Patent GB-623573-A (GB)
Title: Aviation trainer
IPC: G09B9/20
Filed: 1946-09-16
Abstract: 623,573. Aviation trainers. LINK AVIATION DEVICES, Inc. Sept. 16, 1946, No. 27753. Convention date, Sept. 29, 1945. [Class 4] A ground trainer of the type comprising a fuselage mounted for reproducing turning, pitching and banking movements as described in Specifications 370,128 and 481,375, is arranged to simulate secondary flight characteristics, i.e. changes in pitching, banking and turning attitudes produced otherwise than by actuation of the main controls. Thus a dummy engine throttle lever is so arranged as to produce variations in the attitude of the fuselage as the result of its movement, and the effect of air-speed on performance is also simulated, as are inherent transverse stability and hunting. In the form illustrated the trainer is provided with bellows arranged to simulate the control loading or " feel " on aircraft controls, as in Specification 611,560, dummy engine throttle and propeller governor control levers 465, 521 respectively (Fig. 4), an altitude control unit 561, manifold pressure unit 483, and air-speed unit 645 (Fig. 6). Turning due to power variation.-The dummy throttle lever 465 is connected to the rudder centring valve 279 through a link 471, a bell-crank 474a controlled by dashpots 477, and links 303, 304, 306, the connections being such that the fuselage turns to the left or right, according as the lever 465 is moved forwardly or rearwardly. A similar effect, although ot smaller magnitude, results from movement of the propeller governor control lever 521. Effect of power variation on pitching.-The dummy control levers 465, 521 are arranged to operate the elevator valve 115 through links 853, 859, 696, 700, 705, the nose of the fuselage being raised or lowered with forward or rearward movement, respectively, of the levers. Manifold pressure unit.-The manifold unit 483 is operated by the throttle lever 465 through a link 481, and by the propeller governor control lever 521, through a link 522 and valve 526. An altitude tank is in communication with the capsule 560 of the altitude control member 561, the capsule controlling an electric motor 568 operating the manifold pressure valve 585 through a link 583. The valve 585 is connected to the capsule 551 of the manifold unit 483. Air-speed unit.-The air-speed unit 645 is controlled by a valve 616 through a link 597, the position of which is governed by the manifold pressure unit 483 and the pitching attitude of the fuselage, the valve 616 operating a capsule which in turn actuates the input shaft of a selsyn receiver 640. Mechanical connections are made between the air-speed unit and the wind drift unit, the air-speed control loading regulator bellows, the elevator valve 115, the rudder centring valve 279, the climb-dive valves 730, and a " mush " valve 680. The connection with the wind shaft unit results in appropriate variation of the speed of a recording " crab," and that together with the control loading bellows varies the loading on the pilot's control members in accordance with the assumed air-speed. The connection to the elevator valve 115 is made through the links 690, 700, 705, to raise or lower the nose of the fuselage in accordance with assumed increase or decrease of speed. In the case of the rudder centring valve 279; connection is made through links 302, 304, 306, the fuselage being turned to right or left with increased or decreased airspeed, respectively. The climb-dive valves 730 are actuated to vary the pressure in the altitude tank by links 751, 754 and a compensator spring assembly 755. The "mush" valve 680 is operated by a link 676 to vary the pressure in the altitude tank to simulate the variation in rate of ascent or descent in accordance with air-speed. Transverse stability.-Simulation of the inherent transverse stability of an aircraft is effected by the aileron control loading bellows, which tend to return the control wheel to its neutral position when released from a displaced position. Hunting.-The damped vertical oscillations resulting from the release of the elevator control when the machine has been brought into a diving position are simulated by the combined effects of the movements of the leaves of the elevator valve 115 and the delayed operation of the air-speed unit 645. Specifications 484,243, 561,835 and U.S.A. Specification 2,358,018 also are referred to.