What is a complete fixture?
The finished unit as it stands on the airfield: a sealed light head, the mounting that fixes it to its base can, and the lead that connects it to power. The next entries take it apart.
On the airfield a light is one object you can point at. A complete fixture is that finished object, ready to be switched on, before anyone asks what is inside it.
1It is a head, a mounting and a lead
The light head is the sealed housing with its lens, optics, light source, driver and wiring. The mounting is the base plate and flange that fix it to the base can. The secondary lead and connector take power from the isolation transformer, which is a separate item.
2It comes in two forms
An elevated fixture stands above the surface on a frangible coupling that breaks away if an aircraft or vehicle strikes it. An inset fixture sits flush with the pavement and is built to be driven over. See elevated versus inset for how the two compare.
3Check the whole before the parts
From outside, look for a dirty or damaged lens, cracks, corrosion, loose or missing fasteners, a bent or broken coupling, a displaced fixture and a damaged lead, and check the light is on and even. Only then open the fixture, with the circuit isolated and the site’s safety procedure followed. The exploded view shows what you will find inside.
| Element | Detail |
|---|---|
| Complete fixture | The assembled unit: light head, mounting and secondary lead |
| Light head | Lens, optics, light source, driver and wiring inside a sealed housing |
| Mounting | Base plate and flange to the base can; frangible coupling on elevated products |
| Connection | Secondary lead and connector to the isolation transformer, a separate item |
| Elevated | Stands above the surface; breaks away at the coupling if struck |
| Inset | Flush with the pavement; built for wheel loads |
| To see inside | Open the Exploded view entry for the parts and their order |
Frequently Asked Questions
Q1What is a complete airfield light fixture?
The finished, assembled unit as it stands on the airfield: a sealed light head (lens, optics, light source, driver and wiring in a housing), the mounting that fixes it to the base can, and the secondary lead that connects it to the isolation transformer.
Q2What is the difference between an elevated and an inset fixture?
An elevated fixture stands above the surface on a frangible coupling that breaks away if struck. An inset fixture sits flush with the pavement in a base can and is built to take wheel loads. Which one is used depends on the location and the applicable standard.
Q3Is the isolation transformer part of the fixture?
Not usually. The transformer is a separate item, normally in the base can or a nearby pit. The fixture connects to it through the secondary lead and connector. Some products integrate the electronics differently, so follow the manufacturer's drawing.
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