Nav light replacement bulb

[EricJ]

35 minutes ago, Steve W said:

The very very old AC 20-74 does talk about how color is measured. Basically where it falls on the CIE Chromacity Diagram. Not sure how much a meter would cost these days, a non-certified meter looks to be about $300... Of course if we're talking about standard parts then the manufacturer of the emitter should be able to provide the necessary data. Probably something like this: http://www.nichia.co.jp/en/product/led_color.html

Which leads to an interesting question. Can I produce/have produced an LED bulb under owner produced parts? If I take the FAA specs to my local LED bulb maker and ask them to meet the following specs using these emitters, and test it after for proper color and brightness, does that make it legal? 

 

 As long as it meets all the requirements for an owner-produced part, that's totally legit.   Some guidance here:

https://www.faa.gov/documentlibrary/media/advisory_circular/ac 20-62e.pdf

and distilled a bit better here:

https://www.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-08_owner-produced-parts.pdf

 

[Bob E]

EricJ and Cliffy, I'm not an engineer but I'd sure like to hear your responses to my questions above -- the ones about Whelan claiming TSO under C30b, a standard that no longer applies, and the three questions I asked right after that regarding TSO C30c, why incandescent position light bulbs aren't marked "TSO," and why I can't just replace a 7512-12 bulb with a 7512-12 bulb. 

I'm interested in this thread, but I can't believe aircraft owners need to have an engineering degree just to replace a light bulb.  I'm perfectly happy to rely on my IA as well as the article in the October 2019 AOPA Pilot magazine.

Maybe the real question is:  "How many MooneySpace members does it take to change a light bulb?" 

[Hank]

3 hours ago, Bob E said:

"How many MooneySpace members does it take to change a light bulb?" 

Just one to change the bulb, but all the rest to debate whether the owner can change it, what bulb he must use, how the bulb needs to be made, who can supply the bulb and whether or not the bulb used is legal. Just like the actual bulb exchange takes only a few minutes, while the debate can rage for years . . . . .  

[EricJ]

13 hours ago, Bob E said:

EricJ and Cliffy, I'm not an engineer but I'd sure like to hear your responses to my questions above -- the ones about Whelan claiming TSO under C30b, a standard that no longer applies, and the three questions I asked right after that regarding TSO C30c, why incandescent position light bulbs aren't marked "TSO," and why I can't just replace a 7512-12 bulb with a 7512-12 bulb. 

I'm interested in this thread, but I can't believe aircraft owners need to have an engineering degree just to replace a light bulb.  I'm perfectly happy to rely on my IA as well as the article in the October 2019 AOPA Pilot magazine.

Maybe the real question is:  "How many MooneySpace members does it take to change a light bulb?" 

I tried to answer those above already, actually.   It's a good question why Whelen has that literature like that, since those part numbers don't appear in the TSO list on faa.gov in either TSO-C30b or C30c.   I don't know why bulbs might or might not be marked TSO in practice, but I have to admit I've seen some marked "PMA".   And AFAIK there's nothing stopping an owner from replacing a 7512-12 bulb with another 7512-12 bulb for a Part 91 airplane.    That's just my opinion, clearly there are others that agree and some that disagree.

I agree that this stuff gets stretched pretty thin in interpretation, but to me all sides of the argument are understandable.   The FAA has put out plenty of documentation and said and done enough different things that you can take different positions and have documentation to back it up.  There's definitely a document trail that says nothing that the Pope hasn't kissed can go on the airplane, and then there's clearly owner produced parts, where a professional dancer or a fish biologist can make their own part and legally put it on their airplane.   I don't personally think that only those two extremes exist or that the folks at the FAA think that only those extremes should exist.   There's an AC, that I don't have in front of me right now, that pretty much says owners are just supposed to use good judgement.  So there's that, too. 

Edit:  I was thinking of AC 43-12A Chg 1, which is intended to help clarify what "Preventive Maintenance" is.  It includes the statement: "Owners and pilots must use good judgment when determining if a specific function should be classified as preventive maintenance."  

Edited September 23, 2019 by EricJ

[Bob E]

Thanks much, EricJ -  much appreciated!

The whole bulb debate may seem a bit absurd, but it's actually a fascinating dive into the arcane world of specs and standards that lurks behind the Part 91 stuff that us mere owner-pilots try to comply with.  I'm an attorney and I'm used to in-depth research, but the amount of historical and current data / information you guys on this forum come up with is truly impressive.

