Flight management assembly of an aircraft, of a transport aircraft in particular, and to a method of monitoring such a flight management assembly

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, wherein one of the flight management systems is an active flight management system and another of the flight management systems is a passive flight management system, and
• a monitoring and backup unit in communication with the two flight management systems, the monitoring and backup unit being configured for carrying out at least one monitoring of at least one of items of data generated by the active flight management system in order to verify if the item of data is valid,
• wherein the flight management assembly is configured for carrying out, in case of the monitored item of data being identified as valid, a synchronization of the monitoring and backup unit and of the passive flight management system, with data called synchronization data of the active flight management system corresponding to the item of data identified as valid, and
• wherein the flight management assembly is configured for computing guidance commands based on the item of data identified as valid.