Helicopter Strikes Tailboom During Hovering Autorotation Training

Incident Overview

A flight instructor was providing hovering autorotation training to a private pilot in a helicopter. The instructor reported that he reduced the throttle to initiate the maneuver. The private pilot then raised the collective too soon, which resulted in the helicopter climbing. As rotor inertia decayed, the helicopter struck the ground. Following the ground strike, a main rotor blade struck the tailboom.

Damage Assessment

The helicopter sustained substantial damage to the tail rotor drive shaft. According to the pilot, there were no preaccident mechanical malfunctions or failures that would have precluded normal operation.

Training Context

The maneuver being practiced was a hovering autorotation, a training exercise typically used to practice engine failure recovery at low altitude. The flight instructor was present to guide the private pilot through the procedure.