On 7 February 2014 00:31, Dj Merrill <deej at deej.net> wrote: > The prop rule is interesting, too. LSA specs say you can have a ground > adjustable prop, but not one that can be adjusted in the air. Can you > put an electrically adjustable prop on an LSA aircraft and placard the > panel switch "Adjust prop pitch only on ground"? :-) > > In Oz recently a bunch of LSAs with in flight adjustable props were grounded because the LSA rules didn't allow for an in-flight adjustable prop. Turns out the reason was because the LSAs were manufacturer certified against the ASTM standards (LSA manufacturers can decide which standards they self certify to - most choose ASTM), and there was no ASTM standard for in flight adjustable props. Therefore fitting such a prop was inconsistent with the standards against which the aircraft was certified and that in turn invalidated the aircraft's Special Certificate of Airworthiness.
Rather than take this lying down (and retro-fit fixed or ground adjustable props) one of the LSA importers decided to approach ASTM to develop a standard for in flight adjustable props. A number of manufacturers backed him up and that standard was ratified at Oshkosh last year. So now inflight adjustable props can be used on LSAs, so long as the manufacturer says it's OK (just like any other change to a factory built LSA). At least that's the situation in Oz. Cheers, Tony
