A system for providing a Head-Up Display (HUD) on board an aircraft to assist a pilot in guiding the aircraft. The display is positioned in the pilot's normal line of sight. In one mode it utilizes a radio beam landing system such as an ILS (Instrument Landing System) to generate symbols that correspond to visual ground cues which, together with an aircraft symbol display, provide the pilot with cues for aligning the aircraft on the appropriate path for approach and landing. The system moves the aircraft symbol in accordance with motion changes of the aircraft. During a landing approach the pilot "flies" the aircraft symbol relative to the simulated and/or real ground cues. By making the HUD correspond with ground cues, the abrupt transition from instrumented to visual flight is eliminated. At altitudes below which available ILS is not acceptable, the system provides a smooth transition to a mode independent of ILS and then to a flare mode. The system also includes a mode that is totally independent of any ground installation. The system also provides an altitude hold mode with a smooth transition to the approach mode.
展开▼
