The terminal arrival area (TAA) is based on a radius of how many miles from the Initial Approach Fix?

The terminal arrival area (TAA) is defined as a designated airspace of 30 nautical miles radius from the Initial Approach Fix (IAF). This area is essential for transitioning aircraft from the enroute phase of flight to the approach phase, helping to mass aircraft in an organized flow towards the final approach. The use of a 30-mile radius allows for effective management of air traffic and ensures that controllers can maintain adequate separation between arriving aircraft.

In practice, this means that when an aircraft is within this TAA, it can receive instructions and guidance that facilitate a safe and efficient descent and approach to the airport, aligning with standard procedures that optimize airport capacity and safety. This specification is critical for ATC operations because it allows for predictable flight paths and enhances situational awareness for both controllers and pilots.

Other options do not align with the defined standard for the TAA, making 30 nautical miles the correct and standard measure used in air traffic control practices.