Original Posted By: Doug Dever
Subject: Pietenpol-List: test flight hours 40 or 25? I found this information on the RV list and have given credit highlighted in yellowto the appropriate authors. I hope this helps.Mike C.This is out of AC20-27E, CERTIFICATION AND OPERATION OF AMATEUR-BUILT AIRCRAFT:a. Amateur-built aircraft will initially be limited to operation within an assigned flight test area for aminimum of 25 hours when a type certificated (FAA-approved) engine/propeller combination is installed, or 40hours when a non-type certificated engine/propeller combination is installed.I would take this to mean a engine/propellor combination that has been FAA certified for use on other aircraft (other than experimental). When you put an uncertified prop, IE a Catto, it becomes an uncertified combination, thus a 40 hour test period.Other comments?Bill WatersIf your engine has a data plate from Lycoming on it and your prop is certified for that particular Lycoming model, then you will get 25 hours. Anything else gets you 40 hours. You will have to show the inspector the certification sheet for the prop to prove to him it is a certified combination.Now, if you pull that Lycoming off your experimental and try to sell it, it cannot go into a certified airplane again unless it is completely remanufactured (not rebuilt) by a certified engine shop. It has to do with the fact that on a certified engine, the parts from the same engine stay with the engine until they get replaced. When it's remanufactured, it's a new engine again and it comes with a new logbook. On an experimental engine, parts from different engines can be mixed and matched as long as they are within tolerances for a rebuilt or a remanufacture. That's why Aero Sport Power engines come with a new data plate that identify it as a "Aero Sport Power O-360" instead of a Lycoming.However, the Feds do make mistakes. I got only 25 hours on my RV-6 because the inspector failed to notice that the engine was from Bart instead of from Lycoming. My Sensenich metal prop was certified for my O-320 so he only gave me 25.For a simple, VFR airplane, 25 hours of testing is usually enough. But I almost prefer the regime of a 40 hour test period because you really need it to do flight testing properly on a more complicated airplane, just my $.02.__________________Randy Pflanzer________________________________________________________________________________