almost
feathered, they were less prone to bend following
contac t with the runway, and so substantially increased
the PA23's tendency to overturn once the nose landing
gear collapsed.
This raises the question of wheth er the propellers
should in fact be feathered before an emergency
landing in which the undercarriage is suspect. That
question is discussed in this article. Note th at the
discussion is restricted to two-blade propellers: under
the particular circumstances there would be no point in
feathering a three-blade propeller.
Feathering factors ·
There are a number of points to consider. In relation
to the accident mentioned above, the most crucial
safety aspect was that of the possibility of overturning.
A feathered propeller which is not horizontal presents
its strongest section to the direction of impact: the
force needed to bend th e propeller should it dig in is
tremendous. Because of this, if the undercarriage does
collapse and a blade does dig in, the probability of the
aircraft overturning is considerably increased. Even if
the aircraft does not capsize, a serious loss of
directional control may occur. On the other hand, if
the propellers are left in the fine pitch position they
18 / Aviation Safety Digest 128
will more easily bend on contact with the ground , so
the overturning or yawing force will be m inimal.
Pilot workload is another factor to consider. The
action of feathering a propeller, and then trying to
motor it to the h orizontal position, can cause a highly
undesirable diversion of atten tion from the primary
task of effecting a safe landing. Any pilot carrying out
an emergency approach will already be under some
pressure. The last thing needed is to have to divert
attention to an action which is not essential. There is
no point in turning an emergency landing into a forced
landing in the case of a single, or an asymmetric
landing in the case of a twin, by shuttin g on e down in
the air.
As far as asymmetry is concerned, experience has
shown that the propellers of light twins may not always
feather . Even if they do , it is rarely simultaneous.
Unexpected yaw may result, the pilot may be taken by
surprise by this occurrence, and so problems may
mount . ..
If the propellers do feather as advertised, the
som ewhat sudden reduction of drag can cause
u nexpected problems. This was the experience of a
Seneca p ilot who carried out an undercarriage-related
emergen cy landing at Moorabbin several years ago. As
he later stated, 'I learned a valu able lesson here .. . I
was a little hot when I feathered them and the aircraft
accelerated'. The P A34 in fact floated a considerable
d istance before the pilot was able to put it on the
ground .
Finally, once feather action has been taken, the
option for a missed approach has been removed. As
wheels-up (and possibly flapless) landings are not
practised , a m isjudged approach must a lways be likely.
In any event, it is not d ifficult to imagine numerous
circumstances which could necessitate a late go-around.
If, however , you have already stopped the propeller/s
from going around , then you have burnt your bridges.
Birdsfrilfcs- a scicnfitic approach
With the opening of a new laboratory in Canberra,
the Department of Aviation has been able to use
science more effectively to reduce the hazard of
birdstrikes to aircraft.
Birdstrikes remain a serious problem which
requires constant vigilance and effort to keep birds
away from airports. Any loss of engine power or
obstruction of the pilot's vision during takeoff or
landing due to birdstrike on an engine or windscreen
can have serious consequences.
As well as the safety aspect, birdstrikes are often
expensive. The cost to operators in repairs and lost
revenue in 1984 exceeded $ 1 million; while in one
accident alone in 1982, $1.5 million worth of
damage was done to a Boeing 747 when it flew
through a flock of pigeons at Melbourne Airport.
One of the key factors in attempting to minimise
the bird hazard is that of determining what attracts
particular species of birds to particular locations.
The laboratory h as added a new dimension to the
Department's capacity to research this matter. It has
also greatly enh anced the identification of bird types
- birds can be identified under the microscope even
from a few feather fragments taken from an aircraft
engine. This, too, is a crucial aspect, as the first step
in removing attractions around an airfield is to
determine the types of birds present.
To a large extent, however, the safety program
remains only as good as the information provided by
pilots wh o h ave a birdstrike. In about 25 per cent of
birdstrikes, especially those occurring en route or at
night, th ere is no identification at all of the bird
involved. This situation will improve only if all
evidence of a birdstrike (e.g. feathers adhering to
aircraft parts) is forwarded to the Bird Hazard
Investigation Laboratory for examination. Such
material can be forwarded through the Airport
Safety Officer or Flight Service staff at any
government aerodrome.
In 1984 the Department of Aviation received 585
reports of birdstrikes, most of which occurred near
airports. The continued support of all pilots is
essential if this important safety program is to be
fully effective •
What is to be done? (contznuedJ
Conclusion
It is often unwise to be inflexible about operational
procedures. Emergency landings have been carried out
in the past in which the p ropellers were feathered,
motored to the horizontal, and the approach completed
with minimal damage to the aircraft. In such instances,
the pilot has exercised his own professional judgment
and skill in the prevailing circumstances.
However, in terms of generalised flight safety, it
remains valid to discourage the average pilot from
taking feathering action when faced with the type of
emergency landing discussed here.
Those responsible for the various training
organisations should consider an a ppropriate
amendment to th e current flight manuals concerned to
allow the pilot-in-command to take a different course
of action. One suggestion is to:
•Select the longest hard-surface runway available,
into wind.
•Do not feather the propeller/ s.
•Approach with the recommended flap configuration
at the correct speed and with power on .
•When happy with the flare and hold-off, and just
before impact, then, and only then, pull the
mixture controls to idle cut-off. (This will offload
the power being delivered to the propellers. As
the propeller tips contact the ground they will
stop turning instantly, and, being in fine pitch,
the tips will usually bend back. With no power
being delivered to the propellers , any damage to
the engines is likely to be minimal.)
•Turn off the fuel and electrics when the aircraft
stops •
Aviation Safety Digest 12 BI 19
�Excessive approach speed
Like many of the articles presented in the Aviation Safety Digest this one addresses a common problem
which is essentially simple to resolve. Further, like many of those articles concerned with pilot technique,
the solution ·is simple - observe the basics.
The accidents
After a routine flight a Mooney M20F arrived at its
destination, a 750 metre homestead airstrip (Figure 1).
The pilot did not see the wind indicator (which, as it
happened, was giving an erroneous indication anyway)
and assessed surface conditions as calm. In fact, there
was a 5-8 knot tailwind component on the strip he
selected.
A go-around was initiated on the first circuit from
very short final approach when it became apparent that
the Mooney was drastically overshooting the aiming
point.
On the second attempt, even though the approach
aspect appeared only slightly better than the first, the
pilot elected to continue to land.
The M20 was flown onto finals at 80 knots, with the
intention of reducing speed to 75 knots. This was
excessive. For the particular landing configuration, the
flight manual stipulates a speed of 68 knots; thus, the
pilot was planning an approach in the order of 10 per
cent faster than that recommended.
Touchdown was made about 200 metres into the
strip. The Mooney began to 'porpoise' (i.e. bouncing
from the nosewheel onto the mainwheels, then back on
to- the nosewheel, and so on), and did so seven times
before the mainwheels settled on the surface. Heavy
braking was applied for 50 metres and the aircraft
skidded for a further 50 metres, at which stage the pilot
decided to go around. This was unsuccessful. After
over-running the strip the aircraft struck a number of
obstructions and was substantially damaged before it
came to rest.
*
*
*
In the second accident, a Cessna 172 was flying in to
an 811 metre bitumen ALA . Landing weight was
later calculated as being about 10 kg over the maximum
limit. Surface wind velocity was about 8-10 knots from
the right and was almost all crosswind.
Because he knew his aircraft was heavily loaded, and
was concerned by the crosswind plus possible turbulence,
the pilot selected an approach speed of 70-75 knots.
This was more than 10 knots in excess of that
recommended.
The touchdown was made a short distance in from
the threshold but the aircraft skipped, floated and then
bounced five or six times.
As was the case in the Mooney accident, the decision
to go around was left too late, and when the Cessna
became airborne just before the end of the runway it
was with the stall warning horn blowing continuously.
The 172 was unable to clear the airport boundary fence
and it, too, sustained substantial damage in the ensuing
accident (Figure 2).
20 I Aviation Safety Digest 128
Discussion
One aspect of piloting which is always properly
emphasised is that of not stalling an aircraft
inadvertently. Obviously, one of the most important
times to maintain a safe flying speed is during the
landing approach: it is absolutely essential. Nevertheless,
building in a 'few knots here' and a 'few knots there' in
an attempt to compensate for perceived difficult landing
conditions, but without reference to performance data,
can lead to difficult control problems.
As the two accident briefs indicated, an excessive
approach speed can sometimes culminate in
'porpoising'. When porpoising starts instant action is
called for. The techniques required and .options
available to a pilot in this situation were covered in the
article 'Bouncing to an accident' which appeared in
A uiation Safety Digest No. 117I 1983.
Another consequence of approaching too fast can be
'wheelbarrowing'. To prevent an aircraft which has
landed at high speed from becoming airborne again, a
pilot may deliberately hold it on the runway with a firm
forward pressure on the control wheel. With the aircraft
still travelling at high speed, the wings will continue to
produce considerable lift, especially with flap extended,
even though the wheels may be in contact with the
ground. This effect, combined with down-elevator or
'stabilator' control, will tend to lighten the load on the
main wheels and, if the speed is high enough, may even
raise them clear of the ground. In these circumstances
most, if not all, of the aircraft's weight is thrust on to
the nose, resulting in the highly unstable
'wheelbarrowing' situation.
Wheelbarrowing often leads to loss of directional
control, with the aircraft running off the side of the
runway and, at the least, damaging the undercarriage.
Porpoising and wheelbarrowing are sufficient
problems in themselves. However, perhaps the cardinal
'sin' associated with high speed landings is that of
floating and over-running. An excessive landing float has
all kinds of serious implications, including the demand
for subsequent heavy braking and the hazards of possibly
going off the far end of the strip. The Mooney accident
cited above provides a good example of this.
The mathematics of landing with excess speed all
work against the pilot. In general terms, double the
speed will give four times the kinetic energy which must
then be dissipated by braking, and which is clearly going
to increase substantially the landing distance required.
In the case of the Mooney, and taking into account both
the excessive approach speed and the tailwind
component, the pilot was flying about 35 per cent faster
than his optimum approach speed. The implications for
his landing distance required are obvious. On the other
hand, had he been at the recommended approach speed
and landing into wind, there should have been no
Figure 1
difficulty in stopping safely.
Advice in manufacturers handbooks regarding
approach speeds can vary. For example, the Cessna
l 72N Information Handbook consulted during the
preparation of this article advises that 'Slightly higher
approach speeds should be used under turbulent wind
conditions', but makes no comment on increasing speed
in a crosswind. The M20 Operators Manual contains
the advice that 'When high, gusty winds prevail, or
when landing crosswind, approach at a higher airspeed'.
The only authorised performance data for Australian
aircraft is that derived from the performance charts,
contained in the official flight manual for each aircraft ,
issued by the Department of Aviation. Approach speeds
given in those 'P-charts' for GA aircraft are based on
•... an approach to land at a speed not less than 1. 3Vs
maintained to within 50 feet of the landing surface'. In
other words, a margin of about 30 per cent over the stall
speed is provided. Therefore, in most conditions pilots
need only to fly that recommended speed accurately to
achieve the correct, safe touchdown speed, with no fear
of stalling.
This does not, of course, mean that approach speeds
should never be increased to cater for difficult
conditions. Gusty winds are the prime example; when
they prevail it is often sound practice to add several
knots to guard against the possibility of a sudden loss of
airspeed.
However, it is not sound practice to increase airspeed
to the extent that the types of problems described above
are created. A number of factors should be considered,
and will include
• the strength of the wind gusts
• crosswind component
• airstrip length
• the aircraft's certified crosswind capability
• pilot currency and experience.
If, after assessing those factors, landing conditions are
still considered safe, then a generally accepted method
for increasing the approach speed is to add 50 per cent
of the gust factor to the normal approach speed. Thus,
if the wind is 15 knots gusting to 25, the gust factor is
10 knots so the approach speed should be increased by 5
knots.
Figure 2
If circumstances are such that a pilot feels a large
increase in approach speed is necessary to retain safe
control of his aircraft, then perhaps it is time to
reconsider the wisdom of even landing at the particular
airstrip.
Conclusion
Flying an excessive approach speed can lead to serious
aircraft performance problems. To avoid those
problems, fly the recommended approach speed accurately . If weather conditions and the particular
aircraft's operating instructions indicate that, in some
circumstances, a higher speed is desirable, then that
increased speed must be determined carefully. If you
believe it will be necessary to fly at a speed which is
considerably in excess of the recommended figure, then
perhaps you should consider going somewhere else.
Other options may also exist; for example, if you were
faced with an extreme crosswind and felt you were not
in a position to divert, then it may be possible to declare
an emergency and make a perfectly safe landing into
wind on a taxiway. Sound judgment and a careful
assessment of all factors would be necessary in
considering this sort of option •
Aviation Safety Digest 1281 21
�Index of articles ACCIDENT AND INCIDENT
INVESTIGATION
issues 1-128
H
Birds
ground attack on aircraft fabric 53-28
nests in aircraft 8 3- 21 99- 28 1 0 7-26 11 2-1 2 118- 14
strikes 2-9 34-24 38- 6 41 - 1149-571-1 87- 2 7 102- 28
104-12 109-13 120-18 128-16
strike reporting 11 2- 30 1 2 8-19
AIRCRAFT SYSTEMS
Chocks 1 0 5-9
Ground safety 24- 3
Costs of aircraft accidents 1 21-18
Incident reporting 27-10 3 2-15 109-16 113-13
immunity 24-1 5 4-1 100 -1 114-3 122-1 2
the Australian system 1 09-14
Licence suspension 3 7-22
Release of Information 117-3
Statistics 87-12 110-30 115-18
takeott 1 03- 6
Theory of prevention 1 02-10 128-3
AEROBATICS
Electrical 12-1 3 2-1 8 46-1 4 7 5- 8 98- 1 2 98-26 105- 18
105-19 105-20 1 23-1 7 1 2 7-1 0
Engine
controls 36-1 2
monitoring gauges 1 0 7-1 2
Flight recorder 110-9
Fuel
auxiliary fuel pumps 121-8
Cessna 200 fuel system malfunctions 114-20
leakage 38-5 7 9-1 6
mixture control technique 55-13 8 7-22 106-4 126-13
spark plug fouling 11 3- 22 127-22
specific gravity 11 2-28
systems 5 7-8 11 9-23 120-12
tank caps 27-4 37-14 109-18
tank vents 3 5-1 O 59-4 89-24 11 3-1 O
vapour lock 43-6 121- 8
Fire
brake and wheel 71-27 45-18
engine 9-18 18- 4 24-24 33-6 39-23 45-2 64- 16 83- 13
115- 14 1 16- 2 1 117- 21
hand portable fire extinguishers 1 24- 3
in flight 7- 5 9- 18 33- 14 64- 16
refuelling 1-7 18- 31 42- 24 45- 14 55- 9 63- 13 104-30
spontaneous combustion 119- 12
Fumes in cockpit 6 1-22 77-1
lnflight vibration 119-10
Insects
extermination hazards 83- 27
hazards 43-27
nests 16 -26 49-22 55-2 1 89-24 11 8-1 1
Mercy flights 5- 19 8- 17 17-1 3 25- 27
Jet
Monitoring 121.5 127- 23
blast and intake danger 15-2 19- 29 26-13 50-8 60-20
65-1 2 80-11 98-16
Runway
condition 5-21 6-2 1 8- 7 9- 9 20-24 23-21 8 5- 1 o 89- 13
foreign objects on 4 1-22 4 5- 25 50-7
lighting, VHF-activated 103- 19
visibility 3- 7
Taxiing 1-22 3- 24 58-5
T·vasis 41-5 11 4-1 3
Tie-down 11 0- 6 11 2-1 8
Wake turbulence 2- 16 21 - 6 25-7 3 1-20 51 -1 4 54- 25 63- 14
Life jackets 92- 25
Procedures 2-1 8 8 -1 4 28- 13 36- 20 36-23 4 1-12 56-1 2
57- 14 98- 12 123- 16
Propeller runaway 13- 1
Sarwatch 39- 8 50 - 13
Search and rescue 25-21 25- 28 36- 3 77-1 86- 21 91 - 20
101-28 102- 24 103- 22 104- 27 105-28 125-16
airborne Direction Finding 125-17
Structural damage 116- 12
Survival 18- 1 46-21 50-26 77- 6 116-1 5 117- 20
6 5-16 8 7-20 94- 28 95- 10 1 21 - 3
Gust locks 1 00-4
8-23 9-22 10-17 27-3 27-27 28-1 2 33- 9 3 4-1 9 40-4 4 7-5
75-12 76-12 78-6 81-10 87-6 92-2 102-19 104-26 117-6
Hydraulic 127-1 0
failure 14-24 3 2-6
fluid contamination 1 7-5
FLYING TECHNIQUES
EMERGENCIES
Landing gear 59-19 11 1- 14 11 5-1 O
Oil
AGRICULTURE
6-7 6-22 7- 22 7-2 7 8-5 9-7 9-23 9-24 10-17 10-19
11-2612-1 9 13-2616-2718-118-7 20- 17 27-1 0 20-18
20-25 21 - 27 24-8 28-14 28-24 30-7 3 0-8 30-16 3 1-26
31-27 33-23 38-1 41-14 4 2-12 44-14 44-19 4 8-4 50-14
56-26 59- 25 62-19 70-19 74-10 80-21 90-6 92- 27 94-26
Ag. strips 13 -25 13-27 58- 10 86-19 98-2 98-9 104-18
exhaustion 104-28
filter 32-19
on windscreen 45-5
shortage 44-9 46-26
system 56-24
Propeller 6-12 18-1O 43- 16
16-20 17-7 19-8 1 9-26 2 0-26 21 -24 23- 10 26-6 27- 6
31-8 36- 16 41 - 12 44-2 51-6 63-5 78- 1190-2093- 2
105-10 108-3 109-9 123- 10 125- 8 126- 6
Undercarriage indicator lights 59-15 102-1 8
Decompression 35- 16 37- 19
Circ uit entry 97-1 4 99- 8 108- 25 12 7-3 127-4
Warning systems 11 9-1 5
Ditching 5 -1 0 5-1 9 7-6 10- 12 16-20 29- 23 33- 6 36- 4
Fuel management 1- 23 3- 17 5- 10 6- 25 7- 6 8- 21 8 - 22
a
60-16 80-16 9 2-25
Door open in flight 3 2- 10 63- 21 76- 19 87- 8 100- 28 115- 7
118-22 1 23-22
AIRPORTS AND AERODROMES
Toxic pesticides 34-28 ..
Wire strikes 3 -26 7-23 8-25 8-2 7 9 -21 9-25 12-4 12-21
12-22 13-24 15-27 20-19 21-18 28-22 3 1-28 36-1
36-18 56-16 59-16 63-17 64-2 2 67-1 67-3 67-5 6 8-1 0
70-7 70-26 80-28 88-16 102-8 108-19 114-4 120-11
120-12 123-21
See also Specia l Ag. Issue 1985
Asymmetric flight 1-1 1 4 - 1 6- 17 7-1 0 8- 13 12- 1413-1 1
Airspeed 26-20
limitations in turbulence 21 - 1 4 3-20 116-24
manoeuvring speed 2 7- 3 31 - 1 107- 16
Va and aircraft weight 118- 7
Aerodromes
Authorised landing areas 5 8-17 6 4-14 6 7-1 67-1 0 97-22
Government, licensed, ALA 107-5
licensed 41-24
outback 5-6 53- 20 5 8-1 7 103-29
procedures 49-13
Aircraft security
general 102-1 6
theft of fuel 59-21 98-27 114-22
Animals 70-24 101 -24 103- 27 106-21
Emergency landings 3- 25 6-25 7- 5 7-10 8- 2 1 8-2 2 8- 26
10-2111-2511 -26 12- 18 14- 17 17- 26 18-23 21 - 22
22-8 23- 18 2 3- 25 24- 1 30-1 8 34- 8 36- 20 36- 24 37- 24
39-27 4 2-13 4 3-4 44- 2 45- 12 49 - 6 50-22 50- 26 52- 10
54-23 5 5-1 3 5 7-8 58- 13 59-1 59- 21 59- 22 65- 28 66- 4
6 7-7 70-1 70-16 71-17 71 - 22 74-1 4 76- 22 77-1 78- 11
78-18 7 8-24 82- 24 82-26 85- 9 86- 2 86-1 9 87- 2 88-12
89-1492-7 92-1192-1499- 1099-27103-20107-20
Propeller feathering 1 28-1 8
Emergency locator beacons 91 - 20 1 16- 17 125-19
Engine failure 1-23 2- 18 6 - 2 2 7-6 7-10 8- 14 10- 20 10- 21
11-23 11-25 12-12 12- 1413- 613- 1216- 2016- 26
18-30 1 9-26 26- 2 4 28 - 16 32- 12 36-4 36- 20 4 1-12 44-2
45-12 4 6-6 51-6 52-10 55-1 3 59-1 59- 4 69- 5 70- 16
71-22 74-1 4 76- 22 76- 23 80-28 89-14 91 - 3 92- 14
121-11 123 -1 0
Anti-collision lights 1 0 5-25
Evacuation 26-14 108- 23
Aquaplaning 29- 16 37-16 39-1 53- 14
21-12 36- 24 37- 9 37- 24 39- 27 40- 24 4 2-26 43- 4 46-18
50- 14 50- 26 55-2 57- 17 5 9 - 21 59- 22 6 7-7 7 1-17 8 1-24
86-2 87- 2 87-26 9 1-22 93- 16 103- 20 103-21 109-16
1 12-14112- 23115- 4124- 131 2 6- 131 27- 6127- 22
Landing
checks 99- 13 11 9- 9
expectancy 107-10
flap retraction 76- 14 111 - 23
ground effect 9- 3 11 1-3
ground loops 29- 26 63- 24 65- 6 74- 24 79- 27 96- 10
heavy landings 12- 17 14- 15 23- 4 25- 24 4 7-21 60- 16
63- 22 64- 26 8 9-20 122- 1 0
non-precision instrument approach 1 08-26
overrun 9- 9 17- 9 30- 4 101-2
soft-field operations 116- 18 1 18- 15
tailwheel aircraft and crosswind landings 122- 3
technique 6- 3 10- 3 14- 5 21 - 5 23- 21 25- 8 27- 6 28-26
29- 16 64- 1 79- 22 95- 19 97-10 99-5 104-22 1 11-23
117-5
transition from instrument to visual approach 126- 9
undershoots 3 - 15 5- 17 12-17 2 1-1 3 26- 16 43- 12 6 1-24
64-1 76- 2 78- 14 80-26 93-20 93- 24
unsuitable landing areas 42- 20 47- 26 50- 2 55-1 4 58- 6
58- 18 58- 20 61 - 20 65- 20 67- 19 70-1 70-11 78-18
93- 12 96- 21 100-24 103- 29 115- 3 1 23- 14
22 ! Aviation Safety Digest 128
Aviation Safety Digest 12 BI 23
�wheels-up landings 1-10 6-26 14-4 14-25 29- 1 2 39-27
50-27 51-2162-1066- 12 68-18 83-18 92-12 92-18
98- 28110-16 113-12
Loss of rudder control 17- 19 23-7 54-14
Vne 122-1 3
HUMAN FACTORS -
Wake turbulence 104-11 121 - 3
Weight and balance 25-17
Spin 1-22 3-20 5-23 10-22 10-23 14-21 16-28 19-18
26- 10 104-20
Chipmunk 22-1
Airmanship 48-14 67-1 4 78-28 79-14 102- 4 116- 5
117-13127-8
HUMAN FACTORS -
Stall 2-24 3-29 5-18 5-21 5- 25 6- 24 7- 25 8-23 9-22
11-23 14-2119-2020-121-1230-3 34-14 34-19 37-10
44- 10 45-12 47-2 48-10 56-8 84-26 88-9 92-2 92- 7
92-20 93-6 93-10 94-22 97-6 99-24 101 -1 8 121-6
PHYSIOLOGY
Airsickness 90-13
Taxiing 53-20 58-5
Alcohol 52-2 52-6 63- 1 77- 2085-2 127-1 8
Trim 15-5 32-22 46-1 48- 10 70-14 118-8
Caffeine 116- 19
Food poisoning 40- 22 5 1-1 1 104-1 O
Distraction 77- 28 83-1 3 83- 18 88- 2 94-6
Hearing conservation 11 8-12
headsets and warning horns 122- 7
turbine aircraft 37- 20
Exceeding authorisation limits 3- 29 5- 23 5- 25 6- 16 6- 24
6-25 8-23 8- 26 9- 22 9- 26 11 - 22 12- 4 13- 25 14- 26 15- 28
1 5-30 16-25 16- 26 25-14 28-1 35-22 36- 1 36-8 43- 8
47- 5 47-7 56-18 60- 4 66-1 68-10 74-8 74- 24 77- 20 78- 6
7 9- 6 79- 10 81-6 8 1-28 83-2 84- 16 96-4 97-2 11 5-17
126- 3
Drugs and medication 8- 6 48-27 58-16 63- 9' 63-19 85- 8
90-13
Ergonomics 1-5102- 18117-16
..
CJ
Dynamic rollover 126-18
Engine overspeeding 60- 10
Crew
crewmanship 5-3
division of responsibility 28- 26 30-1 8 95-19 110-28
114-17 11 9- 19 1 23-9
flight deck management 63-5 103- 8 109- 8 110-24 11 5- 16
liquids in the cockpit 6- 5 27-25
Fatigue 8-2 12-10 12- 22 17-22 19-6 20-1 8 26- 6 7 2-1 0
86-2 7 95- 19 123- 12 1 25- 5
Dehydration 11 0- 3
Diet 103-25
HELICOPTER
Navigation 5-19 1 2-15 18- 16 19- 12 21-10 26- 6 26- 19
27-1 1 31 - 13 32- 16 35- 1 39- 18 41 - 6 44- 20 47-26 55-2
55- 10 55- 16 66- 4 70- 1 72- 1 72- 18 72- 2 1 72- 28 78- 18
85-6 93- 12 97- 16 98-2 99- 18 102- 5 102- 13 110- 28
113-20
lanes of entry 113- 4 116- 23
Restricted areas, penetration of 1 11 - 27 117- 12 124- 20
Channelised attention 103- 28 107-1 9
Decision-making 31 - 22 116-1 1 124- 17
frustration 1 10- 29 1 24-1 6
IFR/VFR compromise 7- 15 9 -1 4 10- 16 17- 18 18- 20
18-28 20-1 0 23-12 30- 11 31 - 24 37- 1 41-8 42- 18
49- 16 54- 7 73- 13 73- 2 4 74-1 77- 17 78- 21 79- 18
80-2 81 - 2 8 1-6 82-1 0 82- 19 85- 9 89-2 94-2 95- 2
95- 6 96-1 4 100- 20 100- 23 100- 30 105-26 106- 7
109-26111-4113- 8114-23120- 16121 - 13 122-9
126- 20
programmed mind 5-24 6-27 7-26 10- 22 12- 15 14- 23
16- 14 16 -16 16-1 8 16-25 17-1 3 18- 20 37- 1 39- 4
40-20 41-16 49-1 52-14 55- 2 57- 18 57-27 60- 1 65-1
68-1 73- 2 73-8 73-17 75- 2 77-10 79- 2 82- 10 82-19
87-16 91 - 6 9 1- 16 99- 14 102-2 102- 9 103- 3 1 03- 25
104- 18 105-1 5 11 2- 23 119- 16 122- 9 127- 13
recognition of personal limitations 1 09- 30 11 6- 4
Carbon monoxide 23- 26 45-16 5 1-1 3 89-18 109-3 1 13-23
126-11
9-20 15-28 19-10 19-11 21-26 22-22 27-22 33-22 42-15
54-11 61-1 62-2 84- 2 84-6 8 4-1 0 84-14 84-21 84-26
90--2 101 -4 101-17101-19107-18107-19118-1 0124- 12
125-13 127-9
Low jet routes 1 01 -5
Complacency 94-6 123- 18
Takeoff 1-13 1-24 2-15 5-7 18-26 20-1 6 53- 18 61-12
71-1 85-10 88-9 90-10 90-1 6 91 - 11 92- 20 101-18 104- 6
104-16 105-7
GLIDING
PSYCHOLOGY
Heat stress 122- 20
High altitude flight 3 - 3
Hypotherm ia 123- 8
Oxygen
antidote to cockpit fumes 52-21 6 1-22
hypoxia 66-7 101-23 105-3
oxygen systems 18-6 41-21 11 2-1
General 47- 10
Pilot incapacitation 29-1 5 1-1 1 00-26 104- 20
Grass fires 48-17 50- 21 1 13- 7 1 26- 1 7
Scuba diving, flight after 28-7 43-11
•
INSTRUMENTS AND NAVAIDS
Altimeter 7- 3 14- 18 19-4 27- 14 45- 24 48- 18 65-14
65-23 74- 28 78-1 80- 22 8 7- 6 87- 28 94- 6
Autopilot 21 -1 4 70- 14 90- 26 11 8-13
Compass
error 31-22 44- 20 72- 2 1
interference 22- 20 27- 26 28- 23 55-20 69- 22 97-28
Deficiencies 28-1 1 31 - 6 34- 20 53-13 64- 27 98-24 118-1 3
ILS 9- 6 22-1 0
Interference with controls 54- 2 58- 13 69-1 6 89- 13 99- 27
100- 4 102- 18 103-28 104-17
Monitoring instruments 24- 13 54- 18 127- 6
Navaids 33- 27 87- 26 109- 2 1
Radar 24- 6 40- 5
Radio compass 23- 1
Strobe lights and ELBs 115- 7
Stress 115-6 1 19- 17 120-14
Supervision and self-<liscipline 121 - 12
tl
MAINTENANCE AND SERVICING
INFLIGHT OPERATIONS
Bogus aircraft parts 17- 1
Ground resonance 125- 20
Hughes 500 fuel tank vent fairing 111-20
Sensory illusions 2- 5 3-9 7-8 16- 1 20- 21 35-6 37-25 75-2
75-1 8 96-1 4
Ice 30-10
Skill fatigue 121-20
Air pollution 1 22-11
Loss of directional control 128-4
Vision
blind spot 1 06-3
dusk 70-19
eye protection 1 O1-1 1
night vision 108-24
photochromic lenses 95- 29
polarised glass 1 09- 23
sunglare 6-25 9-23 17- 21 58- 27 59- 25 98- 8 107- 3
wirestrikes 123-21
Air Traffic Control 8 - 7 20- 14 27- 18 34-1 57- 14 77- 17
85- 6
Controlled airspace 28- 3 31 - 13 34- 1 46-4 69- 22
penetrations 19-1 2 28-3 46- 4 69- 22
Corrosion 86- 8 1 09- 20
Visual illusions 37-25 48-1 8 67- 24 78-1 78- 14 93- 20 103- 8
11 0- 24111 -1 0
Flight Service 8- 7 85- 6 10 1- 22
Defect diagnosis 23- 22
Loss of separation 19- 3 35- 1 6 1-1 0 94- 28 102- 14
collision 5-16 7- 24 7-27 1 1- 13 20- 6 25- 20 27- 18 28-4
33-1 0 62-6 74-18 75- 28 77- 26 98- 5 101-8 103-27
11 9 - 3
near miss 7 4- 18 75-28 77- 28 108- 25 1 15-13
Engin es
control maintenance 36- 12 54-23
mounting failure 62- 16
Maintenance 1 09- 22
Mast-bumping 11 5-20
Overpitching 5 1-9
Power-settling 68-20
Rollover 9 1-25
Safety 82- 16
Slung loads 122- 6
Ta il rotor failure 69- 8 86-16
24 I A viati9n Safety Digest 128
Communications 19-3 19- 15 32-1 35- 8 38- 28 40- 26
42- 28 47-19 47-28 49-1 3 52- 13 5 7- 14 68- 22
loss of 22- 7 45-1 3 46-28 103- 30 109- 18
Brakes 11 - 27 45-18 7 1-27 91 - 28
excessive wear on dirt strips 111 - 9
failure 85- 10 88-14
reverse thrust 31 - 7
Cessna 310 fuel selector 1 28- 1 4
Control cables
crossed 6-8 8- 21 20- 5 59- 27 107- 30
inspections 29- 24 107- 15
rudder controls 1 7-19 23- 17 54- 14
splices 101-13
Fabric separation 30-23
Aviation Safety Digest 12 BI 25
�Flexible hose installations 56-24
~ METEOROLOGY
NIGHT VMC
SPECIAL OPERATIONS
Foreign objects 14-10 23-1127-1241-22 45-25 50-7
61-6 62-18 68-24 76-21 92-28 104-25
Fuel tank caps 27-4
Glued structures 32-20 35-18
Ground handling procedures 126-22
Heavy landings 4 7-20 60-16 63-22 122-1 O
Hydraulic fluid contamination 17-5
Hydraulic pressure failure 14-24
Ignition switch, misaligned 53-26
Inadvertent undercarriage retraction 23-23 1O1 - 1O
Landing gear 33-15 39-7 49-18 60-22 69-12 112-13
Maintenance error 5-11 15-24 17-19 17-26 18-19 22-8
22-16 23-14 26-24 28-6 33-16 33-24 34-10 36-11 38-26
42-1146-2647-22 48-7 70-22 92-27 100-15120-21
Maintenance release 115-8
Metal fatigue 2-20 15-7 57-10
Modifications 32-22 62-19 126-1 o
Oleo leg 47-16
Pitot
blockage 66-9 75-23
covers 49-14 52-1 6
Permissible unserviceabilities schedule 31-16
Propellers 1- 22 2-1 4 6-1 2 9-1115-2417- 918-10 26-9
33-20 35-26 69-1 72-24 11 7- 22
fatigue failure 27-1 99-21
shock loading 67- 22
Recording procedures 33- 16 65- 26
Spark plug fouling 11 3-22 127-22
Stop nuts 56-1 7 65-11
Structural
damage 49-16 54-21 65-12 76-12 77-17 88- 24 90- 28
failure 2-20 5-2 5 9-20 11-1 6 14-1 5 15-28 21 -1 21-6
23- 4 24- 4 25-24 27- 3 28-1 2 31-1 33-22 34-24 35-18
43-20 46-12 51-20 57-10 59-10 68-5 81-10 82-2
8 3-1 3 86-8 90- 2 94- 2 107-1 6
.
limits 30-3 38-1 46-1 2 76-12 90-2
loose parts 46-11 5 9-20 78-1 1
Throttle-control failure 56-17 105-16 11 2- 9
Turbo-charger failure 103-30
Tyres 23-1 7 49- 2 1 11 8-23
Density altitude 33-1 11 0-1 8
Banner towing 39- 17
72-1 72-10 94-26 102-13 114- 15 120-8
Dust devils 101 -20
Beach operations 107- 8
Dust storms 122-16
Outback 5- 6 46- 21 53- 20 55- 2 55- 10 55-supplement
58-14 72-28 77- 6 97- 16 97- 20 98-14
Fog 40-20 41-2 61-24 76-2 100-20 107-28
. . PARACHUTING
Forecasts, interpretation 106-26 109-24 119-21 126-7
Papua New Guinea 3-22 7- 26 2 1-20 43- 1 45-1 1 66- 16
7 1-10 100- 7 100- 13
Frost 62-20 102-27 106-10
Tiger Moth 3 - 20 81 - 14 83- 1 7
Hail 31-18 49-10
Ice 25-4
airframe 14-1 19-20 23-18 25-3 40-6 57-16 61-25
62-20 85-24 92-23
carburettor 25- 18 35-21 45-20 50-22 55-20 59-25 61-26
85-18 103-31 106-28 108-14 112-24 12 1-16
engine 28-16
fuel 109-25
pilot/static 39-24 99-24
48-156-1369-14 70-11101 - 14 116- 27125- 7
TRAINING
PREFLIGHT PREPARATION
Lightning 39-10 40-12 62-22 66-24
24- 20 56- 5 76- 26 128-10
Meteors 46-8
Mountain wave effect 3-22 5-22 21 - 25 30- 17 42- 6 57-10
57-22 88-27 94-14
Aircraft familiarisation 29-1 1 59- 15 62- 28 70-1 6
Students 64- 26 65-8 9 1-3 91 - 8 106-3
Cargo restraint 6-23 11 -2 1 23-8 80-6 1O1-7 113-1 3
Solitary waves and low altitude wind shear in Australia 99-2
123-3
Temperature and humidity: effects on wing lift and engine power
11 -7
Thunderstorms 11 - 3 3 1- 14 52-22 59- 10 60- 6 68-5 82-2
82-22 94-10 104-3 108-8 11 3-21
Tornadoes 54- 26
Wind
shear 6- 9 14-13 30- 12 31 -1 4 34-12 98-20 103-8
106-14 106-22 110 - 24
speed , assessment 11 8- 20
See also Decision-making in HUMAN FACTORS - PSYCHOLOGY
ULTRALIGHTS
Flight planning 3- 25 12-18 18-28 19- 6 2 1-1O 22- 1 5 28- 8
28-20 42- 5 49-13 55-1 4 55-supplement 59- 8 69- 27 70- 1
78-18 82- 6 88- 22 89-8 97-20 99-10 102- 2 105- 8 109- 19
111-28 120- 16 1 25-3
Passenger briefing 110 - 29
Turbulence
clear air 13-1 0 67-1 2 93- 2 4
low level 109-1 O
E:I
Dangerous cargo 14-8 16-1 1 21 - 21 22- 23 26- 27 37- 13
50-19 52-2 1 66-10 89-28 101 - 26 115- 23 120- 3 126- 4
127-12
23-25 1 19 -1 3 124- 6 126- 5
Performance 11-7 33- 1 37- 4 42- 1 50-16 58-1 64-1 0 67- 16
83-6 1 10-18 11 2-11 117-1 0
P-charts 118- 16 120- 6 123- 20
Preflight checks 26-26 28-21 34- 6 38- 24 42-1 4 42- 19
42-26 46- 26 60-14 65-28 66- 9 66- 12 69-25 86- 17 93- 16
96-196- 2998- 27 103- 6 107- 7 109- 6 11 2-14 120- 22
121 -1 9 122-18
brakes 5-21 103- 26
control locks 62-14 68- 27 90-16 110- 21
fuel 13-1 1 18- 9 32- 24 43- 27 44- 9 50-24 54- 22 67-7
87-26 90- 27 109- 28 11 5- 15 117-1 9 120-12 125-1 8
128-15
contamination 12-1 9 14-17 24-18 26- 22 30- 16 35- 14
45- 8 45-27 46-6 64-9 64-28 65-7 .74- 14 91- 3 108- 13
MUSTERING
Welded pipe lines 33-5
Propeller safety 35- 20 40-3 40- 10 45-6 56- 14 65- 24 76-1 6
83- 11 89- 23 9 1-14 96-23 96- 26 103-1 2 124-1 8
Refuelling 1-7 18 - 3 1 35-14 42-24 45-14 55- 9 63- 13
104-30 125-1 4 126-12
fuel conversion charts 125-12
Wooden structures 1 9-1
93- 6 93-1 0 101-25 1 17- 18 118-3 123-13
· Safety harness 26-1 34-11 36-27 99-9 103- 4 104- 26 108- 6
11" 1-81 14- 22 1 19- 7
Seats 62-1 4 96- 28 111-26 1 12-26 123- 19
Weight and balance 5- 18 7- 26 8- 24.10- 9 14- 26 ·1 8-23
19- 24 3 1- 12 35- 5 56-182-686- 12 103-14 104- 81 16- 3
Windscreen 3- 31 45-26 57-16 74-21 9 7-29
26 I Aviation Safety Digest 12 B
A viation Safety Digest 1 2 BI 27
�
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Aviation Safety Digest
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Aviation Safety Digest, number 128 (Autumn, 1986)
Identifier
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128
Date
A point or period of time associated with an event in the lifecycle of the resource
1986
-
https://collections.heritageoftheair.org.au/files/original/c68fd404e5850159ea628f2e2296c49e
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PDF Text
Text
ASD 127
SUMMER1985
�l
Contents
3
Dangerous circuit entry
An Inexperienced pilot failed to broadcast his Intentions and to
maintain an adequate lookout on returning to the circuit. Aa he
reached mid-final approach another aircraft took off toward him.
4
How are your circuit entries?
6
POL maintenance
POL stands tor Petroleum-Oil-Lubricants. Attention to
contents and indications is required both on the ground and
in the air.
8
Alertness and communication
Numerous potential accidents have been averted through the
timely action of apparently uninvolved Individuals, ranging
from engineers and pilots to casual observers.
9
Currency and aircraft knowledge
A glider was destroyed after the pilot mistakenly operated the
alrbrake lever Instead of the trim control.
10 Sy4Jtems knowledge
Only by knowing his aircraft and its systems thoroughly can
a pilot develop the confidence to operate that aircraft safely
to Its full capabilities.
12 An explosive combination
An oxygen bottle shipped by air was found to be packed In
material contaminated with synthetic oil: had the cylinder
leaked the result could have been an intlight explosion.
13 In brief
Items from Australia and overseas.
16 Just as the gun Is always loaded .•.
During a compression check of a C 172 the engine fired and the
aircraft ran into a drainage ditch.
17 A timely diversion (reader contribution)
The pilot of a Bonanza carrying five passengers elected to
land on an ALA when the clouds started to close in.
18 The residual effects of alcohol
The untoward effects of alcohol lest very much longer than
most of us appreciate.
22 Spark plug fouling
This problem remains fairly common to GA aircraft.
23 Monitoring 121.5
lnflight monitoring of the distress frequency. 1 21 .5 MHz, Is
a practice recommended to all pilots.
Covers
Featured on the cover is the first Piper Mojave imported into Australia
by Pacific Aviation. The Mojave still had its American markings when
this photograph was taken, but is now listed on the Australian Register.
The photographer was Mr Ron Israel of Sydney, who used a Pentax
6x7 cm, 105 mm lens. Fujicolour.
A contrast provided by the 1930 photograph of the Southern
Sun over the Incomplete Harbour Bridge on the back cover.
2 I Aviation Safety Digest 127
Dangerous circuit entry
Aviation Safety Digest Is prepared by the Bureau of Air Safety
Investigation In pursuance of Regulation 283 of the Air Navigation
Regulations and Is published by the Austral/an Govemment
Publishing Service. It Is distributed free of charge to Australian
licence holders (except student pilots), registered aircraft owners and
certain other persons and organisations having an operational Interest
In Australian clv# av/atlf>n.
Unless otherwise noted, artlcles In the pubHcatlon are based on
Australian accidents or Incidents.
Readers on the free list experiencing problema with distribution or
wishing to notify a change of address should wttte to:
The Publications Distribution Officer
Department of Aviation
P.O. Box 1839Q, Melboume, Vic. 3001
Aviation Safety Digest Is also available on subscription from the
Austral/an Government Publishing Service. Inquiries and notifications
of change of address should be directed to:
Mall Order Sales
Australian Government Publ/sh/ng Service
G.P.O. Box 84, Canberra, A.C. T. 2601
Subscriptions may also be lodged at AGPS Bookshops In the capttal
cities.
Reader contributions and correspondence on articles should be
addressed to:
The Director
Bureau of Air Safety Investigation
P.O. Box 367
Canberra City, A.C. T. 2601
©Commonwealth of Australia 1985
ISSN 0045-1207
R84 403(2) cat. No. 85 1331 6
Printed by Flnepress Offset Printing Pty Ltd, 49 Railway St..
Yennora, N.S.W. 2161
The holder of a Restricted Private Pilot Licence with
about 120 hours total flight time had arranged to take
three friends on a short sight-seeing trip in a Cessna
172. As he had not flown before with the organisation
from which he was hiring the aircraft - and in fact had
not flown a Cl 72 for about eight years- the
organisation's CF! first required him to undertake a
dual check. This consisted of a circuit and landing; the
pilot was assessed as proficient and was authorised to
hire the Cessna.
Following the check the passengers boarded the
aircraft. As the aerodrome was uncontrolled the pilot
made an 'all stations' call on the area VHF frequency
before taxiing. He estimated that .the wind was coming
from the west at 5 knots, which meant that it was
blowing directly across the runway, 16/ 34. A normal
takeoff was made from runway 16.
The aircraft was flown in the local training area for
about 70 minutes , and then returned to the aerodrome
with the intention of carrying out a fullstop landing. As
the pilot considered the wind conditions to be
unchanged since departure , he joined the circuit on
crosswind for 16. He did not make an inbound 'all
stations' call. No other circuit traffic was sighted
and after a normal circuit the Cl 72 was positioned on
final appoach for 16 at about 70 knots with full
flap extended.
In fact a Beech C23 Sundowner and a Cessna 182
were carrying out circuits at the time - on runway 34.
As the Cl 72 reached about mid-final approach for 16
the Beech was just becoming airborne from a touchand-go. The pilot-in -command of the Beech , who was
a n instructor, saw the Cl 72 and immediately in itiated
a turn to the right to make way. He also transmitted a
call to the Cessna pilot , telling him what he was doing
a nd that he would remain clear.
T he Cl 72 pilot later stated that he saw an a ircraft
take off towards him and then turn right. He a lso
heard the radio transmission but could not
understand it.
Given the circumstances, he decided to go around
a nd carry out another circuit. He said that he appli ed
full power and commenced a gentle right turn . Then ,
at a he ight of about 40 feet , he fully retracted the flaps
in one selection.
T he Cessna descended rapidly until it impacted with
the grass surface between the runway and the parallel
taxiway. Impact was made in a slig htly left wing down ,
level a ttitude at a relatively low forwa rd a irspeed . The
aircraft skidded for about 30 metres before coming to
rest in verted . The fo ur occupants escaped unaided
th rough the r ight side window.
eight years, he had neither the familiarity with his
aircraft nor the broad overa ll experience to fall back
on when the situation started to become difficult.
His problems began when he returned to the circuit
and, by failing both to broadcast his intentions and
maintain an adequate lookout, did not determine that
other aircraft were now operating. Given the light
wind, it should have been quite clear to the Cl 72 pilot
that if other aircraft were in the circuit, either runway
could have been active. As it was, his lookout was poor
and he did not see the Sundowner until it had become
airborne and was turning right.
The actions taken by the Sundowner's pilot would
have permitted the Cl 72 to have completed the landing
on runway 16 safely. However, the Cessna pilot decided
to go around , in the course of which his faulty flap
retraction technique then completed the c hain of events
contributing to this accident.
The Cessna 172 Pilots Operating Handbook states
that for a go·around , wing flaps should initially be
retracted to 20°. Once airspeed has been increased to a
safe climb figure , the remaining section of flaps should
then be retracted slowly. In this case, the retraction of
flaps fully in one movement , at a low speed and height ,
caused a rapid loss of lift a nd precipitated the crash.
Postscript
The accompanying photog raph is of the window
through which the pilot and his passengers escaped .
Note the heavy tie -down sta ke and c hain lyi ng loose on
the a ircraft's roof. There is little doubt that in less
fortunate circumstances this dange rous , unsecured
object could have inflicted fatal injuries when the
aircraft struck the ground •
Analysis
At the tim e o f the accident the weather was CAVOK,
with a temperature of + 25 °C and a wind of 250/ 05.
The p ilot's inexperie nce was considered to be a
rel evant facto r in this occurrence . Wi th onl y 120 hours
tota l fligh t time, and not ha ving flown a Cessn a 172 fo r
Aviation Safety Digest 127I 3
��POL maintenance
The acronym POL stands for Petroleum-Oil-Lubricants and is a generic term for those essential fluids we
put in our aircraft. POL can, however, do more for us than providing fuel and lubrication for engines. A pilot
who carefully monitors the way or rate in which a particular aircraft burns POL may, by detecting changes
in the amounts being used, get an early warning of a potential mechanical problem.
Periodic maintenance inspections are intended to ensure
continuing airworthiness and trouble-free flight, and in
most cases they do. Nevertheless, mechanical failure can
still occur since it is not possible to forsee all of the
various circumstances which could interfere with the
normal operation of an engine, a propeller or structural
members (regrettably, operation outside the
manufacturer's limit is one factor which emerges
regularly in this context).
There can also be potential problems which escape a
pilot's notice, even during a careful preflight inspection,
because they are not apparent under static conditions.
The pilot who rarely, if ever, has a maintenancerelated accident is most likely to be the one who is quz'ck
to notice any subtle change in his aircraft's performance.
Aircraft, like people, are pretty much creatures of habit;
and their behaviour is quantifiably measurable. A given
power setting in a given takeoff configuration should
resu lt in specific takeoff performance (acceleration time,
runway distance used, and so on). Similarly, predictable
performance parameters should also be achieved during
the cruise, approach and landing.
Because specific performance figures should be
achieved, slight, sometimes very subtle changes in the
expected numbers, are often clues that something odd is
going on, some kind of trouble is brewing. Good
operational maintenance consists of paying attention to
such changes while flying the aeroplane, analysing them
- and then if necessary doing something about them in
time.
Monitoring POL
Flight instruments and engine gauges are not the only
measuring devices in an aircraft. A sharply increasing
rate of fuel consumption, for example, should not be
dismissed as simply an indication of advancing wear.
High fuel usage could mean that an engine is suffering
from loss of compression, burnt valves, bad plugs or
points, worn magnetos, a fuel system leak, and so on.
Whatever the cause may be, as long as the symptoms
are recognised, the aircraft can be checked out before
engine problems arise on a dark night during an
instrument approach.
Just like pain in the human body, substandard
mechanical performance in an aircraft is a sign that
something is wrong and requires attention . In order to
be tuned in to what is going on with the various systems
of an aircraft it helps to keep records. (You do not need
to be a LAM E to do this.) It seems inconsistent that some
owners are very concerned about the price of the fuel
they buy , yet cannot be bothered to chart fuel
consumption rates. There are instances on record of
excessive consumption rates, which were not recognised
by the pilot, resulting in inflight emergencies. Some
6 I Aviation Safety Digest 1 2 7
occurrences have been caused by t hings as simple as an
ill-fitting fuel cap. Whatever the cause, the imperative is
to recognise the symptom and take remedial action in
time.
As another example, some pilots may think that the
amount of lubricating oil an engine uses may be of little
consequence as long as the engine gauges stay in the
green: oil is relatively cheap and can easily be topped up
by any pilot, so what difference does it make if you have
to add two quarts instead of one every thousand miles?
The difference can be important. Although aircraft
engines have a relatively large oil reservoir - typically
about 8- 10 quarts for a piston-driven single-engine
aircraft - the normal usage rate established by the
manufacturer may be as low as \I.I pint per hour of
operation. (Acceptable usage rates can be found in the
manufacturer's operating or maintenance instructions.)
Oil is the only internal source of cooling for aircraft
engines, and any decrease in the quantity present means
a corresponding increase in the engine temperature.
Oil can be lost or simply 'missing' for a number of
reasons. Worn components, such as bearings or valves,
can cause problems. Another common cause is that of
not replacing the oil filler cap after maintenance or
topping up the reservoir. There are also recorded
incidents of sumps not being refilled after an oil
change.
An occurrence of the latter kind happened to the
owner of a Cessna I 72 which had just been given an
engine overhaul and a new paint job. As a last step in
the engine maintenance the mechanic drained the oil,
replaced the filter and was about to add oil when he was
called away by a long distance telephone call. He asked
his partner to add the oil. The partner agreed and
headed off in the direction of the Skyhawk.
An hour later the owner came by, found his 'like new'
aircraft parked out on the ramp , and decided to take it
for a quick trial flight. He performed a preflight
inspection, somewhat perfunctorily in view of the fading
daylight and the fact that the aeroplane was fresh out of
the shop, and took off. The engine ran like a charm for
about 3 seconds after liftoff - then in rapid su ccession
ran roughly and seized up . Fortunately the pilot
managed to get the 172 back on the ground without
further damage.
There was no oil in the engine. The initial fault was
the mechanic's, but the pilot also had not checked the
contents level during his preflight inspection.
Even though the pilot and the mechanic had both
committed fundamental inspection errors, opportunities
still existed for their omissions to have been detected
before the Cessna took off. For example, it appears that
in his eagerness to get airborne the pilot had not
confirmed that his oil pressure gauge was indicating 'in
the green' within 30 seconds of start up. A second
opportunity to detect the maintenance omission must
also have been missed during the engine run-up: given
the lack of oil in the system, the oil temperature gauge
should have been indicating a serious overheat by that
stage. (A cylinder head temperature gauge, if fitted ,
would have given an even earlier warning of engine
overheating.) Finally, good airmanship dictates a final
before-take-off scan of the engine instruments as takeoff
power is applied, so that the pilot has time to abort if
abnormalities are noticed.
Typical problems
A review of Australian accidents and incidents
attributable to the kind of problems discussed in this
article revealed the following typical factors:
• A pilot reported that he had been unable to reduce
engine rpm with the propeller control. Inspection
showed that a low oil level had caused damage to the
engine with a resultant drop in oil pressure. The pilot
did not know the correct oil level required in the
engine.
• On its first flight after a major inspection a Cl 72
experienced a complete loss of engine power.
Improperly installed fil ters and screens had allowed
all oil to escape after 15 minutes of flight.
• One engine of a Rockwell 690 had to be shut down
during a charter flight when it began to run roughly .
The pilot had knowingly accepted the aircraft with
an inoperative oil pressure gauge and was not aware
that a serious oil leak existed.
• When a P A34 pilot failed to secure one engine's oil
filler cap during his preflight inspection , the cap
came loose in flight , oil was lost, and an engine
shutdown became necessary.
lnflight
The green arc of an oil tempera ture gauge is fairly small
but is adequate for a pilot to detect a change in the
position of the needle in flight. A normal reading is not
necessarily dead centre since the operating temperatures
of engines vary. What is significant is:
• a higher than normal reading;
• a progressively increasing reading on the temperature
needle; or
• an absence of pressure when the engine is operating.
Oil temperature and pressure gauges are often small
and relatively inconspicuous instruments. Because their
readings almost always are steady and normal, a
tendency can develop not to include them in the
instrument scan as often as is desirable. But they provide
the key insight we have into the core of an engine , and
we cannot afford to ignore them if we wish the propeller
to keep turning. If you are scanning your gauges
regularly in flight you might notice the temperature
gauge climb into the red and the pressure reading zero
as the oil dissipates, perhaps in time to divert to the
nearest landing area; but if your first indication of
trouble is the sound of a rough-running engine, the time
remaining before your powered aeroplane becomes a
glider is likely to be very short.
Summary
A little bit of careful monitoring of POL usage rates can
go a long way both in terms of understanding an
aircraft and accident prevention. Attention to contents
and indications is required on the ground during
inspection, and in the air; while a few minutes spent on
a post-flight assessment of consumption rates can be
handsomely repaid •
Aviation Safety Digest 1 2 7I 7
�Alertness and communication
Currency and aircraft knowledge
Photograph courtesy of Mr Colin Addis
Aviation is characterised by the high degree of cooperation and good spirit among those who are
involved in it, either as a job or for recreation. Perhaps
more than most activities, it enjoys an ethos of mutual
help. The importance of this was graphically illustrated
in an account of two incidents recently published in the
U.S. magazine Flight Safety Digest. As that magazine
stated, the alertness and prompt communications of
two otherwise-uninvolved flight crews prevented
possibly tragic accidents.
The incidents
Both of the incidents are reported in the words of the
flight crews involved.
• 'Our wide body aircr aft was moving onto the active
runway for takeoff when the crew of another aircraft
informed us that we J:iad two spoilers on our left wing
in the FULL UP position. We cancelled the takeoff and
returned to the tarmac for a mainten ance inspection.
'Two spoilers on the left wing were jammed in the
FUL L UP position and would not return to the normal
position. Cycling controls, switches and the systems did
not help ... There is no cockpit indication of
this system .
'The follow-up from maintenance was that the
control rods from the spoiler mixer were dry and
needed lubrication.
'Recommendation: Pre-flight inspections should
include an inspection of the top of both wings to ensure
the spoilers are flush .'
• 'A wide body air carrier was on final approach and
8 I A viatlon Safety Digest 127
cleared to land on runway 25R. A small aircraft had
been cleared to land on runway 24R but mistook his
runway in restricted visibility and headed for 25R. The
runways are 6000 feet apart, and the respective tower
frequen~ies are not common.
'The small aircraft was b elow and slightly ahead of
the wide body- both headed for the same runway. As
it looked like a collision might occur, the crew of
another air carrier parked at the end of the taxiway for
25R broadcast a warning on tower freq uency.
No reply.
'They then broadcast for the wide body to take it
around - as the small aircraft had just landed ahead of
it. At about 100 feet AGL, the wide body went around.
'The tower was unaware of the incident until they
saw the small aircraft on the ground and the wide body
going around. There was no question in the mind of
the parked aircraft's crew that, had the wide body
landed, it would have demolished the small aircraft.'
Comment
These incidents contain a host of important lessons.
None is more significant than that of the incalculable
value of vigilance and effective communication.
Numerous potential accidents have been averted
through the timely action of apparently uninvolved
individuals, ranging from engineers and pilots to casual
observers with no aviation background. We all have a
role to play in aviation safety at all times. One day, we
may be in the aircraft at risk •
A glider pilot with about 60 hours total flight time
was planning to make an aerotow launch in a
Schneider ES 60. He had half an hour's previous
experience on the ES 60 and had not flown it for
three months. Whereas every other glider type the
pilot had flown had the trim control on the right
hand side of t he cockpit, the ES 60's was on the left
side, adjacent to the airbrake control. T he airbrake
and trim controls were of different shapes to facilitate
distinguishing between them.
Conditions were fine when the aerotow was made
in mid-afternoon, with good thermal activity reported
up to at least 4500 feet. T he tow rope was released at
2000 feet AGL and the glider pilot completed a turn
to the right. He was disturbed to note that, although
at gliding speed, the Schneider was sustaining a sink
rate of about 10 knots. In an attempt to redress this
he headed for a pine forest over which he expected to
encoun ter b est thermal activity.
En route to the forest the glider overflew the
aerodrome, from which observers noticed that the
airbrakes were fully open. Although the Schneider
was fitted with a radio the club base station was not
in use so communication was not possible .
When the sink rate did not reduce over the pine
forest the pilot decided to head back to the
aerodrome. At this stage his aircraft was at a height
of about 900 feet AGL.
It soon became evident to the pilot that he would
not even reach th e aerodrome, so he selected an open
paddock and began to set himself up for an
outlanding.
A right turn was made to position the aircraft to
land downwind in the paddock but shortly after the
pilot rolled out of this turn the glider struck one of
several tall pines on the edge of the paddock.
The ES 60 continued to descend and struck the
ground heavily before cartwheeling for some distance.
It was destroyed and the pilot seriously injured.
Analysis
Determining the reason for the glider's excessive sink
rate was straightforward. It appears that as the
glider's airspeed was reduced after the tow rope was
released , the pilot attempted to apply 'nose-up' trim :
instead, he mistakenly operated the adjacent airbrake
control, extended those brakes, and began to go
down instead of up.
There was, of course, more to the accident than
that one factor. Other significant points were noted
d uring the investigation and related to:
• the pilot's general inexperience;
• his inexperience on type;
• the proximity of the trim and airbrake controls;
and
• the pilot's failure to analyse the glider's
performance loss, and to identify the characteristic
airframe buffet associated with extended airbrakes.
Summary
Essentially this accident revolves around currency and
knowing one's aircraft. These are matters which no
aviator can ignore : they demand the serious attention
of all pilots, supervisors, training establishments and
those responsible for determining standards •
2--
..
Rear of cockpit. Note trim knob (1) and airbrake lever (2). Airbrake on right wing (3) has been pushed in by contact with fuselage
after landing.
Aviation Safety Digest 12 7I 9
�A Cessna 210-N with five people on board took off in
the mid-afternoon on what was to be the final leg of a
two day trip. Throughout the trip the pilot had noticed
that undercarriage retractions were taking about twice as
long as usual. Notwithstanding that, the gear did retract
following the final takeoff and the gear UP light
illuminated.
About 30 minutes la ter, with the Cessna established in
the cruise at 7500 feet, the pilot noticed that the
autopilot had tripped and that a high b attery discharge
rate was indicated. Also, the digital numbers on the
radio had gone very dim.
On checking the electrical panel the pilot observed
that the alternator had dropped off line and the gear
pump circuit breaker had popped. He reset both
services. Initially a high charge rate was indicated,
signifying a low charge level for the b attery.
A short time later the gear pump circuit breaker
popped again. The pilot reset it for a second time and,
to test the system, cycled the undercarriage selector
switch. T he circuit breaker remained 'in'. However,
coincident with the action of the cycling gear, an
unusual noise commenced. Not able to recognise the
noise, the pilot concluded that it was originating from
the engine.
At this stage, the pilot's problems started to mount. A
pungent odour became noticeable in the cockpit and
smoke appeared from the centre console area. The pilot
turned off some of the non-essential electrics but the
smoke became thicker. Then a substance which seemed
to be either oil or molten plastic became visible,
dripping on to the fuel selector. Deciding that he had an
engine fire the pilot transmitted a Mayday call.
All electrics except the master switch were turned off
and a descent commenced with gear and full flap down.
The gear had been selected normally (i.e. not using the
emergency lowering method), and while the pilot did
not see the green gear DOWN light illuminated, a visual
check outside indicated that at least the two mainwheels
appeared safely down.
What looked like a short, disused airstrip was n oticed
almost directly below, so the pilot decided to land there.
Because his assessment was that the strip was too short
and therefore an overrun was likely, he elected to land
with a tailwind, approaching over the top of timber,
stockyards and creek, to avoid the possibility of colliding
with those obstacles at the end of the landing roll.
Just before landing .t he pilot turned off the master
switch. T he smoke stopped immediately. At the same
time he shut down the engine by pulling the mixture
control to idle cutoff.
Touchdown was made at about 60 knots, 270 metres
into the strip (which subsequently was measured as 416
metres long). H eavy braking was applied but the aircraft
overran the strip, the last 100 metres of which had a
slight down-slope. T he pilot was aware that the chosen
landing direction was towards a shallow gully and ,
concerned that the Cessna might overturn if it entered
the gully, decided to stop the aircraft by deliberately
hitting a tree. Still travelling at some 40 knots, he struck
an 8 metre gum tree with the left wing.
The 210 slewed to the left and broadsided to a halt
10 I Aviation Safety Digest 12 7
130 metres beyond the strip. AVGAS from the ruptured
fuel tank in the wing showered over the aircraft's
occupants, but fortunately there was no fire. The pilot
and passengers rapidly evacuated the wreckage.
Some minutes after the crash the pilot activated an
ELT. When search aircraft arrived in the area he turned
on the Cessna's m aster switch so that he could use the
VHF radio.
The systems
Although the pilot had noticed after each takeoff that
the gear retraction time was abnormally long, he did not
investigate the reasons, nor did he ask any maintenance
organisation to check the system.
A brief description of the C210-N's hydraulic system is
necessary here. Hydraulic power is supplied by an
electrically driven power pack located behind the control
pedestal in the cockpit. The power pack's only function
is to supply hydraulic power for operatioii. of the
retractable landing gear. This is achieved by applying
hydraulic pressure to actuator cylinders which extend or
retract the gear and operate the gear down locks. The
hydraulic system normally operates at 1000 psi to 1500
psi and is protected by relief valves which prevent high
pressure damage to the pump and other components in
the system. The electrical portion of the power pack is
protected by a 35-amp 'pull-off type circuit breaker
(the 'gear pump circuit breaker' referred to above in
the accident summary).
T he significant aspect of this in relation to the
accident is that the electric motor-driven hydraulic
pump in the power pack is only intended to operate for
the very short periods wh en the undercarriage is being
lowered or raised: at all other times it should
automatically cut out. As the pilots operating h andbook
advises, excessive running of the hydraulic pump may
damage the power pack because of overheating.
As it happens, a post-accident stripdown of the system
revealed that a leaking seal had allowed oil to get into
the electric motor, causing internal damage. This
damage eventually prevented the power pack from
reaching the 1500 psi cutout pressure.
It seems that when the gear selector switch was moved
to UP after takeoff the undercarriage retracted
satisfactorily. However, because of the internal damage
to the electric motor, at either that time or shortly
afterwards when the pilot recycled the undercarriage
and started resetting the gear pump circuit breaker, the
electric motor did not cut out. T he hydraulic pump
therefore began to operate continuously, which explains
the unusual noise the pilot heard and mistakenly
ascribed to an engine abnormality. Additionally, because
the hydraulic pump was operating continuously it placed
an excessive d emand on the alternator, eventually
exceeding its capacity, which explains the popped circuit
breaker and the low battery charge level.
To a considerable extent, the dangerous sequence of
events which followed can be related to the lack of
systems knowledge wh ich is apparent here. The pilots
operating h andbook contains the following clear advice
on the hydraulic system:
Pilot deliberately hit' tree at (A) to stop aircraft before the gully at (8).
In the event the hydraulic pump continues to run
(longer than one minute) after completion of a cycle
as evidenced by audible sound from the gear pump
motor and the red GEAR UNSAFE light staying on, it
is recommended that the circuit breaker, labelled
GEAR PUMP, be pulled out to prevent possible
damage due to overheating.
Unfortunately the pilot was not able to connect his
action - cycling the u ndercarriage and resetting the
gear pump circuit breaker - to the r eaction - an
unusual noise originating from the engine/ control
pedestal area.
Contrary to the handbook's instructions, the pilot reset
the gear pump circuit breaker, at least twice. When the
circuit breaker finally remained made, the situation had
been set u p for the h ydraulic pump to overheat.
Eventu ally the overheated power pack fractured its
plastic venting system, allowing hydraulic oil to spray
onto hot components and so causing thick smoke to
billow into the cockpit. T h is convinced the pilot that the
Cessna's engine was on fire.
Putting aside for the moment the fact that the pilot
had completely misinterpreted the symptoms, his
decision to land immediately because he thought th e
engine was on fire cannot be questioned. By the same
token, had his knowledge of two major aircraft systems
- the electrics and the hydraulics - b een better, he
perhaps would have been able to isolate the problem at
an early stage and obviate the urgency to land.
Plastic overflow sump was resting against electric motor and had
been severed (by heat) from the power pack.
(Continued overleaf)
Aviation Safety Digest 127/ 11
�Aircraft accident reports
An explosive combination
••• ,,,,
A 310 litre portable oxygen bottle arrived at an
Engineering Base fo llowing trans-shipment by air.
The bottle had been shipped in a purpose-built box
which was lined with about two ir.ches of
polyurethane foam. Additionally, the bottle had
been packed in polythylene 'bubble plastic'. All
documentation and labelling was correct.
Apparently the bubble plast ic had been used
previously, fo r , on unpacking it was found that one
section was contaminated with what appeared to be
a synthetic oil , perhaps ~v1obil Jet 2. In turn, this oil
had contaminated an area of about five inches by
four inches of the box's foam lining. Oil was also
found on the outside of the oxygen bottle.
Oil and 'pure' (i.e. concentrated) oxygen are a
very dangerous combina tion , having the potential
for spontaneous combustion. In this instance, a
leaking cylinder could have resulted in an explosion,
perh aps inflight.
Immediately following this incident, t'he company
concerned telexed a ll of its personnel who handle
oxygen to instruct them that clean bubble plastic
m ust a lways be used for packing oxygen cylinders. A
Form 225 was also submitted to the Department of
Aviation so that the information could be passed on
to all sections of the industry •
THIRD QUARTER 1985
•
The following information has been extracted from accident data files maintained by the Bureau of A ir Safety Investigation. The
intent of publishing these reports is to make available informat ion on Austral ian aircraft accidents from which the reader can
gain an awareness of t he circumstances and cond it ions which led to the occu rrence.
At the time of publication many of the accidents are still under investigation and the information contained in those reports
must be considered as preli minary in nature and possibly subject to amendment when the investigation is fi nalised.
Readers should note that the information is provided to promote aviat ion safety - in no case is it intended to imply blame or
liabil ity .
Note 1: All dates and times are local
Note 2: Injury classif ication abbreviations
C =Crew
P = Passengers
O =Others
N
M = Minor
S = Serious
F = Fatal
e.g. C1S, P2M means 1 crew member received serious injury and 2 passengers received minor injuries.
N il
PRELIMINARY REPORTS (The following accidents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
05 Jui
Cessna 310L VH-EDK
Charter - passenger operations
C1N,P1N
Deniliqu in NSW/Sydney NSW
8521042
Sydney NSW
2218
The pilot stated that he selected gear down but did not check for a down and locked indication. After having kept sufficient power
appl ied to land well down the runway, t he pilot heard the gear warn ing horn immediately prior to touchdown, but could not prevent
the airc raft land ing with the gear retracted.
Bell 47-G2 VH-SRE
Ferry
C1F,P1F
1630
Ball iang Vic
Balliang Vic 2W/Balliang Vic
8531018
A group of pilots had travel led from a property strip to a nearby dam in order to complete training exercises on a float-equipped Bell
47 helicopter. VH-SRE was not fitted with floats but had been used to ferry some of the pilots to the area. At the conclusion of the
training operation the pi lot arranged to ferry VH-SRE back to the property st rip. After take-off a practice autorotation was conducted
over t he dam and was followed by some unauthorised low flying in the vic inity. On arrival at the strip low level runs were performed
along the strip with torque turns at each end. Control of the aircraft was lost during the third of these turns and the aircraft st ruck t he
ground in a steep nose-down attitude. Fire broke out on impact and engu lfed the wreckage.
13 Jui
Systems knowledge
Non commercial - pleasure
C1N,P1M,P2N
Piper 28-151 VH-PZW
8511 031
Redcliffe Qld
Redc li ffe Qld/Redcli ffe Qld
1700
A fter comp let ing the fi rst lan ding of the intended touch and go, the pilot readjusted the elevator trim, flap and appl ied full power. As
t he speed increased to about 65 knots he attempted to select the climb att itude but found that the elevator control was jammed in
the neutral position. The take-off was abandoned. However, the pi lot was unable to stop the aircraft before it overran the strip and
st ruck a levee ban k. An inspection of the aircraft revealed that a smal l aerosol container had jammed the elevator control cables.
14 Jui
(c ontinued )
The landing
A number of interesting safety lessons emerged from the
landing. To be fair to the pilot, given his assessment
that the aircraft's engine was on fire , getting the aircraft
on the ground was the right priority. He was under
considerable pressure. But - and admitting that 'buts'
can be easy from behind a desk - two of the decisions
he made indicated a poor understanding of the
capabili ties of the aircraft he was operating, to the
extent that the emergency landing was made far more
haza rdous than it should have been. There is absolutely
no value in compounding an emergency by introducing
extra difficulties yourself.
First , the strip was over 400 metres long and h ad
about 120 metres of overrun to the south, which made it
adequate for a short-field landing. However, the pilot
later stated that he lacked confidence in short -field
landings and th is affected his judgment in planning the
approach. An interesting point to emerge here was that
he had flown a short-field approach in his Biennial
Flight Review only fi ve weeks before , but it had been
onto a long strip : in effect , it was a 'simulated' shortfield approach. Whether or not this sort of trai ning
provides sufficient value may be something for flying
instructors to consid er .
12 I Aviation Safety Digest 127
The second point deals with the pilot's decision to
deliberately run into a tree with a wing to stop his
aircraft . As he was travelling at about 40 knots it was a
nea r certainty that the fuel cell in the wing was goin g to
rupture and spray fuel everywhere. This is precisely what
h a ppened. T h us, the perceived fire risk arising from
running into the gully was exchanged for the almost
certain fire risk of smashing the wing. Once the fuel cell
was ruptured and a highly flammable cloud of fuel mist
and spray released, the fire danger was extreme. Finally ,
the pilot's action of returning to the fuel-drenched
cockpit and restoring electrical power so t hat he could
use the VHF radio again created a hig h fire risk.
Conclusion
The systems in GA a ircraft are by and large fairly
straightforward. At the same time, as this accident
shows, the basic operating principles of those systems
m ust be understood by every pilot who operates t hem.
More than th at, the normal and emergency procedures
must be known thoroughly, and pilots must be able to
complete those procedures under pressure . Only by
knowing his a ircraft a nd its systems thoroughly can a
pilot develop the confidence to operate that aircraft
safely to its full capabilit ies •
C1N
Beech 58 VH-RLE
Charter - cargo operations
16 Jui
8521043
Bankstown NSW
Warren NSW/Dubbo NSW
2000
The pilot reported that after take-off the landing gear cou ld not be fully ret racted. On arrival at Dubbo efforts to lower the gear by
normal and emergency means were unsuccessful. The pilot elected to divert to Bankstown and subsequently landed on the partially
extended gear. The nosegear collapsed and the aircraft slid to a halt.
Cessna 150L VH-DGZ
Non commerc ial - business
C1M,P1M
Noosa Heads Qld/Roma Qld
8511 032
1200
Roma Qld 6E
Before departure the pilot dipped the fue l tanks and estimated there was suff icient fuel to complete the planned f light. Approach ing
the destination the engine stopped. The pilot selected a road on a newly developed housing subd ivision as the on ly su itable landing
area and an approach was made into the north-east with a tailwind of about 15 knots. A fter to.u chdown the pilot was unable to stop
the aircraft before a sharp bend in the road. He brought the aircraft to a stop by steeri ng it between two po les.
16 Ju i
...
C1M, P1N
17 Jui
Bell 206B VH-FJR
Charter - aeri al ambu lance
Jandakot WA/Lancelin WA
8551015
1920
Lancelin WA
The pilot was posit ioning the helicopter, before carrying out a medical evacuat ion from a sh ip. During a night approach to a pad, lit by
car headlights, the helicopter collided with sand dunes.
Ryan STM VH-CXR
Air show/air racing/air trials
C1 F
1655
Wyndham WA
Wyndham WA/Wyndham WA
8551016
At the end of the display the aircraft was observed to enter a spin at a height of between 800 and 1000 feet ag l. Four turns of t he sp in
were completed, and the witnesses reported that recovery action had been taken j ust before the aircraft struck the ground.
20 Jui
Beech V35-MK2 VH -DYS
Non commercial - pleasure
C1 F,P3F
0738
Mataranka HS NT
Mataranka HS NT/Tindal NT
8541013
The aircraft was observed to take-off and climb to about 150 feet above the strip. It then entered a steady, wings level descen t and
collided with trees 500 metres beyond the strip. The aircraft was destroyed by impact forces and the ensuing fire.
02 Aug
Aviation Safety Digest 12 71 i
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
03 Aug
Hiller UH12-E VH-FFX
Ferry
C1N,P2N
0755
Hughenden Old
Hughenden Old/Mt Pleasant Old
8511034
At about 400 feet agl on cl imb, the helicopter suffered a partial loss of eng ine power. During t he subsequent landing flare the pil ot
misjudged the power available and the helicopter was landed heavily, collapsing the skids.
05 Aug
Cessna 1820 VH -TGJ
Non commercial - business
C1 M
1220
Dalbeg Old
Strathmore Stn Old/Dalbeg Old
8511 036
After touchdown, the pilot applied gentle braking but believed the aircraft was not decelerating. To avoid running off the end of
the strip he attempted a ground loop, however, the aircraft ran off the side of the st rip and struck a vehicle.
07 Aug
C1F
Beech 65 A80-8800 VH-FDR Supplementary Airline
Brisbane Old/Rockhampton Qld
8511037
0546
Biloela Qld 37NE
Thi s aircraft had only recentl y been acquired by the company and had a different fuel system from others of the same type in the
fleet. The pilot had not flown this aircraft previously. After a flight time of about 110 minutes the pilot reported that both eng ines
had stopped and he was unabl e to transfer fue l from the outboard tanks. When the wreckage was located no evidence of fuel was
found in the inboard tanks, however, some ev idence of fuel was found in the outboard tanks.
09 Aug
Cessna 182N VH-EKF
Non commerc ial - pleasure
C1 N,P1 N
1545
Burketown 26NW
Urapunga Qld/Burketown Qld
851 1038
Approaching the destination, the engine began to run roughly. As the aircraft was losing altitude the pilot se lected a track
running through the scrub as the only suitable landing area. During the landing roll both wings st ruck t rees and the aircraft ran off
the track.
Non commercial - business
C1F,P2F,P1 S
13 Aug
Cessna 182H VH-KMM
Kununurra WA/Ord River HS WA
1027
Ord River HS WA
8551020
The destination was served by two landing sites - an A LA near the homestead and a licenced st rip 12 kilometres to t he north.
The pilot elected not to use either, but made an approach to a road adjacent to the homestead. The usable lengt h of this road was
450 metres and the width was less than 3 metres. The approach was made over a shed in light downwind conditions. Touchdown
occurred about 200 metres from the end of the road, and the pilot then attempted to go around. Duri ng this attempt the aircraft
struck two wire fences before colliding heavily with a tree. Fire broke out and gutted the w reckage.
18 Aug
Cessna U206-G VH-APH
Non commercial - pleasure
C1 N,P4N
1610
Oodnadatta SA
Leigh Creek SA/Oodnadatta SA
8541014
After touchdown the aircraft began a series of bounces. The pilot initially attempted to control the ai rcraft wit h the elevators but
then appli ed full power to go-around. However, the aircraft struck the ground in a nose-down attitude tearing off the nosewheel
and bending the propeller blades.
19 Aug
Charter - cargo operations
Gates 35A VH-WFE
C2N
0600
Tindal NT
Alice Springs NT/Tindal NT
8541016
The aircraft was making a landing at first light. During the landing ro ll a wallaby was seen bouncing towards the aircraft. The
animal was struck by the left maingear leg and the force of this collision resulted in a port ion of the wallaby being f lung into the
left flap.
20 Aug
1720
Cessna 182K VH-KRH
Batchelor NT
Sport parachuting (not associated with an
airs how)
Batchelor NT/Batchelor NT
C1 N,01 S,03N
8541017
As the four parachutists were preparing to jump from the aircraft, the reserve parachute, of t he parachu ti st who was stand ing on
the wing strut of the aircraft, deployed. The reserve parachute was ejected forward over the leadi ng edge of t he wing causing the
parach utist to be dragged over the wing before falling from the aircraft. During the subsequen t descent t he parachutist re leased
the main parachute which fai led to fully deploy. In an effort to reduce his high rate of descent he steered towards a large t ree
contacting the branches before fal ling to the ground.
24 Aug
Charter - passenger operations
Cessna 310L VH-KVY
C1 N,P2N
Harden NSW
Tumut NSW/Dubbo NSW
1700
8521046
About 20 minutes after take-off and while cruising at 4500 feet amsl, the right engine suddenly lost al l power. The pilot reported
that he was unable to restore power, and he elected to land at a nearby ALA. From the downwind positio n a co ntinuous left turn
was flown to align the aircraft with the strip. On short final approach the left engine also lost power and the aircraft touched down
short of the strip boundary. It ran through two fences and the nosegear collapsed after striking a dirt bank.
26 Aug
Cessna 210M VH-ROD
Charter - passenger operations
C1N ,P5N
Punmu WA
Jiggalong WA/Punmu WA
1625
8551021
About 150 metres after a normal touchdown the aircraft began to veer to the right. The pilot was unab le to regain directional
control and the aircraft ran oft the strip, through a gully and collided with a tree. While the ai rcraft was being vacated , a fire was
noticed around the right wheel area. Thi s fire was controlled by use of the portable ext inguisher. A subsequent examination of
the strip revealed marks indicative of heavy, intermittent braking forces being applied to the righ t wheel during the landing ro ll.
28 Aug
Cessna 180K VH·APW
Non commercial - practice
C1 N,P1 N
1142
Parafi eld SA
Parafield SA/Parafield SA
8541015
The pilot, who had j ust pu rc hased the aircraft but had littl e experience on tailwhee l types, had compl eted two hours o f trai ning
the previous day. On the fo llowing morning he intended to further famili arise himse lf wit h the ai rc raft, by carrying out a number of
circ uit s. During an attempted three-point landing the left wingtip struck th e runway and d irectional control was los t. The aircraft
veered off the runway and came to rest outside th e flight strip.
ii / Aviatio.n Safety Digest 12 7
Date
Time
A ircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
02 Sep
Cessna 1820 VH-DFR
Non commercial - pleasure
C1 N,P2N
1118
Wagga NSW
Longwarry Vic/Wag ga NSW
8521048
Durin g his pre-fli ght inspection, t he pilot detected water in the fue l samples from the various drain points. Further samp les were
taken until no trace of water was evident. The subsequent f light of almost 90 m inutes was uneventful, unt il the pi lot se lected full
flap on f inal approach to land. At thi s point the en gine lost all power and during the ensu ing forced landing the ai rcraft coll ided
w ith a fence post. Investigation revealed t hat the fuel caps were not provid ing adequate seal ing, and a substantial amoun t of
water remained in the fuel system. Prior to the flight the aircraft had been parked in the open for some days and considerable
amounts of rain had fallen.
04 Sep
Cessna 31 0R VH-TWO
Supplemen tary Airline
C2N
0855
Pt Hedland WA
Pt Hedland WA/Pt Hedland WA
8551022
Prior to touchdown the gear posi tion indicator indicated that t he gear was down. During the landing ro ll the right main gear
col lapsed and the right wing, engine, propeller and flap struck the ground.
06 Sep
Piper 32-TR300T VH-CXX
Non commercial - pleasure
C1 N,P5N
1205
Mudgee NSW
Mudgee NSW/Moorabbin Vic
8521049
Shortly after t ake-off a loud bang ing noise was heard from t he inboard area of the r ight w ing. The pilot elected to fly a low level
c ircuit and land to invest igate the noise. On short f inal approach heavy sink was encou ntered, and despite the application of
power the airc raft touched down about 100 metres short of the runway. It ran thro ugh the airport boundary fence and came to rest
near the flight strip with the gear collapsed. Investi gation revealed t hat a sect ion of the door seal had become unstuck and had
t railed in the slipstream, beating again st the door.
06 Sep
Avnspier Rob in-R21 60 VH-NRK Non commercial - pleasure
C1 N,P1 N
1245
The Oaks NSW 4NE
The Oaks NSW 4NE/The Oaks NSW 4NE
8521050
The pi lot was conducting a fli ght in the local training area. He reported t hat as he applied power to climb from 2000 to 3000 feet
amsl the eng ine sudden ly sto pped completely. Efforts t o regain power were unsuccessful and during the ensu ing forced landing
the right wing struck a dead tree.
07 Sep
Rawlins RW Rand KR2 VH-LLLNon com mercial - pleasure
C1S
1230
Camden NSW 10NE
Camden NSW/Camden NSW
8521051
The pilot reported that while the aircraft was in cru ising flight it suddenly began to vibrate heavily. The pilot closed the throttle
but the violent vibratio n cont inued. The s urroundin g terrain was generally unsuitable for a forced land ing, and in the latter stages
of an approach towards a small paddock the right w ing struck a tree. The aircraft then dived into the ground and was destroyed. It
was subsequently determ ined that more t han half of one of the two propel ler blades had separated in f light.
08 Sep
Evans VP2 VH-SJX
Non commercial - pleasure
C1N
0700
Manton Old
Manton Old/Manton Old
8511041
The pi lot stated that at about 70 feet agl on climb after take-off, the aircraft encountered turbu lence. As he was app ly ing lef t
aileron to counter the tu rbulence, the engine s uddenly stopped. The pilot checked the posit ion of the f uel selector and turned t he
aircraft towards a cleared area. The airc raft was landed in a t imbered area about 550 metres beyond the end of the strip. When the
aircraft cam e to a stop t he pilot noticed that t he ignit ion switch was in the off position .
23 Sep
Aero Comdr 500A VH-I OE
Aerial Agricu lture
C1 N,P2N
1702
Po rt Hedland WA
Pardoo WA/Pardoo WA
8551024
After the gear was selected down, no down indication was received for the right gear leg. The pi lot decided to divert to Port
Hedland where engineering advice was avai lable. When it was decided that all t he opt ions were exhausted, the pilot landed the
aircraft. As the r ight wheel contacted the ground the leg collapsed and the aircraft s lid to a stop.
25 Sep
Cessna 152 VH·FUR
Instruct ional - solo (supervised)
C1 N
1205
Arc herfield Old
Archerfield Qld/Archerfield Old
8511043
On the third landing of the exerc ise, t he pilot stated that the aircraft touched down on al l th ree wheels and bounced. The aircraft
was then observed to lan d on the mainwheels t hen the nosewheel. The nosegear collapsed and the aircraf t skidded for 33 metres
on the lowe r eng ine cowl before coming to rest.
29 Sep
Cessna 185A VH-AGI
Sport Parachute Ju mp
C1 N
1445
Collie WA 60E
Hi llman Farm WA/H illman Farm WA
8551026
At the c onc lusion of a parachu te droppi ng sortie, t he pilot landed the aircraft at the strip in a strong crosswi nd. During the
landing rol l the aircraft began to swin g to the left and t he right gear leg collapsed. The ri gh t wing, tai lplane and elevator were bent
after co ntact ing the ground.
FINAL REPORTS (The investigat ion of the following accidents has been completed)
Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
17 Jui
Cessna 172M VH-DXE
Non commerc ial - bus iness
C1 N,P1 N
1545
Windo rah 140NW
Palparara Sin Qld/Windorah 140NW
8511033
Commercial
19
357
104
Inst rument rating c lass 4
After landin g on a claypan, the pi lot taxied the aircraft along a track to pick up a passenger. The right mainwheel entered an area
of bu lldust and t he aircraft swung to the right off the track. As the pi lo t was manoeuvring the aircraft back onto the t rack t he righ t
wing struck a t ree .
The pi lot was attempt ing to save t ime by taxying towards the passenger. Forward visibility was impai red as t he pilot was
looking into the sun and there was glare on the w indscreen. The tree st ruck was the only obstruction in the area.
Aviation Safety Digest 12 7I iii
�,r
Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
Date
Time
Pil ot Licence
Aircraf t type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
C1M
27 Jui
Piper 28-151VH-PMW
Instructional -solo (supervised)
8521045
1320
Orange NSW
Orange NSW/Orange NSW
Student
32
12
12
None
During the fifth touch-an-go landing of a period of solo circuits the student pilot appl ied right rudder in antici pation of the
expected swing as take-off power was applied. The aircraft immediately swung to the right and the student, becomi ng confused ,
applied further right rudder pressure. The aircraft left the runway and impacted a ditch outside the f light strip. The pilot was not
using the sash component of his seat belt and he suffered a facial laceration when he struck the instrument panel during the
impact.
29 Aug
Robinson R22 VH -CIU
Instruc tional - solo (supervised)
01 N
1253
Hoxton Park NSW
Hoxt o n Park NSW/Hoxton Park NSW
8521047
Stud. - helicopter
41
23
23
None
Following an hour of dual assessment f ly ing, the inst ructor aut horised t he student to perform his first so lo f light. As soon as the
helicopter was lifted into t he hover, it began to move to t he rig ht. The right skid contacted the ground, th e aircraft ro lled to the
right and came to rest on its side.
Although he had been br iefed on the d ifferent hand ling characterist ics of the ai rcraft when on ly one person was on board, the
student had evidently not anticipated the degree of chan ge which wou ld occu r.
29 Jui
Cessna 185B VH-KPA
Jandakot WA
1141
Senior commercial
C1N
Aerial mapping/photography/su rvey
8551017
Jandakot WA/Jandakot WA
Instrument rating 1st class or
1850
5
24
class 1 with instrument ratin g
Towards the end of the landing roll the aircraft began to diverge to the right. The pilot unsuccessfully attempted to correct the
situation and the aircraft ground looped. The left main gear leg was broken off and the left wing, tailplane and the propeller st ruck
the ground.
The pilot was inexperienced on tailwheel aircraft and the landing was conducted in light quartering tailwind condit ions.
06 Sep
Robinson R22 VH-PYG
Instruct io nal - check
C2N
1030
Jandakot WA
Jandakot WA/Jandakot WA
8551 023
Senior
38
6550
125
Flight instructor grade 1 or 2
corn. - helicopter
w ith instrument rating
Du ring the test, the exam iner warned the student that he was about to s imulate an eng ine fai lure during taxying , req uiring a
landing from a height of two feet. As t he examiner closed the th rottl e gently, the student immed iately ap plied f ul l right pedal. The
examine r attempted to reverse the cont ro l input with left pedal, but the helicopter struck the ground heavily on the rear of t he left
skid. This resulted in the bending of the engine mount ing frame.
03 Aug
Piper 28-180 VH-PIH
Non commercial - aerial application/su rvey
C1N
8511035
0900
Ouilpie Old 75SSW
Bowalli Old/Bowalli Old
Private
34
531
200
None
The pilot was carrying out an inspection of water points on his property. The inspection was f lown at an altitude of about 500 feet
agl and involved sustain ed turns at an angle of bank of about 40 degrees over the water points. Just after the recovery from one of
these turns, the engine began to lose power. After unsuccessfully attempting to recti fy the problem, the pilot decided to land on a
cleared area. The aircraft landed heavily short of the area and collided with trees.
At the moment of engine failure, the engine was drawing fuel from the right hand tank and the corresponding fuel gauge
Indicated less than a quarter full. An inspection of the aircraft did not reveal any mechanical reason for the loss of power.
However, it is probable that the turns were uncoordinated and the fuel tank outlet became uncovered because of the low f uel
quantity, in the right tank, resulting in a loss of power from fuel starvation.
18 Sep
Hillier UH12 VH-UHB
Aerial agriculture
C1N
1225
Ipswich Old 40SSW
Kalbah Old 3NW/Kalbah Old 3NW
8511042
Com. Helicopter
35
8309
2098
Agricultural c lass 1
Prior to the commencement of t he sprayi ng operat ion, the pi lot carried out an aeri al survey of the area not ing t he posit ion of all
wires. On t he first ru n, t he ai rcraft was f lown under bot h sets of wires. When the run in t he o pposite d irecti on was commenced,
t he pi lot intended f ly ing the heli copter over the fi rst set of lines and under the second set of lines. However, the helicopt er
collided w ith t he second set of lines and impacted the ground 70 metres beyond t he wires.
The pi lot st ated that he had forgotten about the second set of w ires and was fly ing the aircraft higher above t he crop t han
normal. The previous nigh t t he pilot had had a distu rbed sleep and was probably sufferin g some fatigu e.
06 Aug
Piper 18-150 VH-WOO
Training
C1N
1700
Mullewa WA 20N
Mullewa WA 20N/Mullewa WA 20N
8551018
Private restricted
27
68
25
None
At the conclusion of a property inspection the pilot decided to practice a glide approach in 15 knot wind condit ions, which gave a
light crosswind on the selected strip. Initial touchdown was on the tailwheel and the aircraft bounced. After the next touchdown
the aircraft commenced to run off the side of the strip. The pilot applied power to go-around but the propeller struck the ground
and the aircraft came to rest on its nose in a paddock adjacent to the strip.
When the aircraft bounced, the pilot had not maintained the control inputs requi red to compensate for the c rossw ind, and after
the subsequent touchdown the aircraft had commenced to weather-cock. Having ap plied power to go-around , the pi lot had.
progressively pushed forward on the control stick, in the belief that the tailwheel was stil l on t he ground.
C1N
11 Aug
Burkhart Astir CS VH-WOJ
Non commercial - pleasure
1735
Bundaberg 12SSW
Gliding strip/Glidi ng strip
8511039
Glider
34
261
42
Glider
The pilot intended to land the glider as cl ose as possible to the hangar. On fi nal , speed was increased to make good the
to uchdown point, then the aircraft was held in level f light at about 20 feet above the strip. As the landing gear was se lected down,
the nose dropped and the glider impacted the runway heavily. The landing gear fai led and the g lider s lid for 47 met res o n its lower
fuselage before coming to rest.
The elevator trim had been set nose down for high speed flight, and although a trim check is required, it was om itted from the
pre-landing checks. The pilot claimed that when he changed hands to lower the gear, the nose trim pulled the control st ick from
his grasp which resulted in the nose drop and the subsequent heavy landing.
11 Aug
Piper 28-140 VH-PPL
Non commercial - practice
C1M
8551019
Brooklands WA/Brooklands WA
1130
Kweda WA 85
63
40
20
None
Student
During the downwind leg of the circ uit the student pilot noticed some sheep moving between paddocks . He extended the
downwind leg to watch the sheep. After establishing the aircraft on final the pilot realised t he approac h pat h was lower t han
normal but he took no corrective action and the aircraft struck an earth bank wh ich ran across the approac h end of the st ri p.
The pilot was undergoing training at a local flying club and had limited solo experience. He was concerned that he may lose his
level of profici ency and he decided to c onduct a period of solo c ircuit practice, in his ow n aircraft , at his property airstrip w itho ut
first contacting his in stru cto r. The earth bank was located close to the strip threshold whic h was not c learly def ined.
18 Aug
Piper 28-161 VH-PZH
Non commercial - pleasure
C1N ,P1N
1628
Cairns Old
Cairns Old/Cairns Old
851 1040
Private
41
210
35
None
The pilot int ended to drop a flour bomb at a local cricket ground. He subsequent ly advised that during t he run-in to d rop the bomb
at 400 feet agl a downdraft was encountered. Full power was rapidly applied but the engine faltered and the airc raft collided w ith
the top of a tree at a height of about 35 feet agl. Some 40 people were gathered under thi s t ree at t he ti me. The impact shattered
the windsc reen and the cockpit was fill ed with deb ris, and a 2 metre limb remain ed attac hed to the horizontal stabi liser. The pi lot
was able to retain co ntro l of th e airc raft and a safe landin g was carri ed out at the dest inati on aerodrome.
No evidence was found to support the pil ot' s claim that the airc raft was affected by a downd raft. It was poss ibl e that t he pi lot
was dist racted by the actio ns required to dro p the flour bomb, and did not pay sufficient attention to the area ahead of t he
qircraft.
iv I Aviation Safety Digest 1 2 7
20 Sep
Cessna 150G VH-RZD
Non commercial - pleasure
C1N
1500
Muresk WA
Muresk WA/Muresk WA
8551025
Private
59
777
450
None
Earlier in the day the pilot had f lown the aircraft from hi s farm to Muresk. Because no fuel was availab le at Muresk, he dec ided to
f ly the aircraft to Northam, 13 kilometres to t he north . Just after the aircraft became airborne, the eng ine lost power. The pi lot was
committed to landing in a paddock. Duri ng the landing sequence the aircraft struck a f ence and ran over a depressed roadway,
tearing off the nosegear.
Th e loss of power was d ue to f uel exhaust ion. Prior to commencing the take off, the pi lot did not check the quanti ty in t he fuel
tanks, nor d id he calcu late the remaining fuel endurance.
Inst ruc tional - solo (supervised)
C1N
22 Sep
Cessna 150 VH-FMG
1210
Camden NSW
Camd en NSW/Camden NSW
8521052
32
32
Student
45
None
After flaring too high the student pilot continued w it h the landi ng attempt but th e aircraft struck t he runway heavily then bou nced
several times. The nose gear assembly was d istorted and the engine sup port frame was bent.
27 Sep
Thorpe T1 8 VH-ELW
Inst ructional - t rainin g
C2N
1750
Cairns Old
Cairns Old/Cairns Old
851 1044
Private
No ne
49
650
500
The pilot in command, who was also the owner of the aircraft, was act ing as t he safety pi lot for the other pilot , who had o nly
recently received trai ning on t he aircraft. Th is was the f irst occas ion on wh ich the co-pi lot had flown the airc raft from the righ t
hand seat. He flared the aircraft too high on t he f irst ci rcu it and was advised by the pilot in command that the flare had been
commenced too early. As he attempted to reposition the aircraft closer to the runway it struck the runway heavi ly and bounced.
The co-pilot inadvertent ly closed the thrott le and t he aircraft struck the runway in a nose down at titude. Damage was caused to
the propeller, engine firewall and the gear.
FINAL UPDATES (The investigation of the foll owing acc idents has been co mplet ed. The
information is additional to or repl aces t hat previous ly printed in t he prelimi nary re port.)
Date
Time
Aircraft typ e & regis tration
Location
Age
Hours Tota l
Pilot Licence
Hours on Type
Rating
Record
Number
27 Feb 83
Cessn a 172 VH -DOX
Private
8341007
181 0
Lei gh Creek Sth
24
78
19
None
The pil ot f lared the aircraft for landi ng but then decided he was un dershoot ing and applied full power to go-around. The aircraft
climbed to about 7 feet when the left wing dropped and struc k t he ground . Th e aircraft yawed sharply to the left and t he nose
stru ck the ground heavily .
The pilot was lat e in detecti ng the undershoot but when f ull power was applied to correc t this, he fai led to adj ust the pitch
att it ude and the ai rc raft stalled.
A viation Safety Digest 12 7I v
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record
number
Rating
05 Jun 83
Cessna 182P VH-IRL
Private
8341016
1125
Brunette Downs NT
26
122
16
None
After crossing the threshold at 75 knots power was reduced to idle and a landing flare commenced at about 25 feet agl. The aircraft
floated for some distance before the nosewheel contacted the ground heavily 400 metres from the threshold. A bounce ensued
followed by a further heavy touchdown on the nosewheel which then collapsed and was torn off as the aircraft slid on its nose for 98
metres.
20 Jun 83
Bell 47-G5A VH-AAW
Commercial - helicopter
8311038
1715
Normanton Old 59S
29
272
106
Agricultural class 1
On the morning of the accident a periodic inspection had been completed on the aircraft. Following this inspection, the pi lot,
accompanied by an engineer, carried out a successful test flight in the helicopter.
The pilot then lunched with the engineers and after farewelling them at the airport was driven to the helicopter to prepare for the
flight back to the mustering camp.
The helicopter was later observed by a stockman who was travelling in a vehicle towards the mustering camp. When the helicopter
was first seen it was flying at a height of about 200 feet above the tops of the trees in the direction of the camp. It then seemed to
apparently stop, turn abruptly through 90 degrees to the left, roll to the left and spin through 360 degrees before impacting the
ground inverted. At about the same time as the helicopter turned to the left an object was seen to fly horizontal ly away from the
aircraft to the right. After ground impact a fire broke out and engulfed the wreckage.
An extensive search of the area failed to locate the object that had fallen from the helicopter. However it is believed that the object
may have been one of several cans of oil or grease the pilot was known to have carried in the aircraft.
The examination of wreckage did not reveal any defect in the helicopter which was likely to have contributed to the occurrence.
The reason for the loss of control by the pilot could not be determined.
28 Feb 84
Cessna 182B VH-RFG
Private
8441007
1230
Goober Pedy SA
25
294
31
Instrument rating class 4
The pilot reported that the aircraft was higher than normal during the approach to land in crosswind conditions. The aircraft touched
down heavily and bounced. Control was not regained and the aircraft stalled at about 10 feet above the runway. It then struck the
ground in a nose down attitude, sustaining damage to the forward fuselage and the propeller.
The pilot lacked recent experience on the aircraft type. A go-around was not initiated after the aircraft bounced on landing.
09 Mar 84
Cessna T188C VH-MXJ
Commercial
8411010
0641
Ayr Old 8WNW
39
12000
5000
Agricultural class 1
Shortly after take-off for rice spraying operations the pilot noticed that engine power was decreasing. He was unable to prevent a
continuing loss of power and after dumping the hopper load he attempted to guide the aircraft towards a relatively clear area. One
gear wheel entered the rice crop and the aircraft swung into an adjacent cane crop and overturned.
The pilot was able to kick out a window and escape from the aircraft which appeared not to have suffered extensive damage.
Whilst the pilot was absent from the site an explosion was heard and the aircraft was destroyed by fire. Investigation was hampered
by the effects of the fire and the reasons for the loss of engine power and subsequent fire were not established.
24 Mar 84
Cessna 150G VH-KUB
Private restricted
8421013
0930
Deniliquin 32N
33
350
220
None
At about 300 feet after take-off the pilot noticed a restriction in forward movement of the control yoke. He carried out a landing in a
paddock to his left but the aircraft struck a levee bank and overturned.
The cause of the control yoke restriction reported by the pilot could not be determined.
21 Apr 84
Cessna 210 VH-RHK
Private
8421019
1340
Pt Macquarie NSW
27
230
30
None
When the landing gear was selected down it failed to extend. The pilot attempted unsuccessful ly to extend the gear using the
emergency system and by the application Af 'g' forces. Touchdown was made with the main gear up and the nose gear partially
extended. The filter in the landing gear hydraulic system was found to have a cracked housing and all the oil in the system had been
lost.
The reason for the crack in the housing was not established.
22 Apr 84
1050
Bell 206-B VH-UTS
Nunawading Vic
helicopter
8431014
Instrument rating 1st class or
class 1 with instrument rating
During the take-off, the engine instruments were checked while the helicopter was in a hover and no abnormalities were noted. Just
as forward movement was commenced a loud noise was heard and all engine power was lost. A significant drop in rotor rpm
occurred and the main rotor struck the tail boom during the subsequent forced landing. Inspection revealed a total mechanical
failure of the engine compressor.
The majority of compressor blades were found to be broken and the resulting degree of damage precluded identificat ion of the
location of the initial failure. However, the examination of sections of blades revealed corrosion pitting consistent with inadequate
compressor washing servicing. The aircraft had been operating in a corrosive atmospheric environment and it is probable that the
initial failure within the compressor resulted from corrosion induced fatigue.
37
6700
Commercial 2000
11May84
Hiller UH12·E VH-FFX
Commercial - helicopter
8411021
1200
Pretty Plains HS
34
3560
3540
None
While returning to refuel at a mustering yard, the pilot attempted to move a bull from some trees. When this proved unsuccessful t he
pilot climbed to continue the flight to the yard. The engine began to run roughly and an approach to a clearing was made. Rotor rpm
decayed as some trees were cleared and the pi lot was unable to prevent a heavy landing. The helicopter bounced about two metres,
the right skid collapsed and the main rotor struck the ground.
Investigation revealed that the engine failed due to fuel exhaustion. The pilot's tech nique was to work on a set endurance from fu ll
tanks and not rely on the fuel gauge. At the previous refuelling he filled the tank to the filler neck, but the helicopter was parked on a
slope which prevented approximately 20 per cent of the tank's volume from being used, and reduced the endurance.
vi !Aviation Safety Digest 127
12 Jui 84
Transav PL12 VH-BPR
Commercial
8421034
1545
Tumbarumba 24W
39
13466
10000
Agricu ltural class 1
Superphosphate spreading operations had been carried out throughout the day. During the subject take-off attempt the aircraft
began to pull to the left shortly after full power was applied. The pilot abandoned the take-off and as he did so the left main gear
collapsed. The aircraft groundlooped and came to rest 70 metres from the start of the take-off roll. Investigation revealed that the left
main gear pivotting lugs had fractured.
The failure of the gear pivotting lug was probably caused by operations on rough and unprepared strip surfaces. There was no
evidence of fatigue and the failure was considered to be an isolated occurrence.
01 Aug 84
Robinson R22 VH-UXD
Private - helicopter
8411033
1100
Brooklyn Sin Old
45
2890
890
None
The pilot landed the helicopter to allow his passenger to alight. The engine was left running, the cyclic frictioned and collective held
fully down. The pilot then felt a low frequency vibration begin and almost immediately the left side of the helicopter lifted and the tail
swung to the right. Control inputs by the pilot had no effect and the helicopter rol led onto its s ide.
One of the four belts providing drive to the transm ission had jumped off the sheave, for reasons which cou ld not be establ ished.
The belt had become wrapped around the clutch shaft and had caused a sudden braking action to the main rotor blades. Th is braking
force was of such a magnit ude that the fuselage yawed in an inertia reaction. The right skid dug into the soft ground and a dynamic
roll-over resulted.
07 Aug 84
Cessna 210L VH-EJC
Private
8421037
1548
Bankstown NSW
46
1600
100
Instrument rating class 4
On arrival in the destination circuit area the pilot was unable to obtain a safe " down and locked" indication for the landing gear. A
diversion to a more suitable aerodrome was carried out and after all efforts to lock the left main gear down were unsuccessful, a safe
landing was made with all wheels retracted. Damage was confined to the propeller blades and t he under skin of the fuselage.
The right main gear would not lock down because the lock mechanism was corroded and dirty. The corrosion and foreign matter
prevented the down lock hook from positioning correctly.
20 Aug 84
Airtract AT301 VH-IXL
Commercial
8411037
1645
Ingham Old 1S
30
6400
60
Agricu ltural class 1
As the pilot was manoeuvring the aircraft to commence another bait ing run, the engine lost all power. The aircraft was landed in a
paddock of young sugar-cane. After a ground roll of 90 metres the main wheels dug into the ft..rrows across the paddock and the
aircraft nosed over. A fire broke out and engulfed the wreckage.
An inspection of the carburettor found that the float valve was loose in the carburettor body. This would have resulted in the
carburettor flooding , which in turn probably caused the engine to fail. Because of the altitude at which the aircraft was operating
insufficient time was available for the pilot to manoeuvre the aircraft for a landing on more suitable terrain.
26 Aug 84
Schneider ESKA6 VH-GOK
Glider
8451021
1333
Cunderdin WA
25
65
34
Glider
While being towed to the planned launch height, the glider under tow and another glider in the circu it area collided. The collision
caused the tow rope to break and the pilot of the glider, although injured, was able to land his aircraft. The tailplane of the other
glider separated in the collision and the aircraft descended uncontrolled into the ground. The tug aircraft was undamaged and
landed safely.
The glider rejoin ing the c ircuit approached the tug and glider under tow from the right rear quarter. Immediately prior to t he
collision, witnesses reported that the glider attempted avoiding action. The reason the pilot did not see the two other aircraft until it
was too late to successfu lly take avoid ing action could not be determined. However, the combination of a broken cloud cover and a
mottled background would have made the pi lot's task more difficult.
26 Aug 84
De Hav C1 A1 VH-RJK
Commercial
8451021
1333
Cunderin WA
38
1486
80
Instrument rating class 4
While being towed to the planned launch height, the glider under tow and another glider in the c ircuit area co llided. The collis ion
caused the tow rope to break and the pi lot of the glider, although injured, was able to land his aircraft. The tailplane of the other
glider separated in the collision and the aircraft descended uncontrolled into the ground. The tug aircraft was undamaged and
landed safely.
The glider rejoining the circuit approached the tug and glider under tow from the right rear quarter. Immediately prior to t he
collision, witnesses reported that the glider attempted avoiding action. The reason the pilot did not see the two other aircraft until it
was too late to successfully take avoiding action could not be determined. However, the combination of a broken cloud cover and a
mottled background would have made the pi lot's task more di ff icult.
26 Aug 84
Czech Blanik VH-WUT
Glider
8451021
1333
Cunderin WA
48
101
Glider
While being towed to the planned launch height, the glider under tow and another glider in the circuit area collided. The collision
caused the tow rope to break and the pilot of the glider, although injured, was able to land his aircraft. The tailplane of the other
glider separated in the collision and the aircraft descended uncontrolled into the ground. The tug aircraft was undamaged and
landed safely.
The glider rejoining the circuit approached the tug and glider under tow from the right rear quarter. Immediately prior to the
collision, witnesses reported that the glider attempted avoiding acti9n. The reason the pi lot did not see the two other aircraft until it
was too late to successfully take avoiding action could not be determined. However, the combination of a broken cloud cover and a
mottled background wou ld have made the pilot's task more difficult.
05 Sep 84
Cessna 210N VH-FOK
Private
8451022
1300
Go Go Station WA
43
6570
130
None
The pilot selected a 340 metre long taxiway as the take-off path. After a ground rol l of about 250 metres, at an indicated airspeed of
approximately 55 knots, the pilot rotated the ai rcraft but did not become airborne. He then closed the thrott le and the aircraft ran off
the end of the taxiway and collided with several trees.
The pilot was unfamiliar with the airfield but had been advised that the strip was 915 metres long. He was unaware that the take-off
path he had selected was along the taxiway which led to the strip. Prior to the attempted take-off, he had been involved in an
argument with his employer and was probably also fatigued after a week of extensive business travel.
Aviation Safety Digest 127I vii
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record number
Rating
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record
number
Rating
20 Sep 84
1743
Cessna 210M VH-MGI
Tocumwal NSW
Senior commercial
8421050
380
Flight instructor grade 1 or 2 with
instrument rating
On downwind after the first take-off following a scheduled servicing the pilots were unable to fully extend the landing gear. After all efforts
to lower the gear by normal and emergency methods were unsuccessful, the pilot in command carried out a safe landing with the gear
retracted.
Part of the work carried out during the servicing included the replacement of 'O'-ring seals in the main gear up-lock valve. During reassembly of this valve, a ball bearing, whose function was to direct fluid to the actuator was omitted. When the system was activated
insufficient pressure could be generated to fully extend and lock the gear.
'
'
28
3505
27 Sep 83
Hughes 269C
Commercial - helicopter
8311064
1400
.
Black Gin Yard Old SS
32
3600
2100
Instrument rating c lass 4
As the helicopter was brought to a 20 foot hover, it began to swing to the right. The pilot applied left pedal but the rate of turn continued to
incre~se rapidly until .the heli?opter impacted the ground. The right skid broke off and the aircraft came to rest on its right ~and side.
Examination of the tail rotor pitch control system revealed that the bolt which connects the tail rotor pitch control arm to the control rod,
below the tail rotor gearbox, was missing. The bolt was never found and the reason for its absence cou ld not be determined. It was evident
that the loss of the bolt resulted in the loss of tail rotor control.
23 Oct 84
1834
Piper 34 200T VH-SVM
Moorabbin Vic
Senior commercial
8431032
50
Flight instructor grade 1 or 2 with
instrument rating
Touchdown on a simulated asymmetric landing was reported as firm and with a slight bounce. During the ground roll the right wi ng
settled to the runway and the aircraft came to a halt off the side of the runway. The right hand main landing gear leg was found to have
fractured below its pivot point.
Fa!lure of the undercarriage leg resulted from fatigue cracking which originated at an area of corrosion within the gear leg trunnion
housing.
45
8100
25 Nov 84
Britnor 2-A21 VH-ISI
Commercial
8421067
1250
Wilton NSW 1N
21
444
225
Instrument rating class 4
~ta height of about 200 feet after take-off the right engine lost power. The pilot feathered the propeller and commenced a gentle left turn
1n order to return to the strip. He later advised that the aircraft began to sink towards some large trees and he was forced to increase the
angle of bank in an effort to avoid them. Shortly afterwards the aircraft struck the ground heavily in an adjacent paddock about 1 kilometre
from the strip.
The engine failure was caused by jamming of accessory drive gearing as a result of the effects of excessive wear within a magneto. It
was probable that a mandatory inspection of the magneto which fell due 84 flying hours before the accident was not conducted. On takeo!f the aircraft weight exceeded the authorised limit, however fol lowing the engine failure the pilot was able to maintain straight and level
flight. A cleared area of ground lay ahead and just to the left of the flight path but the pilot had considered the aircraft had sufficient
performance capability to permit a return to the strip.
01 Dec 84
Victa 100 VH-BNV
Commercial
8421070
1130 .
Chillingham 20N
58
22000
9000
Flight instructor grade 1 or 2
The pilot had recently purchased the aircraft and intended taking it to his local aerodrome. About 20 minutes after departure the engine
sudden ly lost all power and the pilot was committed to a landing on unsuitable terrain. On landing the nose and left main wheels were torn
off and the left wing main spar was broken. When inspecting the aircraft after it had come to rest, the pilot discovered a loose connection
in the fuel line on the inlet side of the fuel fi lter bowl.
The aircraft had stood disused at ~he departure ALA for about two years and the pilot conducted a detailed pre-flight inspection and a
test. flight before departure. T~e ma1nten.ance re.lease was not readi ly available prior to departure, but its inspection subsequent to the
accident indicated that no maintenance inspections had been conducted on the aircraft during the previous 27 months.
02 Dec 84
Ayers S2R VH-JBN
Commercial
8421071
0256
Mungindi NSW
53
17817
25
Agricultural class 1
At .the conc lusion of night spraying operations the pilot departed for Mungindi. Witnesses at the town saw the aircraft overflying at a low
height and heading towards the aerodrome, wh ich is about 7 kilometres from the town. Engine noise was then heard to cease and sounds
of impact followed. The aircraf! had str~ck the gr~und 5 kilometres from the aerodrome, and a post-impact fire had engulfed the wreckage.
. ~o fault could be found with the aircraft or its systems that could have contributed to the accident. Specialist medical opinion,
indicated that the pilot ha? suffere.d a heart attack before the fire occurred. It was not possi ble to determine to what extent, if any, the pilot
was able to control the aircraft pnor to impact.
16 Dec 84
Glasflugel Kestrel VH-GSY
Glider
8421072
1445
Pipers Field NSW
59
58
None
The pilot was appro~ching t~ land at the conclusion of his second flig~t on the type. The approach was normal, however the glider floated
!he.l~ngth o! the stnp at a height of a.bout 25 feet. At the end of the stnp a turn was commenced but after completing about 90 degrees an
inc1p1ent spin developed and the glider struck the ground. The pilot subsequently advised that he had activated the cruise flap lever
instead of the air brake. The two levers are located side by side in the cockpit.
It is likely that the pilot was suffering a degree of heat stress. He had been in the cockpit, exposed to the sun for two and a half hours
and he had not eaten since breakfast. He reported that during the final stages of flight his reactions were affected by fatigue and the heat.
24 Jan 85
Socata 8808 VH-UQG
Private
8521005
0947
Wellington NSW
56
997
792
None
The pilot had diverted to Wellington because of thick bushfire smoke on his intended track. Take-off was initiated after the smoke had
c lea.red, however sh?rtly after becoming airborne the aircraft sank towards the ground. The pilot subsequently advised that although the
engine was developing fu ll power he was unable to prevent the sink from continuing until the aircraft struck the ground heavily 210
metres beyond the boundary fence of the strip.
'
The 05 strip was. used for take·off into a north-easterly breeze. However a witness about 2 kilometres away, along the take-off path,
repo~ed that the wind ther~ w~s from the south. It 1s likely that at about 200 feet agl the aircraft experienced a head to tai l wi nd change.
The pilot attempted to regain airspeed by lowering the nose but the low altitude and rising ground ahead prevented sufficient airspeed to
be recovered.
viii I Aviation Safety Digest 127
03 Mar 85
Cessna 172N VH-TSQ
Private rest ricted
8~31009
0830
Falmouth Tas
18
50
50
None
The pilot intended to conduct practice circuits and landings in preparation for competiti ons later in the day. On the first landing
the aircraft bounced slightly and then veered Into soft earth at the edge of the partially constructed strip . The nose gear leg
collapsed and the left wing tip struck rocks adjacent to the strip.
The pilot was inexperienced and the landing was conducted in crosswind conditions onto a 15 metre wide section of strip
which was closely surrounded by areas of soft gro und, rocks and earthworks. The organisers of the flying competition had
permitted operat ions to take place on a sub-standard strip.
04 Mar 85
Robinson R22 VH-UXT
Commercial - heli copter
8521015
1327
Camden NSW
41
4950
28
No ne
As the final sequence of a licence test flight the examiner requested the pilot to carry out a normal autorotative landing from
circuit height. The aircraft was f lared slightly high, recovered but subsequently contacted the ground in a tai l low attitude. It then
boun ced forward and the tail boom was severed by the main rotor.
The aircraft flight manual specifies that touchdown following an autorotative descent mu st be made w ith the landing skids
level. On this occas ion touchdown was made on the heels of the skids, and the resulting oscillations of the aircraft allowed the
main rotor blades to sai l and strike the tail boo m.
05 Mar 85
Cessna 172A VH -DZA
Private
8551005
1900
Nullagine WA
42
225
150
None
The pi lot planned to arrive at his dest ination 10 minutes before his estimate of last light. However, deviating around rain showers
and conducting an aerial inspection of a prospect ing site, the pilot's arrival was delayed until 10 minutes after last light. An
approach was made to the unlit strip using the aircraft landing light for guidance. After flaring at about 15 feet agl the pilot waited
for touchdown but the aircraft stalled and struck the ground nosewheel first, collapsing the nose gear.
Facilities were available at the departure aerodrome wh ich would have allowed the pilot t o obtain a weather forecast and an
accurate time of last light. Despite the fact that the pilot had no night flying experience he choose to land the aircraft without
requesting an emergency flare path to be laid.
05 Mar 85
Cessna 172G VH-P LX
Commercial
8511010
1500
Windorah 85SSW
25
307
Instrument rating class 4
The pilot who was inexperienced in mustering operations was impressed w ith the efficiency of the other members of the
mu stering team. So as not to be seen to be wastin g time, the pil ot elected to land downwind on the s horter strip in stead of
clearing cattle from the main strip. However, he did not notice a washou t cross ing the shorter st rip. During the landing roll the
aircraft entered the washout and the nosegear leg was broken off, the propell er, engine cowling and right wing were also
damaged.
15 Mar 85
Cessna 172M VH-RXN
Private
8521018
1000
Pt Macquarie 75W
53
1200
50
None
Prior to departure the pilot checked the fuel quantity using a graduated dipstick, marked in litres and gallon s. He noted that there
was apparently sufficient fuel for the proposed flight. About 75 minutes after take-off and whi le cruisi ng at 4500 feet amsl the
engine lost all power. The pi lot was committed to a forced landing in a rugged, heavily timbered area. The landing gear was
sheared off on touchdown and deceleration forces were severe. Subsequent investigation revealed that the engine failed from
fuel exhaustion.
The pilot had not flown t his particul ar ai rc raft before and was unfamiliar with the dipstick graduations. He misinterpreted the
quantity indicated on the dipstick litres scale as gallons and whilst dipping the tanks his eye level was such that he could not see
the fuel level within the tanks. During the flight the pilot had placed little reliance on fuel gauge indi cat ions.
23 Mar 85
Bell 206-B VH-KXV
Commercial - helicopter
8551006
1221
Karratha WA
39
6400
360
Instrument rat ing class 4
The pi lot deposited the sling load of deli cate instruments on the ground. To avoid dropping the shackle on the load, and becau se
of the proximity of a hangar to the left, he moved the helicopter to the right. The movement, together with type of shackle used
and the design of the hook, resulted in t he load not being released.
Prior to the flight the pilot had not insisted on the fitment of external load observation mirrors. While leaning out of the
helicopter to check that the load had been released, he inadvertently caused the helicopter to move further to the right. The
resulting tension on the cable connecting the hook and the load induced dynami c rollover. The pil ot attemp ted unsuccessfully to
correct the roll and during the s ubsequent landing the main rotor struck the ground. Use was not made of an available and
qualified marshaller.
27 Mar 85
Bell 47-G5 VH-DUS
Commercial - helicopter
851101 5
1430
Boo marra Sin Old
48
15000
11000
None
While hovering over scrub at about 30 feet agl, the engine lost power. The pilot was able to manoeuvre the aircraft to overhead a
clearing but rotor rpm decayed and the aircraft landed heavily bending the landing gear rear c ross tube and a sectio n of the tail
boom. The power loss resulted from the incorrect fitment of rocker arms during a previous servicing.
31 Mar 85
Cessna 182E VH-DBT
Private
8531 016
1344
Kyneton Vic
38
800
600
Instrum ent rating class 4
Four experienced parachutists intended to carry out a group descent from 5000 feet ag l. To facilitate the procedure, all four were
to exit the cab in and hold onto the aircraft structure before releas ing at the appropriate moment. As the second parachuti st
moved to take up his position, facing rearward s and sitting in the Vee of the wing strut, hi s parachute pack evidently snagged on
t he door open ing, and the parachute deployed. The lines passed arou nd the lift st rut and under the gear leg. The parachutist was
pulled off his seat but managed to throw hi s arms back and around the strut. The pilot felt the aircraft slow dramati cally as the
parachute opened, and he appli ed full forward movement of the control cc;>lumn. One of the other parac hutist s activivated the cut
away o n th e deployed parachute and assisted the parachutist to return to the cabin. The aircraft lost 3200 feet of altitude during
t he occurrence.
During the descent to land it was noticed that the wing strut was f lexing. After landing it was foun d t hat the strut was part ly
f ractu red. Had it fai led in flight the wi ng wou ld have been free to pivot upwards, with consequen t loss of ai rcraft co ntrol.
Aviation Safety Digest 127I ix
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
07 Apr 85
Robinson R22 VH-F HK
Commerc ial - helicopter
8511016
1240
Pnt Lookout Old
26
756
566
None
Because of obstructions around the intended landing area, the pilot carried out a downwind approach. As the pi lot reduced the speed
of the helicopter for landing it was caught by a sudden gust of wind. The helicopter sank, struck the ground and bounced before
landing on the left skid which entered a depression in the ground, resulting in the helicopter rolling over.
09 May 85
Beech D55 VH-KNE
Commercial
8551011
1605
Dalwallinu WA
56
5216
3560
Instrument rat ing Clii!SS 4
The aircraft was landed at the destination strip with the gear up.
No fau lt was found with the aircraft or its systems that cou ld have contributed to the accident. The pilot reported that he carried out
the downwind and pre-landing checks, both of which included a gear check, but he could not explain why he did not lower the gear.
12 Apr 85
Piper 25-235 VH-TPE
Commercial
8511017
1725
Mareeba Old 7SE
32
5180
Agricultural class 1
150
During the pull up at the end of a downwind spray run, the right wing struck a tree. The aircraft was landed without further damage at a
nearby aerodrome.
On inspection of the area to be sprayed, the pilot selected a pull-up point. He stated that when that point was reached on the spray
run, he closed the spray handle before initiating the pull-up and thus delayed the pull-up. After landing the pilot also found that the
wind strength was greater than he had originally est imated.
15 May 85
Piper 32-R300 VH-PNB
Private
8511 019
1335
Babinda Old 5W
55
2000
1200
Instrument rat ing c lass 4
The pilot received a weather briefing before departing Townsville which indicated that the weather enroute was unsuitable for visual
flig ht. After being issued with a clearance to enter Cairns control zone no further transmissions were received from the aircraft and it
failed to arrive at Cairns. The wreckage of the aircraft was located in rain forest on the lower southern slopes of the south peak of the
Bellenden Ker Range. The weather in the area at the time was reported as low cloud with heavy rain. The pilot was not qualif ied for
flight in other t han visual meteorological conditions.
Investigation revealed that the aircraft was serviceable prior to impact. Witnesses reported that they observed the airc raft passing
in and out of the c loud base, which was at about 800 feet. They saw the aircraft tracking in a nort hwesterly d irection towards high
ground which rose to 4000 feet amsl. The wreckage was discovered at an elevation of 680 feet ams l. The pilot was known to have
urgent business commitments and this may have influenced his decision to continue the flight in unsuitable weather conditions.
14 Apr 85
Cessna 404 VH-LAD
Senior commercial
8541008
1008
Moomba SA 55NW
30
5300
400
Instrument rat ing class 4
During the landing roll the aircraft suddenly veered to the left. The pilot took correct ive action but the nose gear collapsed and the nose
section of the aircraft struck the strip surface.
Although the strip was in reg ular use it was not being inspected. It was constructed on a dry lake-bed and the combination of no rain
and regular use caused a soft patch to develop about 430 metres from the threshold. When the aircraft entered this area the nosewheel
progressively turned left until it reached the stop. The sideload now imposed was too great and caused the noseleg bearing to fail.
18 Apr 85
1100
Cessna R182 VH-SMV
Maitland NSW
Senior commerc ial
8521030
100
Instrument rat ing 1st class or
c lass 1
The pilot decided to carry out a circuit in order to check the performance of the eng ine. Because of the presence of a gusting 20 knot
westerly wind, a higher than normal approach speed was flown. The pilot stated that he closed the throttle at about 50 feet agl and
flared the aircraft. The subsequent landing was heavy, the aircraft bounced, t he pilot moved the control column forward and the
aircraft bounced a second time. On the t hird touch down the pilot reported that the tai l struck the runway causing substantial damage
to the tail area of the aircraft.
26
2700
20 Apr 85
Piper 32-300 VH-MAR
Commerc ial
8541009
1343
Darwin NT
19
258
100
Instrument rat ing class 4
After landing the aircraft was taxiied along a taxiway to the general aviat ion parking area. In preparation for a 90 degree turn in the
taxiway the pilot moved the aircraft to the right of the taxiway. The nose wheel struck a steel gable marker, wh ich was positioned 500
millimetres off to t he right of the taxiway. As a result of the collision the nose gear col lapsed.
The pilot was not concentrating sufficiently on the taxying of the aircraft, which was bei ng operated at a high speed.
01 May 85
Beech 95-A55 VH-FDP
Private
8551010
1720
Busselton WA
52
2700
1100
None
During the circuit, the pilot and passenger were discussin g f ires near their property. The aircraft was subsequent ly landed with the
gear up.
The gear and its warning systems were serviceable. The pil ot's atten tion was diverted from the operation of the aircraft by the fires and
the pre-landing c hecks were not correctly completed.
02 May 85
Hughes 269-C VH-RIK
Commercial - helicopter
8541010
1430
Balbirini Sin NT
20
876
649
Instrument rating class 4
The pilot was attempting to move a cow back into the mob. He brought the helicopter to a low hover close to the animal. The animal
spun around, reared up and caught its horns on the helicopter skids. The helicopter pitched forward and struck the ground.
The pilot was inexperienced in mustering operat ions and was not provided with adequate continuat ion training or supervision by
the operator.
Senior commercial
8521026
28
5500
350
Instrument rat ing 1st c lass or
class 1
The pilot elected to conduct the flight at a very low height above the ground. The aircraft col lided with power lines, whi ch severed the
top 10 centimetres of the rudder. Cont rol of the aircraft was maintained and a safe landing was made at the intended destination.
03 May 85
1640
Piper 30 VH-TOD
Hay NSW 24EN E
04 May 85
Cessna U206 VH-POT
Commercial
8531015
1745
Kempsey NSW
30
361
26
Instrument rating class 4
The aircraft initially touched down about halfway along the st rip, became airborne again, then touched down 50 metres before t he end
of the strip. The pilot applied power to go-around. However after reassessing the s it uation, he c losed the throttle and attempted to
steer the aircraft through a gate. The nose wheel dug into the ground and the aircraft tilted forward onto the propell er and left wing. The
propel ler spinner struck the gate and the aircraft stopped.
The approach had been conducted in conditions of reduced visibi lity as a result of cloud cover and impending last light. The pilot
had misjudged the approach and had used a higher t han normal airspeed. The lack of visual cues evidently caused the pilot to delay
initiating a go-around while such a manoeuvre could still have been safely accompl ished.
06 May 85
Piper 34-200T VH-ADO
Private
8521027
1830
Kempsey NSW
41
249
151
Instrument rating class 4
The pilot reported that the aircraft was flared normally for the night landing, but it dropped suddenly and struck the runway heavily.
Damage was caused to the nose gear strut. The pilot, believing he was los ing control of the aircraft , carried out ago-around. During the
subsequent landing, the pilot was unable to steer the aircraft which veered to the left and struck a cone marker before being brought to
a stop.
The aircraft had been observed to fly a close base leg followed by a steep final approach path. The pilot had misjudged the landing
flare and during the subsequent heavy landing the nose gear strut was pushed upward through the aircraft nose, dislodging the
windscreen and disconnecti ng the nose whee l steering. Unknown to the pilot, the prope llers also contacted t he runway and the ti ps of
all blades had been bent.
x I Aviation Safety Digest 127
18 May 85
1305
8511 020
Instrument rating 1st c lass or
class 1 with instrument rating
After the pilot selected the gear down , he observed t hat the single gear posit ion indicator light indicated that the gear was down.
During the landing roll, as t he aircraft slowed down, the left wi ngtip and left propeller contacted the strip. Subsequent inspect ion of
the aircraft revealed that the left main gear was in the up position .
The left gear uplock bracket-block had recently been repaired but the forward hole had been drilled slightly off centre. This caused
the bracket to tilt rearward and the block to slip off the uplock ro ller face and jam against the ro ller retaining bolt. When the gear was
selected down the gear motor drove against the jammed uplock and bent t he left retract rod. This allowed the motor to complete its
extension cycle and indicate a gear down condition because the ind icator switches are located on the activator housing and not at
each gear leg.
Beech D55 VH-1LM
Brampton Island
42
13000
Commerc ial
1200
18 May 85
Cessna 172F VH-DNV
Private
8521031
1505
Nth Curl Curl Bch
23
126
40
None
The aircraft was cru ising at 500 feet above some Sydney area beaches. Following an ATC instruction, the pi lot appl ied ful l power in
order to climb to 2000 feet. The engine ran roughly for a short period t hen lost all power and the pilot was committed to a forced
landi ng in shallow water. Touchdown occurred about 5 metres f rom the shore-line and the aircraft came to rest inverted in the water.
No pre-existing fault could be found with the aircraft eng ine or ancillaries. Atmospheric conditions were conducive to the
formation of moderate carburettor icing. Carburettor heat had not been applied when the engine began to run roughly and lose
power.
22 May 85
Piper 28-161 VH-IJK
Private
8521033
2015
Goulburn NSW
57
578
381
Instrument rating c lass 4
The pi lot was conducting a night cross-country exercise to maintain his recent experience requirements. On final approach he
realised that the aircraft was undershooting. Some engine power was applied and the approach was continued but the pilot then saw
power lines ahead, too late to take any avoiding action. The ai rcraft struck the wires and subsequent ly impacted the ground 21 1
metres short of the thresho ld. It came to rest 91 metres f urther on after colliding with a fence. The wires struck provided power for
the airfield lighting, which was ext ingu ished at the time of collision.
The power li nes struck were 28 feet agl and were 600 metres from the threshold. The pilot had been slow to realise that the
undershoot s ituation was developing and had not taken appropriate action to either regain the normal approach path or to goaround.
27 May 85
Bell 47-G5 VH-AEO
Commercial - helicopter
8511020
1030
Strathmore Sin
30
5100
4500
None
While flying at a s low forward speed approx imately 15 feet above the trees, the helicopter sudden ly yawed to the right. As the pi lot was
unable to correct the yaw he attempted to manoeuvre the helicopter to a c lear area. The helicopter impacted the ground in a level
attitude, heading rearward and rotating .
Investigation revealed that all the teeth were m issing from the forward short shaft rear coupling, which had failed due to lack of
lu brication, and resulted in a loss of tail rotor propu ls ion. The coupl ing, wh ich was covered by a rubber dust boot, had not received
adequate daily inspections to ensure that it contained sufficient grease and was free of excessive play.
30 May 85
Cessna 182H VH-PLF
Private restricted
8511022
1030
Roma Old
49
115
75
None
The pilot reported that he had made a good approach, but had flared high. The aircraft landed heavil y on the mainwheels then
nosewheel. Buckling of the f irewall and undersurface of the fuselage was discovered after the aircraft had been shut down in the
parking area.
Du ring his training, prior to the accident, the pilot had displayed inconsistent f ly ing standards in the landing phase. At times he had
misj udged altitude, airspeed and flare. The airspeed indicator was also found to be overreading by five knots at threshold speeds and
th is reduced margin above the aircraft stal l speed is likely to have increased the pilot's handlin g difficu lties.
09 Jun 85
Grumman 164 VH-CCT
Commercial
8511024
1300
Gayndah Old 30NW
43
8000
6500
Agricultural c lass 1
On the pull-up at the end of the first spray run in that particu lar direction, the aircraft struck a single wire power line. The pi lot
immediately landed the aircraft in a clear area. Du ring the landing roll the right wheel struck a large rock, wh ich was concealed in long
grass, and the right maingear was torn off. The aircraft pitched forward onto the engine and came to rest in a near vert ical attitude.
Before he commenced treatment of the area, the pilot surveyed it from the air and questioned the owner on the whereabouts of any
obstruct ions. However, he did not check the area from the ground. Although he had been told of the presence of the wire, it was furt her
from the paddock and higher above the ground than he had expected. The span between po les on the section of wire struck by the
aircraft was 540 metres.
Aviation Safe ty Digest 127I xi
�De.le
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
09 Jun 85
Glasflugel Mosquito VH-GSZ
Glider
8531017
1230
Horsham Vic 36SSE
30
508
250
Glider
During ridge soaring operations, areas of sink were encountered and the aircraft descended over forested terrain. The only area
suitable for an outlanding was a small deer enclosure. The pilot initially overshot the area and during the turn to reposition the
aircraft for landing the right wing struck the fence surrounding the enclosure. The aircraft yawed through 90 degrees before
impacting the ground in a level attitude.
Although general soaring conditions were poor, the pilot had elected to leave the ridge-line to conduct a sight-seeing flight.
During this flight a wind change moved through the area. On return to the ridge-li ne the pi lot, who had not detected the wind
change, persisted with efforts to find an area of lift. The proximity of the aircraft to the tops of the trees and the small size of the
deer enclosure precluded the pi lot sighting the clearing in time to conduct a straight-in approach.
19 Jun 85
Piper 32-300 VH-WSZ
Pr ivate
8541011
1053
American Rvr Sth
38
835
282
Instrument rating c lass 4
The pilot established the aircraft on final approach at 80 knots wit h full flap selected. She allowed the airspeed to reduce to 70
knots as the aircraft crossed the boundary fence. The aircraft impacted the ground heavi ly, nosewheel first, from about 15 feet
agl. The main landing-gear was dislodged and the nose-gear folded backwards.
As there were sheep on the upwind end of the strip, the pilot decided to use the short landing technique but the flare height
was misjudged. When sink was encountered, full up-elevator was applied but engine power was not increased as part of the
recovery action. It was likely that the aircraft encountered undershoot windshear conditions on short final.
In brief In brief In brief In brief
,
While in the cruise, nine inches of one propeller blade of
a P A32 broke off. The blade separation caused severe
vibration, which in turn necessitated an immediate
forced landing. The aircraft was substantially damaged
during the landing roll, although none of its three
occupants was injured.
Investigation revealed that the propeller tip separated
because of high cycle fatigue at a nick on the prop's
leading edge. The nick had previously been filed down.
21 Jun 85
Piper 38-112 VH-MHO
Student
8541012
1630
Parafield SA
28
27
27
None
The pilot was returning from a period in the local training area. Another aircraft was also returning and was advised that it would
be number 2 in the landing sequence. However, the pilot of this aircraft overtook VH-MHO on the downwind leg. On final
approach it was considered that insufficient separation would exist for landing, and the pilot of VH-MHO was offered the use of
the parallel runway. Because the threshold of this runway was 250 metres closer than the planned runway, the pilot carried out a
steeper than normal approach. The aircraft landed heavily nosewheel first and bounced. The pilot recovered the situation and relanded smoothly, but the firewall and nosegear assembly had been damaged.
The pilot had probably been confused when the aircraft which was supposed to be fo llow ing appeared ahead in the landing
sequence, and he was offered a late change of runway. The steep approach had led to a misjudgment of the flare. The instructor
in the other craft, after acknowledg ing an instruction to position as number 2, and advising that he had the preceding aircraft in
sight, did not maintain the required sequence.
*
.. .
27 Jun 85
Cessna 172N VH-WHK
Private
8511029
0930
Cape Keer Weer
44
448
348
None
The pilot stated that just after the aircraft became airborne it encountered a strong gust of wind. The left wing tip and nosewheel
struck the ground and the aircraft overturned.
During the take-off run the pilot held back pressure on the control column and at 50 knots selected 10 degrees of flap, the
aircraft becoming airborne after a ground roll of only 170 metres. The take-off distance required was 650 metres, however, the
take-off was attempted on an unprepared salt pan with an available take-off distance of 300 metres. The pilot had operated from
this area previously but on this occasion the aircraft was at a higher all up weight. The wind gust reported by the pilot was
probably associated with a willy willy, encountered when the aircraft was at a low airspeed.
27 Jun 85
De Hav C2 VH-AAY
Commercial
8521040
0630
Walcha NSW 3NW
27
1200
300
Agricultural class 2
The aircraft had been parked in the open overnight. When the pilot arrived at the strip, he noted that shallow fog had settled over
the area. The temperature was below freezing point and frost covered the aircraft, except for the windscreen which had been
protected by a cloth sheet. A pre-flight inspecti on was carried out, but did not include the removal of the frost from the aircraft.
Because the fog had reduced visibility to about 50 metres, the pilot taxied the aircraft along the strip to check for obstructions.
During this time the moisture froze on the windscreen, however by reaching from the cockpit the pilot was able to clear the left
side of the screen.
Shortly afterwards the take-off was commenced and the lightly loaded aircraft became airborne after a ground run of about 250
metres. At this point all forward visibility was lost because of frost re-forming on the windscreen. The pi lot noticed that the
aircraft appeared to be banking to the left and he elected to land immediately. The left wingtip contacted the ground, followed by
the main wheels. The aircraft ran off the side of the strip and collided with a fence, before coming to rest about 100 metres from
the strip.
The pilot had had no disciplined instrument flying experience and had been unable to maintain effective control of the aircraft
during the take-off with severely restricted visibility. The degradation in aircraft performance as a result of the frost covering the
wings and tail surfaces could not be established.
28 Jun 85
1951
Smith 600 VH-IGV
Bankstown NSW
8521041
Instrument rating 1st class or
class 1
The landing gear was selected down during the downwind leg of the circuit, and the gear down lights were illuminated. The
aircraft touched down normally, but as soon as the nosewheel contacted the runway, the gear warning horn sounded and the
nose-gear retracted. The aircraft slid to a halt on the centre-line of the runway.
Inspection confirmed that the landing gear system was serviceable. However, the cause of the gear col lapse was not pos iti vely
determined.
xii / Aviation Safety Digest 12 7
43
1000
Commercial
500
controls. Good instructors try to keep such interference to
a minimum and prefer to talk a student through an
exercise or problem. Perhaps on this occasion it should
have been apparent to the instructor that the student was
not responding normally to his 'go around' command a term commonly used by most pilots and air traffic
controllers. Some prefer 'overshoot' or 'make missed
approach'. Whatever term is used , someone has to apply
power promptly. If the student won't, then the instructor
must.
*
*
*
A student pilot was undergoing a dual revision flight
prior to a flight test for his Private Pilot Licence. After
half an hour of air work he manoeuvred the Cessna 152
for a simulated forced landing in the low flying area.
The student missed the selected paddock so height was
regained for another attempt. This time the instructor
told the student to 'go around' at about 50 ft AGL. He
took no other action.
Two further calls to apply power were made by the
instructor, by which time the aircraft was about ten feet
off the ground before the student responded. However,
he allowed the nose to drop, and, before the instructor
could correct this the aircraft touched down on the soft,
peat surface. Rapid deceleration brought the Cessna to a
halt in about 30 metres.
It is often very difficult for an instructor to decide just
how far to let a student go before laying hands on the
*
*
A Citation II business jet took off from an overseas
airport on a rushed !FR departure in poor weather. The
ceiling was 100 feet and visibility three quarters of a mile
in fog. The aircraft crashed less than two miles from the
runway, impacting in a 90 degree banked attitude. T he
pilot, who was president of the company that owned the
aircraft, and his two passengers were killed.
The takeoff was commenced only about two minutes
after the pilot had started the engines, and soon after
leaving the ground he apparently lost control of the
aircraft - partly because his main attitude and heading
instruments had not 'spun up' to their proper functioning
speed.
The pilot held a Private Pilot Licence and Citation
type ratings, and had about 1750 hours on type. He had
arrived at the airport between 0920 and 0925 hours,
loaded the passengers and baggage, started the engines
and had taken off by 0930 hours - his planned
departure time.
The gyros in both the flight director (the pilot's main
attitude reference) and the HSI required three minutes to
spin up to their correct operating speeds. The pilot took
less than five minutes to perform all the preflight, startup, taxi and takeoff checks. Not surprisingly, the
investigators believed that he could not have completed
all the required items, including avionics and auto-pilot
checks, in two minutes. An auto-pilot check itself could
easily need at least 30 seconds, calling for proper flight
director operation.
It was concluded that the pilot probably began the
takeoff using his own attitude director indicator and the
co-pilot's HSI. This would have disrupted the normal
instrument scan pattern and helped towards
disorientation and loss of control.
The investigators commented, 'This accident is a
salutary reminder about the hazards of "kicking the tyres
and lighting the fires", and trea ting any aircraft in an
easy-going manner' .
*
*
*
Aviation Safety Digest 12 7I 13
�T he First Officer was flying an F27 on a VMC
approach at an overseas location. T he Captain
assessed the approach as being too low on final , but
allowed the approach to continue wit hout taking any
corrective action. T he aircraft landed hard in the
undersh oot area, 38 metres before the runway
threshold. It also struck an approach light (0.5 metres
high) which caused a tear in the fuselage .
The hard landing was no t rep orted and was only
discovered three days later.
*
*
*
During the preflight I checked the fuel gauges, which
both indicated barely above EMPTY. I then checked the
log against the tachometer time and noted that 0.9 hours
offlying time had elapsed since adding 10.5 gallons of
fuel. Sz'nce the average fuel consumption for this plane is
5 gallons/hour, I felt reasonably assured that I had one
hour's fuel left in the tanks - enough for the proposed
short flight ... I took off and at about 300 feet altitude
the engine started to run rough, but the application of
carburettor heat seemed to cure the problem, and we
continued to climb out. The engine then seemed to
develop icing repeatedly . . . although the outside
conditions were not what I normally expect to be
conducive to icing .. . At 5000 feet the engine power
died completely, so we glided back to the airport,
making a safe landing and coasting up to the fuel
pumps. I checked both fuel tanks and got not one drop
offuel from either . .. Probable cause: fuel stolen from
airplane since last use . . . Prevention - thorough
preflight inspection.
Shortly after takeoff an oil leak was noticed on the
inboard side of the star board engine of a Piper
Seneca. T h e oil flow appeared to be increasing and
was sufficient to cause the pilot to terminate the flight
and return to the departure base. After landing the
engine cowl was removed and a sma ll sp anner was
found lying on top of the oil cooler. It seems that the
sp anner had been in the engine compartment since
the last 100 hour inspection (16 flig ht hours
previously): d uring tha t time it had apparently been
bouncing on the oil cpoler, eventually causing it to
split and leak.
*
*
1 4 I Aviation Safety Digest 1 2 7
*
*
An inexperienced private pilot , who had just completed a
Cessna 172 endorsement , was carrying out circuit
practice with a passenger on board.
The first two circuits were carried out normally, but
on the third approach at 65 knots and with 20 ° of flap
selected, when the flare was initiated the aircraft
ballooned slightly. The Cessna bounced, so the control
column was held back, but a second bounce occurred so
the pilot applied power for a go-around. Unfortunately,
the application of power was too late, and as the
nosewheel tyre struck the ground it burst. The pilot and
passenger escaped injury but the aircraft was
substantially damaged.
Comment
When approaching to land at an airstrip or aerodrome,
pilots must be prepared to make a go-around if there
is the slightest doubt that the landing will not be safe. It
costs much less to go around and make another approach
than it does to repair a damaged aircraft - or pilot.
For those who always 'grease 'em on', but wish to
refresh their memories just in case, recovering from
bounced landings was discussed in A viation Safety Digest
117.
A p ilot h ad recently completed his tailwheel aircraft
endorsement a nd was car rying out solo practice . On the
first circuit t he aircraft touched down before the runway
threshold and ground looped to the right. The left main
gear leg collap sed and the aircraft tipped onto its left
wing and the nose before coming to rest.
During the approach the pilot's attention had been
diverted to another aircraft which had turned onto final
in front of his own. To avoid a go-around the pilot
reduced airspeed and continued to concentrate his
attention on the preceding aircraft. In doing so he
misjudged the approach and was unable to maintain
directional control after touchdown .
From the South China Morning Post, Hong Kong:
*
During th e preflight weather briefing the pilot was
advised that thunderstorms were active near his
destination. He nevertheless decided to press on with his
two-hour, VFR navex.
After flying over adverse weather for most of the trip
and overflying a suitable diversion airport, he continued
in weat her conditions which necessit ated track and
altitude devia tions to remain in VMC. About one and a
half hours after takeoff, both radios and one NAV/ COM
set in the PA28 became inoperative. A short time later
the pilot noticed wh at he thought was an airstrip, and
finally decided rhat it was time to terminate the flight.
The landing area in fact turned out to be a drag strip,
which h ad numerous obstructions. While the pilot was
manoeuvring to avoid th ose obstructions, the Warrior's
left wing struck a 4-foot high pole, causing substantial
damage to the aircraft and injury to its occupants.
*
*
T wo Civil Aviation Departm ent staff were slightly injured when
their car plunged into the h arbou r from th e airport runway last
night. The driver and his assistant were discharged after
treatment at Q ueen Elizabeth H ospital.
T he accident happened sh ortly after 8.30 p.m. when the
vehicle, a friction -tester, ran ou t of control at the end of the
runway.
-----~
*
*
*
*
*
*
*
*
*
During the day the members of a microlight flying
club in New Zealand had flown a Teratorn aircraft
on several occasions. H owever, on a subsequent flight ,
at a height of a about 25 feet AGL a loud 'crack' was
heard and a complete loss of engine power occurred .
Insufficient height and speed were available for the
pilot to flare the aircraft successfully so it was landed
in a nose-down attitude. The undercarriage structure
collapsed on impact and a failure of the structure
which supported the engine caused it to strike the
pilot on the head.
The pilot's head was protected by a full -face motor
cycle helmet and he escaped injury.
A subsequent tear-down examin ation of the engine
disclosed that the engine failure was probably caused
by faulty wiring to the ignition cut -out switd •
Aviation Safety Digest 12 7/ 15
�Just as the gun is always loaded ...
: A timely diversion
Despite the desperate attempts of the pilot and
passengers to stop the Cessna (attempts which in
themselves seem to have involved considerable danger to
those concerned), the aircraft eventually ran into a
drainage ditch and was substantially damaged.
Investigation
Post-accident examination of the cockpit showed that :
• the throttle was open about three -quarters of an inch
• the mixture was off the idle cutoff stop by about onesixteenth of an inch
• the park brake was only partially on
A continuity check of the ignition switch leads through
the ignition switch revealed that the right magneto was
intermittently 'live' with the ignition switch in the OFF
position. There would have been no way of knowing that
the right magneto was 'live' without starting the Cessna's
engine and carrying out a 'dead' magneto check.
An early arrival was made at the GAAP airport to carry
out the daily inspection on a Cessna 1 72 prior to a
planned pleasure flight with two passengers. The pilot
reported that during the internal inspection h e checked,
among other items, the throttle and mixture controls.
The check of those items was made visually, i.e. the pilot
did not physically operate them through their range nor
then set them to the recommended positions. He also
verified that the key had not been inserted in the
magneto/ start switch, and observed that the park brake
appeared to be on. He then removed the gust lock and
proceeded with the external inspection. Having finished
that, he returned to the cockpit and turned the master
switch on in order to retract the flaps. The master switch
was turned off and the pilot again confirmed that the
ignition key was not inserted (it was in fact stowed safely
in the Cessna's map compartment).
At this stage the pilot decided to check the
compressions of the engine. With the passengers standing
at the port wingtip as instructed, the pilot began to
handswing the propeller. On the fourth compression the
engine suddenly fired and started running.
The pilot ran to the door and looked for the ignition
key, intending to turn it off as a means of quickly
shutting down the engine: in the pressure of the moment
he had forgotten that he had observed the wise
precaution of not putting the key in the magneto/start
switch while completing his insp ection and while
handswinging the propeller. He then reached for the
mixture and throttle controls - but as he did so the
a ircraft began to move.
16 I Aviation Safety Digest 127
Conclusion
It would have been a sharp-eyed pilot who could have
seen that the throttle and mixture levers were not fully
closed, given the minute distances involved. Similarly,
the visual check of the park brake was inconclusive. A
physical check was necessary.
Because the engine controls were set to permit the
engine to run , and because of the live magneto, the
engine unexpectedly fired during the preflight inspection.
Before handswinging the propeller, the pilot had neither
ch ocked the Cl 72 nor set the park brake properly, while
there was not a suitably qualified person in the cockpit.
T hus , when the engine started, the aircraft ran out of
control and crashed into a ditch.
This occurrence illustrates the importance of the
quality of daily and preflight inspections - it's not
enough simply to 'do' them; they've got to be good. It
also confirms the adage that: 'Just as the gun is always
loaded, so the propeller is always alive'. Finally th e
accident provides a good reason for carrying out engine
'dead cut' ch ecks by turning the ignition switch/ es
momentarily to the OFF position at low RPM following an
engine run or just before shutting down •
Corrigendum
The a!ticle 'Ultralights and low-level turbulence' in
Digest 126 made the comment that stall speed
doubles in a level 60 degree bank turn. T hat of
course is incorrect: the article was intended to read
that the load factor doubles, and the stall speed
increases by about 40 per cent. Ultr alight pilots
would also be aware that at the time ASD 126 was
issued, no two-seat ultralights, as depicted in the
article's photograph, had been approved by the
Department of Aviation for flying training - the
particular photograph was reportedly taken during
authorised flight tests •
'A picture is worth a thousand words', or 'Every picture
tells a story' - take your choice of either of these
aphorisms. Each encapsulates the safety message
g raphically illustrated in the two photographs of a
timely diversion.
The Bonanza was carr ying the pilot and five
p assengers, and had departed on its flight in the
morning in clear weather . After one refuelling stop the
trip was continued. On this second leg a series o f
tropical storms was encountered. The pilot managed to
skirt around this weather until , when a bout 20 minutes
from the destin ation, and with the terrain becoming
rugged, the clouds started to close in and visibility
began to decrease.
In the in terests of safety, the p ilot elected to land
while he still had time on a nearby ALA.
The photographs tell the story - the first shows the
adverse weather confronting the Bonanza pilot, and the
second shows the aircraft a nd its occupants safely on
the ground after the right decision h ad been made a t
the right time •
Aviation Safety Digest 12 7I 17
�The residual effects of alcohol
The immediate effects of alcohol on an individual 's performance are generally well appreciated and are
apparent in the widespread social condemnation of drinking and driving. Perhaps less well understood are
the residual effects of alcohol - the degradation of performance which can still occur when the short-term
influence of alcohol consumption has dissipated.
Alcohol consumption
The alcohol yo u consume in beer and mixed drinks is
simple ethyl alcohol , a central n ervous system
depressant. From a medical point of view, it acts upon
your bod y much like a general anaesthe tic. The 'dose',
of course, is generally much lower and m ore slowl y
a bsorbed in the case of alcohol. But the basic effects on
your central nervous system are simila r .
You have undoubtedly heard time and time again
tha t alcohol is a depressant not a stimulant. Yet after
one or two drinks you certainly feel stimulated . This
sensation is misleading and occurs because pa rt of the
depressant action of alcohol , working on the brain,
bri ngs about a release from the usual psycho-social
restraints and inhibitions. You may enjoy a feeling of
security, well -being, confidence , and freedom from
pressure. In reality, however, your thinking has become
sluggish , you respond to urgent situations less efficiently,
a nd your a bility to perfo rm simple tasks with speed and
accuracy is diminished . If in addition you happen to be
tired , hungry, or under stress, these handicaps will be
com pounded .
T he effect of alcohol is greatly multiplied when a
person is exposed to altitude. T wo drinks on the ground
a re equivalent to three or four at altitude. The reason
for this is tha t akohol interferes with the a bility of the
br ain to utilise oxygen . And the effects are ra pid - first
because alcohol passes so quickly into the bloodstream ,
and second because the brain is a highly vascula r organ ,
immediate ly sensitive to changes in the blood's
composition . For the pilot, then, the lower oxygen
availability a t altitude, along with the lower ca pability of
his brain (under the influence of alcohol) to use what
oxygen is there, adds up to a deadly combination.
How long Is performance affected?
The approach to alcohol and flying by Australian pilots
generally seems very mature, and there are few recorded
examples of people trying to pilot an aircraft while
suffering from the immediate effects of alcohol.
However, wha t many pilots may not apprecia te is tha t
the deleterious consequences of drinking can adversely
affect performance for up to 48 hours. This was clearly
illustrated in a series of experimen ts conducted in the
United States, the results of which were reported in the
U.S. Army A viation Digest.
T ests were conducted in a flight simulator on
volunteers, using a blood level of 0 .08 per cent (which is
considered to be a safe level by some) . Almost without
exception the subjects exhibited very serious errors of
omission .
T hese errors, had the aircraft been real, frequently
would have resulted in fa tal mish aps, and a t least would
have resulted in placing the plane a nd its occupa nts in
potentia lly dangerous attitudes a nd situations. T he m ost
interesting finding overall was that the effects of the
18 I A viation Safety Digest 127
The deleterious effects of drinking can ad versely affect
performance for up to 48 hours.
The effects of alcohol may lead to disorientation and abnormal eye movements.
alcohol were greatest on those pilots who, on nonalcohol flights, had shown themselves to be the
smoot hest, best co-ordina ted , most flawless and coolest
under pressure. If they were relaxed when they mounted
the flight simulator, this condition was drastically
changed by the alcohol, and perfo rmance deteriorated
accordingly.
Behaviour such as dumping fuel , inadvertently putting
the landing gear down at high speeds , placing the
aircraft in irrecoverable attitudes, and attempting to land
at 10 780 feet rather than 780 feet (the local field
elevation) were but a few examples. So that these
findings could not be a ttributed to chance, the
experiments were repeated using different subjects, with
basically the same results.
A follow-on study then examined the effects of alcohol
on errors of omission, e.g. forgetting an important
function or overlooking an important detail. For this
study emphasis was placed on how accurately subjects
could follow a preflight checklist. Seventy-eight items
comprised the checklist which each subject took on every
flig ht . The task in this experiment was b asically the
same as that of any pilot : to begin with the first item
a nd, sequentially, perform each function listed
continuing systematically down the list until all items
h ad been completed.
Prior to all flights , the experimenters , without the
knowledge of the subjects, pre-set sever al errors:
• brakes O FF
• landing gear handle UP
• altimeter mis-set by 1000 feet
Close adher ence to the checklist should h ave caught
a ll of the pre-set errors. Each subject 'flew' two test
flights, one without alcohol and about 1 m onth late r one
with alcohol (0 .08 per cent blood alcohol level). The
results were as follows :
• Under the no-alcohol conditions, I 1 per cent of all
subjects failed to correct at least on e m ajor p re-set
error.
• Under the influnce of alcohol, 79 per cent of all
subjects failed to correct a t least one major error.
These pilots, it should be remembered, were
considered legally sober and capable of driving an
automobile in most States.
Most of the experiments were conducted in the la te
afternoon or early evening. It was noticed that some of
the subjects complained in class the following morning
that they still 'felt lousy' due to the previous day's flight.
A check of the literature showed that the amounts of
alcohol ingested essentially should have m etabolised
easily within 10 hours after drinking. In addition , from
perusal of airline publications and milita ry avia tion
journals it also was noted that the general rule of thumb
for social drinking recommended to pilots was to allow 8
to 12 hours between 'bottle and throttle'. It was thought
at that time that, although there was no longer any
detectable alcohol in the blood, hangover effects might
still produce a decrease in performance of complex tasks
such as the psychomotor responses required in flying . A
recent study followed this line of reasoning as tests were
commenced on the so -called 'hangover' or residual
effects of alcohol. The results a re presented in
a bbreviated form here.
The subjects already were familia r with preflight,
inflight, and postflight checklist responses and the basics
of flying prior to the experiment proper . A 6 inch by
9 inch card containing a deta iled checklist was given to
each subject and all subjects were told to adhere to it
religiously. This was followed by actual ' hands on'
simulated flight consisting of takeoff, climbout, levelling
a t altitude, and full-stop landings. When the subjects
reached the point where they could successfully handle
these fully checklisted 'flights' at least three times
consecutively without the slightest error , the experiment
proper was begun.
After this pre-training but before the first test flight
(non-alcoholic), the following errors were pre-set by the
experimenters:
• brakes were placed in the OFF position
• la nding gear h andle was put in the UP position
• fuel select switch was placed on auxiliary t anks
• wing flaps were set at 50 per cent
• altimeter was adjusted to 1000 feet a bove local
ground level.
At the preflight briefing, each subject was told to take
off, climb to 6000 feet, and m aintain that for 5 minutes.
When requested to do so , the subject was to prepare for
a landing and complete the landing a t his discretion.
The main data for the non-alcoholic flights consisted of
the number of pre-set errors each subject failed to
correct pi:ior to takeoff.
The only essential difference between the flights
described above and the second test flight (alcohol) was
that, 30 minutes before the alcohol flights, each subject
Aviation Safety Digest 127I 19
�Photographs courtesy of Mr Robert Mossel
was given enough 80 per cent vodka mixed with an
equal amount of ginger ale to attain a blood alcohol
level of 0. 10 per cent.
Finally, a third test flight was given 14 hours after the
alcohol flight.
The results were interesting to say the least. During
the first test flight (non -alcoholic), 10 per cent of all
subjects overlooked at least one of the major pre-set
errors. For the alcohol flight , 89 per cent of all subjects
made a t least one oversight error. Fourteen hours after
a lcohol intake , 68 per cent of all subjects still overlooked
at least one p re-set error! It is apparent that
performance 14 hours after alcohol intake was much
more like that 30 minutes after inta ke than that of the
first , non-alcohol flight.
This evidence suggests that a lthough most, if not all ,
of the alcohol had been processed through the body
during the 14 hours following intake , the residual effects
were contributing to this performance deterioration. All
pilots should be aware of this residual effect and should
rethink and possibly recalculate the margin of safety
implicit in the old rule of thumb , 8 to 12 hours between
'bottle and throttle'.
What are the causes of the residual effects?
1. One effect of alcohol consumption is a temporary
alteration of the fluid balance. Drinking dehydrates
your body by stimulating the kidneys to produce an
abnormal volume of diluted urine so that the body
loses more fluid than it takes in. This dehydration
produces a concentration of all the solutes normally
found in body fluids, and that alcohol-induced
chemical concentration causes weakness, fatigue and
irritability.
2. Another element in the making of a hangover is the
assortment of organic impurities found in all alcoholic
beverages. These aldehydes, ketones and other
substances are metabolised in complex ways and m ay
remain in the bloodstream long after the alcohol itself
is gone. As long as these substances are present they
produce untoward other side effects.
3 . Some of you may have noticed th at after a heavy
night's drinking you have, as they say, to wait for t he
bed to go past before you can jump onto it and that
things get even worse when you lie down. T hi's
happens because of the relationship between
vestibular (inner ear) stimulation and eye movements.
deflects skull
cupula thus
(cupula)
The semi-circula r inner ear canals are best
regarded as angular accelerometers. Each one is a
fluid-filled tube with a watertight swing door across
it. The fluid tries to stay still because of its inertia
20 / Aviation Safety Digest 12 7
and deflects the door one wa y or the other depending
on the direction of the head 's angular acceleration ,
whether produced by voluntary head movement or by
some external motion such as aircraft yaw, pitch or
roll. H ead movements detected by this system are
used to stabilise the visual world on the retipa by the
elicitation of eye movements , i.e. eye movements are
made to compensate for head movements in order
that the world does not appear to fly about on the
retina. You can check that this happens by nodding
while reading this - you should still be able to read
it . If however, you wave this journal up and down
instead of nodding, then you cannot read it.
In order for this system to work, the watertight
door must be unaffected by linear accelerations such
as gravity and, to be so unaffected, the door must
have the same specific gravity as the fluid . Alcohol in
this system disturbs this specific gravity balance. The
flap tends to float and the deflection is interpreted as
a head movement and a compensatory eye movement
is made. However, as no real head movement was
made, the eye movement is inappropriate and the
subject perceives the world to move. This effect
follows closely on the consump tion of alcohol and is
known as Positional Alcohol Nystagmus (Phase 1) or
PAN 1. As the fluid and flap come into alcoholic
imbalance, there then follows a phase when there is
an absence of abnormal eye movements, and this is
followed by a second phase of Positional Nystagmus.
The further phase ( PAN 2) is caused by an imbalance
of specific gravity between the fluid and the door as
the system loses alcohol. (Alcohol remains in this
system well after the b lood levels h ave become
negligible.) With increased g forces the imbalance is
effectively amplified.
T he upshot of all this is that the abnormal eye
movements that are evidence of vestibular p roblems
can be produced up to two days after drinking the
equivalent of only a cou ple of pints of beer if the
subject is exposed to two or three g , and this effect
can be demonstrated long after no alcohol can be
detected in the blood.
The precise significance as far as flying is
concerned is difficult to determine - but it can
safely be said that if you find yourself in an unusual
attitude being subjected to unusu al accelerations,
then the effects discussed above may well lead to you
becoming disoriented when you m ight otherwise not
have been and, once disoriented , will make it more
difficult for you to recover the situation.
Alcohol, even after it has been metabolised and
excreted from the b ody, as indicated by blood alcohol
levels , leaves its effect on your central nervous system for
a long time. The untoward effects of alcohol last very
much longer than most of us appreciate.
Conclusion
T he prevention of the short term and long term
(hangover) effects of alcohol is simple - don't drink.
The cure for a hangover also is sim ple - wait; and
before taking to the air you may need to wait 48 hours.
Remember - alcohol can kill •
Acknowledgments: FAA Medical Handbook for Pilots, U. S. Army
Aviation Digest, Air Clues.
Aviation Safety Digest 1271 21
�---- ---
--~ -~"'------,.~~----=-~-=-=,,,,,,---------
Spark plug fouling
A Cessna 152 was cruising at 2000 feet and 90 kts with
the engine set at 2300 rpm. The student pilot was
'under the hood' practising instrument flying when the
instructor noticed a flock of birds immediately in front
of the aircraft. He took the controls and rolled the
a ircraft to th e rig ht but several birds were believed to
have struck the aircraft in the vicinity of the engine
before it h ad commenced to turn.
Several minutes later the inst ru ctor noticed the oil
temperature needle was on the red line and the oil
pressure indication was on the 'bottom of the green'.
H e said he selected the mixture to full rich , reduced
the power to 2000 rpm and descended to 1800 feet.
After approximately 2 minutes no noticeable ch ange in
oil temperature or pressure was evident so the pilot
climbed the aircraft back to 2000 feet. After cruise
power was set the engine started to miss intermittently.
The instructor advised' Flight Service of the birdstrike
and the engine over-heat condition, and also that he
intended to track direct to his destination (a
GAAP aerodrome), about 8 minutes away from his
present position.
Shortly afterwards the engine began to run rough
continuously. At the time the Cessna was over a golf
course, and as the remainder of the flight was going to
be over residential areas, the instruc tor decided to
m ake a precautionary landing on to the golf course.
From the air the area he chose appeared mainly level ,
with a slight up slope at its northern end. He elected
to land towards the north -west a nd accept a lig ht
ta il wind .
22 I Aviation Safety Digest 127
are ten operating recommendations which , while
taken from a Lycoming Service Letter, have
general applicability.
Operating recommendations
• Ensure t h at your engine is fitted with the correct
spark plugs. Do not simply repl ace plugs with t hose
of the same part number , as someon e before you
might have installed the wrong plugs. Refer to the
appropriate references to determin e the specified
part number.
• Do not accept an over-rich carburettor or fuel
injector at idle or off-idle engine speeds : always have
the mixture adjusted if necessary .
• After a flooded start, slowly run the engine to high
power to burn off h armful lead deposits, then return
the engine to normal power.
• When parked for extended periods, a void idling
with low rpm. Although Avgas contains a lead
scavenging agent, it only functions with a spark plug
nose core temperature of 800°F. T o ach ieve that
temperature a minimum of 1200 rpm are required;
thus 1200 is a good setting for ground operations
(excepting taxiing, where appropriate rpm must
obviously be used). At 1200 rpm the engine will also
run cooler and smoother, and alternator or
generator output will be higher.
• Use n ormal recommended leaning techniques during
the cruise regardless of altitude, and re-lean the
mixture if carburettor heat or alternate air is
selected. For training establishments, a ircraft
should , if p ossible , not be used exclusively for
circuits, where the mixture almost invariably will be
full rich: try to sch edule all aircraft for a share of
When the aircraft was at about 100 feet on final
approach, it became evident that the selected l an ding
area initially sloped down. The Cessna landed about
h alfway along a fairway, but as there was a gutter
which crossed the landing path, the pilot did not
attempt to brake. H e was able to 'pull' the aircraft off
the ground to clear the gutter. H eavy braking was
commenced when the aircraft touched down again
an d, as it p assed over terraced tees which had soft
surfaces, the nose wheel and propeller 'dug in' .
The Cessna cam e to rest on a tee near the golf
course boundary.
Investigation
The cause of the rough running of the engine was
found to be, not the birdstrike, but lead fo uling of
several spark p lugs. T h e birdstrike was a fac tor,
however, ,i n the pilot's decision to carry out a
precautionary landing -a decision which was prudent
in the circumstan ces.
A reason for the reported high engine oil
temperature was n ot determined, but it was probably
related to the rough running.
Discussion
While spark plugs wh ich reduce the possibility and
effects of plug fouling are availa ble, the p roblem
remains fa irly common among GA a ircraft. Som e
engines seem more prone to fouling than others, but
t he phenomenon is sufficiently widespread to warrant
the attention of all p ilots and LAMEs . Listed below
cross-country fligh ts.
• 'P lan ahead inflight and a void fast, low-power
descents from cru ise altitudes. Descend with power
on and avoid over-rich oper ations ..
• If possible (and commensurate with good
aiimanship ) try to avoid power-off landing,
approaches, as carburettors and fuel injectors are set
slightly rich at closed throttle.
• Keep engine-operating temperatures in the normal
operating range - some pilots seem to harbour t he
misconception that the lower t he temperature the
better it is for the engine. Also keep cylinder head
temperatures within the normal operating range b y
use of normal power settings, proper leaning, and
correct use of cowl flaps . In extreme winter
temperatures oil cooler baffles may be necessary to
m aintain satisfactory oil temperatures .
• Swap top and bottom spar k plugs every 25- 50 hours,
as the top plugs scavenge better than those at the
b ottom. (Note: this recommendation is considered to
be particularly significant.)
• Before shutdown following either fligh t or ground
operations, go to 1800 rpm for 15- 20 seconds,
reduce to 1200 rpm, then shut the engine down
immediately using the mixture control.
Comment
As usual, prevention is better t h an cure. When
supplemented by the manufacturer's instructions for
your aircraft 's particul ar engine type , the guidance
given here should help you to avoid the potential
hazards of spark plug fou ling •
Monitoring 121.5
1:1
Aeronautical Information Circular CO 10I 1985
commented, among other th ings, that . .. 'inflight
monitoring of the distress frequency, 121.5 MHz, is
common practice with many pilots engaged in
International , Domestic or General Aviation
operations. Such monitoring, whether conducted
continuously or merely to the extent that a
particular operation will allow, is beneficial to the
SAR organisation a nd is a practice which all pilots
should adopt where practicable'.
An experienced pilot has recounted to the Digest
an occurrence in which his long-standing habit of
listening out on the distress frequency paid
handsome dividends for a group of survivors.
Listening out
'For many years I h ave been listening on 121.5
whenever I am flying an a ircraft with a spare VHF. I
have also advocated this practice to many other
pilots, particularly during multi-engine endorsement
training. I realised the value of this practice from
flying internationally.
'In fact, for several years I have inserted the
following paragraph in the operations manual of
a bout three air ch arter companies of which I have
been the chief pilot:
"If a second VHF is carried, a listening watch
shall be kept at all times when practkable on
121.5 MHz."
'Apart from listening for emergency be~cons, the
practice has been a d vantageous several tirhes when
establishing contact with or from other aircraft when
other frequencies have failed to make contact. These
examples have occurred both in Australia and
overseas.
'Recen tly during a flight from Cairns to Da ru
(Papua-New Guinea) , approximately 40 nm east of
Lockhart River, t his practice hit the jackpot. I
commenced hearing a weak emergency beacon
signal a nd immediately reported this fact to Weipa
Flight Service Unit.
'The story as I later heard it was that the
Coastwatch aircraft was immediately despatched to
the area and, subsequently, a State emergency
helicopter rescued three people from an uninhabited
island: they had been there for four days after their
yach t had sunk. The beacon had been transmi tting
during this p eriod and its battery was nearly flat.
'A recent AIC has advised listening on 121 .5, and
my experience certainly confirms that advice as these
three people would possibly have otherwise
perished'•
A viation Safety Digest 12 7I 23
�
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~USTRALIV
~
�Contents
'Mateship' and responsibility
5 Ultra-lights and low-level turbulence
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation
Regulations and is published by the Australian Government Publishing
Service. It is distributed free of charge to Australian licence holders
(except student pilots), registered aircraft owners and certain other
persons and organisations having an operational interest in Australian
civil aviation.
6 Flying Vyse, and the pilot's handbook
Unless otherwise noted, articles in the publication are based on
Australian accidents or incidents.
7 Assessing a forecast
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
3 'Mateshlp' and responsibility
4 Carriage of liquid nitrogen in the cabin of small
aircraft freighters
8 A circling approach
10 Unauthorised modification
11 Carbon monoxide poisoning
12 Outside storage of fuel and oil drums - stop
water contamination
13 Know your systems: the mixture control
The Publications Distribution Officer
Department of Aviation
P.O. Box 18390, Melbourne, Vic. 3001
Aviation Safety Digest is a/so available on subscription from the
Australian Government Publishing Service. Inquiries and notifications of
change of address should be directed to:
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.C.T. 2601
17 Helicopters and ground fires
Subscriptions may a/so be lodged at AGPS Bookshops in the capital
cities.
18 Dynamic rollover
Reader contributions and correspondence on articles should be
addressed to:
20 An eventful weekend (reader contribution)
22 Incorrect ground handling procedures
The Director
Bureau of Air Safety Investigation
P.O. Box 367
Canberra City, A.C.T. 2601
© Commonwealth of Australia 1985
ISSN 0045-120 7
R84/ 403(1) Cat. No. 85 104 5 X
Printed by Finepress Offset Printing Pty Ltd
49 Railway St, Yennora, N.S.W 216 1
Front cover
The cover features a highly commended entry in the Digest's recent
photographic competition. Submitted by Mr Han van Loon of
Canberra, it depicts the relationship between aircrews and air traffic
controllers.
2 I Aviation Safety Digest 126
One of the best -publicised characteristics of Australian
social relationships is that of 'ma teship'. Among the
elements which seem to make up mateship are admirable
qualities such as friendship, loyalty , dependability and so
on. Central to this ethos is the notion of 'sticking by
your mates'. However, the findings of aircraft accident
investigations sometimes indicate that apparently
mistaken notions of mateship may place lives and
property at ris k . Where such mistaken notions exist, the
question which must always be answered is: are we really
doing a m ate a favour by concealing his potentially fatal
behaviour, both from him and those in a position to do
something about that behav iour? Perhaps nowhere does
this question have more relevance than in aviation.
Consider the following occurrence.
'Heavy landing '
A Chief Flying Instructor of an aero clu b was notified
that one of his aircraft had been damaged in a heavy
landing. At the time of the occurrence it was being flown
by a PPL holder, who was training for his CPL; while two
other c PL train ees were in the aircraft as passengers.
Following an inspection of the aircraft the CF! held
som e doubts abou t the report submitted by the pilot-incommand so he requested an official investigation into
the occurrence. He also continued to make enquiries
himself.
Inspection of the aircraft showed that damage
consisted of slightly bent propeller tips, cracks and
sheared rivets iri the nose wheel doors, a damaged lower
wing-root cover, slight damage to the engine cowling
cal'sed by contact with the flywheel, and a number of
spinner attachment bolts either loose or missing .
It was considered th at most of this damage could have
been cau sed by a heavy landing. This assessment did
not, however, apply to the missing or loose spinner bolts ,
which , it was considered, could only have vibrated loose
over a period of time, i.e., it seemed that the aircraft
must have been flown for some period after the initial
impact which loosened the bolts . Yet according to the
pilot this was not the case.
After the inspection it was not at first possible to
contact the pilot to check the facts . In the interim , ,the
two passengers were telephoned and they both supported
the pilot's original statement.
Later , however, after further discussion, the
passengers recounted a different sequence of events.
Water impact
The pilot had arranged to take the two passengers on an
area familiarisation flight. After some general flying over
land, the aircraft was descended towards a nearby dam.
Weather conditions were fine: the surface of the water
was glassy, there were no ripples and the surrounding
trees could be seen reflected in the water.
The aircraft passed over the dam wall at about 50- 100
feet AGL, still descending , and eventu ally levelled out
over the water at abou t 10 feet. It passed under a set of
power lines which were marked wit h large, coloured
discs.
One of the passengers later said that he had the
impression that the pilot may have been testing them to
see how low he could go before they became scared.
The pilot told the passengers that he had ' trimmed the
aircraft nose-up to prevent the nose fro m dropping
should he let the controls go'. One of the passengers
asked if the operation was safe , to which the pilot replied
that everything was under control and that he had done
this sort of flying before.
After abou t 2 minutes flight at 10 feet above the dam ,
Aviation Safety Digest 126 I 3
�the aircraft suddenly struck the water. The windscreen
was covered with spray and the engine surged.
Fortunately for its occupants the aircraft ' ricocheted'
back into the air; the pilot was able to regain control and
fly away. A climb to 3000 feet was made and general
handling checks carried out.
The pilot then advised his passengers that they would
land to inspect the aircraft, not at the aero club's
aerodrome, but instead at a nearby ALA. Apparently the
landing there was very smooth but, after looking at the
damage caused by the water impact, the pilot told the
others that he would explain to the aero club that it had
been caused by a heavy landing at the ALA. His
passengers agreed to support this story.
After the investigation started, the pilot eventually
came forward and confirmed that there had been no
heavy landing, and that in fact the aircraft had impacted
the waters of the dam during illegal low flying .
Discussion
Before addressing the 'mateship' aspects arising from this
event, it is first worth noting that the pilot had been
briefed previously on the difficulties associated with
judging height over calm water, while he h ad also been
counselled by his supervisors in relation to another
~ltra--liShQ
incidence of illegal low flying in the same area.
Turning to the thrust of this article, it is essential here
to get completely away from the misguided - albeit well
meaning - notions of ' <lobbing in' one's mate.
The plain fact in this occurrence is that it was sheer
good fortune that the three occupants of the aircraft were
not killed. All of those associated with the accident had
an obligation - to themselves , to anyone who might fly
in similar circumstances , and to the pilot concerned - to
try to prevent a repetition which might not end so
fortuitously.
Rather than doing the pilot a favour by initially
helping him conceal the truth, his passengers were doing
him a great disservice. How would the passengers have
felt if, through a repetition of this occurrence, the pilot
had killed himself, and perhaps others. Worse still, how
would they have felt if the pilot had killed other
passengers and survived himself?
Surely the notion of not '<lobbing in one's mate'
involves protecting your mates. Given the nature of
the occurrence described in this article, the best way
to protect the pilot and any subsequent passengers
would have been to do everything possible to ensure
that this pilot never repeated such a stunt again.
There is no question of '<lobbing' or protecting one's
mates, but there is unarguably one of safety, defined
'here in terms of preventz'on and responsibility •
and low-level turllulence
Carriage of liquid nitrogen in the cabin of small aircraft freighters
Photograph courtesy of Mr David Belton, Thruster Aircraft (Aust.) Pty Ltd, Sydney.
I,
l
This photograph of a Lear 35 at Tennant Creek is by courtesy of Mr Brenton Hollitt of Adelaide.
In a recent incident involving a Lear 35 aircraft the
cabin filled with fog following venting of nitrogen
from a container of liquid nitrogen being carried as
cargo. The pilot returned to the departure aerodrome
where the container was off-loaded.
The consignment had been properly prepared and
handled as dangerous goods in accordance with the
requirements of ANO 33.
T h e release of gas from containers of deeply
refrigerated liquefied (non-toxic) gases is normal. The
containers are either continuously vented or protected
against pressure build-up by a pressure release valve.
4 I Aviation Safety Digest 126
The venting of the very cold gas will often form
visible condensation in the atmosphere around the
container and may impair visibility in the cabin of a
small aircraft.
The problem may be rectified by increasing cabin
temperature; however, if the pilot cannot positively
attribute the cause to the foregoing phenomenon he
should take appropriate em ergency action.
Wherever possible, deeply refrigerated liquefied
gases should be carried in cargo holds where fog
formation is of no consequence •
An article entitled 'Ultra-lights aren 't easy' which
appeared in A viation Safety Digest No. 124 pointed out
that the handling characteristics of ultra-light aircraft
can var y significantly from those of GA aircraft. Factors
mentioned included the following:
• ultra-lights tend to have a narrower performance
envelope;
• they have far less power to weight and far more drag;
• because they have less inertia than GA aircraft, when
the throttle is closed or the engine stopped, they lose
airspeed more quickly; and
• as they fly at much lower speeds, they are far more
susceptible to the effects of wind and terrain.
The latter factor appears to have played a part in a fatal
accident involving a Pterodactyl.
The accident
A series of demonstration flights had been arranged by
the aircraft ' s owner. The weather was clear and sunny,
alth ough, while the wind was generally calm , gusts of 5
knots were blowing from widely varying directions.
Thermal activity was also believed to have been
affecting the operating area. T he pilot had about 200
hours on the Pterodactyl but was unfamiliar with fligh t
in thermalling conditions .
Takeoff was commenced in a north-easterly direction
and the ground roll was normal. H owever, when the
aircraft had reached a height of about 10 feet it en tered
wh at appeared to be an involuntary tum to the left. The
turn continued through about 90 degrees. At the same
0
time the climb angle - which is norm ally about 20
degrees - became much steeper than normal: on e
witness said that as the aircraft was flying .away from
him , he could see the canard above the wing plan form.
The engine was reported as sounding normal.
When the aircraft was at an estimated height of 100
fee t its left wing dropped, it turned left through about
180 degrees, and its nose fell until it was in a nearvertical dive.
T he Pterodactyl struck the ground in a 40 degree
nose-down attitu de. Witnesses reported that it appeared
to be recovering from the dive as it impacted.
There was no evidence of mechanical failure or defect.
Initial investigation suggests that the aircraft
encountered a strong thermal after takeoff, which
induced the abnormal climb performance. The wing
drop and auto-rotation probably occurred when the
aircraft exited the thermal. There then was insufficient
height for the pilot to recover from the near-vertical,
post-stall dive.
Comment
Because ultra-lights operate at such slow speeds, the
effects of wind and/or terrain - even a 5 }lnot gust or a
single tree - can produce alarming control problems for
the unwary. In this unfortunate accid ent it seems
probable that the attitude and airspeed changes induced
by a thermal caught the pilot unawares, eventu ally
resulting in a dire situation from which he was una ble
to recover in time. (continued on page 6}
Aviation Safety Digest 12 6 I 5
�Flying Vyse, and the pilot's
handbook
Aviation Safety Digest 125 contained an article titled
'Safe operation of light twins'. A reader has suggested
that, while he found the article generally very
informative and useful, it did not go far enough in its
discussion on flying Vyse - the airspeed that will give
the best single-engine rate-of-climb (or the slowest loss
of altitude). His point was that for many light twins,
Vyse can vary significantly with All Up Weight (AUW),
and that simply to fly the blue radial speed on the
airspeed indicator regardless of AUW may not produce
the optimum performance. The point is a good one.
A review of a number of representative Pilot's
Operating Handbooks (POH ) is instructive in
illustrating this matter.
Many pilots complete their initial twin endorsement
on the Piper PA44 Seminole. The POH for the 180T
model stipulates in Section 2 (Limitations) that the
'one engine inoperative best climb speed' is 88 KIAS;
no qualifications are given. This is confirmed in
Section 5 (Performance) in the one engine inoperative
climb performance graph, where 88 KIAS is
recommended regardless of AUW. For this aircraft,
then, the manufacturer has determined that the
operational simplicity of a single 'blue line' speed
outweighs any minimal performance increase that
varying Vyse might achieve.
Similar operational advice is given in the
Beechcraft Baron 58/58A POH. Section 2 nominates a
Vyse without any qualifications, and Section 5 advises
that the one engine inoperative climb speed is 101
knots for all weights. Again, this represents the
manufacturer's best assessment of operational
performance, taking all variables into account.
Some aircraft, however, do derive significant
performance benefits if the pilot flies a Vyse
appropriate to AUW. The Cessna 310 is a good
example.
Section 2 of the POH for the 310R defines a Vyse of
106 KIAS ' ... at sea level standard day conditions and
5500 pounds weight'. The POH is perhaps slightly
ambiguous here, for while that definition implies that
Vyse will vary, Section 2 also links Vyse to the blue
radial marked on the airspeed indicator at 106 knots.
Reference to Section 5 resolves any doubts. The rateof-climb one engine inoperative data includes a table
which stipulates that at sea level, Vyse should be
varied from 98 knots at 4700 pounds AUW to 106
knots at 5500 pounds. This is a significant difference
in airspeed, and it can give an important
performance gain.
An even more graphic example is provided by the
Cessna 402B, in which the Vyse range a't sea level can
vary 19 knots with AUW.
Summary
Vyse varies with weight for all multi-engine
aeroplanes, being highest at the maximum take-off
weight (MTOW) and lower for lower weights. For some
light twins the range of Vyse is small and
manufacturers may publish only the Vyse appropriate
to the MTOW. It is this speed which is shown on the
airspeed indicator at the blue radial.
The increase in performance which accompanies a
reduction in aircraft weight greatly exceeds the
penalty which results from flying at the blue radial
speed rather than the correct Vyse. When flying at
the blue radial speed the performance will never be
less than the performance available at the MTOW.
Where the Pilot's Operating Handbook contains
performance data on Vyse, your pre-flight planning
should include a determination of Vyse appropriate
to your take-off weight. In the event of an engine
failure, you should maintain this predetermined Vyse
rather than the blue radial speed. If only one value of
Vyse is published in the POH for your aeroplane,
maintain the blue radial speed •
Ultra-lights and low-level turbulence (continued).
Not only do ultra-lights fly at comparatively low
indicated airspeeds but, also, in many cases , a narrow
band exists between cruise and stall speeds: something in
the order of 20 knots is not uncommon. Given that stall
speed effectively doubles in a 60-degree-bank level turn,
pilots must exercise considerable caution when operating
in gusty conditions in which airspeed fluctuations and
uncommanded bank inputs are likely. Furthermore, any
problems which arise in such conditions are likely to be
compounded by the fact that ultra-lights operate at low
. altitudes.
6 I Aviation Safety Digest 126
Conclusion
There are two main causes of low-level turbulence:
• thermal movement of air, and
• mechanical disturbance of airflow.
A detailed article on low-level turbulence appeared in
Aviation Safety Digest 109.
Regardless of his aircraft type - wide-bodied jet or
homebuilt - a pilot needs to understand the causes of
low-level turbulence and its possible effects. This
knowledge is especially important for ultra-light pilots •
~ing
a forecast
A Cherokee Six 300 took off from Birdsville in the early
afternoon, en route for Alice Springs. The flight plan
for the route had b een submitted that morning at
Broken Hill, using meteorological data issued there.
Initially the aircraft climbed VFR to its planned
altitude of 6500 feet and then took up a heading of
282°M. Tracking was verified as accurate when the first
reporting point selected by the pilot, Goonamillera
Water Hole , was overflown some 36 miles outbound . A
standard positon report was made, with the elapsed time
to the next position at Geosurvey Hill amounting to 65
minutes.
About 30 minutes after passing Goonamillera Water
Hole the pilot decided he would have to descend to
maintain VMC . Accordingly the PA32 was descended to
3500 feet , which placed it below the cloud layer. At that
altitude the pilot found visibility poor as the sun was
creating a diffused glare through the clouds, while the
terrain was darkened by the cloud cover. Map reading
features on the Simpson Desert became difficult to
discern, so the pilot decided to maintain heading on
282°M.
When the ET A for the next position report eventually
arrived the pilot was disturbed by the fact that the
terrain did not match that depicted on his chart.
Contact was made with Alice Springs Flight Service
Unit and, after some discussion, the pilot advised that
he was unsure of his position. An Uncertainty Phase was
declared and actions taken by the FSU to assist the pilot
with his navigation.
Some time later the P A32's ADF gave a steady bearing
on Alice Springs NDB and the pilot was able to track to
the aerodrome without further difficulty.
*
*
*
The relevant route Area Meteorological Forecast showed
that there was a surface trough situated close to the
Birdsville-Alice Springs track. At latitude 25° South which lies roughly along the planned track - the wind
direction was predicted to change through about 120
degrees at the 7000 foot altitude, depending on whether
one's position was north or south of the trough.
The Cherokee pilot had completed his flight plan
using the forecast 7000 foot wind velocity for south of 25
degrees South, 250/ 15. The groundspeed from this wind
gave a total elapsed time interval to Alice Spi;ings of 188
minutes.
However , once the aircraft was descended to 3500 fee t
it was affected by a markedly different wind velocity 140/ 15 - than that on which the flight plan had been
based. The pilot did not allow for this.
With a wind of 140/ 15 instead of 250/ 15, the
aircraft's groundspeed would have increased from 108
knots to about 138 knots, and the elapsed time interval
Birdsville-Alice Springs would have been shortened by
about 36 minutes . This explained the navigational error
which became apparent at ETA Geosurvey Hill.
Comment
Navigating for long periods over relatively featureless
terrain can be a demanding exercise, invariably
requiring meticulous preflight preparation. In these
circumstances, attention to the weather must be even
more thorough than usual. While weather forecasts
obviously must be tempered by inflight observations, a
sound understanding of the total meteorological
situation - not just selected items from it - is essential.
Using this particular incident as an illustration, the
presence of the trough near the planned route should
have been a factor to be considered by the pilot when a
change to his flight planned altitude became necessary.
Thus, while it may be unrealistic - given his workload
at the time - to expect the pilot to have referred back
to the forecast while he was descending, an awareness of
the overall weather conditions should have alerted him
to the possible consequences for.his flight planning of
the surface trough.
As it was, during the descent the wind velocity
affecting the PA32 changed from a headwind to a
tailwind. Although this change had been forecast it was
not used by the pilot and, when allied to the difficult
visibility, it eventually caused him to become unsure of
his position.
Finally, it should be said that the pilot did a good job
in resolving his predicament b y notifying the FSU of his
problem and seeking assistance in time, i.e ., while
factors such as fuel and d aylight remaining were still in
his favour •
2301 2 ADDNYM
AMD ARFOR 0300 TO 1 700 AREA 85
BASED ON SITUATION FOR ADDN FIR AT 222300
MET SITUATION: SFC TROUGH NEAR JVS/WIS MOVING EAT 20 KTS. RIDGING EXTEND INTO S
AMD WIND 3000 14015 5000 N 25S 12020 S 25S 27015 7000 N 25S 13020
S 25S 2501 5 1 0000 28020 PS07 14000 28025 MS02 18500 2 7030 MS10
Reprinted here is a copy of the Amended Area Forecast for Area 8 5, based on the situation for the Darwin FIR at 22 2300, and
valid from 0300Z to 1 70 0 . Note that the wind at 3000 feet is forecast as being 140115, while at 7000 feet and North of 2 5 °
South it is 130/2 0, but South of 25 ° S (the wind used by the pilot in planning) it is 250115.
Aviation Safety Digest 126 I 7
�A circling approach
Effecting the transition from instrument to visual flight can be a demanding exercise, involving as it does a
sudden change of one's visual perceptions and the need for rapid re-orientation. These demands are likely
to be most pronounced during conditions of reduced visibility and/or marginal weather. Regardless of the
circumstances, changing from instrument to visual flight is a procedure which requires concentration,
discipline and adherence to the clearly defined criteria.
In preparation for a charter flight planned for the
following day , a CPL holder with a Class One Instrument
Rating was ferrying a Beechcraft Duchess to the
departure aerodrome. T he pilot who was to carry out
the actual charter flight was on board the Duchess as a
passenger, but was assisting the pilot-in-command with
radio transmissions.
Before taking off qn this ferry flight - which took
place at night - the pilot had been given an actual
weather report for his destination which indicated that
conditions were below minima . This information was
confirmed by a report that preceding traffic had been
unable to land at the aerodrome followi ng NDB
approaches, and had diverted. The cloud base was
reported to be 500 feet AGL, about 500 feet below the
NDB minimum.
On arrival an NDB letdown was carried out from
which, according to the pilot , he became visual right on
the minimum altitude of 3100 feet.
Transitioning to visual flight, the pilot joined
crosswind for his selected runway and descended to 2700
feet (aerodrome elevation was close to 2100 feet). On
downwind he lowered the u ndercarriage and airspeed
decreased to about 100 knots. He then found that he
had to turn slightly to his left to avoid some cloud: this
in turn put him too close to the runway so he
con tinually had to look over his left shoulder to keep the
runway in sight.
A b ase turn was commenced and 15 degrees of flap
selected. It seems tha t at this stage the pilot was
experiencing considerable difficulty in retaining visual
contact with the runway, for he la ter stated th at during
the base turn h e was not sure what the airspeed was or
whether the Duchess was descending.
Eventually accepting that his attempted approach was
not complying with t he criteria - indeed he later stated
that he lost sight of the runway completely - the pilot
decided to make a missed approach. He applied full
power , raised t he aircraft 's nose and retracted its landing
gear and flap.
While the gear was still retracting the aircraft struck
power lines and then a roadway, and came to rest
uprigh t in a built-up area after a ground slide of 82
metres.
When investigators examined the accident site, it was
found that the aircraft was actually below the level of
the aerodrome when it impacted the power lines - it
was little wonder, then, that the pilot had b een unable
to see the runway lights.
Analysis
Relevant factors identified during the. investigation
included the following:
• poor weather;
• pilot continued with the circuit in unsuitable weather
conditions;
• loss of visual contact with the runway;
• failure to carry out a missed approach when
conditions clearly dict ated the need to do so;
• descent below a safe height.
Discussion
T he stand ards and procedures for the kind of approach
attempted by the Duchess pilot are listed in the
Instrumen t Approach and Landing Charts section of
AIP. Obviously instrument-rated pilots must know all of
them thoroughly and adhere to t heir detail. Several of
the more salient points are the need to:
• establish visu al reference within the prescribed
circling area at an altitude not below the m inim um
altitude and by reference to the specified aid or aids;
• maintain visual reference; and
• achieve an obstacle clearance of at least 400 feet by
day and 600 feet by night until the aircraft is aligned
with the runway, strip or landing d irection in use.
Conclusion
To reiterate, making the transition fro m instrument to
visual flight demands a rapid change of orien tation and
perception. Strict adherence to established criteria and
practices is essential during this procedure.
Per haps attention should also be drawn to the lack of
action, in the form of monitoring progress, from the
passenger/ pilot, who was more experienced than the
pilot-i n -command. Accepting that he was just a
passenger, it nevertheless does not seem unreasonable to
suggest that in view of his relative degree of experience
a nd the difficult conditions , he migh t have closely
monitored the approach, not so that he could
interfere - this could be coun terproductive and even
dangerous - bu t rather to draw timely a ttention to any
matters of concern. Apparently this was not done •
Upper left: approximate flight path and power line impact.
Lower left: The runway threshold is 600 metres away in the direction the aircraft is pointing . The aircraft came to rest 15 degrees off the
runway heading.
8 I Aviation Safety Digest 126
Aviation Safety Digest 126 I 9
�Unauthorised Illodification
Positive and specific procedures have been established in
Australia for the incorporation of modifications into
aircraft. On occasions it may seem tempting to bypass
those procedures, when a proposed mod. seems relatively
straightforward. There can, however, be many factors to
consider which are not immediately apparent but which,
if ignored, can create hazards. Unauthorised work
carried out on a Piper PA 32 provided a case in point.
*
*
*
A PA32 arrived at a remote locality after a long flight.
Several passengers disembarked and the pilot left shortly
afterwards for another destination.
After the Cherokee had departed one of the
disembarked passengers mentioned to a bystander that,
in the course of the flight, a number of the passengers
had developed headaches and the pilot had been sick
several times. The bystander recognised those symptoms
as possibly being attributable to carbon monoxide
poisoning, and contacted the Bureau of Air Safety
Investigation. An investigation was initiated.
Findings
During a subsequent flight test carrying an airworthiness
surveyor with test equipment, excessive carbon monoxide
was indeed detected in the aircraft's cabin: in some
positions it exceeded the allowable level by a factor of
five. The gas was found to be entering the cabin
through the overhead duct assembly, which was
connected to a louvre scoop - which had been fitted
without approval - in the area where the air
conditioning condensor unit should have been. This
louvre scoop was drawing contaminated air into the
aircraft from the fuselage under-surface. The end result
of this unauthorised modification was, in the words of
the safety investigators, 'a massive carbon monoxide leak
into the cockpit of the aircraft'. To make matters worse,
the poisonous gas was entering the aircraft through vent
outlets located near the crews' and passengers' heads .
Conclusion
This incident graphically illustrate~ the potential danger
of unauthorised modifications. One of the big traps is
that seemingly harmless changes to an aircraft's
configuration can in fact have insidious and far-reaching
consequences. Part of the rationale for the formal
modification process is to give specialists the opportunity
to consider thoroughly all of the possible effects for the
safe flight operations of a proposed mod.
Finally, concerning inflight procedures, the action of
the pilot in immediately flying another trip after most of
those on board had been sick for no apparent reason
must be questioned •
In brief
It has been suggested that pilots working under
pressure may misuse some types of navigation
plotters. For example, the IPR-13 ICAO Plotter, which
is made from clear plastic and is used on both sides,
has a scale for measuring 1 :250 OOO, 1 :500 OOO and
l: 1 OOO OOO navigation charts on one side in nautical
miles; and the same provision for measuring distances
in kilometres on the other side.
Because the instructions for using the plotter are
presented on the ' kilometres' side, the possibility
exists that a pilot who was not as familiar with the
plotter as he should be, and under a high workload,
might refer to those instructions and then forget to
turn the plotter over before making a distance
measurement: i.e. , he would measure in kilometres
instead of nautical miles.
Familiarity with your equipment, and a quick
mental double-check of all calculations are the best
safeguards against such possible pitfalls.
*
*
*
An item in the Canada Aviation Safety Letter
illustrated the dangers of inadequate maintenance on
pilot's seats:
A Cessna 206 was making its first flight after
maintenance. With 20 degrees of flap selected, the
1 OI Aviation Safety Digest 126
Carbon monoxide poisoning
pilot rotated at about 50 knots. Just after liftoff his
seat slipped backwards, leaving him beyond the reach
of the rudder pedals. As he struggled to keep control
the aircraft climbed to 100 feet, veered left and, with
full power on, struck the ground.
Examination of the seat assembly showed that all
four rollers were extremely worn and should have
been replaced prior to the accident. The seat rail
guides were also worn and slightly expanded. This
allowed the seat to move, even though it was locked
in by an adjustment pin. (This particular model had
only one adjustment pin, while some models have
two.) The combination of worn seat rollers with
acceleration forces in the nose-up rotation attitude
allowed the seat back-top to move rearward, lifted the
two front rollers off the seat rail, and pulled the
adjustment pin out of the locking hole, allowing the
seat to slide rearward.
It is a good idea to have a look at the condition of
the seat assembly during your walkaround.
Also, if possible, lock the seat in the desired setting
for flight and check the position of the pins visually .
A well-maintained seat assembly and properly
locked pins will go a long way towards ensuring that
you and your aircraft leave the ground
simultaneously e
Carbon monoxide is the product of the incomplete
combustion of carbonaceous material. It is found in
varying amounts in the smoke and fumes from burning
aircraft engine fuels and lubricants. T he gas itself is
colourless, odourless , and tasteless bu t is usually mixed
with other gases and fumes which can be detected by
sight or sm ell. It is lighter than air and so tends to be
around the heads of persons in confined spaces such as
light aircraft cockpits.
When carbon monoxide is breathed it combines with
haemoglobin, the oxygen-carrying agent of the blood.
The affinity of haemoglobin for carbon monoxide is over
250 times greater than for oxygen. The product of
carbon m onoxide and haemoglobin ,
carboxyhaemoglobin , has a two-fold effect. First, it
red uces the oxygen -carrying capacity of the blood and,
second , it reduces the process by which oxygen is
transferred from the blood to body tissues. Not only is
the oxygen carriage diminished but also the redu ced
amoun t of oxygen cannot be fully u tilised. The first
organ to be affected by the shortage of oxygen is , as in
hypoxia, the brain. A person's ability to perceive, store
and process information and then make decisions is
impaired. Exposure to small amounts of carbon
monoxide over a period of hours will reduce performance
and is as dangerous as a short exposure to a high
concentration of carbon monoxide. Carboxyhaemoglobin
slowly rever ts to haemoglobin on breathing fresh air free
of carbon m onoxide but it may take 2- 5 hours to reduce
the carbon haemoglobin level by half (half life).
The effects of carbon monoxide poisoning increase
with altitude . As altitude increases , air pressure decreases
and the body has difficulty getting enough oxygen; add
carbon monoxide which fur ther deprives the body of
oxygen, and the situation can become critical. Inhalation
of tobacco smoke also introduces carbon monoxide into
the body in significant quantities . It has been suggested
th at the smoking of one cigarette at night at sea level has
the same effect on nigh t vision as being at 4000 ft
breathing air. There is a noticeable reduction in night
visual acuity and the inference is surely obvious .
Many light aircraft cabins are warmed by air that has
been circulated around the engine exhaust pipes. A
defect in the exhaust pipes or cabin heating system may
allow carbon monoxide to enter the cockpit or cabin .
The danger is greatest during the winter months when
the temperature is such that use of the cabin heating
system becomes necessary and windows and vents are
closed. But there is danger at other times too , for carbon
monoxide may enter the cabin through openings in the
firewall and around fairings in the area of the exhaust
system.
Symptoms
Early symptoms of carbon monoxide poisoning are
feelings of sluggishness, being too warm , and tightness
across the forehead. The early symptoms may be
followed by more intense fe~lings such as headache,
throbbing or pressure in the temples and ringing in the
ears . These in tum may be followed by· severe headache,
general weakness , dizziness and gradual dimming of
vision. Large accumulations of carbon monoxide in the
body result in loss of muscular power, vomiting,
convulsions and coma. Finally , there is a gradual
weakening of the pulse, a slowing of the respiratory rate ,
and then death.
What to do about exhaust odours and symptoms
If you smell exhaust odours or begin to feel any of the
symptoms previously mentioned, you should immediately
assume carbon monoxide is present and take the
following precautions:
• Immediately shut off the cabin air heater and close
any other opening that might convey the engine
compartment air to the cabin.
• Open a fresh air source immediately .
• Avoid smoking.
• Inhale 100 per cent oxygen if available .
• If you are flyi ng, land at the first opportunity and
ensure that any effects from carbon monoxide are
gone before further flight.
• Determine that carbon monoxide is not being allowed
to enter the cabin because of a defective exhaust,
unsealed opening between engine com partment and
cabin, or any other factor . It may be wise to consult a
LAME. on this matter, as the source of any leak may
not be evident to a pilot •
Aviation Safety Digest 126 I 11
�Outside storage of fuel &oil drums-
Aircraft accident reports
Stop Water Contamination
SECOND QUARTER 1985
The following information has been extracted from accident data files maintained by the Bureau of Air Safety Investigation . The intent of publishing
these reports is to make available information on Australian aircraft accidents from which the reader can gain an awareness of the circumstances
and conditions which led to the occurrence .
At the time of publication many of the accidents are still under investigation and the information contained in those reports must be considered as
preliminary in nature and possibly subject to amendment when the investigation is finalised.
Readers should note that the information is provided to promote aviation safely - in no case is it intended to imply blame or liability.
Note 1 : All dates and times are local
Note 2: Injury classification abbreviations
If you must store fuel and oil drums outside, do not store them upright. Even
though the bungs are drawn tightly enough to prevent fluid leakage, they still are
not airtight. Rainwater that collects inside the rim of drums stored vertically on
end can be sucked past the bung into the drum when cooler temperatures cause
contraction of the internal air and fluid. This water now contaminates the fluid and
also may, in time, form rust under the drum lid which can flake off and add a
particulate contamination problem.
P
S
= Passengers
=Serious
0
M
= Others
= Minor
N
= Nil
PRELIMINARY REPORTS (The following accidents are still under investigation)
-0-:
/
= Crew
= Fatal
e.g . C1 S, P2M means 1 crew member received serious injury and 2 passengers received minor injuries.
I
"- I
Water
C
F
Date
Time
\
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
12 Apr
Piper 31-350 VH-AOX
Supplementary Airlines
C 1S, P6S, 1 M, 1 N
1624
Pt. Macquarie
Pt. Macquarie NSW/Coffs Harbour NSW
8521024
Just after lift-off, the pilot reported that the aircraft experienced a loss of power. As there was insufficient runway remaining to land, the pilot raised
the gear and flap but the aircraft did not continue to climb. The pilot decided to land the aircraft straight ahead off the end of the runway. During the
landing the rear fuselage impacted a dirt bank and the aircraft ran through a fence before coming to rest.
Powerful
suction
12 Apr
Piper 25-235 VH-PTX
Aerial Agriculture
C1N
17 15
Mareeba Old 1 E
Atherton Old/Atherton Old
8511017
During the pull up at the end of a downwind spray run, the right wing struck a tree. The aircraft was landed without further damage at a nearby
aerodrome.
14 Apr
Cessna 404 VH-LAD
Charter - passenger operations
C1 N,P8N
1005
Moomba SA 65NW
Adelaide SNLake Coonamooranie
8541008
During the landing roll the aircraft suddenly veered to the left. The pilot took corrective action but the nose gear collapsed and the nose section of
the aircraft struck the strip surface.
When delivered
Heating causes expansion
and escape of air
16 Apr
Hughes 269C VH-PHK
Non commercial - aerial application/survey
C1 N,P1 N
1530
Mt Hope Old
Mount Hope Old/Scartwater Sin. Old
851 10 18
The pilot reported that just after lift off the engine seemed lo lose power. She manoeuvred the helicopter to a suitable landing area, but during the
landing the main rotor blades struck a sapling. The helicopter was then repositioned lo another landing site where the engine was shutdown and the
damage to the main rotors noticed.
When cooled, water is
sucked past bungs
02 May
Hughes 269C VH-RIK
Commercial - aerial mustering
C1N,P1N
1430
Balbirini Sin. NT
No. 6 Bore Balbirini Stn./No. 6 Bore Balbirini Sin . 8 541010
The pilot was attempting to move a cow back into the mob. He brought the helicopter to a low hover close to the animal. The animal spun around ,
reared up and caught its horns on the helicopter skids. The helicopter pitched forward and struck the ground.
To prevent this situation store drums so that rainwater cannot collect and cover
the bungs.
04 May
Cessna U206 VH-POT
Sport parachuting (not associated with an airshow) C 1 N
1745
Meredith Vic
Meredith Vic/Meredith Vic
8531015
The aircraft initially touched down about halfway along the strip , became airborne again, then touched down 50 metres before the end of the strip.
The pilot applied power to go-around. However, after reassessing the situation, he closed the throttle and attempted to steer the aircraft through a
gate. The nose wheel dug into the ground and the aircraft lilted forward onto the propeller and left wing . The propeller spinner struck the gate and
the aircraft stopped.
..
07 May
Cessna 3 1 ON VH-KOM
Charter - cargo operations
C 1N
1755
Cudal NSW
Cudal NSW/Bankstown NSW
852 1028
On the two previous landings the pilot noticed a nose wheel shimmy during the landing roll. As his next stop was at his company's maintenance
base, he advised the company of the problem. No nose wheel shimmy was noticed on landing, however, the aircraft was inspected by service personnel. During the subsequent take-off, a violent shimmy developed, the pilot abandoned the take-off as the nose leg strut fractured.
09 May
Beech 0 55 VH-KNE
Charter - passenger operations
1605
Dalwallinu WA
Carnamah WNDalwallinu WA
The aircraft was landed at the destination strip with the gear up.
C1N,P5N
855101 1
13 May
Ayres SR2 VH-WBU
Non commercial - aerial application/survey
C1F
1 700
Mungindi NSW
Mungindi NSW/Mungindi NSW
8521 029
The flight was intended to provide familiarisation for the pilot on the aircraft type . After loading water into the hopper the pilot took off and carried out
a series of turns before positioning for a spray run along one of the flight strips. Al the end of the run the aircraft pulled up steeply and began banking to the right. It then appeared to enter a spin to the right and subsequently struck the ground in a steep nose-down attitude with little forward
speed.
:lil i!illil
..·.·.·.·.·.·.·.·.',·.·.·.·.·.·.·················
12 I Aviation Safety Digest 126
15 May
Piper 3 2-R300 VH-PNB
Non commercial - business
C1F,P3F
1335
Babinda Old SW
Townsville Old/Cairns Old
8511019
The pilot received a weather briefing before departing Townsville which indicated that the weather enroute was unsuitable for visual flight. After being issued with a clearance to enter Cairns control zone no further transmissions were received from the aircraft and it failed to arrive at Cairns. The
wreckage of the aircraft was located in rain forest on the lower southern slopes of the south peak of the Bellenden Ker Range. The weather in the
area at the time was reported as low cloud with heavy rain.
Aviation Safety Digest 1 2 6 I i
�Date
Time
Akcraftlype & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
18 May
Cessna 172F VH-DNV
Non commercial - pleasure
C1 N,P3N
1505
Curl Curl Beach
Richmond NSW/Richmond NSW
8521031
The aircraft was cruising at 500 feet above some Sydney area beaches. Following an ATC instruction, the pilot applied full power in order to climb
to 2000 feet. Shortly afterwards the engine lost all power and the pilot was committed to a forced landing in shallow water. Touchdown occurred
about 5 metres from the shore-line and the aircraft came to rest inverted in the water.
20 May
Robinson R22 VH-ONE
Commercial - aerial mustering
C1 N,P1 N
1130
Mt House Sin. 37NW
33NW Mt House Sin. WN33NW Mt House Sin. WA 8551012
After the helicopter had been transitioned to forward flight, the pilot felt a vibration through both the collective and cyclic controls. During his
attempts to stop the vibration, the helicopter was allowed to descend. As he then selected a climb attitude the helicopter yawed to the right. The
pilot was unable to correct the yaw and the tail struck a tree which slowed the yawing and allowed the pilot to land the helicopter. Initial inspection
revealed that the intermediate flexplate in the tail rotor drive system had disintegrated.
22 May
Piper 28-161 VH-IJK
Non commercial - pleasure
C1 N
2015
Goulburn NSW
Bankstown NSW/Goulburn NSW
852 1033
The pilot was conducting a night cross-country exercise to maintain his recent experience requirements. On final approach he realised that the
aircraft was undershooting. Engine power was applied but the pilot then saw power lines ahead , too late to take any avoiding action. The aircraft
struck the wires and subsequently impacted the ground 211 metres short of the threshold. The wires struck provided power for the airfield lighting,
which was extinguished at the time of collision.
27 May
Bell 4 7-G5 VH-AEO
Commercial - aerial mustering
C1N,P1N
1030
Normanton 140E
148E Normanton Old/148E Normanton Old
8511021
While flying at a slow forward speed approximately 1 5 feet above the trees, the helicopter suddenly yawed to the right. As the pilot was unable to
correct the yaw he attempted to manoeuvre the helicopter to a clear area. The helicopter impacted the ground in a level attitude, heading rearward
and rotating. Initial investigation has revealed that all the teeth were missing from the rear coupling of the forward short shaft.
29 May
Bell 47-G5 VH-SJY
Commercial - aerial mustering
C1F,C1S
0930
Ivanhoe WA
Ivanhoe Station WNlvanhoe Station WA
8551013
The helicopter was being flown at about 50 feet agl, when one main rotor blade grip failed. The main rotor blade separated from the helicopter and
the resulting imbalance caused the other main rotor blade and transmission to be torn from the helicopter. The fuselage then fell to the ground,
landing on its right side.
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record Number
21 Jun
Piper 32-300 VH-MGO
Charter - passenger operations
C1 N,P6N
1422
Mer Island Old
Prince of Wales ls/Mer Island Old
851 1026
When the aircraft became low on approach, the pilot applied power to correct the approach angle. However this resulted in a higher than
recommended airspeed and touch down was not effected until 170 metres after the threshold . As insufficient runway remained for the aircraft to
be brought to a stop, the pilot attempted to carry out a ground loop. The aircraft skidded sideways off the strip and down a st~ep incline before
coming to rest against a tree.
21 Jun
Piper 38-112 VH-MHO
Instructional - solo (supervised)
C 1N
1630
Parafield SA
Parafield SA/Parafield SA
8541012
The aircraft landed heavily and bounced. The pilot recovered the situation and made a smooth landing . He then taxied the aircraft to the parking
area where the damage to the nosegear assembly, firewall and airframe was found .
22 Jun
Robinson R22 VH-HBL
Non commercial - aerial application/survey
C1 S
1057
St Paul's HS 9S
St Paul's HS Old/St Paul's HS Old
8511027
After helping to herd cattle to a yard, the pilot turned the helicopter and accelerated away along a creek. The helicopter struck a powerline, which
crossed the creek at right angles, and impacted the ground on its right side. One of the main rotor blades bounced backwards into the cabin and
almost severed the pilot's right foot.
24 Jun
Conaero LA4-200 VH-EJX
Instructional -dual
C2N
0955
Townsville Old
Townsville Old/Townsville Old
8511028
The student pilot was receiving instruction for an endorsement on the aircraft type . Following a touch and go landing, the instructor closed the
throttle to simulate an engine failure. The subsequent landing was firm and the right wheel broke off. The aircraft ground looped through 180
degrees before coming to rest. Inspection of the gear leg revealed severe corrosion in the internal section of the leg.
27 Jun
Cessna 17 2N VH-WHK
Non commercial - business
C 1N,P3N
0930
Cape Keer-Weer
Cape Keer-Weer/Musgrave Station Old
85 11029
The pilot stated that just after the aircraft became airborne it encountered a strong gust of wind. The left wing tip and nosewheel struck the ground
and the aircraft overturned.
30 May
Cessna 182H VH-PLF
Instructional - solo (supervised)
C1 N
1030
Roma Old
Dalby Old/Roma Old
8511 022
The pilot reported that he had made a good approach, but had flared high. The aircraft landed heavily on the mainwheels then nosewheel. Buckling
of the firewall and undersurface of the fuselage was discovered after the aircraft had been shut down in the parking area.
28 Jun
Smith 600 VH-IGV
Non commercial - business
C 1N,P1 N
0951
Bankstown NSW
Cowra NSW/Bankstown NSW
8521 041
The landing gear was selected down during the downwind leg of the circuit, and the gear down lights were illuminated. The aircraft touched down
normally, but as soon as the nosewheel contacted the runway, the gear warning horn sounded and the nose-gear retracted. The aircraft slid to a
halt on the centre-line of the runway.
03 Jun
Conaero LA4-200 VH-AWY
Charter - passenger operations
C 1N,P2N
1711
Shute Harbour Old
Hayman Island Old/Shute Harbour Old
85 11023
During the landing roll the aircraft began to swing to the right. The pilot attempted unsuccessfully to correct the swing by applying left brake and
rudder. Because of the likelihood of striking a parked aircraft he then induced a ground loop to the right and the aircraft was brought to a stop. An
inspection of the aircraft revealed that the right maingear had unlocked and the aircraft had settled on the right float.
28 Jun
Bell 47-G5 VH-SJA
Commercial - aerial mustering
C1S,P1 M
0700
Burketown 1OOSW
Punjaub Station Old/Punjaub Station Old
8511030
Just after take-off at about 30 feet agl a loud bang was heard and the helicopter started rotating rapidly . The pilot manoeuvred the helicopter clear
of fuel drums but it landed heavily while moving rearward. Initial inspection of the helicopter revealed that the tail rotor drive forward short shaft had
become disconnected after the failure of the top left longeron.
07 Jun
Cessna 210-N VH-RSD
Non commercial - pleasure
C1 F,P5F
1031
Bankstown NSW
Bankstown NSW/Bourke NSW
8521035
Prior to taxying the pilot had checked the all-up-weight of the aircraft and had performed a thorough pre-flight inspection. The take-off and initial
climb appeared to be normal, however when the aircraft had reached a height of about 200 feet there was evidently a loss of performance and no
further height was gained. In response to queries from ATC the pilot indicated that he was returning for landing. During the turn towards the
aerodrome, control of the aircraft was lost. The left wing dropped sharply and the aircraft entered a near vertical descent, subsequently colliding
with a large tree before impacting the ground. A fierce fire broke out and consumed the wreckage.
FINAL REPORTS (The investigation of the following accidents has been completed)
09 Jun
Grumman 164A VH-CCT
Aerial agriculture
C1N
1300
Gayndah Old 30NW
Gurgeena Plateau Oid/Gurgeena Plateau Old
8511024
On the pull-up at the end of the first spray run in that particular direction, the aircraft struck a single wire power line. The pilot immediately landed the
aircraft in a clear area. During the landing roll the right wheel struck a large rock, which was concealed in long grass, and the right main gear was
torn off. The aircraft pitched forward onto the engine and came to rest in a near vertical attitude.
09 Jun
Piper 28- 140 VH-MAM
Air show/air racing/air trials
C1N,P1N
1411
Wedderburn NSW
Wedderburn NSW/Wedderburn NSW
8521036
As part of a club competition, the pilot was required to carry out a practice forced landing on the strip. On the downwind leg the height of the aircraft
was lower than desired and the pilot adjusted his tracking in order to converge with the strip. A continuous turn from downwind to final was
attempted, during which the left wing suddenly dropped and the rate of descent increased. The pilot was able to regain partial control but the
aircraft struck the ground heavily and ran off the side of the strip, colliding with rocks and scrub.
13 Jun
De Hav DHC2 VH-IME
Aerial agriculture
C 1N
1600
Dorrigo NSW 17W
Deer Vale NSW/Deer Vale NSW
8 52 1038
The pilot reported that shortly after take-off the elevator control jammed. He then noted that the horn end of the left elevator was hanging about
eight centimetres below the horizontal stabiliser. The load was jettisoned as the pilot prepared to land but increasing difficulty was experienced in
keeping the aircraft nose up. On short final approach the elevator separated from the aircraft and despite the lack of elevator control the aircraft was
landed without further damage.
14 Jun
Piper PA30 VH·UOY
Instructional - dual
C2N
11 50
Armidale NSW
Armidale NSW/Armidale NSW
8521037
The aircraft entered the circuit in preparation for a practice single engine landing. The gear was selected down, however neither pilot checked that
the gear-down light illuminated. The aircraft was landed with the gear retracted and the pilots reported that they then noticed that the gear motor
circuit breaker had popped.
19 Jun
Piper 32-300 VH-WSZ
Non commercial - pleasure
C1N,P1M,P6N
1053
American Rvr . Sth.
Adelaide SN American Rvr. Sth.
8541011
The pilot established the aircraft on final approach at 80 knots with full flap selected. She allowed the airspeed to reduce to 70 knots as the aircraft
crossed the boundary fence. The aircraft impacted the ground heavily, nosewheel first, from about 15 feet agl. The main landing-gear was
dislodged and the nose-gear folded backwards.
19 Jun
Piper 38· 112 VH-UAL
Instructional - solo (supervised)
C1 N
1• 130
Bankstown NSW
Bankstown NSW/Bankstown NSW
852 1039
On return from his third solo flight, the pilot was attempting to complete a 180 degree tum in a confined area between two hangars. He positioned
the aircraft on the left extremity of the concrete apron prior to starting the right turn . The left outer wing section struck a vertical support for the
hangar located adjacent to the apron.
ii I Aviation Safety Digest 126
Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
03 Apr
Stevens AKRO VH-KGZ
Non commercial - pleasure
C1 N,02N
1857
Darwin NT
Delissaville NT/Darwin NT
8541006
Private
40
900
Unknown
None
The aircraft was part of a four aircraft formation taking part in a photography session. On return to Darwin it was intended that the aircraft land one
after the other on the same runway . The first aircraft landed and the pilot requested a clearance to turn off the runway onto a cross strip. A
clearance was not available due to other traffic on that strip and the pilot was instructed to continue taxying along the runway. As the second aircraft
commenced the flare for landing it collided with the aircraft already on the runway.
The flight had been poorly planned and the briefing conducted before departure was inadequate. The pilot flying the second aircraft to land was
inexperienced on the aircraft type and had no formation flying experience.
03 Apr
Pitts S2A VH-KIT
Non commercial - pleasure
C1 N,P1 N,01N
1857
Darwin NT
Delissaville NT/Darwin NT
8541006
Private
23
101
5
None
The aircraft was part of a four aircraft formation taking part in a photography session. On return to Darwin it was intended that the aircraft land one
after the other on the same runway. The first aircraft landed and the pilot requested a clearance to turn off the runway onto a cross strip. A
clearance was not available due to other traffic on that strip and the pilot was instructed to continue taxying along the runway . As the second aircraft
commenced the flare for landing it collided with the aircraft already on the runway .
The flight had been poorly planned and the briefing conducted before departure was inadequate. The pilot flying the second aircraft to land was
inexperienced on the aircraft type and had no formation flying experience.
05 Apr
Stod Ham Glasair SH2 VH·MVC
Non commercial - pleasure
C1 N,P1N
0645
Casino NSW
Coolangatta Qld/Dubbo NSW
8521023
Private
38
200
21
None
The pilot decided to make an unscheduled landing at an aerodrome enroute to check a problem with the aircraft. On touchdown he noticed steel
pickets on either side of the runway and reapplied power. During the go-around the left wing tip struck a picket, the aircraft yawed and then collided
with other pickets, before the aircraft was brought to a stop.
The aerodrome had been closed for reconstruction work. White crosses were placed on the runway and adjacent to the windsock. The pilot had
not advised Flight Service of his intended landing. The aircraft nose attitude on approach reduces forward visibility and the pilot did not see the
white crosses on the runway. The aircraft yawed as power was applied for the overshoot.
Aviation Safety Digest 126 I iii
�Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
06 Apr
Cessna 172N VH·PVO
Aerial mapping/photography/survey
C1 M
0758
Kemp NT
Darwin NT/Kemp NT
8541007
Senior commercial
.
25
1731
194
Instrument rating 1st class or class 1
The pilot had operated into the strip two weeks prior to the accident flight, and saw a powerline that had apparently been diverted underground,
near one end . After checking with his passengers who were familiar with the area, a landing was made. On this flight a flatter approach was made
and the nose leg snagged on the powertine causing the aircraft to impact the ground in a steep nose down attitude. The 1O metre high powerline
had been diverted to cross the approach area, above ground, 274 metres from the threshold.
07 Apr
Robinson R22 VH-FHK
Non commercial - pleasure
C1 N,P1 N
1240
Pnt Lookout Old
Pnt Lookout Old/Pnt Lookout Old
851 1016
Commercial - helicopter
26
756
566
None
Because of obstructions around the intended landing area, the pilot carried out a downwind approach. As the pilot reduced the speed of the
helicopter for landing it was caught by a sudden gust of wind. The helic9pter sank, struck the ground and bounced before landing on the left skid
which entered a depression in the ground resulting in the helicopter rolling over.
16 Apr
Cessna 172M VH-MAE
Non commercial - pleasure
C 1N,P3N
1300
Hexion NSW
Hexion NSW/Hoxton NSW
8521025
Private
31
120
30
None
On final for runway 16 the pilot noticed another aircraft on departure using runway 34. The climbing aircraft turned right immediately to allow
sufficient clearance for the landing aircraft to continue its approach; however, the pilot elected to go around instead. During the go around the
aircraft mushed onto the flight strip, broke off its nosewheel, nosed over and came to rest inverted 30 metres from the initial impact point.
The aircraft entered the circuit without making inbound or circuit entry calls and because the wind was still directly across the strip, the pilot
decided to use runway 16 which he had used for take-off. Two aircraft already in the circuit, but using runway 34, were not sighted until a head-on
condition had developed with one of them. During the go around, with the speed at about 65 knots, the flaps were fully retracted. Prior to this
departure, a dual check was completed as the pilot had not flown the Cessna 172 for 8 years.
18 Apr
Cessna R182 VH-SMV
Non commercial - pleasure
C 1N
1100
Maitland NSW
Maitland NSW/Maitland NSW
8521 030
Senior commercial
26
2700
100
Instrument rating 1st class or class 1
The pilot decided to carry out a circuit in order to check the performance of the engine . Because of the presence of a gusting 20 knot westerly
wind, a higher than normal approach speed was flown. The pilot stated that he closed the throttle at about 50 feet agl and flared the aircraft. The
subsequent landing was heavy, the aircraft bounced, the pilot moved the control column forward and the aircraft bounced a second time. On the
third touch down the pilot reported that the tail struck the runway causing substantial damage to the tail area of the aircraft.
18 Apr
Cessna A 188·A 1 VH-KOA
Aerial agriculture
C 1N
1500
Seabird WA
Seabird WA/Seabird WA
8551009
Commercial
43
5675
4000
Agricultural class 1
During the take-off run the left wheel locked. The aircraft ground looped to the left, the right gear leg collapsed and the nose section and right wing
struck the ground.
During prior maintenance of the left wheel hub the inboard bearing had not been correctly reinstalled and it subsequently collapsed into the
centre of the wheel assembly during the take-off run.
20 Apr
Piper 32-300 VH·MAR
Non commercial - pleasure
C1N,P5N
1343
Darwin NT
Oum In Mirrie NT/Darwin NT
8541009
Commercial
19
258
100
Instrument rating class 4
After landing, the aircraft was taxiied along a taxiway to the general aviation parking area. In preparation for a 90 degree turn in the taxiway the pilot
moved the aircraft to the right of the taxiway. The nose wheel struck a steel gable marker, which was positioned 500 millimetres off to the right of the
taxiway. As a result of the collision the nose gear collapsed.
The pilot was not concentrating sufficiently on the taxying of the aircraft, which was being operated at a high speed.
01 May
Beech 95-A55 VH-FDP
Non commercial - pleasure
C1 N,P1N
1720
Busselton WA
Bunbury WA/Busselton WA
8551010
Private
52
2700
1100
None
During the circuit, the pilot and passenger were discussing fires near their property. The aircraft was subsequently landed with the gear up.
The gear and its warning systems were serviceable. The pilot's attention was diverted from the operation of the aircraft by the fires and the pre·
landing checks were not correctly completed.
03 May
Piper 30 VH-TOD
Charter - passenger operations
C 1N
1640
Hay NSW 24ENE
Hay NSW/Griffith NSW
852 1026
Senior commercial
28
5500
350
Instrument rating 1st class or class 1
The pilot elected to conduct the flight at a very low height above the ground. The aircraft collided with power lines, which severed the top 1O
centimetres of the rudder. Control of the aircraft was maintained and a safe landing was made at the intended destination.
06 May
Piper 34-200T VH-AOO
Non commercial - business
C1N,P3N
1830
Kempsey NSW
Bankstown NSW/Kempsey NSW
8521027
Private
41
249
151
Instrument rating class 4
The pilot reported that the aircraft was flared normally for the night landing, but it dropped suddenly and struck the runway heavily. Damage was
caused to the nose gear strut. The pilot, believing he was losing control of the aircraft, carried out a go-around. During the subsequent landing, the
pilot was unable to steer the aircraft which veered to the left and struck a cone marker before being brought to a stop.
The aircraft had been observed to fly a close base leg followed by a steep final approach path. The pilot had misjudged the landing flare and
during the subsequent heavy landing the nose gear strut was pushed upward through the aircraft nose, disloding the windscreen and
disconnecting the nose wheel steering. Unknown to the pilot, the propellers also contacted the runway and the tips of all blades had been bent.
18 May
1305
Commerial
Beech 055 VH·ILM
Brampton Island
Non commercial - pleasure
Proserpine Old/Brampton Island
13000
1200
C1N,P6N
8511020
42
Instrument rating 1st class or class 1
with instrument rating
After the pilot selected the gear down, he observed that the single gear position indicator light indicated that the gear was down. During the landing
roll, as the aircraft slowed down, the left wing lip and left propeller contacted the strip. Subsequent inspection of the aircraft revealed that the left
main gear was in the up position.
The left gear uplock bracket-block had recently been repaired but the forward hole had been drilled slightly off centre . This caused the bracket to
tilt rearward and the block to slip off the uplock roller face and jam against the roller retaining bolt. When the gear was selected down the gear motor
drove against the jammed uplock and bent the left retract rod. This allowed the motor to complete its extension cycle and indicate a gear down
condition because the indicator switches are located on the activator housing and not at each gear leg.
iv I Aviation Safety Digest 126
Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
09 Jun
Glasflugel Mosquito VH·GSZ
Non commercial - pleasure
C1 N
1230
Horsham Vic 36SSE
Dadswells Bridge Vic/Dadswells Bridge Vic
8531017
Glider
30
508
250
Glider
During ridge soaring operations , areas of sink were encountered and the aircraft ~escended over fore~ted terrai~ . The only af~a suita~le for.an
outlanding was a small deer enclosure. The pilot initially overshot the area and during the turn to re·pos1t1on the aircraft for landing the right wing
struck the fence surrounding the enclosure. The aircraft yawed through 90 degrees before impacting the ground in a level attitude.
Although general soaring conditions were poor, the pilot had elected to leave the ridge-line to conduct a sight seeing flight. During this flight a
w ind change moved through the area. On return to the ridge-line the pilot, who had not detected the wind change, persisted with efforts to find an
area of lift. The proximity of the aircraft to the tops of the trees and the small size of the deer enclosure precluded the pilot sighting the clearing in
time to conduct a straight-in approach .
27 Jun
De Hav C2 VH·AAY
Activities associated with aerial agriculture
C1 N
0630
Walcha NSW 3NW
Walcha NSW 3NW/Kanimbla Homestead
8521040
Commercial
27
1200
300
Agricultural class 2
The aircraft had been parked in the open overnight. When the pilot arrived at the strip he noted that shallow fog had settled over the area. The
temperature was below freezing point and frost covered the aircraft, except for the windscreen which had been protected by a cloth sheet. A pre·
flight inspection was carried out, but did not include the removal of the frost from the aircraft. Because the fog had reduced visibility to about 50
metres, the pilot taxied the aircraft along the strip to check for obstructions . During this time the moisture froze on the windscreen, however by
reaching from the cockpit the pilot was able to clear the left side of the screen.
Shortly afterwards the take·off was commenced and the lightly loaded aircraft became airborne after a ground run of about 250 metres. At this
point all forward visibility was lost because of frost re-forming on the w indscreen. The pilot noticed that the aircraft appeared to be banking to the
left and he elected to land immediately. The left w ingtip contacted the ground, followed by the main wheels . The aircraft ran off the side of the strip
and collided with a fence, before coming to rest about 100 metres from the strip.
The pilot had had no disciplined instrument flying experience and had been unable to maintain effective control of the aircraft during the take-off
with severely restricted visibility. The degradation in aircraft performance as a result of the frost covering the wings and tail surfaces could not be
established.
FINAL UPDATES (The investigation of the following accidents has been completed . The information is
additional to or replaces that previously printed in the preliminary report.)
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
01 Apr 83
Beech A36 VH-EUM
Private
834 1012
1430
Nundroo SA
29
198
10
None
The pilot had previously discussed the strip with the station owner but had not ascertained its length. On overflying, the pilot assessed its length as
600 metres, and after checking the P-chart he calculated that 500 metres was needed for a landing. The pilot stated that he crossed the threshold
at 65-7 O knots with full flap selected. Ground marks indicated that the aircraft touched down 195 metres past the threshold. It then bounced twice
before overrunning the strip, striking an earth mound and running through a depression.
The grass strip was measured as 408 metres long and was slippery from rain which had fallen the previous day.
09 Apr 83
Beech 95-B55 VH-FDG
Private
8321036
1250
Maitland NSW
30
571
15
Instrument rating class 4
As the aircraft entered the circuit, the pilot selected the gear down. He stated that during the downwind leg of the circuit he completed the prelanding checks, which included checking that the gear was down . Ground witnesses observed that the gear was down as the aircraft joined the
circuit, but when the aircraft was on late final approach the gear was observed to be up.
· Inspection of the aircraft revealed that the extension and electrical indication systems were serviceable, however, the mechanical indication
system was unserviceable. It is probable that the pilot inadvertently retracted the gear during the pre-landing checks.
08 Oct 83
Cessna 177RG VH·IRO
Private
8341031
0941
Kingston (SE)70NW
46
504
350
Instrument rating class 4
During cruise at about 1OOO feet agl the engine began to run roughly and the pilot observed falling oil pressure indications. A severe engine
vibration then developed and the pilot, after selecting a suitable forced landing area, shut down the engine. He delayed lowering the landing gear
until he was satisfied that the selected area had a firm surface. The gear was selected down on very late final, but only the nose gear had time to
become partially extended before touchdown.
Lack of sufficient tension of a nut securing a conrod bolt of Number 1 cylinder allowed the conrod bearing cap to loosen causing loss of oil
pressure and subsequent engine failure .
05 Dec 83
Cessna 501 VH-BNK
Senior commercial
8351029
101 6
Kalgoorlie WA 1ONE
57
11000
650
Instrument rating 1st class or class 1
The pilot returned to Essendon at about 1700 hrs ESuT on 4 December after having operated for some time in Tasmania. On his arrival he refuelled
the aircraft and completed a flight plan for the flight to Adelaide and Kalgoortie the following morning.
At about 0430 hours ESuT the next morning the pilot submitted the flight plan to Melbourne Briefing Office prior .to obtaining a forecast of the upper
winds for the route and terminal area forecasts for Adelaide and Kalgoorlie. To calculate the time intervals for the two legs of the proposed flight the
pilot had assumed a headwind component of 50 Knots. However, the forecast given to the pilot indicated that the headwind component for the
Essendon to Adelaide leg at the planned level, flight level 310, was about 90 knots, and for the Adelaide to Kalgoorlie leg at planned level, flight level
370 was about 100 knots. The flight plan also gave the fuel endurance of the aircraft as 200 minutes ex Essendon and 300 minutes ex Adelaide.
Th'e aircraft subsequently departed Essendon and arrived in Adelaide after an apparently uneventful flight. The pilot left a note to instruct the
aircraft refuellers to refuel the aircraft to full tanks and proceeded to the Adelaide Briefing Office. At the Briefing Office the pilot obtained updated
weather forecasts which indicated that Kalgoorlie required an alternate . The pilot then advised the Briefing Officer that he would nominate Perth as
the alternate. When he was told that the fuel endurance necessary to plan Perth as an alternate would be 302 minutes, the pilot changed the flight
plan to indicate that the fuel endurance of the aircraft ex Adelaide was 320 minutes. At the flight levels planned a fuel endurance of 320 minutes
could not be obtained. The pilot also decided to fly the leg at flight level 290 as the head winds at that level were less than at the higher level,
although still almost twice the strength of the flight planned headwind.
When the pilot returned to the aircraft he found that it had not been refuelled as requested. He then assisted the refuellers to refuel the aircraft by
adding the anti-icing agent to the fuel during the operation. Because of the delay the normal fuelling procedure was not carried out and as a result
the fuel tanks were not filled to capacity. About an hour after departing Adelaide the aircraft entered cloud and encountered icing conditions. The pilot switched on the engine anti-ice and
the cruise was continued at flight level 290 for about 30 minutes before climbing to flight level 310, clear of cloud where anti-icing was turned off.
Operating w ith engine anti-ice on increases the fuel consumption by 8 percent.
Aviation Safety Digest 1 2 6 I v
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
05 Dec 83
Senior commercial
Cessna 501 VH·BNK
8351029
1016
Kalgoorlie WA 10NE
57
11000
650
Instrument rating 1 st class or class 1
Continued
As the aircraft approached the mid-point of the flight the pilot became concerned that he may not have sufficient fuel to continue the flight from
Kalgoorlie to the alternate, Perth. He decided to continue the flight towards Kalgoorlie and if the alternate requirement was not lifted when he was at
a point along track that was 30 minutes beyond Caiguna, he would return and land at Caiguna. Shortly afterwards the alternate requirement was
lifted on Kalgoorlie.
When 185 kilometres east of Kalgoor1ie the pilot commenced the descent and at flight level 250 the aircraft entered cloud and the engine anti-ice
""'.as again switched on. During the descent the fuel low level warning light illuminated and the left engine surged and flamed out at 10,000 feet. The
pilot unsuccessfully attempted to restart the engine. As the aircraft broke clear of cloud at 1OOO feet above ground level the right engine also
flamed out. The pilot made a distress call and landed the aircraft, gear up, on a fire break. After touchdown the aircraft skidded 400 metres before
coming to rest.
The examination of the aircraft found that during the landing the left fuel tank had been breached, however no evidence was found of any
significant fuel spillage. Approximately five litres of fuel was recovered from each of the left and right fuel tanks. The engine fuel filters and fuel lines
provided only a small amount of residual fuel. The inspection of the remainder of the aircraft did not reveal any defects that could have contributed
to the accident.
Significant factors
1 . The flight was inadequately planned, the aircraft had insufficient fuel capacity to complete the flight at planned levels.
2. The refuelling of the aircraft at Adelaide was rushed and as a result the tanks were not filled.
3. During the flight insufficient attention was given to fuel management.
4. The engines flamed out due to fuel exhaustion.
05 Jan 84
Blanik L 13 VH·GIX
Glider
8421003
1655
Leeton NSW 6N
34
15
9
None
After reaching a height of about 200 feet agl on a winch launch, the glider was observed to enter a shallow dive. The drogue parachute was seen to
inflate above the inboard section of the left wing and then trail behind the glider with the tow wire draped over the top of the wing. The glider entered
a left turn which developed into a spiral dive. Partial recovery was effected but the aircraft impacted the ground in a nose-down attitude.
The pilot was relatively inexperienced and was performing his fourth solo winch launch. During the launch the aircraft exceeded the climb speed
limit and the pilot attempted to signal this fact to the winch operator by the normal method, which involves lowering the nose of the aircraft prior to
yawing it from side to side. However, the pitch change used was larger than normal, unloading the tow cable and resulting in a "back release". The
length of cable between the attachment ring and the drogue parachute was considerably shorter than that recommended and increased the
probability of an uncommanded release of the tow cable.
'
24 Mar 84
Piper 28-R201 VH-FSD
Private
842101 5
1930
Dubbo NSW 102SW
30
243
128
Instrument rating class 4
While cruising at 6000 feet on a night VMC flight the pilot encountered a heavy rain shower. During an attempted 180 degree turn the aircraft
entered a spiral dive and in the recovery from this dive the aircraft was evidently overstressed. After diverting to Parkes the pilot flew to his planned
destination on the following day. The damage sustained by the wings was not detected until a subsequent daily inspection.
13 May 84
Beech 36 VH· TYZ
Commercial
8411 023
1509
Beaudesert SSW
23
439
65
Instrument rating class 4
Soon after settling in the cruise at 2000 feet, the pilot noticed that the fuel flow was lower than expected. He selected rich mixture but the fuel flow
began to fluctuate markedly and the MAP reduced. A short time later the engine began to run roughly, accompanied by a rise in oil pressure and a
further reduction in MAP. The pilot elected to return to the departure point. Engine power became inadequate for level flight and the pilot selected
an emergency landing area. The aircraft came to rest after running through two barbed wire fences.
The engine failed due to long term lack of lubrication to several bearings caused by the rotation of two main bearing shells which covered oil
supply galleries. The damage to the main bearing assemblies was such that the cause of bearing shell rotation could not be established.
09 Jui 84
Cessna R182 VH·UCN
Commercial
8441 020
1 553
Borroloola NT 33SE
36
3985
3
Instrument rating class 4
As the aircraft was climbing through 8000 feet the engine suffered a complete loss of power. After unsuccessfully attempting to restore engine
power, the pilot selected a small clearing in which to land. During the landing attempt, the aircraft floated the 160 metre length of the clearing
before colliding with trees.
A substantial amount of foreign matter and corrosion had accumulated in the carburettor float bowl, main strainer bowl and auxiliary fuel pump.
Although the fuel filters were clean the corrosion was evidence that water had been held within the system for some considerable time. It is
probable that during the climb some of the foreign matter blocked the carburettor main jet.
17 Jui 84
1 705
Mooney M20F VH-CGJ
Narrabri NSW
8421032
Instrument rating 1st class or class 1
with instrument rating
The pilot was receiving a check flight as part of a biennial flight review. He was appropriately endorsed for retractable gear and constant speed
propeller aircraft, but had not previously flown the Mooney type. After touchdown on the third of a series of touch-and-go landings the pilot
inadvertently raised the landing gear instead of the flap. The aircraft slid to a halt on the runway .
29
2520
Commercial
113
05 Aug 84
Piper 25-235/A1 VH·BSB
Private
8431021
1543
Woodbury Tas
38
360
239
None
The student glider pilot had carried out three previous flights during the day. Her instructor had informed her that she was at a suitable stage of
training to be introduced to practice emergency procedures. After sighting her training log book, the instructor for the final flight left the glider to
speak to the pilot of the tug aircraft. The instructor returned to the glider and preparations for take-off were then continued.
Witnesses observed that the tug and glider became airborne and subsequently carried out normal turns to position the aircraft ona downwind leg
at about 500 feet above ground level. The tug aircraft was then seen to waggle its wings sharply three times. Almost immediately this aircraft
assumed a steep nose-down attitude, its tail apparently being pulled into a vertical position by the tow rope which was still attached to the glider.
The glider then also assumed a steep nose-down attitude and both aircraft spun or spiralled towards the ground. The tow rope was released from
both aircraft, but neither pilot regained control before impact with the ground.
The subsequent investigation did not disclose any defect or malfunction with either aircraft that might have contributed to the development of
the accident.
During glider towing operations when the pilot of the tug waggles the aircraft wings it is a signal to the glider to immediately release from the tow.
This "wave-off" signal would normally be given when the tug pilot detects some malfunction or when the glider is sufficiently far out of position
behind the tug to affect the tug pilot's control of his aircraft.
On this occasion it was considered likely that the instructor in the glider had arranged for the tug pilot to simulate an emergency by giving a wave·
off signal. However, there was no evidence to suggest that the student pilot had received a formal briefing on the actions and procedures required
in the event of the emergency. The wave-off signal was observed to be given in the normal position relative to the strip for such training
manoeuvres to be performed. The reason for the subsequent loss of control of both aircraft could not be determined, however it was evident that
when the aircraft released the tow rope there was insufficient height remaining to permit recovery to normal flight.
Probable Significant Factors
There was insufficient evidence available to determine the precise cause of the accident. Nevertheless, the following were considered to be
probable factors in the development of the occurrence.
1 . The gliding instructor and the tug pilot arranged to give the student a practice emergency.
2. The student was inadequately briefed on the actions required for the emergency.
3 . When the wave-off signal was given the glider did not immediately release from the tow.
4. Control of both aircraft was lost at too low a height to permit recovery.
vi I Aviation Safety Digest 126
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
05 Aug 84
Czech Blanik L13 VH·GGF
Glider
843102 1
1543
Woodbury Tas
33
232
19
None
The student glider pilot had carried out three previous flights during the day. Her instructor had informed her that she was at a suitable stage of
training to be introduced to practice emergency procedures. After sighting her training log book, the instructor for the final flight left the glider to
speak to the pilot of the tug aircraft. The instructor returned to the g lider and preparations for take-off were then continued . '
Witnesses observed that the tug and glider became airborne and subsequently carried out normal turns to position the aircraft on a downwind leg
at about 500 feet above ground level. The tug aircraft was then seen to waggle its wings sharply three times. Almost immediately this aircraft
assumed a steep nose-down attitude, its tail apparently being pulled into a vertical position by the tow rope which was still attached to the glider.
The glider then also assumed a steep nose-down attitude and both aircraft spun or spiralled towards the ground. The tow rope was released from
both aircraft, but neither pilot regained control before impact with the ground.
The subsequent investigation did not disclose any defect or malfunction with either aircraft that might have contributed to the development of the
accident.
During glider towing operations when the pilot of the tug waggles the aircraft wings it is a signal to the glider to immediately release from the tow.
This "wave-off" signal would normally be given when the tug pilot detects some malfunction or when the glider is sufficiently far out of position
behind the tug to affec t the tug pilot's control of his aircraft.
On this occasion it was considered likely that the instructor in the glider had arranged for the tug pilot to simulate an emergency by giving a wave·
off signal. However, there was no evidence to suggest that the student pilot had received a formal briefing on the actions and procedures required
in the event of the emergency . The wave-off signal was observed to be given in the normal position relative to the strip for such training
manoeuvres to be performed. The reason for the subsequent loss of control of both aircraft could not be determined, however it was evident that
when the aircraft released the tow rope there was insufficient height remaining to permit recovery to normal flight.
Probable Significant Factors
There was insufficient evidence available to determine the precise cause of the accident. Nevertheless, the following were considered to be
probable factors in the development of the occurrence.
1 . The gliding instructor and the tug pilot arranged to give the student a practice emergency.
2. The student was inadequately briefed on the actions required for the emergency.
3. When the wave-off signal was given the glider did not immediately release from the tow.
4. Control of both aircraft was lost at too low a height to permit recovery.
23 Aug 84
Beech H18 VH-PDI
Commercial
8421040
1835
Bankstown NSW
26
897
23
Instrument rating 1st class or class 1
The aircraft returned to its departure aerodrome after suffering a complete electrical failure. Emergency extension of the gear was completed, but
during the landing roll the nose leg retracted, which resulted in the nose and propellers striking the runway.
A written checklist was not used prior to departure and the generators were evidently not switched on . The electrical panel and the generator
warning lights are obscured by the control column. Emergency gear and flap extension is achieved using the same w inder which is placarded
"Flaps-push handle in , Gear-pull handle out" . Investigation revealed that although the flaps were in the fully down position the gear was only part of
the way through its extension cycle.
01 Sep 84
Piper 25-235/A1 VH-MYE
Private
8431026
1 505
Korumburra 4SSE
28
226
25
None
The pilot had been engaged in glider towing operations for about four months, and had completed 108 towing flights.
During the afternoon the pilot had carried out two aerotow flights without incident. On the accident flight a normal take-off and transit to the north
side of Korumburra township was made. The glider was released at a height of 2000 feet above ground level and the tug aircraft then turned and
tracked towards a right base leg position for the south west landing strip at Leongatha.
Not all of this flight was observed, but two witnesses noticed the aircraft descending in a spin to the right. It appeared to recover briefly, with the
nose being raised above the level flight attitude, however a spin to the left then commenced . This spin continued until the aircraft disappeared from
sight, but the wreckage distribution and impact marks indicated that the pilot had been able to stop the rotation in the last moments of flight. It was
evident that insufficient height remained to effect a full recovery.
A detailed inspection of the wreckage did not disclose any defect or malfunction with the aircraft, its engine or systems that might have
contributed to the development of the accident.
It was considered unlikely that the pilot had deliberately entered a spin on his return to the airfield. The aircraft type was not approved for
spinning, and the spin characteristics of this particular two seat conversion are unknown. There was no evidence available to determine how or why
the spin situation developed. It was apparent that the pilot had succeeded in partially recovering from the initial spin , however the recovery
technique being employed did not prevent a spin in the opposite direction .
04 Sep 84
Piper PA38-1 12 VH·HAV
Student
8421045
1037
Bankstown NSW
44
30
30
None
Following a period of dual instruction the pilot was authorised to carry out her second solo circuit and landing. During the landing flare the aircraft
ballooned and subsequently touched down on the nosewheel. The aircraft bounced and on the next touchdown the.nosewheel broke off, the nose
gear leg was displaced and the aircraft slid to a halt on the runway.
The pilot's previous training flight had been conducted approximately one month prior to the accident. After misjudging the landing flare, the pilot
persisted with the landing attempt instead of going around.
24 Sep 84
Cessna 172M VH-WYK
Commercial
8411041
1 610
Burleigh Stn. 17 N
21
860
7 45
Instrument rating class 4
After arriving at the property that morning, the pilot commenced mustering operations. The operations were conducted between 50 feet and 300
feet above ground level throughout the day and all manoeuvres performed appeared normal to ground observers.
Later in the afternoon a witness reported that he observed the aircraft perform a steeper than normal climb before diving towards the ground. The
aircraft subsequently impacted the ground in a steep nose down , wings level attitude, bounced, then slid forward for 13 metres before the left w ing
struck a tree.
Examination of the wreckage did not reveal any defect with the aircraft that could have contributed to the accident. It is probable that the pilot was
fatigued after a long day and that he inadvertently allowed the aircraft to stall at the top of the climb. Insufficient height was then available to allow a
recovery to be effected.
24 Sep 84
Wittman W8 VH-MGO
Private
8451026
1040
Munglinup WA 7E
56
700
450
None
The aircraft touched down in a three-point attitude and after a short ground roll, became airborne over a small rise. The second touchdown was in a
left wing low attitude and the propeller struck the ground. The aircraft swung to the right then the left wing struck the ground turning the aircraft to
the left. It slid a short distance before coming to rest with the left gear leg collapsed .
It was ascertained that during production of the aircraft, the welding of the combined engine mount and main undercarriage unit was not to the
required standard. The weak welds failed during the landing roll on the unprepared strip.
Aviation Safety Digest 126 I vii
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
29 Sep 84
Cessna 210-N VH-AOI
Private
8451027
1620
Beverley WA 3W
41
250
16
None
Prior to the first flight on the day the pilot inspected the fuel tanks of the aircraft and estimated they contained 225 litres of fuel. On that basis he
planned a flight of 155 minutes duration. Approaching the second last turning point of the flight the engine stopped. The pilot selected the other
fuel tank, power was restored and a diversion made to the nearest suitable airfield. On final approach to that airfield the engine stopped again. The
aircraft was landed heavily in a paddock and the nose gear leg torn off.
The aircraft had been parked on sloping ground which could account for the over-estimation of fuel contents. As the flight was conducted at
3000 feet, no attempt was made to lean the mixture although fuel consumption was increased 24 per cent by running the engine at full rich
mixture. Suitable forced landing areas were overflown enroute to the diversion aerodrome because the pilot thought that the fuel gauge was in
error. The aircraft stalled during an attempt to prolong the glide to a more suitable area.
12 Oct 84
1200
Commercial
400
8421053
36
3000
Agricultural class 2 w ith
flight instructor and instrument
During spraying operations the engine suffered a partial power loss. The pilot initiated dumping of the hopper load but was unable to prevent the
aircraft from striking the ground heavily. The landing gear collapsed and the aircraft slid for about 50 metres before coming to rest.
The reported power loss had occurred during a procedure turn, the latter portion of which was downwind. No fault was subsequently found with
the engine, however it was considered likely that the aircraft was affected by downdraughts in the lee of a hill. When dumping was initiated, the
pilot's left sleeve had probably caught on the throttle lever and pulled it towards the closed position .
Piper 25-235 VH-CCS
Blayney NSW 15SW
30 Oct 84
Beech 58 VH-DTU
Commercial
8421 058
1015
Mcintyre's Field
22
1800
200
Instrument rating 1st class or c lass 1
After a normal circuit the aircraft crossed the threshold at 85 knots. The pilot advised that the wheels locked as soon as braking was applied.
Intermittent brake application had little effect in slowing the aircraft and as the pilot considered that insufficient strip remained to permit a go-around
he attempted to ground loop the aircraft. II slid off the side of the strip and collided with a fence before coming to rest.
The strip surface was very slippery as a result of overnight rain. Misty rain was still falling as the pilot made his approach and touched down about
one quarter of the way along the strip. The pilot had not determined the last point al which a go-around could be commenced and persevered with
the landing attempt beyond the point where a go-around could have been safely accomplished.
04 Nov 84
Bellanca-8-KCAB VH-UOO
Commercial
8421060
1130
Wallacia NSW
27
265
60
Instrument rating class 4
After a normal approach in calm wind conditions the aircraft bounced following the initial touchdown. A number of bounces then occurred before
the pilot was able to regain control of the aircraft. At this time he assessed that there was insufficient strip remaining to stop the aircraft or to safely
go-around. A ground loop was attempted, during which the right landing gear collapsed.
The strip length was about 120 metres longer than that required for a normal landing. The aircraft was being operated in excess of the maximum
permitted landing weight. 'After the initial bounce the pilot persisted with the landing attempt and evidently did not consider carrying out a go-around
until the aircraft was too far along the strip for this manoeuvre to be performed with safety.
11 Nov 84
Cessna U206F VH-EKJ
Private
8441025
11 56
Broken Hill 80S
51
448
67
None
The pilot noticed a low oil pressure reading and decided to land at a strip he had just overflown. As he turned the aircraft toward the strip the engine
began to vibrate and backfire and it was shut down. The aircraft touched down 150 metres short of the strip boundary fence. After running through
this fence the aircraft continued for a further 280 metres before coming to rest on the strip. Initial inspection revealed that the engine crankcase
had been punctured by a connecting rod.
Inspection of the engine revealed that the crankcase had been punctured by the connecting rod of the number 4 piston. The connecting rod
assembly had been subjected to excessively high temperatures due to a lack of lubrication. The cause of the lack of lubrication to the assembly
could not be determined. After the engine had failed, the pilot continued with his attempt to land at the nearby station strip although a closer and
more suitable area was available.
17 Nov 84
De Hav DH 84 VH-AQU
Private
8441027
1025
Beachport SA 1OE
45
4 74
None
After refuelling , the pilot found one of the tanks contaminated with water. The fuel was drained from the tank and clean fuel added. No
contamination was found in the subsequent check of the fuel in the tank. The aircraft was then washed using a high pressure water hose. During
the following flight, the engines began to run roughly and the pilot decided to carry out a landing in a paddock. The surface of the paddock was
rough and the aircraft bounced heavily and groundlooped, collapsing the right gear.
The investigation revealed that water had been present in the fuel system for some time. Because of the design of the fuel system ii is not
possible to drain the lowest point of the fuel tank while the aircraft is parked . It is probable that the engine rough running was caused by a
combination of contaminated fuel and a sticking valve.
01 Dec 84
Amer Air 5A VH-SZV
Private
841 1055
0854
Beaudesert 40S
39
229
36
None
As he approached the Macpherson Range the pilot was forced to fly around some hills in order to stay below the cloud base. After crossing a ridge
line where the gap beneath the cloud was about 300 feet, the pilot was confronted by a higher ridge. He subsequently advised that the aircraft
could not out-climb the terrain and he carried out a controlled entry into the jungle canopy about 200 feet below the top of the ridge. Both wings
were torn off however the cabin area came to rest intact.
02 Dec 84
Pitts S1 VH-IGZ
Private
8441028
0859
Emkaytee NT
44
2195
700
Instrument rating class 4
Al the conclusion of an aerobatic display the pilot performed an inverted circuit, rolling upright as the strip was sighted on final. On short final the
aircraft descended below the desired flight path and the pilot applied power. The aircraft responded but the right gear leg caught on a power line 5
metres agl and 330 metres from the threshold. The aircraft struck the ground in a steep nose down attitude and came to rest inverted.
The inverted circuit had been conducted at between 50 and 100 feet above the tops of the trees .
02 Dec 84
Piper 28-140 VH-RVL
Private
8431036
151 O
Longwarry Vic
38
290
275
Instrument rating class 4
The pilot was to conduct two spot landings from practice forced landing approaches commenced at 2000 feet. On the first approach an
undershoot developed and power was used to complete the landing. The second approach was high and touchdown was made about half way
down the 730 metre strip. A go-around was initiated but the engine failed to develop significant power. The take-off was then abandoned and the
aircraft struck a dirt bank and drain beyond the end of the strip.
It is probable that carburettor icing caused the lack of engine response when the go-around was initiated. Braking was inhibited by wet grass
covering the remainder of the strip available.
viii I Aviation Safety Digest 126
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
04 Dec 84
Burkhart ASTIR CS VH-KYN
Glider
8441 030
1919
Whitwarta SA
66
750
200
Glider
After travelling 15 metres during a winch-launch the left wing-tip contacted the ground. The instructor immediately assumed control of the
glider and applied right rudder and aileron but the left wing entered an oat crop on the edge of the strip. The tip then dug into soft soil, causing
the glider to cartwheel and impact heavily on its nose 120 metres from the take-off position and 35 metres to the left of the centreline.
The crop on the edge of the 15 metre wide strip was about 1 metre high and the glider's wing span was 17 .5 metres. The student was
experiencing difficulty learning to control the aircraft during take-off and following w ing-tip contact with the ground both the instructor and the
student stated that they made control inputs. Conditions during the day were hot and the instructor had been on duty for nearly ten and a half
hours.
09 Dec 84
Czech Blanik VH-GIK
Glider
8441 031
1400
Monarto SA
25
9
4
None
It was reported that the flight proceeded normally until during the flare. The glider was lined up with the strip , but during the hold-off ii drifted to
the right and touched down on the edge of the marked , 50 metre wide strip. The landing roll continued off the runway and the starboard wing
struck a tree 20 metres from the edge of the strip.
The landing was conducted in 4 to 8 knot crosswind conditions. During the hold-off the student pilot applied excessive rudder when aligning
the aircraft with the strip prior to touchdown.
24 Dec 84
Schleicher ASW 19 VH-GWL
Other (Foreign, Military, etc.)
8441032
1900
Waikerie SA 7E
28
310
3
Unknown or not reported
Following an outlanding the pilot arranged an aerotow. The take-off was commenced into wind and up a rise. The glider became airborne but on
breasting the rise, the tug pilot aborted the take-off as trees and a fence appeared closer than expected . The tug aircraft which had just
become airborne turned left and the left wing tip struck the ground before the aircraft came to rest. The glider pilot released the tow but the
glider's right wing tip contacted the ground then the fence before the glider impacted the ground beyond the fence.
Before commencing the aerotow the pilot of the tug aircraft had estimated that sufficient distance was available for the take-off to be
completed . He did not measure the distance available nor consult the aircraft performance chart. The chart indicated that with the prevailing
conditions, insuffic ient distance was available to successfully complete the take-off.
24 Sep 84
Piper 25-235 VH-WGC
Commercial
844 1032
1900
Waikerie SA 7E
46
1170
15
Instrument rating 1st class or class 1
Following an outlanding the pilot arranged an aerotow. The take-off was commenced into wind and up a rise . The glider became airborne but on
breasting the rise, the tug pilot aborted the take-off as trees and a fence appeared closer than expected. The tug aircraft which had just
become airborne turned left and the left wing tip struck the ground before the aircraft came to rest. The glider pilot released the tow but the
glider's right w ing tip contacted the ground then the fence before the glider impacted the ground beyond the fence.
Before commencing the aerolow the pilot of the tug aircraft had estimated that sufficient distance was available for the take-off to be
completed. He did not measure the distance available nor consult the aircraft performance chart. The chart indicated that with the prevailing
conditions, insufficient distance was available to successfully complete the take-off .
27 Dec 84
Piper PA34-200T VH-STN
Private
844 1033
161 O
Adelaide SA
19
350
3
None
The pilot reported that as the aircraft descended through 300 ft on final approach, windshear and an increase in the rate of descent was
experienced. He applied power to arrest the rate of descent then reduced the power setting to idle. The aircraft landed heavily and bounced,
the pilot attempted to take corrective action but the aircraft again landed heavily. The aircraft was taxied to the parking area where the damage
was noted.
The endorsement completed earlier that day, was the pilot's first flight in a civil aircraft and this flight was his first solo in a multi-engined
aircraft. Although endorsed on a heavy transport type , the pilot was projected into an environment beyond his level of experience, due to the
single pilot workload being higher than that to which he was accustomed . The approach was steeper and 30 knots faster than recommended
and a high power setting was used . The approach was made into the sunset and visibility was further impaired by a dirty windscreen.
842 1074
Instrument rating 1 st class or class 1
with instrument rating
Following a normal circuit, the aircraft touched down with the landing gear doors open and the gear partly extended . The gear collapsed as the
aircraft slid to a halt on its under-surface .
The pilot had diverted so that a telephone call could be made and he decided to land well down the runway to save time taxying. He forgot lo
select the gear down until immediately prior to touchdown.
27 Dec 84
1321
Cessna 310R VH-FFA
Moruya NSW
62
12500
Commercial
5000
06 Jan 85
Piper 28-R200 VH-WIN
Private
852 1002
1245
Bourke NSW
73
1305
6 10
None
As the pilot was attempting to locate the airstrip at his destination, he noticed some of the aircraft's electrical equipment had failed . He decided
to proceed to Bourke and land. On arrival over Bourke the pilot selected the gear down but did not obtain any indication of the gear position. He
then manoeuvred the aircraft in an effort to assist gear extension but did not attempt to use the manual override system . The aircraft was landed
with the gear retracted .
The alternator and engine pulleys were out of alignment resulting in the drive belt becoming detached. The handling notes were carried in the
rear luggage locker, out of reach of the pilot and because the operation of the emergency gear lowering system could not be remembered a
wheels up landing was made.
12 Jan 85
Czech Blanik L 13 VH-GBT
Glider
852 1004
1655
Tumut NSW
34
12
None
Following a dual check and a short solo flight, the pilot was authorised to conduct a soaring flight of not more than one hour's duration. The
glider was subsequently launched from an aerotow after take-off into a light northerly wind. II was observed soaring in the vicinity of the
aerodrome within an estimated height band of 3000 to 6000 feet above ground level. During the flight the w ind on the ground changed to
become a gusty south-westerly at about 1O to 15 knots . The shade temperature was 36 degrees celsius and localised areas of turbulence
were reported by other pilots .
The pilot did not return for a landing for approximately two hours, despite the pre-flight briefing. When he returned , the aircraft was positioned
for a landing into the north, apparently without reference to the changed wind conditions . During final approach the glider was seen lo pitch
down into an almost vertical dive. It struck the ground some 200 metres before the strip threshold and came to rest inverted .
Subsequent examination of the wreckage did not reveal any defect or malfunction that might have affected the pilot's ability to safely control
the aircraft. It was apparent that the glider had been in a normal wings level approach configuration immediately before the pitch-down which
occurred at a height of about 100 feet above ground level. It was considered possible that the aircraft could have been affected by turbulence,
or that the pilot may have suffered from heat stress and fatigue. However, insufficient evidence was available to enable the precise factors in
the occurrence to be determined.
Aviation Safety Digest 1 2 6 I ix
�Date
Time
Aircraft type & registration
Location
Age
14 Jan 85
0900
Cessna 180K VH-SAA
Bundaberg Old
59
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
Commercial
24
8511002
Flight instructor grade 1 or 2 with
instrument rating
During the landing roll the aircraft started to veer right. The pilot under check applied sufficient rudder to correct the swing but then applied
excessive left rudder and considerable power and the aircraft swung sharply left. The left wing and elevator tips contacted the ground whilst the
instructor was regaining control. The pilot under check had not flown a tail wheel aircraft for five months.
2720
18 Jan 85
Bell 206B VH-WNB
Commercial - helicopter
8551002
0748
Karratha WA 37N
46
6 162
634
None
After establishing level flight with an external sling load , the pilot felt a bump from the rear of the helicopter. He corrected the accompanying pitch
change and then a second bump was felt. The load was jettisoned and immediately the helicopter began yaw to the right. The pilot was unable to
regain control before the helicopter struck the ground.
The pilot had not flown helicopters for two years and although he had recently completed a check flight, slung operations were not covered. On
this operation the pilot was substituted for another pilot who was unavailable. The load carried on this run was identical to loads previously carried,
but much lighter. The pilot elected to use the same cruise speed as for the heavier loads. The load became unstable and encountered the tail
boom. Upon its release the load slid back and was struck by the tail rotor, breaking off one blade and snapping the drive shaft.
24 Jan 85
Beech 58 VH-EZB
Commercial
8551 004
1450
Halls Creek WA
24
1664
220
Instrument rating 1st class or class 1
During the start sequence for the left engine, a loud bang was heard and the fuel agent noticed a fire under the aircraft. He advised the pilot, who
secured the engine and along with the passengers, evacuated the aircraft. The fire was extinguished but the left wing damaged .
During the prior refuelling operation fuel was seen to be leaking onto the ground beneath the left engine from a known leak within the left wing .
However the left engine was started in situ. Subsequent investigation revealed cracks due to age decay in the left wing outboard fuel cell vent line
joints.
26 Jan 85
Cessna 172N VH-WND
Commercial
81521006
1302
Albury NSW
41
386
132
Instrument rating class 4
Following a report of engine rough running a section of an exhaust valve was found to have broken away. A new cylinder assembly including an
exhaust valve was fitted but on take-off for a test flight the engine suddenly suffered a substantial loss of power. During the subsequent forced
landing the aircraft ran through a fence and came to rest in a ditch. Two cylinder assemblies were found to have suffered internal damage and
pieces of the missing section of the previously replaced exhaust valve were found within the induction system.
Although the engine had been ground run by the engineers it had not been tested to full power. As the pilot was asked to limit taxiing and idling
times to avoid overheating the new cylinder, engine run-up and pre-flight checks were conducted whilst taxying. Take-off was commenced 230
metres along the 1900 metre runway and this was the first full power demand made on the engine since its repair. At about 250 feet agl a power
loss was experienced, full flap was not used for the forced landing attempt and the aircraft struck the ditch which was 2 74 metres past the end of
the runway.
27 Jan 85
1410
Pitts S1 VH-DDS
lake Eppalock Vic
Commercial
114
8531002
Instrument rating class 4
with flight instructor
A low level aerobatic display was being conducted over the lake. Towards the end of the display the pilot performed four snap rolls followed by a
steep climb and stall turn. Although the display was to be conducted not below 500 feet agl the aircraft was recovered from the last snap roll at an
estimated 150 feet agl. Despite this low recovery height the pilot persisted with the climb and stall turn manoeuvre. While attempting to recover
from the subsequent dive he stalled the aircraft at too low a height to avoid impacting the water.
31
784
06 Feb 85
Transav PL 12 VH-MLJ
Commercial
8531003
1023
Deloraine Tas 8E
45
9900
500
Agricultural class 1
At the conclusion of spraying operations the pilot initiated a climb enroute to his destination. Almost immediately, the engine failed completely and
the pilot was committed to a landing in a barley crop. During the landing roll the nosewheel was broken off and the aircraft overturned.
The aircraft was at about 100 feet agl when the engine failed and the most suitable area available required that the landing be made downhill on a
soft surface. A skid to the right after touchdown caused the nosegear to fail. The cause of the engine power loss could not be established.
07 Feb 85
De Hav DH82-A VH-BFW
Private
8531004
1520
Alberton Vic
49
905
820
None
After a short flight in the local area the pilot made a long low final approach towards the intended landing point. During the approach the pilot
temporarily forgot that powerlines crossed the flight path. The aircraft collided with the wires, which were 68 feet agl, and struck the ground in a
vertical nose-down altitude about 800 metres from the landing area.
08 Feb 85
Piper 25-235 VH-TOX
Commercial
8531005
1550
Wilmot Tas 2S
37
1800
1OOO
Agricultural class 2
The pilot was conducting the last of his spraying tasks for the day . The paddock had an uphill slope and there were two groups of tall trees at the
uphill end. The first run was conducted up the slope but during the subsequent pull up and procedure turn strong turbulence was encountered. The
left wing struck branches in one group of trees, control was lost and the aircraft struck the ground heavily. The fuel tank ruptured, a fire broke out
and the wreckage was completely gutted.
The spraying was commenced in strong wind conditions and the procedure tum was executed in the lee of the trees. When the turbulence was
encountered the pilot chose to fly between the two stands of trees but insufficient clearance existed for the passage of the aircraft. The pilot
advised that his workload during the day had been high and that he did not like spraying this particular paddock because of its slope and the
adjacent trees.
17Feb85
Piper28·151VH-RUZ
Private
8531011
1900
Moorabbin Vic
26
150
150
None
The pilot was turning into the parking area, intending to taxy between aircraft parked in parallel rows. As the turn was completed the left wing lip
struck the spinner of the aircraft at the start of the left hand row. This aircraft was undamaged , however the wing tip of the taxying aircraft was
pushed rearwards with consequent damage to the rear spar fuselage carry-through member.
During the tum into the parking area one of the passengers interrupted the pilot's concentration by pointing out that the parking position from
whence they had departed, was still vacant. The pilot did not notice that the aircraft had moved almost 2 metres to the left of the taxiway guideline
until the collision was imminent.
x I Aviation Safety Digest 126
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
17 Feb 85
Bede BD4 VH-ABD
Private
8541 003
1440
Tanunda SA 5SSW
43
370
120
None
The pilot was attending a fly-in to display his aircraft. Because he was concerned about the length of the strip he was endeavouring to
touchdown at the threshold. During the final approach, he became aware that the airspeed was reducing below the optimum,and applied some
power, however, the aircraft struck the ground heavily about 10 metres before the strip threshold. The pilot applied full power and carried out a
go-around. As a result of the ground contact the nosewheel was torn off.
The pilo t was advised of the situation by ground observers and elected to divert to Parafield. During the subsequent landing the nosegear leg
collapsed.
18 Feb 85
Piper 28- 161 VH-UMB
Commercial
8521013
11 15
Deniliquin 22NE
42
3280
1500
Flight instructor grade 1 or 2
At the conclusion of the dual training segment of the flight the Instructor decided to demonstrate a forced landing sequence . Descent was
continued to a very low height, and during the go-around the aircraft struck a fence at the approach end of the selected paddock. Control was
maintained and a safe landing was subsequently carried out at the destination aerodrome.
20 Feb 85
Piper PA23-250 VH-JEN
Commercial
851 1008
0845
Palm Island Qld
26
1460
90
Instrument rating class 3
The pilot stated that when braking was applied after touchdown, the aircraft did not decelerate normally. A go around was carried out, and after
the aircraft became airborne, the nosewheel struck a fence. As a result the nosewheel became misaligned and the nose gear collapsed during
the subsequent landing at Townsvilie.
Upon arrival the pilot had to orbit for 5 minutes to allow a rain squall to pass. Without overflying the strip he assessed that the w ind favoured a
landing direction which placed him presently in a wide base position. Due to standing water on the grass strip and a tailwind component,
deceleration was minimal. By the time a go around was initiated the aircraft had entered an area of long grass. The flaps were left in the landing
position during the go around , this further increased drag and added substantially to the ground run.
21 Feb 85
1800
Cessna A 188-A1 VH-KVK
Trangie NSW 11 SE
Commercial
97
852 10 14
Agricultural class 2 with
flight instructor
On commencing the clean up run, the wire deflector on the aircraft struck a single power line. The top section of both the fin and rudder were
severed from the aircraft which was subsequently landed at the departure strip without further damage.
The pilot had been briefed on the crop lo be sprayed and on the location of power lines in and around the paddock. After cleaning up the
other edges , the final run was commenced with the aircraft flying parallel to the main power lines. The pilot temporarily forgot the presence of
the single wire running from the main line into the paddock.
47
8112
24 Sep 85
Beech 76 VH-BGY
Private
853100 7
1807
Moorabbin Vic
36
121
20
None
Shortly after a normal touchdown directional control problems were experienced and the left wing began to lower. The pilot applied full power
and carried out a go around . The pilot advised the tower that the left mainwheel tyre was probably flat, and subsequently positioned the aircraft
for another landing. Normal gear down and locked lights were illuminated, however after touchdown the left gear leg began to collapse and the
aircraft slewed off the side of the runway.
The left gear retracted due to insufficient overcentre action on the side-brace lock. This was compounded by wear in the side-brace centrepivot. Both of these potential problem areas had been address by the aircraft manufacturer in relevant Service Instructions. Compliance with
these instructions was not mandatory and the aircraft had not been modified.
05 Mar 85
Bell 47-G3B1 VH-ANG
Commercial - helicopter
8541004
1220
Mt Riddock Sin. NT
28
1215
1085
None
During mustering operations the pilot landed on two occasions in order to visually check the amount of fuel remaining. Although the second of
these checks revealed an estimated endurance of 20 minutes, the pilot elected to carry out a further short mustering task before returning to
the refuelling area about 4 kilometres away. While enroute to the refuelling point the engine suddenly stopped. The pilot entered auto-rotation
but had to manoeuvre to avoid trees and the aircraft subsequently landed heavily.
The investigation revealed that the aircraft was serviceable but the engine had failed due to fuel exhaustion. The last landing to check the fuel
quantity was probably made on sloping ground and could account for the overestimation of fuel remaining , although below required reserves, at
that time.
09 Mar 85
Mooney M20J VH-MVO
Private
8521017
1625
Ban kstown NSW 13W
59
820
350
None
The aircraft was cruising at 1500 feet agl when a large bird was struck. Substantial damage was caused to the right w ing of the aircraft,
however the pilot subsequently carried out an uneventful landing.
09 Mar 85
Cessna A188B-A1 VH-PLU
Commercial
8521016
1845
Gundagai NSW
39
3800
1 500
Agricultural class 1
Spray runs were being carried out under a power line when the aircraft cable deflector struck the line. The cable rode up the cable deflector
and severed the top of the rudder from the aircraft. The aircraft was landed in a paddock without further damage.
09 Mar 85
Glasflugel Mosquito VH-FQR
Glider
8511O1 1
1615
Jondaryan Old
66
773
143
Glider
Deteriorating soaring conditions resulted in the pilot landing at a strip close to his intended destination. The landing was uneventful and the pilot
arranged for an aero-tow launch . During the take-off roll the left wing of the glider dropped slightly and became caught in long grass. The glider
veered violently to the left, became airborne for a few metres then swung to the right and left again before the pilot could release the tow. The
glider sustained several cracks in the mid-fuselage area.
09 Mar 85
Wittman W8 VH-SLA
Private
85310 10
1130
Mt Beauty Vic
52
604
50
None
Enroute to his planned destination the pilot flew around the Ml Beauty area for several minutes. He had not previously landed at the strip and
had not intended to on this occasion, however after watching other aircraft operating a decision to land was made. A go-around was made from
the first approach as the aircraft was high on late final. Touchdown from the subsequent approach was made well into the strip and the aircraft
bounced. A go-around was initiated but while turning to avoid trees the left wing struck the ground and the aircraft cartwheeled, coming to rest
inverted.
Witnesses reported that during the go-around the aircraft adopted a steep nose high attitude but did not climb. The turn left was initiated
whilst the aircraft was in this attitude. No fault was subsequently found with the engine or associated systems. The pilot had probably
established the aircraft in a steeper than normal attitude because of the presence of a hill adjacent to the strip.
A viation Safety Digest 126 I xi
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Record Number
Rating
13 Mar 85
Hiller UH12-E VH-FFT
Commercial - helicopter
8511012
1 500
Charleville 146NE
38
4000
2000
Instrument rating 1st class or class 1
The pilot had landed the helicopter in a clearing in order to refuel from drums carried in the aircraft. During the subsequent take-off into the
strong wind prevailing, downdraft was experienced as the aircraft approached a heavily timbered area. A turn was carried out to avoid the trees
but the combined effects of the downdraft and the downwind turn resulted in the helicopter touching down heavily. The impact forced the
landing skids rearwards, bending the associated vertical support members.
Private restricted
8521021
14 Mar 85
Cessna 182F VH-WPC
63
186
18
None
1345
Bankstown NSW
The pilot was carrying out a series of practice circuits and landings. On this particular approach the aircraft bounced after touchdown. The pilot
applied some power in an attempt to cushion the subsequent touchdown, however the aircraft struck the ground heavily and bounced again. A
go-around was conducted and was followed by a normal landing. Post-flight inspection revealed damage to the nose strut, the engine firewall
area and the propeller.
15 Mar 85
Grumman 164A VH-SLK
Commercial
8511013
0830
Jondaryan Old 30N
39
11700
5500
None
The pilot had sprayed the paddock using a series of runs in an east-west direction, parallel to power lines along the property boundary. He then
decided to do a clean-up run in a north-south direction, but forgot about the presence of the power lines. During the pull-up at the end of the run
the aircraft flew into the wires and subsequently struck the ground heavily 219 metres further on.
19 Mar 85
1718
Piper 30 VH-RBT
Coifs Harbour NSW
Senior commercial
8521 020
90
Instrument rating 1st class or class 1·
with instrument rating
When the gear was selected down ii did not fully extend and the gear circuit breaker tripped. Initially the circuit breaker could not be reset nor
could the gear be lowered using the emergency system. The circuit breaker was subsequently reset and a gear down indication obtained.
Shortly after touchdown the aircraft yawed until it was travelling backwards. The tailskid struck the runway and the aircraft came lo rest after
turning through a further 90 degrees. The right main wheel was found to have turned through 90 degrees because the scisst>r linkage arms
had become disconnected.
A castellated nut and its retaining split pin was found lo be missing from the bolt which joins the scissor linkage arms. The reason for the loss
of these items could not be positively established.
23
2550
Private restricted
8541005
19 Mar 85
Beech V35 B-MK2 VH-ILO
7
None
40
63
1530
Robe SA 25SE
The aircraft was parked about 40 metres from its hangar. After carrying out a normal daily inspection the pilot boarded the aircraft with the
intention of conducting some practice circuits and landings. As soon as the engine was started ii developed full power, the aircraft accelerated
rapidly and collided with a truck which was parked in the hangar.
The pilot had not flown for four months and most of her experience was on a more basic aircraft type. The pre-flight and engine start
sequences were attempted without using the checklist. After the engine had started the pilot tried to reduce power but did not depress the
throttle-lock of the vernier control. It is possible that the cabin heat control, which was selected on, could have been mistaken for the park
brake, which was not set, as they are both situated in the same panel.
23 Mar 85
1600
8551007
Flight instructor grade 1 or 2 with
instrument rating
The student pilot was undergoing a conversion onto the aircraft type. As part of the conversion, the instructor closed the throttle and requested
the student to demonstrate a forced landing. At about 600 feet agl, the instructor, being satisfied with the exercise, advised the student to goaround. The throttle was opened but the engine did not respond. The instructor took control but was unsuccessful in his attempts to restart the
engine. The aircraft was landed in a paddock and ran through a fence.
The exercise was carried out conforming to the checklist requirements, one of which was to switch the fuel boost pump on . Investigation
revealed that the engine would not idle with the pump on. The engine had been out of service, unpreserved, for 17 months and the fuel
regulator diaphragm was sticking to its guide and seal assembly causing the engine to run rich at idle and stall. Although the instructor took
control at 600 feet, attention was diverted from the forced landing to restarting the engine.
Piper 28-R180 VH-KIE
Mundijong WA
51
8076
Commercial
32
Know your systems: the mixture
control
Aircraft engine mixture controls are often coloured red to indicate that they should be used with caution.
Correct use of the mixture control in flight for adjusting the air-fuel (A-F) ratio is one of the most important
items in the operation of engines. Proper leaning of the mixture provides smooth, efficient engine
operation, more power for a given power setting, and best range and endurance; on the other hand, misuse
of the mixture control can seriously damage or ruin an engine.
The following occurrence is typical of those associated
wi th incorrect operation of the mixture control.
After only a brief flight , the engine of a Piper PA28
suffered a partial loss of power, which was accompanied
by severe vibration. The pilot completed a precautionary
landing as quickly as possible.
On investigation it was found that the number 2
exhaust valve head had separated from the valve stem.
There was evidence of valve 'necking' (which means
narrowing and, therefore, weakening of the valve) , while
there was also excessive clearance between the valve stem
and guide. Both of these conditions are generally
indicative of excessive, localised 'hot spots' within an
engine, which in turn are related to an incorrect A F
ratio. In this instance this was attributed to the use of
improper fuel leaning procedures.
As is the case with any aircraft system , pilots will
appreciate its purpose better if they understand how it
works.
Air-fuel ratio
The air- fuel ratio is the ratio between the weight of air
and the weight of fuel that goes in to an engine's
cylinders. Gasoline will burn in a cylinder if mixed with
air in a ratio of between 8 parts air to 1 part fuel and
18 parts air to 1 part fuel, although in very general
terms th e best power range may be considered to be
between 12:1 and 16:1, with 15:1 being the accepted
theoretical best chemically correct air to fuel mixture. In
many aircraft engines the most practical air to fuel
ratios vary between 11.5:1 and 14:1, with the rich
mixture used at high power output and lean mixtures
customarily used at lower cruising powers.
The key role in controlling the mixture ratio is played
by the carburettor or fuel injection system . Because
gasoline cannot ignite or burn when in the liquid state,
it must first be vaporised and mixed with the correct
amount of air. The car burettor or fuel injector measures
the approximate quantity of fuel to be supplied to the
engine, atomising and mixing the fuel with air in the
correct proportion (i.e. A-F ratio) before the mixture
enters the cylinders. This proportioning must be done
accurately regardless of the speed, power setting and
altitude at which the engine is operating.
Unlike car engines, aircraft engines must operate over
a wide range of altitudes. Carburettors and fuel injection
systems are normally calibrated for sea-level operations,
which means that the mixture of air and fuel will be
correct for the power selected at sea level with the
mixture control in the 'full rich' position.
As an aircraft climbs to higher altitudes the air
density decreases, that is, the given volume of air will
not weigh as much as it would at a lower altitude .
Therefore, the weight of air entering the
carburettor/injector will decrease, although the volume
STOICHIOMETRIC MIXTURE
Student
8511014
24 Mar 85
Piper 38-11 2 VH-FLA
17
39
39
None
1415
Archerfield Old
On final approach, the pilot reported that the aircraft encountered a strong headwind. At about 30 feet above the ground the aircraft began to
sink and the stall warning sounded. The pilot applied some power and selected a higher nose attitude, but the aircraft landed heavily on the
mainwheels, bounced onto the nosewheel and the propeller struck the runway. The aircraft ran off the runway before the pilot was able to
regain control.
\J
15:1
EXCESS FUEL
rEXCESSAIR
1003 POWER
26 Mar 85
Zenith CH200 VH-MAD
Private
8531012
081 5
Dixons CreeK Vic
66
617
31 0
None
Initial touchdown occurred about one third of the way along the 518 metre strip. A slight bounce followed and as soon as the aircraft had
settled on the ground again the brakes were applied. There was no noticeable retardation and the pilot attempted to go around. The nosewheel
struck a gable marker just prior to the boundary fence, and the left mainwheel contacted the top strands of the fence. The fuselage was
punctured by a fence post and the pilot abandoned the lake-off attempt. An inspection of the strip immediately after the occurrence revealed a
very heavy dew on the short, thick grass surface.
30 Mar 85
Cessna 152 VH-TNX
Student
8531 013
1125
Melton Vic
17
12
12
None
During the pilot's second solo flight the aircraft bounced twice on landing. The pilot persisted with the landing attempt and applied forward control column
pressure after each bounce. Following the second bounce the nose wheel struck the ground heavily and was torn off and the aircraft overturned.
31 Mar 85
Cessna 172M VH-TCB
Private
8551008
1730
Moonera WA
64
1491
326
None
After encountering navigational difficulties, the pilot became concerned that he may not reach his destination before last light. He decided to land on a
road near a homestead. While the aircraft was being taxied after landing, the pilot misjudged the distance from a metal pole and the right wing struck
the pole.
xii I Aviation Safety Digest 126
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FUE L -AIR RATIOS VS. POWER AND TEMPERATURE
Aviation Safety Digest 1 2 6 I 1 3
�I
I
11
I
I
remains the same. The amount of fuel metered by the
carburettor/ injector depends on the volume , not the
weight, of air. As altitude increases the amount of fuel
entering the carburettor/ injector will remain
approximately the same for any given throttle setting.
Thus, since the same amount (weight) of fuel is metered
by the carburettor but there is a lesser amount (weight)
of air, the air-fuel mixture becomes richer as altitude
mcreases.
To compensate for this , aircraft engines are equipped
with manual and/ or automatic mixture controls.
The mixture control
This leads to the central question: what does the
mixture control do? The answer is that it compensates
for the decreased air density by metering the amount of
fuel which passes through the main jet in the
carburettor or to the injectors. It is used to reduce the
amount of fuel flow and maintain the correct A- F ratio.
This in turn reduces fuel consumption and provides
smoother engine operation. For the majority of GA
aircraft this leaning of the mixture is effected manually.
Engine considerations
Two important factors associated with the A- F ratio are
those of engine operating temperature and power
output. Temperature, recorded as cylinder head
temperature (CHT) , is indicative of the 'burning process'
taking place within the cylinders , while aircraft
performance parameters such as speed , range and
endurance are of course directly related to engine power
output.
The relationship of the A- F ratio to power and
temperature is shown in Figure 1. Note that the A-F
ratio of 15: 1 is known as the stoichiometric mixture,
which is the chemically correct mixture for all of the
fuel and all of the air to burn.
This lea ds to the question of fuel distribution. In a
carburettor-equipped engine the intake manifolds and
induction pipes are used to distribute the fuel and air
charge to the various cylinders. Those cylinders which
are the furthest from the carburettor often receive a
slightly leaner mixture than those closest to it. Because
of this unequal fuel distribution the temperatures within
the cylinders will tend to vary. T his can be important
when the pilot uses the mixture control to lean the
mixture.
If a pilot uses extremely lean mixtures without
reference to proper instrumentation, localised 'hot spots',
coinciding with the areas of leanest mixture, can be
created. Depending on where the temperature probe for
the CHT gauge is located, cockpit indications in such
circumstances may show that the engin.e is operating at
normal temperatures, when in fact an exhaust valve and
seat, for example, are overheating.
This apparently was the case with the fractured valve
stem which caused the engine failure in the incident
described at the start of this article .
Note that while fuel injection provides better fuel
distribution than carburettion , fuel injected engines can
still be lean ed excessively.
Two other asp ects of mixture control raised in Figure
14 I Aviation Safety Digest 12 6
1 need elaboration; these are the conditions of excess air
or fuel , and 'best power' .
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Figure 1 shows that for mixtures less than the
stoichiometric, there is more air in the cylinders than is
needed for complete combustion , while on the right side
there is more fuel than necessary.
For normally aspirated (i.e. unsupercharged) engines,
recommended operating range C HTs are always
maintained by selecting a mixture richer than the
stoichiometric mixture. The same technique is almos t
invariably used for supercharged engines although , if
approved by the manufacturer, some large supercharged
engines may be operated in the ' excess air' range , as the
amount of excess air in such engines will act as a
coolant. For example, if the manual mixture control of a
supercharged engine is moved towards the lean position,
CHTs will be hottest when the A- F ratio is 15: 1, but as
the mixture is leaned still further , temperatures will
return to cooler, more proper values. To reiterate , this
should be done only with the manufacturer's approval ,
while unsupercharged small aircraft engin.es should never
be leaned to this extent as excessive temperatures will
result.
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MAX TEMP
PEAK EGT
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Best power mixture
The ' best powe r' mixture is that A-F ratio at which the
most powe r can be obtained for a given throttle setting .
By de finition, 13.5 :1 A F ratio is 'lean best power ' and
12. 5:1 A- F ratio is 'rich best power', i .e. any mixture
between 13.5:1 and 12. 5: 1 is a ' best power ' mixture.
This represents an optimum setting at which to operate
an engine.
Instructions fo r adjusting the mixture control to
achieve a ' best power' setting are given in Pilots'
Operating Hand books.
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Excessively lean mixture
As the occurrence described at the start of this article
illustrated , using a mixture that is too lean can seriously
damage an engine . In addition to causing roug h
running, back firing, over -heating or sudden 'cutting
out' , excessive leaning can also initiate detonation and
pre-ignition .
Detonation. Detonation is the spontaneous explosion of
the unburned charge in the cylinders after normal
ignition. If the temperature and pressure of the unbumt
portion of the A- F charge r each critical values ,
combustion will begin spontaneously . The result is a
sudden and violent explosion - i.e. detonation - of the
charge rather than the relatively slow burning of normal
combustion.
Continued operation when detonation is present can
result in dished piston heads, collapsed valve heads ,
broken rings ; or eroded portions of valves , pistons and
cylinder h eads. Com plete and sudden engine failure can
result.
Since it is very important to avoid detonation, it is
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protection from its possible occurrence must be provided
by:
• engine design; and
• adherence to correct engz"ne handling procedures by
pilots.
,
P re-ignition. Pre -ignition is the uncon trolled firing of
the A F charge in advance of normal spark ignition. I t is
caused by the presence within the combustion ch amber
of an a rea which is incandescent (red hot) and which
serves as an ignitor in advance of normal ignition. Preignition m ay result from a glowing spark plug electrode
or exhaust valve , or perhaps a carbon or lead particle
hea ted to incandescence.
As with detonation , such operating factors as high
intake air temperatures, lean mixtures , high m anifold
pressures and improper cooling are likely to set the stage
for pre-ignition. Pre-ignition may sta rt deton ation and ,
conversely , deton ation m ay start pre -ignition because of
the high temperatures involved.
Pre -ignition can be just as destructive as deton ation .
Rich mixture
Before discussing m anual leaning techniques , an
important point concerning rich m ixtures must be made.
O pera ting with the mixture more rich than required is
not necessarily ' being kind ' to the engine - in fact, the
opp osite could well be the case. O perating an
unsupercharged engine at high altitude with an
excessively rich m ixture not only wastes fuel , but the
power produ ced will be less than that which is available
at that altitude with the mixture correctly leaned. Surplus
fuel is rarely required for combustion chamber cooling at
high altitudes, and the use of mixtures that are too rich
usually only introd uces other problems su ch as sp ark
plug fouling. Spark plugs are designed to operate within
certain heat ranges in order to fu nction properly and
operate without fou ling . An excessively rich m ixture will
lower the temperature of the spark plug centre electrode
below norm al which, in turn , will lead to the formation
of car bon an d lead deposits . T hese deposits are
electrically conductive and when they reach a sufficien t
depth, the electric current will flow through the d eposit
rather than 'jumping the gap' in the spark plug to ignite
the air and fuel charge. It is essential, therefore , tha t an
A- F r atio is main tained which will provide sufficient heat
in the combustion chamber to vaporise any deposits
which m ay form on the ceramic centre of the spark plug.
TOO
LEAN
....· - - - - L E A N
MIXTURE
RICH---...
~
Figure 2
well to consider the principal factors which cause it. As
far as the pilot is concerned, those over which he can
exercise control are the octane ra ting of the fuel, mixture
and, where applicable, manifold pressure.
Usually detonation cannot be recognised from the
cockpit through sound or engine roug hness ; therefore ,
Manual leaning techniques
Depending on the power settings used and engine
han dling limitations contained in P ilots' O per ating
Handbooks/Aircraft O wners' Manuals , engines may be
operated at lean mixture settings corresponding to
m aximum p ower and, where specifically permitted , best
econ omy . The three basic recommended techniques for
manual leaning are the tachometer/ airspeed in dicator
method, the fuel flow or pressure gauge m ethod, and the
exhaust gas temperature m ethod .
Tachometer/airspeed indicator m ethod. The
tachometer and , in favou rable conditions, the airspeed
Aviation Satety Digest 126 I 15
�indicator, are useful guides in establishing these mixture
settings. For aircraft with fixed pitch propelle rs, the
throttle should be set for the desired cruise RPM as
shown in the Owners' Manual, and the mixture then
gradu ally leaned from full rich until either the
tachometer or the airspeed indicator gives a maximum
reading. At peak indication , the engine is operating in
the maximum power range. It should then be enriched,
to prevent excessive temperatures, in accordance with the
manufacturer's instructions. In the case of constant speed
propellers, the mixture should be leaned until the
airspeed indicator reading peaks or there is a significant
power loss or evidence of rough running. Again, the
mixture should then be enriched until the engi ne runs
smoothly an d power and airspeed are fully restored, and
approved operating CHTs achieved.
Where the use of cruise powers at best econ omy
settings are permitted, the mixture is first leaned from
full rich to maximum power, then leaning is slowly
continued until the engine begins to run roughly or
power and airspeed decrease rapidly. When either
occurs, the m ixture should be enriched sufficiently to
obtain an evenly firing engine or to regain most of the
lost airspeed and engine RPM. Some engine power and
airspeed must be sacrificed to achieve a best econ omy
mixture setting.
Fuel flow or pressure gauge method. For aircraft with
fuel -injected engines, the mixture can be leaned
manually by using the fuel flow or pressure gauge.
Settings for a given cruise power and altitude may be
obtained from tables or other data provided by the
aircraft manufacturer, or the indicator may be marked
with the correct flow for each power setting. For any
given set of conditions, the pilot need only lean the
mixture to the specified fuel flow value to obtain the
correct mixture.
Exhaust gas temperature m ethod. One of the most
accurate methods of establishing correct mixture
strengths is to use an exhaust gas temperature gauge.
This device measures the temperature of the exhaust
gases and in this way indicates the proportions of the
air- fuel m ixture. To establish the maximum power
setting by this m eans, the mixture is leaned to the point
at which the temperature reading reaches a maximum ,
and is then enriched again, to achieve a fixed
temperature drop. Whenever best econom y operation is
permitted by the aircraft owners ' handbook or the engine
manual, the mixture may be leaned to peak EGT. The
accompany ing graphs (Fig ure 2) show that that peak EGT
occurs essentially at the rich edge of the best economy
mixture range. They also show that operation at peak
EGT not only provides. minimum specific fuel
consumption but also 95- 96 per cent of the engine's
maximum power capabilities for a given engine speed
and manifold pressure.
Aircraft with turbo-charged engines frequently have an
exhaust gas temperature pick-up installed in the turbine
inlet to measure turbine inlet (exhaust gas) temperature.
The procedures for leaning these engines, using turbine
inle t temperature, are slightly differen t, and the
technique and reference temperatures published in the
owner's handbook should be strictly observed. For these
installations, it is important that the m aximum turbine
inlet temperature specified by the manufacturer is not
exceeded.
16 I Aviation Safety Digest 126
General considerations
Many pilots believe they should never lean the mixture
for operations below 5000 feet. The theory behind this
practice is that, by the time an aircraft with an
unsupercharged engine has climbed to 5000 feet, the
power output will have dropped to about 75 per cent at
the throttle setting normally used for clim b, and at this
power, there is less likelihood of an engine being
damaged through improper leaning techniques, since the
cylinders and other engine parts are operating at lower
temperatures . The fact of the matter is, however , that
unless specifically prohibited in the owner's manual, the
mixture may be leaned at any height , provided the
power setting is below 75 per cent.
The mixture must always be returned to full rich
before increasing power, and then reset. It should also be
reset for any change in altitude or the application of
carburettor heat. It is good practice always to select fullrich mixture before joining the circuit for a landing.
Other distractions near the ground can cause the mixture
setting to be overlooked and a pilot could encounter
serious difficulties with detonation or overheating if a goaround became necessary.
When setting the mixture by means of an exhaust gas
temperature gauge, it is not sufficient me'rely to adjust
the mixture to obtain a given temperature reading based
solely on previous experience. Not only are there likely
to be characteristic variations in exhaust gas temper ature
from engine to engin e, but ch anges in calibration of the
indicating equipment can also lead to inadvertent overleaning of the mixture unless the correct 'temperature
drop' method is always used.
Similar considerations apply also to setting the mixture
using a fuel flo w gauge in that, while the specified fuel
flows have a built-in margin of safety under normal
operating conditions, unless the gauge remains accurate
within close limits, the engine could be receiving a
mixture that is either too rich or too lean. Thus, while
determining the correct mixture by means of a fuel flow
or exhaust gas temperature gauge is clearly preferable to
setting it ' by ear', the accuracy of settings established by
these methods still depends on the cockpit gauges and
sensing units remaining close to correct calibration at all
times.
Finally, regardless of the leaning technique used,
careful consideration m ust also be given to such factors
as any reduction in engine power, actual fuel
consumption, engine cooling, smoothness of operation
and other relevant en gin e limitations. As a final check,
once the mixture has been set for cruise operation, the
cylinder head temperature and oil temperature gauges
should be constantly monitored. Although these two
instrumen ts h ave slow response times, the trend of their
readings is a useful guide in maintaining correct mixture
strengths and preventing engine damage.
Conclusion
For engines equipped with manually operated mixture
controls (which means most types of modern light
aircraft engines) , the pilot has a particular responsibility
to understand the fundamentals of engine operation and
to use the mixture control safely a nd intelligently •
Helicopters and ground fires
One of the most regular - and yet at the same time avoidable - accidents in Australian aviation is that of
helicopters ' setting fire to themselves'. As the brief narratives of three such accidents which occurred in a
recent 1 O month period illustrate, the same causal factors are almost always present.
• A pilot carrying out an aerial survey landed in an
area of long, dry grass to 'take a breather'. The
engine was left idling and the hot exhaust ignited the
grass on the port side, suddenly and intensely. The
pilot vacated the helicopter rapidly and watched it
burn ou t from a safe distance. Although he had 2450
hours total flight time, 450 hours on type and a
Commercial Helicopter Licence, he had not been
aware of this p erennial helicopter problem.
• While involved in his first solo mustering flight a
young pilot decided to take a short rest and landed in
a spinifex-covered clearing. The helicopter's exhaust
set fire to the spinifex; in the ensuing conflagration
the aircraft was destroyed.
• T he helicopter had landed in long grass to drop off a
passenger. However, before the passenger could
disembark, the aircraft's hot exhaust started a grass
fire. Finding himself confronted by a wall of flames
the passenger retreated across the cockpit, and in
doing so prevented the pilot from taking any action
to try to save the machine. With the helicopter alight
both men escaped and watched it burn out.
Comment
Fortunately no-one was hurt in any of the three
accidents summarised above, although the potentidl
clearly is considerable: for example , the pilot of the
helicopter in the accompanying illustration (t aken from
another 'self-immolation' accident) sustained serious
burns.
Given the persistent occurrence of this type of
accident it seems, to state the case mildly, extraordinary
that, either supervisors and senior pilots apparently do
not brief all of their employees on this subject, or, some
pilots apparently choose to ignore the advice when it is
given. That advice is simple- helicopter pilots need to
be careful where they land •
Notable quote
As a postage stamp which lacketh glue, so are the
words of caution to a fool; they stick not, going in
one ear and out the other, for there is nothing
between to stop them.
Courtesy of Flight Safety Bulletin
Aviation Safety Digest 126 I 17
�Dynamic rollover
position (perhaps caused by fuel sloshing). A narrow
landing-gear tread or , if on a ship, a rolling deck,
compounds the problem .
A rollover can happen in calm air if the stick is being
held off-centre enough during takeoff, but a crosswind
can make it even more likely . Even in a strong
crosswind, there is little or no main-rotor flapping due to
non-symmetrical aerodynamics until the collective is
raised for takeoff, then the non -symmetrical
aerodyn amics produce flapping (sometimes referred to as
' blow back'). In addition, as the shaft is tilted against the
springiness of the landing gear, the increased angle of
attack generates even more flapping . Thus, if the pilot is
not compensating for the disc tilt with cyclic pitch, he
will find the upsetting effects increasing at the same time
that th e res toring effects are decreasing.
Recovery techniques
Start of a possible rollover
A Bell 206B had been parked adjacent to a refuelling
platform 60 millimetres high. As the pilot was bringing
the aircraft to the hover prior to takeoff, the right skid
contacted the platform. The pilot attempted to correct
with cyclic but the helicopter rolled to the right and came
to rest on its right side near the platform .
The contact between the skid and the edge of the
platform had induced dynamic rollover. Evidently the
pilot had not identified the problem in time to take the
app1 ~priate corrective action of lowering the collective
control in order to place both skids on the ground.
Aerodynamic forces
In flig ht, high bank angles are generally of no great
concern because control around the roll axis is usually
where the helicopter is at its best. On the ground,
however, even a mod~rate bank angle can be disastrous
if it is enough to tip the machine over.
T he primary helicopter upsetting moments are
attributable to rotor flapping, with the resultant tilted
rotor thrust and hub movements as shown in the
diagram. Sometimes tail-rotor thrust and wind on the
fuselage also contribute. T he moment tha t keeps the
helicopter from tipping over comes from the weight
acting between the two wheels or skids. If the helicopter
rolls on its landin g gear, this stabilising m oment
diminishes; it goes to zero if the aircraft ever rises on one
wheel far enough to put the centre of gravity (CG) right
over that wheel. If the helicopter is sitting on a slope, it
already h as a reduced restoring moment and a lateral CG
18 I A v(ation Satety Digest 1 2 6
Component of th rust
paral lel to shaft
t
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• ,,.... Component of thrust
perpendicular to
shaft
Crosswind
Weight
Rear view
In a normal takeoff of most single-rotor helicopters , one
landing gear comes off the ground first but, since this
happens just as the aircraft becomes airborne, this action
is not associated with a rollover. If, however, one
landing gear comes off the ground with only partial
thrust on the rotor, a rollover may be starting. In this
situation, the pilot might try to hurry the takeoff by
raising the collective. This is usually a mistake since the
increased thrust in the same direction resu lts in an
increase of the upsetting moment.
Another choice is to apply lateral control to put the
gear back on the ground - but this action may be too
late, especially if the initial motion came as a surprise . If
an appreciable rolling velocity has developed, it will take
a second or two to stop the motion and by this time the
helicopter may have tilted irrevocably beyond its critical
tip-over angle. This is especially true on the deck of a
ship rolling in the same direction as the helicopter.
A reduction of collective pitch to get both landing gears
firmly on the ground is the accepted cure for a dynamic
rollover but this should be done gently. If the helicopter is
dropped too fast it m ight bounce on the gear that was in the
air and start rolling in the other direction.
Although pilot distraction or inattention is usually
required to set up the conditions for a dynamic rollover,
some accidents have occurred when the liftoff was
attempted with one landing gear still stuck to the ground
by mud, ice or a tiedown.
The possibility that a pilot may cause a helicopter to
rollover on the ground is increased by very stiff hingeless
rotors, since even at flat pitch a little out-of-trim cyclic
pitch can produce a high, upsetting hub moment. In the
Lockheed AH-56 Cheyenne , to discourage the pilot from
holding the stick off-centre , a device was installed th at
stiffened up the control centring springs whenever the
aircraft had its full weight on the landing gear. The
device was deactivated on takeoff as ' squat switches'
sensed the partial extension of both landing gear oleos •
( T he last two sections of this article reprinted by permission of Rotor &
Wing International. © PJS Publications Inc 1981, R W Prouty author.)
In brief
During a dual training exercise in a C 152 with a
student pilot a series of circuits had been satisfactorily
completed. At about 450 ft when climbing away the
engine note suddenly changed and the rpm fell
significantly. The instructor took control and landed
without damage on the sterile area beside the runway
(contractor plant was working on that end of the
runway).
The air filter had disintegrated and a loose piece
had become lodged in the carburettor , partially
blocking the airflow. A new filter was fitted and
engine performance was returned to normal. The
filter was very dirty and clogged. The operator's fleet
was checked and all were given new filters . The report
commented that this was an example of the generally
poor standards of maintenance of these particular
aircraft. (NB: this was a UK occurrence).
Air filters should be kept clean and
uncontaminated, as collapse of this simple item can
have very serious consequences. This also makes
economic sense since obstruction of the free flow of
clean air will result in an inefficient, excessive fuelburning engine. This can be demonstrated by keeping
careful fuel records following fitment of a new filter
(on a car or an aeroplane).
*
*
The pilot of a PA31 was on approach to a UK airport
behind a Boeing 73 7. At the outer marker he reduced
speed to 110 knots to give a greater separation . The
approach was on the centreline and glideslope with
only light atmospheric turbulence. At 300 ft he was
cleared to land; landing flap was set and speed
reduced to 95 knots crossing the threshold. Suddenly
at about 25 ft a severe buffet was experienced and the
aircraft rolled violently to the left through 25- 30
degrees until application of full aileron, rudder and
asymmetric power controlled the roll. The aircraft
then managed to climb away from the ground,
experiencing two more slight buffets with the rolling
effect diminishing in strength. A normal landing was
made further down the runway.
The pilot felt that had an overshoot been initiated
when the buffet was first experienced the aircraft
would have climbed above the vortex. His company
training highlights the problems of wake turbulence
and suggests a high approach path to a non-limiting
runway as one solution. In this case it was not
possible as ATC had issued a 'land after' clearance
with the B737 clearing slowly two-thirds down the
runway e
*
Aviation Safety Digest 1 2 6 I 19
�It all began one Saturday morning: having recently
finished my Unrestricted Private Pilots Licence I had
completed several solo flights as well as some reasonably
long distance flights with my wife as passenger.
I had been checked on the Cessna 172 and 172RG
and was that day completing my load check on the
l 72RG prior to flying to Dubbo the next day with my
wife, cousin and his wife.
The following morning bright and early we departed
from Bankstown and had an uneventful run until our
reporting point abeam Burrendong Dam (I always prefer
to fly FULLSAR/FULL REPORTING). Upon transmitting our
position report I was unable to receive any response. It
was only when we were within sight of Dubbo airfield
that two-way communications were established, and then
only on COM 2 - by trial and error I determined that
the COM 1 selector switch was inoperative.
On landing at Dubbo we encountered a strong
crosswind gust, landing heavily on the right main gear
wheel, and on inspection at the tie-down bay it was
noticed that the tyre was unserviceable.
We visited the Western Plains Zoo as planned to see
our recently sponsored wallaby and on our return to the
field were advised that a replacement tyre would not
arrive until the following m orning. My passengers
caught the 3 pm XPT and arrived at Parramatta 7 hours
later while I checked into a motel and arranged to
attend to some business and see our other major
customer in the area the following morning.
The next day, h aving concluded my business, I filed a
flight plan, refuelled the Cessna and, h aving confirmed
that the COM 1 was still unserviceable, opted to return to
Bankstown using COM 2 only.
Departure and en route reporting was OK ·until
Bathurst when the weather began to look dirty despite
an earlier forecast indicating VMC over Katoomba.
20 I Aviation Safety Digest 12 6
I flew around the 'hill' at Bathurst at approximately
4500 feet with clear visibility to Katoomba, although low
cloud appeared to be sitting on the ranges at some
distance to either side - it almost appeared that there
was an archway cleared over Katoomba for met
Sucked into the trap I proceeded towards Katoomba
when without warning the cloud dropped within what
seemed to be about 30 seconds. On turning in cloud to
return to Bathurst I noticed that my senses had betrayed
me and that instead of completing a level rate 1 turn , I
was instead losing height at the rate of 1OOO feet per
minute in a 60 degree bank to the right! That's when I
saw the treetops ... (still quite some distance below).
My immediate response was to curse m yself for failing to
heed instructions to rely on the instruments and not my
senses.
FULL RICH
FULL PITCH
FULL POWER
LEFT RUDDER
LEFT AILERON
WINGS LEVEL
BACK PRESSURE ON THE CONTROL COLUMN
BEST CLIMB SPEED, POSITIVE RATE OF CLIMB, CONFIRM
GEAR AND FLAP UP
I switched the transponder from 'standby' to 'on' and
squawked ident.
Sydney this is Kilo Delta Echo on climb through 5000 feet
approximately ten miles west of Katoomba; I have
inadvertently entered cloud and am not certified for IMC
(by this time I knew I was clear of terrain . . . all I had to
do now was maintain controll) require assistance ... am
attempting to level out at 5000 feet and then maintain a
heading, will await further instructions.
endurance as being approximately 180 m inutes.
That's when the radio started to play up, and I lost
communications with Sydney.
The aircraft was fitted with Autopilot, 2 VORs, DME
and ADF. With the radio playing up I elected to forget
the VOR/ Autopilot and tried instead to monitor the
Bankstown NDB. However, I was having enough trouble
maintaining level flight and attempting to set a course
without also experimenting with instruments I was
familiar with only at a theoretical level.
I found that I was receiving several frequencies at
once, with Sydney being over-ridden by Bankstown on
118.l and 121. 1.
I turned the whole set off and on again several times
and tried to complete the standard inflight emergency
radio checks as best I could.
All of a sudden I had Bankstown loud and clear
telling me to switch to another frequency . . . and there
was Sydney, clear as a belll
When I re-established contact with Sydney I had
settled down and was able to respond readily to their
rapid request for another ident. and almost immediately
a change of heading (this time I was located as being 25
miles north-west of Sydney - obviously in the RAAF's
airspace at Richmond). Unbeknown to me there was a
twin on an IFR flight to Wellington which had been
instructed to climb to 7500 to allow me clearance, but
which could not be contacted after I had been
instructed to climb to 8000 feet - about the time my
radio played up. The controllers app aren tly could only
stand and watch as our blips converged on their
radarscope.
The controller then advised that I was to continue on
my heading at 8000 feet and that they would radar
vector me to the vicinity of Camden and re-assess the
situation ... H ell, I was ready to fly to Canberra if
necessary!
On approaching Camden I came across a 'bubble' in
the clouds; it was clear from about 8500 down to ground
level within a diameter of approximately 1.5 miles.
Immediately I commenced a turn and advised Sydney
th at it was my intention to commence a steep
descending turn into VMC. After some hesitation they
agreed. Ignoring my training I commenced a power-on
descent and very soon found myself descendiqg at a
speed in excess of 150 knots with 60 degrees of bank .
WINGS LEVEL
THROTTLE SET
PROP SET
FUEL SELECTOR BOTH
COWL FLAPS CLOSED
CARBY HEAT ON
10 DEGREES OF FLAP AT 130 KIAS
SELECT DESCENT ATTITUDE
CONTROLLED DESCENT . ..
Down again and into VMC at approximately 3500 .
sighted 2FC tower and Bankstown Field . . . Controller
stayed with me through descent on course to 2FC and
then very professionally said 'Change frequency now to
Bankstown on 118.1 '. My automatic response was 'Kilo
Delta Echo'.
With a very strong sou therly I was d irected to land on
runway 18 and subsequently directed to report to
Operations.
*
*
*
This series of events underscores the ease with which
difficulties can be encountered through a 'She'll be right'
attitude.
After flying blind for a total of 25 minutes in
Sydney/ Richmond Controlled Air Space I must say that
in hindsight I should have had the radio thoroughly
checked at Dubbo and should have exercised more care
in determining the cloud base over Katoomba.
I walked away from this one m ostly by staying calm
. . . the first minute or two were the most harrowing as
I was unsure that I was climbing clear of obstructions;
however, once into cloud , concentration on instrument
scan was paramount in saving the day.
I plan to start Class 1 training soon •
Sydney then advised me to climb to 8000 feet in an
attempt to get above cloud and advised that they would
clear the frequency and attempt to radar vector me to
an area safe for descent; they also ascertained m y
Aviation Safety Digest 126 I 21
�Incorrect ground handling procedures
During disassembly of a C 172 for transporting, t he
horizontal stabilizer front spar doubler plate at the
fuselage attachment point was found to be cracked in
four places. All cracks originated a t the lighte ning hole
and varied in le ngth from 12mm to 18mm (see Figure
1). There also 'Was buckling of the stabilizer centre
section skin and spa r . Airworthiness engineer s believed
that this d a mage may have been caused by incorrect
ground handling .
Some m anufacturers of tr icycle u ndercarriage aircraft
approve alternative methods of manoeuvring of the
aircraft on the ground whe n a towbar is unavailable.
One su ch m eth od involves pressing down at the
horizontal stabilizer front spar adj acen t to the fuselage to
raise the nosewheel off the ground . With the nosewheel
clear of the ground the aircraft is then turned by
pivoting it abou t the main wheels. For example, the
Cessna Model 172 series service manual details th is
technique.
It is important to note that if th is method is used,
downward pressure should be a pplied at no location
other than the junction of the horizon tal stabilizer front
spar and the fuselage, as the application of for ce at
locations outb oard of this point will generate excessive
leverage which could result in structu ral damage.
r•
~
~ - ·''·
-· ·I~
-
-
.
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v
The p referred method of ground m an oeuvring is
depicted at Figure 2 •
Brush up on your aeronautical knowledge
FIG. 2
(Courtesy Canberra Aero Club.)
J.. __....
BECAUSE of the harsh comments made by the CFI in the last club magazine about the technical
knowledge of members fronting for biennial flight reviews, he was asked to devise a 'standard quiz'.
Here it is. The pass rate will remain at zero per cent.
1 . Determine to an accuracy of one litre the holding fuel remaining after a flight from A to B, a distance of
three standard isogonals, given the following:
fuel flow. 1 5mb per hour
density latitude, 40 per cent
QNH, standard constipation rates.
2. Calculate the time you will see sunrise on 4 December in a leap year if you are flying east from J to K
with 7 oktas of northerly drift and at right angles to the winter equinox (ignore CLIAS and LSALT
factors).
3. If your answer to question 2 was ~95 ° 15'S, intercept nearest VOA radial and convert it to troy ounces
of 1 OOLL Avgas.
4. You are flying a TAS course from A to Busing Adriatic QFE and a 120v headset. You find a disused
flight level at right angles to track.
a) What action ·should you take immediately?
b) Would all POB need 1 00 per cent oxygen?
5 . You are navigating with a Lamberts Incredible Chart. It has a scale of 1 :3000 as measured by a Douglas
Rectum.
a) Would the topography have a concise or adverse curve?
b) Would the curve be constant, given that the earth is a shereblat obroid?
c) Which standard calisthenic will be east/west and will it be straight or corrugated?
6. Your aircraft has a compass swing at 180 ° 20'W and has since been flown three times. The depreciation
card shows an accretion of 6 ° below ISA on the headings north to west. Given a fixed card DME, what
would be the relative bearing to your destination after two nautical yards of ale? Can you complete this
flight on a great circle track without an SSB HF on HP?
7. Convert the velocity of triangles into mb3 and multiply the result by your groubschpeken measured in
degrees Cerberos.
...-· L
-....
BFR QUIZ NO. 1
22 I Aviation Safety Digest 12 6
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Aviation Safety Digest, number 126 (Spring, 1985)
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126
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1985
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�Preflight preparation
Contents
3 Preflight preparation
5 Fatigue on the midnight express
A pilot suffering from sleep deprivation and a cold sunk
into a low arousal state during a midnight express freight
run.
7 Hung up
A parachutist was suspended upside down beneath a
Cessna 206 when a leg strap of her harness hooked over
a triangular seat belt anchorage as she exited the aircraft.
8 Safe operation of light twins
12 Quick conversions
Two small charts designed to be used with a pocket
calculator to convert fuel figures from volume units to
weight units.
13 Pin that airspeed
If you are faced with an outlanding, maintenance of
adequate airspeed is of paramount importance.
14 Drum refuelling
16 Wasted resources
As a result of navigational problems a pilot made a
precautionary landing at dusk and spent the night on the
ground. Because he had not cancelled SAR an extensive
search involving nine aircraft and costing, by one
estimate, $40 OOO, was activated.
17 Airborne direction finding
This article describing an actual airborne Direction
Finding (D/F) intercept and escort was prepared by ATC
officers from Townsville. (Reader contribution.)
18 Attention to detail
The incident discussed in this article highlights a number
of the factors often associated with the wrong grade of
fuel being pumped into an aircraft's tanks.
19 Ells and false alarms
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation In pursuance of Regulation 283 of the Air Navigation
Regulations and is publlshed by the Austral/an Government
Publishing Service. It Is distributed free of charge to Australian
licence holders (except student pilots), registered aircraft owners and
certain other persons and organisations having an operational Interest
in Australian civil aviation.
i
j,
Unless otherwise noted, articles In the publication are based on
Australian accidents or Incidents.
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
The Publications Distribution Officer
Department of Aviation
P.O. Box 18390, Melbourne, Vic. 3001
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Inquiries and notifications
of change of address should be directed to:
Mail Order Sales
Austral/an Government Publlshing Service
G.P.O. Box 84, Canberra, A.G. T. 2601
Subscriptions may also be lodged at AGPS Bookshops in the capital
cities.
Reader contributions and correspondence on articles should be
addressed to:
The Director
Bureau of Air Safety Investigation
P.O. Box 367
Canberra City, A.G. T. 2601
© Commonwealth of Australia 1985
ISSN 0045-1207
R841878 Cat. No. 84 2492 X
Printed by Finepress Offset Printing Pty Ltd
49 Railway St, Yennora, N.S. W. 2161
20 Helicopter ground resonance
The covers this quarter illustrate the winning entries from the Digest's photographic competition. On
the front is the winner in the Best Photograph Category, a De Havilland Float Beaver off Pittwater,
N.S.W. This entry was submitted by Mr R. Israel of Sydney, who used a Pentax 6 x 7 cm, 150
mm lens, Fujicolour.
The back cover is the winner in the Best Safety Theme Category, submitted by Mr C. Atkins of
Melbourne, using a Pentax 6 x 7 cm with a Takumar 35 mm fisheye lens, Fujicolour. Mr Atkins'
photograph depicts, through the use of streaks of light originating from lamps attached to the pilots'
hands, a visual representation of the control ergonomics involved during an approach flown in
TAA's B727 simulator.
BASI would like to thank both the many hundreds of aviation enthusiasts who submitted entries and
the competition's sponsors, Maxwell Optical Industries Pty Ltd, the Australian distributors of Nikon
cameras and photographic equipment.
2 I Aviation Safety Digest 125
..
A few seconds after his Beechcraft M35 Bona nza
becam e airborne the pilot selected the undercar riage
UP. Unbeknown to the pilot , the em ergen cy la nding
gea r e xtension handle , which is located be hind the
front sea ts , was engaged. Thus, as the undercarriage
retraction cycle started , the .eme rgen cy extension
ha ndle began to rotate rapidly . ·
The front rig ht se at was not occupied and its safety
belt ha rness ha d not been secure d . T he buckle of the
lap sectio n. was h anging down loose and the rotating
em ergency exten sion handle bega n to strike it, causing
a sudden and rather startling noise .
According to the pilot, 'This unexpected noise
completely d rew my attention from the task at h a nd'
(namely, to take off safely).
On ide ntifying the source of the noise the pilot
became concerned that the sea t belt might fo ul the
handle, thereby causing the landing gear to jam. With
tha t in mind he leant over to try to secure the belt.
While doing this he sensed a change in the Bona nza's
vertical sp eed . A quick look outside the a ircraft
confirmed this: it was sinking , and was a lmost back o n
the runway. The pilot immediately raised the aircraft's
nose to try to re -establish a climb . However, before the
' sink' was arrested a noise was heard. This was
inte rpreted by the pilot as the m ainwheels just touching
the bitumen , as the noise was similar to tha t which
accompa nies a smooth landing.
T he Bo nanza then climbed away a nd , a s both the
undercarria ge UP light and mechanica l UP ind ica tor
appeared normal, the p ilot felt reassured in his
assessment that it was the m ainwhccls which had
inad verte ntl y touched the runway, a nd that everything
was all rig ht. H e therefore decided to continue the flight
as planned.
It was only after a ground insp ection was com pleted
fo llowing the ar rival a t the destina tion tha t it was
realised that it h ad been the inner m a inwh eel doors
and not the wheels which had scrap ed the runway
during the takeoff.
Discussion
One of the perennial topi cs of t he A viation Safety
Dzgest is that of preflig ht preparation and aircra ft
knowledge . There is a ver y good reason for this: the
investiga tio n of accidents a nd incidents continues to
show deficiencies on the p art of m a ny pilots in t hose
areas .
The M35's Pilot's Ope ra ting H a ndbook d oes not
include a n y reference to the undercarriage emergency
extension handle in the preflig ht c hecklist. In the
Emergency Procedures Section it does , however, sta te
that the handle should be kept in the disengaged
position when not in use. From the a vailable evidence,
it seems that the pilot did no t check this before flight.
I t is also apparent tha t he did not observe the sound
practice of securing all unused seat belts during his
preflight inspectio n .
Comment
Many GA pilots fly infrequently. If you fall into this
category, or h ave not flown a p articular type recently,
one of the m ost important safety-related actions you
can take is to rea d thoroug hly the Pilot's Opera ting
H andbook before a flig ht. Sa fe oper ations simply
cannot be expected if you a re no t familiar with your
a ircraft's limitations, n orm al procedures, emergency
procedures and so on.
It always bears repeating tha t preflight preparation is
the b asis of avia tion safety . Before every flight, could
you tell yourself wit h confidence that you are familia r
with and feel comfortable a bo ut all of the o per a tional
information relevan t to your intended activities? If the
a nswer is n ot a positive 'yes', then you need to re examine yo ur approach to pilo ting •
Aviation Safety Diges t 125 I 3
�Fatigue on the midnight express
A light twin was cruising at 10 OOO feet on a 'midnight
express' freight run. The pilot's first takeoff on the
period of duty had been made at 0055 hours local time
and he had departed on this, the final leg, at 0445. At
0511 he gave a position report to Sydney Flight Service
Unit (Fsu) which included an estimate of 0544 for
entering controlled airspace approaching Melbourne.
In the following 33 m inutes the pilot did not, however,
contact Melbourne FSU to receive his airways clearance,
nor did he respond to calls transmitted by the FSU.
At 0536 the probable radar return of the aircraft was
observed at a distance of 80nm from Melbourne and
6nm off track. Shortly afterwards Melbourne Control
commenced communication checks, but again there
was no response.
Finally, at 0555, Melbourne FSU received a call from
the pilot: his aircraft was still at 10 OOO feet and was
(as confirmed by the continuous radar surveillance)
26nm from Melbourne-well inside controlled airspace.
The pilot was transferred to Melbourne Control and
given an airways clearance; the flight was then
concluded uneventfully.
Post-flight discussion with the pilot elicited the
following information:
• The flight had been single-pilot with no passengers.
• On the previous day he had flown between 0830
hours local and llOO and then had been off duty;
however, he only managed to sleep between 1900
and 2230.
• He was self-medicating in an attempt to counter the
early stages of a cold.
• Oxygen was available in the aircraft but had not
been used as the flight did not go above 10 OOO feet.
• The pilot believed that he was not actually asleep,
but rather in a low arousal state because when he
became fully aroused again, he noticed that during
the period Melbourne had been unable to contact
him he had tuned navaids and made a heading
adjustment. He had also retuned his VHF radio to
118.62 MHz instead of 118.6 MHz: he believed that if
he had been on the correct frequency he would have
been aroused by Melbourne FSU calling him as he
approached controlled airspace.
Analysis
In reviewing the incident, an aviation medicine
specialist commented that even though the pilot had
been given a rest period before the flight, his 3 ~ hours
of sleep were inadequate. Further, the anti-cold
capsules he was taking might have caused some
drowsiness, thus exacerbating any existing fatigue. It
was also possible that the onset of the cold could have
raised the pilot's temperature, which in turn could have
increased his metabolism and need for oxygen. Given
that he was flying at 10 OOO feet, the oxygen saturation
of his blood would already have been reduced: under
normal circumstances this would have been acceptable,
out here, in concert with the other physiological
factors, his susceptibility to drowsiness was increased.
Findings
Summing up , the Avrned Doctor suggested that the
following factors were relevant to this incident:
• The pilot was tired because of lack of sleep.
• He was probably subject to reduced oxygen tension ,
exacerbated by increased metabolism due to
infection.
• The low workload in a low information environment
(night flying) was conducive to boredom.
• The pilot was self-medicating with drugs which
could have caused drowsiness.
The sum total of these factors was a state of low
arousal/torpor in the pilot which could have had a far
more serious outcome.
*
*
*
This leads to the question: what can we, as pilots, learn
from this potentially disastrous incident?
Fatigue is an almost inevitable consequence of the
type of operation described in the article, and one
reaction might be:
Well, that's all very interesting, but things like fatigue and
common colds are unavoidable, everyday operational
problems. All I can do is hang in there, keep flying, keep
my job and hope that something like going to sleep on the
job doesn't happen to me. It's all just a matter of luck.
If that is your reaction, here is the good news. It is not
just a matter of luck - there are steps you can take to
minimise the effects of fatigue on your performance as
a pilot.
Fatigue
Fatigue is a condition which generally must be 'selfrecognised', i.e. it is difficult to quantify: it depends
not so much on the amount of work performed but ,
rather, how the individual feels. Further, the effects of
fatigue can vary between individuals and may not be
readily apparent to either those affected or their
supervisors. On the positive side of the ledger, we know
what kinds of conditions are most likely to produce a
fatigued pilot, we know what the effects are on
performance, and we know the remedial actions
required.
There are two types of fatigue - acute and chronic.
Acute fatigue is the more common. Caused by
excessive physical and/ or mental activity, it is a
temporary condition associated with short-term stress.
While its effects can be serious, recovery usually
requires only a good night's sleep. The symptoms of
acute fatigue are listed in Table 1.
Chronic fatigue is a function of prolonged exposure to
stress, normally over a period of weeks or months.
Chronic fatigue may not always be as severe as acute
fatigue, but it cannot be so readily relieved. Its
development may be so gradual that an individual may
be unaware that it is happening; while its cure can be
complex, usually requiring an extended period of
recuperation.
Stresses commonly leading to chronic fatigue include
problems most of us experience at some .time or
another: physical illness, career insecurity, family
difficulties, and so on. Chronic fatigue can be manifest
through the symptoms detailed in Table 1, plus those
in Table 2.
Aviation Safety Digest 12515
�TABLE 1. Acute and chronic fatigue
Symptoms
Sleepiness
Signs
Tired, bored, slow frequent yawning or sighing
Lowered standards
Increased rates of errors, sloppy, careless
Increased reaction time
Slow to respond, missing radio calls, rough on the controls
Physical exhaustion
Slow movement, increased effort to carry out work, complaints of cramps or
stiff muscles
Irritability
Fault-finding, impatience, temper flareups, grouchy
Unable to concentrate
Instrument scan breaking down, indecisive, slow in solving simple problems
HunU up
H aving reached 8000 feet during parachuting
o perations , the. pilot of a Cessna 206 completed the
run -in and then closed the throttle in preparation for
the drop. One parachutis t stood on the right main
wheel while fi ve others assembled at the right hand
rear doorway, from which both doors had been
removed. The pilot was looking forwards,
maintaining a steady flight path. H e was wearing
headphones, with the right earpiece displaced to hear
heading instructions, and a Slimpack parachute.
On the jumpmaster' s command 'Go!', all six
parachutists appeared to leave the Cessna , which
produced the normal aircraft response of an upward
' jerk' and a roll left. The pilo t set the aircraft up for
desce nt while immediately turning left to watch the
free fall manoeuvres. After completing one or two
orbits he saw the parachutists separate and the
canopies open. There were only fiv e.
Thinking that one parachute m ay have
malfunctioned or separated some distance from the
others the pilot started a visual search , levelling the
Cessna' s wings to improve his downward visibility.
At about the same time he heard a cry from the rear
of the aircraft. Turning around he saw a leg, with
the foot uppermost, lying vertically against the rear
doorpost. Then a face came into view a bout a metre
below the floor level, outside the aircraft.
The pilot increased engine power slightly , left the
flaps and trims set as they were, and moved back to
the doorway, still wearing his parachute. The aircraft
remained in a reasonably steady a ttitude.
H e found that the parachutist was suspe nded by a
leg strap of her harness, which had hooked over a
triangular seat belt anchorage at the outer edge of
the floor next to the rear door post; the other leg was
under the a ircraft somewh ere, not visible. The
parachutist was trying to reach the door sill with her
right hand but was unable to do so.
TABLE 2. Chronic fatigue
Symptoms
Forgetfulness
Signs
Forgetfulness, unusual preoccupation
Increased reliance on
caffeine, alcohol
Chain smoking, hangovers, coffee addiction
Insomnia
Change of sleep habits, nightmares
Loss of appetite
Not eating well, loss of weight
Depression
Withdrawal, anxiety, fearfulness, confusion, sense of failure
Tenseness
Unable to relax, restless
Psychosomatic illnesses
Headaches, heartburn, constipation, diarrhea, vag ue ches t pains, shortness of
breath
Curing fatigue
As mentioned above, acute fatigue ca n usually be
remedied with a good night's sleep. Also, looking after
yourself with good nutritio n and a sensible exercise
program will help the body to recover more quickly.
Chronic fatigue can b e a complex matter, often as
much psychological as physical. It m ay incorporate a
vicious cycle - you are tired bu t h ave insomnia , or
undernourished but have no appetite, or need exercise
bu t have no energy, etc. The cycle must be broken , but
this can be a lengthy process.
T he key factor is that of learning to leave the
pro blem s ca using the stress behind, or a t least learning
to cop e with them . A change of environment (location ,
job) or a good holiday can help. Often , it is best to
seek professional advice. Psychologists have developed a
range of stress m anagem ent and relaxation techniques
which are very effective and readily available.
Remember, the consequences of not doing anything
could be disastrous.
Preventing fatigue
As usu a l, prevention is better than cure. The following
factors should be ta ken into account by operations
supe rvisors and their crews alike :
• Work- rest schedules. A regular schedule wi ll assist
grea tly.
• Physical condition. 'Norm' has a point - a sensible
exercise program should be a must.
• Good nutrition. We give our aircraft's components
the best of attention, yet sometimes treat our
persona l airframe and engine like a garbage bin.
Healthy eating is essential. Apply a bit of quality
control.
• Moderation in consumption of alcohol, and
smoking. If addicted to smoking, at least a bstain
d uring the period fro m o ne hour before a flig ht
6 I Aviation Safety Digest 125
through to its completion.
• Moderate consumption of coffee and tea - no more
than one cup every three or four hours. Caffeine
induces d ehydration, whic h in turn will degrade
performance.
• Drink sufficient water. Flying necessitates a greater
fluid intake than that required on the ground.
About one glass of water an hour is recommended.
• Exercise while flying - stretch and flex limbs, relax
the neck and back muscles etc. periodically to
improve blood circulatio n a nd reduce fatigue.
Sleep
Special attention must be given to the subject of sleep,
for researchers have found that , when a ll things are
considered, the most common single cause of fatigue
among pilots is that of inadequate o r insufficie nt sleep ,
regardless of the type of flying operations concerned.
Most of the stress factors which cause chronic fatigue
do so because their effect is to disrupt or prevent
proper sleep. (Refer also to Aviation Safety Digest Nos
11 9, 120, 121 and 122). Here there are two vital
elem ents. Sleep must be of:
• sufficient duration ; and
• good quality.
Try to ensure that you have a quiet , dark environment
for sleeping.
Work-rest patterns can seve rely affect your ability to
sleep if they are constantly changed. For example , it
takes some time for the body to a dapt to work-rest
patte rns associated with night work. The situation often
arises in which , just after your body has adapted to a
night sch edule, you are re -scheduled for d ay operations.
This again requires time for the body to re-adapt.
During both of these periods of ad aptation normal
sleep is d isrupted ; thus, if you are constantly chang ing
Grabbing he r arm , the pilot pulled her upwards
until the leg strap became free of the seat belt
anchorage: her legs then fe ll free, leaving her
suspended outside the aircraft by one arm which the
pilot was holding (with some difficulty, as her jump
sui t was slippery ).
As he assessed that it would be a difficult task to
lift the parachutist back into the aircraft because of
the slipstream , the pilot asked her if she was able to
continue with the drop. She nodded, saying that she
was ' OK ', so he let go. He saw her fall for about a
thousand feet and then her canopy opened nor mally .
The pilot resumed his place at the controls, wi th the
Cessna at an altitude of around 5000 feet, and
returned to the landing strip.
It transpired that when the jump command 'Go'
was given , the parachutist followed her normal
practice of diving headlong through the open door.
H owever, on this occasion the right leg strap of her
harness caught on the tri angular seat belt attach
point on the floor of the aircraft a nd she found
herself s uspended upside down under the aircraft.
She said that she had become completely disoriented
and found it imposs ible to get back into the aircraft:
she had been shouting and banging the underside of
the fuselage , but it was only after the pi lot levelled
the C essna' s wings that she had been able to get one
leg back into the doorway a nd raise her head
s ufficiently to be able to shout directly into the
cabin. She was full of praise for the pi:ot' s actions in
extricating her.
The parachute descent after she had been freed
was uneventful.
*
•
•
In accordance with regula tions , the C206 had single
point restraints in the floor for the parachutists.
Additionally, a loose carpet had been placed on the
floor to guard against the possibility of equipment
getting caught up. Despite these apparently
reasonable precautions , a mishap still occurred. The
triangular seat attach point was s ubsequently
removed.
The incident highlig hted the potential dangers
which protuberances inside parachuting aircraft can
pose •
•
Fatigue on the midnight express rcontinuedJ
from day to night work, a sleep deficit will gradually
accumulate. The result can be chronic fatig ue, with its
concomitant probability of potentially disastrous lapses
in performance.
Conclusion
T he idea, then, is to try to get plenty of regular , good
qua lity sleep . One way of achieving this is by stabilising
work- rest schedules as far as possible, the reby ena bling
you to adapt to a particular pattern. Another
important and readily achievable preventative measure
is that of regulating your life style; a nd her e, matters
such as exercise and nutrition are important.
T he processes d iscu ssed in this art icle may require
some discussion with your co mpa ny or clients, but if
implemented they are li kely to result in better a nd sa fer
operations •
Aviation Safety Digest 125 I 7
�T hus, climb performance depends on four facto rs:
• Airspeed- too little or too much will decrease climb
performance.
• Drag-gear, flaps . cowl flaps, propeller, speed and
slip angle.
• Power- amount available in excess of that needed
for level flight .
• Weight - passengers, baggage and fuel load greatly
affect climb performance.
Safe operation of light twins
BOO
Accidents involving light twin-engine aircraft in Australia continue to indicate that not all pilots
understand as well as they should all of the basic factors involved in operating a twin.
700
Ill
~
600
:!:
...0 500
This photograph by Mr Brenton Hollitt was a highly commended entry in the BASI Photographic Competition. Mr Hollitt used a Pentax SP 1000
with Kodak C135 100 ASA film.
U1 400
";!z
300
~
w
2 00
w
a.
Controllability
Aerodynamic controllability can be considered initially
in terms of yaw and roll.
100
110
120
130
140
150
160
170
180
190
200
AIRSPEED( Knots)
Figure 2. Effect of airspeed on drag - and power required to
maintain that airspeed while in level flight.
Drag from
'dead' engine
Yaw. Loss of power on one engine creates yaw towards
the failed engine . Yaw forces must be balanced with the
rudder (see Figure 3).
Roll. Loss of power on one engine reduces propeller
wash over that wing. Yaw also affects the lift
distribution over that wing: in combination , these
factors cause a roll towards the 'dead' engine (see
Figure 4) . The roll forces may be balanced with use of
opposi te aileron . It is also most important to note that
total aircraft drag, and rudder force, are decreased by
banking the aircraft towards the 'live' engine . This will ,
for a steady heading. resu lt in an unbalanced skid ball,
but this, and the minor disadvantage of slightly
increased aileron forces , greatly outweigh higher rudder
forces and extra airframe drag caused by the greater
sideslip which occurs with the wings level attitude.
Note that airspeed control and the power set on the
live engine are also cri tical as far as controllability is
concerned ; these factors are discussed later in this
article.
Critical engine
Figure 3 . Yaw
t''"
The m ajor demand in flying a twin as opposed to a
si ngle is knowing how to manage the flight if one
engine loses power for any reason. This may sound
obvious, but experience unfortunately indicates that it
is not. Safe flight with one engine-out requires
proficiency in two areas:
• an understanding of the factors affecting aircraft
performance during asymmetric flight ; and
• piloting competence in inflight engine -out
procedures.
These key factors are discussed below in relation to
climb performance and controllability.
Climb performance
Climb pe rformance depends on an excess of power over
that required for level fligh t. Loss of power from one
engine obviously represents a 50 per cent loss of
power, but in virtually all light twins, climb
performance is reduced by at least 80 per cent (see
Figure 1).
The amount of power required for level flight
depends on how much drag must be 'overcome' to
sustain level flig ht. It is obvious that , if drag is
8 I Aviation Safety Digest 125
t
0
Figure 4 . Roll
+:lJ
o. --~~~;;~~~~~=~~
o "'
;1_
0
~
-w
>
Oneenglne·out,
end with mlnlmumdrag
On e engine-out,
- -:-----11--- p ropellerwlndmllllng
One engine - out,
gear and fl1p1 down,
prop wlndmllllng.
•
The critical engine is that engine which , if it fails , will
most adversely affect the performance or handling
qualities of the aircraft. The critical engine on most
U.S.-built light twins-i.e., the majority of those fl ying
in Australia -is the left engine , as its failure req ui res
the most rudder force to overcome yaw . The reason for
this is a s follows. At cruise speeds and power settings .
the thrust line of each engine acts through the
propeller hub; thus , neither engine is particularly
critical. H owever, at low a irspeeds and high angles of
attack , the effective thrust centreline shifts to the right
on each engine because the descending propeller blades
produce more thrust than the ascending blades (this is
known as the P-factor) . Thus, the right engine
produces a greater mechanical yawing moment than
does the left, and so requires a greater rudder force to
counteract that yaw (see Figure 5 ).
INDICATED A IRSPEED
Figure1.
Effect of one engine-out and aircraft configuration
on vertical speed.
increased because the gear and flaps are down and the
propeller is windmilling, more power will be required.
No t so obvious, however, is the fact that drag also
increases as the square of the airspeed , wh ile power
required to main tain that sp eed increases as the cube
of the airspeed (see Figure 2) .
Airspeed control
Figure 5. Engine thrust line shifts to right at k>w airspeeds and at high angles of attack
Airspeed control is the key to safe single-engine
operations. Certain speeds must be known and
understood by twin pilots. This article discusses t hose
speeds in two sections :
• Immediately below, the practical implications of
t hose speeds are defined.
• In the subsequent section , a more detailed discussion
is pro"vided, first , of the conditions under which the
speeds are determined and , second, of significan t
operating considerations related to critical speeds.
Aviation Safety Digest 125 I 9
�Key airspeeds
• Vmca - the airspeed below which con trol of the
aircraft will probably be lost.
• Vsse - the intentional one-engine inoperative speed is
a minimum speed selected by the m a nufacturer for
intentiona lly rendering one engine inopera tive in
flight for training purposes.
• Vyse - the a irspeed that will give the best sing leengine rate-of-climb (or the slowest loss of altitude).
• Vxse- the airspeed that will give the steepest a ngl eof-climb with one engine-out.
These key airspeeds are depicted graphically at Figure 6.
Minimum control airspeed
Vmca is designated by the red radial on the airspeed
indicator and defines minimum control speed,
a irbo rne, a t sea level. I t is determined by the
manufacturer as t he minimum airspeed at which it is
possible to recover control of the aircraft within 20
degrees of heading change, and thereafter maintain
straight flight with not more than 5 degrees of bank if
one engine fails suddenly with:
• takeoff power set on both engines;
• the rearmost allowable centre of gravity;
• flaps in the takeoff position ;
• landing gear retracted; and
• the propeller of the failed engine in the takeoff pitch
position (or feathered if fitted with auto-feather).
Sudden engine failures rarely occur with all of the
factors listed above, so the actual Vmca in a particular
situation may b e a little lower than that indicated o n
the AS I . On the other hand , most light twins will not
m ainta in level flight at an airspeed at or near Vmca;
consequently, it is not advisable to fly at speeds
a pproaching Vmca except during training or test
flig hts.
It should be remembered that to minimise the
difficulties which occur on sudden failure unde r the
criti cal circumstance (e.g. just after ta keoff) , the pilo t
should accelerate quickly to recommended single
engine and then all-engines operating climb speeds. It
is important a lso to remembe r that whilst som e
m a nufacturers provide a speed margin between Vm ca
and recommended lift-off speed, others do not, and
there may be very little or no speed margin provided in
the data , for either reasons of ground control or m erely
the desire of the manufacturer to show minim al takeoff
distance figures.
Vsse and Vmca demonstrations
Vsse may be specified by the a eropla ne manufac turer
in Pilot 's Operating Handbooks, and is the minimum
speed at which a n erigine should be deliberately shut down for training or demonstration purposes. T he use
of Vsse is in tended to reduce the accident potential
from loss of control after a n engine shut -down at or
nea r minimum control speed. Vmca demonstrations are
necessary in training but must n ot be practised with a
prope ller feathered or an engine shut down. In
addition , t he pilot-in-command must ensure that :
• the aircraft is at a safe altitude a bove the terrain ,
and
• Vmca for the particular aircraft type is greater tha n
the sta ll speed for the configuration and weight.
To demonstrate this sequence, power reduction
should be m ade on one e ng-ine at or above Vsse or ,
10 I Aviation Safety Digest 125
Best single-engine rate-of-climb speed
Vyse is designated by the blue radi a l o n the airspeed
indicator . Vyse delivers the greatest gain in altitude in
the shortest possible time, and is based on the following
criteria:
• c ri tical engine inoperative, and its propeller in the
minimum drag position ;
• operating engine set at not more th an m aximum
continuous power;
• landing gear retracted;
• wing flaps in the most favourable (i.e., best lift/ drag
ratio) position ;
• cowl flaps as required for engine cooling; and
• aircraft flown at the recommended bank angle.
Drag caused by a windmilling prope ller, extended
landing gear , or flaps in the landing position , will
severely degrade or destroy single-engine climb
performance. Single-engine climb performance varies
wide ly with the type of aircraft , weight, temperature ,
a ltitude and aircraft configuration . The climb gradie nt
(al titude gain or loss per mile) may be m a rginal o r
even negative under some conditions. Study the Pilot's
Operating Handbook fo r your specific aircraft a nd
know what performance to expect with o ne engine ou t.
Vertical
Speed
·--1-
I
11--1
11-+
Figure 6. Key single engine airspeeds
Vmca
Single enQine power · on
stall speed
l!l
:::>
....
5
<
UI
a:
:::>
~
Recovery
may be difficult
"'
a:
Q.
Figure 7. Relationship between stall speed and Vmca for
aircraft with normally aspirated engines.
where Vsse is not specified, a t a safe m argin a bove
Vmca. Power on the operating (good ) engine should be
set at the position for m aximum continuous operation.
Airspeed is then redu ced slowly (one knot per second)
until control of the aircraft can no longer be
maintained (e.g . heading cannot be maintained
through loss of directiona l con trol , or lateral control
canno t be main tained ; the limits may be dictated by
control forces o r control stops). Note that at higher
altitudes, with norm ally aspirated engines, the first
symptoms of a stall may appear before Vmca is
reached (see Figure 7). Recovery is necessary so that
spin conditions are avoided. This exercise, which in
fac t is the determination of static Vmca at the
particular a ltitude under the given conditions, should
precede dynamic Vmca exercises, where simulated
sudden engine failures (as opposed to the preset
reduced power settings used for static Vmca
demonstrations as described above) are made in the
appropria te configuration at d ecreasing airspeeds.
Recovery from flight below Vmca is made by
reducing power on the operating (good) engine,
decreasing the angle of attack by lowering the nose,
accelerating throug h Vmca, and then restoring
required power to the operating engine a nd
acce lerating to Vyse , the blue radial speed .
Best single-engine angle-of-climb airspeed
Vxse is used only to clear obstructions during a n initia l
climb-out as it gives the greatest altitude gain per unit
of ho rizontal distance. It provides less engine cooli ng
a nd requires more rudder deflection th an Vyse.
General considerations
Having discussed the m ain aspec ts of key sing le-engine
performance speeds, attention must now be drawn to
some importa nt general operational considera tions.
Single-engine service ceiling
The single-engine service ceiling is the maximum
a ltitude at which an aircraft will climb, at a ra te of at
least 50 feet per minute in smooth a ir, with one
propelle r feathered.
The single-engine service ceiling ch art should be used
during flight planning to determine whether the
aircraft, as loaded, can maintain the e n route lowest
safe a ltitude if !FR, or terrain clea rance if VFR ,
following an engine failure .
Basic single-engine procedures
Know and fo llow the single-engine emergency
procedures specified in your Pilot 's Opera ting
H andbook for your specific make and m odel of
a ircraft. The following procedures apply gene rally:
• Maintain aircraft control and airspeed at a ll t imes.
T his is cardinal rule no. 1.
• Usua lly, apply maximum power to the o perating
engine. However , if the eng ine failure occurs during
cruise or in a steep turn, you may elect to use only
e nough power to maintain a safe speed and a ltit ude.
If the failure occurs on final approach, use power
only as necessary to complete the landing.
• Red uce drag to a n absolute minimum .
• Secure the fa iled engine and related sub -systems.
The first three step s should be done promptly and from
memory. The check list should then b e consulted to be
sure tha t the inoperative engine is secured properly and
that the appropriate switches are placed in the correct
position.
CAUTION: Be sure to identify the dead engine
positively before feathering its propeller. Many
pilots - both students and veterans a like - have
feathered the wrong propeller. Do not let it happen to
you. Remem ber, first identi fy the suspect engine ('dead
leg, dead engine'); second, verify your identification by
cross-reference to engine instruments and , on some
piston engine aircraft, by cautious throttle movement ;
then feather . But be certain that the engine is dead
and not just sick.
Engine failure on takeoff
If an engine fails befo re liftoff speed is attained , the
only proper a ction is to discontinue the takeoff. If the
engine fails after liftoff with the landing gear still
down , the takeoff should still be discontinued if touch
down and roll-out on the remaining runway is still
possible.
If you do find yourself in a position of not being able
to climb, it is much better to pull the power on the
good engine and land straig ht ahead than to try to
force a climb and lose control.
Pilot's Operating Handbooks for a number of light
twins contain guidance co ncerning engine fa ilure
during takeoff, specifically in relation to:
• Accelerate- stop distance: this is the distance
required to accelera te to liftoff speed and , assuming
a n engine failure at the instant th a t liftoff speed is
attained , to bring the a ircra ft to a full stop.
• Accelerate- go distance: this is the distance re quired
to accelerate to liftoff sp eed and , assuming an
engine failure at th e inst ant liftoff speed is attained,
to continue the t akeoff on the remaining engine to a
height of 50 feet.
When considering such guidance, pilots should make
allowance, not only for the prevailing conditions, but
a lso for the fact that the m an ufac turer's data may have
been determined under favo urab le test conditions.
Study your accelerate- go c harts carefull y. Most
aircraft are not c apable of climbing out on one engine
under all weight , pressure altitude and temperature
conditions. Know , before you taxi, whether you can
maintain control a nd climb-out if you lose an engine
whi le the gear is still down . It may be necessary to offload some weig ht , or wait for more favourable
temperature or wind conditions.
It is important to rea lise tha t there is no reg ulatory
requirement for continued takeoff capa bility in light
twin aircraft, nor the requz'rement for any positive
climb at all in certain sm a ll light twins. The re is much
truth in the som ewhat cynical sta tement that 'many
light twin-engine a ircr aft are m erely si ngle-engine
aircraft with their power d ivided into two individual
packages'. The cap a bility of en route continua tion of
fl ig ht and safe landing after an eng ine failure is usu ally
there; however, the cap a bility of some lig ht twins for
climbing away from the ground after sudden engine
fai lure, even if t he optimum config uration is q uickly
achieved and faultless pilo t performance exhibited, 1s
often just not availa ble.
When to .fly Vx, Vy, Vxse and Vyse
During norm a l two-engine operations, a lways fly Vy (or
Vx if n ecessary for obstacle clea ra nce) on initia l climb -
Aviation Safety Digest 125 I 11
�out. Then, accelerate to your cruise climb airspeed ,
which may be Vy plus 10-15 knots after you have
obtained a safe altitude. Use of cruise climb airspeed
will give you better engine cooling, increased inflight
visibility and better fuel economy. However, at the first
indication of an engine failure during climb -out, or
while on approach , establish Vyse or Vxse , whichever is
appropriate. (Consult your Handbook or Flight Manual
for specifics.)
Remember, too, that single-engine go-arounds in
light twins are virtually impossible unless they are
commenced several hundred feet above the ground and
with adequate airspeed in hand. Plan any single-engine
approach well ahead, use final flap with extreme
caution and only when committed and keep that
airspeed up , again until committed.
Summary
Know the key airspeeds for your aircraft and when to
use them:
Vmca (Red radial) - never fly at or near this airspeed
except in training or during flight tests.
Vsse-never intentionally shut down an engine below
this airspeed.
Vyse (Blue radial) -always fly this airspeed during a
single-engine emergency during climb-out (except when
necessary to clear an obstacle after takeoff) and on
final approach until committed for landing.
Vxse- fl y Vxse to clear obstacles, then accelerate to Vyse.
Aircraft accident reports
FIRST QUARTER 1985
Know the performance limitations of your aircraft ,
including- its:
• accelerate-stop distances;
• accelerate-go d istances;
• single-engine service ceiling; and
• maximum weight at which a single-engine cl imb is
possible.
Know the basic single-engine emergency procedures:
• Maintain control of the aircraft by flying at the
proper airspeed.
• Apply maximum power, if appropriate.
• Reduce drag (includes feathering).
• Complete engine-out checklist.
And finally, put your knowledge into practice with a
qualified instructor observing and assisting you. Engine
failure can be handled competently and safely by
proficient pilots. Proficiency is related to currency, and'
both are fundamental to safety •
The fol lowing information has been extracted from accident data files maintained by the Bureau of Air Safety Investigation. The
inten t of publish ing these reports is to make available information on Australian aircraft acciden ts from wh ich the reader can
gain an awareness of the circumstances and conditions which led to the occu rrence.
At t he t ime of publication many of the accidents are st ill under investigation and the information contained in those reports
must be considered as preliminary in nature and poss ibly subject to amendment when the investigation is final ised.
Readers should note that the informat ion is provided to promote av iat ion safety - in no case is it intended to imply blame or
liability.
Note 1:
All dates and t imes are local
Note 2:
Injury classi fication abbreviations
e.g.
C = Crew
P = Passengers
0 = Others
N
F = Fatal
S = Serious
M = Minor
C1S, P2M means 1 crew member received serious inj ury and 2 passengers received minor inj uries.
= Ni l
PRELIMINARY REPORTS (The following accidents are st ill under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
06 Jan
Pi per 28- R200 VH-WIN
Non commercial - pleasure
C1 N, P2N
1245
Bourke NSW
Denili quin NSW/Bullaroon Sin. NSW
8521002
As the pilot was attempting to locate the airstrip at his destination, he noticed some of the aircraft's electrical equ ipment had failed.
He decided to proceed to Bourke and land . On arrival over Bourke the pilot selected the gear down but did not obtain any indication of
the gear position. He then manoeuvred the aircraft in an effort to assist gear extension but did not attempt to use the manual override
system. The aircraft was landed with the gear retracted.
Quick conversions
06 Jan
Bell 206B VH -BHC
Act ivities associated with fire control
C1S, P1S, P1M
1103
Hoskinstown NSW
Hoskinstown NSW/Captains Flat NSW
8521001
Just after lift off, the pi lot init iated a climbing left turn and the helicopter struck a powerline about 120 metres from the take-off point.
Control of the helicopter was lost, it impacted the ground and rolled inverted. The occu pants were able to evacuate the wreckage
before it was destroyed by fire.
11 Jan
Cessna 172K VH-RGT
Non commercial - pleasure
C1M, P2N
1133
Mittagong NSW
Mittagong NSW/Coffs Harbour NSW
8521003
T he pi lot reported that t he aircraft became airborne after a ground roll of about 760 metres and initial c limb was commenced at an
indicated airspeed of 65 knots. Soon after li ft off the climb performance of the aircraft decayed and the airspeed reduced to 50 knots.
Several gradual turns were made to avoid trees bu t the aircraft struck trees on rising terrain and impacted the ground.
11 Jan
Hughes 269-C VH -KLO
Non commercial - pleasure
C1 N
0917
Scartwater 28 W
Jumba Old /Scartwater Old
8511001
The pilot reported that t he engine stopped without warning during cruise at 3000 feet. Restart attempts during an autorotation were
unsuccessfu l. The helicopter was landed in a small clearing and the tail boom was severed.
• follow the arrow ar:id multiply
• backtrack the arrow and divide
For AVGAS calculations piston SG 0.72
• follow the arrow and multiply
• backtrack the arrow and divide
These small charts need only a hand held calculator to
use. They enable you to convert fuel figures from any
volume units to any weight units, and vice versa.
All the figures in the diamond-shaped boxes are
precise while all the figures in the c ircles are 'about'
right. The qualification 'about' right is necessary because
those circled figures depend on the specific gravity of
the fluid in question, which in turn depends on its
temperature. An average SG of 0.8 has been used for
jet fuel and 0.72 for AVGAS.
These figures are not intended for use in precise flight
planning; rather, they are for quick refere nce and are
s ufficiently accurate to eliminate gross errors and keep
you out of trouble .•
For jet A calculations turbine SG 0.8
12 Jan
Czech Blan ik L 13 VH-GBT
Instruct ional - solo (supervised)
C1F
1655
Tu mut NSW
Tumut NSW/Tumut NSW
8521004
The student pilot was briefed to conduct a soaring flight of not greater than 1 hour duration. The aircraft departed strip 35 via aerotow
into a light northerly wind. During the flight the wind changed to a gusty sou th-westerly. The pilot did not return for 2 hours and then
rejoined the circui t for strip 35. At approx imately 100 feet on final approach the aircraft abruptly entered a steep dive and impacted the
ground in a steep nose down att itude.
...
•
14 Jan
Cessna 180K VH-SAA
Trai ning
C2N
0900
Bundaberg Old
Bundaberg Old /Bundaberg Old
8511002
Towards the end of the landing roll the aircraft started to veer left. The pilot under check applied right rudder and considerable power
and the aircraft swung sharply right. The left wing and elevator t ips contacted the ground before the instructor cou ld take over and
regain control of the aircraft.
15 Jan
Piper 34 - 200T VH-KGR
Charter - passenger operations
C1 N
0635
Clermont Old
Emerald Old /'Wondabah' Old
8511003
After arriving in t he area the pilot was unable to locate the destination strip. He decided to land on a gravel road near a house to seek
directions. Shortly after a normal touchdown the nosegear collapsed and the aircraft came to rest in a drain beside the road . The pilot
reported that there had been nosewheel sh immy during the previous take-off and just prior to the nose leg collapsing.
17 Jan
Cessna A 185E VH-SWE
Charter - passenger operations
C1 N, P2N
0900
Clermont Old 32N
Emerald Old /Bendemeer Stat ion
8511004
After a normal touchdown a swing to the right developed. The swing was controlled initially with rudder but, as brake became
necessary the pilot lost directional control. After the aircraft had swung through about 120 deg the left wheel was dislodged . Initial
investigation indicates that the fai lure of a bolt in the left brake assembly caused the brake to become ineffect ive.
12 I Aviation Safety Digest 125
Aviation Safety Digest 125 I i
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point /Destination
Injuries
Record number
Date
Time
18 Jan
Bell 206B VH-WNB
Charter - cargo operations
C1M
0748
Karratha WA 20N
Legrendre Island WA/MV 'Western Odyssey'
8551002
After establishing level flight with an external sling load, the pilot felt a bump from the rear of the helicopter. He corrected the
accompanying pitch change and then a second bump was felt. The load was jettisoned and immed iately the helicopter began yaw to
the right. The pilot was unable to regain control before the helicopter struck the ground.
22 Jan
Cessna 172N VH-KGA
Non commercial - pleasure
C1 N
1555
Esperance WA 34SW
Esperance WA/Esperance WA
8551003
As part of his pre-flight inspection, the pilot completed a water check on each of the wing tanks and operated the fuel strainer knob,
al though a sample was not drawn from this point. During the flight the pilot noticed a strong smell of fuel. As he turned back towards
the departure aerodrome the engine lost power. The pilot carried out a forced landing into an area of dense light timber, during which
the aircraft struck several trees.
..
18 Feb
Piper 28-161 VH-UBM
Instructional - dual
C2N
1155
Deniliquin 22NE
Deniliqu in, NSW/Denili quin, NSW
8521013
At the conclus ion of the dual train ing segmen t of the fli ght the instructor decided to demonst rate a forced landing sequence. Descent
was continued to a very low height, and during the go-around the aircraft struck a fence at the approach end of the selected paddock.
Control was maintai ned and a safe land ing was subsequently carried out at the dest ination aerodrome.
20 Feb
Piper PA23-250 VH-JEN
Charter - passenger operat ions
C1 N, P2N
0840
Palm Island , Qld.
Town svi lle, Old/Palm Island, Qld
8511008
The pilot stated that when braking was applied after touchdown, the aircraft did not decelerate normally. A go-around was carried ou t,
and after the aircraft became airborne, the nosewheel struck a fence. As a resu lt the nosewheel became misali gned and the nose gear
col lapsed during the subsequent landi ng at Townsville.
27 Jan
Pitts S1 VH-DDS
Air show/air racing/air trials
C1 M
1410
Lake Eppalock Vic
Moorabbin Vic/Moorabbin Vic
8531002
A low level aerobatics display was being conducted over the lake. Towards the end of the display the pilot intended performing a
hesitation roll at 500 ft agl , followed by a 45 deg climb and stall turn, with the dive recovery to be flown in the opposite direction.
Buffeting was experienced during the stall turn recovery and the pilot was unable to regain full control before the aircraft struck the
water.
21 Feb
Cessna A188-A1 VH-KVK
Aerial agriculture
C1N
1800
Trang ie, NSW 11 E
Bu rratipi, NSW/Burratipi, NSW
8521014
On commenc ing the c lean up run, the wire deflector on the aircraft s truck a single power line. The top section of both the fin and rudder
were severed from the aircraft wh ich was subsequent ly landed at the departu re strip without f urther damage.
31 Jan
Piper 23-250 VH-AVE
Charter - passenger operations
C1N , P2N
0626
Bankstown NSW
Bankstown NSW/Widdin NSW
8521007
The pilot reported that the landing gear selector was in the neutral position and the three gear indicator lights were green as he
commenced the take-off roll. At about 40 knots the gear commenced to retract and the aircraft slid to a halt with the gear indicating up
and locked.
24 Feb
Beech 76 VH-BGY
Non commercial - pleasure
C1N, P3N
1087
Moorabbin, Vic.
Launceston, Tas./Moorabbin, Vic .
8531007
Shortly after a normal touchdown directional control problems were experienced and t he left wing began to lower. The pil ot applied
fu ll power and carri ed out a go around. The pilot advised the tower that the left mainwheel tyre was probably f lat, and subseq uently
positioned the aircraft for another landing. Normal gear down and locked lights were· il luminated, however after touchdown the left
gear leg began to collapse and the aircraft slewed of f the side of the runway.
Britnor 2-A20 VH-IGT
Sport parachuting (not associated with
an airshow)
C1 N, P11 N
1500
Wilton NSW
Wilton NSW/Wilton NSW
8521009
During the take-off roll the aircraft did not achieve flying speed by the point where it was normally expected to become airborne. The
pilot abandoned the take-off and applied maximum braking, but was unable to preven t the aircraft over-ru nning the st rip. The aircraft
broke through the boundary fence and came to rest in a small ditch.
03 Mar
Cessna 172N VH-TSQ
Non commercial - pract ice
C1N, P1N
0830
Falmouth, Tas
Falmouth, Tas/Falmouth Tas
8531009
The pilot intended to conduct pract ice circuits and landi ngs in preparation for competit ions later in the day. On the first landing the
aircraft bounced slightly and then veered in to soft earth at the edge of the newly constructed st rip. The nose gear leg col lap sed and t he
left wing tip struck rocks adjacent to the strip.
06 Feb
Transav PL 12 VH-MLJ
Aerial agriculture
C1 N
1023
Deloraine Tas 8E
Deloraine Tas/Deloraine Tas
8531003
At the conclusion of spraying operations the pilot initiated a climb enroute to his destination. Almost immediately, the eng ine failed
completely and the pilot was committed to a landing in a barley crop. During the land ing roll the nosewheel was broken off and the
aircraft overturned.
10 Feb
Brasov IS-28B2 VH-CQF
Instructional - dual
C1N
141 5
Lightning Ridge
Lightning Ridge/Lightn ing Ridge
8521010
When the aircraft had reached a height of about 300 feet agl the winc h motor lost power. The pilot released the launch cable and
attempted to land straight ahead but the aircraft overshot the end of the landing area and co ll ided wit h trees.
ii I Aviation Safety Diges t 125
16 Feb
Cessna 172-B VH-CRB
Charter - passenger operat ions
C1 F, P2F, P1 S
1520
Rylstone NSW
Ry lstone NSW/Rylstone NSW
8521012
W itnesses reported that after take-o ff in hot and gusty crossw ind condi tions the aircraft did not climb away normally. It passed over
the boundary fence at a low heigh t and then remained at about tree-top heig~t for about one kil ometre. The aircraft was then seen to
turn sharply to the left before disappearing from view. It was subsequent ly discovered to have struck the ground while in a steep nosedown attitude, and been completely destroyed by a post impact fire.
17 Feb
Bede BD4 VH -ABD
Air show/air racing/ai r trials
C1 N, P2N
1440
Tanunda SA 5SSW
Woodside SA/Row land Flat SA
8541003
During t he approach, the aircraft struck the ground heavily about 10 metres before the st ri p threshold. The pil ot appli ed ful l power and
carried out a go-around. As a resu lt of the ground contact the nosewheel was torn off and the nose gear leg subsequently collapsed on
landing at Paraf ield.
26 Jan
Cessna 172N VH-WND
Test
C1S
1302
Albury NSW
Albury NSW/Albury NSW
8521006
Following a report of engine rough running a section of an exhaust valve was found to have broken away. A new cylinder assembly
including an exhaust valve was fitted but on take-off for a test flight the engine suddenly suffered a substantial loss of power. During
the subsequent forced landing the aircraft ran through a fence and came to rest in a ditch. Two cy linder assemblies were found to have
suffered internal damage and pieces of the missing section of the previously replaced exhaust valve were found w it hin the induction
system.
08 Feb
Piper 25-235 VH-TOX
Aerial agriculture
C1S
1600
Wilmot Tas 2SE
Sprent Tas/Meander Tas
8531005
The pilot was conducting the last of his spraying tasks for the day. The paddock had an uphill slope and there were two groups of tall
trees at the uphill end. The first run was conducted up the slope but during the subsequent pu ll up and procedure turn strong
turbulence was encountered. The left wing struck branches in one group of trees, cont rol was lost and the aircraft struck the ground
heavily. The fuel tank ruptured, a fire broke out and the wreckage was completely gutted.
Injuries
Record number
17 Feb
Piper 28-151 VH -RUZ
Non commercial - pleasure
C1N, P2N
1900
Moorabbin Vic
Bal larat Vic/Moorabbin Vic
8531011
The pilot was turning into the parking area, intend ing to taxy between aircraft parked in parall el rows. As the t urn was completed the
left wing tip struc k the spinne r of the aircraft at the start of the left hand row . Th is aircraft was undamaged, however the wing tip of the
taxying aircraft was pushed rearwards with consequent damage to the rear spar fuselage carry-throu9h member.
24 Jan
Socata 880B VH-UQG
Non commercial - business
C1N P2N
0946
Wellington NSW
Wellington NSW/Mudgee NSW
8521005
The pilot had diverted to Wellington because of thick bushfire smoke on his intended track. Take-off was initiated after the smoke had
cleared, however shortly after becoming airborne the aircraft sank towards the ground. The pilot subsequently advised that although
the engine was developing full power he was unable to prevent the sink from continuing until the aircraft struck the ground heavily, 210
metres beyond the boundary fence of the strip.
07 Feb
De Hav DH82-A VH-BFW
Non commercial - pleasure
C1M, P1S
1520
Yarram Vic 8S
Alberton Vic/Alberton Vic
8531004
After a short flight in the local area the pilot made a long low final approach towards the intended landing point. During the approach
the pilot temporarily forgot that powerlines crossed the flight path. The aircraft col lided with the wires, which we re 68 feet agl, and
struck the ground in a vertical nose-down attitude about 800 metres from the landing area.
Kind of flying
Departure point /Destination
11 Feb
Cessna 210-N VH-HOC
Instructional - dual
C2N
1628
Georges River NSW
Haxton Park NSW/Bankstown NSW
8521011
,
The aircraft was flown to Hoxton Park and a number of c ircuits and landings were carried out as part of an endorsement exercise. The
pilot in command then elected to return to Bankstown in order to refuel the aircraft. Du ring the approach the engine lost power and
attempts to restart it were unsuccessful. A ditch ing was carried out in the Georges River and the pil ots swam to the shore.
24 Jan
Beech 58 VH-EZB
Charter - passenger operations
C1N, P2N
1450
Halls Creek WA
Halls Creek WA/Fitzroy Crossing WA
8551004
During the start sequence for the left engine, a loud bang was heard and the fuel agent noticed a fire under the aircraft. He advised the
pilot, who secured the engine and along with the passengers, evacuated the aircraft. The fire was extinguished but the left wing was
damaged .
03 Feb
Aircraft type & registration
Location
...
...
04 Mar
Robinson R22 VH -UXT
Instructional - check
C2N
1327
Camden, NSW
Camden, NSW/Camden , NSW
8521015
As the final sequence of a li cence test fl ight the examiner reques ted the pilot to carry out a normal autorotative landing from circu it
height. The airc raft was flared slightly high, recovered but subsequent ly contacted the ground in a tail low attitude. It t hen bou nced
forward and the tail boom was severed by the main rotor.
05 Mar
Be ll 47-G3B1 VH-ANG
Commerc ial - aerial mustering
C1 M, P1M
1220
Mt Riddock Stn, NT
Mt Riddock Stn, NT/Mt Riddock Sin, NT
8541 004
During mustering operations the pilot landed on two occasions in order to visually check the amount of f uel remaining. Although the
second of these checks revealed an estimated endurance of 20 minutes, the pilot elected to carry out a further short musterin g task
before return i ng to the refuelling area about 4 ki lometres away. Wh ile en route to the refue lling point the engine sudden ly stopped. The
pilot entered auto-rotat ion bu t had to manoeuvre to avoid trees and the aircraft subsequent ly landed heavily.
05 Mar
Cessna 172A VH -DZA
Non commercial - pleasure
C1N
1900
Nullagine, WA
Li mestone Stn. WA/Nullag ine, WA
8551005
The pilot planned to arrive at his destination ·1 0 minutes before last light. However, deviating around rain showers and conducting an
aerial inspection of a prospect ing site, the pilot's arrival was delayed unt il 10 minutes after last light. An approach was made to the
unlit s tri p using the aircraft land ing light for guidance. After f laring at about 15 feet agl the pilot waited for touchdown but the aircraft
stalled and struck the ground nosewheel first, collaps ing the nose gear.
Aviation Safety Digest 125 I iii
�Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
05 Mar
Cessna 172G VH-PLX
Commercial - aerial mustering
C1N, P1N
1500
Windorah 80SSW
Keeroongooloo Stn. OldlWindorah 80SSW
8511010
The pilot was attempting to move cattle away from the intended landing strip when he noticed a shorter strip which was free of stock.
He elected to use the shorter strip but did not notice that it was crossed by a washout. Duri ng the land ing roll the ai rc raft entered the
washout, which was about 40 centimetres deep and 1.5 metres wide. The nose gear fork was broken and damage was sustained by the
propeller, engine cowli ng and right wing.
09 Mar
Glasflugel Mosquito VH-FOR Non commercial - pleasure
C1N
1615
Jondaryan Old
Jondaryan Old/Jondaryan Old
8511011
Deteriorating soaring condi tions resulted in the pilot landing at a strip close to his intended destination. The landing was uneventful
and the pilot arranged for an aero-tow launch. During the take-off rol l the left wing of the gl ider dropped slightly and became caught in
long grass. The glider veered violently to the left, became airborne for a few metres then swung to the rig ht and left again before the
pilot could release the tow. The glider sustained several cracks in the mid-fuselage area.
09 Mar
Wittman-W8 VH-SLA
Non commercial - pleasure
C1 M, P1 M
1130
Mt Beauty Vic
Moorabbin Vic/Milla Milla Vic
8531010
Enroute to his planned destination the pilot flew around the Mt. Beauty area for several minutes. He had not previously landed at the
strip and had not intended to on this occasion, however after watching other aircraft operating, a decision to land was made. A go
around was made from the first approach as the aircraft was high on late final. Touchdown from the subsequent approach was made
well into the strip and the aircraft bounced. A go around was initiated but while turning to avoid trees t he left wing struck the ground
and the aircraft cartwheeled, coming to rest inverted.
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure p oint!Destination
Injuries
Record number
20 Mar
Cessna 404 VH-UOP
Sc heduled passenger service - com mu ter
C1 N, P6 N
1233
Lismore NSW
Grafton NSW/Lismore NSW
8521022
On in itial touchdown the pilot detected an abnormality with the landing gear. An immediate go arou nd was carried out and the pi lot
of anot her aircraft reported that the left main gear was sloping rearwards of its normal alignment. The pilot was committed to a
landing with the gear in this posit ion and the gear leg subseq uently collapsed at about 60 knots. Initial invest igation indicated that
t he fai lure of a slotted pin allowed the trunnion forward pivot pin to work itself free, with consequent misalignment of the gear leg.
23 Mar
Bell 206-B VH-KXV
Const ruct ion work
C1M
1220
Karratha WA
Cape Preston WA/Karratha WA
8551006
After depositing the sling carried load on t he ground, the pilot moved the helicopter to t he right to release the cargo net and shackle
from the hook. He operated the release mechanism and as he checked to ascertain if t he release had been success fu l, t he helicopter
commenced to roll to the right. The pilot at tempted unsuccessfully to correct t he rol l and d uri ng the subsequent landing a main rotor
blade struck the ground.
23 Mar
Pi per 28 - R180 VH-KIE
Training
C2N , P1N
1600
Mundijong WA
Jandakot WA/Jandakot WA
8551007
The student pi lot was undergoing a c onversion onto the aircraft type. As part of t he c onversion, t he ins t ructor c losed the t hrottle and
requested t he student to demo nstrate a forced landing. At about 600 feet agl, t he inst ructor, being sat isfied wit h the exercise,
advised the student to go-around. The thrott le was opened bu t the engine did not respond. The ins tructor took con trol bu t was
unsuccessful in his attempts to restart the engine. The aircraft was landed in a paddock and ran through a fence.
09 Mar
Cessna A188B-A1 VH-PLU
Aerial agriculture
C1N
0845
Tum ut NSW
Tumut NSW/ Tumut NSW
8521016
Spray runs were being carried out under a power line when the aircraft cable deflector st ruck the li ne. The cable rode up the cable
deflector and severed the top of the rudder from the aircraft. The aircraft was landed in a paddock without further damage.
24 Mar
Piper 38-112 VH-FLA
Instruc tional - solo (superv ised)
C1 N
1415
Archerfield Old
Archerfield Old /Archerfield Old
8511 014
On final approac h, the pilot reported that the aircraft encountered a st rong headwind. At about 30 feet above the ground the airc raft
began to sink and the stal l warn ing sou nded. The pilot applied some power and selec ted a higher nose att itude, bu t the airc raft
landed heavily on the mainw heels, b ounded onto the nosewheel and t he propeller struck the runway. T he aircraft ran off t he runway
before the pilot was able to regain contro l.
13 Mar
Hiller UH12-E VH-FFT
Activities associated wit h aerial agriculture
C1N
1500
Charleville 146NE
Charleville 146NE/Boxland Old
8511012
The pilot had landed the helicopter in a clearing in order to refuel from drums carried in the aircraft. During the subsequen t take-off into
the strong wind prevailing , downdraft was experienced as the aircraft approached a heavi ly timbered area. A turn was carried out to
avoid the trees but the combined effects of the downdraft and the downwind turn resulted in the helicopter to uching down heavily. The
impact forced the landing skids rearward s, bending the associated vertical support members.
26 Mar
Zenith CH200 VH-MAD
Dept of Aviat ion survey and inspection
C1 N
0815
Dixons Creek Vic
Moorabbin Vic/Dixons Creek Vic
8531 012
Initial touchdown occurred about one t hird of the way along the 518 metre strip. A slight bounce followed and as soon as the aircraft
had sett led on the ground again the brakes were applied. There was no not iceable retardation and the pilot attempted to go around.
T he nosewheel st ruck a gable marker j ust prior to the boundary fence, and t he left mainwheel contacted the top strands of the fence.
The fuselage was punctured by a fence post and the pilot abandoned the take-off attempt. An inspect ion of the stri p immed iately
after the occu rrence revealed a very heavy dew on the short, thick grass surface.
14 Mar
Cessna 182F VH-WPC
Non commercial - practice
C1N
1345
Bankstown NSW
Bankstown NSW/Bankstown NSW
8521021
The pi lot was carrying out a series o f practice circuits and landings. On thi s particular approac h the aircraft bounced after touchdown.
The pilot applied some power in an attempt to cushion the subsequent touchdown , however the aircraft struck the ground heavily and
bounced again. A go around was conducted and was followed by a normal landing. Post-f light inspection revealed damage to the nose
strut, the eng ine f irewall area and the propeller.
15 Mar
Grumman 164A VH-SLK
Aerial agriculture
C1M
0845
Jondaryan Old 30N
Toowoomba Old/Toowoomba Old
8511 013
The pilot had sprayed the paddock using a series of runs in an east-west direction, parallel to power lines along the property boundary.
He then decided to do a clean-u p run in a north-south direction, but forgot about the prese nce of the power li nes. During the pul l-u p at
the end of the run the aircraf t flew into the wires and subsequently struck the ground heavily 219 metres further on.
15 Mar
Cessna 172M VH-RXN
Non commercial - pleasure
C1M , P1S, P1M
1000
Pt Macquarie 75W
Cooranbong NSW/Armidale NSW
8521018
Prior to departu re the pilot checked the fuel quantity. using a graduated dipstick and noted that each tank apparently held 18.5 gallons.
About 75 minutes af ter take-off and whi le cruising at 4500 feet amsl the engine lost all power. The pilot was comm itted to a forced
landing in a rugged, heavily t imbered area. The landing gear was sheared off on touchdown and decelerat ion forces were severe.
Subsequent investigation revealed that the engine failed from fuel exhaustion. The dipst ick used by the pi lot had been graduated in
litres.
18 Mar
Cessna 404 VH-TMP
Sched uled passenger service - comm uter
C1N, P6N
1756
Canberra ACT
Canberra ACT/Williamtown NSW
8521019
In order to avoid thunderstorms in the immediate vicinity, the pi lot requested take-off from a ru nway direc tion giving a slight
downwind component. fhe initial stage of take-off roll was normal, but the aircraft then failed to accelerate. The take-off was
abandoned at about 65 knots Indicated Air Speed, however braking effectiveness was redu ced because of the wet runway
condi t ions. A ground loop was attempted, the nosegear subsequently became detached and the aircraft slid sideways into the
aerodrome boundary fence.
19 Mar
Piper 30 VH-RBT
Charter - passenger operations
C1N, P3N
1718
Coifs Harbour NSW
Tyagaran NSW/Coffs Harbour NSW
8521020
When the gear was selected down it did not fully ex tend. The pilot found that the gear ci rcuit breaker had tripped and after it had
been reset the gear was raised then lowered and a gear down indication obtained. Du ring the subsequ ent landi ng rol l t he aircraft
yawed to the the righ t and ran off the runway. An in spection of the aircraft revealed that t he right main wheel had turned thro ugh 90
degrees due to the scissor linkage becoming disconnected.
19 M ar
Beech V35 B-M K2 VH -1LO
Non commercial - practice
C1N
1530
Robe SA 25SE
'Bray Homestead' SA/'Bray H/stead' SA
8541005
The aircraft was parked abou t 40 metres from its hangar. After carrying out a normal dai ly inspec tion the pi lot boarded the airc raft
with the intention of conducting some practice circuits and landings. As soon as the engine was s tarted it developed ful l power, the
.aircraft acce lerated rapidly and c o ll ided with a truc k which was parked in the hangar.
iv I Aviation Safety Digest 125
27 Mar
Bell 47-G5 VH-DUS
C1N
1430
Boomarra Old
Boomarra OldlBoomarra Old
8511 015
Wh ile hovering at about 20 feet agl, t he pilot attempted to apply power. The eng ine did not respond and t he helicopter was landed
heavily as the pilot was manoeuverin g it to more su itable terrain.
31 Mar
Champi on 7 - KCAB VH-DAY
Non commercial - pleasure
C1N, P1N
1240
Apollo Bay Vic
/Moorabbin Vic /Apollo Bay Vic
8531014
T he pilot decided to carry out a j ow fly past along the strip to check the effect of the prevai ling strong wind. After having f lown along
about a third of t he strip he landed t he airc raft . Du ri ng the landing roll the wind lifted t he left wing and the aircraft began to move off
the right of the strip. The right wheel struck a low dirt mound and was twisted rearward. The aircraft then ran through a fence before
comi ng to rest.
31 Mar
Cessna 172M VH-TCB
Non commercial - pleasure
C1N, P1 N
1730
Moonera WA
Kalgoorl ie WA/Caiguna WA
8551008
Whe n t he pilot encountered navigational difficult ies he decided to land on a road near a homestead and check his location. During
the latter part of the subseq uen t landing roll the pilot misjudged the clearance of the aircraft from a post and the left wing struck the
post.
FINAL REPORTS (The investigation of the following accidents has been completed)
Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
C1N
Glider towi ng
05 Jan
Piper 22-160 VH-AMX
8551001
Northam WA/Northam WA
1057
Northam WA 2E
None
771
7
Private Res t ric ted
32
The aircraft was on climb towing a glider when the pi lot saw smoke and f lames around the left rudder pedal area. The glider was
released and the pilot landed the aircraft in a paddock. He abandoned the aircraft before it was destroyed by fire .
Because of the severity of damage t he cause of the fire could not be determined. It was established that the fire melted f uel lines
beneath the left side of the cockpit floor. The fuel released then fed the f ire which completely gutted the aircraft .
Aviation Safet y Digest 125 I v
�Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
/n;uries
Record
Number
18 Jan
Piper 31 350 VH-WJK
Charter - passenger operations
C1 N,P9N
0992
Saibai Island Old
Horn Island Old/Saibai Island Old
8511005
Commercial
30
2548
506
Instrument rating class 3
The pilot reported that, during approach to the 765 metre wet grass strip, the wind appeared to change to a tailwind. The mainwheels
struck a concrete sea wall which marks the threshold , both tyres burst and the landing gear legs were damaged. Directional control
problems were experienced during the landing and a go-around was carried out, with the aircraft becoming airborne just before the
far end of the strip. The pilot was not aware that any damage had occurred until the gear would not retract. A diversion to an alternate
aerodrome was conducted and the left main gear leg collapsed on landing.
The strip at the original destination was too short for the normal operation of the heavily laden airc raft. Because of thi s, and the
wet surface, the pilot had approached at a lower than recommended airspeed, aiming to land close to the threshold. He had been
unable to arrest the sink rate which developed in the final stages oi the approach.
22 Jan
Cessna 182N VH-EKH
Non commercial - aerial app lication/survey
C1M
0600
Bullamon Plains
Bullamon Plains ALA/Bullamon Plains ALA
8511006
Private
35
106
9
None
The aircraft was being flown between 500 and 1000 feet agl at 60 knots with 20 degrees of flap. A mob of sheep was spotted and the
pilot turned right to keep them in sight. The stall warning sounded and the pilot noticed a lack of elevator control but did not
associate this with a stall. Descent continued while the pilot was engrossed in the elevator problem until the aircraft struck trees in
its path. A major portion of the right wing was severed and the aircraft came to rest on its side.
26 Jan
Cessna A188B-A1 VH-IEO
Aerial agriculture
C1N
1000
Jimbour Old 10N
Dalby Old/Dalby Old
8511007
Commercial
39
4500
2000
Agricultural class 1
The pilot commenced spraying operations before the ground markers had taken up their positions. As he approached the starting
point for the first run he glanced towards the markers lo check their progress towards their assigned places. The pilot then looked
forward and suddenly realised he had temporarily forgotten the presence of a power line which crossed the paddock. Evasive action
was taken, however the top of the rudder struck the wire and was severed. Control of the aircraft was maintained and a safe landing
was subsequently made.
26 Jan
Cessna 180A VH -EYA
Ferry
C1 N
1050
Mansfield 9ENE
Moorabbin Vic/Mansfield 9ENEO
8531001
Commercial
20
1316
150
Instrument rating c lass 4
Whilst applying brake after landing the pilot's foot slipped off the left rudder pedal and the aircraft veered to the right. The pilot
replaced his foot on the pedal and applied corrective rudder and brake but the aircraft subsequently ground looped to the left and the
right main gear leg collapsed.
The rudder pedal surfaces were found to be worn, the pedal design was such that foot restrain ing capabilities were reduced as the
surface became smoother from normal wear and tear. It was also determined that the brake pads on the right gear were excessively
worn and this probably aggravated the pilot's problem with directional control.
26 Jan
Schneider ES-60
Non commercial - pleasure
C1 M
1505
Boomerang VH-GTL
Whitwarta SA/Whitwarta SA
8541001
Glider
Red Hill SA 5S
25
93
6
Glider
During the cross country flight the glider encountered an area of sink. The pilot was unable to find any updraughts and selected a
paddock in which to land. As the glider was on short final, it suddenly lost height and collided with the boundary fence of the
paddock. The glider then landed heavily in the paddock.
The pilot was inexperienced on type and also lacked recent experience of outlandings. The paddock selected gave a shorter
landing distance than desirable and the pilot aimed for a lower than normal height to cross the boundary fence. When sudden sink
was encountered in the hot, turbulent conditions the pilot was unable to prevent colliding with the fence.
03 Feb
Beech C23 VH-UMM
Non commercial - practice
C1 N
1005
Haxton Park NSW
Haxton Park NSW/Hoxton Park NSW
8521008
Private Restricted
36
58
39
None
The pilot, who was inexperienced in total hours and hours on the aircraft type, landed the aircraft firmly. A bounce occurred but the
pilot persevered with the landing. After the aircraft had bounced a further three times the nose wheel collapsed and the aircraft slid
to rest on its nose.
19 Feb
Cessna 152 VH-SPG
Instructional - solo (supervised)
C1N
1140
Moorabbin Vic
Moorabbin Vic/Moorabbin Vic
8531006
Student
41
66
66
None
Following a period of dual instruction the student was authori sed to practice glide approaches. During the first of these approaches
the '3.ircraft bounced after touchdown. Several more bounces occurred and the nose gear leg collapsed. The aircraft slid to a halt 3
metres off the side of the runway.
The aircraft was high on approach and touched down nosewheel first. The pilot stated that the rapid succession of bounces
surprised her and no bounced landing recovery was attempted.
25 Feb
1600
Commercial
Airparts 24-A4 VH-EOF
St Arnaud Vic 25S
45
Aerial agriculture
Stuart Mill Vic/Stuart Mill Vic
9500
5000
C1 N
8531008
Agricultural class 1
Shortly after take-off for a spreading operation the engine suddenly lost power. The pilot dumped the load and operated the fuel
boost pump, however after a short burst of power the engine failed completely. The pilot was committed to a downwind landing and
towards the end of the landing roll the aircraft ran into a gully and collided with tree stumps.
The engine had failed from fuel exhaustion. The pilot was not aware of the amount of fuel added to the tanks at the previous
refuelling and he had subsequently relied on the fuel gauge readings to assess the remain ing endurance.
vi I Aviation Safety Digest 125
Date
Time
Pilot Licence
Aircraft type & registration
Location
Age
Kind of flying
Departure point/Destination
Hours Total
Hours on Type
Rating
Injuries
Record
Number
02 Mar
Cessna 182H VH-PLF
Non commercial - practice
C1N,P1N
1100
Dalby Old
Dalby Old/Dalby Old
85)1009
Private restricted
48
83
29
None
After returning from the local training area, the pilot joined the circuit for a landing. He stated that he flared high, added some power
whilst allowing the aircraft to descend, then reduced power again. The aircraft contacted the runway heavily in a slightly nose down
altitude. The firewall, lower fuselage skin and control tunnel were all deformed, causing control difficulties during the subsequent
taxying.
