Aircraft Accident/Incident Report

Desert Aire, Washington 99349
Friday, November 6, 1998 12:25 PST

Approximately 4 hours into a U.S. Fish and Wildlife Service (USFand WS) low-level waterfowl survey flight along the Columbia River, while flying down river (eastbound), the aircraft struck a static line on a power line crossing the river and crashed into the river. The pilot escaped the aircraft with serious injuries, but two USFand WS employees aboard the aircraft, acting as observers for the waterfowl survey, did not escape the submerged aircraft and drowned. The pilot reported that at the time of the wire strike, he saw the transmission lines and towers and was climbing to clear the transmission lines, but that he was unaware of the smaller-diameter static line's presence above the transmission lines and did not see it. The aircraft struck the static line 122 feet above the surface. The static line, the highest wire on the structure, was not marked according to current FAA standards. An FAA aerial survey of the crossing conducted after the accident revealed that while an adjacent power line crossing approximately 1/4 mile east of the accident crossing was conspicuously marked and lighted, the lines which were struck were very difficult to see even in good visibility conditions.

The pilot's failure to maintain adequate altitude and/or clearance over a power line crossing the river, resulting in collision with a static wire at the top of the crossing structure. Factors included the static wire, and inadequate marking of the static wire.