Patent GB-850103-A (GB)
Title: Improvements in or relating to control systems for aircraft
IPC: B64C29/00
Filed: 1957-12-20
Abstract: 850,103. Controlling aircraft. RECHERCHES ETUDES PRODUCTION R. E. P. Dec. 20, 1957 [July 12, 1957 ; Oct. 29, 1957], No. 39742/57. Class 4. [Also in Group XXIX] An aircraft is controlled by a conventional aerodynamic control surface system, and a fluid jet reaction control system, the two systems being responsive to the same input control members, and a device response to the dynamic pressure is arranged to vary the effectiveness of the fluid jet reaction control system. Fig. 1 shows two downwardly directed jet nozzles 101, 102 at the leading edges of the wing tips, two similar nozzles 103, 104 at the trailing edges of the wing tips, and two laterally directed nozzles 105, 106 at the tail. A control input 109 to distributer 107 controls the relative strength of jets 101, 103 together as compared with that of jets 102, 104 for roll control, a control input 110 controls the relative strength of jets 101, 102 together as compared with that of jets 103, 104 together for control in pitch, and a control input 111 controls the relative strengths of jets 105 and 106 for control in yaw. The input controls 109, 110, 111 may be mechanical electrical, or hydraulic, and are connected to pilot's control members and to the conventional aerodynamic controls (not shown). The distributer 107 is fed with compressed gas through a duct 14 containing a valve 113 biassed to the fully open position by a spring 114, and subject to the pressure in a dynamic pressure sensor 116, so that during e.g. a vertical take-off, the valve is fully open and the jet reaction controls are fully effective, but as the airspeed increases, the valve closes and the jet reaction controls become progressively less effective becoming fully ineffective at Mach 0.3. The valve may have any desired dynamic pressure/airflow characteristic. In the embodiment of Figs. 3 and 4 (not shown) and 5, movement of the control column in the sense to adjust the elevators actuates a duplicated hydraulic jack, the two sections of which are supplied by independent hydraulic circuits arranged so that failure of a hydraulic circuit renders the coresponding jack section by-passed. The jack moves the elevators and also adjusts ganged butterfly valves 29, 229 in ducts 30, 230 leading from a common compressed gas duct 11 to ducts 12, 212 feeding two downwardly pointing nozzles, one located forward and one aft, so that the jack varies differentially the gas supply to the nozzles resulting in a pitching moment. Similarly, one of the jacks controlling the ailerons also varies differentially the gas supply to two downwardly pointed nozzles, one located each side of the aircraft centre line, and the jack controlling the rudder also varies differentially the gas supply to two rearwardly pointing nozzles, one located each side of the aircraft centre line. The gas supply is again regulated by a dynamic pressure responsive valve as in Fig. 1. The jacks may have an electrical instead of a mechanical input, and may have a second electrical input for flight stabilization signals. The directions other than the thrusts of the gas streams may be varied differentially by the pilot.