What is available in today's business aircraft cabin lighting market, and why is your choice important? Trevor West spotlights cabin LED systems, asking MROs to illuminate customers on the expanding aftermarket lighting options...
Like other fields of aviation, cabin illumination has undergone a digital transformation over the past dozen years as solid-state LED (light-emitting diode) technology with circuit boards, computer chips and lighting strips has replaced incandescent and fluorescent bulbs.
The benefits of LED lighting are widely recognized: They create a much more comfortable cabin ambiance than fluorescent lighting and are far less prone to equipment problems and bulb burnout, lasting some 15 to 20 times longer among other advantages.
Additionally, “When you do a big interior update, nothing sets it off like new LED lighting,” says Duncan Aviation’s avionics installation sales representative Justin Vena.
“The lighting in the aircraft actually affects your mental state and your stress level,” explains Elliott Aviation’s vice president, avionics programs and operational logistics Mark Wilken.
“It’s proven: the light coming through the eyes in different colors affects the way you feel.”
The downside? LED lighting is relatively expensive, and without a lot of aftermarket options to offer. Therefore, such upgrades haven’t been on most owners’ and operators’ radars come modification time.
That’s changing, according to the MROs we spoke with, helping to lead an expanding LED aftermarket. The Number 1 rule of any lighting upgrade, they say, is defining the mission.
The Well-Lit Cabin of the Embraer Phenom 300
What’s Driving Your Lighting Upgrade?
“The first thing I ask is, ‘What’s your motivation behind the LED installation?” Vena reveals. “Is it because your existing fluorescent system is expensive to maintain or obsolete?
“Or do you want to better the lighting because you’re redoing the soft goods or cabin walls and you want to give it more pop?” The answer will help define the solution.
Obsolescence and economics are the most frequent drivers, as replacement parts for fluorescent systems get pricier and harder to find. Some first-generation LED lighting systems are themselves no longer factory supported.
“I’ve had three projects here recently where a week from delivery we were squawking out [B/E Aerospace] 5800-series bulbs,” said Vena, referring to popular early LED lights no longer supported by the OEM – now a part of Collins Aerospace, which is itself expanding its LED cabin lighting portfolio.
Even for older systems that remain OEM-supported, it can take weeks to get replacement bulbs. Drop-in third-party LEDs are good options as replacements, particularly if time is an issue, requiring lead times of say two weeks versus eight to 12 weeks for factory lights.
Aircraft Lighting International (ALI), a primary supplier of third-party replacements, makes LED drop-in bulbs for both LED systems and fluorescent systems. ALI has LED fluorescent replacement bulbs that incorporate all the power supply and controls found in the ballasts of fluorescent lighting systems, allowing removal of the heavy and failure-capable components.
Alternatively, for quicker, less costly conversions, LED bulbs that use the existing ballast for power can be employed. The consensus among MROs is to remove the ballast in favor of a total LED system, eliminating the analog-era component/point of failure.
When time isn’t a factor, the choice between factory and third-party replacement bulbs is often personal. “Some customers want to stick with what the factory is doing,” said Vena. “Some are frustrated by the fact they have an LED bulb that’s obsolete and don’t want to buy replacements from the company that sold them the first ones.”
Lighting Concept for Cessna's Citation Hemisphere Cabin
Choosing Your LED Lighting Ambiance
LED lighting can be white-only, or RGB (red-green-blue) systems which also provide an infinite variety of colored light. Most LED installations of either white only or RGB provide simple upwash and downwash lighting. The former casts light from valences upward, the latter downward, and these provide for most onboard ambiance lighting needs.
But LED systems are also highly configurable and can provide a multitude of effects beyond upwash and downwash. As part of a recent installation, Elliott made 3D-printed cup holders with LED lighting around the base with the aircraft owner’s LED-illuminated logo at the bottom, created with laser-etched acrylic.
RGB systems combine the three primary colors to create white as well as infinite other hues.
The color, or temperature (in Kelvin), of the white light can be tuned in both white only and RGB systems, going from a warmer, orange-yellow tone in the 2,500 to 2,700 Kelvin range, through pure white at 5,500, to a cooler blueish tint at around 6,000 Kelvin, Wilken says.
The temperature of white-only LEDs can be set at the time of installation, though some allow onboard temperature adjustment.
For guidance, major MROs have lighting expertise on their interior design teams as well as tools to help customers see and compare the differences in lighting temperatures.
For onboard operation of today’s systems, touchscreen controllers with color squares can be adjusted as desired, and app-based controls allow cabin occupants to adjust lighting through their own mobile devices.
Some LED systems offer programs with presets that automatically adjust the lighting to the phase of flight or the destination.
Healthy Lighting for Passenger Comfort
This ‘healthy lighting’ trend is exemplified in the circadian-based LED Soleil Dynamic Lighting that Bombardier introduced in May for its new Global 7500. Soleil, French for sun, uses RGB lighting to help passengers onboard the world’s longest range, purpose-built business jet re-adjust their body clocks during their journeys.
Similar applications will likely be quickly adapted for the aftermarket.
Bombardier's Global 7500 Soleil Dynamic Lighting System
However, even in new LED installations, many owner/operators retain their incandescent reading and dome lights (and typically avoid any involvement with emergency lighting systems in the modification as well, to avoid certification complications).
Early LED reading lights often delivered a harsher, more concentrated light pattern than incandescent lights they sought to replace. Current LED reading lights can provide softer, yet brighter and more dispersed illumination than their incandesced counterparts. And drop-in LED replacements with adjustable temperatures are available for incandescent eyeball and reading light fixtures.
When is Best to Upgrade Your Lighting?
A major inspection, when the aircraft has the interior removed, provides an ideal opportunity for a complete LED system upgrade. But the reality is demand for lighting upgrades lags far behind that for connectivity and ADS-B installations, with cost a major factor.
“If they can cut $60,000 off the [shop] visit—which is about what these systems cost for a Mid-size Jet [installation] — that’s quite a bit off the bottom line,” Vena says.
Further complicating the sale, the options available today can make estimating upgrade costs difficult. Duncan Aviation used to make its estimates based on cabin length; so a 15-foot cabin meant 60 feet of LED lighting, covering the up-wash and downwash on each side of the cabin.
But bulb length affects the cost, and with dual- and multi-zone cabins, and forward and aft sections, “You almost need to have the installation designed” before you can provide a quote on the installation, Vena adds.
Elliott's Prizm RGB LED Cabin Lighting System
Disappointed with the LED lighting on the market to offer its customers, Elliott Aviation has introduced, under the Elliott Technologies brand, the Prizm RGB LED system for business aircraft, “from the turboprop all the way to the wide-cabin jet,” says Wilken. A built-in Wi-Fi access point allows control via a mobile device, and the system includes an easily configurable control app.
Optional features can take the system “from mild to wild,” said Wilken, yet a basic, feature-rich Prizm costs “the same basic price competitors are charging for a white-only” system, he adds.
In March Prizm received FAA PMA approval for parts manufacture and has been installed on aircraft from a King Air “up through a mid-size Citation and Hawker,” and Elliott is developing an authorized Prizm dealer/installer network, Wilken says. “Half a dozen have been installed, and another half a dozen sold,” he concludes.
More information from www.duncanaviation.aero; or www.elliottaviation.com