Primary finding
Probable cause
The pilot's improper decision to land downwind from unsecured debris, which resulted in the helicopter’s main rotor disk ingesting foreign objects.
Investigator assessment
Analysis narrative
The pilot reported that he landed the helicopter facing south and about 90 ft from where ground personnel were unhooking super sacks filled with gravel. When the skids touched down, the pilot reduced the collective and then saw an empty super sack about 15 ft away, which subsequently struck the main rotor toward the outboard portion of the blade. The super sack was ingested by the advancing side of the main rotor disk. The pilot rolled off the throttle and shut down the engine. The helicopter sustained substantial damage to the main rotor blades. 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 helicopter pilot reported that, he landed the helicopter facing south and about 30 yards from the empty gravel carrying super sacks. When the skids touched down, the pilot reduced the collective and saw a super sack about 15ft away and coming at the helicopter. The super sack was ingested by the advancing side of the main rotor disk. The pilot rolled off throttle and shut down the engine. The helicopter sustained substantial damage to the main rotor blades. The pilot reported that the wind at the accident site was from the southwest about 15 knots. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.