Aircraft instrument systems

Claim 1

A MONITORED AIR DATA SENSOR COMPRISING A STATIC PRESSURE CAPSULE, MEANS ASSOCIATED WITH THIS CAPSULE FOR ANGULARLY POSITIONING A FIRST SHAFT IN ACCORDANCE WITH THE VALUE OF FUNCTION OF THE BAROMETRIC HEIGHT SENSED BY THE CAPSULE, A PITOT-STATIC CAPSULE, MEANS ASSOCIATED WITH THIS CAPSULE FOR ANGULARLY POSITIONING A SECOND SHAFT IN ACCORDANCE WITH THE VALUE OF A FUNCTION OF THE INDICATED AIR SPEED SENSED BY THE CAPSULE, MECHANICAL MEANS INTERCONNECTING THE FIRST AND SECOND SHAFTS WITH A THIRD SHAFT IN SUCH MANNER THAT THE ANGULAR POSITION OF THE THIRD SHAFT WILL BE REPRESENTATIVE OF THE VALUE OF A FUNCTION OF THE MACH NUMBER AND MEANS WHEREBY EACH OF THE THREE SHAFTS MAY BE SELECTIVELY COUPLED TO A PAIR OF ELECTRICAL PICK-OFF DEVICES TO OPERATE THESE IN UNISON AND PRODUCE RESPECTIVE ELECTRICAL SIGNALS WHICH ARE ISOLATED FROM EACH OTHER CHARACTERISED BY THE PROVISION OF A MONITORING STATIC PRESSURE CAPSULE, FIRST TRANSDUCER MEANS ADAPTED TO BE ACTUATED BY THIS MONITORING CAPSULE TO PRODUCE A FIRST ELECTRICAL SIGNAL PROPORTIONAL TO THE MOVEMENT OF THE CAPSULE, MEANS OPERATED MECHANICALLY FROM THE MEANS FOR POSITIONING THE FIRST SHAFT AND ADAPTED TO ACTUATE THE FIRST TRANSDUCER MEANS IN THE SENSE NORMALLY FOR REDUCING THIS SIGNAL PROPORTIONALLY TO THE ANGULAR DISPLACEMENT OF THIS SHAFT, A MONITORING PITOT-STATIC PRESSURE CAPSULE, SECOND TRANSDUCER MEANS ADAPTED TO BE ACTUATED BY THIS MONITORING CAPSULE TO PRODUCE A SECOND ELECTRICAL SIGNAL PROPORTIONAL TO THE MOVEMENT OF THIS CAPSULE, AND MEANS OPERATED MECHANICALLY FROM THE MEANS FOR POSITIONING THE SECOND SHAFT AND ADAPTED TO ACTUATE THE SECOND TRANSDUCER MEANS IN THE SENSE NORMALLY FOR REDUCING THE SECOND SIGNAL PROPORTIONALLY TO THE ANGULAR DISPLACEMENT OF THE SECOND SHAFT WHEREBY THE FIRST AND SECOND SIGNALS BECOME REPRESENTATIVE OF THE DIFFERENCES IN THE FUNCTIONING OF THE STATIC CAPSULE AND MONITORING STATIC CAPSULE AND OF THE PITOT-STATIC CAPSULE AND MONITORING PITOT-STATIC CAPSULE, RESPECTIVELY.