Robinson Helicopter Co R66 N660TN accident near Knoxville, Tennessee

Probable cause

The pilot’s failure to maintain directional control of the helicopter, which resulted in rear portion of the right skid contacting the ground and a subsequent dynamic rollover.

NTSB analysis

The pilot performed a preflight inspection of the helicopter, which was positioned in the yard of a residence on a slight incline. After starting the engine, and completing the checklist, he lifted to a hover at 6 ft. The helicopter then began to rotate in a counterclockwise direction and the helicopter’s nose pitched up. The rear portion of the right skid contacted the ground and the helicopter to rolled onto its right side. The helicopter’s main rotor, fuselage, and tailboom were substantially damaged. A posaccident examination of the helicopter revealed no evidence of any preimpact mechanical failures or malfunctions of the helicopter that would have precluded normal operation. Given this information, it is likely that the pilot failed to maintain directional control of the helicopter while transitioning into the hover, and the helicopter experienced a dynamic rollover when the right rear skid contacted the sloped ground.

Text from the NTSB. Open the NTSB docket for ERA21LA121 for the full record.