What happened
The accident occurred during the initial climb phase of flight. Shortly after liftoff, the helicopter experienced a complete loss of engine power while climbing to an altitude of approximately 20 feet above the ground. The pilot immediately initiated an autorotative landing procedure to manage the emergency descent. Upon touchdown, the aircraft slid down a nearby river bank, which caused it to roll over and subsequently catch fire.
The investigation
Post-accident examination of the helicopter revealed that the fuel tanks had not ruptured during the impact or rollover. Despite the fire damage, both tanks remained intact and still contained residual fuel. Investigators drained samples from each tank for analysis. Laboratory testing confirmed the presence of water in both fuel sources. A significant amount of water was specifically identified within the left fuel tank, indicating a serious contamination issue.
Findings
The primary factor contributing to the accident was the ingestion of contaminated fuel. The presence of considerable water in the fuel system led to engine failure during a critical phase of flight where recovery options were limited. The subsequent loss of power necessitated an autorotation, which unfortunately resulted in ground impact damage and fire due to the terrain.
Safety message
Regular inspection and draining of fuel tanks are essential to prevent water accumulation. Pilots must ensure that fuel systems are free from contamination before flight operations to avoid potential engine failures.