Patent GB-548093-A (GB)
Title: Improvements in or relating to apparatus for training aircraft pilots
IPC: G09B9/30
Filed: 1941-05-27
Abstract: 548,093. Training aircraft pilots. RUTHERFORD, S. H. May 27, 1941, Nos. 6756 and 10468. [Class 4] For training aircraft pilots, a dummy cockpit is fitted with the usual controls and set of instruments which are so connected through various mechanisms controlling an optical projection apparatus that not only are the various manoeuvres simulated by movements of an optical image projected on a screen in front of the pupil but the various instruments give the appropriate readings. The projection apparatus comprises a sphere capable of continuous rotation in either direction about each of the three principal axes, the sphere having a circumferential horizon line dividing landscape from sky. In conditions representing normal horizontal flight one side of the sphere is projected episcopically with the horizon line occupying a central horizontal position on the screen. The various controls and instruments are connected through a series of differential and proportioning linkages to control the speed and direction of three friction wheels which drive the sphere directly or indirectly about its three principal axes. Fig. 3 shows the linkage for controlling the movements of the sphere, about the pitching axis, a more complex linkage being described and shown for controlling the rotations of the sphere about the other two axes. The links 21 .. 25 are connected respectively to the elevator control, air speed indicator, engine speed indicator, tail trimmer, and an inverted flight simulator mechanism which alters the effective mean position of the elevator control. The combined movements of all these links is transmitted through link 30 to a lever 31 pivoted at O to transmit a proportion of the motion to a link 32. The amount transmitted depends upon the position of two links 34, 35 connected respectively to the air-speed and engine-speed indicator mechanisms. The motion of the rod 32 is compounded with that of links 38, 39 connected respectively to a stall indicator mechanism and a taxying simulator and transmitted to a link 42. The link 42 and a link 43 connected to a rough air simulator act through a link 44 upon a rod 45 for controlling the position of a friction wheel 48 upon a disc 47 rotating continuously at a constant speed. The wheel 48 drives a friction wheel 49 in contact with the sphere (not shown). The wheel 49 comprises a series of rollers rotatable about axes in the plane of the wheel so that motion is transmitted to the sphere in the plane of the wheel while permitting free movements of the sphere across that plane. A magnet fixed diametrically within the sphere acts upon four external magnets to control respectively a pitch angle indicator a side slip simulator, a taxying simulator, and a stall simulator. The pitch angle indicator influences the inverted flight mechanism which also is influenced by the air speed indicator and the position of the rod 45 of Fig. 3. The stall simulator is only operative when the air speed falls below a critical value. The air speed indicator is influenced by the engine speed; pitch angle, elevator control, and by mechanism simulating a spin during a stall. The engine speed indicator depends upon the throttle and ignition controls and the air speed indicator. The altimeter is influenced by pitch angle, air speed and side slip simulators, and at zero reading closes a circuit to energize the taxying simulator and another circuit to inhibit the action of the stall indicator. The taxying simulator introduces disturbances only if the sphere is not at the correct angle for a tail down landing on an even keel. The rough air simulator is brought in at will. The cockpit remains still except that it may be joggled when the rough air and taxying simulators are in use. Qwing to the freedom of the sphere to rotate indefinite amounts about any axis, evolutions, such as complete loops and rolls may be simulated.