Page:CAB Aircraft Accident Report, American Airlines Flight 320.pdf/24



The Board determines the probable cause of this accident was premature descent below landing minimums which was the result of preoccupation of the crew on particular aspects of the aircraft and its environment to the neglect of essential flight instrument references for attitude and height above the approach surface.

Contributing factors were:


 * 1) Limited experience of the crew with the aircraft type;
 * 2) Faulty approach technique in which the autopilot was used in the heading mode to or almost to the surface;
 * 3) Erroneous setting of the captain's altimeter;
 * 4) Marginal weather in the approach area;
 * 5) Possible misinterpretation of altimeter and rate of descent indicator; and
 * 6) Sensory illusion with respect to height and attitude resulting from visual reference to the few lights existing in the approach area.

BY THE CIVIL AERONAUTICS BOARD: