ATL82FA144

The plt was flying railroad officials to inspect rail lines that had been covered by mud slides caused by recent heavy rains. A witness heard the helicopter coming up the valley & then heard two popping sounds. He saw the helicopter falling to the ground near some power lines strung across the valley over the railroad tracks. The power line assembly consisted of two static lines at the top & three power lines at the bottom. The uppermost static line was separated & lying on the lower static line. The lines are approximately 300 ft AGL & were unmarked. The plt was familiar with the operating area & purportedly aware of the location of the power lines.