What happened
During a flight demonstration, a flight instructor was performing a simulated autorotation with a turn for a rated private pilot. The maneuver included a flare initiated at approximately 50 feet above ground level (AGL). As the instructor applied initial collective pitch at an altitude of 15 to 20 feet AGL, both crewmembers heard a noise described as a "pop."
As the instructor increased collective pitch to terminate the autorotation and transition into a hover, the tail rotor blades and the tail skid collided with the ground. This impact caused the helicopter to begin spinning to the right. The instructor responded by applying left anti-torque pedal and rolling the throttle back to the idle stop. Following the impact, the helicopter came to a complete stop upright on its skids. Both crewmembers were not injured.
The investigation
An examination of the helicopter was conducted by an authorized repair station. The inspection determined that all observed damage was the result of the ground impact. Investigators found no evidence of any mechanical failure or malfunction involving the tailrotor gearbox or any associated components prior to the crash.