This document presents analysis of in LED exterior lighting full-fixture replacements vs.

Halogen bulb and LED bulb replacements. Advances in technology have resulted in

customization options never before possible with LEDs including: beam spread, intensity,

customizability, and IR options.

A Technical Evaluation of EMTEQ’s TIR Optic Technology

&

An Analysis of LED Full-Fixture Landing Light Replacements

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Technical Advancements in LEDs

Infrared Capabilities

Invisible to the human eye, IR light provides covert flight operations the capability to fly dark. Aircraft

landing lights, “slime” formation lights, and beacon lights provide aircraft identification to those aided

with NVG goggles. With the continued migration toward LED aircraft lighting, IR illumination begins to

benefit from this modernization of lighting technology.

EMTEQ’s PAR36 landing/hover light is the first in EMTEQ’s LED exterior lighting family to be modified to

have the capability of LED driven infrared illumination. Results have verified that high infrared output is

achievable, peaking at a wavelength of 870 nm. EMTEQ’s Dual Mode PAR36 outputs NVIS Radiant

Intensity (NRI) values of 75 watts/steradian utilizing only one of nine TIR optic units housed within the

PAR36 assembly. The remaining eight provide 170,000 cd of aviation white illumination at a ten degree

beam spread. Utilization of all nine TIR optic units provides an estimated NRI value that approaches

600 watts/steradian for a single mode IR light.

Figure 5: Off @ 200 ft Figure 6: Dual Mode IR

landing Light On @ 200 ft

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The Case Against Halogen/Incandescent Lighting Fixtures

The Intensity Barrier

The Total Internal Reflection (TIR) optic is an integral component for a light designer looking to capture

and direct illumination from a point source light like an LED. Many bulb replacement PAR36/46/64 LED

designs utilize TIR optics to collimate, intensify, and direct their illumination for taxi, hover, landing

application. EMTEQ’s use of TIR optics has resulted from 2-years of trial-and-error to achieve a

replicable design and manufacturing process that resulted in a TIR module that is able to be staged to fit

traditional PAR or airframe custom fixtures.

Total Internal Reflection focuses the light emitted to create an intense, direct output with no light

wasted outwards. A standard LED emits light upwards of 120° or more. A custom optic designed to

match a specific LED focuses all light emitted to a 10° spread. By not compromising on optic design,

EMTEQ TIR optics are able to deliver a level of intensity not currently available in the aviation market

with LEDs. TIR optics allow us to effectively collimate the LED light sources and deliver parallel light

waves that spread slowly without the use of lens polishing techniques. Full-fixture replacements with

TIR technology allow for a more intense, direct output by not crossing the light waves emitted by the

LEDs.

LEDs provide a longer lasting, more consistent intensity output than traditional Halogen or Incandescent

bulbs which can fail after as little as 10 hours of use. Legacy bulb intensity degrades rapidly as the

superheated filament breaks down (Graph 1). LED’s operate much more efficiently and produce much

less heat.

Graph 1: LED vs. Halogen Intensity Comparison

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Field-tests and light lab studies conducted at EMTEQ and with customers confirm EMTEQ’s TIR optic

meets or exceeds aviation standards for landing and taxi light illumination (reference figure 3 and 4).

EMTEQ’s customized lighting designs include the PAR36 landing and taxi that match industry standard

PAR36 landing and taxi lights in intensity and design. With this technology, we are able to achieve

intensities of more than 180,000 cd in a PAR36 package, 380,000 cd in a PAR46 package and 550,000 cd

in a PAR64 package, leaving older technology and other LED exterior lighting optics far behind.

Graph 1 shows actual test data comparing light intensity over time of a Halogen bulb and an LED. While

legacy bulbs degrade to 70% of their initial intensity after only 5 hours, a typical high power LED would

take 50,000+ hours of operation to degrade to 70% intensity. This longer life and robust design provide

significantly reduced maintenance demands.

