Method for determining an emergency landing strip, device and corresponding program

Abstract

Method for determining an emergency landing strip, device and corresponding program. The invention relates to a method for determining a landing strip to be used for an emergency landing. Such a method is implemented in flight by an electronic device (2) carried within an aircraft.This method includes at least one iteration of the following steps: obtaining (01), from an onboard equipment (OBE) of said aircraft, representative data of current wind characteristics (DrW) at a current altitude of said aircraft; determining (02) the landing runway to be used for the emergency landing, based on the representative data of current wind characteristics at the current altitude (DrW), a set of preselected landing runways (Epr), and based on a correlation data structure (TR) between the representative data of wind characteristics at the current altitude (DrW) and representative data of runways in use on the ground (DrG). Figure for the abstract: 2.

Description

Title of the invention: Method for determining an emergency landing runway, device and corresponding program Domain

[0001] The invention relates to the field of air navigation. The invention relates more particularly to the field of aircraft flight planning. The invention aims more particularly to determine, for a given flight plan, one or more contingency tracks that can be used. Previous Art

[0002] When implementing air navigation operations, the definition of a flight plan is a step prior to the air transport operation itself. The definition of a flight plan makes it possible, in particular, to plan the dialogue with the air traffic controllers on the ground. It contains information on the identity and characteristics of the aircraft, the number of people on board, the description of the trajectory, etc. In the context of commercial transport operations, a repetitive flight plan (RPL) may be used by airlines to describe scheduled flights. For the implementation of the commercial air transport operation, the flight crew, generally composed of a pilot and a co-pilot, is supposed to follow the flight plan that has been established.If, during the transport operation, one of the flight crew members (the pilot or co-pilot) finds himself in a situation of physical incapacity to continue the operations incumbent upon him (due to illness, for example), the remaining flight crew is supposed to be able to continue flight operations and / or to identify, in conjunction with ground control, a diversion airport and a landing runway to be able to land the aircraft urgently if the need arises.

[0003] In the case of single-pilot commercial flight operations (also known as "SPO" for "Single Pilot Operation"), pilot incapacity poses significantly more difficulties. Indeed, not having a backup, the pilot who is unable to continue piloting operations leaves the computerized aircraft management systems with the technical responsibility, on the one hand, of taking charge of continuing the flight operation and, on the other hand, of landing the aircraft in conditions of maximum safety and within a relatively short time.

[0004] To date, there are computerized flight management systems, such as for example the FMS (from the English for "Flight Management System"), which are able to autonomously manage phases of commercial transport operations (either alone or in coordination with other computerized subsystems of the aircraft) such as taxiing, takeoff, cruise and landing. More specifically, the aircraft's computerized system is able to carry out the technical operations relating to these phases: once placed on the takeoff runway, the computerized system is able to carry out the takeoff; once placed on the appropriate landing procedure (allowing landing on the runway assigned to the pilot by ground control), for example when a certain number of ground equipment (ILS from the English "Instrument Landing System" of category III) and conditions are met (specific to the aircraft, the crew, and the state of the systems and external conditions, in particular the wind) the computerized system is able to carry it out.

[0005] The situation is different, however, when the only pilot on board is unable to make the connection with ground control. The computer system must then not only determine on its own which airport it must make an emergency landing at, but it must also determine the runway on which the landing must be made.

[0006] It is recalled that an airplane flies, takes off and lands as long as its speed of movement relative to the air is greater than its stall speed (minimum air speed which depends to the first order on the configuration of the airplane - that is to say the state of extension of the landing gear, slats and flaps). On landing, the speed of the airplane relative to the ground is reduced if, in a terrestrial reference frame, the air mass in which the airplane is flying moves in the opposite direction to the movement of the airplane (in other words if the airplane is landing with a headwind component). The ideal is therefore to take off or land with a headwind (most airplanes nevertheless have a declared flight envelope which allows them to land and take off in tailwind conditions, but for fairly limited wind values). The single or main runway of an airport is therefore generally oriented in the direction of the prevailing wind.When the wind speed is not aligned with the runway direction, the aircraft must take off or land with a crosswind component whose maximum permissible value is determined by the manufacturer (as for headwind and tailwind). To allow operations regardless of the wind direction, some airports have one or two additional runways forming an angle of approximately 90° or 60° between them. In the context of an emergency landing in automatic mode, it is necessary for the aircraft to be able to land into the wind, in order to limit the risks of runway excursion, i.e. the risks of exceeding the maximum landing distance of the runway.

