When is a flight considered to be in the FLAT Track state?

A flight is considered to be in the FLAT Track state when the aircraft is within the set parameters. This is an important operational state for air traffic controllers as it indicates that the aircraft is maintaining a stable trajectory in terms of altitude, speed, and general flight path alignment. Being within these parameters helps ensure safe separation from other aircraft and allows for more predictable flight management.

In the context of radar operations, tracking an aircraft accurately within the FLAT Track state is crucial for maintaining situational awareness and enabling controllers to manage air traffic efficiently. This involves monitoring the flight's altitude and heading, and ensuring that it remains consistent with expected performance for the route.

The other choices describe conditions that may apply to a flight but do not encompass the specifics of the FLAT Track state. For instance, descending can occur outside of these set parameters, final approach refers specifically to landing phases rather than tracking stability, and a request for altitude change implies dynamic conditions that would not necessarily reflect the stability indicated by being in the FLAT Track state. Therefore, understanding this specific state is vital for effective air traffic control operations.