Robinson Helicopter Company R44 II N74666 accident near The Dalles, Oregon

Probable cause

The pilot's failure to see and avoid wires while maneuvering at a low-altitude, which resulted in the main rotor blades striking the wires.

NTSB analysis

The pilot reported that he was maneuvering at a low altitude over a cherry orchard as part of a drying operation. The light was low due to cloudy weather conditions and he did not see corroded copper wires that were adjacent to the orchard. He noticed a pole that had shiny wires on one side, which gave him the illusion that that was the end of the power line, since he could not see the other connected pole that was obscured by trees. The main rotor blades were substantially damaged when they contacted the wire. The pilot reported no pre impact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR13CA354 for the full record.