L.E.D. Navigation/Strobes/Interior Lights

[W.J.Langholz]

George

Really nice work on the interior lights, thanks for posting the pics.

Now what would really be nice is if you would post some pics on the nav light also. I followed most ie reflector tape or tinfoil on the inside but like they say a pic is worth 10,000 words

W.

By the way did you and Del ever get and STC for the dual landing light set up?

[Bruce Fenstermacher]

Looking at the LED site you posted I'm getting a bit excited. I might be able to drop about 10 amps or half my amp load at night. For testing on the ground anyway.

George the bulbs 0511060 used by the stock back lighting in our instrument panels cross to a 1816. I see the BA9S is the same as an 1815 and 1819. Do you know if the 1816 has the BA9S base?

[GAHorn]

Interior lighting has no regulatory requirements. Whatever works for you ...is just fine.

No STC yet for the dual landing/taxi light installation ...and none required if you purchase the modification from Del/Mountain Airframe. (He owns the engineering approvals.) Contact Del directly. http://www.mountainairframe.com/ 479-437-3333

The BAS9S units are interchangeable miniature bayonets with the 1816 lamps, but beware.... if your 1816 lamps utilize the side-illumination of the incandescent bulbs.... you'll need to purchase side-firing LEDs to achieve the same effect. (LEDs are directional.)

And yes... I figured this topic would be a very useful one for many of our members. Much electrical-demand can be reduced by using the LEDs...and the HEAT.... is HISTORY! ( I feel confident I could leave all my nav and all my interior lights on ALL NIGHT LONG and return to the aircraft the next day with a battery still fully charged. (as long as the T&B is not hot-wired "on".)

If the LED nav light replacements can be shown to meet the FARs 21/25 (or CAR3) requirements then they should be legal to use. I have not yet proven that is the case, except in personal observation they appear to do so. I hope to consult a FAA-DER in Austin this week regarding this matter.

[Bruce Fenstermacher]

Yes I was thinking of one of the side firing models for the back of the instrument panel in the stock locations. Would be interesting what the DER has to say.

It has been a while since I looked at a Whelen or Grimes bulb base. You mentioned filing off one of the pins of the 1156 to fit the socket. Isn't the stock pin configuration staggered like the 1157? I seem to remember trying an 1157 in a Grimes rotating beacon years ago and didn't use it because it had twice the amperage draw and probably heat than the stock bulb.

If so I know the 1157 has dual contacts at the base but they could be soldered together or even left alone the socket base would contact both and light all the LEDs. This would make even more light and unlike the 1157 the high amperage and heat would not be a problem.

[GAHorn]

The original nav lamps have staggered pins on their bayonet bases in order to orient the lamps with their mirrored sides aft. The 1156 single-contact base will require one pin to be ground/filed off in order to seat to the proper depth in the wingtip fixture. No problem with that. (Also it's a good idea to use a dab of DC-4 Silicone-grease on lamp bases to fight corrosion.)

The LEDs have a fixed number of emitters, regardless of whether they are 1156 or 1157 types. The 1157 dual contact LEDs only light up half their emitters ordinarily ...until the second contact is also excited....while the 1156 LEDs illuminate all their emitters continuously. (The 1157s are intended for parking-light/turn signal and stop/turn lamps.) So no advantage is gained by using them.

[Bruce Fenstermacher]

I haven't ever measured the light levels but I've always considered an 1156 as a marking light and an 1157 as a marking light and a brighter brake light. In other words the low level of the 1157 was equal to the 1156.

Interesting if what you say is true about the 1157 equivalent LED firing the same amount of LEDs with both circuits energized and less than that and therefor less LEDs than the 1156 with the low circuit energized. That would mean that the 1157 in the "brake light" configuration wouldn't be any brighter than an 1156 and would be dimmer otherwise. Don't think that would work in the automotive application.

