Runway status lights

9cMCO-Curved-RELs

Runway Status Lights (RWSL) operational concept

NTSB-Letter-2000-07-06

Single-THL

Runway Status Lights (RWSL) are a series of automated LED lighting systems installed on airport runways and taxiways to improve situational awareness and prevent runway incursions. RWSL enhances safety by providing real-time information about the status of a runway to pilots and vehicle operators, indicating when it is unsafe to enter, cross, or take off from a runway. The system is designed to reduce the risk of runway incursions, which are incidents involving the incorrect presence of an aircraft, vehicle, or person on the protected area of a surface designated for aircraft landing and take-off.

Overview

Runway Status Lights operate independently of Air Traffic Control (ATC) and are integrated with the airport's surface surveillance systems. The system uses radar and satellite technology to monitor the movement of aircraft and vehicles on the airport surface. When the system detects a potential conflict, such as an aircraft preparing to land on a runway that another aircraft is about to take off from, it automatically illuminates the RWSL to warn pilots and ground vehicle operators of the danger.

Components

The RWSL system consists of four main types of lights:

• Runway Entrance Lights (REL): Installed at taxiway/runway intersections, RELs illuminate red when it is unsafe to enter or cross a runway.
• Takeoff Hold Lights (THL): Located on the runway, THLs light up red to indicate that the runway is not safe for takeoff.
• Final Approach Runway Occupancy Signal (FAROS): Provides a visual warning to aircraft on final approach when the runway is occupied or otherwise unsafe for landing.
• Taxiway Crossing Lights (TCL): Similar to RELs, TCLs are installed at taxiway/runway intersections and illuminate red when it is unsafe to cross a particular section of the runway.

Operation

RWSL operates automatically without the need for human input, providing a direct warning to pilots and vehicle operators on the airport surface. The system is designed to function in all weather conditions, enhancing safety during low visibility when the risk of runway incursions is higher. The lights are bright enough to be visible during the day and can be dimmed at night to prevent glare.

Benefits

The primary benefit of Runway Status Lights is the significant enhancement of airport surface safety. By providing real-time, direct warnings to pilots and ground vehicle operators, RWSL helps prevent runway incursions, reducing the risk of accidents on the airport surface. The system also complements verbal communications from ATC, serving as an additional safety layer.

Implementation

As of the last update, RWSL systems have been installed in several major airports around the world, with plans for further installations. The implementation of RWSL is part of a broader effort by aviation authorities to enhance airport safety through technology.

Challenges

The installation and maintenance of RWSL systems involve significant costs and technical challenges, including integration with existing airport surveillance systems. Additionally, training is required for pilots, air traffic controllers, and ground vehicle operators to understand and respond appropriately to RWSL indications.