Engine Power Loss
There was a discrepancy between the property owner's recollection of the pilot's statements soon after the accident and the pilot's subsequent recollection regarding whether the engine initially lost some power after take-off before stopping completely. However, damage to the propeller was consistent with the engine having stopped prior to the point of impact. The fuel and engine systems of VH-YGY comprised numerous components, and a failure of one or more of these components could have contributed to the engine failing in‑flight. The Australian Transport Safety Bureau (ATSB) was unable to determine any reasons for this as the post‑impact fire had damaged or destroyed most of these systems. Of the components that remained, no overt defects were identified. The aircraft had reportedly been difficult to start in the past, but it is not known if the pilot had any issues starting the engine on the day of the accident.
The fuel pressure regulator had been replaced 3 days prior to the accident, and the ATSB considered the possibility of a defect associated with the component’s serviceability or an error in its fitment. The fuel pressure regulator or any remnants of it were not identified in the aircraft wreckage, and it is likely that it had been destroyed during the post-impact fire. Therefore, no conclusions regarding its serviceability or security could be drawn.
Forced Landing
Following a complete engine failure, a forced landing is inevitable, whereas in a partial power loss, pilots are faced with making a difficult decision whether to continue flight or to conduct an immediate forced landing. The pilot decided to turn back to the secondary runway of Old Station ALA, as they likely believed this was achievable, based on the circumstances at the time. After they assessed that this was no longer possible and with the onset of the deep gully at the threshold of the runway, the pilot was compelled to make an immediate forced landing. The forces on the aircraft’s structure because of its rate of descent during the forced landing buckled the wing/fuselage structure, liberated both main landing gear axle, brake and wheel assemblies, collapsed the landing gear, and caused one or both wing fuel tanks to be breached, which intensified the post-impact fire.
The effectiveness of the pilot’s attempt to reduce the aircraft’s energy immediately ahead of the impact could not be determined. Lowering the flaps could have slowed the aircraft for landing, potentially lessening impact damage, although it was not determined if the pilot had time to do so.
Protective Clothing
There are no regulatory requirements for the selection of clothing on private or other flights. However, selection of clothing that is more flame resistant and with more coverage can reduce the severity of burns and offer protection during extrication from a crashed aircraft. Fibres such as cotton, flax, nylon, and polyester burn more easily than fibres such as wool and aramids which are more flame‑resistant. The shorts and t-shirt worn by the pilot on the day of the accident would have offered less protection than a long sleeve shirt and trousers, however it was not determined whether this contributed to the severity of their injuries. While personal preference and comfort are obvious factors in the selection of clothing when flying, consideration should be given to the clothing’s fire resistance and coverage.