Background
The pilot, who held an instrument rating, obtained a detailed weather briefing prior to departure. The briefing included surface observations along the intended route, significant meteorological information (SIGMET), airman's meteorological information (AIRMET), convective weather advisories, a convective outlook, an area forecast, pilot reports, radar summary, and winds aloft data. The area forecast indicated overcast ceilings at 1,500 feet mean sea level (msl) with cloud tops at 6,000 feet msl, visibility between 3 and 5 miles, light rain and mist, and isolated thunderstorms with cumulonimbus tops reaching 35,000 feet msl.
Sequence of Events
After departing, the pilot established contact with air traffic control, and the airplane was initially observed on radar heading toward the destination. Radar analysis later revealed that isolated thunderstorms were present along the route. Approximately 4 minutes after departure, the airplane entered an area of developing rain showers and vertical updrafts. The airplane then began a descending right turn, followed by a brief climb and another descent. During this sequence, the ground speed decreased from 202 knots to 110 knots before radar data ended, at which point the airplane was at 4,500 feet msl.
A witness reported hearing the airplane but could not see it due to a low cloud layer. Moments later, the witness observed the airplane exiting the cloud layer in a spin before it impacted the ground.
Investigation
A postaccident examination found no mechanical deficiencies that would have precluded normal operation of the airplane or its engine. The official probable cause was determined to be the pilot's encounter with convective weather, which resulted in a loss of airplane control.