What happened
The incident occurred during a landing maneuver. The pilot was operating the aircraft in a hover configuration when an aft movement was initiated. During this phase of flight, the tail boom stinger made contact with the ground. This impact resulted in the separation of the tail rotor and its associated gearbox from the main structure of the helicopter.
Following the structural failure, the pilot lost directional control of the aircraft. The loss of control led to a hard landing. There is no information provided regarding injuries or fatalities in the source text.
The investigation
A post-crash examination of the helicopter was conducted to determine the condition of the airframe and systems prior to the impact. The inspection revealed no evidence of mechanical failure or malfunction within the helicopter's systems before the crash occurred.
Findings
The primary factor contributing to the accident was the pilot's failure to maintain adequate tail boom stinger ground clearance while hovering to land. This operational error directly led to the stinger contacting the ground, which caused the subsequent separation of the tail rotor and gearbox and the loss of directional control.