Wreckage examination
The airframe had come to rest in an upright attitude, aligned about 250 degrees M, about 12 m north of the initial impact point. The wings, fuselage and empennage were in the normal places relative to each other. The fuselage had been destroyed by impact forces and post-impact fire. The wings displayed extensive post-impact fire damage. The empennage was relatively intact but had suffered some post-impact fire damage.
The engine had separated and come to rest inverted about 3 m west of the airframe and about 10 m north of the initial impact point. The axis of the engine was perpendicular to the axis of the airframe. The lower engine mount brackets had been severed and the engine mounts deformed, indicating an impact from the left side. The propeller had separated from the engine when the engine shaft failed due to excessive bending and torsion, and was buried 15 cm below the surface about 1 m from the initial impact point. Inspection of the propeller revealed one blade bent in the chordwise direction with the tip 14 cm aft of the normal position, indicating that it was developing power at the time of impact.
The flight control surfaces did not show any witness marks to indicate their pre-impact positions. The flight controls were cable operated and were found to be correctly and securely attached to their respective control surfaces. However, some cables had been torn off at the controls in the cockpit area. The flap extension lever was found in the stowed position. There was no evidence of the locking tongue having been forced over the slots. This indicated that the flaps had been retracted before impact.
The fuel system and components showed various degrees of fire damage. The remains of the fuel lines were in the expected locations and remained securely attached to their respective components. Both fuel caps were found mounted in the fuel filler ports and with their locking mechanisms closed. The examination of the fuel system did not reveal any pre-impact defect that would have prevented normal operation of the system. The extent of the fire attested to a significant fuel load on board.
Due to the intensity of the fire, no fuel remained in the wreckage. Two sets of fuel samples were taken from tank number four at Canberra Airport. The samples were assessed and found to be consistent in colour and appearance with 100LL Avgas, of normal density, and free from water. Several aircraft had refuelled from the same bowser earlier in the day. None of the pilots of those aircraft reported any fuel-related problems.
The engine was removed and stripped for inspection. The examination did not reveal any pre-impact defect that would have prevented the engine from operating normally.
Pilot
The pilot held a Private Pilot Licence (Aeroplane) and was endorsed for single-engine aircraft below 5,700 kg maximum take-off weight (MTOW). He was 34 years of age and held a current Class 2 medical certificate with no special requirements.
The pilot had obtained his licence on 7 April 2000 and reportedly had accrued less than 100 hours flying experience. A precise figure could not be obtained as the pilot's logbook, which was recovered from the aircraft wreckage, had been almost destroyed by fire.
The pilot had begun his flying training some time previously, but the completion of his Private Pilot training was delayed. He subsequently completed his Private Pilot training with a Canberra-based flying training and charter operator. At the time of the accident, the pilot was purchasing both the Musketeer and the training and charter company. Between 5 January 2000 and 23 April 2000, the pilot completed 25 training flights, totalling 30.9 hours, of which 25.8 hours were dual and 5.1 hours were solo. The pilot passed his General Flying Proficiency Test on 7 April 2000 and subsequently completed eight navigation training flights totalling 16.9 hours dual and 5.0 hours solo.
An instructor assessed the pilot's flying skills as sound, but added that the pilot tended to be over-confident. Another instructor said that although the pilot's aircraft handling met the required standard, he tended to be casual and to chat during flight. He added that the pilot did not always concentrate sufficiently on the task in hand, and did not always prepare fully for cross-country flights.
A witness said that all four aircraft occupants had arrived at the pilot's home in Canberra, after driving from Brisbane in two vehicles, in the early hours of the morning on the day of the accident. En route, they had visited a private home at Umina on the NSW Central Coast, departing there at about 2130 hours Eastern Standard Time (EST), and had probably arrived in Canberra about 0130. The witness observed the pilot up and about at 0630 EST on the day of the accident.
Neither the autopsy nor the toxicology reports on the pilot revealed any medical condition that would have impaired his ability to operate the aircraft.
Weather
The weather conditions at the time of the accident were:
Surface wind: 035/04-06 kts (Max headwind component 0.5 kt, max crosswind component 6 kt)
Visibility: 40 km
Temperature: 25.3 degrees C
Dew point: 12.5 degrees C
QNH: 1014.0 hPa
Cloud: 2 octas cumulus, base 5,000 ft
These conditions produced a density altitude of 3,400 ft on the ground at the aerodrome. The aerodrome elevation is 1,888 ft above mean sea level (AMSL).
