As a result of this occurrence, the Australian Transport Safety
Bureau (formerly BASI) is investigating a possible safety
deficiency 19990038 that relates to the security of airfields in
the Torres Strait against public access.
Any safety output issued as a result of the analysis of safety
deficiency 19990038 will be published in the Bureau's Quarterly
Safety Deficiency Report.
- The pilot initiated a go-around from final approach because of
a vehicle on the airstrip. - The left propeller showed little evidence of rotation damage.
The reason for a possible loss of left engine power could not be
determined. - For reasons that could not be established, the pilot lost
control of the aircraft at a low height.
The flight
The flight apparently proceeded normally until late final
approach when the pilot initiated a go-around because of a vehicle
on the airstrip. There were clear indications from the wreckage
examination that the aircraft was rolling and yawing left at
impact. The status of the left engine at impact logically supported
such aircraft behaviour. While the witness description of the
aircraft initially veering left also supported this conclusion, the
report that the aircraft rolled right immediately before impact did
not. In the asymmetric power and low speed situation that existed,
it was most unlikely that the aircraft could have rolled right. On
balance, therefore, the direction of roll as recalled by the
witnesses was incorrect.
Whether the vehicle entered the airstrip during the latter stage
of the aircraft's approach, or whether it was on the airstrip and
the pilot expected it to move, was not determined. However, the
position of the wing flaps at impact suggested that the pilot had
selected full flap, and that the flaps subsequently did not move
from this position. This implied that the pilot had been committed
to land and that the aircraft speed was at, or less than, 65
kts.
Under normal circumstances, a go-around with both engines
operating would have been a relatively basic procedure for the
pilot to conduct. Because there was no apparent earlier action or
radio call, it is unlikely that the pilot was aware of an
asymmetric engine condition until the go-around was initiated. When
the asymmetric power condition arose, the pilot's task was
complicated by a number of aspects:
- the aircraft was at low level, and probably low speed, when the
go-around was initiated. This would have provided minimal
opportunity for the pilot to lower the nose of the aircraft to
increase airspeed and hence aircraft controllability; - depending on the exact position of the aircraft when the
go-around was initiated, the pilot may have had to manoeuvre away
from the sand dune and coconut palms on the southern side of the
strip; - the pilot had to deal with the control forces associated with
the asymmetric power condition, in addition to those associated
with the engine power increase; - to retract the flaps to the take-off position, feather the left
propeller, and adjust the elevator and rudder trims would have
required the pilot to fly the aircraft with her left hand while
conducting these other tasks with her right hand. Completion of
these tasks may have been difficult, if not impossible, in that
control of the aircraft may have required the pilot to use two
hands on the control yoke to overcome the out-of-trim forces; - the pilot's stature, seating position as altered by the
cushions she normally used, and the position to which the rudder
pedals had been adjusted, may have affected her ability to
manipulate the aircraft controls to the extent necessary to
maintain control of the aircraft; - at a speed of 60 kts, the aircraft would have taken about 7
seconds to travel from overhead the witnesses at the eastern end of
the island direct to the impact position. While the actual aircraft
track was not established, this timeframe was probably indicative
of the period available for the pilot to recognise the situation,
evaluate available options, decide what action should be taken, and
initiate that action; and - the north-westerly wind would have exacerbated any tendency for
the aircraft to drift left as a result of the asymmetric power
situation.
These influences would have placed the pilot under an extreme
combination of workload and stress and may have affected her
decision-making and flying ability.
An alternative course of action available to the pilot was to
overfly the vehicle and land the aircraft on the remaining section
of strip. Another was to reduce power on the right engine and
conduct an emergency landing on the tidal flat area. However,
without accurate information concerning the position and altitude
of the aircraft when the go-around was initiated, no positive
conclusions could be drawn concerning these options.
Wreckage examination
The pre-impact position of the carburettor heat controls for
both engines could not be positively determined. It is possible for
ice to have formed in one carburettor and not the other. If ice was
present in the left engine carburettor during the approach, it was
unlikely to have been evident to the pilot because the engine was
probably operating at low power. Such a condition could have caused
the engine to fail to respond at the commencement of the go-around.
