GB747967A - Improvements in craft guidance systems - Google Patents

Abstract

747,967. Automatic steering control systems. BENDIX AVIATION CORPORATION. Jan. 9, 1953 [Jan. 23, 1952], No. 749/53. Class 38(4). As shown, in an aircraft automatic pilot, the output of a glide path radio receiver 10 controls servo-operated elevators through a switch 18, a glide path computer and an amplifier. The D.C. output of a radio range or localizer beam radio receiver 11 controls servo-operated ailerons and rudder through a modulator 20 of the type described in Specification 647,961, [Group XXXIX], an amplifier 8, a signal limiter 54 of the type described in Specification 694,577, and further amplifiers. A circuit including valves 31, 36, 37 and a thermal delay tube 42 of the type described in Specification 603,610, [Group XXXVI], associated with a bridge network, produces a rate component of control to prevent hunting as described in Specification 679,560. As in Specification 675,751 a selector switch 284 is arranged to (a) switch on, at position 282, valve heaters; (b) introduce, at position 285, receiver 11 tuned to range frequency to maintain the craft on course; (c) introduce, at position 286, receiver 11 tuned to localizer frequency to maintain the correct approach; (d) introduce at position 354, glide path receiver 10 also, to maintain the correct descent to land. A data smoother 7 of the type described in Specification 688,443, [Group XL (c)], including a thermal delay tube is introduced by a switch 6a electromagnetically operated by switch 284 to prevent response to transient signals when flying a localizer beam. During each positional change of selector switch 284 a relay 101 is de-energized to charge a condenser 94 so that at the new position the condenser voltage biases amplifier valve 75 to cut off. Aileron and rudder control signals thus become ineffective at first and then gradually become effective as the condenser 94 discharges through a resistance 83. Sudden reaction on the craft due to the change is thereby prevented.