The pilot-in-command's failure to maintain sufficient distance from a transmission wire, arcing of the transmission wire, the failure of company personnel to utilize a nonconducting cable, and an inadequate procedure utilized by the construction project manager to ensure adequate fault protection on an energized transmission wire. Factors in the accident were a failure of the helicopter operator to maintain sufficient standards, including flight and ground crew coordination, and a failure to maintain radio communication between the pilot and ground crew.