Final answer:
When a runway or part of a runway is closed, markings should be placed at the threshold or both ends of the closed runway, and at any intersecting runways that are still open, depending on the length of the runway.
Step-by-step explanation:
When a runway or part of a runway is closed, markings should be placed to indicate the closure and guide pilots. The location of the markings depends on the length of the runway:
- For a runway greater than 4,000 feet in length: The closure markings should be placed at the threshold or both ends of the closed runway, and at any intersecting runways that are still open.
- For a runway greater than 1,500' but less than or equal to 4,000' in length: The closure markings should be placed at the threshold or both ends of the closed runway, and at any intersecting runways that are still open.
- For a runway 1,500' or less in length: The closure markings should be placed at the threshold or both ends of the closed runway, and at any intersecting runways that are still open.