Primary finding
Probable cause
The pilot under instruction's failure to maintain directional control and the flight instructor's delayed remedial action.
Investigator assessment
Analysis narrative
The flight instructor in the skid-equipped helicopter reported that the purpose of the flight was to conduct an aircraft transition flight. The pilot under instruction performed a touchdown autorotation on the asphalt runway. The helicopter touched down in a level attitude just right of the centerline and then slid on its skids off the right side of the runway into grass. The helicopter spun right and rolled onto its left side. The helicopter sustained substantial damage to the main and tail rotor drive systems. Both pilots reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
Source record
Factual narrative
The flight instructor in the skid-equipped helicopter reported that the purpose of the flight was to conduct an aircraft transition flight. The pilot under instruction performed a touchdown autorotation on the asphalt runway. The helicopter touched down in a level attitude and just to the right of the centerline sliding to the right on its skids. Subsequently, the helicopter slid off the right side of the runway into the grass. The helicopter spun to the right and rolled onto its left side. The helicopter sustained substantial damage to the main and tail rotor drive system. Both pilot's reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.