Accident
While cruising at an altitude of 7,800 meters at night, the electrical system of the airplane failed. This caused several instruments, including the gyros, to malfunction. The autopilot also failed. Control of the airplane was lost, and it entered a dive. The airplane eventually crashed in an open field located 150 meters from the village of Verkhnyaya Khava, approximately 50 kilometers northeast of Voronezh. The impact angle was nose-down at 70 degrees. The airplane disintegrated upon impact, and some debris were found at a depth of 14 meters. All 111 occupants were killed.
Investigation
Investigators determined that the failure of the 36-volt electrical system in flight led to the loss of the autopilot system and instruments such as gyros. The exact cause of the electrical system failure could not be determined. While flying at night and in visibility reduced by clouds, the crew was unable to obtain visual references. They lost control of the airplane after suffering spatial disorientation.
Probable Cause
The official probable cause was the failure of the 36-volt electrical system in flight, which caused the autopilot and gyroscopic instruments to fail. The exact reason for the electrical failure could not be determined. The crew, operating in night conditions with reduced visibility due to clouds, lost visual references and subsequently lost control of the airplane as a result of spatial disorientation.