Maintenance process and device for a radionavigation installation of an aircraft

1. A maintenance process for a radionavigation installation of an aircraft, said process comprising:

a) recording in a first list, as appropriate, first events relating to data external to the aircraft, received by said radionavigation installation;

b) recording in a second list, as appropriate, second events relating to malfunctions occurring on board the aircraft;

c) performing a check 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, refraining from disassembling said radionavigation installation; and

c2) if said second list 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 relates to said radionavigation installation, refraining from disassembling said radionavigation installation; and

β) if at least one of said second events relates to said radionavigation installation, analyzing all the first events of said first list, and:

β1) if said first events make it possible to prove that the various malfunctions are due to problems relating to said external radionavigation data, refraining from disassembling said radionavigation installation;

β2) otherwise, disassembling said radionavigation installation.

2. The process as claimed in claim 1 , wherein said steps a) and b) are implemented during a flight of the aircraft and said step c) is implemented at the end of said flight, after the aircraft has returned to the ground.

3. The process as claimed in claim 1 , wherein said first events are recorded on a recording medium of said radionavigation installation, and wherein said second events are recorded on a recording medium of a system of the aircraft, which receives information from said radionavigation installation.

4. The process as claimed in claim 1 , wherein said radionavigation installation is a landing aid device of the aircraft combined with a positioning system based on satellites and wherein said first events recorded represent situations for which the external data received by said landing aid device do not make it possible to supply a correct position indication of the aircraft.

5. The process as claimed in claim 4 , wherein said first events represent at least the following situations:

a number of the satellites from which the radionavigation installation receives data, is insufficient to compute a position of the aircraft;

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

anomalies exist 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 supplied 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 exists a problem with the integrity of data supplied by a ground station of said positioning system;

there exists a loss of a signal received from a ground station of said positioning system;

there exists an error of transmission of a signal received from a ground station of said positioning system; and

there exists a loss of a predetermined level of protection.

6. A maintenance device for a radionavigation installation of an aircraft, which device comprises:

a first recordation section that records on a first recording medium a first list of first events relating to data external to the aircraft, received by said radionavigation installation;

a second recordation section that records on a second recording medium a second list of second events relating to malfunctions occurring on board the aircraft; and

a section that enables analysis of said first and second events recorded on said first and second recording media, so as to determine whether said radionavigation installation should or should not be disassembled, wherein:

if said second list comprises no second event, said radionavigation installation is not disassembled; and

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:

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

if at least one of said second events relates to said radionavigafion installation, then all the first events of said first list are analyzed, and:

if said first events make it possible to prove that the various malfunctions are due to problems relating to said external radionavigation data, then said radionavigation installation is not disassembled; and

otherwise, said radionavigation installation is disassembled.

7. The device as claimed in claim 6 , wherein said first recordation section records said radionavigation installation.

8. The device as claimed in claim 6 , wherein said second recordation section records a system of the aircraft, which receives information from said radionavigation installation.

9. An aircraft, which comprises a device such as that as specified under claim 6 .

10. An aircraft, which comprises a device able to implement the process specified under claim 1 .