Thorn Europhane

The LED take-off in airfield lighting

As the worlds leading quality supplier of professional lighting solutions, Thorn has focused its R&D resources on the area of LED technology. LED technology has been around since the 1970’s. However, continued improvements in light output and colour rendering has led to an explosion of the applications they can be used for including the airfield lighting.

What can LED bring to Airfield lighting ?

The first benefit is the increased lifetime of the light source. Switching from a 1.500 hour halogen lamp to a 50.000 hour LED brings a lot of savings in terms of maintenance. Particularly on busy airports where the re-lamping activity is an issue. The second benefit is the lower energy consumption. Without infrastructure change, the simple switch from halogen lights to LED lights divides the power consumption by two.

The LED technology has two other characteristics that are real strengths in the airfield environment : the robustness and the compactness. Inset light fittings must bear hard shocks from aircrafts and machines like snow-ploughs that roll on it. So the fittings must incorporate shock absorbers to protect the filament of the incandescent lamp. This is not needed with LED. To illustrate the compactness of this technology, let’s consider Thorn’s new taxiway centreline LED fitting (ILD-T). This is the first 6mm depth (FAA style 3) LED fitting without counter-slope with integrated electronic module that can fit in a 100mm high shallow base.

Are there limits to the use of LED in Airfield lighting ?

The first limit is the light output. The LED are continuously improving but today they cannot achieve the photometric requirements for the runway and even less for the approach. There use is therefore limited for the moment to the obstruction and the taxiway.

There is another limit linked to the fact that the LED directly generates a coloured light. The white is difficult to obtain.

What are the development prospects of LED in Airfield lighting ?

We can distinguish 3 phases in the development of LED in Airfield lighting. The first phase is a generalization of field tests. Over the last 3 years, an increasing number of airports have experienced the integration of LED fittings in their installations in order to assess their electro-magnetic compatibility with existing equipments and circuits. The feed-backs are promising.

The second phase is the use of LED fittings as a real techno-economical alternative of halogen lights for existing installations. The ramp-up is linked to the taxiway renovation and extension projects.

There is a third phase, parallel of the second in terms of timing, but different in terms of approach. The idea is to design a dedicated electrical installation optimised for the LED. Because today’s 6.6A serial circuit standard does not allow to get all the potential benefits of LED technology. Of course, this new design is economically viable only for new installations.

With its long experience in General lighting applications and Airfield lighting systems, Thorn has developed a complete LED product offer that can be installed in serial and parallel circuits.

Contact Details
	T: +33 (0) 1 4953 6262
	F: +33 (0) 1 4953 6289
	E: thornairfield@thorn.fr
	W: www.thornairfield.com