What is the vertical airspace of a Terminal Control Area of Responsibility?

The vertical airspace of a Terminal Control Area (TCA) typically extends from the surface up to a specified upper limit, which varies by location. In this context, the correct answer states that the TCA extends from the surface to FL230 (Flight Level 230), which is equivalent to 23,000 feet above sea level.

This range is designed to provide safe and organized air traffic management in regions where there are significant aircraft operations, particularly around busy airports. It allows for sufficient altitude separation between departing and arriving aircraft, as well as accommodating air traffic en route to higher altitudes.

The choice indicating a vertical limit of FL150 (15,000 feet) or lower would not suffice to effectively manage the density of air traffic typical in terminal areas. Meanwhile, limits extending to FL300 (30,000 feet) might be too high for most operations in terminal control areas, where the traffic is usually concentrated below that altitude. The upper limit of FL230 thus strikes a balance between accommodating a healthy volume of air traffic while maintaining a safe operational corridor for aircraft.