The purpose of the flight was to film a moving train. Prior to commencing the operation, the pilot made an aerial inspection of the area and mentally noted the various obstructions. On the second filming run the helicopter collided with power lines at a height of 33 feet above ground level. The helicopter descended and struck the ground about 50 metres beyond the point of collision. It then bounced and came to rest on its side. The pilot was highly experienced in aerial photography and survey operations. At the time of the accident, visibility was reduced to less than 2 kilometres in light rain. One of the poles supporting the power lines was hidden from the pilot's view by a large tree. It was also possible that the pilot had flown outside the area he had previously inspected, as he had not been aware of the presence of the particular set of wires.
