Jandakot

The aircraft took off from runway 24 right (24R) at Jandakot Airport, WA. One pilot and five passengers were on board the aircraft. The flight was being conducted in the aerial work category, under the instrument flight rules. Shortly after the aircraft became airborne, while still over the runway, the pilot recognized symptoms that he associated with a failure of the right engine and elected to continue the takeoff. The pilot retracted the landing gear, selected the wing flaps to the up position and feathered the propeller of the right engine. The pilot later reported that he was concerned about clearing a residential area and obstructions along the flight path ahead, including high-voltage powerlines crossing the aircraft’s flight path 2,400 m beyond the runway. The aircraft was approximately 450 m beyond the upwind threshold of runway 24R when the pilot initiated a series of left turns. Analysis of radar records indicated that during the turns, the airspeed of the aircraft reduced significantly below the airspeed required for optimum single-engine performance. The pilot transmitted to the aerodrome controller that he was returning for a landing and indicated an intention to land on runway 30. However, the airspeed decayed during the subsequent manoeuvring such that he was unable to safely complete the approach to that runway. The pilot was unable to maintain altitude and the aircraft descended into an area of scrub-type terrain, moderately populated with trees. During the impact sequence at about 1537, the outboard portion of the left wing collided with a tree trunk and was sheared off. A significant quantity of fuel was spilled from the wing’s fuel tank and ignited. An intense postimpact fire broke out in the vicinity of the wreckage and destroyed the aircraft. Four passengers and the pilot vacated the aircraft, but sustained serious burns in the process. One of those passengers died from those injuries 85 days after the accident. A fifth passenger did not survive the post-impact fire.

The flight was planned to check the onboard survey equipment. After departing Jandakot the aircraft operated to the south of the airfield for about 80 minutes before the pilot advised that he would be extending his operation to the east over the Darling Ranges. The aircraft was then sighted, by several witnesses, over the foothills heading in an easterly direction. These witnesses reported that the engines were not operating normally. A short time later, the aircraft was observed to pass over the dam wall at an altitude of about 25 feet and head down a valley in a northerly direction before disappearing from sight. An inspection of the wreckage indicated that the aircraft had collided with two 30 metre high trees, in a nose high attitude at a low forward airspeed, before falling to the ground below the trees. At impact neither engine was delivering power. The fuel system, which was found to be relatively intact, contained only nine litres of fuel.

The aircraft was flown from Jandakot to Perth at approximately 08:00 hours on 3.5.81. However, the engineer who had agreed to meet the pilot sent a message that he could not attend. At times during the morning, persons observed the aircraft parked at the airport. The engine cowls had been removed and the pilot was seen to be working in the area of the propeller governors. At about 11:00 hours, the pilot started the aircraft's engines, taxied to a clear area and carried out a series of checks" at high power. Then, at 11:09 hours, he contacted Perth Surface Movement Control by radio and requested clearance for an air test at Flight Level 200. This was approved and the aircraft was instructed to taxi to Runway 20. After take-off, the aircraft turned right and tracked to the west on the 270 radial of the VHF omni-directional radio range (VOR), in accordance with departure instructions give n by Perth Tower. When asked for his intentions, the pilot advised that he wished to continue tracking to the west until further notice. Weather conditions in the Perth area were fine; there was no cloud and the surface wind was a light southwesterly. The aircraft as it climbed out appeared to be operating normally , except for a thin smoke trail which was observed coming from the right engine. At 11:19 hours, the pilot advised that his test was completed. He reported he was at 7,000 feet and 10 miles from the airport by distance measuring equipment (DME). During the next five minutes there were a series of routine exchanges between VH-CCW and Perth Tower as the aircraft was cleared to track visually, north of Perth city, to a right base position for Runway 20. During these exchanges the pilot did not indicate that any abnormality or emergency existed and his voice sounded normal. At 11:24 hours, he reported at right base and was cleared to land. The final transmission received from the aircraft was the usual acknowledgement of the landing clearance. The right base position for Runway 20 is over the suburb of Bassendean and local residents are used to aircraft overflying. However, attention was drawn to VH-CCW as it was lower than normal traffic, the engine noise was louder and smoke was trailing from its right engine. Otherwise, it appeared to be operating normally; both propellers were rotating and the landing gear was reported to be retracted. The aircraft had commenced an apparently normal right base turn when it suddenly rolled inverted. The nose of the aircraft may have pitched up just before the sudden roll. The aircraft then began to rotate and rapidly descend. At some stage, it rolled back to the normal upright attitude. After about two turns, the rotation stopped and the aircraft dropped vertically to the ground in the backyard of a private house. The left wing and tailplane struck the roof of the house just prior to ground impact. An intense fire immediately broke out and consumed most of the wreckage. Subsequent examination of the wreckage found no evidence of pre-existing defects or malfunctions, apart from loose attachment nuts on the left side of the propeller governor fitted to the right engine. Oil had leaked from the governor at this position, covering the engine and causing the smoke trail observed by witnesses. Internal inspection of the right engine established that all bearing surfaces were oil-wetted, but it could not be determined how much oil remained in the engine at the time of ground impact as any residual oil had leaked and been consumed by fire. Both engines had been operating at impact. The right engine was at a low power setting, probably idle. The left engine was at a higher power, although the exact power setting could not be determined. The left propeller was at a blade angle consistent with higher power output. The right propeller was at a blade angle outside the normal operating range but consistent with the propeller moving towards the feather position, either as a result of pilot selection or exhaustion of the engine oil supply. It was not possible to determine whether or not the pilot had initiated feathering. The stability augmentation system servo was at the maximum, elevator-down spring tension position. The automatic system would drive the servo to this position when the aircraft was flown at low airspeed. The elevator trim was set at 10 degrees nose-up, also consistent with low-speed flight. The rudder trim was at the full-left rudder position, indicating that the pilot had been operating the aircraft for some time with high power on the left engine and the right engine at a low power setting. The flaps were half extended and the landing gear was down at ground impact. Post-mortem examination found that the pilot had extensive coronary artery disease, such that he may have suffered a sudden incapacitating attack or death. Alternatively, he may have experienced severe chest pain, causing him to unintentionally apply coarse movements to the aircraft controls. The pilot had completed regular medical examinations for the renewal of his pilot's licence, but his condition had not been detected.