[0007] However, there is currently no way of easily and automatically determining the runway on which the automatic emergency landing can be carried out safely. Summary

[0008] The invention aims to overcome this drawback and in particular, to enable automatic determination of the runway on which the automatic emergency landing can be carried out, in complete safety. More particularly, the invention relates to a method for determining a landing runway to be used to carry out an emergency landing, a method implemented in flight, by an electronic device on board an aircraft. Such a method comprises at least one iteration of the following steps: - obtaining, from on-board equipment of the aircraft, data representative of current wind characteristics, at a current altitude of the aircraft; - determination of the landing runway to be used to carry out the emergency landing, based on data representative of current wind characteristics at the current altitude, of a set of preselected landing runways, and based on a correlation data structure between the data representative of wind characteristics at the current altitude and data representative of runways in use on the ground.

[0009] Thus, the method of the invention makes it possible, at any time during the flight, to provide information relating to a runway in service as a function of conditions encountered in full flight, facilitating the implementation of automatic routing of the aircraft to an emergency landing runway.

[0010] According to a particular characteristic, the determination step comprises the steps following: obtaining, based on data representative of characteristics wind currents at current altitude and cor data structure relationship, of a record of data representative of a runway in service on the ground; - selection, from among the set of preselected landing runways, based on the recording of data representative of a runway in service on the ground, of the landing runway to be used to carry out the emergency landing.

[0011] Thus, the method implemented is able to facilitate the identification of the landing runway in the absence of intervention by a human operator, that is to say without the intervention of the pilot or co-pilot of the aircraft.

[0012] According to a particular characteristic, the step of obtaining a recording of data representative of a track in service on the ground, comprises: - a step of identifying, within the correlation data structure, at least one data record representative of the characteristics of the wind on the ground, each record comprising a probability of comparison tability of a track in use and a location area; - a step of selecting, from among said at least one identified recording, a recording based on the probability of compatibility of the track in service of this recording.

[0013] According to a particular characteristic, said step of selecting the record is carried out by selecting, from among said at least one identified record, the record whose probability of compatibility is the highest.

[0014] According to a particular characteristic, the step of selecting the landing runway to be used to carry out the emergency landing further comprises a step of obtaining, from equipment located on the ground, data representative of a runway in service from among all the preselected landing runways.

[0015] According to a particular characteristic, the determination method further comprises a step of preselecting, from a list of runways that can be used to carry out an emergency landing, the set of preselected landing runways, based on a flight plan of the aircraft.

[0016] According to a particular characteristic, said preselection step is implemented as a function of a position of the aircraft, said position being provided by an on-board instrument of the aircraft.

[0017] According to a particular characteristic, the data representative of the current characteristics of the wind at the current altitude by said aircraft are obtained from the speed, attitude and incidence information delivered by at least one piece of on-board equipment of the aircraft.

[0018] According to a particular characteristic, the correlation data structure between the data representative of wind characteristics at the current altitude and data representative of runways in service on the ground, comprises data making it possible to link the characteristics of the wind at altitude with those of the wind on the ground.

[0019] According to another aspect, the invention also relates to an electronic device on board an aircraft for determining a landing runway to be used for carrying out an emergency landing. According to the invention, such a device comprises: - a module for obtaining, from on-board equipment of the aircraft, data representative of current characteristics of the wind, at a current altitude of the aircraft; - a module for determining the landing runway to be used to carry out the emergency landing, based on data representative of wind characteristics at the current altitude, of a set of preselected landing runways, and based on a correlation data structure between the data representative of wind characteristics at the altitude current and representative data of tracks in ground services;

[0020] these modules being implemented iteratively. Brief Description of the Figures

[0021] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which: - [Fig.l] illustrates an electronic device capable of identifying an emergency landing strip based on wind conditions at altitude; - [Fig.2] illustrates the process of determining a landing runway emergency according to the invention; - [Fig.3] represents the way in which a correlation is carried out between the atmospheric wind conditions and the landing runway to be selected. Description of an embodiment

[0022] In relation to [Fig.l], an on-board electronic device 2 within an aircraft is presented for determining a landing runway to be used to carry out an emergency landing.

