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