Incident Overview
A commercial certificated helicopter pilot was engaged in external load operations to support seismic activities. The helicopter, equipped with high skids, landed in a confined area with knee- to waist-level brush to pick up a passenger. The pilot remained onboard while the passenger boarded.
Sequence of Events
According to the pilot's report, as the passenger climbed into the helicopter, he unknowingly dragged a seismic cable over the toe of the left skid. When the pilot lifted the helicopter into a hover, the cable slid aft and became entangled in the helicopter's external load mirror. The cable severed the mirror from the helicopter, and the mirror was propelled upward into the main rotor blades. After striking the rotor, the mirror then impacted the vertical stabilizer.
Damage Assessment
A postaccident examination of the rotor system revealed that one rotor blade sustained a dent on its underside. The director of operations stated that the damaged blade was beyond allowable repair limits and required replacement.
Operational Context
The operation involved external load work in support of seismic surveys, requiring the pilot to land in a confined area with vegetation. The pilot did not exit the helicopter during the passenger pickup.