What happened
The incident occurred during a flight training maneuver involving an autorotation. The student pilot was executing the final phase of this procedure at approximately 50 feet above ground level (AGL). As the flare was initiated, the instructor pilot observed that the helicopter was not leveling properly. In response to this instability, the instructor took control of the aircraft.
Despite the intervention, the helicopter settled tail-low onto soft ground. This contact resulted in the separation of the tail rotor from the main fuselage. Following the initial impact, the helicopter turned and subsequently settled to the ground again, coming to rest on its right side.
The investigation
The physical examination of the aircraft revealed significant structural damage consistent with the described sequence of events. The primary mechanical failure identified was the separation of the tail rotor assembly from the helicopter. The nature of the impact suggests that the soft ground conditions contributed to the severity of the contact during the tail-low settlement.
Findings
The accident sequence highlights the critical importance of maintaining proper attitude control during the flare phase of an autorotation. The failure of the helicopter to level off at low altitude necessitated immediate control intervention by the instructor. The subsequent ground contact with the tail section led directly to the loss of the tail rotor, which compromised the aircraft's stability and resulted in a rollover.
Safety message
Instructors must remain vigilant during student maneuvers that involve low-altitude energy management. Proper flare technique is essential to prevent tail-low attitudes that can lead to ground contact with vulnerable components such as the tail rotor.