Methods, apparatus and computer program products for determining a corrected distance between an aircraft and a selected runway

Abstract

The present invention provides several apparatus, methods, and computer program products for determining a corrected distance between an aircraft and selected runway, such that the corrected distance may be used for ground proximity warning calculations. Specifically, the present invention includes a processor that receives data related to the coordinates of the aircraft and a selected runway. Based on these coordinate values, the processor determines a coordinate distance between the aircraft and selected runway. The processor also compares the altitude of the aircraft to a predetermined glideslope constructed about the runway. Specifically, the processor calculates a distance value that corresponds to the altitude of the aircraft above the runway along the predetermined glideslope. The processor compares the coordinate distance and the calculated distance values and selects either the coordinate distance or the calculated distance value as the corrected distance between the aircraft and the selected runway. For instance, in one embodiment, the processor compares the coordinate and calculated distance values and selects the larger of the values as the corrected distance between the aircraft and the selected runway. The present invention also provides a processor for determining a look ahead distance value for ground proximity warning calculations. The processor of this embodiment, initially determines differing look ahead distance values based on the corrected distance to the runway, ground speed of the aircraft, and the actual roll angle of the aircraft. The processor compares the three look ahead distance values and selects the smallest of the look ahead distance values for use in the ground proximity warning system.

Dependencies are inferred from the claim text.