What happened
During a low-level cruise flight, the pilot of VH-KJJ, a Robinson R44 (implied by context of KJJ registration/type), experienced a sudden loss of engine power. This failure occurred shortly after the aircraft had been refuelled using a local drum-based fuel supply. The loss of power was caused by a significant amount of water entering the helicopter's fuel system, which interrupted the necessary fuel flow to the engine.
In response to the engine failure, the pilot initiated an autorotation procedure. The pilot attempted to perform a forced landing within an area characterized by heavy timber. During the landing sequence, the aircraft sustained impact damage. The nature of the damage suggests the helicopter was descending at a high rate at the moment of touchdown, likely because the main rotor RPM had decreased significantly during the final stages of the autorotation.
The investigation
The investigation focused on the circumstances that led to the fuel contamination and the subsequent mechanics of the autorotation. Investigators examined the fuel-handling processes used during the recent refuelling event and analyzed the engine's performance following the introduction of water into the system. The assessment also looked at the flight dynamics during the emergency descent to understand why the rotor RPM was low at the time of impact.
Findings
- Water contamination in the fuel system interrupted the flow of fuel to the engine.
- The engine failure occurred during low-level cruise flight following refuelling from a drum.
- The aircraft sustained impact damage consistent with a high rate of descent.
- Low main rotor RPM was a likely factor in the severity of the impact during the forced landing.