What are Runway Status Lights (RWSL)?

• A. A weather alert system for runway conditions
• B. A display of landing minimums for pilots
• C. A navigation aid that guides aircraft with in-cabin displays
• D. A fully automated system that provides runway status information to pilots and surface vehicle operators to clearly indicate when it is unsafe to enter, cross, takeoff from, or land on a runway.

Answer: (D)

Runway Status Lights are an automated visual system that communicates when a runway is not safe to enter, cross, take off from, or land on. When the runway is occupied or otherwise unsafe, red lights illuminate to clearly indicate stop or no-use status to pilots and surface vehicle operators. The system works automatically, using sensors and airfield data to provide real-time status without relying on verbal clearances. This helps prevent runway incursions by giving an unambiguous, outside-the-cockpit cue about runway safety. It’s not a weather alert system, not a display of landing minimums, and not a cockpit navigation aid; it’s a dedicated safety indicator for runway use.