GB975033A - - Google Patents

Abstract

975,033. Aircraft instruments. ELLIOTT BROS. (LONDON) Ltd. Aug. 15, 1963 [May 17, 1962], No. 19121/62. Heading B7W. [Also in Division G1] A system for indicating the performance of an aircraft engine in which data relating to different variables has to be analysed, comprises a computer 1, 2, 3 whose output signal represents the sum of any departures of the variables from respective predetermined reference values and an indicating- instrument 6 responsive to this signal to indicate whether the sum exceeds a predetermined safe value. The computer comprises a section 1 which receives signals representing each variable and reduces them to a common denominator, e.g. electric current to feed a comparison section 2, also fed from a flight plan unit 4 with signals representing the required performance of the engine, after which any error signals are added in section 3 irrespective of sign. A lamp corresponding to each variable will flash if its error signal is excessive and if a corresponding switch 7 is pressed, the instrument 6 will be fed from that source alone and its translucent dial will be illuminated over the appropriate tolerance band for that signal. The flight plan may be pre-recorded on punched or magnetic tape. Servo-mechanism controlled by the computer may be brought in to correct any excessive error and may shut off the engine if the error is excessive. To monitor the performance of several engines the computer may be switched electronically from one engine to another and should one engine show too great an error signal, the computer may be held on that engine, while a stand by computer takes over for the remaining engines.