A course deviation indicator with a unique display utilizes at least one deviation bar, to indicate when a craft or vessel in which the course deviation indicator is utilized has deviated from a pre-established course. In one embodiment, the course deviation indicator has a lateral deviation bar, for indicating lateral deviation from a pre-established course, and a vertical deviation bar, for indicating vertical deviation from a pre-established course. A first, vertical, flag is associated with the vertical deviation bar, while a second, lateral flag is associated with the lateral deviation bar. When a determination is made that a particular deviation bar is providing inaccurate information, the appropriate flag is displayed, thereby indicating that the associated deviation bar is indeed providing inaccurate information. In one embodiment, the flags are displayed mechanically. In a second embodiment, the display is an LCD display, and flags are displayed by drawing the flags on the LCD display. Particularly, each flag is presented in the form of a bi-directional arrow. The vertical flag is oriented vertically on the display at a location proximate the outer end of the vertical deviation bar when the vertical deviation bar is in a centered position, and the lateral flag is presented laterally with respect to the display, and located proximate an outer end of the lateral deviation bar when the lateral deviation bar is in the centered position. The utilization of arrows as the flags, with no other identifying information, makes it particularly easy for a pilot or navigator of the craft or vessel in which the present invention is utilized to ascertain the nature of a deviation from a pre-established course.
An improved system and method are disclosed for indicating the validity of airport runway visual approach slope indicators on an aircraft display. An aircraft display system is provided, which includes a database for storing data about the specific visual approach slope lighting indicator system being used by each airport of a plurality of airports and any special distance and/or usage limitations associated with each such visual approach slope indicator system, a processing unit, a position determination unit, and a visual display. As an aircraft approaches an airport, the processing unit receives the aircraft's current position from the position determination unit, and compares the aircraft's current position data with the distance and/or usage limitation data stored in the database for the approach slope indicator system being used by that airport. If the processing unit's comparison of the aircraft's current position data and the airport's distance and/or usage data indicates that the visual approach slope lighting indicator system is within a valid range, then the processing unit provides a display format of a simulated airport environment for the airport of interest to the visual display, which includes a symbolic presentation of the airport's visual approach slope lighting indicators associated with the aircraft's current position, along with appropriate colors for the lighting elements being displayed. However, if the processing unit's comparison of the aircraft's current position data and the airport's distance and/or usage data indicates that the visual approach slope lighting indicator system is not within a valid range, then the processing unit provides a display format of a simulated airport environment for the airport of interest to the visual display, which includes a symbolic presentation of the airport's visual approach slope lighting indicators with the lighting elements capped, for example, with a red X symbol. Therefore, in this manner, the accuracy, availability and validity of the lighting system, and the safety of the aircraft's approach and landing are significantly improved.