Because of the salt water corrosion damage, it was not possible to
assess the pre-accident condition of the carburettor. It is also
possible that aggressive throttle operation by the pilot at the
commencement of the go-around could have affected normal engine
operation. In summary, there was insufficient evidence to reach a
positive conclusion concerning the operation of the left
engine.
Examination of the aircraft wreckage did not reveal any evidence
to link the circumstances of the accident with the defects listed
in ASR 111642, or those subsequently rectified on 2 January 1999.
Further, no evidence was found of any aircraft unserviceability
being reported and/or recorded between 2 January and the accident
flight.
History of the flight
Uzu Air conducted passenger and freight operations between Horn
Island and the island communities in the Torres Strait. It operated
single-engine Cessna models 206 and 208 aircraft, and twin-engine
Britten Norman Islander aircraft.
On the morning of the accident, the pilot flew a company Cessna
206 aircraft from Horn Island to Yam, Coconut, and Badu Islands,
and then returned to Horn Island. The total flight time was about
93 minutes.
The pilot's schedule during the afternoon was to fly from Horn
Island to Coconut, Yam, York, and Coconut Islands and then back to
Horn Island, departing at 1330 eastern standard time. The flight
was to be conducted in Islander, VH-XFF. Three passengers and about
130 kg freight were to be carried on the Horn Island - Coconut
Island sector. Another company pilot had completed three flights in
XFF earlier in the day for a total of 1.9 hours. He reported that
the aircraft operated normally.
Witnesses at Horn Island reported that the preparation for the
flight, and the subsequent departure of the aircraft at 1350,
proceeded normally. The pilot of another company aircraft heard the
pilot of XFF report 15 NM SW of Coconut Island at 3,500 ft. A few
minutes later, the pilot reported downwind for runway 27 at Coconut
Island. Both transmissions sounded normal.
Three members of the Coconut Island community reported that, at
about 1410, they were on the beach at the eastern extremity of the
island, about 250 m from the runway threshold and close to the
extended runway centreline. Their recollections of the progress of
the aircraft in the Coconut Island circuit are as follows: the
aircraft joined the downwind leg and flew a left circuit for runway
27; the aircraft appeared to fly a normal approach until it passed
over their position at an altitude of 200-300 ft; and it then
veered left and commenced a shallow climb before suddenly rolling
right and descending steeply onto a tidal flat, about 30 m seaward
from the high-water mark, and about 200 m from their position.
Injuries to persons
| Injuries | Fatal | Serious | Minor | None | Total |
|---|---|---|---|---|---|
| Crew | 1 | - | - | - | 1 |
| Passenger | 2 | 1 | - | - | 3 |
| Ground | - | - | - | - | - |
| Total | 3 | 1 | - | - | 4 |
Damage to aircraft
Severe disruption to the outer right wing and nose sections
occurred as a result of impact forces. Less significant damage
occurred to the outer left wing leading edge. The fuselage
fractured just aft of the wing trailing edge. The wing attachment
points failed, allowing the wing to rotate forward and partially
crush the cockpit/forward cabin area. There was a compression
fracture of the upper surface of the left horizontal stabiliser
near the inboard end. The outboard end of the left stabiliser had
been bent upwards by ground impact.
Other damage
There was no other damage.
