What happened
After weather conditions improved, the crew received clearance for takeoff from Kuybyshev Airport. They departed at 1127 local time on a scheduled flight to Sverdlovsk. During the initial climb and subsequent cruise, the pilot maintained an altitude of only 50 metres. As the aircraft passed over the village of Sok-Karmala, visibility deteriorated rapidly due to fog.
In these low-visibility conditions, the airplane struck trees. The impact caused the aircraft to lose height, leading it to crash 135 metres further downrange. Upon impact, the airframe burst into flames. The pilot was killed in the accident, while the flight engineer sustained serious injuries.
Findings
The official investigation concluded that the primary factor in the disaster was the decision to continue the flight at an unsafe altitude. This action was taken despite insufficient visibility caused by foggy conditions, which ultimately led to the collision with obstacles on the ground.