What happened
A cargo mission traveling from Mukachevo Airbase to Moscow ended in a fatal accident during the night. The aircraft was transporting a payload of air-to-air missiles intended for maintenance. Approximately 35 minutes after departure, the flight crew encountered an initial failure of the autopilot system accompanied by an audible alarm. The crew successfully identified the issue and reengaged the system, allowing the flight to proceed.
However, at the 1 hour and 43 minute mark of the flight, while cruising at an altitude of 7,500 meters, a second autopilot failure occurred. Unlike the first instance, this disconnection did not trigger an alarm, leaving the crew unaware of the malfunction. Within forty seconds of this second failure, the aircraft entered an uncontrolled dive and struck a swampy region near Semenivka. The impact caused the aircraft to disintegrate, resulting in nine fatalities among the crew.
Findings
Investigators were unable to definitively establish why the autopilot disconnected during the final phase of flight. Two primary theories were examined: an accidental disconnection by a crew member making physical contact with the controls, or a mechanical failure within a switch related to the autopilot command circuit. The investigation concluded that the crew's lack of monitoring contributed to the disaster, as they failed to notice the instruments and did not intervene quickly enough to stabilize the aircraft after the second failure.