Why do people call Condition Inspections " Annuals"

[Sam Buchanan]

Did that change at some point? I haven't paid attention recently, but I thought at one time there was a reduced test time with a certificated engine... which carried the requirement for the engine to stay certificated, meaning an A&P to work on it (as always, anybody could work on the rest of the plane). As I understood or recall it, you could stop treating the engine as certificated by putting the plane back into phase 1 testing again for some number of hours. But I could have misunderstood it then or misrecall it now.

A certificated prop in combination with a certificated engine can indeed result in a 25 hr Phase 1 instead of 50 hr. But maintenance requirements are the same regardless of the ancestry of the prop and engine. As I recall this has been the case since I have been in the experimental community (~25 years).

An engine cannot "stay certificated" in an aircraft with an experimental airworthiness certificate. Certification requires a particular engine/prop combination in the same airframe in which certification was achieved. In other words, in a type certificated airframe.

But experimentals don't have type certificates. Consequently, it is impossible to have a "certificated" engine in an experimental. Having said that, it is possible to maintain an engine and prop to the same standards as it would have been maintained in a type certificated airframe, but the engine is no longer "certificated".

I've heard builders say they want to "keep their engine certified" so it can be later sold (at a higher price) and installed in a certificated aircraft. Even though the engine may have been maintained to a high level, it would most likely be very difficult to find an A&P/IA to install the engine and endorse the logs without a complete teardown to insure it still meets certification standards. So the intended advantage really doesn't exist.