The only reason I bring up the 1157 is that it does have staggered pins and should fit the nav light socket without modification. If the light is equal to the 1156 fine, if the 1157 is brighter that is even better.

[GAHorn]

Here's the official data from GE. Their 1156 is not a "marker" light...it is a "backup" light and is rated 27 Watts. The 1157 is a "stop/turn" lamp and is rated at 8 Watts...until both contacts are excited...then it's also rated at 27 Watts. They are BOTH capable of the same Lumens (comparing the 1156 with both elements of the 1157 excited) - 402.

=================
GE 1156


S8 Single Contact Bayonet (BA15s) WATTS = 27, Initial Lumens 402
Voltage 12.8
Rated Life 1200 hrs
MOL 2 in (50.8 mm)
ANSI Code 1156


===============
GE 1157


S8 Double Contact Index (BAY15d) WATTS= 27/ 8 Initial Lumens 402 / 38
Initial Lumens (Hor) 14.88889 / 4.75
Initial Lumens (Vert) 402 / 38
Voltage 12.8 / 14 / 1200 / 5000
Rated Life 1200 / 5000 hrs
Rated Life (Min) 27 / 8 hrs
Rated Life (Hor) 27 / 8 hrs
Rated Life (Vert) 1200 / 5000 hrs
MOL 2 in (50.8 mm)
ANSI Code 1157

However, notice that at 27 Watts the 1157 lamp only has an 8-hr life expectancy, while the 1156 has a 1200 hr expectancy.

As a comparison, consider my "illegal" use of an 1156 in place of the "approved" GE 93 for the rudder/tail lamp. Here's the 93 data:

=============
GE 93


S8 Single Contact Bayonet (BA15s) 13 WATTS Initial Lumens 188
Voltage 12.8
Rated Life 700 hrs
MOL 2 in (50.8 mm)
ANSI Code 93


I feel that since the 1156 is not only much brighter, and longer-lived,... its use is defensible.
(Its dimensions and weight are the same, and they are both automotive lamps.) The use of an LED version 1156 is even better, IMO.

[GAHorn]

Re-thinking about your last comments, Bruce.... you are right, of course. Your comment is relative to the split-pin (dual contact) base and the comparison data I posted regarding the 1156/1157 lamps are irrelevant as applicable to the LED versions. I do not know the electrical scheme* of the LEDs and whether or not any conflict would exist in allowing (or hoping) both contacts to be co-joined. The security of removing one pin on the 1156 base seems not to be compromised, as the lamp is held quite securely with one pin. (In fact, I had to unscrew the fixture's spring-contact to relieve the acquisition of the fixture upon the LED...in order to remove it....same as with the original Whelen/Grimes lamp.)

* The LEDs will glow very slightly even without a proper grounding circuit if power is supplied to them, so I do not know how simultaneously applying power to both contacts of an 1157 LED might "play" in the scheme of things. I know the 1156 LED works fine with one pin removed.

[Bruce Fenstermacher]

I guess I am thinking about another incandescent bulb and not the 1156 for marker lights.

As I said I once put an incandescent 1157 into a grimes rotating beacon. Both pins at the bottom made contact with the single pin in the socket and of course the base of the bulb is a common ground for both elements. Any replacement LED light would have to have the same electrical scheme.

So it would seem to me assuming the socket center contact made contact with both bottom bulb contacts that the 1157 LED version would work as well as the 1156 without any modification. I wouldn't be afraid to bridge the two contacts at the bottom of the LED version of the 1157 with solder to insure both circuits where energized. Whether you remove a pin or connect the contacts is probably six of one, half-a-dozen of another.

FYI don't use an 1157 incandescent to replace the correct bulb in a grimes light. The amperage draw is about twice the correct bulb and the heat will probably melt any plastic near it.

