What happened
The incident occurred while a pilot assigned to a law enforcement helicopter unit was conducting a training exercise. The specific maneuver involved performing a practice autorotative landing intended to result in a touchdown. During the final phase of this approach, known as the landing flare, the aircraft's tail stinger made contact with the ground surface.
This initial impact caused the helicopter to land heavily. The force of the hard landing resulted in significant structural failure. Specifically, the main rotor blades flexed downward due to the impact forces. This downward flexion caused the rotor blades to sever the tail boom completely, leading to substantial damage to the aircraft's rear structure.
The investigation
The supervisor of the law enforcement helicopter unit provided a report detailing the sequence of events. The account confirms that the pilot was engaged in a practice autorotative landing to touchdown at the time of the accident. The critical failure point was identified as the tail stinger contacting the ground during the flare, which subsequently led to the main rotor blades flexing downward and severing the tail boom.
Findings
The primary factor contributing to the damage was the contact between the tail stinger and the ground during the landing flare. This contact initiated a hard landing condition. The resulting mechanical stress caused the main rotor blades to flex downward, which directly resulted in the severing of the tail boom. No other contributing factors were identified in the available narrative.