The Case for Full-fixture Replacements

How to Achieve Intensity

During optical design and testing, characteristics in manufacturing process and mechanical dimensions

were quickly identified as necessary in order to achieve intensity targets of legacy Halogen and

Incandescent PAR bulbs. As a result, a full-fixture design was determined as the direction for EMTEQ’s

LED landing/taxi lights. This full-fixture design presents additional integration consideration as it

replaces the bulb, metal housing assembly, bracket, and power supplies associated with the landing

light. Adaptation of the full-fixture design to rotor and fixed-wing aircraft is unique to each aircraft, but

is currently being accomplished through intelligent design of a product line of mounting brackets,

connectors, and light diffusing films.

Figure 3: Incandescent PAR36 Taxi Figure 4: LED PAR36 Taxi

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Performance expectation for the full-fixture replacement at the industry’s most popular beam spreads

and uses are listed below.

EMTEQ LED PAR36 Taxi – 40,000 peak cd at center beam (40 deg total spread)

EMTEQ LED PAR36 Landing – 180,000 peak cd at center beam (10 deg total spread)

EMTEQ LED PAR46 Landing – 380,000 peak cd* at center beam (11 deg total spread)

EMTEQ LED PAR64 Landing – 550,000 peak cd* at center beam (11 deg total spread) *Estimated through real world testing and optical modeling

Beam Spread Customization

Traditional Incandescent and Halogen bulbs produce a beam spread and diffusion through a

combination of concave reflectors and Fresnel lenses. TIR optics replace this concave reflector, focusing

emitted light to a 10° spread. Applications requiring a wider beam spread than the 10° provided by the

TIR optic required the addition of a light diffusing lens. EMTEQ’s industry research identified a variety of

diffuser films that, when applied match beam patterns for dozens of taxi lights, ramp flood lights,

landing, and hover lights with limited loss in intensity. This beam spread customizability has not been

effectively accomplished by LEDs in the past.

EMTEQ’s PAR36 Taxi light delivers a wide angle beam spread and a center beam candle power of 40,000

cd, while the PAR36 Landing light delivers a narrow beam spread and a center beam candle power of

170,000 cd.

Conclusion

A number of OEM platforms have already made the switch to EMTEQ’s LED landing lights including

Learjet 85, Embraer Legacy, Embraer Lineage, Embraer E-Jets, Pilatus PC-12, and the Bombardier Global

7000s and 8000s. LED exterior lighting full-fixture replacements provide grounds for the continued

integration of LED technology into high-intensity applications. LED exterior lighting full-fixture

replacements are now a viable alternative to dated halogen fixtures. They offer the same customizable

Figure 2: Medium Beam Spread Comparison to

Halogen

Figure 1: Wide Beam Spread Comparison to

Halogen

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attributes as halogen fixtures while delivering numerous benefits above and beyond what halogen

lighting is able to offer. EMTEQ has developed the technology necessary for LEDs to deliver a lighting

solution that meets or exceeds the needs of pilots in the field. With lower maintenance and a longer

lifespan, as well as a number of other benefits that increase the performance of LED exterior lighting,

LED lights are an equitable business decision for any aircraft.

Evaluation of LED vs. Halogen Illumination

Attribute LED Halogen Weight Comparable to Halogen with full-

fixture replacement Lighter than LED if no driver/relay box is used

Input Power 75W for PAR46 450W for PAR46

Inrush Current Low. Full intensity within nanoseconds

More than 10 times operating current

Lifetime 30,000+ Hours MTBF 10 Hours

Vibration and Impact Resistance better resistance to mechanical force

Fragile filament

Surface Temperature Safe to touch Housing can exceed 200° C

Dimming Capability Equitable Equitable

Infrared Signature inherently low IR signature Inherently high IR signature

Color Rendering Equitable with selection of LEDs Equitable

Intensity Equitable and stable over life of product

Equitable when new, degrades rapidly

Voltage Regulation Constant intensity throughout operating voltage

Intensity varies with operating voltage