Coming to Terms with Airfield Lighting

Key Definitions for Airfield Lighting

Landing lights, liftoff area, low-intensity, leads? What’s the difference between a heliport, helipad, or helideck?

In terms of airfield lighting related jargon, there’s an entire language around the airport and the products used there. We’ve compiled key terms and provided definitions for common airfield and heliport lighting terms in this official Flight Light – Airfield Lighting Glossary.

Airfield Lighting Glossary

Common Terms Defined

Aircraft – A device that is used or intended to be used for flight in the air.

Airport  – An area where aircraft take off and land, usually equipped with landing strips, control tower, hangars, refueling and maintenance facilities, and accommodations for passengers and cargo.

AirfieldAn area of fields and runways where aircraft take off and land, like and airport or airbase, usually without regularly schedule commercial flights, such as those at military bases or small fields for private aircraft.

Approach Lighting System (ALS) A lighting system installed on the approach end of an airport runway and consists of a series of light bars, strobe lights, or a combination of the two that extends outward from the runway end.

Approach PathThe final approach (also called the final leg and final approach leg) is the last leg in an aircraft’s approach to landing, when the aircraft is lined up with the runway and descending for landing.

Apron  – The airport apron, apron, flight line, ramp, or tarmac is the area of an airport where aircraft are parked, unloaded or loaded, refueled, or boarded. Although the use of the apron is covered by regulations, such as lighting on vehicles, it is typically more accessible to users than the runway or taxiway.

Base CanAn in-ground metal enclosure that supports a lighting fixture, houses its electrical components, and facilitates future maintenance.

BeaconAn aerodrome beacon or rotating beacon or aeronautical beacon is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night. An aerodrome beacon is mounted on top of a towering structure, often a control tower, above other buildings of the airport.

Beacon lights have different color combinations that indicate the type of airport it is lighting

  • The color and number of lights for different airports are as follows:
  • White and Green — Lighted land airport
  • Green alone — Lighted land airport
  • White and Yellow — Lighted water airport
  • Yellow alone* — Lighted water airport
  • Green, Yellow, and White — Lighted heliport
  • White, White, Green** — Military Airport
  • White, Green, Amber — Hospital and/or Emergency Services Heliport
*Green alone or yellow alone is used only in connection with a white-and-green or white-and-yellow beacon display, respectively.
**Military airport beacons flash alternately white and green, but are differentiated from civil beacons by two quick white flashes between the green flashes.

Center Line – This is a line in the center of a taxiway/runway that helps pilots taxi aircraft on taxiways safely. Center line lights are white with red as the runway nears the end.

Cramp’s Helipad Approach Path Indicator (CHAPI) – Airfield based product that gives visual aid to pilots in order to ensure a safe approach path. Also used in heliports. Developed by training captain Dave Cramp with Bristow Helicopters in Dubai to help reinforce a 6 degree glide slope to aid in helicopter landings.

Clearance Bar Lights Three in-pavement steady-burning yellow lights installed at holding positions on taxiways.

Controller A product that provides power to lighting systems. Controllers ensure that power does not overload the lamps and other products and are designed to maximize performance, energy efficiency, and safety.

Compliance (UL Listed, ISO 9001, FAA, ICAO)Compliant products have met or exceeded standards and expectations in order to be granted a specific accreditation. Products are granted compliance based on their  specific configurations.

Current Driven A type of circuit that requires constant output.

Displaced Threshold A portion of the runway shown by markings and lights that show where the beginning of the runway starts. Displaced portion of the Threshold is where it is not safe for airplanes to land.

Elevated Lights – Lighting fixtures installed with light source above ground level.

Federal Aviation Administration (FAA) The United States’ governmental body which is responsible for airplanes/airports. The requirements for FAA products ensure they are of the highest quality and make sure that air travel in the USA is as safe as possible.

Frangible Coupling – A coupling designed to shear or break away cleanly on impact. This minimizes the damage to aircraft, signs, elevated lights, navigational/approach aids, and protects mounting flanges or floor flanges after an incident.

Ground LightSee inpavement lights.

Inpavement Lights Lighting fixtures installed with light source flush with the ground or recessed below ground level. Also known as a ‘ground light’.

International Organization for Standardization (ISO) – The International Organization for Standardization (ISO) credential was created to help build trust between customers and companies all over the world. It is an expectation of both quality products as well as all aspects of how a business is managed.

Inset Lights Lighting fixtures installed with light source flush with the ground or recessed below ground level.

Lamps The bulbs within airfield lights, especially runways lights. Typically found in the following levels of intensity, based on photometric performance:

  • High Intensity
  • Low Intensity
  • Medium Intensity

Land and Hold Short Lights (LAHSO) A row of white pulsating lights installed across the runway to indicate hold short position on some runways that are facilitating land and hold short operations (LAHSO).

Lighting, AirfieldA line of lights on an airfield or elsewhere to guide aircraft in taking off or coming in to land or an illuminated runway is sometimes also known as a flare path.

