True/False: Owners Can Fabricate Their Own Modified Parts

[Juliet Hotel]

Saw this earlier in comment on a social media post. Someone was asking about the availability of an overhead light lens or some such in different colors. One of the suggestions was he should just fabricate what he wants because 21.9(5) makes it legal for him to do so.

§21.9 Replacement and modification articles.
(a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be installed on a type-certificated product, the person may not produce that article unless it is—

(1) Produced under a type certificate;

(2) Produced under an FAA production approval;

(3) A standard part (such as a nut or bolt) manufactured in compliance with a government or established industry specification;

(4) A commercial part as defined in §21.1 of this part;

(5) Produced by an owner or operator for maintaining or altering that owner or operator's product;

That seems way too simple and my gut tells me 21.9(5) does not allow an owner to fabricate any modification he or she wishes simply because he or she is the owner of the plane. But I'm not sure why. Am I missing something in my reading of the reg? Or is there another reg that prevents what this one seems to allow? Discuss.

 

[DaleB]

I do believe it's true.

 

[sourdough44]

Are we allowed to differentiate with the actual parts? I doubt a light lens cover is a safety of flight component. Now if a person wants to whittle their own prop, it’s time for pause.

If I was in need of a new light cover, and could make one myself, no worries here. When it gets to something important, I’d give it more thought.

Now you may ask, how does one know what’s important? If one can’t figure that out, best not to do it.

 

[Cap'n Jack]

Are there other sections near the one quoted that are pertinent? I thought there's a section which limits what we could replace on a type-certificated plane. One exception that I remember allows for owner manufacture of parts that aren't produced anymore.

 

[MIFlyer]

subscribed! I'd like to see a lot more on this. As we fly older and older planes, it would be good if a lot of the parts could be owner produced where there isn't a reasonable alternative from TC holder or STC.

 

[murphey]

Not structural so the owner can fabricate.
Example....recovering seats is legal for the owner.
Physically altering the seat, such as adding a headrest, need A&P signoff.

Replacing side windows on a cherokee...yes, the owner can do this, make note in the lgbook.
Replacing the front windshield, needs A&P signoff in the logbook.

Go back to the AC 42 or 43 something for specific details.

 

[Clip4]

Just because you fabricated the part doesn’t mean a mechanic is required to install it.

 

[Timbeck2]

I wonder if that was me. I asked here if anyone knew where I could get an instrument white (which is actually blue and was an option on some Cherokees) lens instead of the red one that I had. Someone suggested I fabricate one out of plexiglass and color it blue with a magic marker or similar. A friend of mine actually found one somewhere, so now I have an instrument white lens.

 

[Juliet Hotel]

So lets say I own a 182 or something similar and I take some steel tubing and weld it up myself into a seat frame. Then I cover that seat frame myself with padding and fabric. Then I fabricate mounts and install them in the floor of the baggage compartment of my 182 along with seat belts that I make myself. Legal? Why or why not?

 

[Cap'n Jack]

So lets say I own a 182 or something similar and I take some steel tubing and weld it up myself into a seat frame. Then I cover that seat frame myself with padding and fabric. Then I fabricate mounts and install them in the floor of the baggage compartment of my 182 along with seat belts that I make myself. Legal? Why or why not?

Just my opinion, but I think the seat frame is "structural" since it has to meet some sort of rating for g-forces bearing a certain weight being dropped under certain parameters. I don't know the actual test.

 

[Checkout_my_Six]

The owner can make whatever part they want.....getting an A&P to install it is another issue.

 

[Bell206]

One of the suggestions was he should just fabricate what he wants because 21.9(5) makes it legal for him to do so.

Yes. They're defined as owner produced parts. Fabricate has a different connotation with making aircraft parts. There are specific requirements the owner must follow in order for the part to be considered owner produced, but there are basically no limits to the type of part: structural or non-structural.

However, owner produced parts should not be confused with owner/pilot performed preventative maintenance items. The former is under Part 21 and the latter is under Part 43 and are not connected in any way, shape, or form.

 

[murphey]

The owner can make whatever part they want.....getting an A&P to install it is another issue.

Sign off is the issue, installation is not always the problem.

 

[Tom-D]

The quick Reference : AC. 20-62E

Acceptable Parts. The following parts may be found to be acceptable for installation on a TC’d product:

(1) Standard parts (such as nuts and bolts) conforming to an established industry or U.S. specification.

