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RV8R999

Well Known Member
After a little research I found a great source for some really nice (and inexpensive) LED lamps for both NAV and Strobes.

The company is SuperBright LED, INC (www.superbrightled.com)

BA15-30-Red and Green

BA15 5Watt white (1156-WLX5) for strobes

Universal Motorcycle flasher - LF1-S-PIN for strobe functions.

Plan is use two red and two green lamps per wing tip as well as Two white strobes per wing tip (one facing forward and the other laterally). One lamp in the rudder.

For pictures see my log: http://www.mykitlog.com/users/display_log.php?user=kenkg&project=675&category=0&log=79875&row=2
 
Intensity Issue

RV8R999 said:
After a little research I found a great source for some really nice (and inexpensive) LED lamps for both NAV and Strobes.

The company is SuperBright LED, INC (www.superbrightled.com)

BA15-30-Red and Green

BA15 5Watt white (1156-WLX5) for strobes

Universal Motorcycle flasher - LF1-S-PIN for strobe functions.

Plan is use two red and two green lamps per wing tip as well as Two white strobes per wing tip (one facing forward and the other laterally). One lamp in the rudder.

For pictures see my log: http://www.mykitlog.com/users/display_log.php?user=kenkg&project=675&category=0&log=79875&row=2
Click to expand...


The FAR (23.1401) has a worst case intensity requirement of 400 effective candela ( plus and minus 5 degrees of elevation) for strobes. For the sake of discussion, lets forget about what it takes to get 400 cd effective from a flashing light (it takes more than 400 cd). The LED "bulb" you mentioned is rated at 134 lumens with a beam angle of 180 degrees. Basically that says it is radiating the 134 lumens out over a hemisphere or 2*PI steridians. Assuming that it is radiating uniformly over the hemisphere (and it probably isn't), that would yield about 21.3 candela (a lumen is defined as the amount of luminous flux required to produce an intensity of 1 candela over 1 steridian solid angle). Now in each wing tip, you are limited to 0 to 110 degrees horizontal because of the geometry of the cut out. Lets just roughly call that 1/4 sphere or about PI steridians (its actually a bit more). Even if you could get 100% reflection from mirrored surfaces in the wing tip that would still only get you 42.6 candela and even with two bulbs per wingtip it would still be only roughly 85 candela - far short of the requirements.

Now if you really want to get into this, you have to look at what the radiation pattern really is for the bulb (I suspect it's Lambertian, which would actually help) and what vertical angles have to be covered with what intensities, etc. But ultimately I would really doubt that the setup you have described meets the FAR. :(
 
Dan - From and engineering point of view you are correct. A couple of points though..

How many "CERTIFIED" airplanes actually meet the "required" intensity stated in FAR 23? Crazed lens, smokey filters, aging strobe supplies...etc...I'd venture not many.

I placed my whelan strobe and Nav from my other plane on the bench along side the LEDs and I can tell you from the Naked eye perspective the two Nav LEDs were noticiably more intense than the certified version at angles far exceeding the specs for the bulb - which was my biggest concern. My whelan's are in decent condition but not perfect - typical of any 20-30 year old plane on the ramp I'd say.

I'd also be interested in the link between FAR's requiring an amature built plane to meet those lighting requirements? Not saying it doesn't exist but it sure isn't easy to find - in general FAR Part 23 does not apply to our RV's with a few notable exceptions (ELT, Tranponders, Radios,..) not sure about lights.

In either case if the DAR shows up with his calibrated candella meter I guess I'll be Day VFR only since lights are not required for that. Either way I'm good with it as this system will in fact do what is is meant to do....

Regards,

Ken
 
RV8R999 said:
I'd also be interested in the link between FAR's requiring an amature built plane to meet those lighting requirements? Not saying it doesn't exist but it sure isn't easy to find - in general FAR Part 23 does not apply to our RV's with a few notable exceptions (ELT, Tranponders, Radios,..) not sure about lights.

In either case if the DAR shows up with his calibrated candella meter I guess I'll be Day VFR only since lights are not required for that. Either way I'm good with it as this system will in fact do what is is meant to do....

Regards,

Ken
Click to expand...
Part 91.205 is the requirement rule for lights. It applies to amateur-built aircraft for night/IFR operations by note in operating limitations. These lights must meet the requirements of part 23.

As far as the DAR showing up with measurement equipment, that's not required. It's up to the operator to determine if the lights meet spec.
 
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Requirements

RV8R999 said:
Dan - From and engineering point of view you are correct. A couple of points though..