Followi ng the high flare, the pilot failed to adequately arrest the sink-rate. Skid marks on the runway in the vicin ity of the
touchdown, and a substantial single bald patch on the right tyre indicated that the ri ght brake was probably appl ied at touchdown.
09 Mar
Mooney M20J VH-MVO
Non commercial - pleasure
C1 N,P1 N
1625
Bankstown NSW 13W
Cowra NSWIBankstown NSW
8521017
Private
59
820
350
None
The aircraft was cruising at 1500 feet agl when a large bird was struck. Substantial damage was caused to the right wing of the
aircraft, however the pilot subsequently carried out an uneventful landing.
30 Mar
Cessna 152 VH-TNX
Instructional - solo (supervised)
C1N
1125
Melton Vic
Melton Vic/Melton Vic
8531013
Student
None
During the pilot's second solo flight the aircraft bounced twice on landing. The pilot persisted with the landing attempt and applied
forward control column pressure after each bounce. Following the second bounce the nose wheel struck the ground heavily and was
torn off and the aircraft overturned.
FINAL UPDATES (The investigation of the following accidents has been completed. The information is
additional to or replaces that previously printed in fhe preliminary report.)
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
01 Apr 83
Piper 32-R300 VH-EMD
Private
8321034
1405
Lismore NSW 4N
20
124
8
None
The pilot decided to divert to a nearby aerodrome because the fuel gauges indicated a low fuel quantity remaining. Shortly after
commencing the diversion the engine failed. During the ensu ing forced landing the aircraft struck a fence post, overturned, and slid
inverted for 120 metres.
The engine had failed from fuel exhaustion. During the fli ght, wh ich involved 3 land ings, one refuelling and about 6 hours flight
time, the pilot had not conduc ted a check of the aircraft fuel consumpt ion. Although the fuel gauges indicated a higher than normal
rate of consumption, the pilot did not land al su itable enroute aerodromes and the diversion was not made unt il a critical situat ion
had developed. Subsequent examination of the engine and fuel system did not establish the cause of the excessive fuel
consumption.
25 Dec 83
Piper 32-R300 VH-UAM
Private
8311083
1744
Brampton Island
24
197
120
None
The pilot misjudged the height of the aircraft above the ground when he initiated the landing flare. Touchdown occurred at a high
rate of descent and the left gear collapsed.
The pilot was inexperienced. During the day he had flown for almost 8 hours in Northern Australian summer conditions. Metal
fatigue in the left gear oleo casting had reduced its capacity to withstand side load stress.
18 Jan 84
Robinson R22 VH-CIA
Commercial - helicopter
8451002
1500
Albany Whaling St
23
382
382
None
After take-off, the pilot flew the helicopter low along a beach, over a moored ship and turned toward rising terrain. He then climbed
the helicopter to follow the slope of the rising terrain. About half way up the slope the pilot carried out a turn through 180 degrees.
He reported that the helicopter experienced a loss of engine and rotor rpm. He attempted to recover the situation but the helicopter
touched down and rolled over.
Examination of the engine revealed that one of the magnetos was contaminated with oil. The magneto was tested on another
engine and no power loss was evident. Also, fl ight testing in a similar helicopter confirmed that with one magneto inoperat ive the
power loss was only 3 to 4 percent of the engine rpm. It is therefore probable that during the turn the pilot overpitched the rotors
when insufficient height was avail able for recovery.
03 Feb 84
Amer Air 5 VH-ESC
Private
8421043
1040
Jaspers Brush NSW
55
250
64
None
Just prior to lift-off from t he private airstrip the pil ot stated that the eng ine misfired. He elected to abandon the take-off and veered
the aircraft to the left to avoid a stand of trees j ust beyond the upwind end of the strip. The aircraft could not be stopped before
coll iding with the side boundary fence.
Investigation revealed that the probable cause of the engine misfiring was lead fou ling of one or more of the spark plugs.
Aviation Safety Digest 125 I vii
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
03 Feb 84
Piper 31 VH-KFD
Senior comerclal
8431002
1137
Moorabbin Vic 6SSE
54
14600
4500
Instrument rating 1st class or class 1
The right engine had been replaced as part of a routine maintenance program. During two subsequent flights the engine lost all
power. Extensive ground checks failed to reproduce the symptoms and an air test was then carried out. During the test the right
engine failed and while various techniques were being employed by the pilot to restore power, the left engine also failed. The pilot
was committed to a gear up landing in a paddock and damage was sustained during the ground slide when a mound of dirt was
struck.
Faulty seals in the right engine fuel shut off valve allowed air to be drawn into the fuel lines causing the power losses experienced.
The left engine failed from fuel exhaustion and when the pilot selected crossfeed from the rig ht tank, air was drawn through the
defective valve, preventing further running of the left engine.
05 Feb 84
Hiller UH12-E VH-XRG
Commercial - helicopter
8411003
0930
Beaudesert SSE
44
4000
1500
Agricultu ral class 1
At the end of a 180 deg turn the pilot attempted to level out but there was no cyclic response. The helicopter continued in the turn
and the application of back cyclic could not prevent the nose dropping. The helicopter struck the bank of a creek shearing off the tail
boom, main rotor and gearbox and came to rest in the water. The pilot escaped unhurt and unaided from the partially submerged
cockpit.
Investigation revealed that a bolt which secured a foot of the cyclic control wobble plate pylon to the transmission gearbox had
become detached. Subsequent movement of the pylon deprived the pilot of effective cyclic control. The reason for the loss of the
bolt could not be established.
12 May 84
Cessna 402 VH-CJA
Commercial
8411022
1247
Archerfield Old
50
11500
1000
Instrumen t rating 1st class or class 1
After landing, a 180 degree turn to the right to backtrack along the runway was planned. As the aircraft was being slowed to taxi
speed a gentle left turn to position the aircraft near the left side of the runway was commenced, but the right main gear collapsed. A
gear down indication remained on after the aircraft came to a halt.
The right main gear retraction push-pull tube bellcrank had developed a fatigue crack in the area of the bushing ~ole. The bellcrank
failed in overload at this crack causing insufficient downlock tension to be maintained on the extended main landing gear. The
aircraft had flown 9336 hours at the time of the failure and the left bellcrank had previously been strengthened.
15 May 84
Cessna 340A VH-BYB
Private
8421022
2344
Goulburn NSW
25
700
143
Instrument rat ing 1st class or class 1
Prior to departure the pilot had received a weather forecast which indicated that fog could be expected at the destination. Adequate
fuel was carried in the aircraft tanks to allow for a considerable period of holding and/or a diversion to another aerodrome if required.
After an apparently normal flight of 35 minutes the aircraft arrived in the Gou Iburn area and the pilot reported his intention to carry
out a standard instrument approach. The manoeuvres associated with this procedure do not involve fl ight over the city of Gou Iburn,
however witnesses observed the aircraft as it circled over the city several times at a relatively low height. It was then seen to roll and
descend steeply before striking two houses. A fierce fire broke out which engulfed the aircraft and both residences. The three
persons on board the aircraft and a person in one of the houses received fatal injuries.
A detailed inspection of the wreckage revealed that the camshaft of the left engine had failed in flight and the pilot had apparently
feathered the propeller. The engine was not operating at the time of impact. No other defect or malfunction was discovered which
might have contributed to the development of the accident. It was determined that the particular camshaft had failed from fatigue
cracking, resulting from defective manufacture.
It was considered likely that when the aircraft arrived over Goulburn, shallow fog obscured all or part of the aerodrome. The lights of
the city would have been clearly visible and the pilot probably decided to use the city, rather than the nearby radio navigation aid, as a
convenient holding point while waiting for conditions at the aerodrome to improve. During a series of left hand orbits, and after
advising his intention to conduct an instrument approach, the pilot experienced a complete failure of the left engine.
In order to realise the avai lable single-engine performance of the aircraft the pilot had to perform a series of checks and actions
which would result in the applicable propeller being feathered; any unnecessary aerodynamic drag being reduced; and an
appropriate airspeed being established. It was determined that although the propeller had probably been feathered, the landing gear,
which had evidently been lowered previously, had not been raised to reduce drag. In addition, an analysis of radar returns from the
aircraft, recorded at Canberra, indicated that the airspeed at which the aircraft was flying shortly before radar contact was lost, was
less than the optimum figure. The final manoeuvre described by wi tnesses was consistent with that which follows a loss of control
in twin engine aircraft when power is being supplied by only one engine and the speed is below the minimum required for full contro l.
10 Jun 84
Fuji 200-180 VH-FJI
Private
8441018
1439
Strathalbyn SA
53
620
105
None
An inter-club fly-in had been organ ised at the private airstrip. Due to a long-time interest in aerobatics, the club secretary who had
organised the meeting and was anxious for it to be a success, arranged to accompany the pilot on an aerobatic demonstration flight.
A series of aerobatic manoeuvres, judged by the witnesses to be of a relatively poor standard, were completed between 1500-3000
feet. The aircraft was then observed to overfly the aerodrome at about 300 feet agl and enter what appeared to be a roll. When the
aircraft reached the inverted attitude, its nose was well below the horizon and the roll was not con tinued. The nose then lowered
further and the aircraft impacted the ground at high speed.
Subsequent investigation indicated that the aircraft and its control sys tems had been serviceable prior to impact with the ground.
The pilot was neither approved nor sufficiently experienced to perform aerobatics at a low level and it is probable that on this
occasion his actions were influenced by the presence of the group assembled on the ground.
04 Jui 84
Robinson R22 VH-UXM
Commercial - helicopter
8431019
1220
Mildura Vic 11 ESE
36
6250
150
Unknown or not reported
The aircraft departed Camden on the previous afternoon for a ferry flight to the Kununurra area, with an overnight stop near Eildon,
Victoria. About 35 kilometres from Mildura the pilot reported that he was landing due to a vibration. After inspecting the aircraft he
continued with the flight but later made a brief Mayday call. Witnesses reported that the engine was running intermittently before
the helicopter landed heavily, tail-down , in a vineyard. A contaminant , sufficient in quantity to restrict the flow of fuel, was found in
the fuel system filter.
The source of the contaminant could not be identified, however an identical polyester material was found in the fuel filter of
another new helicopter of the same type. It is probable that the material was present prior to the import of the helicopters. The fuel
filters were not inspected prior to the first flight. The helicopter was being operated on super motor spirit at the time but it is
considered unlikely, in this instance, to have been a major factor in the engine failure. Due to the pilot's incorrect diagnosis that the
power surges were associated with a main rotor problem, he progressively opened the throttle in an attempt to maintain rotor rpm.
This action combined with the momentary power surges, exacerbated control difficulties being experienced and resulted in a
belated autorotative landing.
viii I Aviation Safety Digest 125
j
Date
Time
Aircraft type & registration
Location
Age
12 Aug 84
1528
Robinson R22 VH-UXL
Castle Hill NSW
24
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
helicopter
8421039
Flight instructor grade 1 or 2 with
instrument rating
At the conclusion of the student's first training exercise the instructor positioned the helicopter in a hover at about 3 feet ag l and
allowed the student to use the controls. The aircraft was headed into the 25 knot gusty wind when sudden sin k was experienced. The
student instinctively applied fu ll aft cyc lic control and the heel of the right skid dug into the ground as the helicopter moved
backwards. The aircraft rolled onto its right side, destroying the main rotor blades and distorting the cabin area.
The instructor had allowed the student to attempt an operation beyond the level of his current abili ty and had been unable to
recover control when the sink was experienced.
1718
Commercial 280
23 Aug 84
Cessna A188B·A 1 VH-EVV
Commercial
8421049
1400
Spicers Creek NSW
40
7440
600
Agricultural class 1
During a spray run which involved a flight beneath a power line, the pilot lost sigh t of the supporting poles and assumed he had
passed the cable. A pull up was initiated but the fin and rudder struck the cable, wh ich tore about 15 cm from both su rfaces. The
aircraft remained controllable and a safe landing was subsequently carried out.
06 Sep 84
Cessna A188B-A1 VH-UJR
Commercial
8421046
1515
lllabo NSW 5E
30
3500
700
Agricu ltural class 1
The particular spraying run crossed a group of trees at the top of a rise. As the pilot pulled up to overfly the trees the right wing of the
aircraft struck some branches. The pilot noticed fluid escaping from the tears in the wing and elected to carry out an immediate
landing on the downslope beyond the trees. Shortly after touchdown the aircraft yawed, the left wheel dug in and the aircraft rolled
over twice before coming to rest inverted.
07 Sep 84
Robinson R22 VH-UXK
Private - helicopter
8451023
1800
Mt Farquhar 12NNW
28
2500
2450
None
The pilot was flying the helicopter along a ridge line checking a gully for cattle, when the engine suffered a substantial loss of power.
The pilot initiated an autorotational descent as the engine failed completely. The helicopter landed heavi ly in the base of the gully .
The pilot was aware that there was little fuel remaining in the tank. However he elected to continue and ensure the security of the
mob before last light, so that add itional herding wou ld not be necessary the next day. The helicopter was being operated at a low
height and ai rspeed, over unsuitable terrain at the time the fuel was exhausted.
12 Sep 84
Cessna 172-N VH-POS
Private
8441021
1536
Gove NT
30
135
100
None
The pilot commenced an approach to land after a preceding Fokker F28 had cleared the runway. During the landing flare the pilot
reported that severe buffeting was encountered and the aircraft subsequently landed heavily, with resultant damage to both wings,
the forward fuselage, landing gear and the propeller.
Because of the prevailing conditions it is considered that the disturbance reported by the pilot was unlikely to have been caused
by wake turbulence, however the probable cause of this disturbance could not be determined. When the aircraft suffered the
disturbance, the pi lot applied fu ll power to carry out a go around but the aircraft struck the ground.
12 Sep 84
Bell 47-J2A VH-THH
Commerc ial - helicopter
8441022
1650
Mataranka HS NT
24
335
235
None
A ten minute flight in the local area had been completed without incident. After departure for a second flight the helicopter was
climbed to 150 feet agl to al low the passengers to view the campsite and a herd of animals. The pi lot. and passengers then heard a
loud bang which was followed by a severe airframe vibration. The noise and vibration continued and the pilot elected to carry out an
autorotational descent and land in a small clearing. The clearing was overshot and the helicopter struck several trees.
Investigation indicates that the engine cooling fan drive belt, which rotates at high rpm, failed. The flailing belt then tore a section
of the canvas cooling fan shroud. Vibration was produced when the broken belt and section of sh roud were ingested into the cooling
fan.
16 Sep 84
Cessna U206F VH-WTJ
Commercial
8451025
0725
Halls Creek 115NE
21
650
300
Instrument rat ing class 4
When the pilot applied climb power a loud bang was heard followed by a severe vibration and a loss of power. The pilot selected the
most suitable area of the rough terrain to attempt a landing. During the landing the aircraft struck several trees, the nosewheel was
torn off and the aircraft nosed over. Inspection of the aircraft revealed that one of the propel ler blades had separated in flight.
The propeller blade separated due to overload fai lure, initiated by a fatigue crack commencing at the blade retention thread root, in
the propel ler hub. An airworthiness directive had been issued requiring that the propeller hub be dye penetrant tested for cracks
every 100 hourly inspection. This was not done. The certifying maintenance engineer believed that the A/D was not applicable to this
model hub. The ai rcraft had flown 30 hours since its last 100 hourly inspection.
18 Sep 84
Piper 25-235 VH -KLZ
Commerc ial
8411039
1010
Goond iwindi 50NE
31
680
190
Agricultu ral c lass 2
After conducting a routine strip inspection the pilot was concerned about the height of the wheat on each side and commenced
another inspection from about 10 feet agl. During the inspection the aircraft descended almost to ground level, with its right wing
low, as a result of the strong, gusting wind. The right spray boom contacted the wheat and the aircraft yawed right. As ground
contact was inevitable the pilot closed the throttle and attempted to correct the yaw but the main wheels and left wing contacted t he
ground, causing the aircraft to slew through 180 degrees before coming to rest.
28 Sep 84
Cessna 182-A VH-CJC
Private
8411042
0922
Nangwee Qld
33
484
80
None
After releasing a group of parachutists from 10 OOO feet the pilot commenced descent. Carburettor heat was appli ed unt il the aircraft
was positioned on a long left downwind for the selected strip. Shortly after eng ine power was further reduced and carburettor heat
was selected to off, the pilot realised that the engine had failed. He turned onto a right base leg and manoeuvred the aircraft in order
to land downwind on the strip. The aircraft stalled just prior to touchdown and came to rest inverted.
Subsequent examination of the engine did not reveal any reason for t he reported loss of power. While manoeuvring the aircraft for
a landing the pilot evidently did not pay sufficient attention to the indicated airspeed.
Aviation Safety Digest 125 I ix
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
12 Oct 84
Beech E33 VH-ENU
Private
8411044
1135
Emerald Old
38
385
24
Instrument rating c lass 4
After take-off the pilot noticed that the airspeed indicator was fluctuating between 55 and 60 knots irrespective of the aircraft's
actual speed . He elected to land again but, with his attention directed towards the faulty airspeed ind icator, he forgot to lower the
landing gear prior to touchdown .
Although no fault was subsequently found with the airspeed indicating system, it was probable that a partial blockage of the pilot
tube had occurred. The pilot was relatively inexperienced on the aircraft type and had not previous ly flown this part icular aircraft.
20 Oct 84
Piper 28-181 VH-SVO
Private
8421055
1652
Glen Innes 6NE
48
332
220
None
The aircraft departed with a planned fuel endurance of 170 minutes, and an expected flight time of 116 minutes. About 110 minutes
aHer take-off the engine lost power and the pilot was forced to land on unsuitable terrain. The aircraft sustained damage to the
wings, landing gear and rear fuselage as it ran through two fences and came to rest after striking several trees. Initial inspection
revealed that the spring loaded fuel drain cock for the right tank was in t he open position.
The aircraft was parked on wet grass when the pilot conducted the fuel drain check and he evidently did not visua lly check to
ensure that the right wing drain _cock had resealed. When the engine lost power the pilot switched the electric fuel pump on before
changing tanks. This sequence 1s the reverse of that recommended by the manufacturer and increases the time taken to effec tively
restore power. Adequate fuel had remained in the other tank to allow completion of the flight, had engine power been regained.
23 Oct 84
Bell 47-G5A VH-BHO
Commercial- helicopter
8411046
0900
Miranda Downs Old
32
5640
5310
None
The helicopter was hovering at abou t 100 feet agl when the engine stopped. A heavy landing followed. The pilot reported that he
knew the aircraft normally had an endurance of 220 minutes. On this flight he had been operating for 210 minu'tes, the task was
almost .completed and the refuelling point was a short distance away. He continued for a short t ime with the fuel gauges indicating
empty in order to complete the task.
The engine failed over an area of trees and the subsequent manoeuvring and flight to the closest open area resulted in insufficient
rotor rpm being available to complete an autorotative landing.
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
15 Nov 84
Rockwell S2R VH-WBW
Commercial
8421064
0805
M oree NSW 63NE
36
8000
600
Agricultural class 1
During spraying operations the eng ine began to run very rough ly and lost a considerable amount of power. The pi lot considered that
insufficient power remained to perm it him to d ivert to a sui table landing area and he attempted to land straig ht ahead . Towards the
end of the landing roll the aircraft struck a contour bank and the right landing gear collapsed.
The cause of the power loss cou ld not be positively identified , but was probably related to excessive spark pl ug fouling .
18 Nov 84
Cessna 150M VH-WWU
Commercial
8451032
11 30
Nyang Sin WA 19E
32
479
350
Instrument rating class 4
Whilst sheep spotting the passenger became visibly agitated and the pilot elected to land_During the landing roll the aircraft entered
scrub but was not damaged. After the passenger disembarked the pilot attempted a flapless take-off using a clearing approximately
140 metres in length. The aircraft failed to become airborne and hit several trees before coming to a halt in soft sand.
Prior t-o the attempted take-off the pilot did not measure the available length or refer to the fli ght manual 'p' charts. He
subsequent ly ind icated that his judgement was affected by perceived commerc ial pressure to continue the sheep spott ing operat ion
without undue delay.
18 Nov 84
Piper PA25-236 VH-KKO
Private
8411052
1500
Spring Creek Old
31
315
255
None
The pilot advised that he was taxying towards the take-off threshold of the ALA, using the grassed area alongside the gravel s tri p. He
noticed an anthill about 30 centimetres high in front of the aircraft, but while turn ing to avoid the obstruction the left mainwheel
struc k the anth ill. The gear leg broke at its attachment point to the wing, resu lting in substant ial damage to the wing and the left flap.
20 Nov 84
De Hav 82A VH-PFL
Commercial
8421065
1430
Ban kstown NSW
45
6000
1000
Instrument rating 1st class or c lass 1
The aircraft is fitted with a tail skid and has no brakes. The pilot was taxying on the grass bes ide the taxyway in order to increase the
rolling resist ance of the wheels. His attent ion was directed to the righ t, when the left lower wing s truck a sign wh ich was 6 metres
from the edge of the taxyway.
28 Oct 84
Piper 32-300 VH-ISB
Private
8441024
1806
Darwin· NT
27
120
13
None
The approach was made with full flap extended at an indicated airspeed of between 75 and 80 knots. As the pilot closed the throttle
in preparation for landing, the handle of the throttle lever came off in her hand. The aircraft struck the runway heavil y and bounced
several times, collapsing the nose gear leg.
The pilot had been distracted when the throttle lever handle separated during the landing flare. The handle had been attached by
an unsuitable retaining bolt.
30 Nov 84
H iller UH12E VH-FBH
Commercial-hel icopter
841 1054
1330
Wyena Stn Old
28
2300
1970
Unknown or not reported
The pilot reported that, short ly after commenc ing to cruise at about 750 feet ag l, the helicopter encountered a willy will y and was
thrown almost upside down . During the recovery actions, right pedal was applied rapidly and the operating cable broke. An autorotational landing was initiated but, j ust prior to touchdown , another willy willy struck the hel icopter and it landed wh ile spinning
under the influence of th is disturbance.
28 Oct 84
Piper PA36-300 VH-FEO
Comme rcial
8421057
1130
Deniliquin NSW 25E
39
12000
2000
Ag ricultural class 1
The aircraft was being flown at about 180 feet agl en route to a rice paddy. The pilot reported that as he overf lew an irrigated paddock
strong sink was encountered. Full power was applied and dumping of the hopper load was commenced, but the airc raft touched
down briefly. With full power still applied the aircraft became airborne again, however another touchdown occurred some 250 metres
further on and the pilot closed the throttle. The left wing struck a fence post before the ai rc raft came to rest.
01 Dec 84
Sli ts SA6B VH-ULB
Private
8441029
1845
Aldinga SA
43
900
50
None
After installing his passenger in the ai rcraft, the pilot hand swung the propeller, the normal means of start ing the eng ine. When the
engine fired it ran up to high power and the ai rcraft jumped the chocks . The pil ot attempted to stop the aircraft but it con tinued
forward and coll ided with the side of a hangar. The nose gear collapsed and the wooden propeller shattered as the aircraft came to
rest on its nose.
Du ring the pre-start checks the pilot believes he set the thrott le almost fully open by mistake. The aircraft handbrake was
unserviceable.
03 Nov 84
Cessna 182-N VH-LMG
Private
8421059
1320
Capertee NSW
56
200
80
None
The aircraft was turned onto the base leg bf the circuit earlier than normal becau se of cloud in the area. The pilot selected an
approach speed 5 knots higher than usual as the aircraft was being operated at a greater than normal weight and because of the
turbulence. The aircraft touched down on all three wheels sim ultaneously and bounced. The second touchdown, 100 metres further
along the strip, was on the nosewheel, which collapsed.
The aircraft was not correctly flared before the touchdown, nor was the correct act ion taken after the bou nced landing. After the
second touchdown the nosewheel dug into a soft patch on the strip.
05 Nov 84
Cessna T303 VH-OBH
Senior commercial
8451031
1345 .
Perron Place WA
37
3700
23
Instrument rating class 4
The pilot, who was relatively inexperienced on the aircraft type, elected to conduct a short field approach into a gusting 25 to 30 knot
wind. When he flared the-aircraft he was unable to reduce the rate of descent and the aircraft landed heavily_ Sufficient st rip length
was available to conduct a normal approach using a threshold speed suitable for landing in t he prevailing wind conditions.
10 Nov 84
De Hav C2 VH -IDH
Commercial
8421062
0930
Barham NSW 21N
44
14100
10000
Agricul tural class 1
At a height of approximately 50 feet after take-off the engine suddenly lost all power. The pilot was able to glide the aircraft over
several drainage banks, two fences and an irrigation canal but a high rate of descent developed and the aircraft landed heavily and
overturned. Fire broke out and the cen tral section of the fuselage was burnt out.
The investigation was hampered by the extent of fire damage and the cause of the loss of eng ine power was not positively
established.
14 Nov 84
Transav PL 12 VH-IVH
Airline transport
8441026
1445
Andamooka SA 16E
32
8000
20
Instrument rating 1st c lass or class 1
The aircraft was being flown in company with a helicopter. While en route the pilots had been requested to check the surface of Lake
Torrens for suitability for future operations_The helicopter was landed on a section of the lake whi ch was assessed as suitable for
the fixed wing aircraft. The pilot of that aircraft also assessed the area as suitable and a landing was made at a touchdown speed of
10 knots. Shortly after the nose wheel contacted the surface it began to sink in the soft ground and the aircraft overturned.
x I Aviation Safety Digest 125
01 Dec 84
Aerocdr 500A VH-AGA
Private
8421069
1110
GoulburnNSW
38
1328
139
lnstrument rat ingclass4
The aircraft was being used to transport equ ipment for members of an Aero Club, who were to carry out training at Goulbu rn. As the
pilot was undergoing formation flying training, it was decided that he wou ld lead a formation of two aircraft for the fligh t. A briefi ng
on the procedures to be followed was carried out. During the flig ht the pilot of the second aircraft began to suspect the accu racy of
his aircraft's ai rspeed indicator and requested that it be checked against that of the lead aircraft as the aircraft joined the c ircu it . The
pilot of the lead aircraft extended the landing gear and flew the initial leg of the c ircui t at an indicated airspeed of 96 knots. At the
end of this leg the pilot t urned the aircraft steeply to the left, the nose dropped sli ghtly and the aircraft flicked into a steep righ t turn.
The aircraft then assumed a steep nose down attitude, however, the pilot was able to level the wings and raise the nose to the level
attitude before impact. The impact occurred at a very high rate of sink.
The pilot had not previously pract ised steep turns at relatively slow airspeed and was not aware of the stall ing speed in the given
config uration and att itude. The pil ot was subsequen t ly unable to recall the reason for attempting a steeper than normal turn. When
the aircraft stalled the pilot was unable to effect a full recovery in the height avail ab le before impact with the ground .
14 Dec 84
Cessna A188B-A1 VH-FZD
Commercial
8411056
1620
Kingaroy Old 4SSE
22
228
10
None
As part of the final phase of the rating test, the pilot was required to spray a paddock. An inspection of the area to be treated was
carried out. During the procedure turn at the end of the second spray run, the nose dropped and the aircraft struck the ground in a
near vertical att itude.
The pilot had incorrectly assessed the w ind direction and had carried out the procedure turns at the end of the spray run s in the
wrong di rection. In an ef fort to align the aircraft for the next run, the pilot tightened the turn and the aircraft stalled .
14 Dec 84
Airparts 24-950 VH-MXD
Commercial
8431037
1020
Scottsdale 20NE
45
19900
2000
Ag ri cultural class 1
While en route to the treatment area the pilot noted a loss of engine pow_er. After the load of superphosphate was dumped, he
reali sed he would be unable to return to the departu re strip and selected a track as the most suitable land ing area. Du ring the landing
roll the aircraft ran over a hump wh ich caused it to slew off the track into the surrounding bush.
Engine examination revealed that the fuel injector system was out of adjustment, producing a lean mixture at high power setti ngs.
The resulting high combustion temperat ures produced abnormal eng ine wear and led to spark plug fail ure.
Aviation Safety Digest 125 I xi
�Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type
Rating
Record
number
15 Dec 84
Glasflugel Libelle VH-GGO
Glider
8431038
1419
Woodbury Tas
60
219
58
Glider
The pilot reported that an aerotow to 2700 feet agl seemed to be accomplished quickly. When the glider had descended to 1400 feet
the pilot rejoined the circuit but then considered that the altimeter was defective. She believed that sufficient height remained to
permit a land ing at the strip and carried out a low, tight circuit. However, as the turn onto fi nal was comp leted an immediate landing
flare was req uired. A heavy touchdown occurred and the aircraft came to rest 175 metres after the strip boundary.
Faulty alignment of the 'thousands' needle in the altimeter had led to the pilot mis-setting the heigh t of the st rip prior to take-off.
The indications she read from the instrument were therefore 1000 feet in error.
17 Dec 84
Cessna 182-A VH-KLJ
Commercial
8431039
1511
Interview River
221100
60
Ins trumen t rating class 4
The pilot decided to land at the strip to check on the wel fare of two mining company employees working in the area. During the latter
stages of the landing roll the nosewheel entered a soft area and dug in, causing the ai rcraft to overturn.
As the mining company's base radio was unserviceable and the ground personne l were not expect ing the aircraft, the pilot was
not able to establish the condition of the strip. Although it appeared serviceable from the air, the strip contained a section where
water from recent rain had accumulated and resulted in the surface in that area being soft and wet.
18 Dec 84
1511
Beech 77 VH-H BI
Archerfield Old
8411 058
Flig ht instructor grade 1 or 2 with
instrument rating
The aircraft was being taxied across another runway towards a taxiway. Approach ing the edge of the flight strip, the ins tructor
noticed a 20 centimetre deep spoon drain in the path of the aircraft. He took control a nd attempted to avoid the drain but the
nosewheel entered the drain and broke off. The presence of the drain was indicated on a diagram of hazardous taxying areas
available to pilots but the area was not marked by cones.
The aerodrome was being used for taxying purposes, as an all-over field, contrary to approved procedures. The pil ot saw the drain
obstruction, whic h was situated just outside the flight strip, too late to take effective avoiding action.
'
39
800
Commercial
387
22 Dec 84
Piper 25-235 VH-S PE
Private
8431040
1951
Dooen Vic
33
1915
290
Instrument rat ing c lass 3
Prior to the flig ht the pilot was given details of the paddock in which the glider was located, by the glider pilot. Th is info rmation
included reference to power lines on the western side. An inspection run into the west was performed at 300 feet agl and as a ru n at a
low height towards the east was commenced the landing gear struck a power line suspended 9 metres above the ground. The aircraft
s truck the ground in a vertical nose down attitude and came to rest inverted.
The power line ran obliquely across the paddock from a line of poles paralleling a rai lway track. There were no supporting poles in
the paddock to alert the pilot as to the whereabouts of a power line and he assumed tha t those running next to the railway were the
ones mentioned in the briefing.
22 Dec 84
Reims 172H VH-EDZ
None
8411060
1447
Ouilpie Old 3W
50
None
The aircraft was parked, with controls locked and doors unlocked, by the owner who retained the ignition key. Later, another person
entered the aircraft and operated a number of controls before experimenting with a car key in the ignition switch. The eng ine started
and the aircraft took off from the position at which it was parked. The occupant attempted a landi ng but thi s was uns uccessful as full
power was still selected. Some time later the engine stopped due to fuel exhaustion and the aircraft glided into scrub near the town.
The occupant was later apprehended by local Police .
The thief had received no pilot training and was not capable of adequately controlling the a ircraft.
26 Dec 84
Piper 28-151 VH-PZC
Private
8411061
1335
Miles Old 32NW
43
334
180
None
The pilot reported that, after commencing the take-off with flaps up, he selected 10 degrees of flap and rotated at 60 knots. Although
the aircraft became airborne it did not climb normally. The aircraft struck a telephone line near the end of the strip and then landed in
a paddock before passing under a power line. With full power still applied, the pi lot attempted to c lear a fence but the wing leading
edges struck fenceposts. The aircraft landed heavi ly and came to rest 478 metres from the strip end.
The lake-off performance had been degraded by a loss of engine power resulting from unserviceable piston rings in two cylinders.
The aircraft was being operated at some 120 kg in excess of the weight extracted from the performance charts as being the
maximum allowable for the strip length.
26 Dec 84
Glasflugel 210B VH-GGY
Glider
8451034
1245
Narrikup WA
48
645
218
Glider
The glide r was launched by being towed beh ind a motor vehicle. After the glider became airborne, the pilot s ignalled to the vehicle
driver to s low down. The vehicle driver slowed the vehicle too quickly, the tow rope slackened and t he rope drogue deployed . The tow
rope then released from the glider. Because of the posi tion of the tow rope, below the gl ider, the pilot did not immediately lower the
nos e , the glider stal led at about 15 feet agl and landed heavily.
30 Dec 84
Cessna 182L VH-EFN
Private
8431041
1545
Willaura Vic
59
193
114
None
After flying in the local area for a time, the pilot entered a long straight-in final approach for the easterly strip he had used for take-off.
From a distance he observed that the wind was a light southerly. Following a s light bounce on touchdown, braking was in itiated but
the aircraft seemed to be travel ling faster than normal. The pilot, believing that he had landed with a tail-wind, turned the aircraft to
the north-east to increase the landing roll available. The aircraft overran the area in to a fen ce and firebreak.
The approach s peed used was 12 knots faster than that recommended in the land ing chart. The bounced landin g, s lippery grass
surface and use of other than maxim um braking increased the stopp ing distance requi red. The direction of turn chosen by the pilot
to increase hi s stopping dis tance was downh il l and wit h a tailwind compone nt. The presence of telephone lines at the end of the
strip precluded a go-around.
xii I Aviation Safety Digest 125
Pin that airspeed
L aunching a glider is a critical p h ase of flight , for if it
becomes necessar y to abandon the launch the glider
pilot is likely to find himself at a low altitude and with
little time to select an ou tlanding ar ea. It is of cour se
standard practice to consider during preflight
prepar ation alternative courses of action should launch
problems arise; addition ally, the flat , open terrain
characteristic of many gliding centres often presents
numerous outlanding options.
Notwithstanding th e latter factor , emergencies such
as rope or wire breaks, or winch failures, continue to
result. in unn ecessary or excessively severe accidents. In
many of these accidents, investigation indicates that the
central problem is that most b asic and important
aspect of piloting, airspeed control. An accident
involving an IS28 glider was a case in point.
The accident
Prior to launch normal procedures were followed for
the attachmen t of the tow rope to t he glider's aero-tow
release mechanism. The takeoff proceeded uneventfully
and after lift off the glider went to the 'low tow'
position (i. e. below the tow aircraft). At about the
same time the tow rope suddenly released from the
g lider.
The g lider pilot subsequently reported that he
p ushed forward on the control column and checked his
airspeed, although he had no recollection of what the
airspeed was. He started a left turn towards a clear
area near the departure end of the strip but found he
was unable to control th e aircraft as 'the right wing
kept goin g up' a nd he was 'unable to stop it'.
Initial contact with t he grou nd was made by the left
wingtip; the a ircraft then cartwheeled and the nose
impacted heavily.
Both the p ilot and his passenger were certain th at
the tow rope release control h ad not been activated.
Investig ation confir med that the aero-tow release unit
was faulty and h a d released by itself.
Comment
The sequence of events leading up to this accident thus
started when th e tow rope separated from the glider at
an altitude of a bout 50 feet AGL. Had t his not
happened an accident would not have occurred. On
the other h and , because it did happen , it did not have
to result in an acciden t: there were several suitable
outlanding areas within easy gliding range .
Witness reports stated that the left turn had been
very steep, while some also mentioned th at the
aircraft's nose was abnormally high. In combin ation
with th e impact evidence (e.g. wreckage distribution) ,
this was consistent with a loss of control prior to
impact; sp ecifically, a stall and incipient spin.
The critical action after a sudden inadvertent release
in circumstances such as these is to 'pin' the correct
speed for:
• best g lide performance ; and
• continued safe flight.
Clearly, if the firs t point is satisfied then so is the
second ; nevertheless, given the number of occu rrences
Aerial view showing takeoff flight path and areas (arrowed)
suitable for forced landing.
in which pilots fai l to maintain adeq uate airspeed, it
bears emphasis.
In this case the glider should have been able to cover
a distance of 1500 feet from an altitude of 45 feet AGL
a t an airspeed of 55 knots . As it was, it covered
nothing like that. The pilot not only failed to 'pin' the
best glide speed, but he also allowed the speed to d rop
below that necessary for safe flight. H is attempt to
'pick up' the left wing with aileron when he became
alarmed by the steepness of the left tu rn would only
have increased the glider's susceptibility to spinning
given the low airspeed.
Conclusion
No aspect of piloting is more fundamental th an that of
airspeed control, yet accidents of this type continue to
occur. The message is as valid for p ilots of powered
aircraft as it is for glider pilots, not only if they
experience a power loss, b u t also for a whole range of
operations which involve manoeuvring close to the stall.
T o summarise , if you are faced with an outlanding
or forced landing, maintenance of adequ ate airspeed is
of paramou nt importance. In t he worst case where a
clear area is not available, a controlled, wings-level
crash is fa r p referable to an ou t -of-control crash.
T he investigation of a large number of accidents
continues_ to prove that, regardless of obstructions and
terrain, if the aircraft is u nder control at impact you
have a fair chance of 'walking away from it' , but if it is
not you are very lucky if you do •
Aviation Safety Digest 125 I 13
�:.······································ ................. ····················· ··········· ······························································································ ························· ·······················
Drum refuelling
A Hi ller 12E pilot landed alongside a homestead for
refuell ing after about on e and a half hours of cattle
mustering. He intended carrying out the job with a
portable electric fuel pump inserted in the top of a
drum of AVGAS.
Because the electric pump did not have a standpipe,
the drum had to be placed on its side to ena ble fuel to
reach t he b ung hole in to which the pump had been
placed. To power th e e lectric p um p, the pilot
d isconnected the m ain leads from the a ircraft battery
and connected the leads from the pump to the battery
termin als with alligator clips .
As the pilot was about to put th e fuel nozzle into the
helicopter's tank, the delivery hose came off the electric
pump, and fuel started to gush o ut a ll over him. (The
pilot later commented that wh ile the delivery hose
fitted tightly onto the pump , it was not clamped.)
In order to stop the p ump from running and thus
stop the fuel from pouring ou t, the pilot grabbed the
leads from the pump and pulled them off the battery.
However, it seems that, as the alligator clips came off
the battery terminals, t hey touched, and caused
electrical arcing.
T h e fuel ignited.
Inside t he homestead the prop erty owner heard a
loud 'wh oomph' and then a scream . H e ran outside
and saw that both the pilot a n d the helicopter were on
fire. He managed to grab h old of t he pilot and
ext inguish the fire in his clothing by rolling him on the
ground.
The pilot, who had been wearing long trousers and a
long-sleeve shirt, sustained burns to about 20 per cent
of his body, primarily to his hands and from the waisl
down. The helicopter was destroyed.
*
*
*
Figure 1
Refuelling from drums is almost invariably done as
an 'in-t he -field ' operation. Many of those who use
drums do so often and as a matter of routine; thus, the
practice of completing the refuell ing quickly and
cutting corners tends to arise.
In fact, there are a number of regulations, orders
and time- proven procedures applica ble to drum
refuelling. Like m ost standard procedures these are
intended or have been developed , not to m ake life
difficult for those to whom they apply, but rather to
serve safety and preserve life and property . Before
reading the rest of this article, it may be a worthwhile
exercise to review the accident described above and
make a note of the number of deficiencies in refuell ing
techniqu e which you can identify; the two basic a reas
you should consider are fuel quality control and fire
prevention. Having done that, compare your knowledge
to the information presented below.
Fuel qua lity control
The drum to be used should be checked before
commen cing refuell ing to ensure that (a) its m arkings a nd the contents are consistent, and
appropriate for the use intended;
(b) it is not aged;
(c) there has been no obvious contamination during
storage; and
(d) it contains no free water. A positive method , such
as the use of water detecting paste or paper, is a
necessity.
Before pumping, the drum should be stood on its
end and tilted by placing a piece of wood 50mm thick
~nder o ne side, so that the large bung is on the high
side. If the drum is left lying on its side, the suction
standpipe, designed so that fuel cannot be drawn from
Figure 2
Fue lling from drums
When switching to a fresh drum (Fig. 2)
•
Mount filter/separator or fuel monitor on side of drum, and
bond correctly (Fig. 1).
•
Remove nozzle from aircraft fuel tank.
•
Cap aircraft fuel tank.
•
Open large bung and insert pump suction to bottom. Large
bung should be on high side of drum.
•
•
•
Remove bonding and nozzle from aircraft vicinity.
Bond discharge nozzle to aircraft before opening aircraft fuel
tank.
•
Remove pump from empty drum.
•
Reseal empty drum.
Fuelling nozzle or hose should be inserted as far as possible
into the aircraft fuel tank to minimize splash filling.
•
Remove filter/separator or fuel monitor.
•
Remove bonding .
Commence delivery.
with in 80mm of the drum bottom, cannot do its
job - water or other contaminants could be drawn from
the drum . Further, as the accident detailed above
showed, leaving the drum on its side can increase the
possibility of fire.
H aving been tilted, the drum should then be allowed
to stand for as long as possible, preferably one hour, but
not less than 15 minutes, to let water or sediment settle
to the lowest point.
If refuelling from jerry cans etc., the fuel should be
filtered through a mesh sffainer, aviation-type, water·
trap funnel.
If refuelling with a pump fitted with a filter , check
t he filter before and after refuelling for signs of water
and other contamina n ts.
Also note that, if p ossible, drums should be taken to
the a ircraft on t he tra y of a vehicle, not rolled along
the ground. If it is necessary to roll the drums, they
m ust be given the longest settling period possible before
refuelling is commenced.
•
•
•
•
•
•
Fire prevention
.,,.._...,c._ _ _.-.;. .
Photograph shows proximity of fuel drum, battery and helicopter. Arrow indicates remains of fuel nozzle and hose.
14 I Aviation Safety Digest 125
Getting the correct grade of clean fuel into your
aircraft's tanks is half the battle - the other half consists
of doing it safely:
• The aircraft and the fuelling equipment should not
be closer th an
- 5 metres to any sealed building;
- 6 metres to any other stationary aircraft;
- 15 metres to any exposed public area; and
- 9 met res to any unsealed building for an aircraft
with a tvrrow not exceeding 5700 kg, or 15 metres for
an a ircraft with a M T OW in excess of 5700 kg .
• Static leads should be connected to ensure bonding
between the d rum, the pump and the identified
•
•
aircraft earthing point. If there is a ground earthing
point available, the refuelling equipment and the
aircraft should be earthed.
The aircraft should be positioned so that it can be
quickly moved to safety in an emergency.
The area in which refuelling operations are being
conducted is a 'No Smoking' area. Persons operating
fuelling equipment should not carry matches,
cigarette lighters or objects which could constitute
an ignition hazard and no person should smoke or
use a naked flame within 15 metres of the aircraft and
the ground fuelling equipment.
Fire extinguishers should be positioned in the
vicinity of the aircraft and the fuelling equipment.
Particular attention should be given to possible
sources of ignition such as arcing between metallic
parts of electrical circuits and components.
Fuelling plant (ie the fuelling system) must be fitted
with an isolation switch between the battery and
electrical services.
Exposed electrical terminals should be protected by
insulating boots or cove rs.
All batteries should be suitably covered to prevent
accidental shorting of the cells and should be
provided with adequate means of natural
ventilation.
All connections should be secured with spring or
lock washers to prevent accidental loosening of
connections while in use.
Conclusion
All of those individuals involved in drum refuelling are
urged to familiarise themselves thoroughly with the
advice contained here and, for safety's sake, to put it
into practice•
Aviation Safety Digest 125 I 15
�'1<~
Wasted resources
Airborne direction finding
A Piper PA28 was on a VFR flight in Central Australia.
The pilot, who held a Class 4 instrument rating, had
nominated a SARTIME of 1030 hours GMT. His flight
plan estimate for his destination was 0950, which
coincided with last light. No arrangements had been
made for runway lighting at the destination.
At about 0950 the Flight Service Unit (FSU) for the
area received a phone call from a person waiting for
the Piper, advising that it had not arrived as expected.
Even though the nominated SARTIME had not expired
an uncertainty SAR phase was declared because:
• daylight had expired;
• runway lighting was not immediately available; and
• it was not known at that stage whether the pilot held
an instrument rating.
At 1037 hours the SAR phase was upgraded to that of
Alert.
En route airfields were checked, while runway lights
at those airfields, and at possible diversion strips, were
turned on where available. The aircraft's owner was
contacted and was able to give SAR co-ordinators
information on the pilot's qualifications and
experience.
No contact was made with the PA28, so at 1145 a
Distress phase was declared and a full scale search
planned, starting with a high-level Emergency Locator
Transmitter (ELT ) sweep during the night by a Department of Aviation Merlin. In all, a total of nine aircraft
was involved, including a RAAF Orion which took off at
first light the next morning.
At 2143 hours on that morning, the missing PA28
arrived at its destination.
It transpired that the pilot had experienced
navigational difficulties and, when he found himself
rapidly running out of daylight, had carried out a
precautionary landing some 10 or so miles from his
destination. He had made R / T calls on the area VHF
frequency, but had not been able to contact anyone.
No consideration had been given to activating the ELT
'because he had not crashed and was in no immediate
difficulty'. An uneventful night was spent on the
ground.
The next morning the brief flight to the destination
was completed, and the pilot learnt that he had been
the subject of an extensive aerial search.
Discussion
Before addressing the SAR aspects of this incident, some
observations about the pilot's flight planning are
warranted.
The plan submitted by the pilot contained no details
of true airspeed, wind velocity, magnetic heading or
ground speed. It was obvious that he had not allowed
for wind velocity in calculating headings and ground
speeds. As it was, the relevant forecast wind amounted
to about a 15 knot headwind component. There is little
doubt that the pilot's failure to allow for this
contributed to his navigational problems.
A considerable number of GA pilots submit flight
plans in which the effects of wind velocity have not
been included. Given that thorough preflight
preparation is the basis of flight safety, this is a poor
practice. In this particular instance accurate planning
was even more essential because of the· relatively
featureless terrain en route.
As a second point on planning, the pilot's failure to
arrange for runway lighting at his destination also was
inconsistent with good airmanship and regulations.
Turning to the search and rescue activities, we
Australian pilots enjoy one of the best air traffic
systems in the world. One aspect of this is that, if we
nominate a SARTIME and do not cancel it as intended,
we can rest assured that SAR action will rapidly
commence.
Here, the pilot was doubtless well-meaning in
thinking that as he had not crashed, he should not turn
on his ELT . However, the fact was that he had not
arrived at his destination and had not cancelled SAR.
Accordingly, the 'system' sprang into action, eventually
involving nine aircraft and costing, by one estimate,
$40000 , in what turned out to be a waste of resources.
Activation by the pilot of his ELT would have quickly
been detected by the Departmental aircraft, and
resolved the issue.
The needless expense incurred was important, but
the needless use of resources was even more so. Had a
genuine emergency arisen, valuable resources may not
have been available because they were already involved
in this pointless exercise •
In brief
Some sympathy can be felt for the holder of a
Student Pilot Licence who lost directional control of
his Cessna 180 while practising solo circuits. He had
about 40 hours total flight experience, nine hours of
which had been on the type.
After two successful touch-and-go landings he
brought the aircraft in for a 'full stop'. At about 20
knots during the latter stage of the landing roll, the
aircraft groundlooped to the left resulting in the
right wing and elevator striking the ground. The
wind was calm at the time.
16 I Aviation Safety Digest 125
The old adage 'A landing is not completed until
the aircraft has stopped' applies particularly to types
such as the Cessna 180 series. Even pilots with
considerable experience on type have been caught
out. Rudder, ailerons and, most importantly,
differential braking, must be applied to maintain
directional control during the landing roll out.
It is far cheaper and considerably more
convenient to replace worn brake pads than to
rebuild the whole aircraft! •
This article describing an actual airborne Direction Finding (D/F) intercept and escort was prepared by
Air Traffic Control officers from Townsville. It Illustrates both the value of this rescue technique and the
important safety contribution alert and concerned observers can play by quickly reporting, and trying to
aid, a pilot apparently in trouble.
South-east stream weathe r frequently produces poor
flyin g conditions along the North Queensla nd coast and
ranges. It was in such conditions that the pilot of a
Cessna 182 bound for Cooktown, and thirty minutes
south of Cairns, began to encounter navigational
difficulties. While the pilot was reporting north of
Cardwell, in VMC , a number of telephone calls were
being received by Townsville Operational Control
Centre personnel advising that a light aircraft had been
sighted in the Herbert River valley, circling and flying
up and down the river in extremely poor conditions.
One of the callers had been a private pilot and he was
exceedingly apprehensive, knowing that the valley basin
narrows rapidly to form the Herbert River Gorge with
the Blencoe Falls at its head, and that heavy rain was
falling .
Despite reassurances tha t the pilot had re ported that
she was divertin g back to T ownsville in VM C a n d was
within ten miles of the coast li ne, a cropspraying pilot
at Ingham , in heavy rain , pushed his airc raft out clear
of its ha ngar a nd selected appropriate frequencies to
contact the pilot and assist her with local knowledge.
In Townsville at the Rescue Co-ordination Centre,
telephone pager numbers were being rung at 9.32 a.m.
to alert the stand-by crew of the National Safety
Council of Australia (SAR , Townsville Section). At 9.43
a.m. as the pilot of the NSCA Bell 212 helicopter was
being briefed, other crew members were towing the
large yellow helicopter on its trolley from the hangar.
At 9.52 a.m. the helicopter was airborne to commence
a O/ F routine which had been discussed in theory but
had yet to be tried in practice.
In the meantime, the pilot of the Cessna, unsure of
her position but believing she was still close to the
coast , had found a gap in the clouds and had
scrambled through it at the end of the valley, and was
h eading westwards with 110 minutes of fuel remaining.
This heading was taking h er away from the cloud
Aviation Safety Digest 125 I 17
�Attention to detail
The incident discussed in this article highlights a number of the factors often associated with the
wrong grade of fuel being pumped into an aircraft's tanks. It also illustrates the value of that muchmaligned commodity, paperwork, and attention to detail.
A light twin had made a scheduled landing at an
uncontrolled airfield. It was the early evening, and
fuel and lights had been arranged by the operating
Company. When placing this order by telephone the
Company operations officer had not , however,
stipulated the grade of fuel required.
After landing, the pilot taxied to the refuelling
area where the refueller was waiting for him.
Lighting in the are a was poor.
Three hundred litres of fuel were added. Shortly
afterwards, the pilot noticed on the documentation
that his a ircraft had been topped up with Jet Al
instead of AVGAS 100/ 130.
The aircraft was moved to a clear grassed area ,
the fuel drains opened , and syphon hoses used to
drain the fuel tanks. Fuel was drained and the
system flushed for 1 Y2 hours , during which time
numerous checks of the fuel in the system were
completed against a known pure sample of AVGAS
100/ 130. Onlo/ after this process had been completed
and the pilot was certain that all J et Al had been
purg ed from the light twin 's system was the aircraft
fuelled again , this time with 800 litres of AVGAS
100/ 130.
Moving the aircraft to an area cle ar of that in
which the fue l draining had been done , the pilot
then started the engines and ground-ran them for 15
minutes, care fully monitoring all engine instrument
indications. Deciding that the fuel system was now
uncontamina ted , the pilot continued with the flight,
which was concluded without incident.
Factors identified as being relevant to this
occurrence were as follows:
• The required fuel type was not specified when the
order was placed by telephone.
• The refueller thought the a ircraft had gas turbine
engines.
• The refueller did not notice the AVGAS decal near
the fuel caps.
• Lighting in the fuelling area was poor.
• The pilot did not monitor the fuel grade on t he
bowse r in use, nor did he personally confirm the
type of fuel coming ou t of the pump.
As stated above, most of the factors.appea r
regularly in this type of occurren ce .
Perhaps in conclusion several observations could
be made. First, in the final analysis, just what gets
pumped into an aircraft fuel tanks is the
responsibility of the pilot-in -command. On the
credit side of the ledger, by checking the
documentat ion carefully, th is pilot discovered the
er ror in time to take remedial action. Despite some
pilots' beliefs to th e contrary, most of the paperwork
associated with aviation serves a valuab le safety
purpose, and the tempta tio n most of us occasionally
exp erie nce to sign withou t re ading, or ignore the
paperwork comple tely, can be an unhealthy
practice. Finally, the thoroughness with which the
cont aminated fue l system was purged an d the safety
measures which were taken are worthy of a ttention •
Airborne direction finding (Continued}
enshrouded , rain d renched mountains of t he Great
Divide .
The NSCA Be ll 212 is fitted with a n O cea n Applied
Resea rch ADF 320 'Searchmete r' and at 9 .57 a. m. the
o perator got an initia l bea ring . A fi r m bea ring was
obtained at 10.03 a. m ., a nd as the helicopter took up a
track divergence to obta in a second bearing the Cessn a
was turn ed o nto a reciprocal heading, on reduced
power to conser ve fuel. As the Cessn a cont inu ed
towa rds a rendezvous with the helicopter , st aff in the
Rescue Co-ordination Centre plotte d the bearings given
by th e he licopter crew, determined that the wea ther a l
Ch a rters T owers and othe r aerod rom es ne arby
precluded a n en rou te dive rsion, and c hecked to e nsure
t hat the Cessn a and he licop ter would b e clear of an
area in which unexploded bombs were due to be
de tonated.
At 10 .30 a. m . visua l con tact was m ade, 56 n m wsw
of Town sville, and the Bell 212 positioned astern to
18 I Aviation Safety Digest 125
esco rt the Cessna to Townsvillc. T he accom panyi ng
photograph was ta ke n at tha t lime .
By 11. 20 a.m . both ai rcraft had landed and the
Cess na pilot gratefu lly accepted the offer o f a cup of lea
fro m RC:C: sta ff.
Following this rescue the D/ F procedure was further
refined , and in a t raining exercise three weeks later the
pilot of a Cessn a 310 sim ulated the classic situatio n of a
pilot unsure of position, in indiffere nt wea ther with
lim ited fuel a nd daylig h t rem aining, and flying low
level in rough country. The Cessn a was 60 miles nort h west of Townsville. The NSCA Bell 212 was 'scram bled',
established co mmunication with the 'lost' aircraft, and
a bearing and he ading to take u p were d etermined
within 5 min utes of lift -off. Further bearings quickly
followed and a n intercept poin t was calcul ated by RCC
staff. T h e Cessn a's position was established only 15
minutes after the liftoff of the Be ll 212.
Airbo rne D/ F does work! •
ELTs and false alarms
Considerable con cern has been expressed within some
sections of the aviation industry over the large n umber
of ina d vertent a ctivations of Emergency Locator
T ransmitters (ELTs). T here are two main consequences
of these 'fa lse alarms' :
• a high commit ment of finance and resources which
en ds up as a complete waste; a nd
• the possible diversion of search and rescue services
awa y from genuine em ergencies .
For example, d uring t he last three yea rs in Australia,
there h as been a n average of a bout 140 false alarms
each year, tha t is, about three a week . It should be
fairly obvious that this q uickly develops into a
sig nifi ca nt and wasteful drain on valuable resources.
Research conducted in the United Sta tes fo und that
the inadvertent activa tion of ELTs could be d ivided into
fo ur broad categories, and deter mined the rate of each
category as follows:
1. Mishandling of ELT
2. Hard landings
3 . Other G-switch activa tions
4 . Unknown
28%
21 %
16 %
35%
Mishandling
This category refers p rimarily to the handling of
portable uni ts d u ri ng transportation and/ or storage. It
is the c ategory which could be most easily eliminated
by pilots a nd LAMEs simply by the removal of the
b at teries or battery pack before transporting the
instru ment . In most cases this is a relatively
straig ht forward procedure. Terminals may be taped
over to prevent sh ort circui ting. (When re-installing a
portable ELT in a n a ircraft , always turn it on to check
it fo r normal operation. H owever, ensure that you have
n otified t he Dep artm ent of Aviation before conducting
th is test. )
Simply switching an ELT to the 'disarmed' mode
during storage or tr a nsit is no guarantee that it will not
be accidenta lly activa ted by a bump, an inquisitive
ch ild , electrical shorting or other causes. No batteries
mea ns no signal ...:._ it's as simple as t hat. This practice
a lso safeguards agai nst the danger of a flat battery in
the eve nt th a t o ne d ay you becom e a downed pilot in
need of help .
Mention should aJso be made here of the inadvertent
activation of ELTs by owners, LAMEs or pilots working
on a ircraft. A typical occurrence of this was reported
fro m Darwin som e m onths ago wh en a person working
on the tail se ctio n of a n aircraft disconnected the ELT's
external antenna but did not switch the unit off and
subsequently activated the tran smitter , probably by a
knock which activate d t he G-switch. This incident gave
rise fo r further concern when investigators fo u nd on
insp ection tha t the ELT had .been incorrectly installed ,
such that its radia ted power would have been reduced.
Like any piece of a ircr aft equipment , EITs should be
installed o nly by q ua lified persons and in accordance
with th e approved procedures ; while the same advice
applies for a ny mainten ance being completed which
m igh t affect a n ELT.
Hard landings
For aircraft with permanent EL.:r installations , hard
landing activations can be detected by listening on
121.5 on the aircraft's radio after engine shutdown.
Miscellaneous
T he third category, 'Other G-switch activations', refers
generally to false alarms set off during shipment of the
transmitter, either by the manufacturer to an outlet or
by an owner or LAME for purposes of repair. H ere
again, the answer is to ensure that any ELT shipped to
you or by you has its batteries removed and transported
separately.
O n occasions suggestions have been raised that ELT
signals should be made audible to the unaided ear or
to the crew in the cockpit, thus eliminating the
problem . Unfortunately this presents considerable
technical problems and would be prohibitively
expensive.
VSBs
The generic term ELT applies to transmitters which are
carried in a fixed aircraft mounting. Some pilots also
carry portab le transmitters, known as VSBs (VHF
survival beacons). T his practice is encouraged, but it
should be noted that as a result of inadvertent
activations, transmitters with G-switches are no longer
approved for use as VSBs .
Conclusion
Currently some of the design em phasis in newgeneration ELTs is being placed on providing a
foo lproof warning of inadvertent activation which will
not overburden owners' wallets. In the meantime,
observati~n of the simple precautions detailed above
should ensure that the safety of airmen genuinely in
need and the availability of valu able resources are not
compromised by false alarms •
Aviation Safety Digest 125 I 19
�Helicopter ground resonance
Helicopter ground resonance is a phenomenon which can begin without warning, develop with alarming
rapidity and culminate in disastrous consequences.
The rapidity with which ground resonance can d evelop
is one of the most significan t factors which e merges
from acciden t investigations. T he two following
summ aries a re typical of this type of accident.
The accidents
A student helicopter pilot was undergoing an
instructional sortie in a Hughes 269C. The flight was to
consist of operations from pinnacles, slopes and
confined areas; and autorotations. The first three
circuits flown were into a pad on a large ridge where a
go-around was initiated from a low hover. A landing
was effected off the fourth approach, and the throttle
was closed to flight idle while the instructor and
student discussed the circuits.
After this brief interval the student opened the
throttle from the flight idle setting (2000 RPM) to 2500
RPM and then started to raise the collective lever to
increase the RPM to the takeoff setting of 3200 .
However, before that figure was reached a lateral
vibration commenced , so he lowered the collective. The
instructor, quickly assessing the vibration as the
proba ble onset of gr~und resonance, t~ok control and
increased collective and attempted to hft off, although
at that stage full takeoff RPM had not been achieved.
The vibration increased and the helicopter's nose
pitched up. Even when the normal takeoff .
.
collective/ power setting was reached the hehcopt~r did
not lift off, so the instructor bottomed the collective
and closed the throttle.
Notwithstanding this, the vibration continued, to
such an extent that the two pilots found it difficult to
see inside the cabin and were continually thrown
against each other. The helicopter began to break up .
Engine noise increased so the instructor attempted to
close the engine down with the mixture control. T his
did not seem to work, so the student turned off the
20 I Aviation Safety Digest 125
magneto switches. Shortly afterwards the heli~opter
caught fire. When the movement of the rotating blad~s
ceased the pilots evacuated the machine and watched lt
burn out from a safe distance.
The Accident Investigation did not determine the
cause of the onset of ground resonance, but concluded
tha t , once it had started , it was developed and
increased by wrongly set pressures in the oleos. The
instructor correctly identified the condition, but by the
time he attempted to lift off the resonance was so
severe that the helicopter's efficiency had been
compromised to the extent that the takeoff could not
be effected.
In the second accident, an Aerospatiale SA 319B
(Alouette) was ground taxiing for takeoff when the
ground resonance occurred. The pilot lifted the
helicopter off the ground and the resonance ceased.
However, the main rotor then started to vibrate
severely so the pilot landed his aircraft. Ground
resonance recommenced, with such force that one main
rotor blade struck the cabin roof and severed the tail
boom . The aircraft turned through 180 degrees as it
sustained further damage .
Inflight main rotor imbalance had been caused by the
failure of a blade damper, which in turn resulted
from the seat displacement of a one-way valve by a
portion of perforated plate. Blade imbalance then
induced the failure of a main rotor spacer cable. As
the Bureau of Air Safety Investigation report
concluded, the ensuing loss of control necessitated a
landing, as a consequence of which severe ground
resona nce, induced by the blade imbalance , occurred.
Ground resonance
Ground resonance can be defined as a vibration of
large amplitude resulting from a forced or se lf-~nduced
vibration of a helicopter in contact with or resting
upon the ground. The pilot will recognise ground
resonance from a rocking motion or oscillation of the
fuselage and, if early corrective action is not taken, the
amplitude can increase to the point where it will be
uncontrollable and the helicopter will begin to break
up. The forces involved are so great that the helicopter
can be thrown onto its side or even inverted. Pieces
d etached from the helicopter during the break up
process, e.g., rotor blades, possess considerable energy
and can be thrown some distance, with the obvious
danger of injury to bystanders or damage to other
aircraft.
Causes
The initial vibration which causes ground resonance
can already be present in the rotor head before the
helicopter comes into contact with the ground. Ideally
the disc should have its centre of gravity over the centre
of rotation, but, if for any reason its position is
displaced, a wobble will develop, the ef~ect beii:ig
similar to an unbalanced flywheel rotating at high
speed. Ground resonance can also be i?duced by the
undercarriage being in light contact with the ground,
particularly if the frequency of oscillation of the oleos
and / or tyres is in sympathy with the rotor h ead
vibration.
(a) Rotor head vibration. Rotor head vibration can
be caused by:
• Blades of unequal weight or balance. Blades .
should be correctly weighted and balanced durmg
manufacture, but flight in icing conditions cai:i
cause imbalance due to the uneven accumulation
of ice on the rotor blades. Moisture absorption or
blade damage can also be a cause of imbalance .
• Faulty drag dampers. With a three-bladed rotor
system the blades should be equally spaced 120
degrees apart . If a damper is sticking or is allo~ing
uneven spacing of the blades, the centre of gra~1ty
of the rotor will be displaced away from the axis of
rotation (Fig. 1).
/
I
I
.....-
/
-..............._
"" \
"
\
120°
I
120°
l
\
\
I
'
,(
I
I
I
\
...._
"
/
/
--
- / /I
/
- --""
""' \
\
I
\
Fig. 1. Effect of faulty drag dampers.
Aviation Safety Digest 125 I 21
�•
•
Faulty trackz'ng. A rotor which is greatly out of
track may set up an u nbalanced condition which
wi ll be transmitted through the helicopter. This
type of imbalance usually results in nothing more
than a rough helicopter and a beat in the cyclic
stick. However, if enough track imbalance exists, it
is possible that a combination of factors may be
encoun tered which woul d result in ground
resonance being induced (Fig. 2).
(b) Fuselage vibration. Fuselage vibration can be
caused by:
• Mislanding, aggravated by continuous lateral
movement of the cyclic stick.
• A taxiing takeoff, or run-on landing, over rough or
uneven ground.
• Incorrect or unequa l tyre pressures; incorrect or
unequal oleo pressures. Incorrect tyre and/ or oleo
pressures can markedly alter the resonance
response of the underca rriage system of a
helicopter. If the reson ant response of the
degraded undercarriage system is in sympathy with
a rotor head vibration, however induced, ground
resonance will occur.
Recovery action
T he more appropriate of the following actions must be
taken:
•
Take off immediately if rotor RPM are avai lable.
Rotor RPM should always be maintained in the
operating range until the final landing has been
completed.
•
Shut down immediately if takeoff RPM are not
I
I
I
I
• •
Fig. 2. Effect of faulty tracking.
available or if takeoff is not practicable; i.e., lower
the collective , reduce power and apply the rotor
brake a n d wheel brakes (where applicable).
The emphasis must be on decisive action, based on a
prompt analysis of the circumstances.
Note that with the advent of rigid rotor systems,
helicopters fitted with such systems are far less likely to
be affected by ground resonance than those types using
a fully articulated rotor system and an articulated
undercarriage •
In brief
The pilot of a Hughes 300 helicopter was making a
prelanding circuit after a 40 minute training flight
when the fuel low pressure warning light appeared
to flicker 'on'. As a consequence he shortened t he
circuit and carried out a faster th an normal
approach, but when slowing the machine to a hover
at about 30ft AGL the main rotor RPM decayed
rapidly and the helicopter began rotating to
the right.
After several revolutions the pilot almost
succeeded in regaining control bu t th e right skid
struck the ground and collapsed, causing the
helicopter to roll on to its side. The pilvl was fully
restrained with a shoulder harness and lap strap
which effectively prevented injury during the impact
sequen ce.
Subsequent investigation showed there was still
some 18 litres of fuel remaining in the tank, even
after some loss through the tank vent following the
accident.
It had been observed by t he operator on previous
occasions th at the sun's rays striking various g lass
domed warning lights at a specific angle could give
the impression of illumination. On this occasion the
sun was to the left rear of the helicopter as the pilot
turned downwind in the circuit. It was thus
prob able that the sun's rays striking the fuel low
pressure warning light had caused a momentary
illuminating effect •
22 I Avi ation Safety Digest 125
A PPL holder who had flown only two hours during
the previous three months was taking six children for
a local private flight in his Cessna 206.
The airstrip was a paddock 317 metres long with
a 5 degree slope and was covered in 4 inch high
grass. On fi nal approach the pilot selected full flap
and reduced airspeed to 60 knots prior to the flare.
Despite this, the aircraft floated and failed to touch
down until more than half way up the strip. It then
bounced back into the air and the pilot, concerned
at the limited length of strip remaining, decided to
go around.
The aircraft struck a gorse bush located at the
airstrip boundary where the ground sloped abruptly
upward for about 10 ft. The pilot raised the nose
and man aged to retain sufficient con trol to keep t he
aircraft tracking straig ht up a ridge. It then stalled
and 'mushed' into some fem and bracken, coming to
rest 40 metres from the end of the strip. The p ilot
and his young passengers fortunately were uninjured
and vacated the aircraft safely.
The topography of the airstrip an d the high
terrain near one end dictated that the pilot was
committed to land after passing the threshold.
Locally based agricultural pilots commented that the
area was bad for gusts and subject to changeable
wind conditions due to mountainous terrain to
the west.•
Make your
weather
decision
while you
still have
a choice.
BEFORE TAKE-oFF
• Get, read and assess all
meteorological information.
• Prepare a flight plan on the basis
of that assessment, not on what
you hope the weather will be.
• Pre-plan alternative courses of
action.
• Leave a margin for error, or the
unexpected - carry ample fuel
reserves.
WHU AltBORNE
• Keep an eye on the sky.
• Monitor weather broadcasts and
ask for updates.
• Don't push your limits.
• Make your turnback/land
decision early.
�
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�Contents
3
6
Hand portable fire extinguishers
Ultra-lights aren't easy
The handling characteristics of many ultra-lights are
substantially different to the GA range; GA experience
is not necessarily completely transferable, and
overconfidence arising from that experience can be
gravely misplaced.
8
Hypothermia
This term is used to describe the condition which
occurs when the body's core temperature falls below
35°C (95°F), a mere 2°C below the temperature usually
regarded as normal. Hypothermia is one of the maj o'r
dangers facing survivors of a ditching in the seas off
Austral ia's central and southern coasts .
Hand portable ·fire extinguishers
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to
Australian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Australian civil aviation.
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or wishing to notify a change of address should write to:
The Publications Distribution Officer
Department of Aviation
P.O. Box 18390, Melbourne, Vic. 3001
12 On remaining current
A glider pi lot operated the tow cable release rather than
the airbrake release to control his final approach. Lack
of experience and currency prevented him from
recognising the error.
13
Faulty fuel management
A number of important fuel management lessons
emerge from an accident in which a C182Q made a
forced landing on a golf course.
16
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.G. T. 2601
Subscriptions may also be lodged at AGPS Bookshops in the
capital cities.
Human factors
(1) Frustration. A C206 was destroyed as the result of a
series of mistakes made by the pilot following the
frustration of a delayed departure.
(2) Impulsive action. A euphoric pilot put his aircraft
in to a descent so that he could make a low pass over
the smooth waters of a lake. During the pull-up the
aircraft struck a power line; the pilot subsequently
expressed the wish that his experience be used to warn
others.
18
Propeller safety
20
No-radio near-miss
A GA aircraft flew into restricted airspace and through
the centre of a display loop by five military jets. (Reader
contribution.)
23
Aviation Safety Digest is also available on subscription from
the Australian Government Publishing Service. Inquiries and
notifications of change of address should be directed to:
Photographic competition
COVER
Sun set from a Department of Aviation
Gulfstream Commander 6958 (A IS photograph.)
Reader contributions and correspondence on articles should
be addressed to:
The Director
Bureau of Air Safety Investigation
P.O. Box 367
Canberra City, A.G. T. 2601
© Commonwealth of Australia 1985
ISSN 0045-1207
R84!836 Cat. No. 84 2450 8
Can you remember from the last time you flew a light
aircraft:
• What kin d of hand portable fire extinguisher it had
(e .g. Halon , CO:z, dry powder, water based)?
• W here the ext ingu isher was stowed?
• H ow lo r elease it q uickly from its stowage area in an
eme1·gency?
• H ow to operate the extingu isher?
• W hether a ny o pera tional restrict ions a pplied to the
type of cxtingui sha n t?
Indeed, can you remember whether your a ircraft even
had a n extinguisher ?
ff you arc un a ble to answer all of those questions,
then you r safe ty preparation is not as good as it shou ld
be.
Carriage of extinguishers
Printed by Ambassador Press Pty. Ltd.
51 Good Street, Granville, N.S. W. 2142.
T here are mandatory requirements for the carriage of
hand portable fire exti ngu ishers in aircr'aft of the
following ca tego ries:
• all aeroplanes wi th a takeoff weight above 5700 kg
• ch a rt er and R egular P ublic Transport (RPT)
aerop lanes with a max imum takcoff weight of
5 700 kg and below
·
• all he licopters with a maximum weight above
2750 kg
From th is it follows that it is not mandatory to carry
a ha nd portable ext in guisher in fixed-wing GA aircraft
of less than 5 700 kg e ngaged in operations other than
R PT or Charter: in other words, the majo rity of GA
nights in Austra li a can be conducted without an
extinguisher.
I t is, however, clearl y in the interests of safety to
have access to fire-fight ing equipment, and man y
a ircraft owners wisely take the preca ution of fitting a
portable ex tingui sher in their aeroplane, regardless of
the class o f operation for which it is used. The
D epartmen t of Av ia tio n stron gly endorses this practice.
Fitting an extinguishe1- is, of course, o nly the first
2 I Aviation Safety Digest 124
step in helping to protect life and property, as the
following acc:iden t summary indicates .
A light twin was cruising at 7500 feet when the pilot
became aware of a fire behind the throttle quadrant . A
descen t was commenced immediately and the p ilot began
to run through emergency checks and procedures. The fi re
conti nued to burn . Shortly after st arting the descent the
p ilo1 sighted a disused scaled str ip and started an approach
to land there.
With the fire st ill burn in g the pilot took the porta b le tire
extinguisher, in tend ing to discharge it into the throttlt>
quadrant. The extingu isher wou ld not work. By this rime
the p ilot had to concentrate on getting the a ircraft safely
onto the ground , so th e extingu isher was passed to one of
the passengers lo try to get it to operate. In his words:
' l read the in structio ns on the fire ext inguisher - fol lowed
the instructions but nothing happened . I then shook the
extingu is her and heard what [ believed to be a liquid slosh
around in the can is ter.'
l n the event the aircraft was landed and the passengers
safely evacuated . The fire , however, comi nued to burn, th~
eventual outcome of which can he seen in the
accompanyi ng photograph . (over/ea))
While it cannot be sa id tha1 1hc a ircraft would not h;ive
been dcstrnyf'd if a serviceable exti nguisher had been
available , lht> chances a rt' that the prom pt applicat ion of a
suitable cxtinguishant would have arrestf'd the fire be fo re it
became u ncontrollable.
An ext ingu isher that docs not work is just dead we ight
in an aircraft. I t is in an attempt to circum ven t the
kind of occurrence d etai led above that regulat ions exist
regardin g the useful life of, a nd time between ovc1·hauls
for, exti ng uishers .
Service life
Unless approval has been obtained lo the contrary, the
maxim um service life of hand portable fire
ext inguishers is not perm itted to exceed five yea rs taken
from the elate the container was filled . For extingu ishers
which can be overha u led , the m axim um service life
between overha uls again is five years. I n any even t, fire
Aviation Safety Digest 124 I 3
�This light twin was destroyed by fire after the extinguisher was fo und to be unserviceable.
ex tinguishers m ust be per manently retired from service
in accordance w ith the manufacturer's ul timate life
lim ita tions.
For those operators not involved in RPT or Charter
work but who take the sensible precaution of fitting an
exting uisher , their safety initiative may come to naught
if th ey do not a lso ensure that the extinguish er remains
serviceable. Note that an y overhaul on an extinguisher
must be performed in accordance with the
manufacturer 's recommendat ions .
Type and installation of extinguisher
The number, type and location of ext ingu ishers
stipulated for a ircraft on which their carriage is
manda tory can var y. Operators whose aircraft must
carry extinguishers must consult the pertinent Orders .
The m a in purpose of this section of the article is to
draw to. the attention of those owners who do not h ave
to carry exting uishers, but do, the m ain points to be
observed o n selecting a nd fi tting same.
• An extinguisher which is intended for use in the
Flight D eck Compar tment must not contain a dry
powder or wate r based extinguishant . Clearly, this
regulation would affect most GA aircraft.
• Extinguishers must be positioned and installed so
th at they a re readily a ccessible a nd their availability
clearly evide nt to anyone who may be requi red to
u se them.
• Ext inguishers must be located in a n environm.e n t
a nd mounted in an a ttitude which complies with the
manufacturer's recommendations.
• They must not be mounted in positions which could
lead to accide ntal d ischarge or restrict access to other
eq uipment.
• The extinguisher must be mounted in a bracke t from
which it is readily detachable.
4 I Aviation Safety Digest 124
Comparative analysis of extinguishants
Some interesting data emerged from a comparison of
aircraft fire extinguishants r eported in the Septem ber
1983 issue of the U.S. magazine A viation Consumer. The
Digest wishes to acknowledge Aviation Consumer's kind
permission to refer to that data.
D ry powder. Dry powder extinguishers have often
been favoured because they are light and cheap . While
they are norm ally effective on open blazes they do not
penetrate well in to deep , smoulder in g fires. Fu rth er,
dry powders which eventually are melted by exposure
to heat a re dange rously cor rosive to bare alum inium ,
electrical equ ipment and engines. Several years ago the
(U.S.A.) Nat ional Business Ai rcraft Association
main tenance bulletin poin ted o ut that two aircraft
en gine fa ilures had been caused by ingestion of dry
chemicals d uri ng attempts to extinguish intake man ifold
fires because the ch emical residue fo rmed a sticky
shellac-like substance on the intake valve stems, causing
them to seize .
There is also an instance on record of a dry powder
extinguisher being accidentally dischar ged in a light
aircraft cabin in fl ight, and creating in stant IFR
conditions inside the cockpit. The pilots reported
conditions of ' blinding clouds of white powder
obscuring everything, a nd the aircraft slowly sliding
in to a spiral' .
Carbon dioxide. C arbon d ioxide works as a n
extinguishant by smothering a fire and displacing all
the oxygen. A drawback here is that , u nder certain
circumstan ces , it may have the same smothering effect
on the pilot. Another problem with C02 is that the gas
exits extinguishers at a temperature of about mi nus
45 °C, which gives it the potent ial to cause a blind ing
condensation fog, or thermal shock damage to any hot
electrical or avionics systems exposed to the subfreezing blast.
Finally, while COz works against most types of fires,
it is no more effective in penetrating a smouldering,
imbedded fire th an is dry powder. (Incidentally, for
these imbedded fires, such as one in a seat, plain
ordinary water works better than anything else.)
Halon. The use of Halon hand portable fire
extinguishers is recommended by the D epartment of
Aviation. T wo types of H alon are readily available and
w idely used: H alon 12 11 (BCF) and Halon 1301. Unlike
COz, the H alon liquefied gases do not smother a fire;
instead, they inh ibit the chemical flame chain reactions
to terminate the com bustion process.
H alon 12 11 (brom ochlorodifluoromethane) is highly
effective and m ost read ily available in hand-held
equipment suitable for use in light aircraft. Since Halon
1211 i's in a liqu id state below minus 5 °C and
discha rges from most extinguishers at temperatures
varying from minus 10 to minus 5 °C, it is discharged
in the fo r m of a fine mist of droplets (about 85 per cent
liquid and 15 per cent gas) and thus has a good throw
distance (i. e., 'squirting' range) of 3 to 5 metres.
1211 's discharge temperature is so much higher than
that of COz that it is far less likely to cause any thermal
shock damage to sensitive avionics and instruments in
an aircraft panel .
Note that extinguishers containing Halon 1211 will
satisfactorily extinguish a Class 'A' (fabric, paper,
wood) fire, as comb ustion is prevented for as long as
the gases remain around the burnt material. H owever,
there is a danger of re-ignition when the gases dissipate
CLASSES OF FIRE
Fires in ordinary combustible
materials, such as wood, cloth, paper, rubber, and
plastics for which the quenching and cooling
effects of quantities of water, or of solutions
containing a large percentage of water, are of prime
importance.
Class B - Fires in flammable liquids, oils,
greases, tars, oil base paints, lacquers, and
flammable gases for which extinguishing agents
having a blanket effect are essential.
Class C - Fires which involve energised
electrical equipment and where the electrical
nonconductivity of the extinguishing media is of
Importance.
Class D - Fires which involve combustible
metals, such as magnesium, titanium, zirconium,
sodium, lithium, and potassium and require
extinguishing agents of the dry powder types,
following special techniques and manufacturer's
recommendations for use because of the possible
chemical reaction between the burning metal and
the extinguishing agent.
Class A -
EXTINGUISHING AGENTS
The following extinguishing agents are
recommended as appropriate for use on the classes
of fires defined above:
Carbon dioxide - Class B or C
Water - Class A
Dry chemicals - Class A, B or C
Halogenated hydrocarbons - Class A, B or C
Specialised dry powder - Class D
because of high residual heat in the combustible
material and the presence of oxygen in the atmosphere.
This possibility can be overcome by following up with
water after a deep seated Class 'A' fire.
Note: Never discharge Halon 1211 onto burning
metal fires .
Halon 1301 (or bromotrifluoromethane) has virtually
the same fire-fighting capability as H alon 1211 but it
has a number of different physical characteristics that
make it more suitable for built-in total flooding systems
than for hand-held extinguishers.
Other advan tages of both Halons are as follows:
• They are electrically non-conductive.
• Unlike dry chemical extinguishants, Halon
evaporates completely and leaves no stains or
residues of an y kind.
• H alon is five times heavier than air, so it tends to
remain concentrated in the target area; although
when it is fully circulated throughout an aircraft
cabin, it will remain in atmospheric suspension and
not settle out to the floor.
Operating considerations. Both types of Halon begin to
break down chemically when exposed to temperatures
above 460 °C, and their decomposition by-products
(primarily hydrogen, fluoride, chloride and bromide)
are both acrid and h ighly toxic. Halon 1211 is about
five times more toxic than Halon 1301 (which is one
reason why the latter is preferred for flooding systems).
The toxicity of H alon is such that inhalation can
make the heart abnormally sensitive to elevated
adrenaline levels (which would certainly be present
during an aircraft fire) - a phenomenon known as
cardiac sensitisation. T his can result in heart
arrhythmia and possible death. H owever, these effects
are rapidly and completely reversible upon removal
from exposure, or a good ventilation of the aircraft
cabin.
Here, it is significant to note that tests cond ucted by
the American FAA indicate that the use of Halon in
small aircraft in flight is unlikely to be dangerous; the
reason being that light a ircraft cabins generally are so
well ventilated that the Halon discharged from a
portable extinguisher can never reach high enough
levels of concentration to become toxic. In a test using
a Cessna 210, the FAA found that its vent ilation rate
prevented the Halon dosage released from reaching
more than about one-quarter of the level that might be
toxic.
As is the case with any extinguisher, the imperative
with Halon is to extinguish any fire as rapidly as
possible in order to:
• achieve the primary objective, and
• minimise toxicity.
Summary
Several most important conclusions arise from this
information. Aircraft fires can happen to any pilot, and
will happen to some pilots reading this article. I t will be
too late if you wait u ntil after the sudden conflagration
occurs to start desperately searching for a fire
extingu isher that may not work, or may not even be
there. Make sure that the odds are on your side by
having access to a sui table, serviceable hand portable
fire extinguisher. Also , carrying a container of water
will add insurance against seat fires •
Aviation Safety Digest 124 I 5
�Ultra-lights aren't easy
The results of several accident investigations completed by the Bureau of Air Safety Investigation
indicate that some pilots - particularly those with experience on General Aviation aircraft believe that flying an ultra-light is relatively easy. This is a mistaken and dangerous notion. The
handling characteristics of many ultra-lights are substantially different to the GA range, including
the most commonly used types such as the C150, C172, PA28 and so on. Ultra-lights tend to have a
narrower performance envelope, far less power to weight, and far more drag. One significant
consequence of this is that their inertia is nothing like that of a GA aircraft; thus, when the throttle
is closed or the engine stops, the loss of airspeed is far more rapid than is the case with a GA
machine. Additionally, when you operate at speeds of around 20 knots, the effects of wind and/or
terrain - even a 5 knot gust or a single tree - can produce alarming control problems for the
unwary.
This is not to suggest that ultra-lights are inherently dangerous. Rather, the point is that training
must be thorough; GA experience is not necessarily completely transferable, and overconfidence
arising from that experience can be gravely misplaced. All of those factors - as well as other
important safety lessons - were evident in a serious accident involving a Skycraft Scout Mark Ill.
D iscuss in g the b ri ef fl ight with the owner - who had
been d isturbed when he saw the aircraft unexpectedly
take off - the pilot commented that the engine had
see med to m iss when he reduced power on reaching
20-30 feet . T he owner rep lied that this was probab ly
caused by the th rottle being retarded too quick ly. Th is
ex planat ion was accepted. The owner also mentioned
tha t the aircraft sho ul d always have its engine at full
power wh en cli m b ing .
No fu rthe r fami lia risation taxiing or flying was
cond ucted : th e sale was concluded and the pilot
departed wi th his new aircraft in its tra iler.
T wo days after buyi ng the Scout the pilot caITieci out
some ro u tine mainten a nce checks . A witness later
rep ortc~cl tha t severnl prob lems were evident during an
engi ne ground run. The engine had been dif'licult to
start , wh ile durin g a fu ll power run there reported ly
had bee n some m isfiri ng and excessivc- vibnHion .
A pparen tly these prnblems had been resolved by
rep lac ing the spark plug and cleaning the contact
breaker poin ts.
The follow ing d ay the p ilot transported the Scout to
his local a erodrom e. He assembled the aircraft,
strapped in , an d started the engine, apparently without
d ifficul ty. H e th en taxied to the intersection of the main
tax iway and gr ass runway, lined up, and took off
towards the west .
W hen the a ircra ft had reached a height of about
100 feet , a left turn was commenced and some
witnesses repo rted hearing a slight power reduction.
T he Sco ut appeared to be flying slowly during the turn
in a nose-high a tt itu de . After it had tu rned through
app roximat ely 200 d egrees it appeared to stall and
entered a steep d ive . It hit the ground about 75 metres
to the sou th of the grass runway, in a paddock which
was heav ily grassed and in wh ich the soil had been
softened by recent rain.
The aircraft was destroyed and the pilot, who was
not wearing a protective helmet, sustained serious
111J UrieS .
Analysis
A tech n ical exa mination of the a ircraft wreckage failed
to reveal evidence of any pre-ex isting mechanical fault
or fa ilure. In conj unction with witness reports and the
on-s ite inves tigation, th is finding made it clear that the
ai rcraft had indeed stalled .
Investigation also led to the conclusion that the pilo t
had made no attempt to recover from the stall. This
was con sidered likely to have stemmed from a number
of fac tors:
• his inexperience o n type
• the a ircraft ' s close proximity to the ground
• the eleme nt of surp rise
The accident
A pilot with a private licence a nd aboul 250 ho urs CA
expe ri ence in tended purchasing a Skycra ft Scout. H e
ha d not flo wn the type, or any other ultra-light ,
previo usly .
Before buy ing Lhe a ircraft the pilo t arranged lo
complete a check flig ht a nd , at the same time,
famili arise himself with the m achi ne . T he norm al
procedure fo r p ilo ts learni ng lo fl y a n ultra-lig ht
. con sists, a mo ng othe r th ings, of con d ucting a series of
6 I Aviation Safe ty Digest 124
sho rt ' hops' a long a strip in ord er to become fam ilia r
with t he aircr aft 's han dling characteristics gradually and
safely. The pilot was a lready aware of' th is . Further,
before hi s check sortie, he was advised by the
then-own er to lim it him self in itially to gro und ha nd li ng.
H owever, after only several mi n utes of taxiing du ring which , according to one witness, the pilot d id
not appear to have pa rticularly good control - he took
off, climbed to abo ut 20- 30 feet, reduced power and
la nded immediately .
The fligh t was onl y the pi lot's second on type and he
had not properly acquainted himself with its low speed
handling cha racteristics. Indeed, he had no t even
fam iliarised him self with normal operating procedures:
had he clone so, he would not have reduced engine
power while in t he clim b (as reported by witnesses) at
a bou t the time he en tered the left turn.
As far as stall ing at a very low altitude is concerned,
it is like ly that when the aircraft's nose dropped rapid ly,
the pilot would have experienced a sensation sim ilar to
that which parachutists know a s 'ground rush'. This
wo uld probably result in an instinctive reaction to pull
back on the control column, which in turn would
nullify any inherent longitudinal stability effects
assisting recovery from the dive as speed increased.
(Note that in an ultra-light, the onset of this 'ground
rush' sensation is likel y to be far more rapid than for a
GA aircraft , given the former's particular aerodynamic
and performance characteristics.)
Finally, any inadvertent stall is likely to contain an
element of surprise. In these particular circumstances ,
anything which delayed the commencement of the
correct recovery actions was going to be critical.
General safety lessons
Two other important lessons emerged from this
accident . First, the pilot was not wearing a protective
helmet . D epending on pilot size, there may be
insufficient clearance in this particular aircraft when the
pilot is seated, between the tail boom and a helmeted
head. H owever, discussions with the Scout's
manufacturer elicited the advice that this prob lem can
be easily overcome by the pilot positioning his head
ei ther side of the tai l boom by leaning to the left or
right. Also, regarding safety equipment, the a ircraft
had only a lap seatbelt rather than a full lap/ shoulder
harness .
Second, the pilot was a large man. By definition,
ultra-light aircraft are very small and, clearly, pilot size
may significantly affect aircraft performance . As it
happened, this pilot was heavier than the maximum
weight recommended by the manufacturer. It was
estimated that the effect of thi s would have been to
move the position of the longitudin al centre of gravity
aft, thus reducing s tability.
Comment
Ultra-ligh t fl ying is a growing sport in A ustralia,
offering as it does some of the exh ilaration of stick-andrudder, open cockpit piloting at a reasonable price .
L ike any sport, the odds are you will enjoy it more if
you are good at it . In aviation that means being
thorough and safety conscious in your attitude to all
operational aspects: for pilots and LAMEs, wo1-ds like
'good' and 'expert' are synonymous with 'safe'.
Enthusiasm and safet y awareness are not mutually
exclusive; on the contrary, when they exist in
conjunction they enable you to derive maxim um
enjoyment from your recreation •
Notable quote
Seven steps to safety stagnat ion:
•
•
•
•
•
•
•
It won't work.
It costs too much.
We're doing okay without it.
We're no t read y for that yet .
We tried it once a nd it won't work .
We've never done it that way before .
That 's not my responsibil ity .
Ostrich
A viation Safety Dig est 124 I 7
�Phowgraphy courtesy of National Safety Council of Australia (Victorian Division).
Decompression
Ditching
If aircraft pressuri sation is lost at relatively h igh
a ltitudes (as a guide o nly, say above about 25 OOO feet)
o ne of the conseq uen ces will be a rapid drop in
tem perature. Unless the aircraft is descended to a
lower, warmer tempernturc within a short period (about
2 - 5 m inu tes) damage lo skin and hypothermia can
res ult.
In any circu mstan ces, prolonged operation in a cold
cockpit is likel y to lea d to physiological and, therefore,
performan ce problems.
I n the past decade there have been a number of wcl lpublicised aircraft d itchings in the Australian region . It
may surprise some readers to learn that the average
rate of ditchings during that period has been abou t fo u r
a year and, while a number of those have be'en into
inland lakes, dams and the like, many of the othc1·s
have bcC'n into the general ly far less hospitable oceans.
A d itch ing involves num erous hazards, no t the least
of which is that of surv iving once the aircraft is safely
in the water. I n the seas off Aus tralia from about the
cen tral eastern to the central western coastal
extremities, perhaps the key factor for much of the year
is that of retain ing suf1icien t body heat to stay alive. In
this con text, it is significan t to note, first, that a water
tcmpcrnture of about 20 °C seems to be the demarcation
point between 'safe' and 'dangerous' water
temperatures, and, second, tha t average sea
temperatures off Australia's central/southern coasts are
about 15 - 20°C in summer and 10 - 15°C in winter.
There is little doubt that in a number of Australian
ditchings the touchdown itself was survivable, but the
failure to carry life-saving equipment, or ignorance of
life-saving procedures, subsequcn~ly contributed to
death.
T hus, before addressing the subject of body
temperature loss after ditch ing in detail, it is worthwhile
emphasising - yet again - the absolute im portance of
thorou gh preflight preparation. Here, in addition to the
normal requirements, special attention would have to
be paid to such items as:
• night planning - fuel, accurate reportin g points
and times, submission of a detailed flight plan
• survival equipment (cg, ELT, raft, life jackets, an tiexposure sui ts, rations, etc)
• aircraft glide performance
• diversions, equi-time po ints and so on
• knowledge of survival techniques
On land
The human body has well-defined limits for its
optimum performance. In the way that an aircraft has a
' performance envelope' so too the human body has an
envelope in which it operates well. Take the human
body out of this envelope and it complains, usually with
a sensation of pain; then if no notice is taken of the
warning it begins to fail.
One of the important elements of human
performance is the control of body temperature,
particularly of the inner core of vital organs. The brain
especially will only perform satisfactorily within a
narrow band of temperatures. The control of
temperature is complex but the heat produced by bodily
activity (metabolism) must be balanced by heat loss
from the body to maintain an equilibrium. This may be
expressed in the form of a simple equation:
Heat produced
Heat loss
(Metabolism)
(Radiation + Convection +
Conduction + Evaporation)
We sh ould all be familiar with the processes of heat
transfer from our knowledge of physics gained at
school. The modes of heat transfer should therefore be
well known and experienced in our everyday lives. W e
are famili ar with heat loss in cold weather, made worse
if there is a wind or our clothing is wet. We are less
likely, though, to have experienced heat transfer by
conduction . It is possible to transfer heat to our bodies
~rom the environment if the air temperature is high ,
8 I Aviation Safety Digest 124
there is no wind and it is h umid. This heat gain is not
a topic for this article, but in ·some circumstances it
may occur and create major difficulties.
The topic of this article is heat.,loss which leads to a
reduction in the core temperature· ?f the body hypothermia. The term is derived from the Greek hypo
(below or under) and thermos (warm). This term is used
to describe the conqition which occurs when the body's
core temperature falls below 35 °C (95 °F), a mere 2 °C
below the temperature usually regarded as ' normal ' . In
its early stages hypothermia can seriously affect
performance , while a severe case can result in death.
There are three main situations in which p ilots are
likely to find themselves exposed to this dangerous
condition:
• loss of aircraft pressurisation (decompression)
• exposure to extreme cond itions on land
• exposure to extreme conditions and/or immersion
after a ditching
In Australia serious body heat loss is most likely to
be associated with immersion , so the major part of this
article is directed towards the problems associa ted with
ditching . At the same time, th e dangers arising from
either prolonged flight at high altitude in a very cold
cockpit or exp osure on land to low temperatures and/or_
a high wind chill factor cannot be discounted.
I t is a wise precaution in much of Australia always lo
have avail able in your aircraft warm p rotect ive
clo thing. Should the unexpected even tuate - as it often
does in aviat ion - such as an unplanned stopover in a
remote area, or an emergency landing, what might
have at first been a pleasant, m ild day may soon
become a fight for survival should you find you rself
faced with a cold night, winds, little shelter, high
terrai n , an d so o n .
Preventi ng hypothermia. If you lind yourself in the
si tuatio n described a bove, the important points to note
a re :
• tr y to find so me shel ter;
• put on extra clothing;
• have something to cat and drink; and
• make a careful assessment of all factors before
comm itting yourself to any course of action.
Symptoms. Someone suffering from hypothermia wil l:
• be cold to touch; a nd
• have a slow pulse accompanied by slow and shallow
b reathing .
Note that elderly and infirm casualties may be
unconscious (the young and old are particularly
suscep tible to hyp otherm ia) .
T he patient may have a p ink face, hands and feet,
wh ich can give a visually deceptive impression of
warm th.
Treatment. T reat as follows:
• Pl ace the casual ty between blankets so that the
tem pera ture can r ise gradually.
• If conscious, give warm sweet drin ks (bod y supplies
of sugar are redu ced with prolonged exposure to
cold).
• Do not use hot water bottles or electric blan kets as
these w ill open up skin vesse ls and take blood from
deeper tissu es, causing collapse .
Note J : R ecovery can be sw ift but if it has not occu rred
with in 15 min utes, or the patien t has collapsed,
he w ill not be able to to warm himself; you
must do it fo r him. You must treat him on the
spot - he may collapse and die if you wait too
long attempting to get to shelter.
2: Al co hol has no place in preventing the onset of
h ypothe rm ia . T he use of alcohol before, during
or after profound exposure to a cold
env iron me nt cannot be dep lored enough .
A lcohol causes the vessels of the skin to dilate
a nd will g ive ri se to a considerable loss of body
heal fro m the core, the very opposite to what is
1-cqui1-ed. Similarly, the inexpert administration
of drugs is likely to exacerbate a pat ient 's
condition .
*
*
The most likely occur re nce of hypothermia is during
immersion in water which is below 20°C. At water
temperatures below this, heal loss outstrips any
conservat io n of heat which the body attempts by way of
compensatory mechanisms. The high thermal
conductivity of water leads to rapid body cooling. In·
turn, the loss of heat from the skin and extremities
(body shell) produces a heat gradient with the core
which causes a transfer of heat to the shell and thus to
the environment. Movement of water past the body will
increase the heat loss convection effect, though the
relative movement of water to a lloating body is likely
to be small. T he body attempts to conserve heat by
constricting blood vessels in the skin and subcutaneous
fat which then become layers of insula tion . In addition ,
the body endeavours to produce more heat by inducing
shivering, which at its maximum raises heat production
five-fold above the normal resting level. As the core
temperature falls below 35 °C mental confusion occurs,
and manual dexterity and st1-ength wane to a level
where a survivor will be unable to clutch and hold a
line. A further fall in core temperature sees the
shivering replaced by stiffness and consciou sness
reduces. Life expectancy diminishes rapidly with the
onset of unconsciousness . It is imperative that perso ns
Aviation Safety Digest 124 I 9
�in th e water are recovered as soon as poss ible , a t least
in to a raft if not lo land. Figure 1 illustrates the effects
of reducing body tempe rature .
How long can a pe rson survive in water? The answer
to this question is surrou nded by man y 'ifs' and ' buts ' .
Variations of many factors alte r the chances of survival,
so it is pertinent to discuss some of these factors.
OF
oc
98·6
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
95
86
77
-
"Normal" body temperature
_
Sensation of cold, shivering
-Confusion, disorient at ion,
manual dexterity impaired
-
Introversion, amnesia
_S hive ring replaced by
muscle rigidity
j
Semi-conscious
_
_
Unconscious
Muscle rigidity ceases
-Death
Fig. 1. Effects of drop in body temperature
Water temperature
The temperature of the water in which a pe rson is
immersed is obvio usly of prime importance. The lower
the temperature , the greater the risk. As already
su ggested , 20 °C (68 °F) appea rs to be the borderline
be tween 'safe ' and ' d an gerou s' water tempera ture , but
only if prolo nged for a ma tter of days instead of h ours.
Note again t hat the average sea level tempera tu re in
Bass Stra it is 20 °C or less the year round , and that
similar condit ion s will prevail over the entire Australian
coa st from the south-east to the so uth -west for
significant pe riods of rh'~ yea r.
Duration of imm ersion
Related intimately with water temperature is the
duration of exposure . A short time-exposure to very
cold water m ay be tolerated , whereas a longer period of
time in warmer water may be fa tal. The relatio nsh ip
between duration of exp osure and water tempe rature is
well shown in Figu re 2. The Jines of the gra ph are
d rawn for 'average ' persons wi tho ut an anti-exp osure
suit.
Fat
S ubcu taneou s fat is an excellen t insula tor against heat
loss a nd 'fatties' a re much better a ble to manage cold
10 I Aviation Safety Digest 124
water immersion than 'skinn ics . ' S urviva l rates may b e
imp roved b y u p to six tee n tim es for the ver y fat pe rson
over the very th in . Small child ren , beca use of their
relatively large skin area, cool mor e rapidly th a n adults.
Male adults cool mo re r apidly than fem a les of similar
size because of genera ll y havin g thinner fa t layers . The
chivalrous call of ' W omen and child ren first ' should
perha ps be reconsidered and replaced by ' Child re n a nd
men first'! (Howeve r , th e improved survival rate of
' fatties' should not be an excuse for over-ind ulgence in
food and dr ink to produce a fat ty layer, as there are
more disadvantages to fat ness th an there are benefi ts.)
Water experience
Persons who spend a good deal of time in the water,
especially the sea, and feel ' at home' in water a re
usually a ble to su rvive better. Experienced sw im mers
develop layer s of fa t and some level of adapta tion to
cold and are more likely to su rvive . T hey are a lso less
likely to panic and thereby lose the ir life by d rowning
from inappropriate actio ns .
Exercise
Although exerc ise such as swi m m ing will produce hea t
and there fore appear to be an answer lo L!educing core
te mperature , it ha s an un fo r tuna te side effect. The
incre ased acti vi ty causes the blood su pply to the shell
(skin) to open up an d transfe r heat to the surroun ding
water very rapidly , causing the core tem perature to
drop even further. Swim m in g should not be unde rtaken
un less you ca n reach land in a ver y few m inu tes.
C lothing
Cloth in g loses much of its insulating prop ert ies wh en it
is wet, thou gh it will decrease the ra re of cooling to
some exten t. T he us ual clothing of crew a nd passengers
who m ay have to survive in the waters a rou nd Australia
will probably not ad d significantly to their survival
times. The o nl y substant ial improvemen t comes fro m
using an anti-exposure su it.
Prevention of immersion -induced hypothermia
W hen an ind ivid ua l is immersed in cold water there is
little th at can be do ne to stop the core temperature
dropping , b ut step s can be taken to slow down the heat
loss.
Flotation
T he use of a life jacket will enhance su rvival as it will
no t on ly ass is t in keeping the survivor on the su r face
and a id aga inst dro wning, but because the su n 1 ivor
need no t tread water , he can preserve his ene rgy
rese rves. The use of a notation device therefore
significa ntly e nh a nces su rvival.
Clo thing
W hilst clo thing loses a lot o f its insulati ng properties
wh en wet, layers of clot hing will ass ist in trapping water
close to t he bod y which will warm to provide some
insul a tion . Q ui re obviously the use of an ant i-exposu re
su it by cre w a nd passengers o n a ll over-water fl ights is
no r practi cal. There is com mercially availab le though , a
garmen t wh ich w ill provide notation an d protection (O
h igh h eat-loss a rea s for those persons who re gularly ny
light a ircra ft over wa ter , a nd wh ich is claimed by its
manu factu re rs to increase sur vival time fou r-fol d .
I n-water techniques
It has been established that the m a in areas of heal loss
from the bod y are the head, n eck , axillae (armpits),
sides of the chest and the groin. Any techn ique which
p revents water cond ucti ng heat away from these areas
is therefore most helpful. A solitary su rvivor can help
himsel f by ta ki ng u p the ' H e at Escape L essen ing
Posture' (HELP) as illustrated in Figure 3 . Flotation
gear will keep the h ead above wa ter, fold ing the arms
round the chest will protect the axillae and chest, a nd
fold ing up the legs covers the gr oin . If a few su rvivo rs
are presen t in the w a ter , they can h u ddle together fo r
m utual protection (Figure 4). T he techniqu es of H ELP
a nd huddlin g m ay well increase survival times by
50 per cen t , a sign ifican t im provemen t .
Alcoh ol
Atten tio n must be d rawn again to the sect ion a bove
addressing the d a nger s inh eren t in admini ster ing
alco hol or drugs to h ypothermia victim s.
• P repa re properl y for your water crossing
- a ircraft equ ipmen t mainten an ce
- a ircraft flight plann ing
• Waler su rvival
- flotation eq uipment
- life jacket
- life ra ft
- rem ain still
• Single - H ELP postu re
• Multiple - h uddle together
• Above all D ON'T PAN IC - CONSER VF. YOUR
5
99% Lethal
g4
J::.
~
Q)
.5 3
Marginal
50% Lethal
I-
c
·~...
Pre-fligh t pla nning
A s is the case without exceptio n, the key to safe
operations is preflight planning. P roper ma inten ance
and prepa ration of the aircraft is a prerequisite for any
flight. Fo r over-water flights, it is also essential ~at any
survival gear such as life r afts, life jackets and signal
dev ices are no t only serv iceable, but readily accessible .
L ife j ackets should preferably be worn . Finally , if there
is any possib ility of flight over water, then a flight plan
should be filed a nd repor ting posit ions and times
adhered to so that in the unfortu nate eve nt of a
d itchin g, the search and rescue facilit ies m ay swing in to
action at the earl iest possible mom enL
Summary
6
U>
...
Fig. 4. 'Huddle '
ENERGY
2
e
QI
~1
Safe
0
0
4
8
12
16
20
Water Temperature ° C
Fig. 2. Effect of water temperature on survival prosp ects.
Fig. 3. Heat Escape Lessening Posture (HELP)
A viation Safety Digest 124 I 11
�On remaining current
A glider pilo t was re turning to land afte r a pe riod of
general handling practice. When esta blished on the
landing glide path , he o perated wh a t he thou ght was
the dive brake ha nd le to extend the brakes to con trol
his final approach . However , the glide r' s d esce nt profil e
did not chan ge w hich m eant that it qui ckly b egan to
ove rsh oot th e strip.
Realising that h e was going to go beyo nd the strip ,
the pilot decided to complete an ou tla nding in an
ad jo ining paddock whi ch a ppeared b oth ad equa te in
si.:c a nd free from obstruc tions . Ye t again the glide r
floated, to the e x te n t tha t it al so over shot the selected
o utla ndin g area .
By thi s sta ge the pilot had little control ove r where he
was going to tou c h d o wn. In the e vent th e glider settled
o n to the down slope of a m inor undulation , traversed a
patch of soft we t ground a nd then hit rising gro und. I t
was substantially d a m aged while the pilo t susta ined
mmor 111Jury.
This pilot had in the o rde r of 160 hours experience,
90 of w hi ch were on powered airc ra ft and 70 on gliders .
Hi s training had suffe red from large time gaps between
fli ghts . His rece nt e xp e rien ce had been pa rtic ularly
sparse:
• 4 hours in the p ast 3 months
• 1 hour in the curre nt month
Because of this, his gliding club had given him a pre solo check prio r to the flight durin g w hich the a ccident
occurred . Follow in g that check fli ght the pilot wa s told
by his instruc tor that he needed to pay more atte ntion
to airspeed control .
During the approach on h is solo fligh t , the p ilot was
co n scious of thi s d e briefing and it seem s probable that
h e concentrated o n the airsp eed indicator to the
detriment of o ther necessary action s . Whe n he reached
the stage at which it was n ecessary to exte nd the
a irbrakes, he inad ver tently pulled the towcable release
lever rather than th e a irbrake lever (see photograph).
Despite the fac t th at he overshot no t on ly the strip
but also his selected outlanding area, the pilot was
un a ble to make the logical connection be twee n his
airc r aft 's excess per formance and the failure of the
a ir bra kes to extend . This was directly linked to hi s
limi ted rece n t exp e ri en ce. Among the 1·elevant factors
ide ntifi ed a s contributing to the accident were the
fo llowing:
• pi lo t inexperie nced on type
• pilot not in curre nt flying practice
Comment
R egardless of w hethe r o ne is fl y ing a jumbo or a
minimum a irc raft , a ce rta in frequency o f op e ra tio n is
essentia l to retain p rofi cie ncy . The ideal sys tem is the
fi xed and closely super vised trainin g regimen e nj oyed
by RPT aircre w . Clea rl y, ho wever, su ch a regim e n is
impracticabl e for those who fl y for recreation or ,
indeed , in some cases, on p ri vate business .
No a mount of regula tion will ever ensure pilo t
curre ncy. Superv iso rs within s uch organisation s as
fl ying clubs, schoo ls a nd compa ni es bear a la r ge
r esponsibili ty for en surin g th a t those who u se o r hire
their airc ra ft are qua lified , compe tent and c urrent.
As is so often the case in aviation it is , though , in the
fin a l ana lys is, the individua l's decision whether he or
s he is ' up to it ' . It is n o t just a matter of getting o ff the
g round a nd getting back o n aga in . We must be certain
w ithin ou rselves that whe n the need arises we h ave the
a bility, bo th in terms of familiarity with our aircra ft
a nd overall aeronautical knowledge , to analyse and deal
wi th unexpected events .
If you do not have that certainty, then it is time to
ta ke the in itiative yourself and arrange for some
consolida ted dual training.
As a last thought , a nd a ppreciating th a t recreational
fl ying can b e a n expensive business, time spe n t sitting
in a co ckpit on the ground with the Pilot 's H a ndbook,
famili a rising - or rcfamilia risin g - yourself with
controls , systems and checkli st sequen ces is rarely
wasted •
Aircraft accident reports
FIRST QUARTER 1985
The fol lowing information has been extracted from accident data files maintai ned by the Bureau of
Ai r Safety Investigation. The intent of publishing these reports is to make available information on
Australi an aircraft acc idents from wh ich the reader can gain an awareness of the circumstances and
condit ions w hich led to t he occ urrence.
At the time of pu bli cation many of t he accidents are st il l under invest igation and the information
contained in those reports must be considered as pre liminary in nature and possibly subject to
amendment when the investigat ion is finalised .
Readers should note that the information is provided to promote aviation safety - in no case is it
intended to imp ly blame or liability .
Note 1: All dates and t imes are local
Note 2: Injury classif ication abbreviations
C =Crew
P = Passengers
0 =Ot hers
N =N il
F = Fatal
S = Seri ous
M =M inor
e.g. C1S, P2M means 1 crew mem ber rece ived serious inju ry and 2 passengers rece ived minor
inj u ries .
PRELIMINARY REPORTS (The following accidents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
04 Oct
Cessna 150M VH·TDX
Instructional-solo (supervised)
C1 N
1345
Berwick, Vic.
Berwick, Vic./Berwick, Vic.
8431029
Earlier in the day the pilot had undergone a dual check and was authorised to condu c t the same operation sol o. After some time
in the training area he returned for a landing in light crosswind conditions. The aircraft landed heavily nos ewheel first and
bounced several times before the nosegear collapsed rearwards. The aircraft slid to a halt on its nose, 101 metres from the initial
touc hdown point.
07 Oct
Cessna 182M VH-EGZ
Non-commercial-pleasure
C1N , P3N
1730
Flinders Is , Tas
Canberra, ACT/Flinders Is , Tas
8431030
The initial touchdown was in a flat attitude and the aircraft bounced. The second touchdown was o n the nosewheel and the
propeller struck the ground. After the aircraft bounced again the pilot carried out a go-around, during which he noticed about 75
millimetres free travel in the elevators. A safe landing was made and an inspection revealed damage to the firewall , whic h had
moved the elevator control cable pulleys rearwards and allowed the cables to slacken.
12 Oct
Piper PA25-235 VH -CCS
Aerial agriculture
C1N
Blayney, NSW 15 SW
Clay River Hill Stn/Clay River Hill Sin
1200
8421053
During spraying operations the engine suffered a partia l power loss. The pilot initiated dumping of the hopper load but was
unable to prevent the aircraft from striking the ground heavily. The landing gear col lapsed and the aircraft slid for about 50 metres
before coming to rest.
Non -commercial-business
C1N, P3N
Beech E33 VH-ENU
12 Oct
1135
Emerald, Old.
Emerald, Old./Mackay, Old.
8411044
After takeoff the pilot noticed that the airspeed indicator was fluctuating between 35 and 60 knots irrespective of the a ircraft's
actual speed. He elected to land again but, with his attention direc ted towards the faulty airspeed indicator, he forg ot to lower the
landing gear prior to touchdown .
Pilot operated the tow cable release
lever (A) instead of the airbrake
deployment lever (B).
Glasflugel Mosquito VH·GKN Air show/air racing/air trials
13 Oct
C1F,01M
1334
Dalby, Old. 35 NW
Jondaryan , Old./Jondaryan , Old.
8411045
Several gliders were thermalling in one area during a cross-country flight. VH-IZE departed for the next thermal and the pilot,
having determined that he was clear of other aircraft, began a left turn in the thermal. He then heard a loud ba ng and the glider
pitched s tee ply down, however he was able to parachute to the ground. The left wing of VH-IZE. had severed the fuselage of a
s econd glid e r, VH-GKN , and the tail wheel area had s truck the upper right wing and cockpit. The pilot of VH·GKN had been thrown
from his s ea t but did not operate hi s parachute.
13 Oct
Glaser-Dirk DG 202 VH·IZE Air show/air racing/air trials
C1M, 01F
Jondaryan , Old./Jondaryan , Old.
1334
Dal by, Old. 35 NW
841 1045
Several gliders were thermal ling in one area during a cross-country flight. VH·IZE departed for the next thermal and the pilot ,
having determined that he was clear of other aircraft , began a left turn in the thermal. He then heard a loud bang and the glider
pitched steeply down , however he was able to parachute to the ground. The lef t wing of VH·IZE had severed the fuselage o f a
second glider, VH-GKN , and the tail wheel area had struck the upper right wing and cockpit. The pilot of VH-GKN had been thrown
from his seat but did not operate his parachute.
12 I Aviation Safety Digest 124
Aviation Safety Digest 124 Ii
�PRELIMINARY REPORTS (The foll ow in g acc idents are still under invest igation)
PRELIM INARY REPORTS (The fo ll owing accidents are stil l under invest igation)
Date
Time
Aircraft type & registration
Locat ion
Kind of flying
Departure point/Destination
Injuries
Record number
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure poin t/Destina tion
Injuries
Record number
13 Oc t
1046
Piper PA36-300 VH-FET
Finley, NSW 18 N E
Aerial agricultu re
Finley, NSW 18 NE/AG Strip
C1N
8421054
05 Nov
1345
Cessna T303 VH-OBH
Perron Place, WA
Non -commercial - business
Jurien Bay, WA/Perron Place, WA
C1N, P3N
8451031
During the t akeoff roll the pi lot noted a loss of ai rcraft performance, but conside red t hat there was insufficient st ri p length
remaining to safely stop the aircraft. Shortly after becoming airborne the tail assem bly struck the wooden top raili ng of a bridge.
The left wing tip struck a dead tree 65 metres fu rt her on , the aircraf t slewed to the left, to uc hed down and came to rest with the
engine and landing gear torn from the fuselage.
14 Oct
1530
Schemp Ci rrus
Ballan, Vic. 5S
VH -GOM
Non-commercial-pleasure
Bacchus Marsh , Vic./Bacchus Marsh, Vic.
C1 N
8431031
Fol lowing the loss of thermal activity the pilot elected to land in a paddock where the 5-10 knot wind would produce a right
crosswi nd and downwind compone nt for landing. During the base leg, which was commenced fro m a low height, the pilot
realised that his groundspeed was high. The turn to finals was conducted at 60 knots indicated airspeed and up to 45 degrees of
bank to avoid overshooting the final path. Dive brake was applied during the turn to increase the glider's descent angle but the
glider entered a spin. A recove ry was made but the glider collided with trees .
C1N
8431033
Non-commercial-pleasure
19 Oct
Piper PA28-140 VH- PXU
Turrill, Vic./Turriff, Vic .
1600
Speed, Vic. 4 SE
The pilot intended landing in a paddock to inspect the results of recent spraying. He was aware of a power line well beyond the
intended landing area. Sheep obstructed all of the paddock but the pilot hesitated in going round. Havi ng tempora rily forgotten
about the power line, he then saw it too late to climb over and the top of the fin was severed as the ai rcraft was fl own under the
wi re. The impact jammed the rudder, however, the pilot was able to carry out a safe landing in t he adjoining paddoc k.
Non-commercial - pleasure
C1N , P1N
Piper PA28-181 VH-SVQ
Gympie, NSW/Glen Innes, NSW
8421055
Glen Innes 6 NE
The aircraft departed with a planned fuel endurance of 170 min u tes, and an expected fligh t t ime of 116 min utes. About 110
minutes af ter take-off the engine lost power and the pilot was forced to land on unsu itable terrain. The airc raft sustained damage
to the wings , landing gear an d rear fuselage as it ran through two fences and came t o rest after striking several trees. Initial
inspec ti on revealed that the spring loaded fuel drain cock tor the righ t tank was in the open position.
20 Oct
1652
23 Oct
Be ll 47G5A VH-BHQ
Aerial mustering
C1M, P1M
8411046
Miranda Downs, Qld./Miranda Downs, Qld .
0900
Miranda Downs, Qld.
The helicopter was hovering at about 100 feet AGL when the engine stopped . A heavy landing followed. The pilot reported that he
knew t he aircraft normally had an endurance of 220 minutes. On this fl ight he had been operating for 210 minutes, the task was
almost completed and the refuelling point was a short distance away. He c ontinued for a short time with the fue l gauges
indicating empty i n order to complete the task.
23 Oc t
Instruc tional-check
C2N
Piper PA34-200T VH -SVM
8431032
Moorabbin, Vic ./Moorabbin , Vic.
1834
Moorabbin, Vic.
Touchdown on a simulated asymmetric landing was reported as firm and with a sl ight bounce. Duri ng the grou nd ro ll t he righ t
wing settled to the runway and the aircraft came to a halt off the side of the runway. The right hand main landing gear leg was
found to have fractured below its pivot point.
C1 F, P4S, P3M
25 Oc t
Beech 65-A80MK2 VH -TGC Charter-passen ger operations
Charlevi l le, Qld./Trinidad, Qld .
8411047
1206
Tri nidad Sin, Qld.
Ju st before touchdown passengers attempted to advise the pilot that the landing gear was up. Simu ltan eously the propellers
made co ntac t with the ground , the pilot rotated the aircraft and applied full power. Before t he aircraft was c lear of t he s trip the
left engine had stopped , and its propeller windmilled during the subsequent flight. Aft er a steep climb to about 150 feet AGL the
aircraf t began to yaw and roll left until ground impact, which was mainly on the nose and the left engine.
27 Oc t
Bell 206-B VH -AKY
Non-commerc ial -aerial ambulance
C1S, P2F, P1S
8421056
Wi lton , NSW/RNS Hospital, N SW
0213
Trinidad Stn, Qld .
The helicop ter was being used to transport a critically injured road accident victim to a hospital with the necessary specialist
facil i ties. Weather conditions in the Sydney Control Zone were unsuitable for night VMC operations and the pilot dec lared a
merc y flight . Shortly after the pilot reported that he would hold in the area because of cloud, the helicopter crashed into a tidal
embankment.
28 Oct
1806
Piper PA32-300
Darwin, NT
VH-ISB
Non-commerc ial -pleasure
Kununurra, WA/Darwin, NT
C1 N, P5N
8441024
The approach was made with full f lap ex tended at an indicated airspeed of between 75 and 80 knots. As t he pi lot c losed the
throttle in preparat ion for landing , the handle of t he throttle lever came off in her hand. The aircraft struck the runway heavi ly and
bounced several times, collapsing the nose gear leg .
A normal fu ll flap approach was mad e into a 25 to 30 knot sou th-westerly wind . The pilot stated t hat when he attempted to flare
the aircraft he was unable to reduce the rate of descent and the aircraft lan ded heavily.
09 Nov
1630
Cessna A188B-A1
Arubial Lagoon
VH-IEQ
Ac t ivit ies associated with aerial agricu lture
Arub ial Lagoon/Dalby, Qld .
C1N, 01S, 01 M
8411050
The pilot commenced the take-off run wh ile a vehicle was being driven along the left side of the strip. He stated that just after
becoming ai rborne, he had been d istracted by some movement to his left. As he looked to the front again, the left main wheel of
the aircraft struck a drum on the veh icle and then the vehicle cabin. The aircraft was subseq uently landed at the pilot's base strip.
10 Nov
1630
Beec h 77 VH-HBJ
Archertield, Qld .
Inst ructional - so lo (su pervised)
Archerfield, Qld./Archerfield, Qld.
C1N
8411051
After complet ing a dual in struct ion period of crosswind takeoffs and landings the pi lot prepared for solo exerci ses in the tra ining
area. At abou t 45 knots during the takeoff rol l the aircraft unexpectedly became airborne. The pilot had been correct ing for t he left
crosswi nd and when the ai rcraft touched down again it s heading altered sharp ly to the left. Attempts to regain control were
unsuccessful and the pil ot abandoned the takeoff. Damage to t he nosegear was sustained when the airc raft entered a d itch
before coming to rest off th e side of the stri p.
10 Nov
0930
De Hav C2 VH- IDH
Barham Sin, NSW 20N
Aerial agriculture
Barham, NSW 20N/Barham, NSW 20N
C1M
8421062
At a height of approximately 50 feet after takeoff the engine suddenly lost all p ower. The pilo t was able to glide the ai rcraft over
several drainage banks, two fences and an irrigation canal but a high rate of descent developed and the aircraft landed heavily
and overtu rned . Fire broke out and the central sect ion of the f uselage was burnt out.
11 Nov
1156
Cessna U206-F VH-EKJ
Kudgee Stn, NSW
Non-commercial -bus iness
Essendon, Vic./Broken Hi ll, NSW
C1N , P1 N
8441025
The pi lot noticed a low oil pressure read ing and decided to land at a strip he had j ust overflown. As he turned t he aircraft toward
the strip the engine began to vibrate and backf ire and it was shut down. The aircraft touched down 150 metres short of the strip
boundary fence. After runn ing th rough th is fence the aircraft cont inued for a further 280 metres before coming to rest on t he
strip. Init ial inspection revealed that the engine crankcase had been punctu red by a connect ing rod .
12 Nov
1700
Hughes 269-C VH -PSU
North Star, NSW
Non-commercial - pleasure
North Star, NSW/Rocky Springs, NSW
C1N , P1N
8421063
At a heigh t of about 20 feet af ter take-oft the engine sudden ly los t al l power. The pil ot attempted to land straight ahead in a
sorghum f ield, but on touchdown the helicopter yawed and rol led onto its right side.
14 Nov
Transav PL 12 VH-IVH
Non -commerc ial - business
C1N
Andamooka, SA 16E
Le igh Creek, SA/Coober Pedy, SA
1445
8441026
Th e ai rcraft was bei ng flown in company wit h a helicopter. While en route the pi lots had been requested to check the surface of
Lake Torrens tor suitab i lity for fut ure operations. Th e helicopter was landed on a sect ion o f the lake which was assessed as
su itable for the fixed w ing aircraft. The pilot of t hat aircraft also assessed the area as suitable and a landing was made at a
touchdown speed of 40 knots. Short ly after the nose wheel contacted the surface it began to sink i n the soft ground and the
aircraft overt urned.
Roc kwel l S2R VH-WBW
Aerial agriculture
15 Nov
C1N
Moree, NSW 63 NE
Croppa C reek, NSW/Croppa Creek, NSW
0805
8421064
During spraying operat ions the en gine began to run very rough ly and lost a cons iderable amount of power. The pilot cons idered
that insufficient power remained to perm it him to d ivert to a suitab le land ing area and he att empted to land stra ight ahead.
Towards the end of the landin g rol l the aircraft struck a contour bank and the right land ing gear col lapsed.
17 Nov
1025
De Hav DH 84 VH -AQU
Beachport, SA 10E
Ferry
Strathalby n, SA/Portland, Vic.
18 Nov
1500
Piper PA25-236 VH-KKQ
Spring C reek, Qld.
Non-commercial - bus iness
Spri ng Creek , Qld./Atherton, Qld.
C1N , P1M, P1N
8441027
After refuel ling, the pi lot fo und one of the tanks contam inated with water. The f uel was d rained from the tank and clean fuel
added. No contam ination was found in the subsequent check o f the fuel in the tank. The ai rcraft was then washed using a high
pressure water hose. During the fo llow ing f light, the eng i ne began to run rough ly and the pilot decided to carry out a landing in a
paddock. The surface of the paddock was rou gh and the aircraft bounced heavily an d groundlooped, collaps ing the right gear.
C1 N , P2N
8411052
During tax i tor takeoff t he left main gear struck an anth il l and broke at its attachment point.
30 Oct
1015
Beech 58 VH -DTU
Mcintyre 's Field
Charter - passenger ope rations
Archertield , Qld./Mclntyre's Field
C1 N, P3N
8421058
After a normal circu it the aircraft crossed the threshold at 85 knots. The pilot advised that the whee ls locked as soon as braking
was applied. Intermittent brake application had litt le effect in slowing the aircraft and as the pilot considered t hat insu ffic ient
strip remained to permit a go-around he attempted to ground loop the aircraft. It sl id o ff the s ide of the s t rip and co llided w ith a
fence before coming to res t.
C1 N, P1N
Non-com mercial- pl eas ure
04 Nov
Bellanca 8KCAB VH -UOO
8421060
Wallac ia, NSW/Wal lacia, NSW
Wallacia, NSW
1130
Aft er a no rmal approach in cal m wind condi t ions th e aircraft bounced following the init ial touchdown. A nu mber of bounces then
occu rred before th e pilot was abl e to regain contro l of the aircraft. At th is time he assessed that t here was insufficient strip
remai ning to stop the aircraft or to safely go around. A ground loop was attempt ed, during which the right landi ng gear col lapsed.
ii I A viation Sa fety Digest 124
20 Nov
1430
De Hav 82-A VH -PFL
Bankstown, NSW
Non-commercial-practice
Bankstown, NSW/Bankstown , NSW
20 Nov
1100
Cessna 150L VH -DIV
Muttaburra 74N
Non-commercial-aerial appl icat ion /su rvey
Hardington, Qld ./Hard ingtori, Qld.
C1N, P1N
8421065
Th e ai rcraft is fitted with a tai l sk id and was being taxi ed on t he g rass beside the taxiway. The pi lot reported that he was looking
over t he right side of the aircraft when the left wing struck a sign.
C1 N , P1 N
8411053
The pi lot reported that the fl ight was commenced w ith full fuel tanks. An end urance of over 210 minutes was ant icipated with t he
planned fuel f low. The en gine fai led after three hours and the aircraft sustained damage to the nose gear and right wing during
t he ensu ing forced lan ding . The pi lot advised that when he subsequently dipped the fue l tanks the re was no fue l remaining.
Aviation Safety Digest 124 I iii
�PRELIMINARY REPORTS (The following accidents are still under investigation)
PRELIMINARY REPORTS (The following acc idents are sti ll under in ves tigat ion)
Date
Time
Aircraft type & registration
Loca tion
Kind of flying
Departure point/Destination
Injuries
Record number
Britnor 2-A2 1
Wilton, NSW
VH-ISI
Sport and parachuting
(not associated with an airshow)
Wilton, NSW/Wilton, NSW
C1M, P4M, P8N
8421067
16 Dec
1445
17 Dec
1511
At the conclusion of an aerobatic display the pilot performed an inverted circuit , rolling upright as the strip was sighted on final.
On short f inal t he aircraft descended below the desired flight path and the pilot applied power. The aircraft responded but the
rig ht gear leg caught on·a power line 5 met res AGL and 330 metres from the t hresho ld. The aircraft struck the ground in a steep
nose down att it ude and came to rest inverted.
02 Dec
Piper PA28-140 VH-RVL
Non-commercial-pleasure
C1N, P1N
Longwarry, Vic.
Longwarry, Vic./Longwarry, Vic.
8431036
1510
The pilot was to conduct two spot landings from practise forced landing approaches commenced at 2000 feet. On the first
approach an und ershoot developed and power was used to complete the landing. The second approach was high and touchdown
was made about half way down the 730 metre strip. A go-around was initiated but the engine failed to develop significant power.
The takeoff was then abandoned and the aircraft stru ck a dirt bank and drain beyond the end of the strip.
02 Dec
Ayers S2R VH-JBN
Aerial agriculture
C1F
8421071
0305
Mungindi, NSW 2S
" Iolanthe'', NSW/Mungindi, NSW
At t he concl usion of night spraying operations the pilot departed for Mungind i. Witnesses at the town saw the aircraft overflying
at a low height and heading towards the aerodrome, which is about 7 kilomet res from the town. Engine noise was then heard to
cease and sounds of impact followed . The ai rcraft had struck the ground 5 kilometres from the aerodrome, and a post-impact fire
had engulfed the wreckage.
iv I Aviation Safety Digest 124
C1N
8441031
Airparts 24-950 V H-MXD
Forester, Tas 5NE
Aerial agricu lture
Trig Hill Airstrip/Trig Hill Airstrip
C1N
8431037
Cessna A188B-A1 VH- FZD
Kingaroy, Old. 4SE
Instructional-check
Kingaroy , Old./Kingaroy, Old.
C1M
8411056
Glasflugel Kestrel
Pipers Field, NSW
VH -GSY
Non-commercial -pleasure
Pipers Field, NSW/Pipers Field, NSW
C1 M
8421072
Cessna 182-A VH-KLJ
Interview River
Non-commercial-business
Sandy Cape, Tas/lnterview River
C2N
8431039
The pilot decided to land at the strip to check on the welfare of the two mining company employees working in the area. During
the latter stages of the landing roll the nosewheel entered a soft area and dug in, causing the aircraft to overturn.
Non.commercial-pleasure
C1N, P1M
Piper PA 19 VH-ECN
17 Dec
Lismore , NSW
Acherfield , Old./lismore, NSW
8421073
1625
The pilot was making a landing approach in 10 knot crosswind conditions. A fter the first touchdown he experienced difficulty in
maintaining directional control and elected to carry out a go-around. On the subsequent approach the ai rcraft touched down
prematurely and bounced. A go-around was initiated but the aircraft drifted off the side of the strip and struck a fence.
C1S, P2S
8421069
C1N
8441028
Instructional -so lo (supervised)
Monart o, SA/Monarto, SA
Th e pilot was approaching to land at the conclusion of his second flight on the type. Th e approach was normal, however the glider
floated the length of the strip at a height of about 25 feet. At the end of the strip a turn was commenced but after completing
about 90 degrees an incipient spin developed and the glider struck the ground . The pilot subsequently advised that he activated
the cruise flap lever instead of the air brake. The two levers are located side by side in the cockpit.
The aircraft was being used to transport equipment for members of an Aero Cl ub, who were to carry out training at Gou lburn. As
the pilot was undergoing formation flying training, it was decided that he would lead a formation of two aircraft for the flight. A
briefing on the procedures to be followed was carried out. During the flight the pilot of the second aircraft began to suspec t the
accuracy of his aircraft 's airspeed indi cator and requested that it be c hecked agai nst that of the lead aircraft as the aircraft joined
the circui t. The pilot of the lead aircraft extended the landing gear and flew the initial leg of the circuit at an indi cated airspeed of
96 knots. At the end of this leg the pilot turned t he aircraft steeply to the left , the nose dropped sl igh tly and the ai rcraft flicked
in to a steep right turn . The aircraft then assumed a steep nose down attitude; however, the pilot was able to level the wings and
raise the nose to the level attitude before impact. The impact occurred at a very high rate of sink.
Non-commercial -pleasure
Darwin, NT/Emkaytee, NT
VH -G IK
During the single-seat test phase of the rating test the aircraft was observed to carry out an inspection of the treatment area and
commence spray runs, with the first run into wind . Al the end of the second run a procedure turn right was commenced. Shortly
after reversi ng the turn the nose dropped and the aircraft struck the ground in a near vertical attitude.
Non-commercial - pleasure
C1M,P2M
01 Dec
Amer Air 5A VH-SZV
8411 055
Archerfield, Old./Taree, NSW
0854
Coolangat ta 50 WSW
As he approached the Macpherson Range the pilot was forced to fly around some hills in order to stay below the cloud base. After
crossing a ridge line where t he gap beneath the cloud was about 300 feet , the pilot was confronted by a higher ridge. He
subsequentl y advised that the aircraft could not out-climb the terrain and he carried out a controlled en try into the jungle canopy
about 200 feet below the top of the ridge. Both win gs were torn off; however, the cabin area came to rest intact.
Pitts S1 VH-IGZ
Emkaytee, NT
Czech Blanik
Monarto, SA
14 Dec
1620
C1N
01 Dec
Victa 100 VH-BNV
Non-commercial -pleasure
8421070
Surfers Gardens , Old./Casino, NSW
1030
Chi llingham 20N
The pi lot had recently purchased the aircraft and intended taking it to his local aerodrome. About 20 minutes after departure the
engine suddenly lost al l power and the pilot was committed to a landing on suitable terrain. Whe n inspecting the aircraft after it
had c6me to rest, the pilot discovered a loose con nection in one of the fuel lines.
02 Dec
0859
09 Dec
1400
Injuries
Record number
While enroute to the treatment area the pilot noted a loss of engine power. After the load of superphosp hate was dumped, he
realised he would be unable to return to the departure strip and selected a track as the most suitable landing area. During t he
landing ro ll the aircraft ran over a hump w hich caused it to slew off the track into the surrounding bush.
C1N, P1N
Ferry
30 Nov
Hiller UH12E VH-F BH
Wyena Station, Old./Broadmeadow, Old.
8411054
1330
Mackay, Old. 174 SW
The pilot reported that shortly after commencing to cruise at about 750 feet AGL the helicopter encountered a willy willy and was
thrown almost upside down. During the recovery actions, right pedal was applied rapidly and the operating cable broke. An autorotational landing was initiated but, just prior to touchdown, another willy willy struck the helicopter and it landed while spinning
under the influence of this disturbance.
Non-commercial - pleasure
Canberra, ACT/Goulburn, NSW
Burkhart ASTIR CS
Whitwarta, SA
14 Dec
1020
C1N
Charter-cargo operations
27 Nov
Beech 58 VH- ETV
8421068
Sydney, NSW/West Maitland, NSW
0755
West Maitland, NSW
The pilot advised that when he selected the landing gear down, aerodynam ic noises were normal and the main gear green light
illuminated. When he closed the throttles the warning horn did not sound , however during the landing roll the left gear collapsed
and the airc raft came to rest on t he grass adjacent to the landing runway.
Aerocdr 500A VH-AGA
Goulburn, NSW
04 Dec
1919
Kind of flying
Departure point/Destination
It was reported that the flight proceeded normal ly until during the flare. The glider was lined up with the strip, but during the holdoff it drifted to the right and touched down on the edge of t he marked, 50 metre wide strip. The landin g roll contin ued off the
runway and the starboard wing struck a tree 20 metres from the edge of the strip.
At a height of about 200 feet after takeoff the right eng in e lost power. The pilot feathered the propeller and commenced a gentle
left turn in order to return to the strip. He later advised that the aircraft began to sink towards some large trees and he was forced
to increase the angle of bank in an effort to avoid them. Shortly afterwards the aircraft struck the ground heavily in an adjacent
paddock about 1 kilometre from the strip.
01 Dec
1120
Aircraft type & registration
Location
VH-KYN Instruct ional-dual
C1M, C1N
Whitwarta, SA/Whitwarta, SA
8441030
After travelling 15 metres during a winch-launch the left wing -tip contacted the ground. The instructor immed iately assumed
control of the glider and applied right rudder and aileron but the left wing entered an oat crop on the edge of the s trip. The tip then
dug into soft soil, causing the glider to cartwheel and impact heavily on its nose 120 metres from the take-off position and 35
metres to the left of the centreline.
C1N
23 Nov
Non-commercial-practice
Cessna 210L VH-EDE
8421066
Parkes, NSW/Parkes, NSW
2210
Parkes, NSW
Prior to departure for a nearby aerodrome the pilot dec ided to carry out some prac tice night circuits. He subseq uently advised
that all necessary checks were completed for the first landing, however the aircraft landed with the gear retracted . When the
aircraft came to rest the pilot noted that the gear hydraulic pump motor was still operating. It was determined that the aircraft had
touched down on the gear doors, which were open at the time.
25 Nov
1250
Date
Time
18 Dec
1511
Beech 77 VH-H BI
Archerfield , Old.
Instructional-dual
Archerfield, Old./Archerfield, Old.
C2N
8411058
Th e aircraft was being tax ied from the runway toward s a parallel taxiway. Approaching the edge of the fligh t strip, the instructor
noticed a 20 cen timetre deep spoo n drain in the path of the aircraf t. He took control and attempted to avoid t he drain but the
nosewheel entered the drain and broke off. The presen ce of the drain was indi cated on a diagram of hazardous taxying areas
available to pilots but the area was not marked by cones.
..
C1 F
Conaero LA4-200 VH -AOW Charter-passenger operations
21 Dec
Hook Island, Old.
Lindeman Island , Old./Hook Reef, Old.
84 11 059
1715
Throughou t the afternoon the pi lot had flown the aircraft on a number of sorties in the area. Du ring the subject flight t he pilot
reported abeam a point on Hook Island, enroute to pick up some divers he had dropped off earlier. No further commun icat ions
were received from the aircraft.
·
22 Dec
1951
Piper PA25-235
Dooen, Vic.
VH -SPE
Non-commercial-pleasure
Horsham, Vic ./Dooen, Vic.
C1M
8431040
Prior to the flight the pi lot was given detail s of the paddock in which the glider was located, by the glider pi lot. This information
included reference to power lines on the western side. An inspection ru n into the west was performed at 300 feet AGL and as a
run at a low height towards the east was commenced, the landing gear struck a power line suspended 9 metres above the ground.
The aircraft stru ck the ground in a vertical nose down attitude and came to rest inverted.
22 Dec
1300
Reims 172H VH-EDZ
Ouilpie, Old. 3W
Non-commercial
Ouilpie, Old./Unknown
C1N
8411060
The aircraft was parked, with con trols locked and doors unlocked, by the owner who retained the ignition key. Later, another
person entered the aircraft and operated a number of con trols before experimenting with a car key in the igni tion switch. The
engine started and the aircraft took off from the position at which it was parked . The occupant attempted a land ing but this was
unsuccessful as full power was still selected. Some time later the engine stopped due to fuel exhaustion and the aircraft glided
into scrub near the town. The occupant was later apprehended by local police.
Aviation Safety Digest 124 I v
�PRELIMINARY REPORTS (The following accidents are still under investigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
lniuries
Record number
23 Dec
1117
Cessna 210M VH-MD I
Koc ian Is, WA
Charter-passenger operations
Koolan Is, WA/Derby, WA
C1F , P5F
8451033
After loading the five passengers and their luggage, the pilot taxied the aircraft for take-off from runway 23. The ai rcraft became
airborne approximately 54 metres before the end of the runway. It was observed to descend into a small ravin e off the end of the
runway , then climb steeply, strike wires and somersault before impacting the ground in a near ve rti ca l nose down atti tude.
Followin g the impact, the aircraft cartwheeled once and burst into flames.
24 Dec
1900
Schleicher ASW-19
Waikerie, SA 7E
VH-GWL Non-commerc ial-pleasure
Waikerie, SA 7E/Waikerie, SA
C1N
8441032
Following an outlanding the pilot arranged an aerotow. The takeoff was commenced into wi nd and up a rise . The gl ider became
airborne but on breasting the rise, the tug pilot aborted the takeoff as trees and a fence appeared c loser than expected. The t ug
aircraft which had j ust become airborne tu rned left and the le ft wingtip struck the ground before the aircraft came to rest. The
glider pilot released the tow but the glider's right wingtip contacted the ground then the fence befo re the glider impact ed the
ground beyond the fence.
24 Dec
1900
Glider towing
C1N
Waikerie , SA 7E/Waikerie, SA
8441032
Following an outlanding the pilot arranged an aerotow. The takeoff was commenced into w ind and up a rise. The glider became
airborne but on breastin g the rise, the tug pilot aborted the takeoff as trees and a fence appeared closer than expected . The tug
aircraft which had just become airborne turned left and the left wingtip struck t he ground before the ai rcraft came to rest. T he
glider pilot released the tow but the glider's right wi ngtip contacted the ground then the fence before the glider impacted the
ground beyond the fence.
26 Dec
1335
Piper PA25-235 VH.WGC
Waikerie, SA 7E
Piper PA28·151 VH·PZC
Glenaubyn Stn , Old.
Non-commercial - pleasure
Glenaubyn Stn, Old./Capella, Old.
C1N, P3N
8411060
The pilot reported that, after commencing the takeoff with flaps up, he selected 10 degrees of fl ap and rotated at 60 knots.
Although the aircraft became airborne it did not climb normally. The aircraft struck a telephone line near the end of the strip and
then landed in a paddock before passing under a power line. With full power st i ll appl ied , the pilot attempted to c lear a fence but
the wing leading edges struck fence posts. The aircraft landed heavily and came to rest 478 metres from t he st rip end.
26 Dec
1245
Glas·Flugel 210B
Narri kup, WA
VH·GGY
Non-commercial-pleasure
Narrikup, WA/Narrikup, WA
C1N
8451034
The glider was launched by being towed behind a motor ve hic le. After the glider became airborne, the pi lot s ignal led to the
vehicle driver to slow down. The vehicle driver slowed the veh icle too quickly, the tow rope slackened and the rope d rogue
dep loyed. The tow rope then released from the glider. Because of the position of t he tow rope, below the g lider, the pilot did not
immediately lower the nose, the glider stalled at about 15 feet AGL and landed heav i ly.
27 Dec
1323
Cessna 310R VH·FFA
Moruya, NSW
Charter- passenger operat ions
Sydney, NSW/Moruya, NSW
C1N , P3N
8421074
Following a normal ci rcu it, the aircraf t touched down with the landing gears doors open and the gear partl y ex tended. The gear
collapsed as the aircraft slid to a halt on its under-surface.
28 Dec
0610
Piper PA34-2001
Adelaide, SA
VH-STN
Ferry
Parafield , SA/Adelaide, SA
C1N
8441033
FINAL REPORTS (The invest igation of the following accidents has been completed)
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
lniuries
Record
number
04 Oct
Cessna A 188B VH·TDJ
Aerial agric ulture
C1 M
1515
Robi nvale, Vic. 16E
Meilman Property, NSW/Meilman Property, NSW 8421052
Commercial
38
5000
3000
A gricu ltu ral c lass 1
The pilot had been spray ing a wheat crop for abou t 30 minu tes. He advised that diff ic ulties were encou ntered with t he
stabilisation of the spray pressure. Wh ile attemp ting to adj ust t he pressure c ontrol he temporari ly forgo t the proxim ity of three
high voltage power lines wh ic h crossed th e c ro p. T he airc raft co llided with t hese lines and pit ched down steeply to the groun d.
Fire broke out on impact and engulfed the wreckage.
05 Oct
1456
Comme rcial
Beech 58 VH·WGS
Mount Bon nie, NT
Charter-passenger operat ions
C1 N , P2N
Darw i n, NT/Mou nt Bonnie, NT
8441023
28
1712
78
Inst rumen t rat i ng 1st class
or class 1
The ai rcraft touched down about 300 met res af ter the t hreshold of the 1200 metre long strip, which s loped uphill. W hen the pi lot
realised that the ai rcraft wou ld not stop before t he end of the strip, heavy braki ng was applied . The aircraft overran the st rip and
t he nose gear strut colla psed in the rou gh te rrain.
The pi lot subsequen tl y advised t hat had he init iated brak ing earlier t he ai rcraft wo uld have s topped in the remainin g length. He
had believed that the re was more s t rip leng th avai lable than was act ually the case and it was cons idered probable that he had
bee n deceived by the s lope of the strip .
22 Oct
1615
Stude nt
Piper PA28·140
Moree , NSW
VH-AJW
29
In st ructional-solo (supervised)
Mo ree, NSW/Moree , NSW
36
12
None
C1 N
8421061
A fter complet i ng exercises in the local t rainin g area the pi lot returned to t he circuit. T here was other traffic in t he c ircui t and the
pi lot reso lved to clea r the runway as soon as practicable after landin g. T he touchdow n was normal but s hort ly after the pi lot
leaned forward to g rasp the handbrake the a ircraft swun g sharply to the left. The r ig ht w ing t ip and th e propeller struck the
ground befo re the aircraft c am e to rest .
The landing had been made in crosswind cond it ions. The handbrake is the only brak ing s ystem fitted to t he ai rcraft and as t he
pilot reached for the lever she inadvertent ly relaxed the back press ure on the elevator control, apparen tly with the nose wh ee l
uncentred .
27 Oct
Cessn a 421 B VH -ADK
1220
Kidson Field, WA
Sen ior Comm ercial
26
Non-com merc ial - aerial am bulance
C1 N , P2N
Kidson Field , WA/We ll 33, WA
8451 029
3240
650
Ins trum ent rat ing 1st c lass
or class 1
Jus t after the pilot applied ful l power at the com mencement of the takeoff run , the nose wheel struck an ant hi ll. The nose gear leg
c o llapsed and the airc raft slid a further 15 metres before coming to a stop.
A lthough a st rip in spect ion was carried out b y the pi lot both before land i ng and again wh ilst tax iing, the anthi ll was not no ticed
because of its co lour and composit ion .
28 Oc t
1130
Commerc ial
Piper PA36·300 VH-FEO
Den il iqu in, NSW 25E
39
Aerial ag riculture
C1N
Ell iston AG Str ip/Ell ist on AG Strip
8421057
1200
2000
Agricu ltural c lass 1
The pilot reported that as the aircraft descended through 300 ft on final approach , wi ndshear and an increase in t he rate of
descent was experienced. He applied power to arrest the rate of descent then reduced the powe r setting to idle. The ai rcraft
landed heavily and bounced , the pilot attempted to take corrective act ion bu t the aircraft agai n landed heavi ly. The aircraft was
taxied to the parking area where the damage was noted.
Th e aircraft was being flow n at abo ut 180 feet AGL enrou te to a r ice paddy . The pil ot reported t hat as he overf lew an irrigated
paddock s trong sink was enco un tered. Ful l power was app lied and dumping of t he hopper load was com menced, bu t t he aircraft
touc hed down briefly. With fu l l power stil l appli ed the aircraft became airbo rn e agai n, however another touchdown occu rred
some 250 metres further on and the pi lot c losed the t hrott le. The left win g struck a fence post before t he aircraft came t o rest.
30 Dec
1545
28 Oct
1420
Private
Cessna 182 L
Willaura, Vic.
VH -EFN
Non-commercial - pl easure
Willaura, Vic./Willaura, Vic.
C1M, P1M
8431041
After flying in the loc al area for a time, th e pilot entered a long straight -in final approach for the easterly s trip he had used for take·
off. From a distance he observed that the wind was a light southerly. Fol lowi ng a sl ight bounce o n touchdown, brak ing was
initiated but the airc raft seemed to be travelling faster than normal. The pilot, be lieving that he had landed with a tai l-wi nd, tu rned
the ai rcraft to the north -east to increase the landing roll available. The aircraft overran the area into a fence and firebreak.
De Hav 82A VH -FAS
Jandakot , WA
28
Non -commercial - pleasure
Jandakot, WA/Jandakot, WA
240
20
C1 N, P1 N
8451030
None
The aircra ft jo ined the ci rcuit for a land ing on the d uty runway, 06. On short f inal t he pilot was advised that t here was a 3 knot
tai lw ind. She continu ed wi t h the land ing an d as t he tai l was lowered to the runway, after touchdown, the ai rcraft began to
accele rate and yaw to the left. Corrective act ion was taken and the yaw stopped . However, as the pilot applied the hand-operat ed
brake, the aircra ft agai n yawed quickly to the left and ground-loo ped before com i ng to rest on t he r ight win g t ip and nose. Duri ng
the land ing the w ind had changed from a ligh t nort h easterly to an 18 kn ot sou th westerly.
03 Nov
1320
Private
Cessn a 182-N VH-LMG
Capertee, NSW
56
Non-commerc ial - pleasure
Mu dgee, NSWI Cape rtee , NSW
200
80
None
C1 N, P2N
8421059
The aircraft was t urned on to the base leg o f t he ci rcu it earli er than normal because of c lou d in the area. The pi lot selec ted an
approach s peed 5 knots higher than usual as the aircraft was bein g operated at a greater than normal weight and bec au se of t he
tu rbulence. The aircraft touc hed down on all t hree wheels simultaneously and bou nced . The second touchdown, 100 metres
fu rther along the strip, was on the nosewhee l, which co llap sed.
The aircraft was not correct ly flared befo re t he touchdown , nor was the correct action taken after the bounced land ing . A fter t he
second tou chdown t he nose wheel dug into a soft patch on the s t rip.
04 Nov
1130
Student
Cess na 172H VH-RLT
Charlevi lle, Old.
18
In struc t ional- solo (supervised)
Charlevi l le, Old ./Charlevi lle, Old.
19
8
None
C1N
8411048
The aircraft was proceedin g alon g a taxiway wh ich had a t ruck parked at its edge. The pi lot had wr itten some detai ls on a kneepad whi le chec king the aircraft taxy direc tion and he was observing wind-soc k indications to his right when the left win gtip s t ru ck
t he side of the t ruc k. The aircraft veered left and the wing struck a fork-li ft parked i n fron t of t he truc k.
vi I Aviation Safe ty Digest 124
Avia tion Safety Digest 124 I vii
�FINAL REPORTS (The investigation of the following accidents has been completed)
Date
Time
Pilot licence
04 Nov
1355
Private
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Record
number
Cessna 172-N VH-KZG
Surfers Gardens
Non-commercial-pleasure
C1N, P1 N
Archerfield, Qld./Surfers Gardens
8411049
27
134
19
None
The pilot was aware than an area of the st rip was prone to being soft. On hi s arrival he saw four cone markers across the strip,
about half way along its length, and assumed that they designated the soft area. During the ground roll the aircraft began to slide
sideways, t he nose w heel entered soft ground and the aircraft overturned 230 met res before the cone markers which were 367
metres from the threshold.
The pilot did not ascertain the condit ion of the st ri p before departure. The cones across the centre of the strip were meant to
delineate the serviceable and unserviceable sections of the strip. However, the unserviceable section was not appropriately
marked and the aircraft was landed on t hat section.
17 Nov
0700
Private
Cessna 210L VH-FYR
Lady Barron Is
71
Non-commerc ial-aerial application/survey
Devonport, Tas/Lady Barron Is
7000
1100
None
C1N
8431034
The landing approach was made over a power line which was adjacent to the threshold, and touchdown was made halfway along
the 585 metre strip. Braking was commenced but was ineffective. Attempts to ground loop the aircraft failed and t he pilot steered
the aircraft towards a gate into another paddock. The nose gear was broken off in a ditch short of the gate. After vacating the
aircraft the pi lot noticed that there was heavy dew on the strip surface.
The wind at the time was light and a lo nger strip had not been used because the pilot wanted to get used to landing ove r the
power line. Although the presence of dew on t he st rip coul d not be con firmed, insufficient strip length remained after to uc hdown
to effect a safe landing on a dry st rip.
18 Nov
Cessna 150M VH -WWU
Aerial mu stering
C1 N
1130
Nyang Sin, WA 19E
Nyang Stn, WA 19E/Nyang Station, WA
8451032
Commercial
32
479
350
Instrument rating class 4
Whilst sheep spotting the passenger became visibly agitated and the pilot elected to land. During the landing roll the aircraft
entered scrub but was not damaged. After the passenger disembarked the pilot attempted a flapless takeoff using a c learing
approximately 140 metres in length. The aircraft failed to become ai rborne and hit several trees before coming to a halt in soft
sand.
Prior to the attempted takeoff the pilot did not measure the available length or refer to the flig ht manual 'p' charts . He
subsequently indicated that his judgement was affected by perceived commercial pressure to conti nue the s heep spotting
operation without undu e delay.
28 Nov
1950
Private
Piper PA28-235
Tooradin , Vic.
VH-PDB
43
Non -commercial-business
Cowra, NSW/Tooradin, Vic.
460
15
C1N, P3N
8431035
None
FINAL UPDATES (The investigation of the following accidents has been completed. The information is
additional to or replaces that previously printed in the preliminary report)
Date
Time
Aircraft type & registration
Location
Age
Hours To tal
Pilot Licence
Hours on Typ e Rating
Record
number
11 Aug 83
Cessna 150M VH -RZA
Private
8341926
1130
Amburla HS 11SSW
25
600
75
None
The aircraft was flown back and forth above a quarantine paddock in order to ens ure that no cattle remained. The search pattern
was fl?wn at about 200 feet AGL. Ground marks and broken t rees indicate that the aircraft st ruck the ground in a spin to the right.
Th e pilot does not recall the seq uence of events immediately prior to the accident.
The available evidence indicates that the pilot lost control of the aircraft while manoeuvring at low level. The reason for this loss
of control could not be determined.
02 Mar 84
Cessna A188B-A1 VH-SHK
Commerc ial
8421009
1000
Boggabri, NSW 20N
29
2152
11 55
Agricultural class 1
Just ~fter liftoff for spraying operations the aircraft sank back to the ground and drifted to the left. The pilot dumped the load but
the aircraft became entangled in a fence running along the left side of the strip.
Th e pilot stated !_hat at a height of about 20 feet the aircraft appeared to encounter a wind gu st from the right rear quarter. The
aircraft was heavi ly lade n and the pi lot had been unable to regain full co ntrol before the coll ision wi th the fence.
07 Apr 84
1610
Cessna 180J VH-SHX
Mt Barnett HS 6SW
33
764
Private
400
8451009
None
After a fl igh.t time of 70 minutes, with _a planned fuel endurance of 140 minutes, the engine failed and the pilot was committed to a
forced landing on rock covered terrain. Evidence of a faulty fuel cap and f uel leakage past the cap was fo und.
The engine failed du e to fue l exhaustion. The pilot had been aware of the faulty fuel filler cap before undertaking the flight and
had not monitored the fuel conten ts gauges adequatel y during the flight.
27 Apr 84
Piper PA32-301 VH-JG H
Commerc ial
8421020
1630
Bingara, NSW 9SW
23
960
350
Instrument rati ng 1st class or class 1
T~e strip .had been re_ce_ntly grB:ded by heavy earth-moving equipment which the passengers were to inspect. Before landing, the
pilot earned ou t a strip inspection from 50 feet. After touchdown the pilot was allowing the aircraft to decelerate without the use
of brakes when a soft , graded area containing numerous hidden boulders was encountered. The right main gear leg became
detached from the wing and t he aircraft came to a halt res tin g on the right wingtip.
05 May 84
1230
Piper PA28-180 VH-DWV
Coonabarabran, NSW
37
300
Private
Unknown
8421028
None
The weather conditions wer.e deteriorating as the pilot approached to land. On final approach the aircraft was too high and a goaround was cond ucted. During the subsequent circuit the pil ot inadvertently entered cloud and shortly afterwards control of the
aircraft was lost. The pilot ultimately recovered control ; however, bot h wi ngs were later found to be bent upward s as a result of
appl ied aerodynamic loads.
The pilot arranged for one of hi s passengers to check on the condition of the strip. This was done through a third person with the
wife of the owner of the strip . The landing was made into the late afternoon sun and on touc hdown a passenger advised the pilot
that there were sheep on the strip . Almost immediately the aircraft struck a number of the sheep and the nose gear was torn off.
The aircraft had _been flown some 27 ho urs since the occurrence by a number of pi lots and despi te numerous pre-flight
in spect io ns the airframe damage was not noticed until subsequent periodic servicing.
The strip was surrounded by tall grass which reduced the effective width to 12 met res and hid the grazing sheep. The st rip owner
was aware of the impending arrival of the airc raft; however, the pilot was not advised of the location of the sheep.
31 May 84
Piper PA24-400 VH -BOO
Commercial
8441017
1945
Adelaide, SA
60
864
682
Instrument rating 1st class or class 1
Due to weather conditions at the planned destination, the aircraft was diverted to Adelaide. About 135 kilometres from Adelaide
the engine began to run roughl y, but cruising altitude could be mai ntained. The ai rcraft was positioned ove r Adelaide airport at
2500 fe~t and a right c1rcu1t comm.enced. During the approac h the aircraft began to undershoot and when t he pilot appl ied power
the engine did not respond. The wing was torn off by impact with a power pole and the aircraft struck the ground inverted near the
airport boundary.
01 Dec
Stits SA6B VH-ULB
Non-commercial-pleasure
C1N, P1N
1845
Aldinga, SA
Aldinga, SA/Aldinga, SA
8441029
Private
43
900
50
None
After installing his passenger in the aircraft, the pilot hand swung the propeller, the normal means of starting the engine. When
the engine fired it ran up to high power and the aircraft jum ped the chocks. The pilot attempted to stop the aircraft but it
co ntinued forward and collided with the side of a hangar. The nose gear collapsed and the wooden propeller shattered as the
aircraft came to rest on its nose.
During the pre-start checks the pilot believes he set the throttle almost fully open by mistake. The aircraft handbrake was
unservicable.
15 Dec
1419
Glider
Glasflugel Libelle
Woodbury, Tas
VH-GGQ
60
Non-commercial-pleasure
Woodbury, Tas/Woodbury, Tas
219
58
Glider
C1N
8431038
The pilot reported that an aerotow to 2700 feet AGL seemed to be accomplished quick ly. When the glider had descended to 1400
feet the pilot rejoined the c ircuit but then considered t hat the altimeter was defective. She believed that sufficient height
remai ned to permit a landing at the strip and carried out a low, tight c ircuit. However, as the turn onto final was completed an
immediate land ing flare was required . A heavy touchd own occ urred and the iiircraft came to rest 175 metres after the st rip.
Faulty alignment of the 'thousands' needle in the al timeter had led to the pilot mis-setting the height of the stri p prior to takeoff.
The indications she read from the instrument were therefore 1000 feet in error.
Because of an autopilot malfunction , the pilot had hand flown the aircraft through frontal weather and turbulence for two hours
and was probably fatigued. The engine rough running was caused by malfunctioning valve lifters on No. 5 cyli nder wh ich in turn ,
damaged their valve pus hrods" As the p i l~t had commenced his descent too late fo r a straight-in approach, he overflew the
aerodrome to repos1t1o n .tor.a right downwind . During this descending turn to the right, the engine fai led completely , probably
due to the low fuel quantity in the left tank, which was selected at the time. Approximately 150 litres of fuel was drained from the
other tanks after the accident.
07 Jun 84
1320
Pilatus 84 VH-UIP
Central Mangrove
Glider
8421027
64
136
34
Glider
The pilot was carrying out his th ird flight for t~e day when heavy sink was encountered near a small bushfire and an outlanding
became necessary. Durin g the approach the pilot flew below a set of power lines and then attempted to climb over trees at the
edge
the selected paddock. After passing over the trees the aircraft was seen to descend steeply and st ri ke the ground
crumpling the fuselage and damaging the wing attachment st ru ct ure.
'
O!
The paddock selected by the pilot was the only suitable area in the vicinity. The pilot later advised that when he had cleared the
trees bordering the paddock the. aircraft was. on the poi~t of stalling . He had lowered the nose in an effort to regain airspeed but
had been unable to arrest the high rate of sink before impact wi th the ground.
22 Jun 84
1400
A188B-A1 VH-MX H
Wongan Hill s 16E
35
6000
Commercial
4500
8451015
Agricultural class 1
Prior .to commencing spraying operations for the day the pilot had taken samples from t hree of the five fuel drain points fitted to
the aircraft. Water was detected at each point and further s~mples were taken until no trace of water remained. Further samples
of clean fuel were obtained after two subsequent refuellings. On takeoff after the second refuelling the aircraft fai led to
accelerate normally and co llided wit h a fence after overrunning the strip. Water was later found in the fuel system.
The loss of performance during t he takeoff was due to a loss of engine power,-that probably resulted from water contamination of
the fuel. The pilot was .u naware of ~he position of all the drain p_oints fitted to the fuel system. He assumed that the performance
loss was due to the weigh t of th e ai rcraft, althoug h the two previous takeoffs had been made at a similar weight. When the takeoff
was abandoned, the pilot did not sel ect the best available overrun area.
viii I Aviation Safety Digest 124
Aviation Safety Digest 124 I ix
�FINAL UPDATES (The investigat ion of the fo ll owing acc idents has been comp leted. The information is
additional to or replaces that previously printed in the pre liminary repo rt)
FI NAL UPDATES (The investigation of the fol low i ng acci dents has been comp leted . The information is
addit ional to or rep laces that previously printed in the prelim inary report)
Da te
Time
Airc raft type & regis tratio n
Location
Age
Hours Tota l
Pilo t Licence
Hours on Type Rating
Record
num ber
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type Rating
Record
number
24 Jun 84
1515
Cessna 210M VH-PKR
Bi rchip, Vic 24NW
170
Private
42
8431017
19
24 Aug 84
1300
Piper PA 28-161 VH-PZO
Cessnock, NSW
18
78
Studen t
78
8421041
,
None
The aircraft touched down about 160 metres past the threshold of the 650 metre strip and bounced. The pi lot applied powe r to go
around and progressively raised the fl ap, but the aircraft then began to s ink and he was unable to prevent the left wing striking the
ground. The aircraft cartwheeled and rapidly came to a halt.
During the bounce the ai rcraft had drifted towards a tree on the ri ght side of the strip. The pilot had com menc ed t he left t urn to
avoid the tree and had not straigh tened the flight path for the go-around. Flap retraction had bee n too rapid , consideri ng the
speed and attitude during the turn and the aircraft was probably in a stalled conditio n when contact w ith the ground occurred.
24 Jun 84
1600
Mooney M20F VH ·ERY
Mundabullangana
Private
8451016
No ne
550
5
A go-around was made from the first approach as the aircraft was overshooting the pilot's aim ing poi nt. On the sec ond app roach
the aircraft began to porpoise after touchdown. Braking was commenced with 200 metres of the 750 metre stri p remaining. After a
further 100 metres the pilot attempted to go-around. The aircraft came to rest so me d istance beyond the st ri p end after c o lliding
with a number of mounds of earth .
39
The pilot was inexperien ced on the type. Indicated airspeed on final was 12 knots above t hat recomm ended in the ai rc raft flig ht
manual and a tail wind component of 5 to 8 knot s existed during the landing.
04 Jui 84
1340
Piper PA28-R201
Gympie, Old.
VH -RON
25
115
Private
10
• 84 11031
Instrument rat ing class 4
The pilot was landing in gusting wind condi tions with a cross-wind from the left. After t he left wheel had tou ched down and
before the right wheel had been grounded a gust of wind lifted the left wing , causing the aircraft to drift to t he right. A ttempts by
the pilot to re-land were unsucc essful and a go-around was initiated. The aircraft subsequently co llided with a fe nce post and
came to rest about 180 metres off the side of the runway .
The aircraft encountered a very stro ng wind gust at the time of touc hdown. The pilot delayed action in initiat ing a go-arou nd and
when power was applied th e aircraft was unable to out-climb the rising terrain while f ly ing downwind .
27 Jui 84
1100
Smith 600 VH-PW L
Denil iquin, NSW
47
12500
Commercial
600
8421035
Inst rument rati ng 1st class or class 1
The pilot was carrying out a practi ce s ingle engine landing. The gear was lowered and th ree greens obtained, but as t he nose
wheel contacted the runway the nose gear retracted . Inspection revealed that the d rag lin k t runnion b lock had fai led allowing the
drag brace to s lip over the centre and the nosegear to retract.
The trunn ion attac hment bolts were found to be a loose fit, and movement between t he t runnion bloc k and adjustment st ruc tu re
had res ulted in abnorm al wear.
29 Jui 84
1700
Beech D55 VH-FED
Prescott Lake 16NE
Private
8451018
38
1000
In strument rat ing class 4
500
The strip had been prepared by grading an area amongst sand dunes and the pilot had landed the aircraft there on three previous
occasi ons. During the landing rol l the righ t main wheel broke through the su rface crust of the strip. As the pilot attempt ed to
correct the en suing sw ing the left main wheel al so broke through the surface and t he nose wheel collapsed as it was d ragged
sideways through the sand.
None
M aintenance vehicles were parked on the grass area adjacent to the taxiway. The pi lot was concentrat ing on keeping the aircraft
moving down t he tax iway centre-line when t he left wing s truck a tractor. The aircraft slewed to the left and collided with a uti lity
wh ic h was parked behind the tractor.
The pilot's planned departure time had been delayed because the instructor designated to au thor ise the f light was not in
attendance, and t he assigned aircraft was late returning from a previou s exerci se. By the time t he pi lot had refuelled the ai rcraft
and ob tained authorisati on from an instructor, there remained litle extra t ime to comp lete the flight before last light. The prefligh t briefing g iven was inadequate, no mention be ing made of the presence of maintenance veh icles adjacent to the taxiway .
Wh ile hurried ly taxying for departu re the pilot misju dged the clearance from the win gtip to the vehic les , wh ich were not
di splayin g hazard lights.
31 Aug 84
0830
Piper PA32-300
Leaghur, Vic
VH-CST
Commercial
6
8431024
Instrument rat ing class 4 w ith f light
instructor
Du ring cruising fli ght, fumes were detected in the cab in and the engine began to run roughly. An explosion then occurred in the
eng ine compart ment, deform ing the r ight sid e of the eng ine cowl. The pilot made an emergency land ing in a paddock; however,
the ai rcraft touched down heavily, col lapsing the right main gear. The aircraft s lid t hrough a s ink hole and the nose gear also
coll ap sed. The centre righ t cylinder was subsequently observed to have detached from the engine block.
30
322
Fat igu e failure of two crankcase through-bolts resulted in separat ion of No. 3 cylinder. The forced land ing area subsequent ly
selected contained shal low s ink holes wh ich were d ifficult to see from the air. Du ri ng the land in g flare, the pilot fai led to
compensate for reduced el evator effect iveness caused by lack of prope ller s lipstream.
Commercial- hel icopter
8421044
01 Sep 84
Hil ler UH12E VH -CCU
Boorowa, NSW 9SW
843
323
Agricu ltu ral c lass 1
34
0815
W hil e manoeuvring to commence a c lean-up spray run parallel to a power line, the heli copte r collided w ith a spur l ine. A broken
section of t he cable s truck and seve red the tail boom, control was lost and the aircraft s truck the g round 150 metres beyond the
spur l ine.
The pi lot was aware of the presence of the spur l ine and had crossed it on a number of occasions during the operat ion. He elected
to carry out a previously unplanned clean -up run to dispense the remaining chem ical and temporari ly overlooked the prox imity o f
the w ire. There was some evidence to indicate that the pilot was suffering from fat igue at the t ime of the accident.
09 Sep 84
1630
Robinson R22 VH-IPC
Gidgegannu p, WA
42
1075
Private - he!icopter
21
None
8451024
The pi lot was operat ing in a control zone but was unable to communicate w ith the controll ing agency wh ile the helicopter was on
the ground . He carried out a takeoff and again, wh ile hovering at 200 feet AGL, attempted to communicate wi th the contro l
agency. Sti ll unable to make contact , the pilot let go o f the col lect ive pitch lever, on which t he frict ion was not appl ied, to change
radio frequencies . The helicopter entered a descend ing turn and the pilot was unable to regain control before it struc k the
ground .
Th e pi lot was inexperienced in helicop ter operat ions and while attempt ing to change rad io frequenc ies and hover in condit ions
cond ucive to t he formation of turbulence, he fai led to not ice decreasing engine noise and rotor rpm.
12 Sept 84
0750
Re i ms R172E VH -REV
Goodwood St n 9NNW
31
250
Private
200
8421048
None
Although the pilot had previous ly tested the s uitabil ity of the stri p surface using t he meth od o utl ined in the Visual Fl ight Guide,
the nature of the s urface and subsequent usage had c aused a soft spot to develop.
The pi lot was cond ucting an inspect ion of bore tanks . The fue l selector was in the 'BOTH' pos ition when the eng ine suddenly
failed . The pi lot was forced to land on unsuitable terrain and the aircraft suffe red damage to the main land ing gear su pport area.
In spection of the aircraft found that t he right fuel tan k was empty; however, approx imately nine li tres of useable f uel rema ined in
the left tank. No contributory fault cou ld be found w ith the eng ine or t he f uel system with the exception of an inaccu rate left fuel
gauge. The cause of the apparent fuel starvat ion of the engine could not be determined .
10 Aug 84
0945
15 Sep 84
1152
Hiller UH 12E VH -FBX
Black Springs 13SW
34
807
Com mercial -heli copter
286
Ag ricul t ural class 2
8421038
Cessna 150E
Reekara, Tas
VH -KMJ
48
65
Private restricted
3
None
8431027
The pil ot was conduc ting sprayin g operat ions over a lightly timbererd paddock, f lyin g at abou t 10 feet A GL and 50 knots airspeed .
During t he seventh s wath run the hel icoper main rotor stru ck a branc h o f a tree. The rotor tip weight and fai ri ng were detached
and severe vibrati on develo ped. The pilot attempted to land straight ahead but the ta il rotor st ruc k the grou nd, the helico pter
pitched forward and came to rest on its right s ide.
Th e pi lot had decided to carry out some cross-w i nd c ircuit pract ice after the other pilot on board had carried out circu its on the
into-wi nd s trip. On the f irst ci rcuit, touchdown was made 357 metres into the st rip on the nose whee l and left main wheel
together, followed by the right wheel. The nose gear sustained damage and when t he aircraft touched down again after a short
bounce the propel ler s truck the ground.
The pil ot was relatively in ex peri enced in helicopter agri cul tural operat ions. W hile concen trating o n maintaining t he correct
height fo r the s praying he had misjudged the distance from the rotor d isc to the tree.
The pi lot had not conducted cross-w ind landing practice for about a year. He was inexperienced on the aircraft type and the
cross-w ind component at the time was c lose to t he aircraft lim it.
22 Sep 84
1620
Rol laden LS4 VH -GXP
Kin garoy, Old. 20SW
While the ai rcraft was crui sing at 3000 feet the eng ine RPM suddenl y increased, coincidin g wi th the loss of oi l press ure. The pi lot
commenced a precautio nary landing sequence but after completing a sati sfact ory app roach the aircraft made a heavy landing in a
cleared paddoc k.
8411040
Gl ider
Towards the end of t he f light an outlanding became unavoidable. A paddock w ith a number of trees and a power line at its edge
was selected. During the final approach, after c learing those obstac les, t he g lider contacted another wire runn ing d iagonally
across t he paddock. The w ire hooked under the wing and the glider sl id sideways along the wire for some d istance be fore the
right w ing struck a tree and the aircraft fell to t he ground.
The o il pressure loss was caused by the fai lure of t eet h in t he oil pum p. Before the eng ine was sh ut down , a conn ect i ng rod failed
and i ndu ced seve re vibratio n in the aircraft . The aircraft was flown about 8 knots below t he rec om mended approach speed on late
fin als and probably encountered a wind gus t , indu cing a high sink rate close to the ground.
A sho rt ti me earlier the pilot had selected a different paddock for t he out landing. He had then encountered a weak thermal wh ich
had been u til ised. When the thermal d issipated t he pi lot had drifted away from the selected paddock and had on ly a short time to
se lect an alternat ive paddock.
22 Aug 84
1130
Piper PA32-300 VH -RP B
Skipton, Vic 3SSE
x I Aviation Sa fety Digest 124
35
555
Private
47
8431023
None
40
320
Gl ider
75
Aviation Safe ty Digest 124 I x i
�FINAL UPDATES (Th e investigation of the fol lowing acc idents has been comp leted. The information is
additional to or replaces that p reviously prin ted in the pre lim in ary report)
Date
Time
A ircraft type & registration
Location
Age
Hours Tota l
26 Sep 84
1120
Hiller UH12-E VH-ECK
Galang, NSW 4NE
33
7730
Pilot Licence
Hours on Type Rating
Record
number
Commercial-helicopter
8421051
600
Agricultural class 2 with flight
instructor
Towards the end of a spraying run the pilot noticed that the aircraft was drifting towards a power line running roughly parallel to
the aircraft track. He attempted to counter the drift but the aircraft moved underneath the w ire. The main rotor struck the line as
the pilot attempted to manoeuvre clear and also avoid trees at the end of the sp rayi ng run. After s triki ng the wire the helicopter
swung through 180 degrees and the tail boom collided with a tree.
Although the pi lot had gained considerable experience on helicopters, most of this had been obtained cattle mustering. He
evidently did not real ise that a hazardous situation was developing in time to take safe avoiding act ion.
30 Sep 84
1355
Pitts S2A VH-SZA
Berwick, Vic.
40
470
Private
13
8431028
Instrument rating 1st c lass or c lass 1
The pilot reported that he commenced the takeoff with the control stick fully back and some right rudder applied. As the aircraft
rolled it veered left until the left wheel encountered long grass on the side of the gravel strip. The aircraft tai l, wh ich was in the air
when the grass was encountered, continued to rise until the propeller struck the ground and the aircraft came to rest inverted.
Although the 7.5 metre centre gravel section was firm, the remainder of the strip was soft and wet and could not support the
aircraft's weight. The pilot was aware of the natural tendency of the aircraft type to swing to the left during takeoff but he had not
been able to maintain directional control on the narrow serviceable portion of the strip.
Faulty fuel management
Cast your mind back to the last aircraft you new and
sec if you can recall the fo llowing operational
information :
• total usable fuel capacity
• innight m ixture leaning tech n ique for the
recommended lean mixture setting
• average fuel consump tion at represen tative cru ising
altitudes a nd power settings
• whether or not the aircraft kit contained a calibrated
fuel dipstick
Each o f those factors must be noted when fuel
management is considered, not only during a night but
a lso at the preflight planni ng stage.
I n the accident review which follows, a number of
important fuel managemen t lessons emerge.
The accident
An uneventful afternoon night had been made in a
Cessna 182Q to a country town . At the start of that
flight the pilot had confirmed that the aircraft was fully
fuelled which, he later stated, amounted to 65.5 usable
imperial gallons. For t hat flight he planned on a
consumption rate of 10 gallons per hour (gph), and the
duration of the trip was abou t 3 hours 10 minutes.
Afte r an overnight stop at the town the aircraft was
prepared the next morning for the return flight. I t was
refuelled from drums, and an estimated 18 gallons (all
fuel amounts given in this article now are in imperial
gallons) were added: the assessment here was made by
the refueller. The pilot checked the fuel gauges before
and a fter refuell ing. Each tank showed half full at the
co mm encemen t and three-quarters full at the
completion. The contents were also assessed visually
and had obviously risen. Both of these checks confirmed
in the pilot's mind that about 9 gallons had been added
to each tank. As th e fuel contents had been about half
full on arrival he est imated that the remaining half
wou ld be sufficient fo r the return night, leaving the
additional J 8 gallons as reserve.
Precise calculations made by the pilot were as
follows: 47 gallons of fuel on board which, at 10 gph,
he assessed as about 300 minutes endurance. Planned
flight time was 182 minutes , so with 45 minutes fixed
reserve required, he had a margin of 73 minutes .
T hree passengers were embarked and takeoff was
made just after two o'clock local time. When
established in the cruise at 9000 feet the pilot set the
power at full throttle (20" MP) and 2350 RPM. Mixture
was leaned until the engine ran roughly and then
enriched unti l the EGT dropped three divisions (75 °F).
After about two hours it became necessary to descend
to remain below controlled airspace. During this
descent the pilot gradually enriched the mixture until,
passing 3000 feet o n the way down to the final cruise
altitude of 2000 feet, full rich was selected. This setting
was then maintained.
En route the pilot had run the engine from the right
tank until it was effectively dry : this had been done
deliberately so that he would know 'that all remaining
fuel was in the left tank'. Thus, when cruising at 2000
xii I Aviation Safety Digest 124
feet, the fuel selector was on the left tank. (Note: the
fuel selector posit ions available were I.EFT, BOTH ,
RIGHT and OFF.)
About 25 minutes from the destination, the Cessna's
engine began to run roughly. At this stage the left tank
was indicating one-quarter full. The pilot changed the
fuel selector to the BOT ! I position, wh ich seemed to
cure the problem. He kept the selector on BOTH for
about 2 minutes and then changed back to LEFT
because he thought that, with the 1·ight tank empty and
the selector on BOTH, the engine might 'suck' air.
(While this had no effect on the eventual accident, it
should be pointed out that this belief was wrong. As
long as there is a sufficient head of fuel in either o r
both of the fuel tanks then, with the selector in BOTH,
ample fuel will be delivered to the e ngine.)
Shortly after the selector was returned to LEFT, and
with the left fuel gauge reading about two needle widths
less than one-quarter, the engine again started to run
roughly. A PAN call was transmitted and the pilot
started to look for suitable landing areas.
After the PAN ca ll had been made the engine
al ternately ran normally and roughly. The pilot
positioned the aircraft for a landing on a golf course,
whi le continuing to adjust the th rottle and fuel selector
in his attempts to restore normal power continuo usly .
In fact, on the landing approach the engine was
delivering power. Unfortunately the approach was
misjudged and a go-around was necessary. This was
safely completed, but on downwind for the second
approach the engine stopped completely. In the ensuing
forced landing onto the golf course the Cessna struck a
television antenna, a tree and a chain wire boundary
fence, and was substantially damaged. The engine
failure was caused by fu el exhau stion.
Analysis
One relevant factor to emerge from the investigatio n
was that the fuel quantity calibration card was
incorrect. T he card indicated that with full fuel the left
tank would contain 35 gallons and the right tank 37
gallons, yet the Cl 82Q Pilo t's Operating Handbook
and the D epartment of Aviation Approved Flight
Manual both specified a total fuel capacity of 66.6
gallons and a usable capacity of 62.4 gallons. The
accuracy of the calibration card throughout the
complete range between empty and full was therefore
open to doubt.
Nevertheless, in itself this should not have been
sufficient cause for eventual fuel exhau stion; and here,
other factors emerged. These were related to systems
knowledge and operational technique.
T he incorrectly calibrated fuel contents card
notwithstanding, the p ilot believed that the total fuel
available was 65 .5 gallons, whereas it was in fact 62.4.
T hus , in this case it seems possible that the fuel load
the pilot assessed he was starting with was, in terms of
fligh t time,- deficient some 15-20 minutes. Again, this
should not have been a serious problem - had the
tanks been dipped with a calibrated C 182Q dipstick.
Because they were not, and despite the other checks the
Aviation Safety Digest 124 I 13
�pilot ca nied out, he could not con fidently and precisely
have known the a moun t of fuel in his aircraft.
Assessment of fuel consumption
T he pilot sta ted that he had based his calculat ions for
fl igh t plann ing o n a c:onsumption rate of I 0 gph.
H owever , exa11tination of the performa nce da ta from
the C 182Q Pilot' s Ope rati ng H andbook shows that , for
I he power settings the p ilo t used d uring the fl ight, the
theoretical ave rage co nsump tion rale wou ld have been
a bout 11. 2 gph using the reco m mended lean mixtu re.
T he H an dbook a lw slates th a t 'so me inde te rmin ate
va riables such as mixture leani ng techniq ue, fuel
metering characte risti cs, engine a nd propeller conditio n ,
a nd air turb ulence may accoun t for varia tio ns of 10 per
cent o r more in range and endurance'.
Mixture leaning technique
The techn ique used by the pilot to a dj ust the a ir/fuel
mi xture was not in accordance wilh the recommended
operating procedures.
Fi rsl, during the climb the pilot le ft the mixture
control in full rich , a lt hough the H andbook
recomm ends leaning th e m ixture in the cli mb above
5000 leer. Second, when established a i 9000 feel , he
leaned the mixture to 75 °F below peak on t he ri ch side
o r the EGT curve: the H andbook recom mends a selling
50 °F below peak . Finall y, the low alti tude sec tio n of the
flight was conducted with the mixture in full ri ch
instead of at the recom mended lean mixture.
I n com bin at ion, those three factors wou ld have
resu lted in fu el co mu mpl ion signifi cantly in excess of
that allowed fo r by th e pilot.
The figu res quoted fo r leaning the m ixture wi th t he
EGT, and the fl igh t regimes for which leanin g is
permi tted mentioned here, apply, of cou rse, only to the
C J 82Q: the P ilot 's Operating H andbook a nd Approved
Fl ight Manual must be consu lted to determine exact
recomme nded procedures fo r each a ircra ft type.
H owever , the lessons which eme rged from th is accident
are a pplicable to all pilots and a ll aircraft types •
20°C BELOW
STANDARD TEMP
_g • c
STANDARD
TEMPERATURE
11
·c
GPH
%
BHP
KTAS
20 °C ABOVE
STANDARD TEMP
31
·c
GPH
%
BHP
KTAS
GPH
RPM
MP
%
BHP
2400
22
21
20
19
77
72
67
62
134
131
128
124
13. 1
12.3
11.5
10.7
74
69
65
60
135
132
128
124
12.6
11.8
11.1
10.3
71
67
63
58
136
133
129
125
12.2
11.4
10.7
10.0
2300
23
22
21
20
78
73
68
64
135
132
128
125
13.3
12.5
11.7
10.9
75
70
66
62
136
133
129
125
12.8
12.0
11 .3
10.5
72
68
64
60
137
133
130
126
12.4
11 .6
10.9
10.2
2200
23
22
21
20
73
69
64
60
132
129
125
121
12.5
11 .7
11 .0
10.2
70
66
62
58
133 ·
129
126
122
12.0
11 .3
10.6
9.9
68
64
60
56
133
130
126
122
11.6
10.9
10.2
9.6
2100
23
22
21
20
19
18
68
64
60
56
52
47
128
125
121
118
113
109
11 .6
10.9
10.2
9.6
9.0
8.4
66
62
58
54
50
46
129
126
122
118
114
109
11.2
10.5
9.9
9.3
8.7
8.1
64
60
56
52
48
44
130
126
122
118
113
108
10.8
10.2
9.6
9.0
8.5
7.9
KTAS
CRUISE PERFORMANCE
PRESSURE ALTITUDE 2000 FEET
LEANING WITH A CESSNA ECONOMY MIXTURE INDICATOR (EGT)
Exhaust gas temperature (EGT) as shown on the optional Cessna Economy
Mixture Indicator may be used as an aid for mi xture leaning in cruising flight at
75 per cent power or less. To adjust the mi xture, using this indicator, lean to
establish the peak EGT as a reference point and then enrich the mixture by a
desired increment based on figures in the table below.
CONDITIONS:
2950 Pounds
Recommended Lean Mix ture
Cowl Flaps Closed
Continuous operation at peak EGT is authorised only at 65 per cent power o r
less. This best economy mi xture setting results in approx imately 5 per cent
greater range t han shown in this handbook accompan ied by approximately 3 knot
decrease in speed.
EXHAUST GAS
TEMPERATURE
RECOMMENDED LEAN
(Pi lots Operating Handbook
and Power Computer)
50 °F Rich of Peak EGT
BEST ECONOMY
{65% Power or Less)
Peak EGT
-s·c
20 °C ABOVE
STANDARD TEMP
1s · c
RPM
MP
%
BHP
KTAS
GPH
%
BHP
KTAS
GPH
%
BHP
KTAS
GPH
2400
20
19
18
17
74
69
65
60
142
138
134
129
12.7
11.8
11.0
10.2
71
67
62
57
143
139
135
130
12.2
11.4
10.6
9.8
69
64
60
55
144
140
135
130
11.8
11 .0
10.2
9.5
2300
20
19
18
17
71
66
61
57
140
136
131
126
12.1
11 .3
10.5
9.7
68
64
59
55
140
136
131
126
11 .6
10.9
10.1
9.4
66
61
57
53
141
136
132
126
11 .2
10.5
9.8
9.1
2200
20
19
18
17
67
62
58
53
136
132
128
123
11.4
10.6
9.9
9.2
64
60
56
51
137
132
128
123
11 .0
10.2
9.6
8.9
62
58
54
50
137
133
128
122
10.6
9.9
9.3
8.7
2100
20
19
18
17
16
63
58
54
50
46
132
128
123
118
112
10.7
10.0
9.3
8.7
8.1
60
56
52
48
44
133
128
123
118
111
10.3
9.6
9.0
8.4
7.8
58
54
50
46
42
133
128
123
116
109
9.9
9.4
8.8
8.2
7.6
Operation on the lean side of peak EGT is not approved
MIX TURE
DESCRIPTION
STANDARD
TEMPERATURE
20°C BELOW
STANDARD TEMP
-2s · c
NOTE
When leaning the mixture under some conditions, engine roughness may occur
before peak EGT is reached. In this case, use the EGT corresponding to the onset
of roughness as the reference point instead of peak EGT.
NOTE
For best fuel economy at 65 per cent power or less,
operate at ttie leanest mixtu re that results in smooth
engine operation or at peak EGT if an EGT indicator is
installed.
CRUISE PERFORMANCE
PRESSURE ALTITUDE 10 OOO FEET
14 I Aviation Safety Digest 124
Aviation Safety Digest 124 / 15
�Human factors
{1)F~
A group of friends had hired two aircraft to fly to a
resort for a cam ping holiday over a long weekend . Six
of them left early in one mach ine , leaving one other
pilot a nd a non-pilo t passenger to fo llow. These two
were to travel in a Cessna 206 a nd were to take most of
the camping equ ipment, sleeping bags and food.
When the C206 pilot arrived at the a irport he fou nd
that his aircraft had been double-booked a nd was no
longer available. An altern ative aircraft which was
fl ying· at the time was arranged: the pilot was advised
that it should be ready fo r him a t about mid-day.
Unfortunately it did not return until about ·183_0 hours
local , wh ich was too late for a departu re that day. This
was frust rating a nd upse tt ing for the pilot, who was
concern ed that his six friends had only two sleeping
bags between them and little camping gear and food .
H e arranged to leave as early as possible next morn ing.
On arrival at 0630 the following day the pilot was
further fru strated to find t hat his a ircraft had not been
refuelled. He did the job hi mself, then carried o ut a
normal engine start, tax ied to a position alongside the
equipment and stores, and shut down wh ile he loaded
the Cessna. R <:>ady at last to depart, he and hi s
passenger got into the aircraft - and fo und that the
engine would not start.
Diagnosing the fault as som e kind of electri cal
mal fu nction, th e pi lot decided to attempt a hand start.
A t this juncture he made a series of mistakes, his
judgmcnt perhaps having become clouded by the
number of aggravat ions he had experienced.
The regulations addressin g hand sta r ting are qui te
spec ific. They permi t the pilot-in-com mand of an
aircraft which requ ires an operating crew of only one
pilot .to ' manipulate the propeller of the ai rcraft for the
purposes of start ing the ai rcraft' under the fo llowing
circumstances:
• when the re is no assistance available;
,; when adequate provision is made to prevent the
aircraft moving forward; and
• when no person is on board the a ircraft.
(Note that an appropriately licensed pilot or other
approved person should occupy the control seat if
avai lable: thi s fii1a l req uirement relatt:s to the
circumstances of- 'one pilot ' and 'no assistance
available' .)
In th is case, however, t,he p ilot did not seek proper
a ssistance, nor did he make adeq uate provision to stop
the aircraft from moving forward.
l nstead, he set the park brake and briefed hi s
passenger on the operation ' of the throttle and the toe
brakes . In particul ar he inst ructed the passenger that, if
the engine started but then looked like it was going to
stop , the throttl e should be opened slightly.
The pi lot swu ng th e propeller a nd the engine started
immediately. As the pilot began to board Lhe aircraft
16 I Aviation Safety Digest 124
through the left door, 'considerable power was applied
and the ai rcrafL began to move'. In fact it sccms· tha t
the passenger had inadver tentl y opened the throttle
right up and applied full power.
The sudden ai rstream hlasl blew the door shu t and
preven ted the pilot from getting in the Cessna. At
abou t the same time, the left mai n wheel ra n over his
r ig ht foot.
Veering left a nd gatherin g speed , the 206 headed for
the side of a hangar, which it then struck at a speed of
about 25-30 knots. Ru nn ing to the aircra ft , the pilot
found the passenger on the ground just outside the right
door. H e then got in the a ircraft and turned off the
magnetos and master switch .
Minor injuries were sustain ed by the pilot and
passenger , considerable damage was done to the
hangar, 5 metres of a cha in fence were broken , a hole
was punctured in the side of a nother a ircraft , and the
C206 was destroyed. (See photograph opj;osite.)
Comment
Frustration is a facE of life - it happens to all of us.
U sually we know when we, or som eone we are worki ng
with, arc fr ust rated; and often we recognise symptoms,
e.g. cutting corners, omittin g checks. The problem
seems to be. more one of no t understanding the effects
fru stration can have, rather th an actually recognising
the condition.
Frustration cau ses stress, and stress when it bu ilds up
can have dangerous effects on a pilot 's performance.
T he major problem arises when the pilot _is not aware
of those effects. Mos.I significantly, it is an individual 's
decision-making abil ity and judgmen l , rather than
hands-on fly in g performance, which are particu larly
affected. If the stress of frustration is com b ined with
other stresses - fatigue, personal prob.lems, time
pressures and so on - then the situatio n can become
especially dangerous.
The key point we need to appreciate from all th is is
that frust rat ion increases the chances tha t we wilJ make
an error without being aware of it.
Appreciating this, what can be done?
The best actio n is to stop and take stock of the
situation, and consider the ri sks in herent in letting
frustration get the better of you. T ake yourself out of
the situation fo r a time, both physically and mentally:
take a break , a walk, go for a cup of coffee whatever, relax!
Think about the circumstances that led to the
situat ion . Try to understand what the consequences are
and why you have become frustrat~d. This
un dersta nding can help you to gain control of the
frustrat ion and enab le you to approach your night in a
calm and considered man ner.
R emem ber, a high level of frustra tion leads to a high
level of st ress even if it is o nl y temporary. If an
eme rgency should arise, in th is frustrated condition
your chances of dealing wi th it may be dimini shed •
A C206 destroyed as the result of a series of mistakes following the frustration of a delayed departure (article on opposite
page).
{2)f~t~
An experienced pilot was en route to a large country
cen tre in a single-engine trainer to complete a routine
stint of instruction for his compa ny. It was one of those
perfect days that can make pilots euphoric - clear
skies , warm sun and smooth early morning a ir.
Understandably, the pilot fel t on top o f the world.
It was in this fram e of mind that he noticed he was
approaching a lake. At this stage he unfortunately
allowed his euphoria to override h is good judgmen t. H e
put his aircraft into a descent so that he cou,ld make a
low pass over the smooth waters of the Jake.
At the conclusion of the low pass the pilot pulled up
to clear the dam wall. Unhappily, he liad failed to see a
power line in the same area. Luc~as on his side:
although the wire passed over the 1fose of the aircraft,
through the propelle r and smashed the windscreen, h e
was a ble td fl y away , and damage to the a ircraft was
subsequently assessed as minor.
The pilot summed up thi s incident succinctly himself
in his report:
Obviously I am lucky to be alive and even luckier to have
escaped without injury. Not being experienced at low
fl ying I foolishly assu med that it was safe to fly low as long
as a good lookout was maintained. I realise now that this
could not be fu rther from the truth . Despite the fact that I
maintained constant lookout for such things I did not see
the wire until I was only feet away from it.
I hope that my experience may be used to warn others so
they can avoid the possibility of this by not putting themselves
in the position in the first place.
•
•
•
T he world would be a dreary sor t of place if none of u s
ever ·gave in to the urge for impulsive action . H'o wever,
there is a tim e and a place for ever ything: clearly,
impulsive actions a nd aviation do not mix.
One of the definition s of impulsive behaviour is the
sudden te ndency to act without reflection , and therein
lies the problem. When fl ying an aircraft , actio n
without reflection is like playing Russian Roulette - if
you are lucky you migh t survive.
The real problem in tryin g to combat the tendency to
act ·on impulse is that impulsive behaviour always· seems
like such a good idea at the time, but as the pilot
mention ed in this article found out , it does not always
work out that way.
Impulsive behaviour involves taking action withou t
fi rst thinking a bout the con sequences o f that actio n ,
while responsible safety-mi nded behaviour involves
taking action only after the possible consequences of the
act ion have been considered.
R emember , think first, act second e
Aviation Safety Digest 124 I 17
�Pro
• If a qualified pilot or an approved person is
available, have them occupy the pilot's seat (note
that this is mandatory for all aircraft requiring a
crew of two pilots).
• T he p ropeller swinger should no t wea r any loose
clothi ng - scarf, necktie, headgear, open jacket etc.
- which might become entangled in the propeller or
hinder movement. Footwear should also be suitable,
e.g. no thongs or sandals.
• Establish clear communications with the person at
the controls.
Practising the hand start
Although concerned primarily with ' human factors', the
a rticle on page 16 of this issue of the Digest d raws
atten ti on to some of the possible dangers a propeller
can present. The intention he re is to elaborate on those
dangers and to outline the general propeller safety
procedures pilots should observe in relation both lo
passengers and hand sta rting engines.
Boarding or approaching aircraft
Few aviation mishaps a re more di stressing than those in
wh ich an individual approaching an a ircra ft walks into
a rotating propeller. It is incum bent upon the p ilot in
command to take all measures to ensure that this does
not happen. Essentially, this entails giving a thorough
briefing to passengers before the flight, and maintaining
vigilance at all times o nce the e ngine has been started.
Briefing. You must ensure your passenge rs
understa nd the dan gers of propell ers by stressing the
following points:
• Clearly stipul ate the approach path to the aircraft for
them to use.
• Point out the position of entry doors and the way in
which to get in to the a ircraft.
• Let them know whether the engine will be running.
(Preferabl y it should not be started unt il everyone is
on board.)
·
• E mphasise that they should approach the a ircraft
from the side a nd never walk from the rear to the
fron t of a wing.
• Instruct them always to treat a propeller as live: even
if it is not running, they should never stand in or
pass th rough the propeller arc.
For disembarkation, if possible the engine should be
shut down, but if operational necessity precl udes this,
these additional points must be made:
• In most cases, passengers should walk away directly
behind the main wing and towards the wingtip.
• Direction should not be changed until they are well
18 I Aviation Safety Digest 124
clear of the aircraft.
• A gain , they shou ld never walk from the rear to the
front of a wing.
If it is necessary to load an a ircraft with its engine(s)
running, the loaders/despatchers must be fully briefed
to use only standard procedures and hand signals.
Finally, the importance of the pilot exercising
thorough vigilance cannot be over-emphasised. Bear in
mind that noise a nd excitement may well distract a n
inexperienced passenger; and that part of the danger of
a rotating propeller is its invisibili ty. If you see
someone coming towards your aircraft in a direction
that may put them a t risk, then do not hesitate to shut
the engi ne down. R estarting takes little time or effort,
a nd is infin itely preferable to having someone exposed
to the danger of a propeller. Always r emember propellers can be lethal.
Hand starting
Accidents caused by hand started aircraft runnin g away
conti nue to occur periodically. For some a ircraft types
hand starting is a regula r practice; consequently, their
pilots are well ve rsed in the technique and seldom
experience problems. Difficulties primarily a rise when
those who arc un fam il iar wi th the procedure decide for
some reason - e .g. a flat battery, faulty starter motor
to ha nd start an e11gine , and a re eith er u naware of,
or choose to ignore, the recommended technique.
The following summary of procedures and
co nsiderations covers the major poin ts in the normal
hand sta rting sequence. While not exhau stive, the list
provides for most light aircraft e ngine installations. Like
any operationa l procedure, hand starting should first be
practised under the supervision of a n experienced pilot
or, in this case, a su itably endorsed LAME.
Preparation
• Firmly apply the parking brake.
• Chock the wheels.
• face the a ircraft into wind, preferably towards open
grou nd.
• Ensure that the ground immediately in front of the
propeller is level and firm : slippery grass, mud, oil
or loose gravel could lead to a fall into the propeller.
• Set the engine with magnetos off, fuel off, mixture
idle cut-off and throttle closed.
• Face the plane of the propeller.
• Stand close enough to the propeller to be able to step
away at an a ngle of about 45 degrees to the propeller
as it is pulled down . (Steppin g away is a safeguard
should the brakes fail.) Do not stand in a position
that makes you lean towards the propeller to reach
it, as this may p lace you off balance and cause you
to fall into the propeller when the e ngine starts.
• Place one or both ha nds on the trailing edge of one
of the blades .
• Posi tion the propeller blade for a comfortable swing
against com pression. (Note: cold engines sh ould
always be 'pu lled through' at least two revolutions
before starting to free moving parts and to check
whether a hydraulic lock has formed.) Determine the
most favourable starting position of the propeller for
your ha nd swing and for the particular installation .
• Make a smoo th stroke through compression , pulling
the ha nds down and away as the movement is
completed, simultaneously stepping back from the
propeller arc with the rearward foot first.
• Practise the technique until you are certain of your
competence and safeness.
Starting the engine
• Fuel on.
• Battery master on.
• Prime the cylinders - th roule, mi xture a nd
auxiliary fuel pump as required.
• T h rottle closed, then open for a normal stan - take
care it is not opened excessively.
• Tighten throttle friction.
• Magnetos as recommended for hand starting.
• Swing the propeller using the technique practised.
• After the engine has sta r ted, take particular care to
avoid the propeller while removing the chocks and
moving to th e entrance door.
T he point about always treating the propeller as being
live bears repetition. It must a lso be remembered that
with an impulse magneto even the slowest movement
can cause a primed cylinder to fire. Therefore, even
when turning the propeller slowly for correct
positioning, the techniques a dopted when actually
attemptin g a start must be u sed.
Engine fails to start
•
•
•
•
•
DO NOT OPEN THE T H ROTTLE further than the
normal start position and try to start again.
Magnetos off, throttle fully open , mixture idle
cu t-off.
' Blow out' the engine by swinging the propeller
backwards agai nst normal rotation fo u r full
revolu tions.
Do not reprime.
Repeat start procedure.
Single pilot
In addition to the instructions detailed above, pilots of
aircraft approved for single pilot operations a nd who
need to attempt a hand start without anyone at the
controls should observe the following considerations:
• Passengers must not be in the aeroplane.
• Align the a ircraft so it cannot become airborne - it
is preferable for it to be stopped by a ditch than to
take off unmanned (as has happened).
• Consider attaching ropes to the chocks so that they
can be p ulled dear of the wheels fro m inside the
cockpit.
• Remember that the throttle need be only partially
open to give sufficient power for the a ircraft to jump
the chocks.
• Consider tetheri ng the aircraft to some heavy or
fixed object using the rear tie-down point - but do
not forget to undo it!
*
One last comment
Accidents with propellers often arise because of last minute changes or problems - finding yourself
cramped for taxiing room and calling someone to check
the space available, investigating a minor maintenance
hitch after startup, a late or unexpected passenger and
so on . Each of those events involves someone
approachin g you r aircraft al short notice, perhaps from
an unexpected and irregular direction, a nd possibly
with his mind on something else. I t is up to you , the
pilot , to ensure that in these circumstances safety
standards are not comprom ised •
Aviation Safety Diges t 124 I 19
�No-radio near-miss
The intruder failed to acknowledge radio calls made
to him by both the area Flight Service Unit (FSU} and a
military transport aircraft (which was supporting the
jets).
The lesson to be learned: when approaching to land
or overflying non-controlled aerodromes and Broadcast
ALAS below 5000 feet, ALWAYS listen out and broadcast
a 20 miles inbound call. The pilot concerned should
also think about the extra security he would enjoy
generally by submitting a flight plan and checking
relevant operational information (NOTAMs, weather and
so on) before flight.
Editor's comment
Several months ago a Restricted area was activated
east to the south-w'est, passed directly over the
around my local aerodrome by a Class 1 NOTAM.
aerodrome at an altitude of about 2500-.3500 feet.
The area of restricted airspace was out to a radius of
After the jets passed over the airfield and under
five nautical miles and up to an altitude of
the intruder, they pulled up into a loop. At the top
7000 feet. It became active at 1155 hours local time
of this manoeuvre they were about 1500 feet above
and lasted until 12.35 hours; its purpose was for a
the intruder and .300 metres behind him. From my
display by five military jets.
viewpoint, the GA aircraft effectively flew through
The five jets arrived over the airfield at 1210 in
the centre of the loop. Near the end of the loop the
ose.-foxmatio and.a a,J.ruv-.altituck. trailin._ _ __...._Jets tuxned...to.w.ards..the eaaU;Q commence;: their_ne.AJo.-""-'"..;.;;;......-
1moke.
At exactly the same time a low-wing, retractable
undercarriage, single-engine light aircraft,
registration unknown, and tracking from the north-
20 I Aviation Safety Digest 124
manoeuvre. Had they turned towards the west and
climbed they would have again been in close
pro:dmity to the light aircraft.
Thanks to the reader who submitted this important
contribution.
Presumably the pilot of the GA aircraft was making a
NOSAR NO DETA(LS flight and either did not have a
radio in his aircraft (which seems unlikely given that it
was a retractable undercarriage machine) or had
de.cided not to turn it on.
No-radio flights are permitted in certain areas and
under certain conditions in Australia because they are,
under those specific circumsl/Jnces, considered practical, and
acceptable in terms of flight safety.
However, the Visual Flight Guide (VFG) clearly
stipulates important requirements which all pilots
contemplating this category of flight must observe.
First, a NOSAR NO DETAILS aircraft must not (among
other restrictions listed at VFG 44-2) enter, depart or
transit an AFrZ, a designated remote area, or a
Restricted area.
Second, ANY pilot - regardless of flight category who intends to operate below 5000 feet within 20 miles
of a non-controlled government or licensed aerodrome
or Broadcast ALA, outside an AFlZ or MBZ, MUST
maintain a listening watch on the area VHF frequency
and broadcast his position, level and intentions at
approximately 20 nm from the aerodrome. From this it
follows that no-radio flights are not permitted under the
circumstances detailed in this and the preceding
paragraph.
Finally, the intruder in this occurrence apparently
had not checked the operational information applicable
to his flight. Again to turn to the VFG, 'Even if you are
making a flight for which you are not required to notify
your movements . . . you are still required to make
sure you are familiar with the operational and weather
conditions for your flight'. Had this pilot followed that
procedure, the dangerous conflict with the jets would
never have happened. Either a radio call when airborne
to an FSU or ATC centre or, better still, a telephone call
before departure - and reverse charge at that - was
all that was needed •
Aviation Safety Digest 124 / 21
�l>hotographit tompetitiOJt.
In brief
A home-built minimum aircraft crashed and the pilot
sustained serious injuries during test flying. The
pilot later said that he believed the lateral control
was incorrectly r igged, which created difficulties
when he applied bank. I t also seemed probable that
the aircraft stalled prior to the crash. It was not
fitted with an airspeed indicator: the pilot was
attempting to judge airspeed by 'assessing' airflow .
*
*
*
A pilot undergoing a check fl ight executed an
autorotational landing. A run-on landing was made
but the skids dug into the ground and the helicopter
nosed over. The main rotor blades severed the tail
boom as the helicopter came to rest inverted.
Although high a nd low level aerial inspections of
the proposed area had been carried ouL, neither pilot
had walked over the surface - the only certain way
of assessing its suitability. In the event, the surface
proved to be soft and skid penetration caused the
helicopter to nose over.
*
An uneventful VFR flight had been completed in a
Beech Bonanza. A n ormal c ircuit and landing was
flown, witho ut any unusual circumstances which
might have distracted the pilot.
The pilot ma de a particularly good landin g and, as
the aircrafL slowed, he went to retract the flaps, as
was his habit. In doing so, he mistakenly moved the
landing gear selector to the UP posi tion. He
immediately realised what he had done and
reselected DOWN, buL the retract cycle h ad already
begun , and the wheels con tinued to retract. Damage
to the aircraft was substantial.
*
T he Aviation Safety D igest is pleased to a dvise readers that it is conducting a pho tographic competition fot all
Australian aviation enthusiasts .
*
Before takeoff a passenger in a C210 placed a
cassette player on the instrument coaming. It was
not noticed by the pilot - nor was the fac t that the
cassette cau sed the compass to misr ead by 20
degrees. When the pilot then used the coi;npass to fly
his departure headings, the error caused hi m to
tran sgress his departure clearance e
*
T he co mpetition is being sponsored by Maxwell
Optical Industries P ty L td, the Aus tralia n distributors
of Niko n camera s and photograp hic equip men t.
Two prizes w ill be awarded:
• one for the best p icture having as its theme
Australian civil aviation;
• the other for the best picture h aving an Au stralian
civil avia tion safety theme.
Clarification
. Aviation Safety Digest 118/1983 inclu ded an article
entitled ' In co rrect Glider L aunch '.
It has been suggested that this article did not
accurately re flect the pu bli shed findings of the relevant
accident investigation and was there fore unfair to
persons associated with the particu lar accide nt.
The article stated , among o ther things, that
- th e m a in factor which emerged during the
in vestigation into this fatal acc ident was that the
glider was confi gured for aero-tow launchi n g with
the towhook on the.forward attachm ent point, and
the hook was not repositioned to the rear a llachmen t
point for the winch o pera tions
- b ecause the y did not check the fl igh t manua l, the
pilot involved a nd hi s com panion s were not aware of
this requirement
- they were also not aware that the flight manual
stated that porpoising could occur if winch launches
were made using the forward attachment point.
W ith regard to the firsL malt cr, the relevan t Aircra ft
Accident Investigation Summar y R eport did not
expli citl y identify any 'ma in factor' as having caused
th e accident . The Summa ry R eport did ide ntify t he
pos ition of the towhoo k as a 'cont ri butory ' cau se of the
accident .
22 I Aviation Safety Digest 124
In relation lo the other two m atters, whether or not
the p ilot and his co mpanion s had checked the Oight
manual and were famil iar with its conte nts was not
am ong the matters whi ch the accident in vest igation
directl y looked into. H ence the st atemen ts in qu estio n
were not established fact, but were logically based
co nclusions reached in the acc ident in vestigation. It is
acknowledged tha t di fferen t conclusio ns fro m those
stated co uld have been reach ed from the avail able
evidence.
T he fundamenta l objecti ve of the invest igation of an
ai rcraft acciden t is the p reven tion o f accid ents.
Similarly, the sole purpose in publishing details of a n
accident invest igat ion is sa fe ty educa tion . T he article
' In co rrect Glider Launch ' sought to refl ect those
objectives •
T he prize fo r the best ci vil aviation p icture is a
Nikon FE2 valued at $650 a nd the prize fo r the safety
theme picture is a N ikon FG-20 valued a t $360. Both
prizes have been supplied by Maxwell O ptical
industries.
The FE2 is a 'state of the a rt' 35 mm single len s
reflex (SLR ) camera and was judged the 1983 SLR
C a mera of the Year by Australian C a mera C raft
Magazine. The FG-20 is a fully automatic 35 mm SLR
ape rture-priority auto exposure camera which also
provides a facility for manu al over-ride. Both cameras
will be equipped with a 50 m m 1. 8 N ikon E lens and
an ever-read y case .
An y nu m ber of p ictures can be en tered by
ind ivid uals as either colour o r black-and-white
13 cm x 18 cm p rints , or colour transparencies.
Entrants should include name a nd address, tele phone
number , m ake of camera, details of fi lm, a pertu re,
sh u tter speed a nd a short descriptio n of the picture on a
sepa rate sheet secu rely fixed to each entry .
Entries will be accepted up un til the last mail on
24 May 1985 and should be addressed to:
Aviation Sa fety Digest Photographic C om petition
Bureau o f A ir Safety Investigation
GPO Box 367
CAN BER RA CITY, ACT 260 1
P hotographers will retain copyrigh t to their p ictures,
except for the two winn ing entries. In addit io n , the
Burea u ma y wish to pu blish a number of o ther en tr ies
along with the winnin g pictures in Aviation Safety Digest
125 in Ju ly 1985 a nd mou nt a d isplay.
T he com pe tition is open to all photographers with a n
interest in civil aviat ion, with the exception of the staff
of the Bureau a nd M axwell O p tical Industries and their
immediate families. P ictu res can cover any aspect of
civil av iatio n - aircraft in fl ight or on the gro und,
a irways op erat ions, maintenance or r unway facilities,
passenger servicin g etc.
The Bureau will take all reasona ble care of entries
su b mitted but cannot accept resp onsibility for n on receipt, loss or dam age. T he judging p an el will consist
of the Editor of the Digest, another mem ber of BASI ,
and a photographic specialist fro m outside BASI. Their
decisio ns will , of course, be final •
Aviation Safety Digest 124 I 23
�
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1985
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�Contents
Solitary waves and low-altitude
wind shear in Australia
D. R . Christie and K. ]. Muirhead, R esearch School of Earth Sciences, A ustralian National University, Canberra.
3 Solitary waves and low altitude wind shear
in Australia
This article draws attention to the hazard associated
with large amplitude sol itary waves and describes
recent progress in the identification, detection and
prediction of this important type of low-altitude wind
shear disturbance.
9
Division of responsibility
Failure to decide who was the pilot-in-command was
the basis of an incident involving two pilots with a total
combined flight time of 20 OOO hours.
10 Engine failure on takeoff
The records show that wllen a genuine - and therefore
unexpected - engine failure occurs the pressures
associated with the 'real thing ' can cloud a pilot's
judgment. Engine fai lures ought to be practised with
this in mind.
12 Fatigue leads to confusion
An accident in which a t ired stockman exited a Cessna
in the wrong direction and walked into the propeller
brings a reminder of how dangerous it can be to work
with moving machinery when fatigue has accumulated.
13 An untrained mustering pilot
A young inexperienced pilot who accepted employment
mustering cattle without having undergone proper
training was killed when his Cessna stalled during a
wing-over turn.
14 Landing area standards
Two expensive accidents demonstrate that persistent
disregard of ALA standards is likely, in the long run, to
be disastrous.
16 Declare your emergency
By fai ling to declare an emergency, pilots needlessly,
and often irresponsibly, expose their passengers, their
aircraft and themselves to additional, unnecessary risk
by possibly delaying the call out of rescue services.
17
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to
Australian licence holders (except s tudent pilots), regis tered
aircraft owners and certain other persons and organisations
having an operational interes t in Australian civil aviation.
Unless otherwise noted, articles in this publication are based
on Australian accidents or inciden ts.
Reader s on the free list experiencing problems wi th distribution or wishing to notify a change of address should write to:
The Publications Distribution Officer
Department of Aviation
P.O. Box 18390, Melbourne, Vic. 3001
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©Commonweal th of A ustra lia 1985
ISSN 0045-1207
R841151 Ca t. No. 84 1558
Printed by Ambassador Press Pty. Ltd.
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Nothing on the clock but the maker's
name - literally
18 Complacency and aircraft knowledge
Reader contribution.
19 Seat collapse on takeoff
20 It's not worth the risk
The pilot of a Piper PA 18 twice elected to land on a
claypan with a distance of 120 metres, half that
required by the P-charts. On the second occasion, poor
maintenance of the engine and wheel brakes resulted
in him being able neither to effect a go-around nor t o
stop the aircraft safely.
21
Why didn't I see that wire until too late?
Your visual apparatus is not sufficiently sensitive to
spot wires from the air.
22
Keep flying your aircraft
Emergenc ies and less dangerous inflight occurrences
must assuredly be dealt with, but never at the expense
of maintaining cont rol o f t he aeroplane.
~23
Photographic competition
2 1 Aviation Safety Digest 123
Cover
Approaching Morning Glory roll cloud format ion produced by
a solitary wave propagat ing in a maritime Inversion towards
the s outhwest over saline coastal f lats near Burket own,
Queensland, short ly after sunrise on 1 October 1981. The
base of t his ro ll cloud is est imated t o be about 0.3 km and
the t op lies at about 1.5 km. Note t hat the position of t he
cloud marks a complex locali sed re·g ion of strong horizontal
and vertical wind shear near the surface.
I t is widely recogni sed that on rare occasions a ircraft
encoun ter unexpected and dangerously intense wind
shears during final ap proach or on takeoff. In most
cases, the p ilot is able to under take corrective
procedu res a nd the aircraft con tinues for a nor mal
takeoff o r landing. T here have, however, been a
significan t num ber of m ajor a ircraft accidents in recent
yea rs wh ich have been attributed directly to a sudden
encou n ter with severe low-altitude win d shear in the
airport en vironment . T he pr incipal conclusion from the
recent review 1 of the avia tion wind shear prob lem by
the N a tion al A cade m y of Sciences and the Fed eral
Aviation Administration in the U n ited States is that
' low-al titud e wind var iabili ty (or wind shear) p resents
an infrequent but highly significant h a zard to aircraft
la nd ing or taking off'.
Aviation wind sh ear may be defined as a ny cha n ge in
wind speed o r win d direction over a short dis tance,
in'cluding up- and down-d ra ug hts , which leads to a
deviation of an aircraft from its intended fligh t path. I t
is gen erally agreed that the most haza rdous forms of
wind shear a re those which result in a sudden loss of lift
either immed iately after takeoff or during the cr itical
fi nal approach stage where safety m argin s are mini mal .
L arge jet-p owe red a ircraft , with th eir relatively slow
response, appear to b e pa r ticularly susceptible to an
encounter wi th severe low-level wind shear. Unexpected
wind sh ear in th e airport terminal area can, however,
present a serious hazard to all types of aircraft.
A n umber of a r ticles on win d shear related aircraft
accidents, b oth in Austr alia and overseas, have
app eared in the A viation Safety D igest in recent yea rs. In
the United States alone, low-altitude wind shear in the
term inal area has been identified as the most important
causal factor in at least 24 major commercial airline
accidents. I t m u st be expected that low-altitude wind
shear has also been a major contribu ting factor in a
significan t number of general aviation accidents.
Anderson and Clark (A viation Safety D igest 106) have
recently carried out a thorough sur vey investigation
which shows that wind shear is a significant operatio nal
problem in Australia .
Meteorological conditions for low-altitude
wind shear
H azardous low-altitude wind shear can be a ssociated
with a wide variety of meteorological phenomen a ,
including mountain lee waves and eddies, noctu rnal
boundary-layer jet streams, sea-breeze and cold fron tal
systems, thunderstorm s and other precipitating
convect ive storm systems, and large a m plitude solitary
wave disturbances. With the exception of solitary
waves, these meteorological wind she ar sources are
easily recognised and can often be predicted well in
advance in the a irport terminal area. P ilots and Air
Traffic C ontrollers are generally well aware of the
potentially severe h azards associated with thunderstorm
downb ursts and with thunderstorm outflow gu st fronts.
The microbur st - a p articularly intense localised
convective downburst - has received a great deal of
atten tion since the wind shear-induced crash of E astern
Airl ines Flight 66 at New York C ity's K ennedy Airport
Low-Altitude Wind Shear and Its Hazard to Aviation. 1983 . National
Academy P ress, W ashington , D .C ., 128 pp.
Aviation Safety Digest 123 I 3
�in 1975 and the severe hazards produced by these shortlived treacherous disturbances are now widely
appreciated in the aviation community. In contrast,
la rge amplitude solitary waves have only recently been
identified as a significant source of intense transient
low-altitude wind shear. These propagating boundarylayer waves, which are commonly found in many a reas
of Australia, are a particularly insidious form of
dynamic wind shear, since they usually occur without
warning as a sudden unexpected clear-air disturbance.
In many wind shear accidents it h as been possible to
associate the hazardous shear with one of the wellknown meteorological wind shear conditions. In some
instances, however , the identity of the low-altitude wind
shear source has been uncertain. In this regard, it is of
interest to note that of the 93 meteorologically related
wind shear incidents in Australia compiled in the
survey by Anderson and Clark, only 15 could be
attributed to frontal and thunderstorm activity. The
remaining incidents were categorised as vertical shear of
horizontal wind (31 incidents) and down-draught
(47 incidents). Large amplitude solitary waves produce
horizontal and vertical wind shears, including
significant localised up- and down-draughts, which are
comparable with other known forms of hazardous lowaltitude wind shear. In view of the ubiquitous nature of
these commonly occurring waves, it is likely that some
of the incidents noted in this survey, and quite possibly
other hitherto unexplained aircraft accidents, both in
Australia and elsewhere, can be accounted for by
solitary wave activity in the atmospheric boundary
layer. The primary purpose of this article is to draw
attention to the hazard associated with large amplitude
solitary waves and to describe recent progress in the
identification, detection and prediction of this important
type of low-altitude wind shear disturbance.
Solitary waves
Solitary waves in the lower atmosphere take the form of
remarkably large amplitude, single-crested waves of
eleva tion which propagate predominantly as clear-air
disturban ces in boundary-layer inversion wave guides.
One of the best-documented accounts of an accident
apparently attributable to intense and unexpected
low-altitude wind shear was that involving an F27 at
Bathurst, NSW, in May 1974.
When the aircraft's crew called Bathurst for a
weather check about 6 minutes before the subsequent
accident, conditions seemed generally fine, with the
surface wind from the north-east at 5 knots. An
approach was commenced but, because the F27 did
not become properly aligned with the runway, a goaround was initiated - as it turned out, 24 seconds
before ground impact. Investigators later determined
that, when the go-around was commenced, the
aircraft was experiencing a headwind component in
the order of 30 knots; this headwind component
became variable some 16- 10 seconds before impact,
and the aircraft experienced a tailwind in the order
of 30 knots during the final seconds of flight.
The Accident Investigation Report concluded that
the cause of the accident was that during the go-
4 I Aviation Safety Digest 123
The first definitive observations of these essentially nonlinear travelling wave disturbances were made in 1976
at the Australian National University's Warramunga
Infrasonic Array near Tennant Creek in the arid
interior of the Northern T erritory. A number of
detailed investigations have been carried out in recent
years to determine the basic meteorological factors
which govern the evolution of th ese commonly
occurring disturbances as they propagate over the
Northern Territory and north Queensland. Although
extensive well-documented records are as yet lacking for
many areas in Austr<1ilia, sufficient evidence is now
available to show that solitary wave-dominated
disturbances occur frequently and are particularly welldeveloped over much of the Australian region. This
regional factor can be attributed largely to the
featureless, semi-desert terrain which distinguishes
much of the Australian continent.
Solitary waves are by no means unique to Australia.
Waves of this type are now known to occur on occasion
over southern England, northern Ge rmany, the central
Mediterranean region and North Africa. In addition , a
number of detailed observations of these disturbances
have recently been reported from the Great Plains area
in the central United States. Non-linear wave
disturbances of this type are a commonly occurring
feature in the lower atmosphere and will generally be
found wherever suitable boundary-layer conditions
exist.
Solitary waves a rise quite naturally as the long-lived
component in the deca y of a wide variety of
atmospheric disturbances. Waves of this type a re
exceptionally stable and, under ideal conditions, may
propagate as coherent entities for many hundreds of
kilometres. A noteworthy feature of the structure of
large amplitude solitary waves is a region of
recirculating fluid which is carried with the disturbance.
Larger amplitude waves of this type take the form of a
propagating horizontal vortex which may produce
particularly severe low-level wind shear conditions.
Solitary waves are observed to occur either as single
isolated waves of elevation or , mor e commonly, as
around the climb performance of the aircraft was
adversely affected by an unpredictable encounter
with a large change in the horizontal wind
component, and an associated downdraught, at a
height too low to effect recovery.
HEIGHT
(METRES)
OL-~~~~~...l.....~---'-~~~--L-~_J,_~~~~-=,,,.,,,.,,._~~~~~
-12000
-6000
0
POSITION
6000
12000
X (METRES)
Figure 1. Model calculation of the relative streamline pattern corresponding to a typical well-resolved family of solitary waves
propagating in a boundary layer inversion.
groups of spatially separated, well-developed,
amplitude-ordered solitary waves, and, in an early stage
of formation, as partially resolved waves associated with
the actively evolving leading edge of a disintegrating
long-wave, or internal bore-wave, disturbance. The
typical scale and structure of a three-component
boundary-layer solitary wave disturbance is illustrated
in Figure 1. Individual solitary waves are most
commonly observed with amplitudes between 300 and
1000 metres and with effective horizontal scales from
0 .5 to 6 kilometres. They usually propagate with speeds
between 6 and 16 metres/second (m/s) but on occasions
they have been observed to propagate with speeds
exceeding 20 m/s (approximately 40 knots).
The passage of a solitary wave disturban ce over the
airport terminal area is marked by a complex lowaltitude wind shear disturbance with a typical lifetime of
about 4 minutes. This transient shear disturba nce is
characterised by rapidly varying horizontal winds near
the surface compounded by strong up- and down draughts associated with the leading and trailing edges
of the wave. T he vertical wind component in these
disturbances is typically about 5 m /s bu t may on
occasion exceed 8 m /s. Maximum horizontal winds are
found at the centre of the disturbance near the surface
a nd are usually in the range from 10 to 15 m/s;
significantly higher winds may occur in individual
solitary waves which contain a region of recirculating
fluid .
Since a ny disturbance in the lower atmosphere can be
expected to generate solitary waves on an existing
inversion , the origin of these waves can be attributed to
a wide variety of meteorological phenomena ranging
from mid-la titude cold frontal systems to intense
thunderstorms. One recent result, which is clearly an
important factor in the prediction problem for transient
shear disturbances of this type, is the observation that
seemingly benign long internal bore-wave disturbances
in the lower atmosph ere can evolve over a period of less
than one h our into a series of well-d eveloped solitary
wave wind shear disturbances. Low-level wind shears in
the residual disturbance behind the primary solitary
wave componen ts tend to be small and are of little
significance to the subject of air safety.
Observations of solitary waves in Australia
Solitary waves can be expected to occur wherever
conditions of low-level atmospheric stability prevail.
Waves of this type may occur at any time of the day in
coastal regions of Australia which are subject to a
persistent marine inversion a nd in most inland areas
during the night-time and early morning daylight
hours. These waves are progressively destroyed over
land by convection and are seldom observed in inland
areas during the afternoon . Solitary waves are unstable
in mountainous areas and are therefore less likely to be
found over the highl ands of southeast Australia. Some
examples of the occu rren ce of solitary wave
disturbances in Australia a re as follows:
Clear-air disturbances in central and
northern Australia
Over 1000 large amplitude solitary-wave-dominated
disturbances have been recorded over a 9 year period
on a high -sensitivity microbarometer array at
Warramunga n ear T ennant Creek. These waves have
been observed from all directions and a t all times of the
year. Solitary waves of larger amplitude occur most
frequently between August a nd November and
originate predominantly to the north and north-east in
the direction of the Gulf of Carpentaria. On many
occasions, two or more independent large-amplitude
non-linear wave disturbances have been observed to
propagate over the T ennant C reek area from different
directions within an 8 hour period. Detailed field
studies have shown that these complex boundary-layer
disturbances often have wavefronts which extend for
hundreds of kilometres and they often propagate for
distances in excess of 500 kilometres. One important
conclusion from these extensive observa tions is that
waves of this type almost invariably occur without
warning in the arid interior of Australia as sudden
unexpected clea r-air disturbances. Since solitary waves
in inland areas usually propagate on the nocturnal
Aviation Safety Digest 123 I 5
�manifestatio n of particularly large amplitude solitary
waves with closed circulation propagating on a
mar itime inver sion .
Pre-frontal solitary wave disturbances over
southern Australia
Sea-breeze and cold fro ntal systems are a significant
source of solitary wave activity over southern and
south-eastern Australia. L arge amplitude solitary-wavedominated disturbances, similar to the non-linear wave
disturbances seen over northern A ustralia, have been
reported from both coastal and inland areas of South
Australia and Victoria, and from the interior of N ew
South Wales. These propagating wind shear
disturbances appear to originate p redomin antly in
frontal systems and occur most frequently during the
spring and summer m onths. P re-frontal wind squalls of
this type exhibit a high degree of variability in their
properties; they can occur up to several hours in
advance of the main fron tal air mass and may, on
occasions, present a difficult short-term forecasting
problem for aviation, especially when they occur
without cloud.
Solitary wave wind shear and
aircraft performance
Figure 2. The above photograph depicts a unique example of a roll cloud over Spencer Gulf, South Australia. The picture was
taken at 1.15 pm, 27 November 1977 by the co-pilot of an Airlines of South Australia aircraft while on approach to land. He
estimated the length of the cloud to be 5 kilometres. The camera was pointing west and a further faint roll is iust visible to
the west of the main one.
The ship near the centre of the picture was the Danny F, which was 230 metres long. This puts the thickness of the roll
and the height of its base around that figure.
A north-easterly airstream had resulted in humid sultry conditions over most of South Australia, with isolated
thunderstorms a day or so before the event. An interaction of this air mass with a cooler south-easterly anti-cyclonic flow
towards the South Australian coast undoubtedly contributed to the formation of this we/I-defined roll.
inversion , large amplitude waves of this type will
normally present an operational problem for aviation
only during the night-time and early morning hours
prior to the break-up of the radiation in version layer.
Visible solitary waves over the Gulf of Carpentaria
Solitary waves in coastal areas are sometimes
accompanied by a low-level propagating roll cloud
formation. The Morl)ing G lory (cover photograph) is a
spectacular visible manifestation of a solitary wave
propagating on a maritime inversion. These remarkable
roll cloud formations, which frequent the southern
margin of the G ulf of Carpentaria during the spring,
are accompanied by strong wind squalls which may
present a hazard to aviation. Similar propagating roll
cloud formations are seen on rare occasions in other
maritime areas of Australia. Figure 2 shows a relatively
small amplitude, but exceptionally well-formed, solitary
wave roll cloud over Spencer Gulf in South Australia.
It should be emphasised that ver y few solitary wave
disturbances are accompanied by roll cloud formations.
Even under the tropical humid conditions which prevail
. along the southern coast of the G ulf of Carpentaria,
6 I Aviation Safety Digest 123
The complex, rapidly varying wind shears produced by
large amplitude boundary layer solitary wave
disturba nces can affect the performance of aircraft in a
variety of ways. Perhaps the most serious situ ation
occurs when a n aircr aft unexpectedly encounters a
solitary wave disturbance from the front during the
critical final approach stage (see Figure 3). In this case
the aircraft is ini tially displaced above the glide path
under the positive influence of increasing head winds
coupled with the up-draught along the leading edge of
the disturbance. This brief per iod of positive lift is
followed by a sudden loss of lift as the aircraft
penetrates the region of rapidly decreasing head winds
and down -draught alon g the t railing edge of the wave.
In most circumstances, the normal reaction of a pilot to
the initial increase in lift during final approach would
be Lo decrease air speed in an attempt to return the
aircraft to the standard glide path; this action, coupled
with the sudden loss of performance along the trailing
edge of the wave, could leave the aircraft dangerously
close to the ground in a potentially disastrous runway
undershoot situation . This particular behaviour pattern
- a temporary period of positive performance followed
by a sudden loss of lift - is characteristic of many lowalti tude wind shear accidents. In a similar manner, an
encounter with a solitary wave from the opposite
direction d uring the approach stage could lead to
runway overshoot conditions.
Most wind shear accidents occur during the final
approach to the runway. W hile the degree of hazard is
usually less severe during takeoff, an encounter with a
large ampli tude solitary wave immediately after takeoff
would cerLainly be a cause for concern a nd could in
some cases lead to difficulties in clearing obstacles along
the flighL path and, perhaps, to stall conditions. Solitary
waves may also be encoun tered during landing and
takeoff at oblique angles to the wavefront. U nder these
conditions aircraft will be subject to both varying lift
characteristics and rapidly changing crosswinds which
will increase the p ilot's workload and thus increase the
risk of an acciden t.
DIRECTION Of
WAVE PROPAGATION
large amplitude solitary wave disturbances occur more
often than not with out warning as clear-air
disturbances.
The southerly buster
The southerly buster, an intense southerly wind squall
which frequen ts the coast of New South Wales, is a
familiar feature of the weather in the Sydney area
during the spring and summer months. This
disturbance is often accompanied by severe convective
storms; it also frequently occurs as a sudden unexpected
clear-air disturbance with low-altitude winds in excess
of 15 m /s which may present a wind shear hazard to
aviation along the New South Wales coast. The
phenomenon seems to be invaria bly associated with the
passage of a cold frontal system across south-e.ast
Australia. On occasions, the southerly buster is
accompanied b y a spectacular propagating roll cloud, or
a series of roll clouds, aligned perpendicular to the
coast. In a number of cases the southerly buster can be
identified as a coastally trapped density curren t ; on
many occasions, however, the observational eviden ce
indicates that the southerly buster is a vivid
300
HEIGHT
(METRES)
__
150 ._
O '--~~~~_._----~J__~~-=-~~_J,_~~~~~~-=~
- 3600
- 1800
0
1800
3600
POSITION X (METRES)
Figure 3. Illustration of the possible behaviour of an aircraft leading to runway undershoot during a head-on encounter with a
large amp litude solitary wave on final approach. Maximum horizontal winds occur at the centre of the disturbance near the
surface .
Aviation Safety Diges t 123 I 7
�Solitary waves, convective microbursts and
thunderstorm gust fronts
Large amplitude solitary waves, convective microbursts
and thunderstorm outflow gust fronts appear to be the
most serious forms of low-altitude wind shear hazard to
aviation. The effective horizontal scales of all of these
transient wind shear disturbances are in the order of a
few kilometres and they therefore have a strong
influence on the behaviour of aircraft over the terminal
area. The relative importance of each of these wind
shear disturbances to air safety may be assessed from
the compilation of their properties given in Table 1.
Pilots will often be forewarned of the possibility of
convective microbursts and thunderstorm gust fronts
over the airport area. In contast, solitary wave
disturbances are much more difficult to predict, since
they usually occur as clear-air disturbances and are
often found at g~eat distances from their source. It is
worth noting that the performance of an aircraft during
a head-on encounter with a large amplitude solitary
wave (Figure 3) is remarkably similar to the behaviour
of an aircraft during an encounter with a convective
microburst. In the latter case , an aircraft may first
encounter a brief period of positive performance
(increased lift) due to the sudden onset of outflow
headwinds followed by a potentially serious loss of
performance as the aircraft penetrates the downflow
region coupled with the onset of outflow tailwinds.
Down-draughts and rapidly varying horizontal wind
components distinguish the solitary wave wind field
from the more benign wind shear pattern associated
with thunderstorm outflow gust fronts. Since solitary
waves most often occur in amplitude-ordered wave
packets (Figure 1) formed in the decay of long internal
bore waves, the winds in these disturbances are
gen e rally much more complex than those found in
simple thunderstorm outflow systems.
Wind shear detection and prediction at airports
An effective wind shear detection and warning system
for operational u se at airports should provide an
accurate short- term foreca st of the severity and nature
of all types of low-altitude wind shear in a form which
can be easily interpreted and rapidly communicated to
incoming and outgoing fligh ts. Some types of wind
shears, su ch as those a ssociated with sea-breeze and
cold frontal systems, mountain lee waves and nocturnal
boundary-layer jet streams, can often be predicted,
sometimes hours in advance , o ver the airport area.
Solitary waves, convective microburst:; a nd
thunderstorm gust fron ts can be detected in situ by
measurement of either the surface wind or
micropressure or by a variety of remote sensin g
techniques. Surface wind records are often complex and
difficult to interpret and do not always provide a
reliable measure of wind shear conditions aloft. Since
solitary waves and thunderstorm ou tflow gust fron ts are
easily and reliably detected by sensitive
microbarometers , an array of the se relatively
inexpensive instruments in the neighbourhood of an
airport can be used to accurately monitor the progress
of coherent disturbances of this type over the terminal
area. Data from a suitable array of this type
supplemented by surface wind observations can be
analysed in real time to determine the nature of the
disturbance and to prov ide an effective 'wa rning for Air
Traffic C ontrollers of the onset and intensity of
propagating wind shear disturbances over the runway
area. The application of Doppler microwave radar to
quantitative wind measurements is the most promising
recent development for the accurate de tection and
pred_i~ti~m of low-altitude wind shear conditions. A h igh
sens1t1v1ty dual D oppler microwave radar installation in
the n~ighbourhood of an airport can provide a timely
warmng of the approach of propaga ting disturbances,
including clear-air disturbances, and appears to be
particularly well suited to the detection of the highly
localised wind shears in convective microbursts.
Another system which is b eing developed for remo te
wind sensing is the airborne or surface-based pulsed
Doppler radar. This system shows considerable
potential , particularly fo r the det ection of clea r -a ir
disturbances, and may prove to be a valuable
Parameter
Solitary wave
Propagation speed
U sually between 6 and 16 m/s;
may exceed 20 m/s•
Effective horizontal
scale of wind shear
disturbance
T ypically between 0.5- 6 km;
may exceed 10 km
Diameter typically 1-4 km
Gust front transition zone
typically 2-5 km
Effective vertical
scale
T ypically 1- 2 km; may
exceed 3 km
H orizontal vortex
circulation typically
1-2 km
Average ou tflow 'depth
0.4-0.6 km
H orizon tal winds
near surface
Usually between 5 and 12 m/s;
may exceed 15 m/s
Initial diverging outflow
typically 5-20 m/s; may
exceed 30 m/s
T ypically 10 m/s; m ay exceed
15 m/s
Down-draught
Typically 5 m/s; may
exceed 8 m /s
Typically 10 m/s; may
exceed 20 m/s
Effective time scale
ove r terminal area
U sually between 2 and
7 min . for individua l solitary
waves
2-20 min.
T ypically 2-1 0 min . (gust front
tra nsition zone)
R em arks
Long-lived disturbance ;
prop agates over great
dista nces; usually occurs as
clear -air disturbance
Ubiquitous feature of
convective sto rms;
short-lived , localised
disturbance
Usually active within 30 km of
thunderstorm source
•10 m/s is approximately 20 knots
8 I Aviation Safety Digest 123
An article in Aviation Safety Digest 119 drew attention
to the need to establish before flight a clear division
of respon sibilities wh en two pilots fly an aircraft
wh ich is normally operated single-pilot. As that
article poin ted out , ' P referably the pilot-in-command
should operate a single-pilot aircraft as its
manufacturer intended: by himself' . That advice
h olds good. At the same time, it is advice based on
the p remise that the two pilots have decided who
actu ally is the pilot-in-command. The failure to
resolve this q uestion was the basis of an incident
involving two p ilots with a total combined flight time
of 20 OOO hours.
T he flight notification for the trip in a light twin
indicated that Pilot A, who was undergoing an
instrument rat ing renewal test, was pilot-incommand. H owever, the testing officer, Pilot B ,
believed that he was pilot-in-command. No
d iscu ssion was held prior to the flight concerning
respective respon sibilities.
C o nsequently a degree of ambivalence about who
was doing what characterised the pre-flight
insp ection, wh ich was subsequently described as
being 'shared and unco-ordinated' . As often seems
to h a ppen in this type of occurrence, the attention of
component in an in tegrated low-altitude wind shear
monitoring system .
Table 1. Properties of solitary waves, convective microbursts and thunderstor m outflow gust fronts
Convective microhursl
Division of responsibility
Th understorm outflow gust front
T ypically 10-20 m/s
Conclusions
L a rge ampli tude solitary waves in the atmospheric
boundar y layer ar e a significant source of hazardous
low-altitude wind sh ear. These waves are a commonly
occurring feature in many areas of Australia and may
be encoun tered by aircraft as sudden unexpected cleara ir wind sh ear d isturbances. While the probability of
such an encoun ter is small, it is not insignificant.
Pilots an d A ir T raffic Controller s should become
fam iliar with the infl uence of solitary waves and other
low-altitude wind shear disturbances on the
p erformance of aircraft, particularly during landing and
takeoff.
H azardous low-altitude wind shear conditions can
develop rapidly over t he airport terminal area. Pilot
repor ts of win d shear difficulties can therefore be vitally
impor tant and should be relayed as rapidly as possible
to o ther incoming and outgoi_n g flights. Air Traffic
Controllers should b e aware that the detection of one
solitary wave disturbance m ay well be an indication of
both pilots also was diverted during the preflight.
T he upshot of all this was that the inspection was
incomplete and the pitot tu be cover was not
removed.
Because it was raining the pitot heater was
switch ed on before takeoff. T his was perhaps
fortuitous, as it caused the plastic cover to melt and
the airspeed indicator worked normally . However,
the red streamer attached to the cover alerted the
crew to the fact that something was wrong when,
shortly after lift-off, it started flapping against the
aircraft skin . Air T raffic Control was advised that
the aircraft was returning because of a flapping noise
associated with the airframe, and an Alert SAR Phase
was initiated. T he landing was completed without
incident.
Discussion
Operating an aircraft without an absolute
understanding of who is responsible for what offers
the potential for disaster. This incident also proved
- yet again - that aviation can be a real leveller
and is no respecter of experience or status if the
basics are not obser ved •
the onset of several identical wind squalls separated in
time by some 10- 20 minutes.
Further work needs to be undertaken to establish a
climatology for low-level wind shear in Australia and to
develop a completely reliable wind shear detection and
warning system for operational use at airports.
Acknowledgments
T his research was supported by the Air Force Office of
Scientific Research under Contract AFOSR-83-0045.
Further information on solitary wave wind shear may
be found in the following articles:
Christie, D. R. and Muirhea d, K. ]., 1983: Solitary
Waves: A Hazard to Aircraft Operat ing at Low
Altitudes. Aust. Met. Mag., 31, 97-109 .
Christie, D. R . and Muirhead, K. J. , 1983: Solitary
Waves: A Low-Level Wind Shear Hazard to Aviation.
lnternptional J. Aviation Safety, 1, 169-190.
R eprints of these papers are available upon request
from the au thors , R.S .E .S., A.N.U., G .P .O . Box 4,
Canberra, A .C.T. 2600 •
Aviation Safety Diges t 123 I 9
�Engine failure on takeoff
Pilots of multi-engine aircraft practise engine failures as
a matter of routine. Because the circumstances of such
practice are usually predictable - rating tests ,
endorsements and so on - pilots generally a re
prepared and handle the situations easily. Experience
has shown, however, that when a genuine - and
therefore unexpected - engine failure occurs the
pressures associated with the ' real thing' can cloud a
pilot's judgment. This is particularly so if the failure
occurs during a critical phase of flight.
*
*
*
During the takeoff roll, all engine indications on the
light twin were as advertised, with 43 inches of
manifold pressure and 2575 RPM each side and all
temperatures and pressures normal. Takeoff weight was
28 kg under the maximum . Acceleration was good and
the aircraft was rotated at 90 knots . The pilot held the
aircr aft level until 104 knots (best two-engine ra te-ofclimb speed) was reached and retracted the
undercarriage. Then, while accelerating to best singleengine rate-of-climb speed ( 109 knots), the pilot felt his
aircraft yaw slightly to the right.
As the aircraft yawed the pilot noticed the right-hand
m a nifold pressure drop from 43 inches to about 30
inches. RPM, fuel flo w, temperatures and pressures all
appeared normal . Initially, however, because they were
so close to the ground, the pilot was almost fully
occupied with flying the aeroplane.
When he was able to complete a trouble check, the
pilot confirmed with the 'dead -leg dead-engine '
technique that it was the righ t engine that had susta ined
a power loss. H e noted that there did not seem to be
much yaw and the force he had to apply to the rudder ·
seemed slight, while the engine note h ad not changed
and th ere was n o audible propeller desynchronisation.
The pilot also confirmed that the throttle was fully open
and that the undercarriage and flaps were retracted.
At abou t this stage the occupant of the right-hand
seat, who was a qualified pilot and was on this flight as
an observer , suggested to the pilot that the right en gine
had sustained a turbo-charger failure. Of his own
initiative the observer also checked that the a ux iliary
fuel pumps were on and the fuel selection s were correct.
The aircraft was now flying over water a nd was so
low that the pilot was reluctant to either try to turn or
to change the configl!ration, lest any d isturbance should
cause the aeroplane to impact the surface. H e asked the
observer to check the engine gauges again and also
raised the possibility of feathering the right propeller.
The observer replied that he thought the engine was
still developing som e power a nd that in his opinion they
should not feather. This diagnosis was accepted by the
pilot.
It is significant to note th at at about this t ime the
pilot asked the observer to help him hold the rudder
force countering the yaw towards the right engine, even
though he had in itially considered that force to be
slight.
A turn-back to the runway was not possible : it seems
. that it was only because of ground effect that th e light
10 I Aviation Safety Digest 123
twin stayed airborne, for each t ime a climb or sligh t
turn was attempted a irspeed would start to decrease and
the stall warning horn would blow.
T his dire situation was resolved when the pilot
sighted a beach which he was able to reach without
much manoeu vr ing and on wh ich he effected a safe
landing.
Before discussing the loss of engine power and the
pilot 's actions it is worth mentioning the general
emergen cy p rocedures taken.
Although a ditching could have been carried out, the
pilot wanted to avoid it if possible, as none of those on
board had lifejackets. He did , however, advise the
passengers of the predicament and got the obser ver to
brief them on ditching procedures over the PA system.
He also m a naged to declare an emergency over the
radio, get the transpon der selected t o code 7700 and
keep Air Traffic Control advised of his action s.
f
~
I
(
Incident analysis
Technical investigation showed that the right-ha nd
engine had in fact lost all power shortly after takeoff
because of magneto drive failure . Although the ignition
system was fi tted with du al m agnetos, those magnetos
sh ared a common drive system; thus, when it failed, all
ignition was lost. T here was nothing wrong with the
turbo-charger.
T here were two p ilots on the aircraft, albeit one was
an observer. Both had twin -engine exper ience yet
neither recognised that the right engine h ad failed;
con sequently th e ap propriate engine failure drill was
not carried out. Thus, the propeller was not feathered
but rath er was left windmilling (in the m istaken
impression that it was under power), in wh ich condition
the drag it created seriously degraded the aircraft's
single-en gine performance. Indeed, it was determined
that the aircraft sta bilised at a height of about 10 feet:
had it not been over water where it was possible to fully
utilise ground effect, a haza rdous crash lan ding would
probably have eventuated.
There are three aspects of the 'trouble checks' that
are worth examin ing in this incident, relating to:
• turbo-ch arging
• control forces
• en gine instruments
The pilot's reliance on th e observer 's assessment of the
problem also requires comment .
Turbo-charging. The purpose of a turbo-charger or
sup erch arger is to increase the mass airflow into an
in ternal combustion engine, thereby increasing its
power output. For example , in this case m anifold
pressure at takeoff was 43 inches , whereas with a
normall y aspirated engine (i.e. without turbo-charging),
m anifold pressure would have been close to ambient
pressure (about 27- 30 inches).
T he point here is that the failure of a tur bo-ch a rger
on a twin-en gine a ircraft sh ould not, on its own, affect
the performan ce such th a t the a ircr aft will lose height.
In general terms, even if its turbo-ch ar ger was
inop erat ive, the engine of th is aircraft should still ha ve
develop ed a bout 70 per cen t of its rated sea-level takeoff
power. Given t he a ircraft's loss of perfo rmance, this
clearly was not the case .
Control fo rces. As every twin-en gine p ilot knows, an
aircraft will yaw towards a failed engine. T o counter
this yaw opposite rudder must be applied: hence the
'dead-leg dead -engine' techniqu e of ident ifying which
engine has failed . The pilot used this t echnique but
commented that the left rudder force h e had t o apply to
counter the yaw seemed sligh t , which he took as a n
indication that the r ight engin e was still developing
power. H oweve r , as was m en tioned above in the
narrative of th e incident, he shortly afterwards asked
the observer to help him h old the rudder fo rces. As was
the case with the aircraft' s loss of p erformance, this
should have alerted the pilot to the fact that the right
engine had failed completely .
Exactly why th e pilot initially con sidered the rudder
forces to be light canno t be determined, bu t perhaps
with his adrena lin pumping he did n ot fully appreciate
the effort he was m aking.
Engin e instruments. One of the funda mentals of
piloting is the cross-check. For a suspected engine
failure this means, after com pleting the 'dead-leg dead engine ' identification , cross-r~ferral to the en gine
instruments to confirm th at iden tification. T his is very
important , for in the heat of the m om ent it is easy to
becom e confused. In this instance, with the throttle
fully open , the ma nifold pressure gauge would not have
been much u se as it could have indicated a m bient
pressure (about 27- 30 inches) for either a turbo-charger
fail ure or a complete loss of power. RPM , too, initially
would h ave remain ed n orm al, although a decay should
have subsequen tly occurred as a irspeed decreased.
The key engine instrument h ere was the cylinder
head temperature gauge (CHT) which was n ot ob se rved
by either pilot after their initial checks . If the en gine
had been d eveloping power, the CHT would have given
a norm al operating range reading . H owever , in a failed
engine which has n ot been shut down, the CHT will
drop rapidly, for , instead of burning, the fuel an d a ir
being pumped into the cylind ers will act as a coolant.
Oil temperatu re also will drop noticeably, although not
as quickly.
Pilot responsibility
The pilot had over 400 hours on type, including 25 in
the last 90 days. The observer, on the other hand, had
45 h ours on type; while th is flight was only his second
on type for over 2 years a nd his second on any type for
6 months . G iven these circumstances, the p ilot 's
acceptance of the observer's analysis of the problem can
only be questioned . I t does not seem un fair to suggest
tha t had the pilot had a thorough knowledge of h is
aircraft's systems and performance he would have h ad
the confidence to analyse the symptoms him self and
feather the r ight engin e, thereb y improvin g th e
aircraft's single-e ngine p erfo rmance.
I t also seems possible that under the stressful
circum stances the pilot' s atten tion became chann elised
on one aspect of the emergency which thus excluded
other importan t information (en gine ins trument
indications) from his attention. Frequent a nd thorough
tra ining provides the best cou nter to this problem •
Aviation Safety Digest 123 I 11
�Fatigue leads to confusion
At the end of a day's mustering activities a Hughes
269C helicopter and a Cessna 172 landed at a
waterbore so that the pilot and stockman/spotter from
the helicopter could board the Cessna to return to their
homestead: the helicopter was to be left at the bore
overnight. Last light was only 15 minutes a way, so the
engine of the Cessna was left running. After getting
into the Cessna, the h elicopter pilot and spotter
remembered th at they had left their water flasks near
the helicopter and hastily left the Cessna through the
right cabin door to retrieve them. The helicopter was
parked to the left of the C 17 2 (see diagram). The
helicopter pilot exited around the tail of the Cessna but
the stockman ducked under the strut and went forward
towards the propeller. At the last moment he saw the
sun reflecting off the propeller disc but it was too late.
Although he sidestepped he co uld not a void the rotating
blade and su stained serious injuries, including a badly
slashed left arm and severed arter y.
The C 1 72 pilot parked the brakes and ran to the
injured man. The helicopter pilot grabbed the first-aid
kit from the Hughes and pu t a tourniquet around the
spotter's upper arm. The spotter was then assisted back
to the Cl 72 and they departed for the homestead,
arriving at last light. There was insufficient fuel le ft in
the Cessna for a mercy flight to the nearest hospital , so
the Royal Flying Doctor Ser vice was called out to pick
up the injured man . First-aid information was relayed
over the radio .
and so that the pilot could see him. I t seem s that this
practice had become ingrained. He was also very tired ,
having started wor k at 5.30 a.m. each day for over a
week.
The pilot of the Cessna did not caution the h elicopter
pilot and spotter that the en gine was running when they
got o ut of the Cessna to retrieve their water flasks.
However , he knew that they were both familiar with
fixed-wing aircraft operation s, while he too was very
tired, having been engaged in cattle m ustering for
10 days.
Comment
It is well recognised that it can be d a ngerous to work
with m oving machinery when one is tired and 'switched
off'. Here, the Cessna pilot and the sp otter were
fatigued. In this state, the spotter reverted to h is
automatic action of the p ast two days and exited the
Cessna by the front, as he had been doing con sisten tly
with the helicopter.
The subject of fatigue a nd recognising its symp toms
has been given considerable exp osur e in recent editions
of the Aviation Safety Digest. Clearly it would be
unrealist ic to suggest that aircrew or LAMEs shou ld stop
work the instant their-per formance drops below the
optimum . By the same token, to allow oneself to
becom e fatigu ed to the stage where safety st andards are
compromised can be tantamount to dicing with death.
In this context , it is im portan t to remember that the
onset of fatigue, with all its atten dant dangers, is often
insidious.
Discussion
The spotter was used to working with fixed-wing
aircraft and knew th at he sh ould not go around the
nose of the Cessna because of the propeller. H owever,
for two days he h ad been entering a nd exiting the
helicopter from the front in o rder to a void the tail rotor
Aircraft accident reports
*
*
*
A secondary lesson to be learnt from this accident is the
value of first-a id training. T h e availability of a good
first-aid kit and the helicopter p ilot's ability to u se it
were instrumental in saving the spotter's life •
THIRD QUARTER 1984
The following information has been ext racted from accident data fi les maintained by the Bureau of
Air Safety Investigation. The inten t of publishi ng these report s is to make avai lable information on
Australian aircraft accidents from wh ich the reader can gain an awareness of the circumstances and
cond itions wh ich led to the occ urrence.
At the time of publi cation many of t he acc idents are stil l under investigation and the information
contained in those reports must be considered as pre liminary in nature and possibly subj ect to
amendment when t he invest igation is finalised.
Readers shou ld note that t he information is provided to promote aviatio n safety - in no case is it
intended to imply blame or liabil ity.
Note 1: Al I dates and times are local
Note 2: Injury classificat ion abbreviations
C =Crew
P = Passe ngers
0 = Others
N = Nil
F =Fatal
S =Serious
M =Mino r
e.g. C1S, P2M means 1 crew member received serious injury and 2 passengers received minor
injuries.
PRELIMINARY REPORTS (The fo llowing accident s are sti ll under invest igation)
Date
Time
04 Jui
1421
Aircraft type & registration
Loca tion
Piper 32-R300 VH-SBK
C harleville, Old.
Kind of flyipg
Departure point/Destination
Charter - cargo operat ions
Roma, Old./Windo rah, Old.
Jn;uries
Record number
C1N
841 1032
Dur ing cruise, the pi lot noticed t hat the electrical sys tem was malf unctionin g. The ammeter was read ing zero , the system was
switched off and a diversion for lan ding carried o ut. The: pilot reported that, on arrival in the ci rc uit area, the lan ding gear could
not be lowered by the emergency system. A wheels-up land ing was made.
04 Jui
1340
Piper 28-R201
Gympie, Old .
VH-RON
Non-com morcial - pleasu re
Maroochydore, Qld./Gym pie, Old.
C1 N , P1N
8411031
The pil ot was land ing i n gus ting wind condi tions with a cross-wind from the left. Af ter the left whee l had touched down and
before the righ t wheel had been grounded , a gust of wind lifted the left w ing, causing the aircraft to dri ft to the right. A ttemp ts by
the pil ot to re-land were un su ccessfu l and a go-arou nd was ini tiated. The aircraft subsequently col lided wi th a fence post and
came to rest abou t 180 metres off the side of the runway.
04 Jui
1220
Robinson R22 VH-UXM
Mildu ra, Vic. 11 ESE
Ferry
Swan Hi ll , Vic ./Mildura, Vic.
C1M, P1 S
843101 9
The ai rcraft departed Camden on the prev ious afternoon for a ferry f light to the Kununurra area w ith an overn ight stop near
Ei ld on , Vi c toria. About 35 kilometres f rom Mildura the pilot reported that he was land ing due to a vi bration . After inspec tin g t he
aircraft he con t inued wi th the fl ight bu t later made a brief Mayday cal l. Witnesses reported tha t the en gine was running in term itten tly before the heli copter landed heavily, tai l-down , i n a vineyard. Init ial i nves tiga tions have indicated that the incorrect grade of
fuel was bei ng used and that the f uel sy stem con tai ned a contaminant.
C1 N
Non-commercial-business
06 Jui
Piper 28-1 40 VH·TVJ
Coifs Harbour, NSW/Banks town, NSW
8421030
0258
Bankstown, NSW 4N
Abo ut 5 minut es after his es timated arrival ti me t he pilot reported that he was uncertain of his p os it ion. Attempt s to locate t he ai rcraft we re unsuccessfu l until the pilot c limbed to 6000 feet, an d 22 minut es after the ini tial call the aircraft was radar iden t if ied 78
ki lometres nort h of Sydney . The aircraft was vectored towards Banks town bu t abou t 9 kilometres from the aerodome the pilot advised that the aircraf t was out of f uel. A forced landing was carried out on to a suburban s treet, during wh ich power lines and a
power po le we re struck.
09 Jui
1553
Cessna R182 VH-UCN
Borro loola, NT
No n-commerc ial - pleasu re
Borro loola, NT/Doomadgee, Old.
C1 M, P1 M
8441020
As t he aircraft was climbi ng t hroug h 8000 feet the eng ine su ffered a complete los s of power. Aft er unsuccessfully attempting to
restore engine power, the pi lot selected a smal l c learing in which t o land . During the landin g attem pt , t he airc raft floated the 160
metre lengt h of the clearing befo re colliding w ith trees.
12 Jui
1545
Helicopter was parked at A, C172 at B, heading 350 as indicated by arrow.
12 I Aviation Safety Digest 123
Transav PL1 2 VH-BPR
T umbarumba, NSW 20 NW
Aerial agric ulture
Lower Bargo, NSW/Lower B'.lrgo, NSW
C1N
8421034
Superphosphate spreading o perat ions had been carried out throughout the day. Dur ing t he s ubject takeoff attempt the ai rcraft
began to pul l to t he left short ly after full power was ap pl ied. The pi lot abandoned t he takeoff and as he did so t he left main gear
co ll apsed. The ai rcraft ground looped and came to rest 70 metres from t he start of the takeoff roll. Invest igat ion revealed t hat t he
left mai n gear pivo t ing lugs had fractured.
Aviation Safety Digest 123 I i
�PRELIMINARY REPORTS (The fol lowi ng acc idents are stil l under investigat ion)
PRELIMINARY REPORTS (The fo ll ow ing acc idents are sti ll under investigation)
Da.te
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
17 Ju i
Mooney M20F VH-CGJ
Instructional-check
C2N
Narrabri, NSW/Narrabri, NSW
8421032
1705
Narrabri , NSW
The pilot was receiving a check flight as part of a bienn ial flight review. He was approp riately· endorsed for ret ractab le gear and
constant speed propeller aircraft, but had not previously flown the Mooney ty pe. After touchdown on the t hird of a series of
touch-and-go landings the pilot inadvertently raised the landing gear instead of t he flap. The aircraft sl id to a hal t on the runway.
22 Aug
Piper 32-300 VH-RPB
Non-commercial- pleasure
C1N, P1S, P1M, P1N
11 30
Skipton, Vic. 3S
Melbourne, Vic./Naracoorte, SA
8431023
While the aircraft was cru ising at 3000 feet t he engine RPM suddenly increased , coinciding with a loss of oi l pressure. The pilot
com menced a precautionary land ing sequence but after completing a satisfactory approach the ai rcraft made a heavy landing in a
cleared paddock.
Smith 600 VH-PWL
Instructional-check
27 Jui
C2N
1100
Deniliquin, NSW
Deniliquin , NSW/Deniliquin, NSW
8421035
The pilot was carrying out a practice single engine landing. The gear was lowered and th ree greens obtained, but as the
nosewheel contacted the runway the nosegear retracted. Inspection revealed that the drag link trunn ion block had failed allow ing
the drag brace to sl ip over centre and the nosegear to retract.
C1N , P1 N
Charter - cargo operations
23 Aug
Beech H18 VH -PDI
8421040
Bankstown, NSW/Canberra, ACT
1834
Bankstown, NSW
The airc raft ret urned to its departure aerod rome after suffering a complete elect rical failure. Emergency extension of the gear
was completed, but duri ng the land ing roll the nose leg ret racted, wh ich resu lted in the nose and propellers strik in g t he runway.
Non-commercial-pleasure
01 Aug
Robinson R22 VH-UXD
C1N
Brooklyn Station/Brooklyn Station
Brooklyn Station
8411033
1100
The pilot landed the helicopter to allow his passenger to alight. The engine was left running, the cyclic frictioned and col lective
held fully down. The pilot then felt a low frequency vibration begin and almost immediately the lef t side of the helicopter li fted
and the tail swung to the right. Control inputs by the pilot had no effect and the helicopter rolled onto its s ide.
05 Aug
Bell 206-B VH-F HB
Aerial mapping/photography/su rvey
C1S, P3S
Nth Ryde (Channel 10)/Nth Ryde (Chan nel 10) 8421036
1008
Sydney, NSW 9NE
The pilot brought the helicopter to a hover at 1000 feet agl, pointing approximately into wind. The aircraft began to yaw to the
right and the pilot was unable to stop the result ing rotation. The helicopter descended in a steep nose down attitude and struck
t he ground heavily while still rotating to the right. The landing skids were torn off and the helicopter came to rest on its left side.
.
Piper 25-235-A1 VH-BSB
Glider towing
C1F, 02F
05 Aug
Woodbury, Tas./Woodbury, Tas.
Woodbury, Tas.
8431 021
1543
At about 500 feet after a normal takeoff and turns to position the t wo aircraft on a downwind leg d irection, the tug aircraft gave a
signal requesti ng the glider to release from the t ow. The tug aircraft then assumed a steep nose-down attit ude, its tail being held
up by the glider. The glider then also adopted a steep nose-down attitude and both ai rcraft spiralled to t he ground. Both pilots
had initiated re lease from the tow cable but evidently at too late a stage to allow recovery to normal flight.
Instructional-dual
C2F, 0 1F
Czech Blanik VH-GGF
05 Aug
Woodbury, Tas./Woodbury, Tas.
8431021
Woodbury , Tas.
1543
At about 500 feet after a normal takeoff and turns to position the t wo aircraft on a downwind leg d irect ion, the tug ai rcraft gave a
signal requesting the glider to release from the t ow. The tug aircraft th en assumed a st eep nose-down attit ude, its tail being held
up by the glider. The glider then also adopted a steep nose-down attitude and both aircraft spiralled to the gound. Both pilots had
initiated release from the tow cable but evidently at too late a stage to allow recove ry to normal flight.
Non-corn rnercial - busi ness
C1N, P2N
Cessna 210L VH-EJC
07 Aug
Coolangatta, Qld./Sydney, NSW
8421037
1548
Bankstown, NSW
On arrival in the destination circuit area the pilot was unable to obtain a safe 'down and locked' ind icat ion for the landi ng gear. A
diversion to a more suitable aerodrome was carried out and after all efforts to lock the left main gear down were un successful, a
safe landing was mad e with all wheels retracted. Damage was confined to the propel ler blades and the under skin of the fuselage.
Aerial agriculture
C1N
Hiller UH12E VH-FBX
10 Aug
Blac k Springs, NSW 13SW
Blac k Springs, NSW/Black Springs, NSW
8421038
0945
The pi lot was cond ucting s praying operations over a lightly timbered paddock, flying at about 10 feet ag l and 50 knots airspeed .
During the seventh swath run the helicopter main rotor struck a branch of a tree. The rotor tip weight and fai ring were detached
and severe vibration developed. The pilot attempted to land straight ahead but the tai l rotor struck the ground and the helicopter
pitched forward and came to rest on its right side.
Robinson R22 VH-UXL
Instructional - dual
C2N
12 Aug
Castle Hill, NSW/Castle Hill, NSW
1528
Cast le Hill, NSW
8421039
At the conclusion of an exercise in the training area the instructor positioned the helicopter in a hover at about 3 feet agl and
allowed the studen t to .use the controls. The aircraft was headed into the 15 kn ot gusty w ind when sudden sink was experienced.
The student instinctively applied f ull aft cyclic control and the heel of the right skid dug into t he grou nd as t he hel icopter moved
backwards. The aircraft rolled onto its right side, destroying the main rotor blades and d istorting the cabin area.
Robinson R22 VH-IXM
Inst ruc tional- dual
18 Aug
C2N
Archerfield, Qld.
1005
Archerfi eld, Qld./Archerfield , Qld.
8411036
As the helicopt er was being hovered the pi lots heard a muffl ed bang. The instructor im mediately assumed contro l and landed the
heli copter. An inspection of the t ransmission area revealed that the rear drive belt was missing. The in structor reboarded the
helicopter and commenced to hover taxi back to the hangar. Another bang and other no ises we re heard emanating from the rear
of the helicopter, wh ich was again landed and the engine s hut down. Substan tial damage had been caused to t he transmission
area.
Airtract AT301 VH-IXL
Aerial ag ri culture
20 Aug
C1N
1645
Ingham, Qld . 1S
Ingham, Qld./lngham, Qld.
8411037
As the pi lot was manoeuvring the aircraft to commence another baiting run , the engine lost all power. The aircraft was landed in a
paddock of young sugar cane. After a ground ro ll of 90 metres the main whee ls d ug into the furrows across the paddock and the
aircraft nosed over. A fire broke out and eng ulfed the wreckage .
ii I Aviation Safety Digest 123
Cessna 172N VH-TEF
Non-commercial -pleasu re
C1N , P1M
23 Aug
Dooley Downs Si n., WA 4SW Dooley Downs Stn., WA/Mt Augustus Stn., WA 8451020
1600
At about 600 feet ag l after takeoff the eng ine stopped and attempt s to restart were unsuccess f ul. The pilot was then forced to
attempt a land ing on unsuitable terrain and during the landing roi l t he nose wheel and right main wheel were torn off.
C1N
23 Aug
Aerial agricu lture
Cessna A188B-A1 VH -EVV
8421049
Spicers Creek, NSW/Spicers Creek, NSW
1400
Spicers Creek, NSW
During a spray run whic h involved f light beneath a power line, the pilot lost sight of t he supporting poles and assumed he had
passed the cable. A pull up was init iated but the fin and rudder struck the cable, wh ich tore about 15 cm from both surfaces. The
airc raft remained control lable and a safe land ing was subsequen tly carried ou t.
C1N
Instructional -solo (supervised)
24 Aug
Piper 28-161 VH-PZQ
8421041
1300
Cessnock, NSW/Bankstown, NSW
Cessnoc k, NSW
Maintenance veh icles were parked on the grass area adjacent to the taxiway . The pilot was concentrating on keep ing the aircraft
moving down the taxiway centre- line when the left wing struck a t ractor. The aircraft slewed to t he left and co lli ded with a ut ility
wh ich was parked behi nd t he tractor.
C1F
Non-commerc ial - pleasu re
24 Aug
Cessa 1820 VH -CKJ
Bankstown, NSW/Cooma, NSW
8421042
1905
Cooma, NSW 5S
Afte r completing an instrument f light at night, the pilot reported his arrival in the circu it area of t he desti nation aerod rome. The
aircraft did not land and a search was commenced. The bu rnt out w reckage was located the fol low ing morn ing.
C1F, 01S
26 Aug
Sch neider ESKA6 VH-GQK Non-commercial - pleasure
8451021
Cunderdin, WA/Cunderd in, WA
1330
Cunderdin, WA
Wh ile being towed to the planned launch height , the g lider under tow and anot her glider in the ci rcu it area collided. The col lision
caused t he t ow rope to break and the pi lot o f the glider, although injured, was ab le to land his aircraft. The tailplane of the other
glider separated in the co llision and the aircraft descended uncont rolled into the ground . The tug aircraft was undamaged and
landed safely.
C1N , 01F, 01S
26 Aug
De Hav C1 A1 VH-RJK
Non-commercial - pleasu re
1333
Cunderdin, WA
Cunderd in, WA/Cunderd in , WA
8451021
Whil e being towed to the plan ned lau nch heigh t, the g lider under tow and another glider in the circu it area collided. The col lision
caused the tow rope to break and the pilot of the glider, although inj ured, was ab le to land his aircraft. The tailplane of the other
glider separated in the col lision and the ai rcraft descended uncontrolled int o t he ground . The tug aircraft was undamaged and
landed safe ly.
C1S, 01F
Non -com mercial - pleasu re
26 Aug
Czech Blanik VH-WUT
Cunderdin, WA/Cunde rd in, WA
8451021
1333
Cunderdin, WA
Wh ile being towed to the planned launch heig ht, the g lider under tow and another glider in the c ircu it area collided. The co llisio n
caused the tow rope to break and the pi lot of the glider, although injured, was able to land his ai rcraft. The tail plane o f the other
g lider separated in the collision and the aircraft descended uncontrol led into t he ground. The tug aircraft was undamaged and
landed safely.
31 Aug
0830
Pi per 32-300 VH -CST
Leaghur, Vic .
Non -commercial-pleasu re
Essendon , Vic./Broken Hill, NSW
C1N, P5N
8431024
Whi le cru ising at 3000 feet, fumes were noticed in the cabin and the engine began running rough. An explosion then occu rred in
the eng in e compartment , deforming the right side of the eng ine cow l. The pilot made an emergency land ing in a paddock;
however, the ai rcraft touched down heavily, co llapsing the righ t main gear, and after s liding for some distance the nose gear also
col lapsed. The centre right cylinder was observed to have detached from the eng ine bloc k.
C2N
Instructional - dual
Beech 76 VH-MFS
01 Sep
8431025
Melbourne, Vic./Moorabbin, Vic.
Bendigo, Vic. 12SSE
1320
Durin g cruise the right engine began to surge and vibrate. Normal actions to restore engine performance were unsuccessfu l and
the eng ine was shut down. About four minutes later the left eng ine lost power in a s imilar manner to t he right. The pilot carried
out a forced land ing and the nose wheel was torn off when it struck a ditch.
01 Sep
0815
Hiller UH1 2E VH-CCU
Boorowa, NSW 9SW
Aerial ag ricu lture
C1M
Corcoran Ptains, NSW/Corcoran Plains, NSW 8421044
Wh ile manoeuvring to commence a c lean-up spray run paralle l to a power line, the hel icopt er col lided w it h a spu r line. A broke n
secti on of the cab le struck and severed the tail boom, con t rol was lost and t he aircraft struck t he ground 150 metres beyond t he
spu r line.
Aviation Safety Digest 123 I iii
�PRELIMINARY REPORTS (The foll owing accidents are sti ll under investigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
lniuries
Record number
PRELIMINARY REPORTS (The fol lo wing accidents are st ill under invest igation)
Date
Time
Aircraft type & regis tration
Location
Kind of flying
Departure point/Des tination
lniuries
Record number
01 Sep
Piper 25·235A1 VH -MYE
Glider towing
C1F, P1F
Korumburra, Vic./Korumbu rra, Vic.
1533
Leongatha, Vic. 2N
8431026
The aircraft was returning to the strip following release of a glider. On right down w ind, at about 1500 feet agl, t he airc raft ban ked
steeply, then entered a spin. At abou t 800 feet agl spin recovery appeared to be effected but the airc raft then entered a spin in the
opposite d irection and subsequently struck the ground.
Activities assoc iated with aerial ag riculture C1 N
Piper 25·235 VH· KLZ
Warwic k, Old ./Wyag ra Ag. Strip , Old.
8411039
Goondiwindi, Old . 50N E
After conduct ing a rout ine strip inspection, t he pi lot was concern ed about the height of the wheat on eac h side and' commenced
another inspect ion f ro m about ten feet ag l. During the inspection t he aircraft descended almost to ground level, with its right
wing low, as a resu lt of the strong , gusting w ind. The rig ht spray boom contacted the wheat and the aircraft yawed right. As
ground c ontact was inevi table the pilot closed the throttle and attempted to correct the yaw but th e main whee ls and left wing
contacted the g round causi ng t he airc raft to s lew throug h 180 degrees before com ing to rest.
04 Sep
Piper PA38-112 VH-HAV
Instructional - solo (supervised)
C1N
Bankstown, NSW/Bankstown, NSW
1037
Bankstown , NSW
8421045
Following a period of dual instruction the pilot was authorised to carry out her second solo c ircuit and land ing. Du ring the land ing
flare the aircraft ballooned and subsequently touched down on the nose wheel. The aircraft boun ced and on t he next touchdown
the nose wheel broke off, the nose gear leg was displaced and the aircraft slid to a halt on the runway .
20 Sep
1743
05 Sep
1300
Cessna 210N VH-FOK
Go Go Stat ion , WA
Non-commercial-business
Go Go Station, WA/Go Go Station , WA
C1N, P2N
8451022
The pilot se lected a 340 metre long taxiway as the takeoff path. After a ground ro·11of about 250 metres, at an ind icated airspeed of
approximately 55 knots, the pilot rotated the aircraft but it did not become airborne. He then _closed t he t hrottle and the airc raft
ran off the end of the taxiway and col lided with several trees.
06 Sep
Cessna A188B-A 1 VH-UJR
Aerial agriculture
C1N
1515
lllabo, NSW 5E
lllabo, NSW 3NE/lllabo, NSW 3NE
8421046
The particular spraying run crossed a group of trees at the top of a rise. As the pilot pulled up to overtly the trees, t he rig ht wing of
the aircraft struck some branches. The pilot noticed fluid escaping from the tears in the win g and elected to c arry out an
immediate landing on the downslope beyond the trees. Shortly after touc hdown the aircraft yawed, the left w Reel dug in and t he
aircraft rolled over twice before com ing to rest inverted.
Commercial-aerial mustering
Robinson R22 VH-UXK
C1S
07 Sep
Mt Farq uhar, WA/Mt Farquhar, WA
8451023
Mt Farquhar, WA 12NNW
1800
The pilot was flying t he helicopter along a ridge line, checking a gully for cattle, when the engine suffered a substantial loss of
power. The pil ot init iated an autorot ational descent as the engine tailed completely. The helicopter landed heavily in the base of
the gully.
C1N, P1N
Robinson R22 VH·IPC
Non-commercial - pleasure
09 Sep
Gidgegannup, WA/Jandakot, WA
8451024
1630
Gidgegann up, WA
The pi lot was operati ng in a con trol zone but was unable to communicate w ith the con trolling agenc y whi le t he hel icopter was on
the ground. He carri ed out a takeoff and again, whi le hovering at 200 feet agl, attempted to communi cate w ith the cont rol agency.
Still unable to make contact, the pilot let go of the collective pitch lever, on wh ich t he friction was not applied, to change radio
frequencies . The helicopter entered a descending turn and the pilot was unable to regai n control before it st ruck the grou nd.
Non-commercial - business
C1N
Reims R172E V H-REV
12 Sep
Polpah Stn., NSW/Goodwood Stn., NSW
8421048
Goodwood Stn., NSW 9NW
0750
The pi lot was conducting an ins pection of bore tanks . The fuel selector was in the 'sor H' position when the eng ine sudden ly
failed. The pilot was fo rced to land on unsuitable terrain and the airc raft suffered damag e to the main landing gear su ppo rt area.
Non-commercial -p leasure
C1N , P4N
Cessna 172N VH-POS
12 Sep
Gove, NT
Gove, NT/Gove, NT
8441021
1536
The pilot commenced an approach to land after a preceding Fokker F28 had cleared the runway. Duri ng t he landing flare, severe
buffeting was encountered and the aircraft subsequently landed heavily, with resultant damage to bot h wing s, the forward
f uselage, landin g gear and the pro pel ler. The wind at the time of the occurrence was gust ing from 5 to 14 kt with a cross-wind
component of up to 7 kt.
Charter-passenger operations
C1 M, P1 M, P2N
12 Sep
Be ll 47·J2A VH-T HH
Mataranka HS., NT/Mataranka HS., NT
8441022
Mataranka Homestead, NT
1650
A ten minute flight in the local area had been complet ed without incident. After depart ure for a second f light, t he helicopter was
cli mbed to 150 feet agl to allow the passengers to view the campsite and a herd of animals. The pil ot and passengers then heard a
loud bang which was followed by a severe airframe vibration. The noise and vibration continued and the pi lot elected to carry ou t
an autorotational descent and land in a small c learing . The clearing was overshot and the helicopter struc k several t rees.
15 Sep
Cessna 150E VH-KMJ
Non-commercial-pleasure
C1N, P1N
Reekara, Tas .
Reekara, Tas./Reekara, Tas.
11 57
8431027
The pilot had decided to carry out some cross-w ind c ircuit pract ice aft er the other pilot on board had carried out circuits on t he
into-w ind st rip. On the first circ uit, touchdown was made 357 metres into the stri p on t he nose wheel and left main wheel
together, followed by the right wheel. The nose gear sustained damage and when the aircraft touched down again after a short
bounce, the propeller struck the ground.
Cessna U206F VH·WT J
Chart er- passenger operation s
C1N , P3M, P2N
16 Sep
Bungle Bungle, WA
Kununurra, WA/Kununurra, WA
8451 025
0725
When the pi lot applied c limb power a loud bang was heard , fo llowed by severe vibration and a loss of power. The pil ot se lected
the most suitable area of th e rough terrain to attempt a landing. During th e landi ng the aircraft struck several trees, the nose
wheel was t orn off and the ai rc raft nosed over. Inspection of the ai rcraft revealed that one of the prope ller blades had separated in
fli-ght.
iv I Aviation Safety Digest 123
18 Sep
1010
Cessna 210M VH-MG I
Tocumwal, NSW
Inst ructional -dual
Tocu mwal, NSW/Tocumwal, NSW
C2N
8421050
On downwind after the first takeoff fol lowi ng a sc hedu led servic ing, t he pilots were unable to fully extend the landing gear. After
all efforts to lower t he gear by normal and emergency method s were unsuccessful, t he pilot in command carried o ut a safe
land ing with the gear retracted.
22 Sep
1620
Ro lladen LS4 VH-GXP
Kingaroy , Old. 20SW
Non-commercial -pl easure
Kingaroy, Old./Kingaroy, Old .
C1M
841 1040
Towards the end of the f light an out land ing became unavoidable. A paddock with a number of trees and a power line at its edge
was selected. During the f inal approach, after cl earing tho se obstac les, th e g lider contacted an other wire running d iagonally
across the paddock. The w ire hooked under the w ing and the glider slid sideways along the wire for some distance before t he
ri ght win g struck a tree and the aircraft fell to the gro und.
24 Sep
1610
Cessna 172M VH-WYK
Burleigh Station
Commercial- aerial mustering
Burleigh Station/Burleigh Station
24 Sep
1040
Wittman W8 VH-MGO
Mung linup, WA 7E
Non-commercial - pleasure
Northam, W A/Munglinup, WA 7E
C1F
8411041
The pi lot was conducting mustering operations, operat ing between 50 and 300 ft ag l. A ll turns and cl imbs were being conducted
at normal angles. A witness to the accident saw t he airc raft suddenly execute a steep pull-up, appear to stop in the air, t hen dive
steeply towards some trees. The aircraft st ruck the ground in a steep nose-down attit ude, bounced and sl id for 23 metres before
the left wing struck a large t ree.
C1 N, P1N
8451026
The aircraft touched down in a t hree-point attitude and after a short roll became airborne over a smal l rise. The second touchdown
was in a left w ing low attitude and the prope ller struck the ground. The aircraft sw ung to t he right, t hen the left wing struck the
gro und tu rn ing the ai rcraft to the left. It slid a s hort distance before com ing to rest with the left gear leg collapsed.
26 Sep
1120
Hiller UH1 2E VH·ECK
Galong , NSW 4NE
Aerial agriculture
Bobbara Stn ., NSW/Bo bbara St n., NSW
C1N
8421051
Towards t he end o f a spraying run t he pilot noticed that the aircraft was d rift ing towards a power line runn ing rough ly paral lel to
the ai rc raft track. He attempted to counter the drift but the aircraft moved underneath the wi re. The main rotor struck the line as
the pilot attempted to manoeuvre c lear and also avoid trees at the end of the spraying run. After striking the w ire the helicopter
swung t hrough 180 degrees and the tail boom collided with a tree.
28 Sep
0922
Cess na 182A VH·CJC
Dalby, Old. 40S
Sport p'chuting (not associated with airshow) C1 M
Nangwee, Old./Nangwee, Old.
8411042
After releas ing a group of parachutists from 10 OOO feet the pilot commenced descent. Carburettor heat was applied unt il t he
aircraft was posi ti oned on a long left downwind for the selected strip. Shortly after engine power was f urther reduced and
carbu rettor heat was se lected to off, the pi lot reali sed that the engi ne had fai led. He turned o nto a right base leg and manoeuvred
t he aircraft in ord er to land downwin d on the strip. The aircraf t stal led j ust prior to touchdown and came to rest inverted.
29 Sep
1620
Cessna 21 0N VH·ADI
Beverley, WA 3W
Ai r show/ai r racing/air trials
Narrogin, WA/Jandakot, WA
29 Sep
1045
Cessna A1 88B·A1
Coreen, Old.
Aerial ag ricu lture
Coreen, Old./Coreen , Old.
C1 N, P5N
8451027
Pri or to the f irst flight on the day, the pilot inspected the f uel tanks of the airc raft and estimated they contained 200 litres of f uel.
On that bas is he plann ed a flight of 155 minutes d uration . Approach ing the second last turning po int of the flight the eng ine
stopped. The pilot selected the other f uel tank, power was restored and a diversion made to t he nearest suitable airfield. On f inal
app roach to that airf ield t he engin e stopped again. The ai rcraft was landed heavily in a paddock and the nose gear leg torn off.
VH-EVU
C1N
8411043
The strip be ing used was aligned south -east and the wind of 15 kt was swing ing from south -east to south-west. On the second
takeoff for the day acceleration was sl uggish and the pilot kept the main wheels in contact w ith the strip surface tor lon ger than
normal befo re allow ing the aircraft to become airborne . Shortly after liftoff the ai rcraft mushed and the wheels contacted t he
ground . The pilot abandoned the takeot t attempt and the aircraft came to rest 240 metres beyond the end of t he strip after
sustainin g damage to the left wing and landing gear.
30 Sep
1355
Pitts S2·A VH·SZA
Berw ick, Vic.
Non-commercial -pleasure
Berwick, Vic ./Berwick, Vic.
C1N
8431 028
The pilot reported t hat he commenced the takeoff w ith t he cont ro l stick fu lly back and some right rudder app lied. As the aircraft
ro lled it veered left until the left whee l encountered long grass on the side of the gravel strip. The aircraft tail, which was in th e air
when the grass was encountered, continued to rise until the prope ller struck the ground and the aircraft came to rest inverted.
Aviation Safe ty Digest 123 I v
�l
FINAL REPORTS (The investigation of the foll owing accidents has been completed)
Date
Time
Pilot licence
Charter-passenge r operations
C1 N, P1 N
03 Jui
DH-82A VH-WAP
1240
Surfers Gardens
Surfers Gardens/Surfers Gardens
8411030
3363
2536
Instrument rating class 4
Commercial
56
As the pilot approached the c ircuit area he noticed a squall line approach ing the strip. Whi le the aircraft was tax iing along the
flight stri p after lan ding the wi nd suddenly swung at right angles to the strip and gusted to 30 kt. The pilot attempted to t urn into
wind but before he could effect this the left wing lifted . The aircraft was then swu ng downwind and overturned.
17 Jui
1132
Commercial
Cessna 401A VH-RZY
Bankstown , NSW
33
Charter-passe nger operat ions
C1 N, P4N
Orange, NSW/West Wyalong, NSW
8421031
3610
2000
Inst rument rat ing 1st class
or c lass 1
On arrival at the planned destination, the pilot was unable to ob tain a down and locked ind icat ion fo r the nose landing gear. A
diversion was carried out to a more su itable aerodrome and during the landing roll the nose gear collapsed.
Investigation revealed that the nose to rque l ube mounting bracket assembly and su pport brac ket had failed because of fat igue
cracki ng. This had resulted in ineffective cranking action by the nose gear operating system.
24 Jui
0955
Commercial
Brit nor 2-A20
Wilton , NSW
VH-IGT
25
Aircraft type & registration
Location
Age
Kind of flyin g
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Record
number
C1N, P1 N
15 Aug
Hiller UH1 2-E VH-FFE
Commercial-aerial mustering
1530
Bowen Downs, Old.
Bowen Downs, Q ld ./Bowen Downs, Old.
841'1035
Commercial - helicopter
33
1250
1250
None
While in a low hover the pilot noticed several beasts moving towards the rear of t he helicopter. He moved the helicopter
rearwards and when he realised the tai l rotor was c lose to the ground, he applied power in an attempt to gain height. The tail rotor
struck the ground and the helicopter spun through 270 degrees before landing heavily.
The operation was being conducted over flat, grassed t errain. The pilot had only recent ly recommenced flying after a nine month
absence and he therefore had no recent experience in low level operations.
C1N
Instructional -solo (supervised)
21 Aug
Cessna 180K VH-SAA
Rockhampton, Qld ./Clermont, Old.
8411038
1110
Clermont, Old.
86
24
None
Private restricted
38
The pilot was on a solo navex wh ich included a land ing away from his training aerodrome. After a normal approach and
touchdown the ai rcraft groundlooped to the right when t he tai lwheel contacted the runway. The left gear collapsed and the
propeller, tai lplane and left wingtip struck t he ground. The aircraft was f itted with a lockab le tailwheel bu t the pilot had not been
instructed in its use for landing or takeoff.
Sport p'chuting (not associated with airshow) C3N, 0 1F
Wilton, NSW/Wilton , NSW
8421033
490
200
None
The aerodrome caretaker had been requested to inflate a tyre on one of the operator's airc raft. The engines o f VH-IGT were
operati ng when the pilot observed the caretaker approaching, carryi ng a battery wh ich powered an air pum p. The caretaker
walked around the tail of the aircraft, placed the battery near the right wheel, moved to the wingtip, and proceeded towards
another aircraft. He then realised he had taken the battery to the wrong aircraft and returned, walking directly towards the right
eng ine. The pilot attempted to shutdown the engines but the caretaker continued forward and was struck by the rotating
propeller.
29 Jui
Beech D55 VH-FEO
Non·commercial-business
C1N, P2N
1700
Prescott Lake, WA 16NE
Derby, WA/Prescott Lake, WA
8451018
Private
38
1000
500
Instrument rating c lass 4
The strip had been prepared by grading an area among sand dunes and the pilot had landed t he aircraft there on t hree previous
occasions. During the landing roll the right main wheel broke through the surface c ru st of the st rip. As the pilot attempted to
correct the ensui ng swi ng, the left main wheel also broke through the surface and the nose whee l collapsed as it was dragged
sideways through the sand.
Although the pilot had previou sly tested the suitability of the strip surface, us ing t he method outlined in the Visual Flight Guide,
the nature of the su rface and subseq uent usage had caused a soft spot to develop.
C1 N
Instructional - solo (supervised)
Cessna 150G VH-RXL
04 Aug
8431020
Berwick, Vic./Berwick, Vic.
1020
Berwick, Vic.
14
14
None
56
Student
The st udent had completed five dual circuits and was then authori sed to carry out two solo circuits and land ings. Du ring the
second approach some turbulence was encountered and a hard landing was made. The airc raf t ballooned to 5 metres and
groundlooped on the subsequent touchdown. After the aircraft had turned throug h 180 degrees its left wingt ip sc raped the
ground and it nosed over.
After the heavy touchdown the st udent had held excessive back pressure to keep t he nose wheel off the ground. A wind gust
caused the aircraft to become airborne and the pilot was unable to effect timely recove ry ac tion.
Commercial - aerial mustering
C1N
Cessna 172M VH-WXX
09 Aug
Fairfield H'stead, WA/Fairfield H'stead, WA 8451019
Fairfield H'stead, WA 19NE
0815
8360
8360
None
45
Commercial
While conducting aerial mustering in a small valley the aircraft struck a tree. The pi lot conducted a control check whi ch revealed
no abnormal operation. He then elec ted to retu rn to Fai rfield airstrip where he landed safely. A ground inspection revealed
damage to the right tailplane.
Charter-passenger operations
C1 N
Shepparton, Vic./Tocumwal, NSW
8431022
2100
230
Instru ment rating 1st class
26
or class 1 with instru ment
rating
The airc raft was taxied in the early dawn light with an overcast sky and drizzle. The aerod rome pilot-activated lights were not on
nor were the aircraft landing and taxi lights. The aircraft was inadvertent ly taxied off the taxiway. During attempts t o ret urn to the
taxiway the nose wheel of the aircraft entered soft ground and was broken off.
09 Aug
0646
Commercial
Beech 95-C55 VH-WSW
Shepparton, Vic.
11 Aug
Piper 32-300 VH-BMH
Non-commerc ial - pleasure
C1 N, P5N
1052
Morni ngton Island
Mt Isa, Old./Morni ngton Island
8411034
Private
50
167
4
None
The pilot was landing into a gusting 30 knot headwind. During the ground roll a strong crosswind component suddenly developed
and the aircraft slewed at right angles to the runway. The pil ot was unable to fully regain di rect ional control. The ai rcraf t ran off
. the runway and encountered a drain, causing the nose gear to collapse and the propeller to strike the ground.
vi I Aviation Safe ty Digest 123
Aviation Safety Digest 123 I vii
�FINAL UPDATES (The investigation of the fo l lowing accidents has been completed. The information is
additional to or rep laces that previously printed in the prelimi nary report)
Date
Time
20 Jan 83
Jastreb Cirrus VTC 75 VH-COO
Glider
8321010
1556
Tocumwal , NSW
60
74
Unknown
Glider
The pilot was carrying out his first flight in the type of glider. The aircraft was observed to enter a spin, at a low height, at the start
of the downwind leg. The aircraft struck the ground while turning to the right.
The pi lot had probably applied excessive control movements when encou ntering an unexpected thermal. His spin recovery
technique was not in accordance w ith that recommended and would have resulted in a substantial loss of height before recovery
cou ld have been effected. The aircraft had partially recovered to a spiral dive at the time of ground impact.
29 Jui 83
Bell 206-B VH-CEC
Commercial Wickham Heliport
9800
2500
1550
39
The helicopter had been parked adjacent to a refuelling platform 60 mm high . As the pilot
prior to takeoff, the right skid contacted the platform. The pilot attempted to correct with
right and came to rest on its right side near the platform.
helicopter
8321059
Instrument rating class 4
was bringing the aircraft to the hover
cycl ic but the helicopter rol led to the
The contac t between the right skid and the edge of the platform had induced dynam ic rol lover. The pi lot evidently had not
identified the problem in time to take the appropriate correcti ve action o f loweri ng the col lective control in order to place both
skids o n the ground.
8321097
Glider
Burkhart Ast ir CS VH-WV I
Glider
600
Rich mond, NSW
39
1800
1310
The pilot stated that the glider became high on final approach after encountering lift. He extended the air braktJS and side-slipped
steeply, then levelled the wings. The glider continued to descend and struck the ground 150 metres short of the normal
touchdown area.
Recovery from the high rate of descent was not initiated at a suffic ient height to perm it a proper flare for the landing.
17 Dec 83
12 Jan 84
Robinson R22 VH-UXK
Private - helicopter
8451001
1630
Curbur Station, WA 45NW
27
2100
2050
None
During hover taxi to a refuelling point the collective lever jammed. As the pilot attempted to free the lever, he allowed the
helicopter to rotate and the tail rotor st ruck a tree. A normal landing was made when the collective lever was freed.
The collective control had jammed because the spherical bearing around which the swashp late tilts had become misaligned.
While the cause of the misalignment cou ld not be positively determined, it is likely that a build-up of aluminium oxide grease on
the spherical bearing caused a c hange in the bearing preload. This may have in turn allowed the spherical bearing to become
mi saligned.
Commercial
8451003
20 Jan 84
Beech A36 VH-FEL
1290
Instrument rating class 4
49
13900
Bunbury, WA
1740
After about 80 metres of ground roll following a normal touchdown the nose began to drop, fo llowed by the right and left wings,
and the airc raft s lid to a halt w ith the gear retracted.
No mechanical fault or defect was s ubsequently found with the aircraft. The weight of available evidence ind icated that the pi lot
had probably inadvertently selected the gear up shortly after touchdown.
Glider
8431003
Schneider ES60 VH-GOH
04 Feb 84
Unknown
Latrobe Valley 1ENE
57
60
None
1450
After release from an aerotow launch at 2000 ft , the pilot detected significant sink. Attempts to find lift were unsuccessfu l and
judging he would be unable to return to the strip the pilot elected to make an out landing. The aircraft co llided with a tree during
the approach into the selected area and subsequently struck the ground heavily. Witnesses report ed that the airbrakes were
extended from the time of release from the aerotow.
The pilot had li ttle experience in the aircraft type. He had inadvertently deployed the airbrakes when attempting to adjust the trim
after tow release. Contro l positions and operating feel were different from the controls o f other glider types the pilot had flown
recently.
8411004
Glider
Burkhart Astir CS VH-GDS
05 Feb 84
40
Glider
Maryvale, Old. 7E
27
521
1305
The pilot elected to do an out land ing and selected a paddock which had a power line running east-west on its southern side. An
approach was made into the paddock o n a westerly heading but t he glider struck another power line running at a right angle to the
one noticed by the pilot.
The pilot had not seen the power line runn ing across the approach path w hen he selected the paddock for an o utlanding. The
sighting of the line was made difficu lt by a background of high terrain and the power po les being obscured by trees.
Student
8421006
Piper 28-1 40 VH-CNS
08 Feb 84
37
25
25
None
Cessnock, NSW
0810
Having completed hi s first solo the previous day, the pilot was given a dual c heck and authorised to carry out five solo circuits.
The fi rst landin g was reported as normal; however, on the second the pilot carried o ut a go-around after the aircraft bounced to
about 30 ft. Aft er a s light bounce on the next landing a go-around was carried o ut and the aircraft adopt ed a nose-up attitude and
turned left. The left wing struck a fence before the aircraft was land ed in a field.
viii I A viation Safety Digest 123
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type Rating
Record
number
18 Feb 84
Cessna 150M VH-BFA
Private
8441004
1651
Parafield, SA 2NE
30
601
10
Instrument rating 1st class or class 1
The pilot departed Toowoomba early on the same day to ferry the aircraft via refuelling stops at Walgett and Gri ffith. The flight
evidently proceeded normally until the aircraft was on approach to land at Parafield. At this time the pi lot advised that the eng ine
was failing and short ly afterwards he reported that he was experiencing fuel prob lems and would attempt a forced landing.
Control of the ai rcraft was subsequently lost and it crashed inverted into a suburban property.
Inspection of t he wreckage revealed that t he engine had failed through fuel exhaustion. Fuel usage on the previous legs of the
flight should have indicated to the pilot that the aircraft cou ld not reach the destination w ith the mandatory f uel reserves. The
pilot was known to be in a hurry to make an onward transport connection from Adelaide and he possibly allowed th is to influence
his decision to attempt the fl ight non-stop from Griffith.
When the engine failed the aircraft was about 800 feet ag l and t here were no suitable forced landing areas with in gliding d istance.
Control of the aircraft was then lost at too low a height to enable recovery before impact with the ground.
21 Feb 84
Piper 32-300 VH-MVT
Private restricted
8441005
2005
Aldinga, SA
11
None
37
57
After returning from a flight in the local training area, the pi lot went around from an approach which was too high. On the second
approach, touchdown occurred about half-way along the 820 m strip. The aircraft started to skid under heavy braking and the pi lot
considered that the aircraft might overrun the strip into a gully. Power was applied and although the aircraft became airborne at
t he strip end it then descended and collided with the far bank of the gully.
The pilot had limited experience on type and had encountered turbulence on final approach. The aircraft probably touched down
at a higher than recommended speed. It became airborne at the end of the strip at a low airspeed and subsequently stalled.
26 Feb 84
1600
Beech V35 VH·CFK
Binjou r, Old.
29
170
Private
120
8411008
None
The pilot had not flown fo r some time and was practising c ircu its with her husband who was also a pi lot. On downwind, her prelanding checks were interrupted by a rad io call. The aircraft was subsequently landed with the gear retracted. The gear warn ing
horn was not serviceable prior to the f light.
After the aircraft was established on final, the pilot's husband commenced to stow t he headsets and other loose items w hich
were in the cockpit. He d id not mon itor the approach and therefore did not notice th at the pi lot had omitted to lower the lan ding
gear.
11 Mar 84
1345
Hiller UH1 2E VH-FBO
Casino, NSW 15S
43
6700
Commercial - helicopter
3000
Agricultural class 1
8421010
The helicopter was climbing through a height of about 30 ft when the pilot heard a loud snapping noi se. This was followed by
temporary loss of contro l and severe vibration. The pilot retained sufficient control of the aircraft to carry out a forced landin g at
about 10 kt ground speed.
The main rotor tension/torsion pin had failed through the eye end due to fatigue which had originated from corrosion pitting. The
pin had evidently not been inspected at the intervals required by the approved maintenance schedules.
13 Mar 84
Cessna 1820 VH-EIL
Commercial
8431006
0845
Taggerty, Vic . 5SSW
20
320
80
I.A. class 4 w ith f light instructor
The pilot carried out a st raight-in approach to the 760 metre long grass strip. Rain was falli ng at the time. The aircraft touched
down about 200 metres beyond the threshold and the pi lot reported that t he brakes seemed ineffective. After overrunning the
strip the aircraft overturned when it entered a ditch .
No fau lt was subsequently found with the braking system. It was possible that the ai rcraft was subjected to a tailwind gust at the
time of touchdown. Although he was concerned at the lack of braking effectiveness, the pilot considered that the aircraft would
stop in the remaining distance and he elected not to carry out a go-around.
14 Mar 84
Mooney M20J VH-MIY
Private
8411013
0945
Great Keppel Island
67
627
245
Instrument rat ing class 4
Shortly after takeoff, t he pilot heard a loud noise and noticed that the luggage locker door was open. A 180 degree t urn was
carried out for an approach to the departure runway. As the ai rcraft approached the end of the runway the right wing struck the
ground and the aircraft slid sideways along the runway. All the landing gear legs collapsed before the aircraft came to rest.
On short fi nal, mechanical turbu lence had been encountered and a high rate of descent had developed. A lthough some action to
correct th is rate of descent was taken, the pilot was unable to avoid a hard land ing. No fau lt cou ld subsequently be found wit h the
luggage door securing mechanism.
22 Mar 84
2019
Beech 35-C33 VH -CEA
Essendon, Vic.
28
460
Private
50
8431007
Instrument rating class 4
On the downwind leg of the c ircuit, the pilot selected the land ing gear down and observed the gear down light il lum inate. During
t he land ing rol l the left wing began to lower and the left ai leron and f lap contacted the ground. The aircraft veered off the runway
before coming to rest. The left main gear leg was found to be still in the up pos ition.
Exces~ ive wear in the gear pivot points had resulted in jamming of the left main uplock. When the gear was selected down, the
act uating rod sheared allowing the gear motor to complete its down cyc le and give a normal gear down indication.
Aviation Safety Digest 123 I ix
�FINAL UPDATES (The investigation of the fo llowing accidents has been completed. The information is
additional to or replaces that previously printed in the preliminary report)
FINAL UPDATES (The investigation of the following accidents has been comp leted. The information is
add iti onal to or replaces that previously printed in t he preliminary report)
Date
Time
Date
Time
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type Rating
Record
number
24 Mar 84
OH Sea Fury-308 VH-HFG
Private
8411015
0957
Leyburn, Qld. 17S
43
2700
18
Instrument rating class 4
During the climb and initial cruise the pilot noticed that the oil temperature was rising. Shortly afterwards the engine began to run
roughly and the pilot elected to make a precautionary wheels·up landing in the only cleared paddock in the vicinity. The landing
was successfully completed within the confines of the 400 metre long paddock and resulted in the minimum damage that could
be expected.
The high oil temperature had been caused by the failure of the associated temperature sensor, which resulted In the oil cooler
shutters remaining in the closed position. These shutters cannot be controlled manually. Seizure of the number 7 piston had
caused the rough running.
29 Mar 84
Cessna 172 G VH-DJE
Commercial
8431011
0945
Cann River, Vic.
1740
700
None
33
On arrival at his destination, the pilot made a low inspection pass over the strip at about 20 feet agl In a flapless configuration at
80-90 knots. As he neared the end of the strip he pulled up steeply to about 150·200 feet. At the top of the climb the aircraft
banked to the left, descended rapidly while turning through some 135 degrees and struck the ground In a left wing down attitude.
Investigation revealed that the aircraft had been serviceable, but It was probably being operated at a low power setting
throughout the manoeuvres. The aircraft had stalled and the pilot had been unable to effect recovery In the height available.
29 Mar 84
Piper 30 VH-TON
Private
8451008
1735
Kalumburu, WA
37
980
825
Instrument rat ing class 4
The landing gear had been se lected down during descent to the destination. On arrival overhead the strip, the pilot noticed some
catt le on the strip . He became concerned with the onset of darkness and selected the gear up to make a quick pass to clear the
cattle from the strip. The gear was selected down on downwind and the selection was again checked on final' approach, but the
aircraft landed without the gear being down and locked.
inspection of the aircraft revealed that the landing gear actuator motor drew excessive current due to the armature windings
being badly burnt. Thi s resulted in the landing gear c ircuit breaker being tripped during the ret raction seq uence and the gear
stopping just before the fully retracted position. When the pilot selected the gear before landing, the gear remained in its
previous positi on. With the gear in this position, neither gear position indicator light was illuminated.
Aircraft type & registration
Location
Age
Hours Total
Pilot Licence
Hours on Type Rating
Record
number
16 May 84
Cessna 172M VH-DYM
Private
844-1015
0919
Corkwood Bore, NT
55
1748
950
Instrument rat ing c lass 4
As no one had arrived to meet the aircraft at the planned destination the pilot f lew to a strip on another property. The st rip
appeared suitable to the pilot but during the landing roll the right wing struck mulga trees on the side of the strip. The width of the
strip was subsequently determined to be 16 metres and the trees on the side of the strip were up to 5 metres in height.
16 May 84
Commercial
8411024
Partavia P68-B VH-FAD
1500
23
231
I.A. 1st c lass or class 1 with I.A.
Horn Island, Qld.
1714
Severe tu rbulence had been encountered on final approach but smooth air was entered on short final. After flaring to land, the
aircraft rol led left rapidly and the landing was made on the left main wheel, followed by the right and the nose wheels. The pilot
subsequently Inspected the aircraft but did not detect any damage. After two further f lights the pilot noticed that the left wing
appeared to be low. Distort ion of the left main gear support frame was found.
21 May 84
Cessna 182G VH-DJN
Unknown/not reported
8411027
Unknown
Townsville, Old.
Unknown
Unknown
Unknown
Unknown or not reported
During a routine 100 hourly servicing both wings were found to be bent upwards slightly. On fu rther inspection both rear spars
were found buckled just inboard of the inboard aileron hinges. None of the pilots who had flown t he airc raft since the last
periodic inspection could recall any unusual stresses being placed on the aircraft by turbu lence or manoeuvring.
The cause of the airframe overstress could not be established.
22 May 84
Cessna 1820 VH-WMF
Private
8431016
0852
Trentham, Vic. 5NE
50
919
800
Instrument rating class 4
During the flight the pilot encoun tered gradually deteriorating weather condit ions, forcing him to reduce his cruising altitude
from 5500 feet initially to below 3500 feet. Cloud covered the tops of the adjacent ranges and there were showers and associated
low cloud in the accident area. The aircraft struck the ground at 2140 feet amsl, while f lying level, banked 20 degrees r ight, under
control, and on a heading 55 degrees to the right of the flight planned track.
29 Mar 84
Bell 206-L1 VH-BJX
Commercial - helicopter
8441011
1107
Leigh Creek 85SSE
49
6660
1236
None
As part of a communications propagation test, personnel were to be positioned in the Oraparinna National Park by helicopter.
One person was being lowered by winch when, at about 3 metres below the helicopter and 4 metres above the ground, his harness
became detached from the w inch hook and he fell to the ground.
The reason for the harness becoming detached from the winch hook could not be determined.
22 May 84
Cessna 1820 VH-FRV
Private
8411026
1640
Vergemont Station
56
1045
946
None
The pilot reported that his approach to land towards the north-west was gooa; however, the aircraft floated for some distance
before touchin g down. As the aircraft landed the sun appeared from behind a cloud and the pilot lost all forward vision. Braking
was app lied but as the pilot considered that the aircraft was not slowing down and he was aware that t he strip end was near, he
applied power to go-arou nd. The aircraft failed to become airborne and coll ided with a bush and a fence beyond the end of t he
strip.
05 Apr 84
Beec h A36 VH-WH H
Private
8421016
1000
"Cobham" Homestead, NSW 37
297
78
Instrument rating class 4
The pilot was aware that a rough area existed adjacent to the threshold of the strip. He elected to land long and clear of the rough
section as sufficient st rip length remained for a safe landing. He stated that he was concentrat ing on achieving a precise point of
touchdown and did not realise until after landing that he had omitted to extend the landing gear.
The landing gear warning horn was subsequently found to be unserviceable.
The investigation did not reveal any fault with the aircraft that could have contributed to the accident.
09 May 84
Bell 47·G381 VH ·CSE
Commercial - helicopter
8451011
1645
Mable Downs 12N
34
5900
5700
None
The fuel gauge was unserviceable and a dip stick was not available. The pilot estimated that there was two hours fuel remaining
by inspection of the contents of the left hand tank only. Seventy minutes after takeoff the engine stopped and an autorotational
landing was attempted. The terrain was very rough and during the landing the tail rotor struck a tree and the main rotor blades cut
off the tall boom.
The pilot had delayed his departure because of personal busi ness commitments. The delay was such that the pilot had
Insufficient time to carry out refuelling and then reach his destination before last light. When the engine failed from fuel
exhaustion the aircraft was being flown over rough terrain which was less than three ki lometres from a road which ran parallel to
the desired track. No mechanical fault or defect was found which would have caused premature fuel expiry.
10 May 84
Cessna T188C VH-HAM
Commercial
8421021
1400
Walgett, NSW 25S
32
2200
400
Agricultural class 2
The pilot was landing at the conclusion of the second spraying operation for the day. She aimed to touch down about half way
along the 700 metre strip to allow a followi ng aircraft to land behind her. During the latter stages of the landing roll the tail rose
and the aircraft overturned.
As the brakes were applied the pilot slid forward in her seat and her shoulders were released from the seat harness. This resulted
in increasingly heavy braking being Inadvertently applied, together with forward movement of the control column.
13 May 84
Cessna 337G VH-KUX
Commercial
8441014
1326
Gove, NT
24
899
440
I.A. 1st class or class 1 with I.A.
Prior to commencing a 60 minute flight the pilot estimated that the aircraft had fuel for 120 minutes. The front engine fai led when
the aircraft was 25 km from its desination. The rear engine subseq uently failed and a glide approach from 9 km and 3000 feet was
commenced. A 15 knot headwind was present and the aircraft landed 7 metres short of the aerodrome boundary fence. The right
main gear was torn off in a ditch during the 135 metre ground roll.
When the aircraft was last refuelled, it was not filled to capacity and the pilot probably Inaccurately estimated the amount of fuel
on board. Fuel usage rates did not vary significantly from those used by the pilot for flight planning. The fuel gauges were found
to overread in the lower quantity range.
x I Aviation Safety Digest 123
23 May 84
Cessna 150L VH-DNE
Private
8451012
1340
Pinnacles Station, 8NW
35
1566
1260
None
The aircraft was being used for sheep spotting. Three hours had been flown since the last refuelling and the pilot noted that the
fuel gauge was indicating close to empty. He considered that enough fuel remained for a further 40 minutes; however, 5 minu tes
later the engine st opped. During the ensuing forced landing two trees were struck and the ai rcraft sustained substantial damage
to both wings and the tail section. Less than 3 litres of fuel was subsequently drained from the fuel system.
The pilot made onl y mental estimations of the expected fuel endurance of the aircraft and confi rmed these by reference to the
uncalibrated fuel gauge. As the aircraft was being f lown at 200 feet agl when the engine suffered fuel starvation, insuffic ient time
was available to the pilot to select a more suitable landing area.
26 May 84
1515
Piper 28-140 VH-MTU
Haxton Park, NSW
19
46
Private
6
8421023
None
The aircraft bounced after the initial touchdown and subsequent ly porpoised a number of times before the pilot was able to
regain cont rol of the landing. He later inspected the aircraft but did not not ice any damage which might have occurred during the
landing. On the subsequent takeoff, pitch attitude control difficulties were encountered and the pi lot carried out a low level
circuit and landing. Damage to the rear bulkhead and stabilator trim support brace was discovered.
The damage had been sustained during the initial touchdown , which had been on the mainwheels and the tail skid, and had
probably accounted for the pilot's difficulty in controlling the subsequent porpoises along the runway.
27 May 84
Quickie 02 Not reg.
Private
8421026
1600
Warnervale, NSW
54
476
Unknown
None
The pilot had finished construction of the aircraft and was conducting ground handling trials. He reported that on the final tax iing
test the aircraft suddenly became airborne. There was insufficient strip length remaining to safely land again and the pilot
climbed the aircraft to 2000 feet and carried out handling manoeuvres before returning to land. The aircraft landed heavily and the
right canard was fractured.
31 May 84
Cessna U206G VH-AZC
Commercial
8421025
2152
Goulburn, NSW
39
3275
106
I. A. c lass 4 with f light instructor
The pilot under instruction was training for the issue of a Night VMC rating. At about 250 feet ag l on approach considerable sink
was experienced and the aircraft descended below the desired approach path. Power was applied and the nose was raised but t he
sink continued. The instructor took control and initiated a go-around; however, the left main gear wheel collided with a fence and
was dislodged. Control was maintained and a safe landing was subsequent ly carried out on return to Bankstown.
Aviation Safety Digest 123 I xi
�FINAL UPDATES (The investigation of the following accidents has been completed. The information is
additional to or replaces that previously printed in the preliminary report)
Pilot Licence
Hours on Type Rating
Date
Time
Aircraft type & registration
Location
Age
10 Jun 84
1145
Burkhart Astir CS
Kimba, SA 30S
24
104
Glider
53
18 Jun 84
0705
Hughes 269C VH-SMT
Moala Bulla Station
34
882
Commercial 785
Hours Total
VH-WUK
Record
number
8441019
Glider
While ridge soaring at a low height and 50 knots, the pilot noticed a dead tree a s hort distance ahead. The glider mushed during
the attempted pull-up; the left wing hit another tree and the glider turned through 90 degrees befo re colliding with the upward
sloping ground.
helicopter
None
8451014
The pilot had planned to carry out a cattle muster in conjunction with another aircraf t. He had been late in departing his base, but
when he found the other aircraft had not yet arrived at the rendezvous point he decided to make a quick comfo rt stop. The
helicopter was landed on a spinifex-covered area and the pilot disembarked leaving the engine running . Shortly afterwards he
noticed a fire underneath the helicopter and reboarded, in an attempt to fly it away from the fire. The engi ne d id not respond. The
pilot disembarked and attempted unsuccessfully to extinguish the fire. He received bu rns to his hands and legs while unloading
equipment and the helicopter was destroyed.
29 Jun 84
0930
Piper 25-235A1 VH-MYE
Leongatha, Vic. 8SE
32
6000
Commercial
2000
8431018
Agricultural class 1
A spray run was being flown along the boundary of a paddock. One tree infringed the run and the trai nee elected to ap ply rudder
to direct the aircraft past the tree. Incorrect rudder was applied and the instructor took over but the left wing struck the tree. The
instructor was able to maintain control although one metre of wing and the aileron had been torn off. He landed the aircraft in the
adjoining paddock without further damage.
ART
~ MODEL
WORK5HOP
. on your next visit, Miriam, smuggle in a 260-hp Lyc oming . .
An untrained mustering pilot
T h ere are many facto rs which con tribute to the making
of a good pilot. A few of these , which will be presen t to
different degrees in differen t individuals, are common
sense, a ircraft systems knowledge , person al reliability,
knowledge of associated su bjects, n atu ral ability and a
m a ture appreciat ion of one's own limita tions.
One factor which m ust always be present is good
training, both in relation to basic piloting skills and
sp ecialised flying tasks. Any pilot who attempts to
complete a task for which he has not been correctly and
thoroughly trained always runs the risk - for which the
stakes a re the ultimate - that sooner or later that lack
of training will fi nd him out. Such was the unfortunate
case with a young, inexperienced pilot who accepted
emplo yment mustering cattle without having undergone
proper training.
*
*
*
After gaining his commercial licence the p ilot m anaged
to fly o nly four times in t he following eight m onths.
Eventually, he secured employment at a cattle station
and , realising that he would be required to ca rry out
cattle mustering flights, arranged a brief period of low
fl ying training with an experienced agricultural pilot.
As the check pilot h ad no experience at cattle
mustering , training was limited to general manoeuvring
a t a h eight of 200 feet. T he improperly and
inadequately trained p ilot then began flying for the
sta tion .
The station man ager had employed pilots who were
not trained or a pproved for cattle m u stering on a
number of occasions. H e would then instruct them a s to
the manner he wished the aircraft to be manoeuvred
during mustering flights. Although he h ad never held a
pilo t licence, the manager was familiar with aerial
musterin g as h e n o rmally flew in the aircraft, directing
operations and maintaining commu nications with
stockmen on the ground by means of a portable radio.
T o m ove cattle from beneath trees, he would instruct
the pilot to dive the a ircraft steeply to tree-top level,
then p ull up into a steep climb and carry out a wingover turn into the next dive. T he new pilot complied
with his employer's instructions~ althou gh h e was
reported to have subseq uently stated that, on a n umber
of occasions, he h ad alm ost stalled the aircraft dur ing
the win g-over turns.
W eat her conditio ns at the station on the morning of
the accident - on e week after the pilot had started
m ustering - were good: the surface wind was a light
sout h-easterly, there was a broken cloud cover at an
altitude of about 3500 feet a nd visibility was
unrestricted, excep t in isolated rainshowers. T he
aircraft - a Cessn a 172 - was working in conj unction
with a number of stockmen on horses and motorcycles
to m uster cattle some 20 km north-west of the station
homestead.
A fter abou t an h our's flight the aircraft was observed
making a number of steep dives to tree-top level,
apparently to move cattle adjacent to a creek. Following
o ne dive the Cessna was seen to pull up steeply to an
estimated h eigh t of 400 feet, then stall and dive into the
xii I Aviation Safety Digest 123
ground. I t impacted at an angle of about 73' degrees
a nd broke apart. The main wreckage bounced
28 metres before coming to rest against some trees.
Both the pilot and the sta tion manager, who was flying
as spotter, were killed.
An investigation found no evidence of pre-existing
aircra ft mechan ical defect or malfunction; nor was there
any evidence of pilot incapacitation.
Using an aircraft model, a witness demonstrates for air
safety investigators the aircraft's attitude and position
immediately prior to impact.
*
*
*
T here is no need for any comment on this accident
other than to repeat the accident's relevant factors,
determ ined by the Bureau of Air Safety Investigation :
• The manager employed a pilot for cattle m ustering
who was neither trained nor qu alified for the
operation.
• The pilot accepted the employment.
• The m anager instructed the pilot to m uster cattle in
a manner which required maximum a ircra ft
manoeuvring performance and high p ilot skill, and
which, at the low h eight involved, left no margin of
safety.
• The pilot complied with the manager's instruction,
thereby abrogating his command responsibility for
the safe operation of t he aircraft.
• The pilot lost control of the aircraft at a height too
low to permit recovery e
Avia tio n Safety Digest 123 I 13
�Landing area standards
Landing is the phase of flight during which most
General Aviation accidents occur. In one a nnual survey
of accidents prepa red by the Burea u of Air Safety
Investigation , 50. 7 per cen t of GA accidents were found
to be associated with this phase. The precise breakdown
was as follows:
6.9 per cent
• Approach
21.5 per cent
• Level-off/touchdown
16. 7 per cent
• Roll
3.0 per cent
• G o-around
2.6 per cent
• Other
Given that data, it is apparent that pilots should try to
ensure that as many factors as possible are working in
their favour during landings.
One of those factors is the state of the landing area,
where items such as surface condition, gradient,
dimensions, elevation and approach path are all
important. The hazards attendant in ignoring those
items are apparent in the following two summaries of
landing accidents.
*
*
practice, the pilot was planning to land on the grass
strip immediately adjacent to the sealed runway.
When he was on short final approach at about
50 feet, the pilot noticed that a glider had been pushed
onto the grass strip and was infringing his intended
landing path. Instead of initiating a go-around h e
decided to land on the area alongside the grass strip.
This apparently was not unusual: from subsequent
discussions with a number of people it emerged that it
was customary to use most of the aerodrome as an allover field.
However , in this instance the practice came unstuck.
After touchdown, the aircraft became entangled in
tall weeds, tipped onto its right win g and then
overturned, sustaining considerable damage. The
'grass' area which had looked acceptable to the pilot
from a height of 50 feet consisted of Patterson' s Curse
and other weeds ranging from heights of about half a
metre at the beginning of the landing r~.n to about
1.5 metres where the aircraft came to rest, inverted
(Figure 2).
*
An agricultural aircraft had completed a spraying run
and was returning to land on a strip located in an
oatfield. The strip's width was 15 m etres while the
aircraft's wingspan was 12.7 metres.
At the edge o f the strip the average height of the crop
was 1 metre. After the aircraft h ad made a n ormal
touchdown , the right wingtip contacted a patch of oats
growing on a slight mound, and which stood about half
a metre high er than the rest of the crop. This caused
the aircraft to swing rapidly to the right, in the course
of which the fuselage was severely buckled , and the left
wingtip and left horizontal stabiliser were substantially
damaged (see Figure 1).
In the second occurren ce an aircraft was approaching
to land after an aerotow sor tie. As was common
Comment
The specifications for Authorised Landing Areas (ALAs)
are detailed in the Visual Flight Guide {VFG). Those
standards are considered to be the minimum to ensure
safe operations over an extended period. As these two
expensive acciden ts showed, persistent disregard of
those standards is likely, in the lon g run , to catch up
with those who choose to ignore them.
It cannot be overemphasised that opera tions into
landing strips will only provide the necessary margin of
safety if the strip:
• meets the specifications for ALAs set out in the VFG,
and
• has been carefully surveyed from ground level •
Figure 1. General view in direction of landing. Note initial entry point of aircraft into crop.
In brief
While a Lockheed Tri-Star was cruising at 35 OOO
feet e n route from Cyprus lo London, smoke was
observed in the cabin at passen ger seat 39F. No
flames were visible but the seat m a terial was
smouldering.
.
A BCF fire extinguisher was used, followed by a
water extinguisher to prevent re-ignition . Smoke
evacuation procedures were completed and the
flight continued to London without further
incident.
The burning was found to have been caused by
a cigarette which had dropped between the
armrest and the seat cushion. It was concluded
that the fire retardant properties of the seat
cushion m a terial satisfactorily retarded
combustion.
•
•
14 I Aviation Safety Digest 123 .
*
Manoeuvring his Cessna 210 into a limited parking
space, the pilot was aware that his vision in the
direction he wished to turn was partly obscured by
his passenger and the aircraft's nose. Nevertheless,
believing his path was dear he conlinued taxiin g. He
stopped when he heard the Cessna's propeller
striking something. The 'something' turned out to be
a me tal 'No Standing' sign, which bent the outer
100 mm of all three blades about 90 degrees
backwards.
While airport staff do their best to ensure p arking
areas are clear, it remains the pilot's responsibility to
ensure his aircraft is clear of all obstructions when
taxiing. Taxiing accidents are usually inexcusable: if
there is any doubt about whether your intended path
is clear, slop, and get someone lo have a look before
you proceed; or shut the aircraft down and have it
towed •
Figure 2. View back along aircraft's touchdown path, taken from accident site. Person standing amongst the 'grass' is
183 ems tall.
·
Aviation Safety Digest 123 I 15
�Declare your emergency
There seems to be a curious reluctance on the part of some pilots to declare an emergency. By
failing to do so they needlessly, and often irresponsibly, expose their passengers, their aircraft and
themselves to additional, unnecessary risk by possibly delaying the call-out of rescue services. The
following accident is a case in point.
Shortly after takeoff the top engin e cowl from the right
engine of a commuter aircraft separated from its
mounting and struck the right horizontal stabiliser
about midway along its span. T he aircraft was
travelling at 140 KIAS at a height of 300 feet .
The cowling wrapped itself around the horizontal
stabiliser with a bout one-third of its a rea over the upper
surface. Severe buffeting was experienced; the pilot
later reported that the aircraft lost a bout 60 per cent of
controllability in pitch. A turn on to a cross-runway
was commenced and power reduced to maintain 140
knots.
The aircraft was landed safely with the engine cowl
still firmly embedded in the h orizontal stabiliser. A
M ayday call had not been transmitted.
Wh en the critical situation arose, the pilot did not
em ploy the Distress and Urgency Message procedures
deta iled in the En Route Supplement. Instead, he
a ttempted to communicate the serious n ature of his
predicament to Air Traffic Control by a hurried
description of the technical problem.
This message was not full y understood but the sense
of urgency in the pilot's voice indicated to the Tower
Controllers that a potentially hazardous situation
existed . Fortunately, air traffic at the time was qu iet.
H ad there been nu merous movements, creating th e
complex, high workload th at often prevails in ATC, the
controllers would have been faced with a most difficult
problem. They were expected by the pilot to interpret
the seriousness of his circum stances - a most
un reasonable presumption.
In the event the controllers, of their own initiative,
activated the crash ala rm.
A similar pattern of events unfolded when the pilot of
a ligh t piston engine twin h ad to close down one engine
wh ile cruising at FL150.
After securing the en gin e, the pilot advised ATC of
his intention to divert to a nearby airport but did n ot
declar e an emergency. Again, ATC took the initiative
and implemented an Alert Phase and Aerodrome Alert
Procedures . It is noteworthy that the diversion airport
was some distance from the town it served and, as a ll
emergen cy services had to come from that town , a
delay in callin g them could have been cr itical.
Having landed safely , the pilot commented that he
felt the aircraft's situation h ad been h azardous from the
time the en gine was shut down . In particular he stated
tha t, given the icing conditions which prevailed for the
descent, the extensive cloud cover and low cloud base at
the diversion airport, and the marginal single-engine
perform ance of his machine, the emergency services in
attendance for his landing 'were very much
appreciated ' .
That be ing the case, it is hard to understand why he
had not declared a n em ergency himself as soon as his
problem became apparen t.
16 I Aviation Safety Digest 123
Nothing on the clock but the
maker's name - literally
DISTRESS AND URGENCY MESSAGES
DISTRESS MESSAGE
URGENCY MESSAGE
(IMMEDIATE ASSISTANCE
NOT REQUIRED)
(IMMEDIATE ASSISTANCE REQUIRED)
-USE WHEH AIRCRAFT I H GRAVE
AHO IMMIHEHT DANGER
-TRAHSMI T
•MAYDAY MAYDAY MAYDAY
•NAME OF UNIT ADDRESSED
-USE WHEH AI RCRAFT EXPERI EHCIHG
DIFFICULTIES IH HAVIGATIDH,
AIRCRAFT PERFORMANCE, ETC; OR
SAFETY OF SOME PERSON OH BOARD
OR WI THI N SIGHT I S INVOLVED
•AIRCRAF T IDENTIFICATION
•NATURE OF DISTRESS CONDITION
-TRANSMIT
•PAN PAH PAH
•INTENTION OF PERSON IN COMMAND
•NAME OF UNIT ADDRESSED
•AIRCRAFT IDENTIFICATION
•PRESENT POSITION, FLIGHT LEVEL
OR ALTITUDE, HEADING, AIRSPEED
•NATURE OF URGENCY
AND ENDURANCE
CONDITION
•NUMBER OF PERSONS ON BOARD
•INTENTION OF PERSON IN
COMMAND
-TURH OH AUTOMATIC EMERGENCY
•PRESENT POSITION, FLIGHT
EQUI PMENT IF PROVI DED
LEVEL OR ALTITUDE AND
-SQUAWK SSR CODE 7700
HEADING
•ANY OTHER USEFUL
INFORMATION
-SQUAWK SSR CODE 7700
IF COMMUNICATION CANNOT BE MADE ON PRESCRIBED ROUTE
FREQUENCIES, OTHER FREQUENCIES MAY BE OF SOME ASSISTANCE.
THESE ARE Being the ollocoted distress frequency for transmission of
H E_
L B(A} s1gnah. It is monitored fr~m time .to t1m~ by domestic
VHF - 121 · 5 M 2 oircrofl and contlnuoui.ly by most 1nternot1o nol orrc,oft.
Ground monitoring is not ovoiloble.
As for 121.5 except that it is monitored by all RAAF aircraft
UHF-243 MHz
;n ll;ght ond by ground stot;ons ind;coted ;n ERS/COM
section.
n ·
'--o
...,
b
!)
'
0
"I
0
~
Comment
It is occasionally suggested tha t pilots are r eluctant to
declare an emergency because this might somehow
reflect on the ' macho' image sometimes associated with
fl ying. Such attitudes can only be described as
misguided in the extreme. If you overhear 'bar talk ' to
th at effect, the sp eaker's operational judgment and
appreciation of p ilot responsibility must be regarded as
highly suspect.
Australian Air Traffic and Flight Service Officers are
h ighly trained a nd mot ivated individuals who can be of
great assistance to pilots experienci ng difficulties. They
understand the pressures flying can create and want to
help. It is up to you to ensure that a request for help is
not left too la te.
Pilots with an emergency should also appreciate that
if they are operating into an airport wh ere the landin g
priority system is in force, and depend ing on their class
of operation (e.g. RPT, C harter, Private), they may not
necessarily be given priority to land unless tha t
emergency is formally declared .
The m essage is clear. Declare your emergency,
preferably in the format advised in the En R oute
Supplem ent •
The 'there I was ... ' and ' nothing on the clock . . . '
stories ar e well known (some may say too well known)
in every clubhouse around the world where aviators
meet, especially during social occasions. The following
occurrence is a classic of the genre - especially as it is
guar anteed authentic! It was first reported in the U.K.
magazine, Flight Safety Bulletin.
A Beagle 206 twin took off from Oxford fo r a
Certificate of Airworthiness renewal air test. Forecast
weather included isolated snow showers and 6-8 oktas
of cloud, base 300-2000 feet and tops 7000 feet.
Following a si ngle-engin e clim b to above 8 oktas at
6000 feet, on restarting the other engine the gyro
compass froze. So the pilot began a recovery to Oxford
with the help of Cotswold radar. It then becam e
apparent that radio tra nsmission had failed although
reception was still available. So the transponder was
switched to 7600 and a rapid descent begun in a
relatively clear patch. The aircraft's anti-icing system
was not working, then the left hand fuel gauge contents
indication fdl to zero, the DME stopped indicating, the
No. 1 VOR failed , there was no response on the ADF,
a nd No. 2 VOR gave only a weak response to H onily.
When visual contact with the grou nd had been made
between snow showers, the pilot tried to work out
where he was and eventually Tewksbury was recognised
a nd course set to fly along the motorway to Staverton.
By this time the artificial horizon had failed and the
heater would no longer work. Staverton was overflown
at 250 feet but visibility in the falling snow was such
that it was not possible to manoeuvre for a landing.
After circling for about five m inutes in clear air by the
River Severn, course was again set from a known
landmark fo r Staverton where the pilot was fortu nate
enough to arrive lined up with runway 09. The
engineer- observer lowered the undercarriage using the
emergency system a nd, although no greens were
indicated , the aircraft landed safely.
There was no mention of whether or not the
Certificate of Airworthiness was renewed! •
Aviation Safety Digest 123 I 17
�~eat:We
Complacency and aircraft
knowledge
We departed Arch erfield and after obtainin g a irways
clearance climbed di rect to 6500 feet. Altitude was
reached ab out Samfo rd and Brisbane a pproach a sked us
to squawk code 3000 and ident. There seem ed to b e
some difficulty with the transponder and appa rently it
did not register on the rad ar . There was some small
discussion between m yself and ' the ma n ' but after
con firming that 'op erations were normal ' I a ssum ed
tha t the problem had been r ectified a nd we were well
on the way.
Abeam G ayndah - 65 minutes into the journey as part of my position reports and normal in-fligh t
checks, I switched the fuel cock to the right t ank having
flown off the left tank since depa rture from A rcherfield ,
noticing at the same time tha t the left tank now
indica ted quarter full, which wa s normal for that
duration of flight at the 60 p er cen t power setting of
2100 RPM and 20.6 MP , at 5000 feet and 2 points
under EGT .
Som e time just befor e reaching Rockham pton I
remarked to m y comp anion in the right h and seat tha t
'the right fuel tank indicator seemed to be takin g a long
time to register ', i.e. com e d own below the ' full' m ark,
a nd since we h ad been fl ying for ab ou t an hour on the
tank , I switched on the electric pumps which transfer
fuel from the ou tboard a uxiliary tanks to the m ain
inboard tanks, a s was normal procedure .
App roximately 2 m iles north of Glen Prarie Station ,
th e en gin e cut ou t, surged again and then died .
Immediately, I switched on the fuel booster and
selected rich mixtu re . T he en gine gave a couple mor e
su rges, so I decided to make a forced lan ding at G len
P rarie H om estead where there is a n excellent grass
a irstrip.
T he aircraft was set up in the glide, all switches
checked and I a dvised R ockhampton Flight Service of
m y p roblem an d in ten tions. M y passenger was fully
b riefed fo r a fo rced landin g and during the d escent I
did a co mplete, though fr ui tless, check of all
instrumen ts and switch es to try to fi nd the problem.
O n tu rni ng base , I realised that I still had power and
used it to m ake a no_rmal approach and la nding at G len
Prarie.
After a su ccessful landing we exited the a ircraft and I
proceed ed to do o ther , thou gh equally fruitless, external
checks to see what had happened , and after climbing
back into the cabin, started the engine a nd ra n it at full
power fo r several minu tes, an d all seem ed to be in
perfect working order .
I m ust admit th at du ring the descent I had not tried
the left tank becau se it was inconceivable that I ha d ru n
out of fuel on the righ t tank after only 90 minutes of
fligh t a nd knowing that the tanks were full wh en I left
A rcherfield and that the tank caps we re on tight , a nd
tha t I had been transferring fuel fo r some time. The
right tank was still indicatin g well over qu a rter full
18 I Aviation Safe ty Digest 123
which was also nor mal for th at tank after 60 minu tes or
so of flight.
Arrangem ents were made to br ing a LAME out fro m
Rockhampton and together we set about solving the
m yster y .
The cowls were removed and all ch ecks such as fuel
to the carburettor, auxiliar y fuel tank pumps, electrical
equipment etc. were carried out with no fu rther
indication of the cause of the trouble. T he engine was
again run up for several m inutes a nd from all
indications ever yth ing was op erating no rmally. We
came to th e con clusion that whatever happened the
problem had now rectified itself and we should be safe
to get airbo rne again.
·
H owever , before doing so I d ecided to recheck my
flight plan , and determined that I h ad in fact flown 108
m inutes on the right inboard tank. By itself this would
have b een en ough to run it d r y, but b ecause the fuel
tran sfer pump ha d been o n to transfer fuel from the
right auxiliar y tank , there should have been at least
a nother 40 m inutes of fuel left in the m ain tank.
T h e LAME climbed up on to the wing and confirmed
tha t the right ma in tank was almost ' bon e d ry' . This
raised suspicions about the righ t hand fuel transfer
pump , as th ere wa s still a mple fuel in the r ight
auxiliary tank.
Fu rther investigation revealed that the venting tube
on tha t au xiliary tank was pa rtially blocked in some
way and could not be cleared on site. This accounted
for the su rging of the en gine while airborne as the fuel
was n ot being tran sferred at th e n ormal 15 gallo ns per
hour to m ake up for the en gine u sage of 11 gallon s per
h our.
After the problem was discovered, all fuel available
was transferred to the inside tanks and in d ue course we
dep arted G len Prarie a nd ar rived in Mackay where the
necessar y work to clear th e blocked vent was com pleted.
O n the fl ight immediately preceding this one , the
aircraft ha d developed a co mplete electrical failure in
fligh t which resulted in a n uncer ta inty phase bein g
declared on the a ircraft , and a la nding at Arch erfield
with no r ad io , althou gh I did code 7600 on the
transpon der .
The trouble in this case ha d been traced to a fau lty
alternator, which was replaced, as well as the batter y.
Because of the length of time spent in this a ircraft
recently, I h ave becom e com pletely familiar with all
phases of its operation and kn ow wh a t the fuel gau ges
'should look like ' after various periods of time in the
air. The erratic n atu re of the right hand m a in fuel
gauge I blamed o n the electrical system; indeed , it
made me wonder whether in fac t I was developing
an other electrical failure in fl igh t, particularly as I h ad
transp onder trou ble durin g the fligh t as previou sly
stated . T h e com b ination of 'knowing' how much fuel I
had in the right h a nd tan ks and sheer fright at the time
Seat collapse on takeoff
A nor mal takeo ff was being carried out in a Cessna
180 . W ea ther con ditions we re good an d the bitum en
runway dry . As the indicated a irspeed reached 50- 55
knots , a nd with the tail wheel clear of the ground ,
the p ilot was just about to rotate when the back of
his seat collapsed . H e let go of the control column as
he fell backwards and his feet lifted from the rudder
pedals, but he retained his grip on the throttle long
eno ugh to reduce th e power to idle. H e was also able
to reach for ward far enough to pull the park bra ke
h andle full on .
T he C essna groundlooped to the left and ran on to
a taxiway a bout 180 metres from the threshold. At
thi s point the right main landing gear was broken
from the fuselage. T he engine stopped as the
propeller struck the bitumen su rface an d the right
ou ter mainplane was bent upwards on contact with
the ground . D am age was su ch that the a ircraft was
no t econ om ically repairable .
It was determined that the left-hand sup por t tube
of the seat back failed initially a nd the right-hand
supp ort t ube then fa iled because of overload.
P rogressive overload failures of other minor seatsupp ort structu res followed.
Exa minatio n showed that the left-hand support
t ube had a pre-existing fatigue crack over onequ arter of its circumference and it was from this that
the tot al failure originated. T he cause of this preexis ting crack should be of interest to all pilots,
LAM Es a nd a ircraft p assengers.
T he left-hand side of the seat back, together with a
'gr ab' handle on the fo r ward door post, is generally
used by p eople to ha ul themselves into the aircraft.
Fu rther , th e fron t seat backs a re hinged to allow
access to rear sea t passengers who also tend to lean
created a men tal situation that caused me to overlook
the op tion of ch angin g to the left tank. For the reasons
described below, this m ay have been fo rtuitou s.
While the inciden t can be put down to 'experience' ,
par ticularly as nobody was injured, there were a
n umber of extremel y lucky featu res that in retrospect,
with ou t such luck , cou ld have resulted in inj u ry an d/o r
death.
T hey were:
1. Lucky that G len Pr a rie Station had an airstrip and
althou gh I had seen it before on other trips and was
aware of its existence, I had only ju st pointed it out
to m y companion and we both saw a 'twin'
sta tionary at one end of it, which helped in locating
it .
2 . L ucky that the a uxiliary pump was transferring some
fuel during the descent from 5000 feet which enabled
a powered landin g at G len Prarie.
3. Lucky th at we fou nd the partially blocked vent in the
outer tank on the ground. In all probability I would
have taken off again still on the right tank, which
wo uld most certainly have resulted in an engine
failure o n takeoff with potentially disastrou s results.
on those seat backs during entry to the cab in. I t
seems probable that this extra loading on the pilot's
seat back, over a long period, caused the initial
fatigue cracking of the support tube .
Comment
I t is only possible to t horoughly inspect this
particular support tube in the C essna 180 by
partially removing the seat's upholstery . This m ay
seem to be a nuisance at the time - yet consider the
effort involved against the cost of an a ircraft. The
cost may well have been greater too had the seat
collapsed shortly after takeoff.
This accident serves a s a timely reminder that all
components of an aircraft's structu re - r anging
from seats to spars - must be treated with respect.
O ften, compon ents may have extreme strength in
one direction but very little in another (the landing
gear is a prime example of this). Whenever we are
doing things like getting in and out of an aeroplane
or climbing onto a wing to complete an inspection,
we should ensure that no component is subjected to
a stress for which it was not in tended •
4. L ucky that I did not switch to the left tank in the
glide because I would probably have carried on to
M ackay or returned to R ockhampton and the whole
incident put down to fuel starvatio n and
incompetency on my part. T he partially blocked fuel
tank vent would almost certainly not have been
discovered and the incident m ay have been repeated
over much less hospitable cou ntry with potentially
tragic results.
5. L ucky I know a n excellent drycleaner .
Morals
1. D on't become so complacent that you think you
know your aircraft so well th at you can p redict all its
habits - particularly with regard to fuel gau ges.
2. When the bells ring - listen! e.g. 'That fuel gauge
is taking a long time to register - I wonder if we
are developing another electrical problem'.
3. If a forced/precautionary land ing is made, never
attempt to take off again until you have m ade
absolutely sure that the problem h as been found and
rectified •
Avia tion Safety Digest 123 I 19
�It's not worth the risk
After finding the mob of cattle for which he had been
looking, the pilot of a Piper PA18 decided to land on a
claypan to pass on the information to the ground party.
H e had already landed there once earlier in the day .
Weather conditions were clear and there was a
headwind of 10-15 knots. Landing distance available
was about 120 metres.
T he pilot la ter stated tha t h e always chooses a goaround point for short landings; if the aircraft has not
touch ed down by that p oint, he abandons the approach.
O n this occasion he misjudged the a pproach and,
having passed his 'landing point', decided to go
around . According to the pilot, when he opened the
throttle the engine did not respond and thus he was
forced to continue with the landing.
At this stage he still felt that h e would be able to stop
the aircraft safely. However, to add to his troubles, the
wheel brakes did not operate as efficiently as he
expected a nd it became apparent that the C ub was
going to overrun the la ndin g area. To avoid th is the
pilot decided to groundloop the aircraft. In doing so,
the aircraft's left wing struck a sapling while the left
main landing gear was torn away. O verall damage was
assessed a s substantial.
Flight safety aspects a rising from this accident involve
the engine , the pilot's attitude towards the u se of
P-charts a nd the condition of the wh eel brakes.
• The spark plugs were fou led by lead , although not
sufficiently to prevent them working (the pilot stated
that he h ad been h aving trouble for some time with
oiled plugs) .
P- charts
Aviation Safety Digests 118 and 120 included detailed
articles o n th e importan ce of using the landing weight
charts and takeoff weight ch arts - generally referred to
as P-charts - wh ich are contained in each aircraft's
D epartment of Aviation -issued Fligh t Manual. These
charts are the only author ised source of takeoff and
la nding data for Australian operations .
In this instance , reference to the P-charts for the
PA18 sh owed that the landing distance required was
about 250 m etres . As it was ther e were only 120 metres
..-available and the aircraft floated for 60 of those before
touching down .
Notwithstanding his earlie r su ccessful landing on this
area, the fact was tha t the p ilot was operating without
any safety margin.
The wheel brakes
T he technical report prepared on the engine following
strip-dow n showed no irregularities which would have
cau sed a n unexpected power loss. Gen eral engine
cond ition was, however, poor:
Both brake master cylinders were fo und to be leaking
because of the deterioration of rubber seals. This was
attributed to th e use of a u tomotive b rake fluid, which is
vegetable based, instead of the approved synthetic-based
aircraft fluid .
20 I Aviation Safety Digest 123
The human eyeball Mark I is a very versatile apparatus
that serves u s well . It has, however, even with 'perfect '
sight, physical limitations in its performance. One such
lim itation is its power of resolution - that is, the
m inimal size of an object that can be registered - due
to th e construction of the sensor, the retina. In some
respects the retina resembles the grain of black-andwhite photographic film. The grain is the finite size of
the sen se organs, the cones. (T h e periphery of the
retina is coarse grained and picks up movement but not
detail, while the cen tral part is fine grained and
register s detail.) As anyone who has enlarged blackand-white film knows, the grain itself limits the detail
that can be obtained.
The usual country power line or telephone wire when
viewed from a safe (in flying terms) distance makes too
small a visual angle for it to register on the cones. H ow
then do we ever see it? Under specific conditions, that
is against a plain cont rasting background such as the
sky, the eye has a comp ensating mechanism that relies
on this contrast. In effect, we perceive the break in
cont inuity of the background rather tha n 'seeing' the
wire itself. Our mobile computer, the brain, happily
translates this into seeing. However, reduce the contrast
and break up the backgrou nd and we a re thrown back
on to the basic visual m echanism limited by the grain
(cone) size. The wire literally disappears. It is not
'camouflaged' it is beyond the limits of the eye to see
it and no matter how hard we stare, squint or move our
heads we will never be able to see it. We are wasting
our time looking.
T hese physiological facts have obvious and important
implications for pilots in country areas, particularly
agricultural pilots a nd those who must have a 'closer
look'. Where it is necessary to fly low in the course of a
job, up-to-date charts of line obstructions must be
obtained and supplemented by a ground survey. The
extra power line to a shed has frequently appeared since
the last time the area was flown . For those who must
look closer, an adequate safety height must be
maintained and prudence obser ved wherever pylons can
be seen.
D o not, repeat do not, expect to spot wires from the
air; your visual apparatus is not sufficiently sensitive,
and if you do see them it will be 'too late' e
P-charts are factor ed to cater for such variables as
pilot handling techniques and abilities and aircraft age
and co ndition .
T hose who have become uncertain on the use of
P-charts are urged to refer to Digests 118 and 120.
The engine
• Externally, the e ngine was very dirty.
• The carburettor venturi a nd butterfly were coated in
red dust, indicating poor air fil ter m aintenance. O n
further dismantling of the carburettor this du st was
fou nd packed in behind the venturi.
• T he cylinder bores were bad ly worn, as were the
exhaust valve stems and g uides.
•
"Why didn Jt I see that wire
until too
late?
Comment
T his pilo t got away once with a poorly main tained
aircraft and igno ring the P -ch ar ts, but not twice. H is
a ircraft was badly damaged, and it could have been
worse. Is it really wor th the risk? e
Aviation Safety Digest 123 I 21
�r
Keep flying your aeroplane
CPliotographit annpetitimt.
The Aviation Safety Digest is pleased to advise readers that it is conducting a photograp hic competition for all
Australia n aviation enthusiasts .
Immediately after a Bonanza became airborne the
forward cabin door opened. Apparently alarmed and
confused, the pilot turned left on to downwind instead
of entering the designated right-hand circuit pattern.
Witness assessments of the aircraft's height on
downwind varied, but it seems that it descended fairly
quickly. It was then seen to bank steeply to the left and
strike the tops of trees and two heavy posts before
crashing nose-down into a vineyard.
The pilot and front seat passenger sustained facial
and other injuries. Although both had fastened the lap
section of their seat belts, neither had bothered to use
the shoulder restraints. Another passenger who was in
the right centre seat, and who had been attempting to
close the door, was thrown forward out of the door
(which o pened fully on impact) and hit the ground
ahead of the aircraft. The injuries to all three occupants
were serious.
Analysis
Subsequently the pilot was unable to recall any aspects
of the accident. There was, however, no evidence to
suggest that the door or its locking mechanism were
unserviceable; on the contrary, the aircraft had flown
the previous day without any problem of this nature
being reported. It therefore seems probable that for this
flight the door was not closed correctly.
Because of the pilot's memory loss it was not possible
to de termine positively the cause of the accident.
However, when the door popped open unexpectedly in
flight the pilot would have been subject to a very loud
and sudden airstream noise. G iven the witness
descriptions of the erratic attempted circuit, and the fact
that the aircraft's nose dropped rapidly immediately
before impact with the grou nd, it seems highly likely
that the p ilot allowed herself to be distracted to the
extent that sh e paid insufficient attention to her primary
responsibility of flying the aircraft safely, an d allowed it
to stall.
Locking the door: While the door of this aircraft may seem
locked (the latch at the top centre is in the CLOSED position) it
is not. The application of gentle pressure at the top right
corner has opened the door slightly, indicating that it was
not properly shut when the latch was closed. For many GA
aircraft applying a gentle pressure to the door as illustrated
is a useful way of checking that it is secure.
preoccupied with attending to the m al functioning
engine and in doing so failed to maintain sufficient
airspeed for safe flight. While the example here clearly
involves a more serious problem , the principle remains
the same.
Whether he is in a 747 or a Cessna 150 a pilot's
prime responsibility is that of flying his aeroplane.
Emergencies and less-dangerous inflight occurrences
must assuredly be dealt with, but never at the expense
of maintaining co ntrol of the a eroplane •
The competi tion is being sponsored by Maxwell
Optical Industr ies P ty L td , the A ustralian distributors
of N ikon cam eras and photographic equipment.
Two prizes will be awarded :
• one for the best picture having as its them e
Australian civil aviation ;
• the other for the best p icture having an Aust ralian
civil aviation safety them e.
T he prize for the best civil aviation picture is a
N ikon FE2 valued a t $650 and the prize fo r the safety
theme picture is a N ikon FG-20 valued at $360 . Both
p rizes h ave been supplied by M axwell O ptical
ind ustries.
Aviation Safety D igest Photographic Competition
Bureau of Air Safety Investigation
GPO Box 367
Comment
The Pilot's Operating Handbook for the Bonanza gives
the following ad vice for an unlatched door in flight:
If the cabin door is not locked it may unlatch in flight. This may
CANBERRA CITY, ACT 2601
occur during or just after takeoff. T he door will trail open
approximately three inches but the flight characteristics of the
airplane will not be affected, except that the rate of clim b will be
reduced. Return to the !z·eld in a normal manner. If practicable,
during the landing flare-out have a passenger hold the door to prevent
it swinging open.
Accide nts and incidents continue to happen b ecause
pilots allow themselves to be distracted by relatively
harmless occurrences. For example, in addition to doors
opening in flight, several pilots of late have taken
precipitate action because they were alarmed by the
knocking noise made by seat belts trailing outside
closed doors.
To take the issue a step further , there have been
cases of twin-en gine aircraft stalling and crashing
following an engine failure durin g a critical phase of
. flight: the pilots involved apparently became
22 I Aviation Safety Digest 123
Any number of pictures can be entered by
individuals as either colour or black-and-white
13 cm x 18 cm prin ts, or colour tra nsparencies.
Entrants should include name and address , telephone
number, make of camera, details of film, aperture,
shu tter speed and a short description of the picture on a
separate sheet securely fixed to each entry.
Entries will be accepted up until t he last mail on
24 May 1985 and should be addressed to:
The FE2 is a 'state of the art' 35 mm sin gle lens
reflex (SLR) camera a nd was judged the 1983 SL R
C amera of the Year by Australian Camera Craft
M agazine. The FG- 20 is a fully automatic 35 mm SLR
aperture-priority a uto exposure camera which also
provides a facility for manu al over-ride. Both cameras
will be equipped with a 50 mm 1.8 Nikon E lens and
an ever -ready case.
Photographers will retain copyright to their pictures,
except for the two winning entries. In addition, the
Bureau may wish to publish a number of other entries
along with the winning pictures in A viation Safety Digest
125 in July 1985 and mou n t a display .
The competition is open to all photographers with an
interest in civil av iation, with the exception of the staff
of the Bureau and Maxwell Optical Industries and their
im mediate families . Pictures can cover a ny aspect of
civil aviation - aircraft in flight or on the groun d,
a irways operations, m ainten ance or r unway facilities ,
passenger servicing etc.
T he Bureau will take all reasonable care of entr ies
submitted but cannot accept responsibility for non receipt, loss or damage. The judgin g pan el will consist
of the Editor of the Digest, another mem ber of BASI ,
and a photograph ic specialist from ou t side BAST. T heir
decisions will, of cou rse, be final •
Aviation Safety Digest 123 I 23
�
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1
BUREAU OF AIR SAFETY INVESTIGATION
122/1984
�Contents
3 Tail-draggers and crosswind landings
6 Slung load and poor visibility
When the slung load of a Bell 206 struck a mountain
slope during a forest fire fighting operation, the pilot
was saved by his protective clothing.
1'1Jil-dra9gers and no"wind landings
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It Is distributed free of charge to
Aus tralian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Austral/an civil aviation.
6 Less haste more speed
In the world of aviation the human propensity towards
unnecessary haste must be restrained.
7 Say again
A serious accident in which a Cessna 152 stalled on
final approach brought to notice an operational problem
Involving warning horns and pilots wearing headsets.
8 Set-up or self-inflicted?
It is the responsibility of the pilot to determine whether
an area he wishes to use tor takeoffs and landings can
be classified as an ALA.
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or wishing to notify a change of address should write to:
The Publications Distribu tion Officer
Department of Aviation
P.O. Box 1839Q, Melbourne, Vic. 3001
Aviation Safety Digest is also available on subscription from
the Australian Government Publishing Service. Inquiries and
notifications of change of address should be directed to:
9 Freud, Jung and all that
Reader contribution.
10 Report heavy landings
11
Air pollution
'Oxygen-breathing engines will not operate without
oxygen.'
12 Don't knock the 225
13 Helicopter Vne: what's it all about?
Helicopter Vne speeds have to be understood and
appreciated for what they are: critical aircraft limitation,
which often is not depicted correctly on airspeed
indicators.
16 Pressiny on regardless
It is essential that pilots recognise their respons ibility
to take full advantage of inflight information services
and to revise their plans if necessary. The pilot of a
Cherokee Six endangered the lives of six people when
he decided to check out inflight reports of severe dust
storms.
18 Look closely, and spot the defect
The Bureau of Air Safety Investigation conducted preflight competitions at the Canberra Aero Club Open
Day in March and the Sport Aircraft Association's fly-in
at Mangalore over Easter.
19 Churchill Fellowships
20 Heat stress
Covers
Changing styles in tail-draggers: our covers feature a
Citabria, the Saro 'Cutty Sark' and the Sopwith
'Tabloid'.
2 /Aviation Safety Digest 122
Mail Order Sales
Australian Government Publishing Service
G.P.O. Box 84, Canberra, A.G. T. 2601
Subscriptions may also be lodged at AGPS Bookshops in the
capital cities.
Reader contributions and correspondence on articles should
be addressed to:
The Director
Bureau of Air Safety Inves tigation
P.O. Box 367
Canberra City, A.C. T. 2601
© Commonwealth of Aus tralia 1984
ISSN 0045-1207
R83/1367 Cat. No. 84 0721 3
Printed by Ambassador Press Ply. Ltd.
57 Good Street, Granville, N.S. W. 2142.
Despite the proliferation of tricycle undercarriage light
aircraft, tail wheel aircraft remain popular, especially
for short or rough field operations. Many pilots are
unfam iliar with the idiosyncracies of the tail-dragger
and find a con version on to type difficult. In particular,
crosswind landings can initially prove challenging. This
article reviews a typical tail-dragger landing accident
and then discu sses the techniques a pilot should know
and use to avoid groundloops. Note that the
information given is intended specifically for singleengine tail wheel aircraft, although some of the sections
have general applicability.
The accident
A Cessna 180 pilot was fl ying an approach with a
crosswind of 10- 12 knots from the left. He crossed the
fence at his planned speed of 60 knots, then touched
down in the three-point attitude. The aircraft bounced
once before settling on the ground at 40-45 knots. The
pilot felt that he had landed successfully a nd was
allowing the speed to reduce without braking when the
left wing began to rise. He said that he h ad full leftwing down aileron and full back stick a pplied before
this happen ed and so was unable to prevent the wing
from rising; the introduction of engine power to assist
in retrieving the situation apparently was not
considered.
T he aircraft began to weathercock into wind and the
right wingtip scraped the runway. Friction from the
right tyre became sufficient to force the propeller and
spinner into the runway and the aircraft nosed over. It
came to rest inverted in a direction reciprocal to that in
which it had landed. The pilot completed the shutdown
checks and vacated the aircraft.
Inspection of tyremarks on the runway showed that
the Cessna touched down initially wi th the wings level
and drifting to the righ t. After the bounce , the
touchdown and roll had been on the right wheel.
The pilot had undergone 8 hours endorsement flying
prior to this flight but the maximum crosswind he h ad
encoun tered had been about 6 knots.
The forces
Tail wheel aircraft are generally more prone to
grou ndloop accidents than are nose wheel types
primarily because the centre of gravity is located aft of
the main wheels. Figure 1 (page 4) depicts the forces
which would apply if, for example, a n aircraft began to
swing during a takeoff or landing ground roll .
In this situation, the tendency for the aircraft to
move sideways is opposed by a n other sideways-acting
force at the m ain wheels which is generated by friction
between the tyres and the runway surface. T he fact that
the cen tre of gravity is behind the main wheels gives
rise to a yawing moment which tends to pivot the
aircraft about the m ain wheels.
G iven the distribut ion of forces shown in the
diagram, instability exists, and so the tighter the turn
the more powerful the yawing moment causing the turn
becomes. Similarly, as the distance between the main
wheels and the centre of gravity increases, the effect of
this adverse yawing moment will also increase, further
adding to the severity of the swing in some aircraft. If
the runway surface is slippery, the tyres wi ll rapidly
lose their grip and the aircraft may slide backwards; if
it is dry, the spiral may contin ue to tighten until
eventually the inside main wheel lifts and the propeller
and ou ter wingtip strike the ground.
Flying the circuit
Before discussing the specific landing method, som e
commen t on general circuit, approach and tou chdown
techniques should be made , for all of the circuit is
important - not merely the la nding. A badly flo wn
circuit makes the landing that much more difficult.
These particular commen ts are applicable to any
aircraft, regardless of its undercarriage configuration.
Circuits. Corrections must be made for a crosswind
during circuits to avoid fl yin g a n irregular circuit
pattern. Heading must be adj usted on downwind to
ensure that the aircraft flies parallel to the intended
la nding path while m aintaining the correct distance out.
Pilots must also appreciate that their groundspeed on
the crosswind leg will be different from that on the b ase
leg. They must be ready to turn on to the b ase leg
either earlier or later than norm al, depending on the
direction of the crosswind. Any miscalculation here will
make it difficult for the pilot to assess the effect of the
crosswind during the final approach , which may result
in a misjudged la nding.
The approach. H av ing a llowed for the wind during the
base leg turn , it is then necessary to track accu rately on
the final app roach. There a rc two basic method s of
compensating for drift during an approach to land out
of wind :
• by heading the aircraft suffi ciently into wind to
counteract the drift and, with the wings level,
tracking or crabbing along the in tended landing
path; and
• b y lowerin g the upwind wing and, holding on
opposite rudder to stop the turn, side-slipping the
aircraft sufficien tl y to descend in line with the
la nding direction .
Of these two techn iques, the crabbed approach is the
more straightforward method of compen sating fo r drift.
Aviation Safety Digest 122 I 3
�type of approach and landing, the pilo t compensates for
d rift on the approach by crabbi ng the aircraft into wind
and holdin g the drift correction until after the aircraft is
flared for landing. But as the speed begins to diminish
and before the ai rcraft starts to settle towards the
ground, the pilo t transitions to the slip method by
yawing the aircraft into li ne with the runway while the
speed is still sufficient to maintain rndclcr effectiveness.
T he n, when the aircra ft is tracking straight clown the
runway, the upwind wing is lowered smoothly to
prevent further drift a nd the hold-off continued unti l
the upwind wheel touches the grouiicl . After
tou chdown, the a ircraft is kept straigh t by using a
com bina tion of r·udder and upwind aileron .
Main wheel
side force
The forces shown tend to cause ground loop in tail wheel aircraft .
Figure 1
Once a crab angle suffici ent to cope with the conditions
has been established, aircraft handling, at least up to
the point of tou chdown , is quite straightforward and
similar in all other respects to a normal approach.
In the case of the side-slipping technique, however,
there arc several important considerations to be taken
into account. In many aircraft types, flight m a nual
requirements prohibit extended side-slips with low fuel
quantities because of the danger of uncovering the tank
outlets and causing engine failure from fuel starvation ,
a situation which could be extremely embarrassing at
low height. In so me aircraft , too, side -slipping with
flaps extended beyond a particular setting is not
recommended because of the possibility of shielding the
tail surfaces from the a irflow and produci ng a sudden
noseclown pitch which co uld be difficult to correct close
to the ground.
Yet an other and perhaps not quite so obvio us
shortcoming of this type o f approach is the possibility of
runnin g o ut of control. In a ver y strong crosswind ,
co nsiderable into-wind aileron and a corresponding ly
large rudder deflectio n may be necessary . In these
circumst ances, there may be insufficient control travel
rema inin g fo r the pilot to right the aircraft sho uld an
exceptionally strong g ust o r unexpected turbulence
cause an upse t near the ground.
Touchdown. Duri ng a crosswind landing, the wind
force acts over th e entire side area of the aircraft and
tends to p ush it towards the down wind side of the
r·unway . T hi s force is proportional to the square of the
crosswind velocity; thus, in a 10 knot crosswind , the
side force on th e aircraft would be quadruple that
produced by a 5 knot co mponent. Generally, the centre
of pressure of this crossw ind fo rce acts aft of the centre
of rotation (the main undercarriage) so that a yawing
mom ent which tends to make the aircraft weathercock
into wind is usuall y produced.
Undercarriages are not designed to withstand h eavy
side loads. It is imperative, therefore, that the aircraft is
n ot permi tted to contact the ground while drifting and
that at the moment of tou chdown it is al igned with the
direction of flight or travel.
As in the case of the crossw ind approach , there are
t.wo basic m etho ds of cou nt eractin g drift at the po in t of
4 I Aviation Safety Digest 122
touchdown. Both are simply extensions of the
techniques al ready described. If the crabbed approach 1s
used , the touchdown technique consists of flaring the
aircraft in the normal way, with the drift correction still
applied , and the n , as speed diminishes a nd the aircraft
begins to settle towards the runway, smoothl y bu t
firml y applying rudder to yaw th e a ircr aft into line with
the direction of flight just before it touches down. As
the ai rcraft is straightened in this way, opposite aileron
should be used if necessary to keep th e wings level.
D espite the obvious advan tages of the crabbed
approach , this exercise of ' decrabbing' immediately
before touchdown calls for a very high degree of skill
and judgment. T he p ilot must resist th e tem ptation to
alig n the a ircraft with the runway too soon or, though
still pointing in the la nding direction, it will quickl y
commence drifting towards the down wind ed ge of the
run way. Any attem pt at this stage to realign the aircraft
by making a co-ordinated turn into w ind will almost
certainly result in it st riking the ground whilst drifting
do wnwind. Conversely, if the pilot waits too long to
straighten up , the aircraft will to uch down al an angle
to the runway , su bjecting the undercarriage to the very
loads which the exercise is in tended to avoid . And even
if the pilot has correctly judged hi s height above th e
runway and st a rts to reduce the crab angle a t what he
estimates to be the righ t moment, he may still fi nd
him self in difficulties. D ecaying a irspeed during the
hold-off might wel l have red uced rudder effecti veness to
the point that , even with full ped al deflection, there
may be insufficien t control avai lable to yaw the aircraft
into line before the wheels touch the ground .
By contrast with these d ifficulties , landing off a sideslippin g a pproach does not require such p recise
judgment or timing. T he aircraft is already al igned with
the runway and after what is virtua lly a normal flare
a nd hold-off the a ircraft to uches dow n without drift o n
the upwind m ain wheel. The fact that th e upwind wing
rem ains lowered also provides some measure of
protection against strong sideways gusts.
The combin a tion m ethod. The crosswi nd lan ding
technique which probably gives the greatest degree of
co nt rol without making unnecessarily high demands o n
pilot skill is the combination crab-slip method. In this
Three-pointer or wheeler?
To rei terate, the techniques discussed under the main
heading of ' Flying Lhe circuit' are generally applicable
to all aircraft types. For the pilot of a tail-dragger, the
particular problem is that of mainta ining directional
con trol after touchdown. H ere, he must decide whether
to carry out a three-point land ing or a wheel landing.
Generally, in crosswind conditions a wheel land ing is
preferable . Note tha t for some tail -draggcrs lhis may
not be the case a nd reference Lo the P ilot's H andbook
and experienced operators should always be made. For
most types, however, a wheel landing produces the
follow ing benefits:
• The chan ge of a ttitude when landing is less and
there is no hold-o ff, so j udgment is easier.
• It enables Lhe aircraft to be flown on to the ground
. at a higher tha n no rmal speed, which can be an
advan tage in ad verse wind cond itions.
• It is a safer way of landing a heavily laden aircraft.
The main disad vantage of a wheel landing is that it will
entail a longer la nding run .
Three-point. If the three -point technique is used, the
pilot must be ready to quickly counter any
weat hercocking tendency on the ground by rapid, and
coarse if necessary, u se of rudder and judicious
application of brakes. Afte r the aircraft has settled on
the ground, holding into-wind aileron will help prevent
the upwind wing from rising in strong gusts.
An importa nt po int lo make here is that if the
aircraft bounces excess ively on touchdown, it is almost
always preferable to go around and start again rather
than try to recover from the bounce.
Wheel landing. Again, once the ai rcraft has settled on
the ground , the pilot m ust be prepared fo r rapid, and
perhaps coarse, use of rudder to keep the aircraft
straight; while into-wind aileron w ill again be
necessary. Brakes should be used judiciously as the tail
wheel is lowered to the ru nway . Note that the tail wheel
shou ld not be forced o n to the ground, as premature
backward m ovemen t of the control column may cause
the a irc ra ft to become airborne or may red uce the
airflow over the rudder at a speed too high for the
brakes to be used effectively, i.e. directional control
wou ld be seriously restricted.
General technique
As a general rule it is preferable to carry out powered
ap proaches in crosswind conditions. The use of power
helps to regulate the rate of descent over a very wide
range to compensate for varying w ind strengths. It also
results in a smaller change in attitude during the
landing flare compared with that for a full-glide
approach . Slipstream, and hence rudder effectiveness, is
enhanced by the use of power; however, the throttle
should be closed smoothly Lo prevent any sudtlen
yawin g as power is reduced. As speed decreases, so too
will aileron and rudder effectiveness.
Often there is d iscussion on the mer·its of attempting
to offset the crosswind effect by aiming to land near the
downwind side of the runway in anticipation of
weathercocking; or conversely, aim ing for the upwind
side in anticipation of drift.
Careful thought should lead to the conclusion that
both of these practices are questionable . All things
considered, it is far better to adhere to established
techniques and to aim to touch down about the normal
distance in from the threshold as near as possible to the
centreline.
For instructors and supervisors
The accident reviewed at the start of this article was
one of several instances in a short period of tail wheel
aircraft grnundlooping. Accordingly, data on these
occurrences over a 6 year period were researched from
the Bureau of Air Safety In vestigation's computer
records .
I n pa1·ticular, pilot hours on type were related to
their total experience.
I t was found that over one-third of the accidents
involved pilots with less than 12 hours on type while
half of the accidents involved pilots with less than
600 hours total experience. T he experience area of up
to 12 hours on type and 600 hours total therefore
con tains a disproportionate share of accidents.
T his does not mean that pilots who fall outside those
parameters are immune from groundlooping
occurrences. What it docs mean for instructors and
supervisors alike is that pilots who do not meet those
experience criteria and who wish to fly tail wheel
aircraft should be given:
• close supervision; and
• a large proportion of dual instruction during their
fi rst 12 hours on type.
Practice
Precise judgment is requ ired to estimate height and
drift angle in crosswind conditions and a h igh degree of
co-ordination is necessary to correctly align the aircraft
with the touchdown direction. These skills can be
maintained only by regular practice.
Maximum crosswind componenLs are normally
specified in the aircraft Hight manual. T hese values are
generally based on tests carried out by the
manufacturer and represen t the maximum crosswind
values at which the aircraft has been dernonstraLed, in
dry conditions, to possess satisfactory handling
qual ities . Such demonstrations are usually conducted by
test pilots and the results may well be regarded as being
a limitation for the type. P ilots should therefore exercise
discretion in strong crosswind conditions to ensure that
operations are confined to crosswinds within their own
capabil ities a nd to accept that this may be significantly
less tha n the crosswind component referred to in the
flight manual •
Aviation Safety Digest 122 I 5
�-- ---~E=:
Slung load and poor visibility
The accident described below occurred overseas and
involved a Bell 206 helicopter carrying a slung load.
Although the occurrence specifically relates to a fire
fighting operation, the safety lesson it contains is
relevant to any pilot m anipulating a slung load in
conditions of restricted visibility. Also of great
significance are the comments on the value of the
protective clothing worn by the pilot.
*
*
*
The helicopter was engaged in dropping foam during a
forest fire fighting operation. The fire was well
established with a circular 600 metre fire front
advancing up a valley, the end of which was
increasingly steep. Because of the profusion of smoke
and the nature of the terrain, the fire fighters were
dealing with the upwind side of the fire, leaving the
downwind and rising-terrain section burning fiercely
with heavy smoke up to 200 feet AGL. This was the first
occasion on which the helicopter's foam fire fighting
system (which was slung beneath the aircraft) had been
used operationally, and the first time that the pilot had
witnessed the fu11 effect of smoke. As the smoke was
drifting forward of the flames, the pilot decided to drop
the foam immediately on the fire front, over which the
air was clean. Two drops were made uneventfully, at
low altitude and at a speed of up to 85 knots, as per the
approved procedure. However, while climbing away
after the third drop , the Bell 206 p assed through the
smoke from the flanks of the fire. This smoke was
obscuring higher ground. The bucket, still attached to
the helicopter , struck the mountain slope at speed,
causing the aircraft to fly into the trees. Although
substantially damaged, the helicopter 'glanced' back
into the air with what appeared to be a jammed yaw
control and an u nresponsive cyclic stick . The pilot
immediately attempted a landing onto a relatively even
area. However, on touchdown the aircraft rolled heavily
onto its starboard side, and further damage occurred
before the pilot shut down the engine. Both front doors
had jammed but, aided by the fact that h e was wearing
gloves, the pilot was able to punch a door window out
without hurting himself, and vacate the aircraft.
Gloves were not the only important protective clothing
the pilot was wearing: to quote the accident report,
' His life was saved, w ithout doubt, due to the wearing
of a "Bone Dome" flying helmet which took one blow
to the right side of the head from the door pillar on
impact' .
*
*
*
In the event the pilot escaped injury-free. H is
experie nce should be a salu tary one for all those
involved in high-risk operations e
Less haste more speed
W e are rarely in as much of a hurry as we think.
Ask yourself the question: ' H ow often have the few
minutes I saved by cu tting a corner here, or shortcircuiting a system there, been really important?'
The odds a re that in the overwhelming majority of
cases an h onest an swer will be that those minutes
were not at all impor tant . Yet aircraft accidents
continue to occur becau se of n eedless haste.
*
*
*
An agricultural pilot had been operating all day from
a strip which was align ed north-west/south-east.
Becau se there was a power line across the SE end , the
pilot had been u sing the strip one way only, taking
off to the NW and landing into the SE .
At the conclusion of sprayin g the aircraft was
refuelled for the ferry fligh t back to its home base.
The a ircraft was now relat ively light and, as home
base was away to the SE, the pilo t decided to takeoff
for the first time th at day in that direction:
apparently he d etermined his a ircraft would have
sufficient performance to clear the wire.
Almost immedia tely after becoming airborne the
pilot diverted hi s attention to wave to one of the
ground party and forgot about the power line . The
aircraft stru ck the wire with its left wing, just
6 I Aviation Safety Diges t 122
inboard of the wing strut. Realising h e still h ad some
control remaining, the p ilot attempted to put the
aircraft back on the ground . He did so su ccessfully
but the aeroplane was substantially damaged.
Comment
Clearly the fact that the pilot a llowed himself to be
distracted and forgot about the p ower line
contributed to this accident. No doubt fatigue - he
had been on duty for 11 Yz hours - a nd
complacen cy at the end of a long d ay's work were
also facto rs in his forgetting about the power line.
The p roblem really star ted , though, when he decided
to save one or two minutes by taking off on the
headin g of his track instead of continuing to use the
safer takeoff direction away from the wire.
Human n ature often seem s disposed towards
unnecessary h aste. Unfortunately, far too often it
just creates problems as important checks are
overlooked, safety procedures ignored, standards
compromised .. .
For av iators in particular, needless haste can be a
catalyst for disaster. As was said at the start of thi s
article, we a re rarely in as much o f a hurry as we
think - certainly not a t the possible expense of our
lives e
-==
..=.=
=E -
i
- ==-== =
EE~=
Warning systems are placed in a ircraft for a very good
reason - to alert us to the danger that something is
happening, or may be about to h appen , that we don't
want to happen! In m ost instances the warning acts as a
trigger to remedial action . For example, if a stall
warning h orn sounds we lower the aircraft's nose, level
and unload the wings, apply power, etc.; if an overvoltage warni ng light illuminates we follow checklist
actions in an a ttempt to restore generator/alternator
power; if an OFF flag appears on an instrument we
again fo ll ow the recom mended procedures to find out
why; and so on.
It follows, then , that when a warning system is
activated, the pilot needs to know about it.
A serious accident in which a Cessna 152 stalled on
final approach brought to notice an o perational problem
involving warning horns and pilots wearing headsets.
The accident
A student pilot was authorised for a solo period of
circuits. During the fou r th approach, he assessed that
he was too high and attempted to regain the correct
flight path.
At 65 knots indicated airspeed, and with full flap (30
degrees) selected, h e raised the nose to slow the aircraft
and attem pted to set up a higher rate of descent using
the extra induced drag. H e held this n ose-high attitude
withou t monitoring the airspeed indicator. The a ircraft
began to buffet and, at an altitude between 200 to 400
feet AGL, the left wi ng dropped and the Cessna entered
an incipient spin . R ecovery was effected at about 10
feet AGL on a heading 180 degrees off the runway
direction.
H owever, the aircr aft 'reared up' to a nose-high
at titude again with full power applied. It was levelled at
the approximate height of t he first stall when another
stall occurred. Again , the left wing dropped , but this
time the aircraft rotated through some 360 degrees and
then struck th e ground in a nose-low attitude . The right
wing and undercarriage absorbed the main impact.
When the wreckage came to rest, the pilot - who
sustained only mino r injuries - u ndid his full harness
and exi ted rap idly . The aircraft was destroyed.
Discussion
Clearly, cer tai n aspects of the pilot's flying technique
were deficient at this early stage of his training and this
matter was add ressed d uring the investigation. W hat is
of interest here, however, is the fact that at no stage
d uring the occurrence did the pilot hear the stall
warn ing horn blowing. If he had, then doubtless
corrective actio n would have been initiated before the
stall was allowed to d evelop.
I t tran spired that the p ilot was wearing a headset
over both ears . This h eadset was particularly effective
in reducing u nwan ted cabin noises. Unfortunately, it
also suppressed the sound of the stall warning horn .
The use of headse ts in GA aircraft is recommended
by the Departmen t of Aviation. Not only does a
headset usually make radio/navaid reception clearer and
easier but, if fi tted with a boom microphone, also
removes the necessity to d ivert one hand to operating a
hand m icrophone.
However , if a headset suppresses external sounds that
need to be heard, then something needs to be done
about it.
Some headsets currently available are claimed to
mute unwanted noises while still allowing normal
conversation with both ears covered. Other sets,
however, seem to block all external noises with both
ears covered. Thus, over the years, many pilots have,
as a matter of routine, flown with one ear uncovered so
that warnings will be heard.
I t is interesting to note that the assessment of level
for aural warning from discrete sources has always been
a contentious subject. Attempts have been made to
adjust levels using instrumentation but this has been
generally unsuccessful, and even a ircraft as recent as
the Boeing 767 have the levels set subjectively .
Accordingly, the need to react to sounds emanating
from discrete sources has been addressed by wearing
headphones over one ear. For example, the
Specification for Ground Proximity Warning devices is
stated as follows : 'The audio warning level should be
assessed under conditions of . . . approach speed with
one ear uncovered by the headset used in that aircraft
type'.
Summary
The crucial point arising here is that if an aural
warning system - stall, undercarriage, GPWS etc. - is
activated, then you need to be able to hear it so that
remedial action can be initiated. If you use a headset,
then take a couple of minutes to check whether you can
hear external warnings clearly with both ears covered.
If not, then obviously you need to fly with one ear
uncovered at least during those phases of flight - e .g.
approaches, circuits - where the workload is high,
your !AS low, you must have your wheels down, and so
on.
It's a small check to make in terms of time and
effort, but it could be invaluable •
Aviation Safety Diges t 122 I 7
�~eade't
Set-up or self-inflicted?
It is the prerogative of any licensed pilot to decide
that an area he wishes to use for takeoffs and
landings can be classified as an Authorised Landing
Area (ALA). In exercising this prerogative it is the
pilot's responsibility to ensure that his planned
operations and the ALA standards comply with those
specified in the Visual Flight Guide (VFG). While
these requirements are fairly straightforward and
exist solely to try to ensure safe operations, they are
unfortunately far too often overlooked or ignored,
which in turn can lead to an aircraft accident when
an ALA proves to be inadequate for an intended
operation.
Before flying in to an ALA a pilot needs to know its
physical dimensions, the condition of the landing
surface and the location of any obstructions. An ALA
also should have a suitable indicator of the wind
velocity. Given that ALAS are sometimes used for
purposes other than aircraft operations - for example,
livestock grazing - it is clear that the best way for a
pilot to confirm the conditions al an ALA is to contact
the owner.
In the acciden t account that follows, some readers
may feel that the pilot concerned took all reasonable
steps to determine the suitability of the ALA he wished
to use ...
A tradesman was planning to fly to a property
homestead to carry out some maintenance. Before
departure he decided to refer to a strip register which
had been compiled locally by a flying organisation .
None of that organisation's pilots was available lo talk
to at the time, so the tradesman checked the register by
himself. It advised that strip 17 /35 was preferred at the
particular ALA; no other comments were made.
The flight out to the homestead was made in a
PA28R-200. On arrival in the circuit area the pilot saw
two clearly defined strips - the second was 12/30 marked by white painted tyres. A dirt road was visible
running parallel to 12 and crossing 17. It appeared level
and the pilot assessed that it would not affect the ALA.
As the wind was a southerly at 5-10 k nots he elected to
land on 17.
The pilot landed long because of a tree near the
approach end. A smooth touchdown was made on the
main wheels. Shortly afterwards a i;dge of dirt across
the strip ahead of the aircraft was noticed, and as the
Arrow ran over the ridge a loud impact noise was
heard. Notwithstanding the noise, the pilot did not
consider the impact severe. At the completion of the
landing roll he taxied back and observed that the ridge
was associated with grading on the road across the
strip.
It was subsequently found on return to base that the
aircraft had been substantially damaged. Bulkheads had
crumpled and the right wheel had been pushed back,
while the right wing had buckled ribs and wrinkled
skin. There were also popped rivets in various places.
Unfortunately, the strip register the pilot had
consulted prior to the flight was out-of-date. The
organisation which compiled it had another, current,
register of which its regular pilots were aware, and
8 I Aviation Safety Digest 122
which stated that 17/35 at the ALA in question was
'NOT USED'. It was also unfortunate that the white
tyres delineating 17 /35 were visible from the air.
Apparently they had not been so for some time
previously, having been overgrown. However, because
of a recent drought, the undergrowth had died and so
from the air it seemed as though the strip was usable.
It could, then, perhaps be argued that this pilot was
to some extent 'set-up' by the out-of-date register and
the slrip markings. On the other hand, the pilot had
not observed the recommended practice for ALA
operations of contacting the owner to determine the
current status of the ALA. Further, he did not take the
opportunity to speak to one of the professional pilots
who operated into the ALA. Had he taken either of
these actions, the accident presumably would not have
happened.
Following the accident investigation, the out-of-date
register was amended, and it was suggested to the
property owner that he remove the tyres' marking out
17/35.
•
*
•
There was an interesting postscript to this accident.
Following the impact on landing, the pilot stated that
he made an inspection of the aircraft, particularly the
undercarriage. No signs of damage were noticed. After
he completed his work at the homestead he carried out
a 'normal walkaround', was again satisfied that
everything was all right and then flew back to his
original departure point. While the gear seemed to
retract normally the 'in-transit' light remained on. It
was only after landing at home base that the serious
damage was apparently noticed.
As the photograph shows, the wrinkled s kin on the
right wing is quite obvious. The wrinkling is indicative
that something h as happened to the structure beneath
the skin, and that the structural integrity of the aircraft
may be at risk.
It should never be necessary to have to stress the
importance of preflight inspections •
reud, ung and all that
' The p ilot continued into weather cond itions . .. ' How
many times have we read it in the Digest? As the editor
once said, the story has been repeated ad nauseum. We
usually read, too, that the unfortunate pilot probably
was the victim of the 'it-can ' t-happen-to-me' syndrome .
The same pilot who bought it for himself a nd his
passengers by flying into high ground after a nice old
spell in stratus trying to fly !FR may well have been
experien ced, conscientious, and without a desire to
com mit suicide . He was, of course, under the influence
of an urge 'to get through ' ; or perhaps had a bad case
of 'get-home-itis' .
Yet, have we solved the mystery? Arc these the sole
cau ses of the fatal weather-related accidents? Can we
fully guaran tee our own safety: (1) by realising it
actually can happen to u s; (2) by not trying to 'get
through'; and (3) by ignoring our 'get-home-itis'
symptoms? We can't. We can, but we can 't.
Somebody said something about it in the Digest a few
years ago . It was a reprint from America, and to me it
h it the spot. It was all to do with programming the
subconscious mind. The well-known French
hypnotherapist Emilie C oue wrote about it back in the
1920s in his 45 page book Better and B etter Every Day. H e
described the differences between the conscious mind
and subconscious mind, and laid down these rules:
firstly, the conscious mind passes all information to the
subconscious, which naively believes it; secondly, the
more the information is stressed or repeated the m ore
the subconscious believes it, and is likely to act on it;
thirdl y, the subconscious is the boss. Any attempt by
the conscious to go against what the subconscious
believes will cause the su bconscious to rise up and
overwhelm the conscious, even if it means ca using its
own death.
Coue cited an example. If you place two house bricks
on the ground, put a long plank on them, and invite
yourself to walk the plank without falling off, you
should pass the test. Fit the same plank at twenty
storeys across two high-rise buildings in zero wind
conditions, a nd try walking across again. Whether or
not you get halfway there and fall to your death will
depend o n how your subconscious is programmed. If,
as a result of you r experience with the plank on the
ground, you have told yourself you can walk across at
any altitude, and you have no fear of falling off, you
will walk to the other side. If you have a fear of falli n g
off but think you can make it anyway, you will
probably walk part-way, get wobbly, drop to your
knees, and finish the job by crawling across.
If, however , you have a strong fear of falling off,
have told you rself ' I 'll fall off that pla nk if I try to cross
it', but nevertheless force yourself to do it, your
su bconscious will cause one of your knees to buckle,
your hand to go numb as you try to grab the plank,
a nd your body to fall to its death .
The more you try to go against what your
subconscious believes, the stronger the subconscious
makes that belief happen, even to the extent of cau sing
its own death . Such is the power of the subconscious,
says Coue.
When most of us plan a fli ght from A to B, we
program our subconscious to get to poi n t B. We usually
have n o doubt about getting to B. All our thoughts and
expectations are of a positive nature; we think only
abou t ge tting there, and work out how to do it. We
rarely plan to gel part-way there and turn back.
This, therefore, is the reason why so many of us push
our way through marginal or sometimes even quite
lethal conditions, and on miraculously arriving at our
destination tell ourselves we were stupid to h ave done it
and there was no real need for us to have tried. We
were lucky this time. Yet, zingo, what happens but next
time we do exactly the same thi n g again ! In my 1200
hours of private flying I' ve done it at least four times ,
though these days it' s never again.
When we reach marginal conditions, to the point
where we should be turning back, our subconscious tells
us to keep going. We are programmed to get to B, and
that is where we must try to get. We can 't help
ourselves.
A friend of mine described a similar experience when
driving his car into the city centre. Before he started the
motor he got out his street di rectory and worked ou t
what inner city streets, including one-way streets, he
had to negotiate; and how to turn eventually to the
right down a Janeway. When he got to the laneway
after following his ' flight plan ', he fou nd a policeman at
the Janeway intersection di recting all traffic to go
straight ahead. My friend couldn 't help himself; he had
a powerful urge to turn down the Janeway, and he
turned. When the policeman came over to him, he
said: 'Just book me, onicer; I know you didn't wan t
me to turn in here, but I couldn't help myself. I had to
turn because this is where I planned to go.' The
policeman must have read his share of Freud or C arl
Jung because he let him off.
All right, what do we do to stop our own
subconscious minds from wiping us out one day in bad
weather condi tions? The answer is: we p rogram
ou rselves to turn back. Before we submit our fligh t
plan, we look it over for likely turn-back points and tell
ourselves: 'If I run into marginal conditions about
there, I'll turn back. ' Before we start the engine, we tell
ourselves: 'If I run into marginal conditions anywhere
on th is flight, I'll turn back. ' That's all we have to do.
Any pre-flight planning that programs the pilot 's
subconscious mind to make a timely diversion when
things get rough may well save his life, the lives of h is
passengers, and a good aircraft to boot •
Aviation Safety Digest 122 I 9
�Report heavy landings
All of those occur rences are consistent with a heavy
land ing.
Followi ng the d iscovery of the damage, the strip at
the resort was examined and three propeller slashmarks
were fo und 147 metres from the threshold.
Comment
Clearly, the daily inspection prior to the return flight
was inadequate, for the only abnormality the pilot
noticed was the buckled fuselage. Equally clear is the
fact that in the ligh t of the total damage the landing
mu st have been heavy; indeed, to the extent that the
pilot sho uld have been seriously concerned .
There have been several instances in the past where
Australian GA a ircraft have had their flight control
systems adversely affected by heavy landings. In this
instance , the buckling of the firewall could well have
deprived the pilot of elevator control by displacing
elevator control pulleys. T he propeller damage also may
have led to a ca tastrop hic failure .
I n sho rt, the pilo t's assessment that the damage was
minor , and his decision to fly the a ircraft home, could
have had tragic co nsequences.
I t is vital that pilots report any hea vy landing so that
the aircraft concerned can be inspected for possible
h idden damage befo re it is flo wn again. The
consequences of a heavy landing can be far reaching.
After an uneven tful tran sit flig ht to a holiday resort, a
p ilot entered downwind for landing in hi s Cessna 182.
Condit ions were clear with a 15- 20 knot wind gusting
slight!y across the strip . J ust as the Cessna was turning
on to final approach the p ilot's w ife, who was in the
front right-hand seat , drew h is attention to one of the ir
children in the rear who was about to vomit. The pilot
attempted to locate a sick bag to pass to the child . T his
was eventually accomplished when the aircraft was on
sh ort final.
At this stage the pilot noticed that the airspeed was
abou t 75 k nots. As he was intending to fly a short-field
app roach and landing, this was a bout 10 knots faster
than the ideal. Full flap had already been extended, so
he closed the throttle to idle powc to reduce the speed.
Shor tly afte r power was reduced the aircraft sank
rapidly and contacted the ground nosewheel first. The
aircraft bounced two or three times and was brou ght to
a stop about two-thirds of the way down the 815 -metrelong sealed r unway and then taxied to the parking area.
T he pilot helped h is famil y out of the a ircraft and to
their overnight accommodation . By the time he was
able to return to the 8essna to tie it down it was after
dark. Thus, the external condition of the aircraft was
not readily apparent to hi m . In any case, he late r stated
that he had not co nsidered the landing exceptionally
heavy a nd had no reason to suspect that there would
h ave bee n a n y damage.
The a ircraft rem ained ti ed down fo r a cou ple of days
until the fami ly a rrived for the return flight. D u ri ng hi s
dail y inspection, the pilot noticed that th e fuselage was
buckled on the lo wer left- hand side behind the en gine
cowling . H e assessed this as being only m inor d amage
and flew the a ircraft back hom e.
It was subseq uently discovered that during the
landin g at the resort the Cessna had sustained serious
·da mage:
10 I Aviation Safety Digest 122
•
•
•
•
The firewall was compressed and buckled.
The nose wheel outer left-ha nd rim had a flat spot.
Both propeller blades were ben t back and abraded .
There was bucklin g on the left-h an d side of the
forward fuselage.
• The nose wheel strut seals had r uptured , a llowing
the strut to gradually deflate.
Assessment
Assess ing whether or not a landing has been heavy can
be diffi cult; as there are no exact criteria by which the
factors involved can be measured, the decision will be
partly subjective . H owever, consideration of,the
following factors should serve as a guide:
• Was the rate of descen t before touchdown
substantially greater than normal ?
• W as the aircraft a llowed to 'drop' on to the runway
from a greater height than is normal?
• Was the tou chdown made on one undercarriage leg
with a high sink rate or with d r ift on?
• Were there sign ificant g-forces developed on
touchdown?
Conc lusion
No pilot likes being associated with a heavy landi ng.
H owever, the possible embarrassment notwithstanding,
it is essential to report any such occurrence, in fairness
both to yourself and any other pilot who may
subsequently fl y the aircraft.
Because the damage can sometimes be difficult to
detect, making a formal report will ensure that the
aircraft is inspected by a LAME before it flies again.
If you are not sure whether or not a landing was
heavy, report it. T o do so is good airmanship and in
everyone's best interests •
Air pollution
A Bell Jet Ranger was tracking towards a power
station at 600 feet AGL and 60 knots while carryin g
out aer ial photography. It was 100 feet above the top
of the station's twin chimneys.
As the aircraft approached the most northerly of
the ch imneys and reached the edge of their visible
emissions, the pilot noticed a smell of acrid gas. At
the same instant the helicopter's engine lost power.
