What happened
During a repositioning flight to an airport near a private residence, an aircraft encountered severe weather while navigating a mountain pass. The pilot had previously diverted the flight the prior day due to unfavorable weather and had attempted a second departure on the day of the accident, only to return to the departure point due to ongoing weather issues. After waiting for conditions to clear, the pilot departed again in the afternoon, including a stop at an intermediate airport for refueling.
As the aircraft traveled northbound along a highway, it was flying beneath an overcast layer. Witnesses reported that the mountain pass was obscured by clouds and that a thunderstorm was developing to the west and moving toward the pass. One observer noted that the aircraft descended vertically from the cloud base while spinning in a level attitude. At the time of the impact, visibility was approximately 0.25 miles due to snowing conditions. The aircraft struck the ground in a level attitude and was destroyed by a post-crash fire.
Findings
An investigation of the engine, airframe, and flight controls found no mechanical failures or anomalies that would have prevented the aircraft from operating normally. The aircraft was not equipped or maintained for instrument flight. The investigation concluded that the pilot likely suffered from spatial disorientation after encountering instrument meteorological conditions. This led to the aircraft exceeding its critical angle of attack and entering a flat spin at a low altitude, resulting in the uncontrolled descent and impact.