When are lighting circuits disconnected and touchdown markings obliterated, with yellow crosses placed at each end of the runway and every 1,000 feet?

• A. Temporarily closed
• B. Permanently closed
• C. Under maintenance
• D. In use

Answer: (B)

The procedure of disconnecting lighting circuits, obliterating touchdown markings, and placing yellow crosses at each end of the runway and every 1,000 feet indicates that the runway is permanently closed. This action is taken to clearly communicate to pilots that the runway is no longer available for use in any capacity, thereby preventing any possible confusion.

When a runway is permanently closed, it's essential to eliminate any visual cues that suggest it might still be usable. By disconnecting the lighting circuits, removing touchdown markings, and adding yellow crosses, air traffic control is providing clear guidance to pilots about the runway's status. This is crucial for maintaining safety and ensuring that flight operations adhere to the latest airfield configurations.

In contrast, the other choices would imply temporary measures or ongoing operations, which do not necessitate the complete obliteration of markings and disconnection of lights. For instance, a temporarily closed runway might still feature some operational markings to indicate its status, while a runway under maintenance could still be used in limited capacity.