AGL Inset Base for In-Pavement Airfield Lighting

An inset light base is the structural interface for a compatible inset airfield lighting fixture in a pavement-integrated installation. It provides a fixture-specific mounting interface, provision for cable connection and routing, and drainage where the installation requires it, and it suits both new-build and rehabilitation projects.

Inset bases are used for selected flush-mounted or inset fixtures, including runway centreline lighting, runway threshold and runway end lighting, touchdown zone (TDZ) lighting, taxiway inset lighting and other selected inset AGL fixtures. Always match the base configuration to the specific inset fixture and the pavement construction.

Select the base according to the specific fixture installation interface. Check the fixture make and model, base dimensions, mounting-hole arrangement, fixture height and installation depth, cable-entry position, connector arrangement, drainage requirements and pavement construction. Do not select a base solely from the nominal fixture category; confirm the actual fixture model and installation configuration before procurement.

Installation is closely tied to the pavement structure and finished surface level. Consider pavement thickness, base installation depth, finished pavement elevation, fixture seating arrangement, base support and anchoring, concrete or foundation requirements, cable routing, the drainage path and access for future maintenance. Fixture seating height must stay within the protrusion limit set by the fixture specification and the aerodrome authority.

The base provides the interface for cable connection to the fixture, and routing should be coordinated with the complete AGL circuit design, including primary circuit cables, isolating transformer connections, and secondary leads and connectors. An inset circuit may connect through a nearby junction pit or cable infrastructure. Confirm entry dimensions and positions before installation to avoid interference with the fixture or pavement.

Drainage matters because the base is integrated into the pavement environment. Consider water collection around the fixture, internal base drainage, connection to an appropriate drainage path, pavement slope, sealing and ingress protection, and local groundwater and environmental conditions. Coordinate drainage with the civil and pavement design rather than treating it as an isolated fixture-base detail.

The base and its supporting installation must suit the mechanical conditions of the airfield pavement. Selection may depend on fixture loading, pavement type and thickness, base construction and foundation arrangement, vehicle or aircraft loading conditions, the installation environment and project-specific structural requirements. For new installations, incorporate the base arrangement into the approved pavement and airfield lighting design.

Verify the fixture model and mounting interface, base dimensions and installation depth, pavement construction, finished surface level, cable-entry arrangement, transformer and connector configuration, drainage provisions, structural support, alignment and orientation, and the fastener torque values from the fixture and base documentation. Use base covers or temporary plugs to keep paving material, sealant and debris out of the base until the fixture is fitted.

Useful information includes the existing fixture make and model, existing base dimensions, pavement thickness and installation depth, existing cable-entry arrangement, transformer location, junction-pit arrangement, drainage configuration, and site photographs and drawings. Where existing components are retained, confirm dimensional compatibility before ordering.

Check correct fixture seating and finished elevation, secure mounting, correct cable connections and cable protection, drainage performance, the pavement interface, alignment and orientation, and electrical continuity and circuit operation. Complete any installation-specific inspection or testing required by the project commissioning procedure.

References include FAA AC 150/5345-42K (airport light bases, transformer housings, junction boxes and accessories, including load-bearing bases for inset fixtures), FAA AC 150/5340-30J, FAA AC 150/5345-46F, ICAO Annex 14 Vol. I Chapter 5 with Doc 9157 Part 4, and DGCA India CAR Section 4 with airport specifications. The base must match the fixture manufacturer documentation, and the base type, class and size designation should be confirmed in the current edition against the fixture data.

No. An open series circuit driven by a constant-current regulator can produce dangerously high voltage, and opening, cutting or disconnecting any part of an energised circuit can cause serious injury or death. De-energise the circuit at the regulator, apply the site lock-out / tag-out procedure, use the series circuit cut-out switch or an approved isolation device, and work under the airport permit-to-work system. See the electrical safety warning on this page.