WPR19LA055

There were no witnesses to the accident; however, a witness saw the airplane flying about 10 to 15 feet above the river before it disappeared from view behind the riverbank. The pilot reported that he had no memory of the event and could not recall the accident flight; the passenger stated that, near the end of the flight, “a line wire got in the way.” The airplane came to rest in a snow-covered field about 1/4 mile from power transmission lines that had been broken, and the vertical stabilizer displayed damage consistent with a wire strike. Examination of the airframe and engine revealed no evidence of preaccident mechanical malfunctions or anomalies that would have precluded normal operation. The circumstances of the accident are consistent with the pilot’s decision to operate at low level, and his failure to maintain clearance from power lines. Astronomical data revealed that the accident occurred about 1 minute before sunset, which may have contributed to the pilot’s failure to see and avoid the power lines.

On January 2, 2019, about 1650 mountain standard time, a Cessna 180 airplane, N4934A, was substantially damaged when it was involved in an accident near Townsend, Montana. The pilot and passenger were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A witness reported that the airplane was flying in a westerly direction about 2 1/2 miles west of Townsend Airport (8U8), Townsend, Montana, then made a sharp left turn over the river. The witness estimated that the airplane was about 15 to 20 ft above the river and was so low that he lost sight of it, as it was lower than the riverbank. He further stated that, although the airplane was low, it appeared that the pilot was in control, and there were no indications that the airplane was in distress. The pilot reported that he had no memory of the event and could not recall the accident flight. The passenger stated that, near the end of the flight, “a line wire got in the way.” Local law enforcement received reports that an airplane had crashed and that power transmission lines crossing the Missouri River were broken. The utility company that supplied electricity to the area stated that an electrical outage was reported about 1650. The wreckage was located in a snow-covered field about 1/4 mile southeast of a set of power transmission lines that spanned the river in a southwest-to-northeast direction (see figure). A broken tree limb and ground scars at the accident site were consistent with the airplane flying east over the river before impacting a tree and then the ground. The airplane came to rest upright, and the landing gear separated. The wings were buckled and partially separated near the fuselage. The forward fuselage and cabin area were crushed and distorted. The rear fuselage was buckled near the empennage. The empennage was missing the rudder and about 12 inches of the upper vertical stabilizer. Figure - Google Earth view, accident site. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or anomalies that would have precluded normal operation. Several impact marks were found on the rudder consistent with a cable strike, and the vertical stabilizer showed cable strikes and electrical arcing. Astronomical data obtained from the United States Naval Observatory for the accident site on the day of the accident indicated that sunset was at 1651, the end of civil twilight was at 1726, and moonset was at 1442.