Method for Evaluating and Signaling Lateral Manoeuvring Margins on Both Sides of the Planned Flight Plan of an Aircraft

• US 20080039984A1
• Filed: 05/31/2005
• Published: 02/14/2008
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Marty, Nicolas, Bitar, Elias
• Granted Patent: US 7,493,197 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration

Abstract

The parts of the flight plan of an aircraft corresponding to lateral trajectories at low altitude can comprise passages with limited lateral freedom of deployment either because of risks of collision with the ground, or because of risks of penetration into a forbidden overfly zone. The method makes it possible to signal them for the attention of the crew, on the onboard navigation screen, so that said crew should redouble their attention. To do this it uses a detection procedure analogous to that of TAWS ground collision risk warning systems with protection envelopes related to the aircraft, of shapes suitable for the monitoring of the integrity of the spaces necessary for the aircraft to perform flat turns that are as tight as is permitted, while taking account of the local wind.

Claims

1. A method for evaluating and signaling the lateral margins of maneuver on either side of a trajectory scheduled in the flight plan of an aircraft furnished with a locating device and with a cartographic device formulating, on the basis of a topographic database onboard or accessible from onboard, an envelope of the terrain overflown comprising the steps of:

generation, on the basis of a position of the aircraft traveling along the trajectory scheduled in the flight plan, of two adjoining lateral protection envelopes, right and left extending one to the right and the other to the left of a navigation band centered on the trajectory scheduled in the flight plan and of width Wn taking account of the uncertainties of location of the aircraft, of the inaccuracy of the envelope of the terrain overflown delivered by the cartographic device and of a lateral tolerance accepted in the tracking of the trajectory scheduled in the flight plan, the right lateral protection envelope delimiting a sufficient volume to allow the aircraft to perform at least one half-revolution, flat, to the right, during a turn with imposed radius R, the left lateral protection envelope also delimiting a sufficient volume to allow the aircraft to perform at least one half-revolution, flat, to the left, during a turn with imposed radius, and

detection of the intrusions of the envelope of the terrain overflown into the right and left lateral protection envelopes, and of signaling of the passages of the trajectory scheduled in the flight plan with reduced margins of lateral maneuver on the right and/or on the left corresponding to intrusions of the envelope of the terrain overflown into one or the other of the right or left lateral protection envelopes.

2. The method as claimed in claim 1, wherein a limitation of lateral margin of maneuver at a point of the trajectory (11) scheduled in the flight plan is signaled on a navigation map by a doubling of the plot of the trajectory at the point concerned, on the side of each right or left lateral protection envelope having undergone an intrusion of the envelope of the terrain overflown.

3. The method as claimed in claim 1, wherein the right and left lateral protection envelopes are dimensioned so as to delimit a sufficient volume to allow the aircraft to perform a complete revolution, flat, to the right or to the left while taking account of the local wind W.

4. The method as claimed in claim 1, wherein the turning radius R imposed is a permitted minimum turning radius for the aircraft considered.

5. The method as claimed in claim 1, wherein the right and left lateral protection envelopes are of parallelepipedal shape, with a horizontal lower face placed below the aircraft at a vertical distance H_b corresponding to a safety height margin MTCD increased by a margin of maneuver of return to the horizontal H_d, two vertical lateral faces, one tangent to the course of the aircraft, the other shifted laterally from the aircraft by the necessary distance W_r, WI required by the aircraft to accomplish a half-revolution taking account of the local wind W and the imposed turning radius R, a vertical frontal face and a vertical rear face having the course of the aircraft as director axis, the frontal face being placed ahead of the aircraft at a distance L_f corresponding to that necessary for the aircraft to accomplish a quarter of a revolution taking account of the local wind Ws and the imposed turning radius R, and the rear face being spaced from the front face by the distance necessary for the aircraft to supplement the quarter of a revolution with a half-revolution taking account of the local wind W and the imposed turning radius R.

6. The method as claimed in claim 1, wherein the longitudinal dimensions of the right and left lateral protection envelopes (6, 7) are dependent on the imposed turning radius R and the positions, with respect to the aircraft, of the points of the ground traces of the turns with the imposed radius R corresponding, for the aircraft, to a vanishing of its speed component parallel to the course scheduled in its flight plan.

7. The method as claimed in claim 1, wherein the lateral dimensions of the right and left lateral protection envelopes are dependent on the imposed turning radius R and the positions, with respect to the aircraft, of the points of the ground traces of the turns with the imposed radius R corresponding, for the aircraft, to a vanishing of its speed component perpendicular to the course scheduled in its flight plan.

8. The method as claimed in claim 1, wherein the right and left lateral protection envelopes have one and the same longitudinal dimension.

9. The method as claimed in claim 8, wherein the right and left lateral protection envelopes have as longitudinal dimension the sum of a component L_f, directed towards the front of the aircraft, taken equal to the largest value out of:

the turning diameter 2R whose value is given by;

10. The method as claimed in claim 1, wherein the lateral dimensions of the two right and left lateral protection envelopes have as lateral dimensions, the one, the right one W_r, the largest value out of:

the turning diameter 2R whose value is given by;