[0023] In the example of [Fig.l], the on-board electronic device 2 comprises an electronic memory unit 60, at least one calculation processor 50 and an interface 10 for communication with remote devices, such as on-board equipment or a computerized aircraft management system, by a chosen communication protocol, for example a wired protocol and / or a radio communication protocol. The elements of the device 2 are adapted to communicate via a communication bus 15.

[0024] In the example of [Fig.l], the on-board electronic device 2 comprises a module 20 for obtaining, from on-board equipment of the aircraft, data representative of current wind characteristics; a determination module 30 for determining the landing runway to be used to carry out the emergency landing, as a function of the data representative of wind characteristics at the current altitude, of a set of preselected landing runways, and as a function of a correlation data structure between the data representative of wind characteristics at the current altitude and data representative of runways in service. In the example of [Fig.l] these modules are each produced in the form of software, or a software brick, executable by the calculation processor 50.The memory 60 of the on-board electronic device 2 is then able to store the corresponding software program(s) and the processor is then able to execute each of these software programs.

[0025] In a variant not shown, these modules are produced in whole or in part in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array), or of an integrated circuit, such as an ASIC (Application Specified Integrated Circuit), this or these components being able to be coupled to the calculation processor as described previously.

[0026] When the on-board electronic device 2 is produced at least in part in the form of one or more software programs, that is to say in the form of a computer program, also called a computer program product, it is furthermore capable of being recorded on a medium, not shown, readable by a computer. The computer-readable medium is for example a medium capable of storing electronic instructions and of being coupled to a bus of a computer system. By way of example, the readable medium is an optical disk, a magneto-optical disk, a ROM memory, a RAM memory, any type of non-volatile memory (for example FLASH or NVRAM) or a magnetic card. A computer program comprising software instructions is then stored on the readable medium.

[0027] The invention makes it possible to give the capacity, to a computerized flight system of an aircraft, to determine, in real time, the most appropriate runway for carrying out an emergency landing. The on-board electronic device 2 makes it possible, in the case of a flight operation with a flight crew composed of two people, to facilitate the emergency landing management operations. The on-board electronic device 2 makes it possible, in the case of a flight operation with a flight crew composed of a single pilot, to carry out an emergency landing automatically, for example when the pilot is unable to carry out the landing operation, but also to facilitate the emergency landing management operations (if the single pilot is not in an incapacitated situation).The on-board electronic device 2 contributes to enabling, in all cases, the automatic management of a joining phase of the procedures adapted to the runway in use with a view to the landing of an aircraft. The aircraft is for example an airplane, such as a commercial airliner. Alternatively, the aircraft is a business jet, a private plane classified in the general aviation category, a helicopter, a drone remotely piloted by a pilot, or even an autonomous aircraft without an operator.

[0028] In relation to [Fig. 2], a method for determining a landing runway to be used to carry out an emergency landing is presented. This method is implemented in flight, by the on-board electronic device 2 within an aircraft, which may be separate or integrated within an aircraft management system (for example within a main computer or other equipment, such as an FMS). This method comprises at least one iteration of the following steps: - obtaining 01, from an OBE on-board equipment of the aircraft, data representative of current characteristics of the DrW wind, at an altitude current, of the aircraft; - determination 02 of the landing runway to be used to carry out the emergency landing PaU, based on data representative of wind characteristics at the current altitude DrW, of a set of preselected landing runways Epr, and based on a correlation data structure TR between the data representative of wind characteristics at the current altitude DrW and data representative of runways in service on the ground.

