Primary finding
Probable cause
The pilot's failure to maintain adequate separation from power lines, which resulted in a loss of helicopter control.
Investigator assessment
Analysis narrative
The pilot of the helicopter reported that, while maneuvering low around power lines during an agricultural spray, he "pulled up," and the right spray boom contacted a power line. He added that the "fuselage pitched forward and the main rotor blade cut the tail boom off just aft of the horizontal stabilizer." Subsequently, the helicopter began to rapidly spin, and after one or two rotations, the pilot "closed the throttle which stopped the rotation" and "cushioned the impact." The fuselage and tailboom sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
Source record
Factual narrative
The pilot of the helicopter reported that while maneuvering low around power lines during an agricultural spray, he "pulled up" and the right spray boom contacted a power line. He added that, the "fuselage pitched forward and the main rotor blade cut the tail boom off just aft of the horizontal stabilizer." Subsequently, the helicopter began to rapidly spin, and after 1 or 2 rotations, the pilot "closed the throttle which stopped the rotation" and "cushioned the impact." The fuselage and tail boom sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.