Cancidas From Poland, joined Jul 2003, 4112 posts, RR: 12 Reply 1, posted (9 years 4 months 2 weeks 3 days 4 hours ago) and read 1309 times:
i'm not sure what you mean. are you asking why LED lights are not used in aviation more often? actually, they are. i have seen quite a few aircraft, bit GA and airliners using LEDs for position (anti-collision) lights. the strobes, well they have to be strobes. however, the reason LEDs are not used in landing/taxi lighting is twofold. partly, it's the same reason you won't find LED lamps for your house. they just don't put out good white light. the other is that they are not bright enough for use as landing lights.
"...cannot the kingdom of salvation take me home."
Airplay From , joined Dec 1969, posts, RR: Reply 2, posted (9 years 4 months 2 weeks 3 days 4 hours ago) and read 1302 times:
they just don't put out good white light. the other is that they are not bright enough for use as landing lights.
Many designs for aircraft lighting now use high powered LED arrays. I have seen then in general cabin illumination, panel lighting, logo-lights and other external lighting. Its only a matter of time before we see an LED landing light.
The engineering hurdles have consisted primarily of heat dissipation but it is being addressed.
Also, additional optics can make relatively low brightness LEDs as bright as you want them to be.
MD11Engineer From Germany, joined Oct 2003, 13602 posts, RR: 63 Reply 5, posted (9 years 3 months 4 weeks 1 day 6 hours ago) and read 1053 times:
Considering the amount of "peanut bulbs" (387, 1864, etc) we change every day, I wonder why LEDs are not used more in cockipt indication lights. Also I can´t imagine LEDs getting as hot as those light bulbs.
Klaus From Germany, joined Jul 2001, 21346 posts, RR: 54 Reply 6, posted (9 years 3 months 4 weeks 1 day 5 hours ago) and read 1046 times:
MD11Engineer: Considering the amount of "peanut bulbs" (387, 1864, etc) we change every day, I wonder why LEDs are not used more in cockipt indication lights. Also I can´t imagine LEDs getting as hot as those light bulbs.
No, especially the halfway modern LEDs use a lot less power than normal light bulbs. (And produce less heat in return.)
But (reliable) white LEDs aren´t around for all that long yet, and they´re still more expensive than the classic red, green and yellow ones.
You´d probably have to redesign the switches or instruments to accomodate the LEDs instead of conventional bulbs as well, so I guess it may not be seen as a high priority.
And you´ll lose the possibility to determine the status of an indicator light after a crash (characteristically broken filament). LEDs leave no such trace. Maybe that´s another reason, but I could understand why it might not be publicized a lot...
FredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26 Reply 7, posted (9 years 3 months 4 weeks 1 day 3 hours ago) and read 1032 times:
On one aircraft I'm very familiar with, we eventually got LED position lights. The fun part was that these LEDs were white until lit - i e, you couldn't see the colour of them when they were off! And naturally, the previously red/green glass was clear as well. This created a need for new procedures in maintenance that were not expected, in order to make sure the red colour lights went on the left side as the green lights were right and would have been wrong.
I thought I was doing good trying to avoid those airport hotels... and look at me now.
Klaus From Germany, joined Jul 2001, 21346 posts, RR: 54 Reply 8, posted (9 years 3 months 4 weeks 1 day 2 hours ago) and read 1026 times:
Yeah... you sometimes have to power them up to see what kind you´ve got.
Since coloured LEDs generate only the "right" colour anyway (through the properties of the semiconductor materials), there´s no need for a filter to mask the other wavelengths. And that´s another reason why they´re more efficient: A normal lamp wastes energy on creating the full spectrum, even though the filters will block most of it again.