Robinson Helicopter Company R44 II N31136 accident near Washington, Wisconsin

Probable cause

The pilot’s failure to maintain lateral control during a hover and improper recovery action after the helicopter contacted the ground, which resulted in a dynamic rollover sequence and an impact with terrain.

NTSB analysis

The pilot reported that while moving over a slight incline at a hover in preparation for the takeoff, a gust of wind caused the helicopter to weathervane, inadvertently contact the ground, and initiate a rolling motion. Although the proper response was to lower the collective in this situation, the pilot’s immediate reaction was to increase the collective, which exacerbated the dynamic rollover sequence. The helicopter continued the rolling motion and came to rest on its right side. The helicopter sustained substantial damage to the main rotor system, the fuselage, and the tail rotor system. The pilot reported there were no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for CEN21LA021 for the full record.