Personnel
- Pilot
Age: 27 Licence category: Commercial Medical certificate: Class 1 (valid to 27 June 1999) Instrument rating: Command Multi Engine Total flying hours: 2,540 Total on type: 197 Total last 90 days: 205 Total last 24 hours: 2 Last flight check: 12 November 1998
- Flying experience and qualifications
The pilot began flying in 1990 and gained a Private Pilot
(Aeroplane) Licence on 21 March 1991. She was issued with a
Commercial Pilot Licence on 18 August 1994 and gained a Command
Multi-engine Instrument Rating on 21 October 1996. On 1 February
1995, the pilot qualified as a Grade 3 Fixed Wing flying
instructor, and gained a Grade 1 instructor rating on 25 September
1997. She was issued with a multi-engine training approval on 30
March 1998.As well as being qualified to fly Islander aircraft, the pilot
held endorsements on a number of other twin-engine aircraft,
including Aero Commander, Beechcraft Baron, Cessna 310, Piper's
Navajo, Seneca, and Seminole.The pilot completed her endorsement on the Islander on 10
September 1998 and a proficiency check on 16 September 1998. The
endorsement and check reports indicated that the pilot operated the
aircraft at a high standard, and was disciplined and thorough with
checks and procedures. No significant deficiencies were recorded.
The training included asymmetric handling sequences, one of which
was a simulated single-engine go-around from final approach with
the wing flaps at the take-off position.The pilot completed airfield checks at a number of airstrips in
the Torres Strait, including Coconut Island, on 12 November
1998.- Seven-day history
The following summary of the pilot's flight and duty times was
taken from company records:
Date Duty hours Flight time (hours) 9 January 0630-1800 4.1 10 January day off nil 11 January 1200-1800 nil 12 January 0700-1800 4.8 13 January reserve nil 14 January 0700-1830 7.3 15 January day off nil Associates of the pilot reported that she appeared in good
health on the morning of the accident.- Seat cushions
The pilot was approximately 157 cm tall. The operator reported that
the pilot used two foam-rubber cushions (one on the seat and the
other against the seat back) to adjust her seating position to
enable her to achieve full movement of the cockpit controls. The
seat cushions normally used by the pilot were not found. No person
was found who could recall the pilot taking the cushions to the
aircraft before the flight. However, the cushions were not at the
company office where they were usually stored when not in use.
Assuming they were on the aircraft, it is likely that they were
lost as a result of the post-accident tidal and/or wind
action.
Aircraft information
- Significant particulars
Registration: VH-XFF Manufacturer: Britten Norman Pty Ltd Model: BN2A-26 Islander Serial number: C763 Country of manufacture: United Kingdom Engines: Lycoming O-540-E4C5 - Certificate of airworthiness
Number: CS/34 Issued: 18 December 1989 Category of operation: Normal - Certificate of registration
Holder: Uzu Air Pty Ltd Number: CNS/00034/04 Issued: 6 January 1994 - Maintenance release
Number: 285070 Issued: 5 December 1998 Valid to: 5 December 1999 Total airframe hours: 16,775.3 hrs - Weight and balance
The aircraft weight at the time of the occurrence was about 2,759
kg. The maximum allowable take-off weight was 2,994 kg. The centre
of gravity was within limits.- Maintenance history
An examination of the maintenance history of XFF revealed that the
aircraft had been inspected on 6 November 1998 by an airworthiness
officer from the Civil Aviation Safety Authority. As a result of
the inspection, Aircraft Survey Report (ASR)111642 was issued to
the maintenance organisation. The report listed five Code B and one
Code C defects. Persuant to Civil Aviation Regulation 38(1) the
maintenance organisation was required to assess and rectify Code B
defects as necessary. CASA form ASSP 604 states that "An
endorsement of the maintenance release in accordance with Civil
Aviation Regulation 50 may be required". Yes and no boxes, on the
Aircraft Survey Report (ASR)111642 dated 6 November 1998, to
indicate whether maintenance release endorsement was required, were
not entered. Code C defects constitute "a contravention of
requirements imposed under the Civil Aviation Regulations" and were
required to be assessed and rectified as necessary.The defects were:
- an oil leak in the left engine - Code B;
- the left landing gear torque links were worn at the pivot
points - Code B;- cracks in the left landing gear cowling - Code B;
- surface corrosion on the underside of the left wingtip - Code
B;- a broken bonding wire on the right flap - Code B; and
- there was no load limitation placard on the rear baggage door -
Code C.The aircraft log book recorded that the last Schedule 5 (100
hourly) maintenance on the aircraft was completed on 5 December
1998. There was no record that the defects notified in ASR 111642
had been rectified during the maintenance. The engineering manager
had certified an entry in the log book regarding the inspection. It
stated that there were no defects noted during the maintenance. The
aircraft was flown the following day.An entry in the aircraft log book dated 02 January 1999 listed
the following maintenance actions:
- An oil leak from the left engine was rectified by the removal
of the engine sump, replacement of the sump gasket and re-fitment
of the sump assembly.- Surface corrosion on the left wing tip was repaired.
