Air traffic control system

Claim 1

IN A SYSTEM FOR CONTROLLING AN AIRCRAFT TO ADHERE TO A SCHEDULED FLIGHT ALONG A PREDETERMINED ROUTE, THE AIRCRAFT HAVING A PREDETERMINED PROFILE SPECIFYING VARIATIONS IN AIR SPEED AND ALTITUDE ALONG THE PREDETERMINED ROUTE, SAID SYSTEM INCLUDING MEANS FOR GENERATING A POSITION SIGNAL CONTINUOUSLY REPRESENTING THE POSITION OF THE AIRCRAFT, THE COMBINATION COMPRISING: FIRST MEANS RESPONSIVE TO AN APPLIED START SIGNAL FOR PRODUCING A FLIGHT SIGNAL IN SIMULATED FLIGHT TIME REPRESENTING THE MOVEMENT OF THE AIRCRAFT ALONG ITS ROUTE ACCORDING TO ITS PROFILE, WITH COMPENSATION BEING MADE TO ADJUST FOR THE EFFECT OF WIND ALONG THE AIRCRAFT ROUTE, SAID FIRST MEANS INCLUDING CIRCUITS FOR CONTROLLING THE RATE OF CHANGE IN AMPLITUDE OF SAID FLIGHT SIGNAL IN ACCORDANCE WITH THE AIR SPEED OF THE AIRCRAFT SPECIFIED BY ITS PROFILE AND IN ACCORDANCE WITH THE INFLUENCE OF WIND ALONG THE ROUTE OF THE AIRCRAFT; A SECOND MEANS, OPERABLE IN SYNCHRONISM WITH SAID FIRST MEANS, FOR PRODUCING A SIGNAL INDICATING THE OCCURRENCE, AFTER SAID START SIGNAL, OF A SIMULATED FLIGHT TIME CORRESPONDING TO THE SCHEDULED TIME REMAINING FOR THE AIRCRAFT TO ARRIVE AT A PREDETERMINED POINT ON ITS ROUTE; THIRD MEANS COUPLING SAID FIRST AND SECOND MEANS AND RESPONSIVE TO THE SIIGNALS PRODUCED THEREBY FOR TRANSLATING THE SIGNAL OF SAID FIRST MEANS INTO AN OUTPUT SIGNAL INDICATING THE PROPER POSITION FOR SAID AIRCRAFT ACCORDING TO ITS SCHEDULE; AND FOURTH MEANS COUPLED TO SAID FIRST AND SECOND MEANS AND RESPONSIVE TO THE SIGNALS PRODUCED THEREBY AND TO SAID POSITION SIGNAL FOR PRODUCING A TIMING SIGNAL, INDICATING THE APPROXIMATE COIUNCIDENCE IN POSITION REPRESENTED BY SAID POSITION SIGNAL WITH THAT REPRESENTED BY A SAID FLIGHT SIGNAL, THE TIME BETWEEN SAID TIMING SIGNAL AND SAID START SIGNAL CORRESPONDING, IN SIMULATED TIME, TO THE ACTUAL TIME REMAINING TO FLY FOR SAID AIRCRAFT ALONG ITS ROUTE; SAID FOURTH MEANS FURTHER INCLUDING MEANS FOR PRODUCING AN OUTPUT SIGNAL REPRESENTING THE DIFFERENCE BETWEEN THE ACTUAL TIME REMAINING FOR FLIGHT AND THE SCHEDULED TIME REMAINING FOR FLIGHT FOR SAID AIRCRAFT.