GB748789A - Apparatus for determining the available flight range of an aircraft - Google Patents

Abstract

748,789. Electric indicating systems. SVENSKA AEROPLAN AKTIEBOLAGET. July 20, 1953, No. 20037/53. Class 40(1) Apparatus for determining the available flight range of an aircraft comprises an electric calculating circuit embodying potentiometers variable in response to the fuel carried by and the altitude of the aircraft which produces an output signal, dependent on the flight range at a predetermined fuel consumption rate set into the computor, and corrected for altitude, actuating the deflection system of a C.R. oscillograph through a phase splitting circuit to display a ring-shaped trace whose radius is a function of the available flight range. A D.C. energized inverter 4 generates an alternating voltage energizing a potentiometer 6 varied by the fuel gauge 7 in response to the quantity of fuel remaining in tank 19 to apply a corresponding voltage through an impedance matching circuit 8 to a potentiometer comprising a fixed resistance 12 representing a predetermined fuel consumption rate in series with a variable resistance 10 whose slider is adjusted by the altimeter 11 to produce a voltage proportional to the remaining flight range which is applied through an amplifier 13 to a phase shifter 14 which derives two voltage components in quadrature applied to the X and Y plates 16, 18 and 15, 17 of a cathode ray tube to produce a circular display whose radius is proportional to the available flight range. A transparent map or scale may be placed over the tube screen, and cyclically operated automatic switching device 23 alternatively energizes the deflection plates from the flight range voltages and from the X and Y voltages of a position co-ordinate computor 24 which may be of the kind described in Specification 748,641 whereby a spot indicative of the position of the aircraft is superimposed on the available flight range ring trace. Specification 748,819 also is referred to.