What color are Runway End Lights and what do they define?

Runway End Lights are colored yellow, and they are specifically used to indicate the end of the operational runway surface. These lights are typically positioned at the departure end of the runway and serve to provide visual guidance to pilots, especially during takeoff and landing phases. By marking the runway's end, these lights help in preventing aircraft from unintentionally overrun the runway.

Understanding the function of runway end lights is essential for pilots and air traffic controllers, as this knowledge directly impacts flight safety and operational efficiency. The visibility of these lights, particularly during low visibility scenarios, is crucial for ensuring that aircraft are aware of their position relative to the runway limits.