Building better aircraft cabin lighting by mimicking the human eye

Creating a great in-flight experience for air travelers combines a number of elements, from the cabin crew to the seating to the Wi-Fi. But there’s one aspect of the airplane cabin that has a huge impact on your flight experience even though you might never consciously perceive it: lighting.

Our eyes are extremely sensitive to light, registering even minute differences in color. We might not notice these variations, but they have a direct impact on our mood and comfort. With this in mind, SCHOTT and Lufthansa Technik partnered to produce a new cabin lighting solution that’s more pleasing to the eye and is better for airlines too.

This new light technology, called HelioJet SpectrumCC, lifted off on Tuesday for its inaugural flight — aboard a Scandinavian Airlines System (SAS) A330 named Erik Viking from Copenhagen to Newark, N.J. — and with it, introduced a new era of lighting.

Improving airplane cabin lighting

Cabin lighting doesn’t just determine passenger comfort, but defines a brand as well. The use of color offers millions of possibilities for mood lighting and sunrise and sundown lighting effects, for example. All too often, though, the colored LEDs that can best distinguish an airline fall short. Red, green, and blue LEDs simply offer less stable color performance than white LEDs. You’ll see streaking and other variations in color, especially as the lighting fixtures age.

HelioJet SpectrumCC uses sensors to ensure that every LED in the system is perfectly in tune with the specified setup and produces the desired color temperature extremely accurately. Able to produce more than 16 million different color shades, the technology positions four LEDs – red, green, blue, and white – at either end of an optical light guide 1 yard in length. The individual primary LED colors are mixed into the desired color shade inside the light guide and then monitored and controlled to produce a more homogenous color than conventional LED strips.

How to mimic the perception of the human eye

The key to HelioJet SpectrumCC is the color control system. Because the human eye is capable of perceiving even small deviations in color, any lighting system has to match that precision to achieve its desired effect day after day.

In HelioJet SpectrumCC, True Color Sensors are installed right next to the LEDs to perform this task. The core of each sensor consists of small facets that imitate the human eye’s perception of colors by using a dichroic coating. The sensor and control technology measures the respective color shade, comparing it to the target values, and keeps it tuned as needed for an even color.

Lighting for the long haul

This airline lighting technology took off for the first time on Tuesday with SAS, but it’ll shine on for years. HelioJet SpectrumCC LEDs have a lifespan of at least 50,000 hours (mean time between failures), and individual LEDs are easily replaced when needed.

Traditional LEDs age at different speeds, due in part to temperature stresses inside narrow airplane compartments, creating streaks and other deviations in color as time goes on. When each LED is measured and controlled, however, it’s able to produce a constant color impression over the long term.

To the human eye, these more homogeneous colors make all the difference, and for airlines like SAS, these new technologies create an unparalleled in-flight experience.

About the partnership: SCHOTT developed the technology behind HelioJet, and Lufthansa Technik markets this product together with its complete lighting system for the cabin, offering its customers one-stop shopping, consisting of certification, installation, and maintenance.

February 19, 2015


Brigitte Sterf
Lighting & Imaging
SCHOTT North America, Inc.