The means for guiding and controlling aircraft from an initial approach altitude to a point where safe contact is made with the landing surface. Such systems differ from low-approach systems in three major respects: (1) They furnish not only guidance but control of the aircraft as well. (2) They furnish information on the aircraft's position with respect to the terrain, and the rate at which the landing surface is being approached. (3) They do not require the pilot to assume manual control near the ground.