Accident Summary
On a scheduled flight from Khabarovsk to Tynda with an intermediate stop in Blagoveshchensk, an aircraft operating as flight 2G/AGU2311 departed Ignatyevo Airport at 1121 local time for the second leg to Tynda. The aircraft carried 42 passengers (including five children) and six crew members. During the descent, the crew was cleared for an NDB approach via LMM and a landing on runway 06. Weather at the destination was marginal, with scattered clouds at a base of 210 meters.
Descent and Collision
After setting the altimeters, the crew continued the approach. The radio altimeter alarm sounded, and three seconds later, the aircraft collided with trees and crashed in a wooded area 14 kilometers southwest of the airport. The aircraft burst into flames and was destroyed. All 48 occupants were killed.
Probable Cause
The official investigation determined that the accident resulted from a discrepancy between the altitude reference level based on the QNH pressure actually set on the barometric altimeters and the reference level used by the crew for assigned flight altitudes (based on QFE). This led to the aircraft flying approximately 600 meters below the assigned altitude, colliding with treetops and the ground.
The following factors contributed to the accident:
- The crew's actual lack of preparedness to operate to aerodromes that had transitioned to QNH, which led to errors in the use of aerodrome pressure values (QNH/QFE) at Tynda aerodrome.
- The controller transmitting the QNH value, expressed in millimeters of mercury, without a request from the crew.
- The crew's failure to monitor the consistency between the barometric pressure settings used and the assigned altitude values.
- The inability of ATC to monitor the aircraft's flight altitude instrumentally due to inoperative secondary radar equipment at Tynda aerodrome.
- The crew's deactivation of the aural Ground Proximity Warning System (GPWS) alert.