When should the Autothrottle AIRSPEED mode be used?

The Autothrottle AIRSPEED mode is designed to maintain a specific airspeed under certain conditions. This mode allows the autothrottle system to automatically adjust the thrust to keep the aircraft at the desired airspeed. Using this mode when Flight Level Change (FLC) is switched off ensures that the autothrottle can operate freely without interference from additional flight path guidance that FLC might provide.

In the context of using the autothrottle effectively, it is important to manage the flight settings appropriately. With FLC off, the pilot has taken manual control over the climb or descent, while still allowing autothrottle to adjust thrust based on the airspeed. This combination provides greater flexibility and control to the pilot, as they can directly influence the vertical performance of the aircraft while relying on autothrottle for speed management.

The other scenarios suggested in the incorrect choices would not permit the Autothrottle AIRSPEED mode to function optimally or as intended. For instance, using it only during descent or landing would limit its functionality, as maintaining airspeed is essential during all phases of flight, not just during descent. Similarly, with FLC activated, the autothrottle's inputs could conflict with the guidance provided by the Flight Guidance Panel. Therefore