Accident Sequence
Shortly after takeoff during cruise flight at 60 knots while over trees at an altitude of no less than 600 feet above ground level, the helicopter's engine experienced a total loss of power. The pilot initiated a descent for an autorotative landing. During the descent, the pilot reportedly pulled the caution circuit breaker, though a passenger who is a helicopter-rated pilot reported that he did not observe this action. At an altitude of 50 feet, the pilot flared, but the pilot-rated passenger stated that he did not feel the initial collective pull. The pilot later stated that he misjudged his landing area distance and, while attempting to clear trees below, intentionally bled the main rotor rpm. The helicopter landed hard in a clearing.
Post-Crash Examination
Post-crash examination of the cockpit revealed that the caution circuit breaker was pulled. Fuel quantity was sufficient to sustain engine operation, and no contaminants were found. No discrepancies were noted with the fuel control or power turbine governor. The engine was removed from the helicopter and placed in a test cell, where it was operated and found to produce less than full rated power. Disassembly of the engine revealed minor discrepancies. The fuel control and power turbine governor were bench tested, which revealed no mechanical failure or malfunction.
Investigation Conclusion
No determination could be made as to the reason for the total loss of engine power.