What happened
While operating at an altitude of 10,200 meters, the crew of the Ilyushin Il-62 departed from Chelyabinsk and was cleared to begin its approach toward runway 05 at Alma-Ata Airport. During the nighttime descent, air traffic control instructed the pilots to perform a left turn and descend to 600 meters to maintain separation from another approaching II-62 located approximately eight kilometers to the right of their flight path.
As the aircraft descended into an unsafe altitude, the Ground Proximity Warning System (GPWS) triggered an alert in the cockpit. However, the crew did not respond immediately to this warning, delaying corrective maneuvers for 23 seconds. During this delayed reaction, the aircraft's nose pitched up by 14 degrees and the plane banked left at an angle of roughly 11 to 12 degrees. Two seconds after the maneuver began, the aircraft struck the slope of Mt Dolan, which stands at 690 meters, approximately 36 km west of Almaty Airport. The impact caused the airframe to disintegrate, and all 90 occupants perished in the accident. The debris field was located 24 meters below the mountain's summit.
Findings
Investigations into the disaster identified several contributing factors involving both flight crew performance and air traffic control operations. It was determined that the pilots did not execute the approach maneuver in accordance with established procedures and utilized non-standard phraseology during communications. Furthermore, ATC provided incorrect instructions that led to a premature descent to 600 meters, an altitude that placed the aircraft outside of the approved approach diagram. The crew's failure to act proactively following the GPWS alarm was also cited as a critical factor in the collision.