What happened
While operating at 7,800 feet and approximately 40 km from the airport, the crew received clearance for a visual approach and instructions to descend to 7,000 feet. Roughly three minutes following this clearance, the aircraft lost control and struck a mountain slope at an elevation of 1,600 metres. The impact occurred 27 km south of runway 36. The crash resulted in the total destruction of the aircraft and 141 fatalities.
Findings
Investigations into the accident revealed that the captain had attempted to stabilize the aircraft by pulling back on the controls to raise the nose. During this maneuver, the autothrottle system reacted by increasing engine power; however, a malfunction occurred where the number 2 power lever remained at idle. The crew failed to identify this discrepancy. To compensate for the lack of thrust on the right side and maintain the required airspeed, the autothrottle increased power to the left engine. This created an asymmetrical power condition that the crew did not rectify, causing the aircraft to roll heavily to the right and descend into the terrain.