[0029] The preselected landing runways are, for example, those whose airports are located close to the route of the aircraft's flight plan, as defined before takeoff. Furthermore, the preselected landing runways may be reduced in number depending on other factors, as the flight progresses, such as, for example, a deterioration in weather conditions or even a distance outside the range of the aircraft. More particularly, in an exemplary embodiment, the step 02 of determining the landing runway PaU to be used to carry out an emergency landing comprises the steps: - obtaining 021, as a function of the data representative of wind characteristics at the current altitude DrW and as a function of the correlation data structure TR, a record of data representative of a runway in service on the ground DrG; - selection 022, within the set of preselected landing runways Epr, based on data representative of a runway in service on the ground DrG, of the landing runway PaU to be used to carry out the emergency landing.

[0030] Thanks to this way of proceeding, it is possible, even under wind conditions that are little or poorly known at the start of the flight, to obtain an indication relating to a landing runway to be used in the event of an emergency. For example, the data representative of current wind characteristics DrW which are obtained during flight are the speed and / or the current direction of the wind. These data are then used as a parameter to determine equivalent data encountered on the ground DrG. This determination is carried out in particular by using one or more data structures available to the onboard electronic device 2, which in particular make it possible to link the characteristics of the wind at altitude with those of the wind on the ground. These data structures are prepared in advance, on the ground, in the context of processing mass data sets, for example.They are then recorded within the aircraft, on a suitable data medium, and can be used by the on-board electronic device 2.

[0031] Additionally, other data structures are also used to store the flight plan on the one hand and identify, on this flight plan, a more or less significant set of runways that can be used as emergency landing runways on this flight plan. Each of these runways includes in particular at least one location (for example in the form of GPS coordinates). These locations make it possible in particular to determine the distance of these runways from any point on the flight plan planned before takeoff.

[0032] More specifically, in relation to [Fig.3], the step 021 of obtaining data representative of a runway in service on the ground, comprises: - an identification step 0211, within the correlation data structure TR, of at least one record representing data representative of the characteristics of the ground wind EdCs, each record EdC comprising a probability of compatibility (and optionally a location zone ZL, for example in the form of GPS-type coordinates); this identification 0211 is carried out using the data representative of characteristics of the wind DrW at altitude provided as parameters, and optionally additional location data DC; It may be that this identification 0211 only delivers a single record, depending on the situations. - a selection step 0212, among the records representing data representative of the characteristics of the ground wind EdCs, of a DrG record according to the probability of compatibility associated with this record.

[0033] When the identification step only delivers a single record, the selection consists of selecting this record. The technique described thus exploits data (in particular data prepared on the ground), making it possible to establish a level of correlation between:

[0034] - the intensity and direction of the wind, on the ground, at an airport (this airport having been identified before the mission as a possible diversion airport if necessary, due to its proximity to the flight plan); and

[0035] - the current wind intensity and direction at the current altitude, over the portion of the primary flight plan for which this airport is identified as an alternate airport.

[0036] When it is determined, in an exemplary embodiment, before the flight, that a backup airport comprises a compatible runway for an emergency landing, then this airport is selected during the flight if a diversion is necessary on the portion of the flight plan relating to this backup airport, and it is then appropriate to determine, thanks to this correlation, the most probable “in service” runway for carrying out the emergency landing.

[0037] The determination of the compatible runway can be implemented in several different ways. For example, the determination of the compatible runway can be implemented in two stages, by searching within a data structure identifying the runways, firstly, for a runway close to the current position of the aircraft and secondly by implementing the determination method previously described (steps 01 to 03) to determine for this airport which runway is compatible. It is recalled that a runway in use corresponds to an orientation, so that for an airport composed, for example, of a length of asphalt runway of 1500m, there are two potentially active runways: for example runway 05 (oriented in the direction of 50° of Magnetic North) and runway 23 (oriented in the direction of 230° of Magnetic North). These two runways are opposite each other but relative to the same strip of asphalt.In this example, it is assumed that given the wind encountered at altitude when leaving the initial flight plan to head towards the pre-identified (pre-selected) emergency airport before the flight, the probability that it is runway 05 is 70% and the probability that it is runway 23 is therefore 30%. Runway 05 is therefore selected by device 2 as the emergency landing runway. In other words, in this first scenario, device 2 continuously searches for a runway close to the aircraft's position.Then the device 2 implements steps 01 to 03, for the preselected runway(s) based on this position to retain only the runway which presents the highest probability (in the case of equivalent probability the best oriented runway will be retained, i.e. the one which is most consistent with the direction of the aircraft when it changes course towards the alternate airport; the device 2 can also take into account the preferred runway which is declared in approach charts, when the device 2 has this information digitally.

