What happened
The aircraft was operating a scheduled cargo route from Moscow to Khabarovsk, with planned intermediate stops in Krasnoyarsk and Irkutsk. The load consisted of 2,204 kilos of various goods and 115 kilos of mail. While en route to Irkutsk at an altitude of 3,000 meters, the left engine ignited. Although the crew successfully extinguished the initial fire, the captain elected to divert to Nizhneudinsk Airport for a precautionary landing.
As the aircraft descended with only the right engine operational, the crew struggled to maintain safe altitude. To reduce weight, the mail bags were jettisoned. At an estimated height of 40-60 meters, the plane struck the tops of several larch trees, stalled, and crashed into a grain field located 5 km southeast of the Sheberta rail station, northeast of Marga. The impact resulted in 13 fatalities among the occupants, while one crew member sustained injuries. The airframe was destroyed.
Findings
Investigations determined that the engine fire originated from a mechanical failure in the left engine. Specifically, piston #12 broke during flight due to a defect in the upper part of the connecting rod, which was attributed to a bore default during construction. This failure caused a bolt to break, leading to fuel leakage that ignited upon contact with high-temperature components.
Experts also cited crew decision-making as a contributing factor. It was noted that the crew did not attempt an immediate emergency landing despite the severity of the situation. Instead, they attempted to reach Nizhneudinsk Airport, which was located 60 kilometers from their position at the time of the incident.