Guidance computer for aircraft landing system

Claim 1

APPARATUS FOR USE IN AIRCRAFT LANDING SYSTEM COMPRISING: (A) MEANS FOR PRODUCING A FIRST SIGNAL REPRESENTING THE DISTANCE OF THE AIRCRAFT FROM A REFERENCE POINT THAT IS IN ADVANCE OF A SITE LOCATED BEYOND AN INTENDED TOUCHDOWN REGION, (B) MEANS FOR PRODUCING A SECOND SIGNAL REPRESENTING A DESIRED ELEVATION ANGLE FROM A POINT IN ADVANCE OF SAID TOUCHDOWN REGION, (C) A RESISTOR NETWORK COMPRISED OF FIRST AND SECOND RESISTORS EACH HAVING ONE END RESPECTIVELY CONNECTED TO FIRST AND SECOND ENDS OF A REHOSTAT THAT INCLUDES A MOVABLE CONTACT AND AT LEAST TWO ADJOINING RESISTIVE PORTIONS, THE FIRST RESISTIVE PORTION, CONNECTED TO THE FIRST END OF THE RHEOSTAT, PROVIDING THE HIGHEST RESISTANCE VALUES WHICH VARY LINEARLY AS A FUNCTION OF MOVEMENT OF THE MOVABLE CONTACT AND THE SECOND RESISTIVE PORTION PROVIDING PROGRESSIVELY LOWER RESISTANCE VALUES WHICH VARY NON-LINEARLY AS A FUNCTION OF THE MOVEMENT OF SAID MOVABLE CONTACT, (D) MEANS FOR VARYING THE POSITION OF THE MOVABLE CONTACT AS A FUNCTION OF SAID FIRST SIGNAL, (E) MEANS COUPLING SAID SECOND SIGNAL TO THE OTHER END OF SAID FIRST RESISTOR TO PROVIDE AT THE MOVABLE CONTACT OF SAID RHEOSTAT A DESIRED ELEVATION ANGLE SIGNAL REPRESENTING A DESIRED FLIGHT PATH TO BE FOLLOWED BY THE AIRCRAFT TO SAID TOUCHDOWN REGION.