[0038] A second exemplary embodiment for determining the compatible runway may consist of directly implementing, by the device 2, a selection of a runway whose probability of compatibility is the highest. The identification step 021 may then be carried out within a predetermined range of action relative to the current position of the aircraft: the range of action is the complementary location data DC in this case. In which case, the runway whose ground wind conditions have the highest probability of compatibility, within the predetermined range of action, is selected, even if a closer runway could potentially have been used, but with less likely favorable ground wind conditions.In other words, in this implementation, the device 2 identifies several wind zones that are probably compatible based on the current position of the aircraft and a radius of action around this current position. The identification step 021 therefore provides several wind conditions on the ground (and therefore several runways in service). each associated with a position, within a predetermined range of action.

[0039] Other determination methods are of course conceivable depending on the operational implementation conditions. Generally, the device 2 can for example preselect, from the list of runways that can be used to carry out an emergency landing, the set of preselected landing runways, depending on a flight plan of the aircraft, and for example depending on the position of the aircraft, this position being provided by an instrument on board the aircraft.

[0040] In addition to the data from the processing of ground and altitude wind data, it is also possible to use other data. In particular, the device 2 can recover, before and during the flight, data relating to the runways in use, for all or part of the airports located at a greater or lesser distance from certain points of the flight plan. Indeed, there are sources of data relating to the runways in use at an airport which make it possible to supplement the data relating to the probability of runways in use calculated in flight. For example, on approach to an airport, the runway in use is generally communicated by radio link by ATC to the pilot (from the English “Air Traffic Control”) when the aircraft joins the controlled airspace and is within VHF radio contact range of ATC.Furthermore, PATIS (from the English "Air Traffic Information Service") is an automatic information message intended for crews, broadcast in a loop on a VHF frequency separate from that of the ATC (unrelated), specific to each airport, which provides the latest information to be shared between operational personnel at this airport (atmospheric pressure, dew point, visibility, wind intensity and direction, last runway in use). This ATIS message may be updated if conditions change and in particular in the event of a change of runway. Provided that it exists for the diversion airport, this ATIS message can be received provided that it is within radio signal range (the range depends on the transmission power, distance, relief and reception quality (receiver sensitivity)).Finally, some airports are equipped with D-ATIS (from the English for "Digital ATIS" or for "Data-Link Automatic Terminal Information Service") which allows the same information to be broadcast to be retrieved with on-board connectivity (D-Link AOC, LTE, other). In addition, airports also broadcast, at more or less regular intervals, meteorological site observation reports (METAR) which can provide useful data for determining the runway in use (METARs communicate the intensity and direction of the wind. METARs are updated periodically, generally every 30 minutes or every 1 hour in France for example).

[0041] Thus, depending on the available data and the radio range of the aircraft relative to the airport, the selection step 03, by the device 2, of the landing runway PaU to be used to carry out an emergency landing, within the set of runways preselected landings EPr, based on data representative of a runway in service on the ground DrG, can also take into account data relating to runways in service: - from a D-ATIS message; - by voice recognition on the ATIS frequency (without impact on the pilot's workload) when the ATIS Radio message is accessible (i.e. it is within radio range); - by listening to the ATIS message directly by the pilot, when the ATIS Radio message is accessible (i.e. it is within radio range and a pilot is able to listen to it); - by retrieving meteorological observations broadcast by certain services subject to availability at the airports concerned (METAR message).

[0042] These additional data can be used, depending on their availability, for example to refine the selection of the emergency landing runway. For example, in the presence of several preselected landing runways, based on data representative of a runway in service on the ground DrG, the step 03 of selecting the landing runway PaU comprises for example the determination of the runway to be used based on data representative of a runway in service coming from one of the data sources identified previously. For example, in the presence of a single preselected landing runway, the confirmation of the use of this landing runway can be carried out based on data representative of the runway in service coming from one of these additional data sources.

