METHOD AND AVIONIC COMPUTER FOR DETERMINING AN ANCHOR POINT OF A TERMINAL SEGMENT FROM A BROKEN ACCESS POINT FOR A NON-PRECISION APPROACH

Description

technical field

[0001] The present invention relates to a method and an avionics computer for determining an anchor point of a terminal segment of a virtual trajectory for a non-precision FLS type approach mode of an aircraft, for the purpose of landing the aircraft on a runway of an aerodrome, as well as a method and a set of systems for implementing such a non-precision approach mode, comprising respectively such a method and such a device. State of the art

[0002] In the context of the present invention, "non-precision approach" means an approach that is not an instrument precision approach, such as, for example, an ILS ("Instrument Landing System") approach which uses, in particular, ground stations located at the edge of the runway and a specialized radio receiver mounted on board the aircraft.

[0003] A non-precision approach, such as that considered in the present invention, exists when the aforementioned equipment is not available or operational, at least partially, so that a conventional precision approach cannot be implemented. The present invention applies more particularly to a non-precision approach of the FLS type (for "FMS Landing System," where FMS stands for "Flight Management System," i.e., a landing system using a flight management system).

[0004] To implement this non-precision approach, known as FLS (Flight Leveling System), it is necessary to determine a virtual trajectory corresponding to the theoretical path the aircraft should follow during the approach. Aircraft guidance then consists of attempting to eliminate any discrepancies between the aircraft's actual position and the position it would have if it were on this virtual trajectory. Typically, the virtual trajectory includes a terminal segment, namely the last segment before reaching the runway. This terminal segment is defined relative to a downstream extreme point called the anchor point.

[0005] This anchor point is usually determined and positioned at the runway threshold, which is generally coded in a navigation database.

[0006] However, in certain situations, depending in particular on the orientation of the virtual trajectory relative to the runway axis, for example when the virtual trajectory crosses the runway axis downstream of the runway threshold, or when a missed approach point is located beyond the runway threshold, it is not possible to determine the anchor point and it is therefore not possible to implement a non-precision approach mode of the FLS type.

[0007] Furthermore, the runway threshold may sometimes be temporarily shifted, particularly when work is being carried out on the runway. In such cases, the position of the new runway threshold may not be updated in the navigation database, resulting in an incorrect runway threshold being displayed.

[0008] This usual system for implementing a non-precision approach mode of the FLS type can therefore still be improved, particularly in terms of availability and robustness.

[0009] Furthermore, we know: by document CN 112 880 679 A, ​​a method for generating a virtual FLS beam, based in particular on information relating to the positions of points FAF, MAP, LTP and FEP, the orientation of the runway, the height TCH and the angle FPA; and by document US2004 / 183698 A1, a method and a device for determining a final approach axis of an aircraft for a non-precision approach, with a view to landing the aircraft on a runway. Description of the invention

[0010] An objective of the present invention is to improve the implementation of a non-precision approach mode of the FLS type for an aircraft. To this end, it relates to a method for determining an anchor point of a terminal segment of a virtual trajectory for a non-precision approach mode of the FLS type (or FLS mode) of an aircraft, for the purpose of landing the aircraft on a runway of an aerodrome, said terminal segment starting at a final approach point and ending at said anchor point, said method being implemented in an avionics computer, in particular a flight management system (FMS for "Flight Management System"), comprising at least one processing unit and a navigation database.

[0011] According to the invention, said method comprises at least the following steps: a comparison step, implemented by the avionics computer processing unit, consisting of comparing a first altitude to a so-called threshold altitude, the first altitude corresponding to the altitude of a missed approach point relative to the runway and contained in the avionics computer's navigation database, the threshold altitude being equal to the sum of a second altitude corresponding to the runway altitude and a runway threshold height;and a calculation step, also implemented by the avionics computer's processing unit, consisting of determining, based on this comparison, a terminal point whose altitude is equal to said threshold altitude, and whose straight segment formed by this terminal point with the position of the missed approach point has a slope equal to that of the straight segment defined by the missed approach point and the final approach point, the terminal point (thus determined) being capable of being used as an anchor point, a method whereby, if the comparison step concludes that the first altitude is lower than said threshold altitude, said terminal point is used as an anchor point, in the absence of a prescribed final point in the navigation database.

