The airfield lighting sector faces unprecedented customer demands; now LED technology and solar power look ever more like attractive options.
Airports around the world are converting to airfield lighting systems with light-emitting diode (LED) fixtures, seemingly because LED technology has further evolved since it was first introduced for taxiway and obstacle ground lighting about a decade ago.
Conditions at airports are a tough challenge for light fixtures and lamps. Systems have to be capable of withstanding greatly fluctuating temperatures and vibrations and adhere to precisely defined colour spectra and light distribution levels at the same time.
“We have seen several benefits after converting to LED lights,” confirms Iraj Ghaemi, director of facilities development for the San Diego County Regional Airport Authority in reference to the conversion to LED at San Diego International Airport (SDIA). “The LED lights have a better visual presentation; they are much brighter and sharper, and the runway guard lights really pop visually,” he says.
SDIA replaced more than 900 incandescent fixtures and signs with LED products from ADB Airfield Solutions. “So far the LEDs have been extremely reliable-the system has been essentially maintenance free for the first year of operation,” says Ghaemi and he added that energy usage had been reduced considerably.
ADB Airfield Solutions launched LED lighting on the market in 2002. Emmanuelle Luque, marketing and communications officer at ADB says that the installation of LED airfield signs and taxiway edge lights at San Diego increases safety at the airport by providing a uniform appearance throughout the airfield. “The newly installed LED runway guard light system at every taxiway hold position provides increased pilot awareness in the vitally important effort to reduce runway incursions. Their purpose is to warn the pilots of the presence of an active runway, especially in conditions of reduced visibility.”
ADB has taken LED innovation a step further by developing its new series of Elevated Runway Edge Lights (EREL / ERES). The new products are fully compatible with existing runway circuits, and they can easily replace current elevated halogen lighting fixtures since they are designed to fit on the same supports.
The technology consists of an elevated bidirectional LED light fixture which includes an Omni-directional beam component for circling guidance- as required by FAA and ICAO specifications. With a power consumption of only 33W instead of 150W for a traditional elevated halogen runway edge light, LED lighting dramatically reduces the total energy costs, which, in turn, minimises the airport’s ecological footprint.
On top of enhanced cost-efficiency, LED technology also increases airport safety. Tests have shown that the visibility of LED lighting in bad weather conditions is superior to halogen. Pilots receive more accurate visual information, both on the approach path and on the runway. The new elevated LED runway edge lighting solution is available with a synthetic or a glass lens. LED emission directly ensures the correct coloured filters to ensure daytime recognition. The embedded electronics of the EREL / ERES also makes the light output variable like a traditional halogen lamp.
In 2010 Punta Cana International Airport in the Dominican Republic began a project that included the installation of more than 450 LED signs, LED wind cones and LED runway/taxiway lights. The only incandescent fixtures on the runway are the edge lights
The $1.6m project also included an Airport Lighting and Monitoring System (ALCMS) installation. The new system now allows Punta Cana to have full distributed control of the approach and runway lights for its new Cat I runway as well as lighting for the new taxiway segments.
Control and understanding the nature of airfield lighting, especially in comparison to aircraft strobe lights is vital, if not the consequences can lead to disaster. In February 1991 USAir flight 1493, a 737 collided with a SkyWest twin-engine turboprop upon landing at Los Angeles International Airport (LAX).
The National Transportation Investigation Board (NTSB) found that the controller had lost situational awareness of the airfield and the cockpit crew of the landing USAir 737 could not see the commuter plane on the runway, which blended in with other airport lights as it waited for take-off clearance. Upon landing, the 737 collided with the twin-engine turboprop, continued down the runway with the smaller aircraft crushed beneath and caught fire.
Today’s technologies have gone a long way in helping airports to enhance airfield ground safety and efficiency, such as the recent development of field sensors by ABD Airfield Solutions. The sensors monitor the exact position of aircraft and vehicles at dedicated locations on the airside. The new solution, according to ADB, contributes to ground traffic safety at small and large airports.
