Incident Overview
During a sightseeing flight through a canyon, an aircraft carrying passengers collided with powerlines. The wires, estimated to be 1,700 feet long and made of half-inch-diameter aluminum, were unmarked; their height above ground level was not determined. The pilot later stated that he did not see the wires, reportedly commenting, "How did that happen."
Camera Equipment and Control Interference
One passenger was filming the scenery during the flight. The pilot subsequently suggested that a camera battery pack may have interfered with the collective control while he was attempting to avoid the powerlines. The passenger, however, reported that all extra photographic equipment was stored in a bag in the rear compartment. After the accident, some camera equipment was found outside the aircraft. Rescue personnel had moved that equipment inside during the recovery operation.
Investigators later placed the battery pack near the collective control to attempt to replicate the alleged interference. They determined that the only configuration that could cause interference was with the pack positioned on its edge and fully aft, adjacent to the collective control pivot point.
Subsequent Findings
The pilot's remark indicated that he was unaware of the powerlines until the collision. The exact circumstances regarding the positioning of the camera equipment and its potential impact on flight controls were examined based on the pilot's account and physical testing.