[0012] Thus, to determine the anchor point, this method does not use the runway threshold, as is currently the case, but the Missed Approach Point (MAP), or MAP point, which corresponds to the latest point at which the pilot must initiate a go-around when the corresponding approach is missed. This MAP point, which is integrated into the aerodrome's navigation database, is a parameter that is regularly updated. Furthermore, the anchor point is determined relative to a height above the runway, and no longer relative to a runway threshold position (which could be modified, for example, in the event of temporary maintenance). The method is therefore advantageous in terms of robustness (and safety).

[0013] Furthermore, as detailed below, the determination of the anchor point, as implemented by said method, is not limited by the orientation of the terminal segment of the virtual trajectory relative to the runway axis, which makes it possible to determine an anchor point in situations where this is not currently possible, and thus to increase the availability of the FLS mode.

[0014] Advantageously, if the comparison step concludes that the first altitude is greater than or equal to said threshold altitude (equal to the sum of the runway altitude and the runway threshold height), the calculation step uses said terminal point as the anchor point.

[0015] Furthermore, advantageously, if the comparison step concludes that the first altitude is lower than said threshold altitude, the calculation step uses the following as an anchor point: If a prescribed FEP (for "Final End Point" in English) endpoint is present in the navigation database, this prescribed FEP endpoint.

[0016] The implementation of the method is not limited by the orientation of the projection onto the ground of the terminal segment of the virtual trajectory relative to the runway axis, and can therefore be applied to the following situations: the projection on the ground of the terminal segment (of the virtual trajectory) is aligned with the runway axis or is parallel to this axis; the projection on the ground of the terminal segment (of the virtual trajectory) has with the runway axis a non-zero angle α less than or equal to 90°.

[0017] The present invention also relates to a method of implementing a non-precision approach mode of type FLS of an aircraft, for the purpose of landing the aircraft on a runway of an aerodrome, said method using a virtual trajectory comprising a terminal segment which is defined with respect to an anchor point, said method being implemented by a set of avionics systems.

[0018] According to the invention, said method comprises at least one method for determining an anchor point as described above and said method uses the anchor point determined by said method as the anchor point of the terminal segment of the virtual trajectory.

[0019] The present invention further relates to an avionics computer, in particular a flight management system (or computer), for determining an anchor point of a terminal segment of a virtual trajectory for an FLS mode, said terminal segment starting at a final approach point ending at said anchor point, said avionics computer comprising at least one processing unit and a navigation database.

[0020] According to the invention, the processing unit is configured: to compare a first altitude to a so-called threshold altitude, the first altitude corresponding to the altitude of a missed approach point relative to the runway and contained in the navigation database of the avionics computer, the threshold altitude being equal to the sum of a second altitude corresponding to the altitude of the runway and a runway threshold height;and to determine, based on this comparison, a terminal point whose altitude is equal to said threshold altitude, and whose straight line segment formed by this terminal point with the position of the missed approach point has a slope equal to that of the straight line segment defined by the missed approach point and the final approach point, said terminal point (thus determined) being capable of being used as an anchor point, said terminal point being used as an anchor point, in the absence of a prescribed final point in the navigation database, if the first altitude is lower than said threshold altitude.

[0021] The present invention also relates to a set of avionics systems for implementing an FLS mode, said set comprising at least one flight management system configured to use a virtual final trajectory of which a terminal segment is defined with respect to an anchor point.

[0022] According to the invention, said assembly (of systems) includes at least one avionics computer for determining an anchor point as described above, and said assembly (of systems) is configured to be able to use the anchor point determined by said avionics computer as the anchor point of the terminal segment of the virtual trajectory.

[0023] Furthermore, the present invention also relates to an aircraft, in particular a transport aircraft, which includes at least one avionics computer and / or at least one set of systems, such as those described above. Brief description of the figures

[0024] The accompanying figures will clearly illustrate how the invention can be implemented. In these figures, identical reference numerals designate similar features. figure 1is the block diagram of a particular embodiment of a set of systems for implementing a FLS mode, including an avionics computer for determining an anchor point of a terminal segment of a virtual trajectory. figure 2 is the synoptic diagram of a particular embodiment of a method for implementing a FLS mode, comprising a process for determining an anchor point of a terminal segment of a virtual trajectory. figure 3 is a schematic view in a vertical plane of a terminal segment of a virtual trajectory followed by an aircraft during an approach, highlighting the determination of an anchor point for a missed approach point located upstream of the runway. figure 4 is a schematic view in a horizontal plane of the situation of the figure 3 in the specific case of a non-zero angle between the terminal segment and the track axis. The figure 5is a schematic view in a vertical plane of a terminal segment of a virtual trajectory followed by an aircraft during an approach, allowing to highlight the determination of an anchor point for a missed approach point located downstream of the runway. Detailed description

[0025] Avionics computer 1, shown schematically on the figure 1 and allowing to illustrate the invention, is intended to determine an anchor point of a terminal segment of a virtual trajectory, as specified below.

