What happened
A positioning flight traveling from Moscow-Domodedovo Airport to Bishkek-Manas Airport for cargo loading experienced a series of critical flight instabilities during its approach to runway 26. As the aircraft passed the outer marker, it began oscillating in both heading and bank angle for approximately 15 seconds. During the final approach, the aircraft was noted to be at an altitude of 30 metres while traveling at 293 km/h, which was significantly higher than the required 15 metres.
At an altitude of 20 metres and a speed of 297 km/h, the crew deployed the thrust reversers on the first and fourth engines. This action violated regulations, as reversers should only be utilized at a leveling-off altitude between 5 and 8 metres. This deployment, combined with an improper weight distribution, caused the nose to pitch up to a 7° angle. Despite the crew applying 13° of nose-down elevator, the pitch could not be corrected.
The aircraft touched down on its main landing gear 1,395 metres along the 4,200-metre runway. During the landing roll, the flight engineer shut down the second and third engines without notifying the pilot in command. Even with the elevator deflected 10-11° downward, the nose gear failed to make contact with the runway. After the thrust reversers were retracted, the nose pitch dropped sharply from +7° to -2.5° within a few seconds. A subsequent trim adjustment from -3.3° to +9° caused the pitch to increase once more.
The Ilyushin Il-76 eventually exited the left side of the runway 3,001 metres past the threshold. The aircraft continued its path until it struck a concrete obstruction, which triggered a fire that destroyed the aircraft. There were 0 fatalities reported in the source material, though the aircraft was a total loss.
Findings
- The aircraft's center of gravity was outside of permissible limits because the water ballast tanks had not been filled.
- Improper deployment of thrust reversers at an excessive altitude contributed to the uncontrollable pitch-up.
- Unauthorized engine shutdowns by the flight engineer during the landing roll hindered the crew's ability to control the aircraft's attitude.