What happened
During a flight operating at low altitude, an aircraft experienced a sudden loss of engine power. The flight was occurring at approximately 1,900 ft AMSL over a property, with the aircraft flying below 200 ft AGL. At the time of the engine failure, the aircraft was carrying approximately 750 L of chemical load which had not been dumped.
Following the loss of power, the pilot attempted to navigate the aircraft toward a suitable landing site. The surrounding area, characterized by orchards, residential houses, and powerlines, presented significant challenges for an emergency descent. The terrain was further complicated by uneven ground and the presence of creeks. The aircraft eventually came to rest approximately 2.5 km from the point where the engine failure first occurred. The wind was a light westerly at 2 kt, providing a slight tailwind during the descent.
The investigation
Investigators examined the aircraft's maintenance history and found it had been approximately 91.9 hours since its last periodic maintenance inspection. A pre-flight inspection conducted by the pilot earlier that morning had shown normal oil levels and no immediate issues. During the flight, engine instruments indicated normal temperature and pressure levels immediately before the failure occurred. Additionally, a chip detector installed in the engine did not activate during the event.
Findings
- A post-accident inspection identified a cracked cylinder (specifically the number seven cylinder) as the source of the power loss.
- The presence of 750 L of chemical load on board increased the aircraft's weight during the emergency.
- The low altitude of the flight (below 200 ft AGL) and the complex terrain, including powerlines and orchards, significantly restricted the available options for a safe forced landing.