Because of the height, an air restart was not
a ttem pted. A successful auto-rotation was completed .
Analysis
Compression deformation of firewall.
R esearch revea led that the emissions from the power
station contained plenty of carbon dioxide, nitrogen
a nd water vapour, varying amounts of sulphur and
nitrous oxides - and precious little oxygen. There
was nothing mech anically wrong with the engine: it
had simply been starved of the all-important 0 2.
Comment
Most readers will recall the engine power loss
suffered by a B747 some time ago when it flew
through a volcanic cloud over Indonesia. As the J ct
Ranger's experience showed, it is not o nly volcano
clouds that can cause engine respiratory problems.
Pilots are well advised to give emissions fro m
power stations a nd the like a wide ber th. The
comme nt of a specialist who reviewed this incident
summed u p the p roblem succinctly: ' Oxygcnbreathing engines will not operate without
oxygen' •
Propeller blade damage not noticed by pilot.
Aviation Safety Digest 122 I 11
�Aircraft accident reports
Don't knock the 225
SECOND QUARTER 1984
The fundamental objective of air safety investigation is
the prevention of accidents and incidents . Investigations
aim to determine all the factors involved and to use this
information as the basis for enhancing safety in
aviation.
One important medium throu gh which air safety
investigators receive safety-related information is the
Department of Aviation's Air Safety Incident Report
(Form 225). These forms offer all individuals associated
with the aviation industry the opportunity to bring to
attention infor mation which , when analysed and acted
upon , could conceivably save lives and aircraft.
Yet it is an unfortuna te fact that, within some
sections of the industry , the ' 225 ' is looked upon as a
means by which one ' dobs', or is '<lobbed' , in to
officialdom.
This is n ot the case: the sole purpose of the 225 is to
serve as a constructive aid to flight safety . An example
of the positive use to which the form can be put was
illustrated by a Boeing 727 pilot, following an incident
during a takeoff from Coolangatta .
When the 727 was abou t one-third of the way down
the runway on the takeoff roll , a 'severe thump' was
felt throug h the aircraft. Concerned b y the force o f the
impact the pilot m ad e inquiries and found that it had
been caused when the aircraft 's unde rcarriage had run
over a temporary ramp at the end of a new overlay on
the runway . This ramp was associated with works in
progress on the runway.
The 727 captain found out that the rampin g was
within the s tandards laid down for such works. He also
disco vered that another RPT pilot had experienced the
' thump ' but considered it ' not too bad ' . N everthele~s,
the 727 captain r emained unsatisfi ed and so submitted
a Form 225 to the Department of A viation , st ron gly
urging a review of the existing ramping standards.
An invest igation of temporary ramping standards had
been going on in the Departmen t for some time.
Info rmation from the 225 report was just the sort of
feedback the D ep artme nt needed. An analyis of the
B727 's Flight D a ta Recorder showed th at the aircraft
had susta ined vertical accele rations of - 0. 5 g to
DEPARTMENT OF TRANSPORT
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PRELIMINARY REPORTS (The fol lowing accident s are sti ll under investigation)
Date
Time
NOTE-lf1ou 4niR an &f1...-~t111or 11\U l"OPU't. plna pi.au ) 'Otll' ......,. and addnu hU1'imdQ'. II llwH dftalll an Dat chm,
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ramp.
This information con tributed to the decision to revise
the standard and an A ir ports Instruction was issued,
improving the requiremen ts fo r tem po rary r amping
during resurfacing wor ks .
As the closing m inu te on the Bureau of Air Safety
Investigation 's file on this inciden t stated , ' . . . the
r esults arising from the investigation o f the pilot's
repo rt graphically illustrate the worth of t he inciden t
r epo rting syste m ' •
12 I Aviation Safety Digest 122
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
05 Apr
Cessna A185-F VH-S FS
Non-commercial - business
C1N , P1 F, P2N
0643
Cairns, Old . 26NNW
Cairns, Old./Stanley Island, Old.
8411019
Abo ut 12 minutes after takeoff, the pilot reported that the engine was malfunctioning . It subsequen tly lost power completely and
the pilot was commit ted to a forced landing. The sea cond itions were unsuitab le for the a ircraft type, with s trong wind and a 1.5
metre swe ll. The ai rcraft s ank a lmost immediately after touchdown and no trace has since been found of the aircraft or one of the
occ upant s.
05 Apr
Piper 25-235 VH-EH R
Aerial agricu lture
C1N
0640
Pittsworth, Old. 8SSW
Pittsworth, Old./Pittsworth, Old.
8411018
In company with a member of the property owner's fami ly, the pi lot had conducted a ground su rvey of the area to be treated. He
was not made aware of the presence of a reinforcing me sh grain silo, about 2 metres high and camouf laged by the colour and
hei ght of the s urrou nding grasses. On a subsequent spray ing run the aircraft collided with the s ilo, the right gear was dis lodged
during the e nsu ing gro und Impact and the aircraft s lid to a halt 102 met res from the si lo.
06 Apr
Th orp T18 VH-RWT
Non-commercia l- pleasure
C1M, C1N
Berw ic k, Vic.
Mangalore, Vic./Be rw ick, Vic.
1810
8431012
The a ircraft owner was fl ying the aircraft under the supervis io n of the pilot-in-command. A landing was made on the grass to the
south of the gravel strip. After a small bounce on initial touchdown, the aircraft landed firm ly and the right wheel penetrated the
ground to a depth o f a bout 5 cm. The a ircraft tipped forward, the propel ler s truck the ground and the a irc raft overturned.
07 Apr
Cess na 180J VH-S HX
Non -commercial- pleas ure
C1N, P1N
1610
Mt Barnett, WA
Derby, WA/Mt Elizabeth, WA
8451009
After a flight time of 70 minutes, wit h a planned fuel endurance of 140 minutes, the eng ine fa iled and th e pilot was committed to a
forced land ing o n rock covered terrain. Ev idence of a faulty fuel cap an d fue l leakage past the cap was found.
11 Apr
Romaini an IS-28B2 VH-GVZ Inst ructional- dual
C2N
1555
Benalla, Vic.
Benall a, Vic./Benalla, Vic.
8431013
Thermal act ivi ty was reduc ing rapidly fol lowing the developmen t of a high cloud laye r. When the glider had descen ded to 1150
feet ag l, the student was asked to return for lan ding. The inst ructor la ter took control and planned a short c ircuit in the poor conditions. When the s trip could not be reached, a landing was made in a paddock outside the aerod rome and the glider's left wing
struck a fence.
Pilot knowledge should be shared
A r ecen t accident which resulted in an a gricultural
aircr a ft h aving its right-ha nd la nding gear ripped off
in a hole has highlighted the need for pilots and their
companies to share knowledge of strip conditions .
It appear s tha t som e weeks after the accident , the
pilot asked the agent who ha d organi sed the job on
which he had been engaged whether the owners had
r epaired the strip . To his am azem ent , he was
The fo ll owing information has been extracted from acciden t data f iles maintained by t he Bureau of
Air Safety Investigation. The intent of pub li shing these reports is t o make available informatio n on
Australian aircraft accidents from which t he reader can gain an aw aren ess of the c ircu mstances and
conditions which led to the occ urrence.
At the time of publication man y of the acc idents are stil l unde r i nvestigation and the informat ion
contained in those reports must be cons idered as prel imi nary in nat ure and possi bly s ubject to
amendment when the investigat ion is f inalised.
Reade rs shou ld note that the informat ion is provided to promote aviat ion safety - in no case is it
intended to imply blame or liabi lity.
Note 1: All dates and t imes are local
Note 2: Injury class ification abb reviations
C =C rew
P = Passengers
0 =Ot hers
F =Fatal
S =Se rious
M = Minor
N =N il
e.g. ~~s ..P2M means 1 crew member received seri ous inj ury and 2 passengers re ceived minor
iniunes.
ad v ised that a pilot fro m his com pany had previously
con demned the str ip and refused to u se it b ecause of
its substandard condition . The agen t had then
organ ised a noth er pilot from the same compan y to
undertake that task.
In the event , three pilo ts' lives were p ut a t risk ,
one n ar rowly avoiding injury, despite the fac t tha t
the owner, the agen t and the compan y ap paren tly
knew o f the h azard e
21 Apr
Cessna 210 VH -RHK
Non-commercial - pleasure
C1 N, P3N
1340
Port Macq uarie, NSW
Bankstown, NSW/Port Macquarie, NSW
8421019
When the landing gear was s e lected down it failed to ex tend. The pilot attempted unsuccessfu lly to ex tend the gear using the
emergency sys tem a nd by the application of g-forces. Touchdown was made with the main gear up and the nose gear part ially
ex te nded. The filter in the landing gear hydraul ic system was found to have a cracked hous ing and all the oil in the system had
been lost.
22 Apr
Be ll 2068 VH-UTS
Non -commercial-corporate/executive
C1 N, P3N
1050
Nunawadi ng, Vic.
Channel 10 Helipad/Heyf ield, Vic.
843101 4
Du rin g the takeoff, the engine instruments were checked whi le the hel icopter was in a hover and no abnormalities were noted.
Just as forward moveme nt was commenced a loud no ise was heard and a ll engine power was lost . A sign ificant drop in rotor rpm
occurred before land ing. Inspect ion revealed a total mechanical fa ilu re of the eng ine compressor.
Aviation Safety Digest 122 I i
�PRELIMINARY REPORTS (The fol lowing acc idents are still under investigation)
PRELIMINARY REPORTS (The fol lowing acc idents are sti ll under invest igation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
Non-commercial-pleasure
C1N, P2N
27 Apr
Piper PA32·300 VH-JGH
Wee Waa, NSW/Bingara, NSW 9SW
8421020
1630
Bingara, NSW 9SW
The strip had been recently graded by heavy earth movi ng equipment which the passengers were to inspect. Before landing , the
pilot carried out a strip inspection from 50 feet. After touchdown, the pilot was allowing the aircraft to decelerate without the use
of brakes when a soft, graded area containing numerous hidden boulders was encountered. The right main gear leg became
detached from the wing and the aircraft came to a hal t resting on the right wingtip.
Bell 47-G3B1 VH-CSE
Mable Downs, WA 12N
Activities associated with aerial agriculture
Packsaddle Plains, WA/Mable Downs, WA
•
Non-commercial-pleasure
St Arnaud, Vic.JS! Arnaud, Vic.
C1S
8431015
21 May
Unknown
Cess na 182G VH -DJN
Townsvil le, Old.
22 May
1640
Cess na 1820 VH-FRV
Longreach, Qld. 145W
Non-commercial-aerial mustering
Ve rgemont Sin., Old./Vergemont Stn., Old.
C1 N
8411026
The pilot reported that his approach to land towards the north-west was good; however, the aircraft floated for some distance
before touch ing down. As the aircraft landed the sun appeared from beh ind a cloud and the pilot lost all forward vision. Braking
was _
applied, but as the pilot cons idered that the aircraft was not slowing down and he was aware that the strip end was near, he
applied power to go-around. The aircraft failed to become airborne and collided with a bush and a fence beyond the end of the
strip.
Cessna 1820 VH-WMF
Trentham, Vic. 5N E
Non-commercial - pleasure
Quambatook, Vic./Moorabbin, Vic.
C1 F, P2F
8431016
Cessna 150L VH-DNE
Pi nnacles Sin., WA 8NW
Non-commercial-pleasure
Pinnacles St n., WA/ Pinnacles Si n., WA
C1 N
8451012
The aircraft was bei ng used for sheep spotting. Three hours had been flown since the last refuelling and t he pilot noted that the
fuel gauge was indicating close to empty. He considered that enough f uel remained for a further 40 minutes· however 5 min utes
later the eng ine stopped. During the ensuing forced landing, two trees were struck and the aircraft sustained' substant'ial damage
to both wings and the tail sectio n. Less than 3 litres of fuel was subsequently drained from the fuel system.
27 May
1600
Quickie 02 NOT REG
Warnervale, NSW
Test
Warnervale, NSW/Warnervale, NSW
C1 N
8421026
The pilot h_ad finished construction of the ai rcraft and was conducting ground handling trials. He reported that on the final taxi ing
te_st the a1 rcr~ft suddenly became airb~rne. There was insufficien t strip length remaining to safely land again and the pi lot
climbed the aircraft to 2000 feet and earned out handling manoeuvres before returning to land. The aircraft landed heavily and the
right canard was fractu red.
12 May
Cessna 210N VH -TFC
Charter-passenger operations
C1N, P4N
1236
East Mereenie, NT
Alice Springs, NT/East Mereenie, NT
8441016
The pilot reported that brake pedal pressure was available on both brakes before landing. During the landing roll, no pressure
could be produced in either brake but, after the aircraft had overrun the strip, pressure could be developed in the right hand pedal.
The nosewheel area was damaged when the aircraft struck a ditch.
31 May
1945
Piper 24-400 VH-BOO
Adelaide, SA
Non-commercial - pleasure
Essendon , Vic./Strathalbyn, SA
C1M, P3M
8441017
Due to weather conditions at the planned destination, the aircraft was diverted to Adelaide. About 135 kilometres from Adelaide
the engine began to run roughly but c ruising al titude could be main tained. The aircraft was posi tioned over Adelaide ai rport at
2500 fe~t an~ a right circuit comm_enced_. During the approach, the aircraft began to undershoot and when the pilot appli ed power
the engine did not respond. The n ght win g was torn off by impact with a power pole and the aircraft struck the ground inverted
near the airport boundary.
Charter- passenger operations
C1N, P5N
13 May
Beech 36 VH-TYZ
Kooralbyn, Old/Brisbane, Old.
8411023
Beaudesert, Old. SSW
1509
Soon after settling in t he cruise at 2000 feet, the pi lot noticed that the fuel flow was lower than expected. He selected rich mixt ure
but the fuel f low began to fluct uate markedly and the MAP reduced. A short time later the engine began to run ro ughly, accompanied by a rise in oil pressure and a fu rther reduction in MAP. The pilot elected to return to the departure point. Engine power
became inadequate for level flight and the pilot selected an emergency landing area. The aircraf t came to rest after running
through two barbed wire fences.
ii I Aviation Safety Digest 122
Evans VP1 NOT REG
St Arnaud , Vic.
23 May
1340
12 May
Cessna 402 VH-CJA
Aerial mapping/photography/survey
C2N
8411022
Brisbane, Qld./Archerfield, Old.
1247
Archerfield, Qld.
After landing, a 180 degree turn to the right to backtrack along the runway was planned. As the aircraft was being slowed to tax i
speed, a gentle left turn to position the aircraft near the left side of the runway was commenced, but the right main gear
collapsed. A gear down indication remained on after the aircraft came to a halt.
Charter- passenger operations
C1N, P4N
16 May
Partenavia P68B VH-FAO
Murray Island, Old./Horn Island, Old .
84 11 024
1500
Horn Island, Old .
Severe turbu lence had bee n encountered on final approach but smooth air was entered on short finals. Aft er flaring to land, the
aircraft rolled left rapidly and the landing was made on the left main wheel, fo llowed by the nose and i:lght wheels. The pi lot
subsequen tly inspected the aircraft but did not detect any damage. After two further flights, the pi lot noticed that the left wing
. appeared to be low. Distortion of the left main gear sup port frame was found.
19 May
1630
During the flight the pilot encountered gradually deter iorating weather condi tions, forcing him to reduce his cr uising altit ude
from 5500 feet initially to below 3500 feet. Cloud covered the tops of the adjacent ranges and there were showers and associated
low cloud in the accident area. The aircraft struck the ground at 2140 feet amsl while flying level, banked 20 degrees right under
control and on a heading 55 degrees to the right of the flight plan ned track.
C1 N, P1N
Hi ller UH1 2·E VH-FFX
Commerical-aerial mustering
11 May
P. Plains HS, Qld./P. Plains HS, Qld . 9NW
8411021
1200
Pretty Plai ns HS, Qld.
Wh ile ret urning to refuel at a musteri ng yard, the pi lot attempted to move a bull from some trees. When this proved un successf ul,
the pilot climbed to contin ue the flight to the yard. The engine began to run roughly and an approach to a clearing was made.
Rotor rpm decayed as some trees were c leared and the pi lot was unable to prevent a heavy landing. The helicopter bounced about
two metres, the righ t skid collapsed and the main rotor struck t he ground.
Non-commercial-pleasure
C1N
16 May
Cessna 172M VH-DYM
Oodnadatta, SA/Bond Springs, NT
8441015
Corkwood Bore, NT
0919
As no one had arr ived to meet the airc raft at the planned destination, the pilot flew to a strip on another property. The strip appeared su i tab le to the pilot but during the landing rol l the right wing st ruck mulga trees on the side of the strip. The width of the
strip was subsequently determ ined to be 16 metres and the trees on the side of the strip were up to 5 metres in height.
Injuries
Record number
22 May
0852
10 May
Aerial agriculture
C1M
Cessna T188C VH -HAM
Walgett, NSW 25S/Walgett, NSW 25S
8421021
1400
Walgelt , NSW 25S
The pilot was landing at the conclusion of the second spraying operation for the day. She aimed to touch down about half-way
along the 700 metre strip to allow a following aircraft to land behind her. During the latter stages of the landing roll the tail rose
and the aircraft overturned.
Non-commercial-pleas ure
C1 F, P2F, 01 F, 01 M
15 May
Cessna 340A VH-BYB
Sydney, NSW/Goulburn, NSW
8421022
2345
Goulburn, NSW
On arrival in the circuit area, the p ilot reported his intention was to conduct an Nos approach. The aircraft was subsequently
observed as ii circled th"e adjacent township several times at a low height above the ground. It was then seen to roll and descend
steeply before striking two houses. A fierce fire broke out which engulfed the aircraft and gutted both houses. Initial invest igation revealed a pre-impact failure of the left engine camshaft.
Kind of flying
Departure point/Destination
Non-commercial-pleasure
C1N
Unknown/Unknown
8411027
Du ring a rout ine 100 hourly servicing, both wi ngs were found to be be nt upwards s lightly. On further inspect ion, bot h rear spars
were found buck led just inboard of the inboard aileron hin ges. No ne of the pilots w ho had flown the aircraft sin ce t he last
periodic inspection could recall any unusual stresses being placed on t he aircraft. by tu rbulence or manoeuvring.
C1N
8451011
The fuel gauge was unserviceable and a dip stick was not available. The pilot estimated that there was two hours fuel remaining
by inspection of the contents of the left hand tank only. Seventy minutes after takeoff the engine stopped and an autorotational
landing attempted. The terrain was very rough and during the land.ing the tail rotor struck the ground and the main rotor blades
cut off the tail boom.
Aircraft type & registration
Location
The pilot had been briefed to fami liarise himself with the cockpit prior to pract ising ground handling. He was advised that the fuel
cock was turned off. ~ubsequently , the engine was started and a takeoff carried out. When the aircraft was about 25 feet agl, the
owners heard the engine cut. The aircraft nose dropped and a heavy landing ensued. When the owners arrived at the wreckage,
they found that the fuel cock was in the off position .
05 May
Non-commercial-pleasure
C1 N, P4N
Piper 28-180 VH-DWV
1230
Coonabarabran , NSW
Lismore, NSW/Coonabarabran, NSW
8421028
The weather cond itions were deteri oratin g as the pilot approached to land. On fi nal approach the ai rcraft was too hig h and a goaround was co nducted . During the subsequent circuit, the plot inadvertent ly entered cloud and shortly afterwards control of t he
ai rcraft was lost. The pi lot ultimately recovered control; however, both wings were later found to be bent upwards as a resu lt of
applied aerodynamic loads.
09 May
1645
Date
Time
31 May
2152
Cess na U206G VH-AZC
Goulburn, NSW
07 June
1320
Pilatus B4 VH-U IP
Cent ral Mangrove, NSW
Inst rue! ional-dual
C2 N, P2N
Bankstown, NSW/Goul burn, NSW
8421025
The pi lot under instruction was t raining for the issue of a Night VMC rat ing. At about 250 feet ag l on approach, cons iderable si nk
was experienced and t he aircraft descended be low the desired approach path. Power was applied and the nose was raised but the
sink continued. The instructor took con trol and initiated a go-around; however, the left main gear wheel col lided wit h a fence and
was dislodged. Control was maintained and a safe landing was subseq uent ly carried o ut on return to Bankstown.
•
Non-commercial-pleasure
C1S
Cent. Mangrove, NSW/Cent. Mangrove, NSW 8421027
The pi lot was carrying out his th ird flight for the day when heavy sink was encountered near a small bushfire and an o utlanding
became necessary. During the approach, the pi lot flew below a set of power lines and then attempted to climb over t rees at the
edge o~ the selected paddock. Aft_er passing over the trees, the aircraft was seen to descend steeply and strike the ground,
crumpling the fuselage and damaging the w ing attachment structure.
10 Jun
1200
Burkhart Astir CS
Kimba, SA 30S
VH-WUK
Non-commercial-pleasure
Darke Peak, SA/Darke Peak, SA
C1 N
8441019
Whi le ridge soaring at a low heig_ht an_d 50 knots , the pilot noticed a dead tree a short distance ahead. The glider m ushed during
the ~!tempted pull-up, the left wing hit another tree and the glider t urned through 90 degrees before colliding wi th the upward
slop ing ground.
10 Jun
1540
Fuji 200-180 VH-FJI
Strathalbyn, SA
Non-commercial -p leasu re
Strathalbyn, SA/Strathalbyn, SA
C1 F, P1 F
8441018
0
After performing aerobat ics near the strip, the pi lot joined the circui t for a landing to the south-east. He overflow the field at a low
heig~t , apparently with crui se power set. As the aircraft passed the north-western end of the strip, it was seen to roll left until it
was inverted and nose low. A "pull -through" manoeuvre was then initiated but the aircraft col lided with the ground at hig h speed
and at about 30 degrees nose down .
Aviation Safety Digest 122 I iii
�PRELIM INARY REPORTS (The fo llowing accidents are st i ll under investigation)
FI NAL REPORTS (The invest igat ion of the fol lowing accidents has been completed)
Date
Time
Date
Time
Pilot licence
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
14 Jun
Hiller UH12E VH-FBQ
Instructional-dual
C2N
'Bamboo' Outstation/' Bamboo' Outstation
1430
Aurukun , Old. 56SE
8411029
Cattle were being mustered from open country with the helicopter operating at 15 to 20 feet agl in wind gust ing to 25 knots. At the
completion of one downwind run the trainee flared instead of turning into wind. The main rotor blades overpitched and the
helicopter stn:ick the ground heavily, tail down, before the instructor could recover control of the situation.
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Record
number
14 Apr
Piper 28-1 80 VH-PPB
1045
Warialda, NSW
Private restricted
Non-commercial-practice
C1N
Warialda, NSW/Warialda, NSW
8421017
29
40
40
None
During a landing in light crosswind conditions, t he aircraft began to veer lef t. Right rudder was applied but the swing conti nued
until the aircraft was travelling sideways. The nose wheel broke off when it contacted an area of so ft ground.
Commercial - aerial mustering
15 Jun
Hughes 269-C VH-KZR
C1N
Mt Anderson, WA/Mt Anderson, WA
Mt Anderson, WA
8451013
0805
After a normal land ing the hel icopter began to bou nce sideways. The pi lot suspected the onset of ground resonance and
attempted to li ft off. The helicopter slewed left and a mai n rotor blade st ruck a large drum.
The approach and touchdown were made at a speed in excess of that recommended for the ai rcraft type. The pilot was relatively
inexperienced and had probably not applied suffic ient back pressure to the elevator contro ls in order to reduce the effective
weight on the nose wheel. A 'whee l-barrowing ' situation had developed, leading to a loss of directional control.
18 Apr
1530
Commercial
Charter-passenger operations
C1 N, P1 N
Lila Springs Stn., NSW/Beemery Sin., NSW
8421 018
21
1050
190
Instrument rating 1st class
or class 1
The pilot was making his first landing at the strip. He had been advised to bring the aircraft to a halt before passing the windsock
because of a soft surface beyond t his po in t. Initial touchdown was about 400 metres past the threshold but all wheels were not
firmly on the ground until the aircraft was 39 metres beyond the windsock. The wheels progressively sank in to the surface and
after a ground ro ll o f 160 metres the nose gear fork sheared off and th e aircraft pitched onto i ts nose.
22 Jun
Cessna A188B-A1 VH-MXH Aerial agriculture
C1N
Glen Var Station, WA/Glen Var Stat ion, WA
1400
Wongan Hills, WA 16E
8451015
Prior to commenc ing spraying operations for the day, the pilot had taken samples from three of the five fuel drain points fitted to
the aircraft. Water was detected at each point and further samples were taken until no trace of water remained. Further samples
of clean fuel were obtained after two subsequent refuellings. On takeoff after t he second refuelling the aircraft failed to
accelerate normally and col lided with a fence after overrunning the strip. Water was later found in the fuel system.
24 Jun
Cessna 210M VH-PKR
Non-commercial -pleasure
C1S, P2M, P3N
8431017
Birchip, Vic./Birchip, Vic. 24NW
1515
Birchip, Vic. 24N W
The aircraft touched down about 150 metres past the threshold of the 600 met re strip and bounced. The pilot app lied power to goaround and gradually raised the flap, but the aircraft then began to sink and he was unable to prevent the left wing striking the
ground. The aircraft cartwheeled and rapidly came to a halt.
Beech 95-855 VH-FEM
Brewarrina, NSW 40W
The approach had been f lown at a speed about 10 knots in excess of that recommended for the prevailing condit ions and had
been made with a tai lwind component of about 5 knots. Although the aircraft had floated for a cons iderable dis tance beyond the
target touchdown point, a go-around had not been initiated.
21 Apr
1302
Commerc ial
24 Jun
Mooney M20F VH-ERY
Non-commercial-business
C1 N, P1 N
1600
Mundabullangana, WA
Belele Homestd., WA/Mundabullangana, WA 8451016
A go-around was made from the first approach as the aircraft was overshooting the pilot's aiming point. On the second approach
the airc raft began to porpoise alter touchdown. Braki ng was commenced with 200 metres of the 750 metre strip remaining. After a
further 100 metres the pilot attempted to go-around. The aircraft came to rest some distance beyond the strip end alter colliding
with a number of mounds of earth.
Partenavia P68B VH-PNZ
Bankstown, NSW
24
Charter-passenger operations
C1S, P5N
Bankstown, NSW/Bendigo, Vic.
8421024
1400
50
Instrument rat ing 1st class
or class 1 with instrument
rating
Aft er passenger loading had been comp leted , but before the eng ines were started , the pi lot remembered that a nose whee l chock
was sti ll in place. She disembarked and removed t he chock; however, the aircraft com men ced to rol l down the slightly sloping
tarmac area. The chock was rep laced but the aircraft rol led over the chock and the left main wheel passed over the pilot's ri ght
leg. The aircraft came to a halt at the bottom of the slope.
The pi lot was subsequently unable to recall whether the parking brake had been fully applied or whether she had inadvertently
released the brake when push ing her seat back with her feet on the rudder/brake pedals prior to disembarking to remove the
chock.
Non-commercial-pleasure
C1N, P1N
Cessna 210L VH-KWW
28 Jun
1410
Kalgoorlie, WA
Orleans Farms, WA/Esperance, WA
8451017
When the pilot selected the gear up alter takeoff, the retraction cycle took longer than normal. The gear was selected down prior
to the next landing and although the gear up light extinguished, the gear motor did not operate and the gear down light did not
illuminate. Attempts to lower the gear, using the manual system, were unsuccessful and the aircraft was diverted to a more
suitable airfield. During the subsequent landing roll the main gear, which was partially extended , collapsed.
24 A pr
1725
Private
Instruct ional - dual
Leongatha, Vic./Leongatha, Vic.
C2N
29 Jun
Piper 25-235/A 1 VH -MYE
0930
Leongatha, Vic. 8SE
8431018
A spray run was being flown along the boundary of a paddock. One tree infringed t he run and the trainee elected to apply rudder
to direct the aircraft past the tree. Incorrect rudder was applied and the instructor took over but the left wing struck the tree. The
instructor was able to maintain control, although one metre of wing and the ai leron had been torn off. He landed the aircraft in the
adjoining paddock without further damage.
Mooney M20F VH-ERD
Mildura, Vic . 67NW
58
Non-commercial- pleasure
Cobar, NSW/Renmark, SA
1367
450
C1 N, P3N
8441013
None
The pilot intended refuel ling at the previous landing po in t but he found that fuel was not avail able. After re-c hecking his fuel
req uirements, he was satisf ied that the fl ight cou ld be accomplished with almost full reserves. The weat her deteriorated and
groundspeed reduced during the fl ight, causing the pilot to become concerned abou t flight visibilit y and fuel endurance. He
elected to make a precautionary land ing near a homestead but during the land ing ro ll the aircraf t ran through a fence and col lided
with a ditch.
Although the pilot had lost time on earlier legs of the flight , he made no similar al lowance for the subject leg, nor did he divert to a
suitab le refuelling point. Having decided to carry out a precautionary landing, the pilo t did not make a low-level inspection of the
area. The approach to land was made downwind and the aircraft did not touch down unt il it was less than 220 metres from t he end
of the 2000 metre paddock selected.
28 Apr
1340
Commercial
FINAL REPORTS (The investi gation of the fo llowing accidents has been completed)
Date
Time
Pilot licence
Aircraft type & registrat ion
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Record
number
05 Apr
Beech A36 VH-WHH
Non-commerc ial - pleasure
C1N, P3N
1000
Cobham HS, NSW
Tibooburra, NSW/Cobham Homestead, NSW 8421016
Private
37
297
78
Instrument rating class 4
The pilot was aware that a rough area existed adjacent to the threshold of the strip. He elected to land long and clear of the ro ugh
section, as sufficient strip length remained fo r a safe landing. He stated that he was concentrating on ach ieving a precise point of
touchdown and did not realise until after landing that he had omitted to extend the landing gear.
The landing gear warning horn was subsequently found to be unserviceable.
05 Apr
Bell 47-G2 VH -RFE
Non-commercial-practice
C1N
1400
Amata, SA
Amata, SA/Amata, SA
8441012
Commercial - helicopter
37
8743
7395
None
After completing an autorotation with power termination, the pilot decided to carry out a full autorotative landing. During the approach all collective control was used prior to touchdown. The helicopter landed heavily and the main rotor blades severed the
tail boom.
The pil ot m isjudged the heig ht of the helicopter above the ground when commencing the flare prior to landing.
iv I Aviation Sa fety Diges t 122
11
1
Piper 18-150 VH-FPI
Manjimup, WA
20
Act ivit ies associated with fire con trol
C1 N
Manjimup, WA/Manj imup, WA
8451010
601
394
Instrument rating class 4
Because of strong crosswind cond itions at his planned destination, the pilot diverted to a nearby strip which was aligned into the
prevailing wind. Although the groundspeed was low during the approach, the pilot elected to use full flap for lan ding. Shortly after
touchdown the left wing lifted and the p ilot was unable to apply fu ll correct ive ai leron because his knee became jammed between
the control column and the f lap lever. The aircraft ran off the side of the strip and struck a fence.
The fence was on ly 28 metres from the centre-line of the s trip. In his efforts to app ly ful l aileron, t he pi lot had lifted his le ft foot
from the appropriate rudder pedal, wh ich pro bab ly increased the ten dency of th e aircraft to diverge to the right of the strip.
13 May
1326
C0mmercial
Cessna 337G
Gove, NT
VH-KUX
Charter- passenger operations
C1N, P1N
Elcho Island, NT/Gove, NT
844101 4
24
899
440
Instrumen t rating 1st class
or class 1 with instrument
rating
Prior to commenc ing a 60 minute flight the pilot estimated that the aircraft held fue l for 120 minutes. The front engine fai led when
the aircraft was 25 km from the destination. The rear eng ine subsequently fai led and a gl ide approach from 9 km and 3000 feet
commenced. A 15 knot headwind was present and the aircraft landed 7 me.I res short of the aerodrome boundary fence. The right
main gear was torn off in a ditch during the 135 metre ground rol l.
When the aircraft was last refuelled , ii was not filled to capacity and the pilot probably inaccurately estimated the amount of f uel
on board. Fuel usage rates did not vary signi ficantly from those used by the pilot for f light planning. The f uel gauges were found
to overread in the lower quantity range.
Aviation Safety Digest 122 I v
�FINAL REPORTS (The investigat ion of the following accidents has been comp leted)
Date
Time
Pilot licence
26 May
1515
Private
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Record
number
C1N, P3N
8421023
19
Non-commercial -pleasure
Bankstown, NSWI Bankstown, NSW
46
6
None
Piper 28-140 VH-MTU
Hoxton Park , NSW
The aircraft bounced after the initial touchdown and subsequently porpoised a number of times before the pilo t was able to
regain control of the landing. He later inspected the aircraft but did not notice any damage which might have occurred during the
landing. On the subsequent takeoff, pitch attitude control difficulties were encoun tered and the pilot carried out a low level ci rcuit and landing. Damage to the rear bulkhead and stabilator trim support brace was discovered.
The damage had been sustained during the initial touchdown, which had been on t he main wheels and t he tai l skid, and had
probably accounted for the pilot's difficulty in controlling the subsequent porpoises along the runway.
13 Jun
1000
Private
Maule M5-235C
Nanango, Old.
VH-MSM
44
Non-commercial-business
Tara, Old.INanango, Old.
515
265
C1N
841 1028
None
The pilot assessed the crosswi nd to be in excess of the aircraft limits on the two prepared strips and elected to land on a disused
strip aligned into-wind. During the approach, he noticed a horse being exercised adjacent to the land ing area and steepened his
glide path in order to land closer to the strip threshold and thereby avoid frighten ing t he horse. On touchdown the right main
wheel struck an anthill, the gear col lapsed and the aircraft groundlooped.
The anthill was hidden by the long grass on the strip , which had not been maintained for some time. The pilot had used the strip
on previous occasions but had not attempted to land close to the threshold.
17 Jun
1340
Private
Avnspier Robi n-R2160
Wedderburn, NSW
VH-XXY
Non-commercial - practice
C1 N, P1N
Wedderburn, NSWIWedderburn , NSW
8421029
36
379
33
Ins trument ra,ting class 4
The pilots were pract ising precision flying circuits and landings in preparation for a fort hcoming competition . Weather conditions were fine but with variable and gusty winds. As the pilot flared the aircraft fol lowing a normal approach , substantial windshear was encountered and the aircraft landed heavily. A subsequent inspection revealed st ructu ral damage had occurred in the
fuselage adjacent to the rudder pedal area.
Both pilots had operated from the strip on previous occasions and were aware that windshear cond i t ions were frequently en countered under the prevailing wind conditio ns. On th is occasion , the pilot reported that the onset of shear was so sudden that
there was no time to take corrective action before the aircraft struck the ground.
18 Jun
0705
Commercial -
Hughes 269C VH-SMT
Moola Bul la Sin ., WA
helicopter
34
C1S
M. Bulla Stn ., WAIM. Bu ll a Si n., WA 37 WSW 8451014
882
785
None
The pilot had planned to carry out a cattle muster in conjunction with another aircraft. He had been late in departing his base, but
when he found the other aircraf t had not yet arrived at the rendezvous point, he decided to make a quick comfort stop. The
helicopter was landed on a spinifex covered area and the pilot disembarked, leaving t he engine running. Shortly afterwards he
noticed a fire underneath the helicopter and reboarded in an attempt to fly it away f ro m the fire. The engine did not respond. The
pilot disembarked and attempted unsuccessfully to extinguish the fire. He received burns to his hands and legs while unloading
equipment and the helicopter was destroyed.
FINAL UPDATES (The investigation of the following accidents has been completed. The i nformati on is
additional to that previously printed in the pre lim inary report)
Date
Pilot licence
Date
Pilot licence
19 Mar 83
Private
Record number
Age
8321030
49
Aircraft type
Hours total
Piper 23-160
540
Hours on type
Rating
350
Rutan Vari Eze
500
100
None
Just before touchdown the aircraft encountered wake turbu lence from a preced ing landing aircraft. The pilot ap plied full power
and attempted a go-around , but the aircraft contacted the runway heavi ly and the nose gear collapsed.
17 May 83
Com mercial helicopter
8321041
24
Hiller UH12-E
1900
Rating
Cessna A 188B-A 1
8321071
Agricu ltural class 1
7400
600
39
The aircraft was descending over a line of trees prior to commenc ing a spray run when the left wing co llided with the branch o f a
tree . The pilot was able to maintain control of the aircraft and land at a nearby strip.
25 Sep 83
Private
831 1061
31
Piper 32-260
700
300
Instrument ratin g c lass 4
The pilot was conducting a short field approach into a 525 metre strip. He reported that thermal ac tivity was encountered and the
ai rcraft touched down a short distance beyond the target point. As soon as full brakes were applied, the aircraft commenced to
veer to the left and despite appropriat e corrective action the pilot was unable to prevent the aircraft running off the s ide of the
strip.
A defect in t he master cy linder caused the lef t brake to lock and the left main gear struck a tyre used as a stri p marker. Col lision
wi th the tyre fract ured the torque link al lowing t he left main gear to separate from the o leo leg. The st rip w idth between the tyre
markers was only 25 metres, wh ich was below ALA s tandards.
02 Oct 83
Private
8351024
32
Cess na 172M
None
10
90
Whi le conduct ing a series of prac tice circu its, t he pi lot noted that a crosswind from the right was evident down to 50 feet on the
approach, but the wind at ground level was blowing down the st rip in use. On the last circu it a normal approach was made;
howeve r, shortly aft er touchdown the airc raft began to drift despite the application of correct ive rudder. A go-around was made
but the dri ft to the right continued . Flap was raised but contro l was t hen lost and the aircraft s truck trees .
No fault was found with the ai rcraft that could have contributed to the acciden t. There was no method by wh ich the pi lot could
conti nuously mon itor the w ind ve loc ity at t he strip. It is probable that the airc raft was affected by a crosswind th at caused it to
drift to the ri ght after touchdown. During the attempted go-around , adequate airspeed was not maintained and the aircraft stal led.
04 Oct 83
8321077
Victa 115
Student
47
58
32
None
The student pilot was briefed to conduct a period of solo consol idation t raining. After several circu its and land ings had been
comp leted, the pi lot flew the aircraft to a st rip at a nearby mili tary installat ion. A passenger boarded the aircraft and the pi lot then
conducted a takeoff with the intention of making a local f light. A partial loss of eng ine power occurred and the aircraft subsequently stru ck the ground with a high rate of descent and came to rest inverted .
The cause of the eng ine failure could not be posit ively determined .
24 Oct 83
None
8351026
36
Cessna 182P
10
None
After unsuccessful attempts were made by two pri son escapees to stea l three other aircraft, the engine of t he subject aircraft
was started . Shortly after commenc ing to taxi the aircraft coll ided with a parked Beech Bonanza; however, taxiing to the runway
was continued. Sh ortl y after becom ing airborne the aircraft turned to the left and coll ided with the ground.
The man acting as pi lot had held a student pilo t licence some nine years prev ious ly. He had obtained about 10 hours dual training
and had since been permitted to fly various aircraft wh ile a passenger but had not received any ins trument flight tra ining.
Al though the moon had ri sen, the night was dark and smoke haze obliterated the horizon.
8321085
29
Piper 25-235
1250
20
None
Sho rtly after becom ing airborne, the pilot observed that the temporary fabric covering on the left win g was bal looning and
adv ised t he tower that he was returning. The aircraft turned left unti l lined up with st rip 18 and the pi lot adv ised t hat he wou ld
recheck the condition of the left wing and may land downw ind. He s tat ed that the nose and left wing dropped suddenly and t hat
despi te corrective fligh t contro l action, he was unable to prevent the aircraft striking the ground.
None
The ai rcraft evidently encountered the wake turbulence c reated by the hel icopter.
8321031
36
Hours on type
The pilot had not flown the aircraft type for about 3 years . During the approach to land , the aircraft had stalled and the pi lot had
employed an in correct recovery tec hnique.
The aircraft was crossing the threshold, about 300 metres behind an Iroquois hel icopter, when the rig ht w ing d ropped. The nose
also dropped and the nose wheel contacted the runway heavily and was broken off. The aircraft slid along the runway for some
200 metres on its nose·before com ing to rest.
19 Mar 83
Private
Aircraft type
Hours total
10 Sep 83
Com mercial
03 Nov 83
Commerc ial
FINAL UPDATES (The investigation of t he follow ing acc idents has been completed. The information is
add iti onal to that previously printed in the preliminary repo rt)
Record number
Age
18 Nov 83
Student
In strumen t rat ing class 4
Piper 24-400
33
Not known
None
At abou t 0200 hours, the owner and a passenger boarded the aircraft for a local fl ight. A resident heard it take off and saw the aircraft lights in the ci rcu it area. He also noted that the runway lights were i l lum inated. A go-around was made on the first approach
and the aircraft was landed after anot her c ircu i t. A takeoff was carried out in the oppos ite direct ion and shortly after becom ing
airborne the aircraft st ruck the ground. Fire broke out and engulfed the wreckage.
It was not poss ible to det ermine who of the occupants was mani pulat ing the controls at the t ime of the acc iden t. Neither person
was qualifi ed to operate the aircraft. Post mortem examinations revealed that bot h persons had high blood alcoho l levels.
05 Feb 84
Private
1600
8331035
32
8431004
36
Piper 32-300
214
23
None
Whil e on crui se at 1000 feet agl, the aircraft experienced a sudden loss of height. The pi lot carried out an autorotative landing on
river mud flats. During the landing the tail rotor struck th e water.
Aft er takeoff, t he pilot noticed that the eng ine cow l had lifted slightly. He dec ided to comp lete the circu it and land. During the
crosswind leg of the ci rc uit , the cow l lifted comp letely from the left attachment points and obscu red, to a large extent, the pi lot's
forward vision. An approach was then made to a cross strip and on short final the pi lo t lost sight of the runway and the aircraft
landed heavil y.
The transmi ssion o f the heli cop ter failed after the disintegration of the pl anetary gears which was caused by fatigue cracking .
Fatigue cracks were found in several sections of the remaining gear fragmen ts and it was not possible to determ ine the exact
origin of the final failure.
The top engine cow l had not been correctly sec ured before fl ight. Inspection o f the aircraft revealed that the lug holes that accept
the cowl loca1 ing pins were not fitted with the requ ired nylon inserts. It was possib le for the cowl side latches to appear to be
fastened when in fact they were not properly engaged.
vi I Aviation Safety Digest 122
A viation Safety Digest 122 I vii
�FINAL UPDATES (The investigation of the fol lowing accidents has been comp leted. The information is
additional to that previously printed in the prel iminary report)
Date
Pilot licence
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
03 Mar 84
Senior commercial
8441006
30
Britnor BN2-A21
4995
24
Inst rument rating 1st c lass or c lass 1
Helicopter Vne: what's it all about?
Helicopter Vne speeds are not always well understood by rotary-wing pilots.
The east-west strip at the destination had been rendered unserviceable by recent rain. The pi lot was advised that another strip
which ran parallel to this strip was serviceable, as was a third north-south strip a sho rt distance away. When the aircraft arrived in
the circuit area, the wind was southerly at 30 knots and the pilot decided to land on the north-south st rip. However, s ince the inspection 38 millimetres of rain had fallen and water about 20 centimetres deep lay across a sect ion of the strip when the aircraft
landed. As the main wheels entered the water, the nose wheel was pulled into hard contact with t he str ip and col lapsed rearward.
12 Mar 84
Commercial
8441008
22
Cessna U206-G
282
19
Instrument rating class 4
During the landing flare the aircraft ballooned and assumed a nose-high attitude. The pilot attempted to take correct ive action but
the tai l contacted the ground before the main wheels . The aircraft bounced and on the subsequent touchdown the tail again
struck the ground.
The pilot was inexperienced on the aircraft type and had used an approach speed below that recommended in the Aircraft Flight
Manual. The aircraft was flared too high and incorrect recovery action was taken by t he pilot after t he aircraft bal looned.
15 Mar 84
Commercial
8451006
26
Cessna 182-DIA1
615
32
Instrument rating class 4
The model specification for this aircraft indicates that it has been converted to tail-wheel conf iguration. The pi lot reported that
the windsock was indicating a wind of 270 degrees 10 to 13 knots. He elected to land on runway 13 and after a three-point
touchdown the aircraft began to turn right. The pilot was unable to regain directional contro l and the aircraft ground looped, bend i ng the left wing and tailplane.
18 Mar 84
Private
8441009
34
Cessna 182K
187
72
None
While airborne for parachute dropping operations , the pilot noted that the weathe r at his desti nation had deteriorated. He elec ted
to divert to a clear area and carry out a precautionary landing. The area selected was soft and during the landing roll t he nose gear
strut collapsed .
The pilot was in receipt of weather forecasts that indicated the probability of rainstroms and low cloud in his area of operation.
Insufficient fuel was carried in the aircraft to allow the pilot to hold until the weather c leared or divert to a more su i tab le land ing
area.
19 Mar 84
Student
8441010
38
Piper 28-140
38
37
None
After a number of dual circuits, the pilot was authorised to carry out solo circuits with touch and go landings. After the first
touchdown the pilot applied full power, then selected the flap to 10 degrees. The ai rcraft entered a rapid turn to the left and the
pi lot abandoned the takeoff. The aircraft slid sideways off the strip and the nose wheel was broken off.
The pilot was carrying out her first solo period of touch and go landings. After applyin g fu l l power she noticed that the aircraft
was accelerating more quickly than when she had been under dual instruction. The pilot had previously requ ired forward pressure
on the control column while retrimming the aircraft. On this occasion , she had not had time to retrim and the invest igation
revealed that the aircraft had been 'wheelbarrowing' on the nose wheel when d irect io nal control was lost.
20 Mar 84
Commercial
8421012
Beech E55
409
Flight instructor grade 3
1230
40
During the course of the flight , the pilot learned that the passenger in the right hand front seat held an American pilot li cence and
was experienced on the type. He allowed the passenger to manipulate the controls until the ai rcraft was on final approach and
allowed him to keep his hands l ightly on the controls during the flare and touchdown. During t he landing rol l t he passenger,
unnoticed by the pilot , inadvertently selected the landing gear up. The aircraft s lid to a halt with the gear partiall y retracted.
24 Mar 84
Private
8451007
29
Cessna 172N
142
36
None
The pilot was landing into the east with a 10 to 12 knot southerly wind. On short final app roach at a speed of 60 knots the aircraft
encountered sink. Touchdown was heavy and resulted in damage to the propeller, nose gear and engine firewall.
To the south and parallel to the runway are a line of sandhi ll s approximately 100 feet high. Wit h the prevailing wi nd, it is probable
that mechanical turbulence would have been present during the later stages of the approach. The pilot lacked bot h recent and
general flying experience.
Bell 47-G4
24 Mar 84
8421014
None
90
960
Commercial helicopter
The pilot was inspecting areas of noxious weeds to check on the results of recent sprayi ng. The helicopter st ruck a power line
which severed the bubble windscreen. The wire then contacted the pilot 's throat before being cut by t he main rotor. The
helicopter st ruck the ground tail rotor first from the wreckage , the pilot swam ac ross a river, wal ked 3 km to a homestead, and
drove 15 km for help. He was later admitted to intensive care in hospital.
The pilot had been unaware of the location of the power lines until immediately before t he co llision. An aerial survey of t he area
had been planned but had not been undertaken. There was evidence to indicate that the pi lot had flown beneath the wires on at
least one occasion while spray ing. The pol es supporting the span struck by the helicopter were 253 met res apart and were
probably out side the pilot's normal field of vision at the time of the strike.
2?
27Mar84
Commercial
8411016
19
Piper23-250
290
93
In st rument rat ing c lass 4
Prio r fo the departure for the planned 50 m inu te flight the pi lot had added fuel to give an endurance of 100 minut es. Adverse
weather was encountered en route and the pilot became uncertain of his positi on. In fadin g daylight he recognised the
Burketown area and requested Flight Service to organise strip lighting. Before this could be arranged, the left eng ine fai led and
the pilot attempted to land on an old road . Touchdown occurred in a ro ugh area adjacent to the road and the landing gear
· col lapsed. The left engine had fai led from fuel exhaustion. When refu elling the aircraft the pil ot had not added suffi cient fuel to
allow for 60 minutes holding at the destination, as required , becau se of the forecas t adverse weather.
viii I Aviation Safety Digest 122
In a recen t d iscussion on the subject, a pilot who once
flew Hueys in V ietn am rem arked:
•
W e were in this valley in the C en tral Highlands and
s tarted taking a utom atic weapons fire from both
r idgelincs. I pulled in collective and pushed the nose over
- must have gone a bout 15 knots past the red line
getting out of there. T he machin e shook a little more
than normal b ut continued to fly okay.
The pilot implied that nothing seriou s will happen if
from time to time Vne is exceed ed b y some reasonable
amount because, ba sed on his experiences, the H uey
did n 't exhibit a ny un usua l characteristics, such as a
violent pitch up and roll which one would expect from
blade stall , n or d id it sha ke so violen tly that r ivets were
loosened and the instruments became unreadable. His
feeling was tha t there must be some margin built in to
V n e li m its to prevent sudden catastrophic failure and to
protect p ilots from their own excesses in handling
aircraft.
W ell, to be sure, there are margins, but as a test
pilot and aerodynamicist for a major helicop ter
manufact urer said recently: ' L ots of considera tions go
in to derivi ng a hel icopter' s Vne envelope. I t could be
blade stall margins, controllability, or vibratio n and
stress levels wh ich limit the service life of critical
components' . In short, if V ne is exceeded, it could be
bad news righ t then and there or sometime later.
T ake, for example, the matter of con trollability. On
some m odels of the SH -3 hel icopter (the military
version of the S-61), Vne is lim ited by controllability .
As Vne is approached in level flight, the cyclic has to
be positioned increasingly fo rward, to the extent that if
a irspeed was not lim ited, all forward cyclic travel would
be used up and the stick would strike its mecha nical
stop, even tho ugh sufficient blade stall and component
stress margins remained. A t that point, if a gust were
to suddenly pitch the nose up, there would be no
forward cyclic control remaining to retu rn the aircraft
to level flight, and in effect the hel icopter would be out
of control.
Aviation Safety Digest 122 I 13
�What about blade stall? Most modern helicopters are
n ot limited by blade stall, but blade stall certainly is a
limit. O ne day some years ago a Navy pilot flying an
H -2 fo und himself falli ng behind on his fl ight plan d ue
lo unfo recast south-westerly winds. The pilot must have
fo rgotten his basic hcli copler aerodynam ics, or perhaps
never really learned the subject, because his response lo
the low groundspeed was to ' beep' the cyclic forward
with the altitude hold engaged lo increase indicated
airspeed. H e said : 'The next thing I f<new the
vibrations increased and we pitched up and rolled left'
Whether o r n ot the H -2 was limited by blade stall on
that flight I don 't k now , bu t the pilot learned an
aerodynam ic fact of life that day .
Stress levels of critical. rotor head and rotor blade
components are the mai n reason for limiting Vne in
m odern helicopters. In the U H -l H , for example, the
loads o n rotor head components rise dramatically as
Vnc is ap proached. Figure 1 shows how a small
increase in indicated airspeed (near Vne) results in a
very sleep rise in pitch link, scissors lever and collective
boost tube loads. Even exceeding the Vne by a small
amoun t in such stress-limited aircraft (as you can see by
extrapolating the curves upward) results in sharply
higher loads wh ich will almost certainly reduce nominal
componen t life. A system safety engineer for a major
helicopter manufacturer pu t it this way : 'This damage
m ay not be eviden t un til a crack or other defect
develops considerably below the retiremen t or overhaul
fl ight h our level'. It is important to remember that each
revolution of the cr itical par t, whalever it is , consti tu tes
one overstress cycle. I n the extreme, the engineer said,
the ser vice life o f a comp onent designed for many
hundreds of hours could be reduced to the poin t where
only a few hours of safe operation remain. For this
reason, whenever V ne is exceeded, it should be
regarded very seriously and pilots should take pains to
record the d uration of such events, a long with in dicated
a irspeed, gross weight, rotor RPM , engine power
settings, pressure altitude and even o utside air
temperature. From this data , the main tenance
departm ent will determ ine (sometimes wilh the help of
the m anufacturer) to what degree component life was
reduced and if further checks are required before the
helicop ter can be flown again .
Computing componen t service life is a highly
Figure 1
ROTOR COMPONENT LOADS VS AIRSPEED
650
600
550
500
450
-
V>
a:i
...I
V>
400
350
0
-et 300
0
...I
250
200
150
100
50
.05
.1
.15
.2
0
CAS X VNE
.25
.3
.35
.4
.45
.5
.55
.6
.65
.75
.8
.85
.9
.95
..0. SCISSORS
QCOLLECTIVE
BOOST TUBE
PITCH LINK
.7
1.0
VNE
LEVER
Figure 2
OAT~
30° C
PRESSURE ALTITUDE - 2000 FEET
450
FUEL FLOW - LB/ HR
650
500
550
600
PRESSURE ALTITUDE - 6000 FEET
350
700
120
110
110
100
110
100
0
90
%
""
90
90
.,,
0.
"'~
80
"'
80
0
.,,
""
I-
0
""
%
w
w
0.
.,,
70
60
60
80
80
60
50
0
I-
<
u
%
::i
"'
40
60
25
30
35
40
CALIBRATED TORQUE - PSI
14 I Avia tion Safety Digest 122
45
50
u.
0
0
"'
w
.,,
0
%
0.
.,,
0
w
<
u
50
40
50
40
40
30
30
45 u.
w
.,,
40
20
""
w
w
I-
40
15
%
"'~
0.
.,,
50
50
70
0
0
w
.,,
0
90
"'<
w
Adapted from Flight Crew
I-
I-
60
50
90
60
"'<
I-
%
90
70
0
70
0
100
100
w
w
70
80
w
::i
.,,
I-
I-
w
w
650
11 0
120
0
FUEL F LOW - LB/ HR
450
500
550 600
120
130
.,,
400
complex process and Vne is just one of the end
products of this work. When making a helicopter,
designers look at the machine's mission and then tailor
the strength of components to m eet the specifica tions.
Of course, as we well know, the true tesl of their work
comes when the machine enters service. Chader and
aerial work o perators who routinely fly at high speed
very often operate near Vne limits which will vary
appreciably with changes in gross weight and cruising
altitude.
For example, in high, warm places such as the
A therton Tablelands, the Blue Mountains and the
Southern Tablelands in the summer, a helicopter
cruising at maximum range speed just a thousand feet
above the ground could be just a few knots below Vne
and with some a ircraft Vne might actually be cruisespeed limiting. T his could also be true in the very h igh
temperatu res which occur regularly at sea level
throughout Australia , especially in the summer .
Figure 2, which shows t he speed envelope of a U H-lH
at an outside air temperature of + 30 °C at 2000 feet
and 6000 feet pressure altitude, illustrates this po int.
Note how at 2000 fee t a 7000 pound Huey has a
maximum range indicated airspeed of 112 knots (roofmoun ted p itot) and Vne is 117 kno ts . At 6000 feet,
V ne is limiting, so it becomes the max im um range
indicated airspeed at 101 knots. Also note how Vne
indicates airspeed drops off sharply as gross weight
increases. T he red line painted on the airspeed
indicator (which is valid only at sea level on a standard
day) may be doing more harm than good by luring
some pilots into faster speeds than they should be
operating a t. As a matter of professionalism and flight
safety, pilots flying at high speed should make it their
business to check Vne each time they change altitude.
Perhaps someday Vne limits will be displayed on the
airspeed indicator by a moving 'barberpole' pointer,
much like it is on today' s jet transports.
In summary, helicopter Vne speeds have to be
understood and appreciated for what they are : critical
aircraft limitation, which often is not depicted correctly
on airspeed indicators . Also, on modern high-speed
helicopters, Vne can be exceeded with n o perceptible
increase in vibration level or control feel and , if
exceeded, could ultimately have catastrophic
conseque nces •
10
15
40
20
25
30
35
CA LI BRAT ED TORQUE - PSI
0
0
"'
0
%
0
%
Who is flying the aircraft?
T he pilot of a Cessna 182 fitted with an autopilot
almost came to grief recently by accidentally h itting
the ON/OFF switch during lhe takeoff roll.
He op ened the throttle and unbeknown to him one
of his knuckles cam e into contact with the autopilot
switch , pushing it into the ON position. As it
happened, the 'bug' on the heading indicator
associated with th e autopilot was set in a position
80 degrees to the right of the runway heading. Much
to the pilot's sur prise, the aircraft immediately
started to try to 'fly' the heading indicated, but
before it left the ground he was able to regain
directional control a nd abandon the takeoff.
This particular pilot has developed his own
solution - he has reversed the switch so that it
cannot be inadverten tly pushed to ON a nd he also
now aligns the heading indicator 'bug' on the
runway heading prior to takeoff •
Aviation Safety Digest 122 I 15
�Pressing on regardless
The Flight Information Service provided to pilots
operating outside controlled airspace in Australia is
widely regarded as very effective and well suited to the
flexible nature of GA operations. Relevant preflight,
traffic and operational information is available to all
aircraft on request. A fundamental characteristic of this
system is the operational freedom it affords pilots who,
with in certain guidelines, can choose the amount of
information they receive and the way in which they use
such facilities as airspace, aerodromes and SAR services.
Inherent in the flexibility of this system is the
devolution to pilots of the responsibility , first, to obtain
all the information applicable to their operations, both
before and during a flight ; second , to assess the
information themselves; and finally, to take action in
response to that information. This is a continuum of
processes, which therefore makes it essential that pilots
recognise their responsibility to take full advantage of
inflight information services and to update , if necessary,
planned courses of action. That responsibility was not
accepted in the accident examined below.
Preflight
Before planning a flight from central New South Wales
to Essendon the pilot of a C herokee Six telepho ned a
meteorological office for a flight forecast. H e was
advised that the predicted en route weather generally
was good. A cold front, accompanied b y strong wind
gu sts, sharply decreasing visibility and moderate to
severe turbulence, was expected to pass through the
southern section of the PA 32's route later in the day,
after the Cherokee's ETA Essendon. In view of the
generally favou rable forecast , the pilot was confidently
able to su bmit a VFR flight plan.
lnflight
D eparture was made on time and the flight initially
proceeded sm oothly at an altitude above 5000 feet.
However , as the Cherokee (shown as Aircraft A on the
map) approached about 20 nm north of Bathurst,
AIREPs from other a ircraft on the same FIS frequency
began to indicate that ac tual weather conditions were
different fro m those predicted.
R eports from two other aircraft were passed to
Sydney FIS that the leading edge of the cloud which was
associated with th e front was lying some 12 nm east of
Orange, aligned south-east to north -west. From these
reports it was clear that frontal passage had occurred
earlier than expected.
Aircraft A 's track took it over Bathurst towards
Cootamundra. When it was 12 nm south-west of
Bathurst, anoth er sign ificant AIREP was passed to
Sydney. This was from Aircraft B, which was tracking
from Cowra to Young, and which ad vised that there
were substan t ia l dust storms in the area up to 5000 feet ,
and that he was IMC in dust at 3700 feet (which was the
lowest safe altitude). As can be seen from the m ap,
Aircraft B's track was adjacent to Aircraft A 's intended
track.
Sydney Flight Ser vice contacted Aircraft A as it
16 I Avia tion Safety Digest 122
/
approached Wyangala R eservoir and repeated Aircraft
B 's AIREP. At a bout the same time, other aircraft
reported severe turb ulence in the Cowra/ Young/ Yass/
Goulburn area generally, and in tense dust storms up to
6000 feet around Rugby.
By this stage Aircraft A had descended to 4000 feet
to remain VMC because of a lowering clou d base, a nd
had also begun to experience considerable turbulence.
The pilot later confirmed that he h ad been able to see
the dust storms for some time as he approached the
general Cowra area.
There were, then, clear indications that Aircraft A
was entering a region of rapidly deteriorating weather
in which VFR flight was most improbable and severe
turbulence existed. T he pilot, in fact , had con sidered
diverting and had examined the charts for Bathurst and
Cootamundra. H owever, against all th e evidence with
which he had been p resented in fl ight , he decided to
press o n to check th e dust storms for himself.
Very shortly afterward s, he found that conditions in
the dust were precisely as reported, a nd he had to
descend further to retain visual contact with the
ground. E xtreme turbulence made con trolled fligh t
difficult. As usually happe ns in weath er-related
accidents, the pilot suddenly realised that he was
rapidly losing con trol of the situation. H e found himself
below 1000 fee t AGL still descending and with the
a ircraft pitching and rollin g violently.
Full power was applied, but it was too late: the pilot
no longer had the capabili ty of extricating hi mself from
his fr ightening situation. W ith the stall warning horn
blowing and 85 knots indicated on the AS!, the pilot
called out to his p assengers ' I 've lost it!'. Shortly
afterwards the aircraft sliced through a two-strand
power line, h it the grou nd, bounced over a ditch and a
road and slid through a fence before finally coming to
rest on its belly. Remarkably, all six occupants escaped
unscathed.
*
*
*
)
\ t,(
DUST STORMS
There is no need to labour th e most important safety
message here: the details of the accident graphically
illustrate the folly of pressing on regardless of
conditions. I t does need to be said that, by and large,
meteorological forecasts in Australia are very good ; but
this in no way absolves any pilot from reacting to actual
rather than predicted conditio ns.
Two other safety-related points are worth
m entioning. It was fortunate that nobody was injured,
and even m ore so for one of the p assengers who d id not
have his seat belt fastened and who was thrown out .of
the aircraft as the back door flew open o n impact.
Fu r ther , it was later established that the Cherokee had
been 18 7. 7 kg overweight on takeoff - a 12 per cent
increase over the maximum a llowable weight. The
a ircraft was still 88 kg overweight at th e time of the
accident, and this would have degraded the aircraft's
climb performance when, with full power applied, the
pilot was una ble to gain altitude when he needed to do
so to recover from the dangerous situati on in .w hich he
had p laced himself, his passengers a:nd h is aircraft •
Aviation Safety Digest 122 I 17
�Look closelv, and spot the defect
p lagued by in termittent thunderstorms, entrants who
participated after about 1300 hours only had to locate
nine items because the hydraulic leak was finally
washed away! T he Bureau passes on its congratulations
to the win ners : Mr Dave Johnson of Yarralumla ,
A .C.T., an d Mr Michael Winton of Para H ills, S.A.
P ar ticipants have already been advised of the results
and their own scores, but readers may be interested in
the overall detection rates , which were as follows:
•
•
•
•
•
•
•
•
•
•
•
tow handle
screwdriver
flat oleo
split pins
propeller spinner
anti-collision beacon
· hyd raulic leak
H F antenna
wheel chocks (C anberra)
corrosion (Man galor e)
self-locking n ut aileron/flap
52%
34%
51 %
42%
72%
74%
40%
51 %
33%
5%
64%
The flying experience of the p articipating pilots
varied from 1 hour to , in one case, 11 OOO hours,
althou gh the average was in the range 130-200 h ours.
Individual results ranged from poor to excellent. Two
1 hour pilots successfully identified five defects while a
•/LOTS
WIN TWO YfARS FREE SUBSCRIPTION TO
AUSTRAUAN FLYING MAGAZ/Nf,
500 hour pilot located only one item.
While the defects were entirely detectable by an
external visual inspection, participants needed to get
down on their hands and knees to locate some of them.
Those who failed to bend their backs missed the
screwdriver (which was partly obscured by the ,
propeller), hydraulic leak and self-locking nut.
Of the 51 per cent who spotted the oleo problem,
m any said that the starboard oleo was over-inflated
rather than the port oleo bein g deflated. While the
detection of an oleo problem was considered sufficient,
how many pilots would have cor rectly identified the
deficiency if both oleos were equally deflated?
Many pilots quite rightly identified other items which
had not been rigged on the aircraft, such as dirty
windscreens and nicked propellers. One intrepid aviator
even suggested that he was concerned about the
serviceability of the aircraft due to a small cobweb in
the tailcone!
The Bureau believes the exercise was both rewarding
and educational for those pilots who took p art, b u t also
wonders how many of the defects would have been
located if the pilots were not advised of the number to
locate and were advised to complete the ·pre-flight in the
u sual time spent on checking an aircraft - 5- 10
minutes •
Churchill Fellowships
Articles in the D igest often highlight the importance of
conductin g a thorough pre-flight inspection and the dire
consequen ces of overlooking this critical part of flight
preparation.
Despite appalling weather at Canberra and m a rginal
weather at Mangalore, almost 100 pilots participated in
pre-flight competitio ns conducted by the Bureau of Air
Safety In vestigation at the Canberra Aero C lub Open
D ay in March and the Sport Aircraft Association 's
fly-in at Mangalore over E aster.
The competitions, which were sponsored by A ustralian
Flying, challenged pilots to locate ten defects specia lly
bu ilt in to an aircraft. The pre -co mpetition briefing for
each participant explained that the aircraft had been
daily and pre-flight inspected by the pilot-in-comm and
and that the p ilot was about to b oard the aircraft, start
the en gine and comm ence taxiing. H owever, each
competi tor was then advised that there were ten
'defects' which either m ade the a ircraft un serviceable or
unsuitable for fligh t and competitors were challen ged to
locate the item s.
The aircraft used were a PA32-300 provided by
Vee-H Aviation in Canberra and a PA28-1 40 provided
by Mr Ian D ickson , a m ember of the SAAA, at
M an galore . The prize fo r the most correct entry fo r
ea ch competitio n was 2 years free subscriptio n to
A ustralian Flying, dona ted by the publish ers of the
magazine .
18 I Aviation Safety Digest 122
With two exceptions, the defects which were r igged
into the two aircraft wer e the sam e, namely:
•
•
•
•
•
•
•
•
•
•
tow handle left attached to the nose wheel;
screwdriver in the engine compartment;
port m a in wheel oleo flat;
split pins m issing fro m main cabin door h inge bolts ;
two screws m issing from propeller spinner;
nut and bolt securing anti-collision beacon len s
missing;
h ydraulic leak sta rboard brake;
loose HF a ntenna;
wheel chocks left in place (co rros ion starboard wing
at Mangalore); and
self-lockin g nut missing on starboard inboard flap
hinge bolt (aileron hinge bolt at Mangalore).
The Bureau believes that the exercise was well
worthwhile and n early all participants, includin g those
who decided against handing in their entries beca use
they could not locate what th ey bel ieved to be sufficien t
items, said that they would scrutinise aircraft a good
deal m ore carefully in the futu re. Some participants in
fact spen t in excess of an hour checking the aircraft for
the chance to win th e prize . This r a ises th e question as
to whether they wou ld spend the same amount of time
undertaking a pre-flight to save their lives .
N o one spotted a ll ten defects, but three at Canber ra
a nd o ne at Mangalore successfully iden tified nine.
H owever, because the C anberra competition was
The Winston Churchill M emorial T rust was
established in Australia in 1965, the year in which
Sir Winston Church ill died. The principal object of
th e Trust is t o perpetuate and hono ur the memory of
Sir Winston Churchill by the award of Memorial
Fellowships known as 'Churchill Fellowships' .
The aim of the Churchill Trust is to give
opportuni ty, by th e provision of financial support, to
ena ble Australians from all walks of life to undertake
over seas study, or an investigative project, of a kind
that is not fu lly available in Australia. This
opportunity is provided in fu r therance of Sir
Winston C hurchill's m axim that: 'with opportunity
comes r espon sibility'.
T here are no prescribed qualifications, academic
or otherwise, for the award of a Churchill
Fellowship. Merit is the primary test, whether based
on p ast achievemen ts or demonstrated ability for
future achievement in a ny walk of life. T he value of
an applicant's work to the community and the extent
to which it will be enhanced by the applicant's
overseas study project are important criteria taken
into accoun t in selecting Churchill Fellows.
However, Fellowships will not be awarded in cases
wh ere the prim ar y purpose of the a pplication is to
enable the applicant to obtain higher academic or
formal qualificatio ns nor to those in a vocation which
offers sp ecial opportunity for overseas study .
Churchill Fellows are provided with a return
econom y-class over seas air-ticket and an Overseas
Livi ng Allowan ce to enable them to undertake their
approved overseas study project. In special cases they
may also be awarded supplementary allowances
including D ependants' Allowance. Fifty-one
Churchill Fellowships were awarded for 1984.
All Churchill Fellows are presented, at an
appropriate ceremony, with a certificate and badge
identifying them as such. T he certificate bestows
upon the recipient the prestige of being a Churchill
Fellow and, while a Fellow is overseas, serves to
open many doors that would not otherwise be
opened to a private individual. T his could provide
an opportunity for a member of the aviation industry
to help others in aviation as a result of their
endeavour and t he assistance provided by a
Churchill Fellowship.
Applications
The Churchill Trust is now calling for applications
from Australians , of 18 years and over, from all
walks of life, who wish to be considered for Churchill
Fellowships tenable in 1986.
Completed application forms and reports from
three referees must reach the Churchill Trust by
29 February 1985.
People wishing to be considered for a Churchill
Fellowship should send their name and address now
with the request for a copy of the Churchill Trust' s
information brochu re and application forms to: The
Winston Churchill Memorial Trust (M),
PO Box 478, Canberra City, A.C.T. 260 1 •
Aviation Safety Digest 122 I 19
�Heat stress
As all Australian pilots would be well aware , Australia
is a country of climatic extremes with temperature
zones ranging from tropical to alpine environmen ts.
Associated with these zones are extremes of
tempera ture , humidity and high solar (radiant) heal
loads.
Every.one has experienced the discomfort of getting
into a closed car which has been standing in the sun on
a hot day. Dri vi ng in hot weather is unpleasant, tiring
and generally leads to short tempers. Most importantly,
it can degrade your driving performance . A burst of hot
weather is usually associated with a spate of road
accidents.
H ave you ever considered that the same situation
exists in your aircraft on a hot day? A combinat ion of
high ambient temperatures, clear cloudless skies, large
expanses of perspex a!1d the 'heat soaking' or the
aircraft all lead to extremely high cockpit temperatures.
' H eat soaking' occurs when the aircraft structure
approach es the ambient temperature. Unde r such
circumstances surface temperatures in the aircraft may
reach extremely high levels and the cockpit air
temperatures may approach the radiant temperature.
One practical approach to this problem has been to
specify that conditions in cockpits should be such as to
m aintain the skin temperature of the pilot as close to
33 °C as possible. This skin temperature is that which
most people consider 'comfortable' or at which a
sensation of comfort is reported. Unfortunately, given
the limited .capacity of current aircraft a ir-conditioning
units and the extremely high temperatures reached in
20 I Aviation Safety Digest 122
around 15-25 degrees h igher than the outside air
temperatures. Th is means that even on a relatively mild
day, cockpit temperatures may be extremely high. For
example, if the outside temperature was 25 °C, then the
cockpit temperature of a heat soaked aircraft was
anythin g up to 50 °C. Temperatures out on the tarmac
were gene rally around 5 °C hotter than the
temperatures reported by the meteorology people. (This
results from the absorption of heat by the grey asphalt
surface and the reflection of heat back from the
tarmac.) Additionally , surface temperatures in the
ai rcraft cockpits were very high. In some cases they
were hot e nough to cause burns if touched.
heat soaked aircraft, such specifications become for all
practical purposes meaningless. Additionally, some
a ircraft were never designed to operate under such
extremes of temperature, and a requirement that the
cockpit temperature be maintained at 28 °C may be
interpreted as (for example, under Eu ropean design
conditions) a requirem ent for an e fficien t heating as
opposed to cooling system! Wh ere effi cient cooling units
have been installed the ir power consumption may be
such as to limit their use during the hotter regimes of
flight , e.g. takeoff and landi ng.
These factors raise the obvious question of just how
hot does it get in aircraft cockpits and what is the effect
on the pilot? A recently conducted series of trials
measured temperatures in ai rcraft cockpits and the
body temperatures of pilots in Western Australia during
hot, summer operations. While this study was aimed
primarily at the problems o f m ilitary fl yin g under these
conditions, the cockpit temperatures were the same as,
or very similar to, those found in GA aircraft: that have
been standing on the ground or ai rfi eld heat soaking
before use and those involved in low level, hot weather
operations such as aerial appli cation, aerial mustering
or glider towing .
The rises in pilot body temperature which accompany
high cockpit temperatures are o f concern to all pilots
fl ying under these conditions because increased body
temperature can affect both the physiological well-being
and the flying ability of the pilot.
The Western Australian research showed that the
temperatures in the heat soaked aircraft cockpits were
The hottest parts of all flights in the experiment were
iden tified as grou nd standby prior to takeoff and within
the circuit area before landing. G enerally, cockpit
tem peratures peaked prior to takeoff and rose again as
the aircraft re -entered the circuit area prior to landing.
The highest cockpit temperatures were recorded at
takeoff or land ing.
The hottest phases of the fligh ts therefore
correspon ded to high workload sections of flights, where
the pilot had to pay maximum atten tion to the task in
hand .
On all lo ng, hot, low flights the body temperature of
the pi lots rose. The magnitude of this rise was 1-2°C
a nd was dependent on the average inflight temperature,
duration of the flight and, to some extent, the mass of
the p il ot. One or 2 ° may not sound like much;
however, your body is designed to operate within a
very narrow temperature range a nd once the
temperature goes outside this range, even by a small
amount in either direction, the effects can be severe.
The most easily observable physiological response to
the high temperatures was the degree of sweating by
pilots. If pilots had completed several low, hot flights of
around 1 hour duration each, then mass losses of the
order of 5 pounds were common, despite the fact that
they were encouraged to drink between sorties. This
dehydrat ion, caused by sweating, is important because
it impairs both body temperature regulation and work
capacity. If the fluid loss caused by sweating is not
r eplaced (i.e . dehydration ), less body water is
subsequently available to sustain further sweating a nd
sweat rates are accordingly reduced. Therefore, during
dehydration, body temperature will be h igher than
norma l because a reduced sweat rate lessens evaporative
heal loss and the cooling capacity of the body.
The thirst mechanism is inadequate to preven t
dehyd ration occurring. First, the mechanism only
becomes operative when total dehydration exceeds 1 per
cent of body m ass. Second, only one-half to two -thirds
of fluid loss is replaced voluntarily, e .g. a 155 pound
person would need to lose 1.5 pounds before feeling
thirsty and only half this mass loss would be replaced by
drinking an amount sufficient to satisfy the feeling of
th irst.
To minimise the effects of heat stress the pilot mu st
remain fully hyd rated and must therefore consciously
force fl uid intake past the point of feeling 'satisfied' .
Addition ally, fluids such as tea or coffee should be
avoided as they are diuretics. (D iuretics are fluids
which increase the level of water loss by increasing the
urine volume and output. They merely add to the
effects o f any pre-existing dehydration.)
As a rule of thumb, it generally took the pilots about
twice as long to cool off after a hot sortie as it did for
them to heat up. This meant that if a flight lasted
50 minutes it took nearly 2 hours for body temperatures
to return to resting levels. Adequate rest periods are
therefore essential if sustained operations are to be
undertaken during hot weather flying. Strenu~us
activity should also be avoided, as this also increases
body temperature and the level of dehydration.
Recent overseas experience has shown that heat stress
may compromise the 'hands-on' ability of the pilot to
actually fly the aircraft. In a simulator study at the
R oyal Air Force I nstitu te of Aviation Medicine at
Farnborough , it was shown that subjects exposed to
hea t stress flew the simulator much less accurately and
made control errors of greater magnitude than under
non -heat-stressed conditions. Further, such control
failures were characterised by their unpredictability.
Other simulator studies have demonstrated that
increased body temperatures arc associated with
increased errors of speed, altitude and deviation from
required flight headings. Heat stress may also cause a
narrowing of attention and directly affect a student
pilot 's learning ability . Studies at the United States Air
Force School of Aerospace Medicine have indicated that
impaired pilot performance under heat stress is
associated with new or emergency conditions in which
previous practice would be limited.
H igh levels of skill may lessen the effects of heat
stress on performance and affect skilled and unskilled
workers to different extents. In addition, heat stress
may also combine with the effects of other stressors
such as fatigue , sleep deprivation, etc., to produce
much more severe performance redu ctions than if each
stressor was present in isolation . Under such
circumstances the accident potential is increased and
flying skills may be degraded withou t the pilot being
aware of any changes in performance.
Pilots who are particularly vulnerable to the effects of
heat stress are those operating continuously at low level
in hot conditions where sustained attention and high
levels of concentration are required, e.g. the
agricultural pilot or the aerial mustering pilot. (Note
that these kinds of operations are those which are also
most susceptible to the effects of skill fatigue - see
A viation Safety Digest 121.) Consequently, while heat
stress by itself may not be a sufficien t stressor to result
in an acciden t, if it is combined with the effects of
dehydration, lack of sleep or fatigue, the accident
potential may be increased.
Heat stress: the lessons for pilots
The lesson to be learned from all of this is tha t if you
are flying in hot sum mer conditions, be aware of the
potential for heat stress to affect your ability to fly the
aircraft and do not ignore it.
• As a rule of thumb, temperatures in a heat soaked
aircraft may be 15-25 °C higher than ambient
tern peratures.
• Remember that heat soaking may occur even on a
cloudy day if your aircraft has been standing outside
for a few hours .
• Even slight levels of dehyd ration may affect
performance, and fl uid intakes should be forced past
the point where you feel you couldn't drink any
more.
Aviation Safety Digest 122 I 21
�• Adequate rest periods are essential and strenuous
activity should be avoided if sustained low level
flying activities are to be undertaken in hot weather.
*
*
The following accident is believed to reflect the
combined effects of lack of sleep, heat stress and
strenuous activity levels during hot weather.
During aerial mustering operations , a helicopter pilot
was fl ying from one mob of cattle to find another. He
reported crossing a rocky ridge when he spotted cattle
to his right and behind him. The pilot checked his RPM
and executed a 30 ° bank turn to the left through 180 °
at 20 fee t AGL and at about 60 knots.
After completing the turn , which put him downwind,
the pilot felt the helicopter sinking. H e applied power
and collective controls but the aircraft, now flying
downslope , was reported to be unresponsive and
continued to sin k, striking its tail rotor on the ground.
The chopper then rotated three or four times to the
right and crashed heavily onto its skids.
In the absence of any d etected contributory aircraft
unserviceability, the following causes of the gro und
strike were considered:
Overpitching
The pilo t reported that he did not check his rotor RPM
d uring or after the turn (a necessity for low level
operations), and especia lly when the sink was apparent.
A decay in rotor RPM during the turn would cause a
lack of collective response when attempting to counter
the appa rent sink and a p ersistence with full collective
would rapidly induce an overpitch situation from which
no recovery would b e possible at low altitude.
Such a n over-controlled r espon se is characteri stic of
skill fatigue, where gross rather than fine movem en ts
are u sed to try to correct such situa tions.
On this day the pilot h ad been flying for 9.5 hours
and 8 of these hours had been spent in aerial mustering
activities. Aerial mustering req u ires h igh levels of
sustained attention and flying skills, especially during
low level operations in difficult terrain. It is likely,
therefore, that the pilot may have been suffering, to
some extent, from skill fatigue following a long period
of mustering.
Judgment of ground clearance
When turning and flyin g downslope, the p ilot would
judge ground clearance from his forwa rd view.
However, the tail of the helicopter would be upslope at
a much reduced ground clearan ce.
The previously mentioned research at RAF
Farnborough demonstrated the association between heat
stress and increased errors of controlling altitude, speed
and flight headings. It is considered likely that heat
stress may h ave affected the pilot's ability to accurately
judge his ground clearance. Ambient temp eratures
during the muster were around 30 °C. Under such
circumstances cockpit temperatures may have been as
high as 45-50 °C .
On the day of the accident the pilot had drunk only
one cup of sweeten ed tea, despite the long working day
in the heat. O n the day prior to the accident he had
eaten only an apple and an orange. D ehydration must
therefore be considered as an addi tional factor which
m ay have affected his flying ability. Flying in hot
conditions with the windows and doors open would
have resulted in high and sustained water losses through
the evaporation of sweat. It is likely, therefore, that the
pilot's judgment criteria m ay have been altered without
his being subjectively aware of any change.
While each of these factors in isolation m ay have
been insufficient to result in an accident, the combined
effects of operating long hou rs in hot cond itions,
fatigue, dehydration and the nature of the flying task
contributed to the even tual accident •
In brief
As the Boeing 727 started its approach to an airport
in the U.S.A., the Tower advised that the weather
had deteriorated from a visibility of about 2 miles
with a cloud base of 800 feet to an R VR near 4QOO
metres with a cloud base of 100-300 feet. The First
Officer was flying and made a good ILS approach, on
centreline and on glideslope. At Decision Height the
Captain called 'Approach lights in sight - continue
the approach'. At ·about 150 feet the First Officer
(still flying) looked up and although the approach
lights were in view the runway was not yet in sight.
Then the Ground Proximity Warning System
(GPWS) glideslope wa rning came on and the
glideslope deviation indicator started moving to a full
fly-up command. With the pressure altimeter reading
less than 100 feet the Captain called 'Go around'.
This was initiated without further delay and with no
incident. After the go-around the Tower reported
that R VR had rapidly dropped below 2000 metres
while vertical visibility had fallen to less tha n 100
feet.
22 I Aviation Safe ty Digest 122
The Captain later commented that the GPWS
probably saved them from ploughing into the
a pproach lights. As to the sudden increase in descent
rate, this was the First Officer 's first experience with
rapidly deteriorating visibility during an instrument
approach. He had read about the problem and seen
films on the difficulties of t ransitioning from
instrument to visual flight, but found the task of
translating theory into practice a handful.
*
*
*
Almost immediately after takeoff, both engines of a
Piper PA-23 lost power and a forced landing was
made in a field. The aircraft had been refuelled from
a ground fuel tank that had run dry during the
process. A preliminary examination indicated that
two of the drain sumps in the wings of the aircraft
were clogged with foreign matter, probably from th e
bottom of the ground fuel tank e
•Drink plenty of fluids
water is best-fluid intake must be forced ·drink more
than dictated by thirst alone
'
•Aim for adequate post flight recovery
body temperature remains above normal for at least
one ho~r even _though you may feel comfortable after
a few minutes in a cool environment
~
�
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122
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1984
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https://collections.heritageoftheair.org.au/files/original/10ec68fb3eacc4846519899d48010bfc
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Text
�Contents
3
Helicopter wake turbulence
Helicopter wake turbulence
Publicity needs to be given to the fact that wake
turbulence from a moving helicopter can be more
severe than that from a fixed-wing aircraft of the same
weight.
5 Wake turbulence quiz
6 The experience factor
A review of an agricultural accident demon strates that
highly qualified and experienced pilots can still fall
prey to the most basic errors if they fail to observe the
fundame ntals of safe operations.
8 Auxiliary fuel pumps
As with other aircraft systems, it is a dangerou s
practice to apply a common set of procedures for the
operation of auxiliary fuel pumps across the range of
GA aircraft.
10
Preventing engine power-loss accidents
The majority of engine failures are att ributable to the
human rather than the mechanical component of the
system.
12 Supervision and self-discipline
In numerous accident investigations it emerges th at
deficient s upervision was a factor in prejudicing ai r
safety. Supervisors have a responsi bility to assist pilots
to develop a high level of self-discipline.
13
Unrated in
IMC
(pilot contribution)
16 Carburettor icing
18 The costs of aircraft accidents in Australia
Report of a study in the Bureau of Air Safety
Investigation on the economic cost to the community
of aircraft accidents.
19 Check your fuel contents -
visually
The pilot of a Piper PA-18 was forced to land on a road
after an e ngine failure . The AVGAS had been drained out
overnight by a th ief.
conditions. As a guide, experiments have sho'wn that
vortices close to the ground will typically last from 1 to
approximately 2 minutes, while at higher altitudes the
vortex life may be as long as 5 minutes. Depending on
the generating aircraft's speed, vortex trails may vary
in length from less than 2 nm to up to 5 nm.
Aviation Safety Digest is prepared by the Bureau of Air Safety
Inves tigation in pursuance of Regulation 283 of the Air Naviga·
tion Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to
Australian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Australian civil aviation.
Helicopters
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the free list experiencing problems with distribu·
tion or wishing to notify a change of address should write to:
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 1839Q, Melbourne, Vic. 3001.
Aviation Safety Digest is also available on subscription from
the Australian Government Publishing Service. Inquiries and
notifications of change of address should be directed to:
Mail Order Sales,
A us tralian Government Publishing Service,
G.P.O. Box 84, Canberra, ACT 2601
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Reader contributions and correspondence on articles should
be addressed to:
The Director,
Bureau of Air Safety Inves tigation,
P.O. Box 36 7,
Canberra City, ACT 2601.
© Commonwealth of Australia 1984
ISSN 0045-1207
R83/1005 Cat. No. 84 0024 X
Printed by Ambassador Press Pty. Ltd.
51 Good Street, Granville, N.S. W. 2142.
20 Skill fatigue
Two accidents whi ch occurred during low-level
helicopter operations drew attention to the
phenomenon of skill fatigue, to which all pilots are
s usceptible.
23 The good olde days ...
Covers
SA330J Puma helicopters operated by Mayne-Bristow
Helicopters Ply Ltd from Broome and Karat ha, W.A., in
s upport of offshore oil and gas drilling operations.
2 I Avia tion Safety Diges t 121
I
Most pilots are aware that the win gtip vortices
generated by large fixed -wi ng a ircraft can present a
hazard to other a ircraft which encoun ter them,
particula rly during takeoff and landing. The force of
this wake turbulence can be gauged by the fact that
some years ago overseas a D C-9 - a la rge aircraft itself
- crashed while m aking a n approach to land behind a
DC-10, killing all on board. The investigation
concluded that the probable cau se of this accident was
a n encounter with the trailing vortex of the DC-10,
resul ting in a n involun tary loss of control.
For those who have become a little hazy on wake
turbulence, the key points to remember, in general
terms, are as follows:
• Wake turbulence is u sually worst behind a large,
slow ai rcraft which is in a clean configuration.
• The turbulence descends at about 500 feet per
minute to about 900 feet below and behind the
generating aircraft.
• I t is most persistent over an a irfield where there is a
5 kno t crosswind.
• The greatest loss of control wi ll occur when a n
aircraft climbs on the same heading throu gh the
wake of the gene rating aircraft.
• While wake turbulence is m ost dangerous to a ircraft
which are taking off or la nding, aircraft encountering
it at cruise a ltitudes m ay still experience loss of
con trol , a irframe overstress a nd, in t he case of jets,
en gine compressor stall .
It is also important to remember th at the lifespan and
size of vortices are significantly affected by a mbient
The hazards presented by the downwash of a stationary
helicopter are generally well known. Some pilots,
however, seem to be unaware of the fact that moving
helicopters can also generate severe wake turbulence
similar to the wingtip vortices of fixed-wing aircraft.
There have been several instances of helicopter wake
turbulence cau sing accidents. The following report
illustrates this:
A light twin-engine aircraft was ma king an approach
to land behind a reasonably large (4700 kg AUW)
helicopter. The helicopter had completed its approach
and was air taxiing to the left of the active runway.
When the light aircraft was on short final app roach...
over the threshold and a bout 300 metres behind th~
h elicopter, its starboard wing dropped suddenly; before
the pilot was a ble to take fu ll corrective action the
aircraft impacted the runway h eavily, nose first.
D amage was substantia l. Wind velocity at th e time was
30 degrees off runway heading from the left at 5 knots.
From an assessment of the evidence the possibility
exists that the light twin m ay have encountered wake
turbulence gen erated by the helicopter.
Pilots must appreciate that the wake turbulence from
a h eavy helicopter can be significantly more severe than
that from a fixed-wing aircraft of the same weight. As a
rough guide, a 9000 kg helicopter on approach at
40 knots generates about the same vorticity as a
27 OOO kg fixed-wing a ircraft on approach at 120 knots.
Pilots sh ould observe the sam e avoidance techniques
for hel icopter turbulence as they do for that produced
by fixed-win g types:
• land beyond the helicopter's touchdown point;
• take off before the helicopter 's takeoff point; and
• remember that the vortices will drift downwa rds a nd
behind the h elicopter at all times when it is airborne.
The m a in point to appreciate is that a large helicopter
can be a formidable vortex generator , and should be
given a wide berth.
Comment
Clear guidance on a pilot's responsibility for avoiding
wake turbulence is given in the VFC and AIP. To quote
the VFG:
When the tower contro ller thinks that the turbulence from
the wake of a preceding a ircraft would be a hazard, he will
advise you:
' CAUTION -
WAKE TURBULENCE'.
H e cannot, however, assume respon sibility for issuing this
advice .a t all times as he cannot p redict accurately the
occurrence of wake turbulence. You should, therefore , be
on the alert fo r this hazard , especially when taking off from
an aerodrome where heavy traffic (not necessarily turbo-jet
aircraft) is operating •
Aviation Safety Diges t 121 I 3
�{
Wake turbulence quiz
A Lockheed Hercules flew through smoke from a sm oke generator fixed to a mas t to produce this visible wingtip
vor tex. The intensity of the vortex is obvious.
Listed below are 10 multiple-choice questions originally published in Lockheed's Flight Operations
Digest and reported in UK Flight Safety Focus and N:z; Fl ight Safety.
Check your answers against those on page 9. Each correct answer is worth 10 points. If you achieve
a maximum score of 100 poi nts .you have a good wake turbulence knowledge.
1 . When dep arting behind a large cargo aircr aft,
which of the following winds would result in the
m ost per sistent runway turbulence?
(a) calm winds
(b) direct headwinds
(c) 5 -knot crosswind component
( d) 10-knot crosswind component
2. A jet ai rcraft departs on runway 36L in calm
condit ions. H ow lon g would it take wingtip vortices
to reach runway 36R if the distance between the
two runways is 305 metres ( lOOOft)?
(a) Y2 minute
(b) 1 minute
(c) 1 Y2 minutes
( d) 2 minutes
3. When does a dep arting aircraft start producing
wingtip vortices?
(a) at the start of the takeoff roll
(b) at a speed of approximately 60 knots
(c) at point of rotation
( d) when the landing gear and flaps are raised
4. W h ich of the following combination s of speed,
weight and aircr aft configuration generates the
greatest amount of wake turbulence?
(a)
(b)
(c)
( d)
i
Airsp eed
slow
slow
fast
fast
Weight
heavy
heavy
heavy
heavy
Configuration
flaps down
clean
flaps down
clean
5. W hat is the sink ra te of trailing vortices from a
large ai rcra ft at altitude and at what hei ght below
the generating aircraft do they stabilise?
(a) 500 fpm to 900ft below
(b) 500 fpm to 500ft below
(c) 1000 fpm to 2000ft below
( d) 1 OOO fpm to ground level
6. When taking off behind a departing jet or turbop rop a ircraft, the recommended technique is to:
(a) Delay liftoff as long as possible to gain excessive
airspeed for penetration of the vortices.
(b) Plan to lift off before the rotation point of the
4 1 Aviation Safety Digest 12 1
departing aircraft and continue climb above or away
from its flight path.
(c) Climb to 500ft, level off and turn so as to cross the
vortex path at a 90 degree angle.
(d) A djust the flight path so as to penetrate the vortex core
500ft below the departing aircraft.
7. Vortex cores can range up to 9 metres in diameter
with tangential velocities of up to 85 metres/ sec ,
depending on the size, speed and configuration of
the generating aircraft. How would you describe
the subsequent behaviour of t he vortices?
(a) The cores rapidly expand until they overlap and
dissipate.
, (b) T hey stay very close together with little expansion until
they break up at distinct intervals.
(c) They gradually reduce in size until dissipation.
( d) Depending on the atmospheric conditions, they
sometimes increase or decrease in size.
8. U nder what wind conditions will the movement of
vortices in ground effect cause the greatest h azard
to following aircraft in the touchdown zone?
(a) light and variable conditions
(b) 5- 10-kt quartering headwind
(c) light quartering tailwind
( d) strong headwind
9 . Which of the following encounters with wake
turbulence would probably result in the greatest
loss of control of the penetrating aircraft?
(a) crossing the wake at a 90 degree angle
(b) climbing through the wake at a 90 degree angle
(c) climbing through the wake on the same heading as the
generating aircraft
( d) flights 1 OOOft below the generating aircraft
10. When departing or landing behind a large turbo-jet
aircraft that has executed a missed approach or
touch-and-go landing, how long should you wait
before commencing takeoff or approaching to land?
(a) 30 seconds
(b) 1 minute
(c) 3 - 4 minutes
(d) 5 - 6 minutes •
Answers on page 9
Aviation Safety Digest 121 1 5
�The experience factor
Experience is righ tly recognised as being one of the major factors contributing to a pilot's
competence. Yet it is not an end in itself, for as the following accident review shows, highly
qualified and experienced pilots can still fall prey to the most basic errors if they fail to observe the
fundamentals of safe operations.
A pilot was involved in spreading supcrphosphate in an
Airtruk. While his agricultural expe1-ience was limi ted ,
amountin g to 350 hours total and 40 hours on type, his
overall experien ce level was substantial , consisting of
2700 ho urs and a Grade One instructor rating.
A second Airtruk was working on the same property :
it was being flown by a piJot with about 10 OOO hours
agr icultural fl ying time . Bo th aircraft were operating
from the sam e airstrip , and work progressed
uneventfully durin g th e morning , with breaks being
taken for morning tea and lunch . The aircraft were
refuelled during lun ch and operations recommenced.
On the third flight of the afternoon the pilot who held
the instructor grading was turning on to hi s initial
spre ading run at an altitude of about 150 feet AGL
when he felt hi s aircraft start to 'shudde r ' . H e began a
turn to the right towards lower ground and at the same
time appli ed full power and dumped th e load of
superphosphate. However, the aircraft descended
rapidly . Rea lising tha t ground impact was unavoidable
the pilot tri ed to control the crash , but with little
success. The aircra ft hit the ground nose first; the
propeller and noscwheel were torn off before the aircra ft
cartwheeled for 30 me tres. It came to rest right way up
with the cockpit virtually intact but the aircraft
destroyed .
The terra in a round the crash site was hilly . The
aircraft had impacted on a southerl y heading on a 5
degree rising slope, and a short distance further on, the
ground rose abruptly by another 400 feet. Wind
velocity was from the no rth-west at 5-10 knots and the
temperature was 23 °C.
The cause of this accide nt was straightforward:
notwithstanding his experien ce and qualification as an
instructo r , the pilot had allowed hi s a ircraft to stall.
An examina tion of the Pilots Handling Notes fo r the
Airtruk showed tha t , for the aircra ft 's weight a t the
time of the accident, the fl ap s-up stalling speed was 56
knots. In subsequent discussions th e pilot stated that he
had been maintaining an l AS of 78 knots . However , the
stalling speed of 56 knots was, of course , applicable
only to straight and level flight, and in thi s ca se the
pilot was banking his aircraft to line up o n the
spreading run - during which he fel t his aircra ft
'shudder '.
Assuming a n a ngle of bank of between 40 degrees
and 60 degrees was used , the lo ad factor on the aircra ft
would h ave increased by between 1. 4 and 2.0. As
stalling speed increases proportiona tely to the square
root of the load factor, the stal l speed in this case wo uld
have risen to between 64 and 79 knots. Further , the
turn o n to the spreadin g run was made over rising
terrain (see diagram ) a nd it seem s possible tha t airspeed
may have inad ver tently bee n allowed to decay sli ghtly
as a con stant height AGL was maintained.
In short, the a ircraft was bein g flown close to the
ground a t a speed wh ich provided no m ar gin for
6 I Aviation Safety Digest 121
manoeuvring. T he 'shudderin g' wh ich the p ilot felt was
pre-stall buffe t.
The message here is simple, but that fact does not
diminish its importance; on the contrary, it highli ghts
the truism t hat aeroplanes and the physics of flight are
no respecters of experience, qu alifications or repu tations
- if you fail to observe the basics, it CAN happen to
you.
*
*
*
A further interesting point arisin g from this occurrence
revolves aroun d the ci rcuit patterns flo wn by the two
pilots. At various times before the acciden t both pilots
had flown this circuit. H owever, the pilot with 10 OOO
hours agricultural time had flown a p att~ rn which went
further down win d on the circu it than that flown by the
pilot who eventually crashed (the circuits are marked as
Pilot A and Pilot B respectively on the diagram).
By fl ying further downwind, Pilot A o bviated the
need to start the turn on to the spreading run while
over rising groun d , i. e. unlike Pilot B, h e d id not have
to climb while in the turn to m a intain a constan t height
AGL. Unfortuna tely thi s procedure was no t discussed
between the two pilots : given the experien ce level o f
each , perhaps they did not feel any need to compare
techiques. Yet, clearly, the p attern flown by Pilot A was
better planned and safe r .
In the sometimes demanding and unforgiving
business o f aviation, no pilot can afford to take
anything for granted . It costs not hing to com pare ideas
or no tes, and while the tho ughts or advice of others
m ay often be superfl uous, none of us gets it righ t al l the
time - regardless of experi ence . Pilot s also need to
remember that, as this acciden t showed, experience in
one sphere o f fl igh t opera tions is not necessarily
transferable to another. This p oint is particularly
pertinent for supervisors •
Wind direction
-- -
-
~
-- -
Valley
-
/
- - -
-
-
- - -
-
-
- -
- -
Aircraft climbed in valley
I
I
0
Flight path
Pilot A
-
-
- -
--
.....
'
\
\
Shed
Flight path
Pilot B
Rising ground
l
I
I
Rising ground
5° upslope
+
\
'
Spreading run
11oo · amsl
Accident site
950 · amsl
~
1000-amsl
Top end of
strip
Steep rising ground to large hill
\
\
~
I
Large hill 1600· amsl
Looking back along flight path showing valley and rising
terrain (right).
Aviati on Safety Diges t 121 I 7
�Auxiliary fuel pumps
The engine later o perated satisfactorily in a test rig.
The investigator postulated that the probable cause of
the loss of power was fuel vapour accumulation in the
fuel system - a vapour lock - wh ich could have
resulted in som e degree of in terruption to engine power
output. Turning on the auxiliary fuel pump most
probably would have cleared the vapour lock and
remed ied the situation. I t is also important to note that,
had the loss of power been attributable to failure of the
engi ne-driven fuel pump, then the immediate actions lo
be taken again would have included that of turning on
the auxiliary pump. Significantly, the pilot had minimal
experience on type.
'... The probable cause of the Joss of power was fuel vapour
accumulation in the fuel system - a vapour lock - which
could have resulted in some degree of interruption to engine
p o wer output. Turnin g on the auxiliary fuel pump most
probably would have cleared the vapour lock and remedied
the situation.'
'The pilot . . . energised the EMERG half of the auxiliary fu el
pump switch ... The resultin g grossly over-rich mixture
would have adversely affected the performance of the
aircraf t . . . '
*
Over-rich mixture
The circumstances under which the auxiliary fuel pump fitted to many GA aircraft is used often
seem straightforward - turn it on for takeoff and landing and, when at a safe height in the climb
out, turn it off. However, there can be far more to the operation of an auxiliary fuel pump than that,
as for some aircraft, in an engine-related emergency, the way in which it is used can be e9ually as
important as the way in which controls like the mixture and throttle levers are used. Consider the
following two accidents.
Fuel vapour lock
H aving ju st reached top of climb, a Cessn a 206 p ilot
was setting the cruise configurat ion when the engine
lost power completely. The p ilo t changed fuel tanks and
endeavou red to restart the en gin e, without success.
U n aware that the Emergency Section of the Pilot's
Operati ng H a nd book for the C essna 206 sta tes that the
.a uxiliary fuel pump should be tu rned on following a n
8 I Aviation Safety Digest 121
engine failure in flight, the pilot left it off. Power could
not be restored a nd the a ircraft was destroyed in the
subsequent attempted forced landing into timbered
ter rain.
I t was no t possible to determine with complete
certainty the cause of the engine fa ilure . However ,
there was adequate fuel in the a ircraft 's fuel system and
there were no pertinent defects o r system malfunctions.
i
A Cessna 206 was observed flying close to the ground,
with the engi ne running roughly and emitting black
smoke . Sho rtly after wards the aircraft struck trees and
cartwheeled into a creek bed. A fierce fire broke out
·immediately and engulfed the wreckage. Both occupan ts
were killed.
A gain, it was not possible defini tely to determine the
reason fo r the apparent engine m alfunct ion. Following
an intensive investigation, the air safety investigator
was nevertheless able to reconstruct a likely series of
events.
The aircraft had taken off from a high altitude
runway at close to maximum all-up weight. The
altitude o f the runway was such that it was nor mal to
lean the engine fuel mixture before takeoff. Because the
pilot was unfamiliar with high altitude operations, it
seems possible that he took off with the mixture set at
full rich . Further, the pilot was in experienced on type,
having done most of h is recent flying in Islanders. In
that aircraft, the a uxiliary fuel pump is switched on for
takeoff, but in the Cessna 206 it has to be off.
Assuming that in this instance the pump was
e rroneously selected on, then, when allied to the setting
of the mixture control, the pilot wo uld have been taking
off with an over-rich mixture.
Some comment on the mechanics of the Cessna 206
auxilia ry fuel pump is necessary here. I t is controlled
by a yell ow a nd red split-rocker type switch. The yellow
righ t half of the switch, which is labelled START, is used
for normal starting, m inor vapour purging and
co ntin ued engine operation in the event of an engined riven fuel pump fa ilure. It was this part of the switch
which the investigator believed the pilot erroneously
switched on for ta keoff. The red left half of the switch is
labelled EM ERG, and its upper HI position is used in the
event of an engine-d r iven pump failure d uring takeoff
or h igh power operation. This position may also be
used for extreme vapour purging.
To r eturn to the accident, the investigator postulated
th at, because of th e excessively rich mixture the pilot
had set, rough runnin g was experienced on takeoff. T he
pilot incorrectly interpreted this as a problem stemming
from fuel starvation and reacted by energising the
EM ERG half of the auxiliary fuel pump switch . This
would have exacerbated the existing over-rich mixture
to wh ich the e ngin e was being subjected , and would
explain th e black smoke from the engine seen by the
witnesses. T he resulting grossly over-rich mixture
would have a dver sely affected the performance of the
aircraft so that, at the high altitude and high all-up
weight, it would have been unable to avert a collision
with the rising terrain .
*
*
*
Comment
It seems possible that, in the accidents cited, the pilots'
lack of understanding of how to use the auxiliary fuel
pump co ntribu ted to the loss of two lives and two
aircraft. In the la tter accident it seems reasonable to
suggest that the pilot assumed - erroneously - that a
common set of procedures could be used for auxiliary
fuel pumps, regardless of aircraft and engine type.
A comparison of three popular types of light aircraft
is instructive in laying to rest such assumptions. The
aircraft and their engine types are:
• Beech Bonanza A36, Continental 10-520-BA
• Piper P A32-300, L ycoming 10-540-K series
• Cessna 206, C ontinental 10-520-F
T he engines are similar (in the case of the 206 and
the A36, almost identical) in that they have six
cylinders, fuel injection and produce about 300
horsepower . T his might lead pilo ts to believe that they
can observe the same engine handlin g procedures for
each. Yet the procedure for using the auxiliary fuel
pump for the different aircraft types is, in certain
circumstances, quite different. For example, the 206 has
the split-rocker switch for its pump, with a number of
possible settings, while the A36 has a single control
switch, which is either on or off. The PA32 P ilot's
Operating Manual states that the auxiliary fuel pump
(referred to in that manual as the electric fuel pump) is
to be turned on before takeoff or landing, while the
checklists fo r the 206 and A36 stipulate th at the pumps
in those a ircraft should be off.
Summary
The intention in this article has not been to go into a
detailed examination of how auxiliary fuel pumps
operate or how they are to be used in particular aircraft
types. R ather, it has been to draw attention to the fact
that it can be a dangerous practice to apply a common
set of procedures - checklists, emergency actions, etc.
- across the range of GA aircraft. There is, of course,
a large degree of commonality in certain aspects of GA
aircraft operations, but this does not m ean that
procedures which are correct for one aircraft can
automatically be used for another. In this case,
auxiliary fuel pumps provided the example which
proved the point but, clearly, the lesson applies to the
whole spectrum of aircraft systems . There is only one
way - the right way - to operate systems, and that
information, which appears in the Owner's Manual or
Pilot's Operating Handbook, mu st be known by pilots
in relation to every different a ircraft type they fl y •
Answers to 'Wake turbulence quiz'
5. (a)
2. (d)
3. (c)
4. (b)
1. (c)
10. (c)
7. (b)
8. (c)
9. (c)
6. (b)
A viation Safety Digest 121 I 9
�pressu res are with in limits , and it must be completed in
accordance with the manufacturer's instructions (i.e. as
per the P ilot's Oper ating Handbook or the O wner's
Manual). A n engine m ust perform lo its defined
parameters during a runup .
During fl igh t the p ossibili ty of problems such as
overboosti ng o r over speeding arising wili be m inimised
if engine controls are operated smoothly. Power settings
should be made only in accordance with the Operating
H andbook, wh ile con ditions conducive to engine inlet
o r carburetto r icing, and the appropriate remedial
actions, m ust be known.
Pilots will find tha t they will be better able to
app recia te engine ha ndling requirements if they stay
abreast of technical information related to their
aircraft's fuel, oil, engine components, airworthiness
directives, etc.
Fina lly, p ilo ts should exercise the greatest caution
before accepti ng a ircraft for flight with a known engine
defect. Check the maintenance release before flight to
ascertain t hat the aircraft is serviceable, and make sure
tha t yo u mee t yo ur responsibilities to other pilots after
flight by recording all defects so that they can be
rectified by a LAME.
Preventing engine power-loss
accidents
In the three-year period 1979- 81 inclusive there were
135 General Aviation aircraft acciden ts in Australia in
whi ch engine power-loss was a relevant factor. The total
of 135 was about 20 pe r ce nt of all GA acciden ts,
making ' power-loss' the largest single accident fac tor
durin g that period.
It is significan t to note that, whil e losses of power due
to mechani cal malfun ctio n con tinue to occur , th ese are
rela tively few. The majo rity of engine failures a re
att ributa ble to the huma n rather th an the mechanical
co mpone nt of the system. Far too many accident
investigations reveal occurrences such as fuel sta rvation
and operations o utside the lim its o f the power plan t as
relevant factors. T his ar ticle reviews engine power-loss
accident cau ses, a nd makes recommendations as to how
pilots and LAMEs can reduce the poss ibility of such
occurrences.
Fuel system management
Accident causes
Preventable accidents can generally be ascribed to
either pilot or LAME er ror. It w ill be apparent to
read ers that in ma ny of these occurrences there mu st
also be a large element of deficien t supe rvisio n fro m
senior personnel su ch as o pera tions m an agers, chief
pilots or flyin g instructors, and chief engineers .
Com mon pilo t er rors incl ude the fo llowin g:
• I n adequate syste ms knowledge. If a pilot has a n
inadequate knowledge of his a ircraft's po wer p la nt
lim ita tion s, then he is likely to o perate the engine
ou tside its desig n limits . Component failure m ay
result if an e ngine is subject to such conditions as
ove rboosting or ovcrspeeding, or if excessive or
inadequate opera ting tem peratures and pressures are
allowed. A deficient kno wledge of engine han dling
procedures can a lso gene rate problem s with
car burettor icin g, m ixture leaning, e tc., which in
turn can lead to loss of power.
• Fuel mismanage me nt. Fuel star vatio n (i.e . when
fuel is on board the a ircraft bu t is no t suppl ied to the
cngine/s) and fuel.exh au stion (i .e. when no fuel is
left in the system) a ri se as facto rs in over 50 per cent
of en gine failure accidents. The reason alm ost
witho ut exception is e ither im proper in-fl ig ht fuel
system m a nagemen t or incorrect pre-flight planning.
As far as LAMEs and m ainten an ce a re con cern ed , the
fo llowing th ree main problem areas can be identified :
• approved e ng ine ma inten a nce procedures are
som etimes not observed;
• o n occasion s there appears to be non-compliance
with a irwo rt hiness req ui remen ts regar din g
in spectio n , overhaul , repair, the replacemen t of
parts, and a dh erence to sched ules; and
• modification s and repairs a nd alterations are ma de
w ithout p roper evaluation and approval.
10 I Aviation Safety Diges t 121
The fi nal common cause of engin e fa ilu res is that of
fuel contamina tion, a subject wh ich was add ressed m ost
rece ntly in two articles in Aviation Safety D igest 117 .
Notwithstanding the generall y h igh standard of fuel
qualit y control in Austral ia, e ngine power-loss
associated with contami nated fuel - especially by water
- contin ues to occur .
Recommendations
The recommendation s for min imising the possibili ty of
engine power -loss accidents are listed u nder the broad
headings of gen eral en gine han dl ing, fuel system
m anagem ent, and mai n tenance . The first two group s
a re m ainly applicable to pilots a nd the latter to LAMEs,
althou gh obvio usly a degree of overlap will exist in
som e instances . Som e of the ad vice offered may seem
self-evident, bu t u nfortu nately the accident ra te and
relevant factors prove that it is not so for too many
op erators.
General engine h a ndling
Pilots m ust know al l lim itat io ns pertaining to their
aircraft 's power plan t a nd they m ust avo id operating
o ut side those li mi tations. T h is m eans that a thorough
knowled ge of all engine and associated systems
procedures, including emergency actions, must be
acquired and retained.
T he engine runup during the before takeoff checks
sho uld never be carried o u t until all temperatures and
i
I
•
T horou gh p re-Oight preparation will remove almost any
chance of fuel exhaustion . There must be sufficient
clean fuel of the correct grade on board the aircraft for
you to fly to yo ur destination, with stipulated reserves.
Several impo rtant poin ts to be noted here are:
• O nly the usable fuel should be included in flight plan
calc ulations.
• F uel contents m ust be checked visually by the pilotin -command - do no t rely solely on the gauges or
someone else's memory.
• If you are using a partial fuel load, check the exact
con tents by som e precise method, e.g. dipping with a
properly calibrated stick . A visual check is only
accurate for FULL tanks .
• Complete trust in fuel gauges has often resulted m
fuel exhaustion short of the destination.
• I t is most importan t to remember that, whi le
refue ll ers have responsibilities with regard to fuel
type and q uali ty, ultimately it is the pilot-incommand's responsibility to verify fuel quali ty,
quantity and type, and to check for water content.
Thorough p1·e-fl igh t preparation refers not only to
plan ning but also to the daily or pre-flight inspection .
In addit ion to confirming fuel contents this inspection
must include a careful fuel drain check of all sumps
before the first fligh t of the day and after each
refuelli ng, and a check that a ll fuel tank ven t openings
are unobstructed. Fuel type and grade (e. g . AVGAS not
AVTUR or vice versa) must be confirmed . Tank caps
must be sec u re and fuel drains closed.
A surpr ising nu m ber of engine failure accidents are
cau sed by fuel starvation resulting from incorrect
operation of fuel selector valves. If you are not totally
fam iliar with the various valve positions in your aircraft
and any in-flight restr ictions which might apply to some
positions, then refresh yourself t horoughly before flight.
The same can be said for the a uxiliary fuel pump (if
fit ted): when and how to use these pumps can differ
markedly between aircraft types, even if they have a
similar engine; and m isuse of the pump can lead to a
loss of power.
After the engine has been started fuel flo w from each
tank to the engine/s should be checked. Sufficient time
must be allowed to be certain that a newly selected tan k
is in fact feeding, as residual fuel in the lines, and the
carburettor from the previously selected tank will keep
the engine running for some seconds. Hand-operated
primers must be verified 'off' and locked.
Before changing fuel tanks in the air, confirm the
fuel quantity in the tank to be selected and ensure that
the position to which you are going lo move the valve is
correct. Monitor the fuel pressure after you have
changed tanks until you are certain that there is
satisfactory fuel flow .
Mainten an ce
All servicings and inspections must be carried out in
accordance with approved schedules. Unauthorised
changes or modifications to engines must not be
effected : they invite disaster.
In add ition to normal engine servicing, maintenance
should include inspection of fuel cells and tanks for such
things as signs of collapse, contamination, vent
obstruction, internal damage, security, leaks and
general condition . The fuel filter should be checked
periodically for condition and/or contamination . A
check of the operation and security of the fuel system
selectors and control levers should be made, wh ile the
accuracy and condition of the components of the fuel
contents indicating system should be confirmed.
One item of an aircraft's propulsion system which is
sometimes neglected is the propeller. All blade nicks,
dents, scratches, etc., must be dressed out in
accordance with the manufacturer's recommended
procedures to prevent fatigue cracks which could cause
propeller blade failure, resulting in the loss of a section
of the blade . Imbalance forces cou ld create a
catastrophic situation if a sizeable portion of the blade
were lost. At the least, this would necessitate a prompt
RPM reduction to minim ise vib rat ion . This would mean
engine power could not be converted into much more
than idle thrust.
The dressing of propeller blades must be carried out
only by a LAME.
Conclusion
A loss of engine power in fl ight is one of the most
serious emergencies a pilot can face. There are about
45 accidents annually in Australia in which power-loss
is a relevant factor. It must be stressed, however, that
relatively few of these failures can be attributed solely to
mechanical malfunction : modern aircraft engines are
generally extremely reliable. The main weak li nk in the
system is the human.
By adhering to the procedures detailed in this article ,
pilots and LAMEs should be able to eliminate some of
the factors that have in the past led to needless engine
power-loss accidents •
Aviation Safety Digest 121 I 11
�Supervision and self-discipline
Supervis io n and self-discipline are integral components
of Oyin g operations. To a fair extent they are
interrelated: as a pilot or LAME develops increased selfdiscipline, less supervision is usually required .
S upervision itself can be a difficult skill to develop
a nd exerci se. Some aspects , such as monito rin g a
subordinate's performance, may be relatively
strai ghtforward through the application of established
tenets of managem ent. On the other hand a superv isor
m ay need to u se acquired or intuitive understanding of
su ch complex variables as human nature in deciding
how mu ch supervision an individual requires, and
whether or not that supervision is likely to stifle
ini tia tive rather than contribute to safe a nd effective
o peratio ns.
I t is not the A viation Safety Digest's role to teach
o pera tions manager s and chief pilots and engineers how
to become good supervisors; that is an indiv idual or
company respons ibility. However, it is right that the
Digest should draw attention to occurrences in wh ich it
is clear that deficient supervision was a factor in
prejudicing air safety. N umerous exam ples are
available:
• An instructor sent a studen t p ilot on a peri od o f solo
circuits in condition s conducive to carburettor icing.
The pre-flight briefing d id not include specific ad vice
on the use of carburettor heat. On downwind during
the first circuit the engine lost power : this was later
a ttributed to carburettor icing.
• A pilot was authorised for his first solo cross-country
navex d espite forecast weather condition s that were
clearl y unsuitable. He encountered thunderstorm s,
low cloud and h eavy rain , and eventually becam e
lost. Emergency procedures were initiated b y a ir
traffi c control a nd , after some ver y ten se moments,
the a ircraft was located and gui ded to an airfield
wh ich was open to VMC traffic .
E ach of these examples is relativel y straightforward,
with the problem b eing primarily o ne of deficient
supervi sion . Often , however, the lines of responsibility
between su pervisors and indiv idual pilots can become
blurred : this will inevitably happen from time to time.
It is on such occasion s that the self-d iscipline which is
cru cial to a ll o f those associated with avia tio n b ecomes
so important. When that self-discipline is absent, the
pote ntial for acci dents is high , as the pilot of a Cessn a
210 discovered.
The accident
A young, inexperienced commer cial pilot had been
operating in a re mote area without supervision for some
time. H e was working with an oil exploratio n team a nd
whe n the contract was completed a party was held. On
the m orn ing a fter the party th e pilot got up at about
0400, having had only 3-4 hours rest.
Several fli ghts were completed, in the course of which
the pilot had to refuel his a ircraft twice, both tim es with
a h a nd pump in ver y h ot conditio n s.
By the tim e h e comm en ced a n approach into a
900-metre-lon g ALA a t about 1000 hours, he was
extremel y fat igu ed. While the ALA was satisfactory, in
12 I Aviation Safety Digest 121
Aircraft accident reports
FIRST QUARTER 1984
the prevailing conditions and at the Cessna's landing
weight , an accurately Oown approach was necessary.
Instead, the pilot failed to complete his pre-landing
checks and did not lower full Oa p , used too high an
approach speed for the aircra ft 's weight , a nd landed
with a strong tail wind. Although he recognised during
the final approach that his groundspeed was excessive,
he did not take any correcti ve action . To complete his
litany of woes he misjudged his landing speed and Oare.
Touchdown was m ade 300 m etres into the strip and the
aircraft bounced several times before settling properly
with only 200 metres to run. Heavy braking failed to
stop the aircraft , which overturned and sustained
substantial damage after it ran off the ALA.
Th e following information has been extracted from accident data files maintained by the Bureau of Air Safety Investigation.
The int ent of publishing these reports is to make available information on Australian aircraft accidents from which the reader
can gain an awareness of the circumstances and conditions which led to the occurrence.
At the time of pub lication many of the accidents are still under investigation and the information contained in those
reports must be considered as preliminary in nature and possibly subject to amendment when the investigation is finalised .
Readers shou ld note that the information is provided to promote aviation safety - in no case is it intended to imply blame
or liability.
Note 1:
All dates and times are local
Note 2:
Injury classification abbreviations
C = Crew
P = Passengers
0 =Others
N = Nil
F =Fatal
S =Serious
M =Minor
e.g. C1S, P2M means 1 crew member received serious injury and 2 passengers received minor injuries.
PRELIMINARY REPORTS (The follow ing accidents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
18 Jan
Robinson R22 VH-C IA
Non-commercial-aerial application/survey
C2N
1500
Albany Whaling Sin , WA
Albany Whaling Sin, WA/Albany, WA
8451002
Fo llowing a partial loss of engine power, the pilot attempted to carry out a landing on a downhill slope with a 15·knot tailwind.
During the landing run the helicopter began to roll over. The pilot was un successful in his attempt to prevent the rollover.
18 Jan
Beech 95-C55 VH·ATB
Non-commercia l-pleasure
C1N, P1N
0730
Surfers Garden s, Old
Surfers Gardens, Old/Warwick, Old
8411002
The pilot abando ned his trip due to th e wet and boggy conditions of the grass strip. While taxiing to the parking area he tried to
avoi d a large puddle adjacent to parked aircraft. Realising that he had misjudged his wingtip clearance from a parked aircraft , the
pilot braked but could not prevent his wingtip st ri king the engine cowl of a Cessna.
In addition to the p ilot's fatigued state , several other
significant factors emerged. First, it became a pparent
that , during his len gth y period o f unsupervised
operations, this young pilot 's skill level had deteriorated
to the extent that it was n o lo nger adequate for the
tasks h e was exp ected to complete. Subsequent flight
testing showed that his general flyin g skills were below
the standard required for comme rcial operations: a
short session of retra inin g was n ecessary before the
satisfactory standard was regained. It does not seem
unreasonable to question the wisd o m o f the operations
manager/senior pilot who sen t thi s inexperienced p ilot
off by himself for a protracted period of commercial
operations without taking positive action to en sure that
the pi lot did not neglect the need to remai n proficient
in a ll relevant fl yin g and operational procedures.
As a second point , it transpired that the pilot was in
a hurry to complete his fl y in g on the day of the
accident as he was scheduled for a period o f leave. In
his own word s, he was looking forwa rd to the break and
' just wanted to get this fin al job done and get out' .
T hus, he was intent o n landing a nd at no stage even
cons idered a go-around for another circuit.
Comment
Regardl ess o f n a tural fl ying s kill a nd technical
kno wledge, an y indi vidual who does not h ave a highly
developed level of self-disciplin e is not a good p ilot.
S upervisors share with those who wo rk for th em the
respon sibility for d eveloping th at d iscipline e
20 Jan
Rockwell 685 VH-MML
Charter-cargo ope rations
C1 F
0834
Ben Lamond , NSW 4NW
Armidale, NSW/Glen Innes, NSW
8421004
During the flight the pilot reported that he would descend to cruise at 500 ft agl. Witnesses saw an aircraft at low level on the ex·
peeled track and others heard a ircraft noise and then the sound of an impact. Weather conditi ons were overcast with low c loud
covering the hills. The wreckage was fo und on the northern s ide of an east-west-oriented ridge line. Impact had occ urred while
the aircraft was tracking to the north.
21 Jan
Piper 28-235 VH-IMT
Non-commercial-aerial application/survey
C2N
1130
Mundabu llangana
Mundabu Ilangana/M u ndabullangana
8451004
The aircraft had been parked in a hangar and not flown until the day before the accident. After landing on that occasion, the pilot
noticed that the airspeed indication was s low to return to read zero. The next day the pil ot believed the airspeed took longer than
usual to reach the normal cruise indi cation. When on final , with an indicated airspeed of 80 knots, the stall warn in g light
illuminated, the aircraft stalled and st ruck the ground.
•
29 Jan
Beech V35 VH-CFH
Non-commercial-pleasure
C1 N, P3N
1212
Corowa, NSW
Corowa, NSW/Corowa, NSW
8421005
During the takeoff the left wing dropped sudden ly and the aircraft began to drift left. The pilot abandoned the takeoff and commenced braking but the ai rcraft veered further left into long grass beyond the strip boundary. A fire s tarted in the grass under the
left wing; however, it was extinguished before the aircraft caught fire.
29 Jan
Pitts S1 VH-IGZ
Non -commercial-pleasure
C1 N
0950
Darwin River Dam, NT
Darwin, NT/Batchelor, NT
8441002
During cruise at 1500 ft the fuel pressure dropped and the engine lost power. Attempts to res to re fuel pressure failed and the pilot
elected to land on the edge of a dam. During the landing roll, the aircraft nosed over and came to rest after sliding inverted for
about 10 metres.
Piper 31 VH-KFD
Test
C1 N, P1 M
1137
Moorabbin, Vic 6SSE
Moorabbin , Vic/Moorabbin, Vic
8431002
Fol lowi ng routine replacement of th e right engine, a pilot experienced a drop in CHT and EGT on th e right engine at 4000 ft in the
cruise. Complete power loss followed and the propel ler was feathered . A similar failure occurred o n the nex t flight despite a prior
ground check and air test. Further ground tests were completed, includ ing replacemen t of the fuel cont ro l unit. On the next air
test the problem recurred. The left engine then fa iled and damage was sustained on landing In a paddock.
03 Feb
04 Feb
Schneider ES60 VH·GQH
Non-co mmercial-pleasure
C1S
1450
Latrobe Valley, Vi c 2NE
Lat robe Val ley, Vi c/Latrobe Valley, Vic
8431003
After release from an aerotow launch at 2000 ft, the pil ot detected s ignificant s ink. Attempts to find lift were un s uccessf ul and,
judgi ng he would be unable to return to the s tri p, the pi lot elected to make an o ut landing. The aircraft collided with a tree during
the approac h into th e se lected area and s ubsequently s truck the grou nd heavily. Witnesses reported that th e airbrakes were
extended fro m the time of release from the aerotow.
Aviation Safety Digest 121 Ii
�PRELIMINARY REPORTS (The fo ll ow ing acc idents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
PR ELIMINARY REPORTS (Th e follow ing acc idents are st ill under invest igat ion)
Injuries
Record number
Date
Time
05 Feb
Hi ller UH12-E VH-XRG
Aerial agriculture
C1N
0900
Beaudesert, Qld 8SE
Aroona Stn, Qld/Aroona Stn, Qld
8411003
At the end of a 180-deg turn the pilot attempted to level out but there was no cycl ic response. The helicopter continued in the turn
and t he application of back cyclic could not prevent the nose dropping. The helicopter st ruck the bank of a c reek, shearing off the
tailboom, main rotor and gearbox, and came to rest in the water. The pilot escaped unhurt and unaided f rom the partially
submerged cockpit.
Aircra ft t yp e & registration
Location
Kind of flyin g
Departure point/Destination
Injuries
Record number
02 Mar
Cessna A1 88B-A1 VH-SHK Aerial agricult ure
C1N
1000
Boggabri, NSW 20N
Merriendi, NSW/M erriend i, NSW
8421 009
Jus t after takeoff for sp ray ing operatio ns th e aircraft san k back to the g round and drifted to the left. The pil ot dumped the load
but the aircraft became en tangled in a fence r unn ing alon g the left side of the strip.
05 Feb
Burkhart ASTIR-CS VH·G DS Non-commercial-pleasure
C1 N
1305
Maryvale, Qld 7E
Boonah, Qld/Dalby, Qld
8411004
The pilot elected to do an out landing and selected a paddock which had a power line runn ing east-west on its sou thern side. An
approach was made into the paddock on a westerly heading but the glider struck another power line running at a right angle to the
one noticed by the pilot.
03 Mar
Brit nor BN2-A21 VH -NTC
Charter-passenger operat ions
C1N, P5N
1425
Darwin, NT 200N E
Cape Don , NT/Sm ith Po in t, NT
8441006
The intended destination had been rendered unsuitable due to recent ra in. A nearby disused strip was inspected and the pilot was
ad vi sed t hat it was se rvi ceable. After the inspect ion abou t 38 mm of rain fell and water abo ut 20 cm deep lay on a section o f the
st rip when the pilot landed. As the main wheels entered the water, the nosewh eel was pul led into hard cont act w ith the strip and
collapsed rearwards.
08 Feb
Piper 28-140 VH-CNS
Instructional - solo (supervised)
C1 N
0810
Cessnock, NSW
Cessnock, NSW/Cessnock, NSW
8421006
Having completed his first solo the previous day, the pilot was given a dual check and autho rised to carry o ut f ive solo circuits.
The first landing was reported as normal; however, on the second, the pilot carried ou t a go-around after the aircraft bounced to
about 30 ft. After a slight bounce on the next landing, a go-around was carried out and the aircraft adopted a noseup att itude and
turned left. The left wing st ruck a fence before the aircraft was landed in a field .
03 Mar
Mooney M20F VH-ERS
Non-commercial-pleas ure
C1N, P1 N
0830
Red cliffe, Qld
Redcliffe, Qld/Redcl iffe, Qld
841 1009
The pi lot reported that prior to touchdown all gear down indicat ion s were normal. Short ly after touchdown, t he ri ght gear co llapsed and the airc raft came to res t on the right w ingtip 6 metres from the edge o f the runway.
08 Feb
Cessna A 188B·A 1 VH-WJ R Aerial agriculture
C1 N
11 30
Icy Creek, Vic
Nar Nar Goon, Vic/Nar Nar Goon, Vic
8431005
The pilot intended to spray several crops in the same general area and noted that the first crop had powe r line obstructions. The
spraying of this crop was completed, except for clean-up ru ns, and the pilot returned to carry out these runs after t reating t he
other crops . On the first run the pilot saw the power line but was unable to prevent t he aircraft coll iding wit h it. The aircraft re·
mained controllable and the pilot made a normal landing at the destination strip.
09 Mar
Cessna T188C VH-MXJ
Ae rial ag ricult ure
C1 N
0641
Ayre, Qld 8WNW
Hoey's Strip, Qld/Hoey's Stri p, Qld
8411010
Short ly after takeoff for rice sprayi ng operatio ns th e pilot no ti ced th at eng ine power was decreasing. He was unable to prevent a
continuing .loss of power and after dumpi ng t he hopper load he attem pted to guide the aircraft towards a relat ive ly c lear area. One
gear whee l entered t he rice crop and the aircraft swun g into an adjacent cane crop and overt urned .
09 Feb
Amer Air SB VH-WXH
Non-commercial - pleasure
C1S
1545
Falconhurst, WA
Jandakot, WA/Quairading, WA
8451005
After a severe vibration developed, the pilot advised that he was diverting to a nearby airstrip. The vibrat ion worsened and the
pilot attempted a landing on rocky terrain. The aircraft overturned during the land ing.
10 Mar
Bryan HP-18 VH-GJZ
Test
C1 F
1618
Kingaroy , Qld
Kingaroy , Qld/Ki ngaroy, Qld
841101 2
The aircraft was undergoing its second test f light sin ce construc t ion had been comp leted. A fter t he test sequence had been completed satisfacto rily, t he pilot posit io ned t he aircraft for land ing . When the glider was about 150 ft agl, the pilot reported by rad io
" something bro ke" . The ai rcraft was observed to ent er a steep s piral descent wh ich cont inued until gro und impact. Init ial
investigation revealed that an asymmet ric flap con dit ion exi sted at the time of impact.
14 Feb
Cessna 182L VH-UCX
Charter-passenger operations
C1N
0930
Borroloola, NT
Borroloola, NT/Robinson River Sin, NT
8441003
The aircraft had been parked for some days and had been subjected to numerous rain showers. A substant ial amoun t of water
was drained from the fuel system during the pre-fligh t inspection. Shortly after takeoff, t he engine lost power and t he pilot began
to manoeuvre the aircraft for a forced landing. He was able to obtain partial powe r for a brief period fol lowing whi ch the engine
failed completely and the pilot was committed to a landing on soft wet ground.
11 Mar
Hiller UH1 2-E VH-FBQ
Aerial agr icu ltu re
C1 N
1345
Casino, NSW 15S
Belara Station, NSW/Belara Stat ion, NSW
8421 010
The helico pter was c limbing th rou gh a height of abo ut 30 ft when the pilot heard a loud snapping noise. Th is was fol lowed by temporary loss of cont ro l and severe vibrat ion. The pilot retai ned sufficient control of the aircraft to carry out a forced landing at
abo ut 10-knot ground s peed.
18 Feb
Cessna 150M VH-BFA
Ferry
C1 F
1651
Parafield, SA 2NE
Griffith, NSW/Parafield, SA
8441004
The pilot departed Toowoomba early on the same day to ferry the aircraft via refuelling stops at Walgett and Griffit h. The fl ight
evidently proceeded normally until the aircraft was on approach to land at Parafield. At this t ime, the pi lot advised t hat the engi ne
was failing and shortly afterwards he reported that he was experiencing fuel prob lems and wou ld attempt a forced land ing. Control of the aircraft was subsequently lost and it crashed inverted into a suburban property.
20 Feb
Cessna Citation 500 VH-FSA Charter-cargo operations
C2F
2018
Proserpine, Qld 4SE
Townsvi lle, Qld/Proserpine, Qld
8411 007
After descent clearance, the aircraft reported at 2600 ft. Follow ing a frequency change, a fu rth er descent was adv ised and no
other cal ls were received from the aircraft. Witnesses reported a heavy rain squall in the area abo ut this time and one witness saw
the aircraft with navigation and strobe lights on some 8 km from the aerodrome on approach to runway 11. This wi t ness then saw
a bright red flash and fireball further east. T he aircraft crashed while in a shallow descent with wings level and gear and flap
ex tended about 5 km from the runway.
21 Feb
Piper 32-300 VH-MVT
Non-commercial-pleasure
C1 M, P2S, P1 M, P1N
2005
Aldinga, SA
Aldinga, SA/Aldinga, SA
8441005
After returning from a flight in the local training area, the pi lot went around from an approach which was too high . On the second
approach, touchdown occurred about half-way along the 820 m strip. The aircraft started to s kid under heavy braki ng and the pilot
considered that the aircraft might overrun the strip into a gully. Power was applied and, althoug h the airc raft became ai rborne at
the strip end , it then descended and col lided with the far bank of the gully.
22 Feb
Piper 36;.375 VH-ALQ
Aerial agricult ure
C1 N
1525
Griffith, NSW 68SW
Griffith , NSW 68SW/Griffith, NSW 68SW
8421008
During takeoff, with a full load , the aircraft became airborne as expected but then sank back onto t he ground. The pilot initi ated
dumping of the load while continuing the takeoff. A large fence post was struck by the right wheel, detaching the strut from the
aircraft and causing the ai lerons to jam temporarily. The aircraft was flown to the operator's base and a f lap less land ing made on
a grass strip.
26 Feb
Beech V35 VH-CFK
Non-commercial - practice
C1N, P1N
1600
Gayndah, Qld 19NW
Binjour, Qld/Binjour, Qld
8411008
The pilot had not flown for some time and was practising circuits with her husband who was also a pilot. On downwind , her preland ing checks were int errupted by a radio call. The aircraft was subsequently landed with the gear ret racted. The gear warn ing
horn was not serviceable prior to the flight.
28 Feb
Cessna 1828 VH-RFG
Non-commercial-business
C1 N, P2N
1230
Goober Pedy, SA
Cowel l, SA/Goober Pedy, SA
8441007
The pilot reported that the aircraft was higher than normal during th e approac h to land in crossw ind condition s. The airc raft
touched down heavi ly and bounced. Control was not regained and the aircraft stalled at about 10 feet above t he runway. It t hen
.struc k the ground in a nosedown attitude, sustaining damage t o the forward fuse lage and t he propeller.
ii I Aviati on Safety Digest 121
12 Mar
Cessna 172N VH-IVO
Non-commerc ial - pleasure
C1N, P3N
2004
Aeropelican , NSW
Port Macquarie, NSW/Aeropelican, NSW
8421011
Fol lowing an approac h flown at 70-75 knots, the ai rcraft touch ed down about hal f-way along the runway and bo unced a number of
times. Near the runway end the pilot initiated a go-around but t he aircraft failed to c limb and col lided with the airport boundary
fence before coming to rest in t he m iddle of a hig hway.
12 Mar
Cessna U206G VH-FRT
Charter- passenger operat ions
C1 N, PSN
0909
Wilpena, SA
Wil pena, SA/W ilpena, SA
8441008
Duri ng t he landing flare the airc raf t ballooned and assumed a nose-hig h attit ude. The pilot attempted to take corrective action but
the tail contacted the grou nd before t he mainwhee ls. The aircraft bounced and on subsequent touchdown the tail again st ruck
the gro und.
..
13 Mar
Cessna 182Q VH-EIL
Ferry
C1N
0845
Taggerty, Vic 5SSW
Eildon, Vic/Taggerty, Vic
8431006
The pilot carried out a straight-in approach to t he 760-metre-long grass st rip. Rai n was fallin g at the time. The airc raft touched
down about 200 metres beyon d t he threshold and the pilot reported that the brakes seemed ineffect ive. After overru nning t he
strip, the aircraft ove rturned wh en it en tered a ditch.
14 Mar
Cessna A1 88A VH-KZE
Aerial agricult ure
C1 N
0930
Condamine, Qld SW
Dalby, Qld 124NW/Dalby, Ql d 124NW
8411 014
The pilot was conducting the last run of a spraying operation . Because of the w ind condi t ions, the aircraft was displaced over the
boundary fence line to achieve t he des ired spray coverage. The pilot was distrac ted by a rad io call and the right mai nwhee l st ruck
a fence post. Alt houg h the gear leg was torn off, the pilot retained cont rol of the aircraf t and su bsequent ly carried o ut a successful emergency landing at his normal base of operations.
14 Mar
Mooney M20-J VH-M IY
Non-commercial -pleasu re
C1 M
0945
Great Ke pp le Is
Great Kepple l s/Rosewood Island , Qld
8411 013
Short ly after takeoff, the pi lot heard a loud no ise an d noticed that the lugg age locker door was o pen. A 180-degree t urn was carried out fo r an approac h to the depart ure runway . As the aircraft approached the end of the runway the r ight wing struc k the
grou nd and the aircraft sl id s ideways along the runway. All the landing gear legs collapsed befo re t he aircraft came to rest.
15 Mar
Cessna 182-D/A 1 VH-DZL
Ferry
C1N, P1N
1300
Northam, WA
Toodyay, WA/Northam, WA
8451006
The model spec ifi cati on for th is aircraft indicates that it has been converted \o tailwheel co nf igurati on. The pilot repo rted that the
w ind sock was indicatin g a wind of 270 degrees, 10 to 13 knots . He elected to land on ru nway 13 and after a three-point touchdown
the aircraft began to t urn righ t. The pilot was unable to regain direct io nal control an d t he aircraft ground looped, bend ing the left
w ing and tailplane.
Aviatio n Safety Digest 12 1 I iii
�PRELIMINARY REPORTS (The fol lowi ng accidents are sti ll under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
fniuries
Record number
PRELIMINARY REPORTS (The fol lowing accidents are st il l under investigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
lniuries
Record number
18 Mar
Cessna 182K VH-KRH
Sport parachuting (not associated with airshow) C1 N, P2N
1445
Mt Alaric, NT
Batchelor, NT/Batchelor, NT
8441009
Whilst airborne for parachuting-dropping operations, the pilot noted that the weather at his destinat ion had deteriorated. He
elected to divert to a clear area and carry out a precautionary landing. The area se lected was soft and during t he landing roll the
nosegear strut collapsed.
29 Mar
Be ll 206-L 1 VH-BJ X
Construction work
C1S
1107
Leigh Creek 85SSE
Oraparinna HS, SA/South Mount Hayward, SA 844101 1
As part of a communicat ions propagation test, personnel were to be posit ioned in the Oraparinna Nat iona l Park by, helicopter.
One person was being lowered by w inch when , at about 3 metres below the hel icop ter and 4 metres above the ground, his harness
became detached from t he winch hook and he fell to t he ground.
19 Mar
Piper 28-140 VH-MGG
Instructional-solo (supervised)
C1N
1050
Murray Bridge, SA
Murray Bridge, SA/Murray Bridge, SA
8441010
After a number of dual circuits, the pilot was authorised to carry out solo circui ts with touch-and-go land ings. After t he first
touchdown the pilot applied full power, then selected the flap to 10 degrees. The airc raft entered a rapid turn to the left and the
pilot abandoned the takeoff. The aircraft slid sideways off the strip and the nosewheel was bro ken off.
30 Mar
Hiller UH12-E VH-FBZ
Activ it ies associated with aerial agricu lture C1N, P1 N
1030
Muttabu rra 52NE
Elabe Station, Old/Potosi Station, Old
841 1017
The pilot in command was occ upy ing the rear control posit ion, wh ich did not have tail rotor control pedals, wh ile another pilot
f lew the aircraft. Duri ng the approach to land, the pilot in command became concerned when the airspeed decayed and he
pushed the cyc lic con t ro l forward to ini tiate a go-around. The aircraft yawed to t he right, cont rol was lost and t he ai rcraft struck
t he ground heavily, coming to rest on its right side.
22 Mar
Beech 35-C33 VH-CEA
Non-commercial-pleasure
C1N, P3N
2019
Essendon, Vic
Moorabbin, Vic/Essendon , Vic
8431007
On the downwind leg of the circuit, the pilot selected the landing gear down and observed the gear down light illuminate. Du ring
the landing roll, the left wing began to lower and the left aileron and flap contacted the ground. The airc raft veered off t he runway
before coming to rest. The left main gear leg was found to be stil l in the up posit ion.
23 Mar
Cessna U206E VH-TSR
Charter- passenger operat ions
C1 N, P3N
1538
Bathurst Harbour, Tas
Cox Bigh t, Tas/Bathurst Harbour, Tas
8431008
After overflying the strip, the pilot noticed the wind was about 030/15-18 knots and fluctuating about 30 degrees eit her side of the
mean direction. He elected to land to the southeast on strip 12. On landing he did not begin braking immediately and let the ai rcraft roll while raising the flaps. He then braked intermittently and finally applied heavy braking as he neared the end of t he st rip.
The aircraft overran the strip and subsequently overturned.
24 Mar
Piper 28-R201 VH-FSD
Non-commercial-pleasure
C1 N
1930
Dubbo, NSW 102SW
Moree, NSW/Griffith, NSW
8421015
While cruising at 6000 feet on a night VMC flight the pilot encountered a heavy rain shower. Duri ng an attempted 180-degree turn
the aircraft entered a spiral dive and in the recovery from this dive the aircraft was eviden tly overstressed. After divert ing to
Parkes the pi lot flew to his planned destination on the following day. The damage sustai ned by the wings was not detected un ti l a
subsequent daily inspection.
24 Mar
De-Hav Sea Fury-308 VHHFG
Ferry
C1 N
0957
Leyburn , Old 12S
Toowoomba, Old/Scone, NSW
841 1015
The pilot had limited experience on type. After establishing the aircraft in level fl ig ht following a climb to flight level 130, t he pilot
noted that the o il temperature was rising. To prevent engi ne damage he elected to make a wheels-u p landing in a paddock. Postaccident inspection revealed that the oi l cooler shutters were closed. These shutters should have been in the open position.
24 Mar
Cessna 172N VH -RWO
Non-commerical - pleasure
C1N , P3N
1000
Rottnest Is, WA
Jandakot, WA/Rottnest Is, WA
8451007
The pilot was landing into the east with a 10· to 12-knot southerly wind. On short final approach at a speed of 60 knots the aircraft
encountered sink. Touchdown was heavy and resulted in damage to the propeller, nosegear and engine f irewal l.
24 Mar
Cessna 150G VH-KUB
Non-commercial - pleasure
C1 N
0930
Stud Park Sin, NSW
Stud Park Stn, NSW/Stud Park Sin , NSW
8421013
At about 300 feet after takeoff the pilot noticed a restriction in forward movement of the co ntrol yoke. He carried out a landing in a
paddock to his left but the aircraft struck a levee bank and overturned.
24 Mar
Bell 47-G4 VH-UTO
Activities associated with aerial agricu ltu re
C1S
1425
Werris Creek 23W
Burwood, NSW/Burwood, NSW
8421014
The pilot was inspecting areas of noxious weeds to check on the results of recent spray ing. The helicopter struck a power line
which severed the bubble windscreen. The wire then contacted the pilot 's throat befo re bei ng cut by the main rotor. The
helicopter st ru ck the ground tail rot or first about 35 metres beyond the point of collision. After extricating himself f rom the
wreckage, the pilot swam across a river, walked 3 km to a homestead and drove 15 km for help. He was later admitted to intensive
care in hospital.
28 Mar
De Hav 82-A VH-AT J
Non-commercial-practice
C1 N
1635
Berwick', Vi c
Berwi ck, Vic/Berwick, Vic
8431010
The pilot was conducting a series of touch-and-go landings. The area being used was to one side of the gravel runway in order to
avoid risk of gravel damage to the aircraft fabric coveri ng. As power was being applied for the fourth takeoff, the main gear
became caught in an area of long grass, the nose pitched down rapidly and the aircraft overtu rned.
28 Mar
Cessna 172G VH -DJE
Aerial mapping/photography/survey
C1M, P1 M
0945
Cann River, Vic
Bairnsdale, Vic/Noorinbee, Vic
8431011
On arrival at his destination, the pilot made a low inspection pass over the strip at about 20 feet agl in a f lapless configu ration at
80-90 knots. As he neared the end of the strip he pulled up steeply to about 150-200 feet. At the top of the cl imb the aircraft banked to the left, descended rapidly while turning through some 135 degrees and struck the ground in a left wi ng down attitude.
29 Mar
Piper 30 VH-TON
Non-commercial -business
C1N
1755
Kalumburu, WA
Kununurra, WA/Kalumburu, WA
8451008
The landing gear had been selected down during descent to the destinat io n. On arrival overhead th e strip the pilot noticed some
cattle on the strip . He became concern ed with the onset of darkness and se lected the gear up to make a quick pass to clear the
cattl e from the strip. The gear was selected down on downwind and the selec tio n was again checked on f inal approach but th e air.craft landed without the gear being down and locked.
iv I Aviation Safety Digest 121
FINAL REPORTS (The investigation of the following accidents has been completed)
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours To tal
Hours on Type Rating
lniuries
Record
number
Non-commercial -pleasure
06 Jan
Cessna 172N VH-WSL
C1N
Moorabbin, Vic
Moorabbin, Vic/Moorabb in, Vic
0938
8431001
Private
42
81
4
None
restricted
As the airc raft was tax iing for a runway 35 departure, there was a westerly wind change. As runway 31 was temporarily unavai lable
t he pilot elected to take off on runway 35. During the ensu ing circu it, he was adv ised of a crosswind and poss ible downwind component. After to uchdown the prope ller and left w ing contacted t he runway when the pi lot lost contro l of the aircraft during the
landing roll.
15 Jan
Burkhart Tw in Ast ir VH-IUF
Instruct ional-solo (supervised)
C1 N
1245
Gawler, SA
Gaw ler, SA/Gawler, SA
8441001
Glider
22
15
15
None
The normal final approach was f lown but just after t he aircraft was flared ii dropped to t he runway, bounced once, then contacted
the runway heavil y.
The in experienced student was f lying a solo circu it after a dual check when he misjudged the landing flare.
05 Feb
Piper 32-300 VH-TL T
Non-commerc ial- practice
C1 N, P2N
1612
Moorabbin, Vic
Moorabbin, Vic/Moorabbin , Vic
8431004
Private
36
214
23
None
A fter takeoff, the pilot noticed t hat the engine cow l had lifted slightly. He decided to comp lete the c ircu i t and land. During t he
c rosswind leg of the circuit, the cowl li ft ed comp letely from the left attachment points and obscured, to a large extent, the pilot's
fo rward vision. An approach was t hen made to a cross-strip and on short f inal the pilot lost s ight o f the runway and t he aircraft
landed heavil y.
The top engi ne cow l had not been correctly secured before flight. Inspection of the aircraft revealed that the lug holes that
accept the cow l locating pins were not fitted with the required nylon inserts. It was poss ible for the cowl side latches to appear to
be fastened when in fact they were not properly engaged.
09 Feb
Cessna A188B-A1 VH-SHK
Aerial agriculture
C1N
1200
Boggabi lla, NSW
Boggabi lla, NSW/Boggabilla, NSW
8421007
Commercial
34
4350
3000
Ag ri cultural c lass 1
Shortly after becom ing airborne the performance of the aircraft began to deteriorate. The pi lot d umped t he load but t he aircraft
failed to c limb normally . The pilo t abandoned the takeoff and the aircraft touched down on t he strip, ran through t he boundary
fence and sustained damage to the tai l assembly.
No fault was subsequent ly found with the eng ine and associated systems. The takeoff had been attem pt ed in gusty wind con ditions and with a tailwi nd component. It was probable that t he ai rcraft had encountered windshear immediat ely after liftoff .
13 Feb
1310
Commercial
Cessna 402B VH-UBZ
Yam Island, Old
Charter-passenger operat ions
C1 N, P1N
Warraber Island , Old/Yam Island, Old
8411006
855
413
Instrument ratin g 1st class
22
or c lass 1
The airc raft to uched down normally on t he 760-met re-long stri p and t he pilot commenced braking immediately. He was t hen
distracted by the sudden appearance of two cyc lists at the edge of the strip and was concerned that they might attempt to cross
the strip in front of the ai rcraft. Thi s did not occu r and the pilot, ret urning his attention to the landing roll, real ised th at the rate of
deceleration was less t han expected. Despite pu mping the brakes, he was unable to prevent t he ai rcraft from overrunning the end
of the stri p and coll iding with a large rock.
Heavy rain had fallen on the st rip shortly before the aircraft arrived. The grass surface was slippery and resu lted in reduced
brak ing effecti veness. When the pi lo t realised that the rate of deceleration was abnormal, there was insufficient strip length
remaining to ens ure a successfu l go-around .
Aviation Sa fety Digest 121 I v
�FINAL REPORTS (The invest igat ion of t he foll ow ing accidents has been completed)
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Recor d
number
14 Feb
Partenavia P68-B VH-UUG
Non-commerc ial - business
C1 N, P2N
0630
Chum Plains, Old
Charl evi lle, Old/Cowley Station, Old
841 1005
Private
38
600
300
None
The pilot had obtained a briefing on the strip at the intended desti nat ion and was aware that it was in good condi tion. On arrival a
normal circu it was flown and on short final approach t he pilot noticed bushes on the strip. He prepared to go around but before
this could be effected the nose and left main wheels struck anthills which were obscured by the bushes. The left gear leg was
detached and the aircraft ground-looped.
T he pilot made a navigation error and had made an approach to a di sused stri p 13 km from the intended dest ination. The strip
had appeared serviceable when viewed from circu it height , but the pilot had not checked the orientation of t he strip which was 20
degrees different from that at the intended destination.
09 Mar
1408
Commercial
Cess na 402 B
Kidston, Old
VH-CWG
Charter- passenge r operations
C1N, P3N
Townsville, Qld/Kidston, Old
8411011
5400
875
37
Instrument rat ing 1st class
or class 1
The pilot was familiar with the area and his last fl ight to the stri p had been fou r days prior to the accident. A circuit was made in
light rain and on downwind the pilot thought the runway looked longer and di fferent in co lour. On flareout for landing the pi lot
noticed some cone markers on the left of his landing path. The nosewheel co llapsed on the landing roll.
The pilot had landed on a newly ploughed area to the r ight of the strip. The area gave the illusion of bei ng a prepared land ing
area when seen from the air. Although he thought the strip looked di fferent as compared to his previous land ing, t he pilot did not
attempt to find the reason for th i s difference.
20 Mar
Beech E55 VH-TT L
Non-commercial -pleasure
C1N, P4N
1000
Tocumwal, NSW
Tocumwal , NSW/Tocumwal, NSW
8421012 .
Commercial
40
1230
409
Flight instru.ctor grade 3
During the course of the flight, the pilot learned that the passenger in the right-hand front seat held an American pi lot licence and
was exper ienced on the type. He allowed the passenger to manipu late the controls unti l t he airc raft was on final approach and
al lowed him to keep his hands lightly on the controls during the flare and touchdown. During the landing ro ll the passenger, un·
noticed by the pilot, inadvertently selected the landing gear up. The aircraft slid to a halt with the gear partially retracted .
27 Mar
Piper 23-250 VH-IAC
Non-commercial -corporate/executive
C1N, P1 N
1922
Burketown, Old 3W
Mornington Is, Old/Karumba, Old
8411 016
Commercial
19
290
93
Inst rument rating class 4
Prior to departure for the planned 50-min ute flight, the pilot had added fuel to give an end urance of 100 m inutes. Adverse weather
was encountered enrou te and the pi lot became uncertain of his position. In fading daylight he recognised the Burketown area
and requested Fl ight Service to organise strip lighting. Before this could be arranged t he left engine failed and the pi lot
attempted to land on an old road. Touchdown occurred in a rough area adjacent to the road and the landing gear collapsed.
The left eng ine had failed from f uel exhaust ion . When ref uelling the aircraft, the pilot had not added sufficient fuel to allow for
60 minut es holding at the destination as required because of the forecast adverse weather.
FINAL UPDATES (The investigation of t he foll owing acc idents has been completed. The information is
add itional to th at previously printed in t he preli minary report)
Date
Pilot licence
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
20J an
8311004
Cessna172 N
Private
46
3064
2984
None
On the evening preceding the accide nt the pil ot ind icated his intention to commence mustering early the next morning. The pilot
arose at about 0530 hours and it is believed that the aircraft took off at about 0600. The aircraft was seen at about 0620 by the
stockmen. It was flying at about 100 ft agl and when the engine noise ceased, and the aircraft was not seen again, one stockman
rode to a nearby bore and found the inverted aircraft w reckage.
The aircraft had impacted the ground in a near-vertical attit ude. No cont ributo ry fau lt could be found with the aircraft or the
associated systems. The pilot did not hold a mustering approval and no evidence of him having undergone such training could be
found. It is probable that the aircraft stalled at low level and that the pi lot was unable to regain contro l before ground impact.
14 Feb
Airline transport
8321022
43
Cessna 180
12000
Instrument rati ng 1st c lass or class 1
and flight instructor
The pilots were engaged on the second of two period s of c ircuit and landing practice. Toward s the end of the twe lft h landing, the
aircraft ground looped to the left and the starboard wingtip and tailplane contacted the ground.
vi I Aviation Safety Digest 121
300
FINAL UPDATES (The investigation of the follow ing accidents has been completed. The inform ati on is
additional to that previously printed in t he preliminary report)
Date
Pilot licence
Record number
Age
Aircraft type
Hours total
Hours on type
21 Feb
Senior commercial
8341004
22
Col'laero LA4 200
1732
30
Rating
Instrument rating 1st c lass or class 1
and fl ight instructor
'
At 50 ft after takeoff the aircraft failed to contin ue to c limb, the airspeed decayed and the aircraft began to lose height. To avoid
trees ahead the pilot turned the aircraft. The right float struck the water, the aircraft yawed to t he right and skipped sideways to
the left across the water before coming to rest.
The takeoff d istance avai lable was less than the distance req uired in the prevailing condi tions. The takeoff was made w ith a 5to 10-knot headwind into th e south-east. The wind backed to a north-easterly above the tree line. This probably resulted in t he
foss of performance when the pilot turned the ai rcraf t to the right after takeoff.
25 Feb
8351006
Bell 47·G3B1
Commercial 31
1380
375
None
helicopter
Whi le establi shed in cruising flight the pilot felt something strike the airframe and noticed that a pillow supporting an external
. litter patient had been dis lodged. About one minute later the helicopter began to yaw to t he right with increasing speed. The pilot
entered auto-rotation, aiming for a run-on landing in a small c learing; however, as collective pitch was re-introduced control was
lost, the airc raft struck the ground heavi ly and was destroyed by f ire.
The pillow had struck the tail rotor and the tail rotor driveshaft subsequently fai led. The pilot had not received adequate trainin g in the actions to be taken following the loss of tail rotor con t ro l in flight and the f light manual instructions were not su ffic iently clear.
24 Mar
8351011
Cessna 150L
Private restricted
40
221
221
None
After locating some catt le for a mu stering party, t he pilot flew along a c reek line at about 400 ft ag l and 60 knots w it h 10 degrees
of flap. To keep the grou nd party in sig ht the pi lot commenced a left turn and the airc raft stalled . The pilot was unable to regain
control of the aircraft before it hit the ground.
The pi lot had received no t raining in low-level operat ions and had not adequately monitored the ai rspeed prior to commencing
the turn.
23 Apr
8331012
Beech .A36
Private
24
141
4
None
The pilot and his four passengers had planned a trip to Sydney and ret urn for the Aniac Day long weekend. In preparat ion for the
trip the pilot obtained a flight check in a Beech Bonanza ai rcraft.
On the morning of the acc ident the pilot obtained weather forecast s for the route to be flown, prepared a f light plan for the trip
and submitted it to t he Briefin g Officer at Moorabbin Airport at 0755 hours. The fl ight plan indicated that the ai rcraft would proceed to the first nominated report ing point at Mangalore outs ide Melbourne Contro lled Airspace and at an alt itude be low 5000
feet above mean sea level (amsl).
When t he pi lot submitted the flight plan, he was advised by the Briefing Officer that the route through the Ki lmore Gap was not
su itable for flight under visual meteorological cond itions (VM C). The pilot agreed to delay his departure until condit ions improved
in the Ki lmore Gap.
The pi lot and passengers then proceeded to the aircraft and after loading the aircraft was taxied for takeoff. The departure time
f rom Moorabbin was reported by the pilot as 0900 hours. No request for any update of the weather situatio n in the Ki l more Gap
area had bee n received from the pilot before departure.
Shortly after departure, the ai rcraft was identified on Melbourne radar after having inadverten tly entered Melbourne Control
Zone. The pi lot was instructed to maintain the aircraft 's present aHitude and heading, until about four minutes later at 0908 hours
when the pilot was cleared to resume his own navigation after reporting he had Yan Yean reservoir in sight.
At about 0918 hours, VH-DAJ was observed over Kil more at an altitude of approx imately 600 feet above ground level (ag l)
heading in a north-westerly direction. Shortly afterwards the pilot was asked by Melbourne Fl ight Service for his appreciation of
the weather in the Ki lmore Gap. In reply the pilot advi sed he was unsure of the aircraft's locat ion and was going to carry out a
180-degree turn; he also requested the aircraft 's bearing from Melbourne. The pilot was then advi sed that the aircraft was not
w ith in radar coverage and asked if the aircraft cou ld be climbed to 4000 feet amsl and remain in VMC, to which the pilot rep lied
that the ai rcraft was not in VMC at that time. The pilot was then advised that three minutes earlier his aircraft had been 30 nautical
miles north of Melbo urne and that if he turned to the south the ai rcraft woul d be expected to come w it hin radar coverage short ly.
Two minutes later Melbo urne Fl ight Service asked the pilot the d irect ion and the altitude at wh ich the aircraft was fly ing. The pilot
answered t hat the heading was 'one two zero' and then that the aircraft's level was 'two t housand '. This was the last transmiss ion
rece ived from t he aircraft.
Weather in the area at the t ime was reported as low cloud and rain. The search for the aircraft was hampered by the weather.
The wreckage was final ly located by a motorbike rider later in the afternoon. The initial impact had been in a slight r ight wing
low attitude on a heading o f approximately 135 degrees at a height of 2180 feet ams l on the slopes of Mt W illiam, the top of which
is 2639 feet amsl. Af ter t he initial impact, the aircraft had rolled inverted before striki ng the ground again, 70 metres beyond t he
initial point of impact. Fire broke out and engulfed the wreckage.
The investigation did not reveal any fault with the ai rcraft that would have contrib uted to the accident. Wit nesses in the area
reported that the pos ition VH-DAJ st ruck the ground was shrouded by cloud at the t ime of the acc ident.
03 May
8311027
Hughes 269C
Commerc ial 29
3600
None
1500
helicopter
The helicopter was weaving back and forth driving catt le. Height was about 30 ft and airspeed about 25 knots . The pilot heard a
loud bang and be lieved t he eng ine had fai led. An autorotat ion was carried out into trees.
The cause of the loud bang and the power loss reported by the pilot could not be determined. There was no suitable area
available for the subsequent autorotational landing ini tiated by the pilot.
05 May
8351016
Beech 95-C55
Commerc ial
41
5800
4600
Instrument rating 1st c lass or class 1
While cruising at 7500 ft , the pilot became aware of a fire behind the th rottle quadrant. An immediate descent was commenced
and attempts by passengers to exting uish t he f ire were unsuccessful. Aff er landing, the occupants evacuated the aircraft and
were again unsuccessful in extingu ish in g the fire.
The cause of the f ire was not determined. Attempts to cont rol the f ire by use of the portab le extingu isher were unsuccessful as
the item fail ed to operate.
Aviation Safety Digest 121 I vii
�I
FINAL UPDATES (The investigation of the fol lowing accidents has been completed. The information is
add itional to that previously printed in the pre li mi nary report)
FINAL UPDATES (The investigation of the following accidents has been completed. The information is
add itional to that previous ly printed in the preliminary report)
Date
Pilot licence
Date
Pilot licence
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
07Jun
8321046
Piper 28-R180
Private
49
230
10
None
While the aircraft was cruising at 2000 ft below an overcast at 2500 ft, a large bird struck the outer leading edge of the left wing.
12 Jun
8311036
Cessna P206D
Commercial
21
200
15
Instrument rating class 4
The pilot was unable to start the engine with the starter. He set the park brake, explaining to his passenger the foot brake operatio n and briefed her to slightly open the thrott le if the engine looked like stoppi ng after he had started by hand swinging the propeller. As the engi ne started the aircraft moved forward. The passenger inadvertently fully opened the thrott le, the ai rcraft collided wit h a fence and hangar door before coming to rest em bedded in the side of the hangar.
Th e cause of the malfunction in t he electrical system co uld not be determined.
17 Jun
8311037
Cessna 404
Commercial
40
8765
1336
Instrument rating 1st class or class 1
On approach the landing gear down indications were normal. However, when the nosewheel was lowered after touchdown, the
nosewheel leg collapsed and the nose section impacted the runway.
The rod end of the nosewheel retract rod had failed in overload prior to touchdown.
27 Jun
8311039
Cessna 182G
Private
55
549
395
None
While cruising at 1500 ft amsl the engine began to run ro ugh ly and backfire. The pilot was unable to recitfy the problem and shut
the engi ne down. A fo rced landing was carried out on a beach and after landing the pilot found a fire in the eng ine compartment.
He was unable to extinguish the fire until the arrival of a f ire tender from a nearby airport.
The engine muffler had deteriorated to the extent that it was torching onto the carburettor air intake duct and air box. Pieces of
the d uct and air box broke away and blocked the induction system. The torching induced the engine fire. The aircraft had flown
only 56 hours since the last major inspection wh ich was considered to have been inadequate. The engine cowls did not provide
accessibility for pre-flight inspection of the engine area.
03 Jui
8321053
Rutan Vari Eze
Private
52
4800
150
None
Followi ng receipt of advice that the aircraft had failed to return from a no-sar, no-details flight, searchers found the wreckage
washed up on the edge of a lake. A power line 20 metres above the lake surface and about 1.5 km from the wreck had been debraided over a two-metre length.
The aircraft had struck the power line which severed the right canard, a section of the right wing and the propeller blades. The
aircraft struck the water and the main wreckage floated to the shore of the lake. The investigation did not reveal any fault with the
aircraft that could have contributed to the accident and no operational reasons could be found for the aircraft having been flown
at low level over the lake.
12 Aug
8321061
Cessna A188-A1
Commerc ial
27
2573
Not known
Agricultu ral class 1
On the fourth run of a weed-spraying operation, the aircraft passed under a power line which the pilot had not seen. The power
line st ru ck the deflector cable which failed adjacent to the fin attach point. The top section of the fin and rudder mass balance
were severed and two rudder hinges failed , allowing the rudder to hang loose and foul the elevators. The· aircraft struck rising
ground 800 metres after the wi re strike.
The spray run was flown on a westerly heading into the afternoon sun. Although the pilot was aware of the position of the
power line, he did not see it on this occasion because of sunglare.
05 Sep
8331025
Cessna 182P
Private
47
703
33
Instrument rat ing class 4
Bei ng unable to cont inue to hi s desti nation because of deteriorati ng weather, the pilot decided to land at an airfield enroute. The
aircraft touched down about 140 m behind the strip thresho ld but then bounced. After the second touchdown the pilot applied
braking which had little effect. He then attempted to steer the aircraft onto an adjacent grass strip; however, the aircraft continued straight ahead, pass ing over two ditches and a fence before overturning.
The approach was carried out with only 20 degrees of flap set and at an airspeed higher than specified in the aircraft flight
manual. The strip had pools of water on it wh ich reduced the effectiveness of the brakes. The pilot did not initiate a go-around
after the aircraft floated and bounced.
05 Sep
8331026
Gulfstream 695-A
Commerc ial
59
9680
95
Instrument rating 1st class or class 1
After the gear was lowered d uri ng the approach, a no rmal gear down indication was observed by both crew members. The aircraft
touched down on the main wheels and as the nose was lowered the pi lot heard a loud noise and not iced that the nose attitude
was lower than normal. The nose was raised and when subsequently lowered the nosewheel contacted the runway and all
nosewheel functions operated normally.
The cause of the malfunction of the nosegear system could not be determined.
09 Sep
Commercial
8321069
38
Cessna A188B-A1
11000
2000
Agricultural class 1 with flight
inst ructor
The operation involved t he spray ing of a series of cul t ivated paddocks. The last swath run of the task was carried out along one of
the paddock boundaries. Shortly after the run was beg un, the aircraft struck a set of power lines. The tops of the fin and rudder
were torn off and the aircraft struck the ground 50 metres beyond the wires. The aircraft cartwheeled and came to rest inverted.
The pilot had a map of the area showing the position of the power lines. Prior to commencing the run he overflew the area to be
sprayed, to check the position of the wires, and now believes he mistook a spur line for the main line that was marked on his map.
The pilot saw the line after commencing the run but was unable to avoid the collision.
viii I Aviation Safety Digest 121
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
10 Sep
8311056
Burkhart As tir CS
Glider
44
900
120
Glider
,
During the course of a soaring fligh t it became necessary to make an out landing. A suitable landing area was not available and the
pilot elected to land in a ploughed field. During the landing run the right wingtip struck the rough ground, the glider ground looped
to the right and the landing gear collapsed.
The pilot misjudged his circuit and overshot his approach. He init iated a ground loop to avoid stand ing cane at the end of the
field. A tai lw ind component was present on final approach.
18 Sep
8321074
Piel-100
Commerc ial
26
437
3
Instrument rating 1st c lass or class 1
The pu rpose of the f light was to show the passenger the characterist ics of a t ailwheel aircraft. After a normal approac h and
touchdown, the aircraft was observed to go-around and f ly level at a low height above the runway . The aircraft was then seen to
climb steeply, stall and to impact the ground in a steep nosedown attitude wh ilst rotat ing to the right.
No fault was found with the aircraft that could have contributed to the accident. The pilot was inexperienced on the aircraft
type and did not maintain adequate flying speed when manoeuvring the aircraft after takeoff.
26 Sep
8321075
Cessna 1820
Commercial
25
450
25
Instrument rating 2nd class
After experienc ing erratic engine operation, the pilot elected to make a precau tionary landin g on a nearby golf course. The initial
approac h was unsatis factory and a go-around was made. As the aircraft t urned onto a base leg for landing the engi ne lost power
comp letely. The ai rcraft descended steeply, st ruck a television antenna and a tree, bounced off a sealed road and collided with
the boundary fence of the golf course.
The engine had failed from fuel exhaustion. The pilot had planned on a lower fuel consumpt ion rate than that recommended in
the aircraft operating manual for the power settings being used.
08 Oct
8321079
De Hav 82A
Private
45
350
5
None
After a one-hour flight in the local train ing area the pilot entered the circuit for a fullstop landing. The ATIS broadcast in dicated
that 10 knots of crosswind could be expected . The initial touch down was heavy and the aircraft bounced. The pilot then
attempted to land in a three-point attitude but t he touchdown was again heavy and the maingear partially collapsed.
The pilot was inexperienced in the aircraft type, and had limited experience on tai lwheel aircraft in general. Correct recovey
action had not been taken when the aircraft bounced.
09 Oct
8331029
Pitt s S1
Private
46
742
44
Instrument rat ing class 4
The aircraft was one of many which had flown into a barbecue at a private airfield. The pilot was asked if he would provide an
aerobatic display and during the day, carried out three. After completing the third display, the aircraft f lew past the gathering at
about 500 feet above the ground, pulled up steeply and turned through 180 degrees to land straight ahead. It then descended
steeply at low forward speed and struck the ground heavily in a nosedown attitude.
The pilot was inexperienced in low-leve l aerobatics. He did not maintain flying speed during a manoeuvre when attempt ing to
align the aircraft for final approach.
13 Oct
8321080
Piper 25-2351A1
Commercial
32
1700
550
Agricu ltural class 2
The pilot carried out an aerial survey of the area to be treated and commenced spraying. The ini tial run was made below power
lines crossing the centre of the crop and the third run was in the same direction. As the aircraft approached the power lines, the
pilot's attention was distracted and the windscreen and canopy struck the lower two cables. The aircraft turned to the right and
crashed into an adjoining field.
16 Oct
8341029
Piper 25-235
Commercial
27
486
295
Agricu ltural class 1
The pi lot was engaged in spraying a crop of lupins. The aircraft was observed to fly from one paddock to anot her on the property.
A sho rt time later a tree in that paddock was observed to be on fire. The wreckage of the aircraft was later found in the paddock.
The aircraft had struck the ground in an inverted att itude and was comp letely burn t out by the ensu ing fire.
No evidence of aircraft failure or pilot incapacitation was found. The reason for the loss of control leading to the accident cou ld
not be determined.
22 Oct
8321082
Cessna A 188-A1
Commercial
42
10500
500
Agricultu ral class 1
The ai rcraft completed a spraying run and landed on a s trip located in an oatf ield in which t he surrounding crop averaged one
metre in height. A sect ion of this crop which was growing on a low earth mound was half a metre higher. After touchdown, the
right wingtip entered this section of oats, t he aircraft swung rapidl y to the right and the left w ingtip and tailplane struc k the
g ro und.
The mown area was 15 m wide and the ai rcraft wingspan was 12.7 m. Although the pi lot had landed there on a previous f light,
on this occasion he did not maintain the aircraft in the middle of t he strip with sufficient accu racy to prevent the wing com ing
into contact with the crop.
26 Oct
8331031
Piper 25-235
Commercial
36
1350
750
Agricultural class 2
After the pilot had refuel led the aircraft , loaded spray and carried out a f uel d rain check, he commenced spray ing a nearby wheat
crop. Part way through a procedure turn at the end of a spray run , the eng ine lost all power. The pilot levelled the wings and after
avoid ing a farm house ahead, dumped t he spray load. The ai rcraft struck a power line, trees and the ground and fire broke ou t
immediately. The pilot escaped from the wreckage.
The cause of the engine failure could not be determined due to total destruction by fire. The pilot had poorly planned his spray
run pattern as the procedu re turn at the end of the runs was conducted over farm bui ldings. When the engine lost power, the pilot
had to manoeuvre the aircraft clear of the bu ildings thus reducing the time available for him to plan a landing.
Aviation Safety Digest 121 I ix
�FINAL UPDATES (The investigation of the fol lowing acc idents has been completed. The informat ion is
additional to that previously printed in the preliminary report)
FINAL UPDATES (The investigation of the following accidents has been comp leted . The information is
additional to that previously printed in the preli minary report)
Date
Pilot licence
Date
Pilot licence
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
29 Oct
8351027
Cessna 172N
Commercial
38
622
59
None
The pilot intended taking some friends for a local flight. The takeoff was commenced from the threshold of the 750 m gravel strip
with 30 degrees of flap set. The pil ot reported that the aircraft was not performing normally and when the stall warning sounded
he elected to land in a paddock. During the landing attempt the lef t wi ng struck the ground.
The pilot had only limited flying experience. He was concerned about the posit ion of obstacles at the end of the strip and used
a non -s tandard takeoff technique which degraded aircraft i;erformance. No contributing fault was found wi t h the engine or other
aircraft systems.
Bel l 47-G5
11 Nov
8341032
None
Commercial 26
2579
1980
helicopter
The pil ot was engaged in mustering a group of buffaloes towards a gate be tween two paddocks. As he began t o t ransition f rom
the hover to forward f ligh t , the pi lo t reported that the aircraft shook vio len tl y and the eng ine then lost all power. The aircraft
yawed to the rig ht, descended steeply and struck the ground.
Subsequent eng ine examinat ion and performance checks failed to detect any abnormal ity which could have caused the powe r
loss. The engine fai lure had occurred over scrub and at a height and speed such that a successfu l land ing cou ld not be exec uted .
01 Nov
8321083
Piper 28-R180
Private
22
275
25
Instrument rat ing class 3
There was a low cloud base in the ci rcuit area and the pilot concentrated on remaining clear of the cloud . He stated that he flew a
tight circuit and carried out downwind checks but omitted to lower the gear. The gear override selector was in the inoperative
position and the aircraft was landed with the gear retracted .
13 Nov
8341033
Schneider ES-49
Glider
26
111
40
Gl ider
The glider was aligned on final approach above the desired gl idepath. The instructor decided to demonstrate sidesl ipp ing as a
method o f losing excess height. At about 200 ft AGL the demonstration was discontinued but a high rate of sink persisted. T he
g lider landed 70 m short of the t hreshold and the pilot was unable to avoid obstacles during the ground run.
Meteorological condit ions prevai ling at the t ime were conducive to the formation of a down draft on final approach. The
inexperienced instructor cont inued the sidesl ip demonstration to too low an alti t ude for the prevai ling condit ions.
02 Nov
8321084
Amer Air 5A
Private
21
202
20
Ins tru ment rating c lass 4
On completion of several orbits at about 600 feet agl, the pilot applied full power to c limb to his intended cru ising altitude. A rap id
knocking noise was heard from the engine and the pilot discovered that the frequency of the noise was related to the throttle setting . He elec ted to conduct a precautionary landing on a nearby agriculturai strip. The aircraft touched down normally bu t du ri ng
the landing roll it collided with a temporary fence erected across the strip.
The engine was found to be serviceable and the origin of t he knocking noit>e was not determined . The noise apparently occurred at a fu ll-power setting and was also related to the pitch attitude of the aircraft. The owner of the aircraft had been aware of the
noise but had not alerted the pilot before the flight.
04 Nov
8321086
Piper 28-R201
Private
40
400
20
Inst rument rating c lass 4
The pilot believed that he had selected gear down as the aircraft turned on to base leg but it touched down with the gear
retracted.
Earli~r in the day the pilot had de-activated the automatic gear extension system. During the c ircuit he was distracted by other
traffic in the area and by sunglare. Although the gear warnin9 horn was su bsequently found to be serviceab le, none of those on
board the aircraft reca.lled hearing it during the approach.
06 Nov
8331033
Piper 28-140
Private
38
212
11
None
The aircraft had landed in a paddock with 10 cm long grass. While taxiing for the subsequent takeoff, the pilot conducted a
satisfactory acce lerati on check. On takeoff, the aircraft lifted off at 60 knots, cleared the boundary fence but then sank and struck
another fence. The impact tore out the right gear leg. The pilot was not aware of the fu ll extent of the damage but elected to d ivert
to Moorabbin and made a successful emergency landin g .
Although the pilot considered that the paddock was long enough for the inten ded takeoff, reference to the flight manual wou ld
have revealed that the distan ce available was not sufficient for the prevailing conditions.
06 Nov
8331034
Piper 25-235
Commerc ial
36
1400
800
Agricu ltu ral class 2
The pilot made one takeoff under a power line which crossed the strip 150 metres from the northern boundary. He then completed
a number of spraying runs. He uplifted the same quantity of spray and commenced the second takeoff in t he same d irection. The
aircraft passed under the power line but the undercarriag e and left wi ng struck the boundary fence. The pi lot dumped the load
and returned to land.
The pilot took off the wrong way on the one-way strip and encountered windshear from the nearby trees as he approached the
fence.
06 Nov
8321087
Piper 28-161
Private
33
95
48
None
The pilot was conducting a takeoff from a strip with a 2 per cent upslope. He reported that the takeoff was normal unti l the aircraft
had reached a height of about ~O ft at wh ich point the rate of climb decreased to zero. The stal l warning sounded and t he pil ot
lowered the nose and flew the aircraft back onto the ground. It collided with the boundary fence and the pilot then abandoned the
takeoff. The aircraft came to rest about 300 metres beyond the end of the strip.
The ground beyond the upwind end of the strip rose at a gradient of about 3 per cent. A fter the aircraft became airborne the
pilot selected the climb angle with reference to the horizon formed by the upsloping terrain. This resul ted in a higher-t han-no~mal
climb attitude and thus a decrease in the climb performance of the aircraft.
08 Nov
8321090
Auster 3F
Private
39
537
35
None
During the c~u rse of a local flight , st rong gusting winds were encountered and the pilot decided to return for a land ing. He stated
that as the aircraft was about to to uch down, 11 was affected by a sudden strong tailwind and the nose struck the runway. The
wooden propeller was shattered, both wingtips came in to contact w ith the runway and the tailwheel was torn off before th e aircraft came to rest.
When the aircraft was on late final app roach, a sq uall passed over the aerodrome. This resul ted in a change o f wind direction of
about 180 degrees.
09 Nov
8321092
Cessna 152
Sen ior
22
2500
1500
Fl ight instructor grade 1 or 2 with
commerc ial
instrument ratin g
The pil ot reported that after the aircraft struck a bird the eng ine began to overheat. It then started to run rough ly and the pilot
decided to land the aircraft on a golf course. After touching down on a fairway, heavy braking was applied and the nosewheel and
propeller dug into th e soft ground.
No evidence of damage due to the bird s trike was found . The eng ine rough runni ng had been caused by lead fo uli ng of several
.spark plugs and was not related to the birdstrike.
x I Aviation Safety Digest 121
20 Nov
8331037
Piper 28-140
Student
29
14
14
None
On the landing roll du ri ng a solo training exercise, the aircraft drifted to the left side of the runway. The st uden t pilot overcorrec ted and the aircraft ran off the runway. The nosegear folded back and the propeller struck the ground.
The pilot was carry ing ou t only her second solo f light and the loss of control was attributed to the whee lbarrow effec t.
22 Nov
8331038
Cessna 172M
Student
56
22
22
None
A fter a period of dual training, the pilo t was sent on his f irst solo flight. The landing approach was made at 75 knots to the f lare
point and touchdown was in a three-po int attitude. The aircraft bounced, the nose dropped and the second touchdown collapsed
the nosegear. The aircraft skidded off the runway and overturned.
24 Nov
8331039
Cessna 210L
Private
36
337
50
Instrument rat ing class 4
On fina l approach the pilot opened t he thrott le to adjust the g lide path but the engine failed to respond. The aircraft landed in a
paddock about 150 metres short of the aerodrome boundary and ran t hrough a fence and a ditch before com ing to rest with the
nosegear assembly dislodged.
The eng ine stopped because of fuel starvation . Inspection of the aircraft revealed only a smal l quantity of fuel remained in the
aircraft tanks, and the fuel lines to the eng ine con tained no fuel. At t he previous land ing po int the aircraft had been parked o n
sloping ground and fuel had been observed draining from the w ing vent. The fue l gauges in the aircraft were fau lty and the pilot
had not visually checked the tank contents before departure . The person who had seen t he f uel drain ing from the aircraft had not
brought t he matter to t he pilot's at tention.
27 Nov
8331040
Piper 28-140
Private
52
340
110
None
The pil ot had previously checked the strip dimensions and, on arrival over the top, made a thorough appra isal of the area. He
noted that there was a crossw ind from the right gusting to 15 knots. He stated t hat on short final approach at a low height the aircraft dropped suddenly and, despite the application of power, struck the lip of a ditch . The gear legs were detached and the aircraft slid to a stop on the runway.
The pilot had planned to touch down on the th reshold. No allowance was made for the gusty wind cond itions and windshear
was encountered at the crit ical point of the approach.
03 Dec
8351028
Czech Blanik L 13
Glider
34
550
150
Glider
At about 50 feet after liftoff on a w inch launch, a winch power failure occurred . The instructor disconnected the tow cable and
landed straight ahead. In the resulting heavy landing the main wheel was pushed upward throug h t he cockpit floor.
The instructor, who had been on duty for most of the day, was slow to take control of the glider when t he winch system
inadvertently c hanged gears. He al lowed the speed to reduce excess ively and flared late for the land ing. The wind at the t ime was
gust ing between 10 and 25 knots.
04 Dec
8321095
Piper 30
Senior
24
3700
800
Instrument rating 1st class or c lass 1
commerc ial
and f ligh t instructor
The pilot was undergoi ng initial twin-eng ine endorsemen t training . On t he thi rd touch-and-go landing, the instructor ret racted t he
flaps , advised t he pilot that he had done so and instructed him to proceed with the takeoff. The pi lot inadvertently retracted the
gear and the aircraft settled to the runway.
07 Dec
8311080
Pitts S1-S
Private
25
500
295
None
At the end of the land ing roll, the pilot unlocked the tailwheel and commenced to tax i back along the landing path. Whi le travelling at about 20 knots with the wind from the right rear-quart er, the ai rcraft began to veer to the r ight. The pilot attempted to correct the situat ion but the ai rcraft g round looped to t he right and the lower left w ing struck the runway.
08 Dec
8321096
Cessna A188B-A 1
Commercial
39
3250
880
Ag ricul t ural c lass 1
The aircraft was being used to spray a rice crop. Wh ile conduc t ing the final c lean-up run in an east-west direction at the southern
end of the paddoc k, and in the lee of a line of t rees, the pilot f lew the aircra'ft under a power line. The aircraft was affected by a
gust of w ind which caused it to rise and st rike t he power line with the wire deflector cable. The power line rode up the def lector
cable, pushed the fin aside and cut the rudder off above the top rudder hinge. The pi lot was ab le to retain cont rol of the aircraft
and land it without fu rth er damage.
Aviation Safety Digest 121 I xi
�FINAL UPDATES (The investigation of the following accidents has been completed. The information is
additional to that previously printed in the preliminary report)
Date
Pilot licence
Record number
Age
Aircraft type
Hours total
Hours on type
Rating
10 Dec
8311081
Cessna 1820
Private
43
420
250
Instrument rating class 4
The aircraft had not been flown for about two months. During that time it had been washed regularly and had been parked in the
open. The pilot conducted a water check before ground running the engine and he then elected to fly the aircraft. Further water
checks were conducted before the aircraft was positioned for takeoff. At about 200 ft agl the engine failed completely and the aircraft overturned during the subsequent forced landing.
Although the pilot carried out fuel drain checks prior to flight, he did not check the fuel sump drain. After the accident the
carburettor float chamber was found to contain only water.
14 Dec
8331042
Cessna P210N
Private
47
2200
2000
Instrument rating class 4
After touching down on a mown area of a paddock, the aircraft became airborne over a slight hump. Following the second
touchdown, the pilot applied the brakes but was unable to prevent the aircraft hitting a gate. It then ran across a road and struck
an earth bank, collapsing the gear.
The strip length available was insufficient for a safe operation based on the flight manual performance. The pilot also landed
downwind and overshot his approach. A power line at the upwind end of the strip precluded a go-around had such an action been
considered.
18 Dec
8331043
Volmer VJ21
Private
50
950
325
None
At about 400 feet agl, on climb alter takeoff, the pilot reported hearing a loud bang. Engine power was reduced but the source of
the noise could not be located. As power was reapplied the engine ran roughly and the pilot decided to land the aircraft in a paddock. During the approach, the pilot realised the aircraft was overshooting and forced it onto the ground to avoid a fence. The left
wing struck the ground and the aircraft turned through 180 degrees before coming to rest.
The source of the bang reported by the pilot could not be established but it is probable that one of several loose objects in the
cabin fell on the floor. The roughness from the engine on re-introduction of power is thought to have been caused by airflow at
low speed - a known phenomenon in this aircraft.
24 Dec
8331044
Czech L40
Private
53
539
451
None
During the cruise the engine began to misfire and lose power. The pilot carried out a precautionary landing on a road but during
the landing roll the left wing struck a road signpost. The force of this collision caused the aircraft to swing to the left and it ran
throug h a fence before coming to rest in an adjacent paddock.
The engine malfunction was attributed to fouled plugs from oil escaping past the piston rings. Excessive wear of the pistons
was caused by the use of an incorrect oil during the running-in period. In his haste to land the pilot selected an unsuitable area.
30 Dec
8341034
Cessna 172N
Private
37
162
162
None
The pilot reported that as the aircraft was being manoeuvred for landing with a right crosswind, a gust from the left lifted the left
wing and caused the aircraft to touch down to the right of the strip on a heading about 30 degrees from t he runway direction. During the landing roll, the aircraft was turned towards the runway but the right wing and landing gear collided with a parked car.
The car was positioned outside the boundaries of the flight strip. When he experienced directional control difficulties before
touchdown , the pilot did not carry out a go-around.
Unrated in IMC
The question of pilots without an instrum
conditions is always topical. In that con
lessons for other pilots.
I had commenced pilot training five months prior to the
flight and had accumulated 11 hours following the
lifting of my area restriction one month earlier. I was
thus very inexperienced and my only advantage was
that my training lessons were still recent.
The purpose of the flight was to return to Melbourne
after a long Easter weekend in Sydney. There were
three passengers, two of whom were expected back at
work on the Tuesday while I was expected back a t work
on the Wednesday. We had been staying with a friend
of mine in his two-bedroom flat. H e did not know the
other three and as the weekend wore on so did his
patience with one of my passengers.
The flight up had been via Albury and Canberra and
had been uneventful. I had planned weeks before to
travel coastal on at least one of the two trips and
intended to decide closer to the time whether it would
be on the way up or back, depending on the weather.
So I was in many ways attuned to the idea of bad
weather on this return leg.
After reviewing the meteorological forecast, I
discussed the situation with the gentleman behind the
counter who said that there would be visual
meteorological conditions but marginal on the way
back. He then related his experiences of people who
had been in a hurry to get back home after the Easter
weekend who had not made it.
There were many airports down the coast on my
intended route and any was suitable for landing if the
weather proved to be worse than forecast for the rest of
the route. The aircraft did not have HF for the southeastern region and so a Sartime flight was necessary
due to the low altitude required.
I decided on the basis of the above factors to head off
on the flight with the intention of seeing if I could get
back in Visual Meteorological Conditions as forecast,
despite intermittent changes at some of the V ictorian
airports. I was planning to stop at any of the many
airports on the coast if required . I had the aircraft fuel
tanks filled to the brim and briefed my passengers to
remain in seat belts all the way and gave them a forced
landing briefing, knowing that in the event of engine
fai lure at that altitude I would have no time to repeat it
due lo the low level anticipated on the route. The
remainder of the preparation was routine.
The flight
I was pleased to see that the conditions down the
N.S.W. coast were better than forecast and that each of
the airports tha t I passed was suitable for landing. In
xii I Aviation Safety Digest 121
ering instrument meteorological
reader contains a host of valuable
particular the weather seemed to clear considerably
about the south-east point a nd I was able to maintain
2000 feet for some time. There was some occasional low
stratus which forced me down again 10 miles after
Malacoota. Nevertheless, when I passed Orbost I had a
clear view of the strip which was quite suitable for
landing, despite low stratus at about 1000 feet. I made
a mental note o f each of the en route airports with a
view to returning there if needed , and continued .
I had tried to contact Melbourne Flight Service Unit
(FSU) from Cape Howe but was unable to do so until
just before Lakes Entrance. I asked whether the East
Sale restricted area was operational a nd received a very
broken reply which I eve ntua lly worked out was saying
that R390 was active but the General Aviation lane was
clear. For a brief moment I thought of requesting
coastal clearance but the communication was so poor
that I did not bother. Nor did I bother to ask for
weather reports of the area for the same reasons and
decided to land the aircraft at the next suitable airport.
By Lakes Entrance the weather had deteriorated over
the coast and I could not clearly see an ALA which was
marked on m y map somewhat inland. I h ad no other
information about the ALA and rather than search in
below Visual Meteorological Conditions I pressed on
for Bairnsdale. I did this on the basis that it was further
inla nd and would therefore (I thought) have less of the
coastal cloud than I had so far seen. Thus, I tracked up
the lakes past Metung, keeping to the north lake. I
dialled up the NDB and aimed for it, not having the
airport in sight at that time.
Loss of Visual Meteorological Conditions
As I crossed the shore at 500 feet I struck a wall of
cloud which I suddenly a pprecia ted was down to the
ground . However, at this time I was at the end of a
lake surrounded on three sides by what I now realise
was this same cloud, and terrain which I did not know
other than it was below 660 feet. The ground in front
of me was sloping up, further d isturbing me about the
prospect of flying into ground , trees or power poles.
The cloud I could now see was sloping down. I decided
not to turn around as it was not safe. At that time and
position a ny turn would have taken u s into the cloud
(which appeared to be very close indeed) a nd I would
then have been committed to recover from an
instrument turn at 500 feel not knowing how hi gh that
was above ground level, if at all . I thus elected to climb
through the cloud as the safest alternative with my
Aviation Safety Digest 121 I 13
�limited instrument flight experience and seek assistance.
My decision was further forced by entry into the cloud
a fraction of a second later which demonstrated that the
cloud was closer than I had thought and would have
meant that virtually the entire turn (if I had elected to
do this) would have been in cloud. I should emphasise
that this decision process took a second or two to make
and we were still travelling at about 140 kno ts.
On climb I turned on the pito t heat , which remained
on from there an d , o n later occasions in cloud where I
was not on a high power setting, I used carburettor
heat. I radioed a Mayday call that went somethin g like
'Mayday, Mayday, VFR pilot in cl imb through cloud
east of Bairnsdale. Request urgent navigational
assistance'. This call was not heard due to low altitude.
I had no trouble keeping the wings level but did wand er
off course si nce in my near panic I was not using a full
instrument scan but rather was concentrating on th e
artificial horizon . After about 2 m inutes in the cloud I
became very worried about what had happened an d the
danger I had inadvertently taken my passengers and
m yself into. An article on the back of the A viation Safety
D igest suggesting that we did not have much longer to
live came into my mind. At one stage I though t that
the easiest th ing wou ld be to just give up and go into a
spiral dive and get it over with quicker. I was able co
quell these fears by logical reassurances that my task
ahead was just to fl y the ai rcraft level, a task that I had
had at least 5 hours experience in over the past few
months, an d to seek assistance from the rsu; however,
I hope never to experience such fear ever again. After
this time I ignored the passengers' presence and
concentrated on getting the aircraft down safely. I did
not relax th is concen tration until some time after
landing.
After I broke through the cloud at 4000 feet and set
the a ircraft up for a cruise I was then in continuous
contact with ATC.
I then gave up a lot of the responsibility for
navigation to ATC, and dea lt wi th flying the a ircraft.
This happened for a number of reasons. Firstly, I was
very disturbed about the situation I was in and was
happy to give away some of my responsibilities and I
was under the mistaken belief that they had heard my
earlier call. Secondly, ATC was ask ing me qu est ions
about my enduran ce which I was unable to give
precisely a nd this acted as a distraction. Thirdly, I
made the simplistic deci sion to head 270M towards
Melbourne where I thought that the weather wou ld be
better and that radar assistance would be avai lable to
assist me in a descen t through cloud over Port Phillip
Bay, a possible action wh ich I had suggested to ATC.
I did not, however , until som e time later, realise that
because I had been tracking coastal, I had left the DG
unadjusted since Sydney. The effect of this heading
deci sion was to take rne on a track in excess o f 280T
because of t he prevaili ng wind. This led m e further into
the north and its high country.
I was at th is stage stuck in between two layers o f
cloud at 4000 feet and these layers gradually merged. I
did a back bearing from Eas t Sale and Bairnsdale NDBs
and found I was 20 miles north o f East Sale and then
checked the spot heights in the ranges and saw that the
highest was abo ut 5000 feet and thu s, agai nst the
previous instruction of ATC to stay in visual
meteorological condi tion s which were rapidly reducing,
14 I Aviation Safety Digest 121
I elected to climb to at least 6000 feet through cloud
and notified them of m y inten tions.
This second time in cloud was less worrying since I
had had more time to make the decision and I had
steadied myself since my last episode. I did not,
however, give enough thought to the possibility of
surface ice, which fortu nately was not a problem. On
climb my scanni ng was better and when I got to 7000
feet I elected to maintain level flight in cloud rather
than climb higher. During this time I inadvertently
entered what must have been a weak cum u lo-nimbus or
a cum ulus as there were indicated updrafts and
downdrafts in excess of 1000 feet per minute. I was not
aware of any excess gravity forces, be ing easily able to
ma in tain the wings level, and the indications may just
have been pressure changes but I was too preoccupied
to answer a radio call from ATC at the time. There
were CBs forecast that day and I was very lucky that I
did not enter one of them.
Another aircraft had been sent up to help me out and
the presence of this other pilot in the ai r was a great
morale booster and rel ieved a lot of the feelin g of
loneliness. After about 10 minutes I came out of the
cloud, again being between layers. I now con tinued on
my new heading of 225M to bring me td Moorabbin
from my last plot.
Eventually, I was located on radar squawking 7700,
was identified and instructed to change to 1700. I was
then vectored south and found a break in the clouds
over a burnt-out bush fire area with cloud scudding
about the tops of the trees. I decided not to risk this
area and continued. Further south I found a trough-like
gap in the clouds which was very narrow (about 300
metres) and quite long (about 2000 metres) . At this
stage it appeared to me as the parti ng of the R ed Sea
and was greeted as such. I requested my position a nd
when l found that I was near Longwarry and was then
able lO see that the cloud appeared to be 2000 feet AGL,
I went into a rapid descent of 1000 fee t per minute to
get th rough it without h itting cloud at the other end.
After breaking through the gap I was able to iden tify
the Princes Highway a nd headed along it towards
Moorabbin at 1500 feet. On approach ing Pakenham I
was in structed to hold the re and after some hesitatio n
about the surface , conducted a precautionary landing as
instructed wh ich was totally uneventful. I then
confirmed to ATC that I was safely on the ground and
intended to remain there .
Summary
Unfavourable factors
1. The peculiar cloud which over the water was quite
high a nd then merged down to the land over the
coast. This I h ad not seen before and d id not really
a ppreciate un til just before I went into it.
2. The position at the end of the lake which acted as a
cul-de-sac forcing me up rather than allowing me to
turn.
3. My relatively brief experience of instrument flying
and my general inexperience as a pilot.
4. The fact that we had been travelling so low as to
preclude VI-If radio communication in a n aircraft not
fi tted for HF in that region . This really isolated me
from advice on actual weather which I otherwise
would have sought.
Favourable factors
1. The continuing help and instructions of the ATC staff
throughout the flight.
2. The moral support and advice of the other pilot sent
up to help me.
3. The high standard of my q ui te recent flying training
which covered many tasks that were required of me
and prepared me to deal with emergencies.
4. A reliable a nd easy-to-handle aircraft which although
I had only just learnt to use responded as antici pated
in all situations.
5. A recent purchase of a set of headphones which was
a crucial factor in freeing my overworked hands and
ears. They a llowed me to concentrate entirely on the
task at hand a nd isolated me from the passengers,
a nd them from the gravity o f the situation which
they d id not fully a ppreciate until after we had
lan ded .
Errors of judgment
1. To leave in the first place when the weather a head
was marginal. Th is I feel was a rel ative error as I
was subsequently in a position to land at several en
route airports with adequate weather conditions and
this had been a major planning consideration. But it
was this very flexibili ty which caused me lO con tin ue
beyond those a irports with adequate weather.
2. Not to turn back from Lakes En trance to a known
suitable airport. This was m y major error, as was
m y conti nu ed flight towards Bairnsdale, for even
though I was in V isual Meteorological Conditions it
was at the very limit. W hat I did was legal, a nd I
could have turned aro und a t any time before I hit
the cloud, but when I did it was too late.
3. Not to make a reasonable flight plan once above the
clouds using the a ids available. In retrospect I should
have headed st ra ight for the East Sale NOB and then
on a track to La Trobe Valley and then to the
M oorabbin NO B. This would have been safer than
the route I took wh ich eventually led me up to the
Upper Yarra Reservoir. It is possible that if I had
kept to the La Trobe Valley I could have kept in the
gap between the clouds, whi ch reduced as I headed
fu rthe r north on my 'westerly heading', and thus I
could have avoided a hazardous second entry into
cloud.
I have not included my climbs into cloud as errors,
as I believe that in the situations described they were
the safest actions available and given this same si tuation
I would do the same again. However, the level of fear
that I felt wh ile doing it and the risks of ice , severe
turbulence with structural failure, engine failure, etc.,
combine to make me much more wary than before.
Lessons learnt
l. I have learnt to be more demandi ng of good weather
conditions and I would not leave on such a flight in
similar conditions again, nor will I be unduly swayed
by the exigencies of work , commitments or personal
ties.
2. The lesson from m y second error has been my most
valuable which I have very firmly learnt a nd my own
standard of Visual Meteorological Conditions is now
significantl y higher than the legal one.
3. My third error I hope never to be in the posi tion of
making again, but it is a lesson about planning that
I will keep for diversions· in V isual Meteorological
Conditions.
4. I have generally learnt a lot abou t fl ying from this
experience, which will improve my standard of
fl igh t.
Lastly, I would like to thank everyone who was
involved in assisting me and am most deeply grateful.
Editor's comment
This pilot deserves full credit for the calm a nd rational
way he acted after placing his passengers and himself in
a potentiall y hazardous situation. His decision to call
fo r assistance straight away was particularly wise, as
once it was given , it relieved h im of much of his
workload, en abling him to concentrate his efforts
toward retaining control of the a ircraft in cloud.
Other key points arising include:
• the danger of allowing external factors to affect a
decision of whether to fl y or not, despite predicted
poor conditions;
• the 'suddenness' with which the pilot found he had
entered cloud;
• the hazards of 'pressing on' into obviously
deteriorating weather ; and
• the extreme workload faced by pilots without an
instrument rating who a Uow their aircraft to
penetrate adverse weather.
In this case, the pilot was perhaps fortunate that help
was readily available . Acknowledging that the pilot did
well once he had placed h imself in this dire situation,
the fac t remains that, in his acco unt of the incident a nd
his actions, there arc obvious examples of his
inexperience and inadequ ate a bility to make correct
decisions. This is likely to be the case with any unrated
pilot who flies in IMC.
Doubtless there are many un ra ted pilots who have
penetrated IMC uneventfully. For many, however , it
has proved to be a fatal d ecision . Statisticall y, the facts
a re that it is a highJ y dangerous practice. This
occurrence was typical in that th ere were man y
opportunities - a t the pre-flight meteorol ogical
briefing, and in ll ight - for the pilot to reach the
correct , safe decision; that is, to cancel the flight , or to
turn back or divert well before approaching
deteriora t ing weather. Regardless of exceptions, this
remains the only prudent and safe course of action •
Aviation Safety Digest 121I15
�SERIOUS ICING - ANY POWER
MODERATE ICING-CRUISE POWER OR
100
SERIOUS ICING -DESCENT POWER
90
SERIOUS ICING-DESCENT POWER
80
LIGHT ICING- CRUISE OR
DESCENT POWER
60
50 RELATIVE
HUMIDITY
:
_:. •·
.
~
..
··~
·· · ..;·
40
•: .
.
-·:· .
30
20
.- ..·-
------ ----
- --
·,:
--------
J--~-
~-------------
One of the perennial topics of the Aviation Safety Digest is
that of induction icing, perhaps more commonly
referred to as carburettor icing. Education on this. topic
is most important, for accident and incident records
continue to show icing as the probable cause of a
number of engine power-loss occurrences.
While the phenomenon is by no means limited to the
colder months of the year, the on set of winter makes a
general review of carburettor icing worthwhile.
This article d iscusses a number of aspects and
procedures which are generally applicable to most GA
aircraft. The point must be stressed , however, that
when educatin g yourself on the ' ins and outs' of this
important operational technique, it is essential that you
refer to your aircraft' s Pilot's Handbook/Owner's
Manual/Operations Manual to ascertain the exact
procedures stipulated b y the manufacturer.
Indications of induction icing
The possibility of induction icing should always be
considered when the iemperature is between zero and
plus 20 d egrees Celsius, with a relative humidity
greater than 50 per cent, or when the temperature is
below freezing with visible m oisture in the air. The
chart opposite provides a guide to icing conditions,
relatin g engine power settings to dry bulb temperature
and relative h umidity.
The effect of induction ici ng is a gradual, progressive
decline in the power delivered by the engine. With a
fixed pitch propeller, this is eviden ced by a loss in
eng in e RPM and a loss of altitude or airspeed unless the
throttle is slowly advanced. With a con stant speed
propeller, there will normally be no change in RPM but
.the sam e decrease in aircraft p erformance will occur.
16 I Aviati on Safety Digest 121
0/0
With a m anifold pressure gau ge, a decrease in manifold
pressure will be noted before any significant decrease in
engine RPM or aircraft perform ance . With an exhaust
gas temperature indicator, a decrease in exhaust gas
temperature will occur before any noticeable decrease in
engine and aircraft performance. If these indications are
not noted by the pilot and no corrective action is taken,
the decline in engin e power will probably continue
progressively u nti l it becomes necessary to retrim to
maintain altitude ; and engine roughness will occur
probably followed by backfiring. Beyond this stage,
insufficie nt power may be available to m a in tain flight;
and complete stoppage may occur, especially if the
throttle is moved abruptly.
DRY
•
Preventive or remedial actions
To prevent accidents resul ting from intake icing, pilots
should regularly use carburettor heat under conditions
known to be conducive to icing and be alert at all times
for indications of icing.in the induction system . The
following precautions and procedures will tend to
reduce the likelihood of in take icing problems:
• Periodicall y check the carburettor heat systems and
controls for proper condition and op eration.
• Start the engine with the carburettor heat control in
the COLD position to avoid the possibility of damage
or fire should the engine backfire during start up.
• As a pre-flight item, check the carburettor heat
effectiven ess by noting the powe r drop (when hea t is
applied) on run-up.
• When the relative h um idity is a bove 50 per cent and
the temperature is below 20 degrees Celsius, a pply
carburettor heat immediately before takeoff to
remove any ice wh ich may have been accum ulated
5
0
•
•
•
•
BULB
---- --~
-
10
15
TEMPERATURE oc
during tax i and r un -u p , and then return the control
to the COLD position before commencement of
takeoff. Generally, the use of carburettor heat for
taxiing is not recommended because of possible
ingestion of foreign matter with the unfiltered air
admitted with the control in the HOT or ALTERNAT E
AIR position.
Conduct takeoff without carburettor heat, unless
extreme intake icing conditions are present.
Remain alert fo r ind ications of induction system
icing during takeoff and climb-out, especially when
the relative hum idi ty is above 50 per cent, or when
visible moisture is present in the atmosphere.
With instrum entation such as carburettor or mixture
tem perature gauges, partial heat should be used to
keep the intake temperature in a safe range. Without
such instrumentation, full heat should be used
intermittently as considered necessary.
If induction system ice is suspected of causing a
power loss, apply full heat or alterna te air. Do not
disturb th e throttle u ntil improvement is noted.
Expect a further power loss momentarily and then a
rise in power as the ice is melted .
If the ice persists after a period with full heat,
gradually advance the throttle to full power and
climb at the maximum rate available to produce as
m uch heal as possible. Lea ning with the mixture
control will generally increase the heat but should be
10
------- ~~
20
used with caution as it may stop the engine under
circu mstances in which a re-start is impossible.
• Avoid clouds as much as possible.
• H eat should be applied for a short time to warm the
induction system before beginning a prolonged
descent with the engine throttled back, and left on
during the descent. Pilo ts should be prepared to turn
the heat off after power is re-applied to resume level
flight or initiate a go-around from an abandoned
approach, but once again the manufacturer's
instructions for the aircraft are the final autho rity .
• Remember that while intake icing is most likely with
temperatures below 20 degrees Celsius and relative
humidities above 50 per cent, it can occur outside
those parameters. The possibility of icing increases
as the tern peratu re decreases (down to zero degrees
Celsius) and as the relative humidity increases .
Summary
All pilots must know the conditions conducive to
carburettor icing and the preventive or remedial actions
appropriate to their particular aircraft. The effects and
recommendations described in this article are general in
n a ture. Pilots must refer to all available operating
instructions pertaining to their aircraft to determine
whether any special considerations or procedures apply
to its operation •
Aviation Safety Digest 121 I 17
�Bureau of AirSafety Investigation
February 1984
Studies have been carried out in both Canada
and the U.S.A. to determine the societal costs to
the community resulting from aircraft accidents.
A similar study has recently been undertaken
within the Bureau of Air Safety Investigation in
an attempt to provide a quantitative dimension
to the measurement of aircraft accident severity
in Australia. The results, although preliminary,
make interesting reading.
First, some brief comments ought to be made about the
co nceptual a nd methodological problems associated with
accident cost resea rch. The concept of 'social cost' , as it
appl ies to aircraft accidents, needs to be clarified. There
a re in fact three distinct concepts of cost which overlap
to some extent, namely:
• Financial costs or accounting costs associated with
day-to-day receipts and payments in the econ omy .
• ' R eal ' economic or resource costs whi ch a re a
measure of the value of scarce resources produced
a nd consu med in the economy (e.g. would exclude
some fina nc ial transactions such as the sale and
purchase of land or a u sed motor vehicle, since no
new scarce resources are produced or consumed).
• Social costs. This is a broader term and refers to the
value of goods and services generally provided by the
public sector of the economy because supply cannot
be efficiently or adequately achieved by the private
sector, e.g. roads, education , defence and
airways/airports faci lities. Environmental pollution is
recogn ised as a further category of social cost
involving the imposition of external costs upon
society which are not full y met by the producer or
con sumer.
18 I Aviation Safety Digest 121
The costs associ ated with aircraft accidents belong in
th e social cost category because of the external cost
effects upon society, such as hospital, police and
accident in vestigation services, a nd also a signi ficant
co mponent of non-market and intangible costs,
including pain and suffering, grief to famil ies and
inconvenience to the community. Therefore, for the
purposes of the stud y, accident 'costs' fell within the
broad term 'societal costs', meaning that they include
social and economic costs associated with aircraft
acciden ts. The purpose of accident cost ing is to iden tify
an d measure the real resou rces di splaced as a result of
acciden ts, but quite clearl y not a ll factors can be
identified or measured in mo netary terms .
There are two principal methods o f determining
accident costs :
• The ex post, or loss accounting, a pp roach whi ch is
based on a measurement mainly in national income
accoun ting terms.
• T he ex ante , or 'willi ngness to pay', concept based
on the amoun t in dollar terms that individuals
(society) are prepared to pay to reduce the risks of
future accidents.
Both of these approaches are, however, subject to a
number of shortcomings. Although the ox ante
approach is conceptually more a ppropr iate, the most
common approach has been the 'loss accounting' or
'after the event' hi storical costing of accidents. This was
the met hod employed in th e aircraft accident cost study.
The main drawback to loss acco un ting accident costing
has been the· approach to val uation o f loss of human
life . De termini ng a m one tary val ue for human life is
probably the most contentious issue in accident costing
but, despite its emotional con notation, it is necessary
for socie ty lo place a value on life in its public
expenditure decision makin g. Although many wo uld
consider that the value of human life is 'infinite', the
fac t that not all possible safety projects or programs arc
actuall y implemented is clear enough evidence that
society does implicitly place a n upper limit on this
value.
For this particular stud y, the h uman capital or
foregone incom e method was used to val ue human life.
This has been the m ost frequently applied method in
a ccident studies. It considers a fatal ity to be a loss to
society of the expected future income of the indi vidual
(production/consum pt ion equivalent) be tween the t ime
of premature d eath and th e end of the normal working
lifespan. This method of valuat ion prod uces a
' minimu m value' estimate of the value of life . Those
no t working for monetary reward, e.g. homekeep ers
and the unem ployed, are included in th e overall
accident sample b y attributing to them a n in come level
equal to the workforce average fo r each age group. It
should be emphasised that there is no apparent readi ly
available, ideal solution to the problem of valuation of
huma n life and that the fatality and serious inj u ry costs
d etermined from the study represent minimum values.
Main findings of the report
Preliminary accident cost esti mates were calculated for
1980. In that year there was a total of 253 General
Aviat ion accidents involving 56 fatalities in Australia.
There was a total of 28 gliding accidents with fi ve
fatalities. The total ex post cost to the comm uni ty of
aircraft accidents in 1980 was app roximately
$31 million. Two cosr components accounted for around
78 per cen t o f total an nual costs : foregone income and
ai rcraft hull damage and loss. Aircraft damage/ loss was
estimated at approximatel y $6 mi llion although the loss
of just two aircraft, a Beech Super King Air 200 and a
Swearinger Metrolincr, accounted for a significant
p ro port ion of this .
The average cost of a single fatality was calculated at
$482 OOO (1980). T his figui-e was derived from the age
a nd income profiles of users of aviation services and
th us reflects a uniform value of life for the av iation
populatio n al risk. O wing to the lack of data on
Australian aviation sector income profiles, it was
co nsidered feasi ble lo use data derived from an income
su rvey undertake n in Canada.
The study fo und that quite significant hospital and
medical resources were called upon despite the
relatively few se rious injury cases. Twenty-six cases in
1980 requ ired nearly 1000 hospital bed days with
h ospitalisation periods ranging from two days to over
six months. Approximately half of these cases sustained
spinal inj uries, incl udin g one case of paralysis as a
result of a gliding accident. Hospital and medical costs,
however, con tributed onl y approximately 1 per cent of
total accident costs.
H avin g develop ed a framework of aircraft accident
cost and arrived at a figure for the cost of a fatality, it
is then possib le to determine the proportion of total cost
att ributed to the variou s categories of flying . This will
Check your fuel contents -
give an indication of the specific areas where resources
need to be directed to reduce the risk of accidents and
as a consequence reduce total accident costs. As we
would expect the cost of accidents for scheduled
Regular Public Transport operations is relatively low
per hour and relati vely high per accident. I n 1980 an
accident in the commuter category (now Supplementary
Airline or SAL) with 13 fatalities contributed to over 20
per cen t of total accident costs for that year. Yet
commuter flying hours were only 7 .4 per cent of the
total hours flown for all categories, and commuter
accidents comprised 2.1 per cent of total accidents.
During thl' years 1977-81 , 'private/business' flying
accounted f(>r about 32 per cent of total flying activity
but 48 per cent of total accidents and around 55 per
cent o f all accident costs.
Gliding activity contribu ted significantly to accident
costs in 1980 at around 8 per cent of total costs while
accounting for around only 4.4 per cen t of total flying
hours. In 1981, gl iding accounted for approximately
10 per ceni of total costs.
The report concludes that the preliminary cost
estimates need careful qualification in their use and that
scope exists for refinement of the data in any future
research. H owever, the framework of costs developed
from the study provides a set of minimum social cost
estimates for Australia capable of some application in
the evaluation of air safety programs •
visually
A P iper PA-18 had been fully refuelled late in the
a fternoon in readiness for a flight the following
morning. R efuelling was carried out by the aircraft's
pilot.
During h is preflight inspection the next day the
pilot confirmed that the fuel caps were tight but,
because he had pe rsonall y refuelled the aircraft, and
it had not been flown since, did not lift the caps to
check the fuel conten ts visually. He did, however,
ch eck the fuel gauges. In the Super Cub these are
di rect read ing sigh t gauges in which a floating ball in
a clear tube shows the level of fuel in each tank.
Because of the d esign of the sight gauges the floating
ball can not be seen when the tank is either
com pletely full or completely empty. G iven the
circumstances described thus far , when the pilot
checked the gauges and could not see either floating
ball, it confirmed in his mind that both tanks were
full .
Startup and takeoff were normal. H owever, about
five m inutes after departure, with the left fuel tank
selected, the engine cut out. The pilot changed to the
right tank and power was restored. Abou t three
min utes later the engihc cut ou t again. An
emergency was declared and the aircraft configured
for a forced landing. This was successfully effected
on a road, but as the aircraft was slowing down to
abou t taxi speed a gust of wind caused it to drift to
the right and the right wing clipped a tree . The
aircraft ground looped and tipped on its nose.
Comment
Apparently the AVGAS from the Super Cub had been
drained out overnight by a thief, leavin g only
enough for the brief, ill-fated flight described above.
It is difficult not to sympathise with this pilot: this
was an unfortuna te and unlucky accident. The
occurrence also h ighlighted a design limitation of the
PA- 18's fuel gauges . Nevertheless, the fact remains
that the pilot failed to observe the fundame n tal check
of lifting the fuel caps to confirm the fuel contents
visually during his before-flight inspection . H ad he
done so, this accide nt would not have happened •
A viation Safety Digest 121 I 19
�Skill fatigue
Characteristics of skill fatigue
• Loss of accuracy and smoothness of control
column and rudder movements.
• Unawareness of the accumulation of rather
large errors in azimuth, elevation and attitude.
• An increase in control movements involving
greater fluctuation in order to produce the
same effect.
• Under- and over-control movements.
• Forgetting of side tasks.
• Errors of inattention. Failure to scan sky; fixed
vision.
• Preoccupation with one task component to the
exclusion of others.
'
Skill fatigue is defined as 'the deterioration in
performance cau sed by work that demands persistent
concentration and a high degree of skill '.
The dangers of this condition need to be understood
by all pilots. Although the accidents described in this
article concern very low-level helicopter operations, the
general thrust of the article applies to any pilot whose
task can at times place great demands on him . Clearly,
this encompasses the complete range of aviators, from
the RPT captain to the private pilot .
Skill fatigue is associated with failure of memory,
judgment, integrating ability and presence of mind. Its
effects may occur in conjunction with , and be
accentuated by, other fatigue-inducing factors such as
sleep loss. The phenomena were first described in a
classic series of experiments carried out in the U.K.
and published in 1948. Subjects were tested for 2-hour
spells in a simulated aircraft cockpit under blind flying
conditions during which they had to deal with a series
of manoeuvres. This was a very high workload task,
designed to demand sustained concentration and skilled
performance throughout the entire 2-hour period. In
these studies it was found that skill-fatigued subjects
accepted lower standards of performance and accuracy.
20 I Aviation Safety Digest 121
l
At the commencement of the testing sessions ' fresh '
pilots would scan and use all the instruments
systematically, but with increasing fatigue this
integrative ability failed and they would 'chase' one
instrument at a time. Memory also decreased and the
pilots would forget to monitor side instruments and
neglect to reset instruments and controls. Eighty of the
140 pilots tested forgot to lower the undercarriage for at
least one 'landing'.
Subjects in these experiments took longer to observe
and interpret instruments as th e tasks progressed.
Performance under these conditions tends to suffer
disruptions that build up in a vicious circle. Increases in
times taken to observe and interpret instruments mean
that the resulting errors tend to be greater before the
pilot takes any corrective action. When this action is
eventually taken, it m ay, so as to ·make up time lost, be
poorly controlled and thus require additional subsidiary
corrections, which in turn take up more time and
require subsequent corrective actions to be even
greater.
The characteristics of skill fatigue are listed on the
opposite page.
Research by the Bell Helicopter Company, among
others, has demonstrated significant qualitative
differences in the visual workload of pilots fl ying
helicopters at low and very low altitudes. At 500 feet,
pilots' average eye scan fixation time was 1.5 seconds,
in comparison to approximately 4 seconds at 300 feet.
Further,' at the lower altitude the pilots were operating
at their maximum visual workload capacity in just
flying the aircraft, even over fam iliar terrain*.
It must be emphasised that pilot skill level and task
workload should not be considered in isolation. The two
factors are interdependent. In other words, identical
flying tasks may represent quite different workload
levels to pilots with different individual levels of skill. In
general, the greater the level of relevant and applicable
skill of a pilot in a particular flying situation , the less is
the task workload for that pilot. Consequently, when
evaluating the level of workload for a particular pilot
involved in an accident and the possible incidence of
skill fatigue, the appropriate skill level of the pilot
related to factors such as time-on-type, currency,
experience of the specific task (e.g. night flying,
mustering), total fl ying hours, etc., must be taken into
account, remembering that certain kinds of flying
represent high workload environments for even the
most experienced and current pilots .
Research in to stressors such as skill fatigue have
typically found considerable differences in the onset and
manifestation of fatigue effects, both between pilots and
within a single pilot. Consequently, it is impossible to
provide a simple 'index' of fatigue, e.g. in terms of
hours flown . The problem is a complex multi-factored
one, but it can be dealt with. The essential point to
remember is that when the observable effects of skill
fatigue do become apparent in a pilot, these effects are
either one, or a selection , of those listed in the above
table.
Typical accidents
The effects of skill fatigue on pilot performance are
considered by research psychologists in the Bureau of
Air Safety Investigation to have been probable relevant
factors in the following accidents:
The pilot of a Bell 47 was taking a geologist and his
assistant to selected points in order to collect mineral
samples. The wind conditions were variable, but
generally northerly at about 5 knots. The temperature
• Allowing various elements of operational
sequence to appear out of place with respect to
one another.
• Easy distraction by minor discomforts, aches,
pains, noises, etc.
• Increasing unawareness of performance
deficiencies and, in extremes, signs of physical
breakdown such as fainting, cardiac
arrhythmias, etc.
• The requirement for larger than normal stimuli
for evocation of appropriate responses.
• Errors in timing.
• Overlooking of important elements in a task
senes.
was 36 degrees. The pilot had landed in a small
clearing surrounded by trees 30-35 feet tall. While
waiting for his passengers to return, he tied flagging to
the trees in order to assess the wind velocity for takeoff;
he determined the wind direction as varying from
north-west to east. He also polished the aircraft and the
rotor blades to maintain peak performance.
When the passengers returned, the pilot carried out a
careful pre-takeoff check, which included a hover to
assess surplus engine power available for takeoff. He
selected a takeoff path to the north to take advantage of
the slight headwind. The helicopter cleared the first
trees but was unable to outclimb rising terrain and
started to sink. The pilot then attempted to gain lower
ground by turning to the right but the aircraft
continued to sink, struck a small tree and then hit the
ground. The subsequent investigation established that a
more suitable takeoff direction existed towards the
south-east where the trees were not so tall and the
ground was level. Moreover, the helicopter's capability
to achieve the steep gradient was marginal and the pilot
inadvertently overpitched the main rotor.
The pilot was obviously conscientious, but he lacked
experience in helicopter operations under high ambient
air temperatures. More significant from the standpoint
of this article is the fact that he had been flying
continuously for 22 days prior to the accident. The
geosurvey work on which he was latterly engaged was
conducted at low level and involved numerous takeoffs
and landings. It is considered that the effects of
accumulated fatigue and heat stress may have led to a
deterioration in the pilot's capacity to process and
integrate the information he was receiving.
•The visual workload of the primary task of fl ying was measured in
terms of changes in pilots' ability to perform simultaneously a
secondary visual task. At m aximum visual workload on the flying
task the pilots had no 'spare capacity' to perform the secondary
visual task. In flight situations where pilots were able to perform the
secondary task to some degree, the primary flyin g task was not
occupying all their available capacity.
Consequently, pilots' performance on the secondary task was a
direct measure of the degree to which the task of flying the aircraft
was occupying their available visual workload capacity. This dual
task experimental m ethod has been used in many s tudies of pilot
workload because of the diffic ulty of measuring pilot workload levels
on the flying tasks alone.
Aviation Safety Digest 121I21
�. The seco~d accident occurred dur ing a low-level ferry
night, also in a Bell 47. Approximately 25 minutes after
takeoff, while overfl ying a Jake, the aircraft entered a
descent and struck the water in controlled Oight, slightly
nosedown and with a slight bank to the left. Shortly
after the aircraft entered the water the pilot removed his
helmet, released his harness and left the helicopter.
Pilot mishandling and mechanical failure were
discounted as factors in the accident. The pilot himself
could offer no explanation . [n his own words:
fWThe good olde days
When [ crossed the hills prior to the lake, I was about 1000
ft AMSL o r about 500 ft AGL. l wasn 't contou r nying. As I
new out over the lak e I remember sigh ting Mt X and
ch ecked that the track took me to the south -west o f Mt X
and I l?oked back in an a ttempt to sight the dam wall just
to confirm my position. The next thi ng I remember is being
1n the water.
It seems sign ificant that there was evidence that th e
pilot had been under stress from personal problems for
some days , wh ile at the time of the accident he had
been wo.rking fo r 10 Y2 hours. Although he had only
been flying for 25 minutes of this time the low-level
flight over changing terrain of hills and water wou ld
have been very demanding. In the opinion of an
aviation psychologist the pilot's action in looking back
ov~r his. left shoulder to check the dam wall and thereby
losrng his forward visual reference m ay have led to an
unperceived loss of heigh t; that is, where th e rate of
angular acceleration of the aircraft was below the
threshold level required to enable it to be detected by
the pilot's orga ns of balance. The air craft's
c~nfiguration at the point of impact (slightly nosedown ,
slight left bank) was con sistent with this low rate of
descent and the pilot's actions in the cockpi t just prior
to the accident.
Vie.w from h~licopter copkpit showing flight path and point
of impact with the water.
Comment
The intention of this art icle has been to make pilots and
s~per.'vi sor.s aware of the insidious nature and dangers
of skill fat igue. In General Aviation the onus is o n the
pilot to safeguard himself as far as possible from
vuln erable circumstances. Skill fatigue feed s on
dedication, a mbition, greed , overconfidence, pressu res
from the em ployer and customer, not knowing your
own limits an d a reluctance to say 'enough' ...
22 I Aviation Safety Digest 121
l
•
•
•
[
Prevention or remedial actions
Know what kinds of fl ying conditions for you as an
individual will constitute high workloads.
Know what the behavioural effects characteristic of
skill fatigue are (see table) an d try to be aware of them
in you rself and others so that remedial action can be
taken before it is too late. For example, if you find
yourself making m istakes in procedures , errors in
timing, taking longer than usual to carry out normal
actio ns,.overcontrolling, forgetting side tasks (e.g. ATC
~ns~uctions),. the chances arc that these symptoms may
111d1cate a .fatigue state which could become dangerous,
and cessation of nyin g for the day could save your We,
an~/or your aircr~ft. Fatigued pilots do not always have
accidents, but their chances o f doin g so are increased particularly if they have to co pe with an un foreseen
emergency .
Apart from restricting fly ing h ours, personal
discipline should include:
• A program of suitable exercise.
• R egular meals.
• Plenty of water intake to prevent dehydration (avoid
caffein e which ind uces dehydration).
• Co~trol ~f alcohol in~ake before flight and smoki ng
d urmg flight. (One cigarette raises the carbon
monoxide in the blood to a level that equates to a
state of hypoxia at 7000 feel. Two cigarettes smoked
consecutively raise the level to 10 000 feet, and these
levels are further aggravated by actual cabin
altitude .)
• Awareness that psychological and em otional
proble.ms are an insidious drain on energy reserves,
a particularly important consider ation in very high
workload flying operations •
The following monthly summary of acciden ts was
taken from the December 1917 records of the Royal
Flying Corps.
5.
Avoidable accidents
6.
There were six avoidable accidents:
1. T he p ilot of a Shorthorn, with over seven hours
experience, seriously damaged the undercarriage
on land ing. H e had failed to land at as fas t a
speed as possible, as recommended in the
Aviation Pocket H andbook.
2 . A BE2 stalled a nd crashed during an a rtillery
exercise. The p ilot had been struck on the head
by the semaphore of his obse rver who was
signalling to the gunners.
3. Another pilot in a BE2 failed to get airborne. By
error o f judgment he was attempting to fly a t
mid-day instead of during the recommended b est
lift periods, i.e . just after dawn and just before
sunset .
4. A Longhorn pilot lost control and crashed in a
bog near Chipping Sodbury. An error of skill on
the part of the pilot in not being able to con trol
a mach ine with a wide speed band of 10 mph
between top speed and stalling speed.
Whilst low fl ying in a Shorthorn the pilot
crashed into th e top d eck of a horse-drawn bus,
near Stonehenge .
A BE2 pilot was seen to be a ttempting a banked
turn at a constant heigh t before he crashed . A
grave error by an experien ced pilot .
Unavoidable accidents
There were 29 unavoidable accidents .
1. The top wing of a C a mel fell off due to fa tigue
failure of the nying wires . A successful
emergency landing was carri ed ou t.
2. 16 BE2s and nine Shorthorns had complete
engine failures. A ma rked im provement over
November's figures.
3 . Pigeons destroyed a Camel and two Longhorns
after mid-air strikes.
Cost of accidents
Accidents durin g the last three months o f 1917 cost
£317-10-6: money do wn the drain a nd sufficien t to
bu y new gaiters and spurs fo r each a nd every pilot and
observer in the Service •
Aviation Safety Digest 121 I 23
�
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llsk first. for safety~ sake.
BUREAU OF AIR SAFETY INVESTIGATION
120/1984
�Contents
(!lll'fJ()
Some things were never meant to fly
3
6
Dangerous cargo
More on P·charts
We wish to reinforce the message that P-charts must
be consu lted whenever doubt exists about an aircraft's
capability to operate into or from a particular strip.
8
Unauthorised Night VMC flight
Four lives were lost when a private pilot without any
class of instrument rating attempted a Night VMC flight
from Leigh Creek to Alice Springs.
11
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to
Australian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Australian civil aviation.
Unnecessary low-level transit= disaster
A pilot experienced engine failure while cruising at
100 feet AGL; there was insufficient height to effect a
safe forced landing and the aircraft coll ided with a tree.
An intense fire consumed much of the wreckage and
killed the pilot.
12 Water contamination of fuel systems
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the free list experiencing problems with distribu·
tion or wishing to notify a change of address should write to:
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 1839Q, Melbourne, Vic. 3001.
Aviation Safety Digest Is also available on subscription fro m
the Australian Government Publishing Service. Inquiries and
notifications of change of address should be directed to:
13 The dangers of distraction
Two more accident summaries show the need for
continuous vigilance and concentration during aerial
application operations.
14 Stress, fatigue and piloting
Mail Order Sales,
Australian Govern ment Publishing Service,
G.P.O. Box 84, Canberra, ACT 2601
Subscriptions may also be lodged wi th AGPS Bookshop s in all
capital cities.
16 Trapped on top
Th e amount of c loud predicted in a meteorological
forecast is an important item for consideration in
preflight planning.
18 Birdstrikes 21
reducing the risk
Inadequate periodic inspections
The starboard main wheel jammed during lowering of
the landing gear in a Piper PA31 Navajo. A forward
hinge on the inner gear door had broken near the
centre of the arm: it was apparent that Inspection
requirements had not been fulfilled.
22 The importance of preflights
(reader contribution)
Reader contributions and correspondence on articles should
be addressed to:
The Director,
Bureau of Air Safety Investigation,
P.O. Box 367,
Canberra City, ACT 2601.
© Commonwealth of Aus tralia 1984
ISSN 0045·1207
R83/566 Cat. No. 83 1832 4
Printed by Ambassador Press Pty. Ltd.
51 Good Street, Granville, N.S. W. 2142.
The Australia n Government fears there cou ld be a
disastrous aviation accident in this country unless
people become more aware about the restrictions and
preca utions needed befo re taking or sending da ngerous
goods on to aircraft.
Every day thousands of dan gerous goods are sent
around the world by air. When packed and handled
correctly, they are perfectly safe. H owever, when
exposed to the en vironment of air tran sport they can, if
not properly packed and ha ndled , become as dangerous
as a h ijacker's bomb.
SOME THINGS WERE NEVER MEANT TO
FLY - that's the message the Department of Aviation
is giving to people wanting to take or send potentially
dangerous goods on board an aircraft.
They are being urged to ASK FI RST - FO R
SAFETY' S SAKE if they are not sure about what they
can or can 't ta ke on an aircraft.
Accidents and incidents
Listed below are some dangerous cargo occurren ces
repo rted in Australia an d overseas in recen t years.
From the U.K.
• A su itcase filled with toilet articles (hair sprays,
deodorants, fingernail polish remover an d medicinal
alcohol) and loose book m atch es exploded when
dropped by a baggage h a ndler.
• A smoking suitcase with a broken gallon glass j ug of
nitric acid was pulled off an aircraft j ust befo re the
baggage caught fire.
• T he cork came off a bottle of acid in a repair kit
checked as passenger baggage, and caused
considerable da mage to the aircr aft.
• A passenger insisted on hold ing his briefcase in his
lap. When the flight attendant tried to stow the bag
u nder th e seat, the passenger resisted. It transpired
that the case contained six quart-bottles of sulphuric
acid .
• A baggage ha ndler was cu t by flying fragments and
one of h is eardrums was injured when 10 practice
hand grenades, five firecrackers and a smoke bo mb
packed in a coffee can in a passenger's bag exploded.
• Wh ile luggage was being loaded into an aircraft,
ground per sonnel noted a fuse-type powder sm ell
and sm oke coming from one of the bags. Two of
91 books of m atches had ignited.
In Au stralia
• A baggage handler who was loading passenger
lu ggage into the car go compartment of a Boeing 727
at Da rwin noticed sm oke coming fro m a b riefcase.
T he case was removed from the aircraft, and
exa minatio n revealed that a book of matches had
ign ited and burnt some adjacent papers.
• Aboard a Fokke r F27 en route from Townsville to
H ughenden a passenger was carrying a bottle of
2 '; Aviation Safety Digest 720
ammonia in her hand luggage. T he ammon ia spilt in
the passenger cabin. Becau se of the fumes, the crew
went on to oxygen and the aircraft returned to
Townsville.
• During turnaround of a Douglas DC9 at Townsville
Airport, a pungent smell was noticed in the rear
cargo locker. Subsequent unloading revealed a
damaged ca n of methyl ethyl ketone. In addition, a
R amset container was fou n d holding 700 rounds of
explosive charges. Two tradesm en on the aircraft
had spoken to the operator about the carriage of the
R amset gun but had not mentioned the charges.
• Before boarding a Fokker F27, a passenger checkedin five pieces of luggage, including two cardboard
cartons. H e did not indicate that the cartons
contain ed hydrochloric acid. As the cartons were
travellin g along the baggage con veyor belt, one
tumbled down the 45-degree slope. It was removed
from the belt and placed on a trolley. Because of the
odour coming from the carton and the violent
reaction of some spilled fluid on the trolley, ground
staff investigated further and found that the carton
contained acid.
Papua N ew Guinea
• A box marked as containing laboratory equipmen t
burst into flames during transh ipment at P ort
Moresby airport and could not be extinguished. It
had arrived aboard a passenger aircraft. A
su bsequent investigation revealed that the box
contained a variety of chemicals, including n itric
acid.
U .S.A.
• Perhaps the worst aircraft accident attributed to
dangerous cargo was in 1973 when the three-man
crew of a Pan American Boeing 707 freighter was
killed when the aircraft crashed near Boston while
trying to make an emergency landing. Investigators
fou nd that the crew had been overcome by fumes
from a cargo of incorrectly packed n itric acid, which
had leaked and reacted with the sawdust in which it
was packed.
The possibility always exists that worse accidents, for
wh ich it was not possible to determin e a reason , may
have been caused by dangerous cargo .
Dangerous goods
Below are some things FOR BIDDEN in hand luggage
or luggage destined for th e hold of an aircraft.
• EXPLOSIV ES: fireworks, flares, toy gun caps.
• C OMPRESSED GASES : gas cylinders, and aerosols
other than limited quantities of medicinal and
toiletry articles which are necessary for the journey.
• FLAMMABLE LIQUIDS AND SOLIDS : lighter
fuel, matches, pain ts, thinners, fi re lighters, cigarette
Aviation Safety Digest 720 I 3
�lighters containing unabsorbed lighter fuel.
• OXIDISERS: some bleaching powders and certain
acids.
• ORGANIC PEROXIDES: such as hair or textile
dyes, disinfectants, fi breglass repair kits and certain
adhesives.
• POISONS: arsenic, cyanide, weedkillers.
• IRRITATING MATERIALS: tear gas devices.
• INFECTIOUS SUBSTANCES: live virus materials,
pathological samples.
• RADIOACTIVE MATERIALS: medical or
research samples which contain r adioactive sources.
• CORROSIVES: acids, alkalis, wet cell-type car
batteries, caustic soda, mercury.
• MAGNETISED MATERIALS: magnetrons,
instruments containing magnets.
• OTHER DANGEROUS GOODS: dry ice, oilimpregnated rags.
All of these goods can be shipp ed as cargo if properly
packed and declared . People are advised to contact their
airline for more information.
Below is a list of items passengers CAN take on an
aircraft:
• alcoholic beverages, perfumes and colognes
• limited quantities of medicinal or toiletry products
such as h air sprays for personal use
• with the approval of the airline: small oxygen
cylinders for medical use and small carbon dioxide
gas cylinders worn to power mechanical limbs
• safety matches and certain lighters carried on the
person: they must not be packed in luggage.
Why some goods are dangerous
GAS C IGARETTE LIGHTERS. Ligh ters containing
liquefied gas under pressure may be hazardous when
operated under the reduced a tmospheric pressures
experienced in an aircraft cabin during flight. The
popular plastic disposable lighters are not fitted with a
means of protecting the gas release valve against
,,
inadvertent operation. Such operation of a disposable
lighter in baggage could release the entire contents into
an aircraft baggage compartment. These lighters
contain sufficient gas to cause a powerful explosion.
LIGHTER FLUID is a highly volatile and
flammable liquid which can produce an explosive
concentration of vapour in an enclosed space. Cigarette
ligh ters containing unabsorbed liquid fuel may leak
under the conditions of air transport, producing
explosive vapour in aircraft baggage com partments and
cabins.
BOOK MATCHES can easily have the protective
flap dislodged when moved about in luggage. There
have been several incidents where the flap has been
dislodged and a fire started when match heads rubbed
against the striking surface of another book of matches.
AMMUNITION. This includes all kinds of bombs,
grenades, rockets, projectiles or other devices
containing incendiary, smoke, tear-producing or toxic
agents. These contain either an explosive-igniting
device, a burster, an expelling charge or a prop ellent
charge . Ammunition presents a risk of a fire and/or an
explosion as well as the p ossib ility of tear-producing
gases, poisonous gases, smoke or a projection hazard.
For th ese reasons, most types of ammunition are
forbidden on passenger and cargo aircr aft. The
R amset-type charges used in the building industry are
classified as an explosive . However, when packed in
accordance with regulations, these goods are considered
safe and limited amounts may be transported by air.
SOL VENTS AND ADHESIVES. Adhesives often
contain solvents such as acetone, methanol, methyl
ethyl ketone (MEK) and acrylonitrile, which are very
fla mmable and in some cases, such as methanol and
acrylonitrile, toxic. Acrylonitrile when h eated emits
highly toxic cyanide fumes . Therefore, if a spillage or a
leakage of adhesive or solvents occurs, there is a risk of
a fire hazard and, depending on the type of solvent or
adhesive , there may also be a toxicity hazard.
EASILY VAPORISED LIQUIDS. T h ese liquids are
mainly solvents, such as methylated spirits, petrol,
naphtha, ether, etc., which are highly flammable . They
are also very volatile, emitting flammable fumes.
A r isk of a fire or explosion will result if a leakage
occurs. Therefore, the packaging used for such volatile
liquids must be capable of withstanding the in ternal
pressures encountered when these liquids are
transported by air .
WET CELL BATTERIES. These consist of metal
plates immersed in an electrolyte liquid, either a dilute
sulphuric acid or potassium h ydroxide. Both of these
electrolytes a re corrosive liquids. These batteries could
cause damage either through spillage or accidental
short-circuiting of th e terminals, which could result in a
fire.
There have been many occurrences where battery
acid has leaked, causing damage to both the aircraft
structure and adjacent baggage.
MERCURY is a metal which remains in liquid form
at temperatures as low as - 38 °C . It gives off toxic
fumes at high temperatures and low pressures. L iquid
mercury will very quickly penetrate aluminium and
cause it to become brittle and weak. As most aircr aft
parts are produced from aluminium, it can cause severe
structu ral damage if spilt in an aircraft, especially as it
is difficult to trace and remove.
explosion. When heated, the majority of acids will
produce very toxic fumes. Unless properly packed and
very carefully handled, they are a source of potential
danger.
AEROSOL CANS. In aircraft, decreased cabin
pressure may result either in leaks if the can i~ not
properly sealed or in the contents being expelled at a
much greater rate than normal when used. They are
also very susceptible to heat, and there have been
incidents where cans have exploded as a result of
becoming overheated in an aircraft cabin.
PAINTS. Classified as paints are enamels, lacquers,
stains, shellac, varnish, polish, filters and thinners.
These all con tain solven ts which are highly flammable.
Unless the container is tightly and effectively sealed
and packed , the reduced air pressure in a n aircraft hold
could cause the tin to pop open and the contents to
spill. There have been numerous incidents where cans
of paint have opened and spilt, not only damaging
other goods and the aircraft but also, in some cases,
producing explosive vapour in the aircraft hold.
PETROL is a highly flammable liquid which
incr eases in volatility at low pressures and/or h igh
temperatures. It must therefore be stored or packed in
approved containers and should have sufficient room
for expansion to ensure that no leakage or distortion
occurs to the con tainer. A hazardous situ ation will
occur if the seal leaks, allowing fu mes to escape and
produce an explosive mixture.
HOUSEHOLD C LEANERS . Cleaners such as
detergents, stain removers, bleaches, etc., can contain
either chlorides o r ammonias. Many bleaching powders
contain strong oxidisers, which react with other
materials producing fumes, smoke and fire. Some
detergen ts and stain removers contain ammonia, which
is very corrosive and reacts with oxidising materials.
Ammonia also produces toxic fumes . There have been
instances where aircraft have had to return to an
airport du e to am mon ia fumes affecting the p ilot and
passengers.
ACIDS present a number of hazards depending on
the particular type. In general they are corrosive and
will a ttack most types of metal alloys and materials used
in aircraft. T hey can also cause very severe burns when
in contact with the skin. Some acids such as nitric and
perchlor ic are strong oxidisers. If spilt, they could
combine with other substances and create a fire or an
Legislation and penalties
Carriage of dangerous goods by air is governed by the
Air Navigation Regulations (ANRs). ANR 120 states
that dangerous goods shall not be consigned or carried
except with permission of the Secretary of the
Department and in accordance with conditions set out
in that permission. The conditions are set out in Part
33 of the Air Navigation Orders (ANOs). Part 33 is
being revised to conform with· the requ irements set
down by the International Civil Aviation Organisation
(ICAO).
In Australia, monetary penalties for breaches of the
Air Navigation Regulations, including improperly
consigning or taking dangerous goods on to an aircraft
or falsely declaring them, were increased recently to a
maximum of $5000. A gaol sentence of up to two years
may be imposed on individuals as an alternative or
additional penalty.
Section 18 of the Crimes (Aircraft) Act deals with
taking or sending dangerous goods on an aircraft. The
penalty which exists for individuals breaching this Act is
a gaol sentence of seven years . Until recently there was
no provision for a monetary penalty for either
individuals or for bodies corporate illegally consigning
such goods. The Act has been amended to correct this
deficiency and monetary penalties of up to $20 OOO for
individuals and $100 OOO for bodies corporate are now
available.
Airlines are stepping up their security checks on
passengers' hand luggage and widespread publicity is
planned when people are prosecuted.
The airlines have highly trained cargo acceptance
staff to assist people who need advice and information
on shipping dangerous goods. Staff are also required by
law to reject any item incorrectly prepared or
consigned. In some cases, they are also required to
report these occurrences to the Department of Aviation.
If the investigation into such an occurrence reveals a
deliberate attempt to circumvent the regulations and
procedures, the Department will prosecute the offending
person or company. Successful prosecutions have been
made in the past and it is expected that the recent
penalty increases will help to deter the few 'rogues ' in
the cargo business.
Conclusion
The hazards of incorrectly packing or consigning
dangerous goods are so ext reme and obvious that it is
difficult to believe that any individual associated with
the aviation industry would do so deliberately. Anyon e
who has any doubts regarding the safety of air cargo
should always check to ensure that all safety regulations
have been met before that cargo is despatched or
accepted for carriage •
Aviation Safety Digest 120 I 5
4 I Aviation Safety Digest 120
�More on P-charts
The importance of using the performance charts
contained in each GA aircraft's Approved Flight
Manual was emphasised in a feature article in
Aviation Safety Digest 118/ 1983. That article stressed
the point that P-charts are the only authorised
source of takeoff and landing data, and that they
must be consulted on any occasion the slightest
doubt exists about an aircraft's capability of
operating into or from any strip.
The accident described below is unforlunately typical
of many in GA operations, in that the strip the pilot
tried to use simply was not long enough.
The accident
A property owner wanting to conduct an aerial
inspection of his land arranged for a friend who was a
pilot to do the job in a Cessna 172. Before flying out to
the property , the pilot told the owner thal he would
need an airstrip about 700 metres long and a means of
determining the wind velocity . The owner said he
would attend to those requirements and on arrival the
Cessna landed uneventfully in the designated area.
Before taking off for the inspection, the pilot was
driven along the strip by the owner and, using lhe car's
speedometer, measured its length as 400 metres. By
'eyeballing' the strip, the pilot estimaled that this
distance was about the same as his home field and
therefore decided that a takeoff with himself and three
passengers would not present any performance
problems. This belief was reinforced by the fact that he
had used only half of the strip for landing.
The passengers were embarked and, on completion of
an engine runup, the aircraft was taxied lo the takeoff
threshold. After lining up, full power was applied while
the aircraft was held on the brakes. Ten degrees of flap
were selected.
Subsequently the pilot recalled that, during the
takeoff roll, acceleration to 50 knots seemed normal but
then became very slow. He therefore lifted the aircraft
off the ground at 50 knots as he felt the strip might be a
bit soft. His intention was to accelerate close to the
ground and, when the airspeed had increased
sufficiently 1 pull up to clear two trees at the end of the
strip. The technique of holding the aircraft close to the
ground was consistent with the Flight Manual which
states that 'the aircraft is held on or close to the ground
until takeoff safety speed is achieved' (which in this case
was 62 knots).
Just after the pilot pulled up and passed the trees the
aircraft' s right wing suddenly dropped about 15
degrees. The pilot later commented that he was able to
pick up the wing with aileron but could not prevent the
Cessna from 'flying into the ground' and striking a
dam revetment.
Investigation
The Cessna's acceleration during the takeoff roll had in
fact been normal and it soon became apparent that the
faulty component was human , not mechanical: the
accident occurred because the pilot had failed to
maintain flying speed during his efforts lo get airborne
6 I Aviation Safety Digest 120
from a short strip.
It was established that the pilot had received more
than adequate instruction on ALA operations and the
use of performance charts during his basic training and
subsequent licence testing. However, since then he had,
for no good reason , become reluctanl to use P -charts.
Thus, even though he had taken lhe trouble to measure
this su·ip, he effectively discounted that measurement
by making an 'eyeball ' assessment that the strip was the
same length as one he used frequently, and therefore
would be suitable.
Had the pilot been in the habit of referring to his
P-charts, he would have known - even wi thout
making a precise calculation - that 400 metres was
totally inadequate.
In this particular instance, the Takeoff Distance
Available (TODA) of the strip was further reduced
from 400 metres to 315 melres because of the climb-out
gradient requirements to clear the two trees. Prevailing
conditions were as follows:
'
•
•
•
•
•
•
temperature . . . . . . . . . . . . .
strip pressure height . . . . . .
strip surface . . . . . . . . . . . . .
strip slope . . . . . . . . . . . . . . .
aircraft weight . . . . . . . . . . .
wind velocity . . . . . . . . . . . .
29 °C
600 feet AMSL
short dry grass
up 1 per cent
1043 kg
5 knots headwind
SLOPE- PERCENT
UP
NO TE
1600
1400
1100 l.44-...,4:~C;-4'7=-7!i'
THE GROSS WEIGHT AT TAKE- OFF
SHALL NOT EXCEED THE LESSER
OF (A) OR (B) .
11 00 i..<-.,t...1..f..-#!:...J<.-..,t....,,4.-,'--,lrl----7"4
DEPARTMENT OF CIVIL AVIATION
TAKE -OFF WEIGHT CHART
CESSNA 172M
0 L:t:::I:::±~~~
10000 8000 6000 4000 2000
DENSITY HEIGHT- FT
POWER TO
BE USED
RPM
MAN.PRESS.
SEE PARA. 1.1
FULL THROTILE
I
Entering the Cessna 172 Takeoff Weight Chart
(opposite) with those figures, lhe takeoff d istance
required can be seen to be just under 800 metres.
It should be noted that the Takeoff Weight Chart for
the 172 is based on a flap setting of 0 degrees: there is
no P-chart for 10 degrees. This is not, however, a
problem. In the manufacturer's Pilot's Operating
Handbook, pilots are advised that, while normal and
obstacle clearance takeoffs are performed with the wing
flaps up, the use of 10 degrees of flap can be helpful on
short, soft or rough strips as it will shorten the ground
run by about 10 per cent. The Handbook goes on to
point out that the use of 10 degrees of flap will,
however, result in a degraded climb performance for
clearing a 50-foot obstacle.
In this case the trees the pilot wanted to clear were
only 15 feet high, so his decision to select 10 degrees of
flap was reasonable. The important point, though, is
that even when the 10 per cent reduction of aircraft
ground run is applied, he still needed a total takeoff
distance in excess of 700 metres - more than twice
that which was available.
As a secondary point, the accident also illustrated the
danger of assessing or comparing strip lengths by
'eyeballing' them.
Comment
If this pilot had used his P-charts and heeded their
information, he would not have jeopardised the lives of
himself and his passengers; nor would he have caused
substantial damage to a valuable aircraft.
Contrary to the beliefs of a minority of pilots,
P -charts are neither complicated nor difficult to use. In
this example, the information required is the distance
the aircraft needs to takeoff. To find the distance, it is
simply a matter of entering one side of the charts with
airfield pressure height and the other side with takeoff
weight, and following the self-explanatory graphs
through the other variables shown as sloped line3
(temperature, wind, slope a nd surface) until the two
lines intersect. Most calculations are even simpler than
that, as strip length is usually known , in which case the
graphs are entered at the airfield pressure height and
followed through to find the maximum permissible
takeoff weight for the given conditions of temperature,
strip le ngth, strip surface, strip slope and wind
component.
Too many avoidable accidents - many of which
cause fatal or serious injuries - continue to be
attributa ble to pilots' failure to use P-charts. The
remedy is simple and within the control of every
pilot •
Aviation Safety Digest 120 I 7
�Unauthorised Night VMC flight
A pilot holding a private licence without any class of
instrument rating was asked to fly three people on a
fishing trip from Swan Hill in Victoria to the Northern
Territory. The passengers planned to stop at Alice
Springs on the northbound flight to attend the H enleyon-Todd Regatta. A Piper PA32-260 was hired for the
trip.
The pilot lived in Melbourne and on the day of
departure arrived at Moorabbin Briefing Office at
about 0830 Eastern Standard Time (EST). Weather
conditions to the north were unsuitable for Visual
Meteorological Conditions (VMC) flight so he took the
Cherokee on a brief local sortie. By 1100 hours the
weather to the west of Moorabbin had improved so the
pilot decided to depart in that direction and
circumnavigate the poor conditions which still existed
on the direct track to Swan Hill. He prepared and
submitted a flight plan covering all stages of the journey
to Alice Springs, operating under the Visual Flight
Rules (VFR). Although forecasts of en route winds
were available, the pilot chose to plan for nil wind
conditions.
When the flight plan was submitted, it was noted by
the Briefing Officer that the estimated flight time was
9 hours 42 minutes and the journey would therefore
extend beyond the end of daylight. When this was
pointed out to the pilot, he stated that the final part of
the journey would be completed under Night VMC
procedures. The Briefing Officer reminded the pilot
that he would need to check the latest weather forecasts
at Leigh Creek to ensure that conditions were suitable
for this type of operation.
The Cherokee departed Moorabbin at 1134 hours
EST and arrived at Swan Hill at 1411. After refuelling
a nd embarking the three passengers and their baggage,
it departed at 1447 hours and arrived uneventfully a t
Leigh Creek at 1819 hours (1749 hours Central
Standard Time). The aircraft was again refuelled and
the pilot attended the Flight Service Unit (FSU) where
he was given copies of the latest weather forecasts. H e
was observed making a number of calculations, but he
did not notify the FSU of any amendments to his
original flight plan.
The forecasts provided to the pilot indicated that the
wind at the planned cruising altitude of 8500 feet was
from the west at 15 to 20 knots. No cloud was predicted
for the p art of the route south of Oodnadatta but
increasing altocumultis and altostratus, base 12 OOO
feet, was forecast for the latter part of the journey.
Departure from Leigh Creek was made at 1824 hours
(NB: all times are now given in CST), which was about
the same time as the end of daylight. The planned
route and estimated time intervals were: Lake Eyre
North 53 minutes, Oodnadatta 59 minutes, Finke
60 minutes and Alice Springs 54 minutes.
In accordance with this schedule, the p ilot reported to
Leigh Creek that he had reached Lake Eyre North at
1917 hours, was cruising at 8500 feet and was
estima ting Oodnadatta at 2016 hours. Subsequently,
when in radio contact with Alice Springs, he amended
his estimate for Oodnadatta first to 2020 hours and
8 I Aviation Safety Digest 120
later to 2024 hours. At 2023 the pilot reported his
position as Oodnadatta at 2024, cruising at 8500 feet
and estimating Finke at 2124 hours. At 2059 he advisee!
that he was now cruising at 7500 feet. Then, at
2124 hours, he reported h e was at Finke at 2126,
cruising 7500 feet and estimating Alice Springs at
2220 hours.
Five minutes later the pilot called Alice Springs and
asked for radar guidance. He was informed that Alice
Springs was not equipped with radar and, when asked
if he required navigational assistance, replied
'affirmative'. The Uncertainty Phase of Search and
Rescue procedures was implemented by air traffic
control.
Radio communications with the Cherokee were
intermittent and messages were being relayed through
other traffic. The pilot was asked to climb to 10 OOO
feet in an attempt to improve R/T and navaid reception
from Alice Springs. Communications did improve, and
Alice Springs ascertained from the pilot that:
• his last positive visual fix had been at Oodnadatta;
• he had maintained a heading of 335 degrees
magnetic since that position; and
• his true airspeed was 120 knots.
As the aircraft was equipped with VOR and ADF the
pilot was asked if he was receiving the Alice Springs
facilities. He advised th at he was not receiving the
VOR but that he could hear the Alice Springs
automatic terminal information service on the ADF. At
2145 hours the pilot stated that his remaining fuel
endurance was 90 minutes.
From the information provided by the pilot and the
forecast winds, it was calculated that the Cherokee was
east of track. The pilot was therefore instructed to steer
a heading of 320 degrees magnetic. At 2150 hours he
reported that the ADF was indicating 030 degrees, but
he could not see any lights or ground features. At 2157
hours the pilot was instructed to steer a heading of 300
degrees magnetic, in the hope that he would come
within range of the Alice Springs VOR station. Three
minutes later he advised that his VOR equipment was
receiving Alice Springs and he was on the 320 radial.
A s this indicated that the aircraft was northwest of Alice
Springs, the pilot was asked to confirm that his
equipment indicated 320 'to' and not 320 ' from' the
station. No reply was received to either this or
subsequent repeated calls.
SAR procedures were upgraded to the Distress Phase
and an extensive air and ground search initiated. The
Cherokee was not equipped with an emergency locator
beacon and it took about 36 hours to locate the
wreckage, which was 29 nm east of the planned and
reported position. There were no survivor s.
Parts of the aircraft were spread over a considerable
area. A trajectory analysis of the various components
revealed that the aircraft had broken apart while
h eading 050 degrees magnetic, in a steep dive of at
least 46 degrees, and within the altitude range of
2750-3850 feet. Examination of the wreckage found no
evidence of pre-existing defects. The left wing, both left
and right stabilators, and the rudder and fin had
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Aviation Safety Digest 120 I 9
�separated from the aircraft as a result of overload forces
in excess of the design strength of the aircraft.
Perman en t torsional deformation of both stabilators
indicated the aircraft speed was in excess of 204 knots
prior to break-u p. T her e was evidence that the e ngine
h ad been operating and the aircraft's electrical system
had been powered at the time the fuselage struck the
ground.
Analysis
Although the flight from Leigh C reek was conducted at
night, the pilot did not hold a N ight VMC or a ny other
class of instrument rating. His logbook recorded only
1. 5 hours of n ight fl ying experience, gained fi ve yea rs
previously during training fo r his pr ivate pilot licen ce.
H owever , documents recovered from the wreckage
showed that he had m ade travel fligh ts at ni ght on other
occasions, the m ost recent being on e m onth before the
fatal accident.
By applying ' hindcast ' winds (i.e. winds based on
aircraft repo rts a nd recorded meteorological data fo r the
particular area an d time) a nd th e C herokee's true
airspeed to th e most proba ble flight path from Leigh
C reek to th e accident site, investigators determined that
it was highly improbable that the aircraft had been at
Lake Eyre North , Oodn adatta a n d Finke at the
reported times . H owever, even allowing fo r these
calculation s, the investigators ini tially fou nd tha t there
were ab out 15 m inutes of flight for which they could
not account. It was here that a witne.ss report cam e to
the fo re. A stock.man camped in the Mt.Robinson/
YouJtan gunna Hill area reported h aving heard the
engine noise, a nd seen the lights, of what appeared to
be a light aircraft, circl ing in the area for about 15
minutes between 2000 a nd 2100 hours. This was
con sisten t with the fligh t pa th recon structed by
investigator s a nd explained the ' missing' 15 minutes.
Given the known and post ula ted fligh t data, it seems
p robable that, notwithsta nding his position reports for
Lake Eyre North , Oodnadatta and Finke, the pilot
started experiencing navigation al difficulties soon after
his depar tu re from L eigh Creek . By th e time he
reached the M t Robinson/Youltangun na Hill area, he
was so con cerned that he spen t a considerable t ime
circling, search ing for an identifiable land m ark. His
final position report at Finke - which was followed
only fi ve minu tes later by a request for radar assistance
- was obviously little more than a guess, a nd not a
ver y well in formed guess at that.
Comment
The cause of the accident was found to be that
fo llowing a loss of control, the aircr aft was subjected to
aerodyn a mic loads in excess of its design li m it. Wh ile
the reason for the loss of control could not be
determined with complete certainty, several probable
factors were apparent.
First, by the time of the acciden t, the pilot had been
on d uty fo r about 14 hours, and out of bed for
considerably longer; thus, he would have been fatigued
to some extent. Second, the fi nal stages of the fl ight
were conducted under a complete overcast, be neath
which it was very dark with no visible horizon . The
fatigue a nd absence of an horizon would have increased
the pilot's susceptibility to spatial disorientation.
Finally, and most significantly, there is the matter of
a pilot without a C lass Four rating attempting a Night
VMC flight.
T he aeronaut ical experien ce and flight proficiency
requisites for a Class Four rating are exh a u stive and
demanding. For example, included am ong the many
requ irem en ts Class Four aspirants m ust satisfy are
those of completing 10 hours of night flying, of wh ich
at least five must be visual navigation; <!nd a
demonstration o f proficiency in recovering from
un u~ual attitudes solely by reference to instruments (full
details of all requirements are listed in ANOs). It is
axiom a tic that all of the sequences a pilot m ust
complete for the ratin g arc essential, and a re designed
to equip an indiv id ual to deal with the considerable and
varied situation s and pressures which can arise during
N ight VMC flight.
Apparently the pilot involved her e had flown at night
previously without undertaking any formal Class Four
train ing. Regrettably, it needs to be said tha t he was
foolhardy in the extreme to do so. On this fl igh t, when
pressures started to build up on him, he simply did not
have th e training, knowledge or relevant experience to
cope.
T he investigation report concluded that the reason
for the loss of control could not be determined.
However , the report went on to state that, together
with fatigue and the prolonged stress arising from
navigat ion al difficulties, the pilot's lack of training a nd
experien ce at maintaining control in the absence of
external visual references was probably a contributory
factor •
Unnecessary low level transit
=disaster
Aerial application flying is recognised as a high-risk
o~eration. It was because of this that Aviation Safety
Digest 11 4 featured a special article titled 'Wire strikes:
th e threat and the defence' which addressed dangers
faced by agricultural pilots.
Among the matters discussed in the article was that
of transit heights wh ile flying en route to or from an
application area. It was pointed out that wire strikes are
common on transit fl ights, and that pilots should avoid
exposing themselves to this totally unnecessary risk by
cruising at a comfortable height as 'hedgehopping back
to the strip achieves negligible time saving and
markedly increases fatigue and exposure to wire
str ikes ' .
T he risks inherent in needless low level cruises are
not restricted to wire strikes. Should an aircraft sustain
a malfunction precipitating a forced landing, then
obviously the aircraft's height AGL is going to be a
crucial factor in th e execution of that landing. As an old
saying goes, 'Altitude above you is like runway behind
you'. It is a maxim wh ich has relevance to all pilots,
but especially those of single-engine aircraft; and it was
unhapp ily illustrated in the following fatal accident.
*
*
*
An agricultural aircr aft took off in the late afternoon to
carry out some sowing on a property about 17
kilometres from the airstrip. After turning on to
heading the pilot settled into the cruise at a height of
about 100 feet AGL, although there was no operational
n ecessity to maintain such a low level. At a position
about three ki lometres north of the airstrip the noise of
th e engine suddenly ceased. The aircraft descended a nd
banked steeply to the right. While still turning, the
ri?ht ":ing collided with a large willow tree. The ri ght
wmg tip then struck the ground and the aircraft
cartwheeled before coming to rest 58 metres further on.
An intense fire consumed much of the wreckage and
killed the pilot.
In brief
Shortly after liftoff the left en gine on an America n
D C-9 lost power a nd th ere were twelve to thirteen
rapid compressor stalls. T hou gh the computed
en gine p ressure ratio (EPR ) settings for takeoff were
1. 94 , the crew noted tha t EPR had d ropped to 1. 22
at this point. The aircraft sank back on to the
gro und , with the ta il strik ing the d ir t adjacent to the
edge of the ru nway because of d irectional control
difficulties.
To initiate this takeoff, the crew had take n the
10 I A viation Saf ety Digest 120
aircraft back beh ind a displaced threshold to make
use of all available runway. They were cleared for
takeoff just as a heavy L-1011 exited the runway
after an a utoland. In reconstructing the incident, it
was determined th a t th e DC-9's rotation and liftoff
occu rr ed at a point on the runway j ust prior to the
heavy j et 's touchdown point, leading to the
conclusion that wake vortices proba bly cau sed the
repeated compressor stalls, power loss an d temporary
loss of directional control •
*
*
*
Because of the fire damage, it was not possible to
determine the cause of the apparent engine failure. It
was found that the aircraft was illegally fitted with both
liquid-spraying and solid-spreading equipment (only
one should be fitted at any time) which would have
sign ifican tly affected glide performance .
H owever, notwithstanding the loss of engine power
and the illegal equipment configuration, the low cruise
height was identified as being a crucial factor in the
catastrophic outcome of this accident. Based on the
position , heading and height of the aircraft at the time
of the apparent engine failure, the most suitable forced
landing area was located ahead and to the right. It
seems probable that the pilot was attempting to reach
this area when the collision with the tree occurred. T he
collision was a consequence of the pilot not having time
for any course of action other than that which
immediately presented itself: unless he happened to be
virtually on top of a clear area, he simply did not have
sufficient height to effect a safe forced landing.
Com ment
The extent to which light aircraft are damaged during
forced landings varies considerably. It is, however, a
fact that the great majority of pilots and passengers
involved in such accidents survive them, often with
lit tle , if any, injury.
One of the key factors is that of having sufficient
time - which clearly is related to sufficient altitude to assess the situation and exercise as much control as
possible over the forced landing. If you can pick the
place, the landing direction, control the airspeed ,
complete safety checks, etc., then the odds are very
much in your favour. On the other hand, needlessl y
cruising at a low altitude stacks the odds against you to
the extent where lives may be placed at risk •
Aviation Safety Digest 120 / 11
�llla,,r 111,a•ina,ien el ''''
.,.~,··
Aircraft accident reports
FOURTH QU ARTER 1983
Accidents caused by water contamination in fuel systems continue to occur to General Aviation
aircraft. Most are .associated with high-wing aircraft fitted with bladder-type fuel cell- -lthough the
problem is
no i
su
pe~ .
....,.._
Prepared by the Bureau of Air Safety Investigation
The foll ow ing information has been extracted f rom acc ident data f iles mai ntai ned by the Bureau o f
Air Safety Investi gation. The i ntent of publish ing th ese reports is to make avai lable information on
Aus trali an ai rcraft acc idents from whi ch t he reader can gain an awareness of t he c irc umstances and
cond it ions which led to the occ urrence.
At t he time of publicat ion man y of t he acc iden ts are sti ll under in vest igation and the informatio n
contained in those reports must be considered as prelim inary in nat ure and possibly subject to
amend ment w hen t he investigation is f inali sed .
Readers shou ld note that t he i nformation is provided to promote avi ation safety - in no case is it
intended to imp ly blame or l iability.
Note 1: Al I dates and t imes are local
Note 2: Inju ry class if icat io n abbrev iations
C = Crew
P = Passe ngers
0 = Othe rs
N = Ni l
F =Fatal
S = Se rious
M = Minor
e.g. C1S, P2M means 1 crew member recei ved serious injury and 2 passengers received minor
i nju ries.
W ater in an aircraft's fuel system will gravitate to the
lowest point o f the system . Fuel tank drain points are
provid ed at the low point of the t anks, thou gh in high win g a ircr aft in par ticula r , the low point of the system
is u sually in the p lumbing between tanks a nd en gines .
Frequently , a dd ition al drain p oints a re installed dur in g
manufactu re to cater for this problem. In some other
case s - for exam ple, certa in models of th e Cessna 182
- remedial action in th e form o f an Airwor th in ess
Directive has been taken , necessitating modification of
th e fuel system. S imila rly , C essn a Service L etter
S E 812-24 deta ils a r etrofi t kit to in stall fu el line drain
valves on Cessn a 150/ 152 m o dels.
I nvestigation of o ne accident revealed that the pilot of
a Cessn a 182P was unawar e o f the p rovision o f an
add itional fu el d rain poin t on the a ircraft. Using the
fuel tank drain poin ts indicated in the a ircraft
h andbook , the p ilot had d etected water con tamination
and had been careful to continue d r ain in g fuel until
clea r samples wer e obtained. H owever , the a ircraft had
been m odified in accordance with Cessn a Airworth iness
Directive 180/63 , which required th e installation of a n
additional drain valve a t the fu el selector , to e nsu re
p roper drainage in the event of water con tamination.
Becau se the pilot d id no t dra in that valve, water
r em a ined in the system an d eventu ally cau sed an
en gin e failure.
*
*
*
Apart from highligh ting the absolu te importance of
t horou ghly completing fuel wa ter drain checks, this
occu rrence ra ises two other importa nt po ints, on e
relating to keeping water out of fuel system s and the
. other to system s knowled ge .
12 I Aviation Safety Digest 120
Prevention
On the basis th at p revention is better than cure, all
step s sh ould b e taken to stop water entering the fuel
system . Water can en ter a fuel system in three ways:
• it m ay be pumped in from con taminated stock;
• it m ay condense from humid air; or
• it m ay leak in t hrou gh faulty fuel caps or im p roperly
fitted inspection pla tes.
The first two p ossibilities ca n be pr evented by careful
filterin g of suspect stock and by keep in g fuel tanks as
full as possible .
The main problem ar ises from faulty fu el cap s, which
not only allow water to en ter th e cells but also ca n
cause blad der -type cells to collapse and syphon fuel
overboard in flight . It is extremely imp or tant for fuel
cap s and adap ters to be regularly inspected for pr op er
sealing. Whenever leakage is su spected a leak test, in
accor d ance wit h the manufacturer 's instructions, should
be complet ed .
Systems knowledge
While this ar ticle h as dealt sp ecifically with aircr aft fu el
system s, the principle involved ex tend s beyond a
pa rticula r system or aircr aft type. I t is a req uirem en t
that a pilot wh ose licence includes a group endorsem en t
shall not act as pilot-in-co m mand u n less he is fam iliar
with his aircr aft's systems. The aircr aft owner is
respon sible to ensur e th at th e pilot com plies with this
requiremen t. W h en a system has been modified , the
own er must be p ar ticularly careful to d raw the p ilot's
atten tion to the m odification a nd its implications e
PRELIM INARY REPORTS (The fol low ing accidents are sti ll under in vestigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
02 Oct
Cess na 172 M VH-UG P
Non-commercial- pract ice
C1N , P1N
1630
Green Head, WA
Gree n Head, WA/Green Head, WA
8351024
Wh ile conduct ing a serie s of pract ice circ uits, the pilot noted that a crossw ind from the right was ev ident down to 50 ft on the
approach but the wind at gro und level was blowing down the s trip in use. On t he last c ircuit a normal approach was mad e,
howeve r, sh ortly a fter touchdown the a ircra ft began to d rift, des pite the applicat ion of corrective rudder. A go-around was made
but the drift to the rig ht cont inued. Flap was ra ised but contro l was then los t and the airc raft s truck trees .
04 Oct
Victa 115 VH-MUA
Ins tructiona l- solo-s uperv ised
C1M , P1 N
1500
Singleto n, NSW
Si ng leton, NSW/Sing leton, NSW
8321077
The st uden t pilot was briefed to conduct a period of s olo conso lidation train ing. After s everal circuits and land ings had been
comp leted the pilot flew the airc raft to a s trip at a nearby mil itary insta llat ion. A passenger boarded the aircraft an d the pi lot th en
conducted a takeoff , with the inten tion of making a local flight. A partia l loss of engine power occurred and the a ircraft
subsequen tl y s truck the gro und at a hi gh ra te of des cent and came to res t inverted.
08 Oct
De Hav 82 A VH- KLH
Non-commercial- pleas ure
C1 N, P1 N
1559
Ban ks town, NSW
Ba nkstown, NSW/Bankstown, NSW
8321079
Aft er a one -ho ur flight in the loca l traini ng area the pilo t entered th e c ircuit for a full-stop landing. The ATIS broadcast ind icated
t hat a 10 kt crossw ind could be expected. The initial to uchdown was heavy and the aircraft bounced. The pilot then attem pted to
la nd the ai rcraft in a 3-point atti tude, but the touchdown was aga in heavy and the main gea r part ia lly co llapsed.
08 Oct
Cess na 177 RG VH -IRO
Non-commercia l- pleas ure
C1N , P1N
0941
Kingston, SA 70NW
Paraf ie ld, SA/Robe , SA
8341031
During cru ise a t abou t 1000 ft agl the en g ine began to run ro ughly and the pilot obs e rved fa lling oil pressu re ind icat ions. A seve re
eng in e vib ra ti on then developed and the pilot, after s elect ing a s uitable fo rced land ing area, shut down the eng ine. He de layed
lowering the land ing gear unti l he was s atis fied that the selected area had a firm s urface. The gear was s elected down on very late
final, but on ly the nosegear had lime to become partially extended before to uc hdown.
09 Oc t
Pitts S1 VH-IWC
Non-commercial- pleasu re
C1S
1700
Stawe ll, Vi c 15NE
Stawell, Vic 15NE/Stawell, Vic 15NE
8331029
The aircraft was one of many wh ich had flow n into a barbec ue at a private a irfie ld. The pi lot was asked if he wou ld provide an
aerobatic display, and du ring the day carrie d o ut three. Aft er completing the third dis play, the aircraft flew past t he gathering , at
about 500 feet above the ground, pu lled up steeply and turned through 180 degrees to land stra ight ahead. It then descended
s teep ly at low forward speed and s t ruck the ground heavi ly in a nose-down attitude.
A viation Safety Digest 120 I i
�PRELIMINARY REPORTS (The fo llowing accidents are stil l under i nvestigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
PRELIMINARY REPORTS (The fo l lowing acc idents are still under investigation)
Injuries
Record number
Date
Time
Commercial-mapping/photo/survey
C1 F, P1 F
Hiller UH12-E VH-FFC
11 Oct
Longton Property, Qld/Longlon Properly, Qld 8311066
Longton Property, Qld
0630
The pilot, with his wife as passenger, was conducting a bore in specti on. A search was inst igated when the helicopter did not
return by nightfall. The wreckage was found the next morning. The helicopter had struck the ground i n an inverted att itude
amongst trees in a dry swamp.
03 Nov
1602
.,
Piper 25 235 VH-PPP
Tamworth , NSW
Commercial-aerial agriculture/bai ting
C1N
18 Oct
Piper 25 235/A1 VH·FAW
8331030
Drysdale, Vic 2SW
Drysdale, Vic 2SW/Drysdale, Vic 2SW
1330
On arrival at the agricultural strip, from wh ich he had operated many times before, the pilot observed that the grass on both sides
was thick and long. During the ensuing takeoff which was made in the opposite direction to the landing, th: left spray boom
entered the grass. The aircraft, which was j ust airborne, swung sharply to the left. The ri ght wing struck the ground and the
sideways movement brought the aircraft to a stop with the propeller still turn i ng.
06 Nov
1530
Piper 28 140
Bunyip, Vic
Commercial-aerial agriculture/baiting
C1N
23 Oct
Cessna A188 A1 VH·KVK
Oatleigh Station, NSW/Oatleigh Station, NSW 8321082
Canowi ndra, NSW 6E
1040
The ai rcraft completed a spraying run and landed on a strip located in an oatfield in which the surrou nding crop averaged one
metre in height. A section of this crop which was growing on a low earth mound was half a metre hi gher. After touchdown , the
right wingtip entered this section of oats, the aircraft sw ung rapidly to the right and the left wingtip and tailplane struck the
ground.
06 Nov
1730
Commercial - aerial ag riculture/bait i ng
C1 N
Piper 25 235 VH-FUM
26 Oct
Beaufort, Vic 16WSW/Beaufort, Vic 16WSW 8331031
Beaufort, Vic 13SW
1700
After the pilot had levelled the aircraft, loaded spray and carried o ut a fuel drain check, he commenced spraying a nearby wheat
crop . Part way through a procedure turn at the end of a spray run, the engine lost all power. The pi lot level led the wings and, after
avoiding a farmhouse ahead, dumped the spray load. The ai rcraft struck a power line, trees and the ground .and fire broke out
immediately. The pi lot escaped from the wreckage.
C1N , P1N
Commercial - mapping/photo/survey
Pi per 23 250 VH-WAB
27 Oct
8331032
Moorood uc, Vic
Moorooduc, Vic/Moorooduc, Vic
1055
The aircraft was being .used for scenes in a TV film production. For a particu lar sequence, the film crew positioned a remotely
control led camera about 400 metres along the runway from where the takeoff roll was to commence. The pi lot applied ful l power
before releasing the brakes, but as the airc raft became airborne the right wheel s truck the camera, breaking part of the landing
gear retraction mechanism. The aircraft was flown to Moorabbin and a wheels-up landing was made.
Non-commercial - business
C1F
01 Nov
Mooney M20 F VH·C IV
8311072
Bil oela, Qld 2.5N
Shauna Downs, Qld/Biloela, Qld 2.5N
1438
The pilot was making an approach to land at his private strip. The landing gear struck a fence at the end of the stri p and the
aircraft touched down on the 'nose wheel, right main wheel and the right wingtip after slewi ng about 45 deg rees to the i ntended
landing direction. Witnesses then heard the sound of a substantial power increase and the aircraft was seen to climb steeply to
about 100 ft before descending and striking the ground in an inverted attitude.
C1N
Piper 28 R180 VH-PFB
Non-com mercial - pleas ure
01 Nov
8321083
Cessnock, NSW/Warnervale, NSW
Warnerval e, NSW
1545
There was a low cloud base in the circuit area and the pilot concentrated on remaining clear of c loud. He stated that he flew a
tight circuit and carried out downwind checks but omitted to lower the gear. The gear override select or was in the inoperative
position and the aircraft was landed with the gear retracted .
ii I Aviation Safety Digest 120
Commercial-assoc . agricu ltu re/bai t ing
Tamworth, NSW/Gunnedah, NSW
C1N
8321085
Shortly after becom ing airb orne, the pilot observed that t he temporary fabric covering on the left wing was bal looni ng, and
adv ised the Tower that he was returning. The ai rcraft turned left until lined up wi t h strip 18 and the pilot advised that he would
recheck the condit ion of the left w ing and might land downwind . He stated that the nose and left wing dropped sudden ly and that
despite corrective flight contro l action, he was unable to prevent the aircraft striking the ground.
Piper 28 R201 VH·PRF
Bankstown , NSW
Commercial - aerial mustering
C1N, P1N
Bell 47 G5A VH·B H R
24 Oct
Wando Vale, Qld/Wando Vale, Qld
8311070
Wando Vale 29NNE
0945
The pilot elected to conduct a practice autorotation. His initial intention was to reapply power and discontinue the exercise
before reaching the ground, but during the descent he chan ged his mind and decided to continue to the ground. As the pi lot
flared the helicopter the tail skid contacted the ground and the main rotors struck the tai l boom and tail rotor shaft.
Injuries
Record number
Amer Air 5 A VH-IFY
Non-commercial - pleasu re
C1N , P2N
8321084
Koorawatha, NSW 2E
Bankstown, NSW/Cowra, NSW
On completion of several orbit s at abou t 600 ft ag l, t he pilot applied f ul l powe r to climb to his in tended cruising alt itu de. A rap id
knocking noise was heard from the engine and the pilot discovered that the frequency of t he noise was related to the throttl e
setting. He elected to conduct a precau t ionary landing on a nearby agricu ltural st rip. The aircraft touched down normall y, but
during the land ing roll it collided wit h a temporary fence erected across the s t rip.
04 Nov
1807
C1F, P3F
Non-commercial - business
24 Oct
Cessna 310 L VH·DT J
Clermont, Qld 27N E
Rockhampton, Qld/Kenlogan, Qld
831 1069
1108
The aircraft was flown to the airstrip after the pilot had been unable to locate hi s destination. Witnesses saw the aircraft make
three ci rcuits of the strip and reported that the landing gear was extended for the third circuit. T he aircraft was lost to sight
behind a hill on part of the final downwind leg. Witnesses then sighted a c loud of black smoke and found the wreckage 800 m
short of the strip threshold. In tense fire prevented rescue attempts.
Kind of flying
Departure point/Destination
02 Nov
1500
C1M
Commercial-aerial agriculture/bai l ing
Piper 25 235/A 1 VH-FOO
13 Oct
8321080
Cowra, NSW/Cowra, NSW
Cowra, NSW 8W
0730
The pilot carried out an aerial survey of the area to be treated and commenced sprayi ng. The initial run was made below power
lines crossing the centre of the crop , and the third run was in the same direction. As the aircraft approac hed the power lines the
pilot's at lent ion was distracted and the windscreen and canopy struck the lower two cables. The aircraft turned to the right and
crashed into an adjoining field.
C1F
Commercial-aerial agriculture/baiting
Piper 25 235 VH ·CDU
16 Oct
Tin ti nara, SA 25SW/Tintinara, SA 25SW
8341029
Tintinara, SA 25SW
1030
The pilot was engaged in spraying a crop of lupins. The ai rcraft was observed to fly from one paddock to another on the property .
A short time later a tree in that paddock was observed to be on fire. The wreckage of the aircraft was later found in the paddock.
The ai rcraft had struck the ground in an inverted attitude and was completely burnt out by the ensuing fire.
Aircraft type & registration
Location
Non-commercial -pleasure
C1N, P2N
Dubbo, NSW/ Ban kstown , NSW
8321086
The pilot believed that he had selected gear down as the aircraft turned on to the base leg, bu t it touched down with t he gear
retracted .
VH·CTF
Non-commerc ial-pleasure
Bunyip, Vic/Tooradin , Vic
C1N, P2N
8331033
The aircraft had landed in a paddock with 10 cm long grass. Wh i le taxiing for the subsequent takeoff the pilot conducted a
satisfactory acceleration check. On t akeoff the aircraft lifted off at 60 kt, cleared t he boundary fence but then sank and s t ruck
another fence. The impact tore out th e right gear leg. The pilot was not aware of the ful l extent of the damage but elected to d ivert
to Moorabbin and made a successfu l emergency landing.
Piper 25 235 VH-WNY
Derrinal lum, Vic
Commercial-aerial agricu ltu re/bai ti ng
Derrinal lum, Vic/Derrinallum, Vic
C1N
8331034
The pi lot made one takeoff under a power line wh ich crossed the st rip 150 metres from the northern boundary. He then completed
a number of sprayin g runs before land ing . He uplifted the same quan t ity of spray and commenced the second takeoff in t he same
direction. The aircraft passed under t he power line, bu t the undercarriage and left wing struck the boundary fence. The pi lot
dumped the load and returned to land.
06 Nov
1200
Piper 25 235/A1 VH-FAL
Narromine, NSW
Tow ing gliders
Narromine, NSW/ Narrom ine, NSW
C1N
8321088
Because the run way was occupied by a glider, t he pi lot of the tug aircraft elected to land on t he f ligh t s t rip. On late final app roac h
another glider was pushed onto the flight strip, obst ructing the intended land ing path. The pilot elected to continue the approach
and aimed to touch down just out side the confines of the strip. Shortly after touchdown the land ing gear became entang led in
long weeds and the aircraft overturned.
06 Nov
1000
Piper 28 161 VH-MHR
We llington, NSW
Noncommercial -pleasure
Wellington, NSW/ Bankstown, NSW
C1N, P3N
8321087
The pi lot was conduct ing a takeoff from a s t rip with a 2 per cent up-slope. He reported that the takeoff was normal unti l the
aircraft had reached a heigh t of about 20 ft , at which point t he rate of cl imb decreased to zero. The stal l warn ing sounded and the
pi lot lowered t he nose and flew the aircraft back onto the ground. It col lided with the boundary fence and the pilot then
abandoned the takeoff. The aircraft came to rest about 300 m beyond t he end of t he st rip.
07 Nov
1510
Cessna 172 N VH ·CSG
Crookwell, NSW 6N
Non-commercial - pleasure
Crookwe ll, NSW 6N/Canberra, ACT
C1N
8321089
The pilot conducted an examinat ion of the strip and estimated the length as 400 m. He subsequent ly stated that the ai rcraft
appeared to accelerate normally during the ini tial takeoff rol l, but the rate of accelerat ion then slowed. The aircraft was rotated
prematu rely i n an effort to clear the boundary fence, but the landing gear struck the top of the fence and the ai rcraft landed in an
adjoinin g paddock.
08 Nov
1230
Transavia PL12
Caldwell, NSW
VH -EVH
08 Nov
1130
Auster 3 F VH-MBA
Cootamund ra, NSW
Commercial -assoc . ag ricult ure/bait ing
C1N, P1N
Caldwell, NSW/ Barham Base Camp
8321091
At about 300 feet agl on c limb out, the pi lot heard a loud bang and saw that the propeller had separated from the ai rcraft . He
lowered the nose to regain airspeed but the ai rcraft descended steeply and landed heavily in a rice paddy.
Non-commercial -pleasu re
Cootamundra, NSW/Cootamundra, NSW
C1N, P1N
8321090
During the course of a local flight, strong gust ing winds were encountered and the pilot decided to return for a landing. He stated
that as the ai rcraft was about to touch down , it was affected by a sudden strong tai lw ind, and the nose struck the runway. The
wooden propel ler was shattered, both wingtips came into contact with the runway and the tailwheel was torn off befo re t he
aircraft came to rest.
09 Nov
1605
Cessna 152 VH-MRP
Pennant Hi lls, NSW
Instructional - dual
Bankstown, NSW/Bankstown, NSW
C1M , P1N
8321092
The pilot reported that after the aircraft struck a bi rd t he engine began to overheat. It then started to run roughly and the pilot
decid ed to land the aircraft on a golf cou rse. After touching down on a fairway heavy braking was applied and the nose wheel and
propeller dug into the soft ground.
Aviation Safety Digest 120 I iii
�PRELIMINARY REPORTS (The following accidents are st ill unde r investigation)
Injuries
Record number
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
11 Nov
1400
Bell 47-G5 VH-JGF
Darwin, NT 93SE
Commercial-aerial mustering
C1N
Mt Bundey Homestead/Mt Bundey Homestead 8341032
The pilot was engaged in mustering a group of buffaloes t owards a gate between two paddocks. As he began to transit ion from
the hover to forward flight, the pilot reported that the aircraft shook violently and the engine then lost all power. The aircraft
yawed to the right, descended steeply and struck the ground.
13 Nov
1355
Schneider ES-49 VH-GFO
Blanchetown, SA
Instruct iona l-dual
Blanchetown, SA/Blanchetown, SA
C2N
8341033
The glider was aligned on final approach above the desired glide path. The instructor decided to demonstrate sidesl ipping as a
method of losing excess height. At about 200 ft agl the demonstration was discontinued but a high rate of sink pers isted. The
glider landed 70 m short of the threshold and the pilot was unable to avoid obstacles during the ground run.
15 Nov
0712
Mitsubishi MU2B 30
Cairns, Old
VH-CJP Charter-cargo
Town sville, Old/Cairns, Old
C1N, P1N
8311073
The aircraft was established on final by the pilot under check. A 5 kl downwind com ponent prevailed. The flare was commenced
higher than normal and the airspeed decreased below the optimum. The pilot did not react to prompting by the check pilot and
retarded the throttles. The aircraft struck the runway heavily in a left wi ng low attitude and the left main and nose gears were torn
off.
18 Nov
0130
Piper 24 400 VH-FOE
Hamilton, Vic
Non-commercial-pleasure
Hamil ton, Vic/Unknown
C1F, P1F
8331035
At about 0200 hours, the pilot and passenger boarded the aircraft for a local fli ght. A resident heard it take off and saw the aircraft
lights in the circuit area. He also noted that the runway lights were illuminated. A go-around was made on the first ap proac h and
the aircraft was landed after another circuit. A takeoff was carried out in t he opposite direction and shortly after becom ing
airborne the aircraft struck t he ground. Fire broke out and engulfed the wreckage.
19 Nov
1815
Cessna 210 L VH-PZO
Swifts Creek 10SW
Non-commercial-pleasure
Swifts Creek 10SW/Lilydale, Vic
C1N, P5N
8331036
As the strip at the planned destination was unsuitable the pi lot elected to use a nearby agric ultural strip. After landing, he found
that the grass was longer than he had anticipated and he arranged to drive a vehic le over the strip several times to flatten the
grass. On the subseq uent takeoff roll the aircraft ran off the side of the flattened area and the rate of accelerat ion slowed. The
aircraft became airborne but struck a fence and came to rest in an adjoining paddock.
20 Nov
1235
Piper 28 140 VH-SVG
Moorabbin, Vic
Instruct ional-solo-supervi sed
Moorabbin, Vic/Moorabbin , Vic
C1 N
8331037
On the landing roll during a solo training exercise, the aircraft drifted to the left side of the runway. The stude nt pilot overcorrected and the aircraft ran off the runway. The nose gear folded back and the propeller struck the ground.
22 Nov
1800
Cessna 172 M
Echuca, Vic
VH-IMY
Instructional - solo-supervised
Echuca, Vic/Echuca, Vic
C1 N
8331038
After a period of dual training, the pilot was sent on his first solo flight. The landing approach was made at 75 knots to the flare
point, and the touchdown was in 3-point attitude. The aircraft bounced, the nose dropped and the second touchdown collapsed
the nose gear. The aircraft skidded off the runway and overturned .
24 Nov
2215
Cessna 210 L
Mildura, Vic
VH-FOC
Non-commercial-pleasure
Orange, NSW/Mildura, Vic
C1 N, P1N
8331039
On final approach the pil ot opened the throttle to adjust the glide path but the engine failed to respond. The aircraft landed in a
paddock, about 150 m short of th e aerodrome boundary and ran through a fence and a ditch before coming t o rest with the nose
gear assembly dislodged.
27 Nov
1415
Piper 28 140
Zeehan, Tas
VH-CHR
Non-commercial-pl easure
Devonport, Tas/Zeehan, Tas
C1N, P1 M
8331040
The pilot had previously checked the st rip dimensions, and on arrival over the top , made a thorough appraisal of t he area. He
noted that there 111as a crosswind from the right gusting to 15 knots. He stated that on short final approach at a low height, the
aircraft dropped s uddenly, and despi te the appl ication of power, struck the lip of a ditch. The gear legs were detached, and the
aircraft slid to a stop 13 metres s hort of the threshold.
30 Nov
1605
Beech 200 VH-AAZ
Lord Howe Is land
Scheduled passenger service - comm uter
Sydney, NSW/Lord Howe Island
C2N, P5N
8321093
The aircraft floated for some distanc e after the landing flare, and touched dow n f irmly, right wheel first: As the pi lot selected
reverse thrust, the aircraft sett led slowly to the right. The check pilot observed an unsafe gear indicat ion for the right main gear,
and shut down the engines. The airc raft stopped o n the runway after sl iding for ap proximately 400 metres.
02 Dec
Piper 28 140 VH·RUA
Non-commercial-pleasure
C1N , P1N
O'Connell, NSW 3SE
Gunning, NSW/O'Connell, NSW 3SE
8321094
1120
The pilot had not landed at the strip before, and made four inspect ion runs prior to approaching to land uphill. There was a
gusting crosswind from the left. He stated that as he flared to land, the aircraft suddenly veered to the right, and he applied full
power to go around. The aircraft could not o utclimb the rising terrain, and to uched down in an adjacen t f ield. It ran through a
fence and struck an earth bank. The nosegear was torn off and the aircraft overturned.
iv I Aviation Safety Digest 120
PRELIMINARY REPORTS (The follow in g accidents are stil l under invest igation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
C2N
Czech Blanik L13 VH-GAP
Inst ructional- dual
03 Dec
Cranbrook, WA/Cranbrook, WA
8351028
1900
Cranbrook, WA
At about 50 feet after liftoff on a winch launch, a winch power fai lure occurred. The instructor disconnected t he tow cable and
landed straight ahead. In the resu lting heavy land ing t he main wheel was pushed upwards through t he cockpit floor.
C2N
Instruct ional-dual
04 Dec
Piper 30 VH-DIC
Bankstown, NSW/Bankstown , NSW
8321095
1037
Bankstown, NSW
The pilot was undergoing in itial twin-eng ine endorsemen t training . On the third touch-and-go landing, the instructor ret rac ted the
f laps, adv ised the pi lot that he had done so and instructed him to proceed w i th t he takeoff. The pilot inadvertent ly retracted t he
gear and the aircraft sett led to the runway.
C1 N, P2M, P1 N
04 Dec
Cessna 210 VH-AEC
Non-commerc ial - pleasure
8311076
Glenden, Old/Midge Point, Old
1125
Midge Point, Old
After a normal approach in gusty crosswind cond it ions t he aircraft touched down near t he threshold of the st rip. It bounced
sl ight ly before settli ng onto the groun d with about 650 m of strip remaining. The pilot su bsequent ly reported t hat t he brakes
failed to have any retarding effect and he was un.ab le to prevent the ai rcraft from over-running the strip. After crossing a road the
ai rcraft entered a gully and overturned.
05 Dec
1016
Cessna 501 VH-B NK
Kalgoorlie, WA 11 E
Non -commercial - corporate/executive
Adelaide, SA/Kalgoorlie, WA
C1N , P5N
8351029
The f li ght was planned to cruise at F L 370 w ith a 50 kl headwind component. At an intermediate s topover the pilot checked the
forecast win d and amend ed t he cruis ing level to FL 290. Whi le on descent in cloud , t he low fuel warnin g ligh t illuminated and
shortly after the rig ht engine f lamed ou t. Relight attempts were unsuccessful. Descent was continued unti l c lear of c loud at 1000
ft agl, when the left engine f lamed ou t. A gear-up landing was made on a firebreak.
C1N
Non-commercial - pleasu re
07 Dec
Pi tts S1-S VH-KKT
Roma, Old/Toowoomba, Old
8311080
1100
Dalby, Old
At the end of t he landing ro ll, the pilot unlocked the tai lwheel and commenced to tax i back along t he landing path. Wh ile
travelling at about 20 kts with the win d from t he ri ght rear quarter t he ai rcraft began to veer to the right. The pilot attempted to
correct the situation but the aircraft groundlooped to t he righ t and t he lower left wing struck the runway .
Commercial - aerial mustering
C1N
07 Dec
H iller UH1 2 E VH-FBF
8311077
Mackay, Old 148S
Mackay, Qld 148S/ Mackay, Old 148S
1130
Wh il e cru ising at 150 ft ag l and 40 kts t he eng ine failed. During the subsequent attempted autorotational landing t he pi lo t t ried to
turn the helicopter into wind but a heavy lan ding resulted while t he helicopter was still d rift ing to the r ight. The land ing skid
attachments collapsed and the main rotor and tail rotor st ruck the ground as the hel icopter bounced and tilted to the right.
08 Dec
1045
Hiller UH12-E VH-PYH
Commerc ial-aerial agr icu lture/ba it ing
C1N
Kil larney, Old 6S/Killarney, Old 6S
Killarney, Old 6S
8311078
On the ini t ial spray run the helicopter struck a low-slung power line. After the w ire strike the helicopter began to vibrate. The pil ot
carried out an immediate land ing withou t further damage bein g incurred.
08 Dec
1030
Cessna A188B A1 VH-IBO
Leeton, NSW 9SW
Commercial - aerial agricu lture/baiti ng
Brobenah Strip, NSW/Brobenah St rip, NSW
C1N
8321096
During rice-s pray ing operations the ai rcraft was flown under a power line. On one swathe run t he top of the fin and rudder st ruck
the line. The pilot was abl e to retain control of the aircraft wh ich was subsequen tl y landed w it hout further damage.
Cessna 210 N VH -B KD
Non -commerc ial - pleasure
C1 N, P4N
08 Dec
831 1079
Longreach, Old/Broken Hi ll, NSW
1515
Longreach 148S
Du ring cruise the pilot noticed an indication of a high battery discharge rate and that the alternator and gear pu mp circuit·
breakers had tripped. Attempts to reset the circuit-breakers were unsuccessful. Smoke was then observed in the cen tre console
area and t he pi lot decided to land on a short disused st rip. During the landi ng rol l the ai rcraft overran the st rip and to avo id
ru nning through a gully the pilot stopped the aircraft by steering into a tree.
C1M, P2N
10 Dec
Cessna 182 0 VH-TLD
Test
Coo langatta, Old/Coolangatta, Qld
831 1081
Coolangatta, Old
1423
The ai rcraft had not been f lown for about two months. During that t ime it had been washed regu larly and had been parked in t he
open. The pi lot conducted a water check before ground runn ing t he engine and he then elected to fly the aircraft. Further water
checks were conducted before the aircraft was positioned for takeoff. At about 200 ft ag l t he engine failed comp letely and t he
aircraft overt urned during the subsequent forced landing .
Cessna P2 10 N VH-SWM
Non -commercial - pleasu re
C1 N
14 Dec
Launceston, Tas 23S/Launces ton 23S
8331042
1530
Laun ceston, Tas 23S
After touching down on a mown area o f a paddock, the aircraf t became airborne over a slight hump. Fol lowing t he second
touchdown, the pilot ap plied the brakes but was unable to prevent the ai rc raft hitti ng a gate. It then ran across a road and struck
an eart h ban k, collaps ing the gear.
Commercial - aerial ag riculture/bai t ing
C1N
H iller UH 12-E VH-FFV
17 Dec
Gympie, Old 15SE/Gympie, Qld 15SE
831 1082
11 50
Gympie, Old 15SE
As the pilot was posit ioning t he helicopter t o commence a spray run, t he engine lost powe r. An autorotatio nal descent was
carried out but the aircraft landed heavily on slop ing terrain.
Aviation Safety Digest 120 I v
�FINAL REPORTS (The investigation of the following accidents has been completed)
PRELIMINARY REPORTS (The fol low ing accidents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Date
Time
Pilot licence
Injuries
Record number
17 Dec
Burkhart Astir CS VH-WV I
Non-commercial-pleasure
C1S
Richmond, NSW
Richmond, NSW/Richmond, NSW
1310
8321097
The pilot stated that the glider became high on final approach after enco untering lift. He extended the air brakes and side-slipped
steeply, then levelled the wings. The glider continued to descend and struck the ground 150 metres short of the normal
touchdown area.
18 Dec
1203
Volmer VJ21 VH-TUB
Latrobe Valley, Vic
05 Oct
1800
Private
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Inj uries
Record
number
C1,N
8351025
50
Non-commercial-pleasure
Gnowangerup, WA/Wellstead, WA
1477
1400
None
Cessna 150 B VH-RWM
Wellstead, WA
At the conclusion of an approach to a private strip the pilot held the aircraft off the ground for longer than normal. The resulting
nose high attitude caused him to lose sight of the strip. The aircraft drifted under the influence of a crosswind and shortly after
touchdown the left wing struck two trees at the side of the strip. The nosewheel was detached after striking a mound of earth and
the aircraft came to rest inverted.
The trees on the side of the strip reduced the effective width to below the minimum standard for ALA operations. During the
extended hold-off prior to touchdown the pilot had not made adequate compensation for the wind conditions existing at the time.
C1M
8331043
At about 400 ft agl on climb after takeoff, the pilot reported hearing a loud bang. Engine power was reduced but the source of the
noise could not be located. As power was reapplied the engine ran roughly and the pilot decided to land the aircraft in a paddock.
During the approach, the pilot realised the aircraft was overshooting and forced it onto the ground to avoid a fence. The left wing
struck the ground and the aircraft turned through 180 degrees before coming to rest.
Non-commercial- pleasure
Latrobe Valley, Vic/Yarra Glen, Vic
06 Oct
1220
Commercial
Commercial-aerial agriculture/baiting
C1 N
Agstrip on property/Agstrip on property
8321078
6800
4000
Agricultural Class 1
35
The pilot had completed three hours of crop spraying, and clean-up runs were required to finish the operation. Towards the end of
the first of these runs, the pilot altered heading to fly below power lines traversing the crop. During the turn, the right wingtip
entered the wet wheat and the aircraft was dragged into it. The right wing struck the ground, the aircraft cartwheeled horizontally
through the wheat and hit the boundary fence.
21 Dec
Cessna T188C VH -KZI
Commercial-aerial agriculture/baiting
C1 M
0450
Wee Waa, NSW 28W
Redlands CNee Waa 5E)/Redlands CV'Jee Waa 5E)8321098
As the aircraft was climbing away at the completion of the first run of a night spraying operation, the main gear legs struck a
power cable. The cable broke away from the power pole insulators and remained attached to the aircraft, which struck the ground
200 metres beyond the line of the poles.
24 Dec
1627
Aircraft type & registration
Location
Czech L40 VH-DUE
Geelong, Vic 25W
Piper 25 235/A1 VH-FAU
Tocumwal, NSW 16NE
Non-commercial - pleasure
C1N
Skipton, Vic/Tyabb, Vic
8331044
During the cruise the engine began to misfire and lose power. The pilot carried out a precautionary landing on a road , but during
the landing roll the left wing struck a road signpost. The force of this collision caused the aircraft to swing to the left and it ran
through a fence before coming to rest in an adjacent paddock.
The pi lot experienced difficulty in judging his height above the crop because the light wind conditions did not produce any
significant swaying of the crop. The turn to the right was initiated while the spray run was in progress and the pilot began
concentrating on the manoeuvre required at the end of the run in order to position for the following run. The crop was wet and
dense and control of the aircraft could not be maintained after the wingtip had entered the crop.
25 Dec
Piper 32 R300 VH-UAM
Non-commercial-pleasure
C1 N, P5N
Brampton Island
Charters Towers, Old/Brampton Island, Old
8311083
1744
The pilot misjudged the height of the aircraft above the ground when he initiated the landing flare. Touchdown occurred at a high
rate of descent and the left gear collapsed.
13 Oct
Cessna 182 E VH-AKM
Non-commercial-pleasure
C1 N
1130
Woodstock STN20SW
Esmeralda Stn, Old/Gladevale Sin, Old
8311067
Private
53
4600
4550
None
At the start of operations for the day the aircraft carried about 225 litres of fuel. After approximately four hours cattle mustering in
the aircraft the pilot commenced a flight to his home property. Twenty minutes later the engine fai led and during the subsequent
landing on unsuitable terrain the aircraft collided with trees.
Fuel had been lost through venting because the right tank fillercap had not been properly secured after the last refuelling. The
bag-type fuel tank had collapsed and caused a false fuel contents indication. The engine failed due to fuel exhaustion.
30 Dec
1645
Cessna 172 N VH-UNR
Streaky Bay, SA 2N
Non-commercial-business
C1N, P3N
Streaky Bay, SA 2N/Streaky Bay, SA 2N
8341034
The pilot reported that, as the aircraft was being manoeuvred for landing with a right crosswind , a gust from the left lifted the left
wing and caused the aircraft to touch down to the right of the strip on a heading about 30 degrees from the runway direction.
During the landing roll the aircraft was turned towards the runway but the right wing and landing gear collided with a parked car.
17 Oct
1333
Commercial
Cessna 310 K
Parafield, SA
VH-PSB
39
Test
Parafield, SA/Parafield, SA
1214
150
C1N
8341030
None
During takeoff on a check flight a loud bang was heard from the area of the nose gear after the gear was selected up. The nose
gear did not retract fully, nor cou ld it be extended. On landing the nose gear retracted and the aircraft slid to a halt on its main
wheels and nose.
The nose oleo had deflated during taxi and takeoff. When the gear was selected up, the nose wheel mudguard came in contact
with a door bracket and the operating linkage failed, permitting the nose strut to swing free. The oleo had deflated because a seal
in the strut had hardened, due to age, and allowed the air pressure to bleed off.
l
Commercial-aerial mustering
C1 N, P1 N
19 Oct
Hughes 269 C VH-THN
Kondoparinga Stn, Old/Kondoparinga Stn, Old 8311068
0745
Kondoparinga Stn, Old
Commercial
30
2400
2150
None
Helicopter
After positioning for a mustering task the pi lot shut down the aircraft for about an hour. The pilot then took off for his task and
landed at a cattle yard enroute without shutting down. During the subsequent takeoff when at a height of about 40 ft agl and an
airspeed of 20 kt, the engine backfired and lost power. While attempting to land the helicopter in a small clearing both main rotor
blades struck a dead tree.
The cause of the engine malfunction was not determined.
28 Oct
Cessna 182 A VH-PUH
Non-commercial-business
C1N, P1N
0700
Dingo, Old 28NE
Woongarra, Old/Mourindilla, Old
8311071
Private
25
162
17
Instrument Rating Class 4
The strip being used was of adequate length and 90 m wide. The threshold of the north-west strip was marked by two posts 90 m
apart and two drums between these posts. The drums were hidden in long grass and the pilot was unaware that the posts defined
the threshold. On landing, the pilot touched down 19 m short of the threshold and the nosewheel struck a drum. The nose leg oleo
collapsed and after a short ground run the left wingtip struck the ground.
29 oct
Cessna 172N VH-BXG
Non-commercial-pleasure
C1M, P2M,
1000
Perth, WA 78S
Beacham, WA/Beacham , WA
P2N
Commercial
38
622
59
None
8351027
The pilot intended taking some friends for a local fl ight. The takeoff was commenced from the threshold of the 750 m gravel strip,
with 30 degrees of flap set. The pilot reported that the aircraft was not performing normally and when the stall warning sounded
he elected to land in a paddock. During the landing attempt the left wing struck the ground.
The pilot had only limited recen t flying experience. He was concerned about the position of obstacles at the end of the strip and
used a non-standard takeoff technique, which degraded aircraft performance. No contributing fault was found with the engine or
other aircraft systems.
vi I Aviation Safety Digest 120
Aviation Safety Digest 120 I vii
�FINAL REPORTS (The investigation of the following accidents has been completed)
Date
Time
Pilot licence
30 Nov
1530
Commercial
Helicopter
Aircraft type & registration
Location
Age
Hiller UH12-E VH-FFT
Gatton, Old 3W
32
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
Injuries
Record
number
Instructional-Check
C2N
Backmann Property/Backmann Property
8311075
6850
3500
Agricultural Class 1 and
Flight Inst ruc tor and
Inst rument Rat ings
During a check flight the pilot was executing an autorotational landing. A run-on land ing was made but the skids dug into the
ground and the helicopter nosed over. The main rotor blades severed the tail boom as the helicopter came to rest inverted.
Although high and low-level aerial inspections of the proposed area were carried o ut, neither pilot was aware ~ f the s ur f ~ce
condition before commencing the practice autorotational landings. The selected area proved to be soft and skid penetrat ion
caused the helicopter to nose over.
Non-commercial - pleasure
C1 N
Pilatus B-4 VH-GJQ
17 Dec
Bunyan, NSW/Bunyan, NSW
8321099
Bunyan, NSW
1230
80
Glider Rating
35
Glider
The pilot was making his first flight in this type of glider. There was a 5 to 10 kt wind f rom t he left and during the takeoff run the
aircraft began to veer to the left. The pilot attempted to correct the yaw with right rudder and raised the tail. The aircraft cont inued
to veer left, the pilot released the tow rope but the nose and left wingtip struck the grou nd.
FINAL UPDATES (The investigat ion of t he fo llowing acc idents has been completed. The information is
additional to that previous ly print ed in the prel iminary report)
Date
Pilot licence
Record number
Age
Hours total
Hours on type
Rating
22 Feb
Commercial
8321023
24
481
400
Flight Instructor Grade 3 and
Instrument Rating
Investigation revealed Iha\ due to excessive wear, the carburettor heat control cable had fai led at the attach po int wit h the
actuating bel lcrank. The air hose between the muffler and the carbu rettor hot air box had col lapsed internally. The combination of
the carburettor heat control fai lure in the "hot" pos ition and the obstruct ion at the alternate air source led to the loss of engine
power during takeoff. Shortly afterwards the aircraft stal led over flat open country.
06 Mar
Commerc ial
8311 016
22
850
50
Ag ricu ltural Class 2
The land ing distance avai lable was 120 m. The landing d istance required was 247 m. Although the pilot had previous ly made an
uneven tful landing on t he same area, he touched down with on ly 60 m remaining. No engine faults were detected wh ich could
explain a lack of engine response. The gear collapsed due to overload fai lure durin g the attempted ground loop. The brakes were
found to be defect ive due to excessive wear and leaks caused by using incorrect brake flu id .
10 Mar
Commercial
8351009
29
2300
350
Agricu ltural Class 1
The engine lost power aft er the fuel was exhausted from the selected fue l tank. There was sufficient fuel in the other main tank to
complete the flight.
12 Mar
Glider
8311 01 9
40
08 Apr
Private
831 1021
45
77
29
Glider Rat ing
Although t here was su ffici ent land ing d istance avai lab le to permit a straight landing roll , the pilot selected an area which requ ired
a cu rved path to be followed. Dur ing the approach and subseq uent landing roll the pi lot was unable to maintain adequate
directional control.
700
150
Instrument Rating Class 4
Invest igation revealed an accumulat ion of dirt on the nosegear assembly which prevented its geometry from ach ieving an overcentre lock. In additi on it was found that the nose wheei'microswi tch had been adj usted to show a down and locked indication in
this posit ion. Vi bration on the land ing roll unlocked the nose gear leg and initiated the retract ion.
11 Apr
Commercial
8321037
36
1561
687
Instrument Rating 1st or Class 1
No reason for the reported loss of performance during t he takeoff could be found. After the takeoff was abandoned the ai rcraft
hydrop laned on t he wet runway.
10 May
Pr ivate
8391001
39
05 Jun
Commercial
Helicopter
8311 032
47
500
Unknown
Instrument Rating 1st or Class 1
The invest igati on did not reveal any evidence of pre-accident mechanical or struct ural failure. The pi lot had had no previous flying
experience in PNG. At the time of the accident there was extensive cloud developing over the Owen Stanley Range which
inc ludes t errain over 14 OOO ft high .
3534
2650
None
The source of the screeching noise reported by the pilot was not determin ed. The pi lot had made an approach to land downwind
into the se lected area and had overshot . The tail rotor had struck a t ree on the edge of the clearing, wh ich was the most su itable
area available for an attempted forced land ing.
09 Jun
Commerc ial
8351018
27
250
5
Agricu ltu ral Class 1
No fault could be fou nd in t he airspeed-indicating system. The pilot's decision to attempt fault f inding was unnecessary and any
actions shou ld have been attem pted at a safe height. Du ring the descent the pilot failed to maintain an adequate lookout. T he
right-hand tai l plane was bent during the first co ll is ion , thus locking the elevators and causing the aircraft to pitch up.
11 Jun
Private
9311 035
54
413
350
None
The pilot did not comply with the pre-flight briefing to return to the last turn ing po int in the event of becom ing unsure of pos ition.
Prior to landing the pilot d id not carry out an adequate inspection of the intended landing area.
18 Jun
Senior Commercial
8321049
22
2950
300
29 June
Commerc ial
8341022
Unknown
Unknown
Unknown
Instrument Rat ing 1st or Class 1
and Fli ght Instructor Rating
The st udent pilot's previous experience had been confined to airc raft types in which the f lap selector was positioned at
approx imately the same location as t he gear selector lever on the Bonanza.
viii I Aviation Safety Digest 120
Instrument Rating 1st or Class 1
Aviation Safety Digest 120 I ix
I
~
�FINAL UPDATES (The investigation of the following accidents has been completed. The information is
additional to that previously printed in the preliminary report)
FINAL UPDATES (Th e invest igat io n of t he fo l lowing acc ide nts has been comp leted. The informat ion is
add it ional to that previously p rinted in the prelim i nary report)
Date
Pilot licence
Record number
Age
Hours total
Hours on type
Rating
Date
Pilot l icence
Record number
Age
Hours total
Hours on type
Rating
02Jul
Private
8311041
36
497
175
None
28 Aug
Private
8331 022
19
140
132
None
The loss of control occurred during a turn at low level. II is probable that the aircraft stalled as a resul t of poor airspeed con trol
and/or turbulence. Recovery was not effected before the aircraft had landed heavily on the mai nwhee ls. Loss of directional
control occurred in a crosswind on t he soil surface. No reason could be f ound for the reported lack of engine response but ii is
considered that the pilot may have used the pitch lever by mistake.
03 Jui
Private
8321054
55
1646
408
None
The hard landing occurred because the pilot stretched the glide approach in an attempt to achieve a landing on the aiming point.
04 Jui
Private
8311042
51
06Jul
Commercial
8311043
27
2315
1800
150
75
Instrument Rating Class 4
Instrument Rating 1st or Class 1
!h~ aircraft was loaded beyond the aft C of G limit and the elevator trim was set with excessive nose-up trim due to a faulty trim
1nd1cator. The a~rcraft was rotated prematurely and flying speed was not maintained. The ensuing loss of co ntro l led the pilot to
suspect an engine malfunction. Inappropriate emergency drills by the pilot delayed the takeoff abort. No fault was found wi th
either of the engines.
20 Jui
Private
8331019
73
500
200
None
The rough running of the _engine proba_bly occurred because of the fouling of several spark plugs by o il. The oi l contamination
resulted from the newly fitted piston rings not being "bedded-in " before the flight. The pilot misjudged t he approach and the
touchdown was made 600 m beyond the threshold.
20 Jui
Private
8351020
48
24 Jui
Private
8321056
37
3415
1100
3368
520
None
Instrument Rating 1st or Class 1
The area from which the aircr~ft was departing was relatively dark, with illumination provided by flood li ghts. As the person who
was struck approached the aircraft he was looking towards the f loodlights and would have had difficulty seeing the rotat ing
propeller disc.
27 Jui
Commercial
8311045
23
251
30
In strument Rating 1st or Class 1
The pilo! contin_ued. with the ci rcuit in unsuitable weather condition s. Insufficient atten tion was given to the maintenance of
altitude in the c1rc u1t and the missed approach was commenced at an altitude that was below the elevati on of the airf ield.
05 Aug
Commercial
8331021
25
731
91
Agri cul tural Class 1
The pilot had _minimal experience in spreading operations over hilly terrain . The positioning turn had been made towards rising
ground. A weight and performance penalty was incurred because sprayi ng eq uipment had not been removed from the airc raft
prior to the spreading operations. Thi s equipment also inhibited the rate at which a load cou ld be dum ped in an emergency
s ituation.
08 Aug
Private
8341025
42
5021
4708
None
Sufficient airspeed had not been maintained while manoeuvring at low level , and a stall had developed which the pilot had been
unable to correct in the limited height avai lable.
10 Aug
8311050
Senior Com mercial 27
2500
Instrument Rating 1s t or Class 1
The pilot had not flown a tailwheel aircraft for three years. The flight was initiated in wi nd c ondit ions which at times exceeded t he
crosswind limitations Ofl both runways available. At the time of the accident a crosswind gust of 24 kl was encoun tered and t he
pilot was unable to maintain control of the aircraft.
16 Aug
Private
831 1051
58
600
20
None
The weather forecast_received by the pilot predic ted the presence of low cloud along t he rout e to be f lown. Du rin g t he attempt to
return to his destination the pilot had overflown a lic ensed aerodrome but had not considered landing to await an improvement i n
the weather.
26 Aug
Commerc ial
8321064
44
2145
20
Inst rument Rat i ng 1st or C lass 1
The pilot had flown a flap less approach al the ci rcu it spacing fo r an approach with f laps extended. This resulted i n t he airc raft
bei ng high on final approach , h owever, the pi lot elected to cont inue the approach and land. The grass stri p surface was wet and
brak ing effi ciency was reduced.
01 Sep
831 1054
Comme rcial
2700
Instrumen t Rat ing Class 4
420
31
Hel icopter
The helic opter suffered a loss of t ran slat ional lift probably due to f luctuations in the prevailing w ind. In an attem pt t o recover the
lost lift t he pi lot applied excessive collect ive cont rol and overpitched the main rotors. The helicopter landed on slopi ng ground
and rolled over.
8311055
01 Sep
Ag ricu ltural Class 1
1020
17020
Commerc ial
48
Helicopter
The pi lot was dist rac ted by the person acting as a marker, who was slow to re-posi tion for the nex t swat he run. As the pilot t urned
t he aircraft to avoid t he marker th e rot o r blades st ruck the c able. T he pilot con sidered t hat he may have been furl her d istracted by
t he need to mo ni tor the spray pressure gauge, as he was expecting t he chem ical supply to become exhaus ted .
10 Sep
8321070
None
3
Private Restric ted
34
95
The pi lot had o nly limited experienc e on the ai rcraft type. Some tu rbu lence had been experienced du ring the final approac h and
the aircraf t touched down heavily before the pilot was able to adopt the correct att itu de for the land ing fl are. Go-around power
was n ot ap plied unti l after the airc raft tou ched down fo llowing the second bounce , but the nose gear s tru t had already fai led. The
propeller struck the groun d w ith full p ower sti ll appl ied .
14 Sep
Private
8311057
21
903
830
None
The vict im was fami liar with fi xed-wing ai rcraft and helicopters but had been flyin g cont inually in heli c opters for several days and
was briefed to go ahead of the aircraft to avoid the tail rotor. He was t ired and in a hurry so as not to delay the aircraft , which had
litt le time to s pare for the ret urn f light before last light.
16 Sep
Comme rcial
8311 059
38
11 874
11 600
Agricultural Class 1
The p ilot reported that he was not att empt ing to han d start t he eng ine and was only tryi n g to free the starter drive . W hen he left
the c ockpi t to tu rn the propeller he had left th e magnet o switches on and the t hrott le in the full open pos iti on. The park brake had
been applied but was not sufficient ly stron g t o rest rain the aircraft under fu ll eng ine power.
16 Sep
Student
Du ring the app roach
land ing f lare. He had
8321072
41
23
23
None
the pilot concen trated on keepi ng the aircraft aligned w ith the runway cen t rel ine and did not initiate a
li mit ed experience in crosswind landing techn iques.
20 Sep
Commerc ial
Helicopter
8341 028
38
3050
2600
None
21 Sep
8351023
In strument Rat ing Class 4
3237
2000
Commerc ial
54
The ai rcraft was fitt ed with standard s ize tyres and wheel spats. Du ring t he manoeuvri ng on the clay pan, mud accumu lated in t he
spats and preven ted the wheels from rotating freely.
24 Sep
Student
8331028
51
27
27
None
25 Sep
831 1062
Gl ider Rating
300
150
Glider
35
The pilot misjudged the speed and heigh t of t he g lider at t he commencement of the low-level f ly past. He then attempted to t urn
and land in the opposite di rect ion , but did not main tain suffic ient airspeed for t his manoeuvre.
27 Sep
8311 063
25
None
25
Student
23
The in stru ctor authorised an inex perienced s tudent to carry out solo touch and go ci rcuits in a 5 k l crosswind. On approach t he
student set th e elevator trim nose down. During the su bsequen t attempted takeoff attent ion was diverted f rom the operation o f
the ai rcraft whe n takeoff flap was selected and d irecti onal contro l of t he aircraft los t as it tu rned into wind and left t he strip.
The land ing was mad.e in fluctuating wi nd con ditions with a downwind component. The pil ot had underest imated t he length of
the s tri p, whic h was inadequ ate given the prevai ling conditi o ns.
26 Aug
Commerc ial
. Heli copter
8311052
46
x I Aviation Safety Digest 120
9650
60
Ins tru ment Ratin g 1st or Cl ass 1
A viation Safety Digest 120 I xi
I
j
�The dangers of distraction
ACCIDENTS TO AUSTRALIAN CIVIL AIRCRAFT 1983
T~e
table below details accident statistics for the period 1-01-1983 to 31 -12-1983. A comparison
with average rates for the previous three years is also provided.
Note 1: Data for 1983 is preliminary information only and may be subject to revision.
Note 2: Abbreviations used are: tot= total,
ftl =fatal,
ACC =accidents.
OLD
tot
ft/
AIRLINE
COMMUTER
CHARTER
AGRICULTURE
TRAINING
OTH . AER. WK
PRIVATE/ BUS.
GLIDING
TOTAL
Average over
previ ous 3 years
1
7
11
2
1
5
18
34
4
3
2
80
8
71
NSW
tot
ft/
1
4
16
14 *
4
1
1
7
4
6
23
1
3
6
42
4
5'
49 '
11*
100
71
V-TAS
ft/
tot
39
SA-NT
tot
ft/
3
2
2
9
13
3
33
W. AUS
tot
ft!
2
4
1
6'
13
3*
2
38
29
O!SEAS
tot
ft/
1
2
2
3
2
41
TOTAL FATAL
ACC. ACC.
1
3
17
40
26
44
134
21
4
3
5
12
286
24
261
26
31
3
(Average rounded to nearest whole number)
ROTARY
21
Included in di ssection above
2
5
3
·Denotes number of aircraft involved in accidents. Includes collisions between two aircraft on three occasions in NSW and one occasion in WA.
A feature article in Aviation Safety Digest 114 addressed
the topic of wire strikes by cropdusting aircraft. One of
the many points stressed was that of the need for
continu ous v igilance and concentration on the part of
the pilot during aer ial application operations. Quite
simply, because of the environment in which they work,
agricultural pilots cannot afford the slightest lapse of
concen tration. This truism is yet again illustrated in the
two brief bu t instructive accident su mmaries related
below. The pilot in the first accident had over 18 OOO
hours fligh t time, and th e second over 9000 hours.
*
07 Mar
0900
Cessna 182 K VH-KRI
Couta Rocks, Tas.
Non-commercial- pleasure
Smithton, Tas./Couta Rocks, Tas.
C1N, P1N
310063
After landing the pilot taxied the aircraft along a track leading to a parking area. Nearing the parking area the nosewheel
entered a wombat hole, pushing back the nose strut and buckling the firewall.
xii I Aviation Safety Digest 120
*
*
A cotton field was being sprayed under conditions
which the pilot fo und relatively easy. The only
notewor thy obstruction was a single-strand power line
which was o n a perimeter of the paddock, suspended
from p oles about 200 metres apart, and which hung
down to ab out 20 feet above ground level at mid-span.
To facilitate his task, th e pilot settled into a routine of
flying under this wire at the completion of ever y second
run.
Conditions were calm and cool, and the pilot had
sprayed this paddock on numerous occasions
previously. In his own words, it all added up to 'a dead
easy job' . Because of this he allowed h is mind to
wander on to t he next job he would be undertaking,
and also on to details relating to a personal business
ven ture on which h e intended to embark later that day .
Consequently h e om itted to descend the a ircraft on
th e penultimate run and saw the power line only when
he was alm ost on it. He dived in a n attempt to avoid
the wire but struck it with the tail fin. The complete tail
assembly was torn from the aircraft and all control was
lost. As the aircraft struck the ground the engine was
wrenched from its mountings. The airframe continued
to cartwheel for 23 metres. T he unconscious pilot was
extricated from the wreckage by the loader driver an d
marker.
*
*
*
While he was spraying a sorghum crop the pilot of an
Agwagon noticed that a component of the spraying
equipmen t was malfunctioning. He climbed a little
while he rectified the fault and then resumed his job.
Shortly afterwards the component failed again, so he
repeated his actions and was again successful.
However, when he descended to recommence
spraying, having been distracted by his problems, he
forgot about a single-strand power line which was
across his path until he had almost collided with it. His
attempt to evade the wire failed and it snagged the
rudder horn leading edge, tearing off the horn and the
rudder section above the top hinge. Fortunately,
aircraft controllability was retained and the pilot was
able to fly his damaged aircraft to the nearest suitable
aerodrome a nd land safely.
Summary
It is well understood that aerial application is an
extremely demanding exercise. As the article in Digest
114 concluded, continued safe operations largely boil
down to 'establishing a personal set of safety rules and
disciplining oneself to adhere to them at all times'. That m any
agricultural pilots have flown for many years and
thousands of hours without having a wire strike shows
that it can be done, and emphasizes the efficacy of the
simple but fundamental dictum quoted above e
Aviation Safety Digest 120 I 13
�Fatigue
Pe rhaps a more widely recognised enemy of pilots is
a ircrew fatig ue. Flying tasks can require a high degree
of skill, alertness a nd co-ordination, sometimes under
adverse conditions. Often it is necessary to complete the
most important and demanding pa rt of a task at the
end of a long a nd difficult day.
T he fatigue factor, simpl y put, results in an inability
to perform effectively. Also, it is in sidious in that an
individual may not be aware that judgment has been
impaired. The sy mptoms , however , a re apparent to the
rested observer and include the fo llowing:
•
•
•
•
•
•
Stress, fatigue
and piloting
Medical studies have established th at emotional stress
created during the day-to-day lives of people can lead to
ulcers, heart disease, family difficulties, loss of
productiviLy and possible early death . It follows .that
stress as a health factor must be of concern to pilots.
Associated with the general question of stress is the
m o re fa miliar problem of pilot fati gue. There is
evidence to suggest that individual operators and fl ying
supervisors do n o t always focus s ufficiently o n these two
problem a reas. Yet there are oft en clear indications or
symptoms that an individual is, or is likely to be,
exposed to risks arising from stress and/or fatigue.
Stress
Some of the more obvious stress-inducing events
(stressors) have already been menti~~ed above.
,
Research an alysts have produced a life event scale
which shows the relative score values of each strcsso r
(see Figure 1). By being aware of the relative impact of
these events we should be able to gua rd against loading
up o urselve; or o ur workm ates when stresses from 'life
events' already exist.
Social readjustment rating scale (incomplete)
L ife event
Death of spouse
Divorce
Marital separation
Jail term
Personal injury or illness
Marriage
R etirement
Change to different line of work
Trouble with in-laws
Trouble with boss
Change in work condi tions
Change in sleeping habits
Change in eating habits
Figure 1
14 I Aviation Safety Digest 120
Value
100
73
65
63
53
50
45
36
29
23
20
16
15
Apart from the life events, there are other fairly
readily identifiable symptoms of stress whi ch we sho uld
be able to recognise in ourselves and others:
• general irri tability o r depression
• low morale - loss of enthusiasm
• poor work habits associated with a decline in the
qua lity of work
• trembling, ne rvous twitches or ties
• insomnia, sweating, headaches
• compulsive eating o r drinking
• drug and alcohol abuse
• illness, such as ulcers, high blood pressure.
It is importa n t to note the crucia l role management
can play in creating o r alleviating stress. There is
considerable evidence from physicians and clinical
psychologists that psychologically unhealthy
relationships between subordinates and their au thority
figures can lead to emotional disability .
One of the best ways to alleviate stress in the working
environment therefore is to adopt a ma nagement style
that engenders an open, trusting a nd participative
climate. Good communication and a n open , honest
approach will do a lot to assuage stress through
com mon clear understa nding of tasks, purpose and
goals . T he way supervisors handle evaluations, in ternal
job changes, tasking a nd counselling can be either
devastating or m orale boosting. Admittedly there a re
times when tight deadl ines and operational
requirements induce stress, but such stress is to be
expected and can be managed by careful assign ment o f
tasks according to ability and equitability of the
workload . The question of managing stress is succinctly
addressed in the following quotation:
The secret of success is not lo avoid stress and thereby
endu re an un eventful boring life, for then our wealt h
would do us no good , but to learn to use our capital
wisely, to get maximal satisfaction at the lowest price.
a low frustration level
degraded co-ordination
slowness in respon se
fa ilure to recogni se er rors
carelessness
acceptan ce of low standards of accuracy.
How many of us have committed, or heard of, errors
such as wrongly set altimeters, missed altitude calls,
incorrect headings, and poor approaches followed by
dicey landings after a long and d ifficult day?
Fortunately, such errors are usually countered by our
abili ty to draw on reser ve energy to ' psych e up' and
handle stressful situations.
I t is necessary to be aware of circadian rhythms,
which explain the way in wh ich the human body
functions on a 24-hour-cycle biological clock. Any
disruption of this cycle will cause fatigue and stress.
Such primary body function s as temperature, blood
pressure, blood su gar level and haemoglobin level can
be ad versely affected . Studies show that our poorest
performance occu rs at the low point in our circ~dian
rhythm o r the time we would no rmally be sleepmg.
H ence, our worst period is fro m about 0300 to 0600
local time (Figure 2 depicts the problem graph ically). If
you are trying to land during the 0300- 0600 period
a fter a long period of duty, then don ' t expect your
j udgment and skills to be at their best . S~ch n:iatters as
previously inadequate crew rest and crossmg time zones
will lower performance even more.
insufficient sleep o r 'sleep deficit' occurs. If less than
8 hours of qual ity sleep is ob tained in any 24-hour
period, then a n accumulation o f sleep loss begi~s. The
n ature of fl ying operations is such that rest periods can
beco me fragm ented, with sleep often being scheduled
for unu sual hours. In these circumstances, it i's likely
tha t a pilot's sleep deficit will accumulate to a point
where task risk increases. Once an ind ivid ua l is into a
sleep deficit situation, con siderable time off is required
to restore the body to its normal state. Studies have
shown that, following duty times of 12-20 hours,
fatigue may ex ist for more than o~ e or two ~fays .
There a re a multitude of o ther factors whi ch cause
a ircrew fatigue in addition to those mentioned. Some of
these are age, experience level, cockpit temperature,
humidity, cabin a ltitud e and ph ysical fitness, including
the e ffects of caffeine, self-medication , alcohol a nd
smoking.· There are a few irrefutable fact s worth
keeping in mi nd when considering pushin g the fitness
a nd hygiene factors and bending such rules as ' bottle to
throttle'. Included in these are the follo wing:
• Mental alertness and stamina are increased when a n
individual is physically li t.
• If pilots do not eat properly before and during
.
flights, then a low blood sugar supply m ay result m
a nxiety , disorientation, amnesia and head aches.
• Studies and reports show that smokers are more
susceptible to fatigue and suffer from a definite
reduction in al titude tolerance.
• Alcohol causes significant cha nges in the body system
that seriously impair the perform a nce of fl ying skills.
These changes appear to rem ain longer after
drinking stops than was previously realised . Alcohol
itself and its res idual effects can remain for up to
18 hours a fter drinking .
• T he over-use (4-5 cups per day) of'coffee a fter flight
might impair adequate rest a nd contribute to
unnecessary fatigue o n the next day's fl ight.
Of course, many of these fatigue and stress factors ca n
be present simultaneously.
Comment
(+ )
Best
....
..
>
_J
u
c
0
E
.2
;;;
a..
0900
0300 0600 0900
T ime
Wor st
(-)
PSY CHOMOTOR
PERFORMANCE
Figure 2
The subj ect of pilot stress a nd fatigue is com plex a nd
often it is a struggle to maintain control over events
which may pose a threat to safe operations.
Nevertheless, pilots and operations man agers must
co ntinue to focus on these human factors if their
operations are to remain effective a nd s~fe. The idea is
not to elimina te st ress and be overly lement, but more
to allev iate unnecessary stress a nd fatigue. Those
ind ividuals associa ted with flight ope rations, e ither
actively or adm inistratively, must educate themselves
o n Lhe m any a spects of stress a nd fatigue th at heretofore
have not been sufficiently emphasized. The best counter
to the issue is to be able to recognise stress a nd fatigueinducing factors, and the ir associa ted sympto ms, early,
a nd to take remedial act ion before distress becomes a
problem •
(Adapted from Flight Com ment)
Pilots should also be aware of the phen omen on of
'sleep d eficit'. The amount of sleep required by an
individ ual varies, but in intensive fl ying operation s
sleep disturba nce occurs frequently, to the point that
Aviation Safety Digest 720 I 15
�Trapped on top
----·------------------- --
----------
___ f'-~
~
. ~~
,<
' .
~L.et:~ c~
:)
SCT
ovc
BKN
the deteriorating weather but he pressed on, remaining
VMC on top. H e arrived overhead his destination on
time but, because of the cloud, was unable to descend.
The cloud cover had become so extensive that no
alternative airstrips in the immediate vicinity were
open.
Unsure of how to tackle the difficult - and
potentially dangerous - predicament in which he had
placed himself, the pilot wisely asked Flight Service for
help. W ith assistance from the FSU and inflight
guidance from the instrument-rated p ilot of another
Cessna 182, the non-rated pilot was, after some fairly
tense moments, directed to the nearest suitable
diver sion aerodrom e, where he was able to descend
clear of cloud and land safely. It is significant that this
aerodrome was 200 kilometres away from the original
destination. As was the case with the other incident, it
seems probable that this pilot would have been in
serious trouble if help had not been readily available.
*
*
*
FORECAST CLOUD ABBREVIATIONS
SKC (sky clear)
nil
SCT (scattered)
1 to4 OKTAS
BKN (broken)
5to70KTAS
ovc
80KTAS
(overcast)
The amount of cloud predicted in a meteorological forecast is an important item for consideration
in preflight planning. While it is a factor which must be assessed carefully by all pilots, it is
particularly relevant to those who plan to file VFR flight plans.
As the Visual Flight G uide (VFG) points out ,
navigation by reference to the ground is impracticable if
an aircraft is flying over m ore than 4 oktas of cloud.
T h e VFG also details the procedure to be followed
whe n radio navigation equipment, rather than visual
fixin g, is used for navigation during a VMC flight.
Used sen sibly, this procedure obviously is relevant to
VFR flight a bove cloud. It is, however , a procedure
which n eeds to be u sed with care and common sense, as
the following accoun t of an air safety incident
illustrates.
A pilot departed an aerodrome on the east coast
planning to fl y to a destination about 100 miles inland.
The forecast seemed suita ble; although scattered to
broken cloud was predicted it was supposed to be
clearing from the west :
Once airborne the pilot found tha t the re was more
cloud than expected and that it had not yet started to
clear . In order to maintain the required heading and
remain VMC the pilot h ad to keep climbing over a
steadily increasing cloud buildup. G iven the conditions
there is little doubt that he would have been better
advised to have reversed his heading and returned to
his departure point. Eventually he found himself at
8000 feet on top of overcast conditions. When h e finally
decided it was time to turn back h e fou nd that cloud
buildups towards th e coast were now blocking his way:
his decision to divert h ad been left too late.
At this stage the pilot started to become uncertain of
16 I Aviation Safety Digest 120
his position ; while in order to remain VMC he had to
climb further , initially to 10 OOO fee t and then shortly
afterwards to 12 OOO feet. W ith the situ ation
threatening to get dangerously out of hand, the p ilot
very sen si bly contacted Air Traffic Control and
requested assistance. His aircraft was quickly identified
on radar and he was given his position and a course to
fly to reach a clear area.
The pilot deserves credit for calling for help before
matters got even worse . Hopefully, when he was safely
back on the ground, h e derived the full value from this
exp erience by reflecting on what migh t have happened
h ad he not been within range o f ATC radar when he
trapped himself on top of the overcast conditions.
This particular incident highlights only one of the
problems - namely, that of getting lost - which a
pilot without an instrument rating who attempts to fl y
VFR on top of broken or overcast cloud may
encounter. Other problems can arise. For example, a
pilot who successfully navigates from A to B might have
done only half the job: he still has to be a ble to descend
safely to land at B when h e arrives. Consider the
following incident.
A Cessna 182 pilot was flying to a destination sited at
the foot of a range of hills. En route navigation posed
few difficulties, although cloud beneath the aircr aft
steadily increased and the forecast for the destination
indicated that condit ions were marginal fo r VFR
operations. The pilot began to feel slightly uneasy about
Several points need to be raised concerning VFR flight
on top of cloud. The firs t is that there is nothing
inherently wrong with the practice. Indeed, it may well
be good airmanship to fly above scattered cloud rather
than beneath it in order to take advantage of smoother
air, improved visibility or more favourable winds.
Certain basic precautions must, however, be observed .
It is incumbent upon the pilot to ensure that:
• the stipulated separation from cloud for VFR flight is
maintained;
• weather conditions are stable or improving; and
• he remains alert for any changes and takes timely
action if the clouds start to increase and the 'sucker
holes' start to shrin k.
The biggest mistake a pilot can make when fl ying
VFR on top is to wait too long before descending or
making a 180-degree turn (one of aviation 's oldest
safety devices) when deteriorating conditions demand
action .
The second point addresses that most crucial aspect
of safe piloting, preflight planning. If VFR flight above
scattered cloud is being considered, the following
procedures must be observed during planning:
• Obtain a meteorological forecast and briefing for all
phases of your flight, and make a thorough.
assessment of that information.
• Do not plan for or attempt VFR flight when weather
conditions are close to VFR minima. Remember
that, given the right ingredients, those conditions can
deteriorate quickly.
• Select a cruise altitude which will be compatible with
terrain and cloud separation requirements.
• Consider the weather in relation to such factors as
the route and your aircraft's capabilities and then
allow a margin of safety commensurate with your
experience level.
• While en route, monitor the weather not only
visually, but also through such sources as FSUs,
aerodrome weather reports, aircraft weather reports
and VOLMET.
Finally, the question arises, what should you do if, as
a pilot authorised only for VMC fligh t, you find
yourself trapped on top of an overcast?
The primary requirement is to make every effort to
remain VMC and to let someone know of your
problem as soon as possible. Air traffic controllers and
flight service officers are trained in assisting pilots in
distress, so give them a chance to help you before it is
too late. If you experience difficulties in making radio
contact, climbing will both increase VHF range and
improve the chances of ground radar detection. I t may
also be prudent to conserve fuel by using an economical
or maximu m endurance engine power setting.
*
*
*
As is usual in matters of flying safety, prevention is a
much better approach to this problem than the cure: if
you are a pilot rated only for VMC operations, then
avoid flying on top of overcast conditions •
In brief
After a short thermalling flight the pilot of a Blanik
L1 3 glider returned for landing. Because there were
several oth er pilots waiting for fligh ts, he deliberately
aimed to land short to reduce the retrieve time. The
approach unhappily turned out to be too short. At
about 150 m etres from a fence delineating the
airfield boundary, airspeed started to decrease
quickly . As h e was intending to land short, the pilot
was by t hat stage relatively low and did not have
speed to tr ade for height. He tried to u tilise ground
effect to stretch the glide, but only succeeded in
hitt ing the fence, causing substantial damage to the
glider's tailplane.
While the prime cause of the accident was the
poor j udgment of the pilot in attempting to land
short, the fact that there was an upslope on the
approach to the runway probably was a contributory
factor, causing the pilot to fly lower on final
approach than he should have. (See Aviation Safety
Digest 111 for an article on visual illusions caused by
sloping approach terrain.)
•
*
•
While climbing th rough 600 feet a helicopter pilot
experienced loss of directional control. Suspecting
tail rotor failure or separation, the pilot put the
aircraft into an autorotation. The helicopter was
damaged when it struck the ground at a high rate of
descent. The initial investigation showed that a strap
normally used to secure cargo had flown out of the
cabin area throu gh an open door and become
entangled with the tail rotor •
Aviation Safety Digest 120 I 17
�Reducing the risk
release checks with the tow rope , a Blanik L13 glider
was hooked on and takeoff commenced. A flock of
hawks had previously been noticed near the runway,
but the birds had vacated the immediate area when full
engine power had been applied.
H owever, at between 150-200 feet AGL several birds
flew into the aircraft's flight path and contact was
unavoidable. The pilot noticed one hawk had lodged in
the 'V' formed by the leading edge of the port wing
and wing strut. The glider was immediately released
and it landed safely straight ahead.
The Callair started to turn to the left by itself, and
when the pilot tried to correct this he found that the
ailerons were ineffective. He was able to keep the wings
level by applying right rudder but he could t1ot prevent
the aircraft from tracking to the left.
By this stage the aircraft happened to be positioned
on downwind. A quick glance at the ASI showed 100
Birdstrikes are a potential hazard facing all pilots. Strikes involving large birds and light aircraft can
be particularly dangerous and costly, as the following three accounts of accidents show.
A Piper Aztec on a charter flight was established in the
cruise at 2500 feet and with the autopilot engaged. The
pilot was checking his DME indicator prior to making
an inbound call at 20 miles, which necessitated looking
down and to the right toward s the centre of the panel.
His right hand was across his face scratching his left
temple.
Suddenly there was a loud explosion. T he pilot found
himself lying across the right-hand seat, bleeding
profusely from the head. His right hand was also
severely lacerated although he did not realise this at the
time. He pulled himself up and noticed that the
windscreen was missing and that a large bird was
wedged in the top left-hand corner of the windscreen
frame.
After checking that the aircraft was still straight and
level at 2500 feet (approximately 1500 feet AGL), he
attempted a Mayday call to an aircraft from the same
company which he knew was about 15 miles behind.
The headset had been knocked from his head into the
rear of the cabin and was retrieved by pulling on the
cord. Another Mayday call was transmitted.
18 I Aviation Safety Digest 120
At this stage the pilot realised that his right hand was
almost unusable. Fortunately his destination was in
sight.
H e heard what he thought was an acknowledgement
to his Mayday and set himself up for a straight-in
approach. He was finding it difficult to see out of his
left eye, but accomplished a normal landing after
carrying out the primary functions with his left hand.
Although the pilot h ad continued to transmit his
intentions throughout, neither the Mayday nor other
transmissions were heard by other aircraft due to his
microphone being full of blood.
The remains of the bird, a Wedge-tailed Eagle,
weighed about 5 kg. The cost of repairs and loss of
incom e resulting from this strike totalled approximately
$ 14 500.
*
•
...........
*
The pilot of an A9A Callair was conducting glidertowing operations. After completing normal safety
Aviation Safety Digest 120 I 19
�BIRDSTRlliES
Reducing the risk
knots. The pilot attempted to turn base by allowing the
left wing to drop about 15 degrees and reducing power,
but found he then had insufficient control over his
machine. Full power was applied but this only increased
the angle of bank, tightening the turn .
The pilot realised a crash into the trees below was
inevitable. He held the aircraft in a 15 degree port wing
down attitude with no power and full right rudder until
striking the ground. H e completed most emergency
checks but did not have time to turn off the fuel.
On impact, flames shot up into the cabin from
beneath the rudder p edals. The pilot freed himself from
the aircraft after which both fuel tanks, which were
approximately two-thirds full of 100/130 avgas,
exploded.
The pilot escaped with only a few minor injuries.
The aircraft, which was valued at $18 500 , was
destroyed.
•
*
•
The pilot of a Cessna 310 was engaged in prawn
spotting operations. H e had been cruising as low as 600
feet ASL a nd was commencing a climb when he went
through a flock of birds. As h e approached 700 feet
ASL one of the birds passed through the starboard side
of the windscreen and struck the observer in the chest.
The bird was identified as a Lesser Frigatebird.
The pilot reported that the return flight to home base
was noisy and uncomfortable with 'blood and guts over
everything'. Fortunately there were no control
difficulties.
The observer suffered a cut hand and a bruised
chest. There were no other injuries.
The total cost of repairs and loss of income due to
the period of unserviceability of the aircraft was
estimated to be in excess of $10 OOO .
•
•
•
Each of the pilots involved in these accidents was
fortunate to escape serious injury. Indeed, the pilot who
had his hand across his face immediately before impact
may have been saved by that action. It was possible
that his aircraft, which had full tanks of fuel, would
have continued on autopilot into the Simpson Desert
had he lost consciousness.
Because birds are more com mon close to the ground,
most birdstrikes are likely to occur in the vicinity of
airports. Over 80 per cent of strikes occur during the
takeoff, climb, final approach and la nding phases of
flight. Approximately 22 per cent of reported strikes are
windshield strikes. On average, 10 per cent of reported
strikes result in damage to the aircraft.
Birdstrikes to aircraft while cruising are much less
frequent. However, th e likelihood of sustaining serious
damage and injury from the impact of such a strike is
greater due to the higher speeds involved.
When a 2 kg bird strikes an aircraft travelling at 135
knots it exerts a 3.8 tonne (37.28 kilonewtons) force on
a saucer-sized area of the aircraft 's frame or engine. If
the aircraft is travelling at 170 knots the force is
equivalent to 15 tonnes ( 147. 15 kilonewtons) and at 540
20 I Aviation Safety Digest 120
knots, 60 tonnes (588 .6 kilonewtons). Even though light
aircraft are unable to travel a t this latter speed, they
are, nevertheless, susceptible to severe damage from the
impact forces of a birdstrike which can result in
windshield breakage, control jamming, airframe
distortion and control surface breakage.
Whereas action is taken on and around aerodromes
to reduce the likelihood of encountering birds, little can
be done to assist aircraft while cruising. This
responsibility must, therefore, rest with the pilot. The
following points, which may help to reduce the
p ossibility or severity of a birdstrike, should be kept in
mind:
• Maintain a good lookout, particularly when flying at
low level.
• Be aware that ma ny birds that feed and roost in
flocks such as ibis, galahs and sta rlings may fly
between their roosting areas and feeding areas
during the early morning and evening.
• W atch for indications of thermals and updrafts and if
possible avoid areas where they may occur . Birds of
prey and large water birds tend to soar on rising
currents of air and can be encountered at heights up
to 20 OOO feet AGL.
• Avoid flying below 1500 feet AGL in the vicinity of
abattoirs, swamps, wooded hilly a reas, garbage
dumps or any place that is likely to be attractive to
birds.
• It is preferable not to try to avo id a bird by fl ying
under it. It is usually the bird's n atural inclination to
avoid a collision by diving or sideslipping to Jose
altitude.
• Should a strike appear imminent, try to m aintain
straight and level flight rather than risk control
difficulties due to the distortion of the airframe by a
birdstrike or over-stressing of the aircraft during last
minute evasive action . Also, you should try to duck
below the line of the instrument panel if there is a
possibility that the bird may strike the windscreen.
• Advise ATC, Flight Service or 'all stations ', as
appropriate, if you are aware of bird activity on or
around an aerodrome so that other aircraft may be
alerted, especially if Regular Public Transport
operations are involved. This is pa rticularly
important at large airports wh ere the control tower
may be remote from runway a pproach and depa rture
p aths which might make it difficult for controllers to
visually detect smaller flocks of birds.
• Avoid, wherever possible, attempting to take off or
land when there are birds on or around the run way.
• Finally, report all birdstrikes. Apa rt from being a
statutory requirement , accurate birdstrike reporting
en ables the intensity and nature of bird hazards at a
particular loca tion to be assessed so that action can
be taken to control those hazards. One of the
accidents described above occurred near Batchelor in
the Northern T erritory. It was the second birdstrike
to h ave been reported there in 12 years. The third
reported strike occurred one week later and resulted
in the shattering of a helicopter canopy. If all the
other strikes which have doubtless been sustained at
Batchelor over th e years had been reported, action
could have been taken to prevent the loss of an
aircraft and danger to life •
Inadequate periodic inspections
On downwind for a night landing, the pilot of a Piper
PA31 Navajo selected the landing gear down. The nose
wheel and port main wheel green lights illuminated but
the starboard main wheel red 'gear unlocked' light
remained on. Climbing to 2000 feet to clear the circuit
area, the pilot attempted to rectify the problem by
recycling the gear several times, but to no avail. He
then tried to lower the gear using the emergency system
but this too was unsu ccessful.
An airborne inspection by a nother aircraft, which
was able to illuminate the underside of the Navajo with
its landing light, confirmed that the port main wheel
and nose wheel were both d own, and that the starboard
main wheel was partially down a nd appeared jammed.
The Navajo pilot then attempted to dislodge the
jammed wheel through the application of g forces to the
aircraft, but had no success.
Accepting that he was committed to a gear-up
landing, the pilot retracted the gear and, with the full
assistance of the emergency services and Air Traffic
Control, carefully planned his landing. This was
effected calmly and competently and, while the aircraft
sustained a fair amount of damage, both occupants
were uninjured.
Analysis
The aircraft was hoisted by crane the following morning
and put on j acks for examination. Inspection of the
starboard undercarriage wheel bay a rea revealed that
the forward hinge on the inner gear door h ad broken
near the centre of the arm (see photograph). This had
prevented the door from operating correctly, so that
when the pilot selected the undercarriage down the
wheel and the door h ad become jammed. R etraction
tests revealed no other fault with the system .
The possibility of cracking occurring in the PA31 's
main landing gear inboard door hinges had been
recognised by the Piper Aircraft Corporation following
field reports. Accordingly the Corporation had issued a
Service Bulletin on the subject which detailed the
inspection procedure. This procedure h ad been
endorsed by the Department of Aviation .
It was apparent from an inspection of the Navajo's
door hinges that this particular inspection had not been
completed properly. T he Service Bulletin stipulated that
the hinges had to be inspected for cracking using the
Dye Penetrant Method, before which all paint had to
be removed from the inspection area. The broken hinge
removed from the starboard main landing gear of the
Navajo still had the original zin c chromate primer on it
- in other words, the paint had not been removed.
Thus, any Dye Penetrant Inspection, if in fact
conducted, would have been invalid.
This inspection was to be carried out every 100 hours
time in service unless the hinge had been replaced by
an acceptable replacement part. Although several
periodic inspections had been certified as having been
completed on this aircraft since the issu e of the Service
Bulletin and the applicable Departmental A irworthiness
D irective, the condition of the door hinge did not
support those certifications.
Comment
Readers should not need any conclusions to be drawn
by Aviation Safety Digest on this matter. The importance
to flight safety of thorough and reliable maintenance is
self-evident. In this accident the pilot and his passenger
were lucky •
Aviation Safety Digest 120 I 21
�~ea4e-t
The importance of preflights
My son and I both hold unrestricted PPLs with about
300 and 400 hours respectively. We own a Cessna 172
which is sometimes parked in the open at a country
airport. At the time of the o ccurrence described below iL
had flown about 20 hours following a major insp ection
three months previously.
I had always considered that m y p refli ghL inspections
were careful and I had also spent as much time as
possible on owner maintenance . However, a recent
incident has given me a new perspective on prefl ight
inspections.
*
*
*
We flew to anoLher country aerodrome after doing a
'complete ' preflight ch eck, including weight and
balance calculat ions. Landing weights were: two pilots
294 lb, two rear seat passengers 276 lb, rear luggage 30
lb, fuel 112 lb. All well within safety limits .
On wh a t app eared a n ormal approach with full flap
into a steady wind we felt the ta il area touch the
runway. The a ircraft had a high nose up attitude and
the stall warn ing just began to sound at touchdown.
Examination showed slight scratching on the ta il tiedown ring , no other damage. We co uld not come up
with an explanatio n as it had never happened befor e.
Not being satisfied with an unusual experience which
we could not explain, I made a complete check of the
aircraft. I removed inspectio n plates and the panel from
the lu ggage area to inspect the rear inside fuselage . I
found that there was about 40 mm of water trapped
between the rear bulkheads at the rear of the fuselage.
The drain holes had been blocked with dirt a nd paint
o verspray . C learing the drains allowed a considerable
a mo un t of water to flow out.
Whether Lhis weight of water caused an out-ofbalance centre of gr avity I am not able to say.
However, one can imagine how much worse this would
h ave been if we had been operating at closer to gross
weight lim its. The ai rcraft is perfec tly normal and
subsequent landings in the same configuration have all
been normal .
My preflight inspections will be even more careful in
future.
*
*
*
Comment
When carrying out preflights, pilots should rem ember
that special circumstances may require special
inspections . For example , if your a ircraft is parked
o utside for long periods and used infrequently, the n , m
addition to checking all the items listed in the pilot's
ha ndbook, extra attention will need to be paid to such
items as corrosion, water and o ther types of
contamination , bird a nd insect nesting, and so on .
It is difficult to over-emphasise the importance of
·preflight inspections. Countless potential accidents have
22 I Aviation Safety Digest 120
been averted by the discover y of fa ulLs during
preflighLs. Un happily the reverse is a lso true. One of
the most graphic exam ples of this was a fatal accident
involving a PA32, which was the subject of a Summary
Report issued by the Bureau of Air Safety
Investigation.
I t was apparen t from wreckage distribution and
witness statements that the Cherokee had broken up in
fli ght. Investigat ion resulted in the d iscovery of fa tigue
cracking in the stabilator. It seems probable that this
cracking eventually affected the skin panel to the extent
that the skin disrupted airflow over Lhe right stabilator .
This then led to a loss of control , and eventually the
infligh t breakup of the aircraft. The following
photograph shows the catastrophic consequences.
In detailing the factors relevan t to the accident, the
BASI report m ade reference to the fatigue crack as
follows: 'Although the crack was not located in an easily visible
position it should have been detectable in previous routine
maintenance and preflight inspections '. The failure to detect
the crack cost the pilot and his p assenger their lives .
As a final though t on prefl ights gen erally , pilots m u st
always resist any pressures to 'abbrevia te' this crucial
check. The temptation to rush through a preflight
inspection or to take a shor t-cut is exp erienced sooner
or later by all pilots: when we're running late the
preflight seem s a natural ' target' for saving time . But to
do so is n ever worth the r isk. It is better to spend a few
minutes extra on the ground than to realise - at the
possible expen se of your life - in the air that a vital
preflight ch eck h as been omitted e
�
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1984
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�Contents
En route mid-air collisions:
how to avoid them
3 En route mid-air collisions: how to avoid
them
7 Fasten your seat belts
A loose seat belt hanging outside a closed cockpit door
can produce alarming inflight disturbances.
8 Action and reaction
An inadvertent wheels-up landing highlights the
importance of a disciplined approach to completing
checklists.
10 lnflight vibration
Reports of recurring vibrations in an aerobatic aircraft
failed to produce a thorough investigation from the
operating organisation's maintenance and flying
supervisors.
11
Flying with unserviceabilities
It would be unrealistic to state categorically that pilots
should never fly aircraft which have an unserviceability
of some kind. However, certain types of defects should
never be accepted: those affecting engines and
airframes fall into this category.
12 Reader contribution: spontaneous
combustion
13 Flying your homebuilt
After spending eighteen months constructing a
Vari·Eze, a pilot was killed on his first flight in the
aircraft. The pilot's recent and on-type experience were
minimal and this was assessed as being a major causal
factor in the accident.
15 Use your warning systems
After takeoff, the crew of a Cessna Citation noticed
that the right-hand nose locker door was open. The
door and a 3-kilogram bag subsequently fell from the
aircraft. The 'door unlocked' warning light had been
deselected during pre-start checks.
16 Human factors
World-wide statistics indicate that between 70 to 80
per cent of aircraft accidents involve human
performance failure as a significant causal factor.
19 Who is in control?
Light aircraft pilots almost always operate as single
pilots and rarely receive any formal training in crew
co-operation. When two such pilots do fly together and
start 'helping' each other on an informal basis, the
potential for confusion is very real.
20
Become a weather-wise pilot
22
Fuel metering systems for reciprocating
engines
Cover
The cover design, by Leo Di Rago, from the Department of
Aviation's Graphic Design Section, depicts the movement of
flight through space (horizontally) and time (vertically).
Images are the Cairns Birdwing Butterfly, the Sulphurcrested Cockatoo, the Qantas DH86 and the Qantas 747SP.
2 I Aviation Safety Digest 119
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It is distributed tree of charge to
Australian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Australian civil aviation.
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or wishing to notify a change of address should write to:
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 18390, Melbourne, Vic. 3001.
Aviation Safety Digest is also available on subscription from
the Australian Government Publishing Service. Inquiries and
notifications of change of address should be directed to:
Mail Order Sales,
Australian Government Publishing Service,
G.P.O. Box 84, Canberra, ACT 2601
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Reader contributions and correspondence on articles should
be addressed to:
The Director,
Bureau of Air Safety Investigation,
P.O. Box 367,
Canberra City, ACT 2601.
© Commonwealth of Australia 1984
ISSN 0045-1207
R83/247 Cat. No. 83 1533 8
Printed by Ambassador Press Pty. Ltd.
51 Good Street, Granville, N.S. W. 2142.
Pilots co uld be excused for perhaps th inking that the
likelihood of a mi d-air collision in Australia is remote:
there is a lot of sky out there and ai rcraft a re relatively
small , so the chances of two being in the same place at
the same tim e wou ld seem to be minuscule . Yet the
statistics show that th is is not the case.
In the two-year period preceding the preparation of
this ar ticle over 60 occurrences of reduced separation
were reported. There were doubtless more which went
unrepo rted because pilots remained blissfully unaware
of the proximi ty of other aircraft.
Man y of these incidents occurred in the circuit area,
where pilots should have had an acute awareness of t he
position of a ll traffic at all times .
O n the other hand, 16 of the incidents involved
a ircraft wh ich were established in an en route cruise.
Gi ven that there indeed is a lot of sky out there, there
is often a n understan dable tendency during the cruise
to be less assiduous in maintaining a lookout. I t is
therefore interesting to note that in almost all of these
16 incidents, the aircraft involved passed so close to
each other that either one or both pilots had to initiate
evasive act ion to avoid a collision .
This a rticle a ddresses the issue of detecting other
aircraft durin g an en route cruise by examining some of
the physical , physiological and psychological problems
of ' lookout' or visual search.
Relative motion
If two a ircraft a re on a collision course and these
a ircraft are flyin g o n constant headings at constant
horizontal and vertical speeds, then each a ircraft has a
constant relative bearing to the other right up until the
mome nt of impact . Figure 1 makes this clear. E ven
though aircraft A is goin g twice as fast as a ircraft B,
their relative bearings are constant. T he effect of this,
of cou rse, is tha t if you are going to collide with
a nother a ircraft , then that aircraft has no apparent
motion with respect to you and will stay at exactly the
same poin t on your windscreen until you hit it; in other
words, it will in man y respects behave in the same way
as a fl y squashed o n the outside of the windscreen .
This ab se nce of any r elative motion is important
from the poin t of view o f detecting the other aircraft
because most of the retina (the sen sitive layers of cells
at the back o f the eye wh ich turn light into nerve
impu lses to the brain) is wired up to be especially
sensitive to the detectio n of small movements. I t is not
hard to imagine why th is has evolved to be so. If you
a nd your fellow cavemen were sitting aro und the campfire mun ching your mammoth steak you would nol
need to have your a tten tion drawn to the woods while
they were still, but even a small movemen t could have
signalled danger. Apart from this physiological reason
for mov ing targets being easie r to detect than stationary
IMPACT
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Figure 1. Constant relative bearing equals collision risk.
ones there is probably a psychological reason as well,
and this is that the experien ced pilot will have learned
to use movement as a cue to detection for the simple
reason that all the aircraft he has ever seen will have
had some relative movement wit h respect to him unless he is one of those pilots who has had to take real
evasive action to avoid a collision.
So, the relative motion problem is a very real one
and can be summarised by saying th at motion is a good
cu e to detection, pilots probably learn to use it, and all
aircraft possess som e relative motion except fo r the odd
ones that you are likely to bump into (which is a bit of
a shame really - much b etter if it were the other way
round).
Time, distance and size
Some pilots may wish to a rgue that while the
information on relative m otion may be true it does not
really explain how mid-airs occur: if you are going to
h it another aircraft it must look as big as a barn door
before you collide with it; whether it appears to be
moving or not is, to put it mildly, of academic interest
only.
To answer this point, look at Figure 2 to see j ust how
a n oncoming aircra ft appears to get larger as it gets
closer. It is roughly true to say that the apparent size of
an oncoming a ircraft (i.e. the an gle which it subtends at
your eye) doubles with each halving of that aircraft 's
Aviation Safety Digest 119 I 3
�range. Imagine the case in which a GA aircraft and a
military jet are approaching each o ther head-on at
speeds of 150 knots and 450 knots respectively ~ a
closing speed of 600 knots. At about twenty seconds
before impact. the two aircraft might be about
6000 m etres apart and each will present a target to the
other of only around a sixteenth of a degree. Ten
seconds from impact the distance will have halved and
the target size will have increased to all of an eighth of
a d egree ; at five secon ds the size will have again
doubled but is still only about a quarter of a degree.
In other words, the oncoming aircraft remains
extremely small until very, very late, and then it
suddenly expands into something that tips the
windscreen. These abstract calculations match up with
the accounts of many pilots who have had mid-airs or
near misses: they ofte n describe themselves as having
maintained a good lookout, then diverted their
attention inside the cockpit for two or three seconds to
complete some checks, only to look up and be horrified
to find that the way ahead was full of aeroplane. As
reaction time is usually two seconds or more this
amoun ts to a situation pregnant with danger.
1.00
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Na s al
Temporal
Degree s eccentric from the fovea
Figure 3. The variation of visual acuity at retinal sites
eccentric to the fovea. The acuity at 5 degrees to the fovea
is only one-quarter that at the fovea.
3 sec/ Yi
0
Visual acuity
1.5 sec/ 1°
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0.75 sec/ 2°
I
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0.38 sec~~:/!._L
0.1 sec/ very big indeed
-----------------
------
Figure 2. Time to impact and ang ular size of oncoming
aircraft.
Some readers m ay still not be convinced that there is
any perceptual problem in seeing other aircraft and
might argue - with some justification - that although,
for example , a quarter of a degree may sound small, it
is act ually a reasonably large target (it equates roughly
to the size of a 20-cent coin viewed at a distance of
about six metres) to miss completely, and that anyone
keepi ng a good lookout should not really miss it. T here
is an element of truth in such an analysis, but it really
hinges on what is mean t by a good lookout, a nd this
again bears some psychophysiological comment.
The first point to be made is that the retina is not
equally sensitive over all its surface. Figure 3 shows that
it is only in a small, central area of ret ina (the fovea)
that visual acuity is good. Even at very small a ngular
depar tu res from this central area acuity drops off
alarmingly to a small fraction of the central acuity. This
does not cau se ahy problems in everyday life because
we can always use the central part of the retina to
investigate a nything that we are interested in and use
the rest of the retina to 'fill in' the rest of the world
(and attract our attention to anything interestin g out
there), but it does mean that if we are condu cting a
visual search for a small target , and the object of our
search does not happen ever to fall on t he foveal area,
then we are extremely unlikely to see it. This is
especially true, as noted at the beginning of this article,
if the target has no relative movement. It is, of course,
this unequal distribution of acuity over the retina wh ich
produces results su ch as those shown in Figure 4. In
this experiment subjects were required to detect the
presence of a D ougla s D C3 (not a small target) at three
different ranges and at differing locations on the retina.
I t is clear that the sub_rects' chances of spotting the
a ircraft dramatically mirror the sensitivity of the retina.
Many pilots will have experienced similar effects; it is
a common experience to spot another aircraft, look
away for a few moments, and then look back to the
area of sky where it was but be unable to see it again
because this time the aircraft's image just does not
happen to la nd on the right bit of the retina.
Sometimes, though, the aircraft will appear to pop up
from nowhere as it is acquired in the r ight place.
Lookout and scanning
Accepting the comments presented thus far, the
question now arises of how best to move the eye over
the external world in order to maximise the chances of
detecting aircraft out there.
Aviation Safety Digest 119 1 5
�Some pilots be lieve that the best way of searching is
to move the eyes in a smooth, continuous way over the
area of interest. Unfortunately, it is impossible to move
the eye in such a smooth , continuous move~ent unless
there is something out in the world also movmg
smoothly which the eye can track. In the absence of .
such a moving stimulus, the eye can be moved onl y m
fast jerks (called saccades) with interpos~d. rests .. What
is more, it is only during the rests that 1t 1s possible to
see anything. You can easily demonstrate the saccades
to yourself by trying to move your eye sm oothly around
your room: p ay careful attention to wh at you a re dom g
and it will become apparent that actually you are
m oving your eye in jerks. However , if you ~old up
your finger in front of your face a_nd move 1t ~bout ,
you can track it smoothly and_easily. Alte_rnat1vely,
watch someone else's eyes whilst he does It .
So when searching an empty sky the eye does not
mov: smoothly but j e rks about. There is some good
evidence to suggest that if you are conduc.tin? a search
it does no good to prolong the rests: that 1s, 1f you are
going to see something in one of the rests, you will see
it straight away and it does no good t~ !~ave your eye
h an ging around in the same place - 1t JUSt wastes .
time. Thus, in experimental situations, the people with
the best detection scores were those with the highest
frequency of eye movem ents. Those people who
.
thought perhaps that th ey were m aking slow m ethodical
searches were in fact losing out.
The last point to m ake about visual searches is _that
of where to look. It is possible th at you could colhde
with an aircraft that was descending (in which case you
should have seen it silhouetted against the sky) or
climbing (in which case it should hav~ been seen
against the ground). In the first ca~e 1t pr?bab~y does
not matter much what colour the aircraft is pa mted, but
in the latter case it m atters a lot. Australian GA and
RPT aircraft gen erally show up fairly well again~t the
countryside, although this does of ~ourse vary w~th the
aircraft paint schem e and the terram . The effectiveness
6}asten your seat
of mil itary cam ouflage on low-flyin g aircraft, on the
other ha nd, has to be not seen to be believed.
H owever, it is most likely tha t you will bump into
anothe r aircraft that is level with you, for in this case
the othe r aircraft will (at low to moderate altitudes) be
between you and the ho rizon and will present to you its
least conspicuous aspect, i.e. you will prob~bly b~
viewing it from the front or side and . th~ wmgs will
effectively have disappeared . So, agam 1t looks as
thou gh all the factors con spire to make the most
threatening possibili ty the least easy to detect .
llelts
Conclusion
The final , crucial question is whether a ll this actu al_ly .
results in any useful ad vice. The first important pomt is
that pilots should unde rstand what they are actually
doing when they sear ch th e sky - and if you have read
this article up to here you should now be m that happy
sit ua tion . There are a few more concrete tips that may
be worth remembering. They will not guarantee tha t
you will not have a mid-air, but if you_follow_ t.hem.
your chances of picking up that potential collIS1on n sk
will be considera bly enhan ced .
.
.
•
R emember that the aircraft you are gomg to collide
with is the one th at appears to be stuck in the same
place on the windscreen - if it moves •. yo~ wil!
miss it (but take positive avoidance action JUSt m
case).
•
R emember that you are looking for a small target
that gets rapidly bigger only when it is too la te to
be avoided. It can easily take two seconds or more
to a ppreciate the situa tion , make a r~spo~se and get
your aircraft to ch ange cou~se, so mm11:n1se the
time spent with your head m the cockpit.
.
•
C oncentrate your sear ch in the area of m ost likely
conflict, which , in m a ny situations, will m ean along
the horizon, looking for those aircraft at the sam e
level as you .
•
Do not imagine tha t you can make a sm~oth,
continuous search . Keep your eyes scannin g the
world in quick movem ents •
Adapted f rom Air Clues
DOUGLAS
DC-3
In brie_f
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An agricultural application aircraft was carrying out
weedicide spraying at a height of about 15-20 fe~t
AGL. After a spray run from east to west, the pilot
commenced a procedure turn over an adjacent .
paddock. During the turn he decided to c~ up his
loader driver who was en route to another JOb.
~
To do tilis, it was necessary for ~the pilot to re~ove
a headset plug from the jack point and replace this
with the p1ug for his helmet headphones. The
jackpointwas above and behind hi~ left shoulder.
Without climbing to increase terram clearance, ~e
pilot turned in his seat to transfer the plugs, which
apparently caused him inadvertently t~ relea~e back
pressure on the control colu?1-°. '[he right wmg
struck the ground and the atrcraft cartwhe~I:~ before :
coming to rest about 100 metres from the m1t1al
·
impact point •
··
%
0.2
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10
8
6
4
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2
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0 DEGREES
8
10
Loose seat belts can produce alarming inflight
disturbances, as two Cessna 150 pilo ts found out. It is
because of this that aircraft checklists invariably include
the requirem ent for seat belts a nd shoulder harnesses to
be checked on two occasions : once during the Before
Starting list a nd again during the Before Takeoff list.
Some aircraft m a nufacturers also adopt the procedure
- which should be observed regardless of aircraft typ e
or make - of placarding aircr aft to advise pilots that
all seat belts not in use should be fastened and
tightened, to preve nt them flapping a bout in the cockpit
during flight or inadvertently becoming trapped outside
a closed cockpit door.
The incidents
Almost immedia tely after becoming airborne , the pilot
reported hearing 'very loud, strange noises' . He turned
back straight away and landed on an unserviceable
grass area adjacent to the sealed runway he had u sed
for takeoff. Fortunately the aircraft was not damaged .
The source of the noise was found to be the end of a
seat belt which was hanging outside the closed cockpit
door.
In the second incident, the C essn a was cruising a t
2000 feet when a ' loud knockin g noise' developed in the
aircraft. The pilot later described the sound as being
similar to a major component failing in the engine. To
turn to the pilot 's report: ' On hea ring the noise I
immediately prepared for a forced landing, and after
going through the checks transmitted a Mayday. After
further checks of the engine and airfra me I noticed tha t
although noisy , the engine seem ed ser viceable. I then
found tha t approximately one-half of the passenger seat
belt was outside the closed cockpit door. A ssuming this
was ca using the knocking sound I retrieved it and the
noise ceased. '
Comment
Given that both pilots believed they were expe riencing
serious problem s, most probably associated with an
engine malfunction, then their initial actions were
sensible a nd justifia ble. However, the fact was tha t
neither was faced with an emergen cy. On the contrary ,
because of the ir inadequate Before Sta rting and Before
T akeoff Checks, each had set himself up to take
precipitate action unnecessarily , action which may well
have resulted in far more serious consequences. The
lesson a nd the message are loud and clear .
As a final comment, note that the pilot who retrieved
the seat belt did so in straight and level flight at 2000
feet. This is p erfectly safe as long as you en sure that
ever ything in the cockpit - including p assengers - is
secure beforehand . It could be most awkward if flight
plans, maps, FISCOMS, etc. , disappeared out the
door.
In the incident cited the pilot dealt with the matter
sensibly . H owever , there have been occasion s where a
knocking n oise associated with loose objects outside the
a ircraft, or where a door has popped open during
ta keoff, have led a pilot to become dangerously
distracted from his primary job - flying the aircraft
safely. A trapped seat belt or an open door is most
unlikely to constitute a major flight safety hazard. If
you find yourself in this situation , attend to it when you
are in a position to do so safely •
Ah-hem ...
This story is going the rounds a t an overseas airport where an airline has its new autoland fitted in va rious
stages to its aircraft:.
.
Technical Log entry from pilot: ' Autoland earned out. The aircraft landed very firmly and well to the left
of centre-line. Most unsatisfactory .'
Engineer's entry: ' Autola nd not fitted to this aircraft . . ' •
Figure 4. Probability of detection as a function of
eccentricity from point of fixation at various ranges.
6 / Aviation Safety Digest 119
Aviation Safety Digest 119 I 7
�Action and reaction
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Sir Isaac Newton once said something to the effect
that for every action there is an equal and opposite
reaction. A practical manifestation of this particular
law of motion is apparent every time an aircraft
flies . Obviously, propulsion is a matter of
fundamental importance to all pilots of heavierthan-air machines. Also important, but
unfortunately sometimes neglected, is another
action/reaction relationship in flying - that which
takes place in the cockpit during the completion of a
checklist. The following accident, describing an
inadvertent wheels-up landing, highlights the
importance of a disciplined approach to completing
checklists.
On arrival in the circuit area, the pilot extended two
stages of flap a nd m oved the landing gear selector to
what h e thought was the DOWN position. He was at
the same time trying to cancel his SARWATCH on the
HF radio and did not check the undercarriage indicator
lights. In other words, the pilot had made the mistake
of interrupting his checklist, and failed to confirm that
the action required - selection of the gear down was accompanied by the appropriate reaction, which in
this case should have been the actual extension of the
undercarriage, accompanied by the illumination of the
indicator DOWN lights.
The aircraft touched down smoothly but with the
la nding gear still retracted , and slid over 200 metres
before coming to rest. Subsequent investigation
revealed that the undercarriage system, including the
indicator lights and the warning horn, was fully
serviceable. Examination of the landing gear selector
switch showed that it was in the OFF (centre) position.
It transpired during later discussion that, when
selecting the landing gear down, the pilot had been
holding the microphone in his right hand. Apparently
when he operated the landing gear switch, also with his
right hand, the microphone contacted the elevator trim
wheel. This felt to the pilot as though the undercarriage
selector had 'clicked' into the DOWN position. By then
not checking the indicator lights, the pilot had set
himself up for a wheels-up landing. He did n ot hear the
undercarriage warning horn when the throttles were
retarded because of the high noise level of the HF radio
from the co ckpit speaker.
The main lesson to be drawn from this accident is
that of cockpit checks and checklist discipline.
Additionally , some worthwhile points can be raised
concerning the allocation of work priorities, distractions
in the cockpit , and the correct op eration of this
,particular la nding gear selector.
8 I Aviation Safety Digest 779
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T he effectiveness of a warning indicator of any type is
significantly reduced if distracting influences are
allowed to remain in the cockpit. Audio warnings can
become inaudible if the background noise level is too
high, while visual warnings may become invisible if the
light level is too high or other indicators are excessively
brigh t. Every effort must be made to ensure that
distracting influences are removed from the cockpit,
especially during critical phases of flight.
D 0 II ~--
Checklist discipline
Many words have been written about the use of
checklists. Regardless of the type of checklist used roller blind, printed pages, mnemonics committed to
memory, etc - the pilot must ensure that it is
completed and the correct results obtained at the
appropriate time; that is, that the action demanded is
satisfied by the correct reaction.
•
If an aircraft is fitted wit h a mechanical checklist then
it should be used, as it provides a positive record of
how many checks have been completed should the
sequence be interrupted. When the mnemonic system is
used, it is safest to return to the beginni ng of th e list if
an interruption occurs, rather than trusting to memory.
While o ur memories usually do the right thing b y us, it
only needs one seemingly minor oversigh t to precipitate
an accident.
It is sou nd airmanship in using checklists to have a
'backup' system for the most crucial items. For that
reason a ' finals' check covering those items is almost
invariably used by experienced pilots operating without
the benefit of a question and response system; that is,
operating by themselves, as is the case in the majority
of GA flights.
There are three vital items which should be checked
on final approach before a GA aircraft reaches the point
from which it is committed to land:
• the landing gear must be down and locked;
• flaps must be set correctly fo r the type of approach;
and
• the engine controls must be set to permit the
application of maximum power if it becomes
necessar y.
Although the gear check does not apply to fixed
undercarriage a ircraft, it is good practice to include it
in all ' finals' checks - it is better to develop the habit
rather than run the risk of forgetting the check when
you fly a retractable gear m achine. Significantly, the
pilot of the a ircraft in the accident described at the start
of this article did not complete a ' finals' check.
D epending on circumsta nces, it is also a sound
procedure to confirm to yo urself during the ' fina ls'
ch ecks that a clearance to la nd has been given.
Work priorities
Again turning to the accident cited at the start of the
article, par t of the problem there stemmed from the fact
that, while attempting to lower the undercarriage, the
pilot allowed his attention to be diverted.
Correct operation of the landing gear selector
The electronic checklist system shown on page 8 was
developed by Missionary Aviation Fellowship. For each
checklist sequence the lights will illuminate in a set pattern
once all the checks from that sequence have been
completed.
Pictured above is a simple but effective and flexible 'pho to
album' checklist, also used by MAF.
There are basically three levels of activity associated
with the safe operation of an aircraft:
• the com pletion of those items on the checklist which
will p revent damage occurring to the aircraft, e.g.
selection of the landing gear down before landing;
• the com pletion of those items which could possibly
jeopardize the safety of the aircraft, e.g. the selection
of full flap b efore a short field landing; and
• the completion of those items which cannot have a ny
effect o n safe o perations, e.g. cancelling
SARWATC H.
T he order of priority to be allocated to the above
three levels of activity is quite obvious. There is no
room for th e division of attention while completing
checks in the first two categories. The pilot's attention
must be undivided while he ensures that the action
called for is completed , and the necessary reaction
obtained. In the case of the third level some latitude
clearly is per m issible, as long as checklist discipline is
such that all items are ultimately completed in good
time.
While the importance of checklist discipline is the main
lesson arising from this accident, some useful
observations can be made concerning the operation of
the gear selector .
The lan ding gear selector fitted to this aircraft is a
three-posi tion switch, identified by a wheel-shaped
knob. The possible switch positions are UP, OFF
(centre) and D OWN . T his type of switch is common to
those Cessna aircraft fitted with an electrically-powered
landing gear system; the range of aircraft includes the
followi ng models:
310 and 3 20 series
340, 340A
401, 401A, 401B
402, 402A, 402 B
411 and 414 series
421, 421A and 421B
T o operate the landing gear t he switch knob is pulled
out and moved to the desired position. The three
posit ions of the switch are physically set by a flat 'gate'
between the U P and DOWN positions. In the OFF
position the switch knob is resting on the gate.
O bviously the UP and DOWN selections should
result in a corresponding position of the landing gea r.
The OFF position is only used during manual ext ension
of the landing gear. I ts purpose is electrically to isolate
the landing gear motor during manual extension,
thereby providing an additional safety measure should
the actuator motor fail to mechanically disengage when
the m anual handcrank is enga ged .
Care must be taken when using this type of switch to
ensure that the desired selection is made. It is not
difficult inadvertently to move the knob to the OFF
position and leave it there instead of in either the UP or
DOWN position.
Summary
This accident was a consequence of an undisciplined
approach by the pilot , who allowed himself to be
diverted from his primary task, namely, that of landing
the aircraft. T he accident pa rticularly highlighted the
importance of the 'action and reaction ' rela tion ship
during cockpit checks. For every checklist action there
is an appropriate response; a response that m ay vary
from a gauge changing its indication or a light
illuminating, to the confirmation of performance da ta .
Whatever form that response may take, the thorough
and d isciplined observance of the ' a ction a n d reaction'
procedure in the cockpit is crucial to safe operations •
Aviation Safety Digest 119 I 9
�Flying with
unserviceabi Iities
Jntlight vibration
to, a nd detected by, the pilots on their prefligh t
inspections' .
NOW I WILL
...
SHOW YO/I A
BA~REL ROLL /
I
-=--===-------= · ~ ;_-~-
A very experien ced pilot intended carrying out a period
of aerob atics in his local training area. He was taking a
p assenge r who was a student pilot.
After completing a daily inspection th e pilot strapped
into his aircraft a nd u neventfully carried ou t the startup , tax i, run-up a nd takeoff.
During the climb th e student pilot, who was
occupying the rear sea t, inquired how the engine was
performing, as h e had heard that recently it had run
roughly on occasion s. The en gine in fact operated
satisfactorily during the climb but soon after the pilot
had levelled a t 1500 feet and set cruise power, short
periods of apparent rough running were noticed. A
climb to 2000 feel was then carried out and excessive
vibration which seemed to be associated with rough
en gine running was again evident. Once level flight was
resumed increased periods of more severe vibration
occurred.
In an attempt to isolate the source of the problem the
pilot established hims~lf in the t raining area and
experimented w ith engine power settings, the fuel
mixture and carburettor heat. By this stage the
apparent engine vibration s ha d become even more
severe, although co nfined to p eriods of short duration .
Altering the setting of an y engine control would
temporarily alleviate the vibration.
Becau se he did no t want to disappoint his passenger
the pilot decided that he would sti.ll go to the aerobat ic
area - notwithstanding the vibratio ns, which sho uld
h ave been cause for serious co ncern if not alarm .
Again, short periods of severe 'en gine roughness' were
experienced, and again the pilot tr ied to locate the
source.
Finally the pilot decided h e could n o lon ger accep t
10 I Aviation Safety Digest 119
the a ircraft's abn ormal behaviou r so he turned back
towards the airfield . A descent to 1500 feet was
com men ced and that alti tu de was maintained until the
circuit was r~j oined on the dead side. There was no
vibration du ring this phase of the flight.
Following the rejoin , a normal circuit was flown. On
final approach , with an a irspeed of 70- 75 knots, the
pilot fo und that the elevator trim was ineffective when
h e tried to apply nose- up trim , bu t worked normally for
nose-down. H e moved the trim control to the full noseup posit ion a nd continued with the landing. The stick
force required to flare and complete a three-point
landing was n oticeably heavy bu t presented no
difficulty .
Post-flight inspection revealed that the elevator trim
tab was damaged and that the nose-up elevator trim tab
cable was broken a t th e turnbuckle . Further
investigation led to the detection of a broken rib in the
elevator and cracks in the leading edge torque tube near
the inner end.
It was this fault which , in a ddition to depriving the
pilot of nose-up trim during landing, had caused the
apparent 'rough runn ing' and vibration: there was
nothing wrong wi th the en gine.
The specialist en gineering report pr epared by the
Bureau of Air Safety Investigation concluded tha t
because of the fracture of t he t rim tab hinge at the
inboard left bolt location, tab buzz h ad develop ed. In
addition to the ensuing structural d amage which the
fracture caused, th e tab buzz was also responsible for
the vibration which had been m istaken fo r rough
en gine running. The defect was considered to have
been present fo r som e period, and the specialist repor t
commented that ' th is damage should have been visible
Comment
The reason why the trim tab hinge was fractured was
the subject of considerable investigation. What is of
interest here, however, are the operational aspects of
the occurrence relating to maintenance, supervision,
and the pilo t 's actions .
First, concerning maintenance, on several occasions
prior to this sortie, inflight vibration had been
experienced and reported. Because the pilot reports
indicated that the e ngine was the source of the
vi bration, no conside ration was given to the possibility
of airframe vibratio n , so maintenance inspections were
limited to the engine. It does not seem unreasonable to
suggest that, once the initial inspection h ad failed to
identify any problems with the engine, further
investigation into other components should have been
instigated. This was not the case.
Second , th ese reports of recurring vibrations should
have attracted - but apparently did not - the
immediate and direct involvement of the operating
organisation's m a intenance and flying superviso~s.
T he lot of a su pervisor is, admittedly, often difficult.
Sometimes his dir ect involvemen t can be
counter productive as it can inhibit the initiative and
activities of o thers . Nevertheless, an unexplained
infl igh t vibrat ion is a serious matter, with serious safety
implications. Super visors should arrange their
organisational procedures to ensure that recurrent
abn orm alities such as this are brought to their
attention; an d th ey also need to become personally
in volved, as their experience could make the difference
in diagnosing the problem .
Finally, it is easy to appreciate the pilot's wish not to
disappoint his passenger. The pilot also was highly
experienced and this doubtless influenced his initial
decision to press on and to attempt to isolate the cause
of the vibration . Nevertheless, the fact remains that he
was flying in a single -engine aircraft which was subj ect
to frequen t periods of apparently severe engine
vib ration . When you have a choice, there is only one
place from which to analyse engine problems - on the
ground ! A prompt return to the airfield via a
pr ecaut ionary forced landing pattern - not via an
immediate descent and a normal circuit - would have
been the most pruden t course of action as soon as an
engin e malfunccion was suspected. The declaration of
an emergency m ight also have been considered.
Summary
Ab normal inflight vibration is a serious matter, and any
time it occurs a pilot has grounds for considerable
concern. It is a situation which demands prompt
infli.ght acti_on based on safety-first criteria, whil~ it also
requires the serio us attention of supervisors, engmeers
and operators to resolve the problem •
Approaching a general aviation aerodrome, the pilot
of a PA 32-260 advised the Tower that he was very
low on fuel and expressed concern that he might not
reach the airport. The Senior Operations Controller
immediately declared an Alert Phase emergency,
which was cancelled when the aircraft eventually
landed safely.
It later transpired that the pilot had experienced
difficulties with the aircraft's mixture control on the
previous flight. The control apparently felt 'odd'
inflight, while after landing he had been unable to
shutdown the engine using the mixture lever, and
had instead turned off the magnetos to stop the
engine. Fuel usage during the flight had also been
high, but the pilot did not associate this with the
problems he was experiencing with the mixture
control.
During flight planning for the next trip the pilot
had indicated to the briefing officer that he was not
entirely happy with the mixture control;
nevertheless, he proceeded with the flight.
Once the Cherokee Six was established in the
cruise the p ilot noticed that the fuel gauges were
moving towards empty at a faster than normal rate.
Although suitable d iversion aerodromes were
available, he elected to 'press on' . Just before the
destination was reached the gauges indicated that the
fuel tanks were empty, and this resulted in the pilot
advising ATC of his predicament.
A technical investigation revealed that the mixture
control clamp nut had cracked, allowing the outer
mixture cable to slide freely without affecting the
mixture control valve. This rendered the mixtu re
control ineffective, and was the reason for the pilot's
inability to shutdown the engine with the mixture
lever and the excessive fuel consumption.
Discussion
It would be unrealistic to state categorically that
pilots should never fly a ircraft which have an
unserviceability of some kind. Obviously, in certain
conditions, and depending on the nature of the
defect and the type of operation planned, it can be
perfectly safe to do so, e.g. unserviceable navigation
aids for a VFR flight. I t should be noted, however,
that such assessments are often more complex than
may seem apparent on the surface; therefore, the
advice of a flying supervisor and a LAME should be
sought.
I t can be stated unequivocally that there are cer tain
types of defects wh ich should never be accepted, and
those affecting engines and airframes, for example,
unquestionably fall into that category. In this
instance the pilot not only placed himself and his
aircraft at risk, but also came perilously close to
involvement in the potentially tragic consequences of
an engine fail ure over a densely populated area •
Aviation Safety Digest 119 I 11
�Aircraft accident information
reports
Spontaneous combustion
THIRD QUARTER 1983
Prepared by the Bureau of Air Safety Investigation
Some years ago as passenger baggage was being load ed
into a Regular Public Transport jct, one of the ground
staff not iced that a bag was smouldering. The bag was
retri eved a nd the cause fo und to be a book o f matches
which had ig nited s pontaneously. H ad ignition occurred
only minutes la ter, after the bag had been loaded into
the baggage hold , and the fire spread a fter takcoff, the
probable conseque nces arc only too obv ious. The
follow ing art icle, submitted b y a reader , recou nts his
experience wi th t he dangerous phenomenon of
spontaneous combu stion.
*
*
H av ing been a licensed pilot fo r nearl y 25 years I
would like to think th al I have learn ed to value
objective a ir safety investigation , criticism from my
mentors and self-cri ticism, includin g the material
published as ' reade r contributions' in the Aviation Safety
Digest. P e rhaps my con tribu tion m ight b enefit
someone's learning curve.
I am a pipe smoker so I a lways need a pl entiful
su pply o f matches to keep m y much -loved furnace
alight. On an overnight stopover som e months ago I
took the usual book of matches from m y hotel room.
L ater tha t evening, having not used the matches for an
hour o r so, I returned to the hotel and stepped into the
lift. When I put my hand into the jacket pocket wher e
the matches were I immediately became aware of two
vi tal problems, namely, that my hand became very hot
very q uickly, and also that something was burning . . .
I was on fire, left -hand side! Not wishing to emu late a
*
dissident Buddhist mon k, I baled out of m y jacket and
smothe red the fi re . The un fortunate passengers in the
lift showed m ixed reactions of humour at m y immediate
reactions (Phase 1 - Emergency P rocedures) and then
horror at m y follow-up verba l comm en ts (Phase 2).
S u bseq uen t investigation of the in cident revealed that
the pllo t ceased forthw ith the p r actice of collecting
books of matches to sustain his addiction . For the first
time in years I cleaned out m y overnight bag,
dispatching a pile of the wretched m atches to the
wastebin , and thinking how fo r tunate it was that the
problem had never occurred in flight with, perhaps, the
offending baggage being located in an inaccessible
baggage compartment.
While I never forgot the experience I did not speak
mu ch about it until I recently heard that a simila r
in cident occurred d urin g the loading of baggage into an
RPT jet aircraft.
I wonder if a serious a ir craft acciden t will ever be
caused by and traced to a book o f matches wh ich the
owner wo uld have considered innocuous.