(2) Parts produced by an owner or operator for maintaining or altering their own product and which are shown to conform to FAA-approved data.


n. Owner/Operator Produced Part. Parts that were produced by an owner/operator for installation on their own aircraft (i.e., by a certificated air carrier). An owner/operator is considered a producer of a part, if the owner participated in controlling the design, manufacture, or quality of the part. Participating in the design of the part can include supervising the manufacture of the part or providing the manufacturer with the following: the design data, the materials with which to make the part, the fabrication processes, assembly methods, or the quality control (QC) procedures.
end quote
The statement in red, says the part must conform to FAA approved data. That would be a field approval. which would require blue prints and material data.

 

[Bell206]

That would be a field approval.

FYI: no field approval is required for the part. The part approval is through Part 21 and is the owner's responsibility that the part conforms to approved data. There is no FAA involvement with owner produced parts.

 

[Tom-D]

FYI: no field approval is required for the part. The part approval is through Part 21 and is the owner's responsibility that the part conforms to approved data. There is no FAA involvement with owner produced parts.

How would you know it was FAA approved if you didn't request the approval?

 

[Doc Holliday]

How would you know it was FAA approved if you didn't request the approval?

Say what?

Where in 21.9 does it say the owner must gain FAA approval? Where does it say that in AC. 20-62E?

Do you know the difference between FAA approval and "conform to FAA approved data"?

 

[Bell206]

How would you know it was FAA approved if you didn't request the approval?

Ha. Since it still appears you have never been involved in an owner produced process from our last discussion on this topic, I'll leave you with this: a Part 43 approval process, e.g., field approval, has zero authority in a Part 21 part production process.

Paging Doc Holliday. Need another hole over here.

 

[bnt83]

Most of the owner produced parts I’m farmiliar will involve an email chain

Dear beloved OEM, we need a new ________ none are in stock anywhere, can we get a material spec to locally fabricate it?

Replays are usually some like _______ is made from __________.

Or

“Pound sand” order one and wait.

Depending on how they want to look is usually the reply. If they want to support their product and look good, they’ll help. If not, third party engineering may be the next move

 

[Bell206]

can we get a material spec

third party engineering may be the next move

You can also get the original part tested and reverse engineer the item in some cases. Most full service machine shops can provide the testing with results in writing. There was a run on certain Cessna flap tracks as OPP items back when someone posted results of a material spec test on line by track P/N. Even with certain complex formed aluminum cowl/fairing pieces you can identify the base material through the SRM or testing (usually 2024-T3) then hand form/cold work some 2024-O into the same shape then send it out for a T3 heat treatment. With todays 3D printing capabilities it will be interesting if some owners follow that path.

 

[weirdjim]

21.303 (b)(2).

Jim

 

[Cap'n Jack]

21.303 (b)(2).

Jim

Why do you feel 14 CFR § 21.303 applies here?

 

[charlie]

Talk about owner produced parts brings to mind a Comanche that we installed our overhauled engine on and for weeks I could not figure out what was "funny" about it. Finally realized that it had side windows made out of flat plexiglass. I don't remember if I test flew ir but it had to be noisy!

 

[weirdjim]

Why do you feel 14 CFR § 21.303 applies here?

Did you bother to read it?

Do you have the Office of General Counsel's written opinion as to the implementation of this exact section?

Jim


Sec. 21.303 — Replacement and modification parts.
(a) Except as provided in paragraph (b) of this section, no person may produce a modification or replacement part for sale for installation on a type certificated product unless it is produced pursuant to a Parts Manufacturer Approval issued under this subpart.


(b) This section does not apply to the following:

(1) Parts produced under a type or production certificate.

(2) Parts produced by an owner or operator for maintaining or altering his own product.

(3) Parts produced under an FAA Technical Standard Order.

(4) Standard parts (such as bolts and nuts) conforming to established industry or U.S. specifications.

 

[Cap'n Jack]

Did you bother to read it?

Do you have the Office of General Counsel's written opinion as to the implementation of this exact section?

Jim

Yes, I did, but I wanted to hear your thoughts about it. The link I found doesn't seem pertinent. https://www.law.cornell.edu/cfr/text/14/21.303

Sec. 21.303 — Replacement and modification parts.
(a) Except as provided in paragraph (b) of this section, no person may produce a modification or replacement part for sale for installation on a type certificated product unless it is produced pursuant to a Parts Manufacturer Approval issued under this subpart.


