Incident Overview
A helicopter pilot reported that, after completing a high reconnaissance, the helicopter was descended to approximately 30 feet above power lines for a powerline inspection, flying at about 30-35 knots. During the patrol, the crew climbed over an identified crossing line and then descended back down.
Collision Sequence
While descending, a passenger spotted a previously unseen power line in the flight path. The pilot responded by pulling hard aft cyclic with right pedal, but the main rotor blades struck the power line. Following the impact, the helicopter acquired a vibration in the main rotor system.
Landing and Damage
The pilot was able to land the helicopter without further incident. The helicopter sustained substantial damage to the main rotor blades.
Mechanical Status
The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.