Primary finding
Probable cause
The pilot’s failure to see and avoid transmission wires while maneuvering at a low altitude.
Investigator assessment
Analysis narrative
The helicopter pilot reported that, while maneuvering at a low altitude for an agricultural application flight, he began flying along the north side of the intended spraying field. He added that he was paying attention to the trees along the field to maintain adequate clearance. He further added that the main rotor blades struck transmission wires and that he then heard a "high pitch sound" coming from the engine and the rpm decrease. The nose pitched up, and the helicopter impacted the ground and rolled onto its right side. The helicopter sustained substantial damage to the fuselage and empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot reported that he had noticed the transmission wires earlier in flight but that he later forgot where they were located.
Source record
Factual narrative
The helicopter pilot reported that while maneuvering at a low altitude for an agricultural application flight he began flying along the north side of the intended spraying field. He added that he was paying attention to the trees along the field to maintain adequate clearance. He further added that the main rotor blades struck transmission line wires, and then he heard a "high pitch sound that came from the engine" and the rpm decreased. The nose pitched up and the helicopter impacted the ground and rolled onto its right side. The helicopter sustained substantial damage to the fuselage and empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot reported that he had noticed the transmission line wires earlier in flight, but later had forgotten where they were located.