Rules on fabrication of airframe parts for EASA-reg and N-reg?

Silvaire
I went back into records and dug the internet and found the reason for the confusion (well, I think so).

21-303 (2) says:
“Parts produced by an owner or operator for maintaining or altering his own product”.

“The meaning of the second exception, “owner-produced parts” was rather murky until April 5, 1993, when Donald P. Byrne, the FAA’s Assistant Chief Counsel for Regulations, issued a memorandum defining the term ‘owner (or operator) produced part’ as used in FAR 21.303 (b)(2). Byrne’s memo clarifies the FAA’s interpretation of the owner-produced parts exception, and as you’ll see, that interpretation is surprisingly generous and liberal.

The Assistant Chief Counsel explained that it is not necessary for the owner to actually manufacture the part himself in order for the part to be considered an “owner-produced part.” The owner may contract with a mechanic, a repair station, or even a non-certificated individual or firm (e.g., a machine shop) to manufacture the part for him, provided that the owner “participated in controlling the design, manufacture or quality of the part.” Byrne went on to explain that the FAA would deem the part to be owner-produced if the owner:

1. Provides the manufacturer with design or performance data from which to manufacture the part. This test would be met if the owner
provides the manufacturer with the old part and asks that it be duplicated; or
2. provides materials to make the part; or
3. provides fabrication processes or assembly methods to be used in making the part; or
4. provides quality control procedures to be used in making the part; or
5. supervises the manufacture of the part."

You can see that (1) of the above requires that the part is being duplicated i.e identical while the FAR is using the word ‘altering’. Yet, my problems are not over.

During the searches I logged into the US Government Publishing Office site and searched for FAR 21-303 (http://www.ecfr.gov/cgi-bin/text-idx?rgn=div5;node=14%3A1.0.1.3.9 ) as I always like to see the official version, there is no mention of Owner Produced Parts. Other, non official sites (see Adam’s link) still publish the FAR as I know it to be.

So the question is what have changed? The FARs or the Owners Produced Parts were moved else where?

Ben

I keep hearing it differently from different (seemingly qualified) sources… and must make the effort to clarify this: some sources say ‘same or better’ is required for repair materials by FAA, other sources say materials exactly as originally certified is the requirement. I suspect the difference may have something to do with owner produced versus PMA, but again I do not know.

You can’t change the resistor’s value but if you use a resistor containing material X instead of Y and it is known that X has better life span or is more stable then Y then you have used a better part. At least this is what I made of the rules.

Peter wrote:

It’s actually an interesting discussion whether one could use this concession for repairing autopilot servos, to solve the KFC225 “smoking servo” issue. I think the answer is NO but only because only an idiot would repair the servo without changing the incorrect components which enable the meltdowns to happen, and if you do that, the part is no longer identical to the original…

Years ago I was in such a situation (not A.P) and was looking to produce my own part as a repair is not permitted (at the end an FAA inspector told me where I can find the part). The FAA rules (as Adam said) allow you to produce the part using the same or BETTER spec’ed. parts so if you can show that the parts that you were using are better than the original you are legal. However, and this is a big however, the liability remains with you even if the aircraft was sold several times. For that reason I would think many times before having any owner produced part on an aircraft.

I am a great fan of fabricating parts and repairing aircraft but the problem with fabricating parts is twofold.

Technical data, getting this from manufactures is probalamatical and I suspect SOCATA deliberately don’t publish it, Cessna do and have a very good chapter in the manual to cover most issues. Robin are even better all they have is a few restrictions ( not prohibiton ) on repair in critical areas and say do anything else in accordance with AC43.

Cost. Fabrication may be technically posable but due to the way the item is constructed the cost of labour, jigs & fixtures pushes the price for the fabrication of one item above the cost of buying the thing, if you can get a group together for a small production run you could probably make it pay ( the Bulldog fatigue issue comes to mind ).

I repaired a Cessna rudder a year of two back and the cost of doing so in the UK was about the same ( when the shipping was included ) as getting an exchange rudder from the USA the only advantage was the labour content of the work stayed in house.

Peter – with regards to gear leg certification, companies like LASAR managed to do it for the Mooney; see this product for instance

http://www.lasar.com/parts/w/id/4/part_details.asp

That does indeed seem the exact sort of repair that should be conducted, but with an EASA registered aircraft and CS-STAN not in place just yet, what is the legality of doing such a repair?

NIL: Without seeing the actual damage, I would first and foremost consider a patch and/or doulber type repair. Seems this is fast becoming a lost art, but there is NO practical reason not to implement a repair.

Not sure about Socata, but, all of the big 3 GA makers give detailed information on patches, rib and stringer repairs and even main spars. Further, AC43.13 gives plenty of “data” for such repairs, more than enough to cover the regulatory needs for this.

CS-STAN looks great, but with it moving at EASA/EU pace, it looks like it won’t be in place for another 6-9 months yet. What about any repairs needed in the meantime on European registered aircraft that would happily fall under AC43-13 if the aircraft were on the N register?