At San Diego International the airport authority chose a Mobile Airfield Light Monitoring System (MALMS) unit to assist with the monitoring of lights throughout the airfield. Iraj Ghaemi explains that a new computer system provides control of airfield lighting via a touch screen in the control tower. “The MALMS allows for accurate mobile photometric measurement and management of aeronautical ground lighting (AGL) systems. The MALMS enables San Diego International Airport to effectively and efficiently maintain its AGL systems and demonstrate that the systems are in compliance with FAA airfield lighting standards.”
Up until recently, LED technology was restricted to taxiway and obstacle lighting but due to advances in the application of LEDs, they can now be found on runways. ADB Airfield Solutions claims to be the first manufacturer to introduce LED lighting on runways. The company has unveiled a new range of inset lights – known as the AD-Light range – to its portfolio. They include runway centreline and touchdown zone lights and taxiway centreline and stop bar lights.
“When we started with the concept of the new AD-Light range, it was our ambition to not only bring our existing LED technology to the runway, but also to come up with a range of innovative products that expands the well-known advantages of this technology even further. The introduction of this type of lighting on the runways is a major step toward perfectly meeting our clients’ requirements,” said Bruno Urbaing, ADB product manager for inset lights.
Airports that have expressed interest in the AD-Light solution include Paris Charles de Gaulle for installation as takeoff hold lights on the runway. The lights will signal pilots if the runway is safe for takeoff irrespective of visibility conditions.
It takes a considerable amount of energy to keep taxiways lit and operational through the night especially the long winter nights; however one Louisiana airport in America has resorted to storing the sun’s energy for nighttime use.
A solar test programme went live at False River Regional Airport in 2010. It’s an all solar-powered airfield taxiway circuit using LED lighting and a solar energy management system. Perhaps not surprisingly, ADB was on site to provide its LED products along with solar energy specialist Carmanah Technologies. Is solar powered airfield lighting a viable option?
“We did an installation at False River Airport in Louisiana to test the concept and to have an installation for demo purposes,” says ADB’s Emmanuelle Luque. “As we suspected the interest in the US is low, due to the fact that airport investments are linked to FAA funding, and the FAA is only funding lighting that meets specific specifications. The interest outside the US is mainly in South America but there are no takers yet.” At the time of this writing Luque said representatives from South America were due to make a site visit to False River Airport to see the system.
According to data from ADB the False River system is capable of running for 3.5 days at full load with batteries charged by the sun using a single large solar panel to run 164 LED taxiway edge lights. The old system used a 15Kw Constant Current Regulator (CCR) and 164 45-watt lamps and required more than 7400 watts of power every day compared to the new system, which requires 742 watts.
The change to new technology at False River has resulted in a cost saving of 90 percent before the solar portion of the project was implemented. The addition of solar has made the taxiway circuit completely autonomous since “no grid power is used.”
Despite the relative success of the project at False River, a spokesman at the Louisiana Department of Transportation and Development said that there was a triple redundancy plan in place. The taxiway circuit uses solar as its primary power, but the system can automatically change to traditional electrical power if necessary and there is also a diesel generator as backup. “We haven’t had a system failure since the solar-powered Advanced Power Supply (APS) system was put in service in May 2010,” the spokesman said.
He further said: “The LED taxiway lights receive modulated DC current from the APS that provides the desired light intensity. The APS is powered by an AC inverter, which receives DC current from a solar-charged battery bank. The LEDs require so little energy; the lamps don’t need 30-/45-watt isolation transformers at every fixture to regulate the amount of power coming into the unit.”
Experts predict that smaller airports will quickly embrace the new technology, as well as airports in emerging regions such as the Caribbean and South America where there is high interest in solar. Further predictions are that airports will eventually look to solar-driven LED lighting to power signs and obstruction lights.