[cliffy]

Some of us over a career actually stayed up nights reading that arcane dry literature for fun. Some of us had no life when we did it :-)

I actually read the entire GPS TSO document several years ago - TWICE!  :-)  Dry as a popcorn fart. 

[Hank]

11 minutes ago, cliffy said:

I actually read the entire GPS TSO document several years ago - TWICE!  :-)  Dry as a popcorn fart. 

I'm sorry!

I'd rather read an encyclopedia, at least I'd probably learn a few things . . . .

[cliffy]

As a kid I used to read the encyclopedia   (actually learned how to spell it from a Jimmy Cricket song).

Go look that one up :-)

Here, I'll help you out-  (now back to our regular program)

 

[philiplane]

On 9/22/2019 at 9:13 PM, EricJ said:

 As long as it meets all the requirements for an owner-produced part, that's totally legit.   Some guidance here:

https://www.faa.gov/documentlibrary/media/advisory_circular/ac 20-62e.pdf

and distilled a bit better here:

https://www.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-08_owner-produced-parts.pdf

 

You're missing the main purpose of the owner produced part exemption. It is NOT for modifications, it is for duplication of no longer available parts. If you can buy a replacement part off the shelf, no matter how costly, you don't need to produce one, right?

[EricJ]

14 minutes ago, philiplane said:

You're missing the main purpose of the owner produced part exemption. It is NOT for modifications, it is for duplication of no longer available parts. If you can buy a replacement part off the shelf, no matter how costly, you don't need to produce one, right?

Is there an exclusion to the rule if the part is available?   I'm not aware of that wording anywhere. 

 

[jaylw314]

2 hours ago, philiplane said:

You're missing the main purpose of the owner produced part exemption. It is NOT for modifications, it is for duplication of no longer available parts. If you can buy a replacement part off the shelf, no matter how costly, you don't need to produce one, right?

That might be the spirt but is not the letter of the regulation.  In the EAA article cited above, Mike Busch refers to a battery box which is still available being done as an owner-produced part.

[DonMuncy]

An owner can "produce" any part on his plane if he can meet the requirements for his participation in the production (actually fairly easy). BUT, the A&P installing the part has to be Ok with its installation.

[EricJ]

Cost and lead time affect availability as well.   Presentations made and released by the FAA also cite excessive lead time, six months in their example, as rationale for an owner producing a part.

So, yeah, "availability" is in the eye of the beholder, and any owner can produce a part if they so desire, for any reason.

[Raptor05121]

On 9/18/2019 at 12:04 PM, jaylw314 said:

That is incorrect, I believe position lights and anticollision beacons are TSO'd.  Landing lights and (I think) strobe lights are not.  That is why most people don't think twice about swapping out landing lights for LED's, but there is at least some more controversy about position lights and anticollision beacons.

Also, FWIW, I don't think any of Part 23 applies to Mooney's, they were certified under CAR 4 and still are AFAIK

 

On 9/18/2019 at 1:56 PM, Hank said:

CAR 3

I tl;dr'ed the entire thread and this is my $0.02:

A few weeks ago I traveled to Orlando to meet with two FAA inspectors for a medical flight test. One of them was a IA and was performing a "ramp and records" check on the aircraft and logbooks. At the end of the test, I asked them specifically what the FAA's view on non-TSO, drop-in LEDs are for airplanes and I am loosely quoting: "as long as there is no modification and drops in, its fine".

Keep in mind, that is ONE quote from one inspector from ONE FSDO. I know other inspectors may ramp and ground a plane for the same thing but AFAIK, the Orlando FSDO is fine with it.

Do with this information as you may.

[ArtVandelay]

I tl;dr'ed the entire thread and this is my $0.02:

A few weeks ago I traveled to Orlando to meet with two FAA inspectors for a medical flight test. One of them was a IA and was performing a "ramp and records" check on the aircraft and logbooks. At the end of the test, I asked them specifically what the FAA's view on non-TSO, drop-in LEDs are for airplanes and I am loosely quoting: "as long as there is no modification and drops in, its fine".

Keep in mind, that is ONE quote from one inspector from ONE FSDO. I know other inspectors may ramp and ground a plane for the same thing but AFAIK, the Orlando FSDO is fine with it.

Do with this information as you may.

I would think navigation lights would have a brightness requirement, I know boat navigation lights do. Strobes as well. But taxi, recognition lights, wing icing lights, etc they should not care. Not sure about landing lights.


Tom