Robinson Helicopter Co R66 N23UP accident near Tukwila, Washington

Probable cause

The pilot’s failure to maintain yaw control during a takeoff to a hover in a gusting crosswind, which resulted in a loss of directional control and a subsequent hard landing.

NTSB analysis

The pilot and pilot-rated passenger boarded the helicopter for a local flight and were cleared by air traffic control to depart south. The pilot lifted the helicopter off the ramp and began to hover taxi east toward the taxiway with a left gusting crosswind. Surveillance video footage of the takeoff showed that shortly after lifting off, the helicopter yawed left about 90° while drifting east towards the taxiway. The helicopter continued to drift and then climbed in a slight nose up attitude. About 50 feet above ground level, the nose pitched down sharply, and it began a steep descent to the left. The helicopter pitched up to about level attitude and then landed hard on its skids. Subsequently, the helicopter bounced and climbed to the west out of the surveillance camera’s view.

According to the pilot, when the helicopter lifted off the pad and did not respond to torque pedal inputs as expected, he transferred the helicopter’s controls to the pilot rated passenger. According to the pilot-rated passenger, he did not assume control of the helicopter until shortly before the helicopter impacted the ramp. After impact with the ramp and bounced, the pilot-rated passenger added power to climb over nearby powerlines and landed the helicopter without further incident.

A post-accident inspection of the helicopter revealed it sustained substantial damage to the fuselage and tailboom. Additionally, a visual examination of the helicopter’s flight controls did not reveal any pre-impact anomalies. The pilot-rated passenger reported he did not observe any mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The airport’s automated weather observation station reported that, about the time of the accident, the wind was from 300° at 10 knots, gusting to 16 knots.

Text from the NTSB. Open the NTSB docket for WPR25LA199 for the full record.