[Indopilot]

George, not trying to beat a dead horse, but did you determine no change in the balance by doing a balance test of the rudder or by weighing the components and finding them exactly the same? My concern is with the long arm back to the nav light it doesn't take much to throw the balance out. A light coat of paint will do it in some cases. Brian

[GAHorn]

The lamp weight differences are insignificant. Have you looked at the rudder balance data recently? It is very wide in lattitude and not likely to be bothered by the lamp change, or whether any lamp is installed or totally missing, even. (FOUR pounds of weight and +23 - 27 in/lbs balance, are the limits.)

[GAHorn]

The electrical engineer I'm consulting on this project had a better way of explaining light emissions. (as opposed to night emissions, bluEldr)

Light spectrum is measured in "degrees" of "kelvin" (which is a different thermometer than Celsius or Fahrenheit and uses a different conversion-table than when converting Celsius to Centigrade, HawkerCFI).

Essentially, aviation Green is about 500K and aviation Red is about 680K. When a cool-white LED shines thru an aviation red or green filtering lens it filters out everything except the spectrum in those temperature ranges. Since an incandescent lamp creates more color-temp within those ranges, the lenses will allow that greater amount of that color to pass through. However the cool-white LED lamp produces less light in that color-temperature, so less light is visible after it passes the lens. That's why the color-shift also occurs. The "fix" is to utilize lamps that produce more light within the color-temp that is desired. So the use of a Red LED will result in more Red light spectrum being passed thru the filter (lens).

I have a set of red and green LED's on the way, and when I test them I'll report the results. (The shipping sure adds to the cost of this project. Every time I order another couple of LEDs, not only the cost of the LEDs are incurred... but another $6.44 shipping! So far I've had 4 different sets of lamps, and now it'll be at least another set. Maybe I should just buy the Whelen units. )

[Bruce Fenstermacher]

Maybe I should just buy the Whelen units. )

Not yet George. Your saving me a lot off shipping.

[GAHorn]

Well, they're $210 apiece from Whelen.
PN 01-0271134-01 , 7113401 Assy, Pos. LT. 14V Green 71105 Series 210.00
PN 01-0271134-02, 7113402 Assy, Pos. LT. 14V Red 71105 Series 210.00

http://www.whelen.com/pb/Aviation/2009_ ... e_List.pdf

It's the absolutely legal way to do it, at present.



Or, if you already have the wingtip strobelight system, you can simply replace the entire wingtip units and get new strobe-lamps included:
01-0771110-01 Position Green, 14V 11-05630 $293.50
01-0771110-02 Position Red, 14V 11-05633 $293.50


Or get the entire installation including power supply if you only have original nav lights and wish to install a new wingtip strobe system. ($1049 for two wingtip nav/strobe combination units, including the req'd power supply and the installation kit which includes the wire, connectors and paperwork.)


Here's a link to the Spruce online catalog: (You'll want the #5 system, 14Volt)
http://www.aircraftspruce.com/menus/el/ ... vwing.html

[GAHorn]

OK, Well, I believe I'm at the point where I can say without reservation that the RED and GREEN LED's, installed in the wingtip positions are GREAT! The color is correct, and the brilliance is as good at night as the original incandescent lamps. I am IMPRESSED!

I attempted to take pics but my camera doesn't do justice to the matter. Up-close, within 5' to 15' ....the LEDs appear to have small areas about 45-degrees right or left somewhat dimmer than incandescents. However, moving farther away, say farther than 25-30 feet, the diffusion of the light-angles dissappear and the LEDs appear every bit the same as incandescent, and just as bright. I'd venture that unless you knew about it, no one would notice. If I back off 50' and look at both airplanes, one incandescent and one LED, they appear exactly the same except in certain angles the LEDs have a sharper brilliance (probably the result of when an individual LED is pointed directly at you.) Even farther way, more than 150' the two systems cannot be distinguished, one from the other. I hope to get the DER in Austin to agree without an expensive program of something other than light-meters and color-check. Whether the SAT-FSDO "rear-seat-squad" will go along with it may be another matter.