GB819456A - Steering and horizon indicating instrument for aircraft - Google Patents

Abstract

819,456. Aircraft instruments. COLLINS RADIO CO. May 27, 1957 [Oct. 23, 1956], No. 16763/57. Class 4. [Also in Group XL(c)] An aircraft instrument comprises a front supporting member 10 with a circular opening, a disc 18 concentric with the opening, marked with a horizon bar 19 on one diameter and a reference mark 20 on a perpendicular diameter, and rotated in accordance with the angle of roll, a pitch indicator 22 mounted in front of the disc on a pivot arm 32 and displaced vertically in accordance with the angle of pitch, a guide-slope pointer 12 displaceable vertically, and a steering indicator needle 23 mounted in front of the disc and guide slope pointer, pivoted at the bottom of the supporting member 10, and moved in response to a steering command signal. The horizon bar and pitch indicator are actuated through servo-loops by a vertical gyro 55, the mechanical transmission to the pitch indicator arm 20 being through a cam 49 and follower 47 shaped so that the deflection of indicator 22 is reduced in the higher pitch ranges. The guide slope pointer 12 is actuated by a guide slope receiver 50 and a d.c. movement 17. If the pilot " flies " the indicator 22 onto the pointer 12, the guide-slope path is approached asymptotically. A knob 14 actuates a device 13 to transmit a pitch trim signal to the steering computer 66. Pitch reference marks 35, 37 ard provided on a fixed mask 11, and roll reference marks 33, 38 on a fixed mask 34. The steering needle 23 is operated through a d.c. movement 21 by the steering computer 66, which has inputs from a stabilized magnetic compass 76, the vertical gyro 55, a heading selector 78, a navigation receiver 59, and the pitch trim device 13, the needle 23 being operated to indicate the sense and extent which the aircraft must be banked to maintain course or follow a radio flight path. A knob 15 operates a switch 34 controlling the steering computer to select I.L.S. operation or selected heading operation. Flags 54, 58, 62 and 64 monitor the various electrical components.