Incident
Twenty-four seconds after takeoff, during the initial climb, the crew encountered controllability problems. The captain contacted air traffic control and reported uncommanded rolling movements to the left and right of up to 30°. The aircraft continued to climb but reached a high angle of attack when the nose pitched up to 20°, activating the stall warning alarm. The aircraft attained an altitude of 4,717 metres before rolling to the left, pitching down to an angle of 65°, and entering an uncontrolled descent. At a speed of 747 km/h, the aircraft descended to an altitude of 2,884 metres in 12 seconds. The aircraft then suffered structural deformation and failure before crashing in an open field located 29 kilometres southeast of Xi'an Airport. The aircraft disintegrated on impact, and all 160 occupants were killed.
Probable Cause
The official investigation determined that the loss of control was the consequence of poor maintenance. The previous evening, after maintenance was completed at an unapproved facility, the autopilot yaw-channel had been erroneously connected to the bank control and the bank-channel to the yaw control.