EP1512628B1 - Method and system for maintenance of radionavigation equipment of an aircraft - Google Patents

Abstract

The method involves disassembling radio navigation equipment (2) if one list has an event related to dysfunctions occurring on board of an aircraft. Another list having an event related to external data of the aircraft is analyzed if the former event is related to the equipment. The equipment is disassembled only if the event related to the data does not prove that the dysfunctions are due to problems related to the external data. The lists are stored in respective storage mediums. The external data is received by the equipment. An independent claim is also included for an aircraft having a maintenance device of radio navigation equipment.

Description

The present invention relates to a method and a device for maintaining a radionavigation equipment of an aircraft, in particular of a transport aircraft.

It is known that aircraft radionavigation equipment, such as a Distance Measuring Equipment (DME), a VHF (Very High Frequency) omnidirectional type GPS ("Global Positioning System") or landing aid device type GLS ("GPS Landing System"), for example, receives data that is external to the aircraft and develops information, including information relating to the position of the aircraft, from said external data. It generally provides this information to other systems of the aircraft, including systems for guiding or displaying the position of the aircraft. When a malfunction occurs on board the aircraft, the origin of which is identified as originating from the said information supplied by the said radionavigation equipment to other systems of the aircraft, the maintenance procedures provide that the said radionavigation equipment must be deposited and sent to a repairer to be checked and repaired if necessary.

However, the information provided by the radionavigation equipment may be erroneous, not only because of a failure of said radionavigation equipment, but also because of a problem relating to said external data received by said radionavigation equipment. In the latter case, the usual maintenance procedures are unnecessarily long and costly, since the radionavigation equipment is deposited and sent for repair, while it is not failure, since said malfunction occurred on board the aircraft is due to said data outside the aircraft.

The present invention aims to overcome these disadvantages. It relates to a method of maintenance of a radionavigation equipment of an aircraft, making it possible to reduce the number of cases, for which said radionavigation equipment must be deposited for verification and possible repair when this equipment is suspected of being at the expense of cause of a malfunction on board the aircraft.

Document US 6,115,656 describes a device according to the preamble of claim 6.

• a) on enregistre dans une première liste, le cas échéant, des premiers évènements relatifs à des données extérieures à l'aéronef, reçues par ledit équipement de radionavigation ;
• b) on enregistre dans une seconde liste, le cas échéant, des seconds évènements relatifs à des dysfonctionnements intervenant à bord de l'aéronef ;
• c) on vérifie si ladite seconde liste comporte au moins un second événement relatif à un dysfonctionnement, et :
  • c1) si ladite seconde liste ne comporte aucun second évènement, on ne dépose pas ledit équipement de radionavigation ; et
  • c2) si ladite seconde liste comporte au moins un second évènement relatif à un dysfonctionnement, on analyse tous les seconds évènements de ladite seconde liste, et :
    • α) si aucun desdits seconds évènements n'est relatif audit équipement de radionavigation, on ne dépose pas ledit équipement de radionavigation ; et
    • β) si au moins l'un desdits seconds évènements est relatif audit équipement de radionavigation, on analyse tous les premiers évènements de ladite première liste, et :
      • β1) si lesdits premiers évènements permettent de prouver que les différents dysfonctionnements sont dus à des problèmes relatifs auxdites données extérieures à l'aéronef, on ne dépose pas ledit équipement de radionavigation ;
      • β2) sinon, on dépose ledit équipement de radionavigation.

For this purpose, said method is remarkable, according to the invention, in that:

• a) where appropriate, first events relating to data external to the aircraft received by said radionavigation equipment are recorded in a first list;
• b) recording in a second list, if necessary, second events relating to malfunctions occurring on board the aircraft;
• c) checking whether said second list includes at least one second event relating to a malfunction, and
  • c1) if said second list does not include any second event, said radionavigation equipment is not deposited; and
  • c2) if said second list includes at least one second event relating to a malfunction, analyzing all the second events of said second list, and:
    • α) if none of said second events is relative to said radionavigation equipment, said radionavigation equipment is not deposited; and
    • β) if at least one of said second events is relative to said radionavigation equipment, all the first events of said first list are analyzed, and:
      • β1) if said first events make it possible to prove that the various malfunctions are due to problems relating to said data external to the aircraft, said radionavigation equipment is not deposited;
      • β2) otherwise, said radionavigation equipment is deposited.

