At night, and when the weather is foul, blue lights delineate both edges of the taxiways at Addison Airport. Spaced 75 feet apart, for Taxiway Alpha, which parallels Runway 15/33, in round numbers that works out to 200 individual lights. And then there are the taxi lanes that run perpendicular from the taxiway to the hangars.
Until work started on Taxiway Alpha, a quartz incandescent bulb in each fixture kept pilots on the straight and narrow. With a service life of 3,000 hours, maintaining this field of aeronautical bluebonnets is an ongoing task for the airport crew, said ADS Operations Manager Dave Foster. Tending them is getting a lot easier, and economical, because the Taxiway Alpha project is replacing them with LED units.
A number of the new ADB Airport Solutions L-861 LED fixtures are already at work at the south end. If they appear more visible during the day, that’s not your imagination. The lens is optimized for day and night visibility, and there isn’t often a need to replace them because the LED, which has a service life of 100,000 hours at high intensity and 180,000 hours of typical use, don’t bake them from the inside out.
With this service life, hunting down and replacing burned out lamps will occupy less of the airport maintenance staff’s time. Another benefit of the solid-state units is their durability. They are virtually impervious to knock-over damage. Self-contained and above ground, they are not subject to water and are designed to withstand a 300 mph breeze (like a jet blast).
Power does not run down the taxi lanes, said Foster, but LED edge lighting is identifying their margins. The LightMark T2 Solar Patch is a self-contained reflective unit with four LEDs powered by a solar-charged capacitor. It charges in 3 hours on a sunny day and 8 hours when it’s cloudy or raining, and a full charge keeps the blue LEDs, visible for 3,300 feet, shining for 14 hours.
Accompanying the new LED taxiway lights are improvements to the electrical vault that controls all of the lights at Addison Airport. The new regulators will reduce power consumption (and the airport’s electric bill) and increase their reliability, which the FAA measures by the mean time between failures. Combined, it’s all part of the airport’s ongoing efforts to efficiently and economically serve its tenants and visitors.