Definition
A runway that is unavailable for aircraft operations. A closed runway is marked with a yellow X at each end (and sometimes at intervals along its length), and may be closed temporarily for maintenance, construction, snow removal, or other reasons, or permanently when no longer in use.
Plain English
A runway that pilots are not allowed to use. It is marked with a large yellow X so it can be seen from the air and the ground.
Context Anchor
Seen in airport information, pilot notices, air traffic control instructions, and runway markings such as a large X placed on or near the runway.
Derivation
Closed comes from the everyday idea of something being shut and not open for use. In aviation, it points to official runway availability: the runway is not open to aircraft, even if the pavement is still physically there.
Why Pilots Care
Using a closed runway risks accidents, aircraft damage, and violations of safety regulations.
Intuition Check
Closed does not just mean the runway looks empty or quiet. In FAA use, a closed runway is officially not available for aircraft operations until the proper airport authority reopens it.
Example Sentence 1
The pilot reviewed the NOTAMs and noted that Runway 9 was a closed runway due to resurfacing work.
Example Sentence 2
Controllers directed all aircraft away from the closed runway during the construction period.