Accident Overview
A pilot lost control of an airplane while cruising at 16,000 feet in instrument meteorological conditions (IMC). The airplane entered a spin and impacted the ground at 7,100 feet mean sea level. An examination of the wreckage revealed no evidence of preimpact mechanical failures or malfunctions.
Weather and Pilot Actions
About one hour before departure, the pilot received a weather briefing. The briefer advised of an AIRMET along the proposed route, forecasting occasional moderate turbulence from the surface to 16,000 feet and occasional moderate icing in clouds and precipitation from the freezing level at 12,000 feet up through 24,000 feet. The airplane was not equipped or certificated for flight into known icing conditions.
While en route at 16,000 feet, with an average ground speed of 155 knots, the pilot encountered downdrafts. The pilot broadcast to the radar controller that he was "unable to maintain this altitude with this downdraft" and requested permission to descend to 15,000 feet, which was cleared.
Radar Data and Impact
Recorded radar data indicated that the airplane's course changed from northwesterly to southeasterly, then northeasterly, while ground speed gradually decreased to 61 knots. The last recorded radar position was at 8,800 feet, and the airplane impacted terrain within a 50-foot radius of this location.
About two hours after the accident, another pilot reported experiencing severe turbulence while descending from 16,000 to 13,000 feet over the accident site vicinity.