How many "CERTIFIED" airplanes actually meet the "required" intensity stated in FAR 23? Crazed lens, smokey filters, aging strobe supplies...etc...I'd venture not many.

I placed my whelan strobe and Nav from my other plane on the bench along side the LEDs and I can tell you from the Naked eye perspective the two Nav LEDs were noticiably more intense than the certified version at angles far exceeding the specs for the bulb - which was my biggest concern. My whelan's are in decent condition but not perfect - typical of any 20-30 year old plane on the ramp I'd say.

I'd also be interested in the link between FAR's requiring an amature built plane to meet those lighting requirements? Not saying it doesn't exist but it sure isn't easy to find - in general FAR Part 23 does not apply to our RV's with a few notable exceptions (ELT, Tranponders, Radios,..) not sure about lights.

In either case if the DAR shows up with his calibrated candella meter I guess I'll be Day VFR only since lights are not required for that. Either way I'm good with it as this system will in fact do what is is meant to do....

Regards,

Ken
Click to expand...

Fact is, if you intend to fly at night, your lights are supposed to meet the intensity and coverage requirements spelled out in 23.1401. For a new airplane, the requirements are MUCH higher than for a "20-30 year old airplane" The only thing different with experimentals is that YOU get to be the one who "certifies" that it is so. My only reason for posting here was to point out to you (and anyone else that reads these posts) that, in my opinion, the lights as you have described them are not even close to meeting the spec just in case you/they hadn't given it much thought. It's your airplane and you can certainly do anything you want. I would agree that the chance of getting busted by the "strobe police" is slim to none. That still doesn't make the lights compliant with the FAR.
 
LED Lights

Dan et al.,

Don't get me wrong I get your point of view with respect to the specs.. I'm looking at the practical application first. If these lights are as good or better than legal lights of 20-30 years ago AND I with my own eyes..I believe they are...then the question for me is do I really need to comply with part 23?

Part 91.205 section A day VFR only applies to "standard Category" aircraft

Parts 21.191 and others refer to "Special Category" - of which Experimental Amature built is 1 of 8 types.

91.205 section B says only aircraft with a type certificate need comply with at least part 23 for lighting but that ALL US registered aircraft must have lights. We certainly fall under the requirements to have lights for Night VFR/ or IFR flight but are we "Type Certified"??? Hmmmmm

Again - not being a lawyer I don't see it being very definitive as some would believe.

Good discussion...

Ken
 
You're right Ken - you probably won't get busted because no one is reasonably going to be enforcing the rules - you MIGHT get unlucky someday and find an FAA guy watching night take-offs and landings at an airport that could make life sticky - but I seriously doubt it. That negates the need for a lawyer. (BTW, since Mel makes his meager living as a DAR, I have generally found his interpretations of the FARs to be pretty accurate - he deals with FSDO's all the time.)

However - my feelings have always been towards the utility of things - and lights are utilized to make us visible to other pilots. The question is if you feel you have done your duty towards other airmen by making yourself visible. Personally, I err on the side of as much light as possible - the FAR requirements are pretty minimal....

Paul
 
But the physics...

RV8R999 said:
Dan et al.,

Don't get me wrong I get your point of view with respect to the specs.. I'm looking at the practical application first. If these lights are as good or better than legal lights of 20-30 years ago AND I with my own eyes..I believe they are...then the question for me is do I really need to comply with part 23?

Part 91.205 section A day VFR only applies to "standard Category" aircraft

Parts 21.191 and others refer to "Special Category" - of which Experimental Amature built is 1 of 8 types.

91.205 section B says only aircraft with a type certificate need comply with at least part 23 for lighting but that ALL US registered aircraft must have lights. We certainly fall under the requirements to have lights for Night VFR/ or IFR flight but are we "Type Certified"??? Hmmmmm

Again - not being a lawyer I don't see it being very definitive as some would believe.

Good discussion...

Ken
Click to expand...

...and the data sheets say you are not getting as much light as required - I'm talking nav. lights, non-flashing, here - so your eye is probably decieving you somewhat, probably because of the intense point source of the LEDs.

Try your experiment with a new set of certified red/green lights and try at a much longer range, like a 1000 ft. or so...

Keep the comparison for new equipment to new equipment.
 
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Nav lights and FAR's

Guys (and Gals), Mel is right on here. Your limitations clearly state that you must be in compiance with the FAR's in certain areas, the relevant one here being lights for night flight. Right now we have a lot of freedom with our airplanes. Let's not get too cocky and decide no-one is watching therefore "I" can be the judge of what is right. Keep in mind that others are sharing the airspace with you, and everyone is expected to abide by the rules.

