Posted for "Lancair" <lancair@USTEK.COM>:

From: Lancair Mailing List on behalf of Walter Atkinson
 Subject: [LML] Re: Backfires LOP
 I am unfamiliar with any science that supports that set of notions.
 I've got to ponder that.  'Tis a puzzlement.
 
 Walter,
 
 This was a just history of observations and it seems to agree with your
notion that the sound comes from an afterfire.  After test flying several
hundred aircraft under a range of conditions the pilot has encountered the
same problem that several other (TS)IO550 drivers have encountered - the
occassional POP while running very well leaned.  What aspect is puzzleing?  Is
it that he has encountered it more with lightweight props?
 
 Robert M. Simon
 ES-P N301ES