Accident Overview
A private pilot was conducting an out-of-ground-effect (OGE) hover over his property while a passenger took photographs. The helicopter, equipped with a reciprocating engine, was approximately 200 feet above ground level (agl) and experienced a tailwind of about 5 to 10 knots. During the hover, the tail of the helicopter began to oscillate left and right. This oscillation was followed by a nose-down descent, resulting in the helicopter impacting a building and the ground. The source notes that although the tail oscillated, the helicopter did not spin.
Aircraft and Pilot Information
The helicopter's weight at the time of the accident was approximately 2,570 lbs, which was under the maximum gross weight of 2,850 lbs. The pilot held a private pilot certificate. No specific aircraft type, registration, or engine details beyond "reciprocating engine" were provided.
Performance Considerations
A review of the rotorcraft flight manual (RFM) indicated that the helicopter was operating at the edge of its performance envelope. Under the given conditions, the helicopter could hover OGE at a weight of 2,500 lbs but not at the maximum gross weight of 2,850 lbs. Furthermore, the RFM contained no performance data for OGE hovering in a tailwind. The source suggests that a tailwind may have required additional tail rotor thrust to maintain directional control, which would reduce the power available to the main rotor for lift. This performance limitation could have played a role in the accident sequence.
Wreckage Examination
Examination of the wreckage revealed no pre-impact mechanical malfunctions. The helicopter's systems and components appeared to be functioning normally prior to impact. The accident occurred while the helicopter was in a low-speed, high-power flight regime typical of hovering maneuvers.