Abstract: On February 23, 2001, a power line worker, who was transferring from a platform on a helicopter to an electric power transmission structure, died when he fell 27.4 meters (90 feet) to the ground. The line worker sat outside the helicopter on an aluminum work platform that was attached to the helicopter while he was being transported by helicopter from the ground to atop an electric power line transmission structure. (The platform was approved by the Federal Aviation Administration.) In route and before the transfer, the line worker was to have his lanyard attached to a D-ring on the side of the helicopter. Normally, while on the platform, the line worker and the pilot would be in on-board intercom communication with each other. However, before the line worker would attach a bonding jumper from the helicopter to the shield wire on the electric power transmission structure, the practice called for the line worker to disconnect from the intercom, thereby losing verbal communication with the pilot. During the transfer from the platform to the electric power transmission structure, the line worker was to disconnect the lanyard. The pilot, while looking at the line worker and the drop site, was to visually confirm that the line worker had transferred to the power pole, and then the pilot was to move the helicopter laterally out and away from the structure. OSHA's investigation determined that the line worker had not fully detached from the helicopter. It was also discovered that the worker's lanyard was not hooked to the D-ring attachment on the side of the helicopter but rather to the strut assembly for the aluminum work platform. The strut connected the platform to the helicopter and functioned as shock absorber. The strut parts were sent to a testing laboratory for evaluation. A bolt that was part of the strut assembly was found to have sheared. It was found that the bolt failed under the stress of the weight exerted on it because the line worker was constantly using the strut assembly for attachment. The National Transportation Safety Board determined the probable causes of this fatality as follows: The line worker's failure to use the designed attachment point for securing his safety harness to the helicopter, resulting in overload and failure of the component he did attach to. A factor in the accident was the line worker's failure to follow exact sequential procedures for performing the in-flight transfer from rotorcraft to structure, resulting in his being dragged off the structure by the retreating rotorcraft.