Accident Details
A private pilot was practicing a 180-degree power recovery autorotation in a helicopter equipped with a clockwise-rotating main rotor. The wind was from the right at three knots.
Sequence of Events
During the maneuver, the pilot experienced a higher-than-expected rate of descent while flaring at zero airspeed, attempting a power recovery to terminate at a skid height of approximately 15 feet above ground level. Suddenly and without warning, directional control was lost; the helicopter began to spin to the left (nose left). The pilot applied full right pedal, but it had no effect. The pilot attempted to keep the helicopter level while it was spinning, but it impacted on the left side of the taxiway.
Damage and Injuries
The helicopter sustained substantial damage. The left skid gear partially collapsed, and the airframe and tail boom buckled. During the impact sequence, the main rotor blades struck the tail boom, and both the main rotor blades and tail rotor blades struck the ground. There was no post-crash fire. The pilot received minor injuries.
Investigation
An on-scene investigation by an FAA maintenance inspector confirmed flight control continuity and found no apparent damage to the tail rotor drive belts.