Helicopter Accident During Rope and Wire Stringing Operation (N30TV)

Operational Context and Crew Configuration The helicopter was being used to string rope and wires. The chief pilot occupied the left front seat, the copilot occupied the right front seat, and two observers were seated behind the pilots on either side. The copilot was on the controls, while the right observer was providing suggested flight directions. ## Accident Sequence Witnesses observed the helicopter approach a 150-foot-tall pole with a workman at the top. The workman was to connect a rope to a 17-foot line from the helicopter, which had 600 pounds of weights attached. The foreman in charge of ground operations was observing on the ground between his vehicle and the pole. He was not in radio contact with the pilots, although the vehicle was radio equipped. The wind was from 110 degrees at 9 knots, gusting to 19 knots. The helicopter came to a high hover over the pole, and the workman attempted to attach the rope. Witnesses said the helicopter descended as it drifted left and forward of the pole and workman, then it began to back up and climb. The rotor blades struck the pole and workman. The helicopter then rolled right, descended, and impacted the ground on its right side. ## Equipment and Communication The hook system that was normally used for this type of operation was on another helicopter and was not available for this mission. Instead, a 'U' shaped swivel hook with a bolt and nut arrangement was used. The normal hook system would have allowed the workman to quickly hook the rope to the helicopter within seconds. Video tape showed the helicopter hovering above the workman and pole for 1-1/4 minutes until the tape stopped, just before the accident. The Operation Manual required 2-way radio communication between the pilot and ground crew, unless otherwise authorized by the Manager of Aviation Services. There was no communication between the pilot and ground crew from the time the helicopter was overhead until the accident occurred.