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Topic: No Strobe Lights On The B787 Dreamliner
Username: audidudi
Posted 2013-01-04 01:15:00 and read 7848 times.

Sorry if this has been mentioned before, but I noticed that the B787 Dreamliner does not have strobe lights on the wing tips, but instead has just single flashing white lights. Why did Boeing decide to do this when almost every other commercial and private aircraft has strobe lights?

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: ak907
Posted 2013-01-04 01:37:19 and read 7835 times.

That is the new strobe light. It's an assembly of LED's that simply blink. The 747-8 has the exact same thing. Probably less maintenance and power intensive. I actually think it looks better, easier to see too.

[Edited 2013-01-04 01:38:24]

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: tdscanuck
Posted 2013-01-04 06:59:55 and read 7645 times.

Quoting audidudi (Thread starter):
Why did Boeing decide to do this when almost every other commercial and private aircraft has strobe lights?

Strobes burn out. LEDs generally don't (at least, not over the aircraft lifetime). I expect you'll see a lot of this going forward...almost all OEMs are switching to LED lighting everywhere they can.

Tom.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: vikkyvik
Posted 2013-01-04 07:53:37 and read 7611 times.

Quoting tdscanuck (Reply 2):
Strobes burn out. LEDs generally don't (at least, not over the aircraft lifetime). I expect you'll see a lot of this going forward...almost all OEMs are switching to LED lighting everywhere they can.

I was actually going to start a thread about this. Did Boeing do any studies regarding effectiveness of blinking lights versus strobes in recognizing and identifying aircraft? Did the different on/off config have to get approved by the FAA or anything?

Just curious, because it seems like the blinking lights would be less likely to attract my attention than the strobes.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: DashTrash
Posted 2013-01-04 08:04:29 and read 7601 times.

I'm not a fan of those blinking LEDs, but they are more noticeable that strobes. They are brighter, and the longer duration of them being lit gives you a longer opportunity to spot them.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: rfields5421
Posted 2013-01-04 08:16:15 and read 7573 times.

Quoting tdscanuck (Reply 2):
Strobes burn out. LEDs generally don't (at least, not over the aircraft lifetime).

LEDs do burn out, but a LED of that type will be composed of dozens of very small individual bulbs, so a few burning out will not require replacing the entire light.

Quoting vikkyvik (Reply 3):
Did Boeing do any studies regarding effectiveness of blinking lights versus strobes in recognizing and identifying aircraft?

I'm confused. Strobes blink also.

Just the fade in/ fade out are different due to the physical nature of the bulb.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: bond007
Posted 2013-01-04 08:23:06 and read 7566 times.

Quoting vikkyvik (Reply 3):
have to get approved by the FAA or anything?

As long as they comply with the FARs, which is a flashing light 40-100 cycles/minute, specific angles of visibility, and intensity, then they would not need any special approval other than installation related ones.

Remember, before LEDs, the only easy way to flash a bright light every second or so, was to use a strobe. You cannot flash an incandescent bulb fast enough, and even if you could, it's life would be very short.

Although LEDs have been around for some time now, white LEDs, especially high-intensity ones, are fairly new to the market.

Jimbo

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: pilotpip
Posted 2013-01-04 08:38:49 and read 7553 times.

One of the CRJ-200 operators has put them on the tail of the aircraft as well. I think it's Air Wisconsin. Makes sense, LEDs have a much longer life and that will save mx costs over their life. I'm also starting to see them used as nav lights on a variety of aircraft.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: vikkyvik
Posted 2013-01-04 09:10:57 and read 7525 times.

Quoting rfields5421 (Reply 5):
I'm confused. Strobes blink also.

I know. But I notice a strobe much more readily than a slowly-blinking light. Just catches my eye much quicker. Especially when looking down at the ground at night - there are plenty of slowly-blinking lights on the ground, but relatively few strobes, so it's pretty easy to identify an airplane.

That said, I'm not a pilot, so....

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: tdscanuck
Posted 2013-01-04 10:09:09 and read 7474 times.

Quoting vikkyvik (Reply 3):
Did Boeing do any studies regarding effectiveness of blinking lights versus strobes in recognizing and identifying aircraft?

I'd be surprised if somebody didn't, just because that would be a huge risk when you change technology. No idea if it was Boeing though.

Quoting vikkyvik (Reply 3):
Did the different on/off config have to get approved by the FAA or anything?

In principle, yes, but the just have to demonstrate FAR compliance (which never said anything about strobes).

Quoting vikkyvik (Reply 3):
Just curious, because it seems like the blinking lights would be less likely to attract my attention than the strobes.

