Accident Overview
A cargo flight encountered an emergency during cruise at 8,000 feet MSL when the right engine lost power. The pilot alerted ATC and received radar vectors toward an airport. Despite maintaining the best single-engine rate-of-climb speed, the airplane's altitude gradually decreased. Upon entering clouds, structural ice accumulated, and the airplane could not sustain altitude. It subsequently impacted mountainous terrain approximately 16 miles northwest of the intended airport.
Pilot Report
The pilot stated that the flight had departed with 5 hours of fuel for an estimated 2.5-hour journey. Conditions at the time of the accident were described as dark and foggy. After the engine failure, the pilot reported a gradual altitude loss despite attempts to maintain climb performance.
Postaccident Examination
Examination of the engines and airframe revealed no evidence of preimpact mechanical malfunction. A postaccident engine test run showed the right engine started normally and operated satisfactorily. The investigation did not determine a specific reason for the right engine power loss.
Probable Cause and Contributing Factors
The official findings identified the probable cause as a loss of power in the right engine for undetermined reasons, combined with structural ice accumulation, resulting in an increased rate of descent and a forced landing before reaching an alternate airport. Factors included adverse weather (icing conditions), darkness, fog, and the lack of suitable terrain in the emergency landing area.