What happened
During a mission for the Kazakh Border Guard Corp, an aircraft crashed into a mountain slope approximately 21 km from Shymkent. The accident occurred during a night approach characterized by heavy snowfall and low visibility. The impact forces were sufficient to destroy the aircraft.
Following departure from Astana, the aircraft experienced a failure of the automatic pilot system. Despite this, the crew proceeded with the flight. Shortly after, the radio altimeter also ceased to function, forcing the crew to rely on the barometric altimeter for altitude information. Approximately 19 minutes after the radio altimeter failure, the barometric altimeter experienced a momentary malfunction, leading to discrepancies in altitude readings.
Findings
Investigations into the crash revealed that during the descent into Shymkent, the captain did not apply the correct pressure settings to the barometric altimeters. This error meant the altitude reference used by the crew was inaccurate. At the time of the collision, the aircraft was flying 385 meters below its intended altitude. The investigation concluded that the primary cause was a controlled flight into terrain (CFIT).