Patent ID: 7584046
Filing Date: 2009-09-01
Classification: G05D

Abstract:
1. A method of assisting low-altitude navigation of an aircraft equipped with a flight management system suited to determining a flight-plan ground trajectory for the aircraft based on a sequence of straight and/or curved segments joining intermediate points on the ground P at an altitude alt(P), where the ground trajectory takes into consideration the aircraft's performance and limitations, comprising the following steps: for each point P on the ground trajectory, calculating a safe altitude, alt safe, to obtain a point P calculating a safe profile formed from safe segments joining the points P extracting summit points S from among the points P determining the aircraft's weight at these points S as a function of the distance along the safe profile between the aircraft and this point S and of the aircraft's consumption over this distance, where the consumption is an aspect of ‘the aircraft’s performance and limitations, for each point S, determining the maximum climb slope (MaxClimbFPA) that the aircraft can support to reach S and the maximum-descent slope (MaxDescFPA) which the aircraft can support for following the lowest ground trajectory after having passed through S as a function of the aircraft's performance and limitations and the weight, defining two performance segments which have a first end at S, slopes MaxClimbFPA and MaxDescFPA on either side of the point S and a second end at the point of intersection with the terrain or with another performance segment arising from another point S and calculating a performance profile formed from performance segments and which makes it possible to associate at each point P of the safe profile a performance altitude, alt perf (P).