Weathercocking simulating means for grounded aviation trainers

摘要

638,168. Ground trainers. LINK AVIATION. Inc. May 30, 1947, No. 14404. Convention date, May 31, 1946. [Class 4] In order to simulate the weathercocking of an aircraft in flight, a ground trainer having dummy rudder pedals, by the actuation of which the fuselage can be turned, is provided with means which are actuated when one of the pedals is relatively rapidly released so as to cause the fuselage to turn for a predetermined time in the opposite sense to that in which it turned when the rudder was actuated. General arrangement.. The invention is shown as applied to a trainer of the type described in Specifications 370,128 and 481,375 and in which the dummy rudder pedals 256 actuate a valve 322 controlling the motor which rotates the fuselage to simulate turning, and also a centring valve 279 and bellows 267,275 simulating rudder control loading or feel, as described in Specification 611,560. The weathercocking control unit 339 is operated by a link 344 connected to a second link 310 associated with the rudder control valve 322. The unit 339 is connected by a link 482 to a weathercocking control valve 488, which in turn is connected by pipes 520,534 to a weathercocking shut-off valve 528. The latter communicates by pipes 544,550 with the fuselage turning motor, and its outer leaf is operated by a solenoid 576 controlled by a microswitch 592 associated with the rudder centring valve 279. Operation. Assuming that the pupil operates the right rudder pedal, the links 310, 344 are moved forwardly, the former operating the rudder valve 322 to cause turning of the fuselage in the appropriate direction. The micro-switch 592 is closed to energize the solenoid 576 and close the weather-cocking shut-off valve 528, so that movement of the weather-cocking control valve 488 resulting from the pedal movement has no effect on the turning motor, and the normal rotation of the fuselage results. Should the pupil, in bringing the fuselage out of the turn, release the right pedal too rapidly, the bellows 267, 275 will quickly return the pedals 256 to their neutral position, and at the same time the link 310 moves rearwardly, moving the links 466, 482 to open the weather-cocking control valve 488. The movement of the rudder centring valve 279 resulting from release of the pedal opens the micro-switch 592, thus de-energizing the solenoid 576 and opening the weather-cocking shutoff valve 528, to cause the turning motor to rotate the fuselage to the left. This movement is limited by an electric motor in the unit 339, which is energized when the fuselage commences to turn to the left, to gradually close the control valve 488 and the connection 520 to the turning motor, and thus bring the fuselage to rest. If the pupil releases the pedal gradually, as should be done when correctly coming out of a turn, the link 466 between the control unit 339 and the control valve 488 does not move, and weather-cocking rotation of the fuselage to the left will not occur.