*
*
The following informat ion has been extracted from accident data files maintained by the Bureau of
Air Safety Investigation. The intent of pub li shing these reports is to make available info rmation on
Australian aircraft accidents from which the reader can gain an awareness of the circumstances and
cond itions which led to the occurrence.
At the time of publ ication many of the acc idents are sti ll under invest igation and the in formation
contained in those reports must be cons idered as preliminary in nature and possibly subject to
amendment when the investigation is finalised.
Readers shou ld note that t he information is provided to promote aviation safety - in no case is it
intended to imply blame or liabil ity.
Note 1: All dates and times are local
Note 2: Injury classif icat ion abbreviations
C =Crew
P = Passengers
0 = Othe rs
N =Nil
F =Fatal
S =Serious
M =M inor
e.g. C1S, P2M means 1 crew member received serious injury and 2 passeng ers received minor
inj uries.
*
PRELIMINARY REPORTS (The following acciden ts are still under investigation)
R eaders shou ld note that, while passenge rs and crew
are permitted to carry matches on their persons, they
arc not allowed to carry them in luggage unless the
matches have been packed and declared in acco rdance
with Dangerous Cargo Regu lations . While book
matches are the m ost dangerous, these regulations
apply to all matches, including those in boxes and
labelled as 'safety matches ' •
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
02 Jui
Cessna U206 F VH-TIR
Non-commercial - pleasure
C1N , P3N
1240
Forsythe Is., Old.
Morn ington Is., Old./Forsythe Is., Old.
8311041
The pilot reported that while cond ucting a low pass a gust of wind affected the aircraft. He applied power but the engine did not
res pond and the aircraft landed heavi ly on a salt pan. Di rect ional control could not be maintained during the subsequent landing
roll and the nose gear collapsed.
03 Jui
Rutan Vari EZE VH-EZM
Non-commercial-pleasure
C1 F, P1 F
1410
Lake Cataract, NSW
Albion Park, NSWIBankstown, NSW
8321053
Fol lowing receipt of advice t hat the aircraft had fai led to ret urn from a NOSAR, no details flight , searchers found the wreckage
washed up on the edge of a lake. A power line 65 ft above the lake su rface and about 1.5 km from the wreckag e had been
debraided ove r a two-metre length, and init ia l investi gat ion suggests that the aircraft had co llided with this line.
03 J ui
Pi per 28 R180 VH-CHC
Non-commercial-pleasure
C1 N, P3N
1300
Port Macquarie
Port Macquarie/Port Macquarie
8321 054
The pilot was taking part in a spot-landing competit ion. The a ircraft landed heavily but no damage was detected. On subsequent
fligh ts, the gear in-transit warning ligh t remained illuminated when the gear was selected up. A further inspection carried out by a
LAME revealed damage to the left wing and gear housing.
•
04 Jui
Beech V35 VH -CFK
Non-commercial-pleasure
C1 N, P2N
1410
Maroochydore, Old.
Maroochydore, Old./Maroochydore, Old.
8311042
Du ring the landing roll the pilot operated the gear selector in mistake for t he flap lever. Although he immed iately realised his error
and re-selected gear down, the gear up cycle had been initiated and the gear continued to collapse .
05 Jui
Cessna 172 M VH-SYO
Non-commercial- bus iness
C1N , P2N
0700
Emmel Downs, Old.
Isis Downs, Old./Emmet Downs, Old.
8311046
Towards the end of the landing ro ll the pilot posit ioned the ai rcraft to the left s ide of the strip. The left win g struck and rode over a
bush and the left main wheel passed over a windrow. As the left wing lifted, the right wing struck the ground.
During loading of a 8 727, portering staff discovered that a briefcase in the forward locker of the aircraft was smouldering. A
book of matches was subsequently found to have ignited spontaneously.
12 I Aviation Safety Digest 119
06 Jui
Cessna 402 VH-ENO
Charter- passenger
C1N, P8N
11 13
Arc herfield, Old.
Archerfie ld, Old./Jimbour, Old.
8311043
Shortly after liftoff the pilot bel ieved that the left eng ine had fa iled. He was unab le to maint ain adequate a irspeed and e lected to
abandon the takeoff. Directional control was lost and the a ircraft ran off the side of t he strip Into an area of excavation.
Aviation Safety Digest 119 I i
�PRELIMINARY REPORTS (The follow ing acc idents are still unde r investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
13 Jui
Piper PA32-R301 VH-AOP
Ferry
C1N
1857
Batchelor, NT
Batchelor, NT/Darwin, NT
8341021
The engine upper cowl was being replaced following a periodic inspection. The LAME was fasten in g the left side and was being
assisted by the pilot who was working on the right side. Prior to completing the installat ion, the LAME left to answer the phone
and while he was away the pilot completed fastening the right side of the cowl, carried out a hurried pre-fl ight inspection, and
took off 2 minutes before last light. Shortly after takeoff, the cowl detached and struck the tail plane.
PRELIMINARY REPORTS (Th e following accidents are st il l under investigation)
Date
Time
Aircraft type & registration
Locati on
Kind of flying
Departure point/Destination
Injuries
Record number
02 Aug
1515
Non-commercial- aerial mustering
C1M
Cessna A 150 L VH-IER
Mardathuna, WA/Mardathuna, WA
8351 021
Mardat huna, WA
The pilot had been muster ing for most o f t he day. Because the wind strength was increasing, he elected to term inate operations
for the day after complet ing the task at hand. Toward s t he com pletion of a turn at about 200 ft ag l the aircraft pit ched sharply
nose down and commenced to descend rapidly. The pilot too k recovery act ion but was unable t o prevent t he ai rc raft coll iding
wit h the ground. The aircraft then overturned and slid 15 m before stopping.
17 Jui
Rockwel l 685 VH-WJC
Non-commercial-pleasure
C1 F, P1 F
1505
Bass Strait, Vic.
Hobart, Tas./Moorabbin, Vic.
8331017
While cruising at FL 120 the pilot reported low fuel quantity indications. Two minutes lat er the pilot transmitted a Mayday call,
advising that he was leaving FL 120 and that he would be making a contro lled ditching. Radio contact was lost 7 mins after
Mayday call. An F27 aircraft was diverted to the area and reported sighting a survivor in the water. However, contact was lost
shortly before the arrival of a rescue helicopter.
04 Aug
De Hav 114 2D/A1 VH-CLY Sched uled passenger service- commute
C2N, P1 M, P4N
1200
Launceston, Tas.
Wynyard, Tas./Launceston, Tas.
8331020
The ai rcraft was being flown by the f irst officer. On late final approach t he ai rcraft was not al igned with the ru nway and the
captain appl ied full power as he called fo r a go-arou nd . The captain then took control but t he left wing dropped and struck a
fe nce. The ot her fences we re struck as t he aircraf.t yawed throu gh 270 deg rees before com ing to rest on its belly 125 m past the
Ii rst fence.
17 Jui
Bell 206-B VH·KMX
Non-commercial-pleasure
C1 F, P1 M
1240
Lake Burragorang
Bankstown, NSW/Bankstown, NSW
8321055
The helicopter was being flown along a watercourse at a height of about 10 ft and an airspeed of about 85 kt. As the pi lot rotated
the aircraft to commence a climb, the rear of the landing skids struck the water. The helicopter pitched forward, overturned and
sank.
05 Aug
1405
C1N, P5N
Charter-passenger
Beech 58 VH-EZE
18 Jui
8331018
Essendon, Vic./Swan Hill, Vic.
Swan Hill, Vic.
0930
During the landing run, at about 60 kt, the pilot inadvertently selected the undercarriage up instead of the flaps. All three
undercarriage legs retracted and the aircraft slewed right, through 180 degrees, before coming to rest off th e s!de of the runway.
C1N
Non-commercial/pleasure
Cessna 150 E VH-KMJ
20 Jui
8331019
Devonport, Tas./King Island, Tas.
Three Hummock Is.
1049
The pilot elected to carry out a precautionary landing on a 900 m strip because of a rough-running engine. As he flared the aircraft
for touchdown, a wind gust was encountered and the aircraft ballooned. The subsequent touchdown was on the nosewheel and
the aircraft bounced twice. On the third touchdown, the nose gear collapsed and the aircraft sl id to a halt.
C1F
Non-commercial-pleasure
Cessna 172-P VH-WRX
20 Jui
8351020
Wiluna, WA/Lake Way Station, WA
Wiluna, WA 2S
1640
Immediately after takeoff the aircraft was seen to enter a steep climbing t urn to the left. After t urning through about 135 degrees,
and at an estimated height of 100 to 150 ft agl, the aircraft suddenly pitched nose down and lost heig ht. The aircraft coll ided with
a tree prior to impacting the ground in a nose-low, left wing down attitude.
24 Jui
Cessna 210 M VH-MDG
Non-commercial-pleasure
C1N, P1S, P4N
1940
Sydney, NSW
Sydney, NSW/Aero Pelican, NSW
8321056
When two passengers had not arrived at the aircraft by a pre-arranged time, the pi lot commenced to taxi for departure. After the
aircraft had travel led a short distance, one of the missing passengers approached the right hand door. The pilot stopped the
ai rcraft, and shortly afterwards the other passenger was seen moving along the left side of t he aircraft towards the nose. The pi lot
shouted a warning and moved to shut down the engine, but the passenger was struck by the pro peller.
C1N
Commercial-aerial agriculture/bait ing
Airparts 24 A4 VH-BBM
26 Jui
8321057
Tenterfield (Agstrip)/Tenterfield (Agstrip)
Tenterfield 2S
1505
On takeoff the left main wheel and inner o leo leg fell from the aircraft. Th e pilot noti f ied emergency servi ces and carried out a
landing at a lower than normal touchdown speed . The trai ling edge of the left wing contacted the strip during the landing roll.
C1N
Non-commercial-pleasure
Cessna 182 H VH-KMM
27 Jui
8321058
Cobar, NSW/Mudgee, NSW
Nevertire 15SE
1610
During cruise the engine began to run roughly. Full rich mixture and carburettor heat were applied and the flight cont inued to the
next landin g point. About 15 minutes after departure from th at point the engine again ran roughly, t he pil ot app lied f ull rich
mixture and carburettor heat and continued. An hour later the engine lost all power and a land ing was carried out in a paddock.
During the landing roll, the aircraft struck five sheep . Both fuel tanks were found to be empty.
C2N
Ferry
Beech 76 VH-HFS
27 Jui
8311045
Archerfield, Old./Toowoomba, Old.
Toowoomba, Old.
2005
The ai rcraft was being positioned at night for a flight the next day. On arrival at the destination an instrument app roach was
carried out with the aircraft becoming visual at the minima. After joining the circuit the pilot had to manoeuvre the aircraft around
cloud on the downwind leg. When turning onto the base leg the pilot lost sight of the runway and ini t iat ed a missed approach. The
aircraft struck power lines and slid to a halt on a roadway.
C1N, P1N
Non-commercial - corporate/executive
Bell 206 B VH-CEC
29 Jui
8321059
Wickham Heliport/Maitland, NSW
Wickham Heliport
1550
The helicopter had been parked adjacent to a raised refuelling platform, 60 mm hi gh. As the pilot was bring ing the helicopt er to a
hover, the right skid contacted the platform . The pi lot attempted to correct wit h cyclic but t he heli copter ro lled to t he right
coming to rest on its right side on the platform.
C1S
Non-commercial - pl easure
Evans VP2 VH-ITA
01 Aug
8321 060
Wedderburn , NSW/Wedderburn , NSW
Wedderburn, NSW 1 NW
1715
Following a series of taxi trial s the pilot elected to carry out a circuit. Shortly after becom ing ai rborne t he aircraft stru ck th e
ground in an almost vertical nose-down attitude.
ii I Aviation Safety Digest 119
Cessna A188B-A1 VH-KZC
Mitta Mitta, Vic. 5N
Com mercial-assoc. agriculture/baiting
Mitta Mitta, Vic./M itta Mitta, Vic.
C1 M
8331 021
The pi lot in itiated a 180 deg posit io ning t urn to commence a superphosphate spread ing run. Abou t halfway th rough the turn the
pilot felt the aircraft sink slightly . He levelled the wings and applied slight back press ure o n the cont rol col umn, but did not
increase power. The aircraft stal led, m ushed into tree tops and impacted the gro und in a near-vertical attitude before com ing to
rest inverted. The pilot evac uated j ust before t he aircraft caug ht fi re.
Non-commercial - pract ic e
C1N, P4N
10 Aug
Cessna A185 F VH-IVG
8311 050
Cai rns, Old./Cairns, Old.
1116
Cairns, Old .
The pi lot had considerable aeronaut ical experience but was not fam iliar with the Cessna 185 type. He intended to use the aircraft
to fl y to an island tou rist resort , and was carrying out a series of pract ic e c ircuits prior to departu re. Wind condit ions were gust y
and on t he final land ing roll d irectio nal control was lost at a s peed of about 30 kt. The r ight wing and the propeller struck the
ground and the aircraft t hen fell back heavily onto the tailwheel.
11 Aug
Cessna 150 M V H-RZA
No n-commercial-business
C1S
1130
Amburla, NT 7S
Amburla St at ion, NT/Valley Bore, NT
8341026
The airc raft was flown back and fort h above a quarantine paddoc k in order to ensure that no catt le remained. The search pattern
was flown at about 200 ft ag l. Ground marks and broken trees ind icate th at the aircraft st ruck t he grou nd in a spin to the right. The
pilot does not recall the sequence of event s immediately prior to the acc ident.
12 Aug
1550
Cessna A188 A1 VH-KOE
Commercial- aerial agriculture/bai t ing
C1 S
Scone, NSW 24W
Scone, NSW/Scone, NSW
8321061
On the sixth run of a weed-spraying operat ion, the aircraft passed un der a power line which the pi lot had not seen. The power line
stru ck the deflector cable which failed adj acent to the f in upper attac h point. The top sect io n of the fin and rudder mass balance
were severed and two rudder hin ges fai led, allowing the rudder to hang loose and fou l the elevators. The aircraft st ruck rising
gro und 800 m after t he wire st rike.
16 Aug
1100
Amer Air 5 A VH-1 FI
Maryborough 50S
Non-commercial - pleasure
Archerfield, Old ./Call ide, Old .
C1 N, P1 N
8311 051
T_he pi lot decided to land t he ai rcraft on a road because of deteriorat ing weather. During the landing roll the left win g st ruck a road
sign.
23 Aug
1510
Cessna 210 L VH-SRJ
Gu nnedah, NSW
26 Aug
1510
Beech 58 VH -A DB
Markdale, NSW
Non-com mercial- pleasure
C1 N, P3N
Albury, NSW/Gu nnedah, NSW
8321 063
As t he aircraft was tax ied c lear of the runway the pilot inadvertent ly selected the lan din g gear up. The nose gear retracted an d the
propelle r and forward f uselage contacted t he ground.
Non-commercial-pl eas ure
C1N, P4N
Cooma, NSW/Markdale, NSW
8321064
The pi lot was making an approach, in light rain, to a 747 m-long grass strip . The aircraft touched down 85 m beyond th e approach
end and bounced. After the seco nd touchdown the pi lot ret racted the f laps and commenced braking . The aircraft sk idded on the
wet grass, overran the strip and c ollided with a w ire fence.
27 Aug
Bellanca 8 KCAB VH -VOO
Instruct ional-so lo - supervised
C1 N
1600
Haxton Park, NSW
Hoxton Park, NSW/Hoxton Park, NSW
8321065
The pilot had recently co mpl eted his tai lwheel ai rcraft endorsement and was carrying out solo pract ice. On the first c ircu it the
aircraft to uched down before the runway t hreshold and ground looped to the rig ht. The left main gear leg collapsed and the
airc raft tipped onto the left win g and nose before com ing to rest.
28 Aug
2200
Beech 200 VH-KTE
Adavale, Old . 5S
Charter- passenger
Windorah, Old./Toowoomba, Old.
C1 F, P1 1F
8311053
The aircraft was on the return leg of a flight begun earlier in t he evening. The pi lot made a normal departure report and
subsequent ly ackn ow led ged an ATC clearance to cru ise at f lig ht level 270. No f urther comm unicat ions were received and t he
wreckage of t he ai rc raft was later discovered about 210 km from the departure aerod rome. It was apparent t hat t he aircraft had
broken up in flight at a relat ively low altitude as a resu lt of aerodynam ic overload ing of t he structure.
A viation Safety Digest 119 I iii
�PRELIMINARY REPORTS (The fol lowing accidents are stil l under investigation)
Kind of flying
Departure point/Destination
Injuries
Record number
PRELIMINARY REPORTS (The fol lowing accidents are stil l under investigation)
Date
Time
Aircraft type & reg istration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
Date
Time
Aircraft type & registration
Location
28 Aug
11 30
Cessna 182 C VH -BXW
Branxton, NSW 5N
Parachute j ump-air show
C1N, P4N
Enderslie, NSW/Enderslie, NSW
8321066
The aircraft was carrying parachutists who were engaged in a competition skydiving event. As the aircraft climbed through 1500
ft, the engine emitted a loud bang, then stopped. The parach utists abandoned the aircraft and the pilot carried out a forced
landing into a nearby paddock. After a ground roll of about 50 m the engine fell from the aircraft. Inspection revealed that one
propeller blade had detached in flight and the eng ine mounts had broken.
11 Sep
Cessna 172 M VH-IQG
Non-commercial-pleasure
C1N, P1N
1100
Bairn sdale, Vic.
Bairnsdale, Vlc./Lakes Entrance, Vic.
8331027
On departure the pilot observed a cold front lying across the intended track and approac hing rapidly. He doubted that VFR flight
could be maintained and turned back to land on runway 32. The wind was from t he northwest gusting to 30 kt. On the landing rol l
as the aircraft slowed to fast taxi speed, the wind swung strongly to the southwest. The pilot reported that he was unable to retain
control of the aircraft, wh ich overturned and came to rest inverted.
28 Aug
101 5
Pi per 28 161 VH-BZA
Li lydale, Vic.
18 Sep
1610
Piel 100 VH-FWB
Gunnedah, NSW
01 Sep
1400
Hughes 269 C VH-THV
Mary Kathl een, Old.
18 Sep
1500
Piper 32 R300 VH-RHT
Kieta, PNG 64N
Non-commercial-pleasure
C1N, P1 N
Lilydale, Vic./Li lydale, Vic.
8331022
After complet ing a touch and go land ing on the longer of t he two grass strips avai lab le, the pilot decided to make a flapless full
stop landing on the shorter strip. The approach was high, t he aircraft floated and touched down 319 metres before the end of the
strip. Despi t e heavy braking, the aircraft slid over the end of the strip and st ruck an earth bank 60 metres beyond.
Non-commercial - pleasure
C1F, P1F
Gunnedah, NSW/Gunnedah, NSW
8321074
The purpose of the flight was to show t he passenger the characterist ics of a tailwheel aircraft. After a normal approach and
touchdown, the ai rcraft was observed to go-around and fly level at a low height above the runway. The aircraft was then seen t o
c limb steeply, stall, and to impact the ground in a steep nose-down attitude whilst rotating to the right.
C1N, P1N
831 1054
The pilot was m usterin g in a valley and was hovering at a low height behind a small mob of cattle. He reported that the aircraft
suddenly encountered sink, which continued despite his application of f ull power. A turn towards more suitable terrain was
att empted but the helicopter fai led to respond. Touchdown occurred on sloping ground and the aircraft rolled on to its s ide.
Non-commercial-pleasure
C1N, P3N
Kieta, PNG 64N/unknown
8391002
The pilot was cond ucting a pleasure flight from Australia to the Solomon Islands via various aerodromes in Papua New Guinea.
He reported that short ly after takeoff the engine lost power and he was forced to ditch the aircraft , which subsequently sank in
100 m of water. Investigation of this acc ident is the responsibil ity of the PNG authorities.
Victa 100 VH-BWG
Non-commerc ial-pleasu re
C1N, P1 N
01 Sep
1530
Peterborough 9NW
Peterboroug h 9NW/Peterboro ugh 9NW
8331023
The owner-pilot had limited experience on the type and intended to carry out practice circuits and landings. The first takeoff was
normal and the pilot then flew t he aircraft c lose to the ground in order to accelerate to a higher speed prior to initiating a climb.
Sink was encou ntered and the aircraft struck rising terrain beyond the end of the strip. The pilot closed the throttle and applied
braking but was unable to prevent the aircraft colliding with a fence.
18 Sep
De Hav DH 82-A VH-KBX
Non-commercial-pleasure
C1 N
Unknown
Narromi ne, NSW
Narromine, NSW/Narromine, NSW
8321073
The pilot was pract ising a touch and go landing on a grass field. As t he pi lot re-applied power and moved the control colum n
forward to raise the aircraft tai l, the propeller struck the ground. The tail of the aircraft continued to rise, and at a low forward
speed the aircraft nosed over and came to rest inverted.
Commercial-aerial mustering
Mary Kat hleen, Old./Mary Kathleen, Old.
01 Sep
Hughes 269-C VH-TIH
Commercial-aerial mustering
C1N, P1 N
1600
Powe ll Creek, NT 3S
Four Mile Bo re, NT/Four Mile Bore, NT
8341027
Cattl e mu stering operations had co mmenced early in t he day wi th breaks for refuelling and a meal. On departure after refuelling
the aircraft ent ered a right t urn, and at about 40 feet above t he ground the engine lost power. There was neither adequate speed
nor height avail able for a controlled landing but t he pilot was able to level the aircraft before it crashed through small saplings
and tree st umps.
Non-commercial-pleasure
C1N, P1M, P2N
05 Sep
Cessna 182 P VH-DKL
Kyneton, Vic.
Broken Hill, NSW/Essendon, Vic.
8331 025
1400
Being unable to conti nue to his dest ination because of deteriorating weather, the pilot decided to land at an airfield enroute. The
airc raft to uched down about 140 m beyond the strip t hresho ld but then bounced. After the second touchdown the pilot applied
braking, which had little effect. He t hen attempted to steer the aircraft onto an adjacent grass strip, however the aircraft
continued straight ahead, passing over two d itches and a fence before overt urnin g.
05 Sep
Gulfstream 695 A VH-LTJ
Non-commercial-D.O.T. survey
C2N, P5N
1130
Launceston, Tas.
Launceston, Tas./Launceston, Tas.
8331026
After the gear was lowered during the approach, a normal gear-down indication was observed by both crew members. The aircraft
touched down on the main wheels, and as the nose was lowered the pilot heard a loud noise and noticed that the nose attitude
was lower than no rmal. The nose was raised, and when subsequently lowered the nosewheel contacted the runway and all
nosewheel f unctions operated normally.
07 Sep
Cessna A188B A1 VH-EJV
Commercial-aerial agric ult ure/baitin g
C1S
1430
Caroona, NSW 11 NW
Caroona, NSW 8N/Caroona, NSW 8N
8321068
The pilot was engaged in spraying a wheat crop situated in a paddock, which was bounded on the south by a power line and on
the west by a spur line. The aircraft had completed several runs, crossing over the spur line at right angles. As the aircraft
commenced what was to be the second last swath run, the main landing gear struck the spur line and the aircraft pitched nose
down into the ground.
C1S
Cessna A 188B A 1 VH-PGO Commercial - aerial agr icult ure/baiting
09 Sep
Hillst on, NSW/Hi llston , NSW
8321069
1655
Hillstori, NSW 10NW
The operat ion involved the spraying of a series of cult ivated paddocks. The last swath run of the t ask was carried out along one o f
the paddock boundaries. Short ly after the run was beg un, the aircraft st ruck a set of power lines. The tops of the fin and rudder
were torn off and the aircraft stru ck the ground 50 m beyond the wires. The aircraft cartwheeled and came to rest inverted.
21 Sep
1000
Cessna 182-0 VH-KFS
Mt. Newman, WA 259N
Non-commercial- pleasure
Jigalong Station, WA/J igalong Station , WA
C1 N, P3N
8351023
During t he latter part of the landing rol l on an apparent ly dry lake bed, the aircraft entered an area of soft ground. The pilot was
able to keep the aircraft moving until the f irmer surface was regained. He then taxied the aircraft across the soft area again in
order to achi eve an into-wind takeoff. During the takeoff roll the ai rcraft decelerated as it traversed the soft area. The pilot elected
to abandon t he takeoff and ground looped the aircraft to avoid rough terrain.
25 Sep
Piper 32 260 VH-IRT
Non-commercial-pleasure
C1 N, P2N
1307
Ewan Racecourse
Dennington Air Park/Ewan Racecourse
8311061
The pilot was conducting a short f ield approach into a 525 m strip. He reported that thermal activity was encountered and the
aircraft touched down a short distance beyond the target point. As soon as f ul l brakes were applied, the aircraft commenced to
veer to the left, and despite corrective action the pi lot was unable to prevent the aircraft runn ing off the side of the strip.
26 Sep
1648
Cessna 182 0 VH-KDW
Asquit h, NSW
27 Sep
1400
Hughes 269 C VH-GHV
Black Gin Yard 5S
27 Sep
1700
Piper 25 235 VH-PPP
Gwabegar, NSW 9SE
Non-commercial -pleasure
C1N, P3N
Eildon Wei r, Vic./Aero Pelican , NSW
8321075
After experiencing erratic eng ine operat ion, the pilot elected to make a precaut ionary landing on a nearby golf course. The init ial
approach was unsatisfactory and a go-around was made. As the aircraft turned onto a base leg for landing, the engine lost power
completely. The aircraft descended steeply, struck a television antenna and a tree, bounced off a sealed road and col lided with
the boundary fence of the golf course.
Commercial-aerial mustering
C1N
Koolatah , Old./Koolatah, Old.
8311064
The pi lot reported t hat as he brought the aircraft to hover it began to rotate to the right. Corrective action was ineffective and t he
rate of rotati on began to increase. Whi le the pilot was attempting to look for a suitable land ing area, a tail rotor strike was felt and
cont rol was lost. The helicopter finally came to rest on its right-hand side.
Commercial-assoc. agricu lture/baiting
'Merebene' Property/Tamworth , NSW
C1N
8321076
A power line crossed the south-eastern end of the strip, and while carrying out spraying operat ions the pilot had made all takeoffs
into the northwest. At the end of the task, the pilot refuelled the ai rcraft, and because his home base was to the southeast he
elected to take off in that direction. He reported that he had temporari ly forgotten about the power line. Shortly after liftoff the left
wing struck the wire and the aircraft landed heavily in an adjoining paddock.
C1 N
Cessna A188B A1 VH-EVV Commercial-aerial agriculture/baiting
10 Sep
8321071
Binnaway, NSW ?SE
Binnaway, NSW 7SE/Binnaway, NSW ?SE
1200
The aircraft was descending over a line of trees prior to commencing a sp ray run when the left wing collided with the branch of a
t ree. The pilot was able to maintain con trol of the aircraft and land at a nearby strip.
10 Sep
1400
Burkhart ASTIR CS
Tirroan, Old. 2N
VH-WOJ Non-commercial- pleasure
Elliot Field, Old./Elliot Field, Old.
C1N
8311056
During the course of a soaring flight it became necessary to make an out landing. A suitable landing area was not available and the
pilot elected to land in a ploughed field . During the landing run the right wingtip struck rough ground, the glider ground looped to
the right and the landing gear collapsed.
iv I Aviation Safety Digest 179
Aviation Safety Digest 119 I v
�FINAL REPORTS (The investigation of the follow ing acc idents has been completed)
FINAL REPORTS (The invest igation of the following accidents has been completed)
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours on Type Rating
Hours Total
Injuries
Record
number
Date
Time
Pilot licence
Non-commercial-pleasu re
C1N, P4N
02 Jui
Piper 32 R300 VH-UAM
8321052
Bankstown, NSW
Bankstown, NSW/Bankstown, NSW
1056
Unknown
None
107
Private
30
The pilot was conducting a series of circuits when loud static noise developed in the VHF radio. Attempts to recti fy the problem
were unsuccessful and the pilot then turned the radio off and prepared to land. He subsequently reported that he had selected
the gear down, however the aircraft landed with the gear retracted.
Hydraulic and electrical defects were discovered which, in combination, rendered the gear-unsafe warn ing horn and the normal
gear extension system unserviceable. The pilot who had limited experience on the aircraft type had left the gear manual lever in.
the override position which precluded automatic free-fall of the landing gear. The gear override warning light was also found to be
unserviceable.
26 Aug
Ro binson R22
1225
Mareeba, Old.
Commerc ial helicopter
02 Aug
Piper 28 R201 VH-EHK
Non-commercial-pleasure
C1N
1420
Surfers Gardens, Old.
Goondiwindi, Old./Surfers Gardens, Old.
8311047
Commercial
68
16200
1934
None
During the flight the aircraft alternator failed. The pilot switched off all electrics but left the master sw itch on. On arrival at his
destination, the pilot selected t he landing gear down and noticed that the gear position lights remained unlit. The circuit was
continued and the aircraft landed with the gear retracted.
The alternator failed to operate as a result of a broken drive belt. The pi lot d id not check that the gear was down , and the
emergency system was rendered inoperative because of the pi lot's habit of placing the appropriate lever in t he override position.
The pi lot had experienced several electrical failures in the ai rcraft in the preceding months, but on each occasion the gear had
lowered after the normal selector had been used.
37
The pilot commenced the takeoff from a two-foot hover and misjudged the horizontal and vertical distance of the helicopter from
the fal len tree.
02 Sep
1130
Glider
07 Aug
Hiller UH12-E VH-MKZ
1400
Brisbane, Old. 65N
Commercial helicopter
Commercial-ae rial agricu lture/bai t ing
C1 N
Coochin Creek, Old ./Coochi n Creek, Old.
8311049
48
17050
1050
Agricultural Class 1
During the day the wind direction had changed through 90 degrees. To optimise takeoff performance, the pi lot, after the
helicopter was brought to a hover, initiated a turn around the axis of the rotor mast for an into wind takeoff. After commencing the
turn the pilot lost sight of a f uel drum which was alongside the landing area and the tail rotor struck the drum. The helicopter was
landed without further damage.
The pilot was relatively inexperienced on the aircraft type. The directional diffic ulti es experienced by t he pi lot during the takeoff
run were exacerbated by a centre of gravity at or very close to the rear limit. Additional ly, the pilot chose to conduct his operation
from a narrow strip.
vi I Aviation Safety Digest 119
Glasflugel Club Libelle
Cooma, NSW 15WNW
VH-GJM
32
Non-commercial -pleasure
Bunyan, NSW/Bunyan, NSW
670
200
C1 N
8321067
Gl ider Rating
The pi lot was engaged in a wave soaring exercise. After about one and a half hours of flig ht adequate altitude co uld no longer be
maintained and the pilot was comm itted to an out landing. During the f inal stages of the approach the pilot manoeuvred the glider
to avo id a paddock boundary fence. The right wing struck the ground and the glider landed heavily.
When planning the approach, the pilot m iscalcu lated the wind di rection and as a result did not select a landing path into w ind.
02 Sep
1545
Private
Cessna 172 N VH-MCJ
Inman Valley, SA
07 Aug
Cessna 180 D VH-SLT
Sport parachute jump
C1N, P5N
0930
Lower Light, SA
Lower Light, SA/Lower Light, SA
8341023
Private
211
34
Instrument Rati ng Class 4
33
Shortly after the takeoff run was commenced in moderate cross-wind conditions, the airc raft veered to the left. Corrective action
was taken but the pilot could not maintain directional control and elected to abandon t he takeoff. The aircraft ground looped and
the left landing gear strut was torn off.
46
Charter - passenger
C1 N
Mareeba (Rotary Park)/Mareeba (Rodeo Park) 8311052
9650
60
Instrument Rating 1st or
Class 1
Commercial -aerial ag ricu lt ure/baiting
C1 N
01 Sep
Hiller UH12-E VH-MKZ
Mondure, Old./Mondure, Old.
8311 055
141 5
Wondai, Old. 28NW
17020
1020
Agricu ltural Class 1
48
Commercial helicopter
Spraying runs were being flown under a two-cable power line. On the final turn of the th ird load, the pilot's attention was
distracted and the main rotors struck one of t he cables. Considerable vibration occurred and the pilot elected to land straight
ahead. As cyclic was appl ied to slow the aircraft , tail rotor effect was lost and the fuselage commenced to rotate. The pilot was
able to land t he aircraft without further subst ant ial damage.
The pilot was distracted by the person acting as a marker who was slow to reposition for the next swath run. As the pilot turned
the aircraft to avoid the marker, the rotor blades struck t he cable. The pilot considered that he may have been f urther di stracted
by the need to monitor the spray pressure gauge, as he was expect ing the chem ical su pply to become exhausted.
C2N
8311048
Instructional-dual
C2N
Wentworth, NSW/Adelaide, SA
8341024
38
2844
568
Instrument Rating Class 4
and Flight Instructor
After observing rapidly deteriorating conditions ahead, both pilots studied their maps to choose the best way to turn in order to
retrace their flight path while avoidi ng the surrounding high ground. While neither pi lot was monitoring the progress of the f light,
the aircraft entered fog. A rapid pull-up was initiated as trees were sighted directly ahead of t he aircraft , however the starboard
wing and the tailplane were damaged as they passed through the treetops.
VH-UXI
After landing on a pre-selected area adjoinin g a main road, the pilot con sidered that the area was too confined to perm it a safe
departure with two persons on board. Arrangements were therefore made to uplift the passenger from a nearby alt ernate site.
While the helicopter was being hover taxied for takeoff, the pilot was distracted by a vehicle on the main road. He then realised he
was approaching power lines and whi le turn ing away from the lines the tai l rotor hit a tree.
The pi lot was preparing to take off from a paddock in order to check that cattle had been mustered cl ear of the area. Almost
imm ediately after becoming airborne the helicopter moved forward and the left skid became caught under a fallen tree stump.
The helicopter pitched forward and the rotor blades struck the ground, resulting in separation of the blades. The tail boom was
also severed.
07 Aug
1225
Commercial
Injuries
Record
number
C1N
Commercial-aerial ag ricu lt ure/baiting
20 Aug
Cessna A 1888 A 1 VH-TZS
8321062
Trundle, NSW/Trund le, NSW
1100
Trundle, NSW
10000
Unknown
Agricu ltu ral Class 1
Commercial
47
As the ai rcraft was f lown along a fence line during a spraying operat ion, t he right w ing struck a branch of a dead tree. The pilot
f lew t he aircraft back to the strip and carried out a normal landing.
The pilot subsequently reported that the branch struck was part of a tree which had fallen across the fence line. The branch
merged into the backgrou nd of other t rees and had not been sighted. Forward visibility had also been affected by s pray on the
windscreen.
The pilot was not in current flying practice and had limited experience on the ty pe. On an earlier flight, he had had difficulty in
maintaining the desired airspeed, and reported that in an effort to correct this fault he had been concentrating o n the airspeed
indicator. He was continuing to monitor this instrument as he moved to deploy the dive brakes, and did not realise until after the
aircraft had stopped that he had been manipulating the tow cable release lever.
Commercial-aerial mustering
Shirlo Station, Old./Bollon, Old. 37NW
3000
750
None
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
08 Aug
Non-commercial- aerial mustering
C1S
Cessna 182 P VH-FYP
1600
Riveren Station, NT 28NE
Riveren Station, NT/Riveren Stat ion, NT
834'1025
Private
42
5021
4708
None
The pilot was attempting t o move a small mob of cattle through a gate into an adjoinin g paddock. He subsequen tly stated t hat he
had been operating at about 50 ft ag l, bu t wh ile manoeuvring with about 20 deg of bank the left wing struck the ground. The
aircraft cartwheeled, its back was broken and the pilot was rendered unconscious for more than 2 hours. There was no eyewitness to the accident and the pilot had not lodged flight detai ls. Rescue was effected the next day.
Sufficient airspeed had not been maintained while manoeuvring at low level, and a stall had developed which the pilot had been
unable to correct in the limited height available.
Instructional-solo-supervised
C1 M
10 Jui
Schneider ES-609 VH-GGO
1450
Beaudesert, Old.
Hardie Field, Old./Hardie Field , Old.
8311044
162
92
Glider Rating
Private
50
The pilot was returning to land after attempting to carry out some handling practice in conditions of deteriorating thermal
activity. He became established on final approach and selected dive brakes out but the glider continued to f loat. Unable to land
on the strip, the pilot planned an outlanding in an adjoining paddock but the glider overflew this area and f inally landed in another
paddock.
03 Aug
Hughes 269 C VH-ARG
1400
Ballon, Old. 37NW
Commercial helicopter
Aircraft type & registration
Location
J\
·~
Cessna 150 G VH -KUR
Yarra Glen 4ENE
55
Non-commercial - pleasure
C1N
Yarra Glen 4 ENE/Lilydale, Vic
8331024
812
119
Instrument Rating Class 4
Due to deteriorat ing weather the pi lot elected to cancel his proposed f light. While taxi ing t he aircraft back to the hangar, a strong
wind gust lifted t he left w ing. The pilot applied power, left ai leron an d rudder but t he ai rcraft became airborne. The throttle was
closed and the aircraft landed heavily on the nosewheel and left wi ngtip.
The flight manual for t he aircraft recommends that the elevator be in the neutral position when tax iing into w ind. On t his
occasion, the pilot taxied the aircraft w ith f ull up elevator into the wind of 25 kt which was gusting to 50 kt.
03 Sep
Piper 28 R180 VH-KI E
Non-commercial - pleasu re
C1 N, P3N
0700
Wubin, WA 3N
Wubin, WA/Wubin, WA
8351022
Private
20
105
45
None
After a short flight, the pilot made a down-wind approach to land at the strip. A go-around was made due to the high ground speed
and a second approach carried o ut into the wind. During the round-out the left wing struck a bush. The pilot attempted a goaround again but the aircraft struck a windsock post, separat ing the right win g. The aircraft came to rest on an adjacent road.
The pilot had had little sleep prior to undertaking the fl ight. The second approach was made w it hout flap and the pilot misjudged
the landing flare during whic h directional control of the aircraft was lost.
A viation Safety Digest 119 I vii
..
I
�FINAL REPORTS (The investigation of the following acc idents has been completed)
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Rating
FINAL REPORTS (The investigation of the follow ing accidents has been completed)
Injuries
Record
number
10 Sep
Amer Air 5 B VH-FXO
Non-commercial-pleasure
C1N, P3N
8321070
Goulburn, NSW/Goul bu rn, NSW
1600
Goulburn, NSW
34
95
3
None
Private restricted
The flight in the local area was terminated because of deteriorating weather condit ions. The pilot reported t hat he was aware that
windshear was common on approach to the selected strip and he therefore carried out a steeper than normal approach. The
aircraft porpoised on landing and the nose gear strut was torn off after fracturing as a result of a heavy touchdown. The aircraft
slid to a halt three-quarters of the way along the strip.
The pilot had only limited experience on the aircraft type. Some turbulence had been experienced during the final approach and
the aircraft touched down heavily before the pilot was able to adopt the correct att itude for the landing flare. Go-around power
was not applied until after the aircraft touched down following the second bounce, but the nose gear strut had already fai led. The
propeller struck the ground with full power still applied.
14 Sep
Cessna 172 M VH-WYK
Non-commercial-business
C1N, P1S, P1N
1840
Cloncurry, 159N
Wurung Stn. No. 2 Bore/Wurung Stn. H'stead 8311057
Private
21
903
830
None
The aircraft had landed at a bore site and was to transport the crew of a helicopter to a nearby homestead. The engine had been
left running and almost immediately after boarding the aircraft the passengers realised they had not brought their water flasks
from the helicopter. After leaving through the right side door, the helicopter pilot walked behind the aircraft but the spotter
moved forward, ducked under the wing strut and saw the propeller disc too late to avoid it completely.
The spotter was familiar with fixed wing aircraft and helicopters but had been flying continually in helicopters for several days
and was in the habit of going ahead of the helicopter to avoid the tail rotor. He was tired and in a hurry so as not to delay the
Cessna 172 which had li ttle time to spare for the return flight before last light.
15 Sep
1500
Private
Cessna 172-P
VH-ESO
Bundaberg, Qld. 18SW
59
Non-commercial-pleasu re
Bronte (N Gayndah)/The Cedars ALA, Old.
8486
8200
None
C1 N
8311058
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours on Type Rating
Hours Total
Injuries
Record
number
C1N
Trial -Race-show
Glasflugel Libelle H201 VH-GG V
25 Sep
831 :1062
Donnington Park/Donnington Park
Donnington Park
1330
Unknown
None
35
300
Glider
As part of an airshow display, t he pilot int ended to carry out a high-speed, low-level run. The gl ider was observed to conduct the
manoeuvre downwind but at an apparen tly low airspeed. A pi tch-up and roll to the right followed before the nose was seen to
lower and the airc raft struck the ground whilst still turn ing to the right. The pilot subsequently advised that the aircraft
encountered an area o f heavy sink halfway through the manoeuvre.
The pilot misjudged the speed and height of the glider at t he commencement of t he low-level fly past. He then att empted to turn
and land in the oppos it e direction but did not mai ntain sufficient ai rspeed for th is manouevre.
27 Sep
Cessna 152 VH-BUQ
Instruct ional - solo-supervised
C1 N
0915
Redcliffe, Qld.
Redc liffe, Qld./Redcliffe, Qld.
831 1063
Student
23
25
25
None
During a pre-solo dual check the stu dent had flared the ai rcraft slightly high and used insufficient rudder to keep the aircraft
straight on t he runway after land ing . The student was debriefed and commenced so lo practice. On the second touch and go
landing which was slightly righ t of centrel ine, th e student set takeoff flap and app lied power and the aircraft veered to the left.
Right rudder was applied , then the takeoff abandoned. The aircraft left the stri p and ran into a ditch.
The instructor authorised an inexperienced student to carry out solo touch and go c ircu its in a 5 kt crosswind. On approach , t he
st udent set the elevator tri m nose down. During the subsequent attempted takeoff at tention was diverted from the operat ion of
the aircraft when takeoff f lap was selected and directional control of the aircraft lost as it turned into wind and left the strip.
29 Sep
Piper PA28-161 VH-RQQ
Instruct ional - solo-supervised
C1N
831 1065
Archerfield, Qld./Archerfield, Qld.
0905
Archerfield, Qld.
17
29
29
None
Studen t
After completing a series of dual c ircuit s and landings, the student was approved to conduct his second solo flight. A normal
ci rcuit was flown but the aircraft landed in a flat attitude and bounced. Appl icable correct ive act ion was not taken and the airc raft
porpoised until the nose gear co llapsed. The aircraft came to rest off the side of the flight stri p.
The pilot was carrying out a flight of about 100 km. On arrival at the destination, turbulence, heavy rain and hail were encountered.
As similar conditions were also present at the diversion airfield orbits were carried out until conditions improved. During the
subsequent landing on wet grass the aircraft was affected by a tailwind gust, and to avoid an overrun the pilot attempted to
ground loop the aircraft which struck a fence post during the manoeuvre.
Before departure the pilot did not obtain a weather forecast for either the destination or the diversion airfield.
'
VH-IEV
Commercial-aerial agriculture/baiting
C1M
Cessna A1888 A1
16 Sep
8311059
Ayr, Qld.
Ayr, Qld./Ayr, Qld.
1530
11874
11600
Agricultural Class 1
Commercial
38
Because the alternator was defective, the pilot was attempting to start the engine using jumper leads connected to a pair of
batteries. The engine wou ld not turn over and the pilot considered that the starter motor drive had jammed. He attempted to
rectify this situation by turn in g the propeller by hand. After two turns the engine suddenly fired and ran up to full power. The
aircraft jumped the wheel chocks and collided with a parked aircraft.
The pilot reported that he was not attempting to hand start the engine and was only trying to free the starter drive. When he left
the cockpit to turn the propeller, he had left the magneto switches on and the throttle in the full open position. The park brake had
been applied but was not sufficiently strong to restrain the aircraft under full engine power.
Instructional-solo -supervised
C1N
Cessna 152 VH-BTF
16 Sep
8321072
Tocumwal, NSW/Tocumwal, NSW
0915
Tocumwal, NSW
23
23
None
41
Student
The student pilot was engaged on a solo training exercise. After takeoff two circu its were carried out in calm wind conditions on
runway 09 before the aircraft departed for the training area. On returning to the airfield, the pilot found that a northerly wind was
now prevailing; however, he elected to land on runway 09. The aircraft touched down heavily on the nosewheel and after three
bounces the nosewheel collapsed.
During the approach the pilot concentrated on keeping the aircraft aligned with the runway centreline and did not initiate a
landing flare. He had limited experience in crosswind landing techniques.
Commercial-aerial mustering
C1 N
20 Sep
Hughes 269-C VH-KKC
Mount Ringwood, NT/Mount Ringwood, NT
8341028
1600
Adelaide R20 SE
3050
2600
None
Commercial helicopter
38
The pilot was mustering buffalo, some of which would not leave a billabong. During attempts to move them the helicopter was
operated very low over the water until its tail rotor struck the surface. The helicopter began to rotate to the right, and left pedal
was ineffective. It sank in about 1.5 m of water and the pilot swam to shore after a brief inspection of the helicopter.
24 Sep
1100
Student
Cessna 152 VH-WSU
Warrnambool, Vic.
51
Instructional-solo-supervised
Warrnambool, Vic./Warrnambool, Vic.
27
27
None
C1 N
8331028
Following a period of dual training in light crosswind conditions, the pilot was authori sed to carry out his fifth period of solo
training. On the third landing, the aircraft touched down on the main wheels initial ly, and immediately after the nosewheel
touched the ground the aircraft veered sharp ly to the right. The pilot was unable to regai n control of the aircraft which ran off the
strip and into a ditch.
viii I Aviation Safety Digest 119
Aviation Safety Digest 119 I ix
�FI NAL UPDATES (The investigation of the following accidents has been completed. The information is
add itional to that previously printed in the prelim inary report)
FINA L UPDATES (The invest igat ion o f t he foll ow ing accidents has been completed . The info rmat ion is
additional to that pre vio usly printed in the prel iminary report)
Date
Pilot licence
Da te
Pilot l icence
Record number
Age
Hours total
Hours on type
Rating
17 Jun
Commercial
8321 050
36
1650
650
Inst rument Rati ng 1st or Class 1 and
Fl ight Instructor
20 Jun
Sen ior Commercial
8321051
39
14700
500
Inst rumen t Rati ng 1st or Class 1
Record number
Age
Hours total
Hours on type
Rating
03 Jan
8321004
Private
38
125
18
None
The pilot had lim ited experience on tailwheel aircraft. There was a crosswind of about 10 kt at the same ti me and adequate
compensation for these conditions was not made.
02 Feb
8321016
Commercial
33
3600
2800
Agricultural Class 1
The propeller hub had fai led as a result of fatigue cracking, allowing one propeller blade to become detached. The hub was of the
oil-filled variety, but examinat ion revealed that no oil remained in the hub at the time of failure.
04 Feb
Student
8351004
33
60
60
None
05 Feb
8321018
40
Gl ider Rating
44
Glider
240
The instructor had simulated a tow cable failure and the student had reacted by banki ng the airc raft more steeply than expected .
Neither pilot was subsequently able to recall the accident sequence and recovery actions attempted during the spin could not be
determined. Actions required in the event of a cable break had been discussed with the student during prev ious t raining but no
practical demonstrations had been given.
12 Feb
8311010
Commercial
35
7000
1500
Agricu ltu ral Class 1
The eng ine had lost power as a result of water ingestion. Despite thorough checking of t he fuel drum and pum p used and t he
ai rcraft fue l system, the source of the water contamination could not be determined. However, the fuel pu mped into the aircraft
had not been fil t ered and samples had not been taken from all the drain points at the co nc lusion of the refue lling operat ion.
02 Mar
Private
8351007
38
1108
420
Investigation revealed t hat the cowl cl ips on the inboard side of the cowl had not been sec ured correctly, allow ing the cowl to
open in fl ight and break the outboard c lips.
21 June
Commercial
8331015
19
272
Inst rument Rati ng Class 4 and
Flight Inst ructor
Subsequent exam inat io n established t hat bot h the landin g gear squat sw itch and landing gear unsafe warn ing horn were
servic eable. It is probable th at there was insuffic ient weight on the landing gear to operate t he squat switch.
30 Jun
8311040
None
4
Private
42
1265
A locki ng spring in t he tailwheel steer ing assembly was found to have been fitted incorrectly, allowing excess ive wear to develop.
The steering assemb ly had failed duri ng the landing and the pilot had been unable to maintain d irect ional co nt rol.
30 Jun
8351019
Private
23
206
37
Inst rument Rat ing Class 4
The pilot who was inexperienced on the aircraft type attempt ed to land the ai rc raft in an excessive crossw ind. During the landing
ro ll the left main wheel was held off th e st rip by the ap plicat ion of right aileron. By doing so the pilot den ied himself t he use of
d ifferent ial braking to keep the airc raft st raight dur ing t he landing ro ll.
None
The pilot's standard of flying was being informally checked by the passenger who was a f lying instructor. The passenger
suggested that a practice forced landing be carried out and then closed the throttle. On fin al app roach, the pilot side slipped t he
aircraf t to a low altitude, expecting the passenger to instruct him to go around when the exercise had been satisfactorily
demonstrated. The passenger, however, was expecting the pilot to initiate the go-aro und.
07Mar
8331006
None (not issued or 39
expired)
643
400
None
09 Apr
8351013
Commercial
37
11000
Instrument Rat ing 1st or Class 1
6600
A bearing in the landing gear gearbox had failed. This imposed high loads on t he electric motor which eventually failed on
extension. Debris from the fai led bearing had lodged in the emergency handle engaging slot , thus preventing t he pilot from
lowering the gear manually.
8351014
14 Apr
Pr ivate
20
228
177
None
The investigation established that the aircraft was stalled whil e in a steep turn in close proxim ity to the ground.
21 Apr
8341013
Private
Instrument Rat ing Class 4
56
1000
600
The collis ion with the taxiway light resulted in the over-centrelock being broken and the nose gear co ll apsing. The reaso n for the
disengagement of the over-centre lock could not be determin ed.
30 Apr
Commercial
8331013
50
20000
7000
Agricu ltu ral Class 1
Although the pilot had operated from the strip many times over nine years , he was unaware of t he po wer lines. He did not see t he
lines during an aerial inspection or on the first spreading fl ight. The lines were stru ng across a valley between a pol e hidden by
trees at the top of a ridge and a pole lower down on the other side. The span was 900 m and light condi t ions were du ll.
04 Jun
8321045
Private
33
690
590
None
The investigation revealed that the aircraft was c limbed steeply after takeoff. Suffici ent airspeed was no t maintained and as f lap
was retracted the aircraft stalled.
06 Jun
8341017
27
Commercial
321
150
Agricu ltural Class 2
The pilot was inexperienced in agricultural operations. Although he did not consider the stri p to be entirel y sat isfactory, he knew
that other pilots had used it successfully. Directional control was made difficul t by the ro ugh surface o f the strip and crosswind
gusts.
08 Jun
Student
8341018
36
x I Aviation Safety Digest 119
17
17
No ne
A viation Safety Digest 119 I xi
I
I
i
~
�~
yin your homei
\~
~
Flying deck chair
An ' unlicen sed aper.a.tor' of a flyi ng deck chair which soared to a n altitude of 16 OOO feet in the U.S.A. was
fined $1500 for various Air Regula tion infringements .
During his 90-minute fligh t aloft with the aid of 42 helium-filled weather balloons, the budding aerologist
' intruded h azardously in to federal airways a nd was spotted flying near several com m ercia l jet aircraft ' .
H e finall y crashlanded after sh ooting o ut some of the balloons with a n a irgun •
xii I Aviation Safety Digest 179
Flying is a pursuit which attracts devotees and
gen er ates en th usiasm as does n o other. Of those who fly
there is probably non e more en thusiastic than the pilot
who builds his own a ircraft. H omebuilts have become
tremendously p opular in Austr alia in recen t years, wi th
the number of pilots building ultralights and minim um
aircraft steadily increasing . It is a highlight in any
p ilot's career when , after what in most cases has been
many years of hard work, a homebuilt is ready for its
first fligh t.
There is an understandable in clination for the builder
to wish to fly h is aircraft as soon as possible. Depending
on circum stances - th e aircraft type, the pilot's
experience etc. - this may not be a problem. On the
other hand, fl yin g a homebuilt can be demanding in the
early stages when adj ustments may still need to be
made to such asp ects as the aircraft's rigging, or the
pilot is still becoming familiar with the machine. As the
following distressing accident review ill u s~te s ,
inexperienced builder/ pilots should temper with caution
their natural enthusiasm to fly t heir aircraft at the
earliest opportunity, ensuring first that they are
thoroughly conversant with all aspects of the m achine 's
performance and characteristics.
The accident
A p ilot with around 240 hours experience had spent
about eighteen months constructing a Vari-E ze, assisted
by two engineers. The initial test fl ying was conducted
by an experienced p ilot, approved by the D epartment
of Aviat ion under the terms of a P ermit to Fly. After
five hours had been flown all of the airworthiness
aspects of the test schedule had been completed, so t he
builder, understandably eager to fly his aircraft,
arranged his first flight.
In the week before the accident he flew two sorties in
Aviation Safety Digest 119 I 13
�Use your warning systems
Just after lift-off the co-pilot of a Cessna Citation
noticed that the r ight-hand nose locker door was open .
The captain throuled bark on the right engine and
reduced speed as much as practicable. However, the
door separated from th c a irrrnft shortl y afterwards and
landed near a Primary School. It had also st ruck the
leading edge of the Citation's right mainpla ne a nd the
lower right engine cowl, causing minor damage. The
captain returned fo r a n immediate landing and while h e
was turning on to left base over a built-up area a
3-kilogram bag fell from the nose locker. The aircraft
was landed without further mishap.
The nose locker doors
These doors are fas tened on the C itation by two toggle
hook latches (sec photograph) . The door is then locked
by using the key-operated lock between the two latches.
While the key lock assists in securing the door in flight ,
note t hat the latches are the prime dev ice for this
funct ion . The front latch also operates a microswitch
which illumina tes a 'door unlocked' warning light in
the cockpit when the latch is not closed.
During the technical investigation it was determined
that the door and all latches were full y ser viceable. If
the door had been correctly latched it would not have
been possible for it to have come open a nd separate in
flight.
a Grumman AAl-B a nd one sortie in the rear seat of a
friend 's Vari-Eze. Prior lo h is flight in his own VariEze he was given a briefing on the aircraft by th e pilot
who h ad carried out the initial test fl ying .
W itnesses saw the aircraft lift off into a normal clim b
attitude. It had been ai rborne for a distance of about 50
metres and had climbed to a h eight of 15 or 20 feet
when it descended and struck the runway heavily in a
tail-down attitude. The m ain landing gear spring legs
were sp layed outwards consid erabl y, and the pusher
propeller contacted the runway and was shattered.
The aircraft rotated rapidly into a steep nose-up
atti tude of about 60 degrees and climbed to a height of
about 50 feet. It rolled quickly, became inver ted and
then cr ashed back onto the runway in a relatively wings
level but upside down attitude. T he aircraft slid off the
runway and came to rest in verted after a ground slide
of 55 metres. The pilot was killed.
Analysis
Notwithstandi ng h is three fl igh ts in the past week, the
p ilot's recent and on-type experience were minimal,
and this was assessed as being a major cau sal factor in
the accident. His sin gle flight in the rear seat of a VariEze, while satisfactory for familiarisation purposes, was
of little value in terms of manipulative experience.
As far as actu al flyin g techn ique was concerned , the
Vari-Eze's O wn er's Manual adv ises p ilots that because
of the canard wing, on takeoff pilots who a re unfamiliar
with the aircraft sometimes visually m isjudge the nose
attitude, believing that they have over-rotated to a
14 I Aviation Safety Digest 119
nose-high attitude. This false impression may lead the
pilot to level off or even descend soon after lifting off.
In this instance the aircraft became airborne and
then, still at fl ying speed , contacted the runway in a
tail-down attitude. Th is sequence was consistent with
the warning contained in the Owne r 's Man ual . Having
hit the runway, it seems probable th at the pilot overcorrected by ra pidly rotating h is m achine to an extreme
nose-high a ttitude, and in so doing changed a relatively
minor acciden t into a catastrophe. As a result of the
extreme nose-high att itude the aircraft became airborne
again , 'mushed' throu gh the air more or less
horizontally un til , because of the excessive angle of
attack, it stalled, flicked on to its back, and crashed.
Summary
The ill usion of over-rotation on takeoff, and the correct
technique to use , were adequately covered in the
O wn er 's Manual. Unfortunately, through a
combination of inexperience, lack of recency and ,
perhaps, over-enthusiasm to fly the aircraft he had
built , this pilot fell into the trap. Those pilots who
achieve the demanding and adm irable goal of
constructing th eir own aircraft must remember that,
before conducting their fi rst flight, a careful study of
guidance material, dual training whenever possible, and
thorough d iscussions and briefings with pilots who a re
experienced on type a re essential •
View of right nose locker door in position. Notice damage to
door and that it can still be latched.
Analysis
The procedure used by the Compan y to close the nose
locker doors consisted of fas tening the latches an d then
securing t he key-operated lock. To check that the key
lock had in fact operated, the forward latch was then
re-opened and the locker door pulled sligh tly, after
which the forward latch was refastened.
According to the Company's Chief Pilot , problems
had been experienced with the microswitches o n the
front latch which on occasions resulted in the 'door
unlocked' warn ing light illuminating even though the
doors were securely latched. Accordingly, crews had
been briefed tha t if during th e pre-start checks the
warning light illumina ted and the crew wcrC' certain the
doors had been properly closed, then the light could be
ignored; the microswitch was to be adjusted before the
next fl ight.
In t his instance the co-pilot dosed the r ight locker
door in the ma nner described above. H e felt certain
th a t he 1·efastencd the forward latch after checking the
security of the key lock. When e lectrical power was
connected during the prcstarl checks he noticed the
'door unlocked' warn ing light had illuminated a nd told
the ca ptain. The captain asked the co- pilot if he had
secu red a ll the doors a nd , on receiving a n affirmative
response, deselected the warn ing light. The m atter was
then forgotten until the door came open in fli ght.
Comment
From the findings of the technical investigation it seems
probable that the co-pilot did not close the front latch
properly after checking the security of the key lock.
C learly it was largely to guard against this possibility
that the warn ing light was fitter! a nd, as the pilots
sub sequentl y reported, the light did indeed se rve that
purpose.
By deciding to ignore the warn ing light because they
believer! the ' door unlocked' warn ing system to be
d efecti ve, the pilots were deprivin g themselves of the
last safety ch eck they had on the securit y of th e nose
locker door.
Whil e the microswitch for the light had a history of
giv ing erroneous indications the practiC'c of ignoring it
seem s questionable. The Burcau of Air Safety
In vestigation 's files con tain many inc idents and
accidents which can be partl)' a ttributed lo pilots either
de-activating or ignoring warning devices. Stall warning
horn s and undercarriage warning systems are two
which feature regularly in such occurrences: pilots
sometimes turn them off because they find them
distract ing or believe they do not need them. T he sam e
rat io nale appl ied in this inciden t.
An in termittently reliable warn ing device is
unquestionably irritating and distracting, but if you
choose to ignore it you ru n the considerable ri sk, as this
incirlent proved, of doing so when the device is in fact
doing the job for which it was designed . The only sure
course of action in these circumstances is to write up
the unserviceability in the maintenance release to
ensure it is rectified. It is sign ificant to not e that, while
wi th this aircraft p ilots were briefed to accept the
illumination of the ' door un locked ' light if they were
certain the door h ad been secured, and write up the
faulty microswitch before the next flight, there were no
reported defects in the maintenance release. Probably
an element of complacency had crept in regarding the
ligh t.
A comme nt on the procedure used to check the
security of the nose door is also warrant ed. T he prime
devices for keepi ng the nose door secure in ni ght are
the two latches, not the key lock. Therefore, to open
the front latch to check thc key lock would seem to
serve little purpose. Indeed, it only increases the
possibility of leaving the front latch unlocked and, if
that happen s, the key lock wi ll nol necessari ly preven t
the nose door fro m 'peeling' when subjected lo ai1·flow
and eventually separating from the aircraft •
Aviation Safety Digest 119 I 15
�Human factors
Worldwide statistics indicate that between 70 to 80 p er
cent of aircraft accidents involve human performance
failure as a significant causal factor . The trend towards
an increasing proportion of human fai lu res compared
with technical failures has been going on for some 15
years a nd is continuing. Human performance failure
can be m anifest in a ran ge of activities: pilots, flight
engineers, air lraffic controllers, aircraft designers and
m aintenance personn'el, for example, constitute som e of
the groups who at times contribute to an aircraft
accident.
Any readers who doubt the high percentage of
human factors in Australian aviation accidents are
invited to review the past few editions of the Aviation
Safety Digest. The articles presented, like most of those
contained in the Digest since its inception , are
representative of Australian accidents. It will be noted
that the great majority involve som e elem ent of huma n
performance failure. These failures cover th e full range
of human involvement in aviation, such as aircraft
design, m ainten ance procedures, cockpit drills and
piloting skills.
16 I A viation Safety Digest 119
This article addresses two air safety occurren ces in
which the pilot in each case was, to a large exten t, the
victim of self-imposed stresses .
Because of their insidious nature, self-imposed
stresses constitute one of the greatest dangers a pilot
can face. Often , pressures build up gradually and in a
cumulative fashion, but because they may not be
immediately apparen t, the p ilot may not appreciate the
situation in which he has been placing himself until he
suddenly finds himself faced with an alarming problem.
There is often an irony in tha t, had he realised the
p'.essures he was graduall y imposing on himself, the
pilot could have relaxed those pressures and thus
avoided his self-generated problems.
VFR flight into IMC . ..
The first occurrence deals with one of the most
d an gerous situations in General Aviation: that of a pilot
trained only for VMC (Visual Meteorological
Conditions) flight attempting to fly in IMC (Instrument
M eteorological Conditions).
T he pilot h ad p lanned a trip away with a group of
friends. There seems to have been an element of
complacency in the fl ight planning as no allowance was
made in the fl igh t plan for the effect of the forecast
wind velocity on the aircraft's heading and
groundspeed. The forecast wind speed at the planned
cru ising heigh t of 5000 feet was 15 knots which, given
the aircraft's TAS of 140 knots, could have significantly
affected navigation.
Following takeoff from a General Aviation
aerodrome, the pilot was cleared to climb to 5000 feet.
O n con tacting D epartures, he was given a series of
radar vectors because of conflicting traffic. This
disconcerted him as he felt some p ressure from the
instructions a nd also believed - incorrectly - thal his
flight was proving to be a nu isance to the air traffic
controllers. Thus, he had quickly placed himself under
pressure. At this stage weather conditions took a hand,
for on reaching 5000 feet the pilot found himself in
cloud. It seems probable that, flustered by inflight
procedures and under the su btle but powerful selfimposed pressure not to disappoint his passengers, the
pilot either fai led to assess the weather conditions
adequately a nd in time; or he decided he should 'press
on' in the hope that he would soon be clear of the
cloud.
In the event, matters quickly got out of hand. Flying
the radar vectors would have been a simple matter in
V MC, but in cloud the unrated pilot simply could not
cope. H e also found that he had to divert his attention
to try to reassure his passengers, who were rapidly
becoming alarmed by the fairly obvious inability of the
pilot to manage. Overloaded and unable to deal with
the situation which he had allowed to develop, the pilot
temporarily lost control of the aircraft. While he was
making a radio call the aircraft went into an
uncontrolled left-hand turn. A complete orbit was made
while the p ilot tried to sort things out. The orbit was
observed by A TC, who immediately con tacted the pilot
and facilitated his descent back into visual conditions.
Even this exercise, however, provided some trauma :
untrained in instrument flying techniques, the pilot
found the descen t difficult to effect because of his uncoordinated control inputs and coarse adjustments of
engine power. Indeed, he initially inadvertently put the
aircraft into a climb, goin g above his assigned altitude
by a sign ificant m argin .
However , unlike m an y pilots who h ave placed
themselves in this fearful predicament, this pilot, aided
by ATC, th e thin cloud layer - and a considerable
am ou nt of luck - finall y broke clear into VMC below
the cloud while still in control of bis machine.
Hopefully, the account of this pilot's experience will
help others to avoid similar potentially disastrous
occurre nces. The key to this lies in being able to
recognise when self-imposed pressures a re building up,
and acting quickly and calmly to relax a nd remove
those pressures.
Before discussing the second incident, a comment is
warranted on the pilot's action of climbing to his
assigned altitude of 5000 feet in to IMC , without
advising ATC. The pilot later stated that he felt he had
to comply with his clearance. This is not the case: any
pilot who is given a clea rance which is operationally
unacceptab le o r inconvenient may request a different
clearance; while a p ilot faced with an emergency may
act without a clearance, but must inform ATC as soon
as possible. In this instance the pilot possibly became
confused about his responsibilities and prerogatives
because of the pressure under which he had placed
himself.
Fatigue and stress
A twin-engine commuter aircraft was destroyed when it
crashed immediately after a night takeoff. The
investigation revealed that the pilot had become
distracted during the takeoff roll, and also had not used
the artificial horizon positively to establish a precis~
takeoff attitude. Further, it became clear that a large
number of stresses had grad ually been building up on
this pilot, and while human factors are generally of an
intangible nature, tqere is little doubt that these played
a significant part in the eventual loss of control of the
aircraft.
The flight was scheduled to transport freight between
two busy regional centres. This freight was to be
transferred from another of the Company's aircraft
which, however, was diverted because of weather.
T here was some minor confusion while the Company
managemen t rearranged schedules, with the inevitable
delay and the b ui ld up of the subtle pressure to catch up
that delay.
Because of the reorganised schedule, the
precalculated load documentation was no longer
appropriate. Caught up in the replanning of a number
of matters, the pilot forgot to prepare a new load sheet.
H e did not realise his omission until, d uring the pretakeoff checks, he came to the calculation of takeoff
speeds (which are weight related).
Lining the aircraft up on the runway, the pilot
applied the park brake while he completed his
calculations. It seems that subsequently he d id not full y
release the park brake, which caused the aircraft to
accelerate slowly during the takeoff roll. It was the need
to check the position of the handbrake, as the aircraft
passed through about 85 knots, that distracted the pilot
at a critical stage of the takeoff. Al the same time as he
was checking the handbrake position, he also decided to
select continuous water/ methanol injection to ensure the
takeoff could be made.
Despite the initial slow acceleration, investigation
later confirmed that there was no reason why a safe
takeoff still could not have been effected . H owever,
with his routine interrupted, the pilot ·- whose
concentration appears to have been adversely affected
- failed to follow normal after-lakeoff procedures in
establishing a positive rate of climb, with the result that
he new the aircraft in to the ground about 440 metres
from the end of the runway.
Apart from the preflight frustrations to which this
pilot had been exposed, it also turned out that he had
been the su~j ecl of other external stresses for some
period . H e was resettling his family in a new city and
was living in a partly-furnished home. H e had also only
recently completed the demanding conversion course on
to the aircraft type; while at the same tirne he had been
studying for exams to upgrade his pilot licence. Finally ,
he had already flown on the day of the accident a nd ,
while he had been given the correct amount of crew
rest, he had only been able to sleep for three hours.
It is not unreasonable to suggest that, from the
picture which emerges, a range of pressures and stresses
- the insidious 'human factors ' - had built up on this
pilot, and as his to ur of duty progressed their
Aviation Safety Digest 119 I 17
�PILOT CAPABILITY AND WORKLOAD
NOMINAL TASK LOADING
PRE - FLT
TA I
FLIGHT PHASES -TIME - - - - - - -
The information-processing relationships between pilot capability and workload at the various phases of flight. Miiier, C.O.,
19~9 .. ' Human Factors in Accident Investigation ', paper presented at Dutch Airline Pilots Association symposium Safety and
Efficiency: the next 50 years. A Symposium on Human Factors in Civil Aviation. The Hague.
cumulative effect began to act on hi m, to the extent
that eventually, his performance was seriously
derogated.
Comment
The two occurrences rev iewed in this article were not
due to deliberate misbehaviour by the individuals
involved, but rather were the by-product of a series of
circumstances - some of which admittedly were selfinduced - which put the pilots in a position where the
probability of their making an error was high.
If occurrences like these are to be avoided, pilots
must develop a keen and responsible appreciation of
their capabilities and be able to identify at an early
stage the first signs that th ey arc either being exposed,
or arc submitting themselves, to excessive pressure.
They must then not hesitate to take remedial action,
even if that means terminating or cancelling flights. A
similar awareness, and a readiness to act sooner rather
than later, should also be demonstrated by all flying
supervisors, ranging from the instructor authorising a
student pilot to the operations manager despatching
professional aircrew e
18 I Aviation Safety Digest 119
The smooth teamwork which is generally
characteristic of airline aircrews does not happen by
chance. It is a result of comprehensive and
disciplined training and the thorough understanding
by each individual ofh:is precise responsibilities,
and of where those responsibilities start and end.
Airline managers appreciate fully that uncertainty
over one's role in the cockpit can lead to a
dangerous degree of c-0nfusion: thus, great emphasis
is placed on crew co-operation during training.
Light aircraft pilots, on the other hand, almost
always operate as single pilots and rarely receive
any fo rmal training in crew co-operation. In most
cases it is not necessary. However, when two such
pilots do fly together in a light aircraft and start
'helping' each other on an informal basis, then the
potential for confusion - and perhaps an accident
- is very real.
The accident recounted in this article is a 'classic'
case of confusion arising in the cockpit because of
uncertainty over who was doing what. The accident
itself is reported primarily in the words used by the
two pilots as this most graphically highlights the
important lesson it ·contains.
The accident
A Cessna 172RG had been hired by a reasonably
experienced p rivate pilot to take away on an extended
trip. Before the trip, this pilot decided to take the
aircraft for a local flight to check its cruise performance
against that quoted by the manufacturer. He was
accompanied by a flying instructor who was also going
on the extended trip, but only as navigator: the private
pilot and another friend were going to share the piloting
duties. For this particular aircraft performance check
flight, the private pilot was the pilot-in-command. It
was not intended as an instructional flight.
The performance phase of the check flight was
completed satisfactorily. On the way back to the home
base the private pilot, who was relatively unfamiliar
w ith the Cessna, decided to carry out some circuits at a
satellite airfield in order to become more familiar with
the aircraft. His description of these circuits foUows:
On the way bac.k we didfour touch and go's. My approaches
were high and the aircraft was floating a lot. I was flying the
approaches and the instruc.tor was flying the circuits. He was
doing low-level circuits and putting me 01i to final to save time.
During the l.andings, on the first three, he was retracting the
flaps. I did everything else. On the rollout I would apply full
power and on each occasion when I started to lean over to retract
flaps he would have already taken them up.
At this stage some comment on the private pilot's
background is necessary. H e had a fair amount of
experience in the Beech Baron but, as was mentioned
above, very little on the Cessna 172RG. The gear and
flap selector locations are reversed in the 172RG
compared with th e .Baron. To return to the pilot's
account ...
On the last touch and go instead of leaning across (to retract
the flaps) I selected the [ever straight in front of me, i. e. the
landing gear lever. As soon as I had done it I realised my
mistake and I tried lo put the lever down again.
This then was a major causal factor in the accident
the reve.rse positioning of landing gear and flap fevers
on the different aircraft types, and the pilot's
jnexperrence on the Cessna, contributed to his action,of
inadvertently raising the gear lever while hi'l aircraft
was on the ground. Obviously, pilots changing between
aircraft fypes must be continually aware of such x 0~
significant differences, and must develop a disci ·
system of coek:pit drills to guard against errone
~ ,_,
'conditioned' actions. That is one lesson arising from
this accident.. Of equal interest is the confusion wlii:ch
arose in the cockpit once the initial mistake had'be6n
made. Once again, the lesson is best illustrated by the
private pilot's own words - remembering that he was
the pilot-in-command.
The propeller started hitting the runway. I think I t"Fieil'to
take off again. At that stage the other pilot may have takih '-0/Jer.
We were both aware that the aircraft would not fly. One efus.
pulled off the power and shut the engine down. I was aware of
the aircraft sliding and of the possibility offire. I immliliately
turned off lhe switches and fuel. After the aircraft came to a
halt both men exited rapidly.
The significant point in the pilot's description of the
accident is his uncertainty over who completed the
various. actions taken in the attempt to avert the'cra:sh,
particularly his confusion over who was actualJy· in
control of the aircraft.
.
The instructor in his comments acknowledged that
the private pilot, who was occupying the left-hand seat,
was the pilot-in-command. However, because the
private pilot had in his initial circuits been landing 'too
far down the runway'' the instructor had of his own
initiative been retracting the flaps to assist in the
takeoff. Thus, any routine the private pilot mightd1ave
developed for his touch and go checks was disrupteiL
Because the final landing was satisfactory, the iristructor
left all of the touch-and-go actions to the private pilot.
When the propeller started to strike the runway the
instructor, in his own words, 'immediately too~ over_c
control' of the aircraft, although not realising initially
that the gear had been inadvertently selected up;
Whether or not he was hindered in his attempt to ·
retrieve the situation, or he in fact hindered the 2i16tin-command, is uncertain. Clearly, the pilot-incomma_nd was not aware that the instructor believed
that he (the instructor) had taken control.
0
Comment
The pilot's inexperience on type and the reverse
positioning of the gear and flap levers were major
contributory factors in this accident. This pilot was not
the rrrst to be caught out when changing from a
Beechcraft to another type (or vice versa) in which
certain controls are in reversed positions. Pilots in this
situation need to take extra care in their operation of
systems.
However, perhaps the most useful lesson to COlJ!C out
of this accident for pilots who normally operate siriglepilot airqaft - that is, the great majority of Australian
licence-holders - is the way in which two fairly
(continued on page 21)
Aviation Safety Digest 119 I 19
�Become a weather-wise pilot
Australian accident investigation statistics continue to reveal 'flight into adverse weather
conditions' as a major cause of General Aviation VFR fatal accidents.
Articles in Aviation Safety Digests 105, 106, 109, 114 and
11 7 have in recent years highlighted the d angers faced
by those pilots without instrument ratings who try to
maintain visual flight !n inst rumen t meteorological
conditions. O n the credit side of the ledger, over th e
sa me period there have been man y insta nces o f pilots
either cancelling trips or making timely inflight
diversions because they assessed that weather conditions
were, or had become , unsuitable.
The weather-wise pilot
The basis of safe fl ying operations is preflight planning,
and here, the assessment of the weather forecast is one
of the most importa nt aspects.
By assessing a forecast thoroughly on the ground,
possible courses of action can be considered befo re
takeoff should tha t fc)recast indicate that conditions may
be ma rginal for VFR flight. Too often, however , it
seems that some pilots either do not know wha t their
forecast means in terms of ex pected weather co nditions
or allow external pressures, such as the 'get-home-itis'
or ' it-can't-happen-to-me' syndromes, to influence
sound judgement. T he evidence of this can be seen in
the disastrous experi ences of those Australian pilots who
have had accidents whi le attempting VFR flight in
conditions which clearly did not meet V FR criteria. In
o ther words, it can happen to you . .. so read on!
Reduced to the basics, assessing the weathe r involves
two main compone nts. T he first is that o f being able to
unde rsta nd all of the da ta, terminology, symbology,
abbreviations etc. wh ich are used in meteorological
forecasts. Additionally, a U of the forecast relevant to a
fli ght must be considered so that a comprehensive
understanding of prevailing conditions is achi eved: a
forecast is not something from which selected items can
be read in isolation. Once an assessment of the forecast
has been made, it must then be relat ed to the
circumstances of the planned fligh t - terrain, aircraft
performance, en route facilities , etc. The point he re is
that it is not enou gh simply to collect a forecast a nd
look at it: pilots must be able to translate the data it
presents into an informed appreciation of its likely effect
on their fl ight.
·
P ilots who feel that they are not assimilati ng fu lly the
valuable information contain ed in flight forecasts a rc
advised to refer to the sectio ns on meteorology in either
the VFG or AIP, and to a pproved texts, particularly
the M a nu al of M eteorology.
The seco nd component of becoming a 'weather-wise'
pilot is that of being able to recognise inflight weather
signposts and their warnings. Listed below a re some of
the most common weather phenomena together with
their possible associated effects. No pilot can consider
himself a safe a nd competen t operator unless he can
r~ad, and appreciate the possible consequ ences of, these
signs:
20 I Aviation Safety Digest 119
• a gradual lowering and thickening of the ceiling:
inadequate terrain clearance, possible widespread
precipitation, fog
• a line of heavy, dark clouds: severe turbulence,
dust and poor visibility, hazardous landing
conditions, precipitation , hail
• roll-type clouds: dangerous turbulence, dust and
poor visibility, subsequent precipitation, hazardous
landing conditions
• ragged cloud base: turbulence, variations in
visibility, possible precipitation
• bulbous cloud base: turbulence, possible
precipitation
• an OP,ening in a wall of dark cloud~: this is
sometimes referred to as a 'sucker hole', as
dangerous turbulence, precipitation and poor
visibility may be encountered as the hole is entered
• temperature near freezing: poor visibility in
precipitation, with icing possible on the windscreen
and airframe
• low layer of haze: possible fog or stratus cloud in
the early morning or la te evening; and poor
visibility, especially when looking into the sun
• blowing dust: turbulence; and poor visibility,
particularly when looking into the sun
*
•
•
In addition to th e hazards listed above, there are
other common dangers in Australia which may not
always be so clearly 'signposted ', but which also can
pose a serious threat to aircraft :
• Mountain effects. These a re associated with strong
winds across the crest of a range. Lenticular-type
cloud a bove the mountain and turbulent (broken)
cloud on the leeward side of the mountain may be
present. These phenomena indicate the wind
structure known as 'standing waves' which will
generate areas of turbulence a nd vertical motion
downwards at various intervals downstream from the
range, especially on leeward slopes.
• Low atmospheric pressure. Pilots should also be
aware of the occurrence of relatively low atmospheric
surface pressure downstream from a mountain
range. A pressure altimeter not correctly adjusted
will tend to over-read in such areas.
• Low-level wind shear. T his is often experienced in
the early morning during winter over inland
Australia after a calm clear night which is
accompanied by a surface temperature inversion. In
some instances low-level 'jetstreams' may be present,
in which case the wind strength may ch ange from
calm on the runway during ta keoff to 50 knots or
more a t an altitude of only 2000 to 3000 feet AGL.
• Thunderstorm effects. It is well known that violent
conditions will be encountered inside thunderstorms.
However , there are associated p henomena which can
The above photograph depicts a unique example of a roll cloud over Spencer Gulf, South Australia. The picture was taken at
1.15 pm, 27 November 1977 by the co-pilot of an Airlines of South Australia aircraft while on approach to land. He estimated
the length of the cloud to be 5 kilometres. The camera was pointing west and a further faint roll is just visible to the west of
the main one.
The ship near the centre of the picture was the Danny F, which was 230 metres long. This puts the thickness of the roll
and the height of its base around that figure.
A north-easterly airstream had resulted in humid sultry conditions over most of South Australia, with isolated
thunderstorm s a day or so before the event. An interaction of this air mass with a cooler south-easterly anti-cyclonic flow
towards the South Australian coast undoubtedly contributed to the formation of this well-defined roll.
occur outside the buildup, such as severe turbulence
beneath the cloud; while the stron g surge of cold air
which comes down from th e base in the mature stage
of the storm and extends outwards from the cell over
the su rface can cause wind shifts many kilometres
from the thunderstorm.
•
•
As a final thought , the weath er-wise pilot is also aware
that, when inflight weather conditions do deteriorate
below VFR minima, the 180-degree turn is one of
aviation's best safety devices - as Jon g as it is made
before the aircraft is enveloped by bad weather. Pushing
on into worsening conditions is a recipe for disaster •
•
Who is in control? (eon1in111dJrom page 19)
experienced pilots allowed an element of vagueness
to creep into their operations such that, eventually,
uncertainty existed over who was in control of the
aircraft. The key factor in this was the ' informal'
assistance given by the instructor when he positioned
the aircraft on finals for the pilot-in-command and
then retracted the flaps during the touch and go's.
There is nothing wrong, of course, with a
qualified pilot pointing out to a pilot-in-command
items that he believes need attention, but this is a
different matter from actually completing vital
actions, such as flap retraction , unannounced.
Preferably the pilot-in-command should operate a
single-pilot aircraft as its manufacturer intended: by
himself. In this instance the pilot-in-command would
have been better off flying the whole circuit himself
and going around from unsatisfactory approaches
rather than landing long and finding himself rushed;
or, if he felt he needed guidance on his circuits, he
should have concluded the sortie and organised a
formal instrUctional ride for himself. As it was, both
pilots allowed the line of responsibility to become
blurred to the extent that when an emergen cy
occurred, the uncertainty over who was in control
placed their aircraft and themselves at risk •
Aviation Safety Digest 179 I 21
�In brief
local and overseas
During a night fli ght, the nav/com equipment in a
Boeing 727 failed at 25 OOO feet. The crew traced
the problem to a passenger using an electron ic
poker game. Apparently the device caused a loud
buzzing, interfering with the onboard navigational
a ids.
*
*
During the takeoff run, the right front passenger
door of a Cessna 310 became unlatched. The pilot
attempted to reach across the passenger to secure
the door but was unsuccessful a nd decided to
abort the takeoff. The aircraft skidded off the end
of the runway and down an embankment.
*
*
•
The pilot of a Piper PA-28R relaxed too soon
after a pparen tly coping with a total electrical
failure. Following the failure, he h ad attempted to
lower the landing gear usin g the emergency
method. H e was uncertain as to whether all three
wheels had fully extended because the trim
changes during the lowering were n ot as expected,
and, because of the electrical failure, there were
no visual indications that the gear was down and
locked. His radio, of course, was also inoperative.
After overcoming some difficult air traffic control
problems, the pilot attempted a landi ng and, in
his words: ' A great sen se of relief came over me
when the a ircraft touched down smoothl y on the
main wheels. ' Unfortunately, inadequate
lubrication had prevented the nose gear from
lowering. Return in g again to the pilot: 'I just was
not prepared for the nose to drop as I though t
everything was okay after to uchdown .' The
a ircraft veered off the runway and was
substantially damaged.
*
*
*
On takeoff from an oil rig, a Bell-206 pitched
nose down to the left and struck the water. In itial
in vest igation indicated that the refuelling hose h ad
hooked on the left skid .
*
*
•
A student helicopter pilot's foot slipped off the
rudde r pedal wh ile the helicopter was in the
hover. The heli copter began to turn and a skid hit
the groun d: the a ircraft then rolled over onto its
side. The pilot later stated that he thought his foot
slipped off the pedal because the soles of his shoes
were wet.
*
*
*
One engine of a Piper PA-31 lost power after
takeoff and the pilot m ade a forced landing on a
city street. The aircraft, with its gear up, slid for
almost a block and a half, hitt ing two cars and
then burning. The investigation disclosed that the
aircraft had been refuelled with A VTUR prior to
the flight •
22 I Aviation Safety Digest 119
Fuel metering systems for reciprocating engines
Oo you fl y a piston-engine ai rcraft? If so, what type
of fuel me tering system does it have ·~
ls it a float -I) pc carburettor , an injenion-type
carbu rettor, or perhaps direct fuel injenion ?
So what, you Illa)' say. \'\'hat good is it lO you to
kno\\' what type of system it has?
That some pilots un fort una tel y do not adequa tely
understand the basics of the power p lants they
operate is appare nt in the nu111ber of aircraft
accidents or incidents associa1ed wit h fa ulty engine
handlin g. Engine handling is a fundamcn1al aspect of
piloting lX>\\TITd aircraft and rnrTtTt engine handl ing
is essential fo r safr operat ions . Impli cit in the oftenused term ·good engine handlin g' is the assumptio n
I hat a pilot has a sound knO\\ ledge of the
com pont>ms and mechanical operation of ai rcraft
en gines.
An understanding of the fuel mete ring system of
you r aircrah 's engine/s is an importan t part o f
engine handli ng. for the charannistics of the system
play a large pan in determining the way in which an
engi ne will perfornr in ,·aryi ng circumstances.
To assist pilots in understan di ng the characteristics
of fue l 1nC'tcring systems, tables comparin g the
characteristics of the three' types of systems appear
opposite.
One of thl' most persistent engine mishandling
ocn11TC'nces in Australian general m·iation is that
associated wit h carburetto r ic ing. Fro m the tables it
is ob\·ious that the syste m most susceptible lo
carburetto r icing is l he 11oat -l ypc carburett or.
I [own er . pilots flying aircraft \\'ith fucl-inj erted
engines would be \\ rong to as~u11 1 c that thl')' arc not
susce ptible to engine icing hazards.
An iclcs in pas! A1•iatio11 Sa/i{J' n1:f!,CS/S, in particular
the lift-our chart in 0lo . 108/1979, detail the
conditions under which carburettor icing may occur.
All pilots who operate reciprocating engines must
know those conditions.
Too often re po l'I s quote ' lack of fa111 iliari l y with
aircraft' as a fartor in accident~ and incidents. Get to
know your aircraft berter by referring lO the \'arious
handbooks ;l\·ai la ble and discussing its characteristics
with your flying instructor or a LAME •
1. FLOAT-TYPE CARBURETTORS
Advantages
Disadvantages
Simplicity of design.
Severe icing hazards.
Ease of overhaul.
Poor fuel atomisation.
Cheapness of replacemen t parts.
Unequal fuel distribution and sensitivity to fuel
volatility (where supercharging is not employed).
Note: This is mainly due to the type of induction
system used with this type of carburettor.
Sensitivity to aircraft attitude .
Sensitivity to air density (necessity for monitoring
manual mixture controls with changes in air densities
and temperatures).
2. INJECTION-TYPE CARBURETTORS
Advantages
Disadvantages
Automatic fuel regulation (pre-selected mixture ratios
can be maintained under all operating conditions).
Complexity of rlcs ign.
Reduced throttle icing (fuel is sprayed downstream of
the tlu-ottle valve; thus, reduced temperatures due
to fuel evaporat ion are not imposed on the throttle
valve).
Costly overhaul.
Not affected by aircraft attitude.
Good fuel a tom isation .
Large number of working parts.
Icing hazards, although slightly reduced, arc still
present (particularly in unsupercharged engines).
Unequal fuel distribution and sensitivity to fuel
volatility (where supercharging is not employed).
Note: As in the case of float-type carburettors, this
is mainly due to the type of inrluction system userl
with this type of carburettor.
3. DIRECT FUEL INJECTION
Advantages
Disadvantages
M ore even fuel distribution, and less sensitive to fuel
volatility.
Reduced fire risk (only a small volu me of the
induction system con tains explosive mixture).
Complexity of design and manu fac ture (large number
of working parts, close tolerances in pump , complex
nozzle design ).
Nozzles generally sensitive to fuel cleanliness.
Reduced icing hazards. Note: throttle icing and
impact ice are still possible.
In som e system s manual mixture control monitoring
is necessary for changes in air densities a nd pressures.
Not affected by aircraft attitude.
Increased mass air flow (has a cleaner induction
system - space normally occupied by fuel vapour is
available for air).
Aviation Safety Digest 119 I 23
�
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1984
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�Contents
3
High-wing aircraft and stall/spin accidents
7 Va and aircraft weight
A response to inquiries concerning the statement in
Aviation Safety Digest 116 that Va decreases with
aircraft weight.
8
10
Incorrect glider launch
11
Keeping out unwelcome visitors
Mud-dauber wasps are active in nest building during
the warmer months of the year.
Hearing conservation
The Department of Aviation initiated a survey of noise
levels inside light aircraft . Results showed that the
Pitts S1 and agricul t ural and glider towing types pose
an immediate hearing risk if operated without ear
protectors.
13
Let George do it -
but watch him!
A DC-10 entered a f ull aerodynamic stall while climbing
through 27 500 feet. The crew had mistakenly placed
the autopi lot system in a vert ical speed mode rather
than an airspeed or Mach command mode.
14
Bird proofing parked aircraft
15
Operations from dirt airstrips
16
Use your P-charts
Accidents whic h are attributable to a pilot's failure to
use performance charts are an unfortunately persistent
feature of Australian General Aviation. The use of
P-charts is vital in preflight planning, since small
changes in operating cond itions can often significantly
red uce an aircraft's capabilities.
20
Aviation Safety Digest is prepared by the Bureau of Air Safety
Investigation in pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to
Australian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Australian civil aviation.
Out of trim leads to out of control
A Beech 36 experienced severe pitch oscillations after
takeoff and finally crashed o ut of control. The prime
cause of the accident was the pilot's failure to
complete preflight vital actions.
12
High-wing aircraft and stall/spin
accidents
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the tree list experiencing problems with distribution or wishing to notify a change of address should write to:
I
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 18390, Melbourne, Vic. 3001.
Aviation Safety Digest is also available on subscription from
the Australian Government Publishing Service. Enquiries and
notifications of change of address should be direc ted to:
Mail Order Sales,
Australian Government Publishing Service,
P.O. Box 84, Canberra, ACT 2601
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Reader contributions and correspondence on articles should
be addressed to:
The Director,
Bureau of Air Safety Investigation,
P.O. Box 367,
Canberra City, ACT 2601.
© Commonwealth of Australia 1983,
RM81/30216(1) Cat. No. 83 3758 2
Printed by Ambassador Press Ply. Ltd.
51 Good Street, Granville, N.S. W. 2142.
An ill wind
A careful assessment of wind velocity - that is, both
direction and speed - is essent ial before any landing
is attempted.
22
Door open in flight (reader contribution)
23
Aircraft tyre care
23
You were saying .. .?
23
In brief
Covers
The Snowy Mountains Hydro Electric Authori ty has been
operating the Britten-Norman Islander featured on the covers
for seven years. Since 1958, the Aircraft Branch of the
Authority has ferried personnel, stores and equipment
throughout the Snowy Mountains area. Bushfire spotting and
SAR operations have also been conducted.
Aircraft operated by the Authority have included the Beaver,
Aero Commander, Grand Commander, Piaggio, Comanche
and Porter. By the t ime this issue of the Digest is
distributed, the Islander should have been replaced by a GAF
Nomad N22B.
The Aircraft Branch is based at Polo Flat airstri p, near
Cooma.
(Photograph by Kevin Ginnane)
2 I Aviation Safety Digest 118
l
I
j
A viation Safe1J1 Digest 93 contained a n account of a n
acciden t in which a C essna 150 d ived near vertically
into the ground during m uste ring operations. A pilot
con t ribution in the same issue referred to two other
accid ents u nder sim ila r circumstances. All of the
accidents fo llowed a steep clim b from a low pass, with
the a ircraft apparen tly flicking into a dive off the top of
the clim b o r out of a wingover or si m ilar manoeuvre.
U p to the time th is article was written six more
accidents had occurred u nder similar circumsta nces. All
were fata l b u t on ly one occu rred du ring m ustering
operations. The others were, however , associated with
low fly ing. It seems significant that a ll of the aircraft
involved in the accidents were high-wing types. An
examination of the Bu reau of Air Safety Investigation's
computer records for a 10-year period revealed that
on ly high-wi ng types were involved in th is sort of
accident during that period .
(continued overleaf)
Aviation Safety Digest 118 I 3
�In one of these a ccidents, of which the accompanying
photographs show the final disastrous resu lt, the aircraft
h ad several times overflown a group of stockmen at a
water bore, at a height of about 50 feet. On what
turned o ut to be the final pass, the aircraft flew over the
bore at a low height, the engine power was heard to
increase a nd the aircraft started to climb . The nose rnse
sharply and the aircraft cl im bed steeply to almost 250
feet. The left wing then dropped and the aircraft d ived
vertically , spira lling to the left. It struck the ground
nose first , crushing the forward sections of the cabin
and wings and , after impact, remained poised in a
vertical attitude. The r eason for the flight is not known,
although it does seem as though the decision to overfly
the stockmen was taken on the spur of the moment .
Two aspects of this type of accident are significant:
only h igh-wing a ircraft have been involved, and the
impact with the ground has often been near-vertical.
These factors suggest the following explanation for such
accidents:
W ith a high-winged aircraft a pilot flying close to the ground
often has to 'lift' a wing with aileron to maintain or regain
visual contact with a ground Jea-lure. During either steep
turns with a high g-loading or wingovers, this 'lifting' of the
wing will involve a height gain and speed loss which could
place the aircraft in a potential stall/spin situation. The
danger inherent in this will be exacerbated if the pilot is still
concentrating on looking for ground features.
In analysin g an acciden t of this type, a n experie nced
m ustering pilot postulated the following sequence of
events:
A steep climbing turn was probably commenced with a
n ose-up attitude of about 15 degrees. I believe that instead
of allowing the nose to drop away, the pilot, who almost
certainly would have been looking back at the ground ,
con tinued to hold on back elevator until , at about 40 knots
and with a steep an gle of ba nk, the aircraft stalled. The
upper or outside wing would have stalled first and the
a ircraft would have flicked out of the turn into a
90-degree bank in the opposite direction. The nose would
then have fallen away to the vertical and, in this attitude,
the aircraft would h ave struck the ground.
T he crucia l factor here is that, in the first instance,
the a ircraft stalled . All stalls do not culminate in spin s,
but an aircraft must be stalled before it will spin. All
pilots must be aware o f the facto rs associated with
sta lling, so th e discussion below add resses the most
pertinent of these. Note that althou gh this article had its
origin in relation to accident s involving hi gh-w ing
a ircraft, the discussion of the factors inherent in stalling
and spinning a re valid for all aircraft types .
The aerofoil
Most of today's General Aviation a ircraft have
aerod ynamically efficient, hi gh-speed w in g sections wi th
nearly identical curvature on both upper and lower
surfaces. T his m eans that a zero angle of attack may
give zero lift. A ircraft with such a wing must be flown
at a positive angle of a ttack at a ll times to maintain
positive lift. For an y aerofoil the lift produced increases
with the a ngle of attack until the crit ical point is
reach ed , at which stage separation of air from the u pper
surface results in the win g stalling and a drastic
red uction in lift.
4 I Avia tion Safety Digest 718
At high cruising speeds, the positive angle of attack
required is quite s mall , but as airspeed is decreased , the
angle of attack necessary to provide lift increases
rapidly towards the critical po int.
Angle of bank and load factor
Stall speed, of course, is always raised when the a ircraft
wing is banked, since ban king increases the to tal load
factor of the aeroplane. (The load factor is the resu lt of
gravity forces pl us any centrifugal forces acting on the
a ircraft.) In sha llow turns of 30 degrees or less, the
add itional load factor imposed by the centrifugal fo rce
of the turn is almos t negli gi ble - only 0.154 at a
30-degree ban k a ngle . Any steeper bank raises the load
factor from centrifugal forces very shar ply. At 45
degrees the to tal load fac tor is 1. 4 14 and at 60 degrees
it is 2.0. This is illustrated in Figure 1.
T he load factor for any aircraft maintaining level
flight with a constant angle of bank is the same,
regardless of airspeed; for ex ampl e, the load factor in a
60-degree bank is always 2g regardless of a irspeed or
a ircraft type . You can calculate the stall.speed for any
aeroplane at any degree of bank if you understand that
normal s talling speed increases always in p roportion to
the squ are roo t of the load facto r. I n the 60-degree
bank angle cited above, the load factor is 2g, the square
root is 1. 4 15: if the aircraft has a nor mal stallin g speed
of 48 knots, it will stall a t 68 kno ts in a 60-degree bank .
In simpler terms , it rriay help to remember t hat a
60-degree bank will raise your stalling speed by nearly
50 per cent. Careful pilots carry a safe-over-stall margin
of a irspeed whenever executing turns, especially near
the ground. A table of typical sta lling speeds for a
sing le-engine GA aircraft is a l Fig ure 2 . Note the e ffect
of flap.
1
1.00
1.06
1.31
2.00
5.76
ANGLE OF ATTACK 10°
Angle of attack
Some of the more common m isconceptions about stalls
involve a confusion of the two terms, pitch attitude and
angle of attack. Pitch attitude is the angle formed by
the longitudinal axis of the aircraft with respect to the
horizon - when the nose of the aeropla ne points at the
horizon , the pitch attitude is always zero, regardless of
which direction the a ircra ft is moving, whether it is
clim bing or descending, etc. The angle of attack is 'the
acute an gle between the chord or an airfo i.I (essentially
the wing) and the relative airflow' . T his has noth ing
necessarily to do with the horizon. I t is possible, by the
application o f back pressure on the elevator , to produce
a hi gh angle of attack in a n aircraft in any a ttitude. An
aircraft may be sta lled a t any a tti tude if the critical
angle of a ttack is exceeded. See Figure 3.
(co11ti11ued 011 page 6)
ANGLE OF ATTACK 10°
~LEOF:TACK10"
~
·~
FLIGHT PATH
,.
2
J.
Figure 1. Size of arrows and figures beneath show how
wing load factor increases with bank angle.
i
PowerOff
Figure 2. The angle of attack is the angle between the wing
chord and the flight path (not the ground).
STALLING SPEEDS
Gross Weight
16001bs
Figure 3. Stall speed varies with flaps and bank angle.
{Speeds are representative only.)
ANGLE OF BANK
---
~o /so
oo
~
CONDITION
..........
48
50
55
68
20° ~
43
44
49
61
42
43
47
58
Flaps
UP
Flaps
Flaps
3
KTS-IAS
40°
,
20°
0
Aviation Safety Digest 118 I 5
�Pilot quiz
Comment
L isted below are six qu est ions r elated to stallin g which
all pilo ts should be able to an swer . R ead the questions
and determine yo ur response before checki ng the
answers a t th e end o f the a rticle.
Man y ai r safety invest igation reports include the
statement that a n accide nt occur red because the pilot
'failed lo m a intain a irspeed and the a ircra ft sta ll ed ' .
Pilots need to u nderst and the fa cto rs affect ing stalling
speed and to conduct regu la r stall ing p ract ice in a range
o f aircraft configurations . Only b y doing this arc they
likely to be ab le instinctivel y lo a vo id or compen sate fo r
situa tions, cond iti ons a nd attitudes which may lead to a
stall - even u nder the stress and duress o f the
add itional problems that we all in variably encoun ter on
some occasion in fligh t. This r eq u iremen t is particularly
importan t fo r p ilots or high-wing aircraft in volved in
lo w-level opera tio ns. T ra in ing is extremely impo rtant,
as low-level m anoeuvring even by a piJot trained for the
task conta ins an elem en t o f r isk, but fo r pilots with little
experie nce at lo w fly ing it o ften ends tragicall y.
For a concl ud ing com m e nt , the expe rienced
mustering pilot mentioned earl ier o ffe rs so me sou nd
advice to those invo lved in low-level oper a tions.
Turning quickly is frequent ly necessary in mustering but I
would stress that the safest way to Oy under these exacting
conditions is never to pull unnecessary g fo1·ces. Flying an
aircraft fi tted wi th a g meter I have fou nc:J. that it is not
necessary l o pull more than 2g in normal mustering
operations. It is a very steep dive and recovery indeed that
will pull 3g. Pilots engaged in mustering operations need to
be very carefu l in applying back elevator. Many will argue
about other factors, but it is the heavy-handed use of backstick which produ ces high g forces and the situation which
leads to an ' outside nick' in a steep cl imbing turn .
Unfo rtunately there are no pilots who have experienced
this particularly deadly manoeuvre under 300 fee t and
li ved to tell about it •
Questions
1: Must a n aircraft be fl ying at a relati vely low
2:
3:
4:
5:
6:
airspeed in order to stall '
H ow does weight and balance affect stalling speed ?
Can turbulence affect sta ll tendencies?
Unco-ordinated fli ght does no t affect the stalling
speed of an aircraft - true or false?
Can the buildup of foreign matter (e .g . mud or ice)
o n a wing a ffect stalling speed?
Does the indicated airspeed at which an aircraft
stalls vary with altitude?
Maintaining currency
All pilo ts practise recovery from stalls when training fo r
a private pilot ' s licence , but how many ever contin ue
this practice on their ow n? W hen did you last spend
ha lf a n ho ur a t it? The operations tha t a pilo t conducts
routinely in the course of fl y in g hi s a ircraft increase his
skill and awaren ess, but those which he m erely keeps in
the back of h is mind , like stall r ecovery, grow rusty
with time . The argument is sometimes made that s in ce
m ost fatal stall acciden ts occur n ear the ground , the re is
no point in m a inta ining skill at recovery from a sta ll
with minimum loss of altitude. The fact is tha t the
d iffer en ce of a few feet in th e altitu de lost in a sta ll
recovery can m ake the differ ence between a safe
landin g a nd a disaster. It is hard to think o f a bette1·
ar gument for practice .
Most p assengers ar e n ot over-en thusiastic abou t
sitting th rough s tall recove ry p ractice, b ut it is a good
idea fo r a pilot to get the fee ling o f an a ircra ft in stalled
condition s with a full load o n board. Properly secu red
ballast in th e rear o f the ca bin ca n sim ulate full
occupancy . The difference in the aircraft ' s behavio ur at
m inimum slow speed operat io ns m ay be s urpr isin g,
especia ll y wi th regard to sta ll sp eed a nd loss of a ltitude .
Ensure that the re a re no loose o bjects o f an y kind in the
cabin before yo u take off inten di ng to p ract ise sta lls, as
a sh a rp sta ll m ay turn su ch objects in to serious sa fe!y
hazards: they could inj ure people , da m age the cockpit ,
become j amm ed in flight con trols, etc.
The stall warning horn
Some p ilots develop the hab it of tu rning off the sta ll
warning horn o r other warning devices when practising
stalls, operating a t slow sp eeds for p rotracted periods,
o r even when la nding, because they find it d istracting .
This is a da ngerou s hab it . M ost experienced p ilots can
tell - most o f th e time - by the ' feel' of the contro ls if
their a ircraft is on the verge o f s talli n g , b ut if they are
preoccu pi ed thi s may nq t be the case. In those
circu mstances the war n in g ho rn ca n be a li fesaver . It
shou ld never be tu rn ed off.
6 I Aviation Safety Digest 118
Va and aircraft weight
An article in Aviation Safety Diges t 116 discussed airspeed limitations for flight in turbu lence.
Among other things, that article briefly discussed the relationship between an aircraft's speed and
weight. The Digest has received a considerable number of inquiries concerning the statement in the
article that Va decreases with aircraft weight. The following more detailed account of the Va/aircraft
weight relations hip is printed in response to those queries.
Positive stall at Va
and reduced weight
.
I
A1 + I A
D
/ :
a:
~
~
g
~
>
::>
LU
0
z
<t
~
I
Positive stall /
(wing-flaps / ,
I
I
retracted/
i
Positive limit
n load factor
1
---*----+------------
1·0
+t /
i
I
Ql'i::---------~-----------~ ~~,,,--=-~--..__
-
l
___
Negative stall (wing - flaps retracted)
SPEED OF FLIGHT
E
(E.A.S.)
i
--1._ _~_
GQ7-~---<---~~~-----E~~~--l~~~~~~~~_.!..._~__L
i--- - -- - - -- -- - Ve -
---<.~I
.
1
~~~~~~~~~~~~~~vo ----l
MANOEUVRING ENVELOPE
Answers to quiz
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By d efin ition the Design M anoeu vre Speed (Va) is the
a ircraft speed at wh ich abrupt or full control deflections
will not overst ress the aircraft at the D esign M axim um
W e igh t. T h is m eans that the w ing m ust stall a t or
below the D esi gn Limi t L oad Factor (n 1) at Va. T his is
shown as point A on the m anoeu vre en velope (see
d iagram ). H en ce at th e rnaxi mu m weight a t a irspeeds
less tha n Va the win g will stall befo re limit load is
reached a nd therefo re the ai rcraft will not be
overstressed eve n with coarse control inp u ts.
H owever, at lo wer weigh ts a nd the sam e airspeed,
coarse co n trol d eflectio ns will n ot result in the wing
stallin g until load factor s g reater tha n the design lim it
load factor ( n 1) are r eached . As the p r im ary wing
structur e is designed to su p port its max imum
a erod yna m ic lift a t Va it m ay not be overstressed und er
these conditions . However , certain other components for exam ple, engi ne m ou nts - wo uld be overst re ssed
because the weight they su pport is constan t.
T o avoid the possib ility o f overstressing some
compon en ts of the a ircraft at the lower aircraft weigh ts ,
m a n ufacturers therefore recommend reduced
m a noeu vring speeds at these weights . A stall line has
been sketched at a r ed uced weight on the manoeuvre
en velope an d , a s can be seen, the win g will develop
enough lift to exceed n 1 at Va. In this case the
r ecomm ended m an oeu vre speed would be a t point At.
Some elaboration is needed on the comment m ade
above that the primary wi ng str uctu r e may not be
ove rstressed at Va even at reduced a ircraft weigh ts .
Th is is only true if the wing weight is consta nt, i .e . if
fuel tanks , baggage, etc. are in the fuselage. Under
positive load fac tors a ny m ass in the wings provides an
in ertia load in the down d irection. T hese loads a re in
the opposite direction to the lift fo rces a nd therefor e
reduce the resulta nt load that the wing structu re must
carry. Without going in to a lot of deta il regard ing the
loca tion of fue l tanks it can be seen that, as the win g
weight decreases, the iner tia relief p rovided also
decr eases and hen ce at the same aerodyn am ic lift the
net load the wing structu re m ust carry is increased.
T hus if the ai rcraft weight reduction is d ue to the
usage of fuel fro m the wing tanks, the net load on the
wing may increase a s the a ircraft weigh t is reduced.
T he var iation will d epe nd o n the precise location of the
fue l tank in the win g .
T hese factors plus a n u mber of others are con sidered
by the designer in determi ni ng a ircraft limi tations,
which incl ude the manoeu vre speeds . The crucial fact
as far as pi lots arc concerned is that which was
highlighted in Digest 116; namely, as a ircraft weight
decreases, so too does Va •
A viation Safety Digest 118 I 7
�Out of trim leads to out of control
At some stage during the preflight, before start and
before takeoff checks, all aircraft checklists stipulate
that pilots must complete certain checks on the
aircraft's trim system. Just when these checks are
carried out varies slightly depending on the aircraft
type, but they invariably include two essential
elements:
• a full functional test of the trims, and
• positive confirmation that all trim controls are set
to the takeoff position.
As the pilot of a Beech 36 found out, these vital
actions are prescribed for very good reasons, and if
they are not completed thoroughly, the consequences
can be disastrous.
The accident
The Bona nza was to convey the pilot, four passengers
and their luggage to a seminar. Some difficulty was
experienced in starting t he en gine but this was
Analysis
Post-accident investigation revealed that the Bonanza's
elevator trim was set to the full nose-up position. The
system was fully serviceable. As the pilot had not been
able to alter the setting of the elevator trim in flight, it
is apparent that she must have taken off with full noseup trim set.
Further investigation brought to light the fact that the
pilot who had flo wn the aircraft on its previous sortie
usually landed with fu ll nose-up trim applied and was
not in the habit of re-setting the trim to the takeoff
position after landing. Indeed, both he and another
pilot who flew the aircraft frequently had on different
occasions taken off with excessive nose-up trim set, but
both had been able to maintain control by rapid
application of nose-down trim.
In this case the pilot was unfamiliar with the
Bonanza: she had only 21 hours on type and had not
flown it for six months. Subsequent discussions with her
made it clear that, because of her lack of recency on the
Bonanza, wh en she tried to apply nose-down trim she
in fact attempted to rotate the trim wheel in the wrong
- that is, the nose-up - direction. However, full noseup trim was already set; hence her inability to move the
trim wheel.
Beech Aircraft Corporation completed a computer
profile on the Bonanza's expected takeoff performance
and an assessment of control column forces to be
expected when full nose-up pitch trim is selected. They
found that 55 p ounds force were required at 70 knots
and 97 pow1ds force at 90 knots, with the force
required increasing rapidly with increased airspeed.
Rudimentary tests sh owed that an adult male
experiences con siderable difficulty in holding 55 pounds
force for any length of time, let alone a rapidly
increasing force . The pilot in this case simply was not
p hysically capable o f controUing the aircraft Jong
enough , particularly when she was unable to relieve the
trim forces. While reducing engine power would have
alleviated some of the forces, it seems probable that
when the pilot removed one hand from the control
column to operate the throttle, the extra load her other
arm then had to cope with initially gave her the
erroneous impression that reducing power was
exacerbating her problem; therefore, she reapplied
power.
Adding to the pilot's difficulties was th.e aircraft's
loading. It was calculated that the aircraft took off 38.3
kilograms over the allowable maximum takeoff weight
(MTOW), and that its centre of gravity was 6.35
millimetres aft of the rear limit allowable a t MTOW.
W h en combined with the out-of-trim takeoff, these
facto rs became significant. None of the lu ggage was tied
down or restrained.
overcome and the aircraft even tually taxied for an
engine run-up. The pilot then performed the before
takeoff checks without using a written checklist.
The aircraft commenced its takeoff roll and became
airborne at about 60 knots. The nose rose higher than
normal and the stall warning horn started blowing.
Pushing the nose down against considerable 'backstick '
pressure, the pilot tried to trim out the forces but was
unable to move the trim wheel. The aircraft began to
experience pitch oscillations and, as the airspeed
increased, the force on the control column became
heavier, which in turn made the pitch oscillations more
pronounced. Power was reduced, but this appeared to
make the back pressure on the controls worse, so it was
reintroduced. The pilot asked the passenger in th e
right-hand pilot's seat (the holder of a restricted private
licence) to retract the undercarriage and to trim the
aircraft's nose down , but the passenger was unfam iliar
with the aircraft and was unable to assist.
Realising that the situation was becomi ng desperate
the pilot grabbed the m icrophone and t ried to transmit
a distress call. While the transmission was unint elligible
the Aircraft Rescue and Fire Fighting Unit nevertheless
turned out when they h eard it. Seconds later the
Aerodrome Controller activated the crash alarm.
By now the pilot could no longer hold the control
forces a nd m ade a desperate turn back towards the
airfield with the aircr aft virtually out of control. To
observers the turn looked like a stall turn. T he aircraft's
nose was well below the horizon at the completion of
the manoeuvre. Engine power was again reduced by
the pilot but as once more this made pitch control even
more difficult it was reapplied. This was the pilot's final
attempt to try to do som ething positive to r etr ieve the
situation.
Out of control, the aircraft struck trees on the bank
of a creek and was engulfed by fire as the right wi ng
separated. The aircraft yawed through 180 degrees
before hitting the water tail first. The Aircraft R escue
and Fire Fighting Unit, who were mobile before the
Bonanza actually crashed, arrived at the scene only 3
minutes later. They rescued the four passengers from
the creek and cut the pilot free from the wreckage of
the cockpit. Remarkably, all survived, albeit with
serious injuries.
, . -r:f(
1
~
I
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..
I
I,
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I
Comment
The prime cause of this accident was the pilot's fail me
to positively check the trims, for both function and
correct setting, prior to takeoff. The possibility was
raised that the letter 'U' (for UP) on the elevator trim
position indicator may have been mistaken by the pilot
for a zero if the lubber line happened to be
superimposed over the 'U' (see photograph). Even if
this were the case, it was a mistake which would have
been realised had a full functional check of the trims
been completed. A written checklist may have helped in
this regard.
The habit of the other pilot in leaving the elevator
trims set in the full nose-up position was poor
airmanship. This practice had in fact been discussed
with him on occasions but nothing had been resolved;
as a consequence, the practice ultimately contributed to
a major accident. While light aircraft checklists vary in
content and quality, it remains good airmanship to
'clean up' the cockpit after flight b y switching off all
equipment and resetting controls - including the
trims.
A final word on rescue services is warranted. This
accident proved yet again the value of letting someone
know about your emergency. While the pilot's radio
transmission may have been unintelligible, the tone it
obviously conveyed was sufficient to 'scramble' the
airport rescue services, and as a result those services
arrived at the crash site within minutes, thereby gr eatly
increasing the accident victims' chances of survival •
Aviation Safety Digest 118 I 9
�Incorrect glider launch
At a height of about 300 feet during a winch launch , an
ICA IS-29D glider was observed to be experiencing
instability in pit.~h, yaw and roll. The winch operator,
considering that the pilot was in difficulty, closed the
winch throttle and applied the cable brake.
The cable was seen to release and fall away to the
airstrip. The glider stalled and entered a rapid spin to
the right. It briefly recovered from the spin at a very
low height bu t then entered a fur ther spin to the left.
Ground impact was in a steep nose-down attitude,
72 metres north of the airstrip and about 430 metres
from the point where takeoff had commen ced. The
glider was destroyed and the pilot killed.
Background
The pilot had travelled to the scene of the accident to
participate in a gliding competition. He brought the
glider with him.
This glider was constructed with two towing hook
attachment points: a forward point for aero-tow
launching and a rear point for winch or auto-tow
launches. The glider's flight manual states that if winch
or auto-tow launches are made utilising the forward tow
point, and full elevator deflection is applied during
la unch , then pitching instability (porpoising) m ay
occur. To counter this a reduction of airspeed or
elevator deflection is recommended. At its home base
this p art icular glider was normally operated by an
aero-tow la unch , and only the forward h ook was fitted.
A cover plate h ad been fitted over the rear attachment
point.
T he pilot was fa milia r with winch and auto-tow
procedures but had not u sed either for several years: all
his recent flying had been associated with aero-tow
procedures. To refresh himself on winch laun ch
procedures he carried out a dual flight with an
instructor in a t wo-seat glider shortly after his a rrival at
the competition a irstrip. On the same day another pilot
made two flights in the IS-29D. Auto-tow la unches
using the forward hook were made for these two flights
Keeping out unwelcome visitors
and minor porpoising was expe rienced.
The following day the visiting pi lot made a brief
flight in the IS-29D. A winch launch was carried out
and he experienced p orpoising during the launch. He
returned for landing via a low right-ha nd circuit
pattern, instead of the nor mal left-hand pattern, and
during the landing roll experienced directional co ntrol
difficulties. A collision with a p ar ked vehicle was
narrowly avoided. Shortly afte rwards the p ilot
undertook a second flight. Once m ore porpoising
occurred during the w inch launch and o n the return to
land the pilot forgot to lower the landing gear, even
though the gear warning ho rn sounded, un til reminded
of hi s oversight by a radio call from an obser ver o n the
ground.
After this flight the pilot advised his companions that
he wa s unhappy with his p erformance and wou ld not
fl y solo again that day . He expressed the intention of
arra!lging a check flight with an instruct:pr.
Another pilot then flew the IS-29D and experienced
porpoising during the winch launch. H e considered it
was caused by excessive speed on launch. He also
thought that a takeoff without flaps might reduce the
porp01smg.
At this stage the p ilot who was subsequently involved
in the accident decided that, contrary to h is previou s
decision not to fly solo again that day, he wanted to
undertake a third fligh t. The other pilot agreed, and
passed on his assessment of the cause of the porpoising.
The glider was prepared for a la unch in to a headwind of a bout 10 knots. After boarding the glider the
pilot spoke by radio to the winch operator a nd asked
that the la unch be made at reduced p ower . A member
of the local gliding club who heard this exchange then
intervened to advise that the standard procedure was to
call 'slower, slower' on th e radio if the launch was too
fast and ' faster, faster' if it was not fast enough. The
pilot acknowledged th is advice.
The ground roll and in itial climb appeared n ormal to
ground observers. As requested by the p ilot, winch
(co ntinued on page 11)
I
J
Frequent publicity is given to the attempts - many
of which are successful - of aviators of the feathered
variety to set up house in the vehicles of those who
wish to e mulate the birds. In other words, we all
know that b irds build nests in aircraft. On occasions
these nests have posed serious safety threats by
jamming flight or engine controls or by providing
flammable material where none should be. The
propensity of som e insects to build homes in pitot
heads is a lso well known : hence the pitot cover.
A reader recen tly discovered another type of
unwelcome construction activity going on in his
ai1·craft. It is probably not as well known as the
oth ers but it could pose just as great a threat to flight
safety .
The pilot had not flown his a ircraft for one month
and during h is daily servicing found that there was
ver y little movement in the ailerons. He traced the
problem to the port wi ngtip where he found that
mud-dauber wasps had built a nest on the balance
arm (see the p hotographs). The nest was a very solid
construction and required con siderable effort to
remove it. The pilot believed he could not have
operated the a ilerons simply by using the con trol
column .
Research by the Aviation Safety D igest staff came up
with th e following information. A number of species
of wasps belong in g to the family Sphecidae are likely
to be involved in inciden ts of this type. All of the
species are active in nest building during the warmer
periods of the year.
The application of insecticides to discourage mud
wasps is un li kely to be successful, for the only
sui table chemicals would degrade, and lose their
effectiveness, if exposed to the elements. The best
dete rrence is provided by the regular use of physical
Incorrect glider launch
(co111i11ued)
power was applied slowly and then reduced when the
glider was airborne. After reaching a height of
approximately 300 feet above the ground, the pilot
called 'slower, slower' over the radio and the winch
operator reduced power even further. The disastrous
sequence of even ts detailed at the start of this article
then eventuated.
Analysis
.Glider being towed by belly hook position. Forward hook is circled.
10 I Aviation Safety Digest 118
barriers such as netting, covers, caps and plugs.
Good housekeeping around hangars and parking
areas is also important: not allowing taps to drip, for
example, will deny the mud-daubers one part of
their building material.
There is more to keeping out unwelcome visitors
than pretending you are not at home when your
relatives arrive unexpectedly. For pilots a nd aircraft
mechanics, the little bit of extra effort involved in
adopting an active preventive maintenance program
against the kind of hazard discussed in this article
can be repaid many times over in terms of flight
safety •
The main factor which emerged during the
investigation into this fatal accident was that the glider
was configured for aero-tow la unching with the towhook on the for ward attachment point, and the hook
was not repos it ion ed to the rear attachment point for
the winch operations. Because they d id not check the
flight m anual, the pilot involved and his companions
were not aware of th is requirement. They were also not
aware that the flight m anual stated that porpoising
could occur if w inch launches were made using the
forward attach ment point.
Thus, when porpoising did occur, attempts were
made to overcome it by experimenting with flap
settings, winch power and airspeed. E ventu ally, the
experiments went too far and the glider stalled and
spun, from which dire situation the pilot was unable to
recover. The fact that the glider initially spun to the
right, recovered briefly and then spun to the left,
suggests that the pilot's spin recovery technique may
have been faulty.
I t seems likely that a second factor was the
psychological condition of the pilot. For reasons which
remained undetermined, he had experienced difficulties
during his two earlier flights : he almost collided with a
vehicle on his first sortie and almost landed wheels-up
on the second. P ossibly he had been unsettled by the
porpoising.
In view of these occurrences, his init ial decision not
to fly solo again that day was prudent. Regrettably , he
subsequently changed that decision, wit h disastrous
consequences •
Aviation Safety Digest 778 I 11
�Hearing conservation
The noise levels associated with aircraft operations have been a cause of concern for many years.
Any hearing loss which may result from an individual's exposure to excessive noise is undesirable
in itself; while in relation specifically to flying, a satisfactory level of hearing is obviously essenti~I
for a pilot to operate safely. An intensive effort has been made by manufacturers of Regular Public
Transport (RPT) aircraft to reduce noise inside those aircraft. However, the same effort has not been
applied to light aircraft because of technical and economic constraints.
The Standards Associa1ion of Australia (SAA) has
recommended a program wh ich is designed to protect
people who are occupationally exposed to noise . As far
as pilots are concerned, an important element of this
program is the formulation of an acceptable Daily
Noise Dose (DND). An individual will sustain a DND
to the value of 1.0 if he is exposed to a noise level of 90
decibels (dB) for eight hours. A DND of 1.0 is
considered to be acceptable. Pilots are, of course,
subjected to noises other than those from aircraft during
the day, all of which add to their DND.
A DND of 1.0 is predicted to cause 46 per cent of
the population ' significant hearing loss' by the age of 65
years after forty-five years of five days a week in the
workforce. Noise is the decisive factor in determining
this degree of impairment in the majority of cases .
'Significant hearing loss ' is identified as the point at
which speech comprehension in a quiet environmen t is
impaired and is defined as 25 dB Average Hearing
Loss. One hundred and fifteen decibels is generally
accepted as the maximum allowable noise level for any
duration of exposure, however short.
It was against thi s background that the Department
of Aviation initia ted a survey to provide data and to
establish what hearing or operational problems may
a rise as a consequence of noise levels inside ligh t
a ircraft. This survey, conducted by the Department's
Advanced P lanning and Technology Branch at the
request of the Aviation Medicine Branch , was designed
to cover the following classes of aircraft and operations
applicable to the Australian environment:
• General Aviation a ircraft
• aircraft types involved in lengthy flights
• agricultural aircrafl
• hel icopters
• Departmental a ircraft
Measurements were taken next to the pilot's ear and
at selected passenger positions. The measurements were
taken in straight and level flight during climbing steps
to the normal cruise altitude, and repeated on the
descent leg. Noise levels during takeoffs and landings
were also recorded. Thirty different aircraft types were
used to produce the data.
The survey
As was mentioned above, an individual who is exposed
to 90 dB for eight hours will sustain the acceptable
upper limit DND of 1.0. In general, most of the
aircraft tested (single engine, light twins and
helicopters) produced levels of 90 dB, thu s allowing an
occupant to sustain a full eight-hour day exposu re
throughout a working life span with acceptable hearing
loss. This situation is further eased by the restriction on
pilot's flying time to 900 hours per year, an average of
2 Y2 hours per day.
12 I Aviation Safety Digest 118
It was found that the noise produced by multiengine, propeller-driven a ircraft can be substantially
reduced through engine speed and propeller
synchronisation. This can contribute significantly to the
conservation of hearin g.
There were some aircraft types or operations which
exceeded the acceptable noise levels.
The Pitts Sl aircraft tested poses a very rea l risk of
hearing damage since at takcoff with fu ll engine power
appl ied it registered 114.25 dB. This is very close to the
level commonly accepted ( 115 dB) as the threshold for
the onset of permanent damage. As high power settings
arc frequently used during aerobatic manoeuvres,
immediate damage is inevitable unless good ear
protectors are used .
Agricultural aircraft also were found to pose a risk.
During the spraying seasons pilots tend to work long
hours in aircraft which produce a cabin noise in excess
of 100 dB. This noise level results in a DND of 1.0
within about thirty minutes. A lthough agricultural
pilots wear helmets the sound attenuation produced is
unlikely to be ver y high . Pilots involved in agricultural
operations are likely to regularly exceed a DND of 1.0
with consequential hearin g loss.
Two aircraft, a Piper Super Cub and a n Auster
Aiglet, belonging to a gliding club and used for towi ng,
were tested and were also found to present a risk due to
the nature of the opcralion. An indi vidual pilot could
be exposed to the high noise levels ( 105 dB and 118 dB
for the respective types) for long periods in a busy day.
Saving factors arc short recovery periods between tows
and, usually, weekend activity only.
Summary
Of the aircraft tested, the Pitts Sl and the agricultural
and glider towing types pose an immediate hearing risk
if operated without ear protectors. The helicopters and
light-to-medium aeroplan es tested represent a noisy but
acceptable environment. They do , however, contribute
significantly to a pilo t 's total DND, bearing in mind
that pilots are exposed to other noise sources in addition
to their flying activities.
Operators requ iring information on the effectiveness
of various hearing protectors should consult the
National Acoustic Laboratories' booklet Attenuation of
H earing Protectors (3rd edition), which is available at
Au stralian Government Publishing Service Bookshops
in all capital cities. Specialist advice is also available
from the Department of Aviation, Aviation Merlicine
Branch, P .O. Box 367, Canberra City, A.C.T. 2601 •
Aircraft accident information
reports
SECOND QUARTER 1983
Prepared by the Bureau of Air Safety Investigation
The fol low ing information has been extracted from accident data files maintained by the Bureau of
Air Safety Investigat ion. The intent of publishing these reports is to make available information on
Australian aircraft accidents from wh ich the reader can gain an awareness of the circumstances and
conditions which led to the occurrence.
At the time o f publ icat ion many of the accidents are still under investigation and the information
con tained i n t hose repor ts must be considered as prel iminary in nature and poss ibly su bject to
amendment when the inves tigation is f inalised.
Readers should note that the information is provided to promote aviation safety - in no case is it
intended to imply blame or liability.
Note 1: All dates and times are local
Note 2: Injury classification abbreviations
C = Crew
P =Passengers
0 =Others
N =Nil
F =Fatal
S =Serious
M =Minor
e.g. C1S, P2M means 1 crew member rece ived serious inj ury and 2 passengers received minor
in ju ri es.
Note 3: The format of record numbers has been changed.
Preliminary report number 210013 from the previous Summary wi ll become final update
number 83 2100 1 in this issue.
PRELIM INARY REPORTS (The fo l lowing accidents are still under investigation)
Date
Time
Air craft type & registration
Location
Kind of flying
Departure point/Des tination
tn;uries
Record number
01 Apr
Piper 23-250 VH-DCO
Non-commercial-pleasure
Un known
Unknown
Brisbane, Qld.
Unknown/Unknown
8311022
During in ves tigatio n of a malfunctioning undercarriage-i ndicating lig ht, the aircrafl engineer discovered unreported damage to
the wing in lhe vicinily of the undercarriage leg.
01 Apr
Piper 32 R300 VH -EMD
Non-comm erc ial-pleas ure
C1N, P5N
1405
Lismore, NSW 4N
Schofields, NSW/Coolangalla, Old.
8321034
The pilot decided to divert lo a nearby aerodrome because the fuel gauges ind icated low. Shorlly after commenci ng the diversion
the eng ine failed. During the ensuing forced landing, the aircrafl slruck a fence post, overlurned, and slid inverted for 100 m.
01 Apr
Non-commercial-pleasure
Beech A36 VH·EUM
C1N, P5N
1500
Nundroo, SA
Ceduna, SA/Coorabie, SA
8341012
The pilot had previous ly discussed lhe strip wil h lhe slalion owner bu l had not ascertained its length. On overflying, the pilot
assessed its lenglh as 600 m, an d af ler c hecking the P-chart he calculaled thal 500 m was needed for a landing. The pi lot stated
thal he crossed th e lhres hold al 65-70 kt with fu ll flap selected. Ground marks indica ted tha t the aircrafl touched down 195 m past
lhe lhreshold and bounced lwice before overrunning lhe strip.
04 Apr
Piper 24 VH-KLM
Non-commercial - pleasure
C1N , P3N
1444
Parafield, SA
Paraf ield, SA/Parafield, SA
834 1011
During the circui t when the gear was selecled down it failed to ex lend. The gear circuit breakers were resel and the gear extended
normally. On lhe following c ircuit, the pilol was unable to establish lwo·way comm unications with the tower. Pre-landing checks
were completed a fler lurning back, however the pilot slill concenlraled on establishing conlac l with the tower. The aircraft
landed wi th the gear relracled.
05 Apr
Partenavia P68 B VH-PFQ
Charter-cargo
C2N
Karumba, Old.
Norman to n, Old./Karumba, Qld.
1750
831 1020
In an atlempt to avoid a flock of birds on short final, the pilol sideslipped lhe aircrafl. Both main whee ls struck lhe underrun
heavily, bending lhe le ft main gear, and the pilot carried oul a go·around. When lhe lefl main wheel contacted lhe runway on the
landing roll, the lyre def lated and lhe aircraft veered lo lhe lefl of the runway before coming to resl.
Aviation Safety Digest 778 I i
�PRELIMINARY REPORTS (The following accidents are still under investigation)
PRELIMINARY REPORTS (The fol low ing accidents are st i ll und er investigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
Date
Time
Aircraft type '& regis tra tion
Location
Kind of flying
Departure point/Des tination
Injuries
Record number
08 Apr
1328
Piper 30 VH-DRD
Coolangatta, Old.
Non-commercial-pleasure
Archerfield, Old./Coolangat ta, Old.
C1N
8311021
02 May
1832
Cessna 172 N V H-WXK
Narrogin, W A 10S
Non-commercial- b us iness
Kalanni ng, W A/Jandako t, W A
C1 F
8351015
After d iver ting from track because of deteriorating weather, the pilot was unabl e to locate a su itab le landin g area. Ena of day l ight
was approaching and afte r be i ng ad vised of th e neares t aerodrome w i th ru nway lightin g, t he p ilot diverted to tha t aerod rome. Th e
aircraft was later observed operatin g at low leve l in the vicinity of the aerodrome . It was I hen observed to c li mb sl igh tly from 50 ft
agl , turn abru pt ly to the right and im pact the ground in a nose down attitude.
The aircraft touched down normally, however during the landing roll the landing gear col lapsed. Examination has indicated that
the nosewheel retract mechanism failed to lock down at the completion of the extension cycle prio r to landi ng. The gear down
light micro swilch had activated.
08 Apr
0830
Piper 25 235/A5 VH-WSM
Foster, Vic. 12S
Commercial-aerial agriculture/baiting
· Foster, Vic. 12S/Foster, Vic. 12S
C1N
8331011
C1 M, P1M
Commerc ial -aerial mus tering
03 May
H ughes 269 C VH-C HN
8311027
River-Lea Sta tion/Riverside Station
Comet, Qld . 10NE
0920
Th e hel icop ter was weaving back and forth driving cat tle. Height was abo u t 30 ft an d airspeed abou t 25 kt. Th e pi lo t heard a loud
bang and believed the engine had fai led . An au to-rot ation w as carried ou t int o trees.
The strip used for takeoff was located in a large paddock in which a herd of Hereford steers was grazing. Because of a hump in
the strip , the full length was not visible from the takeoff end. As the aircraft passed the hump the pilot saw a s teer on the strip
ahead. He continued the lakeoff and at about lift-off the right wing struck the s teer. The pilot dumped the load and , after checking
the han dling of the aircraft, continued to a safe landing at Latrobe Valley.
09 Apr
1250
Beech 95 B55 VH-FDG
Maitland, NSW
Non-commercial-pleasure
Bankstown, NSW/Maitland, NSW
The pilot stated that he selected the landing gear down during the pre-landing checks and ob tained a down and locked indication.
However, the aircraft contacted the runway with the landing gear retracted.
09 Apr
1330
Beech 58 VH-EZB
Wyndham, WA
Charter- passenger
Kununurra, WA/Wyndham, WA
05 May
1714
C1N
8321036
•
C1 N, P5N
8351013
Romai nian IS-28B2 VH-CQD Non-commercial-pleas ure
Bathurst, NSW 7NW
Bath urst, NSW 7NW/Bathurst, NSW 7NW
Cessna 310 R VH-DVN
Canberra, ACT
Charter-passenger
Canberra, ACT/Cudal, NSW
Partenavia P68 B VH-IYL
Mary Kathleen, Old.
Charter-passenger
Longreach, Qld./Mary Kathleen , Qld.
C1 M, P3M, P1 N
8321037
Piper 28 R180 VH -CH I
Cessnock, NSW
Instructional-solo-su pervised
Sydney, NSW/Cessnock, NSW
C1M,.P5N
8311023
C 1F, P5F
Non-commercial - ple asu re
Piper 32 Rt300 VH-RH F
10 May
8391001
Port More sby, PNG/Madang, PNG
Port Moresby 30N
1231
The pilot intended to depart al 0800 hours, bu t due to equ ip ment u n serviceab ilities depart ure was de layed for 4 hours. Weath er
conditions on the p lanned trac k were reported to be adverse, and the p ilot advised that he wou ld track via an alternat ive rou te. No
furth er commun icat ions w ere received from lhe aircraft, and after a search las ting 6 days the wreckage was located in a b lind
valley at an alt i t ude o f 7900 ft.
C1N,01N
8321038
The pilot of the first aircraft was returning from a solo navex. He cancelled SARWATCH and repo rted enter ing the circuit on
downwind. The pilot of the second aircraft was carrying o ut solo circuit practice; h e heard the first pilot cance l SARWATCH bu t
not the downwind report. The first aircraft completed a normal circuit and as i t touc hed down the second aircraft, having
completed a glide approach, landed on top o f the first. They cont inued for 140 m be fore comi n g to rest.
21 Apr
0821
Mooney M20 J VH-MOP
Al ice Springs, NT
Non-commercial - pleasure
Alice Springs, NT/Leigh Creek, NT
C1 N , P1N
Non-com merc ial - p leasure
17 May
Cessna 182 P VH-T HC
8341015
Alice Springs, NT/Arapunyah, NT
Arapunya Sl n ., NT
1211
The land ing was made on a s hort st rip in gus ty c on di tion s. During the flare the airc raf t dropped heavi ly to th e ground an d
b ou nced. The second touc hd o w n was on the no sew h ee l, w h ich broke off. Th is led to a third touchdown during wh ich the
nos ewheel s trut dug i n and the ai rcraft s tood on its nose and righ t w ingl ip before se ttlin g b ack on the main wheels and nose.
C1N , P1N
8341013
When taxiing for takeoff, the aircraft nosewh eel ran over a taxiway centre light and the nosegear co llapsed.
22 Apr
1745
Piper 28 235 VH-EVL
American RVR , SA
Non-commercial - pleasure
American RVR, SA/American RVR , SA
C1 N
8341014
The pilot landed long on his property strip to avoid some sheep grazing on the ap proach end o f the stri p. During the landing ro ll
the starb oard main landing gear was torn off when i t struck a sheep. The starboard wingtip contac ted th e ground and the airc raft
s lewed to rest.
23 Apr
0927
B eech A36 VH-DAJ
Mt. William, Vic.
The pilot submitted a VFR flight
minu tes ater departure the pilot
also reported unsure of position
the clo ud -covered slopes o f Mt.
26 Apr
1740
Non-commercial-pleasure
Moorabbin, Vic./Sydney, NSW
C1 F, P4F
8331012
plan indicating that the first leg, Moorabbin/Mangalore, wo uld b e OCTA bel ow 5000 ft. Some 24
reported poor weather in the Kilmore Gap area and adv ised he w ould retu rn to Moorabbin. He
and requested a bearing. Attempts to assist the p il ot were unsuccessful and the ai rcra ft struck
Wil liam at about 2000 ft amst . Fire broke out on impact.
Cessna 182-R VH-PJV
Glenmore Sin., Old .
Non-c ommerci al- plea sure
Vanrook Station , Qld./Charlers Towers , Qld.
C1 N
831 1026
The pil o t made a precautionary landing on a road because of det eriora ting w eather. Duri ng the landing ro l l th e s tarboard wing was
dam aged when it struck a sapling o n the edg e o f the road .
ii I Aviation Safety Digest 118
C 1N,P1N
8321 039
C1 N
Non-com mere ial - pleasu re
Ce ssna 182 Q VH -MJZ
10 May
8311 0 28
Corella Park , Qld./H am ilto n Downs , Qld.
Hamilton Downs , Qld .
1830
The pi lot , who did no t ho ld an ins trument rating, arrived at h is d esti nat ion shortly after las t l ight. An ap proach was made to the
unlit slri p, but on to uchdow n the aircraft w as not al igned w i th th e s t rip direction. Correct ive acl ion including t he app l ication of
full power was unsuccess f ul, the nosegear coll apsed and the aircraft overt urned .
After touchdown the pilot applied light braking, but when he realised the aircraft would not s top before t he end o f the st rip he
applied heavy braking. The aircraft overran the strip and continued for a further 50 m before coming to rest.
18 Apr
1642
Wh ils t crui sing at 7500 ft , the pi lot became aw are of a fi re behind the throttl e quadran t. An immedia te d escent w as commenced
and attempts b y passengers to ex t ingu is h the fire were un succ essf ul. A ft er land ing the occ upants evacuated the aircraft and
were again unsuccessful in ex linguish ing the fire .
C 1N
Commerc ial-assoc. agricu ltu re/baili ng
10 May
Hughes 269 C VH-ARG
8311029
Coo lang atta, Qtd./Canun gra, Q ld.
Canung ra, Qld.
0630
The pi lo t landed the helicopter on an earthen dam wal l. Wh ile the main rotor w as wind ing down the land i ng sk id heels san k into
the wal l which had been soft ened by recen t ra in. The tai l rotor contacted the water of the d am resu lt ing in d amage to t he tail rotor,
tail rotor gearbo x and d rive shaft.
Moderate rain was falling at the time of the occ urren ce. The takeoff run was commenced b u t at a reported speed o f 80 kt the pilot
con sidered that the aircraft was not accelerating and he decided to abort the takeof f . The aircraft overran the runway, became
airborne for 120 m in order lo clear a ditch, then collided with the airport boundary fence before stopp ing o n a road.
14 Apr
1312
C1 N, P4N
835101 6
C1F
No n-commerci al - p leasu re
Cessna 150 G VH-RZS
08 May
8321 040
" Cu rragund i " Slrip/"Tooraween ah" Strip
Du nedoo, NSW 4E
0730
After becom ing ai rborne the aircraft struck two trees si tuated 155 m beyond the d ep arlure end of the strip . Th e aircraft impacted
the gro und i n a no se down att itu de 70 m pas t the trees.
C 1N , P1N
8321035
Ju s t after takeoff the engine cowl on the tug aircraft opened. At 100 ft agl the tug pi lot signalled the g li der pilot to release the tow.
The tug pilot reduced airspeed and landed the tug without further incident. The glider was turned to the right for a landing in an
adjacent paddock. The glider touched down heavily, short of the paddock boundary, bounced and st ruck the fence w i th t he left
wing. The glider came to a stop after a ground loop.
11 Apr
1235
Charter - passeng er
Geraldton, WA/Perth , W A
Non -commerc ial - pleasure
07 May
Cessna 210 L VH-BEV
Tum ut, NSW/Tum u t, NSW
Tumut, NSW
1500
A ircraft was landed w ith t he undercarriage re trac ted .
Attempts to lower the undercarriage by both the normal and emergency systems were unsuccessful. The undercarriage was
observed to be partially down and could not be raised. On landing the undercarriage collapsed .
10 Apr
0956
Beec h 95 C55 VH-FDT
Beermullah, W A
•
•
C 1N , P2 N
Com mercial - power/pipe l i ne patrol
Hiller UH12-E VH-AGL
17 May
8321 041
Hoxton Park, NSW/Ho x ton Park, NSW
Sydn ey, NSW 11SW
1456
Whilst on cruise al 1000 f t agl , the airc raft experienced a sudden loss of height. T he pi lot carr ied ou t an auto rotat ive landi ng on
river mud f lats. Duri ng th e landing th e tai l rotor s truck the water.
C1N , P6N
Non-co m merc ial- co rporate/exec ut ive
18 May
Partenavia P68-C VH-AJX
8351 017
Perth, WA/Blackcat Mine, W A
Mt. Magnet , WA 8NW
1110
The pilo t es tablished the aircraft on fi nal w i th fu ll f lap at 90 kt. Jus t before commenc ing the lan ding flare the p ilot observed the
airspeed drop to 70 k l and a hi gh si nk rate deve loped . The m ain wheels s truck a windrow be fore the s trip thres hold and the rig ht
main gear was torn o ff. The aircraft cont inued down the s trip and the left main gear col lapsed before the ai rcraf t came to a halt.
C1F
Charter - carg o
Mitsu M U2B-60 VH -MLU
23 May
8321042
Sydney, NSW/M el bou rne, Vic .
0459
Barg o, NSW 2E
The aircraft was c leared·via a Standard Instrument Departu re w ith an unrestr,icted climb to F L220. The ai rcraft c limbed on trac k at
an average rate o f 1300 ft /min u nt il F L 130. The rate-of-c limb then reduced to 350 ft/min u nt il F L 140, when the rate-of -climb
increased to 1800 f t/m in. At F L 160 the aircraft entered a near vert ical descent and radar conlact was lost one m i nute later at 3100
ft. The aircraft im pacted the gro u nd in a near-vert ical att itude.
A viation Safety Digest 118 I iii
�PRELIMINARY REPORTS (The fo ll ow in g accidents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
26 May
1121
De Hav C2 VH-IDU
Gembrook, Vic. 5E
Commercial-aerial agriculture/baiting
Gembrook, Vic./Gembrook, Vic.
PRELIMINARY REPORTS (The fo llowi ng acc idents are stil l under invest igat ion)
Injuries
Record number
C1N
8331014
During spreading operations, the engine suddenly lost power due to mechanical failure. The pilot carried o ut a successfu l forced
landing up a steep slope, the only clear area wit hin range. The aircraft came to res t on the slope then began to slide backwa rds,
wit h wheels locked, on the wet grass surface. The pilot released one brake and turned the ai rcraft across the slope but it
continu ed to slide until it struck a ridge , and the left main gear was torn off.
02 Jun
1607
Bell 206 B VH-AJI
Mt. Perisher, NSW
Commercial- construction (rotorcraft)
Perisher Valley, NSW/Perisher Valley, NSW
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
12 Jun
0715
Cessna P206 D
M t. Isa, Old.
Non -commercial-pleasure
Mt. Isa, Old./Sweers Islan d, Old.
C1M, P1M
83 11036
V H-DPU
The pilo t was unable to start the engine wi l h lhe starter. He set the park brake, exp lained to his passenger the' foo l brake
operat ion, and briefed her to slightly open the throttle if the engine looked like s topping after lie had i t s tart ed by hand-swinging
the propelle r. As the engine s tarted th e ai rcraf t moved forward . The passenger inadvertently fully opened the throttle, the airc raft
col lided wit h a fence and hangar door before com ing to rest em bedded in the side of the hangar.
C1M
8321044
12 Jun
1600
Ex permtl Aero VH-FMK
Wedderburn , NSW
Non-commercial-pleasure
Bankslown , NSW/Wedderburn, NSW
C1N
8321048
The pilot landed the aircraft on snow-covered ground to allow lhe external load to be re leased manually, as the normal release
system would not function. After the system was rectified and the load reconnected, the back of the left skid settled in the snow.
The pilot attempted to correct the situation but the main rotor struck the ground and the ai rcraft rolled over.
The pi lot misjudged the al ti tude on fin al approach and, before h e ini tiated the land flare, the aircraft s t ruck the ground heavi ly.
The landing gear collapsed and the aircra ft slid to a s top on the st rip.
04 Jun
1115
Beech A23 A VH-DEX
"N immie Stn.", NSW
Non-commercial-business
" Nimmie Sin.", NSW/"Nimmie Sln. ", NSW
15 Jun
11 40
05 Jun
1125
Cessna 182 P VH-IRL
Brunette Downs, NT
Non-commercial - pleasure
Tennant Creek, NT/Brunette Downs, NT
C1M, P1M
8321045
Immediately after becoming airborne the pilot turned the aircraft to the right. At 250 ft agl the flaps were retracted and the aircraft
rolled right and the nose dropped. The pilot applied full left rudder and aileron and pushed the control column forward . The
aircraft struck the ground with the wings level and b ounced 28 m before coming lo rest.
J
l
C1N, P1N
8341016
After crossing the threshold at 75 kt power was reduced to idle and a landing f lare commenced al about 25 ft agl. The ai rcraft
floated for some distance before the nosewheel contacted the ground heavily 400 m from the threshold. A bounce ensued
followed by a further heavy touchdown on the nosewheel which then collapsed and was torn off as the aircraft slid on its nose for
98 m.
05 Jun
1324
Bell 47 J2A VH-DMR
Dagworth Stn., Old.
Commercial-aerial mustering
Galloway Stockyard/Galloway Stockyard
Pi per 25 235 VH -CPU
Naracoorte, SA 15S
17 Jun
1620
Cessna 404 VH-ARO
Coo langal ta, Old.
Sched uled passenger service - commute
Lismore, NSW/Coolangatla, Old.
C1N , P10N
8311037
On ap proach the undercarriage down in dications were normal. H owever, when the nosewhee l was lowered after touchdown, the
nosewheel leg collapsed and the nose sect ion impact ed th e runway.
17 Jun
0735
Cessna 310 0
Exeter, NSW
V H-RIX
Charter-cargo
Sydney, NSW/Canberra, ACT
C1N
8321 050
The pilo t was unable to proceed to his planned des ti nat ion becau se of fog at th at aerod rome and had diver ted to ano ther tha t he
believed was suitable. Whi lst on a descent be low lowest safe altitude in clou d, the top o f the fin and rudder of the aircraft st ruck
l he lower two cables of an array of eight power cab les. The approx imate heighl of the cab les struck was 23 ft agl.
C1M , P1M
8311 032
Whilst cattle mustering al approximately 100 ft agl the pilot heard a loud metallic no ise. Au lo-rotation was commenced but during
the final stages of the approach the tail rotor struck a tree. The right skid then st ruck an anth ill and the aircraft rolled over
throwing the seat containing the pilot clear. After the passenger freed himself from the wreckage, fire broke ou t and the aircraft
was destroyed.
06 Jun
1400
Piper 31 350 VH -DVX
Charter- passenger
C1S, P1F, P2S
8341020
M oomba, SA 9E
Moomba, SA/Du lli ngari, SA
Shortly after takeoff, at about 500 ft ag l, bo th engines began to loose power. As the airspeed decayed the pi lo t was unable to
maintain st raight and level fl ight, and inilialed a descendin g righ t turn . A t about this lime lhe right engine fai led completely. The
ai rcraft t hen impacted wi th the ground at a relative ly slow speed and caught fire after a groundslide.
18 Jun
1204
Beech A36 VH -BFB
Coifs Harbour, NSW
Instructional - dual
Coifs Harbour, NSW/Coffs Harbour, NSW
C2N, P1N
8321049
The student was undergoing instruction for his init ial check on a retractable undercarriage type . Du ring the c i rcuit train ing,
touch-and-go landings were carried out , with the in structor calling he had iden tified the flap lever an d se lect ing i t up. Alter the
second land ing lhe instruc tor called and se lected the flap up. However, the s t udent attempted to se lect flaps up but inadver tent ly
selected the underc arriage up and the aircraft settled on the runway.
Commercial-aerial agriculture/bait i ng
Bool Lagoon,SA/Bool Lagoon, SA
C1N
8341017
The agricultural strip used for th is operation was situated on the top of a ridge and contai ned three bends in it s 395 m length. The
average width of the strip was 8 m, the sides then falling away at an average angle o f 25 degrees. After a takeo ff run of 225 m the
aircraft left the strip at the second bend, continued down the steep slope and became airborne just before co lliding with trees.
20 Jun
0715
Bel l 47 G5A V H-AAW
Normanton, Old. 59S
Ferry
Mogoura Sin., Old./Washpool Camp, Old .
C1F
8311038
06 Jun
0930
Hiller UH12-E VH-MKZ
Tingoora, Old.
Commercial-aerial agriculture/baiting
Tingoora, Old./Tingoora, Old.
07 Jun
1255
Piper 28 R180 VH-PFB
Cessnock, NSW 4E
Non-commercial - pleasure
Warnervale, NSW/Moree, NSW
C1N, P3N
8321046
While the aircraft was cruisi ng at 2000 ft amsl below an overcast at 2500 ft amsl, a large bird stru ck the outer leading edge of the
left wing .
20 Jun
1255
Embrae r 110 P2
Sydney, NSW
C3N
8321051
Just after takeoff th e top right eng ine cowl separated from ils mountings and s truck the right horizont al stabil iser . The cowl
remained attached to the stab i liser caus i ng severe buffet ing and a s ubs tantial loss of pitch control. T he aircraft was landed
immediate ly on a c ross runway .
08 Jun
1630
Piper 28-1 61 VH-AAS
Alice Springs, NT
Instructional-solo- supervised
Alice Sprin gs, NT/Alice Springs, NT
26 Jun
1545
Cessna 182 P VH-PKM
Flinders Is., Tas.
C1N
8311034
On the completion of each spray run the pilot was flying under power lines. On this partic ular run th e pi lot diverted t he aircraft
slightly to avoid a veh icle. The main rotor blades struck the power lines.
The helicopter was cruisi ng at approximately 200 ft agl. An observer saw an object fly horizontally from the he licopter. The
helicopter then turned th rough 90 degrees to the left, rol led to the left and spun through 360 deg rees before impacting the ground
inverted. The hel icopter exploded on impact.
C1N
834101 8
The student pilot carried out two dual, left -hand circuits before being sent solo again. On the first solo circ uit of the consolidation
a right-hand pattern and an extended downwind leg were required by the controller, due to other traffic. On final approach the
aircraft was above the normal path and on level-off the aircraft balloo ned. On to uchdown the aircraft bounced and then touched
down nosewheel first. The nose strut broke off and the aircraft slid to a halt.
09 Jun
0945
Piper 28 235 VH-BUJ
Bathurst,, NSW
Non-commercial-pleasure
Bankstown, NSW/Bathurst, NSW
C1N, P1N
8321047
While the aircraft was taxiing along a road after landing, its left wing struck a fence post. The ai rcraft tu rned to the left and the
propeller also struck the fence.
09 Jun
1700
Cessna A188B A1
Hyden , WA 13NW
Commercial - assoc. agriculture/baiting
Hyden, WA 15NW/Hyden , WA SNEE
11 Jun
1017
Cessna 172 N VH-TEU
lnjune, Old. 70NW
VH-EJU
C1N
8351018
Shortly after takeoff the pilot noticed that there was no indication of ai rspeed. The pi lot pushed the control co lumn forward and
the aircraft collided with the ground causing the right main gear to detach and strike the right tai lplane. The aircraft bounced back
into the air and climbed steeply before the pilot was able to lower the nose by a combinat ion o f forward control column and
reduced power. The aircraft crashed 200 m farther on from the initial impac t po int.
Non-commercial-pleasure
Archerfield, Old./Bandana, Old.
C1M, P2N
8311 035
The pilot became un sure of her position and decided to land in a paddock near a homestead to confi rm t he locat ion. The paddock
was 270 m long and studded with a number of large trees. The aircraft touched down well int o t he paddock and the right w ing
struck a tree and was torn off. The left wing then struc k another tree and the aircraft turned to th e left and rolled inverted before
~o ming to rest.
iv I Aviation Safety Digest 118
V H-MWW
I nst rucl ional- check
Sydney, NSW/Bathurst, NSW
Non -commercial -pleasu re
Flinders Is., Tas ./Fl inders Is., Tas.
C 1N, P3N
8331016
The pilot was conduc ting pract ice c ircuits . On the fourth land ing the aircraft bounced twice . The pi lot at tempted to go around,
but the engine did not respond before the aircraft again contacted t he ground. The nosewhee l was dislodged and the nosegear
leg was torn of f during the ensu ing slide.
27 Jun
1608
Cessna 182 G VH-D FO
Coolangatta, Old. 4N
Non-commerc ial- pleasure
Redc liffe, Old./Lismore, NSW 15E
J
C1N
831 1039
Whilst cru ising at 1500 ft ams l the engi ne began to run ro ughly and backfire . The pi lot was unable to rec ti fy the problem and shut
the engi ne down. A forced land ing was carried out on a beach and after land ing the pilot found a fire i n the engine compartment.
He was unable to extinguish the fi re until the arrival of a fire tender from a nearby airport.
)
30 Jun
1635
Cessna 180 D VH-WFZ
Bundaberg, Old.
Non-commercial -pract ice
Bu ndaberg , Qld./Bundaberg, Old.
30 Jun
1415
Cessna A188 A2 VH-KVA
Perth, WA 275 NNE
Non-commercial -agricu l ture/survey
Good lands Farm, WA/Goodlands Farm, W A
C1N
3311040
The pilot had recently purchased the airc raft and had then completed a period of d ual ins truction to re-fam iliarise himself w ith
tail wheel airc raft. To co nsol idate this instruction the pilot was to carry ou t a period of solo circu i ts. On the firs t land ing, just aft er
touchdown , the aircraft veered to the right and the le ft w ing an d elevator s truck the ground . The aircraft came to rest on the
runway, h eading 90 deg rees from the land ing direction.
C 1N
8351019
The landing was made on a private strip in strong gusty crossw ind cond itions. About 150 m after touchdown lhe aircraft swung to
the right and ran of f the s ide of the strip on to new ly cultivated so il. The left main wheel was torn off and the propeller ben t.
Aviation Safety Digest 118 I v
�FINAL UPDATES (The investigat ion of the fol lowing accidents has been comp leted. The informat ion is
add it ional to that previo us ly printed in t he preliminary report)
FINAL REPORTS (The invest igation of the follow ing accidents has been completed)
Date
Time
Pilot licence
Aircraft type & registration
Location
Age
Kind of flying
Departure/Destination
Hours Total
Hours on Type Ra ting
Injuries
Recorded
number
02 Apr
Beech C23 VH-SHP
Non-commercial-pleasure
C1 N
1034
Jandakot, WA
Quairading, WA/Jandakot, WA
8351012
Private
41
135
4
None
On the first landing attempt the aircraft was flared too high and settled heavily on to the runway. Th e pilot carried ou t a go-around .
On the second approach the pilot again flared too high resulting in a heavy bounced landing, during which the nosewheel st ruck
the runway with sufficient force to collapse the nose strut.
14 Apr
0820
Private
Cessna 172-P VH-JRC
Cue, WA 111W
20
Non-commercial - aerial mustering
Meka Station , WA/Meka Station, WA
228
177
None
16 Apr
H iller UH12-E VH-FXX
Commercial-aerial mustering
C1N, P1S
1120
Byerwen Sin., 13S
Byerwen Stn., Qld./Byerwen St n., Qld.
8311024
Commercial
Hel icopter
47
3500
2000
None
The helicopter was climbing to about 20 ft agl and entered a hover under overhanging branches o f a tal l eucalyptus tree. Th ere
was a lo ud bang and the helicopter began to vibrate and rotate to the right. The pi lot was unable to regain control and the
helicopter landed heavi ly in a nose-down attitude. A witness reported seeing a large dead branch fall from the tree int o the main
rotor system.
30 Apr
1230
Commercial
Airparts 24 950
Dysart, Tas .
VH-KSF
50
' C1N
Commercial -aer ial ag riculture/bai ting
8331013
Dysart, Tas./Dysa rt, Tas.
20 OOO
7000
Agric. Class 1
On cl imbout to the spreading area o n the second flight of the day the pil ot saw power lines ahead. He attempted t o fly below
them, but the aircraft struck the lines and dropped to the ground com in g to rest on its whee ls in a turnip field.
Record number
Age
Hours Iota!
Hours on type
Rating
02 Jan
Private restr icted
8321001
21
64
11
None
415
300
Instrument Rat ing Class 4
The pi lot did no t ini tiate a go-around.
04 Jan
Private
8311002
40
The pilot , who was in experienced in j udging local conditions and effec ts, had underestima ted the wind st rengt h. The downwind
componen t for landing was 10 to 15 kt. Although the aircraft floated we ll beyond the targe t touchdown point the pi lot d id not
initiate a go-around.
C1 N
8351014
Whilst sheep spotting at 500 ft agl, the pilot turned the aircraft in an attempt to keep the sheep in sight. He progressively
tightened the turn until the aircraft was in a steep turn with a nose-low attitude. The pilo t attempted to recover from the I urn but
the aircraft struck the ground.
The investigation established that the airc raft was s talled while in a steep turn i n close proxim ity to the ground.
Date
Pilot licence
•
•
07 Jan
Commercial helicop.
8311 003
29
07 Jan
Pri vat e rest ric ted
8321005
20
17 Jan
Glider
8351002
35
3860
None
2640
Fuel lines to two cylinders were found abraded by their c lamps and one line was frac tured. The pilot was operating just above the
trees and he was unable to manoeuvre for a successf ul landing due to the lack of engine power.
236
None
190
There was ample space to land on either side of the next glider to be towed. By making a maximum performance land in g in the
short dis tance behind the flider, th e pilot gave himself little room to manoeuvre, to correct for the d ist urbance caused by the
willy-w i lly.
933
250
Glider Rating
Fol lowing !he low pass, the glider was too slow to make a normal circuit. A irspeed was further reduced as the pilot attempted to
manoeuvre for a landing on one of the s trips. There were c lear paddocks , sui table for land ing, adjacent to the aerod rome but t he
rules required tha t the lan ding be on a s trip for th e record attem pt to be valid.
23 Jan
Comme rcial
8331002
26
29 Jan
Private restricted
8341 002
30
The pilot intended using one stage of flap and rotating at 60 kl due to the soft condition o f the s trip. The gear was retracted just
after the aircraft became ai rborne and the aircraft sank back to the ground.
09 Feb
Commercial
8311008
58
The gear was retracted prior to a p ositive rate-of-climb being established and at a speed such that the changes in trim and drag
had a marked effec t on aircraft performance.
The low performance detected by the pilot was caused by poor seating of an exhaust valve and the assoc iated reduced power
output.
01 Jun
Hughes 269 C VH-CHV
Ferry
C1 N
1720
Hi ghbury O.S., Qld.
Drumduff Outstat ion/Hig hbury O.S., Qld.
831 1031
Commercial
Hel icopter
26
763
763
Inst. Rat. Class 4
The pilo t was posit ioning the helicopt er for a periodic chec k on the following day. Dur ing his approach he saw the too lboxes to be
used, and decided to land near them. A dusty area was en countered so the pilot moved towards a grassed area. Th e main rotor
struck a branch and the pilot instinctively acted to move the helicopter away from the tree, but th is caused the rotor to move up
and strike a large branch.
In attempting to ease hi s eng ineer's work load the pilo t had posit ioned th e helicopter under tree branches and he had fai led to
no tice one large bran ch protruding from the main fo liage.
10 Feb
Private
8311009
60
14 Feb
Private restric ted
8311011
34
73
6
None
21 Feb
Private
831 1014
35
650
Unknown
None
06 Mar
Private
8331005
24
306
84
Instrument Rat ing Class 4
10 Mar
Private
831 1018
66
3326
2594
None
Although the pilot had operated from the strip many limes over nine years, he was unaware of the power lines. He d id not see
the lines during an aerial inspection or on the first spreading fli ght. The lines were strung across a valley betwee n a pole hidden
by trees at the top of a r idge and a pole lower down on the other sid e. T he span was 900 m and light c ondi tions we re dull.
29 May
1530
Private
06 Jun
1650
Private
Beech E33 VH-BZQ
Hebel, Qld.
37
Cessna R182 VH-TMJ
Toowoomba, Qld .
41
Non -commercial -pleasure
Hebel, Qld./Mungi ndi, Qld.
500
330
C1 N, P2N
831 1030
1800
80
400
80
Examination of t he eng in e found no reason for th e reported rough runn ing.
Instrument Rating 1s t or C lass 1 and
Flight Instructor
None
None
Non-commercial - busin ess
Thall on, Qld./Toowoomba, Qld .
250
24
None
C1 N, P3N
8311033
On landing the aircraft bounced and the nosewheel tyre deflated. As the pi lot was turn ing the aircraft off the runway the
nosewheel s trut entered soft ground and collapsed.
3000
2700
Instrument Rating Class 4
1500
None
600
Inves ti gation fai led to reveal evidence o f an engine material failure. A t mospher ic condit ions at the time were conduc ive to
carbu rettor ici ng, and the aircraft flew close to operating watersprinklers on the st rip d uring the low pass.
The pilo t had misjudged hi s land ing flare, probably because sunglare had rest ri cted his forward visibi lity. The wi nd at the t ime
was light, and a runway not affected b y sunglare was available for landing.
21 Jun
1203
Commercial
Beech 36 VH-FWL
Moorabbi n, Vic.
19
Instructional -so lo -superv ised
C1 N
Moorabbin , Vic ./Moorabbin, Vi c
833101 5
272
1
Instrument Rating Class 4
and Flight Ins tructor
The pilot dec ided to practi se some touch-and-go landings because he had not flown an ai rcraft for some considerable lime.
During the landing roll of th e second touch -an d-go the pi lot inadvertently selected gear up instead of flap up. The ai rcraft stopped
after sliding 70 m on the partially retracted landing gear.
Subsequent exami nation establi shed that both the landing gear sq uat switch and land ing gear unsafe warning horn were
serviceable. It is probable that there was in suffic ient weigh t on the landing gear to operate the squat switc h.
vi I Aviation Safety Digest 118
Aviation Safety Digest 118 I vii
�~et
George do it - but watth him !
A co m mercial D C-10 departed Frankfurt at about 2200
hours local t ime on an IFR flight plan to Miami . There
were 295 passenger s, three crewmembers and 13 fl ight
attendants on board. Ground operations, take-off and
the ini tial portion or the en route cl imb were
u neve ntful. Air T raffic Control cleared the trijet to
cl im b at 283 knots, the appropriate speed for the heavy
weight of the aircraft. The captain controlled the
a ircraft manually to 10 OOO feet. According to the crew,
after reaching 10 OOO feet the autopilot (AP) was
engaged in the ind icated airspeed (IAS) hold mode and
the autothrott le system (AT S) speed selector was set at
320 knots. Climbing through 14 OOO feet the autopilot
disengaged, a nd was q uickly re-engaged by t he pilot .
A few m inu tes later, while climbing through 27 500
feet about 100 miles west of the departure airport, the
D C-10 started to vibrate slightly which, within seconds,
increased in in tensity. The crew suspected an abnormal
vib ration in n u mber th ree engine, elected to reduce
power and then to shut it down. As soon as they
red uced power on n umber three engine, the autopilot
d isengaged, th e a ircraft rolled first right, then left, and
then the nose sudden ly pitched down and they started
to lose alt itude r ap idly.
As th e aircraft 's nose continued to drop, the captain
deployed the spoilers to arrest the impending overspeed
conditio n created by t he aircraft's nose-low attitude.
The Dight recorder readout showed the recovery
starting a t 23 900 feet with vertical acceleration
reaching a maximu m of 1.68g during the recovery. The
crew regained full con trol of the aircraft at about
18 OOO feet.
Sho rtly after recovering control of the DC-10, the
cr ew restarted n umber three engine and it appeared to
fu nction no rmally. T hey had requested a diversion to
Madr id , but since all systems appeared normal, the
crew elected to conti nue to Miami as if nothing had
happened. T he fl ight landed at Miami at 0105 local
time .
After sh utting down , the captai n asked maintenance
person nel to visually check the aircraft's exterior .
Mainte nance found that the 4 feet of each outboard
elevator ti p and the a ircraft's tail-a rea-lower-access door
were missing. The DC -10 was grounded at Miami
where it un derwent a thorough examination . All
systems tha t co uld have induced the condition
exper ienced by the crew du ring the incident were
fu nctionally checked. These included the flight control
systems, the au tothrottle system, the night
d irector/autopilot and the number three engine. No
malfunctio ns were found.
Analysis
The a ircraft 's fl ight control systems a nd power plants
operated norma ll y both before and after the incident.
T here was no evidence that any malfunction of the
aircraft systems had occurred. The structural damage,
wh ich was lim ited to the empennage and aft fuselage,
was a ttributed to th e application of high loads caused
by the stall buffet. No indication of pre-existing fatigue
cracking was d iscovered.
viii I Aviation Safety Digest 718
The flight data recorder indicated that the' aircraft's
airspeed continued to decrease during the climb . The
stall speed of the D C-10 for its climb weight was
determined to be 203 knots and the buffet onset speed
was apprnximately 234 knots . According to the flight
recorder, the aircraft was operated below 234 knots for
over 40 seconds while climbing above 26 OOO feet. For
half of this period, the airspeed was below 203 knots.
The minimum speed recorded during this portion of the
climb was 176 knots, well below the stall speed. The
National Transpo1·tation Safety Board (NTSB)
concluded that the DC- 10 entered a full aerodynamic
stall.
Why would an experienced, professional fligh tcrew
unknowingly allow a DC -10 aircraft to fly into a full
aerodynamic stall? Evidence clearly indicates the
aircraft was maintaining a constant vertical speed
( 1200 feet per minute) during the period immediately
preceding the stall, and thrust from all three engines
was at an autothrottle limiting value for several minutes
during which pi tch attitude increased and airspeed
decreased . Here the D C - lO's au topilot system was
commanding aircraft pitch attitude and the autoth.rottle
system was controlling thrust during the climb . T he
aircrew had mistakenly placed the autopilot system in a
vertical speed mode rather than an airspeed or Mach
command mode. This was contrary to both the airline's
normal procedures and the manufacturer's prescribed
normal operating procedures and recommendatio ns.
From the time the pilot re-engaged the autopilot, up
to the point the aircraft stalled at 28 800 feet, the
D C -10 was in this vert ical speed mode. Meanwhile,
airspeed was bleeding off and the aircrew were not
aware of it. The autopilot was commanding an
increasing pitch attitude necessary to achieve the
selected vertica l speed, 1·egardless of the aircraft's
airspeed or pitch attitude (which increased to 14 degrees
nose up). Add the DC- lO's stickshaker alert (wh ich
investigators determined was indeed activated) to the
situation and you have m ultiple warnings available to
alert an aircrew of an impending stall.
The Safety Board concluded that the crew's attention
must have been diverted from the control of the a ircraft
and from instrument scan soon after re-engaging the
autopilot at 14 OOO feet. Believing that the autopilot was
effectively maintaining a satisfactory climb attitude and
speed, they were probably quite surprised at the onset
of sudden vib rations, buffeting, and activation of the
control column 'stickshaker' . They consequen tly
misinte1·preted the cues as an engine problem. When
they retarded the number three engine throttle, the
resultant decrease in total thrust along with the thrust
asymmetry only aggravated the aircraft's entry into a
full stall.
Probable cause
The NTSB determined that the probable cause of this
occurrence was the failure of the flight crew to follow
standard climb procedures and to adequately monitor
the aircraft's flight instruments. Their inattention
(continued on page 15)
Aviation Safety Digest 118 I 13
�Let George do it -
Bird
proofing
parked
aircraft
but watch him!
(continued from page 13)
Birds bu ild ing n ests in the various nooks and crannies
of aircraft rema in a pe rsistent problem . While the
accompanyi ng photogr aphs of a prospective tenant
ch ecking o ut its new home may appear amusing, the
pilot who finds h is con trols jammed inflight is anything
b u t amu sed (sec Avialion Safety Digest 107, page 28).
Obviously, it is impossible to block off all available
nesti ng sites, bu t th e La trobe Valley Aero Club, for
o ne, has taken a posit ive measure to deny birds entry to
the en gine area - on e of the most popular places for
nests. This cons ists of using blanks which fit in to the
e ngine cooling open ings in the engine cowls. D etails of
the blanks are as follows:
• ma de fro m low-density polyurethane foam
• cut ou t with the a id of a template and an electric
carving knife
• red ribbons attached as warning flags.
The blanks can be inser ted after allowing a few
m inutes fo r the en gine to cool and are especially useful
during the sprin g and early summer when starlings are
nesting. T he use of such blanks or covers would never,
of course , o bvia te the need fo r a detailed visual check of
possible nest ing sites •
resulted in the j etliner entering a prolonged' stall buffet
which placed the aircraft outside the design envelope.
A lthough the crew failed to recognise the approach
and en try to the stall they did, after approximately 1
minute, recognise the aircraft's stalled condition. They
also responded with proper control inputs to recover the
aircraft. A full m inute for stall recognition is excessive,
however , and at a lower alti tude it could have very well
caused the destruction of the aircraft and the deaths of
hundreds of passengers.
The Safety Board a lso believed either a visual or
aural warning device for the DC-10 would have aided
the crew's stall recognition problem and might have
prevented the material damage to the aircraft by
causing the crew to react faster.
In this mishap the crew flew a transocean ic crossing
to their destination after the occu r rence. T he violent
and unexpected nature of the stall and recovery
manoeuvre and the crew's lack of understanding as to
why it happened should have been sufficient reason to
get the plane on the ground as quickly as possible.
Normal caution should have dictated this action.
In this case, ' letting George do it' would have been
fine if someone had taken a more active interest in what
'George' was doing •
Adapted from The M ac Flyer
Going••.
-
*
*
*
Operations from dirt airstrips
(Tha11ks to the L atrobe Valley A ero Club for this contribution.)
A brief item on page 18 of A viation Safety Digest 11 6
mentioned the danger of mud collecting in aircraft
wheel fairings. The item outlined the case of a PA28
which had been operating from a dirt airstrip and
which, d uring a wheel a nd brake inspection , was fou nd
to have nearly 10 kilograms of dirt caked inside each
fairing . Clearly , this constituted a possible impediment
to wheel rotation and braking.
Since that item was written, a Jodel fitted with spats
a nd operating from a wet, black soil strip nosed over on
takeoff. The spats had filled with mud during the
takeoff roll and prevented wheel rotation.
W hile damage was minor, the incident could have
ha d far more serious consequences. Had the aircraft
become airbo rne just before the spats filled, the black
so il m ay well have solidified durin g flight, setting up
the a ircraft for an immediate noseover on landing, with
all its attendant dangers fo r the pilot.
As the item in Digest 116 suggested, for sustained
soft-field operations, temporary removal of wheel
fairings should be considered. If this is done,
engineering regulations, and the effect of removing the
fairin gs on weight and balance, must be taken into
account. If re moval of the fairings is impractical, then a
thorough visual inspection should be completed before
each flight •
Aviation Safety Digest 118 I 15
�Use your P-charts
There was no flight manual in the aircraft
so the pilot 'eyeballed' the length of the
strip aud decided it was adequate . . .
. . . takeoff weight exceeded the climb
weight limit stipulated in the P-charts . . .
. .. the pilot did not use his P-charts
correctl y . . .
. . . this ALA was too short for the
particular aircraft to use for takeoff .
. . . aad this one too short for landing.
16 I Aviation Safety Digest 118
A Cessna 210 was substantially damaged when it ran
o ff t he end of a land ing area and down a gully .
Although the land ing area was 600 metres long, its
effecti ve length for takeoff and landing was reduced to
450 metres because o f the infrin gement of trees on the
approach /depart ure paths. Fmther, the area sloped
down in the d irection the pilot landed at an average
gradient of m inus 2 per cent. T he pilot later recalled
tha t h e had used an approach speed of about 85 knots,
and thought that he crossed the threshold 10- 15 feet
high at a bou t 75 knots .
The land ing distance actually required was
subsequently calcula ted from the aircraft's flight manual
using the following info r mation:
1446 kg
aircraft landin g weight
600 feet
airfield pressure height
33°C
tem perature
strip g rad ie nt
minus 2 per cent
h eadwind component
7 knots
The distan ce req uired under the above cond itions
was fo und to be 633 metres and the approach speed
69 knots; that is, the landing distance available was
183 metres shorter tha n that based on a speed some
6 knots slower than the actual approach speed flown.
H ad the pilot consulted his aircraft's land ing chart
during h is p refl ight plan ning, he would have been
aware o f th is, and the accident could have been
avo ided.
Accidents which arc attributable to a pilot's fa ilure to
use performance charts are an unfortunately persistent
feature of Australian General Aviation. Of these
accidents, those related lo inadequate takeoff or landing
distances are the most p1·evalent.
P-charts
Basically there are three publications to wh ich a pilot
may refer to obtain performance information for his
aircraft. T hese are:
•
the owner's manual
•
the pilot's operating handbook
•
the flight manual issued and approved by the
Department of Aviation
The owner's manual and pilo t 's operating handbook
are produced by the aircraft manufacturer and include
performance information fc.ll" a range of situations range, end urance, en rou te power settings etc. They
also include takeoff and landing data, but it is most
important to note that this particular information is not
authorised for Australian operations . The only
approved takeoff and landing data a re those in the
flight manual issued by the Department of Aviation,
and it is those landing weight charts and takeoff weight
charts - generally referred to as P-charts - which
pilots must consult to determine their aircraft 's takeoff
and landing distance/weight limits.
A viation Safety Digest 118 I 17
�It is a requirement of the Air Navigation Regulations
that the fiighL manua l be carried in the aircraft at all
times. From the information it contains a pilot can
determine the suitability of an aerodrome for the
operation of his aircraft, or the maximum weight at
which he can operate the aircraft from a give n runway
01· strip.
When to use P·charts
In the majority of accidents like the one described al
the start of this article , the basic problem arises when a
pilot does not check his P -charts and/or does not obtain
an accurate measurement of the strip length.
It is not, of course, necessary to consult the charts
before every llight . Obviously if you are taking off or
landing on a 3000 metre runway in a light airci-aft there
is no need to check takeoff or landing data charts. But
where is the dividing line - 700 , 1000 or 1500 metres?
This will be decided by a large numbe1· of variables,
and only by reference to the P-charts can the safety or otherwise - of that particular phase of fl ight be
properly determined.
Any time there is the sl igh test doubt about your
aircraft's performance capability, the charts must be
u sed . You may be concerned by any one of a number
of factors: the length an d/o r· condition of the runway, a
high-density altitude, a recogn it ion of your own
limitations or a lack of familiarit y with the equipm ent
you are flying are just some factors which may crea te
doubt. In all cases, those doubts can be allev iated by
refe1·ence to the P -charts. They will give you the
information you need to enable you to p lan your
operations to cater fo r the prevailing conditio ns. For
example, it may become apparent to you by consulting
your P-charts that the load you intend carr ying is
excessive for the conditions, and that e ither passengers ,
cargo or fuel will have to be off-loaded . Indeed, it may
even become clea r - as it has after the event to some
pilots - that a strip you would like to use is inadequate
regardless of your aircraft 's all -up we ight.
The fo llowing sections of this a rticle discuss the use of
P-charts in aircraft with a maximum AUW of less than
5700 kg. There are sometim es mino r differe nces
between the P-charts issued for different aircraft types,
but those used here remain representative of the
common format.
Using the P-charts
Landing weight charts. The key informatio n wh ich
can be obtained frofI1 your aircraft 's landin g weight
chart is that of the m ax imum landin g weight a t which
your aircraft can be safely operated into a strip of a
particular length . Variab les which a re allo wed for
include ai rfield pressure height , temperature , st1·ip
gradient and the wind compone nt. The data a re based
on an a ircra ft makin g an approach at a speed of not
less than 1.3Vs (Vs be in g the stall speed) lo within
50 feet of the landin g surface, i.e. th ey a llow for a 50
foot obstacle clearance . Data ob tained are increased by
a fac tor of from 1.1 5 to 1.43 (depend in g on max imum
cer tified ta keoff we ight) to cater for such variations as
pilot h andling techniques a nd abilities, a nd a ircraft age
a nd condition .
The landin g weight cha rt at Figure l is typical of
18 I Aviation S afety Digest 778
those in flight man uals. In this case the p ilot wishes to
land on a strip 600 metres lon g . Following the example
through, th e pressure height of the strip is 6500 feet ,
temperalure +5°C, the strip is level and there is zero
wind; therefore , the maximum land in g weight at which
the aircraft can be flown in to the str ip is 1330 kg. A
flap setting of 30 degrees and an approach speed of
77 knots IAS are stipulated.
Note that density he ight and climb weight limit
information is also in cluded on thi s chart. The climb
weight limi t is important should a baulked approach be
necessary as, for a given pressure height, it defi nes the
maximum weight at wh ich the a ircraft will achieve the
stipulated climb grad ie nt of 3.2 per cent at takeoff
power, in the landing configuration , and at a speed not
exceeding 1. 3Vs. In the exa mple, with a pressu re
height or 6500 feet , this maximum allowable weight is
1360 kg.
Takeoff weight charts. Like the landing P-chart, the
takeoff chart allows for a 50 foot obstacle clearance a nd
includes a safet y factor of from 1.15 to 1.25 (depen'ding
on maximum certified takeoff weight ). In addition to
the variables included in the landing chart, the takeoff
chart provided as an example at Figure .2 also makes
allowance for the nature of the airstrip's surface.
Following the example throu gh, the airfield pressu re
height is 2200 feet and the temperature + 30 °C . The
strip is 600 metres long, its surface is short wet or long
dry grass, and it is level. With a l 0 knot headwi nd , the
maximum permissible takeoff weight is 1320 kg. Note
that takeo ff power and flap setting are stipulated, while
a takeoff safety speed o f 75 knots is also defined (this is
the speed to which the aircraft m ust be accelerated in
establish ing the takeoff d istance requ ired) .
Note a lso that a climb weight limit is defined (in this
example, 1550 kg) . T his is the max imum weight at
which, for a given ai rfield density height, and in the
takeoff configuration with the landing gear extended ,
the aircraft will be able to achieve the stipula ted climb
gradient of 6 per cent a t takeoff safety speed and ta keoff
power.
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Summary
The use of P-charls is vital in p refl ight planning. I t may
be tempting to 'eyeball' the variables affecting your
fligh t and decide that your aircraft will be able lo g ive
you the performance you need, but the fact is that sma ll
changes in operating cond itio ns can o ften sign ificantly
reduce an aircraft's capabili ties. Pilo ts mu st be
thoroughl y fam iliar with t he charts applicable t o their
aircraft, and th ey mu st consult them on any occasion
the sli ghtest doubt ex ists rega rding t heir aircraft's
capabilities in any g iven situat io n. Preflight preparatio n
is the basis of air safety •
TAKE-OFF
SAFETY
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Figure 2
A viation Safety Digest 778 I 19
�An ill wind
wind
velocity
Description
C a lm
L igh t a ir
Gentle breeze
15knots
30knots
W ind speed (knotJ)
1
1-3
7- 10
11-16
Visual clues
C alm ; smoke rises vertically.
D irection of wind shown by smoke -d ri ft bu t not by wind
vanes.
W ind extends light flag; leaves a nd small twigs in constant
mot ion.
R aises d ust and loose paper ; small branches are moved.
Moderate breeze
Fresh breeze
17-21
Sm all trees in leaf begin to sway; crested wavelets for m on
inland wa ters .
Stron g breeze
22- 27
Large bra nches in m otion .
Nea r gale
28-33
Whole trees in m otion .
G ale
34- 40
Breaks twigs off trees.
N ote that if it is possible to determine the wind speed, then the d irection shou ld be obvious.
T he e ffect of wind on the landing p erformance of
aircraft is one of the first a nd most fund a mental
l essons of fl y ing tau ght to all pilo ts . As a n
individual 's exp erience level a nd skills increase , so
too does his or her ability to safely accommodate
more d e m a nding la nding conditions.
N otwithstanding this , no pilot ca n afford to ignore
the likely effect of wind; a careful assess ment of
surface conditions is essential b efore a ny landing is
a ttempted. T his a rticle review s a n accid ent in which
a pilot did no t assess the wind speed , la nded w ith
an extremely stro n g tail wind, and substantially
d am a ged his a irc ra ft, a Beech Bo n a nza, when he
o verran a 75 8 m etre la nding a rea.
The accident
T he p ilot had a rra nged to take some of his fami ly a nd
friends o ut to his country property. Includ in g the pilot
the pa rty numbered fi ve and , wi th the fuel load carried ,
the a ircraft 's weight qnd centre of gravity we re
com fortably within limits.
After a mid-m orning departure a rout ine fli gh t to the
property was m ade. Because the strip - which was
aligned 155/335 degrees - sloped up towa rds the
south-east , the pilot was in the habit of a lways land in g
in the 155 d egrees direction. The gradient was 5 per
cent for abou t the first third of the strip d ecreasing to J
pe r cent for about the last half.
The re was not a windsock a t the lan ding a rea , but a
nearby windmill was often u sed to gauge the wind . T he
pilot noted from the tail vane that the wi nd direction
was fro m the north-west, blowin g a lmost stra ight down
the J 55 degrees strip . As the mill's rota ry vanes were
locked a t the time th ey could no t be used to estim ate
20 I Aviation Safety Digest 118
the wind speed. H owever , the pilot was con fide nt tha t
conditions wo uld be sati sfactory as he had spoken by
telep hone to the p rope rty ma nager a nd a nother pilot
earlie r in the morni ng a nd both had reported the
weather as fine.
T he approach seemed satisfacto ry to the pilot, who
later recalled tha t the a irspeed ind icator was registering
a bout 80 knots - th e speed he was aim ing for - on
final. H e planned to land a t a poi n t abou t 220 metres
from the threshold , which was the crest of the 5 per
cent gradient. The ai rcrafl actu ally touched down 300
m etres fro m the threshold and the p ilot sta ted tha t he
ex pe ri enced difficul ty in get ting the ai rcraft to ' stick ' on
the gro und . H e q ui ckly realised tha t he was go ing to
have problems in stopp ing the a i1·cra ft before the e nd of
the runway and , as he considered a go-around was not
possible, began to app ly heavy braking . T h is d id not
have the desired e ffect , so in 01·der to stop he
delibera tely grou nd looped the a ircraft. This caused the
left ma in gear to collapse a nd the left ma in plane to
strike the ground .
After the aircra ft stopped the pilot sh ut down the
e ngine a nd turned off t he switches, a nd a ll of the
occupa nts exited the a ircraft un hurt. On ge tting o ut of
the a ircraft the p ilot was su rp rised by the strength o f
the wind, which he estim ated at 15- 20 knots.
Analysis
In fact, the wind speed was in the order of 30 knots,
almost directly down the 155 degrees stri p. Wh ile the
approach had seem ed norm a l to the pilot, several
witn esses subsequently recalled that the a ircraft seem ed
to be travelling 'very fas t ' on fi nal. Som e simple
calculations con firm that this must have been the case .
Based on the approach ai r speed of 80 knots, the
aircraft would have normally ach ieved a th reshold speed
of about 75 kn ots. In normal circumstances, assuming a
10 knot headwind, the ai rcraft's groundspeed just
befo re touch<low n would have been about 65 knots. In
this instance, with a 30 knot tai lwind, the groundspeed
woul<l ha ve been a bo ut 105 knots - an increase of
about 60 pe r cent on the norm!
W hile there were several factors contributin g to this
accident, the matter of the pilot's fail ure to assess the
wind speed is the most signi fi cant in terms of flight
safety: given tha t the pilot concerned con fin ed himself
to one -way operations on that particular strip, he
un doubtedly would have abandoned his a ttempts to
la nd there ha d he a ppreciated the strength of the
tailwind.
Assessing wind velocity
At the sta rt of this article it was m en tioned that one of
the firs t lesso ns given to p ilots is that of assessing the
e ffect of the wind on landing, a nd this lesson will
invaria bly include instruction on how to ' rea d' a
windsock. Every pilot shou ld know that a windsock
which is being blown ou t parallel to the ground
ind icates a wind of abou t 30 knots, wh ile one at 45
degrees to the vertical indicates abou t 15 knots (see
d iagra m) .
All authorised land in g areas (ALAs) should h ave a
suitable mea ns of determ inin g the wind velocity: at any
un ma nned aerodrome (including ALAs) a windsock
provides the best means by which a pilot can assess the
wind velocity. However , on occasions circumstances do
arise which cause pilots to land at areas where no
windsock is ava ila ble. If you find you rself in that
situation, then the above ta ble showing how to assess
wind speed may be of use. T his table is a n extract of
information provided to meteorological observers by the
Burea u of Meteorology .
Crosswind
W hile this discussion has concentrated on wind speed, it
is also most important for pilots to be able to assess any
crosswi nd component. Many P ilot's Operat ing
H andbooks contain graphs fo r th is. Sometimes,
however, it is difficul t to use graphs infligh t, so the
following guide may be of use:
If the wind direction is 30 degrees off runway heading, the
crosswind component will be half of the windspeed; for 45
degrees off it will be 0. 7; and for 60 degrees 0. 9.
For exam ple, if you were lan d ing on runway 36, the
following crosswi nds would apply:
Wind
330120
315/20
300/20
Crosswind factor
Crosswind component
0.5
10 knots
14 knots
18 knots
0. 7
0.9
Summary
While the effect of wind on landing performance is one
of the first and most im portant lessons taught to pilots,
some continue to ignore it - often to the ir regret.
A careful assessment of wind velocity - th a t is, both
d irection and speed - is essential before any land ing is
attempted. If circu mstances force you to lan d at an
aerodrome without a windsock, then you should be
prepared to be able to use the terrain to m ake your
assessment •
A viation Safety Digest 118 I 21
�approach, or that the door mi ght come loose on landing
and damage the la nding gear. Consequently, I elected
to continue to Moorabbin and advised M elbourne of
my intentions. Ground-air commu nication remained
very difficult - as did that inside the aircraft because of the high noise level.
. .
.
' I tracked to Moorabbin OCTA, avo1dmg built-up
areas as far as possible. A straight-in landing for
Runway 17C was approved, a nd 20 degree~ of flap only
was selected to minimise aircraft configuration changes.
The landing was poor because of my nervousness and
the fact that I did not trim out the drag-induced yaw on
fi nals but rather tried to hold the aircraft in balanced
flight' by use of the rudder. Although the landin g was
not as smooth as I would have wished, it was safe
enough, a nd I was able to taxi the aircraft to its tiedown point.
' Post-flight inspection revealed that the hinge pin on
the upper door hinge had sheared, allowing the leading
edge of the door to protr ude into the airflow; the
140 knot slipstream had then " peeled" the door open .
The restraining scrap stop ped the aft movement of the
door, while the wing strut stopped it dropping
downwards. It was also interesting to note that in its
final position, th e door was acting to " scoop" air into
the cabin.
'The only other thought I have had on this
occurrence which may be of use to other pilots con cerns
the temperature in the aircraft's cabin. When the door
came off the outside air temperature was plus 20
degrees Celsius. Had the door come off where the
aircraft was not in warm, dry air and only 20 minutes
from landing, th e wind-chill aspects may well have had
an important bearing on the outcome. '
~ea@i
Door open in flight
An a rticle in Aviation Safety Digest 11 5 discussed the
difficulties faced by the pilot of an aircraft on which
a door came open in flight. He suddenl y found
himself operating in a very noisy and disturbing
environment, allowed himself to become distracted
from his prime task - that of completing a safe
landing - and so his problems compounded.
Subsequent to printing that article, th e Digest
received a reader contribution concerning a similar
incident, and from which several valuable lesson s
can be drawn. Of particular interest is the way in
which the pilot assessed his situation , determined
courses of action open to him and then made his
decisions.
*
*
*
' I was returning from Condobol in to Moorabbin in a
Cessna 182RG with two passen gers. The weather
fo recast had been satisfactory and I had filed and flown
a VFR plan withou t an y difliculties . We had passed
Kilmore, planning to track to Moorabbin via Yan
Yean. C ruise altit ude was j u st below 3000 feet , whil e a
65 per cent power setting of 23 inches manifold
pressure and 2100 RPM was giving us the advertised
lAS of 135-140 knots. The only cloud was high above
us, while there was slight to moderate convect ive
turbulence. The wind was steady from the north -west a t
10-1 5 knots.
' Immediatel y before the incident we unexpectedly
e ncountered h eavy convecti ve turbulence whi ch resulted
in the Cessna sustaining two or three rapid and very
hard applica tions of positive g. These applications were
strong enough to make the aircraft's structure creak. At
that time I had my lefr ha nd on the control wheel and
was resting m y left elbow on the doo1·-mounted arm
rest, while my right hand was on the throttle. Because
of the severity of the turbulence, it was my intention to
close the throttle and reduce IAS.
'Suddenly, there was a very loud, sharp noise and a
flood of light poured into the cabin. The cockpi t was
scoured by a blast of air a nd a deafening roar; papers
and loose clothing started flying a bou t. This was
accompa nied by the aircraft yawi ng and rolling to the
left. At the same time -1 was startled to notice that there
was no thing between me and the ground - the left hand side of the aircraft seemed to have disappeared.
' M y first thought was that the ai rcraft had suffered a
structural failure , particularly as it did not immediately
respond to control inputs (later I concluded that this
was probably due to th e effect of the con ti nued
turbulence). In an attempt to regain control I closed the
throttle, extended the landing gear and slowed to 90
knot s. Having established control I started a descent,
put the mixture to rich , applied power, lowered 10
degrees of flap and maintained 85 knots. Although
skiddi ng to the right, the aircraft remained controllable.
The no ise level was very hi gh.
22 I A viation Safety Digest 118
'At this stage I remembered m y rear-scat passenger
and, looking back over m y right shou lder , was re li eved
to sec tha t he was still there . I decla red a PAN to
Melbourne Flight Serv ice, advising the m that I thought
the left-hand door had completely separntcd from the
aircraft. Just after this R /T call I no ticed tha t the door
was still with us; it was ha nging b y its restraining stra p
(which is meant to prevent the door from opening too
far) and appeared to be resting on the undercarriage leg
or the wing strut. T he combinati on of these restraints
and the ai rload s see med to be holding the door in place.
However , I noticed that when I applied rudder to
correct the aircraft 's skid , the door began to flap
alarmingly. Needless lo say, I did not persist with
attempts to remove the skid .
Aircraft tyre care
Maintaining the correct inflation pressure in an
aircraft tyre is one of the most essential factors in
obtaining maximum safe service life. Inner' tubes
and tubeless tyre liners used in most automotive
tyres are made of butyl rubber. Most aircraft
inner tubes and tubeless tyre liners, on the other
hand, are made of natural rubber to satisfy
extreme low temperature performance
requirements. Natural rubber is a poor air
retainer when compared with butyl rubber. This
accounts for the comparatively high daily air
pressure loss and need for frequent pressure
checks of aircraft tyres.
Daily inspection of tyres includes checking the
pressure. This can only be done properly with
calibrated gauges. Do not let an improperly
serviced tyre cause an aircraft accident/incident or
injury to personnel. Ensure that tyre-servicing
equipment is in good working condition and
properly calibrated •
.
You were saymg
....?
A Flight Engineer Union representative in the
U .S.A . was appearing before a Presidential
committee enquiring into airline flight crew
complements. After describing the necessity for a
'third pair of eyes' in the cockpit, the
representative stood up and walked into a broom
closet on his way out of the hearing •
In brief
'The fact that the door was still on the aircraft
introdu ced a new factor as well as those I already had
to assess before deciding what to do . Specifically, I was
now conce rned that if the restrain ing strap broke the
door m ight fly rearwards and strike the e mpennage,
making the aircraft uncontrollable. There was also the
possibility that th e door could injure someone on the
ground if it fell away . In an attempt to circumvent both
of th ese possibili ties I rem oved my leather trousers belt,
passed it through the door handle and knotted it around
the aircraft's scat belt attachment.
' I was now in a position to consider how best to get
the aircraft on to the ground. Whittlesea airst rip was
the closest available; howeve r, I was not familiar with
the airfield, and did not know the radio frequency for
its traffic. Further, Whittlcsea does not have the
emergency services that are a vailable at Moorabbin,
and I was concerned that the disturbance to the airflow
caused by the doo r might create di fficulties in the
A Cessna 172 RG was contracted lo fly two
passengers from an international airport to a large
country town. Arrangements at the airpor t did
not proceed according to plan, with the result that
the pilot became distracted and completed his
preflight inspection in a piecemeal fashion. While
the engine run-up and takeoff were normal, at
400 feet on the climb-out the pilot noticed a high
cylinder head temperature. The pilot then realised
that he had forgotten to remove the engine covers
(inserts into the cowl openings) used to prevent
birds from nesting in the aircraft. He turned back
immediately and effected an uneventful recovery.
As a sequel to this, the pilot concerned has
since taped the engine covers to the pilot head
cover to make them more obvious. The incident
also confirmed the value of a
temperature/pressures check soon after takeoff.
t*
*
*
Aviation Safety Digest would like to thank this pilot for
relating his experience for the benefit of other readers.
Reader contr ibutions are generally well received by
those who read the Digest - most of us can relate to
them. If you believe you ha ve had an incident with a
fl ight safety message for the rest of us , then please send
it in, even t hough you may have already submitted an
air safety incident report •
*
*
*
Shortly after takeoff, smoke became visible in the
cockpit of a Cessna 206. The smoke disappeared
while the aircraft was returning to base . The
engine had just undergone a periodic inspection,
including the replacement of No. 2 cylinder. It
seems probable that a few drops of oil entered the
exhaust heater shroud at that time. •
Aviation Safety Digest 118 I 23
�
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1983
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Text
•'
�Editorial
Australian Civil A ircraft. However, in response to this
demand for more informa tion , th is issu e of the Digest
maintenance
l
[
The Bureau of Air Safety Investigation (BASI) is
responsible fo r the in vestigation of all a ircra ft
accide nts a nd incidents involving civil aircraft
operating within Australian Flight Information
R egions. The fundamental objective of the
investigation of an a ircraft accident or a ir safely
incident is the prevention of accidents and incidents.
It is not the purpose of this activ ity to apportion
blam e or liability. It is important to note that the
Bureau does not exercise a regulatory function , and
that in vestigators have no powers to suspend
licences.
Based on current figu res , there h as been a
con tinuin g decrease in the accident rate ~n ~ustralian
civil avia tion for some years. General av1at1on
activity has increased at a rate of about six per cent
a year, whi le the total accident rate has decreased a t
about live per cent a year. Obviously some of the
effort that is directed towards improving av iation
safety in Australia is effective.
BASI officers investigate about 250 accidents
ann ually. Many of the investigation s are relatively
routine, but nevertheless they continue to provide
important safet y information which contributes ~o t~e
compila tion of a computer-based data bank, which m
turn can be analysed in a varie ty of ways to generate
o r substantia te safet y-related recommendation s.
For some time now there has been c riticism of the
Bureau for not making publicly available more of the
information held on a ircraft accidents. It has been
our policy to use selected accid_e nts. wit_h ac~i dcnt _ .
preven ti on potential as the basis o f articles m Aviation
Safety Digest, and to analyse all acciden ts ~nd provide
stati stical data in the annual Survey of Accidents to
contains a Summary of Aircraft Accident
Information Reports for the first quarter of 1983.
It is intended tha t subsequ ent issues of the Digest
will contain the appropriate quarterly summaries
and, where applicable, update previous reports which
have been fin alised in the current quarter. R eaders
should note that some reports indicate that the
accident is still under investigation. The informa tion
contained in these reports must be considered as
prelimina ry in nature and possibly subj ect to
amendment when the investigation is finalised.
The inclusion of the Summary in the Digest was
considered to be the mosl effective a nd economical
means of conveying the information to the widest
possible audie nce. Yo u will note tha t it has been
designed to be removed without affectin g the pages
of the Digest.
The Summary will be included on a trial basis in
this a nd the following issue of the Digest. Its
continuation beyond that will be largely dependent
on positive reader reaction , so you are in vited to
comment on the u sefulness or otherwise of the
Summary.
You will appreciate that in nearly a ll cases the
published information will be the best and most
current available. I would like to ask therefore that,
wh ere possible , requests for further information be
withheld until at least the fi nal summary for the
particular accide nt h as been published, as the
Bureau's capacity for response could easily be
exceeded if a mass of requests eventu ated.
Finally, I should like to m ention that this issue
m arks the thirtieth a nniversary of the publication of
the Aviation Safety Digest. The Bureau of Air Safety
Invest igation believes that the Digest h as made an
importan t contribution to safety edu cation during
that period. You will have noticed that the Digest is
now being issued regula rl y at its planned quarterly
rate, and it is our firm intention that this will be
mainta ined in the future.
(Paul E. Choquenot)
Director,
Bureau of Air Safety Investigation
Aviation Safety Digest 117 I 3
�9oanaing to on oaaitlont
A typical bounced
landing accident
Landing a light aircraft can demand quite some skill.
Lacking the higher approach speed and inertia of most
RPT machines, light ai rcraft tend to be m ore affected
by such factors as wind gusts and turbulence. The
Bureau of Air Safety Investigation 's files contain many
reports of aircralt damage arising from improper
recovery from a bounced landin g; over the past eight
years there has been an average of one such occurrence
every fortnight. This article discusses bounced landings
in tricycle undercarriage light aircraft , which constitute
th e majority of the reported cases. Typical recent
occurrences include the following:
• T he ai rcraft bounced on touchdown following a full
flap approach. The pilot eased off back pressure on
the control colu mn , causing the a ircraft to pitch
down onto its nose landing gear, which then
collapsed .
• Directional control of the aircraft was lost due to
improper recovery from a slightly bounced landing.
In the ens uing ground loop the right-hand wingtip
struck the ground.
• During a cross-wind la nding a wind gust caused the
air craft to bounce. Improper recovery by the pilot
caused th e propeller to hit the ground.
• An ex-ATPL holder lack ing recent experience on
light aircraft overshot his intended landing poin t and
bounced several times while trying to get the aircraft
to stay on the groµnd . A propeller ground-strike
resulted.
·
Ideally, wh en the correct landing technique is applied
to a light aircraft with a tricycle undercarriage, the
hold-off is sustained to the poin t where the a ircraft is in
a slight tail-down attitude. I t is then permitted to settle
gently on the ground so that touchdown is made on th e
mainwheels first - as intended by the manufacturer .
Because the centre of gravity is forward of the
mainwhee ls the a ircraft will pitch slightly forward a t
touchdown, thereby reducing the a ngle of incidence
(and the lift) of the ma inpla ne, and the a ircraft stays on
the ground. It is when the correct technique is not
observed that problems can arise.
Before discussing the problems of bounced landings
4 I Aviation Safety Digest 117
Final skid
60 metres
\
!:~·/
~·I --
•
~~
~----=---~--~~~~~---'--~--
----------.....
Po int on runway where
nose wheel collapse
appears to have occ urred
Aircraft crosses
threshold 17 knots fa st
airspeed rapidly and then possibly sink at a high rate
causing a heavy lan ding and damage to the
undercarriage and ai rframe.
• Insufficient hold -off or landing before the correct
attitude has been reached. This can lead to
'porpoising' if the nosewheel touches first, or a series
of skips if all three wheels touch together. The
undamped 'porpoise ' can cause severe damage.
F urther, a ground loop may also occur if there is a
loss of directional control .
• Holding off too long and landing with little or no
control over the aircraft a ttitude or rate of descent. If
a hold-off is continued for too long, so that the
airspeed is at or near the stalling speed and the
aircraft is then allowed to balloon or is lifted by an
unexpected gust, the consequent high sink rate
and/or stall may be impossible to control because of
the lack of airspeed. Once again, undercarriage and
propeller damage are likely, while the consequences
of a wing drop during the stall need no elaborat ion.
in detail it is worth sta ting at this point that the best
way to avoid occurrences of this sort is to maintain
your flyi ng skill at a safe level by frequent and p roperly
conducted practice. Otherwise, the best insurance is to
take a check flight with your instructor and ensure your
flying skill is still at a safe level. If you have not been
subject to any official fligh t test s in the previous 24
months you will also be due for a flight rev iew, an d this
can be used to brush up your technique, so helping you
to prevent acciden ts rather than cure th em .
Mislandings: cause and effect
There are four basic causes of mislandings and each is
likely to h ave predictable consequences:
• No roundout or insufficient roundout. The aircraft
will either touch down on the nosewheel or on a ll
three wheels simultaneously . Since the speed will be
high the aircraft will bounce, becomin g airborne
again. Unless corrective action is taken by the pilot
the nose will begin to drop as the airspeed decays a t
the top of the bounce, causing the aircraft to p itch
down heavily onto the nosewheel. If excess flying
speed still exists this motion may be repeated several
times with each oscillation becoming shorter, steeper
a nd less controllable. This mot ion is called
'porpoising' and can cause serious damage to the
undercarriage, propeller and airframe, n ot to
mention the hapless pilot and passengers. Worse,
this oscillatory motion can be aggravated by the p ilot
if his reactions are slow or ill-timed. T h e instinctive
reaction to a bounced landing is to relax back
pressu re or move the control colum n forward to
reduce the height of the bounce. However, if th e
control input is delayed it may not take effect until
the aircraft has already begun to descend, thereby
increasing the rate of descent and steepening the
angle of the already downpitching nose. The result is
an even heavier impact on the nosewheel and
perhaps propeller.
• Roundout too large. The aircraft will balloon, lose
Corrective actions
...
In most cases the best cure is to 'go round' as soon as a
mislanding is recognised. If the landing has initiated a
'porpoise', hold the control column slightly aft of
neutr al and apply full power. This will dampen the
'porpoise' a nd the aircraft will eventually climb away.
Opposing the 'porpoise' pitching action b y use of
elevator almost invariably accentuates the problem .
If circumstances militate against a go-around, e.g. a
d am aged aircraft, bad weather, etc., then a mislanding
can be r ecovered by skilful use of p~wer to reduce the
descent rate and to fly the aircraft into a second flare
and ' hold-off' . However, this technique requires
practice and skill. If not familiar with it you should ask
your instructor to teach you during your next check
flight.
The following pointers , applicable to a ny landing, are
all indicative of a sound fl yin g technique and should be
borne in mind when thinking about this article:
• A gentle flare started early is better than a violent
flare at the last m oment.
• Know the landing attitude of your aircraft
- do not let the aircraft touch down until you
achieve the landing attitude
- do not attempt to hold-off by raising the nose
above the landing attitude
- if you have reached the landing attitude during
the ' hold-off', maintain that attitude with the
elevators and, if necessa ry, control the sink rate
with power un til the a ircraft touches down.
• Pick a point on the runway at which you will 'go
round' if the aircraft has not touched down .
An old definition of a good pilot is one who has an
equal nu mber of takeoffs and landings .. . think about
it! Think about this article too, especially in relation to
your flying technique right throughout the approach
and landing phases; perhaps there may be some points
which wo uld lead to a worthwhile discussion with your
local fl ying instructors on this fu ndamental aspect of
flying . If out of practice or still inexperienced, have
your instructor give you a lesson on recovering from
mislandings, perhaps during your next check flight e
Aviation Safety Digest 117 I 5
�'The pilot continued flight into
weather conditions ...'
Aerobatics and pilot limitations
'The pilot conducted aerobatics at an altitude which was too low to ensure safe recovery.'
Readers of the Aviation Safety Digest will be, unhappily, all too familiar with the type of accident
addressed in this article. Just why VFR pilots continue flight into weather conditions in which they
are unable to maintain the visual references necessary to ensure adequate terrain clearance remains
unclear, for most pilots involved in such accidents do not survive to explain their reasoning.
...
Aerobatic flight is very popular throughout Australia.
Properly executed aerobatics are exhilarating and also
serve as an excellent medium for improving flying skills
and learning to appreciate the capabilities of aircraft.
They are demanding and ma ny ma noeuvres leave the
pilot with little scope for error. It is for this reason that
stringent rules are prescribed. The display at an air
show which draws approving comments from
knowledgeable spectators is the end result, not only of a
skilled and enthusiastic attitude towards flying, but also
of a professional and mature understanding of the
nature a nd demands of aerobatic flight , and of the
safety rules pertaining to it. A local accident
demonstrated - tragically - that to ignore those rules
is to invite disaster.
The pilot h ad been checked and approved to perform
aerobatics down to 1000 feet above ground level
(AGL). A conditi6n 'of the approval was that passengers
were not to be carried. He h ad sought, and received,
permission to carry out an aerobatic display at a 'fly-in'
held at a country town. This display was carried out in
accordance with the pilot's low-level aerobatic approval.
Towa rds the end of the day's activity a television
news team arranged with the pilot to take some air-toair film of the aircraft p erforming. aerobatics. It was
arranged for the television team's h elicopter to fly at
500 feet AGL while filming the sequence. This took
about 10 minutes. Dm·ing the sequence a p assenger was
occupying the front seat of the display aircraft.
Recovery from some of the ma noeuvres was observed
to be below the level of the helicopter , which was
6 I Aviation Safety Digest 117
maintain ing its planned altitude of 500 feet AGL.
When the filming was completed the helicopter
departed; the d isplay aircraft flew to a point about on e
kilometre from the aerodrome and continued
performing aerobatics at a bout 500 feet AGL.
Witnesses observed the aircraft begin a looping
manoe uvre from which it entered a spin to the left.
Recovery was initiated but the aircraft then began to
spin to the right. Rotation then stopped with the
aircraft poin ting vertically downwards. During the
r ecovery from the dive the aircraft struck the ground,
still over 30 degrees n ose down , with the wings level.
*
Comment
It will never be possible to determine all the
contributory factors in this fatal accident. For example,
the unauthorised passenger was also an endorsed
aerobatic pilot - were there competitive peer pressures
acting, directly or indirectly? T h e immediate cause,
however , was spelt out in t he Investigation Report in
one brief clear sentence: 'The pilot con ducted
aerob atics at an altitute which was too low to ensure
safe recovery.' An article in Aviation Safety Digest 102
addressed the topic of 'Aerob atics and structural
limitations'. That article, which is commended to all
practising or would-be aerobatic pilots, includes the
comment that 'No sensible pilot knowingly operates an
aircraft b eyond its structural design limits' . T h e same
standard must also apply to th e individual's piloting
l imits: limits which are unequivocably spell out in
relevant authorisations •
It appears that the 'it-can't-happen-to-me' syndrome
affects many individuals. Anyone who believes it cannot
happ en to h im is advised to consult the index in Aviation
Safety Digest 113 and review some of the occurrences
referenced under the heading of 'Weather'. T he urge to
get to a destination - to 'get through' or 'get-homeitis' - also seems a likely influence on pilots when
making operational decisions. Yet we are rarely, if
ever, in as much of a hurry as we think we are certain ly not at the expense of our lives.
W h atever the reasons, this topic is essential reading
for all pilots, for investigations have shown that a high
experience level , an extensive aviation background and
a conscientious attitude towards flying are no guarantee
against weather-related accidents. It takes only one
hasty or ill-considered decision, regardless of one's
experience, to give the elements a potentially dangerous
edge over your machine, your passengers and you.
For almost all weather-related accidents it is possible
to identify a point, or points, at which the flight should
have been diverted or abandoned. This may come, for
example, in the fo rm of a preflight weather forecast, an
amended inflight forecast or report, or by actually
encountering conditions approaching VMC minima.
Reader s are invited to assess the following account of a
weather-related accident with the objective of
identifying those points and deciding what actions they
would have taken . If they subsequently ever find
themselves faced with a decision of that type, then
p erhaps the careful thought that an analysis of this
accident warrants will help them reach the right
decision in time.
I
....
*
*
A flight by an experienced pilot was planned from Alice
Springs to Adelaide via Leigh Creek. The pilot was
familiar with the route , having flown it often. H e held a
Class Four instrument rating but was not qualified to
fl y in instrument meteorological conditions. H e
attended the Alice Springs briefing office and was
issued with meteorological forecasts which indicated that
weather conditions were expected to deteriorate south of
Leigh Creek. In particular, low stratus was likely over
the Flinders Ranges. Copies of the forecasts issued at
Alice Springs for the section of the flight from Leigh
Creek to Adelaide are reprinted below: Area 51 covers
the firs t half of that section and Area 50 the second
half.
Area 51 forecast issued at Alice Springs
ARFOR 2300 TO 1100 AREA 51
WIND 2000 24020 5000 24025 7000 24025 10000
25030 ZERO 14000 25035
MS05 18500 25040 MS15
CLD SCT ST 1200/1800FT MON TIL 0200 BUT
BKN IN DZ. SCT CU 2500/7000FT
SCT SC 3000/7000FT TEND BKN MON AND IN
D Z V I S 40KM DTRT 4000M D Z 400M FG
WX ISOL FG PATCHES TIL 0100. ISOL DZ TIL
0200 CHIEFLY MON
FZL lOOOOFT
TURB MOD IN CU. MOD BLW 6000FT ON AND
TO LEE MON
Area 50 forecast issued at Alice Springs
AMD ARFOR 2300 TO 1100 AR EA 50
W IND 2000 25030 5000 25030 7000 25035 10000
25040 MS05 14000 25045
MS08 18500 25050 MS18
CLD BKN ST 800/2000FT IN R ASH/DZ. BKN ST
800/2000FT WINDWARD COT/MON BEC SCT
AFTER 0100 AND REDEVELOPI NG AFTER 0900.
SCT CU 2500/8000FT WITH I SOL TOPS 12000FT S
OF 34S. SCT SC 3000/6000FT BKN SC 2000/6000FT
IN DZ AND COT/MON
AMD V I S 40KM DTRT 6KM RASH 1500M XXSH
3000M DZ 400M FG
AMD WX ISOL FG PATCHES TIL 0100. ISOL
RASH TEND SCT COT/MONS 34S.
I SOL XXSH S 35S. ISOL DZ COT/MON
FZL 5000FT IN S R ISING TO 8500FT IN W ICE
OCNL MOD INC ABV FZL
TURB OCNL MOD IN CUF. OCNL MOD BLW
6000FT ON AND TO LEE MON
A delaide TAFOR issued at A lice Springs
COR TAF AMD
AAAD 2304 31018 9999 80RASH 2ST012 4CU020
4SC030 RAPID 0203 23020/ 41
0414 23020/30 9999 80RASH 4CU020 3SC030 INTER
2305 3000 81XXSH 5ST008
11 12 13 11 1012 1010 1009 1009
A VFR flight plan was submitted and the pilot
indicated that if he encountered adverse weather south
of Port Augusta, he would divert to Port Augusta or
Port Pirie . W ith his two passengers the pilot departed
Alice Springs mid-morning in his Piper Seneca and
completed a n uneventful flight to Leigh Creek,
although the weather at Leigh Creek was marginal for
VFR operations.
At Leigh Creek the aircraft was refuelled to capacity
a nd the pilot obtained amended forecasts for Areas 51
a nd 50. These were as follows:
Aviation Safety Digest 117 I 7
�Area 51 forecast issued at Leigh Creek
ARFOR 0500 TO 1400 AREA 51
W IN D 2000 25020 5000 24025 7000 24030 10000
23035 MSOl
14000 25040 MS07 18500 26045 MS19
CLD SCT ST 1500/3000FT ABOUT MON AND IN
PREC IPITATIO N
SCT CU 2500/7000FT SCT SC 3500/6000FT DTRT
BKN SC 2500/6000FT IN DZ AND ABOUT MON
V IS 40KM DTRT 4000M DZ/RASH
WX ISOL DZ MON . ISOL RASH MON S HAW
FZL 9000FT
T U RB MOD CUF AND BLW 6000FT ON AND LEE
MON
Area 50 forecast issued at Leigh Creek
AMD ARFOR 0400 TO 1400 AREA 50
WI ND E OF FRONT
2000 28030 5000 28035 7000 28035 10000 27040 MS06
14000 24040 MSll 18500 24045 MS21
W OF FRONT
2000 25025 5000 25030 7000 25030 10000 24035 MS04
14000 24040 MSl l 18500 24045 MS21
AMD CLD SCT COT ST 1000/2000FT DTRT BKN
ST 1000/2 000FT WINDWARD MON. BKN ST
800/2000FT IN RASH/DZ. SCT C U 2500/8000FT
ISOL TOPS 14000FT S 34S. SC T SC 3000/6000FT
DTRT BKN SC 2000/6000FT IN D Z AND
COT/MON V IS 40KM DTRT 6KM RASH 1500
XXSH , 3000M D Z wx SCT RASH. ISOL XXSH
S 35S, ISOL D Z COT/MON FZL 7000FT ICE MOD
OCNL INC ABV FZL TURB MOD OCNL CUF
AND TO LEE MON
\
PORT PIRIE
Jarr Id P
int
">
Wo d P '"
P • k Po1n
A delaide TAFOR issued at L eigh Creek
W
1
TAF
AAAD 0208 31018 9999 80RASH 2ST012 4CU020
4SC030 RAPID 0203 23020/41
INTER 0205 3000 81XXSH 5ST008 0820 23015 9999
80 RASH 2ST012 4CU020 3SC030 13 12 11 9 1012
1010 101110 11
g Po
~ho W2tor Pont
-
---+
PLANNED TRACK
REVISED TRACK
CRASH SITE
340
Cape El1nb th
R
P me Wnr n
Reef Pot t
B
atr1
Goo e I
R k
nd
8 I Aviation Safety Digest 11 7
...
W hile there were still some 45 minutes before the
area 51 forecas_t became valid, it gave the pilot an
indication of the expected trend. A comparison of the
two sets of forecasts would also have enabled the pilot
to make an assessment of the changes, if any, in the
gener al weather pattern, thus giving him a better
appreciation of en route conditions .
In addition to receiving the amended forecasts at
Leigh Creek, the pilot was also informed that both
Adelaide and Parafield were currently closed to V FR
traffic becau se of adverse weather.
As the pilot taxied for departure at 0419 hours
GMT, there were six oktas of cloud, base 1500 to 2000
feet, over Leigh C reek. T he pilot advised that he
intended cruising below 5000 feet instead of 7 500 fee t
as originally pla nned. He departed at 0424 hours and at
0429 hours acknowledged receipt of an amended
Adelaide terminal forecast giving visibility of 10 km or
greater, rain showers, one okta of cloud at 1000 feet
and six oktas at 2000 feet with visibility intermittently
reduced to 3000 metres with three oktas of cloud at 800
feet.
The flight plan submitted by the pilot at Alice
Springs indicated his intention to track via Quorn,
Wokurna and Ardrossan, but at 0449 hours he advised
that he would be proceeding direct to Por t Augusta and
then to Wokurna. He subsequently reported to
Adelaide Flight Service Unit (FSU) passing a.beam of
Port Augusta at 0515 hours, below 5000 feet, and
advised that he would be tracking to D ublin . No reason
was given for this change of route, but clearly adverse
weather was the cause. Adelaide FSU informed h im
that restr icted area R252 , which is situated south-west
of Port Augusta, was active and he confirmed that he
would be remaining clear of that area. T he pilot of
another aircraft in the area then reported there was a
storm in the Gulf north of Port Pirie, the weather was
clear to the west, and suggested that if the Seneca were
to track via Point Lowly it would have no problems.
This was acknowledged by the Seneca pilot who
responded: 'Thank you very much . I shall do.' He was
then instructed by Adelaide to call Whyalla FSU.
Contact was established at 0523 hours. The pilot did
not, however, reply to any subsequent calls directed to
him.
Following unsuccessful attempts to re -establish
communications with the aircraft, search and rescue
action was commenced. Search action was hampered by
areas of low cloud and reduced visibility associated with
rain and strong winds. The wreckage of the aircraft was
located at 0435 hours on the following day. It was
situated on the eastern side of Mount Remarkable some
300 feet below the 3150 feet summit . At impact the
aircraft had been in essentially level flight on a southwesterly heading. All three persons on board had been
killed.
D etailed examination of the wreckage did not reveal
any defect or malfunction which might have contributed
to the accident.
It was established that at about the time of the
accident, extensive low cloud and rain areas obscured
the ranges in the vici nity of Mount R emarkable.
Comment
T he forecasts obtained by the pilot at Alice Springs
indicated that he would be heading towards an area of
deteriorating weather. This was confirmed b y those
received at Leigh Creek, but the pilot did not express
concern at any stage on receiving this information; nor
did he express any anxiety en route despite the tracking
ch anges he had to make. Perhaps his familiarity with
the area led h im to believe he could find his way
despite the poor conditions. In fact it would appear that
he was not able to navigate adequately by reference to
the ground and eventually tracked to the east of Mount
Remarkable. W hen he turned south-west presumably to track to Point Lowly following the advice
that th e weather was clear there - he obviously was
unaware of the dangerous proximity of Mount
Rem arkable. Uncertain of his position a nd operating in
adverse weather conditions, the p ilot tu rned towards
and flew into the highest ground in the immediate
vicini ty •
Aviation Safety Digest 117 I 9
�Acasual approach
Two different kinds of approach were featu res of this accident to a Beech Bonanza. The first was a
very experienced pilot's rather casual approach to his preflight preparation. The second was an
unorthodox final approach into a difficult landing area. The result was substantial damage to the
aircraft with, fortunately, no injuries to its occupants.
The purpose of the flight was for the pilot and two
passengers to visit a co tton farm on which there were
several landing strips. Seven weeks previo usly the pilot
had operated into the strip he intended using this day.
The three men drove to the aerodrome wher e th e
Bonanza was pa rked and , while the pilot completed his
preflight inspection, one of the passengers telephoned
the manager of the cotton farm to check the weather ,
ensure that everything w as right for the aircraft's
arrival and to adv ise their ETA.
A flight plan was not subm itted because of difficulties
with the local (manual) telephone exchange and becau se
in the past the pilot had occasionally experienced
problems with the aircraft's radios. Further, t he farm
manager was aware of their plans.
On arrival at the farm the pilot overflew the
manager's house a t about 1000 feet AGL to a lert him
to their arrival. He the n flew to the a irstrip , which is
a ligned 085/265 degrees and is a pproxima tely 1050
m etres lon g, to carry out a visua l inspection at 500 feet
AGL.
A s the wind was o nly 2-3 knots fro m the east , the
decis ion was made to land on the 265 str ip to avo id
looking in to the morning sun . The threshold area of
this strip was obstructed by a seven-m etre-high cotton
mod ule m aker (a m achine for making large cotton
bales) to the south , and by four o r five cotton pickers,
each abo ut five m etres high, to the n orth . AU of these
obstructions were with in the str ip b ound ary b u t outside
the central 15-m etre section.
At th e end of the inspectio n run the pilot turned
south to give roo m for a left base . A fter carry ing ou t
the pre-landing checks a nd selecting gear down and full
flap in stages, he approached over th e top of the
obstacles near the eastern threshold. R ealisi ng that he
was too fas t (100 knots) he wen t around . H e clim bed to
about 700 feet AGL, r etracted th e flap bu t left the gear
down and flew a downwind leg.
On the second app roach he decided to fly to the
north of the obstacles and make an S-turn to line up on
the strip after pass ing them . Full flap was again used.
A fter passing the obstacles and turni ng left to in tercept
• \.M.VliiH
'
X.__100M+I~
I
Ill
I
~I
! 1s M
'--~~~~~4-0_0_M~----------~~~=..
~-MOD_U_L~E~~~~~~~~~~~-#,
MAKER
, ... MODULE MAKER
&::;jl
T
7 M HIGH
,
i-
Fl;ghr:::th
Diagram of Flight Path.
(not to scale)
j
l
10 I Aviation Safety Digest 117
I
.#,.~T~,,
PICKERS
_,
the cen tr eline, the pilot started the turn r ight to align
the aircraft with the strip but at that stage realised he
d id not have enough height to turn. H e rolled to the
left to level the wings, at the same time applying full
power. T his d ecision , however, had been left too late.
The aircr aft sank on to the ground, touching initially
abou t 50 metres in front of the module maker and
about 15 d egrees off runway heading. The aircraft
ground looped and skidded backwards, finally coming
to r est about 45 m etres south of the strip centre line, on
a heading o f 115 degrees and with t he engine dislodged
from its mou n tings .
T h e su bsequent investigation revealed significant
d eficiencies in the planning and conduct of this flight.
• Because of the ob stacles parked within its boundaries
th e str ip d id n ot meet the requirements for a private
category Authorised Landing Area. The landing
d istance available, allowing for the obstacles, was
310 m etr es. From the aircraft 's fl ight m anual
performance charts, the landing distance required
fro m a height of 50 feet in nil wind was calculated to
be 500 metres.
• T he decisio n t o fl y an S-turn on short finals to avoid
th e obs tacles was contrary to the r equirem ent that
the last 500 m etres of an approach for landing must
be m ad e in a straight line.
• Insufficien t atten tion was paid to airspeed, probably
because of the demands involved in attempting to
line up the aircraft . T he pilot advised that he did not
n otice th e speed on the final approach, b u t that the
a ircraft a ttitude fel t normal. He stated that he
n ormally approached at about 80 knots, but used the
aircraft flight m a nual to calculate speeds for 'really
sho rt ' str ips . It seem s likely that during the turn
close to the ground, with the pilot applying
considerable back pressure on the control column ,
the an gle of attack increased and the airsp eed
decayed to th e st age where the late application of
power was insufficient to arrest the sink rate.
There is no shortage of lessons in this accident, and
hopefully the exper iences of this pilot can be used as a
teachin g medium for all of us who fly aeroplanes.
Fr om the outset, the wisdom of leaving one of the
passengers - who had no piloting experience - to
make contact with the mana ger at the destination m ust
be questioned. Operations into any AL A should be
conducted with caution, especially if you are unfamiliar
with the area or have not been there for some time. If
someone is available at the area - as they were in this
case - then the pilot should contact them himself to
confirm such variables as the condition of the surface,
obstructions, and alterations to the ALA dimensions.
That conditions can change is amply illustrated by this
accident. In this case, the passenger who did the
telephoning apparently did not raise the question of the
state of the A L A.
Just as the pilot 's approach to preflight preparation
was casual, so too was h is attitude to landing when he
arrived, found that he was faced with a demanding
approach , but decided to press on withou t properly
reassessing the situation. Clea rly it would have been
impractical for him to calculate the ALA dimensions
air borne, but a check of his aircraft's landing data
performance figures, allied to his visual observation of
the obvious encroachment of the machinery on the
available landing length, would have alerted him to the
danger. Had the pilot done this - or indeed
ascer tained the conditions at the ALA himself prior to
departure - then he doubtless would have abandoned
any attempt to land at that particular airstrip.
A final word. T his pilot was offhand in his attitude
towards several types of fundamental safety material,
particularly the aircraft performance data and certain
operational rules. T he temptation to bend the rules is
familiar to all of us . It is, however, a luxury pilots
cannot afford. The r ules have been framed , not to
frustrate u s, but because they are the basis of safe,
sound airmanship. Know those applicable to your
oper ations, and abide by them •
Aviation Safety Digest 117 I 11
�Aircraft accident information
reports
Military firing ranges
FIRST QUARTER 1983
-
Prepared by The Bureau of Air Safety Investigation
The fo ll owing information has been extracted from accident data files maintained by the Bureau of
Air Safety Investigat ion. The intent of pub li shing these reports is to make availab le information on
Australian aircraft accidents from which the reader can gai n an awareness of the circumstances and
cond itions which led to the occurrence .
At the time of pub lication many of the accidents are still under investigation and the information
contained in those reports must be considered as preliminary in nature and possibly subject to
amendment when the investigation is final ised.
Readers should note that the information is provided to promote aviation safety - in no case is it
intended to imply blame or liability.
Note 1: All dates and t im es are local
Note 2: Inju ry classification abbreviations
C =Crew
P = Passengers
0 =Others
F =Fatal
S =Se rious
M = Minor
N =Nil
e.g. C1S, P2M means 1 crew member received serious injury and 2 passengers received m inor
injuries.
The danger of fli ght through active military restricted
areas was highlighted in Aviation Safety Digests 87 and
111. Digest 111 paid particular attention to the ways in
which pilots could avoid this potentially serious breach
of regulations, discussing such aspects as preflight
planning, the currency of en route charts and
documents, and navigational techniques.
Notwithstanding this good advice, breaches are still
occurring and there remains a small group of pilots in
Australia who, probably without realising it, owe a vote
of thanks to the vigilant range safety officer who
commanded a 'Cease Fire ' on sighting an unwitting
and unwanted intruder. Are you one of these recent
transgressors?
• An unidentified aircraft flew through R352 near
Puckapunyal at 1000-1500 feet while firing was in
progress.
• A cream-coloured single-engined Cessna penetrated
R329 near Westernport while the range was active.
• An unidentified single-engined, silver-coloured
aircraft flew th rough R353 at Greytown from east to
west at 2000 feet when line firing of mortar shells
was in progress.
• A single-engined, high-wing aircraft with orange and
yellow stripes on the fuselage fle w through an active
range R524 near Parkes at about 1000 feel.
While these incidents relate to penetration of Army
la nd-based firin g ranges, transgressions have also taken
place through Navy over-water ranges.
Some data on the prime weapons fired by the Army
will be of interest to any pilot planning a flight adjacent
to a military range:
12 I Aviation Safety Digest 117
• 81 mm mortar -
vertical extremity of rounds 5800
feet, maximum rate of fire 10 to 15 rounds per
minute.
• 105 mm howitzer - vertical extremity of rounds
18 OOO feet, maximum rate of fire six rounds per
minute.
• 155 mm howitzer (to come into service in 1983/84)
- vertical extremity of rounds 63 OOO feet,
maximum rate of fire four rounds per minute .
The point here is that, while firing ranges a re
circu mscribed by vert ical as well as horizontal
boundaries, normal ligh t a ircraft operating altitudes are
unlikely to provide any safety 'buffer' if t ra nsitting
below the upper li m it of a restricted area. Further, the
rate of fire can be r apid, incr easing the possibility of a
target being hit - so don' t think it can't happen to
you.
The only certain way to ensure the safety of your
aircraft, yourself and your passengers near active firing
ranges is to avoid them; and this comes back, again, to
thorough and thoughtful preflight planning and
adher ence to correct inflight procedures •
PRELIMINARY REPORTS (The fol low ing accidents are st il l under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
lniuries
Record number
02 Jan
Cessna 310 L VH-EOZ
Non-commercial - pleasure
C1N, P1N
1430
Berwick Sin ., NSW
Noondoo Stn., Old./Berwick Stn., NSW
210023
The pilot was landing uphi ll in heavy rain with a moderate right crosswind. After touchdown on the narrow s trip the aircraft drifted
to the left into soft ground. The pilot used right brake, rudder and nosewheel steering to correct the drift but the aircraft began to
slide and coll ided with a rock.
02 Jan
Piper 28 140 VH-TVH
Non-commercial - pleasure
C1N, P2N
1400
Hoxton Park, NSW
Ban kstown, NSW/Ban kstown, NSW
210013
In calm conditi ons, the pi lot made an approach that was steeper and faster than normal. After floati ng for some distance the
aircraft touched down nosewheel first and commenced to porpoise. The bounces increased in magnitude unt il the nosewheel
tyre burst and the propel ler struck the runway.
03 Jan
Piper 25 235 VH-PIK
Commercial-aerial agriculture/baiting
C1F
1345
Gatton, Old.
Gatton, Old./Gatton, Old.
11 0013
The aircraft had been spraying corn crops on a property adjacent to the pilot's own property. After adding more spray to the
aircraft it returned to spray crops on the pilot 's property. It was seen to fly under a power line, bank right then hit anot her power
line which had been recently installed. The aircraft then struck the ground inverted.
03 Jan
Beech 35 C33 VH-DDC
Non-commercial-pleasure
C1N, P1N
1015
Lismore, NSW
Lismore, NSW/Coffs Harbour, NSW
210033
The pilot elected to return to his departure aerodrome because of deteriorating weather. While manoeuvring to avoid low cloud
and rain in the circuit area, the pilot did not complete his pre-landing checks and landed with the gear up .
03 Jan
Cessna 180 VH-RBE
Non-commercial-practice
C1N
1205
Wagga Wagga, NSW
Wagga Wagga, NSW/Wagga Wagga, NSW
210043
Du ri ng the landing roll the port wing tip scraped the runway and the aircraft came to rest ba lanced on its right wingtip, right wheel
and spinner.
03 Jan
Cessna 172 E VH-DKK
Non-commercial-pleasure
C1 N, P2N
1336
Warrnamboo l, Vic.
Merton, Vic./Warrnamboo l, Vic.
310013
The approach to land was made on Runway 22 in strong gusty westerly wind cond itions. During the hold-off the aircraft began to
drift to the left. The left main wheel brushed the runway and the right wing lifted. As the a ircraft turned left the nose dropped and
the aircraft struck the ground nose first , breaking away the nosewheel and right main wheel.
Aviation Safety Digest 117 I i
�PRELIMINARY REPORTS (The following accidents are still under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
C1N, P5N
Non-commercial-pleasure
04 Jan
Cessna 210 L VH-SMP
Cairns, Old./Lindeman Is., Old.
110023
Lindeman Is., Old.
1505
After checking the wind direction the pilot elected to make an approach towards the south. Severe turbulence on the approach
caused the pilot to go around. After rechecking the windsock the pilot decided to accept a slig ht tailwind and land towards the
north. The aircraft touched down with 700 m remaining and the pilot applied moderate braking. About 155 m from the runway end
harsh braking became necessary. The aircraft did not stop in time and overran the strip.
06 Jan
Cessna 172 N VH-WCW
Non-commercial-pleasure
C1N, P1M, P2N
1240
Northcliffe, WA
Jandakot , WA/Albany, WA
510013
The pilot was unable to locate his desired landing point but found another stri p about 30 km away. He inspected the strip from
about 200 ft agl and carried out a landing. Shortly after touchdown the nosewheel sank and the aircraft overturned. The strip was
under construction and had been recently ploughed.
07 Jan
Rolladen LS 4 VH-llY
Non-commercial-pleasure
C1N
1917
Renmark, SA
Waikerie, SA/Waikerie, SA
410013
The pilot was making a 300 km triangular cross-country flight when he became unsure of his position. After prolonged attempts
to recognise ground features without success, and with evening approaching, he decided to out-land in a paddock. There was a
line of trees at the threshold boundary. On final approach the glider struck the top of a tree and dropped heavily to the ground.
07 Jan
1005
Hughes 269 C VH-PHN
Strathmay Stn., Old.
Commericial-aerial mustering
Strathmay, Old./Strathmay, Old.
C1M, P1M
110033
The engine of the helicopter lost power during cattle mustering. The pilot reduced collective pitch and the engine rpm increased
but application of collective caused a loss of engine rpm again. While crossing trees during an attempted forced landing the main
rotor rpm decayed. The helicopter entered a rapid descent and made a heavy landing.
07 Jan
1300
Bellanca 8 GCBC VH-ADP
Towing gliders
C1N
Tocumwal, NSW
Tocumwal, NSW/Tocumwal, NSW
210053
During the landing roll the pilot was unable to prevent the tall of the aircraft from rising. A small thermal was seen passing at the
same time, and almost immediately afterwards the aircraft overturned.
12 Jan
Cessna R182 VH-SDG
Non-commercial-practice
C1N
1115
Bankstown, NSW
Bankstown, NSW/Bankstown, NSW
210063
The pilot was conducting a refamiliarisation flight on the aircraft. On his first approach the aircraft landed heavily on the
nosewheel while also drifting to the left.
13 Jan
1213
C1N, P4N
210073
Having misjudged his approach the pilot was still 100 ft. high and on the verge of stalling when one-third along the runway. The
pilot said he then lowered the nose and applied some power but was unable to arrest the ensuing high rate of descent before the
aircraft impacted the ground.
13 Jan
1600
Piper 28 140 VH-RSM
Bankstown, NSW
Glasflugel
Club Libelle VH-GVI
Rankin Springs, NSW
Non-commercial-pleasure
Medlow Bath, NSW/Bankstown , NSW
Trial/race/show
Leeton, NSW/Leeton, NSW
C1S
210083
PRELIMINARY REPORTS (The foll owing accidents are sti ll under investigation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Injuries
Record number
20 Jan
C1S
Schemp Cirrus-75 VH-COO Instructional-solo-supervised
210103
1556
Tocumwal, NSW
Tocumwal, NSW/Tocumwal, NSW
The pilot was carrying out his first flight in thi s type of glider. The aircraft was observed to enter a spin, at a low height , at the start
of the downwind leg. The aircraft struck the ground, spinning to the right.
C1N, P3N
21 Jan
Cessna 182 H VH-PLA
Non-commercial - pleasure
110053
1200
Townsville, Old./Dunk Island , Old.
Dunk Island, Old.
The pilot assessed the wind as sout h-easterly, 15-20 knots and joined downwind for Runway 14. As the aircraft was turning onto
final approach one of the passengers took ill. The pilot found a sick bag and passed it to the passenger. By this time the aircraft
was on short final and the pilot noticed that the airspeed was 10 knots high. Full flap had been selected so the pilot closed the
throttle. The aircraft sank rapidly and hit the ground nosewheel first .
Glaser Dirk
C1N
22 Jan
DG 200/17 VH-COJ
Non-commercial-pleasure
210113
Tocumwal , NSW/Tocumwal, NSW
1605
Tocumwal, NSW
Following a spin entered at 6000 ft the pilot was unable to effect recovery. He decided to bail out but excessive " g" loading
prevented him from doing so until the wings separated from the fuselage at about 1700 ft agl. He was then thrown from the
cockpit and parachuted safely to the ground.
23 Jan
C1N , P5N
Piper PA34-200 VH-FSO
Non-commercial - pleasure
1730
Mansfield, Vic.
Sydney, NSW/Mansfield, Vic.
310023
Before commencing his landing approach, the pilot made a low pass to clear sheep from the strip. The sheep ran to one end o f the
field in which the strip was located. On the landing flare the pilot saw four sheep stand up out of grass at the opposi te end of the
field. During the landing roll the four sheep ran across the strip and one was struck by the aircraft's right propeller and main gear.
25 Jan
1410
Cessna 150 G VH-KPO
Canberra, ACT
Inst rue t ional-solo-su pervi sed
C1N
Canberra, ACT/Canberra, ACT
210123
The st ud en t pilot reported that the landing was normal. However, the nosewheel ax le bolt failed. The nose strut th en collapsed
and the aircraft skidded on its nose for 47 m.
26 Jan
0935
C1N
Cessna 152 VH-BUE
Instructional - solo-supervised
Redcliffe, Old./Redcliffe, Old.
110063
Redcliffe, Old.
Following a dual fl ight of five circuit s the student pilot was au thorised for his first solo. The circuit and final approach were
normal. On touchdown the aircraft bounced . The pilot did not take the correct recovery action and following several bounces,
each becoming progressively worse, the nosegear collapsed and the aircraft sl id to a stop.
26 Jan
1105
De Hav 82 A VH-BIN
Serpentine, Vic.
Non-commercial-pleasure
Kyneton , Vic./Serpentine, Vic.
C1N , P1N
310033
The landing was made into a strong westerly wind. The touchdown was normal but towards the end of the landing roll a gust of
wind tipped th e aircraft onto its nose and left wingtip .
C1N , P3N
Piper 32 300 VH-STV
Non-commercial-pleasure
210153
Noorong , NSW
Adelaide, SA/Canberra, ACT
at 8000 ft the engine failed abruptly. Attempts to restart the engine were unsuccess fu l so the pilot carried out a
onto an agricultural st ri p. The nosegear collapsed after the aircraft overran the strip and struck a mound.of dirt.
Because of low thermal activity the pilot decided to make an out-landing. Shortly after touchdown the aircraft encountered a
strong willy-willy which lifted it into the air and moved It violently to the left. The aircraft collided with a tree and fence before
impact with the ground.
28 Jan
1615
Whi le cruis ing
forced landing
17 Jan
Schneider ES60 VH-GPM
Non-commercial - practice
C1S
1730
Beverley, WA
Beverley, WA/Beverley, WA
510023
As he approached the aerodrome from the east, the pilot gained the impression that the wind was light and variable and he
planned to land into the south. Having arrived over the aerodrome at about 450 ft. he noted that the wind was a strong westerly.
He then decided to land downwind but, shortly afterwards, realised this was not possible. While turning to attempt to land into
wind, the aircraft stalled and entered a spin from which it did not recover.
Comme rcial-assoc. agricul ture/baiting
C1 F
29 Jan
Piper 36 375 VH-TKZ
" Boree" prop., NSW/" Boorambi" prop., NSW 210133
1145
Carrathoo l, NSW
While tracking between the next area to be fertilised and the destination, the aircraft was seen to col lide with a tower about 44 m
high, apparently without avoiding action being initiated.
Non-commercial - pleasure
C1N
19 Jan
Glasflugel Libelle VH-GJG
Leeton, NSW/Leeton, NSW
210093
1450
Leeton., NSW
Several gliders were approaching the start gate during a championship event. One was overtaking another from below at about
3400 ft when the two collided. One, though damaged, was able to land safely. The pilot of the second parachuted onto the airfield,
landing about 150 m from the wreckage of his aircaft.
C1N, P1N
29 Jan
De Hav C1 TMKIO VH-UPD Non-commercial-pleasure
410023
2030
Point Gawler, SA
Two Wells, SA/Two Wells, SA
After takeoff , at approximately 300 ft , the aircraft developed a rough-running engine. As the area ahead was unsuitable for a
landing the pilot elected to make a 180 deg turn before attempting a precautionary landing. During the turn an excessive sink rate
developed and the aircraft hit the ground heavily during the landing flare.
31 Jan
1930
Rockwell 114 VH-SCM
Wanaaring , NSW
Non-commercial - pleasure
Grif fith , NSW/Wanaaring, NSW
C1N , P1N
210143
19 Jan
Szybowcowy Foka-5 VH-GZW Non-commercial-pleasure
C1N
210093
Leeton, NSW
Leaton, NSW/Leeton, NSW
1450
Several gliders were approaching the start gate during a championship event. One was overtaking another from below at about
3400 ft when the two collided. One, though damaged, was able to land safely. The pilot of the second parachuted onto the airfield,
landing about 150 m from the wreckage of his aircraft.
While flaring to land on a roadway used as a stri p the aircraft suddenly drifted sideways. Full power and some bank were applied
in an attempt to go-around but the propeller struck a smal l tree. The aircraft struck the ground, collapsing th e gear, and hit several
more trees before coming to rest.
Non-commercial - aerial mustering
C1F
20 Jan
Cessna 172 N VH -INH
110043
0626
Thylungra Stn ., Old.
Thylungra, Old./Thylungra, Old.
On the evening preceding the accident the pilot indicated his intention to com mence mustering early the next morning. The pilot
arose at abo ut 0530 ho urs and it is believed that the aircraft took off at about 0600. The aircraft was seen at about 0620 by two
stockmen. It was flying at about 100 ft agl and, when the engine noise ceased and the aircraft was not seen again, one stockman
rode to a nearby bore and found the inverted aircraft wreckage.
01 Feb
Cessna A188B A1 VH-EVO Commercial-aerial agriculture/baiting
C1N
11 0073
Weimbi Downs Stn.
Weimbi Down s Stn ./Weimbi Downs Sin .
0800
Th e pilot was conducting spraying operation s from a landing area with two strips. He had been bri efed about a power line across
the western end of the sho rt cross strip . During the fourth approach for landing on that st ri p the landing gear struc k t he power
line, the aircraft decelerat ed rapidly and landed heavily on the main wheel s. The right mainwheel broke free and the aircraft slid to
a hall.
ii I Aviation Safety Digest 11 7
Aviation Safety Digest 117 I iii
�PRELIMINARY REPORTS (The following accidents are sti ll under investigation)
PRELIMINARY REPORTS (The fol lowing accidents are still under invest igation)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
Date
Time
Injuries
Record number
Cessna A 188B A 1
Goondiwindi
VH-UWH
Commercial-aerial agricu lt ure/baiting
Goondiwindi, Old./Bogabilla, NSW
C1 N
210163
During the takeoff roll, at about 40 kt, a propeller blade detached from t he hub. The aircraft slewed uncon trol lably, col lapsing the
left-hand undercarriage.
Instruct ional -solo
C1N
03 Feb
Enstrom F28 C VH-IYP
Hoxton Park, NSW/Castle H ill, NSW
210173
Castle Hill, NSW
1259
The helicop ter was approaching the hover over the helipad at abo ut 20 ft. It suddenly yawed to the right and continued throug h
several level 360 deg turns. The pilot was unable to stop this turning motion and the helicopter landed heavily, sti ll rotating to th e
right.
1
j
C2S
Romainian IS·28B2 VH·COE Instructional- Dual
05 Feb
Camden, NSW
Camden, NSW/Camden , NSW
210183
1308
Shortly after takeoff, at a height of approximately 300 ft , the glider was seen to release from the tow lin e. An immed iate right turn
was initiated accompanied by a nose-up pitch change. The glider then stal led, entered a sp in and struck the ground at a high rate
of descent.
z
Cessna 150 M
Urawa, WA
VH-WWM
Non-commercial-aerial mustering
Urawa Homestead, WA/Urawa Hmstd, WA
Blanik L13 VH·G IK
Lake Keepit , NSW
Instructional-solo-supervised
Lake Keepit, NSW/Lake Keepit, NSW
21 Feb
1520
Conaero LA4 200
Renmark, SA
21 Feb
1204
Burkhart Twin Ast ir
Waikerie, SA
24 Feb
1130
VH-BDK
VH-IKB Instructional - check
Waikerie, SA/Waikerie, SA
C2S
410033
Cessna 150 G VH-RNJ
Canberra, ACT
Instructional - Dual
Canberra, ACT/Canberra, ACT
C2S
210233
Cessna 402 VH-DI L
Nagoorin, Old.
Charter- Cargo
Br isbane , Old./Gladstone, Old.
C1F
110153
Piper 28 R200 VH-SWB
Pamatta Sin., SA
Non-commercial -bus iness
Panatta, SA/Orroroo, SA
C1N, P3N
410053
The takeoff was made from a 650 m long strip. Early in the takeoff run the pi lot tried to l ift the nosewheel off the st rip but reduced
back pressure when the stall warn ing light flashed on. Approach ing the end of the strip t he ai rcraft became airborne and to
faci litate acce leration, the pilot retracted the landing gear. The aircraft then sett led back onto the strip and came to rest after a
100 m slide.
C1N, P1N
10 Feb
Cessna 172 N VH-TDH
Non-commercial - pleasure
110093
Maryborough, Old./Fraser Is land , Old.
0700
Fraser Island, Old .
Following a low pass along the intended landing area, full throttle was applied to commence an overshoot. The pilot stated that
the engine fai led to respond and the aircraft co llided with trees 100 m beyond the end of the strip.
iv I Aviation Safety Digest 117
C1N , P1N
110143
After making a posit ion report no further communications were rece ived from the aircraft. The wreckage was located after two
days' search. The aircraft had struck th e ground in hilly count ry in a near vertical atti t ude.
Charter- passenger
C1N, P3N
09 Feb
Cessna 172 G VH -SHV
Maryborough , Old./Happy Val ley, Old.
110083
1030
Maryborough, Old.
The pilot abandoned the takeoff short ly after becoming airborn e. The aircraft was landed back on the runway but failed to stop
before collidin g with the aerodrome bo undary fence.
14 Feb
Non-commercial-pleasure
C1N
Cessna 180 D VH-GCW
210203
Bankstown, NSW/Gulgong, NSW
1514
Bankstown, NSW
Dur ing the takeoff run the pi lot's seat-bac k co llapsed. The pi lot fell backwards, los ing cont rol of the ai rcraft, which subseq uently
ground-looped s harp ly to the left .
Non-commercial - pleasure
Gunpowder, Old./Buckingham Downs, Old.
Du ring the landing ro ll on a disused strip, the right main wheel struck a ridge of dirt located on t he side of a road that crosses the
strip. The resultant damage was not d iscovered until completion of the subsequent flight.
22 Feb
0430
At about 50 ft, after takeoff on aero-tow, the tug and glider enco untered a thermal. The glider was thrown upwards and to the side
and the pilot released . The subsequent forced landing was off t he edge of the strip.
Inst ructional-solo-supervised
14 Feb
Beech C23 VH-UML
C1N
Archerfield, Old ./Arc herfield , Old.
110113
Archerfield, Old.
11 07
On the third bo unce of the landing attempt the propeller st ruck the ground and the undercarriage noseleg collapsed. The aircraft
slid along the runway for 270 m from the first point of touchdown before com ing to rest.
Piper 28 R200 VH·CJV
Buckingham Downs, Old.
During the pre·takeoff checks the student found the carburettor heat control cou ld be pul led out further than usual and that t here
was no rpm drop associated with the app licat ion of hot air. On takeoff the aircraft was s low to acce lerate. It became airborne and
was observed to enter a gentle r ight turn. A wing dropped and the aircraft impacted the ground.
C1N
210193
Co mmercial-aerial agricu lt ure/baiting
C1M
12 Feb
Piper 36-285 VH-BRV
Tully, Old./Tully, Old .
110103
0900
Tully, Old.
After refuelling his aircraft from drum stocks, the pi lot started the engine and taxied to the end o f the strip. Takeoff was
commenced and at about 100 ft agl the engine ran roughly and then stopped. Attempt s to restart the engi ne were unsuccessfu l
and the aircraft co llided with trees.
21 Feb
1003
22 Feb
0736
C1F, P1F
510053
Non-commercial - pleasure
C1N, P3N
12 Feb
Cessna 182 0 VH-A IV
Moorabbin, Vic ./Ardlethan, NSW
210213
0830
Ardlethan, NSW
The pi lot flew several passes to c lear sheep from the strip. When no sheep were vis ible an approach and land ing were carried out.
As the aircraft touched down a sheep ran across the strip from the right. The pilot steered the aircraft to the left and it ran off the
strip into rough ground.
C1N, P2N
18 Feb
Demonstration
Beech 58 VH-FIV
110133
Archerfie ld , Old./Archerfie ld , Old.
0900
Nth. Stradbroke Is., Old.
In order to illustrate t he high cru isin g speed of the aircraft to a potential customer, the pi lot elect ed to fly along a beach at a low
level. The aircraft flew into a flock of birds which rose from t he beach as t he aircraft approached.
After lift-off on an aero tow the glider entered an uncontrol led cl imb, efforts to correct the cl imb with elevator were unsuccessful.
The g lider pi lot released the tow rope and the glider cont inued to climb until it stalled . The glider turned left, entered a dive and
struck the ground.
After completing an aerial spotting task the aircraft was observed to c limb above 1000 ft and depart on what was thou ght to be a
windm il l inspection flight. When the aircraft failed to return search procedures were instituted. The wreckage was located by a
searching aircraft shortly after f irst light on the following day.
06 Feb
1710
Injuries
Record number
Charter- passenger
C1N, P3N
410043
Renmark, SA/Goolwa, SA
At 50 ft after takeoff the aircraft failed to continue to cl imb, t he airspeed decayed and t he aircraft began to lose height. To avoid
trees ahead the pilot tu rned the aircraft. The right float st ruck the water, the ai rcraft yawed to the r ight and skipped sideways to
the left across the water before com ing to rest.
Instructional-solo-supervised
C1N
04 Feb
Piper 28 151 VH·PZM
510043
0900
Wagin, WA
Wagin , WA/Wagin , WA
The pilot was practising circuits and land ings in strong cross-wind conditions. Short ly after touc hdown on t he first solo circu it of
the period directional control was lost and the aircraft ran off the side of the st rip. The nosegear collapsed when the aircraft
struck an embankment.
05 Feb
Kind of flying
Departure point/Destination
14 Feb
Cessna 180 VH-BDN
Instructional - training
C2N
210223
1430
Goulburn , NSW
Goulburn, NSW/Goulburn, NSW
The pilots were engaged on t he second o f two periods of circu it and landi ng pract ice. Towards the end of the twel fth landing, the
aircraft ground-looped to the left and the starboard wingtip and tailplane con tacted the ground.
Commercial-aerial agriculture/baiting
C1N
02 Feb
Piper 25 235 VH-BMF
510033
Bunbury, WA/Donnybrook, WA
Donnybrook, WA
0815
After a low pass to clear cattle, the pilot landed on an airstrip situated on the side of a hil l. As the aircraft rol led onto a flat port ion
of the strip t he pilot was alarmed to see that cattle were again on the airstrip. He applied heavy braking and the aircraft nosed over
onto its back.
02 Feb
2000
Aircraft type & registration
Location
25 Feb
0830
C1S, P2S
510063
While establ ished in cruising fl ight the pi lot felt someth in g strike the airframe, and noti ced t hat a pi llow supporting an extern al
litter patient had been dislodged. About one minute later the helicopter began to yaw to the right with increasing speed. The pilot
entered auto-rot ation, aim ing for a run-on land ing in a smal l clearing . However, as collective pitch was reintrod uced control was
lost , the aircraft struck the ground heavily and was destroyed.
1
1}
Bell 47·G381 VH·CSI
Gl en Hills Yard, WA
Charter-aerial ambu lance
Glenn Hills Yard, WA/Camp Nicholas, WA
26 Feb
Cessna 172 N VH-DDV
Non-commercial- practice
C1N
1800
Bourke, NSW
Bourke, NSW/ Bourke, NSW
210243
The pilot was carry ing out the fourth land ing in a series of pract ice c ircuits . Following a reported ly normal f lare and to uchdow n
the aircraft bounced several times before coming to rest on the runway. The damage to t he ai rcraft was discovered after the pi lot
had tax ied to the termi nal area.
27 Feb
1346
Boe ing 727 276
Adelaide, SA
VH ·TBI
Schedu led Domestic Passenger Se rv ice
Adelaide, SA/Melbourne, Vic.
C3N, P123N
410061
The airc raft was using a taxiway which had a row of cones positioned abou t 11.5 m from the cent re-line to ind icate a step in the
sealed su rface. The pilot saw a fuel tanker parked some d istance away from t he cones. Assum ing that the co nes were taxiway
clearance markers, he continued to tax i along the centre-line. The port wing st ruck the top of the tanker about 15 m from the
aircraft centre-lin e and about two metres from the win gtip.
27 Feb
2055
Cessna 172 F VH·DOX
Witchel lina, SA
Non-commercial- aerial musterin g
Witchellina, SA/Witchellina, SA
C1 N, P2N
410073
The pi lot flared t he airc raft for landing but then decided he was undershootin g and app lied f ul l power to go around. The ai rc raft
cl imbed to about 7 ft when the left wing dropped and struck the ground. The ai rcraft yawed sharply to the left and the nose st ruck
the gro und heavily.
Aviation Safety Digest 117 I v
�PRELIMINARY REPORTS (The fo llow in g accident s are still under investigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure poin t/Destination
Injuries
Record number
Charter- passenger
C1N, P7N
02 Mar
Cessna 421 VH-MOZ
410083
1139
Daralingie, SA
Adelaide, SA/Daralingie, SA
After touchdown the pilot veered the aircraft to the right side of the strip to avoid another aircraft parked near the left side. The
right main gear encou ntered soft soil and th e aircraft began to swing further right. The pilot corrected with left brake and rudder
but the nosewheel dug into the soft surface and the nosegear supports were broken.
Non-commercial-practice
C1M, P1S
02 Mar
Victa 115 VH-CAP
510073
Mundijong, WA
Jandakot, WA/Jandakot, WA
1450
On completion of a pract ice forced landing the pi lot opened th e throttle to go-around. The engine produced only partial power
and the aircraft touched down in a paddock. After se lecting carburettor heat to co ld the engine developed fu ll power but because
of the extremely rough surface of the paddock the aircraft did not acce lerate beyond 60 kt. The aircraft became airborne bu t
co llided with trees on the paddock boundary and crashed to the ground .
03 Mar
Beech C23 VH-UMF
Inst ructional-solo-supervised
C1N
1424
Goulburn, NSW
Bankstown, NSW/Goulburn, NSW
210263
The pilot, on his first so lo navigation exerc ise, was landing with a moderate right crosswind. During the landing t he pilot thought
t hat he had made a very smooth touchdown and released cont rol column back pressure. The aircraft then landed heavily on the
nosewheel which collapsed .
03 Mar
Cessna P206 B VH-DVT
Non-commercial-business
C1N
210253
Camden, NSW/Portland, NSW
1010
Portland , NSW
On final approac h to t he 780 m long strip the pilot observed sheep on the strip near the th reshold. He decided to land beyond that
area but the aircraft did not touch down until only 320 m remained . The pilot continued with the landing and att~mpted to ground·
loop the aircraft. It did not respond and ran through a fence at low speed.
Non-commercial-pleasu re
C1N,0 1N
04 Mar
Pilatu s B-4 VH-GID
510083
Cuballing, WA
Cuballing, WA/Cuball ing, WA
1658
Durin g an aero-tow laun ch, the engine of the tug aircraft failed before it became airborne. The pi lot of the glider released the tow,
attempted to stop the glider but was un able to avoid a coll ision w ith the tug .
04 Mar
Piper 25 235/A6 VH-TUG
Towing gliders
C1N, 01N
510083
Cuballing, WA/Cuballing, WA
1658
Cuball ing, WA
During an aero-tow launch, the engine of t he tug aircraft failed before it became airborne. The pilot of the g lider released the tow,
att empt ed to sto p the glider but was unable to avo id a coll i sio n with the tug .
05 Mar
Trial/race/show
C1N
De Hav 82 VH-ADW
210273
1645
Maitland , NSW
Maitland, NSW/Maitland, NSW
Three DH82 aircraft competing in a formation flying competition were making a V format ion landing with a moderate left
crosswind. After touchdown the aircraft on t he left side of the leader was affected by a gust , it swerved to the right and co llided
with the aircraft in No. 2 position.
Trial/race/show
C1N
05 Mar
De Hav 82 VH·RNI
210273
Mait land , NSW
Maitland, NSW/Mai tland, NSW
1645
Three DH82 ai rcraft competi ng in a format ion flying competition were making a V formation land ing with a moderate left
crosswind. After touchdown th e aircraft on the left side of the leader was affected by a g ust , it swerved to the right and col lided
with the aircraft in No. 2 position.
C1N
Commercial - aerial musterin g
06 Mar
Piper 18 150 VH-SBO
11 0163
Galway D. St n., Old./Galway D. Stn., Old.
Galway Downs, Old.
1230
The pilot misjudged his approach to a claypan landing area and decided to go around. The throttle was advanced bu t the engine
failed to respond and the pilo t was fo rced to land. As an over-run seemed probable the pilot ground-looped the aircraft.
C1N , P5N
06 Mar
Cessna 185 A VH-U PI
Sport parachute jump
Meredith, Vic ./Meredith, Vic.
310053
1045
Meredith, Vic .
The strip was aligned 140 deg and the wind was about 5 kl from 045 deg. On takeoff the aircraft yawed left then right and ran off
the side of the strip. It became airborne just short of the bo undary but the tail struck the fence and the tail wheel broke off. After
despatching four parachutists at the planned height the fifth parachutist who was the aircraft owner landed the aircraft, holding
the tail off the gro und. Just before it stopped the aircraft tipped forward onto its nose.
PRELIMINARY REPORTS (The fo llow ing accidents are stil l under investigat ion)
Date
Time
Aircraft type & registration
Location
Kind of flying
Departure point/Destination
10 Mar
Beech A36 VH-BKM
Non-commerc ial-pleasure
C1N
0850
Archerfield , Old.
Caloundra, Old./Archerfield, Old.
110183
Fo llowing a normal touchdown the landing gear partially retracted when the pilot inadvertently se lected gear up ins1ead of flaps
up.
10 Mar
Transav PL 12 VH -SUO
Commercial - aeri al agriculture-baiting
C1 M
1800
Brun swick Jun
Agr icultural stri p/Agricu ltu ral strip
510093
The pilot decided to change fuel tank se lection during t he pre-takeoff checks. While the aircraft was being reloaded, the pilot was
distracted by an un serviceability on a second aircraft and omi tt ed to alter the fuel tank selec tion . Short ly after the aircraft became
airborne, there was a complete loss of engin e power and the pilot was required to carry out a forced landin g on unsuitable terrain.
12 Mar
1200
Schleicher KA-6
Gin Gin, Old.
12 Mar
0528
Beech 58 VH-CTU
Hampshire, Tas.
VH-GNA
Trial/race/show
C1N
110193
Bundaberg, Old./Mundubbera, Old.
The pilot was attempting a Gold Distance cross-coun try exercise. Al though the cloud base at the start was lower than optimum
t he pilot elected to proceed as planned. While searching for t hermals and waiting for the cloud base to rise, height was lost. An
outland ing on a golf course was necessary. During the landing roll the left wing struck a small bush which was growing around a
tree stump.
Non-commercial-aerial ambulance
C1F
Devenport, Tas./Wynyard, Tas.
310073
The pilot was called out at about 0400 hours local time for an urgent medical fli ght from Wynyard to Melbourne. This required
posi tioning the aircraft from its base at Devenport to Wynyard. The takeoff from Devenport was made in darkness wi th an
overcast sky and light drizzle. The aircraft then apparently continued on the takeoff heading at high power and low level until it
struck the ground at high speed in a forest area 25 km south of Wynyard and 56 km from Devenport.
12 Mar
1720
Piper 32 300 VH-PWI
Non-commercial-pleasure
C1 N, P2N
Walpole, WA
Wagin, WA/Walpole, WA
510103
Following a heavy landing the aircraft bounced several times, w ith the bo unces increasi ng in magni tude. The pilot made a go·
aro und and noticed a wheel spat on the run way during th e seco nd approach. A smooth touch -down was made and the nose held
up as lo ng as possible. When th e nose was lowered the nosegear fo lded and the propel ler struck the ground.
16 Mar
1922
Cessna 172 N VH-MNW
Non-commercial-pleasure
C1N, P1N
Nullarbor, SA
Esperance, WA/Nullarbor, SA
410093
Concerned about the fuel remaining the pilot hurriedly joined the circu it area. When he found the ap proach obstructed he
tig htened the tu rn to land on th e cross strip. During the turn th e engine stopped. Unable to glide to the stri p the pilot att empted to
turn the aircraft into wind. The righ t mainwheel struck the ground followed by the nosewheel which collapsed , and the aircraft
overturned before coming to rest.
18 Mar
1820
Grumman GA 7 VH-JSK
Nambucca Rvr., NSW
No n-commercial- pleas ure
Nambucca Rvr., NSW/Port Macquarie, NSW
19 Mar
Beech A60 VH-DUK
Charter- passe nger
C1 N
0515
Port Macquarie, NSW
Port Macquarie, NSW/Sydney, NSW
210293
During the takeoff roll the pilot noticed some kangaroos bounding toward s the aircraft. During the attempted avoid ing
manoeuvres the aircraft ran off the side of the strip and struck a drain.
19 Mar
0832
Piper 23 160 VH-DBF
Schof ields, NSW
Non-commercial-p leasure
C1 N
Camd en, NSW/Schofields, NSW
210303
The airc raft was cross ing the threshold , abo ut 300 m behind an Iroquo is helicopter, w hen the right wing dropped. The nose also
dropped and the nosewheel contacted t he runway heavily and was broken o ff. The aircraft slid along the runway for some 200 m
on its no se before coming to rest.
19 Mar
1112
Rutan Vari EZE VH-EZI
Trial/race/show
C1N
Schofields, NSW/Schofields, NSW
210313
Schofields, NSW
Just before touchdown the aircraft encountered wake turbulence from a preceding landing aircraft. The pilot applied full power
and attempted a go-arou nd, but the aircraft contacted the runway heavily and the nosegear collapsed.
20 Mar
1145
Cessna 21 0 L
Gooiwa, SA
VH-FOC
Non-commercial - pleasure
Mt. Gambler, SA/Goolwa, SA
Commercial -aerial agric ul ture-bai tin g
C1N
Cessna T1 88C VH -M OT
Tan sey, Old./Tan sey, Old.
11 0173
Tansey , Old.
engaged in s praying two paddocks, separated by a third . Whi le flying over the intervening paddock the pilot' s
diverted by looking at the next area to be sprayed. The aircraft struc k and broke a three-s trand power line. A
landing was made straig ht ahead in a flat paddock but the aircraft overran it and collided with two fences and a
24 Mar
1545
Cessna 182 P
Portland , Vic.
VH-MIG
Non-commerc ial -pl eas ure
Portland, Vic ./Portland , Vi c.
vi I Aviation Safety Digest 117
C1M, P3N
210283
The aircraft failed to accelerate normally during takeoff from a wet and boggy strip. Al thoug h the aircraft became airborne near
the end of the strip, flying speed could not be maintained and the aircraft ditched in to a nearby river.
Non-commercial - pleasure
C1N, P1N
Cessna 182 K VH-KRI
07 Mar
310063
Couta Rocks , Tas.
Smi thto n, Tas./Couta Rocks, Tas.
0900
Alter landing the pilot taxied the aircraft along a track leading to a parking area. Nearing the parking area the nosewheel entered a
wombat hol e, pushing back the nose s trut and buckli ng the firewall.
09 Mar
0945
Th e pil ot was
att ention was
precau tionary
d itc h.
Injuries
Record number
C1N, P2M, P3N
410103
Alter crossing some trees o n the approach path the pilot reduced power to land. The aircraft landed heavi ly and bounced several
times. The pilot increased power to go around but t he aircraft , which had lost its nosewheel , slid to a halt.
C1N, P1N
310083
The aircraft had been parked in the open fo r several days during which 10 cm of rain fel l. The pi lot drained water from the wing
tank and main filt er drain s but twi ce o n start-up and taxi the engine ran roughly and further water was drained from the fu el
system . On the thi rd start th e engine ran up satisfactorily. The pil ot made a normal takeoff but th e engine failed at about 300 ft. In
t he ensuing forced landing the aircraft touched down heavily and th e nosegear collapsed .
Aviation Safety Digest 117 I vii
�PRELIMINARY REPORTS (The f ollow ing accidents are still und er investigat ion)
Date
Time
Aircraft type & regis tration
Location
Kind of flying
Departure point/Des tin a tion
Injuries
Rec ord number
24 Mar
Cessna 150 L VH-PQX
Non-commercial-aerial mustering
C1S
Warambie, WA/Warambie, WA
510113
1000
Warambie, WA
After locating some cattle for a musteri ng party the pilot flew along a creek line at about 400 ft agl and 60 kt with 10 deg ree of flap.
To keep the ground party in sight the pilot commenced a left turn and the aircraft stalled. The pilot was unab le to regain control of
the aircraft before it hi t the ground.
26 Mar
1722
Non-commercial-pleasure
Bathurst, NSW/Canberra, ACT
Cessna 210 B VH-DBU
Canberra, ACT
C1N, P1N
210323
On takeoff a loud bang was heard when the landing gear was selected up. On arrival at his destination the pilot attempted to lower
the landing gear using both the normal and emergency systems. However, his efforts were in vain. As the ai rc raft touched down
the main wheels collapsed and the aircraft came to a stop after sliding 140 m.
26 Mar
1045
Commercial- ma pp i ng/photo/su rvey
Ei ldon, Vic./Eildon, Vic.
Bell 206 B VH-BLP
Lake Eildon, Vic.
Pitts 82 A VH-WEB
Wallacia, NSW
Non-commercial-pleasure
Wallacia, NSW/Wallacia, NSW
C1M
210333
After initial touchdown the aircraft bounced several t imes and the pilot initiated a go-around. During a very shallow climb away
the aircraft struck a power cable and cartwheeled to the ground.
29 Mar
1442
Cessna 180 VH-BDN
Moorabbin, Vic.
Non-commercial-pleasure
Goulburn, NSW/Moorabbin, Vic.
C1 N
310103
The landi ng was made on Runway 31C with a light surface wind from about 280 deg. The pilot corrected for right drift on t he
approach and the aircraft touched down on the main wheels. As the tai l settled d uring the landing roll there was a sudden wind
c hange to 200 deg, gusting from 5 to 11 kt and the aircraft swung sharply to the left. The righ t wing con tacted the runway and t he
aircraft nosed over onto its back.
FINAL UPDATES
Date
Pi lot licence
Record number
Age
Hours total
Hours on type
Rat ing
02 Jan
Private restricted
210013
21
64
11
None
The pilot had been required to divert due to a thunderstorm over his destination. He did not in itiate a go-around w hen
circumstances indicated that this was the correct course of action.
03Jan
Private
210033
42
410
215
Inst ru ment rating Class 4
The gear warning horn was serviceable, however, during the land ing approac h and flare the pilot had not reduced his t hrottle
setting to the po int where the h orn would be act ivated .
21 Feb
Private
110143
35
viii I Aviation Safety Digest 117
650
Not known
Reflections on an accident
Recently a light twin-engine aircraft crashed while commencing a charter flight. Although the
accident seemed fairly simple, many factors were involved. To help identify the causes of the
accident and thus draw lessons affecting Company policy, the Chief Pilot wrote a report which was
also submitted to the Bureau of Air Safety Investigation. This report - slightly amended by the
author for publication - is printed below.
C1N , P1M , P2N
310093
During a low-level photograph ic flight, the pilot made a shallow left turn at about 400 ft agl and a low forward speed. When he
increased the rate of turn, the helicopter began a rapid turn to the right and the nose pitched up. The rotation continued for 3 to 4
turns duri ng which the nose pitched up and down. The pilot had almost regai ned control when t he helicopter s truck the g round
heavily on its skids and rolled onto its right side.
27 Mar
1510
Pda
None
D uring the takeoff roll at a remote bush airstrip , the
pilo t lost control of a light twin operated by my
Company. T he a ircraft took off prematurely, stalled,
en tered an incipien t spin to the righ t and crashed.
D amage to the air craft was extensive, although luckily
neither th e pilot nor the passe ngers suffered inj ury.
M any fac tors were involved in the accident a nd are
noted belo w.
and has poor traction is not easy - but nor need it be
dangerous.
It would seem to me that conditions were such on the
day of the accident that for an experienced and careful
pilot using the correct techniques the operation could
have been safely carried out.
The aircraft
The airstrip and conditions
The a irstrip is located on a slight rise; although there
a re a few hills nearby, the approaches are good and
m ost of the su rrounding terrain is low-lying and level.
T he nearest occup ied settlement is a bout ten miles away
by a very rough track.
Under m ost conditio ns the length and width of this
particular a irstrip are more than adequate for the
Compan y' s aircraft. The main problem is the surface
dra inage - when wet the grass becomes··slippery and in
places the ground becom es boggy .
As there is n ormally no one at the a irstrip to report
on condit ion , th is inform ation is usually obtained
through aerial inspection , combined with the pilot's
(and the Compan y ' s) knowledge of the strip and recent
weather. If the pilot decides to land, he/ she can then
car ry o ut a further inspection to determine whether a
takeoff would be safe , a nd if so what technique should
be used . This is gen erally done while taxiing after
landing . If any doubt remains an inspection on foot is
m ade . A pparently this did not happen ; the choice not
to takeoff probably was not con sidered , while takeoff
techniq ue also su ffered a similar fate .
At the ti me of the accident there were people working
near the a irstrip who could have been contacted prior to
the flight , but a strip condition report was neither
requested nor given.
Weather conditions were an unstable airmass with
u nsteady and gen erally ligh t win ds. There had been
considerable rain in the preceding period. Although
strong wind gusts were later cited by some unofficial
sources, this is u n likely . In my opinion' wind was not a
determi ning factor in the accident; rather it was
brought up afterwards as a plausible 'cause ' .
I a lso doubt tha t the boggy surface was the
determ ining facto r - although it certainly was
impo rtan t both in m aking directional control a little
trickier and in retarding acceleration . A takeoff from a
sur face su ch as muddy grass or loose sand which is soft
The aircraft used was a fully serviceable IFR twin . This
aircraft was not as suitable for bush work as, for
example, a Cessna 206 or a BN-2 Islander.
However, when a customer is prepared to pay for
one's most expensive aircraft and one has financial
problems, one is not inclined to argue, much less pass
the job on to a competitor. As Chief P ilot, I considered
that the operation of that aircraft to the airstrip
concerned was not unsafe - if it had been, the ALA
R egister kept by the Company would have noted
restrictions on operations.
I must state that in this Company the importance of
operational requirements is recognised. Safety is of
course far more important than a few dollars; it is
better to go b1-oke safely than to lose the plane, pilot
and passengers in one easy crash.
The point is that the use of that pa rticular aircraft for
that work and in those conditions was not unsafe in and
of itself. But again, it did dictate careful handling and a
high level of pilotage skill .
The pilot
T he request for t he charter concerned came when the
aircraft was on the return leg of another flight. T hus
the pilot had already been flying for most of the day in
an IFR environment from large sealed aerodromes with
full condit ion information available, when without
warning he was asked to proceed to the bush strip.
The pilot had substantial experience flying twinengine aircraft in the general region. However, at the
time of the accident he d id not have a lot of recent
experience operating into that strip. This, combined
with the strip condition and pressure from the
passengers (who were in a hurry to depart), probably
induced a certain amount of anxiety in the pilot.
The factors of lack of recent experience at that strip ,
fatigue, unpreparedness and anxiety cannot be
discounted in this accident. These are a ll valid reasons
Aviation Safety Digest 117 I 13
�fo r a pilot to refuse a flight ; they should all - to the
greatest extent possible - be monitored by the
Company as well .
It is also possible that the pilot suffered from a
certain over-confidence, and considered that he could
handle (almost) anything . If you do not recognise your
limitations, you tend not to be as careful as the
situation dictates. Such an outlook m eans that one is
reluctant to admit that a situation is getting outside
one' s control. P r ide is often hard to swallow, so one
tends to press on - outside one's capabilities.
The other side of the same coin is the 'I never make
silly mistakes' or 'I always make it' mentality . It is this
same attitude which often makes pilots continue a lousy
approach , land at an unsafe airstrip , fly VFR in ghastly
weather, not take ice seriously when IFR, take off
without checking fuel quantity and quality, and so on.
Why did the aircraft lose directional control?
The first factor involved in losing control of the
aircraft's direction was that the pilot forgot to release
the park brake when commencing to taxi. That this was
not a part of the pre-take-off checks indicates a certain
weakness in the checklisl - understandably caused
because usually a set park brake becomes clearly
obvious when taxiing. In this instance it did not
because of the slippery surface conditions.
But there are other major controls at the pilot's
disposal to mainta in directional control : the nosewheel
stee ring, the rudder, asymmetric p ower.
In this case the nosewheel was consciously lifted from
the airstrip early to lighten the load on the main wheels
and to prevent it from becoming bogged in a soft patch.
The idea is to reduce total drag, increase acceleration
and reduce the takeoff roll - the well-known soft-field
takeoff technique. Of course when the nosewheel left
the ground it became useless as an aid to mainta ining
directional control.
In single-engine aircraft the p ropeller slipstream flo ws
over the tail surfaces, providing increased rudde r
effectiveness at low airspeeds. But on twins the
slipstream generally does not go anywhere near the
rudder - consequently the rudder is not much help
until the airspeed has built up.
E specially when o ne is operating in m arginal
conditions, there is a certain and justifiable relucta nce
to compromise performance by using a symmetric
power. But this is a control which may be used when
necessar y - and was no t used in this case.
The correct takeoff technique fo r a light twin o n a
soft a nd slippery surface is to mainta in just sufficient
pressure on the nosewheel to p rovide positive steering
- but not so much that it can sink into soft patches .
When airspeed is such that directional control can be
maintained with rudde r alone , the nose should be lifted
such that the n osewlieel is no longer on the strip.
If the aircraft begins to wander, the nosewheel should
be placed back on the strip, carefu l use made of brake
and if necessary a symmetric power , and the takeoff
aba ndoned if considered advisable. Of course the
technique outlined will not necessarily r esult in a very
sho rt takeoff roll; it will simply be as short as safety a nd
the condition s dictate. T his must be taken into account
when d etermining load or strip len gth requirements.
14 I Aviation Safety Digest 117
In the air
briefly
W hen the pilot saw his a ircraft careering off to one sid e
of the strip , toward the b ush, a h ut a nd a small h ill, he
decided tha t rather than go through he would try to go
over those obstacles. So the a ircraft t ook off at an
extremely low airspeed - it was flying in ground effect ,
on the back side of the power curve, a nd accordi ng to
the passengers with a horn (presumably stall warn ing)
sounding. I t is significant that the pilo t did not hear
any stall warning , n or did he recogn ise the situation
that the aircraft was in .
The a ircraft 'crawled ' up the side of the hill, and
there at a height o f p robably a bo ut 100 feet th ings
changed for the worse.
Up to this point, it would appear that th e aircraft
could have been flo wn out of its pred icame nt, usin g the
high power-weigh t ratio, trading height for speed , and
flying downh ill towards a low clear area. Bu t when the
ground is near and all you wan t to do is gain altitude
and irra tionally leave the problem behind, there is a
certain reluctance to lower the nose even though this is
necessary .
The pilot kept the nose high, the aircraft stalled and
dropped the r ight wi ng. His reaction WflS to ap ply fu ll
left aileron which was reta ined until the aircraft hit the
ground. But this incorrect reaction proba bly did n ot
make a lot of difference for from th at h eight it is not
possible to recover from an incipient spin .
Miscellaneous factors
Two other factors sho uld be ment ion ed. The first is that
the passengers' eq uipment was n ot tied down. Luckily
all the impact force s were downward and the equip men t
stayed on the floor. Had accelerations bee n in other
directions, serious inj ury could h ave resulted.
Secondly, although eq uipped w ith a ser viceable ·a nd
reliable HF rad io, and despite possible V HF
communication with overflying aircraft , th e pilot did
not report to Flight Service when taxiing. There was,
therefo re, no SARWATCH o n the aircraft - indeed ,
no one outside th e aircraft even knew that it was
taxiin g to take off. Again luckily there were n o injuries:•
for had the pilo t and/or radio been disabled no one
would h ave known of the accident and help wou ld not
h ave been forthco m ing until the next day.
safely also means real ising that conditions are always
chan ging, as is the pilot's view of what is happening.
Decisive corrective action should be taken immediately
u nless there is clearly no urgency - and modified as
soon as one even suspects that the correction was not
enough/was too m uch/was incorrect. This principle,
which is so impor tant and which has its application
through all phases of flight, is rarely consciously tau ght.
W ith respect to C ompany policy, several points
should be mentioned . First, there was inadequate
preparation for the flight - strip condition should have
been checked, the pilot questioned a bout whether he
was com pletely happy to make the flight, con sideration
given to cargo , and so on.
Secondly, pilot check flights were too lax - although
they were carried out , there was too much emphasis on
normal manoeuvres and not enough on 'bush'
techniques, low-speed work a nd the like. A large section
of the ch eck would often be the Chief P ilot riding as
check pilot on a charter fl ight, when of course
emergency manoe uvres could not be practised. Also
there was a tendency to regard the D epartmental
instrument rating renewal test as an adequate pilot
check .
T h irdly, lon g-term C ompany records of pilot recency
(e. g . in bush oper ations), strip condition, and so on,
would appe ar to have been both inadequate and
inadequately u sed .
Fou rth ly, C om pany procedures should have insisted
on a full SAR W ATC H from before takeoff until after
to uch-down wh en ever practicable. Use could also be
made of the ETD for SAR procedures. In som e ways
the circu it operations at the beginning and end of a
fligh t are the most critical phases of that flight - thus it
is important th at a SARWATCH be maintained over
these operation s. The time between an accident and
rescue action can be critical; without a SARWATCH it
can be fatally long.
Some of these Company policy factors were affected
by financial considerations - how much money can be
spen t checking and working on a pilot's possible weak
points on the off-chance that one day he/ she'will
encounter a certain condition? (Clearly the scope of the
checks in my C ompan y was inadequate - but how far
do you go?) O ther factors were affected by pilots' wellknown dislike of paperwork, and still others by simple
lack of organisation. The key to all this is
professionalism. We need to educate ourselves to be
always professional in our approach .
As always, many were the factors involved in the
making of the accident. We can consider ourselves
lucky that this time lessons can be learnt at the cost of
only the aircraft, not human lives.
*
*
Aviation Safety Digest would like to thank this pilot for his
comments on this accident. T he sole aim of the Digest is
to promote flight safety, and one of the best ways of
doing so is by recounting the experiences of others.
Clearly the message derived from aircraft incidents or
accidents can fall between two extremes, depending on
whether the occurrence was self-induced and handled
poorly, or beyond the pilot's control and handled well,
or a combination of these facto rs.
I t is most important to note that an incident does not
have to have been handled perfectly to convey a safety
message; indeed, the reverse is often the case. T his is
why the Digest on occasions presents articles in which
individuals' actions may be questionable. Articles are
never presented with any intention of denigrating
anyone, but rather only in the hope that we can all
learn from the experiences of others •
Conclusions
Technically one could simply call it a ll ' pilot error ' , and
leave it at tha t - certainly up to the point of the stall
the pilo t could have prevented the accident.
But the way a pilot flies a nd the decisions he/she
makes are very lar gely the result of tra ining and
Company policy . With respect to the former , it would
appear that the p ilot ha d not been a dequa tely tau ght
several items - most impor ta ntly in relation to
operations from bush a irstrips and also stall/ incipient
spin recognitio n , prevention and recover y.
Perhaps the most crucial lesso n which h ad not been
tau gh t was the im por tance of recognising reality and
a cting accordingly . Flying safely m eans critically noting
what is really happening even if it seems unlikely - and
not believing what on e would m erely like to see. Flying
"That's the Mackenzi e spread - bloody
hypochondriacs~'
(Courtesy of The Bulletin)
Aviation Safety Digest 117 I 15
�GYRO HORIZON
AIRSPEED
CDI
CDI
ALTIMETER
CLOCK
TURN
DIRECTION GYRO
OOO
VERTICAL SPEED
INDICATOR
VHF MIKE
The pilot had carried out his prestart, afterstart a nd
taxi checks using a card check list carried in the
aeroplane. After obtaining takeoff clearance he lined up
and commenced the takeoff roll. At about 60 knots the
aircraft's nose dipped perceptibly and this was
accompanied by a slight noise. The pilot rotated the
aircraft and shortly after establishing it in the climb he
noticed that the landing gear selector was in the UP
position, although he had not at that stage completed
the after-takcoff checks. H e selected the landi ng gear
down a nd obtained the correct indication ; then selected
it up and obtained a normal up and locked indication.
The pilot had intended carrying out a touch-and-go
land ing but, because of the abnormal occurrence during
the takeoff, wisely opted for a full stop land ing which
was uneventful. Postflight inspection revealed tha t the
propeller was abraded on its tips .
16 I Aviation Safety Digest 117
A technical examination of the aircraft, and the
landing gear in particular, showed all systems to be
functioning norma lly. The LAME carrying out the
inspection did, however, notice th at a non-standard
(not a factory fi t) C B rad io microphone had been
installed immediately below the landing gear selector.
Furthermore, the selector knob was loose and could
rotate through 90 degrees, in wh ich position the knob
presented a larger than usual area in the horizontal
plane; the significance of this was that it made the
selector knob more susceptible to an inadvertent knock
from som eone reaching for th e CB m icrophone.
A word is necessary here on the C 177 R G landing
gear system. The C l 77RG inco rporates a nose gear
squat switch , which is actuated by the nose oleo
extension, and wh ich electricall y prevents inadvertent
gear retraction whenever the nose gear strut is
°
00000000000°
~
TACHOMETER
ADF
LANDING GEAR
LEVER
CB MIKE
Modifications to aircraft can be approved by either Department of Aviation officers or
Departmentally authorised persons. While the great majority of approved modifications enhance the
overall operational effectiveness of the aircraft to which they are fitted, the odd exception does
sneak through the system. A case in point was highlighted by an incident involving a Cessna
177RG.
OOO
0
compressed by the weight of the aircraft.
G ive n these circumstances, investigators postulated
the following sequence of events:
• T he pilot, in reaching for the microphone after
startup, had accidentally bumped the undercarriage
selector knob to the UP position.
• Because the aircraft's weight was acting on the
land ing gear , the nose gear squat switch prevented the
gear from retracting.
• As lift developed during the takeoff roll , the
aircraft's weight started to come off the nose gear and
so the squat switch opened and a llowed the landin g
gear to retract.
• Hence, the nose dipped and the propeller struck
the ground. At this stage, however, the aircraft became
airborne, preventing further damage, and the pilot
found himself in the climb with the gear up a nd locked,
wi thout consciou sly having moved the selector knob to
the up position .
Subsequent discussion with the pilot confirmed that
this was indeed the probable sequence of events. The
pilot discounted any possibility of his having initiated a
premature retraction. H e did, however, recall that he
had inadverte ntly picked up the CB microphone when
he went to give his first R/T call of the sorti e. Because
he was unfamiliar with the aircraft, a nd because the CB
microphone was mounted between the VHF
microphone and the landing gear selector, he had
~
==1~
e
~
~
initially mistaken it for the VHF microphone. In
picking up the CB microphone he probably knocked the
gear selector knob to the UP position.
This inciden t should provide food for thought for all
those in the modifica tion development and approval
chain, Departmental or otherwise. While the pilot's
unfa m iliarity with the particular aircraft undoubtedly
contributed to the incident, the positioning of a
microphone immediately adj acent to a critical systems
control switch was unwi se. T here can be few General
Aviation pilots who h ave not at some stage fumbled,
without looking, for a hand-operated microphone while
primarily en gaged in another more pressing aspect of
flight. It is most important that such contingencies are
taken into account wh en cockpit modifications are
proposed. Consideration must be given, not just to
finding a space for an item, but to the whole question
of cockpit ergonomics - the 'scientific study of
efficiency in a workin g environment ' . An appreciation
of this need must be manifested, first, by the en gineers
who implement modifications and, second, by any pilot
whose opinion regarding a proposed modification is
sought. As this incident showed, modifications which
are not planned in the co ntext of cockpit ergonomics
can be a flight safety hazard •
Aviation Safety Digest 117 I 17
�~eade-i
Fuel tank water drain checks
Fuel or water
'After conducting an investigation for a Major Defect Report following the discovery of water in the fuel tank
of a sophisticated General Aviation twin I thought an article on the importance of conducting water checks
might be appropriate for Aviation Safety Digest.'
The aircraft was undergoing a 100-hourly inspection
when a large amount of water and fungus-like
contamination was found in the right-hand main and
nacelle fuel tanks. All endeavours to trace the source of
the contaminated fuel were unsuccessful. The
investigation similarly failed to determine when the last
fuel tank water drain check was carried out. It could
well be that the aircraft had been carrying the water for
over two weeks. I t had reached the engine firewall and
fuel filter, and the conditions were ripe for an engine
failure. While a single engine failure in itself may not
have been too dramatic, the scene was set for the left
engine to fail also: the pilot needed only to select fuel
cross feed from the right tanks and the left engine
would have drawn water from the contaminated right
nacelle tank as well.
Discussions generated by the investigation of this
discovery brought to light extreme cases of fuel quality
control neglect: pilots admitted that they had not
carried out a fuel tank water drain check in years of
operating turbine-powered aircraft.
Fuel quality co ntrol in Australia is of a high standard
and it is possible that this is the very reason for the
neglect of procedures once th e fu el is in the aircraft
tanks. But remember that water can come from several
sources, for example: inco rrectly stored drum stock;
contami nate<) hoses and pumping equipment; rainwa ter
Cattle-mustering aircraft -
inspection requirements
During the investigation of a major defect involving
a Cessna 180A , the left inboard flap bracket was
found to be loose and damaged. Further
investigation revealed cracks in the associated wing
spar. A similar investigation involving a Cessna 172
disclosed buckling of the rear spars of both
main planes.
Both of these aircraft h ad been used extensively
for cattle mustering, which involved operations at
low altitudes with the wing flaps partially extended.
The damage sustained by the aircraft was directly
attributed to this type of use.
Pilots and LAMEs should realise that aircraft
manufacturers base their inspection schedules on
average utilisation in standard operations. When an
aircraft is used in specialised operations or in a
p a rticularly h arsh environment, these schedules need
tO" be adj usted to account for the different operating
conditions.
In the case of aircraft used for mustering cattle,
18 I Aviation Safety Digest 117
(through poorly fitted tan k caps or defective cap seals);
condensation from partially filled tanks; and dissolved
water released from the fuel by a lowering of the fuel
temperature - such as will occur in flight.
Th~ problems of the presence of water in jet fuel are
not confined to those created by the engine's preference
for hydrocar bons. At very low temperatures severe fuel
system icing can occur, and at any temperature below
zero degrees Celsius, water droplets can freeze and clog
filters. Furthermore, water in jet fuel creates an
environment favourable to the growth of a corrosive,
microbiological sludge. The microbes live and multiply
in the environment between the fuel and water
separation level. In addition to its corrosive action the
sludge produced by the microbes sticks to capacitancetype fuel quant ity indicator probes , causing gauge
errors.
A further reminder tha t all those involved with fuel
quality control must always be thorough was provided
by the instance of a DC10 which uplifted a tanker load
of water. The er ror was not discovered until the aircraft
was taxiing for takeoff, when numbers one and three
engines became erratic and then stopped.
These are some of the reasons why regular checking of
fuel tank water drains is so important. Pilots and
engineers alike should be familia r with the drain points
on their aircraft and ensure that all points are checked •
there is a greater than usual proportion of
manoeuvring flight at low altitude, more exposure to
low-level turbulence and more flight time with flaps
partially deflected. While the former condition makes
the overall load spectrum worse than for normal
operations, the latter applies critical loads to specific
structural components - namely, the flaps, their
mechanism and the rear spar - much more often
than foreseen by the manufacturer.
A wing failure or a flap bracket failure causing
asymmetry would, of course, be catastrophic.
Consequently, all individuals associated with the
operation and maintenance of aircraft used for cattle
mustering and similar purposes are urged to increase
the frequency of the inspection schedules required
under the provisions of ANO 100.5.1 paragraphs 3.2
and 3. 3. This extra vigilance is likely to pay for itself
in forestalling more costly maintenance, and rriay
even prevent an accident •
0
To highlight the message contained in our reader
contribution 'Fuel tank water drain checks', the
followi ng Air Safety Incident Report was extracted from
the computer reco rds:
The pi.lot com pleted the daily inspection and preflight
checks on his Cessn a 182 and ever ything appeared
norma l. H owever, just as the aircrnft became airborne
the engine stopped. Fortunately for the pilot he was
able to land the aircra ft straight ahead on the remaining
runway, without further mishap.
Ini tially the p ilot was adamant that there had been
no sign of water in the fuel during his preflight drain
check. H e also confirmed that there had been fuel in
both tan ks and that the fuel selector had been turned
on.
The pilot subsequen tly checked thoroughly the fuel
remaining in his aircraft 's tanks and found that in fact
it was heav ily con taminated with water. Indeed, the
samp le he had taken from the tank water drains during
h is daily inspection had been all water! Because the
liquid he ha d drained seemed the same colour as the
fuel the aircra ft used and there were no signs of
contamin ation , he had assumed that the liquid was
uncon taminated fuel. Abou t 135 li tres of liquid were
dra ined before all evidence of water was removed.
There are two important aspects of this incident,
namely, how t he water got into the fuel a nd why the
p ilot fa iled to identify the problem during the da ily
insp ection. While th e q uestion of how the water got in
the fuel is most sc1·ious, it is the lat ln issue with which
this a rticle is concerned.
The report from the Bureau of Air Safety
Investigation confi rmed that the original sample taken
by the pilot was all water . The report continued: 'Pilots
should become thoroughly fam il iar with the
characteristics of aviation fuels and if a sample is of
uniform consistency (as in this case), the fact that it is
fuel can and m ust be verified'.
One method of doing this is to drai n the sample into
a vessel which already contains a sample of known fuel.
If the sample from the aircraft is all water, it will be
readily visible. Another 'ad hoe' method is to pour a
little of the sample into the palm of one hand : if it is
fuel it should vaporise and leave the skin dry; it will
a lso feel cool as it evaporates. Water will remain on the
skin. The sense of smell should also be used to help
with the identification.
The size of the fuel sample taken is important as it
must be sufficient to be conclusive. I t will vary
depending o n the fuel capacity of the particular aircraft.
Check on the amoun t you need to take from each drain
on you r aircraft, either in the aircraft operating manual
or from an appropriately qualified engineer, to ensure a
positive resul t.
Finally, the point needs to be ma de that the
fuel/water checks d iscussed above should be used on ly
when more positive tests cannot be made. If a visual
check is inconclusive, then the best and only certain
way to ensure your fuel is free from the da nger of water
contamination is to test a sample with water-sensitive
paste or capsules e
A viation Safety Digest 117 I 19
�Dress for crash survival
~la\)ing WitfJ
fire
During sta rt-u p the right engine on a Piper PA-23
Aztec caught fire. The fire reportedly burnt for
about 45 seconds before it was ex tingui shed by the
pilot and an aircraft refueller .
The pilot inspected the engine and d iscovered that
the fuel line from the fuel control unit tu the
injectors on the top of the engine had a loose
connection. This was tightened and the engine
ground run with al.I systems appearing normal. A
test flight without passengers was then carried out
a nd once again all systems appeared normal. After
this, passengers were embarked and the aircraft
resumed its schedule. Al no stage before these
passengers were carried was the aircraft inspected by
a LAME, nor was a properly recorded endorsement
of the occurrence entered in the maintenance release.
Inspection of the engine b y a LAME on the return
of the aircraft to its home base revealed lire or heal
damage to the following items:
• Alternator wiring
• Starter motor wiring
• The fuel control unit
• The mixture control stop
• T he outboard rocker drain tubes
• No. 1 cylinder induction lube rubber
The extent of the damage to some of these
components was sufficien t to indicate that this pilot
Each year a number of pilots are killed in su rvivable
acciden ts. O ne reason so me die so tragicall y and
unnecessaril y is their omission to wear suita ble
protective clothing . The use of protecti ve clothin g is an
in tegral pa rt of milita ry flying, but unfortunatel y the
prac tice has not become widespread in those civil
operations - for example, crop dusting, cattle
mustering a nd oil rig support - which also a re
rel atively high-risk activities . The possible consequences
of this omission a re u nhappil y illustrated in the
following summaries of two Australia n accidents.
• A cropduster crashed wh ile carrying out a procedure
turn between spraying run s. R escue rs fo und the pilot
about 10 metres away from the aircraft , whi ch had
burnt fiercely. Although the pilot suffered no impact
injuries, he subsequently died as the resul t of
extensive bu rns. H e had not been wearin g adequa te
protective clothing; indeed , the m ate1-ial of his
clothes te nded to absorb flam ma ble liquid ra ther
tha n resist it.
• During an a pproach to a property airstrip , a n
a ircra ft struck power lines and crashed. The post
m ortem indicated tha t the pilot had survived the
( impact but died while a ttemptin g to ge t clear of the
e nsuing fire. His cloth ing had not provided
protection.
A recen t study of accide nts durin g agricultural
operatio ns showed that lire a fter impact was the main
20 I Aviation Safety Digest 11 7
factor affecting su rvivabi lity. Fire occurred in onl y 14
per cent of the accidents, but these accounted for over
80 per cent of the fatalities. O ver two-th irds of these
fatal acci dents were survivable but the pilots were
overcome by hea t and smoke . In addition , serious a nd
minor burn injuries were sometimes sustained
unnecessarily.
Some of the fatali ti es and most of the burns could
have been avo ided by the use of the protective clothing
which is described in d eta il below.
Helmet. The primary function of the helmet is to
protect the head , eyes a nd ears, kee ping the wearer
conscious so that he can escape fro m the wreckage. It
should be light and shock absorbent with a smooth ha rd
surface to defl ect blows a nd resist penet ration . An inner
air layer between the shell a nd th e skull is a n in trinsic
part of the helmet's protective fu nction . The air layer is
created and maintained by the use of straps over the
head on which the helmet is suspended . These straps
must be properl y adjusted otherwise protection
efficiency wi ll be lost if the helmet is loose a nd shifts on
the head.
F lying overalls . O veralls protect the bod y from burns
as well as chemicals. For hot cl ima tes they a re normally
made from ligh twe ight cellular cotton. H eavier ma n m ade ma terials are used in more temperate climates .
Nylon should never be used . Any material used ideally
(continued 011 page 21)
Dress for crash survival
and h is passengers m ay have been very lucky to have
a rri ved safel y at their destination.
Breakdown of the insula tion on both the starter
cable and the alternator wiring was of sufficient
magnitude for either to have been a source of arcing.
Various fuel and oil seals had also been damaged, to
a degree which only a LAME rould have
determined. Of particular concern were seals which
were damaged in the fuel control un it and which
could well have allowed a massive fuel leak under
pressure into the engine compartment. In
combination with the badly insulated wiring, ignition
would have been highly likely. As the investigation
report concluded, fires resulting from similar
circumstances in the past have le<l to catastrophes.
Comment
The test fligh t conducted after the inspection by the
pilot proved nothing - damaged components may
last one year or one mi nute. T here is onl y one
course of action to follow after a n occurrence such as
this: write it up in the mai n tenance release and leave
the aircraft on the ground until the damage is
assessed and the en try cleared by a qualified
engineer •
(continued)
should have a lire-retardant treatment. Nomex provides
better lire protection tha n most fab rics but tends to be
hot and uncomfortable.
Like all protective clothing, overalls should be kept as
clean as possible, especially from oil a nd fuel
contamination .
Underclothing. Undergarments should be made from
natural fibre. String-type garments are prefera ble as
they increase thermal protection a nd help keep the
wearer cool. Nylon should never be worn against the
skin .
Gloves. Gloves are essential to protect the hands,
pa rticula rl y when hot buckles, handles, etc., need to be
opened .
Scarves. A scarf can be u sed to provide extra neck
protection.
Imme rsion suits. Maritime operations can pose a
different survival hazard, namely, h ypothermia. M an y
mi litary forces require immersion sui ts to be worn for
tran sits over water which is at 15 degrees Celsius or
less. Survival t ime in water of that temperature
averages only about 20 minu tes. Al 10 °C survival time
can be as li ttle as 10 minutes. W ind-ch ill effects reduce
these times even further.
The average sea tempera ture in Bass Strait is
15-20 °C during summer a nd 10- 15°C in winter.
Survival can be significantly prolonged by the use of
imme rsion su its. Both aircrew a nd p assengers in North
Sea operations now wear such suits. Un fortunately it
took a ditching, in which the people involved were
unable to get into life rafts, to emphasise the need for
protection against low water temperatures .
Conclusion
When a flight either does or could involve abnormal
risks, aircrew sh ould wear sui table protective flying
clothing. Experience has shown that the failure to do so
can m ean the d ifference between life and death •
Aviation Safety Digest 117 I 21
�Propeller blade damage and
maintenance
Concentration of stresses
due to defects
•
Normal stresses run parallel
How blades fail
The stresses which nor mally occur in a propeller blade
may be envisaged as parallel lines of force that run
within the blade approximately parallel to the surface.
Closely spaced lines will indicate regions of high stress
whereas widely spaced lines will indicate low stresses.
W hen a defect occurs it tends to squeeze together the
Ji nes of force in the defect area, thereby concentrating
the stress. T h is increase in stress may be sufficient to
cause a crack to start. Even a small defect, such as a
nick or dent, may develop into a crack. The crack in
turn results in a greater stress concentration and
accelerated crack growth. The resulting growth of the
crack will almost inevitably result in blade fa ilure. Th is
condition is so common, and the results are so serious,
that great emphasis must be placed on the daily and
preflight inspection of propeller blades for defects.
An aircraft's propeller is the end of the energy chain
which provides the aircraft with its motive force . It
does the job of converting the brake horsepower of
the engine into thrust. During normal operation
there are at least four separate stresses imposed on
the propeller: thrust, torque, centrifugal force a nd
aerodynamic force. Additional stresses may be
imposed by vibration caused b y fluttering or uneven
tracking of the blades. Because of the forces to
which they are subject, meticulous maintenance of
propeller blades is essential. Summaries of several
Australian accidents highlight this.
• During· an enroute cruise the outer 20 centimetres of
one blade of the port propeller of a Piper P A39
detached in flight. .The a ircraft diver ted to the
nearest suitable aerodrom e and landed safely.
Investigation revealed that the blade failu re was
caused by fatig ue which originated from a nick on
the lower leading ed ge radius of the blade.
• A Cessna 150 began to vibra te excessively during
flight. One blade of the propeller had shed 14
centimetres as a result of fatigue failure initiated by
stone da m age. The a ircraft was substantially
damaged during landing.
• Improper blend ing-out of a dent in the leadin g edge
of a propeller blade of a Cessna 188 caused a fatigue
crack which eventua lly resulled in 15 centimetres of
the blade separating in fli ght. A su ccessful forced
la nding was completed.
22 I Aviation Safety Digest 117
Where blades fail
Causes of blade failure
While fatigue fail ures usually occur within a few inches
of the blade tip, fail ures are possible in any portion of
the blade if dents, cuts, scratches or nicks are ignored.
No area or damage should be overlooked or allowed to
go withou t repair.
An investigatio n conducted in the USA of a
represen tative number of propeller blade failures
disclosed that the failures occurred because of fatigue
cracks wh ich started at mechanically formed den ts, cuts,
scars, scratches, nicks, or leading edge pits. In most
cases blade material samples d id n ot reveal evidence of
failure cau sed by material defects or surface
discontinuities existing before the blades were placed in
service.
Some fati gue failures occurred at a point whcr<'
previous damage had been repaired. This may be due
to the failure actually having started before the repair
was effected, or by the rep air itself being carried out
inco rrectly . For example, too m any blade-straightening
or rep itching op erations can overstress the metal,
causing it to fail. Blades should be repaired only in accordance
with the manufacturer's instructions.
M an y propeller blade failures may also occur d ue to
flutter. This vibration causes the ends of the blade to
twist back and forth at a high freq uency around an axis
perpendicular to the crankshaft . At certain engine
speeds this vibration beco mes critical and , if the
propeller is allowed to oper ate in this range, propeller
blade failure m ay occur . For this reason tachometer
accuracy is most important. Periodic tachomete r
accuracy checks should be accomplished using reliable
testi ng · instru men ts.
During propeller blade overhaul all items which
might obscure damage or defects (such as leading edge
boots and propeller blade decals) should be removed
and those areas - as well as the rest of the blade checked for corrosion, p itting and evidence of fatigue
cracks.
'Blade tips'
• Keep blades clean - cracks and other defects cannot
be seen if they are covered with dirt, oil or other
foreign matter.
• Avoid engine run-up areas containing loose sand,
stones, gravel, etc.
• D o not move an aircraft by pushing or pu lling on
the propeller blades - they were not designed to be
used as handles (there is, of course, also the potential
of injury should the engine start if the switches have
been inadvertently left on).
• Engine tachometers must be accurate to ensure that
propellers are not operated in any restricted R PM
range.
Conscientious observation of the advice offered in
this article will greatly reduce the possibility of propeller
blade failures •
In brief
,
It-
The performance of radio navigation equipment can
be affected by cer tain aircraft colour schemes.
In the U.K. the cause of weak signals on both
ADF systems on a Cessna Citation was traced to
reflective metallic tapes - part of the 'customised'
colour scheme of the operator - on the aft fuselage
and dorsal fin near th e flush-mounted ADF sense
antenna. R em oval of the tape cured the problem and
the ADF system fu nctioned normally.
With t he increased u se of flush-mounted antennae,
any change to aircraft' configuration or paint schemes
should be certified b y all trades, particularly the
radio/nav specialists. Also, when areas of skin are
covered by adhesive fil m, the skin beneath the film
should be checked periodically fo r corrosion •
A Cessna 402 landed during a rainstorm with a
quartering tailwind of 12 knots gusting to 22 knots .
Touchdown was made about 100 feet from the
threshold in an area of standing water. As the
a ircraft touched down it swerved to the right, and
the right main wheel dropped off the runway.
Power was applied to the right engine and the
aircraft was guided back onto the runway, where it
swerved again and the pi.lot Lost control. The aircraft
skidded off the runway once more and the nosewheel
struck a VASI light •
A Beech Bonanza was on finals when the cabin door
popped open. The d istracted pilot allowed the
airspeed to decay and landed short of the runway .
The a ircraft's nose gear, propeller and left wing
sustained extensive da mage •
Aviation Safety Digest 11 7 I 23
�
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I
�Contents
3
Weight and balance
Weight and balance calculations are yet another aspect of
pre-flight planning which a pilot ignores at his peril.
4
Against the odds
Pilots are continually required to assess the conditions and
circumstances under which they are operating in relation to
the capabilities of themselves and their aircraft.
5
Aftermath of Mt Erebus by Capt. William B.
Mackley (Retired)
1O
More than meets the eye
An accident in which a Cessna 180 crashed only about a
third of a kilometre from its destination seemed at first
simply a case of engine failure caused by fuel exhaustion.
Yet as the subsequent investigation revealed, there was
more to this accident than that.
11
The right decision at the right time
Making operational decisions is an Integral part of piloting.
12
lnflight structural damage
14
Stay with your aircraft
In recent months there have been two instances of pilots
leaving their aircraft in harsh and remote areas, in
circumstances in which there is little doubt that they would
have been much better advised to have remained with their
machines.
17
Emergency locator beacons: valuable safety
aids.
18
In brief
19
Caffeine and flying
20
Engine fires in flight
22
Flying a heading and the lanes of entry
24
Airspeed limitations for flight in turbulence
25
Oils ain't oils!
Weight and balance
Aviation Safety Digest is prepared by the Bureau of Air Safety Investigation in pursuance of Regulation 283 of the Air Navigation
Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to Australian licence
holders (except student pilots), registered aircraft owners and certain other persons and organisations having an operational interest
in Australian civil aviation.
Unless otherwise noted, articles in this publication are based on
Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 18390, Melbourne, Victoria 3001
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries and notifications of change of address should be directed to:
Mail Order Sales,
Australian Government Publishing Service,
P. 0. Box 84, Canberra City, A. C. T. 2601
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Reader contributions and correspondence on articles should be
addressed to:
The Director,
Bureau of Air Safety Investigation,
P.O. Box 367
Canberra City, A C. T. 2601
(c) Commonwealth of Australia 1983.
RM79/30212(5) Cat. No. 82 3302 4
Printed by Ruskin Press, 552-566 Victoria Street, North Melbourne,
Victoria.
Incident files contain two recent records of pilots topping up
the engine sump with adhesive instead of oil.
26
Reader contribution
A member of the parachuting fraternity issues a reminder to
pilots about the dangers of penetrating Drop Zones.
Covers
One of the services provided by the Department of Aviation is that
of establishing Air Traffic Control services at certain localities for
special events. The front and back covers of this issue of the
Digest depict scenes at the aerodrome and Airways Operations
facilities at Bathurst during the running of the 1982 Hardie 1OOO
motor race meeting.
2 I Aviation Safety Digest 116
All aircraft pilols' operating hand books contain a
cau tionar y note to the effect th al:
IT IS T H E RESPONSIBILITY OF THE PILOT AND
AIRCRAFT OWNER TO ENSURE THAT T HE
AIRCRAFT IS LOADED PROPERLY
T he 'loaded pro perly' cautio n refers to the fact tha t
the a ircraft must only be flown wi th its weight an d
centre of g ravity (C.G.) position within the
ap p roved limi ts.
Centre of gravity is a d ete rmining factor in flight
characte ristics. If the C.G. is too fa r forward it may
be d ifficu lt Lo rotate a n aircra ft for takeoff or
landin g, while if il is too far aft the aircr~ft may
rotate prematurely o n takeoff_ or ~ry lo pt~c_h u p_
d uring a cli mb. In short, long1tudm al stabth ty will
be 1·ed uced a nd this can lead to in adverte n t stalls or
spins. Fur ther, spin recovery becomes n:o~e d~f~cu lt
as the C.G. moves aft of the approved hm1t. 1 his
fact was grap hically illustrated in the following.
report issued by the U.S. National T ra nsportatio n
Safety Board (NTSB).
. .
. .
• A pilot a nd his student we re p racusmg spms 111
a PA28-140 whe n o n e of them was hea rd to call
ou t over the radio, ' It still won't come o ut. Mayday
Mayday.'
Witnesses saw the a ircraft spinnin g dow n almost
verticall y before it hit th e ground. The NTSB
investigatio n d isclosed th at the aircraft had a gross
weigh t of about 1902 pou nds a nd that the C.G. was
about 87 inches aft of the specified datu m at the
time of'the crash. Spins and certain other aerobatic
ma noeuvres are permi tted in the PA28 only wh en
it is used in the utility category, in wh ich
configu ratio n the gross weigh t an d cen tre of gravity
are not to exceed 1950 pounds or 86.5 inch es aft of
a specified d atum respectively.
The ma nu facturer has stated tha t it is h azardous
to conduct spins in the a ircraft whe n the utility
category aft C.G. limit is o nly slightly e_xceed~d .
T he investigation showed that, at the time of th e
accide n t, the aircraft h ad approxima te ly 32 gallons
of fuel on board . 'If this a ircraft had been
despatched p rope rl y fo r u tility operation', the
NTSB concluded, 'a correct weigh t-and -ba lan ce
determination would h ave disclosed th at the
maximu m allowable fuel load was abou t 2 1 gallons.
T he a ircraft's gross weigh t u nder those con d itio ns
would have been approximaLely 183 l pounds, a nd
the C.G. would the n have been at the utility
categor y aft limit of 86.5 inches.'
Accidents res ul ting from fau lty weight and balance
p reparation a r e n ol, of course, restricted to aircraft
e ngaged in aeroba tics. For example, Aviation Safety
Digest 86 details th e fatal acciden t involving a Twin
Comanche which was overloaded and o p erating
o utside C.G. limits, and which pitched up
uncontro llably after takeoff.
Loading an aircraft
I n ma ny GA aircraft it is not possible to fill all seats,
use th e maximum baggage allowance, fill up with
Aviation Safety Digest 116 I 3
�fuel and still remain within the approved weight
and balance limits. In those circumstances, pilots
who do not wish to leave a passenger behind must
reduce the fuel load and plan on shorter legs en
route or limit the baggage carried, or both.
Note that because of the size of many baggage
compartments there is sometimes a tendency to fill
them to capacity, ignoring the placarded baggage
weight limitations. This could produce a C.G. aft of
the allowable limits and create a highly dangerous
degree of longitudinal instability. Note also that fo~
some aircraft, if the maximum baggage allowance 1s
used, restrictions are placed on rear seat occupancy.
Improper loading and performance
An excessive or imprope rly distributed load will
adversely affect an aircraft's performance in a ll
phases of flight.
Cruise. At normal weights, an aircraft requires a
certain an gle of attack to maintain straight-and-level
flight a t a given airspeed. To accommodate a
heavier load at that same airspeed, the angle of
attack must be greater to provide the increased lift
that is n eeded. More power must then be added to
overcome the increased drag which is a
consequence of the increased angle of attack. This
in turn burns more fuel , thereby reducing the
range of the aircraft.
Climb. An overloaded aircraft will take longer to
climb to a given altitude , because the angle of attack
is greater and the extra thrust required to carry the
additional weight limits the rate of climb (and may
also limit the climb speed) as this is dependent on
the surplus power available. The additional time
spent climbing at a higher power setting will also
increase fue l consumption.
Flight load limit. Assume an aircraft has a
maximum flight load limit of 4g. If the allowable
gross weight is not exceeded, then the wings can
safely support four times the weight of the aircraft
and its contents. In accelerated flight (turns, pullups, turbulent air) the actual load on the wings of
an aircraft carrying excess weight clearly would be
greater than that if the aircraft weight were within
the auth orised limits. This results in greater stresses
in the win g structure. Overloading there~c;>re has
the effect of decreasing the g load capability of an
aircraft and thus could result in the wing being
stressed to the point of popped rivets, permanent
distortion, or even structural failure.
Load distribution. Loading an a ircraft is simply a
matter of complying with weight limitations and
distributing the load so the C.G. falls within the
allowable range. This is done by arranging the load
in accordance with the C.G . envelope detailed in
the pilot's handbook. If the load is distribut~~ su.ch
that the C.G. falls outside the enve lope, stability 1s
adversely affected and abnormal contro\ forces may
develop. Stalling speed , takeoff distance, landing
speed and longitudinal control may be dangerously
affected.
Summary
Correct weight and balance is a crucial factor in
safe a ircraft ope rations. Weight and balance
calculations are ye t another aspect of pre flight
p lanning which a pilot ignores at his pe ril •
4 I Aviation Safety Digest 116
Aftermath of Mt Erebus
Pilots are continually required to assess the
conditions and circumstances under which they are
operating in relation to the capabilities of
themselves and their airuaft.
It is one of the prime skills of piloting to be able
to operate safely right to the edge of those
capabilities. The pilots who consistently do so
successfully are without exception those who know
their limitations and who do not hesitate to
abandon a sortie or a particular phase of flight if
they assess that there is any possibility of exceeding
those limitations.
Often there is a very fine dividing line between
safe and unsafe operations. This dividing line is
perhaps more difficult to recognize when a pilot is
completing a routine task, such as flying into a
destination with which he is thoroughly familiar. As
the pilot involved in the accident discussed below
discovered, this can be a trap. When you are
operating close to the limits - which in this
instance were defined by the strip dimensions and
the weather - you have got Lo keep the odds on
your side.
A Piper PA28 was being flown into a private
category Authorised Landing Area (ALA). The
ALA, which the pilot had used before, was 600
metres long and 30 metres wide. A hot, gusty
crosswind of about 12 to 15 knots was blowing from
the west. The pilot described the conditions as
being very turbulent. He circled the ALA several
times before deciding to make an approach from
the south. At about 30 feet on final approach, just
as the pilot was reducing power, the aircraft
encountered a violent, turbulent gust of wind and
the right wing dropped about 35 degrees. The pilot
managed to lift the wing, but the aircraft 'fell out of
the sky', bouncing heavily after contacting the
strip's surface. Touchdown was 120 metres into the
ALA.
The aircraft bounced several times and despite
the corrective actions of the pilot, nm off the righ t
hand side of the strip. Substantial damage was done
to the right main-plane by a one-metre high tree
stump which was only 17 metres from the strip's
centreline.
Analysis
Although on previous landings the dimensions of
this ALA had presented the pilot with no
d ifficulties, the turbulence and crosswind on this
occasion added a new dimension for which he
failed to allow. Caught out by the demanding
landing conditions he was unprepared to overshoot,
which wo uld have been his best course of action
either from final apprnach or after the first bounce.
He was then further caught out by the presence of
the tree stump which encroached on the minimum
required dimensions of the ALA.
.
This pilot doubtless could have dealt with the
strip dimensions, the turbulence or the cr?sswind. in
isolation. In combination, however, on tlns occasion
they exceeded his limits, and by not being prepar~d
for the situation the pilot a llowed the odds to bmld
up against him •
by Capt. William B. Mackley (Retired)
Capt. William B. Mackley summarizes in the following article the continuing controversy s~rrounding
the probable cause of the crash of an Air New Zealand DC-10 on th~ ~lopes of Mt ~~ebus m the_
Antarctic in November 1979 the various conclusions reached - off1c1al and unoff1c1al - and his own
conclusions based upon hi~ broad experience as an airline captain and in the field of aviati?n s~fety.
Capt. Mackley, a Royal New Zealand Air Force bomber pilot in Europe ~nd patrol plane pilot m the
Pacific during World War II, joined New Zealand Airways Corp. as a captain at th~ ~lose of the war.
He transferred to TEAL now Air New Zealand, in 1965 and retired as Fleet Captain m 1970. He
subsequently returned to the airline with the title of Flight Safety Advisor, lnternatio.na~.
.
Acknowledgement is made to the Flight Safety Digest and Capt. Mackley for perm1ss1on to reprmt
this article.
The crash of an Air New Zealand DC-1 0 on the
slopes of Mt Ere bus with the loss of 257 ~ives was so
far removed from the general run of acodents to
commercial aircraft as to make it unique. So, too,
were the inquiries, appeal and controversy th at
followed.
World attention was draw n to the accident
because of the remote a nd inhospitable region of
Antarctica in which it occu r re d. The investigation
by New Zealand's Inspector of Air Accid ents a n d
the public inquiry tha t followed unfolded a
mo unting seque n ce of poor d ecisions, bad
judgme nts, lac k of oversigh t, inadequate
communication a nd outright errors. All came to
bear to lend sympathy to th e captain and crew who,
it appeared , had been grossly misled.
I t was only natu ra l that the public o f New
Zeala nd, a great many of whom had lost friends or
relati ves on Fligh t 90 1, wou ld want to know
p recisely, n ot only how such an acciden t cou ld
occur, but in an airli ne that prided itself on its
excelle nt standards and was held in high regard in
the industry, wh y?
Initial report
It was a lon g six month wai t fo r th e release of the
re port of New Zealand Chief Insp ector of Air
Acciden ts Ron Chippind ale. T he Inspector was
under consid erable p ressure to produce this report
a n d to have it comple ted in this time was an
Aviation Safety Digest 116 I 5
�impressive ach ievement. It must be remem bered
th a t su ch a report cou ld only be co m p iled from
p e r sonal in vestiga tio n a nd th e questio nin g o f th e
many p e rsons in a n y wa y in volved wit h eve nts
leading up to th e accident. H e h ad n o facility to
take e vidence o n oa th or to liste n to t h e crossquestio ning t h at would take p lace in a cou r t o f law.
His conclusio ns, while drawing atte ntion to th e
inadequ acies in company p rocedures, crew briefing
a nd computer flig ht pla n sto r age a nd pre paration,
ne verthe less la id the blame squa r ely upon the c r ew.
H e noted seve n co mmissions o r o missions of the
crew tha t led directly to the accide nt and concluded
by stating th a t:
The probable cause o f this acciden t was the decision of
the captain to continue the flight at low level toward an
area of poor surface a nd horizon definitio n when the
crew was not certain of their position and the
subsequent ina bility to detect the rising ter rain which
intercepted the aircraft's flight pa th .
This assess m e nt o f probable ca use d id n o t please
the pilo t group in view of th e m a n y co ntributin g
factors that took place within th e company prio r to
th e flig h t.
Mahon Report
In due co u rse, a Royal Commission to inq uire into ,
and r e p o rt u po n , 10 questio ns relating to the cr as h
was em pa n e lled with The Hono urable P . T. Ma h o n ,
Judg e of the Hig h Cou rt of New Zeala nd , as Royal
Commissio ner.
A s a public inq u iry, a t which witnesses would be
called and cross-examined by va rio us co unsel, it was
ope n to a n yo n e inside o r o utside th e company wh o
felt h e or sh e co uld m a ke some contribution to th e
p roceedings. I n this way, it was exp ected t hat a ll
contributory causes co uld be exa mined to the n'th
degree a n d th e d ominant cause d etermined with
complete acc uracy.
It was impe ra tive that this b e so, fo r suc h a
re port that wo uld be disseminated wo rldwide wou ld
be inte nsely studied by othe r o p e ra to rs for the
in fo rmatio n it must contain th a t wo uld lead to a n
enha n cem e nt of flig ht safety.
If it fails in a n y meas ure to exam ine to finality all
contributing ca uses o r if it r each es con cl usio ns
based o n ass u m ptio n s wh e n those ass ump tio ns are
capable of resolutio n o r explanatio n in th e co urt
room , th e n it falls far short of its objective.
The M ahon R eport, as it h as become known , was
r eleased in April 198 1, a nd immediate ly created
controver sy a nd eve n furo r e as a r es ul t of som e of
t h e sta te m e nts a nd j udg m e nts put fo rth . M r Justice
Maho n enu mer ated I 0 factor s th at co-existed to
ma ke th e d isaste r possible, witho u t a n y o n e of
whic h th e accide nt would n o t have h appe ned .
Among th e 10 factors, Justice Ma h o n gave as the
d o mina nt ca use, ' .. . the act of th e airline in
ch a n g ing th e co mpute r track o f th e aircraft witho u t
telling t h e crew - it was the o n e fac to r which
continued to o p e rate fro m the time befor e th e
aircraft left New Zeala n d until t h e time wh e n it
st ruck th e slopes o f M t Erebus'. H e went o n to
state:
6 I Aviation Safety Digest 11 6
'In my opinion, neither the captain nor the first
officer n or t he flight engineers made any error
which contr ibu ted to th e d isaster and were not
r es po nsible for its occ u rrence'.
T his judgment was, o f co u rse, ha iled by th e
a irline pilo ts as a victo r y. How ma n y times in the
past h ad pilots been h e ld b lameworth y for an
accide n t wh en now, with o ur m ore enligh te n ed
kn owled ge o f hu ma n facto rs, weather, a ircraft
p e rformance a nd so on, t h ey cou ld be exo nerated?
O n t h e surface, Ere bus seemed ve r y much a case in
p oint.
Management criticized
Pe rha ps th e matter mi g ht h ave rested there h ad not
J ustice Mah o n indu lged in som e fu lm inatio n against
th e co mpan y in a p aragrap h o f the report entitled ,
'Th e stan ce adopted by the airli ne before t h e
Commissio n of Inqui ry'.
Sub-paragra ph 373 sta ted:
T her e is no doubt that the aidine chief' exec utive,
shortly after the occu rrence o f the d isaster, adopted
th e fixed opin ion that the fligh t crew was alone to
blame and that the administrative anq operational
systems of the airl ine were nowhere at fault. I have
been fo rced to the opinion that such an attitude,
emanating from this very a ble, but evide ntly autocratic,
chief executive, co ntrolled the ulti mate course adopted
by the witnesses called on behalf o f the air line.
S ub- paragrap h 374 stated :
T he relevant evidence in this context was given by the
execu ti ve p ilots a nd by mem bers of the Navigation
Sectio n. T he fact that the navigation cou rse of the
aircraft had been altered in th e computer had been
d isclosed by the Chief Inspector in his report dated 3 I
May 1980, six months after the disaster. But it was not
until the Commission o f' Inqu iry began sitting that the
airline publicly ad mitted that this had occurred.
He nce the tactics adopted by the Navigation Section
witnesses which were d esigned to prove; if they could,
that the computer mistake and its consequences could
and should have been avoided by the crew and that the
captain and his co-pilot had committed that ve ry long
catalogue of aviation blunders and malpractices to
which I have previously referred.
I can visualize withou t difficu lty not only the extent
but also the nature of the managerial pressu re exe rted
on these witnesses. T hey all declined to ad mit th at
there had been any mistake or omission on their part
which could have been a material cause o f the d isaster.
Let us pass on to sub-paragra p h 377. I t was
sh attering:
No jud icial officer ever wishes to be compelled to say
that he has Listened to evide nce wh ich is false. He
always prefers LO say, as I hope the hundreds of
j udgmems wh ich I have written will illustrate, that he
cannot accept the releva nt ex plana tion, or that he
prefers a contrary version set out in the evidence.
But in this case, the palpably false sections of
evidence which l heard could not have been the result
of mistake or faulty recollection. They originated, I am
compelled to say, in a predetermined plan o f
d eception. T hey were very clearly pa rt of an attempt to
conceal a series o f disastrous ad mi nistrative blunders
a nd so, in regard to the particular items o f evidence to
which I have referred , I am forced relucta ntly to say
that I had to listen to an orchestrated litany of lies.
Wreckage of Flight 901 was scattered over a wide range of the Ice and snow-covered slopes on the northern side of Ross Island after
ground impact. All 20 crew members and 237 passengers on board were killed in the accident.
(Photographs courtesy ef New Zealand Offia of Air Accidenls lnvesti15atio11).
Subsequent appeal
S uch a bitin g accusation led to the im m edia te
res ig n a tio n of Ai r New Zeala n d's Chief Executive.
T h e company, j oi n ed by th e C h ief Executive a n d an
executive captain, th en filed an appeal against these
accusations with th e New Zealand Court of Appeal.
T h e doc u ment, entitled j udgments of the Court of'
AjJJ1eal of' New Zealand, u nder the heading, 'The
challenged paragr aphs', states:
. .. th e case is not an appeal from the Commissioner's
fi ndings on causation or other matters. T he applicants
acknow ledge tha t they have no rights of appeal. What
they attack a re certain paragraphs in the Commission
report which deal ver y largely, not with the causes and
circumstances of the crash, but with what the
Commissioner calls 'the stance' of the airline at the
inq uiry before him. The applicants say that in these
pa ragraphs the Commissioner exceeded his powers or
acted in breach of natural justice, and further that
some of his conclusions were not supported by any
evidence wha tever of probative value. Their counsel
submit that a fi nding made wholly without evidence
capable of supporting it is contrary to natural justice.
Court's conclusion
The Ap peal Court in its concl usions, which
co ntained conside rable legal d iscourse on the scope
a nd j urisdi ctio n of a Royal Commissio n of I nqu ir y,
said in its j u dg rne nt:
We now come to the most serious complaint. It
concerns paragraph 377 of the report (quoted above),
a paragraph building up to a quotable phrase that has
become well known in New Zealand and abroad. The
applicants claim that these findings were not based on
evidence of probative value and that the affected
employees were not given a fai r opportunity of
answering such charges. T he general allegation in the
statement of claim that the findings a ttacked were
made in excess of jurisdiction has in our view a special
bearing on this paragraph. The applicants say that
the paragraph affects a considerable number of
employees ...
We accept that reasonable readers of the report
would take from it that the conspiracy, which the
commissioner appears to postulate in his references to
a 'predetermined plan of deception' and 'an
orchestrated litany of lies,' was seen by him as so wide
as to cover all those persons. Paragraph 377 is the
culmination of a series of paragraphs beginning with
paragraph 373 and separately headed by the
commissioner, 'The stance adopted by the airline
before the Commission of Inquiry.' They include
specific references to the chief executive, described as
'very able but evidently autocratic' in the context of an
allusion to what 'controlled the u ltimate course adopted
by the witnesses called on behalf of the airline.' There
are also specific references to the executive pilots and
members of the navigation section.
It is possible that some individual witnesses did give
some false evidence during this inquiry. The applicants
accept that this was for the commissioner to consider
and that it is not for us to interfere with his assessment
of witnesses. But the complaint goes much further than
that. It is that there is simply no evidence on which he
could find a wholesale conspiracy to commit perjury,
organized by the chief executive, which is what this
part of the report appears to suggest. Our conclusion
that here the commissioner went beyond his
jurisdiction and did not comply with natural justice
Aviation Safety Digest 116 I 7
�- 11
I
makes it unnecessary for us to decide whether there
was any evidence that could conceivably warran t such
an extreme finding. It is only right to say, however,
that, if forced to d ecide the question, we would find it
at least difficult to see in the transcript a ny evidence of
that kind.
The language of paragraph 377 has evid ently been
carefully selected for maximum colour and bite and
the commissioner has sought to reinforce its impact by
bringing in his status and experience as a judicial
officer. While unfortunate, it is no d oubt that result of
a search for sharp and striking expression in a report
that would be widely read. He cannot have overstated
the evidence deliberately. Similarly, at senior
management level in Air New Zealand, there would
ha ve been a natural tendency to try to have the
company's case put in as favourable a light as possible
before the Commission; but it was add ing a further
and sinister dimension to their conduct to assert that
they went as far as organized perjury.
The overturning of the paragraphs complained
of in the Mahon R eport put the boot on the other
foot for the Airline's Chief Executive, and h e lost
no time in suggestin g that the Royal Commissio ner,
Justice Mahon, resign.
Cabinet action
In a letter to the Prime Minister, Mr Muldoon,
Justice Mahon indicated that it wo uld be untenable
for him to conti nue sitting as a Hig h Court judge
and that h e should retire. Prime Minister Muldoon
said that the Cabine t had spen t more than an hour
a nd a .half discussing Justice Mahon's letter a nd that
most of its members took the view th a t the Court of
Appeal judgments were so undly based. However ,
w ith r egard to all the backgrou nd and the
circums ta nces in w hich Justice Mahon fo und
himself, the Cabinet felt it o nl y fa ir that he sh ould
h ave an opportunity to take th e matter to th e Pri vy
Council.
We are now le ft with two repo rts , that o f the
Inspector of Air Accidents and that of th e Royal
Com m issione r , w hich in their sum m ations a r e in
almost total conflict. It was only n a tura l that the
s upporters of these two camps would keep the
controversy alive.
Press debate
H eadlines in the 29 J a nu a r y 1982 iss ue of The New
Zealand H erald proclaime d , 'Inspector's mind closed
at hearing says Erebus Jud ge'. T h e news paper
continued:
The Royal Commissioner in to the Mt Erebus DC- 10
disaster, Mr Justice Mahon, said last night that the
Chie f Inspector of Air Accidents, Mr R. Chippindale,
had a predetermined and closed mind throughout the
inquiry. The comment was the Judge's reactio n to Mr
Chippindale's criticism of the Commissioner's findings
. . . Mr Chippindale alleged in the docume nt released
by the Minister of Transport that Mr Justice Mahon's
conclusio ns would have been 'exposed as illogical' if
examined a nd re viewed by aviatio n ex perts. Mr Ju stice
Mahon said, 'I was aware that, if I did not accept the
Air New Zealand manageme nt's view of th e cause or
the disaster that was accepted by Mr Chippindale, I
would be very unpopular in official circles'.
8 I Aviation Safety Digest 116
T h e lengthy report con tinued with this assertion
from Mr Chip pi n dale:
'The change in the co-ordinates could not have been
the dominant cause of the crash, for even in its
changed fo rm the flight plan wa s safe to fly as printed.
Had it been flown by a crew o f automatons, the
aircraft would ha ve flown over Mt Erebus, turned and
returned safely. In the event the crew decided to
descend the a ircraft in a n area on the opposite side of'
Mt E1-ebus to that approved for any descents, and t hey
must be res ponsi ble fo r th is decision.'
Mr Chippindale said his report on the accident, 'was
the result of the detailed investigations and
deliberations o f some 18 h ighly qualified internationa l
experts and ai1-craft accident investigato rs. The judge
had stated as fact many items of' hypothesis and
supposition in h is report. This, a nd his skill in rhetoric,
made his report a most convincing and persuasive
document'.
Thi· New Zmland 1-fl'rald ol' 2 Februa r y 1982 came
o ut with fu rthe r bann er h ead lines - ' Pilots partly
to blame sa ys ex p ert!'. The fo llowing article said , in
part:
Air Marshal Si 1· Roch ford Hughes, who advised
cou nsel for the Erebus Commission ori technical
matters, be lieves the pilo ts of the Air New Zealand DC10 must accept pan o f the blame for the disaster. Si1·
Roch ford said he bel ieved a bo ut 90 per cent o f' the
accident was due to organizational fa ults, but he could
see no way in which the crew could escape accepting
some responsibili ty. Their unpardonable lethal mistake
was to drop below minimum safe altitude (MSA),
re lying on a navigation system whose co-or dinates they
had not checked wi th their topographical map.
He also said , 'J believe it is a basic tenet of good
ainnanship Lo check any aid, no matter how
sophisticated, by some other a id or visual reference
before descending below the MSA'.
'Risk' or 'assumption'?
The words o f Gerard M. B ruggink in a n article
e ntitled 'Calculated r isk or blind assumptio n ' also
ring in the ears.
One wonders whether the Judge wou ld have made a
different judgment and moderated the extravagan t
lang uage used in his fi ndings had natural justice not
been denied? H ad the navigation group, as only o ne
a mong those castigated, been given the opportunity to
produce witnesses to support the sl<ltements assumed
by the J udge to be untrue, then perha ps they would
have been relieved of the stigma imputed in the
fi ndings.
T he ver y nature of Erebus was guaran teed to bring
forth a depth of emotion in a small country like New
Zealand that had not p reviously experienced a n air
disaster of this magnitude. As e vents unfolded in the
publi c inquiry, considerable sympathy was generated
for the crew, a nd, of course, Justice Mahon's findings
accentuated this. The Commission's exone ration of the
crew materially shifted the responsibility for saf'e fligh t
away from the cockpit to th e man y people involved in
the preparation of navigatio n, flight brie fing, compute1·
programming and fl igh t plan preparation. For an;1
pilo t grou p to show enthusiasm for such a j udgment,
despite the evidence o f crew errors and dubious
a irmanship, is to set back the clock in the endeavours
being made to ma ke flight safer.
Pe rha p s th e m ost fo rthrig ht opinion on the cause
o f th e Erc bus accid ent was expressed b y Si r
Geoffrey Roberts, TEAL's (now Air.New Zealand)
first C hief Executive and later its Chairman of
Directors - a gentleman who can b e said to be
New Zealand's Mr A viation. Sir Geoffrey says in the
final pages of his book, To Fly a Desk:
So many people have commented on so many different
aspects of the crash that one hesitates to put forward
yet a nother o pinion. The obvious criticism that can be
made of 'experts' and their theories is that anyone can
be wise with the benefit of hindsight. It is also sadly
true that little can be said now that will comfort those
who suffered.
But there is one excuse for speaking up, and it is a
valid one. If we can avoid another disaster by delving
into the lead-u p to this one, then the delving is
justified a nd any hu rt caused in the process has to be
accepted . .. I say quite flatly the main cause was the
fact a pilot fai led to locate himself in relation to
ground feat ures and flew his aircraft into the side of a
mountain .
T o the question, ' Isn't that being simplistic?', Sir
Geoffrey responded:
'No. It's bei ng truthful. I am aware that Mr J ustice
Mahon, who was the Commission, holds the primary
cause lay in programming the aircraft to fl y directly a t
Mt Erebus without telling the crew. I simply don't
agree. H e is a learned man, and his investigation was
painstaking . H e was, of course, sincere. But he was
wrong. I am utterly convinced of that, and I will go to
my grave knowing h e was wrong.
'The error in prog ramming was a contributory cause.
The basic cause was pilot error.
'I said earlier an a irline pilot may have to make only
o ne vital decision in his life, and it h as to be the right
one. A vita l decision was called for on 28 November
1979. The right decision was no t made'.
T h e questioner suggested, 'Or maybe the right
decisio n was made too late, remembering that the
cap tain had d ecided to turn away j u st before
impact?'
Sir Geoffrey's r etort left no room fo r doubt:
T hat's only playing with word s. In the air, your speed
is such that postponement of a decision amounts to a
wron g decision. And inability to realise a decision is
called for amounts to something worse, if that is
possible. T he moment for decision came during the
descent, say at 1800 metres. Let us agree the pilot
believed he was in visual meteorological conditions,
even though we now know he wasn't - he was
experiencing a white -out, something he hadn't
encountered before. H e could see the ground, but he
could not identify ground features - features which
a re particularly prominent in the a rea under good
weather conditions . . . Long, long before he eventually
became uneasy, the pilot should have admitted to
himself tha t he was uncertain of his position. And,
such bei ng the case, it was his p lain duty to turn· back
a nd regain he ight. Furthermore, he should have
a ppreciated tha t neither he nor his crew knew the area,
and this alone should have prompted extra caution.
This is a matter of airmanship, an old-fashioned
term perhaps, but one tha t still has meaning. You can
fill your cockpit with sophisticated aids, but someone
still has to be sitting there to over-ride them if they go
o n the blink. I don't believe the day when passengers
are sent off on robot-controlled flights will ever come,
bu t, if you were to accept the findings of the
Commission of I nquiry, you could almost be forgive n
for concluding the day is already here.
Crucial point
The mountain of evid ence generated b y this
Inq uiry, the subsequ ent Appeal, the unceasing n e ws
media and the television probing and comment, in
my view, overlooked a most crucia l point. ')'he
captain was regarded to be and it was also stated in
evidence that he was a most competent pilot. But
did he act p rofessionally? I s u ggest that there is an
extremely wide gap between competency and
professionalism!
Can a pilot be taught to take a professional
approach to his job? I rather think not. I can
envisage, and in my career have encount ered, many
situations where the professional approach may n ot
be to t he advantage of t h e employer - often the
re verse.
Professionalism, as I see it, is an individual
attribute and one that it is extremely necessary to
have to ensure survival in th e flying game. I t is my
opinion that t h e captain of Flight 90 I to Ere bus
had a number of opportunities, both in flight
preparation and in th e conduct of the flight, to
demonstrate true professio nalism . Probably the
over-riding one was the fact that the captain knew it
would be his last opportunity to fly to Antarctica! •
Taxiing accidents
A PA-3 1 was being taxied towards a terminal to
p ick up passengers. The pilot saw a motor vehicle
approac hing to cross in front of him from left to
r ight. Believing he h ad s uffic ient clearan ce, the
pilot did not slow down or stop, and neither d id the
vehicle. The right w ing of the a irc r aft struck the
right rear o f the vehicle.
*
*
*
T h e pilot of a single -e n gine taildragger experienced
d ifficu lty in seeing o ut o f his cockpit while taxying
after a late afternoon sortie, due to the combination
of the sun in his eyes and the high nose attitude of
his aircraft. Accord ingly, he concentrated his
lookout to th e left side o f his aircraft , wh ere th e
s u n was least troublesome. T h e consequence? His
right wing struck th e tail of an a irc raft w hich was
stationary on th e taxiway in front of him. This
cau sed the t a ildragger to swing arou n d to the right
and so add ins u lt to injury b y chopping into the
stationary aircraft's left wing w ith its propeller.
Only one comment can be m a de a bout taxying
acc idents of t his type - there is no excu se for
them. I f you can n ot visually clear the area through
whic h you are m oving, th e n do not taxy wit h out
outside assistance •
Aviation Safety Digest 116 I 9
�More than meets the eye
The right decision at the right tillle
An accident in which a Cessna 180 crashed only about one third of a kilometre from its destination
seemed at first simply a case of engine failure caused by fuel exhaustion. Vet as the subsequent
investigation revealed, there was more to this accident than that.
Making operational decisions is an integral part
or p iloting. T hese decisions fall into one of two
categories:
• T hose mad e on the ground during preflight
planning, when factors such as the
meteorological forecast, the ro ute, weight and
balance, per formance criteria, fuel, etc., have to
be assessed . T hese decisions should be made free
from the constraints of time or the pressures
which can arise in flight.
• In tlig ht decisions, which can range from the
al.most_ subconscious translation or visual a nd flight
f11_g ht m.strurr_ient cues into physical manipulation
o l the aircra ft, to those in which a series of
occurre nces which may threaten aircraft safety
have lo be dealt with coolly and quickly.
. The latter type of d ecision is probably the most
~ t fficu lt to make, for while the pilot assesses the
!acts and reviews h is possible courses of action,
h is ·office' - unlike the office of most decision
makers - drones inexorably onwards, in all
li kelihood making the situation more difficult
with each passing minute and nautical mile.
T he fo llowing aircraft incident is relatively
simp le, yet it p rovides an excellent lesson in
decision making - both good and bad.
A Beech 23 pilot had planned a fligh t to an
o utback strip a nd calculated that he should land
by 1859 hou rs local. Last light, which he
obtained before the flight, was 1909 hours. Dust
and smoke h aze were forecast for the
destination.
As the Musketeer approached its destination
the p ilot noticed that the setting sun was
abnormally red, which indicated that a significant
amo u nt of smoke and dust haze was indeed
A grazier had d e parted his homestead strip Point A - at 0605 hours local to fly to Point B
about 100 ki lo me tres away wh ere he had to check
water supplies fo r his stock. He did not expect to be
away long and before departing had load ed a bull
into a truck inte nding to transpo rt it to another
paddock immedia tely on his 1-eturn.
On depa rture from Point A the aircraft's po rt
fuel ta nk gauge was reading hal f full a nd the
starboard just under half. The pilot soo n found
that the cl oud e n route was such th at at 4000 feet
he was VM C on top. After almost reaching Point B
he decided h e would have to turn back towa rds
Po int A if he we re to gel under the cloud. In the
event he h ad to fl y p ractically all the way back to
Point A before he could descend safely a nd track
again towards his d estination . He finall y landed at
Point B al 07 15 hours foll owing a flight of 70
m inute s - a bout 40 minutes mo re than he had
anticipa ted .
T hings did not p roceed as smoothl y at Po int B as
they migh t h ave. T he p ilot was conce rned about the
delay a nd m atters were not helped when , o n his
way back to the aircraft, his mo tor bike slipped on
10 I Aviation Safety Digest 116
gravel and h e fell off. He could no t resta rt the
machine and had to walk the last kilometre to his
aircraft. He was by now three hours late r than
usual for this j ob an d was concerned that his wife
wo uld be \\·orried. T he matter o f th e bu ll in the
truck was also becomi ng urgent.
Altho ugh there was a drum of fuel at Poin t B the
pilot did no t conside r usi ng it a nd took off with the
ga uges reading on ly one q uarter ful l. Abo ut 10
minutes fro m Po int A he was ala rmed when he
no ticed that the starboard ga uge was now indicatin g
e mpty while th e po rt was flickin g between a positive
indicatio n an d em p ty.
Because h e was close Lo his d estina tion the p ilot
d ecided to continue rather than carry out a
precautionary landing. Wi th the strip in sight he set
himself up fo r a straight in approach , maintaining a
low a pproach speed and using power a nd flaps
because of the shortness of the strip. At about 200
fee t on final app1-oach the engine stop ped abruptly
a nd without warning. I n the ensuing la nding sh01-t
o f the stri p the aircraft was substantially d amaged.
(continued on /Jage 11)
More than meets the eye
present. The degradation of visibility cau!>ed by
the haze was exacerbated by the shadows cast by
hills in the area. When only about I 0 nautical
miles from the landing strip and with around 10
minutes remaining before last light, the pilot
realised that conditions were deteriorating so
rapidly that he would not reach the airstrip in
time to land safely.
The pilot thus found h imself in a potentially
hazardous situation because of a poor decision he
had mad e during preflight p lanning. He later
commented: ' In hindsight I realise how foolish I
was to allow only 10 minutes before last light
seeing there was smoke and d ust haze forecast'.
To his cred it, the pilot did not try to press on
to the strip , even though it was only five or so
minutes away. Having realised h is original
mistake and assessed the circumstances, he opted
for a landing on a nearby dirt road, which he
effected uneventfully in satisfactory ligh t. In the
pilot's words again: ·1 was conscious of the
importance of making a decision to land while
there was enough light to do so safely - and
sticking to that decision'.
Comment
As this pilot subsequently admitted, his original
decision to attempt the flight was wrong.
However, having made that mistake, he did not
try to justify the decision by pressing on in an
effort to reach his destination when, clearly, to
have d one so would have p u t his ai rcraft an d
passengers at risk. His action in landing on the
first su itable area while daylight remained was
the right decision at the right time •
ccontinw,dJ
T he o n-site investigation revealed that the ai rcraft
had run o ut of fu el. Th is was, however, only one of
the causal factors, which were idemified as follows:
• T he flight fro m Point A to Point B had been
extended because o f weather.
• A furthe r delay occurred because of the motor
bike accide nt.
• T he pilot had an u rgenL job to com p lete at
Point A a nd was a lso concerned that his wife would
be worried by his late ness.
• A check of the fu el remaining in the aircraft
was not carried ou t prior to takeoff from Point B.
Fu rther, th~ p il ~t stated tha~ he C?mpletely f01·got
ab~u t t he cl1ve rs1o n on the first fl ight which had
serio usly de ple ted his fuel.
• The in fl ight decision to con tinue to Point A
eve n_whe n bo th fuel ga uges were indicating e m pty
was inconsisten t with the ci1-cumstances.
• A short-field approach was demanded because
of the strip length .
• T he e ngine fai led due Lo fuel exhaustion.
• Beca use the aircraft was in a short-field landing
configuration, it could not reach the strip.
• The forced-landing area used (over which the
pilot had little control) was unsuitable.
Comment
There was, then, much more to this accide nt than
initiall y meets the eye. Preced ing the fuel starvatio n
o f the engine was a chain of 'hu man factors' whic h
precipita ted the accident.
The kinds of pressures and stresses to which this
pilot was subjected - some of which he generated
himself - will be familia1· to most, if not all,
readers of Aviation Safety Digest. They arise from
no rmal h uman emotions and are presented in this
article, not to criticise the panicular ind ivid ual, but
rather to illustrate to all readers the importa nce of
recognising situations in which stresses are allowed
to build u p to the extent that they cloud one's
judgment. Pilots must be keenly aware of th is and
be read y to 'back-off, relax and 1-elieve those
pressures before they become dangerous •
Aviation Safety Digest 116 I 11
�lnflight structural damage
Few emergencies place a greater demand on a pilot's judgment, and capacity to assess calmly all the
points for and against possible courses of action, than inflight structural damage.
Pilots unfortunate enough to find themselves in this
predica ment sometimes experience difficulty in
deciding on a cou rse of action because of
uncertainty over the extent of the damage. T his
doubt can a rise when damage is not visible because:
• it simply is not within the field of view, or
• it is beneath the skin of the aircraft.
Structural damage can be caused by a range of
occurrences - overstress , wire strike, mid-air
collision, bird strike, aircraft components coming
loose in flight, ground/ tree strike and heavy
landings are some that come to mind. The crucia l
question the pilot must as k himself after such an
occurrence is: how quickly should I get the aircraft
on the ground? T his was a question two Australian
pilots h ad to answer recently in separate accidents.
*
*
*
T he first was a highly experienced cropduster who,
when flying under powerlines, struck them with his
a ircraft's fin. The pilot must have been welJ aware
that the aircraft had sustained a wire strike for
immediately afterwards a witness noticed the
rudder and elevators being checked very positively
for freedom o f movement and effectiveness.
At this stage the pilot had three options for
la nding. He could have landed straigh t ahead into
the crop, but with the considerable risk of
overturning . As his aircraft apparently appeared to
be responding to control inputs, that option
probably - and reasonably - did not seem like
much of a choice. Second, the pilot could h ave
landed on a dirt road which ran parallel to his final
spray run and was some 100 to 150 metres to his
right. This road was clear of obstructions and
suitable for land ing. Finally, the pilot could have
attempted to return to his base airstr ip, which was
about six kilometres from the scene of the
wirestrike.
By the time the pilot h ad tested the flight
controls a nd h ad time to assess his situation , he h ad
flown about two kilome tres from the wires towards
th e base strip a nd so h ad only about four
kilometres to go to· reach it. Thus it was probably
reasonable for him to expect the aircraft to keep
flying and r each that strip. T ragically, it did not.
While the a ircraft was still a bout four kilometres
from the strip it overflew three witnesses, one of
whom saw the vertical stabiliser fall over to the
right a nd start flap ping. All three could hear the
noise of the flapping above the sound of the
engine. Shortly afterwards the aircraft's nose
dropped and the m achine dived into the ground.
T he pilot was killed. There is little doubt tha t the
d a mage to th e tailplane caused longitudinal control
problems which resulted in loss of control and the
subsequent crash .
*
*
12 I Aviation Safety Digest 11 6
*
The second incident involved a helicopter which
" ·as e ngaged in cattle mustering. T he pilot was
hovering into wind behind a mob of cattle, assisting
in getting them into the muster yard, when a cow
broke away a nd ran behind the aircraft. As the pilot
turned o ut of wind to try to Stop the COW , the tail o f
the helicopter hit the gro und. T he p ilot felt the
thump and noticed that the aircraft had started to
vibrate. He thought that the h elicopter tail rotor
guard had struck th e cow and assessed that the
vibration was not serious. He immediately landed ,
\\"aved to the driver of a utility truck who was
assisting him to continue to bring the cattle into the
muster yard and then took off to fly over a fence to
clear the yard. When the helicopter ~\'as abou t six
feet off the ground and passing over the fe nce, the
vibration stopped, tail rotor d ri ve was lost and the
helicopter started spinning. The pilot closed the
throttle a nd attempted a hovering autorotation. He
stopped the spin but was unable to prevent the
aircraft from touch ing down wh ile still moving
rearwards at several knots. Damage to the
helicopter was substantial.
*
*
*
Tail section of the aircraft. Note the prim ary and secondary failures of the fin. Horizontal stabiliser and elevato r damage was caused
by ground impact.
It is not possible to make categorical statements
concerning the actions pilots should take in
situations such as these; indeed, it would be wrong
to do so. T he re are man y factors which come into
play - for example, in the cropd uster's case, how
was he to assess the res pective merits of a
hazardous straight-ahead lan ding into the crop,
against that of remaining airborne in a machine
which may have sustained only su per ficial damage?
A landing on the road alongsid e the crop may
perhaps have been a different matter - then again,
the pilot was only a couple of minutes flying time
away from his preferred site .
In the final analysis only the pilot can assess the
relative risks of con tinued flight in an aircraft which
may have su stained structu ral damage. One thing,
h owever, is certain : if a sa fe landing area is
available and is utilised then those risks h ave been
removed. It is infin itely prefera ble to assess possible
structural damage from ground level •
General view of the wreckage. Muster yard can be seen on left, hessian-covered fence in backgroun d. Approximate p oint of initial
ground impact is arrowed.
Aviation Safety Digest 116 I 13
�Stay with your aircraft
The Visual Flight Guide discusses hints for survival
for pilots who are forced down. The first
paragraph is headed 'Stay with your Aircraft' and
advises pilots that, under most circumstances, their
best chance of survival if they find themselves in
this potentially hazardous situation is to stay with
their aircraft. As the VFG points out, it is much
easier for air search observers to spot an aircraft
than a walking survivor, even if that aircraft is no
longe r in one piece . The VFG also mentions those
circumstances under which pilots could reasonably
consider leaving their aircraft.
In the past year there have been two instances of
pilots leaving their aircraft in harsh and remote
areas, in circumstances in which there is little doubt
that they would have been much better advised to
have remained with their machines.
• Unable to find an outback landing strip, unsure
of his position, running low on fuel and with last
light approaching, the pilot prudently elected to
land on a suitable gibber flat. The landing was
uneventful and the pilot advised Flight Service that
he was safe on the g round with sufficient water,
rations and warm clothing to see him through the
night. Although uncertain of the pilot's exact
location, SAR authorities had a good idea of his
general position and, as there obviously was no
immediate problem, arrangements were made to
despatch search parties early next morning. The
pilot was advised via radio that he should activate
his ELB at 0800 hours the next morning if help
had not arrived by then.
The downed aircraft was in fact found at 0904
hours, about 15 kilometres away from its original
destination. There was no sign o f the pilot while the
ELB, which was still in the aircraft, had not bee n
activated. Ten minutes later, the pilot was found
walking away from the aircraft along a track:
14 I Aviation Safety Digest 116
although he was not certain, he thought the track
would probably lead him to his destination.
As well as leaving the ELB behind and
unactivated, he did not have any provisions with
him, even thou gh there was water in the aircrafl.
• Flying over semi-desert terrain with few
featu res suitable for navigation, the pilot of a
helicopter became losl. When low fuel forced him
to carry out an uneventful precautionary landing, it
was well past last light. He had seen some ligh ts
which seemed to be nearby as he was landing and
so he almost immediately set out to walk to them.
He took neither '\later nor his ELB and did not
have a compass with him. As he was operating
NOSAR NO DETAILS a SAR ale rt was not
initiated by the Department's Search and Rescue
Service. A SARW ATCH was being maintained by
the o perating company, but the pilot made no
attempt to advise them of his difficulties via radio.
As the pilot walked towards the lights they
changed in intensity from bright to dull, appeared
to move and eventually disap peared. Nevertheless
the pilot kept walking for some time before finall y
camping for the night.
Next day he continued walking, keepi ng his face
into the wind , which he thought was stead y from
the west and which he believed would ensure that
he maintained a constant direction. The operating
company had by that stage re ported the pilot as
missing and, during the day, six fixed-wing aircraft
and one helicopter searched for him. Sixteen fixedwing aircraft, including two from the Department
of Aviation and one RAAF Orion, were allocated to
the search for the following day. The pilot was
found at about 0900 hours, some 12 kilometres
east-sou th-east of his helicopter.
In both of these instances it is difficult to
rationalise the pilots' behaviou r in walking off into
desert country without any survi val aids, and
indeed, having abandoned equipment and
provisions that might have been crucial in what
we re potentially life-or-death situations. One
suggestion is that such seemingly inexplicable
behaviour stems from a pilot's mental state after
successfull y executing a precautionary landing: with
the press u1-e of the emergency relieved, the pilot
may not appreciate the possible danger represented
by his environment. Whateve r the reason, pilots
finding themselves in this predicament must make
every effort to assess their circumstances calmly and
rationally. As far as leaving the aircraft is
concerned , they will be better placed to evaluate
the ir chances if they are awa re of some
fundamen ta l factors affecting survival.
Hazards to survival
There are seven factors which are generally
recognised as presen ting the m<-Uor hazards to an
individua l's capacity to survive in a hostile
environment. ln the context of' this article, readers
should consider these hazards in relation to
attempting to walk to safety.
• Thirst
• Hunger
• Extrem es of temperature
• Fatigue
• Loneliness
• Boredom
• Pain
It seems reasonable to suggest that by leaving their
aircraft, the pilots involved in the two incidents
described above we re substantially increasing thei1susceptibility to at least the first four of these
hazards.
Aviation Safety Digest 116 I 15
�Emergency locator beacons: valuable
safety aids
Requirements for survival walking
T he re are five basic requiremen ts for survival
walking. If an y one of these cannot be fu lfilled you
should not leave yo ur aircraft unless there arc
pressing reaso ns for you to seek assistance
immediately.
• Know ledge of whe re you are and whe re you
are going. If you do not know where you have
landed you can rarely plan a route to safety.
• A means of setting and maintain ing d irection.
If you have a hand compass and know how to use it
you sho uld be able to maintain a planned d irection.
T he stars and the watch-and-sun method may also
be used to hold a course. If yo u cannot use any o f
these tech niques, then to set off for an uncertain
destinatio n is asking for trouble.
• Physical capacity. Most people are inclined to
over-estimate their p hysical capabilities. A good
level of fitness for recreational activities will not
necessarily translate into an ability to traverse
dema ndi ng and hazardous terrain in extreme
weather cond itions.
• C lothes make the man. This is certainly true
when surviving, for proper clothing can mean the
d ifference between life and death. It not only
affords p rotection against the elements, but also
against the potentially serio us danger presented by
insects. Adequate footwear is perhaps the most
importan t item of clothing. Wet socks or
uncomfortable shoes can cause grave discomfort
and may com pletely incapacitate an individual.
Unless your clothing is sufficient to protect you
from any cond itions you may encounter - sit and
wait!
• Food , water, fuel, shelter and sig nalling
equipment are all crucial to survival and location.
T he likelihood is that these items will be most
readily available at the aircraft.
Summary
Unless there are p ressing reasons to seek assistance
immediately, p ilots who are forced down in a
remote area will almost invariably have the best
chance of survivi ng if they remain with their
aircraft. Any impulse to set off on foot sho uld be
resisted until a calm, ratio nal assessment of the
p revailing circumstances has been made. T he odds
are th at an y such assessment will d ictate staying
with the aeroplane. •
16 I Aviation Safety Digest 116
•
It sounded a bit li ke a siren - an urgent,
beckoning, undulating signal. It was weak at first
but as the searching aircraft swept in low over the
mountains, it grew louder, more demanding.
The pilot rotated the VHF frequency selector
from 121.45 to 121.40, then to 121.35 and 121.30
as the signal strength increased. As the signal
reached its peak, he turned briefly towards the
observers and called above the engine noise, 'On
top now'.
Eyes searching the thick treetops below, one of
the observers reported the split-second flash of an
orange object on the ground.
A second pass and they all saw it - a man
standing near a plastic groundsheet with an
electronic device propped up nearby.
T his was the first introduction of some of the
observers to an Emergency Locator Beacon (ELB)
in operation.
The occasion was a field simulation exercise part of an Assistant Search and Rescue Mission Coordinator's course run by the Department of
Aviation's Natio nal Search and Rescue School.
Air Traffic Controllers, Police, Military and
Australian Coastal Surveillance Centre staff had set
out independently in four aircraft to find a light
aircraft 'downed' in treacherous, heavily-wooded
mountains on the sou thern NSW coast.
It was a scenario witnessed many times in real life
aro u nd Australia each year.
Even though there is a high success rate with
searches for missing aircraft, not all end as happily
as in this exercise where all four searching aircraft
fo u nd the target.
Sometimes the area of probability is so huge,
information so scarce and the geography so
inhospitable that there is little hope of finding
anything in a visual se~rch.
There was no doubt that activation of an ELB
was a critical factor in finding the 'missing' aircraft
and its crew so quickl y in the exercise.
The Department of Aviation's Search and Rescue
Organisation is a strong advocate of ELBs being
included in the safety inventory of all aircraft.
Although ELBs a re not compulsory equipment
for all types of operations, the Departmem
recom mends their carriage by all aircraft in
recognition of the fact that the correct use of these
beacons can contt·ibute greatly to saving lives, as
well as to reduction of the duration and overall
effort of searches.
Whe n p roperly used, an ELB allows the size of
the sea rch area to be reduced quickly. Search
activity can then be concentrated, and the
probability of survivors being speedily located and
rescued is greatly increased.
Use of the ELB
A special study by the US National Transportation
Safety Board indicates that life expecta ncy of
injured crash survivors decreases by as much as 80
per cent in the first 24 hours following an accident.
This is a good reason in support of early ELB
activation.
Apart from complying with operating instructions
for the use of ELBs, the following advice is offered
to aircrew should they ever be the subject of a
search:
• Know how to use ELBs.
Review the operating instructions for the beacon,
and the instructions in the AIP or th e VFG relating
to its activation.
• Do not be reluctant to use your ELB.
There have been cases, some recent, in wh ich pi lots
equipped ·with ELBs have not used them even
tho ugh they were in a distress situation and an air
search was being conducted f01- them.
• Ensure that the battery is fully charged.
I n one incident an aircraft made a p1·ecautionary
landing in the Outback because the pilot was
unsure of his position. He activated his £LB soon
afterwards to help guide rescue aircraft to the
scene, but, because the batteries in the ELB had
run down, searching aircraft had great difficulty in
picking up the signal and were unable to d etermine
his position. Note the date of battery installation to
help assess batte ry condition - replace the batte ry .
regularly.
• Carry out regular ELB efficiency checks.
For their own safety and that of their passengers,
pilots should ensure that the e fficiency of their ELB
is regularly checked by an appropriately qualified
LAME. If the pilot suspects that his £LB may not
be up to standard , a test transmission may be made
utilising the aircraft's receiver, or that of anothe r
aircraft. In such cases the proper procedure should
be followed, a nd the transmission time kept to the
absolute minimum.
• Notify the Departmen t before conducting ELB
tests or in case of inadvertent operation.
Advise you r nearest Airways Operations Unit if you
wish to carry out an ELB test. You may save a lot of
headaches later. It should be remembered that,
unless it is known that an £LB test is taking place,
any ELB signal detected immediately results in the
declaration of a distress phase and the
commencement of search and rescue activity. T his
is also true of inadvertent activations and could
mean the unnecessary scrambling of aircraft and
crews, at great expense, only to find out it was a
false alarm. If you become aware that an ELB was
activated unintentionally, please advise the
Department.
(Continw·d on pag1• 18)
Aviation Safety Digest 116 I 17
�The following list of ELBs approved by the Department of Aviation was current at the time this article was written:
Manufacturer
Type
Buoyant Survival Beacons
Burndept
Elliott Bros
Garrett Manufacturing Ltd
Granger Associates
Martech
Non-Buoyant Survival Beacons
ACR Electronics
Burndept
Emergency Beacon Corp.
Larago Electronics Mfg Inc
Martech
Martin Aviation 1972
Radair Inc
Emergency Locator Transmitters
Collins Avionics
Leigh Systems Inc
Dorne & Margolin
Garrett Mfg Ltd
Narco Avionics
Pacific Comm. Inc
Pointer Inc
Crash Locator Beacons
Garrett Mfg Ltd
BE346, BE369A
ERB-1, ERB-2
Rescu 99
142-1
EB-38
RLB-1, RLB-2
BE355, BE375
EBC 202A
LELT- 1005- AF
EB-28, EB-2BCD, Eagle N/G
Omega-1
Pulsar, Dart I, Dart II
CI R- 10, CIR-1 1
Sharc-7
(OM) ELT5-2, ELT5-2A, ELT6, ELT6C
Rescu 88, Rescu 88L
ELT-10
Alert 50
Pointer II, Pointer Portable, ELT-3000
Detailed informatio n concerning the use, des ign
and perfor mance of' Emergency Locator Beacons
(ELBs) is contained in ANOs I 03.40 to I 03.43.
The beacons - which operate on the 121.5 and
243 M H z frequencies - are strongly recommended
for carriage on a ll aircraft.
ELB is a generic ter m which covers devices
known variously as C rash Locator Beacons,
Emergency Locator Transmitters and Buoyant and
Non-B uoyant Survival Beacons.
Some ELBs are designed to be fitted to aircraft,
oth ers are portable . All can be operated manually
but some are d esigned also to be activa ted by
impact forces and others by contact with water •
In brief
18 I Aviation Safety Digest 116
Preflight briefings and post flight exchanges of experiences would not be the same without the everpresent cup of coffee. While Aviation Safety Digest would never suggest that this time-honoured
practice should cease, there is sufficient data available to indicate that consumption of beverages
and food containing caffeine should be limited.
An American survey revealed Lhat, among aircrew,
80 pe r cept consumed coffee in some form, with
about 26 per cent at the 3-4 cups per day level, l 7
per cent at 5-6 cups per day, and about eight per
cent at seven cups and over per day. Most of these
people rega rded caffeine as a safe, legal stimulant
and so d id no t have any particular concern as to the
quantity they were consuming or the possibilit)' of
adve rse effects. Yet medical evidence suggests that
consumption of caffeine should be limited.
Rescu 88A
• Pilots who hear ELB transmissions should
advise an y Airways Operations Un it by the qu ickest
means available. If yo u do not know what a n ELB
sounds like, arrangements can be made to hear one
by contacting an Air Traffic Control or Flight
Service briefing office.
Aircraft operating from un p aved fie lds may pick up
a little 'some thing extra' during rainy periods.
Recently during a brake inspectio n the wheel
!'airings were removed from a Piper PA28 which
had been using a d in runway. Each fa iring had
nearly 10 ki lograms of di rt caked inside - potential
interfe re nce with wheel rotation and brakin g. For
sustained soft-field o peration s, temporary 1·e moval
of the fairings sh ou ld be considered . If this is don e,
engineering regulation s, and th e effect of removing
the fairings on weigh t and balance, must be ta ken '
into accou n t •
Caffeiq_e and flying
Ju mping the battery to start the engines led to a
complete e lectrical fa il ure in a Twin Comanche on
a n IFR flighL. T he p ilot fo und hi mself 'in the d ark'
as the gear came up after takeoff. Fortunately he
was able to remain VFR and recover safely.
A low-ch arge bauery a nd an alternator are a bad
combi nation . The alternator field is normally
excited by batter y power, but if the batter y voltage
is less than 50 per cen t there is no output from the
alternato r . A generator is self-exciting and will
recharge a weak battery •
The effects of caffeine
Caffeine is described as non-adaptive, i.e. regular
use does not diminish its stimulatory effects. It is
not p hysically addictive in the sense that withdrawal
will ha r m the user o r produce violent symptoms. It
does, however, seem to be psychologically addictive
and not easi ly discontinued. Some tolerance is
evident in that it takes mo1·e to gel the same effect
with continued use. T he following are key
descriptive characte ristics:
• An tidepressant
• Stim ulant
• Maintains wakefulness
• Affects the tone of muscles by its effect on the
ne r ve cells that control them
• Causes increased peripheral blood flow by
dilatio n of blood vessels, and derrn1sed rf'l'ebral
blood flow
• Does not significantly affect objectively
measured imellectual performance
• Does riffPet speed of accompli..1/w1en/ of motor tasll~
sign ifita ntly
• Tolerance is slow to develop and slow to
disappear (may require more than two momhs
of abstine nce)
Following on from these characteristics, there is a
list of symptoms which have been attributed to
regular consumption of large doses of caffeine and
wh ich, if ma nifested, should lead you to think
seriously about your intake of caffeine:
• I nsomn ia
• Sense of dread , d epression
• Anxiety
• Fatigue
• Loss of balance
• Faulty thinking
• Finger tremor
• Increased reaction time
Clearl y, the m<tiority of those symptoms would be
har mful to safe fligh t operations.
Common sources of caffeine
The table below lists the most common sources of
caffeine and their caffeine content measured in
milligrams per 'six ounce' cup:
• Regular coffee
100 mg/cup
• Instant coffee
60 mg/cup
• Decaffeinated coffee
3 mg/cup
• Regular tea
75 mg/cup
• Instant tea
30 mg/cup
• Cocoa
6-40 mg/cup
• Cola
60 mg/cup
For regular coffee the method of preparation can
cause considerable variations in strength, as the
following table shows:
• Automatic
15 mg/cup
• Dripolator
142 mg/cup
• Electric percolator
104 mg/cup
Research suggests that the sources from which
most people get caffeine are, in order of priority,
coffee, tea and cola. Because some caffeine is
routinely removed during the processing of all
coffee, the s11.·eatest to the least amount of caffeine
among the various forms of coffee can be listed as
follows:
• Regular
• Instant
• Decaffeinated regular
• Decaffeinated instant
Summary
Pilots should realise that coffee is not a harmless
beverage that can be safely consumed in unlimited
quantities, and that consumption of more than four
cups per day or over 400 milligrams in a 24-hour
period could cause undesirable physiological effects.
It should be noted that, because of its prope11:ies as
a stimulant, coffee can serve a useful purpose when
moderately consumed on occasions during which
optimum vigilance is demanded. On the other
hand, over use has been reported to cause loss of
balance, decreased cerebral blood flow and slower
reaction capabilities; while excessive consumption
after a flight might impair adequate rest and
contribute to unnecessary fatigue on the next day's
flight.
All individuals associated with aviation should be
aware of the possible hazard of using too much
caffeine. Moderation has generally been regarded
as an important rule for most practices, so if you
arc experiencing any of the adverse physiological
symptoms detailed in this article, then it may well
be that you need to review your consumption of
caffeine •
Aviation Safety Digest 116 I 19
�Engine fires in flight
It has been observed during flight tests conducted in multi-engine aircraft over the last few years,
that a significant proportion of pilots believe the safest method to secure an engine in the event of
fire is to turn off the fuel and allow the engine to consume the fuel remaining in the supply lines
before shutting it down and feathering the propeller. Some even advocate selecting maximum power
and full rich mixture to reduce the running time of the engine after the fuel has been selected off! The
aim of this article is to correct these improper beliefs.
For a fire to occur three basic ingredients are
essential: fuel, oxygen and a source of ignition.
Once a fire has started it must be de prived of either
fuel or oxygen to extinguish it.
In an aircraft, possible fuels for a fire are: e ngine
fuel and oil , d e-icing fluid , hydraulic fluid , e lectr ical
insulatio n, rubber and synthetic seals, plastics, tyres,
some metal alloys, etcetera.
Possible sources of ignition in a normally
operating engine are the exhaust system and
tu rbocha rger . If malfunctions occur ignition for a
fire could result from e lectrical and ignition system
fau lts, exha ust gas leaks, etcetera.
Obviously oxygen is nea rly always present to
sustain combustion.
Consider the following hypothetical case: a typical
turbocharged e ngine suffe rs a partial failu re of the
fuel line between the engine-driven fuel pump and
the fuel control unit. Fuel is immediate ly sprayed
througho ut the rear section of the engine nacelle
and ignited, possibly by the normally red-hot,
turbocharger head shroud. Even though the
tem perature of the burning fuel probably exceeds
800 d egrees Celsius, the pilot is not immediately
alerted to the fire because the aircra ft is not fitted
with a fire wa rning system.
The e ngine continues to operate, apparently
normally, because despite the leak, there is
sufficie nt fue l still being delivered to it. After abo ut
30 seconds to a minute, the fire breaches the oil
lines to the turbocharger controller; e ngine oil is
pumped into the nacelle and also ignites. At abo ut
this point the pilot would proba bly realise that
something was wrong. The turbocha rger would
begin to malfunction , the e ngine oil pressure would
be low and the re would be smoke coming from the
nacelle with possible scorching of the cowls. In
addition there could also be malfunctions of othe r
e ngine accesso ries as they become affected by the
heat. Other sources of fuel for the fire would also
begin to ignite.
·
T here is no need to draw the sto ry to a
conclusion to recognise the similarity between it and
two actual fatal accide nts. One involved a Pipe r
Aztec near Nadzab in Papua New Guinea and the
othe r a Beech Q ueen Air near Alice Springs. Both
accide nts involved inflight structural failure caused
by e ngine fires. In both cases less than three
minutes elapsed between the pilot becoming aware
of a n en gine fire and the wing separating fo llowing
failure of the main spar. T he evidence suggested
that both pilots had initiated e ngine shutdown
without de lay. The fact that structu ral failure still
occurred emphasises the importance of
extinguishing such fires as soon as possible.
20 I Aviation Safety Digest 116
Returning to o ur hypothetica l case: conside r the
possibility that the pilot elected to shut off the fue l
and wait until the engine stopped from fuel
starvation before feathe ring the propeller and
completing the shutdown procedure . The pe riod of
engine ope1·ation after selecting the fuel off can
vary considerably between aircraft types but in most
cases will be significant when compa red with the
period between the pilot's recognition of fire and a
catastrophic failure of the aircraft.
The important point here is that every second of
e ngine operation after a fire has bee11 detected
could be increasing the severity of the fire if fuel or
oil is being pumped o ut LO feed it. Remember that
the fire may be well esta blished before the pilot is
alerted. The high temperatures associated with the
fire could have already melted fuel and oil lines.
On the other hand if the pilot immediate ly
implemen ted the engine shutdown and propeller
feathering procedures, including selection of the
fuel mixture to idle cut off, all fluid pressures
would quickly decrease and fuel, oil and h ydraulic
pumps would cease to feed combustible fluid s to
the fire . Immediate e ngine shutdown could also
preclude developme nt of the fire to the selfsustaining stage and could remove sources of
ignition which may be necessary to sustain the fire
in its early stages.
During the years 1977-8 1 inclusive there were 34
re ported engine fire incidents in Australia. Of these
none would have been aggravated by immediately
shutting down the e ngine and feathe ring the
propeller. Continuing operatio n of the en gine to
consume fuel from the system would not h ave
assisted in controlling any of the fires. In 12 of the
incide nts, however, continued e ngine operatio n
would have resulted in the increased severity of the
fire . Ten of these 12 incidents involved fuel leaks
downstream from the engine d riven pumps. Of the
remaining two, one was caused by a d efective
exhaust and the othe r by carbon build up in the
exhaust system.
It is noteworthy that most aircraft manufactu rers
who include 'engine fire in flight' procedures in the
eme rgency section o f the pilot's operating
handbook recommend e ngine shutdown as soon as
possible after a fire is detected. Only one advocates
the procedure men tioned at the beginning of this
a 1·ticle.
Although this article was prepared mainly with
consideratio n to piston-engin e aircraft, the
pri~ciples expressed apply equall y to gas turbine
e ngmes.
In conclusion remember these factors:
• An e ngine fire can exist for a significant time
before being recognised by the pilot.
• An engine fire can deform or melt oil a nd fuel
lines, accessories and structural components in a
ve ry short time. Temperatu res can reach 800- 1000
d egrees Celsius.
• Continued operation of the eng ine, even for
seconds o nl y, can ra pidly inuease the severity of
the fire and the damage it causes.
• Structural failure can occur in only a few
minutes from the start of the fire.
• In the event of an e ngine fire in flight use the
procedure recommended by the man ufacturer and
shut the engine down, quickly.
• If there is no 'engine fire in flight' protedure
in the pilot's operating handbook for the aircraft
you fl y, read this article again .
• For uncontrollable fires, forget the word
'divert' and think only of 'forced landin g' •
These photographs demonstrate the extent of damage which can occur in a very short time. The aircraft was
cruising when the pilot noticed a loss of manifold pressure followed shortly by fluctuating oil pressure. The engine
was shut down, the propeller feathered and a forced landing made at a nearby aerodrome.
The only external indication of the problem was some burning and melting of the engine cooling cowl. When the
engine cowls were opened it was found that the exhaust system was holed and hot exhaust gases had been flo wing
into the nacelle. The engine bearers had been severely affected by heat and had dropped 50mm at the front end.
Fortunately the burning had not reached a self-sustaining situation. It was almost certainly due to the rapid actions
of the pilot that complete separation of the engine did not occur.
Aviation Safety Digest 116 I 21
�Flying a heading and the lanes of entry
During the review of yet another penetration of
controlled airspace by an aircraft which was
supposed to be navigating a lane of entry, a
comment was made that: 'The big problem is that
many pilots do not plan, but charge off in a
general direction and then alter heading in all
directions trying to find the ground cues'. The
record suggests that, for some pilots, this comment
is not far off the mark.
It seems probable that because of the pressures
which often exist in lanes of entry - dense traffic,
the proximity of controlled airspace, and the
normal heavy workload associated with arrival/
departure procedures - these pilots become a little
anxious in their efforts to identify visual cues. In
their eagerness to settle into a positive track-crawl,
they forget that a successful track-crawl consists of
two fundamental components:
• frequent visual fixes, which are backed up by
• regular and accurate heading checks.
It is axiomatic that the visual fix is the crux of a
track-crawl. However, as is the case with any
navigational technique, a heading check is the basic
means of confirming your tracking information.
The following incident, involving penetration of the
Sydney CTR, illustrates the possible hazards of
ignoring heading when track-crawling.
The pilot attended the briefing office at
Bankstown to file a flight plan which involved
departing the Sydney area via the northern lane.
The briefing officer impressed upon the pilot the
importance of quickly intercepting the VFR route
(marked as 007 degrees on the VTC) and of
identifying the refinery and drive-in which are on
that VFR route about six nautical miles from
Bankstown. If you examine the Sydney VTC you
will note that there are also some gasometers about
six nautical miles from Bankstown, with drive-in
theatres both to the north and the south. The pilot
mistook these features for those on the VFR route,
headed towards them, and so entered Sydney's
CTR.
It is not hard to misidentify visual features: we
have all done it. lt is, however, important that such
errors are quickly detected. In the incident above, if
the pilot had paid due attention to his compass, he
would have realised that the heading he was flying
was over 20 degrees greater than that which, in
average wind conditions, would have tracked the
aircraft along the correct VFR route.
Further evidence that many pilots do not pay
sufficient attention to heading checks is provided
on the enlarged presentation of the western lane on
the Melbourne VTC. There have been so many
instances of pilots following the wrong railway line
22 I Aviation Safety Digest 116
in that lane that it has been necessary to annotate
the chart with the following warning:
CAUTION
Do not follow railway line heading 340° M
This is despite the fact that the two railway lines in
question diverge at an angle of about 40 degrees.
Clearly, pilots who have followed the wrong railway
into controlled airspace have paid little heed Lo
their compass.
The whole question of navigating the lanes of
entry was covered comprehensively in Aviation Safety
Digest 113, and pilots who arc experi'encing
difficulties with this aspect of flight are encouraged
to review that article. In the context of this
discussion, it is most important to remember that
flying a heading is not an answer in itself: for visual
navigation and operations in high density traffic
areas, a thorough and effective lookout for other
aircraft and for accurate visual fixes is paramount.
Monitoring your heading is not, however, a timeconsuming action, and pilots must use their
compass to complement, and confirm the accuracy
of, their visual navigation.
One final thought on heading checks. As a
general rule, anytime your heading approaches 10
degrees or more from that which you calculated
you should fly, it is time to be suspicious. You may
of course have encountered winds significantly
different from those forecast, but a substantial
heading discrepancy should also alert you to the
possibility of one of the following:
• a map reading error
• a flight-planning error (e.g. track
mismeasurement) or
• a compass error.
*
Vl hen transiting D 348
A. Turn landing lights on
B. Tra ns mit advisory coll on area frequency
C. Fly eastbound at 1500 FT } Cl d
' tt '
D. Fl y westbound at 2000 F T
ou permi ing
37' 40'
CAUTION
Do not follow rai lway line
heading 340° M
144"50'
144'40'
ME LBOURNE CTR
0-2000
Summary
Using the compass to validate visual fixes is an
integral component of track-crawling. It cannot
replace the requirement to obtain regular :md
positive visual fixes, and neither should the pilot
become fixated on his instruments al the expense of
the all-important lookout for other traffic. Do not,
however , forget the compass: it is an essential
adjunct to map reading. Pilots using entry/
departure lanes need to know the heading they
should fly before they enter a lane - indeed, this
data needs Lo be calculated during flight planning
- and they should be ready to confirm tracking
information by reference to the compass •
Jrso·
144'40'
144' 50"
Aviation Safety Digest 116 I 23
�Airspeed limitations for flight in
turbulence
An article in Aviation Safety Digest 113 describes an incident in which cargo was ejected from a
Ces~na 172 when severe turbulence was encountered during cruise. The occurrence serves to
r~mtnd us_ t~at ~urbulence can be hazardous and provides a basis for the following discussion of
~·r~peed hm1tat1ons, their significance in relation to flight turbulence and the relationship of airspeed
indicator colour markings to those limitations.
AS/ with provision for TAS in cruising speed range
instrume nt. For example, Va for a Cessna I72M is
97 knots, substantially lower than both the normal
cruising speed of about 110 knots and Vno, 126
knots. A wo rd o r caution -Va is, by d efinition , the
ma noeuvring speed al design maximum weight. At
lowe r weights the re will be a structural limiting
speed which is lower th an the p lacarded Va. Again
using the Cessna 172M as an example, the
ma noeuvring speed at an aircraft weight of 730
kilograms is 80 knots, significantly lower than the
placarded 97 knots.
With the significance of these airspeed limitations
and their relationship to normal cruising speed in
mind , consider the effects or e ncountering severe
Oi~
AS/ showing colour-coded marking system
In accordance with the con ventions on the colo ur
coding of airspeed indicators the normal operating
speed range of the aircraft is de picted on the
instrument by a gree n arc. In turbine powered
aircraft (and some ·oth ers) th e top of the a rc
coincides with a red radial line and defines the
maximum operating speed (Vmo). This speed may
not normally be exceeded in an y regime of flight.
In most piston engine aircraft, however , the to p of
the g reen arc defines a different limit, maxim um
structu ral cruising speed (Vno). Both these
ma rkings are prescribed to limit the stresses
resulting from an aircraft's gust response
cha racte ristics. While aircraft to which Vmo limits
apply may not normally exceed that speed , Vno is
not limiting in the same sense - it may be
exceed ed in smooth air. In fact, normal cruise
speed for some mode rn light aircraft is a bove Vno.
T he maximum a llowable speed for aircraft to which
24 I Aviation Safety Digest 11 6
Vno conside rations apply is the ne ver exceed speed
(Vne). The airspeed e nvelope between Vno and
Vne is colour coded yellow on the airs peed
indicator, with Vne also marked with a red radial
line.
Without conside ring othe r limitations , operations
within the green arc should, then, be safe in all
conditions - including turbule n t air. From a gust
response viewpoi nt th at may be so, but another
important limiting airspeed lies within the green arc
and must be considered; this is th e design
manoeuvring speed (Va), the maximum speed at
which abrupt or full control travel may be applied
with out risking damage to the aircraft. Not only is
Va less than Vmo or Vno, it is often less than the
normal cruising speed as well. Furtherm ore, it is
not d epicted by colour coding on the airspeed
indicator - although it is req uired to be displayed
on a p lacard as close as is practicable to the
turbulence unexpectedly a t normal cruising speed,
or of contin uing flight in severe turbulence - even
at reduced speed. According to the specifications
applied to describe turbulence severity, an aircraft
flying in severe turbulence may experience abrupt
attitude and altitude cha nges, with variations in
vertical acceleration greater than one g felt at the
centre of gravity; large variations in airspeed may
occur; occupants will be forced violently against seat
belts; loose obj ects will be thrown around and the
aircraft may be out of control for short pe riods.
Clearly, if prescribed airspeed limitations are not
understood and observed such conditions could
expose an aircraft to the risk of structural damage,
not only through the stresses imposed by the
tu rbulence, but also through those imposed by the
large control inputs which might be required to
maintain or regain control.
At low speed , however, another problem em erges
- the risk of control loss through red uced control
effectiveness and the reduced margin over stalling
speed .
To provid e a balance between the hig h and low
speed problems, a turbulence pe ne tration speed is
specified for turbine powered aircraft; however, no
such specification exists for most piston en gin e
aircraft, although the operators' h andbooks for
some types list Va as a limiting airspeed in rough
air. When n o such guida nce is g iven pilots must
remember tha t Vno is a design limit airspeed, a nd
they must be constantly aware of th e significance o f
Va. Providing control response is satisfactory at Va
a nd th ere is an ad equate margin over stall speed ,
o peration at the lower speed will provide a greater
margin of security against overstressin g the aircraft
a nd give a more com fortable ride. If a speed higher
than Va is required , or is specified for turbulence
penetration , caution should be exercised , as the
pilot has the capacity to overstress the aircraft
structu re through flight control inputs •
ain't oi~!
While incidents of n on-lubricants being added to
aircraft engine sumps have been few,
never theless they do occu r. T h e end result
almost invariably will be serious e ngine
malfunction.
• Before flight the pilot topped up the e ngine
sump with what he believed was o il from a p lain,
unmarked 44 gallon drum in a priva te ha ngar.
Soon after ta keoff h e noticed a decrease in oil
pressure and requ ested clearance for an
immediate landing after declaring an emergency.
Engine power remained available for the
approach and the aircraft was landed without
furth er incident. The pilot subseque ntly learned
that what he thought was oil was in fact adhesive.
• Shortly after takeoff the e n gine lost powe r
a nd stopped . The aircraft was destroyed during
the subseque nt attemp ted forced landing into
rough te r rain. Post-flight inspection revealed that
the pilot h ad mistakenly added syn thetic resin to
the oil sump, causing th e engine to seize. The
synthetic resin had been added from plastic
bottles, which were not originally oil container~
a nd were not labelled clearly as to their conte nts.
Contamination of lubricating systems is not
confined to the addition of the wrong fluid :
replenishing oil using d irty containers, pourers
or funnels, or during dusty weath er, can also
lead to serious consequences. As far as the
lubricant itself is concerned, the practice of using
only oils from clearly identified producers'
containers has become accepted for very good
reasons •
Aviation Safety Digest 116 / 25
�li.~m--------Up to 1·5nm--------t11J1-~1
person is low, spreading out, trying to slow down
and come back up.
3500 feel - break off - we all get the message
a nd start tracking. The formation bursts o utwa rds
as everyone looks for his ow n piece of airspace. A
quick gla nce a ro und, all clear, pull, and I am
looking up checking my parachute. The rest are a ll
open around me and we are still over 2000 feet. No
hassles with the Drop Zone Safety Officer about low
openings. I turn toward the target and fly back
downward. That was a good start to the weekend,
pity about the second formation, but we will d iscuss
it in the debrief'.
~
It is another fine Saturday morning when we an-ive
at the a irfield, blue skies, light winds and the usual
crowd.
I put my name on the m anifest board and am on
the first load.
Five of us gear up, check altimeters, pins and
practise the formations we will attempt. Climbing
into the old taildragger, the pilot calls 'clear prop'
and fires up. Taxi out, line up and we are away.
T h e blast through the open door is fam iliar and
we watch the horizon as we circle slowly up to 8000
feet.
It is nearl y jump run and everybody is attending
to last minute checks, kneeling on the floor,
tightening straps. I a m nearest. the door so I have
been elected j umpmaster. My main concern is to
find the correct exit point because if anyone has to
walk back Lo the clubhouse I will be blamed!
The pilot lines the aircraft up on my hand signals
and I watch the airfield pass undernea th us. We are
flying directly into wind now, another 200 me tres
a nd ... power off!
I climb out and hang from the top end of the
strut, another second and the next jumper is beside
me. Everyone else bunches up around the door Ready, Set, GO - we are flying.
The first formation, a star, begins to build un til
all five of us are linked in a circle - good - sh ake
and break and a quick glance at the altimeter, five
grand, plenty of time. We begin the next formation ,
everyone side by side facing opposite directions, an
accordion. Four of us are together but the last
26 / Aviation Safety Digest 116
~
Exit point
I
up to 60 sees of free fall
Thus far this sounds lihe an ideal way for a skydiver lo
spr,nd the day. There was, however, an additional.factor
which I have not y1't mentioned, and which could have
transformed an exhilarating r'xperiena i11to a tmgedy.
Vll hile n•e were climbing to ourjump hright, a small Piper
was seen flying beneath us over the Drop Zone, apparently
oblivious to the ris/{ he was p/'l'senting, not only to the
parachutists but also to himself: a rnlli~ion betwem a
shydiver free-falling at 140 km /hr and an aircraji is
almost certainly going to be a disaster.for all concerned.
As a ru le parachute clubs welcome visitors,
especially pilots; after all, they play an integral role
in the skyd ivers' sport. So, pilots, please feel
welcome to visit yo ur local parachute club, but if
doing so by air the following vital safety points must
be noted:
• If transilting near an active jump area stay at
least th1·ee nautical miles from the drop zone
(DZ), and make an 'all stations' call on the
appropriate FIS frequency , as the parachutists'
aircraft should also be on that frequency. Note,
however, that this call will not necessarily give
you right of way over parachute operatio ns.
