<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=US-ASCII">
<META content="MSHTML 6.00.2900.2722" name=GENERATOR></HEAD>
<BODY id=role_body style="FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY: Arial"
bottomMargin=7 leftMargin=7 topMargin=7 rightMargin=7><FONT id=role_document
face=Arial color=#000000 size=2>
<DIV>In a message dated 8/16/2005 12:51:26 AM Eastern Standard Time,
DaveL322@comcast.net writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2><FONT
face=Arial size=2>With the 2 failures on 2Cs (both well used props from the
original mold), I'm personally going to limit the number of flights I put on a
given prop and retire some of my old ones. Perhaps my thinking is
flawed or too aggressive, but I don't think it unreasonable that a high
performance prop in a high performance application has a limited life
expectancy. <BR><BR>Regards,<BR><BR>Dave
Lockhart</FONT></FONT></BLOCKQUOTE>
<DIV> </DIV>
<DIV>I agree with that. The prop that I had fail was an old prop with many
flights. It was used as a test prop and flown on many different setups before
and after Dave repitched it. I really liked the prop and want another. Dave, you
got one handy?</DIV>
<DIV> </DIV>
<DIV>I want to take this opertunity to say that I don't blame APC or Dave for
the failure. </DIV>
<DIV> </DIV>
<DIV>My memory may not be as good as I want it to be, but I think it was Brian
Hebert and Todd Blose that I was telling about the failure while at the Nats.
They told me they had seen a couple of failures on some 2 blades also. The
common thread was that they were old props. Todd and Brian had already made
the decision to replace their props on an annual basis.</DIV>
<DIV> </DIV>
<DIV>After much thought, I am now of the opinion that many of us (including
myself ) have a tendency to tighten the props too much when we put them on our
engines. In the past, I have seen people tighten them so much that it was a real
bear to remove the propnut. Over tightening them has got to have a crushing
effect on the hub. Over the life of the plane the prop is on, it can be removed
and replaced many times for maintenance or engine changes. It is not
unreasonable to believe that each time the hub is tightened down and then later
removed, a cycle has occured where the fibers and resin of the prop have been
squeezed and relaxed. Over time this could lead to small cracks that may not be
visible that are inside the hub. At this point, failure is only a matter of
time. </DIV>
<DIV> </DIV>
<DIV>Robert Gainey </DIV></FONT></BODY></HTML>