(b) This section does not apply to the following:

(1) Parts produced under a type or production certificate.

(2) Parts produced by an owner or operator for maintaining or altering his own product.

(3) Parts produced under an FAA Technical Standard Order.

(4) Standard parts (such as bolts and nuts) conforming to established industry or U.S. specifications.

This seems different from the information I found. However, this seems in line with the original poster's interpretation.

BTW- did you get the PM I sent about one of your articles?

 

[Bell206]

Sec. 21.303

FYI: outdated reference. 21.303 now covers PMA parts. Current is 21.9.
https://www.ecfr.gov/cgi-bin/text-i...dc29bd13b1&mc=true&node=se14.1.21_19&rgn=div8

 

[alfadog]

Owner to A&P, "my engine mount is corroded but no worries, I just welded up this one in the garage..."

 

[mondtster]

I'm a bit confused by the original post. Are we discussing modifications to an aircraft here or owner produced replacement parts?

 

[SkyDog58]

Sometimes, POA threads make my head hurt.

 

[Dana]

(2) Parts produced by an owner or operator for maintaining or altering his own product.

But what does "his own product" mean?

 

[Tom-D]

Paging Doc Holliday. Need another hole over here.

Yep! you need reinforcements.

FAA-approved data. would be a manufacturers blue print or such, anything else would require approval.

Reverse engineering? what a laugh, seldom is it approved, due to the lack of data of the original.

The easy way around this whole issue is simply do a repair.

 

[Cap'n Jack]

But what does "his own product" mean?

Dana-
I'm sorry, I messed up the quote. The person who should respond is @weirdjim since he actually brought this section into the thread.

I can parse that sentence you asked about in a couple of different ways. Since few people manufacture their own type certificated planes, I took it to mean parts made by a person for maintaining or altering an aircraft that was purchased and is now in their possession.

 

[Tom-D]

Ha. Since it still appears you have never been involved in an owner produced process from our last discussion on this topic

Just so's ya know I've building parts for antique, and certified aircraft sense before you were born. never once has the FAA had a problem with what I do.

 

[weirdjim]

But what does "his own product" mean?

As I said, the FAA General Counsel's opinion deals with that directly. I've got a copy around here somewhere. I'll see if I can post a link, or failing that, I'll simply paste the whole damned thing in this ng. Summarizing, the FAA meant to say "aircraft" and some junior lawyer changed it to "product" in the final approval process.

Just FYI, I built a 45 year old company on this wrinkle in the regs, and have had several "friendly" visits from the feds and as yet, I'm still in business. RST Engineering started out building audio panel KITS, graduated to nav receivers, 720 channel navcoms, and as yet, haven't had a problem with the quoted section. Somewhere in all that time I have (or had) north of 10,000 of my designs and my customer's carefully constructed KITS flying in both standard and experimental categories.

Jim

 

[weirdjim]

Owner to A&P, "my engine mount is corroded but no worries, I just welded up this one in the garage..."

And as an A&P for nearly 50 years, if I knew the welder was an expert, could convince me that he used the same alloy steel, same diameter, same dimensions, I'd be inclined to sign it off.

Jim

 

[mondtster]

And as an A&P for nearly 50 years, if I knew the welder was an expert, could convince me that he used the same alloy steel, same diameter, same dimensions, I'd be inclined to sign it off.

I agree 100%, and I have done this in the past. But the owner and I worked together to establish what the proper repair procedure would be.

Unfortunately, my experience has been that the owners who want to go about repairing things the right way are few and far between, so Alfadog has a valid point as well.

 

[alfadog]

And as an A&P for nearly 50 years, if I knew the welder was an expert, could convince me that he used the same alloy steel, same diameter, same dimensions, I'd be inclined to sign it off.

Jim

I would want the welds x-ray'd but I am with you on that. How would you word the logbook entry?

 

[Lachlan]

But what does "his own product" mean?

What if a girl owns the airplane?

 

[mondtster]

I would want the welds x-ray'd but I am with you on that. How would you word the logbook entry?

Minor nit, but it's going to require a 337.

 

[Tom-D]

I would want the welds x-ray'd but I am with you on that. How would you word the logbook entry?

Pretty much the same verbiage as block 8 on the 337.