Incident Overview
A helicopter pilot reported that, after landing on an elevated helicopter deck and reducing rotor RPM, he signaled for the brush cutting ground crew leader to approach the helicopter to collect additional chainsaw bars that were being dropped off. The crew leader indicated that two of the three chainsaw bars were not the correct bars needed for the operation. In response, the crew leader threw one of the incorrect bars away from the helicopter. The thrown bar subsequently impacted a main rotor blade, resulting in substantial damage to the blade.
Background and Briefing
The pilot stated that the brush cutting crew had been briefed before the start of operations on gear security, rotor awareness, and safe practices for working around the helicopter. Despite these precautions, the crew leader admitted to a lapse in judgment brought on by stress and frustration at the time of the incident.
Mechanical Condition
The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The damage was solely the result of the foreign object strike to the rotor blade.
Conclusion
The accident was caused by a ground crew member throwing a chainsaw bar into the path of the helicopter's main rotor, leading to severe blade damage. No additional contributing factors were identified in the pilot's report.