The Li-2 operated on flight 525 from Sverdlvosk-Koltsovo Airport to Kazan, Penza and Stalingrad, and Mineralnye Vody. The flight departed Stalingrad at 14:02 hours. After 1 hour and 27 minutes of flight, while at 2100 m altitude, the plane entered a snowfall. As a result of electrostatic interference, the crew was unable to tune the radio compass to Mineralnye Vody Airport. The crew turned back to Stalingrad, while climbing to 3000 m. Coming out above the clouds, the crew was now able to tune the radio compass to Mineralnye Vody Airport. At 16:05, the crew turned the plane back to Mineralnye Vody, dropped to 2700 m and reported this to the Rostov ATC controller, but did not indicate its flight altitude. The controller allowed the crew to continue the flight at 2100 m. However, the crew continued the flight at 2700 m. At 16:12, the controller allowed the crew to switch to communication with the radio direction-finding unit of Mineralnye Vody and did not try to call the plane again. At 16:44, the plane encountered light icing and snowfall. The radio compass readings became unstable again. The crew descended to 1500 m and then further down to an altitude of 300 m, continuing visually over mountainous terrain. This was far below the minimum altitude for that sector of 1500 m. The aircraft entered an area with snowfall and a visibility of 20-30 m. Having descended even more, the plane collided with the roof of a shed. It then hit a stone structure and crashed in a field. The captain of the aircraft was killed. The rest of the crew and passengers were injured.