GB673870A - Improvements in or relating to rotary wing aircraft - Google Patents

Abstract

673,870. Rotary-wing aircraft. FAIREY AVIATION CO., Ltd., BENNETT, J. A. J., and FORSYTH, A. G. Oct. 18, 1950 [Sept. 7, 1949], No. 23199/49. Class 4 A rotary wing aircraft provided with reaction jet means for driving the sustaining rotor has two or more rotary compressors arranged to feed a common source of supply of compressed air constituting the working fluid for the jet means, gas turbine units being connected respectively to the compressors to drive them, and has at least one propeller, one of the power units driving that propeller. In the embodiment, shown in Fig. 4, stub wings 13, 14 carry turbines 17 which drive compressors 18 and propellers 19. Air is taken from the compressor via valves 24 and pipes 23 to a distributor 21 and thence through ducts 20 to driving jet units mounted on rotor blades 11. In a further embodiment, shown in Fig. 5, an additional turbine drives a compressor 27 which also supplies air, through a duct 28, to the distributer 21. A non-return valve 25 at the entry of each duct 23, 28 to the distributer ensures that should one air supply fail the rotor may still operate. Fig. 8 illustrates the control system for the embodiment shown in Fig. 5. The throttles 39. 40 of theoutboard turbines 16, 15 are operated, through differential units 41, 42, by means of hand levers 43, 44 or by means of a foot-bar 47 pivotally mounted at 48. The air valves 24 are connected by a link 49 and are operated by a hand lever 50. A hand lever 53 controls the throttle 51 of the turbine 26 independently of the other controls. The differential unit 42 comprises crown wheels 57, 59, Figs. 11 and 16, connected by arms 56, 58 and links 55, 46, respectively to the throttle lever 44 and the footbar 47. The crown wheels 57, 59 are engaged by pinions 61, 62 mounted on a carrier 60 which is connected by a lug 63 thereon and a linkage 64 to the throttle 40. The control levers 50, 43 and 44 are operatively interconnected by means of a gate 65 and a gating bar 66 whereby when changing from hovering to forward flight the lever 50, in being moved to cut off the air supply to the rotor (which then anti-rotates), simultaneously reduces the power to that required by the propellers for forward flight. By differential control of the thrust of the two propellers, the aircraft may be controlled in yaw. The differential control may be applied to the pitch of the propellers or to the engine throttles as shown.