Accident Overview
On February 14, 2011, at approximately 0955 mountain standard time, an American Champion Aircraft 8GCBC, registration N885AC, sustained substantial damage after striking power lines while maneuvering southeast of Soda Springs, Idaho. The airplane was registered to and operated by the pilot-rated passenger under Title 14 Code of Federal Regulations Part 91. The certificated airline transport pilot, seated in the front seat, and the certificated private pilot passenger/owner, seated in the rear seat, both sustained serious injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight. The local flight originated from Afton, Wyoming, about 26 minutes prior to the accident.
Flight Narrative
According to the pilot, the evening before the accident, the airplane owner asked if he would like to fly as a safety pilot to help the owner gain more experience flying from the rear seat. On the day of the accident, they departed Afton intending for the pilot to fly around the area before the owner conducted practice takeoffs and landings from the rear seat. The pilot performed stalls and steep turns, then flew over a mountain range west of Afton that the owner was familiar with. After crossing the range, the pilot flew along a ridge line to observe wind conditions before entering an open valley at an altitude varying from 200 to 500 feet above ground level.
Upon entering the valley on a southerly heading, the pilot visually acquired a set of high tension power lines spanning east to west. The pilot believed he had sufficient altitude and began a shallow climb to ensure clearance. The owner verified the pilot had the lines in sight, and the pilot acknowledged, still believing he had enough altitude. Shortly after, the airplane struck the high tension power lines and subsequently impacted a snow-covered field.
In a written statement, the owner reported that the flight's intention was to enjoy the day. After departure, the pilot asked to perform stalls to familiarize himself with the airplane. Following the stalls, they flew north before turning south, flying low across the terrain. While following the Idaho-Wyoming border, the owner pointed out the power lines and suggested turning east toward the departure airport or climbing above the lines. The pilot replied, "I could just go under them," to which the owner responded, "absolutely not." The owner then reported that the pilot initiated a climb to an altitude that appeared to clear the lines safely.
Aircraft Damage and Wreckage
Examination by first responders revealed the airplane came to rest inverted in a deep snow-covered field approximately 200 feet south of the high tension power lines. The left wing was mostly separated from the fuselage, with a portion of the left wing located directly under the power lines.
Power Line Characteristics
A representative from Lower Valley Energy reported that the airplane struck one of three static wires, which are dull gray in color, located about 81 feet above the ground. The static wires were approximately 26 feet above a set of three main transmission lines that are shiny in color. The representative noted that the static wires were "very difficult to see in the lighting conditions that were similar to the day of the crash."
GPS Data Analysis
The owner provided a Garmin GPSmap 496 unit installed in the airplane. Recorded data showed the flight departed Afton, turned south, then to a northerly heading, during which two 360-degree turns were performed. The flight continued north until turning northwest over a mountain range west of Afton. As the airplane crossed the range, it descended and turned to a southerly course into a valley on the west side. GPS altitude data for the last 8 minutes varied between 6,340 and 8,101 feet. Comparing each plot with terrain elevation revealed the airplane's elevation varied between 18 and 384 feet above ground. The last recorded data point was 300 feet north of the power lines at an altitude of 6,885 feet; the terrain elevation in that area was 6,748 feet.