Aircraft control systems

Claim 1

IN A LANDING CONTROL SYSTEM FOR AIRCRAFT, THE COMBINATION COMPRISING: (A) MEANS FOR PRODUCING A REFERENCE PITCH ATTITUDE SIGNAL ADAPTED TO CONTROL AN AIRCRAFT TO MAINTAIN A SUBSTANTIALLY LINEAR APPROACH PATH TO A PREDETERMINED FLARE-OUT ALTITUDE, (B) MEANS FOR PRODUCING A SECOND SIGNAL ADAPTED TO CONTROL SAID AIRCRAFT TO MAINTAIN A PREDETERMINED FLARE-OUT PATH, (C) MEANS FOR PRODUCING A THIRD SIGNAL PROPORTIONAL TO THE DIFFERENCE BETWEEN THE STEEPNESS OF THE FLAREOUT PATH AT SAID PREDETERMINED ALTITUDE AND THE INSTANTANOUS STEEPNESS OF THE FLARE-OUT PATH BELOW SAID PREDETERMINED ALTITUDE, (D) AND AUTOPILOT MEANS RESPONSIVE TO SAID REFERENCE ATTITUDE SIGNAL FOR CONTROLLING SAID CRAFT ABOVE SAID PREDETERMINED ALTITUDE AND RESPONSIVE TO SAID REFERENCE ATITUDE SIGNAL AND SAID SECOND AND THIRD SIGNALS FOR CONTROLLING SAID CRAFT BELOW SAID PREDETERMINED ALTITUDE, SAID REFERENCE ATTITUDE SIGNAL AND SAID THIRD SIGNAL BEING OF A SENSE SUCH THAT THEY MUTUALLY OPPOSE ONE ANOTHER, WHEREBY THE PATH OF SAID CRAFT BELOW SAID PREDETERMINED ALTITUDE IS CONTROLLED PRIMARILY BY SAID SECOND SIGNAL WITHOUT OPPOSITION FROM SAID PITCH ATTITUDE REFERENCE SIGNAL.