Event
The single-engine aircraft departed Lensk at 0813 local time on a flight to Bratsk. While cruising at an altitude of 4,200 meters over a cloud layer, the engine failed. The crew elected to divert to Kirensk Airport but was unable to maintain a safe altitude. Subsequently, the captain attempted an emergency landing. The aircraft impacted trees and crashed in a wooded area located 37 kilometers west of Kirensk. All nine occupants sustained injuries, and the aircraft was damaged beyond repair.
Investigation
The official investigation was conducted to determine the cause of the accident.
Probable Cause
The investigation determined that the engine failure was due to damage of the bearings of the planetary gear from the first stage of the compressor, leading to vibration and destruction of the turbine. It is possible that the damage to the bearings was caused by the presence of aluminum or silicon oxide. However, it was not possible to determine the source of this contamination.