What happened
The aircraft departed from Murmashi Airport in Murmansk on a medical evacuation mission to Arkhangelsk. The flight carried four wounded soldiers as passengers along with the pilot. Approximately two hours after takeoff, the engine began to lose power before failing completely. In response, the pilot attempted an emergency landing. The airplane crashed into a bog situated 270 km southeast of Murmansk and came to rest upside down.
All four passengers managed to escape the wreckage with injuries, while the pilot was killed in the accident. Following the crash, the survivors were smoking near the debris when they unintentionally started a fire. This secondary incident destroyed the airframe, preventing further physical inspection of the engine components.
Findings
Official investigators concluded that the specific cause of the initial engine failure could not be determined. The destruction of the aircraft by the post-accident fire eliminated the necessary evidence required to identify the mechanical root cause.