Thus, thanks to the invention, said radionavigation equipment is deposited to send it for repair, only if said first recorded events can not prove that said malfunction is due to a problem relating to data outside the aircraft received by said radionavigation equipment, which of course allows to significantly reduce the number of unnecessary deposits, and therefore reduce the cost and maintenance time.

Preferably, it implements said steps a) and b) during the flight of the aircraft, and said step c) at the end of said flight, after the return to the ground of the aircraft.

In addition, these first events are advantageously recorded on a recording medium of said radionavigation equipment, and said second events are recorded on a recording medium of a system of the aircraft, which receives information from said equipment. radionavigation.

In a particular embodiment, said radionavigation equipment is a landing aid device of the aircraft combined with a satellite positioning system, and said first recorded events represent the situations for which the external data received by said landing aid device does not provide an indication of correct position of the aircraft.

• le nombre de satellites, desquels l'équipement de radionavigation reçoit des données, est insuffisant pour calculer une position de l'aéronef ;
• le niveau des signaux radiofréquence reçues par ledit équipement de radionavigation est inférieur à une valeur prédéterminée ;
• il existe des anomalies dans des messages de navigation transmis par un satellite dudit système de positionnement ;
• un satellite dudit système de positionnement est exclu par une station sol dudit système de positionnement ;
• des corrections fournies par une station sol dudit système de positionnement, sont trop anciennes pour un satellite dudit système de positionnement ;
• une station sol dudit système de positionnement, n'est pas opérationnelle ;
• il existe un problème d'intégrité de données fournies par une station sol dudit système de positionnement ;
• il existe une perte d'un signal reçu d'une station sol dudit système de positionnement ;
• il existe une erreur de transmission d'un signal reçu d'une station sol dudit système de positionnement ; et
• il existe une perte d'un niveau de protection prédéterminé.

In this case, preferably, said first events represent at least the following situations:

• the number of satellites, from which the radionavigation equipment receives data, is insufficient to calculate a position of the aircraft;
• the level of the radiofrequency signals received by said radionavigation equipment is less than a predetermined value;
• there are anomalies in navigation messages transmitted by a satellite of said positioning system;
• a satellite of said positioning system is excluded by a ground station of said positioning system;
• corrections provided by a ground station of said positioning system are too old for a satellite of said positioning system;
• a ground station of said positioning system is not operational;
• there is a data integrity problem provided by a ground station of said positioning system;
• there is a loss of a signal received from a ground station of said positioning system;
• there is a transmission error of a signal received from a ground station of said positioning system; and
• there is a loss of a predetermined level of protection.

The present invention also relates to an aircraft maintenance device.

• un premier moyen d'enregistrement pour enregistrer sur un premier support d'enregistrement des premiers évènements relatifs à des données extérieures à l'aéronef, reçues par ledit équipement de radionavigation;
• un second moyen d'enregistrement pour enregistrer sur un second support d'enregistrement des seconds évènements relatifs à des dysfonctionnements intervenant à bord de l'aéronef; et
• des moyens pour permettre l'analyse desdits premiers et seconds évènements enregistrés sur lesdits premiers et seconds supports d'enregistrement, afin de déterminer si ledit équipement de radionavigation doit être déposé ou non.

According to the invention, said device is remarkable in that it comprises:

• first recording means for recording on a first recording medium first events relating to data external to the aircraft, received by said radionavigation equipment;
• second recording means for recording on a second recording medium second events relating to malfunctions occurring on board the aircraft; and
• means for enabling analysis of said first and second events recorded on said first and second recording media to determine whether or not said radionavigation equipment is to be deposited.

• ledit premier moyen d'enregistrement est un moyen d'enregistrement dudit équipement de radionavigation ; et/ou
• ledit second moyen d'enregistrement est un moyen d'enregistrement d'un système de l'aéronef, qui reçoit des informations dudit équipement de radionavigation.

In a particular embodiment:

• said first recording means is a recording means of said radionavigation equipment; and or
• said second recording means is a recording means of a system of the aircraft, which receives information from said radionavigation equipment.

The figures of the appended drawing will make it clear how the invention can be realized. In these figures, identical references designate similar elements.

Figure 1 schematically illustrates a radionavigation equipment of an aircraft, which is applied a maintenance device according to the invention.

Figure 2 is a block diagram of a maintenance device according to the invention.

The device 1 according to the invention is intended for the maintenance of a radionavigation equipment 2 of an aircraft A, in particular a civil transport aircraft.

Said radionavigation equipment 2 may, in particular, be a Distance Measuring Equipment (DME), a VHF omnidirectional beacon ("Very High Frequency"), a GPS positioning system ("Global Positioning"). System ") or a landing aid of the GLS (" GPS Landing System ") type.

