What happened
During a nighttime cruise at an altitude of 7,800 meters, the aircraft was operating under favorable weather conditions. While the pilot-in-command was executing a left turn, the crew lost control of the plane. The aircraft subsequently entered a spiral dive toward the earth.
As the descent continued and the altitude reached approximately 5,000 meters, the structural integrity of the airplane failed. Components from the upper wing surface and the stabilizers broke away from the airframe. This mid-air disintegration preceded the final impact in a steppe area situated roughly 84 km south of Semipalatinsk. Debris from the wings and stabilizers was discovered approximately 3.5 km away from the primary wreckage site.
All 63 occupants on board perished in the accident.
Findings
Investigators were unable to reach a definitive conclusion regarding the precise cause of the accident. While investigators did not rule out the possibility that the aircraft struck an external object, no specific cause was confirmed. There is a possibility that the crew initiated an emergency descent, though the motivation for such a maneuver remains unidentified. Data recovery was significantly hindered because the Flight Data Recorder sustained severe damage during the impact, rendering it unreadable.