Definition
A series of brilliant, sequenced flashing white lights installed along the centerline of an approach lighting system, firing in rapid succession from the farthest light toward the runway threshold to give the pilot a strong visual lead-in cue during an instrument approach. The flashes appear as a ball of light traveling toward the runway, which is why pilots commonly call them the rabbit.
Plain English
Bright strobe lights along the approach path that flash one after another, racing toward the runway, so the pilot can quickly find and line up with the runway when breaking out of cloud or low visibility.
Context Anchor
Seen in instrument approach lighting discussions, especially when describing the lights a pilot may see near the runway end during the transition from instruments to outside visual cues.
Derivation
High-intensity refers to the very bright output of the strobes, needed to be seen through cloud, rain, or haze. Flasher comes from the rapid on-off pulse of each light. Together: a system of very bright pulsing lights.
Why Pilots Care
Provides immediate visual alignment cues that reduce the chance of runway misalignment or a missed approach in marginal weather.
Grounding Statement
On a dark or hazy approach, the flashers can catch your eye before the runway itself is easy to see and lead your attention toward the runway.
Intuition Check
Do not read “flasher” as an emergency warning light. Here it means bright approach lights that flash in a planned pattern to help guide your eyes toward the runway.
Example Sentence 1
As we descended through the cloud base, the high-intensity flasher system was the first thing we saw, leading us straight to the threshold.
Example Sentence 2
In the low ceiling, the high-intensity flasher system gave the crew a clear rolling light path that led them to the runway numbers.