GB806030A - Improvements in or relating to controlling aircraft - Google Patents

Abstract

806,030. Controlling jet-propelled aircraft. ROLLS-ROYCE Ltd. Aug. 3, 1954 [Aug. 25, 1953], No. 23494/53. Class 4. [Also in Group XXVI] An aircraft of the kind in which control is effected by jets of gas emitted from the aircraft, comprises an auxiliary jet nozzle arrangement including at least one nozzle connected to a conduit to be fed with gas under pressure from a pressure source, the nozzle being of variable area and the thrust developed by the jet of gas flowing from the nozzle being controlled by variation of the area of the nozzle. In the aircraft shown in Fig. 1 the gas turbine engines 14 are adjustably mounted so that their jet pipes 15 are vertical for take-off and at, say, 30 degrees to the vertical for level flight. Air is tapped off from the compressors of the engines and led through a distribution pipe 22 and conduits 23, 24, 25 to downwardly-directed nozzles 26, 27, 28 ; these nozzles are all similar and comprise a valve casing 30, Fig. 3, connected to one of the conduits 23, 24, 25 and having a downwardly-facing outlet 32, and a pair of pivoted flaps 29. The rear of each flap 29 is hollow and is open to a space 30a which is vented round the flap hinge to the pressure of the gas within the nozzle so that the flap is pressure-balanced. Each nozzle is operated by an electric actuator in response to control signals produced either manually or by an automatic pilot or by a combination of the two. The two flaps 29 of each nozzle are geared together for simultaneous operation and are arranged so that under equilibrium conditions each nozzle is one third open ; the control system is preferably arranged so that the total lift from the nozzles remains constant. Fig. 5 shows an automatic pilot for controlling the areas of the nozzles. A triangular plate 40 is mounted in a gimbal structure stabilized by an air-driven gyroscope 39 ; the casing 41 is fixed relative to the aircraft and has a domed portion 41a relative to which the plate 40 moves on change of attitude of the aircraft. The domed portion 41a is provided with three nozzle pieces 42 each having formed in it a row of, say six, jets 43 fed with compressed air. Each jet blows on to a corresponding electric switch, except when intercepted by the plate 40. When the triangular plate 40 moves from the equilibrium position, various of the electrical switches are operated and are made to act, through a servo-mechanism (not shown), to cause the electrical actuators to adjust the nozzles 26, 27, 28 to cause a control moment to restore equilibrium. The casing 41 may be manually adjustable to provide for manoeuvring the aircraft, or alternatively the gyroscope 39 may be over-ridden by a manual control 51. In an alternative arrangement, the aircraft is provided with two control nozzles, one at each wing-tip, of the form shown in Fig. 9 ; the nozzles are arranged vertically to produce a net upward or downward thrust according to the position of the valve 67 which adjusts differentially the areas of the outlets 65, 66.