OK, but what is the meaning of “PMA” if only you make it and only you ever made it?
Maybe the term is used in a different context: non TSO parts approved by the aircraft mfg’s TC. That is an incredibly hard process. By “PMA” I meant some small company making a PMA replica of an existing part, which is the standard meaning of “PMA”. I was hoping that was obvious 
https://www.faa.gov/documentLibrary/media/Order/8110.42C.pdf
5. Who Needs A PMA?
a. General Requirements. Title 14 of the Code of Federal Regulations
(14 CFR) § 21.303(a) requires any person producing replacement or modification parts for sale
for installation on a type-certificated product to get a PMA. A PMA is a combined design and
production approval for replacement parts. Also we may use a PMA for the production of
modification parts from supplemental type certificates (STC). The prior STC approves the
design and installation of these modification parts in products. However, if any replacement part
alters a product by introducing a major change, then 14 CFR § 21.113 requires an STC for the
approval of these parts.
So an avionics mfg can take a previous product of theirs which has an STC, and they can sell a slightly modded version of it under a PMA.
It seems an unusual use for a PMA, but interesting…
Peter wrote:
So an avionics mfg can take a previous product of theirs which has an STC, and they can sell a slightly modded version of it under a PMA.It seems an unusual use for a PMA, but interesting…
Not quite. The manufacturer designs a product as a prototype, works with the FAA to get an STC on a given aircraft type (or maybe an AML, but this still requires a trial installation on a specific airframe with all of the associated certification flight testing). The STC approves the design of the part and its integration into a certified aircraft. The part then is granted PMA, allowing it to be manufactured.
wigglyamp wrote:
Not quite. The manufacturer designs a product as a prototype, works with the FAA to get an STC on a given aircraft type (or maybe an AML, but this still requires a trial installation on a specific airframe with all of the associated certification flight testing). The STC approves the design of the part and its integration into a certified aircraft. The part then is granted PMA, allowing it to be manufactured.
What’s the difference with TSO/ETSO?
arj1 wrote:
What’s the difference with TSO/ETSO?
There are products out there for which there are no TSOs. Or in Garmin’s case with the G3X components, they were initially designed for the Experimental market and are not compliant with TSOs (they don’t meet DO-178/254 software/hardware) requirements. Approving them via an STC under an alternative certification process and then produced under PMA gets around the TSO issue (and hopefully makes them cheaper for all of us!).
Dynon do the same with their certified EFIS:
https://www.dynonavionics.com/includes/literature/Certified-brochure.pdf
Is SkyView HDX for certified aircraft TSO’d and/or PMA’d?
The design and installation approval for SkyView HDX are both
covered by the STC. There are no TSO approvals needed. Dynon
Certified products are produced under PMA.
For examples of other Non-TSO’d products under PMA, these are some I’ve used in Bizjets:
https://fdsavionics.com/support/faa-pma-approved-products/
Right, so if I understand this correctly then it looks like:
- experimental avionics are produced
- avionics installed in certified a/c for testing and appoval via the PMA process.
Is that correct?
I mean it is either a TSO process is too taxing or the PMA is not rigorous enough. :)
This is a side discussion however, of a fairly obscure use of PMA by somebody in-house.
The vast majority of PMA parts are made by somebody other than the original mfg. We in GA use a vast array of PMA parts. Air filters, spark plugs, oil filters, ignition leads, internal engine parts (Superior being PMA of Lycoming, etc) and loads of bits like that.
EASA doesn’t like FAA-PMA and has no equivalent regime, and has threatened to block FAA-PMA, but if people could not use FAA-PMA, EASA-reg would grind to a halt.
