Height indicating system for aircraft

Claim 1

AN AIRCRAFT HEIGHT INDICATING SYSTEM, COMPRISING MEANS FOR SELECTIVELY DISPLAYING INDICATION OF AIRCRAFT PROXIMITY TO AN INSTRUMENT LANDING GLIDE SLOPE PATH, AS WELL AS AIRCRAFT PROXIMITY TO A LANDING RUNWAY, SAID MEANS COMPRISING A HORIZONTAL MOVABLE POINTER, A DIAL SWEPT BY THE SAID HORIZONTAL POINTER, SAID DIAL PORTRAYING SCALE MEANS COMMON TO GLIDE SLOPE MEASUREMENT, SAID DIAL ALSO PORTRAYING A HORIZONTALLY DELINEATED HEIGHT REFERENCE SCALE, A HORIZONTALLY DISPLAYED CENTRALLY POSITIONED NULL LINE MIDWAY VERTICALLY OF THE SAID DIAL FOR ESTABLISHING THE ZERO HEIGHT PROXIMITY OF THE LANDING RUNWAY TO THE AIRCRAFT, AS WELL AS FOR ESTABLISHING THE LOCUS OF THE AIRCRAFT WITH RESPECT TO THE SAID GLIDE SLOPE PATH, A GALVANOMETER FOR DRIVING THE SAID POINTER, THE SAID GALVANOMETER BEING CONNECTED BY A SWITCHING MEANS TO EITHER THE OUTPUT OF A GUIDE SLOPE RECEIVE OR TO THE OUTPUT OF A RADIO ALTIMETER, A RADIO ALTIMETER, A GLIDE SLOPE RECIEVER, A MARKER BEACON RECEIVER, SAID MARKEER BEACON RECEIVER OUTPUT ACTIVATING THE SAID SWITCHING MEANS TO DISCONNECT THE SAID GLIDE SLOPE RECEIVER FROM THE SAID GALVANOMETER WHEN THE AIRCRAFT TRANVERSES THE ENERGY PATTERN OF A SELECTED GROUND-BASE MARKER BEACON TRANSMITTER AND COUPLING A SIGNAL FROM SAID RADIO ALTIMETER TO SAID GALVANOMETER REPRESENTATIVE OF THE HEIGHT OF THE AIRCRAFT RELATIVE TO THE RUNWAY.