Incident Overview
An aircraft operating a flight from Chelyabinsk was cleared to initiate an approach to Alma-Ata Airport for a landing on runway 05. The flight had been uneventful at an altitude of 10,200 meters. At night, the crew received instructions to execute a left turn and descend to 600 meters, after being advised of an II-62 aircraft located eight kilometers to the right of their position.
Sequence of Events
During the descent, the aircraft descended too low, triggering the Ground Proximity Warning System (GPWS) in the cockpit. For reasons that were not determined by the investigation, the crew did not react immediately. The first corrective maneuver was initiated 23 seconds after the GPWS warning. The aircraft pitched up to an angle of 14° and then banked left to an angle of 11–12°. Two seconds later, it struck the slope of Mount Dolan, which has an elevation of 690 meters and is situated approximately 36 kilometers west of Almaty Airport. The impact caused the aircraft to disintegrate, and all 90 occupants on board were killed. The wreckage was located 24 meters below the summit of the mountain.
Probable Cause and Contributing Factors
The official investigation determined that the crew failed to prepare the approach maneuver in accordance with published procedures. Air traffic control did not provide proper assistance and transmitted incorrect instructions, which caused the aircraft to descend prematurely to an unsafe altitude of 600 meters, outside the designated approach diagram. The crew did not take proactive action when the GPWS alarm sounded, and the corrective action was performed too late. Additionally, the phraseology used by the pilots was found to be non-standard.