CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to French patent application number 18 56082 filed on Jul. 2, 2018, the entire disclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The disclosure herein relates to a flight management assembly of an aircraft, of a transport aircraft in particular, and to a method of monitoring such a flight management assembly.

BACKGROUND

The disclosure herein applies to a flight management assembly comprising two flight management systems, of the FMS type (“FMS” standing for “Flight Management System” in English).

The items of hardware installed on board an aircraft and notably the flight management assembly must make it possible to attain the required level of safety, in particular if the aircraft must implement RNP AR operations (“RNP AR” standing for “Required Navigation Performance with Authorization Required” in English). These RNP AR operations are based on area navigation of the RNAV type (“RNAV” standing for “aRea NAVigation” in English) and on operations of the RNP type (“RNP” standing for “Required Navigation Performance” in English).

Now, in order that an aircraft may have the capability of flying according to such RNP AR procedures, it is notably necessary to be able to eliminate an erroneous source of computation of guidance commands (or instructions) from the guidance loop in order to counter its possible effects on the trajectory of the aircraft. With a flight management assembly having two flight management systems, in the case of a disagreement between the two flight management systems, the assembly is not capable of identifying which one of them is defective, and the aircraft can therefore no longer be guided in automatic mode and is not capable of implementing such RNP operations.

In such a flight management assembly having two flight management systems, it is therefore necessary to be able to carry out processings and/or verifications allowing the aircraft to use accurate data in order to overcome the aforementioned disadvantage.

SUMMARY

The purpose of the disclosure herein is to overcome this disadvantage. It relates to a flight management assembly of an aircraft, the flight management assembly comprising two flight management systems, each of the flight management systems being configured for generating data comprising at least one trajectory and at least one prediction of a parameter of the aircraft.

According to the disclosure herein, one of the flight management systems is called active (or master) and the other one is called passive (or slave), the flight management assembly comprising, moreover, a monitoring and backup unit, this monitoring and backup unit being configured for carrying out at least one monitoring of at least one of the items of data generated by the active flight management system in order to verify if the item of data is valid, and the flight management assembly is configured for carrying out, in the case of validation of the monitored item of data, a synchronization of the monitoring and backup unit and of the passive flight management system, with data called synchronization data (described below) of the active flight management system.

Thus, thanks to this architecture, the monitoring unit by monitoring the active (or master) flight management system is capable of validating data (notably with the use of an increased integrity database, as described below), and in the case of validation, the monitoring and backup unit and the other (passive or slave) flight management system are synchronised with the active flight management system, that is to say they receive validated data. Thus, the three entities (the two flight management systems and the monitoring and safety unit) use the same data which are valid, in particular for computing guidance commands as described below, which notably makes it possible for the aircraft to have the capability of flying RNP operations such as mentioned above, and to overcome the abovementioned disadvantage.

Advantageously, the flight management assembly comprises at least a first database used by the flight management systems for computing at least some of the data, and a second database used by the monitoring and backup unit for carrying out the monitoring, the second database having an integrity (preferably of the DPAL1 type) greater than that (preferably of the DPAL2 type) of the first database.

Moreover, advantageously, the active flight management system is configured for computing a lateral trajectory, as a function of at least a reference flight plan and of meteorological data (notably positions of meteorological events), and the monitoring and backup unit is configured for verifying the validity of the lateral trajectory, with regard to the meteorological data.

Moreover, advantageously, the active flight management system is configured for computing a vertical trajectory along a lateral trajectory and from meteorological data, as a function of a safe altitude profile depending on the lateral trajectory, and the monitoring and backup unit is configured for verifying the validity of the vertical trajectory, with regard to the meteorological data (in particular the positions of meteorological events) and to a safe altitude profile extracted from a safe altitude database.

Moreover, advantageously, the active flight management system is configured for computing a first prediction of fuel on board the aircraft, along a validated lateral trajectory and a validated vertical trajectory, on the basis of data coming from a first database (preferably of the DPAL2 type) and the monitoring and backup unit is configured for computing a second prediction of fuel on board the aircraft, along the validated lateral trajectory and along the validated vertical trajectory, on the basis of data coming from a second database (preferably of the DPAL1 type) and the monitoring and backup unit is configured for verifying the validity of the first prediction of fuel on board the aircraft, with regard to the second prediction of fuel on board the aircraft.

Moreover, advantageously, the flight management assembly is configured for carrying out a synchronization of the monitoring and backup unit and of the flight management system with at least one of the following items of synchronization data of the active flight management system:

a flight plan;

a validated lateral trajectory and a validated vertical trajectory.

Moreover, advantageously, the flight management assembly comprises switching configured for, in the case of a failure of the active flight management system or in the case of detection by the monitoring and backup unit of an invalid active flight trajectory, generating a switching consisting of or comprising making the passive flight management system active and of making the active flight management system passive.

Moreover, in a particular embodiment, the two flight management systems are hosted in first and second items of hardware of a same first type, and the monitoring and backup unit is hosted in a third item of hardware different from the first and second items of hardware, the third item of hardware being of a second type different from the first type.

Moreover, advantageously, the two flight management systems and the monitoring and backup unit are each configured for determining guidance commands, the guidance commands being transmitted to a user system.

Moreover, advantageously, the monitoring and backup unit is configured for being able to display a so-called backup trajectory.

The disclosure herein also relates to a method of monitoring a flight management assembly, such as the one described above, which comprises two flight management systems one of which is active and the other of which is passive, and a monitoring and backup unit.

According to the disclosure herein, the monitoring method comprises the following successive steps:

a step of generation of data comprising at least one trajectory and at least one prediction of a parameter of the aircraft, used by at least the flight management system which is active;

a monitoring step, implemented by the monitoring and backup unit, consisting of or comprising carrying out at least a monitoring of at least one of the items of data generated by the active flight management system in order to verify if the item of data is valid; and

a synchronization step consisting of or comprising carrying out, in the case of validation of the monitored item of data, a synchronization of the monitoring and backup unit and of the passive flight management system, with so-called synchronization data of the active flight management system.

Advantageously:

the data generation step consists of or comprises computing a lateral trajectory, as a function of at least a reference flight plan and of meteorological data; and

the monitoring step consists of or comprises verifying the validity of the lateral trajectory, with regard to the meteorological data.

Moreover, advantageously:

the data generation step consists of or comprises computing a vertical trajectory along a

lateral trajectory, as a function of a safe altitude profile depending on the lateral trajectory and on meteorological data; and

the monitoring step consists of or comprises verifying the validity of the vertical trajectory, with regard to the meteorological data and to a safe altitude profile extracted from a safe altitude database.

Moreover, advantageously:

the data generation step consists of or comprises computing a first prediction of fuel on board the aircraft, along a validated lateral trajectory and along a validated vertical trajectory, on the basis of data coming from a first database; and

the monitoring step consists of or comprises verifying the validity of the first prediction of fuel on board the aircraft, with regard to a second prediction of fuel on board the aircraft, along the validated lateral trajectory and the validated vertical trajectory, the second prediction being computed on the basis of data coming from a second database.

The disclosure herein also relates to an aircraft, in particular a transport aircraft, which is provided with a flight management assembly such as the one specified above.

