The National Transportation Safety Board determines that the probable cause of this accident was the flight crew’s mismanagement of the airplane’s descent during the visual approach, the pilot flying’s unintended deactivation of automatic airspeed control, the flight crew’s inadequate monitoring of airspeed, and the flight crew’s delayed execution of a go-around after they became aware that the airplane was below acceptable glidepath and airspeed tolerances. Contributing to the accident were:
- the complexities of the autothrottle and autopilot flight director systems that were inadequately described in Boeing’s documentation and Asiana’s pilot training, which increased the likelihood of mode error;
- the flight crew’s nonstandard communication and coordination regarding the use of the autothrottle and autopilot flight director systems;
- the pilot flying’s inadequate training on the planning and executing of visual approaches;
- the pilot monitoring/instructor pilot’s inadequate supervision of the pilot flying;
- and flight crew fatigue which likely degraded their performance.
The NTSB reported that 6 occupants were ejected from the aircraft during the accident sequence, 2 passengers and 4 cabin crew. The cabin crew were wearing their constraints however were ejected due to the destruction of the aft galley. The two ejected passengers were not wearing their seat belts and could still be alive. One of these two passengers were rolled over by two fire trucks. The NTSB said that had these two passengers worn their seat belts, they would likely have remained within the cabin and survived the accident.