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Oz Privateer
21st Sep 2007, 10:16
Any commercial pilots out there who could shed some light :O on the relative Pros and Cons of "traditional", HID (as to be used on the A380) and LED landing, taxi and take off lights. Interested included illumination and reliability...

Could you also indicate whether you fly Airbus or Boeing?

Thanks,

Oz

Rainboe
21st Sep 2007, 10:27
Look I'm in Portsmouth as well. Would you like me to come around and show you what the different Forums are first? And I fly Boeings. Lighting is a specialist subject, and it takes enough just to learn where the lights are and how they work, the practicalities of different beams is more of a specialist lighting/engineering area.

cwatters
21st Sep 2007, 10:34
I'm an electronics engineer not a pilot but... could you provide a reference/url to data on LED landing lights?

edit: Ah I see your user name implies you are a private pilot not in engineering. I asked about data because I suspect LED's aren't bright enough yet to be used for landing lights. They aren't really bright enough to be used for household illumination yet although prototypes exist.

Return to base
21st Sep 2007, 12:22
I know of at least one new aircraft in development where the requirement is for an LED landing light system including NVG capability and the lighting manufacturers were responding in a positive way so the technology is there.
If you wish to know more about what is available for aviation use, two vendors to contact are Hella and Emteq. I have found both to be very helpful
http://www.goodrich-lighting.com/
http://www.emteq.com/


rtb

aviate1138
22nd Sep 2007, 07:21
Latest Lexus LS 600H has LED headlights.
http://en.autos.sympatico.msn.ca/GreenCentre/article.aspx?cp-documentid=4742853

Plenty of LED replacement household lights already on the market.

http://store.sundancesolar.com/120voacledre.html

Intruder
22nd Sep 2007, 08:46
The only HID landing light I've seen is a "Boom Beam" for general aviation airplanes. It reputedly lasts much longer than incandescent lights in high-vibration settings, and has a higher output. Downside is cost.
http://www.speedmods.com/Boom_Beam/boom_beam_systems.htm

cwatters
22nd Sep 2007, 19:43
> Plenty of LED replacement household lights already on the market.
>
>http://store.sundancesolar.com/120voacledre.html
I'm aware of that but the amount of light they produce doesn't compare with conventional bulbs. For example a 60W filament lamp produces 600-700 Lumens. The brightest LED lamp on the above site (72 LEDs) produces only 200 lumens - so it's comparable to a 20W filament. Worse it achieves that light output over a narrow beam angle. As far as I am aware there isn't yet an LED replacement to the 50W halogen downlight people use in kitchens...but it may not be long coming.

In the UK an "energy efficient" lamp is classed as one that produces more than 40 Lumens of light per watt of electrical power. As far as I can tell you can't yet buy an LED "replacement bulb" that achieves that figure (Some CFL fail to meet that as well). Prototype LEDs have exceeded 70 L/W but really bright commercially available LEDs come as a die on a small substrate. That's because they need a heatsink. That limits there application to custom light fittings eg car headlamps.

Hopefully it won't be long before LEDs are bright enough for serious use but they aren't quite there yet in my opinion. Meanwhile I'm using light fittings fitted with "warm" tubes. These are much nicer than standard colour temperature tubes.

cwatters
22nd Sep 2007, 19:53
>Latest Lexus LS 600H has LED headlights.
>
>http://en.autos.sympatico.msn.ca/Gre...mentid=4742853

Reading between the lines I suspect that LEDs are only used for the standard low beam setting. eg not high beam. Still it's quite an achievment. This would appear to be confirmed here...

http://www.worldcarfans.com/2050418.005/hella-led-headlamp-study

"Already, the LED headlamp prototype achieves a level of around 1,000 lumens luminous flux in the low beam, and has thus reached the level of a xenon headlamp. The luminous flux necessary for good high beam light cannot yet be attained on account of the lower luminance of LEDs. Hella's lighting specialists are convinced, however, that this will soon be achieved in the course of the further development of LEDs. The technical challenges that need to be solved by then involve thermal management in particular, as well as the development of new production processes and optical elements to accompany the LED technology."