I actually find they grab my attention *more*, but I can't tell if that's because they're inherently more attention-grabbing, or if it's because they don't look like strobes, hence look different than everything else, and that might not work so well once everyone has them.

Tom.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: CALTECH
Posted 2013-01-04 10:15:32 and read 7469 times.

They seem to be very bright and work just fine. Saw them at IAH, they are bright.

http://www.youtube.com/watch?v=m3subQWRGCY

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: IAHFLYR
Posted 2013-01-04 11:45:00 and read 7394 times.

Quoting vikkyvik (Reply 8):
But I notice a strobe much more readily than a slowly-blinking light. Just catches my eye much quicker. Especially when looking down at the ground at night -


As CALTECH said and the video shows they are very very bright and easy to see even in the daylight. I like the look.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: futureualpilot
Posted 2013-01-04 12:00:35 and read 7384 times.

Quoting vikkyvik (Reply 3):
Just curious, because it seems like the blinking lights would be less likely to attract my attention than the strobes.

From my own experience in my short time operating in and out of the same airports as the 787 and 747-8, the LEDs are significantly easier to acquire and keep track of versus the older and faster flashing strobes. This has made a difference mostly at night, against a city back drop or at a busy airport in a sea of lights.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: KC135Hydraulics
Posted 2013-01-04 12:15:19 and read 7367 times.

Our C-17s have new LED beacon lights. They don't flash, they just glow bright red when they cycle on. You can see them for MILES (farther than a flashing light bulb) and they are super high intensity without the epileptic flashing effect. LED lights are the future of aviation and they're awesome.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: tjwgrr
Posted 2013-01-04 13:56:04 and read 7305 times.

There are quite a few corporate a/c and some light singles which have been equipped with LED's for quite some time as well.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: TWA772LR
Posted 2013-01-04 14:10:14 and read 7292 times.

Those LED's are bright as H*ll!!! You can always tell a 787 at night when it's on approach to IAH. Is it just me or do the new white LED's kind of look purple, even in the slightest?

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: tdscanuck
Posted 2013-01-04 14:11:59 and read 7292 times.

Quoting TWA772LR (Reply 15):
Is it just me or do the new white LED's kind of look purple, even in the slightest?

I think their "white" is a lot hotter (blue/violet-er) than the previous strobes. I agree with you.

Tom.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: bond007
Posted 2013-01-04 14:55:01 and read 7239 times.

Quoting tdscanuck (Reply 9):
I actually find they grab my attention *more*, but I can't tell if that's because they're inherently more attention-grabbing, or if it's because they don't look like strobes, hence look different than everything else, and that might not work so well once everyone has them.

I think it's likely because the "on" time is much longer than a strobe. Even though it's flashing at the same frequency, most of the time spent between flashes for a strobe is time spent getting bright, and dimming again. The LED is simply on and off, with no in between, hence in theory at least, a longer "on" time.

...maybe  


Jimbo

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: CALTECH
Posted 2013-01-06 07:57:17 and read 6716 times.

Quoting TWA772LR (Reply 15):
Those LED's are bright as H*ll!!! You can always tell a 787 at night when it's on approach to IAH. Is it just me or do the new white LED's kind of look purple, even in the slightest?

At IAH what I noticed about the 787 white lights is that they did have a bluish tinge to them. They do seem more blue than white for the position, tail , 'strobes' and landing lights . All the so called white lights do have that bluish tinge to them, as in the nose gear taxi light in this photo.


View Large View Medium
Click here for bigger photo!

Photo © Andrew Compolo

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: sccutler
Posted 2013-01-07 21:03:31 and read 6311 times.

As a pilot, I find the LED "strobes" to be very much easier to spot in flight, and they generally consume less power, weigh less and create much less electrical "noise." there is no discernible down-side, to the point that I intend to replace all of the strobes and Nav lights on my plane with LEDs.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: FlyDeltaJets
Posted 2013-01-08 02:46:44 and read 6219 times.

Quoting pilotpip (Reply 7):
One of the CRJ-200 operators has put them on the tail of the aircraft as well. I think it's Air Wisconsin. Makes sense, LEDs have a much longer life and that will save mx costs over their life. I'm also starting to see them used as nav lights on a variety of aircraft.

ASA has them too

As mentioned above they are much brighter than traditional strobes.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: AirframeAS
Posted 2013-01-08 09:49:07 and read 6113 times.

Quoting rfields5421 (Reply 5):
I'm confused. Strobes blink also.

I wouldnt say that.... I would say that todays strobes flash, like a camera flash. The LED on the 787's blink.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: bikerthai
Posted 2013-01-08 12:08:44 and read 6066 times.

We cyclist have been the beneficiary of those LED's for years.

Starting with those flashing red LED and then the White LED's.

