Saudi Aviation Infrastructure Glossary: A to Z Terms Buyers Need

Aviation infrastructure projects in Saudi Arabia run on a dense vocabulary of acronyms and regulatory terms, and a buyer who does not speak it loses time in every meeting. This glossary collects the terms that come up most often across helipad, airfield lighting and airside maintenance projects, from the aeronautical study that starts a heliport file to the arresting system spares that support a military runway. Terms are ordered alphabetically for quick lookup.

Aerodrome. A defined area on land or water, including buildings and equipment, intended for aircraft arrival, departure and surface movement. Airports, airfields and heliports all fall under this broader term in ICAO usage.

Aeronautical Study. A technical assessment of whether a proposed helipad or airfield layout can be operated safely, covering approach and departure paths, obstacles, wind and elevation. It is the step that should happen before detailed design, not after.

AGL (Airfield Ground Lighting). The full family of lights installed on an airfield or heliport to guide pilots during approach, landing, taxi and takeoff. It includes runway edge lights, taxiway lights, approach lights and heliport lighting as one system.

ALCMS (Airfield Lighting Control and Monitoring System). The control platform that switches AGL circuits on and off, sets the brightness step, and reports circuit status and regulator faults back to a control room or tower. Fault detection down to an individual fixture requires ILCMS equipment on the same circuits.

AOG (Aircraft on Ground). A status flag meaning an aircraft cannot fly because a required part or repair is missing, making it the highest priority category in spares sourcing and MRO logistics.

Apron. The paved area of an airfield used for parking, loading, refuelling and ground servicing of aircraft, distinct from the runway and taxiway used for movement.

Arresting System. Equipment, cable or net based, installed at a runway to stop an aircraft that cannot brake to a stop within the available distance, common at military air bases.

CCR (Constant Current Regulator). The electrical unit that supplies a steady current to a series circuit of airfield lights, allowing brightness to be stepped up or down uniformly across the whole circuit.

Elevated Light. An AGL fixture mounted above the pavement surface on a frangible base, as opposed to a flush-mounted inset light, chosen where elevation improves visibility and ground clearance allows it.

FATO (Final Approach and Take-Off Area). The defined area over which a helicopter completes the final phase of its approach to a hover or landing, and begins the initial phase of takeoff, surrounding or coincident with the TLOF.

Frangibility. A design property of airfield structures and light fittings, meaning the item breaks, distorts or yields on impact rather than staying rigid, to reduce damage if an aircraft strikes it.

Friction Coefficient. A measured value describing how much grip a runway or apron surface offers, used to judge whether a pavement needs grooving, resurfacing or a change in maintenance regime.

GACAR (General Authority of Civil Aviation Regulations). The regulatory framework issued by Saudi Arabia's General Authority of Civil Aviation, with Part 138 covering heliports and Part 139 covering aerodromes.

GSE (Ground Support Equipment). Vehicles and equipment used to service an aircraft on the ground, including tow tractors, ground power units, air start units and de-icing equipment.

Heliport. An aerodrome, or a defined area on a structure, intended wholly or partly for helicopter arrival, departure and surface movement, distinct from a runway-based airport. HAPI (Helicopter Approach Path Indicator). The visual approach slope indicator specified for heliports in ICAO Annex 14 Volume II. A single unit shows a pilot whether the aircraft is above, slightly below, on, or below the correct approach angle, doing for helicopters what PAPI does for fixed-wing runways. Annex 14 Volume II also permits APAPI and PAPI at heliports.

ICAO Annex 14. The International Civil Aviation Organization standard covering aerodrome design and operations in Volume I, and heliport design in Volume II, forming the technical basis most national regulations build on.

ILCMS (Individual Lamp Control and Monitoring System). A monitoring layer that reports the status of each individual light fixture, rather than the circuit as a whole, giving maintenance teams fault detection down to a single unit.

Inset Light. An AGL fixture mounted flush with the pavement surface, used where surface projections cannot be tolerated, such as runway centreline and touchdown zone lighting.

MRO (Maintenance, Repair and Overhaul). The industry term for the full cycle of keeping aircraft, engines and components airworthy, spanning scheduled maintenance, repair of defects and full overhaul.

NOTAM. A notice distributed by telecommunication about the establishment, condition or change of any aeronautical facility, service, procedure or hazard, essential to anyone involved in flight operations. Historically expanded as Notice to Airmen; the FAA now uses Notice to Air Missions. Commonly issued when airfield lighting or a runway is out of service.

Obstruction Light. A light fitted to a structure, crane, mast or building near an aerodrome to mark it as a hazard to aircraft, categorised by intensity (low, medium or high) depending on the height and location of the obstacle.

OLS (Obstacle Limitation Surfaces). A set of imaginary surfaces around an aerodrome or heliport defining the airspace that must stay free of obstacles to keep approach and departure paths safe.

PAPI (Precision Approach Path Indicator). A row of lights beside a runway that shows a pilot the correct glide path on approach through a colour pattern, the fixed-wing counterpart to a heliport's HAPI.

Perimeter Lighting. Lighting installed around the boundary of a heliport touchdown and lift-off area, marking its extent for a pilot during approach and hover.

Photometric Standard. A specification defining the light intensity, beam spread and colour a fixture must achieve to be accepted for aeronautical use, referenced in ICAO Annex 14 and equivalent national standards.

Retroreflective Marking. Surface marking, such as runway or TLOF markings, treated to reflect light back toward its source, keeping the marking visible under aircraft landing lights at night.

Runway. A defined rectangular area on an aerodrome prepared for the landing and takeoff of fixed-wing aircraft, distinct from the apron and taxiway.

Series Circuit. The standard electrical configuration for airfield lighting, in which fixtures are wired in a single loop supplied by a constant current regulator, so every light in the circuit carries the same current.

Taxiway. A defined path on an airfield connecting runways, aprons and other aerodrome facilities, used for aircraft movement on the ground rather than takeoff or landing.

Threshold Lighting. Lights marking the beginning of the usable landing area of a runway, typically shown in green to distinguish the threshold from the runway edge lighting beyond it.

TLOF (Touchdown and Lift-Off Area). The load-bearing surface on which a helicopter actually touches down or lifts off, sized and marked to the helicopter type the heliport is designed to serve.

Vertiport. An emerging term for a landing site designed for electric or hybrid vertical takeoff and landing aircraft, building on heliport design principles with additional provisions for charging infrastructure.

Wind Indicator. A windsock or equivalent device installed at an aerodrome or heliport to show wind direction and approximate speed to a pilot on approach.

NLS supplies and installs airfield and obstruction lighting, heliport TLOF and FATO systems, and arresting system spares across Saudi Arabia, engineered to ICAO Annex 14 and GACAR standards.

FAQ

Q: What is the difference between TLOF and FATO at a heliport? A: The TLOF is the specific surface a helicopter touches down on or lifts off from. The FATO is the larger area around it over which the final approach and initial climb take place. A heliport design defines both separately, and their dimensions relate to the helicopter type the site is built to accommodate.

Q: What does GACAR stand for and what does it cover? A: GACAR stands for General Authority of Civil Aviation Regulations, the regulatory framework issued by Saudi Arabia's civil aviation authority. Part 138 covers heliport design, construction and operation, while Part 139 covers aerodrome certification, and both draw on ICAO Annex 14 as their technical basis.

Q: Why does obstruction lighting come in different intensity categories? A: Intensity category is matched to the height of the structure and its visibility risk to aircraft. A taller structure or one closer to an approach path generally needs a higher intensity light than a short structure in open terrain, so the category is a safety judgment, not a fixed rule tied to height alone.