REFLECTOR: Fixed pitch props, freeze plugs, and crankshaft plugs

[Dave Philipsen]

Here's a technical question for the group:  I just replaced my 
constant-speed prop with a fixed-pitch loaner prop (the MT prop is off 
for repair & overhaul).  I was told to remove the crankshaft plug (welch 
plug) and drive a freeze plug into the end of the crankshaft before 
putting the prop on.  Well, I could not get the crankshaft plug out but 
I went ahead and put the freeze plug in the end of the crankshaft.  The 
fit was perfect and very tight.  Is there any reason for me to worry 
about the crankshaft plug remaining?  I realize that there is a 
possibility oil pressure could build up against the freeze plug but I 
seriously doubt that it could be pushed out even at 100-120 psi.

Does the MT prop use oil pressure to keep it in flat pitch or does the 
oil pressure keep it in coarse pitch?  If I can fly it with the 
crankshaft plug still in, would it be advisable to pull the prop lever 
to low rpm or leave it at high rpm?

If you have an intelligent answer for this could you explain to me how 
you came to the conclusion?  I'm getting conflicting or no opinions on 
what to do.


P.S. Travis Holland is investigating this for me as well since he is the 
one who loaned me the prop.

-- 
Dave Philipsen
Velocity STD-FG
N83DP