GB754405A - Apparatus for landing aircraft - Google Patents

Abstract

754,405. Shortening landing run for aircraft. GOODYEAR TIRE & RUBBER CO. Aug. 27, 1954 [April 13, 1954], No. 24933/54. Class 4. Means for shortening the landing run of aircraft comprise apparatus for sensing complete touch - down and mechanism operated by the sensing means for quickly raising the landing flaps to transfer the weight of the aircraft from the wings to the landing wheels and applying the wheel brakes. Additional apparatus may be used to automatically depress the elevators to further reduce wing incidence and lift. The flaps 9 are connected by linkwork 12, 13 to an hydraulic motor 14 controlled by the pilot for normal operation of the flaps. Aft of the motor 14 the rod 13 is pivotally connected to one end of a lever 15, mounted on a fixed pivot 16 and connected at its other end to a pistonrod 22 of a jack 20. The cylinder of the jack is connected by a pipe 28 to a solenoid-operated valve 27 which places the cylinder selectively in communication with a pipe 26 connected to a pump 24 or a pipe 30 exhausting into a liquid reservoir 25. A branch pipe 40 from pipe 28 and pipes 42, 43 place the brakes on the landing wheels 2, 3 in communication with the pump 24. Micro switches 32, 33, 34 actuated by cams 35, 36, 37 on the respective landing legs 5, 6, 7 are placed in series through a power source 38 and an arming switch 39 with the solenoid 31 on the valve 27 so that on complete touchdown as sensed by partial compression of all undercarriage shock absorbers the solenoidoperated valve places the jack 20 in communication with the pump 24 whereby the flaps 9 are retracted rapidly to reduce wing lift and increase the wheel loading so that the brakes may be applied automatically more heavily than would otherwise be possible. An additional mechanism (Fig. 1A, not shown), is described for simultaneously lowering the elevators to cause the aircraft to pitch downwardly on landing to effect a reduction of wing lift additonal to that caused by raising the flaps. To facilitate such downward pitching the shock absorber of the nose undercarriage may be made relatively soft. Two alternative arrangements for introducing the operation of the jack 20 into the flap-operating linkwork and an electrically-operated jack arrangement are described.