As can be seen in FIG. 1, said radio navigation equipment 2, of the usual type, which is arranged on board the aircraft A, is capable of receiving data from outside the aircraft A, in particular in the form of electromagnetic waves OE, using for example an antenna 3. It develops from these external data information, for example information or position indications, which it transmits, via links 4 , to user systems 5 of the aircraft A, including guidance systems or display systems.

In a preferred embodiment, said radionavigation equipment 2 is a landing aid device for the GLS aircraft A, which is combined with a positioning system 6.

This positioning system 6 comprises a set of satellites S1, S2 and / or ground stations P1, P2 which are provided on earth T. These satellites S1, S2 and these ground stations P1, P2 can communicate with each other, and with said equipment of radionavigation 2, using electromagnetic waves OE.

The maintenance device 1 is associated with said radionavigation equipment 2, as represented generally by a link 1A in phantom in FIG. 1, and as specified below, and is intended to make it possible to reduce the number of cases. , for which said radionavigation equipment 2 must be deposited for verification and possible repair when this equipment 2 is suspected of causing a malfunction on board the aircraft A.

• un moyen d'enregistrement usuel 7 pour enregistrer sur un support d'enregistrement 8, comme illustré par une liaison 9 en traits mixtes, dans une première liste, des premiers évènements relatifs à des données extérieures à l'aéronef A, reçues par ledit équipement de radionavigation 2 ;
• un moyen d'enregistrement usuel 10 pour enregistrer sur un support d'enregistrement 11, comme illustré par une liaison 12 en traits mixtes, dans une seconde liste, des seconds évènements relatifs à des dysfonctionnements intervenant à bord de l'aéronef A ; et
• une unité centrale 13 qui est reliée par des liaisons 14 et 15 respectivement auxdits supports d'enregistrement 8 et 11, pour permettre l'analyse desdits premiers et seconds évènements enregistrés sur lesdits supports d'enregistrement 8 et 11, afin de déterminer si ledit équipement de radionavigation 2 doit être déposé ou non.

To do this, said device 1 comprises, as represented in FIG. 2:

• a usual recording means 7 for recording on a recording medium 8, as illustrated by a link 9 in phantom, in a first list, first events relating to data outside the aircraft A, received by said equipment radionavigation 2;
• conventional recording means 10 for recording on a recording medium 11, as illustrated by a dashed line linkage, in a second list, second events relating to malfunctions occurring on board the aircraft A; and
• a central unit 13 which is connected by links 14 and 15 respectively to said recording media 8 and 11, to allow the analysis of said first and second events recorded on said recording media 8 and 11, to determine whether said equipment radionavigation 2 must be filed or not.

• si ladite seconde liste ne comporte aucun second évènement, on ne dépose pas ledit équipement de radionavigation 2 ; et
• si elle comporte au moins un second évènement relatif à un dysfonctionnement, on analyse tous les seconds évènements de ladite seconde liste, et :
  • α) si aucun desdits seconds évènements n'est relatif audit équipement de radionavigation 2, on ne dépose pas cet équipement de radionavigation 2 ; et
  • β) si au moins l'un desdits seconds évènements est relatif audit équipement de radionavigation 2, on analyse tous les premiers évènements de ladite première liste, et :
    • β1) si lesdits premiers évènements permettent de prouver que le ou les dysfonctionnements qui sont intervenus à bord de l'aéronef A, sont dus à des problèmes relatifs auxdites données extérieures à l'aéronef A, on ne dépose pas ledit équipement de radionavigation 2 ;
    • β2) sinon (si une telle preuve n'est pas possible), on dépose ledit équipement de radionavigation 2.

To do this, according to the invention, it is checked whether said second list comprises at least one second event, and:

• if said second list does not include any second event, said radionavigation equipment 2 is not deposited; and
• if it comprises at least one second event relating to a malfunction, analyzing all the second events of said second list, and:
  • α) if none of said second events is relative to said radionavigation equipment 2, this radionavigation equipment 2 is not deposited; and
  • β) if at least one of said second events is relative to said radionavigation equipment 2, all the first events of said first list are analyzed, and:
    • β1) if said first events make it possible to prove that the malfunction (s) that occurred on board the aircraft A, are due to problems relating to said data outside the aircraft A, it does not deposit said radionavigation equipment 2;
    • β2) otherwise (if such proof is not possible), said radionavigation equipment 2 is deposited.

