One of airports’ most notable safety aspects is their thorough lighting infrastructures. Aircraft, buildings, runways, and taxis all feature special lighting fixtures. It is vital for airports to be sufficiently lit at all times that the FAA has regulations on lighting requirements. The runway is one of the most important airport areas to keep lit. Functional runway lights are essential to a safe landing, keeping the landing strip visible and signaling crucial landmarks along the runway pavement.
According to the FAA Airfield Standards, there are nine color combinations of lighting to be found on airport runways and taxiways.
Runway Edge Lights
Runway Edge Lights are used to light up the edges of the runway during periods of low visibility like nighttime or foggy weather. For most of the runway, the edge lights are white. However, the color shifts as the runway comes nearer to the end. Typically, yellow lights are used for the last 2,000 feet or half the runway length (whichever is less).
Runway End Lights
At the very end, red or green lights are used. Red lights are faced inwards and signal the end of a runway, and green lights are faced outwards and signal the approaching start of a runway.
Runway End Identifier Lights (REIL)
Also at the end of the runway are Runway End Identifier Lights (REIL). These lights are a system of two synchronized, unidirectional flashing lights placed on each corner of the runway end. These are used to aid pilots in identifying the end of the runway.
Centerline Lights are white lights that line the center of a runway. Like runway edge lights, they are primarily white until towards the end of the runway. In the final 1000 feet, Centerline Lights begin to alternate white and red before transitioning into a completely red layout.
Touchdown Zone Lights
Touchdown Zone Lights are repeating groups of three white lights that cover the last 3000 feet of the runway. These light clusters are to alert pilots of the touchdown zone of the runway.
Taxiway Edge Lights and Taxiway Centerline Lights
Taxiway Edge Lights are bright blue lights placed along the taxiway’s edge. While the taxiway is not part of a runway, the distinction between the two lights should be known as they may otherwise be easily confused by airport and aircraft personnel.
Taxiways also have centerline lights lined similarly to runway centerline lights but green.
Taxiway Lead On/Lead Off Lights
These lights signal the junction between a runway and a taxiway. Taxiway Lead On/Lead Off Lights alternate between green and yellow and guide pilots from the centerline of the runway to the centerline of a taxiway.