• If landing at a DZ, contact the parachu te club
beforehand Lo find out whether they have a
discrete ground/air frequency. Stay away from
the up wind a rea of the DZ as this is the prime
traffic zone for parachutists.
• As ground panels are ofte n used by parachute
clubs to advertise their operations look for
those panels and know what they mean .
• Be aware that traffic - both aircraft and
parachmists - may be heavy; al a recent
Australian competition over 500 parachute
descents a day were made, involving several
aircraft.
• Skydivers rarel y look down a fter exit. They
look at each other, their altimeters and the
formation they arc attem pting.
So, the next time yo u notice a red parachu te on
the cha rt near you r intended flight path, remember
that it could indicate the presence of someone
em ulating an air-to-air missile. T he sky is fo r
everyone - it's j ust that parachutists don't want to
occupy the same piece at the same time as an
aircraft •
Jump run up to 12000 ft
I
I
break off 3500 ft
l
I\
I \
~IND
I
;"'
d
/
'
~
opening height 2500 ft
l
Safe to drop
Orbit aircraft
Experienced
parachutists
only
Unsafe
to drop
Land aircraft
Aviation Safety Digest 116 I 27
�
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Aviation Safety Digest, number 116 (1983)
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116
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1983
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https://collections.heritageoftheair.org.au/files/original/eb7b899d5f989207a3a59ae183fa6e6b
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PDF Text
Text
Introduction: The adve nt of digital watch technology has brought with it its own
set of problems. For example, how can pilots determine North by using a digital
watch ? Scientists have conducted extensive research on this subject, and have now
come up with a solution to the problem.
Aim: The aim of this precis is to provide a stand-by means of finding True North
for those ill-equipped ' navigators' who are frequently in need of inspiration but
rarely at loss for excuses.
••
Step one: Find the sun. This is done by looking skyward when a blinding glare,
often accompanied by pain in the eye, will indicate the direction of the sun.
Alternatively look at the ground (to find ground, see step two) a nd find yo ur
shadow. Then, keeping you rself uprigh t align the tip of your shadow (S H) with ere
top of your head (H) and slowly turn H through 3,200 mills to look along the line
SH-H-Sun.
Step two: Shadow stick. Find a straight stick and place it upright in the ground (to
find ground, look immediately be low your feet where ground will normally be
parallel to and continl!ous with the soles of yo ur boots). Note that stick (S) will cast
shadow (SH) on the grou nd (G).
,
l
•
Step three: Clock face. Refer to digital watch and ensure that time shown is correct
by either (a) checking with conventional watch owners nearby, or (b) when out in
the bush , by dialling 1194 from nearest telephone.
Then having established the time of da y, draw on ground (G) a convention al clock
face around stick (ST) using ST as pivot for clock hands not normally shown on
d igital watch. Onto representational watch face draw in the h a nds of conventional
watch at correct time of day as per d i gi~al watch.
Step four: Aligning clock face. Align the figure 12 on clock face with sun (S) by
rotating ground (G) around stick (ST) until figure 6 coincides with shadow (SH) to
achieve the alignment 6-SH -ST-12-S.
•
Step five: Find North. Draw a line on the conventional clock face from pivot (P) to
a point mid-way between 12 o'clock (12) and the hour hand (H).This lin e, P-(12H) should indicate North. If in doubt, firmly close your eyes and spin arou nd until
you feel dizzy and fall down, whereupon rising from the ground (G) there is at
least a chance that you will be facing North (N) .
Finally: If all else fa ils, remove digital watch from your arm and swing it a round
overhead AND LET GO. Your digital watch will then have 'Gone West' in which
case True North is probably over your righ t shou lder.
Instructors note: Finding North by digital watch is to be regarded as 'confidential
information' and should only be taught to pilots who are a d vanced in map
reading•
(C1J11rt1·s)' RAAF SpuLligln)
�Unsurveyed landing area
Contents
3
Unsurveyed landing area
The pilot of a Cessna 172 attempted to land at Lake Eyre
at the request of his passenger, a professional
photographer. The nosewheel sank to a depth of 30cm and
the recovery of the aircraft presented considerable
difficulties.
4
When you're outa gas ...
Investigations into fuel exhaustion occurrences usually
reveal either failure to check the tanks before flight or lack
of understanding of cruise control procedures and fuel
management.
6
The myth of the accident prone
Psychological research in the U.S.A. suggests that all of us
enter the high-accident-risk category when under stress.
7
7
Door open in flight
Strobe lights and ELBs
There have been two incidents recently in which faulty
strobe lights on aircraft have generated signals similar in
tone to an ELB emission.
8
10
12
The maintenance release
Haste and lack of systems knowledge lead
to gear-up landing.
Engine fire during start
The Pilot's Operating Handbook for the aircraft type and the
Operator's Manual for the engine should be regarded as
authoritative references.
15
Unless otherwise noted, articles in this publication are based on
Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 18390. Melbourne, Vic. 3001.
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries and notifications of change of address should be directed to:
Mail Order Sales,
Australian Government Publishing Service,
P.O. Box 84, Canberra, ACT 2600.
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Reader contributions and correspondence on articles should be
addressed to:
Pilot contribution
An account of a near-collision between a Cessna 172 and a
Fokker Friendship at an uncontrolled aerodrome.
14
Aviation Safety Digest is prepared by the Bureau of Air Safety Investigation in pursuance of Regulation 283 of the Air Navigation
Regulations and is published by the Australian Governmen.t Publishing Service. It is distributed free of charge to Australian licence
holders (except student pilots), registered aircraft owners and certain other persons and organisations having an operational interest
in Australian civil aviation.
A chain of circumstances
The pilot of a Shrike Commander abandoned take-off when
the engines failed to give full power. The aircraft had been
refuelled with turbine fuel instead of avgas.
16
Cockpit etiquette
17
Observe your authorisation limits
The Director,
Bureau of Air Safety Investigation,
P.O. Box 367.
Canberra City, 2601
'·Commonwealth of Australia 1983,
RM79 /30212(4) Cat. No. 82 3243 1
Printed by Ruskin Press. 552-566 Victoria Street, North
Melbourne, Victoria.
A practice forced landing ends in disaster
18
Survey of accidents to Australian civil
aircraft 1980
20
Mast bumping in helicopters
22
Hazardous attitudes
22
Churchill Fellowships
23
Danger! Aerosol cans do explode
24
How to find digital north.
Front cover
2 /Aviation Safety Digest 115
As the Bureau of Air Safety Investigation is currently in the
process of relocating its Central Office from Melbourne to
.
Canberra this issue's cover features a photograph of operations
at Canbe~ra. Civil operators share the airport with the RAAF, and
here a Beech Baron from the locally-based VeeH Aviation is
pictu red with an RAAF Iroquois ~elicopter. Enth~siasts will have
little problem in identifying the aircraft on short finals.
(Photograph courtesy of RAAF)
0
Right view of aircraft. Note how the nosewheel has dug in.
A Cess11a 172 tlo\\'n by a comme rcial piloL had been
hired by a professio nal photogra phe r Lo carry o u t
aerial phoLograph y over ce ntra l Australia. A fter
severa l un even tful sorties a lligh L was conducLed
uve1· Lhe Simpson Desert and Lake Eyre North . The
ae rial photogra phy presented no difficulties, but
the p how grapher the n asked the pilot if it would be
possible to la nd o n La ke Eyre Lo take some groun d
shots. Th e p ilot selected the whitest area, which he
beli eved wo uld be the ha rd est su rface, a nd lle" ·
over it al abo ut 50 fee t. The surface looked
satisfactor y. I le had a lso been w ld a t one o f his
staging poi nLs Lhat Lhe re had bee11 11 0 rain at Lake
Eyre fo r two yea rs a nd this, togethe r with his
airborne inspection , led hi m to conducle that it
wo uld be safe to land .
Weathe r condiLions we re fin e as the pilot Lo uched
down gently in to a ~ O knot head wind . He had
asked his passenge r to mo ni tor \\' heel pe netraLion
of' the su rface. I nitiall y the surface seemed firm but,
as the a ircraft d ecelerated, th e wheels started to d ig
in sligh tly. Just as Lhe pilot d ecid ed Lo initiate a goa round at abo ut 40-50 kno ts, Lhe main wheels
d ragged more heav il y and fo rced the nosewheel
through the su rface of the la ke, eventually to a
d epth o f a bout 30 cenlimetres. T he aircraft rolled
o nly abo u l seven me lrcs after th e nosewheel du g in
befo re the prope lle1· slruck Lhe surface, stopping
t,hc e ngin e. Althou gh subsequent examination
revealed o nl y supe rficial damage to the a irc rafl, its
recover y prese nted rnnside rable d iffi culties.
Because there was no body o n the ground to
assess prope rly the suitability o r Lh c area, the pilot
\\'O tild have been wise to have d eclinecl the
pho togra pher's request to la nd. Afte r the incide n t
the pilot surveyed a lar ger area of the la ke and
fou nd Lhat while the re were some hard a reas, Lhe
surface generall y was soft to a d e p th o r about l 0
centimetres. This incident, like previo us simila r
occurrences, showed that the on ly safe wa y Lo assess
a p roposed la ndi ng area is fro m Lhe groun d, and
tha t a low-level fl ypast is no substitute fo1· a
tho rou gh ground-level survey.
O n Lhe credi t side of the ledge r , the pilot's safety
pla nning for th is trip deser ves me ntio n . H e had
pac ked light ca mping equipme nl, a good suppl y of
food a nd waler , and Lhe aircraft was fitted with a
serviceable ELB - a ll wise p recau tions given the
te n a in over which he was opera ting •
Aviation Safety Digest 115 I 3
�When you're outa gas .
•
•
Good airmanship and regulations alike dictate that a pilot ensures he carries sufficient fuel to
get him to his destination and still have a bit in reserve. Yet not all do this: an alarming
number of engines fail simply because they 'ran outa gas'.
Investigations into fuel exhaustion occurrences
often reveal that the reason, when reduced to the
simplest terms, is that the pilot did not look in the
tanks before flight. It would be easy to stop there
and point the finger; however, the question why
often reveals pressures that induce pilots to omit that
last-chance check. For example, how many of us feel
self-conscious about opening the caps to check when
the refueller h as just closed them , or when an
instructor or friend has assured us that there is
plen ty of fuel in the tanks? It is so much easier to
simply check the gauges. However, fuel gauges in
many ligh t aircraft are insensitive to changes in fuel
quantity at near-full tanks; many are limited in their
accuracy; and most are affected by a ircraft attitude.
As this account of a fuel exhaustion accident attests,
reliance on the gauges alone to validate assurances
or assumptions is most unwise.
The pilot had pla nned a sight-seeing holid ay to
Central Australia. She had held a private licence for
a little less than two weeks a t the time and had
accumulated about 80 hours flying experience. After
subm itting a fl ight plan for the first day's flying, she
went to the operator's lounge to complete her
prep aration , where she was advised by a staff
instructor th at the aircraft was ready and that it had
been refuelled to full tanks. She accepted this
information without visually checking the tanks,
claim ing later when she requested a ladder to do so
the instructor again insisted that the ta nks were full .
During her daily inspection the pilot checked the
fuel gauges and believed that they did indicate full
tanks.
T he flight that day was to be conducted in three
stages without refuelling. T he planned flight time
was 206 minutes and an endurance of 360 m in utes
was recorded. T he first stage of the flight and the
landing were uneventful , as was the second stage,
but the pilot decided to continue to her overnight
destina tion without making the planned second
landing.
When about 20 minutes into the final stage she
looked at the fuel gauges for the first time since
4 I Aviation Safety Digest 115
departure for the second stage of the flight - a
time interval of some 85 minutes. They indicated
empty. Shortly afterwards, the engine failed and the
pilot was committed to a landing on unsuitable
terrain.
The engine had failed 't hrough fuel exhaustion
after a total engine-on time of about 216 minutes.
Investigation revealed that, contrary to the
assurances given to the pilot , the aircraft had not
been refuelled. It had in fact not been refuelled
since it was flown by this same pilot five days
previously.
This account has illustrated the danger of placing
total faith in the assurances of others and the
accuracy of fuel gauges. But it has also shown that
the gauges - with all their faults and inaccuracies
- are still a useful aid in fuel management. Had
the p ilot monitored calculated fuel usage against
contents indica tions, the gauges should have alerted
her to the low fuel situation before it became
critical.
* * *
Perhaps the second m ost common cause of fuel
exhaustion occu rrences is the pilot's lack of
understanding of cruise control p rocedures and
fuel management, both in general and for
particular aircraft. This next account illustrates one
such case in which an exp erienced pilot d id not
apply basic fuel managem ent principles or
understand the appropriate cruise control procedures
for his aircraft. It also embodies in the one incident
m any other factors common to most fuel exhaustion
occurrences. The a ircraft, a Cessna 210, was on
final for a n ight landing on return from a long nonstop cross-country flight when the engine failed
through fuel exhaustion.
The p ilot held a private licence with a class four
instrument rating and had considerable experience
on Cessna 210 and Bonanza aircraft. His total
aeronautical experience was about 600 hours. He
had undergone a check flight in the Cessna 210
when he star ted flying with this operator and had
hired the aircraft on other occasions prior to this
flight, but he had not previously conducted such a
long-range flight in it.
T he outbound flight two days earlier had been
conducted in two stages with the aircraft being
refuelled at the intermediate stop. The pilot did not
conduct a fuel consumption check on either of those
stages.
Before departing for the direct return flight he
had the aircraft fuelled to capacity and completed a
detailed VFR/ NVMC flight plan . He based his fuel
planning on an expected fuel now of 90 lb/ hr with
a usable fuel load of 75 gallons, from which he
calculated an endurance margin of eight minutes
over the fuel required.
After take-off the pilot was given a step climb to
his selected cruising level , 6500 feet. On reaching ., that level he leaned the mixture by setting an
indicated fuel flow of 90 lb/ hr with reference to the
fuel flow meter. He was not familiar with the use of
the EGT indicator, and did not attempt to check
the accuracy of the flo w m eter by, fo r example ,
leaning to rough running and reading the indicated
fuel flow at that mixture setting. Enroute he ran the
left tank to one-quarter by the gauge and then
switched to the right. When the right tank was
similarly down to about one-quarter by the gauge he
re-selected the left and ran it dry, getting only
another 15-20 minutes out of it.
At that point, with about 60 miles to go, the pilot
was becoming con cerned about his fuel state, but
even then he did not conduct a consumption check
by comparing ga uge readings against time and
distance gone. He only re-checked his original flight
plan calcula tions and 'hoped they were right'.
Shortly a fterwards he enquired about the availability
of flares at an ALA on track 40 miles short of his
destination. But because there was no suggestion of
an emergency in the enquiry, and because the pilot
advised that he did not intend to land there 'at this
stage', the Flight Service Officer assumed that th<>
enquiry had been made out of academic interest ,
perhaps in relation to a fu ture operation, and did
not react with any urgency. T he pilot gained the
impression there would be some delay in arranging
lights and decided to continue to his destination .
The declaration of an emergency or even a
positive statement of concern about his fuel would
have eliminated the misunderstanding, and the
incident (near accident) could have been avoided. It
later transpired th at runway lights were available at
the ALA and tha t they could have been switch ed on
in time for the pilot to divert.
Entering controlled airspace, the pilot was handed
over to A TC and cleared to track direct to his
destination . Three minutes later he was identified
and cleared to make a visual approach when ready;
however, he wisely elected to maintain his altitude
until he was sure he could make the field . T he fuel
ran out on long final and a successful forced landing
was made on the aerodrome. T he investigation
revealed that the pilot's sole m ixture control
reference, the fuel flow meter, was under-reading by
20 lb/ h r.
The chain of events leading to this occurrence
started when the pilot attempted to conduct a flight
that demanded a degree of skill beyond that
exhibited during the flight's progress. The pilot
missed the last chance to break the chain by
substituting wishful thinking for positive action when
his fuel shortage became evident to h im.
* * *
Remedies
Fuel exhaustion accidents and incidents such as
these can be eliminated. The following pointers have
been assembled from the experience of these and
other investigations , and cover most of the factors
pertaining to fuel exhaustion occurrences.
Pre-flight preparation and planning
• Understand the aircraft fuel system. Know the
usable fuel capacity of the particular aircraft and
know how to manage the system so that all of the
usable fuel can in fact be used.
• Be familiar with and use the aircraft performance
charts. Understand the conditions required to
achieve the published performance figures and be
aware of the effect of operations outside the
published parameters .
• Calculate fuel needed with regard to all known
requirements and conditions: weather forecast ,
availability of fuel enroute, holding requirements
(NOTAM and weather), fixed and variable reserves,
etc.
• Ensure by all means possible that the required or
expected amount of fuel is in the tanks,
remembering that most gauges are limited in their
sensitivity and accuracy - particularly near-full
tan ks - and may be affected by aircraft attitude;
that a visual estimate of contents is only accurate at
full tanks or at other defined levels such as are
provided b y indicator tabs, and again that aircraft
attitude may affect these readings; that dipsticks are
a reliable aid in measuring fuel quantity for most
aircraft types, but these should only be used in the
tank for which they are calibrated, and yet again
that these may be affected b y aircra ft a ttitude.
• Ensure that all fuel drains are closed and that
none is leaking after taking fuel samples .
In flight
• Operate the engine in accordance with the
handbook instructions. Adhere closely to the leaning
procedure and power settings prescribed to obtain
the published p erformance figures.
• Conduct the flight in accordance with the flight
plan. If a variation becomes necessary consider the
effect on fuel reserves.
• Apply systematic fuel monitoring and management
procedures appropriate to the aircraft type.
• Conduct fuel consumption checks regularly during
the flight and compare fuel usage aga inst progress.
If a discrepancy is indicated assume the worst case
unless normal operation can be verified.
• T ake positive action before a low fuel state
becomes critical. Adopt long-range cruise
procedures; consider climbing or descending to
another level to escape adverse winds or make use of
tail-winds; and divert early if appropriate. But above
a ll, declare an emergency as soon as a p roblem
becomes evident and while sufficient fuel remains
for you to make use of any forthcoming assistance•
Aviation Safety Digest 115 I 5
�The myth of the accident prone
How often have you heard the cause of an accid e nt
attrib uted to accident proneness on the pan of the
individua l involved ? Accid ent prone ness is a
con ve nient la bel, but it is not a cause. T he ter m
acciden t prone ness is a m isnome r , a myth. By
calling someone accident prone, you are stating that
he was born lo have accide nts, that h is he reditary
nature makes him a klu tz and tha t the re is no thi ng
that can be do ne to slop him fro m having an
accident.
T his is just p lain balderdash. Gene ticists have not
discovered a ny accid ent proneness ge nes and
research stud ies have shown lhal we ca nnol even
predicl a person's likelihood of having an acciden l
fro m his past acciden t history. But accidents can be
prevented , as will shortly be pointed o ut.
If accid e nt pro neness is a myth , why do some
people appear to have more tha n Lheir share or
accidents? T o a nswer this q uestio n let us first
e xamine the reasons why a sing le acciden t occurs.
In almost ever y acciden t, the accide nt investiga tor
is faced with a myr iad of contribu tor y va ria bles .
Ve ry rare ly is the re a single cu l-and -dried cause
factor. There are almost always numero us
contributor y va ria bles, such as poor ma n-machine
inte rface, super visory er ror , limi ted ex perie nce,
failure to use accepted procedures, task satura lion,
overconfide nce, etc. Sometimes these varia bles are
transitory a nd stress rela ted. For example, the
acciden t victim may have been suffe ring fro m some
temporary ph ysio logical variable such as fatigue,
h ypoxia, hypoglycem ia, or a te mpo rar y
psych ological variable such as boredom , a nxie ty,
fr ustration , or de pression. Environme ntal variables
such as weather also play a n impor ta nt ro le. Ofte n,
if one or more of Lhese variables had nol been
present, the individ ual's performance may nol have
been comprom ised enough to result in a h u ma nerror accide nt.
Alth ough there are several reasons why a pe rson
cou ld be involved in an acciden t, is the re a common
denomina tor a mo ng these various reasons? Some
ear ly psychological research is suggestive. A few
years ago a US avy flight su rgeon/psychiatrisl
d eveloped a psychological profile o f' Lhe hig haccid ent-risk avia tor (he acLUally used the term
accident p rone, b ~i t we now know tha t this term is
inappropriate). H owever, whe n you com pare this
theoretical profile of the high-accide nt-risk aviato r
to the psychological profile of th e outsta ndi ng
aviator, you make a very interes ting d iscovery.
Namely, the pro fil e of the ou tstand ing avia tor and
the h igh-acciden t- risk aviator have much in
common , with the exception or one very significam
factor . T he high-accident-risk avia tor a ppears to be
undergoing stress, whereas the outstanding p_ilot is
no t. Does this suggest to you tha t a n oulstandmg
aviator undergoing stress is, in acLUality, a h igh accident-risk avia to r?
T his d oes not mean th a t a ll human-error
acciden ts arc caused by stress. Wha t it does su ggest,
6 I Aviation Safety Digest 11 5
however, is that if stress is present, and if the
quan tity and/or seve ri ty is great enough , an
ind ivid ua l - a ny indi vid u al - will be more likely lo
be invol ved in an accident. Th is individua l should
not be conside red acciden t pron e, but rathe r o ne
who has cu rre ntly en tered a high -accid ent- risk
categor y. Ever yo ne al some poin t in time e nte rs th is
category. I f you alleviate the stress, yo u re-enter the
low-accident-risk categor y wh ere, incide nta ll y, the
maj ority o f us are mosl of the time.
Wha l exactly is slress? Stress is simply a norma l
'reaction of the body lo Lhe ordina ry and
extraordi nary p ressures of li fe'. T he presence of
stress initiates hormonal and various olher
physio logical cha nges, a nd can. ~au se a d rastic
im pairment in a person's cogmu ve a nd rnolo r
functioning. Re member J oe (a US Navy cartoon
characte r) a nd his p roble ms? Wha t if you knew J oe
had been un dergoing severe stress Cluring the
weeks prior to his n ume rous mishaps? His father ,
wilh who m he had a very close relatio nsh ip , had
recently und ergone a rlerial bypass surgery. J oe's
d au ghte r, in asserting he r ind ependence, moved
out of J oe's hou se, aga inst his wishes, and into a n
apa rtmen t. J oe stopped smoking two weeks ago a nd
has take n a second mortgage on his home. All these
events a re stressfu l. In the light or what has bee n
d iscussed, is it surprising thal .Joe has had a few
close calls? When the stress d imi n ishes, J oe will ree nte r Lhe low-accide n t-ris k category a nd be his old
self again .
Prevention o f strcss-rclalecl accide nls is a Lwo-step
process. Firsl, you must learn to recognise that yo u
a re undergoi ng stress, and second, yo u must take
action to red uce the stress affecting ro u.
Recognition of slress is really not a ll Lha l difficu lt,
since LhLcrc are usually accompa nying beha viou ral
changes with increased stress. T he followi ng a re
co m1~on reactio ns to stress: anxiety, prcoccu pa lion ,
impatience, hu mo urlessness, inability to
concem ra lc, resLlessness, freque nt or prolonged
headaches, unha p p iness, depression, rruslralion ,
aggression, irritability, defiance, insom n ia, and
apath y or indecisiveness. A person undergoing
stress will exhibit some but nol all of these
symptoms . The key is Lhal the stressed person is
behaving atyp ica ll y. H e is just not himself.
Red uction of stress in most cases is re latively easy
and can be hand led in one of severa l ways. Ph ysical
exercise is a n outsta ndi ng me lhod o r stress
red uction. Whether it is imense, such as playi ng
squas h, or less slrenuous, such as walking, il works
well. H obbies a nd olhe r no n-ath letic events thal you
enjoy and derive pleasure from, such as readi ng,
building mod e l p lanes, need lepoin ling, or p laying
backgammon are a lso excellenl stress red ucers.
Talking yo tn- ,problems oul with someone wh<?se
opin ion you value, o r wilh someone who w1ll .iust
listen patien tly, may be the best stress red ucer
around. lf the stress you arc encou nte ri ng is so
imc nsc Lhal these met hod s p rovide little relief,
do not be afraid to seek professional help. I t may
save your life.
In sum mary, re member that everyone (wife, pilot,
crew chief) enters the high-accident-risk category at
some ti me o r another. Entrance inlo this category is
o ften p receded by a build up of stress caused most
frequently by the eve ryday variables that upset the
*
normal routine o[ life. Consequently, when stress is
present, increased awareness and caution are
required. When you see Lhe telltalc behavioural
changes taking place in yourself or someone else,
take the necessary steps to reduce the stress and get
back to being a low-accid'em risk. And, ab9ve all,
remember the myth of the accident prone •
*
*
Door open in flight
If yo u fly a light aircraft have you ever give n any
thou g ht to wha t would happen if a door came open
in fligh t? Most operating handbooks recognise the
possib ility a nd prescribe appropriate procedures to
d eal with th e situ ation should il occur, bu t they do
not con vey to the p ilot the startling effect such an
occu rrence can have o n the aircraft's occupants.
T he sudd en rush of ai r a nd increase in the noise
level will p robably make your passenger try to climb
o nto your lap, an d your reverie will be shattered as
all sons of vision s !lash through your mind in the
instan t it takes to find ·the source or the
d istu rba nce. Then, if yo u are unsuccessful in your
attempts to close the door, you will be forced to
ope rate in a very noisy and probably cold
en viro nm ent u ntil you land. That environment can
be exceed ing ly d istt-acting, as the pilot of a PA24
rece ntly d iscoverecl.
The door popped open without warnin g as the
pilot ap proached his destination. After several
frui tless attempts to close it he advised ATC of his
problem a nd on rece iving an approach clearance
started a visua l ap p roach. He selected landing gear
clown and the n cha nged fuel ta n k selection to main
ta n k fo r land ing. H owever, on checking the fuel
*
contents indicators he discovered tha t they all read
empty. While pre-occu pied with this developmen t
he allowed the aircraft to get fast and high on the
approach. He closed the throttle and selected full
flap, but the aircraft still failed lo decele rate.
Continuing wilh the approach he executed a
sid eslip manoeuvre down to about 100 feet to wash
off the excess energy a nd finall y touched down
I 050 meu-es along the 2528 metre runway without the benefit of landing gear or flaps. T he
pilot had not noticed that they did not extend when
selected. Nor had he seen the red light directed at
him from the control towe r.
Distracted and confused, the p ilot became preoccupied with salvaging the approach and landing
the aircraft, at the expense of a rational an alysis of
what was happening around h im. Consequently, he
failed to recognise that the aircraft had suffered a
total e lectrical failure at some stage after the
approach clearance was issued.
T his pilot was taken by surprise and did not
regain his composure in time to prevent a wheelsup la nding. Would you have been any better
prepared? •
*
Strobe lights and ELBs
T h e re ha ve been two incid ents recently in which
faulty strobe lights on a ircra ft led lo the initiation
of search a nd rescue (SAR) action . The following is
a summar y o f o ne of the incident5, taken fro m the
Air Sa fe ty Incident Repor t submitted by the pilot:
W hitt' using the HF radio, I notiffd an 'ELB ' nois1'
rnming through tht' headphonl's. Aft1'r a ft'w radio du,rk~ I
fou11d the noise was wming through thl' HF radio only. I
then chl'ChNI my own ELB , whid1 was rorrntly st' frcll'd Lo
the OFF position. I nol~(ied Flight Service of the
occur/'l'llCt' and advised them that I would be landing Lo
chl't'k 111)' aircraft f or defi'rts which might bt' causing the
inte~ft.'rmct'. After landing, I t'vmtually dell'nnined that
the strobe beacon on the aircraft's Lail was causing the
ELB noist' and I notified Flight S ervice of this.
T his noise was exactly the sam1' in lone as an ELB
emission, bu t was slight!)' slower. I have flown many
aircraft on which the strobe lights have caused a 'dicking'
sound 011 the HF radio, but nt'Vt'r one with this 'ELB'
sound.
*
T he Flight Ser vice Unit involved ill' this
occurre nce had declared a dis tress phase as a result
of the repor t fro m the aircraft. The pilot is to be
commended for la nding as soon as possible and
resolving the matter, thereby releasing SAR services
which might have been required elsewh er e for a
real emergency.
A tech nical investigatio n showed that the
inter fe re nce stemmed fro m th e strobe light's power
su pply. The power supply incorporates a DC-DC
high voltage conve rte r , a nd if a fa ul t d evelop s in
the con verter it may allow high freque ncy
h a rmonics to be radiated , thus causing radio
interfere nce. T his will be modulated at the
converter switch ing ra te and can a p pear similar to
a n ELB signal.
Note that to date this inte rfere nce has been
associated only with the HF radio . Pilots who
experie nce the phe nome non sh o uld take action ,
con sistent with safe operation s, to rectify it as soon
as practicable, as it could unnecessarily divert SAR
services •
Aviation Safety Digest 115 I 7
�Complete and successful maintenance of aircraft
depends heavily on flight crew. Their advice at
the termination of a flight can be vital to the safe
completion of the next one. Pilots have quite
specific responsibilities in respect of airworthiness
requirements and they have a right to know the
detailed airworthiness status of the aircraft they
are flying. The maintenance release is the means
by which this information is communicated
between the flight crew and the maintenance
organisation.
T h e ma in te nance release is, in e ffect, the
corne rsto n e o f Lhe airworthiness system; however, a
lack. of understand ing by pilots of its use has been
noted during inspections of a ircra ft and associated
records. O ne of the basic m iscon cep Li ons is Lhat the
main tenance re lease is an a irworthiness docu me n t
rath er than an operaLional d ocu ment, a
m isconcep tio n p er petuated by some o p er ators who
do n o t permit pilots to end o rse the main tena n ce
release with de fects. Tb is attitude to th e use of tbe
maintenance release h as p robably stem med from
the fac t tha t the requi rements relating to its issue
an d use are specified in Ai r Naviga tion Orders
Section 100.5.1 , particularly Appendix 5. This A NO
co ntains airworthiness req uirem ents for ge ne r al
aviatio n aircraft and is d istr ibuted to all LAMEs and
maintenance o rganisati on s. IL is o nly made available
to p ilots on req uest; con sequen tly, unless a p ilo t
receives clear instruction d ur ing his tr ai ning o n this
facet of a irmanship he may continue his flying
car eer relying on hearsay in the use of this
important document.
T urni ng now to the actual documen t, the
main te nance release is d ivid ed into th ree parts
which , in combination , provide the pilot wiLh all the
informa tio n h e needs to be ass ured th at a ll
necessary main te na nce h as been carried o ut. It also
provides main tenance person ne l wi Lh deta ils of a ny
work req uired a nd when it h as to be done .
Pa rl One is concerned mainly with ro utine
mainte na nce :
• IL ce rti fies tha t a ll rou tine main te na nce has
been com pleted.
• It specifies tbe period of validity of the
ma intenance release (normall y 100 ho u rs o r 12
mo n ths).
• I t records any inspections o r m ain te nance tasks
req uired d ur ing the p eriod of valid ity of th e
m a inten ance release , such as oil chan ges,
airwor thiness d irectives, time ex pired
comp o nents etc.
Par t Two provides the pilot with a m eans of
reporting d efects and shows him whether
p r evio usly r epor ted defects have been r ectified . A n
o pe n en try in Part Two does not necessaril y mean
that th e aircra h sho uld n ot be flown, buL m ore on
this later . It also provides the p ilot wi th a history of
d efects o n th e aircraft for th e period o r validity of
that m ain tenance r elease. I t is worth str essing at
this point that a pilot is requ ired to en ter d efecls in
the mai n te na nce release.
8 I Aviation Safety Digest 115
Part Three provides a record of the hou rs flown
a nd certifications for Lhe daily inspections carried
o u t. T he record of hou rs flown is necessary to keep
a check o n the cu rrency of the main tenance 1·elease
and to show when mai n te nance called u p in Part
One is d ue. I t is a req uirement that flying hours be
enter ed al least at the e nd of each day's fly ing for
that aircraft. Except when carried out by the p ilotin-comma n d (other than a student pilot) a
certification is requ ired for comp letion of the da ily
inspectio n. ANO I 00.5. 1 specifies the classes of
perso ns who may make the certification.
..
Pilot responsibility
T h e pilot's responsibilities with regard to aircraft
ser viceability and the main tenance release can be
divided in to before a nd after flight requi r ements.
Before fli g h t, th e p ilot sho uld:
• O btain the m ain tenance release' a nd check th at
it is cu rrent, i.e . Lha L the period of va lidity, in
e ith er h ou rs flow n o r elapsed time, has no L
expired. This h e does by ch ecking th e expiry
elate and time in service sh own in Pa r t One and
com paring the latter with the a ircraft
progressive Lota! Lime in service in Part T h ree.
• Exam ine Pa rt T wo for endorseme nts a nd check
that the ce rtification clearing a n y endorsement
is a ppropria tely sig ned and authen ticated with
a licence number. However, as mentioned
earlier, the presence of an open endorsement
does not necessaril y gro und the a ircraft. Air
Navigation Orders, sup pl emented by the
ai rcraft Flig ht Ma nua l, list the aircraft
equip m ent r equirem ents fo r various night
categories an d classes of operation. An
endorsement affecting an y of· Lhose items or
the ai rwonh iness of the aircraft must o bviously
be cleared before the air cra h is llown; but
there are often unserviceabilities which do no t
affect either th e airworthiness of th e aircraft or
the mandatory equ ipment r equ irements. Fo r
exa m ple, an endorsement p laci ng the ADF
unserviceable does not preve nt the use of tha t
aircra ft for VFR fl ight by clay.
• Check for certifica tion of the daily inspectio n in
Part T h ree.
• En su re that the maintena nce release is carried
o n the aircraft.
Afler !light, a p ilot's attentio n to d e tai l in
comp leting the maintenance release is critical, not
o nly to the accuracy o f the e ngineering record ing
system , bu t also to the a irworthiness o f the aircra ft.
His r esponsibilities in Lhis regard h ave been
mentioned earlier but their importance j us tifies
some repeti tion and fui·the r d iscussion. T he two
mai n ar eas of action a re:
• Recordin g flig h t time.
• Endorsing a ircraft defects on the maintenance
release.
An accu rate reco rd or ho urs flo wn is essen tial to
preser ve the integrity of the main tenance system. I t
is a requirement that flying time should be ent~;ed
at least at th e end of each day on which the aircraft
is flo wn. This allows the engineers to monitor
maintenance requirements against time in service,
a nd enables pilots to ensure that those requirements
h ave been satisfied before they accept an aircraft
fo r flight.
. A mor.e exacting responsibility from a day-to-day
airworthiness viewpoint is the requirement to
endorse aircraft defects on the maintenance release.
Failure to exercise this responsibility can result in
corrective maintenance not be ing carried o u t thus
p u tting the next p ilot to fly the ~ircraft at risk. The
ANRs a re quite specific in this regard and there is
no concession o r exception to th is requirement for
a normal main tena nce release, i.e. , when a pilot
considers there is a d efect, or when he becomes
aware of a defect, he must enter on the ·
mai.n tenance r e lease an endorsement signed by him
setting out the par ticulars. Simply telling someone
about th e p roblem or leaving a note on a piece of
pape r are not acce p table alternatives. H owever, this
does not mean that a pilo t shou ld not discuss a
defect with an engineer or perhaps with a more
experienced pilot before making an entry.
Inex p erienced pilots p articularly shou ld be
encouraged to do so. B ut reme mber, if a defect is
not entered there is no guarantee that it will be
picked up during ro u tine maintenance - and there
can be no valid criticism of the maintenance
personnel for failing to d o so.
To summarise, complete and successful
maintenance depends to a large extent on
informa tion entered o n the main tenance release at
the termination of a flight. Pilots ha ve q uite specific
legal and moral responsibil ities in this regard and
should, in their own interest, strive to achieve
thoroughness and accuracy in their use of this
important document.
This extract from an incident report is an
illustration of the foregoing comments:
,
On return from a local flight I complained to a LAME
of .difficulty i? locking the pilot's seat and of a sticky
alumeter. I did not enter these defects in the
maintenance release.
One week later when I again hired the aircraft I
noticed that the seat problem had not been rectified,
but in another position the seat seemed to be secure so
I continued with the flight. Just after lift-off, the seat
lock gave way and the seat moved to the rear causing
me to lose control of the aircraft. It was some time
before I regained sufficient control to climb away and
by then. I w~s several degrees off runway heading.
At this pomt I elected to climb out to 2000 fee t to
regain my composure. I flew in the general area for
about an ho ur before I felt calm enough to attempt a
landing. During this time I again tried to ascertain
whether the seat was secure and it did appear to be so.
I made a normal circuit entry and all appeared to be
well until I was lined up on final. Then, when I leaned
forward to select flap, the seat moved with me and
appeared to engage a slot with a loud 'click'.. Soon
afterwards, when I applied some rudder during the
flare, the seat again gave way and slid to the rear. I
was unable to reach the rudder pedals and again lost
control of the aircraft. It ended up off the side of the
runway on the grass, fortu nately undamaged.
On returning to the operations room I placed the
aircraft unserviceable in the maintenance release for
the seat and several other defects. The LAME came in
and I described the problems to him as well. His only
response was that on no account was a pilot to write
anything on the main tenance release without an
engineer's permission •
l
'Wada.J'a 111ea11 the gizmo's broken, write anythin[J on that bit of paper and -vou'/l be broken too.''
.
Aviation Safety Digest 115 I 9
�Haste and lack of systems
knowledge lead to gear-up landing
ll
When established on downwind at his destination
the pilot o f a PA28R-200 selecte d gear down for
landing. He heard the pump motor operate a nd
felt the aircraft respond to the drag and trim
change as the gear we nt clown , but h e did not get a
down-and-locked indication. With the cause of the
problem not obvious, and being unsure of the gea r
position, he wisely went around from linal for
another approach. When established on down wind
he again tried to extend the gear, but without
apparent success. With last light approaching, he
decided to continue and make what he feared
wou ld be a gear-up landing. I t was!
In the an alysis of this accident, it became clear
tha t it contained some valuable safety lessons.
Unfortunately, the pilot's r ecollection of wha t he
did a nd what actually happened was such that a
detailed factual reconstruction of the occurre nce
was nol possib le. However, to illustrate the
importa nce of having a thoroug h knowled ge of an
aircra ft's systems and of calmly and meth odicall y
following operating h andbook instructions in an
e me rge ncy, a discussion of known events based on
the pilot's recollection of his actions and on the
landing gear system design is offered. It should,
h owever, first be noted that no fault was round in
the la nding gear system after the accident. All the
evidence suggested that it should have worked as
advertised , and that it probably did .
The aircraft is fitted with an hydraulicall y
actuated gea r extension/ retraction syste m powered
by an electricall y driven pump. It is controlled
manuall y by the gear selector switch o r
automaticall y extended by a n airspeed/ power/
a ltitude sensin g circuit. Gear posi tion is rela yed to
the pilot by three green down-a nd-locked lights, a
yellow in-transit light just below the gla re shield
and a red gear- up light, also just below the glare
shie ld , which illuminates if manifold pressure is
reduced to about 14 inches of mercury or less with
the gear not clown and locked . This light a lso
illuminates whe n gear exte n sion ta kes p lace with
the normal selector switch in the up position and
when the gear is se lected up while the aircraft is on
the gro und.
T he automatic extension system lowers the
landing gear regardless of the gear selector switch
position a t speeds between about 75 knots and 90
knots, depending on power setting and altitud e.
Howeve r, the pilot can override this syste m by
p lacing the dual-purpose emergency exte n sion/
override lever in the override position. The landing
gear system then functions as a conven tional system'
conlrolled on ly by the gear selector switch . A yellow
'Auto Ext Off light, immediately below the gear
selector switch, flash es continuously whe n override
is selected.
10 I Aviation Safety Digest 115
During a flight the clay be fore the accident, the
pilot was unable to retract the gear after take-off
until he selected override. In the absence or· any
evident malfun ction of the system the most likel y
explanation is that his ai rspeed at the time was
below the automatic gear extension speed . The gear
retracted normall y after take-off the next day and,
similarl y, functioned norma ll y when extended
before a la nding for ruel , and when re tracted after
the subsequent take-off.
On arrival at h is destination just before sunset,
the pilot joined the circu it and selected gear down.
H e heard and felt all the no rmal indications of gear
extension and saw the in-Lra nsit light illum inate and
then extinguish , but he could not dfscern any
illumination or th e g reen down-and-locked
indicator lights. After checking Lhat the panel light
switch was off (the green lights are d immed when
the panel lights switch is o n) he applied full power
and went around. Climbing away with two stages of
flap selected to keep the speed clown he selected
gear-up, but did not perceive any indication or gear
movement. He then 'cycled the gear switch' durin g
the climb and aga in on downwind with no further
indication. T he actual selections he made could not
be determined - but when the a ircra ft la nded the
gear was up, the override lever was in the override
position and the gea r selector was up.
Concerned about the fading daylig ht, the pilot
had not taken tim e to ca lmly and rationally go
through either the normal or emergency extension
procedure laid clown in the o perating hand book.
No doubt he was confused about the absence of
lights on the lirst attempt, but from his d escription
or events and ground witness evid ence, the gea r
was almost certainl y clown th e n. However, the
investigation did not conclusively dete rmine wh y
the lights did not illumina te. One possibi lity is that
the y were illuminated but dimmed. The pilot may
have only checked that the panel ligh t rheosta t was
ro lled off without actually e nsuring the on/off
switch was throu gh the sp ring load ed detent and in
the off position .
The absence of a gear down indication and the
approaching d arkness undoubted ly p laced this pilot
under stress and led him to make a hasty decision
to land wi thout thoroug hl y examining his situation.
He decided when on downw ind the second time
that he would not have sufficie nt time to go arou nd
from that approach and still la nd in daylig ht. At
that time, however, last lig ht was still a bout 13
minutes away. Iro nicall y, had he approached the
situation more methodicall y and got the gear clown
again , he may well have seen the g reen lig h ts on his
second attempt: the sun had by then gone down ,
and the indicators, even if they we re dimmed, may
then have been visible.
..
23
1.
2.
3.
4.
5.
6.
7.
8.
9.
10 .
11.
12.
1 3.
14.
15 .
14
15
26
17 18 19 JD 31
STA LL WARN ING INDICATOR
ADF INDICA TOR
C LOC K
TURN INDICATOR
AIRSPEED INDICATOR
DIRECTIONAL GYRO
ATTITUDE GYRO
GEAR "UP" WARN ING LI GHT
GEAR "IN TRANSIT" LIGHT
VERTICA L SPEED INDICATOR
AL TI METER
AUDIO SELECTOR
COMPASS
OMNI & GUDE S LOPE IN DICATOR
AIR CO ND. INDICATOR LIGHT
33 34 JS
32
16.
17.
18 .
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
36
])
38 3940
TRANSCEIVERS
TRANSPOND E R
AOF
DME
SUCTION GAUGE
C IGAR LIGHTER
HEATER / DEFROSTER CONTROLS
MIKE JAS::K
PHONE JACK
AUTOPILOT
ENGINE INSTR UMENT CLUSTER
OMNI-COUPLER
NAV SELECTOR
PITCH CONTROL
MAGNETO& S TARTER SWITCH
In his haste the pilot also forgot to ava il himself
of other assistance that was available in the aircraft;
one of his passengers was a private pilot with
ex pe rie nce on this aircraft type. Howeve r, the
passenge r was unawa1·e of the situation until
touchdown. The pilot had not com me n ted on his
problems beca use he did not want lo alarm his
passenge rs.
Functional tests made on the la nding gear during
the investigation failed to re veal an y sig nificant
abnormality a nd the system operated norm~lly in a ll
modes. The only discrepancy found was in the
adjustment of the gear-up indicator micro switch ;
the throttle had to be full y close d to operate the red
gear warning light a nd the gear warning horn.
When the operation of the syste m and the
indicator light dimming circuit was d emonstrated to
41
41
43
31.
32.
33 .
34 .
35.
36 .
37.
38.
39.
40 .
41.
42.
FUEL GAUGES
MANIFOLD PRESSURE GAUGE
TAC HOMETER
GEAR SELECTOR
GEAR OVERRRIDE L IGHT
GEAR POSITION LIGHTS
MICROPHONE
FRICT ION LOCK
THROTTLE QUADRANT
ALTERNATE AIR CONTROL
EGT GAUGE
INSTRUMENT PANEL LIGHTS
H. CIRCUIT BREAKER PANEL
44. CIRCU IT BREAKER COVER
the pilot a l the completion o r the tests, he agreed
that in all probability the gear had been down a nd
the lig hts dimmed on that first a pproach.
The scen e was set l"or this accident whe n the pilot
had difficulty getting the gear up after take-off the
previous day. Unable to a na lyse the occurrence
because of inadequate know ledge of the landing
gear system , he was left with some doubts abo ut its
serviceability. Then, when faced with an apparently
abnormal indication the next d ay he was probably
me ntall y tuned lo accepting that a gear system
malfunction actuall y existed. However, at that stage
the accid ent was not inevitable: it only became so
whe n the pi lot, in. a stressful situa tion, was impelled
to ~et in haste witho ut full y considering his
options •
Aviation Safety Digest 115 I 11
�An account of an incident between a Cessna 172 and a Fokker Friendship at an· uncontrolled
aerodrome.
/
I
l
It was approaching 1700 hours on a Sunday
afternoon, and I was about to fly to a town 68 nm
from my base. Because I had done this flight
numerous times and had 1300 hours flying
experience in this area I planned to conduct the
flight NOSAR NO DETAILS.
When I arrived at the airport a large storm was
building up to the south west and west, but the
weather was perfectly clear to the east, the direction
I was to travel. The wind was 30 knots from the
south west, straight down Runway 06-24, the cross
strip. I untied the plane after carrying out the preflight inspection and commenced taxying, realising
that I had only a few minutes to be airborne before
the approaching storm would close in , possibly for
some time. I also realised that it was the time the
Sunday afternoon Fokker normally came in, but
there was no sign of the agent at the airport so I
assumed that it had either been and gone or was
running late, which meant I might meet it at m y
destination.
I had always got on well with the Fokker pilots,
and found it easy to maintain separation, normally
offering to keep clear for their benefit, even in
situations where I had priority.
I called on VHF and advised 'any traffic' that I
was taxying for Runway 24 for my destination.
There was no reply.
I did my normal lookouts, and as I was about to
enter Runway 30 to back-track I saw the Fokker on
the downwind leg for Runway 12 at circuit height.
I presumed it would only confuse him if I called
again, since I knew my departure on 24 with
subsequent left turn would have me well out of his
way for his landing or overshoot on 12, or his
circling prior to landing on any other runway. The
Fokkers very rarely used 06-24.
As I commenced my take-off run on 24 I saw that
he was on final for 12. Because of the proximity of
the storm by this time, I turned left onto the
crosswind leg of my departing circuit at a height of
about 300 feet, about half way down the runway.
I looked behind at this point to see if the Fokker
had landed, and t6 my horror saw him a half mile
behind me at my height (about 500 feet AGL), and
heading the same direction.
I immediately altered my heading 20 degrees to
the right, assuming he would turn left rather than
right, and descended to 400 feet AGL until
subsequently I saw the Fokker about normal circuit
height, a couple of miles away, and still in the
circuit area. I then climbed to 3000 feet and
continued to my destination. Again, I h ad not called
the Fokker whilst the above eventuated. My main
con cern was to maintain separation myself and not
to confuse him , but I did wonder if he h ad sighted
me at any stage.
12 I Aviation Safety Digest 115
Ten minutes later I heard Flight Service (58 nm
from the departure aerodrome) call the Fokker to
see if he was in VHF range. He replied that he had
been circling for 10 minutes due to crosswinds in
excess of his maximum.
I heard no further radio communications at all
from the Fokker until his VHF taxying call on
departure.
I spoke the next day with the airline agent, who
had arrived at the airport as I was taking off. He
said the Fokker abandoned his approach on 12 and
that he was convinced the Fokker was going to leave
wheel marks on the roof of my Cessna. He asked the
Captain when he finally landed had he seen the
lighty that took off. He hadn't.
I was upset at having such a close shave, and gave
the whole incident much soul searching. In
retrospect I should have tried to establish contact
with the Fokker when I first sighted him, but in
view of the approaching storm, my concern to get
airborne, and his obvious concern to land, I felt it
wisest not to confuse the situation. Also, since he
had not answered my earlier call I felt there was a
chance he may not answer again. Further-more, the
cross-wind at that point of taxying was so strong that
I needed both hands for operating the ailerons and
throttle for control of my aircraft.
I did not put a 225 in. I felt that perhaps I
should have, but I did not wish to harm a Captain's
career. Also, Fokker Captains, as indeed all RPT
pilots, have always been most helpful with relaying
radio messages. Indeed, I have found them to be
more 'brother pilots' than some GA pilots are.
I had no wish to 'dob' one in, and have pleasant
memories of hours spent in Fokker jumpseats. I
deemed an article in Aviation Safety Digest would
do far more good, assisting all Fokker Captains to
play their part in maintaining separation from light
aircraft, and assisting us bush pilots to do our bit in
keeping clear of the big ones.
Comment
This account of a close encounter tells its own story,
but three points are worthy of comment.
First, the pilot's decision not to submit a 225. This
precluded an investigation of the incident, thereby
denying the opportunity to learn why the broadcast
system failed to work.
Contrary to the pilot's suggestion, the air safety
incident reporting system is not a vehicle for
'<lobbing other pilots in' . The objective of air safety
investigation is to promote aviation safety through
the identification of unsafe conditions and
procedures: it is not to apportion blame or liability.
\
- --
With that commen t made, we express our
appreciation to the pilot for submitting this report of
his experience for publication in the Digest. Firsthand accounts of incidents and experiences such as
this one are always superior to any admonitions
made with the benefit of hindsight from the
comfortable seclusion of an office.
The second point concerns the actions of the F27
pilot during the p eriod he was holding . It is
probably fair to say that most amateur pilots look to
the professionals for guidance, if only through
example. Consequently, to circle for ten minutes
and then land without making one broadcast of
intentions is h ardly a good example for an RPT
pilot to set .
Our contributor commented in his covering letter
that he hoped this article would get the message to
the RPT pilots that they should not be afraid to use
their radios and talk to the 'bushwackies'.
The third relates to our contributor's concern that
to call the F27 pilot during the encounter would
have confused the situation. As he said in retrospect,
he should h ave tried to establish contact when he
first sighted the F27 .
Attempts at establishing communications are
unlikely to cause confusion, whereas reliance on
assumptions will almost certainly do so, or worse,
result in the development of a situation in which a
pilot takes inappropriate action or is forced to
modify his operations at a critical stage because he
does not know the other· pilot's intentions.
And a final though t - RPT pilots , without a
doubt, appreciate the gestures shown by the m any
GA pilots who give way in consideration of tight
operating schedules. But when you are extending
that courtesy, do tell the other pilot what you are
doing. W ithout communication the gesture may be
interpreted as indecision •
Aviation Safety Digest 115 I 13
�Engine fire during start
A chain of circumstances
The pilot's report stated: On request.from lhe owner, I
was posi.tioning the aircniftfor refuelling. It was vel)'
difficu lt to start - the outside air tem/Jerature was minus
one degree Celsius and the bal/e1y was sluggish. After
numerous allemjJfs to sta rt the aircraft I considered that I
may have overprim.ed the engine. I shut dow11 the
electrical system, selected full throttle and lea11 mixture,
and wailed for a couple ef minutes before attemjJ/ing a
'hot' start. The engine backfired, ran for a couj1le ~f
seconds then stopped. I tried one more start b~(ore noticing
smoke romingfrom the front of the aircraft. I immediately
shut down lhe electrical and fuel systems, gmbbed a fire
extinguisher and, with the aid of a mechanic from a
nearby maintenance facilit)', extinguished the fire. The
aerodrome Jiu service attended. Damage was restrirted to
minor burning of the fibreglass a round the exlw usl ~)•Stem
outlet.
Subsequent investigation of this incident included
d iscussion between the inves tigato r, the owner a nd
the pilot, and referen ce to th e Pilot's Operating
Handboo k for the aircraft type and th e Ope ra tor's
Manual for the engine.
Describing his technique of starting the e ngine,
the pilot said that he m ade two or three strokes of
the manual prime r before attempting the sta rt but
the engine d id not fire. H e then pumped the
th rottle a couple or times and tried starting aga in,
withou t success. H e tried again a nd then stopped to
let the engine 'settle'. Afte r several more p umps of
the throttle h e tried to start the engine a nd it
backfired. He tried yet again and d uring this
attempt noted what h e thought was steam coming
fro m the en gine cowl. H e initially believed it was
steam because he had washed the ai rcra ft d own to
remove the frost.
As the cloud of white va pour continued to rise he
realised it was serious, shut down the systems a nd
exited from the cabin with th e fire exti nguisher.
The pilot late r emph asised tha t wh en he used th e
throttle for priming h e d id not use full strokes but
on ly abou t three-quarters of the full thro ttle
movement. He added that, during his training at
the local aero club, he h ad bee n taught to use the
throttle rathe r tha n the normal p rime r. He be lie ved
this teaching was prevalent amongst instructors.
Re fe re nce to the appropriate manuals would ha ve
provid ed the pilot with the correct procedures to
follow. In th is case. th e aircra ft was a Pipe r PA-2818 1, fitted with an Avco Lycoming 0-360 e n gine.
The No rmal Procedures section of the Pilot's
Operating Handbook provid es the following
ex pa nded checklist for e ngin e sta rting:
After landing I taxied tlu• Shrike Co111111a11der into the
dispersal area wilh the landing lights on and 1wliced the
r~(ueller standing by the ji1el outlet with the 1111it opened
allll lhe reji1elli11g hose out. The visibility at the time was
/wor due to rain and also, as was later determinNI, the
ovfl'head flood lights were unservirealh. The afrcr(ifi was
j1ositio1ml along.1irlP the unil with the right-hand sirfr
11Mres/ to it, as the/iiel inlr'I is on this sirlP. I switched off
the landing lights a/Jjnoaching thP u11it lo avoid dazzling
the refueller.
Aft1' r shutting down both engines, and before we had
alighted ji'fJln the aircraft, the refueller had set up his
ladder and was extending the hose for refuelling. As he
obviously needed no assistance, I dise111harl1erl my
J}{/ssengn:~ a11d helped them wilh their baggage lo the
terminal and oul of the rain. On m tr,ring the terminal, I
11otirwl that 111y returning j){lssengn.1· also had a large
quantity of baggage; therefore T assisted them to rril'I)' and
load it 011/0 thP ainraft. By this lime the refuelling had
been romjJlf'fed and I checl1ed thPfuPl level i11 th e lank to
be Slll'f' it was actually full.
It was mining at the li111e and, having chedml the ji1el
level, l did afuel drain and retum nl to the terminal
where I signed the Juel dorhl't and checked the quantity
/a/m 1. This amount was what I ex/Jected. I thm loaded the
passenge1:~ and eventual!)' commenred a take-off
During the lake-ojj; I deter/er/ a slight, variable,
asy111111etrir sourul ji·o111 the engines and although lhf'
grwg1'.\' ap/Jeared normal I abandoned the talw-1?f(fro111
abo11/ 75 knots. I ran the engines ujJ to 1800 RPM lo
eh eel! their pe1fon11a 11ce. The gauges and so1111d were
normal. Susj1erti11g that a small a11101111/ of water could
have jJo.uibly caused the engines lo act as they did I lined
11/J for another take-of(, this time a/JjJlyingfull power
whilst holding on the brakes and rlosely 111011itori11g the
engine Jmfor111a11.ce. They did 11ol give ji1ll power so T
tn111i11ated the.flight. While taxying back lo dispersal it
orrurrnl to 111e that, when chec/1ing thefuel lanl! contents,
tlteji1el smell was turbi11e j11el and 110/ avgas but, at the
ti1111', this had not rrxist.ered. A subsequent chec/1 tf the
.fuel dorl!et co1!fin11I'(/ the error.
STARTING ENGINE
(a) Starting engine when cold
Open the throttle lever approximately ~ inch. Turn
'ON' the master switch and the electric fuel pump.
Move the mixture control to full 'RICH' and engage
the starter by rotating the magneto switch clockwise
and pressing in. When the engine fires, release the
magneto switch, and move the throttle to the desired
setting.
If the engine does not fire within five to ten
14 I Aviation Safety Digest 115
set·onds, disengage 1he starter, prime 1he c11i.,ri11e and
repeat the starting procedure.
(b) Starting engine when hot
Open the throttle approximately Y2 inch. Turn 'O N'
the master switch and the electric fuel pump. Move
the mixlllre control le\'er to full 'RICI I' and engage
the starter hy rotating the magneto switch clockwise
and pressing in. When the engine fires. release the
magneto switch and 1110\'e the throttle to the desired
setting.
(c) Starting engine when flooded
The throttle le\'el should be full 'OPEN'. Turn 'ON'
the master switch and turn 'OFF' the electric fuel
pump. Mo\'e the mix1ure control le\'cl to idle cut-off
and enga ge the s1arcer by rotating the magnelo switch
clockwise and pressing in. When the engine fires,
release the magneto switch, a<ham:e the mix1ure and
retard the throttle.
If the Pilot's Operating H a ndbook does not
contain the full details, e.g. priming,. then refer to
the engi ne manufactu re r's Operating Manual wh ich
in this case states:
STARTING PROCEDURES
The following starting procedures arc recommended:
howe\'er, the starting characteristics of \'arious
installations will necessitate some variation from these
procedures.
.\'ote: Cra11ki11g period.1 11111.1/ bi• limitrd In /1•11 ( /(}) lo IH •1•h •1•
(12) serouds n•ith afi<•t' (5) 111i1111lr rr.1·/ b1•tw1•1•11 rm11/1i11g
/1t riods.
a) Carburetted engines (cold).
(1) Perform pre-flight inspection.
(2) Set carbure11or heat control in 'OFF' position.
(3) Set propeller governor control in ' FULL RPl\I'
position (where applicable).
(4) Turn fuel \alvcs 'ON'.
(5) Move mixture control Lo ' Fl' l.L RICH'.
(6) Turn boost pump 'ON' (where applicable).
t7) Open throttle approximately 14 tra\'el.
(8) Prime with I to 3 strokes of manual priming
pump or activate electric prime r for I or 2
seconds.
(9) Set magneto selector switch (Consult airframe
manufacturer's handbook for correct position).
(I 0) Engage starter.
( 11) When engine fires move the magneto switch to
'BOTH'.
( 12) Check oil pressure gauge. If minimum oil
pressure is not indicated within thirty seconds,
stop engine and determine trouble.
Note: If e11gi11rfail.1 to ad1i1•111• a 1111rm11/ .1 /11rt. a .1.1111111• it
to be Jloodrd and me .1/mulard dl'<tri11g /1ro<t'd11rr, t/11•11
n·prat above step.1.
b) Carburettor engine (hot) - Proceed as outlined
above omitting the priming step.
T he reader will now rea lise th at as well as risking
a serious fire by u sin g incorrect priming techniques
the pilot could have caused a failure of the starte r
motor by exceeding the recomme nded cranking
periods. Complia nce with this req ui re men t wo uld
have allowed time for the excess fue l collected from
over-priming to have cleared from tl1e e ngine.
(cont'd on page 15)
In additio n to a ll the othe r factors included in his
report the pilot stated that there was a forecast fo r
possible fog a t h is d estination from a bout the time
he was ex pecting to arrive the re.
A contributing factor not included in the pilot's
report was that the rerue ller on du ty was a re lie f
operator who was un fa milia r with this type or
a ircraft and d id not see the fue l pl aca rd on th e
wing.
*
Engine fire during start
~Ue L
I OO' 130 OCT
28.31 US.GAL.CAP
M IN
\
\
T his incident is a classic example or how a
num ber of factors may come togeth e r during the
d evelopment o r an inci<le nt or accide nt. To quote
but a few o f the factors wh ich arose during this
incid e nt:
• It was' n ight ti me, raining, a nd the flood lights
were u nser viceable ...
• T he pilot assumed the refueller knew wha t he
was doin g because o f a n appearance o f
efficiency ...
• The refue ller did no t check the pilo t's
requireme nts even tho ug h unfamilia r with th e
aircra f't ...
• The pilot beca me heavily in volved in nonopcrationa l matters, a common situation in this
type of operatio n ...
• Etcetera . ..
The pilot is to be com me nded on e lecting to
aba ndon the take-off whe n he detected a problem
with the en gines a nd in te rminating the flight whe n
the su bsequen t grou nd run proved unsatisfactory.
I [' he had not done so the fin a l o utcome may well
have been tragic.
We can be sure that th is pilot now h as a good
appreciatio n of the subtle way in which
circumstances can combine to produce a seriou s
problem - perhaps a maj or accident. It is hoped
tha t every one of our reade rs will also be helped in
the recognition o f similar facto rs wh en they appear
on the scene from ti me to tim e •
*
*
(ront'rLJ
The ru les are simple - if yo u wa nt to learn th e
correct way to operate your aircraft and its
equipme nt re fer to the a ppropriate man uals
produced by th e ma nu facture rs; if comp lia nce with
their recomme ndations does not work, the n it is
time to sec your mainte nance organisation •
Aviation Safety Digest 115 I 15
�Cockpit etiquette
by Arnold Reiner (courtesy Fligh t Crew)
This is not about co-pilot deference to the captain or captain's condescension to the co-pilot. This is
about survival through respect.
A BAC 1-11 with 73 passengers on board landed
lon g a nd sped off the rollout end of the runway at
flying speed! Whe n the dust settled , one passenger
was seriously injured a nd th e aircraft was
substantially damaged. T he captain never
considered a go-around . In contrast, according to
the Nation al Tran sportation Safety Board report,
the co-pilot considered a go-around many times and
tried to warn the captain in subtle ways su ch as
mentioning the possibility of a strong tailwind and
the slown ess of the flap exten sion. The first
officer's remarks did not make a den t in the
captain's resolve to land the aircraft r egardless of
speed and remaining ru n way length . The co-pilot
migh t just as well have not been there.
Following take-off and climb to abou t 1500 feet, a
B747 ba nked stee ply and dived into the sea at an
airspeed in excess of 300 kno ts. In vestigating
au thorities determined that the cap tain's attitude
director ind icator h ad malfunctioned in a way
which did no t display a warning flag. T h e cap tain
followed the gyration s of th e failed indicator an d
flew into the sea while the first officer attem p ted in
a m arginally cohe rent way to draw the cap tain's
atten tion to the two good ho rizon displays in th e
cockp it. T he co-pilot was cited for his lack of
assertiveness while th e captain was fa ulted for
relying excessively on one cockpit instru ment.
A B727 crashed on land ing d u rin g a low visibility
app roach . O ne person d ied a nd 32 were injured
wh en the plane landed long and fast and the
cap tain a ttemp ted a go-aro und after being
committed to a full stop land ing. T he NTSB report
cited the co-pilot for not being ou tspoken enou gh
wh en the flight was cond u cted in a careless or
dan gerous m anner. T he report continued , 'Pilotsin-com mand should foster an atmosphere in th e
cockpit which permits constructive advice a nd
positive recommendations for ch ange wh ere safety
is involved'.
T he reality is tha t captains, even well meaning
ones, do not always foster 'an a tmosph ere of
constructive advice an d positive recomme ndations'.
Su ch behaviou r someti mes en courages co-p ilots to
take great p leasure in watching captains err - a t
the risk of all on board. Recently, a B707 first
officer rela ted a story abou t a captain wh o tried to
tu rn off too soon after lan ding on a slippery
runway. To hear the first officer tell it, the cap tain's
ego was as big as the aircraft. When it became
apparen t to the first officer tha t the captain was
attemp tin g to negotiate the rapidly approachi ng
taxiway at a n excessive speed, h e said to the
captain , 'You're not goin g to make it'. T h e
statemen t was repeated several times - each time
strength ening the captain's resolve to accomplish
16 I Aviation Safety Digest 115
the feat. T he co-pilot was right. As the aircraft slid
in to the wa tersoaked grass between the ru nway and
taxiway, the fi rst officer's final ban te r was, 'You
d idn't make it'. The co-pilot related the story with
triumph, u naware that h e played a han d in th e
incident.
Wha t's th e answer? How does a captain accept
the honest concerns of a young co-pilot - or an old
co-pilot? And what will foster a sp irit of teamwork
and co-operation in the co-pilot? T he answer is
respect. Respect for the o ther's knowledge and
concerns. Co-pilots do not have to be h igh time
veterans to know when the captain misreads th e
descent minima, h ears a clearance incorrectly or
fixates on the ru nway while sink rate doubles or
airspeed d eviates excessively from normal. As a
rule, co-pilots d on't like to be constantly told how to
fly and ca ptains don't like to be 'advised' too
freq uently wh en their tech nique deviates from the
norm. After a wh ile even the most obtuse pilots
develop a certain tolerance for the non-standard
and know to hold their tongues lest the working
environ ment becomes intolerable . With th is in
mind, wh en a warning or cau tionary remark is
made by either crewmember, each owes it to the
oth er to consider its worst implications . Words must
be chosen carefully or they may be misinterpre ted.
O n the other h and, subtle hints no t directed at the
root of concern may be misund erstood and
ignored. T he BAC 1-11 co-pilot's hints about
excessive speed for the flap setting and high
tailwind made no imp ression on the captain as h e
bore in toward the runway a t a n impossible landing
speed. Comments must be made in a positive
manner and shou ld relate directly to the concern ,
possibly containing d irection, e .g. 'Go around, we
are too fast'.
Even though progressive companies require their
crews to call ou t significant deviations from normal
fligh t profiles and speeds, helpful, p recisely worded
statements d efining danger are what the p ilot doing
the fl ying needs. Tactfully beating around the bush
at critical periods in the flight, as we h ave seen, is
not an effective ap proach to a life and death
situ ation. On the other ha nd, captains and co-pilots
must accept a warning for what it is and be
prepared to act upon it •
Observe your authorisation limits
Have you ever been tempted to go below your
authorised minimum height during a practice
forced landing? The pilot involved in this accident
did.
The two occupants of the aircraft were trainee
commercial pilots, each with about 135 hours flying
experience. The pilot in command had been
authorised to conduct practice instrument
approaches to a nearby NOB and, with the exercise
completed, was returning to base when his
companion suggested that they make a practice
forced landing. T he pilot agreed and the throttle
was closed . He then carried out the appropriate
checks and set up an approach to a paddock in the
training area. W hen established on final he
recognised th at he was undershooting and decided to
continue with the approach to see whether he would
have reached the paddock. At a height of about 40
feet and about 100 metres short of the paddock he
realised that he was _very close to the ground and
ra pid ly opened the throttle
the engine did not
respond . A second attempt achieved the d'esired
result but by then the aircraft had hit power lines,
which the pilot had not seen. Trailing three lengths
of cable, the aircraft stayed airborne but would not
climb. The pilot commenced a left turn to avoid
trees and silos, but after turning through 180
degrees the aircraft touched down. Realizing that
further flight was impossible the pilot closed the
throttle and managed to stop the aircraft without
incurring any additional damage.
Both pilots were aware that they were not
authorised to go below 500 feet AGL. The pilot in
command pressed on out of curiosity. His
companion went along without comment and said
later that , although he was concerned, he was also
curious as to whether they would have reached the
paddock.
These two were lucky. Others have not been so.
Authorisation limits are imposed for good reasons,
and the charred and bent ruins of many an aircraft
attest to the dangers of violating them•
The power fines struck by the aircraft, replaced by the time the photograph was taken. Direction of approach is arrowed and the
aircraft is circled at left of the photograph.
J ust before rotation, d u rin g ta ke-off at Hobart
Airport, th e nosewheel of the B737 struck a hare
which was hopping across th e runway. Fortunately
the air craft was not damaged.
T he pilot filed a 'mid-hare collision ' report •
The aircraft as it came to rest. Broken power lines are shown wrapped around the left undercarriage, rear fuselage and right stabilator
Aviation Safety Digest 115 I 17
�Survey of accidents to Australian
civil aircraft 1980
General Aviation operations 1976-1980
Accidents
Total
Fatal
Aircraft damage
Destroyed
Substantial
Minor/none
Fire after impact
Fatal accidents
Non-fatal accidents
Fatalities
Crew
Passengers
Others
Injuries
In aircraft
Fatal
Serious
Minor/ none
On ground
Fatal
Serious
Minor
Hours flown (thousands)
Accident rates
(per 100 OOO hours flown)
Total
Fatal
Number of aircraft on
Register at 30 June
1976
1977
1978
1979
1980
243
19
221
19
249
26
243
19
253
23
32
214
0
27
191
4
49
199
2
38
203
3
32
220
3
7
5
4
2
10
6
6
6
3
7
21
32
0
18
20
5
26
25
6
19
13
1
20
36
0
53
13
543
38
13
456
51
31
540
32
22
440
56
27
495
0
1
0
1 348.0
5
5
3
1 529.0
6
0
1
1 539.7
1
1
0
1 698.9
0
0
0
1 795.4
18.03
1.41
14.45
1.24
16.17
1.69
14.30
1.12
Australian legislatio n imposes a mandatory
require ment fo r the repo r ting or a ll accidents a nd
incidents in volving Austra lia n civil aircraft. T hese
occu rre nces a1·e subseque n tly inves tigated by the
Bureau or Air Safe ty In vestigation fo r the p urpose
of p reventi ng fur the r acciden ts a nd incide nts.
Re ports a re a na lysed to enable facto rs tO be
assig ned in respect of each occurre nce. Re levant
data on the man , th e machine a nd the
e nvironme n t, together wi th the assig ned facto rs, are
the n recorded in a compute r-based system a nd used
in the accide nt p re ve ntio n program.
T he Bureau a nnuall y prod uces a publication
d ealin g with statistica l analysis of the reco rded
in fo rmation on repo rted accid ents. T he Survey <if
//cridents to Australian Civil Aircraji 1980 was re leased
early th is year and is availa ble from Au stralia n
Gove rnme n t Publishing Ser vice Bookshops. I t
contains a large amount of statistical detail in
respect of the 1980 accident 1·ecord , including types
of accirlen t, pilot ex p erience, assig ned factors a nd
so o n, lor airline, gen era l aviatio n a nd gliding
ope rations.
The Survey also contains a section devoted to a
review of accident ra tes and acti vity d ata over past
years fo r a ll categories of airli ne a nd general
aviation fl ying, th u s giving a n ind icatio n o f th e
cha nges which have occu rred in fl ying acti vity and
accid en t ra tes ove r th e pas t te n years.
O ur reade rs may be interested to see the gra p hs
a nd tables prese n te d here, wh ich have been
ex tracted from the 1980 S11 rvey. Th e gra phs in
14.09
1.28
4 280
4 726
5 250
5 847
6 141
1976
1977
1978
1979
1980
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
par ticular give a p ictu re of the overall tre nds in
genera l aviation. Five-year periods a re used for
trend assessme nt because there can be su bstantjal
ra nd o m fl uctuations in accide nt nu mbe rs from year
to year, as may be seen fro m th e tables.
General aviation acti vity contin ues to inerease a t a
rate of about six pe r cent pe r year a nd the tota l
accident ra ce is d ecreasi ng a t about fi ve per cent
per yea r . Provisio na l fig u res fo r 198 1 ind icate that
Lhe total accide nt ra te tre nd is be ing maintained.
O bviously some o r the e ffo rt tha t is directed to
imp ro ving avia tio n safety in Austra lia is e ffective.
The data re fers on ly to a ircra ft accid ents, the
d e finition of an accide nt be ing:
An occu n-ence associated wi1h the operat ion of an a i1·craft
which takes p lace between the time an)' pe1·son boards th e
aircra ft with the in ten tion of fligh t unti l such time as all
persons have disembarked , in wh ich
(a)
a person is fata lly or seriously inj u red as a result of :
being in the aircraft, or
d irect contact with any pan o f the aircraft, including
parts which have become detached from the aircraft,
or
d irect exposure to jet blast.
except when the injuries are from natural ca uses, sel fin fl icted or innicted by other persons, o r whe n the inj u1ies
are LO stowaways hidi ng outside the a reas n orm all y available
to the passengers and crew; or
(b)
the air cra ft incurs su bstantial damage o r is destroyed; 01·
(c)
th e ai rcraft is missing or is comple tely inaccessible.
No te: An aircra ft is considered to be missing when the
offi cial search has heen 1ermi nar.ed and the wreckage has not
been located •
Five year averages of general aviation accident rates
4 0 .0
r - --
----.--- - --.---"""T""-----.
.........
Airline operations 1976-1980
Accidents
Involving fatalities
Involving serious injury
Involving minor/no injury
Total
Aircraft damage
Destroyed
Substantial
Minor/none
Fire after Impact
Fatal accidents
Non-fatal accidents
Fatalities
Crew
Passengers
Other
Total
Injuries
Fatal
Serious
Minor/ none
Hours flown (thousands)
Accident rates
(per 100 OOO hours flown)
Total
Fatal
Number of aircraft on
Register at 30 June
18 I Aviation Safety Digest 115
30.0
~
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
·o
0
0
0
357.0
0
0
381
360.8
0
0
0
36 8.2
0
0
0
365.7
0
0
0
377.4
0
0
0
0
0
0
136
132
131
0
0
153
0.29
0
145
c
0
~
7 .0
:J
0
.r::
'(/)
6.0
Q)
.r::
2 0 .0
Fixed
u
c
:J
~
50
Iota/
0
0
0
ace ·
'dent
engine.
0
0
0
0
0
2 .0
rate
.
Wtng .
s1ngte .
Glid ing
(i;
IJer 70
a.
oooh
Q)
§
Ours
c
Fixed wi ng m ulti -en gin e.
Q)
-0
u
u
~
10 .0
9 .0
10
1971 - 75
72- 76
73- 77
7 4- 78
75- 79
76- 80
8 .0
1971 - 75
72-7 6
73- 77
74-78
75- 79
76- 80
Aviation Safety Digest 115 I 19
�Mast bumping in helicopters
T
w
w
(a) neutral cyclic
(b) lateral cyclic causes rolling moment
w
(c) trimmed roll attitude and lateral motion
FIG.1
T
Ttr
w
w
(a) symmetric 1G flight
(b) symmetric zero G flight
FIG. 2
This article was adapted from one o riginally
publish ed in the U.S. Navy safety magazine
Approach. Mast bumping occurs when the
he licopter's main rotor hub contacts a nd d eforms
the rotor mast. The next stage is separation of the
main rotor mast with catastrophic results. Peculiar
to semi-rigid (teete rin g) rotor systems as fitted to
Bell 47, 205, 206, 2 12, 214 and Hiller 12E, for
example, inflight mast bumping has been the cause
of more than 50 fatal accidents in the US Armed
Forces a nd two in the RAAF. Fortuna.re ly, we have
not experie n ced a!1 accident in Australian civil
aviation in which mast bumping has been ide ntified
as a contributory factor, but this record should not
become the ca use of complacency. Mast bumping
can be pilot-induced by the use of poor fl ying
techniques a nd the re a re about 170 he licopters in
Au stra li a embracin g the types me ntioned above.
The problem of mast bumping occurs when the
rotor head tilts and contacts the mast; in other
words - whe n the ro tor flaps excessive ly. Ge nerall y
spea king, flapping amplitudes reach o nl y a ve ry
small percentage o r the maximum allowed for
manoe uvres within the flight envelope. As an
example, provided that retreating blade sta ll is
avoided , hig h forward flight speed s at high gross
20 I Aviation Safety Digest 115
weights and density a ltitudes result in fla pping
angles or approximately 15 per cent or less of th e
maximum allowable for a typica l semi-rigid system.
Assuming centre of" g ra vity limi ta tions (forward
centre of gravity limits in particular) are not
exceeded , gusty conditions can increase rotor
flapping by a simil ar a mo unt. Sudde n changes in
a ttitude, as induced by abrupt cyclic input or by
mechanical fail ure, e.g. loss or the tail ro to r or
e ng ine power loss, can a lso increase !lapping values
to as much as 60 to 70 per cent of th e limit, a nd
sideways flight to the right a t maximum permissible
speed will increase flapp ing similarly. The reason
for the last item is th a t the directio n of rotation of
th e main rotor on these h e lico pters is clockwise
whe n looking up throu gh the rotor. The most
critical manoeuvre in regard to mast bumping,
howeve r, is one that ge nerates low g, such as the
pushover at the top of a zoom climb. To
understand wh y, think back on yo ur knowledge of
helicopter control. If the pilot desires a change in
pitch or roll attitude, the primary control is cyclic,
which a llows tilting of the rotor thrust vector with
respect to the mast. As a res ult, a n unbalanced
mome nt is gen erated a bout the aircraft centre of
gravity and fu selage attitude is ch anged (see Fig. I).
A more d eta iled look al forces acting on a
he lico pte r in symmetric, one g a nd zero g fli gh t is
shown in Fig. 2 .
Note that in Fig. 2(a) the rotor thrust is tilted
slightly le ft so that the horizontal component of
main rotor thrust will ba lance the tail rotor thrust
a nd provide for lateral equilibrium . In Fig. 2(b) the
pilot has induced a condition o f near-zero thrust by
reducing collecti ve in conjunction with relatively
rapid forwa rd cyclic a pplicatio n. Consequently, with
no force to balance tail rotor thrust, the result is le ft
yaw, ri g ht side slip and, most impo rta ntl y, rig ht roll
- even though latei-al cyclic remains neu tral.
As the roll accelerates, the tip path lags the
fuselage rolling motion slightly, d epe nding on the
roll rate and other desig n cha racteristics o f the
rotor. This results in a condition i11 which the
d e;ua 11ce between rotor head and sha ft is reduced
(see Fig. 3).
This clea ra nce reduction is minor, howeve r, and
will not in itself lead to mast bumping. But recall
that the aircraft is continuing to roll to the right,
d es pite ne utra l lateral stick. Instinctively the pilot
would counte r with left cyclic in order to stop the
right roll. Response to the left lateral con trol wi ll
FIG. 3
cause upward flap ping o n the adva ncing (right
ha nd) side of the rotor disc, the reby further
decreasing the clearance between the rotor h ead
and the mast on the re treating (le ft ha nd) side.
Such a n inpu t to a load ed rotor wo uld tilt the
thrust vector opposite to the direction of the roll,
thereby creating a mo me nt tending to return the
aircraft to the proper roll attitude. In the zero or
low g condition, howeve r, rotor thrust is virtually
non-existent and no restoring mome n t r esults from
tip path tilt. The unwary pilot, with the instincti ve
left lateral input, wo uld quickl y cause the rotor to
contact the mast. The torsio nal dri ving load , in
conjunction with be nding, the n causes a mast
failure. Need we say mo re?
How does one avoid this situation? By avoiding
low 0 1· zero g conditions, o f course. H owever , if yo u
inadvertently find yourself in this situation , how ca n
you make a recover y?
T he first concern must be restoration of the
thrust vector, i.e. reload the rotor. Once rotor
thrust is restored , the pilot will regain normal
a ttitude contro l through th e use o f cyclic pitch.
What is the quickest a nd safest method fo r
(cont'd on page 22)
Aviation Safety Digest 11 5 I 21
�Mast bumping in helicopters
(cont'd)
reloading Lhe rotor system? While both aft cyclic
and collective inpuls will reslore rolor thrusl,
collective application will also ch ange engine power
output. Extensive flight tests have indicated the
possibility of rotor under-speeds or gearbox overLorques (depe nding on altitude) when u tilising
collective to recover from low g roll. Yaw trim
difficulties were a lso found likely. Aft cyclic
application, however, was found Lo quickly restore
control power and decrease right roll rate. Since
this method was found not to cause a ny of the
disad va ntages of the collective recover y, a ft cyclic is
conside red the best method of thrust restoration.
Once thrust is regeneraled in this manner, left
lateral cyclic may be used in roll recovery without
fear o f mast bumping. However, it must be stressed
that the o nl y safe way Lo a void mast bumping a nd
subsequent separation of the rotor head is
prevention , i.e. the avoidance of low g situations.
T he foregoing recovery technique is not instinctive
a nd the re is no room for error in its application.
To sum up:
• If low g or zero g is encountered, an
uncommanded ri ght roll can be expected .
• The a pplication of left cyclic will not stop the
roll, and can rapidly cause the hub of an
unloaded rotor to strike, distort and possibly
sever the mast, resu lting in main roLOr
separatio n.
• Rotor thrusl must be restored before lateral
cyclic effecti veness can be regained .
• Aft cyclic should be used first, to re-load the
ma in rotor.
• Above all, avoid low g situa tions in teetering
rotor helico pte rs! •
*
*
*
Hazardous attitudes
A research team at the Embry- Riddle Aeronautical
University in the United States has isolated five
accident-inducing ' hazardous attitudes' based upon
a stud y of 600 accidents. The team concluded that
the live were a causal factor in 94.6 pe r cent o f the
accide nts studied.
T h e hazard ous attitudes were ide nti!'ied as:
• Feeling of invulnerability, wrapped around a
belief that accidents only h appen to o the rs.
• 'Macho' a ttitude, in which the pilot feels th at
taking a potentially h azardous course 'will make
a bigger g uy of me'.
• 'Anti-authority', a defiance of instructions by
pilots who dislike being told wh at to do.
• 'Impulsivity', or acting on impulse in a tight
situation ra ther than reasoning o ut the best
course of action.
• 'Out of control', when the pilot fee ls that the
situation has deteriorated beyond his
capabilities and concludes, 'What's the use?'.
Whe n such attitudes crop up only occasionally,
pilots can be trained to resist them. When they arc
compulsive, th ey may prove to be terminal •
(CourtfSJ Flight Safety Foundation Flight Safety Facts and Re ports)
22 I Aviation Safety Digest 115
Churchill Fellowships
The Winston Churchill Memorial Trust was
established in Australia in l 965, the year in
which Si1· Winston C h urchill died. The princi pal
object of the Trust is to perpetuate and honour
Lhe memory of Sir Winston Chu rch ill by the
award of Memorial Fellowships known as
'Churchill Fellowshi ps'.
The aim of the Churchill Trust is to give
opportunity, by the provision of financia l
support, to enable Australians from all walks of
li fe to undertake overseas swd y, or an
investigative project, o f a kind that is not fu lly
available in Australia. Th is opportun ity is
provided in furtherance of Sir Wi ns ton C hurchill's
maxim that: 'with o pportu ri ity comes res ponsibility'.
There are no prescribed qua lifications,
academic or other wise, fo r the award or a
Churchill Fellowship. Merit is the primary test,
whether based on past achievements or
demonstrated ability for future achievement in
a ny walk of life. The value of an applicant's work
to the community a nd the extent to which it will
be enhanced by the applicant's overseas swdy
project are important criteria take n into accounl
in selecting Churchill Fellows. However,
Fellowships will nol be awarded in cases where
the primary purpose o f the app licatio n is to
enable the applicant to obtain hig her acad emic or
·formal qualifications no r to those in a vocation
which offers special o pponunity for overseas study.
Churchill Fellows are p rov ided with a return
economy-class overseas air-tickel and a n Overseas
Livin g Allowance to enable them to undertake
their approved overseas stud y project. In special
cases they may also be awarded supple menta r y
allowances including Dependants' Allowance.
Fifty seven Chu rchill Fellowships were awarded
fo r 1983.
All Churchill Fellows are presented, al an
appropriate ceremony, with a certificate and
badge ide ntifying them as such. The certi ficale
bestows upon the recipient the prestige of being
a Churchill Fe llow a nd , while a Fellow is
overseas, serves to open ma n y doors that wo uld
not otherwise be opened to a private individual.
This could p rovide an opportunity for a member
of the aviation industry to help others in aviation
as a resu lt of their e ndeavour and the assistance
provided by a Churchill Fellowship.
Applications
The Church ill Trust is now calling for applications
from Australians, or 18 years and over, from all
walks of li fe wh o wish to be considered for
Churchill Fellowships Lenable in 1984.
Completed applicaLion forms and reports fro m
three referees must reach the Chu rchill Trusl by
28 February l 983.
People wishing to be conside red for a
Churchill Fellowship should send the ir name and
address now with the request for a copy of the
Churchill Trust's informatio n brochure a nd
application forms to: The Winston Churchill
Memorial Trust (M), PO Box 4 78, CANBERRA
CITY, ACT 2601 •
DangerJ Aerosol cans do EXPLODE
This pressure can of Insect spray exploded when
It was left In the closed cabin of a helicopter
which was parked In the sun.
The ruptured can made a deep Imprint In the
metal liner of one of the aircraft's doors before It
punched a hole In the windscreen.
CAUTION: Do not expose to
heat exceeding 500 Celslus. Do
not puncture or Incinerate can.
WARNING: The temperature In a closed aircraft cabin can easily reach and exceed the 50°
Celsius temperature limltatlon prescribed to ensure pressure can safety. Temperatures as
high as 80° Celsius have been recorded.
Aviation Safety Digest 115 I 23
�
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1983
-
https://collections.heritageoftheair.org.au/files/original/3d1ad13119d9cd73141a983d60e8fdb1
0f13a73e8696fb3a66c7d1bee016e229
PDF Text
Text
Regulations for Operation of Aircraft
-!lh~USTRALIA, 1 &
~~<«·«:-"
- - commencing January 1920 -
(
•
l. Don't take the machine into the air unless you
are satisfied it will fly.
2. Never leave the ground with the motor leaking.
3. Don't tum sharply when taxiing. Instead of
turning sharp, have someone lift the tail around.
4. In taking off, look at the ground and the air.
5. Never get out of a machine with the motor
running until the pilot relieving you can reach
the engine controls.
6. Pilots should carry hankies in a handy position
to wipe off goggles.
?. Riding on the steps, wings or tail of a machine
is prohibited . .
8. In case the engine fails on takeoff, land straight
ahead regardless of obstacles.
9. No machine must taxi faster than a man can
walk.
10. Never run motor so that blast will blow on other
machines.
11 . Learn to gauge altitude, especially on landing.
12. If you see another m achine near you, get out of
the way.
~
13. No two cadets should ever ride together in the
~
same machine.
14. Do not trust altitude instruments.
15. Before you begin a landing glide, see that no
machines are under you .
16. Hedge-hopping will not be tolerated.
17. No spins on back or tail slides will be indulged
in as they unnecessarily strain the machines.
18. If flying against the wind and you wish to fly
with the wind, don't make a sharp turn near the
ground. You may crash.
19. Motors have been known to stop during a long
glide. If pilot wishes to use motor for landing,
he should open throttle.
20. Don't attempt to force machine onto ground
with more than flying speed. The result is
bouncing and ricocheting.
21. Pilots will not wear spurs while flying.
22. Do not use aeronautical gasoline in cars or
motorcycles.
23. You must not take off or land closer than 50
feet to the hangar.
24 . Never take a machine into the air until you are
familiar with its controls and instruments.
25. If an emergency occurs while flying, land as
~
soon as possible.
~
.
..
(
~
•
•
-
114/1982
BUREAU OF AIR SAFETY INVESTIGATION
-
•
.·
�Contents
A message from
the Secretary
3
A message from the Secretary
Front cover
4
Wirestrikes: the threat and the defence
Passengers disembarking from a Kendell Airlines Metroliner at
Melbourne Airport.
13
T·VASIS glide slope displaced by fog
14
Controlled flight into terrain at night
17
Confusion in the cockpit
20
Cessna 200 series fuel system malfunctions
22
Shoulder harness
22
Fuel theft
23
178 seconds . ..
Kendell Airlines commen ced business at Fores t Hill Airport,
Wagga Wagga, in 1966 as Premiair Aviation Pty Ltd , engaged In
charter work, flying training and aircraft maintenance.
Scheduled services were commenced in 1971 under the trading
name Kendell Airlines , operating a Piper Navajo aircraft
between Wagga and Melbourne tw ice daily. Since then the
routes Melbourne to Merimbula, Cooma, King Island, Portland
and Warrnambool have been added, and the types of aircraft
operated have included Navajo, Aero Commander and De
Havilland Riley Herons. Today the company operates a fullypressurised fleet of three Swearingen Metro aircraft on 100
flights weekly to and from Melbourne Airport , carrying abo ut
50 OOO passengers per year.
Swearingen Aviation Corporation, manufacturers of the Metro
11, is a subsidiary of Fairchild Industries, a diversified
American aerospace and communications company wh ich
builds military and civilian aircraft, spacecraft and aircraft subsystems, industrial and elec tronics produ cts and operates a
domestic satellite communications system.
(Photograph by Daryl Sheridan)
TI
Aviation S'.ifet_y Digest is prepared by the Bureau of Air Safety
lnvest1gat1on m pursuance of Regulation 283 of the Air Navigation Regulations and is published by the Australian Government Publishing Service. It is distributed free of charge to
Australian licence holders (except student pilots), registered
aircraft owners and certain other persons and organisations
having an operational interest in Australian civil aviation.
. ,,
l
(5.oem1
Unless otherwise noted, articles in this publication are based
on Australian accidents or incidents.
Readers on the free list experiencing problems with distribution or wishing to notify a change of address should write to:
The Publications Distribution Officer,
Department of Aviation,
P.O. Box 18390. Melbourne, Vic. 3001.
....
·~··
~
_g_ c - _
-~c
op
L -
""1lj"r /
00
[
-
- 59'4.3"'
(18.09 ml
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Reader contributions and correspondence on articles should
be addressed to:
The Director,
Bureau of Air Safety Investigation,
P.O. Box 18390.
Melbourne Vic. 3001.
© Commonwealth of Australia 1982.
RM79/30212(3) Cat. No. 82 3049 7
Printed by Ruskin Press, 552-566 Victoria Street, North
Melbourne, Victoria.
2 I Aviation Safety Digest 114
Back cover
Maurice Farman 'Shorthorn '
(Photograph courtesy of Mr Doug Pardey)
.J)
/
-----
~ ---
Aviation Safety Digest is also available on subscription from
the Australian Government Publishing Service. Enquiries and
notifications of change of address should be directed to:
Mail Order Sales,
Australian Government Publishing Service,
P.O. Box 84. Canbe_rra. ACT 2600.
/
~+-
~~ O~{()O O O OD
~ c.~
-
1s· _ . J
(4.~7ml
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I
-
(
On 7 May 1982 the Prime Minister, Mr Fraser,
announced new administrative arrangements which
included the creation of the Department of
Aviation. He also announced that Mr Wal Fife
would be Minister for Aviation. I was appointed as
Secretary to the Department. Two Deputy
Secretaries were also appointed.
Included in the new arrangements was the
formation of the Bureau of Air Safety Investigation
which became effective on 7 June 1982. The Bureau
consists of a Central Office and five Field Offices
which are outposts of the Central Office
organisation. They are located at Brisbane, Sydney,
Melbourne, Adelaide and Perth. The
Surperintendents of the Field Offices are directly
responsible to the Director of the Bureau, who , in
turn, reports to me.
The Bureau will continue to investigate the
circumstances of aircraft accidents and incidents to
determine the factors involved, recording the
resulting information in a computer-based system for
data analysis directed towards accident prevention.
The air safety investigation system is only as good
as the information available to it. The quality of its
output is largely dependent upon the extent to
which it is supported by members of the industry.
Some years ago, in an effort to encourage people
to report and share the knowledge gained from their
experiences, it was declared that immunity from
punitive action would be granted in certain
circumstances. Also it was declared that no person
calling for assistance when encountering difficulties
in flight would incur punitive action by the
Department. Unfortunately statistics on the
submission of reports suggest that the industry is still
not bringing to light all the incidents which could
contribute to overall improvements in safety.
The policy of immunity was last restated in
Aviation Safety Digest 100. It has been suggested in
the industry that the policy no longer exists. That is
incorrect . It is therefore appropriate to again restate
clearly the objective of air safety investigation and to
reiterate previous assurances about immunity and
the reporting of air safety incidents.
The fundamental objective of the investigation
of an aircraft accident or incident is the
prevention of accidents and incidents - it is not
the purpose of this activity to apportion blame or
liability. I will not impose any punitive measures
upon any person who, because of navigational or
other difficulties, requests assistance from airways
operations units. In addition, I will not impose
any punitive measure on the originator of the air
safety incident report for any of his actions in an
incident which is brought to the notice of the
Department solely by his submission of such a
report. This undertaking is given to encourage the
submission of reports of situations and
circumstances, which could lead to safety
improvement measures, that would not otherwise
have come to notice. In cases where other parties
are involved, eg. airways operations units, other
aircraft etc, clearly, immunity will not be
applicable.
There is a further exception to the overall
policy on immunity. If the investigation of any
incident, however it comes to notice, shows that
persons or property have been exposed to danger
because of a deliberate or contemptuous disregard
for the law, or because of dereliction of duty
amounting to culpable negligence, it dearly will
be necessary for me to consider initiating punitive
action against the person concerned.
Every reported occurrence will, of course, be
investigated to the extent necessary to determine and
record the facts for it is absolutely necessary to
ensure that proper information is available for
future analyses in our continuing accident
prevention efforts.
Finally, it has been brought to my attention that
there have been statements by various sources that
publication of the Aviation Safety Digest is to be
discontinued. I hasten to assure you that this is not
the case.
The frequency of the magazine has been restricted
in recent times by difficulties in recruiting and
retaining suitable personnel within the Bureau of Air
Safety Investigation. The consequent staff shortage
resulted in a situation where the exigencies of dayto-day accident investigation had to take precedence,
temporarily, over the requirements of the Digest.
The Bureau is very conscious of the need to
maintain regular production of this important
magazine and every effort is being made to improve
the frequency of publication. I can assure you that
the Aviatz"on Safety Dz"gest is seen to be an essential
part of the Commonwealth's accident prevention
program and there has never been any intention of
discontinuing its production .
(C.W. Freeland)
Aviation Safety Digest 114 I 3
�Discipline
Wire strikes: the threat and
the defence
The first requirement for safe conduct of any
flight, whether agricultural or not, is a strong
sense of discipline and self preservation. This
applies to all phases of the flight from aircraft
preparation to shutdown.
A pilot cannot for a moment allow himself the
luxury of relaxing the discipline, no matter what
the temptation may be. As the old adage goes,
'Rules are made for the protection of idiots and
the guidance of wise men', but a pilot who bends
the basic rules has only two chances. He may
survive, with a lot of luck, and learn to be a Jar
wiser pilot to carry on to greater things. Wz"thout
luck, the result is either death or permanent
injury, with its pain and suffering. Both not only
affect the pilot concerned, but also reach to
relatives and friends.
t
4viation Safety D.igest 114
outlining general precautions applicable to low
level operations and the types of wires likely to be
encountered , add little to what m any pilots
already know.
It therefore became clear that the best possible
advice for preventing wire strike accidents sh ou ld
come from those who have done just that over a
long period of time . Accordingly, a number of
very experienced agricultural p ilots through ou t the
country, with upwa rds of 20 OOO hours in the role
and 200 OOO sor ties flown, were invited to review
their long flying careers and explain for the
benefit of all concerned - especially pilots new to
the industry - how they have managed to escape
serious injury or death through wire strikes.
T he exercise proved most rewarding. Nearly all
the pilots surveyed responded with detailed,
modest accounts of the practices and procedures
they have diligently m a intained with obvious
success. Not surprisingly, perhaps, there was
general accord on a number of factors considered
vital for the avoid ance of wires. These a re set out
in logical sequen ce as follows. The supporting
comments in each case are a composite of views as
exp ressed by th e experts themselves.
*
I am t:onscious of wires. I don't like the bloody
things! Most of my flying has been done in sparsely
populated areas where there are fewer wires unlike Manawatu, Waikato and Taranakz~ although
I have flown in these areas as well. I put my lach
of wire strikes down to the fact that I am always
conscious of them. I use the system of repeating to
myself in a loud voice, 'power lines' when near
potentially dangerous ones.
*
I consider power lines to be the biggest hazard by
far in top-dressing; especially to experienced
*
p ilots. Although they learn to cope with other
Discipline, being a trained condition of the mind
hazards such as downdraughts, downwind taketo obey a system of rules, is your primary means of offs, out-of-wind landings on short strips, etc., the
survival in a relatively hazardous occupation. It
wire hazard zs more likely to catch them unawares
not only bozls down to learning to identify the
because of boredom or complacency. One can
likelihood of wires and then to spot them; it is
always pull off a reasonable landing or take-off
equally important to develop good habits as a
when half asleep, but if one hits power lznes when
result of personal discipline at a very early stage in half asleep it zs probably curtains. My advice to
one's career.
the young pilot is to think power lines every time
he flies low or up a gully. Thzs is how important it
*
On every briefing, whether it be to topdress, spray
zs to me. The signal starts up zn my head every
poison or supply drop, I disciphne myself to ask,
time I head up a strange gully. Even then I
' ... are there any wires - power, telephone, flying sometimes get caught out. I t takes a long time to
fox, television or electric fence?'. T hen, whilst
develop the habit, but it zs the only answer.
flying out I wat ch all the ridge tops. If I see a post
*
or pole, I orbit to locate the wires and align them
(or their sag) with a vzsual reference before
continuing work.
Acknowledgement is made to the New Zealand Civil Aviation safety magazine Flight Safety for
approval .to reproduce this article. It is offered as a follow-on to the article 'Wire Strikes', presented in
Aviation Safety Digest 108. Although some of the pilot comments in the article refer to New Zealand
locations, the situations, hazards and recommendations apply equally to operations in this country.
Collision with wires h as long been recognised as
one of the greatest hazards facing the aerial work
pilot. Oth er than legislating for the non-erection
of any wire or cable above ground level - a most
unlikely en actment - it seem s there is no
possibility of eliminating entirely this man-made
threat to air safety. In consequence, our wire
infested country must continue to be regarded by
pilots as a hostile environment in which to oper ate
aircraft a t low level.
Much has been written from time to time on
the subject, and, as is often the case, it h as been
easy to be wise after the event and perhaps
condemn a normally conscientious pilot for an
indiscretion h e had no intention of committing.
Avoiding overhead wires involves many factors
relative to a particular operation, and it is up to
the individual pilot to assess the situation a nd
decide on the safest p lan of action in the
circumstan~es . However, the continuing high
number of wire strike accidents does give cause for
concern and suggests that some pilots engaged in
this role are eith er not fully aware of, or are n ot
a dhering to, common safety practices and
procedu res.
Most articles on the subject, apart from
with wires. If there is a wire problem on a
particular job, I don't consciously remember
them, but the awareness is there. If I suddenly
realise the awareness is gone, maybe even while
landing, it is like the fuel state shock of reremembering. The memory lapses may last only
about .fz've seconds or even less.
'
( ,)
'~emory
u
and '"'' :11reness
Once you have identified the obstacles on a
particular farm or area keep them etched in your
memory for future use. But remember that the
human memory is not infallible. Each time you
approach the area go about the procedure of
asking and observing to refresh the memory, and
also to find out if any new lines have been
erect ed.
*
Some of the most experienced pilots have struck
wires, so the problem zs not one of an experience
gap between the old and the young. It is a matter
of being aware that wires and aeroplanes don't go
together!
*
I suppose it must be part of my background
thinking, similar to my fuel management. I always
seem to have an internal clock which gives me an
image of my position, time -wise, in my fuel
endurance. If, for some reason, I become unaware
of my fuel state, the sudden realisation is lz"ke a
shock or a physical blow, even though I may still
have an hou(s fuel left . The same thing happens
Once I have located all kno1i1111 wires in an area, I
then rely purely on memory. However, for those
with any tendency to JorgetfulnesJ, a warning
placard next to the trip meter, or the word wires
on the job card, are e.¥cellent reminders.
*
Aviation Safety Digest N'~ '· ~
�I don't really know if I have any speci'al formula
except wire awareness. The need for this
awareness was brought home to me b;y a horrible
experience I had many years ago. A close friend
and I were working adjacent strips. He was flying
a PAJBA and I a 225 FU24. The strips were a
mile apart and we were working load for load.
The main 200k V lines ran between us, with me
turning away from them and the other aircraft
turning around them.
After our lunch break I was finishing my first
sowing run when I looked over toward the other
strip. The PA18 was becoming az'rborne. On my
next glance I thought, 'Bloody hell, he 's forgotten
the wires!' I yelled at him in sheer futilz'ty, and at
that moment he impacted. The Cub stopped in
the air with a blinding flash and was left
dangling, caught up in the wires, then caught fire.
After a Jew seconds the blazing aircraft
plummeted to the ground. There was no hope of
my frz.end surviving that inferno.
That experience early in my career still lives
with me and contributes greatly towards my
constant awareness of the presence of wires and
their hazards.
*
Try to be conscious of wires at all times. One does
tend to forget or become complacent about them,
and it is only by reading reports and articles on
wire hazards, and talking about them, that tends
to keep them in one's mind. I must say I have
been known to talk aloud to - or rather about wires. It is an effective reminder.
Briefing
*
Most aerial work pilots, at some time in their
career, have experienced the situation where a
client has assured them there were no wires or
obstacles to be wary of, only to be confronted with
an awkward situation after crossing the boundary
and turning over the neighbouring property. Don't
rely implicitly on what you've been told - carry
out your own inspection as you work.
*
I had commenced operations on a particular
property where the sowing runs wer.e parallel to
the road. After completing three loads I began
working up quite a steep slope to a high ridge,
and the farmer, who was assisting me with the
loading of the aircraft, casually asked me not to
knock down his t elephone line. After inquiring
further about this hazard, I was informed there
was a telephone line running at 45 degrees to my
sowing runs. On my next load I located the wire,
which ran alongside the road to a point where it
cut across the farm and over the ridge. The
roadside poles blended in with the boundary
fencing and were very difficult to pick up.
I later reflected on how lucky I'd been not to
have struck that wire. Since that experience, I
have always made a point of ensuring that the
farmers bri.ef me properly on all overhead wiies on
their properties.
It pays to have a check list or questionnaire
demanding such information as the location of
power lines, telephone lines, electric fences and
flying fox es on the property.
rv ion
To my mind, the avoidance of unres st&rts on the
airstrip before flight with a positive inqu:iry to the
farmer on the nature and location of wires, not
only in the treatment area but also to arid from
the airstrip. During the substJquenl sun>8y, all
those wires must be vi... ,.,, • 1ocated .
*
6 1 Aviation Safety Digest 114
Wire strik es often occur when power p oles are
diff icult to see because they are hidden by trees.
These accidents commonly take place between the
farm house and out-buildings, where the last pole
is often obscured by a tree or hedgelin e - a
classic example of not being able to identify the
location of wires by the position of poles. Other
accidents commonly occur through striking
secondary wires on the same poles (if you are
flying under the main wires) or striking earth wires
(if you are going over the top). Milking sheds and
pump houses should be treated with the utmost
suspicion and be investigated for emanating wires
if they are not readily seen. Tall structures such as
windmills, aerials and some power poles should be
checked out for guy wires.
As for on-the-job briefings, it pays to ask again
about wires - even for experienced pilots who
have flown in the district on many occasions. I just
ask 'Anything new since last time?' Generally, new
wires include those connected with television
installations, electric fences and sometimes flying
foxes. I've had a fright or two with flying foxes
when they've been erected for running hay bales
across a gully. They are usually temporary things
or used only in the winter and spring, and even
the farmer can completely forget they are there.
(
downdraughts, tur bulen ce and the location of
wires. I bear th ese in mind the whole tim e I am
workin g. If I can't see the wires I picture them as
I would the downdraughts, etc.
*
I have done mostly top-dressing and little,
spraying, but I think the most significant reason
why I have avoided wires is that I am always
conscious of them, especially since the advent of
low cost electric grass-fencing. Nowadays, before I
dart through an inviting looking saddle on a ridge
I look to see that the farmer hasn't decided to save
himself a couple of poles by stringing a high
tensile feeder line across from top to top.
*
With my trainees I always impress upon them the
*
golden rule of never venturing into gullz'es or down
Some old pilots I know can sniff out wires without
rivers, etc., without a prior reconnaissance from a
being objective about it. Sheer cunning tells them
safe height. Whenever flying down a valley keep a
where to look for those hidden wires, or steers
good lookout along the rz'dges above for poles,
them away from places they haven't already
pylons, etc. They stand out agaz'nst the sky better
checked out. For example, an old pilot would
than the ground. And always remember that just
never go through a gap in the trees unless he looks because you've had a good look around the place,
at the other side first. He would not skid his
doesn't mean you have located all wires. They can
aircraft around a pole where the line changes
leap out from the most unexpected places. One
direction unless he checks for guy supports.
thing worth mentioning is that z't is all too easy to
miss a wire during a reconnaissance if z't is in close
*
My second wire strike occurred when I arrived at
proximity to another, especially if it is smaller and
the strip first thing in the morning. I was landing
strung with longer spans. It's almost as if the mind
into the east and promptly flew through a set of
has subconsciously 'fixed' that particular area and
wires the local power board had erected since I
the eyes look further afield once the major or first
left the previous morning!
lzne is located.
Watch out in saddles on a ri·dge that has a
*
fence line running up to it. Sometimes there is a
One of the rules I apply to my own operations is
wire running across the saddle. Try to follow every
n ever fly low unless I have first flown over the area
wire you observe slung across a gully or over any
at higher level to assess the flying conditions long span.
looking for likely area of updraughts,
*
u
c!
By continual observation of the terrain as habit, it
will become second nature to anticipate where the
local authori.ties are likely to erect power or
telephone lines in relation to the siting of houses,
wool sheds, cow sheds, etc. This is relatively easy
on flat terrain, but is more difficult in hill country
where lines can be, and usually are, slung from
ridge to ridge with no poles in between. It is
t~erefor.e essential to commence work by flying the
ridges first to locate poles and observe the lie of
the lines between the poles. It iS very dangerous to
fly up or down a gully at low altitude before
as~ertaining first that the area is, in fact, clear of
wires.
*
Never venture into valleys without• prtor reconnaissance from a ~fe height. Locati()(I of pole• must be identified prtor to
low level operations as wtres may be 'firtually impo stble to see. When working m 'tllleys maintain a good lookout along the
s/t.yl/ne.
Aviation Safety_ Digest 114 17
�My own feeling regarding prevention of wire
strikes is to have a thorough local knowledge of
existing wires and to keep in touch with the
authorities responsible for the erection of new
wz'res. Our operations people, as well as the pilots,
endeavour to do this and make sure that all are
kept informed of wz're locations at all times.
*
There is a height at which a particular az'rcraft
type will give its maximum spread. Below that
height the swath width is reduced, but above it
the swath width will remain about the same. It
may therefore be more desz'rable to fly the aircraft
at heights above the optimum and enjoy that extra
margin for error. This applz'es more so if there are
wires zn the sowing area. This procedure refers of
course, to top-dressing of fertilisers only spraying is a different ball game and zs best left to
helz'copters.
WIRESTRIKE
l
"
*
Don't guess the amount of sag of a lz'ne if you
can't see z't. Maybe it is tighter and higher than
you estimate. If in doubt, fly higher. It also pays
well to, as much as possible, do all turns above
ridge top height, thereby avoiding the possibility
of tangling with lines that may be slung taut
across a gully.
If there are
W1re entanglement around the pitch change rods can make
control extremely difficult and In some cases Impossible,
with dire consequences.
Prior to landing at a farm house {helz'copters)
check wh ere the power and telephone wires come
in. Look for any wz'res to the pump house, and in
hzll country look for a television aerial on top of a
hz'll. When approaching the hover, if near a shed,
check for electric fences. Watch for odd telephone
insulators or broken bottle necks on posts, sticks,
pieces of timber or poles stuck in the middle of a
fence line. They sometimes have wires strung
along them. Along boundaries and roadsides
observe the power or telephone pole cross-arms.
See that they are zn unison. Beware of cross-arms
that are at 90 degrees to the usual run. They
invariably carry wz'res running from the main lz'ne
to a shed or other out-building. The first pole in
this secondary lz'ne always seems to be hidden
behznd a tree.
I have found it wise to check out the property
myself prior to commencing operations. This has a
dual purpose. It enables me to remind myself of
the property owner's boundary fences and
obstruc,tz'ons and to check for any new obstructions
erected since my last visit, and provides an
opportunity to check that there are no left-behz'nd
stock on the airstrip paddock.
·
*
8 I Aviation Safety Digest 114
8
!
A
!
*
wires in the treatment area, they
should be sighted at every procedure turn before
the run-in to spray. This allows yo'IJ to concentrate
later on the lining up and planning of the next
swath, and to antidpate the proximity and
resighting of the wires at the appropriate time.
Where possible, poles should be used as szghters
during your approach to th e wires as it is Jar
easier to judge both th e closing speed and the
direction of the wires.
Pull-ups should be made early, and the effects
of weight and air temperature on performance
constantly assessed. However, I have always
maintained that, provided there i's reasonable
clearance, it is easier and safer to pass under the
wires rather than pulling up and over them if they
are located in or on the boundary of the treatment
area.
(
Wire strikes are common on the return for
another load. The pilot tends to relax, and his
returning flight path and height can be a little
erratic as he is not monitoring aircraft
performance as he was on the way out. We all
tend lo be a little inattentive under these
circumstances.
etum
1rd to "rest up a bzt before the
next load Hedgehopping back to the strip
ac hie rs a negligible time saving and markedly
mcrpa..~P~ fat;.gue and exposure to wire stn'kes.
*
Plan a flight path that ensures adequate wire
clearance. This will look after you should you
temporarily forget about the wires. Any deviation
to planned track and altitude should be avoided
or investigated first.
*
Power line strikes were more frequent a few years
ago when dustier materials were being dropped,
causing us to contour sow if it was windy zn order
to get a little more work done. Today with the
more granulated supers it is not necessary to fly so
low - in fact, it zs preferable to sit up higher and
achieve a better spread.
*
Wherever possible, it i's better to fly under power
lznes than to try and scramble over them - as
long as you know your aircraft and are
experienced enough to judge your height above
the ground. Power lines are easier to see against
the sky than merged in with the ground. I have
several farms in my area with high tension lines on
them, and I jz'nd it much safer to fly under these
lines, alongside the pylons. This way one has
plenty of reference - the pylon, the wires and the
ground.
*
*
0
Constantly change focal length of eye scan ahead - long
distance fixation can cause you to 'look through close m
w/fes. An accident occurred here when the pilot saw the
lower power /me lAJ m the distance but lost sight of the
higher mam spur power line (BJ m the potato paddock
Pilots should constantly change the focal dz'stance
of their eye scan along the projected flight path. It
is very easy to fix one's eyes on the end of a
paddock and 'look through' wires that are within
or just outside the boundary. It i's also quz'te easy
to fix one's eyes for relatively long periods on
objects that gain a pilot's attention, such as
loaders and airstrip s. This lessens the chance of
seeing intermediate obstacles such as wires.
*
Ask the farmer about wires during briefing then
sight the poles during each sowing run, and if the
wires are not visible, fly as hz'gh as th e poles.
Never let the farmer or other operators talk you
into flying lower than you feel happy about.
*
I think that if a pilot can see he is going to hit
power or other lz'nes, he should try to hz't them
with the propeller. Never, never, with the wings in
a turn if it can humanly be avoided.
*
During spraying operatz'ons I must have flown
under literally hundreds, if not thousands of
power and telephone lz'nes. My method is to make
an initial reconnaissance around the field to
determine the height of the wires, the spacing of
Aviation Safety Digest 114 19
�the poles, location of trees and other obstacles, the Some farms have a real confusion of wires running
run of all lines (a surprising number go to ground
across them. If the farmer wants his spray job
for various reasons) and then confirm the
done in the area of the wz"res, explain that you will
feasibil£ty of the planned spray pattern. After
have to spray from above them. Don't duck and
that, the height of the lines becomes secondary to
dive, there's bound to be a set of wires that you
their location, and it's only a matter offollowing
have forgotten a bout. Don't try to 'just miss' the
two golden rules:
wires as they are too diffz"cult to see properly for
• Look a fair distance ahead of the aircraft and
judging distance during momentary glances.
never focus too close.
*
• Never look up at the wires as they approach, but Try and spray parallel to the wires. If at any stage
concentrate on maintaining height relative to
you have to spray toward them, pull up well clear
the ground.
of them and complete the unsprayed section later
with one or two parallel runs. It may take longer,
*
but it is much safer.
However, spraying under lines is a different kettle
of fish to top-dressing under them: first ly because
the terrain being dressed zs often undulatz"ng and
At sunrise and sunset, and for about one hour or
the lines not of uniform height, and secondly
so
each side, it is almost impossible to detect lines,
because of the .need to maintain at least a
poles, pylons or obstacles when flying directly into
moderate height for spreading purposes, thereby
the sun. It is better to leave the job untz"l another
lessening the separation between the aircraft and
time, for surely you are courting disaster by trying
the lines. I generally discourage top-dressing
to fly blz"nd. Where possible always plan runs so as
beneath power lznes, although there are some
to avoid thzs situation.
situations where it zs the best procedure.
*
Another hazardous situation exzsts where wires are
the ~ame height, or hzgher than sowing height and
a clzmb has to be made every time to avoid them.
In thzs situation if I cannot see both poles clearly I
use some other prominent feature as a marker to
start cl£mbzng. A reassuring back-up procedure is
to ge~ an early altimeter check on the height of
the line. I've used thzs method when working in
poor visibility (rain, dust, sun, g lare, etc.), and
also as a safety factor when a good visual sighting
of the wire can't be made but other markers are
clearly visible. However, the altimeter should
never be used as the sole method of assuring wfre
clearance.
*
Ill
When flying fr~m job_ to base or from job to job,
fly at a regulation height above terrain. It is
amazing the number of wire stn"kes that have
o~curred during positioning flights. Many ag.
pilots seem to thznk that the regulations for crosscountry flying do not apply to them. I can relate
several cases of wire strikes that would not have
happened had the 500 ft terrain clearance
minimum been adhered to.
*
The need.for prior reconnaissance of an area from
a saf~ height to locate wires applies equally when
ferrying from base to job, and vz"ce versa. In many
areas there are logical bad weather routes from
the job to base and it pays to know these
intimately. Every now and again it pays to follow
them when coming home in good weather
conditio'!'s t~ keep a"!' eye on any developments poles gozng zn, erection offlying foxes, etc. It
takes a lot of worry out of the next bad weather
trip. I had an incident with a set of 11 OOO volt
power lines back in 1966 when I had only been in
the area a short time. After I had done about an
hour's work one morning, a front moved in with
accompanying low cloud and light rain. I then
headed back to base, but being unfamiliar with
the area I elected to follow the Manawatu River
which I knew passed close to the aerodrome.
CJ_nfortunately, I s~ruck the wires wh£ch span the
river between a hill on the northern side and a
pole set well out on a flat on the southern side.
Fortunately, the Beaver struck the wires with the
propeller and chewed its way through them, with
only moderate damage to the wings and fuselage.
*
One of my more serious power line 'strikes was
caused by disorientation in rain. I ran into a rain
squall in the middle of a sowing run. I knew the
power lines were there, but thought I had miles of
room above them and steep turned away. I was
horrified to see the wires wrap around the port
wing. The only thing to do in a case like thzs is to
keep turning - which I did. The wires eventually
shorted and burned through, but not before I had
pulled down two concrete poles and a hell of a lot
of wire. This brought home the lesson - 'exercise
extreme caution when flying low in rain'. I was
amazed at the misjudgment I had made in height
because of it. This zs a very important factor 10
e"'
....
you of s~ch hazards on properties adjacent to his
boundanes. All these wires and obstructions must
?e visu~lly located during the subsequent
mspect10n.
Treat with caution any assurances that there are
no dangerous wires on the property. Farmers are
apt to forge~ about old or seldom used lines, flying
fox~s, electnc fences, etc. and even newly erected
aenals and cables. Carry out a further inspection
if in doubt.
Use a check list to ensure that no item is
ove~l~:>0ke~. If i:iecessary, use a map of the area to
positively identify and mark in each hazard.
Reconnaissance and observation
Continual observation of the terrain in your
genera~ ~rea of operations enables early
recognit10n of current or likely erection of power
and. telephone lines in relation to farm building
projects.
Before commencing work, make a
reconnaissance of the total area at a safe height.
Positively locate all power pylons and power and
telephone pol~s. Look for those partly obscured by
t:ees, those with cro~s-arms denoting secondary
Imes and those formmg part of a fence line.
J?etermine ~he directi?n of wir~ runs and spur
Imes (especially electnc fence Imes or feeder lines
slung between saddles on ridges). Locate radio
and television aerials, supporting guy wires on
structures, and flying fox cables. Beware of
s~aller wires slung in close proximity to major
Imes.
l
dangeluuS.
Summ ....
Fro~. the f?regoing, the principal safety factors for
avoidmg wires may be summarised as follows:
u
Discipline
Without a strong sense of disciplin~ you are bound
to succumb to temptations that inevitably lead to
dangerous, unplanned manoeuvres. Get to know
the safety ru_les and adhere to them rigidly on
every operat10n.
Memory and awareness
Be constantly aware of the existence and lethality
o~ wires on every spraying/sowing run, on every
flight to and from the treatment area, on every
ferry flight to and from base. Don't let
complacency, boredom or sleepiness interfere with
your mental attitude to wires. If some form of
memory jogger is required use any method that is
guaranteed to gain and maintain your attention.
Etch WIRES into your mind.
Briefing
A preflight briefing from the farmer is essential to
confirm the nature and location of all wires and
~ignificant obstructions on his property, especially
m the treatment area and along the route to and
from the airstrip. He may also be able to warn
Wire strikes oflen occur when the poles ere h1d<Mn by trees
An Alrlruk on final approach to /find m the cl.ar area to
the south east of the strip struck double power lines, the
supporting poles of which were hidden amongst the trees
shown in the photograph.
This accident was reported Tft~ v1.afion Safety Dfgest 102
"
. ') /' Aviation Sa f&ty D'igest 114
. Aviation Saf<Jty Digest 11 .1 '
•
�T-VASIS glide slope displaced by
fog
l
A clean, polished windscreen is vital
Flying technique
• Allow an extra margin for error by flying sowing
runs higher than the optimum for maximum
spread - the swath width will remain ab~ut _the
same, particularly when granulated matenal 1s
being used.
• Where possible, make all turns above ridge top
height to avoid wires slung across gullies and
saddles. Wires in the treatment area should be
sighted on every procedure turn before the run
in.
• Where possible, use poles for sighting wire runs,
and if the wires are not visible fly as high as the
poles. Whenever poles cannot be seen clearly,
use some other prominent feature as a marker
for the pull-up point.
• Don't guess the amount of sag in a line that is
difficult to see. If in doubt, fly higher. It also
pays to get an early altimeter check on the
height of a wire.
• When establishing a pull-up point to clear wires
don't forget the effect of high gross weight and
air temperature on aircraft performance.
• Endeavour to make runs parallel to wires.
Where you have to spray toward wires pull ':1P
well clear and finish untreated areas later with
parallel runs.
• With high power lines it is sometimes safer to fly
under them: providing there are no other
obstructions, th~t you look well ahead when .
approaching, that you never look up at the wires
as you pass under and that you concei:itrate on
maintaining height a bove ground. This_
.
technique is mainly applicable to spraying ~ It
is not generally recommended for toi:i- dressm~"
• Where a farm is covered by a profusion of wires,
don't 'duck and dive' - maintain a safe h eight
above them at all times, no matter what the
effect on spread.
.
• Maintain extra vigilance when returnmg for
another load, and also during final 'tidy-up'
runs . The tendency to relax and be inattentive
to detail at these times is a common cause of
wire strikes.
12 / Aviation Safety Digest 114
• Develop a 'rubber neck'. From take-off to touch
down keep looking up and down,- left to right everywh ere - for wires , obstructions and
possible forced landing sites.
• Constantly change focal length of eye scan
ahead - long distance fixation can cause yo u to
'look through' close-in wires.
• Finally, if you are going to hit wires of any_ sort,
try to hit them with the propeller, never with
the wings in a turn.
Weather factors
Never plan or make runs into a rising or setting
sun. If you can't avoid sun glare by comple ting
the job across or down-sun , delay the operation
until such time as glare conditions become less
haza rdous.
Beware ·of operating in rain showe rs:
misjudgment of height , and distance from .wir~s
can result through disorientation or visu al 1llus10n.
Ferry flights
Maintain regulatory minimum height above
terrain during all ferry flights. If a bad weather
route can be followed carry out a reconnaissance
in good weather to identify the location of newly
erected wires and other hazards.
C'
u ion
That so many highly experienced agricultui:al
pilots have succeede~ in flyin~ for ~o. long:, m such
a demanding role without senous IIlJUry 1s clear
proof that wires can be avoided, simply b_Y p lacing
self preservation above all else . Other aenal wo rk
pilots, whether experien ced or n ew to the.
industry , would do well to study a nd put mto
pratice the precautionary meas u res adopted by
the experts in this field.
It really boils down to esta blishing a personal set
of safety rules and disciplining oneself to adhere to
them at all times •
(__,
Since its introduction some 15 years ago, T -VAS IS
has been installed at a number of airports and
aerodromes throughout Australi a, proving itself to
be an invaluable approach aid, at night in
particular, at the many locations where there is
neither high intensity approach lighting nor
electronic approach slope guidance. However, a
recent incident a t Perth Airport illustrated an
inherent limitation of visual approach slope
indicating systems such as T -VAS IS, VAS IS and
PAPI in conditions where visibility is affected by
airborne moisture. During a night approach the
flight crew observed a full fl y-down indication on the
T-VASIS while the aircraft was on the correct glide
slope according to the ILS. T he fly-up lights were
also visi ble, but only as 'pin point' sources at very
low intensity.
Approaching Perth, the Captain had prepared for
an ILS approach on the basis of the terminal
information and approaches m ade by preceding
aircraft. Visibility was reported to be variable and as
low as 1200 m etres in fog patches. At Parkerville,
the airport and city lights were visible, though some
blurring a nd 'halo' effect were evident. Shallow fog
patches were also evident around the airport but
visual conditions seemed to prevail. At the start of
the ILS approach to Runway 24 the crew could see
all of the runway lights, and at 1200 feet the
Captain took m anual control of the aircraft to make
a visual approach. At about 800 feet he started to
ease down to obey a T-VASIS fly-down indication;
however, the first officer, who was monitoring the
ILS, advised that the aircraft was going below the
glide slope . The Captain regained the ILS glide
slope and continued with the ILS approach. The
approach was completed without further incident,
but the T-VASIS continued to provide a false flydown presentation throughout. At a bout 50 feet at
the beginning of the flare the aircraft entered
shallow fog and visibility was reduced considerably,
but all of the runway lights remained visible and the
Captain had no difficulty making a visual landing
nor in maintaining the centre line during the
ground roll .
T he T- VASIS installation was flight tested the
next day a nd found to be operating correctly.
It has been recognised for years that there can be
problems with the interpretation of visual landing
aids when visibility is affected by airborne moisture.
The most common problems experienced arise as a
consequence of two basic effects that result from the
p assage of light through water droplets. These are
diffusion, from the refraction of the light beams as
they enter and leave each water droplet, and the
scattering of the light by reflection from the surfaces
of the water droplets. The net result is that a light
beam may be seen at an angle different from the
correct one and a light source may be visible over a
wider angle in space. T hese phenomena are evident
in the halo effect seen around individual lights and,
at times, the ability to see both the fly-up and flydown lights of the T-VASIS at the same time.
However, the Perth incident cannot be completely
explained by the process outlined a bove. In this case
there appears to h ave been a general downward shift
of the T -VASIS glide slope, accompanied by the
other effects as well. T his was probably brought
about by refraction as the light beams passed from
the fog laden air in the lower 50 feet into the clear
air above. T he light originating in the dense lower
layer would have been refracted downwards as it
passed into the less dense air above, thereby
effecting the observed downward shift of the glide
slope.
T his incident is published to refresh pilots'
knowledge of the limitations of visual approach slope
indicating systems and to help preserve the good
reputation that T -VASIS has earned since its
introduction. However, like all navigation systems,
T -VASIS and the other systems have limi tations
which it is important to remember. In this case, the
limitation is that they a re likely to produce
erroneous indications in fog or mist and the systems
cannot necessarily be relied upon in these conditions.
Any unusual indication, such as fly-up and fly-down
lights being visible at the same time or a
pronounced halo effect around the lights, should be
sufficient reason to discontinue use of the visual
approach slope indicating system, as it is usually not
possible to know the overall effect on the system
unless the runway is also servd by ILS •
Aviation Safety Diges t 114 / 13
�Controlled flight into terrain at night
This account of a night landing accident at a remote strip illustrates some of the dangers and difficulties
a pilot can encounter when making a night approach, and reinforces once again the validity of
conforming to standard circuit procedures - particularly when operating under difficult conditions.
T he pilot of the Piper Navajo, concerned about the
close proximity of high ground, deviated from an
established h abit pattern in the execution of his
descent to circuit height and then joined the
circuit on base leg. He then misinterpreted visual
cues to his height before turning onto final and flew
into rising terrain short of the strip. Fortunately,
neither occupant of the aircraft was injured.
The purpose of the flight was to provide an aerial
ambulance service to a remote station where an
injured child required medical attention. T he
north/ south strip into which the operation was to be
conducted was adequate for the task, but high
terrain some three kilometres to the west dictated
that all manoeuvering be done to the east.
Lighting was provided by portable flares
supplemented by car headlights shining on the
threshold and the upwind end of the strip.
The weather at the time of the accident was
VMC, but a layer of high cloud made the night very
dark, and ground features were not discernible from
the aircraft. Consequently, the strip lighting was the
only external reference available to the pilot for
orientation. Observers on the ground noted the
presen ce of some low cloud in the area and a
weather report to this effect was passed to the pilot
while he was enroute.
The topography of the area was dominated by a
3627 foot mountain rising abruptly out of otherwise
relatively flat terrain. The strip ran parallel to this
escarpment at an elevation of 1300 feet.
On receiving notification of the flight requirement
at about 1750 local time the pilot alerted the nurse
who was to accompany him and then proceeded to
the airport to prepare for the flight. He obtained
the relevant area forecast and filed an IFR flight
plan for the flight out and back. T ake-off,
departure and cruise were without incident.
During the flight the pilot prep ared an approach
plan, taking into consideration the high ground and
the reported wind. A few minutes before his ET A
he descended from his cruising level, 5000 feet, to
minimum safe altitlide and saw the strip lights when
they came into view from behind the mountain
shortly afterwards. After over-flying the strip , he
cancelled Sarwatch and started his pre-planned
descent on an easterly heading. His intention was to
descen d to the east until 1000 feet above circuit
height and then turn inbound and track to a left
base position while continuing the descent to circuit
height. Believing the strip elevation to be 1000 feet
he set that level, rather than circuit altitude, on the
assigned level indicator as a reminder. He then
continued the descent outbound to 2000 feet and
comm enced his turn t~ ~he l<;ft. Although now less
than 1000 feet AGL, he continued to descen d
1 ' · ,.11
1iation
Safe ty Diges t 114
towards what he now took to be circuit altitude
while tracking inbound towards the base position .
Approaching 1500 feet altitude (approxima tely 300
feet AGL) , he selected gear down and completed the
landing checklist. Shortly afterwards the strip lights
disappeared briefly. When they reappeared, they
seemed to the pilot to be flashing on and off,
leading him to believe that he was flying through
the patches of low cloud reported earlier. He
thought at the time that this might cause difficulties
on final but did not believe that he had a problem
at that stage of the approach. At about this time the
station homestead called him on a private network
HF radio suggesting he land into the south (which
was already his intention) and the nurse expressed
her concern about the proximity of the high ground,
as she had done a number of times during the
flight. The pilot answered the radio call and,
appreciating the anxiety in the nurse's voice, leaned
forward with his face against the windshield, from
where he saw the faint outline of the mountain and
indicated to the nurse that they were clear of it.
Very soon after that, the aircraft hit trees. The pilot
applied full up elevator, but without significant
effect ; the aircraft continued to plough through trees
and scrub for 180 metres before coming to rest
about two kilometres from the strip .
Accident Site 1200 ft
f I'
110 kts
Analysis
This accident happened because the pilot lost his
awareness of the strip elevation and then
misinterpreted available visual cues to his height .
However, most pilots would agree that he was faced
with a very demanding exercise, and to put the
accident into perspective we should examine it in the
light of all the significant factors. Let us look at
these as they were identified by the investigation and
discuss them in relation to their effect on the
outcome of the flight.
Pilot experience. The pilot held a commercial pilot
licence and Class One instrument rating. He had
accumulated some 3600 hours flying experience in
general aviation - but only 70 hours of that was at
night. He therefore did not have a large store of
night experience to draw upon in his planning and
execution of this approach and landing.
Furthermore he had not landed at this strip at
night, but he was sufficiently familiar with it
through d aylight operations to appreciate the
position and nature of the high ground and to know
that he could manoeuvre to the east of the strip with
safety. However, the fact that he could not see the
mountain in th e darkness caused him more concern
and apprehension than the situation warranted and,
as will be seen later, this distracted him from his
primary task of flying the aircraft.
/ (radio call}
Mountain
3627 ft
Strip 180°
1300 ft amsl
Landing gear down
1500 ft amsl
Lights Disappeared
Hdg.090°
2000 ft amsl
Cancelled SARWATCH
Set 25" 2500 RPM 15° Flap
Commenced Descent
4700 ft amsl Lowest Safe Altitude
·Avi ati on Safety Digest 11.41 "15
�Descent plan. The descent plan was sound in
concept - but it was deficient in detail in that it
lacked positive altitude checks from which the pilot
could quickly and unambiguously monitor terrain
clearance. That deficiency , when combined with his
deviation from an established habit pattern (when
he set strip elevation instead of circuit altitude on
the assigned level indicator) set the scene for
disaster. He said later that after setting the assigned
level indicator he did not look at it again during the
descent; however, the fact that he descended
outbound to 2000 feet and then continued to
descend inbound strongly suggests that at some time
during the descent he subconsciously misinterpreted
the significance of the 1000 foot setting and took it
to be circuit altitude. Had he been more specific in
his plan and identified specific altitudes rather than
the more general approach of selecting heights
above circuit altitude he would not have entrusted
the integrity of his descent plan entirely to his
memory of the circuit altitude throughout the
descent. For example, had he planned to descend
outbound to 3300 feet and then turn inbound and
continue descent to 2300 feet (circuit altitude) a
constant awareness of the strip elevation would have
been largely unnecessary during the descent, and the
opportunity for misinterpretation and confusion
minimised.
A second, but perhaps somewhat academic, point
is the pilot's understanding of the strip elevation: he
thought it was 1000 feet, when the actual elevation
is 1300 feet. Any discussion on the effect this error
may h ave had would, however, be hypothetical: use
of the correct elevation may h ave only displaced the
accident site closer to the strip. But on the other
hand had he got closer in, the pilot might h ave
correctly interpreted the visual cues and recognised
the error in circuit height in time to recover.
Circuit procedure. The. pilot elected not to fly a full
circuit. He was too high to join on crosswind from
overhead the first time and believed that he would
have to fly too close to the mountain to make a
normal circuit entry later. This is but one of the
decisions and actions that point to his apprehension
over his inability to see the mountain in the dark.
By not flying a circuit, and in particular the
downwind leg of a circuit, he denied himself the
opportunity of starting his final approach from a
familiar position relative to the flare path , and set
himself one of the most difficult judgement tasks a
pilot can experience. He also lost the only
opportunity he had of detecting the mistake in his
descent p lan and of overcoming the visual illusions
that can distort pereeption under the conditions that
prevailed at the time. (See Aviation Safety Digest
111 page 10). By flying a circuit and starting his
approach from a familiar position and height
relative to the runway a pilot does not have to rely
totally on his perception of the flare path picture for
orientation. Furthermore, when an aircraft is
established on the correct glide slope from the start,
deviations are more easily recognised and, as stated
earlier but worthy of repetition , visual illusions are
less likely to intrude on a pilot's perception of his
position.
Misinterpretation of visual cues. At no time during
the approach did the pilot suspect that he was low.
16 I Aviation Satetv · ·
This was almost certainly a result of his erroneous
belief that he was still above circuit altitude, but was
compounded by the difficulties inherent in the
interpretation of a flare path picture and the total
lack of any visual reference other than the flare
path. He commented that when he lost sight of the
flares it did not occur to him that he might be low.
Pre-conditioned as he was to expect low cloud in the
area, that became the logical explanation in his
mind for the disappearance and, later, the flashing
on and off of th e flares - even to the point of his
expecting difficulties later on final. That analysis of
the situation was interesting in its predictability;
history has shown that in circumstances where an
aircraft has gone low on glide path and the runway
lights have disappeared because of intervening
vegetation or terrain, the pilot has almost invariably
attributed the disappearance to low cloud or fog
patches. This apparent reluctance of the human
mind to recognise or accept that things may not be
going according to plan dictates but one course of
action to a pilot if the lights disappear during a
visual approach at night - he must climb
immediately!
Distractions. The pilot allowed himself to be
distracted from his primary task - flying the
aircraft - at a critical stage of the flight. Shortly
before impact his attention was diverted from the
flare path on two occasions; fi rstly to answer a radio
call, and secondly to search for the high ground in
response to a concerned enquiry from his passenger.
To answer the radio call he had to reach back
into the aircraft cabin, where the HF radio was
installed, and locate the handset. Then to find the
mountain he h ad to lean forward with his face
against the windshield out of the glare of the
instrument lights and peer into the darkness.
The radio communication was unimportant and
its timing inopportune; the position of the high
ground was similarly unimportant at that time since
the aircraft was to the east of the strip and had not
deviated in p lan from the intended approach path.
The pilot should therefore have known where the
mountain was withou t having to look for it. It
should be noted that the terrain into which the
aircraft flew was not associated with the high ground
of concern and, in fact, the elevation of the accident
site was 100 feet below the strip elevation.
Other factors. One other point worthy of discussion ,
but not actually a factor in the accident , was the
p ilot's cancellation of Sarwatch before landing, when
the facility was there for him to do so on the
ground. Nobody on the ground was aware of the
accident until about an hour after the event, when
the pilot and his passenger arrived on foot at the
station homestead. They had walked a bout three
kilometres from the accident site. T h e people at the
homestead were by then trying to find out why the
aircraft had not landed, and would eventually h ave
established that it was missing, but by then valuable
time would h ave been lost; time in which, under
other circumstances, lives might have been lost •
Confusion in the cockpit
The two pilots and one passenger on board a commuter aircraft miraculously escaped with
only minor injuries when the aircraft flew into the side of a mountain during an NOB approach.
The aircraft was destroyed.
History of the flight
(
"'
The flight was a scheduled commuter service which
involved a number of enroute stops. It was also
being used for route familiarisation for a pilot who
had joined the company only two days earlier. H e
was flying the aircraft under the su pervision of the
pilot in command, who was acting in the capacity of
route training pilot.
The first stage of the flight was completed without
incident. The aircraft was landed off a visual
approach during which the pilot in command had
pointed out significant local features to the other
pilot and virtually talked him through the approach .
Take-off and departure for the second stage were
similarly uneven tful, but the weath er deteriorated
for the cruise with the aircraft in cloud most of the
way at 5500 feet, the lowest quadrantal level above
minimum safe a ltitude. Because there were no radio
navigation aids at the destination aerodrome the
intention was to make an ND B approach to another
aerodrome about 20 kilometres away and proceed
visually, weather permitting. The aircraft was
descending, supposedly on this NDB approach ,
when it hit the mountain (see chart overleaf) .
outbound track. Meanwhile, the pilot in command
had become occupied, first with a radio call that
took some time to complete and then with the fuel
management tasks. He did not monitor the pilot's
entry to the approach and remained unaware of the
track being flown; however, during the descent he
glanced out of the side window at one point an d saw
water through a break in the cloud. As the aircraft
would have been over water on the correct track he
was satisfied that all was well and, on completion of
his fuel management task, concentrated on looking
outside to assess the cloud base when they became
visual.
The pilot flying the ap proach did not feel any
concern u ntil he was about to start what, in his
mind , was the proposed early procedure turn at
2500 feet, when he noticed a 3752 foot spot height
on the approach chart just ou tside the 10 mile arc.
He then realised the danger of the situation they
were in , alerted the pilot in command, and applied
maximum power. However, the combined efforts of
the two pilots were too late. The aircraft hit the
trees and crashed into the 30- 40 degree slope of the
mountain side.
Cockpit activity during the approach
Impact information
Cruising altitude was m aintained un til the pilot in
command obtained a visual fix through a hole in
the cloud a bove five miles north of the NDB, when
a descent was commenced.
The pilot under supervision was flying the
approach. When asked b y the pilot in command
what his intentions were he explained that he would
intercept 120 degrees inbound to the aid, fly the
procedure turn depicted on the approach chart and
then fly the approach according to the published
procedure, ie. descend outbound on 300 degrees to
1900 feet then reverse course t hrough an 80 degree
procedure tum left and track inbound on 120
degrees, continuing the descent to the minima. To
this he received a reply something like, 'Forget the
tum , get straigh t into the descent'. At that time the
aircraft was over the NDB at about 5000 feet
heading 120 degrees. The intention the pilot in
command meant to convey was to forget the first
procedure turn and intercept 300 degrees outbound
from a right tum overhead. H e then, because they
were higher than the published altitude at the start
of the approach, told the pilot to turn inbound early
at about 2500 feet in order to avoid going too far
out.
The pilot misunderstood these instructions and ,
believing that he was to be talked through a nonstandard approach, went straight into the descent on
120 degrees, the reciprocal of the p u blished
The aircraft broke up on impact and one fuel tank
exploded, but the main wreckage continued beyond
the area of the fire. T wo smaller fires broke out
near the engines but these apparently died out
quickly without spreading to the fuselage or wings.
Fortunately, the impact forces were greatly
attenuated by the dense canopy of vegetation into
which the aircraft crashed . The two pilots suffered
only m inor injuries. The passenger was uninjured.
Photograp h courtesy of The Sun.
Avn.
1
f£1ty Digest 11A i 1 7
�Discussion
MNM SAFE ALT 58 0 25NM
3752
~:NM
5
·.·.
Bearings are Magnetic
Elevat ion s in Feet
AMSL .
USE QNH
NOB
400
1900
'<?o o, .__
_ _
MNMAli
NM BY DME
10
NM FROM NOB
10
8
6
2
5
0
0
2
4
6
5
8
10
10
12
14
16
15
C..1
)
.
non-standard pattern. He did not question what he
As a starting point for discussion of this accident we
understood to be an instruction to descend
can say that the accident would not have happened
outbound on 120 degrees for a number of reasons:
if the pilot had flown the published approach
he was not familiar with the terrain and therefore
procedure - an academic observation, perhaps, but did not appreciate the danger of descending in that
one which must be m ade. More importantly, we can direction; he perceived the comment of the pilot in
say with some degree of certainty that the accident
command to be a clear instruction to fly the p attern
would not have h appened if either pilot had been
that way and did not suspect that there had been
flying the aircraft by himself. We need then to
any misunderstanding; he knew that there was at
examine how the p resence of a second pilot in the
that time a shortage of fuel in the area and believed
cockpit could have had such an influence on the
the modified approach was a time-saving measure;
operation that the published approach procedure
he believed that the approach was based on the
was ignored and the aircraft flown towards the
other pilot's wealth of experience in the area and
mountains instead of over the sea.
assumed that it would be safe. Fu rthermore, in the
T he pilots. Both pilots held commercial pilot
belief that his flying was being monitored, the lack
licences with Class One instrument ratings. Both
of comment from the training pilot as the approach
were experienced in single-pilot IFR operations, but
progressed would have been taken as confirmation
neither had any significant multi-pilot crew
that he was complying with that pilot's intentions .
experience . •
T he pilot flying the aircraft was an experienced
Comment
general aviation p ilot with some 2500 hours flying
It would be easy to say that the pilot should have
experience. H owever , he was only a new employee of followed the published procedure; and so he should.
this company, having joined it on the Monday
With few exceptions, approach patterns are
preceding the accident, when he also completed his
constructed as they are for very good reasons of
aircraft type endorsem ent . His total experience on
safety. It is also easy with hindsight to say that he
the aircraft was that gained during the endorsement
should have questioned the instruction to modify the
plus some flying on Monday afternoon and Tuesday, pattern, but when we consider the points already
during which he flew for about ten hours on
discussed and the fact that this was only his third
scheduled services with a route training pilot and
day in the company, the pilot und erstandably had
afterwards flew one service by himself. On
some reservations in qu estioning the j udgrnent of
one acting in a position of relative authority.
Wednesday, the day of the accident, he was being
checked on routes not covered on Monday or
However, with all the factors considered, and even
T uesday: these covered areas in which he had no
tempered with hindsight, there can be little doubt
previous experience or local knowledge.
that the major contributory factor in this accident
The pilot in command was also an experienced
was inadequate monitoring of the approach on the
part of the pilot in command. One of the
general aviation pilot with over 6000 hours flying
experience. He had operated in the area of the
requirements explicit in the exercise of command is
acciden t commercially for about five years and knew
the acceptance of the responsibility that goes with it.
That responsibility does not allow the pilot in
the topograph y intimately. He was not employed as
a route training pilot on a regular basis; he acted in
command to simply assume that the other pilot will
do the right thing.
that capacity infrequently and was not experienced
in it. He understood that his duties in this capacity
were to introduce the pilot to the company agents at Conclusion
each port and to familiarise him with the ground
Thi~ accident serves a useful purpose in illustrating
procedures. H owever , in this case he knew that the
the mherent dangers of two- pilot operations without
other pilot had not flown in the area before and
stand~rdised procedures, with inadequate b riefing
considered it his responsibility to also show him the
and withou t clear, unambiguous commu nication . It
app roaches and point out significant terrain. He did
also clearly demonstrates how essential it is for there
not consider it his d uty to continuously monitor the
to be a complete and clear understanding of their
other pilot's flying or operating procedures.
respective roles by the two pilots involved. With the
introduction in the near future of two pilot crews in
Briefing. There was no pre-fligh t b riefing in
relation to the operational procedures, the types of
m any aircraft that have been traditionally operated
by one pilot, a number of pilots will find themselves
approach to be flown, or the terrain at any of the
in a formal 'crew' environment for the first time.
ports for the day's flying. Furthermore, the pilot
Operators will need to recognise the potential
flying the approach commen ted later that he had
problems and prepare pilots in command , in
been unable to self-brief because of the sheer pace
particular, for their new role through a
at which things were happening in his new
comprehensive training program supported by a
employmen t. T he extent of the briefing for this
good operations manual •
app roach related to a discussion of the procedure to
be followed should they not be able to continue to
their destination.
The approach . The pilot flying the approach had
intended to fly the published procedure, un til the
pilot in command instructed him to 'forget the
tum'. At that point he believed that he was going to
be talked through the approach, as had happened
previously, and that he was being instructed in a
'f Y [Jfgest 11./i
�Cessna 200 series fuel system
malfunctions
Redesigned fuel system (Cessna model T21 ON)
REDUCED
CAPAC IT Y
STANDPIPE
(TYP}
FUEL QUANTITY
TO FUEL QUANTITY INDICATORS
FUEL QUANTITY
TRAN SM ITT~
~NSM ITTER
VENT CROSSOVER
.-.-:·:-:- -:-,.·.·!·.·.·.··=·:·:
In the absence of any other evidence to explain
Unexplained fuel system malfunctions in Cessna 200
the
abrupt power loss, an examination of overseas
series aircraft have been the cause of several engine
failures through fuel starvation over the years. In the experience was indicated. T he United States
latest occurrence the pilot of a Cessna 210D was only National Transportation Safety Board has for some
time been concerned about the number of accidents
eight minutes from his destination when the
involving
Cessna 206, 207 and 210 aircraft as a
aircraft's engine suffered a complete power loss
resul t of power loss caused by fuel starvation, and
without warning.
requested the manufacturer to construct a
When the engine lost power the pilot selected the
representative fuel system mock-up of those models
other fuel tank and attempted to restart, but when
so
that its operation could be studied . In the course
he was not immediately successful he selected a
of
the tests that followed, it was found that all
suitable landing area and set up a forced landing
systems
worked satisfactorily most of the time, but
pattern. When confident that he would reach the
selected site he went over the re-start checklist again, under some not clearly understood conditions,
vapour locking of the fuel feed system would occur.
and this time was successful in restoring engine
In an aircraft this would result in complete power
power. He then diverted to a nearby airstrip and
loss.
The tests established that the action of selecting
made a precautionary landing without further
another
fuel tank could cause the vapour locking to
incident.
occur,
but
it also revealed that this same action
After landing, he inspected the engine an d fuel
could
clear
an established vapour lock. However, the
system , but could find no reason for the failure.
occurrence
of
vapour locking was seen to be
T hen, after conducting an extensive trouble-free
unpredictable. Experimentation revealed that the
ground run, he discussed the incident with a
problem could be solved by the installation of
maintenance facility and decided to continue the
separate
vapour return lines from the fuel selector to
flight. The short flight to his destination was
each
tank.
This discovery suggests that the condition
uneventful.
Inspection of the fuel system revealed the presen ce arises from fuel vapour and released air returned
from the fuel injection unit accumulating in, and
of lint-like material in the fuel filters - enough to
finally filling, the fuel collector tank and supply
restrict fuel flow. But this finding did not explain
lines.
the abrupt power loss and , as a possible cause, was
The question arises as to whether the reported
inconsistent with the power recovery and normal
incident
was caused by the foreign matter in the
operation later when the pilot had changed tanks .
fuel,
by
vapour
locking, by a combination of the
However, significant amounts of this lint-like
two,
or
by
som
ething
else. With regard to the latter
material have been found in several other Cessna
thought, there is no evidence to suggest the existence
single-engine aircraft, and for this reason it is worth
of a third problem.
dwelling on this subject briefly before examining
The problem of the collection of foreign m aterials
another possibility. The following extract from the
on
the fuel filter screens can be controlled by
United States FAA General Aviation Alerts No. 41
cleaning them at freq uent intervals until the foreign
of December 1981 summarises the problem. It
material is eradicated. This action is recommended
concerns the result of a fuel filter inspection on a
for new aeroplan es and for other aeroplanes after
Cessna TU206G, an aircraft with a similar fuel
h aving flexible fuel cells replaced; in both cases
system to the Cessn a 21OD.
flushing of the fuel system before the aeroplane is
Inspection of the fue l strainer following an infligh t engine
placed in service will also help remove any
problem disclosed t,he filter was covered with a clo th-li ke
accumulations of the troublesome material .
fibre or lint. The finger screen in the fuel distributor also
The more serious problem, however, is
contained some of the sam e material. This was the th i1·d
unpredictable vapour locking. The manufacturer
such occurrence that this operator had experienced with
has, at various times, issued Service Letters and
new aircraft. A Cessna dealer advised that a significant
other instructions detailing fuel system modifications
amount of fibrous lint-like material has been found in the
fuel filters of 22 various Cessna single-engine aircraft over
and engine handling instructions to prevent fuel
the past six months. Time on the aircraft averaged 30
system vapour locking, and also suitable emergency
hours. Inspection of low-time aircraft for this condition is
procedures to clear the fuel system should it occur.
recommended .
But the only fully reliable remedy is modification of
Investigation of the Cessna 210D incident revealed the fuel system by the incorporation of vapour
return lines from the fuel selector direct to the main
that a fuel cell had been replaced some 30 hours
fuel
tanks.
prior to the inflight powc loss. It is suspected that
Reported incidents in this country which could be
this n ew cell was the soll!"c., 'Jf the lint-like material
attributed to vapour locking have been assessed from
found in the fuel filtf~r~ .
(cont 'd
Aviation Safe~· Jigest
011
VENTED
FILLER
CAP (TYP}
VENT
DRAIN
VALVE
I
I
..
I
I
I
;:::;:::!:;:::;~:::::· FUEL SUPPLY
lililIIIIID ~:~~:SRFE~~LRN AND
lIIIJ[
I
I
I
DRAIN
VENT
-
-
-
FUEL QUANTITY INDICATORS
I
I
~---CODE~~~
\ I
\ I
MECHANICAL LIN KAGE
\ I
....__ ELECTRI CAL CONNECTION
\ I
\ I
,,\_ ___ __ __ J
\I
FUEL TANK SELECTOR PANEL
AUX FUEL
PUMP SWITC H
---------
J
@
FUEL
ON - OFF
CONTROL
•
TO
ENGINE
ENGINE DRIVEN
FUEL PUMP
(j
A
MIXTURE
,,,,,,-------~CONTROL
FUEL FLOW
INDICATOR
(Right Half of
,,,-""'
::::----------0A
FUEL/ AIR
CONTROL UNIT
'-----.-.:'>."'_
THROTTLE
_J
__J
ENGINE
Note: The fuel tank selector valve h as NO off position . The fuel ON-OFF selector is a
p~sh/pull
control.
page 22)
,'10.1 ~ ·9ty Digest 114
�Shoulder harness
Fuel theft from aircraft
There have been sporadic reports of fuel theft from
Do you always wear your shoulder harness when
light aircraft over the years, but recently the
flying? The pilot involved in this accident does,
problem has taken on some of the characteristics of
now, after learning the hard way.
an epidemic. At one general aviation airport alone,
The helicopter was engaged in transporting
supplies to line cutting crews. As it was climbing out thefts totalling more than 1000 litres were reported
over a heavily wooded ridge the pilot heard the rotor in one week. Disturbing as this is, however, a more
sinister aspect is appearing in conjunction with these
speed beginning to decay. He confirmed this by the
RPM gauge and entered autorotation, turning away activities. In two recent occurrences in Queensland
from the hill. Flaring into the 70 foot trees along the not only was fuel stolen , but the drained tanks were
filled with water in an effort to disguise the crime.
side of the ridge he was able to cushion the
The potential for disaster needs no elaboration.
helicopter as it settled, but the machine received
As a consequence of these developments the
substantial damage and both occupants received
importance
of conducting a meticulous pre-flight
serious injuries. They were found by another
inspection of the aircraft needs emphasis. Pilots must
company helicopter which was aided in the search
be aware of the possibility that their aircraft has
by the ELT signal.
been tampered with and should check, in particular,
Extensive testing of the engine and associated
components revealed no reason for the loss of power. that the liquid in the tank is in fact unadulterated
fuel , that the quantity is as expected, and that a
The following is a direct quote from an interview
thief, or would-be thief, has not caused damage to
after the accident: questions by the accident
the aircraft or fuel tanks during such activities.
investigator, answers by the pilot.
The best insurance is, of course, prevention. But
Q. Would you like to make a comment about
as
we know, that is not always easy. For example, a
shoulder harnesses?
lockable fuel cap is a rarity, and continuous
A. Shoulder harnesses, yes. The machine had
surveillance of all aircraft parked in fhe open is an
shoulder harnesses in it. I was not wearing them, to
impractical ideal. Moreover, the trust and concord
my regret. I feel that whoever I fly for, whatever
machine I fly, from now on I demand shoulder
that has been part of aviation since its inception is
harnesses or I don't fly. I make my living flying and the very thing that works against the apprehension
of these criminals. Against this background it is
I feel that they are a defirrite advantage if you ever
are in an accident, and in this particular accident I
difficult for a pilot to accept that any person would
don't feel I would have got face lacerations. Possibly approach an aircraft with malicious intent and he
therefore remains silent when in other circumstances
I wouldn't have got my back jimmied up either. It
he might challenge a person's presence. Obviously,
would have stopped the forward slumping and
all suspicious activity around an aircraft should be
movement of my body.
Q. Can we quote you on that last statement if we
investigated.
The Department of Aviation and other
have to, to prove a point about using shoulder
aerodrome owners do provide a degree of security at
harnesses?
some locations, but aircraft owners, operators and
A. Yes you can •
pilots should be aware that security of their property
Courtesy Transport Canada ·synopses of Aircraft Accidents 2121'
is their own responsibility and should take
appropriate precautions •
Cessna 200 series fuel system
malfunctions
(cont'd)
the airworthiness viewpoint as not frequent enough
to warrant a mandatory requirement for installation
of a separate vapour return line to each main tank.
Airworthiness Directives AD/Cessna 210/31, 45 and
47 are all intended to minimise the occurrence and
effects of vapour locking.
A redesigned fuel system has been incorporated in
all 1982 model Cessna 210 aircraft and is shown
schematically in the diagram. Forward feed lines
have been increased in diameter and the selector
system now ensures that vapour return goes direct to
the main tank being used to feed the engine. It is
not known whether Cessna will make this system
available as a retrospective kit for earlier models.
Cessna 206, 207 and 210 operators who are
concerned that their type of operation could give rise
to vapour locking problems should be aware that
local modifications have been approved which
introduce sepa.rate vapour return lines to the main
tanks. These represent simpler solutions than would
be achieved by retrofit to the 1982 system. Operators
considering the fitment of such a modification can
obtain further details from appropriate maintenance
organisations •
r . Aviation Safe
Traffic watch
ATC to Aircraft:
'You have traffic at 10 o'clock, 6 miles .'
Aircraft to ATC:
'Give us another hint - we've got digital watches.'
~le se~ands ...
altimeter says you're at 1500 but your map tells you
there's a local terrain as high as 1200 feet. There
might even be a tower nearby because you're not
sure just how far off track you are. But you've flown
into worse weather than this, so you press on.
You find yourself unconsciously easing back just a
bit on the controls to clear those none-too-imaginary
towers. With no warning you're in the soup. You
peer so hard into the milky white mist that your eyes
hurt. You fight the feeling in your stomach. You
swallow only to find your mouth dry. Now you
realise you should have waited for better weather.
The appointment was important - but not that
important. Somewhere a voice is saying 'You've had
it - it's all over'.
n
(
)
' Pilot continued visual flight into adverse weather
conditions. ' Familiar words? For those associated
with aircraft accident investigations they are, for
they summarise the type of occurrence which
continues to cause the greatest loss of life in
Australian general aviation accidents - in spite of
the publicity given to the subject over the years. One
would think that the futility of pressing on in bad
weather should be obvious, but without gelling into
Lhe pilots' minds, the compulsion behind their fatal
decision will remain elusive. This article, courtesy of
Transport Canada, attempts to reproduce the
thoughts of a pilot who gets himself into cloud in
what might be a typical scenario. Read it and if you
are ever tempted to press on in marginal weather
recall its advice. If then, for whatever reason, you
decide to continue , and lose visual contact, start
counting down from 178 seconds. Thal is how long
a pilot who has no instrument training can expect to
live after he flies into bad weather and loses visual
contact - according to researchers at the University
of Illinois. Twenty student 'guinea pigs' who flew
into simulated weather all went into graveyard
spirals or roller-coasters. The outcome differed in
only one respect: the time required until control was
lost. The interval ranged from 480 seconds to 20
seconds. The average was 178 seconds
two
seconds short of three minutes.
Here's the fata l scenario .. .
The sky is o~ercast and the visibility poor. That
reported five kilometre visibility looks more like two,
and you can't judge the height of the overcast. Your
You now have 178 seconds to live. Your aircraft
feels on an even keel but your compass turns slowly.
You push a little rudder and add a little pressure to
the controls to stop the turn but this feels unnatural
and you return the controls to their original
position. This feels better but your compass is now
turning a little faster and your airspeed is increasing
slightly. You scan your instrument panel for help
but what you see looks somewhat unfamiliar. You're
sure this is just a bad spot. You'll break out in a few
minutes. (But you don't have a few minutes left ... )
You now have 100 seconds to live. You glance at
your altimeter and are shocked to see it unwinding.
You're already down to 1200 feet. Instinctively, you
pull back on the controls but the altimeter still
unwinds. The engine RPM is in the red - and the
airspeed nearly so.
You h~ve 45 seconds to live. Now you're sweating
and shaking. There must be something wrong with
the controls: pulling back only moves that airspeed
further into the red. You can hear the wind tearing
the aircraft.
You have 10 seconds to live. Suddenly you see the
ground. The trees rush up at you. You can see the
horizon if you tum your head far enough, but it's at
an unusual angle - you're almost inverted. You
open your mouth to screa.r but . .. •
:;~v
Digest 11& J•lJ
�
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1982
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PDF Text
Text
Aviation
Safety ·
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113/1982
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Editorial
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Contents
Aviation Safety Digest is distributed free of charge
to holders of Australian flight crew licences (except
student pilots), licensed aircraft maintenance
engineers , designated medical examiners,
registered aircraft owners, and other bodies su ch
as licensed flying schools, charter and other
operators, and gliding clubs. In addition, other
organisations may also receive the Digest free of
charge . It was at this latter group that the review
of the free distribution list (Digest No. l l l ) was
principally directed . Those recipients were asked
to complete a questionna ire and return it to the
Department if they wished to remain on the free
list.
The purpose of the review was primarily to
enable us to bring our records up to date an d, if
possible , contain costs by prunin g unnecessary
prod uction.
Aviation Safety Digest is prepared by the Air Safety Invest iga tion
Branch and pu blished for t he Departmen t of Transport through
the Australian Government Pu blishing Service. in pursuance of
Regulation 283 of the Air Navigation Regu lations. It is
distributed by the Departmen t free of charge to Australian
licence holders (except studen t pilots), registered aircraft
owners and certain ot her persons and organ isations having a
ves ted operational interest in Austral ian c ivi l aviation.
3 Editorial
Response to questionnaire in Digest 111
4 Navigating the lanes of entry
6 Long range intercom
6 Thermos flask hazard
Readers on the free li st experienc ing prob lems w ill1 distribution
or w ishing to notify a change of address should write to:
7 Helicopters and grass fires
8 Pilot contribution:
'You're not on your own'
The Publicat ions Dis tribulion Officer.
Department of Transport,
P.O. Box 18390, Melbourne. Vic. 3001.
9 ILS glide-s lope pointer stuck
10 Fuel tank vents
12 Inadequate maintenance leads to gear-up
landing
13 Objects ejected from aircraft during flight in
turbulence
Aviation Safety Digest is also available on sybsc ription from the
Australian Governmenl Pub lishing Service. Enquiri es and
notifications of change of address should be directed to:
Mail Order Sales.
Australia n Government Publishing Service.
P.O. Box 84. Canberra. ACT 2600.
13 Report those incidents
Subscriptions may also be lodged w ith AGPS Bookshops in all
capi tal cities.
14 Pre-flight pointers
Reader cont ri butions and correspondence on articles shou ld be
addressed to:
20 Complacency leads to navigation error
21 Thunderstorms
22 Spark plug fouling
23 Carbon monoxide enters aircraft through
defective door seal
24 Index to issues 1-112
Reader comments
The Assistant Secretary (Air Sale ty Invest igation).
Department ol Transpor t.
P.O. Box 18390,
Melbourne, Vic. 3001.
Commonwealth ol Australia 1982.
RM79/30212(2) Cat. No. 8 1 2666 8
Printed by Ruski n Press. 552 - 566 Victoria Street. North
Melbourne. Victoria.
31 The TIGER MOTH . .. 50 years on
In this issue we commemorate t he 50th anniversary on
26 October 1981 , o f the first flight of the DH -82 Tiger
Moth a( Stag Lan e, Middlesex.
t
1
Front cover
VH-BAR. Maitland. October 1978 (Aviation Historical Society
of Austral ia)
Back cover
VH -UTD. Mascot. c . 1937 (Reddall Collection - Aviation
Historical Soc iety of Au strali a - NSW Branch)
2/Avia tion Safety Digest 113
A secondary aim of the review was to canvass
reader comments on the Digest, and to this end all
readers were in vited to complete the comm ents
section of the question naire . We were pleased not
only with th e number of respon ses to this
invitation , but also that the majority of th ose
responses expressed satisfaction with the Digest . In
particular, the present balance of accident reports
a nd rela ted technica l articles received favourable
comment . A frequent remark was that the Digest
is used as a reference library, and in this regard
we have taken notice of both the requests and the
suggestions for specific articles . We are also
ac utely aware of the desirability of producing
more freq uent issues.
Only two readers expressed total dissatisfaction
with the Digest . One was a LAME who b elieves
that it is almost useless to an engineer , and the
other a pilot who took the opportunity,
anonymously, to 'fire a broadside' at the
Dep a rtment and at the same time charge that th e
present style of Digest is, among other things, 'an
insult to professionals'. H e b elieves that we sh ould
return to the 1950s style wit h its emphasis on
'interesting and exciting' accident reports .
There is n o doubt that ai rcraft accidents are of
great interest to those involved in aviation, and it
is a fact that r eading about someone else's
misadventures holds a particular fascination for
m ost of us. H owever , safety education studies and
history h ave proved that th e publication of
accident d etails alone is not necessarily th e most
effective mean s of p reventing further accidents
from simil ar causes . A case in point is the
continuing incidence of weather-related accidents
in the face of all the publicity given to these over
many years .
There is obviously a place for det ailed reports
on accidents and incidents in the Digest , but these
are intended to complement and illustrate articles
designed to prevent the accident from happen ing
in the first p lace. The problem is of course to find
the correct balance.
Several readers expressed a wish for more reader
contributions. This we endorse enthusiastically,
because the promotion of aviation safety is
enhanced b y the dissemination of your ideas and
actu al experiences. But we need to receive
contributions before we can print them .
Contributions need not be literary masterpieces,
n or need they be lengthy. We ask only th at they
contain a safety message.
As a final point , we again invite reader
comments and criticism of the Digest. Our aim 1s
to produce a magazine that helps you avoid
accidents. But we cannot achieve that aim if you
do not read what we wri te or if we write the
wrong stuff; and we can only gau ge th e
effectiveness of wh at we write by listening to
collective reader feed-back. So if you are satisfied
with the Digest, or are dissatisfied and have a
suggestion or a constructive criticism please write
to us. Don't just complain among yourselves or
address your grievance through the medium of a
letter to some other publication . As stated earlier,
our aim is to help you avoid accidents. Help us
achieve that by providing the constructive feedb ack we n eed •
Aviation Safety Digest 113 I 3
•
•
�l
Navigating the lanes of entry
From time to time the incident reports contain
accounts of controlled airspace penetrations by
aircraft transiting the lanes of entry around our
major city airports. In many cases the pilots of
these aircraft are inexperienced and lack local
experience - factors which contribute to their
navigation difficulties. Fre quently though, these
are only peripheral to the more fundamental
problems of inadequate preparation and the
application of unsound or inappropriate
navigation procedm es. Experience and local
knowledge certainly make it easier , but any pilot
who recognises the problems and techniques
peculiar to the task and prepares accordingly can
navigate the lanes of entry without undue
difficulty. However , all too often the pilots rush
through the planning phase of the flight , failing to
devo te sufficient time to permit a complete and
unhurried examination of the task ahead. While
th orough preparation should precede every flight ,
the confines of the lanes of entry demand extra
a ttention if an incident-free p assage is to be
guaranteed. The airborne workload can be high,
and a poorly prepared pilot will be full y occupied
with just the task of navigation and may not be
able to cope in the event of unforeseen
distractions.
The following account briefly relates the details
of one p enetration incident and discusses some of
the significant factors behind it. It is offered not
to castigate the pilot, b ut to illustrate how such
incidents can develop and to introduce some
suggestions for flight planning and navigation
techniques.
The aircraft had departed Moorabbin for a
flight to Ballarat. The pilot intended to track via
the western lane (a narrow corridor only 2.5 miles
wide between Melbourne and Laverton control
zones) to Rockba nk, and then direct to Ballarat,
with Rockbank nominated as a reporting point.
But things did not go as planned . From
somewhere near Westgate Bridge the actual track
flown took the aircraft over L averton and
W erribee, well inside Laverton control zone. At
Werribee the pilot reported his position as
Rockbank. Shortly afterwards, however , he
noticed that his heading was grossly in error and
realised also that he was not at Rockb ank. At
about the sam e time h e was intercepted by an
RAAF aircraft for identification and shortly
thereafter was advised of his position by Flight
Service and instructed to tu rn right and leave the
zone. He was subsequently given navigation
assistance from Melbourne A TC to track direct to
Bacchus Marsh, from where he completed his
flight without further incident.
41 Aviation Safety Digest 113
T his penetration was the culmination of a
number of factors and events, starting with the
p ilot being d elayed by road traffic on his way to
Moorabbin. He arrived at the briefing office later
than he had intended and in his subsequent h aste
did not devote sufficient time to gain a full
appreciation of the weather, made mistakes in his
flight plan computations, and did not check the
completed flight plan for accuracy. His take-off
and departure were without incident, but
approaching the lane he briefly encountered some
light mist which caused him to feel some concern
about the weather at Ballarat, although it was
causing him no difficulty at that stage, n or would
it do so during the lane transit. However, as he
proceeded h e became increasingly concerned
about the appearance of the weather well ahead
and began pondering alternative courses of action
should he not b e able to continue beyond th e
lane . As a result of this diversion he was not
attending to the immediate task of navigation and
did not r eturn to it for some time. By then h e was
well off track and inside the CTR.
Perhaps a more typical example involves the
pilot who does virtu ally no preparation, thinks
about the transit even less, forgets to set his
directional gyro or fails to check the track , and
proceeds to 'eyeball' his way along the wrong
railway line or road. Melbourne's western lane
again provides the setting for an excellent
example. Many a pilot has blissfully followed the
Bendigo railway line from abeam Westgate Bridge
over Brooklyn light straight into Melbourne CTR.
The lanes demand a little more attention to
preparation and navigation technique than those
p ilots give .
The following discussion is addressed primarily
to pilots who do not routinely use the lanes of
entry and to those who may be intimately familiar
with the geography of their home- town lanes but
are considering a trip intersta te. Other pilots
might examine the procedures and techniques
offered and compare them with their own
methods.
Preparation sh ould start with the selection of a
route (although this is, of course, academic if
there is only one lane). But where there is a
choice , several consideration s should be examined
before a decision is made . Don't select a route
n ecessarily because it is marked on the VTC or
because it is the shortest. Prevailing conditions
m ay militate against that one in favour of anoth er
that is more circuitous, but offers easier
navigation, greater separation from controlled
airsp ace, more h ospitable terrain, better weather
and so on.
Southern end of the western lane of entry, Melbourne
W hile selecting the route, identify a feature on
the approach to the lane over which the aircraft
can be accurately positioned to start the transit.
That point should be a reasonable distan ce outside
the lane so that airspace constraints are not
immediately pressing . Make a detailed study of the
weather forecast , n oting specifically significant
weather, visibility, ceiling and wind. Consider the
wea ther in relation to the topography of the lane
and ensure that ter rain clearance is adequate . Be
aware of the turbulence that can be expected with
high winds a t the low altitu des to be flown d u ring
the tran sit and a lso consider the effect a changing
synoptic situa tion might have on the weather
a round the time of the transit .
If preparing a flight plan, take time to check all
computer work, an d when finished thoroughly
check the whole plan for accuracy and
com pleteness. Apply a mental logic check to
heading and groundspeed computations a irborne is not the place to discover that drift
corrections, for exam ple, have been applied in the
wrong sense . If n ot prepa ring a flight plan , check
the relationship between the forecast wind and the
track and develop a n awareness of what th e wind
effect will be.
N avigation technique. The close proximity of
controlled airspace boundaries requ ires the
adop tion of navigation techniques that will permit
precise track keeping throughou t th e transit. This
begins with the aircraft being accurately positioned
a t the start. Aim to arrive over the start point
previously selected with all unrelated tasks
completed . These might include after take-off
checks, a departure or position report , fuel
management checks, copying terminal information
and so on. Check the weather ahead before
leaving the start point and decide whether to
continue or adopt an alternative course of action,
but do not let a decision to continue influence
judgment later on . Have a plan developed to cover
a deterioration in the weather, or any other
contingency that might make it imprudent to
continue. Ensure t hat the directional gyro is
aligned with the magnetic compass, or if a remote
indicating compass is fitted , th at it is indicating
correctly.
Take up the planned or estima ted heading from
the start point and then adjust it as requi red to
avoid straying from track. The aim is to stay on
track and within the confines of the lane by
identifying the variou s features and tracking
visually over them or avoiding them on the correct
side. Use the aeronautical beacons if they are
available , but do no t rely on seeing them . Use
them as j ust another landmark - that is, as a n
aid to navigation , not as a means. Monitor
progress continu ously. Look for navigation features
well ahead and stay ahead of the aircraft. Do not
dwell on finding a particular feature if it is not
seen when expected - start looking for th e next
one while fl ying the best known heading to
maintain track. This is p a r ticularly important
when visibility is restricted . :
Concentrate on navigation, but not to the total
exclusion of other consid erations such as engine
and fuel monitoring. Remember also that the
Aviation Safety Digest 113 I 5
�lanes are focal points, often with two-way traffic
at the same level in a relatively confined area.
Keep an effective lookout going and use the r adio.
Broadcast intentions, listen for other traffic
information a nd be alertjor possible conflictions.
Remember Flight Service does not provide a
traffic information service for aircraft using or
crossing the lanes. Be partic ularly cautious n ear
the designated VFR approach points. T hese are
often used as holding points by a ircraft waiting for
an airways clearance to enter the control zones.
Finally, do not be reluctant to request assistance
if things star t to turn bad . A pilot who blunders
along trusting everything will b e all right in the
end is doing himself, other pilots and A TC a
disservice . Remember that the ATC p ro blem is
greatly simplified and the controller can provide a
better service if he can talk either directly or
through Flight Service to a pilot who is
experiencing difficulties. Furthermore , a timely
request for assistance m ay prevent a penetration
from occurring in the first place .
Conclusion
To many pilots the foregoing recommendations
may appe ar to be unnecessarily la borious,
complicating what is essentially an easy exercise .
At times such a comment m ay b e valid . In good
weath er , for example, an experienced pilot may
well be able to n avigate his way through any of
th e lanes with little or even no preparation.
H owever , the penetration records show that the
lanes can hold hidden surprises for the
experienced and inexperien ced alike . Application
of the principles described will reduce the airborne
~~rkload and allow pilots to devote the ir attention
·~d the n avigation and other tasks immedia tely
associated with the lan e transit .
M any of the reported transgressions into
bordering control zon es wou ld have b een avoided
firstly by thorough prep aration and the
application of sound n avig ation techniques, and
secondly by a timely request for assistance when
difficulties were first exp erienced •
6 I Avia tion Safe ty Digest 11 3
Long range intercom
T he inadvertent transmission on tower frequenc y
of com m ents intended for intercom resulted
recently in a full a lert fo r the emergency ser vices
an d the d eclaration of a distress phase a t one of
our general avia tion airpor ts.
The tran smissions came fro m a helicopter which
was airborne in the circuit for a maintenance test
flight related to blade tracking .. When the a ircraft
was on sh ort final the aerod rome controller he ard
a clipped phrase ' . .. severe vibration . .. ' on tower
frequency. The pilot did no t reply to an ATC
request to confirm tha t op erations were n or mal, so
the controller assumed th at the helicopter was in
trouble and activated the crash alarm. However ,
as the approach progressed the helicopter entered
a hover in a normal m an ner and the pilot
subsequently called on surface movement
frequency, comple tely oblivious to the drama that
surrounded t he last fe w secon ds of the fligh t ,
having not heard the tower 's request to confir m
operations nor m al. T he p ilot explained tha t
during the a pproac h a discussion had taken p lace
with the engineer passen ger, on int~rcom , about
the various vib ration s associated wi th the exercise
at certain speeds. Snip p e ts of th at discussion were
apparentl y transmitted.
The investiga tion of this incident revea led that
inadvertent ra dio transmissions fro m aircraft are
becoming an increasing problem at som e
secondary airports.
Pilots of aircraft in which an intercom facility is
fitted a re therefore u rged to take p articular care
with both their own and , if appropria te, th eir
passenger's radio a nd intercom switch selections •
Thermos fIask hazard
In a recent overseas incident th e cabin attendant
of an unpressurised turboprop twin-engined
aircr aft was scalded b y h ot coffee wh ich sprayed
on to her neck and face wh en she opened a
thermos flask. The coffee was ej ected from the
flask with sufficient force to sp ray adjacen t sea ts
and the cabin roof. For tunately the seats were
unoccupied.
This inciden t is a useful reminder to us th at the
boiling point of liquids lowers under reduced
atmospheric pressure . When the cabin a ttend a nt
opened the flask at altitude, the sudden reduction
of pressure in the flask to ambient a tmospheric
was sufficient to cause the hot coffee to boil
violently.
Crews of unpressurised an d pressurised a ircra ft
alike should take note of this incident an d ensure
tha t due care is exercised when opening thermos
flasks of h ot liquid if the cabin a ltitude is much
above sea level. It is wor th noting that a t 5000 feet
wa ter boils at 95 degrees Celsius, an d a t 10 OOO
feet, a little under 90 d egrees •
Helicopters and ·grass fires
In 1967 Aviation Safety Digest No. 50 featured an article on the danger of ~t:licopters starting fires
when landing in long grass. Following that discussion the incidence of these occurr~nces
reduced significantly, b'ut recently the problem seems to have re-emerged. Three helicopters
have been destroyed and one damaged in a period of less than two years.
In the m ost recent accident the pilot landed his
Hughes 269C in long grass to drop a passenger.
H e was aware of the fire danger and intended to
take off again as soon as his passenger was clear of
the aircra ft. The passenger started to disembark
10 to 15 seconds after touchdown but was
p revented from d oing so by a wall of fire
immediately outsid e the aircraft. He hastily
with d rew into the cockpit. By then the pilo t could
feel the fi re singeing h is own legs as it spread, so
he vacated the a ircraft with his passenger in ho t
pursuit. Both m en th en retreated to a safe
d istance and watched the fire consume the
aircraft.
In an earlier accident the pilot of a Hughes 269
lan ded in an open grassed area to allow his
passenger to disemb ark to check the water level in
a creek some 500 m etres to the east of the landing
site. The passenger, who was the manager of the
proper ty, inten ded to fire the area east of the
creek if there was sufficien t wate r to form a
fire break. The p ilot intended to keep the engine
running du r ing h is passenger's absence . Shortly
after the passenger had departed, the pilot h eard
the en gine run down an d noticed that the grass to
the left a nd rear of the a ircraft was aligh t, with
flames reaching the top of the fuselage . H e hastily
vacated the aircraft through the right door and
retired to a safe distance to watch the aircraft
burn out.
Prior to the accident this pilot d id not consider
it possible for the Hughes 269 to start a fire. He
normally flew Bell 47 helicopters and was conscious
of the possibility with that aircraft , but considered
that the higher ground clearance of the H ughes
eliminated the problem. However, history has
shown that his belief was ill-founded. Six aircraft
destroyed in grass fires since 1967 h ave been
Hughes 269s.
The solution to the pro blem is simple - do not
land in long dry grass . H owever, that migh t not
always be operationally acceptable . Another
solution is offered to Hughes operators by Rex
Aviation , the Australian Hughes distributor, who
have produced an approved drawing (RA-C -1406)
of a plate which forms a h eat shield between the
engine exhaust system and the ground. Operators
might consider this modification worthwhile if they
are likely to operate in areas of long dry grass •
Avia tion Sa fety Digest 113 I 7
�Pilot contribution:
'You're not on your own'
On reading the article 'Pilot continued VFR flight
to follow the road leading ou t of this township but
into adverse weather .. . ' in Aviation Safety Digest shortly afterwards had to alter my heading almost
111I1980 I was again reminded of my belief that
60 degrees to track around the edge of a large Cb .
a great number of weather-related accidents occur When I turned back to regain track I could not
not only because the pilots continue flight into
find the road. It was then that I wondered briefly
conditions with which they cannot cope, but also
whether the small town was in fact Banana. I
because they are un willing to call for assistance
considered returning to Theodore but the Cb now
when they first experience diffic ulties. The article
blocked that route whereas the weather ahead was
also reminded me very muc h of circumstances in
much clearer.
which I found m yself several years ago on a flight
I now took stock of the situation. As I saw it
from Canberra to Rockh ampton in a Cherokee
there was no way I could get back to Theodore
Arrow.
safely. My ADF was temporarily useless as I was
T h e weather was perfect as I departed Canberra still about 60 miles from Rockhampton and the
but the forecast suggested that I would strike
instrument was pointing straight back at the Cb
increasing cloud as I proceeded northward, and
behind me anyway. I reasoned that. if I maintained
this proved to be the case. However, the first
my present heading I must eventually pass over
portion of the tri p , Canberra to Moree, was
either the Burnett Highway or the railway line
routine.
into Mount Morgan. Furthermore, I though t that
After refuelling an d having lunch in Moree I
as I got closer to Rockhampton and fur ther from
departed in ligh t drizzle. I had planned to cruise
the Cb I could get a bearing on RK NDB.
at the appropriate quad rantal levels of 5000, 6500
Nevertheless the fact was that I was uncertain of
and then 7000 feet, but it soon became obvious
my position and not even sure now whether the
tha t I would not maintain VMC at those levels so
town I had passed was Banana or nearby Moura.
I decided to stay at 500 to 1000 feet above terrain, I was also acutely aware of several articles I had
keeping the highway in sight. At this point I might read in Aviation Safety Digest about pilots
mention that I have held a Class Four Instrument
pressing on in bad weather and crashing, often
Rating for several years and have flown a
giving ATC or Flight Service no indication that
considerable number of hours on dark nights over
th ey were in an y difficul ty. In at least one account
m ost areas of Australia as far afield as Perth,
it appeared that h ad the pilot told Flight Service
Darwin and A lice Springs. It was, therefore ,
of his trouble he could have been given a radar
very tempting to climb above lowest safe altitude
vector to safety. Another article I recalled was
and n avigate from NDB to NDB. But I resisted
entitled 'You're not on your own' (Aviation Saf ety
that temptation even though I thought a t the time Digest No. 85). Recalling the advice in those
that rem aining visual at a low a ltitude made the
articles I swallowed my pride and informed
flight more arduous. T he wisdom of this decision
Rockh ampton Flig ht Service that I was unsure of
became increasingly obvious later and made me
my position and not certain that the town I had
more aware than ever that Class Four Instrument
passed was actually Banana. They asked me
rated p ilots must remain in VMC at all times.
whether I was still visual, to which I replied in the
I h ad no d ifficu lty following the Newell and
affirm ative, and they then suggested that I return
Leichardt Highways past Moonie, Miles and
to Theodore . I pointed out that I could not do
Taroom to Theodore.. However, soon after leaving
th at sa.fely.
Theodore I committed the error of judgement that
T he events that followed were quite an eyeled to m y becoming uncerta in of m y position later.
opener to me. Not only did Rockhampton provide
At this point the highway swung considerably to
prompt assistance, but almost immediately two
the left of track. Since the direct track to my next
other pilots who were familiar with the region
reporting point, Banana , was only 3 1 miles, and
began to give me useful information. I soon
for 10 miles of th a t the highway would be in sight, sighted the highway and railway line , and with the
I argued that I would only have to mainta in my
help of Flight Service and the two pilots I was able
present heading for 21 miles to arrive very close to
to make a positive identification of the township of
Banana at m y fligh t p lan ETA. However, my
Wura . Shortly afterwards I saw a river with much
plans soon began to go astray as I ran into isolated brilliant green effluent, suggesting that I was
heavy showers which caused me to a lter heading
nearing Mou nt Morgan. After being requested to
several times to maintain visu al flight.
hold for a short tim e over Mou nt Morgan I was
Neverth eless, shortly after the time a t which I
given a clearance to track direct to Rockhampton.
should have passed three miles abeam of Banana
I learned several valuable lessons from that trip.
I saw a small towmhip five miles to the port side
Firstly, no matter how confident you may be of
and gave my Banana position report. I continued
your ability to fly on instruments, don't fl y in I MC
8 I Aviation Safety Digest 113
unless you are appropriately qualified and your
aircraft is equipped for IFR flight. I am sure that
(quite apart from the illegality of it) had I entered
cloud I would have ended up in one of the Cb
surrounding Rockhampton at the time .
Secondly, with hindsight I can now see that I
should have kept the highway in sight, even though
it meant a considerable diversion from track.
Thirdly, don't be too proud to ask for help,
even if you are reasonably certain you could make
it eventually. The assistance I received not only
enabled me to determine my position quite rapidly
but also helped me to concentrate on a successful
conclusion to the flight , relieved of much of the
anxiety generated by the situation I had allowed
to develop. I might add that the assistance was
provided at a time when Flight Service and A TC
were handling a very heavy workload . I arrived in
the Rockhampton area at the peak of activity
associated with a large military exercise. When I
saw the frenzied activity taking place at the
airport - helicopters taking off and landing,
formations of aircraft in the circuit, and Harriers
dar ting in and out an d hovering over the runway
- I wondered how they even had time to
acknowledge my calls, let alone find time to help
out. Despite all of this I received personalised
attention of a most helpful and courteous nature.
I could not have been given better attention had I
been the only aircraft in the vicinity. So in future
remember as I shall, 'You 're not on your own'!
Editor's nete
The Digest article referred to b y the pilot, 'You're
not on your own', contained reference to a letter
the then Director 1.eneral of Civil Aviation sent to
all pilots in 1972. The purpose of that letter was
to encourage pilots to make full use of the facilities
available to them, especially if they ever four'.!
themselves in a critical operational situation. To
lend weight to that encouragement he stated that
pilots who did request assistance from airways
operations units in such circumstances would be
immune from any resulting disciplinary action.
More recently the Secretary to the Department of
Transport re-affirmed that policy in his editorial
message in Digest 100, in which he stated: 'I will
not impose any punitive measure upon any pilot
who, because of navigational or other difficulties
has need to request assistance from airways
operations units' .
An examination of incident reports suggests that
many pilots are still reluctant to use this facility.
Whether this is through a lingering distrust of the
system, ignorance of the help that is available or
failure to recognise a developing problem until too
late is not clear. Perhaps each of these and other
factors may apply in varying degrees. While
Airways Operations Officers are alert to the signs
of a developing problem and have many times
recognised when a pilot was experiencing
difficulties and offered assistance, they are not
clairvoyant. All the help possible is there for the
asking, but it is up to you to take the initiative •
ILS glide-slope pointer stuck
The aircraft was established on the localiser for an
I LS approach, but the glide-slope pointer was not
visible. T h e pilot , wh o was undergoing an initial
instrument rating test, assumed from the absence
of an OFF flag that the instrument was
function ing correctly and that he had flown
through the glide-path. He set up a high rate of
descent to regain it, but when the pointer did no t
appear as expected h e abandoned the approa~h.
At touch down after an NDB approach the pomter
appeared from th e top of the instrument, where it
had evidently b een stuck. The instructor
commented th at with n o FAIL flag showing he
would have expected th at the pointer should be
visible an d expressed concern th at such a failure
could induce a pilot to increase rate of descent
such as to risk a collision with obstacles.
The glide-slope pointer on the ILS equipment
involved is a conv~ntion al moving coil type as used
on many types of indicators. These do stick
occasionally, but it is not practicable to include
this failure mode in the fl ag monitoring circuit. It
is important that pilots cross-monitor with a
second g lide-slope display or, if there is only one
instrument , correlate with other navigational aids.
Remember also that approach ch arts show the
correct glide slope altitude at the outer loca tors
and m a rker beacons and include an altitude/ DME
distance chart for verification of glide slope
indications•
(Courl<'SY CAA Ge11eral '1viation Safety ln./iirmation)
,._
Aviation Safety Digest 113 I 9
�Fuel tank vents
When the hangar flying sessions get around to the 'There I was .. . ' situations, fuel tank vents are
unlikely to generate even a passing reference. However, a malfunction of these seemingly
innocuous systems can get a pilot's attention as few others can.
CROSSFLOW
Tank vents have three main functions: to prevent
a lowering of pressure in the tank by allowing air
to enter as fuel is consumed; to prevent a buildup of pressure in the tank with increases in
temperature, and to provide a small positive
pressure over the fuel to ensure a positive flow to
the engine in flight. Failure of the vents to do
their job can result in fuel starvation, fuel tank
collapse (which becomes really exciting if the tank
is of 'wet wing' construction) or, in the case of
excessive tank pressurisation, tank rupture and
wing damage.
In a recent incident the pilot of a Bonanza was
surprised when fuel pressure fell suddenly at
about 2000 feet during climb after take-off. He
had monitored fuel flow carefully during the
previous stage of the flight and had calculated
from published data and indicated fuel flow that
the tank should have contained 40 litres of fuel.
This belief was supported by the fuel contents
indicator; however, post-flight inspection revealed
that the tank was empty.
Investigation established that the tank vent,
which protrudes from the b ottom of the wing, had
been bent rearwards and, in flight , was creating a
negative vent pressure in the tank. The result was
a collapsed fuel cell and the loss of some 40 litres
of fuel through the vent. The fuel contents
indication was erroneous because float arm
movement was restricted by a crease which had
formed in the bottom of the cell as it collapsed.
The particular vent on the Bonanza is a six
millimetre diameter tube which protrudes from
the lower su rface of the wing behind and inboard
of the main landing gear. According to the Beech
A36 shop manual it should protrude at least 45
millimetres below the wing surface and be canted
10 degrees forward of perpendicular to the skin.
The manual also warns that any other
configuration may create a negative vent pressure
which will pull air and fuel from the tank.
Most pilot's handbooks contain only sparse
detail of what the-pre-flight inspection of tank
vents should include. In general, the pre-flight
inspection should include a check for obstructions
and a look at the condition and configuration of
the vent. In the absence of any information on
the correct configuration a comparison with other
vents may be useful in detecting abnormalities.
But as a general comment any configuration that
might create a negative pressure in the vent
system in flight should be treated with suspicion
and be checked by a qualified person.
*
10 I Aviation Safety Digest 113
In an overseas incident a Merlin III was cruising
at FL240 on an overwater flight when a passenger
pointed out to the pilot that the top of the right
wing was taking on a ribbed app earance. Within
another 15 or so minutes it developed a
pronounced 'collapse inwards' appearance and
the pilot concluded that there was a partial
vacuum in the wing. He diagnosed a fuel tank
vent problem and then reasoned that he could
relieve the depression by opening the cross- flow
valve - which he did. An immediate transfer of
fuel from left to right corrected the ribbing, but
the resulting fuel imbalance was near the
prescribed limit for landing and was increasing.
With the valve closed again the ribbing soon
reappeared, so the pilot elected to leave it open.
He considered several courses of action to
alleviate the problem but finally decided that the
best option was to attempt a landing at higher
than normal speed and as soon as possible ,
accepting the excessive imbalance - which
increased rapidly during descent as increasing
atmospheric pressure forced more fuel into the
already heavy tank.
The fuel tanks in the Merlin III are of 'wet
wing' construction and each is vented by a single
vent. In addition , there is a vent balance line
which vents one wing from the other in the evenl
of a blockage. However, the balance line does not
run directly into the fuel tank, but joins the
primary ven t line at a junction about 50
millimetres from the tank. As Murphy's Law
predicts , the hornet which had built its nest in
the vent built it between the junction and the
tank. As a result there was no venting to the tank
at all.
This incident not only confirms Murphy's Law
yet again , but also illustrates that insects wi ll not
always build where their nests can be seen. An
answer to this problem is to deny them entry either by installing fixed screens if the vent d esign
and configuration permit, or by fitting
appropriately designed covers whenever the
aircraft is parked.
D RA I N ~
FUEL CE LL VENT
AIR SCOOP
FUEL VENT
INTERCO NNECTING
LINE
POSITION OF
HORNET S NEST
;
·" '
*
While the two incidents described in this article
relate to ~pecific aircraft types, the points
concerning pre-flight inspection of the fuel vent
system and protection against entry of foreign
objects have universal application. Furthermore,
pilots must have not only a good knowledge of the
vent configuration of all the aircraft they fly, but
also a thorough understanding of the whole fuel
system so that the causes of problems can be
quickly and accurately diagnosed and appropriate
remedial action taken . Inappropriate action taken
through either a lack of understanding of the
system or an incorrect diagnosis may well
aggravate an already critical situation •
Typ ical light aircraft fuel vents
Aviation Safety Digest 113 I 11
�Inadequate mainte.nance leads to
gear-up landing
...
Objects ejected from aircraft during
flight in turbulence
~·-~
Unab!e to extend the left main landing gear on arrival at his <i~s tination, the pilot of an Aero
Commander 5005 elected to retract the extended wheels and execute a gear-up landing. The
aircraft suffered only minor damage in the landing and there were no injuries.
The landing gear had retracted normally after
take-off, and the flight was conducted in smooth
conditions without incident. On arrival at his
destination the pilot selected gear down on the
downwind leg of the circuit and obtained down
and locked indications for the right main and nose
gear, but the left main extended only about 300
millimetres and then stopped. The pilot tried
several times to free the jammed gear but was
unsuccessful. H ydraulic pressure was normal
throughout. Realising that a gear-up landing was
becoming a distinct possibility he elected to divert
to a major airport where better emergency services
and maintenance facilities were available.
The pilot succeeded in retracting the left main
gear by the application of negative 'g', but on
arrival at the diversion airport his attempts to
extend it were again unsuccessful. The left main
gear again extended only partially and jammed.
Repetition of the emergency extension procedures
and the application of both positive and negative
'g' failed to change its position. On A TC and
Company advice the pilot then diverted to a
nearby general aviation airport where em ergency
services had been alerted.
After briefing his passengers on emergency
procedures the pilot started his landing approach
to the grassed flight strip beside the runway. He
used full flap , aiming to touch down at low speed
but without stalling on . T he aircraft touched
down smoothly , 300 metres in from the threshold
of the runway and skidded 175 m etres, suffering
only minor skin abrasion to the underside of the
fuselage . The occupants vacated the aircraft
without assistance .
12 I Avia tion Safe ty Diges t 113
Initial investigation revealed that two bushes
which accommodate the landing gear torque link
had failed, interfering with the 90 degree rota tion
of the inner strut during extension and retraction.
However , the failure of these bushings alone
should not have prevented gear extension. Further
investigation revealed tha t th e upper and lower
needle bearings in which the inner strut rotates
had partially seized. They showed evidence of
moisture ingress, severe corrosion and lack of
grease. This had p revented strut rota tion a n d, in
turn , gear extension beyond the partially extended
position shown in the photograph.
In 1978 an Airworthiness Advisory Circular (No.
104) was issued to draw operators' attention to the
importance of regular lubrication of landing gear
systems. Furthermore, the manufacturer
recommends a 3000 hour overhaul period for
landing gear components in this aircraft. The
relevant components h ad, in this case, been in
service for over 11 OOO hours and there was no
evidence in the aircraft log b ook to indicate tha t
any such overhaul had been carried out.
While recommendations of this type are not of a
mandatory nature they are certainly not made
lightly. Rather, they are made on the basis of
service experience over a wide range of operating
conditions. Individual operators may see fit to var y
such recommended servicing periods in the lig ht of
their own experience, but they should recog nise
the possible implications of unduly large
extensions •
The aircraft, a Cessna l 72M, was on a VFR flight
below 5000 feet. The area forecast for the pe riod
of the flight predicted a south-easterly wind at 15
knots with visibility 40 kilometres and light
turbulence . However, 25 minutes after take-off the
pilot reported to Flight Service that he was
experiencing severe turb ulence . Nine minutes later
he fu r ther advised that the rear window of the
aircraft had been broken when a 4 .5 litre plastic
container fu ll of water was ejected du ring
turb ulence, and that he was returning with the
ruptured container wrapped around the leading
edge of the horizontal stabilizer. Shortly afterwards
the container fell away and the aircraf t landed
withou t further incident.
After landing the pilot discovered that a
magneto whic h he was carrying in the cargo
compartment behind the rear seat had also been
ejected. Neither th e magneto nor the container
had been restrained .
Fort un ately the occurrence did not cause injury
to a n yo ne in th e aircraft or on the ground, and
the aircraft suffered only m inor damage. Consider,
though, the potential for disaster. H a d th e
magneto struck the pilot, or had it damaged
the tailplane a fter being ejected the result could
well have been catastrophic. Similarly, it was
indeed fortunate that the occurrence did not take
place over a populated area.
While a m agneto may not be the most comm on
of articles carried as cargo, other potentially lethal
missiles ( tie-down stakes, tool boxes etc .) are often
carried. Furthermore, an object need not be heavy
or large to cause a problem. An y unrestrained
object can create a distraction if it is being tossed
around in the cabin and may pose more serious
problems if it comes into contact with controls or
switches. To be safe tie those loose articles down!
The pilot involved in this occurrence has since
purchased a cargo restraint net for use in his
aircraft •
Report those incidents
Seven p eo ple were killed and two seriously injured
in an overseas accident last year when a commuter
aircraft crashed during a Localiser/ DME approach
in b ad weather. The aircraft hit the top of a hill on
the approach path 4 .5 miles short of the runway,
and 854 feet below the published minimum altitude
at that point of the approach . T he investigation
concluded tha t t he pilot had made a premature
descent to MDA based on distance information
d isplayed from a DME sta tion located at the
Initial Approach Fix, approximately 4.5 miles
from th e runway , instead of the D ME associated
with the published procedure , co-located with the
localiser n ear t he runway threshold .
The factors involved a complex interaction of
aircraft instrumentati on characteristics, approach
chart p resentation, limited planning time for the
approach and prob ab le distractions at a critical
poinL of Lhe approach . H owever, these a re not
relevant to the point of this article.
T he moral of this accident surfaced during the
investigation, when several p ilots contacted the
investigation team to relate incidents in which they
had made procedu ral errors on this same
approach - errors which in bad weather would
h ave resu lted in their fl ying into the same hill. All
had descended on the wrong DME. Non e
submitted an incident report . Each was
embarrassed about making such a mistake and
believed his was an isolated incident.
Tragically this hazard was brought to everyone's
attention one accident too la te . T he moral is
obvious: report those incidents! •
Aviation Safety Digest 113 1 13
�Pre-flight pointers
Each year the accident and incident reports
contain a disturbing number of occurrences in
which inadequate pre-flight preparation and
inspection of the aircraft feature as sign ificant
factors. The two most common deficiencies
observed are failure to ensure that sufficient fuel is
carried for the intended flight and failure to
calculate and apply performance data in
operations from ALAs. These wi ll be featured in
separate articles in a future Digest. Some examples
of other checks and pre-flight actions that have
been overlooked in the past are illustrated in the
following brief accounts of a few selected accidents.
In addition, the articles on pages 10 and 13 of this
Digest are relevant.
*
The pilot of a Beech A36 conducted only a
cursory pre-flight inspection prior to starting the
engine for a short travel flight. He had flown the
aircraft earlier that day and said that he h ad
carried out a full daily inspection before that
flight.
After start-up he taxied for an intersection
departure and completed the take-off checks while
the engine temperatures came up . He then entered
the runway after checking for traffic and applied
full power for take-off. At about 75 knots he
attempted to rotate the aircraft to lift off, but the
control column would not move. At this stage
sufficient runway remained for the pilot to
abandon the take-off, but instead he continued
and attempted to rota te the aircraft with elevator
trim.
This, however, had the opposite effect and the
aircraft 'wheel-harrowed' off the end of the runway
under full power. The aircraft was destroyed and
the pilot suffered head and chest injuries through
contact with the control wheel and instrument
panel during the ensuing ride through the rough .
He h ad not fastened his shoulder harness. His
injuries were, however, slight compared to what
they might h ave been: a h eavy generator unit he
was carrying unrestrained on the rear floor was
ejected through the side cargo door of the aircraft
and not forward.
Investigation of this accident revealed that the
pilot had not removed the control lock before
flight.
*
The engine of a Cessna 182 failed soon after takeoff and the pilot was faced with a forced landing
on unsuitable terrain from about 150 feet. He
attempted to stretch the glide and reach a
clearing, but the aircraft stalled and impacted in
a nose- down attitude in a sparsely wooded area.
The ensuing slide was short: the aircraft came to
rest inverted only 30 metres from the impact
point. Fortunately none of the three occupants
was injured.
The aircraft had been refuelled from drums the
previous day. On completion of that fuelling the
pilot took fuel samples from the wing tanks to
14 I Aviation Safety Digest 11 3
Zealand Civil Aviation Magazine Flight Safety,
from which ideas for the format and many of the
pre-flight pointers were taken.
Chief Flying Instructor for his advice and
supervision of its preparation.
Acknowledgement is also made to the New
check for water. Next morning during his daily
inspection he took fuel from the fuel strainer drain
but did not take any more from the wing tank
drains.
During the accident investigation almost half a
litre of water was drained fro m the fuel supply
line, filter bowl and carburettor. How the water
got into the tanks could not be determined , but
two significant points emerged from the accident.
Firstly, a fuel drain from all points is essential
before flight , particularly after a n aircraft has sat
overnight. Secondly, the m ethod used to extract
the fuel from the drums would have ensured that
any water in the drum was pumped into the
aircraft tanks. The drum had been tilted to allow
water to drain to the lowest point - but the
pump was then inserted at that point and fuel
drawn from the low side.
*
3
•
'
In a similar accident the pilot of a Fletcher ran his
aircraft through some fences during a forced
landing when the engine failed soon after take-off.
In this case the pilot had taken fuel from the wing
tank drains during his daily inspection but not
from the fuel strainer drain. Again , a substantial
quantity of water was drained from the filter bowl
during the investigation.
2
*
Apart from the requirements prescribed b y ANOs
20.2 and 100.5.1 there are no hard and fast rules
governing the extent to which a light aircraft
should be pre-flighted , and opinions differ
considerably from pilot to pilot. However,
experienced pilots will agree that there are certain
checks which should n ever be omitted under any
circumstances, others which should be done before
the first flight of the day and yet others which
should follow any extended p eriod during which
the aircraft is not flown . The ch ecks shown here
are offered as a general guide only. Pilots should
be familiar with the ANO requirements and should
also refer to the operating handbook for detailed
inspection requirements for each aircraft they fl y.
T he pre-flight inspection is a vital pre-requisite
to safe flight and, as such, is deserving of the
pilot's utmost diligence and undivided attention .
Never be in a hurry during the pre-flight and
don' t try to conduct it when pre-occupied with
other tasks or problems. A pilot with other things
on his mind may well go through all the motions
of the pre-flight, but he will often 'look without
seeing'.
As a final reminder, don't forget to pre-flight
the pilot. Ensure that you are physically fit and
mentally prepared for the flig ht before sta rting
any other preparation. A pilot who flies an aircraft
when he is unwell or ill -prepared is a h azard to
himself, his passengers and other aircraft.
We wish to extend our a ppreciation to the
Royal Victorian Aero Club for the assistance given
in assembling this article a nd, in particular, to the
l. Check documentation: maintenance release,
flight manual, and flight authorisation (if
applicable) and then make any required
perfonnance or weight and balance calculations.
2. While approaching th e aircraft observe chocks,
ropes, external locks, pilot covers etc. to be
removed appropriately. Note the position of the
aircraft relative to other aircraft, hangars and
other obstacles, and if confined consider
manhandling it to a more open area before start.
Observe that the aircraft sits level (flat struts,
tyres, landing gear damage).
3. Check brakes parked, controls unlocked and
full and free movement in correct sense, switches
off, mixture idle cut-off, throttle closed, J uel on.
Master switch as required to configure the aircraft
for the pre-flight . Note Juel contents indication.
Che ck windshield condition and cleanliness. Check
cockpit cleanliness, dead paperwork, drink cans,
ashtrays etc. Check security of fire extinguisher,
Ji'rst aid kit etc. Check provision of sz'ck bags.
Inspect seat rails and check locking mechanism.
Check trims through Jull range and set to neutral.
Ensure all placards are secure and legible.
4. Check fuselage for ripples, sprung rivets and
stone damage. Check drainholes are free of
obstruction.
Aviation Sa fety Diges t 113 I 15
�5
8
-
6
10
12
-
9
ll
5,6, 7. Ch eck rear fuselage, ji"n and horizontal
stabihzer f or buckling, ripples, sprung rivets, stone
damage and cracks. Check rudder and elevator
hinges, act uating rods, mass balance integrity, and
full and free movement. Check trim tabs.
8. Check all communication and navigation aid
aerials and components for security.
9. L anding gear. Check condition of tyres: wear,
inflation, cuts, creep,· check brake pads and discs;
inspect hydraulic lines and unions for condition
and leaks; ensure retraction mechanism is free of
dirt and grime, insjJect condition of moving parts;
inspect attachment points for bucklz'ng or other
evidence of a heavy landing; check struts for
correct extension and fluid leaks. Ensure tow bar
is removed from nosewheel. O bviously, the things
to check here will vary widely with different types.
W ith retractable gear a thorough knowledge of
the system is essential.
16 I Aviation Safety Digest 113
10, 11. Check flap and aileron hinges, actuating
14
rods, mass balance integrity, full and free
movement . Check trim tab .
12. Check wing tips, strobes, navigation lights for
evidence of ground contact and hangar rash.
Check wz.n g tip fairings for cracks around
attachment fasteners .
13. Check wzng surfaces and leading edge for
evidence of birdstrike and overstressing. Look for
abnormal rippling between rivets on the upper
SU1face and around wing roots, strut junctions and
landing g ear attachment areas. Ensure that any
frost or ice on the wings z's removed before flight .
Check for J uel stains on lower surface and around
wing roots.
14. Check stall warning tab for free movement
and correct operatz"on. In some aircraft the master
swit ch may need to be on to check the light and
warning horn.
A viation Safety Digest 113 I 17
�15
17
19
16
18 !
20
15. Remove covers from pitot heads and check for
obstructions. Similar(y, check fuel vents and statir
vents. If checking j1itot heat wet your jl'nger first.
With no cooling airflow the pitot head can gel
very hot.
-
17. Another vital chech! Without oil yo ur engine
wouldn't last a minute. Check also condition of the
oil, tiny flakes of metal and water contamination.
Ensure filler cap is correctly secured and the access
panel is closed and fastened.
16. Fuel quantity - a vital check! But remeniber:
visual estimate is unreliable unless tanhs are full or
filled to a defined level (tabs etc); di/Jslick may be
inaccurate unless the aircraft is level; lime card
calculations are not always reliable; and gauges
may lack sensitivity and be inaccurat e. Therefore
cross check, and then if in doubt fill up anyway or
add enough fuel for the flight. Ensure caps are
correctly filled.
18. Check correct closing, fit and security of cowls
after cheching engine bay for: bird nests, cleaning
rags or other foreign niatter; cracked exhaust
systems and heater muffs; frayed ignition harness
or air ducting; security of engine control linkages;
and chafed oil orfuel lines. Fuel leaks may be
evidenced by staining and signs of washing on
cowls. Check security of all inspection panels.
•
21
22
19, 20. The oil cooler and induclz'on az'r filter must
be secure, clean and unobstructed. Landing lights
should be clean. Check propeller for tip damage,
leading edge nicks and cracks and spinner security.
Even ap/;arently minor nicks can lead to fatigue
crnching and blade failure, so ensure that they are
pro/Jerly dressed out by a qualified person. Pull
propeller through bachwards to check compression.
If all cylinders are not equal, have it checked. Do
not co1npression chech a hot engine.
23
21, 22. Contaminated fuel is deadly! Take samples
from all tank drains and the strainer drain. Check
for contamination by water or other foreign matter
(methods of checking for water contamination are
given in ANO 20.2) . Check grade of fuel by colour.
Ensure all drains are j1roperly closed and not
leaking. Do not return fuel to th e tanks - discard
it downwind clear of az'rcrajt, smokers etc.
23. Stow baggage, equzjmient, chocks etc., tie them
down securely and you are ready to go, with the
assurance that your aircraft is mechanically sound •
18 I Aviation Safety Digest 113
Aviation Safety Digest 113I19
�Complacency leads to navigation
error
Ask any 'old' pilot what his formula for aviation
longevity is, and one of his pieces of wisdom will
probably be to treat every piece of information
with a certain amount of scepticism until its
accuracy or authenticity can be verified. T hat is
a fundamental rule of safe flying which has
developed from experience over the years, but
one which is frequently overlooked. This article
relates to an incident that testifies to the
continuing validity of it.
About 50 minutes after take -off in a modern
turbo prop aircraft for a single-pilot IFR flight ,
the pilot recognised that all was not well with his
navigation a nd set about est ablishing his position
visually. Fortunately he was relatively familiar with
the area a nd the visual cues were prominent , for
h e found himself to be 195 ki lometres off track: a
track error of 46 degrees.
H ow did it ha ppen ? The pilo t had placed his
faith in the accuracy of his No. l compass system
and did not think to cross-check it with eith er the
standby compass or the N o.2 (co-pilot's) system.
Had he done so he wo uld h ave discovered tha t his
own compass was inaccurate.
After e ngi ne start , the pilot h ad set his compass
system heading bug to the runway heading and
taxied to the runway. On line -up , take-off and
departure th e compass appeared to the pilot to be
working correctly. After take-off he engaged the
auto-pilot , selected heading hold and intercepted
the outbound track wi th re ference to the
departure point NDB. He commented later that
the track a ppeared normal to him, but he did not
check it visually: the radio n avigation aids, ADF
and DME, were giving the indications he expected
to see.
Thirty minutes after departure the pilot
reported at his first reporting p oint , having
establish ed his position with reference to the
departure point NDB and DME. He was receiving
:in off-track VOR, but he did not use it, nor did
h e tune his No .2 ADF to other NDBs that we re in
r ange. After passing the reporting point the pilot
tuned and identified the next on -track N DB , but
the bearing indications led him to believe that his
ADF was not tracking correctly a t tha t time.
However, he was· unconcerned abo ut this beca use
of a history of ADF problems with that aircraft ,
and he continued to fl y his heading . Shortly
afterwards the VOR and DME 'dropped out' - at
about the exp ected time . Ho wever , when the ET A
for the n ext NDB was nearl y up , with the ADF
still not behaving correctly , the pilot started to fee l
some concern and decided to establish his position
visually. It was a fter he h ad done this that he
found that his No. l com pass was grossly in error.
Trouble-sh ooting revealed that the slaving system
had been inadvertently switched off and the
compass h ad for some time - probably since
departure - bee n operating as a free gyro with all
20 I Aviation Safety Digest 113
its inherent drift and precessions. The auto-pilot
dutifully followed this drift by following- the
heading bug.
How could an experien ced , instrunient rated ,
professional pilot a llow a simple switc hing e rror lo
degenerate over nea rl y an ho ur into a navigation
error of suc h proportions? Firstly, h e had flown
the route many times , applying the same
navigation technique wit hout previous difficult y;
he had flo wn the a ircraft on the preceding flight
and experienced no n avigation d iffic ul ties, and the
weather was good. Complacency, then , probably
p layed a big p a rt. But let us look closely al some
of the other factors.
• The company operations manual did no t
prescribe any specific checks of the compass
slaving system or switch selections. Pilots were
expected to monitor it a long wit h ' their normal
compass checks.
• T h e slaving selector switch is unguarded a nd
positioned close to both the park brake ha ndle
a nd assigned a ltitude indicator where it can t>asily
be operated inadvertently.
• T he compass slavi ng selector and indicator arc
not visible to the pilot from his normal seated
position.
• Continuing problems with the ADF over a long
period had led th e pilot into accept ing the
a pparent lack of ADF performance as norma l,
when it should have indicated to him that
something was ami ss.
• Some of the visual c ues availa ble to the pilot on
the track flown were , by coincidence , simil ar to
those on the correct track.
T his incident illustrates the dangers of
complacency and the importance not on ly of
checking information against another source , but
also of making use of all availa ble information. It
also illustrates the dange r of accepting 'negative'
information. The loss of VOR and DME signals at
about the ex p ected time was , in fact , meaningless ,
but it reinforced the pilot's belief th at a ll was well.
He also acce pted as normal , for a considerable
amount of time, the lac k of ADF bearing
information when he should h ave been well inside
the rated coverage of the NDB. Incidenta ll y, the
ADF problem persisted because the pilots had
stopped compl a ining a bout it. This led
management to believe that the problem had been
corrected.
Fortunately, th e terrain over which this incident
occu rred was not m ountainous and terrain
cl earan ce on the track flown did not pose any
threat. Fortune then smiled upon the pilot again ,
in that a diversion aerodrome with fuel available
was within range when he discovered his position .
But the question that will never be a nswered
is . . . 'what if there h ad been solid unde rcast in the
a rea, with no chance of a visual fix, and o ut of
range of a ll nav aids'? •
Thunderstorms
All pilots have heard the warning, 'Don't land or take off in the face of an approaching
thunderstorm'. But, as one ag. pilot recently learned, it can be equally hazardous to take off away
from an approaching storm!
Super-spreading operations h ad been going on a ll
day without incident. But the day was hot, and
during the afLernoon h eavy cloud and
thunderstorms bega n to build up in the area.
After spreading his 76th load, the pi lot landed
into the lig ht northerly wind as h e had done all
day and re-loaded. But when he taxied for take off he observed that in the two to three minutes
he was on th e gro und the wind had c hanged to a
southerly and increased in strength. At the time
two thunderstorms were centred about 20
kilometres to the north and east. The take-off was
made into the south (away from the storms) a nd
was norm a l; however, soon a fter turning left
towards the spreading area , the a ircraft briefl y
entered light rain and modera te turbulence , and
then entered a rapid descent. The pilot dumped
the load and applied maximum power - but in
vain; he was unable to prevent a collision with the
ground. Fortunately the aircraft was in a level
attitude at impact and the area was fl a t and
relatively unobstructed . T he pilot , who was not
injured, was able to stop the a ircraft without it
sustaining any more damage.
Within minutes of the occurren ce the wind
swung around to the east and became very strong
for a fe w minutes before heavy ra in started to fa ll .
A ma ture thunderstorm cell is ch aracterised by
powerful updra ughts and downdra ugh ts which are
formed when cold dense a ir cooled at altitude
displaces the warmer less dense air n ear the
surface. The downdraughts are often accom panied
by h eavy rain , and sometimes hail , and can reach
vertical speeds exceeding 6000 feet pe r minute.
Furt hermore, their effect can be displaced several
kilometres from the centre of the storm ; the
descending a ir when it meets the earth's surface
creates an outflow of air in a ll directions beneath
the cell. An aircraft operating in this a rea at low
level may encounter these rapidly ch a nging
horizontal a nd vertical winds and , in the worst
case, sufficient corrective action may be beyond
the capabilities of the aircraft •
*
Aviation Safety Digest 113 1 21
�_Spark plug fouling
I
:'6.
Largely because of falling demand and rising costs,
fuel companies have found it less and less attractive
to continue marketing A VGAS 80 which , in
Australia, began to disappear during 1976 and is
now largely unobtainable. Consequently, operators
have been forced to turn to AVGAS 100 or the
replacement fuel A VGAS lOOLL. For various
reasons, however, low-lead fuel is not yet widely
used and m any engines are running on A VGAS
100, a fuel containing up to six times as much lead
as that for which the engines are designed. This
h as led to several problems, the most evident to the
p ilot being spark plug fouling with associated loss
of power and rough running.
While an abrupt engine failure from spark plug
fouling is unlikely, the potential for an accident is
nevertheless there whenever normal engine
operation is impaired. The records contain many
reports of aircraft failing to climb away after takeoff or being unable to maintain h eight in the
circuit. Fortunately most of the incidents have
occurred near aerodromes and safe landings have
been possible, though many pilot's adrenalin
output h as received the stimulus of a rough
running engine over inhospitable terrain , and
some aircraft have been damaged d u ring forced or
precautionary" landings away from aerodromes.
The problem of lead fouling arises when low
engine operating temperatures coupled with a rich
mixture prevent the comple te vaporisation of the
tetraethyl lead (TEL) in aviation fuel. Under these
conditions lead deposits can form in the
combustion chamber and may a dhere to the spark
plug electrodes, causing misfiring.
By establishing and maintaining prope r engine
operating temperatures the problem is largely
eliminated . Aviation fuel contains a scavenging
agent which h elps prevent the formation of lead
deposits by keeping the TEL va porised, allowing it
to pass out through the exhaust system. But this
agent is effective only when the sp ark plug nose
core temperature is kept at about 430 degrees
Celsius or higher. Operating techniques that resul t
in low engine temperatures may not a llow the
p lugs to reach that temperature.
Lycoming Service Letter No. Ll92A, March
1981 , addresses the subject in respect of Lycoming
engines and recommends some operating
techniques which can reduce or eliminate the
problem . These recommendations also a pply in
principle to other makes of piston engine and are
n ot restricted to those designed to use 80 octane
fuel , but operators should ensure that
m anufacturers' instructions do not prescribe
procedures or limitations that would p rohibit their
22 I Aviation Safety Digest 113
adoption. The recommended tec hniques are
contained in the fo llow ing advice:
• Ensure by consulting spark plug recommendation
charts that correct plugs are installed. In the event
of a continuing or severe problem it might be
advantegous to experiment with slightly 'hotter' or
'colder' plugs from the range approved for use in
the engine.
• When changing spark p lugs do n ot simply
replace with plugs of the sam e part number incorrect plugs may have been installed p reviously.
• Do not continue to operate an engine t ha t
exhibits symptoms of a n over-rich idle m ixt ure
such as incorrect or unstable idle speed , black
smoke from the exhaust, or a te nde ncy to
accelerate excessively when idle-cut-off is selected .
Have the mi xture adjusted .
• When temperatures have risen sufficiently after
a flooded start , slowly run the engine to about
1800 RPM for a short time to melt and scavenge
a ny lead deposits that may have formed.
• Avoid unnecessary closed-throttle operation on
the ground. A minimum engine speed of about
1200 RPM is required to keep the spark plug nose
core temperat ure high enough to allow the lead
scavenging agent to do its job. But when taxying
use whatever powe r is required to mainta in the
d esired speed . Do not taxi with power against
brakes - this leads to brake overheati ng and
premature wear. Following prolonged taxying,
check for plug fouling before take-off by
conducting another switch check.
• Lean the m ixture when cruising
regardless of
al ti tude - but observe any limitations on leaning
at high power settings. Re-lean after the
application or removal of carburettor heat or
alternate air .
• Schedule cross-coun try fligh ts for training
aircraft whenever possible . Continuous rich
mixture , low-power operations associated v:it~1
circuit work may allow lead deposits to
accumulate.:
• Keep cylinder head temperatures near the
middle of th e normal operating range
around
190 degrees Celsius. Many people believe tha t
engine life is prolonged by operating with cylinder
head temperatures as low as possible. This is a
fa ll acy and the practice leads to spark plug fouling
a nd likely accelerated engine wear.
• In winter use oil cooler baffles to keep oil
temperatu re up.
• Avoid fast , low-power descents. Plan a d escent
profile that allows the use of sufficient power to
keep engine temperatures up.
• Before shut-down run the engine up to 1800
RPM for 15 to 20 seconds, then reduce to 1200
RPM and shut it down with the mixture control.
• Swap to p and bottom plugs every 25 to 50 hours
- lop plugs sca venge better than bottom.
In some cases use of the primer may also
contribute lo spark p lug fou ling. A Cessna l 72B
operator in Queensland reported tha t the
unacceptable fo uling he experienced when forced
to use A VGAS 100 appears to h ave been
eliminated si nce he stopped using the engine
primer for starting. He found that under his
operating conditions he could obtain sa tisfactory
starting by 'pumping' the throttle once or twice
immedjately before engaging the starter. The
pr.imer was apparently injecting too much fuel
which was resulting in an over-rich mixture with
consequent fouling while th e engine was running
cold just after start. Operators in cooler climates
may find it necessary to make some use of the
primer, but over-priming should be avoided.
A number of advanced design spark plugs which
resist lead fouling are available. In one, the mouth
of the plug is so shaped as to provide maximum
temperature on the central insulator during the
firing stroke and maximum cooling during
induction . Another has an extended centre
electrode and insulator which allows the plug to
con tinue to fire even when substantial lead d eposits
have formed, while others use special electrode
materials which resist fouli ng. However, before
installing any new plug operators should check
that it has been approved for use in the particular
engine type .
.
The foregoing advice is directed principally at
preventing the formation of lead deposits. In many
cases though , adoption of the techniques described
will also remove deposits that have already
formed . And fo uling d etected on the ground can
often be cleared by a short period of operation at
about 1800 RPM with lean mixture. However,
caution should be exercised in following this
procedure because incorrect or prolon ged
execution can resu lt in excessively high cylinder
head temperat ures and detonation with consequent
engine damage. Furthermore , the indications of
lead fouling may also be symptomatic of more
serious proble ms and sho uld normally dictate
investigation by a qualified person before the
aircraft is flown •
Carbon monoxide enters aircraft cabin through defective door seal
Articles on the dangers of carbon monoxide
infiltration into aircraft and motor vehicle cabins
appear regularly in most avia tion and road safety
publications (see Aviation Safety Digest 109),
usually highlighting the need for proper
maintenance and inspection of exhaust and heater
systems. However, following a recent incident in
which the pilot suffered symptoms of carbon
monoxide poisoning, the gas was detected in the
cabin of a near-new Cessna 185F which was fitted
with a special purpose belly pack. Investigation
establish ed that the belly pack modified the
airflow under the aircraft, deflecting the exhaust
gas flow over th e bottom of the right door from
where the gases entered the cabin through a fa ulty
door seal. The door seal appeared from a visual
inspection to be in good condition and the leak
was found only when a stream of smoke was
directed at the b ottom front corner of the door.
Rectification of the defective seal eliminated the
gas entry problem.
This incident illustrates how a seemingly minor
defect can have potentially disastrous consequences,
and demonstrates that even a thorough visual
inspection can, in some circumstances, be
ineffective . Rigorous maintenance of door seals
and locking systems is clearly necessary, but as an
added precaution the carriage of carbon monoxide
detectors in light aircraft would seem to be wise .
Operators' and pilots' attention is again drawn to
the availability of simple 'spot' type detectors.
These are small plastic cards containing a disc of
c hemical which darkens when exposed to carbon
monoxide . They presently sell for less than two
dollars and, at that price, must surely be very
cheap insurance against the insidious effects of this
colourless, odourless and tasteless, but lethal gas •
Aviation Safety Digest 113 I 23
�Index to issues 1-112
Numbers refer to issues and pages. General articles are indicated in bold type. Other re ferences are
to C:tcc ident and inc ident reports.
Accident prevention 102-10
Aerobatics 8- 23 , 9-22 , 10- 17 , 27- 3 , 27-27, 28-1 2,
33-9 , 34-1 9, 40-4, 47- 5 , 75- 12, 76-12, 78-6,
81 - 10, 87-6, 92- 2, .102-19, 104-26
Aerodromes
Authorised landing areas 97-22 , 107-5
Government, licensed , ALA 107-5
licensed 41-24
outback 5-6
procedures 49- 13
Aerosol cans
danger of explosion 89-28
Agricultural flying 6-1 6, 6- 24 , 7- 22, 7-23, 7- 27,
8-5, 8- 25 , 8-27 ' 9- 2 1, 9- 23' 9- 24, 9- 25 , l 0 19 '
11 - 22, 11 - 26 , 12- 19, 12- 2 1' 12- 22, 13- 24, 13- 26,
15-27 , 18- 7, 20-18, 20- 25 , 21- 18 , 21 - 27, 24- 8,
28 - 14, 28-22, 28-24, 30- 7' 30-8, 31- 26, 3 1- 28,
33- 23, 36-18, 38-1 , 41-14, 42- 12, 44- 14, 48- 4,
50-14 , 56- 16 , 56-26 , 59 -1 6 , 59 - 25 62-19, 63-17 ,
67 - 3, 67-5, 70- 7, 70- 19 , 74-10 , 88-16 , 90- 6, 94- 26
Common Law 44-19
human markers 16-27
sulphur-dust fires 9-7
Agricultural strips 13-25, 13- 27 , 58-10 , 86-19 , 98-2,
98- 9 ' 104- 18
Aircraft security 102-16
Cockpit
c hecks 10-1 2, 16-19, 26-26, 34-6,
42- 26, 66- 12, 66- 18, 86-16, 96-1
design 1-5
lig hts 102- 18
liquids spil t in 6-5, 27-25
see also Preflig ht checks
ATC 8-7, 20-14, 27- 18, 34-1, 57-14, 77 - 17, 85-6
Autopilot 21-14, 70- 14, 90-26
Banner towing 39-17
Beach operations 107- 8
Birds
damage by 53 - 28
nests in aircraft 83-21, 99-28, 107-26, 112 - 12
strikes 2-9, 34- 24, 38-6, 41-11 , 49 5, 71 - 1, 87 - 27,
102-28, 104-12, 109-13
strike reporting 112-30
Blasting
danger to low-flying aircraft 81-28
Brakes 11 - 27, 45 - 18, 71-27 , 91- 28
excessive wear, dirt strips l ll-9
failure 85- 10 , 88-14
·
reverse thrust 31-7
Cables
inspections 107-15
splices 101 - 13
Carbon monoxide 23- 26, 45-16, 51 -1 3, 89-18, 109-3
Cargo
incorrect weight 103- 14
see also Dangerous cargo
Airmanship 48-14, 67-14, 78-28, 79-14, 102-4
Airsickness 90-13
see also Drugs and medication
52-14, 68-1, 73-24, 75 - 2, 77-17 , 99-14, 100-7 ,
100-23 , 100-30 , 101 - 17 , 101 - 19, 102-2 , 103-3
see also Sensor y illusions, Weather
Centre of gravity 7-26, 14-26, 25- 17 , 56 1, 86 - 12,
104- 8
Collision
mid·air 5-1 6, 7 24, 7 27, 11 13 , 20-6, 25 - 20 ,
27 18, 28- 4, 62-6, 74 18 , 75 -28 , 77-26, 98-5 ,
101 - 8, 103-27
on gro und 33-10
parachuting 69-14
with anim al 70 24, 10 l 24
with object 1-23, 3 30 , 5-24, 5- 25, 6 10, 6 16,
6- 17, 6-22, 6 25 , 6-27 , 8-5 , 8-8, 8-12, 8- 25, 9- 14,
9 22, 9- 23, 9- 26 , 10 19 , 10 22, 11 - 22 , 11-26 ,
12 19, 13 -25, 13 - 27 , 14 26 , 15-22, 15-28, 16-26 ,
17-13 , 17 2 1, 19 10 , 20- 18, 22 - 14, 22 15 , 23- 21 ,
3 1 24, 32- 6, 34-22 , 37 -1 6, 40- 3, 40- 24, 42 18 ,
42 26, 44 14, 45 10 , 48 1, 48-4, 53 - 2, 54-7 '
57-16, 57 -1 8, 58 - 1, 58 5, 58-10, 59-8, 61-1 ,
6 1- 20, 62-2, 64- 5 , 65 24, 67-16, 69 - 5 , 71 1,
76 19 , 79- 18 , 80-26 , 83 6, 83- 11 , 84 16 , 90-6,
90-10, 90- 16, 9 1 11 , 91-14, 92-27, 94- 26
with terrain 1-1 6, 7-22, 9 11, 9 25, 10 - 10, 10- 20 ,
13-12, 13 25, 13-26, 17-22, 18 4 , 18- 16, 19- 4,
19 11 , 20- 25 , 22 10, 23 - 12 , 23-24, 24 8, 24-13,
29 - 11 , 30- 11 , 33-23 , 35 - 5, 36- 16 , 42 - 12 , 42 - 13,
45 - 24, 48 18, 49 - 6, 50 2, !JO 16 , r) l - 9 , 53-7,
53- 12 , 54- 2, 54 18, 63 1, 63 9, 67 24 , 68- 20,
71 10 , 72- 1, 72-1 0, 74- 10 , 78- 1, 87-6 , 88 2, 93- 2 ,
94 6, 94 10, 94- 14, 95-6, 98- 20 , 98-24 , 103- 8,
105-26
with water 7- 8, 7-1 5, 20-16, 43 8 , 73 27 , 74- 8,
77 10, 79 2, 80 22, 85 - 2, 94-22
see also Ditching, Wire strikes
Comm unications 19-3, 19-15 , 32-1 , 35-8 , 38- 28 ,
40-26 , 47- 19, 47-27, 49- 13, 52-13 , 57 - 14
loss/ failure 103-30 , 109-18
see also Radio procedures
Channelised attention 103- 28, 107 - 19
Airspeed 26- 20, 59- 19
Airways operations 8-7, 85-6
see also ATC, Flight Service, Controlled airspace
Chocks 105-9
Compass
error 3 1-22 , 44- 20, 72 - 21
in terference 22-20 , 27- 26 , 28-23, 55- 20 , 69 - 22,
97-28
Alcohol 52-2, 52- 6, 63- 1, 77 - 20, 85- 2
Circuit procedures 97-14, 99-8 , 108- 25
Compl ace n cy 94-6
Altimeter 7-3, 13-12 , 14-18, 17-22 , 19-4 , 21-5 ,
23-4, 27-1 4, 45- 24, 48 - 18 , 65-1 4, 65- 23, 68-28 ,
74- 28, 78-1 , 80- 22 , 87-6 , 87-28, 94- 6
Cloud 3-25 , 5_-24, 6-27, 16-16 , 17-13, 18-28, 30-11 , 11 ,
39- 4, 39- 18, 42- 18, 52 - 14, 54- 7, 55 - 2, 55- 16 ,
57- 18 , 57- 27, 66- 4, 75-1 8, 75-27, 79-1 8, 80- 2,
85 -9 , 87 - 16, 89 - 8, 91-27, 94- 2, 96-14 , 98-2
collision with terrain 12- 15 , 14- 23, 16 -1 5, 18-20,
4 1- 2, 43 -1, 60-1 , 65 - 1, 73- 2. 73 - 8, 73-1 3, 73- 17,
73 - 27, 74- 1, 77- 10, 78- 21, 79- 2, 8 1- 2, 81 -6 ,
82 - 10 , 82- 19, 89- 2, 91- 16, 95 - 2
control loss 7- 26, 9- 14, 10- 16, 10- 22, 16- 14, 16 - 16 ,
16- 18 , 16- 25, 17- 18, 20- 10 , 21- 20, 28- 8, 34- 14,
37 - 1, 38- 25, 40- 20, 4 1- 8, 4 1- 16, 49- 1, 49 - 16,
Control/s
crossed 20-5, 59- 27
difficult 46 11 , 52- 14 , 60-16, 61 - 25 ,
disconnected 100- 15, 112 - 9, 112-20
failure 23-7, 23- 14 , 27- 12, 27-22, 33- 16, 51 - 1,
54-1 4, 65-26 , 11 2- 22
interference 6- 23, 29 1, 34- 10, 38-26, 54- 2, 61 - 6,
62- 18, 68- 24, 80- 6, 89 - 13, 92- 28, 99 27, 100 - 4,
101 - 7, 102 - 18 , 103- 28, 104- 17, 104- 25
lock left o n 62- 14 , 68- 27 , 90- 16 , 110- 2 1
loss of 2- 14, 3- 12, 5- 11 , 6 8, 6- 12, 7 26, 8- 14,
Checklist 99- 13, 109-6
Anti-collision lights 105- 25
Aquaplaning 29-16, 37- 16 , 39-1 , 53-14
Asymmetric flight 4- 1, 6- 17, 13- 11 , 17- 7, 19- 8,
21- 24, 23- 10 , 26- 6, 27- 6 , 31 - 8, 36- 16, 78-1 1,
90-20, 93- 2
24/Avia tion Safety Diges t 113
8-17 , 8- 21, 9- 14, 9- 20, 10- 12, 10-16, 10-22,
11 16, 11 - 21, 13- 21 , 15-7 , 16- 14, 16-16, 16-18 ,
16- 25, 17 7, 17 - 18, 17-19, 18-19, 18-30, 19-24,
20-8 , 20- 10, 20- 12, 21 - 20, 21 - 24, 22- 8, 22- 24,
23-8 , 25- 17' 26- 24, 28-8, 30- 8, 30- 10, 30- 17'
31-8, 32- 10, 33 - 24, 34- 14, 35- 18, 37-1 , 38-25,
40- 6, 40- 20 , 41 - 8, 41 - 16, 43-20, 45-18, 46 - 12, ~
49- 1, 49 16, 43 - 20, 45 - 18, 46-12, 49- 1, 49- 16,
51 - 1, 52-2, 52-6, 52- 17, 53- 2, 53-7, 54- 25 , 56-5 ,
57- 1, 58- 16, 63-5, 68-1, 73- 24, 74- 10, 75-8, 76- 8,
77-17 , 80- 6, 84- 6, 86- 8, 87- 8 , 87- 20 , 88- 9 , 91-3, .
104- 8, 106- 30 , 107- 25
use of wrong 8-12, 8-13, 12- 7 , 62-28, 70- 16 , 94- 27
Controlled airspace 28- 3 , 3 1-13, 34-1 , 46-4, 69- 22
penetrations 19-12, 28-3, 46-4, 69- 22
Corrosion 86- 8
prevention 109-20
Crash l andings 88-1 2
Crew
co-ordination 30- 18, 95-19
crewmanship 5- 3
Dangerous cargo 14- 8, 16- 11 , 21-2 1, 22 - 23 , 37-1 3 ,
50-19, 52- 21 . 66- 10, 101-26
Decompression 35 - 16 , 3 7 - 19
sickness 28-7, 43-ll
Defect diagnosis 23- 22
Dehydration 110-3
Density altitude 110-1 8
Descent
into ground 99-2
in to sea 108-26
uncontrolled 21 - 14
Directional control
loss of 3- 11 , 4- 1, 6- 22 , 53- 18 , 93- 12
Distraction 77 - 28, 83- 13 , 83 18, 88- 2, 94- 6
Ditchin g 5- 10, 5 19, 7- 6, 10-12, 16 - 20, 29-23, 33- 6,
36-4, 60-16 , 80-16, 92-25
see also Collision with water
Door open in flight 32- 10 , 63- 2 1, 76 - 19 , 87 - 8,
100-28
Do wndraft 3- 22, 5-22, 6- 9, 7- 22, 14 - 13, 30-1,
34-12, 64-1, 88- 27, 93- 24, 94- 10, 99- 2
see also Mountain wave effect, Wind shear
Drugs and m edication 8-6, 48-27 , 58-16, 63- 9,
63-19 , 85- 8 , 90-13
see also Alcohol
Dust
danger of fuel contamin ation 65- 7
excessive brake wear 111-9
Aviation Safety Digest 113 1 25
..
�Dust devils 101-20
Flat battery 105 18, 110- 13
Electrical
failure 12-1 , 75-8, 9fL 12, 98-26 , 105-19
hazard to persons 32-18, 46-14
system 105-20
Flight deck management 103- 8, 109- 8, 110- 24,
110- 28
Electronic check list l 09-6
Emergency
evacuation 26-14
landings 36- 20 , 107-20
procedures 2-1 8, 8-14 , 28-13, 36 - 20, 36- 23, 41 12 ,
56-12, 57 - 14, 69-8, 88-12 , 98 12
Engine
control 54- 23
failure 1- 23 , 2- 18, 6- 22, 7- 6, 7-10 , 8-14, 10-20,
11-25 , 11-26, 12- 12 , 12-14 , 13 6 , 13- 12 , 16 - 26 ,
18-30, 19- 24, 19-26 , 25- 28, 32- 12 , 36- 4, 36-20 ,
4 1- 12 , 44- 2, 45-8, 45 - 12 , 46 - 6 , 46 - 26, 5 1-6,
52-10 , 58-1 3, 59 - 1, 59 -4, 69 - 5, 71 - 22 , 76- 22 ,
89- 14, 9 1- 3, 91 - 7, 9 1- 11 , 91- 14
see also Fuel exhaustion
failure in light twins 105-10 , 108-3
fire 9-18, 18-4, 24-24 , 33- 6, 45- 2, 64-1 6, 83-13
intake 76-21, 83-21, 89-26.
mounting failure 62 -1 6
overspeed 10- 14 , 13 - 1, 15- 24, 20-26, 60- 10
see also Propeller runaway
power loss 11-23, 16-20, 28- 16, 50- 22 , 55-13,
64- 9 , 70- 16, 74- 14 , 76 - 23, 80- 28, 91 20 , 92- 14
technique 55 - 13
use of CHT and EGT indicators 107-12
vibrat ion 10- 21
Excess weight 5- 18, 8- 24, 10-9, 14 - 26 , 18- 23, 19 24,
23 - 18 , 30- 8, 31 - 12 , 35- 5, 82-6, 86 - 12
Fabric separation 30-23
Fatigue
metal 2-20, 15- 7, 57- 10
see also Pilot fatigue
Feathering 1-11 , 7-10 , 8-1 3 , 15- 24, 23 10, 51-6,
63- 5
wrong propeller 12- 14 , 16- 20, 19- 26, 20- 26, 41 - 12,
44- 2
Fin al apprnach 103- 8, 108- 25
Fire 1-7 , 3- 26 , 28- 26, 41- 21 , 45 - 14 , 45 - 18, 51 2 1,
55 - 9 , 63-1 2, 65 - 12, 70 - 7, 7 1-27 , 79- 6, 83-27 ,
87 - 26, 89- 20
fuel 18-31
in flight 7- 5, 9- 18, 33- 14, 64- 16
on ground 39 - 23 , 48-1 7, 50- 2 1, 64-25
_·dph" r -dust 9- 7
see also Engine fire
Firearms
• ,
carriage in aircrah .Z&- 27
Fl ap retraction after l a nding 111- 23
26/Aviation Safety Diges t 113
aerotow 42- 15 , 84-6
competition 107- 19
outlandings 62 - 2, 84- 21 , 84- 26
Glued structures 32-20, 35 -1 8
Flight planning 42-5 , 55-14, 55-supi>lement, 57-17 ,
69- 27, 88-20, 97 20 , 99- 10, 102 - 2. 105 - 8, 109- 19,
111 -28
Flight recorde1· system II0-9
Flight service 8-7 , 85-6 , 101- 22
Fog 40- 20 , 100-20 , 107 28
Food poisoning 40-22, 51-11 , 104-10
Forced landing 3- 25, 6 22 , 6 25 , 7- 5, 7 10, 8 2 1,
8-22, 8-26, 9-25, 10- 21, 11 - 25 , 11-26, 12-18 ,
14- 17, 17 26, 18 23, 21 -22, 23- 18, 23-25, 24 1,
30- 7, 30- 16, 30- 18, 34-8, 36-24 , 37 24, 39-27 ,
42- 13, 43-4, 44-2 , 45 - 12, 49 6, 50- 14, 50 22 ,
50 26 , 52 - 10, 54- 23, 55 13, 57-8, 58- 13, 59 1,
59- 2 1, 59 22 , 59 25, 65- 28 , 66- 4 , 67-7, 70- 1,
70- 16 , 71- 17 , 71- 22, 74-14, 75 - 2 , 76- 22, 77 - l ,
78- ll , 78-1 8, 78-24, 82 24, 82- 26: 85 - 9, 86 - 2,
86 19,87 2 , 92- 11 , 92 14 , 92 - 27,99-1 0,99-27 ,
103- 20
Frost 102 - 27, 106-10
Fuel
blockage 89-24
consumption l 06 - 4
contamination 12- 19, 14- 17, 24- 18, 26-22 , 30- 16,
35 -14 , 45- 8, 45-27 , 46- 6, 64 28, 65- 7, 91 3,
108 13
exhaustion 1 20, 5 10, 21 - 12, 27-4, 30-7 , 39-27 ,
40-24, 42 - 26 , 46- 18, 50- 26 , 55 - 2, 55 - 16 , 57- 17,
59- 21, 67 7 , 81 - 24, 86 2 , 88 - 14, 91- 22 , 103 20 ,
103-21, 109-16 , 112- 14 , 11 2-23
ice 109- 25
leakage 38-5, 79- 16
mismanagement 3- 17 , 6- 25, 7- 6 , 8- 21 , 8- 22, 24- 8,
28- 14, 30-18, 36 -24 , 37 - 24, 43 4, 50 14 , 59-22 ,
65- 28, 71 - 17 , 87 2 , 87 - 26, 91- 22 , 93 - 16
planning 37- 9
poisoning 90-27, 112 28
selector l 02 - 18
shu t off 104- 24
siph oning 37-14
specific gravity 112-28
systems 43-6 , 5 7 -8
tank cap 109- 18
tank vent fairing 11 1-20
theft of 59 - 21 , 98 - 27
use of wrong 13-11 , 18-9, 32- 24 , 43-27 , 50-24,
54- 22. 64 9, 74- 14, 87 - 26, 109-28
vapour lock 43 6
vents 35-10, 59- 4
Fumes in cockpit 6 1-22, 77 -1
Go-around 3-22, 8- 12, 9- 22, 12 - 7, 12- 12, 13- 25,
13-27 , 17-7, 18- 30, 29- 11 , 29- 12, 35 - 26 , 36- 16,
39-4 , 50- 2, 60- 16, 65 - 8, 90- 14, 98-2
Ground
effect 9- 3, 111-3
loops 29- 26 , 63- 24, 65- 6, 74 - 24 , 79- 27, 96-10
safety on 24-3
Gust locks 100- 4
Insects
hazards 43- 27
nests 16- 26, 49-22, 55- 21, 89 - 24
Instruments
error in reading l-1 ~46-18
see also Altimeter
failure 2- 24, 28-II , 31-6 , 64 - 27, 91 - 27, 98- 24
fl ying technique 24-13, 54- 18
see also IFR/ VFR Compromise , Cloud , Night
Jet
blast 26-13 , 50-8, 60-20, 65-1 2 , 80-11 , 98-16
intake danger 15- 2
Kangaroos 103- 27 , 106-21
Hail 37- 18 , 49- 10
Handstarting 1-9, 35- 20, 40- 3, 45- 6 , 56-14 , 65- 24,
76-1 6 , 83-11, 88- 14, 91 -14, 96-23 , 96-26, 103-12
Harness
see Safety harness
Head protection 18-1
Heavy landings 12-1 7, 14- 15 , 18- 23 , 23- 4 , 25- 24,
47 - 21 , 60-1 6, 63- 23 , 64-26 , 89-20
Helicopters 47- 10 , 60- 10, 69-8 , 82-16 , 86- 16
maintenance 109 - 22
overpitching 5 1-9
power settling 68 - 20
roll-over 91-25
Landing
expectancy 107-10
obstruction 3-28
performance 42-1
technique 6-3, 10-3, 14-5, 21 - 5, 25-8 , 29- 16,
64-1, 79- 22 , 95-19, 97-10, 111-23
Landing gear
see Undercarriage
Last l ight 12- 18 , 21- 10, 28- 20 , 49 - 13, 55 - 16, 59- 8 ,
69-27, 78- 18 , 81 - 2, 86-1 8 , 89- 8
see also Night
Licence suspension 37-22
Life jackets 92-25
High altitude flight 3-3
Lightning 39-1 0 , 40- 12, 62- 22 , 66- 24
Human faqors 19-6 , 102- 9, 103- 25, 109 - 30, 110- 29
Load
agricultural 31 - 26, 41 - 14, 56- 26
loading 11 - 21 , 31 - 12 , 56- 1
shift 23 - 8, 80- 6
see also Centre of gravity,
Excess weight
Hydraulic
fa ilure 14- 24, 32-6
fl uid con tamin ation 17-5
Hypoxia 66- 7, 101 - 23, 105-3
Loose articles 14-10, 23-11 , 41- 22 , 45-25 , 50- 7 ,
92-28
Icing
airframe 14-1 , 19 - 20 , 23-18, 25-3 , 40 - 6, 57- 16 ,
61 - 25, 62-20, 85- 24, 92- 23
carburettor 25-18 , 45-20 , 55-20, 59- 25, 61- 26,
85-18, 103-31 , 106-28 , 108-14 , 112- 24
engin e 28- 16
helicopter rotor 30- 10
pitot/ static 39-24
t hrottle 35- 2 1
IFR/VFR compromi se 7-1 5 , 8- 8, 23- 12, 31 - 24,
67- 24, 95- 2, 95- 6
Low appr oach 21°-5, 95-19
Low flying 3- 29, 5- 23 , 5- 25 , 6- 16, 6- 24, 6- 25 , 8- 23,
9- 22, 9- 26, 11 - 22, 12 - 22, 13- 25, 14- 26, 15- 28,
15-30, 16 -25, 16-26, 27-27, 28-1 , 33-9, 35-22 ,
36- 8 , 47- 2, 47 - 5, 47 - 7, 56- 8, 56-20, 60-4, 63- 1,
66 - 1, 74- 8, 74 - 24, 77-20, 78- 6, 79-6 , 79- 10, 81 - 6,
81-28 , 83- 2, 84- 16 , 97 - 2
Low jet routes 101-5
Low level turbulence 109- 10
'"
Ignition swi tch, misaligned 53- 26
ILS 9- 6 , 22- 10
G liding 9- 20 , 15- 28, 19- 10, 19- 11 , 2 1- 26 , 22 - 22 ,
27 - 22 , 33- 22, 42- 14, 54- 11, 61- 1, 62- 2, 84- 2,
84- 10, 84- 14, 84- 2 1, 90- 2, 101 - 4, 101- 17, 101- 19
Induction icing
see Icing carburettor
Incident reporting 27-10 , 32-15
immunity 24-1, 54-1 , 100- 1, 109- 14
Maintenance 5- 11 , 5- 25 , 6- 8, 8-21 , 15- 24, 17-1 ,
17-5, 17 - 19, 17- 26, 18-10, 18- 19, 19- 1, 20- 5, 22- 8 ,
22-1 6, 22-11, 23-23 , 23-25, 26- 24 , '27-4, .27- 12, 28-6,
29-24, 31-16, 33-5 , 33-1 6, 33-24, 34-1 0, 36-11 ,
36-1 2, 38-26 , 42-11, 46-26; 47-16, 47-22, 48-7,
Aviation Safety Digest 113 I 27
I
J
�49- 18, 54- 14, 56-17, 56-24, 59- 27, 60- 22, 62 - 16,
65-11 , 67 - 22, 70-22, 100- 15, 101 - 10 , 107- 30, 112- 13
Manoeu vering speed 31- 1, 107- 16
Mercy flights 25-27
Papua New Guinea operations 66-16, 100-13
Par achutin g 48- 1, 56- 13, 69-14 , 70- 11 , 101- 14
Rest r icted a reas, pen etration of 111-27
P assenger b riefin g 11 0- 29
Rotor failure 7- 23, 53-2 , 57-1, 69-8
Meteorology forecasts 109-24
Passenger evacuation 108-23
Meteors 46-8
Mil itary accidents 36- 23 , 43-14
Performance 11-7, 20-17, 27-6, 29-11 , 38-1, 61 -12,
64-10, 71-10 , 80-21 , 85 -24
see also Landing, Take-off performance
Mixture control techn ique 87-22, 106-4
Photochromic lenses 95-29
Mountai n wave effect 3- 22 , 5- 22 , 42- 6 , 57-22,
88- 27, 94- 14
see also Downdraft , Turbulence
Pilot fatigue 8-2, 12- 10 , 12-22, 17- 22, 19- 6 , 20- 18,
26- 6, 72- 10 , 86- 27, 95 - 19
M u steri ng 93- 6, 93-10, 101-25
Navigation 3-25 , 5-1 9, 21-10 , 23-1, 26-19, 31- 13,
32-16, 35-1, 39-18, 44-20 , 55-2, 55-16 ,
55- supplement , 66- 4 , 70- 1, 72-1 , 72-18 , 72- 21,
72- 28, 78- 18, 85-6, 97-16, 99- 18, 102 - 5, 102- 13
aids 33- 27 , 34-20, 53-13 , 87 - 26
equipment 109-21
e rror 12- 15 , 18- 16, 19- 12 , 26- 6, 26- 19 , 27 - ll ,
39- 18 , 41- 6, 44- 20, 47- 26, 55- 10, 72 - 10, 72- 18 ,
89- 2 , 93- 12, 11 0- 28
Near miss 74- 18 , 75- 28, 77 - 28, 108- 25
Nigh t
flight 22- 24, 52- 2, 52 - 6, 55 - 2 , 67- 24 , 72- 1, 72- 10.
78- 14, 85- 2, 93- 2 , 94- 26, 95-6, 110- 23
vision 108- 24
VMC 102- 13·
Polarised glass 109- 23
Preflight checks 28- 21 , 38-24, 42- 14, 42- 19 , 49 21,
60- 14 , 66- 9 , 93- 16 , 96- 29 , 98- 27, 107- 7
see also Cockpit checks
P r essing on (in bad weather) 16- 25, 17- 13, 18-20,
18- 28, 22- 15, 31 - 22, 60- 1, 73- 2, 79 - 2, 82 - 10 ,
82-1 9, 91 - 16, 105- 15
Profession alism 79-14
R ace (air) 82 - 24, 84- 21
Overrun 1- 24, 6- 21 , 9-9 , 17- 9 , 20- 16, 23- 21, 28- 26,
30- 4 , 45- 11 , 58-6, 65- 8, 65-20, 82-6, 90- 14, 99- 5,
101 - 2, 104- 16
Oxygen
antidote to coc kp it fumes 52-2 1, 61-22
hypoxia 66- 7, 101- 23, 105-3
oxygen systems 18-6, 4 1-21, 112-1
28 / A viati on Safe ty Digest 113
Take-off
aborted 1- 24, 18- 26, 44(-9. 53-18, 61-12, 71-1 ,
85-10, 90- 10, 90- 16, 164- 6
accidents 103-6
inadequate length of strip 50- 16, 58- 1, 67- 16
performance 1- 13 , 2-15, 5- 7, 5-2 1 7- 27 , 20-16 ,
33- 1, 37- 4, 62-19 , 62 - 20, 83-6 , 88-9, 92- 20,
103- 26, 105 - 7
weights 10-9 , 101-18, 101 -24
Taxying 1- 22, 3-24, 53- 20, 58-5
Thunderstorms 11- 3 , 31- 14 , 54- 26, 59-10, 60-6,
68-5, 82-2, 82-22, 94- 2, 94- 10, 108- 8
see also T ornadoes
Sarwatch 39-8 , 50-13
P i tot
b lockage 66- 9, 75-23
covers left on 49-14, 52- 16
icing 39- 24, 99- 24
Oleo stru t
m ain ten a nce 47-16
Outback operations 5- 6, 46- 2 1, 53-20 , 55-10,
55-supplem ent, 58- 17, 72-28, 77-6, 97-16, 97-20,
98-14
Safe ty harnesses 26-1, 34-11 , 36- 27, 99-9, 103- 4,
104- 26, 108- 6, 11 1-8
P ilot in capacitation 29- 1, 51 1, 100-26, 104 - 20
O il
exh austion 104- 28
fil ter 32- 19
on windscreen 45- 5
sh ortage 44- 9 , 46- 26
system 56- 24
Noseover 83- 17 , 103-29, 104- 22
Runway
condition 5-21 , 8-7, 9-9, 20-24, 23 -21, 85- 10,
89- 13
fo reign objects on 41-22, 45-25, 50- 7
lighting , VHF-activated 103-1 9
obstruction 107- 18
visib ility 3- 7
T-vasis 41-5
Throttle cable failur e 105- 16
P ropeller
damage 1- 22, 26- 9 , 31- 27, 34- 8, 67 22, 87 - 8,
94- 27
danger to persons 40- 10, 56- 14, 76- 16, 89-23,
96-23
failure 1- 22 , 3- 12 , 10-14 , 27- 1, 43- 16, 69- 1,
72 - 24 , 99- 21
feathering 109-9
ha ndling 35- 20
maintenance 18-10, 72-24
p itch angle 2-14, 6- 12 , 9- 11, 17- 9 , 33- 20, 35-26
runaway 13-1
see also Engin e overspeed, Handstarting
Noise 37- 20
Remote areas
see Out back
Rad ar 24- 6, 40- 5
R adio
comp ass 23- 1
failure 22- 7, 45- 13, 46- 27
knowledge of equipmen t 100-23
procedures 38- 28, 42-28, 47- 19, 4 7- 27 , 52- 13 ,
68- 22
see also Communications
Refuelling 1- 7, 42- 28, 47 - 19, 47 - 27, 55 - 9 , 63- 12,
104- 30
Tie-down 110-6, 112-18
Scuba d iving, flight after 28- 7 , 43-11
Search and r escue 25 1, 25- 28, 36- 3, 77 - 1, 86- 21,
91 - 20, 101-28 , 102-24, 103- 22 , 104- 27 , 105- 28
Tiger Mot h
technique 81-14
Tornadoes 54-26
Seats, security of 62- 14, 96-28, 111-26 , 11 2- 26
Sensor y illusions 2-5, 3-9 . 7- 8 , 16- 1, 18-23 , 20- 8 ,
20-21, 35-6, 37-25, 74-8, 75-2, 75-18, 96-14
see also Visu al illusions
Separation, aircraft traffic 19-3, 35 - 1, 61- 10 , 94-28,
102- 14
see also Con t rolled airspace
Spins 1- 22, 3-20, 5- 23, 10- 17, 10 - 22, 10- 23, 16 - 28 ,
19- 18, 21- 26, 22 - 22, 26- 10, 30-3, 31- 26 , 54- 11 ,
61- 6, 69- 1, 84 - 2, 104-20
Chipmunk 22-1
spira l d ive 15- 28, 75-12
Stalls 2- 24, 3-22, 3-29, 5-18, 5- 21 , 5- 25 , 6- 24, 7- 25,
8- 23, 9- 22, 11 - 23, 14-21 , 16-25, 18- 7, 19 - 20,
20- 1, 21 - 12 , 21 - 26, 21 - 27 , 30- 3, 34- 14 , 34- 19 ,
37- 10, 42- 15, 43-8, 44- 11 , 45- 12, 47 - 2, 47- 5,
48- 10, 56-1 , 56 -8, 56- 26, 77-20, 78- 6 , 79 - 10,
83- 6, 84- 21 , 84-26, 88- 9 , 89-14, 92-2, 92 - 7 ,
92- 20, 93-6, 93- 10, 94-22, 97-6, 99- 24, 101 - 18
Statisti cs, Au str alian air safety 87-1 2, 110- 30
Structural
d amage 49- 16, 54- 21, 65- 12, 76- 12, 77 - 17, 88- 24,
90- 28
failure 2- 20, 5- 25, 9- 20, 11-16 , 14- 15, 15 - 28,
. 21- 1, 21-6, 23-4, 24- 4 , 25 - 24, 27- 3, 28- 12, 31 - 1,
33- 22, 34 - 24, 35- 18, 43-20, 46- 12, 51- 20, 57-10,
59- 10, 68-5, 81 - 10 , 82 - 2 , 83- 13, 86- 8, 90 - 2, 94-2,
107- 16
limits 30-3 , 38- 1, 46 - 12, 76-12, 90- 2 ,
loose part 46- 11 , 59- 20, 78- 11
Stu den t p ilots 91 - 3, 91-8
see also T raining
Su rvival 46- 21 , 50- 26, 77-6
Training 1- 11 , 1-22, 3- 20, 4- 1, 6- 12, 6- 17, 8- 13 ,
10- 22, 10- 23, 11-27, 14-21 , 19- 8 , 19- 18 , 24-20,
26 - 10 , 42- 13, 56- 5, 59- 22, 63- 5, 65- 8, 76- 26, 93- 2
see also Student pilots
Trim 15- 5, 32-22, 46- 1, 48- 10, 59- 27, 70- 14
Turbo-charger failure 103- 30
Turbulence 13-10, 16- 18, 21-1 , 21 - 25 , 25- 7, 30-17
43- 20, 52-22 , 57-10 , 57- 22, 59- 10, 60-6, 67-12,
68-5, 82-2, 82-22, 93- 24, 94- 2
see also Wake tu rbulence
T urning b ack (after engine failure on ta ke-off) 89-14,
92- 7, 93- 16
Tyres 23- 17, 49- 21
U n de rcarriage
collapse 58-14, 60 - 22 , 64-26, 67- 16, 69- 16, 70-24,
89- 20
d amage 69- 12, 110-4
difficulty 58- 13, 98- 12
down d uring flight 5-7, 14- 24, 59- 19, 92- 18
fail ure 33- 15 , 49- 18, 60- 22 , 66- 12, 83-23, 98- 28
retraction on ground 1- 21, 5-14, 18- 26 , 19 - 8 ,
23-23, 32- 22, 69- 24, 76- 14, 94- 27
system 111 - 14
warning light 59- 15
see also Wheels-up landings
U ndershoots 3-15 , 5-17, 12- 17 , 21 - 13, 26- 16, 43-12,
61-24, 64- 1, 76-2, 78- 14, 80- 26 . 93- 20, 93-24
Unsu itable
landing a rea 5-25, 7- 26, 39-4, 42-20, 47-26, 50- 2,
55-14, 58- 6, 58-18, 58- 20 , 61- 20 , 65-20 , 67- 19,
70- 1, 70- 11 , 74-2 1, 78- 18, 96- 21, 100-24, 103-29
Aviation Safety Diges t 113 1 29
�take-off area 3- 26, 6- 21, 6- 22 , 9 24, 12- 19, 28- 24,
45- 10 , 50- 16
see also Take -off, inadequate leng th of strip and
Agricultural strips
recon naissance 104- 3
weather -related accidents 100 20 , 110 24 , ll 1-4
see also H a il , Lig htning
Fifty years on
• •
. the TIGER MOTH
Welding 33-5
Vapour locking 43-6
VHF-activated lighting 103-19
Visibility 3- 7, 3- 31, 6- 25, 9- 23, 10- 10, 13- 21, 17- 21,
37- 1, 45-26, 48- 18 , 57 - 16, 59- 25, 61 - 24, 70-19,
76 - 2 , 84- 16, 89-20, 91 - 28 , 95-29 , 97-29, 98 - 8
Vision
blind spot 106-3
eye protection 101-11
sunglare 107- 3
night vision 108-24
Visual illusions 37-25 , 78 - 1, 78- 14 , 93- 20, 103-8 ,
110-24 , 111-10
see also Sensory illusions
Wheel
failure 49- 18
loose 39- 7
Wheels-up landings 1- 10, 6- 26, 14-4, 14 25, 29-12 ,
39 - 27 , 50 - 27 , 51 - 21, 62- 10, 66 - 12, 68 18, 83-18 ,
92-18 , 98- 12 , 98 28, 11 0 -26
Wind
gusts 1- 24
shear 6- 9, 14 13, 30-12, 31-14 , 34-12 . 94 - 10 ,
98 20 , 101 -2, 103 8 , 106-14, 106 22 , 110 24
see also Downdra ft, Landing techni.q ue
Win dscreen 45-26, 74- 2 1, 97-29
Winter operations 25-4 , 85-16
VSB (ELT) beacons 91- 20
Wake turbulence 2 - 16 , 21-6 , 31-20, 51-14, 54 - 25 ,
63 - 14, 65-16 , 87 - 20, 94- 28 , 95-10
heavy helicopters 104-11
Weather 1- 20, 3- 17 , 5- 19, 8- 8, 8- 17, 13-2 1, 14- 18 ,
16 - 14, 16 - 18 , 26- 16, 31-18, 38 - 25, 39-10 , 40-12,
49- 10, 52-22 , 54-26, 60-6, 62-22, 66-24 . 73- 17 ,
74- 1, 79- 2, 81 2 , 87- 16, 92 23, 104- 18 , 105 26 ,
106- 7, 109- 26
forecast 106-26, 109-24
Notes:
30 I Aviation Safety Digest 113
Wire strikes 3 26 , 5 23 , 6 16 , 6 24 .• 7 23, 8 25 , 8 26 .
8- 27, 9-21 , 9 25, 11 22 , 12-4, 12 21 , 12 22 ,
13 24 , 15-27 , 15 30 . 18-1 , 20 19 , 21 18 , 25 14. ,
28- 22, 3 1 28 , 35- 22, 36-1 , 36- 8, 36 18, 39 4 ,
47 - 7, 56 - 16 , 56-20 , 58 17 , 59 16, 60- 4. 63 17.
64-14, 64-22 , 66 I, 67-1 , 67 3 , 67 5, 67 7. 67 10 ,
67 - 19, 68-10 , 68-16 , 70 7 , 70 26 , 74 24. 79 6 ,
80 28, 83 - 2, 86 2 . 88 14, 88 16 , 96-4. 98 8.
102 8, 108-19
·w ooden str uctures 19-1
In this age of m ass production and glossy p roducts,
row upon row of sleek modern des igns confront us
at any airfield we may visit. sr:na ll , medium a nd
large , of varying hues, these atrc rafl perform a
wide variety of tasks in relative comfort and
efficiency ... ... but are they 'aeroplanes'?
As one walks the lines of modern aircraft, more
often than not an a nachron ism appears amongst
them , immedi ately identified as a ' real aeroplane'.
Its antiquity is apparent : two wings, open cockpit
and fabric covering, held together by wire , and
nearly always in immaculate condition . This is a
TIGER MOTH .
The Tiger Moth evolved from the De H avilland
DH- 51 of 1924 and its successor , the DH-60 Moth
of 1925. The DH -60 engendered a line of variants
culmina ting in the DH -60T Moth Trainer , first
Oown in Apri l 1931. Of the 72 DH -60Ts built ,
eight were constructed with a small amount of
sweep- back on the main planes a nd d esignated
Tiger Moth, the second De Havill and type to bear
this name. (Th e fi rst was the Monopla ne DH-71
Racer of 1927 .) In turn , one of these eight was
further tested with dihedral on the lower wing and
increased sweep -back, effecting a change of type
number to DH-82.
Bearing the Class B test m arking E-6, airframe
number 1733 - the first true DH -82 - made its
first flight at the hand s of De H avi lland's test pilot
Hubert Broad on 26 October 193 1 at Stag Lane
Aerodrome, Middlesex. Built to meet Air Ministry
Speci fication 15/3 1 the design led to immediate
military orders, and a total production of 135
examples of this model followed . Designated MKl
by the RAF it was powered by the 120 HP De
Havilland Gipsy MKIII eng ine. T he prototype,
registered G -ABRC, received its Certificate of
Airworthiness on 18 March 1932 and served with
De Havillands for m a ny years. At the outbreak of
war it was impressed into military service and
alloted serial number BB723. After serving in RAF
and RN units it was sold as surplus in January
1951 and scrapped in 1953 without being reregistered. No exam ple of either the DH-60T or
DH-82 came to Australia
contrary to popular
belief.
The Tiger Moth as we know it in Australia is
the type DH-82A, the major production version of
the design. This variant was the result of Air
Ministry Specification T26/ 33 which called for
installation of the De Havilland Gipsy Major MKl
engine of 130 horsepower and other design
changes including a plywood turtle-decking in
place of the fabric-and-stringer structure , an
incre ase in fuel tank capacity from 18 to l 9
gallons, elimination of the deep front-cockpit door
and installation of a fixed rear seat in place of the
adjustable seat of the DH-82. The first DH-82A,
airframe number 3175, was registered as G-ACDA
and certificated on l 0 March 1933. At the
outbreak of war this aircraft was impressed and
subsequently saw service with both the RAF and
RN . Known to th e RAF as the MKII, 8811
examples of this sub-type were constructed .
A further 420 T igers were built with wooden
DH-60GIII fuselages. These were designated DH82B 'Queen Bee' target a ircraft. Some Car:iadian
production was designlled DH-82C, a vanant
which included those fitted with the Menasco D4
Pirate engine of 120 horsepower and the De
Havilland Gipsy Major MKIC of 145 horsepower.
The Tiger Moth in Australia
The first Australian Tiger Moth , VH-UTD, was
placed on the register on 28 May 1935. This was
the 126th production aircraft and carried airframe
number 3320. It was the fore-runner of 18 civil
and 20 military examples imported prior to the
outbreak of war. Another six arrived in 1940 for
civil use. Of those 24 civil-registe red Tiger Moths,
three were purchased by the RAAF and 18 were
impressed.
VH-UTD became Al7-675 on 22July 1940 and
saw service with No. 8 Elementary Flying Training
School at Narrandera, NSW.
As t he war progressed Australia undertook to
train aircrew under the Empire Air T raining
Scheme and, as p art of this commitment,
production of 350 Tiger Moths was started at De
Havilland's Mascot Factory. Ultimately 11 35
aircraft were constructed there, the last 65 being
delivered unassembled . Of the 1070 aircraft
assembled, one was released directly to Broken Hill
Aero Club as VH-AEB, two went to Burma, 18 to
the USAAF, 20 to the RNZAF, 41 to India, 62 to
the Netherlands East Indies, 96 to Rhodesia , 120
to South Africa and 712 direct to the RAAF . As
well , 100 British built ex-RAF aircraft were
shipped here, bringing the total number of Tigers
in Australia by the end of the war to 1127 . RAAF
serial numbers ranged from Al7-l to Al7-759.
Post-war, the majority of the military Tiger
Moths were entered on the civil register. The type
was used for practically every purpose imaginable ,
a lthough prima rily in the training and cropdusting roles . A few were placed on floats and
several were fitted with canopies. Many were
priva tely owned . Of the original 21 civil Tiger
Moths acquired by the RAAF eig ht were returned
to civil use post-war. One of these was airfram e
nu mber 3623, origina ll y imported as VH-UYQ.
T his aircraft was re-registered VH-CCE in
Novem ber 1955 a nd is now the oldest surviving
Tiger Moth in Australia. (It has been in storage
since 1975.) VH-UTD - the origina l Australian
Tiger Moth - was written off in Fe bruary 1945
after an accident in which it stalled a nd spun in.
In 1954 there were still more than 300 examples
of the Tiger Moth on the register and high
numbers were maintained until t he mid-sixties .
The current register lists well over 100 examples
- not a bad record for a type that ceased
production in Australia 37 years ago •
Aviation Safety Digest 113 I 31
�
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1982
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https://collections.heritageoftheair.org.au/files/original/5cabf434e94b1d745e58173a6d9898b8
64ba9f6fe661b16ae5a78fddd0666823
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�ATransport
Systems knowledge ·equipment
\4VAustralia
Continuing on from the article in Aviation Safety Digest 105 on physiological aspects of high
altitude flight, this article discusses the use and care of oxygen equipment and is intended to
provide an insight into the requirements for the use of oxygen, the types of oxygen equipment
available and some general rules for oxygen safety. It is by no means a complete treatise on the
subject and should only be considered as a starting point for further study.
Contents
3
Systems knowledge -
8
Review of free distribution list
8
RAAF Diamond Jubilee lithographs
9
Throttle linkage separation in flight warnings ignored
1O
oxygen equipment
Be aware of the options
The pilot of a DHC-2 Beaver elected to abandon takeoff following engine malfunction.
11
Landing performance
A Twin Commanche suffered substantial damage when
it struck a boundary fence after landing . The pilot
failed to consider aircraft performance and existing
c ircumstances.
12
Nesting places
13
Cleaning and lubrication of landing gear
14
Fatal accident following fuel exhaustion
17
Helicopter self-destructs
A Hughes 269 helicopter destroyed itself within five
seconds after suffering main rotor imbalance. The
cause was con j ectured to be an apparently minor
oversight in maintenance.
17
Corrigendum
Illustration to 'Vision 4 Safety Digest 111.
visual illusions' In Aviation
18
Notes on the care and use of ropes
20
Improper assembly of glider causes loss of
control
22
Encounter with flutter
23
More on unlocked seats
28
Fuel specific gravity
T
I
The Assistant Director (Sales and Distribution),
Australian Government Publish ing Service,
P.O. Box 84, Canberra, ACT 2600.
Subscript ions may also be lodged with AGPS Bookshops in all
capital c ities.
Reader contributions and correspondence on articles should be
addressed to:
The Assistant Secretary (Air Safety Investigation),
Department of Transport,
P.O. Box 18390,
Melbourne, Vic. 3001.
Printed by Ruskin Press, 552-566 Victoria Street, North Melbourne,
Victoria.
Loose foreign objects
The pilot of a Cessna 152A was engaged in a period of
solo aerobatic flying when the ail erons jammed. The
cause was interference by a foreign object.
30
I
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries and notifications of change of address should be directed to:
RM79/30212(1) Cat. No. 80 3259 X
26
29
The Publications Distribution Officer,
Department of Transport,
P.O. Box 18390, Melbourne, Vic. 3001.
Decision making
Induction icing
--.
Readers on the free list experiencing problems with distribution or
wishing to notify a change of address should write to:
Elevator tab flutter in a Cessna A188B Agwaggon
24
29
Aviation Safety Digest is prepared by the Air Safety Investigation
Branch and published for the Department of Transport through
the Australian Government Publishing Service, in pursuance of
Regulation 283 of the Air Navigation Regulations. It is dist ributed
by the Department free of charge to Australian licence holders (except student pilots), registered aircraft owners and certain other
persons and organisations having a vested operational interest in
Australian civil aviation.
©Commonwealth of Australia 1981. The contents of this publication may not be reproduced in whole or in part, without t he written
authority of the Department of Transport. Where material is indicated to be extracted from or based on another publication, the
authority of the originator shou ld be sought. The views expressed
in articles reproduced from other sources are not necessarily
those of the Department.
A helicopter pilot engaged in survey operations
recently made a series of decisions which culminated
in engine failure due to fuel exhaustion.
oxygen
Front cover
Wing of a Boeing 707 (Matthew Tesch)
Aircraft lifting procedures
Back cover
Bird strike reporting
Hang-glider built and f lown by Otto Lilienthal in the 1890s
(Cheryl Poon)
2 I Aviation Safety Digest 112
Aviation Safety Digest 112 I 3
�But first, a brief review of the effects of reduced
atmospheric pressure on the concentration of
oxygen in the blood to illustrate the reasons for
the various features of oxygen systems and the
limitations placed on some systems.
The critical factor in the prevention of hypoxia
is the alveolar oxygen tension, i.e. the oxygen
pressure within the air sacs of the lung where
oxygen crosses the lung/ blood vessel barrier and
moves into the blood stream. At sea level in the
standard atmosphere this pressure is 103mm Hg
and is a function of the partial pressure of the
oxygen in the inspired air. Because the
atmospheric pressure, and therefore the oxygen
partial pressure, decreases as altitude increases the
alveolar oxygen tension will also decrease.
This progressive reduction will, initially , have
little effect on human performance. But a point is
reached where the pressure falls to a level too low
to maintain a sufficient blood oxygen
concentration and the first effects of hypoxia
appear. At altitudes below 10 OOO feet these effects
are mild and acceptable, but above this altitude
human performance degrades very rapidly and the
use of suppleme!ltary oxygen is essentia l.
T h e object of breathing supplementary oxygen
is to increase the concentration of oxygen (and
oxygen partial pressure) in the inspired air to
maintain the alveolar oxygen tension at a safe
level. In this manner, sea level alveolar oxygen
tension can be maintained to about 33 OOO feet,
above which it falls progressively, even when 100
per cent oxygen is breathed, and a point is
reached where the oxygen must be delivered under
pressure.
Oxygen systems
Oxygen systems are designed to deliver a
concentration of oxygen to maintain at least a
defined minimum a lveolar oxygen tension with
increasing altitude. The demands placed on
oxygen systems to achieve this are, in general,
prescribed by the altitude to which they are used.
Accordingly, th ree distinct types of system have
evolved. These are: continuous flow (for use up
to 25 OOO feet), demand (for use up to 40 OOO
feet) and pressure demand (for use above 40 OOO
feet); although there are concessions on the use of
demand equipment above 40 OOO feet, and
continuous flow equipment is approved for
passenger use above 25 OOO feet.
Oxygen systems in general use consist of three
main components: a store of oxygen, a regulator
and a mask. Each is connected by appropriate
p lumbing and delivery hoses.
Continuous flow oxygen system -
typical operation
Oxygen storage
Most aircraft that operate routinely above
10 OOO feet are fitted with a gaseous oxygen supply
system. The oxygen is stored in high pressure
(12 400 kPa) cylinders and is delivered at reduced
pressure through appropriate plumbing, pressure
reducers and check valves to the regulator and
then to the mask.
Passenger supplementary oxygen in some
modern aircraft is generated chemically. Small
chemical generators supply the oxygen in a
continuous flow to the mask in the event of a
pressurisation failure, to provide protection against ·
hypoxia for the passengers while an emergency
descent is made.
+
Oxygen
Fig 1
Oxygen is delivered in a continuous flow to a storage bag
attached to the mask.
4
Oxygen
Fig 2
When the user inhales, oxygen in the storage bag is drawn
into the lungs and the storage bag deflates.
Oxygen regulators
The following descriptions of the three types of
oxygen regulators - continuous flow, demand
and pressure d emand - are of a general nature to
provide an understanding of the principles and
application of the different types . For detailed
information concerning a particular installation,
reference should be made to the appropriate
operating instructions for that installation.
Continuous flow. In most continuous flow
systems the oxygen is delivered from the regulator
in a continuous flow to an inflatable storage bag
attached to the mask. As the user inhales, oxygen
in the storage bag is transferred to the lungs and
QLRCK- RELEASE SOCKET
Ambient
rnr
+
Oxygen
Fig 3
Continued inhalation then draws in cabin air to satisfy lung
capacity and to achieve economy in the use of oxygen.
1NO PILOTS MASK
Exhaled
air
+
Oxygen
Fig 4
When the user exhales, used air i s expelled and the storage
bag re-inflates.
DROP OUT HASK UN115
CONTENTS lllQl(ATOR
(''(
\ST PJLOlS
MASK
CABIN
OEHAhD
REGULATOR
I
(HAR GING
PASSENGER
_.,...CONTINUOUS.
FLOW
REGULATOR
L'.:== = = : ( ) PASSENGER
- SUPPLY VALVE
OXYGEN SYSTEM- SCHEMATIC.
4 I Aviation Safety Digest 112
TOIL£1
VALVE
I
CONTENlS
/1NO IC AlOR
the bag deflates. Continued inhalation then draws
cabin air into the mask through holes or an inlet
valve in the mask to satisfy lung capacity and to
achieve economy in the use of oxygen.
When the user exhales, the storage bag starts to
inflate again and the used a ir is expelled. Some
masks a llow mixing of some of the used air and
incoming oxygen in the storage bag during
exhalation. The exhaled air contains a significant
amount of oxygen, and rebreathing helps reduce
the waste of oxygen by allowing a lower flow rate
from the regulator. The concentration of oxygen
in the lungs (and therefore the a lveolar oxygen
tension) is determined, among other factors , by
the amount of oxygen in the storage bag before
inhalation which, in turn , is a function of the flow
rate from the regulator and the user's breathing
rate. In some systems the flow rate is progressively
increased with altitude to compensate fo r the
progressive reduction of the oxygen partial
pressure - this achieves an economy in the use of
oxygen at lower levels. Automatic systems
incorporate a barometric control that senses cabin
pressure altitude and automatically regulates the
flow rate to the requirement for that altitude,
while manual systems require the pilot to set the
cabin pressu re altitude with the altitude controller
on the regulator.
Aviation Safety Digest 112 I 5
�Continuous flow systems cannot provide
additional oxygen flow to cope with extra demand
due, for example, to an increase in activity or
differing individual needs. Consequently , many
are designed to deliver an excess of oxygen to
ensure that an adequate concentration is always
available.
Continuous flow systems are the type most
commonly fitted to piston engine general aviation
aircraft and passenger oxygen supplies of other
aircraft. They are approved for use by flight crew
on flight deck duty to 25 OOO feet.
Demand systems . For flight above 25 OOO feet
flight deck crew must be provided with demand
equipment.
Demand regulators - a lso referred to as diluter
demand - deliver a mixture of oxygen and air
when the user inhales, and automatically match
the amount of the mixture delivered, to the
demand. A slight pressure reduction in the mask
and delivery tube on inhalation opens the
regulator demand valve and oxygen flows. When
the user stops breathing or exhales, the demand
valve closes and the oxygen flow stops.
In conventional demand systems the oxygen to
air ratio delivered by the regulator is controlled
automatically by a barometric capsule. From sea
level to near 10 OOO feet the regulator, if used,
would deliver only air. Approaching 10 OOO feet
(normally at about 8 000 feet) oxygen flow starts
and the oxygen to air ratio increases progressively
with altitude until, at about 30 OOO feet , 100 per
cent oxygen is being delivered. One hundred per
cent oxygen can be selected at any altitude. When
this selection is made the air mix valve in the
regulator is closed and only oxygen is delivered
when the user inhales. T his function is useful
when smoke or fumes are present in the cabin.
Demand systems may b e used up to 40 OOO feet.
Such systems are often approved for aircraft
certified to operate above 40 OOO feet , but such an
approval is based on design and operational
characteristics of the aircraft.
Pressure demand regulators. For fligh t above
40 000 feet an aircraft may be required to be
fitted with pressure demand equipment. Pressure
demand regulators function in the same m anner
as diluter demahd regulators at the lower levels
where pressure breathing is not required, but start
to deliver oxygen under pressure soon after
the air m ix valve closes. The delivery pressure
increases automatically with altitude to a
maximum of about 30mm Hg above cabin
pressure - the m'a ximum that can be effectively
tolerated without the application of external
counter-pressure to the head and chest.
Pressure breathing systems are normally used in
aircraft in which a rapid loss of cabin pressure
could occur at high altitude. Their function is to
protect the flight crew from hypoxia while an
emergency descent is made to a lower level where
pressure delivery is not required .
Pressure breathing is a difficult and tiring
exercise. It is a n unnatural mech a nical process
that must be consciously controlled. Inhalation
requires conscious muscular effort to control the
volume and flow rate of oxygen as it is forced into
6 I Aviation Safety Digest 112
the lungs by the regulator. Further muscular effort
is then required to exhale and hold against the
delivery p ressure until ready for the next breath.
Pilots of aircraft fitted with pressure delivery
systems should undergo training and experience
decompression and pressure breathing before
flying at high altitude. Courses are conducted by
the RAAF Institute of Aviation Medicine at RAAF
Base Point Cook, Victoria . Details may be
obtained by writing to:
Director,
Vic/Tas Region ,
Department of Transport,
PO Box l 733P,
Melbourne Vic. 3001 .
(Attention OFAO)
or by telephone: (03) 667 2420.
Pressure breathing systems require a good maskto-face seal. Any outward leakage will redu ce the
oxygen pressure in the mask a nd lungs, and may
also make it impossible to stop the flow of oxygen
between breaths.
Oxygen masks
Oxygen masks vary in style from lightweight
plastic disposable masks for use with continuous
flow systems to complex units incorporating the
regulator, inhalation and exhalation valves,
microphones and special h arnesses to facilitate
rapid donning. Regardless of their complexity, the
purpose of the mask is to cover the nose and
mouth and deliver oxygen to the lungs. Pilots
must be as familiar with the procedures for the
use and care of th e mask as they are with th e rest
of the oxygen system. Masks designed for use with
demand and pressure demand regulators need
particular care an d protection to ensure their
serviceability. A small amount of dirt in the outlet
valve, for example, can p revent the operation of
the regulator through inward leakage , or cause an
outward leakage under pressure.
Modern pressure demand system incorporating the mask and
regulator in combination.
Servicing and maintenance of oxygen
systems
..
Rapid donning facility is achieved by inflating an expanding
harness with oxygen.
Oxygen installations are potentially dangerous if
improperly installed or poorly maintained. Any
equipment that is unserviceable or shows evidence
of inadequate or improper maintenance should be
repaired or replaced.
Aircraft oxygen systems should be serviced only
with oxygen produced to an approved
specification. The specifications (listed in AN O
108.26) prescribe the maximum acceptable
concentration s of specific impurities and specify
cleanliness standards for storage an d h andling
equipment.
Refilling of oxygen systems sh ould be conducted
only by a properly qualified person. The servicing
equipment sh ould b e approved and it must be
scrupulously clean. Most h azards in oxygen systems
occur because of th e use of dirty recharging
equipment resulting in the entry of dirt and
contaminants to the a ircraft system.
Considerations on the use of oxygen
Before using any aircraft oxygen installation the
pilot must study the operating instructions for that
equ ipment and be thoroughly familiar with its
operation. The following comments relate to the
use of oxygen systems in general.
• Ensure that the installation has been properly
serviced and contains enough oxygen for the
intended flight.
• Conduct a thorough preflight inspection of the
system - inclu ding masks. Use a checklist if one is
available.
• Ensure that all components of the system are
compatible. There are different types of hose
connections for continuous flow systems and not
all are compatible. Incompatib le items cannot be
joined without the u se of force. Do not use force.
• Ensure that the equipment is ready to use and is
accessible so that it may be quickly donned and
operated in an emergency. You cannot maintain
adequate oxygenation during a loss of cabin
pressurisation by h olding your breath! Only a
timely application of supplementary oxygen will
p revent the rapid onset of h ypoxia and possible
loss of consciousness . Remember, the period of
useful consciousness following rapid loss of cabin
pressure at 30 OOO feet is only about one m inute
on the average, and can be substantially less in
some cases.
• Brief your passengers on the use of oxygen
before flight. Describe th e symptoms of h ypoxia to
them and brief them to be alert for those
symptoms in one another.
• Do n ot smoke or permit smoking when oxygen is
in use. In an oxygen-rich a tmosphere combustion
is accelerated dramatically and many materials
that will not normally ignite burn readily.
• Ensure a proper mask seal , particularly with
demand and pressure demand systems. An inward
leak will cause excessive dilution of the oxygen
and m ay prevent operation of the demand valve.
An outward leak will reduce mask pressure during
pressure breathing. Beards and improper
adjustment of mask retaining strap s impair maskto-face seal, and di rt may prevent mask inlet and
outlet valves from seating properly.
• Monitor oxygen flow indicators. Rememb er that
the ability to breathe from a regulator does not
guaran tee that oxygen is flowing. Some system s
allow the user to continue to breathe after a
failure of the oxygen su pply. Again , study th e
operating instructions for the equipment an d know
the indications of correct operation.
• Periodically check h ose connections and system
contents, and ch eck your passengers and their
oxygen equip ment.
• As soon as possible after a cabin decompression
check th at you r passengers are receiving oxygen
and supervise them during the time oxygen is in
use .
• Ensure that the oxygen is turned off when not
in u se . Wi th h igh concentrations of oxygen the
risk of fire increases dramatically. The d anger is
normally associated with oils or grease, but in a
recen t overseas incident, cheese in a crewmember's
sandwich ignited when it was exposed to oxygen
flowing from a mask. (There are also several
Aviation Safety Digest 112 I 7
�recorded cases of burns suffered when lip balm
ignited spontaneously under an oxygen mask).
• Before flying above 10 000 feet understand the
physiological requirements for the use of oxygen.
Departmental requirements and
specifications
Departmental requirements concerning the
provision and use of oxygen, and the specifications
for oxygen equipment for operations up to 40 OOO
feet are covered in Air Navigation Orders. The
requirements for oxygen systems intended for
operations above 40 000 feet are determined
individually according to the type of aircraft and
operation.
Briefly, for flights in unpressurised aircraft
above 10 OOO feet oxygen shall be provided for,
and used by, all flight crew on flight deck duty for
the duration of the flight above that altitude. For
flights in pressurised aircraft oxygen shall be
provided for, and used by, all flight crew on flight
deck duty for the entire time that the cabin
pressure altitude exceeds 10 OOO feet.
Pilots should be conversant with ANO Part 20
Section 20.4 before operating above 10 OOO feet.
Details of oxygen systems and equipment
specifications are contained in ANO Part 108
With the growing numbers of turbocharged and
turbine engines in general aviation aircraft,
more and more pilots are discovering the advantages of flight at levels that require the u se
of oxygen. Before embarking on such flights,
pilots should be thoroughly familiar with the
physiological effects of high altitude flight,
including the cause and effects of hypoxia, and
the effects of loss of cabin pressurisation.
Similarly, they must have a thorough knowledge of
the operation of the oxygen system in their
aircraft.
Properly used, an oxygen system will allow great
flexibility and economics in the operation of your
aircraft. On the other hand, improper use or
inadequate knowledge of your oxygen system could
spell disaster •
Review of free distribution list
RAAF Diamond Jubilee lithographs
In Aviation Safety Digest 111 I1980 we asked
recipients of the Digest who are not holders of an
Australian flight crew or maintenance engineer
licence (or on e of the other categories entitled to a
free copy), to respond to a questionnaire and
confirm their wish to remain on the Digest free
distribution list . We a lso invited all readers to
comment on the format and content of the
publication.
The response to the invitation to make
comments or suggestions was particularly
gratifying. At first we attempted to reply
individually to all those responses, but the task
soon became overwhelming.
We plan to publish a brief analysis of the
responses in Aviation Safety Digest 113. In the
meantime, we wish to assure readers that a lack of
personal acknowledgement should not be taken as
an indication of indifference to their suggestions,
and to express our appreciation to those who
responded to the survey .
The free distribution list for Australian readers
has been reviewed, and the amended list was used
for the distribution of this volume of the Digest.
However, for reasons undetermined, overseas
readers did not receive Digest 111 until after the
nominated closing date for responses.
Consequently, the overseas list has not yet b een
reviewed e
To commemorate its Diamond Jubilee, the Royal
Australian Air Force has produced 16 lithographs
of RAAF aircraft. The series is the first full-colour
p ictorial coverage of representative aircraft flown
by the RAAF during its six decades of service to
the nation.
The aircraft include the Avro 504K of the
1920s; artistic impressions on one lithograph of the
Bristol Bulldog, Supermarine Southampton and
Hawker Demon of the 1930s; the CAC Wirraway,
Lockheed Hudson, Wackett Trainer, de Havilland
Tiger Moth and Douglas Dakota of the 1940s; the
GAF Canberra, CAC Sabre, CAC Winjeel of the
1950s; the Lockheed Hercules, GAF-CAC Mirage
111-0 and Bell Iroquois of the 1960s; and the
Lockheed Orion and General Dynamics Fl l lC of
the 1970s. As a special bonus, the 1912
Deperdussin appears in colour at Point Cook for
the first time.
The lithographs, which measure 42 centimetres
x 30 centimetres, are ideal for wall mounting or
framing. They could a lso be bound into a
commemorative book as a fitting keepsake of an
important milestone in RAAF history.
The lithographs are available in two sets of
eight. Set One features aircraft from 1921 to 1951 ,
and Set Two from 1951 to 1981. They can be
purchased from Australian Government Publishing
Service bookshops in capita l cities for $4.00 per
set , or ordered by mail from AGPS, P.O. Box 84,
CANBERRA A.C.T. 2600 for $4.50 per set e
8 I Aviation Safety Digest 112
Throttle linkage separation in
flight - warnings ignored
Section 108.26. While this information is mainly
of a technical nature, pilots should be familiar
with it for a full understanding of system
specifications and servicing practice. Copies of this
ANO may be obtained from:
Department of Transport (Attention EPSD)
PO Box 1839Q
Melbourne, Vic. 3001.
Conclusion
1
The pilot was flying his own aircraft on a sheep
mustering task when he was faced with a forced
landing on unsuitable terrain. He was unable to
regain power after closing the throttle. The engin e
was running at idle but operation of the throttle,
which felt 'sloppy', had no effect on RPM. At that
time the aircraft was at 500 feet above undulating
terrain and the most suitable area for landing was
a rough rocky upslope sparsely covered with trees
and saplings. During the landing roll the a ircraft
was substantially damaged by the rough terrain
and from impact with trees. The pilot and his
passenger escaped injury.
Investigation showed that the throttle arm had
separated from the drive shaft on the carburettor
because the lock screw which clamps the arm to
the shaft had worked loose. The lock wire had not
been effective in preventing movement of the
screw and ha d eventually broken due to working
as the throttle arm rotated around the drive shaft.
The pilot had not opened the engin e cowling
since the last 100 hourly inspection . He had
noticed some intermittent free play in the throttle
control over the few days preceding the accident
and had noted that rapid throttle movements were
not necessarily reflected by rapid engine response.
However, he had n ot considered there was
an ything mechanically wrong with the engine.
The loss of throttle control was contributed to
by a design weakness rectified in later model
carburettors which have a more positive
connection of the arm to th e shaft. In this case
the pilot could have prevented the accident by
investigating an abnormal indication.
Although he had been aware of slackness in the
throttle control for some 20 hours, h e made no
attempt to identify the cause.
Pilots must be alert for the ap pearance of
abnormalities of operation in their aircraft. Ea rly
recognition and investigation of a developing fault
may well prevent a disastrous failure •
Aviation Safety Digest 112 I 9
�Be aware of the options
Landing performance
...
The pilot of a DHC-2 Beaver commenced
superphosphate spreading operations early in the
morning. He was operating from a good
agricultural strip 3200 feet above sea level. The
strip was some 800 m etres long and the take-off
run was down a one per cent slope. T h e
surrounding terrain was rugged a nd heavily
timbered.
By 0830 hours local time 10 flights had been
completed. Conditions were good with nil wind
and clear skies. Temperature was around zero
degrees Celsius. Early in the next take-off run the
pilot thought h e detected a miss in the engine, but
all power indications were normal and there was
no vibration. About half way along the run th ere
was a loud b ang from the engine . The pilot closed
the throttle, simultaneously applied full brake,
and pulled the hopper lever to dump .
Brake effectiveness was reduced by the frosty
grass surface and the pilot could see that he would
not stop in the remaining distan ce. He briefly
considered trying to swing the aircraft, but
decided against this course of action as the sloping
ground around the strip was covered with trees to
one side and stumps and logs to the other. The
complete load of 916 kilograms of superphospha te
had been dumped b y the time the aircraft h ad
reached the end of the strip .
T he aircraft continued off the strip and through
a wire fence . After rolling 30 m etres beyond the
fence down a five per cen t slope, speed had been
reduced to walking pace. At this point fallen logs
caused the aircraft to very slowly nose over on to
10 I Aviation Safety Digest 112
its back. Several tree stumps penetrated the
starboard wing as the aircraft nosed over, an d the
top of the rudder was bent. Other damage was
minor .
The pilot released h is harness and vacated th e
aircraft. He then n oticed a fire in the exhaust
manifold, so he retrieved the fire extinguisher
from the cockpit and extinguished th e fire.
A general outbreak of fire th en occurred, fed by
fuel that was now flowing freely from the fuel tank
vent p ipe outlet under the port wing. This intense
fire destroyed most of t he fuselage , the in board
sections of the win gs and much of the engine
before being brought under control with water
pumped on to the fire with a hand pump. The
port wing was destroyed wh en fuel vapour inside
the wing exploded.
The cause of the engine malfunction was failure
of number one cylinder h ead resulting in a partial
power loss. The pilot briefly considered the
possibility of dumping the load and flying a
circuit ; however, he discarded that option and
decided to abandon the take-off beca use of the
nature of the surrounding terrain. (If the surface
of the strip had not been frosty the aircraft might
have been stopped in the remaining distance
without damage) . H ad he hesitated in rejecting the
take-off, or elected to continue, a far more serious
accident could well have resulted.
T here is a lesson in this for us all - be aware
of the options at all times. This not only redu ces
decision time should an emergency arise, but also
leads to good decisions e
After an uneventful travel flight on a late autumn
afternoon , t he owner/ pilot of the Twin Comanche
arrived over his farming property in south western
Victoria. T wo grass strips were available: one was
670 m etres long an d aligned north east/ south west,
the other was 550 m etres long and aligned north
west/ south east . T h e windsock was ind icating a
light and variable breeze with a south westerly
tendency.
Because th ere we re cattle 'camped' on the long
strip, the pilot elected to land towards the sou th
east. As the aircraft approached to land the pilot
thought th ere was also someth ing on the closer
end of that strip . O n finals it was determined that
there were two or three sheep there.
The aircraft crossed th e fence at 80 knots with
full flap down and th e pilot added a little power
to pass over the sheep. Touchdown was made at
the intersection of th e strips which left 369
metres available for the landing run. The pilot
braked h ard and the recently replaced brake pads
did their job well. The wheels locked up and
skidded along the wet grass surface which was very
soft and 'greasy' from the 75 millimetres of rain
which had fallen during the previous eight days .
When it became obvious that the aircraft would
not stop, the pilot applied power to th e left engine
to try and induce a gro und loop. The aircraft
veered off the strip to th e righ t, struck a boundary
fence and suffered substa ntial damage.
Following th e accident th e pilot indicated that
he had considered a go around after touchdown
but was concerned that the aircraft would not
clear the power lines near the far boundary of the
strip. He did ackn owledge that a go aroun d from
the approach would have been th e correct action.
A check of the landin g weight chart from the
aircraft flight manu al revealed that, for a lan d ing
in the prevailing m eteorological condition s on a
level surface, the d istance required was 488
metres. This is the distance required to bring the
aeroplane to rest on a level, short-dry-grass
runway from a height of 50 feet above the
threshold following a steady approach to land, a t
a speed of 73 knots, with the aircraft in the
landing configuration and maximum braking
applied immediately after touchdown .
The ground roll, under ideal conditions, could
be expected to be approximately 60 per cent of
the above. Therefore, a realistic stopping distance
on a level, dry surface would have been about 300
metres, not far short of the actual distance
available.
Unfortunately, the strip was not level but had a
downhill slope of a bout three per cent from the
point of tou ch down. The effect of the slope alone
would increase the ground roll required to a figure
in excess of that available; add a very wet grass
surface and the pilot obviously had no hope of
stopping th e aircraft before the boundary fence.
The total required landing d istance as given in
the a ircraft flight manual is in excess of 600
metres for a runway slope of two per cent
downhill, the maximum given on the performance
ch art. Putting asid e the fact that , in landing on a
three per cent downslope , the p ilot was operating
outside th e approved performance boundary for
his aircraft, a runway slope of this magnitude
would increase the landing distance to well in
excess of 800 metres.
Once again a pilot did n ot give enough
consideration to the landing performance of his
aircraft. Had he consulted the performance charts
and thought a bout the factors affecting the
landing, his self protection responses should have
alerted him to the degree of difficulty in achieving
a satisfactory landing under the existing
circumstances e
Aviation Safety Digest 112 I 11
�Cleaning and lubrication of
landing gear
Nesting places
•
The speed and tenacity of some birds when
attempting to build nests sometimes needs to be
seen to be believed. This first-hand report from a
pilot illustrates the problem:
'Having left my plane, a Cessna 182-H , parked
one Friday afternoon, I returned at noon on
Sunday to find a note tucked under the door
handle. It said: "Check your engine for myna
birds. Found a nest in the 150 this morning ." And
written obviously later was the addendum, "3.15
pm, there is a nest in this engine. "
'On peering into the ventilation opening beside
the spinner, I could see the remains of a nest
which our unknown friend had removed for us .
There seemed to be more grass and sticks still
remaining, enough to start a fire, so I pulled the
top cowl off to get. rid of the remains, and found
yet another large nest on the same side back near
th~ firewall; a mass of small sticks and grass .
Pnme fuel for a fire in flight!
'It took us nearly an hour to get rid of it all ; if
it had not been for a friendly and concerned
fellow pilot we might very well have been in
trouble. On leaving a note of thanks on his 150,
parked nearby, I noted that he had a mosquito
net barring entry for the mynas. '
The following extract from an incident report
shows what can happen when the bird nest is not
found before the engine is started.
'As the aircraft had not been flown for eight
days, I wanted to ground run it before flying it
12 I Aviation Safety Digest 112
the next day. I checked the fuel for water;
inspected control surfaces, tyres, struts, pitot head
and, finally, the engine and propeller - checking
oil quantity and for foreign objects. All appearing
in order, I started the engine and taxied to the
run-up bay where I carried out a complete run-up
and check of the radios and navigation aids. I
noticed a faint smell during the run-up but
assumed the source to be oil spilt around the
engine. After I stopped the engine in the parking
bay dense smoke appeared from under the cowls. I
extinguished the fire and removed the cowls to
find the remains of a bird's nest in the engine .
The nest was concealed from my view at my prestart inspection. '
Aircra~t .structures o~fer many attractive nesting
?pportum.t1es for a van~ty of birds and winged
msects, with the potential for causing serious
accidents. These two accounts say enough about
the fire potential of nests in engines. Other
problems are encountered when bird or insect
nests obstruct vents, pitot heads, cooling air
intakes for electronic equipment etc. and interfere
with flight control movement. A thorough beforeflight inspection is always important. But in the
nesting season or when the aircraft has been
unattended for som e time the importance of
conducting a meticulous inspection, including a
detailed visual check of possible nesting areas,
cannot be over-emphasised e
..
The malfunction of retractable landing gear
continually appears as a factor in air safety
incident and accident reports. This is particularly
true in the case of general aviation aircraft
operating from dirt or grass strips. Airworthiness
Advisory Circulars, which are distributed to
aircraft owners, operators and maintenance
engineers, also regularly contain articles about
problems ~ssociated ~ith retractable landing gear.
Because pilots are quite often responsible for
ensuring the completion of the daily inspection,
and are always responsible for the safety of the
aircraft and its occupants, the following two
articles from AACs are presented.
AAC 116-9, Piper PA-31 landing gear downlock
hook defects, deals specifically with problems
associated with the Piper PA-31 Navajo aircraft
and malfunctions due to dirt preventing normal
operation of the gear:
'Over the last two years there has been a spate
of defects associated with the PA-31 main landing
gear downlock system. The majority of defects
resulted in air safety incidents. The b asic cause of
these defects was dirt ingress into the hook and
rod end. Binding of the downlock hook assembly
then prevents its proper functioning, which leads
to rivets shearing in the downlock rod, cracking of
the bearing boss, and , of course, faulty operation
of the landing gear.
'Frequent cleaning and lubrication of the
mechanism would eliminate t hese problems.
Although the maintenance schedule requires it to
be cleaned, inspected and lubricated at 100 hourly
intervals, operators should check it more
frequently if they are operating the aircraft in a
harsh environment. A few minutes taken up by a
check could well save much time and expense later
on should the gear fail to operate correctly.'
Following the release of AAC 116-9 we checked
the air safety computer records and surprisingly
found that there were equally as many occurrences
reported of PA-31 gear malfunctions following
cleaning of the gear. The culprit this time was the
lack of subsequent lubrication. This prompted us
to reprint AAC76-3 , The good oil (or have you
had any hangups lately?):
'With the fitment of retractable undercarriages
to an increasing range of general aviation aircraft
types, there h as been a steady increase in the
number of landing incidents associated with
undercarriage malfunctions. A large proportion of
these can be attributed to defects arising from
faulty maintenance practices .
'For example, in a recent incident the nose gear
of a light twin did not fully extend because the
actuator-to-drag-brace attach bolt was seized due
to lack of lubrication. Admittedly there was no
nipple through which grease could be applied to
the bearing surfaces. However, lubrication means
using an oil can as well as a grease gun, and in
this case the regular application of a drop of oil
would have prevented an expensive incident.
'The servicing of modern aircraft relies as much
on common sense and good maintenance practices ·
as on detailed instructions to be found in the
"manufacturer's recommendations" . It is
impossible to detail every step or foresee every
eventuality in the wide spectrum of operating
conditions. Following another recent incident
involving an aircraft operating continuously in
dusty conditions, the operator complained to the
Department that lubrication at every 100 hours, as
recommended by the manufacturer for that
particular undercarriage mechanism, was
obviously not sufficiently frequent. Unfortunately
there is nothing the Department can achieve in
such a case by approaching the manufacturer.
The latter determines maintenance minima for the
benefit of operators and never undertakes to
guarantee that these minima are sufficient for all
possible conditions. He advises the operator on
maintenance in order to facilitate aircraft
operation, but neither he nor the Department
intends to run the operator's business.
Departmental airworthiness action is only initiated
when a safety problem is detected on an aircraft
type and, in the case of maintenance , when the
minima recommended by the manufacturer are
insufficient in general application. In the case
above it would be obviously unreasonable to
impose a 50 hour schedule on all operators
because the 100 hour p eriod is inadequate for a
very few. Therefore if your aircraft is in need of
lubrication , lubricate it without waiting for the
manufacturer's invitation, a Department
Airworthiness Directive or for a seized hinge in
one of the undercarriage legs.'
Obviously both of the preceding AACs are
applicable to operators of all aircraft with
retractable landing gear. The message is clear: If
you operate an aircraft with retractable landing
gear, ensure that the gear is clean and lubricated
before flight. If it is dirty, clean it. If you clean it,
lubricate it. If you are unsure about how to clean
or lubricate the landing gear, talk about it with
the operator and his m ainten ance organisation e
Aviation Safety Digest 112 I 13
�Fatal accident following fuel
exhaustion
Zone. A clearance to track to Essendon via Clifton
Hill at 1500 feet was given promptly, and after
reporting at Clifton Hill at 1506 the aircraft was
instructed to make a visual approach, join left
base and report final for Runway 26 . One minute
later the pilot transmitted a MAYDAY call,
advising that he 'appeared to have a fuel problem'
and that he would have to land on a golf course at
his present position. Shortly afterwards, the
aircraft colliJed with trees during a turn and
crashed in a nose down attitude. onto the golf
course, only eight kilometres from Essendon
Airport.
Investigation revealed that neither engine was
delivering power at impact. The landing gear was
down and the flaps were partially extended, but
neither propeller was feathered.
At 1508 hours a Rockwell Shrike Commander SOOS with one pilot, a passenger and a load of freight
crashed onto a golf course near Essendon Airport, Victoria, following fuel exhaustion on a flight
from Flinders Island to Essendon. Both occupants were killed, and the aircraft was destroyed by
impact forces.
Investigation
•
History of the flight
T he aircraft had departed Essendon at 1335
hours on the day before th e accident with a load
of freight for Cambridge, Tasmania. The flight
was conducted on an IFR flight plan without
recorded incident and took 121 minutes. T he
freight was unloaded at Cambridge and the
aircraft was then flown empty to Launceston,
where freight for Flinders Island was loaded.
Flight time to Launceston was 32 minutes. The
aircraft departed Launceston at 1720 hours and
the pilot reported arrival Flinders Island to Flight
Service at 1746 hours - a reported flight time of
26 minutes. However, the evidence indicates that
the aircraft did not arrive at Flinders Isla nd until
some time after the reported arrival time, and
calculations based on witness evidence, fligh t
manual performance data and known
meteorological conditions su ggest th at a more
probable flight time was 35 minutes.
Next morning, the pilot submitted an IFR flight
14 I Aviation Safety Digest 112
plan for a flight from Flinders Island to Essendon
quoting a flight time of 91 minutes and an
endurance of 214 minutes, corresponding to a
margin of 64 minutes over IFR reserves. The
planned route was via Wonthaggi and Plenty at
4500 feet. Freight on this flight consisted of frozen
fish and fresh crayfish.
The aircraft departed Flinders Island a t 1329
hours. Forty on e minutes later, at 1410 hours, the
pilot reported to Melbourne Flight Service tha t he
was experiencing 50 kn ot headwinds at 4500 feet
and advised of his intention to descend and
proceed VFR. The flight plan ground speed
suggests that this headwind was 20 knots stronger
than expected. The pilot reported his position at
Tulip at 1432 hours, five minutes later than th e
flight plan estimate. At 1502 hours he called
Essendon Tower approaching Channel 0 (now
Ch annel 10, a VFR reporting point in the
Melbourne terminal area) with a request for an
expedited clearance into the Melbourne Control
Fuel. Prior to departure from Essendon the
previous day the aircraft had been fuelled to
capacity and, in addition, three 20 litre drums
were filled with fuel and placed in the aircraft
baggage compartment. No additional fuel was
taken on at Cambridge , Launceston or Flinders
Island, although fuel was available at both
Cambridge and Launceston. Furthermore,
investigation revealed that the drums placed in the
aircraft at Essendon were full and in the aircraft
at the time of the accident.
Aircraft loading. Calculations indicate that on
departure Flinders Island the aircraft gross weight
was approximately 4060 kilograms, more than 800
kilograms over the maximum take-off weight of
3243 kilograms for IFR operations. Similarly, at
Essendon and Launceston the gross weight at takeoff had been in excess of the maximum take-off
weight . The freight from Flinders Island consisted
of frozen fish in 10 kilogram packs , two bags of
fresh crayfish and 86 kilograms of miscellaneous
freight. None of the freight was tied down or
secured against movement.
The pilot. The pilot held a current First Class
Airline Transport Pilot licence and was in fulltime employment as an airline captain with a
major operator. He was also involved financially
and managerially with the company operating this
aircraft. Neither the company nor the pilot held a
Ch arter or Aerial Work licence, and the names of
another pilot and another operator were used on
the flight plan.
Both the pilot and the company were
experiencing financial difficulties at the time and
there was evidence that the p ilot had overloaded
the aircraft on other occasions. Furthermore, some
fligh ts had not been recorded in the maintenance
release.
Examination of the pilot's fl ying log book
revealed that no flight times had been recorded in
the four months preceding the accident. His total
aeronautical experience was about 8500 hours , of
which 88 h ours 55 minu tes was recorded as Aero
Commander experience. His actual Aero
Commander experience at the time of the accident
could not be determined.
Aircraft serviceability. The investigation did
not reveal any defect or malfunction in the
aircraft. However, examination of the engines and
propellers revealed that neither engine was
delivering power at impact. There was no
significant fuel in the fuel system. There was no
suggestion of fuel or oil system contamination, nor
was there anything to suggest that any fuel system
component was unserviceable before impact.
Examination of the aircraft maintenance
records revealed a number of discrepancies, but
there was no evidence to suggest that any
maintenance deficiency had contributed to the
accident.
Flight plan endurance. The flight plan showed
an endurance of 327 minutes on departure
Essendon , and 214 minutes at Flinders Island .
Flight time from Essendon to Flinders Island was
188 minutes, excluding the time intervals between
take-off and departure at Essendon, Cambridge
and Launceston. No fuel was added at
Cambridge , Launceston or Flinders Island.
Therefore the endurance on departure Flinders
Island must have been less than 139 minutes,
assuming the original endurance of 327 minutes
was accurate. Endurance required at brakes
release Flinders Island was 150 minutes,
comprising: 91 minutes flight fuel, 14 minutes
variable reserve and 45 minutes fixed reserve. The
accident occurred following fuel exhaustion 99
minutes after the reported departure time from
Flinders Island.
Fuel consumption data. The flight plan
recorded an endurance of 327 minutes with full
tanks on departure Essendon, and indicated that
the planned cruise speed was 180 knots TAS.
Assuming this was based on use of 75 per cent
maximum continuous power and best economy
mixture, in the expectation that this would
achieve 180 knots TAS , the calculated endurance
using manufacturer's performance data from the
flight manual would have been 332 minutes,
including 45 minutes reserve at 45 per cent
maximum continuous power. That endurance
figure includes an allowance for engine start , runup , taxi and take-off, and for the higher fuel flow
with maximum continuous power set during climb
to 4000 feet. After leaving Essendon, the aircraft
made three additional take-offs, thereby reducing
the above endurance to about 307 minutes. Fuel
used during the climb following each of those
take-offs would have further reduced the amount
of fuel available for cruise, but because of the
gross overload of the aircraft, climb performance
figures can only be estimated. Assuming an
average climb time of six minutes and maximum
continuous power for the climb, the higher fuel
flow would have contributed to an endurance
penalty of about seven minutes , further reducing
the original endurance of 332 minutes to about
300 minutes. On the reasonable assumption that
cruise power was maintained to fuel exhaustion on
the last flight , the endurance would be further
reduced by 17 minutes to 283. minutes, 44 minutes
less than the flight plan figure.
Fuel exhaustion occurred after some 287
minutes. The close agreement b etween the
calculated and actual endurance may well be
coincidental; there are many unknown factors ,
Aviation Safety Digest 112 I 15
�and the assumptions made may have resulted in a
solution that is purely academic. But the figures
do show that there is at least one operating
configuration that is compatible with fuel
exhaustion after the known flight time of the
aircraft.
The greatly overstated flight plan endurance of
214 minutes at Flinders Island, implying a margin
of 64 minutes over the flight fuel and reserves
required for the flight, does not appear to be the
result of any miscalculation or obvious
mathematical error, nor does it support a possible
erroneous belief by the pilot that he had
transferred the drum fuel to the aircraft tanks.
Analysis
There was evidence that on other occasions the
pilot had operated to less than statutory fuel
reserves a nd that he was apparently unconcerned
about landing with as little as 10 gallons of fuel
remaining after a long flight . But it would be
difficult to accept that he would have knowingly
undertaken the flight with insufficient fuel to
reach his destination. O n this assumption, two
hypotheses emerge. Firstly, that he totally
overlooked the question of fuel; and secondly, that
he believed there was sufficient fuel in the tanks to
satisfy his own reserve requirements, and
unforeseen events eroded those small reserves
during flight.
T he flight plan was submitted to Launceston
FIS by telephone three and a half hours before
departure from Flinders Island. T he rest of the
morning was spent in arranging freight for the
flight to Essendon. T his apparently took longer
than anticipated. A number of witnesses st ated
that, at the aircraft, both the pilot and the
passenger were in an obvious h urry to depart. The
pilot had arrived at the aircraft about an hour
before take-off and conducted a run-up while
waiting for the freight to be delivered. He then
supervised the loading operation and departed as
soon as the freight was loaded. In his haste, h e
may h ave forgotten to tran sfer the drum fuel to
the aircraft tanks - had that been his intention.
Although the drum fuel would n ot have been
sufficien t to satisfy statutory reserve requirements,
an accident would h ave been avoided - on this
occas10n.
The following examination of the second
hypothesis will be similarly inconclusive, but will
illustrate how a number of seemingly minor ·
factors can combine to consume meagre reserves.
T he flight plan endurance on departure Essendon
was 327 minutes. The flight from Essendon to
Flinders Island took 188 minutes and involved en
route stops at Cambridge and Launceston. Fuel
allowan ce for start, taxi and departure at those
places and at Flinders Island would have reduced
the endurance by about 30 minutes, leaving about
110 minutes for the flight fro m Flinders Island to
Essendon . T h e flight plan time interval to
Essendon was 91 minutes, leaving about 20
minutes reserve on the basis of the foregoing
calculations. The p ilot may h ave arrived at a
similar figure and accepted it as adequate. For the
16 I Aviation Safety Digest 112
purpose of the following discussion that is the
assumption.
A stronger than expected headwind increased
the planned flight time to the site of the accident
(a little over one minute from Essendon at cruise
speed) to 99 minutes. Nine minutes of the '20
minute reserve' were thus eroded by headwinds.
The endurance profiles in the manufacturer's
handbook for this aircraft are based on a usable
fuel capacity of 156 US gallons at a density of six
pounds per US gallon, or a specific gravity of
0.72, giving 936 pounds of usable fuel. That
specific gravity is not representative of all A VGAS
100 available in Australia. Varying grades of
crude oil and differing manufacturing processes
will produce A VGAS with a specific gravity range
from about 0.69 to 0. 73 at 15 degrees Celsius,
allowing up to four per cent difference from the
figure used in the performance data calculations.
T his will be reflected in a similar percentage
difference in the endurance available from a given
volume of fuel (see article on page 28).
Laboratory analysis of the small amount of fuel
recovered from the aircraft fuel tanks revealed
that the specific gravity of that fuel was 0.69 at 15
degrees Celsius. Assuming that the endurance
shown on the flight plan on departure Essendon
h ad been calculated from the flight manual
endurance profiles, the figure obtained would
have been approximately four per cent higher
than the actual endurance available. The
endurance given on the flight plan (327 minutes)
would then be reduced by 13 minutes, reducing
the assumed endurance of 110 minutes at Flinders
Island to 97 minutes. The engines failed through
fuel exhaustion 99 minutes after depar ture from
Flinders Island.
If the flight had been conducted with at least
the required reserves, the effect of the lower
specific gravity of the fuel would have been
relatively insignificant. But the combination of
higher than expected winds and low specific
gravity fuel was sufficient to erode a calculated
reserve of about 20 minu tes to zero . Had the
endurance been confirmed by comparing the
calculations against fuel actu ally remaining, the
true nature of the fuel state should have been
revealed. On the evidence available it seems
unlikely th at the pilot had dipped the fuel tanks ,
and it was reported that he believed the fuel
contents indicator under-read b y 10 gallons,
although nothing was fo und to support such a
belief.
Conclusion
This accident would not have happened if the
aircraft had carried fuel to satisfy statutory fuel
reserve requirements. However, the investigation
suggested that , while the pilot h ad previously
operated with less than statutory fuel reserves,
other factors intervened on this flight to erode
what meagre reserves h e may have had on
departure Flinders Island. T hose factors were:
higher than expected headwinds, fuel specific
gravity lower than that against which flight
m anual endurance and range data are calculated,
and an erroneous belief that the fuel contents
indicator under-read.
Although the specific gravity of the fuel was
lower than the assumed figure of 0. 72 the aircraft
was suitably instrumented to allow detection of the
discrepancy between theoretical and actual fuel
flows caused by this difference. The p ilot may
have misinterpreted the discrepancy and assumed
a fuel contents indicator error of 10 gallons to be
the explanation for lower than expected fuel
readings at the end of a flight. This error equates
to about 20 minutes endurance at high cruise
power settings - the reserve that the evidence
suggests may have been expected by the pilot.
Operation with less than the required fuel
reserves and a belief that the fuel contents
indicator under-read, probably combined to result
in fuel exhaustion on this flight and had probably
led to operations close to fuel exhaustion on other
occasions •
Helicopter self-destructs
A recent report from our New Zealand counterparts in the business of air safety investigation
illustrates the degree of damage which can occur as the result of a very small amount of improper
maintenance.
'The Hughes 269 helicopter was to land at a
helipad and collect two passengers. After landing
on the pad , the helicopter was left running at
2500 RPM with the collective fully lowered while
the pilot waited for his passengers to board the
aircraft. Without warning the helicopter suddenly
lurched and tore the cyclic control from the pilot's
hand as the aircraft commenced to shed pieces of
the airframe . T h e situation rapidly deteriorated
and the helicopter destroyed itself within five
seconds.
'The subsequent investigation indicated that the
helicopter had suffered a serious main rotor
imbalance. A comprehensive examination
eliminated ground resonance as a cause factor and
attention was concentrated on the rotor head area
which h ad been severely damaged in the break-up
sequence.
'The casting of one of the main rotor dampers
was found to have fractured adjacent to its
attaching bolt and allowed the complete damper
to separate from the rotor head. There was
considerable fretting around the damper
attachment bolt which passes through the blade
grip. The nut h ad been stripped from this bolt
an d no remains of a locking split pin were found.
If the split pin had been missing from the bolt this
would have allowed the nut to back off and the
bolt to work with the lead-lag action of the
damper. (This would account for the fretting
found on the bolt and hammering that had
occurred between the damper face and the blade
grip). This movement could then have progressed
to the point where extra loads experienced in the
gusty conditions could have stripped the thread
from the nut an d transferred a ll the torsional
stresses to the damper case adjacent to the other
retaining bolt. The overload failure of the casing
in this area would then prevent any further
restraint of its main rotor b lade in the lead-lag
direction and almost immediately lead to a
massive main rotor imbalance and the type of
damage encountered. Examination of the failed
components supported this hypothesis but did not
eliminate other possibilities, e.g., that the split pin
had been in place and the nut had been either
undertorqued or threadbound. Any of the three
possibilities could have led to the nut being
stripped from the damper retaining bolt.'
There may be some degree of conjectu re as to
which hypothesis is the most probable cause of the
failure; however , any one of the three reasons
postulated could have been prevented with a little
more care d uring maintenance. For the sake of
either a few cents worth of split pin, or a few
extra minutes of careful maintenance, the
h elicopter was destroyed. How fortunate it
occurred on the ground, not a short while later! •
Corrigendum
Figu re three on page 12 of A viatz"on Safety Dig est
No . 111 / 1980 illustrates a section of the article,
'Vision 4 - Visual Illusions'. It refers to a pilot's
natural tendency to displace h is approach path
upwards or downwards when approaching a
sloping runway.
Unfortunately the captions of the last two
diagrams of the illustration were transposed
during printing. As the diagrams depict, the
captions should state that the pilot's natural
tendency is to correct downwards to intercept his
'natural' approach path to an upsloping runway
and upwa rds, to a downsloping runway •
Aviation Safety Digest 112 I 17
�Notes on the care and use of
ropes
whether to use a rope or to replace it must depend
on an assessment of its general condition. If after
examination there should be any doubt about its
safety, it should be withdrawn from service.
The nature of a fibre rope is such that damage
is easily sustained and the consequent weakened
condition is not always visibly evident. Constant
vigilance throughout the life of the rope is
therefore necessary.
Storage of rope
Proper storage is essential. Ropes should be
stored in a dry place , but never in closed
containers which do not permit the circulation of
air. T hey should not be stored directly on the
floor or ground; use wooden gratings or racks, or
special coil pegs on stands.
Never store rope in the weather or in direct
sunlight and avoid storage near racks of heavy
objects whose inadvertent fall may result in
damage .
Ensure that sparks from any source cannot
reach stored rope and store well away from
chemicals or other agents which may cause
damage, especially liquids which may leak from
containers.
Causes of damage
After completing his daily inspection the pilot
found that the battery was fl at, so he decided to
hand start the engine of his Cessna. He applied
the hand brake and, as an additional precaution ,
tied the tail of the aircraft down with a 1Omm
diameter synthetic tie-down rope. When the
engine started the brakes proved to be ineffective.
Furthermore, the tie -down rope broke with little
apparent strain and the aircraft was damaged in a
collision with a parked vehicle . The reason for the
failure of the brakes to restrain the aircraft was
not determined .
This occurrence raised some questions on the
degrad ation of ropes when exposed to the
elements , and prompted some discussion on the
care and maintenance of ropes used for aircraft
tie-down . The article 'Tie Down Sense' in Aviation
Safety Digest 110I 1980 discussed aircraft tie-down
procedures but did not address this subject.
The d eterioration of ropes wh en exposed to
rough treatment and the elements can be
significant without the damage being obvious in a
casual inspection. T he following notes condensed
from the Australian Standard Specification for
Fibre Rope (AS 1504-1974) should provide pilots
18 I Aviation Safety Digest 112
General external wear. External wear due to
dragging over rough surfaces can cause
filamentation. T his is the most readily noticeable
cause of weakness, particularly if a new rope is
available for comparison. In the extreme, the
str ands becom e so worn that their outer faces are
flattened and the outer yarns severed . In ordinary
use some disarrangement or breakage of the fibres
on the ou tside of the rope is unavoidable and
h armless if not too extensive. Synthetic ropes have
good abrasion resistance.
Local abrasion as distinct from general wear
may be caused by the passage of the rope over
sharp edges whilst under tension and may cause
serious loss of strength. Slight damage to the outer
fibres and an occasional torn yarn may be
considered harmless, but serious reduction in the
area of on e strand, or somewhat less serious
damage to more th an one strand, should warrant
rejection . Protection at points where excessive
abrasion may occur is economic.
with some guidance on the selection and
m aintenan ce of tie-down ropes for their aircraft.
Care of ropes
Ropes made from an y material are liable to
wear and mech anical damage, and can be
weakened by various agencies such as chemicals,
heat and light. Regular inspection is necessary to
ensure that the rope remains serviceable.
It must also be emph asised tha t no matter what
agency has weakened the rope the effect will
generally be more serious on the smaller sizes than
on the larger. Consideration should, therefore , be
given to the relationship between the su rface area
of the rope and the cross-section.
Examination at intervals of about a m etre at a
time is desirable, the rope being turned to reveal
all sides and untwisted slightly to allow
examination between the strands.
To define a standard of acceptance or rejection
is much more difficult than to describe th e
m ethod of inspection. There can be no welldefined boundary between ropes which are safe
and those which are not, because this depends on
the stresses imposed in service . The d ecision
I
..
Cuts, contusions, etc., or careless u se may
cause internal as well as external damage. They
may be indicated by local rupturing or loosening
of the yarns or strands.
Internal wear caused by repeated flexing of the
rope, particularly when wet, and by particles of
grit picked up may be indicated by excessive
looseness of the strands and yarns or the presence
of powdered fibre.
Overloading. Repeated overloading may cause
permanent deformation of the fibres which
reduces the ultimate strength of the rope. Vinyl
ropes are less prone to gradual loss of strength
than natural fibres.
Mildew or other micro-organisms do not
attack synthetic ropes; however, growth can occur
on manila and sisal ropes under damp or humid
con~itions. If a rope should become wet, carefully
dry it out under natural atmospheric conditions,
clean it if necessary and store again in the correct
manner.
Chemical action.
• Natural fibre. Acids, alkalis, other chemicals,
fuel gases, industrial d usts, ashes, and similar
hazard s will reduce the strength of natural fibres .
• Synthetic fibre. A wide range of synthetic
materials may be used in rope making. Each of
them can be affected to a greater or lesser extent
by various chemicals such as organic solvents,
acids and alkalis. No attempt will be made in this
article to describe the effects in detail; suffice it to
say that if such contamination is known or
suspected to have occu rred, expert advice should
be sought as to the identification of the fibre and
the effect of the contamination.
Hea~ or excessive surging may cause fusing of
synthetic rope . Any signs of this would obviously
warran.t rejection, but a rope may be damaged by
heat without any such obvious warning. Manila
and sisal ropes should not be stored under
conditions of high heat or excessive drying
atmospheres. Once again, the best safeguard is
proper care in use and storage. A rope should
never be dried in front of a fire or stored near a
stove or other source of heat.
Sunlight. Excessive exposure of all textile fibres
to sun ligh t will weaken the fibres and unnecessary
exposure should be avoided. Polyethylene and
polypropylene ropes are more susceptible than
others. Degradation is marked by breakage of the
fibres into small p ieces which gives the rope a
hairy appearan ce as a result of the broken ends
tending to stand up from the surface. As
degradation proceeds the fibres may even break
d own into a coarse powder. The effect extends
p rogressively below the surface of the rope and,
because it is p rimarily a surface effect, small ropes
will become unserviceable quicker than large
ropes.
At many aerodromes tie-down ropes are left
lying on the ground attached to the tie-down
anchor while the aircraft is flying . This is a
convenience that facilitates subsequent tie-down,
but ~t exposes the ropes to damage from a brasion,
sunligh t and weather. Operators who follow this
practice should inspect the ropes for damage at
frequent intervals and be p repared to replace
~hem periodically. T.he cost of a replacement rope
1s small corn pared with the cost of aircraft repairs
f~llowing failure of a tie-down rope in heavy
wmds •
Aviation Safety Digest 112 I 19
�Improper assembly of glider
causes loss of control
At the start of operations for the day, four
members of a gliding club were detailed to
assemble a Skylark glider. After the assembly, one
of the members , who was appropriately qualified ,
carried out and signed for the daily inspection of
the aircraft.
The pilot who was to fly the Skylark arrived at
the club after the assembly h ad been completed.
He ascertained that the daily inspection h ad been
done and completed his pre-flight inspection
before the aircraft was towed to the taxiway
intersection where the Pawnee tug was waiting.
After completing the cockpit checks the pilot
closed the canopy and signalled for the tow rope
to be connected and the tow to commence.
As the ground roll began, the left wing of the
glider dropped and contacted the runway. The
pilot applied full right rudder and, as the wings
levelled, the glider lifted off. The right wing then
started to drop and the pilot released the tow rope
at an estimated height of 15 to 20 feet. By then
the aircraft was turning to the right and heading
off the runway towards the grass. The right
wingtip contacted the ground, the glider swung
further to the right and the fuselage struck the
ground heavily. The aircraft slid sideways and
came to rest pointing back along the flight path.
The main and left wingtip skids broke off and the
cockpit area and tail unit were substantially
damaged . Fortunately the pilot was not injured.
Investigation revealed that the pin which normally
connects the aileron rod to the operating arm had
been omitted during assembly.
The daily inspection of the glider included a
check of the controls. T he person responsible had
checked that the ailerons moved freely and in the
correct sense by moving the control surface and
observing the correct movement of the other
aileron and control stick. He had also checked that
control stick movements were reflected by full and
free aileron surface movement. The pilot also
carried out a coc~pit ch eck of the controls and did
not detect any abnormality. Apparently the
aileron operating arm was resting on the control
rod and there was enough friction between the
two to provide continuity of the control run
(without them being pinned together) while the
aircraft was static. However, when airloads
provided an external force the friction was
overcome and the aileron control became
disconnected.
T he glider was assembled without reference to
rigging instructions or the inspection checklist.
Although there is a detailed description of the
assembly sequence and an inspection checklist in
the p ilot's notes some club members were not
20 I Aviation Safety Digest 112
aware of this. The pilots were well-practised in the
assembly procedure and apparently believed that
reference to the rigging instructions or the
inspection checklist was unnecessary. That is,
unfortunately, a common human frailty. When a
task is simple or becomes well-practised the use of
checklists tends to fall into disuse. A checklist can
perform a valuable function in reminding us to do
certain things and assisting us to do those things in
a logical sequence; but to be effective it must,
obviously, be used conscientiously .
Responsibility for the prevention of occurrences
such as this one lies, in the first instance, with the
aircraft designer. He should make such an
assembly procedure as 'pilot proof as possible. In
addition, the operator needs to identify potential
trouble areas and devise ways of preventing errors
being made. In many cases simply making 'safety
critical' areas obvious may suffice . This can be
achieved by the use of flags or tell-tale markings.
Ideally, the device used should not only be obvious
but should also prevent operation of the system or
aircraft until it is removed. (For example a control
lock that also locks the throttle in a powered
aircraft). Further, those areas that are critical ,
such as control system connections, can be
identified a nd listed on the daily inspection
certificate for individual signature and, if
appropriate, independent inspection.
While none of these measures is infallible any
measure taken to reduce the reliance on human
memory for the execution of cri tical steps or tasks
will be reflected in a safer operation e
•
Lower right.
Aileron operating arm and control rod were not pinned
together.
Aviation Safety Digest 112 I 21
�Encounter with fIutter
Decision making
All pilots are subjected to pressures from many different sources in their daily operations a,nd these
must influence the pi lot's decision-making processes to some extent, either consciously or
subconsciously. The following article is a typical example of how such pressures can affect the
operation of an aircraft.
While engaged on superphosphate spreading in
hilly country the pilot of a Cessna Al88B
Agwagon experienced severe buffeting of the
elevator control. He closed the throttle and the
buffeting ceased as the speed reduced through
110 knots. The pilot flew the aircraft back to the
strip about a kilometre away and landed safely.
Inspection revealed that the elevator trim tab
actuating horn had separated from the tab,
tearing out a ten centimetre by seven centimetre
piece of the tab's lower skin around the horn
attachment point. This a llowed the elevator tab to
flutter , causing the violent buffet. T he pilot's
action in reducing speed below the flutter
threshold enabled the flight to be completed
safely.
Subsequent examination revealed that stones
thrown up by the main wheels had d ented the
lower skin of the tab. The dents acted as stress
raisers and the skin began to crack. The principal
skin crack grew in a chordwise direction above a
flute adjacent to the horn attachment . As the skin
crack developed horn loads were transferred to the
internal stiffener which also cracked. Finally the
reduced stiffness allowed elevator/ tab flutter to
occur and the section of skin around the horn
attachment tore out. The crack along the tab skin
flute h ad been propagating over a considerable
flight time.
The pilot acted correctly in reducing the air
sp eed as soon as the buffet was experienced and,
in fact, this was the only action that would have
stopped the flutter. The driving force for any
flutter is obtained by extracting energy from the
airflow. Obviously a high air speed will enable
more energy to be extracted and h ence increase
the severity of the flutter. Therefore when flutter
is experienced speed should be reduced
immediately (as much as is safely possible.) Use of
landing gear and flaps, power reduction and
trading speed for height should be employed to
achieve a rapid speed reduction. Should the flutter
threshold be below the stalling sp eed of the
aircraft, there is a good chance the aircraft will
becom e severely damaged or uncontrollable before
a landing can be m ade.
The lower surface of the elevator trim tab of the
Cessna Agwagon and other tailwheel aircraft is
close to the ground and may be rather awkward to
inspect. But rem ember, trouble does not come
only from the easily accessible areas of an aircraft.
•
The lower surface of the eleva tor trim tab is close to the ground and may be awkward to inspect.
22 I Aviation Safety Digest 112
A helicopter pilot engaged in survey operations
recently made a series of decisions which
culminated in engine failure d u e to fuel
exhaustion. In his report he made a number of
comments regarding the psychological pressures
whic h affected his decisions. An account of the
events contains a valuable lesson for us all.
The pilot lodged a flight plan by teleph one
from his temporary base in the Northern
Territory, nominating an ETD of 0830 hours local
and a SARTIME of 1830 hours. The flight plan
indicated that the aircraft would be en gaged on
survey operations all day. Last light was 1853
hours .
The Bell 206B departed for the survey area
which was centred some 50 nautical miles from
the base. A fuel dump of 200 litre drums of Avtur
was to be established a t this point. During th e
morning survey operations the pilot discovered
that th e fuel drums had not been delivered but
were still on the way by truck.
Fuel was obtained at anoth er point for the day's
operations. The last refuelling was during the
lunch break in the afternoon. Because of the
h eavy payload the fuel uplift was limited and the
aircraft was fuelled by reference to the fuel gauges
to give an estimated end urance of 150 minutes.
The pilot intended to operate back through the
survey area to his base without refuelling, as he
could n ot rely on the arrival of the truck carrying
the fuel. He anticipated 30 minutes flight time
back to the su rvey area and 40 minutes flight time
from there back to base. Ca rrying a reserve of 30
minutes, this allowed 50 minutes fo r operation in
th e survey area.
Towards the en d of that 50 minute period the
pilot realized tha t h e would not complete the task
and decided to extend the time he had allocated
for the survey. The extension of time m ean t a
reduction in reserves to less than 30 minutes. The
pilot accepted this and decided to rely on his
experience on this type of helicopter to cut the
reserve to between 10 and 15 m inutes . Although
he had some 500 hours experience on the Bell
206B, h e had only flown this particula r aircraft
for a few hours. During previous employment in
cattle mustering op erations, the pilot had
frequently operated his helicopter with reserves less
than 30 minutes and as low as 10 m inu tes. In
those operations he h ad been working close to his
fuel supply and had been very familiar with his
machine and its fuel gau ge.
On departure from the last field landing point
the pilot estimated the remaining endurance as 50
minutes, and the time interval for the 57 n autical
mile flight back to b ase as 40 minutes allowing for
a 10 knot headwind. He passed a departure
message to Flight Service with an ETA for the
base. The track passed close to the point where
the fuel dump was to be established so the pilot
diverted to overfly the site. He saw that the fuel
drums had now been delivered but gave little
consideration to landing for fuel to provide a safe
reserve. He felt he had made a mental
commitment when he advised the FSU of his
estimate, and felt it was not worth the trouble of
landing and spending about 30 minutes refuelling
from drums when th e aircraft could be refuelled
b y tanker at the base. It would also have been
necessary to remove quite an amount of
equipment from the helicopter to gain access to
the hand pump.
The pilot realised that the headwind was
stronger than he h ad allowed for and shortly after
passing the fuel dump site he had second thoughts
about his decision to proceed. However, he
decided that he would look foolish and indecisive
to his passengers if he turned back. The three
persons on the aircr aft were all tired after a long
and hot day in the field and there was still all the
trouble associated with refuelling from th e drums.
The flight continued .
Some 10 nautical miles from the destination the
p ilot became alarmed about the dwindling
reserves. Although he was over terrain suitable for
landing, and completely accessible for road
transport, he persisted with the flight knowing he
was dan gerously low on fuel. There was no low
fuel quantity light in the aircraf t, but the fuel
tank contained two pumps. The pressure warning
light of one of these began to flicker about seven
miles from th e destination. The pilot believed he
had 20 litres of fuel remaining. On final approach
the pressure dropped to zero and the engine
failed. The pilot was able to effect a run-on
autorotation onto the grass within th e aerodrome
boundary.
To quote the pilot's own words ' . .. the
incident was the culmination of my own
misjudgement, stupidity, inflexibility and
n egligen ce. I was too inflexible to change m y plan
even when it becam e patently obvious to m e that
m y decision to continue was wrong.' In letting his
judgement be influenced b y the extraneous fac tors
covered in this account , the pilot neglected the
p rima ry responsib ility involved in oper ational
decisions - the safety of passengers, aircraft and
pilot. He is, however, to be complimented on one
decision he m ade - to submit a full and frank
account of the incid en t and the circumstances
which led to it. Hopefully others will benefit from
th e lesson which this pilot lea rned the h ard way e
Aviation Safety Digest 112 I 23
�Induction icing
Every year, accident and incident records contain a number of occurrences in which induction icing
was considered to be the probable cause of engine power loss. In recent years much has been
written on the subject of induction icing, (refer Aviation Safety Digest 103, 106, 108) and Owner's
Handbooks and Operations Manuals contain appropriate advice and warnings. Yet even experienced
pilots still fall victim to this insidious phenomenon.
Aviation Safety Digest 108 lift-out chart). The
formation of ice at low or idle power would then
almost be assured.
Most owner's handbooks and operations
manuals warn against prolonged engine operation
on the ground with alternate or hot air selected as the air source is unfiltered. However, during
run-up (and in icing conditions immediately
before take-off) hot air must be applied for
sufficient time to ensure tha t any ice t hat may
have formed is removed. The technique will vary
with different aircraft types so check your owner's
handbook for the correct procedure for your
aircraft. Generally, application of hot air will
cause an RPM drop. If no ice is present the RPM
will remain steady at the lower figure. If ice is
present the RPM will initially decrease, then
increase as the ice is removed, and stabilize at a
h igher reading. The RPM will then incre$lse
further when cold air is again selected. This is a
worthwhile check following any prolonged period
of operation on the ground in possible icing
conditions. Make it your habit to ch eck for the
presence of ice as well as checking the
serviceability of the carburettor hot air system e
D
SERIOUS ICING - ANY POWER
D
MODERATE IC ING - CRUISE POWER OR
SERIOUS ICING - DESCENT POWER
H> I SERIOUS
D
ICING - DESCENT POWER
90
LIGHT ICING - CRUISE OR
OESC ENT POWER
80
70
RELATIVE
60
50
After a one hour delay due to fog the pilot started
the engine and prepared for take-off with three
passengers in his Cessna RlS2. By then most of
the fog had cleared; only small patches remained
in the gullies and valleys around the strip . The
temperature was sec with a relative humidity of
about 93 per cent. The pilot completed an engine
run-up , which included a check on the operation
of the carburettor hot air system, but he did not
specifically check for the presence of induction ice.
After completing the before-take-off checks the
pilot closed the throttle and got out of the aircraft
to remove condensation that had formed on the
outside of the windshield . This completed, he
strapped in, re-checked hatches and harnesses,
then taxied a short distance to the strip and
started the take-off roll.
Acceleration appeared sluggish to the pilot so he
checked that the hand brake was off. The
airspeed had increased to about 45 knots half-way
along the strip and the aircraft just got airborne
24 I Aviation Safety Digest 112
but would not accelerate any further. At this stage
the pilot started a shallow tum to avoid some trees
at the end of the strip and to take advantage of
low ground to the left, but the aircraft settled
back on to the strip . The pilot abandoned the
take-off and closed the throttle, but he was unable
to stop the left turn and the aircraft ran off the
side of the strip. It passed through two fences and
nosed over after encountering soft ground.
The pilot and passengers climbed out of the
inverted wreckage uninjured but the aircraft was
destroyed.
The investigation did not reveal any m echanical
defect in the engine or airframe to explain the
lack of performance; but atmospheric conditions
at the time of the accident were certainly
conducive to the formation of induction icing.
With a dry bulb temperature of sec and a
relative humidity of about 93 per cent, the
probability of serious induction ice formation
would be high at any power setting. (Refer to
HUM IDITY
O/o
40
30
20
l----+--- --r--10
0
5
10
DRY BULB TEMPERATURE
15
oc
20
Aviation Safety Digest 112 I 25
�More on unlocked seats
Aviation Safety D z'gest No. 111 /1980 contained an
article titled 'Unlocked sea t - loss of control
during ground m an oeu vre' . T hat article prompted
a number of pilots to relate airborne experiences
in which the seat unlocked a nd moved rea rwar ds
a t a critical stage of flight . One of those incidents
is described in the following reader contribution:
'The article " Unlocked seat" (Avz"atz"on Safety
Dz'gest ! 11 I 1980) broug ht b ack to m e frightening
memones .
'On en tering a Piper Ch erokee 140E for a solo
flight I a djusted the seat and thought it h ad
locked. All ch ecks were norm a l an d I took off.
Shortly after leaving the ground the seat suddenly
shot b ack. The nose immediately flew up a nd I
h ad to push with all m y strength on the control
column to p revent the aircraft stalling. Any
attempt to let go of the control column in order to
ad just the seat would h ave been fa tal , so I held on
and attempted to gain height. A b it higher up I
m ade a grab at the trim control while holding on
with on e h a nd an d, a fter several attempts,
m an aged to wind it d own so th at the strain cam e
off the control column. I was then able to let go
m om en tarily while, with one h and on the
26 I Aviation Safety Digest 112
d ashboard and the oth er on the seat lock, I got
the seat forwa rd and locked.
'Fortunately for m e I have long arm s . If the
inciden t h ad h ap pen ed to som eon e shorter a stall
m ay well h ave been unavoida ble . Cou ld this b e
the explan ation of th e accident in which on e read s
"shortly after take-off the plane was seen to
assume a steep nose up a ttitude followed by a dive
to the ground"?
' I n ow ch eck the sea t lock carefully on entering
a nd again at t he "controls free movemen t, ha tch es
secured" st age of the p re-take-off check.'
Investiga tion of an accident in the United States
recently d isclosed very similar circu mstan ces, but
in this case the results were fa tal. The following
account is ad apted from an NTSB Safety
R ecommendation on th is subject.
'A Cessn a Model l 72K crash ed during take-off.
T he pilot, a commercial fligh t instructor an d the
only occupan t of the aircraft, was killed .
According to witnesses, th e a ircraft pitched up to
a steep n ose high attitu de, about 60 or 70 degrees,
an d th e sound of en gine power reduced abruptly
from take-off power to idle. T he aircraft then
p itch ed d own a nd rotated about 160 degrees to
the left before crashing on the edge of the asphalt
runway.
'In vestigation revealed that the pilot's seat was
not locked and had slid rearward on the seat rails
d uring lift-off. Acqu aintances of the pilot stated
th at she flew the aircraft with her seat in the full
forward position. Because of her relatively short
stature she could not reach the throttle or rudder
p ed als, nor could she fully manipulate the control
wheel, with her seat in its rearmost position.
Conseq uently, once the seat slid aft, she was not
able to maintain control or regain control when
the pitch angle increased abruptly. The pitch up
of the aircraft to a steep nose h igh attitude and
the reduction in power would be the expected
con sequen ces of th e pilot's holding on to the
control column an d the throttle as her seat slid
aft.
'If the p ilot h ad attempted to position and lock
her seat in the full forward position in the
aircraft, the left front corner of the seat would
have con tacted and wedged against the door
jam b. T his interference, which is typical in this
aircraft m odel, can prevent the seat locking pins
from re aching th e forwardmost locking holes.
More impor tantly, th e wedging of the seat can
lead the pilot to believe that the seat is locked
when, in fact , the locking pins are actually
positioned between locking holes. Any subsequent
forces on the seat , such as those occurring during
take-off or landing, can cause the seat to release
abruptly and slide aft.'
T he pilot's operating handbooks for some popular
aircraft types inclu de the pilot's check of th e
adjustment an d locking of seats, belts and
shoulder h arnesses in the 'before starting engine'
checklist but n ot in th e take-off checklist. Others
do not include a check of the seat itself,
m en tioning on ly seat belts an d harness. Because
som e p ilots may fin d it necessary to readjust the
seat b efore take-off or in flight a check to ensu re
that front seats, belts and harn esses are adjusted
a n d locked sh ould be included in the 'before takeoff and 'before landing' checklists . The security of
the seat sh ould be tested with firm back p ressure
after checking th at the adjusting mechanism is in
the lock position .
W hile not a p ar t of a standa rd before-flight
inspection , a look under the seat once in a while is
a good practice, noting how the mech anism works
and wh ether it all ap pears to be in good
con dition . In most of today's light aircraft, floor
moun ted tracks are used in the adjustm ent of the
front seats, wh ich m ove forward and back on
rollers b racketed to the seat. T he seat is stopped
in the desired position by a locking device linked
to a bar or h an dle for use b y the pilot in releasin g
or locking th e seat in place. Most seats are locked
by p ins which slip down into h oles in the track,
althou gh a few use other devices su ch as clamps or
'shoes' . A security stop at the end of the rails
prevents the rollers from overru nning the tracks.
T h e adjustment m echanism is usually
sp ringloaded, so th at when the handle is released
the pins drop automatically into the locking slot.
However, in some cases there is no spring and the
pins must be manually positioned or the seat will
slide under pressure.
A rental or club aircraft, flown by pilots of
varying size , will have its front seats shunted back
and for th frequently, subjecting the movable
mechanism to considerable wear and occ~sionally
abuse by an impatient person. This may lead to
the end stops becoming weak and susceptible to
overriding, or to the intermediate stops becoming
enlarged and prone to slippage. For these reasons,
a periodic check of the seat adjustment
mechanism is included in the maintenance
requirements. This inspection should include the
following:
• The metal framework of the seat, particularly
the joints.
• The rollers and roller brackets - check for
proper alignment and wear .
• The locking mechanism , including the actuating
arm, linkage and locking pins - make sure the
release spring, if there is one , is intact, and the
action is positive.
• The floor-mounted rails - make certain they
are tight to the floor and tracking true; the rail
stops should be clear and not distorted, and the
end stops solid.
While you have your nose down on the floor,
this is a good time to remove any foreign or loose
objects hidden under the seat. Coins, combs, keys
and other abandoned miscellany take a malicious
delight in jamming vital mechanisms at the worst
possible time •
Opposite page and above.
Typical light aircraft seat adjustment mechanisms. In both
examples the seat is unlocked.
Aviation Safety Digest 112 I 27
�Loose foreign objects
Fuel specific gravity
The article beginning on page 14, which describes the circumstances surrounding an accident in
which an Aero Commander crashed following fuel exhaustion, raises some points concerning the
effect of fuel specific gravity variations on range and endurance performance. This article briefly
discusses the significance of fuel specific gravity as it applies to aviation gasoline, and compares
practical range and endurance performance with published data.
T he volume of fuel consumed during a given
flight, i. e. for a given amount of work performed
by the engine, depends ultimately on the net heat
of combustion per unit volume of the fuel. That
property varies with the specific gravity. P ut
simply, if the specific gravity is low a greater
volume of fuel will be required to perform a given
amount of work.
Specific gravity was, at one time, the only
measure of the energy potential of aviation fuel. It
still appears in specifications for aviation turbine
fuel but not in respect of aviation gasoline,
although the specific gravities found in practice
are effectively limited by h eat value specifications.
The specific gravity of AVGAS 100 and lOOLL
varies typically between about 0. 69 and 0. 73 at 15
degrees Celsius. Temperature variations from
standard introduce further variations, and it is the
combined effect of these two factors which will be
examined.
For all practical purposes performance varies
directly with fuel specific gravity. For example, a
fuel of specific gravity 0.69 will give about four
per cent less range a nd endurance than the same
volume of fuel at specific gravity 0. 72.
Most a ircraft operating handbooks assume a
specific gravity of 0. 72, usually expressed as a
density (eg six pounds per US gallon) for the
presentation of range and endurance data. A
problem obviously arises if flight planning is
conducted with reference to that data and the
actual specific gravity of the fuel loaded is
significantly lower than 0. 72. Normally the effect
is relatively insignificant - a performance penalty
of three to four per cent, for example, over a
short flight m ay go unnoticed. But when the
penalty extends over a lon g flight, or when high
fuel temperatures introduce large reductions in
fuel specific gravity, the effect may seriously erode
the calculated endurance. A six per cent
reduction, for example, would equate to a penalty
of almost 22 minutes for a flight requiring an
endurance of six hours. This is nearly half of the
statutory fixed reserve. While th e conditions
required to achieve such a penalty may not be
typical of normal operating conditions, they can
occur.
T he following figure illustrates the effect of
temperature on performance. By entering the
graph wi th ambient temperature and the specific
gravity at standard temperature (or with a known
specific gravity at ambient temperature) the effect
on performance calculations made against an
assumed specific gravity of 0 . 72 can be readily
extracted. As the example shows, a specific gravity
of 0.69 at 15 degrees Celsius will drop to a little
under 0.68 at 30 degrees, incurring a total penalty
of some six per cent against performance figures
extracted from published data.
Specific gravity readings for each fuel batch are
recorded on the Release Note held by the airport
authority or agent to whom the fuel company
delivers the fuel. That information is normally
available to pilots, but there may be times when it
is not. In those instances the safe thing to do is
assume the normal figure (0. 72) for loading
purposes but take account of a possibly lower
figure in estimating endurance .
Although pilots will rarely have the means a t
their disposal to determine fuel temperature, an
informed estimate can usually be made. Fuel
stored underground will probably be close to
standard temperatu re , while that stored above
ground, drum stock for example, may reach or
even exceed ambient temperature e
The pilot of a Cessna l 52A was engaged in a
period of solo aerobatic flying when the ailerons
jammed in the right wing down position during
recovery from a slow roll. By appl yi ng a large
amount of force the pilot was able to centralise
the ailerons and level the wings. She then returned
to base from the training area and made a safe
landing in gusting wind conditions with the
ailerons still unusable.
Subsequent inspection of the aircraft by
maintenance engineers revealed that the
malfunction had been caused b y a drilled-off rivet
tail being jammed between the aileron dri ve
sprocket and chain on the pilot's control wheel.
T he aircraft had flown only 20 hours since new,
and radio equipment had been installed recently .
It could not be established if the rivet had been
drilled out during manufacture or the radio
installation. Thorough cleaning of the aircraft
floor produced the assortmen t of foreign objects
d isplayed in the ph otograph.
Loose foreign objects are a potential hazard in
any a ircraft, but the possibility of interference
occurring is much greater in aircraft involved in
aerobatics. The unusual attitudes, negative 'g' a nd
sudden manoeuvres of aerobatic flying will
dislodge objects from their resting place when
n ormal flight would not necessarily do so. The
maintenance organisation which recovered the
objects from this a ircraft also advised that they
frequently found p lastic fasteners on t he cabin
floor or under the instrument panel of aircraft.
These fasteners are used to attach inspection
panels in th e cabin . They fit into a grommet and
are held by plastic legs . These legs are very brittle
and fail frequently , thus allowing the fastener to
fall out.
Aircraft lifting procedures
-so
-40 -30 -20 -10
FUEL TEMPERATURE (°C)
28 I Aviation Safety Digest 112
0
10
20
30
40
so
At page 19 of A vz'ation Safety Dig est 111 I 1980 we
published a photograph of a Beech A36 Bonanza
being lifted after a wheels-up landing.
It sh ould be pointed out that the lifting
procedure used was incorrect and could have
inflicted additional damage to the aircraft. The
photograph shows the aircraft being lifted by the
propeller and what appears to be a belly sling aft
of the wing trailing edge . Such a configuration
could subject the engine mounts and associated
structure to loads for which they were not
designed.
The Beech 36 Shop Manu al describes two
methods of lifting the a ircraft. In the first , a sling
is attached to the upper fo r ward wing attachment
bolts on th e main spar, with a strap attached to
The responsibility for cle anliness of the a ircr aft
cockpit and cabin lies b oth with pilots a nd
m a inten ance staff. The latter should make cer t ain
th at n o tools or sm a ll items such as rivets or
wash ers remain in the airc raft after service has
been completed . Pilots should conscientiously
check the aircraft internally for foreign objects
during the pre-flight inspection. They should also
be aware of the possibility of themselves or
p assengers bringing pebbles into the aircraft on the
soles of sh oes . The pre- fl igh t inspec tion should be
eve n more scrupulous following an y maintenance
or prior to a period of fl ying involving greater
m anoeu vring than nor mal •
the propeller. In the second, the lifting sling is
attached to the main spar carry through in the
cabin and a line is attached to the engine hoist
fitting . In both methods the lifting load is carried
by the main spar with the propeller or engine
hoist fitting carrying only light levelling loads.
Personnel involved in the recovery of aircraft
after accidents must guard against inflicting
secondary damage , particularly through the
application of inappropriate procedures. The
danger lies not only in the likelihood of incurring
additional repair costs, but also in the chance of
the d am age going undetected with possible later
catastrophic results.
In this p a rt icula r case , the aircraft and engine
underwent extensive inspection, repairs and
rebuild following the a ccident and were returned
to an airworthy condition •
Aviation Safety Digest 112 I 29
�PILOT BIRD STRIKE/ HAZARD REPORT
Normally th is re port should be mai l ed to the Di rector in the Reg ion, Atte ntion ASSU, 1n which the i ncident occurred.
If more convenien t it may be lodged with the O IC of any A TC o r Fligh t Service unit.
BIR D ST RI KE
D
B IRD NEAR- M ISS
D
~Transport
~Australia
BIRD CONC ENTRAT ION
D
AERODROM E NAME
OPERATOR
AIRCRAFT MAKE/ M ODE L
ENGIN E M A KE/ M ODEL
RUNWAY USED
AIRCR A FT REGISTRATION
LOCATION IF ENROUTE
DATE
HEIGHT AG L
LOCAL TIME
DAW N
D
DAY
D
DUSK
TYPE OF OP ERATI ON: airli ne
0
D
NIGHT
com mu ter
PHASE OF FLI GHT
D
D
SPEED IAS
charter
D
parked
fl ying tra ini ng
D
pv te/ business
D
ot he r:
SKY COND ITION
no cloud
t axi
some c loud
take off run
overcast
c limb
en rout e
In July 1978 the Department launched a bird
strike reporting and analysis system with an aim to
improving the collection and analysis of bird strike
data in this country. The system was introduced in
Aviation Safety Digest 102/ 1978 concurrent with
the release of the now familiar bird strike report
form. Since then, the quantity and quality of bird
strike reporting has markedly improved . For
example, between 1969 and 1977 the average
number of bird strikes reported each year was 276.
In 1979 the figure more than doubled to 571.
In May 1978 the system was presented to the
first ICAO Regional Workshop on Reducing Bird
Hazards to Aviation. Following this presentation,
an ICAO Working Group was formed to develop
an international bird strike data analysis system
based on the Australian model. The result was the
ICAO Bird Strike Information System (IBIS) ,
which is now ready to accept world-wide bird
strike data.
IBIS will facilitate direct international
comparison of many aspects of the bird strike
hazard. This wil1, among other advantages, enable
the effectiveness of various bird hazard reduction
techniques to be evaluated and assist in a study of
the vulnerability of particular aircraft engines and
airframes to bird strike damage.
To provide the d esired information for input to
IBIS, and to apply lessons learned since 197 8, the
Australian bird strike report form has been
revised. The new form (shown opposite) has been
designed to be easily and rapidly completed. It is
single-sided and can be used to report a bird
hazard as well as a bird strike. The form embodies
a number of minor changes to the content and
presentation of the informa tion required. For
example, the height at which the incident
occurred should now be reported with reference to
ground level instead of sea level as on the previous
30 I Aviation Safety Digest 112
form. Thus, a bird strike or hazard encountered
during the take-off run or landing roll would be a t
zero feet AGL.
The new forms are available at flight briefing
offices . Completed forms may be lodged at an y
Airways Operations Unit or sent to the Director
(Attention ASSU) of the Region in which the
incident occurred.
To be effective, the Bird Strike/ Hazard Report
must provide all known data relating to the
incident. Information that, at the time , may seem
insignificant or irrelevant m ay, in combination
with other reports, reveal important information
on many aspects of the problem, including the
behaviour, migra tory habits and h abitat of b irds;
the effectiveness of bird dispersal and hazard
reduction techniques; and the ability of aircraft
structures to withstand damage , to name a few.
All aircraft damage, however insignificant, should
be reported. For example, a small dent in the
aircraft skin should be reported, at least as minor
damage. Other important information re quired is
the height at which the incident occurred and the
IAS at the time. Unfortunately, that informa tion
was often not reported on the old form.
The reduction of bird hazards will result only
from a continued co-operative effort on the part
of everyone involved in avia tion, including pilots,
aerodrome groundstaff, A TC and Flight Service
personnel, aerodrome licensees and planners , and
the aviation industry in general. A wide data-base
is required to permit identification of th~
_hazards, develop countermeasures, and assess the
effectiveness of hazard reduction methods.
Without accura te a nd compreh ensive data the
bird strike hazard reduction programme cannot b e
effective. So, ple ase, report all bird strikes and
h azards - n ot just those from which damage
results e
PR ECIPITATION
fo g
desc ent
rain
approac h
snow
§
§
land ing roll
PART(S) OF AIRCRAFT
STRUCK
DAM A GED
radome
BIRD SPECIES
NUM BER OF BIRDS
SEEN
w inds hield
nose (exc lu ding above)
2 - 10
eng ine no. 1
1 1 -1 0 0
engine no. 2
mo re
engine no. 3
engine no. 4
SIZE OF BI RD
STR UCK
~~
small
propelle r
medium
wi ng/ rot or
larg e
§
f uselage
landing ge ar
PILOT W ARNED OF BIRDS
ta il
yes
no
lights
other (specify)
INJ URIES TO PERSONS
yes
no
EFFECT ON FLIGHT
none
aborted take-off
B
B
A IRCRA FT OUT OF SE RV ICE TIME ...................... .................... ... ....
precautionary landing
ESTIMATED COST OF REPAI RS ............................................. .. .. ....
engines sh utdown
ot h er (spec ify)
ESTIMATED LOSS OF REVENUE ................................................ .. ..
DESCRI PTION OF DAMAGE. INJUR IES. OTH ER INFORMATION
PILOT'S NAM E _ _ _ _ __ _ __ _ __ _ _ _ __ _ _ _ _ _ __ _ _ __ _ _ _ _ _ _ __ __ _
D .o.T . 2388 (Rev. 11 / 80)
THIS INFORMATION IS REQUIRED FOR AVIATION SAFETY
A viation Safety Digest 112 I 31
�
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Aviation Safety Digest, number 112 (1981)
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112
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1981
-
https://collections.heritageoftheair.org.au/files/original/c2426c50eba2384779666294f3e918b4
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J
AUSTRALIA
ATr'a'nsport
C-
~Australia
~J.)).>>)-)':{;:;(«<(((C
•
1 es
•
Courtesy of Pilot Press, copyright drawing.
111/1980
�'.
ATransport
Ground effect
\4.t]Australia
?!
--- ---
Contents
3
Ground effect
4
"Pilot continued VFR flight into
adverse weather ... "
7
Churchill Fellowships
8
Seat belt adjustment problem
9
Dirt strips: excessive brake wear
Aviation Safety Digest is prepared in the Air Safety Investigation
Branch and published for the Department of Transport through the
Australian Government Publishing Service, in pursuance of Regulation 283 of the Air Navigation Regulations. It is distributed by the
Department free of charge to Australian licence holders {except
student pilots), registered aircraft owners and certain other persons
and organisations having a vested operational interest in Australian
civil aviation.
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries and notifications of change of address should be directed to:
The Assistant Director {Sales and Distribution) ,
Australian Government Publishing Service,
P.O. Box 84, Canberra, ACT 2600.
Subscriptions may also be lodged with AGPS Bookshops in all capital
cilles.
1O Vision 4 - visual illusions
14
Systems knowledge: the landing gear
20
Fuel starvation in Hughes 500 helicopters:
missing fuel tank vent fairing
22
From the incident files
Lake LA-4 nose gear retraction.
23
Do you raise the flaps during the
landing roll? Why?
26
Unlocked seat - loss of control during
ground manoeuvring
27
Flight through restricted areas
28
Flight safety - a team effort
29
Review of free distribution list
31
Boeing 767-200 cover illustration
-
cutaway key
Readers on the free list experiencing problems with distribution should
write to:
The Publications Distribution Officer,
Department of Transport,
P.O. Box 18390, Melbourne, Vic. 3001 .
Reader contributions and correspondence on articles should be
addressed to:
The Assistant Secretary (Air Safety Investigation),
Department of Transport,
P.O. Box 18390,
Melbourne, Vic. 3001.
IL is possible Lo ll y an a ircraft a f"ew feet above the
ground al ;rn a irspeed lowe r than that required Lo
susta in level fligh t at an a ltitude only slight.l y
higher. This is the 1-csult o f" a phenome no n called
ground effect - apparentl y beuer known th a n
understood by many pilots. In te rms as
non-technica l as possible, we will here d efine a nd
discuss the ma.ior proble ms associated with this
ra the r com plex subject.
What is ground effect?
It is no t possible , nor would it serve our purpose, Lo
attempt in the sr acc ava ilable a discussion of the
aerod ynamics o ground effect. I 11 simple terms, it
is the 1·esu lt of" interaction between wing airflow
patterns a nd the surface of th e ca rrJ1 . All ai rfoils
such as win gs, rotor blades, e tc. produce tip vonices
a nd exh ibit distinct airstrea m downw<ish
characte ristics whe n developin g li{.t. T he vertica l
compo nents of such tip vo rtices and clownwash
velocities a rc progressively red uced as the airroil
nea rs th e surface , a nd al to uchdown a rc almost
complete!)' cancelled by surface interfne11ce. This
alteration in a irflow pattern decreases induced drag
{the drag produced by lift). The closer the a irfoil Lo
the surface, the g reater the red uction. Induced
drag, at a he ight of approxima tel y one-Lelllh of a
win g spa n above the surface, ma y be 47 per cent
less tha n whe n th e aircraft is operating out of
ground e ffect. It is this d ecrease in drag which
explains basic ae roplane reactions when in ground
e ffect .
© Commonwealth of Australia 1980. The contents of this publication
may not be reproduced in whole or in part, without the written authority
of the Department of Transport. Where material is indicated to be
extracted from or based on another publication, the authority of the
originator should be sought. The views expressed in articles reproduced from other sources are not necessarily those of the Department.
RM77/30217{7) Cat. No. 80 3114 X
Printed by Ruskin Press, 552-566 Victoria Street, North Melbourne,
Victoria.
How does a reduction in induced drag affect
performance?
To the pilot, the reduction in drag means increased
performance. T hat is, lif"t will increase with no
lllcrease i11 angle o f a llack , or th e sa me lift c;rn be
obtained al a s ma ller angle of a llack. This ca n be
useful since it a llows th e' pilot to either decrease
angle of auack / powe r to main tai n level flight , o r as
on'most la ndings, to maintain wing lift while
1·educing powe~· . A word o f ca u tion is in order,
howeve r. A f"ull stall landin g will rccJuire seve ra l
more degrees of up elevato r cle flecuo11 than would
a full sra)I when done free of ground e ffect. This is
true beca use <>Tound effect usually changes
horizo n tal taif effccrjvencss in a ircraft ot
co11ven tional con lig u ration .
What major problems can be caused by ground
effect?
Floatin g during la nding is, in part, a result o f
ground effect. A n aircraft will continue to remain
a irborne just above th e surface at a speed which
would have produ ced an immediate stall had the
aeroplane been a bit highe r. The refore, a pilot may
run out of bot.11 run way and options if he carries
excess speed in the ap proach , or docs nor allow for
at least a sma ll ma rgin of float afte r the flare f"rom
a normal approach .
Another, a nd perhaps mo re serious problem , can
d evelop during take-off a nd climb out, especiall y
whe n usin g a rnnwa y of ma1·gi n a l length . Deluded
into believ111g that he has cli~b-ou t capability simply
because he was able ro get in the a ir, a pilo t ma y
raise the gear the ins tant he is airborne or initiate
an immedia te clim b. For a few f"ect all ma y go well ,
but he ma y reall y have o nl )' margina l climb
performan ce even in grnund effect and , th erefore,
an acute need for add ed thrust as he begins LO
move out o f gro und e ffect. On m oving out of
ground effect, eve n if it only slig htl y increases the
cffeCLive ness of the eleva tors, the nose will usually
Le nd to pitch up. At the resultant high angle of
attack, the pilot finds he cannot climb, or even
wo rse, ma y begin to sink. Despera tely holding his
nose-high attitude in a futile effort LO gain altitude,
he steadil y mushes or stalls back Lo the runway or
into obstructions if no excess power is available to
correct rhe situation . Add high gross weight, hi gh
d ensity a ltitude a nd a bit of turoulence Lo this scene
a nd a n accident is even more likely.
Airspeed indicator unrelia bility 111 gro und effect
is a nother, tho u gh less critical problem. Usually it
will indicate slight! )' highe r as you leave a nd slightl y
lower as you e nte r ground effect.
Ju st remember, ground effect is a lways there; it
ma y prolong the gfidc o r permit a n a ircra ft to get
a i1-borne witl1 insunicicnt rower to sustain flig ht
outside the area of grounc effect. If this occurs tl1C
pilot must allow the airplane to accelerate while still
111 ground e ffect, before attempting to continue the
climb. Panic a llcmpts to fo rce a climb can only
ma ke lift / clim b problems worse
e
(Ar/1111m•INlg1•1111•11/ /o 1/11• U.S. F('(/nal Aviali1111 1lr/111i11i.1/mli1111for VFR
Pi/11/ F.\·a11HJ-gra111 No. 4 7)
Up to what altitude can ground effect be
detected?
A pilot is unlike ly to detect ground e!Tect if his
h eight ab~>ve the s u1:face exceeds th e aircraft's wing
spa n . ln fact, th e re 1s a pprecia ble ground effect
on ly if h eight is less than half th e wing span. At t.11is
or lower altitudes, ground effect is qwte
prono unced .
2 I Aviation Safety Digest 111
Aviation Safety Digest 111 I 3
�"Pilot continued VFR flight into
adverse weather . . ."
The following reports on two more weather related accidents highlight the type of occurrence which
continues to cause the greatest loss of life in Australian aviation accidents.
The pilot h ad bought a Cessna 172 aboUL four
months prior LO Lhe accide nL, a rLe r qualifying ro r
his PrivaLe Pilot Licence. On the day of the accident
he intended LO Cl y th e aircraft from Woomera to
Pa rafie ld with a refuellin g stop at Port Pirie. After
arrival at Paraficld he was Lo meet his wife and
daughter in Ade laide a nd the n e<ll ch a n RPT flight
interstate.
At 11 53 ho urs local he Lelephoned the Parafielcl
brie fin g oflice and obtained the ap propriate
me teorological forecasts for th e fli gh t. T he forecasts
inclicaLed Lh aL, in th e area covering the
Woornera-Pon Augusta secLor , th ere would be
scattered LO broke n stratus, strato-cumulus and
cumulus cloud, and visibility wou ld generall y be 40
kilome tres, redu cing to 10 kilometres in rain
sh owers and 4000 metres in drizzle. The forecast
for the area south of Port Augu sta was similar.
A short while late r the pilo1 agai n called the
briefing offi ce a nd submitted a private category.
VER flight p la n . H e was advised that Paraficlcl was
closed to VFR operations and tha1 30 minutes
holdin g was required beca use of weath er. The pilot
advised that h e would recheck the Pa rafield weathe r
before d eparting Port Pirie .
The aircra f'l de pa rted Woom era a l 1255 hours
with the pilot and a friend o n boa rd a nd , eight
minuLes late r , the pilot establish ed HF radio
communications with Adelaide Flight Se rvice Unit.
Al 1344 h ours he made an 'all sta tions' call
indicating that h e was live miles north west of Port
Augusta a nd overfl ying below 5000 feel. Sh ortl y
a fter wa rds he passed his Port Augusta position to
Adelaide with an estirnaLe fo r Po rt Pirie at 141 8
ho urs. H e the n transferred to the Adelaide FSU
VHF freque ncy a nd esLablished communications.
At about th is time at the Port Aug usta aerodrome
there was overcast stra to-cumulus cloud, base
approxima tel y 2000 feet, and to the south there was
a line of drizzle a nd associated stratus cloud lying
east/ west a nd moving north. The hills Lo th e south
of the aerodrome we re covered in mist and stratus
cloud. Simila r we~th er conditions were observed by
two persons fishing from a boat situated a l Lhe h ead
of Spencer Gu lf some six nauti cal miles south of
Port Augusta. The fishe r me n heard a single-engine
aircraft approach from the north a nd intermittently
observed it thro ugh breaks in th e low overcast. 1L
made several turns in thei r vicinity and then headed
towards the hills to Lhe west. T h e engine noise the n
increased a nd they finall y observed what appeared
to be the wing of an aircraft bounce into the air
from the ground. The engine noise stopped
suddenly at Lhat Lime.
At 1357 ho u rs the call sign of the aircraft was
h eard on the Adelaide FSU VHF frequency and the
voice was shrill and urge nt. Calls lo the aircraft did
4 I Aviation Safety Digest 111
not produce an y response a nd Search a nd Rescue
a lertin g was initiaLed. T he wreckage was located by
a searching a ircraft al 1550 hours.
Detailed examina tio n of the wreckage did nol
reveal evidence of any del"ccl 01· ma lfunction which
might ha ve con tributed w th e accidenl. The
da mage to the airua l"t , togeth er with g round impact
marks, indicated that th e a i1·craft s truck the ground
at h igh speed in a steep nose-dow n , right
wing-dow n atlitude , consistent with it being in a
sp iral dive.
~
The pilot h ad flo wn a tota l of 120 h o urs, of
which 65 had been on this type of a ircraft. He h ad
flown 22 hours in the last three mo nths e
zero but quite d ea r lO th e north '. No further
communications were received from the a ircraft.
When the p iloL d id not noLify his arriva l by the
nomina ted Sa rtime, Search a nd Rescue alertin g
acLion was initiated.
'
. The_ aircraft wreck~ge was located by searchin g
a ircraft on the fol lowmg da y. It was situathl on tl1e
dense ly timbered, eastern slopes of a mountain
ra nge, about 4~0 fee~ be low the top o f' th e range
During the morning, a Beech Sierra had been flown and three naunca l miles north from the summit of
f'ro111 a property near Trangie, NS W, to Ban kstown
Moun t H o rrible. This locatio n is north cast of th e
Airport, with the owne r / pilot and his cousin on
flight pla nned track.
boa rd . Afte r lunch , Lhe pilot au.ended the
Al th e tim e of initia l impact with trees, Lh e
Ba nkstown bric rin g office and o btain ed the
a i.rcraft was o n a south westerl y headin g. in level
appropriate 1neteoro logica l in fo rm ation for the
~ 1ght _and_ban ked abou l 15 d egrees to th e right.
return flig h1. He submitted a VFR flight plan which Exam 1nauon of the wreckage was limited by the
nomina ted a Sartime of 1900 hours local time,
exten t o r destru ctio n arising from impact damage
trackin g via Katoomba then d irect to his
and su bseq ue nt fi 1-c. No evidence was found of any
d estination, below 5000 feet.
defect o r malfuncrio n which may have co ntributed
lo the accide nt.
T he rorecasts indicated occasional thunde rs1o rms
A_meteorological post-a na lysis ind icated that,
in the area, broke n to scauered stratus and cumulus
d urin g the ar·re rnoon 0 11 which th e accide nt
cloud , a nd visibility d eterio ra ting in rain and
occurred , a n ac ti ve cold rro nl 111oved eastwa rd over
thunde rsto rms. From th e brie fin g office, th e
the planned track or the aircra ft be twee n
thunde rstorm s over the ran ges were visible and
we re drawn to the attention of th e p ilot br th e dut y We ll i~1gto n a1.1d Ka toornba. The r·ron t passed Moun t
Ho.rnblc d nnng the hour irnrned ia1e ly prior to the
Flight Service brie fing officer.
The a ircraft d epaned at 1544 hours and the pilot accident a nd, in post-frontal preci"pilatio n, there
wo uld have been areas of cloud down to g round
establish ed rad io com111unica 1i ons wi th Sydney
level. Ground witness evidence confirm ed the
Flight Service Unit. He subsequ ently reported over
passage or· lhe !"rou t a nd the presence or extensive
Ka too mba a t 1606 hours, be low 5000 feet and
low. cloud _e 11"e lopin g the hig h groun d nea r the
estimating abea m Hathurst at 1632 hours. At 16 16
accident site.
hours he cha nged to the approp riat e FSU
Thi s pilot ll'as not inex perienced, havin g flown a
frequeucr a nd established satisfacrory
1otal o l 200 ho u rs, all of it on this ai rcra f"t but he
communications. A minu te la ter a broken
did no t hold a n instrumenr ra ting. Tu the 'last three
transm ission was received br 1he FSU , ap parentl y
months he had flow n about 30 ho urs e
from the Heech Sierra, ·... up to th ree five zero
Aviation Safety Digest 111 / 5
�}'ea,.
1971
1972
1973
197-t
1975
197!-i
1977
1978
1979
TOTAL
Total
2 18
179
219
n-+
190
2-13
221
2-19
2-+3
1996
A ccidm/.1
Fatal
1-t
20
15
17
12
19
19
27
19
Fataliti1'.1
162
:~ -1
·13
'.26
:~9
'2.7
53
·13
58
35
:i:-,x
Pilot rn11ti111u't! I' J·R Jlif!;/1t i11to
rull't'l".11' 1t'r'ath1'r ro11dilio11.1
,..atalitil'.\
Fatal
Total
7
22
n
-t
'.2
3
I :~
-t
10
5
18
ll
2
5
3
6
21
9
I !>
7
5
11
s
7
q
2
I
(it{
:18
6 I Aviation Safety Digest 111
!'light. This assessment will req 11i re a perceptio11 or
- the chance ur failure, and
- the consequence or failure.
I laving es tablished tltcsc, the pilots can then
a n swer the question, 'Is it worth it?'
Perhaps we should al l try rhe same techt)ique
e
TJ..I UN DEi<:STORi""S
OVER THE
MOUNTAINS!
I 17
Othe r delega1es ex pressed the 1·icll' that a lot or
pilots had d illi rn lty in 11ndersta11di11 g weat her
forecasts and in relating th ose lo recas ts ro the
conditio11s the y could expect to enco 11 nter a long
track. The s11!mcstcd c ure f'or the llrst p ar1 of' 1his
proble m ll'<IS a change in the presenta tion or
f'o1 ·cc;1sts. The forma l or are a lurecasts, in
particular. is c111Tenil~· being rCl'ic11·cd j o in t I>· b~· the
B11rea u o r .\l etcorology and the Lkparr111cn1 ol'
Trans port 10 ens11 re that pilots rcn:j\·c t hesc
forecas ts i11 the most logica l an d unclcrs ta n dable
l'o rm. T o 01·erco111e th e seco nd part or th e p roble111
re qui1-cs the pilot to o btai n i11s1 runi on in the 1norc
pracl ica l as peers or 111e teoro log~· rat her than j11st
lcan1i11 g c11oug-h to pass Dcpart111c111al licc11cc
examinations. Al'ter all i1 co11ld sa1·e >·our lire, so
p er ha p s th e cx1ra effort is worth i1.
Another problem 11·hicl1 \\'as di sci 1ssed al the
Sl'lllposium, but is not solcl>· relat ed ICl thi s t ~']JC' ol'
acc iclen1 . 11«1s th e p ress11re 11nder ll'hic h a pilot
o pe ra1 es once he rccci1Ts h is u111-cstrictccl licence.
The press 11res rcfrrrecl 10 are those 1d1ich ten d 10
i1npel him to complete 1l1c lli g ht , and the pro blem
appears to be co lll pou ndcd when passenge rs a re
carri ed. It is possible 1ha1 the t11·0 fatal acc idents
described earlier con1;-iined clcn1e111s of s uch
press 11 re. In t he Port J\ 11 gusra accident the pilo t 11«1s
1101 u11dc1· any a p pa rent p ress u re f'ro 111 his
passe11gcr, but he d id ha1e a11 Rl'T lli ght to catch
What does all this mean?
ll'ith his f'a mih· la ter in 1he da1·. In the ot her
At the Australian Symposiu m on Gen eral A1·iatio11
accident it 11·0.1ilcl a p pear that .the pilo t and hi s
Safrt>·· s pon sored b)· the Ro>·a l Aeronautical Socict~·
passc 11ger lta cl comple ted thei r business a nd h ad
and held a t the u ni vers it\' o r ;-..: Cl\" Soul h Wales in
nol plann ed an o\·crnight s tay in Snlne~-. l'crhaps
.\la1· J 980 , I here 11·as co n siderable di sc uss io 11 aboul
th e~· \\'ClT o\-crl ~ keen lo re turn home a nd gel 0 11
t hi; kind or \\'Cat her l·elated accicle11t.
1\'ith
the ir norma l h 11siness. v\' het her or not s11c h
Arising l'rorn th e discussion , del egates raised
factors \\'ere sig niricanl in 1he se 111·0 accidents 11111st
se 1·era l points 1\'hic h are worthy o f cons idera tio n by
n:m ain spec 11l <~ti1·c, but it is a ran thal pressu res or
ll1Cl1lbers or the indust n ". In pa rtic ular. it \\'<IS
this type do () ((.'I ll' rrn111 t ime lo lilllc and all pi lots
cla illle cl that the m ·e rage pri va te pilo1 does not ha1·e
~ho11ld think ca rc r11ll y before COl\lllle1ici11g a 11 y
a good understandin g or th e lirnitations 01· him se lf
lli<rlll
\\'it h all c lement or risk.
and hi s airc raft when faced wil h deteriorat ing
n
.
An01hc r de legate at the S)'t11posiu 111. rcprcsc nt lllg
weat h er, forecast or 11nl'orecas1. He is not likel y to
an oper a tor 11·i1 h a llect o r sin g le e n g ine Cessna~ in
re ally appreciate hi s distance rrom cloud and the
Pa pua ~C\\' c; uinca s po ke or t he potential cost or a
radius or rurn of his ai rc ral't a t cru isin g s pee d.
fatal accident. E1·e n ii' 1he pe rso n al tragedy aspects
T hc1·cl'o rc , he ma )' 11Tll l'i11d himselr in a sit11ation
arc put to o n e side ;111cl 0111~· the economic
\\'here h e e nte rs c loud whil e atte mptin g to avoid i1.
co11sequences or I he accide nt arc ro11s1dercd , I he
To ltcl p 01·e1-comc this problem it \\'as suggested
cost to the orga11 isa 1io11 co uld be as lti g h a s hair a
that pilo 1s s hould 1111clertake so me du a l in struct ion
million dollars. Liabil it )' pa )' lll Clll S to l'a n1ilies or
11·ith an in stTu mcnt rate d in s tructor who can
demon s trate to th c 111 s uch thin gs as judgi n g di stan ce d ecease d passe nge rs: lil'e ins u n 1ncc a nd ll'orkcrs
compe nsa ti on payments to rhe pilot 's ramil y:
rrom cloud , radius and r a te o r tur11 in vario 11s
partic ipa tion in Searc h a nd Resc ue and accide nt
co nfi g urarion s and what t he pilot could ex pect
i111-cs1iga tio11 : 1hc cos t ol' recruitin g, scree ning,
to cxperie 11cc ii' he did inadverte ntl y e n1 e 1· clo ud.
Notwith sta11cling that the preceding type o r accident
is the ca use or th e g reatest loss or life in A ust ralia11
avia tio11 . a misconception apparent } ~· exists among
pi lots 111'11 this is the most common t~· pe o f accide nl.
This conclusion had been reached because or I he
11urnber or report s or s uch a cc idc11t s pri1llcd in th t>
A1 1iatiu11 Sa/i'IY Digest a 11d the e 111phasis thcv had
been given.
As can be seen l'rom the acco 111pa11~· i11 g table. pilo ts
co ntinuin g V FR flig ht into ach·e rse \l'eather
co nditions is no1 a rn<uor cause ot' acciden1 s. In foci
or the I 99G accidents in the pe riod , there were only
68 whi c h were assig ned this factor. i.e .. only 3.-t per
r e nt 0 1· the total accidents. H o 11·e1·er, this categorv
o r accid e nt does resu lt in a 1·cn · hi g h ra1ali11· rate.
I 11 th e 38 fatal accidents recorded in 1hi s category. a
total of 117 li1·es \\'Crc lost. T hat is 32 .7 pe r cent or
a ll fatalities in A11s1ra li a n general a1·iation a cc ide n1 s.
or these 38 rata l accidents, 32 11·ere fl ow n b~·
pri1·ate lice 11sed pi lo1s a nd 35 11·ere in 1hc pri1·ate
class or o pe ration. Seasonall~·. 111ore th a n one third
or these acc idents occ urre d in autumn. 11·i1h 11·i11t e r ,
s ummer then s prin g being til e rel a li1·e o rd e r ol'
frequ e ncy. A breakclo1rn ol' pilots' ages. expe r ience
and ot he r !'actors s holl'ed no signillcant !re nds or
re la tions hips.
oric11 tatio11 traini1 1g, checking 0111 and establishing a
rcplace ntcnt pi lot, toge ther with the COS! of
obta ining and eq uippin g a replacement aircral't
cou ld eas il l' reach th is s un i.
In its saf'ety p rogram. the orga11isation was asking
i1 s p ilo ts ro assess th e risk ractor associa1ed \l'ith a
DURSTIN by Russ Day
(courtesy of Flight Crew magazine Spring 1980)
Churchill Fellowships
The Winston Clwrc hi ll .\l c mo1·ial Trust \\'as
establis hed in Australia in 196!1, 1he \'ear in which Sir
Wins to n C l111 rc hill di ed . T he pri11ci1;al object of the
Tni s1 is to pe rpe tuate and honour his memorY bi· the
a ll'ard o r C hurc hill Fellowsh ips.
. .
The aim or t he T rus t is 10 gi1·c opportunity, b~· I he
p ro1·isio11 o r fi na ncia l s u pport, ror Australians l'rom all
ll'alks of' Iii '<: to 1111d crtake O\'erseas sruch-, or an
i111-cstigati1·c project, ora k ind rhat is not a1·ailablc in
A ustra lia.
There a rc no prescribed q11alificat ions. acadc111ic o r
otherll'isc. for the all'ard or a Churchill Felloll'ship .
.\ le r it is the prim ary tes1 , ll'he1her based 011 past
achie1-c111en 1s o r d emonstrated abilit\ for future
ac hic1·e mc11t. in a n )' walk ol' life. Th~ value of a11
a pplic ant's wo1·k ro the cum11111 n i1y and the ex1c11t to
w hich it w ill be e nh a nced b~· the ;;pp licant's m ·crseas
s tud ) pn>ject a rc import:int criteria taken into account
in sclcc1ing Ch11rchi ll Fclloll's. I loll'eve r , Felloll'ships
ll' ill 1101 ord inari h· be awarded in cases where the
p rirnar)' purpose'c>r 1hc applicat ion is 10 enable the
applicant to obtain higher academic or l'ormal
qualif'ica1ions, nor to t h ose in a l'Ocation ll'hicli oile rs
s pecial o pportu11i1 y fo r Ol'crseas stud)'.
Churchi ll Fe llows are provided with a return
cco110111)' class overseas air ticke t and an Overseas
Lil'in g Allowance to c11a blc the m to undertake their
a p p roved st ud y pn~ject. I n special cases they 111ar also
be awa rded s 11pplc m e11tar)' allowances including a
De pendants' A llowance. Fif't )' one Churchill
Fellowships we re awarded for 1981 at a roral budgeted
cost o r $450,000.
All Churchill Fellows are presented, at an
appro priate cerc111011\'. with a certillcate a n d bacl<re
id e11 ti f)·i ng them as such. The certi l'icate bestows u 1~n
the recipie nt the prestige of" being a Churchill Felio\\'
and opens 111any doors 01·erscas 1hat 11·ould otherwise
be closed to a 1;ri1·a1e i11di1·icl11al.
It is more than JO )'Cars since a Fellowship was
all'ardecl for study assoliated ll' ith the al'iation
i11dus1r~-. This cot; kl be an opportun it1· fo r a member
or t he in cl us t ry lo help others in a 1·iario;1 as t he resu ll or
th e ir emlea1·0 11r and the assista n ce prnvided b )' a
Churchill Fellml'sh ip .
Applications
The Trust is calling for ap plicat io n s from Australia11s,
01· 18 yea rs and ove r from a ll walks or life, ll'ho ll'ish 10
be co11siclcrecl f'or Fclloll'shi ps tenable in l 982.
Completed applicat ion fo rm s a ml refe rences must
.reach the Trust by 28 f'ebniary 1981. Applicants
s hould send their name and address now, with a
request for a copy of' the information brnchurc and
app_licatim 1 for m s, to either the appropriate state
capital city or t he Canberra office :
The Winston Churchill Memoria l Trust (f\ I)
G. l'.O. Box 498 ADELAIDE S.A. 500 1
l'.0. Box G209 H ar Street Easl PERTH~ W.A . 6000
G .l'.O. Box J260N HOB A RT TAS. 7001
l'.0. Box 2 147 DA R WIN N.T. 5794
P .O. Box 478 CAN BE RRA C ITY A.C.T. 260 1
e
Aviation Safety Digest 111 I 7
�Seat belt adjustment problem
Three bar adjusters
allow permanent
adjustment of belt
length.
~
Free end of strap which
should be turned bac k and
stitched or stapled to
prevent it pulling back
through adjuster.
T he fo llo wing text from an in cide nt r epo rt, while of
special in te rest to ae ro batic pilots, h as gene ral
appl ication.
'While adj u sting my h arness before ta xiing for a n
aerobatic tra ining fli g ht, I fo u nd that I could no t
tigh te n L11e la p stra p su nicie ntly. I sh ut down tl1e
c ngiu c and inspected th e strap whe re it was
a ttached Lo the air fra me . A co mpa r iso u \\'ith th e
fron t ha r ness showed that th e r ea r on ~ was
incorrectl y secur ed a nd I f o u nd that I coul d work
the stra p loose by p ull in g it up wards. T h e strap had
eith er been incorrectly a ttach ed to the aircr aft or it
had worked loose' since its a ttach m cnr. T he o the r
la p strap for th e rea1· sea l was similarly fa u lty. I
attach ed the rear straps correctl y, checked th e front
straps th oroug hly a nd p roceeded witli the fl igh t. I
h ave since no tified th e o perator and club instru ctors
abou t th e incide nt beca use th e co nseque nces o f a
simila r, f u tu re occur rence in a n aer o ba tic ae ro p lane
could be somewha t emba rrassing .·
T he accom panying illustra tio ns and the followin g
text from Airworth iness Ad visory Circular 87-5
o utl ine the proble m a nd the solution to it.
'A haza r dous situ a tio n ma y be created if"
re peate d , inco r rect ac~j u st mc nL o r some ge ne ra l
aviation scat belts is car ried o u t. On most types, the
8 I Aviation Safety Digest 11 1
The photograph above shows the harness as found on a Bellanca.
Note the limited accessibility, and the fact that this is on the more
accessible side, adjacent to the large entry door. The free end of the
strap should be passed back through the adjuster, which is too far
up from the end fitting.
sho rte r we bbi ng le ngth 11"11ic:h carries the buck le
includes a f"i u in g fo r connec1 io 11 Lo th e floor
ancho r age an d a 11 acij ustc r which enables the buck le
to be correctly located at the side of the 11-carcr.
T h e tota l le ng th o f" this see1io11 o l· webbing is such
that no rma lly a n a m ple a111 o un1· exists for the
ad juste r LO remain secure. P ersona l adj ustmen t o f"
the be lt sho ul d be carried ou t on the other we bbing
stra p , i.e., o n the side of the belt con nector, so tha t
appropriate bu ckle loca tio n is main ta ined.
