What happened
During a flight through instrument meteorological conditions, an aircraft experienced a catastrophic loss of control while cruising. Prior to departure, the pilot had received a weather briefing from AFSS that detailed hazardous conditions along the intended route, including snow, rain, freezing rain, icing, and turbulence. Although cloud tops were forecasted at 25,000 feet, the pilot's flight plan specified a cruise altitude of 28,000 feet.
Approximately 32 minutes into the flight, the pilot reported an issue with the attitude gyro and indicated that the aircraft was being hand-flown. While the aircraft maintained its altitude for several minutes, the pilot subsequently declared an emergency before briefly stating the issue had resolved. Shortly thereafter, the pilot expressed a need to descend to find visual conditions. Radar data showed the aircraft descending to 27,000 feet and then entering a series of erratic, steep climbs and descents.
A nearby commercial airline pilot reported hearing the pilot state that the aircraft was in a spin. The radar signal was lost when the aircraft reached an altitude of 2,500 feet. The aircraft ultimately struck the terrain in a steep, nose-down attitude, leading to a post-impact fire that destroyed the plane. There was one fatality.
Findings
Investigations into the wreckage and flight history revealed that the engines, flight controls, and flight instruments showed no evidence of pre-existing mechanical anomalies. However, a witness noted that the pilot had mentioned problems with the attitude gyro two days before the accident, though there was no documentation that an inspection had been performed. Additionally, while the pilot frequently utilized autopilot shortly after takeoff, there were no observations of the pilot hand-flying the aircraft in instrument conditions prior to this event.