Incident Overview
The pilot initiated a practice autorotation from approximately 600 ft above ground level. The airspeed was about 55 knots during the maneuver, with low main rotor rpm attributed to a low gross weight. In an effort to increase rotor rpm, a moderate flare was executed, which reduced the airspeed to 40 knots. However, the subsequent application of collective pitch did not arrest the descent rate.
Sequence of Events
As the helicopter continued its descent, the tail rotor struck the ground. Upon impact, approximately 6 inches of one tail rotor tip broke off, resulting in increased vibration. The pilot attempted to land the helicopter, but the drive to the tail rotor ceased to respond. Consequently, the helicopter yawed to the right. The left skid then struck the ground and collapsed. During the event, the mast assembly was projected through the canopy bubble.
Damage
The helicopter sustained damage including a broken tail rotor tip, a collapsed left skid, and the mast assembly penetrating the canopy.