The International Cessna 170 Association

Summary & Disclaimer: This is not an "approved" replacement lamp by authorities, despite the fact that Cessna has abandoned FAA-PMA lamps for taillight fixtures and now lists a common automotive lamp for the tail nav light, and despite the fact the LEDs will meet/exceed light output while drawing incredibly lesser amounts of current and produce nowhere near the heat of incandescent lamps. Whelen now produces approved LED navigation lamps for aircraft should this experiment convince you as well as it did myself, to convert to LEDs. <EDIT> However Advisory Circular 23-27 provides the basis of approval for using automotive lamps in aircraft built before Jan '71. I have been using these in my airplane now for 2 yrs and am very satisfied with them. One should make a log entry to the effect that LED "standard part" lamps have been installed as direct replacements. IMO

I've read this thread (and AC 23-27) several times and I still can't make a decision.

If the LED lights are considered standard parts,
...and an aircraft owner is authorized to replace Nav lights
...does this mean that I can replace my Nav lights with the LEDs with nothing more than a log entry made by myself?

It doesn't seem like it should be that easy.

-David

You can "replace" the existing lights with the same approved type. Altering the original design with a new type of light not previously approved is considered an "alteration" to the original design and requires a basis of approval and a sign off by a mechanic and/or IA depending on the type of alteration.

but in this case, the light is a standard part and as such is approved the same way as any AN bolt or other standard part.

I found this other thread where George did some great leg work for all of us and seems to have cleared it up.

http://www.cessna170.org/forums/viewtop ... =24&t=7323

The mfr'r states they qualify under the provisions of Standard Parts per FAR 21.303(4) and per AC 23-27 and also that they meet the Mil-Specs for such lamps (Mil 45208A, Mil-STD 45662 and Fed. STD WL 00111, and they are made per ISO-9000. Like AN bolts and other standard parts they do not require additional approval.

I found that thread after posting my question here.

So, replacing the NAV lights with another standard light (that happens to be an LED) should require nothing more than a log book entry by the owner/operator.

Just in case, I'll keep a print out of all the supporting documentation in the plane in case I get ramp checked.

Cheers,
-David

I don't believe the FAA has given pilots performing preventive maintenance the authority to "determine airworthiness" of parts they want to substitute for approved parts. I believe the FAA's question would be "who made that determination" and "where is their log book entry". If previously installed and documented by an A@P I don't think replacement by a pilot would be a problem.

FredMa wrote:I don't believe the FAA has given pilots performing preventive maintenance the authority to "determine airworthiness" of parts they want to substitute for approved parts. I believe the FAA's question would be "who made that determination" and "where is their log book entry". If previously installed and documented by an A@P I don't think replacement by a pilot would be a problem.

I would disagree Fred. In fact I as the owner can do something my IA can't do and that is manufacture my own parts and certify their airworthiness though, depending on the part, I concede, I may not be legally able to install it under the Appendix A Preventive maintenance.

And aren't I the owner operator the final authority as to the airworthiness of my aircraft to include any parts a A&P would install. I must therefor be able to determine if a part is airworthy of not.

I don't think I'd be determining airworthiness of the part in this case. (Other than verifying they work after installation).
The FAA has given us guidance on what a standard part is and this light falls into that category.

This isn't a modification of the aircraft. Based on everything I'm reading, this is the replacement of a standard part with another (newly available) standard part.
It shouldn't be any different than the modern O-rings in my fuel selector, the improved materials in my brake lines, the polyethylene tubing in my static system or the Tefzel wires all over the place. None were approved for my airplane but all are considered standard parts today and require no special approval.
Granted, I as a pilot can't make use of ANY of those items under preventative maintenance but I think that's besides the point.

For all I know, my inner tubes are made from a different material than the originals...but I'm sure they conform to some standard.

Ok, that was a little provocative. I'm not trying to start an argument.

I think I've figured out the answer. I guess I'm just looking for someone on the forum to agree with me when I should probably be talking to my IA about the matter.

bagarre wrote:...For all I know, my inner tubes are made from a different material than the originals...but I'm sure they conform to some standard.....

