Airfield lighting systems provide critical visual guidance for aircraft take-off, landings, approach and safe movement on the tarmac to and from gates. The light bulbs in this category have been designed for reliability, high performance, long life and low maintenance - all key requirements for maintaining airfield and runway lighting safety. These specialty airfield light bulbs have also been manufactured to withstand the effects of weather and vibration on the runway for taxiway and approach traffic.
Halogen vs. LED Airfield Lights
While many airfields have made the transition from older incandescent and halogen bulbs to LED, halogens hold advantages that LEDs do not.
Halogen airfield bulbs cost significantly less on a per-bulb basis, although they use far more energy than LEDs. They also have a much shorter rated life than LEDs, so more maintenance is required to ensure burned out bulbs are replaced in a timely manner. However, one significant advantage of halogen lamps is the high amount of heat they produce compared to LED. For airports that experience severe snowstorms, this heat output can discourage snow accumulation on the light fixtures and provide continuous visibility.
LED airfield bulbs cost signficantly more on a per-bulb basis, but their lower energy usage and longer life provide significant advantages. Bulbs have to be changed far less frequently, reducing both energy costs and maintenance costs. LEDs do not put out nearly as much heat as halogen bulbs, though, so special types must be considered for airport lighting in colder climates. Also, LED bulbs do not tolerate high temperatures, so proper thermal management needs to be considered with the fixtures and the types of LEDs used. Poor heat management can significantly reduce LED bulb life.
Airfield Lighting Maintenance Tips
The following are a few tips for any type of airfield and runway lighting system.
Do not mix and match incandescent/halogen and LED bulbs or fixtures on a taxiway or runway. This can lead to subtle but noticeable differences in brightness, color temperature, or color rendering. Small changes can make a big difference, so consistent lighting is important.
Consult as-built and shop drawings. These should also include the manufacturer of the light fixtures and replacement light bulbs. Original equipment manufacturer (OEM) equipment should be used when replacing lights, although exact equivalents can be considered when retrofitting the entire system. Consulting the manufacturer's specifications for the fixtures and bulbs should be the first resource.
Use bulbs that meet the fixture manufacturer's specifications. If newer versions of old airfield bulbs are produced, they should be backwards compatible with the manufacturer's equipment. However, using different non-equivalent bulbs that seem to meet the requirements of the fixture may not be a reliable guide, especially if moving from halogen to LED bulbs from different manufacturers.
Keep multiple spare bulbs on hand and buy in bulk. This should be elementary, but sometimes replenishing stock of runway bulbs slips through the cracks. Having several dozen or hundred spare bulbs on hand can make maintenance personnel's lives easier and reduce the risk of safety dangers due to inconsistent or poor lighting.