[0043] The determination of the ground wind characteristics takes into account the determination of the wind characteristics at altitude, as explained previously. It is recalled that the current wind characteristics in flight (at altitude) are developed in particular from the speed triangle. This speed triangle is based on obtaining data from on-board equipment which delivers: - The TAS from English for “True Air Speed” (based on the CAS and the S AT / OAT allowing to know the density of the air, possibly corrected by a compressibility factor beyond certain speeds) from an ADU (Air Data Unit); - The GS, from the English for “Ground Speed” (from an on-board electronic device 2 GPS or an inertial unit; - The Course or “Heading” (from a heading unit or inertial unit) - The route or “Track” (in the same reference system as the Heading, True or Mag, from an on-board electronic device 2 GPS or from an inertial unit).

[0044] The speed triangle makes it possible to determine the wind speed and the wind angle and therefore to determine the direction of the horizontal wind at altitude. As for the vertical wind at altitude, the latter can also be used as an input parameter for the correlation data structure. In which case, for this additional data to be useful, it is interesting to construct the correlation data structure by also having measurements of the horizontal wind.

[0045] According to the invention, in order to be able to determine the wind conditions encountered on the ground, it is useful to construct, beforehand, one or more correlation data structures. The objective of these correlation data structures is to make it possible to link the wind conditions on the ground and the wind conditions at altitude. To do this, a set of data is prepared, in advance of the phase, from a set of past meteorological observations. More particularly, the preparation comprises a step of collecting, for a given geographical area (for example an airport) a set of given meteorological observations. These observations are ideally collected for a relatively long time period, for example several years.These observations include, in addition to the date and time, the direction and strength of the wind at ground level (at the airport) and the direction and strength of the wind at different altitudes (e.g. from 1,000 to 35,000 feet, ideally centered around the most frequently used cruising altitudes).

[0046] The observations are then grouped, for example, according to the direction (and optionally the strength) of the wind encountered at altitude. The observations can also be grouped according to time periods (such as meteorological seasons, or other suitable time divisions). Several grouping criteria can be applied simultaneously. After applying the grouping criteria, groups of meteorological observations are obtained. For each grouping of meteorological observations, metrics are constructed: these metrics are, for example, the mean and standard deviation of the direction of the wind encountered at altitude and the mean and standard deviation of the direction of the wind encountered on the ground.These statistics make it possible, for example for a given time period (such as a given week, a given month or a given meteorological season) to link flight conditions at altitude with wind conditions on the ground and to determine a statistic of implication of conditions on the ground according to the conditions at altitude as well as a statistic relating to the runway in use taking into account these meteorological statistics. Thus, to the extent that these statistics relate to a given airport, it is also determined, according to these observations, which runway in use is associated with these groups or these observations each time.

[0047] In another exemplary embodiment, the correlation data structures are constructed based on the runway in use as the starting point for grouping meteorological observations. In this case, observations are grouped according to the runway in use, for landing (possibly also grouping by time period, as previously). These groupings make it possible to construct statistics relating to the meteorological conditions encountered at altitude, for example relating to wind direction and wind strength at altitude (possibly also establishing statistics relating to wind direction and wind strength at ground level).

[0048] Consequently, from the history of the ground and altitude meteorological data, it is possible to construct, for each airport (for example each airport located near the plan of the different positions of a given flight plan), a correlation data structure which makes it possible to link average altitude meteorological conditions to average ground meteorological conditions as well as to a corresponding runway in use. It is also possible to directly link average altitude meteorological conditions to a corresponding runway in use at the airport.

[0049] Thus, in a first exemplary embodiment, this TR correlation data structure may be in the form of a table (for example a database table), comprising several records. Each record comprises, for example, an average value of direction and orientation of the wind on the ground at the emergency airport (which would, optionally, be a function of the torque (strength, direction) of the wind encountered at altitude), depending on the implementation conditions, an identification of a relative time range (week, month, meteorological season for example).Another type of recording could take the form of a probability of being a runway in use (for example for runway 05 and for runway 23, from the previous example) of the alternate airport which would be a function of the torque (strength, direction) of the wind encountered at different altitudes flown along the flight plan, over a relative time range (week, month, meteorological season for example).

