Vertical alignment of a movable bridge with a doorway of an aircraft is
achieved by moving a sensor disposed on the movable bridge in a generally
downward direction so as to sense a position of an upper surface of the
aircraft. The upper surface of the aircraft has a known elevational
relationship relative to the doorway of the aircraft, which is used along
with the sensed position to align an aircraft engaging portion of the
movable bridge with the doorway. The method accommodates different
heights of a same model of aircraft resulting from differences in the
aircraft loads and is easily implemented using non-contact sensors.