Said central unit 13 comprises a means 16 and a display screen 17 which is connected by a link 18 to said means 16.

In a first embodiment, said means 16 is an information acquisition unit, which receives said first and second lists and displays them on the display screen 17. In this case, the previous analysis or verification is implemented by a maintenance operator, on reading said two lists which are presented to him on the display screen 17.

In a second embodiment, said means 16 is an information processing unit, which automatically implements the preceding analysis or verification, from said two lists received, and which presents the result of this analysis (removal or not). radio navigation equipment 2) to a maintenance operator by displaying it on the display screen 17.

Preferably, the aforementioned recording of the first and second events is performed during the flight of the aircraft A, and the analysis or verification of said recordings is performed later, after the return of the aircraft A.

Thanks to the invention, said maintenance device 1 has the advantage of avoiding depositing (and sending for repair) a radio navigation equipment 2, when this equipment 2 could not provide valid information to other systems 5 of the aircraft A, while the origin of the fact that he could not provide this information was not attributable to him, but was attributable to causes outside the aircraft A. This device maintenance 1 is therefore very advantageous in terms of duration and cost of maintenance.

In the aforementioned preferred embodiment relating to a GLS landing aid device, the radio navigation equipment 2 implements a complex function, since it uses external data from a space segment (signals RF radiofrequency transmitted by GPS satellites, for example satellites S1 and S2) and a ground segment (VHF data link transmitted by differential GPS ground stations, for example ground stations P1 and P2).

The RF signals and the VHF data are grouped in FIG. 1 under the reference OE generally denoting electromagnetic waves.

In this case, said first recorded events represent the situations for which the external data received by said landing aid device 2 do not make it possible to provide an indication of the correct position of the aircraft A.

• nombre de satellites "GPS" S1 et S2 (desquels l'équipement de radionavigation 2 reçoit des données) insuffisant pour calculer une position de l'aéronef A :
  • ■ niveau des signaux radiofréquence (reçus d'un satellite S1, S2) inférieur à une valeur en deçà de laquelle l'équipement de radionavigation 2 ne peut pas exploiter lesdits signaux ;
  • ■ anomalies dans les messages de navigation transmis par un satellite S1, S2 ;
  • ■ satellite S1, S2 exclu par une station sol P1, P2 (lorsque la station sol P1, P2 détermine que les données reçues de ce satellite S1, S2 ne sont pas fiables) ;
  • ■ corrections fournies par une station sol P1, P2 trop anciennes pour un satellite S1, S2 ;
• informations relatives à une station sol P1, P2 :
  • ■ station sol P1, P2 non opérationnelle (station en maintenance, invalidation de l'approche) ;
  • ■ problème d'intégrité des données fournies par la station sol P1, P2 ;
• perte du signal reçu d'une station sol P1, P2 (niveau du signal reçu inférieur à une valeur prédéterminée ou anomalie radiofréquence) ;
• erreur de transmission du signal reçu d'une station sol (P1, P2) ; et
• perte des niveaux de protection : l'équipement GLS calcule une "sphère de confiance" autour de la position GLS calculée. Si le rayon de cette sphère de confiance dépasse un seuil (appelé "alarme limite"), les informations fournies par l'équipement GLS à des systèmes 5 de l'aéronef A sont invalidées. La valeur de ce seuil peut être envoyée à l'aéronef A par une station sol P1, P2. Elle peut également être une valeur prédéterminée.

These first events are, in particular, the following:

• number of "GPS" satellites S1 and S2 (from which the radionavigation equipment 2 receives data) insufficient to calculate a position of the aircraft A:
  • ■ level of radiofrequency signals (received from a satellite S1, S2) less than a value below which the radionavigation equipment 2 can not operate said signals;
  • ■ anomalies in the navigation messages transmitted by a satellite S1, S2;
  • ■ satellite S1, S2 excluded by a ground station P1, P2 (when the ground station P1, P2 determines that the data received from this satellite S1, S2 are unreliable);
  • ■ corrections provided by a ground station P1, P2 too old for a satellite S1, S2;
• information relating to a ground station P1, P2:
  • ■ ground station P1, P2 not operational (station in maintenance, invalidation of the approach);
  • ■ data integrity issue provided by ground station P1, P2;
• loss of the signal received from a ground station P1, P2 (received signal level less than a predetermined value or radiofrequency anomaly);
• transmission error of the signal received from a ground station (P1, P2); and
• loss of protection levels: the GLS device calculates a "confidence sphere" around the calculated GLS position. If the radius of this sphere of confidence exceeds a threshold (called "limit alarm"), the information provided by the GLS equipment to systems 5 of the aircraft A are invalidated. The value of this threshold can be sent to the aircraft A by a ground station P1, P2. It can also be a predetermined value.

