On July 24, 2025, an An-24RV, registration RA-47315, was operating flight AGU-2311 on a scheduled route from Khabarovsk to Blagoveshchensk and Tynda. The crew included a captain, first officer, flight engineer, and a flight attendant.
During the daytime flight, the aircraft was performing a maneuver for an instrument approach under instrument meteorological conditions. The aircraft collided with treetops and the ground, resulting in 48 fatalities and no other injuries.
The investigation identified a discrepancy in the altitude reference level used by the crew. The crew was utilizing atmospheric pressure based on QFE, while the barometric altimeters were set to QNH pressure. This error caused the aircraft to fly approximately 600 meters below the required altitude.
Several contributing factors were identified, including the crew's lack of preparation for airports requiring QNH settings and the deactivation of the radio altimeter's audible warning system. Additionally, the air traffic controller provided the QNH pressure value in millimeters of mercury without a request from the crew, and a malfunction in the secondary radar equipment at Tynda airport prevented the controller from instrumentally monitoring the aircraft's altitude.