Ground-based flight training or simulating apparatus

Claim 1

A FLIGHT TRAINING OR SIMULATING APPARATUS FOR SIMULATING A SPECIFIC AIRCRAFT TYPE, INCLUDING A CONTROL MEMBER WHICH IS OPERABLE MANUALLY, COMPUTING MEANS FOR DETERMINING A FIRST ELECTRICAL QUANTITY REPRESENTING THE FORCE REQUIRED TO LOAD THE CONTROL MEMBER, FIRST ACTUATOR MEANS ADAPTED TO APPLY FORCE TO THE CONTROL MEMBER AND RESPONSIVE TO SAID FIRST ELECTRICAL QUANTITY BELOW A PREDETERMINED FREQUENCY, AN OUTPUT FORCE SENSING DEVICE THE OUTPUT OF WHICH IS A SECOND ELECTRICAL QUANTITY REPRESENTING THE MAGNITUDE OF THE FORCE APPLIED BY THE FIRST ACTUATOR MEANS TO THE CONTROL, SAID FIRST ACTUATOR MEANS AND SAID OUTPUT SENSING DEVICE BEING ELECTRICALLY CONNECTED IN SUCH A WAY THAT THE OPERATION OF THE FIRST ACTUATOR MEANS IS CONTROLLED BY A QUANTITY REPRESENTING THE DIFFERENCE BETWEEN THE FIRST AND THE SECOND ELECTRICAL QUANTITIES, SECOND ACTUATOR MEANS FOR PRODUCING A FORCE PROPORTIONAL TO THE MAGNITUDE OF AN ELECTRICAL QUANTITY ABOVE SAID PREDETERMINED FREQUENCY APPLIED TO ITS INPUT AND RESPONSIVE TO SAID QUANTITY REPRESENTING THE DIFFERENCE BETWEEN THE FIRST AND SECOND ELECTRICAL QUANTITIES, MIXING LINKING MEANS RESPONSIVE TO THE OUTPUT FORCES OF SAID CONTROL MEMBER, AND ACTUATOR MEANS FOR LOADING SAID CONTROL MEMBER, AND FEEDBACK MEANS CONNECTED TO SAID COMPUTING MEANS AND RESPONSIVE TO THE DISPLACEMENT OF SAID CONTROL MEMBER FOR PROVIDING A CLOSED LOOP SYSTEM WHEREBY THE COMBINED FORCE ON THE CONTROL MEMBER VARIES IN SIMULATION OF THE STEADY STATE AND TRANSIENT FORCES CHARACTERISTICS OF THE AIRCRAFT.