Adequate runway lighting is imperative for ensuring safe night time vision for pilots. Airport Middle East investigates the latest products on the market.
Set to revolutionise runway lighting, light emitting diode (LED) systems are designed to increase safety and efficiency. Swedish manufacturing company, Safegate, has introduced SafeLED IQ, a centrally controlled application for use on airfields.
According to Laurent Lacledere, the company's managing director, the LED technology requires less maintenance than other lighting systems.
"We are seeing more lights using LEDs because they have lower conception, they are run on lower wattage. Technology works the lights and therefore there is less manual maintenance required."
Unlike conventional lighting, the SafeLED system can be installed in one fitting.
"Instead of getting one light, where you need a converter and addressable system, this technology comes in one simple fitting," explains Lacledere. The eight-inch diameter, prism-shaped application has a valve for water tightness testing, low power consumption and more than 50,000 hours worth of light. Overall the efficiency of the LED system reduces costs for airports, particularly when it comes to renovations, which can be pricey with the halogen light technology that is often used in runway lighting. "Halogen lights are also very consuming," says Lacledere.
"If you compare the two you'll find halogen uses 45 watts while LEDs use 15 watts. Also halogen lamps last for only about 1000 hours," he adds.
Representatives from the European Organisation for the Safety of Air Navigation, Eurocontrol, argue there are two main safety issues on runways; incursions and lighting.
There is, on average, at least one incursion per airport each year, whether or not this causes a serious or fatal accident is largely down to luck.
According to the International Civil Aviation Authority (ICAO) it is forbidden to have two adjacent lights in the visibility guidelines, CAT II and CAT III. "It's down to maintenance to check this," says Lacledere.
"This can be quite time consuming so you can get information directly sent to the screen at the airport control tower in the substation." Adequate runway lighting is essential to enable the safe landing of night flights.
The SafeLED enables dynamic lighting, which means lights can be switched off when unnecessary. "For instance if you are landing from one side, the other side of the airfield does not need to be lit," explains Lacledere.
In addition the company offers a taxi routing system called Ã¢â‚¬Ëœfollow the green', whereby segments are illuminated in front of the pilot to guide him safely across the runway. "It will be used to speed up aircraft movement from the runway to the apron so you'll have fewer queues and no waiting times.
The dynamic lighting provided by LED systems can provide a better flow of traffic with the aircraft," he adds. Moreover, reports show that dynamic lighting can reduce pollution caused by aircraft in holding areas by 25%.
And as traffic and runway waiting times increase, the cause of pollution will become a more pressing problem the industry needs to tackle.
Carmanah, a subsidiary of GE Solar, sells solar-powered LED lights. These lamps, which according to management are the most advanced technology on the market, are completely self-contained and built to operate in harsh environments.
The wireless A704-5 model charges during the day, even in cloudy conditions. These high powered lights have an operating life of up to 100,000 hours and can be configured to turn off automatically at night or on demand.
The A601 model is commonly used for all types of taxiway, obstruction heli-pad perimeter and general airfield lighting. This cost effective equipment requires no maintenance for up to five years at a time.
Aura Light has been producing long life fluorescent lamps for runway signs since 1980. The 26mm lights have a lifetime of between 70,000 hours based on 3 hour switch cycle to 84,000 hours on a single switch. Nathan Peek, divisional manager of construction, power, water and lighting, says: "We offer airports a virtually maintenance free lighting solution within their directional signs located on the runway using our long life fluorescents."
The company has received positive feedback from representatives at Dubai International Airport, where the technology has been installed. "The airport will save money and operational costs due to making fewer replacements," Peek points out. "Fewer replacements will also reduce the workforce going onto the runway increasing the safety effect and, because waste is reduced, it will also be good for the environment."
Metalite Aviation Lighting
Metalite Aviation Lighting, specialises in temporary battery powered airfield lighting. Rob White, technical sales manager, and Brian Hunt, business unit manager, discuss halogen versus LED.
What products do you offer?
White: We do battery powered portable lighting used for emergencies, marking temporary lines on runways, during maintenance work or for the avoidance of obstacles. If a system failed, an airport might deploy our lights so they could make a runway, or if they are doing maintenance work they might use them. We basically offer portable, temporary lights. We offer both LED and halogen lighting.
Hunt: Nobody wants their air landing strip to be inoperable because they've lost their lighting system. This system is not just used at larger civil airfields it's also used by smaller airfields where it is the only system because they don't have the money for infrastructure.
Third world countries, developing countries, humanitarian organisations will all use this system to provide a landing capability after dark.
How does halogen and LED lighting compare?
Hunt: Halogen lighting has a long pedigree and the system we're offering is compliant with ICAO requirements. Essentially LED will give you a longer life; if you're working from a battery you'll get more hours from an LED light but not necessarily as good a light output.
On the other hand the halogen gives you a strong light over a shorter period, of 15 to 20 hours. On paper the failures of halogen lights are less than that of LED but in reality you're talking abut changing a bulb. However with LEDs when you get a failure it's usually quite intrusive. People like LED because it's the new flavour of the month.
It does offer some advantages, namely high reliability and a much longer running time. There is an argument to say they're more environmentally friendly but at the same time it depends on the scale of the use. For a permanent airfield lighting system you're probably talking about thousands of lights and on that scale it's probably true to say there would be some environmental advantages to using LED.
However if you're using more LEDs you can use more power so I'd say there would be a lot of debate over whether they actually are more environmentally friendly.
How safe is the halogen lighting system?
White: Our lights are quite small. It's easily changeable within two to three minutes. Lights generally fail when you switch them on rather than during use, so airport workers tend to know in advance if bulbs need changing. They get an audio signal to say it's not working properly and they can then bring in the temporary lighting system.
You'd actually need to have a fairly catastrophic failure of a number of bulbs before you had a safety issue for aeroplanes coming in to land. If lots of bulbs go, airports have back up systems in place to deal with these problems. Our system is designed to fill in the gap when there is failure of the main system.