Where are flights in hold displayed in the ACL?

Flights in hold are displayed in the Active Control List (ACL) under the section labeled as SPA. SPA stands for 'Special Procedures Area,' which specifically tracks and monitors flights that are currently in a holding pattern. This is essential for air traffic controllers and operational staff to maintain situational awareness and ensure efficient management of air traffic, particularly during peak times or when conditions necessitate holding patterns for safety and orderliness.

The other options, while they may represent different components or areas in radar operations, do not specifically indicate where holding flights are recorded. The ability to quickly identify flights that are in a holding state is vital for effective air traffic management and for making timely decisions regarding the flight's next maneuver.