What happened
On April 7, 2008, an amateur-built Glasair III, registration C-GGTM, crashed near Cheyenne, Wyoming, resulting in 1 fatality.
The flight originated from South Big Horn County Airport (GEY) in Greybull, Wyoming, with an intended destination of Larned-Pawnee County Airport (LQR) in Kansas. The pilot was operating under visual flight rules (VFR) and was receiving radar flight following service from Denver Air Route Traffic Control Center (ARTCC).
At approximately 15:13, the pilot requested a descent to 9,500 feet to penetrate cloud cover. The air traffic controller advised the pilot to maintain VFR and noted that the minimum IFR altitude in the area was 10,000 feet. Radar data showed the aircraft began descending from 15,500 feet and performed a series of turns, including a 90-degree left turn and a 270-degree left turn, while continuing to descend. The last radar contact occurred at 15:26, approximately 7 miles north of the accident site.
A witness near the site reported hearing an aircraft fly at a low altitude followed by a muffled thud. The witness noted that visibility was extremely low, between 100 and 150 feet, due to heavy falling snow and near whiteout conditions.
The investigation
An examination of the wreckage by the FAA revealed the aircraft impacted an open field and came to rest upright at an elevation of 5,935 feet MSL. The investigation of the airframe and flight control system showed no evidence of mechanical malfunction prior to impact. The engine remained attached to the firewall, and rotational continuity was established throughout the engine and valve train. The propeller remained attached to the crankshaft, though it exhibited bending and scratching consistent with impact.
An autopsy determined the cause of death was multiple blunt force injuries. Toxicology tests performed by the Civil Aeromedical Institute were negative for drugs, alcohol, and carbon monoxide.