[0026] In a preferred embodiment, this avionics computer 1 corresponds to a flight management system (or computer) of type FMS (“Flight Management System” in English) of an AC aircraft, for example a transport aircraft.

[0027] Furthermore, in a preferred application, this avionics computer 1 is part of a set 2 of systems, intended for the implementation of a non-precision approach mode of type FLS (hereinafter referred to as "FLS mode") of the aircraft AC.

[0028] In the examples of figures 3 to 5 , aircraft AC equipped with said assembly 2 is in the approach phase to a runway 3 (landing) of an aerodrome, with a view to landing on this runway 3.

[0029] Set 2 typically determines a virtual (final) trajectory TV and directs the aircraft AC to follow it for the implementation of an FLS mode, with a view to the landing of the aircraft AC on runway 3. More specifically, set 2 determines the lateral and vertical deviations of the current position of the aircraft AC relative to this virtual trajectory TV (or virtual approach axis), and the aircraft AC is then piloted in such a way as to cancel these deviations.

[0030] To achieve this, assembly 2 includes, in addition to the avionics computer 1, a group 4 of standard systems. Group 4 typically includes at least some of the following systems: an information processing system, for example a multimode landing aid receiver, of type MMR ("Multi Mode Receiver" in English); a flight guidance system, for example of type FG (for "Flight Guidance" in English); a flight warning system, for example of type FWS (for "Flight Warning System" in English); a terrain avoidance and warning system, for example of type TAWS (for "Terrain Avoidance and Warning System" in English).

[0031] The usual systems of group 4 are not described further in this description.

[0032] Assembly 2 (which is carried on the AC aircraft, as very schematically represented on the figures 3 to 5) is therefore intended to assist the pilot of the AC aircraft, in particular to implement the FLS mode along the virtual TV trajectory.

[0033] This virtual flight path TV includes a terminal segment 5 (or final approach segment). This terminal segment 5 corresponds to a straight line segment which, in the direction (illustrated by an arrow E) of the aircraft AC's flight during the approach, begins at a FAF (for "Final Approach Fix") point, that is, an upstream point representing a final approach point or landmark, and it has a slope β, generally on the order of 3°. In the following description, the terms "upstream" and "downstream" are defined relative to the direction of flight of the aircraft AC indicated by the arrow E on the diagram. figures 3 to 5 .

[0034] Terminal segment 5 ends at a downstream point representing an AP anchor point (or "anchor point" in English).

[0035] The avionics computer 1 is intended to determine the AP anchor point of the terminal segment 5 and to provide it to assembly 2 so that it can use it to implement the FLS mode.

[0036] To do this, the avionics computer 1 includes at least, as shown on the figure 1 : a navigation database 7 of type NDB (for "Navigation Data Base" in English); and a processing unit 8 (PROCESS for "Processing Unit" in English) configured to receive data, in particular from the navigation database 7, and to perform processing on this data.

[0037] More specifically, processing unit 8 is configured: to compare a first altitude A1 to a so-called threshold altitude A3, this first altitude corresponding to the altitude A1 of a missed approach point MAP (or MAP point) which is relative to runway 3 ( figures 3 and 5) and which is contained in the navigation database 7 of the avionics computer 8, the threshold altitude A3 being, for its part, equal to the sum of a second altitude A2 corresponding to the altitude of runway 3 and a runway threshold height TCH; and to determine, according to the result of this comparison, a terminal point 6 likely to be used as an AP anchor point.

[0038] As detailed below, the processing unit 8 is configured to calculate the terminal point 6 ( figures 3 to 5 ) so that it corresponds to a point whose altitude is equal to said threshold altitude A3, and whose straight segment 5B, 5C which this terminal point 6 forms with the position P1 of the interrupted approach point MAP has a slope β which is equal to the slope of the straight segment 5A defined by the interrupted approach point MAP and the point FAF.