- Stop drilling was conducted to control cracks in the left main
landing gear leg fairing.- A left engine cowl latch was replaced.
- Both left and right magnetos on the left engine were replaced
with overhauled units. This was done for convenience as the
replaced units were approaching the end of their in-service
lives.- The left engine lower mounts were replaced.
- The engine dual tachometer (RPM) instrument was repaired and
refitted to the aircraft.- Support brackets were fitted to the left engine exhaust.
- Bonding wire on the right hand flap was replaced.
- The right engine starter was lubricated.
- Engine intake ducting to the left engine was replaced because
of oil contamination.There was no record of any maintenance being conducted on the
left landing gear torque links.At the time the maintenance was carried out, the aircraft had
completed 19.6 flying hours since the issue of the maintenance
release on 5 December 1998. The aircraft then completed a further
43.9 flying hours before the commencement of the accident flight.
There was no record of any maintenance action being undertaken
during this intervening period relating the rectification actions
or any other matter.
Meteorological information
The Bureau of Meteorology advised that the probable weather at
Coconut Island around the time of the accident was as follows:
- Isolated to scattered showers, and isolated thunderstorms;
- North-westerly wind at about 15 kts;
- Generally good visibility but reducing in precipitation;
and - Broken cumulus cloud with a base at 2,000 ft, with broken
higher layers.
At 1400, the automatic weather station at Coconut Island
recorded an ambient temperature of 30 degrees Celsius, a dew point
of 25 degrees Celsius, and an atmospheric pressure of 1007
hectopascals. Witnesses at the island reported that the weather was
fine at the time of the accident, with the wind gusting from the
northwest.
Aids to navigation
Not relevant
Communications
The pilot was communicating on the area frequency of 120.3 MHz
during the flight. The pilot of another aircraft heard
transmissions from the pilot of the Islander on that frequency.
Aerodrome information
Coconut Island is about 110 km NE of Thursday Island. The island
is composed of coral sand and is predominantly flat. It extends
east-west for about 1.75 km, and is less than 0.5 km across,
north-south, at its widest part. The airstrip occupies the eastern
portion of the island and is aligned east-west. It is 880 m long,
60 m wide and composed of grassed coral sand. On the southern side
of the strip, and extending for most of its length, is a sand dune
approximately 5 m high with coconut palms growing on it.
The threshold for runway 27 is about 350 m from the eastern
extremity of the island. At the time of the accident, the local
refuse tip was situated between the end of the strip and the
eastern extremity of the island, and north of the extended
centreline of the runway. A dirt road linked the community living
area and the refuse tip. The road followed the southern side of the
strip to the eastern end before turning north towards the refuse
tip area.
Flight recorders
The aircraft was not equipped with flight data or cockpit voice
recorders, nor was such equipment required by regulation.
Wreckage examination
The wreckage was subjected to tidal salt water immersion for 3
days before it was examined.
