Avionics - April 2010

Lighting
Now that light-emitting diode (LED) technology has proven its value
for aircraft lighting applications, second-generation LEDs are
being introduced in areas once dominated by incandescent lighting

By Barry Rosenberg

With the first generation of light-emitting diode (LED) technology prov- ing its value on the flight deck and in the cabin, manufacturers of aircraft lighting systems are developing second-generation systems that throw off more light while using less power, have longer life and take full advantage of lighting technology developed for commercial electronics.

LED lighting continues to make inroads across all areas of aircraft lighting, from the flight deck (with all new-production cockpits going to LEDs), to cabin interiors (for signage, reading lights, flood lights and area lighting), to the aircraft exterior (wing-tip and anti-collision lighting).

Courtesy Aerospace Optics

LED modifications and upgrades are also holding up during the economic downturn in all three lighting categories, according to industry observers. For example, Ohio-based Nextant Aerospace includes LED master caution systems and LED cabin lighting as part of its Beechjet 400NEXT upgrade program (a modification of the Beechjet 400A and XP) that also features new Williams FJ44-3AP engines and Rockwell Collins Pro Line 21 flight deck.

“The major avionics OEMs are turning out to be my best salesmen,” said Bruce Maxwell, president of Luma Technologies, based in Bellevue, Wash.

“You see lots of ads and photos of shiny new or modified cockpits with one of those beautiful flat-panel systems, and what do you see? Your eye is immediately drawn to all the older switch lights and caution systems, with their failure-prone heat-generating incandescent lamps. My take on it is that if you don’t upgrade them at the same time, it’s like changing

Aerospace Optics' Logic Series, introduced in 2009, improved upon traditional incandescents by replacing the electromechanical holding coil with an electronic holding coil.

your oil and not replacing the filter; it just
doesn’t make any sense. An increasing
number of OEMs and mod centers are
coming to me asking how our LED prod-
ucts can be bundled in with their own.”
In response, companies like Luma and
Emteq, of New Berlin, Wis., are develop-
ing a growing number of systems and
supplemental type certifications (STC)
for the aircraft platforms. The goal is for
a drop-in, plug-and-play replacement
wherever possible.

Emteq recently received an STC for a white light LED cabin system to replace incandescent bulbs on the DC- 9. White has always been the most difficult color for LEDs to project because of an additional phosphor coating that is required, leading many manufacturers to use red, green and blue LEDs for accent lighting while relying on incandescents for white.

Emteq targeted the STC at the 69 DC-9s still operated by Delta Air Lines, all of which came from Northwest Airlines when the two merged. There are also

50 plus DC-9s still flying in Europe, primarily with KLM and Austrian Airlines.

“Technically speaking, the challenge
for us (in developing the STC) was get-
ting a small, reliable package for 115 volt
AC power,” said Matt Trotter, Emteq
director of LED products. “LEDs are
DC-voltage devices, so you have to take
in AC and create DC in an efficient pack-
age. We wanted to run power directly
from the harness to the lamp assembly
itself. Everything is contained within the
product so there are no separate boxes
like those that would be required with
fluorescents.”
Trotter said he believes the market for
cabin retrofits of LED lighting can only
grow larger. “When you look at the 767,
757, even the 737 and the A320 family,
these aircraft are of an age when new
interiors and seats are being considered,
so new lights make sense,” he said.