GB1335848A - Apparatus for measuring the angle of attack of an aircraft - Google Patents

Abstract

1335848 Measuring aircraft angle of attack electrically SPERRY RAND CORP 28 Oct 1970 [31 Oct 1969] 51215/70 Heading G1N Apparatus for measuring the angle of attack, α, of an aircraft comprises accelerometers 10, 11 sensing orthogonal accelerations a x , a z along longitudinal and vertical axes respectively, lying in the plane of symmetry XZ of the aircraft, which accelerations produce signals to an analogue computer wherein they are combined with a voltage source representing gravitational acceleration, g; pitch angle, # G ; roll angle #; acceleration #V T along the flight path; and flight path angle γ w with respect to relative wind Ve to yield the angle of attack α according to a given law. In Fig. 5 (not shown) the derived angle of attack, α, is combined with signals representing a x , a z , #, # G , g to generate the signal representing #V T . In Fig. 6 (not shown) the signal representing γ w is produced by a computer utilising signals representing a x , a z , #, # G , g and #h, #h, where #h is vertical speed derived from a borometric instrument. Figs. 7a, 7b (not shown) illustrate the combination of Figs. 4, 5 and 6. The computers include filters of specified time constants to cause the derived signals to have desirable frequency characteristics.