- Airframe
An examination of the airframe did not reveal any fault that might
have contributed to the accident. All flying controls were capable
of normal operation prior to impact. The wing flaps were in the
full-down position at impact. The right wing fuel tank had been
ruptured by the impact, while the left wing tank was intact. A
significant quantity of fuel remained in the left tank.- Cabin
The pilot's seat was mounted on a frame attached to the cabin
floor. The seat could be adjusted fore and aft on the frame, but
there was no vertical adjustment. During the impact, the frame
partially collapsed down and towards the right. The seat was locked
in the full-forward position. The pilot's lap-sash harness assembly
remained intact during the impact.The rudder pedals were adjustable fore-aft into a locked
position as selected by the pilot. The rudder pedals on the left
side of the cockpit were locked one notch forward of the rearmost
position. Damage indicated that the pedals were locked in that
position at impact.The cabin was fitted with four bench-type passenger seats, each
capable of seating two persons. The seat frames were secured to the
floor. Two lap safety harnesses were attached to each seat
frame.At the initial examination of the wreckage, there were no
passenger seats in the cabin. All seats had been removed from the
cabin during the rescue activities. One seat, found above the
high-water mark, was recovered for examination. The remaining seats
were not found and probably disappeared as a result of tidal
action.Those involved in the initial response following the accident
indicated that one seat remained attached to the cabin floor and
was levered free with a crow bar. The remaining seats were loose,
apparently after becoming detached during the impact sequence.
Examination of the seat attachment points indicated that the first,
second and third row seat frames had failed due to impact induced
stresses. There was significant bending forward and to the right.
Examination of the seat found above the high-water mark indicated
that it was the rear seat that had been levered from the floor
during the rescue activities.Apart from the two safety harnesses attached to the rear seat,
only one-half of one other passenger harness was recovered. A
section of a broken seat attachment bracket remained attached to
the harness. The original location of the harness piece could not
be determined.- Engines and propellers
Both engines and propellers were recovered from the accident site
and examined. Disruption of the airframe prevented determination of
the position of the engine controls at impact.The right propeller exhibited signs of severe tip curl and
leading-edge abrasion, consistent with the engine developing high
power at impact. Examination of the engine did not reveal any
condition likely to have prevented normal engine operation.
Salt-water corrosion damage prevented a detailed examination of the
carburettor.The left propeller showed little evidence of rotational damage.
The propeller had not been feathered. Laboratory examination of a
failure of the left engine mixture control rod confirmed that the
failure occurred at impact as a result of impact induced stresses.
Examination of the engine did not reveal any condition likely to
have prevented normal operation. After sand and other internal
debris were removed, the magnetos were bench run for more than 30
minutes. They functioned normally during that period. The condition
of the carburettor prevented confirmation of its serviceability at
impact.- Carburettor heat system
The left and right carburettor heat control levers were mounted on
the lower quadrant of the cockpit centre pedestal. Both levers had
been bent flat against the pedestal face, and were in the OFF
position.The carburettor air intake system of each engine had been
destroyed during the impact sequence. Neither the pre-impact
position of the normal/alternate air doors, nor the condition of
the hot air flexible hose, could be determined.
Impact information
Consideration of the wing and nose section crush lines, along
with the nature of damage to the fuselage and horizontal
stabiliser, indicated that the aircraft was yawing and rolling left
at impact. The pitch attitude at impact was 40-50 degrees
nose-down. The right wing struck the ground first and bore the
principal impact. The nose section, and then the left wing outboard
leading edge struck the ground. Because of tidal activity, no
ground impact marks were evident. The aircraft speed at impact
could not be determined.
Medical and pathological information
The Bureau had not received the medical and pathological
information at the time of the release of this report.
Fire
There was no fire.
Survival aspects
The deformation of the nose section and the forward/downward
rotation of the wing significantly reduced the occupiable cockpit
space. This, along with the impact forces, meant that the chances
of survival for the pilot were low.
The surviving passenger indicated that she occupied the seat row
immediately behind the pilot. The other two passengers occupied the
second and third rows. The failure of the seat-to-floor attachments
of the occupied seats in the aircraft cabin indicated that
deceleration forces experienced in this area were high, thereby
reducing survivability.
Aircraft operation
- Emergency operating procedures
Section 4 of the Owner's Handbook for the aircraft type addresses
emergency operating procedures. Relevant extracts from the section
include the following:"Warning ...
