How is a closed runway represented on an airfield diagram?

A closed runway is represented on an airfield diagram by placing an "X" at the ends of the runway. This symbol indicates that the runway is not available for use, signaling to pilots that they should not attempt to land or take off on that particular runway segment. The "X" is a universally recognized symbol in aviation for closed or unusable runways, ensuring that there is clear communication regarding runway status to maintain safety and operational efficiency.

While other symbols may represent different airfield features or conditions, the "X" specifically conveys that the runway should be avoided, making it an essential part of airfield navigation and planning. This visual representation assists pilots in making informed decisions while approaching the airfield, particularly in situations where multiple runways are in close proximity.