Inset (or in-pavement) lighting on runways and taxiways is critical to an airport’s overall aircraft management strategy. Unlike elevated lights, inset lights are installed flush with the pavement. This placement minimizes damage due to the movement of aircraft and maintenance equipment, which are common hazards to elevated lights.
However, their placement is also why inset lights generally require more maintenance than elevated lights. These flat, ground-level light fixtures are subject to dirt, jet fuel, de-icing fluid, and other contaminants that can collect on the lens and deteriorate the light output on both runways and taxiways.