According to Pamela Whitley of the US Federal Aviation Administration (FAA), functions include navigational aids for pilots, airfield lighting to delineate runways and taxiways, and obstruction lights for towers and transmission lines.
The FAA is currently developing new standards and specifications to accommodate LEDs, including the power supply infrastructure. LED-based blue runway edge lights and red obstruction lights are already in use at some US airports.
Green taxiway centerline lights and threshold lights are also being tested, and standards are being developed for yellow runway guard lights. Color, chromaticity and variation with time are closely controlled by FAA regulations, and airport lights must also operate in extreme weather conditions and under exposure to hazards such as snow ploughs and de-icing fluid.
