Definition
A row of flush-mounted lights installed along the centerline of a runway, spaced at regular intervals, used to provide visual guidance during takeoff and landing in low visibility or at night. The lights are white for most of the runway's length, then alternate white and red beginning 3,000 feet from the end, and finally turn solid red for the last 1,000 feet, giving the pilot a clear visual cue of remaining runway.
Plain English
Lights set into the surface of the runway down its middle. They help pilots see where the centerline is at night or in poor visibility, and the colors change near the end so pilots know how much runway is left.
Context Anchor
Seen on airport diagrams and used during night operations, instrument approaches, low-visibility landings, takeoffs, and rollout after touchdown.
Why Pilots Care
Keeps the aircraft centered on the runway surface, reducing the chance of veering off during low-visibility operations.
Intuition Check
RCL does not mean the painted centerline stripe. It means actual lights installed along the runway centerline.
Example Sentence 1
On the airport diagram, the symbol indicated that runway 27L was equipped with RCL, which the pilot relied on during the night landing.
Example Sentence 2
Even in light fog the RCL remained visible and guided the aircraft down the runway.