What functionality allows for the FMS to manage the navigation system?

The functionality that allows the Flight Management System (FMS) to manage the navigation system is referred to as Flight Path Management. This term encompasses the capabilities of the FMS to calculate and optimize the aircraft's flight path based on various inputs and parameters, including waypoints, airways, and performance data. The FMS uses these calculations to provide guidance to the autopilot and to manage the aircraft’s navigation throughout different phases of flight.

Flight Path Management is vital because it ensures that the aircraft follows a predetermined route efficiently and safely, adjusting for any changes in flight conditions, air traffic control instructions, or other factors. Thus, it plays a crucial role in integrating various navigation systems and providing a coherent strategy for managing the aircraft's trajectory from departure to arrival.

Autotune, while related to automatic adjustments, does not represent the full scope of navigation management handled by the FMS. Manual Override allows pilots to control the aircraft outside of automated systems, but does not directly manage navigation autonomously. The autopilot provides automatic control of the aircraft but relies on the FMS for navigation management, rather than being a standalone navigation management system.