Obstruction Lights – A type of light to ensure air traffic is aware of large structures (radio towers, smoke stacks, cranes, etc.) at night.

Precision Approach Path Indicator (PAPI) – A precision approach path indicator is a visual aid that provides guidance information to help a pilot acquire and maintain the correct approach for landing at an airport or an aerodrome. It is generally located on the left-hand side of the runway approximately 984 ft (300 m) beyond the landing threshold of the runway.

Regulators A product that is in control of sending the proper amount of electricity to the airfield lights to provide precision control of runway lighting circuits.

Runway Strip of level, usually paved ground on which aircraft take off and land. Runways may be a man-made surface (often asphalt, concrete, or a mixture of both) or a natural surface (grass, dirt, gravel, ice, sand or salt). Runways, as well as taxiways and ramps, are sometimes referred to as “tarmac”, though very few runways are built using tarmac. 

Runway Lights – Runway lighting are used at airports for use at night and low visibility. Seen from the air, runway lights form an outline of the runway.

Runway Centerline Lighting System (RCLS)A system of lights embedded into the surface of the runway at 50 ft (15 m) intervals along the runway centerline on some precision instrument runways. The lights are typically white except the last 2,952 ft (900 m) then alternate white and red for next 1,969 ft (600 m) and red for last 984 ft (300 m).

Runway End Identifier Lights (REIL)A system of unidirectional (facing approach direction) or omnidirectional pair of synchronized flashing lights installed at the runway threshold, one on each side.

Runway Edge LightsA series of white elevated lights that run the length of the runway on either side at a maximum spacing of 200 ft (61 m) intervals. On precision instrument runways, the edge-lighting becomes amber in the last 2,000 ft (610 m) of the runway, or last third of the runway, whichever is less.

Runway edge lights generally are classified by their intensity – low, medium, and high. Many runways have variable intensity lights that can emit low, medium, or high intensity light.

Low Intensity Runway Lights (LIRL)
Medium Intensity Runway Lights (MIRL)
High Intensity Runway Lights (HIRL)

Runway Guard Lights – Either a pair of elevated flashing yellow lights installed on either side of the taxiway, or a row of in-pavement yellow lights installed across the entire taxiway, at the runway holding position marking at taxiway/runway intersections.

Stop Bar Lights A row of red, unidirectional, steady-burning in-pavement lights installed across the entire taxiway at the runway holding position, and elevated steady-burning red lights on each side used in low visibility conditions (below 1,200 ft RVR). A controlled stop bar is operated in conjunction with the taxiway centerline lead-on lights which extend from the stop bar toward the runway. Following the ATC clearance to proceed, the stop bar is turned off and the lead-on lights are turned on.

Taxiway – A taxiway is a path for aircraft at an airport connecting runways with aprons, hangars, terminals and other facilities. They mostly have a hard surface such as asphalt or concrete, although smaller general aviation airports sometimes use gravel or grass. Most airports do not have a specific speed limit for taxiing.

Taxiway Edge LightsA series blue elevated lights that outline the edge of a taxiway during periods of darkness or restricted visibility conditions.

Taxiway LightsA range of different lighting fixtures used on the taxiway. May be elevated or in-pavement and typically emit blue light – or green, yellow or red light depending on the application. 

At a four-way intersection, the light at the center of the crossing may be omnidirectional and emit yellow light. Where a road for ground vehicles only meets a taxiway or at an end of usable service area for a ramp or taxiway, the light at the edge of the road or the final taxiway edge light may emit red light.

Taxiway Centerline LightsA series of steady burning inset lights located along the taxiway centerline, typically green depending on the width of the taxiway, and the complexity of the taxi pattern.

Where a taxiway crosses a runway, or where a “lead-off” taxiway centerline leads off of a runway to join a taxiway, these lights will alternate yellow and green.

Taxiway Centerline Lead-Off Lights A series of alternating green and yellow lights embedded into the runway pavement installed along lead-off markings. It starts with green light at about the runway centerline to the position of first centerline light beyond the Hold-Short markings on the taxiway.

Taxiway Centerline Lead-On Lights A series of lights installed the same way as taxiway centerline lead-off lights, but directing airplane traffic in the opposite direction.

Threshold – The markings/area at the start of the runway where the beginning of a safe landing can occur.

Touchdown ZoneThe area of the runway that an aircraft first makes contact.

Touchdown Zone Lights  A row of white light bars (with three in each row) at 98 or 197 ft (30 or 60 m) intervals on either side of the centerline for 2,952 ft (900 m).

UL Listed (UL)UL listed products have met a high standards of safety to ensure –businesses and customers have quality products and commerce.

VoltageVoltage is the difference in electric potential between two points, a relevant unit of measurement for rating lights. Different lamps and configurations require different amounts of voltage.

WaterwaysRunways made of water used for seaplanes.

Wind Cones – A product that indicates wind speed and direction. Normally bright orange, and often needs to be lit at night.