Lighting is becoming an increasingly important component of overall passenger experience.

Delivering the best ‘passenger experience’  is the goal of every airline. More often than not nowadays, any discussion of the topic tends to be about on board internet connectivity, inflight entertainment choices, the delivery methods for IFE, and perhaps seats and legroom.

Lighting in the cabin is often found a bit further down the list, perhaps because it is so often considered a hygiene factor – you barely notice it when it’s right, but it is irritating when done poorly. Lighting suppliers have been moving to ensure that lighting can not only be attractive and appropriate throughout the cabin, but also for the individual.

New lighting products are being launched regularly, each designed not only to bring improvements in performance and aesthetics, but also to contribute to an airline’s bottom line.

Before describing its recent products, Dirk-Achim Schevardo, manager, business development, cabin systems at Diehl Aerospace, gives some background to their genesis:

“The aim of cabin illumination is to create wellbeing onboard for the passenger. Therefore Diehl Aerospace is always in direct contact with the major OEMs and the airlines to fulfil this aim,” he confirms.

“The company performs a lot of tests on how light impacts humans and then designs new illumination with the best available technology. In the last year, Diehl updated the already flying LED unit for one of the Airbus models to the latest technology version for a better performance regarding space, weight and lighting appearance,” he adds.

“There is a trend in the market for [enabling] the operator to create an individual cabin brand. Based on this, we are working on flex-illumination and flat-surface-illumination providing even more flexibility and design possibilities. With such technologies, the mood lighting on board gets a new boost to branding, differentiation by industrial design and definitely to boost human-centric lighting (HCL),” Schevardo reports.

At Collins Aerospace, a “plug-and-play” version of its Tapestry LED full mood lighting system, has recently been introduced.

“Our system fits within existing fluorescent fixture mounting envelopes and locations, and its specially formulated LED lighting lenses fit existing sidewalls,” explains Stephan Azelart, the company’s vice president, sales and marketing, interiors evacuation, water and lighting solutions.

“This enables airlines to meet their need for a cabin lighting retrofit without a full architecture or major modification. Tapestry easily replaces conventional fluorescent cabin lighting with high colour rendering index (CRI) colour points that are calibrated for consistency and intensity. With consistent and accurate lighting, it helps airlines emphasise their brand identity.”

Luminator Aerospace’s EMEA manager, Aerospace, Lloyd Francis, says that his company has introduced two new types of LED lighting tubes over the past year. “One series acts as a direct replacement for traditional fluorescent tubes aboard existing aircraft. This retrofit series has two options. The first is Bi-Colour & Tri Colour Lights, a true Plug & Play system that requires no alteration to the aircraft structure, interior components or system wiring,” he elaborates.

“The control interface uses the same system as before, while all the existing ballast can be removed adding to weight savings. The colour options are selected by the customer and set during manufacture. Note though, that this is not an RGB mood lighting system.

“The second option is Full Mood Lighting (RGBW). The entire mood lighting system is driven by a 4.3” diagonal LCD display with integrated touchscreen and USB drive port. Owing to the intelligence of the touchscreen control panels and versatility of the colour cabin light sticks (full RGBW), the number of colours and intensities are virtually unlimited,” Francis notes.

“The configuration of the class of service, scenes and colours can be set using the Maintenance Mode of the Cabin Lighting Control Unit. Once the airline has created its custom scene and colour configuration, the lighting tables can be downloaded to a USB drive. The rest of the fleet can be programmed by uploading the lighting tables  using the USB port to the user modifiable partition of memory.

“The second series uses a new reduced size in comparison with fluorescent tubes as fitted to the CRJ and other smaller aircraft,” Francis continues. “We expect this new small architecture LED strip system to be adopted by the single-aisle airframes as the move to larger overhead bins to accommodate a greater quantity of carry on suitcases gathers momentum.”

As Burrana establishes its brand, its CEO David Withers points out that his company’s LED lighting solutions meet a wide range of airline needs. “For airlines looking to achieve cheaper cost of ownership, our like for like solution, a single colour (white) light is our entry offering and does not require a Cabin Management Terminal (CMT),” he begins.

“Our mid-range product is white plus one colour: an option of an intermix of LED and fluorescent for on-attrition upgrades. The top of the range multi-colour LED solution offers full RGB with millions of colour and intensity permutations to take advantage of all features and benefits of LED lighting, which include significant weight savings over fluorescent systems, helping to reduce the cost of ownership.”

