What happened
During an approach to the destination airport, the pilot received clearance to descend to a specific altitude. Radar tracking indicated that as the aircraft reached the assigned level, it initiated a right turn, followed by a period of rapid climbing and subsequent rapid descending in a spiral-like trajectory. The wreckage was located the next day within a mountainous area, surrounded by tall trees. Evidence at the site, including scuff marks on tree trunks, suggested the aircraft struck the ground in a near-vertical descent. All parts of the aircraft were recovered from the crash site.
Findings
An inspection of the aircraft following the accident revealed that the engine and airframe were functioning correctly and showed no signs of failure prior to the impact. Meteorological analysis indicated that the flight path passed through the vicinity of a stationary front. The atmospheric conditions were characterized by moderate to severe turbulence, moderate icing, and mountain wave activity, which included updrafts and downdrafts exceeding 750 feet per minute. Radar data showed the aircraft entered cumuliform clouds just before the rapid descent began. The evidence suggests the pilot lost control of the aircraft while attempting to maneuver through severe turbulence.