Patent GB-1209922-A (GB)
Title: Display system for providing integrated display of aircraft information
Inventor: CONGLETON PAUL C
IPC: B64D45/00
Filed: 1967-10-06
Abstract: 1,209,922. Aircraft instruments. KAISER AEROSPACE & ELECTRONICS CORP. 6 Oct., 1967 [10 Oct., 1966], No. 45892/67. Heading B7W. [Also in Division H4] An aircraft display system for presenting command attitude, actual attitude and horizontal situation information on an integrated display in an aircraft comprises an electronic display means (e.g. a cathode-ray display tube) on which a command symbol is produced under the control of signals from a command signal generator which in response to input signals effects vertical and lateral displacement and roll of the command symbol, the display also including, a horizon symbol, produced under the control of signals derived from an attitude generator responsive to the actual attitude of the aircraft together with a line symbol produced under the control of signals from a course line generator and indicative of the horizontal situation with respect to a desired course. The command signal generator is operative in response to command signals indicative of desired changes in pitch attitude, de crab action and roll attitude to move the command symbol vertically, laterally and about its roll axis respectively, the horizon symbol being rotated about the roll axis to indicate the actual roll and moved vertically to indicate the actual pitch attitude. The invention thus provides an integrated display which is equivalent to that provided by two separate known units such as a coarse indicator and flight director (Fig. 1 and 2, not shown). The display also includes a heading scale produced under the control of a heading generator, one end of the course line symbol being positioned on the heading scale at the selected heading and maintained thereon despite vertical movement of the horizon symbol and the other end of the course line symbol extending towards the bottom of the display, the heading scale moving with change in heading so that the actual heading is at the centre of the heading scale. Cource error is then indicated by lateral movement of the end of the course line symbol near the bottom of the display. A reference path which moves along the course line symbol to display distance from a reference point as the aircraft moves forward is also produced on the display such reference path emanating from the horizon symbol in the direction of the bottom of the display as the aircraft approaches the reference point and the horizontal width decreasing as it approaches the horizon symbol to give an illusion of perspective. Fig. 3A shows the basic display which includes a sky plane 52 separated from a ground plane 54 (which may be shaded to simulate depth perspective) by the horizon line symbol 50 adjacent to which is the azimuth heading scale 68 which is "displaced" along the horizon line to bring different calibration numerals into view in accordance with changes in aircraft heading a reference "lubber" line 70 being associated with this scale. The display, additionally, includes the command symbol 58, a fixed reticle 56, the course centre line 72 and the reference path (runway) 73 with associated course deviation scale 74 reference pitch lines 60 (displayed in black above the horizon and in white below the horizon) and a roll scale 62 with co-operating roll pointer 64. Other information displayed comprises glide slope deviation 89, radar altitude 82 (which is only displayed at altitudes of less than 1500 feet) and compass markers 86, 88 (which are only displayed above 1500 feet) the former (white) indicating the heading of the captain's compass are the latter (black) indicating the heading of the flight officers compass, any error in either compass which causes a difference in the two headings resulting in horizontal movement of the flight officers index and allowing the difference to be determined by reference to the azimuth heading scale 68. Conventional course and heading select knobs and indicators &c. and failure warning indicators are also provided on the front of the display panel. Figs. 3B-3F show examples of the displays presented to the pilot during an 1LS approach after the runway heading e.g. 252, has been set up in the equipment by the course selector knob 76 (Fig. 3A) and the flight director computer has selected e.g. course 232 to intercept such heading. In these Figures pictorial representations of the horizontal situation of the aircraft (as viewed from above) are shown above each display and the attitude of the aircraft is shown below each display. As the displays change the pilot manoeuvres the aircraft to maintain the flight command symbol (white) in co-incidence with the fixed reticle (black). As the altitude decreases to below 1500 feet the compass comparator symbols are removed and the radar altitude symbol is produced and as the altitude decreases still further the pitch lines and then the glide slope and radar altitude symbols are removed so that the pilot has an uncluttered display during the critical moments of landing. The invention is stated to be also useful with mobile craft such as submarines. Details of the circuitry for the production and motion of the symbols are given.