Method and a device for calculating a safe path from the current position of an aircraft to an attachment point
A method and device for calculating a safe path from a current position (P 1 ) of an aircraft to an attachment point (P 2 ) over a terrain. The current position (P 1 ) of the aircraft is determined, and then the attachment point (P 2 ) is defined. At least one attachment path connects he current position (P 1 ) to the attachment point (P 2 ) in safe manner over the terrain. The attachment path may be subdivided into a plurality of tracks ( 31 - 39 ). Each track ( 31 - 39 ) is situated at a safe altitude that is higher than the highest point of the terrain being overflown. In addition, the attachment path may be a return path defined by passage points (S 1 -S 8 ) of the aircraft.
1. A method of calculating a safe flight path over terrain from the current position of an aircraft to an attachment point, the method comprising the following steps:
selecting a strategy for choosing the attachment point and for choosing the type of the safe path;
determining the current position of the aircraft;
defining the attachment point that is to be reached by the aircraft; and
defining at least one attachment path connecting the current position of the aircraft to the attachment point in safe manner over the terrain;
wherein the attachment point is defined by being overflown by the aircraft, and passage points overflown by the aircraft are stored during the flight of the aircraft, and then the attachment path is defined as being a path passing via the passage points in reverse order, the current position being the last-stored passage point.
2. A method according to claim 1 , wherein the passage points are stored in real time, the passage points being selected by a crew member of the aircraft.
3. A method according to claim 1 , wherein the passage points are stored at regular intervals.
4. A method according to claim 1 , wherein it is verified that the attachment path does not interfere with the terrain.
5. A method according to claim 1 , wherein the attachment path is defined as being a path including a substantially straight and horizontal track connecting a first vertical line passing through the current position of the aircraft to a second vertical line passing through the attachment point.
6. A method according to claim 1 , wherein a flight plan is prepared beforehand and an initial route is defined by the flight plan, the attachment point being defined as being situated on the initial route, and the attachment path is defined as being a path comprising a straight first segment in a direction connecting a first vertical line passing through the current position of the aircraft to a second vertical line passing through the attachment point, and a curvilinear second segment is defined joining the straight first segment to the initial route, the curvilinear second segment leaving the straight first segment while maintaining continuity between them and joining the initial route while maintaining continuity therewith.
7. A method according to claim 4 , wherein the attachment path is positioned at a safe altitude.
8. A method according to claim 4 , wherein the attachment path is subdivided into a plurality of horizontal tracks that are adjacent in pairs, it is verified that each track does not interfere with the terrain, and each track interfering with the terrain, if any, is corrected by being positioned at a safe altitude.
9. A method according to claim 4 , wherein the attachment path is defined as being a path having a plurality of horizontal tracks that are adjacent in pairs, each track being situated at a safe altitude.
10. A method according to claim 7 , wherein the safe altitude of a track is equal to a height relative to the ground corresponding to the maximum height of the terrain situated under the track plus a safety margin.
11. A method according to claim 1 , wherein the attachment point is displayed together with each attachment path on display means of the aircraft.
12. A method according to claim 1 , wherein only one attachment path is defined.
13. A method according to claim 1 , wherein at least two attachment paths are defined and a pilot of the aircraft selects one of the attachment paths for reaching the attachment point.
14. A method according to claim 1 , wherein the aircraft includes an autopilot, and the aircraft is guided along the attachment path to the attachment point in automatic manner by means of the autopilot.
15. A device for calculating a safe flight path over terrain from a current position of an aircraft to an attachment point, the device comprising:
a man-machine interface MMI;
at least one display means;
at least one locating means for locating the aircraft;
at least one “terrain” and/or obstacles database; and
at least one calculator;
wherein the device is designed to perform a method of calculating the safe flight path over terrain from the current position of an aircraft to an attachment point, the method comprising the following steps:
selecting a strategy for choosing the attachment point and for choosing the type of the safe path;
determining the current position of the aircraft
defining the attachment point that is to be reached by the aircraft and
defining at least one attachment path connecting the current position of the aircraft to the attachment point in safe manner over the terrain;
wherein the attachment point is defined by being overflown by the aircraft, and passage points overflown by the aircraft are stored during the flight of the aircraft, and then the attachment path is defined as being a path passing via the passage points in reverse order, the current position being the last-stored passage point.
16. A method of calculating a safe flight path over terrain from the current position of an aircraft to a predefined point, the method comprising:
selecting a strategy for choosing the predefined point and for choosing the type of the safe path;
determining the current position of the aircraft;
defining the predefined point to be reached by the aircraft; and
defining at least one connecting path connecting the current position of the aircraft to the predefined point in a safe manner over the terrain;
wherein the predefined point is defined by being overflown by the aircraft, and passage points overflown by the aircraft are stored during the flight of the aircraft, and then the connecting path is defined as being a path passing via the passage points in reverse order, with the current position being the last-stored passage point.
17. A method according to claim 16 , wherein the passage points are stored in real time, the passage points being selected by a crew member of the aircraft.
18. A method according to claim 16 , wherein the passage points are stored at regular intervals.
19. A method according to claim 16 , wherein it is verified that the connecting path does not interfere with the terrain, and wherein the connecting path is defined as being a path including a substantially straight and horizontal track connecting a first vertical line passing through the current position of the aircraft to a second vertical line passing through the predefined point.
20. A method according to claim 16 , wherein a flight plan is prepared beforehand and an initial route is defined by the flight plan, the attachment point being defined as being situated on the initial route, and the attachment path is defined as being a path comprising a straight first segment in a direction connecting a first vertical line passing through the current position of the aircraft to a second vertical line passing through the attachment point, and a curvilinear second segment is defined joining the straight first segment to the initial route, the curvilinear second segment leaving the straight first segment while maintaining continuity between them and joining the initial route while maintaining continuity therewith.