[0050] In a second exemplary embodiment, this TR correlation data structure may be in the form of a table, comprising several records. Each record comprises, for example, an average value of direction (and optionally an average value of force) of wind encountered at altitude and a corresponding in-service runway identifier and a probability of correspondence.

Claims

Claims

1. Method for determining a landing runway to be used for carrying out an emergency landing, method implemented in flight, by an electronic device (2) on board an aircraft, the method being characterized in that it comprises at least one iteration of the following steps: - obtaining (01), from on-board equipment (OBE) of said aircraft, data representative of current wind characteristics (DrW), at a current altitude of said aircraft; - determination (02) of the landing runway to be used to carry out the emergency landing, based on data representative of current wind characteristics at the current altitude (DrW), of a set of preselected landing runways (Epr), and based on a correlation data structure (TR) between the data representative of wind characteristics at the current altitude (DrW) and data representative of runways in use on the ground (DrG).

2. Determination method according to claim 1, characterized in that the determination step (02) comprises the following steps: - obtaining (021), as a function of the data representative of current characteristics of the wind at the current altitude (DrW) and the correlation data structure (TR), a record of data representative of a runway in service on the ground (DrG); - selection (022), within the set of preselected landing runways (Epr), based on the recording of data representative of a runway in service on the ground (DrG), of the landing runway to be used to carry out the emergency landing.

3. Determination method according to claim 2, characterized in that the step of obtaining (021) a recording of data representative of a runway in service on the ground (DrG), comprises: - an identification step (0211), within the structure of correlation data (TR), of at least one recording (EdCs) of data representative of the characteristics of the ground wind, each recording comprising a probability of compatibility of a runway in service and a location area; - a selection step (0212), from said at least one identified recording (EdCs), of a recording (DrG) as a function of the probability of compatibility of the runway in service of this recording.

4. Determination method according to claim 3, characterized in that said step of selecting (0212) the record (DrG) is carried out by selecting, from among said at least one identified record (EdCs), the record whose probability of compatibility is the highest.

5. Determination method according to one of claims 2 to 4, characterized in that the step of selecting (022) the landing runway to be used to carry out the emergency landing further comprises a step of obtaining, from equipment located on the ground, data representative of a runway in service from among the set of preselected landing runways (Epr).

6. Determination method according to one of claims 1 to 5, characterized in that it further comprises a step of preselecting, from a list of runways that can be used to carry out an emergency landing, said set of preselected landing runways, as a function of a flight plan of said aircraft.

7. Determination method according to claim 6, characterized in that said preselection step is implemented as a function of a position of said aircraft, said position being provided by an on-board instrument of said aircraft.

8. Determination method according to one of claims 1 to 7, characterized in that the data representative of the current characteristics of the wind at current flatness by said aircraft are obtained from the speed, attitude and incidence information delivered by at least one on-board equipment (OBE) of said aircraft.

9. Determination method according to claim 1 to 8 characterized in that the correlation data structure (TR) between the data represent- representative data of wind characteristics at current altitude (DrW) and representative data of runways in use on the ground (DrG) includes data allowing the characteristics of the wind at altitude to be linked with those of the wind on the ground.

10. Electronic device on board an aircraft for determining a landing runway to be used to carry out an emergency landing, characterized in that it comprises: - a module (20) for obtaining, from on-board equipment (OBE) of said aircraft, data representative of current characteristics of the wind (DrW), at a current altitude of said aircraft; - a module (30) for determining the landing runway to be used to carry out the emergency landing, as a function of data representative of wind characteristics at the current altitude (DrW), of a set of preselected landing runways (Epr), and as a function of a correlation data structure (TR) between the data representative of wind characteristics at the current altitude (DrW) and data representative of runways in ground services (DrG); these modules being implemented iteratively.

11. A computer program comprising software instructions which, when executed by a programmable electronic device, implement a method of determining a landing runway to be used for carrying out an emergency landing according to claims 1 to 9.

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