Primary finding
Probable cause
The pilot’s failure to maintain clearance from a stationary helicopter during landing. Contributing to the accident was the ground crew’s failure to ensure that the helicopter would clear the stationary helicopter.
Investigator assessment
Analysis narrative
The pilot reported that, while hovering the helicopter to park between three stationary helicopters, the ground crew gave him the signal for a 180° "pedal turn." As the helicopter was about to touch down, he felt a shudder in the airframe. He then immediately rolled the throttle closed and completed an emergency shutdown. Postaccident examination revealed that the tail rotor blades struck the main blades of a stationary helicopter, which likely caused the shudder felt by the pilot. The helicopter sustained substantial damage to the tail rotor and main rotor systems. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Source record
Factual narrative
The pilot reported that, while hovering the helicopter to park between three stationary helicopters, he had been given the signal for a 180 degree "pedal turn" by the ground crew. As the helicopter was about to touchdown, he felt a shudder in the airframe, immediately rolled the throttle closed, and completed an emergency shutdown. A post-accident examination revealed that the tail rotor blades struck the main blades of a stationary helicopter. The helicopter sustained substantial damage to the tail rotor and main rotor systems. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.