Visual indicating devices for aircraft

Claim 1

A VISUAL INDICATING SYSTEM FOR USE IN AN AIRCRAFT, COMPRISING AN INDICATOR ARRANGEMENT RESPONSIVE TO ANY DEMAND SIGNAL SUPPLIED THERETO TO PROVIDE A MOVING OPTICAL STIMULUS THE RATE AND SENSE OF MOVEMENT OF WHICH IS DEPENDENT UPON THE MAGNITUDE AND SENSE OF THE DEMAND REPRESENTED BY THE DEMAND SIGNAL; MEANS FOR DERIVING AN ALTITUDE SIGNAL VARYING WITH VARIATIONS IN THE HEIGHT OF SAID AIRCRAFT, SWITCHING MEANS SWITCHABLE FROM ONE TO ANOTHER OF THREE STATES AND RESPONSIVE TO SAID ALTITUDE SIGNAL TO BE SWITCHED FROM A FIRST TO A SECOND OF SAID THREE STATES WHEN, AS REPRESENTED BY SAID SIGNAL, THE AIRCRAFT HAS DESCENDED TO A FIRST PREDETERMINED HEIGHT, AND TO BE SWITCHED FROM THE SECOND STATE TO THE THIRD STATE WHEN, AS REPRESENTED BY SAID SIGNAL, THE AIRCRAFT HAS DESCENDED FURTHER TO A SECOND PREDETERMINED HEIGHT; MEANS FOR MONITORING THE POSITION OF SAID AIRCRAFT RELATIVE TO A RADIODEFINED GLIDE PATH; MEANS FOR MONITORING THE PITCH ATTITUDE OF SAID AIRCRAFT; AND COMPUTING MEANS WHICH HAS THREE MODES OF OPERATION AND IS RESPONSIVE TO THE STATE OF SAID SWITCHING MEANS TO ADOPT A FIRST OF THE THREE MODES OF OPERATION WHEN THE SWITCHING MEANS IS IN ITS FIRST STATE, TO ADOPT A SECOND OF THE THREE MODES WHEN THE SWITCHING MEANS IS IN ITS SECOND STATE, AND TO ADOPT THE THIRD MODE OF OPERATION WHEN THE SWITCHING MEANS IS IN ITS THIRD STATE; SAID MONITORING MEANS BEING COUPLED TO SAID COMPUTING MEANS FOR SUPPLYING INPUT SIGNALS TO SAID COMPUTING MEANS RELATED TO THE PARAMETERS BEING MONITORED; SAID COMPUTING MEANS IN ITS FIRST MODE OF OPERATION BEING RESPONSIVE TO AN INPUT SIGNAL DEPENDENT UPON DEVIATION OF THE AIRCRAFT FROM SAID RADIO-DEFINED GLIDEPATH TO SUPPLY TO SAID INDICATOR ARRANGEMENT AS SAID DEMAND SIGNAL A SIGNAL WHICH DEMANDS CHANGE IN AIRCRAFT PITCH ATTITUDE REQUIRED FOR FLIGHT ALONG THE GLIDEPATH, THE COMPUTING MEANS IN ITS SECOND MODE BEING RESPONSIVE TO AN INPUT SIGNAL REPRESENTATIVE OF A MEAN VALUE OF PITCH ATTITUDE APPLICABLE TO FLIGHT ALONG THE GLIDEPATH TO SUPPLY TO SAID INDICATOR ARRANGEMENT AS SAID DEMAND SIGNAL A SIGNAL WHICH DEMANDS CHANGE IN AIRCRAFT PITCH ATTITUDE REQUIRED FOR FLIGHT ALONG AN EXTENSION OF THE GLIDEPATH, AND SAID COMPUTING MEANS IN ITS THIRD MODE BEING RESPONSIVE TO INPUT SIGNALS DEPENDENT RESPECTIVELY UPON THE AIRCRAFT HEIGHT H RELATIVE TO A PREDETERMINED LEVEL AND OF THE AIRCRAFT PITCH ATTITUDE 0, TO SUPPLY TO SAID INDICATOR ARRANGEMENT AS SAID DEMAND SIGNAL A SIGNAL WHICH HAS AT LEAST TWO COMPONENTS AND WHICH DEMANDS CHANGE IN PITCH ATTITUDE REQUIRED FOR FLIGHT OF THE AIRCRAFT IN ACCORDANCE WITH A PREDETERMINED PATH DURING THE FLARE PHASE OF LANDING, A FIRST OF SAID TWO COMPONENTS BEING REPRESENTATIVE OF A PREDETERMINED FUNCTION OF (1+KD)H, WHERE K IS A CONSTANT AND D IS THE OPERATOR REPRESENTATIVE OF DIFFERENTIATION WITH RESPECT TO TIME, AND THE SECOND COMPONENT BEING REPRESENTATIVE OF A PREDETERMINED FUNCTION OF THE PITCH ATTITUDE 0; MEANS FOR SUPPLYING A SIGNAL DEPENDENT UPON THE ANGULAR POSITION OF THE AIRCRAFT ELEVATORS RELATIVE TO THE AIRCRAFT, AND MEANS RESPONSIVE TO SAID ELEVATOR ANGULAR POSITION SIGNAL TO SUPPLY, AT LEAST AS A THIRD COMPONENT OF THE DEMAND SIGNAL SUPPLIED DURING SAID THIRD MODE OF OPERATION, A SIGNAL WHICH IS REPRESENTATIVE OF A PREDETERMINED FUNCTION OF SAID ANGULAR POSITION.