O ccasio na ll y it may be necessary to make a s111a ll
ad justme nt o n the buckle sid e whe n the sca t is
shifted to extre me positions. Th is aga in i11trod uccs,
b)' itself, no specia l hazard in view of the free
len gth of we bbing norma lly available. H owever, the
free end s of ma ny of t11esc straps arc 1101 sewn
over , a nd if' re peated and incorrect perso na l
acUustm ents have bee n ca rried ou t o n the bu ckle
side th e webbing may req ui re o·nl y a small amo u nt
o r slip be fore the encl will pass through the adjuster
and re nde r the restraint system ineffective. It is
therefore advisable 10 check, before buckling u p,
tha t the bu ckle is located al the side of the occupant
an d tha t a safe free le ngth or webbi ng p ro tr udes .
th roug h th e adjuster'
e
Dirt strips: excessive brake wear
A Piper Aztec was opera ted around south eastern
Queensla nd a nd regu larl y flew in to comparatively
sho r t, d irt strips. On the clay of the accident tl1e
pilot com me nced fl ying at 0620 h ours local time
a nd by mid day had completed six nights totalling
a bout th ree ho urs fl ying with an average b reak or
l 5 minu tes bet wcen fl igh ts.
At 1200 hours the aircraft took off from I 050
metre station str ip with the p ilot a nd three
passe nge rs O il boar d . T h e purpose or the flight was
to insp ect th e bou ndary of an adjoining propel'l)'.
The i nsp ection was completed in abou t I 0 min u tes
a nd th e pilo t r ejoin ed the cir cuit for an ap p roach Lo
th e uo r th weste rl y strip. The wind was light and
variable so he elected to land up the slight slope.
J\ short field app roach with full flap was made
a t 70 knots a nd touchdown occurred 150 m etres
in to the strip. Abo ut halfwa y along the strip th e
pilo t ap plied lig h t b raking. H e gradually increased
the bra ki ng p ress ure u ntil nearl y 700 metres of the
strip had p assed. By uow he had ap p lied maxi m um
bra king but the r e was a no ticeable lack of
reta rd a tio n .
As the ai rc1·aft a pproached the end of the strip ,
it beca me obviou s to th e pilot tha t it was not going
LO stop . He steer ed th e ai r cr aft clear or two othe r
ae ro p lau cs pa r ked by the side of th e sti·ip a nd th e
Az tec: h it th e post and wire fence at abou t 20 knots
suffe rin g su bsta ntial d amage, mainly to the rig h t
wing. T he occupan ts were u ninj u red.
The in vestigatio n of the accident included close
exa minatio n o f th e a ir cr aft braking system .
FuncLio ual ch ecks revealed that tl1e braking system
appeared to be op erating norn1a ll )'. T he aircraft log
boo ks ind ica ted tha t th e brake pads we re replaced
at the last 100 ho u rly inspection, which occurred
abou t 60 ho urs p r io r LO the accide nt. Inspection of
the brake pads revealed however , that they were
worn beyond acceptable limits. This wea r had been
progr essively compensa ted fo r by the automatic
brake adjusters and braking efficiency had
apparently not been affected u n til the landing on
which the accident occurred. A contributing factor
was a slight oil weep from the left hand , rea r brake
caliper assembly. This would have caused an
accu m ula tion of din a round the br a king mech a nis m
which accelerated the rate of wear.
Reference to the Compan y Operations Manual
showed that visual inspection of th e wheel brake
system was not called fo r i n th e Pilot's Dai ly
Inspection Schedu le, nor was th is a requir em ent of
the Aircr aft Owner 's H a ndbook. The Daily
I nspection Schedule in Air Navigation Order
100.5.1 Ap pendix 4 also does not requ ire a specific
inspection or the wh eel brake section.
I n view of the lack of specific d irections for
wh eel brake visual checks between period ic
inspections, consideration was given to amending
the Da ily I nspectio n Sch edule . It was concluded,
howeve r , that the excessive wea r r evealed du ring
this in vestigation would be restricted to aircraft
making a large number of landings, o n u nsealed
strips, which involved h igh brake usage. I n
ad dition, th e in spection wo uld be impractical on
ai 1·Cl'aft fi tted with d ru m brakes or wheel spats.
Rathe r than in clude a specific requirem e nt in the
app licable p u blications it is strongly recom m ended
that o p erators ensu re that their p ilots arc aware of
the additional brake pad wear wh ich is likely to
occur when operating from d ir t str ips. Any visible
sig n of oil weeps from me b1·ake actuators should
also be attended to in order to reduce acceler ated
wear or the brake pads and d iscs .
Aviation Safety Digest 11 1 I 9
�Vision 4 - what meets the
the eye • • • real or illusion?
....
Apparent height
Height relat ive
The fourth article in a series concerning the physiological, psychological and environmental factors
that affect visual efficiency.
'Human e rror' and 'approach a nd la nding' a re
phrases fre que nlly used in describing causes of
a ircraft accidents. Statistics reveal that abo ut 85 pe r
cen t of aircrart accide nts in volve hu1 mu1 error as a
contributing factor. In addition, abo ut 50 pe r cent
of all accide nts occur d urin g the a pproach and
landing phase.
Your primary role in the cockpit is making
d ecisions. In orde r co do this yo u must sense a nd
p rocess information . Poten tia l sources of e r ro r
ra nge rrom limita tions in your senses a nd
pc 1·ceptual mecha nisms to inadequ acies in
procedures and methods prescribed for th e fligh t
crew. T his article wi ll briefly present some
cha racteristics related to sources of informaLion
processing error du ring th e a pproach a nd la nding.
You r senses receive physical s timuli a nd encode
information ; perception inLe1·prets informatio n a nd
attaches mea ning to ir. Most of the in formation
which you receive comes to you through your eyes;
some comes from instrument displays in the
co~k pi t, but a la rge a moun t is obtained from
outside th e cockpit, often under conditions which
may be fa r from ideal. Indeed , ccnain con cl iLio ns
may prevent th e necessar r information from even
reaching the eye. More o ften a sig na l reaches the
eye but the brain misin terpre ts and you 'sec'
So lllething else; in othe r wo1·d s you experience a
visua l illusion. We will discuss onl y th e illusion , or
false p e rce ptions, associated with direct vision .
Visua l illusions a re potentiall y common in fl ying
and res ult from the inconect interpretation of what
you see . This may be due to there being too few
visua l cues so that you have to fill in the rest of the
picLUre by drawing on your preconception of the
situation , by 'seeing" what you Lhink you 'ought' to
sec, or simpl y by guessing. It may also occur when
cues presenLed LO the norma lly master se nse, visiou,
are weak and are in confl ict with relatively strong
responses by orher senses, particula rly those or
ba lance and orientatio n , which have sensors in th e
111ner cars.
T he purpose o f this a r ticle is ro draw your
auentio n to some of th e circu msta nces in which
visual illusions may be ex perienced a nd to the
hazards which the illusions may introduce o n the
approach to land. Increased awa re ness of these
factors will enable you to recognize and compensate
for most visual illusio ns and so reduce the risk or a n
accident.
Visu al illusions during the landing a pproach may
be caused by 011e <ff any combinatio n of the
following features:
Sloping a pproach terrain
Sloping runways
Runwa y widLh
Rain on the windscreen
Featureless approach ter rain
Run way ligh ting intensi ty
Shallow fog
Ra in showers
Darkn ess
Black hole e ffect
Sloping approach terrain
No rmally, when a pilot makes a visual a pproach he
subconsciously j udges the approach path fro m a
combina tion of Lhe apparen t distance of the a ircraft
from the run way and its a pparent height above th e
a pproach terrain. If the ground unde r the ai rcraft
slopes up wa rds LOwards the thres holc.l an illusion
ma y be createc.l , particula rl y <lu ring Lhe early stages
or th e approach , that the aircrart is too high (see
Figure l ). Conversely, g ro und which slop es
Height relative
to runway
Apparent height
Upsloping approach terrain (Figure
10 I Aviation Safety Digest 111
1)
Downsloping approach terrain
(Figure 2)
downwards towa rds the th reshold gives the
im pression th at the approach path is too flat (see
Figure 2).
Sloping runways
T h ro ugh the regular use o r lLS glide paths and
V AS IS, wi th three degree glide slopes, pilots
become accustomed to th e complementary angle of
177 deg rees between the runway and the ap proach
path (see Figure 3 ). Ad ditionally, from experience,
p ilots come to know wiLh considerable accuracy the
amount of power requ ired to maintain the co1Tect
ap proach path to the point or touchdown. If,
however, th e run way slopes upwards from the
la nd ing threshold and the 177 degree relative angle
is maintained , a visual approach will be lower than
it shou ld be, by abou t the same amoun t as the
runway upslop e, a nd the 'usual' power setting will
be inadequate to meet the requirements of the
flatter a pproach . If the runway has a downslope,
the converse a pplies, so that by maintaining the 177
degree ang le 1·elative to the down-sloping runway,
the ap proach to the touchdown point will be steeper
a nd the 'usual' power setting in excess of that
required.
Runway width
The ability to use the apparent convergence - d ue
to pe rspective - of two parallel lines to estimate
th eir le ngth is well known . I ncreasing or decreasing
the distance between the lines, however, can u·eate
the illusion o r shortening or lengthening them. On
the ap proach , a pilot bases part of his judgement on
a me nta l comparison of the runwa y before h im with
the ' no r mal' view of the runway to which he is
accustomed. Variations in the runwa y width,
therefore, can be misleading. For example, the
wider the run way, the shorter it appears; moreover,
the width can also have an effect upon Lhc apparent
height of th e a ircraft in relation r.o the runwa y, a
wide r run way making an aircraft appear lower than
it is.
Rain
H eavy rain ca n a ffect the pilot's p e rce ption or
distan ce fro m the approach or run way lights by
d iffu sing the glm.v of the lig h ts and causing them to
appea r ress intense. T his may lead him to suppose
that the lights are farther away than in fact they
arc. On the other hand, only a li ttle scattering clue
lo wate r on the windscreen can cause runway lights
to bloom and double their appa rent size, with the
result that the pilot believes that he is closer to the
runway than h e actually is, leading possibly to a
premature descent. Similarly, rain on the
windscreen can cause illu sions as a result of light
ray refraction. For insLancc, eve n though an aircraft
is correctly aligned on the approach path iL can
appear to the pilot to be above or below the correct
glide slope, or le ft or right or the ru n way centre
fine, depending upon the slo p e of the wmdscreen
and other circumstances. The apparent error might
be as much as 200 feet at a distance of one mile
from the runway threshold .
Featureless terrain
Visual descents over calm seas, deserts or snow, or
over unli t terrnin at night, can be hazardous even in
good visibility. The absence of external vertical
references makes j udgement of heigh t difficult and
the pilot may ha ve the illusion of being at a greater
height than 1s actuall y the case, leading to a
premature 01· too rapid descent. Height above the
runway is also made more difficult to judge if,
because of snow for example, there is no contrast
between the ru nway su rface and surrounding
terrain. The problem is compounded if the descent
is made into the sun or in any cond itions wh ich
reduce forward visibility.
Runway lighting intensity
Becau se bnght lights ap pear closer to the observer
and dimmer lights farth er away, the intensity of the
approach and runway lighting can create illusions.
T h us, on a clear nigh t, the runway lights may
appea1· closer than they actuall y are, particularly
when there are no lights in the sunound ing area.
Shallow fog, haze
I n shallow fog or hazy conditions, especially at
night, the whole of the approach and/or run way
lighting may be visible from a considernble distance
on the approach even though Runway Visual Range
or meteorological reports indicate the presence of
fog. On descent into such a fog or haze layer, the
visual refe rence available is likely Lo diminish
ra pidly, in extreme cases redu cing from the full
length of the a pproach lights to a very small
segment. This 1s likely to cause an illusion that the
aircraft has pitched nose up, which may induce a
pilot to make a corrective movement in the opposite
direction. The r isk of striking the grou nd with a
high rate of descent as a result of [h is erroneous
correction is ver y real.
Aviation Safety Digest 111 I 11
�I
Bright city lights
\
\
Level runway, aircraft
on correct glideslope
Ocean or featureless terrain
Upsloping runway, aircraft
on correct glideslope
Black hole effect
Danger!
Pilot's natural tendency 1s to correct
downwards to intercept his ·natural' angle
of approach
I
\
Downsloping runway, aircraft
on correct glideslope
Sloping run ways
(Figure 3)
Rain showers
A wea Lh e r fea ture which ma y reinforce a pilot's
visua l indica tions that he need not appl y power to
reach th e run way or to a rrest a high ra Le o f desce nt
is an isolated rain shower. A heavy rainstorm
moving towan.is an aircraft can cause a shone11ing
of Lh e pilot's visual segment - that d istance a lo ng
the su rface visible to the pilot over the nose of the
aircraft. This can produce the illusion that th e
ho rizon is movin g lower a nd, as a result, is often
misinte rpre ted as an aircraft pitch change in the
nose up d irectio n . A na tural resp onse by a p ilot
would be to lower the nose or to decrease, not
mcrease, power.
Darkness
T he greatest illusion potential exists at night.
Da rkness provides excellent camouflage a nd th e eye
loses much of its efficiency. Normall y used cues
such as shadows, colour and detail arc not availa ble.
Lights must compensate for th is loss, but lights
usually lac k sufficien t d e fini tion to provide more
than a n o utline, an incomplete stimulus LO which
the pilot ma y or may not r eact correctly. AL th e
othe r c ud of the scale we have a profusion of lig hts.
La rge a irfield complexes h ave so man y lights Lh at
12 I Aviation Safety Digest 111
frequentl y th ere is considera ble difticulcy
ex pe rie nced in j ust findin g the runway.
Black hole effect
This illusion can occu r o n a clear night with 110
visible horizon . T h e ai rcraft a p proacnes the runwa y
over the sea or other featu reless, u11l it terrain
towards an ae rodrome wiLh bright ciLy lights behind
it. Visibility is so good that th ere is little need to rel y
on Lhc instrume nts except lO check the airspeed.
The straight-in approach is totall y uneventfu l uncil
tl:le aircraft lands short of the runway, possibly by
several miles. What could have gone wrong?
Tests have sh own that under these circumsta nces
a pilot rel ying on a visua l ap proach will Lend to fl y
a long the arc o f' a circle centred above the p attern
of city ligh Ls with iLs ci rcumfe rence contacung th e
tcrram. Such a path res ults f'rom main tain ing a
constant visu al a ng le subtended at the eye by the
nearest and farthest ciLy li ghLs. When deccptjve
conditions arc present , sucn as up-sloping city
terrain , this kind of a pproach paLh ca n go to
critically low altitudes. T he lack of fo1·cground
lighting res u lts in the p ilot being d enied im porta nt
closure information without his awareness and
conscqucnLl y the a ircraft la nds short.
(Figure 4)
Avoiding the problem
Be aware or the circumstances in wh ich visual
illusions may occur anrl be prepared t.o take
corrective or a lternative acuon . Learn LO recognise
impendi ng situatio ns which may place Lhe saf'cl)' or
the aircraft and its occupants in jeopardy.
Study aerod rome charts, maps a nd other
applicable reference material lo determine runway
slope, th e slope of terrain around the aerodrome,
the relati ve position of the acrorlrome and
surroundin g features, the aerodrome approach and
runwa y lighting in use, etc., etc.
Anticipate the n eed fo1· rain repellam m1 the
windscree n and use as appropriate, before
de pa nu re.
Wherever available use ILS or V ASIS to monitor
the gl ide slope. If a DME is located al the
aerodrome use the 'rule-of-thumb' 300 reel per
nautical mile for your descent prof'ilc, but
remember to take in to account the relationship of
the DME beacon to the threshold of the runway in
use.
I f the nominated run way has no precision
approach a ids, consider the need LO req uest an
alternative run way with precision aids. When no
precision aids are available fl y a f'ull cirrnit, never a
straight-in approach . The aircraft can be more
acrnrarely positioned al 600 feet on a two mile final
havin g fl own a fu ll ci1·cuit than on a straight-in
approach withou t a id s. It may also be possible LO
posi tion the a ircraft at a known point. such as over
a locator, at the co1Tect altitude a nd approach
configuratio n. The pilot should th en obtain a visual
image of the runway and maimain this image
throughout the ap proach. If none of the fo\egoing
proceau res arc possible, consideration should l)e
given to diverting Lo a more suitable <ierocl rome.
On two- pi lot op erations use th e moni torcrl
ap p roach techn ique. One pilot flies the instrument
approach while th e pilot who is LO land the aircraft
mo n_i tors th e <_lpproach and g~ins 'experience' of the
ambien t conchuo ns before takmg over control.
During single-pilot, IFR opcraLio11s the pilot
should use the aut_o pilot as th e pilot !l ying Lhc
approach. While flying a coupled approach, th e
'real' pilot should try to gain cxpenence of the
conditions. The auwpilot should remain engaged as
long as possible un til Lhc pilot has obtained a good
vis ual p icture, and a saf'e landing is assured.
On all operations, avoid landing expectancy; be
prepared to go around or carry our a missed
approach if there is any doubt about the saf'ct y of
the landing.
Wherever possible, pilots should receive training
flights to aerodromes where it is known that
conditions can be conducive to visual illusions.
In conclusion, remember that illusions 111usr be
expected in fl ying. Also that it is human nature to
want LO believe our own senses rather than
i11strume11L indications. Knowledge of illusory
scnsati ~ns will help because ou.r responses are
detcrmmed more by the meaning we attach to
stimuli than by the stimu li themselves. It is
uhimately on the basis of knowledge and sel f
discipli ne that we make decisions and select our
responses.
H ow sharp arc your eyes? Di d they catch the the
title ?
e
Aviation Safety Digest 111 I 13
�Systems knowledge the landing gear
Although referring specifically to a particular group of aircraft, this article contains lessons applicable
to the operation of any aircraft fitted with retractable landing gear.
The foll owing brief reports a r c o nl y a few fro m the
record s in volving landing gea r pro ble ms. Far too
ofte n th e inves tigatio n into an accideut o r incide nt
revea ls that the pilo t h ad an inadequa te
understanding of a panicular syste m. This is
especia ll y true in accide nts in volving the la nding
gear. Fo rtunatel y, this type o f a ccident d oes not
u s ually result in fatalities o r serio us inj uries, but
there is always a hig h risk th at so me other fault may
compound the seriousness of th e accide nt. If a n
accide nt can be avoided by a be tter unde rstan ding
of th e syste m oper ati o n , th en surely it is worth th e
slight effo rt required o n the pa rt of tl1e pilo t to
achieve this unde rstanding .
T his article d eals with the r e tracta ble landing
gear syste m s fitted to a ran ge of Beech and Cessna
aircraft, including th e B eech 33 35 36 55 56 1)8
60 and 95 series, and the Cessn~ 3 1,0 , 3'20 ~nd '340
series. The normal and e m er gency oper ation of t11 e
sy~tem a nd so m e of" the fail u r es which have led LO
accide nts will be d iscussed.
e
After m~ki ng a n ae rial ins peCLion o r the land in g
ar ea , the pilo t of a Beech Bo na nza co ntinued the
circuit a t 500 feet AGL Turning base sh e selected
the landing gear d own , heard a n d fel t the d oors
o pe ning a nd the motor op e r atin g, and no ti ced an
i~1 c rease in drag . Neith e r the la nding gea r warnin g
lig h ts nor t11 e nosegea r m echanical iuclicator were
ch ecked. The approach was continued with 25
degrees o f fla p selected and a fte r round ing out, th e
Bo na nza la nded o n the ope n gear doors, m e fl a ps
a nd the lo we r fuselage su r face. The pil o t and fo ur
passe ngers we re uni nju red.
Subsequ ent in vestigatio n revealed tha t the
landing gea1· m otor had an inte r mittent fault a nd
the circuit brea ker had pop ped a fter the doors
o pe ned. As is so oftcu the case, t11e landing gear
warning ho rn system was a lso fou nd LO be fa ulty.
The com me rcia l pilo t had flo wn more than 200
ho urs o n the Beech 35 sin ce h er conversio n o nly
three momhs earlier.
e Just afLe r ta king off o n a test flig ht to check th e
press u risation system, the pilot of a Beech Du ke
selected the landin g gear up. I t a p peared to retract
norma ll y and the aircraf t accelerated , however, the
unsafe gear wa rning light remained o n. T h e pilot.
selected the gear down and h ear d a p rono u nced
'clun k'; t11 e mai n gea r locked in p lace but th e
unsafe lig ht was still ill um inated a nd the nose gear
clown lig ht was out. H e ch ecked the nose gea r light
bul b bu t it a ppear ed to be se r viceable.
After ca nce lli ng th e flig h t p lan and info r m ing the
tower o r th e proble m , me pilot tried cycli ng th e
gea r and using a ma nual extensio n bu t all without
su ccess. T h e aircra ft was flo wn past m e to wer for
~o mpa n y e ngineers to in sp ect the land ing gear and
It was obse r ved m a t th ere was a r od ha nging down
behind Lhe partly exte nded nose gea r.
T he Lowe r advised the pilo t tha t the grass
em er ge ncy strip was a vailable. H e decided to
conduct a fl apless, gear u p landing because of h is
concern tha t. the Du ke might nose o ver if the
main wheels we re le ft dow n. H e also co nsidered th at
d am age could be min imised by leaving the fla p up
a nd landing o n m e !lat centre section of th e
fu selage, o n th e soft, g rass surface .
The pilo t briefed the passen ge rs for the lan din gand eva~ ua ti on, a nd had th e m sit. in rear facing
seats. After two low r uns Lo ch eck the a pproach , th e
aircraft land ed smooth ly a nd slid to a stop.
L
In vestiga tio n r evea led that the nose gear
extend / retract rod h ad failed at a welded joint. T h is
was su bseq u e n tl y de ter mined to be an isolated
occurrence. Beca use of h is handling of Lhe
situa tion, th e pilo t r educed the risk to his
passe ngers and d amage to the aircraft to an
absolute mi ni mu m . Afte 1· recovery, it was found
that the o nl y damage to the a ircraf"t involved the
p ro pe lle rs a nd var io us prorube1-anccs under th e
fuselage, such as p itot tubes an d radio aerials.
e
t
t
Sho rtly after take-off, th e pilot of a Beech
Bona nza selected tl1e la nd in g gear up. He heard the
mo to r ope ra te b1·iefl y t11en stop . The red gear up
ligh t d id no t ill umi nate and the mecha nical
indicator sh owed the nose gear to sti ll be extended .
Bein g unsu re o r th e exact position of the gea r ,
the pilo t a d vised Syd ney F light Service of the
p roblem and so ugh t the ass istance of another
aircr aft which was o p erating iu the a rea. Occupants
o r the o th e r a ir craft indicated that the Bo nanza's
gear a p peared to be dow n a nd locked.
When th e p ilol co nd ucted a tro uble shooting
check, he ro un d th e landing gear motor circuit
brea ker had popped . Fu rther checks r evealed that
th e e me rge ncy extension ha nd le was e ngaged . One
o r the passe nge rs was holdi ng a cam era tri pod
which had ap parentl y bumped the han dle. With the
handle e ngaged th e la ndi ng gear motor had stalled
causing the circ uit brea ker to pop.
Afte r r esetting the brea ke r , the pilot was able to
opera te th e gea r no rmally. Th e ai rcraft then
continued o n its fl ig ht to Syd ney.
e
A Beech Ba ron had jo ined th e circuit and when
the sp eed r ed uced to 130 knots the pilot selected
the la nd ing gea r clo wn. As well as the normal no ises
associa ted wi th th e la nd ing gea r ex tending, the p ilot
heard 'a dull cr ac k like the so u nd or a cover flap
14 I Aviation Safety Digest 111
open ing". Because the air cr aft had recently
undergoue maintena nce including the fitme u t of
some land in g gear parts, he suspected that some or
t11e parts may have been a tj g h te r fit than before.
T he gear clown indicator checked normal and on
fi nal approach , after receiving a land in g clearance,
me pilot again checked that the gear was indicating
down . The aircraft was flared , touched clown
smooth ly and all appea r ed normal.
As the speed reduced, the left wing dropped
slowly and the pilot realised that the gear was
collapsing. H e tried stopping the ai rcraft usin g light
braking but it did a gen tle ground loop to th e left
th rough 180 degrees and came to rest.
I t was subsequentl y determined that the left ma in
gear actuating rod failed earl )' in the extension cycle
and the left gear rema ined o nly partly extended.
Because the gea r warning lights a re not actuated by
the gear legs, bu t by the position of the gea r motor
act uatin g a rm , th e pilot d id not receive any visual
warning of the unsafe conditio n of the left main
la nding gear.
Fortunatel y the damage to th e aircraft was 110L
extensive and there wer e no inj uries suffered by the
two occupants. T he accident docs however h igh light
1he poi nt that the pilot was not full y fami liar with
the landi ng gear system . H ad he und erstood the
operatio n of th e ind icating Jights he ma)" h ave been
more concerned abouL the noise he heard. I f so he
could h ave had the gear checked by visual
observation and then have bee n prepared for an
abno r mal landi ng . The accid ent occurred at a
controlled aerod ro me equ ipped wi th rescue and fire
fig h ti ng facilities but mese had not bccu ale rted
p r ior to th e a ircraft landing.
e
A Cessna 3 10 was o n descen l to destin ation. With
the airspeed indicating between 150 and 160 knots,
the pilot lowe1-cd the la nd ing gear. Whe n a
nosegear down ligh t was not fonhco mi ng, the pilot
recycled the gear th ree Limes but still failed to
Aviation Safety Digest 111
I 15
�obtain a nosegear down and locked indication.
Following a manual extension b)' the pilot, ground
observers confirmed that the nosegear was only
partly extended .
A Distress phase was d eclared a nd afte r th e
emergency services were p ositio ned, the aircraft
touched d own on the mai nwhecls. T he nosegea r
folded back into the well a nd the aircraft slid to a
stop. None of the fo u r occupants was injured.
Subsequem specialist examination of the buckled
nose gea r main drive tube resul ted in th e
conclusio n that the tube had fa il ed beca use th e
landing gea r was selected down a t a speed in excess
of the 141 knots gear limitin g speed.
T he aircraft under discussion iu this article
re present nea rl y 40 per cent of more than 1100
general aviation aircraft on th e Australia n register
which are fitted with re tractable landing gea r. It is
not surprising the refore, that they feature
prom inently in reports or accidents involving
la nding gear colla pse or a wheels up landing. T h er
are not more susceptible to landing gear prnblems
than others, as acciden t involvement remains
approximatel r in proportion ac ross all trpes and
models.
However, as there are so ma n)· a ircraft in this
pa rticular group it is well worth lookin g at them
collecti vely. They share a simil ar type of land ing
gef!r system, a nd the design a nd operatio n is
essentiall y the sa me. In discu ssing the system we
sh a ll diffe rentia te between the two makes wherever
possible. Ens ure that you reso lve anr doubts b)·
referring to th e Owner's Manual or Pilot's
Handbook for the ap propriate t)'pe.
Description of the system
Mechanical
T h e diagram shows that th e heart of the srstem is
an electric motor and gearbox located in the cen tre
section or the wing/fuselage, under the cabin floor.
The output from the gearbox operates pushrods Lo
each main gear a nd the nose gear. Also littccl lo the
gearbox is a manual hand cran k !'or use if electrica l
operation fails. l t should be noted dearly that the
gearbox and pushrods a re utilised for both the
electrical a nd manual operation of the land ing gear.
The h andle for rhe ha ndcra nk is located in the
centre of the ai rcraft cabin floor, just behind th e
pilots· seats aud the m<1in sp a r in Ikech a ircrart,
and just below th e' right fronL edge of the pilot's
seat in Cessna a ircraft.
The la nding gear legs are each moun ted on a
pivot shaft and are raised and lowered by actio n of
the pushrods which are connected lo the geometr ic
down lock 011 each leg. The re is also a mechanical
uplock fitted to each leg. The nosegear is sometim es
fiued with a mechanical ind icator, visible al the
front of th e cockpit.
Electrical
The la nding gear is controlled by a switch on the
instrument panel. The gear position indicator lights
are adjacent Lo the selector switch a nd, for gear
16 I Aviation Safety Digest 111
down , show one o r three gree n lights. The other
ligh l indications va rr from one model to a nother as
follows:
M11fw/M11dl'i
Cmr 11/1
111 //'l/ll,lif/111i/11rlll'lf
Reech 3:~. :~5. 3G. 55. 95
Beech 58. GO
Earlr Cessna 310
l .a1c1· Cessna 3 10. 340
Cessna 320
Red
None
NonC'
Red
No1w
Amber
12
Red
None
Red
Oil<..'
It is possible that ind ivirlual ai 1·craft cou ld ha ve
different ana ngemellls. Before attemp ti ng to
operate a n y aircra r1 ensu re that you know what
indicating systern is fitt ed to that indi vidu a l aircraft
a nd what each indication mean s. The lights are
usuall y dimmable a11d filler\ with a press-to-test
runction.
If the throule is reta rded below abou1 12 i11ches
Il g manifold press ure a nd the gear is retraned , a
wa rning horn i11 the cockpit will sound
in te rn1itten tl )'.
·
A safct)' switch 0 11 o ne or the main gear legs
ope ns the control circuit whe n the strut is
compressed thus p revent ing inad ve rtent retract io n
of the gea r with the a ircraf"t finnl r on th e ground .
Circu it breakers protect the motor and th e visua l
and aural warning and control srsterns.
10----
J
13
General view of the landing gear actuator
assembly
2
3
Operation of the system
Index
Normal
Before flight the emergency lowering ha nclcrank
should be checked to ensu re that th e ha11clle is
correctl y stowed. T h is anion disengages the handle
from th e gearbox worm and stops the handle
rotatin g when 1he la ncli11g gear is operated
e lectricall)'. Injurr LO ocrnpants and damage to th e
gea rbox can a rise if the la ndin g gea r is opera ted
e lectrica ll y with the handcrank e ngaged a nd could
lead to a total failu re of the gear S)'Sle m.
With bauery power o n a nd th e gear down , the
green light(s) should be illu minated, and the
warning horn silent. Any o ther gea r i11dica1ing
lights ca n be checked b)' the press-to-lest fun ction .
After ta ke-off, whe11 the aircraft is well clear of
th e groun d, th e selcnor switch is raised to the UP
position. Electrical power is supplied 10 the gear
motor which turn s th e gear box acLUator arm.
Simulta neously, the clown lock on each leg is
u11locked by its pushrod. The green ligh t(s)
extinguish a nd the gear retracts. If fitted, the
in-transit light illu minates.
Towards th e encl of the retract cycle the la nding
gear doo rs, whi ch remain open while th e gear is
extended , are closed 111echanicall y, the uplocks
e ngage a nd the motor is shut off by a trn vel limit
micro-switch on th e gea rbox. At that ti111e th e
transit lig ht extingu ishes and /o r th e gear up light
illu minates.
The extension cycle is th e reverse or the
retraction cycle.
Emergency lowering
The manual extension of the landing gea r is
described in the Eme rgency Proced ures section of
the ap propria te Owner's Manual or Pilot's
H andbook; however , it wi ll be usefu l to d iscuss th is
proced ure more full y than g ive n the re.
Emergency extension handcrank
(engaged)
4
2 Handcrank housing
3 Actuator worm gear (inside housing)
4 Electric motor and reduction gear
assembly
5 Actuator sector gear
6 Lower actuator housing
7 Nose gear retract arm
8 Upper actuator housing
9 Main gear retract arm
10 Actuator drive shaft
11 Upper actuator support
6-----1
12 Micro switch assembly
13 Emergency extension handcrank (stowed)
Exploded view of the actuator assembly
Diagrams from the Illustrated Parts Catalogue
for the Beechcraft Baron 58P
Aviation Safety Digest 111 I 17
�Circuit breaker, check IN first with gear selector
DOWN. If Lhc gear does nol extend, pull OUT.
This will prevent eleclrical power operating the
gear motor while the handcrank is bein g used ,
thus avoi ding the possibility of damage Lo the
gea rbox and injury to the person operating the
handcra n k.
Landing gear sclecLOr switch, DOWN (Beech) or
NEUTRAL (Cessna). In th e unlikely situation
that an electrical f'aull could cause power to
bypass the circuit breake1- and drive the gear
molor, it will nol be drive n in the opposite
d irection to the h and crank thus preventing
d a mage to the gearbox.
Engage th e handcrank
B y lifting the h andle on its pivol, the h and cran k
shaft engages Lhe worm gear in the gearbox .
T urn anti-clockwise (Beech ) as far as possible
(a pproximately 50 turns). This winds the
landin g gea r down. If th e handle is turned
clockwise, the gear will be retracted . T h e
opposite directio n of rotatio n applies fo1·
Cessnas.
Fifty turns is a pproximately the lotal required to
extend th e gear from the full y retracted
positio n. If a failure occurs in an in termediate
positio n fewer turns will be required Lo reach
th e foll y extended position. It is essential that
the ha ndle is turned in the correct d irection
u ntil it will turn no further .
If the electrical system is operative, check the
·landing gear position lights and the warning
h orn after ensurin g that the circuit breaker is in.
Also check the mecha nical nose gear indicator , if
fitted.
Disen gage th e hanclcran k.
Note: Always keep the handcran k ha ndle
stowed when not in use. This will prcvem
inad vertenl engagement if' the handle is
accidenLl y knocked.
Do not re tract the landin g gear manually. The
man ual extension sysLem was not des igned to cope
with the stress imposed by trying to raise L11e
landing gear. T h e weighL o f th e gea r may cause a
failure of the handcran k mech anism if retraction is
attempted thus preventing possible futu re exlensio n
prior to la nding. If Lhe landing gear fails to re tract
a fter take off, select it down , ch eck it by wh aLeve r
means are available and land.
System limitations - malfu nctions
T here a 1·e several factors which limit the op eration
of the landing gear system and sho uld be
understood by th~ pilot.
Gear position lights - Beech aircraft, except 60
series
The gear position ligl1ls arc operaled by
micro-switch es mounted o n the gear box. T hey
sh ow th e p osition of th e gea r box ac LUato r arm , not
the positi on o f Lhc gear legs . lL is possible lo obtain
'clown a nd locked' lights even though Lhe land ing
gear, or p an of il, is not fu ll y exte nded. Th e nose
gear mecha nical indicaLOr overcomes sorne of th is
proble m . Visual inspection from Lhe ground will
indicate if th e main gear is down . Do noL re ly o n
noises or Lrirn changes of th e aircraft to ascertain
the position of the landing gea r.
18 I Aviation Safety Digest 111
Manual extension
Always comply fu ll y wit11 the emergency p rocedures
printed in the Owner's Manual and refer to any
placards fi tted to the aircraft. Practice the
procedure before you need it in a n emergency.
associated with th e gear syste m do not assume that,
because the indicating lights appear Lo be normal,
the system is full y operable. On extending the gear
again consideration should be given Lo obtaining a
visual confirmation of Lhc landing gea r position.
Early retraction
If the landin g gea r is selccLed up before the wheels
are clear of the ground it is possible to bend one o r
more of the o peratin g pushrods. If th is is not too
severe, the gear will probably retract normall y, bu t
when ex tended il will not lock down. As p reviously
ex plain ed, because th e micro-switches a rc on the
gearbox o f' most Beech ai rcraft the gear down light
indicatio ns will be normal but th e nosegear
mechanical indicato r will not show fu ll y down if the
nosegear push1·ocl was bent. A nother consequence
of bent pushrocls on a ll makes and models can be
th e fa ilure to operate the electric motor ctlloul li mit
switch ; this ca n result in serio us gearbox damage. If
Lhe gea rbox is <lamaged the handcrank will
obviou sly be useless.
As there is n o inflighl cu re for this situation if' it
arises, th e p ilot will be faced with an emergency
landing. In this case p 1·evention is th e a nswer - do
not retract the gear until th e aircrah is well dear of
the grou nd. If yo u suspect tha t the gear ma y have
been retracted ea rly, perh aps damaging th e
mechan ism , declaring an emergency and
proceeding LO th e nearest con trolled aerodrome will
allow you to at leas t obtai n a vis ual inspection by the
control LOwer before landing ; e mergency services
can th e n be standing by.
General consideration
Never inten tionally silence Lhe landing gea r warning
horn. If repeated sounding of horn is clislractive,
su ch as during periods of d u al instruction , Lhe
instruclor should conduct a comprehensive briefing
prio r to begin n ing th e exercise. If an unsatisfactory
siLUalion arises during flight, he should take over
control, correct the situation and rebrier the pupil.
Solo pilots should never silence an y warning alarms.
rr al a ny time the integrity of the landing gear is
in doubt, treal it as unsafe, declare an emergency
a nd obtain the max imum possible assistance.
Do no t panic. History shows that gea1· up
landin gs do nol resulL in excessive damage Lo the
airc raft or r isk Lo the passengers, particularly if the
odds have been stacked in your favo.u r.
Prevention of inadvertent wheels-up landings
T he preced ing infor mation has been mainl y
directed al overcoming problems associated with
mech an ical failure. Another major cause of
wheels-up landings is Lhe pilot forgetting to lower
the landin g gear. We recommend the following
tried and proven procedures Lo pr event inadvertent
wheels-up landings or inad vertent retraction after
landing:
Carry and use a comprehensive checklisl.
On downwind leg, or at the final approach fix
inbound, make it a habit to complete Lhe
prelanding checklist. This will ensure that action
has been taken to lower the gear, and it
increases you1- awareness so you can 1·echeck the
gear inclicaLOrs before landing.
After selecting the gear, check the indicators .
This applies to an y control in the airc1·aft e.g.,
after selecting the boost pump on, check Lhe fuel
pressure.
Complete the landing roll and turn off the
runway before operating an y levers or switches,
unless good operaling practice calls for such
action. Doing this will ensure that the landing
gear stru t safely swiLch will be actuated, thus
deactivating the retract system. After rollout,
you will be more composed and less likely to
misidentify switches and levers. Too often Lhe
landing gear is relraclecl instead of the flaps
when the aircraft was on a long run wa y that did
not require the maximum b raking effort after
touchdown.
Learn as much as you can about the aircraft you
arc fl ying. Knowledge is your primary assel in
overcoming undesirable situations
e
Late extension
If the land ing gea r has not been cxtcnclecl by late
final a pproach , a nd th e pilo l recog nises Lhc
situation in time, he should comm ence a go-a ro und.
If Lhis is not possible, it is p roba bly better Lo leave
the gear relractecl and minimise da mage to the
aircraft. Lan ding on a p artly ext.ended landing gear
will resul t in a gear collapse and more damage than
land ing on the uncl ersu rf'ace of' th e wing and
fu selage .
Electrical failures
These usuall y occur when the load m1 the syste111 is
highest i.e., d uring the retraction cycle. If a LoLal
eleclrical failure occurs yo u may initiall y thin k that
the retraction cycle was completed as there arc no
lighL indications. Fluctuating o r zero read ing fu el
gauges a nd OLh er electrically powered ins tru men ts
will confirm a lotal e leclrical failure . l f the failure
occurs during the relraction cycle the ha ndcra11k
will not require 50 revol u tions lo obtain the gear
clow n and locked .
Wind it in the ap propriate directio n as fa r as
possible and , ii' electrica l inclicalions are not
restored, try to obtain a visua l check of' th e gea r
before lan d ing . Always use the mechanical nosegear
p osition ind icaLOr, if fi tted, to de termine the
nosegear posiLion .
Initi al actions if an electr ical failu re is suspected
will , of course, be to check all ci1·cui t breakers, L11e
amme ler and oth e r ap p licable incl:calors.
Mechanical failure
If during gear extension or retraclion strange
sounds arc heard that a rc considered to be
Aviation Safety Digest 111 I 19
�Fuel starvation in Hughes 500
helicopters: missing fuel tank vent
fairing
T he pilol had planned a !'err)' tliglll in a Hug hes
500 he licople r l'ro rn Kunurlllrra to D e1·h y, in north
western Auslralia, a distauce of 306 na utical m iles.
The es tim ale d elapsed time l'o r th e !light was 170
minutes wit h l he fue l endura nce nominated as 260
Ill in utes.
Fue l carried 011 the aircraft co nsisted of 2-tO lilres
usable in th e aircr a ft system and abou t 200 litres in
an un ap proved, a u xi liary fuel syste111 which
co nsi sted Of a 200 li tre drum st ra pped to a ll'OOden
cradle with two e lect r ic fuel pumps a tl ached to it.
T he assembl)' was placed o n the lloor in t he rear
passe nge r compartment and loosely restrained by
two cables auached to lloor hard points. The
pumps were co rmected b y hose lo a titling on t he
ai rcra ft ta n k l'iller neck inside the cabin and were
electrically powered t hrou gh the utility power
swilc h on th e pilol's instrument panel. They
transferred fuel from the a ux ilia r )' ru e! tank into
the aircra l·l ta n k.
A fter d eparting Kununurra the fli g ht proceed ed
normall y for abo u t two ho u rs. The p ilo t then
selected on th e auxil ia ry fuel sys tem and lhe llig hl
co ntinued wi thout incident fo r another 25 minutes.
At this time, as the aircraft approac hed Derby at
abo ut 1OOO feet a ltitude, th e e ng in e failed. The
pilot com m e nced a n autorolation approac h at 60
knots lo the onlv clear area a vailable. H e re duced
gro und speecl to ' ze ro abo ut I 0 feet above the
clearing and then d esce nded ve rt icall y, a tte mpting
to cus hion rhe landing wi lh lhe rema inin g rotor
RPM .
Touchdown was heav)' , the right skid broke a nd
rh e hel ico pter ro lled slowly to the rig ht, corning to
r est o n its side. Arter turning off t he frrel a nd
elect rical swi tches the pilot evacua ted the w reckage.
Later, whe n he fe lt ass ured thal t he re was no ri sk
or !'ire, he returned to th e cockpit an d was able 10
advise De rby Flight Se r vice Unit, b)' rad io, of his
si tu ation .
S ubsequent exami na lion o f the wreckage revealed
that th e tWO Section, bladder t)'Pe, aircra ft rue! tank
lrad collapsed and con tained o nl y one li t re of fuel.
There was no evid e nce o f fuel leakage from the
a ir·crafl sys lern nor or s pillage rrom it a rter the
accident.
The auxiliary fuel system was still in side the
aircrart a nd contained abo ut 140 litres or fuel.
There was evid ence in th e wreckage and on the
surrounding grnu nd that fuel had spilled from the
a uxiliar y fu e l rank ve nt after the aircrafl had co111e
to rest o n its side. It was also fo und th at the wires
supplying tir e e leclrical power to th e a u x iliar y f'uel
system we re broken, however, it co uld not be
positively estab lished when th ese breaks occu rred .
The major part o r t he plastic cover over the
ai rcraft fu e l system ve nt, know n as t he fu el lan k
20 I Aviation Safety Digest 111
lowe r ve nt fai rin g and no rmall y located o n t he
und ers ide o r th e ruselage. was missing» /\ d etai led
search or the wreckage a nd s urro undin g area fai led
to rind it. Examination o f the rracture s u rraces or
the re ma ini ng rr;:igments still attached to th e
ai rcraft indicated that the fairin g had bee n missin g
for some time.
Consider ation or th e ex pected ru el co ns1 1mprion
rate for the !light gives some in sight into the cause
o r the e ng in e fai lure. The aircraft ruel ga uge is
calibrated in po und s and this unit wi ll be used in
the following discussion. The total ca pacirr o f t he
aircrart 1·uel srstem is -t 12 pounds or Avtu r . In
!light , the pilot a nticipated a consum p tion rate o r
16-l pounds per hour at cru ise power seu in gs of 50
psi torque and 700 d egrees Celsius turbine o utlet
lernperature. Allowing abo rrt JO pounds ror gro und
running a nd hover. prior 10 d eparture. 1he total
expected endurance frorn th e aircraft r1re l S)'Stem
was 147 rni11 ut es.
T he pilot report ed t lrar he selected o n 1he
au xil iary fuel system l \\'O hours a fter d e parture. At
tir e planned ru el consu111 ption rate th is shotrl d ha,·e
left about 75 pounds o r rue! in the aircraft lank,
however, th e pilot reported that there was 150
pound s ir1dicaled a nd thi s readin g d id not cha nge
arler th e a u x iliary system was selected on. The
eng in e failed a bo u t 25 minut es la ter. T lris was
nearlr coincidental witlr th e cons umptio n o l' th e
to tal usable fuel in tir e aircraf't ta n k at t he
an ticipated consu m ption rate.
It is o11"io us 1 hat th e fuel remaining indication o f
150 pounds, r e ported by th e pilot, was incorrect
and the pilot was lulled int o a false sense o r secu r it y
when th e indication did not change afte r he
selected on th e a u xiliary r·ue l sys tem. He inte rpreted
th e static readin g or 150 pounds lo indicate that rhe
engin e was consum in g fuel at tire rat e it was bein g
de live r·ed . I 11 ran. it \\'as established after I he
accide nt that t he a u xi liarr rue! pumps had abou t 50
per cent more oulpur th a n th e engine fu el
COflS U 111 pt io n.
Fo llowing t his a nd t wo previous accidents in vo lving
Hug hes 5 00 he licopte rs st rlle rin g fuel starvation ,
the rnanufac tu re r was co ntacted to ascertain the
e ffect or losing the 1·uel ra n k ve nt fairing. Based 01 1
wind tunnel tests cond ucted ver\' early i11 th e
dC\'elopment of th e a ircraft it W~lS d et'errni11ed tha t,
witho ut the fairing, rhe cliffere nlial press ure across
the fue l cell bladder co uld be expected to cause it to
collapse as fu e l is draw n from the lank and wo L1ld
at so me point preve nt th e lloat arm o r th e hr e l le vel
send e r from dropping, thereby g ivin g an erro neo us
fue l re mai nin g incl ica~i o n . The r'na rw'rac turer
·
runher advised that beca use of the problem of
blockages to the ve nt t hey in t rod uced a
·~
Underside of the wreckage showing the location of the lower vent fairing
Close up view of the vent fairing fragments still attached to the
aircraft
The auxiliary fuel system which was fitted to the helicopter
Aviation Safety Digest 111 I 21
�modificatio n which adds anot her vent below rhe
1-ight hand door. This modification is not
mandatory and was not fitted to an y or the three
aircr aft involved i11 accidents in Australia.
:rhe fuel tank vent fairin g extends away from the
sk rn ol the a ircra ft a nd is a positive head device that
prevents the collapse of the bladder. The colla psed
bladder con di tio n ca n a lso arise if' the fu el ve nt
becomes clogged with mud 01· dirt, insect nests or
a ny other o bstruction. Tests conducted by t he
manul"actu re r proved , howe ver, that the entire fuel
su pply can still be cons umed except for abo ut the
last litre. The Dail y Inspection schedule requires
that the ven t fai1·ing be inspected to ens ure it is free
from obstructions. Although not specif.ica lly stated ,
s uch an inspectio n clear!}' implies that the fairing be
111 place a nd un damaged.
Frn111 the evidence available it is conclud ed that
during the !light under discussion the a uxilia ry fuel
system did not !'unction and the pilot did not detect
~his.' p<~rtl y because o r the incorrect f'ue l remaining
1nd1cat1 o ns. The incorrect fue l ind icatio ns resulted
f'rom the loss or the rue! tank \"e nt fa iring causing a
colla pse o l the a ircra ft fue l tan k.
Some o l" the facrors which combined to cause this
accide n t were :
Loss o f the fuel ,·ent fairing p r ior to this fli g ht
com mencing
Erroneo us fuel rema ini ng ind ica ti on
Fai lure of' the auxi li ary fuel syste m to s uppl y
tuel
Eng ine fai lure fo llowi ng rue! star \"atio n , O\'er
unsuitable ten-ain.
There we r e a number or ways that the acciden t
m ight have been a\'O ided :
Detection of the missing rue! \"e nt fa irin g
cl unn g the p re fl ig ht ins pectio n shou ld h;ne
resulted in the broken fairing being rep laced .
The loss o r the fairi ng in itself d id not
jeopardise the saf"e ty or the fli g ht, but the
incorrect f'uel indication whic h res ulted was a
factor in the accident.
Althoug h the reason for the a uxi li arr fuel
system fai ling to operate was not positi,·ely
d etern1ined, there is a high degree o r
probabilit)' tha t fai lure of the electrical cable
had occurred. Appro\'al of the a uxiliary l"uel
system would have ens ured that it was
prnperly restrained and that the wires
pro viding t he electrical powe r to t he p umps
vve re p roperl y routed and protected lo a void
damage.
More careru l mon iroring of' the f'u el
consumption should ha ve detected the e r ro r
in the rue! remaining ind icatio n. At the time
the au xiliary fue l system was selected on l here
was twice as much f'ue l remaining indicated as
there should ha ve been , a t the an ticipated
cons um pt io n rate of' the engine.
Better knowledge o f the au xiliary fuel system
capabil it y would ha ve allowed the detect io n or
the non-opera tion o f' the system which was
ca pable of' pro\' idi ng about 80 pounds o f· fu el
per hour more t ltan the engi ne cons umption
rate . By carefu ll y monito rin g the rue!
r emain in g gauge, a rter selecting o n the
auxiliary system, I he pilot sho u ld ha ve
detected that the rue! 1-cma ini ng ind ication
was not inc reasing. Th is wou ld have p ro \'ided
him with time to cond uct a precautio na r y
land ing be fore exp iration or the fue l rrom the
aircraft tank.
The main safety lesson of importance to pilots
and operators of Hughes 500 helicopters is to
ensure that the fuel tank vent fairing is free from
obstructions a nd undamaged, prior to flight.
Although not a mandatory modification , fitment of
the additional vent would appear to be a useful
safeguard. It could be argued that there is
inadequate emphasis in the various manuals of the
importance of the fairing, however, the very
inclusion of a specific check in the manuals
denotes some measure of importance.
Although th is accide 11t r e port concern s par ticu la r
compone n ts on a panicu lar ai rcra rt, l he lesso ns to
be learned app ly to all a ircra ft and all pilots. E ns11re
I ha t you kn ow a ll a bout the aircraf"r yo11 a re flying,
pa rti c1rlarl)' th ose items which are hig hlighted in its
operating instructio ns and manua ls, and thi nk
about wha t is happe ni ng a ll the time, not just
occas ionall y. Fin al ly, befo re making a ny selectio n o r
operatin g any control, consider the existin g
situatio n, ant ic ipate the changes that will occur and
e nsure that those changes do occu r. If not, seek out
the reaso n fo r an y variation
e
From the incident files
Lake LA-4 nose gear retraction
There have been several occurrences o ver the last
few years in volving a problem with Lh e re traction of
the nose gea r on the Lake amphibian. This aircraft
has a casto rin g, no n-steerable nose wh eel which
retracts forward in to a well. U nder no rmal
circumsta.n ces, and provided the shimm y dampe r is
not overtightened , the wheel alig ns itself
fore-a nd-afl during re traction. If, howeve r , this
does not occur a nd retraction is atte mp ted with the
22 I Aviation Safety Digest 111
wheel turned to the ex treme lefl o r ri gh t positio n, it
may ja m against th e wh eel well doo r.
T his extreme displacement prior to relraclion ,
altho u g h infreque nt, may occur wh en the aircraft.
enters the water fro m a beach or ra mp, pa rticularl y
if the hard sui-face is ro ug h. Pil ots should be aware
that th e situa tio n m ay a rise, a nd it is impo rtant tha t
use is made of the gear inspection mirror on th e ·
le ft hand float LO ensu 1·e tha l th e nosewheel is
alig ned fo re-a nd-aft be fore attempti ng retraction
e
Do you raise the flaps during the
landing roll?
Why?
T he re appears to be a rather widespread
misundersta ndi ng amongst general aviation pilots
abou t th e need o r o therwise to raise the flaps
during the landing roll. T oo man y pilots
automaLicall y raise them with out th inking abou t th e
need to d o so. ConsequenLly there a rc a number of
accidents reported in wh ich the pilot of a
retr acta ble land ing gear aircraft raised the gear
instead of the flaps.
T h is bad habit apparently begins d uring the
early training da ys on fixed gear aircraft and carries
on to more so p h isticated ty pes. During transition to
retractable gear aircraft the pilot who has develo ped
this h abit im mediately places the safety of Lhe
aircraft in j eopard y. Adel to this th e difference in
man ufacturers' cockpit la yo uts and the risk of an
accid ent becomes even greater .
The following brief report is a typical example
of the inadvertent gear retraction type of accident.
The p ilot h ad purchased a Beech 95 Travel Air
and p rio r to ta ki ng d elivery of it had arranged for
the necessa1·y endorsemen t tra ining. When this was
completed he flew the aircraft to a nearby
aerodrome LO fit a new batte r y and to refuel.
H e subm itted a flig h t plan for the retu rn trip
Lo his h ome base wh ich was a licensed aerodrome
with an 1100 m e tre sealed main run way. The flight
was with out incident and the pilot joined the circuit
Lo land o n the easterly run way. Prelancling checks
were completed a nd the aircr aft to uched clown with
full fla p selected.
T he pilot r eported that when the aircraft's
speed had r ed uced 'to about 30 knots, towa rds the
encl o r the landin g rol l' he leaned over to the ri ght
a nd 'witho ut thin king, flip ped the gear leve r up'.
He immediately realised what he had done,
however, the nosegea r colla psed , the propellers
contacted the run wa y and the a ircraft slid to a stop
on the nose sectio n and partly retracted main
wheels .
During th e inves tigation the pilot, who had
nearly I OOO hours experience, indicated Lhat during
his I 0 years ownership of a single e ngine, fixed
gear tailclragge r , he had developed the habit of
selecting the flaps up early on the la nding roll. The
pilot h ad subsequently flo wn a fe w hundred hours
on Piper twins befo1·e purchasing the Beech . Th e
flap and gear selecLOrs arc reve1·sed in these
a ircraft. H e ad mi tted th at during his endo rsement
o n the T r avel Air he had reached across to r etr acl
the fla ps o n the land ing roll but was in fact
1-eachi ng for the gear lever. The instruclor had
warned hini to pay more attention to what he was
doin g.
Examination of the r un way revealed th at th e
propellers first conlacted th e ta rmac 383 metres
fro m the th resh old a nd th e aii'craft stopped 165
meLres further on. Information gained during the
investigation of man y similar accidents suggests
that, from t.he distances in volved o n this occasion
the unintentional gear retraction more likely
occurred at a speed of 50-60 knots which is hardl y
near the end of the la nding roll.
It is obvious from the accidenl report that th e
pilot su ffered from too man y years precond itioning
to h ave avoided this accident. Unfortuna tely, the
~xpericnce during his endorsement training was
mad equate to overcome th is preconditioning.
To try and help pilots prevent this bad habiL from
developing, we shall look at the requirements for
landing per formance, the manner in which it is
delerminecl and the pr esentation o r Lhe landing
perfo rmance informatio n to the pilot.
Documentation
The re a r e basically three pu blications to which a
pilot m ay refer to obtain performance information
for the aircraft he is fl ying. These are :
The owner's manual
T he pilot's o perating handbook
T he fligh t manual
The owner 's manual a nd p ilot's operating
handbook are produced b y the aircraft
ma nufacturer. They include performance
information applicable to a n aircraft of the same
make a nd model, in good condition, flown by a test
pilot, using average piloting techniques. T h e
infor mation in th ese publications should be used
only as a g uide. The approved take-off and landing
information, together with the limitations applicable
to th e aircraft, and information on weight and
balance, a re con tained in the fligh t manual
produ ced by th e Department of Transp ort a nd
issued for each aircraft on Lhe Australian r egister.
It is a requirement of the Air Navigation
Regula tio ns that the fl ig h t manua l be ca JTied in the
aircraft at all times. Fro m the inform ation contained
in it a pilot can d etermine th e sui tability of an
aer odrom e fo r the operation of his aircraft, or the
maximum weigh t at which he can oper ate the
aircr a ft from a give n runway or strip.
Establishing the flight manual landing
performance
The la nd ing performance given in th e flight
manual is based upon the demonstrated
per fo rm ance of the aircr aft type. The technique
used in establis hing the landing distance is such that
the aircr aft is flown al a n app roach speed o f 1.3
times the stalling speed, in a glide, th rough th e 50
foot screen h eigh t above the runway th resh old.
After tou ch down, maxim um wh eel braking is used
to bring the aircraft to a stop. Rel raction of fla p is
not a llowed .
Aviation Safety Digest 11 1 / 23
�The landing weight chart is based on the use of
a short, dry grass surface bu t is also ap plicable to
sealed and gravel strips. The la nding performance
is demon strated fo r th e fu ll ra nge of a ircraft
weig ht , ambient tem pe rature, pressu re a ltitude ,
wind componen t a nd run way slop e.
After the land ing perfo rma nce has been
demon straLed it is factored by 1.1 5 for aircraft
2000 kg in weigh t a nd below, to 1.43 for aircraft
a bove 4500 kg, with li nea r va ri atio n in between.
The purpose or factoring th e d emonstrated
performa n ce info rmatio n is to allow for va ria tions
to be expected , becau se o f age a nd cond ition ,
betwee n aircraft of the sam e ma ke a nd model , a nd
varia tio ns in pilots' h a ndlin g Lech niques and
abilities.
Example of landing performance
We will use the la nding weigh t cha rt fo r the Beech
T ravel Air to illustraLe. The a pproxima te cond itio ns
pertaining a t the time of th e accide nt we re :
Pressu 1·e al titude
2000 feet
T em p era ture
20° Celsius
Aircraft weigh t
1600 kilograms
Wind compone n t
+ 5 kno ts
Run way slope
zero
. From the landing weigh t cha rt the landing
distance required is 490 metres. T he refore, o n th e
landing whe n the accident occurred, there was a
margin of 6 10 metres available. If we igno re th e
facto ring, the demonstrated landing d istance from
50 feet over the threshold to stop becomes
a pprox imately 425 metres, which p rov ides a ma rgin
of 675 me tres. If we go fu rth er a nd ass ume tha t th e
aircra ft was lo touch d own on the thresh old, th e
demonstra ted la nd ing distance wo uld be fu rth er
reduced. Q uite obvio usly, the p ilot h ad absolu tely
n o reaso n, on this la nding, Lo be concerned about
th e braking p er fo rmance of his airc ra ft consideri ng
the d istance ava ila ble in the condi tio ns p revailing,
a nd therefore had nothing to gain fro m retracti n g
th e flaps.
Manufacturers' recommendations on f lap
retraction
Examina tio n was made of th e owner's ma nua ls a nd
pilo t's ope ra ting ha ndbooks for a wide ran ge of
ge ne ral aviation a ircraft built by the three major
U.S. ma nufac tu rers. The reco mmen da tions for flap
retractio n on landi ng var y, both between d iffe re nt
ma kes a nd the differen t models produced by each
compa ny.
In general th e manu fac turers slate that the
flaps sh ould be ren·acted, afte r all wheels are o n th e
ground , wh en maxi mum bra kin g efficiency is
required. In th e majori ty of ma nuals there is no
require ment lo retract the flaps d uring a no r mal
landing, h owever, nearly all of th e m refer red to this
procedu re in short field la nd ings. We will d iscuss
sh ort field la nd ings later.
Some ma nuals went as fa r as reco mme nding
th at the fl a p sh ould no t be retracted u ntil the
aircraft had le ft the acti ve run way. Cessna su ggests
tha t, fo r the 3 10 a nd larger ai rcraft, 'the flap aids in
decelerating the aircra f"t', while Piper, in the Seneca
manu al, slates th at 'Lhis will avoid reaching fo r th e
gear ha ndle instead of th e fl ap h and le by mista ke,
24 I Aviation Safety Digest 111
and will permit full attention to be given Lo the
landing and landing roll'.
Short field landings
I n preparing th is article, co11side ratio11 was g ive n lo
the definition of a short field la nding. The
consensus of opinion was th at a short field landing
was one whe re the la nding dis tance ava ilable was
abou t th e sarne as the landi ng distance requ ired , in
the conditions prevailing. For example, fro m the
Beech T ravel Air landing pe rfo r mance chart, in
ISA conditions, nil win d and maxim um landing
weight o n a level ru nway, the landing d istance
required is again 490 metres. T his is considera bly
less tha n th e r unway length available at any gene ral
aviation or other gove rnmen t aerodrome, and the
vast major ity of licensed aerodromes and training
ALAs. H owever, a pilot is li kel y lo encounter strips
of su ch a short length a t oth er A LAs.
I t becomes obvious fro m the p receding
paragrap h th at a lot of p ilots in the general av iation
industry will be most u nlikel y lo need to op erate in
acco rdance with short field landing tech niques
durin g th eir no rmal op eratio ns. Wh e n it d oes
become necessary lo ope1·ate into a shol'l field , such
pilots sho uld ensure that their lech1'1ique is up lo
standa rd and thei1· fl ying is more accurate th an th at
needed to land on a 1500 metre sealed runwa y.
Recommendations
From the flight manual establis h the landing
d istance r equireme nt for th e wo rst conditio ns you
are like ly to encou nter. For instan ce at maximum
AUW for land ing, 30°C, 1000 feet AMSL a nd 5
knots tail wind, this d ista nce may be 700 metres. Fur
longer strips, lreat the land ing as normal. For
sh orter stri ps, firstl y double check the landin g
performa nce chart and if the strip length is abo ut
the same as th e land ing distance req uired, treat as a
short field lan d ing.
If flap retraction is considered to be necessary
after to uchdown prepare for it in the circuit. P la n
your actions, positively iden tify the flap lever and
recite th e p rocedure in you r min d . After
touchdown, again positively id entify th e flap lever
a fte r a ll wheels are on th e ground and on ly then
select th e fla ps up.
If" you do nol regularly fl y in to aerod romes
with short strips it ma y be advisable to unde rgo a
check r ide with an instructor before undertaking
su ch an op eratio n.
During trai ning, or a ch eck flight, get th e
ins tructor to ta ke you to an ALA with a short strip.
Six hundred metres of gravel strip looks
considerably differen t from I'.WO metres of grass or
sealed run wa y. You will gai n a fa r better
ap preciatio n of th e limits of you r own techniques
a nd abili ty if you p ractice al a suitable location , with
a n instructor wh o can correct a n y p roblems.
T h e la nd ing roll is not the time to be dividing
your atten tion between controlling th e aircraft a n d
conducting un important tasks. Leave your afte r
la nd ing checks until you have turn ed off the
run way and it is unli kely that yo u wi ll ma ke any
er roneous selectio ns e
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Aviation Safety Digest 111 I 25
�Unlocked seat - loss of control
during ground manoeuvring
A Cessna 180 agric ultural aircraft had been used
for seeding o perations a t a Quee n sland property.
On completion of th e d ar's f1 ying, the pilot la n d ed
al the stat ion st rip and p arked al th e north eastern
e nd . A fter a sh ort break , he intc 11dccl to tax i th e
aircraft abou t 500 ya rds alo n g th e s trip lo refu e l
and load some gea r prior to re wrning to his base.
Before entering Lhe aircraft, the pilot slid the scar
back Lo clear awa y so me seed from a round it a11d
th e rncldcr pedal area. He then slid the seal ful l)'
forward and cleared a\\'ay so me more seed fro m
undern eath it. The pilot mo ved th e seal rull y
backwards aga in , entered the coc kp it a11d adjusted
the scar to its norm al fore /a rt position. Beca use h e
was o nl y intending ro taxi a sh ort dis tance h e did
not ch eck that th e sea l a cijust men L h ad locked
correct!)'.
Af"ler startin g the eng ine, the pilot turned the
aircra f°L sh a 1-ply Lo rhe rig h t using about half thmttle
and rig-ht brake. As it lin ed up 0 11 th e strip th e pil o t
a pplie~I ha rd le ft brake Lo sto p the a ircra fL turn ing
runhcr, at ll' h ich time h is sea t slid bac k\\'ards.
U nder the infl u ence o r the high power seuing
and the wind co m in g r·ro m the lef"L. th e a ircraft
s\\' u11 g hack across the st rip. T h e pilot struggled to
pu ll hi 111sc lf up but befo re he cou ld o pera te the
throttle or m ixture controls th e ai rcra ft was sliding
side\\'a ys a long t h e su·ip. The ri ght han d la nd ing
gea r struck a mou nd a11d fo ld ed umle1· the
fuselag e . Afte r the a ircr aft s lid to a slop o n its ri gh t
h and sid<>. th e pilo t 1urncd off th e fu el a 11d
elccrrics, and cvacuaLed th e cockpit. The aircraft
suffe red considerable da mage.
Subseq u e nL i11sp ect io 11 or th e airc r:1ft revealed 110
defects in the scat adjus1111c111 rnecl 1a n isrn. and it
was concluded Lhat th e rn eclta nis111 had 1101 bee n
properly e n gaged.
A11r com111e ut neecled?e
Note: Some of our readers may be confused by the fact that, in spite of the substantial d amage suffered by the aircraft, this occurrence was
classified as an incident rather than an accident. As defined in the Air Navigation Regulations, an accident can only occur when persons
have boarded an aircraft 'with the intention of flight'. Because the pilot of this Cessna 180 was merely repositioning the aircraft along the
strip, the occurrence was classified as an incident.
26 I Aviation Safety Digest 111
Flight through restricted areas
Don't spoil your
day!
Pilots who ignore
Restricted Areas
could be in for a
nasty surprise~
Some or ou r read ers will remember the poster h·orn
A11111li1111 So/i·ty Dige.1/ 87 . T h e message it contained
related to ·a i1:c ral"t entering restricted a irspace ll'he n
l here was gu1111c r y p ract ice in progress. Fort 11 na rely, to
date no airu-af"t h as been da111aged 111 Australia
beca use or t hi s, 111ai11 h· because ol" t he l'igilance or the
r an ge sa k ty o ffice rs .in charge c~r· firing, ll'ho ha\'e
called ro r a check !'ire unt il t he 1n tr11der passed .
111 1979 t h ere were '.21 reported cases oraircrart
enterin g reslr iu ccl a reas associa ted with ground. !'iri ng
or g uns a nd exp losives. Or these,.] g rcs.ultcd Ill
su bsequen t ide n tiricatio11 or the a1.rcraft ~11 \'0 l vecl b ut
the re 111aini1w eight re111ai 11ed u11 1clen1 ii 1ecl . The
un fort una re 1~a r1 'about fail ing to iclenriry t hcse ain:rart
is 1hat the offe n de r p robably rema ins unaware o l the
da1we
..., r ro whic h he ex posed hi111selr, his passengers
a nd the aircral"r.
A n al\'sis or I hose incidents i11 ll'hich the ai1-crart \\'<IS
icle nti fi~cl did 11ot r eveal an y cases ol'blata n t disregard
or sa l'el)·; ra th er, t he)' re,·ea led a derinitc lack o[
u nd e rsta nd ing by the pilot ol'Lhe risk in volved a nd the
way in w h ich th a t risk could ha,·e been avo ided. In
so me cases, this unnecessary exposure to risk was .
ca 11sed by t h e use or incorrect or outdated charts.; 111
o lhc r cases a lack of adequate preflight preparauon;
while others involved inaccurate navigation .
Jn rnosl cases, prevention is the answer and t his can
be achieved by acleq uale preflight preparation. When
p lann in g the [light, check l h e route o.n the a1?propnate
RNC or \/ EC, and ascertai n the prox 11rnt y ot 1·estnncd
airspace . Ref"er to the A I P En Rou le Supplement
section o n l' rohibiLecl, Restricted and Danger Areas
for details Oil vertical limits and hours or operatio n of
the appropriate area. l fthe area activiLy is not~fied by
Notam e11surc that you request the 111format1011 at.
briefing, or, ir this is no t possible , in fl ight by rac~10
whe n approaching the rcstricLcd arc.a. Whe n plann mg
an alternative route, because the direct track passes
through an active a rea , ensure thal you plan via easil y
identiriab le check points that will ensure an adequate
margin for navigatio n al error. .
.
.
H yo u find that yo11 are hav1n~ nangallonal.
di ITiculties in the vici nit v of a rcslnctecl area, ad v1se l he
ATC or FS station yo11 a.re wo1·kingat that time. It 1m~y
be possible Lo have t he ground firing stopped unlll
your positio n is identiried as safely cle.ar ot. 1~ 1 ~ area. lL
wou ld be most undesirable to be the l 1rst CJ \'tl1an pilot
i11 Austral ia to be shot clown by ground tire in a
restricted area .
Four oflhe u nidenriried inrrnsions during 1979 are
described be lO\\'. Were you one or the pilots i11\·olvecl?
On 2--l- February, ar I 050 hours loca l. a blue and
ll'h ite Cessna type \\«ts obsen·cd Lo fl y from sou l h west
to north cast t hrough Restricted Area 5:38D
(Singleton, NSW). -fhe a rea \\"<..ts active 11p to 9?00f~cl.
A check fire was gi,·en immediately to all u1 11Ls finng
on the ran<Te as the aircraft was in danger.
On 27 :-.t1rch , at 1610 ho11rs local, a sih-cr, single
engine, rixecl undercarriage, high wing aircrai"L ll«lS
ob~en·ecl lw the range sarety ollicer ro tl y through
Restricted Area 259A (l'orl Wakcf"ielcl, S .A.) ll'hile
l'irino- 11·as in progress.
0171 s J\ 1wusr, ~t 11 --l-8 hours local, the range safet)'
ollicer rep01°ted that a Piper-t ype airc raft , white ll'ith a
red stri1)e and h eaclinotowards :\1l oorabbi11 , had .
t>
passed through Restricted Area 3'.29 (West Head , ~ 1c.)
011 19 September, at 0922 hours local, a greyish
white ,.si1wle
e1wine
ai rcraft ll'as observed al abou t 200
t>
n
feet AGL o n a northerly head i11g o \·crthe range at l he
southern end of Restricted Area 635 (Greenbank,
Q lcl. )
.
.
II' vou were the pilot-in-command ol a n~· ot these
aircr;1fr rou can be thankful that the range safety
officer i;1 eac h case performed his cl 11ties with the
necessary degree of"vigi lance, because it is olwio1.1s t ha1
the p ilor did not. Ir yo u want to a\'oid t h e risk o! bcmg
hit by groundfire, be alert for active restricted a reas e
Aviation Safety Digest 111 I 27
�Flight safety - a team effort
The whole purpose of compiling a flight plan is frustrated unless several criteria are satisfied.
Important among these are the pilot's knowledge of the obligations and limitations of his licence,
adequate monitoring of the flight progress, and careful attention by Departmental officers to their
duties. An incident which occurred some months ago included breakdowns in the areas mentioned
above. Fortunately it also included a measure of luck which prevented the incident from becoming an
accident.
T he p ilot pla nned the flight in a Cessna 3 I 0 rrom
Albur)' to Adelaide via a propert)' in north western
NSW a nd Broken Hill. The flight was planned
throughou t as p rivate categor)' in accordance with
th e V isual F light Rul es. Th e pilot held a Pri vate
P ilot Licence without an instrum ent ratinr,-.
Th e on l)' d eviation from plan on the first two
sectors occuned wh en th e pil ot had some difficulty
locating the sta tion properl)'. This added an extra
30 minutes to the flight. Late r iu th e afte rnoon he
flew to anothe r property nearby, took 011 about I 35
litres of ruel f"rom a drum , a nd d e parted for
Broke n H ill.
The re was some d ifficult y in obtaining ruel m
Broken Hill , but fin a lly th e pilot was able to
a rran ge for 150 litres to be added to the aircraft.
Th is was the maximum allowed to the pilot beca use
of the s hortage of A vgas. He estimated that this
wo uld give him a total or about 230 litres which
would be just sufficienr for th e ni ght to /\clelaicle
plus 45 minutes fi xed rese rve. While the aircrart
was being re fu e lled the pilot attended the Briefing
Office. Adela ide a t tha r ti me was closed Lo VFR
operations and required 30 minutes holcli11g fuel
hecause of th e forecast. As it was late in the
afte rnoon , the pil ot d ecided Lo re ma in overnight at
Broke n H ill.
The nex t mo rnin g the pilot again attended the
Briefing Office. Curre nt area and te rmin al forecasts
we re dis p la)'ed , which indica ted that, ll"hile the
weather wo uld be suitable for V FR flig ht at first, it
would deteriorate be low VMC towa rds Adelaide.
The TAF for Adelaide required 30 minutes h olding
fuel because of periods of reduced visibility in
heav)' showers and low cloud. The pilot checked th e
ARFORs but apparently did not check the T AF. He
submiued a plan u tilising the same time intervals
which he had planned and submiued a t Albur r the
previous morning.
In planning th e flight , the pi lot had used the:
RN C a nd RTC, and had omitted the 28 nautical
mile segment between Morga n and Stonefield
throug h misinte rp re tation or the information on the
charts. This om ission , a nd the use of winds of lesser
strengt h than inclirn tecl on the ARFORs, resulted in
a total p lanned 1i me interval about 15 minu tes less
th an it sho uld ha ve been.
T he fli ght departed c,1 1Tying only four min utes
fuel margin over the erroneous fligh t time inte r va l
plus 4 5 min u tes fi xed reserve. The Departmenta l
officer accepting th e plan misread the tot.a l
enduran ce figu re and d id not recognise th e fact
that the aircra ft was not ca rrying the 30 min utes
holding required b)' the Ad ela id e forecast, nor the
alterna te or 30 minutes holding req uired for a VFR
fl igh t p la nned LO em er a ca pital cit)' primar )' control
zone.
As the flight progressed , the pilot dedu ced that
28 I Aviation Safety Digest 111
the wind was diffe re nt from that used fo r the plan.
This was because the ai1·cra ft was abou t 11 minutes
late at Stonefield , which he concluded was beca use
of much stronger winds tha n forecasl. B)' this time
the weather had de te rio rated as predicted. The
pilot e ntered cloud a r 3500 feel afte1· passing
Stonefield , a nd the n adv ised Adela ide Fligh t Ser vice
that he had insufficie nt f"uel to retain his reserves
intact. He did not reall y consider d iversion to
suita ble VFR a lternati ves such as Waike rie or
Renma rk because o f" the d ifficult)' with fu el supplies
there, and also because h e wan ted to get 10
Adelaide. Approach Control ini tiall y re f"used a
clea ra nce request from Flight Service because VMC
did no t exist o n the planned track, however, after
being advised of the aircraft's low fu el situatio n , a
clearan ce was passed to enter cont rolled airspace
and to expect radar vectoring.
Shortly after establishing con tact with Ade laide
Approach Control , the pilot indica ted that h e was
having trouble avo iding cloud . The aircraft was
rad a r vectored and descended north of th e f"icld
unti l it beca me visua l a t abo ut 1700 feet. lt was
unknown to the Adelaid e contro llers that durin g
the descent the aircraft was operatin g in cloud with
the autopilot engaged .
The pilot realised just how far he had go ue in to
his reserves whe n the ri ght e11gin c stopped through
f"uel exhau stion just af"ter the ai rcraft had vacated
the landing runll"a)'. At that tim e the ri ght fue l
gau ge indicat ed approximatel y I 0 litres and th e lef"t
gauge appro ximat e ly 30 li tres.
During th e i11ves tigatjo11 o r this incidem , it
becam e apparen t that the pilot gave ve ry little
attention to the forecast weather and his flight
p lanning. Even \\' ith the margina l fu e l for the fli ght
as he plann ed it, h e d id no1 ascert ain th e actual
a rnount of fue l on board. He d isplayed a lack or
knowle d ge concernin g fuel require me nt s and the
ru les of th e a ir affeuing aircn1ft 011 VFR fligh1 s.
The pil ot a lso revealed that h e had made a sirni lar
d escent throug h cloud some months earlier. \i\li1h a
total instrumen l fli ght time of five h ours gained
du rin g his licence tra ining, a nd 110 instrumen t
rating, iris probabl r ve r )' fo rtuna te that the p ilot
bad a serviceable autopi lot t<> use, oth erwise the
res ults may have been different.
The investi gation also revealed that Deparrmen ta l
personnel did not recognise the inadequate ruel
figures indicated h)' the pilot 011 his fli gh t plan .
Flig ht safct )' is th e res ponsibilit)' of ever ybod)'
within the industr)'. Conscie ntious atte miuu to his
direct area o f respo nsibilit)' by each pe rson shou ld
e nsure complete sa fet y, however , whe n individual
c nors occur a nd a re not picked up b)' the
monitoring system . they compound LO the extent
where safet)' is quick! )' co1uprom ised
e
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Aviation Safety Digest 111 I 29
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Boeing 767 - 200 cover illustration
(reversed for the purpose of 1ayou1.)
In which category do you receive the Aviation Safety Digest?
Basic aircraft specification
Power plant: Two Pratt and Whitney JT9D-7R4D turbofans rated at 21 656 kgp (47 700 lbs).
Fuel capacity· 58 895 1(medium range option 42 846 I) in integral wing tanks.
Performance: Max operating speed 0.86 mach : max cruising speed 506 kts at 30 OOO ft : long range cruise 459 kts at 39 OOO ft. Range
with 211 passengers, 2740 nm at O 8 mach
Weights Operating weight 81 856 kg: max payload 30 708 kg; max zero fuel weight 112 592 kg; max take-off weight 136 200 kg; max
landing weight 122 580 kg
Dimensions: Wingspan 47.65 m· overall length 48.5 m; overall height 15.85 m: aspect ratio 8.7 to 1; sweepback 31.5 deg.;
undercarriage track 9.29 m
Accommodation: Two pilots plus optional third crew: typical mixed passenger accommodation 18 six-abreast first class plus 193
seven-abreast economy; max one-class 255 seven-abreast. Underfloor cargo hold 22 containers and 12.18m3 bulk cargo.
Comments:
Cutaway drawing key
I ,_
r.
I
1 Radome
2 Radar scanner dish
3 VOA/Localiser aerial
4 Front pressure bulkhead
5 ILS glidescope aerials
6 Windscreen wipers
7 Windscreen panels
8 Instrument panel shroud
9 Rudder pedals
1O Nosewheel bay
11 Cockpit air conditioning duct
12 Captain's seat
13 Opening cockpit side
14 Centre console
15 First officer's seat
16 Cockpit-roof systems control panels
17 Flight engineer's station
18 Observer's seat
19 Pilot tubes
20 Angle of attack probe
21 Nosewheel steering jacks
22 Twin nosewheels
23 Nosewheel doors
24 Waste system vacuum tank
25 Forward toilet compartment
26 Crew wardrobe
27 Forward galley
28 Starboard overhead sliding door
29 Entry lobby
30 Cabin divider
31 Port entry door
32 Door control handle
33 Escape chute stowage
34 Underfloor electronics racks
35 Electronics cooling air system
36 Skin heat exchanger
37 Fuselage construction
38 Cabin window panel
39 Six-abreast first class seating
40 Overhead stowage bins
41 Curtained cabin divider
42 Sidewall trim panels
43 Negative pressure relief valves
44 Forward freight door
45 Forward underfloor freight hold
46 LD-2 cargo containers, 12 in forward
hold
47 Centre electronics rack
48 Anti-collision light
49 Cabin roof frames
50 VHF aerial
51 Seven-abreast tourist class seating
52 Conditioned air riser
53 Air conditioning distribution manifolds
54 Wing spar centre section carry-through
55 Floor beam construction
56 Overhead air conditioning ducting
57 Front spar/fuselage main frame
58 Starboard emergency exit window
59 Starboard wing integral fuel tank
60 Thrust reverser cascade door, open
61 Starboard engine nacelle
62 Nacelle pylon
63 Fixed portion of leading edge
64 Leading edge slat segments, open
65 Slat drive shaft
66 Rotary actuators
67 Fuel system piping
68 Fuel venting channels
69 Vent surge lank
70 Starboard navigation light (green)
71 Anti-collision light (red)
72 Tail navigation strobe light (white)
73 Static dischargers
74 Starboard outer aileron
75 Aileron hydraulic jacks
76 Single slotted outer flap. down
77 Flap hinge fairings
78 Flap hinge control links
79 Outboard spoilers. open
80 Spoiler hydraulic jacks
81 Rotary actuator
82 Flap drive shaft
83 Aileron hydraulic jacks
84 Inboard aileron
85 Inboard double slotted flap, down
86 Flap hinge control linkage
87 Fuselage centre section construction
88 Mid-cabin toilet compartments
89 Cabin attendant's folding seat
90 Port emergency exit window
91 Ventral air conditioning plant
92 Mainwheel doors
93 Door iack
94 Wheel bay pressure bulkhead
95 Starboard wheel bay hydraulic reservoir
96 Rear spar/fuselage main frame
97 Pressure floor above wheel bay
98 Cabin floor panels
99 Seat mounting rails
100 Overhead stowage bins
101 Cabin roof lighting panels
102 Centre stowage bins
103 VOA aerials
104 Fuselage skin plating
105 Negative pressure relief valves
106 Rear freight door
107 Seven-abreast tourist class seating
108 Rear toilet compartments
109 Cabin attendant's folding seat
11 O Rear galleys
111 Overhead sliding door counterbalance
112 Rear pressure dome
113 Fin root fillet
114 Tailfin construction
115 Fin 'logo' spotlight
116 Starboard tailplane
117 Leading edge HF aerial
118 HF aerial coupler
119 Television aerial
120 Fin tip aerial fairing
121 Tail VOA aerials
122 Static dischargers
123 Rudder
124 Rudder hydraulic jacks
125 Balance weights
126 Rudder honeycomb construction
127 Tailplane centre section
128 APU intake plenum
129 Gas turbine auxiliary power unit (APU)
130 T ailcone
131 APU exhaust
132 Port elevator
133 Elevator hydraulic jacks
134 Honeycomb control construction
135 Static dischargers
136 Tailplane construction
137 Fin 'logo· spotlight
138 Tailplane sealing plate
139 Fin attachment frames
140 Tailplane trim control jack
141 Rear fuselage construction
142 Port rear galley unit
143 Curtained cabin divider
144 Door operating handle
145 Rear entry door
146 Pressurisation outflow valve
147 Bulk cargo door
148 Rear underfloor freight hold
149 Air turbine driven hydraulic pump
150 Trailing edge wing root fillet
151 Inboard flap rotary actuator
152 Inboard double slotted flap
153 Main landing gear mounting beam
154 Retraction jack
155 Inboard spoilers
156 Flap hinge control link
157 Hinge link fairing
158 Port inner aileron
159 Flap 'down' position
160 Outer single slotted flap
161 Outboard spoilers
162 Flap hinge link fairings
163 Honeycomb control construction
164 Port outer aileron
165 Tail navigation strobe light (white)
166 Anti-collision light (red)
167 Port navigation light
168 Port vent surge tank
169 Rear spar
170 Wing rib construction
171 Front spar
172 Leading edge slat segments
173 Slat guide rails
174 Rotary actuators
175 Slat operating links
176 Pressure refuelling connectors
177 Port wing integral fuel tank
178 Wing stringers
179 Wing skin plating
180 Four-wheel main undercarriage bogie
181 Mainwheel leg
182 Undercarriage leg side struts
183 Port wing dry bay
184 Inboard auxiliary fuel tank
185 Engine bleed air ducting
186 Slat drive motor
187 Landing arid taxiing lamps
188 Inboard leading edge slat
189 Slat open position
190 Port engine cowlings
191 Intake de-icing air duct
192 Port engine intake
193 Pratt & Whitney JT9D-7R4 turbofan
194 Engine mounting pylon
195 Oil tank
196 Fan air exhaust duct
197 Hot stream exhaust nozzle
30 I Aviation Safety Digest 111
Aviation Safety Digest 111 I 31
�
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111
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1980
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https://collections.heritageoftheair.org.au/files/original/4c34f3d4e3fcc020983ac20302cc7a2f
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Text
110/1980
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Department of Transport
••
�Contents
3
Beware of dehydration
An inexperienced pilot set out to fly from Adelaide to Torn Price
with an overnight stop at Kalgoorlie. On the second day she twice
became lost and, during an unplanned landing, overturned the
aircraft. It became apparent that she was suffering from the
effects of dehydration.
5
Visits to Airways Operations units
6
Tie-down sense
Some points to remember when securing your aircraft after flight.
9
The flight recorder system
13 In brief
A variation on Murphy's Law
14 How to plan a crash landing
A successful landing at Christchurch, N.Z. of a USAF C-141
Starlifter concluded a well-managed, seven hour operation after
the landing gear was damaged on take-off from McMurdo,
Antarctica.
16 Unnecessary distraction - wheels up landing
Poor operating habits developed to save time in his charter flying
business led a pilot to omit to extend the landing gear.
18 The Engine Doctor and density altitude
21 Controls locked - remove before flight
Failure to remove the control column lock in a Beech Baron led
to a fatal accident.
23 In brief
The pilot of a Cessna 172, attempting a take-off before first light,
lost control of the aircraft as the result of lack of visual reference.
24 DC-9 lands short of runway
During an ILS approach in heavy rain an Australian DC-9 touched
down short of the runway at Melbourne Airport.
28 From the incident files
Three incident reports from the Air Safety Investigation Branch
files.
29 Survey of accidents to Australian civil aircraft
1978
Beware of dehydration
Aviation Safety Digest is prepared in the Air Safety Investigation
Branch and published for the Department of Transport through the
Australian Government Publishing Service, in pursuance of Regulation 283 of the Air Navigation Regulations. It is distributed by the
Department free of charge to Australian licence holders (except
student pilots), registered aircraft owners, and certain other persons
and organisations having a vested operational interest in Australian
civil aviation.
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries should be addressed to the Assistant Director (Sales and Distribution), Australian
Government Publishing Service, P. 0. Box 84, Canberra, ACT 2600.
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
Change of address and distribution enquiries;'
Subscribers should contact the Australian Government
Publishing Service at the above address.
Readers on the free distribution list should contact
The Publications Distribution Officer
Department of Transport
P.O. Box 18390, Melbourne, Victoria 3001
© Commonwealth of Australia 1980. The contents of this publication
may not be reproduced in whole or in part, without the written authority of the Department of Transport. Where material is indicated to be
extracted from or based on another publication, the authority of the
originator should be sought. The views expressed by persons or
bodies in articles reproduced in the Aviation Safety Digest from other
sources are not necessarily those of the Department.
Reader contributions and correspondence on articles should be
addressed to:
The Assistant Secretary (Air Safety Investigation),
Department of Transport,
P.O. Box 18390, Melbourne, Victoria 3001.
RM77/30217(6) Cat. No. 79 92679
Printed by Ruskin Press, 552-566 Victoria Street, North Melbourne,
Victoria.
Note: Metric units are used except for airspeed and wind speed
which are given in knots; and for elevation, height and altitude where
measurements are given in feet.
Cover
Water-colour by Peter Connor.
Editor's note
Photographers and artists amongst our readers are invited to submit material suitable for the cover?' the Aviation Safety
Digest. Illustrations of modern general aviation or airline activities will be favoured . Credits will be given for any
photographs or artwork selected for reproduction.
2 / Aviation Safety Digest 110
While stud ying for a Commercia l Pilot licence, the
pilot acce pted the opportunity to ferry a Cessna 210
a ircraft fro m Adelaide to Tom Price, in north western
Australia . Although relativel y inexperie nced , with
less than 150 h o urs total flight time, she saw this as a
cha nce to build up her fl ying hours.
The flight was p lanned for m id November, with
refuelling stops at Cedu na, Kalgoorlie a nd
Meekatharra, remaining overn ight at Kalgoorlie. The
first da y's !lying was completed without incident,
a lthoug h th e p ilot did esta blish that the rad io compass
was unserviceable a nd sh e was required LO navigate by
DR and visual reference. O n arri val at Kalgoorlie the
pilot arra nged LO refuel rhe a i1·c1·a ft at 0730 hours the
next morning .
She sp e nt the night in a hotel and early next
morning , when she we nt for breakfast, sh e was told
that, because of a powe r strike, breakfast would not
be availa ble until 0800 hours. Rather tha n disrupt the
refuelling an-angements, the pilot chose to have on ly
a cup o f tea and th en we nt to the airport.
The a ircraft was refu e lled and departed Kalgoo rlie
just afte r 0900 h ou rs. The pilot had not obtained an y
furth e r food or drink a nd there was neithe1· ra tions
nor wa ter on board the aircra ft. Afte r an uneventful
fligh t of about two and a half hou rs, the a ircra ft
landed at Mee ka tharra. Less than a n hour later it had
been refud l ~d and departed for the fin a l leg to T o m
Price. No refreshments were obtained by the pilot a t
Meeka tha rra.
Shortly after La ke-off, the pilot realised that sh e h ad
made an errnr of l 00 d egr ees o n the flight p lan ned
track (248 instead of 348) so sh e a ltered the aircraft
heading by th e same a mount. The p ilot did not realise
a t the time, however , th at a pplication of the forecast
wind of 090/ 15 to the correct track did no t produce
the sam e amou nt of cha nge to th e heading. As a
resul t th e aircraft was seve n d egr ees left of the correct
h eading. The exp ected grou ndsp eed had also been
reduced below th e flight p la nned figure.
The first ch eckpoint, 1 I 0 nautica l miles a long the
route, was a homestead in relative feature less terrain .
T his was missed and the pilot, believing the aircraft to
be r igh t of track , a ltered h eading 12 degrees to the
le ft. At 1350 h ours, whe n sh e estima ted th e a ircra ft to
be 30 miles from Paraburdoo, the pilot broad cast a n
'a ll stations' ca ll which was received by another
a ircra ft dep a rting from tha t location.
By this time the pilot of the Cessna 210 had become
quite un sure of he r position. Because of poor
commun ications, the othe r aircraft acted as a relay for
messages to Port Hed la nd Fligh t Service Unit. The
combined efforts of Airways Ope rations a nd the
other p ilot were unable to fix th e position of th e
Cessna. At 15 18 ho urs, afte r the d eclaration o f an
Alert phase, the pilot was instructed to land at a
sta tion strip sh e h ad bee n circling.
After a successfu l landing th e pilot reported th a t
she was a t a h omestead about 80 miles west o f
Paraburdoo. Because accommodation was conside red
to be unsu itable the pilot d ecided to fl y to Paraburdoo
be fore last light. Sh e dra nk half a cup of brackish
water wh ile flig ht planning a nd th en d e par ted at
a bout 1700 hours.
Ther e we re thunderstorms in the a rea a nd about
fo ur oktas clo ud cover , the sh adow of which mad e
navigatio n difficult. Ha lf a n hour a fter de parture, a t
the ETA for Para bur doo , the p ilot again became lost
Aviation Safety Digest 11 O I 3
�r
but could see a homestead below. A Distress phase was
evaporation from the skin and lungs. These normal
losses are balanced by drinking water. It is only when
declared and about 20 minutes later the pilot reported
that because the aircraft was low on fuel she was
the losses are greater than the intake that dehydration
occurs.
landing at the station strip.
The symptoms of d eh ydration include headache,
The aircraft was flown about 30 knots fast on the
weakness, drowsiness, nausea and impaired vision.
approach and ultimately touched down about half
Speaking distinctly and movement of any kind may
way along the 730 metre strip. Heavy braking was
applied but the aircraft ran off the end and
seem to require great effort. Water loss amounting to
only two per cent of body weigh t (about a litre) will
overturned in a ditch. The pilot, fortunately, was
cause symptoms. A significant salt loss with
uninjured. The accident had occurred at a station
deh ydration can result in muscular cramps anywhere
about 50 miles south west of Paraburdoo.
in the body. The condition known as heat exhaustion
After the accident the pilot was taken to the
is a state of collapse brought about by insufficient
homestead where she consumed a large quantity of
blood supply to the brain, following a period of heat
water. A commercial pilot who was there considered
stress. Heat exhaustion can occur at water losses as
her to be 'all in'. She was very distressed and
self-critical about the fact that she had twice becom e
low as six p er cel1l of body weight.
The association of flying and deh ydration is based
lost.
partially upon the exposure of the human body to
It was obvious from the circumstances of the flight
lowered atmospheric pressures. When the
and the accident, and the condition of the pilot, that
atmospheric pressure decreases, water evaporates
she suffered from the effects of dehydration.
from the body al a higher rate. Rates of loss have been
Symptoms to be expected with dehydration include
studied at various altitudes and, even at cabin
extreme thirst, headache, dizziness and
disorientation. Navigational difficulties, fatigue and
pressures of 5-10 OOO feet, evaporation is significantly
increased. U nder normal operating circumstances
the apprehension experienced by the pilot would be
this loss is small, but under condition$ of prolonged
related to that condition.
flight the loss becomes very significant in the absence
The tern perature at the accident site at about 1800
hours was 36 degrees Celsius so it can be assumed that of adequate water replacement. This loss will be
greatly increased if cabin temperatures are high or if
through the day the temperature must have reached
the atmosphere is particularly d ry - as it is at
at least 40 degrees. It is probable that the cockpit of
altitude.
the aircraft was even hotter because of the 'green
Individual tolerance to dehydration varies,
house' effect.
At rest, with an ambient temperature of 40 d egrees, although it is a well established fact that n o one can
live much beyond three days without water. No pilot
a person can expect to lose 3.26 kilograms per day as
should attempt to fl y an aircraft directly after any
the result of sweat loss. Authorities agree that, for
prolonged activity in the sun th at may have h ad
survival in arid areas with an average daytime
deh ydrating consequences. Even wh ere no obvious
temperature in excess of 32 degrees, the body needs
debilitating effects appear, a loss of menta l initiative
four litres of water per day. This is considerably in
can be exp ected, and this is not a good frame of mind
excess of the cup of tea and half a cup of brackish
water consumed by the pilot on the day of the
for safe flying.
It is recommended that you incorporate th e
accident. It is probable that her water consumption on
following items into your flight planning for this and
the previous day was also well below the required
every other Australian summer, or when flying in the
amount.
hot, dry conditions which can be e ncountered in
Dehydration
outback areas even during the winter:
Dehydration is a severe imbalance of the wa ter
• Maintain a high body fluid level by regular intake
content of the human system - a common, but not
of suitable liquids. This can be supplemented by
usu ally serious, summer complaint for most people.
taking along a thermos of cool water in the aircraft
However, for pilots who fly in spite of feeling
and drinking frequently. Cool water is preferable
obviously below par, dehydration can impair flight
to iced water as it is easier to drink. The body
performance to the extent that a serious accident can
effecti vely loses more h eat by warming the cool
result.
water to body temperature. Realise that you lose
Land animals evolved from water dwelling
moisture constantly when you are out in the sun or
creatures and in that evolution retained the water
warm air, even when you are unaware of sweating.
environment but c'nclosed it within the skin. The
• Use normal salt with your meals, but check with a
human body is over 60 per cent water by weight;
doctor before taking salt pills. Some people have
about seven per cent of the total body water is u tilised
bad reactions to them. Extra salt is seldom required
as circulating fluid (blood plasma), with 33 per cent
unless the individual is engaged in heavy manu a l
bathing the body cells and 60 per cent contained
labour in the sun.
within the cells. We are dependent upon this fluid for • Recognise that caffeinated drinks (tea, coffee,
all physiological functions; food and oxygen are
cola) tend to stimulate loss of water.
dissolved and carried to the cells, waste products are
• Avoid letting your aircraft cockpit be turned into
carried away, and the very ch e mical reactions of life
an oven by the sun. If you are unable to park it in a
itself occur in water solution. This body of water is not
hangar or in the shad e, try to cover the upper
static. T h ere is a constant flow from the cells into the
windows with a tarpaulin .
• Take time to open air ve nts before taxying.
body and back, as well as exchange of water with the
• Be aware that d eh ydration can be accelerated by
environment. The body takes adva ntage of normal
p re-fligh t activities - for example, it may well
losses of water to the outside world for elimination of
overtake a pilot in flight after a day's fishing in a n
wastes by way of the kidneys, and for cooling by
4 I Aviation Safety Digest 110
•
·•
T hi s boundary is identical with
Western boundary of CTA.
l
ISA
I
~··
Fl i.ght through these corridors shall be
made within s ight of the railw ay o r
highway concerned but in no case
more than five mi les therefrom .
HOBART
open boat, if water loss has n ot been replaced.
Vigorous exercise in h ot weather also speeds up
the loss of water tremendously. The sweat rate of
men doing h eavy work or playing a hard game of
sport under ver y hot conditions can be over two
litres per hour, and the con current salt loss may be
equivalent to a normal day's intake.
It was extremely fortunate for this pilot that the
accident occu rred on a property with help close at
hand. If sh e had been forced down away from
civilisation it is extremely doubtful that, in her
condition and lacking any supply of wa ter, she cou ld
have survived until a rescue party arrived.
The AIP VFG discusses the requirements
applicable to flight in designated remote areas.
However, it is not only in these designated areas that
h azardous conditions and situations can be
encountered. Befor e underta king-any such operation
be sure that you are mentally and physically
prepared. Read up on survival and ensure that you
carry adequate food and rations for the occupants of
the a ircraft until help arrives, in the case of an
emergency. Seek guidance from experienced
personnel if you are unsure of the safe way to embark
upon your trip . Ensure that you maintain an
adequate fluid intake to retain your mental processes
at a peak. If you do this you will be less likely to finish
up in a survival situation.
Although not through a Designated Remote Area
the planned route was over arid, sparsely inhabited
country. Planning for this flight should have
obviously included conside r ation of the n ormal needs
for food and water as well as preparation for the
possibility of a survival situation arising. •
Visits to Airways Operations units
~~e. Dep~rtment .regularly receive.s letters from members of the aviation industry wh o are interested in
v1s1tmg Air TraffIC Control and Fhght Service units to learn more about their functions. Visits to u n its
appropriate to the individual's normal area of operations are encouraged. To arra nge such visits interested
persons should contact the Superintendent of Airways Operations at the applicable regional office of the
Department of Transport, or the officer in charge of the specific unit he wishes to visit •
Aviation Safety Digest 110 I 5
�T
Tie-down sense
Each year aircraft are needlessly damaged by high
winds and storms because of negligence and
improper tie-down procedures. There is no doubt
that Mother Nature can turn the aircraft parking lot
into a junk yard in a matter of minutes. Whether you
are willing to admit it or not, if your aeroplane, or one
for which you were responsible, has been damaged in
such circumstances, the chances are that it was
improperly secured, or not tied down at all. In an
attempt to correct the situation this article is intended
to improve your knowledge on the correct way to tie
~own an aircraft.
Preventing damage
The best protection against storm damage is, of
course, to fly the aircraft o ut of the impe nding storm
area, provided you h ave sufficient warning time. The
next best protective measure is to secure the aircraft
in a storm-proof h angar or other suitable shelter. The
remaining alternative is to e nsure that the aircraft is
tied down securely. Do not d e pend on the aircraft's
weigh t to protect it from. wind damage; sudden and
severe gusts, particularly associated with willy-willies,
can destroy a parked a ircraft in seconds.
Advance planning
Always be prepared for the worst conceivable storm
conditions : pouring rain, gusty winds exceeding 30
knots and no hangar facilities ava ilable. With such
conditions in mind , aircraft own ers a nd operators
should plan in adva nce by learning their aircraft
manufacturer's recommendations for tying down ,
location and/or installation of tie-down rings for
attachment of ropes, special instructions for securing
nosewh eel type aircraft and ta ilwheel type aircraft,
ch arts and graphs denoting aircraft weigh ts a nd
relative wind velocities that wo uld make va ried
tie-down procedures necessary for p e nding weath er
e mergencies, correct fitment or control gust locks and
covers, a nd the correct a ngles for ropes and chains
relative to the aircraft. T his information is give n
briefl y in the Pilots Operating Handbook or Aircraft
6 I Aviation Safety Digest 110
Owners Manual, and in greater detail in the
Manufacturer's Service Manual.
If an intended llight includes a landing away fro m
base, and the aircraft will be left unattended fo r even
a sho rt time, a tie-down kit should be take n. This kit
should include adequate stakes, ropes, fittings, a large
hammer, control locks, ch ocks and covers for all
external openings.
Tie-down considerations
Ideally, an aircraft should be parked in an area
eq uipped with three poi nt tic-down s, and should be
tied down at the encl of each flight to preclude
damage from sudden weather changes . The direction
in which the aircraft is tied down will ultimately be
d etermined by the location of the parking area a nd
mooring points; however , whe never possible , the
aircraft should be parked nose-into-wind regardless of
whether it is nosewheel or tailwheel equipped.
Tail into wi nd is not a d esirable situation for any
aircraft as they are not stressed to take stron g winds
from the rear. The reasons offered for tail into wind
tie-down a rise from stories or aeroplanes ' (l ying' on
the tie-down ropes; howeve r, if' the aircraft is
properly secured it cannot 'fly' on th e ropes. T he use
of te mporary spoile rs on the wings, as discussed late r,
will reduce any tendency to fl y a nd also reduce the
loads on the tie-clown syste m.
Tie-down facilities
Tie-down anchors for single-engine aircraft should
provide a minimu m holding strength of
approximatel y 1350 kg (3000 lb) each ; for
multi-engine aircraft this should be in creased to
1800 kg (4000 lb). T h e type of anchor in use varies,
depending upon the type o r parki ng area surface.
Owners a nd operators who wis h to obtain more
information o n the ty pe of tie-down anc hors available
sh ould contact the Airports Engineering Sectio n at
their regional Department of Tra nsport office.
Woode n stakes dri ve n in to the ground a re not
de pe ndable a nd will inva1-iably pull out whe n th e
ground becomes soaked from th e heavy rain which
accompanies storms. Metal 'star' pickets ar e much
better becau se they can be driven deeper a nd will
hold firmer as they do not break up the soil. T h ey
should be driven in with a heavy h a mmer so that the
a ngle between the picket and the Lie-down rope is
about 90 degrees. 'Screw' pickets, a lthough not
common , are p robably the most secure of all and do
not need a sledge ham mer to secure the m in the
gro und.
T ie-down ropes sh ould be capable of resisting a
pull of a pproximately 1350 kg (3000 lb). Ropes
s uitable for use fa ll into two classes: manila (or sisal)
ropes and synthetic fibre ropes. These two groups
h ave entirely d iffere n t properties and should'be used
accordingly.
As manila ropes a re a vegetable fib re they are
susceptible to rotting and attack by fungus , and will
perish when affected by oil and grease. Their
strength deteriorates with age a nd the y sh ould be
inspected regularly. The main objection to manila
ropes is that they shrink when wet. The reason is
simply that the individ ual fibres sweH out and shorten
wh en the y absorb m oisture. When th e r ope dries out,
the fibres r e turn to their nor mal size. This
characteristic ma kes it difficult to und o knots after
the rope has become wet.
Synthetic fib re ropes arc not affected by oil or
moisture and a re reasonably stable in r egard to their
le ngth, although the y ma y stretch sligh tl y when hot.
Even so, they are preferable to manila ropes. T he
proble m with synthetic ropes is the te ndency for
knots to loosen a nd slip. Extra care is required and
knots tha t do not slip should be used.
Remember tha t no matter how strong the tie-down
rope, it is only as good as the kn ot being used. Make a
study of the types and application s of simple knots
a nd practise tying th em in the comfort of your h ome;
d o not wait until th e storm hits.
Securing the aircraft
Tie only at the p rop e r tie-down rings. Never tie to a
strut as the rope may slip a nd resu lt in bend in g of the
stru t.
Synthetic ropes are tied with out slack but also
withou t strain o n the aircraft. If usin g dry manila
rop e allow about 25mm (one inch ) slack to allow
shortening of the rope if it absorbs rain or dew. Wet
manila ropes may be treated as synthetic rope but
r emember that the knot may slip after the rope has
d ried .
T oo much slack will allow the aircraft to jerk
against the ropes , possibly looseni n g th e tie-down and
resulting in damage to the aircraft stru cture . T oo
much strain can place inver ted flight loads on the
aircraft, greater than it is design ed to take.
Wing ropes sh ould be tied so that they splay
forward and ou tward about 45 degrees to the ground
and th e nose/ ta il rop es sh o uld be in th e fore and aft
line of the ae roplane. The n ose and tail can have two
ropes each , both splayed outward fro m the aircraft
centre line. If the ropes a re knotted cor rectly, with
th e correct tension , the a ircraft is secure. At
aerod romes wh e re p arallel tie-down cables are
installed, the ropes are tied vertically to the cables,
with out slack.
All flight controls sh ould be secured to prevent
them ba n ging against th e stop s. Some aircraft are
equipped with in tegral gu st locks operable from the
cockp it. O thers require the use of externally fitted ,
padded control chocks. Some ma nufacturers
recommend securin g th e con trol column by u se or the
Aviation Safety Digest 110 I 7
�pilot's seat belt, while others provide control locks
fitted inside the cockpit.
When using external chocks, covers and plugs,
ensure that red streamers a re fitted to alert future
users of the aircraft. Ailerons and r udders should be
secured in their neutral position, as sh ould the
elevator on nosewheel aircraft. Flap s should always be
'up'. Tailwheel aircraft sh ould have their elevators
secured in the full 'up' position. I f it is absolutely
unavoidable tha t a tailwh eel aircraft has to be tied
down tail in to wind, the elevator should be in the full
'd own ' p osition.
Chocks sh ould be placed fore and aft of each wheel
a nd secured b y ropes or by nailing cleats from one
chock to the other. Housebricks and pieces of 'fo ur by
two' are poor excuses for chocks. Man y light aircraft
a re equipped with collap sible chocks made from ligh t
weight m e tal. As these ch ocks may be dislodged in a
strong wind or by the slipstream fro m other aircraft,
they should be secured by ropes on either side o f each
wheel.
Spoilers can be made from lon g sandbags a bout
50- 75 mm in dia meter (Grandma's door draft
excluders are ideal). They sh ould be placed at the 25
per cent ch ord line along the full sp an a n d secured
against m ovem ent. An alternative sp oiler can be
manufactured from a length of 50 x 50 m m tim ber
with a strip of foam rubber glued along one sid e to
p rotect the wing su rface. T he spoile r is placed on the
top of th e win g a n d secured by ropes or rubber
bungees. Pieces of cloth o r carpet sh ould be u sed to
p rotect leading a nd trailing ed ges against chafi ng by
the ties.
When secu r ing an aircraft, it is good p ractice to
faste n all d oors a n d windows properly, to minimise
d amage inside the aeroplane. Both exh aus t a nd
intake op enings for reciprocating and turbine
en gines sh ould be covered to preven t entr y of foreign
ma tter. Picot-sta tic vents a nd tubes should also be
covered to preven t damage.
Always secure th e aircraft by ensuring doors and
windows are locked ; leave the keys with some
responsible person.
Becom e familiar with local weather p atterns and
monitor weather r epor ts for high wind warnings,
thunderstorms or oth er poten tial h aza rds. Learn the
correct tie-down p roced ur es for your aircraft and
remember that aircra ft parked ou tside, in the op en,
should always be tied d own
'
,,
oxes', more correctly known as the Flight Data and Cockpit Vojce
.
..
In order to <;>bta(n a p ositive illus tratio n for th e points made in this article, staff of the Digest went
to Moorabbin A1rport to p ho tograph a properly secur ed aircraft. They were no t able to locate such
a n example, b ut were able to borrow wh eel ch ocks and a p itot c o ver to add to the aircraft
illustra ted above which was well tied down. Although this airc raft p r ovided the most suitable
subject, th e elevator tr im tab had not been se t in th e ne utral p osition. To satisfy the
man u_facturer 's recommendations it should also ha ve had the cowl flaps closed, a s urface con trol
lock installed o ve r the fin and r udder, and a tie-do wn rope securing th e nose g ea r torque link. It
was also note d that wh eel spats preclude th e use of wh eel c hocks of an effective size. •
8 I Aviation Safety Digest 110
Whe n an airlin e a ircraft is involved in an acciden t, the
ne ws med ia o ften ref er to a search being cond ucted to
recover the fligh t recorder 'black boxes'. T o man y of
th e ir read ers this term h as so me m ystical conn otatio n
bu t it is only a name given to ma ny items of
equipme n t fitted to aircraft, par ticula rly th ose of
comp licated m ech a nical or electronic d esign which
require specialist understanding.
Radio a nd electronic equipme n t racks in moder n
aircraft are filled with black boxes most of which, in
fact, are painted black. Fligh t recorders a re also in
boxes, of a simila r size to man y oth er items of aircraft
equipmen t, but th ey are pa in ted red o r ora nge, n ot
black. T his is to ma ke th em more conspicu ous
am ongst th e wreckage of a majo r a ircraft accid en t.
T h e recorde r boxes are also of special construction to
protect the r ecorder from high impact for ces, intense
fi re or a cor rosive en vi ronment. I n additio n , some
recorders are fitted with underwater location devices
and reflective tap e to assist in their recover y.
T h at such precautions are necessar y in dicates the
impor tance o f fl igh t recorde rs in a n a ircraft accid en t
inves tigation . Modern a ircraft are becoming more
complex , and flying high er a nd faster than before.
T hey are a lso much safer, but o n those infrequ e nt
occasions wh en the re is an accident, th e d amage to
the aircraft can be so gr eat that nor mal means of
in vestigative examina tio n are made extremely
d ifficu lt.
Anoth er development that is ma king fligh t
recorde rs even more essential is th e incr easing use of
cockpit instru me nts with various forms of electrical
p resentation . In th e event of a n acciden t, a nd the
resu ltan t loss of electrical power , all evidence of
instrume nt read ings can be irretr ievably lost - un less
retained on a flight recorder.
The FOR and CVR as fitted to the Boeing 727 aircraft, shown in
their pro(ective containers with the covers removed. They are
located in the rear fuselage of the aircraft as indicated in the
diagram above.
Aviation Safety Digest 110 I 9
�Flight recorders
There are actually two separate and distinctly
different recorders which can be fitted to an aircraft.
These are the flight data recorder (FDR) and the
cockpit voice recorder (CVR). The FDR is d esigned to
record information concerning the aircraft's flight
path. The CVR, perhaps better described as the
cockpit 'audio' recorder, provides a record of all
sounds in the cockpit area. This, of course, includes
flight crew statements, both on intercom and over the
radio but, of equal importance, also encompasses
such sounds as warning alarms, equipment and
engine operating noises, and even the background
airflow.
Together, the two recorde rs provide a wealth of
information that might not be available from a ny
other source. This data not only assists accide nt
investigators to establish what happened but, more
importantly, why it happened.
In Australia, it is a requirement that both types of
flight recorder be fitted to all aircraft over 5700 kg
maximum take-off weight which are turbine powered
or were first certified after 1 July 1965. This covers
most regular public transport aircraft, the
sophisticated executive jets and even the larger
turbine-powered helicopters.
Flight data recorders
There are several types of FDR available but only two
are common in Australia. The earlier models, which
are fitted to the majority of aircraft, record altitude,
airspeed, magnetic heading and vertical acceleration
against a time base. Operation of a microphone
transmission switch is also generally recorded, to
pe rmit accurate synchronisation between the FDR,
the CVR and any ground-based communication
recording facilities.
The information is engraved on a 12.5 cm wide roll
of stainless steel foil as it moves from a supply spool,
across a recording h ead, to a take-up spool. This
operation is similar to the movement of a film in a
camera, except that instead of a picture the result is a
senes of grooves cut into the foil. The foil runs for
200 hours of aircraft operation and then can be
reversed to engrave on the other side. The
photograph of a typical FDR tape indicates why this
type of equipme nt is generally referred to as a 'scratch'
recorder.
In the event of an accident the recorder foil is
placed o n a special readout machine a nd held flat
under a sheet of glass. The position of each scratch is
measured using an electrically positioned microscope
and the information fed into either an electric
typewriter or a digital computer. After correction for
variables, such as calibration figures, the data is
presented in diagrammatic form, portraying the
aircraft flight path prior to the accident. Much of this
work, such as positioning the microscope and tl1e
preparation of diagrams, must be done manually and
h ence readout of this type of recorder is a slow,
laborious task.
The second type of FDR is fitted to the later
generation of aircraft, for example Boeing 74 7s. T he
information is recorded on a magnetic tape, similar to
that used on hi-f'i reel-to-reel recorders, only in a
continuous loop of some 25 hours duration. These
newer recorders, known as digital flight data
recorders (DFDR), represent a significant advance in
10 I Aviation Safety Digest 11 O
terms of the amount of information available to
accident investigators. Australian aircraft with this
equipment are required to record a minimum of 20
parameters. These include the live previously
mentioned for scratch recorders, plus certain engine
parameters, aircraft configuration, control angles,
pitch and roll attitude, lon gitudinal acceleration , etc.
Each of these parameters is recorded at least once
every four seconds, but some in formation which can
change very rapidly, such as vertical acceleration, is
recorded as frequ ently as eight times per second.
DFDR equipment is capable or recording much
more than the required 20 pa rameters. Hence, many
operators voluntarily wire other aircraft components
and systems into the D FDR.
Readout of a DFDR tape is relatively simple and
quick, as it is largely a n a utomated process. If the
equipment is recovered intact it can be connected to
the readout station and its associated computer. If, on
the other· hand, the recorder is damaged, the
protected magnetic tape can be removed a nd played
back on reel-to-reel equipment. It is then only
necessary to program the computer to be aware of
those particular parameters recorded by the
individual aircraft operator, and the•readout can
proceed. Within a few h ours the accident
investigation team can be provided with a p rintout of
tabulated data. In many cases this results in early
elimination of those aircraft systems that were
functioning n ormally a nd e na bles the team's efforts
to be concentrated on the systems which show
abnormal indications. Later in the investigation it is
common to convert the tabulated data to graph ical
form for easier understanding.
The stainless steel tape from a 'scratch' recorder showing the series of grooves cut in the foil.
Cockpit voice recorders
The CVR is a four channel tape recorder, generally
using a continuous 30 minute loop of magnetic tape.
Normally, three of these channels are connected
directly into the captain's, first officer's and flight
engineer's communication panels, whilst th e fourth
channel is connected to an open microphone on the
centre or overhead instrument panel. Although the
playback equipment appears different from domestic
tape decks it operates in much the same way.
However, to gain maximum be nefit from audio
records it is necessary to have additional equipme nt
so that the CVR output can be filtered and/or
modulated to improve upon the original recording.
Other facilities, such as variable speed , repetitive
replay and spectrum analysis equipment, arc also
used to clarify distorted sounds and a nalyse the
s.ourccs of various n oises.
Use of data recorders
The development of detailed and accurate fligh t
recorders, particularly the DFDR, has greatly
simplified the accident investigatio n team's job of
reconstructing and analysing the events leading up to
the accident. One way in which this is done involves
the use of aircraft simulators. A simulator computer,
of the appropriate aircraft type, ca n be programmed
with the information obtained from a flight recorder
system to play back the accident flight. Not only does
this help establish what happened in the accident, but
also permits experim ents to be carried out to find the
best way to prevent another accide nt, should the same
circumstances occur again.
The FOR readout machine showing the recorder foil in place under the glass sheet.
Aviation Safety Digest 11 o I 11
�....
. ~·
-
..
.,
vJ!t~,.
,
..
Audio equipment used to read out CVR and Airways Operations tape recordings.
If a n accident happened at night, or over
mountains, a desert, a swamp o r lhe sea, the flighl
recorde rs m~ghl be the only means of eslablishing
wh a t happened. At the very least, the recorders save
an investigation tea m many da ys, or weeks, of d ela y as
they examine th e wreckage in an a ttempt to establish
the sequence of events. As a guide lo th e time and
effort involved in wreckage examination , a recent
ligh t aircraft accide nt in Au stralia required four
weeks for a lhree man investiga tion learn lo complele
the wreckage examination, establish a seque nce of
e ve nts, and isolate lhe probable cause of the accidenl.
Such an exercise with an aircra ft of the size and
corn plexity of a wide-bodied j el would be vastly more
difficull.
Flight recorde rs have solved many 'm ysle ry'
accide nts. On the other hand , there have been man y
accide nts involving aircraft not equipped with flight
recorders in which , despite eve ry possible effort, the
cause still remains unknown. In one overseas accident
an aircra l"l crash ed into th e sea and ve ry little of the
wreckage was recove red . Howeve r, the CVR was
found and this record alone was sufficient to establish
that the aircraft e ngines had not failed - as was
generall y ex p ected - but rathe r the accidem resulled
from a flighl control malfunction.
The flight recorders are, of course, particularly
valuable when the evidence is nebulous or transitory.
Possibly the besl example of this.is the great increase
in awareness of wind shear proble ms in recent years.
Prior to the develo pmenl of fl ighl recorders, the part
12 I Aviation Safety Digest 110
p layed by the wind in many aircra ft accide nts was
probably u ndereslimated. Tha nks to flight recorders
the sudden effects upon an ai rcraft flight path
resulting from wind shear can be establish ed. Also, in
the U nited States, the information obtained from
flighl recorde rs is being progra mmed into simulator
computers to pe rmit a n eva lua tion of pilot a nd
aircraft response to wind sh ear on approach.
Research and d e ve lopment of bolh equ ipmenl a nd
techniques, firstly to delect a nd then to counte r
problems su ch as wi nd sh ear, is slill in progress.
Australian facilities
The Air Safety Investigation Branch of the
Depanment of Transport has FDR and CVR
laboratories which a re equipped lo read out a ll types
of recorders fi tted to Austr alian-registered aircraft
and many of the recorders fitted to foreign-registe red
aircra ft. Accide nt prevention is an international
endeavou r and , in support of the International Civil
Aviation Organisation recomme ndations, Australia
provides a readout facility for a number of our South
East Asian neighbo urs.
Flight recorde rs will play an increasingly impo rtant
role in air safety as improved methods are d eveloped
for the ana lysis and interpretation or the recorded
information. In turn , this will provide the basis for
more effecti ve accide nt prevention and safety
education, thus a iding the whole aviation community
in its endeavours to improve safe ty in the air. •
•
In brief
A variation on Murphy's Law:
If there is a p ossibility of several thin gs going wrong, lhe one that will go wrong is the one that will do the most
d a mage!
Because o f" a flat aircraf"t bauery, the owne r of a
Cessna 206 d ecided to use a spare battery and
jumper leads to start the aircraft's engine, and then
run the eng ine to recharge the installed bauery. He
positioned the spa re battery 0 11 the ground j u st
fo r ward o f the le ft mainwheel, connected it to the
a ircraf"t batte r y, but then decided lo refuel the
a ircraft before he attempted to start the engine.
T he jumper lead s were disconnected f"rom the
a ircra ft and we re left lying on the ground, still
connected lo the spare baltery.
T he owner brought. some 200 litre drums of
Avgas to the ai rcra l"t and commenced refue lling the
left tank. The refuelling equipment consisted of a
do uble actio n hand p ump and a plastic hose. The
hose had no nozzle, and there were no metal
fittin gs o n the e nd of the hose. It was not bonded
and no earthi ng straps were used. A fter placing the
encl or the plaslic hose some 15 centimetres into the
ta nk, the owner climbed clown from the wing and
began to pump the l"uel. The vibration of the pu mp
caused the hose to come out of" th e fuel tank and
fall to the ground. I t fell on to eithe r the battery o r
the jumper lead te r minals. A static discharge from
the plastic hose or a short belween the lerm inals
provided a spark and ign ited the spill Avgas.
A large fire immediately broke out around the
nosewheel or the airc raft. The owner went to obta in
li re fighting equipment and assistance, bu t on his
1·eturn only lwo or three minutes later the fire was
too intense to be approached. As the fire
progressed an unopened 200 litre drum of fuel
benealh the right wing of the aircraft explod ed.
The aircraft was d estroyed.
Aviation Safety Dig est 110 I 13
�In the past there have been many examples of problems caused by undesirable haste in dealing with
inflight emergencies. On other occasions pilots have dealt successfully with the inflight emergency, but
have then caused further problems by not complying with standard procedures in their efforts to return
to earth as soon as possible.
This article relates the planning, co-operation and effective use of all available resources which
prevented landing gear damage on an aircraft from causing a major accident. It is reprinted from the
February 1980 issue of The MAC Flyer.
(Photographs courtesy of the Christchurch Star)
..
Although our goal is usually a smooth landing, this crew found themselves faced with the problem of ...
How 'to plan a crash landing
"Not an exp erience I wo uld recommend." T h at's how
Captain Robert E. Colley described to reporters his
crew's dramatic "planned" crash landing of a C- 14 1
Sta rlifter at Christchurch, New Zealand. Departin g
Chr istchurch on 29 October 1979 for a round trip to
Williams Field, McMurdo Station , Antarctica, the
349th Military Airlift Wing (Associate) crew's flight to
th e frozen continen t was routine until their landing
o n grid runway 26. During th e roll out th ey
experienced an extra rough r ide on the s now-covered
ice runway. Post flight inspection of the 14 1 revealed
a sha tte red taxi light a nd a broken brake line. W ith no
e n route maintena nce available, th e crew capped th e
lin e and refilled the number three h ydra ulic system.
L ess than two hours later, 4 1 000 kilograms of fuel
and 12 passengers were aboard fo r the re turn fligh t
to New Zealand. With Captain Colley in the left scat
a nd Major John W'. H artzell fl ying as copilot, the
Starli!"ter started its take-off at 06 15 hours GMT. .Just
as Captain Colley barked , "Gear up ," the copilot
noticed an unsafe ind ication for the right main gear,
and did not raise the handle. At nearly th e same time
McMurdo lee Tower called, "MAC 249, you lost you r
starboard wheels. T h ey're hanging ."
Captain Colley le velled the Starlifter at 3000 fee t
a nd kept the sp eed below 235 knots. He then
transferred aircraft control to Major Hartzell and
asked th e scanner , MSgt Stephen E. Reynolds, to
check the gear. A ch eck by lee Towe r confirmed that
the righ t ma in gear was positioned lower tha n
normal, and th e controller specula ted that it was
"h anging by h ydraulic lines". From inside the
14 I Aviation Safety Digest 110
Starlifter , Se rgea nt Reynold s could not see inside the
gear well because or ice on the inspec6on window.
Meamvhile th e navigators, Lt Col FrankJ.Jackson
and Captain Lance W. Bachran, busily calculated
th eir ch ances of getting to New Zealand. Without fu el
consumption cha rts ava ilable for gear d own cru ise, it
was im possible lo determine fo r certain if MAC 249
could make landfall in South ern New Zealand. One
option which seemed the most reasonable however,
was that they co uld cruise north ward for abo ut two
hours , see h ow th ings we re goin g, a n d still be able to
retu rn to McMurdo if need be . Based on this, and the
generally inhospitable conditions in An tarctica,
Captain Colley decided to contin ue on co urse for
their original desti nation . He directed Maj o r Ha rtzell
to start a climb at 235 knots, th e gea r limiting speed .
At FL 200 , 235 kn ots equalled .55 Mach, so the
Starlifter was cru ising as fast as it could withi n
technical order limits. With the copilot controlling the
C- 141, Captai n Colley worked the HF radio to get
more in formation on how to best handle the
malfu nction . Beca use ol"their remote location , he was
unable to set up a normal Confere nce Skyhook with
the 22nd Air Force . Fortunately, another Sta rlif"te r,
MAC 59403, had depa rted McMurdo two hours
earlier and that crew was in contact with the MAC
Operatin g Locatio n al C hristch urch. Aboa rd MAC
403, Major Peter .J. Ruppert, 60 MAW Standard s a nd
Evaluation , offered to relay messages for 249.
The crew's most pressing problem was ensurin g
tha t th e fuel in their C- 141 's tanks wou ld provide
eno ugh endura nce for a la ndfall and a safe
•
to uchdown in New Zeala nd . Extra drag from the
extended wheels was increasing fuel consumption
significantly above the normal cruise fuel flow. After
conferring with Major Ruppert and the exper ts
assembled a t Christchurch, Captain Colley decided to
retract th e functioning la nding gea r.
Workin g the engineer's panel, MSgt Alexander
Sch neider pre pared to dep ressurise the aircraft so
that th e main gear could be pinned and electrically
disconnected from the gear system. In the cargo
compartment, TSgt William R. Friedrich , loadmaste r,
discussed the e mer ge ncy with the passengers and
helped the m d on oxygen masks. With the crew and
p assengers on oxygen, the cabin was d eprcssurised,
the scanner pinned the gear and then cabin pressu re
was restored. Finally, the left a nd nose landing gear
we re retracted .
Even with this decrease in d rag, the fuel flow
remained high , a nd after consultation with the
experts in MAC 403 and at Christchurch , it became
obvious tha t 249 wou ld have to climb to make it to
New Zeala n d. Because of the decreasi •~ g air de n sity,
this option requ ired increasing the Mach n u mber and
thereby exceed in g n ormal oper ating limits.
Experimenting with the Starlifter, Captain Colley
found tha t the cr ippled aircraft began to buffet at
sp eeds a bove .63 Mach. T herefore, the copilot kept
the speed below .62 d uring the climb to FL 300 . Tb is
action , couple d with a fa vourable wind shift, assu red
them o r at least reaching one of the two airfields in
Southern New Zealand - Dunedin or I nvercargill.
As the plane consu med fuel, they were able to climb
high er and eventually reach FL 350. Beller engine
efficiency at the higher altitudes assured landing
somewhe re in New Zealand, and recovery at
Christchurch became a p ossibility. The origin al flight
had called fo r five h ours flying to their d estination,
but because of their decreased speed, the mission
would stretch to over seven hours.
While the right-seater h an dled th e aircraft, the
pilot-in-comman d , the crew , a nd experts on the
ground began plan ning fo r th e upcomi ng la nding. As
time p assed, they reviewed several checklists and
Dash One (Flight manual) discu ssion s th at seemed
appropriate to their situ ation. Ahead at Christchu rch,
MAC people were in contact with the 22nd Air Force
Standards and Evaluation and Lockheed , the
Starlifter's manufacturer, wh o provided expert
ad vice and d etailed technical information. T ogether,
th e ground-bou nd advisors compile d a list of things
for MAC 249's crew lo conside r before landing.
Captain Colley's ini6al plan was to land with the
nose gear down and pinned , and the left main gear
up, because he believed the right gear truck would
separate from the plane upon tou chdown. Generally,
this seemed to be a way to keep the Sta rlifle r on the
runway a nd give the cre w and passengers th e best
ch ance for survival. Next he made sure every crew
member understood the plan of action for th e
u pcoming nigh t app roach and emerge ncy landing. I n
the p ilot's words, "We made plans but still tried to be
flexible a nd open to suggestions .. . (th e n) we
1·ehearsed it."
Abou t 500 miles out, the fuel status gave the crew
enough confide nce to try for a landing at
Ch r istchu rch . "(At this point) we h ad no doubt that
Aviation Safety Digest 11 O I 15
�we could make la ndfall in New Zealand," recalled
Captain Colley, "but when we turned for
C hristchurch . .. we were committed."
"The radios hadn't been quie t for five minutes," the
Captain remembered, and about 150 miles out he
finished his consultations on HF and took control of
the aircraft for descent and landing . As the Starlif"ter
descended below 10 OOO feet, the e ngineer
depressurised the aircraft. For the first time, Sergeant
Reynolds was able to remove the gear pod access
panel and take a good look at the da maged bogey. He
saw the gear truck was still attached to the 14 1 by the
scissors assembly, and the crew estimated that the
gear might stay with the aeropiane for part of the
la nding rol l.
Now awar e of the right gear's true condition, the
crew and the experts on the ground re-evaluated
the ir pla ns. They decided that landing with all the
wheels down mig ht be the best course of action. Also,
the crew would pin the nose gear down so that the left
main could be retracted if necessary to keep
directional control after touchdown.
Air Traffic Control vectored the Starlifter for an
ILS approach to Runway 20 at C hristchurch. Gear
extension was delayed until they were o n base leg to
further conser ve fuel. As the 14 1 let down throu gh
the da rk mist above the Waimakariri River on the ILS
glideslop e, Captain Colley spotted the approach lights
a t two and a h alf miles out. The da ngling right gear
touched the runway first, a nd a few seconds later the
Captain set the Starlifter's weight on the le ft main and
nose gears. Captain Colley held left aileron in to keep
weight off the damaged right gear. As the aircraft
slowed , the right main gear truck, which was laying
on its side, became trapped under the gear pod and
helped for a while to su pport the aircraft's weight.
The copilot shut d~wn the outboa rd e ngines as
planned, and when the Starlifter's speed reached
about 50 knots, the right ma in gear truck finally
separated. The big airlifte r smoothly settled on to the
number four engine and the rig ht wing tip. Although
it veered to the right before grinding to a halt with
4000 feet of runway remaining, MAC 249 stayed on
the pavement. In the 50 emergency vehicles that had
responded, crash crews·watched a momentary rooster
tail of sparks fly clear above the Starlifter's T-tail as
the right outboard engine and wing tip skidded along
the ground.
After the C-141 stopp ed , Sergeant Reynolds
opened the crew entrance d oor and assisted the
passengers and other crew me mbers in departing the
aircraft. Captain Colley a nd Major H artzell were the
last to leave the flight d eck a nd ch ecked the cargo
compartment for possible stragglers before they
abandoned the crippled C-141. Fire department
vehicles were at the scen e in seconds and started
pouring water and foam on the number four engine,
right wing, and along the side of the fuselage.
Fortunately, there was no fire.
'
· Captain Colley a nd his crew had worked their way
through an extremely serious emergency situa tion.
They were successful for man y reasons : their own
ex pertise, the aircra ft commander's leadership, the
availability of experts on the grou nd to h elp , and the
advice and co-operation of the crew of MAC 403.
Some might conte nd a bit o f lu ck was also a factor.
But isn't luck, after a ll ,just the crossroads where
opportunity and preparatio n meet? •
Unnecessary distraction wheels up landing
T he chief pilot of a country based charte r company
had developed a standard procedure of !lying
straight in approaches in his operations whe rever
possible. Subject to fami lia rity with the destination,
prevailing conditions and traffic, he would use the
strip or rumvay aligned closest to his inbound
track. He consid ered himself ver y familiar with the
aircra ft and used this procedure irres pecti ve o r
wi nd direction, unless a d own wind was too strong
fo r a short strip.T he sole reason for th ese
operatio ns was to save time. ln disr egard ing the
regulations relating to ope rations f'rom aerodro mes,
the p ilot chose to ignore proce dures which have
been develo ped for the safe a nd e fficien t use of'
f'acilities by aircraft operators.
O n th is occasion the pilot was returning to base in
a Cessna 2 10 from a ch arter flight to a town a bout
180 kilometres east of the base. T he cast-west strip
at the base had been sh ortened by 720 metres to
16 I Aviation Safety Digest 110
1066 metres a few years before. It was the pilot's
habit to touch down on the disused portion of the
strip whe n la nding in to the west, especially when
operating with a downwind or crossw ind, to allow a
longer landing run a nd thus reduce brake wear.
The Flight Service Uni t passed the wind velocity as
'zero one zero degrees, one zero knots', but the
pilot read the direction as one zero zero degrees.
He intended to land straight in on the 27 strip,
even though he expected a 10 knot downw ind .
At top of descent from 6500 feet, the pilot was
given traffic o n a Cessna 182 inbound from the
no rth west a nd estimating the circ uit a rea abo ut two
minutes before him. He now decided to d elay his
final cho ice of landing direction until in the circuit
with the other aircraft in sight. In the circuit a rea
the Cessna 182 pilot re ported overfl ying for the 09
strip, but shortly after advised changing to runway
04.
View of the aerodrome facing west, showing the approximate flight paths of the two aircraft during the circuit entry and approach to land.
Meanw hile the Cessna 2 10 had e nte red the circuit
an d was !lying an abbreviated patte rn for the 27
strip. H e had in fact not flo wn over the fi eld , but
had turned crosswind prio r to reac hing the 27
th res ho ld . Th is meant that he turned away from
the othe r traffic, and although he requeste d the
other's position twice, a nd was looking for the
a ircraf"t throug hout the circuit, he still had not
sighted it by the time he touched dow n . He fa ile d
to hear a taxying call from the ai rcraft some two
m inutes prior lo his landing.
T he e nd result o f this continuo us distraction was
that the Cessna 210 landed wi th wheels up o n the
d isused section o f' the 27 strip, over 380 metres
sho r t of the threshold.
The pilot did no t use a printed check lisr, but had
committed down wind and fin al checks to memo r y.
T he first ite m o f the downwind check was to extend
the la ndin g gear a nd make the first selection o r
flap. T he last ite m was to check the la nding gear
extended gree n light a nd visually confirm the
extension o r the left main gear . His prelanding
check on fi n al would also include the green light.
On this occasion the pilo t considered that he had
fu lly comple ted all the checks. In fact he had gone
th ro ugh the lists mentall y without physically doing
or checkin g some o f the items. H e realised on final
that he had not extended any flap at the normal
downwind position , but did not realise that he had
a lso omitted to extend the la ndin g gear.
Thus the pilot's complacency and over-familiarity
with the a ircraft and his compan y's operating
procedures combin ed with his unorthodox practices
created un necessa r y d ifficulties for him which led to
the omissio n. A furthe r exa mple of the pilot's
attitude lo his responsibilities is that at the time or
the accident his Commercia l Pilot Licence had
lapsed: the expiry d ate was over six weeks earlie r.
T his accide nt demo n strates the necessity of
conform in g to established procedures for the good
of all members of the aviation industry. In an effort
to save a few m inutes, this operatio n cost a lot more
tha n it could h ave gained. We can retrieve so me
value from the accident if we are prepared to learn
from another's mistake. Bad habits do not just
appear. They are a llowed to d evelop•
Aviation Safety Digest 110 I 17
�-- i j
The Engine Doctor and density
altitude
During the investigation of a n aircraft accident which
occurred in Central Australia in midsummer, the
pilot revealed a distinct lack of knowledge on the
subject of de nsity altitude. At the time of th e accident,
1700 hours local, the temperature was 39 degrees
Celsius. With an aerodrome elevation of about 1700
feet AMSL, this resulted in a density altitude of nearly
5000 feet. T he pilot was unaware of the possible
effects of this on his airci"aft performance a nd once
again , as so often is heard, h e had been told that
'leaning the mixture is not d on e below 5000 feet'.
T o help you better understand the effects of
density altitude on aircraft performance we prese nt
the third article in the Engine Doctor series, adapted
from the U.S. Federal Aviation Administration
magazine, General Aviation News.
Aircraft Owner: Doctor, I've just had a shattering
experience in my aeropla ne.
Doctor: Not literally, I hope.
Owner: Worse! I've been humiliated , in a public
place. I d on't know wh at I'm going to d o. I may never
fl y again.
Doctor: I see. Well, that certainly seems to be a
problem. Is there a nything I can h elp you with?
Owner: T he re sure is. You can tell me what's
wrong with the engine in that aeropla ne of mine,
which you certified just last month as being okay. It let
me down when I needed it most. It had about as much
power as a sick kitten.
Doctor : Well, I remember it looke"c.i pr etty h ealthy
to me. When did th e problem develop?
Owner: My partner and I went to a density altitude
seminar at one of the outback aero clubs and the y
were going to have this ta ke-off contest on the next
day, lo see wh o could come closest to getting off in the
distance they p1·edicted . My partner introd uced me
around but then he got to saying that I was an ace
pilot when it came to fl ying by numbers, and I was
sure to win the take-off con test. H e even offered to
bet an yone in sight, and give them odds. T here
weren't an y takers but I gu ess they were just being
polite. You beginning to get the p icture?
Doctor: I believe it's coming imo focus. I will
assume that you d id not win. Wh ere did you rinish second ? Third ? A bit further back?
Owner: All the .way back. I was about fortieth in a
field of 40.
Doctor: That is discouraging . Wha t we re the ru les
of this competitio n ?
Owner: Well , they bad Runway 19 set up with
judges alongside the field and instruments so that
they could tell how much d istance from start it Look
you to clear a 50 foot obstacle. You we re penalised fo r
every extra metre yo u allo wed yourself and
disqualified if you clicln'Ld ear that imaginary barrier
in the distance you predicted . They had one category
for private pilots, a nd anothe r for commercial, etc. (){'
course I had to go for broke.
Doctor: Of course . May I assume tha t you made all
the necessa ry computations correctly?
Owner: You bet. At standard conditions m y
18 I Aviation Safety Digest 11 O
aircraft needs about 625 metres to get o ver a 50 foot
obstacle, according to the book. Temperature was
about 24 degrees Celsius at noon and the field
elevation was 2300 f ee t. On the chart that added up to
a 50 per cent increase in take-off distance , so I threw
in a little for good measure and added 300 metres to
the 625 - 925 was the number I pill down. Actually I
figu red I could clear the obstacle in about 800 ,
considering the way that powerplant was purring
whe n I left h ome. I would h ave, too, if the engin e
hadn't let me down. Would you believe it, I was still
strainin g to get airborne when we passed under the
obstacle point?
Doctor: Hmmm. Anyone else have that problem ?
Owner: Yeah, the re were several other pilots I
knew had a struggle, but n o one overshot the mark as
far as I did. According to the theodolite
measurement, it took me 1260 metres from starting
roll to get up to 50 feet above the runway. If those
judges hadn't been friends of m y partner I would
have been sure som ebod y was kidding . I was so
humiliated l almost fle w straight h ome after I got into
the air.
Doctor: A painful experie nce, I'm sure, but also a
learning experience.
Owner: W h at d id I learn ? Seem ed to me I just h ad
a weak engine - I could feel it was not running
smoothly durin g the ta ke-off.
Doctor: Did you have a ny trouble with the engine
once you became airborne?
Owner: No, n ot after I leaned it out.
Doctor: Aha! Did you try leaning slightly before or
during the take-off?
Owner: Well no , the airport ele vation was only
2300 feet.
Doctor: Ah, but what was the density a ltitude ?
Owner: How should I know?
Doctor: The re are formulas and pre pared tables
for compu ting d e nsity altitude. ICyou have a fl ight
compu ter you can work it ou t yourself. It is
importa nt. On the stre ngth or the figures you
mentioned, I would say that you we re a l about 4000
foot d ensity altitude. That means that for best
performance in yo ur aircraft it may have b een
necessary Lo lean yo u r engine sligh tly for take-o ff.
An ything less than best pe rformance wou ld extend
the take-off.
Owner: I can 't believe th at would make me go 300
merres past the mark. No way.
Doctor: Oh , l agree , that is onl y one oflhe factors.
Let's look for some oth ers. T e mperatu re, for
example, is critical. Where and when did you get your
te mperature rea d in g.
Owner: I took it off the OAT gauge, right ab out
noon.
Doctor: I see. And how soon after that did you
take-off? Righ t away?
Owner: Well, n o, not r igh t away. I be lieve there was
a little de lay, we had some proble m with the
communicatio ns. I think I got off a bout one o'clock,
local time.
Doctor: A full hour later!
Owne r: So wh at? T he temper ature would be
pea king a t n oon , would n't it?
Doctor: Not at th is time of the year, where you
were. Rem e mber , on daylight saving time the sun has
a nothe r h our to reach its zenith. On a clear day the
te mperature might peak aro u nd 1400 local or later. It
so ha ppens I a tte nded a recent density altitud e clinic
like this at a place where the temperature peaked out
at 35 degrees Celsius between five and six o'clock.
One cha p was nearly 700 metres beyond his mark
before h e got u p lo 50 feet. T he actual temperature
when yo u took off could easily have been 28 degrees
instead o l' 24. That would ma ke it . . . uh, 17 degrees
above standard . If yo u check your chart I think you
will fi nd tha t woul d give you about 50 metres more
needed ror yo ur take-off ru n .
Owner: H ow is that? Doesn't 15 from 28 equal 13?
D o cto r: Standard temperature varies according to·
al ti tud e. At 2000 feet AMSL it is not 15 but 11
degrees.
Owner: I d on 't th in k I will ever get that straight. I t
just d oesn't make sense Lo me that the higher the
tem perallffe, the higher the density.
Doctor: T h a t is n ot how it works. Density altitude,
first of a ll , is a theor etical concept - not a point in
space or in the s ky. I t happe ns to be \le r y useful. Let's
see if we can simpli fy . You know that at sea level, at
wh at we ca ll sta ndard te mpera tu re (15°C) an d
p ressure ( I 0 13 .2 millibars) a block of ai r will always
h a ve the same d ensity - the same number of
molecules of air per cubic foot. You a lso know tha t in
o ur atmosphere te m perature declines about two
d egrees Celsius fo r every I OOO feet you climb - mo re
if the air is d ry. So at 5000 feel the standard
tempe ra ture on this same clay wou ld be about rive
d egrees, and th e de nsity of the ai r considerably less
tha n a t sea level.
O wner: If the a ir temperature is down al higher
a ltitudes, would n't d ensity go u p ?
Doctor: No, beca use gravity is a lso a facto r here.
The h igh e r you go, the weake r the gravita tional pull,
the fewer molecules per cu bic foot; a bove-stand ard
temperatu res a lso thin out th e nu mber of molecules
per cubic foot or air. T h inn er, or less de n se air, makes
the aeroplane act as th ough it were higher than the
altimeter (or p ressure) altitude . So de nsity altitude is
the altitude en viron ment in terms of the actual
nu mber of molecu les pe1· volume or a ir, compared
with the normal or standard n umber of molecu les, in
a given volume at a given elevation. I n even simpler
terms, it is the equivalen t altitud e yo ur e ngine
breathes.
Owner: Isn't the rest or the aircraft affected?
Doctor: Of course, the entire aircr aft behaves in
accordance with th e d e nsity of the a ir - rathe r than
accord ing to the elevation. When de nsity al titude is
higher d1an pressure altitude, p rop eller th rust is
reduced (so is drag, on the oth er hand), and there is
less lift and less resista nce to the a ir. T rue airspeed is
much higher than ind icated airspeed, but you may
not be aware of this because nor mal indicated
ai rspeed readings are still applicable fo r virtuall y all
operations - stall speed, climb speed , appr oach , etc.
T he giveaway is the vertical speed ind icator, which
reads below normal in a climb.
O w ner: I s th at why you seem to climb so slowly in
the mountains in summer - it's not just your
imagination, and the closeness of the cliff faces?
Doc tor: Precisely. And with a higher true airspeed
you need more late ral room fo r manoeuvr ing,
especially in valleys, a nd at aerodromes with runways
of marginal length . Overshooting is always possible.
If you try to avoid th is by ap p roaching to land at a
subnormal indicated airspeed, you cou ld easily land
short.
? wne r: Sou nds like they've got you , coming or
gomg.
Doctor: Not really. You simply have to make
appropriate a llowances fo r th e environme nt your
Aviation Safety Digest 110 I 19
�ail-craft is experiencing, rather th an for the altitude
yo u read off your altimeter.
Owner: Can you ever get such a thing as negative
density altitude - say in win ter?
Doctor: Certain ly. And not just winter, but a t night
or whenever the temperature fa lls below sta ndard. It
is computed in terms of a theoretical point below sea
level. Normally it presents no problem to fl ying and
we are not even awa re of it, except perhaps in terms
of increased engine performance. There is a
p ossibility, with a controllable propeller, o f
overspeeding the engine, but it is sligh t. On the other
h and, I recall one occasion where I was attempting to
take off in a 172 in the dead of winter. T h e density
a ltitude was computed by the tower as just about 3000
feet below sea level. Do yo u know, I was simply unable
to get a rich enough mix ture into the carburettor to
get off the ground ? B u t that's rare.
Owner: You know I was way under max gross
weight, which is what most o r these performance
computations arc based on , so that sho uld h ave given
m e a big edge, sho u ldn't it?
Doctor : It helps, but unless you know ~xactly how
much d ifference it makes in yo ur aeroplane - it
varies a great deal from on e to another - you don't
wa nt to ban k too heavily on it. Let's look at some other
factors. I-low about the wind ?
Owner: Negligible - three to five knots.
Doctor: Straight down the runway?
Owner: No, we we re taking off on 19, and the wind
was from the west somewh e re - we didn't p ay an y
attention to it because it was so light.
Doctor: Just the same, in a critical condition , even a
very light wind off the beam could affect your
take-off and climb performance if you are used to a
head wind . H ow about the slope?
Owner: Slope? There wasn't any runway slope - at
least that I heard about.
Doctor: Did you ask an yone? Many aerodromes
have run ways with a small degree of slope which is
not mentioned in a n y of the o fficial publicatio ns
because no safety factor is in volved. But whe n you are
trying to be precise o n your take-o ff - or whe n the
surrou nding terrain actually does m ake the operation
critical - even a slight uphill sla nt to the runway will
extend your take-off. By and large, take-offs in hill
country or from mountain a irports are made
d ownhill by knowledgeable pilo ts, regardless of the
wind. You don't ever wa nt to try to outclimb the
te rrain on take-off.
Owner: Not in that crate of mine.
Doctor: Come, come, let's n o t blame the
eq uipment, unle~s we're sure o ur own h a nds arc
clean . It's a good aeroplane o r you wo uld n't own it.
Let's look a little further. What abou t the climbou t
p ro fi le?
Owner: Strictly by the numbers.
Doctor: Very good . Do you re me mber the airspeed
whe n you lifted on ?
Owner: Negative, but I took off j ust like always trimmed h er up and let her fl y h erself off. l never
horse it up.
Doctor: Well , that's fine , und er man y
circumstances. But if the problem is to get off and up
over a given terrain obstacle, in the shortest possible
d istance - which ofte n happens in mountain flying
- you want to h old the aircraft on the ground until
yo u reach th e best angle of climb speed, and then lift
20 I Aviation Safety Digest 110
o ff firmly and smoothl y, h olding that speed. Now
wha t about the climbout - what was your airspeed ?
Owner: Strictly by the book. Ten degrees of flaps
and 82 knots, for best rate of climb.
Doctor: Best rate? Oh, d ear. Oh , dear.
Owner: What's the matter ?
Doctor: I'm afraid that's wh ere you blew it. l
wonder how many unfortunate pilots have racked up
aircraft because they confused best rate of climb witl1
best climb angle. It seems that the tighter the bind the
poor chap gets in to, as concerns surrounding terrain,
the more likely he is to go to excess airspeed in an
effort to outclimb the landscape. There is some
fateful notion that safety lies in greater airspeed, but
actually every knot you add on over the best
a ngle of climb speed redu ced your chances o f getting
over the obstacle. I realise the terms may be less than
indicative , but somehow you must get it straight that
best rate o f climb me ans best ve rtical rise within a
given time' whereas best angle or climb (with a slower
airspeed) means best rate of climb with in a given
lateral distance. When it comes to clearing an obstacle,
distance is the all-im portant facto r , not time. It
doesn't matter if it takes you a n hour to get over a
ridge, as long as yo u dear it safely. If you get in a
hurry about it, you may ru n out of room in a hurry.
Owner: I guess you 're right. I got so impatient
finally I took the fla ps off.
Doctor: Another no-no. That cost you alrj tud e.
Your plane's best angle of clim b configuration calls
for 35 degrees of naps, and there is no way of getting
around it.
Owner: Okay, what else did I do wrong?
Doctor: N othing, I susp ect. All those things we
mentioned may seem of little consequence ta ken
piecemeal, but wh en you put them togethe r they
cou ld add up to qu ite a bundle - perhaps enough to
spell the difference between survival and d isaster in a
real life situa tion. I suggest you set up a p ractice
course at yo ur home aerodrome and see how close
you can come to flying the aircraft accordi ng to its
specified performance ability. I'm sure yo u would
soon see a vast improvement.
Owner: I'm n ot so sure. I'm a slow learner.
Doctor: Perh aps they shou ld have given you tl1c
same co nsolatio n p rize th C)' gave the cha p who
recently finish ed last in one of these contests. At the
Awards Banquet they prese nted him with a seedling
tree which he was to plant beyond the run way of his
ch oice. The idea being that in 50 years the tree would
grow to a h eig ht o f abo ut .10 f'eet, and by th at time ,
with regular practice, he wou ld be able to lly over it
safely. I t was quite fu nn y, 1-eally.
Owner: Goodbye, Doctor.
Doctor: Please don't go away a ngry. It was a ll in
l'un. As a ma tter of fact, I suspect that he - and you
- we re the real winners ol' these competitions.
Owner: H ow d o you figure that?
Doctor: Well, I don't thin k the objective was really
to d etermine the p ilot who cou ld handle al titude and
obstacle clearance problems best, do you ? Wasn 't the
point to learn something about one's fl ying
techniques in a way that sh ook yo u u p without
actually exposing you to a ny da nge r ? And who was
more sh aken than you ?
Owner: No one. Goodbye again .
Doctor: Keep sm iling. Next please •
The Beech Baron D55 had been hired by a football
club to convey five of their players from Perth to
Norseman for a game at Kambalda. The aircraft
departed from Jandakot at 0805 hours local time
with the pilot and two of the players on board. It
landed at Perth Airport and the other three
passengers boarded the aircraft for the flight to
Norseman. Shortly after arrival, at about 1000
hours, the passengers and the pilot were transported
by coach to Kambalda.
During the afternoon the pilot telephoned
Kalgoorlie Flight Service Unit to obtain the latest
meteorological forecasts for th e return flight to Perth .
He was advised that there was a probability of fog
developing at Perth, so he nominated a departure time
from Norseman of2100 hours, with Meekatharra as
a n a lternate.
Arra ngeme nts were made for additional fuel to be
added to the aircraft because o r the possible
diversion. On return to the Norseman aerodrome, at
a bout 2000 h ours, the pilot super vised the addition of
195 litres of fuel to the aircraft tan ks.
After preparing the aircraft, the pilot and
passengers boarde d and the engines were started. It
was a clear, da rk night with no moon and a slight,
southerly wind blowing. The aircraft proceeded to
tl1e northern end of the main strip . Radio
communications were established with Perth and the
pilot reported taxying. H e was advised that there was
no known traffic in the area. His acknowledgement
was th e last communication received from the
aircraft.
Bystanders indicated that each en gine was ru n up,
and the navigation and land ing lights were
illuminated. Take-off commenced towards the south
and the aircraft appear ed to become airborne in a
normal manner. At abou t 200 feet it commenced a
left turn, initially mainta ining height, but, as the angle
of bank increased, tl1e aircraft descend ed until it
struck the ground in a steep nose-down, left-wing
down attitude on a northerly heading. A fierce fire
broke out on impact and all occupants were killed.
Detailed examination of the wreckage during th e
subseque nt investigation revealed no d efects or
malfunctions which might have contributed to th e
accident. There was evidence which indicated that
both engines were producing substantial power at the
time of impact.
The investigatio n did, however , reveal that the
elevator and aileron control lock was at least partially
engaged. This lock consisted of a steel pin normally
inserted through an alloy lug on the instrument
panel, below th e control column shaft. I t was also
p ossible to lock the aileron and elevator controls
together by inserting the p in into the con trol column
without first passing it through tl1e lug. In th is case
the aileron controls would be locked and the elevator
control could be moved rearward from about the mid
position but could n ot be moved forward.
Because the lug was destroyed by the fire it was not
Aviation Safety Digest 110 I 21
�r
possible to d etermine if the pin h ad been inserted
through it; however, th e pin was in place in the
control column. Nevertheless, with th e p in inser ted in
either manner , th e pilot would have been de nied
a ileron and a t least partial elevator con trol, durin g
b oth ground and air operation o f the a ircra ft. T he
flight pa th of the a ircraft as d escribed by witnesses to
the accident was consiste nt with the con trols being
locked by eithe r of the two me thod s d escribed .
T h e restriction to control surface operation sho uld
have been obvio us if p reflight, vital actions had been
performed . T h e cau se of th e accide nt was therefo re
con sidered to be th at the pilo t did no t perform
ad equate p reflight p rocedures.
T h ere could be a number of reaso ns why the pilot,
wh o was apparently conscientious abou t his operation
of the aircra ft, could become airborne with the
con trol lock in place. T he ta rdiness of the last
passenger boarding the aircraft, concern about a
p ossible diver sion d ue to fog at the destina tion , or a
numbe r of o the r factors could have distracted him.
T h e actual reason or reasons for his failure to rem ove
the lock will never be kn own .
T he design of the control column lock was not
altogethe r conducive to safe op eratio n in tha t visual
ch ecks were inhibited by the lock being under the
co ntrol column . O n la te r m odel aircr aft the pin is
inserted th rou gh a lug above th e column wi th the
ele vator control close to its full fo r ward position . T he
control column lock pin in this a ircraft was joined by
wire to th e r udde r lock a nd the mixtu re control lock,
a nd it would ap pear tha t those locks we re not in
position d uri ng the final op era tion of th e aircra ft.
22 I Aviation Safety Digest 110
Above. Control column lock correctly fitted to the same type of Beech
Baron as the one featured in the accident report. Note that the pin is
inserted through the aluminium Jug, thus preventing movement of
both the aileron and elevator controls. Also note the separate hood
over the mixture control knobs.
Opposite. Control column lock notinserted in the lug. This position
Jocks the aileron control but allows movement of the elevator from
about neutral to the full up position.
Title illustration: The type of control lock ficted to later model Beech
Barons. Note that the aluminium lug is repositioned above the control
column and the one Jock operates on the aileron, elevator and engine
controls.
Whe ther yo u call them p re-take-off checks,
before-ta ke-off vital actions or som e o the r name, th e
checks recommended by the ma nufacture r are the
minimu m necessa r y to ensure that th e aircraft will fl y
safely, p rovided nothing un toward occurs. Regardless
of the type or make of aircraft they all call fo r a full
a nd free check of the primary con trol surfaces.
Withou t such a check yo u cannot be sure tha t con trol
of the a ircraft is going to be possible. Whe rever
possible , the con trol surface itself shou ld be ch ecked ,
as well as the moveme nt o f the co ntrol colu m n, to
e nsure cor rect operation. In cases of low a mbien t
lighting, as on this flight, th is check sho uld be
conducted with the a.id of a torch to see the control
su rfaces , or by ma king use of an y available external
lig hting such as the security lights around the tarmac
area. I t may take a little more time a nd effort, but will
be worthwh ile in the long ru n .
An accid ent su ch as this gives tragic emphasis to the
importa nce of these pre-take-off vital actions •
In brief
T he p ilot of a Cessna 172 prepared to take off fro m a
statio n strip before first light. His destination was the
local township, 40 n au tical miles south west, where h e
was to assist with th e u nloading of a truck which was
required fo r back loading at 0700 hours local time.
The re were no r un way lights a vailable a n d
con d ition s at 0550 hours were completely black but
the p ilot, who d id n ot h old an instru me nt rating, was
quite confident knowing th at h e h ad cond ucted this
kind of oper a tion in the past and would be flying into
daylight.
A routine d aily inspection, including a fuel dr ain
check , was carried out with the aid of a torch. T he
pilot set the altimeter to zero feet and , u sing the
la nding ligh ts, lined up the aircraft and took off to the
south , 36 minutes befor e first light. A t 300 feet h e
visually comme nced a r igh t h and turn towards the
town . T he next thi ng he remembered was scrambling
ou t of his ver y be n t ae roplan e.
The aircra ft had struck the ground sh ortly a fter the
lurn was commenced , in a position that would
a pproximate the beginning of a right d own wind leg.
It then cartwh eeled for abou t 70 metres, during
which the fuselage broke beh ind the cabin area. No
evid ence was fou nd to indicate that the aircraft had
bee n other than ser viceable.
I n tu rn ing on to cou rse the pilot d id n ot refer to his
.artificial horizon a nd the turn took him away from
th e east wh ere th ere may h ave been some glimmer of
ligh t. It should be well known that without a visual
horizon su ch an unde rtaking can lead to
disorientation and loss o f control, which probably
happene~ on this occasion . H ad the p ilot been
for mally train ed in nigh t flying, he wou ld h ave
?iscovered tha t it consists to a lar ge extent o f flying by
instrumen ts.
T he p ilot m ay conside 1· himself fortunate that in
th is case the only things broke n were h is aircraft and a
few regu lations •
Aviation Safety Dig est 110 I 23
I
...:I
�As the Captain rotated the aircraft the F10 sighted
th e right hand threshold lights and commented they
were 'looking a bit low'. He could not remember
making any further comment but the Captain
recalled that,just before impact, the F/ 0 said 'You
are going to hit the lights'. Both pilots thenfrlt the
landing gear strike the ground and the approach
lighting.
Touchdown was in a near nor mal landing attitude,
192 metres short of the runway threshold. Six
approach lights, in the last four rows leading to the
threshold, were struck by the main wheels as the
aircraft rolled across the grassed area. The nosewheel
probably touched down on the runway j ust beyond
the threshold. The aircraft remained on the runway
as it slowed down and taxied to th e terminal under its
own power. T he passengers disembarked by normal
means.
DC-9 lands short of runway
At approximately 1342 hours Eastern Summer Time on an afternoon in late Spring, a McDonnell Douglas
DC-9-31 aircraft landed 192 metres short of the threshold of Runway 27 at Melbourne Airport, Victoria.
The aircraft was conducting an Instrument Landing System approach in conditions of reduced visibility
caused by heavy rain. During the ground roll to the threshold, the main landing gear of the aircraft struck
and destroyed six lights in the high intensity approach lighting system serving the runway.
The aircraft was operating a regular public transport flight and there were 91 passengers and a crew of
six on board. No one was injured and the damage sustained by the aircraft was minor.
The flight was operating from Brisbane to Melbourne
with an intermediate stop at Coolangatta. The aircraft
departed Coolangatta at .] l 5 l on an Instrument
Flight Rules category flight plan. Throughout this
stage the Captain flew the aircraft from the left-hand
pilot seat.
As the aircraft approached the destination area,
Melbourne Airport Automatic Terminal Information
Service was broadcasting information Papa. This
contained the following : Runway 34, wind 340
degrees at 25 knots, gusting to 35 knots , QNH 1001
millibars, temperature 22 degrees Celsius, cloud six
oktas at 2500 f eet with lower patches and showers in
area.
At 1334:06 the ai1·craft made contact with
Melbourne Approach Control and was immediately
cleared to descend to 3000 feet on a QNH of 100 l
millibars in accordance with the altitude restrictions
specified in the Distance Measuring Equipment
Arrival Procedures. Approach Control also advised
the aircraft it had 30 nautical miles to run to
Melbourn e, that the runway had bee.n cha nged Lo 27,
a nd that it was to track via the Epping locator and the
Runway 27 localiser. Twen ty seconds after
acknowled ging this instru ction, the aircraft was
advised that the wind was coming around to th e west
at 30 knots.
The rapid change in surface wind was associated
with the p assage of a cold fro nt, crossing the
Melbourne area from west to east at about 30 knots.
The front h ad been forecast to cross Melbourne
Airport between 1400 and 1600. ATC had issued an
Operational Requirement for aircraft a rriving
between l 130 and 1930 to carr y additional fuel
reser ves because of th e weath er conditions associated
with the frontal p assage. The DC-9 carried sufficient
fuel to divert to Sydney.
At 1336: 19 the aircraft was advised tha t the QNH
was now 1002.5 millibars, visibility 2000 me tres in
h eavy rain , wind fro m 240 d egrees magnetic a t 30
knots with gu sts .r.o 40 knots. The aircraft had 18
nautical miles to run a nd was clear ed for ILS final on
Runway 27. Nine seconds later the aircraft was
further advised that QNH was 1005 millibars, cloud
cover six oktas at 1500 feet with lower p atches and
temperature 17 degrees.
As a resu lt of the rapid ch an ges in QNH a nd
surface wind, the Captain con side red there was a
probability of encountering wind sh ear during the
approach. As a precaution h e decided to make a
faster than no rmal approach with only 25 degrees of
flap extended. The calculated la nd ing weight was
40518 kilograms (2709 kilograms under maximum)
a nd the Captain referred to the 90 OOO pounds
(40 823 kilogr ams) la nding weight Data Card to
24 I Aviation Safety Digest 110
obtain an app roach Reference Airspeed for 50
degrees of flap of 122 k nots. He added a 10 knot
increme nt to this figure to allow for the r educed flap
configu ration, and a further 20 knot increment to
compensate for the ad vised stron g wind gradient and
gust effect. He thus arrived at a selected approach
speed of 152 knots. The Captain advised the First
Officer of this decision, but did not otherwise
elaborate upon the manner in which the approach
and landing would be carried o ut.
Over Epping locator at about 3000 feet neither
pilot could see the run way. At a bo ut 2000 feet they
could both see the airport terminal buildings and the
first half of the runway, but not the control tower.
At 1339:58 Melbourne Tower ad vised the aircraft
that it had n o idea of the cloud base but it was quite
low, visibility was 2000 metres in heavy rain, surface
wind 250 d egrees magnetic, 20 knots gusting to 30
knots. Run way and apprnach ligh ting were on stage
five.
At abou t 1500 feet , in increasing rain, the crew
adopted full instrument flight procedures. Both
pilots referred to their ap proach charts a nd verbally
con firmed the approach minima and overshoot
procedure. T he r ain continu ed to increase in
inten sity a nd at Giboul l OOO feel the wi ndshidd wipe rs
were turned on. Both pilots stated the aircraft was
then aligned with the localiser and on glideslope. At
800 feet (400 feet above ground level) the F/ 0 called
the descent ra te, in accordance with standard
comp a ny procedures. To the best of his recall it was
about 650 feet p er minute. He also advised the
Captain that he h ad the high intensity approach lights
in sight. The Captain looked out a nd also saw th e
ligh ts.
From this point both pilots concentrated th eir
attention primarily outside th e cockpit. The Captain
stated h e su pplemented this with instrument cross
checks down to abou t 200 feet AGL, while th e F/ O
stated he stopped mo nitoring his instruments abou t
300 feet AGL. At this last instrume nt check the
Captain recalled th e a ircraft was still close to glide
slope . H e also stated that about 400 feet AGL the
aircraft encountered wind shea r. Both p ilots recalled
approximately 12 degrees left drift at this time.
Visibility ah ead was poor. Despite operatio n o f the
wipers, the rain o n the windshield blurred the pilots'
vision , a nd both stated the approach lights were badly
diffused. Neither could see the runway ahead and
they concentrated on scanni ng for the green
threshold lights.
At an estimated J 00 feet AGL, still without visual
contact with the threshold lights, the Captain stated
he sensed th e a ircraft sinking rapidly. He atte mpted
to counter this by pulling back on the control column,
but did not increase power.
0
0
0
SEALED
BLAST AREA
•
Cl •
9•
GRASS
-
LEFT AND RIGHT MAIN
LANDING GEAR GROUND
MARKS
-~'
•
l0
0
l 0 20 30 40
METR E S
CJ
-
Meteorological information
T he crew of the DC-9 had received all the relevant
enroute and terminal forecasts, including an updated
terminal forecast issued at 1102. This indicated a
surface wind of 340 degrees magnetic at 20 knots,
with gusts to 45 knots, visibility of 10 kilometres or
greater, rain, three oktas cumulus base 4000 feet and
seven oktas altocumulus/ altostratus base 10 OOO feet.
A rapid chan ge would occur between 1400 and 1600
to: surface wind 200 degrees magnetic at 15 knots,
visibility 10 kilometres or greater, rain showers, six
oktas stratus base 700 feet and five oktas cum ulus
base 2000 feet. During th e period 1200 to 1900 there
would be temporary reductions of u p to one h our
duration in visibility to 3000 metres, associated with
thunderstorm activity a nd th ree oktas of
cumulo-nimbus, base 4000 feet. Surface temperature
and pressure over the forecast p e riod were
23/ 16/ 15/ 14 degrees Celsius and
1002/1 004/1006/ 1008 millibars respectively.
Bureau of Meteorology procedu res require that a
fo recasting service be provided in respect of low level
wind shear. Although conditions associated with the
frontal passage indicated a high probability of wind
shear a forecast to this effect was not issued.
Observations at Melbourne Airport at 1300 noted
conditions substantially the same as the forecast. By
1330 the low level cloud had incr eased to seven oktas
at 3000 feet with lower patches. A marked roll cloud
and heavy rain was visible approaching from the west.
About 1334 the front crossed the airport, the wind
backing to 240 d egrees magnetic at 28 knots with
gusts to 39 knots. Approximately one minute later
heavy rain commenced and a total of 12 millimetres
was recorded in the next 20 minutes. At about 1336
the surface pressure rose two m illibars to 1005
millibars over a 30 second inter val.
By 1400 conditions had moderated, and some 20
minutes later the rain reduced to occasional showers,
with visibility of 25 kilometres and no cloud below
1500 feet.
The aircraft was twice advised that visibility was
2000 metres. Aerodrome controllers and
meteorological observer s refer to a series of
landmarks at known distances from the control tower
to estimate visibility. I t is a requirement that when
visibility is less than 2000 metres, Runway Visual
Range is used. This information is obtained by
Aviation Safety Digest 110 I 25
�to 255 degrees mag netic was then made, and this
caused the a ircr aft to deviate left of the localiser by
one dot on the course deviation indicator (each dot
equals 1.25 degrees oflocaliser deviation).
Immediately after this turn the rate of descent
increased to about 1500 feet per mi nu te, and this
expedited closure of Lhe glid eslope. However as the
high descent rate was maintained the aircraft passed
through the glideslope at approximately 38 seconds.
At this time a right turn to h eading 267 degrees
magnetic was commen ced .
Ground facilities
By 30 seconds the aircraft was some two dots below
Runway 27 has a Calvert pattern high intensity
glideslope and approaching the minimum altitude of
approach lighting system with associated runway
700 feel. The descent was halted a nd this a ltitude
lighting, variable over six stages, to I CAO Category 2 maintained until the aircraft was back on glideslope a l
standard. T he th1-eshold is marked by a row of green
about 20 seconds. The d escent was the n resumed at
lights flush with the surface of the runway and spaced an initia l 1-ate of900 feet per minute. Throughout
at intervals across it. The ILS is Categor y 1 standard
this period the IAS remained in the 17 5- 180 knots
with a glideslope angle of three degrees. The
range.
associated middle and outer marker beacons and the
During the last 20 seconds of flight the rate of
Epping locator are aligned with the centreline and are descent increased and averaged some I I 00 fee t per
I 074 metres, 6963 metres and 15760 metres
minute over this period. The a ircraft remained
respectively from the threshold .
approximately on localiser but rapidly dropped below
All navigation aids and lighting systems were
glideslope. The IAS fluctuated do wnwards, but at
operating normally and the minima applicable to this touchdown was still 17 1 knots.
approach were 700 feet ceiling (293 feet above
Runway 27 threshold) and 1200 metres visibility.
Op_erating procedures
despatching an officer to the runway threshoid to
gauge RVR by reference to specific assessment lights.
There was evidence that for a period the visibility
reduced below 2000 metres. At about 1339 the
visibility from the tower was probably about 1100
metres to 1300 m etres, and at 1340 the
Meteorological Observer in the control tower
recorded the visibility as 1500 metres. Howeve r , the
Aerodrome Controller did not despatch an officer to
the Runway 27 threshold to assess the RVR.
Compan y operating p rocedures required cross
Flight path
ch eckin g between the two pilots, and alerting by th e
From the Flight Data Record er trace and
meteorological a nalysis the a ircraft was de termined to pilot not fl ying of IAS variations of five knots from
have passe d through the front at 1340: 50, 70 seconds the selected approach speed and of r a tes of desce n t in
excess of 800 feel p er minute when below 1500 feet
before to uchdown.
above aerodrome level. Aircraft were a lso required to
T h e following reconstruction of the app roach was
be establish ed o n glideslope in the la nd ing
made. All times a re in seconds prior to touchdown .
configuration
at the selected airspeed n ot less than
The aircraft passed over Epping locator at 175
700 feet above a irport le vel.
seconds, d escending through 2950 feel on a heading
The Company's sta ndard instru ment approach
of 268 d egrees magnetic but closing the localiser from
procedure
was the monitored a pproach. In this
the north under the influence of the strong northerly
procedure
the
F/ O fl ies the approach a nd re main s
wind. IA S was about 235 knots a nd decreasing .
'on instruments' thr oughout the approach , even ifthe
Glideslope was captured from below at 165 seconds.
aircraft e nters visual flight conditions and the Captain
Descent continued with mino r deviation s of about
assumes physical control to complete the landing.
half a dot on the glideslope (each dot equals 0. 25
The Company Ope rations Ma nual covered this
degrees deviation) until 95 seconds. During this
procedure, reaffirming the cross ch eck requiremenls
period the localiser was captured and maintained al
an a ircraft h eading of 275 degrees magn etic. The IAS laid out in the general section covering all
approaches. I t also stated that th e moni tored
had continued to decrease but al a slower rate and a l
approach
procedure could be d iscontin ued an y time
95 seconds was about I 80 knots, still some 30 knots
at the Captain's discretio n.
above the selected apprnach speed. T h e aircraft
T he Compan y Flight Training Manual instructed
altitude was about 1830 feet; an average rate of
tha
t VRef be increased in stron g wind conditions b y
descent since p assing Epping locator of 840 feet p er
50 per cent of the gradient wind plus I 00 pe r cen t of
minu te. T he re were still som e 8000 metres Lo run to
the gust factor, Lo a maxim um total of 15 knots. T his
the run way threshold .
maximum h ad been reduced from 20 kn ots some
The ra te of de.scent was then re duced and the
four
weeks prior to the incide nt.
aircraft began to deviate above the glideslope. At the
Both
ma nua ls indicated that land in gs were to be
same time a le ft turn of approximately fi ve degrees
was m ade a nd the aircraft also began to deviate left of made with 50 degrees of flap extend ed. The only
exception was for single-engine approaches wh e n flap
the localiser. T h e Outer Marker was crossed at 83
·extension
was to be limited to 25 degrees. In this case
seconds. At 75 seconds the aircraft encountered wind
the
VRe
f
for
50 degrees flap should be increased by
sh ear associated with p assage of the front. The IAS
I 0 knots a nd there would be a markedly h igher bod y
increased approximately 15 knots to 195 knots over a
angle , of a bouL six degrees, on a pproach . Neithe r
10 second period. T his was accom pa nied by a brief
manual contained inslructions lo be followed when
pause in descent which caused th e aircraft to be
wind sh ear was expected.
disp laced some two dots above glideslope.
T h e first informa tion to indicate a need fo r IFR
The aircraft then entered a desce nt a t about 1200
procedures was at 1336: 19 wh en the aircraft had
f eet per minute and began to turn to the left. Drift to
some 30 ki lo me tres to run , a nd Approach Con trol
the left h ad ceased and th e localiser was closed at
advised of reduced visibility and h eavy ra in . Possibly
.approximately 60 seconds. A more rapid left turn on
26 I Aviation Safety Digest 110
the pilots regarded this s udden d e terioration as a
transitory event. Subsequently they had the firs t half
of the runway in sight from 2000 fee t and this may
have been an influence. I nstrument procedures were
not full y implemented at 1500 feet when the crew
accepted that a visual approach was not p ossible . This
was conside r~d a major facto r in the inciden t. The
monitored a pproach proced ure was no t initia ted , and
the lack of d etailed al ternate procedures in the
Operations Manual cou ld possibly have been an
influ ence in th e resultan t unco-ordinated actions by
the fl igh t crew. This omission was not classified as a
factor in the incident in view of the crew's general
neglect of published p rocedures.
[ t could not be establish ed what cross checks, if a ny,
occurred as requ ired by the Operations Manual.
Eith er the F/ O did no t monitor the instruments, or he
noted the abnormal indicatio ns and elected not to
alert th e Captain, or, h aving issued th e alerts, was
ignored by the Captain . Whichever was the case , it
was evidenL that a major brea kdo wn in crew
co-op eration and co-ordination occurred during the
ap proach .
It was consid ered tha t fi nal app roach shou ld have
been delayed, at least lo ng eno ugh to evaluate the
rapidly ch an ging weather situ a tion , a nd plan a nd
brief appropriate instru me nt a pp roach p rocedures.
The Operations Ma nual implied that the approach
should have been aba ndoned wh en stabili ty,
particularly in respecl of app roach speed, had n ot
been established by 700 feet AGL.
The decision to con tinue beyond the mi nim u m
altitude was depende nt on the Ca ptain's assessment
that adeq uate con ditions existed for visual fligh t, a nd
that fo rward visibility was 1200 metres or greater.
Flight visibility at th e m inim u m altitude could not be
precise ly establish ed bu t was considerably less tha n
thaLn ecessary to fl y by ex ternal r eference a lone. I t
was conside 1-ecl that failure Lo recognise that situatio n
and to initiate a go-around was th e prima r y causal
factor in th e incidenl.
I n conside r ing the circu msta nces of th e fi nal la rge
deviatiou belo w glideslo p e, it is significan t that
neither pilo t mo nito red th e aircraft instruments. By
atternpLing Lolly solely by reference to th e run way
approach lights the crew riske d their j ud gment b eing
in fluenced by illuso r y e ffects resul ting from the heavy
rain o n th e windshidd. Resea rch in to th is
phenomeno n ind icates a d epression of th e 'hor izon '
by up to I: 12. The gradien t from th e 'on glid eslope at
mini mum altitude' point to wh ere the aircraft
tou ched d owu \\·as I: 14. Whilst no t conclusive
evidence of visual illusor y e ffect, it was conside red
this possibility could not be e xcl uded.
Analysis
Ge ne ra l meteorological condi tions were essentia lly as
forecasl. Fron ta l passage was earlier than p red icted .
Grou nd visibility was redu ced to between 1100 a nd
1500 metres at the time the a irc raft made its
approach , rathe r than th e 3000 metres forecast. T h e
Bureau of Meteorology omitted to issue a fo recast o f
wind shea r as was req ui red. This was not considered
to be of sig nifican ce as th e crew were aware o f th e
probability of wind shear on fi na l approach .
T wice d uring th e a pproach the a ircra ft was advised
that visibility was 2000 metres. On the second
occasion the visibility from the tower was probably
1100 to J 500 metres. A specific reason for the
incorrect advice was not established , but probably the
Ae rodrome Controller had restated his initial
evaluation and h ad n ot assimilated the visual cues tha t
indica ted the figure of2000 metres was no lo nger
valid. As an RVR assessment was not made, it was n ot
establish ed ifthe minim u m req uired 1200 meu-es
existed at the time of th e incid e nt. Had an RVR of less
than 1200 metres been determined , then the runway
should h ave been closed. Alternatively, an assessme n t
of 1200 metres or greate r would have permitted
authorisation of the approach a nd landing . The
advice of marginal RVR accompa nying such a
clearance might h ave provided a timely warni ng to
the crew of possible lack of outside reference below
minimum altitude. It was concl uded that the
Aerod rome Controlle r's omission contributed to the
incident, but only insofar as the flight crew was not
provided with secondary information to assist in
assessing the adequacy of landing visibility.
The re were no ab nor mal pressures on the flight
crew to complete the flight with ou t dela y, but the
evidence suggests th at th er e was some h aste in the
manner in which the approach was flo wn. A
non-sta ndard configuration of25 degrees of flap was
chosen and a high selected approach speed of 152
knots calculated. T hroughou t the approach an IAS of
some 20 to 30 knots higher than that selected was
maintained.
It is possible tha t the excessive airspeed reflected a
lack of familia 1-ity with, or consideration of, the
aircraft's performa nce in the 25 degrees flap
configuration. Simulator tests indicated n egligible
difference in body a ngle and requi red power be tween
the 25 degree fl ap/ 170 knot I AS and th e 50 degree
flap / 140 kn ots IAS approaches. If during the
approach th e Captain h ad selected an attitude a nd
power setting equating to the 50 degree flap
configuration with which he was more familiar, then
the aircra fL would h ave ach ieved an airspeed of the
order recorded on the FDR.
T h e use of the reduced flap approach is not a
commo nly accepted counte r fo r wind sh ear. This
p articula r approach , with the wind backin g from the
no nh to the west, encountered a predicta ble
oversh oot shear cond ition. A reduced flap a nd higher
a irs peed would compound th e problem o f recovery as
a g reate r power redu ction wou ld be necessar y to
correct fo r th e u nwa nted e nergy gain. The lack of
1-eference material on wind shear in th e op erator's
manuals lefl th e fo rmation of th e best a pproach
p rocedure to the Cap tain, possibly based on au
incomplete understa nding of the wind sh ear
phenomeno n .
The omissio n o f a pre-approach briefing and th e
delay in checking the app roach charts until about
1500 feet on final ap proach in d icated that the pilo ts
were largely employing non-instrume nt procedures:···
T heir in itial a rrival expecta ncy was p robably based on
in fonn ation Papa, which in d icated visu al fligh t
conditions could reasona bly be expected no lower
tha n 2500 feel.
T he Cap tain r eported that h e 'sensed ' the aircr aft
sink. This was p robably th e resu lt o f wind gust effects.
It seems likely that th e Cap tain recognised a gust
induced sink in sufficie n t time to rotate the aircraft to
Aviation Safety Digest 110 I 27
�approximately a normal landing attitude, but not
sufficiently early to significantly reduce the final rate
of d escent. The F/ O 's warning calls may also have
cau sed the Captain to apply back-control input.
Consequ ently the touchdown was not sufficiently
severe, or in such an attitude, as to cause structural
failure.
Conclusions
The investigation into the incident reached the
following conclusions:
1. A T C provided the aircraft with advice of the
rapidly changing weather conditions at the airport,
except that the minimum visibility advised was 2000
metres when actual ground visibility fro m the tower
was probably in the range 1100 to 1500 m etres.
2. ATC did not comply with procedures that
required the assessment of RVR when visibility was
below 2000 metres, and the determination that RVR
was at or above the specified minimum of 1200
metres before authorising an approach a nd landing.
3. The company's manuals did not contain
procedures to be a dopted when wind sh ear was
encountered or expected. Nor did they contain
procedures to be employed whe n a Captain elected
not to carry out the monitored approach procedure.
4. The Captain elected to make a la nding approach
during th e p eriod of frontal passage and selected a
non-standard configuration of 25 d egrees flap. This
was unsuited to th e pred ictable conditions met.
5 .. A detailed approach briefing was not carried out
pnor to commencement of the a pproach , nor was the
specified Monitored Approach procedure ad opted.
6. The approach was unstable throughout, with IAS
gen era lly some 20 to 30 knots in excess of th e selected
a pproach speed.
7. Wind sh ear associated with the frontal passage was
e ncountered at a n altitude of approximately 1650
feet, about eight seconds after the aircraft p assed over
the outer marke r beacon. As a result the aircraft
became displaced from the glideslop e but th e correct
d escent profile was re-established at abo ut the
minimum altitude.
8 . The approach was 1con tinued below th e minimum
altitude altho ugh external refere nce to safely
complete a visual landing had not been established.
T h e existing flight visibility was less tha n the specified
1200 metres minimum.
9. There was a major breakdown in crew
co-ordination. As a result the flight instruments were
not monitored below the minimum altitude.
10. The aircraft's ra te of d escent increased to
average approxima tely 1100 feet p er minute during
~e final 15 seconds of flight. A n illusor y effect,
ind uced by h eavy rain on the windscreen , and wind
gust activity may h ave contribu ted to this high rate of
d escen t.
Cause
T he probable cause of th e incident was that the
approach to la nd was continued below th e minimum
altitude, wh e n extern al reference was insufficient to
permit the completion of a safe la nding . •
(Condensed from Department of Trr111s/HH"l Incident !11vestigatio11
R port No. 79-2.)
28 I Aviation Safety Digest 110
From the
incident files
Who has control - the pilot-in-command or the
owner?
The aircraft was on a private VFR flight; on board
were the nominated pilot-in-command who held a
private pilot licence, the aircraft owner who held a
restricted PPL and the own er's wife , occupying a back
seat.
The flight proceeded normally from the departure
point to an en route stop for fuel. One hour and 25
minutes after departing fro m the refuelling stop, the
pilot passed a position report to Flight Ser vice with an
estimate for h is destination in another 15 minutes.
Nine teen minutes la ter the p ilot reported that he was
unsure of his p osition. After liaisin g with a cou ntry
police station , Flight Ser vice established that the
aircraft was over an aerodrome abou t 40 na utical
miles sh ort of its destination. The aircraft landed
there safely, nearly an h our after its ETA at the
destina tion.
Subsequen t investigation of the incident revealed
that, after the refuelling stop, there was a
considerable amount of smoke haze which restricted
visibility a long track. Because of this h aze, the aircraft
was ~limbed to 6000 feet; the pilot informed Flight
Service of the amendment from th e pla nned altitude
of below 5000 feet. The pilot-in-command was
navigating the aircraft and the own er was fl ying from
th e left hand seat.
The two p ilots believed they had identified the first
two check points; however, a subseque n t examination
of the fligh t plan sh owed that the first leg o f 26 miles
was covered in 17 minutes, i.e. a grou ndspeed of 92
knots, while the second leg of 33 miles was su p p osedly
covered in 13 minutes, i.e. a groundspeed of 152
knots. On this basis it seems most unlikely that both
check points could have been properly identified.
It is questiona ble that , after the firs t check point,
the pilots obtained a positive fix. Alth o ugh the owner
had not commenced his naviga tion training h e had
read about the rad io compass and h ad been taking
ADF bearings throughout the trip. Instead of
mainta ining fligh t p lanned headings and map
reading correctly, the owner was a ttemp ting to
navigate using the ADF.
The pilot-in-command, although no t formally
trained on the u se of the rad io compass, did know
that wh en tracking to a station it was not satisfactory
just to keep 'the needle on the nose'. This was
apparently wh at the owner was doing. As the fligh t
progressed, the pilot-in-command virtually gave away
the navigation of th e aircraft to the owner.
T h e situation in the aircraft was rath er tense with
the pilot-in-comma nd wishing that th e owner would
turn off the radio compass and con centrate on flying
the correct headings. T he owner was rather insistent
about the way the flight was to be conducted and the
pilot-in-command felt uneasy abou t d isagreeing,
particularly with the owner's wife also on board the
aircraft. Consequently, he virtually relinquished his
responsibilities as pilot-in-command, i.e. to ensure the
safety of the aircraft and its occupants.
It is essential that whenever there are two p ilots
occupying the control seats of an aircraft, the d ivision
of res ponsibilities must be clearly d efined and, in
particula r , it must be understood which pilot is in
comman d. This aspect of flying safety is of paramount
significance when a pilot, other than the
pilot-in-command, has some vested interest in the
aircraft or its op eration.
If you are pilot-in-command, assert you r authority
whenever this is necessary and ensure that you retain
control of the operation of the aircraft at all times •
of the PA system and cabin attendants, if available,
will also ensure that instructions ar e complied with as
required.
The lesson to be learnt from this incident applies
equally to private or commercial operations, in small
or large aircraft. A pre-flight briefing or even a short
PA announcement may have prevented this
passenger's injury. The incid ent could also serve as a
useful example for pilots to present to their
passengers as evidence of the degree of possible
injury which may be suffered if warning signs are not
heeded •
Impatient pilot plus fl at no sewheel oleo results
in suspected control problem
About five minutes after departing Parafield in his
Cessna 206, the pilot advised Adelaide Flight Service
that he was returning because of a suspected rud der
trim malfunction. He confirmed that operations were
otherwise normal. I n accord ance with standard
procedures, an Uncertainty SAR phase was declared
and the Fire Service alerted. T he aircraft landed
normally and the phase was cancelled .
During the investigation it was established that the
pilot had unexpectedly arrived at the servicing
organisation, late in the day, to collect the aircraft and
fly it back to base. Durin g his preflight inspection he
noticed that the nosewheel oleo strut was flat. The
LAME, who had left for his home, was sent for but
the pilot decided not to wait as the aircraft was loaded
with some refrigeration equipment which was
required urgently back at base. The LAME returned
to the airport just as the aircraft was d ep arting.
When the aircraft returned after the incident, the
pilot reported that the rudder and pedals had gone
over to one sid e. The system was thoroughly checked
and it was concluded that, because of th e flat oleo, the
lower-than-normal pressure had prevented the nose
strut from extending and locking in the fore-and-aft
position after lift off. The fact that the nosewheel was
still free to turn prevented the steering bungee from
providin g a self-centring force to the rudder system,
possibly accentuated by air flow over the unlocked
nosewheel.
The n ose oleo was inflated and the system operated
normally. New 'O ' rings were subsequently fitted to
the oleo strut •
Lack of briefing lead s to passenge r injury
The Piper Navajo was on a scheduled service and was
cruising at 1500 fee t when it encountered some
isolated, severe turbulence while passing between two
rain sh owers. One o f the passengers, an elderly
gentlema n , was thrown up from his seat and struck
his head on th e overhead ligh ts, receiving a severe
gash. The passen ger was n ot wearing his seat belt.
Investigation of the incident revealed that the seat
belt sign had been illuminated throughout the flight
but the pilot h ad not briefed the passengers about the
use of seat belts e ither before flight or over the public
add ress system during flight. There was no cabin
atte ndant on board . T h e injured passenger suffered
from p oor vision as a result of a past double cataract
eye operation . H e wore dark glasses and could not see
the seat b elt sign. It a ppears that he had not wo rn his
seat belt a t a n y stage of the flight. After the aircraft
landed a doctor attended to tlle passenger's injury
which required twelve stitches.
T h e impor tant lesson arising from this unfortunate
inciden t is th at a ny p ilot in charge of an aircraft
carrying passen gers should ensure that all means
possible are used to a lert them to hazardous
situation s. Preflight briefing on the use of seat belts,
observation of warni ng signs, use of emergency exits,
etc. , should be conducted before every flight. Never
assume tha t passengers know about these things. Use
DURSTIN by Russ Day
(courtesy of Flight Crew magazine Spring 1979)
G~E.N eR.Ass...
"-'f:
WAR/<\ BREEZES . • ·::
'
Aviation Safety Digest 11 O I 29
�Survey of accidents to
Australian civil aircraft 1978
The Australian aviatio n industry is obliged to report
all accide nts a nd incidents involving civil aircraft, and
the De partme nt's air safety investigation system is
based on this pre mise. The article 'Air Safety incident
reporting - the Australian system' in Aviation Safl'ly
Digl'st I 09 expla in ed the way in which accident and
incident reports arc stored and used.
One source of accident prevention information is
the statistical analysis of r ecorded accident/ incident
data. A Survey ofAccidents to Australian Civil A ircraft is
published annually by the Air Safety Investigation
81-anch of the Department; the 1978 edition was
rece ntly released and is available from o utlets of the
Australian Governme nt Publishing Service. IL
contains a wealth of statistical d etail in respect of the
1978 accident record , including types of accident,
pilot experie nce, assigned factors and so o n, for
airline, ge nera l aviation and gliding operations.
The Su r vey also contains a section devoted to a
review of accident rates and activity data over past
years for a ll categories of airline a nd ge neral aviation
fl ying, thus giving an indication of the changes which
have occurred in flying activity and accide nt rates
over th e p ast ten yea rs. The 1978 Survey marks a
departure from previo us editio ns in that accidents to
Australian registered aircraft based in Papua New
Guinea prio r to that country's inde pe ndence in 197 5
have now been removed from the statistical
p resentation. The result is a mo re accurate picture of
trends applicable to p1-esent Australia n operations,
and our reade rs may be imerested to see the grap h
and tables presented h e re.
The graph in particular gives a picture of the
overall trends in general aviation. Five year periods
are used for trend assessme nt because there can be
Airline operations
Accidents, aircraft damage, injuries and accident rates -1974-1978
substantial random fluctuations in accident numbers
from yea r to year, as ma y be seen from the tables.
General aviation activity has increased at a rate of
about six p er cent p er year ove1- th e pe riod covered by
the graph and the accident rate p er J00 OOO hours
flown has decreased at about five per cent per year.
Provisional figures for 1979 indicate that this trend is
be ing maintained.
The following data refers o nl y Lo ai1-crart acciden ts, the
de finition of an accide nt being:
An occurrence associated with the operation o r an
aircraft ll'hich takes place betwee n the time that a n y
person boa rds the a ircraft with the inten tion of flight
until such time as all pe rsons have disembarked, in
which,
(a) a person is fatall y o r seriously i1~j ured as a result
of being in or upo n the aircra ft or by direct
contact with the aircraft or anything attached
thereto, except wh e n the injuries a re from
natural causes, a re self-inflicted or inflicted by
other p erso ns, or whe n the injuries are to
stowaways hiding outside the a reas n ormally
available to the passengers and crew; or ,
(b) the aircraft incurs substantial damage or is
destroyed; or,
(c) the a ircraft is missing or is completely inaccessible.
(A n aircraft is considered to be missing whe n the
official search has been terminated a nd the
wreckage h as not been located.)
Five year averages of general aviation accident and fatality rates.
1969-78
7.0
6.0
••
••
••
5.0
••
MILLIONS
HOURS
TOTAL
4.0
3.0
~
.._..._.._.,._ .__
FATALITIES
-.--------~._,
2.0 -TOTAL
.
PER FATAL
--~--._._
ACCIDENT
.....
~--~~~--..---
10 OOO
HOURS
-·ooo
•
ACCIDENT
--
ACCIDENT
--~..-.
RATE PER
--·-
FATAL
...
RATE PER
·-
100
HOURS
Accidents
Involving fatalities
Involving serious injury
Involving minor/no injury
Total
Aircraft damage
Destroyed
Substantial
Minor/none
Fatalities
Passengers
Crew
Total
Fire after impact
Fatal accidents
Non-fatal accidents
Injuries
Fatal
Serious
Minor/none
Hours flown {thousands)
Accident rates
(per 100 OOO hours flown)
Total
Fatal
Number of aircraft on
register at 30 June
1974
1975
1976
1977
1978
0
2
1
3
1
1
3
5
0
0
0
0
0
0
0
0
0
0
0
1
2
1
3
0
0
0
0
1
0
0
0
0
0
0
0
8
3
11
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
155
399.4
11
1
220
393.1
0
0
0
357.0
0
0
381
362.6
0
0
0
370.4
0.80
0
1.35
0.27
0
0
0.29
0
0
0
157
156
151
145
1974
1975
1976
1977
234
17
190
12
243
19
221
19'
249
27
33
199
4
28
162
2
32
21 4
0
30
188
4
49
199
2
18
21
0
12
15
0
21
32
0
18
20
5
26
26
6
39
18
489
27
21
405
53
13
542
38
12
457
52
31
544
0
1
3
0
0
0
0
1
0
5
5
3
6
0
5
6
1 150.8
6
4
1 206.8
7
5
1 346.6
4
2
1 512.8
136
General aviation operations
Accidents, aircraft damage, injuries and accident rates -
Accidents
Total
Fatal
Aircraft damage
Destroyed
Substantial
Minor/none
Fatalities
Crew
Passengers
Others
Injuries
In Aircraft
Fatal
Serious
Minor/none
On Ground
Fatal
Serious
Minor
Fire after impact
Fatal accidents
Non-fatal accidents
Hours flown (thousands)
Accident rates
(per 100 OOO hours flown)
Total
Fatal
Number of aircraft on
register at 30 June
1974-78
20.33
1.48
3 887
15.74
0.99
4 113
18.05
1.41
4208
14.61
1.19
4 726
1978
10
6
1 518.4
16.40
1.78
5 250
*Includes one suicide; not included in accident rates
.....
3
1970-7
28 · r1.viation Safety Digest 110
1971-75
1972-76
1973-77
1974-78
Aviation Sarety Digest 11L, · '29
�
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Aviation Safety Digest, number 110 (1980)
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110
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1980
-
https://collections.heritageoftheair.org.au/files/original/e5aaf52b820cb2c38bd303618cacc08d
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PDF Text
Text
109/1980
•
1 es
I
Department of Transport
�Contents
I
--
•
•
~·
I•
• J
..
•
3
Carbon monoxide poisoning
6
Electronic checklist for general aviation
aircraft
8
Flight deck management
9
Propeller feathering on light twin-engine
aircraft
10
Low level turbulence
13
Unpredictable birds
14
Air safety incident reporting - the Australian
system
16
An unreported incident
17
Selected incidents
19
Pilot contribution
20
Corrosion prevention for piston engines
21
Unfamiliar navigation equipment
22
Servicing older helicopters
23
Polarised instrument glass
24
Some thoughts from a Met. man
25
Fuel ice
26
The man on the other side
28
MD and the jet fuel
30
Learn to say 'No'
Front Cover
An Airbus A300 in the livery of the manufacturer, Airbus lndustrie,
at Melbourne Airport.
- p hotograph courtesy of TAA
•
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries should be addressed to the Assistant Director (Sales and Distribution), Australian
Government Publishing Service, P.O. Box 84, Canberra, ACT 2600.
Subscrip tions may also be lodged with AGPS Bookshops in all
capital cities.
.,
(
(
~
..
J
Change of address and distribution enquiries:
Readers on the free distribution list should contact the
Publications Distribution Officer,
Department of Transport,
P.O. Box 18390, Melbourne, Victoria 3001.
@ Commonwealth of Australia 1980. The contents of this publication
may not be reproduced in whole or in part, without the written authority of the Department of Transport. Where material is indicated to be
extracted from or based on another publication, the authority of the
originator should be sought. The views expressed by persons or
bodies in articles reproduced in the Aviation Safety Digest from other
sources are not necessarily those of the Dep artment.
Reader contributions and correspondence on articles should be
addressed to:
The Assistant Secretary (Air Safety Investigation),
Department of Transport,
P.O. Box 18390, Melbourne, Victoria 3001 .
RM77/30217(5) Cat. No. 79 9266 7
Printed by Ruskin Press, 552-566 Victoria Street, North Melbourne,
Victoria.
Note: Metric units are used except for airspeed and wind speed
which are given in knots; and for elevation, height and altitude where
measurements are given in feet.
Back Cover
Sunset at Alice Springs - a DoT Fokker F-28 calibration aircraft at
the end of a day's work.
Inside Back Cover
A capital city approach and departure cell, radar conlrollers in the
foreground and procedural controllers to their right.
2 / Aviation Safety Digest 109
-
Aviation Safety Digest is prepared in the Air Safety Investigation
Branch and p ublished for the Dep artment of Tra nsport through the
Australian Government Publishing Service, in pursuance of Regulation 283 of the Air Navigation Regulations. It is distributed by the
Department free of charge to Australian licence holders (except
student pilots), registered aircraft owners, and certain other persons
and organisations having a vested operational interest in Australian
civil aviation.
Subscribers should contapt the Australian Government Publishing
Service.
r
The occupants of modern aircraft rarely suffer
from carbon monoxide (CO) poisoning and
consequently the danger it presents is often
overlooked. However, the circumstances of a
recent incident involving two pilots in a Cessna
150 warrant a r evision of our knowledge of this
insidious hazard.
The Chie f' Flying Instructor of a norlhern NSW
fl ying school tells the slory:
'Earlier this yea r, I was to give a student pilot a
training session on steep turns, stalls a nd forced
landings. We departed al a bou t 0900 hours local
time and climbed to 2000 feet, beneath the base o r
the heavy, overcast cloud. The stude nl practised a
few steep turns al 45 degrees of bank bul he had
considerable difficulties maintainin g the correct.
attitude. I attribuled this to the lack of a clearly
defined visual horizon.
'The student p ilot then commented o n the "weird
e ffects of gravity" a nd this p rom pted me to
demonstrate a series of 60 degree banked turns to
show him the effects of g rav ity. Following this
d emonstration th e student atte mpted a similar turn
but became disoriented and it was necessar y for me
to take over th e controls a nd r eturn the aircraf't to
straight and le vel flight. l noticed that the student
appeared to be unusuall y distressed and I decided
to conclude the flight with a practice forced
landing.
'Closing the throttle, I return ed the controls to
the student for a la nding on the aerodrome. H e set
the aircraft into a glide and turn ed o n lo
downwind. The base turn was flo wn no rmall y but
from that point onward the student's judgement
and manipulative skills d eteriorated rapidly. I
repeatedly instructed him to increase power but
instead he selected full flap wh en the aircraft was
•
very low on fin al ap proach and the airspeed was
below 45 kn ots.
'I cannot remember a nything specific after
hearing the student mutter something li ke ··1 can't
land ... ".
'Witnesses o n the ground observed the aircra ft
p ass very low over a large tin shed nea r the
threshold and land about 300 feet before the
threshold markings. The aircraft taxied to the
normal tie down point where we disembarked and
walked Lo the clubhouse. I we nt back Lo the aircraft
with a scr ewdriver a nd opened the cow ls to loo k a t
the e ngi ne, then , realising that I didn't kn ow what I
was doing, I returned to the clubhouse and sat
down.
'A fter a short pe ri od of time the stude nt left the
clubhouse and started to walk about 50 metres to
his car but h alfway there he lost his balance and fell
o n ro another parked car. He paused for a while
then made off towards his car agai n but walked into
a telegraph pole. He held on to the pole for a while
rhcn sat on the ground . H av ing watched a ll this
happen , a ppa rentl y unconcerned , I eventua ll y made
m y way over to him and helped him to hi s car.
'About this time rh e local veterinary surgeon
arrived and realised something was wrong. We were
not ver y rational in explaining the problem. I told
him I s uspected CO poisoning a nd the vel.
suggested we go to his stll"gery for oxygen. l
remembered there was oxygen in a Navajo parked
nearby a nd we made our way Lhere. Even after
breathing oxyge n the student was drifting in and
out or consciousness so we took him to the local
hospital whe1·e he was admitted to inte n sive care.
Blood tests su bsequentl y revealed that h e had in
excess of 10 per cent carbon monoxide poisoning.
It was two weeks before he fully recovered.
Aviation Safety Digest 109 I 3
�'Inspection of the aircraft revealed that three
exhaust gaskets had failed and the sock around the
pilot's left rudde r pedal steering rod had split. This
had allowed gases from the engine nacelle to enter
the cockpit.
'There is no doubt that we were both suffering
from CO poisoning and the total flight time
involved was only 17 minutes. Perhaps the saving
grace in this instance was the fact that I had the
upper right hand air vent open and pointing at my
face whereas the student's was pointing at the
windscreen. Although I do not specifically
remember landing the aircraft there is little doubt
that I did ... even if only from habit! '
The occurrence of this incident has prompted us to
reprint the following adaptation of an FAA
Advisory Circular on the subject of CO
contamination in aircraft.
General
Carbon monoxide is the produce of incomplete
combustion of carbonaceous material. It is found in
varying amounts in the smoke and fumes from
burning aircraft engine fuels and lubricants. The
gas itself is colourless, odourless, and tasteless but is
usually mixed with other gases and fumes which
can be d etected by sight or smell.
When carbon monoxide is taken into the lungs, it
combines with haemoglobin, the oxygen-carrying
agent in blood. The affinity of the haemoglobin for
CO is so much greater than for oxygen that oxygen
starvation results. Oxygen starvation of the brain
reduces a person's ability to reason and make
decisions. Exposure to even very small amounts of
CO over a period of several h ours will reduce a
pilot's ability to operate an aircraft safely. Long
exposure to low CO concentrations is as hazardous
as short exposure to relatively high concentrations.
Susceptibility to carbon monoxide poisoning
increases with altitude. As altitude increases, air
pressure decreases and the body has difficulty
getting enough oxygen . Add carbon monoxide,
which further d eprives the body of oxygen, and the
situation can become critical. Inhalation of tobacco
smoke also introduces CO into the body in
significant quantities.
Many light aircraft cabins are warmed by air that
has been circulated around the engine exhaust
pipes. A d efect in the exhaust pipes or cabin
heating system may allow carbon monoxide to enter
the cockpit or cabin. The danger is greatest during
the winter months when the temperature is such
that use of the cabin heating system becomes
necessary ar.d windows and vents are closed. But
there is danger at other times too, for carbon
monoxide may enter the cabin through openings in
the firewall and around fairings in the area of the
exhaust. system.
Symptoms
Early symptoms of CO poisoning a~e feelings of
sluggishness, being too warm and ughtness across
the forehead . The early symptoms may be followed
by more intense feelings such as headache,. .
.
throbbing or pressure in the temples and nngmg m
the ears. These in turn may be followed by severe
4 I Aviation Safety Digest 109
headache, general weakness, dizziness and gradual
dimming of vision. Large accumulations of CO_ i~
the body result in Joss of muscular power, vom1tmg,
convulsions and coma. Finally, there is a gradual
weakening of the pulse, a slowing of the respiratory
rate and ... death I
What to do about exhaust odours and symptoms
If you smell exhaust odours or begin to feel any of
the symptoms previously men tioned , you should
immediately assume carbon monoxide is present
and take the following precautions:
Immediately shut off the cabin air heater and
close an y other openings that might convey the
engine compartment air to the cabin.
Open a fresh air source immediately.
Avoid smoking.
Inhale 100 per cent oxygen if available.
If you are flying, land at the first opportunity
and ensure that any effects from CO ar e gone
before further flight.
Determine that CO is not being allowed to enter
the cabin because of a defective exhaust,
unsealed opening between engine compartment
and cabin, or an y other factor. ·
•
•
square and 2.5 mm thick. The porous plastic
contains a chemical that changes colour upon
contact with carbon monoxide. Measurement of th e
CO present is made by exposing the porous plastic
disc to the a tmosphere to be tested for a specific
p eriod of time, then comparing the disc colour to a
colour standard on the instruction card . A reading
of 'safe', 'marginal', or 'd angerous' is d etermined.
Although not as accurate as the first type, its
accuracy is adeq uate, and it has the ad vantage of
being light in weigh t and low in cost.
Design requirements governing the airworthiness of
aircraft include standards aimed at keeping cockpit
and cabin air contamination within safe limits.
Under these standards, the maxim um acceptable
concentration of carbon monoxide in air is 50 ppm .
Carbon monoxide contamina tion checks are carried
•
•
•
Is your aircraft a death trap?
Concentrations of CO exceeding one part in 20 OOO
parts of air (0.005 per cent) are hazardous. To
prevent an aircraft from becoming a deathtrap, a
thorough examination of the exhaust manifold and
heater assembly should be conducted at regular
intervals, and whenever CO contamination of the
cockpit or cabin is suspected , because cracks and
holes may occur in a relatively short time.
Some aircraft manufacturers recommend that
exhaust and heater systems be inspected as often as
every 25 hours of flight time. Carbon monoxide in
the cabin or cockpit has been traced to worn or
defective exhaust stack slip joints, exhaust system
cracks or holes, openings in the e ngine firewall,
blowby at the e ngine breather, defective gaskets in
the exhaust manifold, d efective mufflers and
inadequate sealing or fairing around strut fittings
on the fuselage.
It is a good practice to supplement inspec?ons of
cabin heating and engine exhaust systems with_
operational CO detection tests. Carbo_n mon~x1de
tests are reliable and may be accomplished without
any disassembly operations. T ests should be
conducted on the ground and in flight to determine
the extent of CO contamination. These tests should
be conducted with the cabin heat both on and off.
CO detection equipment
There are two types of indicators currently available
that are practical for determining the concen~ration
of CO in the air at any given time. One type 1s
operated by drawing a sample of air into a
transparent tube containing material which changes
colour according to the amount of CO present. An
accurate measurement of the CO in the sample may
be made by comparing the colour in the tube to a
colour standard provided with the instrum ent.
Another type of CO indicator consists of a porous
plastic disc about the size of a 10 cent piece
mounted in a solid plastic plate about five cm
o ut as a routine part of the type certification for all
new aircraft types brought on to the Australian
register and for other aircraft which have
undergone major modification, or are engaged in
special operations such as support or parachute
dropping, which involve the removal of doors or
windows.
'
If at an y time, an owner or pilot has reason to
suspect carbon monoxide contamination in his
aircraft, he should ad vise the Department of
Transport a nd arrange to have the cabin air
sample-tested under operational conditio ns. These
checks are simple and reliable, and the time
involved in conducting them is small indeed especially whe n compared with the possible
consequences of exposure to car bon monoxide in
flight.
I
Hai:I your exhaust system
inspected lately ?
I
..
•
Aviation Safety Digest 109 I 5
-
••
•
-
•
�Electronic checklist for
general aviation aircraft
Pilots o f lar ge, sophistica ted aircraft a1·e fa milia r
remains on until all ch ecks a re completed ,
with the a utomatic ta ke-off warning syste ms lilted
whe reupon it exting uishes and the green comes on
to some a ircra rt to warn the flight crew that a n
indicating that all pre-ta ke-off checks are complete
impo rtant control is not correctly positioned for
and the take-off may begin .
ta ke-off. Controls such as sp oilers, flaps and slars,
control locks, e tc., are connected electricall y into th e Pre-land ing check
As soo n as the p ilot sta rts h is p re- la nding ch ecks,
system so tha t when the throttles a re ad van ced to
the green light goes out, the red comes on and stays
ta ke-off powe r, an au ral a nd / or visual warning is
on until a ll ch ecks ar c do ne (with the possible
operated .
excep tion of 'cancel SARWATC H ') at which stage
Ma ny ge ne ral aviatio n pilots in the p ast wo uld
have relished such a luxur y but have had to re ly on the red ligh t goes out a nd the g reen a nd am ber
ligh ts come on; th e green ind icates that the pilot
th e u se of memory, mne monics and printed
may proceed to la nd but the ambe r indicates that
checklists to avoid an occurre nce during take-off as
post-landing checks still need to be done.
a result o r a n incor rectly set control.
One ope ra tor based at Mou nt H age n in Papua
After-landing ch eck
New Guinea has progressed a long way towa rds
When these checks have been do ne the amber ligh t
overcoming the problem and has develop ed a u
extinguish es lea ving onl y the green light on to
electronic ch ecklist, now fitted to most or his fleet o f indicate to th e pilot tha t he is clear to shu t down
GA a ircraft. Missionary Aviation Fe llowship
th e engine.
o pe ra tes 18 a ircraft , mostly Cessna 185 and 205
T he p re-landing logic circu its are so arranged
models, a nd h as been progressively eq uipp ing them
that should the pilot elect to cancel SARWATCH
since 1976. T h is checklist is not limi ted lo on ly th e
af ter la nd in g, he will still get the green and ambe r
p re-ta ke-o lT checks, but a lso ope rates fo r
lights for landi ng, bu t th e a mbe r re mains on a t the
pre-land ing and after-la n din g checks, includin g
comple tion or h is afte r-landing ch ecks to remind
SAR WATCH cance llation. As evid ence of the
hi m to can cel SARWAT C H by rad io a nd the n
usefu lness o f the checklist, not on e or the ai rcraft so ope ra te the appropriate switch in the pre-land ing
ri u cd has been involved in a 'failu re to cancel
section . This will then exting uish th e a mber light,
SAR WATC H ' incident in approximately 12 OOO
indicating that the checklist is complete.
la ndings at non-controlled aerod romes - a n
Pilots using the eq uipme nt h ave fo und the
e n viable record .
checklists esp eciall y helpfu l wh en doin g man y
T he checkl ist consists o f a row of I 0 toggle
consecutive sh ort fl igh ts wh e re it is comparatively
switch es a ppropria tel y labelled , three lights
easy to fo rget to comple te a ch eck.
colo ured red , amber a nd green , and a tra nsistorised
As previo usly stated , this electronic checklist has
logic circu it. The .switches a re progressively turned
overcome a lot of proble ms associated with
u p to complete the pre-take-o ff check and the n
incompleted checks. H owever, un like the full y
turned d own to complete the p re-la nd ing a nd
a utomatic systems in large, tra nsport aircraft, the
after-la ndin g ch ecks. T he equ ip men t is ve ry re liable system is still fa llible in that the pilot must caJTy out
because its e lectronics have been kep t simple a nd
the particular check or make th e necessar y control
there is no complicated logic in te rface with the
selection before ope rating th e a ppropriate checklist
aircraft's syste m to malfu nction.
switch , oth erwise the system becomes meaningless.
It is still p ossible with this syste m to complete the
ch ecklist eve n though th e ch eck was n ot physically
Operatio n of the checklist
co nd ucted . Obviously the checklist is only an aid to
th e pilot a nd is very useru l to someone wh o wants
Pre-take -off ch eck
to operate professio nally; th e re is, howeve1·, a limit
As soon as th e pre-ta ke-o ff checks arc sta rted, th e
to wha t can be d on e to make a p ilot complete his
g reen light goes ou t and the red light comes 0 11 a nd ch ecks if he is n ot r eall y inter ested .
6 I Aviation Safety Digest 109
Above: A typical installation of the electronic checklist on the instrument panel of a MAF-AIR Cessna.
Consid e ration was given during the desig n stages,
to the ma ny p ossible ways to 'pilot p roof the
checklist and prevent the p roblem mentioned
above. The present desig n is the fin al outcome and
is conside red to be th e break-even point in term s o f
cost a nd reliability versus 'pilot proo fness'.
T his check-list system h as th e ad va ntage over
some oth e r me mor y aid s that, shou ld the check
seque nce be tempor arily inte rrup ted, th e position of
the switch es sh ows the pilot wha t point he had
reached in his checks a nd h e ma y carry on l'rom
the re. I r ther e is a major in te rruptio n, such as the
necessity to shut down the engine, the switches
sho ~ ld be r e-positioned and th e checks sta rted
aga rn .
Anoth e r ad va ntage with th is system is that,
shou ld a pa rticula1· set of circumstances necessita te a
d e parture from the placarded sequence, ch ecks ca n
be d o ne in a n y sequence a nd the switch position
shows the pilot which ch ecks have not been
completed . T h e seque nce used by Missiona ry
Avia tio n Fello wsh ip has been developed to suit the ir
particu la r operations.
FuLUrc modifications under consid era tion include
the foment to retractable la n d ing gear aircraft. I t is
p roposed th at the circuitry wou ld be d esigned so
tha t th e pre-la nding (ch ecklist) green ligh t could not
illumin ate un til the la nding gear d own wa rnin g
light had ill uminated.
If an y of ou r readers are in terested in furth er
details abou t the electronic checklist they should
write to:
The Manager ,
MAF-AIR Se rvices Pty. Ltd. ,
Airport,
Ballarat, V I C 3350.
T he ma nage r will be a ble lo supply circuit a nd
constructio n d etails, a pproved drawings and furth er
infor mation as requ ired. T h e company d oes not
intend to p ate nt or comme rcia lly manufactu re th e
equ ipmen t so there arc no restrictio ns o n its
construction by in te rested pa n ies. Requests to
purchase the completed checklist, ready for
installation , will be conside red .
Before fitting this or similar equipme nt to your
aircraft you a re advised to co ntact the Airworthiness
Branch of yo ur nearest De pa rtme nt of Tra nsp ort
Regiona l Office to ens ure compliance with a ll
require me nts •
Aviation Safety Digest 109 I 7
�Flight deck management
Following an accident involving a Douglas DC-8 jetliner near the Portland International Airport,
Oregon, USA, the National Transportation Safety Board linked a common element with several other
air carrier accidents of recent years. They subsequently recommended better flight crew
indoctrination in the principles of flight deck management.
Th e DC-8 , carrying 18 1 passen gers and a crew of
eight crashed 10 km south-cast of the airport while
attempting a landing in December, 1978.
The Boa rd concluded tha t the probable cause of
the accide nt was 'the failu re of the captain to
properly monitor th e aircraft's fue l state a nd to
p rope rly res pond to the lo w fuel sta te and the crew
members advisories r egarding the fuel slate. This
resulted in fuel exh austion to all engines. His
inattention r esulted from preoccupatio n with a
landing gear ma lfunction a nd preparations for a
p ossible landing emergency.
'Contributing to Lhe accide nt was the failure o f
the other two flight crew m embers eilher lo full y
comprehend the criticality of the fuel state or to
su ccessfully communicale thei r concern to the
captain .'
The seque nce of events that led to Lhe crash
began wh e n the landing gear was lowered fo r the
la nding approach , tr iggering unusual so unds an d
jolting the aircraft. In the cockpit, a green ligh t
indicated the nose wh eel was d own but there was n o
green ligh t indication on the main landing gear.
Despite the lack of a green lighl, o the r visual
indicalors on the wing srn·faces signalled the main
gear was d ow n a nd locked.
Althou gh procedures for ch ecking a n iiTegular
gear p roblem are brief, the crew wailed 28 minu tes
before it contacled m ainte na nce staff by radio to
as k fo r guidance . T h e crew was then told tha t it
a ppea re d that they h ad done ever ything to assu re
th e integrity of th e landin g gear.
T h e Boa rd said it felt tha t al Lhat time - 30
minutes be fore th e crash - the capta in could have
made a la n d ing attem pt. H owever , the flight
continued its holding pattern a nd th e fligh t
attenda n ts continued briefing the passe ngers on a
possible a bnormal landing. In total, the aircra h
remained in a hold ing patte rn for more than one
hour fro m th e time it re ported a la nd ing gear
pro blem.
'Dur in g this period , th e cap tai n failed to relate
Lime , disla n ce fro m the airport a nd th e aircraft's
fuel state as his atte ntio n was directed completely
toward the d iagnosis or th e gear problem a nd
prep aratio n o r th e passen ge rs for an emerge ncy
landing. The gea r p roble m had a d isor ganizing
effect on the ca p tain 's perfo nnance,' the Board
said. 'As fo r the first officer a nd th e flight en gineer,
n either con veyed an y concern about fuel exh austio n
to the captain until the acciden t was in evitable.'
H owever , after il became a p parent to the cr ew
that en gine fl ame-ou t was im mi nen t, the cockp it
conversation ind icated that th e ca ptain may have
been confused as to the a mount of fuel which
actually remain ed. About six minu tes before all th e
8 I Aviation Safety Digest 109
engines stopp ed, the cap tain stated th at th ere was
I OOO po unds of fu el in th e no. I tank, an d the
second officer agreed with hi m .
Additional remar ks were mad e at th is time by the
captain d escribing the fu el gauge ind ication as.
changing fro m I OOO p ounds to zero poun ds. Smee
this gauge does not change its in d icatio n from I OOO
pounds to zero directly, but decreases in increments
of 100 po un ds, the cap tain m ust have read the
gau ge inco rrectly. Actu all y, the indication Lh at h e
described is that of a gauge change from I 00
pounds to zero pounds.
In addition , the Safety Boa r d learned that the
op erato r had recenlly cha nged Lhe .fuel qu antity
gauges on this aircraft from a direct reading
digital-type to a three-figure indicator that musl be
multiplied by a facto r of I 00 to get Lh e actual fuel
tank values. The new total fuel gauge, with an
identical d isp lay of the sam e three-figure
presen talio n as th e individual ta nk gau ges, must be
mul tiplied by a facLOr of 1000 to get the actu al total
fuel value.
The Safe ty Board b elieves that the design can
cause confusion and as a parl of its
recommen dations r esulting fro m th e accident u rged
the Fede ra l Aviation Administration to ensure th at
the d iffer ence in fue l-quan tity measuring
instrume nts is stressed during flig h t crew Lra in ing
and thal Lhe crews using the n ew syste m arc m ade
aware of the possibility of misinte rpreting the gauge
readings.
T his accide n t is simila r in some respects to several
other previous air car r ier accid en ts invesLigated by
the Safety Board. Alth ough th e circumstances
surro undin g these accid en ts were d iffe re nt, they
have one ele ment in common. In each case the crew
concep t failed as Lh e e n ti re fl igh Lcrew ei the r
fixa ted to a degree on the problem at h and and
the reby failed to monitor the fligh t's progress
proper ly, or th e fi rst officer's or second o ffice r's
inp uts on the flight d eck were not ad equately
communicated to or rece ived by Lhc captain.
T he Safety Board has learned in fo rmall y that
severa l air carrier ope rators have recognized a need
fo r greate r e mphasis on fligh t crew man agemenl in
their fligh t o pcralions and h ave u ndertaken. t~c
developme nt of some form of comma nd trammg
program . Ge nerally, these efforts a p pa rently
.
include pr inciples of lead ersh ip , management skills,
human relations and p roblem-solving in th e
operalio na l envir onment.
Additionally, the National Aerona utics and Space
Administra Lion , in the cour se of its ongoing
research program on human factors and aviation
sa fety, h as recogn ized the importa nce of fligh t deck
resou rce managemen t in air carrier fl igh t
operation s, and is cu rren tly wor king closely with
induslry rep resenlatives to encou rage the
d e velopme n t of training p rograms which ad dress
rhis subj ect.
The complex ily of current air carrier fligh t
operation s imposes conside rable de ma nds upo n
flight crew me mbers, p a r ticularly unde r high
wo r kload condition s. Mo reover, acciden t
investigation experie nce, as mentioned above,
ind icates that ca ptains have failed , sometimes at
cr itical points in a !ligh t, to ta ke ad vanLage of
important resources th at arc available lo them.
Th ese resou rces h ave incl uded not only available
equip me nl and supporting services, bu t also the
assislance of a co-ord ina ted cr ew; fi rst a nd second
officers have not, in some cases, ad equately
monito red fl ight progress, positively comm u nica ted
their obscrvalions or actively assisted th e captain in
his ma nagemen t of the fligh t. There fo re, Lhe Safety
Board believes Lhat pr esen t effor ts to foster
im proved flig h t deck manageme nt shou ld be
ex pand ed lo include all air ca rrie r operators.
Accord ingly, the National T ra nsportation ,,5afety
Board recom me nded that the Federal Aviation
Administration ur ge operators to ensure th al Lheir
flight cre ws a r e indoctrinated in principles of fligh t
deck resource manageme nt, with particu lar
emphasis on the mer its of p artici pative management
fo r captains and asser tiven ess train ing for oth er
cockpit crew members.
The biller experience o f this accidenl h as lessons
for reflection by a ll crew members. T h e points
made by the NTSB deserve sp ecia l consideration
for the reason that they highligh l proble ms Lhal
have been obse rved in othe1· accid en ts •
Propeller feathering on light
twin-engine aircraft
The following article was produced as Aeronautical Information Circular 9/1 979 by the Civil Aviation
Authority, United Kingdom. It concerns the possibility of feathering difficulties with propellers fitted
to light twin-engined aircraft. The message it contains is applicable anywhere in the aviation world.
Most fea th e ring p ropellers (h ydr a ulicalJ y actuated ,
constanl sp eed , such as so me H a r tzell a nd
McCauley typ es) fitted to twin piston-engine lighL
aircraft a re d esign ed in such a way that it is not
possible to fealh cr the blad es below a certain low
r pm (typically 700- l OOO rpm) .
T h is is because a l Lhese low rp m centr ifugal
latch es op erate to hold th e blades in fine pilch to
ensure tha t wh e n the engine is shu t dow n on the
ground , the subseque nt restart is not made with th e
prope llers feathered.
In cases whe1·e th e nor mal windmilling rpm al
low a irspeed m a y fall low e no ugh to p reven t
feath er ing, the Fligh t Man ual, O wner's Handbook,
o r Pilot's Ope rating H andbook warns the pilot th at
feathe r ing cannot be accomplish ed below a cer tain
rp m. H owever the full im plications or the situation
m ~y not a lways be clear, a nd othe r factors of which
a pilot sh ould be aware a re:
(a) In the even t of an en gine fail u re caused by a
major mechanical fa ult (e.g . seizing beari ngs
d ue to loss of oil), the rale of d ccclera lion of
the engine ca n be rapid and it is th us
imperative thal Lhc pilot take immediate action
to fea ther the propeller, be fore Lhc r p m falls lo
the l OOO rpm region .
(b) O n most twins th e usual proced ure wh en
shuuing down an engine which has failed is
initially to close Lh c th rottle of the in operaLive
engin e. This serves to confir m which engine has
failed before commencing th e feathering
aclions. However, if th e wind milling rpm h as
reduced towards the critical region where
fea thering may not be successful, then
re-op ening the Lh roule will usuall y increase .the
rpm sligh tly and improve the probability of
being able to feather.
(c) I n Lhe even t of an engine failure, it is important
not to let the a irspeed red uce below the
sch ed uled enginc-oul climb speed . This will
help LO en sure that the propelle r con tin u es to
windmill at su fficien ll y high r p m for feath ering
to be successf ul. If optimum performance is
required it is vital to achieve and main tain Lh is
best e ngin e-ou l climb sp eed .
(d) The loss of per formance associated with a
stopped propelle r in fi ne p itch or mo re
im portantly with a windmilling propeller is
potem ially ser ious. The ad ditional d rag will
considerably red uce the single-engine climb
perfo rm ance from th at available with a fully
feath ered p ropeller. The directio nal
con trol-liability will also be reduced, th ou gh
adequate control should still be available down
to Lh e minimu m control speed (Vmca), as Vmca
is de ter mined with the p ropelle r in the
conditio n exisLin g p rior to fealhe 1·i ng action by
the pilot (i.e . nor mally with a wind milling
p ropeller). It will proba bly not be possible to
tri m th e ai rc1·aft on th e rud d er tri m a l Lh e best
rate-of-clim b speed and a consider able foot
force may have to be held to maintain heading.
However , it can not be over-emphasised th al, if
iL is necessary to gain or conser ve altitude, Lhc
best available performance is esscnlial and for
th is the besl engine-out ra te of climb m ust be
main Laincd •
Aviation Safety Digest 109 I 9
�Low level turbulence
Turbulence can be classed as second only to wire strikes in the order of hazards facing the
agricultural pilot. Although directed towards this specialised kind of flying the following article is of
value to all general aviation pilots in respect of take-offs and landings.
When looked at practically and analytically the
problem or low level turbulence is not
insurmountable. The two main causes of turbulence
at low level (up to 1000 feet AGL) are:
- Thermal movement of air
- Mechanical disturbance of an airflow
Thermal movement of air
Rising parcels of air (thermals) are caused by air
being warmed to different temperatures over
d ifferent surfaces. For example, on a sunny day, a
newly worked-up paddock in sandy country,
surrounded by fully stooled crops which cover the
ground with a thick green canopy, will have a much
higher surface temperature. The bare ground will
supply much more heat to the air than will the
surrounding crops. This hotter air will rise by
convection and an aircraft flying over the crops,
then the bare paddock, will be carried upwards by
the r ising a ir when it comes to it (Figure 1). The
upward motion will cease as the aircraft flies out of
the rising air.
Figure 1
Of course some a ir has to replace the r ising air
over the bare paddock. Cooling parcels of a ir
descend in other places and move in to replace the
rising air. Both are happening at the same time and
this raises and lowers aircraft flying through the
various parcels of rising and descending air (Figure
I). Aircraft operating in close proximity to the
ground are most obviously affected.
Moving air always has a small rotation and this
becomes concentrated as the air moves towards the
centre of the low density area. If the heating is
quick and the contrast in temperatures is hig h this
will result in a more violent rising of the heated air;
the inflowing cooler surface air will m ove in rapidly
with a twisting movement and give birth to a
vertical vortex - the 'willy-willy' (Figure 1). Aircraft
operating at low level and passing through this air
will indubitably be affected, perhaps with critical
results.
Mechanical disturbance of an airflow
Air flo wing across terrain of varying height du r ing
the day will te nd to follo w the line of the terrai n.
This brin gs abou t a n umber of effects . Firstly, Lhe
air on the upwind side of an und ulation will rise
and on the downwi nd side of an u nd ulatio n will
descend (Fi g ure 2). An aircr a ft o peratin g on the
windwa rd side will a lso r ise (updraft) and o n the
leeward side will descend (downd r aft).
Secondly, the air flo wing close to the crest of the
undulation will ha ve a highe1- relative speed and the
local effect upon an aircr aft flying fro m wind ward
to leeward will be a red uction in airspeed d ue to its
inertia and this resu lts in a loss of lift. T he reverse
is the case when fl ying from leewar d to windwa rd.
Thirdl y, the airflow o n the wind wa rd side will
tend to be streamlined, wh ereas on the leeward side
the air will tend to break away, resulting in eddies
and swirls instead of the streamli n ed flow.
T o ill ustrate the e ffect of th ese three factors,
imagine an a ircr aft flying downw ind across a ridge
in und ulating te rrain . As the aircr aft ap p roaches
the windward sid e o r the r idge th e air rises and so
does the a ircraft; the ai r accelerates towa rds the
crest resulting in loss of airspeed a nd lift; as the
aircraft passes the crest it is subject Lo downd rafts,
and eddies and swirls in the air. An aircraft
app roachi ng from the other di rection will fi nd the
eddies an d swirls first, toge ther with the downward
movement of the air; as it passes towards the crest,
there is an increase in a irspeed and lift followed by
updra ft li ft on the wind ward side - classic
mechanical tu rbule nce .
Figure 2
...... ...... ......
......
Air flo wing o ver o bstructions (trees, houses,
bridges, etc.) will ha ve ver y little str eamline flow
a nd will quickly brea k in to a turbulent flow close to
the obstruction (Fig ure 3) . O n the u pwind side
there is virtually no effect, but d own wind, the
stronger the airflo w, the more pronounced the
turbu lent flow. Wher e the obstruction is continuo us
and re lati vely uniform , i.e . a fo rest or a belt of
scr ub, the tur bulent flow will be continuous and
strongest close to the tr ees. The same factors apply
in a lesser way with airflow across the su rface of a
cro p. T urbule n t flow will 1·esult a n d its effect will
vary with the natu re of the crop. For example , vines
and cotton will generate mor e tu rb ulent flow than a
cereal crop like wheat.
Figure 3
....
10 I Aviation Safety Digest 109
Aviation Safety Digest 109 I 11
�One of the products of the eddies and swirls
res ulting from the above is the interr uption and
resumption of the normal flow. We know these
variations as g usts and they are more pronounced
as the airflow increases. An aircraft passing through
a horizontal gust from the rear suffers a loss of
airspeed and lift due to its inertia, follow ed by a
1·eturn to its previous airspeed and lift as it flies out
Figure 4
can anticipa te, at the least, rising and descending
air, or at the most, strong 'willy-willys',
so be ready.
To help yo u anticipate and be ready, use
common sense in looking for signs of turbulence,
both thermal and mechanical.
- Look ah ead o f the crop yo u are treating. Gusts
quite often show up well, particularly over cereal
cro ps. So do 'willy-willys' which ma y move
crosswind, acr oss your path.
- Loo k ahead in your procedure turn. Gusts will
s how u p on the ground particularly in the crop.
The relati ve movement of trees will show
acceleration a nd deceleration o f air movement.
Stud y the path yo ur turn will take.
- Watch for dust rising; it is always a good sign of
a relative change in air movement, both thermal
and mechanical.
of the g ust. Approaching from the fron t of th e gust
resu lts in a n increase in airspeed and lift whilst
entering, and retu r n to previous conditions when
th ro ugh (Fig ure 4). The result is a bumpy r ide. A
side gust simpl y d rifts the air cr aft vio lently
downwind with the drift ceasing just as violently
when out of the gust.
tttt
- Anticipate changes in airspeed and drift caused
by g usts and the blanking of wind movement.
This will result in the aircraft being less prone to
rise and fall in gusts. It will also enable you to
track straight when passing in and out of a
blanked area on the downwind side of ;m
obstruction.
- Watch for visible meteorological signs movement of low cloud showing wind speed and
turbulence , breakup of fog or mist suggesting an
imminent change in surface temper ature,
condensation or dissipation of cloud on u pslopes
or downslopes of hi lls which show topographical
uplift or downflow.
You cannot prevent or stop low level tu rbulence,
but through common sense and anticipation you
can make it a lot easier to live with - and live is the
operative word •
Unpredictable birds
.\.
towa rds the li ne of scru b and if" it is o n a spray run
close to the trees, this can be quite awkward . The
pilo t corrects and flies with no drift laid off
whereupon the a ircraft emerges from behind the
scrub and is su bject to immediate drift which moves
it downwind u ntil the drift is laid off again (Figure5).
One example that is similar to g usts, but belongs
in the a rea co ve red by Fig ure 3, is when an aircraft
flies crosswind in uninterrupted ai1· flow and passes
on the leeward side of a line of scrub o r trees. The
aircraft a lread y has its drift laid o ff so th at when
the crosswind suddenly ceases, th e aircraft moves
!
Figure 5
+
)
"~~~\)
~
· '.
\._,
'
..,.,
..
-.
.'
~
i"~'
..,
'
-
,...
+
,,µ
-+•~>
-!
,_
!
..
!
•
i•~'
' -'
Methods to counteract and avoid the problem
Use a combin ation of commo n sense a nd
an ticipatio n . A strong wind blowing over a patch of
trees is obviously going to ge nerate turbulence.
12 I Aviation Safety Digest 109
!
!
!
Anticipate it and be read y for iL.
An area of cotton or vines with a sealed road an d
parkin g a rea adjacent is goin g to create sharp
d iffere nces in te m peratu re close to the ground. One
A large floc k of seagulls had been seen in the
vicinity of Runway 14 at l\fackay shortly befor e
0700. The lire se r vice vehicles on runway inspection
had a ttempted to disperse the birds, but the flock
was pe rsistent and continued Lo circle and land as
the fi r e ve h icles passed.
A DC9 was due for departure at 07 10 and , by the
ti me the ai rcraft had lined up on Runway 14, the
birds h ad settled on the runway from the
in ter section sou th fo r about 200 metr es. The pilot
was advised of the hazard but he replied that the
birds would p robably move and continued the
take-off.
Rotation was at the imersection and the aircraft
was just a irbo rn e wh en the birds rose from the
ru n wa y. T h e aircraft passed through the flock,
killing m o re th an fift y seagulls. Th e onl y damage
sustained by the a ircraft was loss of a static
d ischarge spike .
·fhe passenge rs a nd crew of this aircraft were
ex tre mely lucky th at no critical engine components
weTe damaged by birdstrike. T he result could ha ve
been catastrop hic if, for example, the gulls had
been in gested in Lo the airc1·a ft engines. Consider a
parallel occurrence to a Falcon 20 out of Florida
USA:
'Before t he accident, airport em ployees had
dispersed a flock of gulls from the runway. Most of
the g ulls d eparted but about 30 returned . The
radio normally carried by the bird scarin g team was
unserv iceable. By th is time (0855 hours local time)
the aircraft had stai-ted its take-off run. Shortl y
after becoming a irborne it passed through the floc k.
Ro th engines failed and the a ircra ft crashed . The
fuselage was severely damaged, a wing separated
and all eleven occu pants were seriously injured'.
T he hazards associated with birds on or near a
runway should be obvious. Who the n has the
responsibil ity to advise of bird hazards and d eci.d e
whether or not take-off should be attempted?
Should th e towe r controller proh ibit take-off on the
grounds that a hazard ex ists, or does the onus rest
with the pilot in command? Reference to AI Ps
answers our questions: For take-off or landing ATC
will advise of the presence of birds on the runway
or strip when in numbers or of a size likely to be
hazardous. However, the decision to proceed with a
take-oil when the presence of birds has been
advised rests solely with the pilot in command.
An interesting sidelight of the DC9 incident is
that the pilot expected the birds to d isperse as the
aircraft approached. This had been h is experience
in the past. H owever, in this case the flock was large
and concentrated, and therefore the birds in the
centre may have been restricted in their escape
path, being forced to rise, rathei- than clear to the
side of the oncoming aircraft. Apparentl y tb.e o n ly
predictable thing about th e behaviour or birds is
their unp1-edictability •
Aviation Safety Digest 109 I 13
�Air safety incident reporting
the Australian system
F rom t.h e beginning of aviatio n history it was
rec~igrnsed that tho~o ugh in vestigation of aircraft
acCJC;~ents w~s e~se ntia l to promote safety and public
conhde_nc~ 111 air transpor t. The inciden t repor ting
syste ~n 1s simpl y an extension of that concept and
p1yv1.d e.s the opp? rtunity to ex p lo re a grea te r range
of ~viauo.n acn~1u ~s than those examined during
acc.•de nt mvesuga tions. In th e Australian system ,
which has been operating fo r over 30 years, the
results o btaine.d rr.om i1.westigations of all reported
occur rences a l fccun g air safe ty a re combined into a
total system. Accidents ca n be reviewed in
conjunction with incidents whi ch occurred under
similar circumstances.
Th e obje~ti ~c of air safet y investigation is to
p romote aviauon safety, not to apportion blame or
liability. T h e system aims to d etermine all the
facto rs that arc releva nt and to use them as a basis
fo r enha ncing the sa fety of avia tion in Australia.
-
Serious inci d.en t~ which in volve significant safety
as pects can be 1mt1all y rep o rted by radio o r
tele phone a nd will be p assed immedia tely thrnug h
th e syste m to a n air safety investigator. In all
Regions the re are investigators available 24 hou.-s a
d~y - seven days a we~k. ~ message passed to a n y
~ irwa_ys Operaw.m s umt will be relayed to the du ty
m ves u.g~tor . H e 111 tu rn, if necessar y, will telepho ne
the on grnator of the re port at a ny nominated
nu mber. Wh ere th e inciden t involves a complex
situ ation , the investiga tor may request th e
o rigin ato r to provide a writte n re port or
a lternativel y ar range a meeting to discuss and
cla rir)' th e circu mstances.
•
Investigation of incident reports
De partmen tal proced ures provide for rapid
moveme nt o f incide nt reporLs to Regio nal O ffices
whe re they arc examined by specia list in vestigators
who arc e m p loyed totall y o n air safety investigation
What is an incident?
work. These o ffice1·s are qui te se para te from, an d
The le.gal de fi~i ti on o f an incide n t a nd the stat uto ry have ~o responsi~i lity for, the regulator y a nd
reportm g require ments are con tained in the Air
surveilla nce fu nctions of th e Departme n t.
!'Ja~iga tic!n Regulatio ns. For prac tical purposes a n
Each incide nt report is investigated to establish
11~ c1d e nt 1s an y occurren ce in which the safety of an
th e facts and circumstan ces involved - what
a ircraft or pcrsc~ns has bee n jeopardised or which
~ ap p~ n e~ a nd wh.Y it h ap pened . T he d ep th of
the reporte r .be.hevcs ~o be hazardous. Any report
111 vesuga uo n 1·equ1red d epends upon the natu re o r
re l a te~( to a v1auon saf e ty will be inves ti ga ted to
the in cide n t. It may var y fro m sim ply ens u ring that
esta blish the fans.
the re port is sufficiently d etailed fo r codin g a nd
en try 111 to the corn p u te1·-basecl d a ta system, to the
Who reports incidents?
oth e r ex treme or a very com prehensive
Pilots, owners, operators and De partmen tal officers
investigation p rocess necessitating discussion with
a ll have obliga tions to rep ort incidents. I n p ractice,
t~ c origi.nator, obtaining reports from other persons
a n y pe rson who becomes aware of a n occurre nce
d irectl y involved , co-ord ina ting enqu iries with other
which j eo pardises aircraft safe ty, or which could
gove rn~n~nt a.u thorities, an alysing fl ight p la ns,
ha ve do ne so in combination with other
transcnbmg ai r-ground voice recordings and,
circumstan ces, is invited to utilise the incid ent
wher~ ava i!able, exa minin g fl ight data record ings.
re porting system to bring th e matter to the notice
Th e 1u vcsugator gath ers a nd conside rs all the
of the Departme n t.
relevant evidence a nd may a lso need to consult
How do you notify incidents?
ex per.ts in partic1:'1ar fie.leis. H is primary task is to
The reporting o r incide nts is th e key to the wh o le
~stablis.h all th e factors 111volved and pre pare a n
syst.e_'.11. The most conve nie nt a nd commo nl y used
1mpart1al re port on the incid en t investigation.
1~ou tica u~m mctho·d is the well known yellow '225'
T he in vestigator's report is referred to Regional
for m which h as been aroun d the ind ustry,
Departmenta l officers having responsibility fo r
d eliberately without substantial cha nges, fo r over 20 matters revealed du ring the investigatio n. 1n most
yea rs. The con ve nie nce of this form is that it
cases, and pa r ticularly in areas which in volve
simplifies compilatio n of the report. ff '225' form s
Depa rtme nta l fu nctions a nd facilities, immed iate
arc unavailable, reports may be made in an y written acti.c~n is ta ke n at th~ Regional level to rectify a ny
form, or ve rbally by telepho ne o r radio.
facility fa ul ts or revise local procedures.
Writte n reports , incl udin g the '225' for m, can be
T he broad details o f all sig nifica n t incide n ts are
lodged a t an y Airways Operatio ns unit, with o fficers telexed or telephoned to Centra l Office im mediately
ii: charge at governm e nt aerod ro mes, or posred
they become know n. Central Office investigators
direct to an y Regional Office or the De partme nt.
cor rela te the known deta ils with similar incide nts
Ve rbal re pon s may be made in fligh t (by rad io to
th at may have occurred in other Regio ns, o r search
an y ATC ?r FS _uni t) or afte r landi ng (by telepho ne com puter or other records for relevan t infor matio n.
to an y offtce r of the Depanme lll).
Close liaison is maintained betwee n Centra l Office
14 I Aviation Safety Digest 109
a nd Regio ns to ensu re that the maximum benefit is
d erived fro m the total investigation system.
Concurre ntly with any remedial action that may
be proceed ing at Regional level, each incident
report, with the in vestigator's report, is forward ed
to Centra l Office. T he reports are reviewed by
other investigators a s part of a quality control
system and , wh ere applicable, referred to function al
Division s within Central Office with
recomme ndations or suggestions as to areas
warran ting atte ntion. The action taken at Regional
level ma y th e n be introduced nationally, or perhaps
modified in the lig ht or similar occu rrences in other
Regions.
Storage of information
On ~o~pleti on of t~e review and any action arising,
the 111c1de nt rep ort 1s coded and entered in the
compute r-based data storage system.
The Australia n d ata storage system is closely
compatible with tha t used by the National
T ransp ortation Safety Board , U.S.A. This
compa tibility h as e nabled the a n n ual exchange of
computer tapes of aircraft accide n t data, giving
immediate access to information about thousands of
accidents in volving almost all types of aircraft. A
simila r exch ange a rrangement has also been
establishe d with th e Federal Republic of Germany.
Additionally, New Zealand and Papua New Guinea
fo r ward th eir accident investigation records to
Australia for inclusion in our computer system and
share in retr ieval from the total records available.
In 1976, I CAO introduced an accident/ incident
re por ting system which is also similar to the
Australian and US A systems.
Use of stored information
The most valuable contributions to safety alread y
achieved by the system are the opportunities
provided for mo nitoring the performance of
De partm en tal services and facilities, examining the
supervision standar ds exercised by operators,
reviewing the efficiency of civil/military traffic
co-ordination, gauging the standards of
mainten ance and servicing, and generating safety
awareness in personnel with operational
respo nsibilities. In the 30 years the system has been
op erating, th e collective examination or facts
revealed in incide nt investigation has led to the
origination or amendment of nearly all operational
standards and p rocedures.
Anothe r develo ping source of accident prevention
in fo r mation is available from statistical analysis of
reco rded accident/ incident data. Prior to the
availability of computers, the retr ieval and analysis
of such data was ver y time-consuming and this
imposed severe limitations on th e number and
sco pe o f" su ch studies. Computer processes have
been used in Australia since J 969 to record a wide
range of accident a nd incident data, anJ there now
exists a substantial data base , read ily accessible for
ana lytical purposes, against which trends can be
ad equa tely measured and wh ich p rovides a sound
basis for accide nt prevention stud ies.
Data stud ies have been conducted during the past
few yea rs o n a range of accident prevention subjects
and, as a na lytical experience is gained and
computer programs are further developed, more
complex studies a re being un dertaken. The
infor mation gained through these studies often
forms the basis of articles in the Aviation Safety
Digest, Airworthiness Advisory Circulars and other
Departmental publications aimed at improving
aviation safety.
'
What of the future?
For many years, worldwide accident prevention
efforts were concentrated on improving the aircraft,
its su pport facili ties and operational procedu res.
T he success of these efforts is reflected in the
improvements achieved in the technical reliability of
modern aircraft and the sophistication of the
airways operations system for handling increased
movements. It has been recognised for some time
that further significant progress in accident
prevention may be achievable only by reducing the
contribution mad e by human factors in the
circumstances leading to accidents. Isolating the
circumstances that lead to human error and
eliminating these factors, or at least minimising
th eir effect, may p roduce the same improved safety
level as already ach ieved in the technical and
procedural areas.
Accidents rarely escape notice and the
investigation of over 250 each year reveals the
human factor contribution. On th e other hand,
most incidents, which are rich in h uman factors,
become known only when reported by the
personnel directly concerned. O ur accident statistics
show a human factor involvement of over 70 per
cent but correspond ing incident statistics show only
15 per cent. Obviously there are many human
factor incidents known on ly to the pilots a nd other
personnel who experienced them.
I nvestigation into human factor involvement in
incidents confronts a fundamental human
characteristic - live human beings, our vital
witnesses, arc reluctant to reveal occurrences which
reflect u pon their ability and knowledge. Some of
this reluctance a r ises from misunderstanding the
purpose of incident reports. T hey are not black
marks against a person's record - the y never have
been and never will be. Another reason sometim es
given as to why in cidents are not reported is that
people do not have faith in the system and are
concerned about possible punitive action. To dispel
this concern we refer readers to the immunity
provisions restated by the Secretary in Aviation
Scffety DigPst 100.
The output of the incident reporting system is
directly proportional to the input. If you wish to
obtain the maximum ben efit from the system it is
necessary for you to report an y occurrence which
endangers the safety of an aircraft and its
occupants. Air safety incident reports form a vital
com ponent of our aviation safety monitoring system
and by making full use of the incident reporting
procedure you will be playing an important role in
the improvement of safety in the air •
Aviation Safety Digest 109 I 15
�Selected incidents
The following contribution was received f rom an unknown pilot in NSW. Anonymous letters are not
usually printed in the Aviation Safety Digest because their contents cannot be checked for
authenticity or accuracy. However, this example is a useful illustration of the importance of the
incident reporting system. If the author had not taken anonymous pen to paper, the safety messages
inherent in his experience would have been lost to fellow aviators.
DEPARTMENT OF TRANSPORT
AIR SAFETY INCIDENT REPORT
Folio No.................................................. .
Station .......................................................
No.............................................................. .
Reg. Off. No .............................................
Central Off. No ........................................ .
Normally this repon should be mailed to the Director of the Region in which the incident occurred. If more convenient it may be
lodged with the OIC of any Air Traffic Control or Flight Service Unit.
LOCATION OR ROUTE SECTION ....... '.r.i.~(lfl.~....-:'.'....P..fl.r.'.'1.;i.l'.L .. Date.................!. ................... Local Time .. '. .. .
?
.......
AIRCRAFT: Type and Marking .... <:;~.~.~~A
....:1.7.?..... ........?............... PILOT : Name and Initials.............................. .? ...............
?............................................ FLIGHT CATEGORY: (underline) VFR
OWNER/OPERATOR.................................................
?
IFR
TYPE OF OPERATION (underline applicable type):
?
Regular Public Transpon
Chaner
Agriculture
Aerial Work
Private
Aircraft Test Flight
Training Dual
Training Solo
FLIGHT: Last depanure point ............ 'l'.~.~9-9.-~
First point of intended landing ...... P.~T\'/:~JL .. Flt. No.. .....::: ..... .
When this repon is submitted by a Depanmental officer, enter Fault Repon No. (if applicable) .................. ::'.'..................... .
DESCRIBE INCIDENT AND RELEVANT CIRCUMSTANCES, with comment and suggestions:
........................
· [was 011 a safa ri trip around Au stralia in a Ce~sna
17':!. \\'hen I stopped at Tindal for a couple or da\ s.
I filled the tanks of m~ plane and. after unloading.
I tied it dmrn in the parkin g area and departed for
a ,·c1·~ e njO\ able ,·is it to the famous Katherine
Gorge.
'Tm> da ~s later. I s ubmitted a !lig h t plan for a
trip to the Alligator RiHT an'a so that llT could see
this interesting <·01111try from the air and then.
11·ithout landing. continue on to Dani in.
·Ha,·ing loaclccl the plane. I did a qui ck pre-fl ig ht
dail~· inspeuio11 and to speed thin gs a lo ng I had
one of Ill\ passengers check the fuel tanks 1rhid1 I
k11e11· 11Tn' full lic('a use I had filled th e m mYselL I le
informed me that OJH' tank 11-;1s full to the t;>p and
the other one \\'<IS "do11 n a little bit"".
·Durin g the pre-take-off eh('( k l found that one
tank gauge sholl'ed less than half full. but a~ I had
filled both tanks nl\'sc lf and fro m 11·hat my
passenger had told . me afte1 his 1is11al <ht:t k. I 11as
inclined to susp<'<1 the accuracy of the ga uge. In
addition. another aircraft 1ras 11aiti11g to take off
behind me so 1 dismissed the matter and took oil.
'\\'e flc11 o\'cr the Katherine C:orgc th en
continued tmrnrd s the :\lligator RiHT area. :\car
Cooinda I noticed that both fuel gauges 11c1-e
shcl\\'ing less than I expected so I irnmcdiatcly
headed for Darn·in a nd . as I approached the
airport, I could sec that the fuel c011tcnts 11T1T
dangerously loll'.
16 I Aviation Safety Digest 109
·After landing. I chc<i.cd the tanks to find tha1 I
had f'ar less than Ill\ required 4 :) minutes of 1-csn1T
fu <'I.
·1 a m no11 of the opinion that m ~ trouble started
11·hen I parked the plane on unel't'IL sloping
grou nd 11·ith one 11 ing lm1 a nd the fuel co< k left in
th e "both "' tank-- position . Fuel drained from one
ta nk to the other and out the 01·erfl o11· during the
1110 d a~ period that I 11as at Katherine Corge. The
lost fuel had no doubt ~naked into the cir\' earth or
had e1·a porated and 11 as noL noticed 11·hc11 1
returned to the plane . '.\[~ IH'Xl mistake 11<1s to haH·
a passenge1· ma ke the 1·is ual check of the tanks. I lad
I done so ill\ !>cl f I \\ otild h an· realised that llHlH'
than half th~· mnH· nt~ of one tank had drained
,111a\. :\ fr11· inches of air space tom~ passenger
sim pl~ meant that the rue! 11·as "dmrn a little hit " in
the tank.
' \h next mistake 1rns in suspecting the an urac~
of Ill\ fuel ga uge 11 hen ma king my pre-take-off
che< k and. in add ition . I sho uld not ha\'C been
"hurried"' by the knmdedgc that someone else 11as
11aiting behind rnc to take off.
'The f1ight ended 11 ithout mishap . but had I
<ontinucd to fl~ mTr the Alligator Rin·r area as
planned. it might ha\T been a different stm ~ in the
f)i~nt' •
While o n a private VFR flig ht to a n aerodrome
inside a co nLrol zone, a Piper Aztec was 1·eported to
be in co ntro lled airspace without a n airways
clearance. When its positio n could not be positi vely
established, a n Uncertainty SAR phase was
declared. The p ilo l had advised Flig h t Service that
the aircraft was at l 0 OOO feel a bove eig h t oktas of'
clo ud a nd estimated overhead th e destination
aerodrome five m inu tes late r. H owever, the position
and estimated time of arrival given by the pilot
were inaccurate and, because th er e were very few
breaks in Lhe cloud , it was almost an hour befo re
the a ircraft was established below cloud in a known
posi~ .)n . Eig ht o ther aircraft had th eir operations
delayed or restricted for periods of up to 50
m inutes.
The pilot, who held a pri vate licence and a Class
4 instrument rating, had a to ta l fl ying experie nce or
about 700 ho urs. Arriving al an un con trolled
aerodro m e th e previous eveni ng, he fo und the re
was no overnig ht accommodatio n availa ble in th e
nearby town so he a nd his passenger were forced to
spend the n ig ht in the aircraft. Next morning th ey
did not have any breakfast an d there was only water
lo drink .
In te nd ing LO leave earl y, th e pilo t tele phoned
Flig ht Service a t 0618 hours and lodged a flig ht
plan . He ind icated he would be fl ying below 5000
feel a nd th at he planned to emer controlled
airspace al the control zo ne boundary. T he briefing
office1· ad vised the pilo t of th e wind d irection and
sp eed al 3000 and 5000 feet an d was about lo give
him the wind at 7000 feet wh en the pilot
interrupted a nd said he had sufficie nt informatio n .
T he briefing officer the n gave the p ilot the terminal
forecast fo r the destina ti on aerod rome , which
predicted visibility gr eater than 10 kilometres, ra in ,
two oktas of stratus clo ud al 1.1 00 feet a nd five
oktas of strata-cumulus clo ud at 3500 feet. Th e
section o f th e area forecast which th e pilot said he
did nol require p 1·edicted that e n route there woul d
be scatte red and broken cloud in layers from I OOO
to 14 OOO feet with some raiu showers.
Al 0652 hours, the pilot gave a d eparture report.
Six minutes la ter he called again and ad vised he was
climbing Lo l 0 OOO f eet. Th e cloud beneath the
ai rcraft i11creased until , a l 0745 h o u rs, the pilot
reported that the ai r craft was above eig ht oklas and
enquired if there was still clear sky over the
destinatio n aerodrome. Th e pilot was given the
most recenl meteorological r eport for his
desti natio n , which included o ne o kla of cloud a l
700 feet a nd five o ktas at I 100 feet and this was
upgrad ed a rew minutes later to six o ktas at 2500
feet with lower patches. Shortly a fte rwards, in
res po nse to another query by the pilot, Flight
Service ad vised that south o r the destination
ae rodrom e there were seVen oktas of cloud from
7000 to 10 OOO fee t and that an aircraft 75 km
south h ad reported eig ht oktas clo ud cover .
The pilot reported that the cloud behind him had
risen to such a height that h e could not now r eturn
to the aerodrom e from which h e had departed.
Add ing that he h ad ad equate fuel reserves, h e then
asked if th e re were any gaps in the cloud throug h
which he could descend. He said the a irc raft would
be over the towe r in a bout five minutes and that he
tho ught h e had received a clearance to overfl y the
ai rport. Knowing this was not th e case, the Flight
Service officer no tified AT C of th e aircraft's
reported p osition and at 0809 h ours the aircraft was
transferred to the tower frequ ency.
The aircraft was about 75 km further away from
the aerodrome than the p ilot h ad reported and,
ailhough attempts wer e made to es tablish its
p ositio n using ADF bearin gs and aircr aft h eadings,
lack of DME eq uipme nt made it difficult Lo locate
the a ircraft acc urately. Because of this, ATC was
forced to r estri ct the operations o f other a ircr aft in
the area.
The fi rst time th e pilot made an attem pt to
descend th rough a ho le in the cloud he was
unsuccessful and it was not until 0845 hours that
the aircraft was able to descend below cloud and
remain in VMC. At 0906 hours the positi on o f the
Aztec was positive ly esta blish ed 35 km from the
aerodrom e and th e aircraft eventually la nded 12
minutes la ter.
Although there was no urgent r eason for the pilo t
get to his destination , it is unde rsta nda ble that
after spending the night in the aircraft, a nd with
breakfast probably unobtainable for som e two
hours, he sh o uld wa nt lo reach th e destination
aerodrome, o nly one hour and 45 minutes fl ying
time away, as soon as possible.
Lack of proper rest and breakfast, the time of
clay and the desire to gel goi n g early seem to have
affected the pilot's atLitude to th e flig ht briefing. Al
no t.ime during the previou s da y and night, o r
be fore this take-off, had the pilot or his passen ger
seen any significant cloud. T h e pilot showed scant
interest in the wea Lher briefing a nd it wou ld appear
that, because there h ad been li ttle or no cloud th e
previous day or night, he did not expect to
encounter such heavy cloud this d ay. If he had
received th e full a r ea forecast he might have
considered delaying the flig h t or provid ing for a
diversion; however , in consideratio n of his
subsequent actio ns, th ere must be some d o ubt about
this.
The aircraft enco untered low cloud only six
min u tes after d eparture. I t seems the pilot accepted
this without question and m ade no effort lo obtain
to
Aviation Safety Digest 109 I 17
�any mo re- meteorological information until h e was
almost half-way to his destination. He displayed a
poor knowledge of weather situations and
apparently lacked the ability to properly interpret
the information passed to him e n route by Flight
Service. He delayed making any operational
decisions until it was too late to return to the
aerodrome of departure and pinned his h opes on
the chance that, n ear his d estination, there would
be breaks in the cloud through which the aircraft
could d escend. But such hopes were ill-founded
and the subsequent chain of events was virtually a
foregone conclusion. Fortunately, the aircraft was
finally able to descend through the cloud before a
catastrophic conclusion was reached.
Over an hour elapsed from the time the pilot
advised he would be overhead the d estination
aerodrome in five minutes, to the time the aircraft
finally landed. It was inevitable that such a lo ng
delay at a controlled aerodrome would disrupt
oth er traffic and , as it happened , the depa rtrn-e of
an airline jet was delayed 50 minutes, five cha rter
aircraft we re delayed on the ground , another light
aircraft was held outside the control zone and the
operation of a nother was restricted in respect of
levels.
The extent to which a night of discomfo rt,
inadequate rest, and lack of food may have affected
the pilot's prep aration for the fligh t and his
subsequent p erformance must remain a matter of
conjecture; ti)e fact re mains that h e did not exercise
a reasonable level of judgemen t a nd airmanship,
r esulting in not only inconvenience to other
airspace users but in the ex posure of both himself
a nd his passenger to a potentially d isastrous
situatio n•
By their very nature, aircraft incident fi les can give
a negative slant to aircraft operations. In variably
they deal with what went wrong - technical fa ults,
human errors, syste m deficiencies, etcetera. This
incide nt is no exception, but the way the pilot
applied his knowledge and common sense lo h andle
an eq uipme nt failure shows a positive aspect that is
most gratifying.
The pilot was on a private flight in a Piper
C herokee inbo und to Da rwin from the north east.
Initially he was working Dar win on HF but when
requested to call on VHF, he could not establish
contact. Some swift troubleshooting revealed that
the fuse for the VH F radio had blown. The pilot
replaced the fuse a nd atte mpted radio contact, but
once again the attem pts were unsuccessful. Shortly
after wa rds he noticed acrid fumes in the cockpit.
T he VHF radio was switched off and the fumes
disappeared. However, V HF was n ol the only
communication problem. To complicate matters the
pilot fou nd the HF rece ption was very poor and
contact with Darwin h ad been lost.
As clearance into the Darwin CTR had not been
obtained, the pilot elected to remain OCT A a nd
divert to an ALA near Darwin. He broadcast these
inte ntions ' in the blind' a nd ad vised that he was
18 I Aviation Safety Digest 109
listening out on the Darwin NDB. T hrough the
ATIS facility, ATC was able to pass an airways
clearance to the aircraft to track to Darwin. The
pilot followed the instructions and arrived in the
circuit area some two minutes earlier than he had
previously advised. He kept a lookout for a 'steady
green' from tower and asked his passengers to do
the same, however, when no green lig h t was
observed and after assessing that no conflict existed
the pilot carried out an orbit. This time, the
clearance to land was sigh ted .
During the incident the private licen sed pilot
acted in a very professional manner. Firstly, he
reacted correctly when a fault occur red within the
aircraft radio installation. Secondly, although HF
contact was lost, he neverth eless transmitted his
intention. Thirdly, he was aware that ATIS could
be used to broadcast ATC in structions.
Communications failure procedures are laid down
in the AIP En Route Supplement, Em ergency
Procedures Section. By reference to the correct
procedure, this pilot was able lo safel y complete his
flight e ven though communication had been
seriously hampered•
A letter received from an ira te citizen provides a
n ovel twist to an old problem. The letter reads :
'Dear Sir,
The package I have forwarded to you contains a
fuel tan k cap. I was standing in my back garden last
Satu rday morning a nd at a pproximately 11 15 local
time an aircraft passed overhead a nd this cap
la nded a sh ort distance from me.
I a m sure you will agree with me that I was very
lucky not to be injured, maybe fatall y, or have part
of my house da maged. I did not take any no tice of
the a ircraft as it passed over, so I cannot give you a
d escription of it. Aircraft p ass over this area
freque ntl y.
I r equest that you look into this matter a nd
e nsure that it is brough t to the notice of the people
responsible and th at a tigh ter control is maintained
on som e of th ese a ircraft.'
In vestigation of the incident revealed that the
aircraft, a Cessna 185, had been refuelled a t th e
nearby aerodrome. T h e pilot admitted that he had
ex perienced difficulty in replacing one tank cap. It
was a little aw kward as he was on a ladder with the
fuel hose in one h and and h e cou ld not use both
hands on the cap. He left the cap loose, intending
to replace it after h e h ad finished refuelling the
oth er tank. Inevitably he forgot to do so.
The tank cap managed to stay in place d uring
take-off a nd for the short time till the aircraft
p assed over the house, about two kilometres from
the aerodrome. The pilot completed tl1e plan ned 15
minute flight and , after landing, establish ed that
about 70 litres of fu el had been lost from the op en
ta nk.
Apart from th e loss of th at precious and scarce
liquid , Avgas, the pilot also faced possible litigation
a nd p ay ment of damages if the tank ca p h ad
injured a p erson o r ca used damage to property.
Need we say more?
Pilot contribution
With the recent introduction of the new flight
planning requirements above 5000 feel and over
120 nau tical miles, I would like to commen t on
night planning outside controlled airspace.
Firstly, we know the obvious reasons for
submiuing flight plans to the Airways Operations
organisatio n: SAR requirements, traffic separation,
Operational Control and so on . H owever, apart
from that, I be lieve a properly prepared plan is an
obvious advan tage to the pilot.
As we all know there is no requirement lo lodge a
flig ht pla n for a pr ivate VFR flight BOSO OCTA,
with the destinatio n less than l 20 nautical miles.
But before jumpin g into our aeroplane, let us
a nswer a few questions:
Have I studied the map thoroughly?
I s th ere any cha nce of diversion from m y track?
Wh at if the weath er forecast tu rns out to be
wrong a n d for th e worse?
T h ere's 180 minutes of fuel in the tanks. ls that
really enough ?
B r iefing told me o r an active LJR crossing m y
trac k. What's my plan of action if I have to
descend to 500 feet AG L for any reason? And
the list can go on.
There is on e way to ensure all these questions a re
answered. Complete a flight plan , even if you do
not lodge it.
Wh y bother? Well a t one glance dming the flight
you r tracks, headings and d istances arc readil y
available. And updating a nd revising the plan in the
a ir can o nly be an ace up your sleeve if things get a
little tight.
I a m a rath er new commercial pilot with about
630 hours and li ke the rest of yo u h ave been taugh t
Lo be prepar ed for the un ex pected ever since m y
log boo k read 'zilch'. I am not saying that flight
p lanning is the be-all and end-all of being prepared
- th e pilot-in-com mand is responsible for that. I
a m just suggesting tha t a fl ight plan can make
pleasure out o r worry. Here is an example:
Last year I cond ucted a private VFR Oight from
He ndigo to Bacchus Marsh, a distance of just over
60 nautical miles. I knew the coun try quite well. I
rang Flight Ser vice for the weather and was given
DURSTIN by Russ Day (courtesy of Flig ht
C.1-lECKING
n-JE NOTAMSJ
DURSTIN .
'broken strato-cu, base 4500 with winds averagi ng
light and variable'. Following the briefing I ch ecked
the maps and fuel were on board , then d eparted.
Shortly after reaching m y cruise altitude of 3000
feet I saw isolated r ain sh owers and the cloud base
at abou t 2500 feet in front of me. ll was still VFR
below this cloud as I descended. After about I 0
minutes, further descent was req uired to 500 feet
AG L (I had not d one th at for a long time) to
remain VFR and I had to d ivert to avoid a rain
shower.
' Is tha t the town l t1ew over once before at 3000
feet? Sure looks different down here ! Whal was m y
planned track? I wrote it on a scrap of paper h ere
somewhere. Oh yes, 150 degrees. I diverted left
about 60 d egrees, so my DG's 099 d egrees. For how
long? Three minutes I think. Okay, I'll turn on to
219 degrees for three minu tes .. . good , I should be
on track. Or am I ? I thought that road should be in
sight now. There's another town. Looks like . . .
nope, it isn't. I know th at hill next to it. So I'm l 0
miles port of track! Feels like a sou th easterly wind
at about 30 knots. Sure isn't easy navigating at 500
feet!
'What's m y heading? 159 d egrees. No, it shouldn't
be. Make allowance for drift. Wait a minute. I know
my position, so I'll make a one-in-60 correction.
H ow can I? I haven't held a constant head ing! What
is m y heading? 159 degrees. No, it isn't. H eck,
another shower!'
l eventua ll y 'track-crawled' home and the weather
improved along the way. But on arri val at Bacchus
I felt quite dissatisfied with regard to my
navi~at~om~l- condu~t, needless to say, even thou gh I
w_as 111 tam1har ternt?ry. The ad vantage of havi ng a
flight plan with headmgs, tracks etc., plus a continua l
update of the same is exceedingly obvious.
I know· that completing a flight plan can
sometimes be a nuisance. But for abou t half an
hou r of paperwork, it could be the most priceless
piece of p aper in the cockpit whe n things d o n ot
tu rn out as expected.
. Remember that most of us fl y because we enjoy
it. Let us keep it enjoyable, irrespective of whether
we are private or commercial pilots •
Crew magazine Fall 1979)
Wi4Y? SAME OLD
STUFF -TI-l lNGS
DON'T CHAN&E...
THAT MOGH/
TI-I EN WHAT ABOUT
TH£ RECENT NOTN"\ ABDUT
A MALLARt>-EATINGr SHARK
IN T/-lE NEX'T
LA KE. OVER.?.'
Aviation Safety Digest 109 / 19
�Corrosion prevention for piston
engines
Engines in aircraft that are flown only occasionally may not achieve normal service life because of
internal corrosion. This article gives guidelines on suitable procedures to prevent internal corrosion
of inactive engines. As there are slight differences in the inhibiting methods recommended by
different engine manufacturers, the method specified in the relevant engine maintenance manual
should be followed.
area. I nhibiting techniques of this nature need to be
pe rformed by an ap p roved maintenance
organisation in accordance with carefully controlled
p rocedures, and broadly involve the follo wing steps:
- Draining the nor mal engine oil and replacing
with a specially formulated preservative oil
mixture
- Operating the engine for a short time
- Dra in ing the preservaLive o il mixture
- Spraying the interior of each cylinder with
preser vative
- I nstalli ng dessicant bags and sealing all openings
- I nstalling cylinder dehydrator plugs in p lace of
the normal spark plugs if the a ircraft is to be ·
stored in a hum id region or near the coast.
- Tagging the propeller 'Engine inhibited - do
not turn propeller' and attaching red cloth
streamers to each dessicant bag to ensure they
are not overlooked when the engine is eventually
made ready for flight.
Preparation of the ai rcraft for its 1·eturn to service
will in volve the following steps:
- Removal of dessicant bags, seals, dehydrator
plugs, e tc.
,
- Replacement of spark plugs and any accessories
which may have been removed during storage
- Draining of any accumulate d preservative oil and
refilling of the e ngine with normal oil
- A thorough cleaning of the aircraft, followed by
a pre-flig ht, then a normal start-up and test
flight.
I f you ensure that the above procedures are
complied with you could save a lot of maintenance
costs and prevent an undesirable situation arising in
£light due to reduced engine power resulting from
corrosion•
Unfamiliar navigation equipment
A visit to any secondary aerodrome arou nd
Austra lia's ca pital cities will revea l large numbers or
id le aircraft in the parki ng areas. T he grass is often
cu t up to the aircraft b ut not under the wings or
fuselage; its length being ind icative of the time the
aircra ft has occu p ied that space .
T here are many aircraft awaiting sale in the
h a nds of brokerage com panies tha t have no
operational or engineering organisation supporLing
their sales ciepa rtments. In addi tion , there are man y
owners and operators not using their aircraft as
freque n tly as in the past because of increasing
operating costs and s hortage of fue l. Under th ese
circumstances an a ircraft with a main tenance release
valid for 12 months o r 100 hours may on ly fl y for a
few hours du ri ng that period.
T he Airworthi ness Branch o f the Department of
Transport has noticed that a number or defects are
beginning to appear which are directl y auribULa ble
to a lack of e ngine operation . These defects show
up as 'blow by' and loss of compression, resulting in
the need to replace cylinders beca use of internal
cor rosion. Even tho ugh the aircraft has been
properl y maintai ned a nd certilied in the past, the
proble ms arise because the engine has remained
idle for excessive periods without the co rrect
precautions.
Unlike the military situation, there a1·e no
ma ndatory civilian requi rements to inhibit or run
e ngines wh ich a re likely to be out of service for a
mon th o r more. Consequentl y, a pros pective buyer,
o r a n owner whose a ircraft has been flown
infreq uentl y, could be faced with a loss of engine
power and costly repa ir bills because of internal
corrosion of the engine.
The type of protection necessary for the
20 I Aviation Safety Digest 109
prevention of internal corrosion depends on the
le ngth of time the engine is expected to be out of
ser vice, on climatic cond itio ns, whethe 1· the e ngine
is installed in an aircraft a11<l whether or not the
a ircraft is stored in a hangar.
O n flyable a ircraft and u nder favourable
atmos pher ic cond itions, an engine which is operated
on ly at irregula r intervals can he adequately
protected from co rrosion for a period of' up to one
month by periodically using the prope lle r to turn
the e ngine through fi ve or six revolutions. T h is will
disperse beads of moisture that may have
accu mulated and will spread the lubricatin g oil
arou nd th e cylincier walls. Unless the a ircra ft is
flown , re peat this p roced ure every five da)'S or so.
After one month , the aircra ft should be flown, or at
least ground run for 30 minutes, ma intaining the
o il te mperature wi thin the norma l operating limits.
This procedure will eva pora te an y moisture which
ma y be present in the lubricating oil. The r un
should be carried out at low engine speed
(1200-1500 RPM) while exercising the pro pe ller
contro ls to ens ure complete o il circu lation . Avoid
excessive ground r unn ing a nd obser ve th e
maximum cyli nder head tem peratu re limits.
Ground runnin g the engine f'o1· brief pe riods of
time is not a substitute fo r turn ing the engine over
by hand. I n fact the practice o f brief running will
tend to aggra vate rat he r th an minimise cor rosio n
format ion. T his is because a brief ground run does
not evaporate the moisture from the oi l and
encourages furthe r cond ensation to take place.
If it is kn own that an a ircraft is to rema in inactive
for 30 clays o r more, more comprehensive
procedu res s hould be carried out, especially if the
aircraft is located near salt water or in a humid
Most pilots, at some stage or other, have
expe rienced the problems of fly ing unfamiliar
aircrnl'l for the fi rst time : cockpit layouts, the
operatio n of ancillary controls and the location and
function or engine a nd electrical switches can all
var y significantly, even between aircraft of the same
basic model range.
But perhaps the area with the greatest potential
fo r e rror is in the operation of increasingly
so phis ticated rad io and navigation systems. In many
cases, this eq uipment requires specialist operation al
know ledge which can not be gained simply on a tr ial
a nd error bas is. The re are numerous instances on
record of pilots mismanaging radio and navigation
equ ipme n t a nd ye t another example of this
occurred recently when a pilot decided to check the
in-llight functioning of a new navigation system
i11stalled in a Pipe r Cheyenne. So far as is known,
the aircraft was the first to be brought into
Austra lia wiLh this equipment fitted.
The pilot, who held a Senior Commercial licence
and a Class 1 instrument ra ting, had consid erable
aeronautical experie nce but had received no formal
training in the use of th is system. Not havin g the
bene fit of any other pilot's advice in operating the
system, he had studied the man u facturer's
ha ndbook in an effort to acquire the necessary
know ledge.
T he route the pilot had planned fo r his
familiarisation exercise was from Bankstown lo
Katoomba, Bindook and back to Bankstown. H e
depa rted Rankstown on a n IFR clearance, cli mbing
to fli ght level 200 and trackin g direct to Katoomba,
his first wa)' point.
T en minutes after the Cheyenne de parted, a
Boeing 747 on a scheduled service to Singapore
departed from Syd ney Airport with a clearance to
climb to fli ght level 330 and track via the 275 radia l
of the Sydney VOR. T o provide separation from
the C heyenne, the 747 was radar vectored about
live miles north of the Sydney-Katoomba track.
Shortly after the 747 reported climbing through
flight level 165, the Cheyenne reached Katoomba.
Although the pilot could not subsequently recall his
precise actions at this point he intended that the
system, which had the Bindook VOR programmed
as the next way point, would be selected under
auto-pilot control to bank the aircraft into a left
turn over Katoomba to intercept the track to
Bindook. Instead the aircraft ba nked to the righ t
and by the time the pilot had disengaged the
a uto-pilot and resumed manual control, the aircraft
had turned th rough about 90 degrees and was
heading into the path of the approaching Boeing
747. Unaware at first of the potential conlliction,
the pilot contin ued the r ight turn through 270
degrees to take up the heading for Bindook and,
during the latter part or the turn, he saw the 747
below him.
Obviously, there was room for im provement in
the man ne 1· in which th is familiarisation exercise
was cond ucted. The possibility of something
unexpected happening in such circumstances must
always be kept in mind. In this case it was fortuitous
that vertical separation was maintained from the
747.
The airsp ace in the immediate vicinity of a capital
city primary airport is not the place for
experime ntation. Pilots wishing to fam iliarise
themselves with new or sophisticated equipment
should observe the following basic precautions:
- Climb to a safe height
- Remain in VMC
- Stay well clear of controlled airspace while
becoming fa miliar with the various modes of
operation.
As an ad ded precaution, pilots shou ld carry a map
showing the aircraft's track via the planned way
points and which clearly shows the direction of each
turn•
Aviation Safety Digest 109 I 21
�Servicing older helicopters
A Be ll 47 helicopter was engaged in cattle
mustering operations on a station in the Northern
Territory. Al about 1300 h ours local time the pilot
was h erding cattle into wind towa rds a ya rd. H e
n oticed that three bulls, standing unde r some
bushes near a billabong, were not movin g and the
normal driving p asses at 35- 40 knots were
unsuccessful in shifting these beasts.
In an attempt to move th em the pilot made a
precision approach towa rds them , as if for a spol
landing, but keepin g the speed at about 30 kn ots,
which was a bove the translational lift sp eed. Th e
aim of this technique was to ensure that th e animals
could see the aircraft for an extended period of
time .
T he he lico pter was still descending when the bulls
ran out from the bushes and the pilot applied
power and started climbing out. Whe n the machine
was about 50 feet above the bushes, the pilot
sudden ly h eard a ver y loud 'crack' and the
helicopter began rotating to the right. The pilot
rapidly closed the throttle a nd lowered th e collective
pitch to stop the rotation but the a ircraft turned 2.5
or 3.5 revolutions be fore this h appe ned.
When the rotation stopped the helicopter was
about 65 feet above the ground, facing down wind ,
with no groundspeed . I t began descending 'like a
rock' a nd as it neared the surface the pilot pulled
up on the collective pitch Lo stop the descent. T h e
machine la nded in som e light timber a nd slid into
the billa bong. T he uninjured pilot was able to
22 I Aviation Safety Digest 109
evacuate from the aircraft through the r ight ha nd
cabin door.
Specialist examinatio n of the wrecka ge revealed
that one tail rotor blade had separated d u e to a
fatig ue failure of th e blade g rip. The fatigue
process h ad been accelerated by failu re of the tail
rotor thrust bearing which had been inadequately
lubr icated an d was contamina ted by dust and gri t.
An other Bell 47 h elicopter was operating from
Darwin on a flight to ch eck water level recorde rs
and automatic rain gau ges a t various locations in
Arnhe m Land. O n board were the pilot and a
hydrographer. The tota l ope ration was to take four
days a nd o n the first day 11 stops were planned.
After de parting Darwin at about 0800 hours local
time th e helicopter successfully completed six of th e
stops, including a refuelling a l the fo urth location.
It la nded at the seventh location at 1237 hours and ,
about 15 minutes la ter, after the hyd rographer had
completed his checks, the p ilot restarted the e n gin e.
The run-up and initial lake-off were normal but
wh en the a ircraft was abo ut 25 feet above th e
treetops it suddenl y yawed to th e left. T h e pilot
applied right rudd er but the yaw continued to
develop a nd th e pilot was u n able Lo con trol it.
Believing that the helicopter had suffered a tail
rotor strike, the pilot red uced the collective pitch
a nd atte mpted to steer the airCl'al"t to a fo rced
la nding a rea using on ly th e cyclic pitch control. The
helicopter struck trees at a very low fo r ward speed
and crashed h eavily to the ground . It was severely
damaged but neith er occupant was inj u red . The
pilot reported the accident to Darwin by HF radio
and some hours later the two men were rescued by
another helicopter.
Examination of the wreckage during th e acciden t
investigation r evealed th at the left hand control
cable to the tail rotor had broken. I t was concluded
that the cable had failed because of excessive wear
at a position where it passed beneath a pulley. The
multi-strand cable was heavily impregnated with a
mixture of oil and dust which had accelerated the
wea r.
Excessive cable wear at this location was a known
p roblem and should have been detected d uring
regular maintenance.
The vario us models of Bell 4 7 helicopters have
been with us for around 30 years, and have an
excellent reputation for reliability a nd safe
op eration. This reputation has n ot just happened,
but is due, to a large exten t, to the cau tious attitude
of the earlier helicopter operators, and the
thorou gh maintenance given to the helicopters by
field engineers and overh a ul shop personnel.
The Bell 4 7 is a first generation helicopter and,
togethe r with others of its er a, features relatively
complicated control and drive systems, many
sections of which are exposed to th e elements.
Large numbers of unprotected bearings and
bushings are u sed and these requ ire an almost
constant supply of clean lu bricant.
Maintenance engineers, trained on these first
generation h elicopters in the 1950s and 60s,
accepted this need for constant attention as normal
a nd, a lmost without exception, the helicopters in
Australia were carefully and conscientiously
maintained. It could be said that the degree of
mainten ance given to helicopters such as the Bell 4 7
and Hugh es 300 was directly p roportional to the
amount of grease they would fling at any given
engine start.
With the passage of time, man y of the engineers
experienced in the ways of the Bell 4 7 have moved
on and their places h ave been taken by others who,
althou gh competent with the more modern
helicopters, may not fully a ppreciate the needs of
the older machines.
Most of the Bell 47s have now moved from the
major helicopter ch arter companies to smaller
operators and pastoral grou ps who, in many cases,
do not realise the maintenance back-up that a '47'
needs. This, unfortunately, is being reflected in our
acciden t files with a definite increase in accidents
which are directly or indirectly attributable to faulty
maintenan ce.
A helicopter is n ot just a fixed -wing aircraft with
its propeller p ointing upwards. It is a lightweight,
performance machin e, with many finely engineered
components operating continually at high tension
and torsion loads, and exposed to an environment
of heat, dust and water. The whole airframe is
con tinually subjected to a multi tude of vibrations,
some of large magnitude, generated by the main
and tail rotor drive syste ms and the engine.
When one considers that most helicopter
components are either primary load-carrying
members withou t any fail-safe facility, or form parts
of a primary control system on an aircr aft that is
inherently unstable, and that the loss of an y
rotating component of reasonable mass will produce
out of balance forces more than adequate to
instantly destroy the machine, some appreciation
may be gained of th e need to keep a helicop ter
maintained in top condition.
Good maintenance is not ch eap, as the larger
helicopter operators know only too well, bu t there
can be n o compromise. La rge operator or small,
without this philosophy the continuing
airworthin ess of your helicopter cannot be
assured •
Polarised instrument glass
A radio tech nician was occupying the right hand
seat of a Partenavia P68B to check the oper ation of
a Bendix 2000 navigation unit. The original unit
was undergoing repair and a replacement unit on
loan was installed in the aircraft. During the fligh t
test he leaned across the cockpit to check th e
frequency selection s and they appeared to 'drop
out'.
He later experimented with the origin al uni t and
obtained the same resu lts. All frequenc y indications,
the ILS/ VOR presentation and the RMI appeared
to go blank when h e tilted his head . I t transpired
that he was wea ring a polarised shield over his
normal spectacles a nd when he tilted his head about
15 degrees, the planes of p olarisation of the
spectacle shield and the polarised instrumen t glass
became sufficiently out of alignment that light was
not transmitted.
I t has not been possible to establish how man y
different aircraft instruments and cockpit displays
are fitted with polarised glass. A check with the
Bendix des ign engineers revealed that the polarised
glass was fitted 'to improve display readability in
conditions of h igh ambient light'. In consideration
of the advantages to be obtained from the use of
polarised in strument glass and the wearing of
polarised sunglasses it is unlikely that these practices
will be discontinued because of incidents such as
this.
We recommend that if you do wear polarised
sunglasses, check out the possible effect on an y
airc raft indication before tahe-off so that you will not
be caught out by this phenomenon at a critical
phase of your flight •
Aviation Safety Digest 109 I 23
�Some thoughts from a Met. man
A recent case of fluctuating fuel flow, low cylinder head temperature an~ rough runnin~ made it
necessary for the pilot of a light twin to stop one engine and return to his departure point. ,
A Meteorological briefing officer presents some suggestions to improve the service available to
pilots.
As general a viation grows in Australia,
Meteorological briefing officers are coming under
more a nd more pressure in providing the ser vices
required. Usually the re is o nly o ne officer on duty
to a n swer a ll the enquiries addressed LO him by
pilots, both on the te le phone and by personal
attendance a t the briefing o ffice. The Met. man can
very rapidly become saturated by unnecessar y a nd
sometimes ill-directed enquiries, es pecially on days
or marginal VMC. To alle viate the problem I would
like to make the following suggestions, which, if
adopted by pilots, could help to improve the service
they receive.
Learn the standard abbreviations used in
forecasts
When ge tting weather by telephone it is much
easier a nd quicke r to write "SCT CU 2000 COT
5000 MON TOPS 10 OOO" than "scattered cumulus
base 2000 feet a l the coast, 5000 feet above
mountains tops to l 0 OOO feet".
Learn the format of Area Forecasts
Apart from some central Australian areas, winds
are always given at the levels 2000 ft, 5000 ft, 7000
ft, 10 OOO ft, 14 OOO ft and 18 500 ft. Central areas
give a 3000 ft wind instead o f the 2000 ft wind.
Winds are followed by cloud, visibilily, weather,
freezing level, icing and tu rbulence. If these
headin gs a re written down before ringing the Met.
man, time is saved a nd the re is less chance of
confusion.
Attend the briefing office
If yo u are de partin g from an airport where there is
a Met. office, please do not ring the Met. man and
ask him to read ouL area forecasts over the
telepho ne. Probably 50 per cent of a ny Met. man's
time is taken reading forecasts to people who could
attend the office to obtain the ir forecast
documentation. By all means ring earlier to check if
VMC exists, and if not, to get an opinion o r when
yo ur flight could be possible, but do not ex pect the
Met. office 1· to read the forecasts word for word.
Give details when requesting a forecast
When calling the office for a forecast, do not just
say, " Ma y I have an Area 21 please". Give some
details. Tell the officer (a) your poinr of departure,
(b) yo ur destination, (c) any p lan ned departure
from the d irect route, (d) yo ur intended altitude,
(e) whether yo u are fl ying IFR or VFR a nd
(f) estimated time of depanure. This gives the Met.
man a full picture of your pla ns and your
requirements and he can immediate ly give you the
most importan t details first, e.g. SIGMETS, reports
24 I Aviation Safety Digest 109
of non YMC etc. I t also allows him ro p recis the
forecast by omitting information not re levant to
yo ur flig ht.
Read the forecasts, then discuss them
On arrival at the o ffice, pick up the forecasts, read
them and then ask the Met. mau abo ut any
problems or clarification. rr you are told that your
planned fli ght is unlikely to succeed due to non
VMC conditions, yo u will also be advised of the
time when VMC is likely to exist. Check agai n with
Met. about this time, not every 15 minutes un til he
is read y to th row something at you.
Order flight forecasts
If you are planning a flight covering mo re than
four areas or which has a stage covering more than
two areas or the duration of which exceeds the
validity of the Area Forecasts, you are entitled to a
fli ght forecast. Rin g any Met. or Flight Ser vice
office at least three hours before you require the
forecast and order it. Three ho urs notice should
also be given if you require Terminal Forecasts
which a re not iss ued routinely. lf the flight will
cover more than two FlRs or is of more tha n six
hours duratio n, at least eight hours notice should be
given.
At the same time as you oTd er the forecast, you
can check the gene ral situation a nd maybe cha nge
yo ur plan s accord ingly. If you do no t o rder the
forecast, you could be delayed considerably while
the Met. officer sends messages here, there a nd
ever yw here for f(wecasts that are not available
ro utinely at the briefing office. I f yo u are going to
ring the o ffice fo r a forecast just consider this
example - a flight forecast from Taree to Ade laide
is m uch easier to write clown, and less time
consuming, than geu ing a reas 20, 21, 22, 30, 50
and the T AFORS read over the p ho ne.
Send AIREPS
AI REPS are one o r the most useful aids 1he1·e is for
a briefing o rlicer. Ever ybod y asks for then: but
nobod y gives the m, and the importance of a report
on clo ud, weathe r, visibility a nd turbu lence can not
be stressed enough. Just th ink for a min ute. When
was the last time you sent one, and when was the
last time yo u asked for actual conditions? T he
AIREP you send today could enco urage someone
else to send one in your hour of need.
A little thou ght by pilots would e nable us to give
you a better service. Met. men, like pilots, make
more mistakes when under pressure. Reduce the
pressure and you should get more accura te and up
to elate in forma tion, in turn leading to a safe r
flight .
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On reaching llight level 230 afte r a no rmal climb
th e pilot leaned the mixture for cruise power and
noted that the indicated outside air temperature
was min us 28 degrees Celsius. Even though full
cabin heat was applied, ice formed on the inside of
the cockpit and cabin windows.
The aircraft had been cruising for abou t 10
minu tes when the left engine began to r u n roughl y
and misfire. The p ilot carried out all the
appro p r iate trouble checks bu t found nothing
wrong. He elected to return and no tified A TC
accordingl y. Engine instrument indications were
normal a part from low cylinder head temperatures
which nevertheless we re still with in the normal
o perating range. The left fuel flo w was flucLUating
as the engine misfired.
During descent to flight level 120 the pilot
shutdown the left engine and fea thered the
propeller. A TC declared an Alert phase of
emergency on the aircraft and a fe w minutes later,
after the pilot reported that the right engine had
begun to ru n roughly, this was upgrad ed to th e
Distress phase.
The a ircraft main tained fli g ht leve l 120 for a
short time before con tjnuing descent to 8000 fee t.
During this furthe r descent the right engine
operation im proved and shortly afterwa rds the le ft
e ngi ne was re-started. The SAR phase was
downgraded and the aircraft landed safely about 50
min utes a fter the initial p roblem.
Subseque nt inspection of both engines did not
re veal any positive indication of mechanical
problems and attentio n was then turned to the
possibility of fuel ice be ing the cause of the rou gh
running en gines. All a viation fuel contain s some
water in a d issolved form , i.e. in solution , and the
fue l is a lso likely to contain water in a liquid fo rm,
i.e. in suspe nsion. Pre- flight d raini ng should
remo ve the free water accumulation from the tank
sum ps but small amou nts will still rema in in
solut ion in the fuel. This water will norma ll y be
co nsumed witho ut affecting the smooth operation
of the engine.
.
However, add itional wa ter may be absorbed into
the fuel o n ve ry h u mid d ays and th is water will
precipitate out or the Fue l at very low o utside air
te mperatures. This is p recisel y what ha ppens a t
high altitudes, i.e. above 20 OOO feet. T he small
amou n t of water that has been held in solution in
the fuel will precipitate out and freeze in su fficient
quantities to cause partial icing in the fuel syste m.
This conditio n can readily occur , since the
In ternational Sta nda rd At mosphere te m peratu re al
20 OOO feel is min us 24.6 degrees Celsius. At 23 OOO
feet, which was the cruising altitude o f the ai rcra ft
mentioned earlier, the ISA temperature is minus
30.5 de grees.
What can be done to alleviate the possibility of
fuel ice?
The addition of iso propyl alcoho l to the fuel i11
correctly measu red p roportio ns will help by
d epressi ng the freezing point a nd by keeping the
dissolved water in solution. Alternatively, the
addition of ethylene gl ycol monorne th)1l ether to
MIL-1-127686£ specification will give sim ilar
protection.
H owever, a word of warning! Either of these
compo unds must be blended with fuel in exact
p roportions a nd their usage must be approved by
BOTH the en gine AN D the a irframe
manufactu re rs. Th is is to ensure that 110 harm will
be done to the va rious seals, hoses e tc. , of the
complete fu el system.
The permission to use these an ti-freeze ad d itives
and instructions on how Lo blend them are gi ven in
the various man u factu rers' bulletins a nd in th e
curre nt flight m anua ls. Some of these publications
are :
T eled yne-Continental Service Bull etin No. 79-5 ,
Ro lls Royce Light Aircraft Ser vice B ulle tin No.
T-240/ 8,
Lycoming Se rvice Letter No. L-1 72 A,
Cessna Service I nform ation Letter No. ME79-2
and Cessna C usto mer Care O wner A dv isory
No. ME79-2A.
Also the va1·ious fli ght man ua ls, such as the
Cessna 4 14 A " In fo rmation Man ual"
As cau be seen from the p receding parag1·aphs,
info rmatio n abo ut fu el icing is readil y ava ilable to
owners and operators an d it m us t be taken in to
accoun t when plan n ing fl ights at high altitude •
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Aviation Safety Digest 109 I 25
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�The man on the other side
During the final stage of a VFR flight from Moorabbin, Victoria to Adelaide, South Australia, and while
descending towards St. Vincent's Gulf preparatory to a visual entry to the Adelaide Control Zone at
Port Noarlunga, a Beech Debonair struck the top of a ridge 680 feet above sea level, about 40 km
south of Adelaide. The pilot and all three passengers were killed instantly. At the time of the accident,
fog and low stratus cloud covered the hills south of Adelaide and there was extensive cloud above
them.
The report of the accident described and illustrated above appeared in a past Aviation Safety Digest.
It is a familiar story. But how does an Airways Operations officer, either ATC or Flight Service, feel
when he loses radio contact with an aircraft?
had h andled th is d iversion, I found myself
thinking, "This bloke's got his head screwed on."
' I co-ordinated the aircraft's position and
dive rsion with the Ap proach Controller . After
p ass ing Tailem Bend the pilot req uested his airways
clearance and was ad vised that the clearance wo uld
be available when the aircraft was approaching Port
Noa rlunga.
'About 20 minu tes later Adelaide Tower issued a
clearance fo r the aircraft to enter the Adelaide
Control Zone at Port Noarlunga and to cruise at
500 feet coastal to Adelaide . I passed the clearance
to the aircraft a nd it was acknowledged.
'Some sh or t time later Approach (Radar)
requested the aircraft's position. When I queried
the pilot he reported tha t he was crossing the "one
eight zero rad ial". After transferring the aircraft to
the Ap proach freq uency I sat back to enjoy a cuppa
thin king, with refer ence to the Digest and its saga of
weather-related crashes, that at least some pilots
were ap proaching poor weather prepared for
possible diversions.
'Ding! T he App roach Controller's co-ordination
alarm bell ! I an swer Approach . H e ad vises that he
h as no contact with the Beechcraft. I call the
aircraft. N o contact, then Approach ad vise that they
have lost the aircraft on radar. Silence. Distress
phase decla red. Other aircraft are instr ucted to call
the missin g aircraft. No contact. The Department's
SAR organisation gears up for a possible search.
'Sud denly it's 1300 and my sh ift has ended. I
hand over to m y relief and ad vise him of the
situation . " Perhaps he has landed without advising,
could ha ve been too low and out of VH F range" . As
I leave the Flight Service centre I meet a couple of
general aviation p ilots just back from Kangaroo
Island. We decide to d rop in for an ale on the way
home. We chat about the missing aircraft and my
com panions ad vise me that the weather they
e ncountered was pretty rough. They are not very
encouraging. Time to go. During the drive home I
am contin ually going over the morning's
h app e nings. Did I give him the amend ed forecast?
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Some years ~ fter the acciden t, an FSO who was on
d uty at Adela ide Airport and monitored the aircraft
in the last stage of the flight, has chosen to reveal
h is senti ments towards the pilot, the accide nt and
th e subsequent investigation :
'Flight Ser vice Officers are continually
encou ntering the problem of aircraft e n tering non
VMC weather and th is h as probably accounted for
more ulcers th an an y other re lated problem. 1
tho ug ht an a r ticle explaining one o r these accidents
from our viewpoint migh t give a new d imensio n to
an old problem.
'On the day o r the accident I arrived on watch at
0600 a nd commenced to work the air - gro und
circu it cove ri ng eastern South Australia. It loo ked
like being a quiet da y owing to poor weather. In
fact the only aitTraft flying and schedu led to
operate we re IFR aircraft, on charter or RPT plan s,
p lus o ne Sarti me Beechcra ft, VFR from Moorabbin
to Adelaide .
26 I Aviation Safety Digest 109
'Throughout the morning the terminal and area
forecasts were contin uall y bein g a me nded a nd we
we re bu sy d istribu ting the re le van t amend ments to
a ircraft conce rn ed. Broadcasts were pe riodicall y
made to the Sartime a ircraft but at th is stage no
rad io contact had been established with it.
'Midway th rough the morning contact was
established with the Beechcraft. The p ilot sou nded
in good spirits a nd passed a full positio n report at
Bord ertown with an estimate for T ailem Be nd . H e
was given the amended a rea a nd Adelaide term ina l
forecasts and a short wh ile later reported tha t he
was d iverti ng from his flight pla n a nd would be
tracking from Tailem Bend to Port Noarl u nga, not
directly to Adelaide. He notified his in tention to
desce nd ou ts ide controlled a irspace and req uested
an airways clearance to ente r the Adelaide control
zone at Port Noa rlu nga. An a mended Sani mc was
also give n.
'Because or the con fident way in wh ich the pilot
Yes, su re I d id. Did he have any doubts or sound
u ncertain ? No , very sure of himself, gave confide nt
answers to all the questions and gave full revised
details. Where the hell is he?
'That afternoon the news breaks. The weathe r
had been extremely rough but it lifted and the
wreckage of the Beechcraft was sighted. No
survivors.
'Next morning, time to head off to work. I am
rostered on at 0700. On arr ival the atmosphere in
the centre is quiet. No joking. No footy talk. I am
informed that a car will pick me up for an interview
with Air Safety in town at 1000.
'At the Regional Office I am introduced to the
investigato r. A short discussion about past da ys then
down to business. I am given a transcript from the
previous day's accident. It shows all air - ground
conversations and my discussions and co-ordination
with Air T raffic Control, including all the e rs, urns
and ahs. Quite a documen t. After very exact
questioning on the text, the p ilot's expression s and
general attitude, and reasons why I did this and
that, it was ove r. The investigator was satisfied that
we had don e all we could in the circu mstances.
Well, why did he crash? At that stage the
investigator d id not know.
'The details of the accident were e ventually
related in the Aviation Safety Digest as "another
pilot operating in I MC when he was only rated for
VFR." Apparently he had been in cloud prior to
Taile m Bend, was rated for N ight VMC and was
using the na vaids on board to navigate.
Unfo rtunately, after passing the revised details he
miscalculated the time he estimated crossing th e
coast and crashed when he though t he was j ust off
the coast. How far inland was he? Just 400 metres.
'Whenever a pilot continues on into areas of
marginal VMC the blokes on the ground, the Flight
Service O fficers and Air Traffic Controllers, start to
get concerned . We can only try. It's up to the pilot
to heed and divert. And if it's too late to diver t tell
us of yo ur problem and we will tr y damned hard to
help you out' •
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Aviation Safety Digest 109 I 27
�MD and the jet fuel
Remember Murphy's Law? 'Anything that can be done the wrong way, sooner or later will be .. .'.
Once again the Man in the Dustcoat (MD) shows us how easily Murphy's Law can catch the
unsuspecting.
It was Lea lime on a crisp , winter's mo r ning a nd the
staff o f Murph y's Aeroplane Company d ecided lo
ma ke the mosl of the fine weather. They were
sitting around outside the hangar, enjoying thei r
coffee and sand wiches when , withou t warning, a
light tw in passed low overhead on a high sp eed run .
As it pulled up the sun reflected o ff its bright n ew
paint.work. The aircraft turned and h eaded back
along the strip on a no the r p ass.
Murph y came ou t fro m his office to sec what was
happening a nd as h e and his e mployees watched,
lhc lwin broke o n to down wind , the wh eels
d rapped and the a ircraft made a tight, low level
circuit.
'That will be Fred ' said Murphy to the group.
'Phoned me last nig hl and said he would bring
d own his new plane to show us. Wants us to service
it'.
The twin comple ted its landin g a nd tax ied to the
front of the h a ngar. As the engines were cul, th e
wa rning siren for the end of 'smoko' sounded.
'Okay , you lot' exclaimed Murph y, 'bac k to wor k.
I do n't pay you Lo sta nd a round gawking!' Murph y
overheard a m utte red 'slaved r ive r' as they headed
into the hangar.
T h e cabin doo r of the aircraft opened and the
pilot stepped out on to the wing-walk. 'Gidday
Murph ,' h e said, 'how do you like m y new toy? Ain' t
sh e a beaut!'
'Looks greal, Fred ,' responded Murphy to the
e11th usiastic pilot. 'Cost you a few bob I be t. '
'Sure d id ma te, but I'll be a ble to write most of it
off against the bu siness . I brou ght all the manuals
with me so wh y don't we sit d own and work out
how much the servicings will cost.'
'Okay, Fred. I'll get us a cu p of coffee.'
'Oh , listen Murph , could you have o ne o f the
boys fill it u p with some hundred? Save me some
time la ter.'
As they walked towards his o ffice Mu r phy called
out 'H ey, MD, how a bou t gelling u s some coffee,
then fill u p Fred 's plane.'
'Alrighl,' re plied MD , and under his breath,
'nothing but a . . .·tea lady.'
Murph y a nd Fred were mulling over the
mai nte nance ma nual wh en MD arrived with the
coffee. No t wishing to d isturb the m , he put it d ow n
wilhouL talking and we nt o u t to th e new aircraft. As
he walked a ro und it admiring the smooth lines and
colourful paint scheme his eyes cau ght lhc sign on
th e engine nacelle. 'Turbo-system' MD thoughL
a loud, 'must have those small turbines driving the
p rops. I guess it uses j et fuel. Should ch eck Mu r ph y
bu t I'd be tte r not d istur b hi m while he's talking
mo ney. H e'll do his block.'
MD wen t around th e back of the hangar to the
old fuel La nker th at contain ed th e j et fuel. T h e
28 I Aviation Safety Digest 109
tanke r had not been used l(ir q uite a while and
after a lot of trouble MD got it sta rted a n d drove it
round Lo th e plan e. He had u nrolle-d the fuel hose
and was abou t to fill the tan ks wh en Murph y
stomped out o r his office.
'What th e blue blazes are you up to MD?' roared
Murphy.
Tm fillin g the tanks, like yo u said to, Boss' MD
cowered before his enraged employer.
' But that's j c t fuel you 're usin g, blockh ead,
instead of hundred!'
'Gee, Boss, I sa w the d ecal and tho ught it had
turbines.'
just the n the own er j oined the gro up. H e had
heard MD's last comment and with du t further ad o
turned to Mrn·phy and said, 'Get out the sp raygun
and paint oul those signs M urph . just as well I
didn't get ai1·borne with jet fuel in the tan ks. While
the painter is at it h e can rep aint the fu el grade
signs alon gside the fi lle r caps in larger letters. T hat
sh ould help stop this h appe ning again . I g uess we
sh ould have been a bit more careful wh e n we asked
fo r the fuel , e h , Murph. Not all MD's fa ult you
know.'
Whe n Fred 's aii-craft left Mu rph y's that afternoon
the ta nks were full of Avgas I 00 a nd the nacelle
signs had been removed. The exper ience had been
a nother e pisode in MD's contin ui ng ed ucation.
Cases of inadvertent u se ofj et fu el in aircraft fitted
with reciprocating en gines arc becom ing more
wid espread . Needless to say, th e result can be a loss
of engine p ower, someti mes followed by d isastrous
consequences.
Basically, two situations a re arising regularly
aroun d the world. In the first instance, j et fuel is
added to the air craft tanks as a resu lt of
carelessness. T h e maj ority of ge neral aviatio n
a ircraf t are refuelled ove rwin g irrespective of
wh eth er they are turbi ne or piston-e ngine. Nozzles
fitted to fuelling hoses are common to all fuel types
so that ca re must be take n by th e person refuelling
to ensure thal the bowser or tanker th ey are us ing
con tains the correct typ e an d grade of fu el for the
aircraft being refuelled .
The o ther set of circu mstances is d e picted by our
Man in the Dustcoat a nd is anoth er example of
Murph y's Law al work. Many aircraft now being
produced arc fi tted wi th tu r bo-charged or
tu rbo-compounded reciprocating engines.
U nfortunately a large proportion o f these arc
delivered from the ma nufacturers with d ecals on
nacelles, tip tanks , etc., which easily mislead
refuellers into believing tha t the aircraft are riued
with turbine engines. Consequ e ntly the aircraft
tanks are filled with jet fuel. I n add ition, a n umber
\
�-=~=::_=-.:-..:-1------~-
of manufacturers are producing both piston and
turbine-engine versions of similar aircraft. Typical
examples are :
Piston-engine
Turbine-engine
Rockwell Strike
Commander
resembles
Cessna 404 Titan
resembles
Beech Queen Air
resembles
Piper Navajo Chieftain resembles
Turbo Commander
441 Conquest
King Air
Cheyenne
Cure for these problems
to the first problem would be to
mLroduce a system of different fuel nozzle sizes for
different grades of fuel. Aircraft overwing fuel
orifices would also be sized to prevent the
inadvertent delivery of jet fuel to piston-engine
ai rcraft. This procedure was used successfully by
the Royal Air Force in the United Kingdom by
~nlarging the outside diameter of nozzles supplying
Jet fuel and sleeving the refuelling orifices of all
piston-engine aircraft. Such a modification to
civilian aircraft is highly unlikely as it would require
acceptance by aircraft manufacturers, operators and
refuelling organisations as a mandalory
!he ideal solution
-- - ---
modification. The cost and time involved would be
prohibitive.
The obvious immediate solution is sufficient care
on the part of the person refuelling an aircraft to
ensure that the grade of fuel they are add ing is
correct. Before placing the nozzle in the fu el tank
opening be sure tha t the marking shown on the
tanke r or bowser corresponds with the fuel grade
marking on the aircraft.
The solution to the other problem is simply to
remove or paint out misleading decals and, in the
case of similar aircraft types, to ensure that the fuel
being delivered is the same type and grade as that
indicated on the aircraft.
Pilots and operators can prevent
misunderstanding by being more specific when they
order fuel for their aircraft. When placing the
order, preferably in writing, state clearly the type
and grade of fuel, the quantity to be added to each
tank, or the total amount required at Lhe e nd of
refuelling if less than full tanks.
Operators and owners should also e nsure that the
fuel grade markings adjacent to fuel tank caps on
aircraft are maintained in good condition •
Learn to say 'No'
How often have we fe lt ill-equipped to carry out a
flying task ? Possibly we are weary, or pre-occupied
with personal affairs, or just plain unfamiliar with
the aircraft or its equipment. Perhaps we have been
poorly briefed on the task or perhaps we have
carried out a task so man y times that we have
become complacent or even bored . How often then ,
have we succumbed to various pressures (the BOSS,
get-home-i tis, saving face) and have become
airborne only to regret our action later? Usually we
kick ourselves a nd vow never to do the same thing
again, but often we do and sometimes the results
are rather more dramatic.
It was one of those days when pa perwork kept
piling up - a ll to be done yesterday. On top of this
workload the pilot was asked to carry out a check
flight on anot her pilot. He agreed to do so, but only
if no one e lse was available. Predictably, this was Lhe
case.
The check pilot briefed that he would adjust the
flaps for· the pilot during touch and go landings.
His normal procedure for doing this was to point to
the flap handle, say 'Flaps identified' and then
activate the handle. On the first touch and go, the
check pilot inadvertently selected the gear handle
up instead of the flap handle. The nose and main
gear collapsed even though he re-selected the gear
handle down a lmost immediately. The aircraft
veered off the runwa y and stopped on the grass,
substantially damaged. The check pilot recalled
some time after the accident that when he selected
30 I Aviation Safety Digest 109
the gear handle up he must have actually identified
the handle because he remembered saying 'gear
up'.
The check pilot was not mentally prepared for
the fli gh t due to workload, short notice for the
flight and lack of current practice in check
pilot/ instructional flying. In addition to this, he had
flown about I 00 hours in the previous 12 months,
divided between 19 different types of light twins
and singles. Although many of the types were
similar, the pilot had flown too few hours on too
man y types of aircraft to be properly proficient on
any one of them.
The lesson to be learnt from this accident is clear:
If yo u feel 'switched off then keep the aircraft
switches off - saying 'no can do' can avoid much
embarrassment•
�
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Aviation Safety Digest, number 109 (1980)
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109
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1980
-
https://collections.heritageoftheair.org.au/files/original/11f9a4406c94742bd33c5531a2a87666
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PDF Text
Text
108/1979
Department of Transport - Australia
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Contents
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Change of address:
Rtade/$ on the free distribution Hst 8hoUfd
TliOSPOlt, P. O Box 18390, Melbourne,
Sllbferlber& should contact the Australian
strvlce
@Commonwealth of Australia 1979. The
may notbe reproduced In whole or In pll1f,,
lty of the Depattment of Transp~ Whn
extracted from or based on another
Oliglnator shtJuld be sought. The views
bodies In attlcles reptOduced In the Avfalion
IOflfCeB are not neoeBlllJl'fly those of the
21
P1tot contrbdlOn
A PIOl on flnal alJPIQ8Ch to a country alnstrlp was llarlled to
tee another aircraft flying on a parallel coul'lt at the tlnl•
allltude, about 200 feet to &tarboard.
28 Boelna 727 descends lrito the aaa
.@!.
While making a non-precision Instrument apPiQ'lioft1
to Penaacola Aegtonat Aftport, Florida, a aoetnil~m
descended Into the sea about thl'H n~ Intl•~
the runway threaho{d.
2 / AvlatfOn Safety Olg88t108
At 0145 hours EST a Piper Navajo Chieftain struck the ground about two kilometres to the north-east
of Melbourne Airport while attempting to return for an emergency landing. The aircraft was destroyed
by impact and subsequent fire and the pilot, the only person on board, was fatally injured.
The aircraft was based at Moorabbin Ai rpo rt and,
late in the afte rnoon, it was refuelled and a
pre-flighL inspection was carried ou t. The pilot
ferried it to Melbourne Airport just after mid nigh t.
While he was preparing and submiuing a flighL
p lan to Canberra and retu rn , the aircraft was
load ed with newspapers and a small quantity of
other freigh t. On re turni ng Lo the aircrafl, Lhe p iloL
checked Lhe loading d ocuments a nd the freigh t a nd
made a walk-around inspection of the exterior of
th e aircrafL.
The pilot started the engines and establishec~
radio communication with Air T raffic Control at
0 139 ho u rs. He was give n a taxi clearance and an
airways clearance fo1· d epartu re from ru nway 34.
Upon request, he was granted approval to
commence ta ke-off from the taxiway']' inte rsecLi on ,
some 800 me tres from Lhe southern end of the
runway. He reported 'ready' at 0 143 hours a nd was
imm ediately given a clearance to take-off. T he
aircrafL took off and, when it was at a height of 100
to 200 feet above th e intersection of the depar ture
runway a nd runway 09/ 27, Lhe piloL advised ' ...
got a fire - fire in the - ah - starboard engine
a nd - a h - doing a low circuit request two seven'.
ATC immedia Lely replied' . .. make visual
approach runwa y two seven clear to la nd'.
Acknowledgement of this clearance was the last
communication received fro m th e aircrafL.
As it passed over the north ern e nd of runwa y 34
the aircraft comme nced a tu rn to the rig ht and
gradually d escended. It struck the grou nd in a righ t
wing down a ttitude on a track of 070 degrees
magne Lic and an intense fire broke ou l. T he
accident site was 1.8 km to the north-east of ru nway
34 a nd 88 feet above the elevation of the north ern
e nd of that runway.
AL the time of the accident Lhe surface win d was
330 degrees at nine knots, the visibility was 25 km
in passing showers, there were th ree oktas of stratu s
cloud, base 1800 feet, and six oktas of cumulus
cloud, base 3500 feet. It is probable that below 1OOO
feet there was some wind shear, d owndra ughts
from passing showers and intermittent moderate
tu rbu lence.
I t has been calculated that the gross weigh t of the
aircraft was 65 kilograms in excess of the maximu m
take-off weigh t and the centre of gravity was within
limits.
A detailed examination of the wreckage of the
aircraft revealed that the landing gear a nd flaps
were fully retracLed, Lhe cowl flaps of both engines
were midway between the open a nd closed
positions, a considerable degree of nose-left rudder
trim was selected, Lhe right engine was closed d own
and the propeller feath e red.
I t was established that, as a resulL of excessively
lean mixture operaLion, there was a hole burned
through the piston r ings a nd into Lhe side of the
no. 2 piston of the righ t e ngine. There was no
evidence of fire within the e ngine compartmen t bu t
it was apparen t that the hole in the piston had
resulted in pressurisation o f Lhe cran kcase cavity,
ejection of the oil dipstick, a nd the consequenL
ventin g of oil from th e d ipstick orifice and the
e ngine breathe r pipe on to the exterior of the
exha ust pipes. The e ngine had the capaciLy to
continue to produce a substantial amoun t of power
fo r a limited period .
The turbo-charger density controller of the left
e ngine was found to be incorreclly adjusted to the
exLe nt that the e ngine could develop only abou t 330
BHP instead of 350 BHP which was its normal
ca pability.
T he probable cause of the accident was that,
believing there was a fire in th e right engine
compartment, the pilot closed th e e ngine down in
circumstances where the single-e ngine performa nce
capability o f the aircraft proved to be insufficient to
sustain continued flight.
Aviation Safety Digest 108 I 3
�This accident involved a modern, relatively
sophisticated light twin which was unable to
continue flying following an engine shutdown
shortly after take-off. Why?
The arLide 'One down and one to go' in Aviation
Safety Digest 105 dealL in d elail wiLh Lhe
requirements for light twins and the factors which
affect the ir single-engine performance. Let us now
consider those factors in relation to this accident.
At the outset it is important to remind ourselves
thaL the p erformance requirements for ligh t twins
call for demonstration of engine-out performance
o nly in Lhe en route configuration. Take-off,
approach and landing are not considered.
The Australian one-engine-inoperative climb
requirement for light twins engaged in IFR
operations is the achievement of a single-engine
climb gradient of 0.5 per cent under the following
conditions:
• Altitude 5000 feet AMSL
• TemperaLure + 15 deg rees Celsius (ISA + 10)
• Propeller of inoperative engine feathered
• Landing gear and flaps re tracted
• Ma~imum continuous power from the operating
engme
• Maximum Lake-off weight.
In establishing the required cerLificalion
performance it is permissible Lo fl y wi th up to five
degrees of bank towards the operating engine.
For the Piper Navajo Chieftain the 0 .5 per cent
climb gradient at besl rate of climb speed under the
above conditions is equivalent to a rale of climb of
aboul 55 feet pe r minute .
In the performance sectio n of the piloL's
operating ha ndbook for the Chieftain there is a
ch art which gives single-engine rales or climb for
varying conditions of Lemperaturc, aircraft weight
and pressure a!Litude. The chart indicates that on
the nig ht of the accident, with the temperature at
16 degrees Celsius and at an altitude of 500 feel,
the aircraf'L should have been cap able of a
single-e ngine climb rate of 220 feet per minute, i.e.
a two per cenl g radienl, at maximum take-off
weight. With this anticipated rale of climb the
aircraft should have been able to complete a safe
return Lo the aerodrom e on o ne engine.
In the event, Lhe aircraft was unable to ach ieve
anything li ke this climb performance. It is probable
that the same could be said about ma ny similar light
twins of comparable age being flown under the
sam e conditions. The reasons for not achieving the
expected rate of climb coul d include Lhe following:
• The pilot's reactjon and performance in the
emergency siLuation
• The age and condition of the airfram e
• The power available from the operative engine
• The aircraft's flight attitude
• The aircraft's gross weight.
We will now discuss these factors in d etail.
Pilot reaction and performance
The figures given in the perfor mance charls
p ublished by the manufactu rer are based on the
r es ul ts of Lest flig hts conducLed by a professio nal
tesl pilot unde r conLrolled condi6ons, being
pre-pla nned exercises specificall y flo wn Lo
determine single-en gine performa nce in the en
route config uration . Unde r such condition s the test
4
I Aviation Safety Digest 108
pilot is readil )' able to set up a nd maintain the
a ircraft in th e r equ ired configuration fo r the
duration of the tesl. The res ult is, of course, the
achieveme nt of optimum performance f'or the
airc raft a nd the objective is simply Lo demonstrate
that the aircraft mee ts th e required level of
performance.
On the other hand we have a pilot faced with a
dire e mergency in a sligh tly overweighL aircraft,
very close to the grou nd on a d ar k night. H e has
probably had li ttle pract ice in asym me tric flight at
high gross weights a nd more than likely has never
been faced with a siluation such as this, which
requires him to rapidly set up the aircraft in the
appropriate single-engine configuration and to keep
it fl ying at its o ptimum performance level.
It is quite obvious that the piloL in the emergen cy
situation is unlikely to rapidly achieve and Lhen
maintain an ai rcraft perfo r mance eq uivalent to that
o bta ined by Lhe test pilot during the test program.
Age and condition of the airframe
Apart from the conditions mentioned in the last
section as being necessar y Lo ach ieve the
performance charl results, the tesLS would also h a ve
been flown in a new aircraft or one in excellent
condition. CondiLion of Lhe a irframe can deterio r ale
in ser vice and all the small dents, chipped and
flaked paint, and misfitting doors and hatches will
tend to reduce the aircr aft performance.
This partkular Chieftai n had flown aboul 3400
hours since new. An estimaLed degradation of
performance for this aircraft is a reduction o f Lhe
single-engine climb g radient by aboul l 00 feet per
minute, which m eans that almost half the
anticipated single-engine climb performance has
been lost for this facto r alone.
Power available from the live engine
As m e ntioned earlie r the o perative engine o n th e
aircraft was nol d elivering its maximum rated
power. The pilot's operating handbook fo r the
Ch ic!'tain contains a power setting chart which
shows the manifold air pressure (M AP) which
should be ex pected for m aximu m ra ted power
un der varying conditio ns or Lemperalure an d
altitude. The engine Lurbo-ch argers are fitted with
densiLy controllers and the maximum MAP
obtained will vary with ambie nt cond itions . T here
may even be small differences between individual
e ngines. It is importanl for pilots to know wha t
MAP values should be expected for max imu m rated
power under vario us am bie nt conditions.
T he estimated effect of th e lower-tha n-normal
power on the left engine i n this case was a loss of
approximately 75 feet per minute rate of climb.
Aircraft attitude
The single-engine climb performance charts in the
pilot's operating handbook for the Chieftain are
based on the aircraft being in a five dei:vee bank
towards the operative engine a nd Lrackmg alo ng a
straight line . The reason for this is Lo reduce the
total drag of the aircrafl. The Lu rn p erformed by
this aircraft, a fter the engine was shut d own and
assumin g that th e pilot mainLai ned the .besl
single-engine rate of climb speed , r eciwres a ba nk
a n gle or 15 deg rees away . fn~m the live engine .
The estimated effect of Lh1s factor was a ru rther
loss of about 40 feel p er minute rate ol' climb.
Aircraft gross weight
The calcu la ted ta ke-oil ll'eight of' Lhe aircraft " ·as 65
kilograms above the maximum permissible; this
further redu ced the single-engine rate of climb br
abou t 25 fee l per mi nu te.
Net effect on performance
Wit hout evalua ti ng the effect of the pilcn's
perform a nce o n the climb capabiliL)' of the airc1·a['t,
th e u cl effect o f the other fou r factors m entioned
resu ltecl in a probable reduc tio n of the
singl e-e ngine rate of climb by about 240 feet per
minute; in other "·ords the aircraft could no t be
expected to ma in tain heig ht, let alone climb.
What could have been done to overcome the
degrading effect of the above factors on the
aircraft's single-engine climb performance?
Regular a nd thoro ugh mai11te11ance of the airframe
will he lp to limit the poten tially critical performance
loss r es ulting rrom airfram e condition .
Power availability is also dependent upon
mai n te na nce , and ser vici ng orga nisations must
ensur e they use the correct procedures \\'hc11
adjusti ng e ngines fo r maximum power o utpu t.
Pilots can confir m these settings by ensuring l hey
k110\\· the cockpit indications to ex pect in the
ambienl conditio ns pr evailing.
It is essential that p ilots of all ai r craft be familiar
with the pe rformance capability of the a ircr aft they
arc n r ing, especiall y when opera ting al or near the
maximum pe rmissible \\'eight. Do not be lulled into
a false sense o f security by the en route climb
certification requ ire menls. Following an engi ne
fa ilure just after ta ke-oil, a light twin wit h the
airc raft weight close to rhe maximum permissible
will probably n ot main1 ai n height , because of the
facto rs me ntioned earlier.
Lea rn to betler ap pr eciate the lim itations or the
a ircr aft by practising engine fa ilures al a sa fe
h eigh t, but with the aircr aft al a high gross weight
a nd in the ta ke-off config uration . Reduce power Lo
the zer o th rust setti ng a nd you may be surprised,
ind eed disappointed , but al least )' OU will be more
aware of the capabili ties of the aircraf t and yourself.
The qu estion or aircraft attitu d e in connection
with this particula r accicle11l can o nl )' be answered
with conside rable coujectu r e regar ding the pilot's
reaction to the appa re nt engine fire and his
kncmlcdge of th e a ircra ft's single-e ngine clim b
capability.
The piston failure that occurred in the right
engine a llowed th e cr ankcase to pressurise and
forced oil o ut of' the engine br eather pipe a 11d the
oil fi lle r access. Th e oil evident ly ignited when iL
came in coutan wit h the hot exhaust a nd this
~bviousl y gave the pilot th e impression or an engine
hre. Examinat ion of the cowls fro m the righ t
engi ne showed that there had been no engine fire
prio r to impact, but the lire r eferred Lo by the p ilot
may have been local flari ng of oil droplets as the y
con tacted the hot exh aust pipes.
Ther e have bee n nu me rous piston fa ilures in
ligl1L Lwim but most ha ve occurred du ring daylight
hours. Whe n such fa ilures ha ve occurred pilo ts
have seen oil streaming on Lo the cowls an d / or
srnoke. Had it been night-time the y might \\'ell have
noticed an indication or fire. The pilot's operating
handbook emergency procedures require that, in
the event of an engine fire in flight, the engine is
shut dcmn and secured and th e aircraft is landed at
the nea1'CSL sui table aerodrome. The p ilot of this
aircraft ll'as obviousl y following that procedure. To
land at Lhe nearest suitable airport req uired o nl y a
gradual turn to r each runwa y 27 at Melbourne and
th is 11·as the pilot's decla red inLention .
It cou ld not be established if the pilot knew the
single-e ngine performance he could expect from his
aircraft. If he believed that the figures given in the
pilot's operating handbook were applicable, h is
decision to shut d own the engine and Lurn towards
the aerodrom e is understandable. If h e was awar e
of the likely single-e ngine p erformance capabilit y in
the prevailing circumstances, it musl be concluded
Lhat his concern about the appare nt engine fire
overrod e that knmdedge and for this reason he
chose to tu rn the aircr afl towards the aerodrome,
Lhcrcby sacri ficing som e of the r ate of' climb.
It becomes quite obvio us that Lhe o ne factor
which is most readily controllable to improve the
single-engine perfor mance is the aircraft's gross
weight. Any reductio n in gross weight will ach ieve a
corresponding increase in si uglc-e ngi ne climb r ate,
a nd for most light twins the benefit lo be gained is
about 15 to 20 fee t per mi nute for each o ne per
cent dec rease in weigh t. It is clear ly importanl for
all pilots of' light Lwins to r ecognise not only the
serious consequences of overloading their air craft
b ut also the read y m eans which exist for enhancing
the single-e ngine performance by a red uction in
a ir craft weighl.
The Australian design sta ndards have been
cleveloped o n the basis of achieving a satisfactory
r ecor d over the complete spectrum of operations ,
but it is vital to remember that the requi rements for
single-engine performa nce in light twins relate only
to th e en ro ute phase of flight wi th the aircraft in
its lowesL-d rag configur ation. Pilots mus t a lso
r emain aware of their own performance limitations
in res pect or their abilit y to react quickly and
effectivel y in the case of an u nexpected engin e
failure in a mor e critical p hase of fl ig h t. II' you ha ve
a ny doubts as to your own o r your aircraft's abili ty
to cope wit h a n engine failure in flight you should
careru lly consider the desirability of keeping the
aircr aft weight LO a level wh ich will provide
additiona l single-engine climb ca pability.
From the investigation findings we know that the
pilot did not need lo shu t dow n the engine
immediately. If he had reduced powe r o n th e
suspect e ngine, the rate of oil sp illage would have
red uced a nd so too would the symptoms or the
apparen t fire. H e could ha ve the n gained sufficient
altitude and positioued the a irc1·a f't for a safe
land in g before shu tting clown Lhe e ngine.
Wi Lh the benefit or hi nds ig ht we can say that the
accident became inevitable wh en the pilot sh ut
down the engine ; however, he probably did not
know the r easo ns !or th e apparent fire. It must be
concluded that his concern about the engin e fire
was appare ntly rar g reater than a ny concen1 abou t
single-engi ne perform ance . ~e rh aps if' he h ad full y
understood this aspect, h is course o f' actio n wou ld
have been differe nt•
Aviation Safety Digest 108 I 5
�Child restraints in general aviation
aircraft
For some time now child restraint devices have been
used in motor vehicles and have proved to be
ca pa ble of pro tecting children in moto r collisions
from what otherwise would have been more serious
injury. T he use of s uch devices in ge ne ra l aviation
aircraft is full y supported by the De pa rtment of
Transport as lo ng as the means of installa tion is in
accordance with manufacture rs' recommendations
and the items used are of the requi red sta ndard.
A recent le tter from an interested pilot suggested
that an article on this subject in the A viation Safety
Digest would be o r use to gene ral av iatio n pilots.
The following extract illustrates his concern.
' For some time I have bee n wa nting to take m y
15-mon th-old daug hter flying, however, I a m
co ncerned a bo ut her safety if she is just held by m y
wifr. I ha ve been considering th e use o r m y
automoti ve child seat which uses the existing
la p/sas h seat be lt. or course, this could o nly be used
if the aircra ft is fitted with a similar la p/sas h
harness.
' I fee l that there must be ma ny othe r pilots
conce rned over this matter an d th at yo u may be
a ble to investiga te the positio n mo re thorou ghly,
followed by a n a r ticle in the Digest'.
The use of chi ld restraints in gene ra l av iation is
not presen tly covered by a ny mandatory
requireme nts. C hildren constilllte a small
p roportion of those who fl y in ge neral a viatio n
a ircraft, a nd o nl y small childre n need special
restraints; older ones can be adeq uately p rotected
by the use o f a n adult restrai nt system , if n ecessary
combi n ed with the use of an a p p roved child seat.
Neverthe less, adequa te child restra ints in gene ra l
aviation a i1·cra fr wo uld improve the safe ty of all
occupants. They wou ld optimise the ch ild's
protection a nd the protectio n o r othe r occupants
who mig ht, in an accident, be inj ured by a child
throw n abou t in the cabin .
A child restra int a pproved fo r au tomoti ve use is
accepta ble fo r use in ge neral avia tio n ai rcraft if it is
ma nu factured to comply wi th Austra lian Standard
AS 1754 and secured to the aircraft seat or structure
in a manne r capable of resistiug the
e me rgency-la nding inertia forces of 3g upwa rd, 9g
fo rwa rd a nd l. 5g sideward .
C hild restraints incl ude child seats and harnesses
made fo r childre n . T he fo llowi ng ta ble shows the
type o f restrai nt most s uita ble fo1- you r child :
Type of rest raint Approx. age of child
Weight of child
Child seat
6 momhs-4 Y2 years
9 kg (20 lb)- 19 kg (40 lb)
H arness
12 months- I I Yt years
9 kg (20 lb)-38 kg (80 lb)
Restraint devices a pproved fo r auto mobile use and
complying with AS l 754 carry a la be l d isplaying th e
6 I Aviation Safety Digest 108
Child seat
month s or older. Researchers now agree thar it is
safe for even a ver y young ch ild to wea 1- a properly
adjusted adult sear belt.
to the aircraft structure could also be installed
provided a suitable scheme has been submitted to
and approved by the Departmen t.
Notes on installation
Use of restraints
-It is essential that th e child restraint be connected
exactl y as shown in the manufacturer's
instructio ns for the type of device. Buckles and
adjusters should not be located on corners.
- Child restrai nt systems designed to AS 1754 for
use o n a car seat in combination with an adult
th ree-point static harness (i.e. not fitted with an
inertia reel retractor) can be used directly in light
ai rcraft in co mbination with a three-poin t harness
not fitted with an inertia reel. In such installations
the sash of the safety harness is used to anchor
the top of the child restraint.
- Jn locations where the car safety harness is fitted
with an ine rtia ree l retractor a converter buckle is
sup plied wi th the child restraint to convert the
lap-sash harness into a lap belt, and the upper
attach ment is p rovided by an additional strap
connected to the rear parcel shelf. Similar
provisio n m ust be made in the case of a light
aircraft harness fitted with an inertia reel,
particularly in view of the fact that the aircraft
reel has a lockin g th reshold approximately three
times greater than that of the car retractor.
T here fore, whe n the child restraint is intended
fo r a light a ircraft seat equipped with a harness
fi tted with an inertia reel, a nd where it is
physicall y possible to make use of the provisions
available for the same car situation, approval
should be sought from the Depar tment to carry
ou t a small modi fication to the a ircraft structure
fo r connection of the child restraint upper strap.
T he child restraint can then be fi tted to the
a ircraft seat in the same way as it is fitted to the
car seat.
- Other child restraints requiring direct attachment
-Child restraints a re designed to restrain 1th e
skeletal structure of the trunk. Compression of
the abdominal area must he avoided. A harness
should be worn across the lap and the chest.
-Harnesses should be adjusted to fit as firmly as
possible, consistent with comfort, to provide the
protection for wh ich they have been designed.
Undue slack in a harness will greatly reduce the
protection afforded the wearer. Individual straps
of a harness should not be left undone.
-If it is necessary to nurse a child because there is
no child restraint fitted to the aircraft, never
place the seat belt around both yourself and the
child. This could result i11 inj ury to the child as a
resu lt of your weight acting upon h im in an
accident or even under tu r bulence.
- If the webbing becomes frayed, contaminated or
damaged, replacement should be carried out by
the manufacturer or his agent. It is essential to
scrap the entire child restraint after it has been
used in a severe impact even if damage to the
assembly is not obvious.
-Care should be taken to avoid contamination of
the webbing and padding with polishes, oils and
chemicals, particularly battery acid. Cleaning may
be carried out using mild soap and water.
The problem of child restraints in general aviation
aircraft is under constant review. Investigations
carried out for automotive use continually provide
new data applicable to most aviation situations. New
products and corresponding standards are also
being developed. An y significan t developments in
these areas will be brought to your attentio n in the
Digest•
Child harness
Standa rds Association of Australia (SAA) sy m bol
and a re therefore read ily identifia ble. A list of
curre ntly approved ch ild restraints is available fro m
th e SAA Office in the ca pital city of your state.
At present there is no SAA-approved child
restraint for an infant unde r six months or n ine
kilograms. If no special child restraint is available,
an ad ult seat belt is suitable for a child of 12
Aviation Safety Digest 108 I 7
�Meteorology and the pilot
Part 1 - thunderstorms
This is the first in a series of articles which has been prepared to help you better understand the
weather and how it will affect your operations. The series is not intended to be a basic course in
meteorology, nor is it directed specifically to any section of the industry. Basic knowledge will be
gained by studying the Manual of Meteorology Part 2, formerly the Aviation Supplement, and
whatever other publications you need to pass the necessary examinations at various licence levels.
This series is intended to supplement your basic knowledge and provide some techniques to
minimise the pote~tial hazards of natural phenomena.
V/c all kn ow what thunde rstorms look like a nd the
hazards they pose to aircraft : severe turbu le nce,
hail, icing a nd ver y h ea vy rain . to na me just a few.
A thunde rstorm packs into one vicious bundle just
about every weather hazard kn ow n to aviation .
Much h as been written abou t the mecha nics a nd li f"e
cycle or th unde rstorms as they h ave bee n stud ied
fo r m a ny yea rs; but while rnu ch has been lea rn ed
th e stud ies contin ue because there is still a lot more
to lea r11.
Kn owled ge and weather r ada r have modi fied our
attitudes towards th u nde rstorms, but o ne ru le
con tin ues to be tru e - a11 y thunde rstorm should be
8 I Avia tion Safety Digest 108
consider ed extre mel y hazardous. A Imost any
thunderstorm can spell d isaster for the wrong
com bina ti on of aircra l"t a11 cl p ilot.
T o refresh you r me rn o r)', lei us recall thl"
ncccssa1·y i11greclic11ts fo r the formation or a
thunde rsto rm . a nd its li fe cycle.
Ingred ie nts
o Unsta ble air throu gh a considerable d epth o r the
trop osphe re .
•A lifting mec hanism to trigger the insta bility.
•A bundant moistu re through a considerable dep th
of the troposphe re.
Life cycle
Mix the ingredie n ts "·ell and in no ti me at all
cum u lu s clouds 11·ill begin to form . All
th und erstor ms sta r t life as a cumulus cloud but only
a fe\\' cumulus clouds develop into thun<lerstorms.
As the cloud gn >\\·s so does the updraught ll"hich
may reach 3000 feet per minute. Active gro11·th of
the cell to\\'ards the cu mulo-nimbus (thunderstorn1)
stage is indicated by vigorous, clearly defi ned
boili ng at the Lop of the cloud.
Wh en the cloud has grown fully, qu ite often
beyond 35 OOO feet in mid-latitudes and over 60 OOO
feet in the tropics, it develops its characteristic
flatten ed top. Raindrops and ice crystals in the
cloud ha ve grown to such a size tha t they arc no
longer supported by the u pd raught and they
com me nce fall ing, evaporati ng into the clean air
d raw n into the clo u d and thus cooling it, formi ng
strong d owndraughts in par ts of the cloud. Large
wi nd shea rs and severe turbulence occur because of
the updraugh ts and downdra ughts. Precip itation,
possibly in the fo r m of hail, reaches the gro und at
this sta ge.
As th e d owndraugh t grows ver tically and
horizontally, it even tually exten ds through most of
the cloud . Rain gradually decr eases as no new
cond en sation is taking place. T he top of the cloud
become s more fib rou s in a p pearance and the
feathered a n vil continues to extend in area. Withi n
a short time after the cessation of ra in, the cloud
itself brea ks up. The typical life cycle is about 60
m inutes, thou gh some stor ms ma y last several
ho urs.
Scientists estimate that 44 OOO thunde1·storms lash
the earth's sur face every day. At an y given moment
1800 of th e m are in action. T h u nderstor ms come in
ma ny sizes an d sha pes a nd are of ten called 'weather
factories' because of the gr eat va riety of extreme
weath er condi tio ns they can produce. T hey occu r
individually as separate, widely-spaced storms, or in
long squ all lines along or rough ly parallel Lo a
front.
T he most violen t th understorms draw air into
their cloud bases with great vigou r. The incoming
air acquires a rotation al component a nd it often
forms a n extremely concentrated vortex fro m the
surface well into the cloud. Meteorologists have
estima ted th at wi nd in su ch a vortex can exceed
200 knots; p ressure inside th e vortex is qu ite low.
Th e stro ng wi nds gather dust a nd debr is, a nd the
low pressure ge nerates a funnel-shaped cloud
extending downward from the cu mulo-nim bus base.
If the clo ud docs not reach the su rface, it is a
'fun nel cloud'; if it tou ches a land surface, it is a
'torn ado'.
T orn adoes occu r with both isolated and squall
line thun derstorms. Repor ts or forecasts of
tornadoes ind icate th at atmospheric conditions are
favo ura ble for violent turbulence. An aircraft
enterin g a tornado vortex is almost cer tain to suffer
structural damage. Sin ce the vortex extend s well
into the cloud , a ny aircra ft fl ying in a severe
thunderstorm could encou nter a hidden vortex.
Sum med u p, thunderstorms are m eteorological
mo nsters an d a run d amental flying rule is: stay o ut
of th em .
CUMULUS
- - - s1c0
- --3ec0
- ec0
oc0
ec 0
- - - 11c0
CUMULO-N IMBUS
- - - -26C0
-
- - - 19C 0
.. - ac0
oc0
ac 0
0
17C
SURFACE
DISSIPAT ING
o RAIN
*SNOW
E3 ICE
CR YSTALS
Aviation Safety Digest 108 I 9
�Hazards associated with thunderstorms
Turbulence
Potenlially hazardous turbulence is present in all
thunderstorms and can destroy an a ircr aft. T h e
most frequent and severe turbulence e ffects o~<;ur
near ad jace nt updrau g hts and downdraughts m the
matu1-c.storm and res ult from rap id encou nters
with alternately ascending and descending ai r
and/ or a ir ascending o r desce nding al markedly
different rates.
W hile the main problem with the draugh ts is the
large vertical disp lacements ?f the aircraft, .
turbu lence has a twofold eff eel: severe loadmgs on
the a ircraft structure and viole nt changes in attitude
which may result i n ove rloading dur ing r ecove r y.
Ou tside the cloud, sh ear Lurbulcnce has been
enco u ntered up Lo sever a l thousand feet above
ground as far as 30 km later ally f~·om a sever e
slorm. A low level tu rbu lent area 1s the shear zone
associated with the gust fro n l. Often , a ' roll clo ud'
on th e leading edge of a sto rm marks the top of the
eddies in this shear and it signifies an ext1·emely
turbulent zone. Gust fron ts of ten move u p to 25 km
ahead of associated p recipitation. The gust front
cau ses a r apid a nd sometimes drastic change in
surface wind a head of an approachi ng storm.
It is a lmost im possible to hold a constant altirude
in a th understorm, and manoeu vring in a n attempt
to do so produces greatly incr eased stress o n th e
aircraft. I t is understa ndable that the speed of the
aircraft determines the rate of the turbulence
enco u nters. Stresses are least if the aircraft is h eld
in a constant attitude a nd allowed to 'ride the
waves'. To da te, we have no guaranteed way to pick
'soft s pots' in a th u nderstorm.
Hail
Hail competes with Lur bulc ncc as the greatest
thunderstorm hazard to aircrafr. Sup ercooled d rops
above the freezing level begin Lo freeze ..Once a .
drop has frozen , it can grow !·apid ly by 1i:npact with
other drops which freeze on 1t, so the hailstone .
grows - sometimes in to a huge iceball. Large 1.1ail
occu rs with sever e thundersto r ms that have built Lo
great heigh ts. Eventually the hailstones fall to the
ground, possi bly some distance ~rom the .storm
cor e. Hail ma y be encountered 111 clear a ir several
kilometres from dark thund e rstorm clo uds.
As hailstones fall throug h ai r with a te mper atu r e
above zero degrees Celsiu s, they begin t<_> mel t a~1 d
p recipitation may reach the ground as either h ail or
rain. Rai n at the sur face d oes not mean the absence
of h ail aloft. You should expect hail with any
th und erstorm, especially near the updraught o r
core of the cumulo-nimbus. Hailstones larger than
one centimetre in diamerer ca n sig nificantly damage
an aircraft in a few seconds.
Icing
•
Updra ug h ts i n a thunderstorm support ab_und ~nl
liqu id water and , when carried above the lreez1 ng
level, th e water becomes su percooled. When
temperatu re in the up ward cu rre nt cools to ~ b.o ut
min us 15 degrees Celsius, mu ch of the remammg
wa ter vapour sublimates as ice crystals, and above
this level, at lower temperatu r es, the amount o f
supercooled water decreases.
MOTION OF STORM
~--WARM
COL O
c
AIR
OUTFLOW
0
10 I Aviation Safety Digest 108
AIR INFLOW
W ARM AIR
INFLOW
~
~~"--GUST FRONT
Supc;cooled wa ter fref'zes o n impact ." 'ith an
aircraft. Clear iring can occu r a l any alt1Ludc abo ve
the freezi ng level; but at liigh le vels , icing ma y b~
rirn c o r mi xed r ime an cl clear. Th e abunda nce of
supercooled water ma kes clear icingvcry rapid
between zcrn degrees Celsius an~! mm us .15 degrees
Celsius, and e ncounters can be frequent m a cluster
of cells. Th u nderstorm icing can be extremely
hazardous.
Airframe icing is no t alwa ys a problc_i~1 with
individual thunde rstorms, particularl y if th e lateral
extent of the storm is not great resulting in a small
exp osure time to icing conditions. I;Jowever, the
potentia l for heavy ir ing is p r esc.n t 111 each storm
and fo r this rf'ason a cluster or !me of
thu nde rstorms ma y present seriou s airframe icing
problems.
. ..
For pisi-on e ngin e aircraf"t th ~ poss1b.1hty of
inductio n icing is ever prcsem in certam . .
combinations of temp erature, relative h u m1d1ty and
visible mois ture. En gine in take icing a nd the
ingestio n of hail a nd wa ter arc constant proble ms
for turbine- power ed aircraft.
.
The bcsL remed y for a ll icing is prevention . Use
of a nti-icing ef]ui pment before entering an area of
possible icing conditi ons should ensu:e a sa'.~ .
passage. If the aircraf"t is not fitt~d 1~11 th anL1-1c111g
equipme nt, o r if iL was not used 111 lime, th~ correct
use of de-icing eq u ipment, in accordance with the
pilo t's operating ha ndboo k, should reduce the
effects or th is hazard.
Low ceiling and visibility
. .
Obviously, visibility is near zero w1t·h·111· a
thu nderstorm cloud. Ceiling and v1s1b1hty also may
be restricted in pr ecipitation and dust. b~twee n the
cloud base and the ground. The resn:1~t1?.n s create
the same proble m as a ll ceiling and v1s1b1~1L y
restrictions , but. such hazard s are greatly mcrcased
when associated wi th the other thunderstorm
haza rds of turbulence , hail and lightning which
make pr ecision instrumen t flying virtually
impossible.
Effect on altimeters
Sur face pressure usuall y falls rapidlr with the
.
a pproach of a thu nderstorm , the~ n ses sharply with
the onset or the first g ust a nd arri val o~ th_e cold
downdra ug h t a nd heavy rain shower s.' falling back
to normal as the stor m moves on. This cycle _of
pressu r e cha nge may occur in 15 m i.n utes. If tl~e .
pilot does no t r eceive a corrected altimeter settm g ,
his altimeter i nd ication ma y be m o re than 100 feet
in error.
Lightni ng
.
A lig h tning strike can puncture t~e s~m of a n
aircraf"t a nd can damage commurncations and
electronic navigational equipment. Ligh tni ng; has
been suspected of i gniti~1g fuel .vapours causm g
explosion ; however, senous acodents ~ause? by
lig htning str ikes a re extremely rare._ L1g h.t111ng can
momen taril y bli nd the pil<:>t, re n?enng him
te mporarily unable to navigate either by .
.
instrum en ts o r by visua l reference,_and ligh trnng;
can also induce pe rm ane nt errors 111 t~ e magneLIC
compass. Lig htning disch a~ges,. eve n d istant ones,
can disrupt radio com murncations 01~ Jo,.v a nd.
medium freq u e ncies. Thoug h light1~ 111 g 1:itens1ty
and freq ue ncy have no simple relationship to o ther
sto rm para meters, se vere storms, as a rule, ha ve a
high fr('quen cy of ligh tning.
Weather radar
Weather radar detects droplets or p1·ecipitatio n size.
Strength or the rad ar return (echo) depends on
drop size and number. The greater the number of
drops, the stronger the echo; and th~ larger th~
drops, the stronger the ech o. Drop size detcnrnnes
echo intensity Lo a much greater extent than do_cs
drop n u mber. Hailstones are usually cover ed with a
film or wa te1· and , therefore, act as huge water
droplets gi ving the strongest of all ~choes . . .
Individual thunderstorm cells build and d1ss1patc
rapid ly. The1·efore, do nol attempt to plan a course
between cell echoes. The best use of ground radar
information is to isolate general areas and coverage
of echoes. You must avoid individ ual storms from
in-flig h t observations e ithe r by vi~ u al sighting or by
airborne radar. I t is better to avoid th e whole
thunderstorm area than to d etour ar ound
individual storms unless they are scattered.
Air borne weather avoidance radar is, as its name
implies, for avoidi ng seve1·e weathe r - . not for
penetrating it. Whether or not yo':1 fl y u.1to an a:ea
of radar echoes depend s on echo 111Lens1ty, spacm g
between the echoes a nd the capabilities of you and
yo ur aircraft. Remember that weather radar detects
only precipitation drops; it does not detect .
turbulence. Therefore, th e radar scope provides no
ass urance of avoiding turbu lence. T he rad ar scope
also does not provide assu rance of avoiding
instrument weather from cloud s and fog. Yo ur
scope may be clear between .intense echoes; th is
clear area does not necessanly mea n you can fl y
between the storms a nd main tain visual sighting of
th em.
The mos r intense echoes are extrem e
thunderstor ms. Remember that while hail always
gives a r adar echo, it may fall several kilometres
from the nearest visible cloud and haza r dous
turbulence may extend lo as much as 30 km fro m
the ech o edge. Avoid Lhe most intense ech oes by at
least 30 km: that is, echoes should be separated by
at least 60 km before you fl y between them. . .
Airborne radar is a valuabl e tool. H owever , 1t is
principall y an indicator of storm location s fo r
avoidance purposes.
Do's and don'ts of thunderstorm flying
Above all, remember this: never regar d an y
thu nderstorm lightly eve n when r adar obser vers
report the echoes ar e of ligh t intensity. Avoidi ng
thunderstorms is the best policy. Following are
some do's and d on'ts of th under storm avoidance :
• Do plan a n alternati ve ro u te, befor·e becomi ng
airborne, if thu nderstorms are fo recast. Pla nning
will be far more ratio nal in the calm of the
briefi ng office tha n in flight when confronted by
th e proble m. Be p re pared to divert before the
thunderstorms become un avoida ble.
• Don't land or take off in the face of a n
a pp roaching thu nderstorm. A sudden gust fro nt
of low level turbule nce cou ld cause loss of
control.
• Don't atte mpt Lo fl y under a thund ers torm eve n
if you ca n sec throug h to th e othe r side.
Aviation Safety Digest 108 I 11
�T urbulence a nd wind sh ear under the storm
could be d isastrous.
• Do n 't fl y without airbo rn e rad ar into a clo ud
mass containing scallered embedded
thunde rstorms. Scattered thunderstorms not
e mbedded usually can be visuall y
circumna vigated.
• Don 't trust the visual appearance as a relia ble
indicato r of turbu le nce inside a thunderstorm.
• Do avoid by at least 30 km any thunderstorm
identified as severe or giving an intense radar
echo.
• Do circumnavigate the e ntire area if the area has
five oktas or more thunderstorm coverage.
• Do remember that vivid and frequent lightning
indicates the proba bility of a severe
thunderstorm.
• Do regard as extremely hazardous any
thunderstorm with tops 35 OOO feet or higher
whether the top is visuall y sighted or determined
by radar.
If you cannot avoid pe netrating a thunderstorm ,
follo wing are some do's before entering the storm:
• Tigh ten your seat belt, put on your shoulder
harness if you have one , and secure all loose
objects.
• Plan and hold your h eadin g to take you through
the storm in a mini mum time.
• To avoid the most critical icing, establish a
penetration altitude below the freezing level or
above the level o f minus 15 d egrees Celsius.
• Verify that pitot heat is on and select carbure ttor
heat or turbine-engi n e anti-ice . Icing can be rapid
at an y a ltitude and cause almost instantaneous
power failure and/ or loss of airspeed ind ication.
• Configure your aircraft fo r turbule nce
pene tration using power settings and airsp eed
recommended in you r a ircraf"t ma nual.
• T urn up cock pit ligh ts to high est intensity to
lessen tem porary blind n ess from lightnin g.
• ff u sin g automatic pilot, d isengage altitud e-hold
mode and speed-hold mode. The auto matic
altitude and speed controls will increase
ma noeuvres of the a ircraft thus increasin g th e
li kel ihood o f structural stress .
• If using airborne rada r, til t the a nten na u p a nd
down occasionally. Thi s wi ll permit you to d etect
other thu nderstorm activity at altitudes other
tha n th e one being flow n.
Following are some do's and d on'Ls during the
thu nderstorm penetra tion :
• Do keep your eyes on your instr uments. Looking
outside the cockpit ca n increase danger of
te mporary blindness fro m ligh tni ng.
• Don't cha nge power setti ngs; maintain settings
for the recommended tu rb ulence p enetration
airspeed.
• Do maintain a constan t a ttitude; let the aircr aft
'r ide the waves' . Manoeu vres in tr ying to maintain
constan t altitude increase stress on the a ircraft.
• Don't turn back once you a re in the
th u nderstorm. A straigh t cou rse thn m gh th e
storm most like ly will get yo u ou t of the ha7.arcls
in the shor test time . I n addition , tu rn ing
manoeu vr es increase stress on the aircraft.
This article app lies Lo all aircra ft operations. T he
main d iffere nce between VFR and IFR is that the
non-rated pilot on a VFR flight m ust avoid
thunderstorms al all costs. A p roperly rated pilot of
an !FR-equipped aircraft should only consider
penetrating thunde rstorms wh en alte rn a tive action
is not a va ilable, a nd the n o nly >vith ex tre me cau tion
and adequate p re paration •
Pilot contribution
Aviation Safety Digest I 02 conta ined an article
e ntitled 'Programmed Mind' which reminded me of
an error I once made as a result of similar
programming. Although the incid ent occurred
some time ago while I wa s a military pilot, the
lesson learnt applies just a s read il y to civil aviation.
I wa s to carry out a n instrument tra ining flight in
a Doug las Skyhawk from m y home base at N owra
to Williamtown RAAF Base. I had planned to cru ise
at Flight Level 2 10 a nd carry out a T ACAN
approach at Williamtown followed by several touchand-go landings prior to returnin g to Nowra .
At Nowra, the wind was blowing quite stron gly
from the west, as it is wont to d o the greater p a rt of
the ye a r, and the duty run wa y was 26. I d eparte d
Nowra, climbed to FL2 l 0 a 11d p roceed ed to
Williamtown. On first contact with Williamtown
Approach , the controller gave me the landin g
information, then rad ar vecto red me to the Initia l
Approach Fix. T he Initial Approach Fix fo r a
TACAN approach to e ithe r run way 12 or 30 a t
William town was at the same position to the
south-west o f the field , and the pilot simply turned
left o r r igh t as a ppropria te and followed a DMF. a rc
12 I Aviation Safety Digest 108
until intercepting fin a l app roach to either ru n way.
Conseque ntly I turned r ight the n followed the a rc
to the le ft until a ligned on fin al for run way 30.
The a pproach controller , who had said nothi ng,
handed me off to the tower, a nd o n contact with
the tower I was initially bewildered when I was
instructed to break r ight and j oin downw1nd fo r the
duty run way 12. You can imagine m y acute
embarrassmen t wh en I realized I had made an
approach to the reciprocal r un way, as I h ad
programmed m yself to th inking that the wind
would be blowing from the west at Willia m t.own . In
fact it wa s blowing f"rom the south-east, a nd in what
had been a relatively shor t trip of about 20 minutes,
m y mind did not register the fact th at th e wi nd
might be blowing fro m a no ther d irection , and I
obvio usly did not p ay much a tten tion to the la nd ing
inform ation.
I offe red p ro Cuse apologies to the RAAF
controllers, whom I a m su re were smirkin g be hi nd
their microphones, cancelled an y thou gh t of toucha nd-go la ndin gs and high-tailed it for Nowra. I now
listen a ttentively to th e AT l S •
Fuel contamination
After landing a t a mi ning airstrip in Western
Austra lia , the pilot of a Mitsubishi MU -2 arra nged
fo r the refu e ller to ad d th ree 200 litre dru ms of Jet
A- 1 fu el to the a ircra ft's ta nks
T h e refu eller rolled three fuel d ru ms out to th e
a ircraft and stood one at each wing tip a nd the
other near the nose. H e then unsealed th e two
d rums a t the wing tips and pum ped their conte n ts
into each tip ta nk. Meanwhile, the pilot h ad been
u nloading the aircraf"t a nd when he had finished ,
he broke th e seal and rem oved the bung on th e
th ird dru m a nd , using a por table hand-operated
rotary p ump carried in the aircra ft, pumped th e
conte nts into the cen tre ta nk . About 20 m inutes
a fte r the re fuell ing operation had been completed,
the p ilot too k a n opaque plastic coffee cup and
d rai ned fro m each wing tip fu el ta nk a small sample
of liq uid which he visually insp ected, smelled ,
identified as the correct fuel and th en threw on th e
gro und . The fu el d rums were re-bun ged a nd rolled
awa y to the sid e or the parking bay.
A short time later, wi th seve n passe ngers on
boa rd, the aircraft took off and wh ile o n climb
th rough about 8000 fee t the p ilot bega n
transferri ng fuel fro m the ti p ta nks to the centre
tank. As th e aircraft a pproached 12 OOO fee t, th e
p ilot noticed a d rop in torque a nd EGT fo r the left
engi ne a nd , as he tried to identify the malfunction ,
h e noticed a simila r power drop in the r ight e ngine.
A trouble ch eck and routine corrective action had
no effect so the pilot d ecided to land at another
aerodrome and establish the cause of the problem .
H e had just begun to d ivert however , when both
engin es rapidly lost power a nd fi nall y fla med out.
T h e pilot atte mpted a relig ht bu t was u nsucce ssful.
The aircraft. was ove r flat, spinifcx-cover ed dese n
co un try a bout 128 km fro m th e d eparture airs tr ip.
T he pilot briefed the p assengers to prepare for a
fo rced land ing, tra nsmitted a Mayday call and
successfu lly put the aircraft clown between two lo ng,
parall el six metre high sand dunes. Apart fro m
slight buckling of the nose wheel d oors, th e aircraft
was undamaged and none of the occupa nts was
injured .
Subsequen t checks of the aircraft's fuel system a t
the fo rced landing site a nd the d rums from which
the aircraft was refu elled sh owed th at the fu el was
heavily conta minated with water. A visua l check of
th e con tents of th e left tip ta n k revealed about 160
to 180 liu·es o f clea r water with a layer of fu el about
I 0 mm d eep lying 0 11 top . Sam ples o f liqu id fro m
th e righ t tip ta nk appeared to be a 50/ 50 mix ture
of water and l"uel , wh ile th e centre ta nk con tained
about 35 per cent water and 65 p er cent fu el. T he
fuel lines to the e ngi nes contained mostl y wate r
with some l"uel globules.
Samples of the liq uid remaining i11 the three
drums used to refuel the a ircrart showed var ying
m ixtu res of water and fuel. T he liqu id in one d ru m
consisted or clean , fresh water lightly con tami nated
with fu e l, another con tained approx imately 50 per
cent wate r a nd 50 per cent f ue l and the third dru m,
which was pro bably used to re fuel the cen tre ta nk ,
contained only .J et A- 1. Other scaled 200 litre
d r ums from the sa me stock were opened a nd also
Aviation Safety Dig est 108 I 13
�found to be contaminated wi rh water i11 va n ous
amounts.
Samples of the wate r obtained from the aircraft.
and the fuel drums were subjected to laboratory
anal ysis and after comparison with several other
samples, it was determin ed that the wa ter in the
drums had come from a ground \Vale r bore a shon
distance from the town ser ved by the airstrip. Fuel
compan y documentation s ho1Vcd that the co nte nts
or· the drums met all the presc ribed quality control
requi rements prior to their deli ver y to this location.
All the drums in which water was found
appeared Lo co11tai11 a total quantity of liquid close
to the 200 litres which was supposed to be in the m.
The y 1Vcre neithe r over nor under fill ed and,
before the y were opened to refuel the aircraft, all
drums appare n tly h ad t he seals intact. The water
could not have been in the drums accid e nta ll y
because , in one case at least, some fuel must have
been removed , a similar quantity of water p laced in
the drum and the drum then resealed.
It was not possible to determine how. why and by
whom the wa ter was placed in the 'scaled' drums or
J ct A-1. Certainly, tht: p ilot 11·as not expecting to
find \\later in either the chums or the aircraft's
tanks, but h is quali ty control checks ll'ere cursory in
th e extreme. J ct A- I is colou r less and the presence
of wa ter may be difficult Lo detcel u nless th e proper
rel"ucllin g procedu re is followed and
water-detecting aids are used. But no checks for
co nta111inants were carried on1 before reruellin g
commenced. no filt ration cquiprnern or
wate r-detecti11g a ids wer e used at any stage, and the
checks th e pilo t made after refuelling had been
comple1 ed ll'ere tota ll y inadequate Lo cleLecL the
presence o r· water in th e fuel.
The circumstances or th is accident are unusual in
that no pilot, maintenance eugineer, or refuelle1·
would normally expect LO fi11d water in such large
quantities as were p resent on 1his occasion .
levertheless, the p recautions to be takeu during
re foclli11 g, especiall y wht>n using d rum srocks, a re
<)cscribecl iu detail in Ai r Navigation Order 20.:l
and their adoption in this i11sLa11ce wou ld have
cusurcd LhaL co11tami11a recl fuel was nor pumped
inro rhe aircrafr's ranks•
t
Carburettor icing
(Refer to lift-out probability chart in centre section)
To assist r eaders 10 better understand the na1ure o r
carburettor icing. the Aviatio11 Srtfl'fy D ig1'sf rece ntl y
publish ed tlVO articles 011 this s u~jcc L. I11clucled in
no. I 03 was a dia g ra m which enabled pilors Lo
anticipate ice formation but required them to obtai11
a d ew point figure. This figu re is readil y ava ilabl e to
pilots at brie fing offices with a me teorolog ical
onicer o n duty. but not elsewh ere. To overcome
this difficulty anorher chart, using the \\·et and dry
bulb temperatures or a give n air mass ro predict the
probability or carburettor iciug. has been prepared
and is enclosed as a lirt-011t ce nrre sectio n in this
ISSUe.
T o obta in the temperatures the correct
equipment is necessary and may be purchased from
any scic utific instrum en t compan y. The cheapest
fixed installation ma y be obtained for less 1ha11 20
dollars and a portabie type costs und er 40 dollar s.
·w hile thi s expense may be umrarranted for
indi vidua l pilots o r aircraft owne1·s, aero clubs and
fl yin g schools may fi nd th e cquiprncut a valuable
teachin g aid when used in co11ju11ctio11 with the
enclosed lift-out chan. Also, co11scinnious pilo ts will
be a ble Lo anticipate carburettor ice fo rmation by
using th e equipme n1 a nd consulting the ch a rt prio r
lo f1igh r.
' J"he major ca use of carbure uor ice is the
temperature drop of up to 40 d egrees Celsius
res ultin g from the evapora ti on of ruel , particularly
from m etal surfaces. A second cause is the
te mpe rature drop resulting from the expansion of
the air/ fuel mix ture a t the thro1Lle butterlly; this
14 I Aviation Safety Digest 108
effccl is sma ll at high power but ca11 be u p to 10
d egr ees Celsius at a p proach an d idle p oll'er settin gs.
Refe1·ence Lo the li f"t-out char! sholl'S the ll' id e
ra11gc or· ambient co nditions cond ucive lo t he
format ion of carburettor ice in a 1ypical light
aircraft cngiue . ote p articu larly the cxte11Lof the
risk of" serious icing 11ncler descenr poll'Cr. \\·hich
incl ud es sunHne r tcmpcralu res unde r hum id
conditions.
\i\'h y then arc the re not more cases of carburettor
icing?
The a nswe1· is that engine man u f"actu r e rs h ave
long rccoguisecl Lhe pro ble n1 a nd modern
rcciproca6ng ae ro-engines are des ig ned to minimise
the ir susce ptibility lo icing. Features such as intake
m anifolds cast integral! )' wirh the engine sump a nd
the bolting of ca rburettors direct 10 1be sum p
no rmally provide su bsra ntial p rorecrion. H o"·eyer,
this is e ffecti ve on ly wh ile the engine is hot. Adding
the fuel to the air just before the inlet va lve as in
fu el injection e ngines provides practica ll y full
prot:ectio n , although stil l 11·ith some susceptibilit y Lo
throttle iciug at redu ced p cmel'.
Remember tha t loll' po11·er operat ions arc most
conducive to ici11g because or Lhc double effect or
("u d evaporation and a irflow thro1tling; ex tend ed
I01r power/ low tempera t u re operatio ns at cruise
alri rudes ma y lower e ng in e temperatures into the
vu lnerable range. A ractor of"Len forgotten is that
cruise just below cloud will a lso be in very moist air,
close to t he saturation level •
f
1
�30 .
Carburettor icing - probability chart To use the chart
- Obtain the wet and dry bulb temperatures
26
- Enter the chart with the wet and dry bulb
temperatures
- Refer to the shading legend appropriate to the
intersection of the temperature lines
- From the intersection of the temperature lines,
obtain the relative humidity on the curved scale,
and the humidity ratio from the right hand scale
Example shown on chart
-Wet bulb temperature 14°C
CLOUD, FOG & MIST
ABOVE THIS UNE
- Dry bulb temperature 18°C
- From intersection of the temperature lines the
shading legend gives, 'moderate icing - cruise
power, serious icing - descent power'
~••••~71--r sHUMIDITY
1
]')
- Relative humidity 65 per cent
16
- Humidity ratio 8.5 gm water per kg air
RATIO
rnm#f#~t#±f:f:§lH~--T14
gm water
ffifffi&@RSS~H--+--+12
SERIOUS ICING-ANY POWER.
10
~%~¥~iff.ft&% MODERATE ICING-CRUISE POWER OR
~t~1!lf~~~0% SERIOUS ICING-DESCENT POWER.
1 11
1:11
1111111:111:::1 111111:1.11
~~~~~~
kg air
ICING- DESCENT
0
5
10
15
20
25
DRY BULB TEMPERATURE
0
30
35
40
c
Aviation Safety Digest 108
�Wire strikes
/
Many pilots associate accidents involving overhead wires with agricultural flying, not realising how
many of these occur in other general aviation operations. The following article provides advice for the
agricultural pilot and all other general aviation pilots on the problem of wire strikes.
Collisions with overhead wires. or wire strikes,
cont inu e to account for a s ig nificant p roponio n of
accidents in volvin g ge n eral aviatio n aircraft. Table I
shows tha t for the lasl fi ve years an average o r 10
pe r ce11l of ge neral a via tio n acciden ts involved wire
strikes. Surprisingly, the ma jori ty 110 longer occur in
agricu ltural ope r ations. The total number of wire
strikes is increasing, a nd so is th e numbe r suffe re d
by air craft on other th an agTicul tural operations.
}'rar
\\'in· .1/rilw.,
Total g1"111·ral
aviatiou ocridrlilS
t\griwlt 11 ml
1974
1975
197G
1977
1978
25G
208
2-13
22 1
2.'">0
Other
l '.-1
6
II
8
11
11
17
H
13
17
Table I
In Ma)' I !::17!::1 , a pp roximately 90 delegates,
represe n tin g 70 pe r ce11t of agric ul tural operator s
in Australia, auended the Aerial Agr icultural
Associa tio n of Austra lia Co n ve1llion in Penh.
Among Lhe speake1·s ll'as Mr C. J. Freeman from
the Ge ne ral Aviatio n Bra n ch, De p a n ment of
T ra nspo rt. l\fr Freema n preseuted the folloll' i11 g
paper 011 the proble m of locating and avoiding
po" ·e r Ii n es.
Wh ile the pape r is directed tmranls pilo ts
engaged in agric ultural ope ratious, th e comments
a bo u t loca ting p ower lines would also apply to a n y
gen eral avi aLio11 pilot conducting a p reca u tjonar r
search prio r to landing awa y from an established
aer od rorne.
'Call them wha t you will but without do ubt wires,
hi gh tension lines, cables and Single Wire Earth
Re LU r n lines are probably the g r eatest hazard facin g
Lhe ag ricultural p ilot tod a y, whethe r he is
inexperien ced or highl y exp erienced.
'During the period 1974- 78, wire strikes
accou nted fo r 20 per cent o f agric ultu ral aircraft
accide rHs in wh ich the aircraft was substautially
damaged or destrnred . The)' also accounted ror 40
per cent of all fatalities and 36 per cent of all
serious in juries in agricultural operations, so it ca 11
be seen that the ch ance of s u rviv in g a wire st rike
accident is consiclerabl)' lc me r rh an fo r a n y other
type or agricultural accide nt. l n deed, as 17 per ce nt
of all ll'ire strikes result in fatal injurr a nd 22 per
cen t in ser ious inj ury, a pi lo t in volved in a wi re
strike h as more than one chance in th ree of bei n g
killed o r seriously injured.
'These facts arc quite obvio us to the pilot.
involved in agricul t ural operations an d p anicularly
in spra ying operations , bUL wire strikes contin u e.
Wh y?
' In a rcp reselllative ten wire strikes, two in volved
\\'ires of which the pilot 11·as u nall'arc. 0 11e i11 volved
m isjudgement or wi re cleara11cc and seven - th at is
70 per cent or a ll wire strikes - happe ned wh e n
the pilot fo rgot about a wire he h ad p reviously
located .
Aviation Safety Diges t 108 I 19
�'What can be done to reduce the occurrence or
wire strikes?
Wire location
'During the training of an agricultural pilol greater
e mphasis must be placed on wor king aro und wires,
after locating them from indications given by poles,
insulators, cross trees, buildings and common sense .
The pilot must realise that the indications on their
own are not good enough ; he must locale the actual
wire. If in doubt he must fly over the pole to locate
the wire; he is unlikel y to fl y into the indication.
'The importance of treatme nt a rea inspectio ns
must be stro ngly emphasised . Ground inspections
are of d oubtfu l value in determining pole runs and
wire dispersal, a nd are often impossible. Aerial
inspections are much better, as the perspective is
correct and the chance of a pole being hidden from
sight is less because it is possible to see other poles
in th e run . One proble m with a n ae ria l insp ection is
that, having carried it out, the pilot usuall y begins
treatment immediately and has li ttle Lime to digest
all the information gathered during the inspection.
'The problem of transferring an inspection in
plan to a treatment in elevation is not great, in fact
the inspection is a combination of plan and
e levation.
'The aerial inspection mu st be condu cted with
great thorou ghness, star tin g as th e aircraft
approach es the treatment area a nd continuing o n
into the area. Nothing must be left on the basis of ,
" I think that is where it goes". The pilot must be
I 00 p er cent certain and if he is not, then he must
look again. However he must not fl y around the
area excessively as this could disorientate hi m in
relation lo obstacles. It is also time wasting and time
wasting will eventuall y appl y pressure which could
result in me nta l overload.
'Th e pilot must make proper use of all visua l
clues. T he most obvio us arc the pole runs associated
with the wire run. ll is often possible to locate the
main feed line (particulady with Single Wire Earth
Return li nes) and this, combined with th e
knowledge that dwellings in the area all have power
connected, will give an indication o r the possible
pole and wire ruus. T he type, number and atti tude
o r ins ulators ind icate the wire disposal on the pole,
and if interpreted properly wi ll yield a wealth or
informa tion on wire direction , height, tension and
so o n . Cross trees on the poles indicate
suppleme ntary wire runs a nd the a ngle of the cross
tree, in relation to the main run, will indicate th e
angle of the supple men tar y or spur wire.
'Finally, it can be said th at, as a general rule, in
a n area whe re domestic power suppl y is available,
all dwellings and most other buildings have power
connected. No a ttempt shou ld be made to begin a
treatment until the wires supplying all buildings in
the treatment area have been located.
'Al ways remember, visua l cl ues arc only indimtiuns
of wir e runs; the wire itself must be located.
Misjudgment of wire clearance
'This usua ll y results from o ne o f two facto rs. The
first is that the pilot Lakes avoiding action too la te to
clear a wire. T his may occur al the end of a run or
during a run when there is insufficient clearance to
fl y under the wire.
20 I Aviation Safety Digest 108
'To overcome this problem it is essential that the
pilot select some reference point al which avoiding
action must be commenced in order to provide
adequate clearance of the wi re. Two situations
where use of this tech nique is ad visable are
approachiug a wide span or wire and whe n
approaching a wire that is at an angle Lo the fligh t
path. It can a lso apply when approaching wires
wh ich are at different heights, because the highest
wire a lways looks farthest away.
'The second factor arises when the pilot finds th at
the wire he intended Lo fly unde r is either lower
than he thought or has an obstruction underneat h
it. In respect o f the former, it should be obvious
during the inspection that a wire has either
adequate clearance or suspect cleara nce. These
parameters will va ry as a pilot gains experience.
'When the clearance is suspect the aircraft should
be flo wn at spraying height, parallel to the wire,
and the clearance p hysically checked. The pilot can
then decide wheth er he will fly over or under the
wire during the treatment.
'Obstructions beneath the wire shou ld be located
during inspection. During training strong emphasis
shoul d be placed on inspecting the surface below
the lower le vels of th e wire run for obstructions and
undulations. The fences a longside the sp raying run
are other areas where the pilot is likely to encounter
extra neous bits and pieces of equipment
encroaching upon h is !ligh t path. When a n
obstructio n is located under a wire durin g a
spraying run , it is usuall y a small one, otherwise it
would have been seen during the inspection.
To avoid it, yaw the airc raft and flat turn slightly.
As a last resort hit it (unless it is a human marker).
This is infinitely better th an striking the wire.
T here is little other than wires, large trees or new
fences tha t wi ll stop a n a ircraft, and stayi ng
airbo rne with a wheel, undercarriage leg or spray
pump removed is preferable to hittin g the gro und
hard with the aircraft in one piece.
Strikes on 'forgotten' wires
'This problem involves the h ighest proportion of
strikes, deaths a n d serious injuries, yet is the
hardest to solve. Du rin g training the future
agricultural pilot m ust be made aware that one
fata lity in four involves striking a wire that had
alread y been located. While it is essential to locate
wires, it is even more important to remember them.
The only way lo remembe r a wire is to dism iss all
extraneous matte r from yotff mind while engaged
in treating an area a nd concentrate on the job in
hand. Easily said but h ard to practise, particularly
when the chemical o r avgas that you expected in
half a n hour wi ll not be available for anothe r row·
hours. But it is extremely important, a nd new
minds can be trained to do it. The budding
agricultural pilot can also be trained to carry out an
extra "wires" or "obstructions" check before
carrying oul clean- up runs. T his is the mai n area of
wi re strikes and resu lts fro m relaxation or mental
overload, and these two factors can go
hand-in-hand with orientation of the treatment area
a nd obstructions changing through 90 degrees. The
RAAF carry out an extra "wheels" check on [Ina!
approach. Maybe a verbal "wires" check would be a
professional a pproach to this problem.
'We are losing experienced pilots as well as new
men. Most industry p ilots would be aware of a
number of highly experienced pilots, with many
years in the industry, who have lost their lives
through wire stri kes over the past few years. The
ind ustry cannot afford to lose men of such calibre
and experience. Some have struck wires and
survived; many oth ers have come perilously close to
wires they had forgotten about. Remembe r, it can
happen to yo u even though you have many years
and thousands of hours of experience.
'The problem of mental overload is uppermost in
the case of the ex perienced pilot. Individuals vary
as to the mental load they can tolerate but all must
reach saturation at some time and the addition of
one more factor will drop some items out of thei r
memory. These items will not necessarily be
unimportant ones. To avoid th is possibility, pilots
must be encouraged to relegate items that do not
require their full attention. They must also train
themselves to dismiss from their heads all
extraneous matters that do not relate to the actual
job in hand . T hey can reduce thei r mental load by
better planning; a properly planned operation
reduces the need to carry a heavy mental load. A
note pad in the cockpit to jot down items that need
to be acted upon at the next landing could reduce
this load a nd accordingly the chance of overlooking
a wire.
' I n addition, loader drivers could be trained to
accept more responsibility, thus reducing the pilot's
men tal load and ensu r ing that his approac h to the
j ob is a little mo re relaxed. The solution is therefore
twofold: reduction of extraneous loading on the
pilot by better planning, and training or auxiliary
staff.
'Pilots must realise that their biggest hazard is
distraction. I t is imperative that they dismiss from
their minds all items not associated with the actual
treatment. The bullet can't kill you unless someone
pulls the trigger: in this case the wire is the bullet,
and the distraction is the pull on the trigger.
'The causes of distraction are all too well known
- chemical not available, avgas not turned up,
more work coming in, leaking nozzles, tonight's
accom modation, last night's row with your wife or
girlfriend, et cetera. The owner/ pilot is at the
greatest risk for he has business pressures to
contend with as well. I t is essential that yo u dismiss
these problems until you have landed, when they
can be handled without the distraction of having to
fly an aircraft as well .
Familiarity
'One last factor is familiarity. No pilot of sound
mind feels conte mpt fo r wires, but it is possible for
him to become Loo familiar with them and feel less
concern than is healthy. Unfortunately, after the
battle with the wires in and around the treatment
area has been won, they do not fall down or
disappear. They stay there and wait - and the war
goes on.
To sum up, I am advocating:
-More emphasis on training new pilots in location
of wires.
-More thorough inspections of areas under, and
close to, wires, particularly where the wire is low.
-The use of supplementary reference points where
it is difficult to pinpoint the position of the wire.
-Extra checks before clean-up runs.
-Above all, awareness that distraction from the job
in hand resulting from mental overload causes
wire strikes with more than one chance in three
of death or serious injury.
- Delegation of more responsibility to loader
drivers.
Aviation Safety Digest 108 I 21
�'Do not lei familiarity make you casua l in your
approach to wire location and avoidance. Mainta in
high standards and always have a health y respect
for the potential death-trap of wires.
' In conclusion, it is worth noting that if you hit a
wire a nd you are wea rin g a crash helmet your
c hances of survival arc doubled! '
The non-agricultural pilot and wire strikes
While collisio ns with overhead wires arc a haza rd
assoc iate d with the ver y nature of agricul tura l
fl ying, th e case is different for other kin ds of fl yin g.
T he r e a rc two basic situations wh ich result in wire
strikes by aircraft not engaged in agricultural
operatio ns.
The first is th e complete disregard of Air
Navigation Regulation 133 by th e pilot who engages
in un autho rised low fl ying. These illegal and often
spur-of-the-moment ope1·ations have been
res po nsible for innumerable accide nts since the
earli est days of aviation. The dan ger s in volved have
not changed over the years: if anythin g, th e
like lihood of fl ying into a power line has increased.
Overhead wires are now found all over the
co untry, a nd are not confined to areas of
habitatio n. T he y criss-cross th e land sca pe, and va ry
in size and shape from large multi-cable
tra ns mission lines on steel towers to innocuous
s ing le-ca ble power lines on wooden po les.
Transmissio n lines often span valleys from hilltop to
hilltop and may be up to 400 feel a bove th e va lley
floor. Sing le wire lines, thoug h usual ly on ly about
30 feet above th e ground, ofte n have extremely
long s pans, up to 300 metres betwee n poles. In
these days of e n vironmental awar eness, the
a uth orities usuall y position poles to be as
inconspicuous as possible, quite often hidde n
am o ngst trees.
T he ne t result is that overhead wi res a rc
extre m ely hard to see, especially for the p ilo t of a
low flying aircraft who is not o n th e look-out fo r
them.
Before desce nding below 500 feet AGL conside r
th e r is k to your aircraft an d passengers of e ngaging
in this unauthorised activity. There is o nl y one
solutio n - don't do it!
The second situation wh ich r es ults in collisio ns
with overhead wires involves aircraft la ndin g and
taking off. Government a nd licen sed ae rod rom es
are listed in AIP AGA which includes th e
obstruction-clear gradient o f the ta ke-off climb
surface from the encl of each flight strip.
These gradie nts' take accoun t of obstructions
inside the standa rd splays. Quite often th ese
g r adien ts a re less than o ne in 50 but o nl )' ra rely as
sleep as one in 20. A pilo t knows tha t if he
maintains at least th e listed gradient he wi ll not
encounter a n y obstructio ns, includin g wires, during
take-o ff or landing. However , a long, flat approac h
be low the listed g r adie1it, or a loss of e ngin e power
a fte r take-off co ul d res ult in a wire strike.
Authorised Landing Areas (ALAs) prese nt a
majo r proble m for aircraft du r ing take-off a nd
landin g. In this situation the pilot must en s ure that
the physical dimensions and characteristics of" th e
a rea m eet the require me nts specified in 1h c AI P
22 I Aviation Safety Digest 108
and the VFG. The ma xirnun1 pc nuittc d
obstruction-free landin g a11cl take-off g radients are
one in 20 for da y operatio ns a nd one in 30 for
night operations. If a pilot 11or111ally operates from
a govern ment or lice nsed aerodrome, the one in 20
gradien t al an ALA is slee pe r th an he is accustomed
to. T herefore , a lthough an obstruction may not
penetrate this g rad ient it cou ld sti ll constitute a
hazard to a pilot m aki ng a flat approac h.
A pilot inte nding to use an ALA can no t afford to
assume that th e re are no hidden obstruction s such
as power lin es in th e approach and take-off ar ea
sim p ly because no one h as me ntio ned them. lie
must make every e ndeavo11 r lo asce rtain the
existence or wires or o th er obslructions. This can be
done vis uall y durin g a ground inspection or th e
area, or verball y wh en disc ussing the use of the area
with the owner, occupier or con tro ll ing authority.
Having take n the necessary actio ns pre-flight, the
p ilot's next o pportunity for sa feguarding aga inst a
possible wire strike will be during his precautionary
search prior to landing. If the re are no major
transmission lines in the area it will be sa fe lo
d escend below 500 feet AGL. Us in g th e techniques
mentioned ea rlier in this a nicle, the pilot can locate
any indications of" wire runs ancl then locate the
wire itself. In consideration o f the ave r age height or
power lines, th e re is no need for this inspection to
be cond ucted at less than 150 feet AGL. Once the
pilot is assu red that he has located any wires, and
he is completely satisfied the y do not comprise a
hazard to hi s inte nded operation, he can d escend
f"urth er for the landing.
If, prior to take-off, a pilot considers that an
overhead wire ma)' present a proble m in tJ1e e vent
of a loss of engine power he should consider the
use of a n a lternative take-off direction that will
ove rcome the hazard.
T he use of fi xed-wing and rotary-wing
amphibious aircraft is increasin g in popularity.
Associated with the increasing popularity is an
increasing rate of wire strike accidents. There are
numero us lakes, reservoirs and wa terways in
Australia th at would be suitable for these o perations
except th at power lines are strun g ac ross them with
the poles hidden above th e s hore line. With a
backgrou nd of wa te r these lines are ex tremely hard
to see. Pilots intendin g to use a waterway, for th e
first time particula rl y, sho uld be ex ti·e mely vig ila nt.
Do not be misled in to believin g that a power line
stops at th e shore because you cannot see the wires
across th e wa ter way. Make the extr a e ffort needed
to be positive that there are no wires above the
wate rway.
The likelihood that an a ircraft fl ying close to th e
gro und will encoun1e1· overhead wires is g r owing
consistentl y; th e on ly safe co u rse is to expect th at
wires will be a hazard in an)' operation in vol vin g
low flig ht. Be sure to La ke th e necessary precautio ns
to avoid th em. In th e wo rds o f" Mr Freeman: ' I
believe the wire strike p roble m is now extreme. rr
an average pilot set out to fly for o ne hour, in a
straight line, over a rura l a rea , at 25 feet AG L, he
wo ul d fl y in to a wi re befo re th e ho ur was up, no
matter how vigilant his look-out. For this pilot Lhe
o nl y safe place, in a n aircra ft below 500 fee t in such
an a rea , is statio nary on the ~rou nd !•
Passenger evacuation briefing in
general aviation
Two unrelated and quite differ e nt accidents in Lhe
U nited States a fe w years ago promote a com mon
!lig ht safety lesson. In the first accide nt, a DC I 0
aborted a take-off foll owing a bird-strike which
cau sed an engine to ex plod e. The la ndi ng gear
colla psed a nd the aircraft cau g hl fire. All o f th e 128
occupants escaped quickl y wi thout serious injury:
the passenger s were airline employees and most o r
th em wer e familiar with evacuatio n procedures. In
th e second accident, exactly 12 m o nths later, nine
passengers involved in the cr ash of a Falcon 20
experie nced 'severe diffi cu lties' evacuating th e
ai rcraft because they had not been briefed on the
rclevanl procedures be fore departure.
Furthermore, there were no placarded instructio ns
fo r o pe ning the main ca bin door or the two
o ver wi ng exits. FortunaLe ly. the re was no resulta nt
fire a nd all passengers eventuall y escaped.
Both these accide nts indicate th e importance of a
conscie ntious passe nger evacuation brie fin g a nd th e
lesson is just as importa nt to the ge neral aviatio n
pilo t as it is co the airline capta in , particu larl y with
the increasing passenger-carr ying ca pacity a nd
complexity of modern general aviation airc raft. But
rather than a ttach a com placency tag to the ge neral
avia ti on operator who fails to brief his passenge rs
adeq uately, funhcr consid eration of the matter is
warran ted for there may perhaps be othe r
subconscious factor s involved.
Firstly, in this techn o logical age, it is a ll loo easy
to ass um e th at passengers will auto matically kn ow
h ow to open ca bin doors and e m erge ncy ex its.
After all , o ne mig ht say, th ey have o nl y to read the
p laca rds. But how often have p asse ngers r equired
assistance to eve n unlock their seat belts after a
norma l flight? In the added shock a nd confu sion of
an emergency evacuation, even the simplest task can
become difficult. Pressurised cabins have add ed
weig ht LO doors and hatches a nd complexity to their
locking m ech anism s, and placards may not be
readily seen in a n emergen cy night landi ng.
Secondly, in most general aviation commer cial
operatio ns, the pilot generally identifies himself"
closely with the passengers. H e may have assisted
with the luggage handling, h e probably closed the
cabin door and almost certainl y brushed past the m
on the way to his seat. H e senses that in the e ve nt
of a crash landing, he will immediately be 011 ha nd
to direct th e evacuation . But th e re is no g uara nlcf'
that the pilo t, particularl y in single pilot o peratio ns.
may not be full y occupied in securing the a ircraft o r
making radio transmissions. He may be
incapacitated a nd relying on his passe ngers to no t
o nl y l"cnd for themselves but also to assist him lo
leave the aircraft.
Thirdly, th ere is ofte n th e th ought that a
comprehe nsive e merge ncy brief may put unplcasanl
doubts into the passengers' minds, particularly
when g iven by the pilot rath er than a g lam orous
cabin atte ndant making the evacuatio n brief a
slig htl y easier pill to swallow. However, a short but
appropriate ex planation of evacuation procedures
will not only play a major role in the success of a n y
evacuation but can a lso assist in removing an y
feelings of underconfide nce a mo ngs t passenger s
perhaps travelling in a lig ht aircraft for the first
time.
The length of th e brief a nd the man ne 1· in wh ich
it is p resented arc naturall y as important as the
information given. Prior Lo a departure, coverage of
the evacuation procedu re in th e pilot's brief need
include little more than an indicatio n o f the p osition
and operation of the no rm al and e mer gency exits,
and alte ntion drawn to passenger briefing cards if
required to be carried o n the aircraft.
Conversely, a passe nge r brie f" prior to a planned
emergency landing with a jammed und ercarriage or
a forced landing witho ut power can be much more
specific and directly re lated Lo the circumstances
a nd passengers on board. Additio nal consid eration
can be g iven to th e particu la r requirements of
ind ividuals, particularly children or hand ica pped
people. Specific instructio ns o n th e location of fi rst
aid kits and how and whe n e mergency exits arc to
be o pened can be given if Lime permits, and
passengers can be briefed against the subconscious
human reaction to leave throug h the door th ey
u sed on e ntering even wh en this exit is blocked by
fire or d e bris or is jammed . Advice m ay be give n o n
other important factors such as the need to remain
seated until the aircraft com es to rest and then to
move quickly without panic until well dear of the
aircraft.
An accurate and confid ent emergency brief can
o nl y be given if the general aviation pilo t has been
properly tra ined and re ma ins thoroughl y
con ve rsa nt with evacuatio n procedures as required
by ANO 20.1 J. In th e unfortunate event that an
actual evacuation becomes necessar y, both the crew
and passengers wi ll the n be beuer pre pared
m e ntall y a nd physicall y Lo cope with wh at o therwise
could be a confusing, sLressful a nd potentially
dangerous situatio n •
Aviation Safety Digest 108 I 23
�Vision 3 - night vision
A veteran pilot once remarked that night flying is no different from day flying - it is just that at night
you cannot see anything. Although there is a lot of truth in his statement, you can usually see
something. To compensate for what you cannot see, you need proper instrumentation. To make the
most of your vision at night you need to understand how the eye operates in darkness.
Colour/ Distance/ Day Only
Cones and rods
There are two kinds of light-sensitive nerve endings
at th e back of' your eye; a dual structure of cones
and rods. Cones provide precise vision and colour
differentiatio n ; they are much less sensitive to ligh t
than rods. Rods are much more light sensitive than
cones, but are incapable of precise vision.
The cones, because they need greater intensity of
light to function, are used in day vision . In fact, the
cones stop working a ltogether in semi-d arkn ess.
Millions of these tin y structures are clustered at the
back of the eyeball , directl y behind the pupil. They
not only distinguish colours but p ick up distant
objects as well.
The rods arc concentrated in a r ing around the
cones. Being colour-blind, the y see only in greys
and arc used in peripheral vision during the day that is, they pe rceive objects in motion out of the
corner of the eye. Beca use the rods ca n still
function in light o f' J / 5000 , the intensity at which
the cones cease to function , they are u sed for night
vision. These structures are J 00 OOO times as
sensitive in the dark as they are in sunlight.
However, they do need more time to adjust to
darkness tha n the cones do to bright ligh t. Your
eyes become adapted to su nlight in J 0 second s,
\.\rhereas they need 30 minutes to fu ll y adjust to a
dark night. Bright lights (such as landing lights)
knock out night vision , requiring you to 'night
adapt' a ll over again to regain maximum night
vision.
The fact that the rods are distributed in a band
around the cones and, therefore, do not lie directl y
behind th e pupils, makes 'off centre' viewing
important to the pi lot during night flight. That is ,
night fl ying requires a diffe re nt visual techniqu e to
day flying. You can see an object best during
daylight by lookin g directly at it. At night, however ,
a scanning proced ure is more effecrjve - you will
find after some practice that you can see things
24 I Aviation Safety Digest 108
more clearly and d efinitel y at night by looking
slightly to one side or the m , rather tha n straigh t at
them. If, du ring your attempts to practise the
scanning procedure, you find that your eyes have a
te ndency to swing directly towa rds the target, force
them to swing past it so that the rods o n the
opposite side of the eyeba ll pick up the o~ject.
Rhodopsin
The underl ying factor governing d ark adaptation
sensitivity is the quantity or rhodopsin available in
the back of the eye. Rhod opsin is the
light-capturing substance carried in the rod
receptors of the retina. Whe n light strikes the
retina, the rhod opsin is bleached and must
rege nerate.
