Definition
An auxiliary light unit installed along a runway that mirrors the signal of the runway centerline lighting (RCL) system, ensuring continuous visual guidance along the runway centerline during low-visibility operations.
Plain English
An extra centerline light that repeats what the main runway centerline lights are showing, so pilots always have an unbroken line of lights to follow down the middle of the runway.
Context Anchor
Seen in NOTAMs and facility status notices when communications equipment is unavailable or limited.
Derivation
‘Repeater’ comes from Latin ‘repetere,’ meaning ‘to do again.’ In lighting and signal systems, a repeater is a unit that reproduces a signal so it carries through without gaps. Here, the RCLR repeats the centerline lighting signal along the runway.
Why Pilots Care
In low-visibility takeoffs and landings, the centerline lights are sometimes the only reliable cue for staying aligned with the runway. A working repeater means that line of guidance stays unbroken; a NOTAM listing an RCLR outage tells the pilot a gap exists in that visual reference.
Intuition Check
Do not read RCLR as runway centerline lighting. In this contraction, it refers to communications relay equipment, not lights on the runway.
Example Sentence 1
The NOTAM reported an RCLR out of service on Runway 27L, leaving a short gap in the centerline lighting.
Example Sentence 2
Preflight checks confirmed the RCLR was powered and ready before night operations began.