Question about lighting options

apatti · #1 03-30-2006, 09:24 AM

All,
I was reading a thread from last summer that talked about LED position lights and whether or not they are legal. Mel (the resident DAR) stated that:

"The DAR/FAA inspector does not certify the lighting system per sey. Your Operating Limitations will state that "After completion of phase I flight testing, unless appropriately equipped for night and/or instrument flight in accordance with part 91.205, this aircraft is to be operated day VFR only." This puts the monkey on your back. If the aircraft is apporpriately equipped, you may fly at night."

I am interested as to whether or not anyone has had a problem with a DAR or the FAA when using LED position lights. If you get ramp checked, does the FAA have to prove your lights don't meet the FAR's or do you have to prove they do? How would you do this?

Thanks,

gmcjetpilot · #2 03-30-2006, 09:41 AM

I was one that may have levied that comment about legality.

I can't speak for Mel, but that is my understanding that the DAR does not certify the airplane per se, you do. You are responsible to make sure it meets the applicable regs.

My comment was these LED NAV lights some are marketing may not meet the spec. What specs? Part 23. Well we don't need to meet part 23 as a whole, but I was told (forgot the logic) we need to meet the NAV light specs? It was not the FAA who told be this; I think it was when I called Whelen and they of course wanted me to buy a "certified" tested system. When I did ask the FAA about "non-aircraft" strobes they where not phased. As long is its safe is what I gathered.

The other story goes that NAV lights are one of those things that needs to meet "specs". Transponders are another one of those things that must be TSO'ed. Makes sense because it works with ground radar. IFR GPS another one. It is one topic that either no one knows anything about, and if you find an opinion, you will find many other differnt opposing opinions. I am indifferent. I personaly have the good old incandescents.

I would ask some hard questions of the LED NAV light manufacture. Look if they are TOO bright or have brightness in directions, they are not suppose to than they will not do the job intended. We rely on the light having a very complex pattern, coverage to judge position of other planes.

Measuring LIGHT intensity and wave length (color) is harder to do. I mean if your NAV lights look Orange, Blue and Yellow, you might get a complaint. The NAV spec gives very spacific wave lengths for the different colors. The hardest to reproduce with LED's is the RED. They make them but it may be good to ask the maker of the NAV light what wave length the RED/GREEN are at. If they have no idea I may look for a differnt manufacture.

I read the spec and some of the homegrown LED NAV's look like they shot gunned (DickCheney'ed-It) with a bunch of LED's and could not meet the spec. They also look like if one burns out it would be hard to repair. I noticed the TSO'ed 28 volt LED NAV's use reflectors to get the full output of the LED's. The Home-grown ones with 28 LED's look crude to me.

Is it a big deal? I don't know. I doubt a DAR would say anything, or the FAA would call you on it. I would say if you have one of those homemade or bought LED NAV's from a vendor, I would get the spec out and check it out as best you can by inspection. YOU verify it meets the specs to your best ability.

If there is proof needed you are the one who needs to prove it. If you are one of those people that wants to do it right, than you have some homework to do. The other way is use a "standard" or TSO'ed system and be done with it. If you don't care and just want to get it past the inspector, than throw what ever in there. I have seen some real bad home made NAV lights over the years.

Chance is it will not be questioned, ever. If it is close to RED, GREEN and WHITE and of reasonable intensity and coverage it will do, just depends on if you care or not.

Here is some info:
http://www.periheliondesign.com/down...tionlights.pdf
http://www.risingup.com/fars/info/part23-1383-FAR.shtml
http://www.risingup.com/fars/info/part23-1385-FAR.shtml
http://www.risingup.com/fars/info/part23-1389-FAR.shtml

George

Mel · #3 03-30-2006, 01:51 PM

George,
Are you sure I didn't see you playing me on TV the other night? I thought for sure that was you.

Mustang · #4 03-31-2006, 11:36 AM

I got a set of LEDs from Creative and installed them. The manufacturer supplied a sheet with all the candle power for all the directions required which exceed all the minumum criteria.

These are very visible lights and the reds burn with the fury of ****.

Oh! And the current draw is minimal. The whole circuit will run on a 5 amp breaker, probably less. I think the current required is 2.5 watts per unit, approx.

Cheers, Pete

apatti · #5 03-31-2006, 04:30 PM

Pete,
Thanks. That helps a lot. Yes, one of the reasons I like the LED lights is the low current draw. I read that the LED's are more efficient because they produce the light at the required wavelength (red or green). Normal lights produce white light and all wavelengths except the desired ones have to filtered out with a lens. Makes sense to my simple mind!

Tony