It has been estimated that a pilot can expe rie nce
a 30- 50 per cent redu ction in his night vision as a
resu lt or several hours ex posure to bright sunlight,
es pecially in a light-covered e nvironment s uch as
sand, sea or snow. The e ffect is cumulative, a nd
repeated exposure may leave you with poor night
vision for as long as a week.
Recovery norma lly follows simply as a result of
resting the eyes or protecting them from b right
ligh t, but restoration of visual powers is a g radual
process. Don't expect good night vision after a d ay
on the beach or the ski slopes.
In any event, if you a re a pilot who flies at night
occasionally, you will do well to form the habit or
carr ying sunglasses at a ll times and wearing them
whenever the sunlight is strong.
The selection of sunglass lenses is important. The
wearing of neutral density anti-glare glasses with an
average transmission of 15 per cent is
recomm ended . On ly with a true ne utra l fil ter is
colour vision entirel y normal and it has been
d etermined that a lens wi th 15 per cent
transmission is most s ui table for the level of
brigh tness encountered in fl ying.
Hypoxia
11ccds to under concli1ions or relati ve!)' high
illuminatio11. In instrument flight by clay or night
H ypoxia occu r rin g during Oigh1 lias a deleterious
he docs not ha,·e Lo depend upon external vision at
e ffect 011 ni ght ,·ision and f'or this reason pilots arc
all. except in the Lake-off and landing phases when
a~lvi sed 10 use su pplemen tarr oxygen <lu rin g 11igh1
he is no t usually required to depend on seeing low
flights. Some sources state that 1he d ecrease in n ig h t
~ontrast objects. because the ker i1ems of ,
vision is live per ce nt for e\·e1") 2000 f'eet, bet\\·ee n
information are presented in high contrast by
4000 feet a nd 12 OOO feet ahon· sea leYel. It has
self"-illu minatl'd devices, for example pauerns of
been shmrn that a 25 pe r cent impro,·emen t in
ligl1L. H ml'e\'er, in Night VMC, br definition, the
nigh 1 vision occurs al a height of :)000 feet abo\'e
pilot has to be able to navigate b)' visual reference
sea level 11·it h the aclmi11is1ra1ion of oxygen.
to the ground. He must keep clear of cloud or
obstrunions by visua l reference and it is a great
Carbon monoxide (smoking)
advantage to be able 10 make use of the natural
horizon whe never possible.
Excessive carbon monoxide produces the same
Except in fairl)' bright moonlight, the
decreased night visual capability and increased time
ground-referenced na vigation is based largely on
for dark adaptat ion as h ypoxia from increased
recogn izable collcc1 ions of ground lights which are
alt itude.
For exa mple, a fo·e per ce111 blood saturation ll'ith seen in high contrast. H owever , keeping clear of
obstructions 01· cloud rcqui1-es tha1 the object to be
carbon monox ide gi\'es an effect on the visual
avoided must be seen in low contrast under
th reshold equal lo 8000- I 0 OOO feet of altitude.
conditions or verr loll' illumination . The natural
Smoking th ree cigarettes ca n cause a CO saturation
horizon may. and usually does, present a similar
of approx imate!) fou r per cent. Pilo1s should
therefore observe the ·No smoking 11·ithi11 60 metres viell'ing situation .
Since. in these circumstances, the pilot's abilit)· to
of the a ircraft" sign at all times.
see is being pushed LO its limi1. any factor which
Lends Lo impair this performance is highl y
Tinted windscreens
undesirable. One such factor is lowered light
Another precaution is to avoid 1he use of aircrafl
transmission in the 11·inclscrcen, deliberately
11·i1h_ tinted 11·indscreens ll'hcn fl )'ing al n ight.
in troduced b)· 1inring.
particularly O il Night vrvrc operations . This kind of
I r )'OU have a choice of ai rcraft available for yo ur
fl ight, which is usuall y carried o ut in small general
N ig h1 Vl\IC fligh t, increase your odds and select the
aviation aircrah, is the 111os1 critical visual task of a
one ll'ith the clear wi ndscreen. I t ma r jus1 make the
pilot. In visual flig ht b\' clay a pilot can sec 11·hat he
difference•
Pilot contribution
I n respousc lo your request for pilots to relate
experiences which ma r help lo remiud others o r
essential features in maintaining safe flying, I send
)'OU the folloll'ing cautionarr talc.
While reccnth· fl r ing from Penh Lo a coun tn·
centre \\'il h a si1'1glc ai~-strip, I gave an inbouncl call
on the area VHF frequencr at 20 11111 from
destination, specifying destination, distance and
altitude. A few lllinutes later I i1 1tcrccpted a c;ill
fro m another aircrafl operating in tlie circuit at Ill)'
destina1 io11 a nd called him up to repeal my inbound
call , receiving ackncmlcdgcmen 1 from hilll.
As 111 )' course for the aerodro111e \\'as
a pprnx imatcl)' on the base direction for the strip,
descend ed 10 circuit height a nd joined base leg,
g ivin g a radio call m 1 base leg, specify ing the
runway.
After 1urning 0 11 to final approach. my passen ger
drew Ill )' a1 te ntion to anothe r aircraft flying on a
parallel course at the same altiLUde, about 200 feet
to sta rboard. He had obvious!)' bce11 on final
approach LO 1he same ru nwa)'. I kn e\\' that the
aircraft previouslr operating in the circuit was 0 11
the gro un d at th is stage. I contin ued Ill)' approach
a nd landed.
The pilot of the a ircraft with which I had a
relative!)' narrm,· esca pe from collision made a tight
low level circuit and was alread y 011 final approach
as I taxied back along the strip.
After he had landed aud shut down , I
approached him and, in order to bring up the
subject as tactf'ull)' as possible, I apologised for
unwittingly baulking his landing approach. He said
that he had been surprised to see me and that he
had not heard my calls as he had had his radio
turned d own. I said no more, but mentione d the
incident to the organisa tion from whom he had
hired the aircrafl, when I 1·eturned to Pe rth. They
repl ied tha1 he was a charter pilot who h ad seemed
tc~ be. very experienced. Certainly his handling of
his aircraft appeared lo me to be most competent,
skill'ul and expert - much better than m y own
flring skills could hope to he.
There appear to be two major lessons lo be
learned from this incident.
Firstly, if I had becu keeping a proper look-out
on base leg before turning on to fi nals, I should
ha ve seen this aircraft approaching on a collision
cou rse from starboard and I must have given way
to h im.
Secondlr, 110 ma11cr how skilful and experienced
a pilot is, he 111us1 still observe the precaution of
broadcasting his intentions and listening out for
other a ircran when landing a nywhere, even at
relatively remote country strips .
Though these lessons have been stressed in the
Aviation Safety Digest repeatedly in the past, yo u
may feel that a further repetition is well
worth-while •
Aviation Safety Digest 108 I 25
�Boeing 727 descends into the sea
While making a non-precision instrument approach at night to Pensacola Regional Airport, Florida,
USA, a Boeing 727-235 descended into the sea about three nautical miles short of the runway
threshold. Three of the 52 passengers were drowned when the aircraft sank in about 12 feet of water,
but the remaining passengers and the six crew members were rescued by the crew of a tugboat
which happened to be in the vicinity at the time of the accident.
The aircraft departed Mobil e on an IFR flight plan
to Pensacola, cruising at 7000 reel. The ca ptain was
fl ying the aircraft. On contacting the Pensacola
radar controller the aircraft was told that it wo uld
be vect01-ccl for an a irporl surveillance radar (ASR)
approach to runway 25. ASR provides ran ge and
azimuth information to the controller but not
altitude data. At the crew's request, the controller
restated the type of approach and added, 'Pensacola
weather, measured ceiling fou r hundred overcast,
visibility four (miles), fog, haze'. The crew
acknowledged and shortl y afterwards asked the
controller if the ILS for run way 16 was in use.
They were told it had bee n o ut of ser vice for
several month s because of construction on the
run way.
At this point, the 727 was being vectored for the
approach behind a nother jet airliner and the
controller transmitted to bolh aircraft,
' .. . published minimum d escent altitude (MDA)
four eight ze ro (4 80 fee t), missed approach point (is
the) runway th reshold'. The message was
acknowledged only by the oth er aircraft. The
cockpit voice recorder (CVR) transcript from the
727 subsequentl y showed that when the message
was broad cast, the crew was reviewing the ASR
approach to run way 25. T h e first officer (FO)
briefed the captain correctly on the approach
minima a nd the missed approach procedure, and
the caplain acknowledged the briefing.
At 11 miles north-west of the airport, the flig ht
was cleared to desce nd and maintain 1700 fee t and
was advised that a 'Twin Beech ' on a n ASR
approach 'broke out at four hundred and fifty feet
indicated'. The FO remarked that 480 feet was th e
MDA , and that 450 l"eet was ' illegal for that
run way'.
Sh ortly afterwards , th e FO re ported d escending
through 2600 feet ' for sevcnleen hundred (feet)'.
The fli gh t was vectored to a heading of l l 0 d egrees
a nd the caplain began the approach checks. The
descent and in-ra nge ch eck lists had bee n
completed and the before-landing initial check lisl
was begun.
T wo minutes late r the controller told the flig ht it
was six miles north-east of the airport, and the
aircraft was successively turned on to 160 deg rees
and 220 degrees. Th e captain called for 15 degr·ees
of flap and, five seconds later, the lligh t en gineer
reported that the be!o re-landing initial check list
was complete.
Half a minu te later, the crew received a nd
ackno wledged clearance to descend to 1500 !"eel.
T he controller told the 11ig ht it was 'five and
one-half miles from the run way - continue to your
minimum descent altitude'. The crew ac kn owledged
the cleara nce and the llaps we re extended to 25
26 I Aviation Safety Digest 108
degrees. Shortly afte r wards , the controlle r
inslrucLed the fl ight to tu rn o n lo 250 degrees and
lhc lransmission was acknowledged.
When the aircrafl was fou r mil es from the
run way Lhe controller reporlccl that d1e preceding
j cl aircrafL had canied oul a missed app roach. The
crew replied, 'Thank you'. AlmosL immed iately, the
landing gear warni ng h orn sounded a nd four
seconds later, as the aircraft rolled out o n the final
approach heading, the caplain called fo r lhe
landing gear and Lhe landing final check lisl.
In response lo the flight e ngin eer's check list
challenge 'Landing gea r a nd lever', the FO
responded , 'Down, three greens'. Ths; flight
engineer slated, 'Sta nding by on the final flaps'.
These remarks coincided with a tra nsmissio n from
the con lroller that the aircraft was on course and
three a nd a hall" miles from the run way.
Fo ur seconds later , the grou nd p rox imi ty warning
system (GPWS) whooper sounded and th e 'p ull up ,
pull up' voice warni ng began. The GPWS warning
continued for nine second s and during lhis tim e
o nl y two re ma rks appeared on the CVR transcript
- the ca ptain said , 'Did you (get) yo ur lhi ng?', a nd
the FO commented , 'Descent rate's keeping it u p'.
The fli ght e ngineer acLivated the inhibit switch or
lhe GPWS in response to wh at he believed was the
ca ptain's command to tu rn the system off. Seve ra l
seconds aher lhe warn ing ceased , the .FO called,
' ... we' re down lo fi fty feet' a nd two seconds late r
the aircraft hit the water.
Investigation
Aircraft performance
A flight data recorder (FDR) readout was made o r
the fin al seven minutes 22 seconds of Lhe !l ight .
The last I 0 minutes of the CVR tape we re
transcribed .
Examination of this in for malion revealed that th e
d escent rate was less than I OOO feet per minu te
un til passing through 1300 feet, whe n it increased
LO about 1500 feet per minule. Al 500 reef the ra te
increased to 2000 feet per minute a nd at 300 feet
began Lo decrease again to a bout 1250 feet per
minule . lt re main ed at that value over the last 100
feet of the descent. T he GPWS activaLed at about
500 fee t - almost coincident with the maximum
d escent rate - and ceased at abou t 250 feet.
During the descent from l 700 feet, the indi cated
airspeed was between 150 a n d 160 knots IAS u ntil
the aircraft reach ed 600 fee t, when it started Lo
decrease. T he last recorded airspeed was 138 knols
I AS.
The fina l descent from 1700 feet was begun with
the la nding gear retrac ted and the flaps extended
to 15 degrees and wi th a thrust reduction to 25 p er
cent of ta ke-off rated thrust. This was main lained
until about 1400 feet when the flaps were extended
to 25 degrees. Over lhe next 21 seconds the thrust
was reduced , reaching 12.5 per cent al 1250 feet.
Thrust stayed at 12 .5 per cenl for aboul n ine
seconds Lhen reduced lo flight idle. At 940 feet,
when the land ing gear was extended , the thr ust had
reached flight idle and it r emained there during the
final 35 seconds of Oigh L.
T h e pitch attitude trace showed iliat the aircrafl
descended from 1700 feet to 1500 feet at an
attitude of abo ut three degrees nose up. Shortly
after leaving 1500 feet the llaps were extended Lo
25 degrees, and from that point down to 1300 feet
the attitude decreased to abour zero degrees. At
abou l 1250 feet d1e nose of ilie aircraft was lowered
to three degrees nose clown, and this attitude was
maintained clown to 500 feet. At 500 feet, almost
sim ultaneous wid1 the CPWS warning, the pitch
aLlitucle lowered Lo fou r degrees nose clown and
remained there until about two seconds before the
CPWS warning stopped. At this time the nose of
the aircraft was raised, and over the last 10 seconds
th e pitch attitude increased to about 0 .5 degrees
nose up at impact.
A TC procedures
The prescribed ASR procedures for lhis airport
stale that the linal approach fixes arc five miles
from the thresholds of all runways, the minimum
altitude at the fixes is 1500 feet, and descent to the
MDA begins at the final approach fix (FAF).
The a pproach gate is defined as 'the point on the
linal approach course which is one mile from the
final approach fix on th e side away from the airport
or five miles from the land ing threshold, wh ichever
is fart her from the landing threshold . . .'. The
approach gate fo r run wa)' 25 was six miles fro m its
threshold.
The controller is required to vector ar riving
a ircra ft to intercept the final approach course at
least two miles outside the approach gate and at an
al titude which will allo w descent in accordance with
Lhe p ublished procedure for a non-precision
app roach. Based on these r eq ui rements, the interCPjJt
jJoint on th e fina l approach course to ru nway 25 is
e ight miles from the threshold. The controller is
also required to give 'ad vance notice of where
descent will begin and issue the straight-in MDA
prior to issuin g final descent for the approaches'.
The aircraft was a bout fi ve miles from the
ru nway before the controller issued the turn on to
the linal approach heading. The controller said he
knew th e turn on to linal was less than eight miles
from the r u n way and that it was not as far out as he
would have liked, but that he never doubted the
safety of the ap proach.
The controller also fu rn ished the fligh t with six
position reports; the fi rst two based on the distance
of the aircraft fro m th e ai r·port, a nd the last fou r on
its disLance from the runwa y.
The controller knew he was required to give the
pilot advance notice of the descent point, but as the
a ircra ft was alread y d escending, and as he had
cleared it to d escend to the MDA before it reached
Lhe descent point, he 'felt that would not apply; he
was already in a descent'.
T he FO testified that the entire crew was busy
afte r they desce nded from 1700 feet, 'but not to the
poin t where iL was of" great concern to me'. He also
noted however, that 'the check list was delayed
because we were not aware that we were at the final
approach fix until we recei ved clearance clown Lo
our minimum descen t altitude'; and further , 'we
were definilel)' not in the conligtll"ation over lhe
final approach fix that we had desired'.
'
The captain expect.eel to be vectored to intercept.
the final approach course and be given warni n g or
the FAF so that he '. . . could have the aircrart in
lhe lauding configuration at the time (h e) arrived
over the final fix'. He did not receive the
information he 11eedecl, particularly the distance to
the FAF, although he knew that it was five miles
from the runway. If he had received this distance
information the aircraft would have been stabilised,
there would have been 'much less to do after
passing the final approach fix', and 'more attention
(would have been) d irected to flying and less at
accomplishing other functions'. The captain LesLiliecl
that he felt a little rushed, b ut · . . . didn't feel
rush ed enough to execute a go-around at tlut
point'. In response to the question 'At a ny time did
you d1ink the approach should be abandoned or
refused ?' he answered, 'If I had thought so, I would
have gone around'.
The fligh t engineer testified that after they were
cleared to the MDA he had 'a slight reeling or rush'.
H e said that the controller gave them a turn about
th e same Lime they were cleared to the MDA, a nd
he ' . .. felt like we were a little bit rushed due to
where we were at in the check list and everyth ing,
but I didn't tl1ink it was that serious'.
Ground proximity warning system
When the GPWS system operates, large
undimmable red 'pull up' lights located on the
lower right hand cor ner or the cap tain's and FO's
instrument panels provide a visual warning; aural
warning is provided by a speaker located i11 the
cockpit ceiling. The GPWS inhibit switch, which
de-activates the system , is located on the flight
engineer's lower panel and is safety wired in the
a r·med position . If the system is inhibited and the
switch is then returned to the armed position there
is a fou r second dela y before it resumes n ormal
operation.
The GPWS h as fi ve warning modes, but only two
arc pertinent to this accident:
M ode 1 - Excessive descent ratP b1>low 2500 }r'el abovt'
ground
Mode l does not depend on aircraft configuration
and functions all the time. I t is triggered by a
descent rate of 1700 feet per minute at 700 reel .
AG L, decreasing li nearly to about 1400 fee t per
mi nute at ground level.
ModP 4 - Non-lauding configuration below 500 f eet
AGL.
Wid1 the gear down a nd flaps set at 25 degrees, a
Mode 4 warning is Lriggered at 500 feet AGL at a
sink rate or about 1420 feel per minute.
Modes l a nd 4 activate visual and aural alerts
followed by a verbal com mand 'pull up, pull up'.
The warnings are conti nuous until the condition is
corrected.
If a GPWS warning is so unded on descent
company instruction; provide the following '
guidance to the flighL crew :
Aviation Safety Digest 108 I 27
�' It is not intended that a missed approach be
conducted in each case in volving a G l'\\'S \\'arning.
The GPWS a lerL is a warning that the cre1r must
immediate ly focus the ir attentio n on terrain
proximity a nd make a determina tion as to wh ethe r
the warning is valid . If there is a ny d oubt as to the
validity of the warnings, positi ve action to alter the
flight p ath to stop the warn ing should he initiated
immediately. This action is particularl y appropriate
under the following conditions:
(a) While manoeuvring for an approach at night or
in instrume nt conditions.
(b) When established on an approach wh ere vertical
guidance is unreliable .. .'
When the GPWS warn ing sounded, the captain
looked at his altime ter and instanta neo us vertical
speed indicaLOr (IVSI) a nd ' ... misread the
altimeter. I had 1500 instead of fi ve (500 f"cet), and
m y rate of descent was in the vicinity of 2000 (feet
per minute)'.
The FO thought the a ircraft was still above 1000
feet when the GPWS activated. He said that he
'noticed an excessive desce nt rate', ide ntified that as
the cause of the alarm , and broug ht it to th e
captain 's auc ntion . He thou ght that the ca ptain had
acknowledged the information; he saw the ca pta in
initiate bac k pressure on the yoke, he fdt the
aircraft respond , a nd at that point th e gro und
proximity warning syste m ceased'.
The captain believed that since he was at 1500
feet whe n the GPWS wa rnin g began, he did not
make an y drastic corrections , because he
'. .. wanted LO make it as s mooth as possible'. He
jus t 'eased the yo ke back and J think I used a little
cruise trim . . .' but did not acid powe r. 'When I
started shallowing the descent, the warning went o ff
and I thought the problem had been solved'. H e
also checked on terrain proximity. ' I looked for
terrain. There was none to see. I could have used
the radio altimete r but did not do so because I was
mentall y above a thousand (leer) a nd I don't
normally use it on this type of approach until after
I have passed a thousand'.
The loudness of the a ural warning made verbal
commun ications be tween Cl'ew members difficult.
Although the re mark , 'Did yo u (ge t) your thing?',
was recorded on the CVR, the ca ptain did not recall
making Lhc remark and the FO did not reca ll
hearing it. A similar GPWS on anOLher compan y
Boeing 727 was measured for loudness; it produced
a level of abour 100 dB. According to acoustics
experts, this noise level would impede normal
verbal communication.
The f1ight engin.eer thought he saw 700 feet on
the altimete r when the GPWS activated. H e heard
the remark, 'Did you (get.) your thing?', and
believed it was the ca ptain talking; however, because
of the noise or the GPWS warning, he was not
positjve of the exact words or whom the ca ptain was
addressing. He said he asked if the captai n wa nted
the GPWS shut off but the CVR transcript does noL
corroborate this statement; he then heard the FO
say that the descent rate was 'keeping it up' and
replied , ' I am disconnecting this. Okay, .iust a
second'. The flight engineer broke the safety wire
and turned off the GPWS. Later he returned the
switch to the armed position. H e thought that the
system wou ld reactivate if the aircrart was still being
28 I Aviation Safety Digest 108
operated ·within the a la r111 parameters of an)' mode
of t!1e sysLem". T he CP\\'S alarm d id not sound
aga111.
Altimetry
The captain 's and the FO's instrume nt pane ls were
equipped with drum-pointe r type barometric
altime te rs, in which hundreds of feet a re indicated
by a radial pointe r and thousands of feet arc
indicared on a rotating drum.
Th e captain said that he mis read his altime ter a t
500 fee t and believed h e saw J 500 feet. 'Wh en that
figure got on m y mind as I ran my sca n af"tcr that, I
was seeing 400 a nd 300 and the )' we re 14 a nd 13 in
my mind . I was look in g at the needle instcas! o f
looking at the I OOO foot marker in it. I didn't
actua ll y look at the I OOO foot pointer at the time . l
just glanced down at the 100 foot pointer'.
After being cleared to the MDA the FO reset the
a ltitude alert system a nd shifted his vision outside
the cockpit to seek ground cues. He saw a red light
which he was unable to id e ntify and his au e ntion
re mai ned ouLside the aircra fL until the GPWS ale rt
began . After the ale rt was silenced , he 'refere nced
(his) altimeter - in pre pa ration for , .. one
thousand foot call. Tha t was 11·hen (he) noticed
I I 00 feet.' He said his procedure fo r readi ng the
a ltimeter is to read the pointer first. 'That is the
most obvious, because the hand is pointing to a
numbe r'. Next his eyes go to the window, and he
notes the thousand that is associated with the
previously observed hundred reel, and in his mind
computes the a ltitude.
H e stated that ' Each pilot has a built-in time
clock, so LO speak, where yo u are in a ha biL of d oing
certain things - selecting fl aps, whatever, and
looking back at your instruments'. Jn this case the
aircrart h ad auaincd a highe r d escent rate tha n
normal , which he was 'not aware of at th e tim e'.
'When I looked bac k refer e ncing m )' instruments
cx pe(ting to sec 1000 feet, in m y own intern al time
clock, that was whe re I ex peered that we wou ld be,
a pproximatel y J OOO feet. Thal was confirmed when
I saw the " I". I initiall y read that as 1100 feet
beca use that is what I ex pected to see'. He <idcled
that he failed to make th e required altitude callouts
beca use he was never aware or the fact that th e
aircraft was below I OOO f"cet until just before
impact. Accordin g to the CVR, the only altitude
callo ut he made was at 50 feel.
The ca ptain a lluded to a similar sensing o r time
passage durin g the descent, ' .. . normall y when )'OU
stan to descend , you d on't ex pect to go through
this great an altitude this quickl y, and at the
completion of these things you just nonnall y expect
Lo be al <i higher altitude than we we re . .. '
The captain's <ind FO's r adio altimeters , located
nea r th eir attitude indicators, provide a bsolute
altitude data be low 2500 feet AGL Both were set to
the proper MDA for the approach , a nd therefore
the MDA warning lights on the flight directors a nd
above the radio alti rncLcrs should have illumi11ated
when the aircraft descended below the MDA.
Th e ca pta in a nd FO could not state whether the
MDA lights were illu111i11ated , but they could not
recall seeing them , and did not recall ever looking
at their radio altimet ers. They added that the radio
altimeter is a backup instrument until the aircraft is
beloll' 1000 reel and that there is no need to include
it in th eir monitorin g sca n un til the n . Since, in their
minds they neve1· reach ed 1000 feet, they did not
expand their scan pattern to include the
mstrume nt.
Operating procedures
Accord ing to the compan)''s B-727 Flight Ma nua l,
the pilot n or flying is required to call out the
following:
' 1000 feet - (SPEED) and (SINK RA TE),
200 feet above (MDA) ,
100 feet above (MDA),
MDA.
Runway in sight or Missed Approach Point'.
He is a lso required to call out any excessive
deviations from the desired sink rate and target
indicated airspeeds.
The flight manual also advises the pilots: 'IF AT
ANY TIME during the approach the aircrart
alignment, altitude, speed, sink rate, or any other
factor gets o ut of bounds to the point that excessive
manoe uvring is necessary to achieve the proper
re-alignment, a MISSED APPROACH shall be
commenced'.
It states that the u se or the f1ig ht director on an
MDA-type a pproach is optional but recommends
that the flight director no t be used fo 1· the descent
portion o r ADF or ASR a pproaches because o r the
workload added by manua l control and the
confusion that results.
Analysis
The evidence showed that the radar controller did
not adhere to established procedures designed to
aid the flight crew in the proper pacing of their
cockpit duties during the ASR approach. He was
required to position the aircraft on the final
approach course at least eight miles rrom the
run way, but gave the aircraft its vector to the final
approach course about five miles from the runway,
and the crew completed the turn a bout six seconds
after they were told they were four miles from the
runway.
Since the ASR approach is not based on a
navigation aid which provides a portrayal of
position d ata on the aircraft's navigation
instruments, the pilot must depe nd on the
controller for informa tion as to his a ircraft's
position rela ti ve to the ai1·p o rt at all times,
particularly information concerning distance from
the final approach descent point, so that he can
configure his aircraft for the approach in a timel y
manne r. Although the controller did provide the
Oight with position informatio n several times, he
did not give the required 'advance notice of whe re
descent will begin'. He contended that this notice
was no lo nger requ ired , since he had cleared the
aircraft to descend to the MDA before it reached
the FAF. However, the standard procedures are
intended to ensure that the controller affords th e
pilot preparation time to configure his aircraft for
the impe nding linal descent, and the clearance to
descend to the MDA half a mile before the d escent
point did not comply with either the in tent or
recomm e nded phraseology or these procedures.
The controller said he h ad mi~ju dgcd the
aircraft's distance and turned it on to linal inside
the recommended distance. However, he knew that
the aircraft was in a 'descent configuration', Lhat he
had cleared it to the initia l approach a ltitude about
six miles from the runway, and that it was
intercepting the final approach course about 4.5
miles from the runway. Since the controller, had
received no informa tion from the pilot lo indicate
he was havi11g difficulties, there was no reason for
him ro terminate the approach.
Because the controller did not position the
aircraft on the final approach course outside the
approach gate, he created a situation that m~de it
impossible fo1· the captain to configure the a1rcraft
in the manner speci fi ed in the flight manual in that
he would have had to lower the naps to 25 degrees
and extend the landing gear either as h e was
approaching the fix or on the inte rcept turns to the
!ina l approach course.
While on a 110 d egree heading, which was within
40 degrees of what would constitute a downwind
leg to runway 25, the captain was told that his
aircraft was six miles north-east of the field; 34
seconds later he was turned to a heading of 160
d egrees. He should have recognised tha t this
heading app rox imated a base leg to runway 25 , and
that it would keep his aircraft within six to eight
miles of the licld until he was turned to the final
approach course and fix. Since the captain knew
that the FAF and the 'start descent' point we re five
miles from the runwa y, he should have recognised
that the intercept turn or turns from the 160
degree h eading would place him on the final
approach course at, or possibly inside, the FAF.
Thus, he should have known that he would need lo
extend the flaps to 25 degrees and lowe r the
landing gear eithe r on this leg or on the turn to
intercept the final approach course. The evidence
showed that either he did not recognise what was
happe ning, 01· he was unable to make these
aqjustments to the recommended procedures.
The captain did nothing to further configure his
aircraft until about one minute after it was turned
on to the intercept heading to the final approach
course, when he requested 'twenty five flaps'. T he
landing gea r was not extended until half a minute
later, when the aircraft was completing its turn on
to the final approach course and was descending
th rough about 940 reel.
These delays resulted in landing flap neve r being
extended, and increased the captain's workload
during the d escent, thus contributing to the major
causal area of the accidcnL - a lack of altitude
awareness. T he delay in beginning the 'before
landing' final check list also contributed in part to
the FO's failure Lo provide the captain with some of
his required altitude callouts.
The evidence disclosed that the FO either did not
look al his altime ter or he did not perceive what he
saw until Lhc aircraft was at 100 feet, when it was
descending at 20 feet per second.
The FO's duties also required him to seek ground
cues during the descent. The origin o r the red light
which he saw was never determined but his
preoccupation with it caused him to omit several
required c::allouts. He did not call out a descent rate
and a n airspeed which exceeded the recommended
parameters, and he did not make the required
altitude callout at 1OOO feet; his explanation for the
Aviation Safety Digest 108 I 29
�r
latter omission was Lhe upset of his 'inner time
result of further thrust reduction and the extension
clock' which was based on a normal descent raLe.
of the landing gear.. The captain had establish ed an
T h e first positive indications that the FO had
attitude which initially produced the desired rate of
returned his atten Lion inside the cockpit were his
descent; however, he still kept retarding thrust until
exLension of the landing gear and his response to
it reached 12.5 per cent of take-off rated thrust. At
th e releva nt check list challenge. He did not recall
this point, the airspeed was about 10-1 5 knots IAS
any altimeLer or lVSJ readings d uring this period
over target speed and it appears that the thrust
and had either redirected h is atten tion outside Lh e
reduction was an attempt to reduce airspeed while
aircraft or was rnonito1·ing the landing gear warning maintaining the pitch attitude. Since the captain did
and position lights. During this time the aircraft
not alter the pitch attitude, the lower thrust settings
descended through 680 feet and h e did not provide reduced the airspeed and increased the descent
the captain with the requ ired '200 feet above MDA'
rate. Further thrust reduction resulted in th e
call.
aircraft approaching the MDA with thrust at fligh t
The GPWS wa rning began shortly after this, and
idle and with a descent rate at or above 1600 feet
Lhe ensuing cockpit conversation disclosed that Lhe
per minute.
captain's and FO's attention was directed
The evidence concerning this phase of the flight
immediaLely to their IVSis a nd the 2000 feet per
disclosed that the demands of trying to establish a
minute descenL rate, not to their altimeters. Neith er
stablilised approach and ensuring that the MDA was
noted that the MDA h ad been passed.
reached in sufficient time at a safe airspeed might
While th e FO's failure to provide the captain with
have contributed to a breakdown in the captain's
altitude callouts during the upper part of the
instrument scan pattern. He evidently fixed his
approach can be attribuLed to his distraction by
attentio n on the flight director indicator and e ither
o utside visua l cues, a nother source of distraction
excluded the altimeter and IVSI from his scan , or
from abo ut l OOO feet clown Lo Lhe activation of the
placed them at the outer perimeter of his attention
GPWS was his workload during la nding gear
span wh ere he did not perceive thei1; read ings. Of
extension and the associated monitoring tasks.
paramoun t importan ce to this phase of the flight
Under normal circumstances these Lasks should
were th e required altitude callouts, which the FO
have been com pleLed before the start of the descent failed to make.
to MDA, not upon leaving l OOO feet.
T he captain experienced the same sense of p ace
A r eview of the captain's activities from 1700 feet
that m isled the FO a nd , since he was not aware of
to the activation of the GPWS disclosed that from
any rate of descent in excess of 1000 fee t per
1700 feet Lo abo u t 1300 feet he had established a
minu te, he d id not expect to go through 'this great
stable approach path - the average rate of descent
an altitude this quickly'. Thus, when the GPWS
was about 600-800 feet pe r minute; there was a
acti vated and he saw 500 feet on h is altimeter h e
slight increase in airspeed fro m 154 to 160 knots
believed it read 1500 feet. The evidence sh owed
IAS; the thrust was stabilised at 25 per cent of
th aL the captain was well aware of his altitude at
Lake-off rated thrust; and , except for a momentary
l 700 feet, he knew he was cleared to desce nd to
pitch down as the flaps were extended to 25
1500 feet, he knew h e was cleared to the MDA, a nd
degrees, the p itch attitude decreased slowly from
h e set up a 1000 feet per m inute descent rate some
three degrees nose up at 1700 feet to two degrees ' time after receiving this clearance. The Board could
nose u p at about 1300 feet. Had Lhe landing gear
not determine how, under these circu mstances, the
been extended a nd the flaps lowered to 30 degrees,
captain could have read 500 feet and interpreted it
the aircraft would prnbably have achieved Lhe
LO be 1500 feet, an altitude he knew he h ad left
desired parame ters for the approach . Howeve r,
almost one minute earlie r.
because the landing gear was not extended for
T h e captain also said he mis read his altimeter
another 25-30 seconds and th e flaps remained a l 25
twice more after he made the first error. Since he
degrees, the capLain experie nced added difficul ties
kn ew h e was descending towards the MDA and h e
in his atte mpts to attain the desired descent rate
could hear the ground proximity warning, th e
and airspeed.
Board d id not believe it reasonable that h e would
Contrary to the fligh t manual's recommendaLions, repeat the first error twice more. While the warning
the captain continued to use his flight director
was sounding, however, the captain recalled the
during Lhe approach , bm only for heading
IVSI reading correctly. He recalled his control
guidance. An FAA report o n pilot eye-scanning
inputs, the man ner in which they were made, and
techniques notes tl;rnt during a flight director
the results these in puts h ad on the descent rate.
approach, 74 per cent of the pilot's scan time is
Based on the foregoing, the Board conclud ed that
devoted to the fligh t director attitude indicator. In
the captain focused h is attention on the IVSI a nd
this instance, the manner in which the caplain was
either did not look at his altimeter or did not
using his flight director attitude indicator probably
perceive its reading.
The Board believed that the GPWS warning
caused him to devote a higher percentage o f his eye
scan time Lo the fligh t director indicator and less to
migh t have prevented the pilots seeing the MDA
th e other flight instruments.
ligh ts. Although the evidence disclosed that the
AL 1300 feet, when the turn to 250 degrees was
MDA warning light system was operatio nal and that
commenced, the captain increased the rate of
the proper MDA value had been inserted into the
d escent to 1000 feet per minute, decreasing thrust
radio altimeter, neither pilot saw these lights
illuminate. The activa tion of the GPWS warning
and lowering the nose to a p itch attitude of about
three degrees nose down. The pitch attitude
directed the attention of both pilots to their IVSis
the rea fter remained constant until the GPWS
a nd th e GPWS pull-up lights, which are much
warning began , but the descent rate increased as a
brighter than the MDA ligh ts. As a resul t neither
30 I Aviation Safety Digest 108
pilot saw the last automatic warning that might have
alerted him to the a ltitude.
The flight engineer believed he had been
instructed lo turn the GPWS oil and the CYR
tra nscript substantiates his belief. After the system
was turned off the flight engineer reset the switch.
He must have r eset it within four seconds of impact
however, since tl1C system did not have time to
recycle.
Once the GPWS had sounded, the captain
concu rred with the FO's analysis tha t iL was the
excessive descen t rate wh ich caused the warning .
He eased back on the control column, saw the
descen t rate lessen and heard the alarm cea~e. Bu t
the alarm ceased because the system had been
inhibited, not because of the change in th e d escen t
rate. The captain er roneousl y concluded that the
p roblem was solved. T he rate of descent h ad
d ecreased to 1600 feet per minute when the
warning was silenced and the captain continued to
d escend without checking his altimeter. In th is case,
his fa ilure to check his altimeter was vital to the
safety of the fligh t, since the performance analysis
disclosed that at this ti me the captain could ha ve
arrested the d escent and avoided the crash.
Because th e sky was dark and the aircraft was
being flown in instrumen t me teorological conditions
on an approach which afforded the pilot no vertical
guidance, a prudent capLain wo uld have initiated a
missed approach at the onset of the warning rather
than try to d etermine its validity. T he proced ures in
the company fligh t ma nual stated that u nd er these
condi tions positive action to alter the flight path
would be 'p articularl y appropriate'. Merely easing
the nose of the aircraft up to reduce the descent
ra te withou t add in g thrust cannot be classified as
such positive action. The fact that the a ircraft
entered the warning regim e in a three degree nose
down attitude , at a descent rate of 2000 feet per
m inu te and with all engin es at or n ear flight idle
should h ave constituted added grou nds fo r the
capta in to positively alter the flight path.
The GPWS proced ures also required that the
pilots ' focus their attention on terrain proximity' to
determine the validity of th e warnin g. The
beginning of the GPWS alert cons tituted , if not a n
emergency, certainly an abnormal situa tion. and
should have made them check every available
altimeter system to fix the position of the aircraft
relative to the terrai n. The pilots knew they were at
an al titude where the radio altimeters were
operative, th ey knew that the approach was being
made over water, and Lhey knew th at there were n o
terrain features presen t that would have made the
radio altimeter readout suspect. Under the
circumstances, the Board concluded that an
experienced flight crew should have checked their
rad io altimeters, since these would have provided
them with a n immediate read ou t of absolute
altitude.
In summary, the Board believed that th e ATC
p rocedures affected the con d uct o f th e approach
and, therefore, contributed to the chain of events
which led to th e acciden t. Although the controller
h ad placed the aircraft in a position from which th e
a pproach could have been completed safely, he also
h ad placed it in a position where th e captain had to
alter the timing of his check list procedu res in orde r
to configure his aircraft more rapidly than usual.
While the controller's handling of' the fligh t did not
place the aircraft in a dangerous position, his
non-standard procedures made the approach more
difficult for the crew to accomplish.
·
T he accidenl would have been averted , however,
had the pilots performed to the established'
standards expected of airline flight crews. It was
appar ent that a lack or p rofessionalism on the
crew's part contributed to th eir inability to recover
from a procedural error on the part of the
controller.
Probable cause
The Board determined that the probable cause of
the accident was the flight crew's unprofessionally
cond ucted non-precision in.stru ment approach , in
that th e ca ptain a nd the crew failed to monitor the
descent. rate and altitude, and the first officer failed
Lo provide the captain with requi red altitude and
approach perfo rma nce callouts. The crew failed to
check and u tilise all instruments available for
altitude awareness, turned off the ground proximity
warning system , and failed to configure the a ircraft
properl y and in a timely man ner for approach .
Contribu ting to the accident was the radar
controller's failure to provide advance notice of the
'start descent' point which accelerated the pace of
the crew's cockpit activities after the passage of the
final a pproach fix •
(Conde nsr,dfrom a re/JOrl /mblished by the National Transportation Safel)'
Board, USA)
From the Reports ...
QFI commenting on a student pilot: 'When this student
starts the engine, he starts a chain of event~ over which he
has no further control'.
Aviation Safety Digest 108 I 31
�
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Aviation Safety Digest, number 108 (1979)
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108
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1979
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�Vision 2
- sunglare
The second article in a series concerning the physiological, psychological and environmental faqtors that
affect visual efficiency.
Below: A good example of the sung /are hazard. This photograph was taken at the location of the accident involving the Cessna 182, at
the same time on the following day.
3
Vision 2 -
sunglare
5
Aerodromes - government, licensed or
authorised landing area?
7
More about pre-flights
8
Beach operation of aircraft
1O Pilot landing expectancy and
the missed approach
Aviation Safety Digest is prepared in the Air Safety Investigation
Branch and published for the Department of Transport through the
Australian Government Publishing Service, in pursuance of Regulation 283 of the Air Navigation Regulations. It is distributed by the
Department of Transport free of charge to Australian licence holders
(except student pilots), registered aircraft owners, and certain other
persons and organisations having a vested operational interest in
Australian civil aviation.
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing Service. Enquiries should be addressed to the Assistant Director (Sales and Distribution), Australian
Government Publishing Service, P.O. Box 84, Canberra, ACT 2600.
Subscriptions may also be lodged with AGPS Bookshops in all
capital cities.
12 The Engine Doctor on gauges
Change of address:
15 Advice about cables from a LAME
Readers on the free distribution list should notify the Department of
Transport, P.O. Box 18390, Melbourne, Victoria 3001.
16 Manoeuvring speed and structural
failure
18 In brief
19 Channel ised attention
20 Emergency landing techniques in
small, fixed-wing aircraft
25 In_ brief from Papua New Guinea
26 Birds, birds and more birds ...
l
Subscribers should contact the Australian Government Publishing
Service.
©Commonwealth of Australia 1979. The contents of this publication
may not be reproduced in whole or in part, without the written authority of the Department of Transport. Where material is indicated to be
extracted from or based on another publication, the authority of the
originator should be sought. The views expressed by persons or
bodies in articles reproduced in the Aviation Safety Digest from other
sources are not necessarily those of the Department.
Reader contributions and correspondence on articles should be
addressed to:
The Editor,
Aviation Safety Digest,
Department of Transport,
P.O. Box 18390, Melbourne, Victoria 3001.
RM77/30217(3) Cat. No. 79 9024 X
28 From a pilot in England
30 MD and the taildragger
Printed by Ruskin Press, 552-566 Victoria Street, North Melbourne,
Victoria.
Note: Metric units are used except for airspeed and wind speed
which are given in knots; and for elevation, height and altitude where
measurements are given in feet.
Covers
Scenes from general aviation
maintenance works~ops
It was late afternoo n when a Cessna 182 was
landing at an aerodrome in Western Australia. The
pilot had flo wn a full circuit and decided to land on
the 300 degree strip, into the five knot wind.
During the approach the passenger, who w~s also a
pilot and endorsed on the Cl82, suggested that
landing towards the north-west may be troublesome
because of sun glare. T he pilot decided to continue
with the approach.Just off the north-western end
of the strip was a sawmill and the smoke from the
sawdust fire was drifting over the aerodro me and
adding further to the visibility problems.
On final approach with 30 degrees of flap selected
a nd 70 knots airspeed , the pilot assessed th e situation
and d ecided to continue the approach. The su n was in
line with the strip and about ten degrees above the
h orizon. All app eared normal until just after the
roundou t and touchdown when the landing gear
struck a mound of earth about 30 metres before the
marked thresh old. T h e nose gear was detached and
the aircraft slowly overturned. The two occupants
were not seriously injured.
2 I Aviation Safety Digest 107
A Piper PA28-235 was on an early morning flight
to an aerodrome in Papua New Guinea. On board ,
besides the pilot, were a L AME and another pilot
who were to repair and fl y out another aircraft
stranded at the aerodrome.
The pilot of the Cherokee had gained most of his
flyi ng experience in Papua New Guinea. He had
not previously operated into this aerodrnme but
had sought information on the strip from other
pilots. I t was a licensed aerodrome with a one-way
landing d irection of 120 degrees.
Descending into th e circuit, the pilot cancelled his
SARWATCH at 0706 hours and made a continuous
base leg descending turn on to a short, low final
approach . While he was manoeuvring to align the
aircraft with the strip the rising sun broke over the
top of the hills, obscuring all forward vision . The
pilot did not initiate a go-around, however, because
he believed the aircraft was settled on the proper
d esce nt pPofile and was near the threshold. The
aircraft continued its descent into tall cane grass,
stopping on soft ground 25 metres short of the
threshold, with t he gear collapsed.
Aviation Safety Digest 107 I 3
�Aerodromes - government, licensed
or authorised landing area?
.,
In each of the above accidents the pilot's judgme nt
of distance and height was significantly_a~"fected by
sungla re. Flying against the su_n , wh e n it is low o n
th e h orizon , can block out a high pe rcen tage of
normal cockpit visibility, es p ecially in the p resence
of a tmospheric debris such as dust, h aze, smo ke,
e tc. T his becomes particularly hazardous wh en
flying in areas of high traf~c de nsity. In some
circumsta nces, runway su rfaces may also reflect
sun glare in a ma nner that will seriously interfere
with forward vision.
· As well a s the p roble m of direct _s:unglare,
..
visibility can a lso be reduced by _ve1hn~ glar e ~nsmg
from th e reflection of sunlight fro m dirt particles or
scra tches a nd crazing of the windscreen.
T h e r emed y fo r th e problem s con sists firs tly of
planning , if possible, to fly with the sun . When
westbound, start early and set d own by .
m id-after noon ; if eastbound , star t later m th e
mornin g a nd set down before last light. If there is a
4 I Aviation Safety Digest 107
ch oice of take-off a nd la nding directions carefull y
consider the effects of sunglare before the final
decision is made. If unavoidable, direct glare can be
partly blocked by a sun visor , T h e use of sunglasses
can also be of sligh t benefit.
Pilo ts operating with th e sun behind th em should
be ale r t to conver ging traffic from a head and,
notwithstanding the rules o f the air, be prepared to
give way on the assum ptio n th at the pilot of th e
other aircraft may not see you.
Veiling glare can be reduced by ensur ing that dir t
a nd surface scratches ar e removed in accordance
with the instructions in the Owner's Manual or
Pilots Ope rating H a ndbook fo r your aircraft. If the
windscree n h as more tha n a minor d egree of
crazing, serious thought sh ould be given to having
it re placed. While this may be costly, the benefit
that could be gain ed is th e pr evenuon of an
accide nt involving a far greater cost •
A recent inciden t report, submitted by the manager
of a licensed aerod rome, concern ed a P A23 aircraft
landing there whe n th e aerodrom e was closed by
NOTAM to air craft above 1300 kg MT OW, because
of a soft, wet su rface. The aircraft was on a NOSAR
flight to the licensed aerod rome and oth er landing
areas aroun d a primary control zone. The two
private pilots o n board were flying leg-for-leg bu~
neither h ad con tacted an Airways O perations Umt
or th e aerodromes directly to check on the
serviceability sta tus. One of the pilots su ggested
that, as it was a NOSAR flight to ver y familiar
a erod romes, h e, 'like the majority of the other pilots
flying around the traps, n eglected to check the
N OTAMS fo r that d ay.'
While the ab ove incident would appear to have
r esulted from a d egree of that contemptible disease
'complacen cy', th er e are enou gh occu rrences on
record to su gges t th at some pilots are unfamilia r
with th e differen t kinds of aerodromes and the
correct methods in establishing their serviceability.
T her e are three kinds of aerodromes and these are
described below with the different p rocedures
applicable to each.
Government aerodromes (G)
These are owned by the Commonwealth of
Australia an d admi nistered by the Depar tment of
T ran sport and/or the Department of Defence in
some cases. Responsibility for aerodrome
ins p ections and serviceability r eports rests with the
officer-i n-ch arge; u nserviceabilities are notified by
NOTAM. There are no individual landing charges
a t govern me nt aerodromes as these costs are
covered by Air Navigation Charges and prior
permission to use th em is not req uired except in the
case of some Defence aerodromes, th ough of course
the flight notification and air traffic clearance
req uiremen ts h ave to be met. Government
aerodromes are indicated by '(G)' after the
aerodrome name in AIP AGA and are included in
VFG AGA.
Licensed aerodromes (L)
T hese are aerodromes normally owned by local
sh ire councils a n d sometimes by private owners,
which m eet minimu m stand ards set by the
Depar tment. T h e lice nsee nominates a n Aerodrome
Rep or ting Officer wh o is responsible for ensuring
the aerod rome continues to meet the ap plicable
standards. If it does not and immediate rectification
is not p ossible, he will report the u nserviceability to
an Airways Operations Unit which will raise a
NOTAM. Licensees are p ermitted to charge landing
fees approved by the Dep artment. The aerodromes
where fees are payable are listed in A I P GEN and
the VFG. P rior permission from the licence holder
to land at these aerodromes is not required.
Licensed aerodromes are indicated by '(L )' after the
aerodrome name in AIP AGA and are also included
in VFG AGA.
Authorised Landing Areas (ALA)
U nder the provisions of AN R 85, any place may be
used as an aerodrome provided it complies with the
descriptions and conditions specified b y the
Secretary to the Department of Transp ort and
outlined in AIP AGA-6 and VFG aerodrom es
section. T he responsibility for compliance with these
r equir ements rests with the p ilot in command. .
Compliance should be ensu red before und er takmg
a flight to or from the proposed ALA.
The majority of ALAs are on private property
and althou gh there is no longer a DoT requirement
to obtain the owner's permission to op erate from
the ALA, there is an obligation to so do under
common law. I n many cases, contacting the
occupier or controlling authority is the only way
that the pilot can obtain a report on the
serviceability of the aerodrome.
Throughout this cou ntry there are numerous
ALAs which have been r aised to a high standard
and are u sed as bases for DoT approved fl ying
schools. Authorised landing areas which are
app roved for use by fl ying schools are required to
meet standards additional to the normal AL A
standards. Often these higher standards tend to
suggest that th e aerodrome is something more than
it is and visiting p ilots tend to overlook the courtesy
of seeking the occupier's consent prior to using the
AL A. It is only pilots operating within the
authorisation given to the flying school who are
exempt. O ther p ilots are still obliged to ob tain
consen t from the occupier or controlling au thority
before landing at such locations.
Do not be misled into believing that because a
certain aerodrome is regularly use d b y man y
aircraft, it is automatically available for general
operations. If the aerodrome is not listed as a
government or licensed aerodrome in the AIP, VFG
or associated NOTAMS, it is an ALA and the
responsibility for the operation rests with the pilot
in command. Ensu re that you know th e status of
you r destination aerodrome and that you obtain all
the current information on its serviceability state.
A recent accident and a contr ibution from one of
our readers further help to illustrate the degree of
care required to ensure that all th e details likely to
affect an aircraft's operation ar e obtained prior to a
proposed"landing at an ALA. T hey highligh t the
responsibility that general aviation pilots m u st
exercise when pla nning such fligh ts.
Aviation Safety Digest 107 I 5
�•I
I
T he p ilot later said that on fl ying over the area
The accide nt report shows that, althou gh not
h e h ad observed the p lough ed section, with the
required by Departmental regulations excep t for
Cessna 182 parked adjace n t to it, and h ad
ALAs u sed by training organisations, marking the
concluded that this was the strip which had been
boundaries of ALAs can be of paramount
har rowed as an improvement, and that the 182 had
importance in ensuring that the pilot uses the
used it. Knowing that the 206 h ad larger wh eels
correct area. If there is no permanent marking of
than the 182 and wo uld handle the furrows better
th e area, the pilot sh ould ensure that he is
adeq uatel y briefed on the correct recognition of the h e proceeded to land on the ploughed area.
T he pilot chose the highest par t of the strip and
ar ea or else arrange for some temporary marking to
approached with full flaps for a normal landing.
prevent mis-identification.
During th e landing roll the nose leg snapped at
T h e pilo t of a Cessna 206 in tended to land at an
about 20 knots a nd the a ircr aft overturned. T h e
ALA situated in a large paddock on a Qu eensland
pilot immedia tely turned off both switch es and left
property. The dimensions of the area were more
the aircraft. Only then did h e realise th at the
than adequate fo r this operation but the re were no
markers and the growth of grass made it difficult to ground had been ploughed.
T he uneven surface had been slightly flatte ned by
discern the strip from the air. T he pilot had last
landed there about three years previously and knew recent heavy rain and the p ilot did not d etect its
unsuitable nature. He made a normal touchdown
that the stri p was on a sandy r idge and considered
but, as the weight settled on to the wheels, th e nose
to be 'all weather'. H e recalled it was about 750
wheel dug in and kicked to th e left in the soft,
metres long a nd a ligned north/south . On the
moist soil. The resultant loads caused the n ose
morning of the flight the pilot h ad been conLacted
wheel fork to b reak. The nose gear strut then d ug
by telephone a nd h ad arra nged for a local resident
in , causing th e aircr aft to decelerale ra pidly and
to inspect th e strip in his veh icle and ensure tha t it
overturn 69 metres from the initial touchdown
was serviceable.
On his arrival at the strip the local reside nt saw a
point.
O ur reade r's story d emonstrates that d espite the
Cessna 182 parked near th e e nd of it and h e
considered that, if that aircraft h ad used the strip , it care taken to procure information, d etails obtained
from a no n-pilot la yman are subject to
sh ould be satisfactory. Adjacent and parallel to the
misimerpretation . It r eiterates th e difficulty of
strip was a 27 metre wid e section of the paddock
assessing the suitability of a landing strip fro~ the
which h ad recently been disc-ploughed.
air with the consequent importance of ensunng tha t
The Cessna 206 arrived overhead and proceeded
to join the circuit on the crosswind leg for a la ndi ng a ll relevanL details o n ALAs a re obtained before
toward s the n orth. T h e wea ther at the time was fine flight.
.
' In 1975, with 300 h ours of aeronautical
and calm . As the people on th e ground watch ed,
experie nce over two years, mainly in th e far west of
the 206 touch ed down on the ploughed a rea. After
NSW, I p lanned a trip with m y fa mily in a Cessna
a short ground roll, th e nose leg d etach ed and the
172 to a small tow n in the Riverina area of NSW.
aircraft overturned. The pilot was not injured .
6 I Aviation Safety Digest 107
'I had never been there before, so I asked the
would work that out. " In the map h e had drawn he
friend we wer e to visit to post d etails of the nearest
h ad not mentioned the gradient or the hill, no
place we could land. He advised me the re was a
d oubt being unaware how such things are not as
strip o n a nearby farm, obtained the owner's
obvious from the air as from the ground.
permission to use it and sent what I felt was a very
'It was only some time later, after reading the
detailed map, with the warning I may have to buzz
Aviation Safety Digest and then turning to carefull y
the strip to clear it of sheep. The relationship of the consider the VFG section on Authorised Landing
strip to power lines, roads, fences, buildings and
Areas that I realised I had landed on a strip
silos was clearly sh own a nd the length was just
suitable only for agricultural operations. Almost all
sufficient.
m y experience was west of the Darling where
'Feeling adequ ately prepared we set off and after cropdusting and agricultural strips are rarely seen,
an uneventful ·flight arrived over the town,
and most strips exist for light aircraft and are
identified the str ip , noted ou r friend's car there and suitable for them to use.
cancelled Sarwatch. The wind was very light from
'During m y flying training I cannot remember
the wesl and, as the strip ran east/west, I decided to being taught or examined on physical requirem ents
land in a westerly direction. I had to overfly twice
of ALAs. I notice in the Air L egislation Examination
to m ove the sh eep a nd noticed quile a hill about
Guide for General A viation P ilots there is a question
half a kilometre to the east of the strip.
about ALAs, but not abou t physical requirements. I
'On m y first atte mpt to land, keeping well above
would suggest the inclusion of a question that tests
the h ill, I hopelessly overshot the strip and went
the pilot's a wareness of the need for an
around. Realising now that there was not much
obstruction-free go-arou nd area on an ALA .
room I tried lo fl y a more accurate approach.
'Furthermore I suggest in the VFG section on
Missing the hill by only about fifty feet, with power
ALAs an initial note, in large dark print, reading
off and full fla p selected, all looked fine as I
something like the follo wing:
crossed th e threshold and began to round out.
"WARNING - Throughout Australia there are
H owever with h alf th e strip gone a n d still no
many strips u sed for agricultural operations which
touchdown I decided to go around again. The
are unsuitable for private operations a s they d o not
wheels actually touched the ground and the small
meet the physical requi rements for private
amount of strip remaining made it a fairly
operation from Authorised Landing Areas, e.g. they
sh ort-field take-off, but I was sure it was the safest
may have an obstacle free take-off a nd approach
course of action and was glad to note clear
area at only one end of the strip, leaving no safe
app roaches to the strip from the west. Once safely
go-around area".'
climbing I thought abou t the problem and could see
This pilot's lack of training in ALA operations is
no way of doing a steeper approach after clearing
relevant a nd probably widespread. Few pilots are
the hill, so with almost nil wind I decided to land
properly introduced to the ALA requirements until
the o ther way, towards the east, u sing the easy
they have obtained their unrestricted priva te licence
approach from the west to set m yself up for a shor t wh en they a re able to op erate into th ese areas
field landing .
.
without the benefit of instructor supervision. It is
'I re me m bered that hill to the east and resolved
recommended that prior to an y operation into an
that any decision to go arou nd wou ld have to be
ALA, p ilots refresh their mem ories of the
made well out on the final leg. I t was only after a
requirements by reading the appropriate sections of
successful landing, using only about half th e strip,
th e AIP or VFG. If you are still in an y doubt abou t
that I realised the strip had a steep slope, falling
a pplication of the criteria consult your local training
away to the west. I remember looking at the slope,
organisation or a DoT officer.
a nd the hill, and d eciding Lhat a take-off to the east
The suggestion from our reader about a warning
would be impossible.
in the VFG will be incorporated in the next
'Later my friend told me, "They always take off
edition •
from the west an d la nd to the east, I thought you
More about pre-flights
From the United Kingdom we heard of an incident involving a privately owned Stampe SV4C aircraft.
The message in the incident did not concern the aircraft type but the fact that it was privately owned
and flown by the one pilot most of the time.
T h e owner/pilot re ported that he had noticed for
some time a slightly excessive degree of sid e-to-side
movement of the fin leading edge, but he thought
the movement was normal. I t was only when
a nother Stamp e owner carried out a pre-flight
inspection on the aircraft and remarked on the
a moum of movement, that the owner checked other
Sta mpe fins and fo u nd them to be more rigid.
Furth er inspection of his own aircraft revealed a
broken fin attachment plate.
As pointed out by the owner, the incidenL
highlights th e inherent d anger in the owner alwa ys
being the only one to conduct the pre-flight
inspection. (This could also be extended to a pilot
wh o is usually the only person to fl y a particular
aircraft). This owner had arranged for another
Stampe own er to do the pre-flight because,
notwithstanding first class maintena nce, h e f elt it
was all too easy for an owner to get so used to a
defect of this nature that he does no t realise the
significance of it.
Makes interesting food for thought, d oesn 't it•
Aviation Safety Digest 107 I 7
�Beach operation of aircraft
Page 11: The Royal Australian Air Force takes no chances with salt water corrosion. At the completion of each low-level maritime
reconnaissance mission, its Orion aircraft are washed in a 'bird-bath' to remove any corrosive substances.
'Let's have some fun and operate our aircra f"t from
a beach!' Wh y not? Well, just remember the owne r
will have to pay the price eventually.
Few people would drive their car in salt water yet
it is not uncommon to see both single- and
twin-e ngi ne aircraft worth up lo $250,000 taking
off and landin g on beaches running with salt water.
Co nsider - ve r y few modern ligh t aircraft or
their e ngines o r propellers have a ny form of special
salt wate r corrosion control applied during
manufacture; the refo1·e, once initiated, salt
wa ter-induced corrosion will propagate ver y rapidly.
People who may be impressed by advertising
materia l concerning the high resistance of
alu miniu m to corrosion should note that this ap p lies
o nl y to pure a luminium in isolation from all other
substances. In a n aircraft there are very few places
whe re pure a luminium is used. Similarly, the re are
virtua lly no p laces where any one material is used
exclusively. Often parts made from dissimilar
ma terials are fas tened together. For exa mple,
unprotected steel bra ke drums are bolted to
alu minium or magnesium wheel halves in most light
aircra ft. Corrosion is rapid when this combination
of pa rts is ex posed to sea water.
Yo u may believe that one can readily wash down
the aircraft inside and o ut to re move the salt. In
practice this is seldom attempted inside t he aircraft
a nd , if clone, is usually no t effective. In fact it could
well be that the dried salt products may be forced
furt her into areas to which they did not originall y
pe netrate. Use of a damp sponge or cloth co uld be
more e ffective for aircraft interior surfaces.
Inspection of ge neral aviation aircra ft known to
have been used in beach operatio ns has d isclosed
corrosion a nd sand-induced disintegration of:
-a ilero n a nd flap support arms
-w heel brake discs
-w heel bearings
- propeller blades - showing split leading edges
and erod ed rear faces
- spar webs - holed a nd with skin corrosion
--contro l cables
- bolts, nuts, locking devices
-landing gea r spring legs
-e ngine cyl inde r barrel cooling fins etc.
T he re is a te nde ncy Lo sell off aircra l"t a l"ter beach
operations and prospective new owners sho uld
make quite sure they are not purchasing a ircraft
whic h in a sho rt time will reveal expe nsive evidence
ol" sa lt wa ter-induced corrosion .
Apa rt fro m the corrosion aspects of beac h
opera tio ns, there is the matter of accelerated
mecha nical d ete rioration . T his can show up in the
fo n n of premature failure of land ing gear
assemblies and the ir a ttachme nts because of
increased wear or impact d amage caused by
8 I Aviation Safety Digest 107
operating in loose sand or ac ross those washes or
small water runs which cross many beac hes.
Owners should rea lise they will only get the
maintenance they request. If no Maintena nce
Re lease reference is made to unusual opera tions or
occurre nces then the LAME will p roceed as though
none has occurred unless he is ale r ted by obvious
damage or corrosion . Even tuall y the owner will pay
a greater price as a result of more rapid wear-out of
parts or a malfunction which could have been
avoided . LAMEs are not req uired to preserve your
aircraft; they a 1·e responsible for e nsuri ng it will be safe
for the next l 00 hou rs or one year subject to norma l
conditions.
It is simply a matter of where does' the LAME
stop. Corrosion, once started in rive ted asse mblies
such as the ai1·frame and wings of most light
aircraft., cannot be stopped except by de-rivetin g the
assem blies and using mechan ical methods followed
by chemical treatment and special paint ap plication,
a costl)' procedure.
-Think before you e ngage in beach operations or
roug h strip operations a nd in yo ur own interests
ad vise your LAME full y wh e n ordering
s ubsequent work to be d one o n yo ur a ircra ft.
- Try to establish the operating history of aircraft
yo u may be considering for purchase a nd have a
detailed inspection carried out by a n experienced
LAME before buying a ny aircraft.
- Take some action, between pe riodic inspections,
to preven t the onset of corrosion, e.g. spra)' oil or
an approved corrosion-inhibiting spra y o n to
cylinde r !ins, exposed nuts, cables, e tc. be fore
operating on the beach ; clean yo ur carburettor
air fi lter o f sand ; a nd sponge or was h down the
aircraft immed iately afte r ward s. In other words
treat your aircra ft as a marine aircra ft, carry out
the seaplane/amphibia n inspection called up in
ANO 100.5. l Appe ndix 4 but add the
undercarriage as a n ite m in lie u of floats. This
action will h elp to protect you r aircraft but if the
basic structure is not corrosion-proofed to marine
airci-aft standard s at asse mbl y you will still have a
corrosion problem in that a rea. o guaranteed
protection can be applied to an aircraft afte r
assembl)' or after ex posure to salt water.
Ir you are not the owner of the ai rcraft the n yo u
should seek the ap proval of the owner or hiring
agency before e ngaging in beach operations. T his
will give the owner the opti on or d eciding whether
or not he wishes to expose his aircra l"t to the
hazards of this kind of operation.
These procedures a lso ap ply to a ircraft statio ned
at airports such as Coola ngatta a nd Mackay which
are situated within the salt water haze zone often
apparent at the seaside •
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Aviation Safety Digest 107 I 9
�Pilot landing expectancy and
the missed approach
Pilot ex perience substantiates the fact that an actual
IFR missed approach is an infrequent event. Pilots
have difficulty recalling any past actual IFR missed
approaches. They also have difficulty recalling the
missed approach procedures for approaches that
are so familiar they are committed to memory.
A possible reason may be that we are so used to
operatin g in a radar environment, in controlled
airspace, we expect air traffic control to take care of
us with radar vectoring if a missed approach
becomes necessary. Another reason may be that
under the Australian operational control sys te m
ATC will not clear an aircraft for an approach
when the weather is observed to be below minima;
thus the possibility of a missed approach is
considerably reduced. Outside controlled airspace,
however, we must re member that the
pilo t-in-command makes the decision to attempt an
approach and, if a misse d approach becomes
necessar y, it will be strictly procedural.
Pilot landing expectancy
The re is apparentl y an underlying phenomenon
prevalent in pilots called 'landing expectancy'.
Expecta ncy or set can be defined as an anticipa tory
belie f or desire. Certainly a pilot a nticipa tes he will
land off an approach and he has a desire to do so.
Unfortunately, his landing ex pectancy, which
operates at a subconscious level, may a ffect his
decision-making processes to the point where he
overlooks some safet y procedures.
This phenomenon is derived from experience
and is probably a result of the infrequency of
missed approaches when compared with successful
landings. An individual expectation could result in
the perception of a situation d ifferent fro m the
actual circumstances. Thus a decisio n could be
based on how a pilot would like the circumsta nces
to be rather than what is reality. This can lead to
accidents.
A similar situation ca n exist with air 'traffic
controllers and this will be discussed at a n other
time.
A landing expectancy incident?
The circumsta nces of a recent Austra lian
occurrence suggest that pilot la nd ing ex pectancy
might have been a fac tor. The following situation is
occasionall y encou ntered and worthy of
consideration by all IFR pilots. Study the simplified
landing chart then rea d on.
•
T wo IFR a ircraft were inbound at night to an
aerodro me ou tside controlled airspace. They
ma intained adequate separation during their
d escents to overhead the field and each had elected
to carry out a VOR approach . Special weather
con d itio ns existed wi th the base or the layered
stra tus cloud reported to be 500 feet.
The leading aircraft descended to the initial
ap proach a ltitud e of 3000 feet and the second
aircraft d escended to arrive overhead at 4000 feet.
A fter the first aircraft had left 3000 feet on the
a p p roach , the othe r ai rcraft descended in the
holdin g pattern to 3000 feet.
Because of the low cloud base the firs t aircraft
was u nable to sight the aerodrome at the minima
a nd commenced the missed approach procedure,
on climb to 3500 feet. As the aircraft approached
the Lop of a layer o f stratus, its ligh ts were seen by
the p ilot of the second aircraft which was inbound
in the holding pattern and now at 3000 feet.
RJT liaison res ulted in th e climbing aircraft
maintaining 2500 feet on the missed approach
h eadi ng while th e other aircraft climbed back to 4000
f eet. Both aircraft eventually diverted Lo an alternate
aerodrome after missing out on two approach
atte mpts.
Was the pilot of the second aircraft
subconsciously ex pecting the other air craft to make
a successfu l a pproach and landing? We will never
know fo r su re but it remains a distinct possibility.
T he message fro m this particu lar occurrence is
obvious - wh en an actual instrument approach to
the minima is requ ired at an uncontrolled
aerodrome, a follo wing aircraft sh ould hold at an
altitude which provides vertical se paration above the
lowest holding altitude (or the missed approach
al titude if this is higher) and not descend until the
preced ing aircraft making an approach hp.s
reported 'visual' and its landing is assu red. T h is
procedure is even more valid when the missed
approach track conflicts with the area provided fo r
holding, as in the example described here.
As a broader consideration, we should recognise
the p h enomen on of landing expectancy and
counteract it on a conscious level. T here appear to
be three things a pilot can do in this regard:
-Become familiar with the missed approach
environment. T his can be done in the simulator
where missed approach decisions can be
practised u nder var ied conditions a nd du ring
various pans of the approach profile. Learn what
can and cannot be clone in this environment to
red uce uncertainty and place landing expectancy
in its proper place.
-Prepare for the missed approach as well as for
th e approach. This will help reduce the
uncertainty of 'go' and 'no go' situations.
- Adhere to established procedures with regard to
approach limits and have as many decisions
pre-planned as possible.
T he prudent pilot, th rough adequate planning, is
able to prevent la nding ex pectancy from ad versely
affecting his decision-making while on fi nal
approach, thus improving his own safety as well as
the safety of his passengers •
VOR
ANY PLACE
MNM SAFE ALT 3500 25 NM
USE QNH
APC VOR
3000\ [;?
MNM ALT
0
10 I Aviation Safety Digest 107
NM
5
Aviation Safety Digest 107 I 11
�Peak
The Engine Doctor on gauges
.c
In Aviation Safety Digest 106 we reprinted an article from the U.S. Federal Aviation Agency General
Aviation News concerning fuel consumption and the use of the mixture control. In this issue we
present the follow-up article from the same source concerning the correct use of the engine
monitoring gauges, namely the cylinder head and exhaust gas temperature gauges, and what their
indications mean to the pilot.
Doctor: Well, here you are back again, right on
schedule. I believe we were going to talk abo ut
cylinder h ead te mperature gauges and Owner: Doc, yo u can save your breath to cool your
porridge, as my dad used to say. I've already got a
CHT, and I feel a lot better. I can fine-tune the
mixture without worrying about overheating the
engine, just like you said. Saving me a bundle on
fuel.
Doctor: T hat is not quite what I said. The cylinder
head temperature gauge is an excelle nt instru me nt
for helping to safeguard your engine, but for
fine-tuning the mixture you would need an EGT.
Owner: What is that?
Doctor: The EGT is the exhaust gas temperature
gauge. It's an instrument which indicates the
temperature of your exha ust gas, by means of a
heat-sensing probe in the exhaust stack. Very
simple, really.
Owner: Why would I want to know about the
temperature of my exhaust?
Doctor: Because it is related directly to the
combustion tem perature. And so is the fuel/air
mi xture as we explained before. Lean ing th e
mixture increases combustion temperatures up to
peak; e nriching it brings that temperature down.
T hese temperature changes also show up in the
exhaust gas.
Owner: Are you telling me I went out and bought
the wrong gauge?
Doctor: Not at all. T he CHT is the prima ry
instrume nt - if I couldn' t afford both a CHT and
an EGT ga uge on my aeropla ne I'd choose the
CHT every time. Safegua rding the engine is more
important than saving fuel.
Owner: Can't l use my C HT to lean right up to
peak?
Doctor: Not precisely. Remember, the CHT
m easures the te mperature of the cylinder head which is a mass of metal - not the combustion
insid e the cylinder. It takes a little time for any
cha nge in the mixture - and the combustion - to
1-egister on the CHT. ga uge. We estimate it takes
abou t five minutes for a new temperature point to
stabilise. On the other hand, the EGT gauge, which
has a probe righ t in the exhaust stack, tells you
immediately whether the combustion is at peak
tempe rature, or approaching it, or declining. If you
move the mixture control knob slowly, the EGT
gauge needle will move right along with you. T h e
cruise temperatu re readings range up to
1700 degrees Fah renh eit a nd they are usually
calibrated in increments of 25 d egrees, so
proportionally you h ave a much closer watch on
te mperature move me nt.
Owner: If I had one of those, wh y would I need a
CHT gauge?
12 I Aviation Safety Digest 107
Doctor: T he CHT is the overrid ing instrument.
Whenever it a pproaches redline, you have to enrich
the mixture - regardless of EGT gauge readings
- a nd take other measurements as appropriate to
reduce cylinder temperature: enrich mixture, open
cowl flaps, reduce power, or any combination of
these. We like to keep th e CHT in the green arc at
all times - between approximately 200 and
400 degrees Fahrenheit. If it gets much hotter, you
could d amage valves or fou l the spark plugs. If it
gets much cooler, you are also apt to foul the plugs
- especially with the high lead content in some
fuels we use today. Any time you observe a
temperature trend in either direction, ,without a
change in mixture or power setting, you sh ould
suspect a n engine problem.
Owner: Are you saying that the CHT is just for
protecting the engine, and the EGT is for accurate
leaning?
Doctor: Well no, not exactly. T he EGT gau ge can
be used for fine-tuning the mixture, of course. But
it can also give you a n early warn ing of engine
trouble, and help you sometimes to cope with that
trouble in flight. T~ is is especially true if you go to a
multi-probe installation , with a heat sensor for each
cylinder.
Owner: Why? Don't they all run at the same
temperature.
Doctor: Oh, no. Even under normal conditions the
cylinder temperatures vary appreciably. In a light,
fuel-injection engine like yours they may vary as
much as I00 degrees Fahre nheit just d uring cruise.
With a small, carburettor-type engine, that
difference could amount to 200 degrees Fahrenheit.
One reason is that fuel flow is not precisely equal in
these small e ngines and usually the cylinder getting
the least a mount of fuel will ru n hottest.
That, incidentally, is why we see a limited gai n
from installing a single-probe EGT gauge in these
engines - the variance is too great. A U we can
really do is adjust the mixture for whatever is th e
hottest cylinder at the time. But with a multi-probe
system we can spot trouble in a hurry because we
know - from prior calibrations - just about what
temperature to expect in each cylinder. The CHT
can only tell us about an overall rise or decline in
engine temperature (unless it too has probes in all
cylinders, which is not a common installation). T he
~ulti-probe EGT gauge will tell us if the change is
m all of the cylinders, or in certain cylinders only.
In flight it may even help the pilot determine what
adjustments he could make that would enable him
to land safely. You look sceptical, but listen to this.
Only last month a young p ilot I know h ad a
forced la nding that turned out rather badly and was
quite unnecessary. H e was flying in a single-e ngine
retractable something like yours and was already
EGT
(,)
...
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17·8
15·2
Fuel consumption -gallons per hour
Chart shows the relations hip between mixture
for a
260 hp engine at 10,000 feet . Lea ning
~
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13·2
11·0
9·3
fuel
p ast
l etti~g down for the approach when the engine quit
o n him. just faded away. He had noticed a decline
in CHT just before he red uced power and he
suspected carburettor ice. H e pulled on the
carburettor heat wi thout result a nd tried to restart
but nothing doing. H e attempted to stretch his glide
to the runway but ran out of altitude and had to
put it down in an open field. Unfortunately he was
too busy to n otice the power cable in time, and
flipped over. Plane was a total wreck, and the pilot
spen t an uncomfortable mo n th in the hospital.
In the accident inves tigation we found dried leaf
particles that almost totally obstructed the strainer
in the fuel tank h e was using. Now with a n EGT,
the restricted Fuel flow would have sh ow n up
immediately as a sharp temperature change on the
ga uge. T he earl y warning would h ave given him
time to consider his problem a li ttle more calmly,
and to solve it readily by going to alternative fuel
ta nk selection and setting course for the nearest
airport. Pity. Practically a new aircraft.
Owner: Yeah . But maybe th e pilot didn't know that
much abou t e ngines. We're not all natu ral-born
mechanical geniuses, you know. Maybe the
equipment isn't as good as it should be. How did
the pilots make out in the old days, when all they
had on th e panel was a compass and a laundry list?
Doctor: T h ey landed hard a nd often. T heir
equipment wasn't as good as what we have now , by
any means. I n th e reall y o ld days eve ry pilot was
something of a mechanic, a nd there was a lot of
open land you could put d own in , clean off the
consumption and
'pea k ' to save
T
exhaust gas temperature
fuel is not recommended
plugs, re-set the timing or whatever, and take off
agai n . Not many places when~ we can do that a ny
more.
Owner: So what's the answer?
Doctor: Keep the aircraft fl yin g between airports.
Any reasonabl y priced instrument - and that
includes the EGT - th at will help me keep the
propeller turnin g over is worth its cost because it
makes my flyi ng more relaxed - and safer.
Cheaper too, in the lo ng run.
Owner: All these gauges may mean something
speci~l to a p~-o. like you , but what abo ut us pure
and sim p le pilots. You don't want us doctoring a
sick engine up in the sky, do you?
Doct~r: Not if you can help it. But any pilot, pure
and simple o r otherwise, is liable to run into a n
inflight situation with a faltering e ngine when he
has ~o make a critical decision abo ut going on,
turmng back, or landing rig ht away. The safety of
all on board will depend on his decision. T h e more
knowledge you h ave about what is going on inside
the firebox, the better your chances of making a
good decision , no matter how rudimen tary your
knowledge of engines.
The 'automatic rough ' we often think we hear
~iver _ope_n water. or high mountains may be
1m agm~ t1on , or 1t may actually be the beginnin gs of
a n en gme proble m . How can you tell? You need n't
wait until an engine starts shaking you a part before
~ou decide that some thing is wro ng. Engines are
hke people: the first measurable sign of trouble is
usually a n abnormal temperature. If you have an
Aviation Safety Digest 107 I 13
�20°c
~
~
On hotter days, lower
~
~
EGT is needed to keep cy linder hea d
EGT gau ge and especiall y if you have multi-probe
sen sors - you may be able to spot trouble coming,
upstream so to sp eak, before the cylinder head
temperature moves o ut of the normal range . An
unusua l rise of 50 deg rees Fa h re nhe it on the EGT
gauge, with no ch ange in power o r mixture, may be
wort~ paying attention to, pa rticularl y if it occu rs
o nly m one or some of the cylinders. You would
want to keep a dose eye on those cylinde rs, a nd if
they continue to h eat up you would know yo u h ave
a real proble m. '
Owner: You mean long before it showed up o n the
C HT?
Doctor: If it is a slow te mpe rature rise, certainly. A
slow r~se in one cylinder may take quite some time
to register o n the C H T , a nd it won 't show at all on
the EGT single probe unit if the probe happens to
be in the stack of a cylinder that is function ing
normall y.
Owner: So in that case I would n 't know abo ut the
problem until the engine actuall y started to misfire ?
Doctor: Rig ht. And by this time you could be a long
way from a la nding field.
Owner: Wh a t about a sudde n jump in tem p erature,
doesn 't the en gine start runnin g really rough rig ht
away?
Doctor: It can h appen very fast, but with a
multi-probe EGT you could h ave some ad vance
warning . Might give you o nly a few extra seconds
before having- to shut down and call for help, but
over wild terrain o r rough waters those few seconds
can mean a diffe re nce of life or death.
<?wne_r: What the g~ u ge is doin g for you is bu ying
time, 1s tha t right?
Doctor: In some cases, yes, but not always. If the
probl~ m is c<?nfined to some of the cylinders only,
th er~ 1s nothmg you can do in fli gh t but look for a
l~ndm g fie ld. But if th ere is a gene ral tempe rature
n se, yo u can try operating on the left or right
magneto only. En r iching the mixtu re may help
lower _tem per a tures, likewise opening cowl fl aps or
reclucmg power , even if both mags are in poor
shap e.
o _w ner: ~oes the exhaust tem perature always go u p
with e ngm e trouble?
Doctor: Most of the tim e, but not always. Whe n you
.sec a drop m te m pera ture the situation is rarely
14 I Aviation Safety Digest 107
-1s 0 c
~1:i Lical . or
temperature in the green
beyond in fligh t remed y. Carburettor
1c111g, fa ul ty valves or certain igniLion problems
could p roduce a drop in combus tion and exh aus t
gas. temperatu res. For example, if you 've j ust had
mamtena nce d one on your ig ni tion syste m , a
temperature decline could mean the ignition is too
advanced. Noting whether operating on one mag. or
the other brings the reading back towards normal,
and which cylinde rs are affected , will save your
mechanic a lot of time in diagnosing th e problem,
once you get back on the grou nd.
Owner: I s that what yo u meant, a while back, whe n
you said these EGT gauges could save money in the
lo ng run ?
Doctor: Partl y. Any instrum ent th at helps you keep
yo'.-1r e ngine from overheating or overcooling is
gomg to kee p d ow n your re pair bills. The EGT
gauge is especially h elpful on descents, wh en lower
power settings a nd en rich ed mix tures can easily
lead ~o excessively low combustion temperatur es.
! his 1s a common cau se of spark plug fouling , and
It can be avoided if yo u watch the gauges on the
way d own .
Owner: Do you recomme nd o ne particular brand ot
EGT gauge?
Doctor: N o , th a t depends on you . T here are several
that are built in accordance with FAA Technical
Stan dard O rd ers - TSO'd , as they 5ay. They are
basicall y the same but with certain individual
featu res. Some have absolute tem perature read ings,
and some h ave only relative indications. Some have
a low r ange for idling, some do not. Some have an
aural warning, for overheatin g, some have warning
lights, some have neithe r. You pay your money and
you ta ke your choice.
Owner: W hat happens if the gauge itself is off?
H ow would I know?
Doctor: T h ey are designed to give o nl y an
a bnor mall y low reading if they become defective.
C heck an y low readin g again st your CHT gauge,
and rely o n the la tter.
Owner: You mean, fo r getti n g out of the aircraft?
Doctor: I beg your pardon ?
Owner: Just m y little j oke .
Doctor: U h , yes, I see. Ha! Next patient, p lease!•
Advice about cables from a LAME
I n several recent editions of the Aviation Safety Digest
yo u h ave encou raged those of us in aviation to
contr ibut_e and share our experiences. Accordingly
several pilots have done so. For some time I have
been considering ta~ ing up the pen for engineering
on a particularly senous, though sometimes
underestimated subj ect. J ust this a fternoon I found
a nother u nserviceable control cable using the
procedure which I will describe and this finally
prom pted me to pick up my pen.
As a lice.ns~d aircraft maintenance engineer in
general a viat10n I am confronted on a daily basis
~ith decisions which to no small degree are often
m fluenced by that enemy of us all - cost. Quite
often a discussion about a doubtful component
mighr go like th.is:
'] ust how bad is it?'
' Is it repairable or must we replace it?'
'Will it last another 100 hours?'
'Okay, we'll repair it this time and have a
re p lacement ready at the nex t periodic', or,
'We'll ~eplace enou gh to make it safe and replace
t_he asso~ia~e~ hardware progressively over the next
few p enod1c m spections'.
The above will affect us in many ways. Some may
be aghast? others a m used, but it is a fairly realistic
presentat10n of.what does hap pen, which brings me
to the reason for writing this article. One area of
general aviation main tenance that concerns me
gre.atly is cable ins pections. Being airline trained I
believe that the only satisfactory method of
inspecting cables is to remove them to a well lit, if
not daylight area.
However a fter being in general aviation for
several years I have found that it is more usual for
the cables to be merely slackened off, rolled on the
pulle y (whic h often is in a narrow wing root, under
the floor , behind a cabin headlining, etc.) and
inspected in situ.
·For the last two a nd a half years I have worked in
the servici"ng division of a large, light aircraft
d istributor, and in that time have had several
instances wh ere I had to thank m y airline training
~nd ge?erally cautious nature. For during maj or
mspections, wh en faced with the decision
concerning cable inspections I chose to remove to
da_ylight and on three aircraft fo und that primary
fligh t control cables were unserviceable.
also had an unserviceable aileron balance cable as a
result of a seized pulley.
~nother aircraft of a similar, though larger,
vanety undergoing its first major since C of A had
two unser viceable rudder cables. This was
par ticularly inte~esting ?ecause the unstranding of
b?th cables was in the middle of nowhere ie, some
d istance from any pulley, fairlead, fuselage former,
etc. I could only conclude that the failure of the
cable was caused by e ither excessive system tension
or a defective cable length at manufacture. One
thing though was definite: it would not have been
discovered had the cable not been removed fro m its
installed location.
I trust those reading this article have received the
thrust of its m~ssage . Whether they be LAME,
operator or private owner let us all appreciate that
the extra dollars spent for a professional job,
properly done, are worth it in consideration of the
additional degree of safety.
Comment
The Department of Trans port has observed a
disturbing increase in the incidence of problems
with control cables over the last few years. These
problems have included in flight failures of cables
caused by excessive wear and incorrec t installation
incorrect handing, misalignment of trim tab cable'
runs, e~c. The inspec~ion of cables has already been
the su bject of DoT A1rworthiness Advisory
Circulars No 4 1 May 1970, No 61 February 1972
and No 106 November 1978. I t is n ow intended to
specify mo~e string:ent mandatory inspection
coverage of cables 111 appropriate sections of Air
Navigation Orders.
Pilots are once again urged to pay more attention
to their pre-flight checks of control systems for
smoothness of operation, excessive friction,
slackn ess, noisy operation a nd movement in the
correct sense •
. On o.ne a~rcra~t'. ~ndergoing its thi rd major
mspection smce mmal C of A, both the forward
stabilator cables were unserviceable because of
brok_en s~rands - not at a pulle y or sharp change
of d1rect1on as you would expect - but at a fairlead
in a straight r un. The fairlead's location was such
that detection during a regular, periodic inspection
would h ave been highly unlikely. The same aircraft
Aviation Safety Digest 107 / 15
�ll
Manoeuvring speed and structural
failure
Pla nning to fl y to Clo ncurry, Q ueensla nd , with
several friends to sp end a few days on a fishing and
ca m ping holiday, a pilot who was also part owner of
a Cessna 2 10 tele phon ed the Arch erfield brie fin g
office early o n th e Satu rday mornin g o f a long
wee kend to notify flight plan derails. T he fli ght was
to be non-sto p fro m Redcliffe direct tu Cloncu r r y,
with an ex pected d e parture time of 0730 hours, a
cruising a ltitude of 85 00 feel a nd an estima ted
£ligh t time o r 289 mi n utes. The pilot had calcula ted
the a ircraft's total fuel e ndura nce as 396 minutes.
The flight p la n indicated th e aircraft would be
operating VFR a11d the meteorological forecasts th e
pilot obta ined p redicted fin e conditions over the
proposed rou te.
Four ad ult passengers and o ne child we re to
travel in the a ircraft, a nd at about 0700 hou rs the
pilot a nd passc11gers a rrived a t Redcliffe
aerodrome. T he pilot re fuelled th e a ircr aft and ,
thou gh it is not know n fo r certain , he most likely
fi lled the ta n ks to maximu m capacity. H e also had
the e ngine oil filled to ca pacity fo r the p roposed
five hou r no n-stop night and the n su pervised the
loadin g of ca mping equipmen t a n d other pe rsonal
effects. When the aircraft tax ied ou t a l Redcli!Te,
the gross weigh t was at abou t the max imum
permissible:.
Wh ile tax iing fo r take-off, the pilot established
rad io communication with Br isba ne on the
apprnp riate area freque ncy and , at 0809 hou rs, he
16 I Aviation Safety Digest 107
re ported air borne. Twenty th ree minutes later , on
ch anging frequ ency, he advised he was cruising at
8500 feet and subseque ntl y, as the fli gh t
progressed, he made scheduled position reports, al1
of which were of a routine na ture.
The ground speed achieved by the aircraft was
slightl y lower tha n pla nned a nd whe n th e a ircraft
reach ed a position 50 km no rth of Lo ngrcach it was
16 minutes behind the flight pla n estima te. At 1255
hours, the pilot called Mt Isa on H F a nd re po rted :
'We're one zero miles north -west Mc Kinlay a nd
leaving eight five zero zero on descen t Cloncu rr)'.'
T his was acknowledged by Mt I sa and was the last
known transmission fro m the a ircraft.
T he a ircraft was later obser ved approaching,
fro m the directio n o f McKi nlay, a road constru ctio n
cam p on the McKinlay lO Clo ncurry road at a n
estimated he ight of abo ut 1500 feet. T h e speed of
the aircraf t a l this time was esti mated lo be at least
the norm al cruising speed . l t was in a normal
attitude and th e engine noise seemed normal.
Suddenly a series of loud sounds, similar lo those
produced by a misfiri ng e ngine, was heard a nd a n
object was seen to sepa rate from the a ircraft. The
aircra ft, which had comm enced a turn to th e right,
then e ntered a steep s pira l d ive du rin g which white
f uel va pour was seen LO issue from one of the
win gs. T he spira l d ive con tin ued until the a ircraft
stru ck the ground a t high speed in a steep nose
d own attitude some 1280 me tres north of the
construction camp. When two me n fro m the camp
l·eached the crash site, they fo und the a ircraft had
been totall y de molish ed a11d a ll on board had been
killed .
Subseque n t exam ination of the a ircraft wreckage
was hampered by the gross d egree o r d isintegration .
No evidc11ce was fo und of a n y pre-existing defect
or malfunction which might have con tr ibuted to th e
accide n t. T here was no fire. A two- metre outboard
portion of the lef t wing was located 7 10 metres
south-west of the main wreckage a nd a s ma ller
portio n or th at wing was loca ted 6 1 metres west or
the la rger portion . It was esta blish ed tha t the left
wing fa iled in flight in a man n er consistc11t with the
aJ?plic:arion o f a nose clow n torsional loadin g lO the
wtn g.
T he operatin g li mitations sectio n in the nigh t
ma nua l for this aircraft specified a manoeuv ri ng
speed of 1 18 knots indicated airspeed (I AS). T he
ma nua l defin ed the ter m 'ma noeu vring speed' as
'maximum fo r ma noeuvres involving a n ap p roach
to stall conditio ns 0 1· foll a p p licatio n of the p rimary
fl ight controls.' The normal cruisi11g speed of this
model Cessna 2 10 is considerably i11 excess of the
ma noe uvring speed. A ra pid ap plicatio n of a la rge
amount of r igh t wing d own a ileron control at
speeds in the vicinity of the norma l cruising speed
could produce torsional loading in th e left wing in
excess of the d esign stre ngth of the wing a nd result
in wing fa ilure consiste nt with th at which occu rred
in this accide nt.
T he en route weathe r e ncou11tcred b)' the aircraft
was consiste nt wirJ1 the fo recast obta ined by the p ilot
a nd cond ition.> at the time of the acciden t were fine
a nd clou dless. T here was nothing to suggest that the
a ircraft encou ntered a bnorma l turbule nce at a ny ti me
du rin g the fli ght. or was there a n y evidence to
indicate that the p ilot suffered any incapacitation
which would have affected his ability to control the
a ircraft. The a rea in the vicinity or th e road
construction cam p was the habita t o f numerous
kite- hawks bu t th ere was no evide nce of the a ircrarr
coll idin g with birds o r of the pilot needi ng to ta ke a n y
action to avoid the m.
Alth ou gh the circumsta nces which led Lo a ra pid
applicatio n of a large a mou n t of a ile ron control at
or nea r th e cn1isin g speed arc nor known , the re is
no d ou bt tha t the Ccss11a was su ~ j ected lo stresses
in excess of the d esig n limits as th e resu lt of such a
control input.
As aeropla nes op er ate over a wide ra n ge o f' weigh ts
and speeds a nd in a g1-eat variety of llig ht cond itions,
th e str uctu re. must be d esigned to cope with the widest
possible ra nge of operating conditio ns the aeropla ne is
likely to e ncounter. T he bou ndaries o f the flight
e11velope are esta blished by a series of poin ts
represe ntin g values of load factor (g) a n d airspeed.
T hese poims d efine the basic !lig ht design cases fo r th e
aeroplane.
T he max imum load factor which may be a pplied
to an aeropla ne under stipu lated condi tions withou t
ca using permane nt defonn atio 11 of th e structu re is
ter med the 'limi t' load factor. T he p oint beyond
which the structure may actuall y fa il is known as th e
d esign 'ultimate' load a nd aeropla ne design
requiremen ts de ma nd that the ultimate load factor
be a t least 150 per cent of th e li mit load factor.
O ne of th e basic design points 01 1 a11 aeropla ne's
structural e n velo pe is termed the 'ma noeuvring
speed.' This is th e highest speed at which the
aeroplane will stall before the certificated maxim um
limit load factor is exceeded. T he speed is thus
establish ed primarily as a fu nction o r elevator
control but is a lso the speed at which the structure
is j ustified for full d eflection of the other flight
crnllrols - the a ile rons a nd the rudd er.
To ensure the load s imposed 011 a n aeropla ne d o
not exceed the a p p roved limit load facto rs, pilots
are required lo operate the ir ae roplanes i11
accordan ce with the operating limitations specified
in the flight ma nua l a nd the owner's ma nua l. These
ma nuals sp ecify maximum speed s such as flap and
undercarriage exte nsion speeds, cruisin g speed and
ma noeu vring sp eed . Values of manoeuvrin g speed
are usua ll y also called u p as recom mc11dcd
tu rbule n t a ir penetration sp eed s.
O ver recent years, the manufacturer s of general
aviation aircraft in the U nited States h ave
introduced a sta nda rdised , compreh e nsive owner's
or pilot's opera ting h andbook based o n a format
recommended by the General Avia tion
Manufacturers' Association . Althou gh at th e time of
this accide nL, the handboo k in effect fo r the
particula r mod el Cessna 2 10 involved was the
s maller , earlier versio n, the ha11 dboo k subsequently
p repa red by the ma nufacture r for late r p roduction
aircraft - but still of the sa me model - specifies
ma noeuvring speed s for va rious weights with the
caurio11 'Do not make f'u ll or abrupt control
moveme nts above this speed.' T h e speed s a nd
weigh ts arc 3800 lb ( 17'2.:1 kg) = I 19 knots I AS
3 150 lb (2043 kg) = I 09 knots I AS
2500 lb ( 1 135 kg) = 96 knots I AS
Ma ny pilots ma y be surpr ised that th e maximum
safe ma noeu vring speed decreases, in some cases
quite marked ly, as the aeroplane gross weight is
red uced. Basicall y, for a give n speed a nd con trol
movemen t the cont rol su rface applies a load that is
inde pendent o f aero plane weig h t, bur the lighte r
the aeropla ne the mo re vigo rously it res ponds a nd
this respo nse ind uces hig her stresses in th e
airfra rnc. A ligh t!)' load ed ae rop la ne is more critical
in te rms o f coarse control a p plication than the sam e
aeropla ne op erating near its maxim um take-off
weigh t.
Airspeed indicato rs arc colour coded to show the
never exceed speed a nd the cau tion, normal operating
a11d flap operating ra nges. Ma noeuvr in g
speed, on the other hand , is not marked on the
ind icator dial but is called up o n a separate cockp it
placard which may be some d istance fro m the
instru men t. It is possible that a pilot, u n~wa re or
the im portance of the ma noeu vr ing speed
limi tation , coul d well be lulled into thinking that, so
long as h e is operating in the g ree n a rc on the
airspeed indicator, the aeropla ne will stall before
structural o verloading occurs and consequently no
serious over-stress in g o f' the structure is possible.
T his, of course, is in correct; ma ny types of light
aero pla ne., es pecia ll y high performance models su ch
as the Cessna 2 10 , have a normal cruising speed
insid e the green arc bur well in excess of the
specified manoeu vring speed . The p ilot's operating
Aviation Safety Digest 107 I 17
�handbook for the aeroplane involved in this
accidenl indica,tes that, at the maximum take-off
weight and 75 per cent power, a cruising speed of
163 knots can be expected at 2000 feet in standard
atmosph eric conditions. This is 44 knots above the
ma noeuvring speed at the maximum weight, and as
much as 67 knots at light weight.
For Lhese types of aeroplanes therefore, the
coarse or rapid application of full control deflection
at speeds in the vicinity of the normal cruising
speed will lead to almost certain structural damage
a nd possibly total failure. At even higher speeds,
such as on descent, less than full control deflection
could cause the same damage. An overload
condition and/or the dynamic effect of ver y rapid
control application could resu lt in structural failure
at a lower speed.
The refined design techniques used for modern light
aeroplanes mean that structural margins of safety have
been reduced to a minimum. Because of this, only a
slight degree of mishandling may cause damage or
stru ctural failure in these aeroplanes, even under
normal operating conditions. T his is especially true of
the more sophisticated, high performance types,
which require the very highest standards of
airmanship and the strictest possible ad herance to all
specified limitations•
In brief
At a country aerodrome in South Australia, the
pilot of a Piper Seneca was preparing to take a
gro up of Boy Scouts on a scenic flight as pa rt of
their Air Activities Course. Earlier in the da y, the
pilot and a small group of Scouts had walked the
le ngth of the strip to straigh ten some of the tyre
marke rs and remove an y tobacco bushes. Nothing
unusual was noticed during the inspectio n.
The aerodrome was also used for glider fl ying
and at the time a glider was operating on winch
la unches from a cross strip. Before starting up, the
pilot of the Seneca checked that he would be clear
of the glider, which was airborne, and that the
launching cable h ad been wound back on the winch.
After starting the e ngines, he taxied out and lined
up but in the meantime the glider had returned to
the circuit and was now landing on the cross strip,
so the pilot waited until it had passed the
intersection and then began to take off.
H e ope ned the throttles wide and after a grou nd
roll of about 150 metres, a nd at a speed of about 30
to 35 knots, he heard a loud ba ng as something hit
the windscreen and h e saw a piece of fibreglass fly
up from the nose. Thinking the aircraft had hit a
sto ne, he closed the throttles and the aircraft rolled
to a stop about three-quarters of the way along the
strip. H e shut down both engines and then saw a
le ngth of wire hanging from the left propeller.
After removing the wire, the pilot taxied the
aircra ft slowly back to the hangar. Shortly
a fterwards, a party of Scouts went out to ch eck the
strip and returned with two more lengths of wire,
each about 30 metres long, which they h ad found
near the intersection of the strip the Seneca was
using a nd the strip being used by the glide r.
The wire proved to be lau nching cable and ,
during th e attempted take-off, it had been caught
up in the aircraft's nose landing gear. The flailing
cable h ad nicked both propellers, slashed the left
18 I Aviation Safety Digest 107
Channelised attention
•
engine cowling, th e nose and the nose locker door,
and de nted both nosewhecl doors. The gliding
operations log showed that, on the morning of the
previo us day, the winch cable had broken during a
launch and it was this break which probably
accounted for the pieces of cable being found
where they were. Although the retrieval crew
recovered both ends of the cable, it seems that the
cable had broken in at least two places and the
piece or pieces which had come away completely
had fa llen alongside the intersection of the two
strips and re mained unde tected until snagged by
the Seneca's nose wheel.
T here are several human errors associated with
this occurrence but it seems the pilot did all he
could reasonabl y be expected to do in the
circumstances. He was unawa re of the cable break
the previous d ay, the broken section of cable was
not readil y discernible, and the pilot had made a
reasonable effort to inspect the proposed take-off
area. On the other h and , at th e time of the
accident, there was no procedure at the aerodrome
for carrying out a routine dail y inspection of the
other strips before operations commenced a nd the
retrieval crew had not been super vised during the
cable recovery the previous day.
As a result of this accident, procedures have been
introduced a t this particular aerodrome which
require a daily inspection of every strip before
operations commence. But the lesson for pilots is
clear - nothing should ever be ta ken for granted .
A mixture of glider and power operations requires
extra caution at any time - especially when winch
launches are being used - a nd it is essential that
pilots realise tha t the res ponsibility for ensuring the
surface of a strip is clear of obstructions rests solely
with themselves•
A factor often apparent in aircraft accidents is the
pilot's pre-occupation with one particular aspect of
a fligh t to the exclusion of oth er tasks vital to the
safe ty of the operation. This 'cha nnelised attention'
is frequentl y evident in the various forms o f
competitive fl yin g, where concentration on the task
in ha nd and the desire Lo succeed ca n be so
overwhelming as to override good judg ment and
the fundam entals of sound airma nship.
An example of this can be seen in the
circumsta nces of an accident involving a n
ex perienced glider pilot compe Ling in the
Australian national gliding champio nships. O n the
third clay of the competition s, a fo ur-leg cross
country task had been set. The pilot completed the
first three stages without incid ent and on the fourth
leg, abou t 30 km north of the destina tion
aerodrome, he decided to a uempt a final glide
direct to the finishing line.
The glider tracked straight towa rds the
aerodrome on a southerl y heading but, late on final
approach , the pilot saw the glider was not going to
make the distance. He noticed a paddock 011 the
northe rn boundary o f the aerodrom e a nd though it
appeared only marginally suita ble, h e realised h e
would have lo put the glider down. Planning to
land in to the west, the pilot continued the approach
on a heading towards Lhe aerodrome a nd , at a low
height above the ground, he banked the glide r to
the right. T he glider h ad turned only a few d egrees
however , before the right wing struck a low contour
mound running east-west across the paddock a nd
the glide r ground-looped to the right.
While travelling in a southe rly d irection, the
glider slid sideways into the nex t contour mound
and the rear fuselage broke in two. The glider
bounced to a halt a nd Lhe pilot cla mber ed from the
wreckage uninjured.
The pilot said later he probabl y became
preoccupied on th e final glide with his attempt to
make a straight-in approach to the aerodrome and
it was not until too late he saw that the paddock h e
h ad selected was unsuitable. Obviously whe n h e
began the final glide he was too low to reach the
aerodrome but by the time he finally realised this
he was committed to putting the glider on the
ground as best h e could.
Probably, h ad the pilot not been subject to th e
pressure of competition, h e would have adopLed
normal out-landing procedures and left hi mself
plenty of time to select a field that would have
permitted a safe la nding. It seems his d etermination
to complete the tas k coloured his judgment to the
ex tent th at the glider virtually Oew into the ground.
The pilot was no d oubt aware of the dangers in
trying to stre tch the glide, but seemingl y failed to
recognise th e developing hazard until too late. To
e nsure competitive fl ying is based on sound
airmanship and rem ains within the capabilities of
both pilot and aircraft, the will to win must be
tempered with ma ture judg me nt a nd a proper
sense of p~iorities •
Aviation Safety Digest 107 I 19
�Reluctance to accept the emergency situation
A pilot who allows his mind to b ecome paralysed at
the thought that his aircraft will be on the grou nd
in a ver y short time, regardless of what he d oes or
hopes, severely handicaps hi~self in the handling
of the emergency. An unconsciou s desire to delay
this dreaded moment may lead to such er rors as:
failu re to lower the nose to maintain fl ying speed,
failure to lower collective to maintain rotor rpm (in
h elicopters) , d elay in the selection of the most
suitable touchd own area with in reach, and
indecision in general. Desperate attempts to correct
wh atever went wrong, a t the expen se of aircraft
control , fall into the same category.
Emergency l~nding techniques in
small fixed-wing aircraft
A special study prepared by Gerard M. Bruggink, Air Safety Investigator with the Bureau of Aviation
Safety, National Transportation Safety Board, U.S.A.
The National Transportation Safety Board
The National Transportation Safety Board was
created by the Department of Transportation Act of
1966. It is headed by five Mem bers appointed by
the President and approved by the Senate.
T h e Safety Board was established to improve
safety in United States transportation extending to
civil aviation, marine, pipeline, railroad , and
highway modes of transportation. It has broad
powers in the investigation and cause determination
of transportation accidents. Through
recommendations it is continuously involved in
accident prevention and safet y promotion. It is also
responsible for reviewing on appeal the su spension ,
amendment, revocation , or denial of any certificate
or licence issued by the Secretary of Transportation
or an y modal Administrator.
In the field of civil aviation , the Safety Board
conducts its own investigations of all air carrier and
air taxi accidents, accide nts involving large aircraft,
mid air collisions , and most fatal accidents. The
Federal Aviation Administration , under delegation
from the Safety Board, investigates all othe r
accidents; however , as required by the Act the
Safety Board determines the cause of all aircraft
accidents and reports the accidents to the public.
As well as prepa ring reports of a ircraft accidents,
the Safety Board underta kes special studies of the
many factors involved in aviation safety.
This study consolidates the lessons learned from
past emergency landing experience in small,
fixed-wing aircraft. The guidelines that are
presented apply to the more adverse terrain
conditions for which no practical training is
possible. T he need for this undertaking became
apparent from the Safety Board's statistical data
which showed that about 25 per cent of all ge neral
aviation accidents are associated with emergency
landings.
It appears that the reliability of the mode rn
aircraft plays less of a role as a cau sal factor in
emergency landings than pilot-induced factors su ch
as flight planning 1 fuel manage me nt, and marginal
weather. This comme nt is not intended as a
re flection on the quality of training schools and
regulator y provisions. The nature of general
aviation is su ch that most pilots are on their own,
once th ey are certificated; this means that they gain
most of their later experience on a trial-and-er ror
basis. Therefore, it is not unusu al for a general
aviation pilot to find himself in situations where his
experience level provides no alterna tive but an
emergency landing . Unfortunately, so much stress is
being p laced on 'a suitable landing area' that some
pilots will not even ente r tain the thought of a
precautionary la nding unless they can save the
aircraft. Too many fatal weather acciden ts, classified
20 I Aviation Safety Digest 107
as 'mainta ined VF.R in IFR conditions', undoubtedly
resulted from d esperate attempts to get through
because the underlying terrain did not fit th e pilot's
mental picture of an emergency landing area.
It is the purpose of this stud y to explain how
almost an y terrain can be considered suitable for a
survivable crash landing if the pilot knows h ow to
use the aircraft structure to protect himself and his
passengers. Hopefully, this knowledge will increase
the number of those who can walk away from a
difficult situation and benefit from th e experience.
The guidelines in this study arc intended to
supplemen t rath er than replace the emergency
instructions in textboo ks and aircraft owners'
manuals; in case of conflict, th e mairnfacturer's
recommendations sh ould be followed.
Types of emergency landings
For the purpose of this stud y the differen t typ es of
emergency la ndings ar e d efin ed as follows:
Forced landing. An immediate landing, on or off
an aerodrome, necessitated by the inability to
continue fu rther flight. Typical example: an aircra ft
fo rced down by engine failure.
Precautionary landing. A premeditated landing, on
or off an aerodrome, whe n further flight is possible
but inadvisable. Examples of conditions that may
call for a precautionary landing: deteriora ting
weather, being lost, fuel shortage, gradually
developing engine trouble.
Ditching. A forced, or precautio nary, la nding on
water.
A precautionary landin g, ge ne rally, is less
hazardous than a forced la nding because the pilot
has more time for terrain selection a nd the
p lanning of his approach. In addition , he can use
power to compensate for errors in judgm cnt or
technique. Unfortuna tely, too man y situatio ns
calling for a precaution ary landi ng a re allowed to
develop into immediate forced landings when the
pilot uses wishful thinkin g instead of reason,
es peciall y when d ealing with a self-inflicted
predicame nt. Such thinking probably p layed a role
in some of the fatal acciden ts attributed to
continu ed VFR flight into marginal weath e r. A
low-fl yi ng pilot who is trapped in weather and does
not give a ny tho ught to th e feas ibility of a
precautiona r y landing, accepts a n exu-emely
hazardous alternative: in advertent flight into a n
obstacle. H e can improve his cha nces to sur vive a n
uncontrolled encounter only by timely slowing
down.
Psychological hazards
T h ere a re severa l factors that may in terfere with a
pilot's ability to act promptly and prop erl y whe n
faced with an e mergency:
Desire to save the aircraft
A pilot who has been conditioned during his
training to ex pect to find a relatively safe landing
a rea, whenever his instructor closed the throttle for
a simulated forced landing, may ignor e all basic
rules of airmanship to avoid a touchdown in terrain
where aircraft damage is unavoidable. T ypical
consequences: making a 180 degree turn back to
the runway when available altitude is insufficient;
stretching the glide with out regard for minimum
control sp eed in order to get into a better-looking
field; accepting an approach and touchdown
situation that leaves no margi n for error. The
desire to save the a ircraft, regardless of the risks
involved , may be influenced by two other factors:
the pilot's financial stake in th e aircraft a nd the
certainty that an undamaged aircraft implies no
bodily harm. As will be explained in this study ,
there are times whe n a pilot should be more
interested in sacrificing the aircraft so that he a nd
his passengers can safely walk away from it.
Undue concern about getting hurt
Fear is a vital p art of our self-preservation
mechanism. However, when fear leads to panic we
invite that which we want most to avoid. A pilot
who allows himself some choice in the selection of a
touchdown point for a full y controlled crash has no
reason to despa ir. The su rvival records favour those
wh o maintain their composure and know how to
apply the general concepts and techniques that have
been d eveloped through out the years.
To summarise the role played by psychological
hazards: it appear s that the success of an emergency
landing under adverse conditions is as much a
matt.er of the mind as of skills.
..
Basic crash safety concepts
A pilot who is faced with an emergency landing in
terrain that makes extensive aircraft damage
inevitable should keep in mind that the avoidance
of cras h injuries is lar gely a matter of:
-Keeping vital structure (cockpit/cabin a rea)
1-elatively intact by using dispensable structure
(wings, landing gear, fuselage bottom, etc.) to
absorb the violence of the stopping process before
it affects th e occupants.
-Avoiding forceful bodily contact with interio r
structure.
Energy absorption
T he ad vantage of sacrificing dispensable structure is
demonstrated d aily on the high ways; a head-on
car impact against a tree is less hazardous for a
properly restrained d river than a similar impact
against the driver's door. Accident experience shows
th at the extent of crushable structure between the
occupants and the principal point of impact on the
aircraft has a direct bearing on the severity of the
transmi tted crash forces and, th erefore , on '
survivability.
Dispensable aircraft structure is not the only
available energy absorbing medium in an
emergency situation. Vegetation, trees, and even
man-made structu res, may be used for this purpose.
Cultivated fields with dense crops, such as mature
corn and grain, are almost as effective in bringing
an aircraft to a stop with repairable damage as an
emergency arresting device on a runway. Brush and
small trees provide considerable cushioning and
braking effect without destro ying the aircraft. When
dealing with natu ral and man-made obstacles with a
greater str ength than the d ispensable aircraft
structure, the pilot has to p lan the tou chdown in
such a manner that only non-essential structure is
'u sed up' in the principal slowing down process.
Occupant restraint
The second req uiremen t - avoiding forcible
contact with interior structure - is a matter of scat
a nd body security (seat belt and shoulder harness) .
Unless the occupant decelerates at the same rate as
the structure surrounding him, he will not benefit
from its relative intactness but will be brought to a
stop in th e form of a so-called second collision . In a
case of partial restraint, such as the u se of a scat
belt only, the same reasoning applies to the
unrestrained body portions. A classic example in
this respect is the frequency of head and chest
injuries of car occu pants who j ack-knife over the seat
belt in a severe front-end collision. The same injury
mechan ism has been responsible for fatalities in
survivable aircraft accidents. ~ince some light
ai rcraft seats a re not equipped with shoulder
harnesses, the pilot should try to min imize this
hazard by avoiding a nose- first impact against solid
obstacles; he should also make it a habit to insist on
the routine use of seat belts in his aeroplane.
Speed and stopping distance
The overall severity of a deceleration process is
governed by speed (groundspeed) and stopping
distance. The most critical of these is speed ;
doubling the groundspeed means quadrupling the
total destructive energy, and vice versa. Even a
small change in groundspeed at touchdown - be it
as a result of wind or p ilot technique - will affect
the outcome or a controlled crash. For example : an
impact at 70 knots is about twice as h azardous as
one at 50 knots. This is the main reason that pilots
who are flyi ng at treetop level in marginal weather
are ad vised to slow to a comfortable airspeed when
forward visibility is less than the minimum required
for obstacle avoidance. It is also obvious th at the
actual touchdown durin g an emergency la nding
should be mad e at the lowest possible controllable
airspeed , using a ll available aerodynamic d evices
(flaps, etc.),
Most pilots will instinctively - and correctly look for the largest available flat and open field for
a n emergency landing. Actually, ver y little stopping
Aviation Safety Digest 107 I 21
�distance is required if the speed can be dissipated
uniformly, th a t is, if the d eceleration forces can be
spread evenly over the available distance. T his concep t
is designed into the arresting gear of aircraft carriers
tha t provides a nearly constant stopping force fro m
th e mome nt of h ook-up.
Since the typical general aviation aircraft is
d esigned to p rovide p rotection in crash la ndings
tha t ex pose the occupants to nine times the
accele ra tion o f gravity (nine g) in a forward
di rection , it is interesting to compare the minimum
required stopping distances a t various speed s,
assuming that the crash deceleration takes place a t a
uniform nine g. At 45 knots the required dista nce is
three me tres while at 90 knots it is J 2 metres (four
times as long). Although these figures arc based on
a n ideal d ecelera tion process, it is comforting to
know what can be accomplish ed in a n effectively
used short sto pping distance. U nderstanding th e
need fo r a firm but uniform d eceleratio n p rocess in
very poor te rrain en ables a pilot to select
touchdown conditions th at will spread the breaku p
o f dispe nsable structure over a short distance,
thereby reducing the peak d eceleration or th e
cockpit/ca bin a rea.
Attitude and sink ra te contr ol
T h e most critical - and often the most inexcusable
- error that can be made in the planning and
executio n of an eme rgency landing, even in ideal
te rrain , is the loss of initia ti ve over the aircraft's
attitude a nd sink rate a t tou chdown . Whe n the
touchdow n is made on fla t, ope n terrain , an
excessive nose-low pitch atti tude brings the risk o f
'stickin g' the nose in the gro und . (Extreme
exam p les of th e d estructiveness o f such a n
occurre nce a re staJl/spin accide n ts). Steep ban k
a ngles j ust before touchdown sho uld also be
avoided; they increase the stalling speed a nd the
li kelih ood o f a wingtip strike.
Since the aircraft's vertical com ponent of velocity
will immediately be reduced to zero upon ground
con tact, it sh ould be ke pt well under control. A flat
LOuchdown at a high sink rate (well in excess o f
500 fee t pe r minute) on a h ard surface can be
injurio us without d estroying the cockpi t/cabin
strucLUrc, es pecially during gear-up landin gs in
low-wing aeroplanes. A rigid bottom constru ction of
these aeroplanes may preclude ad equate cushio ning
by structural d eformation. This characteristic, in
combination with the r athe r limited huma n
tolerance to vertical g , has led to spinal injuries in
extremely hard 'pancake' landings. On the other
ha nd , similar impact condi tio ns may cause
structural colla pse of the overhead strucLU re in
high-wing aircraft. On soft terrain an excessive sink
rate may cause digging-in of the lower nose
structu re a nd a severe forwa rd d eceleratio n.
Simula ted forced landings, occasionally, lead to
acLUal forced la ndings at a high sink ra te wh en the
engine fails to respond as anticipated. T he ha bit o f
a utoma tically raising the nose whe n the th rottle is
advanced for a go-around, without waiting fo r
engin e acceleration, can lead to d estructive sink
rates. It is ad visable to maintain the proper
a pproach speed a nd atti tude until e ngine response
is assu red; this aJso applies to go-aro unds fro m
baul ked la nd ings.
22 I Aviation Safety Digest 107
Techniques
T he 'school solutio n' to an emergency tha t calls for
a fo rced landing requi res the following seque nce of
immediate actions:
-Maintain aircraft control (establish a glide at the
proper speed ).
-Select a field a nd plan a n ap proach .
These actions may be combined with attempts to
correct th e e me rgency, es pecially whe n the pilot
surmises the n ature of the proble m (carbure ttor
heal, mixture, fuel selector , etc.). However, attempts
lo troubleshoot th e cause o f the e mer gency should
be m ad e only on a time-availa ble basis. U nde r
certain conditions the pilot may have a full-time j ob
j ust controlling the aircraft. W h en losing one e ngine
of a light twin d uring th e critical take-off phase , a
p ilot m ay n ot have more than a split second to
d ecide wh at is best: relyi ng on the pe r fo rma nce
cha rts, or his impulse to redu ce power on the good
e ngine to m aintain controllability.
Concerning the con troversial subject of turning
back to the run way followin g an engine failure on
take-off, each pilot sh ould de term ine the minimum
altitude at which he would attem p t such a
ma noeu vre in his particular aircrafo.
Expe rimentation at a safe altitude should give the
pilot an approximation of height lost in a
d escending J 80 d egree turn at idle power. By
adding a safety factor of a bout 25 per cent h e
should arrive a t a practical 'decision height'. It
speaks fo r itself th at the a bility to ma ke a ' 180' does
not n ecessarily' mean that the departu re r unway can
be reached in a power-off glide; this d epends on
the wind , the distance travelled during the climb,
the h eigh t reached a nd the g lide d istance without
power .
Terrain selection
A pilot's ch oice of emergency la nding sites is
governed by:
-The route h e selects during th e p re-fli gh t
planning.
- His heig ht above the grou nd whe n the emergency
occurs.
- His airspeed (excess airspeed can be converted
into dista nce a nd/or altitude).
The o nl y time tha t he has a ve ry limited choice is
du ring the low-and-slow po rtio n of the ta ke-off; he
sh ould realise, however , that even und er those
conditions th e ability to ch a nge th e im pact heading
only a few d egrees may e nsure a survivable crash.
Whe n he is beyond glid in g distance of a suitable
open a rea, the pilot sh oul d judge the available
ter rain for its e ne rgy-absorbing capability, as
explained earlier. If the eme rgency starts at a
considerable heigh t above th e ground he sh ould be
more concerned about first selecting the desired
general area than a specific spot. Terrain
a ppearances from altitu de can be very misleading
a nd considerable altitude may be lost before the
best spot can be pinpointed . For this reaso n, the
pilot should not h esitate Lo discard his original plan
for one tha t is obviously better. H owever , as a
general rule, he should not ch a nge his mind more
tha n o nce; a well-executed crash la nd ing in bad
terrain can be less hazardous than a n uncontrolled
touch down on an establish ed field.
Aircraft configuration
Since fla ps im prove manoeuvrabili ty at slow speed ,
a nd lower the stalling speed, their use d uring final
a pp roach is recommended wh e n time a nd
circumsta n ces pe rmit it. H owever, the associa ted
increase in d rag a nd d ecrease in gliding dista nce
call fo r caution in the timing a nd the extent of their
a ppli~ation ; prema ture use of flap , a nd dissipation
of altitude, may jeopardise an o therwise sound pla n.
A hard-a nd-fast rule concerning the d esired
position o f a re tractable landing gear at touchdown
cannot be given . In rugged terrain a nd trees, or
during impacts at a high sink rate, an extended
gear would d efinitely have a protective effect on the
cockpit/cabin area. H owever, this ad vantage has to
be weighed against the possible side effects of a
colla psing gear , su ch as a ruptured fuel ta nk.
Manufacturer 's instructions - if given - sh ould be
followed .
Wh.en a ~ormal . touc~down is assured, a nd ample
stoppmg dista nce 1s available, a 'gear up' lan d ing on
level, but soft terrain, o r across a plou ghed field ,
may result in less aircraft d amage than a 'gear
d own ' la nding.
De-activation of the aircraft's electrical syste m
before touchdown reduces the likelihood of a
post-crash fire. However, the batter y maste r switch
sh ould no t be turned off until the pilo t no longer
has a n y n eed for electrical power to o perate vital
systems (fla ps, hydraulics, e tc.). Positive aircraft
control during the final pa rt of the a pproach has
P.rio rity ove r all other considerations, including
aircraft configuration and cockpit checks. T h e pilot
should try to exploit the power availa ble from an
irregula rly running engine; however, to avoid
unpleasant surprises during the tou chdown phase it
mig h t be best to switch the engine a nd the fuel o ff
just before touchdown. This not onJy ensures the
pilot's initiative over the situation but a cooled -d own
engine reduces the fire hazard considerably.
Approach
When the pilot h as time to m anoeu vre, the
planning of the a pproach sh ould be governed by
three factors:
- Wind direction a nd velocity.
- Dimensions and slope of the chosen field .
- Obstacles in the final a pproach pa th.
These three factors a re seldom compa tible. Whe n
compromises have to be made the pilot sh ould aim
for a wind/obstacle/terrain combina tion th at pe rmits
a final a pproach with some margin for error in
judgm e nt o r technique. A pilot who over-estimates
his gliding range m ay be tempted to stretch the
glide across obstacles in the approach path (trees,
powerlines, etc.). For this reason it is sometimes
bette r to plan the a pproach over a n unobstructed
a rea, rega rdless of wind directio n. Experience
shows that a collision with obstacles at the end of a
ground roll , or slide , is much less h azardous tha n
striking an obstacle a t flying speed before the
touchdown point is reached.
No specific rules can be give n for th e pattern to
be flown; th er e may not even be time to set up a
pa tte rn. T he most importa nt consider a tion is to get
into such a position with regard to the selected spot
that it can be reach ed by using normaJ techniques
such as playing the final turn (turning in early or
la te, d epending o n altitude), slipping, a nd moderate
S-tu rns. If conside rable altitude h as to be lost while
over or near the ch osen field , it should be done so tha t
the field remains within glid ing d istance; speed
control during all ma noeu vres is vital.
Touchdown
The importance of having control over the aircraft's
a ttitude a nd sink rate a t touch down has already
been explained. Since a n e mergency la nding on
suitable terrain resembles a situa tion with which the
pilot should be familiar th rou gh his training, only
the more unusu al situations will be discussed.
Type of terrain
Confined areas
The natural prefer ence to set th e aircraft down on
the ground should not lead to th e selection of an
open spot between trees or obstacles whe re the
ground cannot be reached without ma king an
'auto-rotative' d escen t; this option sh ould be left to
pilots o f rotary-wing, STOL a nd VTOL aircraft.
Once the intended touchdown point is reached ,
and the remaining open and unobstructed space is
ver y limited , it may be better to fo rce th e aircraft
d own on the ground than to delay touchdown until
it stalls (settles) . An aircraft d ecele ra tes faster after
it is on the ground than while airborne. Thought
may also be given to the d esira bility of
ground-looping or re tracting the la nding gear in
certain conditions.
A river or creek can be an inviting alternative in
oth e rwise rugged te rrain . T he pilot should e nsure
that h e can reach the wa ter or creek-bed level
without snagging his wings. T he sam e concept
applies to road-landings with one additional r eason
fo r cau tion; ma n-made obstacles o n either side of a
road may not be visible until Eh e finaJ por tion of th e
a pproach. Road traffic must be given priority.
When planning the approach across a road , it
sh ould be r e membered tha t most high ways, a nd
even ruraJ dirt roads, are paralleled by power or
tele phone lines. Only a sharp loo kout for the
supp? r tin g structures, or poles, may provide timely
warnm g.
Trees (Forest)
Although a tree landing is not a n attractive
prospect, the following gene ral guidelines will help
to ma ke the experience survivable:
- Use th e normal la nding configura tion (full fla ps,
gear down).
- Keep the grou n dspeed low by h eading into wind .
- Make contact at minimum indicated airspeed, but
not below staJl speed a nd ' ha ng' the aircraft in the
tree branches in a nose-high la nd ing a ttitude.
Involving the underside of the fuselage and both
wings in the initial tree con tact provides a m ore
even and positive cushioning effect, while
preventing pe ne tration of th e windshield.
- A void direct contact of fuselage with heavy tree trunks.
- Low, closely spaced trees with wide, d e nse crowns
(bra nches) close to the ground are m uch better
than tall trees with thin to ps; the latter allow too
much free-fall heig ht. (A free-fall fro m 75 feet
results in .an impact speed o f a bout 40 knots, or
4000 feet per minute).
- Ideally, initial tree con tact sho uld be symmetrical,
tha t is, both wings should meet equal resistan ce in
Aviation Safety Digest 107 I 23
�the tree branches. This distribution of the load
helps to mainta in proper a ircraft attitude; it may
also preclude· th e loss of one wing, which
invariably leads to a more rapid and less
predicLable descent to the ground.
- Always aim for the softest and, whe n possible, the
lowest part of a tree or tree line. judge trees by
their abili ty to slow the aircra ft's for ward speed in
the same manner as a firefighter's safet y net
catches fa llin g people.
- If heavy tree trunk contact is unavoidable once
the a ircraft is on the grou nd, it is best to involve
both wings simultaneously by directing the
aircraft between two properly spaced trees. Do
not attempt this ' manoeuvre' while still airborne , as
recommended in some textbooks.
Mountainous terrain
The variety and irregularity of mountainous terrain
makes it impossible to list general rules. T he pilot
s hould learn to instinctively avoid situations where
an emergency would leave him without any choice;
flying needlessly low a nd slow over rugged terrain
is an example of such a situation.
In mountainous country, only a short glide may
be sufficient to bring the a ircraft over lower-lying
terrain , thereby increasing effective altitude and
terrain choice ; maintaining a comfortable cruise
speed will assure the pilot of this advantage.
Slope la ndings should be made upslope whenever
possible, with due consideration for the terrai n
conditions at the end of the slope. Avoid a situation
where an excessive roll, or slide , would bring the
aircraft to a sharp drop-off. When landing on a
pronounced upslope, enough speed should be
maintained to change the aircraft's descendin g
flightpath, just before touchdown, into a climbing
o ne that approx imately parallels the slope. (Note: A
descent at 50 knots and 500 feet per minute results
in a six degree flightpath. In combination with an
approach to a 24 degree upslope, an uncorrected
six degree flightpath would lead to a ground
'impact' angle of six degrees + 24 degrees =
30 degrees).
Water (Ditching)
A well-executed water landing probably involves less
deceleration viole nce than a poor tree landing or a
touchdown on extremely rough te rrain. The reason
for the apparent reluctance of some pilots 'to take
to the water' when the re are no suitable alternatives
may be the certainty of losing the a ircraft or the
fear of getting trapped. Actuall y, a fixed-wing
aircraft that is dit~ hed at minimum speed and in a
normal landing attitude will not sink like a rock
upon touc hdown. Intact wings a nd fuel ta nks
(especia ll y when empty) provide flotation for at
least several minutes even if the cockpit may be just
below the wate rline in a high-wing aircraft.
When conside ring the feasibility of ditching, the
following factors should be taken into account:
-The water te mperature and the estimated time to
be spent in the water. (The s urvival time in water
with a temperature of zero de grees Celsius is less
than one hour for the average person).
- The physica l condition of the occupants a nd their
a bility to swim .
- T he proximity to land .
24 I Aviation Safety Digest 107
- T he availability of lifejackets and other
water-survival equipme nt.
- The number of occupants and the number of
usable exits.
Loss of depth percep tion may occur wh en
land ing on a wide expa nse of smooth wate r, with
the risk of fl ying into the water or stalling-in from
excessive altitude. T o avoid this hazard, the aircraft
should be 'dragged in' when possible. Use no more
tha n in termediate naps on low-wing aircraft; the
water res istance of full y extended flaps may result
in asymmetrical flap fa ilure and sle wing of the
aircraft. Keep a retractable gear up. Insist that all
occupants kee p their restraint systems fastened until
th e aircraft has come to a complete stop ; this
ensures impact protection and preve nts
disorientation with respect to the nearest exit
location, regardless of a ircraft attitude and light
conditions. Ditching d ow nstream in a swift running
river has th e same effect as a headwind, it reduces
the relative grou ndspeed.
l
In brief from Papua New Guinea
Snow
A landing in snow should be executed like a
ditching, in the same configuration and with the
same regard for loss o f d e pth perception (white
out) in reduced visibility and on wide open terrain.
An even snow la yer, several feet thick , ma y blanket
smaller obstructions and make otherwise rough
terrain more suitable; pronounced 'humps' that ma y
hide larger obstructions should be avoided.
Survival and rescue
T h e scope of this stud y precludes a discussion of
the actions to be ta ke n to ensure survival a nd rescue
following an e merge ncy landing; in addition ,
considerable li terature is available on this subject
from various sources. For this r eason, only some
ge neral guidelines are repeated:
- T he filing of a flight p lan not onl y e nsures
prompt response from search organisations but it
directs the search towa rds the most li kely area.
-Search efforts are aimed at locating the a ircraft;
make it as conspicuous as possible a nd stay near
it, unless you have compelling reasons to abandon
it. Keep in mind that s moke is an interna tional
atte ntion gette r.
- I f the aircraft is d estroyed, or inaccessible, you
will have to work with whatever you h appe n to
carry in your pockets; when flying over remote
and unfriendly terrain, kee p the minimum
essentials on your person, such as wa terproof
matches and a pocketknife.
- Basic life support supplies should be carried in
the a ircraft as protection against extre me
temperatures; when a ppropriate, warm clothing
in the winter, a nd water when making a summer
dese rt crossing.
Conclusion
A pilot who knows his aircraft and understands
the what and why of the techniques that will
ensure a survivable emergency landing under
adverse conditions has no reason for morbid
preoccupation with the possibility of being
forced down. The peace of mind associated with
this knowledge should improve the pilot's
overall performance which, in turn, may prevent
an emergency or benefit its outcome •
The Pilat us Porter was operated by a charte r firm
based in Pa pua ew Guinea. O n the clay of the
acciden t it had been flo wn 011 a series of short
lligh ts tra nspo rting freight in to va rio us aerodromes.
The piloL, wh o was ve1·y experie nced both on type
a nd in to tal ho urs, had flown fo r th ree a nd a
qu arte r ho urs on the cl ay whe n he departed fo r the
18 minu te fligh t to his next deslination.
Th e d estination ae rodrome was a 604 metre long,
grass and clay strip , 3900 feet AMS L in the Papua
ew Guinea Highlands. W ith a longitudinal slope
of nearly seve n pe r ce nt, the stri p is snitable for
o ne-way operatio ns on ly.
Al t hough the weather in the area was fi ne when
the a ircraft arri ved on this fl ight, the p ilot cou ld see
that rain had fa lle n since his previous la nding there
earlie r in the clay. He a lso noted that he wo uld have
a ta ilwind com ponent of aboul 10 knots for landing.
Fo llowi ng a no rma l circui t, the aircra ft crossed
the thres hold at 60 knots and touched down 180
metres in fro m it. After ro lling for about 150
me tres the p ilot noticed a clog ru n n ing across Lhe
strip in fro nt of the a ircraft. H e auempted to steer
the aircra ft towards the left side or the strip and
a p p lied reverse thrust and brnkes.
Almost im mediately directio nal con trol was los t
on the sli ppery clay sur face. The airc1·aft veere d off
the strip and came to rest with the starboard wheel
lodged in a deep ditch. T here were no injuries
sustain ed by the clog or the pilot but the ai rcraft did
suffer su bstantial damage.
During the investigation the pilot stated that
the re we re no mechan ical pr oblems with the a ircraft
nor an y personal facto1·s wh ich contributed to the
accident. He believed the loss of directional control
was d ue to the combination or the left q ua r tering
tailwind, which tended Lo weathe rcock the aircraft
to th e left, a11d the slippery su rface which affected
steeri ng and braking effectiveness.
From a h u lll a11 factors viewpoin t, it is d ifficult on
this occasion, eveu with the be nefir of hindsig ht, to
say that the pilot's reaction was wrong. I t could
have easily been a person that crossed the str ip
instead of a n animal. The collision with a dog
wo uld probabl y have resul ted in significantly less
damage to the aircraft; however, natural instinct is
lo avoid an obvious collisio n even though the results
of a lte r native action are u ncertain.
The social train ing to p reserve life, in an y fo r m,
cou ld also have been a relevan t su bconsciou s factor.
If you had been this pilot, confronte d with the
s ituatio n , what would you have done? •
Aviation Safety Digest 107 I 25
�Birds, birds and more birds ..
•
~
Birds continue to be a hazard to both stationary and airborne aircraft with varying degrees of
damage and risk resulting.
The Aviation Safety Digest has printed two articles
recently about. the problem or birdstrikes. The
response from our reade rs has made it clea r that
the problem is o f concern to the great majo rity of
practising pilots. Whi le there is no single sure-fire
solution , a commo n sen se approach can certainly
reduce the frequency of birdstrikcs. T he following
le tte rs rro m two o r our read ers illustra te this fact.
The first le tte r is from a pilot living a t Mount Isa ,
Queensland , whe re large numbers of black kites are
to be found.
'Regardin g yo ur rece nt articles about birdstrikes,
I remember reading years ago when RPT a ircraft
began using the ir landing lights d uring daylight
ta ke-o ffs a nd la ndings, it was said tha t the lights
helped birds (a nd people, a nd p resuma bly other
animals) to see a nd a void the aircra ft. At the time a
fe w of the loca l commercial pilo ts also tried this
procedure, but now it seems to have been almost
forgotten in ge nera l aviation . While cruising I have
seen a cairn fl ock of birds scatter wildly whe n I
flicked on the lights.
'During m y ea d y training I had to do numerous
take-offs and landings amongst gro ups o f black
kites. I was to ld that the best wa y to avoid hitting
the m was ro continue o n a stead y !light pa th and
allow the birds lo take eva sive action. If you tr y to
dodge the bi rds they do not know which way you
a re going a nd so cannot get out of yo ur way.
'I know there arc times wh e n a collision is
inevitable bu t I reel these two me thods are fairly
e ffecti ve a nd wo uld like to see more people tr ying
them. In 10 years an d ove r 3000 ho urs fl ying I
have hi t o nl y two hawks, both o n ta ke-o ff and be low
200 feet.'
The second letter is from a pilot who ope rates
from bush strips in the north-west of NSW .
'During last su m mer , I wa s o pe rating a Cessna
172 fro m a well-maintained strip on a private
pro perty. Arou nd noon one d ay, as I was pre paring
fo r lunch , I noticed a Cessna 182 joining the circu it
for a n approach o n to the 050 degree strip. Und er
the approach pa th .t here is a fair ly large lake where
trees and dense fo liage abound . As was usually the
case during summe r , the lake was playing host to
some thing like 300-500 birds.of variou s types.
'It wa s a cool , tra nq u il atmos phere for the birds
until this idiot in the 182 lite rally roa red the gu ts
out of the e ngi ne as the aircraft passed low almost too low - over Lhe trees in a nd around the
lake. The sta rtled birds rose qu ickl y in a cloud tha t
totall y e ngulfed the 182 . H ow the ai rcraft didn't
prang I'll never know because it was "blood and
g uts" fro m one e nd to the other - the pilot m ust
have been alm ost lFR a t the point of touch d ow n
and, a lthoug h the e ns uin g motio n of the aircraft
26 I Aviation Safety Digest 107
closely resembled a j azz walLz, t he aircraft was
undamaged when it stopped at the othe r e nd o f the
strip and backtracked to j oin me.
' At the first sight or this fl ying abattoir I
pro mptly lost m y ap pe tite and condescended to
he lp the pilot clean up the mess. I late r d iscove red
tha t th is pilot was a relati ve newcome r to fl ying and
this was only his second trip to the bush. And, after
a ll tha t, he had o nly dropped in to ask d irections a s
he had become unsure of his position. I worked out
that he was 55 kilom etres off track.
' Ignoring his limited navigational ability, the point
I wish to emphasise is tha t I had been using the
same su-ip m yself a ll morning without raising as
much as a mu rm ur fro m the birds. l' have see n
similar occurre nces ti me and time again, although
no ne as serious as o n this occasion.
' Is n't it time t hat a pilot's training became
prac tical? Theoretical fl ying will kill someo ne in
such a sittta tion. And the a nswer is so simple. I was
alte rnating m y own proced ures to fit in with the
situa tion - someti mes l would use a tig hter base
point to kee p well away fro m the trees and at other
times I wou ld make a high , non-powered a p proach
if I chose to pass over the trees con tain ing the
bi rds.
'P lease Mr Editor, let us tr y and stop this
unnece ssar y d amage to a ircr aft aud r isk Lo h uman
life. Pilots should be aware of the d anger and learn
to recognise t his siwatio n . A little more tho ught in
pla nning their circuit may save a lot of
em bar rassme nt later.'
Although the problem of bird str ikes to a irborne
aircraf't usua ll y resu lts in the greatest obvio us
damage and r isk, there is still co nsiderable da nger
l"ro m birds a nd other creatures making nests inside
statio nar y aircraft. Two read ers recently told us of
their p roblem relating to birds nesting in the ir
a ircra ft while p arked at Archer fie ld air port in
Q ueeuslaud.
' My Moone y M20 a ircraft has had liulc use
rece ntl y as I have bee n overseas a nd it has been
ke pt tied clown in the parkin g area at Arche rfi e ld .
Du ri ng a pre-flig ht inspectio n , a fter my re turn, I
noticed bird d rop pings a nd pieces o f straw aro und
the tail a rea . I d ecided to have a closer look and
with the aid of a torch I exam ined t he inside of the
lowe r tail assem bly. Much to m y su rprise I
discovered two birds nests co nta ining fo u r eggs.
The nests we re ve ry clam p and apa rt from the risk
o f fou ling the controls I believe there wo ul d be a
great risk of corrosion. T he airc ra ft in our pa rking
area ofte n have birds sitti ng o n the fin and ru d d er
so o ne com p lace ntly accepts the siwatio n of the
birds using t he a ircraft as perches.'
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Aviation Safety Digest 107 I 27
�The seco nd lette r continues:
' Recently, after taking off from Archerfield on a
local flight, all o pe rations a ppeared normal unlil l
e ndeavoured to turn the aircra ft a t 500 feet. The
a ilerons o pe rated no rmally e nterin g the turn but
j a m med whe n l tried to stra igh ten o ut.
' I was able to maintain level fligh t by using a
combinalio n of power, rud d er and elevator. I mad e
immediate prep ara lions to la nd a nd, as l made m y
base turn, the operation o f' the ailero ns returned to
norma l.
'After a safe land ing I ins pected the a ilerons and
fo und a small piece o f' metal j a mmed between the
a ile ron a nd the wing tip. On further investigation
insid e Lhe wing Li p I discovered a birds nest, which
was impossible to sec wilhout the aid of' a torch. As
J walked away from the aircraft several swallows
flew into s paces in both wings.
'Before the incide nt, my pre-take-off checks had
ind icated that all operations were normal. It was
o nl y whe n the aircra ft wa s ba nked that Lhe rubbish
fro m the nests became jam med in the ailerons. A
short time late r l re moved the wing tips a nd fo und
fo ur large nests. The birds had used eleven meLa l
tops from rin g-pull cans a nd a small piece of metal,
which I had noticed the previous week, lying near a
local repair shed .
'I have now bird-proofed my a ircra ft with the use
of removable wire pa tches. The wing tips and
ailerons have been modified so that obj ects will n ot
be j a mmed in the trailing edges.
'Some time ago after ta king off I noticed the
airs peed ind icator was not wor king. A beetle had
c raw led into the pitot tu be. A month ago I had to
poison thousands o f ants which were eating Lhe
foam rubber seats. On the same d ay while I
endeavo ured to inflate the tyres I stood on a live
hare lying in short grass underneath the aircra ft. l t
" bo lted " on to the run way. All I need now are bats
in the belfry and I will give up fl ying.'
Readers are re minded of the hazards to
sta tionar y aircraft wherever they are pa r ked a nd
are advised to ensure that birds a nd other creatures
are not nesting inside the m •
From a pilot in England
The following article is a contribution from a United Kingdom reader of the Aviation Safety Digest.
Although his story concerns an incident in England, the lessons he learned from it are applicable to
aviators throughout the world.
'Some years ago I was asked by fr iends lo fly a n
Apache 235 to allow them lo photogr aph th eir
far m. The fligh t was to be fro m a small grass
aerodrome in the west of Engla nd. The aerod ro me
is surrou nded by gra ni te wa lls wilh two moorland
hills, 350 fee l AMSL, o nl y three kilometres away to
Lhe east.
'Being close to the A tlanlic coast, the local
wea ther can cha nge ver y ra pid ly wil h the onset of
fog a n d high winds. On the da y o f the flight the
summer weather was cool and d r y with a fi ve knot
wind fro m the north . T he fo recast obta ined at
I OOO hou rs ind icated VMC thro ughou t Lhe d ay wilh
eig ht oktas of stra tus cloud at 8000 fee t.
The a ircraft contained abou t half ils maximum fuel
load and , wi th th ree passe ngers plus the pilot on
board , was well below max imum ta ke-off weigh t and
within c. of g. limits.
'At 11 00 h o urs a norma l take-o ff was comple Led
towards the north and the a ircraft was accelerated
to 74 kno ts lake-off sa fety speed . After selecting Lhe
gear up a nd reducing to climb power, I was
ac.ijusti ng th e pi tc h to synchronise Lhe pro pelle rs.
The gear selection le ver had just reLU rned to
ne u tral with an audible 'click' whe n I abru ptly
fo und LhaL the aircrnf't was in thick cloud.
' My first reactio n was to su ppose that I h ad
mis-set the a ltimeter whic h now read 370 feet a bove
the ae rod rome level. T he passenge r in the
r ight-ha nd fro nt seal assured me, however, that it
was correctly set a nd that we had encou ntered
coastal fog. The fog was identical in colour and
appearance to the strntus cloud 7600 feet above it;
no ne of the a ircraft occu pants had observed a ny
sig n of the fog before takin g off.
28 I Aviation Safety Digest 107
'I was very ala rmed as I did n ot hold a curre nt
instrum e nt rating even tho ugh I had held a ser vice
raling in 1953. From pr evious ex pe r ience of the
local weather I concluded that the fog ban k, which
was clearl y being ge nerated from a headland on the
coast fo ur or five kilometres to the no rth, was
moving wit h the wind a nd would shortl y o bliterate
the who le aerodrome. l the refore made a cau tious
180 degree left turn o n instruments, away from the
hills a nd once esLablish ed on a southerly head ing
asked everybody to look for the ru nway, which duly
r~-appea red a short time late r be neath the left
wmg.
' H aving re -establish ed visual contact my main
Lho ught was Lhat l did not want to be messing
arou nd in th is muck at this d ead h eight in a hot
aeroplane that I h ad only flow n fo r six hours. I also
recalled that the a ircra fL was required at midday fo r
a nother Lrip. To save time, I d ecided to make the
sout herly overfl y into a d ownwind leg and I carried
o u t the pre-land ing checks. Accordingly, wit h the
gea r a nd half fl ap exte nded , I began a left tu rn at
400 feel th rough 180 d egrees on to final a pproach.
'The aircra ft had tu rned through abo ut
90 degrees whe n a curious vibratio n began, like a
gentle "nibbling" at the airframe. My passenger in
the rig ht-hand front seat, himself a pilot who h ad
recently nown in this Apache, warned me that l
s ho uld nol let the a irspeed get below 70 knots. I
looked down at the ASI a nd saw to my horror it
was a few knots below 70 . Instantl y I checked that
the pitch was full fin e, opened u p the throttles to
full power , ra ised the gear a nd straighte ned the
a ircraft. Because we were pointing at one of the
moorla nd hills, a bout 400 metres a way, I turned
right to sort out m yself, the aircraft a nd the
situatio n . A fe w minute s later the a ircra ft was
pro pe rl y alig ned with the run way o n fi nal ap proac h
a nd in the correct configuration. A normal land ing
was made. The sea fog neve r did reach the
aerod rome but stayed to wind ward all day.
' I h ave though t a bout this e pisode ver y deeply
because, despite my training, m y years at study ing
aircr aft behaviour a nd years of reading wa rning
comments by experts, whe n a diffic ult situation
develo ped I ver y nearly spu n a load of passengers
into the grou nd. T he " nibbling" I had felt was
undo ubtedly pre -stall buffet, althoug h I did not
recognise it as such and, had it not been fo r the
forgi ving, thick Piper wing, the aircraft would
probably have stalled a nd autorota ted . The re would
h ave been little cha nce o f recovery fro m tha l
height. Incidenta ll y, I did not hear the stall wa rning
syste m o pera te so these d evices are not infallible.
' I t seems to me there a re two inslructive points
abo ut the incide nt and the fact that a fa tal accident
did not result does not d etract from the ir
importa nce. T he firsl importa nt point is t he amoun t
o f unsuspected drag that landing gear and flaps can
p roduce, with a n immediate d egrad ation of
a irs peed ; pilots are not normally aware of this drag
increment because the aircra ft is at a suitable h eig ht
a nd there fore h as the e ner gy to restor e Lhe
a irs peed. The second a nd much more impor ta nt
point in the lo ng term is the shattering effect that
an unexpected situation can have upon pilot
judgment a nd perform a nce. Despite yea rs o f
ex perie nce and thou ght I still allowed that fog to
screw up m y o pera ting skills!'
About the author
M r Hugh Scanla n was the ediLOr of Shell Aviation
News for 14 year s u ntil production ceased at the
e nd of 1978. H e is an ex-RAF fighte r pilot and has
been in curre nt flying practice for 28 years. As a
stud e nt of ae rod yn a mics, his pa rtic ular inte rest is
ligh t aircrafL ha ndling a nd con trol. As e ditor of
Shell Aviation News he studied numerous p ape rs o n
that particula r subject•
Aviation Safety Digest 107 I 29
�MD and the taildragger
The following story is based on an accident report from the not-too-distant past. It is a classic
example of Murphy's Law and the consequences to which it may lead. Our Man in the Dustcoat (MD)
acts out the circumstances.
The old taildragger had sat in the back of Murphy's
hangar for a long, long time. Its C of A and
registration had expired but every once in a while,
when things were slack, Murphy would gel the
mechanics to do a bit more work on it.
I t was basically sound but in need of a major
overhaul and after a number of years was just
beginning to look like it might fly again. As time
progressed MD began to take a special interest in
the old girl a nd one day expressed this interest to
Murphy.
'Murph y, how much will she cost when the major
is finished?' asked MD.
'Don't know MD. Wh y, you wa nt to buy it?'
'We ll ... ' MD pondered, 'maybe if the price was
right.'
'Look MD, we're pretty busy at the moment and
I'll need you blokes to work some overtime,' replied
Murphy. 'How about you cut out your overtime
against the cost. That way you'll save on tax a nd I
won't have to fork out the cash.'
'I'll let you know, boss.' It was only a few days
later when MD agreed to Murphy's terms about the
purchase of the aircraft.
Over the next few months, which seemed like
eternity to MD, he put in many hours overtime for
Murphy and every other spare minute working on
the taildragger. There were lots of interruptions
and MD often had to down tools to look after a
customer's problems. Eventually the stage was
reached where the major was finished and Murphy
completed the necessary paperwork to get the
aircraft re-registered.
Murphy took the aircraft for a test flight on a
calm , clear morning. The windsock hung limply on
the pole a nd MD watched enviously as his pride
a nd joy was put through its paces. He was joined by
a local instructor pilot who had flown the old girl
quite a lot before she had been decommissioned.
'She looks good MD,' he remarked as Murphy
settled the aeroplane on the strip. 'Mind if I take
her for a fly, for old times sake?'
'No fear ... I'll come with yo u ,' MD responded
joyfully, a nxious to get into the air. They were soon
airborne and during the flight MD arranged with
the instructor to get his tailwheel check-out.
A few days later, and a few circuits later, the
instructor told MD he was okay to solo in the
ai rcrafl. MD had been checked on the use of power
and brakes to maintain directional control on the
ground but he still had a little trouble in crosswinds.
'Get some more practice MD and you'll soon get
the hang of it,' the instructor had told him. 'The
tailwheel steering will loosen up with a bit of use,'
he added.
MD flew a few circuits whenever he could fit
them in and slowly gained more confidence,
30 I Aviation Safety Digest 107
although occasionally he did feel that all was not
well. After a few more hours' practice MD decided
he was read y to take his wife and children for a fl y.
One Friday afternoon at the end of a busy week's
work, he flew the aircraft from Murphy's strip to
the main airport near the town a nd left it in the
parking area.
The following morning MD's fam ily were
excitedly looking forward to their first flight in
their own plane. There was only a light wind
blowing as MD carried out his daily inspection. He
noticed that the rudder was over to one side and
realised that he had not fitted the control locks on
the previous day. As he was checking the rudder
stops for any damage he noticed something strange
about the tailwheel and after some further checking
concluded that the tailwhee l and rudder seemed to
work back-to-front to each other.
'Better check with Murphy,' thought MD and he
wandered off to the telephone.
After listening to MD describe the problem
Murphy replied, 'I think I know what's wrong but
I'm too busy to come up there and have a look.
Wh y don't you fly down here. The wind's not too
bad and you shouldn't have any trouble getting in .'
Back at the aircraft MD explai ned what was
happening to his wife. 'Not much wind so there
shouldn't be any problem taking you and the kids.'
They all boarded the aircraft and, after a short
flight, were overhead Murphy's strip. The light
wind was now about eight knots and straight across
the strip. MD set up his approach for a three point
landing but on touchdown the aircraft began to
swing into the wind. Despite MD's efforts to stop it,
the swing continued so he put o n the power for a
go-around. The main wheels had just left the
ground off the side of the strip whe n the tail struck
one of the 'half 44' strip markers. MD closed the
throttle and put the aircraft back on the ground
with a lot of drift. One main gear leg collapsed and
the aircraft slid to a stop on its crumpled wi ng and
broken landing gear.
MD and his family left the aircraft, shaken but
unhurt and walked over to the hangar where
Murphy was standing, scratching his head and
wondering why the heck MD had his fam ily with
him.
The moral of the story? Well, apart from anothe r
example of Murphy's law at work (the tailwheel
steering bellcranks had been installed back-to-front)
the most important factor is that MD chose to fl y
the aircraft with a known defect; and on top of that
he risked the safety of his family by taking them
along as well. Inconve nie nce and delay is a small
price to pay to ensure the safety of an aircraft and
its occupants •
s~~fue ....
letfe1t ~ ~ 11t~.
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�Vision 1 -
the blind spot
In aviation today, in spite of sophisticated air traffic control and navigation systems, the ~ee-and•be-seen
concept is still a most important element in collision avoidance. To '!lake the mos~ of this conc:ept, ~e
should know our sight limitations. This is the first of a series of articles concerning the phys1olog1cal,
psychological and environmental factors that affect visual efficiency.
+
'
One little known limitation of the human eyeball is the p henomenon common to everyone, is to learn how to
blind spot where ligh Lstrikes the optic nerve. In most use your eyes in an efficient scan and overcome vision
eyeballs this b lind .spot is about 30 degrees right of
blockages caused b y the aircraft structure.
centre, looking straight ahead. With both eyes open How to scan
a nd vision unobstructed by objects, the blind spots of The best way to start is by getting rid of bad habi ts.
each eye are cancelled by the peripheral vision of the Naturally, not looking out at all is the poorest scan
opposite eye. T he brain combines the image and the technique, but glancing out at intervals of five minutes
blind spot disa p pears.
or so is also poor when you remember tha t it takes only
But what happens when peripheral vision from the seconds for a disaster to happen.
opposite eye is obstructed by an object such as a
Glancing out and giving it the old once-around
windshield centrepost? Now the brain cannot fill in the without stopping to focus on an ything is practically
image. How large is the void? I t's about a
useless; so is staring out into one spot for long periods
one-and-a-h alf degree cone diverging from the optic of time.
nerve. Under some conditions it could block
So m uch for the bad habits. Learn how to scan
instrume nts from view and will blank out a 707 two properly by kno wing where to concentrate your
kilometres away. A 74 7 will disappear three kilometres search.
away.
In normal flight, you can generally avoid the threat
You can fin d your blind spot on the pictu re above. of an in-night collision by sca nning an area 60 degrees
Hold the picture at a rms length· with both eyes open, Lo the left and to the right of your central vision area.
focusing o n the cross on the left windshield. Then
This doesn't mean you should fo rget the rest of the
bring the picture in until it is almost touching your
area you can see from your side windows e very few
face. With both eyes open you should not lose sight of scans. H orizontally, the statistics say, you will be sa fe if
the 74 7 in the right wind shield. Now close your left e ye you scan 10 degrees up and down from your flight
and try it again. Keep your right eye focused on the vector. This will allow you to spot an y aircraft tha t is at
cross as you bring the picture in towards your face .
an altitude that might prove hazardous to your own
The 7 4 7 will disappear, then reappear as you d raw the flight path, whether it's level with yo u , below and
p icture closer.
climbing, or above and d escending.
When yo ur blind spot limitation is combined with
In the circuit area especially, clear yourself before
empty field myopia (the tendency of the e ye to focus at every turn, a nd always wa tch for traffic making an
about six metres wh en there is nothing to focus on), improper e ntry into the circuit. On descent and
you can really appreciate you r visual limitations even climb-out, make gentle S-turns to see if a nyone is in
u nder CA VOK conditions.
your way. Make clearing turns, too, before attempting
The solution to this problem, a natural
any manoeuvres •
Aviation Safety Digest 106 I 3
�Fuel consumption and the
mixture control
- -- - - - -+ Fuel
Exhaust gas
temperature gauge
..----+---411• Throttle
During the preparalion of two articles for A viation
Safety Digest 103 ('Take notice of emply fue l gauges'
and 'The last gasp') fifty reports qf recent accide nts
and incidents which involved loss of power as a result
of fu el exha ustion were analysed.
Three factors involving Lhe pilot showed up time
a nd again - inadequate knowledge of the aircra fl's
fuel system, failure to physically check the ta nk
contents be fore departure and an over-optimistic idea
of fuel consumplion rates at the engine settings being
used .
In man y cases the inadequate knowledge of the fu el
syste m took Lhe form of confusion between Imperial
a nd U. S. gallons in such areas as tank capacity, u sable
fue l, ga uge calibration and fuel consumption graphs
a nd La bles .
The ne xt in the Lrio of pilot factors - no physical
check of Lhe tank contents before flight - needs little
comment. T he gauge readings, the previous pilo t's
estimate, o r e ve n the most sophisticated calcula tion
based on previous flight times is no substitute for
loo kin g in the ta nks. This piece o f wisdom is proven
ove r and over again - unfortunately, too oflen the
hard wa y - a nd the number of experie nced and
conscie ntious pilots who have fallen for the trap
suggests that no one is immune.
T he use o f o ver-optimistic fuel consumptio n rates in
fli ght planning a ppare ntly results fro m a fa ilure to
apprecia te that rates shown in the Owne r's Ma nual or
Pilo t's O perating H andbook are valid only if the
mixture is leaned in accordance with recomme nded
procedures. Furthermore, there is also a lac k of
appreciation of the magnitude of the fue l pe nalty
resultin g from incomplete lea ning or omitting to lean
Lhe mixture during cruise. An old friend, the
misconception that the mixture should not be le aned
durin g cruise below 5000 feet, also showed up several
times .
Engine ope ration with the mixture full y rich or only
pa rtially leaned during cruise is unli kely to cau se an y
serious harm although there have been cases of a n
unusu a l form of exhaust valve erosion leadin g to
failure, which have been attributed to the e ffects o f a n
over-rich mixture. H owever, operation with an
unnecessarily rich mix ture is at best untid y and the
fue l consumption penalty may be ver y high indeed.
In man y cases a pilot's reluctance to lean out to
maximum powe r seems to be caused by concern for
the engine and this in turn is the result of the
misconception that, when leaned in this way, the
mixture is weaker than normal. As the following article
from the FAA GeneralAviation News points out, leaning
to maximum power is mere ly correcting a n over-rich
mixtur~ which results from the reduced air d en sity at
altitude. T he a r ticle is highly recommended as a clear
ex planation o f the principles involved . Befo re going
4 I Aviation Safety Digest 106
on, however, try this qui z for the aircraft you fly. Refer
to the aircraft Flight Manual, Owne 1·'s Manual, or
Pilot's Operating Handbook to ve rify your answers.
- What is the capacity of the fuel tanks?
- Is this in Imperial or U .S. gallons?
- What is the usable fuel ?
- Are the fuel gauges calibra ted in Impe rial or U.S.
ga llons?
- What are the conversion factors -litres to Imperial
gallons, litres to U.S. gallons, U.S. gallons to
Imperial gallons?
- What is the maximum ga uge e rror as shown by the
fuel gauge calibration card and where does this
occur?
- What does each division on the ga uges represent?
One quarter tank, one fifth, some other quantity?
- What cruise fuel consumption ra te would you
expect at 3000 feet:
leaned for maximum power?
leaned for maximum ran ge?
with the mixture control in full rich ?
As an interestin g, instructive and highly valua ble
exercise if you h ave not alread y done so , at the next
suitable opportunity carry ou t an accurate check of the
actual overall fuel consumptio n achieved using you r
normal power settings a nd leaning tec hnique. You
may be surprised .
Acknowledgement is give n to t he U.S. Fed eral
A viation Agency for the following article adapted
from the General Aviation News.
The engine doctor and the case of the vanishing fuel
Pilot: Doctor, I've been referred to· you for some
advice about the aircraft I fly. I'm not getting an ything
like the range I should and the fuel consumption
varies so much I don't know what to plan on. I ma ke
regular inte rstate trips and for the three hours flight I
might use from 20 to 30 gallo ns of fuel. I hope it
doesn't mean the engine is packing up- it's only done
800 hours.
Doctor: Let me get a little histor y. Has the fuel
consumption always been erratic or has it just started ?
Pilot: It's a lways been a little unpredictable but it
seems worse over the last few months since I moved
east and be gan making these regula r inte rstate trips.
It's only about 1100 km round trip and the book says I
should ge t about 1400 km on a full ta nk at 75 per cent
powe r , but Doc, if I don 't re fu el, l get home with the
ta nks almost dry.
Doctor: Hmmm. Sounds like a check-up is in order.
Might not be se rious, but. then again ... How does it
run?
Pilot: It runs smoo th - excep t whe n I fly over the
mounta ins, and everybod y knows aeroplanes always
go into 'automatic roug h' over wate r and mounta ins,
so that's probably my imagination. As for a check-up,
that was the first thing I though t of, so I had the
Air
1600°F
Exhaust
Combustion
Movement of gases
through a piston engine
hundred hourl y done early, just to be sure. lt all
checked out okay. Plugs had a little lead on them but
they cleaned up good. The LAME said th ere was
no thing wrong that could affect the rue! co nsumption
- nothing wrong at all. I even wonde red if I was
getting bad fu el - too low octane or some thing - so l
asked aro u nd, but nobod y e lse admitted to having the
same proble ms. It wor ries m e because I do n't fee l
com fo rtable in a sick aeropla ne. Can you suggest an y
specia l tes ts?
Doctor: Ma ybe later - but first I wa n t to examine
yo ur method of ope ration, if yo u don't mind .
Pilot: Oh, come on, Doc. I've got several hundred
hours a nd ne ver had a p ro blem before . As k the
training school where I learned to fl y - I soloed in six
ho urs. Ne ver be nt an ything, never had a n accident no t e ve n an incident. And I h ad no trouble
tra nsitionin g to this ai1·craft, e ve n ifl do say so myself.
Doctor: I'm not questioning your fl ying ability.just
wonde rin g about your procedures. For exam pie, wh at
power settings d o you u se e n route? And wha t about
yo ur altitude profile?
Pilot: I always cruise at about 70 per ce nt p ower,
e ve n thou gh they say it's okay at 75 per cen t - I like to
be nice to my en gine. I use 23 and 23 (2300 rpm, 23
inches of ma nifold pressure) most o f the time. And the
a ltitudes - they don't vary much eithe r . I u su ally kee p
below 5000 until the Divide and the n get up to abo u t
6000 if the weathe r is clear. Once in a while , if it's earl y
e no ugh in the d ay so the air is smooth , I'll go up a nd
over the mo untains, that takes about 8000 feet. That's
funn y tool Instead of takin g less gas to Oy highe r, I
ge nerall y use more .
Doctor: I see. Now tell me, how do you ma ke these
altitude cha nges - by 'stair ste pping' at fixed points?
Pilot: Well , no , just a gradua l stead y climb if I'm
outside the CT A.
Doctor: Aha! And what about the mixture - d o yo u
ma ke frequent adjustme nts?
Pilot: Not when I' m climbing, of course. I always
lean when I get up to my maximum a ltitude. Of
course , I always run l'ull rich in a climb, or cruising
below 5000, like you' re supposed to.
Doc tor: What ma kes yo u think yo u're not supposed
to lean during cruise be low 5000 feet?
Pilot: My instructor ta ught me that years ago, whe n
first learne d to fl y.
Doctor: I a m afra id that is a very much
misunderstood instruction. 'Neve r Jean below fi ve' is
good advice when re ferrin g to ta ke-off or climb power ,
certainly. But nowadays, at least, the engine
ma nufacturers are te lling yo u that with a normally
as pirated e ngine at cruise power - which can be
a n ywhe re from 55 Lo 75 pe r cent o f' full power -you
should adju st the mi xture for an y signif'icant cha nge in
altitude or power setting. ·rh is saves fu el and keep s the
engine running cleaner.
Pilot: At any altitude? Even at 2000 o r 3000 fee t ?
Doctor: I've done it at I OOO feet and got improved
performa nce. Wh y not?
Pilot: I heard you could get d etonation .. .
Doctor: Not if you follow the ma nufacturer's
instructio ns. Know you r power settings - tha t's the
key - they are all in the Pilot's O pe rating Handbook .
Be sure the rpm are where they be lo ng - and the
ma nifold pressure, with a co nsta nt speed propeller
like yours. In a ny case, if yo u climb steadil y for most of
the trip, without leaning en rou te, yo u can e xpect to
waste a ton of fue l. You might be able to save about te n
per cent out of a full ta nk by going to 8000 feet e arly,
leaning the mixture prope rly, a nd cruising at that
altitude .
Pilot: You d o n't say?
Doctor: I d o. Incidently, whe n yo ur o ld instructor
cautioned y.o u a bout neve r lea nin g below 'five' was he
talkin g about de nsity a ltitude or MSL?
Pilot: I d on't re me mber. MSL I think. Does it m a ke
an y difference?
Aviation Safety Digest 106 I 5
�Doctor: Considerable. For example, you might be
fl ying o uL o f an aerodrome at nearl y 3000 feet this
summe r wh e n the temperatures are around 35°C.
That cou ld give you a density a ltitude of over 6000
feet, which means that your engine is very like ly Lo be
runnin g a little rough or giving you less than normal
powe r if yo ur mixture is at full rich on take-off, and
while you are climbing.
Pilot: I never heard of taking off or climbing a t less
than full rich.
Doctor: You are hearing it now. Lyco min g, who
makes you r engine, recommends that before taking
off from any airport where the altitude is above 5000
feet densiLy a ltitude, you lean at maximum rpm to the
point where the engine runs smoothes t - or by
reference to the fuel flow meter if yo u have one.
Naturally th is does not apply Lo turbo-charged or
supe rcharged engines, which always a re on full rich al
take-off.
Pilot: Naturall y.
Doctor: Now suppose you describe for me yo ur
leanin g procedure.
Pilot: Standard procedure, Doc. Ease the mixlure
control knob back until the engine gets a little rough ,
the n push it in until it gets smooth. T e ll yo u the truth, I
get ed gy whe n the engine even acts like it is going to
run ro u gh, so I usuall y stop leaning just short of that
point.
Doctor: Oho! I suspect we have uncovered another
root of your problem. With your tried and true
method o f leaning you a re probably in the habit of
feeding yo ur little bird an overly rich diet, which leads
to a n inefficient performance and perhaps some other
complications which have not ye t su rfaced.
Pilot: I still think it's the fuel. I ne ve r had a ny
trouble before l came east.
Doctor: Perhaps. But I think yo ur proble ms simply
became more prominent here because we have higher
a nd more var ying terrain, which calls for more
frequen t a nd accura te mixture 'adjustment. Swppi ng
short o f a distinct engine response makes it impossible
to lean acc urately, especially without cylinde r
tempe rature or EGT gauges. Wha t yo u experienced as
'automa tic rough' over the mountains was probably
the result of an overly r ich mixture. No telling how
much unburnt fue l you are blowing out of yo ur
exh aust. Do yo u know what the diffe rence is in fuel
consumption, at cru ise, betwee n full rich a nd optimum
leaning?
Pilot: A few miles per gallon, I guess.
Doctor: l've heard re po rts varying from 15 to 25 per
cent. Lycoming, for example, says that their highe r
horsepower e n ginc;s use about three and a half gallo ns
more per ho ur without leaning. They say that in a
typical installation that will cost you one hour of flig h t
time from a full tank.
Pilot: That much? That is considerable. But I still
hate the idea of leaning till I get a rough e ngi ne o r a
bunch of d etonation.
Doctor: l think you are unduly worried because the
wo rd 'lea ning' has several different meanings. Let's
back off a little and consider the basic situation . You
know that yo ur en gine burns air and fu el in a
proportion of approximately 15 to 1, by weig ht. Whe n
we ach ieve the optimum mixture we get what is known
as a che micall y correct combustio n - or a clean burn.
Virtually a ll of the oxygen and fuel are consumed, a n d
6 I Aviation Safety Digest 106
all of the available energy is released. For any given
engine this ideal proportion is the same al any altitude.
However, with increases in altitude the density of the
a ir is reduced, and the proportion of fuel is e nriched.
That produces an overly rich (o r c he mically incorrect)
mixture and eventua lly a loss of power. We can
compensate in one of' two ways; by supe rcharging or
turbocharging the engine-which compresses the air,
so that the proper mixture is automaticall y maintained
for us - or by what is popularly known as 'leaning'.
N ow, leaning in this sense simply means pulling back
on the mixture knob to reduce the ra te of fu el flow to
the carburettor or the cylinders. You 'lean' d u ring
cruise to achieve the chemicall y correct combustion no more. For your type of e n gi ne there is no point in
ac hieving a 'lean mixture', that is to say, a
less-than-ideal proportion of fuel. This could lead to
some engine problems under certain circumstances.
Pilot: That's what both ers me about leaning to
roughness, before smoothing it out.
Doctor: l don't think you can go wrong by following
yo ur Pilot's Operating Handbook, and that is exa~tly
wh at it tells you to do. You see, with small engines, and
with practically all carburettor-equipped engines, fuel
distribution is never exactly even. One cylinder will
usually reach its lean mixture limit before the others
and start misfiring, which produces roughness. But
th is is not the same as d etonation , and normally the
engine will not stop. Even if it should , from
overzealous leaning, pushing in slightly on the mixture
control should restart it immed iately.
Pilot: Wh y don't we want to have a chemically
correct mixture on take-off or climb, then? Or do we?
Doctor: No, we do not. Because the chemically
correct combustion achieves peak tem perature for a
give n power setti ng - about 2200°C at maximum
cruise power. At full power the te mpe ratures wou ld be
far higher, abo ut 3300°C, and this wo uld damage the
e ngine, so at hi gher-tha n-cru ise power settings we
always keep the mixtu re on the rich side of the ideal
proportion - full rich, for take-off be low ' fi ve'. It also
happens that you get maximum power slightly on the
rich, or cooler, side of yo ur chem icall y correct mixture.
You can observe this on our chart.
Pilot: Do you mean, the leane r the mixture the
hotter the burn?
Doctor: That is true, up to a point. Re member too,
the unburnt fuel in a rich mixture serves to help cool
the engine.
Pilot: Then why bother LO lean the e ngine at take-off
on higher altitudes?
Doctor: Because if' you exceed the rich tolerance
limit yo u lose power, which you ma y need for a safe
take-off. Yo u may also get misfiri ng and possibly
fo ulin g of the plugs. You should know what rpm to
expect, and be alert if you see them fa lling off. Ease the
mixture out until they come back to normal, and then
ease it in slightly.
Pilot: It see ms to me that there ought to be a more
scientific way of doing it. Aren't there a n y gauges that
will help?
Doctor: The re arc temperature ga uges, and they do
help , within certain limits. We'll get into that next time
yo u come in. Meanwhile, l suggest you go out in yo ur
aeroplane and put a few or the ideas we discussed into
practice. See if you r fuel consum p tion does n't go
down. Nex t please •
Low cloud, blind valley
• • •
S_afe operation of an aircraft under Instrument Flight Rules involves more than just the manipulatron of the
aircraft controls. It requires adequate pre-flight planning and preparation. When the non-instrument rated
pilot ~fa Piper Comanche entered cloud on a Special VFR flight, the aircraft struck a mountain and the pilot
was killed. Fortunately, his two passengers had left the aircraft when it landed earlier and had travelled to
their destination by car.
The pilot was a middle-aged businessma n who had
been flying for 16 years and had accumulated over
3000 hours experience, of which more than 1600
hours had been flown in Comanche type aircraft. He
held a private licence but becau se or colour bli ndness,
he was not authorised to fly at night. Several yea rs
earlier, the pilot had successfully completed a flight
test for a Class 4 (Day) instrument ratin g but before his
lice nce could be suitably endorsed , the De partment
withdrew this class of rating. AL the time o f the
accid ent, the pilot did not hold an instru me nt rating of
any kind.
. A.s part-owner of the aircraft, the pilot had equipped
1t wllh a n ADF, a VOR and a DME, and had a
transponder on order. A two-axis auto-pilot with
' headin g hold ' capability was also installed, and the
a ircraft was approved for Night VMC operations.
On the morning of the accident, the pilot submitted
a VFR fl ig ht p la n a t Archerfield for a fli g ht with two
passengers to Bundaberg and return, at a nominated
cruising a ltitude of 8500 feet for the nonhbo und leg.
Other aircraft in the area on lFR flig hts reported
conside rable periods in cloud while aircraft
maintaining VFR h ad to fl y at lower levels. Most were
corn pelled to dive rt from track a nd a t least two aircraft
were forced to turn back before reaching their
destination. Towards Bundaberg, however,
conditions improved and it was fine whe n the
Comanche arrived.
By early afternoon , the pilot and his passengers had
corn pleted the ir business and they boarded the aircraft
for the re turn fli ght. After takin g off from
Bu nd abe rg at about 1400 hours, the a ircraft
climbed to the planned cruising a ltitude of 7500
f'e~ t but, sh.ortly afterwards, the pilot was ad vised by
Flig ht Service that both Archerfield and Brisbane
control zo nes we re closed to VFR operatio ns.
By now, the weather over the whole area had
? ete rio rated . Around Brisbane, conditio ns we re being
influe nced by a n unstable south-easterly strea m, whic h
was causing rapid fluctuations·in the weather with
heavy showers a nd low cloud. Reaching Gy m pie, the
pilot requested a Special VFR clearance through the
Brisbane co ntrol zon e Lo Archerfie ld at either 7500
feet or 1500 feet but the clearance was not granted and
the pilo t was told that the condi tions a t Archerfield
were at the minima.
At that stage, the pilot decided to land a t
Maroochydore a nd await developme nts. He made no
e ffort to find a break in the cloud cover for the descent
but began a let-down in IMC, over-flying the Nambour
VOR and then tracking to Maroochydore. T he aircra ft
did not become visu al until it was down to a bo ut 1500
feet over the sea a nd , after orbiting to await the
passage of a rain shower, the a ircraft landed at abo ut
1500 ho urs.
Once on the ground, the pilot telephoned the
Archerfield briefing office a nd asked about the
current weather situation at Brisbane and Archerfield.
He was told that both comrol zones had been closed to
VFR operations for most or the afternoon and that no
prospects were held for a ny substa ntial improvement
in the weather. H e also discu ssed tra nsitting through
the Amberley control zone, a ppare ntl y with the
intention of making a roundabout entry to Archer field
from the west via Kilco y. After some discussio n, the
pilot then said he wou ld fl y to Redcliffe on the
northern boundary of the Brisba ne zon e a nd further
review the situation from there.
At 1626 hours, the a ircraft took off from
Maroochydore and whi le e n route to Re dcliffe, and
before and after landing, the pilot again requested a
Special VFR clearance to Archerfield , either via the
lan e of entry or through the Brisba ne control zo ne, or
alternatively a clearance with Brisba ne Airport as the
d estina tio n. Because of low cloud , restricted visibility
and associated IFR traffic, no ne of these cleara nces
were granted but it was agreed that the req uests would
be kept under rev iew. As it happe ned , while the
aircraft was on the ground at Redcliffe, a te mporary
im provemenl in the wea ther would have allowed ATC
to consider Specia l VFR operations in the Brisbane
control zon e but attempts by Brisbane Fligh t Service to
contact the ai rcraft were not successful.
At this stage, the passengers decided to corn plete the
rest of their j o urne y by car but the pilot elected to stay
wi th the aircraft, mention ing that the re was still some
d aylight left and tha t the weather might improve. H e
te lephoned a frie nd with a private airstrip to the
south-west o f Redcliffe and, after checking on the
ser viceability of the strip, arranged to fl y there and , if
n ecessar y, sta y the night. On d epa 1·ture from
Redcliffe, the pilot again contacte d Bri sbane Flight
Service and requested a Specia l VFR clearance to
Archerfield through the la ne of e ntry, but by n ow the
weather had deteriorated again and the clearance
cou ld not be granted.
After landing at the private airstrip the p ilot
prepared to stay overni g ht, but then mentioned to his
friend that he had to fly the next day and he was
concerned that the stri p, which had a natural surface,
may become unserviceable if the rain con tinued
during the night. Before securing the aircraft for the
night, the pilot said he wo u ld ma ke one last call to
Archerfield and, a t 18 14 hours, he again telephoned
the Archerfie ld briefing office. Once more he asked
about the lates t situation a nd requ ested a Specia l VFR
clearance to enter the zo ne throug h the lane of entry.
At that stage, the cloud base at Archer field was 1000
fee t, the r a in had eased a nd visibility towards the lane
in the direction from which the aircraft would come
was about 13 kilometres. It was stressed that, if the
Aviation Safety Digest 106 I 7
�Pilot's view of the northern entrance to the Archerfield
lane of entry. The correct track is shown on the left; the
probable flight path of the Comanche is on the right.
pilot lost no time in departing and if conditions
rema ined the same, a Special VFR clearance for flight
in the zone would be gra nted . Last light at Archerfield
was 1843 hours and the pilot estimated the flight
would take 13 minutes.
Afte r telling his friend he might be back if the
weather did not look suitable, the pilot returned to the
aircraft. About 10 minutes later, it took off into the
north but, instead of turn ing so uth-west towards the
northe rn end of the lane of entry, it headed initially in
a westerly direction , possibl y to avoid a nearby rain
shower. The pilot tra ns mitted a departure time of
1822 hours, with an estimated time of arrival at
Archerfield of 1835 hours. H e was advised that he
wou ld be given a Special VFR clearance eight
kilometres from the control zone boundary and his
acknowledgement of this information was the last
communication received from the aircraft.
Sho rtly afterwards, several witnesses in a valley
about nine kilome tres west of the lane of entry saw the
Comanche fl ying in drizzle at a very low height
benea th cloud. This valley heads in a south-westerly
directio n whereas the track through the lane of e ntry is
to the south-east. Some distance along the narrowing
valley, the aircraft began to climb and it di sappeared
into cloud.
When nothing more was heard from the aircraft, a
Distress Phase was declared but it was not until four
days later that the wreckage was finall y discove red
about 400 feet below the summit on the north face of
8 I Aviation Safety Digest 106
Mt D' Aguilar, which rises steeply to 2550 feet. The
aircraft had crashed in extreme ly r ugged, inaccessible
terrai n , and the accide nt site was directly in line wi th
the track of the aircraft when it was last see n from the
ground.
It was readil y apparent from the evidence of witnesses
that the pilot, though not rated , occasionally operated
the aircraft in instrument meteorological conditions.
Passengers who had Oown with t he pilot earlier on the
d ay of the accident reported that the aircraft h ad been
ope rate d in cloud and the p ilot obviously conside red
himself competent in the use of all the radio navigation
aids installed in the Comanche.
Although it was doubtful that the aircraft had been
flown in cloud on the first leg of the flight northbou nd
from Archerfield , there was no doubt at all abo ut the
retu rn fligh t during the afternoon. The witnesses in
the aircraft confirmed that the p ilo t descended in
cloud at Marooch ydore, using the Nambou r a ids.
From 7500 feet down to a he ight of 1500 feet, the
a ircraft was in cloud and rain. At no time apparen tly,
did the pilot contemplate returning to Maryboro ugh
or Bundaberg in VMC, or turning back until VMC was
established and then proceeding visually be neath
cloud to Maroochydore.
A further indication of the pi lot's attitude to fl ying in
cloud was his contemplation ofa flight over Kilcoy and
Amberley. With ra in showers over the coast and hills,
and with Brisbane and Archerfield both closed to
VFR, it is inconceivable that any pilot could consider a
VFR flight over that route as a n alternative to fligh t
a lo ng the coast. Th is fligh t did not e ventuate of course
but even to have contemplated it is indicative of t h is
pilot's attitude that he was qualified but because of a
technicality, unable to hold an instrument rating, and
could therefore fl y in IMC - albeit illegally - at any
time. This seems to have given him an assurance of his
capabilities far beyond that of the usual VFR pilot.
It ap peared from his radio communications that the
pilot continually painted a more optimistic picture of
the weather conditions than other airspace users and
obser vers o n the grou nd . Even his telephone
con versations suggested h e was biased in his
obser vations, and at one stage he was cautioned on his
assessment of the weather.
At the time the aircraft took off from the p ri vate
airstrip, a witness described the conditions as clear in
the immediate vicinity of the strip with a general cloud
base of eight oktas above 1500- 2000 feet, five to six
oktas at various levels down to 300- 500 feet and
traces of cloud between 150 and 200 feet along a
nearby river. To the sou th, in the direction of
Archerfield , and to the east the visibility was at least
eight kilumetres but to the north and west it was
less than 1300 metres, and it was not possible to tell
wh er e the rain merged into the cloud base.
Although last light at Archerfield was 23 minutes
after the aircraft took off, witnesses near the airstrip
said the light faded quickly about 10 minutes after the
Comanche departed. Quite apart from the other
weather considerations, the pilot's decision to
commence the flight in rapidly approaching d arkness
seems another indication or his attitude of being able
to change to instrument flight at an y time.
From the fl ight path of the aircraft subsequently
established by ground witnesses, it seems certain that
the pilot decided to fl y around the shower near the
entrance to the Jane of e n try and then turn south-cast
down the lane through the gap between the rain and
the D' Aguilar range. For this reason he initially flew
westward and the n turned south-west in a sweep which
the pilot probably thought would bring the aircraft
into the lane.
It would a p pear that for some reason, the pilot flew
too far west and turned up the wrong valley. Altho ugh
the exact reason for his failure to turn is not defini tely
known, it is likely that in the prevailing conditions and
at low level, he wo uld have had difficulty in identifying
visual reference points, particularly if diversions
around showers were also required. The lane of entry
and its northern approaches are difficult areas for
map-reading, especially at low level. The countryside
consists of undulating ground with a series of small
valleys and timbe red ridges lyin g across the lane.
There is no clearly defined valley, road, ri ve r or
railway line leading down the la ne towards
Archerfield. I t has been estimated that the additional
distance betwee n the entrance to the lane and the point
where the aircraft eventually turned up the valle y
Aviation Safety Digest 106 I 9
�would have been covered in about 45 seconds flying
time.
Once the aircraft had entered the valley, it seems the
pilot became·aware of rising terrain on either side and
put the aircraft into a climb. The pilot had once told
one of the witnesses that if he was ever caught out by
bad weather, he would climb out of it rather than try to
regain visual contact beneath cloud. As the aircraft had
struck the ridge directly in line with its last observed
track, it is likely the pilot adopted this course of action.
But the gorge at the end of the valley is very steep and
it would seem that, once committed, the aircraft would
have been unable to outclimb the D'Aguilar Mountain
Range.
In a great many accidents that occur as the result of
attempted visual flight in adverse weather conditions,
the events leading up to the crash itself take place over
a considerable time interval. Often the aircraft strikes
some navigational difficulty or diverts around
supposedly 'local' conditions for quite some time
before it is finally trapped by the weather. This
accident is unusual however, in that it happened only
eight minutes after take-off on a flight with an
expected duration of 13 minutes. The decision to
attempt the flight was made in this case while the
aircraft was safely on the ground, the weather which
was to be encountered was clearly visible from the
ground and the pilot knew the terrain to be crossed.
He was aware of the failing light and that conditions
had been fluctuating rapidly througtioul! the
afternoon.
Though the pilot had persisted in his efforts to reach
Arche rfield during the whole of the a fternoon he did
not mention any pre ssing need to complete the flight
that evening. Certainly, he had been concerned about
the possibility of rain affecting the serviceability of his
frie nd's airstrip, but at that stage he had the option of
fl ying back to Redcliffe, only four minutes away, and
leaving the aircraft there for the night. Earlier, when
the aircraft was on the ground at Redcliffe, the pilot
seemed quite resigned to the situation and the
possibility that he might have to spend the night at his
friend's place. He gave the impression that he might as
well stay with the aircraft and see how the weather
developed, without being concerned too much either
way. Nevertheless, he did not leave the aircraft a t
Redcliffe and, when fl ying to the private airstrip, he
continued to seek special clearances to reach
Archerfield.
The pilot was aware that conditions suitable for
'Special VFR' existed in the lane of entry eight km
from the boundary of the Archerfield control zone
and obviously intended to stay visual below cloud and
make a quick low-level flight to that point. Before
taking off, the pilot had remarked to his friend that, if
conditions were not suitable , he would be back. But a
return to the private strip would only have been
possible for a few minutes after departure because of
the fading light, and though the pilot probably
intended to remain below cloud, his 'way out' if he
encountered any problems would not have been a
return in VMC, but a climb in IMC.
The pilot did not seem in an y way overawed by the
task ahead of him but seems to have been supremely
confident that, once the ' formality' of obtaining the
Special VFR clearance eight km from the Archerfie ld
control zone boundary had been met, his arrival was
assured. Although he said he might re turn, it was not
very likely he thought he would be back. It seems the
pilot's confidence in his ability to fl y on instruments
was such that he belie ved he could extricate himself
from any difficult situ ation if it b ecame necessary.
On this occasion, by the time the pilot realised he was
in difficulty, the aircra ft was already in a position from
which it could not outclimb the rising te rrain in the
distance available •
Frost
It is not hard to imagine what a layer offrost like that in the photograph could do to the aerodynamics of an
aircraft. Our picture was taken at Roma in Queensland on a clear July morning and shows the amount of
frost that can form on the external surfaces of an aircraft in certain weather conditions - even in the
'Sunshine State'.
But the frost need not be as thick as this to create a
serious hazard, as the pilot of a Cessna Agwagon
discovered rece ntly' when he attempted an
earl y morning take-off fr~m an agricultural strip in
south-eastern Queensland , with a thin layer of frost
on the wings.
The pilot had commenced operations from the strip
the previous afternoon a nd, whe n he had finished for
the day, he refuelled the aircr a ft and left it parked in
the open. The next morning was cold and cloudless,
and there was no wind. Returning to the strip at about
0600 hours, the pilot carried out a daily inspection a nd
found the ai rcraft covered by a thin layer of frost. H e
was aware of the hazards of a tte mpting to ope ra te
a ircraft with frost on the wings, but he con sidered on
this occasion it was not thick e nough to cause a
10 I Aviation Safety Digest 106
problem. He started the engine and let it warm up
while the loader driver prepare d to load the aircraft.
While the engine was running, the pilot notice d the
slipstream from the propeller had blown all moisture
off the windscreen. He carried out his pre-take-off
checks and, with the aircraft loaded to about 66 kg
below the maximum permissible take-off weight, h e
lined-up for take-off. Opening the throttle wide, he
checked the engine was delivering full power a nd, as
the aircraft accelerated along the strip, the ta il lifted
normally.
At 65 knots, he ~ried to lift off but there was only a
slight shuddering and the aircraft would no t become
airborne. He continued the ta ke -off and , at a highe r
speed, the aircr aft eventually le ft the gro und bu t
immedia tely struck a fe nce at the e nd of the strip. T he
pilot quickly closed the throttle and the a ircraft la nded
heavil y in a wheat cro p in the next field. T h e left
landing gear broke off, the left wing tip d u g in and the
aircraft somersaulted on to its back a nd cam e to rest
inverted some 240 metres fro m the e nd of the strip.
The pilot was not injured.
The pilot was very experienced in agr icultural
opera tions a nd had a total of about 12 500 flying
hours. He had encountered frost on his aircraf t before
and his practice was to e ither hose it o ff or , if a hose was
not available, to fl y the empty aircraft o nce arou nd the
circuit.
On this occasion , the pilot saw that the frost on the
wings was about three millimetres thick and h e did not
consider r emoving it because he believed a layer as thin
as that would not be sufficient to cause an y significan t
degrad ation in the aircraft's h a ndling characteristics.
The pilot was unaware, howeve r, that it is not so m uch
the thickness of the laye r th at creates the problem as its
irregular surface. This roughness increases drag a nd
causes early airflow se paratio n over the win gs. A
higher airspeed is required to ge nerate sufficient lift
for ta ke-off, a nd conseque ntly a lon ger take -off
distance is necessar y. Had the pilot been mindful of
these effects, he might have 1·ecognised the red uced
performa nce sooner and eithe r d u m ped the hopper
load in order to clear the fe nce or abandon ed the
ta ke-off and brought the aircraft to a stop - even if it
involved a deliberate ground loop a t low speed - with
far less disastrou s r esu lts.
The acciden t to the Agwagon provides a timely
reminder of the hazards in neglecting even a thin
coating of frost on an aircraft and shows th at the
p roble m is n ot confined to cooler climates but can
occur in normally warmer areas given the r igh t
conditions.
r
Yet anoth e r aspect of the frost hazard was brought
to our notice recently by the captain of a D C-9 which
was being p re-flighted at Canberra fo r a sche d uled
early mor n ing de parture fo r Syd ney. While carrying
out his external inspection, the captain noticed a reas of
frost extend ing ove r about five squ are metres on the
top sur face of each wing. Decidin g to have a closer
look, he stood o n a baggage bar row a nd discovered
large areas of ice up to about three millimetres thick
wh ich were not visible from the gro und. One of the
cabin overwing em ergency exits was then removed
a nd a furthe r check revealed what at first sight
appeared to be water from melted frost on th_e inner
section of the wing but o n closer inspection tur ned out
to be clear ice.
T he ca ptain said the o utside air tem per a ture at the
time was zero degrees.Celsius and there was some
sunlight on the win gs. It seemed to him the frost had
me lted in the weak su n and then run dow n the wing
surface, wh ich was still very cold, and re-frozen . The
aircraft was delayed for 80 minutes wh ile the up per
surfaces of the wings a nd stabilizer were de-iced with
alcohol.
D uring his p re-flight inspection, the captain
recognised the frost patches as a poten tial hazard , and
h is persistence in follow ing up the initia l indications no
doubt a~erted wha t may well h ave developed into a
serious occurrence •
Aviation Safety Digest 106 I 11
�.
Wings, wizards and wisdom
An old-head aviator tells how superior skill and cunning can be overcome by bad planning and bad
judgment.
I stood in the grass near the run way watching the
spot landing contest. The lig htpla ne pilots wer e
aiming fo r a line painted across the runway just
beyond the numbers, and several h ad come fairl y
close. A red a nd white Cessna was now on downwind
for his sho t at winning the prize. The pilo t pulled
the throttle to idle and I watch ed his patte rn towards
the target. When he turn ed from base to final, he was
o bviously too high. H e slowed the aero pla ne by pulling
the nose up and the descent a ngle steep ened. It wa s
still a ppar e nt th at he was going to over shoo t so he
pulled the nose up even hig he r , violating everything
sacr ed to safe ty. His genius for converting lift into a
plummeting desce nt was outstanding. It a p peared that
he might at least come close to the tar ge t. H e was lo w
enoug h that I could see the set of his j aw a nd l
imagined cross ha irs on his glazed eyeballs as the plane
dro pped r apidly towards the mark.
The la ndin g gea r tried to cu shio n the crunch, but
it s praddl ed with a n indecent shedding of
alum inium garme nts into a sh am e ful heap. I r an to
o ffer assista nce, but found two healthy p eople,
althoug h the dazed pilot seem ed a bit cr estfalle n. His
disa ppointme nt, was centred o n missing t!1e target,
instead of the fact that he h ad just be n t his aeropla ne.
This incide nt is a n example of poor judg m ent the kind o f situatio n caused by a pilo t not p ro per ly
orde ring his prio rities. Whe n peo ple are unable to
place things into pro per pers pective they can becom e
a hazar d to the m selves o r other s. T h ey m ay be
hi g hl y skilled, even extremely smar t, but something
ha ppe ns to them that short-circuits their ability to
see thin gs as they r eally are. In a similar way, pilots
ar e some times struck with m o m e nts of insanity that
tempor aril y paralyse their jud gm e nt. You m ay be a
wiza rd at the art of fl ying but if you can't put t hin gs in
their proper per spective, you'r e pr o ba bly heading for
an accide nt.
We all acknowled ge that safety h as prio rity ove r
most things. Wh y then, do low-pr iority ite ms so
o fte n lead to a n accid en t? The d esire to ge t a
contr act sig ned o ver at Fogville, a compulsio n to get
ho m e in s pi te of a strange-sounding engine an d bad
weath er , o r the te mptatio n to show the boss you can
d escend lower tha n m in imums and get him to that
im portant m eeting a re low-prio rity reasons for
fl ying. A conscie nti9 us pilo t will no t permit dem ands
of such mino r importa nce to co mpromise his basic
desire to fly safely.
T here is a te nde ncy to equate the abili ty to m ake
good d ecisio ns with som e u nre lated qualities such as
I Q . I know som e very sm art people who were
involved in fly ing stupid ly, so it is n't me ntal voltage
that dete rmines the use of j u d g m ent.
Whether we are wizards o r just o rdinary folks
tho ugh, o u r ability to make good decisio n s sho uld
improve with experie nce. As a youn g and
inexperienced avia tor, I im p ulsively blundered into
more th a n o ne h air -ra ising adventure. Now, as I
view the sa me situa tio ns through bifocals under
. thin n ing grey ha ir , l h ave insig hts that p rovide
12
I Aviation Safety Digest 106
barrie rs against foolish ness. I'm sur e that frequent
d oses of substantial frig h t had much to do with
chan ging my attitude towards fl yin g. The most
important chan ge was my develo pm ent of a m ore
tho u ghtful a ttitud e.
The cool head wh o does everything righ t when the
serpents of disaster ar e coiled fo r a stri ke h as
probably conditio ned h is decisive power s th ro ugh a
thoug htful atti tud e. As a flight instructor, I tr y to
pass on as much of my experience as possible to m y
students. We practise sim ulated emer gencies th at can
be done with a reaso nable m ar gi n of safe ty, b ut I can
only carry th ose simulatio ns so far. Beyond that line
of safe ty I e ncour age pilots to think a bo ut po tential
hazards a nd em erge ncies and try to visu alize what
they would d o - the thou ghtful attitud e. Flying is a
thinking per son's game. The unimaginative pilot is
potentially d angerou s because he can 't visu alize the
r es ults of his decisio ns.
U n fo rtunately, some e mployer s fail to u nder stand
that a pilot needs ple nty of time to th ink abo ut
ever ything r elating to fl ying. T h e boss wh o expects a
pilo t to work too much at no n-flying tasks is pouring
sand into mental mach inery tha t sh o uld be gear ed
fo r the r ealm o f fl ig ht. I deally, a pilot should
approach th e air craft with nothing o n his mind but
getting to h is d estination safely.
We have li ttle difficulty, in a routine e nviro nmen t,
keeping o ur minds worki ng as they sho uld; we
per fo rm all the no rmal cockpit d uties with skill
and efficiency. But when we are fo rced out of our
usual pattern , we must be alert for deficie ncies in
ou r pe r fo rmance. Let's look at an exam ple .
Once I was asked to fl y a high-ran kin g foreign air
fo r ce official fro m Burba nk to Palmdale in a light
twin-e ngine aircraft. I was told to show him extr a
courtesies a nd consideratio n. When I me t him , he
im media tely inform ed me that he was a g r eat pilot,
and q uestio ned my qu alifications. I assured him I
could n o t m a tch his a bility and ch a nged the subject.
After the ru n-up, I called the tower and was 'cleared
o n to hold'. As l swung o n to the r u n wa y,
Gene ra lissimo Ego sh o ved both throttles to the wall
and d eclared , 'I fl y' .
I subd ued m y rage , forgot about the tower's
instr uctio ns to h old, and tried to keep th is m aniac
fro m busting the aeroplane. Wh e n we reach ed the
inter sectio n of the two ru nways, another aeropla ne
flew over the top of us a nd the tower r e m inded me
that I was o nly clear ed to ho ld.
Accidents are ofte n the result of cockpit surprises
that cause our thinki n g processes to qui t func tion ing.
T hese intruders take m an y form s: attitudes,
p ressures, e m ergencies, emotions - anyt hi ng that's
no t part of the ro utine.
A maj or deficiency that ofte n co ntributes to a ircraft
accid en ts is failing to ta ke enough tim e fo r complete
pr e-flight plann ing. A dra ma tic personal example of
how h aste m akes waste occurred at an airshow at the
o ld Cu rtiss-Wright airport on Long I sla nd .
O u r airshow troupe had been push ing a fro n t all the mor e than an ap preciatio n of what's taking place
around them. For example, while walking to the
way across the country fro m California and we had
freque n t del ays because of weather. I was first to arrive aer oplane on a hot da y a t a rem o te airport, yo u note
the softness of the asphalt. Not a breath of air is
- a bout 15 m in utes after showtime. The promoter
stir ring; the press ure altitude a nd th e temperature are
started prodd in g me to get into the air. One of my acts
high. A look a t the performance data shows that the
consisted of a rocket-assisted take-off. The rocket
runway is just long enough.
'
bottle was alread y fas tened to the belly of the
You fire up the turbines and watch the starting
450-ho rsepower Stearman and all I had to do was hook
temps closely. I t takes a bit m ore tha n n ormal power to
u p the ign ition wir e.
With ever ything co nnected and ready, I qu ickly
taxi as the aero pla ne rolls slowly o n h eavy, sticky tyr es.
tax ied the bipla ne to the r unway and , without a
The air condition ing d ucts ar e fogging profusely and
mome nt's hesitation, took off. When I fel t con trol
spitting snow.
effective ness, I d eto na ted the r ocket. The aeroplane
W ith everything checked, you start a tu rn o n to the
jum ped ahead with a tremend o us sur ge and I jerked run way and observe the windsock at the take-off end is
the Stearman into a vertical climb. Then, at about 200 hanging limp while the one at the other end is swinging
feet, the engine qu it - cold.
wildly. You look at the hill about a mile off the
departur e end of the run way and observe d ust spilling
down the slope toward yo u. You shake your head and
a nnounce, 'We'r e goin g to wait a few m inutes.'
'Wh y?' asks your co-p ilot.
'Something tells m e I should ,' you answer.
Perha ps withou t realizing it, in a fe w moments you
had evaluated m any facto r·s that could not be r eadily
measu red, such as pressur e altitude, humidity, rolling
friction, and wind shear. After waiting a few min utes
both windsocks ind icate about 15 knots of wind
blowing down the run way. Now you ta ke off safely.
Ex perience and trainin g are the keys to develo ping
judgment. Eve ry mission and ever y aircraft can teach
you something - if you rem ain alert e nough to see it.
Most of us avoid certain ar eas of flight and ofte n we
should do exactly that. There is a tende ncy, however,
for us to e stablish too much o f a buffer zo ne between
what we consider hazardous and sa fe . This dec reases
our proficiency fo r h andling situatio ns wh ich aren't
routi ne. Training m issio ns allow us LO challenge our
abilities - to m ake a safe mistake - and fo rce our
minds to work under p r essure. Getting the most out of
a training mission builds both skill ar1d judgmenl.
An honest self-evaluation is ve ry impo r tant, but
difficult to develop. I t's often harder to say, 'I'm not
q u alified to fl y that mission,' than to bet your life by
ta king the flight. T he adage that there are no old, bold
pilots is not true, because I know some; but no ne lack
h um il ity.
When the next accident occurs, the next life is lost, it
will be one of us. We will be intercepted by some
T he rocket's location caused the aeroplane to arc
towards the inverted position . I shoved the stic k full circumstance that short-circuits ou r wizardry and
causes us to pe r form as fools. Eigh ty-five per ce nt of all
fo rward but the r eaction was too power ful to
aircr aft accide n ts are caused by h uman factors. So it
o ve.r com e. Sud den ly the aeroplane snapped into a
seems obvious that we are potentially defective a nd
wild , in ve rted gyratio n a nd settled into the den se
column of rocket sm oke. With the nose now pointing need as much working in ou r favour as possible.
One of the r easons most of us choose to fly
towards the gr ou nd, the engine restarted. Using both
aeroplanes is because there is an elemenL or risk
rocket and reci p. power , I regained control and pulled
in volved th at challenges us. Ma ke no mistake about it,
the aero plane from the dive as details o n the grou nd
despite technological innovations and beLter aircr-aft
r us hed sharpl y into focus. I full y expected to ci·ash
performa nce , the risk and the challenge are still wiLh
and, but for the gr ace of God, I would h ave.
us and wi ll continu e to be there in the future.
The cause of this near disaster was my forgetting
Lo turn o n m y all-auitud e fuel system prior to
About the aut hor
take-off. Whe n the stuntplane was pointed straig ht
Mr Mason has a broad background of experience
u p , the gravity fuel system failed and the e ngine
covering 44 years as a p ilot and over 29 OOO fl yin g
q uit. Pe r h aps readers are not as fallibl e as I am hours. He wor ked for Lockheed for 22 years as an
it's my na ture to h urry. But when I 'm around a n
engi neer.ing test pilot a nd was the first person to do
aeroplane, I need the self-discipli ne to slow d own acrobatics in a he licopLer. He now owns and operates
to protect myself from m yself.
Some p ilots seem to have an intuitive ability Lo sense an aerobatic fl ying school in Santa Paula, California,
trouble and avo id it. This intuition is probably nothing
U.S.A. e
Aviation Safety Digest 106 I 13
�Wind shear in Australia
by K. W. Anderson and B. A. J. Clark
Aeronautical Research Laboratories, Department of Defence, Melbourne
November 1978
Fig . 1. Head wind component increasing with altitude
.
Wind shear as an operational problem
re printed in the A viation Safety Digest. In most cases,
Unex pected low level wi nd shear constitutes a
nearby thunderstorms or inte nse rain cells wer e
significant hazard to aircraft d uring landing and
associated wi th the wind conditions. Visual d ifficulties
Lake-off. It has bee n cited as a prime cause in the
(including the absence of VASI informa tio n) were
officia l re por ts of several recent aircra ft accide nts, a nd freque ntly associated with the crash situatio n.
has a uracLed considerable atte ntion througho ut Lhe
In several u ndershoot accide n ts at RA NAS Nowra
avia tio n world .
in the pe riod 1958 to 1964, aircraft experie nced a
Wind shear is defined as a ch an ge in wind speed
rapid increase in rate of descent late o n a p proach to
a nd/or di rectio n occurring in a rela tively sho rt
runway 26 during weste rly winds. Terrain-ind uced
dista nce. Such changes may occu r with height (vertical down draft and misleadin g visua l cues were id entified
wind shear) o r late ral distance (horizontal wind shear). as cau sal factor s. T he p roblem has subsequen tly been
These condi tio ns cause cha nges in airspeed and flig ht relieved by a lar ge earthwor ks programme which
pa th with occasio nally disastrous conseque nces.
effectively extended the eastern end of the airfield
plateau .
Whe n a n a ircra ft is cruising, an y wind- ind uced
airspeed cha nges tend to be negated after a period by a
Meteorological factors and terrain effects
corres pond ing aircra ft inertial speed cha nge. That
Several meteorological factors and the surrot,mding
speed cha nge might follow a height ch a nge a nd the
drag/thrust imbalance created by the original airspeed terrain can cause ch anges (speed a nd direction) in local
cha n ge. Howeve1·, for a ircraft at low level o n approach winds at low level. T hese include:
to la nd, safety margins in he ig ht, speed a nd time a re - lee effects wh ere the area in the lee of an
ob struction con tains waves, rotors, eddies or calm
re lati vely small. If the wind change is rapid eno ugh to
areas;
exceed an aircraft's acceler ation capacity, a nd is large
- contour-following effects whe re th e wind te nds
e noug h lo matc h its airspeed marg in over the
to be d eflected pa rallel to th e grou nd surface
minim u m a pproach speed for the give n configuratio n,
resulti ng in downd ra fts and updrafts as the a ir
then a potential haza rd exists.
flows
over plateaus, r idges and gullies;
With reference to Fig ure 1, for an aircraft making a
- rou ghness e ffects where friction between a moving
stable approach on the requ ired glide p ath , if a rapid
a ir mass a nd the ear th's surface reduces the rate of
red uction in head wind is e ncoun tered the n the initia l
flo w in the lower layers of the atmosph ere. The
e ffects a re those o f rapid reduction of airs peed a nd
thickness of the layer affected depend s u pon wind
d eviation below th e glid epa th i.e. an undershoot
speed , temperature la pse rate and surface
effect. T his requires a thrust increase to regain
roughness. Th rou gh that layer, the wind d irection,
airspeed a nd re turn Lo the glid epa th. H owever, o nce
as well as spee d , will nor ma lly va ry wi th he ight. The
re-stabilised with the reduced wind magnitude, the
gradient height, d efined as the he ig ht above ground
power setting will be less Lhan tha t originally used
of the top o f the friction layer , varies fro m about
before the wind shear e ncounter.
750 ft for smooth sur faces (such as open sea) to
An a ircraft ta king off into the sam e wind structure
a bout 1500 ft fo r rough surfaces (such as large city
will ex perie nce a rapid increase in ai rspeed a nd
centres).
increased climb pe r fo rmance with d eviatio n above the
Wind shears produced by te rrain us ually exist fo r
ex pected climb path.
Conversely, if an aircraft on approach enco unters a ap preciable pe riods without cha n ge and are therefore
regarded as stable.
rapid increase in head wind, as in Figu re 2, then the
O the r sta ble wind shear situatio ns can occur whe n
initial e ffects a 1·e a ra pid incr ease in airs peed and
deviatio n above the glid epath, i.e. a n overshoot effect, a n a rea is affected by a low level j et stream, a marked
req ui rin g red uction o f power in order to retu r n to the temperature inversion or a sea breeze establish ed
glidepath with th e appro priate airs peed . A seconda ry against a moderate p ressure gradient wind . In these
cases, the airmass aloft can have a flow d iffe rent from
haza rd can a rise if the a i1·craft has a high rate of
d escen t, reduced power a nd d ecaying airs peed whilst th at of the lower air.
T ra nsient wind shear situations may cha nge over
close to the g round.
In ad d ition to changes of wind flow in the hori zo ntal periods as sho rt as a few seconds. They a re u sually
associated with chan gin g weather, especially fro ntal
p la ne, ve rtical wind flo ws contribute to wind shear
moveme nt and storms.
e ffects; d ownd rafts from thu nd erstorms are a n
im porta nt example of this effect.
T he wind speed aroun d a thunderstor m varies with
both time and position. I n the ce ntre the re may be
strong updrafts a nd downd rafts, while in th e
Accidents
Since 1970, sever al accide n t re ports which cited wind su r roundi ng air large vertical wind shears may be
evident. A rapid increase in wind speed is
shear or dow ndra ft as causal factors h ave been
14 I Aviation Safety Digest 106
Aircraft landing
tends to undershoot
Aircraft taking off
tends to overshoot
f
"/
Required glide
pat h
Lower stabil ised thrust required
than before shear encountered
characteristic of the fi rst gust of an approaching storm.
Within abou t 16 km of a thunderstorm, large
fluctuatio ns may occu r in an aircraft's vertical and
horizo ntal airspeed regardless of flightpath or ground
speed.
With a cold fro nt, as with thunderstorms, the
associated wind will vary with both time and position.
The passage of the front may be considered as a wedge
of cold a ir which is undercutting warmer air. Some
u pwards motion of the warm air occurs before it turns
to move horizontally away from the fron tal line.
Sud d en tem perature and pressure changes can be
expected at the commencement of the passage, and
heavy rain is o fte n present. The most extreme wind
ch anges in the leading gust line occur when the fron t is
fast movi n g, or the te mperature gradient is large.
H azard o us wind shea rs can exist in the lower layers for
up to o ne hou r a fter the passage of the front.
Sensors
Ground-based systems
Close to an aerod rome, measurement of wind aloft by
equ ipmen t on h igh towers is not practicable, so a
re mote technique is p referred. At present, the only
routine measu rements of conditions in the lower
atmosphere are mad e with balloon flights, a few times
a day at most, at m aj or aerodromes. These
measuremen ts lack the time and spatial resolu tion for
operatio na l use as a wind shear indicator. At the
Defe nce Research Cen tre, Salisbury (DRCS) in South
A u stralia, a n acou stic-sounding technique has bee n
evalua ted as a means of remote wind measurement.
Using ground-based antennae and d igital signal
processing, the system can provide three dimensional
wind d ata for the region 300-3000 ft vertically above
~
_...
I
//
--·/"\
'
Aircraf t f light
path
the antennae. Some difficulties with ambient noise
have been experienced and alternative sensing
techniques have been reviewed. Other studies in
acoustic sounding are progressing at RAAF Point
Cook and Boulder, Colorado.
Another system of ground-based sensors has been
used to detect gust fronts by measuring small jumps in
temperature or pressure.
Airborne system s
It has been claimed that some aircraft-based sensors
are useful in detecting wind shear. These include: (i)
angle of attack instrumentation; (ii) the NASA total
energy mo ni tor system which d isplays the rate of
change of the combined kinetic and potential en ergies
of the aircraft; and (iii) the Safe Flight device which
computes the rate of change of horizontal wind and
the downdraft drift angle. All of these devices are aids
to the recognition and management of a wind shear
that the aircraft is currently encountering. They are
not forewarn ing devices for that aircraft.
Questionnaire detail
Apparently, no systematic investigation had been
made either in Australia or overseas about the wind
shear experiences of aviation personnel. It was
therefore expected that a ques tion naire survey
directed at Australian pilots and air traffic controllers
(A TCs) would yield valuable information about the
extent of any difficulties with wind shear, and could
also provide guidance in the development of
techniques for combating wind shear if these proved to
be necessary or desirable. For reasons of expedience,
the survey was restricted to mili tary pilots and ATCs,
civil regular public transport (RPT) pilots and DoT
aerodrome controllers.
Aviation Safety Digest 106 I 15
�,_,
The survey was aimed at operators whose
experience was relatively recent, and so an attempt was
made to exclude- persons who had not been fl ying or
controlling air traffic during the preceding 12 months.
Table 1 gives the numbers of eligible persons (i.e. those
having r ecent experience) in each group, together
with the chosen number of persons within each group
to whom a questionnaire was dispatched.
Eligible
population
Number
sampled
Percentage
6 13
95
65
1960
408
95
65
196
67
100
100
10
P ilots
Air Force
Army
Navy
RPT
Air traffic
controllers
Air Force
Army
Navy
Dept of
Transport
233
25
12
158
25
12
67
100
100
l OOO
76
8
Table 1
Where the sample size was less t han l 00 per cent, a
technique for subject selection was required to e nsure
an even distribution of the sample throughout the
parent gro up. Whe re possible, selection was arranged
to give a representa tive cross section of experience.
T h e following subject areas were included in the
survey:
- understanding of the effects of wind shear ;
- understariding of the various d efinitions;
- reading in aviation journals about wind shear ;
- cu es for anticipation of wi nd shear ;
- cues for recognition of effects of wind shea r;
- approach stra tegy in va rious wind condition s;
- estimation of degree, location and frequency of
wind shear conditions;
- susceptibility of different aircraft types to wind
shear conditions; and
- opinions of the content and timing of vario us
proposed warning messages.
Table 2 shows the numbers of q uestionnaire
respondents in relation to the number of
questio nnaires dispatched, for each functional group.
Questionnaires Questionnaires
disjJatched
returned
Percentage
Pilots
Air Force
Arm y
Navy
RPT
Air traffic
controllers
Air Force
Arm y
Navy
Dept of
Transport
408
95
65
196
271
65
33
93
67
68
51
47
156
25
12
109
17
8
70
68
67
76
56
74
Table 2
Most respondents appeared to react positively to the
survey. More than half of those who answered and
16 I Aviation Safety Digest 106
'
re turned the questionnaire wrote a para.graph
or more
in the general comments space. Most gave written replies
where invited and many expanded on the multi-choice
a nswers as well.
Some responde nts were clearly unfamiliar with
wind shear problems. For them the sur vey served as an
educational aid by implicit coverage of certain aspects,
and as a catalyst for subsequent discu ssion with their
colleagues.
Questionnaire findings
Frequency of wind problems
Wh en asked to estimate the frequen cy of dangerous
conditions due to wind shear, wind gradient or downdrafts,
respondents produced widely differing answers. Some
respondents commented that the word dangerous was
subject to various inter pre tations.
Among ATCs, the controllers at Nowra (Navy),
Perth (civil) a nd Jandakot (civil) selected the highest
average freque ncies o f monthly to three monthly. The
lowest freque ncies of once in 3 to 10 years were
_
produced by Adelaide controllers. The numbers of
controllers at the various locatio ns are h owever too
small for statistical reliability o n this aspect.
Many pilot respondents made no estimation at all.
The number of non-zero answers is given in Table 3.
T he estimations per ta in to the number of dangerous
situations in the fl ying career of each respondent. For
comparison, the question naire also sought similar
figures for wake turbulence problems.
I
- Wind shear
Wake turbulence
problem
problem
Take--Off Landing Take-off Landing
Civilian
pilots (93)
Military
pilots (369)
25
54
9
12
92
189
100
164
Table 3
Civilian pilots were asked to estimate how often wind
proble ms migh t cause each of them to induce a
go-arou nd on landing. Approximately half of the
respondents gave a non-zero answer; this was nearly
always less than five times per year.
In most res pondent grou ps, the number of
individuals wh o estimated the wind s hear problem as
greater than the wake tur bulence problem exceed ed
those with the o pposite opinion by a lar ge ratio. In the
case of Air Force pilots, however, this ratio was much
smaller. Many of the respondents selecting wa ke
turbulence as the greater problem made reference to
formation fl ying.
Approximately half of the resp onding pilots
described a condition of some wind difficu lty, but
man y of these were surface problem s (such as
crosswinds a nd gustiness) or cruise problems (such as
clear air turbulence and mountain waves at higher
levels).
Of 143 accounts of low level wind difficulty,
sufficie nt information was given with 13 1 to allow the
follow ing categorisatio n:
- vertical shear of h orizontal wind
31 reports
47 reports
- downdraft
12 reports
- shieldin g effects
- frontal and Lhunderstorm
15 reports
- wake tur bulence
26 reports
I
The wake turbule nce incidents seemed to be the
most hazardo~s.
Worst aerodrome
When asked which Australian aerodrome had the
greatest wind shear or downdraft problems, about half
of the A TC r espondents named the aerodrome at
which they were currently working. Laverton and
'Perth we re the most named by m ilitary a nd civilian
ATCs respectively.
Among civilian pilots, the most named aerodromes
were Perth, Sydney and H obart. When related to
traffic density at each location, Hobart and Perth are
particularly prominent. Among military pilots,
Nowra, Pearce, and Laverton were clearly identified in
that order.
Many respondents elaborated on the features of an
aerodrome which they believe cause or are associated
with wind problems. The main featu res nominated
are:.
- runway elevated above the surrounds;
- aerodrome in the lee of mountains;
- in ru gged terrain, where short, uncontrolled and
one-w;ry strips are used;
- non-uniform airflow occurring over the aerodrome
surface giving conflicting windsock information;
- a pproach paths crossing water;
- noise abatement procedures discouraging the use
of the run way wi th the most favourable wind
structure.
Worst aircraft
Pilot respondents were asked their opinions on which
aircraft type is most affected by wind shear problems
on a p proach. This seemed to be variously interpreted
as:
Which reacts the most? or
In which. is recovery most difficult? or
In which is detection most difficult? or
Which is most critical in the landing configuration?
A noth er proble m in the corn parison of aircraft types
is that cer tain career streams have only training
a ircraft in common (e.g. among pilots with experience
o n the Caribou , ve ry fe w had experience on Mirage,
Porte r, F-11 l C or CT4A).
Afte r due con sideration of each pilot's nomination
in relation to his experience, the Caribou and the
Dako ta appeared to be regarded as the most affected
fixed-wing mili tary a ircraft.
Helicopter pilot r es ponses were analysed similarly.
Among RAAF pilots, the Iroquois was considered
worse than the C hinook. Among Army pilots, the
Sioux and the LOH (Bell 206) were thought worse
than the Iroquois. Among Navy pilots, I roquois and
Wessex were regarded as being worse than the Sea
King.
A rotary-wing versus fixed-wing comparison was
asked only of pilots with adequate experience on both
classes of aircraft. The following conclusions were
draw n:
Responding p ilots who were currently rotary-wing
aircraft pilots mostly favoured the fixed-wing worse
option.
Responding pilots who were currently pilots of
Caribou, Tracker, Dakota, Porter, and CT4A
aircraft mostly favoured the fixed-wing worse option.
Responding p ilots who were currently pilo ts of
Hercules, Orion or Mirage aircraft mostly favo ured
the rotary-wing worse option .
From civilian pilot respondents there was a clear
trend for swept-wingjet transports to be most named
as the most affected aircraft. Of these the B-727 and the
B-707 were prominent. Qantas pilots usually named
the B-707 from an experience profile including B-74 7,
Electra, and DC-3. T AA and Ansett pilots }!Sually
named the B-727 from profiles including the DC-9
and F-27. Those with no B-727 experience usually
named the DC-9, while pilots with no jet experience
usually named the DC-3 as worse than the Electra or
F-27. Civilian p ilots were not asked about rotary-wing
or general aviation aircraft.
Many respondents elaborated on the features of the
ai rcraft which they believe are associated with the
aircraft's susceptibility to wind shear.
For light aircraft, wing loading and low approach
speeds (by comparison with a given wind change) were
often cited. For transport aircraft, momentum and
power/mass ratios were often stated to be the major
parameters. For jets, en gine response times and the
lack of propeller slipstream over the wing were stated
to be important. The position on the drag curve a t
which the aircraft operates during approach was said
to be a factor for delta and swept-wing aircraft.
STOL aircraft tend to operate in rugged areas with
short runways. Consequently, steep slow approaches
using high lift devices are used. H igh pilot workload
associated with such operations, together with minimal
approach speeds were cited by some responden ts as
facto r s. Helicopter pilots cited operations of high
aircraft mass for the given density altitude. The mode
of operation (confined areas and pinnacles) was
tho ught relevant h ere also. The requirement for a zero
touchdown speed was also mention ed as sometimes
important. Some cited high workload on landing in
aircraft in which the pilot has no co-pilot or navigator
to assist.
Understanding of wind shear terms
The questions at the beginning of each questionnaire
served to establish the subject as well as to survey the
popular understanding of some relevant terms.
The question: What is wind shear? yielded an
emphasis on the abrupt change of wind . . . answer
among all groups of respondents. Some emphasised
similarity with words like gustiness and turbulence.
The question: What is wind gradient? yielded an
emphasis on the progressive change in wind speed . . .
answer among all groups. It was sometimes noted that
the gradient wi nd was the wind interpreted from the
pressure gradient or isobars shown on meteorological
maps.
The question : Which. of the follow ing terms do you think
is correct when the headwind decreases on descent during ·
final approach.? has the following answers which are
correct by definition.
Negative shear (as opposed to positive shear) i
H eadwind shear (as opposed to tailwind shear)· :
Forward shear (as opposed to reverse shear)
Undershoot shear (as opposed to overshoot shear)
In the multi-choice an swers, the last of these pairs
was offered only in the civilian ver sions of the
questionnaire.
For military respon dents, the headwind/tailwind
option was the most favoured a nd also the best
a nswered as judged by the correct/incorrect ratios.
However, more than half of the military respondents
Aviation Safety Digest 106 / 17
�se lected unfamiliar with these terms rather than either of
those optio ns. ·
Civilian A TCs mostly preferred the positive/
negative shear te rms, a nd civilian pilots mostly
p referred the overshoot/undershoot shear option.
And while fewer civilian pilots selected unfamiliar with
these terms the correct/incorrect ratios were lower tha n
for military pilots.
Unsolicited comments suggested that the
understa nding o f wind varia tion p roblems is related
~eavily to .experien~e , and tha t formal training has
included 11ttle menuon of the subject.
Detection of wind difficulties
ATCs were asked: What do you actually use to detect wind
shear or wind gradient so that you can advise pilots on
approach? Multiple selections were allowed. R eports
from aircraft and experience with local conditions were
most popular. Visual factors (cloud, smoke, dust, etc.)
and mete orological cues were less frequently noted.
Approximately 16 per cent of respo ndents selected
(there is) usually not enough information to judge. Most of
the milita r y responde nts with Ground Controlled
Approach (GCA) qualifications selected observations of
aircraft on Precision Approach Radar (PAR) as an
importa nt cue.
E xperience with local conditions was the most popular
a nswer by pilot groups to the question: What cues do you
actu ally use to anticipate a wind sliear or wind gradient on
final approach ? Visual cues (su ch as smoke, cloud, trees,
te rrain, surface texture) were the n ext most freque nt
re ply fro m pilots of helicopte rs, H e rcules, Caribou
a nd Arm y aircraft. For othe r pilots, me teorological
correlates (such as turbulence a nd thunderstorms) a nd
ad vice fro m others - including ATC, Automatic
Termina l Information Service (AT IS) and other
a ircraft - were selected more freque ntly than visual
cues.
Military pilots selected visua l drift observations
more frequently than observa tions from aircraft
instrume nts. T h e reverse was true for civilia n pilots.
The question on aircraft response in wind shear
(decreasing headwind) or downdraft situation s
yie lded increasing rate of d escent, d ecreasing
airspeed , and glideslope de p artures as the major cues.
Pitch and a ngle of attack were each selected by less
than 20 per cent of r es ponde nts. Army pilot
res ponde nts noted yaw a nd wing d ropping more tha n
other groups, es pecially in wind shear as o pposed to
downdra ft.
T o distinguish between wind shear (decreasing
head wind) and downdra ft, several pilots suggested
that downdrafts generally ca used a quicke r respo nse
(es pecially in r ate of d escent a nd glideslope
d e partures) tha n win'd shears. Others suggested that it
was difficult or unnecessary lo distinguish .
Variatio ns in the runway picture - includ ing visual
a pproach slope indicator syste m (V ASIS) information
- a nd the rela tionship be tween airspeed a nd rate o f
descent (no t conseque nt upon an y pilot control inputs)
were also cited as subtle cues to wind shear and
downdraft. So me civilia n pilots of aircraft equipped
with Do p pler or ine rtial n avigation system (INS)
equipme n t claimed to use their equipment to measure
wind a loft (for comparison with su rface wind as
advised ), to d e tect any chan ge in wind alon g the fligh t
path as it occurs, and to distinguish between
18 I Aviation Safety Digest 106
downdra ft and w"ind shear. This technique was less
popular with military pilots, especially in single place
aircraft where pilot workload wo uld preclude an y
regular monitoring.
Approach technique for wind shear
Pilots were asked how they would alter the ir approach
speed if they knew that the win\d at 500 ft was different
from the surface wind . Most selected no change. Some
noted that they would not know the wind at 500 ft, at
least not confidentl y. Others stated thatthere was plenty
of time for correction below 500 f t.
Those who said that they would alter their approach
speed in such conditions included 60 per cent of
Boeing pilots, a nd 40 per cent of pilots of propeller
transports (including HS748, Caribou, Dakota, F-27,
Ne ptune, but excluding H ercules).
The various methods of altering the approach
mostly involved a further margin added to the
a pproach speed. These included:
- add the shear (understood to be the wind differe nce
between the ground and 500 ft);
- add five to 10 knots;
- u se 500 ft wind instead of surface wind in
calculating the approach speed; a nd
- aim for a minimum ground speed.
Other cha nges to the flight configuration included:
- u se less or no fla p;
- fly a flatter approach path ;
- fly with a higher power setting (to avoid j et en gine
r es po nse lag);
- fly a d ecelerating a pproach allowing ai rspeed to
bleed off;
- have the navigator , first officer or co-pilot call the
wind ever y 10 seconds (whe n suitable instrume nts
are available);
- a im for a long touchdown; and
- be read y for a go-aro und.
It should be e mphasised that the various techniques
re fe rred to above ar e those quoted by pilots and do not
necessarily carry any endorsement from aviation
authorities or operators.
For ST OL a ircraft pilots, the occasion when they
expect wind cha nges (irregular terrain, e tc.) is o ften
just the situatio n in which they want th e ir a pproac h
speed s to be minimal because of the tende ncy fo r
runways to be sho rt at remote locations. This is in
direct conflict with ma ny of the above. Some pilots
re ferred to other limits to approach speed such as
runway surface, braking a bility, la nding gear and fla p
sp eed limits, etc.
Several pilots, milita ry and civilian , refe rred to
pressure to acce pt a duty runway at city airfields with a
downwind component of up to I 0 knots. Because of
problems relate d to excessive g round speed, the y we re
reluctant to add margins to their a irspeed in such
circumstances.
Militar y A T C respondents with GCA qu alifications
we re asked about alte ring the approac h p ath o f a n
a ircraft in anticipa tion of a wind shear. T he majority
gave an a ffirm a tive answer . Deliberately bringing the
a ircra ft in high o r to one side o r the early correction o f
expected d rift were commonl y quoted as strategies.
Some o f those giving a negative answer indicated that
they though t that a shear is never 100 per cen t
predictable, and that an incor rect prediction called for
d angerous cor rection s late in the approach . H owever ,
Aircraft taking off
tends to undershoot
Aircraft landing
tends to overshoot
---.....,/
Aircraft flight
path
.I
//
'Required
glide path
Fig. 2. Head wind component decreasing with altitude
the m ajority view was that a modified a pproach path
helped to ma ke precise touchdowns possible when
wind changes along the approach pa th were expected.
opera tional options exceeded the number selecting
the o peratio nal options. Expla nation o f the Army
pilots' attitude ranged from the desire to be
inde pende nt and continue to u se visual exte rn al cues
Warning messages
primarily, to the expecta tion that suita ble equipment
For examples of typical messages curren tly given in
would be located only a t m ajor airfields, a nd the refore
Australia, bo th pilot a nd ATC groups cite d a state ment not o fte n u seful to the m . There was also some
of existe nce such as:su ggestion from all groups that a n air-transporta ble o r
Caution, wind shear or
aircraft-mou nted d evice might be received mo re
Previous aircraft advises wind shear on approach.
enthusiastically.
Occasiona lly, a qualitative state me nt of degree or
The questionna ire asked about the wording of
locatio n of the shear was included, e. g.
possible messages fo r pilo ts on approach . The civilia n
Severe wind shear on short final.
version of the questionnaire containe d more question s
T he condition fo r the use of the warning messa ge on this aspect tha n did the militar y ver sions.
seeme d to be eithe r:
The sim p le sta te me nt of wind speed at one or two
- whe n a previous aircr a ft made a report; or
h e igh ts above terrain (as well as surface wind) was
- as a standard procedure when a certa in runway was reaso nably popular with most groups a nd dre w no
in use, e.g. Nowr a runway 26.
criticisms. Qualita tive messages were not freque ntly
Amon g unsolicited comme nts, complaints abo ut the nominated . Some pilots pointed out that wha t is seve re
for one aircraft may be mild to a nother.
inaccuracy of surface wind advice was the most
Ai rcraft reactio n type messages (e.g. expect loss o f
.common. Pilots suggested tha t this was the result o f
anemomete r location rather than A T C's vigila nce, and airspeed , o r expect increasin g rate o f descent) were
was a proble m at some airfie lds onl y. It was su ggested gene rally not favo ured over wind d escriptio n type
by some that this was a greater proble m tha n the lack o f messages, al thou gh some pilots said tha t the fo rme r
required less mental processing a nd might be be tter
accurate info rma tion about wind aloft.
In additio n, seve ral pilots passed comme nts o n the understood in a critical situatio n.
Militar y pilots, in selecting the ir pre fere nces,
distracting nature of additio nal information whe n the
pilot is in volved in a seque nce ofla nding checks as well avoided the phrases headwind decreasing, and loss of
airspeed. Indeed no indication of the direction o f the
as monitoring variou s instrume nts and possibly
shear was commonly se lected , other tha n that implied
external visual cues. Unless the information is of
considerable importa nce, perha ps the pilot would be in the wind-a t-altitude type message. Other favoured
better o ff without it, some suggested. In justifying that te rms amo n g the military pilots were simila r to the
opinio n, o ne pilo t asserte d that a n educated guess was ones in cur re nt use, i.e. exjJectwindshear, or, for a more
detailed a nd qua ntita ti ve ve rsion , expect 2 0 knot wind
almost as good as accura te knowledge of wind because
of the health y margins built into the approach spee ds shear at 200 ft. The latte r migh t be supplied in more
o f most aircraft.
severe conditions or on request.
In contrast with the militar y pilo ts, few civilia n pilot
Pilo t respond ents were asked which aspects of flying
responden ts selected a message with no clue abou t the
(training, conversio n, operations etc.) would bene fit
most fro m the availability o f wind shear ad vice. Most direction of the shear. T he wind-at-altitude type
responde nts selected the ope ra tional type of an swers message was preferred as AT IS ad vice. Boein g pilots
which would e ncom pass their own ty pe of fl ying. T he a nd es pecia ll y B-74 7 pilots were pro minen t in this
prefere nce. Other than the wind -at-altitude type
only exception to this occurred with Arm y pilo ts, fo r
message, expect 20 knot increasing headwind below 500 ft
whom the number o f pilots selecting the no nAviation Safety Digest 106 I 19
�A pilot's views
on kangaroos
In.response to the article in Aviation Safety Digest 103, concerning animals on aerodromes, one of our
readers .provided the following views:
·
----iflll'
-- - - - Glide Slope
---------Flight Path
Fig. 3. Typical wind shear associated with thunderstorm.
airspeed, and visual estimatio ns of glidepath angle and
rate o f cha nge of glidepath angle.
For de tection of wind problems, ATCs usually have
Conclusions
only pilot re p orts and experience with local weather.
Significant factors
Some military aer od romes are, however, fi tted with
The analysis of the p ilot and ATC questionnaire
PAR and after obser ving the flight path of several
re plies identified several places a nd me teor ological
approaching aircraft, th e GCA controller can often
conditions which a re commo nly associated with
me nta ll y mod el the wind structure in terms of its effect
reports of wind shear condition s in Au stralia. For
upon aircraft, an d some of them claimed lo allow fo r
example, terrain-induced downd rafts at Nowra, Perth this in their guidance strategy.
a nd Pearce, and thunderstorm situa tions at Sydney
Whe n data are available (e.g . re ports from I NS- or
and Brisbane were clear tre nds.
Doppler-equi pped aircraft, or fro m other en counters
Pilots of helicopters a nd ligh t tran spor ts o pe rating with wind shea r ) indicating con siderable di ffe re nces in
in irregular te rrain (such as m oun tainous a reas, fo rest winds at vario us altitudes, there is good reason for
areas, near city buildings, etc.) are often exposed to advising pilots of n earby aircraft. T his will be u seful in
local wi nd proble ms induced by the te rr:ain. Shielding planning the a p p roach strategy, especially for stable
and pinnacle effects are examples. Altho ugh the
shear situatio ns. T he qu estionnaire responses indicate
affected areas may be o f limited vertical exten t, such that a simple message ad visi ng the wind speed and
regio ns can contain large wind ch an ges and a re
direction at a h eigh t of 400 ft above ground (as well as
consid ered by these pilots to be the maj or wind shear al the surface) wo uld be accepted , understood and
problem fo r the m. Vis ual cues for the landing task can inte rp reted as well as a ny other verbal message.
be distorted in rugged areas (as a result of loss of
Whe n forewarned to expect a cha nge of win d speed
horizon refere n ce, irregular sha p e or slope of fie ld or o n a pproach , pilots would be be tter prepared for the
str ip, etc.) so that glideslope a n gle estim ations are
encounter and therefore should respond more safely
more d iffic ult for the p ilot, even in condition s of good th a n o therwise.
·
atmos phe ric visibility. Acco rd ingly the early
recognition of wind shear symptoms is p robably more Acknowledgements
difficult in re mote areas than at most regular
The value of this s urvey rests largely on the quali ty of
aerod ro mes.
the answers su bmitted by the 652 respon dents. Most of
Coping with wind she ar
the re turne d q uestion na ires ap peared to have been
T he questionna ire results su ggest that pilots and
answered tho u gh tfully an d si ncerely, and particular
ATCs have a diverse understa nding of wind shear, its than ks are d ue lo those who did so.
e_ffects and its jargo n. The topic has, in the past, not
An information pape r entitledA Questionnaire Survey
been well covered in form al tr aining. Local knowledge of Opinions of Pilots and Air Traffic Controllers on Wind
h as been d eveloped wh ere needed , b ut has not a lways Shear in Australili is available u pon request from th e
been published in the ap prop riate aerod rome guides. C hief Superi nte nde nt, A RL, GPO Box 433 1,
In wind shear conditions, the most useful cu es
Melbourne, Vic. 300 l •
available to a pilot are ge ne rally rate of descen t,
was the most pq pular , especially as a message from the
tower (as o pposed to the A TIS).
20 I Aviation Safety Digest 106
' I a m a private pilot with 550 hours, mostly gained
since 1974 in operatio ns, by day and night, at private
airstrips in the west and north-west of New South
Wales.
' I n m y limited experience, I have concluded that
there is no cure for the problem of kangar oos short of
mass exter m ination which, though a desirable ideal to
all countr y people, is somewhat impractical to
im pleme nt. So, since I am unaware of a ny remed y to
the proble m, it becomes a matter of prevention.
' I t is well kn own th a t these useless, good-for-nothing
bludgers (no love lost between country people and
kangaroos) a re far more active by night than by day,
and peak activity can be expected in the hour o r so
e ither side of first a nd last light. Perhaps a lesser
known fact, but verified by my obser vations an yway, is
that 'roos r un in pairs o r multiples of pairs - it is most
un us ual to see one run ning alone.
'Armed with this information I restrict m y
operations as far as possible to broad daylight. This
proced ure provides reasona ble safety simply because
th e better the visibility, the earlier th e warning you will
have of a ny kan garoo movement. Yes , I have seen the
flea-bitte n mo n grels by day, however I have never
been concerned by the sight of a 'roo bounding across
the runway 100 metres ahead of me - he will be well
clear - but it is his b····· mate bo unding along beh ind
who is the problem.
'H avi ng being confronted by this situation duri ng
both take-off and landing phases, I can make some
comments about bush fl ying that may be of assistance
to other pilots, particularly those not accustomed to it.
• At the risk of sounding like a salesman , whic h I am
not, a Cessna is the best aircraft to use and, as long as
it is not at max. all up weight, a n y Cessna will do. If it
is at max. all u p weight, make sur e it has the power
to permit the sort of manoeuvres th at are
occasionally required - maybe a l 72XP but for
preference , nothing less than a 180 or 182.
• Whatever the aircraft, know it - and know it well.
Be sure that you can operate it by feel. If you are an
ASI-hog you will not be able to spare the time
necessar y throughout the take-off or landing to be
watching all around for kangaroos - or other
animals either, for that matter. Wild pigs can be a
he~I of a problem and cattle are a straight out b·····
nuisance.
(continued on page 31 )
Aviation Safety Digest 106 I 21
�Failure to recognise wind shear
conditions
Moments after taking off from Tucson International Airport, Arizona, USA, a Boeing 727 struck power lines
and two 39 foot poles, the first of which was about 216 metres from the end of the runway. The aircraft was
substantially damaged but remained airborne and the crew, after assessing the damage, landed the
aircraft safely back at the airport. None of the 84 passengers or seven crew members was injured.
The aircraft was operating a scheduled passenger
service from Houston, Texas to Los Angeles,
California, with several intermediate stops inclu.ding
Tucson.
Before the flight crew started the engines
preparatory to taxiing from the terminal building at
Tucson, the airline's station agent prepared the weight
and balance form for the flight. The sheet was
completed for a 15 degree flap take-off on Runway
l lL, the active runway at the time, and was based on a
tern perature of 35 degrees Celsius and a gross take-off
weight of 62 580 kilograms. While parked at the
terminal, the crew received a wind report of 210
degrees at 18 knots, gusting to 25 knots, and the
second officer pre pared the take-off data card for a
departure from Runway 29 R. The computed critical
engine failure speed, or decision speed (V 1 ), and the
rotation speed (VR) were both 123 knots, and the
take-off safety speed (V2 ) was 138 knots. Before
taxiing from the terminal however, Runway 21 was
selected instead of Runway 29 R, because it was now
the active runway and the wind velocity exceeded the
cross-wind limits for Runway 29 R.
After the aircraft began to taxi to Runway 21 for
take-off, the second officer computed the weight for a
Runway 21 departure and advised the captain, 'Well,
we're over-grossed without wind.' He also said that a
headwind component of 10 knots was needed to meet
take-off weight requirements.
During the next few minutes there were numerous
rapid changes in wind strength and direction. The
tower controller transmitted a series of reports in
which the direction of the wind varied between 120
and 240 degrees, and the strength between 13 knots
and 40 knots, with gusts to 50 knots. The last reported
wind - 170 degrees at 13 knots - would have
provided a 10 knot headwind component at the start of
the take-off roll on Runway 21.
While the aircraft was taxiing, a dust storm passed
over the airport and a discussion between the crew
members about the blowing dust was recorded on the
aircraft's cockpit voice recorder (CVR). The storm
lasted about six minutes a nd, in the reduced visibility,
the crew had difficulty following the taxi route to the
runway. After being told by the tower to make a right
turn on to the next taxiway, the first officer replied,
'Okay, we got to find it first'. A few mome nts later,
according to the CVR, the captain comme nted, 'This is
just a short-lived thing, by the time we get out there, it
will be all gone I think'. Two minutes later, the aircraft
was finally in position and the tower cleared it for
take-off.
Runway 21 at Tucson is 2134 metres lon g; for
landing, there is a 152 metre displaced threshold, but
for take-off, th e e ntire length of the runway is
available. T he taxiway the 727 used enters the runway
22 I Aviation Safety Digest 106
152 metres in from the approach end at the same point
as the displaced threshold. After taxiing on to the
runway however, the 727 did not back-track to use the
full length but instead, began to take off from the
intersection of the runway and the taxiway, leaving
an available distance of 1982 metres.
The captain said that, for take-off, he used normal
take-off thrust and a flap setting of 15 degrees. The
number one engine was slow to reach take-off power
but at 80 knots, all instrument readings were within
take-off limits. According to the CVR, 42 seconds after
the aircraft was cleared for take-off, the captain
exclaimed, 'Hang on, guys' and two seconds later again
another unidentified voice called, ' Keep it goin g'.
Later, the captain recalled, 'As we rotated, nothing
happened. It seemed like quite a long time before we
were getting off the runway at all. We assumed we
were just slightly off the runway. When I noted that we
weren't climbing, I glanced at the airspeed again and
noticed that we were slightly above V 2 • I increased the
pitch attitude above the normal take -off climb and
again no ted no climb. Then I noted the airspeed
dropping off rapidly. 1 then also observed the wires
and that we were going to hit the wires. I decreased the
nose attitude to the normal pitch attitude for take-off
and applied full power'. He said that he lowered the
nose because he was concerned with 'control'. The
captain said he did not consider abandoning the
take-off at any point on the take-off roll.
The read-out from the aircraft's flight data recorder
(FDR) showed that in the five to six seconds before the
aircraft hit the wires, the indicated airspeed varied
from about 145 knots to 130 knots. T he FDR showed
that after the aircraft struck the poles it accelerated
normally through 160 knots. Once clear of the
obstacles, the crew checked the aircraft's flight
characteristics and, after advising the tower they were
returning to the airport, landed normally on Runway
29 R.
Parts of the two poles and the power lines were
scattered along the flight path of the aircraft and
pieces of the poles were embedded in the airframe.
Both wings, the lower fuselage and the landing gear
doors were h eavily damaged. The lower surface of the
left wing and the entire length of the leading edge
flaps showed electrical arcing burns. The lower wing
had been punctured in several places cau sin g internal
damage and fuel leakage. The r ight wing had been
severely dented and punctured near the leading edge
flaps and slats while on the lower fuselage, water and
fuel drain masts and a n a nten na were torn off.
Meteorological information
At the time of the accident, the following wind warning
was in effect for t he Tucson area but had not been
transmitted to the tower:
'Scattered thunderstorms in the Tucson area may
produce some wind gusts to about 40 to 55 mph this
afternoon and evening along with brief blowing dust
lowering visibilities to less than a mile. Precipitation
will be spotty and generally light. Caution is advised
when blowing dust is visible as wind gusts may be
quite strong nearby.'
This warning was issued 13 minutes before the
Boeing 727 took off but was not received in the Tucson
control tower until 11 minutes after the aircraft had
departed. The weather observer explained that
transmittal to the tower and other facilities was delayed
because of the rush of events and other priorities.
Later, whe n referring to the wind conditions at the
time of take-off, the captain said that, 'Noting the
conditions under which I was taking off, I wanted to
u se all the available runway and I made a point in m y
mind, as I was taxiing, to go over the bar which crossed
the runway and to get as much available runway as
possible for take-off. ' When the aircraft arrived at
Tucson, it landed on Runway 21 but the captain did
not recall seeing the d isplaced threshold during the
landing. The captain said he had not been into Tucson
Airport for about three years before the accident and
though he and the first officer referred to the airport
diagram in the approach char ts, they did not see the
displaced threshold depiction.
The captain added that before take-off, he was
concerned about the high gusty winds and the dust
that was blowing, a nd 'since I was already taxiing at
that time, I decided to wait and see and continue
taxiing. As the dust storm passed, I could see out m y
left window and it was clear . .. It appeared that
ever ything was back to as before.' The captain stated
that he did not anticipate the possibility of a wind shear
because 'my previous experience with wind shear is
that the winds are quite variable, as much as 180
degrees and, as far as I am concerned at this time, the
wind was predominantly out of the southwest .. .'
A pilot in a runway supervisory unit at the end of
Runway 11 L, said that shortly before the accident, the
winds were variable from the south-west to the
north-west at 10 to 30 knots. He added that the wind
speed and direction differed between each end of
Runway 11 U29 R. About the time the 727 took off,
he noticed virga - streaks of precipitation which
evaporate before reaching the ground - in most
quadrants and a circular wall of dust move over the
airport from the south-west.
Another pilot who watched the 727 take off said that
'as the a ircraft broke ground, it yawed abruptly to the
right as (if) it had weather-vaned into the wind.
Simultaneously with the weather-vaning, the aircraft
moved laterally to its left a distance of 15 to 30 metres.'
Two firemen observed that, when the aircraft passed
the intersection of Runways 29/ 11 and 21/03, a
windsock near the intersection indicated no wind.
Flight recorder
The FDR readout began at a point where the aircraft
turned on to the runway to begi n the take-off and
ended when the aircraft reached an altitude of about
4200 feet above mean sea level. The altitude and
heading traces were stable u ntil the aircraft lifted off.
At that time, the recorder data trace showed an eight
degree heading ch a nge to the right. The altitude trace
showed a slight climb after lift-off followed by a slight
descent after impact with the wires and poles, and.then
a normal climb profile.
The recorded airspeed increased erratically from
zero to 110 knots ( 13 knots below V 1) and then
fluctuated around 11 0 knots for about 12 seconds
before increasing. Eight seconds before the ',V 1 rotate'
call, the recorded airspeed dropped to 94 knots and at
four seconds before V 1 it recovered to 11 4 knots. Four
seconds after the 'V1 rotate' call, the airspeed reached
about 142 knots, then began to decrease to about 130
knots at impact. After the aircraft struck the poles, its
airspeed increased rapidly to about 156 knots, then
increased slowly to the highest airspeed recorded 185 knots - during the climb-out.
The information from the FDR was analysed to
determine the probable wi nds into which the aircraft
flew and whether the aircraft could have successfully
cleared the poles during the take-off.
Wind effect
Theoretical aircraft performance was compared with
actual aircraft performance as recorded on the FDR.
Since all aircraft systems, including the engines and
the flight controls, were operating properly,
d ifferences between the actual and theoretical
performance were assumed to reflect the effects of
winds.
The plot of the derived horizontal winds indicated
that the aircraft encountered a headwind component
of more than 40 knots at the beginning of the take-off
roll. This headwind component decreased to
essentially zero at a point about half-way down the
runway. From there, the wind experienced by the
aircraft changed to a tailwind that averaged about five
knots until lift-off. After lift-off, the tailwind increased
at a rate of about 4.5 knots per second to a maximum of
about 28 knots at the first power pole.
The FDR data indicated that just after impact with
the pole the airc raft apparently encountered an
abrupt shift in the wind which permitted it to assume a
near normal acceleration schedule.
The derived wind model contained only headwind,
tailwind and crosswind components. Investigators
believed that at 30 feet above ground level, vertical
wind velocities wo uld be negligible. The presence of
relatively high horizontal winds supported this
assumption.
Take-off performance
In order to determine wh ether the aircraft could have
cleared the poles during take-off, the required rate of
climb was calculated for two flight profiles:
- Ave rage rate of climb required to miss the poles
from the point at which it was realised that obstacle
clearance would be a problem.
- The average rate of climb provided by sustaining
the highest probable pitch attitude reached by the
aircraft after lift-off.
In the first case, it was determined that when the
problem of obstacle clearance was recognised, the
angle of attack could h ave been increased to
temporarily establish a steeper flight p ath and clear
the poles. Assuming that a d ecision was made by the
pilot at a point about 216 metres from the obstacle and
20 feet above the grou nd at an initial airspeed of 135
knots indicated airspeed (KIAS), the average rate of
climb required to clear the obstacles b y 20 feet in
Aviation Safety Digest 106 I 23
�no-wind cond itio ns would have been 780 feet per
minute. If flown in winds id entical to the d e rived wind
profile, the average rate of d eceleration at 780 feet per
minute r ate o f climb would h ave been a bout 2.2 knots
per seco nd . Thus, the airspeed above the obstacle
would have been abou t 128 KI AS (13 I<IAS above the
stall warnin g stick-sh aker activation speed) and an
estimated p itch attitude of at least 13 d egrees would
have been required.
In the second case, it was calculated that if the
highest pitch a ttitude reach ed after lift-off had been
sustained, the a ircraft would have cleared the obstacle.
FDR data a nd pilot testimony indicated that pitch
a ttitude was reduced shortly after ta ke-off when a
d ro p in airspeed was noted . This probably occurred
about 15 feet above ground level. According to the
captain , the ini tial target pitch attitude was a bout 11
degrees. T he FDR data indicated that the airspeed was
d ecreasing th rou gh about 138 KI AS wh en the pitch
attitude was redu ced. I t was determ ined that, if the
aircraft had reached and maintained the 11 degree
pitch attitude, it wo uld have accelerated at an aver age
ra te of abo ut 2.6 kno ts per second. With a tailwind
increasing at 4.5 knots per second in accordance with
the d erived wind profile, the airspeed would h ave
bee n decreasing throu gh abo ut 125 KIAS at the poles
a nd the aircraft would have been at an a ltitude of
abou t 70 feet a bove ground level. In the aircr aft's
take-off config uration the stick-sha ker would h ave
ac tivate d at 115 KIAS a nd a stall wou ld have occu rred
at abou t 106 KIAS.
Significantly, th e calculations for these two cases
assumed that the wind effect on the a ircraft, d erived
fro m the FDR data , did not cha nge as altitude
increased. T here are several sch ools of thought
regard ing the wind velocities a t altitude in the vicinity
o f thunderstorms. The best evidence indicates tha t
vertical wind speeds associa ted with thunderstorm
dow n draft activi ty diminish rapidly below 300 feet a nd
that the d irection of move ment changes to a horizontal
outflow.
Becau se the captain began the ta ke-off with 1982
metres o f runway remaining rathe r tha n fro m the e nd
of the 2 134 metre runway, the investigation also
atte mpted to d etermine what effect the additional 152
me tres of runway would ha ve h ad o n the ability of the
aircraft to clear the obstacles. Since the wind mod el
d erived from the FDR data reflected the total wind
alo ng the flight profile actu ally flown by the aircraft, it
was not possible to d ete rmine precise ly what winds the
aircraft wou ld have e ncoun tered had it taxied to the
e nd of the ru nway and used all the available dista nce
fo r ta ke -off.
Assuming the wind d id not cha nge fro m the
FDR-derived model however, a take-off begun fro m
the e nd of the runway rather tha n fro m the d isplaced
threshold , would have resulted in li ft-off 664 metres
from the power lines, or 167 metres before the point
the aircraft actually lifted off. In this case, at a n
ave rage grou nd speed o f 138 knots, the elapsed time
fro m lift-off to the power lines wo uld h ave been about
9 .5 seconds. T he rate of climb requir ed to clear the 39
foot poles by 35 feet would have bee n abou t 467 feet
per minute and in the existing wind co nditions, the
air speed would have d ecreased to abou t 12 1 knots.
T h e stoppin g capability of the B727 was a lso
a nalysed to d ete rmi ne wh e n the ta ke-off could have
24 I Aviation Safety Digest 106
been rej ected and the a ircraft sto pped on th e
re ma ining runway. I n the wind conditions d erived
fro m the FDR d ata, it was estimated tha t the aircraft
cou ld h ave bee n stopped o n the ru nway if th e d ecision
to rej ect the take-off had been made with a t least 670
metres ofrunway remaining. (No allowance was m ad e
for reverse th rust or decision-making time). I n this
case , a decisio n to abando n the take-o ff a t V 1 (640
me tres remainin g) could have resulted in the aircraft
over-runnin g the e nd of the runway.
Take-off procedures
For normal take-offs, the airline's Boeing 727 Fligh t
Ma nual specified the following p roced ures:
'At VR, rotate the a irplane smoothly to the take-off
climb-out attitu de of approximately 13 d egrees. The
rate of rotation should be ap proximate ly two
degrees per second. Whe n the air plane is rotated at
the proper rate, lift-off will n or mally occu r before
reaching 10 d egrees of.pody angle , allowing rota tion
to be continued un til climb-out attitude is reached.
'Exce ssive rates of rotation must be avoided . If the
rate of rotation exceeds the proper ra te, it is possible
to reach an a ttitude t_hat will cause the tail skid to
contact the runway before the airplane can lift off.
'The a i:plane will no rmally attai n V 2 + 10 assu ming
all e ngines are operating, ap p roximately 35 feet
above the r u nway.'
After-take-off proced ures (climb to 1500 feet)
specified in the manu a l included :
' 1. T he airspeed indicator is primary for
establishi ng pitch a ttitude.'
T here was no thing in the ma nual wh ich provided
for adopting differe nt procedu res if var ia ble or gusty
surface winds existed or were su spected , or if low
a ltitude turbule nce or wind shear existed or was
reported to exist.
T he air line's wind shear training progra m co nsisted
o f a slide a nd tape presen ta tion , a simulator program
provid ing wind shear trai ning with emphasis o n
recognition for both landing and take-off, and
class-room lectu res a nd discussions on hazard ou s
weather which covered wind sh ear. T he program
also in cluded a comp re hensive d iscu ssion of wind
shear recogn ition factors associated with
thunde rstorm a n d cu m u lo-nimbus clo u ds. T h e
training records of each flight crew membe r sh owed
they had received this train ing .
In addition to the airline's for mal wind shear
training program the com pany pu blished
nu merous articles on hazardous weather cond itions
a nd wind shear in a fl igh t o perations publication,
copies of which were made available to each pilot.
Recognition factors such as virga and blowin g dust
were also contai'ned in these ar ticles.
Shortly before th e a ircraft took off, a dust storm
several hundred feet h igh originated to the south-west
of the airpor t a nd travelled rapidly across the a irport
in a northe rly direction. I t was accom p a nied by hig h
surface winds, var iable in direction, with g usts up to 50
kno ts. Based o n witnes·s obser vatio ns, recorded
weathe r data a nd the FDR-d erived wind model, the
Safety Boa rd conclu ded that th is storm was the gu st
fron t of a th understor m or group of convective clouds
which produced strong ver tical d owndrafts a n d strong
and varia ble horizontal winds at th e surface.
T he wind warning in e ffect at the time of the
accide nt called up strong gusty winds, b ut neither the
Tucson contro l tower personnel nor the flight cr ew
received this information . According to the weather
observer's testimo n y, a 24 m inute d e lay in ge tting the
informatio n to the use rs was caused by the rush of
events and o the r prior ities. Although National
Weathe r Ser vice procedures do not contai n a time
limit for hazardo us weather dissem inatio n , the Board
believed that such se vere weathe r infor mation should
be d isse min ated as soon as possible after it is d etecled if
it is to be effective. T h is warning would have he lped
alert the fligh t crew to a p ossible wind shear condition .
Avoid a nce of a wind shear e ncou nte r depend s on
timely alerts a nd the flight crew's early recognitio n of
p ossible wind shear condi tions. The Safety Board
believed tha t, d espite the abse nce of a specilic warning,
the captain had other clues which should have alerted
him to the possibility of wind shear :
• the tower re ported gusts u p to 50 knots a bou t. two
m inutes be fore the aircraft took off
• the winds shi fted rapidly, as much as 90 degrees
• a severe d ust storm crossed the approach end of th e
run wa y as the aircraft taxied to the r u nway fo r
take-o ff.
Whe n the aircra ft left the te rm inal, the captain
became awa re ofblowingdustapproach ingthe ai r port
from the sou th-west. Discu ssions recorded on the CVR
con firmed the crew were awa re of this. Wh ile taxiing
to R u nway 21 the ca p tai n received seve ral reports of
h igh wind s peed s a nd gusts. The variability of the wind
indicated ra p id movement or change, wh ich was
furthe r evid ence o f unstable conditions con ducive to
wind shear.
These recognition factors should have been pan of
the ca ptain's kno wled ge of th u nderstorms and
hazard ous weather phenome na. T he Safety Board
concluded that the airline's train ing program
provided sufficie n t wind shear information to the
captain fo r h is obser vations regarding the weather at
Tucson to have a lerted him to the possibilities of wind
shear. T hey sho u ld have deter red him from taking-off
under the cond itio ns, especia lly si nce the wind factor
was cri tical for the aircraft to re main withi n allowable
weight lim itatio ns for take-off on R unway 2 1.
T he wind model derived from FDR data showed
that the aircra ft ini tially encountered a strong
headwind at the sta rt of the take-off roll. This stron g
headwind d ecreased as the aircraft progressed down
the runway u ntil relatively calm wi nd was
e ncounte re d . T his calm was followed by a rapidly
increasing ta il wi nd. As the aircraft lifted off, it
e ncou ntered a stro ng crosswind from the right. Based
on the recorded a nd visua l evidence , the Board
concluded that the <;iircraft e ncou ntered severe wi nd
shear during th e take-off roll and d uring a critical
p hase of the depa rture.
The airline compa ny's Boeing 727 take-off
procedu res call fo r a smooth rotation to a pitch
attitud e of a ppro ximately 13 degrees and specify that,
a fter ta ke-off, a irs peed is the primary reference for
establish ing pitch attitud e. I n th is accident, the ca ptain
rotated the aircraft first to about 11 degrees a nd then
increased th e pitch a ttitu de when he realised th e
aircraft was not climbing. When he saw the air speed
d ec;ease and saw the power li nes, he lowered the nose
aga111 .
Aircr aft per formance analysis and other tests
showed that the aircraft could h ave cleared the poles
on ta ke-off if the captain h ad concentrated on fl ight
path control rather than airspeed loss in a take-off
situation where a irspeed was erratic. T he FDR showed
that the average rate of climb was 1 72 feet per min ute.
When the aircraft str uck the poles its a irspeed was
about 128 KIAS. The perfo r mance anal ysis showed
that maintaining an 11 degree pitch attitude after
lift-off wou ld resu lt in a rate ol"climb sufficient to clear
a 39 foot obstacle, though this wou ld have required the
pilot to allow the airspeed to decrease to about 125
kno ts.
While the aircraft possessed add itional aerodynamic
potential to counter the effects of the wind shear, the
increased potential existed in a regime of fligh t for
which the captain had no trai ni ng or approved
operating procedures. Based on the evide nce, the
Safety Board concluded that the captain could not
have been expected to oper ate the ai rcraft other than
in accor dance with prescribed compan y procedures.
Because the wind co nditions which affected the
aircraft could be deri ved only from data ge nerated
d uri ng the take-off, the Safety Board was unable lo
dete rm ine whether the captain's failure to use the full
le ngth of R u nway 21 contr ibuted to the accid e nt. A
few mi nu tes delay in take-off because the aircraft had
to be taxied lo the beginning of the runway might have
resulted in wind conditions that cou ld have been better
or worse than those actuall y experienced . But even
without considering the h azard s of wind shear, the
ca ptain's failu re to use all the available ru nway in a
situation where he need ed a 3.6 knot headwind
component to avoid an over weight lake-off reduced
the intended margin of safety.
T he recorded CVR conversations 'hang on gu ys'
and 'lost all our ai rspeed ' appear to reflecl recognition
of u nusual conditions. Wit hin about four seconds
however , the first officer called 'V 1 rotate.' T his would
have discouraged any thought about rejecting the
take-off at that time even if such an idea was ever
entertained.
While the performance anal ysis showed that the
aircraft cou ld have been stopped on the runway if the
take-off had been rejected before V" in itiation of the
take-off from the displaced th reshold rather than
fro m the end of the runwa)' substantially red uced the
re_cog:iition a nd decision time, and hence the margin
of salety, had any attempt been made to reject the
take-off from that point.
Probable cause
The National Transportation Safety Board
determined that the probable cause of the accide n l was
th e captain's decision to take off unde r evident
haza rd ous wind conditions which resulted in an
encou nte r with severe wind shear and subsequent
c~llision with obstacles in the take-off path. T he rate of
clim b of the aircraft in these conditions when flown
according to prescribed operating procedures was not
su fficient to clear the obstacles. H owever, if the
aircraft's full aerod ynamic capability had been used,
collision with obstacles probably could have been
avoided •
(Condensed from a report issued by the National Transportation
Safety Board, U.S.A.)
Aviation Safety Digest 106 I 25
�MD and the weather forecast
Murphy's Aeroplane Company is located at a private airstrip about 30 kilometres from a large regional
town. There is a government aerodrome near the town complete with a Flight Service Unit, several aircraft
operators and modern engineering shops; however, all the local aircraft owners know that Murphy does a
cheap 'hundred hourly' .
One of Murph y's cl ie nLs lived o n the far side of a hig h ma nip u lative ski lls ('Yo u couldn 't fly a kite, let alo ne a
mountain ra nge on the o pposite side o f Lown fro m
pla ne'), the local police ser gean t a r rived lookin g rathe r
Murp h y's strip a nd had ar ra nged to leave his
pa le a nd wor ried. He explained lhal he ha d bee n u p in
the ranges he lping at an aircraft accident which was
ae roplane one morn ing for Lhe 'extra specia l
guile a bit wo rse tha n MD's li u le escapad e, a nd that the
servici ng'. On the way down h e la nded a t the main
aerod ro me and called into the FSU to collect a co py o f investigators were tr ying to wor k outjust wh y
the local area fo recast. After arr iving a t Murph y's, the Murph y's client a nd his com panion had flo wn up one
or the blind valleys in cloud a nd straight in to a
clie nt explained that he was being picke d up by a
frie nd in a nother pla ne. T hey we re going to be flying mo un tainsid e.
all d ay a nd wo uld be ho me late, so the cl ie nt asked
Mu rph y and MD looked at each other and both
Murph y if he could have his aero plane delive red to his thoug h t Lhat p e rhaps the broken prop had been a
home as it was need ed fo r a n early sta rt the nex t
god send a h er a ll.
morn ing.
' Whoever takes iL u p can ride one of the bikes back to You may think the preced ing stor y is a bit far-fetched
bu t it reflects the details he ld in too man y accide nt
tow n a nd I'll get it later', said the clie nt.
'Okay, I'll get one o f the boys to d o tha t for you ',
records. In the years 1970- 1977 incl usive, the
following A ustralia n accident sLatistics were recorded:
re p lied Mur ph y. ' H ow was the weather on the way
d own ?'
Total accide nts (powe red aircra ft)
1687
' Bit of cloud on top o f the hills, but she'll be r ight', he Total fa tal accide nls
139
a nswered. 'See yo u later, Murp h'.
Total fa talities
346
'O kay, ma te'. T he other aircraft had a rrived a nd the Fata l accide nts with wea the r recorded as a factor 29
clie nt a nd his fr ie nd were soon on the ir way.
Fatalities in weather-rela ted accidents
98
It had been a ve r y busy d ay at Lhe wo rkshop - 'N o
T he 29 weathe r-related accid e nts being considered
time to repack those wheel bearings, MD ,' said
occurred during the clim b, cru ise and d escent p hases
Mu rph y Lo the Ma n in Lhe Dustcoat - and iLwas late a nd exclude take-off or landing accide nts. Closer
aflernoon wh en Murp hy told MD co return the newly study or the records reveals Lhe fo llowing:
ser viced a ircraft to the ow ner's property. Not wanting T·ype of accident
Lo d e lay the flig ht in case he was !ale fo r his usua l ' few Con trolled flighL into ground/water
13
at Lhe local', MD did not bo Lhe r pho ning the FSU to Unco ntrolled fl igh L into gro und/water
8
chec k Lhe wea ther or give any flig h t details. T he fact Collisions with trees
3
Lha t the sky was as black as the inside o f the proverbial Miscella neous
5
cow and the wind was blowing a near gale d id not
Phase of operation
Norm al cruise
wor ry him unduly. After all, iL was o n ly abo ut 20
16
minu tes n ying time to the custome r's Slrip if he slip ped Uncon trolled d escent
7
overthe to p of the h ills - it added abo ut 15 mi nutes to O n ap proach
6
Lhe fl ig lH to go around Lhe range a nd MD h ad heard a Kind offlying
23
few of the local p ilots tal king a bou t ' poki ng th rough Non-co mmercial p leasure
the cloud '. All he had to d o was climb 500 feet above C ha r ter - passenger operations
3
the hills a nd le t d own a few minu tes later to save all that Miscella neous
3
tim e.
In more tha n 75 per ce nt o f the fatal weathe r-related
Inside the coc kp it of the a ircraft MD fo und the
accidents a fo recast was obtained and was substantia lly
forecast which h ad acciden ta lly been left there by the correct.
owne r. H e was staring at it a nd scratch ing his head
T hese statistics relate only to fatal accide nts;
whe n a g ust o f wind blew the p iece o f paper away.
however, the re have bee n doze ns, even hund reds o f
' What the heck!', he thought, ' I cou ldn't unde rsta nd it occurrences over the years where piloLs became
a nyway'. Completely oblivious o f the su rrou ndi ng
involved unha p pily with Mother Nature.
weather a nd ig no r ing the rapidl y decreasing light, he
In many Digests we have cited fata l accidents where
go t into the cockpil and started up the engine.
the pilots were not under an y pressu re to u ndertake
The tailclragger was hard to taxi in Lhe stron g wind
the flig ht a nd whe re there was vir tua lly un limited
blowing across the sLrip, but eventua lly it reac hed the evide nce available to the m that a successfu l VFR flight
e nd and MD lined it up, in a fashion. No t wishing to was hig hly unlike ly. For some undetermined reason
d elay a ny fu n he r, MD opened the throttle and
they decided to ' have a go'.
almost immediately Lhe aircraft swung violently in to
It is obvious that some pilo ts do not und erstand the
wind , ran off the stri p a nd inlo on e o f the half 44's
weather a nd cannot re late forecasts to the ir pla nned
that Murph y used as strip markers. T h e woode n
fl ight. To tr y and a lleviate some of this proble m, a
prop sha ttered on the drum a nd the e ngine
series of a rticles o n 'm e teorology a nd the pilot' is be ing
vibrated to a stop. Comp letely bewild e red as to how prepared fo r inclusion in futu re Digests. Mea nwhile,
Lhis had a ll happened , MD left the cockpit and
readers are ad vised to stu dy the I 977 ed ition of the
walked dejectedly back to th e hangar.
Man ual of Meteorology, Part 2, Avia Lion Meteorology.
LaLer that night in the 'local', after Mu r ph y had
T his book is available fro m your nearest AGPS
clearly and lucidly told MD abo ut the deficiencies in h is bookshop•
26 I Aviation Safety Digest 106
----------"....
�Induction icing
~very yea~ t_he accident and incident records contain a significant number of occurrences in which
induction 1cm~ was considered t~ be the probable cause of an engine power loss. Although this
~henomenon 1s ~Y no '!'eans restricted to the approaching colder months of the year, it is an opportune
t1"!"e to ~~ce agam revise our knowledge of the circumstances leading to induction icing. To assist with
this rev1s1on we reprint the text of an advisory circular produced by the U.S. Federal Aviation
Administration.
Kinds of induction ice
compou nds the rate o f ice accretion with in and
immediately downstre a m fro m the ca rbure ttor.
It is important for a p ilot to know the kinds of
inductio n syste m icing and the ma nner in which each is
form ed . T he three kinds of icing are kno wn as impact Intake ice formation and prevention
Any one or a combinatio n o f the th ree kind s of
ice , fuel ice a nd throttle ice.
induction icing described above can cause a serious loss
Impact ice
of power by restricting the flow of the fuel/air m ixture
I ~n pact ice is fo rmed by the striking of moisture-lad e n to the e ngine and by inte r fe rence with the p roper
~1r at t~mperatures below freezing o n e le ments of the
fuel/air ratio. I t is usually p referable to use carburetto r
mducu o n system which are at tempe ratures of zero
heat or alterna te air as an ice p reventio n mea ns, rather
d egrees Celsius or below. U nder these con d itio ns ice tha n as a d e-icer, because fast-fo r m ing ice which is not
may build up on such compone nts as the air sco~ps, immedia tely recogni zed by the pilot may significa ntly
h eat or a ltern ate air valves, intake screens and
lower the amoun t of h eat available from the
protrusio ns in the carburettor. Pilo ts s ho uld be
carburettor heatin g system. Add itio nall y, to prevent
pa rticul~ rly ale rt fo r such icing whe n fl ying in snow, power loss from im pact ice, it may be necessa ry to turn
sleet, ra m, o r clouds, especially when they see ice
to carbure ttor heat or alternate a ir before the selector
f~rmin g o n the .windshield or leading ed ge o f the
valve is frozen fast by the accu mulation o r ice arou nd
w111 gs. The a mbie nt te mperature a t wh ich impac t ice it. Whe n icing conditions are present, it is wise to g-u ard
can be ex pected to build most rapidly is abou t minus again st a serious build-u p before de-icing capability is
fi ve d egrees Celsius when the supercoo led moisture in lost. The use of partial heat for ice preve ntio n without
the a ir is still in a semi-liquid state. This type of icin g some instrume ntation to gauge its effect may be worse
affects an e ngine with fuel injection, as well as
tha n n one at all u nd er the circumstances. I nduction
carbure ttor e ngines.
icin g is unlikely un der extre mely cold conditions,
because the relative h u mid ity is usually low in cold air,
Fue l ice
a
nd because su ch moisture as is present usuall y
Fue l ice forms a t a nd downstream fro m the point
co nsists of ice cr ysta ls which pass thro ugh the system
whe re fu el is mi xed with the incoming a ir, if the
harmlessly. T he use of p artia l hear when the
e ntrained mo isture in the air reaches a freezing
temperature
is below zero degrees Celsius may, for
te m perature as the resul t o f the cooling o f the mixture
example,
ra
ise
the mixtu1·e tem peratu re up to the
by the va po risatio n of the fuel. Moisture may the n be
precipi ta te d fro m the incoming air and de posited o n d anger range , whereas fu ll carbu rettor hea t would
the walls of the induction passages as condensation . bring it well above any d anger o r icing.
Whe n the te mperature is sufficie ntly reduced, this
Excessive use of c arburettor heat
conde nsa tion acc umu lates as ice , especially on
Whe n no carburetto r air or m ixtu re temperature
irre gula rities of the ind uction system, such as elbows
a nd j oints. I f th is bui ld-up is allowed to co ntinue, the instrume nt~tion is available, the ge neral practice with
ice may build up until it effectively th rottles the e n g·ine. smaller engmes s ho uld be to use fu ll heat whenever
car~urettor heat is a p plied . Wi th h igher output
Visible moisture in the a ir is not necessary for fu el
e n gn~es! howev~r, especia lly those with su perchar gers,
icii:g, some times i:r1aking it difficult for the pi lot to
be lieve, unless he 1s fu lly aware of the fuel icing effect. d1scnm111at10n 111 the use of heat sho uld be exercised
Fuel icing is n o~ a problem in .systems which inject because of the possible engine overh eati n g and
the fu el at a locauo n beyond which the passages are detonatio n hazard involved. A pilot o f an aircraft
kept warm by e ngi ne heat. T hus, the injection of fuel equip ped with a carburettor a ir or mixtu re
temperature gauge sho uld make it a practice to
directl y into each cylinder, 01· into a ir heated by a
regulate his carburetto r heat by reference to th is
~~percharge r, will proba bly preclude such icing. Fuel
indicator.
In a ny aircr aft, the excessive use of heat fo r
1c111!? may occur a t tempera~ures from zero degrees to
full power operatio ns, such as take-offs or emergency
as hig h as 40 d egrees Celsius, and wit h a relative
go-arounds, may .result in a serio us red uction in the
humidity of 50 per cent or above.
power developed , as well as the haza rd o f en gine
Throttle ice
damage. It sh o uld be noted that carbu rettor heat is
T hrottle ice is formed at or near a partia ll y closed
rarely needed fo r brie f h igh power operatio ns.
throttle, typ ical o fa cruising powe r setting. This occurs
whe n wa ter va pour in the air condenses a nd freezes Indications of induction icing
because o f the cooling cau sed by th e expansion of the The .rossibility of induction icing shou ld always be
mixture as it passes downstream from the restriction considered when the temperatu re is between ze ro and
caused by the throttle and the carburettor ventu r i. In
plus 20 degrees Celsius, with a re lative hum idity
conve ntional float-type carburettors, throttle icing
greater tha n 50 per cent, or whe n the tem pera tu re is
u sually occurs in combination with fuel icing, which
below freezing with visible moistu re in the air. The
28 I Aviation Safety Digest 106
FUEL
-
THROT T LE
BUTTERFLY
-
-
-
effect of induction icing is a gradual, progressive
decline in the powe r delivered by the engine. Wi th a
fi xed pitch p ro peller th is is evidenced by a loss in
e ngi ne rpm a nd a loss of altitude or airspeed unless
the th rottle is slowly adva nced . With a constant speed
propeller, t here will normally be no change in rpm
but the same d ecrease in aircraft perfor mance will
occur. With a ma nifold pressure gauge, a decrease in
ma nifold pressure will be noted before an y significant
decrease in e n gine rpm or aircraft performance. With
an exhaust gas tem perature indicator, a decrease in
exhau st gas tem perature will occur before any
noticeable decrease in engine and aircraft
performance. If these indications are not noted by the
pilot and no corrective action is taken, the decline in
engine power will p robably continue progressively
until it becomes necessary to retrim to maintain
altitude; and engine roughness will occur probably
fo llowed by backfiring. Beyond this stage, insufficient
power may be available to maintain flight; and
com plete sto ppage may occur, especially ifthe throttle
is moved a bruptly.
Preventive actions
T o preven t accid ents resu lting from intake icing, the
pilot should regularl y use car burettor heat under
conditio ns known to be conducive to icing and be alert
at a ll times fo r ind ications of icing in the induction
system. The follow ing precautions and procedures will
te nd to redu ce the likelihood of intake icing problems:
- Pe riodically check the carburettor heat systems and
controls fo r proper condition and operation.
- Star t the e ngine with the carburettor heat control in
the COLD position to avoid possible damage to the
system a nd a fire hazard because or a backfire while
star ting.
- As a pre-flight item , ch eck the carburettor heat
effective ness by noting the power drop (w hen heat
is ap p lied ) on run-up.
- Whe n the re lative h umidity is above 50 per cent and
the tempe ratu re is below 20 degrees Celsius, apply
car burettor heat briefly immediately before
take-o ff to r e move any ice wh ich may ha ve been
accu m ulated durin g taxi a nd run-up. Generally,
the use of carbure ttor heat for taxiing is not
-
-
-
recommended because of possible ingestion of
foreign matter with the unfiltered air admitted with
the control in the HOT or ALTERNATE AIR
position .
Conduct take-off without carburettor heat, un less
extreme intake icing conditions are pre~ent.
Remain alert for indications of induction system
icing during take-off and climb-out, especially
when the 1·elative humidity is above 50 per cent, or
when visible moisture is present in the atmosphere.
With instrumentation such as carburettor or
mixture temperature gauges, partial heat should be
used to keep the intake temperature in a safe range.
Without such instrumentation, full heat shou ld be
used interm ittently as considered necessar y.
If indu ction system ice is suspected of causing a
power loss, apply full heat or alternate air. Do not
disturb the throttle until improvement is noted.
Ex pect a further powe1· loss momentarily and then a
r ise in power as the ice is melted.
If the ice persists after a period with full heat,
gradually advance the throttle to full power and
climb at the maximum rate available to produce as
much heat as possible. Leaning with the mix tu re
control will generally increase the heat but should
be used with caution as it may stop the engine u nder
circumstances in which a re-start is impossible.
Avoid cloud s as much as possible.
As a last resort, a severely iced engine may
sometimes be relieved by inducing backfiring wi th
the mi.xture control. This is a critical procedure at
best, should not be attempted with superchar ged
engines, and must be done with the carbur ettor heat
control in the COL D position.
Heat should be applied for a short time to warm the
induction system before beginning a prolonged
descent with the engine throttled and left on during
the descent. The pilot should be prepared to tu rn
the heat off after power is regained to resume level
flight or initiate a go-around from an abandoned
approach.
T he pilot should remember that intake icing is
possible with temperatures as high as 40 degrees
Celsius and the humidity as low as 50 per ce nt. It is
most likely, howeve r, with temperatures below 20
degr ees Celsius and the relative hu midity above 80
per cent. The likelihood of icing increases as the
temperature decreases (down to zero degrees
Celsius) and as the re lative humidity increases.
The effects and recommendations described in this
circular are general in nature and appropriate to
most certificated aircraft. The pilot should refer to
all available operating instructions and placards
pertaining to his aircraft to determine whether any
special considerations or procedures apply to its
operation.
Having discussed the formation of the various kinds
of induction icing, let u s now look at an unusual
aspect of one particular kind of icing.
T he U.S. National T ransportation Safety Boar d
recently investigated the crash of an Aero Commander
560E which h ad been fl ying at 11 OOO fee t when the
pilot reported he could no longer maintain altitud e
because of a power loss from both engines. The
aircraft was subsequently being radar vectored to a
Aviation Safety Digest 106 I 29
�nearby aerodro m·e when it crashed into a reside ntial
a rea. The first people to arri ve at the accident site
noticed that both ra m a ir tubes and the carburettor
mixin g cha mbe rs were packed with ice.
This aircra ft was fitted with injection-type, single
barre l, low pressure carbu rettors in wh ich the fue l is
introduced d ownstream from the throttle and beyo nd
the ve nturi cha mber. This d esign feature virtually
e liminates fuel (vapour) ice a nd reduces the haza rd of
throttle ice in the induction syste m . The third kind of
icing - im pact ice - still p resents a proble m a nd may
fo r m in the carbure ttor a ir inlet ducts, the scree n, the
elbow, the mete ring e le me nts a nd the hea t va lve.
Because o f the favo urable cha racte ristics of aircra ft
fitted with this ty pe of ind uctio n system , pilots ma y no t
recognise that impact ice still poses a potentia l hazard
for the ir aircra ft. U ndue delay in selecting alternate a ir
in some icin g conditions may result in an ice
accu m ulation which immobilises the heat valves. Once
th is has happe ned , the pilot may be powe rless to
coun te r fu rthe r ice build-u p and the engines ma y
subseq uently lose all power.
Throughout this article re ference has been made to
induction icing, not the more common terminology
of carburettor icing. The reason for this is to dispel
the misbelief that fuel-injected e ngines are not
susceptible to the formation of induction icing.
Although the development of injection-type
carburettore d engines and fuel-injected engines has
greatly re lieved the problem it still exists,
particularly in conditions of visible precipitation.
You are strongly advised to carefully study the
Owner' s Handbook or Pilot's Manual for the aircraft
you fly. Be sure that you know the type of induction
system fitted to the airc raft and the correct means
available for preventing or overcoming the problem
of induction icing •
Rudder pedals
The following two accounts show how the links In the chain of events which can lead to an accident are so
easily formed .
.
I n the first o f these, a contr ibution from a reader , one
of the lin ks in the chain fortun ate ly did not d evelo p:
' I a m the C hief Flying Instructor o f a fl ying school
a nd have nearly 10 OOOhours piloting e xperience with
a bo u t 6000 instructional ho u rs, mostly on
single-e n gine aircraft. I n the last 12 mo n ths I have
received ap proval to con d uct twin-engine
e ndorse me nt training, including the certification of
initial endorseme nts.
'My normal procedu re during pre-take-off checks is
to read the check list while the trainee com pletes the
checks and res po nds. On completion of the checklist
the trainee provid es a ta ke-off briefin g includin g
re fe re nce to e merge ncy d rills. Finally we d ecid e who
will control the a ircraft in the event of an actual engine
failu re; th is is no rmally myself.
' On one particular flight, in a Beech B55 Baron, the
normal p rocedu res were conducted and the ta ke-o ff
comple ted withou t incide nt. After reaching the
tra in in g area, I took over control o f the a ircraft from
the tra inee to demonstrate a procedure a nd was
su r p rised to find that my right rud d er ped a l was still
stowed against the floor.
'Needless to say, had the le ft e ngine failed on
ta ke-off, a nd the tra inee re linquished control to me as
we had briefed , an accident would have probably been
unavoidable. The only explanation I can offer is that I
simply had not thought about checkin g my rud der
pedals fo r o pe ra tion pr ior to ta ke-o ff.'
T he message in this occurre nce is that in a two pilot
o pe ra tion , both p ilots sho u ld e nsure fu ll and free
mo ve me nt of the controls before take-off. In this way
the formatio n of a nother link in that inevita ble chain
can be averted.
In th e second instance, the aircraft involved, a Piper
Paw nee modified fo r side by side seating with dua l
controls, was being fe rried to a n agricultu ral airstrip.
The pilot, who was fl yi ng alone, planned to inspect the
strip from the a ir before la nd in g and , about a
kilo metre fro m his destination, he began a ge ntle righ t
turn to line up for his inspectio n run. At that stage, the
aircraft was fl ying at a bout 200 feet AGL and 85 knots,
with the e n gine set at cru ise power.
As soon as the p ilot went to turn right, the
aircraft yawed to the left. In an effort to cou nte ract
the turn, the pilot a pplied more r igh t aileron a nd
right rudder, but this onl y caused the flat turn to
tig hte n. Skidd ing left th ro ugh abou t 120 d egrees,
the a ircraft lost height until, at abo ut l 00 feet, it
began to bu ffet, the nose dropped a nd the a ircraft
descend ed rapidly with the wings level un til it
struck the ground. The la nding gear collapsed a nd,
as the aircraft skid ded along the gro und , it rotated
even further to the le ft. The pilot escaped with
mino r c uts a nd br uises.
T he a ircraft was a special dual-traini n g ve rsion of the
Paw n ee with rathe r restricted sid e by side seating. I t
was equ ipped with two sets of rudd er pedals bu t
measurements showed that the d ista nce between the
cen tres of the left a nd righ t pedals on the left set o f
controls was o nly 28 centimetres, while in the normal
Pawn ee, with o nly o ne set of controls, this d istance is
49 .5 centimetres. T he space between the two sets of
ped als in the two-seat aircraft, edge to edge, was o nly
three centimetres. T h ere we re no obstructions
between those sets.
Altho ugh the pilot had flown abo ut l 400 ho urs in
the n ormal, single-control Paw nee in the two years
~:fore th e acciden t, ?e had flown only eight hours in
e du~-~ontrol version over the same period He did
not pos1t1vely recall having shifted his feet off th
rud_der pe_d~ls in fl ight and then shuffled the m b:ck
agam but It is possible that, had he done so, his ri ht
foo t could_ well have taken u p a more natural osirfon
on the a?Jace n t left pedal of the right side s~t
hT h e pil.?t reme n:bered that on an earlier occ~sion
w. e n .taxun g the aircraft, he had momentaril lost '
d1re~t1onal con trol and he concluded at the ti~e he
ha~ ilnad verten tly placed his right foot on the wrong
pe a . In the a bsence of any other explanation for the
•
.a
loss
which
. .
f
h ' of control
·
. led to this accide nt ,an d mv1ewo
his previous experien~e, the pilot thought it likely he
ad done the same thmg on this occasion.
Dual rudder control installations of this type are not
~ommo.n, and obviously, in such a confined cock it it
is ve.ry impor~ant that contro ls be protected as fa; as
~oss1ble from mterference and inadverten t operation
s a result o~ the a~ci dent to the Pawnee, the
.
Depa.rtn:ent is considering the desirability and
pr~ct1ca~1ty of some form of shielding or other means
~f l~olatmg the two sets of rudder pedals in this and
similarly modified aircraft e
(continued from page 21)
• Act as soon . as
..
. you see
. the fi rst 'roo · Th e cl ec1s10n
m ust b e pos1t1ve and immediate you ma
h
ti m t
b
.
y not ave
e_ o act y the time you see the second one
Durin g the landing phase the de . .
.
.
b
.
.
CISIOn IS easy a ort. If the s1tuat1on occu rs d u ring take-off yo
can o~ly d o what seems best at the time. I n my' ow~
expe ~1e nce, I have been surprised atju st how well
m~ a ircraft per forms with full power, high nose
a.t titude an d ver y low speed . B u t no two
c~rcum sta nces a re ever the same so I must repeat
t at Y?u ca n o nly do what seems best at th e time.
Kn.owm g your airc raft will be of invaluable
assista nce .
. 'So tha t is my two cents worth - it b ·1 d
airma nshi I
b
o1 s own to
ab
M p suppose, ecause that is what safety is all
ou t. y own rules for prevention?
: ~on_'~ oh erate . in known 'roo territory at night.
•
voi t e period s of peak activity.
O n app roach try to match a slightly nosedown
I
I
I
I
1'
at~itu~e with .the slowest possible forward speed as
this -:v1~l provide a good field of vision while also
p rov1dmg a. safer starting point to initiate a
go-aro u nd 1f necessary.
• Act imme?iately ~pan sighti ng a kangaroo for your
b~st margm of safety. During your take-off run, this
m.a y be yo~r only chance to safely abort the take-off.
• If you dec1~e. that a safe landing is possible, aim for
the ve r y m1111mum of ground roll that will not
destroy the brakes.
• And re member, it is not the first 'roo that will hurt
, _rou, but the others following it.
Fm ally a word of cau tion : on your fi rst few
enco?nte~s it w~ll be difficult not to over-react to
the s1tuah? n. Bitter experien ce has s hown me that
over-reaction can magnify this, or any situation
?ut of a ll proportion. So the message here is - if
m doubt - don 't d o it!' e
30 I Aviation Safety Digest 106
Avi~tion Safety Digest 106 I 3 1
I
I
�
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Transport - Australia
...
105/1979
�Contents
Oxygen and the pilot
More and more light aircraft these days are coming equipped with turbochargers, pressurization and
the performance to fly up where the angels sing. As general aviation develops, more pilots are being
trained to operate machines capable of high altitude flight. There is a lot to learn about this kind of
flying and a good starting point is the reaction of the human body to flight above 10 OOO feet.
3
Oxygen and the pilot
7
Use all the strip length - and keep to the
centre
8
A chance in a million -
9
Editorial - acrobatics and structural
limitations
a pilot contribution
1O
One down and one to go - the facts about
engine failure in a light twin
15
From one of our readers - a valid message
from the past
16
Recurring fault leads to fatal ditching
18
Lack of knowledge can cause accidents
20
Systems knowledge - the electrical system
26
Low cloud and rain - why 'have a go?'
28
Search and rescue, part 5
Aviation Safety Digest is prepared in the Air Safety Investigation
Branch and published for the Department of Transport through the
Australian Government Publishing Service. in pursuance of Regulation 283 of the Air Navigation Regulations. It is distributed by the
Department of Transport free of charge to Australian licence holders
(except student pilots), registered aircraft owners, and certain other
persons and organisations having a vested operational interest in
Australian civil aviation.
Aviation Safety Digest is also available on subscription from the
Australian Government Publishing SeNice. Enquiries should be
addressed to the Assistant Director (Sales and Distribution),
Australian Government Publishing Service, P.O. Box 84, Canberra,
ACT 2600. Subscrip tions may also be lodged with AGPS Bookshops
in all capital cities.
Change of address:
Readers on the free distribution list should notify the Department of
Transport, P.O. Box 18390, Melbourne, Victoria 3001.
Subscribers should contact the Australian Government Publishing
Service.
©Commonwealth of Australia 1979. The contents of this publication
may not be reproduced in whole or in part, without the written
authority of the Department of Transport. Where material is indicated
to be extracted from or based on another publication, the authority of
the originator should be sought. The views expressed by persons or
bodies in articles reproduced in the Aviation Safety Digest from other
sources are not necessarily those of the Department.
Reader contributions and correspondence on articles should be
addressed to:
The Editor (Harvey R. Ritchie),
Aviation Safety Digest,
Department of Transport,
P.O. Box 18390. Melbourne, Victoria 3001 .
RM77/30217(1) Cat. No. 78 9331 3
Covers
Scenes in the maintenance workshop of a domestic airline.
Front
A maintenance engineer and an airworthiness surveyor inspect the
wheel well of a DC-9 aircraft.
Back
Major overhaul of a DC-9.
2 I Aviation Safety Digest 105
Printed by Ramsay Ware Stockland, 552-566 Vic toria Street, North
Melbourne, Victoria.
Note: Metric units are used except for airspeed and wind speed
which are given in knots; and for elevation, height and altitude where
measurements are given in feet.
c
Air pressure
About 175 years ago scientists first d iscovered that
the prime purpose of breathing was to obtain
oxyge n needed by th e body a nd to get rid of excess
carbon d ioxide, a waste product.
T he h uma n body is a heat engine which, like any
e n gine, consumes fuel (the carbohydrates, fats and
p roteins derived from food). This fuel is converted
into the energy we need to live by a burning
process called oxidation. As in any other burning
process, a certain amount of oxygen is necessary.
When the body is resting, it consumes
approximately 0.3 litres of oxygen per minute.
When given an added workload such as walkin g or
running, the body, like a n y other machine, will
genera te mo re h eat and u se more oxygen, perhaps
as m uch as fi ve litres per minute.
To extract this oxygen from the a ir, the body is
equipped with a respiratory system (lu ngs). The
oxygen is then distributed through the bod y by a
circulatory system (heart, arteries and capillaries).
Air contains about 20 per cent oxygen a nd about
80 per cent nitrogen. At sea level, a healthy man
can extract enou gh oxygen from the a ir to m aintain
his system and continue his n ormal activities. About
8000 or 9000 feet, however, problems of oxygen
sh ortage begin to appear. Because th e a ir is less
dense, it offers less actual oxygen per breath of air
inhaled - even though oxygen and nitrogen are
still mi xed in th e 20:80 ratio. The density of air is
measured by barometric p ressu re, and it is on this
principle that your altimeter is built.
Oxygen is carried in the blood as a sii.nple
physical solution , and in loose chemical combination
with the haemoglobin of the red cells in the form of
oxyhaemoglobin. As the result of inhalation of air
into the lu ngs, blood is oxygenated and this oxygen
is carried to all the tissu es of th e body. Carbon
dioxide produced in the tissu es is carried in the
blood, in ch emical combination a nd in simple
p hysical solution to the lu ngs where it is exhaled.
Blood can be compa red to a conveyor belt,
constantly h auling oxygen in and carbon dioxide
out. The a mou nt of oxygen that can be car r ied in
the blood d epends, to a large extent, upon the
pressure th at the oxygen gas in the air exerts on the
blood as it p asses through the lungs.
(Ma nufacturers of carbonated d r inks take
advan ta ge of this pressure principle to d issolve
la rge <J,mounts of carbon dioxide gas in their
beverages).
At 10 OOO fee t, the blood of a man who is
exp osed to ou tsid e a ir can still carry oxygen at 90
per cent o f its capacity. At this altitude, the fligh t
performance o f a h ealth y pilot is impaired only
a fler some time, when he ma y find himself a little
less dexterous than u sual a t tuning r adios, slower at
worki ng navigational problems, and less able to
sustain close con centration. At 14 000 fee t, he may
become appreciably h a ndicapp ed - for getting to
switch tanks, flying off course, or disregarding
hazardou s situ ations . At 18 OOO feet and beyond,
exposure to environmen tal air will quickly cau se
total collapse and inability to control th e aircraft.
This means that if you choose to fl y at high
altitudes, you must take along either oxygen or
p ressure. You have a choice, the n , between
pressurizing the cabin of the aircraft or breathing a
mixture with more oxygen in it.
Aviation Safety Digest 105 I 3
�.
Hypoxia
Lack of oxygen is the greatest single d anger to man
at high alti tudes, d espite the importance of pressure
and temperatures. T he sh ortage of oxygen in the
human body r esults in a condition called h ypoxia,
which simply means failure of the tissues to receive
a su fficien t supply of oxygen. Whe n a pilot inhales
air at high altitudes, there is not e nough oxygen
pressure to force adequate am ounts of this vital gas
through the membranes of the lungs into the blood
stream , so tha t it can be carried to the tissu es o f the
body. The function of various orga ns, including the
brain, is the n impaired.
Unfortunately, the nature of h ypoxia makes yo u,
the pilot, the poorest judge of when you are its
victim. The first symptoms of oxygen deficiency are
misleadingly pleasa nt, resembling mild in toxication
from alcohol. Because oxygen starvation strikes first
at the brain , your higher faculties ar e dulled. Your
normal self-critical ability is out o f order. Your
mind no longer functions properl y; your ha nds and
feet becom e clumsy without you being aware of it;
you may feel drowsy, languid, and nonchalant; you
have a false sense of security; and, the last thing in
the world you think you need is oxygen .
As the hypoxia gets worse, you may become dizzy
or feel a tingling of the skin. You might have a dull
head ache, but you ar e only half aware of it. Oxygen
sta rvation gets wor se the lon ger you remai n at a
given altitude, or if you climb h igher , your heart
races, you r lips, cars and the skin und er your
fingernails begin to tu rn blue, you r field of vision
narrows and the instrume nts start to look fuzzy. But
hypoxia - b y its nature a grim d eceiver - makes
you feel confident that you are d oing a better j ob of
fl ying than you have ever done before. You are in
about the same condition as the fellow who insists
on driving his car home from a New Year 's Eve
party whe n h e can hardly walk . Regardless of his
acclimatization , endurance, or othe r attributes,
every pilot will suffer the conseque nces o f h ypoxia
whe n he is exposed to inadequate oxygen pressure.
What d o you d o about it? Ther e is o ne gene ral
rule: Do not let hypoxia get a foot in the door.
Carry oxygen and use it before you start to become
h ypoxic. Do not gauge your 'oxygen hunger' by
how you feel. Gauge it by the altimeter.
H e re are some general suggestions which apply to
young, healthy flyers.
1. Carry oxygen in your aircraft or do not fly
a bove 10 OOO feet. If bad weather lies ahead ,
go around it if you cannot get over it.
2. Use oxygen on every flight a bove 10 OOO
feet. You will probably need it, and whe n
yo u d o, you might not realise it.
3. Use oxygen on protracted fli gh ts near
18 OOO ft
14 OOO ft
10 OOO ft
Breathing problems?
Condition
Hypoxia
Fear o·r
anxiety
(recognised fear)
followed by
Hyperventilation
4 I Aviation Safety Digest 105
-
10 OOO feet. It will no t hu r t you and you will
be a lot sh arper pilot.
4. As the r etina of the eye is the most sensitive
tissue in the bod y to lack of oxygen, use
oxygen o n all night fli ghts a bove 4000 feet.
If you want to give you r night vision the
best p rotection , use oxygen from the ground
up.
5. Breathe norm ally when using oxygen. Rapid
or extra-deep breathing can ca use loss of
consciousness also.
Flying a bove 10 OOO feel witho ut using oxygen is
like playing Russian roulette - the odds are that
you may not get hurt, but it is a d eadly game !
Above 18 OOO feet your vision rapidly deteriorates
to the point that seeing is almost impossible. The
engine sounds becom e imperceptible, breathing is
labored , and the h eart beats rapidly. You h ave not
the vaguest idea what is wrong, or whether
anything is wrong. At 25 OOO feet you will collapse
and death is immine nt unless oxygen is restored.
I ndividual response to h ypoxia is so varied that
no o ne can predict the exte n t of oxygen d epletion
need ed to bring on the onset of symptoms - or
which symptoms will pred ominate with a ny given
individual. One per son will suffer from headaches,
another from dizziness, and another from e uphoria
under exactly the same conditions.
Recognise and cope
Common symptoms
Cabin altitude
Exposure time
Conditions
Visual disturbances
Lightheadedness,
dizziness
Confused thinking
Cyanosis
Apprehension
Sense of well being
Muscular inco-ordination
and tingling
Rare below 1O OOO feet
Indefinite
Oxygen generally not used
About 30
minutes
No oxygen used, or
significant leak in system
Five minutes to
12-15 seconds
Leak in oxygen system or loss
of mask after decompression
Less than one
minute
With pressure breathing
. equipment only
Uneasy sensation
Tenseness
Lightheadedness,
dizziness
Visual disturbances
Fatigue
Tremors
Lightheadedness,
dizziness
Tingling
Visual disturbances
Tremors
Confused thinking,
faintness
Numbness
..J!---!
Expected between
10-15 OOO feet
Causes collapse above
18 OOO feet
(
__§·:)
Always above 50 OOO feet
without pressure suit.
.
Any altitude
Constant or
precipitated by
unusual situations
within seconds
Under any condition
'
Any altitude
Within seconds
UnderanycondWon, b~mo~
likely when pressure breathing.
Corrective action
100% OXYGEN and
EMERGENCY
REGULATOR SETIING
Descend to safer
altitude
Recognition of
problem ,
then
Breathing Control
If in doubt, take
one deep breath of
100% oxygen, hold
breath for 1O
seconds, and breathe
slower.
Aviation Safety Digest 105 I 5
�•
••
Pilo ts who ar e older, fatter , out of condition or
h eavy smo kers sh ould limit themselves to a ceiling
o f 8000 to 10 OOO feet unless oxygen is available.
Smoking reduces tolera nce to al titude because
carbon monoxide from tobacco smoke combines
with haemoglobin in preference to oxygen. T hus
less haemoglobin is available for oxygen a nd a
combina tion o f carbon monoxid e a nd increase in
altitude can result in h ypoxia at lower altitudes.
Remember no one is exempt from the effects of
h ypoxia. Everyone needs a n ad equate suppl y of
oxygen . Some pilots m ay be able to tolerate a few
thousand feet more altitude tha n o the rs, but no one
is really very far from average .
Hyperventilation
Some people believe that breathing fas ter and
d eeper at high altitudes ca n compensate for oxygen
lack. This is only partially true. Such abnormal
breathing, known as h yperventilation, also causes
you to flush from your lungs much of the carbon
dioxide your system needs to main tain the p roper
d egree of blood acidity. The ch emical imbalance in
the bod y then produces dizziness, tingling o f the
fingers a nd toes, sensation of b od y h eat, rapid heart
ra te, blurring of vision , muscle spas m a nd, finally,
unconsciousness. The symptoms resemble the
effects of h ypoxia a nd the brain becom es equally
impaired.
You ar e most likely to hyperventilate while flying
under stress or at high altitude. For example, the
stressful feeling of unexpectedly e nte ring
instrume nt conditions, no ting both fu el ga uges
bouncing on e mpty, or d eveloping a rough-runni ng
engine over water or mountainous terrain may
ma ke you unconsciously breathe m ore rapid ly or
more d eeply tha n necessary.
6 I Aviation Safety Digest 105
A pilot wh o su ffers an unexpected attack of
hyper ventilation, and has no knowled ge of wh at it is
or wh a t causes it, may become terrified thi nking
that he is experiencing a heart a ttack, carbon
monoxide poisoni ng or somethi ng equally o minous .
In the resulting pa nic and conf usion , h e may lose
control of the aircraft, exceed its structural limits
a nd crash .
A little knowledge is all you n eed to avoid
hyperventilation p roblems. Since the word itself
means excessive ve ntilation of the lungs, the
solution lies in r estoring respiration to normal.
First, however, be sure that h yperve ntilation , a nd
n ot hypoxia, is at the roo t of your sympLOms. If
oxygen is in use, check the equipm en t a nd flo w
ra te. T hen , if e ve r ything appears normal, make a
strong conscious effort to slow d own the ra te and
decrease the d epth of your breathing. Talking,
singing or coun tin g aloud often helps. Normally
paced conversation te nds to slow dow n a rapid
respirator y rate. If you have no one with you tal k to
you rself. Nobod y will ever know.
Use all the strip length keep to the centre
and
A Britten Norman Islander, operating a regular public transport service departing from and
terminating at Lae, Papua New Guinea, was scheduled to land at several highland airstrips en route.
Outbound from Lae, the flight progressed normally and after landing at the second of the strips, the
pilot taxied the aircraft to the parking bay 50 metres from the south eastern end and shut down the
engines.
0
N ormal breathing is the cure fo r hype rventilation.
T he body must be allowed to restor e th e proper
carbon dioxide level, after which recovery is rapid .
Better yet, take p reve ntative measu res. Know and
believe that overbreathing can cause you to become
disabled by h yperventilation .
The best way to recognise the sym ptoms and
understand the effects of h ypoxia is to experience it
under con trolled conditions. T his is possible in a
d ecompression ch a mbe r a nd the Royal Australian
Air Force h as four such chambers located at
Ambe rley, Qld. ; Richmond , NS W; Point Cook, Vic;
a nd Pea rce, WA. At present arra ngem ents exist for
interested organisations to undergo on e d ay
training courses in h ypoxia a nd disorientation , in
groups of 15-20 people. E nquiries concerning the
courses should be directed in writing to the Director
of Aviation Medicine , Department of Transport,
P.O . Box 1839Q, Melbourne.
A future a rticle in the Digest will d eal with
oxygen equipme nt in use a nd discu ss its proper
care and correct o peration •
T his pa rticular airstrip is on a wide sloping sh elf on
the side of a mountain a nd head s di rectl y up the
slope. The a pproach to the strip is clear of
obstructions. T he average g radie n t alo ng the strip is
seven per cent, consequ entl y onl y one-way
ope ra tions a re possible. T he ce ntral 10 metres of
the strip width consists of crush ed coral a nd
limeston e and has a hard ,-sparsely grassed surface,
bu t over the 10 metres either sid e of th is central
area the grass is to ugh and d ense. From the no rth
western threshold th e grou n d falls away steeply to
the valley floor 3000 feet below.
With three passengers o n board , th e p ilot started
the e ng ines fo r departu re. H e did not taxi out to
the centre line of the strip , nor d id he ta ke
ad vantage of th e extra 50 me tres of usable strip
above the pa rkin g bay. Instead , he ca rried out his
pre-ta ke-off \ becks in the par kin g bay and the n
taxied as f'a r as the righ t ha nd side of' th e strip.
Witho ut stopping, he began the ta ke-off run
through th ick grass n ear the right hand ed ge of th e
marked area.
About a th ird o f the way alo ng the strip, th e
down grade increases markedly a nd , upo n reachi ng
this point, the pilot mome ntarily consid ered
a bandoning the take-o ff. Up to this stage
acceleration h ad bee n poor but the a irspeed was
increasing so he decided to continue. Acceleration
remained poor however and , even though the pilot
felt that the wheel bra kes were d ragging, he was
now committed to ta ke-off. T he aircrnft was rota ted
and the nose wh eel left the ground about 20 metres
from the end of the stri p. T h e m ain wh eels
remained fi rm ly on the ground and , as the ai rcraft
over-ran th e strip, the wheels struck a shallow ditch
and a 40 cm high earth embankme nt across the
end. T he impact forced the right main landing gear
leg rearwa rds to a n a ng le of a bou t 45 degrees and
catapulted the aircra ft in to th e air.
Barely maintai ni ng n ying speed , the aircra ft fl ew
th rough the to ps of trees level with , a nd 60 m etres
beyond, th e e nd of th e strip. I m pact with the tree
tops d ented the leading ed ge o f' the rig ht wing but
the aircra f't continued in fligh t a nd , as the ground
sloped away steeply fro m th is po int, the pilot was
able to safely lower the nose and accelerate to
normal fl ying speed.
(co11li1111ed on pagP 14)
Aviation Safety Digest 105 I 7
�Editorial
A chance in a million a pilot contribution
In telling this story I h ave no in tention of
castigating m yself fo r what happened but I will
endeavour to criticise m y decisions in order that
others may learn from m y experience.
The aircraft involved was a 1966 model Cessna
182 which I had flown for 45 hours in the last six
months. It was one May morning when I filed a
flight plan from Arch erfield to Barcaldine tracking
over the Taroom NDB . T here was no significant
weath er indicated in the forecast a nd I planned to
fly at 6500 feet. I departed Arch erfield at
approximatel y 1150 hours local time. My track was
direct Archerfield- Taroom and with an air ways
clearance I climbed to 6500 feet. T his put me on
top of four oktas of scattered cumulus but the flight
to Taroom was uneventful. I heard a number of
weather reports on the radio indicating poor
weather east of m y track , but a report from a pilot
who had d eparted Ba1·caldine indicated the weather
there to be clear. Just afte r m y T aroom position I
encounter ed a build-up of cloud consistent with the
previous reports from other pilots. Knowin g the
weath er to be clear, I advised Flight Service that I
was climbing to 8500 feet and this put me on top of
eigh t oktas of stratus. I am not endorsed on the
ADF but nonetheless I use the instrument and h ad
it tuned to the Taroom NDB .
Ap prox imately 120 miles north west of Ta room a
break in the cloud confirmed m y p osition as over
th e Carnarvon Ra nges. Some ten or fifteeen
minutes after verifying m y position I first noticed
shi ny spots on the ri ght hand side of the
windscreen. It wasn't very long after this that there
was a secondary effect on the windscreen of a
smudginess and then r ipples run n ing from the
bottom to the top. My position was about 30 miles
north west of Consuelo Peak, flying at an a ltitude of
8500 feet on top of eight oktas of stratus and I
realised that the engine was losing oil. A quick
glance at my maps sh owed Springsure 50-60 m iles
away and ru gged country a ll the way; Barcaldine
still 180 miles; Charleville about 140 miles and
Tambo over 100. It was a t that stage I r ealised that
as a fligh t planne r I was worth about five per cent.
My first real n eed was a break in the cloud so
th at I co uld verify m y position. It had to come soon
- or so I hoped - Barcaldine weather was okay
b ut th at was 180 miles away. I figured I would hang
off calling Charleville and telling the m of m y
problem u ntil I could give them a more accurate
idea of m y position - could not be real sure above
e ight oktas of stratus. Sudden ly, to m y Jeft a huge
valley in the clouds a nd at the end Mother Ear th
below, so I turned left a nd down I went. By this
stage the r igh t hand side of the windscreen was
a lm ost completely covered with oil and I kn ew I
8 I Aviation Safety Digest 105
had a real problem. T he cloud base turned out to
be 3500 feet a nd a gla nce at th e map sh owed th e
elevation in this a rea at between 2000 a nd 2500
feet. So that pu t me at 1000 fee t a bove what I
found to be rugged sandstone cliffs a nd deep
gorges covered with heavy scrub as far as the eye
could see in a ll directions.
At this stage I called Ch arleville Flight Ser vice
and told the m of m y situa tion which I now realised
was pretty desp er ate. l would like to thank the
operator at Charleville, who had declar ed a n a lert
phase on the fligh t, for not harrassing me at this
time for a position report as this m ight have added
to m y problems. I have flown this ar.ea a number o f
times and I knew that the nearest flat country that I
could land on was in the d irectio n of Au gathclla or
Tambo and that the road running
Augathella-Blackall, if I made it be fo re the oil
pressure dropped , was sui ta ble to lan d on. I tried to
tune the Blackall N DB but could n ot get a whis p er
out of it. Still too fa r awa y.
So I ch anged to a h eadin g that I h op ed would
put me in this area. I was flying for abou t ten
minutes after m y desce nt hoping to see the black
soil plains in the d istance - the windscreen was
a lmost completely covered with oil - wh en
suddenl y in the midd le of my last re m aining area of
visibility out the windscreen, a mon g this d ense
scrub, the most welcome sight I have ever seen in
m y life - an airs trip lying straigh t in front of me.
My first temp tation was to fl y a straight-in
approach but I resisted and d ecided to fl y a proper
circuit. There was no wind d irection indicator but that was th e least of m y wor ries. I had only
recently com pleted th ree hou rs of nigh t circuits a nd
I felt this helped me to la nd the aeroplane incident
free. I feel I u sed good sense in fl ying a p roper
circuit and getting a look at the strip. Eve n thou gh
there was nothing tha t re presen ted a hazard o n the
strip at the time , within two hours it was covered
with grazing horses. A straigh t-in approach then
could h ave bee n ra ther r isky. As it transpired I had
landed on a cattle p ro pe r ty o f some h alf million
h ectares of which I had used approximately two,
the only two on the p roperty clear of trees.
I leave m yself open to constructive criticism but
in the future, wh ere possible, I know I will fligh t
pla n shorter legs between points tha t can be
positively recogn ised a nd I will certai nly th ink twice
before fl ying over a n y large area of e ig ht oktas of
cloud •
Aviation Safety Digest 102 contained an article titled 'Acrobatics and struc~ural limitations'. The aim of
that article was to clarify any doubts that readers might have _had concerning th~ manoeuvres
permitted in normal and utility certificated airc~aft._ The followm_g letter was received from a
well-known aerobatic pilot in response to pubhcat1on of the article.
...
' I read with interes t the a rticle, "Acrobatics a nd
structural limitations" in Digest 102. Perhaps my
exper ience causes me to review artic~es su ch as
yours too criticall y, but I d o react this way becau se
of several factors.
'Firstly, those who wish to learn the ar_t of .flying
u suall y read avidly. Secondly, beca~se ?f .their lack
of ex pe rience , they are u nable to discn m mate and
this can cause problems. For exa mple, they may
give irrelevant detail u nd ue i~porta~1ce or .they may
misinterpre t the wri ter's meamng. Fmally, 1.n a n
effort to discriminate between d ifferent artJcles,
they a re apt to give mor e im por ta nce to articles in
official magazines compared to the information
which may be available from other sou rces. .
Therefore, I believe one segment of you r arucle
d eserves comment.
'A Cessna Aerobat was used in all your d iagrams.
This is a good a ircraft on which to learn basic
aerobatic manoeuvres. The aircraft is ligh t on th e
con trols, r easonably r esponsive a n d it has the add ed
advantage that it is fam iliar to many students wh o
have already learnt to fly in the Cessna 150.
However , as the aircraft has a clea n d esign , even a
20 d egree dive will p rod uce a rapid accele~ation.
Wha t then is the connection between th e aircraft
performance, m y previou s observation s and your
diagrams?
'Your fi nal d iagram illustrates a Cessna A~robat
performing a vertical e igh t; the refo re'. a ? ovice
aerobatic p ilot may be excused for behevm g th at th e
Aerobat can easily perform this manoeu vre. H e has
seen the manoeu vre perfo r med by that aircraft in
an official magazine, th erefore it h as "official
approva l" . This manoeuvre is not simple in an y
aircraft, and if p erfor m ed in th e Acrobat the
aircraft could ver y well exceed:
- the VNE at th e bottom of the second loop .
- the maximum permissible engine RPM, and
- the 'G' limit of the a irframe.
'I realise that the "rules" state that th e instructor
sh ould be rated on the manoeuvre, b u t few
instructors would be so rated. Unfortunately, I
believe, the in clusion of th is manoeuvre and the
Aerobat in your article may stimulate the more
.
inexperienced instru ctors and stu dents to attempt it.
'I commend you on the general content of the
article. With the increased inter est in this typ e of.
flying, I h ope we may exp~ct many more a~ticles m
the Digest to keep aer~batics as safe as possible .
H owever, in fu tu re articles, I h ope that a more
cautious ap proach will be evident.'
T he above commen ts are con sidered to be valid an d
we commend the writer on h is obser vations. T he
u se of the same aircraft for all d iagr ams arose from
editorial expediency.
With th e exception of inver ted fligh t a nd flick
manoeuvres, aircraft in th e acrobatic category do
not normally h ave fligh t m a nual limitations ~ith
r espect to particu lar manoeuvres. The onus 1s
therefore on th e pilot and the op erator to
d etermine what activities a particular pilot/aircraft
combination may engage in safely.
Our enquiries suggest th at it is, in fact, d ifficult to
perform a 'ver tical eigh t' in a Cessna Aerobat and
not exceed th e aircraft limitations. It would a ppear
that pilots of the Cessna Aerobat pr efer to
approximate the 've rtical eight' and complete. th e
top loop with the aircraft nose a bove th e honzon ,
then perform the half roll still clim bin g slightly, and
commence th e lower loop with the airspeed not
above 60 kn ots. This procedure red uces the
possibility of inadvertently exceeding the a ircraft
limitations.
Ensure th at you know the a irc raft limitations
when you pu t yo ur own to the test•
Unorthodox but effective
Problem
The safety officer a t a large air port was concer ned
about a certain ll ying school's habit of leaving '~1 heel
chocks lying abo ut the tarmac. H e correctly ?~heved
that, as the a rea was often used by oth er taxi-mg
aircraft, the chocks p resented an un necessary
hazard. Repeated atte m pts to have th e school take
a p p ropriate action h ad no resul t.
Solution
Removal of the chocks b y the safety officer. Faced
with the prospect of either con ti nuall y tri ppin.g to .
th e safety office to re trieve the chocks every tune 1t
h appened, or replaci ng th em at a cost of $16 _per
pair, the flying sch ool qu ickly realised it was far
more practical to remove the chocks from the
tarmac themselves. Perhaps not th e most on hodox
way to impart a safety message bu t effective,
n evertheless •
Aviation Safety Digest 105 I 9
�One down and one to go the facts about engine failure
in a light tWin
I
,,..
'
!his article i_s abou! pilots who fly l!ght twin-engine aircraft (below 5700 kg maximum weight). More
importantly_ it expl~ms ~o~ those pilots can save the lives of their passengers and themselves by
understanding the 1mphcat1ons of an engine failure at a critical phase of flight.
Bob was obviously proud of his new aeroplane.
Brightly painted, the light twin was visual proof of a
very successful business. Although he would n ever
admit to it being other than a mea ns of transport, the
amount of care and aLtention Bob lavished on the
aircraft suggested a relationship not often seen
between man and machine.
'Bette.r than the old single; gets there quicker and
Lwo en gines are better than one.' Bob never seemed to
t!re of extolling the virtues of his aeroplane, and his
listeners usually responded in a gratifying, if perhaps
predictable, manner. It was generally agreed he h ad
?one the right thing; the previous aircraft was old, and
m~trument flying in a single did not appeal. Hence the
twm, complete with the very latest navigation aids and
multi-engine safety. Bob quickly mastered Lhe a rt o f
twin-engine fl ying and rapidly began to accumulate
hours.
The day was fine, wilh a hint of possible late
afternoon thunderstorms as Bob tax ied the aircraft. At
the holding point, he carried out his u sual, meticulous,
pre-take-off check a nd reviewed the e ngi ne failure
e mergency drills. Lined up and rolling for a flapless
take-off, with the minimum control speed of 8 1 knots
and best single-engine rate of climb speed of 108 knots
firmly in his mind, Bob should have been conditioned
to Lhe possibilily of a n en gine failure. Nevertheless
when it did happen , at about 90 knots and with the
landing gear still down, he was taken by surprise. The
change of engine noise and sudden yaw momentarily
froze him in his seat before he reacted.
'Stop the yaw - wings level - check maximum
power - get the gear up - flaps are up - nose down
Lo get l 08 knots - can't, too low - which
e ngine - d ead leg-d ead engine - check the
throttle - yes, Lhat's it - feather - h ell, the speed's
d own to 85 knots! . . . .'
·
. Still under control but with a slowly decreasing
airspeed , the aeroplane descended into trees about a
kilometre beyond the end of the run way.
Why?The day was warm, but not hot. 'Shirt sleeve
conditions', the investigator had said . The fuel tanks
h ad been fu ll a nd even with some cartons of freight on
board, the aircraft was certainly h eavy but still about 50
kilos below maximum take-off weight. A detailed
examination of the wreckage h ad shown that the
op~rating e ngine was capable of developing full power
at impact.
What we nt wron g? Was it the pilot, the aircraft, or
something else? T he pilot had performed his normal
checks faul tlessly and , after the initial shock of the
10 I Aviation Safety Digest 105
e ngine failure, he did wha t he thought was correct.
Other than the failed engine, the aeroplane was in first
class order. What then we nt wrong? Another
unexplained accident? Not a bit of it! Bob was simply
un_fortt.~nate to experience an engine fai lure in his light
twm at Its most critical phase of fl ig h t - just after lift
off T h e warm day and heaviness of the aircraft d id not
help matters.
Why did the aircraft fail to climb? Isn 't it a basic
design concept of m ulti-engine aeropla n es that failu re
of an ~~gine will not compromise its safety?
Surpnsmgly the a ircraft designer could con sult his
graphs and charts and sh ow that, for the conditions
existing a t th e tim e of the accident, with the gear clown,
the propeller on the failed engine winclmilling a nd a
lower than optimum airspeed, the aeroplane would
descend al 130 feet per minute.
Is this unique to Bob's aircrafl or a performance
characteristic sh ared with o ther light twins? If the
la lt~r, how can multi-engine aircraft be built,
ce~llficated a~d sold if incapable of ma intaining
al~1~ude or climbing following an engine failure at a
cnucal phase? To answer these questions it is necessary
to ~o ns1de_r some basic airworthiness design
ph1losoph 1es. As a starting point, a comparison will be
n:iacie between light twins and large transport category
aircraft.
The fail-safe concept
In f<;> rmal terms, light aircraft are those having a
max imum take-off weight of 5700 kilogrammes or
less. This quite arbitrary barrier separates the large
transport ~ategory aeroplanes from the normal, utility
or acrobauc category aircraft.
Designed in accordance with the 'fail-safe' concept,
the la rge transport category aeroplane can be said to
;eI?rese~t.the ~pitome ofaerial safety. Simply speaking
_fa1l-saf~ implies that flight safety will not be unduly
Jeopardised ~houl d there be a failure of any one
element (or m some cases multiple elements) within
any of the various systems comprising the complete
aero plane. For example, wing structures have mul tiple
load paths a~d _essential items of equipment are
dupl_1catecl ;. similarly there are usually at least two
q~alified pi.lots. To sustain this concept in terms of
fhg~t performance automatically requires at least two
engmes and conseq~ently all large transport category
aempl~nes are mult1-engmecl. Shou ld an engine fai l a t
a ny pomt, from the beginning of take-off to the
completion of landing, the flight can be safely
terminated or continued.
Take-off performance information is given to the but these standards do not, nor are they meant to,
provide as high a level of safety as the transport
pilot in the form of accelerate-stop and engine
failure-continued take-off distances, Logether with the category rules.
Why not design a multi-engine light aeroplane to the
appropriate decision and take-off safety speeds;
commonly known as V1 and V2. The aeroplane must transport rules and take full a d vantage of th e extra
be capable of making both an accelerate- stop and a
safety? I t can be clone and has been done, but like
continu ed take-off within tl1e runway length available. everything else it must be paid for. The price is high,
not only in terms of the initial purchase and
Take-off and en rou te flight paths are established
assuming engine failu re at the most critical point, and subsequent maintenance costs but also in relation to
the approach and landing segments a re similarly
the operating economics. T o realise the engine-failed
treated. T h e weight of th e aeroplane must be adjusted
performance of the large aeropla ne, the average light
before take-off to accommodate the most cri tical of the twin would be so payload-limited it would be vir tually
above flight phases. The encl result is, of course, the unusable. If light aircraft are to be operated in a
achievement of a very h igh level of safety, so much so
realistic manner, a level of safety lower than that
Lhat airline travel ranks significantly better in this
present in large transport aircraft, must be tolerated.
regard than the mor e traditional fo rms of transport.
The light aeroplane, on the other hand , is designed Performance standards
and certificated against a much simpler set of d esign The most immediately a pparent differences between
the Lransport category and the light aircr aft design
ru les. In Australia, these rules are given in Air
codes
are those relating to fligh t performance. Every
Navigation Order 101.22. This document in turn
pilot
who
has flown a single-engine aeroplane is well
specifies a defin itive set o[ light aeroplane design
standards, the American Federal Avia Lion Regulations aware of the consequences o f engine failure; at best a
damage-free forced landing, at worst a fatal accident.
Part 23.
The light twin, however, would seem to gr eatly
The fail-safe philosophy as such does not form the
foundation o r this code, a fact easily demonsLrated by improve o n this situation. With the failure of one
engine the available power has only been halved, but
the obvious presence of a great. man y single-engine
the question is, can the re maining fifty per cent be used
aeroplanes. Just as power plants need not be
to
sustain flight? The only real answer is that it
duplicated, neither do many other components of the
d epends upon which phase of flight the a ircraft is in
design; and of course single-pilot operation is
common. The IighL aeroplane design standards have when the engine fails.
Unlike transport aircraft, where positive
evolved over the years to the poinL where modern
one-engine-inopera
tive climb perfonna nce is always
a ircraft h ave a safety record which, from a n
available, the light twin is requi red to demonstrate
engineering point of view at least, is very good indeed;
Aviation Safety Digest 105 I 11
�e ngine-out performance only in the e n r oute
s urprise th a t th e single-engine climb rate of an older
configuration . Ta/le-off, a.pjJroach and landing are not
a ircraft could b e as m u ch as 150 feet p er mi nu te less
considered. In o ffi cial la n guage, light twins are
than the certificated p erformance.
'aeroplanes with a performance such that a forced
landing should not be necessary if an e ngine fails after
take-off and initial climb'.
The effect of changes in configuration and
The take-off and initial climb are thus consid ered to conditions
be a ll-engines-operating ma noeuvres and the fli gh t
As well as being fa miliar with basic performance
manual take-off distances and take-off climb data are limita tions in asymmetric flight, pilots of light twins
o f the. manner in which
scheduled on this basis. Do no t expect to find V1 or V2 must also be aware
.
, .
speeds for a light twin ; in the context of an
pe:forn:iance ~viii chang:~_1f a~1y param.e ter ~ ~~ec~mg 1t
all-engines-operating p erformance, they have no
ch a_':1 ges. Consider ~ typICa l p1sto11-engm e tv. 1 with an
meaning. The Australian flight manual take-off
engme_failed ~nd _Its propeller ~eathered. !he
distance is the all-engines dista nce from a standing
operatmg engm e_1s set for max1mur:i c_ontmu_ous
start to clear a 50 foot obstacle, multiplied by an
pow~r, the speed 1s that for t~e best sm gle-en gme rate
appropriate safety factor (normally between 1.1 5 and ~of climb and_ the ae'.oplan_e is b_a nked fi ve d:&"re~s
l .25). After take-off the aircraft must be able to
towar~s the hve engme. Wi th this state of eqmhbnum
achieve at least a six per cent g radient of climb, once
established, let us make some cha nges and observe
again with all engines going.
what happens.
Not until the aeroplane is cleaned up, at a reasonable
Speed.
An y increase or decrease in speed
height above obstructions a nd has reached an airsp eed
from the optimum will have the
at least equal to the best single-engine rate of climb
same resu lt - the rate of clirrib
speed can any reasonable assurances be made as to the
will be reduced. An
one-engine-inope rative performance. There can be a
approximation for a typical
period of up to 15 seconds after lift-off where, should
piston-engine light twin would be
an engine fail , an accident may very well occur. That is
fo r a climb redu ction of some
the type of risk the light twin pilot has to face du r ing
30-40 feet per minute for a speed
take-off and initial climb. The actual ris k p eriod can
var iation of l 0 knots either side of
vary greatly of course, depe nding as it does on
the best rate of climb speed .
aeroplane typ e and weight, and on a tmospheric
Reduce the speed more than I 0
pressure and temperature; under fa vourable
kno ts and the reduction in ra te of
circumstances it m ay well be as low as a few seconds.
climb will be very much greater.
But exist it does and so provides a gra phic illustra ti on
Flaps.
Exte nsion of the flap s to the
of the diffe rence in safety levels between large and
take-off or landing position will
sma ll aircraft.
increase d rag a nd red uce the rate
of climb. It is difficult to be precise
En route climb requirement
because of the differe nt flap
As already mentioned , the one-engine-inoperative
systems, but extension of the flaps
climb standard is concerned with the en route phase
to the normal la nding position
o nly. The Australia n requirement is to maintain
could red uce the rate of climb by
h eight for VFR o pe ration and a 0.5 pe r cent gr adie nt
more than 200 fee t per minute .
of climb for IFR o pera tion . These performance levels
On the other hand very small fla p
must be demonstrated at maximum take-off weigh t, a
extensions (two to four d egrees)
pressure altitude of 5000 f eet a nd an o utside air
m ay be bene ficial. A n y such gains
te mperature of l 5°C. The aeroplan e must'be in the
a re small however, a nd
normal en route configuration with the ino pera tive
expe rime ntation should be left to
e ngine stopped and its propeller feathered. The
the m a nu facturer's test crews.
operating engine is se t for maximum continuous
Landing gea r. Extenswn of th e ·gear could also
power. Climb speed will be a ppropriate to the best
r educe the rate of climb up to 200
gradien t of climb which , for all practica l purposes, will
fee t p er minute . It is wor th
be approximately equivalent to that fo r best rate of
reme mberin g tha t som e types of
climb. In absolute terms the a bove p e rformance levels
la nding gear, in the process o f
a re not high ; for example a 0.5 per cent gradient
re traction , might have more drag
re presents a ra te of dimb for th e ave1·age light twin of
tha n wh e n d own a nd locked . This
between 4 0 and 60 feet pe r minute. Even so the re are
can be expected if the aircraft h as
quite a number of m odern ae ropla nes tha t need to be
wheel well covers which are closed
weight limi ted to achieve even this performance.
whe n the gear is d own , but open
Ma nufacture rs must produce aero pla nes th at
du r ing retraction.
Propelle r.
comply with th e applicable design require me nts.
Ene r gy is extracted from the
When carryin g out his certification trials a
airstream by a windmilling
m a nufacturer uses a new, o r near n ew, ae ro pla ne with
propeller a nd th e result, as
the e ngines and airframe in better than average
ex pected , is increased d1·ag which
condition. All aeropla nes, h owever, d eteriorate to
redu ces the rate of clim b between
some extent after they h ave bee n in ser vice for a ti me;
l 00 and 200 feet p er minute.
Fligh t a ttitude . Cer tification rules p ermit five
e ngines may no longer d eli ver full power , and d oors
a nd pa nels might not fit as well as they d id. Com bined
d egrees of bank towards the live
with a n indiffere nt exterior finish it should come as no
e ngine for complia nce with th e
Factors affecting single-engine performance in a light twin
In your favour
• Power available from the live engine
Against you
• Extended landing gear and flaps
• Windmilling propeller
• Any loss of power from the live engine
due to age, maintenance, etc.
• Variations from best rate of climb speed
• High aerodrome altitude
• High ambient temperature
• High aircraft weight
...
• Lack of pilot skill
I( you act to red uce the effect of those factors working against yc:iu , the aircra ft ma~ mai ~ tain h eigh t or
eve n climb. Assess each ta ke-off before you go and plan yo ur act10ns should an engme failur e event uate.
(
..
one-engine-inoperative clim b
r equiremen ts. Most
m an ufacturer s take ad vantage of
th is. In wings-level asymme tr ic
flight an aircr aft will sideslip while
main taining headi ng, th us
increasing d rag. Bankin g towar ds
the operating e ngine red u ces
d rag by reducing the sideslip as
well as th e amoun t of r udd er
required, a n d the rate o f climb
can incr ease b y 10 to 20 feet per
minu te.
Po>ver.
O n e-engine-inoper ative climb
performance is achieved with the
live engine produci ng maximum
con tinuous p ower wh ich fo r many
engines is take-off p ower.
Obviously, an y red uction in
p owe r will cause a redu ction in the
rate of clim b.
T h e result of var yin g most pa ra meters from the
cer tification cond ition is obviously detrime ntal. Ca n
a nything be d o ne by the pilot to improve th e situation ?
For tuna tely at least th ree positive actions can be taken.
Complia nce with th e p er for ma nce standa1:ds .
req uires d emon stratio n a t maximu m ta ke-off weigh t,
at an altitude of 5000 feet a nd a temperatu re of I 5°C,
i. e. ISA plus l 0°C. By reduci ng th e weight, a ltitude o r
te mpe rature, the clim b pe r form ance can be improved .
A redu ctio n in weig h t will result in a n increase in r ate
of climb. This is a mos t importa n t factor as the pilot ca n
readily cha n ge the a ircraft weigh t by adjusting fuel
a nd payload . T he rate of climb o n one e ngine can var y
by app roxima te ly 15 to 20 feet per min u te fo r each o ne
per ce n t cha nge in weight. If you h ave loaded your
aircraft to its fligh t m a n ual limit a nd not considered
the im plicatio ns o f an e ngine failure, you are living in a
d ream world .
For most ae rnp lanes the lower the altitude, the
better the clim b perfo r ma nce . Fo r the typical ligh t tw in
(with one engin e sto pped) the ra te of climb will
d ecrease a p proxima te ly 30 feet per min ute fo r each
1OOO fee t in crease in alti tu de if the aerop lan e is
equ ipped with normally aspira ted en gines. If the
ae roplane has tu r bo-char ged en gi nes the r ate of climb
ca n be expected to d ecre ase by up to 10 feet per minute
for each 1000 fee t increase in altitud e. H ow can you
offset th is effect? By adjusting the a ircraft weight. For
instance, if ta ki ng off from a n aerod rome at 3000 feet
above mean sea level a r eduction of fi ve per cent in the
take-off weight will offset the red uced rate of climb
d ue to th e altitude (fo r the typical ligh t twin) .
As with altitude and weigh t, so it is with
temperatu re. Reduce the temperature a nd the rate
or climb will increase; about 20 to 30 fee t per
minute for each l 0°C change. B y adjusting
departur e times, the pilot can take a d va ntage of
lower ambiem temperatu res. Try leaving earlier in
the day. Weigh t adju stme nt can a lso be used to
offset the effect of temper ature .
O bviously th ere a re a lot of ligh t twins fl ying , and
they have their sh are of e ngine fa ilures. Accidents
as a res ult of these failu res are fo r tu nately ra re.
The reason , of cou rse , is that n ot all e ngine fail ures
h appen d ur ing the take-o ff phase, at high
aerodrome altitu des or in high a mbien t
te m peratures.
T he Austral ian stand ard s h ave been d esigned to
provide the required level of safety o n th e basis of
achieving a satisfactory record ove1· the complete
spectrum of operatio ns. Ru t the re is no room for
complacency; d uring ta ke-of f, the
one-engi11 e-inoperntive clim b capability o f ligh t
twin-engine aeropla nes is not gua ra n teed, a nd is in
markclcontrast to the gen er a ll y sprigh tly
p erformance with both engines operating.
It is vitall y impo r ta nt to rem em ber that the
requireme n ts for single-engine perfor ma nce relate
only to the en rou te phase of fli gh t with the ai rc raft
in its lowest d rag configu ratio n . Aircraft are usually
designed to meet th e mi n imum requ iremen ts and
an y additional si ngle engine performa nce is
fortuitous . It is a pilo t's res ponsibility to ta ke
whatever steps he can to enhance this per fo r mance
in th e event of an engine fai lure.
12 I Aviation Safety Digest 105
Aviation Safety Digest 105 I 13
�Pre-take-off emergency considerations
Aircraft weight. Adju st to cou n ter the effects of
hig h altitude and high
temperature.
Safety speed.
Check th e flight manual - do
not let the aircraft sp eed fall
below this in flight.
Runway length. Use the lon ges t suitable
run wa y. If an en gine fails
sh ortly after lift-off, excess
runway a nd over-run areas can
b e used for a n immediate
landing.
Single-en gine
climb sp eed s.
Terrain.
If an en gine fails with gear
and flaps exte nded befo re the
speed for best single-engine
angle of climb is reached
consider a forced landing
immediately.
If continued flight is elected ,
achieve a nd maintain th e speed
for best single-e n gine rate of
climb.
Will ter rain affect your actions
in the event of an en gine
failure? Will best single-engine
a ngle or rate of climb be
adequa te to clear obstacles or
gradien t o f th e ter rain?
Many light twi ns committed to single-engine
flight soon after take-off in adverse conditions are
only capable of a controllable rate of descent.
From one of our readers - a
valid message from the past
In the event of an engine failure during take-off or
initial climb:
• E nsu r e that th e maximum power available is set
- maintain best single-engine rate of climb speed.
• C h eck the gear and fla ps are re tracted
- maintain best single-engine rate of climb 5peed.
• Identify the failed en gine (dead leg-dea d engine
and the instrume nts) an d confirm by slowly
closing its th rottle
- maintain best single-engine rate of climb speed.
• Feather the propeller on the d ead en gi ne and
check for fi r e. If time p er mits complete the
e ngine failure d rills.
- maintain best single-engine rate of climb speed.
• If th e aircraft can maintain a safe ma noeu vr ing
h eigh t, position for a lan ding - if not select the
most suitable forced la ndi ng area.
Although Bob is a figment of our imagination,
his type of accident is not. Too many pilots could
point to our opening story and say, 'You have it
all wrong, my name isn't Bob!' •
(continued from page 7)
The pilot ad vised Lae Fligh t Service th at th e
aircraft h ad been d ama ged a nd that h e would be
returning to Lae. Reaching the circuit area , h e
feathered the starboard prop~ller and land ed the
aircraft on a cleared grass a rea alon gside the sealed
runway. As the fuselage contacted the ground , the
aircraft slewed to the right throu gh 90 d egrees and
came to rest on the ed ge of the runway. Neither the
pilot n or an y of the passen gers was injured.
The aircraft was exte nsively damaged by its im pact
with the embankme nt. The r ight ma in landing gear
was torn from its h ou sing in th e win g, b uckling the
surround ing structu re a nd th e right hand flap. T he
la nding gear assembly remained a ttach ed to the
wing only by torn and buckled shee t metal that had
fo rmed the rear box of th e righ t h a nd n acelle.
Althou gh th e wh eels and brake u nits were fou nd to
b e se rviceable, the right hand brake was ch oked
with mud and grass.
Obviou sly, the surface over th e full width of th e
d epartu re str ip d id not com p ly with the releva nt
ta ke-off a nd land ing area sta nd ards; h owever , th e
central 10 metres of th e strip was quite satisfactor y
for take-off a nd landing. At th e time of the accident
th e grass on eith er side of this cen tral area was
14 I Aviation Safety Digest 105
de nse and tan gle d , and betwee n 15 and 20 cm
deep. Clearly, th e rolling resistance of this th ick
grass and th e inadvertent wh eel braking caused b y
th e grass-ch oked righ t bra ke ser io usly degrad ed the
aircraft's ta ke-off p erforma nce. It is no t surp r ising
th erefor e , th a t the a ircraft failed to accelerate to
take-off speed in the available strip length. As it
h a ppe ned , h ad it n ot been fo r the sh allow
embankmen t at the e n d of the strip, which literall y
threw th e aircraft into th e air, a nd the d eep valley
beyond, the aircr aft may well h ave crash ed in to th e
trees rather tha n j u st ma naging to scra pe through
the tops an d remain airborne.
T h e pilot h ad op erated into the strip about 100
times without incid ent and was fa miliar with its
characteristics . It is certain th at h ad he taxied from
th e parking bay to the top of th e strip a nd u sed the
full length of the fir m , central por tion ~or ta ke~off,
the aircraft could h ave become safely airborne m
less than two-th irds of the available dista nce, and
thus com pleted th e fli ght without incide nt•
•
I
..
Alth o ugh I a m not a licensed p ilot a nd fly only
occasionally with a friend, I still have a n e nthusiasm
for a eropla nes a nd read the Aviation Safet)1 Digest
with great inter est. T he regula r occurre nce of
accid en ts caused by pilots pressing on in mar ginal
wea the r seems as prevalent today as whe n I was a
pilot in the RAAF from 1942 to 1946. Perhaps an
accoun t of m y own lack of ca u tion in 1944 may give
you an opp or tunity to repeat th e lesson once again
with a d ifferent slant - eve n if it is 35 years a fter
th e event.
O n th e morni ng o f 11 December 1944 I flew an
RAAF Vengeance fro m East Sale to Tocu mwal. It is
abou t 290 km and Lh e track lies across the rugged
Sou thern Alps, with Mount B u ller r eaching u p to
abou t 5500 feet. T h e weath er was fi ne a nd the
fligh t took abou t an hour.
At th at time I had logged about 500 hou rs in
single-engine aircr aft, with over half those hou rs on
Ven geances which I h ad bee n flying continuously
for more tha n a year , including a spell in a d ive
bomber squad ron. I me n tion this only to indicate
tha t I felt qui te comfortable in the aeroplane.
I took off on th e return flight from Tocumwa1 at
1700 hou rs without getting a route weather forecast. It
had been fi n e all th e way that morn ing, it was clear
now at Tocu m wal, so wh y waste time wh en I could ·
be on m y way and lookin g fo r ward to downi ng an
a le in the m ess at East Sale by 1820 ho urs.
I climbed to the planned cru ising altitude of 8000
fee t, adj usted revs , boost and mix ture, an d settled
d own for a pleasan t late afternoon view of the Alps.
J ust p as t Ben alla clou ds loomed a head, so I began
climbin g with th e a im of eith er flyin g over them or
through th e 'ca n yons' between th e tops. At 14 OOO
fee t over Mansfield it was obviou s tha t this plan
would no t work. The clou d tops seemed to be over
20 OOO feet a nd the choice was to retu rn to
T ocu m wal or pr oceed into cloud on instrume nts.
I chose th e latter cou rse. Lining u p m y gyro
compass with the magnetic compass and ch ecking
all the blind fl ying instru men ts, I e ntered cloud. My
plan was to continue on cou rse, let down to l 0 OOO
feet, fl y fi ve minutes past ET A, the n if still in clo ud,
to let d own straight ahead over Bass Strait. It would
th e n be a simple matter to tu rn a nd fly north to th e
coast, which I kn ew very well in th at area.
Not lo ng after en tering cloud , severe turbulence
and freezing con d ition s were encou n tered . T his in
itself was nol par ticular ly alarming, since the
Ve ngeance was a ve r y stabl e a nd rob ust mach ine,
with wings built to withstand abo ut 12g. Perhap s in
a spa1:tan sort of wa y I was even e njoyi ng the
expe rie nce.
Sudd enly the situation changed . T he airspeed
a nd rate of cli m b need les llickered and assumed
mea ningless positions, a nd l became d ecided ly
uneasy. T h e altimeter bega n to unwind and the
familia1· h iss of air p ass ing the canopy indicated
h igh speed. T h e a ircraft must be in a spiral dive bu t
what th e hell sh ould I d o? Glancing quickly outside,
the penny d rop ped. Th e wi ngs wer e covered with
clear ice and the pitot head was encased in it too. I
switched on the p itot h eat and prayed it was not too
late.
Just as sud d e n!y as they had gone unserviceable,
th e instrum ents registered again. T h e pitot hea t
had worked mercifully fast. T he airspeed was over
350 knots and th e rate of descent was 'off Lhe
clock'. First, ge t lhe wings level on th e artificial
horizon, th en pu ll out of th e d ive. When this was
achieved th e altimeter read well u nder 7000 feet
and Mou nt Buller was probably not a ll Lhat far
awa y.
Stabilized again on course at 8000 fee t in
conLinuing turbu le nce, I waited for ETA plus five
m inu tes and bega n to le t d own. At this time I h ad
been on instrume n ts for about 30 mi nutes, and with
l OOO feet showing on the altimeter, was still in
cloud and looking a nxiously for the ocean . At 800
feet I broke o u t in heavy r ain a nd smartly turned to
the north.
After l 0 minu tes , when no coastline appeared ,
m y confidence was evaporating. Was the compass
aslray? Maybe I was hea din g ou t to sea. I asked my
rear seat passenger what h is compass read - same
as mine. O kay, bu t wh at had happened to
Aus tralia?
Five minutes later we emerged from the rain into
reasonably clear skies and a h ead lay what looked
like Lakes Entran ce. Making a positive
identification , I tu r ned west for Sale . We la nded
there j ust before last light, havi n g taken almosL two
hours fo r the trip. The a ircraft sLill had a coating or
ice when I parked it on the tarmac. The control
tower was u n man ned, as fl ying at th e base h ad
termin ated by m id-a ftern oon . Becau se no depa rture
signal had got through from T ocu mwal, they were
not even expecting u s.
I t was a very chastened yo u ng man who sat in his
room that night a nd pond ered th e extent of h is
foll y. Firstly, no ch eck on the weathe r. T h e n ,
pressing on because il was more desirable to spend
the night a t home base th an to endure the minor
hassles of bunking down elsewhere. And finall y,
fa ilin g to switch o n th e pitol heat in ici ng
conditions.
P ressing on was the major sin because, as it
turned out, we had flown blind through a line or
thundersLorms with all lh eir 1·elated hazards. F ull
marks to the Vultee Ai rcraft Cor po1·ation fo r
building such a stou t aeroplane which sur vived the
tremendou s buffetin g of several cum ulo-nimbus
clouds.
One small afterthought. Despite m y foll y, I
sur vived probably because of regu la 1· sessions on the
ground in the Lin k Trainer. If you m ust fly I FR, it
pays to keep in practice. Bul if you want Lo be an
old pilot, it is better to trea t the weaLher with the
respect it deserves •
Aviation Safety Digest 105 I 15
• I
!
�Recurring fault leads to fatal
ditching
When, in a single-engine aircraft, any problem is experienced with the engine or its associated
controls, the pilot should plan to land as soon as possible to correct the problem and not get caught
out with a total and irreversible loss of power. Because the pilot of a Piper PA28 in the circuit area at
Bankstown did not do this, he found himself unable to reach the runway. He ditched the aircraft in a
river but died a week after the accident without regaining consciousness.
On completion o f the la nding and shutdown the
The aircraft was owned by the pilot and kept on the
line of a flying training organisation. It had recentl y two pilots were me t by a friend of the own er wh o
had been invited along for a short fl ight. The
undergone a major overhau l a nd had been test
owner accepted the aircraft as serviceable and
flown satisfactorily by the chief pilot of the
decided to take his friend for a couple of circuits.
company co-ordinating the overhaul. Before
Start-up and take-off were nor mal and the aircraft
accepting the aircraft, however , the own er
levelled-off at 1000 feet on downwind. Because of
requested that it be checked by the Chief Flyin g
preced ing traffic, th e pilot reduced power to
Instructor from the training school.
maintain separation. When he went to open the
The owner was to fl y the aircraft from th e left
throttle again it a ppeared to catch momentarily
hand seat for the 'acceptance' flight wh ich was to
before moving forward. The two men looked at
initially consist of a circuit and landing. The CFI
each other and the throttle, but nothing was said.
was in the right hand front seat. All was normal
The aircraft ahead was making a wide, lon g
until final a pproach when traffic conditions
circuit, so the pilot of the Cherokee delayed his base
required a go-around. The owner tried to push the
turn and extended th e downwind leg. After turning
throttle control forward from its halfway position
base and making th e appropriate radio call he
bu t could not do so. The CFI also tried withou t
closed the throttle, lowered flap and comme nced
success so he took over control of the aircraft a nd
descent. It became obvious on base leg that power
completed a circuit and landing with the power
would be needed to have 500 feet h eigh t for the
available. No emergency was declared.
fina l turn. The pilot pushed on the throttl e but it
After landing the condition was re ported to the
would not move from the closed position .
servicing organisation. An en gineer inspected the
Despite his desperate attempts to move it, the
th rottle system and decided to remove the
throttle would not bud ge. The pilot hit it and shook
carburettor which appeared to be a little stiff in
it without success. The aircraft was turned o n to
operation. No positive fault was discovered in the
final approach in line with the runway but was
carburettor but the throttle shaft was overhauled.
obviously undersh ooting. When at a h eight of about
No fault was found in the throttle control linkage.
300 feet, still searching for a place to la nd , the pilot
A few days later, when the aircraft was ready fo r
a nother acce ptance flight, the owner again arranged gave a Mayday call a nd continued trying to open
the throttle.
to conduct this with the CFI. A test flight of 48
It appeared to th e passenger that the aircraft may
minutes duration including circuits and upper air
not clear a busy road next to the aerodrome
work with e mphasis on the th rottle opera tion
boundary, and it was at this time the pilot turned
revealed no fa ults. The aircraft returned to the
the aircraft to the r igh t for a ditching in the river.
airport without incide nt.
16 I Aviation Safety Digest 105
Top: A radiograph of the throttle cable from another PA-28 which was damaged during a forced lrmding following engine failure. Note
the initial buckling of the inner cable.
Bottom: The buckled inner throttle cable from the aircraft that ditched in the river. Wear marks on the wires revealed it had been
buckled for some time.
(
The passenger braced himself fo r impactjust
before entry. The aircraft overturned and sank.
The passenger m anaged to exit the cabin through
the windscreen but the pilot was trapped
underwate r until rescue services arrived. T he
aircraft h ad to be pulled into shallow water and
turned upright before the p ilot could be released .
Subseque nt d atailed examination of the wr eckage
revealed a compression failure of the inner throttle
cable at the carburettor end (see photograph).
Microscopic examination of the buckled wires
revealed two stages of wear and the buckling
reduced the cable length by 16 m m . Bench tests
conducted to measure the loading effect of the
buckling indicated that a force of I 0-1 5 kg was
required to move the cable towards the
throttle-open position.
The type of cable used on Lhis throttle control is
common to other aircraft ty pes and compression
failure leading to restricted th rottle movement is
not unknown. The cable cannot be readily
examin ed for internal d a mage and, except for
sophisticated a nd expensive laboratory techniques, it
must be destroyed to be examined. I t is obvious
th erefore that if a ny difficulties a re experienced
with a throttle control and n o positive fa ult can be
established, consideration should be g iven to
replacemen t of the cable.
The real reason fo r this tragic and u nnecessary
accident was not the problem with th e throttle
control - it was the pilot's failure to treat a
recurring but intermittent fau lt with th e seriousness
it deserved . A declaration of a 'Pan' situation as
soon as the fa ult was n oticed would h ave given the
p ilot priority in the circuit and h e could h ave
planned and flown a pattern which would have
required the minimum a mount o f throttle
adjustment. Possibly the previous incident, wh en the
instructor took over control a nd did n ot declare a n
emergency, migh t have a ffected the pilot's
assessment of th e severity of the situ ation.
There is no penalty for seeking assistance - if
there is ever the slightest doubt about the safety of
your aircraft and its occupants try to ' stack the
odds' on your side. Alert A TC or Flight Service
and the appropriate safety actions will be taken. If
you have any special requirements, make them
known. Read the emergency section of the En
R oute Supplement and familiarise yourself with
the procedures. Apart from preventing damage to
an aircraft you may someday save a life - perhaps
your own•
Aviation Safety Digest 105 I 17
�Lack of knowledge can cause
accidents
After landing al his destination and shuuing down
th e e ngine, the pilot of a Cessna 2 10 forgot to turn
off the a nti-collision beacon and the master swiLch .
Some time later, one of the five passe ngers who h ad
been o n boa rd the a ircraft noticed the beacon was
still operating a nd switched it off, but he did not
turn off the master switch as well.
T oward s the end of the day, th e pilot a nd his
passen gers returned to the aircraft a nd board ed it
for the return fligh t. The pilot tried to sLart the
engine but found the battery was flat. H e the n
swung the p ropeller and the engine fired and ra n
for a short time, but cut out. Realising the e ngine
would h ave to be primed before it would r e-start,
and that electrical power would be need ed to
o perate the a uxiliary fuel pump, the pilot obtained
a set of jumper leads to connect the batteries of two
cars to the a ircra ft's 24 volt system .
~he lead s were connected by spring clips to the
ma rn pins in th e ground ser vicing receptacle and
the pump bega n to operate, but the leads
mome ntarily short-circuited and the pump stopped.
After a brief search a blown fuse was located
alon gside the receptacle. As there was no spare the
pil.ot, in order to restore power to the system,
bridged the Lerminals with silver paper. He then
primed th e e n gine with the electric fuel p ump,
removed the silver pap e r a nd, with a nother pilot at
th: c~ntrols, successfully sta rted the e ngine by
sw111g111 g the propeller.
T h e passengers boarded the aircraft again a nd
the pilot carried out his pre-ta ke-off cockpit ch ecks.
The a lternator did not excite a nd conseque ntly,
th ere was no electrical powe r avail<ible at a ll from
e ithe r the aircrafl battery or the alternator.
Concerned that the landing gear may not re main
loc~ed d own without electrical power,. Lhe pilot
d eoded to pump up the pressure in the hyd rau lic
system a nd , after ensuring the landing gear selector
was in the 'down' position , he operated the
e merge ncy extension h a nd pump. Unknown to the
pilot however, the only effect this had was to cause
the landin g gear dilors to open and remain open.
Unable to lower flap without electrical power, Lhe
pilot taxied the aircrafl on to a stretch of gravel
road he was using as an airstrip and began a
fl aplcss ta ke-off wi th the la nding gear d oors ope n.
Th e available le ngth of road was 804 metres a nd ,
after trave lling about 450 metres, the aircraft was
lifted off in a nose high attitude at ve r y low speed.
lt reached a height of a bout 30 or 40 ree t but
would neither climb nor accclerale fur ther. Seeing
power lines directl y a head a t Lhe same he ight, the
pilot realised he would be unable to clear them , so
he lowered the nose to try to gain speed and fl y
under the wires. I mmediately, th e aircrnft lost
18 I Aviation Safety Digest 105
height and the rear of the fuselage and the tail
pla ne began striking low scrub. The a ircraft lost
speed quickl y and, with the pilot still holding
back-pressure on the controls, the a ircraft sank on
Lo the ground. It came to rest, extensively damaged,
600 metres beyond the end of the strip and 1404
metres from the point at which the take-off was
commenced.
The cause of the accide nt was that the pilot made a
premature lift off and the n failed to obtain
sufficient airspeed to a llow the a ircraft to climb. His
lack of knowledge of the va rio us a ircraf t systems
was revealed in a whole series o f ill-considered
action s and d ecisions which culmina ted in an
a~tempted take-off, without electrical services of any
kmd, from an ar ea of ma rgi nal le ngth.
As the pilot ;vas not using the correct NATO
adapter for the ground power receptacle, his e fforts
to supply powe r to the aircraft's electrical system
with jumper leads m eant thar no connection was
made to the sma ll , p olari ty-sensing pin in the
receptacle. As a result, the aircraft ground power
rel ~y failed to e nergise a nd no electrical power was
available throu gh the h eavy duty circuit. Thus,
while the p ilot was able to prime the e ngi ne with
the auxilia ry fuel pump through a parallel circuit,
h e was unable to start the e ngine using the electric
starter. When the e ngine was eventua lly hand
star ted , the alternator would not produce a ny
~mtpul because the re was no battery supply to excite
It. Thus the re was no e lectrical power at all available
tp operate the systems associa ted with normal flight.
Whe n the pilot tried to pump-up pressure in the
h ydraulic system , he did not r ealise that, with the
la nding gear selected 'down' and electrical power
off, the landing gear doo r control valve moves to
the 'doors open' position a nd remai ns there. With
the door control valve open therefore , the la nding
gear d oors opened and remained open wh e n the
p ilot operated the e mergency exten sion hand
pump. The open d oors furth er degraded the
take-off a nd climb performance of the aircraft•
su ffered a total e lectrica l failure.
When the owner-pilot of a Beech 35 was starting
Deciding to land again a t his departu re point, the
e ngine to move his aircraft Lo the refu elling
pornl, the starter turned the engine very slowly in a pilot realised the landing gear would have to be
'series of jerks'. The e n gine started however and the extended manually. H e asked the passenger to
move into the back seat to manually lower the
aircraft was taxied into place.
l~ ndi.ng gear. The pilot pulled the a ppropriate
O n completion of refuelling, the pilot again tried
circmt breaker and then turn ed the m a nual
to start the engine but this time it turn ed over to
compression and stopped. Assessing th e problem as extension h andle once himself to demonstrate to
a flat ba tter y, h e connected jumper leads from a car the passenger how Lo wind the gear down. He
advised his passenger that 50 turns of the handle
ba ttery to the aircraft and the engine started
would be required to fully exte nd the gear.
normally. The pilot noti.ced the ammeter was
showing neither ch arge nor disch a rge but as 'this
The passenger found the handle stiff to o perate
an~ afte.r 25 revolu tions it locked solid, though h e
was its normal position' h e was n ot unduly
concerned . With one passen ger on board, he taxied noticed It could be wound back in the opposite
the aircraft to the ru nway holding p oint and carried direction. The pilot saw that the nose gear
mecha nical indicator showed ' up' and after
out his pre-take-off checks.
attracting the attention of anothe r aircraft returning
After take-off, the pilot selected the landing gear
t? the circuit, it was confirmed by using hand
'up' and set the engine to climb power. H e believed
s115nals that the landing gear was retracted. The
that the landing gear re tracted a t the normal rate
pilot d ecided there was nothing more he could do
a nd, tho u gh he did not see the p osition lights
so he landed the a ircraf t with the gear up.
change, he assumed th e landing gear was up. At
700 feet he began a turn but then noticed that the
Subseq uent investigation revealed that the batlery
single fuel gauge , which mome nts before had
was flat, the generator was unse1·viceabl e and the
indicated nearly full , was now showing only half
gear had been wound up no t down.
capacity. H e selected other ta nks but the needle
continued to fall until the gauge read 'empty' for a ll . In this accident the la nding gear was wound 'up'
ta nk selections. As the a uxiliar y tanks had been full 111advertently. The Airplane Flight Manual specifically
on ta ke-off, and th e mains at least half full , it was
states 'engage h a ndcra nk and turn counterclockwise
clear to the pilot that the aircraft h ad d eveloped an as far as possible (approximately 50 turns)' a nd 'do
not retract the land ing gear man ua lly' •
electrical fault. H e attempted to cycle the landing
gear a nd lower the flaps, but wh e n there was no
r eaction or a n y lights, h e concluded the a ircraft had
th~
\
Aviation Safety Digest 105 I 19
�Systems knowledge the electrical system
Battery
relay
Battery
The preceding accident reports illustrate a factor often revealed during air safety investigations insufficient knowledge of aircraft systems operation, in both normal and emergency conditions. The
aircraft electrical system and the emergency landing gear extension system are those most often
involved in accidents and incidents. In this article we will look at a simple electrical system and
discuss its normal operation, and the recognition and correction of faults which may develop. Later
articles will expand upon this and also discuss other aircraft systems.
_ci--1
Centre zero ammeter
+
+
Battery
Switch
OFF
Without reference to a ny manuals, can you answer
the following questions about the aircraft you
usuall y fly:
•
Is it fi tted with an alternator or a ge nerator?
• What is the difference?
• With all electrical power turned off, does the
ammeter pointer rest in the centre of the scale
or on o ne side?
e How do you check that the alternator or
generator is charging?
•
•
What fault protection indicators are fitted and
wh at actions ar e required if they operate?
What electrical system controls are operable
from the cockpit?
If you were able to answer all the questions the n
you probably h ave a reasonable knowledge of the
electrical system. Even so, we suggest you keep
reading as revision rarel y goes astray.
You will know that there are two main sources of
electrical system power in the aircraft - the
alternator or generator and th e battery. It is
important to understand that both must be
functioning if the system is to operate correctly.
T he correct system operation is readily achievable if
you understand the function and control of the
electrical system components. It is not intended to
try a nd explain basic electrical theory in this article.
If you requ ire a more detailed explanation than
provided here then con sult your servicing
organisation or other qualified persons. for
guidance.
To begin with we will consider a simple sche matic
diagram of th e e lectrical system; a sche matic
diagram shows th e various components in the
system and their ir,iterconnection but d oes not
include actual wiring con nections. In presenting a
schematic diagram a variety of symbols are u sed for
simplicity.
By studying the schematic diagram in coajunction
with the contents of the table follo wing it, you will
be able to see the interconnection of the various
components in the electrical system. The arrows on
the d iagram represent the conventional direction of
current flo w, which is one way, from positive(+ ) to
negative (- ), in a direct current (DC) system .
The table lists the components in a basic electrical
system and descr ibes various aspects of their
operation. We will now explain pa rticular poin ts of
interest about some of these components.
20 I Aviation Safety Digest 105
Voltage regulator
Everyone who flies should know there is a voltage
regulator in the a ircraft e lectrical system which
regulates the output of the alternator or generator
and also controls the recharging of the batter y. The
pilot has no control over the operation of the
voltage regulator.
Alternator
Alternator or generator?
What is the difference? Any rotating producer of
electricity initially develops alternating current (AC)
which flows in alternate d irections. As the electrical
power we require in the aircraft system is direct
current (DC) we must rectify the alternating
current.
In a generator this is done mechanically by fitting
a commutator, made from copper segments, lo the
rotating component known as the armature.
I n an alternator th e rectification is obtained
electronically by the use of diodes, or electrical
rectifiers, which are normally fitted to the end plate
of the alternator.
The important difference between alternators
and generators is in their operation. An alternator
requires an input of electricity from the battery
before it will produce electrical energy. Once
operating, h owever, it will produce a high output at
low r.p.m. and requires less mechanical energy to
operate. A generator does not require a n input
from the battery to produce electrical energy but it
wi.U not produce sufficient output at low r .p.m. to
supply the required electrical loads. Some aircraft
need to be idled at 1000-1200 r.p.m . to ensure that
electrical loads are met by th e generator and not
the battery. For simplicity, the res t of this article will
refer only to the alternators; the information ,
however, will be equally app licable to generators.
Voltmeter
Some single-engine a ircraft are equipped with a
voltmeter which can be used to verify ammeter
indications. Its main p u rpose, however, is in twin
engine aircraft to ch eck load sharing.
Left zero ammeter
B
u
s
B
a
+
r
,-,
Voltage
Regulator
Field
•I
L _
)
Ground servicing
receptacle
0
+
Alternator
Switch
OFF
•
ON
_J
,-
+
L _
_J
Ground servicing
power
relay
Power ___,.,.,.
1111. ____
Circuit
Control
~
Circuit -----7+----
Ammeter
That all-important gauge in the cockpit that is so
often misunderstood. Ther e a re two distinctly
d ifferent methods of connecting the a mmeter into
the e lectrical system. It is necessar y to understand
th is difference in order to appreciate th e a mm eter
indications. We will use ver y simple sch ematic
diagrams to expla in the diffe re nce.
Schematic diagram Simplified Electrical System
(continued on jiage 24)
Aviation Safety Digest 105 I 21
�Component
Location
Function
Operation
Control
Preflight check
Faults
Recognition
Reason
Correction
Battery
Engine compartment
or fuselage
To provide electrical power
for starting, ground and
emergency operation of the
electrical system.
Chemical
production
of electricity
Battery switch
operates
battery relay
and connects
battery to
busbar.
Ensure security,
no loose
connections, no
leaks, fluid
level correct.
Cracked case
Leaking fluid
Old age
Dropped during
servicing
Replace
Discharged
No electrical power
when battery switch
turned on. Starter
will not turn engine
Alternator not
charging, old
age, electrical
system left on
Recharge or
replace battery
Alternator
switch connects
battery to
alternator field ;
similar
for generator
Belt tight, not
broken, no loose
connections.
Not
charging
Ammeter indication ,
gradual loss of power,
radios, navaids and
electrical instruments,
alternator failure
warning light.
Broken or loose
drive belt.
Replace or
tighten belt
Internal failure
Replace alternator
Alternator
(or generator)
On engine
To provide electrical power
in flight
Engine driven
by Vee belt or
gears
I
Voltage
regulator
In engine
compartment or
electrical
compartment
To control alternator
output voltage
Electrical
Battery
switch
Instrument
panel
To operate battery
relay
Manual
Alternator
switch
Instrument
panel
To energise alternator field
Manual
Ammeter
Instrument
panel
To indicate alternator
output or battery
charge and discharge
Starter relay
(or contactor)
Near starter
motor
To connect the starter
motor to the battery
Nil
Connections
Not
operating
As for the alternator
Internal failure
Replace
Switch
1perates
Not
operating
Physical condition
Internal failure
Replace
Nil
Switch
operates
Not
operating
Alternator not charging
Internal failure
Replace
Electrical
Nil
General
condition
No
indications
Pointer does not move
when electrical system
operated
Internal failure
Replace
Electrical
Starte;· :Juttnr. )
or 'start'
position on the
ignition switch
Jtarter motor
operates
Not closing
Starter motor does not
work
Internal failure
Replace
Starter motor
operates
Not operating
Starter motor does not
work
Internal failure
No electrical
power.
Replace
Check circuit
breakers and
fuses.
Battery discharged
Replace or recharge
battery
) '
Nil
)
)- Starter motor
On engine
To rotate the engine
for starting
Electrical
Starter button
or 'start'
position on the
ignition switch
I
Ground servicing
receptacle and
relay
Near battery
To connect ground power
to the aircraft for
servicing
Manual
Nil or a ground
power switch on
panel
General
condition
Auxiliary pin
not powered
No power to busbar
with external power
connected
Incorrect
connection to
ground servicing
plug
Connect correctly
Nil
Excessive
alternator
voltage
Overvoltage
warning light
illuminated
Alternator/
regulator
fault
In accordance
with aircraft
manual
~
Overvoltage
warning
protection
Warning light
on instrument
panel
To indicate an overvoltage
condition has occurred
Electrical
Note: Always check for loose connections and broken wlfes; If any are found have them repalfed.
22 I Aviation Safety Digest 105
Overvoltage
sensor
I
Aviation Safety Digest 105 / 23
�Battery switch/alternator or generator switch
These two switch es appear in various configurations
in different aircraft. Sometimes they arc separate
and arc operated independently. O ther times they
are 'ganged' and oper ated together. This combined
switch is o ften called the Master S;vitch. I n either
case, two functions are performed by the switches.
T h e battery switch o perates the battery contactor
(or relay) and connects battery power to the bus
bar. T he alternator switch connects the alternator
field to the bus bar, thus providing the alternator
with battery power for 'field excitation'. If the
aircraft is fitted with a generator, the generator
switch connects the generator field to the voltage
regu lator to control the generator output.
Regard less of the type of a ircraft or the style of
switch es fitted, both switches must be 'on' if the
electrical system is to ope rate normally. If it
becomes necessary to turn either switch 'off in
flight, the aircr aft is in an emergency condition a nd
consideration should be give n to termination of the
flight as soon as possible.
System 1 left-zero ammeter
Ammeter
Alternator
or Generator
Bus
Bar
Battery
+
In this circuit the ammeter is measuring only the
output of the alternator. The ammeter is graduated
with zero amperes at the left hand end of the scale
and increasing in amperes to the right. With the
battery switch 'on' and the engine not running, or
with the engine running and the alternator switch
'off, the ammeter will show zero. If the engine is
started and the alternator is turned 'on', the
ammeter will then show the alternator output.
The battery discharges during starting, therefore
ammeter indication will be quite high d uring initial
battery recharging just after the engine has been
started. When the battery is fully ch arged, and the
alternator is operating, the ammeter should show a
reading slightly above the zero graduation i~ all
other electrical circuits are off. As the electncal load
is increased by turning on lights, radios, etc, the
reading will incr ease.
.
If the ammeter pointer drops tq zero in fligh t, it
probably means an alternator failure. If action in
accordance with th e pilo ts' handbook fails to restore
an ammeter indication above zero, then red uce the
electrical load to a mi nimum , as o nly the battery is
supplying electricity. Land as soon as p ossible to
have t he problem corrected.
0
System 2 centre-zero ammeter
Alternator
or Generator
Ammeter
Bus
bar
)
Discharge
0
~ ..s;~s~~
In this circuit the am meter is measuring the flow of
current to the batter y (c har ge) or from the battery
(discharge). The am meter pointer shows zero in the
ce ntre of the scale, with increasing cha rge to the
right a nd increasing discharge to the left.
With the battery switch 'on' and no a lternator
output, the a mmeter will ind icate a discha rge , i.e.
the flo w of cur ren t from the batte r y to wh atever
electrical circu its are e ner gised. With the alternator
producing power , if the electrical load is less t~ a n
the cap ability of the a lternator, the am mete r will
24 I Aviation Safety Digest 105
Check the battery regularl y for leaks, water level,
connections and security. Remember it is the 'heart'
of the electrical system.
If you start the engine with radios and other
unnecessary electrical equipment turned on you
may damage them. Large voltage fluctuations occur
when the starter is engaged and these can create
havoc in sensitive electronic circuits. Turn on
ancillary equipment after the engine is started and
after you have checked that the alternator or
generator is charging. For the same reasons tu rn
off the equipment before shutting down the engine.
Be alert for broken wires and loose connections
during your preflight inspection and ensure that
you turn off all electrical systems and the battery
switch after the engine shutdown .
Read the pilots' handbook and ensure you a re
th oroughly conversant with the correct procedures
for both normal and emergency operations. If there
is anything about which you are unsure, consult
your engineering workshop or other qu alified
orga nisations or persons for guidance •
Battery
Charge
'
Ground servicing receptacle
This is a socket where external power may be
connected to the ai rcraft electrical system. Note
carefull y the name - ground servicing receptacle.
T he main purpose of this item is to allow servicing
personnel to power the electrical system for
maintenance. Howeve1·, if a pilot is concerned about
con servin g the a ircraft battery during cold weather
star ts, a n external power source can be connected
fo r engine startin g . It is not intended to be used as
a con necting point for j umper leads from a car
battery if the aircraft battery is flat.
To conn ect external power to the aircraft all
th ree pins in the socket must be correctly powered
and this is best done with a standard NATO plug
on the external power source. If the small pin is not
powered th e ground power relay will not operate
and the external power will be unusable for engine
startin g.
Points to remember
Use of silver paper, nails, fencing wire and
ma terials other than correctly rated fuses to replace
a blown fuse is very dangerous. Without the
protection of the correct value fuse , an electrical
fire could result. Always ensure there are .spar e
fuses in the aircraft and learn how and where to
replace them.
If a particular fuse is continually blowing, there is
a fault in the circuit. Continual replacement of the
fuse only increases the danger of an electrical fire.
Report the problem on the maintenance release and
ensure it is corrected. Starting a fligh t with a 'flat'
battery could resul t in being without an y electrical
system power. If the battery is flat replace it or have
it recharged before flight.
Overvoltage protection
This safeguard is not fitted to all aircraft. For those
aircraft which are equipped with this device there
are different actio ns requ ired if a n overvoltage
condition develops. Because these actions va r y
considerably, it would be unwise to try and specify
th em he re . Refer to your pilots' handbook to
ascertain if over voltage protection is fitted and the
correct action to take if the condition arises.
\
indicate a charge , i. e. a flo w of cu rre nt to the
ba tter y. If the electrical load exceeds the output of
the alternator, the battery must also supp ly
electrica l power and the a mm eter will ind icate a
discharge. If this occurs r educe the load w h er~
possible until th e a m meter indicates a charge; 1f
unload ing the system docs not resul t in a 'charge'
indication , th e alternator has probably failed. The
appropr ia te action should be ta ken in accorda nce
with the pilots' handbook.
Fuses and circuit breakers
Th ere are man y o f these protective devices fitted to
a modern aircraft and it is in the pilot's best interest
to know th eir location. If they req uire rep lace ment
the aircraft could be stranded for the wa nt of a
little more knowledge by the pilot. All protective
devices are rated at a current which will prevent the
particular circui t cable fro m overheating a nd so
prevent smoke emission a nd subsequent fire. This
protection will only be retained if a correctly rated
fuse or circuit br eaker is used as a replacement.
From the incident files
The captain of an RPT aircraft has reported that
on several occasions at m~jor capital city airports he
has taxied his jct, at night, behind gene1·al aviation
aircraft not displaying their anti-collision lights.
When the smaller aircraft is stopped , or moving
behind another large aircraft it is extremely difficult
to see. The possible resu lts are obvious .
Pilots are reminded that aircraft, in flight or
opera ting on the manoeuv ring area of an
aerodrome at night or in conditions of poor
visibility, are required to display anti-collision
lighting in addition to navigation lights.
Unserviceable equipment is n o excuse, except when
it fails in flight. Failure to display anti-collision
lighting may result in a n unnecessar y and costly
accident•
Aviation Safety Digest 105 I 25
�Low cloud and rain - why 'have
a go'?
After a delay of about two hours because of poor weather, a PA-28 aircraft departed from Jandakot
on a VFR flight to Kalgoorlie. Only eight minutes after departure the pilot and his two r:>assengers
were killed when the aircraft crashed into high ground, out of control. The general accident area was
covered by low cloud and thick fog, with rain falling at the time.
0
The pilol and his passengers had first atte nded lhe
brie fing office at about 0730 hou rs Western
Sta ndard Time a nd obtained the relevant
meteorological forecasts. Not holding an instrum en t
raling, the pilot was restricted to flight und er the
Visual Flight Rul es and consequently fil ed a VFR
fli gh t pla n for the business trip to Kalgoorlie.
During th e briefing, the duty Flight Service
Officer had ex plained the a1·ea and term inal
forecasts , indicating that a VFR fli ght would
probably be unsuccessful. There was a band of
frontal activity about 160 km wide across the
proposed flight path with a cloud cove rage of five
to seven oktas, from 1000 feet base up to 30 OOO
feel tops. The visibi li ty was forecast to reduce to
4000 me tres in hea vy rain. This discussion on the
weather lasted about 15 minutes.
Not dissuaded in tiling a fli ght pla n , d espite the
forecast weather, th e pilot left the brie fing offi ce
with his two companions and went to the offices of
lhe aircraft o peratm·. Again atte mpts were made to
try a nd dissuade th e pilol from proceedin g with lhe
fli ght. The operator suggested that the pilot should
postpone his de parture by a da y. Appa re ntl y the
pilot beli eved that because the weathe r was better
along th e trac k, the flight could be completed.
During the next half hour th e three men had
coffee, l;>acled the aircraft and were see n moving
aro und the tarmac photographing other ai rcraft.
26 I Aviation Safety Digest 105
When it rained heavi ly, they sat in the cabin of their
a ircraft.
At 0844 hours the pilot advised the tower by
rad io, that the aircraft was taxi-in g. H e was
informed that wea th er conditions were non-VMC
towards the foot-hills a nd it was su ggested that he
call again in 10 minutes. This was done and ATC
advised the pilot tha t the cloud base had lowered
and, from the lower , it ap peared dou blful that
VMC existed over the foot-hills.
The aerodrome was closed to VFR o perations at
0907 hours and to all operations at 0919 hours.
The passage o f lhe front occurred a t 0945 hours
and a short while later weath er conditions began to
improve. Al 0959 h ours lhe aerodrome was op ened
to secto1· VFR, however , lhe sector to the south east
remained closed. The tower received another
taxi-ing call fro m the a ircraft a t I 009 hours and
again the pilot was in formed thal conditions
appea red to be unsuitable for VFR Oig h t across the
hills.
The pilot returned to the briefi ng office aboul
I 0 l 5 hours and am ended the Sa rt ime o n his fl ight
plan. He had a shon cliscussion with the FSO about
the weather and left the office wi th the intention or
'goin g and havin g a look'.
T he next contact with the pilot was at I 028 hours
when he called the tower again abou t the "·eather
a nd was advised th at visibility towarcls the hills had
)
u
improved to about eigh t kilometres. The pilot
reported that the a ircraft was laxi-ing for
Ka lgoorlie.
Because the fl ight had been p lanned through
con trolled airsp ace, Jandakot Tower contacted ATC
at Perth Airport to co-ordinale an airways
clearance, but a clearance was unavailable as the
Perth con trol zone was non-VMC. When lhe pilot
was in formed of this, he elected to proceed outside
controlled airsp ace via Mt Dale, elevation 1798 feet,
which is 41 kilomelres east of Jandakot.
At 1038 hours the aircraft was read y for take-off
but owing to precedi ng traffic did not receive
take-off clearance until six m inutes later. The pilot
reported departure at l 04 7 hours. The tower
controller obser ved the aircraft make a left turn
after taking off from run way 30 and head towards
Armadale and Mt. Dale. At that time the lops of the
hills were visible fro m the tower.
At approximate ly 1055 hours an ai rcraft was
heard in the vicinity of the hills; th e engine sound
was rising a nd falling giving the impression of high
aircraft speed. T he sound of impact followed
shortl y afterwards.
Subsequent examination of the wreckage, located at 900
feet above mean sea level, revealed that the a ircraft had
slruck the gro und at high speed in a steep nose down,
right wing down attitude. The aircraft had burst apart
and the majorily of the wreckage came to rest nearly 100
me tres from the initial impact poin t. Detailed
examination did not reveal any evidence of mechanical
malfunction which could have contributed to the
-accident.
The imp1·essio n gained by those people who came
in comact with the pilot and his passengers du ring
the mornin g was that the re was no apparent
pressure on the pilot to complete the flight on that
d ay. The trip had been delayed several times and
the business com mitm ent in Kalgoorlie was not
limited by time. The investigation did not reveal
any personal problems, either psychological or
physiological, that would have affected the
judgement of the p ilot. H e had used aircraft for
business travel a number of times in the past.
Since commencing his training in 1972 lhe pilol
had accumulated 239 hours experience. H e
completed 5.5 hours practice instrument fl ying
during his initial training but had recorded no
other instrument fl ying since then. He had flo wn
two hours in the 90 days preceding the accident.
The position where the aircraft actually
encountered I MC was not established; h owever, in
consideration of the events leading u p to the
accident; the pilot was obviously aware that the
probability of completing the flig ht in VMC was
marginal.
Did he believe that he could fl y through the
adverse weather to the expected clear area a long
way ahead ? Did he consider the front which had
j ust passed over the airport and which was moving
in a general easterly direction? Did he have a
ch ange of heart after the aircraft h ad proceeded a
few kilometres and was he attempting to get clear,
wh en he losl control of the aircraft? These
questions cannot be answered; however, on this
occasion there was no excuse fo r being 'caught out'.
The conditions were clearl y evide n t before
departure and a delay of even a few m ore hours
could have prevented this unnecessary loss of life .
Ask yourself, what would I have done under the
circumstances? Or more importantly, what will I
do if confronted with the sam e situation? •
Aviation Safety Digest 105 I 27
�I n th ose cases wh ere survivo rs are located by
surface search parties, their rescue is au tomatic if
on e of the on-scene SAR uni ts can carry ou t this
task. On the other h and, if survivors have been
located by sear chin g aircraft, the rescue operation
can be very com p lex and may requ ire d iver sio n or
despatch of helicop ters, shi ps or fixed -wing aircraft
capable of dropping flotation a n d su r vival
equipme nt. T he rescue procedures ca n become
fu rther complicated if the search operation must
continu e u ntil all sur vivors h ave been located. When
large numbers of p ersons a re involved some of the
su rvivors may not be imm edia tely located so a
syste ma tic search is con tin u ed while the rescue
operation is in progress.
Search and rescue, part 5
This is the final article in the series on the organisation of search and rescue operations in Australia.
Part 4 explained the planning of a search to ensure adequate coverage of the area, and also
described the search operation from the initial briefing of search crews through to the location of
survivors. Once their position has been establ ished, the next step is to rescue them. This article will
describe the processes of rescue planning, rescue operations and supply dropping from aircraft.
(
c
)--c
Planning the rescue
A n um ber of important factors need to be
considered in d ete r mining the method of rescue Lo
be employed a n d the type of facilities to be used .
T h e first consideration is whethe r or not the search
u nit fro m which the sur vivors have been sigh ted, or
an y other facili ty a t the scene, has been able to take
a ny effective actio n. The next consid eration is the
loca tion of the survivors in relation to the available
rescue facilities a n d the environment in which they
are situ ated . A re they on land or in the water and
wh a t is the type of terrain or the d istan ce to sh or e?
Associated with these facts is the distance of the
survivors from ope rating bases and medical
facilities. If th e SAR operation has been well
pla nned, p otential r escue facilities will have been
stra tegically located in or arou n d the search a rea
a nd will be read y to be despa tch ed as soon as
sur vivors are located.
Du r ing rescue ope rations a nd u n til it can be
p ositively prove n o th erwise, it is assum ed that
su rvivors are in need of im mediate medical aid .
Wh en they are su sp ected or known to be injured ,
the deliver y of first aid equipmen t a nd m edical
supp lies is of paramount impor tance.
A fu rthe r con sideration in plann ing a rescue is
the magnitud e o f th e situ ation . The exte nt of the
rescue effor t a nd the facilities requir ed is directly
related to the exp ected number of survivors, or, in
oth er wo rds the total nu mber of persons on board.
A lo t of resou r ces wo uld be r equired to rescue
survivors if a wide body jet, carr yi ng two or th ree
hund red p ersons, ditched at sea hund reds of
kilometres from th e coastl ine. Other factors which
influence the amo un t of aid necessar y arc terrain ,
existing a nd fo reca st weathe r, access rou tes,
distance to travel and the a m ount a nd type of
survival equipmen t available on scene.
Selecting rescue methods and facilities
Basically it can be said that the e nviro nme nt of th e
distress sce ne , the urgency of th e operation a n d th e
magnitude of the rescue effor t req u ire d '-~·ill dictate
both th e m eth ods and facilities selected . The
e nviron men t surroundin g the survivors will usu ally
be the paramo u nt influencing factor.
Some of th e r escue methods available are:
h elico pter lan din g
h elicop ter h oist pick-up
la nd party r escu e
sh ip rescue
28 I Aviation Safety Digest 105
fixed-wing aircraft landing, and
air d ropping survival equipm e nt from
fixed-wing aircraft.
T he availability of facilities capable of using
speci fic rescue method s, and thei r proximity to the
rescu e site, are prime considera tions in the ~ election
of rescue facilities.
'
T h e crews of r escu e craft will not be directed to
execu te a particular manoeuvre , technique or
meLhod th at is hazardous to the crew or cr aft unless
a thorough evaluation of the circu mstances indica tes
that acceptance of the r isk is war ranted . I n all cases
th e ca ptain has the u ltimate author ity and
resp onsibility for determining whether or not to
proceed wi th th e operation .
Let us now consider the various functions of
differe n t rescue facilities and the m anner in which
they can be deployed .
Helicopters
The ability of the helicop ter to hove r and la nd in
restricted spaces makes it a ver y important facility
for rescue operation s. The ad dition of flotaLion
equipment a lso allows it Lo la nd n ear survivors in
the sea. Some of th e limitations of helicop ters,
however, are not readil y a ppa rent. For example ,
because a h elico p ter cannot hover at h igh altitu de it
will gener ally h ave to land du ring a mou ntain
rescue. I n fact, la n dings are preferred for all
helicopter rescues b ecause heli-lifting can prese nt
hazards t o both the aircraft a nd crew as well as the
su r vivors.
Fixed-wing aircra~
The most usefu l role of fixed-wing aircraft in
rescue operations is in providing im med iate
assistance by directing su rface rescu e units to th e
scene. Orbiting the position , d ropping survival
equipmen t including a portable r adio transceiver,
oonfir ming the position , showing ligh ts o r using
other visual signals all serve to lift the morale of
su rvivors. In this way th eir immediate needs a re
provid.e d for, an d the ir position fixed.
Ships
When survivors are a co nsiderable d istance from
sh ore, rescue will norm ally be carried ou t by
long-r ange merch ant or military ships. Because of
ships' relatively slow speed s, helicopters may
so metimes be used for evacu ating survivors in need
of medical a ttention from the sh ip to a hos pital or
emerge ncy care cen tre. Rendezvous between the
ship a nd h elicopter ca n be made at appreciable
dista nces off-shore for this p urpose but once again
th ere are several li mitatio ns in this procedu re.
Unless the ship h as a helipad or is of su fficient size
to cope with a la nding o n its deck, the survivor s
would probably have to be winch ed off. Some
h elicop ters, par ticu larly military machines, have
sp ecial equipmen t for th is pu r pose.
Supply dropping
The decision as to wheth er or n o t to dro p supplies
to survivors is d ep ende nt on th e time d elay
expected be fo re the ir rescue ca n be effected . If they
are in danger du e lo exposure , d rowning, medical
or surviva l reasons su ch as Che need fo r water, then
it is necessar y to air d rop eq uipment Lo them .
Aviation Safety Digest 105 I 29
�Supplies may also have to be dropped lo augment
those carried by approaching rescue units.
Mobility of survivors on land generally makes
possible the recovery of equipment dropped a short
distance away, but a ir drops to sur vivors at sea
require a high degree of accuracy.
I n order to provide flotation and other
sustenance equipment to survivors and to ensure
their r escue, the Department of T ransport
mainta ins marine rescue facilities at 26 location s
throughout A u stralia. Major holdings of liferafts
and marine supply containers are located at Darwin,
Perth , Sydney and Townsville with smaller holdings
at several other points around the coast.
When survivors are on the ground, a land party
can usually ge t into the area fairly quickly either by
helicopter , four wheel drive vehicle or horseback.
Until a land party can get into the area, survivors
and indeed the ground party itself can be
supported by dropping food , water , m edical
supplies in a container called a Helibox. T his is
simply a cardboard box 230 mm square and
650 mm in le ngth. The top flaps are extended and
wh en rigged for use are fold ed outwards at a n
angle. When ejected from the aircraft this causes
the helibox to auto-rotate and th e rate of d escent is
reduced. In th is way fi ve to seven kg of food ,
medical equipment, water or radios can be
delivered.
Wh en the SRK is delivered to survivors in the
water, it is dropped across and upwind of the
survivors' position. As the wind effect on the
inflated liferafts is greater than on the MSC, the
SRK will d rift down on the water and form a large
'U' aro und the survivors.
DIRECTION OF
)
FLIGHT
MSC
SURVIVORS
Sea Rescue Kit
Survivors can grasp one of th e floa t ropes and
pull themselves a long and into a liferaft. By this
means survivon; can be supported ana su stained
until such time as a ship can p ick them up.
Ae rial delivery of supplies is a difficu lt and
exactin g operation, th er efore the Department
provides air traffic controllers tra ined as
dropmasters at all location s wh ere marine rescue
equipme nt is he ld. Marine multi-uni t drops are
carried out under th e direct supervision and control
of a qualified dropmaster who is resp onsible for
p re-flight briefing of aircrews, a nd safety and
security with in th e a ircraft cabin during fl ight. In
addition , two d espatchers are required for
mu lti-unit drops while only one despa tcher is
required for helibox or single-unit static line
operated drops.
Dropmasters undergo compreh ensive training in
theoretical a nd practical asp ects of supply dropping
as well as acquiring an intimate knowledge of SA R
equipmen t. Having s uccessfully completed the
theory, they must d e monstrate proficiency to a SAR
supervisor during a n actual multi-unit d rop to
'survivors' in the ocean. In order to maintain this
qualification, a d ropm aster is required to
satisfactorily comple te at least one multi-unit su pply
drop every twelve m onths.
Air traffic controllers are selected for trai ning as
dropmasters because the type of duty performed in
their day-to-day functions requires a n extensive
knowled ge of fli ght·p a tterns a nd proced ures. This
expertise is also required in the role of a
dropmaster, while their continuous availability a t al)
locations at which marine eq uipm e nt is held ,
ensures coverage through out Australia's area of
A marine rescue is effected by car rying out what
is known as a multi-unit drop of a sea rescue ki t
resp onsibility.
(SRK). T his kit consists of two I 0 or 30-man
In presenting this series of articles we aimed to
liferafts a nd three marine supply contain ers (MSC)
provide our readers with a broad insight into the
which a re each linked togethe r by LOO m of buoyant philosophy and conduct of search a nd rescue
rope so tha t on dep loyment from the a ircraft a
operations in Australia. It is possible that any
sp read of 550 m is ach ieved . The rafts are attached
m ember of the aviation community could he called
at each e nd of the kit with th e MSCs which contai n
upon to assist in the search or rescue phases and
ap proxim ately 14 kg of rations, wate r, medical
we hope that, having read these articles, you will
supplies, sign alling equipme nt a nd morale boosters
be more aware of the importance of your task in
such as p lay ing cards, in between them.
relation to the success of the overall operation •
30 I Aviation Safety Digest 105
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1979
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Department of Transport • Australia
104/1978
�Contents
Storm mission
The aim of this article, courtesy of the USAF MAC Flyer, is not to advocate the intentional transilion
of severe weather patterns. In fact, the opposite is true. This description of a weather reconnaissance
mission does, however, contain a message for all aviators.
3 Storm mission
6 A serious oversight
8 Loss of control in Piper Cheyenne
10 Food poisoning
11 Wake turbulence from heavy helicopters
12 Blrdstrikes continue
16 Boeing 747 takes off from the wrong runway
17 From the Incident files
18 Reader contributions
19 What is wrong here?
20 Non-recovery from a spin
22 In brief
24 Fresh air vent or fuel shut-off control?
Aviation Safety Digest is prepared in the Air Safety Investigation
Branch and published for the Department of Transport through
the Australian Government Publishing Service, in pursuance of
Regulation 283 of the Air Navigation Regulations. It is distributed
by the Departmf!nt of Transport free of charge to Australian licence
holders (except student pilots), registered aircraft owners, and certain other persons and organisations having a vested operational
Interest in Australian civil aviation.
Aviation Safety Digest is also available on sut>scription from the
Australian Government Publishing Service. Enquiries should be
addressed to the Assistant Director (Sales and Distribution),
Australian Government Publishing Service, P.O. Box 84, Canberra
ACT 2600. Subscriptions may also be lodged with AGPS
Bookshops in all capital cities.
Change of address:
Readers on the free distribution list should notify the Department
of Transport, P.O. Box 18390, Melbourne, Victoria 3001.
Subscribers should contact the Australian Government Publishing
Service.
© Commonwealth of Australia 1978. The contents of this
publication may not be reproduced in whole or in part, without the
written authority of the Department of Transport. Where material is
indicated to be extracted from or based on another publication, the
authority of the originator should be sought. The views expressed by
persons or bodies in articles reproduced in the Aviation Safety Digest
from other sources are not necessarily those of the Department.
26 Double harnesses for aerobatic aircraft
27 Search and rescue, part 4
30 Refuelling from drums
31 Guess who's coming to dinner?
Pilot contributions and correspondence on articles should be
addressed to the Aviation Safety Digest, Department of Transport,
P.O. Box 18390, Melbourne, Victoria 3001.
RM78/30053 Cat. No. 78 9227 7
Printed by Ruskin Press, 39 Leveson Street, North Melbourne,
Victoria.
COVER
The first Rutan Vari-Eze to be built in this country (back cover) is
an interesting variation of the results of Man's aspirations to imitate
the graceful creature on the front page.
- Vari-Eze photograph courtesy of Aircraft.
Note: Metric units are used except for airspeed and wind speed
which are given in knots; and for elevation, height and altitude
where measurements are given in feet.
•
2/Aviation Safety Digest 104
'There is always a little bit offear whenever anyone flies
into a hurrican e . . . keeping you on edge, always alert,
always cautious. T he most dangerous part of a n y storm
mission is fl ying into th e wall of thunderstorms tha t rings
th e cen tre' of a h urrican e . .. we try to find the weakest
link in the wall cloud to go through, a nd if we can't, we
must pene tra te the wall anyway.'
The com ma nder of the 53rd Weather Reconnaissance
Squ adron (WRS) - also known as the ' H urricane
Hun ters' - was talking about his job. D ifficult,
dangerous, sometimes ter rifying - b ut necessary. And
fo r years, the wea ther reconnaissance crews of the
Aerospace Resc ue a nd Recovery Service have been doing
that job successfully - and considering the hazards they
face, with a n a maz ingly good safety record.
