Flight and Incident
A single-engine aircraft, identified as An-2 with registration RA-40646, departed Kodinsk at 1400 local time on a survey flight. On board were five fire bombers and four crew members, consisting of two pilots and two observers. Approximately two hours into the flight, an occupant spotted a fire. The crew released all five fire bombers with their materials in two groups.
Emergency Landing
After dropping the fire bombers, the crew increased engine power and continued flying at an altitude of about 150 to 200 metres. The engine oil temperature began to rise, reaching 150 degrees Celsius. Five minutes later, the engine failed. The crew attempted an emergency landing. During the landing, the aircraft struck 20-metre-tall trees, stalled, and crashed in a wooded area. The wreckage was discovered south of Kezhma, approximately 126 kilometres east of Kodinsk. All four occupants evacuated safely, but the aircraft was destroyed.
Official Findings
The investigation determined that the accident occurred during an emergency landing on a forest. The landing was necessitated by an inadvertent in-flight engine shutdown caused by destruction of the bronze filling of hub 62.06.02 of the master rod big end of the crank mechanism. The destruction of the bronze filling was most likely due to a manufacturing flaw, specifically a lack of bronze adhesion with the steel base on part of the surface.