Approved and Acceptable Parts

[Big Ed]

Doing a restoration is in large part an exercise in gathering parts. The hardest part is ensuring that all parts and materials are legal. I have been thoroughly confused by internet forum explanations on what parts are legal. Surely, I wondered, the good folks at the FAA have done a summary document describing the various ways that a part can be determined eligible for installation. Turns out they have: AC 20-62E. See attached.

A quick overview:

Approved Parts

1. PMA
2. TSOA
3. TC/PC

Acceptable Parts

1. Standard Parts
2. Owner/Operator produced
3. Inspected and tested by appropriately certificated person authorized to determine conformity to FAA-approved design
4. Fabricated by appropriately rated certificate holder with quality system and consumed in repair or alteration of product
5. Commercial Parts

Acceptable parts #3 and #4 seem to be the broadest, least defined, and most gray. I think reference to the other reading materials listed in the AC would be necessary to fully understand those. If some of you with more experience can explain those and provide examples, please do.

 

[Bob Turner]

There is a lot of gray area - not well understood. Check out 14 cfr 21.8 and .9. Note that a part can be approved by someone authorized by the administrator. Neithe of these regs deal with what you can install; only with what a manufacturer can state about a part.

A fascinating study!

 

[Big Ed]

That is why AC 20-62 is useful. It was written for installers:

6.c. Conforming to Regulations. As part of determining whether installation of an article conforms with all applicable regulations, the installer should establish that the article was manufactured under a production approval pursuant to part 21, that an originally acceptable part has been maintained in accordance with part 43, or that the part is otherwise eligible for installation (i.e., has been found to conform to data approved by the FAA). This AC addresses means to help the installer make the required determinations.

The definition of Standard Parts was particularly informative to me. Now I know that all Standard Parts are manufactured to a published specification, and that those specifications are often referenced in AC 43.13-1B, Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair. Armed with that knowledge, I can research and confirm that a particular product is in fact an acceptable Standard Part for a given repair method.

 

[Bob Turner]

What will you do about your tail wheel?

Also, remember that regulations are mandatory for all of us, but advisory circulars are only binding on the feds.