Aircraft weight and balance
Based on a fuel load of 115 L and weights of the aircraft occupants as determined by the autopsies, the aircraft gross weight at take-off was calculated as 2,375 lb. The maximum permitted gross weight for takeoff was 2,400 lb. The aircraft centre of gravity was near the middle of the permitted range.
Aircraft performance
According to performance charts, the aircraft was capable of take-off and climb from runway 30 with 15 degrees of flap selected, and climb at maximum gross weight under the prevailing environmental conditions. However, with a density altitude of 3,400 ft and the aircraft gross weight just below MTOW, the pilot would have needed to monitor take-off and climb performance closely.
Stall warning system
The aircraft was equipped with the normal stall-warning system: a vane mounted in the wing leading edge that moved upward, triggering an aural warning, when the wing's angle of attack approached the stalling angle.
Before departing on the aircraft's delivery flight to Canberra 14 days before the accident, the pilot who carried out the delivery flight tested the system on the ground and found it to operate when the vane was raised manually. The day following the delivery flight, the accident pilot carried out a flight carrying three passengers, one of whom reported that the warning system had operated briefly a couple of times on that flight.
Another pilot who had flown the aircraft on two occasions said that during the flare prior to touchdown, the aircraft had stalled and firmly contacted the ground. On neither occasion did he remember hearing the stall warning operate.
The serviceability of the stall-warning system on the day of the accident could not be determined due to impact and fire damage.
Possible effects of terrain
The 570 m (1,880 ft) elevation contour line passes through the middle of the aerodrome but higher terrain lies to the west, north-west and north. Along the extended runway centreline, the terrain rises to 630 m (2,060 ft). To the left and right of the extended centreline the terrain rises to 662 m (2,170 ft) and 840 m (2,760 ft) respectively.
Visual illusions can occur in flying and result from a pilot's incorrect interpretation of what is seen. A pilot's susceptibility to visual illusions will depend largely on the amount and nature of his/her flying experience, although other factors such as fatigue tend to increase susceptibility.
When flying visually, a pilot judges the aircraft's attitude by the relationship between the nose of the aircraft and the horizon. This is then crosschecked with the aircraft instruments to confirm the aircraft is performing as expected. The various phases of visual flying such as climbing, descending and turning are accomplished by adjusting engine power and aircraft attitude. However, a pilot also receives indications of attitude and performance from his/her senses which can be deceptive.
Gently rising terrain ahead of a low-flying aircraft can lead a pilot flying visually to misjudge the horizon, thinking that it is higher than its true position. If the pilot uses this false horizon as a pitch-attitude reference, the aircraft nose attitude will be higher than normal, resulting in a reduction in airspeed. If a pilot does not monitor the airspeed closely, or does not apply power to compensate for the steeper angle, the aircraft can slow, unnoticed, to its stall speed.
Rising terrain can also mislead a pilot into believing that the aircraft is not climbing at the required rate. If the pilot then selects a higher nose attitude without reference to performance instruments, and does not apply additional power, the airspeed will reduce.
The maximum altitude attained was about 300 ft above the aerodrome elevation. The accident site was located at the base of rising terrain. Looking directly ahead, the pilot would have observed terrain rising to an elevation slightly below the altitude at which the aircraft stalled. Either side of the aircraft's heading, the terrain was higher still. Although it cannot be confirmed, the pilot might have been misled by the rising terrain and raised the aircraft's nose above the normal climb attitude.
Possible distractions
As the aircraft was taxiing for takeoff, the Surface Movement Controller (SMC) transmitted the Musketeer's airways clearance to the pilot, which he read back confidently and correctly. Twenty-six seconds later, the SMC heard about 30 seconds of open microphone transmission, indicating that the transmitting station was experiencing problems with an aircraft seat. The SMC then called the transmitting station, informing it that its intercom was being transmitted on SMC frequency. Although the source of the transmissions could not be confirmed, the indications pointed to the Musketeer. Exactly 2 minutes later, the Aerodrome Controller (ADC) gave the Musketeer its takeoff clearance; in his readback, the pilot sounded unsure of himself and made a couple of errors.
As the aircraft was climbing after takeoff, the ADC passed traffic information to the pilot, informing him of an inbound helicopter in his 12 o'clock. The pilot acknowledged and replied that he was looking for traffic. That was the last radio transmission from the aircraft; about 30 seconds later, the aircraft impacted the ground.