The blue hue you get with the "Cool White" LED is from the luminescence coating on the bulb that generate the light.

Most color LED is generated by the frequency of the emitting diode. The exception is white.

Because white require the complete spectrum, it is generated by shining a high power colored LED onto a luminescence coating on the bulb. The emission from the coating is what gives you the "white". And depending on the composition of the coating, you get varying hue of white.

As for applications of these LED's . . . it depends on the designers. Some LED car tail lights that are extremely bright and irritating and others warm and pleasing . . . depending on hue and intensity.

bt

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: Aesma
Posted 2013-01-08 20:21:22 and read 5949 times.

Quoting bikerthai (Reply 22):
Because white require the complete spectrum, it is generated by shining a high power colored LED onto a luminescence coating on the bulb. The emission from the coating is what gives you the "white". And depending on the composition of the coating, you get varying hue of white.

I don't know if "LED bulbs" are made like this, but when you don't need something looking like a bulb you don't bother, so white LED mostly look like this :



There is indeed some phosphorus in them, otherwise they would be blue.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: bond007
Posted 2013-01-09 04:25:26 and read 5843 times.

Quoting Aesma (Reply 23):
but when you don't need something looking like a bulb you don't bother, so white LED mostly look like this :

But that really is 100 small LED 'bulbs' , right?

It just so happens that even the larger high-power LEDs are very small, but still separate glass or plastic 'bulbs' of some description, each with a small lens.


Jimbo

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: bikerthai
Posted 2013-01-09 06:21:35 and read 5914 times.

Quoting Aesma (Reply 23):

From a layman's point, a LED light is actually a diode that looks like small computer chip. The chip has circuitry to control the frequency of the diode to emit specific frequency of light. You can imagine then the reason why LED would have problem with high power . . . the ability to dissipate heat energy from the chip.

That is why they have to do this:

Quoting bond007 (Reply 24):

But that really is 100 small LED 'bulbs' , right?
Quoting bond007 (Reply 24):
still separate glass or plastic 'bulbs' of some description, each with a small lens.

The lens is necessary to distribute the LED light to a broader angle. Otherwise you'll get a very narrow beam from each chip.

So tailoring LED light shapes (as opposed to an LED "bulb" which is just a lenses) is a matter of ganging a bunch of LED's (with lenses) on a circuit board (more than one board if you have complex light shape) and some heat dissipation mechanism along with an overall package (aerodynamic transparent cover and power interface).

The house hold LED bulb are cheap enough now that you can buy one and see how it works. I just recently bought some at Costco for $5 each to replace some of my compact fluorescence once those burn out.

bt

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: rwessel
Posted 2013-01-09 13:27:46 and read 5788 times.

Quoting bond007 (Reply 24):
But that really is 100 small LED 'bulbs' , right?

It just so happens that even the larger high-power LEDs are very small, but still separate glass or plastic 'bulbs' of some description, each with a small lens.

To expand on bikerthai's comments, I just put some of these:

hxxp://www.amazon.com/Feit-Electric-BPG161-CL-LED/dp/B0052YVD6O

(note: the forum software kept mangling the link, so you'll have to cut and paste it, and change the "hxxp" to "http")

and some similar "flame tip" style bulbs in some hallway fixtures that are constantly having incandescent burn out and are a pain to change. They look great, BTW.

Anyway, as you can see in the photograph, these have nine LED chips with nothing more than a thin clear plastic coating/diffuser over the chips mounted on a central pyramid. No bulb.

The flames have a more sophisticated lens/diffuser, but the same chips are hidden in the base.

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: bond007
Posted 2013-01-09 15:16:52 and read 5758 times.

Quoting bikerthai (Reply 25):
is a matter of ganging a bunch of LED's (with lenses) on a circuit board
Quoting rwessel (Reply 26):
these have nine LED chips with nothing more than a thin clear plastic coating/diffuser over the chips mounted on a central pyramid. No bulb.

Yes, I understand the technology, which is why I put "bulb" in quotes  

Technically, depending on the definition you read, a light bulb can only be of the incandescent type.


Jimbo

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: timz
Posted 2013-01-09 17:03:38 and read 5719 times.

Quoting FlyDeltaJets (Reply 20):
[LEDs] are much brighter than traditional strobes.

They look brighter-- but presumably the strobe's intensity during its flash is vastly greater than the LED's?

Or are aircraft strobes that much weaker than camera strobes?

Topic: RE: No Strobe Lights On The B787 Dreamliner
Username: HAWK21M
Posted 2013-01-09 22:56:39 and read 5638 times.

As Long as the New lights are effective on the type.....it serves the purpose & does not violate regulations.


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