Originally Posted by
Pilot DAR
But, a whole plane worth of parts would not be accepted without authoritative certification.
My previously fully certified FAA TCDS airplane was modified with a different engine and propeller, both fully certified at the time of installation, and installed in accordance with data provided by the original airplane designer - but it was never STC approved.
I don't quite follow your meaning with these two statements. So long as you remain within the approved aircraft specifications, to include any engine or prop changes, there is no required additional "authoritative certification" needed outside of an A&P certificate. Even an STC approval is not required since per the Part 1 definition of a major alteration states any alteration listed in an aircraft specification is not considered a major alteration. And there have been a number of engine/prop changes listed in such a manner. Regardless, the TCCA Owner Maintained category is a completely separate topic/issue way outside the OPs initial premise for the simple fact that those category aircraft no longer meet international standards and agreements and are permanently stuck in Canada unless a country elects to specifically accept them. Granted my viewpoint is strictly FAA based, but this is exactly why anyone attempting the type of work mentioned by the OP must ensure their local/national aviation authority will permit such work and provide a path to certify it with minimal restrictions..