A conformal head-up display for the visual approach

The degree of conformity used in matching a superimposed display to its visual background is considered in relation to the information available for vertical guidance and control during a purely visual approach. The information may be represented by individual symbols or combined in a single symbol, and the relative merits of these methods are discussed. A fully conformal display format is developed for the purpose of showing both the position and direction of the flight path, with provision for the effects of disturbances, ILS compatibility, and control needs. The field of view needed for all conditions and phases of the visual approach with a fully conformal display is studied in relation to the limitations of conventional collimator systems. Methods are discussed which depend on deviation of the sight line, and on windshield reflection of the uncollimated image of a simple pointer. Limited flight tests show some promise for the uncollimated method.