Definition
A standardized system of visual markings and lighting changes used to indicate that a runway or taxiway is permanently closed and unusable for aircraft operations. For runways, large yellow Xs are placed at each end and at 1,000-foot intervals along the surface. For taxiways, a yellow X is placed at the entrance. All runway and taxiway lighting on the closed surface is disconnected so it cannot be illuminated, and the threshold markings, runway designation, and touchdown zone markings are obliterated.
Plain English
When a runway or taxiway is closed for good, it is marked with big yellow Xs and its lights are shut off so pilots can clearly see it must not be used.
Context Anchor
Seen when studying airport markings, reviewing an airport diagram, taxiing on the ground, or approaching an airport where old pavement may still be visible.
Why Pilots Care
Prevents pilots from mistakenly attempting to land or taxi on unusable surfaces, reducing risk of runway incursions or accidents.
Grounding Statement
If you see large yellow Xs on runway or taxiway pavement, treat that surface as closed and do not use it.
Intuition Check
Do not assume that “permanently closed” means the pavement will disappear or be blocked by a physical barrier. In this context, it means pilots are warned visually—mainly by yellow X markings and removed or disconnected lights—that the surface is no longer available for aircraft operations.
Example Sentence 1
On final approach, the pilot spotted a large yellow X on the runway and recognized it as permanently closed, so they sidestepped to the parallel runway.
Example Sentence 2
During preflight planning, pilots review the marking and lighting of permanently closed runways and taxiways on airport diagrams to avoid confusion at unfamiliar fields.