For repairs, the repair manual or 8083 calls for specific parts - sometimes down to what rivets must be used.
Repair manuals and handbooks are merely acceptable data and are only considered recommendations unless the repair manual itself is specifically approved. In the case of the 430 I believe the Garmin mx manual covers this work.
The FARs also dictate who and what can be used for repairs in instruments. I’m seeking to learn how an instrument can be opened up outside of an instrument repair station (not even an A&P can do that) and a non certified e bay replacement screen assembly can be installed.
The Part 1.1 instrument definition does not show all electronic devices as instruments. So, as I mentioned above, it’s the same manner which Ed repaired KX-155s and the person installing them signed the approval for RTS. But if the 430 was considered an instrument, then yes, you would be correct. See below for the part side.
I understand hangar ferries exist, and more than likely aircraft don’t spontaneously combust after they do their work.
No. But if you as certified mechanic were to sign a 100hr inspection or perform work in the same area a hangar fairy does their thing, and their work fails requiring the local FSDO to investigate, since your name was in the book last, you will assume the responsibility of their fairy work.
But not sure how all of this could be “by the book”.
Simply because “the book” does not cover all possible maintenance tasks and Part 43.13 is written to give you as a mechanic the work around for that limitation. For example, some aircraft do not have maintenance manuals, so how would you perform and sign off mx on those aircraft?
Hummm. You’re using a non certified part made by someone else (not Garmin) making a change to a certified instrument. Seems like the part needs a PMA and the soon to be different GNC needed an STC installation instruction as well as need to file a 337.
When fixing any item, it usually falls under 3 main categories: repair, alteration, or part replacement. And in general terms, a repair returns the item back to its original design specifications; an alteration changes the item from its original design to a different design; and a part replacement involves replacing an item with a new part that meets the original design.
So with this 430 they repaired the unit by replacing the screen. However, 10-1 that screen was not OEM, so the screen itself would be a minor alteration under the repair. And not all parts are approved either. Some fall under Standard Parts, COTS, etc. and are still eligible to be installed on aircraft. If that makes sense.
And a PMA is there for people to sell those parts to the public or to use under part replacement mx; an STC is for the major change to type design approval for the entire system and is not applicable to the 430 repair; and, a 337 is only needed if the 430 repair was considered a major, which if you check Part 43 Appx A(b)(4), you’ll note screen replacement does not fall under those major repair categories.
Can I replace my mags with an Amazon bought non certified electronic ignition system with no STC, 337, etc?
Yes, but not without approved data entered on a 337, as that would be considered a major alteration. Now whether that major alteration rose to the level of a major change to type design, requiring an STC, that would be up to the regulatory person you discussed it with. However, you can install any other amazon bought items as a minor alteration and your mechanic signature all day long.