Vic
 
Yep, I'm going to add to all the other good posts here with one more datapoint.

When I built my RV I assembled kit LED nav light similar to these:\

http://www.killacycle.com/Lights.htm

The plans called for slightly different mounting angles to meet the very particular radiation pattern required for certified lights. Then they gave instructions for using a light meter to verify the installed lights meet spec at all positions.

I don't think just plopping two of those LED units down will meet the requirements.
 
Perplexed by the number of guys stating a clear requirement exists for abiding by FAR 23 for A/C lighting I took a look at my BD-4 operating limitations issued in 1976 and there is no mention of equipment needed per 91.205.

A google search of the latest FAA order 8030.2d does in fact include verbage linking night or IFR flight equipment requirements to 91.205...and by association Part 23.

My fault for assuming my BD4 limitations would be similar to todays...I stand corrected.

No cockyness here - I follow the rules, not assumptions, myths, local common practise or otherwise. I do believe, as the builder and person singly most responsible for the airworthiness of my plane, I am qualified to make decisions when deviations from the norm are made. Particulary in the case where specific regulations do not exist...In this case I was in err on the current operating limitation verbage and will adjust my lighting decisions accordingly - thanks for all the feedback.

From professional experience I might add, the quickest way to lose freedoms is by not exercising them to the limit - regularly.

Ken
 
What's approved?

One other thing that has been mentioned on previous threads, but always stirs up a little debate, is the wording of the requirements in 91.205 for night VFR. That would be:

(2) Approved position lights.

(3) An approved aviation red or aviation white anticollision light system on all U.S.-registered civil aircraft. Anticollision light systems initially installed after August 11, 1971, on aircraft for which a type certificate was issued or applied for before August 11, 1971, must at least meet the anticollision light standards of part 23, 25, 27, or 29 of this chapter, as applicable, that were in effect on August 10, 1971, except that the color may be either aviation red or aviation white. In the event of failure of any light of the anticollision light system, operations with the aircraft may be continued to a stop where repairs or replacement can be made.

The question is, what does "Approved" mean? Does just meeting the standards satisfy the "Approved" requirements, or do you actually have to submit your lights to the FAA for approval? Or is "I'm Tracy Hallock, and I approve of these lights..." good enough?

Just trying to keep things lively,

Cheers,
Tracy.
 
A buddy just dropped a pair of "automotive" 1156 type red and green LED bulbs in his airplane and I can tell you that he stands out at night from MILES away better than any other aircraft I've seen yet. These are $8 dollar bulbs mounted behind a clear wingtip lens and no reflector. A set of these is going on my next airplane, no doubt.
 
Just a few comments based upon the work that I have done on my LED solution for the NAV lights. While many of the availalble LED lights have to use LEDs mounted on multiple planes to achieve the required distribution of light it is possible with the right LEDs to meet these specifications with the LEDs mounted only on a single plane. Most LEDs however do not have a wide enough distribution of luminance to cover the required angles. I have been able to figure out a solution which only requires 4 LEDs per wing tip that fully meets the FAR so it can be done and it isn't complicated.
 
DaleB said:
I see a lot of automotive type white LED bulbs (including those mentioned by Cyrus above, http://www.aircraftspruce.com/catalog/elpages/navstrobe11375.php ) that say they turn on solid the first time, but if you cycle power within 3 seconds they start a "fast flash" or "fast strobe" mode. Has anyone played around with these to see what the "fast flash" mode is like?
Click to expand...

I have recently seen a set of the NavStrobe LED's in use on a friend's Cherokee. They sound on paper like an excellent idea, but unfortunately they may not be quite stable yet. On his Cherokee, when you turn them on, they occasionally come on with one of the three flashing. So you have two solid, and one flashing. Cycle the power, and now you have two flashing and one solid. The only way to reset is to remove the out-of-sync bulb and cycle the other two.

If there was a way to ensure that they always came on in a known state, I think they would make a lot of sense for retrofit applications.
 
Kuntzleman

I have Kuntzleman combination LED navigation and strobes on my RV-8 which work well and were reasonably priced
 
MORE than enough

Hon. Paul Dye sez: Personally, I err on the side of as much light as possible - the FAR requirements are pretty minimal....

Paul

So, THAT explains the purple lights (on the bottom side of the plane) he turns on when he taxis in at night...I guess we can't hear the boom-thumpa-thumpa of the stereo...:D

"Geez - I crack myself up!"

Carry on!
Mark
 
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