The majority of airports have some type of lighting to identify and mark taxiways and runways and to control movements of aircraft and vehicles. The variety and type of lighting systems depends on the volume and complexity of operations at a given airport. Airport lighting is standardized so that airports use the same light colors for runways and taxiways.
The design and usage of civil airport lighting are provisions are addressed by:
International Civil Aviation Organisation (ICAO):
- ICAO Annex 14-1 Aerodromes Volume I, Aerodrome Design and Operations
- ICAO Annex 14-2 Aerodromes volume II, Heliports
U.S. Federal Aviation Administration (FAA):
International Electrotechnical Commission, IEC:
Control of Airport Lighting
Airport lighting is controlled by air traffic controllers (ATCOs) at towered airports. At non-towered airports, the lights may be on a timer, or where a Flight Service Station (FSS) is located at an airport, the FSS personnel may control the lighting. A pilot may request various light systems be turned on or off and also request a specified intensity, if available, from ATC or FSS personnel. At selected non-towered airports, an ARCAL (Aircraft Radio Control of Aerodrome Lighting) system is installed. This system allows the pilot to control the lighting by using the aircraft radio. This is done by selecting a specified frequency and clicking the radio microphone a specified number of times within a specified time period (for example, 7 "clicks" within 5 seconds on frequency 121.7).
Omnidirectional taxiway lights outline the edges of the taxiway and are blue in color. At many airports, these edge lights may have variable intensity settings that may be adjusted by an air traffic controller when deemed necessary or when requested by the pilot. Some airports also have taxiway centerline lights that are green in color.
Light Colours and Their Meanings at Runway Entrances
||RED lights ahead of an aircraft or vehicle mean: it is unsafe to proceed beyond the RED lights. This is the case regardless of whether the lights are fixed, alternating or flashing and is independent of an ATC clearance. RED means stop.
||AMBER lights are used to convey a similar but less distinct message. They indicate that a potential hazard exists beyond the lights, but that in conjunction with an appropriate ATC clearance it will be safe to proceed.
||GREEN lights are often used to indicate the route to be followed by an aircraft or vehicle, particularly at night or in periods of reduced visibility. In all cases green lights are a routing aid and must only be followed in conjunction with an ATC clearance.
Approach Light Systems
Approach light systems are primarily intended to provide a means to transition from instrument flight to visual flight for landing. The system configuration depends on whether the runway is a precision or nonprecision instrument runway. Some systems include sequenced flashing lights, which appear to the pilot as a ball of light traveling toward the runway at high speed. Approach lights can also aid pilots operating under VFR at night.
Visual Glideslope Indicators
Visual glideslope indicators provide the pilot with glidepath information that can be used for day or night approaches. By maintaining the proper glidepath as indicated by the system, a pilot should have adequate obstacle clearance and should touch down within a specified portion of the runway:
- Visual Approach Slope Indicator (VASI)
- Precision Approach Path Indicator (PAPI)
There are various lights that identify parts of the runway complex. See the separate article Runway Lighting for more details.
Lights Protecting the Runway
Lights on runways and at runway holding points have been developed to deliver warnings and status indications to pilots and manoeuvring area vehicle drivers. See the separate articles: Runway Holding Point Lighting and Runway Status Lights (RWSL).
In the United States, airport beacons are used to help pilots identify an airport at night. The beacons are operated from dusk till dawn. Sometimes they are turned on if the Ceiling is less than 1,000 feet and/or the ground visibility is less than 3 statute miles (VFR minimums). However, there is no requirement for this, so a pilot has the responsibility of determining if the weather meets VFR requirements. The beacon has a vertical light distribution to make it most effective from 1–10° above the horizon, although it can be seen well above or below this spread. The beacon may be an omnidirectional capacitor-discharge device, or it may rotate at a constant speed, which produces the visual effect of flashes at regular intervals. The combination of light colors from an airport beacon indicates the type of airport. Some of the most common beacons are:
- Flashing white and green for civilian land airports;
- Flashing white and yellow for a water airport;
- Flashing white, yellow, and green for a heliport; and
- Two quick white flashes alternating with a green flash identifying a military airport.