a technical evaluation of emteq’s tir optic technology a par64 package, leaving older technology...
TRANSCRIPT
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