Accident Overview
A helicopter pilot was performing a practice autorotation with the intent to terminate the maneuver to a hover. During the flare phase, the pilot allowed the rotor RPM to decay. Subsequently, the pilot increased collective and added power using the throttle. The helicopter's nose yawed to the right, and simultaneously the fuselage rolled to the left.
Sequence of Events
The pilot applied left pedal in response to the yaw and roll, but the left skid struck rising terrain. This impact caused the helicopter to enter a dynamic rollover. The helicopter sustained substantial damage to the main rotor drive system and the tail rotor drive system.
Pilot Statement
The pilot reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.