Incident Overview
A twin-pilot aircraft was operating a mail flight from Tomsk to Baturino, carrying 757 kg of mail, 120 kg of various goods, two pilots, and a passenger responsible for the freight. Six minutes before the estimated time of arrival in Baturino, while cruising at an altitude of 200 meters, the engine failed. The crew elected to make an emergency landing.
Emergency Landing and Crash
During the emergency landing, the airplane struck trees and crashed inverted in a wooded area located 13 km from Baturino. The captain was killed, while both other occupants sustained injuries.
Investigation Findings
The investigation could not determine the exact cause of the engine failure. However, it is believed that the failure may have been caused by an excessive accumulation of calamine on the intake valves. The official probable cause statement notes that the precise reason for the calamine buildup remains unknown.