GB747358A - Improvements in or relating to aircraft instruments - Google Patents

Abstract

747,358. Aircraft indicating instruments. KUZYK, W., and WHITTLEY, D. C. Nov. 10, 1953 [Dec. 16,1952], No. 31185/53. Class 4. An instrument unit to facilitate the economical operation of jet-propelled aircraft comprises a standard altimeter 10 and Machmeter 11 mounted on a panel 12. The altimeter has a needle 10a indicating altitude on a circular scale 10b and the Machmeter has a needle 11a indicating Mach number on a circular scale 11b, both scales being on the panel 12 and both instruments are connected by a pipe 13 to a static head (not shown) and the Machmeter is connected by a pipe 14 to a pitot head (not shown). A transparent disc 15, having a pointer 21 inscribed thereon, is mounted in front of the scale 10b by a bezel ring 16 which is enclosed by an annular rim 17 formed with a peripheral flange 17b carrying a scale 22 graduated in pounds representing the weight of the aircraft. The inner face of the ring 16 has bevel teeth meshing with a pinion 19 driven by a computer 23 which is electrically connected to a fuel-flow meter 24 and a counting device 25 responsive to the expenditure of ammunition or other disposable load. The Machmeter has a rim 30 and a bezel ring 29 similar to the elements 17 and 16 of the altimeter. The peripheral flange of rim 30 has a scale graduated in units of w/p. (weight of aircraft in pounds to atmospheric pressure in 1b/sq. inch) indicated by a pointer 27 on a transparent disc 28 secured in the bezel ring 29 and rotated by a computer 32. Knobs 26 and 33 are provided whereby the initial settings of the pointers 21 and 27 may be manually adjusted before flight. Although the Machmeter has been described as indicating on a single scale required variation of Mach number with w/p. it may be inscribed with a plurality of scales. To effect flight to obtain maximum range, the pilot sets pointer 21 to indicate on scale 22 the initial gross weight of the aircraft and the pointer 27 to indicate on scale 31 the value of w/p. obtained by dividing the initial gross weight of the aircraft by the atmospheric pressure at the airport. The pilot must then climb as rapidly as possible to cruising altitude and then fly the aircraft so that the altimeter needle 10a coincides with the pointer 21 and the Machmeter needle 11a coincides with the pointer 27. The flight path then takes the form of a gradual climb as the fuel is consumed. An alternative flight plan is described for flight at constant altitude. An alternative embodiment is described in which the scales and pointers of the Machmeter and altimeter are represented by two pairs of superimposed cross-lines which have to be maintained in coincidence.