> 
 >     Master airscrew don't seem to hold their pitch well.  I get a very 
 > marked
 > increase in speed and thrust with APC.  I tend to be able to go up a full
 > inch
 > in pitch with no loss in RPM.
 > 
 >     If you look at the edge of a master airscrew while under power you wi
 > notice that the blades are not tracking in the same plane.  Don't look to
 > close, you might get a face full of blade.  The inaccurate tracking shows
 > that
 > the blades are not producing the same thrust, or one blade is stiffer. 
 > 
There is more to it than that.  Have you ever placed the prop on a pitch 
guage?  The pitch between the two blades could be inconsistant.  Or the prop
hub may not be square and/or the hole may not be a perfect 90 degrees to the
hub.  Lots of possibilities because these props ARE molded and as such they 
have a curing process and who knows if the exact same amount of resin is in 
both blades.  Or perhaps they were popped from the mold too early or the 
humidity or temp had changed.  Lots of possibilities that could affect any 
of the "plastic" props.  
Bottom line is, regardless what kind of prop you use.  It falls to the owner
to make sure the prop is true, balanced, safe and proper for the application
involved.  I'd venture to say that on any given day, at any given flying 
field, as much and perhaps even more than 50% of the props in use were 
either never balanced, or checked and declared "Close enough".  And that 
many of those that had been balanced have never been re-checked since being 
used and would not now be as balanced as they once were.
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 * QReader 1.10 * UNREGISTERED EVALUATION VERSION
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