What happened
On September 12, a special flight departed from Surgut, traveling toward Saranpaul and Arbyn. The flight was operated for the Sosvapromgeologya Company and was transporting two pilots and five employees. During the return leg of the journey, originally scheduled for September 18, the crew altered their flight path toward Nefteyugansk due to unfavorable weather conditions.
Approximately 70 minutes into the flight, while the aircraft was cruising at an altitude of 700 meters, the crew observed a sudden rise in engine temperatures. Specifically, the engine temperature reached 305°C, while the oil temperature climbed to 90°C. Simultaneously, the engine experienced a loss of power. In response to the mechanical failure, the crew attempted an emergency descent to perform a landing.
The aircraft subsequently crash-landed in a field situated 48 km west of Nyagan. While the impact resulted in the aircraft being damaged beyond repair, no fire broke out during the incident. All seven occupants sustained injuries during the crash.
Findings
During the cruise phase, the aircraft experienced a critical engine power loss accompanied by a significant increase in both oil and engine temperatures.