It is essential to raise the flaps to the fully up position to
achieve the optimum climb gradient.""Critical engine
Failure of the left engine has the most adverse effect on the
handling and performance of the aircraft.""Landing with one engine inoperative
Make an initial approach to approximately 65 kt (75 m.p.h.) IAS
with the flaps selected to TAKE-OFF (25 deg). When committed for
landing, select FLAPS DOWN (56 deg) and reduce speed over the
threshold to a value compatible with the information scheduled in
Sect. 6 and touchdown normally."Section 3, Operating Instructions, of the Owner's Handbook,
included the following information:"Touch down
Initial approach should be made at 65 kts (75 m.p.h.) IAS with
flaps at TAKE-OFF (25 deg). After selection of FLAPS DOWN (56 deg)
the speed may be progressively reduced to the appropriate threshold
speed quoted in Section 6. After touch down allow the nose wheel to
sink gently and apply the brakes as required.""Baulked landing
Apply full power smoothly to the engines and be prepared to deal
with a nose-up change in trim which can require a strong stick
force, especially if the airspeed is low. Establish a positive
climb away, select flaps to T.O., trim the aeroplane and accelerate
to 61 kts (70 m.p.h.). Select flaps UP at a height above 200 feet
and climb out at 65 kts (75 m.p.h.) IAS."- Carburettor icing
Section 3, Operating Instructions, of the Owner's Handbook,
included the following information:"260 H.P. ISLANDER
Use of carburettor heat
Carburettor icing can occur, unexpectedly, in various combinations
of atmospheric conditions. On damp, cloudy or foggy days,
regardless of the outside temperature, keep a sharp watch for power
loss, indicated by a decrease in manifold pressure. When this is
seen, apply full carburettor heat for 30 seconds; this action will
cause a further slight drop in manifold pressure. Return the heat
control levers to OFF and note that selected engine power is
restored. Do not keep heat selected FULL for long periods or
excessive power loss will result, with very little indication from
the manifold pressure indicator. During normal flight operations
the carburettor heat control levers should be left in the OFF
position."Section 3 also included, in the "Airfield Approach" checklist,
the following comment on carburettor heat:"Intermittent use may be advisable to ensure responsive
engines if a baulked landing is likely and ambient conditions are
such that ice formation could occur."The temperature information supplied by the Bureau of
Meteorology for Coconut Island around the time of the accident
indicated that the atmospheric conditions were conducive to light
carburettor ice forming at cruise or descent engine power
settings.The company chief pilot knew of no instance of carburettor icing
in Islander aircraft operating in the Torres Strait. The normal
practice was that company pilots did not use carburettor heat
during flights in the area. Similar comment was received from other
organisations and pilots with extensive experience in operating
Islander aircraft in the Torres Strait area.- Aircraft wing flap operation
The Owner's Handbook, Section 2, titled Design Information, under
the sub-heading Flight Controls, contained the following
information:"Electrically operated single-slotted flaps are fitted.
An actuator on the wing rear spar operates the flaps through a
system of push-pull rods. A selector switch on the pilot's console
controls the actuator and a flap position indicator is situated on
the cabin roof instrument panel. The flap control selector switch
is a spring-loaded centre OFF unit and is wired to the actuator
through a system of relays. Moving the switch to the DOWN position
will only move the flaps 25 degrees to a TAKE-OFF setting and when
this setting has been reached a second downward switch movement
will be required to set the flaps to DOWN. Similarly, when raising
the flaps, the first switch movement will only raise them to the
TAKE-OFF setting and a second switch movement is necessary to
completely raise the flaps."Pilots who had flown the aircraft indicated that the flap
selector switch had to be held up or down against the spring, for a
short time, before flap movement commenced.
Aircraft single-engine climb performance
Section 1 of the Owner's Handbook for the aircraft stated that
the minimum control speed (single engine) was 39 kts. It applied
when the flaps were up and the propeller on the inoperative engine
was feathered.
