What happened
During a night instructional flight, the crew was performing a practice autorotation following a simulated engine failure during the takeoff phase. During the maneuver, the pilot entered the procedure at an airspeed below the recommended 60 knots. As a result, a high rate of sink developed during the landing flare that the student pilot was unable to arrest.
Upon touchdown, the toe of the right landing gear skid sank into the ground, causing the helicopter to execute a 90-degree turn. During this movement, the main rotor blades made contact with the tailboom, effectively severing it from the aircraft. The occupants were not injured in the accident.
Findings
The investigation found no evidence of mechanical malfunction or failure in the aircraft. The primary issue was the airspeed at which the maneuver was initiated, which prevented a proper landing flare and led to the uncontrolled descent rate and subsequent ground contact that caused the tailboom strike.