[0039] The TCH runway threshold height (for "Threshold Crossing Height" in English) is either coded in the navigation database 7 or recorded in a memory of the avionics computer 1, generally being equal to 50 feet (about 15 meters) in this case.

[0040] Avionics computer 1 therefore does not use the runway threshold, as is currently the case, but the MAP point which is integrated into the navigation database 7 linked to the aerodrome and which is a parameter which is regularly updated, and determines the anchor point relative to a TCH height relative to runway 3 and no longer relative to a position of the runway threshold (which could be modified in the event of temporary works in particular), which is advantageous in terms of robustness (and safety).

[0041] The avionics computer 1, as described above, is intended to implement a process P (represented on the figure 2) for determining an anchor point AP of a terminal segment 5 of a virtual trajectory TV for an FLS mode of an AC aircraft, with a view to landing the AC aircraft on a runway 3 of an aerodrome, as illustrated in the figures 3 to 5 , the terminal segment 5 starting at the final approach point FAF and ending at the anchor point AP.

[0042] This process P is part of a method M ( figure 2 ) implementation by assembly 2 of an FLS mode, which uses the anchor point AP determined by said method P as the anchor point of the terminal segment 5 of the virtual trajectory TV during the implementation of the FLS mode.

[0043] The said process P comprises, as shown in the figure 2 including a comparison step E1 and a calculation step E2, detailed below.

[0044] The P procedure takes into account the position P1 (namely the latitude, longitude, and altitude A1) of the missed approach point MAP (for "Missed Approach Point"), or MAP point, relative to runway 3. The MAP point which is published corresponds to the limit point at which the pilot must go around at the latest when the corresponding approach is missed (which is notably the case when the pilot does not see runway 3 before arriving at this MAP point).

[0045] The P process also takes into account the altitude A2 corresponding to the altitude of runway 3, i.e. the altitude of the ground S at the level of runway 3, as well as the height TCH.

[0046] The E1 comparison step, implemented by processing unit 8, consists of: to calculate the threshold altitude A3 by adding the altitude A2 (of runway 3) and the runway threshold height TCH; and to compare the altitude A1 to this threshold altitude A3 (thus calculated).

[0047] The determination of the AP anchor point depends on the result of this comparison as specified below.

[0048] Furthermore, the calculation step E2, also implemented by the processing unit 8 after the comparison step E1, consists of determining, based on this comparison, the anchor point AP and in particular the terminal point 6.

[0049] More specifically, the calculation step E2 consists of determining the terminal point 6 as the point whose altitude is equal to the threshold altitude A3, and whose line segment 5B which this terminal point 6 forms with the position P1 of the point MAP has a slope β equal to that of the line segment 5A defined by the point MAP and the point FAF.

[0050] However, as indicated above, the determination (at calculation step E2) of the anchor point AP depends on the result of the comparison implemented at comparison step E1.

[0051] First, if the comparison step E1 concludes that the altitude A1 is greater than or equal to the threshold altitude A3, i.e. the sum of the altitude A2 and the height TCH of the runway threshold, the calculation step E2 determines said terminal point 6 and uses (and provides) it as the anchor point AP.

[0052] In such a situation, as depicted on the figure 3 The calculation unit 10 determines as terminal point 6 (and therefore as anchor point AP) the point of intersection between: on the one hand, an extension 5B upstream (as illustrated by an arrow F1) of part 5A (of terminal segment) determined between points FAF and MAP, from point MAP, along a slope of value equal to the angle (of slope) β of part 5A; and on the other hand, a horizontal plane 9 of threshold altitude A3.

[0053] In this situation, the terminal segment 5 which will be used for the implementation of the FLS mode and which is defined between the point FAF and the terminal point 6 (representing the anchor point AP) corresponds to the part 5A (of straight segment) to which the extension 5B (also representing a straight segment) has been added.

[0054] This situation applies to the following cases: to a first case (not shown) where the projection onto the ground of terminal segment 5 is aligned with the axis 3A of runway 3 or is parallel to this axis 3A of runway 3; and to a second case where the projection onto the ground of terminal segment 5 has a non-zero angle α (less than or equal to 90°) with the axis 3A of runway 3, as shown on the figure 4 . This second case therefore also concerns situations where the angle α is high and for example greater than 50°.