Actually,.... no approval for inner tubes currently exist as far as I can determine. The previous approvals were based upon U.S.A.F. Mil-Spec.....and that approval has been deemed obsolete. No current approval basis exists for aircraft inner tubes. (Go get 'em from Tractor Supply.)

Does that mean I have to land on my bare axles?

No But it means anyone/everyone who is using inner tubes younger than 1982.... are operating with UN-approved inner tubes.

Bruce, you are making assumptions and trying to use common sense. That does not apply when dealing with the FAA and The FAR's

Bagarre, My point was that no one has determined that this is an approved part that is qualified to do so. Sure a mechanic can do so in the examples you gave but we aren't talking about a mechanic, we are talking about a pilot doing preventive maintenance. Where does it say in the FAR's that a pilot can make a determination of approved alternate parts?

Below is a screen capture from Spruce. They say there LED bulbs meet FAR 23-1391 and are Mil Spec.

Electrical - LED Lighting - LED Replacement Lamps

LED REPLACEMENT LAMPS FOR NAVIGATION LIGHTS - 12V

Upgrade your Red & Green Navigation Lights to LED's. Replaces standard lamps in Whelen, Grimes, and Hoskins Navigation lights. It's simple! Just replace your old incandescent bulbs with our new LED lamps and you are ready to go. Longer life, runs cooler, draws less than .2 amps, 43 candle power, and meets FAR 23-1391 and is Mil Spec.

Click here to view more details.
11-07744 LED7512-12V RED LAMP $32.50
11-07745 LED7512-12V GREEN LAMP $32.50
11-07748 LED75TPL-12 TAIL POSITION LAMP $33.75

Well Fred I think your getting rapped up in thinking these LED replacement bulbs are ALTERNATE parts.

By virtue of the fact the FARs allow a Private Pilot or better to repair and or replace worn parts under certain circumstances with limitations means that authorities believe a Private Pilot must be able to determine what parts, if any, can be used to effect those repairs or replacements.

If you have a Whelen nav light that takes a W1290-14 bulb you probably wouldn't have a problem substituting a Grimes A7512-12, or a Piper 753-476. And their part numbers aren't even similar though the Piper product when in hand might turn out to be a Universal UA-7512-12, Wamco WA-7215-12 or Rapco RA7512-12. I doubt Piper would sell you a Cessna A7512-12.
I wonder if you would inquire whether most of them meet any standard or why they could be substituted. Just because they all look the same doesn't cut it. If they looked different as in the case of the LED7512-12V Spruce is selling is also not a disqualifier. Looks has nothing to do with it.

We know (or could find out maybe) they can be substituted because they all meet MS25309-7512-12, at least according to Spruce and I'll bet their manufacture. I don't think anyone has called Grimes, Wamco, Rapco, Piper or Cessna. But George has called the manufacturer of the LED7512-12V and the manufacturer has convinced George (and Spruce) that these LED bulbs meet the appropriate standard and are replacement bulbs. At least George I believe has meet a reasonable standard to which I could not find fault if he choose to use these bulbs.

I think that many people, including licensed mechanics and FAA inspectors would and will start using these LED replacements simply because Spruce is advertising them as replacements. Even though I sure Spruce could be (and have been n the past) wrong.

As for me, I'm hoping to find a lot of good used cheap MS25309-7215-12 incandescent bulbs laying around hangers as owners replace them with LED. But that is just me.

I also think that in 10-15 years when we can't buy incandescent bulbs we won't even blink replacing them with the only thing available like LEDs or gasp some newer light technology. Sort of like we know, without thought, routinely use 100LL for aircraft certified for 80.

Seven pages on this subject of changing a f-----g light bulb. I gotta hand it to the gurus. Mountains can really be made out of mole hills.

Not 'changing' the light bulb we're 'replacing' the light bulb

Otherwise, there would be a great joke in here about how many FAA reps it takes to change a lightbulb