Originally Posted by
Vision401
Carl O's mostly right about the sign off, but the individual DAR and FSDO may differ on 25 or 40 hours "fly off" on an certified engine. The rule was "certified engine and prop" in my first airworthy experimental. As my prop was experimental it was 40 hours. Individual DAR's can be testy. Mine wanted to see the cardboard registration not the pink flimsy which transferred ink to the registration card. I advise getting the two Advisory Circulars that spell out the process of getting an airworthiness certificate and how to test fly those "fly off" hours. One can bore circles in the air or really get to know their plane and what it can do. <snip>