How does the FMGC manipulate data in the DUAL mode of operation?

In the DUAL mode of operation, the Flight Management and Guidance Computer (FMGC) system is designed to ensure high reliability and accuracy in flight data processing. The correct answer emphasizes that information is exchanged between both FMGCs for cross-comparison and validation, a crucial function that helps in error detection and increases the robustness of the flight management system.

This cross-comparison means that both FMGCs review and analyze the same set of input data, which allows them to identify discrepancies. If one FMGC receives data that significantly diverges from what the other FMGC processes, it can flag potential errors or anomalies for further investigation, thus enhancing safety and ensuring that both systems maintain alignment in their outputs. This way of operating interlocks the systems for a more accurate flight management process, which is vital for navigating and managing the aircraft effectively in different phases of flight.

In contrast to options that suggest a more isolated approach, the true strength of the DUAL mode lies in this cooperative functioning between the two FMGCs, ensuring they validate information against each other's outputs and correct any inconsistencies that might arise. Hence, the mechanism of information exchange leads to more reliable navigation and control, underlining the importance of redundancy in aviation systems.