Why do uni ts like t he 53rd pi t the relative frailty of
m a n and machine against the overwhelming ferocity of
nature's worst weather? T he simple answer is the A RRS
business : savin g li ves. Since the 1940s weather
reconnaissance units have been tracking tropical storms,
providing early warning of their movements, and buying
p riceless time fo r those in the path of a storm. T he men
who do it feel it's well worth the risk.
The tech niq ues of storm reconnaissance have changed
considerably since 1943, when M ajor J oe Duckworth
took offw.i th a navigator in the back seat of h is T -6, flew
into a hurricane off the Texas coast, then came back and
did it again with a weather observer on board. New
aircraft and equipment have m ade the job somewha t
easier and considerably more prod uctive since those early
days, but the challenge is still very much there.
J\ typ.ic~l storm mission mig h t be born in the National
H urricane Centre in Mi am i. From satellite photographs
a nd othe r weather data, meteorol"ogists locate a possible
Aviation Safety Dig est 104/ 3
�Opposite: This photograph of the eye of Hurricane Beulah was
taken by a U.S. Air Force Weather Service RB-57F aircraft when
Beulah was approximately 150 miles off Tampico, Mexico. The
photograph was taken from an altitude above 60000 feet. The
reconnaissance aircraft was from the 5Bth Weather
Reconnaissance Squadron.
storm area. The co-ordinates are relayed to the Chief
Aerial Reconnaissance Co-ordinator All Hurricanes
(CARCAH), where target times are determined. After
the details of the mission are laid on, the rest is up to
the crew.
As you might expect, a weather reconnaissance crew
_is a little different. A WC-1 30 carries two pilots, a
navigator, and an engineer - but in place of the
loadmasters, there's a weather office r and a dropsonde
. operator. The weather officer, enscon ced in a cubicle
with some very specialised and sophisticated equipment,
acts as the Mission Director. Although th e aircraft
comma nder has overall responsibility for th e aircraft and
c rew, the weather officer is the expert who must assu re
th at the technical requirements of the mission a re
completed.
On the way to th e suspected storm a rea, the Hercules
cruises a t normal en-route altitudes. Then, a bout 160
kilom etres from th e reported co-ordinates, the aircraft
descends to about 10000 fee t - the altitude a t which the
storm will be penetrated. The object now is to pene trate
to the eye of the storm - and to do this, the eye must
be located.
Since a tropical storm in the northern hemisphere is
a closed circle of winds blowing counterclockwise around
the centre, flying with the wind a t a 90 d egree angle from
the left will bring the aircraft to the eye. Working
together, the weather officer a nd navigator keep the
aircraft on course, moving steadily towards the point of
lowes t atmospheric pressure. As the aircraft pene trates
the spiral bands of rain surrounding the storm the
turbulence increases; rai n spews against the aluminium
skin w ith almost machine-gun intensity. Then, as the
Here n ears the eye wall and the n av iga tor searches for
a 'weak' spo t on radar, things really begin to get tough.
Again, the word s of the 53rd squadron command er:
'The whole thing has to be done in a very professional
m a nner a nd with precise, co-ordinated moves. Throttles
a nd yokes, airspeed, rudders, and even communication
with other crew members must be as smoo th a nd efficien t
as a ballet. Each crew member h as to know his or her
exact duties - when a nd hovv. Yo u n ever know how the
aircraft is going to react to th e raging ta ntrums of a
hurricane. You can be pinned in your seat one moment
and the very next be ha ngin g on to yo ur sca t belt an d
shoulder straps .. . Most of the time it seems as if
so meone has turned a dozen fire hoses on you . .. even
with earplugs a nd headsets a n d the noise of th e engin es,
it soun ds as if you a re inside a popco rn popper from the
noise the rai n makes.
All ofa sudd en, eve n though the few minutes we took
41Aviation Safety Digest 104
to pass through the wall cloud seem like eternity, it is
extremely quiet except for the drone of the engines. It's
so quie t, it's al most spooky. After fighti ng the turbulence,
the rain, and th e lightning, we've hit the eye of th e storm
... the sereni ty and beau ty within the centre will literally
cause your j aw to drop in awe. There you are, in the
midd le of nature's fi ercest storm, with white, almost
ice-like clouds surrounding you, towering above you to
a crystal-blue hole in a shrouded sky. Yot\ can look below
a t the churning white and emerald green wa ters that
suddenly, almost abruptly, form into a calm, almos t
rippleless surface a t the very centre of the storm. In that
one particular moment inside the eye, all of the fea r and
a n xie ty mome ntarily leave your bod y. But then you
realize tha t you have to fl y out into th e wall of
thund erstorms ... In a precious few minutes.'
Those precious minutes in the calm of the eye are busy
o nes for th e crew. While the navigator gets a fix on the
posi tion of the storm centre, the d ropsonde operator
releases a small radio transmitter; as the dropsonde falls,
slowed and stabilised by a small parach ute, it transm its
data on atmospheric conditions within the storm. The
wea ther officer then transm its th is a nd oth er data directly
to the a tional Hurricane Centre by HF radio, where
the info rmation will be used to predict the possible fu ture
track of the sto rm.
Now th e c rew m ust push the \<\IC- 130 back t hrough
th e eye wall, through the pounding turbulence and
slashing rain, un til they're clear - and then go back and
do it again from a different direction. Four penetra tions
in six hours, and then back home and into crew rest u ntil
the next call comes. And when a storm is on th e move,
that call may come ve ry soon.
D espite th e extreme h azards of this sort of flying,
MAC's stormchascrs have compiled a n enviable safe ty
record. At K eesle r AFB, the 53 WRS has been
accident-free for 11 years and over 70000 hours offl ying
time; another Keesler unit, the Air Force R eserve's 920
Weather Reconna issance G roup, has had no accidents in
its four-year history. And the 54 WRS a t Anderson AFB,
Gua m, where hurricanes are known as typhoons, has lost
only one aircraft in 15 years and more than 120000 hours;
the accident was not charged to the sq uadron.
What's the secret of this kind of perform ance, and what
can the rest of us learn from it? May be the 53rd 's
commander said it best: 'T he whole thing has to be done
in a very professional ma nner ... each crew member
has to know his or her exact d uties'.
Professionalism, discipli ne and crew co-ordination. I f
they can keep you safe in the midd le of a storm's violence,
they can keep you safe anywhere •
,
Aviation Safety Digest 10415
�A serious oversight
.
A party of five people, intending to go on a weekend
hunting trip to an island in Bass Strait, organised a
charter flight from a Victorian country airfield. The
group said they would be taking with them three hunting
dogs and a small amount of overnight camping baggage.
The operator arranged for a Senior Commercial pilot
who worked for him part time as a fl ying instructor to
make the flight. Before setting out for the airfield, the
pilot lodged an IFR category flight pla n. It was intended
that the aircraft depart a t 1300 hours and, if possible,
return to base before last light the same day.
The aircraft to be used, a Pa rtenavia P68B, was on
cross hire to another organisation. Arrangements had
been made to have il returned for th e charter but it
became unserviceable. An hour and a half after the
planned departure time, the aircraft was eventually
returned to the operator's base.
By now the passengers, who had been waiting for the
aircraft to return, were anxious to depart. They backed
up a utility truck to the aircraft, and the pilot and
passengers began transferring baggage from the truck to
the aircraft. About 80 kg was loaded in the rear baggage
compartment and the remainder of the baggage was
placed under the passenger seats. Five shot guns were
stowed loosely in the aisle and, when the passengers were
seated, the pilot positioned two dogs between the rear
seats and a third dog in th e aisle between the centre row
of seals.
The investiga tion did not establish th e pilot's
6/Aviation Safety Digest 104
knowledge of the aircraft's loading limitations beyond all
doubt. I t is possible th at he mis-interpreted the placard
which refers to a maximu m floor load intensity of '200
lbs per sq. ft.' for the rear locker, as being the maximum
permissible weight which could be carried there. !n fact
the maximum permissible load in the rear locker is
400 kg. If all the freight had been carried in the rear
locker the centre of g ravity wou ld have been better
located in the permissible range rather th an near the
forward limit - the pilot incorrectly believed he had a n
aft e.g.
When all was ready, the pilot started the engines and
taxied to the holding point. He ran up the engines to
abou t 1800 rpm and carried out a pre-take-off cockpit
check but did not sel ect the flaps to the normal take-off
setting of 15 degrees. After what seemed to the passengers
and another witness to have been a very short time, the
pilot taxied the aircraft on to the strip and almost
immediately opened both throttles to full power for a
rolling take-off.
The aircraft accelerated more slowly than the pilot
expected. On reaching the nor mal rotation speed of80
knots he attempted to raise the nose using normal back
press ure on the control column but found no response.
As he was aware of the possibility tha t the weight of the
aircaft might have been in excess of its permissible
maximum, and associating this with the slow
acceleration, he decided to leave the aircraft on the
ground to obtain a higher airspeed. In addition the
•
electric trim was used to achieve a more nose-up trim
setting. At 90 knots he again attempted to rotate the
aircraft. The force used was not excessive but more than
he thought was necessary to lift the aircraft off the
ground. The pilot then decided to abandon the ta ke-off
and, closing both throttles, applied braking. As the
aircraft approached the end of the grass strip, the pilot
realised it would over-run.
The surface of the air field outside the strip markers had
been ploughed and, though the boundary fence lay across
the aircraft's path, the pilot decided not to try and turn
on the ploughed ground while the aircraft was still
travelling at high speed. The aircraft continued straight
ahead, broke through the fence, crossed a shallow
drainage ditch and came to rest badly damaged about
130 metres beyond the end of the str ip and only a few
metres from a large tree. Finding. th e main passenger
door jammed, the pilot and the passengers scrambled
unhurt from the aircraft through the starboard
emergency exit.
The pilot held a Senior Commercial licence and had
a total of 1925 hours aeronautical experience. H e had
flown about 20 hours in the Partenavia and knew that
a flap setting of 15 degrees was normal for take-off on
this aircraft. H e had recently been flying other types of
twin-engine aircraft in which take-offs are normally
made with the flaps up, and it seems that he had not ·
mentally ' caught up' with the Partenavia. The pilot did
not use a printed check list but rel ied instead on a
standard mnemonic to do the pre-take-off checks. The
investigation did reveal that the aircraft was overloaded.
When the baggage and occupants were weighed, it was
fou nd that the loaded weight of the aircraft exceeded the
maximum permissible take-off weight by a factor of
a bout 10 per cent. This would certainly have caused the
acceleration on take-off to be sluggish and, had the flight
gone ahead as pla nned, would have resulted in a n
overweight landing at the destination.
Because the aircraft was overloaded and the pilot did
not select the flap to 15 degrees for take-off, the aircraft's
actual take-off distance in the prevailing conditions
would have been·longer than that shown on the take-off
weight chart in the approved flight manual. This chart
is based on th e use ofa flap setting of 15 degrees. In
general, the use of zero flap will increase the required
take-off distance because, without flap, the aircraft has
a higher stalling speed and, consequently, a higher
take-off safety speed. While this usually makes very little
difference to the total distance to reach a height of 50
feet, it does quile significantl y increase the g round run.
Obviously, the amount of increase depends on the
difference between the two stalling speeds. In this case,
the difference had the effect of increasing the ta ke-off
safet y speed from 79 knots with 15 degrees offlap to 90
knots without flap.
Calculations showed that, at the maximum permissible
take-off weight and in the prevailing conditions at the
time of the accident, the basic distance to a height of 50
feet with 15 degrees offlap would have been increased
by 147 metres ifflap was not used. With the aircraft
overloaded, this distance would have been further
increased by l 09 metres. Thus, the zero flap setting had
a significantly greater effect on the aircraft's ta ke-off
performance than the overweight situation. As it
happened, even when the extra dis tances are taken into
account, the total take-off distance to 50 feet could have
been accommodated within the available strip length.
After the accident it was calcula ted that the centre of
gravity of the aircraft had been virtually at the forward
limit. Heavier than normal control forces would therefore
have been required to rotate.
The development of this accident can be traced
th rough a succession of hasty a nd ill-considered decisions.
The has le of the pilot and passengers to depart, the
inadequate loading procedures and the rushed cockpit
checks all played their part in bringing th e intended
flight to a premature conclusion. I t was fortun ate that
the consequences were not more serious.
H aste and slip-shod procedures never pay off in the
long run, though at times their use might seem to bring
about short term benefits. Any pilot forced to has ten his
pre-flight preparations by circumstances outside his
control, or as a result of his own actions, should exercise
caution and start taking his time from that point
onwards •
Aviation Safety Digest 104/ 7
�Loss of control in Piper Cheyenne
(Co11de11sed f rom report issued bJ• National Tra11sporlatio11 Sefety B oard, U.S.A.)
Shortly after taking off from Capital City Airport, New Cumberland, Pennsylvania, USA, a Piper PA-31T
Cheyenne crashed in a suburban street. The aircraft was destroyed by impact forces and fire, and all
occupants - six passengers and two pilots - were killed. Another person on the ground was killed
when the blazing wreckage struck a house, demolishing the building and setting it on fire.
The aircraft was to conduct a one d ay trip, sta rtin g from
and terminating at Capital City Airport, with
intermediate landings.
At 0729 hours local time the pilots were briefed by
telephone on the en-ro ute wea ther condi tions a nd 26
min utes la ter the co-pilot called again to enquire about
the heigh t of the cloud tops. At approximately 0900 hours
the six passengers, so me carrying cameras and light
briefcases, boarded the aircraft.
At 0905 the flig ht was cleared to taxi to runway 08
a nd was passed d eparture instructions which included
' . .. maintain runway heading, vectors on cou rse' with
a cleara nce to climb to 6000 feet. This was acknowl ed ged
by the crew and, at 0921 hours, after a delay caused by
other traffic, the aircraft was cleared for take-oIT. Abou t
one minu te la ter the tower controller instructed the fl ig ht
to tra nsfer to the d epar tures frequency a nd, 30 seconds
later again, the depa rtures controller advised the airc raft
that radar contact had been established. The pilot was
instructed to turn the aircraft left on to a heading of 360
d egrees. The acknowledgement of t his instruction was the
last radio transm ission received from th e aircr aft.
According to wi tnesses who watched the take-off, the
aircraft lifted off the runwa y in a 'fl a t' a ttitude. They saw
the landing gear retract and the aircraft continue a
shallow climb on wh at seemed to be the runway heading
until it disappea red in the haze covering the airport a rea.
\ t\fi tnesses n orth and east of the d epartu re end of ru nway
08 confirmed that the a irc raft turned left after take-off,
but said it then turned right throug h a bout 270 d egrees
and the n left again through about 180 d egrees. These
witnesses also d escribed a series of sh allow climbs a nd
d escen ts during the turns. The las t witness to see the
aircraft before it crashed said tha t it appeared to come
out of the overcast in a steep descent which con tinued
to the ground. J usl before impact the airc raft
disappeared from sight behind a house a nd then he saw
the smoke a nd fire which followed the crash.
Exa mina tion of the ai rfra me, power plants and sys tems
revealed no evide nce of a ny malfunction whic h would
have been a factor in the accident.
Both pilots had acc umulated over 4000 flying ho urs,
held Airline Transport Pilot Licences a nd were qualified
flying instructors. Although both h ad considerable
experience in the piston-engine version of the Piper
PA-31 series aircraft, t hey were rela ti vely inexp erienced
in the turbo-prop PA-3 1T. Both pilots h ad completed a
ground training course on the Cheyenne a t the
m a nufac turer 's school a month b efore the acciden t,
which incl uded instruction in PA-3 l T we ight a nd
bala nce. The pilot in command, who occupied the
.right-ha nd pilot seat, had 32 hou rs to tal flight time on
BfAviation Safety Digest 104
the PA-3 1T and had also a ttended fl ig ht check-out
training. The p ilot in the left- hand seal had less tha n two
hours on the PA-3 lT a nd was schedul ed Lo underta ke
c hec k-o u t training the followi ng week. No d etermi na tion
could be m ade as to which pilot was flying the aircraft
at the time of t he acciden t.
According to witnesses who saw the crew on the
mornin g of the acciden t, a PA-31 T Weight a nd Balance
Visual Plo tter was used to determ ine the load ing of th e
aircraft before fl ight. T he plotter, wh ic h is supplied wi th
the aircraft, is an accep ted means to d etermine this
informa tion and consists of an im prin ted transparen t face
behind which is a movable slide . By matching
informa tion on the face of t he plotter with information
o n the slide, weigh t a nd balance information can be
ob tained for specific aircraft loadi ng si tuations.
Instructio ns for use and gener al loading
recommendations are given on the reverse side of the
plotter. Step th ree of the instructions contains a caution
th at the proper portion of the plot ter must be used for
either aft or forward facing t hird a nd fourth passenger
seats. T his aircraft had aft facing third and fou rth seats
a nd when other pilots employed by the opera tor were
as ked to solve problems using the plotter, they invaria bly
made computa tio n errors involving these seat positions.
L oading recom mendation nu mber five sta tes: 'When
carrying eight occup ants, front compartmen t must be
loaded to bring e.g. within 138.00 in. (3505 mm)
rea rwa rd limit. F uel must be reduced ·to keep total
weighc within 9000 lb li mit (4082 kg). Loca te heaviest
occupants forward '.
According to witnesses who saw the a ircraft being
load ed , no baggage was placed in the fro nt compartment
and n o evidence was fou nd at the accident site to indica te
tha t a ny baggage had been loaded in t ha t compa rtment.
The scat locatio n ofo nly on e passenger was positively
es tablish ed. U sing actual weigh ts of crew and passengers
ta ken from recent docume nts the weight a nd e.g. position
of the aircraft was calculated for a conservative loading
case in which the heaviest p assengers were seated fo rward
in accorda n ce with the prescribed loading instructions .
The exact weig ht of th e items carried on board by the
passe ngers was unknown, but assum ing th at 23 kg of such
luggage had been stowed in the rear luggage
compart ment, the calculations showed that the aircraft
was near the maximum take-off weigh t, and the e.g.
would have been 3558 m m aft of the d a tum point, or
53 mm outside the certifica ted rear limit. I t was learned
however, that some of the p asse ngers on board the
aircraft usually preferred to sit in certain seats. Their
p references d id n·ot place the heaviest passe ngers fo rward
in the cabin bu t, rathe r, res ulted in the heaviest loads
•
being towards th e back. Under these conditions, and
with 23 kg of baggage in the rear compartment, the e.g.
woul d have been 3586 mm aft of the datum, or 81 mm
outside the rear limit.
A t t he time of the accident, the stability and control
characteristics of th e Cheyenne at e.g . locations so far
behind the aft limit were not known. Arrangements were
made for a ser ies ofAight tests to evaluate the
longitudinal flying q ualities of the Cheyenne at various
e.g. locations. T hese were conducted using a specially
equi pped B-26 test a ircraft in which the characteristics
governing aircraft sta bility and pilot control forces could
be varied electronically. This variable stability system
was progra m med to simulate the pitch responses and the
elevator control forces of the Cheyenne at the speed and
engi ne power used for normal climb.
T hree p ilots, none of whom had significant experience
in the C heyen ne, took p art in the evaluation. In addition,
the simulation was sam pled by a qualified Cheyenne
p ilo t from Piper Aircraft Corporation and engineering
pilots fro m another source. The evaluation pilots were
asked to fl y a flig h t profile similar to that on which the
acciden t occurred . Realistic radio clearances and
peripheral tasks were included in an attempt to simulate
a normal distraction level.
Summa rizing the p ilot's comments relative to the
evalua tion flig ht at the e.g. position considered to have
existed at the time of th e accident, namely 81 mm aft of
the rear limi t, the NT SB Report states:
'C haracteristics
- e.g. aft of stick-fixed and stick-free neutral points:
position and force gradients with changes in speed
from trim airspeed are unstable
- two seconds to double the amplitude of each
divergency with stick fixed
- e.g. at stick-free manoeuvre point: stick force per 'g'
1s zero.
All th e pilots com mented th at the aircraft was unstable
and oversensitive in pitch. The aircraft was difficult to
trim, tended to wander off in pitch attitude and airspeed
with a ny pilot ina ttention and corrections were difficult
to make. T his e.g. location was considered unsafe for
normal operations by all the evaluation pilots.
Performance was poor with large, uncomfortable
excursions from the d esired pitch attitude and speed.
Excursions of ± 314 g in normal acceleration and - 20 kn
up to+ 40 kn of airsp eed deviations from trim airspeed
were common.
At this e.g., the a ircraft is essentially at the stick-free
manoeuvre point where the aircraft has neutral
manoeuvring stability. At trim speed, the stick force per
g in accelera ted flight is zero. Pilot control feel in
manoeuvres is typically poor and is reversed for
manoeuvres off the trim speed. One pilot commented
t hat in IFR weather conditions he "could imagine losing
control of the ai rcraft".'
In respect of the accident aircraft, the flight tests
ind icated that it was both statically and dynamically
unstable. A stable aircraft, when disturbed from its
trimmed flight attitude, will tend to return to its original
a ttitude without any corrective action by the pilot. An
unstable aircraft with an extreme aft e.g. will, on the
other hand, con tinue to diverge in the direction of the
ini tial d is turban ce u ntil the pilot reacts to stop the
motion. T he stick forces which the pilot would have
experienced in his attempt to control the aircraft would
have d iffered from the normal in such a manner that his
ability to control the aircraft would have been impaired.
While pilot inputs to initiate a manoeuvre or to change
airspeed would have been normal, stick force-airspeed
gradients would have been reversed; that is, to stabilize
the aircraft at a reduced airspeed would probably have
required a push force instead of the normal puH force,
and to stabilize it at an increased airspeed would have
probably required a p ull force instead of the normal push
force . Moreover, the manoeuvring stick force-load factor
gradient would have been essentially zero, which would
have resulted in poor aircraft control 'feel'. As a result,
over-control in pitch to stop any divergence would have
proba b ly occurred and the resulting p ilot-induced
oscillation could have eventually caused complete loss of
control.
Although the pilot, under relatively favourable
conditions, could have adjusted his control inputs to
maintain a steady flight path, the attention and workload
required to do so might have been compromised by the
performance of other necessary flight duties in an IF R
environment. Any slight inattention to controlling the
aircraft would have q uickly precipitated a divergence,
which would have increased rapidly as airspeed reduced.
The' flight tests showed that with a e.g. position 81 mm
aft of the permissible rear limit, the time taken for the
amplitude of the pitch d ivergence to double was about
two seconds.
ln this accident, since the manoeuvring stick force
gradie n t was zero, overcontrol of the aircraft or a
pilot-induced oscillation would have resulted from a
divergence since the pilot would have found it difficult
to avoid unwanted inputs. Consequently, the probability
of recovery after the divergence was recognized would
have been problematical. T he pilot probably was not
able to trim the aircraft in the short time following
take-off. H e may have merely modulated the divergence
of the aircraft for a brief time before matters became
un controllable, by periodically pushing and pulling on
the control wheel in an attempt to set pitch attitude.
O n this take-off, the crew probably ignored the
mislead ing of their aircraft. T hough they may have been
aware that certain degraded flight characteristics should
be expected with an extreme aft e.g., the sudden
departure from normal aircraft performance would have,
in this case, caught them unawares. The extra workload
imposed by the instrument meteorological conditions
with no visible horizon, the limited experience of both
pilots in this aircraft, and a turn shortly after take-off
would have added to the confusion caused by the
aircraft's erratic deviations from expected standard climb
characteristics. The Safety Board concluded that,
because of the confusion brought about by these
conditions, the pilots allowed the aircraft to diverge from
the normal departure profile and the n ovcrcontrolled the
aircraft into an unsafe condition during recovery
attem p ts. T his overco ntrol then increased in amplitude
until the aircraft crashed.
T he National T ransportation Safety Board determined
that the probable cause of the accident was the flight
crew's failure to ensure that the aircraft was loaded
properly and that its centre of gravity was within
certificated limits. As a result, the aircraft's control
characteristics were degraded significantly by a centre of
gravity p!Jsition well aft of the certificated limits. This
imbalance led to the pilot's inability to control a
longitudinally unstable aircraft during a climbing turn
in instrument meteorological conditions •
Aviation Safety Digest 104/ 9
�Food poisoning
The pilot of a Cessna 206 was returning in the late
afternoon from a round robin flight with a medical team
in the Northern Territory. Approaching 50 km from
destination he started to feel bilious and actually began
vomiting while in the circuit. This lasted for a minute
or two, the front seat passenger giving what assistance
he could. The pilot then made a normal landing.
The day's flying had commenced at 0630 hours and
during the morning the aircraft had spent a considerable
time on the ground at various locations. Ground
temperature was approximately 30°C and at lunchtime
the pilot had noticed that the food which he had carried
in a plastic container in the cockpit was quite warm. The
meal consisted of cold meat and vegetables left over from
a baked dinner the previous night.
After the incident, the doctor in the medical team
checked the pilot's pulse, heart and blood pressure but
could find nothing wrong. The doctor concluded that the
illness was caused by toxic contamination of the food the
pilot had eaten earlier in the day.
*
*
*
The pilot of a P A3 I departed from Adelaide for
Melbourne at 2015 hours. At 2040 hours he advised over
Lake Albert that he felt ill and was returning to Adelaide
where a normallanding was made.
The pilot said that on the evening prior to the flight
he had eaten at a restaurant with friends. He woke up
the following morning feeling a little queasy and the
feeling persisted all day. He ate lunch and dinner and
felt neither worse nor better when he took off. However
in flight _he became suddenly and violently ill and broke
out in a cold sweat. T he pilot stated that had this
condition continued he doubted his ability to have
landed safely, but fortunately the attack had passed by
the time he returned to Adelaide.
Several of the people who had ea ten with the pilot the
previous evening also experienced varying degrees of
illness over the next three days. So far as the pilot could
remember they had all started their meal with oysters.
Remember the oyster scare?
*
*
*
T here are a number of different organisms which can
cause food poisoning and the time of onset of symptoms
after eating contaminated food can range from two to
48 hours depending on the particular organism
responsible.
The most common type of food poisoning is due to the
staphylococcus bacillus, which produces an enterotoxin
which is extremely distressful to the human intestine.
Although fatalities are rar e, incapacitation may cause a
pilot to lose control of his aircraft.
Foods which are most subj ect to staphylococcus bacteria
infestation are custards, cream soups and sauces, cream
pastries, cake fillings, and mayonnaise. In summertime
it is frequently not possible to keep these foods under
proper refrigeration at a ll times. A few hours of exposure
at room temperatures or higher is sufficient to permit a
toxic condition to d evelop. Symptoms usually appear
from two to six hours after eating. These can occur in
various combinations of nausea, faintness, vomiting,
headache, abdominal cramps and diarrhoea . The victim
10/Aviation Safety Digest 104
may suffer severe collapse and prostration, although
recovery, when it begins, is usually quite rapid.
Salmonella bacteria, another common cause of food
poisoning, prefer the leaner foods , such as improperly
cooked chicken, turkey, salmon, eggs, ham, etc. Unless
meat is thoroughly cooked salmonella may be only
temporarily weakened by exposure to the heat, and may
regain their vigor and proliferate in a warm, moist
environment such as under a waterproof wrapper in a
warm cockpit. Symptoms, similar to those associated
with staphylococcus, are slower to appear; the first signs of
distress may occur 12 to 24 hours after eating
contaminated meat.
A third form of bacterial food poisoning, botulism, is
rarely encountered, which is all to the good, since
mortality may be as high as 65 percent. Botulism occurs
mainly from eating improperly canned or preserved
non-acid foods. Bulged or swollen cans, or the
appearance of spoilage in glass containers, discoloration
or pronounced odour are danger signals. Such food
containers should be discarded. ' Staph' and salmonella,
incidentally, give no warning whatever as regards taste
or appearance.
Victims of suspected food poisoning need professional
medical attention; in severe cases acid imbalance,
prostration or shock may take place. Complete recovery
may take several days; fl ying during the recovery period
is not recommended. The anti-spasmodics and sedatives
used in controlling the ailment could seriously interfere
with pilot performance.
The pilot operating in isolated areas during the
summer months is particularly vulnerable to food
poisoning. Hot humid days provide the ideal climate for
rapid growth of bacteria and the pilot may be forced to
eat at a remote stopover point where he has no
knowledge of how the food was prepared or under what
conditions it was stored.
The introduction of bacteria to food does not itself
represent a hazard. The danger arises when
contaminated food is subjected to improper ha ndling,
thus allowing the bacteria present to proliferate. In
general, bacteria will multiply at temperatures between
10°C and 60°C , so that the period of time during which
risky foods are held in this temperature range should be
minimised. Many cases of food poisoning outbreaks have
been recorded where the food responsible has been kept
warm or reheated, providing excellent growth conditions
for the bacteria already present.
To reduce the threat of food poisoning, the pilot should
therefore endeavour to eat only fresh foods, and if
consuming hot meals, to eat only those dishes which have
been thoroughly cooked at a sufficiently high
temperature just prior to consumption. If this is not
possible and it is necessary to eat reheated dishes, these
should have been initially well cooked and then
immediately transferred to a refrigerator, so that the
minimum time is spent in the danger temperature range
of 10°C to 60°C.
Where possible, the airline p recautionary measure of
never serving both pilots the same meal could well be
adopted in general aviation•
Wake turbulence from heavy
helicopters
..
•
·'
In a north-westerly wind of five to ten knots, a Sikorsky
S-61N helicopter had made an approach to runway 35
and subsequently had moved off to the west side of the
runway to allow a Chipmunk to land. The helicopter was
hovering at an estimated height of 10-20 feet about 100
metres fro m the runway edge when the Chipmunk, 100
feet above the r un way and over the centreline,
experienced turbulence of sufficient severity to make
control d ifficul t. I t was concluded that the C hipmunk
was affected by the helicopter's downwash being
deflected obliq uely from the surface by the wind.
We are all aware of the hazards created by fixed-wing
aircraft wake turbulence and the separation standards
that have been recommended. When we think of
helicopters however, normally we think only of the rotor
wash hazard created by a hovering helicopter. But
during forward flight, the rotor wash also creates wake
turbulence and there have been several cases overseas
where helicopter wake t urbulence has caused an accident.
In one case, a light aeroplane turned on to final
approach about a kilometre behind a large helicopter.
As the ligh t aeroplane neared the runway, it pitched
down abruptly and crashed shor t of the runway. The
pilot claimed that he had been caught in the landing
helicopter's wake turbulence.
Several years ago the U S Army made a study to
determine helicopter rotor wash velocities. T hey fou nd
that rotor wash velocity was 29 knots or 15 metres per
second for medium helicopters, 51 knots or 26 metres per
second fo r la rge size helicopters, and fo r very large
helicopters the velocity was as high as 98 knots or 50
metres per second. T hese velocities arc present at less
than 30 metres from a low hovering a ircraft and,
naturally, will be greatly reduced further away from the
aircraft and in forward flight. The wake turbulence that
results from such velocities should not pose a problem for
large fixed-wing aircraft but for light aeroplanes and
small helicopters it can be a serious hazard.
Generally, an approach should never be flown below
a preceding helicopter' s approach path because of the
downward deflection of t he wake turbulence/ downwash.
The d isplacement effect of any wind on the turbulent
wake should also be considered.
One overseas Aviation Safety Committee has
recommended one minute separation between a heavy
helicopter and any following landing aircraft, but we
believe that this may not be adequate to cover all
circumstances. Until more definitive infor mation is
available and appropriate standards are developed, it is
recommended that extreme care be taken in making
approaches behind helicopters or when crossing
helicopter approach paths.
General avia tion pilots operating regula rly in northern
Queensland and north western Australia will be aware
that large helicopters such as Wessex and S6l's are also
flying in these areas. It should be noted however, that
these aircraft occasionally fly to the capital cities and
could presen t a hazard at primar y and secondary
aerodromes. Additional large helicop ters such as the
C hinook, Sea K ing and Wessex are also operated by the
military and could be encountered at any locality.
Pilots of light aircraft and small helicopters, and air
traffic coq.trollers, should be aware of the potential
hazard •
(Adapted from an article in the Flight Safety Bulletin.)
Aviation Safety Digest 104111
�Birdstrikes continue
In Issue 102 of the Digest we announced a campaign aimed at reducing the occurrence of bird strikes.
The Department is prepared to extend throughout the country the kind of bird control techniques which
have been used successfully at Sydney Airport. As a first stage in this project, information is required
from a local level on the species of birds which are causing trouble and their behaviour patterns. Pilots
are therefore invited to report immediately all birdstrikes. Special forms have been printed for this
purpose and are available at flight briefing offices.
In order to illustrate the extent of the problem presented to aviation by the bird population, we have
decided to include in this issue a number of recent accounts of birdstrikes. It can be seen that light
aircraft are as vulnerable as RPT jets.
O n fi nal approach to Kowanyama, Qld, the captain
of a DC3 observed a n umber of.hawks over the end of
th e runway, apparently a common sight on a warm
au tumn morn ing. As the aircraft touched down, a
n umber of birds took fligh t and one collided with the
right hand windscreen which shattered, showering the
pilots with glass sl ivers. The landing was completed
normally and one of the p ilots received medical aid for
a minor c ut above his eye.
On descent below 5000 feet, near Wonthaggi, Victoria,
the left wi ng of a Beech 36 struck a large, unidentified
bird . Aircraft con trol was not aftccted and the flight was
terminated at Moorabbin without further incident. The
leading edge of th e left wing was buckled near the
wing root.
•
While m ustering along the Nullagine river in W estern
A ustralia, the pilot of a Cessna 172 was assisting some
stockmen to move cattle ou t of the river when the aircraft's
left wing h it a duck. D amage was confined to a dented
leading edge, abou t half a metre from the wing root.
A Beech 36 a ircraft a r rived in the circuit area of a
Queensland station a t about 181 5 EST on Boxing D ay.
T he pilot saw some horses on the strip and commenced
a low pass to move them and to alert the station staff.
After passing the horses at about 60 feet AG L and 130
knots the pilot looked a head and saw a flock of geese.
Avoidin g action was not possible and as the aircraft
passed t hrough th e flock, the pilot heard two loud
impacts fro m the tail section. Control of the aircraft
checked ou t normally, and a circuit and landing were
made withou t furth er incident.
12/Aviation Safety Digest 104
After landing, the pilot found part of a bird em bedded
in the fin with b uckling back as far as the spar . The right
hand stabiliser was similarly buckled.
Climbing through 6000 feet after departing Port
Hedland, W.A., a Fokker F28 struck an uninden t1fied
bird. After the next scheduled landing the crew found
damage near the left wing root. The aircraft was ferried
to Perth for repair.
A Boeing 747 was landing at D arwin in the afternoon
when a number of black kites rose from the runway in
front of the aircraft. After shutting down, the crew found
that a right inboard wing flap was damaged, requiring
skin repairs. Several dead birds were removed from the
runway.
While cruising at 2000 feet en-route Mitchell River
mission to Edward R iver mission in Queensland, a Beech
Queenair struck a hawk which was apparently riding a
thermal and ascending in front of the aircraft. The right
wing leading edge was dented and the aircraft returned
to its departure point.
I t was early afternoon in late summer when a Learjet
24D was taking off from Essendon airport with only two
pilots on board. The aircraft had reached about 110
knots with a Vr of 130 knots, when the captain saw a
white 'fl ash', the co-pilot called out 'a bird', there was
a 'thump' and the left engine stopped. The aircraft
veered left but the pilot corrected with heavy rudder and
abandoned the ta ke-off, stopping the aircraft on the
runway using heavy braking and the drag chu te. After
shutdown the left engine was found to have the first two
s tages of the compressor damaged (see photo). The bird
was identified as a banded plover.
Aviation Safety Digest 104/ 13
�1
..
The pilot of a PA-28-180 had llight planned from
Mildura to Broken Hill, via Menindee, below 5000 feet,
so that his passengers could photograph the area.
Approaching M enindee, he descend ed to I OOO feet
a ltitude. After a short while as he was preparing to climb
the aircraft back to 3000 feet, the pilot noticed some large
birds ahead. H e delayed the climb to avoid them but one
of the birds d ived towards the aircraft. The pilot tried
to avoid the bird by di ving also, but they collided. The
bird hit the top of the windscreen and the cabin roof,
pieces of broken perspex entered the aircraft and the
structure supporting the trim controls was distorted.
After checking that there were no control difficulties, the
pilot landed at a nearby station strip. It was concluded
that the bird was prol::>ably a pelican.
A Piper Pawnee agricultural aircraft was engaged in
spraying a crop of linseed at a western Victorian
property. During the pull up at the eµd of a spraying
run, the pilot saw two large eagles approaching from t he
port bow. They appeared to be a ttacking the aircraft b ut
the p ilot was committed to the procedure turn because
of some trees and could not take avoiding action. The
left wing of the aircraft struck t he leading eagle an d was
extensively damaged. The pilot dumped the remaining
spray and immedia tely landed at the nearby agricultural
14/ Aviation Safety Digest 104
strip. The eagle (see photos) was fatally injured in the
collision!
A Piper PA-28-140 was taking off from runway 23 a t
Walge tt on a May afternoon and just after becoming
ai rborne it flew into a flock of gala hs. There were
num erous birdstrikes but operations appeared to be
normal until the aircraft crossed the upwind end of th e
runway when the engine lost power. A forced landing
was made straight ahead a nd the aircraft finished up
substan tially d amaged on a road way outside the
aerodrome boundary. Fortunately neither of the pilots
was injured.
Following the accident 22 dead galah s were found on
the runway!
Subsequent investiga tion revealed that the fuel filter
drain had suffered a strike and the bowl became loose
allowing fuel to leak o ut. During the investiga tion the
engine ran normally after the filter bowl had
been tightened.
t
l
Your continued co-operation in reporting attacks
by these feathered 'kamikazes' is imperative if the
problem is to be overcome.
Any suggestions for improvements in the
reporting system itself would be welcome •
Aviation Safety Digest 104/15
�Boeing 747 takes off from the
wrong runway
At Australian airports, air traffic control is required to select preferred runways in consideration of the
meteorological conditions and local requirements including noise abatement. At all times, however, the
ultimate decision as to the suitability of the nominated runway with regard to length, crosswind or
any other safety reason, rests with the pilot-in-command.
It was a warm, summer afternoon in M elbourne when
the ju mbo jet arrived from Sydney. The next sector was
direct to Singapore and, following a crew change, 381
passengers boarded the aircraft.
Scheduled departure time was 1500 hours Eastern
Summer Time (ESuT) and at 1507 hours the aircraft was
pushed back from its parking bay at the international
terminal. Air traffic control cleared the aircraft to depart
from runway 27, climbing to flight level 310.
At 1521 hours the aircraft was given clearance for an
immediate take-off from runway 27 and it commenced
rolling. All appeared normal until approaching decision
speed when it became obvious to the crew, from the
limited runway remaining, that the aircraft was using a
runway of inadequate length for this take-off.
The captain took over the controls from the first officer
and initiated rotation. The heavily laden aircraft lifted
off about 10 kno ts below the ta rget rotation speed but
not before several of the 16 main wheels had rolled
through the grass for nearly 50 me tres beyond the end
of the sealed stopway.
Witnesses to the ta ke-off, some of them close to the
western end of the runway, repor ted that rotation did
not begin until nea ring the upwind threshold. Shortly
after the 74 7 did rotate there were clouds of dust and
g rass cuttings b lown up by jet blas t. The gable ma rkers
a t the end of the fligh t strip were blown flat and several
hay b ales in the over-run a rea were destroyed .
Subsequent inspection of the area revealed tyre m arks
visible over the threshold markings a nd sealed stopway,
continuing into gouges up to 46 metres long and three
centimetres d eep in the over-run. There was no evidence
to suggest that the aircraft sustained d amage.
ATC advised the crew of the incident a nd, as there
were no in-fligh t abnormalities, the flight continued to
Singapore. After landing, an examination of the aircraft
confirmed that it h ad not sustained a ny d amage.
How did this situation arise?
Meteorological information
At the time of the occurrence the Automatic Terminal
Information Service (A TIS) was reporting th e following
conditions,' ... informa tion Quebec, wind 290 degrees,
15 to 25 knots, QNH 1004, tem pe rature 28, clo ud one
okta at four thousand'. I mmediately following the
incident the actual wind, as indicated by the a nemometer
in the tower, was recorded as 290 d egrees 18 knots. This
gave headwind compon en ts of+ 16 knots for runway 27
a nd+ 11 knots for runway 34.
Aircraft loading
. The maximum take-off weight (MTOW) wit h regard to
16/Aviation Safety Digest 104
structural limitations was 351 533 kg. This aircraft was
fitted with a fifth engine ferry pod a ttached to the
underside of the left wing be tween the inboard engine
and the fuselage, which red uced th e M T OW to
342 462 kg, as well as imposing a take-off performance
penalty.
There were 126 OOO kg of fuel and 381 passengers on
board bringing the calculated brakes release weigh t
(B RW) to 336 887 kg. Take-off speeds cqmputed for the
flight were V1 (decision sp eed) 161 kno ts, V r (rotation
speed) 17 1 knots and V2 (take-offsafety speed ) 177 knots.
Airport details
The lengths of runways 09/27 and 16/34 at Melbourne
were 2286 and 3657 metres respectively. There were 60
metre sealed stopways at the ends of t he ru nways and
all surfaces were dry a nd in good con dition.
Beyond the weste rn end of the runway 27 stopway
ther e were sever al hundred metres of fir m, level ground
covered in recently mown grass and baled hay. Past the
airport bounda ry fe nce the terrain fell away sharply into
a rocky gorge.
Flight recorder
Analysis of the D igital Flight D ata Recorder inform ation
indicated tha t ro tation commenced 112 metres from the·
western end of runway 27. The comp uted Vr speed was
achieved when th e aircraft had been airborne for about
350 metres. I t was calculated that Vr could not have
been achieved in the take-off run available.
Take-off performance
From the specific performanc~ c harts in the aircraft flight
manual the follo wing weigh ts were obtained fo r the given
conditionsRunway 27
T emperature 28°C
Wind component+ 16 knots
F lap 20 degrees (field leng th limited)
Fifth engine ferry pod decremen t- 5830 kg.
M aximum BRW 305 650 kg.
Runway 34
Temperature 28°C
Wind component+ 11 knots
Flap 10 d egrees (field length limited)
Fifth engine ferry pod decrement - 8910 kg .
M aximum BRW 336 610 kg.
As the load sheet brakes release weight was 336 887 kg,
the aircraft was more than 31 OOO kg a bove the maximum
BRW for runway 27 a nd also slightly above the BRW
for take-off from the most suitable runway.
Flight crew information
All fligh t crew members held a ppropriate licences
endorsed fo r Boeing 747 aircraft and were experienced
on the type.
Take-off documentation
The take-off data card, which was used to display the
appropriate in forma tion to the pilots during the take-off
phase, was of the type provided by the aircraft
manufacture r. T he re was no provision on the card to
anno tate the runway or meteorological conditions for
which th e take-off performance was calculated. For this
take off, the da ta was extracted from the Q uick Reference
H andbook, not the specific take-off charts in the Flight
Manual in accordance with company procedures.
Reference to the a ppropriate flight manual charts should
have alerted the crew that no runway would be suitable
for ta ke-off a t the load sheetBRW.
Selection of the take-off direction
Air traffic control aspects
At the time of this incident the average crosswind on
ru nway 34 was 16 knots with gusts to 20 knots. T his
runway was therefore unsuitable for ATC to nominate
as the preferred runway. AIP T MA noise abatement
procedures, Melbourne, states that runway 27 and 34
have equal first preference with runway 16 as second
preference. The selection of runway 27 as the preferred
runway was therefore in accordance with the appropriate
instructions.
AIP RAC/ OPS states that ATC will nominate a
runway which appears to be most suitable b ut adds that
'the pilot-in-command shall ensure that there is sufficient
length of run .. .'. lfthe nominated runway is not
suitabl e it follows that the pilot shall advise ATC and
request a more suitable runway.
Flight crew aspects
It is normal practice for the flight engineer to complete
the take-off data card after the first officer obtains the
ATIS information. This apparently occurred in th is
instance and the captain was informed that runway 27
was in use. Neither pilot however, verified that at the
load sheetBRW, the nominated runway was acceptable.
If reference had been made to the specific take-off charts
in the flight manual then it would have become obvious
t hat runway 27 was of inadequate length for this take-off
Why did this incident happen?
Probably the combination of a num ber of factors, each
of limited significance in itself. The crew could not offer
any positive reason but it was suggested that the late
arrival of the aircraft on the previous sector and a minor
problem with the flight plan could have contributed. T he
repeated reference by ATC to the nominated runway
certainly was of significance and the crew may have been
' conditioned' into acceptance.
Could it have been avoiaed?
T hat the aircraft was on a direct flight to Singapore with
a nearl y full passenger load and the aerodrome
temperature at ISA+ 13 should have alerted the crew
to the likelihood of a critical take-off. Recognition of the
situation should then have lead them to ensuring the
adequacy of the nominated runway.
Remember, if you have any concern about using
the runway nominated by ATC, and your concern
could be alleviated by the u se of another runway,
advise the tower of your requirements •
From the incident files
Digest 100 con tained a detailed report concerning the
loss of control of a Fokker Friendship aircraft when the
gust lock was engaged in flight. T he investigation
es tablished th at before take-off the flight manual had
been incorrectly stowed. In flight, when the first officer
moved his seat, t he flight manual was pushed back
causing· the gust lock to engage. The article concluded
by suggesting .th a t 'the likelihood of such a seq uence of
events is so rare ... ', however, since that article appeared
a very ~imilar incident was disclosed via the Incident
Reporting System.
Briefly, it was reported that an F27 was on final
approach to a NSW aerodrome with full fla p selected
when, for no apparent reason, the flap retracted to the
U P position. A missed approach was conducted a nd
investigation by the flight crew revealed that the flap
'emergen cy up ' selector switch was in the UP position.
It transpired th a t the first officer, while adjusting his seat,
had ca used a publication resting on the top of his
navigation bag to operate the switch .
Fortuna tely, th e outcome on this occasion was much
less dramatic than the occurrence involving the gust lock.
In other circumstances, such as on late final approach,
the results could have been disastrous. The incident
prompted the circulation to the industry of a reminder
on the essentials of good housekeeping in aircraft
cockpits. The old adage relating cleanliness and godliness
can be equally important to a pilot in an aircraft as to
a surgeon in a hospital. The final effect, if the rule is not
adhered to, can be the same.
Remember that loose objects in the cockpit are a
serious threat to your maintaining control of an aircraft.
T he instrument panel coaming is not the place to store
maps and charts, especially during take-offs and
landings, and the floor is not the proper stowage for flight
manuals, etc. If you carry a navigation bag use it
correctly, put all publications not being used into the
bag; if not, use proper stowage points to keep
publications and documents out of the way. If these are
not provided, arrange to h ave them fitted. The rules
apply equally to general aviation and r egular public
transport a ircraft •
Aviation Safety Digest 104/ 17
�Reader contributions
Several times over the years in reviewing 'Below VMC'
accidents the Digest has specula ted whether the many
examples published were having an y effect on pilots in
educating them to be aware of the da ngers, and instilling
the correct frame of mind to make timely planning and
in-flight d ecisions to avoid this type of accident. I am
confident I speak for man y pilots when I say that I a m
sure such education does have its effect, and is
unquestionably worthwhile. A recent personal
experience might serve to illustrate the point.
I had planned a VFR flight from Moorabbin to
W arrna mbool via the wes tern light aircraft lane and
Bacchus Marsh, returning via Ocean Grove and the
coastal route to Moor abbin. The weather forecast, while
indicating some expected shower activity, was by no
means unfavourable and indeed the weat her east of
Bacchus Marsh was virtually CA VOK. H owever, shortly
after passing Bacchus Marsh on a direct track for
Warrnambool, the weather began to deteriorate rapidly.
The cloud began to thicken and the base lowered from
2500 feet a bove mean sea level to 2000 feet and then
down to 1500 feet. There were frequent rain showers and
I was forced to divert several times to miss particularly
heavy concentra tions. It was at this point that I am s ure
the Digest paid off.
Your very accurate assessment of the kind of pressu res
a nd thinking which operate on a pilot to make him 'press
on' cam e immediately to mind a nd I realised those same
pressures were exerting their infl uence on me:
' Maybe this stuff is only local. '
'I know there is no high ground on this track so what's
the harm in sneaking down a bit lower?'
'I will look a bit of a dummy ifl go back and try to
expla in to the guys at Moorabbin how bad the weather
is, when one remembers the beautiful conditions there.'
' Why d on't I call Flight Service and reques t actual
weather for W arrnambool, and if t he conditions sound
okay i t is worth the risk to go on .'
Then the Digest came back again. W as there not a
Com anche that finished up in a lake down this way after
pressing o n, reassured by a favou ra ble termin al fo recast
for Warrna mbool?
And wait a minute ! With all this ducking and weaving
around showers and the current poor visibility I am not
at all sure tha t I can pinpoint my position. So how the
hell can I be sure of where the high ground is?
All right, pilot in command! Do VMC co nditions exist
or don' t they? Answor: Yes, bu t very marginal ind eed,
with no sig n of improvement, in fact the trend is opposite.
And W arrnambool is still some 80 nm away. When I did
pick up the mike it was to say 'M elbourne, (callsign ),
unable p roceed in VMC, returning to Moorabbin via
Bacchus Marsh' .
Did I make the right decision? W as I overcautious?
One will never know wi th an y cer tainty. I la ter heard
other a ircraft pressing on in the same area, others were
dive rting, etc. On reflection I a m satisfied the correct
decision was made. I am certain I was getting into a
sit ua tion which my 200 hours experience could well have
found beyond its capabilities to handle.
T he point of course in relation to the Digest's concern
expressed in the opening paragraph of this letter is tha t
18/Aviation Safety Digest 104
you only hear and read of the Digest's failure in its
campaign aga inst this type of accident. I hope this story
convinces you that the Digest does have its successes
too.
I read with in terest your r eport in Aviation Safety Digest
JOO, entitled ' The Pr ice oflnexpe rience' , o n the tragic
accident which occurred when a Cessna 172 flown by a
private pilot a ttempted to land on an agricultural
airstrip. Working as an agricultural pilot I have spread
a pproximately 400 tonnes of super phos pha te from th e
airstrip featured.
As the investigation team would be awai·e, the number
of sharp ridges and spurs in the vicini ty make operations
quite difficult in even very light winds. The photograph,
taken at a considerable height above the s trip, may no t
have give n the readers a true idea of how steeply the
ridges to the right of and behind t he strip do rise. The
power line is effectively camoufl aged amongst dead trees.
I found during operations from this strip that even in
ligh t to mod er ate winds of normally worka ble strengths,
a nd especially N E-E-SE winds from behind the s trip,
turbulence low d own around the s trip was quite severe.
It sounds a little ha rd to believe, b u t som etimes cross
winds from op posite sides of the s trip could be
experienced in a single take-off or landing. It was always
necessary to 'give up' long before one normally would
in operations from a strip in more open coun try.
I think pro bably the most impo rtant o u tcome of such
an accident and the point I would like to make is
r einfo rced by your commen t at the start of the sixth
paragraph , where you s ta te 'd espite t he pilo t's earlier
impressions'. I have fo und, as probably every 'ag' pilot
has, that it is difficult to convince owners/m anagers of
properties tha t their strips have any shortcomings, and
I believe that through their lack of d etailed knowled ge
of aircraft operations, most would have no hesi tation, if
asked, in confirming th at a light aircraft could la nd at
t heir strip. Perhaps it is the fact tha t they watch 'ag'
pilo ts operate off the strips with seemingly little effort;
pilots though, with man y thousands of hou rs experience.
They of course may not appreciate the fact that an 'ag'
aircraft, la nding, is us ually emp ty of payload and in this
condition is both a good perfo rmer and highly
manoeuvra ble in the event of a go-around. The pilot is
also trained to pick out a go/no-go position fo r operations
on one way s trips; a position he does not comp romise.
It is better to 'get it on the ground' a nd use the super
heap or a gro und loop to stop rather than stall into trees
or a hill w hile trying to go-around.
I think it is very im porta nt tha t pilots, d uring their
training, be made aware of t he dangers of opera tions on
agricultu ral strips. They should be very cautious of any
suggestions that they make use of a strip established for
agricultural fl ying •
Aviation Safety Digest 104119
�Non-recovery from a spin
While on a test flight from East Midlands Airport, Glouceste~shire~ U.K. for the ren~wal of its <?ertificate
of Airworthiness a Beech Travel Air entered a spin from an intentional stall. The aircraft continued
to spin and struck the ground without recovering. The two occupants were killed and the aircraft was
destroyed.
The a ircraft, with a pilot and observer on board, was
und ergoing a series of routine tests in accordance wi th
a standard flight test schedule. These involved, in part,
a check of the single-engine climb performance, the
power-off stalling speeds and the handling characteristics
at the stall. The stalling tests were to be carried out in
both the 'clean' configuration and with the
undercar riage down a nd the flaps full y extended.
The pilot booked-out by telephone with Air Traffic
Control at East Midlands Airport for a one and a halfhour
flight. Taking offabou t mid-afternoon, the aircraft flew to
the test area a nd the pilot arranged by radio for the
provision of radar coverage while carrying out the tests.
The aircraft was identified on radar and was cleared
to climb to flight level 50 on a heading of 270 degrees.
Subsequent radio transmissions by the pilot indicated
that, four minutes later, he began the tests with a
single-engine clim b and then carried out stalls during
which the aircraft lost heig ht. At this stage, the pilo t
reques ted clearance from the radar controller to turn on
to 090 degrees and to climb back to flight level 50, _'to
carry on with these tests'. H e was cleared to make a nght
turn and to climb to the requested flight level. About a
minute later, the pilot reported climbing through flight
level 55 for flight level 60. No further transmissions were
received from the aircraft.
According to the radar controller, returns from the
aircraft indicated it turned right on to 090 degrees and
continued in this direction for about five nautical miles.
The controller then lost radar contact with the aircraft. H e
had not noticed any abnormality or fading of the radar
returns from the aircraft before losing contact, but when
he called the pilot to advise him he had lost radar contact,
he received no reply to this or subsequent calls.
Meanwhile, witnesses on the ground saw the aircraft
in t he vicini ty of a golf course, apparently in level Right,
heading in a south-easterly direction. The engine noise
was heard to cease, increase momentarily, then cease
again and the aircraft appeared to lose speed. Almost
immediately, the right wing dropped and the aircraft
entered a steep nose-down spin or spiral dive. Witness
accounts of the subsequent behaviour of the aircraft
varied, but the aircraft appeared to have entered a spin
to the rig h t which, after several turns, changed into a
spin to the left.
.
The aircraft did not recover and crashed on a fa1rway
of the golf course. Subsequent examination of the
wreckage and impact marks at the accident site showed
the aircraft had struck the ground at a high rate of
descent with no forward speed while spinning to the left.
The la nding gear was down and the fl aps were
full y extended.
20/Aviation Safety Digest 104
The pilot held a p r ivate licence and was managing
director of an aviation maintenance organisation which
undertook the inspection and flig ht testing of light
a ircraft for r enewal of Certificates of A irworthiness.
In the U.K., a pilot is not entitled to exercise the
privileges of his licence u nless it includc.s a va lid me~ical
certificate. Entries on the med ical certificate contamed
in the pilot's licence appeared to indicate he had
successfully undergone a routine examina tiqn a little over
a year before the accident and that he had been asse~sed
as fit to exercise the p rivileges of the licence for a penod
of 12 months from the d ate of renewal. The signature
on the medical certificate however, was that of an
authorised medical examiner who had died before the
date on which the examination had supposed ly
been conducted.
The records of the medical branch of the Civil
Aviation Authority (CAA) showed that this examiner
h.ad, in fact, cond ucted a medical examination on the
pilot some fi ve years before the accident and, ~n the bas.is
of this examination, had i~sued a medical cert1fi.cale vahd
for two years. T his was the las t recorded medical
examination for licence renewal purposes the pilot had
undergone. The d ates on the med ical certificate had been
altered and forensic examination revealed that the
original date of issue coincided with the pilot's last
medical examination. According lo the pilot's flying log
book, since the date of expiry of t he certificate, he had
flown close to 200 hours as pilot-in-command.
Some 20 months before the accident, the pilo t had
been admitted to hospi tal with symptoms subsequently
di agnosed as myocardial infarc tion (heart attack) . In the
U.K., it is the practice, as recommended by the
In ternational C ivil Aviation Organisation (ICAO), to
withhold a medical certificate, for a period of two years,
from any pilot who suffers from hea rt d isease. This
precautionary action is based on statistical evidence
indicating that a second heart attack, should it occur, is
most likely to happen within th is period, after which the
chances of a recurrence of an attack begin to diminish.
The pilot remained in hospital for 15 days. H e did no t
report his illness to the CAA and, according to his flying
log book, he resumed flying some th ree months after
t he attack.
There is little doubt that the pilot had not fulfilled the
medical requirements of his licence in th at he had not
submitted himself either to t he standard medical renewal
examination or to the particula r procedure th at would
have been necessary following his heart a ttack. H ad he
done so, it is improbable his licence would have been
renewed. I t is considered tha t the alteration of the dates
on the medical certificate were most probably made by
the pilot as the only person to benefit from so doing.
Post mortem histological examination of the pilot's
heart revealed a severe degree oflongstanding, active and
progressive coronary artery disease with evidence of
previous coronary thrombosis and myocardial infarction.
The severity of his cardiac condition was such that it
could have led to incapacitation or death at any time.
While there was no pathological evidence to indicate he
suffered a sudden incapacitation in flight, he could well
have experienced an incapacitation within the last few
m inu tes of fligh t without this being evident in an y
su bseq uen t examination.
The other occupant of the aircraft was employed by
the compa ny as a trainee aircraft ground engineer. H is
du ties on the fligh t were to record the test results. Before
j oin ing the company, he had flovm as observer on flight
tests of light single-engine and twin-engine aircraft and
on completion of the tests, had been given handling
instruction o n a casual basis. Examination of the flight
test schedule recovered from the aircraft indicated he was
record ing da ta until shortly before the accident.
The aircraft was undergoing inspection for the renewal
of its Certificate of A irworthiness. At the time of the flight
test however, the inspection had not been completed.
Checks of the range of movement of the control surfaces,
and fuel flow checks on a replacement foe! cell remained
to be done and the compass had not been swung. The
pilot was ad vised by licensed aircraft engineers that the
inspection was incompl ete but despite their objections
and refusal to issue a Certificate of Fitness for Flight, he
insisted on carr ying out the flight test.
The flight test schedule called for the aircraft to be
loaded as near the maximum authorised take-off weight
as p racticable. So far as could be ascertained, ballast was
loaded on board by the pilot and the observer. The
ballast consisted of a canvas bag of gravel and stones
contained in a cardboard box, 68 li tres of water in three
25 Iitre drums and two 25 lib·e sealed drums ofiso-propyl
alcohol (de-icing fluid). T he pilot insisted on using the
drums ofiso-propyl alcohol to make up a shortfall in the
total weight of ballas t required and over-ruled protests
by licensed engineers that it was an unsuitable ballast
material.
At the acciden t site, all five drums which had contained
liquid ballast were found to have ruptured on impact and
were outside the aircraft. Although the seals on the two
dru ms which had contained iso-propyl alcohol were still
intact, the body tissues of both occupants had been
contaminated with this liquid when the drums ruptured.
T he CAA flight test schedule for light twin-engine
unpressurised aircraft r equires, in part, a check to be
made of the aircraft's stalling speed and handling
characteristics at the s tall, both in the clean configuration
and with the landing gear down, and with the flaps fully
extended. Ii calls for the stalls to be carried out clear of
cloud, with the throttles closed and the propeller pitches
fully fine, and recommends that each stalling procedure
be commenced at an altitude not below 5000 feet above
te rrain. T he flight test schedule recovered from the
wreckage contained wri t ten entries indicating the aircraft
had been stalled in the clean configuration, ~hat the
speed and handling characteristics al the stall were
satisfactory, and that a further stall was being carried out
with the landing gear down and the flaps fully extended.
T he investigation .determined there was no doubt that
the accid ent was the result of a failure to recover from
a spin. The only pre-crash defects found in the aircraft
and its systems were excessive 'up' elevator and excessive
right rudder travel. Neither of these were considered to
be causal factors for the entry into the spin or the failure
to recover from it, as the evidence indicated that a test
stall and recovery had been carried out satisfactorily on
the aircraft in the clean configuration.
'
There was ample evidence to indicate that when the
accident sequence started, the aircraft was being
deliberately stalled with the landing gear down and the
flaps fully extended. In this configuration, a degree of
m ishandling by the pilot or his incapacitation could have
generated sufficient sidcslip to have produced conditions
favourable for the development of an inadvertent spin.
If a spin had ensued however, a competent and fit pilot
should have experienced no difficulty in recovering,
provided sufficient a ltitude was available.
The pathological evidence showed that, though the
pilot's death was caused by multiple injuries, his cardiac
condition was such that death or incapacitation could
have occurred at any time. For stalling tests to be carried
out safely, a reasonable degree of pilot competence, as
well as prompt and precise control inputs, are required
to effect a recovery. H ad the pilot suffered a heart attack
and become incapacitated during a stall manoeuvre, it
is entirely possible that the aircraft could have entered
an inadvertent spin. Any incapacitation might have been
either subtle or severe; a subtle incapacitation might not
have been apparent to the Right test observer though it
might have resulted in the pilot being unable to m aintain
control, whereas a severe incapacitation might have
resulted in an application of pro-spin control inputs.
It is apparent that some attempt was made to recover
from the spin because a change in the direction of the spin
rotation was observed. Although it was not possible to
determine whether this action was taken by the pilot or the
observer, it was considered unlikely that the flight test
observer, with his extremely limited flying experience,
would have been able to effect spin recovery.
The in vestigation determined that the action of the
pilot in fl ying the aircraft before all the mandatory
inspections had been completed was high-handed,
irresponsible and potentially dangerous. Although the
absence of a Certificate of Fitness for Flight was not
considered to have been a causal factor in the accident,
it was disturbing that such a state of affairs could exist
within a professional organisation serving the public. T he
pilot's selection of iso-propyl alcohol, a material totally
unsuitable for use as ballast, was apparently symptomatic
of a state of mind in which a determination to complete
the test flight, whatever the obstacles, transcended
all reason.
The investigation concluded that the accident resulted
from the failure to recover from a spin which occurred
during a stall. T he reason for the spin entry could not
be determined but the possibility that the pilot became
incapacitated cannot be dismissed•
(Condensedfi"om a report published by the Accidents Investigation
Branch, United Kingdom.)
Aviation Safety Digest 104/ 21
�In brief
...- _
___, _
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_....,....
.....
:..,1•·
-'
-~~
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.... •
...,....
The pilot of a Cessna l 85A tug was glider towing from
the grassed flight strip on the left-hand side of a runway
aligned 01. The weather was fine a nd the surface wind
was about030degrees, 10-15 knots.
After completing an aero tow, the pilot of the tug
aircraft approached for a wheeler la nding on the flight
strip. When conducting wheeler landings in cross wind
conditions he h ad developed the technique of holding the
tail up with elevator in order to provide directional
control with rudder for as long as p ossible. He states that,
normally, he would not apply brakes until the tail wheel
was on the ground but other information sugges ts that
he may have developed a habit of applying some bra king
at about the time the tail was lowering.
On the first landing at te mpt from this approach, the
aircraft bounced a nd the pilot conducted a go-around.
On the second landing the aircraft touched down
smoothly. The p ilot applied more than th e usual forward
pressure to the control wheel in ord er to keep the main
yvheels firml y on the ground but, a t the stage where the
22/Aviation Safety Digest 104
tail usually started to lower with reducing speed, the
aircraft started to nose over. The pilot pulled th e co ntrol
column fully back but to no avail. The aircraft tipped
on its nose and continued over on to its back, coming
to rest 15 m etr es beyond the firs t propel !er slashmark.
Investigation established tha t the aircraft's centre of
gravity was close to the forward limit.
It would have been be tter to have placed the tail wheel
on the ground while elevator and rudder control
remained effective, utilising tail-wheel stee ring and
judicious bra king to ma in tain d irectional control, a nd
holding the stick hard back so as to prevent a ny
possibility of nosi ng over.
In discussion following t he occurrence ~he p ilot said
that prior to the accident he had believed it would not
be possible to tip a Cessna 185 over on to its back d uring
la nding but was no t specific regarding the basis for his
belief. This acciden t, and others, clearly indicate that it
can be done •
The pilot ofa Bell 47G-5A helicop ter was assisting in
cattle mustering on a property in Queensland. H is
specific role was to ferry men a nd eq uipment, report on
the position a nd movement of cattle and relay messages
under th e direction of the head stockman.
D uring a fligh t late in the afternoon the pilot noticed
a small mob of cattle heading along a fence about 12
kilometres southwest of the homestead. H e returned to
base where he refuelled the aircraft, topped up the engine
oil a nd took on a p assenger to act as observer. T he
helicopter departed at 1630 hours and , after turning
some stray cattle towards the musterers, the pilot
contin ued to check o n the movement of the small mob
he h ad seen earlier. The mob was still t ravelling along
the fence but hesitated a t the edge of a small swamp.
T here was a clear a rea some 180 metres behind the cattle
where the pilot decided to land and wait to see whether
they could cross the swamp.
T he p ilot brought the helicopter in to a hover but the n
thought that before landing he should r eport to the head
stockman in case the latter wan ted to send men to muster
the small mob. A normal take-off from the hover was
made into the five to ten knot easterly wind a nd at a
height of 50 feet a t abou t 50 knots the helicopter
commenced a gently climbing turn to the left on to a
northerly heading.
At a h eight of about 70 feet the p ilot and passenger
heard unusual noises emanating from t he vicinity of the
engine and transmission. The pilot's initial reaction was
to slightly reduce the throttle and collective pitch
settings, but as he did so he felt a fu r ther loss of power
and the helicopter began to settle. H e p repared for an
im mediate forced landing, in tending to turn 45 degrees
to the right to bring the helicopter into wind a nd clear
of some trees. H owever, at this point the h elicopter began
to shake violen tly and the pilot elected to la nd straight
a head.
A t or just before touchdown, at a low forward speed,
the main rotor blades struck the branches of one of the
trees. The helicopter pitched forward a nd the blades
struck and severed the tail boom, ruptured a fuel tank
and struck the grou nd several times before the helicopter
rocked back and came to rest on its skids.
D uring the in vestigation it was noted that the oil filler
cap/dipstick was missing and the engine oil level ba rely
regis tered when dipped with a replacement d ipstick.
T here was evidence that oil had been escaping from the
filler hole during flight and the damage to the engine was
consistent with inadequate lu brication.
The pilot could not specifically remember replacing
the oil filler cap/ dipstick after topping up the oil at the
homestead•
Aviation Safety Digest 104123
�)
Fresh air vent or fuel shut-off
control?
The following accident occurred in New Zealand and was investigated by the appropriate authorities.
The lessons to be learned are applicable anywhere in the aviation world and do not just apply to the
type of aircraft involved on this occasion.
(From an article in the N.Z. Flight Safety magadne.)
The pilot, who was the holder of a valid private pilot
licence, had a total flight time of 141 hours but during
the three months preceding the accident had flown only
35 minutes. This was in a Cessna l 77B, the type he had
hired on this particular day to take a woman a nd her
two children on a local sightseeing flight. Prior to the
aircraft's departure for a nearby airstrip where the pilot
had arranged to pick up his passengers, the chief flying
instructor of the aero club briefed him on the differences
between the l 77B and other Cessna types which he
usually flew, and also assisted him with the pre-flight
inspection.
The short solo flight to the airstrip was uneventful and
after the aircraft had been brought to a stop, the
passengers climbed aboard. The two children were
placed in the rear seat and their mother in the front seat.
The aircraft subsequently took-off and proceeded on the
local pleasure flight.
This was the first time the passengers had flown in a
light aircraft and apart from some discomfort as a result
of the warm temperature, they were enj oying the flight
immensely. I t was shortly after the pilot had pulled a
black knob to open the cabin fresh air vent that the
engine stopped without warning. H e immediately carried
out what he considered to be a comprehensive check for
the cause of the stoppage but was unable to regain use
of the engine.
The pilot elected to attempt a forced landing on a
nearby beach but it soon became apparent that it was
beyond gliding range of the aircraft. H e therefore
selected an alternative landing site in a paddock which
was sometimes used as an agricultural strip.
After touch down, the aircraft over-ran the paddock
and tore through a light fence. This r esulted in fail ure
of the nosewheel attachment causing the aircraft to tip
forward and come to rest inverted. Although the pilot
and the two children were uninjured, the woman
received minor frac tu res and severe bruising. She was not
restrained by the full safety harness provided in the
aircraft.
Shortly after the accident the pilot re-entered the
aircr aft to render it safe by switching off the electrical
supply. Pondering why there h ad been no fresh air after
he had operated the black knob, he again moved the
control to and fro a number of times to check its action,
then left it pushed forward in its original position.
Investigation
Subsequent examina tion of the engine and components,
which included a grou nd test run, failed to reveal
an ything wrong with the power plant or any of the
aircraft's systems. Wh y, then, did the engine stop in
24/Aviation Safety Digest 104
flight, and why did the pilot's checks fa il to establish the
cause of the stoppage?
The answer to the firs t part of the question finall y
became clear on the day after the engine grou nd test had
been perfo rmed. While giving an account of his actions
in the air, the pilot men tioned that it had been a warm
day and the cockpit conditions soon became ra ther stuffy
for his inexperienced passengers. To make them more
comfortable, he looked about for an additional source of
fresh air. Sighting a black knob below the instrument
panel, he pulled it out, assuming it to be the control for
an a ir vent. He was feeling for the inflow of air w hen
the engine stopped. Little wonder, for unbeknown to the
pilot, he had operated the fuel shut-off control.
The answer to the second, and equally important part
of the question, is not quite so clear cut and one that
is often described indifferen tly as 'an unfortunate
combination of circumstances'. But this is precisely how
a great number of a ircraft accidents occur, therefore the
'circumstances' of this pa rticular mishap bear revealing.
T he investigation into the cause of this accident was
made difficult as a result of the aircraft being tampered
with prior to the arrival of an investigator. In accordance
with the New Zealand Regulations no person is
authorised to alter any control or remove any item from
an a ircraft following an accident - other than to
facilitate the removal of the occupants and to ensure the
aircraft is rendered safe.
On this occasion, t he a ircraft's life jackets, fuel dip
stick, approved fligh t manual, compass, fire extinguisher,
medical kit, radios, and the nose wheel, had all been
removed without authority. Although the pilot had acted
promptly and correctly in releasing his passengers and
disconnecting the power supply, his tampering with the
fuel shut-off control resulted in a considerable waste of
time and expense in the su bsequent investigation of the
engine failure. Ironicall y, it was only through his
disclosure of operating the fuel shut-off control for
another purpose, both in the air and after the acciden t,
that the investigation was fore-s hor tened.
Contributing factors
The chief flying instructor of the aero club did not str ess
the location of the fuel sh ut-off control in th e l 77B when
briefing the pilot prior to initial take-off. Apparently it
was club practice not to draw the attention of pilots to
the existence of the knob s ince experience had shown tha t
many used it as par t of the normal engine shut down
procedure. As a result, other pilots who subsequently
attempted to start the engine were unsuccessful until it
became apparent that the control had been left in the
OFF position.
The control itself in that particular aircraft bore no
identifying marks or signs and the placarding 'FUEL
SH U T OFF-PULL OFF' could be misleading, being
printed on the face of the main centre panel 'around the
corner' from the control knob. F urthermore, the control
was not safctied in the O N position with lock wire to
prevent inad vertent operation, as specified in the
manufacturer's ser vice manual.
The Pilot's Operating H andbook, produced by the
aircraft manufacturer, advises in the Emergency
Procedures Section under engine failure during flight,
'fuel sh ut-off valve - ON'. In the procedures for engine
fires, it s tates, 'fuel sh ut-off valve - OFF (pull sharply
to break safety wire)'. However, while the emergency
drills involving use of the fuel sh ut-off are quite clear,
the pilot could be exc used to some extent for not applying
them correctly since there was no handbook for that
particular aircraft, despite the fact that the operator had
received an official warning of its absence some time prior
to the accident. Although the pilot's immediate actions
following the engine failure included selection ofleft and
right tanks, returning the selector to both tanks, then
switching O N the electric fuel pump, he did not check
fuel pressu re. H ad he done so, it might have alerted him
to the fact that he had cut off the fuel supply to the
engine. This omission could also be excusable since that
particular check is not called up in the handbook. Finally
- and most importantly- the pilot should not have
been experimenting with a control in the air without
being fully aware of its purpose. A longer time spent on
the gro und getting to know each and every knob, switch,
ha nd le, control, etc., particularly their application
during emergency drills, could have prevented the
accident.
Conclusions
This was an avoidable accident caused by a misjudged
forced landing approach after the pilot had unkpowingly
closed the fuel shut-off control in flight. Lessons to be
learned from the factors which contributed to the
acciden t can be summarised as follows:
• M ake sure you know your aircraft before you fly. If
you are at all uncertain about any control knob, lever,
or any switch or instrument, find out while you are still
on the ground.
•Make sure you know the emergency procedures in
detail for each aircraft you fly. I nsist that a copy of
the Pilot's Operating H and book or Owner's M anual
be made available for study.
•Vital controls in the cockpit, particularly those which
may be operated inadvertently, must not only be
safetied if required by the servicing manual, but should
also be clearly marked as an added safeguard.
• Ensure that all passengers are properly briefed on
safety procedures, and insist on the use of upper- torso
restraint equipment when fitted in the aircraft. Set an
example by always using it yoursel(
• Finally, if you are fortunate enough to survive an
aircraft accident, give the investigators the best chance
of establishing the cause by leaving everything alone.
Only move those items essential to the evacuation of
persons from the aircraft, or when taking precautions
to ens ure the aircraft is safe from further damage •
From the incident files
The pilot of an Australian-registered Piper PA32/ 300
aircraft recently reported that during his pre-take-off
control checks only about ha lf the normal control column
travel could be obtained. Investigation by the pilot
revealed that an eight centimetre long screw had
dropped through a hole in the lower rear corner of the
glove compartment and was restricting the travel of the
aileron/ elevator 'T' bar, located below the glove
compartment area.
On receipt of the pilot's incident report, a check with
the local Piper agent established that the problem was
common to several models of this range of aircraft.
The holes had been made in the lower corners of the
glove compartment during man ufacture to allow
bending of the sheet metal without cr acking the material.
A subsequent check of the Piper Service Bulletins
revealed that the problem had been recognised by Piper
and affected PA32/260, PA32/ 300 and PA34/ 200 aircraft
in a range of serial numbers. The corrective action
required was to insert restrictor plugs in the holes.
Many service bulletins issued by manufacturers are
not made manda tory by air worthiness autho rities.
H owever on this occasion experience has shown the
above problem to be of such a serious nature that
Australian Airworthiness Directives DCA/ PA32-58 and
DCA/ PA34-28 have been issued with effect from
31 October, 1978.
Until all affected aircraft have been modified it would
be advisable for pilots to ensure that the glove
compartment of the types mentioned contains no items
which could fall through the holes. If inspection of the
glove compartment reveals that the aircraft has not been
modified, you should refer the aircraft owner, hiring
agency or your servicing organisation to Piper Service
BulletinNo412 •
Aviation Safety Digest 104/ 25
�Double harnesses for aerobatic
aircraft
It is only comparatively recently that we have seen the introduction into this country of aircraft such
as the Pitts Special which are capable of performing advanced aerobatic manoeuvres of the type flown
in international competition.
·
Search and rescue, part 4
Procedures used to determine the search area were covered in a previous article in this series on the
Search and Rescue organisation. Having decided upon the precise area to be searched, the next step
to be taken by a SAR Mission Co-ordinator (SMC) is to form a plan which will ensure adequate coverage
of this area.
(Photograph courte~ ofAircraft.)
In their standard configuration, these aircraft usually
have provision for the installa tion of an extra lap-type
seat belt in addition to the normal fo ur or five point
symme tric safety harness. When the aircraft were first
registered in Australia h owever, these extra belts were
not fitted, as the D epartment did not permit the use of
restraint systems in aircraft which r equired the operation
of two release d evices to free an occupa nt. The
philosophy in not permitting two restraints to be installed
was tha t the need to oper ate two separate releases may
cause a d elay in the evacuatio n of a n aircraft after a n
acciden t and th a t a second restraint, if left unfas tened,
introduces the very real hazard of possible interference
with controls.
On the other h and, aerobatic pilots claim tha t a
normal harness, on its own, ca n allow the inverted
occu pant to pa rtially sag from his seat, with the result
t hat the main restraining force is taken on the shoulders.
An additional la p belt helps maintain the thighs firml y
in place. Furthermore, and this p oint is made very
strongly by the p ilo ts concerned, the re is additional
' peace of mind' to be d erived from the use of a n extra
lap belt, thus allowing better concentration fo r the
perform a nce of th e pilo ting task itself during competition
fl ying a nd training.
The p oints.made by the p ilots a re valid, especially
when consideration is given to the type of aerobatic fl ying
26/Aviation Safety Digest 104
carried out by aircraft such as the Pitts, a nd to the
frequency and duration of the sustained n egativeg
manoeuvres involved. As a consequence, the Department
has reviewed its policy and will n ow, in certain cases,
permit the installa tion of a n additio nal restraint under
a n Air N avigation Order concession p rocess. Any su ch
concession is confined to a .lap belt only, and its
installa tion is subject to th e follo wing conditions• The aircr aft m ust be in the acro batic category and of
a type used in ad vanced aerobatic competition or in
training for this type of competition - th at is, fl ying
involv ing sustained high negativeg manoeuvres. At the
present time, those aircraft on the Australia n register
w hich would be eligible are all models of the P itts, the
Bellanca D ecathlon and the Stam pe SV4.
• The aircr aft must already be fitted with a symmetric ·
four or five point safety harness. The additional lap bel t
will not be considered for approval in association with
a harness which is only of the three point variety.
W ith this change in policy, it is essential that pilots
bear in mind th e requirement that h a rnesses and belts,
w hether in occupied or unoccupied seats, must always
be secured before flight to preven t interference with the
controls. The possible consequences of such interference,
especiall y if aeroba tics ar e being perfo rmed at low level
such as during displays or competitions, need no
ela boration •
Suitability of aircraft
The pla n is d irectly rela ted to the suitability and number
of search aircraft available and the area each individual
aircr aft can adequately cover. Factors such as endurance,
d ista nce from base to the search area, alternate
require ments for the recovery aerod rome, flight time
li mita tions a nd hours of daylight available for visual
search ing m ust be ta ken into account.
Selection of aircraft type is based on suitability for the
particular task. H igh speed, long endurance aircraft with
good n avigational capability are better used in large
a reas far removed from bases, while for contour searches
aircraft m ust be manoeuvrable at relatively slow speeds,
capable of small turning circles and adequately powered
to provid e a relatively h igh rate of climb. I n general
terms, the high wing light aircraft is best suited for this
p urpose. T he special fligh t characteristics of helicopters
make them extremely useful for SAR purposes since their
slow flight an d hover cap abilities permit close scanning
of forest a reas . Helicopter pilots can effect rescues in
diffic ult terrain or from the sea, whereas pilots of
conven tional aircraft are usually restricted to directing
surface rescue units a nd supply dropping.
L ight twin-engine general aviation aircraft arc
available along almost the entire Aus tralian coastline and
because th ey are often closer to the search scene than
more sophisticated a ircraft they are freque n tly utilised in
the early stages of a search. General aviation aircraft are
reason ably effec tive up to approximately 80 kilometres
from the shore. They m ay prove useful at greater
distances bu t the required navigational accuracy as well
as search integrity degenerates rapidly beyond
80 kilometres.
The role of the general aviation pilot
The general aviation pilot can play an important role
as he is usu ally familia r with his normal area of
operations and can provide a valuable serviced uring a
search. In par tic ul ar the light aircraft operator in
outback ar eas may be so well acquainted with the area
that he can recognise something unusual at far greater
distances than a casual observer. H e is usually aware of
possible land ing areas within the region and on several
occasions in the past has been able to locate a downed
aircr aft far quicke r th an a normal systematic search.
This u northodox proced ure is often used when looking
for persons lost in th e bush.
Calculating the search effort
H aving ascertained the number of suita ble aircraft which
are available, the SM C m ust decide the most effective
track sp acing to be used. This is the distance between
adjacent search tracks and varies in relation to the size
of the search target. If a wide track spacing is selected
a large area will be covered in a set time; conversely, a
narrow track spacing will reduce the area searched for
the same period of time. As a result, the coverage of the
area or quality of the search will differ. In broad terms,
the selected track spacing is considered as a measure of
.search effort.
Obviously a major limiting factor in planning a search
is the time which an aircraft can remain in an area. This
is calculated by deducting from the known endurance the
time interval to and from a search area. F rom this figure
15 per cent is deducted for IFR category aircraft as well
as a standard 45 minute fixed reserve. Alternate
aerodrome requirements, if applicable, further reduce
available search time. Flight crews will sight many
objects that require investigation and five minutes per
search hour is deducted for this purpose. The result is
that an a ircraft which is available in a search area for
six hours can be planned to search for only 5.5 hours and
the size of the area allocated to it is reduced accordingly.
Time for searching
When the sun is not far above the horizon in the early
morning and late afternoon, long shadows and poor ligh t
reduce the period available for effective daylight visual
searching. This time reduction must also be considered.
Periods of 45 minutes after sunrise and before sunset are
unsuitable but unfortunately it is sometimes necessary to
utilize this time because of local conditions. This is
particularly relevant when searching over tropical r ain
forest or in mountainous country where downpours and
cloud build-ups prevent searching at more suitable times.
Track spacing
D uring a search it is usually necessary to use a wide
variety of aircraft types often having different search
speeds. In consideration of this factor, a technique has
been developed which makes it possible to quickly a nd
accurately ascertain the number of aircraft required to
cover a total area, as well as determining individual areas
for each specific aircraft.
A mid-range speed of 150 knots is used for comparison
purposes and the speeds of all air~raft in volved are
converted per medium ofa formula to this standard
speed. A graph known as the D ecision Aid Graph (DAG)
is constructed on this basis. T he DAG is a useful and
highl y versatile reference guide which compares size of
area with track .1pacing and search time to the base speed
of 150 knots. Thus, commencing with any two known
factors the other information required is easily
de termined.
Aviation Safety Digest 104/ 27
�Based on past experiments, a ta ble of fig ures for both
la nd a nd sea searches is used to calculate track spacing.
The 'search visibility' in this table is related to the size
and type of target, meteorological visibility and search
altitude. Corrections are also made for effects of cloud
coverage, state of the sea (presence of white caps) or type
of terrain (vegetation) .
of the search object, state of sea or topography to be flown
over, weather en-route and in the search area, track
spacing, search pa tterns, signalli ng and survival
equipment carried by survivors, communications to be
used and supply dropping tech niques, if a pplicable.
Separation of aircraft
Although the pilot will be made aware of activity in
adj acent areas at the planning stage, separation between
aircraft is provided. This is achieved by assigning altitude
o r lateral separation. I n the latter case when vertical
separation is no t possible, points ofentry into search areas
are selected so that as aircraft move across their
designated areas, lateral separation is maintained. In
some cases, separation will be achieved by varying the
commencement time in adjacen t areas.
Assignment to the search area
H aving determined the area an individual aircraft can
cover , how is it assig ned to that area? Before this can be
done, consideration is given to a nµmb er of factors
concerning the alignment of areas and the track direction
in those ar eas. These factors are vital to the integrity of
the search and include:
- navigational capability of the aircraft
- wind directio n and speed
- sunglare
- drift direction (marine area)
- topography
- search pa tterns to be used
- local knowledge of search crews and
- position of d eparture and recovery bases rela tive to
the search area.
The allocation is completed by giving a thorough and
comprehensive briefing to the pilot in command. H e is
provided with an appropriate map depicting the search
area and specifically highlighting the area allocated to
his aircraft. The pilot will be informed on all aspects of
the operation including the current situation, description
Use of observers
If the aircraft is large enough, a n umber of observers are
made available. For aircraft such as Fokker Friends hips,
a trained observer leader will be provided and he will
a ttend the briefing with the pilot. H e is then responsible
for briefing all observers on board including a review of
scanning techniques a nd methods of reporting sightings.
The method used to sight the target is'not unlike that
used by aboriginal tracker s. Basically this consists of
looking for the 'unusual' or foreig n signs or obj ects in the
immediate environment. Such things as colour contrast
from a yellow life raft against the ocean background,
brown foliage in tropical rain forests, glints of silver in
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arid country, and smoke, often indicate the location of
the target.
I rrespective of how well a search is planned, the success
of that search is dependent upon the efficiency of the
observers. A search can only be regarded as satisfactory
if the persons engaged on the actual scanning know what
they are doing and how to achieve the best results.
It is important that observers are high ly motivated to
the task so that their one aim and purpose is to locate
the search obj ect as soon as possible. This, of course,
could mean the saving of lives and the prevention of a
large, prolonged and costly search. T he effectiveness of
observers depends on the following factors
- n um ber available
- previous experience
- physical condition (alertness)
- suitability of observing positions
- time on task (efficiency is known to deteriorate
rapidly after two hours)
When the pilot returns from his sortie a debriefing
session is held to determine whether all of the assigned
area was searched and how accurately the assigned track
spacing was maintained. This information is important
to the SAR mission co-ordinator so that he can assess the
effectiveness of the search, which in turn influences his
fu ture planning decisions.
Probability of detection
As has already been s tated, track spacing is directly
rela ted to the search effort or, in other words, coverage
of the area. T he objective of any SAR mission is a
systematic search of selected areas, in order to obtain the
maximum probability of detecting survivors. Using a
mathematical formula, a 'coverage factor' can be
calculated which is a measure of the search results. T his
is known as the Probability of Detection (PODYand is
expr.essed as a percentage.
For reasons such as shortage of suitable aircraft, or
because areas remain unsearched because of aircraft
unserviceability or adverse weather, the first search may
produce a POD of only 47 per cent. H owever, if the area
is covered five times in suitable conditions the POD can
be increased to 96 per cent.
This procedure includes a progressive and systematic
enlargement of the area. Based on the datum point, each
search will cover a larger area than before. At the end
of the fifth search an area equal in size to the original
area has been searched five times while the outer edge
of the enlarged areas has only been covered once. As the
target is more likely to be near the datum rather than
at the outer edges, this ' repeated expansion concept'
concentrates the greatest POD over the most likely
position.
I n some SAR actions where the first two or three
searches have not produced results, search tracks are
often realigned 90 degrees to the original d irection
allowing scan9ers to see the area from a different angle.
The final article in this series will deal with supply
dropping and the rescue phase ofa SAR mission•
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Aviation Safety Digest 104/ 29
�Refuelling from drums
Our Man in the Dustcoat is at it again (did you see him last issue hand-swinging the Aero C~m!11ander
propeller?). Readers will be interested to know that he is an employee of that well _known av1at1on
identity, Murphy. Apart from putting aeroplanes together the wrong way, Murphy 1s rather haphazard
in teaching his staff correct procedures - in this case, refuelling.
We all know wha t happens wh en a n aircraft engine fails
in flight - the aircraft often ge ts ben t and, if the failure
was caused by fuel starvation or contamination, the
pilot's ego is severely dented as well. Operators are awar e
that if there is insufficient fuel on board a n airc raft before
depa rture the aircr aft will not r each its d estination a nd,
therefore, they ta ke care to refuel the aircraft. T hose who
do n ot, usually b ecome s ta tistics. It is equally as
importa nt to put only the righ t fuel into the aircraft, so
quality control ch ecks a re vital.
But h ow much a ttention is our man p aying to correct
a nd safe procedures du ring refu elling, in this insta nce
from drums?
Air Na vigation Orders sp ecify the proced ures to be
used while refu elling to ensure safety at all times.
C ontra ry to t hese requirements the scen es o n page 19
show the following d eficiencies: (a) T h e aircr aft a nd th e fuelling equipment shou ld n ot
be dos.er tha n nine me tres to an unsealed building .
(b) Static leads should be connected to ensure bonding
between the drum, the pump a nd the id entified
ai rcraft earthing point. If th ere is a ground earthing
poin t availa ble, the refuelling equip ment a nd th e
aircr aft shou ld be earthed.
(c) The aircraft shou ld be positioned so th a t i t can be
quickly moved to safety in an emergency.
(d ) The area in which refuelling operations a r e being
conducted is a 'No Sm oking' area. Persons operating
fuelling eq uipmen t sh ould n ot carry m a tches,
cigare tte lig hters or objects which could constitute a n
ignition hazard and no person sh ould sm oke or use
naked fla me with in 15 metres of th e aircr aft a nd the
ground fuelling equipm en t.
( e) Fire extinguishers should be positioned in the vicinity
of the aircraft and th e fuellin g eq uip ment.
There a re oth er requirements a n d r eference to ANO
Section 20.9 will provide t hese. Additional to the above,
the fuel compa nies recommend proced u res designed to
ensure quali ty con trol of the fu el. Complia nce with these
recommenda tions will ensu re th at only fuel will be added
to the aircraft tanks. Our M an in the Dustcoat obviously
failed to com ply with an importa nt proced ureBefore p umping, the drum should be stood on end and
til ted by placing a piece of wood abo ut 50 mm thick
u nder on e side, so that th e la rge bu ng is on the lower
side. W i th the drum lying on its side as sh own, the su ction
stand pipe, designed so that fuel cannot be drawn from
within 80 m m of the drum bottom , ca nnot fu nction
properly. Water or other contaminan ts could be drawn
from the drum.
After tilting the drum it should be allowed to stand
30/ Aviation Safety Digest 104
as long as p ossi ble, preferably one hour, bu t no t less than
15 mi nu tcs to let water or other sediment settle to the
lowes t p oint.
As well as the above co nsidera tions, there are other,
equally important precautions which should be observed
in handling a nd storing drum fuelDru ms should be stored on their sides with t he two
bungs level horizontally. If the bungs te nd to weep
with a drum on its side (as may hap pen if the drum
has been opened previously), the drum may be stored
upright but tilted with the b ungs away fro m the low
side so moisture can not accumula te around th e
openmgs.
The drum to be used should b e checked before
comme ncing refuelling to ensure that( a) its markings a nd the contents are consistent ;
(b) it is not aged;
(c) there h as been n o obvious contam ination during
storage;
(d) it contains no free water. A positive method, such
as the use of water detecting paste or paper is a
necessity.
U refuelling from j er ry cans, etc., the fuel should be
filtered th rough a mesh strainer, avia tion type water
trap fun nel.
If refuelling with a pump fitted with a fil ter, check
the fil ter b efore and after refuelling for signs of water
and other contaminants.
If possi ble, drums should be taken to the aircraft on
the tray of a vehicle, not rolled along the ground. If
.it is n ecessary to roll the d rums, they m ust be given
the longes t settling period possible before
commencing to refuel.
Unlike the Man in the D ustcoat our readers know the
importa n ce of employing the correct refuelling
proced ures, witl1 regards to both safety d uring refuelling
a nd the quali ty control of the fuel added to the aircraft.
Con tinue to use the correct procedures and you will
avoid becoming another statistic! •
r
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'
In 1977
pilots on private and business flights flew
37% of all general aviation hours
and were involved in
64 % of all accidents
68% of the fatal accidents
74% of the fatalities.
WHY?
Aviation Safety Digest 104/ 31
�
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https://collections.heritageoftheair.org.au/files/original/15627a0553b12e942fd96517306c456b
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Department of Transport - Australia
103/1978
AVIATION
SAFETY DIGEST
No I
lncludtn& Summary of Accldenc.
and Incident Reporu
DIGEST -·- -
JULY, 19U
----·.....-..... -·,,..._....,._
Inside
Index for
Digests 1-100
AVIATIO ._N
s·A TE -r" { --
r•
+
'
.... AVIATION
SAFETY
+
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�103/1978
Contents
3
Beware the rock-filled cloud
The pilot of a Cessna 182, en route to a cattle sale,
encountered low cloud while cruising at 1500 feet Instead
of his flight planned altitude of 5000 feet. The wreckage
of the aircraft was subsequently located about 70 feet
below the summit of a mountain rising to 1671 feet.
4
Wear your seat belt the right way
6
Are you ready for take-off?
8 An accident report revised
As the result of a petition from the Airline Pilots' Association
and to take account of new knowledge gained from more
recent investigations, the National Transportation Safety
Board re-opened the Investigation into the crash of a Boeing
707 on final approach to Pago Pago International Airport.
12 Would you swing the propeller this way?
14 Good show all round
While taxi-ing out for take-off, the crew of an Electra
freighter checked the o n-board Welght/CG computer and
calculated t hat the aircraft was about 1600 kg above the
documented weight. At the same t ime the senior loading
clerk at the freight terminal realised that a discrepancy
existed and recalled the aircraft. A fault was subsequently
discovered in the automatic electronic scales used to
weigh the aircraft load.
15 Index
19 How to turn on the aerodrome lights
20
Take notice of empty fuel gauges
21
Thelastgasp!
A Cessna 182 ran out of fuel after landing at Mackay aerodrome and had to be refuelled on t he runway before it
could be taxied to the parking area.
22
Search and rescue, part 3
The search area
25 The human element
Three short articles reproduced from the Aviation Safety
Letter, Canada, illustrate various aspects of the human
element In aircraft accidents.
26
Pre-take-off 'lethal' actions
Aviation Safety Digest 1s prepared in the Air Safety Investigation
Branch and published for the Department of Transport through the
Australian Government Publishing Service, m pursuance of Regulation 283 of the Air Navigation Regulations. It is distributed by the
Department of Transport free of charge to Australian licence holders
(except student pilots), registered aircraft owners, and certain other
persons and organisations having a vested operational interest in
Australian civil aviation.
Aviation Safety Digest is also available on sµbscription from the
Australian Government Publishing Service Enquines should be
addressed to the Assistant Director (Sales and D1stribut1on), Australian Government Publishing Service, P.O. Box 84, Canberra ACT
2600. Subscriptions may also be lodged with AGPS Bookshops in
all capital cities.
Change of address:
Readers on the free distribution list should notify the Department
of Transport, P.O. Box 18390, Melbourne, Victoria 3001.
Subscribers should contact the Australian Government Publishing
Service.
© Commonwealth of Australia 1978. The contents of this publication
may not be reproduced in whole or in part, without the written auth·
ority of the Department of Transport. Where material is indicated to
be extracted from or based on another publication, the authority of
the originator should be sought. The views expressed by persons or
bodies in articles reproduced in the Aviation Safety Digest from other
sources are not necessarily those of the Department.
Pilot contributions and correspondence on articles should be
addressed to the Aviation Safety Digest, Department of Transport,
P.O. Box 18390, Melbourne, Victoria 3001.
RM76/30216(3) Cat. No. 78 9122 5
Printed by Ruskin Press, 39 Leveson Street, North Melbourne,
Victoria.
Note: Metric units are used except for airspeed and wind speed
which are given in knots; and for elevation, height and altitude
where measurements are given in feet.
A pilot contribution.
27 'I told Junior to make sure the field was clear'
28
In brief
30 Turbo-charger failure
30
Avoiding loss of communications
31
Be prepared for carburettor icing
Editor's note:
In response to many requests from readers an index has been
prepared for Digests 1·100 and is included in this issue. The list
provides reference to subject matter by articles but is not exhaustive.
Space has been provided for personal notes so that readers may
list particular points of interest.
The pilot and owner of a Cessna 182 resided on a grazing
property situated in flat, open country. The area
res triction on his private licence had been lifted for abou t
12 months and his total fl ying experience amounted to
some 140 hours. He held no instrument rating and mos t
of his private flyi ng h ad been carried out in the area in
which hi s property was located.
T he pilot had a rranged to fly to a town some 520
kilometres distant in order to attend a cattle sale and,
soon after daylight, telep honed the appropriate Briefing
O ffice a nd lodged a flight plan for both the outward and
return legs of the fl igh t, nominating a SARTI ME of 1800
hours. H e was briefed on the area meteorological
forecasts which predicted scattered stratus cloud with a
base of 2000 fee t, broken cumulus cloud with a base of
4000 fee t an d a visibili ty of 40 kilometres reducing to
5000 metres in rain showers.
Wi th two p assengers on board the pilot departed at
0720 hours and at a bout 0755, landed en route at another
property to pick up a third passenger. P rior to this
landing the pilot reported he had encountered light fog
in the circuit a rea. T he aircraft departed again at 0809
hours but though the flight plan indicated the pilot's
intention to cruise at 5000 feet on this leg, he reported
position on track at 0834 hours at an altitude of 1500
feet. No further comm u nications were received from the
aircraft. Some 50 kilo metres beyond the town over which
the pilot reported his p osition, the terrain rises into a
series of small ranges with isolated spot heights to an
elevation of 1800 feet.
At about 0840 hou rs an aircraft was seen and heard
fl ying in th is a rea at a very low height and heading
towards hilly terrain surrounding a mountain which rises
to 167 1 feet. There was extensive low cloud in the area
at the time a nd the tops of the n earby hills were obscured.
The aircraft subsequently disappeared from view into the
cloud.
When nothing was heard from the pilot by the
expiration of his SARTI ME, search and rescue action
was commenced and, at 1120 hours the following day,
the burn t-out wreckage of t he aircraft was located on a
slope of t he mountain about 70 feet below its top. All
four occupants had been killed.
Flying virtually right on track, the aircraft had initially
struck trees, then a rock shelf, on the steep mountain
slope while in a wings-level, climbing attitude, heading
in the direction of the planned destination. Detailed
examination of the wreckage did not reveal a nything to
suggest that the aircraft: was incapable of normal
operation prior to the acciden t.
T he question which this accident raises is why the pilot
fou nd himself in the situation in which he and his
passengers lost their Jives.
T he pilot's instructor told the investigators that, in his
view, the pilot was often pressed for time but that, though
he was a confident person, he would 'give a flight away'
if after departure he found the weather was unsuitable.
T he instructor could recall several instances where he
had received telephone calls from the pilot to advise that
a flight had been abandoned because bad weather was
encountered after departure.
On the other hand the holder of a private licence who
knew the pilot well told the investigator th at in his
opinion the pilot tended to be over-confident in his
approach to flying and took unnecessary risks. He
recalled several occasions when the pilot had landed after
last light and when he had flown in cloud.
T he combination of the two factors of a pilot being
'pressed for time' and su bsequently being caught in
deteriorating weather is a common one in the
circumstances leading to fa tal accidents, particularly in
private flying. In the case of this accident it has not b een
possible to establish whether the combination again
existed but the clear message from the known
circumstances leading to the accident suggest that it
happened in this way e
3
�Wear your seat belt
the right way
Seat belts are required to be worn during certain phases of flight, so most people do. But for full
value you have to wear the belt the right way.
Ten years ago, all new types of a ircraft imported into
Australia were required to be fitted with seat belt systems
that restrained the upper part of the body. In 197 1, the
requirement was extended to types already in Australia
for which installation schemes existed a nd in 1973
Australia became one of the first countries in the world
to implement a plan to fit upper body r estraint harness
to the front seats of all general aviation aircraft. British
a nd American authorities have since introd uced parallel
requirements.
The effect of this harness on accident statistics has not
yet been fully assessed, but there is no doubt that it has
been beneficial. I t seems however , that in at least some
cases the full benefit has not been obtained because the
harness was either improperl y fitted, or was incorrectly
adj usted.
Lap belt position
For the lap belt to be fully effective it needs to act on
the bas ic structure of the human body and is best
positioned on the hip bones, thus tra nsferring the belt
loads to the bony skeleton of the body and holding it
firmly in the seat. Impact loads transmitted by a poorly
positioned belt can cause serious internal inj uries. Most
modern aircraft are so equipped that the lap belt is
always correctly positioned but on older a ircraft it may
be necessary to adjust the anchorage points to achieve
the o ptimum positioning.
Buckle position
-
4
Buckle by your side
Belt not twisted
Fastened firmly
The positioning of the buckle on lap-sas h belt
combinations should be such that the sash crosses
diagonally from the outboard shoulder to a n attachment
point as low on the inboard hip as possible. This diagonal
configu ration places the body's centre of gravity inside
the triangle formed by the sash and lap belt. The body
is thus prevented from rolling out upon forward impact.
P ositioning the buckle towards the front of the bod y
increases the possibility of 'fallout' fro m the sash as well
as the risk of injuries caused by the buckle itsel( It also
has the undesirable effect of pulling the lap belt u pwards.
L ater style seat belts have the buckle position fixed, but
on aircraft with a n adjustable belt attached to the buckle,
the belt should always be adjusted to ensure the buckle
is a t the side of the hip - not across the stomach.
theslackis taken up, but then muststopinalesserdistance
than with a properly adjusted belt. Thus to minimise the
risk of injury the seat belt must be fas tened firmly.
Inertia reels
G t;nerally, inertia reels are essential if the pilot is to
have unrestricted access to the full movement of all
controls while maintaining the protection of upper body
restraint. The additional cost of an inertia reel is
relatively insignificant when the advantages over a fixed
three point harness a re considered. Ensure that the
inertia reel is operating correctly by removing any twists
from the shoulder strap and checking its functioning with
a sharp jerk on the be! t.
Loose clothing
On aircraft fitted with a full shoulder harness of the
type which has a buckle secured in the locked position
by a lever and a spring ball, pilots should ensure that
loose clothing cannot catch the lever and unlock i t,
particularly during negative 'g' manoeuvres. When
flying such aircraft pilots should wear short-sleeved or
close-fitting shirts.
Fastening your seat belt
Firstly, ensure the buckle of the lap belt is by your
side, not across your stomach.
Next make sure the s traps are not twis ted , then
fasten t he belt.
Now tighten it - as firmly as possible, a llowing for
comfort.
Remember - try to position the belt below your
stomach and the buckle right a t the side of or below
your hip joint. This will help to avoid injury caused
by compression of the abdominal area in the event
of an accident.
Think of your seat belt as your life belt ... and
wear it the right way e
Effect of slack
Tests have shown that if a seat belt is slack on impact
the deceleration fo rces acting on the body are grea ter than
those affecting the aircraft. The body keeps moving until
5
�Are you ready for take-off?
The pilot of the PA28-235, shown below and opposite, certainly was not! While taking off from an
unsuitable area, the aircraft struck a parked car. The pilot was fortunate to escape serious injury.
In the period J 970-1975 inclusive, 249 Australian
aircraft were involved in take-off accidents. Thirteen of
t hese were fatal and altogether 27 people were killed in
t hem. These l 3 fatal accidents represent 11 per cent of
the total fatal general aviation accidents that occurred
during the six year period.
By comparison, acc ident statistics released by the
National Transportation Safety Board in the United
States, show that in the period from 1970 to 1974, takeoff accide nts represe nted 12 per cent of all fatal general
aviation accidents in America.
A feature of t he general aviation ta k€-off accident
situation is the high ratio of fatal accidents to total
accidents. Both in Australia a nd America, the ratio of
fata l accidents to to tal accidents in the take-off phase, is
more than twice the ratio of fatal to total accidents
during approach and landing.
About half the Australian accidents were simply the
result of inadequate flight prepar ation - a disturbing
situation because the pilots concerned could have ta ken
time to a nalyse the condi tions a nd study the various
fac tors affecting the take-off before their aircraft left the
gro und. This does not just mea n tha t ta ke-off accidents
a re attributable to negligence and carelessness on the
part of the pilot. R ather in simple terms it means that
the accidents occur because pre-flight preparation is not
put into its proper perspective - that the solution to the
problem lies in good pre-flight planning habits, better
aware ness of the. potentia l hazards, a nd an apprecia tion
of the capabilities and limitations of t he aircraft type.
6
Tradi tionally, pilots tend to emphasise the pla nning of
the en route approach and la nding phases of their flight ;
they study the weather at the destination, the route to be
ta ke n, the en ro ute an d terminal facilities, applicable
altitudes, the en route weather, and fuel consum ption,
but very often too li ttle thoug ht and p repara tion is given
to the actual take-off.
ln a n attempt to ascertain whether the problem
existed 'across the board ' in general aviation, or
wh ether it was endemic to particular types of operations
a nd/or pilot groups, we programmed our computer to
disgorge the relevant data. This covered all types of
accideqts in all categories of general aviation flying that
had occurred between the tim e power was appl ied for
take-off a nd th e first power reduction after take-off.
Records of hours flown in the various kinds of flyi ng were
factored into the data to obtain a n approximate number
of take-offs against types of operations a nd classes of
pilot lice nces. The results obtained were surprising to
say th e least!
The least number of take-off accidents occurred in
flying training. The rates were about the same for dual
and solo training and were extremely low - one
accident per half-million take-offs. Flying training thus
accounted for only about seve n per cent of t he take-off
accidents.
The next lowest rate was in charter/commuter type
operations flown by commercial pilots. This group
accounted for about 12 per cent of the take-off accidents
at a ra te of one accident per 60 OOO t a ke-offs.
Agricult ural flying was the second worst grouping,
and accounted for 26 per cent of the accidents a t a rate of
one per 40 OOO take-offs.
T he doubtful honour of the highes t rate of take-off
accidents went to private/business operations flown by
both private a nd commercial pilots. Privat e licence pilots
flying in p rivate/b usiness operations were involved in 39
per cent of the take-off accidents, whilst commercial
pilots were involved in 12 per cent. The frequency of
take-off accidents in this grouping was one per 20 OOO
take-offs - a rate no less than 25 times more frequen t
th an for student pilots engaged in solo flying training!
For those among our readers who are mathematicia ns, the m issing fou r per cent of the acciaents
involved pilots without any licence, or fell into some
category which became insignificant in the overall
picture.
Private and commercial pilots involved in private/
business oper a tions accounted for 123 of the 249
take-off accidents. They were involved in 42 collisions
wit h objects during take-off, J 1 stalled, 21 had problems
with engine operation, l 1 over-ran, 13 ground looped, on
seve n occasio ns t he landing gear collapsed, and there
were 18 other accidents of m iscellaneous type .
The real significance of these figures lies in the
circumstances in which the accidents occurred. Of the 42
collisions, nearly all were with objects aligned with the
take-off path and occurred because the strip used did not
meet t he b asic requirements of an authorised landing
a rea - no obstructions on or over the landing area. H alf
the engine problems were associated with fue l
management, and mainly involved water in the fuel
and/ or insufficient fuel. Six of the ground loops occurred
because the pilot selected an unsuitable take-off path. 1n
all, at least half the accidents in this group could have
been prevented before the pilot entered the cockpit - to
put it in a nutshell, by giving a bit of attention to the j ob
in hand.
So next time you call 'ready' at a controlled
aerodrome, or give yourself a take-off clearance at an
uncontrolled aerodrome or authorised landing area, be
sure you have considered all the factors which could
j eopardise the safe ty of your aircraft and its occupants.
Ask yourself have you :
• Properly refuelled your aircraft?
• Made sure it is safe for flight ?
• Checked the suitability of the take-off area?
• Checked that the load is within limits - and is tied
down ?
• Considered the wind, weather and density height?
• Ensured there is adequate fuel on board and selected
the correct tank?
• C hecked for carburettor ice?
• Mentally prepared yourself to deal wit h any
emergency that could turn a simple take-off into a
disaster?
To sum up - are you r eally 'ready' for take-off?
7
�An accident report revised
Althoug~ this article concerns .a heavy multi-jet transport aircraft, the factors that led to the accident
are applicable to all IFR operations.
Aviation Safety Digest No 93 contained a condensed
version of the National Transportation Safety Board
(NTSB) report concerning the crash of a Boeing 707 on
final approach to Pago Pago International Airport.
About 18 months after the release of the NTSB report
the Airline Pilots' Association in America petitioned the
Board to reconsider the probable cause of the accident.
As a result of the petition, the Board reopened the
accident investigation because of knowledge gained
through other accidents after the original investigation.
The aircraft's flight data recorder (FDR) data the
cockpit voice recorder (CVR) data, and the ai;craft's
engineering performance d ata were re-evaluated
extensively to determine more concl usively the effect
of the existing e nvironmental conditions on the
pilot's ability to stabilise the a ircraft's approach profile.
Following the re-investigation the NTSB released a
revised r eport which su pe rsed es and replaces the original.
The aircraft was making an ILS approach a t night to
a runway equipped with high in tensity lighting, a
medium intensity approach light sys tem and a two-bar
VAS I. The approach was over water until fi ve kilometres
from the runway threshold. About three kilometres from
the. thr~shold the approach path crosses Logotala Hill,
which 1s 399 feet above mea n sea level. The terrain under
the approach p a th slopes downhill from Logotala Hill to
the runway.
The aircraft struck the gro und 1200 metres short of the
runway and was destroyed by impact a nd fire. Of the
101 occ upa nts only five survived the accident and one
of these, the third officer, died la ter.
Tests and research
Flight recorder data/aircraft performance data
analysis
Measured values of the flight d a ta recorder pa rameters
were analysed along with engine th rust values
de~ermined from a spectrographic study of the cockpit
vmcc recorder tape a1id the a ircraft ma nufacturer's data
on p erforma nce. The purpose of this analysis was to
determine the magnitude of the wind s along the flight
pa th and to construct a flight profile which would relate
th.e aircraft's p~s ition during the final minute of flight
with the ILS ghde slope and th e corresp onding VASI
indication.
Determination of winds encountered
The aircraft's performa nce capability fo r a given se t
o'. conditions (including weight, configuration, thrust,
a1rspeed, a nd a ltitude) is d escribed by a sp ecific plot of
vertical speeds versus longitudinal acceler a tions. When
the values for the aircraft's r a te of altitude ch a nge and
8
rate of airspeed change at a given instant were not
compatible with the calculated theoretical performance
capability, the differences were a ttributed to external
'.orces on t?e aircraft which were produced by changes
m the vertical and horizontal components of the wind.
Although the total effect of the wind could be
d etermined by these analyses, the exact combina tions of
vertical and horizontal wind components which the.
aircraft encountered could not be determined precisely.
The thrust which would have been r equired for the
aircraft to have achieved level flight with a constant
indicated airspeed was also calculated for each of the
environmental condi tions encountered.
Determination of flight profile and relationship
with ILS glide slope and VASI indication
The flight profile of the aircraft, i.e. its altitude versus
dista nce from the runway thres hold, was determined for
th e las t minu te offligh t using airspeed and altitude values
from the FDR. The values were used both uncorrected
and corrected for the apparent errors evident fro m
impact site elevation and CVR callouts. The calculations
were p erformed assuming both a 15 knot constant
headwind a nd a headwind which varied b e tween zero
a nd 35 knots (the maxi mum wind speed indicated in
me teorological reports) in accordance wi th the wi nd
acceler ations determined in the described wind a nalysis.
Analysis
T~e captain occ~pied the left hand seat and was fl ying
the aircraft. T he third officer acted as co-pilot b eca use
the first office r had laryngitis. The first officer occupied
thejumpseat.
Th~ CVR readout and an interview with the co-pilot
esta blished that the runway was in sight wh en the aircraft
was about 15 kilometres from the runway threshold. The
co-pilot commented five times during t he approach, after
the aircraft was within 14 kilometres of the runway
~hr~ shold, tha t he had the runway or the ru nway lights
m sight. There was no indication that a ny of the
navigational aids or the aircraft instruments were faulty.
The aircraft descended about 500 fee t below th e
published minimum glide slope intercept altitude of 2500
feet before the glide slope intercept point was reached .
This placed the aircraft 180 feet below t he final approach
fix (FAF) altitude of2 180 feet. These altitudes a re
confirmed by a CVR com men t, ' Two t housand', made
a bout 1.5 secon ds before the FAF callout. T he Board was
unabl e to d etermine the reason for this d eviation from
a pproach procedures.
A.t F ~F passag~, i.e. the seven DME fix, the co-pilot's
nav1gat1onal receiver selector switch should have bee n
ch anged from the VOR position to the ILS position;
however, this was not accomplished. If the change had
been made, as good practice would indicate, the co-pilot
could have monitored th e a pproach more efficiently and
his navigational d isplay would have been ready for
crosscheck by the capta in or crossover in case of failure
of t he cap tain's instruments.
As the aircraft approached the glide slope, it continued
through a nd above it as the captain sta rted the descent.
The glide slope was intercepted as the aircraft passed
through about 1000 feet. The airspeed during this time
varied a fow knots above and below 160 knots.
From this point on during the approach, the FDR
information showed that th e aircraft fligh t path was not
compatible with the aircraft performance which would
be expected in stable a ir . T he difierences can be
attrib uted to external fo rces acting upon the aircraft, such
as wind changes or rain drag. Analysis has shown that
maximum density rain could produce an increase in drag
forces which wou ld equate to a - 600 fpm change in
descent rate. Statements by the co-pilot and the surviving
passengers however, refute any claim that the aircraft
encountered such heavy rain before impact. Therefore,
the difference between expected a nd recorded aircraft
performance was more likely caused by the winds.
Analysis of the wind changes needed to produce the
recorded aircraft performance
T he FDR data analysis indicated that the aircraft
encountered gusty wind conditions with a predominantly
increasing headwind and/or an updraft about 50 seconds
before impact. T he influence of this wind condition
p ersisted for about 25 seconds. The Board believes the
windshear was caused by the outflowing winds from the
rains torm over t he airport as they were affected by the
upsloping terrain around L ogotala H ill. The windshear
was evident by a sh arp increase in airspeed and
shallowing of the descent path resulting in the aircraft
going above the glide slope. The airspeed at th is time
was still about 160 knots. The sound spectrogram of the
CV R showed that a t this time the thrust was reduced,
apparently lo correct the high and fast situation.
As the aircraft passed Logotala Hill, it appare ntly
came out of the increasing headwind or updraft condition
and th e positive performance effect was los t. I t then
encountered a wind wh ich produced a small negative
performance effect. T he thrust was well below that
normally needed for a stabilised approach and, about
16 seco nds before im pact, the aircraft started a rapid
descent of abou t 1500 fpm.
It was concluded that th e captain recognised the initial
effect of the wi ndshear con dition and acted to correct the
aircraft's flight profile by reducing thrust, b ut he did not
recognise the second effect as the windshear condition
changed. Consequently the aircraft with low thrust
responded to the changing wind by developing a high
descent rate. T he captain had at least 12 seconds in
wh ich he could have taken action to arrest the descent
in time to prevent the accident. Adequate thrust was
available but the necessary pitch atti tude a nd thrust
changes were not made, indicating that the flight
crew was not aware of the high descent rate and the
impending crash.
When the sink rate increased, the captain was
probably looking outside the aircraft and not Hying by
reference to the flight instruments. At about this time
the aircraft was over a n area devoid of lights
(known as a ' black hole'), a heavy tropical rainstorm was
over the airport and moving towa rds the approach end
of the runway, and the first officer had called the runway
in sight.
T he circumstances of several other accidents which
have been investigated by the Board indicated that the
transition from instrument flight to visual reference for
vertical guidance is the most critical portion of the
approach, particularly if the transition is initiated
prematurel y. Dynamic changes to the aircraft's Hight
profile often go unrecognised. In this accident the heavy
rainshower ahead of the aircraft probably caused visual
cues to diminish to the extent th at the increased sink rate
would have been extremely difficu lt, if not impossible,
to recognise.
T he VASI was operating during this approach but
there was no way to determine if the crew could have
seen it continuously because of the heavy rainstorm that
was moving across the airport. As the rain moved
towards the aircraft's approach path it most likely
obscured each pair of runway edge lights progressively
until the VAS I disa ppeared from the flight crew's
sight.
It is likely that the flight crew did see and use the VAS I
at some time during the approach, particularly after the
co-pilot's report that the aircraft was ' . .. a little high'.
T he most likely reference for his statemen t of the
aircraft's vertical position would have been the VASI ,
because he had not changed h is No 2 naviga tion al
receiver selector switch to the I LS frequency. Therefore,
IL S information would not have been displayed on his
instruments. T o obtain ·this information , other than
visually, he would have had to look 'cross-cockpit' at th e
captain's instruments to determine that the aircraft was
high. In the last few seconds, the co-pilot would have h ad
to look back into the cockpit to ascertain that the aircraft
was at the minimum altitude at an airspeed of 140 knots
and advise the captain.
9
�CAP: Okay, mileage check
CPT: Okay, ya got eight miles
CAP: Okay I have the runway In sight
CPT: We come up on two thousand on the radio altimeter
2800
2600
2800
CAP: A bit bouncy out here
CAP: Seven miles DME
Sound of engine power increase
CAP: Get down here you •• ••
CPT: Seven miles and the altimeters check
- Soundol
further increase
In engine power
2400
2200
2000
- · - GLIDE SLOPE
ADO: That's Charlie
PAPP: And we have a bad rain shower here. I can't see
them from my position here
ADO: We're five DME now and they still don't look bright
PAPP: Okay, no other reported traffic. The wind Is 030°
at 20 gusting to 25. Advise clear of the runway.
ADO: 806 wllco
CAP: Keep your eye on it. I'll stay on the gages right here
CAP: Keep your eye on It
Sound of wiper
motors begin
- -......._.._._.:;_CAP: Flaps fifty
1200
-DESCENT PROFILE
CAP: Captain
1000
800
CPT: Co-pilot
-----PROJECTED ACTUAL FLIGHT PATH
2200
PAPP: See the runway lights?
-
1600
-;;::::::::
.
PAPP: Pago Pago approach
600
•
400
AIRCRAFT INITIAL CONTACT WITH
TREES 25 FEET ABOVE GROUND LEVEL
2400
ADO: 806, we're still getting your VOA, the ILS, and the
lights are showing
1800
1400
2600
PAPP: Clipper 806. It appears that we've had a power failure
at the airport
ADO: Co-pilot transmitting to PAPP
2000
MIDDLE MARKER
(WRECKAGE SITE)
1800
1600
CPT: You're by Logotala
CAP: Let me know when you got the runway
I
CPT: Now you have the runway
CPT: You're a little high
Electric Stabilizer Trim
Actuation sound
CPT: 150 knots
CPT: You're at minimums
CPT: Field In sight
CPT: Tumto
your right
CPT: 140 knots
SOUND OF
IMPACT
200
-
200
13500
12000
Even had the ·c aptain. been ·observing the_VASI as the
aircraft "des"c ended below the glide pa th, his attention to
.the· indications and his reaction to ari unsafe red/red
signal ~ould have had to.be rapid ·and_decisive in order
· to ·prevent impact:
·
.
.
· The flight prqfile analysis showed that the aircraft was
abou t 178 (eet above the trees and descending at 25 feet
per .secorid when th.e re.cl/ red V ASl ~ndication should
havt; b~eri seen· by the crew. Allowing one second for th~
captain to introduce a control movement, tl~c a ircraft
would •then have lost about 80 feet" of altitude before the
· de.scent ~a; arres ted. T his a~sumes a _very 'positive
level-off manoeuvre where "th~ aircraft is rotated to a ·1.5g.
load fact9r. The. captain would ha.,;e h a~ to recognise and
start responding !O che situ.atio\1 within about 2.5 seconds
. of the red/ red· V ASl." presentation in '?rder tq miss the
trees by.about 235'feet. Slower. recognition time or a less
positive l~vel' off manoeuvre would l:iave restilted in
i~pact witj1 the trees. The-Board believes _that 2.5
second s is_ marginal for the perception of the change in
VASI ·indications and -the initiation of appropriate·
'response b'y ihe captam. .
· .
.
·
The Board considered another factor could .h ave
su pported the captain's vis"ual indications ·t hat he heed
not apply power to reac!i tlie fU!)Way or tO arres t a high
rate of descent. The· heavy rainstorm which was moving·
towards the ai rcraft could have caused a shortening of
tl~e pilot's visual segment - that distance along the
su rface visible to the pilot over the nose of the ·aircraft.
This can produce the illusion that the horizon is moving
10500
9000
7500
lower and , as a result, is often misinterpreted as an
aircraft pitch change in the nose-up direction.
The natural response by the pilot would be to lower the
nose or to decrease, not increase, power.
While conceding that the environmen tal
circumstances at the time of this accident were
unfavourable, the Board concluded that the accident
could have been avoided had the crew recognised, from
all available sources, the onset of the high descent rate
and taken timely action. The Board is, therefore,
concerned about crew procedures relative to altitude
awareness and required callouts. If the crew had been
completely aware of the aircraft's altitude, they should
not have accepted a glide slope intercept 500 feet lower
than the published altitude; they should not have
accepted an altitude 180 feet lower than that altitude
prescribed for the F AF crossing; and the pilot not flying
should have made altitude warning callouts. The co-pilot
did make an altimeter check about 2.4 minutes before
impact, but he said nothing about actual altitude. About
three seconds after the co-pilot's comment, th e captain
made an unintelligible remark which might have been
a recognition of the a ircraft's lower-than-prescribed
.altitude because, five seconds later, the sound of a power
increase could be heard on t he CVR.
Perhaps even more important t han altitude awareness
in this accident was awareness of increasing sink rate.
Company procedures required that the pilot not flying
the aircraft call out sink rate when it exceeded 800 fpm.
An a nalysis of the ap proach to Pago Pago showed that
6000
FEET
AMSL
1400
1200
1000
800
600
400
RUNWAY
SURFACE
(301 MSL)
0
RUNWAY
THRESHOLD
the 3.25 degree glide slope would require a d escent rate
slightly less than 800 fpm with an indicated airspeed of
135 knots in zero wind conditions. In this case, 135 knots
was the reference speed (Vref) for the approach. Using
the company proced ure of adding only half the steady
wind veloci ty to V ref, the required d escent rate would
be Jess than the rate required for zero wind since the
ground speed would be affected by the total value of the
steady wind veloci ty. Any additional speed margin to
compensate for wind gust velocity would have had the
effect of increasing the ground speed and thereby
increasing the required descent rate. Such rates however,
would still be less than 1000 fpm even with a 35 knot
gust margin.
The captain was attempting to maintain an approach
speed of 150 knots. If the anticipated headwind
dissipated to zero, the descent rate required to maintain
position on the glide slope would have been 880 fpm, still
less than the 1000 fpm maximum. Nevertheless,
according to procedures, a callout should have been
made which might have alerted the captain that the
actual winds differed from those reported.
The FDR data showed that the aircraft's rate of
descent increased to about 1500 fpm at least 15 seconds
before impact. Again, there were no callouts and the
evidence indicated that the captain did not recognise or
react to this increased sink rate in a timely manner. The
Safety Board believes that, had he done so as a result
ofa callout by one of the non-flying crew members, the
accident could have been avoided.
The Board also believes that flight instruments are
more reliable indicators than the senses of the pilots,
especially during that portion of the approach when the
aircraft is close to the ground and when the visual cues
are sparse or diminishing. In severe windshear
conditions, the flight director must be used in
combination with other flight instruments such as the
raw data indications. In the final 15 seconds of this
approach, the rate of descent must have averaged
considerably more than the 1000 fpm recommended
maximum and the raw data glide slope needle must have
shown that the aircraft passed through, then below, the
glide slope.
Probable cause
The National Transportation Safety Board determined
that the probable cause of the accident was the flight
crew's late recognition of, and failure to correct in a
timely manner, an excessive descent rate which
developed as a result of the aircraft's penetration through
destabilising wind changes. The winds consisted of
horizontal and vertical components produced by a heavy
rainstorm and influenced by uneven terrain close to the
aircraft's approach path. The captain's recognition was
hampered by restricted visibility, the illusory effects of
'black hole' approach, inadequate monitoring offtight
instruments, and the failure of the crew to call out
descent rate during the las t 15 seconds offlight e
11
�r:
On the following afternoon the pilot and passengers
boarded the aircraft for th e return flight. When he tried
to star t the engine, the p ilot fou nd the battery was once
again fiat. H e checked the parking brake was on, the
ignition was off and the throttle was set about one
centimetre open for starting. L eaving the cockpit he
positioned the propeller at the top of the stroke then
returned to the left h and cabin door and turned the
ignition to 'Both' .
The three passengers were still on board the ai rcraft
when the pilot sw ung the propeller and the engine
s tarted. T he aircraft immedia tely started moving fo rward
and the pilot ran to the left ha nd door a nd struggled into
his seat. H e was unable to stop the aircraft before the
left wing struck a small shed, causin g the aircraft to veer
sh arply left. The propeller slashed through a barbed wi re
and picket fence and some old corrugated iron ga ble
markers.
After the engine stopped the uninjured occupants had
to vaca te the aircraft b y the righ t h an d door because the
buckled wing hadjammed the left door shut.
Subsequent inves tigation of the accident revealed that
the pilot had been shown, some time d uring his training,
how to hand start an aircraft but he was unfamiliar with
the applicable safety precautions. T he brakes were
serviceable and it was concluded that because of his slim
build, the p ilot had been unable to apply th e parking
brake firml y. Wheel ch ocks were not used during th e
ha nd sta r t.
In a more recent accident in Western Australia, the
pilot of a no th er Cessna 182 suffered severe injuries and
the four passengers on board the aircraft were fort una te
to escape serious inj ury when it bolted after the pilot
hand started the engine. Inadequate provision had been
made to prevent the aircraft moving forward.
Would you swing the propeller
this way?
This article describes the correct way to handstart an aircraft; however, careful consideration
should be given to the need to do so if a pilot is
confronted with this situation. Ensure that all
possible alternatives such as obtaining engineering
assistance, using another aircraft, delaying the
flight, etc., have been considered before
undertaking this not-so-simple procedure. It may be
the first link in the inevitable chain of events
leading to an accident!
12
The pilot of a Cessna 182 h ad h ired an ai rcraft from a
trai ning school at Essendon for a pleasure flight, staying
over-night at a Western V ictorian town. Before departing
from Essendon with his th ree passengers the pilot had to
ha nd start the aircraft because it had a flat battery a nd
th ere was no spare available.
On completion of the travel flight which included a
delay on the grou nd en route because of weather, the
pilot made one local flight. The engine was successfully
started on two occasions using the starter motor as the
battery h ad recha rged suffi cientl y in flight. The aircr aft
remained over-ni,gh t at the country aerodrome.
Despite the rcliabili ty of modern aero engines, pilots
may from time to time be faced with the need to ha nd
start an engine because of a flat battery or a
malfunctioning starter motor. I n many late model
ai rcraft however, the propeller may not necessarily be
positioned on the crankshaft for conveni en t hand
swinging and, ifth e pilot has not been properl y trained
in hand starting techniqu es the stage is se t for di saster.
In the case of a n aircraft that always has to b e sta rted
b y swinging the propeller, pilots accep t the correct
starting procedure as an integral part of the overall
operation a nd proper safety precautions are observed as
a matter of course. But for those pilots who normally start
aircraft by ' turning a key', it seems that, either through
lack of proper instruction, ignorance of procedures or
even p lain carelessness, hand starting a ttempts result in
disproportiona tely more accidents than for pilots
regularly fl ying aircraft types that have to be started by
hand every time.
The following summary of procedures and
considerations covers t he major poin ts in the normal
ha nd s tarting sequ ence. While not ex h austive, the list
provides for most light aircraft engine installa tions:
Preparation
..
•Firmly apply the parking brake;
• chock the wheels;
• have the pilot's seat occupied by a qualified pilo t or
approved person;
•remove or tuck away tic, remove watch, loose jacket
or coat, any rings - in fact a nything that might
become en ta ngled in the propeller or hinder
movement;
• es ta blish clear communications with the person a t the
controls.
'
Practising the hand start
•Set the engine with magnetos off, fuel off, mixture idle
cut-off and throttle closed;
• face the plane of the propeller;
• ensure the ground is firm and no t slippery;
• place one or both hands on th e trailing edge of one
of the blades;
•stand so that the swing will tend to carry the body away
from the propeller;
• position the propeller blade for a comfortable swing
against com pression;
• make a smooth stroke th rough co mpression, pulling th e
hands down and away as the movement is completed,
and simultaneously stepping back from the propeller
arc;
• select the most favourable position of the propeller a nd
practise the hand swinging techniq ue best suited to the
particul ar installation.
Starting the eng ine
•Fuel on;
• ba ttery master switch on;
• prime the cylinde rs - throttle, mixture and b oost
pump as required;
• throttle closed, then set for a normal start - but n ot
open more tha n five mil limetres;
• throttle friction nut tight;
• magnetos as recommended for handstarting;
• swing the propeller using the procedure practised.
It is essential that the propeller always be regarded as
live - n ever stand in, or pass through, the propeller arc.
It must also be remembered that with a n impulse
magneto even the slowest movement can cause a primed
cylinder to fire. Therefore even when turning the
propeller slowly for correct positioning, the techniques
adopted when actually attempting a start must be used.
In a n emergency, wh en the engine has to be started
withou t a pilot or an approved person at the controls,
the following considerations sh ould be observed:
e H ave the passengers leave the aircraft- better to brief
them properly a nd have them board again after the
engine has been sta rted than risk having them in a
runaway a ircraft;
•align the ai rcraft so that it cannot become airborne being stopped by a dicch is preferable to having the
aircraft become airborne unmanned;
• consider a ttach ing ropes to t he chocks so they can be
pulled clear of the wheels from inside the cockpit;
• remember that the throttle need only b e partially open
to give enoug h power for the aircraft to j ump the
chocks;
• co1i.sidcr attaching a line from some fixed point to the
th rottl e to ensure the throttle wi ll be closed if the
aircraft moves forward ;
•consider tethering the aircraft to some heavy or fixed
object using the rear tic-down point, but do not forget
to undo it!•
13
�Good show all round
Index to Aviation Safety Digest
1 -100(1953-77)
References in this index are to articles, rather than to specific mention of the subject on particular page!i·
Where the reference is in italics, the article is a general one on that topic, otherwise the reference 1s
to an occurrence or pilot contribution in which the subject was involved as a major factor.
Listings are in the following form: D27-3, 25, 29.
.
The number following D is the Digest issue, the numbers following the hyphen are page numbers m
that issue where the reference articles begin. The example given refers to Digest 27 and articles beginning
on pages 3, 25 and 29.
An Electr a freighter had been loa d ed at Melbourne for
a n early m orning flight to L a unces ton. The loa d in th e
a ircraft was m os tly conta ined in nine cargo igloos and
the total weigh t of the cargo was documented as 13 658
kilogrammes. T h e load sh eet for t he fligh t in dicated a
ram p (taxi-i ng) weight of 45204 kg; the m axim um
permissible r a m p weigh t is 51390 kg.
A t 03 18 hours E ST the aircraft taxied from th e freight
terminal for the d ep a rture run wa y. While taxi-ing, th e
fligh t cr ew ch ecked the o n-board W eig h t/CG computer
in a ccorda nce with t he cockpit checklist. This computer
calcula tes gross weig ht a nd centre of g ravity from the
h ydraulic pressures in th e three under carriage oleo s tru ts .
The rea dings o btained were corrected using the d ata
cor rection card kept on boar d th e aircraft and the crew
reach ed the conclusion th a t th e a ircr aft wa s about
1600 kg above the d ocumcn ted weight. T h e cap tain
elected to re tu rn to tlie han gar a nd advised ATC
accordi n gly.
After the El ectra had been loaded th e load ing crew
had proceed ed to other d uties. The sen ior clerk in charge
of th e loading went to insp ect som e o ther igloos a nd
discovered that the wind ha d blown away the m a rking
tabs from th ree of the m. H e a rra nged to have them
r eweigh ed a nd on completio n of this task fou nd them to
be s ubs tantia lly h eavier tha n r ecords fr om th eir p r evio us
weig hing showed . T he r eweig hing was cond ucted on a
set of m ech a n ical scales.
The senior cler k realised tha t the igloos in question had
been weighed initially on the a u toma tic electronic scales
a nd tha t fo ur of the ig loos on board the E lectra had a lso
14
been weig hed on those scales. S uspecting a n error in the
weight of t he load on the d epar tin g a ircr aft, he contacted
M elbourne opera tion s to have th e aircraft reca lled.
M elbourne T ower advised the flight cr ew w ho had
a lready elected to return to the ha ngar for a check of
th e loading . R eweighing the aircraft load o n the
m ech a nical scales revealed the total weight to he nearly
2000 kg mo r e tha n d ocu men ted . T h us, though the
maxim u m tak e off weight h ad no t been exceede d, the
zero fu el weigh t was 664 kg a bove the li mi t and the·
a ircra ft would h ave been overweigh t for la ndin g.
S ubsequent investigation of the a utomatic weig hing
sys tem uncovered a fa ult in one row of the roller
conveyor. A clam p was missing a nd had a llowed the
rollers to move sideways slightly. T hey were resting on
th e base of t he scal es so that instead of th e full weigh t
of the load being o n the weig hing pla tfor m , part of it
wa s su p ported otherwise. Cons eq uen tly t he indicated
weight was less than the actual weight.
It would be pure conj ectu re to tr y a nd estimate the
du r ation of the fau lt existing in the scales or the n um ber
of a ircra ft which migh t have been loaded incorrectly as
a res ult. Fortu n a tely on this occasio n the air craft
involved was equipped to detect s uch a n error in the
loadi ng a nd the diligence of the fl igh t crew in so d o ing
is to be comme nd ed.
H ad this incid e n t involved a n aircraft no t fit ted with
a W eigh t/ CG com pu ter, the promp t actions of the senior
loading clerk, a lthough ini tiated following a chance
even t, would have p revented a serious overload situation
bein g undetected •
Abandoned take-off. D1-24; D18-26; D44-9; D61-12; D71-1;
D85-10; D90-10, 16.
Acid spillage. D66-1 O.
Advertising. Claims of aircraft performance: 064-10.
Aerobatics. D8-23; D9-22: D10-17; 027-3, 27; D28-12; D33-9;
D34-19; 040-4; D47-5; D75-12; 0 76-12; 0 78-6; D81-10; D87-6;
D92-2.
Aerodromes. Licensed: 041-24 ; outback: 05-6; procedures at:
D49-13.
Aerosol cans. Danger of explosion: 0 89-28.
Aerotow. Gliding: D84-6.
Agricultural flying. D6-16, 24; D7-22, 23, 27; 08-5, 25, 27; D9-21,
23, 24, 25; D10-19; D11-22. 26; D12-19. 21, 22; D13-24, 26; 0 15-27;
D18-7; D20-18, 25; D21-18, 27; D24-8; D28-14, 22, 24; D30-7, 8;
D31 -26, 28; D33-23; D36-18; 0 38-1; D41-14; D42-12; D44-14;
D48-4; D50-14; 056-16, 26 ; D59-16, 25; D62-19; D63-17; D67-3,
5; D70-7, 19; D74-1 O; D88-16; D90-6; D94-26; and the Law: 0 44-19;
s ulphur-dust fires: 0 9-7; use of human markers in: 0 16-27.
Agricultural strips. D13-25, 27; D58-10; D86-19; 0 98-2, 9.
Airmanship. 048-14; 0 67-14 ; D78-28; 0 79-14.
Airsickness. 090-13 .
Airspeed. 0 26-20: D59-19.
Airways operations. 08-7; 085-6 - see also ATC, Flight service
and Controlled airspace.
Alcohol. D52-2, 6; D63-1: D77-20; D85-2.
Altimeter. 0 7-3; D13-12; D14-18; D17-22; D19-4; D21 -5; D23-4;
0 27-14; D45-24; 048-18; 065-14, 23; 068-28; D74-28; D78-1 ;
D80-22; 087-6, 28; 094-6.
Approach and landing accidents. 0 14-5.
Aquaplaning. 0 29-16 ; 037-16; 039-1; 0 53-14.
Asymmetric flight. D4-1; D6-17; 013-11; D17-7; 0 19-8; D21-24;
023-1O; D26-6; 027-6; 0 31-8; 0 36-16; 078-11: 0 90-20; 093-2.
ATC. 08-7; 0 20-14; 027-1 8; 034-1 ; D57-14; 077-17; 085-6.
Attitude. Aircraft: 01-13; D2-15; D42-15; 086-12; D92-20.
Autopilot. D21-14; 070-1 4; 0 90-26.
AutorotaUonal landings. D12-19; 025-28 s ee also
Helicopters.
Balance. - see Centre of gravity.
Basic aeronautical knowledge. D93-28.
Banner towing. 039-17 .
Birds. Damage by: 053-28; nests in aircraft: 083-21 ; strikes: 02-9;
D34-24; 038-6; 0 4 1-11; 049-5; 071-1; D87-6.
Blasting. Danger to low-flying aircraft: D81-28.
Brakes. D11 -27; 045-18; 071 -27; D91-28; failure: 085-10; 0 88-14.
Braking, reverse thrust: 031-7 .
Cable release. Gliding: 019-11.
Carbon monoxide. 0 23-26; 0 45-1 6 ; 051-13; 0 89-18.
Cargo. Dangerous: 014-8; 016-11; 0 21-21 ; 022-23; 0 37-13;
0 50-19; 0 52-21; 066-10; - see also Centre of gravity, Load and
Excess weight.
Centre of gravity. 07-26; D14-26; D25-17; D56-1; D86-12.
Circuit procedures. 0 97-14.
Cloud. D3-25; D5-24; D6-27; D16-16; D17-13; D18-28; D30-11;
D39-4, 18; D42-18; 052-14; 054-7; D55-2, 16; 057-18, 27; 066-4;
0 75-18' 26; D79-18; 080-2; D85-9; D87-16; D89-8; D91 -27; D94-2;
096-14; D98-2; collis ion with terrain: D12-15; 0 14-23; D16-15;
D18-20; D41-2; D43-1; 060-1; D65-1; D73-2, 8, 13, 17, 27; D74-1;
D77-10; D78-21; 079-2; D81-2, 6; D82-10, 19; 089-2; 09 1-16;
095-2; control loss in: D7-26; D9-14; D10-16, 22; D16-14, 16, 18,
25; D17-18; 020-10; 021-20; D28-8; D34-14; 037-1; D38-25;
D40-20; D41 -8, 16; 049-1, 16; 0 52-14; D68-1; D73-24; D75-2;
077-17 - see also Sensory Illusions and Weather.
Cockpit. Checks: D10-1 2; 016-9; 026-26; 034-6; D42-26; D66-12;
068-18; D86-16; 0 96-1 - see also Preflight checks. Design of:
01-5; liquids spilt in: 06-5; 027-25.
Collision. Midair: 05-16; D7-24, 27; D11-13; 020-6; 025-20;
027-18; 028-4; 062-6; 074-18; D75-28; D77-28; 0 98-5; on ground:
033-10; parachuting: 069-14; with animal: 070-24; with object:
01-23; D3-30; 05-24, 25; 06-10, 16, 17, 22, 25, 27; 08-5, 8, 12,
25; D9-14, 22, 23, 26; 010-19, 22; D11-22, 26; D12-19; D13-25, 27;
014-26; D15-22, 28; 016-26; D17-13, 21 ; D19-10; 020-18; D22-14,
15: D23-21; D31-24; D32-6; D34-22; D37-16; 040-3, 24; 042-18,
26; D44-14; D45-10; D48-1, 4; D53-2; 054-7; 057-16, 18; D58-1 ,
5, 10; D59-8; 061-1, 20; 062-2; D64-5; D65-24; 067-15; D69-5;
D71-1 ; D76-19; D79-18; 080-26; D83-6, 11; D84-16; 090-6, 10, 16;
D91 -11, 14; D92-27; D94-26; with terrain: D1-16; 07-22; D9-11, 25;
D10-10, 20; D12-15; D13-12, 25. 26; D14-23; D17-22; 018-4, 16,
20; 0 19-4, 11 ; D20-25; 022-10; D23-12, 24; D24-8, 13; D29-11;
030-11; D33-23; D35-5; 036-16; D41-2; D42-12, 13; 043-1; 045-24;
D48-18; D49-6; 050-2, 16; D51 -9; D53-7, 12; 054-2, 18; 060-1;
063-1, 9; D65-1 ; D67-24; 068-20; D71 -10; 072-1, 10; D73-2, 8, 13,
17; D74-1, 10; D78-1 , 21; D81-2, 6; D82-10. 19; D87-6; 088-2;
D89-2: 091 -1 6; 093-2; D94-6, 10, 14; D95-2, 6; D98-20, 24; with
water: 07-8, 15; D20-16; 043-8; D73-27; 074-8; D77-10; D79-2;
D80-22; D85-2; D94-22 - see a lso Ditching and Wire strikes.
Communications. 0 19-3, 15; 0 32-1; 035-8; 038-28; 040-26;
047-19, 27; D49-13; 052-1 3 ; D57-14 see also Radio
procedures..
15
�Compass. Error: 031-22 ; D44-20; D72-21; interference: 022-20;
027-26; 028-23; 055-20, D69-22; 097-28.
Control. Crossed: D20-5; D59-27; difficult D46-11; D52-1 4;
D60-16; D61-25; failure: D23-7, 14; D27-12, 22; D33-16; D51-1;
D54-14; D65-26; interference with: D6-23; D29-1 ; D34-1 O; D38-26;
D54-2; D61-6; D62-18; 068-24; D80-6; D89-13; D92-28; loss of:
D2-14; D3-12; D5-11; D6-8, 12; D7-26; D8-14, 17, 21; D9-14, 20;
D10-12, 16, 22; D11-16, 21; D13-21; D15-7; D16-14, 16, 18, 25;
D17-7, 18, 19; 018-19, 30; D19-24; 020-8, 10, 12; D21-20, 24;
D22-8, 24; D23-8; D25-17; D26-24; D28-8; D30-8, 10, f f D31-8;
D32-10; 033-24; D34-14; D35-18; D37-1 ; D38-25; D40-6, 20; 041 -8,
16; D43-20: D45-18; D46-12; D49-1 , 16; D51-1 ; D52-2, 6, 17; 053-2,
7; D54-25; D56-5; D57-1; D58-16; D63-5; D68-1 ; D73-24; D74-10;
D75-8; D76-8; D77-17; D80-6; D84-6; D86-8; D87-8, 20; D91-3; lock
left on: D62-14; D68-27; D90-16; use of wrong: D8-12, 13; D12-7;
D62-28; D70-16; 094-27.
Controlled airspace. 0 28-3; 031-13; 034- 1; 046-4; D69-22 also Penetrations.
Corrosion. D86-8.
see
fuel. 018-31 ; inflight: 07-5; D9-18; 033-14; D64-16; on ground:
039-23: D48-17; D50-21 ; 064-25; sulphur-dust: 09-7 - see also
Engine fire.
Firearms. Carriage in aircraft 026-27.
Flight planning. 042-5; 055-1 4. supplement; 057-17; 088-20;
097-20.
Life jackets. 092-25.
Flight service. Assistance: 08-7; 085-6.
Load. Agricultural: D13-26; D41-14; 056-26 ; shift. 023-8; 080-6;
loading: 011-21; 031-12; D56-1 - see also Centre of gravity,
Excess weight, etc.
Long distance travel. 0 5-5.
Food poisoning. 040-22; 0 51- 11.
Forced landings. 03-25; 06-22, 25; 07-5, 10; D8-21, 22 26; 09-25;
D10-21 ; D11-25. 26; D12- 18; D14-17; D17-26; D18-23; D21-22;
D23-18, 25; 024-1; 030-7, 16, 18; 034-8; D36-24; D37-24; D39-27;
D42-13; 043-4; 044-2; D45-12; 049-6; D50-14, 22, 26; D52-10;
054-23; 055-13; D57-8; D58-13; D59-1, 21, 22, 25; 065-28; 066-4;
067-7; D70-1, 16; 071 -17, 22; 074-14 ; 075-2; 076-22; D77- 1:
D78-11, 18, 24; 082-24, 26; D85-9, D86-2, 19; 087-2, 092-1 1, 14.
27.
Defect diagnosis. 023-22.
Fuel. Blockage: D89-24: contamination: 012-19; D14-17; 024-18;
026-22; 030-16, 035-14: 045-8. 27; 046-6; D64-28; 065-7; 091-3;
siphoning- 037-14; exhaustion: 0 1-20; 05-10; 021 -12; D27-4;
030-7; 039-27; 040-24; D42-26; 046-18; 050-26; 055-2, 16:
057-17; 059-21; D67-7; 081-24; D86-2; 088- 14; 091-22; leakage:
038-5; 079-16 ; mismanagement: 03-17; 06-25; D7-6; 08-21 , 22;
024-8; D28-14; 0 30-18; D36-18; 036-24; 037-24; 043-4; 050-14;
059-22; 065-28; 071 -17; 087-2, 26; 091-22 ; 093-16; planning:
0 37-9; poisoning: 090-27; systems: 043-6; 057-8; theft of· 059-21;
D98-27; use of wrong: 013-11; 018-9; 032-24; 043-27; 050-24;
054-22 ; 064-9; 074-14; 087-26; vents: 035-10; D59-4.
Descent. Uncontrolled: 021-14.
Fumes. In cockpit: 061-22; 077-1 .
Design modifications. Unauthorised: D32-22, 041-4 ; D62-19.
Gliding. D9-20; D15-28; 019-10, 11 : 021-26, 022-22; 027-22;
D33-22; 042-14: 054-11 ; D61-1; 062-2: 084-2, 6, 10, 14, 21 :
090-2.
Crash-landings. How to perform safely: 088-12.
Crew. Co-ordination: D30-18; D95-19; crewmanship: 05-3.
Crocodile. In cockpit: D66-27.
Crosswind. 053-18; 079-22; D88-9; D93-12; 097-10.
Damage. And subsequent flight: 0 35-25.
Decompression. D35-16: D37-19.
Directional control. Loss of: D3-11 ; D4-1 ; D6-22; D53-18;
D93-12.
Distraction. D77-28; D83-13, 18; D88-2; 094-6.
Glued structures. 032-20; 035-18.
Ditching. D5-10, 19; D7-6; D10-12; D16-20; 029-23; 033-6; D36-4;
D60-16; 080-16 ; D92-25 - see also Collision with water.
Go-around. 03-22; 08-12; 09-22; 012-7, 12; 013-25, 27: 017-7;
D18-30; 029-11, 12; D35-26: D36-16; D39-4: 050-2; 060-16; D65-8;
090-14; 098-2.
Door. Open in flight. 032-1 O: D63-21; D76-19: D87-8.
Gremlins. Accident causes: 069-19.
Downdraft. D3-22; D5-22; D6-9; D7-22; D14-13; D30-1; 034-12 :
D64-1 : D88-27: 093-24: D94-10 - see also Mountain wave effect
and Wind shear.
Dress. While flying: 096-20.
Ground. Effect: 09-3. loops: 028-26: 063-24 ; D65-6; 074-24;
079-27; 096-10 ; safety on. 024-3.
Hail. 031-18; 049-10.
Drills. 0 67-14.
Drugs. Use by pilots: 08-6; 048-27; D58- 16; 063-9, 19; 085-8;
090-13 - see also Alcohol.
Dust. Danger of fuel contamination: 065-7.
Electrical. Failure: 012-1; D75-8; 098-12 , 26; hazard to persons:
032-18; 0 46-14.
Emergency. Evacuation: 026-14; landings. D36-20; procedures:
D2-18; D8-14; 028-13 ; D36-20, 23; D41-12; 056-12 ; D57-14; 069-8;
088-12; 098-12.
Engine. Control: D54-23; failure: D1-23; D2-18; D6-22; D7-6, 10;
D8-14; D10-20; D11 -25. 26; 012-12, 14; D13-6, 12; D16-26; D18-30;
D19-24, 26: D25-28; D32-12; D36-4, 20; D41-12; D44-2; D45-8, 12;
D46-6, 26; D51-6, D52-10; D58-13; D59- 1, 4; D69-5; D7 1-22;
D76-22; D89-14; 091-3; 091-7, 11, 14-see also Fuel exhaustion.
Fire: 09-18; 018-4; D24-24; D33-6; D45-2; D64-16: D83-13; intake:
076-21; 0 83-21 , D89-26; mounting failure: 062-16; overspeed.
D10-14; D13-1; 015-24; D20-26; 060-10 - see also Propeller,
runaway. Power loss· D11-23; 016-20; D28- 16; D50-22; D55-13,
D64-9; D70-16; D74-14; D76-23; D80-28; D91-20; D92-14; technique: D55-13; vibration: D10-21.
Error. Causes of: 0 24-23.
Excess weight. D5-18: D8-24, 010-9; D14-26; D18-23; D19-24;
023-18; D30-8; 031 -12, 035-5; 082-6; 086-12.
False warning. 021-22
Fatigue. Metal: D2-20; 015-7; 057-10, pilot. -
see Pilot fatigue.
Feathering. D1-11; 07- 10. D8-13; 015-24; D23-10; 051 -6; D63-5;
wrong propeller: D12-14; 016-20; D19-26; D20-26; D41 -12;
D44-2.
Filter. Blockage: 046-6.
Fire. 01-7. 03-26; 028-26; 041-21 , 045-14, 18 051-2 1; D55-9;
D63-12• 065-12. 070-7, 071 -27; 079-6; D83-27; D87-26; 089-20;
16
Handstarting. 01 -9; D35-20: 040-3; 045-6; 056-14 ; 065-24;
0 76-16 ; 083-11 ; 0 88- 14; 091-14; 096-23, 26.
Head protection. 018-1.
Heavy landings. 012-17; D14-15; 018-23: 023-4; D25-24; 047-21;
060-16; 063-23; 064-26; 089-20.
Helicopters. 047- 10; 060-10; 069-8; 082-16; 086-16; 091-25.
High altitude flight. 03-3.
Hydraulic. Failure: 014-24; 032-6; fluid contamination: 017-5.
Hypoxia. 066-7.
Icing. Airframe: 014-1 ; 019-20: 023-18 , 025-3; D40-6; D57-16;
061 -25; 062-20; 085-24; 092-23; carburettor: 0 25-18; 045-20;
050-22; 059-25; 061-26; 0 85-18; engine: 028-16; helicopter rotor:
030-1 O; pilot: 0 39-24 ; throttle: D35-21.
Lightning. 039-10; 040-12; 062-22; 066-24.
Loose articles. 014-10; 023-11; 041-22; 045-25; 050-7; 0 92-28.
Lost. 03-25; 05-19; 08-26; D12-18; D16-16; 021 -10; 024- 1;
026-19; D39-18; 040-20; 044-20; 055-2, 16; D57-18; 0 66-4; D70-1;
072-1 , 18 , 21, 073-27; D78-18; 080-2; D81-23; 085-6 ; 087-16;
089-8; 098-2 - see also Navigation error.
Low approach. D21-5, D95-19.
Low flying. 03-29; D5-23 25: 06-16, 24, 25; D8-23; D9-22. 26;
D11 -22: 012-22; 013-25; D14-26; D15-28, 30; 016-25, 26; 027-27,
D28-1, D33-9; 035-22; D36-8; 047-2, 5, 7; 056-8, 20; D60-4; D63- 1;
D66-1; 074-8, 24; D77-20; 078-6; 079-6, 10; D81-6, 28; D83-2;
D84-16; 097-2.
Maintenance. 05-11 , 25; 06-8; 08-21; 015-24; 01 7-1, 5, 19, 26;
0 18-10, 19; 0 19-1 ; 020-5; 022-8, 16; 023-1 1, 23, 25; D26-24;
D27-4, 12; 028-6; 029-24; 0 31-16; 0 33-5, 16, 24: 034-10; 0 36-11,
12 ; D38-26: 042-11 ; 046-26; 047- 16. 22, 048-7 ; D49-18; D54-14,
056-17, 24, D59-27: 060-22; D62-16, 0 65-11; D67-22; 070-22;
Medical factors. 08-6; 015-1; 019-6; 028-7; 029-1; 032-18;
040-22; 043-11; 048-27; 0 51-1, 11 , D52-17; 058-16; 063-9, 19;
066-7 ; D85-8; D89-18; D90-1 3; 095-29.
Mercy flights. 0 25-27.
Meteors. 046-8.
Military accidents. D36-23; 043-14.
Misjudged. Approach: 03-11, 15; D6-10; 09-9; 010-10; 012-10;
D25-24; 045-11 ; D71-17; D75-23; 076-2; D78-14; height: 070-19;
093-20; length of strip: D82-6; D91-11; wind: 058-10.
Mixture control. Technique: 087-22.
Mountain wave effect. 03-22: D5-22; 042-6; 057-22 : D88-27,
D94-14 - see also Downdraft and Turbulence.
Mustering. 093-6, 10.
Navigation. 023-1; 031 -13; 032-16; 035-1; 055-supplement ;
D72-28; 097-16 ; error· D12-15; D18-16; 019-12; 026-6, 19; D27- 11 ;
D39-18; 041-6; 044-20; D47-26; 0 55-10; 072-10, 18 ; D89-2;
093-12; aids: 0 33-27; 034-20; 053-13; 087-26.
Near miss. D74-18; D75-28; D77-28.
Night. Flight at: D22-24; D52-2, 6; 055-2, D67-24; D72-1, 10,
078-14; 085-2; 093-2; 094-26; 095-6.
Noise. 037-20.
Noseover. 083-17.
Oil. Filter· 032-19; on windscreen: 045-5; shortage: 044-9; 0 46-26;
system: 056-24.
IFR-VFR compromise. 07-15, D8-8; 023-12; 031-24, D67-24;
095-2, 6.
Outback. Operations 1n: 05-6; 046-21; 053-20; 055-10,
supplement ; 058-17; D72-28; 077-6; D97-16, 20; 098-14.
Outlandings. Gliders: 062-2; D84-21 , 26.
Ignition switch. 053-26
Overcontrol. D31-1.
ILS. 09-6; 022-10.
Overloading. -
Inadequate. Length of strip· 050-16; 058-20, 26; 097-22 ; for landing: 058-6; D65-20; 088-14; for take-off: 058-1 , 18; 064-5: D67-16;
075-26 - see also Unsuitable landing, take-off areas.
Incident reporting. 027-10; 032-15; immunity· 024-1; 054- 1;
0100-1 .
Overpitching. Helicopters: 0 51-9.
Insects. Hazards. D43-27, nests: 016-26; 049-22: 055-21;
D89-24.
Fabric separation. 0 30-23.
Last light. Flight after: 012-18; D21-1 O: 028-20; D49-13; 055-16;
059-8; 0 69-27; D78-18; D81-2; 086-18; D89-8 - see also Night,
flight at.
Licence suspension. 037-22.
Instruments. Error in reading. 01-16; 046-18 - see also Altimeter
error. Failure of· 02-24; 028-11 , 031-6, 064-27, D91-27; 098-24;
flying technique: 0 24-13; D54-18 - see also IFR-VFR compromise, Cloud and Night.
Jet. Blast: 026-13; 050-8; 060-20 ; 065-12; 080-11; 098-16; intake
danger: 015-2.
Landing. Performance. 042-1 ; obstruction 03-28: technique: 06-3;
010-3; 014-5; 021-5; 025-8; 029-16 , 064-1 ; 079-22, D95-19;
097-10.
see Excess weight.
Overrun. Runway: D1 -24; D6-21 ; 09-9: D17-9. D20-16; 023-21;
D28-26; 030-4; 045-11; 058-6; 065-8, 20; 082-6; 090-14.
Overshoot. 012-12.
Oxygen systems. D18-6; 041-21 ; use of: 052-21; 061-22; 066-7.
Papua New Guinea. Operations in: 066-16.
Parachuting. D48-1, D56-13; 069-14 ; 070-11 .
Penetrations. Controlled airspace. D19-12, 028-3, D46-4; 069-22
- see also Controlled airspace.
Performance. 0 11-7; 020-17; 027-6; D29-11 ; 038- 1, D61-12;
0 64-10 ; 071 -10, 080-21, D85-24 - see also Landing and Take·
off, performance.
Photochromic lenses. 095-29.
Pilot fatigue. 08-2; D12-10, 22: 017-22, IJ19-6, D20-18; D26-6;
072-10; D86-27; D95-19.
Pitot. Blockage: 066-9; 075-23, covers left on: 049-14; 052-16.
Power settling. Helicopters: 068-20.
Preflight checks. 028-21; 038-24; 042-14, 19; 049-21; 060-14;
066-9; 093-16; 096-29; 098-27 - see also Cockpit checks.
Pressing on. In bad weather: D16-25; 017-13; 018-20, 28; D22-15;
031-22; 060-1; 073-2; D79-2; 082-10, 19; D91-16.
Professionalism. 079- 14.
Propeller. Damage. 01-22; 026-9; 0 31-27; D34-8; 087-8, 094-27;
danger to persons: 040-10; 056-14; 076-16 ; 089-23; 096-23;
failure of: 01-22; D3- 12; 010-14; 027-1 ; 043-16; 069-1: D72-24;
handling: 035-20; maintenance: 018-10; 072-24 ; pitch angle:
02-14; 06-1 2; 09-11 ; 017-9; 033-20; D35-26; runaway: 013-1 see also Engine overspeed and Handstarting.
Race. Air. 082-24; 084 -21.
Radar. 024-6; 040-5.
Radio. Compass: D23-1, failure: 022-7: D45-13; 046-27;
procedures: 038-28; 0 42-28 ; 047-19. 27; 052-13 ; D68-22 - see
also Communications.
Refuelling. 01 -7; D42-28; 047-19, 27, 055-9; 063-12.
Remote areas. - see Outback.
Reverse thrust. 031-7.
Rotor. Failure- D7-23; 053-2; D57-1 ; 069-8.
Runway. Condition. 05-21; 08-7 ; D9-9; 020-24: 023-21: D85-10.
D89-13, loose objecls on: 041-22; 045-25; 050-7: visibility: 03-7.
Safety harnesses. 0 26- 1; 034-11; 036-27.
Scuba diving. Flighl after 028-7; 043-11.
Search and rescue. 025-1, 28; 036-3; 077-1; 086-21 ; D91 -20;
SAR watch: 0 39-8; 050- 13.
Seats. Security of: 062-14; 096-28.
Sensory Illusions. 02-5; 03-9 ; 07-8; 016-1 ; D18-23; 020-8, 21;
0 35-6; 037-25 ; 074-8; 075- 2, 18; 096-14 - see also Visual
illusions.
Separation. Aircraft traffic: 019-3; 035-1 ; D61-10; 094-28 also Controlled airspace, etc.
Shock loading. 0 67-22.
see
Slope. Helicopters landing on: 09 1-25.
Spins. 01-22; D3-20; 05-23; 010-17, 22, 23; 016-28; 019-18;
021-26; 022-1 , 22; 026-10; 030-3 ; 031-26; 054-11; 061 -6; 069-1:
084-2; spiral dive: 015-28: D75-12.
Stalls. 02-24; 03-22, 29; 05-18, 21, 25; D6-24; 07-25; D8-23;
09-22; 011-23: D14-21 ; 016-25; 018-7; D19-20; 020-1 ; 021-12, 26,
27; 030-3; D34-14, 19; 037-10; 042-15; D43-8; 044-11 ; 045-12;
047-2, 5; 048-10; 0 56-1, 8, 26; 077-20; 078-6; D79-10; 083-6;
084-21 , 26; D88-9; 089-14; D92-2, 7, 20; D93-6, 10; 094-22;
097-6.
Statistics. Australian air safety: 087- 12.
Structural. Damage: 049-16; 054-21 ; D65-12; 076-12; 077-17;
088-24; 090-28; failure: 02-20; 05-25; 09-20; 011 - 16; 014-15;
015-28: 021-1, 6; D23-4; 024-4; 025-24, D27-3; D28-12; 031-1 ;
033-22; D34-24, 035-18; 043-20; 046-12; D51 -20, D57-10; D59-10;
D68-5, D81-1 O; 082-2; D83-13; 086-8; 090-2; D94-2; limits: 030-3;
038-1 ; D46-12; 0 76-12 ; 090-2; loose part: D46-11; 059-20;
078-11 .
Student pilots. 091-3 , 8 - see also Training.
Survival. 046-21; 050-26; 077-6.
T-Vasis. 041-5.
Take-off. Obstruction: 03-31; performance: D1-13; 02-15; D5-7,
21; 07-27; 020-16; 033-1; 0 37-4; D62-19. 20; 064-10; D83-6,
088-9; 092-20; weights: D10-9 - see also Aborted take-off.
Taxi-ing. 01 -22: D3-24· 0 53-20; D58-5
Thunderstorms. 0 11-3; 031-14; 054-26 ; D59-10; 060-6; D68-5;
082-2, 22; D94-2, 10 - see also Tornadoes.
Tiger Moth. Technique : 081-14.
Time. Computation of: 069-27.
Tornadoes. 054-26.
Training. 01 -1'1, 22; 03-20; 04-1; 06-12, 17; 08-13; 010-22, 23;
011-27; 014-2) : D19-8, 18, 024-20: 026-10; D42-13; 056-5;
059-22; 063-5; D65-8, 076-26: 093-2 - see also Student pilots.
Trim. 015-5; 032-22; 046-1 ; 048- 10: 059-27: 070-14 .
17
�Trip record. Maintaining: 02-1 2.
VSB (ELT) beacons. 091-20.
T urbulence. 013- 10; 016-18; 021-1, 25; 025-7; 030-17; 043-20;
052-22; 0 57- 10, 22; 059-1 0; 0 60-6; 0 67-12 ; 068-5; 082-2, 22;
093-24; 094-2 - see also Wake turbulence.
Wake turbulence. 02-16; 021-6; 031-20; 0 51-14; 054-25; 063-14;
0 65-16; 087-20; 094-28; 095-10.
T urning back. After engine failure on takeoff: 089-14; 092-7;
093-16.
Tyres. 0 23- 17; 049-21.
Undercarriage. Collapse: 058-14; 060-22; 064-26; 067-16;
069-16; 070-24; 089-20; damage: 069-12; difficulty: 058-13;
098-12; down during flight: 05-7; 014-24; 059-19; 092- 18; failure:
0 33-15; 049-18; 0 60-22; 066-12; 083-23; 098-28; retraction on
ground: 01-21; 05-14; 018-26; 019-8; 023-23; 032-22; 069-24;
0 76-14; 094-27; warning light: 059-15 - see also Wheels up landings.
Undershoots. 03-15; 05-17; 012-17; 021 -13; 026-16; 043-12;
061-24; 064-1; 076-2; 078-14; 080-26; 093-20, 24.
Unsuitable. Landing areas: 05-25: 07-26; 039-4; 0 42-20; 047-26;
050-2; 055-14; 058-14; 061-20; 067-19; 070-1, 11; 074-21;
078-18; 096-21; takeoff areas: 03-26, 20; 06-21, 22: 09-24;
0 12-19; 028-24; 045-10; 050-16 - see also Inadequate length
of strip and Agricultural strips.
Vapour locking. 043-6.
Visibility. 0 3-7 , 31; 06-25; 09-23; 010-10; 013-21; 017-21; 037-1 ;
045-26; 048-18; 057-16; 059-25; 061-24; 070-19; 0 76-2; 084-16;
089-20; 091-28; 095-29; 0 97-29; 098-8.
Visual illusions. 0 37-25; 078-1, 14; 093-20 - see also Sensory
illusions.
Weather. 01-20; 03-17; 05- 19; 08-8, 17; 013-21; 014-18; 016-1 4,
18; 026-16; 031-18; 038-25; 039-10; 0 40- 12; 049-10; 0 52-22;
054-26; 060-6; 062-22; 0 66-24; 073-17; 074-1; 079-2; 081-2;
087-16; 092-23 - see also Hail, Lightning, etc.
Welding. 0 33-5.
Wheel. Failure: 049-18; loose: 039-7.
Wheels up landings. 01-10; 06-26; 014-4, 25; 029-12; 039-27;
050-27; 051-21; 0 62-10; 066-12; 068-1 8;083-18; 092-18; 098-12,
28.
Wind. Gusts: 01 -24; shear: 06-9; 014-13; 030-12; 0 31 - 14; 034- 12 ;
094-1 O; 098-20 - see also Downdrafts.
Windscreen. 045-26; 074-21; 097-29.
Winter. Operations during: 025-4; 0 85-16.
Wire strikes. 03-26; 05-23; 06-16, 24; 07-23; 08-25, 26, 27;
09-21, 25; 011-22; 0 12-4, 21, 22; 013-24; 015-27, 30; 018-1 ;
020-19; 021-18: 025- 14; 028-22; 031-28; 035-22; 036-1, 8, 18;
039-4; 047-7; 0 56-1 6, 20; 058-17; 059-16; 060-4; 063-17; 0 64- 14,
22;· 066-1; 0 67-1, 3, 5, 7, 10, 19; 0 68- 10, 16; 070-7, 26; 074-24;
079-6; 080-28; 083-2; 086-2; 088-14, 16; 0 96-4; 098-8.
Wooden structures. 0 19- 1.
Notes
During the last two years VHF-activated runway and
associated aerodrome lighting has been introduced at a
nu mber oflicensed and government aerodromes
through out Australia. There are now about 30
installations listed in th e Aeronautical Information
Publication (AIP) and the Visual Flight Guide (VFG ).
As widespread as the use of the equipment is becoming,
a recent in ciden t report concerning a Night VMC flight
in New South Wales revealed that th e pilot, who held
a Night VMC rating, did now know how to operate the
lighting. While this knowledge is primarily of interest to
pilots holding Night VMC and instrument ratings, it
may also be of use to th e VFR pilot who finds himself
in an emergency situation requiring a landing after last
light or in extremely hazy and dark conditions.
The lighting is operated by a transmission on a discrete
VHF frequency from a n aircraft within 15 miles of the
aerodrome and a bove 1500 feet AGL. With the
appropriate frequency selected, three transmissions of
approximately three seconds du ration spread over a
period of not greater than 25 seconds will activate the
lighting for 60 minutes. Each transmission activates a
code element after approximately one second but cancels
that element after five seconds. Three complete code
elements within 25 seconds will activate the lights. For
this reason it is importan t to li mit each transmission to
approximately three seconds. The system may be
activated/ r e-activated by th e appropriate transmission
from an aircraft on the ground or in flight. Flashing
white warning lights, located near the terminal
building, indicate the last 10 minutes of the 60-minute
cycle a nd ,-unless r'e-activated, the aerodrome lightjng
will extinguish.
There are a number of operational requirements
associated with use of the system a nd it is not intended
to specify them in this article. It is intended, however,
18
to acquaint readers with applicable documentary
references so that they may increase their knowledge of
the facility. (References quoted below were current at the
time of preparation of this article.)
The system operation was described in Central Office
Class II Notaro 7/ 1977 which is valid until inclusion in
the AIP and V FG. T he Notaro also contains the
operational requirements concerning the use of
VH F-activated lighting.
The eleventh edition of the VFG produced in 1977
contains two applicable references. A t page 177 in the
Night VMC Procedures Section is a detailed description
of the system, its activa tion and the applicable
operational requireme~ts. At page 117 in the Flight
Planning section is a list of aerodrome ligh ting facilities
including those equipped with VHF activation. The
information contained on this page was updated recently
by Notam CO 10/1 978.
The AIP contains a similar list of aerodrome lighting
facilities and alternate aerodrome requirements in the
RAC/ O PS Operational R equirements section. D etailed
operating instructions will be included but, until they
are, AIP users should refer back to Notam CO 7/1977 .
As furt her aerodromes are equipped wi th the lighting,
Class I Notams will be issu ed on completion of
installation commissioni ng and AIP/ VFG lists will be
amended accordingly. Activation freq uencies .will also be
progressively published on landing charts and in the AIP
a nd VFG aerodrome directories.
All pilots are advised to read the above references and
take particular note of those aerodromes equipped with
VHF-activated lighting loc<ite!l iI1_their. normal area of
operations. Kr.iowledge of the correct "way to operate the
system may.benefit you if the lights a r e required in a
moment of stress e
19
�- --.
Take notice of empty fuel gauges
We all know how inaccurate fuel gauges can be; however, when they show empty do not take a
chance as the pilot of this Cessna 150 did!
The aircraft collided with the steep ly sloping bank at
about 70 knots, t he port wing tip striking the ground at
the base of a t ree stump. Slewing to the left, the aircraft
ca me to an abrupt halt only 10 metres directly up the
sloping bank, extensively damaged . T he pilot and
passenger escaped with only minor injuries.
Dur ing a de tailed examination of the aircraft at the
accident site, a total of 5. 1 litres of fuel was drained from
the tanks and li nes. This was 8. I litres less than the
normal quanti ty of unusable fuel. T he line to t he
carb urettor and the carburettor itself con tained only a
fe w drops of fuel.
Immediatel y befo r e the aircr aft took off from
Kalgoorlie the day before the accident, t he fuel tanks h ad
been filled to over-flowing. Some time after reaching top
of clim b, the p ilot said he leaned th e mixtu re by pulling
out t he mixture con trol u ntil a dr op in RPM was
indicated on the tachometer, a nd then pushed the
control half way back into the panel, p lus 'a little bit
more'. T his technique however, wou ld be of doubtful
va lue a nd, in all proba bility, the aircraft was operating
with virtually a full-rich mixtur e. O n the flight to
J a ndakot, the pilot did not attempt to lean the mixture at
all.
T ho ugh the p ilot ha d planned fo r a fuel consum ption
of 22. 7 li tres per hour, a su bsequent check of the
aircraft's records established th at its average fuel
consumption was 24.1 litres p er hour . T he total e ngine
opera ting time after refuelling at Kalgoorlie was 195
minutes, giving an overall consump tion for the two days
flying of 28.6 litres per hour, or 5. 9 lit res per h our more
than the figure the pilot had used when p la n ning the
flight.
Shortly before landing at the e nd of the first day's
flight, the passenger had in fact drawn the pilot's
attention to the fuel gauges. T he righ t gauge was
indicating empty and the left gauge nearly empty. The
pilot replied that the gauges were unreliable and that the
flight plan calculations showed they had sufficient fuel to
reach Jandakot next day. Later, the pilot explained he
did not refuel before taking off for J a n dakot because he
had left the fuel carnet card behind in K algoorlie. No
dipstick was available and the pilot did not look inside
the tanks because, he said, even if he looked in, he could
not estimate how much fuel was there. But even if the
pilot had simply added the actual flight time of 155
minutes from Kalgoorlie to his estima ted 37 minutes for
the flight to J andakot, he wou ld have seen that he did not
have the required 45 minutes reserve - even if the
aircraft had achieved a consumption rate consistent with
his planned endurance of225 minutes.
The accident site was only 26 kilometres from
J andakot and it would have taken only another 11
minutes for the ai rcraft to have reached its destination. It
is ironica l that, if as little as 10 litres of fuel had been
added before the aircraft took off, the accident would
probably not have occurred. Though fuel gauges may
not always be accura te to close tolerances, empty
indications for both tanks surely cannot be ignored !•
The last gasp!
The pilot of a Cessna 150 had planned to fly from
Kalgoorlie to Jandakot, W.A., accompanied by a
passenger. The flight was to be carried out over two
days, with a landing at a country town en route and
an overnight stay. The pilot's flight planned time
interval to the first landing point was 144 minutes
and he had calculated the aircraft's endurance as 225
minutes, using a fuel consumption rate of 22.7 litres
per hour for the 85 litres of usable fuel available.
Departing Kalgoorlie, the p ilot climbed to 3000 feet
where he levelled off a nd set 2500 RPM for the cruise.
He leaned the mixt ure by pulling out the control knob
until the RPM dropped, then pushed it in again a bout
ha lf-way. The flight was apparently uneventful and the
aircraft la nded a t its destination for the first d ay 155
minutes later, having taken 11 minutes more tha n the
flight planned time interval.
. The pilot and passenger went about their business and
next day, about 1630 hours, the pilot telephoned
J a ndakot to obtain a weather br ieCing a nd lodge a flight
plan. His estimated time interval to J a ndakot was 37
. minutes. The pilot did no t have the aircraf~ refuelled, nor
20
ciid he physically c heck th e tank contents.
After take-off, t he pilot clim bed to 2500 fee t a nd, on
levelling off, noticed the fuel gauges were sh owing j ust
a bove empty. The need le on the left gauge was moving,
indicating there was some fuel in th at tank, but t he right
ga uge did not a p pea r to move at all. The pilot knew from
past experience t hat this gauge tended to stick, so he
continued on towards J a ndakot.
About 28 m inutes after take-off, the a ircraft was
overflying a large water reservoir when the en gine
misfired twice, then lost all power. The pilot carr ied out
his e mergency drills, but the engine did not pick up. He
transmitted a M ayda y call, a nd began looking for a
place to put t he aircraft down.
The reservoir is surrounded by forest and the only
a rea tha t appeared suitable for a forced landing was the
sloping bank j ust above the water line. The pilot selec'ted
a stretch of grou nd that seemed to be the least obstructed
and, just before touch d own, turned off the fuel, and the
mas ter a nd mag neto switches. H e went to lower th e
fla ps, but they would not extend without electrical
power.
A Cessna 182 land ed at Mackay, Q u eensland, after a
flight from Archerfi eld, and requested clearance to cross
the in tersecting run way ahead. I t was cleared to do so
a nd ins tructed to tu rn off at the first taxiway. B ut a couple of m inutes later the tower con troll er saw that the
Cessn a had still no t crossed the runway a nd, as there was
a no the r aircraft on fi nal for the runway on which the
Cessna h ad lan ded , he repeated the clearance. T he controller then noticed that the Cessna's engin e had stopped .
The p ilo t advised that he was trying to restart it. T he
aircraft on final was ins tru cted to go around.
T he pilot of t he 182 then got out of his aircraft an d
began to pull it off the runway to one side. H e stopped
pu lling the aircraft sh ort of the in tersecting runway but
a ppeared to be a bout to cross the runway on foot. The
a ircraft that had been instructed to go around previously
was n ow on final fo r the intersecting runway and the controller, alarmed and unsu re of the Cessna pilot's intentions, asked the Fire Service unit to go to his assistance
immediately.
A few minutes later the Fire Service advised that the
aircraft had appar ently ru n out of fuel. After being
refuelled where it s tood, the aircraft was taxied off the
runway to the parking area.
It turned out tha t the pilot had no t landed at
Rockh a mp ton to refuel on t he way to M ackay as he
orig inally pla nned , a nd th at though his planned enduran ce showed he should have had sufficient fuel for the
flight, he had in fact made a number of errors in his calculations . Firstly, he had omitted to include a figure of
18 minutes in the total time interval. This sh ould still
have allowed him to complete the fl ight with sufficient
fuel, though without the required reserve. But as well as
this the p ilot had used a fuel consum ption rate considerabl y more optimistic than his actual usage. The high fuel
consumption rate was caused largely by the pilot's failure
to lean the mixture.
The pilot said late r: ' I now realise that mixture con trol
is an integral part of flyin~ and also that to plan a fligh t
with only the requ ired reserve is an extremely unsafe
procedure .'
Comment
We do not doubt the pilot's good intentions in his
im plied resolve to carry more than th e required reserve
for future flights but he seems to have missed the point
to some ex tent. Carrying only the req u ired reserve is no t
in itself an unsafe proced ure, but when the flight is a long
one, as in this case, poor fuel management can easil y
erode the minimum fu el reserves and result in a dangerous situation .
It should also be said that the pilot's movements about
the aerodrome after he found he could not restart the
aircraft's en'gine, wi thout advising the tower of his in tentions, were both hazardous and d isruptive to o ther traffic.
When in doubt, ask for advice! •
21
�Search and rescue, part 3
The search area
Figure 1. Calculation of Datum - Sea Search
When the distress position can be positively fixed, the search
area becomes a circle based on the datum point. To facilitate
aircraft allocation this is boxed-in or squared, as in Figure 2.
Previous articles on Search a nd Rescue in Australia d ealt
with the SAR org anisa tion, its lines of resp onsib ili ty and
its functions. This article describes the procedures and
problems associated with dete rmining the area to be
searched.
The most difficult problems confronting the SAR
Mission Co-ordina tor are where to b egin looking a nd
h ow to determine the search a rea. The answer is in the
collation of information on hand or availa ble from a
number of sources. This d a ta ca n vary widely from a
M ayday message indicating the aircraft's precise position
to informa tion provided by a friend or a rela tive, which
may be vague a nd completely la cking in d etail.
Information used to alert the SAR organisa tion is
obtained from a wide variety of sources and directed to
the a ppropria te Australian SAR a uthority . When a n
aircraft is missing, advice normally comes from Air
Traffic Control or Flight Service but, on some occasions,
such as whe n there h as been no p re-flight notification,
it m ay come from a member of the p ublic.
Recreational b oating on coastal waters presen ts the
grea tes t search and rescue problem in Australia. This is
the resp onsibility of th e appropria te Sta te or T er ritory
Police, as is the p roblem of p erson s missing on la n d .
Because of the time lapse tha t is freque ntly experienced
be tween such a mish ap a nd the commencement of a
search, the a rea to b e search ed becomes so la rge th a t the
opera tion often goes b eyond the resources of the S ta te
con cerned and the SAR responsibility is subsequ ently
h a nded over to the Commonwealth. It is a t this time th a t
the D epartment of Transpor t Marine Operations Centre
is activated a nd, if a n air sea rch is necessary, the avia tion
Rescue C o-ordina tion Centres become involved.
In the case of ships a t sea the M arine O per a tions
Centre has both the alerting a nd SA R operational
responsibili ty. Most commercial ships operating in
Australia n wate rs are required to ma ke regula r reports
through the Australia n Ship Reporting System
(AUS REP) . Ifa ship's master fails to ma ke a scheduled
report SAR action will follow.
When the p ossibility of SAR action is recognised , a
'SAR Phase' is decla red whic h indicates the d egree of
a pp rehension felt for the missing persons . The
introdu ction of this p h ase always results in the
commencem en t of some search p la nning, the d egree of
wh ich depends upon the urgency of the situa tion.
O nce it is esta blish ed th a t search action is ind eed
required , th e search is commenced a nd will con tinue
until such time as all missing persons have been located
a nd survivors resc ued , or it becomes eviden t that
con tinuation of the search with the best available SAR
units is unlikely to locate survivors.
22
H aving reached a decision to com mence the search,
it is essential that a sound p lan be prepared. This p lan
provides the basis for t he en tire op eration a nd a great
deal of expertise a n d exp erie nce goes in to d evelop ing it.
Plan ning a sea rch poses fi ve dis tinct q u estions:• the initial a nd most obvious is, 'wh at is the mos t
proba ble p osition of th e missing persons?'
• next, if their pr.obable location is not known, 'wh at is
the extent of the area in which they could p ossibly be?'
• then, 'how m a ny and wh a t typ es of ai'r craft, boa ts or
la nd p aFties are need ed to ad equately search th is a rea?'
• fourthly, 'wha t a re the best search patter ns to be used?'
• and finally, 'how ar e the available r esources to be used
most ad van tageously to adequa tely cover this ar ea?'
This a rticle d eals with the first and second of these
qu es tio ns, the selection of the·search area.
Search pla nning and the size of the area to be cover ed
varies from one environment to a nother. If an air craft
h as crash ed on land the factors to be consid ered in
d etermining the area are the crash position as notified,
or the last reported position a nd the route being fl own.
An a rea is then calcula ted which allows for possible
n avigational inaccuracies of the d istressed aircraft a nd
includes a toleran ce wh ich accoun ts for the same type
of inaccuracies affecting the searching aircraft. Reader s
will be aware tha t it is strongly recommend ed that
survivors remain a t the crash site_.
If however a n aircraft has di tched a t sea, inflated life
rafts and jackets will drift rapidly from the poin t of
impact, which is known as the Splash Point (SP) . T he
longer the per iod of elapsed time, th e g reater the effect
of drift.
C onsider the exam ple of a yachtsman who is r eported
to have p een at sea for th ree months on a two month
voyage. If he me t with a mishap at the end of the two
month period he would h ave been adrift for one month.
If, however, a mishap occurred shortly after the voyage
bega n, he could h ave been drifting for three months. The
res ultan t search area would be incredibly lar ge.
Let us now consider the ditching of a n aircraft a
consid era ble distance off the coas t. The SA R Mission
Co-ordinator ·will be given advice of the event within a
few moments of the receipt of a distress call. H e will act
immedia tely to determine the Splash Point. T his
becomes the da tum for h is cal cula tions to establis h the
sea rch a rea. The d a tum will be either the position
notified in th e d istress call or a dead reckoning (DR)
calculation based on the last reported _position.
If the aircraft fails to transmit a distress call its
disappearance will be detected when it misses its next
pla nned position report. Search an d rescue actio n will
61
62
63
I
66
64
Figure 2. Land Search Area
t
67
I
Splash
Point
PACIF(C
Bearing and di s ta~ce
from splash point
gives datum.
>i'l
I
00
Leeway
Datum for
Search area.
OCEA/\'
commence a fixed period of time after the estimated time
of arr ival at tha t position reporting point. T he
C o-ordinator will assume the aircraft to be between its
last repor ted position a nd its des tination. T he most
p robable sear ch area is the section of track between the
last rep orted position and the unreported position. T he
da tum for th e search area will then be a D R position
cal cula ted from fl igh t plan information.
T he possibility of a diversion from track, or of a
communications failure wh ich could result in the aircraft
actually being beyond the missed position, are considered
bu t do n ot affect the calculations used initially to
d etermine t he search a rea. T hese factors become relevant
when su rvivor s cannot be located after extensive
coverage of the primar y area.
IfSAR units are available in or close to the search area
soon after the ditching, th ey will be directed along the
missing aircr aft' s track because the life rafts would not
ye t have had time to drift very far. Unfortunately this
is a rare even t a nd a significant time has us ually elapsed
before aircraft a nd ships can be alerted, briefed and
a rrive in the area. By this time the rafts are no longer
close to the Splash Point.
T he problem then is to determine where they have
gone. This problem is compounded as the area is
searched with out resul t. If by the second or third day
of the search survivors have not been sighted, the d rift
of the r afts can run in to hundreds of miles a nd the search
area becomes gr eatly expanded , possibly to the point
where it is impossible to conduct a successful search.
H ow does one determine the position to which the rafts
have drifted? This is affected by three factors - sea
current, wind current and leeway. T he d irection and
movement of the life raft drift is referred to as 'set' and is
quoted as the direction towards which the movement is
taking place. For example, a set of090/ 15 means moving
in an easterly direction at 15 nau tical miles per day.
I n most cases the average sea current is obtained by
reference to the 'Atlas of Ocean Currents', however,
there a re many oceanic areas in which there is insufficient
current data as yet recorded. Should an emergency occur
in one of these areas, a sea current is obtained by plotting
a vector average of surrounding known currents. Because
this result will not be precise, an additional vector is
included. T his procedure is known as plotting for
minimum and maximum drifts or a 'minimax' plot.
Wind current is the movement of the water genera ted
by wind acting on its surface. This is usually limited to
a depth of about 0 .6 metres and is directly related to the
period of time the wind has been blowing. I t will
therefore change with varying weather patterns. This
current results from wind strength, duration a nd the a rea
over which the wind is blowing. It eventually reaches a
limiting or.maximum velocity. The direction of the wi nd
current set is t he down wind vector of the surface wind,
modified by the effects of'coriolis force'. T his is the force
generated by the earth's rotation and causes deflection
23
�The human element
Acknowledgement to the Aviation Safety Letter, Canada, for the following short articles involving
various aspects of human factors.
Figure 3. Sea Search Area
A typical maritime search area where the Splash
Point is not known. ·
-
Understanding the 'press-on' mentality
Unreported
position
Last
reported
position
A '
Planned Track
Search
Area
Boundary
MELl:\OURN ·
OJ 8011t.0
11A K
MAC.
Calculated
Drift
Datum 1
::> PART.Jiff TRACKS
IN 'l NO
ME
WEIR
NGS ONE
,C'OT A
060
11
0 1
'
.
of the ocean surface movemen t. In the Southern
Hemisphere this deAection is always to the left.
Leeway is the movement of a n object wh ich is being
pushed through the water by local wi nds blowi ng against
th e exposed surfaces of the object whi ch are kn own as
freeboard. The grea ter the frecboard, the greater the
wind effect a nd consequen tly the greater the drift. T he
wi nd effect is countered by the water drag on the
under-water hull and , in the case of life rafts, a sea
anchor, if fitted. The water drag varies with the volume,
sh ape, depth and orientation of the section of the vessel
under water.
The direction of the leeway vector for life rafts a nd flat
bottom boa ts is downwind. Other types of surface c raft
can d iverge to either side of the wind vector and the
degree of divergence is abou t 40 degrees fo r boats,
trawlers and ships, and 60 deg rees for sailing boats.
T he magnitude of the leeway is fou nd by examination
of statistics derived from observat ion of actual leeway
rates of various types of craft. These are ta bulated in
miles per d ay for life rafts and as a percentage of the
average wind speed for other craft. For exa mple, the
leewa y speed fo r a large cabin cruiser is calcul a ted as five
24
AUSTRALIAN FIRs :
per cent of the wind speed. Any change in surface wind
conditio ns will affect the leeway and requires the
calculation of separate vectors.
Plotting the calcul ated vector value of these three
factors will result in a d atum point given as bearing and
dista nce from th e SP as shown in Figure 1.
The search areas described above are not necessarily
t he final areas to be searched. The SAR M ission
Co-ordinator modifies the extent of the search area with
incoming information. This is partic ularly relevant to
searches in which members of th e public are req uested,
by radio or T V b roadcasts, to report either heari ng or
sighting the missing aircraft or vessel, survivors or
wreckage. Each report is carefully eva luated and if
assessed as being accurate may assist in determining the
route actually taken. This procedure can considerably
redu ce the a rea to be searched, thus facilita ting more
thorough searching by the SA R resources available at
the tim e.
The nex t a rticle in the series will d eal wi th the selection
of search aircraft a nd the allocation of these to a specific
search a rea e
M os t mature people have had occasion to ask themselves
' What made me do a thing like that?' Those who emerge
unscathed from a close call a re probably quite determined never to let it happen again . But it's often a deeply
personal matter which some p eople feel they should keep
to themsel ves, so their press-on experiences aren ' t of
much use to others. Besides, it's difficult to explain the
motivation behind their behaviour. For example, the
p olice often get the driver 's answer, 'I guess I like to drive
fast'. The fact that he is furious at his boss probably
wouldn ' t occur to him .
It takes a lot of deep digging to understand how a
pilot's pe rsonality influences his decision-ma king - a nd
it takes experts to do this work. Human factors investigations are the most productive but unfortunately are the
mos t elaborate and expensive. Here's a brief outline of
the background work we did in a recent crash which
killed a pilot.
The pilot took off in his aircraft one night, encountered
low visibility a nd snowshowers, and lost control. There
was n o particular urgency for the flight; in fact, it was
to be a training hop - his first night cross-country.
To really understand what happened we need to take
a closer look at the ma n himsel( He was middle-aged ,
had flown sporadically for ten years, accumulating about
150 hours. He then purchased a new aircraft and had
flown 65 hours in the previous 90 days. He was obviously
now an ardent flyer, firmly intent on upgrading his
skill.
His instructors knew him a s a man who had a 'know-itall' ma nner - you couldn' t tell him anything. Add to
this the fact that his wife was in hospital, apparently with
a n e moti onal disorder . Having been denied a night endorsement pending further training, the pilo t deliberately a ttempted his fligh t without his endorsement and
into weather which was obviously unfavou rable.
The picture emerges of a man who would let littl e or
n othing s tand in his way - not even weather. Taking
tha t attitude into the cockpit is as king for trouble. In this
accident, no innocent passengers paid with their lives for
the pilot's action - but it does happen ...
A tragedy in one act
play but a live tragedy. The pilot had just completed an
intensive six months flying course to ob tain his commercial licence.
Why would a young fellow with apparently everything
going for him, ac t in such a way that he and his friend
end up as accident statistics? This is a human factors
problem for which we have no ready answer. Several witnesses said that the aircraft pulled up sharply, stalled and
crashed . It could be that the pilot finding himself l ower
than he intended, pulled up sharply in an effort to avoid
power lines - we shall never know for certain. But, we
do know the end result was traged y!
Eat - and stay alert
Are you one of the estimated three ou t of four people
who skipped breakfast this m orning? If you did, you
could be a candidate for a n accident, according to Dr
J .E. Monagle of the Department of National H ealth and
Welfare, Canada.
He poi nts out that your blood sugar after an overnight
fast is a t a low level when you wake up. In many people
this cause.s morning irritability, irrational emotional
responses, grogginess, a nd confusion. Add to these the effect of sudden stress or e motional reaction, such as rising
anger a t a rush-hour lane-hopper. This stimula tes a sudd en release of adrenalin, further lowering blood sugar
a nd in creasing your chances of an accident. Dr Monagle
cautions that when you're in this state, it's unwise to do
things requiring alertness, concentration, mental and
physical responses.
Studies at a university add to these facts. Students who
didn' t have breakfast showed markedly poorer classroom
performance. And in London, Engla nd, police have
noted that traffic accidents happening around 10 o r 11
am frequently involve persons who have not eaten, or at
leas t not properly. For exam ple, a sugar/carbohydrateheavy breakfast can spur a n over-release of insulin which
drops blood sugar below the no-brea kfas t level.
While we have no statistics on accidents to nonbrea kfasted pilots, the points made here appl y also to
pilots . To be mentally and physically alert, the breakfast
should contain some protein - a n egg, glass of milk, or
even a sausage or some bacon - before that pre-flight•
The actors: a young com mercial pilot with prospects of
an interesting and rewarding Aying career, and a friend.
The scene: a popula ted area a nd a low-flying aircraft.
The finale: a crash followed by a fire, a s mouldering
wreck, and two people dead. Unfortuna tely it was no
25
�Pre-take-off 'lethal' actions
(Pilot contribution)
With over l500 hours offl ying time an d a class one
instrument rating, l view mysel f as a careful and
relati vely experienced private pilot. But my confiden ce
was recentl y shattered by t h e following incident w hich
occurred on the 1600-foot airstrip on my fa rm ing
property w hi ch is locatcci on <1n island in Bass Strait.
\II y ai rcraft is a rcct>nt mod el C herokee 6-300. Very
mu ch awa re of th e shor tcomjngs of op erati ng su ch a n
ai rcraft from a s hort, bush strip, I am in th e habit of
making frequent reference to the performance chart prior
to d eparting from th e far m. H owever , on the day of this
incident, the conditions were particularly favourab le, as
the take-off directi on was down the slight slope into a
lig ht wind, a nd with four children, three adults a nd
half-full tanks l considered, from experien ce, that it was
unnecessary to consul t th e chart. (I n fac t, later reference
to the take-off chart indicated that take-off would have
bee n possible under the prevailing conditions at
maximum all up weig ht.) Accordi ngly, alter a careful
pre-Right inspection and unhu rried pre-take-off checks,
T p repa red for the usual precau tionary styl e take-off
chat I employ at this strip. Standing hard on the toe
brakes, I opened the throttle fully, checked gauges,
released th e brakes and the aircraft accelerated down the
strip. The accelera tion was less than I expected but since
the speed was building up and a borting th e ta ke-off was
then becoming margina l on the d ownsloping d amp grass
surface, I concentrated on maki ng the best of the take-off.
Take-off safety speed was reached very close to th e end
of the strip an d we were awa y without further trou ble.
l remember thinking to m yself tha t this was a
surprisingl y marg inal take-off in view of th e conditions
a nd told m yself tha t I must check the performance charts
26
again at th e destina tion. This proved un necessary,
however, because the ex planation for t he marginal
nature of the take-off became apparent as I joined the
circuit a t m y destination. Commencing m y downwi nd
checks, l found Lo my horror that th e parking brake had
not been disengaged. T h ere followed a couple of days of
rather agonising self~ ana l ysis. H ow coul d T ha,·e so easily
endangered seven lives?
A few points emerged wh ich a rc worth notin15 for thos e
who operate a ircraft, like the Cherokee, which has a
parking brake independen t of the toe brakes . F irstly, the
C herokee 6-300 has sufficient power to accelera te with
th e parking brake on. Secondly, examination of the
ha ndl ing notes of all the aircraft l h ave flow n showed
tha t non e sp ecifically listed release of t he parking brake
as part 0fthc pre-take-off vital actions, even though mos t
reminded th e pilot to apply the parking brake before th e
run-up. But the ma in r eason for my oversight probabl y
arose G·om the diflcrcnt n atu re of operation from t his
s trip, bearing in mind that most of my opera tions arc
from major aerodromes. When operating from a major
aerodrom e, t he only times that th e p ark ing brake is
employed arc in the tarma c area and in a holding ba y
or a t the holding point: l n the case of this incident,
however, th e run-up was conducted lined up on th e strip
itself, a situation in which I would not normally be usi ng
th e parking brake. Furthermore. my whole a t tention was
cievo tcd to making a perfect precautionary take-off with
a ppropriate use of toe brakes.
From now on, my pre- ta ke-off checks will he ending
with ' ... Controls - full a nd free movement; C learance;
PARKI GBRAKE- RELEASED!'e
'I told Junior to make sure
the field was cleat
~~
'
........
l t was 0630 hours when a commercial pilot was tak-ing
off from a property in North Western Australia on a
musteri ng flight. The Cessna 150 was about halfway
al ong th e strip when th e pilot noticed a kangaroo
approaching from the port side on a Ii ne of constant
b_eari~g. T he ~i lot recognised the pending collision
s1tua twn and 111 a snap-second computer-age decision,
elected to contin ue the take-off. T he kangaroo's stone-age
d ecision making processes reached exactly the same
conclusion and just after the Cessna left the ground, the
kan~aroo con:ui:i enced a magnificent jump over the
movmg alum1111um fence which was blocking his way.
T he fur a nd bone Hying marsupial col lided with the fin
of the Cessna. The Cessna pilot was able to maintain
c?n tr_ol of his b~ckled aircraft and made a teardrop
circu 1t pattern followed by a safe land ing.
.14
.,,.
I
•
;
I
I
,
"'
6-v
In the absence of any kangaroo wreckage it must be
concl_uded ~hat he _also made a successful forced landing.
Desp1 ~c valiant efforts by the Regional In vestiga tor, the
offend mg kangaroo could not be located to provide his
side of the story. lt must be also concluded that he has
'gone bush'.
Although this account of an actual recent accident has
been treated light-heartedly, the problem of a nimals on
aerodro~es makes it essential that pilots take every
p:ecaut1on to ensure the area will be clear duri ng the
a ircraft's take-off run. I t is appreciated that JOO per cent
success can never be guaranteed. Perhaps amongst our
readers, however, there are some who encounter this
problem regularly and h ave developed safe and sound
techniques t'o overcome it. We would be pleased to hear
from them with a view to printing their solution for the
benefit of other readers e
27
�In brief
In brief
e At the termination ofa navigation exercise, the pilot of
a PA28 made an approach to runway 04 into a surface
wind of050 degrees at five to ten knots. As he was about
to round out he was distracted by a soft drink can which
had rolled off the back seat, under his seat and fi nished
up beneath the rudder pedals. The pilot considered going
around but d ecid ed against it as he was almost on the
ground and was afraid that the can would foul the pedals.
Holding slight rudder on to correct for drift, he hooked
the can out wit h his left foot and was bending down to
retrieve it when he inadverten tl y pushed the con trol
column forward. The aircraft's nose wheel struck the
runway hard, the propeller was bent and the aircraft
bounced back into the air. The pilot applied power to
recover fro m the situation but the aircraft bounced
several more times with d ecreasing severity before finally
settling on the ground. The pilot switched off the electrics
and fuel a nd steered the aircraft off the runway. As well
as the bent propeller, the aircraft suffered substantial
damage to the nose gear assembly.
e A student pilot in a Cessna 150 was conducting practice
solo forced-landings in a designated training area
situa ted within controlled airspac~. H e was commencing
each sequence a t about 2500 feet and terminating at
400-500 feet above ground level.
On the fifth sequence, approaching the break-off
height with full flap set, the pilot was requested to report
altitude and position. He replied giving the required
information, replaced the microphone in the holder,
applied full power and commenced raising the flap by
stages. At this time he received a lower instruction to
remain below 2500 feet. He acknowledged the cal l but
did not read back the altitude restriction and just after
he replaced the microphone in the holder th7 to.wer as~ ed
him to confirm 'below 2500 feet'. H e looked ms1de agam
to pick up the microphone, and later concluded that
while doing so he p robably relaxed some of the forward
pressure he was applying to the control wheel. H e says
he felt a gust of wi nd strike the aircraft and on looking
outside he found that the aircraft was apparently in a
spin to the left. H e applied full opposite rudder a nd some
forward pressure to the control wheel, but did not have
time to reduce power before the a ircraft entered the tops
of dense mangrove growth in a 30 to40 degree nose-down
attitude at very slow speed.
The mangroves cushioned the impact a nd the aircraft
travelled only five metres before the nosegear contacted
the ground and collapsed. The pilot turned off the fuel
and vacated the aircraft bu t returned shortly afterwards
and transmitted a Mayday call. This was received and
15 mi nutes later the crashed ai rcraft was located by an
F27 which had diverted to the area.
Comment: Pilots in the early stages of t heir training
learn to develop and establish an awareness of priorities
for maintaining safe flight but, occasionally, some pilots
place undue priority on radio communications and the.
acknowledging of transmissions - particularly from air
traffic control. They tend to 'drop everything' in
their haste to reply fully to a call. The need for
communication is important, but the need for a pilot to
maintain control of his workload and to ensure safety of
fligh t is more important.
The transcript of air-ground communications
indicated a fairly high· concentra tion of radio
transmissions to the aircraft in a very short period, b ut
the tower controller was nol to know that t he pilot was
in a high workload situation. In these circumstances a
brief 'ST AND BY' in reply to the instruction to remain
below 2500 feet would have sufficed. Alternatively, it
would have been quite acceptable ifthe pilot had delayed
replying to the tower until he had secured the aircraft
in the climb configuration and had then explained the
situation. In discussion, the pilot readily agreed that had
he delayed answering the tower, u ntil settled in the
climb, there would have been no problem.
• During a landing roll on an outlying property strip the
nose wheel of a Cessna 182K sank through the surface
crust into the soft su bsoil and the aircraft nosed over. The
property is si tuated mainly in Queensland but extends
into the black soil plains of the Northern Territory. A
feature of this black soil is that when drying out after
rain has fallen it forms a cracked surface crust but retains
a porridge-like condition underneath.
The pilot's main duties as a flying stockman were to
check the security offences and to maintain an adequate
water level in the bore troughs. Landing at individual
bores became necessary only when the water level was
low and pumping was required . H e had been fl ying the
station-based aircr aft fo r six months and was well aware
of the characteristics of the black soil patches which were
present in many of the bore strips.
On the day of the accident the pilot was scheduled for
a routine bore run. Substantial rain had fallen on the
property some 10 d ays previously, rendering most of the
strips temporarily unserviceable. There had been no
further rain in the area for several days so, following an
aerial inspection, a normal landing and take-off was
made at the first bore. On arrival over the second bore
the pilot inspected the strip from 500 feet and again from
300 feet and could not see any wet patches which would
preclude a landing. The aircraft approached at 60 knots
with full flap selected and touched down smoothly in the
centre of the strip. As the aircraft was decelerating the
pilot raised the flap and was proceeding at about 20 knots
when the nose wheel sank through the crusty surface.
The aircraft stood on its nose and fell slowly over on to
its back. T he pilot emerged uninjured.
In the course of the investigation it was discovered that
the aircraft had passed through two patches of black soil
before it sank into a larger third patch. I t was considered
that the precautions taken by the pilot to ascertain the
serviceability of the strip were reasonable. Nevertheless,
this accident again highlights the problem of assessing
strip serviceability from an aerial inspection.
29
28
�Turbo-charger failure
Many general aviation aircraft are fitted with
turbo-charged engines wh ich prov ide relatively high
power in an efficient manner. Because of the high
temperatures and pressures produced in the turbine
exhaust systems, any malfunction of the turbo-charger
must be treated with extreme caution.
A computer read-out of occurrences concerning
turbo-charger malfunctions revealed 112 incid ents in the
last eight years. Of these 10 were a ttributed to bearing
failure, 44 to defective controlle rs and the remainder to
various causes including oil seal failures. There were 31
engine shutdowns, five overheats and one in-flight fi re.
Manufacturers' ha nd ling notes of many turbo-charger
equipped aircraft do not adequately describe the actions
to be taken in the even t ofa turbo-charger failu re. Pilots
are advised to adopt the following procedures if a
ma lfunction is experienced:
Overboost con dition
If an excessive rise in ma nifold pressure occurs duri ng
normal adva ncement of the throttle (possibl y owing to
faulty operation of the waste gate):
• immedia tely retard the throt tle smoothl y to limit the
manifold pressure below th e m axi m um for th e RPM
a nd mixture se tting;
• operate the engine in such a manner as
further overboost condition.
to
avoid a
Low manifold pressure
Although this condition may be caused by a minor
fault, it is quite possible that a serious exhaust leak has
occurred crea ting a potentia ll y hazardous situa tion.
Such a leak might not be visible to the pilot:
• shut down the engi ne in accordance with the
recommended engine failur e procedures, unless a
grea ter emergency ex is ts that warra n ts co ntin ued
engine operation;
• if continuing to opera te the engine use the lowes t
power setting demanded by the silllation and land as
soon as practicable to inspect the system.
I t is very importan t to ensure tha t corrective
mai n ten ance is unde rtaken following a turbo-charger
malfunction. After landi ng, advise a LAME immediately
a nd enter the defect in the aircraft's maintenance
release, making particula r note of the amount of
overboos t a nd its duration. T he corrective action taken
by the engi neer is based on t h.ese fig ures, in accordance
with Rolls Royce and Lyco ming b ulletins . These
bulletins, T-107 and 36Q.E respectively, also provide more
detailed operational gu idance e
Be prepared
for carburettor icing
Eng ine power losses continue to occur as a result of carburettor icing. Ice build-up in the carbu ett0
air intake can gra~ually choke off the air, enriching the mixture and reducing engine power. Alth~ug ~
more prevalent during tt1e winter months, carburettor ice can form at any time of the year if the cond itions
are SU1table. Learn to recognise the s11uat1on and be prepared for carburettor 1c1ng 1
Serious icing-any power
Moderate icing-cruise power
or serious icing-descent power
Serious icing-descent power
Light icing-cruise
or descent power
+20°
+ 10°
oo
0
-
0
·-c
fc
Q)
-10°
Avoiding a loss of communications
Every year since 1973, gen eral av1at10n aircraft h ave
been involved in more than 2000 incidents involving
communication breakdowns between aircraft in flight
and ground stations.
To some, this figure migh t not seem so ba d ,
considering t he volume of general aviation operations
now taking p lace every d ay of the year. O th ers would
say, so what? It is simp ly the price we pay for using fair ly
complex equip ment in a soph isticated operating
environment .
But though there may be justification for both these
views, the majority of general aviation p ilots would no
do ubt agree t hat b ecause much inconvenience, an xiety,
a nd often exp ense, results from these incidents, it is in
ever ybody 's interests to keep th em to a n absolute
m inim um .
One thing m ust be made clear from the start - it is
not being suggested that these incidents ar e all caused by
pilots. In fact u p to 60 per cent a re t he resu lt of factors
such as atmospheric interference, equipment fai lure, and
terrain interference. A considerable amount of research
is going on into fi nd ing ways of overcoming these
proble ms. But still this leaves us with 40 per cent involving the p ilot. T h e following a r e some of th e reasons, as
shown by the Department 's incident records, for Joss of
communication when pilots have been responsible:
Incorrect use of equipment:
• radio not switched on
30
• generator not switched on
• wrong frequency selected
• volume turned down or incorrect use of squelch
control
• VH F operated outside range of ground station .
Inadequate flight preparation:
• appr opriate route frequencies not fitted
• p lan ning a full-reporting flight beyond usable VHF
range without HF equipment
• fa ulty calculation of SAR T IME - insufficent time
available to get to a telephone to cancel SARWATCH .
Inadequate reporting procedure:
• failure to report departure
• failure to report en route an d a rrival
• failu re to cancel SARWATCH
• fail ure to report at nominated position reporting
point.
Air traffic clearances not followed:
• failure to follow instructions
• failure to communicate on correct freq uency.
With such loss-of-communication incidents occurring
at a rate of six per day, it will be readily appreciated t hat
a constant st rain is being placed on the resources of the
Departmen t's airways operations system. Obviously a
little common sense, togeth er with a study of the
app licable communication requirements before every
flight coul d greatly reduce the num ber of in cidents in
this category e
-20° -10° 0° + 10° + 20° + 30° + 40°
Air Temp °C
- refer to the chart when flight planning to anticipate carburettor icing
- ensure carburettor heat .works during engine run-up checks (initial drop in rpm when heat applied)
- continually monitor engine instruments; loss of rpm (fixed pitch propeller) or decreasing manifold
pressure (constant speed propeller) could mean carburettor ice is forming
- apply full carbure~tor h~at early if icing is suspected, and keep it on (the engine may run rough for
a short period until the ice melts)
- if th~ situa!ion allows, lean the mixture carefully, after selecting carburettor heat, to smooth out the
engine until the ice melts
- continu.e to use carbu rettor heat whi le the probability of ice formation exists adjust mixture control
accordingly
•
- sev.eral minutes before descent use full carburettor heat at cruise power. Periodically open the throttle
dudnng extended lo~ power descent to ensure enough heat is maintained to melt carburettor icing
an to keep the engine warm
- if you are .unsure about ~ny of the above points discuss them with a suitably qualified person before
commencing your next flight.
31
�
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Aviation Safety Digest
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Aviation Safety Digest, number 103 (1978)
Identifier
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103
Date
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1978
-
https://collections.heritageoftheair.org.au/files/original/98e9d85eabd9b66c2c103c551b0f67dd
cf582203103fc7708b6d63638a78fb4e
PDF Text
Text
•
•
*
102/1978
Department of Transport -Australia
•
1 es
I
�~'
.J O H N
.-...M l\\JL.ANt.l.
102/1978
ST JOH N AM
Contents
' .. . the last person I would expect to enter cloud' /2
FRONT COVER
In 1961 the Whyalla Ambulance Committee was formed in
affiliation with the St. John Council for South Australia to operate
two road ambulances serving the Whyalla area. The service
expanded rapidly and eventually eleven branch services were
operating around the Eyre peninsula. In 1970 the Service was
reconstituted and became the St. John Ambulance Service Upper Eyre Peninsula Incorporated. The comb!ned resources :>f
the twelve offices currently support the operation of three aenal
and 16 road ambulances.
.
The operation of the Air Ambulance began in 1965 when
concern was expressed over the effects the long journeys in road
ambulances were having on seriously ill patients. In October of
that year a four seat Piper Cherokee aircra ft was pu~chased and
converted to an aerial ambulance. During the following 12 years
of operation, the service purchased a fleet of twin engi~ed
aircraft. In 1976 this comprised three Piper Senecas and a Piper
Navajo. One Seneca and the Navajo were disposed of to allow the
purchase of a Navajo Chieftain, a longer v~rsion of th~ Na.vajo
with more internal space. The service considers the Chieftain to
be the optimum unit for aerial ambulance transport with a
capacity for three stretchers, two sitting patients and an attendant
- a vast improvement on the original Cherokee!
.
Since 1965 the St. John Air Ambulance for South Australia has
carried more than 7000 patients and flown 3. 7 million kilometres.
The year 1976 saw a dramatic increase In operations with 1154
patients being transported, 46 per cent more than in.1975.
From its humble beginning in 1965 when the Alf Ambulance
only served the Eyre peninsula, the fleet now operates over the
length and breadth of South Australia. Doctors i~ the country
areas are becoming more aware of the benefits of the Alf
Ambulance service. The ability it provides to transport a patient
from an outback centre to a major city hospital in less than two
hours is an obvious advantage over the journey by road lasting up
to eight hours.
.
The accompanying photograph s show the modern equipment
used by the service as fitted to the Navajo Chieftain.
l
A PA28-180 Cherokee crashes in the North Mount Lofty Ranges
in 'below VMC' conditions.
Do's and don'ts of alrmanshlp/4
Aviation Safety Digest Is prepared in the Air Safety Investigation
Branch and published for the Departm ent of Transp or t through
the Australian Government Publishing Service, in pu rs uance of
Regulation 283 of the Air Navigation Regulations. It Is distributed
by the Department of Transport free of charge to A ustra lian
licence holders (except student pilots), registered aircraft owners,
and certain other persons and organisations having a vested
operational Interest in Australian civil aviation.
DME distance - from where?/5
Incident In which the crew of a 8727 Inbound to Perth
commenced descent with the DME tuned to Plngelly, 67 nautical
miles short of the aircraft's destination.
Aviation Safety Digest Is also available on subscription from the
Australian Government Publishing Service. Enquiries should be
addressed to the Assistant Director (Sales and Distribution),
Australia n Governme nt Publishing Service, P. 0 . Box 84,
Canberra ACT 2600. Subscriptions may also be lodged with
AGPS Bookshops In all capital cities.
Beware of power llnes - In more ways than onel/8
Programmed mlnd/9
Some thoughts on aircraft accidents and their
preventlon/1 O
Compass confuslon/1 3
A simple lnvestlgatlon?/ 14
A recent incident Involving less than standard aircraft separation
in a primary control zone provides a good example of the way that
an investigation can develop.
Are you security consclous?/1 6
Look, no englnes/18
Accidents caused by Inadvertent Interference with selectors or
controls are by no means uncommon.
Change of address:
Readers on the free distribution list should notify the Department
of Transport, P.O. Box 18390, Melbourne, Victoria 3001.
Subscribers should contact the Australian Government
Publishing Service.
c; Commonwealth of Australia 1978. The contents of this
publication may not be reproduced In whole or in part, without the
written authority of the Department of Transport. Where material
is indicated to be extracted from or based on another publication,
the authority of the originator should be sought. The views
expressed by persons or bodies In articles reproduced in the
Aviation Safety Digest from other sources are not necessarily
those of the Department.
Pilot contributions and correspondence on articles should be
addressed to the Aviation Safety Digest, Department of
Transport, P.O. Box 18390, Melbourne, Victoria 3001.
RM76 / 30216(2) Cat. No. 78 9099 7
Printed by Ruskin Press, 39 Leveson Street, North Melbourne,
Victoria.
Wheels down - no llghtl/1 8
Aerobatics and structural llmltatlons/19
Note: Metric units are used except for airspeed and wind speed
which are given In knots; and for elevation, height and altitude
where measurements are gi ven In feet.
Switches and buttons - for what?/23
Your role In search and rescue: part 11/ 24
Frost, Ice and snow/27
Blrdstrlkes/ 28
BACK COVER
An alternative means of conveying patients by air is the
helicopter. When landing space Is limited and time is critical the
helicopter is the most expedient means of transport. Shown here
is Victoria 's ANGEL OF MERCY helicopter, a Bell 206, arriving at
the Alfred Hospital in Melbourne.
- with acknowledgement to the Herald and Weekly Times.
1
�'... the
last person I would
expect to enter cloud'
"The whole area was covered with fog or mist. The tops of
the hills to the east were co mpletely covered with fog and it
was misty underneath that, right back to the homestead.
H owever the windmill up the track could be seen clearly.
The visibility deteriorated as I climbed up the hill. I then
looked down and identified a 'shape' below me. It was the
crashed aircraft".
In these words a station overseer in the M ount Lofty
R anges north of Adelaide described the findi ng of a
wrecked PA28-180 Cherokee in which a young man, his
wife and both his parents were killed. It was the tragic
finale to a meticulously planned flight by a very
conscientious but inexperienced pilot.
Th e pilot was 33 years old, a se rious person
passionately fond of flying. As soor: as the area
restriction was lifted on his private licence, he began
p lanning h is firs t long distance flight - a return trip
fro m Strathalbyn, 50 kilometres south-east of Adelaide,
to Ayers Rock with intermediate landings at Leigh
Creek a nd Oodnadatta. The first leg of the flight to
Leigh Creek was planned outside controlled airspace a t
3500 feet to Mount Pleasant, t h ence via Eudunda,
Burra, Peterborough and H awker a t 5000 feet.
The pilot realized that with such limited flying
experience he was embarking on q uite an ambitious
undertakin g but with th orough planning and
preparation he was confident that the trip would be a
success . He even took his parents for a local flight to
ensure that they were happy to travel with him in a light
aircraft, and five days before the trip flew to Parafield to
discuss the proposed flight with the briefing officer. He
pre-computed the flight time intervals up to Ayers Rock
and sought the a dvice of pilot friends on navigational
procedures. These peop le later recalled that the pilot
was p articularly conscious of the folly of attempting to
fly in cloud without an instrument rating. He had
indicated that if he ever encountered cloud he would
always t urn back.
At about 0530 hours on the morning of the flight the
pilot telephoned Parafield and obtained the relevant area
meteorological forecasts. The forecast for the route
segment over the ranges indicated a south-east airflow
with scattered stratus cloud, base 1200 feet, scattered
cumulus cloud base 2500 feet, broken strata-cumulus
base 3500 feet a nd visibility of 35 kilometres reducing to
10 kilometres in showers and drizzle. The route planned
by the pilot to remain OCTA took the aircraft along and
a lmost directly above the top of the North Mount Lofty
Ranges which contain numerous peaks risihg to as much
as 3000 feet. C loud base heights indicated in area
forecasts are expressed in feet above mea n sea level
(AMSL) and it should have been obvious to t he pilot
that there was a strong possibility these ranges would be
in cloud.
In his first radio communication with Adelaide FSU,
the pilot reported that he had departed Strathalbyn at
0712 hours and was climbing to 3500 feet. At 0728 hours
he reported position at Mount Pleasa:it and that he was
descending to 3000 feet to 'remain VMC'. Three minutes
later he reported descending to 2500 feet. The pilot next
reported his position at 07 45 hours over Eudunda but
this time he made no reference to altitude. The last
t ransmission received from the aircraft was at 0746 hours
when the pilot acknowledged an instruction to change
frequency at Burra Creek. It is significant that in-flight
log entries later revealed that he had misidentified Burra
as Peterborough.
At about 0800 hours residents of Burra (elevation
approximately 1540 feet) saw a light aircraft approach
from the south a n d make a 360 degree turn to the left.
The a ircraft was at an estimated height of about 300 feet
and was below overcast low cloud. It flew away on a
northerly heading towards the hilly terrain surrounding
Mou nt Cone (elevation 2601 feet) some 10 kilometres to
t he north. Several minutes later a person in the Mount
Cone area, where th e hills were enshrouded in fog, heard
the high-pitched sound of an aircraft engine. He caught
a fleeting glimpse of an aircraft emerging from cloud at
high speed before it disappeared behind a hill to the west
of the mountain. This was followed by a sound of
impact.
T he aircraft had struck the northern slope of a hill at
an elevation of 2225 feet. At the time of the crash it was
in ·a steep nose-down attitude at high speed, and on a
northerly heading. The Cherokee had virtua lly
disintegrated and all four occupants had been killed on
impact. The wreckage was examined in detail but
nothing was found to indicate that the aircraft was
incapable of normal operation immediately prior to the
accident.
*
*
*
Map showing probable flight path and site of accident.
3
.2
�T he traged y of this accident is that the pilot could
hard ly have had a more correct approach, ·either to
aviation safety or to his preparation for this particular
fl ight. Nevertheless, a lthough the forecast d id not
pr eclude operations in VMC, he would have been wise to
have planned to avoid the higher ridges a nd this could
have been achieved by heading west from Strathalbyn
and then north along the coast through the Adela ide
Control Zone.
In the cold light of the investigation, it is evident that
the pilot's second error was that of persevering on his
chosen track in the face of deteriorating visua l
cond itions. On the stretch between Mount Pleasant and
Eudunda it should have been apparent to him tha t VMC
could not be maintained if the flight were continued
nort h towards the higher ra nges. T his was when a
d iversion should have been made. H owever there can be
little doubt that by this stage the situation had become
too much for the pilot to handle at his level of experience.
Perhaps more than anything the pilot fell into the
psychological tr ap of believing that all his exhaustive
pre-flight pla nni ng would elimi nate the need for lastminute in-flight revision a nd free him to concentrate on
navigation duri ng the fl ight. In h is anxiety to
methodically prepare fo r every aspect of the trip he
might have over looked the necessity fo r continuing
vigilance and flexibility. It is surely a n error to which we
are all prone.
DME distancefrom where?
Fig. 1: Map showing air route Green 94 and designated reporting
points between Melbourne and Perth.
•
B
SydneyQ
• _ QAdelaide
View from position of witnesses showing (A) hill behind which aircraft crashed and (BJ Mount Cone.
Melbourne
%0-••0
Mt Gambier
Do's and don'ts of airmanship
(Adaptedfrom COPA B ulleli11, Canada)
• Do shut d own your engine before loading or
unloading passengers.
• Do warn people to keep away from the propeller
and not to touch it for any reason.
• Do taxi at a speed from which you can come to a
stop a t a ny ti me.
• Do have someone on each wing tip for guidance
when taxi-ing in confined spaces.
• Do taxi at night only on lighted taxi ways.
• Do leave the controls locked after parking the
a ircraft.
• Do set the brakes or chock the aircraft on the
apron.
• Do tie down the aircraft when parking overnigh t.
• Do use the radio only for what it was intended and keep the channels open for importan t or
emergency messages.
4
• Don't start your engine before being assured your
propeller is clear.
• Don't start your engine with the aircraft's tail
towards other aircraft.
• Don't start the engine while people are standin g
in front or behind your aircraft.
• Don't u se high power while taxi-ing in close p roximity to parked aircraft.
• Don't conduct a long pre-flight run-up in the
vicinity of offices or occupied buildings.
• Don' t ask for weather information right after takeoff if you can check it by telephone before
departure.
• Don't file a flight plan by radio righ t after take-off
if you can do it by telephone before departure.
• Don't taxi on to an apron at a fast rate. Your brakes
could fail.
In preparation for a scheduled flight from Melbourne to
Perth, the crew of a Boeing 727 submitted a flight plan
indicating that the aircra ft would operate on air route
Green 94, overfl yi ng Mount Gambier, the Great
Austral ia n Bight, Esperance and Pingelly. On this route,
aircraft do not overfly any radio navigation aids between
Mount Gambier a nd Esperance, a distance of 958
nautical miles, though they are within range of off-track
aids at various times. While crossing the Bight on this
route, position reports are required at the designated
reporti ng points Pipefish, Shrimp and Sea Mink (See fig .
1)
Departing Melbourne at 0957 hours GMT, the
aircraft i:limbed to flight level 330 as planned. A position
report was given at Mount Gambier two minutes ahead
of the fl ight plan estimate, at Pipefish five minutes ahead
of plan and at Shrimp seven minutes ahead. The next
position report was at Sea Mink at 1204 hours, eight
mi nutes a head of plan, and an ETA for Lake Grace was
given as 1244 hours, 12 minutes ahead. At about midway
betwee n Sea Mink and Lake Grace, which is 150
nautical miles from Per th and 86 nautical miles from
Pingelly, the ai rcraft overflew Esperance. Though not a
reporting point fo r the flight, Esperance is equipped with
VO R, NDB and D M E. So far throughout the flight the
Varrowee
J
first officer had logged the time of passing over all
navigation aids and reporting points. At the time the
aircraft passed over Esperance however, the three
members of the flight crew were engaged in conversation
not relating to the operation of the aircraft, a nd the first
officer made no navigation log entry. The next
navigation aids on track were the NDB and DME at
Pingelly, 67 miles south-east of Perth. After passing over
Esperance therefore, the captain's DME was selected to
channel five, Pingelly, and some time later the first
officer's D ME was also selected to this channel.
At 1240 hours the crew reported that the aircraft was
at Lake Grace and Perth Arrivals Control issued the
instruction 'when ready, descend to six thousand, not
below DME steps'. The crew had planned to commence
descent 130 miles from Perth and, at 1242 hours, when
the DME read 130, the captain commenced descent and
the first officer reported 'left flight level 330'.
As the descent progressed however, the crew found
that they were unable to read the ATIS broadcast on the
Perth VO R. T hey advised Arrivals Control of this and
were given the current terminal information. At 1256
hours they endeavoured to establish two-way
communications with Perth Tower and, though the
aircraft's· ·transmissions were read by the tower
5
�controller, t h e crew could no t hear the tower.
Satisfactory communication was re-established with
Arrivals Control and at 1258 hours the crew reported 20
miles from Perth. The crew m ade further attempts to
establish communication with Perth Tower but two-way
communication was satisfactory only with Arrivals
Control.
At 1259 h ours the aircraft was instructed to continue
its descent to 5000 feet and the crew went on with their
attempts to establish communication with the tower by
listening to tower transmissions on the NDB frequency.
T his was only partly successful and communication was
therefore resumed with Arrivals Control. At 1302 hours
the crew reported 'coming up to six DME at 5000' and
were instructed to enter the Parkerville holding pattern
(based on a locator beacon n ine miles north-east of Perth
Airport), and to descend to 2500 feet.
At the time of t he incident, the primary means of air
traffic control in Perth controlled airsp ace was by the
application of procedural control techniques. An A TCmanned radar unit was availa ble but at that time was
being used only on request to assist in resolving specific
traffic separation situations, and not as the primary
means of control. At 1302 hours, the Perth approach
controller, a p preciating that the aircraft was appa rently
experiencing radio navigation and communication
difficulties, alerted Perth Radar and requested that the
aircraft be radar-monitored. At about the same time
Arrivals Control cleared the aircraft to commence a
locator-omni approach but the crew replied that they
were not yet ready to do so and would maintain 5000
feet. When Perth Radar advised that no radar return
from the aircraft could be observed, the aircraft was
instructed to maintain 3000 and, on request, the crew
advised their position as 'eight DME - coming up to
Parkerville '.
At 1304 hours the crew reported a failure in the
aircraft's ILS equipment and shor tly afterwards, in
response to a query by Arrivals Control, advised that the
VOR receiver was also not operating. At 1306 hours the
crew were requested to establish communications with
Perth Radar. After they had done so satisfactorily, the
aircraft was identified by radar 50 miles from Perth
approaching from the south-east. At about t his same
time, the crew realised that the a ircraft's DME was
selected to Pingelly and not to Perth. The lowest safe
altitude in the area where the aircraft was identified is
2800 feet and the base of controlled airspace is 6000 feet.
The crew then accepted a clearance to climb to 6000 feet,
during which the radio navigation aids in the aircraft
returned to normal operation . With radar monitoring,
the a ircraft then made a normal approach to Perth;
where it landed at 1325 hours.
The rad io antennae for Perth Tower, as well as for t he
Perth VOR and ILS, a re located at Perth Airport. T he
communications antennae for Perth Arrivals Control
however, a re sited in an elevated position remote from
the airport. For air craft operating at lower levels to the
east of Perth Airport, the presence of intervening high
terrain somewhat restricts the range of Perth Tower and
some radio aids, but for normal operations this does not
impose limitations. In this case it is obvious that the
aircraft involved in the incident had communication and
radio navigation aid difficulties only because of its
distance and direction from Perth, and its lower-thannormal altitude.
The grid point meteorological forecast covering the
period of the flight predicted winds which would result
in relatively light westerly components for the early
stages of the flight, increasing to a westerly component of
about 40 knots by Sea Mink and remaining at about this
strength for the remainder of the flight. Post incident
analysis indicates that a light easterly component would
have been experienced during the early stages of the
fligh t, gradually changing to a westerly, similar to t hat
forecast, fro m Sea Mink onwards. The differences
between the forecast and actual winds would account for
t he aircraft gaining time as far as Sea Mink and
operating according to plan beyond that point.
The aircraft was fitted with a flight data recorder and
the tape covering t he last 45 minutes of the flight was
read out and analysed. This indicated t hat t he descent
from flight level 330 was commenced 42 minutes before
touchdown and that the descent continued to an altitude
of 5000 feet, which was reached 24 minutes before
touchdown. T wo minutes later a further descent to 3000
feet was commenced and this altitude was maintained
for four and a half minutes. Sixteen and a half minutes
before touchdown the aircraft commenced a climb to
6000 fee t and two minutes after reaching that altitude it
began a normal descent into Perth. Reconstruction of
the flight path of the aircraft indicated that at 1240
hours, when the crew reported at L ake Grace, the
aircraft was 150 miles east of Pingelly and at 1259 hours,
when some 30 miles east of Pingelly, it had altered
heading to the right and commenced to track towards
the Parkerville Locator. (See fig . 2)
While it was not possible to determine precisely the
procedures used by the crew in relation to navigation
and the use of radio navigation aids, it is obvious that
those procedures were inadequate and led directly to the
incident. It is also apparent that an ATC requirement to
radar-monitor aircraft approaching Perth would have
resulted in the incident being detected at a much earlier
stage of its development.
Fig. 2: Reconstruction of flight path from position at which aircraft
commenced descent from flight level 330.
GOT ILS & 6000'
(' 45 DME PERTH')
'IDENTIFIED 50 PERTH')
,..._ _ _ _ '3000'
'COM ING UP TO PARKERVI
PERTH
...,k---- - --
-
'8 DME'
~~-----'6
LLE 3000'
DME'
I
MILES NOW'
'UNABLE TO READ ATIS'
' LAKE GRACE AT 40'
126'!} •.
,,,,,.~~'+>=~~~=~~-~~~~~~~9!!11-.,...
. .~~
\
\
, ,,
\
,,
\
""
\
\
\
\
\
\
6
7
�Beware of power lines •
1n more ways than one!
ra n to the aircraft but fou nd h e could not reach the pilot
because the door was held shut by the power cable
caught u nder the handle. Without thinking, he grasped
the cable with both hands and wrenched it away,
lacerating h is hands as the cable sprang back and
upwards.
The loader driver's reaction was of course quite
natural, but could have proved fatal. Experience over the
years indicates that in most accidents in which aircraft
collide with electric transmission cables, the
transmission system protective relays operate as
designed. But there are circumstances where the
transmission cables can remain alive, in which case
contact with them, or with the aircraft if the cable is still
attached, could be fatal. Electricity authoPities have
advised the Department that all dislodged transmission
cables should be treated as alive until cleared as safe by
the local electricity authority.
Aerial view of agricultural strip looking in a northerly direction.
The accident site and direction of approach are shown.
Before commencing spreading operations on a farming
property, two agricultural pilots discussed the work to be
done a nd decided that one would treat the area east of
the strip while the other worked to the west. They also
discussed the possibility that if they both returned to the
strip a t the same time, one aircraft could land on a clear
a rea close to the prepared strip.
The prepa red strip was aligned almost north-south,
with trees bordering the eastern side of its northern half.
Further south on the same side, the tree line receded
from the strip, leaving a clear area to the south-east of
the southern threshold. Because the superphosphate
dump was nea r the so uthern end of the strip, it seemed
convenient for one aircraft to land into the south on the
prepared strip, while the other landed northwards on the
na tural surface of the clear area, angling in from the
south-east towards t he dump. The two aircraft could
then taxi up to the dump from opposite directions.
Operating from the prepared strip on the previous
day, the pilot of one of the aircraft, an Airtruk, had made
a n a ngled approach to the prepared strip across the clear
area but had not actually landed on it. H e had also
walked out on to the cleared area for a short distance,
and noted that the surface was satisfactory for landing
a nd that there was a contour bank running a long the left
side of the a vailable landing area. What he did not
notice, because he was not at that time thinking of
landing a nywh ere b ut on the prepared strip, was tha t
8
there were double power lines runni ng across the clear
a rea at a n angle of about 30 degrees, just at the point
where a n aircraft landing on the clea r area would be low
on final approach. The supporting poles, 260 metres
apart, were hidden a mongst trees on either side of the
clear area.
At the completion of the first spreading flig ht, t he
Airtruk returned to the strip while the other a ircraft was
still at t he super dump. So as to leave the prepared strip
clear for the other a ircraft, the A irtruk pilot decided to
land on the clear area and nose-in to the super d ump
from that side. He made a slow approach down between
the trees, looking mainly at the ground beca use he was
conscious of the need to avoid the contour bank. He did
not see th e power cables at any time. T he next thi ng he
knew was that the aircraft was decelerating rapidly a nd
that one of the two tail-plane booms had broken off. The
a ircraft just seemed to stop in mid-air, slew around, and
fall to the ground.
One of the two power cables had passed over the
engine and under the port wing, cutting into the fuselage
below the windscreen and breaking when it struck the
windscreen p illar. This caused the aircraft to swing to
the left . The other cable caught under the right hand
door h a ndle but did not break, th us bringing the aircraft
down almost vertically.
The pilot was seriously injured in the impact a nd
though conscious, was unable to move. T he loader d river
Programmed mind
H ave you ever wondered why people disregard their own
safety to get to a destination? It's primarily because we
'program' our minds, prior to take-off, to accomplish the
task we set out to do. In some p eople th is programming
unfortunately overrid es a ny admission th at the flight may
not reach its destination.
U nless you acknowledge the possibility th at something
could stand in your way, you aren't likely to program
you r al ternatives - such as turning back in the face of
poor weath er. Similarly, a pilot who discounts the
likeli hood of fuel contamination is less likely to do a
thorough pre-flight ch eck.
Recently, a sched ul ed commercial flight failed to reach
its destination a lthough the captain thought it had ! He
had reached the vicinity of the destination airport when
he requested a visual appro ach because he had the field
in sight. But what he d id not know was that the field
was not his destination - a fact that became quickly apparent to a ir traffic control. As the pilot was not on the
tower frequency, AT C asked the airport to blink the runway lights and give the aircraft a red light. D espite these
obvious signals the captain landed the aircraft at the
wrong airport.
The captain's mind was programmed to the point
where· it rejected interfering inputs, even though there
were clear indications that somethin g was wrong.
Quite a n umber of accidents contain this
' programmed-mind' problem.
- A vialion Safety Lei/er, Canada .
9
�Some thoughts on aircraft
accidents and their prevention
by Olof Fritsch
(Chief, Accident Investigation and Prevention Section,
/CAO Air Navigation Bureau)
It was still dark when I awoke. My head was resting
against the head of the bed; that was probably the
reason for my headache. Meadow larks were singing
nearby, so it would probably be a fine day. Strange
sounds intruded - a crackling like that of cooling metal
and a repeated sizzling like water drops on a hot stove.
Then it hit me. It was not a fine day - it was a very
bad day. The headboard was the rough surface of a
runway and I was hanging upside down in a Harvard
that ha d flipped over on to its back during landing. The
crackling so unds came from the still-hot engine; the
hissing noise from fuel dripping on a hot exhaust pipe. I
remembered picking up a passenger in a cow pasture by
a radar station, the bouncy rake-off on the rough surface,
th e approach at home base and my concentration on a
smooth three-point landing in the old Harvard, so
different from the jets I usually fle w. It had been a
straight, smooth touchdown, immediately followed b y a
quick swing to the right. No problem - ease on left
rudder. Intensified swing - still no problem, a little left
brake will stop it. Then the helpless feeling that the
world was governed by some new, terrible laws because
terrifying things were happening too fast to comprehend
- the nose of the aircraft striking the runway, the
propeller bending, a very loud noise. After that nothing .
This simple accident, like all accidents, had several
causes. The first was the take-off in the rough cow
pasture. It bent the tailwheel a nd caused the swing on
la nding. The second cause was a rudder-brake control
interference which resulted in right brake being applied
when the left rudder pedal was pushed forward. Thus,
left rudder didn't correct the swing - just intensified it.
T he final application of left brake then made the noseover inevitable, as both brakes were on.
Knowing the causes, how could this accident h ave
been prevented? By bigger and better tail wheels? By not
using the Harvard for personnel transportation? By
punishing the p ilot ? These are but a few choices. The
preventive action taken in this case worked well - to m y
knowledge, there were no m ore accidents of this t ype.
More about that la ter.
Fences or ambulances?
I tip my h a t to the unknown a uthor of the
accompanying poem. It i.llustrates what accident
prevention is - and what it is not. Do we b uild fences to
prevent accidents, or do we buy more ambulances?
Management and human-error
Before dealing with these aspects let me define the
term ' management ' which is here used in its ge neral
sense. Stated simply, manage ment is getting things done
through peop le. Ta ken one step further , good
management gets people to do things the right way.
Good management may a pply equally to an aircraft
manufacturing pla nt, to an airline or to a government
department which administers aviation.
The term management is often used in industrial
safety. When it comes to accident prevention, the
professionals in that field appear to have some very good
ideas. No wonder, they started long before aviation
began! The first ind ustrial plant safety.inspections were
held in the United Kingdom in 1833, and safety
legislation was introduced in Germany in 1869.
Today, a consensus is emerging. that ' accidents are
caused by human error' and, to drive the point home
a nd to establish a foundation for accident prevention, it
continues: ' . . . a nd can be traced to imper fect
management related to p lanning, organizing and
controlling. '
To managers, that m ay sound like a n unfair oversimplification. However, it is found ed o n the belief th at
we can learn from our past experiences a nd that there
are precious few, if any, new types of accidents. Further,
the identification of risks and hazards must surely be a
management responsibility.
I tried t his concept on some of my colleagues. Soon er
or later, we started talking about accident causes. One
discussion went like this: ' How a bout material fatigue
failures? They result from design, manufacturing or
m aintena nce errors. Not enough material, sharp corners,
tool marks not detected in quality cont rol, etc. Surely we
should know a bout all that by now - the bending of cast
iron bars was first investigated in 1849' .
Another concer ned aircraft striking the ground on
approach a nd landing : 'This one is more com p lex; the
specifics of each accident are different. Inevitably they
relate to th e man, the machine a nd th e e nvironment,
sometimes all three together, a nd their relationship to
eac h other. Some typ ical.. management questions th at
could be asked are :
• Was the pilot properly trained, supervised and
c hecked on that aircraft?
• Was he properly..advised about that thunderstorm on
approach ?
• Why did the approach chart not show that hill ?
• Why was the altimeter set wrong?
• Since some mistakes are more fa tal th a n others a nd
(continued
on
THE AMBULANCE IN THE VALLEY
' T was a dangerous cliff, as they freely confessed,
Though to walk near its crest was so pleasant;
B ut over its terrible edge there had slipped
A duke, and full many a peasant.
The people said something would have lo be done,
But their projects did not al all tally.
Some said 'Put a fence 'round the edge of the cliff,'
Some, 'An ambulance down in the valley. '
T he lament of the crowd was profound and was loud,
As their tears ove1flowed with their pity;
B ut the cry for the ambulance carried the day
As ii :ipread through the neighbouring city.
;:I collection was made, lo accumulate aid,
11nd the dwellers in highway and alley
Gm1e dollars or cents - not to furnish a fence But an ambulance down in the valley.
' Fnr the cliff i:, all right if you 're careful, ' they said;
' And, iffolk:i ever slip and are dropping,
It isn't the slipping that hurts them so much
As the shock down below - when they're stopping.'
So for years (we have heard), as these mishaps occurred
Quick forth would the rescuers sally,
To fnck up the victims who fell from the cliff,
fl'ith the ambulance down in the valley.
Said one, to his pleas, 'It's a marvel to me
That you'd give so much greater attention
To repairing results than to curing the cause;
rou had much better aim al prevention .
For the mischief, of course, should be stopped
at its source;
Come, neighbours and friends, let us rally.
It is Jar better sense to rely on a fence
Than an ambulance down in the valley.'
'He is wrung in his head,' the majority said,·
'lie would end all our earnest endeavour.
He':, a man who would shirk this responsible work,
But we will support it forever.
11rcn 't we picking up all, just as fast as they fall,
And givzng them care liberally?
A superfluous fence is of no consequence,
If the ambulance works in the valley. '
The story looks queer as we 'ue written it here,
But things oft occur that are stranger.
.Hore humane, we assert. than to succour the hurt
ls the plan of removmg the danger.
The best possible course is to safeguard the source
By attending to things rationally.
l'es, build up the fence and let us dispense
I Vith the ambulance down in the valley.
Cartoon : John Du bo rd, Ottawa, Canada
page 12)
11
�since humans will make mistakes, what can be done to
have the machine or the system prevent these fatal
errors?'
And so it went. The only accident we could conceive for
which we saw no error and hence no management
involvement was one in which an aircraft on landing roll
went into a large hole in the runway which suddenly
appeared because of an earthquake.
In industrial safety, the management concept is
gaining acce ptance because it seems to prevent accidents
better than any other. In recent years, aviation also has
been moving in this direction, but without the benefit of
a clearly defined concept.
The time may now be right for the formulation of such
c concept on the basis that accidents are caused by
human error which can be traced to imperfect
management. The first part of such a concept must be
that, since management is a human activity, it is prone
to error. What is needed therefore, is a system that
reduces such errors to a minimum.
Avlatlon management
Aviation management usually comprises several
organizations: the State administration, the manufacturing industry and the operators. They all have a part
to play in accident prevention. They also have one thing
in common - the man with the ultimate responsibility
for safety and accident prevention is the man at the top,
since he is in charge of the planning, organizing and
controlling of the organization. Only he can authorize
the programmes required to get people in his
organization ' to do things the right way' so that
managerial and other errors are reduced. Only he can
authorize the funds required for the elimination of these
errors.
Let us a lso face up to the fact that accident prevention
costs money - in the short term. However, in the long
term, it should save money since it reduces the financial
losses and increases organization efficiency.
It is not only the fact that a fatal accident may incur a
direct cost of half a million dollars for each fatality that
should motivate good aviation management, but the
reduction in errors relating to design, manufacture,
maintenance and operation of aircraft should make the
uti lization of aircraft more efficient. That is the heart of
the ma n agement concept: improvement of both safety
a nd efficiency.
12
Investigation considerations
When an accident does occur, the investigation must
establish and document all th e circumstances and causes
of the accident. Given that the causes of an accident
relate to human e rror and imperfect management, the
investigating group should be so organized that external
influences, real or imagined, cannot affect th e
investigation.
To maintain investigation objectivity, a number of
principles should apply to the investigating organiza tions including :
• It should report directly to the head of the government
department to which it is attached, or be a statutory
body in its own right.
• It should have access to sufficient funds to properly
investigate accidents as they occur. The nature of th e
task is such that annual fixed budgets are not
appropriate for this purpose.
• It should have a statutory right to investigate all
accidents in its j urisdiction.
• Its expressed purpose should be the determination of
acc ident circumstances and causes and t he
formulation of safety recommendations to prevent
recurrences.
The effect of these principles on an investigating
organization is like hanging a large sign over the
entrance that declares 'here, we tell it like it is.'
Punishment counter-productive
In the past, punishment of the pilot was seen as
accident prevention. Fortunately, the realization that
' the pilot is the firs t person to arrive a t the scene of an
accident' convinced management that pilots did not fly
around with the intent of having accidents. Further,
management began to realize that it h ad a responsibility
in the selection, training, supervision and equipping of
pilots, all factors which may cause a so-called 'pilot
error. '
In fact, punishment is counter-productive to accident
prevention. For example, when a pilot is punished for a
near-miss that he reported himself, other pilots in that
organization are no t likely to voluntarily report near
misses or incidents. Thus, a most reliable source of
information on hazardous conditions is lost.
Similarly, if blame and punishment is meted out to the
engineer who designed a square hole in a high stress
area; to the administrator who failed to write proper
regulations; to the manager who did not budget for the
required modification of the aircraft; to the mechanic
who installed the ailerons in reverse; or to the
investigator who missed the fatigue crack in th e
wreckage, then these people will not readily accept
responsibility or volunteer information.
Accordingly, accident prevention must be directed,
not at individuals, but at the management system, its
policies and procedures. Accidents are symptoms of
something wrong in the management system.
Top managers, whether in administration ,
ma nufacturing or operations, cannot by themselves
prevent all human errors or find all hazardous
conditions. For that they need help and that help usually
takes the form of a safety officer or organization. In some
States, such safety organizations are required by
legislation.
On behalf of the top manager, th e safety organization
usually does the following:
• Identifies and defines safety problems which have not
been detected and corrected by management;
• Assesses severity of safety problems;
• Informs the responsible functions of management
(engineering, operation, finance, legal, etc.) of safety
problems, their urgency and, if applicable, related
deadlines fo r preventive action;
• Measures the effectiveness of preventive action taken.
Note that while the safety organization identifies and
defines the safety problem it may also suggest preventive
action. However, that should only be done in general
terms, with the understanding that the required
expertise for detailed technical solutions must rest with
management. To do otherwise would require a very
large safety organization because of the expertise
required in making specific, detailed recommendations.
Further, it wo uld also tend to remove from management
its responsibility for accident prevention.
T he safety organization is directly responsible to the
top manager because he is ultimately responsible for the
safety of his organization. Routine reports to him usually
include problems detected and preventive action taken.
Also, when agreement about safety problems and
prevention cannot be reached between the safety
orga nization and management, the final decision is
referred to him.
In summary, significant improvements in aviation
safety have been achieved in the last 20 years. If we wish
to actively pursue fu rther improvements, serious
consideration should b e given to the management
approach to accident prevention. Experience in other
fields of safety indicates that this may be a simple, easily
understood and effective approach.
Oh yes, I almost forgot. My own misadventure did not
result in punishment. Instead, the preventive action was
to prohibit take-offs and landings on unprepared grass
surfaces (cow pastures) - and the elimination of the
control interference. Operations from prepared grassfields continued.
Comment
The Department of Transport is interested in
furthe ring the cause of aircraft accident prevention by
every available mea ns. The foregoing article p romotes
several thoughts on accident prevention for various
elements of the industry, t he principles behind which a re
supported by the Department.
Compass confusion
On a clear cloudless night the pilot of a Ce,ssna 182
navigationally 'mislaid himself' In the course of a
55 kilometre Night VMC fllght to a capital city
airport.
T he aircraft was equipped with nor mal IF R
instrumentation - coupled auto-pilot, VOR, ADF,
DME and a transponder. T he pilot 's total fl ying
experience was 160 hours, abou t 20 of which were a t
nigh t including 15 hours instruction. H e was already
ra ted on the AD F a nd had been receiving instruction on
the VO R , so he decided he would practise VOR
procedures on the shor t flight. A student p ilot with only
limited experience was in the co-p ilot's seat.
Before take-off the pilot synchronised the directional
gyro a n d compass. Once airborne he settled on to the
desired heading of 24 7 degrees M, set the D G bug to that
heading but was then d istracted by flickering cockpit
lights. H e t he refore asked the student pilot, who was
holding a torch, to read the compass heading out to him.
T he heading read off by the student pilot did not agree
with that on the DG, so the p ilot reset the D G. H e the n
engaged the auto-pilot and the aircraft went into a turn
to take up the b ug heading. T he pilot then returned h is
attention to the cockpit lighting p roblem. H aving fixed
this to his satisfaction, he selected the destinat ion
frequency on the VOR, identified the station and
checked the indications. A few minutes later at ET A over
a reporting point 37 kilometres from the destination
airpor t, the pilot saw town lights below so he reported as
over that position.
The approach radar controller was u nable to locate
the aircraft on radar, so he queried the position report
and asked th e pilot if he had the city lights in sight. The
p ilot replied negative and indicated that h e was now
unsu re of his position.
As the aircraft was still not pa inting on radar in the
area it was supposed to be, the controller req uested the
pilot to climb to 6000 feet. After several exchanges of
communicatio n s concerning hea d ing and DME
d istance, the pilot was requested to 'squawk ident ' ,
whereupon the aircraft was identified about 80
kilometres from its destination, heading approximately
020 degrees. T he pilot was instructed to ig nore t he
compass and D G headings and to turn right. The
controller monitored the turn a nd, when the aircr aft was
heading back towards its destination, he advised the
pilot to hold that heading. R adar mon itoring and
vectoring was provided until the pilot reported he had
the airfield in sight.
Subsequent checks fou n d no fa ults in the compass,
DG or VOR equip ment. It appears the stu dent p ilot
misread the compass to the extent that the head ing he
gave to t he pilot was about 180 degrees in error. T he
pilot, distracted by other things, accepted this h eading
without question a nd thus set himself u p fo r total
confusion when he attempted to p ract ise t he use of aids
on which he was not fully p roficient.
Night VMC flight is b ased on visual naviga tion,
supplemented by whatever aids t he p ilot has available
and is capab le of using. In this case the p ilot obviously
got h is p rior ities reversed.
13
�The incident occ urred during a night departure by a
DC-9 from a capital city airport. At the time there was a
fairly busy sequence of both departing a nd arriving
airline aircraft and as well several light aircraft were
transitting the control zone in Night VMC.
The departure clearance given to the crew of the DC-9
before taxi-ing was a standard instrument departure
(SID) ·which required the aircraft to climb on runway
heading to 3000 feet then make a right turn through 1 70
degrees. However, after take-off, the aircraft was seen on
radar to continue on run way heading beyond the point
at which DC-9s normally turn when d eparting on this
SID. The departures controller therefore immediately
instructed the aircraft to turn right. During the turn the
DC-9 came within three kilometres of a light aircraft
14
which was overflying the area.
From the initial incident report it appeared that the
ma in factor in the development of the incident was an
inadequacy in the presentation of th e SID, but after the
aircraft 's flight data recorder had been read out, a
transcript of the air-ground communications studied,
and interviews conducted with t he air traffic co ntrollers
and the flight crew, it was determ ined there had been an
overall breakdown in th e entire departure system.
The full circumstances of the incident a re beyond the
scope of this article, b ut the huma n involvement
highlights the significan t effect that a minor distraction,
coupled with less than normal a ttention to detail, can
h a ve on flying safety in a high workload situation.
*
*
*
''
T he flight which the DC-9 was to carry out was
entirely routine. For the crew it was a short d uty spell of
only two sectors and d uring flight planning there had
been no a pparent weather problems, or other foreseeable
difficulties. As well there were no loading delays or
unserviceabilities with the aircraft, and the pre-flight
checks were routine. The aircraft was heavily loaded and
for this reason t he crew had planned to take-off with five
degrees of flap.
While taxi-ing, the captain saw two other DC-9s (let
us call t hem aircraft A and aircraft B) waiting at the
runway intersectio n for departure and assumed that the
second one was that of another company operating a
parallel service to his flight (it was in fact the first,
aircraft A). He therefore elected to cancel his planned
intersection departure clearance and to use the full
length of the runway - the extra taxi-ing permitting a
more leisurely completion of the pre-take-off checks, and
it seemed that this would take no more time than waiting
for an intersection departure. This change worked out
well and the captain arrived at the holding point for the
runway threshold ' .. . in a completely happy state ... ',
anticipating that he would be number three (aircraft C),
to depart behind t he two D C-9s at the intersection.
An instruction to line up before the second of the other
two D C-9s (aircraft B) came as a pleasant surprise to the
captain as he thought t his would put him ahead of the
other airline 's service. The heavily-loaded aircraft and
an adverse runway slope involved some minor power
handling di fficulties, but he made haste to get on to the
r unway. As the captain turned on to the runway
alignment, t he AT C clearance was amended to include a
4000 foot heigh t restriction. This involved an additional
cockpit workload, causing the crew to become engrossed
in the task of re-setting the altitude alerting system. As a
result there appears to have been no positive planning for
the effects of the hei"ght restriction on the operation of the
aircraft - in particular t he handling of the power in
regard to the need to level off at 4000 foot.
H aving lined up, reconfigured the altitude alerting
system, checked . the cockpit instrumentation, and
applied take-off power, the captain confirmed with the
first officer the requirements for the standard inst rument
departure and that there was a 4000 foot height
restriction.
T he take-off was uneventful and during the initial
climb it seem s that the captain re l axed his
concentration. This is suggested by the fact that, after
the undercarriage had been retracted and the flap-slat
retraction had been made at the appropriate time, he
overlooked . the reduction to climb power until it was
mentioned by th e fi rst officer. This reminder, coming
when the captain had apparently 'got behind his
aircraft ' , certainly prompted him to reduce power, but
by this time things were happening quite fast and a
further extraneous factor t hen intervened. At this point
Depart ures Control transmitted, 'Aircraft C, turn right
heading 180 for a pilot intercept of outbound . ..
correction, aircraft A, t urn right 180 for a pilot intercept
.. . etc'. The captain initiated a right turn but then,
realisi ng th at the instruction was not for him, q u ickly
resumed the runway heading. Nevertheless this untimely
distraction provided a n additional obstacle to his
' catching up 'with the situation.
Because of the initial high power ·settings being used
and the quick clean-up of the five degree flap and slat
setting, the aircraft had been climbing at 2800 feet per
minute and was rapidly approaching the 3000 foot
height at which the SID required a right turn. The
captain was belatedly reducing power when the
erroneous A TC instruction caused him to commence
and then cancel a turn. But while all this was going on,
the aircraft went through 3000 feet without the turn
being initiated as stipulated b y the SID and it seems that
the captain's mental processes had probably shed this
requirement as a result of being overloaded by the
rapidly developing circumstances.
Within three seconds of the other D C-9 (aircraft A)
acknowledging its turn-right instruction, A TC queried
whether the DC9 involved in this incident (aircraft C )
was also turning right. The crew associated this question
with the previous exchange and answered 'Negative' .
A TC then instructed the aircraft to turn right
immediately. The captain responded without delay and
noted that by this time the aircraft had reached an
altitude of about 4000 feet .
T h roughout all this, the captain was apparently most
conscious of the 4000 foot height limitation, but t hen
exceeded this a ltitude primarily because he had not
considered the very substantial power reduction
necessary to maintain level flight at a speed of 210 knots ·
(another operational consideration) while carrying out
the 180 degree turn as required by the SID. As a result,
the aircraft's speed built up to about 320 knots and it
reached an altitude of about 4900 feet before the captain
could take positive action to reduce power and return to
the assigned altitude.
D uring the 45 seconds in which the aircraft
inadvertently climbed from 4000 to 4900 fe~t, A TC
addressed two furthe r messages to t he aircraft
concerning the terms of their departure clearance. No
doubt this distraction, occurring before the crew had
fully caught up with their earlier problems, was also
significant. It should be appreciated however, that th is
was an instinctive reaction by a controller who had also
been exposed to a situation of heavy workload with
considerable stress.
Altogether this was a human factors-type incident for
which there is no simple fix. Nevertheless, crew
simulator training exercises have been revised as a result,
to place additional emphasis on departures involving late
changes to airways clearances. The implications of the
incident have been publicised within the company
concerned as well as being brought to the attention of all
appropriate operators, and A TC is again critically
examining terminal area procedures with particular
reference to last minute changes to clearances and the
imposition of altitude rest rictions on SIDs.
The purpose of incident investigations is to try to find
out, not only what happened, but why it happened. We
may not always find all the facts, but in this case we
believe we uncovered the areas of significance. An
understanding of how a carefully devised system,
operated by h ighly skilled and experienced professionals,
can break down is surely of value to all levels of the
industry.
15
�Are you security conscious?
•
;.. .'
11
weapon. And as with motor cars, inexperience and
alcohol play a prominent part in accidents involving
stolen aircraft. Even though some would-be pilots have
actually managed to survive after becoming airborne, the
aircraft itself is almost inevitably written off. And in the
cases where the joy riders have failed in their attempts to
take off, the aircraft has usually been quite severely
damaged in one way or another. As most readers will
have already guessed, a common feature in most
instances of aircraft stealing is the fact that the owner or
operator has unwittingly aided and abetted the theft by
neglecting even the most elementary security
precautions.
After one recent fatal accident involving a stolen light
aeroplane, the Department conducted a survey of
aircraft left parked at a busy general aviation aerodrome.
Most of the aircraft examined were tied down to stop
them being blown away, but almost no precautions had
been taken to prevent them being flown away! Ignition
keys were left in switches or in some easily accessible
place, and cabin doors were unlocked. In fact the
investigators conducting the survey could have started
up , taxied out and taken off, in any one of numbers of
aircraft, unmolested by the owners or their representatives.
There have of course been numerous unsuccessful
attempts to steal aircraft. In one instance the magneto
wiring was interfered with by someone obviously
unskilled - apparently in an attempt to start the engine
using a technique similar to that used to start a car
without the ignition key. Though the attempt was
unsuccessful, the would-be thief left the aircraft in the
dangerous condition where turning the propeller by
hand would have provided a spark from the magnetos even though the ignition switch was off. It so happened
that the owner's thorough pre-flight inspection
discovered the damage before the aircraft was started.
Owners and operators are at all times responsible for
the security of their aircraft - in just the same way that
they are responsible for their house, car or any other
possession, and the locking of ignition systems and doors
are surely the most elementary measures. Of course
some of our more elderly aircraft on the Australian
register do not have lockable ignition switches, but
owners would do well to explore the possibility of
installing some form of lock to prevent the aircraft being
started without authorisation. Also wherever possible, it
is advisable to avoid parking in locations that are remote
from surveillance. And on country properties, owners
should ensure that fuel stocks kept in drums are also
adequately secured.
Aircraft are no less liable to interference and theft than
any other means of transport. Effective security can be
achieved only if all owners, operators and pilots cooperate in providing and using the measures available to
them. There will then be no need to introduce legislation
of the kind now applicable to motor cars and other earthbound vehicles.
Don't let this happen to your aircraft! The Cessna and the Hughes helicopter on these pages were stolen by would-be pilots whose
enthusiasm exceeded their expertise.
There are some readers who can still remember the days
when motor cars were functional open affairs - with
canvas hoods the only concession to creature comfort.
Their controls too were simple and straightforward,
with no such refinements as ignition keys and locks instead you simply turned on the very functional ignition
switch before you went about starting the engine on the
crank handle. Yet there wasn't much risk of someone
taking your car. For if you had one, you were nu~bered
among the privileged few and the not-so-lucky c1t1zenry
just stood and watched with varying degrees of awe.
Time marched on and men like Henry Ford and
William Morris came along who thought that cars could
be much cheaper if they were mass-produced. And so it
proved - and the family car became a way of life. But
then alas, so did car stealing, so much so that the
powers-that-be were finally forced to in~ro~~ce
legislation making it an offence to leave your 1gmt1on
keys in your car when it was unattended. Today, to
further reduce the incidence of car stealing, manufacturers are also required to fit a steering lock to their
products.
.
. .
The price of progress bemg what 1t 1s, the same
situation seems to be developing with light aerop lanes.
In the days when aeroplanes were a rarity, they
remained unmolested - except perhaps for the
occasional daring, very enthusiastic souvenir hunter. i:o
the rest of the populace they were untouchable, ex?tlc
machines, flown by no ordinary mortals, that had l~ttle
or nothing to do with everyday life. But a~ the hght
aeroplane has followed the motor car mto mass
production it too has tended to be taken for granted.
Regretfull; as a result, aeroplane stealing has now
become a fact of life.
Motor cars driven by inexperienced but exuberant
and often alcoholically overloaded joy riders are of
course highly dangerous. But an aeroplane. in similarly
irresponsible hands becomes the near-ultimate lethal
17
16
�Look, no engines
An instructor and his student were carrying out circuit
training in a Cessna 310. During this particular exercise
the instructor wished to demons trate the critical performance of the aircraft should it suffer an engine failure
on take-off combined with an undercarriage retraction
problem.
To demonstrate this, the instructor 'failed' the right
engine just after the aircraft had become airborne, using
the mixture control. The student carried out all the correct emergency procedures other than raising the undercarriage, which the instructor had told him to leave down
for the purposes of the exercise. All this was completed
without difficul ty and th e aircraft, a t an airspeed of
104 knots and with the right engine operating at zero
thrust, continued to climb slowly away at about 50 feet
per minute.
About half a mile beyond the end of the runway the
instructor told the student to retract the undercarriage.
But as the s tuden t began to do so, the instructor glimpsed
something moving between the seats . It was the emergency undercarriage extension crank, and he realised that
it had not been properly re-stowed after a previous exercise. The handle had turned a bout one revolu tion when
th e ins tructor saw it. He told the s tudent to lock the handle, as otherwise the undercarriage would not retract. A
few mom ents la ter the li ve left engine failed without
warning, leaving the airc raft without power.
The instruc tor took control, telling the stud ent to continue stowing the handle. He identified the failed en gi ne
and restored full power to the right engin e. H e then carri ed out a quick check a nd fea thered the left en gine as
the aircraft was only just a ble to maintain height 150 fee t
above the sea.
Once the emergency crank had been stowed, the
instructor retracted the undercarriage electrically and
the aircraft began to climb. At a height of 250 feet, the
instru ctor, feeling the situation was now less critical, car-
Acrobatics and structural limitations
ried out a trouble check to find why the left engine had
failed. Checking the fuel, he immediately found that the
left fuel selector (also located between th e seats) was
about h alf a centimetre out of its detent. He moved it
back and then attempted to restart the engine. He had
already decided that if he was unable to res tart the
engine qu ickly he would ignore it and contin ue for a
landing on one engine. After p riming h owever , t he left
engine fired easil y, and so a normal'landing was carried
out on two engines.
It seems certain t ha t the left engine failed because of
fuel s tarvation caused by the fuel selector handle being
out of its detent. Fur ther, it appears that the studen t had
accidentally knocked the selector ou t of position while he
was stowing the emergency extension crank. I n doing so,
the s tudent's fingers would h ave passed very close to the
selector h andle, movi ng in the direction in which it had
been turned. However, he had no recollection of his
fi n gers h aving contacted the selector.
Accidents caused by inad vertent interference with
selectors or controls are by no means u ncommon, a n d
this incident shows again j ust how dangerous such interference can be in a critical phase of flight. These days
controls and switch es seem almost to fill the cockpits of
t win-engi ned retractable und ercarriage aircraft. P il ots
therefore need to develop a continuing awareness of the
vulnerability of these controls.
Wheels down-no light !
At the completion of a lengthy cross-country flight, the
pilot of a light single engine aircraft selected the undercarriage down and prepared for landing, but the green
DOWN lights did not appear. The undercarriage was
cycled but still the pilot could not see the green lights.
The pilot advised Flight Service of the situation and that
he would carry out further checks clear of the circuit
area. These efforts proved unsuccessful so the pilot made
two low passes, one to the side of, and the other over, the
Flight Service Unit. Observers on the ground confirmed
tha t the undercarriage appeared to be down. Emergency
services then stood by while the aircraft la nded safely.
As frequently occurs in such cases, there was no fault
in the undercarriage indicating system. The pilot h ad
18
simply forgotten that when the navigation lights are
turned ON, t he indicator ligh ts ar e automatically
dim med. On a bright day, such as existed at the time of
the incident, it is very difficult to see whether or not the
lights are illuminated unless they are at the normal
illumination for day operation.
Talking in the crew room, or with th eir feet on the bar
rail, few pilots wo uld admit that they are not aware of
this feature. Yet throughout Australia in the past year it
has happened no less t han 17 times! So next time you
find your undercarriage position lights not illuminated
when they should be, think a bout the a utomatic
dimming facility applicable to your aircraft type~
Several months ago the owner of a Cessna 177B became
co ncerned about t he str uctural integrity of his aircraft
when he learned that it had been flow n in aerobatic
manoeuvres.
This type of aircraft is certificated in the normal and
utility categories, and the flight manual lists t he
following manoeuvres as approved :
(a) Normal category:
O perations shall be limited to normal flyi ng
manoeuvres, but m ay include straight and steady
stalls, a nd turns in wh ich the angle of bank does not
exceed 60 degrees. All acrobatic manoeuvres,
including spins, are prohibited.
(b ) Utility category:
No acrobatic manoeuvres are approved except those
listed below:MANOEUVRE
ENTRY SPEED
(I. A.S. )
Chandelles
Lazy eights
Steep turns
Spins
Stalls (except whi p stalls)
100 knots
100 knots
100 knots
Slow deceleration
Slow deceleration
For operation in the utility category, the maximum
take-off weight and the centre of gravity range are more
restricted than the corresponding normal category
limitations. The baggage compartment must be empty
and the rear seat unoccupied. In the Cessna involved in
the incident, a p lacard stating that the aircraft was
certificated in the normal and utility categories, and
giving entry speeds for the manoeuvres listed, was affixed
to the cockpit roof.
The pilot who had hired the aircraft said later he
believed he had complied with the flight manual, by
limiting manoeuvres to spins and chandelles. But when
he described the manoeuvres he had done, it was obvious
that what he thought were chandelles were in fact, stall
turns - manoeuvres which, if mishandled, could impose
structural loads on the aircraft in excess of those for
which it was designed. It was fortunate the pilot did n ot
attempt a lazy eight, for when he was asked to describe this
manoeuvre, he said he thought it consisted of two
consecutive loops with a half aileron roll on the down side of
each loop !
*
* meet the
* requirements of a
Aircraft .a re designed
to
particular operational category which, among other
19
�things, defines the basic strength of the airframe. It
follows that the manoeuvres the a ircraft may safely
perform are determined by this basic strength. The
positive load factor is usually the limiting case, but for
some manoeuvres the limits are dictated by negative load
factors. The categories into which Australian-registered
aircraft are most commonly classified are:
Normal category. The aircraft is usually stressed for a
3.8 g positive load factor. The negative load factor must
not be less than 0.4 times the positive load factor.
Normal category aircraft are limited to non-aerobatic
operations, but may perform unaccelerated stalls and
manoeuvres in which the angle of bank does not exceed
60 degrees.
Utility category. Must be stressed for 4.4 g positive load
a nd again the negative load factor must not be less than
0.4 times the positive factor. Aircraft in this category
may do turns, chandelles and lazy eights with bank
a ngles in excess of 60 degrees, and spins if the type is
ap proved to spin.
Acrobatic category. Must be stressed to at least 6.0 g
positive load. The negative load factor must not be less
than 0.5 times the positive factor. These aircraft may do
any normal aerobatic manoeuvre that is not prohibited
by the Flight Manual or by placard.
'Acrobatic' flight, as defined by the International Civil
Aviation Organisation (ICAO), means 'manoeuvres
intentionally performed by an aircraft involving an
abrupt change in its attitude, an a bnormal attitude, or
an abnormal variation in speed. ' The word ' aerobatic ' is
synonymous with 'acrobatic ' and is the term most widely
used. ' Acrobatic,' o n the other hand, is usually
associated with legislation and regulation, and appears
in Australian Air Navigation Regulations and Orders in
confo rmity with the !CAO definition.
No sensible pilot knowingly operates an aircraft
beyond its structural design limits. The outcome could
be disastrous not only for himself, but also for some other
unsuspecting pilot who subsequently flies the aircraft.
Unfortunately, because the names by which some of the
various aerobatic manoeuvres are known differ
internationally, and even nationally, there may be quite
a number of pilots who are unwittingly subjecting
normal and utility category aircraft to flight loads for
which only acrobatic category aircraft are designed. To
assist pilots in identifying the manoeuvres that are
permitted or prohibited by aircraft flight manuals, the
following common aerobatic manoeuvres are described
under the names by which they are recognised in
Australia.
*
*
Lazy eight - A manoeuvre in which one wing-over is
followed by another in the opposite direction. From the
cockpit, the nose of the aircraft will appear to describe a
figure eight lying on its side, while from above, the
manoeuvre is seen as an S-turn over the ground.
1 ,..... ~
BASIC AEROBATIC MANOEUVRES
*
CO-ORDINATION MANOEUVRES
Chandelle - A balanced manoeuvre in which the
aircraft performs a climbing turn on to a reciprocal
heading. Entry is from wings level at or close to the
manoeuvring speed, and exit is with the wings level just
above the stalling speed.
20
Wing-over - A bala nced manoeuvre in which the
aircraft, from level flight, performs a climbing and
descending turn through 180 degrees, recovering at the
entry height.
Loop
A balanced manoeuvre in which the aircraft follows a
circular flight path in the vertical plane, with the lateral
axis at all times parallel to the horizontal plane. The
elevator is the primary control.
Roll
A manoeuvre in which the aircraft is rolled about its
longitudinal axis (usually through 360 degrees from
wings level to wings level), using aileron as the primary
control.
Stall Turn
A manoeuvre in which the aircraft enters a vertical
climb, is yawed through 180 degrees about its normal
axis with the wings level in the vertical plane, and then
follows a flig ht path reciprocal to that of entry. The
rudder is the primary control.
21
�A number of variations can be applied to most aerobatic manoeuvres. Rolls can be slow, fast, hesitated,
level, climbing, or descending; or combinations of these
variations can be devised. A high performance aircraft
can start a vertical eight at the bottom, do half a loop
followed by a top loop sequencing into the last half of the
first loop, and so on.
COMBINATION AEROBATIC MANOEUVRES
Barrel Roll
A balanced, positive g manoeuvre combining the loop
a nd the roll, in which the aircraft flies a helical path
about a horizontal line in space.
Cuban or horizontal eight
vertical-plane manoeuvre in which the path of the
aircraft describes a figure eight lyi ng on its side. The
a ircraft performs a loop until the longitudinal axis is 45
degrees below the horizon on a heading 180 degrees to
entry, then half rolls to perform a reciprocal manoeuvre.
The tops and bottoms of both loops are at the same level.
~
...
•=•-~
,.
~
.....
Vertical eight
A manoeuvre in which the aircraft performs an upward
loop followed by a half roll and a downward loop, with
entry and exit at the same level and in the same
direction .
Training in aerobatics increases a pilot 's ability to fly
an aircraft accurately and to manoeuvre more precisely
in all regimes of flight. To this end there is a good case
for the use in pilot training of wing overs, chandelles and
lazy eights to improve pilot co-ordination and
judgement, and induce confidence in handling an
aircraft in unusual altitudes.
Aerobatics can be fun and a most rewarding
experience, especially if they are performed in a
professional manner. Skill is obviously important, but so
too is good airmanship. There are, of course, some basic
' rules' to be observed before venturing into aerobatic
flight:
• The pilot must be certified by a rated flight instructor
or other approved person as competent in the
manoeuvres to be performed. The instructor or
approved person may give instruction only in those
manoeuvres they are certified to teach.
• The aircraft must be certificated in the utility or
acrobatic category, depending on the manoeuvres to
be performed.
• Aerobatics must be conducted in an appropriate area.
• A thorough pre-aerobatic check must. be carried out,
a nd updated from time to time throughout the
sequence.
• A continuous lookout should be maintained.
• Each manoeuvre should be planned and the amount of
airspace that will be required carefully anticipated.
• The pilot must be full y aware of his own limitations as
well as those of his aircraft.
• He must exercise caution and commonsense.
Switches and buttons
Reverse Cuban eight
This man~euvre is similar to the Cuban eight, except
that the aircraft half rolls with the longitudinal axis 45
degrees above the horizon and loops downward rather
than upward.
22
Approaching Cape Otway, Victoria, the pilot of a Cessna
207 en route to King Island attempted to pass a posi tion
report but could not make contact with Flig ht Service.
Further checking revealed that there was no electrical
power available. The Cessna returned to base where it
was found that the alternator field switch had been left
OFF. In this particular aircraft the field switch is remote
from the master switch, and the pilot had apparently not
monitored the ammeter during the flight.
In another case, the pilo t of a Cessna 206 was unable
to establish communications a fter take-off. Some 30
minutes were spent trying to overcome the problem,
without success, so the flight returned to base. The
instructor checked the aircraft, operated a couple of press
button switches on the instrument panel and thus activated the audio selector box.
These are only two of 129 similar type incidents that
occurred during 1976, in which pilots lost communication because they did not properly know the aircraft
equipment. Returning to land and then finding that the
fault lies with the pilot and not the equipment not only
costs money but produces red faces. Both can be avoided
by a little more time spent reading decals or ensuring
you know what each switch, knob or button does - before take-offi
23
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This is the second part of a series of articles on Search
and Rescue in Australia and how it concerns you as a
pilot or aircraft operator. In Part I (Digest No. 101 ) we
posed some questions which would probably spring to
your mind if you were to become involved in a SAR
operation. This part answers some of these questions as
well as giving a brief outline of the Australian search and
rescue organisation, its lines of responsibi lity and the
way in which it functions.
The Air Navigation Plans of the Interna tional Civil
Aviation Organisation (ICAO) divide the world into
a reas for which responsibility is allocated to an ICAO
Contracting State. A similar situation exists with marine
operations a nd, under the Inter-governmental Maritime
Consultative Organisation (IMCO), maritime SAR is
provided in geographic areas aligned as closely as
possible to those of ICAO.
The area allocated to Australia is one of the largest in
the world . It extends from between two and 10 degrees
South, to the South Pole, and from 75 degrees East (2500
nautical miles west into the Indian Ocean) through 88
degrees of longitude to the mid-Tasma n sea. It
encompasses about 18 Y.! million square nautica l miles,
- more than one square mile for each head of our
population - and altogether nearly one eighth of the
earth 's surface.
Almost every possible type of environment is found
within th is area, from tropical jungle to pastureland
plain, from parched desert to icy polar waste and of
course vast tracts of ocean.
M ajor air routes cross the continental and oceanic
areas for which we are responsible and busy shipping
lines operate to and from major ports around our coast.
Domestic aviation of various kinds operates throughout
the country and across Bass Strait, while marine coastal
traffic and fishing vessels, together with yachts and a
wide range of pleasure craft, ply the entire coast. The
total number of these movements runs into hundreds of
thousands. On the land also there has been a dramatic
increase in bush walking and other related outdoor
activities, and parties of school children camp frequently
in our national parks.
Any of t hese activities; in any environment a nd at any
time, may generate a search a nd rescue act ion. The costs
associated with permanently maintaining personnel a nd
equipment to provide such a n enormous SAR coverage
would obviously be immense, and to cope with the
situat ion a system has been developed by the various
Australian SAR a uthorities that is to a large degree
based on mutual co-operation.
There are three recognised SAR authorities: the
Department of Tra nsport, the Department of Defence,
and the police forces of the various States a nd
Territories. These are assisted from time to time by
va rious volunteer groups which have been formed
throug hout the country and are supported by either
interested local groups or charitable organisations.
Within the Department of Transport there is both a n
air and mar ine SAR element. For air operations, the
Depa rtme nt maintains ten R escue Co-ordin ation
Centres, each serving the Search and Rescue Region in
which it is located. In addition there are six sub-centres
ava ilable fo r immediate ma nning should a SAR action
become necessary in a remote area.
These ce ntres are manned by Operational Control
officers tra ined at the Department 's Search and Rescue
School at its Central Training College in Melbourne. On
completion of an intensive seven weeks' course, officers
graduate as SAR Mission Co-ordinators or Assistant
SMC's according to the level of expertise demonstrated
and the depth of experience attained. These officers have
the responsibility of co-ordinating search and rescue
activity for missing civil a ircraft as well a~ for air
searches for m issi ng vessels made on behalf of the
Department 's marine element.
The SAR course at the Department 's Central
Training College is based on the syllabus used by the
United States Coast G uard in its training school at
Governors Isla nd, New York, but has been extended to
cover the specia l conditions enco untered in the
A u st ralian environment. In addition to the
Department 's air and marine SAR personnel, the school
trains officers from each of the Defence forces and from
State and Territory police forces , as required.
Standardisation is thus ensured amongst the various
authorities concerned and each has a working knowledge
of the functions, responsibility and expertise of the
others.
Departmental marine search and rescue responsibility
is discharged through the Marine Operations Centre, a
central facility located in Canberra. It is responsible for
all ships operating under the Australian Navigation Act,
including all vessels engaged in international or
interstate trade or commerce. In addition to the SAR
function, the Marine Operations Centre handles the
Australian Ship Reporting System (AUS REP ),
bro a d casts of na viga tion a l warnings (a marine
equivalent of our NOTAMs) a nd the co-ordination of
coastal surveillance.
The role of the Department of Defence in the SAR
organisation is that of providing SAR for missing land,
sea or air units of our naval, military or air forces.
However it also plays a significant role in the civilian
area by providing facilities wherever possible to assist in
specialised tasks. In many instances, particula rly those
at sea, the only suitable aircraft in terms of range and
navigational capabi lity are those of the RAAF. T he
Department of Transport, thoug h bearing the overall
responsibility for such a SAR action, relies heavily on the
Department of Defence for this assistance.
The third SAR aut hority in Australia is made up of
the police forces of the various States and Territories.
Bas ically their responsibility is for perso ns lost on land
such as bush walkers and hikers, and for the rescue of
people involved in boating accidents close to the coast.
As already mentioned, Australia does not maintain
aircraft or crews exclusively for SAR operations. Instead
the most suitable available aircraft are called upon for
the task in hand. Clearly in the long-range oceanic case,
the most suitable aircraft are those of the RAAF.
H owever, in a search close to the coast or in inland areas,
it is often preferable to use local operators. Not only do
their pilots know the area, but they are usually more
readily available and the type of aircraft they operate is
usually the best for local conditions. For instance, in
mountainous country it is often better to use a high-wing
light aircraft which will afford the best visibility as it
banks and turns around the contours of the hills.
Similarly, a local operator's light twin-engined aircraft is
often the better choice for a search for a missing boat,
especially when the positioning of a milita ry a ircraft
from a base such as Edinburgh or Townsville wo uld be
25
�Frost, ice and snow ·
Warnings about. the danger of taking-off with Ice or snow on the wing or tail surfaces of an aircraft are of
limited application in Australia. However, a seasonal reminder of the aerodynamic effects of even a thin
coating of frost could be timely for all pllots.
time-consuming and expensive.
Among the most common SAR actions are those
relating to boating accidents close to the coast, and civil
pilots quite frequently become involved in this type of
search. Sometimes the police use their own aircraft, but
more often an aircraft is chartered to carry out a
surveillance flight. In this situation the flight is a normal
charter operation and is required to conform to the usual
charter requirements.
·
In most cases a search aircraft is organised through
the appropriate Rescue Co-ordination Centre. In this
instance the request for the aircraft will originate from a
rated SAR Mission Co-ordinator who has the authority
to initiate the air search, to vary the requirements of
certain of the Air Navigation Regulations in order to
facilitate the search,. as well as to authorise expenses
incurred in it.
Under various Co mmonwealth-State agreements, the
Australian Government provides assistance to State or
Territory authorities when an emergency situation ·
warrants facilities that are beyond the capability of the
State. Thus when State police authorities are confronted
with a wide-scale search for a missing vessel, they may
approach the Department of Transport to assist with
expertise, facilities and finance. Initially the State
request is directed to the Department 's Marine
Operations Centre (MOC ). Upon receipt of such a
request, MOC assumes responsibility for the overall coordination of the SAR action and will review the area to
be searched, taking into account ocean currents, drift
factors, winds and all available intelligence.
MOC will warn surface vessels of the situation a nd
organise a surface search . .If, as is usually the case, the
area is so large that it must also be searc_hed by air, the
MOC will pass the air search responsibility to·one of the
Departmental RCC's. The duty SAR Mission Coordinator will then deCide on the most suitable aircraft
for the task, taking into account location, availability of
crews, range, visibility potential, supply drop capability
(if necessary), and other such factors.
The SAR Mission Co-ordinator then advises the
aircraft operators and crews of what is required and
prepares appropriate briefing material for them. From
this time onwards the RCC is responsible for all civil
aircraft involved in the search and for such matters as
operational control, separation from other aircraft, crew
hours, search patterns, altitudes, track spacing and crew
accommodation.
One of the prime functions of a SAR operation is of
course that of survivor rescue and a mission is not
deemed accomplished until all survivors are returned to
safety. Between the time that survivors are first located
and when they are picked up, a number of steps may
have to be taken.
Basically the task is simply to pick them up. Normally
this is carri<;d out by a land party if the survivors are on
the land, or a ship if they are in the water - or in some
instances by a helicopter. But in many cases survivor
retrieval is anything but a simple straightforward task
and some time may elapse between the original sighting
and the pick-up. For this reason the D epartment
maintains droppable equipment which will sustain the
survivors throughout that peiiod.
Droppable equipment is strategically located at
centres througho ut the country. It consists of water
supplies, supporting rations (for both land and marine
situations), first a id kits, signalling a nd communications
equipment, as well as flotation equipment such as liferafts a nd life-j ackets. Specially constructed dropping
boxes and containers have been developed for delivering
the equipment to survivors. Normally a ' Helibox' is
dropped over land and marine rescue kits are dropped to
persons in the water. There will be more on this topic in
a later iss ue.
Supply dropping can be conducted only from aircraft
approved for the p urpose and necessitates specific
approval for flight with the doors open or off. If a marine
kit is to be dropped, an exact flight procedure must be
used and, because several pieces of equipment are roped
together and despatched in sequence, the dropping of
this equipment should not be attempted by untrained
personnel.
The Department has specially qua lified 'Dropmasters' located at aerodromes at which marine rescue
equipment is held. There are a lso ATC staff who can
give a n untrained pilot detailed briefing on the flight
patterns to be flown a nd the signals he will be given to
ensure accurate delivery of the equipment. The A TC
officers will accompany the pilot and assume responsibility for despatching the equipment a nd the associated
cabin safety.
In addition to the RCC staff and Dropmasters, the
Department have available qualified Observer Leaders
and Observers. Volunteers for this purpose are drawn
from various areas within the industry a nd all have been
trained in observation techniques most likely to be
successful. These observers a re allotted to the pilot as
part of his search crew, at the discretion of the SAR
Mission Co-ordinator.
The next part in this series will discuss 'How search
areas are calculated' .
As pointed out in previous issues of the Digest,
a lt hough a coating of frost hardly affects the aerofoil
shape of the w ing, the fros t 's surface roughness increases
drag, destroys the smooth flow of air over the aerofoil
and raises the stalling speed b y promoting ea rly airflow
separation. For this reason, an aeroplan e coated with
frost can fail to become airborne at t he norma l take-off
speed a nd, even if it does m a nage to struggle into the air,
the ma rgin of airspeed above the stall will be lessened so
t ha t only a medium t urn or moderate turbulence can be
sufficie nt to induce a stall.
The ma in effects of ice or snow on an aerofoil are to
disturb t h e normal airflow ove r its surface and to alter
the distributio n of weight . This can result in increased
dr ag, loss of lift, decreased control, flutter of the surface
or all of these facto rs combined in varying degrees. The
vita l fac tor is the d istribution of the ice or snow
fo rmation on the surfaces, rather than the additional
overall weight increase to the ai rcraft . The formatio n of
~ice ,or snow creates changes in aerofoil contour, and
co ntrol a n d servo-tab surface mass imbalance, which
may lead to separatio n of airflow a n d in some extreme
cases, dynamic instability of the surface .
If the ice formation is asymmetrical, large differential
loads bet ween t wo lifti ng surfaces may develop to a point
that the a ircraft can no longer be controlled. Ice
formation on the leading edge of a control su rface or
servo-ta b also creates a potential buffeting condition.
T his is particu larly true at surface deflections where the
iced portio n of t he control surface leading edge protrudes
above or below the trailing edge of the primary surface.
F or t hose who require evidence, the following accident
a nd inciden t reports are reproduced from a brief
p ublished by the Aeronautical Research Institute of
Sweden:
• A twin-engine ST O L aircraft went into an outside
loop when rhe fla p was lowered. Cause: Ice at the
leading edge of the tailplane resulted in tailplane stall.
T he aircraft 'recovered' upside down after a 180
degree 'bunt'.
• The crew of a twin jet transport almost lost pitch
co ntrol as a result of tailplane icing when flap was
lowe red duri ng their approach to land . Flow
sepa ra tions caused by the ice had large effects on trim
a nd pi tch control effectiveness.
• A light twin propeller-driven aircraft lost altitude and
cras hed after lift-off. Cause : Frost on wing combined
with wind shea r. Frost can increase the stalling speed
by as m uch as 20 to 30 p er cent.
• A medium-sized twin j et transport rolled to the left
immediately after lift-off. T he pilot saved the day by
resettling the aircraft on to the slippery runway and
continuing acceleration to a highe r take-off speed. A
successful lift-off was finally made near the runway
end. Cause : Patches of snow sticking to the left wing.
The wings had b een brushed clean but the person
sweeping the left wing had not removed the
compressed snow from his own foot-steps!
• A swept-wing twin jet pitched up after lift-off. The
crew pushed the control wheels 'into the instrument
panel' to prevent a stall. Cause : Frozen snow on the
wing surface near the wing tips resulted in early wingti p stall, shifting the lift force resultant forwa r d and
producing a high risk of over-rotation.
• A light twin-engine propeller-driven aircraft used
twice the normal take-off distance, then stalled at liftoff. Cause: Ice frozen under light snow on the wings
increased both drag and stalling speea. The pilot had
brushed off the snow but had let an 'insignificant'
amount of ice remain on the upper wing surfaces.
• A light single engined aircraft ' mushed ' back on to
the ground after lift-off. Cause : Ice on the upper wing
surface. The pilot believed that light snow would blow
off the wing but forgot that aircraft was warm when
taken out of its hangar. The snow· closest to the wing
surface melted, t hen refroze on the wing.
In regions where such climatic conditions prevail,
aircraft should be t horoughly examined for ice and snow
deposits just prior to flight to ensure that:
• All skin surfaces are clean and entirely free of frost, ice
a nd snow.
• Propeller blades and hubs are inspected and any frost,
ice or snow is removed.
• All control hinge points and control surface openings
are checked for freedom from ice and snow.
• All antennae and antenna fittings are free of ice and
snow deposits.
• Nose and main undercarriage assemblies, including
drag linkages, up-latches and door operating linkages,
are clear of ice and snow.
• All heater and supercharger air intake duct openings
are clear of snow and ice depos its.
• Engines are warmed-up in a n area free of slush and
moisture, lest the propellers pick it up and throw it
back over the wings, tail surfaces and fuselage.
• After engine warm-up, all flight controls are checked
through their full ra nge of travel to m ake certain th at
they are not restricted by packed ice or snow in areas
where visual inspection is difficult.
26
27
�r-- -
Birdstrikes
The majority of collisions between aircraft and the birds w ith whom we
share the sky do not result in significant damage to the aircraft. Since
the beginning of man's airborne adventures, however, birdstrikes have
occurred frequently enough for concerned aviat ion authorities
throughout the world to investigate the hazard posed by such collisions
and to conclude that measures arc necessary to reduce the effect of
them.
The first recorded fata l aircraft accident resulting from a birdstrike
occurred in 1912 when a seagull became enmeshed in the control
cables of a Curtiss Flyer. Since then birdstrikcs have led to several fatal
aircraft accidents; the one with the greatest loss of human life being the
crash of an Electra which encountered a flock of starlings on take-off
from Boston U.S.A. in 1960 in which sixty-two of the seventy-two
occupants were killed.
In Australia there has not been a fatal civil aircraft accident
attributed to a birdstrike though there have been several accidents in
which the aircraft was substantially damaged. In December 1969 a
Boei ng 707 abandoned take-off at Sydney Airport after encountering a
flock of seagulls. The aircr aft overran the runway and the la nding gear
was torn from the fuselage. T hough there were no injuries to the 136
occupants of the aircraft , the substantial airframe damage required
extensive repairs.
The pilot of a Piper PA25 aircraft engaged on agricultural
opera tions wou ld also testify to the potential danger of birdstrikcs.
While spraying a crop in Western Victoria during November 1977 the
aircraft struck a wedge-tailed eagle which appeared to be attacking the
a ircraft. The bird had a wing span of two metres. After dumping the
re maining sp ray, the pilot checked the aircraft for controllability and
then la nded at the nearby agricultural strip. The outer portion of the
left wing was severely damaged by the birdstrikc .
Reduction of the birdstrike hazard has responded in the past to two
particular approaches
- construc ting aircraft to withstand birdstrikcs
- separat ing aircraft and birds
Strengthening aircraft components to withstand birdstrikes inevitably
results in an increase in a n aircraft 's weight with a consequential
decrease in its performance and payload. Therefore b,efore such
requirements arc imposed on manufacturers and operators, it is
necessary to establish clearly all of the factors involved in birdstrikes.
The types of aircraft and birds, the aircraft speed and altitude at which
s trikes occur, the phases of fli ght of the aircraft a t the times of the
s t rikes and the nature and extent of the damage resulting need to be
colla ted to form the basi·s for specifications for aircraft airworthiness
cri teria.
ln 1%5 !CAO requested i'vl ember States to contribute to a program
of reporting a ll birdstrikes so that t he necessary information was
avai lable to the organisation's Airworthiness Comm itt ee concerned
with developing airworth iness standards. This information led the
Organisat ion to develop re,·iscd airworthiness s t;rndards for airframes
and e ngi nes of a ircraft over 5700 kg maximum gross wei ght. R ecently
in 1he Uniied Kingdom the revised airworthiness requirement s were
extended to apply to all aircraft manufactured in tha t couniry. Aircraft
components constructed to meet the revised standards improve the
damage tolera nce of modern aircraft to the effects ofbirdsirikes.
Revision of the airworthiness standa rds howeve r does not assist in
28
reducing the frequency of bird strikes. To do this ways of separating
<iircraft and birds need to be found. Data al ready gathered on
birdstrikes shows that most occur in the vicinity of aerodromes, where
aircraft arc at low altitudes and in the environment where birds spend
the majority of their time. Clearly, then, efforts to achieve separation
between birds and aircraft need to be directed to the aerodrome and its
vicinity.
Australian experience has shown that a combination of correct
environmental management techniques to reduce an aerodrome 's
attractiveness to b irds, combined with the use of bird dispersal devices
can significa ntly reduce the birdstrikc problem. Sydney Airport is an
example where the closure of nearby rubbish tips, the improvement of
airport drainage and the operation of mobile bird d ispersal patrols
have resulted in a greatly reduced bi rdstrike risk.
T o select and apply effective bird control techniques nationally it is
necessary to acquire detailed knowledge about the bird characterist ics
and behaviour a t each individual aerodrome. Variations in the
environment of different aerodromes can result in varying numbers of
species of birds inhabiting the aerodromes. Clearly there are
differences between the bird populat ions and behaviour a1 H obart and
Alice Springs. Local factors such as the presence of water, crops,
abattoirs etc. in the vicinity of an aerodrome can also affect the pattern
of bird species and movements found on and around the aerodrome.
Though in the preceding paragraphs we have been discussing
birdstrikes in the vicinity of aerodromes, the Department 's iniercst in
the subject is not confined to such strikes. We are interested in
birdstrikes occurri ng in all circumstances and involving all cat egories
of aircraft - airline, general aviation, reciprocating and turbine
powered. If information on all birdstrikes is available, it may enable
geographical and seasonal patterns of bird movements to be
established so that pilots may be warned what to expect from birds and
steps taken to separate ihe b irds and aircraft.
This article, and the post er opposite, introduce a De partmental
campaign to improve the re porting of b irdstrikes in Aust ralia. T he
airlines and the Austr~lian Federation or Air Pilots have pledged their
support, and we a re seeking support from a ll other sections of the
aviation industry in a combi ned effort to reduce this hazard by better
understanding of the problem.
Special birdstrike report forms have· been printed for the campaign.
Three different f"onns arc used
ffe\~@lf Q:Q ~[g ffe:\O ~@~~lf(f
a-O Olf~ ~llil~ ~@)(f
for pilots to report deta ils such as the type of aircraft involved,
speed, altitude, p hase of llight etc.
for Airways Operations personnel t o provide details of weaiher,
e tc.
for the Ai rport ground personnel to report on bird carcasses
recovered, the runway location , possible so urces of aitraction for
b irds, and other pertinent informa tion .
Piiots are urged to complete their form whenever they experience a
birdst rikc. T he forms can be ob1ained a t night briefing offices during
the ca mpa ign a nd completed forms may be lodged a t a n y Airways
Operations Uni!.
·!'he solu tion to the problem of bi rdstrikes lies in the analysis or the
data reported. Each report provides additional data on a n aerodrome's
bird species and habi ts. When a ll such reports are analysed location by
location over a period of ti me the particular problem at each location
may become evident. The Department is utilising computer facilities to
collate recorded birdst r ikc information so that the data o btained
therefrom ca n be easil y stored and readily ret rieved for analysis. This
will be done and specific studies initiated and conducted by specialist
officers within the Deparl!nent . The need for corrective measu res will
then be determi ned a nd appropriate action take.n to reduce the
birdstrikc hazards identified. Bird Hazard Committees have been
established in Central and Regional offices of the Depa rtment to
coordina te the ca mpai gn and the re media l act ion.
This campaign is a su stained effort to gather information from which
the extent of the hazard presented by the Austra lian b ird populati on to
aviat ion may be assessed. T he s uccess of the ca m paign requires the full
participa tion of a ll readers of the Digest . Your assistance in this rega rd
by reporting all birdstrikes you encounter will help ensure this success.
FOR SAFETY'S SAKE
*
.I
REPORT THAT BIRDSTRIKE
�
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Aviation Safety Digest, number 102 (1978)
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102
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1978
-
https://collections.heritageoftheair.org.au/files/original/027fb02d60dde2e5550163a12f25a967
373c7db9013561a66617c8250bcfcccb
PDF Text
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-~1
Number 101 1978
Aviation Safety Digest
�For almost 30 years. the unmistakable profile of tile Bristol Freighter has
been a familiar sight 1n Australian skies. Now. with re ti rement for the last
remaining examples JUSl around the corner. the Digest pays tribute on
the covers of this issue to one of the true workhorses of av1alion.
Though by toda/s standards slow and relalively unsophisticated. when
1t went into produclion in 1946 the F re1ghter was ahead of its time as
a short haul. high capacity cargo transport. With large clamshell doors
prov1d1ng nose loading capability. it has a carrying capacity unmatched
even today by some aircraft of similar size.
The Freighter was produced 1n several versions. The aircraft featured
1n our cover pictures 1s a Mk. 21. unique in that 11 1s believed to be the
only Freighter of this model slill flying anywhere in the world. Now owned
by the Essendon-based cargo airline Air Express Lid.. the aircraft first
flew in March 1949. After a brief two weeks w ith the RAF. the aircraft
was acquired by the RAAF. who operated it until August 1969. Released
then by the RAAF. the aircraft began civil operations. first with a newly
formed charter company and finally with Air Express. who bought the
aircraft in April 1971.
With the introduction of newer ai rcraft types and more specialised cargo
handling techniques. the Freighter 1s becoming outclassed 1n the highly
compet1live world of air cargo transportation. Two Freighters however.
the Mk. 21 and a later Mk. 31. have been retained 1n the fleet of Air Express to operate shorter flights such as the services across Bass Strait
:o King Island and Tasmania. and also to cope with any unusual items
0f load that cannot convenientl y be earned in other types.
Operating mainly at night. the Freighter continues to perform an
unglamorous but vital task for which its basic advantages as a cargo
aircraft. though to some extent superseded by other types. are still
uniquely suited.
Aviation Safety Digest
Number 101 1978
CONTENTS
Disastrous Indecision ................................................ 2
You - and Low Level Jet Routes ............................ 5
What Can Go Wrong - Will I ..........•.....................••.. 7
Cherokees Collide Head-on ...................................... 8
Ooopsl ....................................................................... 10
Eyesight Is Precious ................................................ 11
A Nasty Situation ..................................................... 12
'What! You Threw Away the Ripcord?' ................. 14
It's Good Advice For Us, Tool ................................ 17
The Wrong Side of the Power Curve ..................... 18
A Close Calll ............................................................. 19
Dust Devils and Aviation ......................................... 20
Ask For Help - While You Still Can! .................... 22
The Breath of Life .................................................... 23
Counting Sheep? ..................................................... 24
Incredible! ................................................................. 25
Recognising and Handling Dangerous Goods ..... 26
Your Role In Search and Rescue ........................... 28
Aviation Safety Digest is prepared in the Air Safety Investigation Bra~ch
and published for the Department ef Transpurt through. the Australian
Government Publishing Service, in pursuance qf Re.i:ulat1on 283 ef ~he
Air Navigation R egulations. It ~s distribu~ed fru .ef charge to Australian
licence holders (except student ptlots), regtstered atrcraft owners, an~ certain other persons and organisations having a vested operational interest
in Australian civil a1~ation .
A viation Safety Digest is also available on subscription fiom the
Australian Government Publishing Service. Enquiries should be addressed
to the Assistant Director (Sales and D istribution), Australian Gooemment
Publishing Service, P. 0. Box 84, Canberra, A.G. T. 2600.
@ Commonwealth ef A ustralia 1978. The contents ef this publication may
not be reproduced in whole or in part, without the wrilltn authonty ef the
Department ef Transport. IVkere material is . indicated lo . b~ extracted from
or based on another publication, the authonty of the ongrnator should be
sought. The views expressed by persons or bodies in articles rtf'.roduced
in the Aviation Safety Digest from other sources are not necessanly those
ef the D epartment.
Change ef address: Readus on the Department's. free distributi~n list
should notify their nearest R egional Office. Subscrzbers should notify the
Australian Government Publishing Service.
Printed by Ruskin Press, 39 Leveson Street, North M elbourne, Victoria.
RM76/302 16( 1) Cat. N o. 78 9098 S.
Note: Metric units art used except for airspeed and wind speed which are
given in knots; and for elevation, height, and altitude where measurements
are given in feet.
�While landing at St. Thomas, Virgin Islands, after a flight from Rhode Island, U.S.A., a Boein~ 727-100
over-ran the end of the runway and crashed. The aircraft caught fire and was destroyed. The flight crew
survived but 37 of the 88 occupants were killed. Thirty-nine others, including one person on the ground,
were injured.
The captain, con cerned th a t he would not be able to
Although visual meteorological conditions prevailed,
the crew elected to fl y the ILS to assist in vertical
guidance during the approach. Witness observations,
crew statements, and information derived from the fl ight
data and cockpit voice recorders all indicate that the
aircraft approached the 1420 metre 09 runway in a normal profile which would result in a touchdown goo
metres or slightly more beyond the threshold. Instead of
touching down as expected, however, the aircraft floated
fi ve to ten feet above the run way and touched down
about 850 metres beyond the threshold , leaving some 570
metres of runway and 155 metres of over-run in which
to s top.
stop in this remaining distance, decided to go-around. I t
then seemed to him that the engines were not accelerating quickly enough, so he again closed the power .levers
and attempted to bring the aircraft to a stop. The aircraft
over-ran the end of t he runway a nd the 155 metre overrun tore its way through the perimeter fence, crossed a
road, des troying several cars as it did so, and finally c~me
to rest in a service station where it bu rned to destruct10n .
Subsequent investigation e~ tablished_ that had t he captain continued with the landmg, the aircraft could have
been brought to a stop in about 54~ metres, b~t the runway length remaining was insufficient to achieve a safe
go-around.
rn~~ffi~TIWW[]J~
INDECISION
(Co11densed.from report published by National Tra11sportatio11 Safety Board, U.S.A.)
*
*
*
Guidelines issued to pilots flying the company's Caribbean routes lay down the company policy concerning
flap usage, aiming p oint, touchdown point and goa round , a nd point out the possibility of encountering
downdraughts on the approach. T hey emphasize the
necessity of being in the 'slot', the importance of the goo
metre aiming point, and the possibility of wind shear
which could p roduce a float if the aircraft is landed beyond the goo metre poin t. T hey also point out the necessity of executing a go-around if the approach is not in
the slot, if the landing is going to be appreciably beyond
the goo metre point, or if a bounce occurs on touchdown.
The use of 40° of flap is standard practice; however, the
use of either go0 or 40° flap 'with strong, gusty winds' is
op tional. The use ofgo0 flap is recommended with a wind
component of20 knots or more. In this case the crew had
been told that the surface winds at St. Thom as were from
120° at 12 to 14 knots . No gusts had been reported.
The captain said , however, that he knew that any
south-east wind at St. T homas would be gusty and therefo re decided to use go 0 of flap. H e said that with go 0 of
flap the a ircraft is more controllable, is easier to manage,
a nd that, 'you have a greater margin for what is ahead'.
But having made the decision to use the non-standard
flap setting there was no evidence that the crew had
checked their landing analysis chart to see if the landing
was permissible. Had the y done so they might have been
rem inded that a 20 knot headwind component was
required for a goo fla p landing.
The decision to use go 0 rather than 40° flaps exposed
the air craft to a performance penalty, increasing the
r equired landing distance by 76 metres. More importantl y, the reduced drag made the aircraft more vulnerable to th e effects of increased a irspeed, and any wind
shear or gusts would be more apt to produce a float. I n
the actual approach, the captain a imed for a 10 knot
margin above the reference speed, and as the aircraft passed over the threshold the margin was 11 knots. The
Board believes that, when the cap tain attempted to flare
the aircr aft, this excess speed above reference was a factor
in overflyin g the aimin g point.
The a p proach to the threshold was nevertheless flown
normally with the aircraft stabilised in tl1e landing config uration and wh en over the threshold the power levers
were retarded according to procedures, to arrive at the
touchdown point with idle power. Evidence indicates
th at the aircraft's wheels were about 10 feet above the
runway at the goo metre aiming point, and touchdown
appeared imminent. Thus, there was no reason to suspect
that a go-a round might be necessary and the captain's
thought processes were probably orientated to control of
the aircraft on the the ground.
T he flight data recorder showed two airspeed aberrations had occurred when the aircraft was slightly beyond
the 300 metre marker, which were probably the result
of a gust. T his caused a lateral upset of the aircraft sufficient to cause an exclamation of surprise which was
audible on the cockpit voice recorder. The airspeed
increased about five knots, the aircraft rolled to the right
and as a result the captain was unable to land before correcting the upset. More critically, the aircraft was still
ten fee t above the runway and well bey ond the normal
touchdown point. The Board believes the gust encoun ter
added to the lift already produced by the rotation of the
aircraft in the flare, and caused a prolonged float. T he
captain was thus faced with an immediate decision to
land or to initiate a go-around and at that stage he forced
the aircraft on to the runway. But though he knew he was
past th e normal touchdown point, the extent of the aircraft's progress down the runway became evident to him
only after touchdown when his visual appraisal of the runway made him change his mind and initiate a go-around.
T he captain had extensive operating experience into St.
T homas. In this case the aircraft was about 150 metres
short of the point at which it would normally be rotated
fo r take-off and the airspeed was at or within three or four
knots of rotation speed . Thus, tl1e cap tain 's experience led
him to believe that a go-around was a viable course of
action. T he aircraft was, however, in a diminishing speed
regime and the engines were spooled-down.
The limited training for touch-and-go landings which
most airline captains receive during their type-conversion
is cond ucted under ideal conditions. Both airspeed and engine RPM a re maintained to the maximum extent possible and the training is usually conducted on runways of
such length that maximum performance is not a consideration. Pilots are taught th at accidents which result from
misjudged approaches can be averted by going around,
but as demonstrated in this case, they may have little
knowledge of the distance actually required to execute a
go-around under varying conditions of temperature, elevation, velocity, gross weight, and engin e spool-down.
The inves tigation confirmed that the engines had in
fact responded to the movement of the thrust levers,
which had been advanced in accordance with a laid
down 'two-step' procedure to allow the engines to
stabilize at l. 4 EPR. T hus from the time the captain decided to go-around, it would have taken six to seven
seconds for the engines to accelerate to take-off power.
�APPROACH PROFILE
U.GtND
CAM COCKPIT AAtA MICROPUONE
CAM 1 VOICE IDENT I FIED AS CAPTAIN
CAM 2 VOICE IOENTIF1£U AS FIRST OFFICER
CAM J VOICE: 10£Nllfl£0 AS FllGHJ ENCINEER
~
NON PER l INtNT WOAOI SI
200'
200'
loo'
100'
so'
50'
RUNWAY
THRESHOLD
During at least part of this time the aircraft would have
con tinued to decelerate. Analysis ofBoeing 727-100 performance data sqows that from the initiation of full power
during a touch- and-go, more than 580 metres of runway
is required to lift-off, while another 240 metres is needed
to reach an obstacle-clearance heigh t of 35 feet. In addition , the 'two-step' ad vance of the power levers can
leng then the take-off roll by as much as 150 metres. These
figu res compare with a stopping distance of abou t 520
metres using maximum wheel b raking and other available braking devices.
The Board therefore concluded t hat a successful goaround could not have been executed when the captain
attemp ted to do so, but that using maximum braking and
spoilers, he should have been able to stop the aircraft on
the runway a nd certainly within the confines of the runway over-run.
The final events in the accident sequen ce th us occurred
when the captain real ised that the rate of engine acceleration would not allow the aircraft to become safel y airborne in the remaining runway length a nd he closed the
power levers and applied full wheel braking. T yre marks,
indicative of braking, were visible abou t 210 metr es before the end of the runway. However, for a time, at leas t
until the aircraft left the over-run, the captain did nothing more than this to bring the aircraft to a stop. H e did
not lower the nose wheel to the ground, did not extend
the spoilers, and did not use reverse thrust. As a result,
the aircraft failed to deceler ate to its full capability. Not
lowering the nose probably had a significant effect on the
deceleration, as the lift being developed affected the
re tarding force transmitted from the tyres to the runway
surface. Though reverse thrust was apparen tl y selected,
it was not applied until just before final impact.
T he captain said that he d id not know why he did not
use all the available means of deceleration . Research in to
human behavioural patterns indicates, however, that
when d anger appears imminent, man may undergo certain behavioural changes intended to ex tract him rapidly
and impulsively from such a situation. This so-called
'emergency mechanism ' may be detrimental in situations
where deliber ate responses are necessary because it cancels the reasoning function.
page4
In this case, the 'emergency mecha nism' was trigger ed
when the captain realised that a go-ar ound was impossible
and an accident inevitable. The captain probably reacted
impulsively and ins tinctively by applying full wheel
brakes, but did not remember the more deliberate actions
of lowering the a ircraft nose, deploying the spoilers, and
applying maximum reverse engine thrust. H ad he used
these means of deceleration when he commenced braking,
the aircraft migh t have been brought to a stop within the
confines of the airport perimeter. At th e very leas t, a much
lower-velocity impact would have occurred.
The Board believes that intensive training is the most
effective means to combat such reactions. H ad th e captain been exposed during training to critical go-around
situ ations and to the maximum performance stopping
capabilities of t he aircraft by means of flight simula tion
and lectures, he may have reacted appropriatel y.
In summary, it is evident t ha t the captain had two
opportunities to avoid this acciden t. His first.was during
the turb ulence encounter just after passing the 300 metre
touchdown area; he should have followed company
procedures and initiated a go-around as soon as he
regained control.
His second opportunity came after he had landed the
aircraft. H e should then have applied maximu mperformance stopping procedures to bring the aircraft to
a stop within the r emaining runway length. Subseq uently, when an accident became inevitable, the captain could have lessened the impact b y using all available
means of d eceleration.
The Board concluded that although the captain
realised the remaining runway length was critical with
regard to stopping the aircraft, he did no t know that the
remaining runway was even more critical with regard to
the execution of a go-around. With adequate training as
to the aircraft's performance capability an d with training
environmen t exposu re to similar situations, the captain
may have reacted immediately to stop the aircraft instead
of attempting to go-arou nd.
You - And Low Level Jet Routes
The pilot was a careful man - one who did not like
surprises when he was flying - especially when he had
his family on board. This time, befor e flying his wife and
two young sons to visit her parents' farm in a Cessna 172,
he had checked the weather carefully. But as the trip was
less t han fifty miles over countryside he knew like the
back of his hand, he did not lodge a flight plan. Even
so, he had taken the trouble to m ake certain his charts
and other documents were current and as usual he had
meticulously pre-flighted the aeroplane. Certain that all
was in order on this mild, sunny, winter's day, they flew
leisurely ou t to the fa rm.
But d espite all his care, the pilot was in for the fright
of his life. As he gently banked the Cessna over the farm's
grass strip in preparation for his approach to land, he
caught just a glimpse of a military jet, sinister with armamen t and camouflage, as it flashed very close beneath
his upraised wing at what seemed impossible speed. H is
children shrieked, his wife gasped, horrified, and for
several bad moments he found his hands full coping with
the ensuing turbulence. At least it gave him time to parry
the barrage of questions - 'What was that?' 'W hat's that
jet doing over our farm?' ' Why was he so low over our
strip?' For the moment the pilot just didn't know. Then
he remembered a loose-leafed folder in his flight bag that
he had hardly ever looked a t. I ssued by the Department,
it was entitled 'Military Low J et Routes'.
Leafing through this folder after he had landed safely
pages
�and his family had recovered from their fright, the pilot
saw to his dismay that the farm strip lay directly beneath
the flight path of an officially designated Low Je t Route.
He also realised that the high speed military aircraft
which had missed them by so little was probably a
Mirage jet fighter being flown on a ground-hugging exercise at near the speed of sound!
How was he supposed to a void such dangerous and
unexpected traffic? The more the pilot thought about it,
the more concerned he became. He just did not know
the answer and remained in troubled ignorance for the
next several days until he got back to his base and called
in to talk to the Flight Service Officer on duty. There
he learned that, had he availed himself of the unit's preflight briefing and in-flight services, he would have been
provided with information that would have enabled him
to keep clear of the low level military traffic.
*
*
*
In central Queensland the captain of a Fokker Friendship preparing for a flight from Rockhampton to
Taroom, was advised that Low Jet Route 32 1 would be
active at approximately the time he was due to arrive
at Taroom. From a stud y of the LJR folder the captain
knew that military aircraft would avoid aerodromes
published in AIP AGA by at least five miles laterally or
4000 feet above aerodrome level vertically and that
Taroom was one such aerodrome. Furthermore, an
examination of the flight profile for LJR 321 indicated
that the F 1110 aircraft flying the route would remain
above 4000 AGL until it had passed Taroom.
Later, en route to Taroom, the Friendship was advised
b y Flight Service that the FI 11 had departed for LJR
321 and was estimating the commencement point of the
LJR at the same time as the Friendship was estimating
Taroom. This same information was being broadcast on
appropriate area frequencies for use by other aircraft.
From their pre-flight study ofLJR 32 1, together with the
updated information on the progress of the military
aircraft, the Friendship crew now saw that there was a
possibility of a conflic tion with the F 111 in the vicinity
of their destination. Accordingly, their descent and entry
into the circuit area was p lanned , using all available
information, so that the flight path of the Fokker
remained clear of the FI 11 at all times.
*
*
*
These two fictional examples illustrate, at opposite
ends of the scal e, the outcome of different pilot attitudes
to the problem of military low level jet operations. The
same information was readily available to each aircraft.
What made the d ifference was an a wareness of that service and the use of the information provided to ensure
the safe conduct of the flight concerned.
The question of how a pilot is supposed to know about,
let alone see a nd avoid, such traffic, is one which should
concern everyone who flies outside controlled airspace
whether for business or pleasure. There are no less than
200 promulgated low alti tude military training routes,
any of which may be active at any given time. Military
aircraft flying these routes usually follow the terrain between 500 and 1500 feet above ground level at speeds
of up to 540 knots. The aircraft normally operate singly,
with a n interval of approxima tel y · 15 minutes between
succeeding aircraft on the same route. Most of the
· page 6
aircraft operating the low level rou tes are camouflaged
and at such high speeds are ex tremely difficult to sight
against the terrain.
The military aircraft are all equipped with UHF bu t
none have VHF. FI I IC aircraft a re also equipped with
HF; but their crews do not normally use these frequencies
on terrain-following operations. M irage and Skyhawk
aircraft, which are equipped with UHF onl y, are out of
communication with ground stations for a large part of
the time and are incapable of direct communication with
civil aircraft, except when within range of UHF retransmit facilities at Coffs Harbour, Dubbo and Wagga.
Civil aircraft flyi ng below 10 OOO and 5 OOO feet are restricted to maximum airspeeds of 250 and 210 knots
respectively, to allow their pilots time to iden tify possible
traffic conflictions and avoid them. Bu t if the potential
hazard is a militar y aircraft approaching head-on a t
near-sonic speed, the rate of closure is such that a pilot
may have less than five seconds for each mile of separation to recognise the danger, decide what evasive action
to take, and carry it out. Even for an experienced pilot
this is very li ttle time.
L ocations of military routes are set out in the Low Jet
Route loose-leaf folder issued to all AIP and VFG
holders. Notification of the times during which these
routes are to be active a re advised by Class One Notam
at I.e ast twelve hours in advance of their intended use.
This information is readily a vailable at Airways Operations Units to enable pilots to ascertain whether any
active routes are likely to affect their intended fl ight.
Additionally, an in-flight traffic information service
provides updated infor mation to aircraft opera ting in the
vicinity of the low j et routes. Whenever practicable, a
broadcast of military low level jet activity is also made
on appropria te Flight Service frequencies before the jet
transits the area.
It is in the interests of pilots engaged in low level aerial
work operations, such as aerial agricultural operations,
pipe line patrols, and fishery surveys, to familiarise themselves with . the locations of any such routes in their
vicinity, and to check their nearest Airways Operations
Unit for advice ofLJR activity.
The fact that these routes exis t and are used should
not be any cause for alarm. Rather, forewarned is forearmed, and it is simply a matter of being p repa red for
what can be encountered. Some pilots are inclined to feel
that there is little need for concern b eca use the possibility
of conflict with military training flights is remote. The
truth is that a considerable a mount of military low level
air training is conducted constantly, year in and year out,
throughout Australia. An a ccident of this sort actu ally
occurred in England some m onths ago when an RAF
Phantom on a low level exercise collided with a Piper
Pawnee engaged in su per spreading. N eedless to say, the
crew of the Phantom, as well as the pilot of the P awnee,
were killed. F or these reasons, safety in flight demands
an unde~standing of how, where and when such flights
are m a d e . - - - - - - - - - - - - - - -- -..,,....~=·~
W~AT
CAN
Go
WRONG-
Will!
C a rrying a load of n ewspapers, a Cessn a 206 bein g flown
b y a commercial pilot arrived over its firs t p ort of call
on a daily delivery flight to several towns in northern
N ew South Wales.
T h e wea ther was fine and clear , and the p ilot assessed
the wind as a light easterly of abou t five knots. Positioning the aircraft in the circui t, he made an approach to
land on the sealed runway I 1. T he touchdown was
sm oo th a nd apparently norm al, bu t after running for
about 60 metres the aircraft began to veer to the right.
Applying left rudder, the p ilot t ried to s traigh ten up but,
though t he turn was only gradu al at fi rs t, his efforts were
ineffective. R ealising that if he delayed any further, the
aircraft would run off the runway, the p ilot opened the
throttle to go a round.
Immedia tely, the aircraft swung sha rp ly to the left
a nd, with all three wheels skidd in g on the bitumen,
h ead ed towards the opposite edge of the runway. T he
nose leg colla psed a nd the air craft slid sid eways a short
dista nce before stopping on the gravel verge of the runway, resting on the lower engine cowl, and the righ t main
wheel and wing tip as shown in the p icture.
*
*
*
At first sigh t, this accident would appear to be j us t one
more in sta n ce of a pilot losing d irectional control after
touchdown. But further inves tigation showed there was
more to it th an that.
With the seats removed, the C essna 206 is a very useful
small freighter , and the operator of this particular
a ircraft used it to carry newspapers on a d aily service.
Part of the freigh t sp ace was provided by removing the
right fron t sea t a nd placing the right ru dder p edals in
the forwa rd or stowed position. At the time of th e acciden t however, neither th e p ilot nor the operator knew ~'
that, even though the ru dder p edals were in the stowed
position, it was still possible to ob tain braking action by
exer ting p ressure on them.
Stowable right rudder p edals a re an optional fitting on
both the Cessna 206 and 207, and are installed in many
of these air craft in Austr alia . T hey are also an option in
the Cessna 185 a nd 210. O wner's manuals for aircraft of
these models manufactured before 1974 make no mention
of the fact th a t the brakes can still be operated with the
rudder ped als stowed. T he aircraft involved in this accident was an early model a nd the operator fou nd ou t a bout
the b rakes only as a result of the accid ent.
As the b und les of newspapers carried in the air craft
were n ot restrained against movement in any wa y, it is
likely that, d urin g flight, a bundle of n ewspapers slipped
forwar d un til it was resting against the stowed righ t rudder ped al. In this way, p ressure was a pplied to the right
brake, causing the air craft to veer to the r ight after touchdown . This in tu rn led d irectly to the need for the pilot
to ta ke corrective action, a nd the subseq uent loss of
control when he applied full power .
Both the Cessna 206 a nd 207 are wid ely used to carry
cargo, some of which is often loaded in to the space made
availa ble by rem oving the right-h and front seat. This
accident shows th e potential hazard of p lacing freight
near the stowed rudder pedals - it also emphasises
again the importance of properl y restrainin g such freight.
--
page7
�.
'
CltERokEES CollidE HEAd-oN
(Condensed from report issued by National Transportation Safety Board, U.S.A.)
While each was in cruising flight in Missouri, USA, a Cherokee Arrow and Cherokee Archer 11 collided
head-on at an altitude of 6000 feet. Both aircraft disintegrated and all five occupants - two in the Archer
and three in the Arrow were killed.
The Cherokee Archer had bee n hi red by its pilot from
U rb ana, Illinois, and was engaged on a private IFR
fligh t to Emp oria, Kans as. The Arrow was opera ting a
VFR cha rter fligh t from Salisbu ry, Missouri, to several
airports in the C hicago a rea. The weather was fin e and
clear, wi th a visi bility of at leas t 15 miles.
.
Kansas C ity C ontrol had radio and rada r contact with
the Archer, but no contact h ad been establish ed with the
Arrow during its climb from Salisbury to the collision
point.
While th e Arch er was under the control of the K ansas
C ity Centre, the controller twice advised the p ilot of
conflicting traffic, based upon transponder returns. T he
pages
first ad visory was given when the Archer was about 25
miles east of the M acon V OR, a nd t h e secon d when it
was a bout lO mi les east of Macon . T he pilot acknowledged both. No fur ther advisories were issued to the Archer
after it had passed the M acon V OR and ass umed a
south- wes terly heading.
At the time of th e accident the p ilot of a twin Cessn a,
which was at a n a ltitude of7600 feet, sighted black smoke
at his 10:30 position an d called K a nsas C ity Control,
'. , . I was glan cing tha t way, the sky was clear an d
all of a sud d en t here was just a black p uff I t's right
n ow a t abou t my ten thirty p osition - just like a flak
explosion fro m World War II'.
T he collision was also seen from the grou nd . A witness,
wh o was working in a field said, 'I had h eard the noise
of a plane. I th ough t i t was loud for one, so I looked
up - wha t seemed to be practically straight up when
1 was facing n orth. I saw two planes, one going east and
the other one going west. I said, " O h ... they are going
to cross," and by the ti me I had said it, they collided .
T here was a ball of fire, the bang of an explosion, and
a big puff of b lack smoke . Then the planes started falling.
O ne plane - that there was the most left of - spiralled
a nd came d own in slow motion close to the point of
impact. T he other one was blown in to thousands of pieces
and drifted wes t and sou th'. The witness did not see
ei ther aircraft ta ke evasive action.
The flight pa th of the Arrow is believed to have been a
straight line northeas t toward the Macon V OR, with the
aircraft in a climbing a tti tude to the collision point. When
the two aircr aft collided, the A rrow's heading was 042°.
T he Archer would h ave been flying at an assigned altitude
of 6000 feet on a n approximate headin g of24 l 0 •
Examina ti on of the recovered wreckage indicated that
both aircr aft were on a near head-on course at the
momen t of collisi on , the Archer striking the right side of
th e cockpit and ca bin of th e Arrow. As they collided, one
blad e of each propeller impacted the engine of the other
air cr aft . T h e p rop eller a nd engine of the Archer th en
p enetrated the forward right side of the Arrow, completely destroying i ts cockpit and cabin structure. At the
same time, the Archer 's fixed nose leg and left main
underca rriage penetrated t he leading edge of the Arrow's
right wing in the area of the fuel tank. Tyre scrapes were
fo und on the crus hed wing leading edge structure.
T he collision geome try indicated that the Arrow would
have been a bou t 11° to the left of the eye referen ce point
of the Archer and would have had a flight path angle of
about +4° in its clim b . Atthe same time the Archer would
have been a bou t 8° to th e right of the Arrow's eye reference
p oin t. N either aircraft would have been 'masked' by passen gers, structure, or interior furnishings .
I n a n effort to determine why each p ilot apparently
did not see a nd avoid the other aircraft, t h e Safety Board
considered the following factors:
• The near head-on a n gle at which both aircraft were
converging (abou t 161°) would have caused the
apparent size of each a ircraft to have been reduced
considerably. In this si tuation, the target's wing and
tail surfaces ar e no t discernible a:s only the head-on
view of th e aircr aft is presented to the viewer.
• The targets of each aircraft would not have been
masked by aircraft s tru cture and each target would
have remained essentially in the same location for
a t least the fi n al 60 seconds. Both targets would have
been very small when viewed from either pilot's position and wou ld have appeared in their peripheral
visi on with respect to the eye reference poin t. The
low ra te of cl osure would have permitted both pilots
to see th e oth er aircraft for at least 30 seconds before
the collision if each pilot was looking directly at the
target. According to the ground witn ess, however,
neither pilo t took evasive action.
• A pilot's ab ility to re-acquire a target after it is fi rst
sighted mus t also be considered. T ypically when a
ta rget is sigh ted , a pilot will m ake an initial judgement as to whe ther or not it is a threa t; if the target
is judged not to be a t hreat, the pilot will continue
scanning other portions of the sky. Generally, the
areas that are scanned routinely are to the front, less
frequently the sides, and above and below. When a
target is small, it is often difficult to re-acquire it in
foveal vision during subsequent scans, unless it is
conspicious. Though both aircraft were wnite, they
would not have been conspicuous until they were
relatively close to each other - in this case about
30 seconds before impact. The Archer would have
appeared as a black dot against the sky and the
Arrow as a black dot against the terrain or slightly
above the horizon. Only when the two aircraft got
close to each other would the almost head-on
relationship have become apparent.
If the pilot of the Archer did see the Arrow, he might
ot have recognised it was on a collision course. H e had
eceived some training on the 'fixity of target' principle
which states that, when an airborne target remains in a
xed position in the windscreen, a collision course is
indicated. To prevent the collision, the course or al titude
of one of the aircraft must be adjusted. I mplied in this
principle, however, is the pilot's ability to discern a zero
rate of change in the other aircraft's heading or speed,
or both. T he size of the target, depending upQn the rate
of closure, may change drastically in the last few seconds
before the collision. In this case the pilot had limited
flight time (310 hours in the last six a n d a half years and
only 60 hours in the last three), and his inexpe rience in
IFR operations, as well as the two previous traffic
advisories, could have led him to believe he would be
provided with further advisories before other aircraft
might be expected to become visible.
T he pilot of the Archer had only one passenger, who
was located in the other front seat, but as she was not
a pilot, she would not be expected to mainta in a level
of vigilance comparable to that of the pilot. Opera ting
as he was on an IF R clearance, the p ilot might have
relaxed his vigilance and might not have maintained
an adequate outside scan. Any distractions such as referring to maps, explaining the operation of the aircraft to
his passenger, or sightseeing, would have further
compromised his vigilance.
The pilot of the Arrow had departed Salisbury en
route to a number of locations in M issouri and Illinois.
From the available information, his flight plannin g was
minimal before take-off. Based on the pilot's experience
and his familiari ty with the area, the Safety Board
assumed that he would have climbed to the Macon VO R
and, from there, set a course to his first destination.
T he Safety Board believes that, more tha n any other
factor, inadequ ate vigilance on the part of both pilots
appears to have been the predominant cause of this
collision. T he relatively low closure rates, the location of
each target in each aircraft wind screen, and the six or
more miles visibility should have allowed each pil ot
ample opportunity to see the other a ircraft in time to
prevent the collision
T he accident is an example of the limitations of the
see-a nd-avoid con cept. I t serves as a reminder to all
pilots to maintain constant vig ilance while flying in visual
flight conditions - regardless of the type of flight plan
under wh ich they are operating- to request traffic advisories, and to ensure that their transponder is on a nd
functioning.
~
page 9
�Instrument panel of the Friendship,
showing the undercarriage selector
handle in the raised position. The knob
has been rotated 60 degrees to the
left, allowing the locking lever which
prevents inadvertent re traction to be
over-ridden.
During flight, the crew of a Fokker Friendship noticed
a difference in the readings of the captain's and the first
officer's rate of climb indicators. Suspecting the fault l ay
in the instru men t on the left hand instrument panel, the
captain ente red the unserviceability in the aircraft's trip
record.
After the aircraft had landed, arrangements were
made for an LAME to change the suspect instrument
during the 'turn around' inspection. To replace th.is
instrumen t, it is first n ecessary to l ower the mam
instrument p anel by removing the knob from the undercarriage control handle, releasing four s~rew.s a t. the top
of the panel a nd swinging the panel , which 1s hmged at
the bottom , rearwards.
The undercarriage con trol h andle in the Friendship is
mounted on the front pressure bulkhead a nd extends into
the cockpit through a slot in the main instrument p an el.
The h andle consists of upper a nd lower h alves connected
by the control handle knob, a nd th e combined handle
normally funct!ons as a single unit. The upper halfof the
h a ndle controls the re traction a nd extension of the undercarriage, while the lower half is locked by means. of a
pawl when the aircraft is on the ground, to prevent madvertent U P selection. When the aircraft is airborne a nd
the left main undercarriage leg is fully extended, a microswitch on the shock strut completes a circuit to a solenoid
which is then en ergised and the locking pawl is disengaged. The undercarriage h andle, complete with the
locking lever, can then be raised. In an emergency, the
function of the locking lever can be overridden by 'spli ttin g' th e undercarriage control handle. This is done by
pullin g the disengage trigger on the control ha nd le kn ob
and rotating the knob through a b ou t 60 degrees. The
upper half of the handle can then be moved inde~en
den tly of the locked lower half, a nd the undercarriage
raised .
The undercarriage control knob is attached to the
lever b y a screw underneath the knob. Attempt~n g to
release this screw in th is case, the LAME found it was
p articularly tight and that he needed to apply considerable upward force to the screwdriver to ensure it en~aged
properly in the slotted head of the sere~. H e ha~ his left
ha nd over the top of the knob to steady 1t and while i:>ushing firmly on the screwdriver, it is ap parent th a t he inadvertently operated the disengage trigger. With t~e trigger
disengaged, slight misal ignment of th e screwdnver force
was all that was required to rotate the knob to the release
position. The handle split, a nd the operating lever was
pushed upwards . The undercarriage retracted and, as th e
aircraft fell to the ground , the engineer was t hrown forward, striking his head on the instrument panel a nd control pedestal, and inju ring his back. The fuselage and left
wing of th e Friendship were extensively damaged.
*
*
*
Subsequent inves tigation revealed that, before
attempting to remove the main instrumen t panel, the. engineer had not taken t he basic safety precaut10ns
specified in the operator's maintenance manual. The first
two steps in the removal sequ ence a re to ensure that t~e
aircraft's electrical power is off, and that the pneu matic
system is completely discharged.
.
Ensuring th at electrical power is off guards agams~ an
inadverten t U P selection of the complete undercarriage
control h andle, because th e locking pawl is engaged wi th
power off. Bu t regardless of whether power is on or off,
the undercarriage selector handle can still be split by
rotating the knob and the upper half raised, thus permitting the undercarriage to be retracted by pneumatic pressure if the system is not discharged. On this occasion,
residual press ure in the main pneumatic system when the
a ircraft was shut down was 18 600 kPa, sufficient to fully
r etract both main undercarriage assemblies and partly
retract the nose wheel.
Short cuts of any sort in aviation are potentially disastrous. T he safety procedures to be adop ted when
removing the instrument panel were laid down in the
company's maintenance manual and it is clear that, if
they had been followed in this case, the incident would
have been avoid ed.
EyEsiqHr is pREcious
At a recent safety conference, a n eye specialist described
a h azard that could affect each of us and our families.
That hazard is the catalyst or hardener added to
fibreglass resin before the resin is applied . The eye
specialist stated that a drop of this catalyst in the eye will
progressively destroy the tissue of the eye and result in
b lindness. This will occur even though an attempt is
made to wash the catalyst from the eye. Furthermore,
once the ch emical has started to destroy the eye, there
is no known way of stopping the destruction or repairing
the damage.
The sp ecific toxic agent involved is methyl-ethyl-ketone
peroxide (MEKP). In laboratory tests, MEKP in solutions of varyi ng concentrations was found to cause eye
problems ranging from 'irritation' to 'severe damage'. T he
maxi mu m concentration producing no appreciable irritati on was a solu tion con taining only 0 .6% MEKP.
Material pu blished on the subject indicates that washing
a n affected eye within four seconds after contamination
preven ted injuries in all cases, but no known chemical
ne u tralizer has been discovered.Suggested p recautions for
catalyst users a re eye-protective spectacles and the
immediate availability of a source of bland fluid such as
water for thorough washing of ocular tissues.
One disastrous experience was described. Wh ile
fib reglassing a chair at home, a victim had both eyes contaminated by MEKP. T hough he mad e an effort to wash
his eyes out, several minutes apparently elapsed before he
found water. T he sight of one eye was lost immediately,
the other was lost gradually over a period of about eight
years. Its deterioration was described as resembling that
resulting from mustard gas burns during World War I.
This fibreglass resin danger was previousl y unknown to
those attending the conference, though many had used
fibreglass resin at work or at home. The hazard may be
unknown to readers also - and to wives a nd children who
may use a similar kind ofresin and catalyst when working
with fibreglass or hardeners used in liquid casting plastic.
So before using a ny of these catalysts, check their
chemical composition a nd take appropriate precautions.
The cost of a pair of safety goggles is a very small price
to pay for t he protection of eyesight.-- - - ""=......-~,,.---
With acknowledgement to American A irlines.
page 11
page 10
�l
I
I
A t Darwin, two pilots approved for low-level aerobatics
had arranged to conduct some practice sequences. The
wea ther was fi ne and warm and, about mid-morning, the
pil ots carried ou t a dail y inspection of the aircraft they
would be using, a single-seat Pi tts Special. T hey had
obtained a clearance to operate in the ' aerobatic zone',
which is over the airport at the south -eastern end of the
disused runway 13/3 1. T he upper height limit for the
exercise was 3000 feet. One of the pilots, the more
experienced of the two, takes up the story:
I had asked the other pilot to fly first, so I could observe his manoeuvres from the ground. This flight lasted 27 minutes and was
uneventful. We then changed over and after taking off, I climbed to
3000 feet to practise a four-minute sequence of free-style aerobatics.
I began with an inverted, power on, left flat spin. After six turns, I
recovered into a vertical dive then, when the airspeed had built-up,
pulled up into a vertical climb and carried out an eight-point hesitation roll to the right. This was followed by a stall turn, then in quick
succession, an outside 360 degree snap roll to the left on the vertical
down line, which I initiated at 80 knots using right rudder, and an
inside 360 degree snap roll to the right, again using right rudder,
recovering at about 1200 feet.
At this stage I discontinued the sequence and climbed back to
3000 feet to start again. Once more I entered an inverted, power-on
flat spin to the left, followed by the same manoeuvres. However,
when I applied rapid , firm right rudder, back stick and right aileron
to initiate the inside snap on the down line, the aircraft began to
rotate cleanly, but sudden ly my right leg plunged to its full reach
without resistance.
Instantly, I realised the rudder cable had given way. Believing at
first the cable itself had parted and fearing the right cable would be
pulled beyond my reach, I instinctively reached forward and grabbed
the loose end before applying left rudder to recover. By this time
the aircraft had rotated just over 360 degrees and I pulled out of
the dive between 1OOO and 1200 feet using elevator and aileron control. I took a moment to settle down, and then called Darwin Tower
to tell them of my predicament. They alerted the emergency services
and cleared me to land on runway 11. I had taken up a northerly
heading across the airport .and, while continuing on a wide left circuit,
I had wrapped the loose rudder cable around my wrist and hand .
By pulling on the cable, I was able to obtain some measure of right
rudder control.
The right rudder pedal, with its toe brake, had shot forward with
such force when the cab le let go that it had dented the firewall and
was now beyond my reach. So I knew that on landing, I would have
no directional control once the slipstream effect on the rudder had
diminished . Because of its tail-wheel undercarriage and very short
fuselage, the Pitts requires maximum concentration and constant ap·
plication of brakes to keep straight after touchdown, irrespective of
the wind direction. It was unfortunate that the prevai ling weather conditions would compound my problems, as the wind was gusting. I
decided to carry out a powered approach at minimum speed.
•
On final approach, I was able to manipulate sufficient right rudder to maintain a constant heading in a three-point attitude. About
five feet over the threshold , I closed the throttle complete ly and the
aircraft settled on to the runway on three points at about 60 knots.
The aircraft began to swing to the left, so I corrected by pulling on
the right rudder cable. I maintained directional control initially but
then the airc raft began to swing to the left again. Though gradual
at first, the turn rap idly tightened into a ground loop and, despite
full right rudder deflection I was powerless to correct it - obviously
slipstream effect had been lost. I could hear the right tyre screeching,
then I felt the tail lift and saw the right lower wing scraping the bitumen. As the tail rose higher, the propeller struck the ground and
the aircraft skidded to a stop on its nose at about right angles to
the runway. I climbed from the aircraft and within seconds, the
crash crew was on the scene !
*
*
*
Inspection of the aircraft disclosed that the right rud der cable had become detached from the rudder pedal.
T he 3.2 mm (1/s inch) diameter cable had pulled through
a copper N icopress sleeve used to form an eye where the
cable attaches to the rudder pedal (see photograph) .
Both rudder cables were removed from the aircraft,
which had flown only 65 hours since new, for more
detailed examination. The cables have similar eye fittings
at each end and these were measured and compared with
other sample end splices. I t was found that, while the
copper sleeves used to form the eyes were the correct type
for 3.2 mm (1/s inch) cable, all four end splices had been
formed with a pressing tool appropriate to a cable diameter of 4 mm (5 / 32 inch). Thus the sleeve had not been
properly compressed and the resulting clamping action
was insufficien t to provide a splice of adequate strength.
D uring a series of laboratory tests, the rear end of the
left rudder cable pulled through the sleeve when a load
of 280 kg was applied. It appeared from marks on the
fittings that the splice which failed in flight would h ave
been significantly less effective than the one which failed
on test. A correctl y pressed sleeve withstood a load of
1090 kg without any sign of slipping.
As a resul t of the inves tigation in to this accident, an
Airworthiness Directive was issued requiring that all
cable splices in Australian-registered Pitts Specials be
inspected before further flight. The airworthiness authority in the United States also issued an Airworthiness
Directive requiring inspection of the Nicopress sleeves on
Pitts' rudder control cables.
*
*
*
The pilot of the Pi tts holds a private licence wi th
approval for low-level aerobatics, and at the time of the
acciden t had flown about 400 hours in the aircraft type.
He is to be commended for his handling of the aircraft
in a serious emergency. He correctly assessed a nasty
situation and by quick improvisation was able to obtain
some degree of rudder control. H is presence of mind
undoub ted ly saved a valuable aircraft from more serious
damage, if not complete destruction.
Intact end-splice on rudder cable removed from the Pitts after the
accident. The copper sleeve has been re-pressed in the centre
groove with the correct sized tool, to show the additional compression
required for a satisfactory splice.
page 12
page 13
�·'
YOU THREW
AWAY THE
RIPCORD?'
By David Townsend
With acknowledgment and thanks to 'Australi.an Gliding'.)
The morning foretold another scorching day.
It is th e first d ay of the New South Wales Sports Class
and Two-seater Gliding Championships at Leeton in the
wheat-growing plains of south-eastern Australia and I
am to fl y my club's new Pilatus B4 15-metre sailplane.
I am nervous at the prospect of my first competition: my
stomach won't settle down, and the heat is no help.
It will have to be endured, and the met. briefing is
that thermals will not·start until the ground temperature
gets to 40 degrees C. A blanket of high cirrus cloud is
moving in from the west; maybe the ground won't get
hot enough to produce strong lift. The task-setters consider the pros a nd cons and ann ounce a 15 1 kilometre
triangle for single-seaters wi th the distinctive wheat silos
at Mirrool a nd Garoolgan as the turning points.
A coupl e of hours are spent checking th e glider and
its equipment, stowin g wa ter bottles so necessary in case
of an ou tlanding in some remote area. I decide to remove
the seat cushion to give my head a little more clearance
from the' canopy. I find I can nestle into the cockpit very
comfortably in the 'Slimpak' parachute.
.
t
'
page 14
At last the thermals begin, weakly, but enough for the
ground marshal to call in the tugs. Soon, sweating in the
oven-like cockpit and spitting out the gri tty red dust
blown in by the tug's prop-wash, I a m whisked aloft but
towards the irrigated farm lands.
Damn! Why does he take me so far downwind over
these soggy ricefields? There's no lift around here. I
release at 2000 feet and head back for the field but the
only lift I can find is within a kilometre of the starting
gate where thermalling is prohibited. I land, cursing a nd
calling for a relight.
' Calm down, take it easy', says my wife as she helps
me retighten the chute and s traps me firml y back in the
cockpit. This time the traffic is easier and I am dropped
close to a thermal to which it seems every glider in the
southern hemisphere is heading. It fizzles out at abou t
4000 feet and the occupancy rate at the top is very high.
I am not happy hanging around in that gaggle even
though it wou ld seem to be better to delay starting until
conditi ons stren gthen.
I ease carefull y out of the crowded thermal and turn
for the gate, which is marked by one of the runways. I
cross at slightl y under 3000 feet, get the radio call, 'Good
start Whiskey Quebec Mike', and in the absence of any
signs of lift, proceed at a cautious and height-conserving
45 knots on course for Mirrool.
This progress continues in a stately, but downward direction, until with less than 1800 feet, I must decide
whether to blunder on hopefully or to scrape back to the
airstrip. I creep over some rising ground and the va rios
tell me we are in zero sink. I make some exploratory turns
and graduall y work my way in to a weak thermal that
straggles to 3500 feet.
Gradually things improve and I find strong lift that
ca rries me to 9500 feet. At this height the view is mag nificent. I can see the roads leading to Mirrool and the railway lin e that runs to the second turn point, Garoolgan!
I marvel at th e yellow of ripe wheat, the bleached stubble
and the dark, purple look of the wooded areas.
Exhilarated , I could Aoa t here all day; but I remi nd
myself t hat the race is to th e swiftest. I p ush the stick
forward and the B4's nose goes down until the ASI reads
90 knots. I am impressed by the way we travel over the
ground, even though I seem to be looking down at it between m y feet. I pull the stick back to slow down while
passi ng through rising a ir, but only bother to circle when
the lift is strong . The only other gliders l see are a Blanik
a nd a Ka6.
This is what glider pilots dream about! I laugh and
sing with the joy ofit. Other pilots are feeling the same
by the excited radio chatter a nd I reAect that the twoseaters are particularly garrulous.
It seems incredible, but I am a lmost over Mirrool silo
still with more than 9000 feet on the clock! I fumble for
the Ins tamatic camera a nd prepare to ma ke a steep turn.
O ver we go - keep the wingtip in the viewfi nder where' s that silo? Over further; with this and the unaccus tomcd left hand on the stick a horrendous sideslip develops. I think I get the silo in the picture but I am practically right over it. Better go back and have another go.
I turn slowly and cautiously away from the silo looking
carefully for other gliders. But reckoning on being further
out than they would be I turn again to photograph the
silo looking back a long the direction in which I had
come. Can't see anyone. I take two shots a nd hope they
will do - I want to get away from here.
I check my height - still over 9000 feet. Speed? Say
50 knots till I sort out the heading to Garoolgan. There
we are - 271° magnetic. Now wh ere's that map?
Reaching for it under my right elbow I take a look
ou tside- heading s traight for me is the slim outline of
the vec-tailed Saito! It is slightl y hig her than I am, but
obviously close. Instinctively I push the stfck forward to
go under it. At the same time as my left hand gets to
the airbra ke lever, _the white form blurs overhead.
There is a bump - hollow and metallic. ' It's OK',
my brain reports instantly, 'only a glan cing blow on top
of the tail'.
Perhaps a second of deathly quiet passes - then the
B4 flips end over end and I am upside down in a violent,
whirling spin. My arms arc flung against the sides of the
cockpit; I can't ge t my breath. I s tru ggle to get my hands
on the stick; it's jammed hard forward. The earth whirls
crazily below.
I know I mustjump. Mechanically, my left hand finds
the canopy rel ease. The canopy lifts and disappears in
an instant with a sound like a riAe shot. Turbulent air
bias ts nois ii y at me. It is pleasantly cool er.
Somewhere inside me, as I fumble with the harness
release, a calm, textbook sort of voice in tones: ' It is advisable to abandon the glider with your hand on the rip-.
cord '. Still whirling, I manage to get my right hand on
it, low on my left side. My left hand pulls the harness
release. Horror upon horror; I fall straight out of the
cockpit!
Face downward I plummet towards the brown earth.
I sense that the B4 has righted itself and is above and
behind me, well clear. Frantically, I pull the ripcord. It
offers no resistance; I continue to hurtle downwards, staring at the ground, brea thless with shock.
This ghastly hiatus ends with a violent jerk, I a m vertical, dazed, hanging in those wonderful s traps. Above
me is a smooth white , yellow and black canopy. There
is no sound, I am alive and likel y to remain so. Suddenly,
life is precious .
I hazard a downward glance and my stupor is sh attered by t he appearan ce of the Saito hurtling into. my
field of view, perh aps 1OOO feet below, in a spiral dive
with the outer section of one wing crumpled.
I know that John C hurch is in the cockpit. 'John, get
out. Let me see you ', I scream to the empty air. A second
later I see th e canopy li ft away. John's form steps out
as a man might jump into a swimming pool. He pulls
the ripcord, the 'Slimpak' opens a nd his canopy b lossoms. I relax.
Then my abandoned glider appears below. It is the
right way up in a flat spin. A whirling white object near
it puzzles me for a moment. Then I understand. The object is the complete tail section - fin and rudder,
horizontal stabiliser and elevator. The whole thing must
have been sheared off in the collision.
Now I can see both the B4 and the Saito spinning
earthwards, together. John seems to be descending faster
than me. I notice that one of my shoes is missing and
the other is hanging preca riously from m y toes . Gingerly,
and sicken ed by the distance between the shoe a nd the
ground, I lean forward in the straps, get it back on my
foot a nd retie the lace.
John is now much lower th an me. He is heavier than
I am. Maybe I am not descend ing at all. I look up. A
page 15
�large dark cloud looms around the bright canopy. Maybe
I am in some gigantic thermal and I am going to be
sucked up into that black cloud.
Frightened again, I tug at the lines, trying to collapse
part of the chute. It doesn't seem to make any difference.
The thick cords hurt my fingers and I give up. The
ground looks just as far away. The few farm houses are
still mere dots.
The fear vanishes and I am filled with a marvellous
well-being. I have never felt so peaceful, so happ y. The
view is magnificent. Time seems to stand still while I am
suspended in the huge bowl of sky. It is utterly, utterly
quiet.
I watch the Saito, then the B4 thud into a ploughed
paddock, not far from each other. They send up brief
spurts of reddish dust, then are still. Suddenl y I am
flooded with wild dismay as I realise two fine aircraft are
now wrecks and that one of them was, until a few minutes
ago, the newest and proudest possession of my club.
John is near the ground. I watch as he hits. His body
seems to crumple; the canopy collapses beside him.
Within seconds I see him rolling it into a bundle. Holding
it in his arms, he strides vigorously towards a nearby
farmhouse. I wonder how I will fare.
I study the ground. At least I can see that it is closer.
I am descending, drifting in the light wind away from
the paddock where the gliders lie, away from open paddocks a nd over low, wooded hills. I pull mightily at the
right line and drift slowly back towards open ground.
I sink into a bank of hot, dry air. I won't be long now.
I am su rprised to realise that I am cheerfully resigned
to at least a broken leg.
I am going to land in a large fallow paddock. There
are three or four trees in it and I am over the larges t,
an old spreading eucalypt. I pull franticall y at the lines,
first one side then the other. Nothing seems to happen.
The earth is rushing up at me. I can smell the dry
ground. The breeze slides me well clear of the tree. The
calm textbook voice is back: 'Remain with your back to
the wind, feet together, knees slightl y bent and roll as
you hit'.
The impact is astonishingly hard. I lie on one side,
winded, unable to breath. Gradually air returns to my
lungs; I test arms and legs. I sit up and pain shoots along
my spine, my chest feels as if it is bound with steel
straps.
I roll the chute as best I can a nd stumble towards the
distant farmhouse. Progress is slow and not without discomfort. Every few paces I have to stop and pick thistles
from my right foo t, protected only by a thin sock.
I become conscious of a car speeding towards me. It
slides to a halt in a cloud of dust and the farm owner,
his son and John Church step out.
Suddenly John and I are shaking hands and desperately glad to be doing so. While we wait for our wives
and crew to drive from Leeton, John and I talk in the
friendly farmhouse kitchen. To my surprise, I learn that
John was formerly a parachute instructor in the Australian Army. A veteran of about 500 drops, this is his
first 'emergency'.
Later, back at the airstrip, I am able to laugh, if wryly,
at the number of old hands who, after expressing their
pleasure at seeing John and me alive and well, ask to
see the ripcord .
'I dropped it, I guess', I say to one, recalling my terror
the moment before the canopy filled. ,
'What, you mean you threw away the ripcord?' he
says, shocked. 'You're supposed to keep it for repacking.
T hey cost money you know.'
In Retrospect:
For glider pilots I would sum up advice about
parachutes this way:
• Wear one.
• Know how to use it.
I think the only time they are not necessary is in twoseaters on local soaring and training flights. They should
always be used in single-seaters. Indeed most cockpits are
built so that a parachute forms a handy part of the seating. Except perhaps for some older gliders with upright
seating, it seems to me that the 'Slimpak' type is the most
a daptable.
The wrecked Pilatus ~e~) and Saito (right) as they came to rest in open country after the collision. Note the entire tail section of the Pilatus has
been torn away.
page 16
j
'
Pilots converting to their first single-seater are most
likely to be about to don a parachu te for the first time.
T hey should be thoroughly briefed by an instructor and
separately from the briefing on the aircraft. Someone
conversan t with the particular chute should check that
it is donned proper! y. (Yes, glider pilots have been seen
climbing in to their aircraft, wearing their chutes upside
down!)
The harness should be drawn up tight while standing.
You should end up slightly crouched and find walking
a little awkward. Spend some time in the cockpit ensuring comfort. Get out again if necessary, until the harness
is adjusted correctl y. A too tight strap loosened in flight
could be as disastrous as not wearing a chute at all.
Films are available on the use of parachutes, so why
not arrange a showing at your club? There are man y experienced parachutists among the skydivers, who would
be happy to speak on the subject and demonstrate proper
care and handling.
Ensure that everyone who wears a parachute knows
how to inspect it. Check the packing slip and make sure
it is repacked by the due date.
Carefully open the flap covering the pins. They must
be pushed fully in to the studs, and the piece of red thread
and lead seal tied around one pin and stud must be
intact. The ripcord should be tucked fully into its
pocket.
Keep the chute clean and dry. Never put it on the
ground. Keep it in a zippered carrying bag. This way
you can use it as a temporary wing-tip weight.
Thinking back, I don't believe the remote voice inside
me oITered the best advice. I discussed the jump with fellow club member Jack Stevens, an experienced pilot and
a renowned authority on parachutes. (Incidentally, Jack
packed the chute I used and for this alone, I hold him
forever blessed.)
Jack believes the pilot's hand should not be on the ripcord before bailing out. This is because of the risk of pulling it instead of the seat harness release or of deploying
the chute when not clear of the aircraft.
Both John and I suffered cuts and bruises to the shins
caused by dragging against the instrument panels. If
possible, departing pilots should draw their knees
towards their chests before releasing the seat harness.
This may be difficult in some gliders. At least make sure
there are no dangerous projections such as oxygen
plumbing under the panel or attached to the cockpit
sides.
J ack says you should try to land facing the wind rather
than turning one's back on it - in strong conditions the
canopy could drag you along the ground. When face
down it may not be possible to collapse the canopy and
the slowest ground speed gives the softest landing (the
same as a glider).
The pain in my spi ne disappeared in a day or two.
Soreness in my chest and upper back persisted for five
or six weeks. T his was due not to the hard landing, as
I had thought, but to the shock from the canopy opening
when I was face down. Bruising on m y shoulders and
inner thighs testified to that.
Just one final piece of ad vice: if you d o have to bailout, do not hang on to the ripcord after you've pulled
it. I t could tangle with the canopy a nd cause a malfunction - so get rid of it! - - - - -- - - - -..,,...~==--~
Its Good Advice For Us Too!
The following 'Pilot Contribution' appeared
recently in the United States gliding magazine 'Soaring'. We reproduce it with acknowledgement,
believing that Australian pilots - both power and
glider - can learn something from their American
colleague's experience:
Keep your eye on that hole!
I was making a thermalling ascent on the desert side of
the San Gabriel Mountains in California. To my
surprise, lift continued past cloudbase (9000 feet AMSL) ,
increasing to 800 fpm on the windward face of a building
cumulus. C loud CO\'er was broken with plenty of safe exit
holes and it looked like a rare opportunity. In no time
at all I was climbing right up the cloud's face at 14000
feet AMSL and enjoying the spectacular panorama. In
my eagerness to sa,·our this experience and record it on
camera, I neglected to check the undercast for 10 to
15 minutes - no more. Picture 1 shows the size of the
holes on the way up. About 10 minutes later picture 2
(my last on that day) alerted me, and to my dismay the
holes below were closed except for a small one that I just
squeaked through .
I sure learned a thing about weather from that and
wanted to share this pictorial proof of how fast old
Mother Nature can do her thing!
•;;--
page 17
�.
'
View looking in take-off direction as
seen from a position close to where
aircraft became airborne. The tree the
aircraft struck is indicated. The
wreckage is in the centre background
of the picture.
Tl-IE WRONG SidE of
Tl-IE POWER CURVE
aircraft should have been able to continue climbing away
and a void other o bstructions which were lower a nd more
distant from the point of lift-off.
The sounding of the s tall-warning horn a nd the
aircraft's low height over the buildings beyond the end
of the strip had alerted the pilot to the aircraft's subnormal rate of climb. It was at this point tha t a nother fac tor
in the accident sequence was introd uced: th e pilot
lowered the fla ps to the ' h alf position believing that in
so doing he would improve the climb performance of the
aircraft. In fact, the onl y result of lowering flap from the
normal take-off setting of lO degrees to the ' hair position
would h ave been to reduce the lift-drag ratio. For a n
The pilot of a Cessna 177 was departing from a country
airs trip with two passengers on board. H e carried out his
pre-take-off checks, selected one s tage of flap a nd after
lining-up at the threshold, applied full power. The grass
strip was approximately 600 metres long with a downslope of about one degree, the wind conditions light and
variable.
Before commencing the take-off, the pilot h ad noticed
several fl ocks of birds in the vicinity of the strip and halfway through the take-off run, h e caught sight of two
galahs on the g round in front of the aircraft. The pilot
said tha t he then reduced power by about a quarterthrottle, before veering to the righ t to avoid the birds.
This evasive manoeuvre was successful a nd h e steered the
Cessna back on to its ta ke-off path.
Believing t ha t he ·was now committed , the p ilot persevered with the take-off, and the aircraft became airborne just before reaching the far end of the s trip, with
the stall-warning sounding for a short period. The Cessna
climbed slowly, narrowl y clearing a h ouse beyond the
end of the strip, and the pilot became concerned at the
apparen t lack of performance. In the hope of improving
th e ra te of climb, he increased th e fl ap setting to a bou t
th e 'h air position. At this point he also noticed for the
first time that he had forgot ten to re-open the throttle
after veering to avoid the birds. H e im med iately applied
full powe r .
page 18
The aircraft held height for a short while but then
b egan to sink and the pilot was unable to prevent the
starboard wing hitting the top of a gum-tree. Losing
speed rapidly, the aircraft fell to the ground, striking it
first on the nose a nd port wing, and came to rest badly
damaged. Though all three occupa nts suffered injuries,
they were a ble to climb out unaided.
*
*
*
Subsequent investigation disclosed that there were no
d efects in the aircraft or i ts systems th at could have contributed to the accident a nd that the aircraft's gross
weight a nd centre of gravity were within limi ts. Witnesses
said th a t the aircraft had become airborne at a point consistent with previous operations by this a ircraft. It was
calculated that in the existing meteorological conditions,
the ta ke-off dista nce avai lable was a bou t 45 metres less
than the distance required to reach a height of 50 feet
as specified in the ta ke-off weight ch art in the app roved
flight manual for the aircraft.
Although it would a ppear that the throttle redu ction
was a major factor in the circu ms tances which led to this
accident, it was probably not the only one. A positi ve
climb angle of only a bou t two degr ees was all that was
needed for the a ircraft to have cleared the tree it finally
hit. As the aircraft h ad become airborne within the
len gth of the strip and had already cleared trees slightly
higher than th e one it s tru ck, it would seem tha t the
A
CLosE
CALL!
From a recent incident report:
Flying a Piper C h erokee, I d eparted from Bankstown at
11 50 hours on a n IFR flight to Canberra. The airways
clearance was '29 Marulan departure, cruise 6000' a nd
th ere was a n initial heigh t res triction of 3000 feet.
On reaching 6000 fee t I noticed that the cloud base
was a bo ut 5800 feet on a rea QNH a nd tha t the aircraft
was in a nd out of broken stra to-cum u lus.
aircraft in t his situation, the only way in which an
improvement in climb p erformance could have been
achieved would have been to increase speed or, if this
were not possible, to use additional power.
The pilot felt the aircraft begin to mush and lose height
and at this stage he claims he did increase the engine
power. But of course it was too la te and any possible advantage was outweighed by the d rag associated with the
half-flap setting a nd the low a irspeed situa tion. In other
words, the airc raft was well on to ' the back side of the
power curve', where th e power required to recover
exceeded the power availa ble.
The pilot in the right h a nd seat happened to be watching for a visual fix when he sudd enl y saw a glider emerging from cloud only 500 metres a head and a bove our
aircraft. There was no question of a collision if both
aircraft continued on their es tabl ished paths and within
a few seconds, m y aircr aft passed less than 50 feet benea th
the glider.
Apart from being a ver y unnerving a nd dangerous experience, I am concerned a t the irresponsibility of the
glider pilot. The incident highlights the following points:
• The glider was non-VMC in con trolled a irspace.
• Had I been alone on instrumen ts I would not have
seen the glider if evasive action had been necessary.
• If evasive action h ad been necessary, a sudden
change of attitud e into cloud could have meant loss
of con trol of the aircraft, thus further j eopardising
air craft a nd crew.
W e all need to be reminded of our responsibilities from
time to time - both to ourselves a nd to others - and
I thin k gliding clubs, especially around dense traffic a reas
like Syd ney a nd Bankstown, need regula r reminders. No
ma tter how tempting it is to go up with a thermal to
get home, there is almos t certainl y somebody else in that
cloud on top of the the rmal!
I hope this experien ce will a lert all pilots to the potential hazards of bending the rules.
-......_
page 19
�...
·,
( Photograph courtesy of Carpentaria Newspapers P t y . Ltd. )
The paper on which this article is based was originally. prepared as a result of questions raised at a
general aviation symposium attended by more than 100 pilots at Longreach, Queensland_. Though mainly
concerned with the problem of dust devils in that State, the comments and observations made have
application to inland Australia generally.
classed as 'frightening'. Voluntary weather observers eviIn inland Queensland the occurrence of whirlwinds or
den tly have much the same attitude, for though local
'dust d evils' as they have come to be known, is so frequent
people will speak of seeing at least ten dust devils in the
that local residents r egard them as part of the summer
course of an hour, or even at one time, this is not borne
'scenery'. Pilo ts operating in these areas encounter dust
out by reports from weather stations in western
devils so often that they do not usually bother to report
Queensland.
them, even when their in-flight experience could be
page 20
Pilots were asked to recount some of their more hazardous moments while flying in dust devil conditions and
the following accounts give some indication of their effect
on light aircraft. Though most pilots were adamant that
dust devils are not really a dangerous phenomenon, their
experience shows the need to develop safe techniques for
operating in dust devil conditions - both in-flight and
during take-offs and landings:
• A pilot was flying a Cessna 172 in the Cunnamulla
area at 10 OOO fee t in cloudless conditions. T he surface
temperatu re was above 38 degrees C and the wind
light and variable. No dust devils were visible at the
cruising level, but many could be seen below. The
aircraft was heavily loaded, with the pilot's wife and
three children as passengers. The pilot believes he
fle w into the invisible top of a cauliflowering dust
devil: ' In spite of full corrective control and full
power,' he r ecounts, 'the aircraft rolled inverted and
was fl own out underneath. I could not climb any
higher a nd was for ced to descend to maintain control'.
• At Nanda an a ircraft was landing into a gusty wind
of 20 to 30 knots . Small number s of scattered dus t
devils were visible and the surface temperature was
a bout 38 degrees C . 'At the last moment,' the pilot
relates, ' a dus t devil several hundred feet high crossed the landing path, slewing the aircraft first one
way then the o ther, and rolling it on to each main
landing wheel alternately. The whirlwind was one
of a group of three, a nd was invisible until it moved
on to a n un grassed area and picked up d ust. A t one
point the a ircraft was lifted clear of the ground at
or just below stalling speed - very unpleasant!'
• At Richmond, a Cessna 150 was taking off in almost
calm conditions. T he temperature was 4 1 degrees C
a nd the sky was cloudless. At a height of about 100
feet it encoun tered a whirlwind. (The pilot believes
this was in the process of forming a t the time - it
was not visible as he was taking off, but it later became a very large dust devil. ) The pilot's first indication of the encounter was a very sudden gain of about
200 feet of height. But then the upward motion stopped so suddenl y that the pilot was flung against the
restrain t of his seat belt and bumped his head against
the cabin roof. At the same time the airspeed indicator needle shot up into the red arc! Though buffetted,
the aircr aft remained controllable. The pilot considers the onl y real danger was the effect of the gust
on the a ircraft's structure as the airspeed indicator
showed an increase of some 60 knots. Had the whirlwind been fully developed, he feels that structural
overloading could have resulted in airframe failure.
• Ano ther pilot said he had seen the roofs of two
houses a t Richmond lifted by dust devils and the
sheets of galvanised iron carried half a mile. H e believes that light aircraft would certainly be lifted if
not pegged down . On one occasion a Cherokee Six
tied d own at Windorah with four 16 mm diameter
ropes was tipped on to its back when a whirlwind
snapped two of the ropes. Another pilot told of a
Piper Colt which had just been wheeled from a hangar in the course of a 100 hourly mspection. Before
those pushing it had time to walk back into the hangar, a whirlwind had struck the aircraft, picked it
up and dropped it again upside down, d amaged
almost beyond repair.
The conditions necessary for the fo rmation of dust
devils are fairl y well kn own. T hey occur most frequently
in arid coun try where there is little surface vegetation
and much loose surface dust, though the dust need no t
be thick. I n country where sca ttered trees and sparse
vegetation alternates with areas where there are no trees
or grass, dust devils are intermittently visible. They are
seldom seen over salt marshes, well-watered grasslands,
or truck forests.
Meteorologically, dust devil formation requires strong
surface heating for some hours with little surface wind.
This implies a decidedl y super adiabatic lapse rate near
the ground with surface temperatures in the region of
60°C to 70°C and cloudless skies or at least well-scattered
high level cumulus cloud. These condi tions prevail in
inland Australia during the warmer months.
Dust devi ls also occur along the sea breeze front in hot
arid or semi-arid regions such as in the Gulf coun try of
Q ueensland and the north west of Western Aus tralia.
'I nvisible dust devils' or whirlwinds can occur after a
good season when there is more grass.
In his concluding remarks, the author of the paper
points out that dus t devils, whether visible or not, are a
hazar d to light aircraft taking-off or landing. Moreover
disturbances have their greatest energy near the ground
when the pilot's attention is concentrated on flying the
aircraft, rather than watching for evidence of whirlwinds.
At higher levels, where there is more airspace to
manoeuvre, the dangers are not so great, but loss of control at any time can be frightening. The risk of loss of
control seems to be greater in the upper part of the disturbance where the rising air colu mn changes its structure by spreading and contains areas of subsiding air
which find their own density levels after having been carried higher than that level by the dust devil's inertia.
Here the aircraft's lift can be affected, resulting in sloppy
control responses. This disturbed region of air is seldom
visible but ex tends for about 2000 feet above the visible
dust column . I t will usually follow the extension of the
column of dust; i.e. if the dust column is vertical, then
the area is usually directly above it; if the dust column
is sinuous, then the area is beyond and in line with the
path of th e dust column.
The author suggests that pilots who have gained the
bulk of their experience in coastal areas may be blissfully
unaware of the possible consequences of operating in dust
devil conditions. Th us a 'coastal' pilot's first encounter
with a dust devil while landing at an inland strip could
well result in an accident. F or such as these, the following
advice is offered:
• In dust devil areas, watch the tall grass movement
when landing as this will give an indication of the
invisible dust devil.
• It is better to fly at middle levels and put up with
the turbulence, than to wallow uncontrollably at the
'cauliflowering' level.
• Confine flying to morning hours whenever possible.
• Avoid dust devils wherever possible, and delay
landing until the strip is clear of dust devils.
• Dust devils are not dangerous to experienced pilots
but must be treated with respect at take-off and
landing.
• On the ground, light aircraft should be securely
pegged down if not parked in a substan tial hangar.
-
page 21
�Ask
foR HELp-
WliiLEYou
STill CAN/
(P ilot Contribution)
I detect a fairly prevalent feeling among pilots that D epartmental officials are regarded wi th the same kind of
suspicion as school teachers or policemen. The attitude
is that Flight Service a nd similar staff are to be given
a wide berth - or you could end up with a fistful of
225s. This seems to me to be another factor in the chain
of events that can lead to dangerous situ a tions for pilots
a nd passengers.
I would therefore like to describe an incident with the
object of highlighting how liaison with Flight Service can
make life safer for the pilot. During my flying career I
h ave often sough t the guidance of Flight Service. They
have usually put their suggestions in a tactfu l, indirect
fas hi on - presumably because their transmissions are
recorded. Bu t from the Departmental point of view, I am
sure th a t helping to keep pilots out of trouble is far more
important tha n castigatin g them or, worse s till, having
to pick up the pieces after a crash.
My own s tory is about a flight from C lermont to
Maroochydore where I was to spend Christmas. At the
time of the incident I had a private licen ce, abou t 400
hou rs in command, and a new Night VMC rating. Most
of my hours had been gained in remote areas of the Gulf
country and northern Queensland. The aircraft was a
Cessna 172 with VO R, ADF, and long range tanks. On
board with me were my wife and infant son . We were
tracking direct from Clermont to Maroochydore a nd had
ad equate endurance to complete the fligh t safely.
The flight started in the morning in fine clear weather
and the forecast indicated suitable weather for the flight.
H owever, th e indications were that deteriorating conditions could b e expec ted towards th e coast late in the
afternoon with build ups of cumulonimbus clouds, thunderstorms a nd rain squalls. This forecast was quite accurate and by Eidsvold we were looking carefully at the
situation. By Gaynd a h there was storm activity a nd occasional squalls. We d ecided to keep going, bearing in
mind tha t the weather activity was only scattered, with
a high cloud· base a t 5000 feet, and that the coas t to th e
east was still clear as the weather was coming from the
south south west, so that Maryborough was CAVOK and
a safe haven if need ed. Our endurance was adequ ate to
fly to alterna tive des tina tions safely, a nd we had plenty
of daylight left.
Abeam Gympie, Brisbane called me up and asked for
a report on the weather in my area. By this stage there
were very heavy clouds rollin g in from the south west,
areas of dense thunderstorm activity and heavy rain
squalls. We kept going because Maryborough was still
fine and because Brisba ne advised us that the weather
along the remainder of my track was still VMC. Things
in the Maroochydore direction certainly did look more
pleasant than Gympie.
By Cooroy I decided to give flying away for a while
and see how the weather developed. I did not know the
area well for one thing, a nd secondly conditions were
now deteriorating too fast for comfor t. I told Brisbane
of my decision and asked them to advise what strips were
in my area. By this time I could still see the strip at Noosa
but it was rapidly disappearing in a rain squall. Flight
Service advised that there was a nearby p rivate strip close
to a set of white cattle yards on the northern end of a
lake. At this stage also I could still have safely made
Maryborough .
We landed without trouble at this bush strip and
waited fo r a while. After about half a n hour the rain stopped a nd the clouds lifted a little. I rang a friend at
Maroochydore for a report on conditions there. I also
rang Brisbane Flight Service. On the basis of my local
observations and the reports from Brisbane and
M aroochydore I decided to continue, overflying Noosa
strip for safety. At th e time of take-off, conditions were
VFR at th e destin ation and apparently alon g the track.
The flight to Maroochydore should have taken about 20
minutes.
However, a few minutes later a heavy rain squall
moved along th e coast towards us. The clouds had again
descended to hill top level, so our bush strip was now h idden by cloud. We looked in the Maryborough direction
to see that blanked ou t also.
At this stage I was circling above a very grey sea j ust
ou t from the beach at about I OOO feet. That beach looked
very welcoming. Just as I had finally decided that the
beach was the place to head for, Brisbane called me to
ask if I could maintain VMC . My p rompt reply was:
'Negative, an d there is a nice stretch of beach down
b elow wh ere I intend to l and.'
We did a normal circuit and landed with full flap and
minimal airspeed. I j udged that the beach would be hardest where the wet sand merged into the dry. All went
well and SARWATCH was cancelled from the beach.
I rang Brisban~ FS from Tawantin rather, expecting
a blast for landmg on a beach. T he reaction was,
however: 'Well, you would have been a bloody fool if
you had done anything else! Happ y Chris tmas !'
So thank you, DoT staff, for you r help to me a nd my
family on several occasions. May I say to other raw pilots
that if you find yourself in a tight spot, liaise with Flight
Service for advice, make up your own mind ultima tely
on your course of action, but do not leave either the
liaison or the decision-making too late.
Comment
We too endorse the pilot' s decision to land on the
beach, in a situation where there was no reasonable
alternative. But, unless you know the particular beach
treat it with respect, particularly in nose wheel aircraft.
There may be soft patches in what seems to be a firm
surface. - - - - - - - - - - -- - - - - - ..,,...--
ThE BREATlt of LifE
At fi rst glance the details of the flight might not have
seemed particula rly unusual - just a Cessna 172 on a
private VFR flight from Broken Hill to a country town
m S?uth Australi a. But it didn't take the Adelaide flight
service officer long to notice one thing that was out of
the ordinary. The pilot h ad reported to Broken H ill that
he was cruising at flight level 140. A Cessna 172? At
14 OOO feet? The Adelaide FSO called the aircraft and
spoke to the pilot. The pilot's reply seemed slurred and
his wo:ds were pronounced very slowly. 'Are you equipped with oxygen ?' the FSO anxiously enquired. 'Negative,' was th e answer!
The FSO im mediately sugg~sted that the pilot begin
a descent to below 10 OOO feet. The pilot followed this
advice, although his radio communications continued to
suggest a men tal state of confusion and drowsiness.
However , once th e air craft had descended there were no
fur ther problems and the rest of the flight was without
incident.
The pilot later explained that he had climbed to flight
level 140 to try a nd avoid the strong head winds he had
encountered at 6000 feet, the altitude h e had origin.a lly
planned. Altogether, the aircraft was above 10 OOO feet
for about 35 minutes. Throughout this time, of course,
t~e pilot should have been using oxygen. Although the
fligh t ended safely, it is quite possible that had it continued at such a high altitude, the progressive onset of
hypoxia (oxygen deprivation) could have led to a
dangerous situation.
Several years ago, the D igest discussed the need to use
oxyg~n at altitud e in the article 'Oxygen, the Life Giver',
published in I ss ue No. 66. The following extract is p ertinent to th e inciden t described a nd worthy of repetition:
The altitude at which the onset of the effects of hypoxia occur
varies with the individual to some degree and with the period of exposure to lack of oxygen. Poor physical condition, for instance,
lowers the body's tolerance to altitude. But no matter how fit a person
may consider himself to be, the onset of hypoxia is insidious, producing symptoms not likely to be recognised by the subject himself. The
lack of oxygen has its effect first on the most highly developed cells
of the body: those of the brain. Night vision, the ability to see in 'the
dark', is actually affected as low as 4000 feet. Fatigue, consumption
of alcohol, sleep-inducing drugs and carbon monoxide all increase
the likelihood and effect of hypoxia. The blood of heavy smokers
contains 5 to 10 percent carboxy haemoglobin and as this percentage is unusable for carrying oxygen, heavy smokers, as far as
physical effects are concerned, have to be regarded as several thousand feet 'above' the actua l cabin altitude.
At 10 000 feet, the upper limit to which flight crews may operate
in non-pressurised aircraft without supplemental oxygen, a definite
degree of hypoxia can take place during a prolonged flight: there
is a gradual impairment of the pilot's judgement, co-ordination and
ability to assess a flight situation. At 14000 feet the effects become more pronounced: thought processes and memory are
impaired and headache, dizziness, fatigue and slurred speech occur.
The nails and lips may become blue.
At 16000 feet disorientation, belligerence and an overconfident feeling of well-being are common symptoms, effects much
like those of alcoholic intoxication, a 'not caring a damn' feeling . Between 18 OOO feet and 20 OOO feet, unconsciousness, akin to
a fainting attack, may occur. The time taken for hypoxia to cause
unconsciousness shortens rapidly as the altitude increases.
L ack of oxygen is an insidious hazard. I t is all the more
dangerous because the pilot affected b y it is usually
unaware that he has a problem. So, when fl ying high,
remem ber: oxygen is the breath of life.
page 23
page 22
�...
l
INCREDIBLE/
CouMiNG Si-IEEp?
Before landing in a paddock, the you ng woman pilot of
a Cessna 172 made a low run to clear sheep from her
intended landing path. She h ad operated regul a rl y into
the paddock a nd frequently had to clear a pa th in this
way before landing.
The p ilot h ad planned another fligh t later in the day
to ta ke three passengers some 200 kil ometres to another
property. They had intended to leave about midafternoon but, when they eventually arrived at the
aircraft, they were already half a n hour late. While the
passengers loaded their personal baggage on board, the
pilot walked along her intended take-off path to the top
of a slight r ise in the paddock to check the posi tion of
the sheep. She saw they were in two g roups on ei ther
side of the landing area with a gap in be tween of a bout
60 to 70 metres. Returning to the aircraft, she carried
out a pre-flight inspection but then discovered sh e h ad
View of paddock from which Cessna was operating, looking in direction of take-off. Three of the four sheep the aircraft struck, and the
dislodged nose wheel, can be seen in the picture.
lost the aircraft's ignition key. An exhaustive search failed
to find it and the pilot finally decided to drive back into
town to pick up a n other key. The time taken by the
search and the drive into town and back delayed the departure by a furth er 40 minutes. On her way back wi th
the spare key, the pilot saw the sheep in th e distance and
it seemed they were still in m u ch th e same position.
By now, ti me was growing short for the aircraft to
reach its destination before last light, so the passengers
q uickly reboarded the aircraft and the pilot, after startin g
the engine and completing her pre-take-off checks, b egan
to take-off wi thout delay.
As the aircraft topped th e rise a t a bout 4 5 knots, the
pilot saw a sheep come from her righ t side a nd s ta rt to
cross the take-off path. Characteris tically, others
immed iately began to follow. Seeing tha t she was on a
collision course with the animal, the pilot tried to pull
the aircraft into the air. But she was unsu ccessful , and
the aircraft s tru ck the first sheep wi th the propeller.
There seemed to be no damage, so the pilot decided to
continue h er attempt to become a irborne and avoid other
sheep n ow moving quickly across ahead of her.
The aircraft struck a second sheep with a h eavy
impact, the nose leg was torn off and the aircraft began
to lose speed. Even so, the pilot was apparently undeterred a nd did n ot throttle back. The aircraft struck two
more sheep and finally the n ose dropped , th e propeller
slashed into the ground a nd the aircraft somersaulted on
to its back.
The p ilot and two passengers suffered minor injuries,
apparently inflicted b y a n attache case, a n overnight bag
a nd a wa ter bot tle which had been s towed unrestrained
behind the rea r seat on the baggage shelf. The aircraft
was extensively damaged.
While carrying out mustering operation s in W estern A ustralia, the pilot of a Cessna 150 fou nd th a t the use of th e
aircraft's warning horns was insufficient to m ove a group
of presumably rather aloof cattle out of thick scrub.
The pilot therefore decided to use his own technique
of ma king the aircraft' s engine backfire by switching the
magnetos on and off. As he was doing so h owever, the
lock nut which holds the switch in p lace on the panel
came off, and the magneto switch fell out on to the floor
- in the off position, wi th the key out of the lock, and
with the aircraft only about 50 feet a bove ground!
At the moment the engine failed, the pilot had just
begun a s teep climbing turn a t an airsp eed of a bout 60
knots. Immedia tely h e applied nearly foll forward pressure on the control column to maintain a irspeed, aqg
selected full flap. The aircraft just missed the tops of
nearby trees a nd the pilot managed to put it down in
a small clearing surrounded by rough spinifex, a nt hills
a nd trees. Miracu lously the aircr aft suffered no damage
a nd the pilot was uninjured. The report does not reveal
what the cattle though t.
Needless to say, though the pilot claimed his techniqu e
is used 'by all mus tering pilots', it is not the recommended one! We shudder to thi nk what all those backfires must do to the en gine - we wou ld n't do it to a
car let alon e a n aeropla ne!
':f'he. practice of deliber a tely 'backfiring' an engine by
~witc~mg the m agnetos on and off imposes severe fatiguem.du~mg loads on the propeller , crankshaft, and gearing
w1~hm the engine a nd th e exh a us t sys tem. It may even
stnp the teeth of the plas tic d is tributor gear in the magn etos themselves. Higher powered engines are even less
tolerant to this type of abuse.
Comment
T o comment on the lessons of this accident would be
superflu ous - the even ts speak for themselves!
page 24
These two examples of failed plastic
distributor gears testify to the consequences of deliberately causing an
engine to backfire.
page 25
�IRRITANT
POISON
An increasing number of accidents and incidents resulting from the carriage of improperly- packaged dangerous
goods has alerted the aviation world to the inherent
hazards of this problem. There is, however, a widely-held
belief in the industry that this is exclusively the concern
of the airlines.
General aviation aircraft, whether commuter, charter,
aerial work or private, are equally vulnerable. A fire
started by loose .book matches in a sui tcase, or dense
smoke res ulting from spillage of ni tric acid, is of as much
concern to the pilot of a Cessna 172 as to the crew of
a 747.
The reason for this apparent sense of complacency
amongst ge neral aviation pilots understandably a rises
from the fact that the majority of reported dangerous
goods problems come to lig ht in the course of a irline and
large charter operations. The following cases are typical:
• A cargo aircraft crashed , killing the three crew
members, while a ttempting an emergency landing.
lt was later determined that control of the aircraft
was lost because of dense smoke on the flight deck
which the crew incorrectly assumed to be caused by
an electrical fire. The smoke, in fact, was the r es ult
of leakage of nitric acid which had been improperly
packed and improperly loaded, and which the crew
did not know was on board.
• After landing, seven out of ten occupants of a passenger aircraft, including the flight crew, were found
to be suffering from the effects of toxic-gas inhalation. The poisonous fumes came from a leaking
drum of hydrofluoric acid. The relevant regulations
did not even permit the transport by air of this substance, which was in any case inadequ ately packed.
The aircraft stru cture a lso was damaged by the
highly corrosive acid.
• During the unloading of cargo from a jet aircraft,
a five gallon drum was found to be leaking. Ten persons were contaminated by the leaking liquid and
were treated in hospital for severe burns. It was determined later that the liquid was a corrosive chemical but that the required warning labels had no t
bee n affixed to the drum.
No mention of general aviation - but that does not
mean that general aviation aircraft a re immune. All
pilots will accept that they must, at one time or a nother,
and perhaps unwittingly, have carried some article, some
package, some baggage or cargo containing paint, thinners, aerosol containers, battery acid, insecticide, weed
killers, caustic soda, or some other of the over 2000
different items listed as restricted articles.
Most of these everyday things can be carried in aircraft
quite safely, provided they are properl y packed or protected according to their particular needs. In most cases
it is the form of a substance and the quantity in a particular container that dictates the precautions necessary
to transport it by air. It is vital that the crew know
exactly what goods they are carrying and where they are
s towed - not only to prevent two totally incompatible
articles getting together and blowing holes in the
fuselage, but to plan for in-flight emergencies tha t might
arise from the particular cargo.
An Air Navigation Order (Part 33) dealing with the
carriage of dangerous goods has been in existence for
years, but this has not prevented incidents in which crews,
passengers and aircraft have been exposed to danger because improperly packed or excessive quantities of
poisonous, explosive, flammable or corrosive materials
have passed undetected through the loading sys tem and
been carried on aircraft. In many cases, the problem begins with the individual because he fails to realise that
some su bstances, whilst relatively harmless in normal circumstances, require special packaging and handling for
air transportation by reason of, amongst other things, the
pressure and temperature changes involved.
There is a world-wide movement toward more stringent
rules for controlling the carriage of hazardous cargo - in
all modes of transport - including the training of personnel in the handling and packaging requirements. In Australia, the relevant Air Navigation Order has been
reviewed in recognition of the differin g needs of the industrialised sectors and of operators serving the remote areas,
to reflect the need to train persons in the recogni tion and
handling of dangerous goods, and to provide a feedback
by which the efficiency of the system may be assessed.
The International Air Transport Associa tion (IATA)
has developed Restricted Articles Regula tions to specify
the maximum quantities and the packaging, labelling
and handling requirements applicable to more th an 2000
different types of dangerous goods, many of which are
more commonly associated with the urban lifes tyle.
These regulations have been widely accepted internationally, and compliance with them is required in Australian air operations.
T he IATA Regulations make allowances for personal
effects carried by passengers for their own use, as indicated in the following extract:
CARGO Al RCRAFT ONLY LABEL
V2 kilogram or % litre (1 pound or 16 fluid ounces).
(b) Alcoholic beverages carried by passengers or crew as
checked hand or hold baggage.
(c) Alcoholic beverages, perfumes and cologne when boarded
by the aircraft operator for use or sale on the aircraft.
(d) With approval of the carrier (s) small oxygen cylinders for
medical use and small carbon dioxide gas cylinders for use
by passengers for the operation of mechanical limbs.
(e) Dry ice in quantities not exceeding 2 kilograms (4 pounds)
per passenger, used to pack perishables, as carry-on baggage only.
(f) Installed cardiac pacemakers.
(g) With approval of the carrier(s) as checked baggage only,
small arms ammunition (for sporting purposes). In quantities
not exceeding 5 kilograms (10 pounds) for personal use, excluding those with explosive or incendiary projectiles.
Private operators are responsible to themselves for
achieving the level of safety being sought. Just as you
plan your business budget, or your holidays, so too should
you plan common sense measures to ensure that some
angry item of cargo does not become difficult inside your
aeroplane - in-flight.
-.-.,_.
---~
Restricted Articles subject to the requirements of these Regulations shall not be carried in the same compartments occupied by
passengers and neither shall such restricted articles be carried
in passengers' or crew checked or carry-on baggage. However,
these regulations shall not apply to the following:
(a) Medicinal and toilet articles, which are necessary or
appropriate during the journey such as hair sprays, perfumes
and medicines containing alcohol. These may be carried in
hold or cabin baggage when the total net capacity of all
packagings used by the passenger for these articles does not
exceed 2 kilograms or 2 litres (75 avoirdupois or fluid ounces)
and the net capacity of each single package does not exceed
page 27
page 26
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YouR Rolf iN SEARcli ANd RESCUE
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To most pilots, the words 'Search and Rescue' conjure
up what seems a pretty remote possibility. After all, forced landings or ditchings, with their subsequent rescues
arc things that happen to someone else! And of course,
being called upon to rescue survivors from such misadventures is no less heady!
Ye t regardless of the type of flying in which we may
be involved, it is possible for some of us to find ourselves
part of a search and rescue operation. Whether we fly
the oceans of the world in a Boeing 747, or spend our
days rounding up cattle in a Cessna 150, we can all be
called upon to assist in some way when an emergency
a rises. The form of assistance each of us is ab le to render
w ill vary enormously, but it is important for all to understand both the Department's and pilots ' roles in the Australian search and rescue organisation.
Through the Department of Transport, Australia discharges obligations, assumed under the In terna tional
Civil Aviation Organisation and the Air Navigation Act
and Regulations, for search and rescue of survivors of
civil aircraft invol ved in crashes, ditchings and forced
la ndings. Also, under the Australian Navigation Act and
the
Inter-Governmental
Maritime
C onsultative
Orga nisation , Australia has responsibility for the rescue
of survivors of shipping disasters at sea. Under various
Commonwealth-State agreements too, search and rescue
assistance is provided to States when a p articular operation is be yond that State's resources. In simple terms, this
means that any pilot can be called upon to take part in
a SA R action for missing vessels, yachts or boats operating close to the coast, or for lost hikers, bush walkers or
children.
Because Australia does not have the resources to maintain a standing search and rescue service such as the
United States Coast Guard, it has developed a system
under which both civil and military aircraft and crews
can be called upon when required. Some people seem
to think that the only aircraft suitable for search and rescue operations are L ockheed Orions or similar specialist
types, as indeed they are in some circumstances. But in
others they are not, and as these service aircraft may well
be d eployed in their primary role of defence, they may
not be available when and where required. Indeed, in
some situations, particularly in outback or mountainous
areas, the local operator, who is readily available and
knows the area and its features intimately, offers a more
practical SAR unit.
page 28
The conduct of a search and rescue operation calls for
considerable expertise on the part of the specialist staff
who co-ordinate and control th ese operations. Departmental personnel arc trained in aviation search and rescue
activities, and thus have the responsibility for selecting
aircraft for each individual task. In doi ng this, they consider all pertinent factors such as availability, location,
enduran ce, manoeuvrability, and cr'ew experience.
Search and rescue operations require special
procedures over and above those normally used by pilots,
particularly in regard to navigation a nd flight patterns .
And of course they pose a num ber of q ues tions such as:
• What am' I looking for and how wi ll I recognise it?
• Where do I look and how is the search a rea calcul ated?
• What height do I fly at a nd what determines this?
• Why has my aircraft been selected?
• H ow will I manage to cover the area asked of me?
• What do I do if I see somethi ng?
• Who will be on .b oard to help me?
• Who makes the decisions?
• Who authorises the expense incurred?
• H ow many times will the area be searched ?
• What are the cha nces of seeing anything?
• How do I drop equipment without previous experience?
Obviously the list is far from exhaus tive, for the subject
is a broad one. For the same reason, it is not one that
can be dealt with adequately in j us t o ne or two pages
of the Digest. I t is the refore in tended to publish a series
of ar ticles on the various aspects of search a nd rescue
operations and how they affect pilots. These are to appear in successive issues of the Digest under the following
broad headings:
• The Departmental SAR organisation, its facilities,
staffing and training.
• How search areas are calculated.
• How aircraft are selected and allocated to areas.
• H ow th e target is recognised and the probability of
detecting it.
• Supply dropping and rescue operations.
In this way it is hoped that all p ilo ts will gain some
understanding of search a nd rescue operations in Australia and the part they wou ld be expected to play in
them should they be called upon to participate in such
emergency situations.
---
�
Dublin Core
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Title
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Aviation Safety Digest
Text
A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text.
Dublin Core
The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.
Title
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Aviation Safety Digest, number 101 (1978)
Identifier
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101
Date
A point or period of time associated with an event in the lifecycle of the resource
1978