Withers also highlights an oft-overlooked factor in lighting development, the environmental impact. “Burrana’s LED lighting solutions have an environmentally friendly focus. Our system is lead-free and follows the Restriction of Hazardous Substances (ROHS) directive,” he emphasises.

Having introduced two new reading lights at AIX 2019 – Opal and Sapphire, Schott is currently working on the next-generation model – Jade, which is scheduled to be released at AIX 2020, according to sales director Aviation & Automotive, Philip Fischer.

“Opal and Sapphire have generated very high interest on the market, through fresh designs, various customisation options and incredible small integration depth, which makes them suitable for all different kinds of seat designs,” he remarks.

“We are finding more and more interest in sophisticated lighting to further enhance the passenger experience. With our new, flexible HelioCurve (RGBW) LED strip, we can achieve both individual illumination as well as general ambient light effects,” Fischer continues.

“Through its flexibility, HelioCurve can underline curved contours and generate impressive, unique lighting effects. It is well suited for the illumination of pockets, ottomans, aisles and under armrests. Plus, it can be linked to Schott’s intelligent Multi-Light-Controller to run specific mood lighting scenarios and be synchronised with the Schott HelioJet main cabin lighting system.”

Jetlite aims to provide lighting which reduces jet lag and increases overall health and wellbeing during flights and claims to have the “first holistic and scientifically proven solution” to do so. Dr Achim Leder, the company’s co-founder and CEO, runs through some of the technology involved. The Jetlite controller, installed in the cabin, steers the cabin lighting automatically in line with human-centric lighting standards. It is operated via the existing CMS,” he states.

“The controller has been shown to reduce jet lag and thus, contributes to overall health and wellbeing of passengers. The ever increasing workload of flight attendants is mitigated as the regulation of the cabin lighting is down to a minimum of one simple click – ‘Start Jetlite’.

“Lite2Fix is a fastening cover with a customisable lighting system that digitises the cabin from manufacturer to passenger. It enables HCL during the flight and also allows passenger information, de-boarding boarding assistance or airline branding to be displayed,” Leder notes. “The Jetlite In-Seat Solution provides HCL tailored to each passenger’s needs. Every passenger is different, of course, so by considering factors like Chrono types (inner clock) and travel objectives, we deliver a lighting programme tailored to each one.”

AIM Altitude specialises in integrated lighting solutions as opposed to separate lighting ‘products’. “This is key within BFE [buyer-furnished equipment] units where space constraints and radically contoured units make lighting installation difficult,” explains Marketing Manager, Natalie Varney, adding that the company has used its knowledge to design or adapt products “to achieve the desired effect chosen by the customer.”

“The Emirates 777 Ghaf Tree feature panel is a good example of AIM Altitude providing an integrated lighting solution using existing products,” Varney says. Further examples are the Virgin A350 Social Zone “offering various scenes for different flight segments” and the Branding Panel for Oman Air “using lighting to enhance the 3D appearance of the Arabic design.”

The animated RGBW lighting panels which AIM Altitude displayed at AIX 2019 allow programmable sequences to be created, enhancing visual appeal and allowing movement into otherwise static surfaces. “AIM Altitude believes it is not just the lighting that is vital,” says Varney, “but getting the right balance with the associated materials, lenses, reflectors, and finishes to achieve the desired aesthetic, while maintaining an airworthy product.”

Getting all this lighting just right in order to provide the desired effect means working with not just airlines but also those who understand the effect of light for every time of day in passengers’ biorhythms. Learning from such collaborations is important.

“AIM Altitude has its own industrial design team that can provide mood lighting concepts to an airline, as demonstrated as part of our ULTRAFLEX Cabin,” Varney confirms. “However, many airlines choose their own design specialist who will work with our team to ensure the design intent is met in a technologically feasible way.

“With regards to biorhythms or circadian rhythms, the monuments AIM Altitude typically deals with are more concerned with zonal effects on lighting.These are to extend the specific area aesthetic, local to that monument, to the particular phase of flight,” she adds. “This could be, for example, having lighting that promotes alertness for social interaction during a play phase, different lighting for concentration during a work phase, and an optimum level and temperature for resting.”

Diehl’s Schevardo reports how the company’s LVC (Light Verification Center) has more than 1,200m2 in which a customer can experience cabin illumination, meaning that Diehl operates 1:1 mock-ups with the original lining of the respective aircraft programme.

“In the LVC, Diehl also performs lighting tests with the best available optical instruments like spectrometer, goniometer and sphere. Such engineering tests, the wishes of the operator and tests with real ‘passengers’ are going directly into our new developments of cabin illumination,” Schevardo states.

