Answer :
Final answer:
The last 3000ft of the runway centerline lights change from white to alternating red and white for the next 2000ft, then to all red for the final 1000ft, providing crucial visual cues for pilots.
Explanation:
The color coding configuration of the runway centerline lights for the last 3000 feet of the usable runway is designed to provide visual cues to pilots during landing and takeoff operations, especially in low visibility conditions.
The last 3000 feet of the runway centerline lights have a specific color sequence: the colors change from white to red and white for the next 2000 feet, and then to all red for the final 1000 feet. This configuration helps pilots in determining their remaining distance on the runway and when to commence the take-off or finalize the landing phase.
Initially, the runway centerline lights are white along the runway. However, to warn pilots that they are getting close to the end of the usable runway, a color transition occurs. Specifically, for the last 3000 feet, a sequential change in color coding begins.
At 3000 feet, the lights start with alternating red and white lights for 2000 feet. Then, for the final 1000 feet of the runway, the lights are all red, signaling an imminent end to the runway. This color configuration serves as an important safety feature for pilots during both takeoff and landing, ensuring a higher level of situational awareness.