What happened
While traveling toward its destination airport, a commuter aircraft encountered inclement weather consisting of rain showers and low cloud ceilings. The flight was operating over mountainous terrain at the time of the incident. Although the aircraft was not certified for instrument flight rules (IFR) commuter operations, the pilot attempted to continue the flight under visual conditions.
During the flight, the pilot requested and was granted visual clearance into the terminal control area (TCA), notifying air traffic control that the aircraft was at an altitude of 5,100 feet MSL. During the readback of this clearance, the pilot's radio communications became distorted. Shortly after this transmission, radar controllers observed the aircraft's target deviate left from its westward heading and subsequently vanish from radar surveillance. No further contact was established with the crew.
Following the failure of the aircraft to reach its destination, an alert was issued. Search efforts located the wreckage the next morning. The aircraft had struck a mountain approximately 10 miles south of its intended course at an elevation of 4,100 feet MSL.
Findings
Investigations into the accident revealed that the pilot had a history of successfully operating this specific aircraft in IFR conditions. However, the aircraft itself lacked the necessary certification for such operations during commuter flights. The loss of radar contact occurred immediately following a distorted radio transmission and a sudden change in the aircraft's flight path.