What happened
On the second leg of a journey traveling from Vitim to Olyokminsk, a single-engine airplane departed from Lensk Airport at 09:09 local time. Approximately one hour into the flight, while the aircraft was maintaining a cruising altitude of 1,500 meters, the crew experienced significant engine vibrations.
In response to the mechanical issues, the crew initiated an emergency descent to attempt a landing. During this process, the aircraft struck trees and came to rest in a forested region situated 122 kilometers northwest of Olyokminsk. Upon impact, the plane caught fire, resulting in the total destruction of the airframe.
Despite the severity of the crash and the subsequent fire, all nine occupants successfully exited the wreckage without sustaining any injuries.
Findings
Investigations into the accident determined that the engine failure was triggered by the disintegration of the 4th cylinder intake valve.