[0055] The determination of the AP anchor point, implemented by the P method, is therefore not limited by the orientation of the terminal segment 5 of the virtual TV trajectory relative to the 3A axis of track 3, which makes it possible to determine an AP anchor point in situations where this is not currently possible, and thus to increase the availability of the FLS mode.

[0056] Secondly, if the comparison step E1 concludes that the altitude A1 is less than the threshold altitude A3, i.e. the sum of the altitude A2 of runway 3 and the height TCH of the runway threshold, the calculation step E2 determines the anchor point AP, depending on the presence or not of a prescribed final point FEP (for "Final End Point" in English) in the navigation database 7.

[0057] More specifically, the calculation step E2 determines the following as the anchor point AP: in case of presence of a FEP point (for "Final End Point" in English) in the navigation database 7, this FEP point (not shown); and in case of absence of a FEP point in the navigation database 7, the terminal point 6 determined by the processing unit 8.

[0058] In this latter situation, as shown in the figure, the processing unit 8 determines as terminal point 6 (and therefore as anchor point AP) the point of intersection between: on the one hand, a setback 5C downstream (as illustrated by an arrow F2), with respect to part 5A (of terminal segment) determined between points FAF and MAP, from point MAP, according to a slope of value equal to the angle (of slope) β of part 5A; and on the other hand, a horizontal plane 9 of threshold altitude A3.

[0059] In this latter situation, the terminal segment 5 which will be used for the implementation of the FLS mode (in the absence of a FEP point) and which is defined between the FAF point and the terminal point 6 (representing the AP anchor point) corresponds to the part 5A (of a straight segment) from which the indentation 5C (also representing a straight segment) has been subtracted.

[0060] The avionics computer 1 and the P method (as well as assembly 2 and method M, which use the AP anchor point determined by the avionics computer 1 and the P method), as described above, offer numerous advantages. In particular, they offer the following advantages: in terms of robustness and safety, since they are not impacted by a temporary change in the runway threshold, particularly in the event of work; in terms of availability, since they allow the determination of an anchor point (and thus the implementation of FLS mode) for orientations of the terminal segment of the virtual trajectory relative to the runway axis which do not currently allow it, and in particular when the intersection between the projection on the ground of the terminal segment of the virtual trajectory and the runway axis is located beyond the runway and when the angle between this projection and the runway axis exceeds 50°; by providing information that may be used, if necessary, in a future automatic landing system for straight and non-offset approaches.

[0061] More specifically, compared to the usual operation, using the runway threshold (or a FEP point) as the anchor point, the AP anchor point (determined by the avionics computer 1) does not change in the following cases: The MAP point is located on the runway threshold; the MAP point is located beyond the runway threshold and a FEP point is coded in the navigation database 7, this FEP point corresponding in this case to the AP anchor point.

[0062] In contrast to normal operation, the AP anchor point (determined by the avionics computer 1) is modified when the MAP point is located upstream of the runway threshold, regardless of the orientation of the terminal segment relative to the runway centerline. This applies whether the terminal segment is aligned with or parallel to the runway centerline, or whether the terminal segment has a non-zero angle α of 90° or less with the runway centerline. This increases the robustness of the FLS mode (particularly in the case of a temporary displacement of the runway threshold).

[0063] In addition, an AP anchor point (enabling implementation of FLS mode) is determined by the avionics computer 1, in the following case for which such a determination was not possible with the usual operation: the MAP point is located beyond (downstream) the runway threshold and no FEP point is coded in the navigation database 7, which increases the availability of FLS mode (and robustness in case of temporary displacement of the runway threshold).

Claims

1. A method for determining an anchor point of a terminal segment of a virtual path for a non-precision FLS approach mode of an aircraft, with a view to landing the aircraft (AC) on a runway (3) of an aerodrome, said terminal segment (5) starting at a final approach fix (FAF) and ending at said anchor point (AP), said method (P) being implemented in an avionics computer (1), in particular a flight management system, comprising at least a processing unit (8) and a navigation database (7), said method (P) comprising at least the following steps: - a comparing step (E1), implemented by the processing unit (8) of the avionics computer (1), consisting in comparing a first altitude (A1) with what is referred to as a threshold altitude (A3), the first altitude corresponding to the altitude (A1) of a missed approach point (MAP) relative to the runway (3) contained in the navigation database (7) of the avionics computer (1), the threshold altitude (A3) being equal to the sum of a second altitude (A2) corresponding to the altitude of the runway (3) and of a threshold crossing height (TCH); and - a computing step (E2), also implemented by the processing unit (8) of the avionics computer (1), consisting in determining, depending on this comparison, a terminal point (6) that has an altitude equal to said threshold altitude (A3) and that forms, with the position (P1) of the missed approach point (MAP), a straight line segment (5B, 5C) that has a slope (β) equal to the slope of the straight line segment (5A) defined by the missed approach point (MAP) and the final approach fix (FAF), said terminal point (6) being capable of being used as anchor point (AP), the method being characterized in that, if the comparing step (E1) concludes that the first altitude (A1) is less than said threshold altitude (A3), said terminal point (6) is used as anchor point (AP), in case of absence of a prescribed final end point (FEP) from the navigation database (7).

