Bill, most props for non-turbine applications don't exactly go to feather...
They are usually called "counterweighted" props and the counterweight use
centrifugal force to move the blades to a "course pitch", but not full
feather.  A specific governor is required with these type of props... A
"standard" governor won't work with them (at least as it relates to letting
the blades move on loss of oil pressure.

I think it's Hartzel that has a pretty good description on all of this on
their website.  NOTE, the counterweighted prop is *lots* more money than a
non-counterweighted one and will require a special spinner so the spinner
clears the counterweights.

Hope some of this is helpful.

Alan

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Bill
Wade
Sent: Tuesday, October 16, 2007 3:06 PM
To: lml@lancaironline.net
Subject: [LML] Re: prop drag


  My ignorance is showing but from what I've read if you have a
non-feathering prop the blades will go to flat pitch if oil pressure is
lost. I haven't experimented to find a value but once RPM drops below a
certain point (as in throttled back for landing) the governor becomes
ineffective, does it not?

  If the prop wasn't windmilling it should go to flat pitch. If it was
turning would the speed be sufficient to allow pitch change or would it also
be at flat pitch?

 I'm considering a feathering prop but I've never used one. What happens at
startup and low RPM's- is there a control detent to prevent the prop from
going feathered?  -Bill Wade

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