 Among the damage discovered after the accident, investigators found the #7 slat missing from the leading edge of the right wing.NTSB investigators requested the aircraft manufacturer, Boeing, inspect the remainder of the slat assembly, including a portion of the "slat actuator cylinder" (the motor that moves the slat and holds it in position).Boeing determined that the #7 slat had failed because the slats had been extended while the aircraft was flying at cruising speed.