859,130. Controlling aircraft. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. April 11, 1958 [April 15, 1957], No. 11614/58. Class 4. In a vertical take off and landing an aircraft, a connection between a pilot's control member and means for creating a torque on the aircraft by fluid jet reaction, comprises a dashpot and the torque creating means is subjected to the action of a spring urging the means to a neutral position. In Fig. 3, a lug 1 secured to a rotatable pilot's control member is connected through rod 9, lever 10, and rod 11 with a slider 12 in a fixed slideway 13. A triangular framework consisting of rods 14, 15, and a dashpot 6, is articulated at one apex to the slider 12, and at a second apex 17 to a rod 19 pivoted to a lever 20 on a valve 3 distributing compressed air between ducts 7, 7<SP>1</SP>, 8 and 81, and normally centred by springs 4, 5. The third apex 18 is linked by rod 21 to the throttle lever 23 of a gas turbine engine. Rotation of lug 1 from its neutral position displaces the slider 12 and lever 20, admitting compressed air either through ducts 7, 8 or ducts 7<SP>1</SP>, 81, to nozzles disposed so that the aircraft is rotated about its longitudinal axis in a sense determined by the sense of rotation of lug 1. An angular acceleration is thus imparted to the aircraft. The force set up by springs 4, 5 gradually extends or contacts the dashpot, lever 20 returning to the neutral position, and cutting off the compressed air. The aircraft thus acquires a certain steady angular velocity dependent on the displacement of lug 1. On returning the lug to neutral, lever 20 is deflected so as to impose an opposite torque on the aircraft, and is again gradually returned to neutral, the dashpot re-attaining its previous length, and the angular velocity acquired by the aircraft will be exactly cancelled. When the gas turbine throttle lever 23 is moved, after disengaging a stop 26 from a toothed quadrant 25 by a button 27, the triangular framework is pivoted by rod 21 about the slider, deflecting lever 20 until the springs restore it to neutral. The arrangement is such that the resulting discharge of compressed air nullifies the angular velocity that the aircraft would acquire due to speeding up or slowing down of the rotating parts of the gas turbine. In Fig. 4, a universally mounted control column 31 has a first lever 33 connected by rod 38, lever 43, and dashpot 44 to a rod 50 acted on by a fixed double acting spring 45, and operating differentially two valves 46, 47 in compressed air ducts leading to opposed fluid injection spoilers 54, 55 on the gas turbine exhaust nozzle. A second lever is connected by through members 39, 40, 41, and 42 to a rod 51 operating differentially valves 48, 49 controlling opposed spoilers 52, 53. The arrangement is such that on moving the control column in any direction, the opposed pairs of spoilers are actuated differentially to set up a torque such that the aircraft tilts about the required axis, taking into account gyroscopic effects caused by the presence of rotating parts in the aircraft. In Fig. 5, similar spoilers are actuated by the pilot's reflex movements in maintaining his balance, to stabilize the ascent or descent of the aircraft. The pilot stands on a platform 56 mounted on a fixed ball 57. A second platform below ball 57 is connected to the first by a dashpot 62 and spring 63, and is rigid with a rod 60 held by the pilot's arm 59. The two platforms are connected by a linkage through dashpot 64 and spring 65 to a differential compressed air valve 46. The reflex movements of the pilot in retaining his balance act on valve 46 so that correcting torques are applied when the aircraft tilts.