Section 6 of the Owner's Handbook contained aircraft performance
data, including single engine rate of climb data at 65 kts with the
flaps up. The data indicated that, at an aircraft weight of 2,727
kg, an ambient temperature of 30 degrees Celsius, and at sea level,
the rate of climb the aircraft was capable of achieving with one
engine inoperative was about 160 ft/min.
The aircraft manufacturer advised that there were no actual
performance figures available for the BN-2A-26 Islander aircraft
with one engine inoperative, propeller unfeathered, and flaps down.
However, there were unofficial climb figures for a BN-2B-26 variant
of the Islander, with flaps up, and an unfeathered propeller. These
were measured under test conditions at 65 kts airspeed and
indicated that there was a decrement of between 70 and 90 ft/min
(depending on the unfeathered propeller RPM) below the scheduled
one-engine inoperative performance figures. The manufacturer also
advised that aircraft performance with both engines operating was
reduced by approximately 40 per cent when the flaps were selected
from up to down, although this data could not be applied directly
to flight with one engine inoperative. Go-around tests with one
engine inoperative and flaps down had not been conducted.
Pilots experienced on the aircraft type, reported that the
performance of the aircraft with flaps down and one propeller not
feathered was unlikely to allow a successful go-around to be
conducted.
Other information
- Information from surviving passenger
Approximately 6 months after the accident, the surviving passenger
provided the following information concerning the flight.
- She was seated in the row behind the pilot.
- One of the other passengers was in the second row, while the
third passenger was in the third row.- Her safety harness remained secured throughout the flight.
- There was no unusual event during the flight: the engines
sounded normal.- When the aircraft was on approach to Coconut Island, the pilot
said that they could not land because there was a truck on the
airstrip.- The passenger saw a vehicle on the strip. It was stationary,
and near the eastern end of the strip.- The pilot was cross and said that there was no driver in the
vehicle.- Other information from witnesses at Coconut
Island
At the time of the accident, an aircraft operated by another
company was parked at the western end of the airstrip. Two pilots
were loading a consignment of crayfish onto the aircraft. Neither
saw or heard XFF arrive in the circuit or fly the approach, nor
could they recall if a vehicle had been on the strip around the
time the aircraft was on approach. They indicated that their
loading activities, along with the existing wind conditions, would
have greatly reduced the likelihood of them hearing sounds from the
eastern end of the airstrip. They were not aware of the accident
until one of the island residents who witnessed the accident from
the eastern end of the island raised the alarm. They proceeded to
the accident site and, along with some of the island residents,
provided assistance to the victims as far as they were able. One of
the island residents advised the Thursday Island Police of the
accident. They arranged for a medical team and police to be flown
to the island in two helicopters. They arrived at the island
between one and one and one-half hours after the accident.None of the three island residents who witnessed the accident
reported seeing a vehicle on the airstrip when the aircraft was on
final approach.- Information from other company pilots
Other pilots working for the operator indicated that island
airstrips within the Torres Strait area were generally free of
obstacles for their operations. There had been occasions, however,
when vehicles, persons, or animals on the airstrip had caused
pilots to go-around from a landing approach, requiring them to make
a second approach.There were no radio links between aircraft and persons at the
island airstrips. Local populations relied on hearing and/or seeing
aircraft arriving to become aware of their presence. Depending on
the weather and wind conditions, pilots did not always overfly
airstrips before joining the circuit but often joined the downwind
leg before completing a base leg and landing off final
approach.- Birdlife on the airstrip
In the period during which the accident occurred, there were large
numbers of migratory birds on Coconut Island. Many hundreds were
seen occupying the grassed runway area. The birds were small and
difficult to see in the ankle-high grass. When approached by a
vehicle, they generally remained on the ground until the vehicle
was closer than 20-30 m. When they did fly, it was as a flock.The opinion of company pilots was that the birds were not
sufficiently large to constitute a significant safety hazard to
aircraft operations. They believed that the pilot would not have
discontinued the approach because of bird activity given their
small size, and given that an aircraft would normally have been
almost at the point of touchdown before the birds would begin to
fly. However, there was no evidence that the aircraft had struck a
bird.