Primary finding
Probable cause
The piece of wood/tree that contacted the main rotor blade during the low altitude tree-trimming flight.
Investigator assessment
Analysis narrative
The purpose of the helicopter flight was to trim trees using an external load aerial power saw. The pilot stated that as he was trimming the trees, he saw a 6 to 8 inch piece of wood/tree flying upward on the left side of the helicopter. He stated he felt a momentary vibration as the wood contacted one of the main rotor blades, then everything returned to “normal.” The pilot made a precautionary landing in a nearby field without further incident. The damage to the main rotor blade was substantial and required replacement of the blade.
Source record
Factual narrative
The purpose of the helicopter flight was to trim trees using an external load aerial power saw. The pilot stated that as he was trimming the trees, he saw a 6 to 8 inch piece of wood/tree flying upward on the left side of the helicopter. He stated he felt a momentary vibration as the wood contacted one of the main rotor blades, then everything returned to “normal.” The pilot made a precautionary landing in a nearby field without further incident. The damage to the main rotor blade was substantial and required replacement of the blade.