GB1061386A - Aircraft navigation instrument - Google Patents

Abstract

1,061,386. Aircraft navigation instruments. SPERRY GYROSCOPE CO. Ltd. Oct. 14, 1963 [Oct. 17, 1962], No. 39311/62. Heading B7W. An aircraft instrument, particularly for V.T.O.L. aircraft, comprises an artificial horizon 4 with a movable index 10 arranged to be displaced vertically in accordance with the flight path angle of the aircraft. The index 10 moves over graduations, marked 1, 2, 3 (representing tens of degrees) on a gyro ball 2, the flight path angle being derived by dividing rate of climb or descent (obtained by barometric capsule or radio altimeter) by the ground speed. The divisor is held constant below a predetermined ground speed so that the position of the index 10 indicates the rate of descent or climb. Flight directors 8, 9 are provided, and are operated by navigational signals, the aircraft being flown so that they are aligned with a fixed index 1 in level flight, when the movable index 10 may be biased out of view, and intersect over the movable index during the descent. A pointer 6 is also provided to indicate, by its deviation from a mark 7 any error in the flight speed. When landing a V.T.O.L. aircraft, a signal may be applied to the horizontal flight director 9 at a predetermined point to cause the pilot to level out, e.g. 70 feet above the ground, before making the final descent. The movable index may also be arranged, for use during take-off, to be displaced substantially in inverse correspondence with the flight path angle, and a fixed index indicating the desired angle may be provided. The signals to the movable index may also be modified by pitch error signals.