“Regarding HCL, one of our customers is already operating a fully integrated HCL system within one of its aircraft type,” he continues. “HCL is more than just a buzzword – it’s reality.”

Luminator’s mood lighting tries to work on simple principles, notes Lloyd Francis. “The retrofit or short haul Bi-Colour & Tri Colour Lights are a series of fixed colours within the LED strip/tube which can be easily selected. The ceiling and wall wash lights do not necessarily have the same colour characteristics. The contrasting wall wash colour helps reinforce this feeling of passenger wellbeing.

“Having worked with a number of airlines on different airframes, Luminator has found that there is a surprising number of installed lighting configurations, dependent upon the original customer,” he adds. “Therefore it is necessary to perform a relatively simple survey of each aircraft to determine the retrofit build spec. Regarding ROI for airlines adopting LED lighting, the time period is around eight months.”

Similar to Diehl, Collins Aerospace provides full mock-up access onsite so airline customers can experiment with the system in their native environments. “Through our tool, prospective customers can dress a cabin with seats upholstered to their branding while we provide expertise in defining the colour points that are most suitable for each phase of flight,” says Azelart.

SCHOTT’s Fischer says his company has been working on ‘right lighting and passenger biorhythms’ for many years, notably in lighting workshops with airlines as well as light designers. “We are also part of international expert working groups within the

industry to contribute actively to this discussion,” he comments. “To influence passengers’ biorhythms by the means of light, cabin lighting has to imitate nature and thus provide a wide colour gamut of more than 16 million colours. It also needs to consist of 100 per cent perfect light – that means eliminating the ‘colour effects’ of ageing of LEDs.

“We combine an optical light converter with an LED sensor which homogenises the light output of every single LED. As a result, our products produce no colour drifts or ‘light dots’. Even when new lights replace older single light units, they are automatically managed to the defined colour tone.”

The enthusiasm for what LED lights can deliver also extends to Burrana. “LEDs give the ability to manipulate settings, colours and intensity levels, enhances passenger mood and restfulness, and replicates the correct sleep and awake times,”Withers concurs.

“It allows cabin crew to deliver their service based on the time of day at the destination (for example, a restaurant feel for dinner, a café feel for breakfast) and manage daylight or night hours. LED lights also allow replication of sunrise and sunsets recorded with a custom light colour and intensity meter, specific to destinations on the airline network.”

Given the sentiments expounded by Achim Leder, it is hardly surprising to discover the lengths to which Jetlite has researched mood lighting and its effects. “Actually, Jetlite goes a step beyond mood lighting. We don’t only use light for cosy atmospheres like mood lighting does, but we support the inner clock to prevent jetlag symptoms and increase relaxation and activation,” he emphasises.

“Our Jetlite-Lighting Solutions is based on the Jetlite-Algorithm that translates scientific research in the fields of human-centric lighting and chronobiology into lighting scenarios that reduce jet lag for passengers. Considering flight parameters, such as routes, directions and time zones, the algorithm steers an aircraft’s cabin lighting in the most efficient way,” Leder confirms.

“We have done a lot of research. For example, a qualitative study with six simulated 10 hour night flights with realistic cabin conditions.”The testing covered areas such as melatonin and cortisol levels, heart rate variability and motion data and included subjective self-reports.

Looking ahead, AIM Altitude’s Varney, posits that the industry considers that LEDs will be the light source of choice for some time, so the focus is on how to provide more dynamic and granular control without significantly increasing the associated electrical circuitry. “The smaller and simpler the solution, the more applications it will have.”

Appropriately, therefore, Collins Aerospace is currently working on a series of microLED technologies, to enable extensive illumination capabilities from panelised lighting on flat and curved surfaces, with video capabilities also embedded into the system.

“We are the first aerospace company to apply μLED (microLED) technology to the cabin via a brand new μLED Reading Light,” Azelart declares. “This innovative lighting solution, builds on the company’s portfolio of μLED lighting to offer longer-life solutions with greater weight savings.”

Jetlite’s Leder agrees about LEDs leading the way, but also believes that OLEDs (organic light-emitting diodes) might become key if prices decrease and flexibility increases. “With OLEDs you can add complete new design features to an aircraft cabin,”  he remarks.

Finally, Luminator’s Francis offers a different take. His company is working to improve cabin health and safety by integrating new antibacterial lighting. “This kills various bacteria such as MRSA, E. coli, and salmonella, as well as yeasts and fungi while not using a UV light that would damage or weaken plastic or interior components through long term exposure. It will be available later in 2019,” he confirms.

Thus lighting can be a hygiene factor in more ways than one.