Primary finding
Probable cause
The flight instructor's inadequate supervision and delayed remedial action during a practice autorotation, which resulted in a tail rotor strike.
Investigator assessment
Analysis narrative
The pilot receiving instruction was performing a practice 180-degree autorotation. Just prior to touchdown, the flight instructor perceived an abrupt loss in altitude, followed by a hard landing and tail rotor strike, which substantially damaged the tail rotor. The flight instructor reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
Source record
Factual narrative
The pilot receiving instruction was performing a practice 180-degree autorotation. Just prior to touchdown, the flight instructor perceived an abrupt loss in altitude, followed by a hard landing and tail rotor strike, which substantially damaged the tail rotor. The flight instructor reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.