2. The method as claimed in claim 1, characterized in that, if the comparing step (E1) concludes that the first altitude (A1) is greater than or equal to said threshold altitude (A3), the computing step (E2) uses said terminal point (6) as anchor point (AP).

3. The method as claimed in one of claims 1 and 2, characterized in that, if the comparing step (E1) concludes that the first altitude (A1) is less than said threshold altitude (A3), the computing step (E2) uses as anchor point (AP), in case of presence of a prescribed final end point (FEP) in the navigation database (7), this prescribed final end point (FEP).

4. The method as claimed in one of claims 1 to 3, characterized in that the projection on the ground (S) of the terminal segment (5) is parallel to or aligned with an axis (3A) of the runway (3).

5. The method as claimed in one of claims 1 to 3, characterized in that the projection on the ground (S) of the terminal segment (5) makes to an axis (3A) of the runway (3) a non-zero angle (α) less than or equal to 90°.

6. A procedure for implementing a non-precision FLS approach mode of an aircraft, with a view to landing the aircraft (AC) on a runway (3) of an aerodrome, said procedure (M) using a virtual path (TV) comprising a terminal segment (5) that is defined with respect to an anchor point (AP), said procedure being implemented by a set (2) of avionics systems, characterized in that it comprises at least a method (P) for determining an anchor point (AP) as claimed in any one of claims 1 to 5 and in that it uses the anchor point (AP) determined by said method (P) as anchor point of the terminal segment (5) of the virtual path (TV).

7. An avionics computer, in particular a flight management system, for determining an anchor point of a terminal segment of a virtual path for a non-precision FLS approach mode of an aircraft, with a view to landing the aircraft (AC) on a runway (3) of an aerodrome, said terminal segment (5) starting at a final approach fix (FAF) and ending at said anchor point (AP), said avionics computer (1) comprising at least a processing unit (8) and a navigation database (7), the processing unit (8) being configured: - to compare a first altitude (A1) with what is referred to as a threshold altitude (A3), the first altitude corresponding to the altitude (A1) of a missed approach point (MAP) relative to the runway (3) contained in the navigation database (7) of the avionics computer (1), the threshold altitude (A3) being equal to the sum of said second altitude (A2) corresponding to the altitude of the runway (3) and of a threshold crossing height (TCH); and - to determine, depending on this comparison, a terminal point (6) that has an altitude equal to said threshold altitude (A3) and that forms, with the position (P1) of the missed approach point (MAP), a straight line segment (5B, 5C) that has a slope (β) equal to the slope of the straight line segment (5A) defined by the missed approach point (MAP) and the final approach fix (FAF), said terminal point (6) being capable of being used as anchor point (AP), the processing unit being characterized in that said terminal point (6) is used as anchor point (AP), in case of absence of a prescribed final end point (FEP) from the navigation database (7), if the comparing step (E1) concludes that the first altitude (A1) is less than said threshold altitude (A3).

8. Set of avionics systems for implementing a non-precision FLS approach mode of an aircraft, with a view to landing the aircraft (AC) on a runway (3) of an aerodrome, said set (2) comprising at least a flight management system configured to use a virtual path (TV) comprising a terminal segment (5) that is defined with respect to an anchor point (AP), characterized in that it comprises at least an avionics computer (1) for determining an anchor point (AP) as claimed in claim 7 and in that it is configured to use the anchor point (AP) determined by said avionics computer (1) as anchor point of the terminal segment (5) of the virtual path (TV).

9. Aircraft, characterized in that it comprises at least a set (2) of systems as claimed in claim 8.