Primary finding
Probable cause
The instructor pilot’s inadequate supervision of the pilot receiving instruction, which resulted in a hard landing, and substantial damage to the tail boom.
Investigator assessment
Analysis narrative
The pilot receiving instruction and instructor pilot completed a Part 135 recurrent training flight, which included, in part, autorotations, hovering autorotations, and sloping ground landings. A post-flight inspection revealed substantial damage to the tail boom that was consistent with a hard landing. The pilots reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.