Claims (10)

1. A maintenance process for a radionavigation installation (2) of an aircraft (A), according to which in a step b) second events relating to malfunctions occurring on board the aircraft (A) are recorded in a second list, as appropriate,
   characterized in that, moreover:

   a) first events relating to data external to the aircraft (A), received by said radionavigation installation (2), are recorded in a first list, as appropriate;

   c) a check is carried out to verify whether said second list comprises at least one second event relating to a malfunction, and:

   c1) if said second list comprises no second event, said radionavigation installation (2) is not disassembled; and

   c2) if said second list comprises at least one second event relating to a malfunction, then all the second events of said second list are analyzed, and:

   α) if none of said second events relates to said radionavigation installation (2), then said radionavigation installation (2) is not disassembled; and

   β) if at least one of said second events relates to said radionavigation installation (2), then all the first events of said first list are analyzed, and:

   β1) if said first events make it possible to prove that the various malfunctions are due to problems relating to said data external to the aircraft (A), then said radionavigation installation (2) is not disassembled;

   β2) otherwise, said radionavigation installation (2) is disassembled.
2. The process as claimed in claim 1,
   characterized in that said steps a) and b) are implemented during the flight of the aircraft (A) and said step c) is implemented at the end of said flight, after the aircraft (A) has returned to the ground.
3. The process as claimed in one of claims 1 and 2,
   characterized in that said first events are recorded on a recording medium (8) of said radionavigation installation (2), and wherein said second events are recorded on a recording medium (11) of a system (5) of the aircraft (A), which receives information from said radionavigation installation (2).
4. The process as claimed in any one of the preceding claims,
   characterized in that said radionavigation installation (2) is a landing aid device of the aircraft (A) combined with a positioning system (6) based on satellites (S1, S2) and wherein said first events recorded represent the situations for which the external data received by said landing aid device (2) do not make it possible to supply a correct position indication of the aircraft (A).
5. The process as claimed in claim 4,
   characterized in that said first events represent at least the following situations:

   - the number of satellites (S1, S2), from which the radionavigation installation (2) receives data, is insufficient to compute a position of the aircraft (A);

   - the level of the radiofrequency signals received by said radionavigation installation (2) is below a predetermined value;

   - anomalies exist in navigation messages transmitted by a satellite (S1, S2) of said positioning system (6) ;

   - a satellite (S1, S2) of said positioning system (6) is excluded by a ground station (P1, P2) of said positioning system (6);

   - corrections supplied by a ground station (P1, P2) of said positioning system (6) are too old for a satellite (S1, S2) of said positioning system (6);

   - a ground station (P1, P2) of said positioning system (6) is not operational;

   - there exists a problem with the integrity of data supplied by a ground station (P1, P2) of said positioning system (6);

   - there exists a loss of a signal received from a ground station (P1, P2) of said positioning system (6) ;

   - there exists an error of transmission of a signal received from a ground station (P1, P2) of said positioning system (6); and

   - there exists a loss of a predetermined level of protection.
6. A maintenance device for a radionavigation installation (2) of an aircraft (A), said device including:

   - a second means of recording (10) for recording on a second recording medium (11) second events relating to malfunctions occurring on board the aircraft (A); and

   - a central unit (13) for making it possible to analyze recorded events so as to aid to determine whether said radionavigation installation (2) should or should not be disassembled,

   characterized in that it moreover comprises a first means of recording (7) for recording on a first recording medium (8) first events relating to data external to the aircraft (A), received by said radionavigation installation (2), and in that said central unit (13) is formed to receive said first and second events recorded in said first and second recording media (8,11) and to make it possible to analyze said first and second events so as to aid to determine whether said radionavigation installation (2) should or should not be disassembled.
7. The device as claimed in claim 6,
   characterized in that said first means of recording (8) is a means of recording of said radionavigation installation (2).
8. The device as claimed in one of claims 6 and 7,
   characterized in that said second means of recording (11) is a means of recording of a system (5) of the aircraft (A), which receives information from said radionavigation installation (2).
9. An aircraft,
   characterized in that it comprises a device (1) such as that as specified under any one of claims 6 to 8.
10. An aircraft,
    characterized in that it comprises a device (1) able to implement the process specified under any one of claims 1 to 5.

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