Key Terminology
- Approach Lighting System (ALS) – Lighting system located at the approach end of a runway consisting of a series of light bars, strobe lights, or a combination of the two, which extend outward from the runway end.
- Arc Blast – Tremendous temperatures of the arc cause the explosive expansion of both the surrounding air and the metal in the arc path. Dangers associated with arc blast include high pressure, sound, and shrapnel.
- Arc Flash – Electric current passes through air between ungrounded conductors or between ungrounded conductors and grounded conductors.
- Base Can – In-ground metal enclosure that supports a lighting fixture, houses its electrical components, and facilitates future maintenance.
- Beacon – Installed at an airport or aeronautical facility to indicate location and facility type to aircraft pilots at night. This device is mounted on top of a towering structure above other airport buildings.
- Cramp’s Helipad Approach Path Indicator – Visual aid to pilots ensuring a safe approach path. Can be installed at airports or heliports. Reinforces a 6-degree glide slope to helicopter approaches.
- Clearance Bar Lights – Three in-pavement steady-burning yellow lights installed at holding positions on taxiways.
- Controller – Device that provides power to lighting system and prevents overloads of lamps and other products.
- Compliance – Compliant products meet or exceed standards in order to be granted a specific accreditation (e.g., UL Listed, ISO 9001, FAA, ICAO).
- Current Driven – Type of circuit requiring constant amperage and variable voltage.
- Elevated Lights – Lighting fixtures installed with light source above ground level.
- Frangible Coupling – 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.
- In-Pavement/Inset Lights – Fixtures with light source flush to the ground or recessed below ground level.
- Lamps – Bulbs within airfield lights typically available as low, medium, or high intensity level.
- Land and Hold Short Lights – Row of white pulsating lights across the runway to indicate hold short position on runways to facilitate land and hold short operations (LAHSO).
- Line Voltage – The potential difference between two phases or lines, or the voltage running through an electrical circuit. In an airfield lighting system, the term line voltage is often used to describe the power feed on the utility side of the Constant Current Regulator.
- Obstruction Lights – Lights installed to alert air traffic to the presence of large structures (radio towers, smokestacks, cranes, etc.) at night.
- Precision Approach Path Indicator (PAPI) – Visual aid that provides guidance information to acquire and maintain a proper glideslope to a runway when landing at an airport.
- Qualified Electrician – Professional with knowledge and skills related to the operation or maintenance of electrical fixtures and associated hazards. (This definition is not specific to airfield lighting).
- Regulator – Device controlling the proper amount of electricity being sent to airfield lights to provide precision control of runway lighting circuits.
- Runway Lights – Lights outlining an airport’s runway for night and low-visibility operations.
- Runway Centerline Lighting System – System of lights embedded into the surface of the runway at intervals along the centerline of some precision instrument runways.
- Runway End Identifier Lights (REIL) – A unidirectional (facing approach direction) or omnidirectional pair of synchronized flashing lights installed at the runway threshold, one on each side.
- Runway Edge Lights – Series of white elevated lights that run the length of the runway on either side. On precision instrument runways, the amber lighting is used in the final third or 2,000 ft of runway (whichever is less in the specific instance). These systems are generally classified by intensity as low-intensity runway lights (LIRL), medium-intensity runway lights (MIRL), or 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 taxiway at the runway holding position, and elevated steady-burning red lights on each side for low visibility conditions. A controlled stop bar is operated by ATC in conjunction with the taxiway centerline lead-on lights which extend from the stop bar toward the runway.
- Taxiway Edge Lights – Series of blue elevated lights outlining the edge of a taxiway during periods of darkness or restricted visibility conditions.
- Taxiway Lights – Varying lighting fixtures that may be installed in–pavement or elevated on a taxiway.
- Taxiway Centerline Lights – Steady burning inset lights located along the taxiway centerline.
- Taxiway Centerline Lead-Off/On Lights – Series of alternating green and yellow lights embedded into the runway pavement installed along lead-off or lead-on markings.
- Touchdown Zone Lights – Row of three white light bars at intervals on either side of the centerline for the length of the touchdown zone.
- Voltage – Difference in electric potential between two points, relevant for rating lights. Different lighting fixtures require varying amounts of voltage.
- Voltage Driven – Constant voltage and variable amperage.
- Wind Cone, Lighted – Lighted wind cones indicate wind direction and speed. They are lighted for all-hours usability.