Jerry Hey wrote:

These  Ivo prop blades cracked.  Came of a Tailwind.  This story
gets
repeated so often.  How does this company stay in business?  I know
a
few rotary guys are interested in Ivo's.  The question is Why?
Jerry

    Jerry,

      What engine was being used by the Tailwind? How many hours on
the

    Ivo? Were the blades torqued to proper value?

    Kelly Troyer

This is a failure mode of the IVO I have not seen before. These are
either
ground adjustable twist blades or they are from a variable twist
configuration.
Usually IVO blades fail when used on large displacement certified
aircraft engines
due to high peak torque pulses. That is not what happened in this
case. These
blades failed from over torque ing the twist mechanism so the blades
failed in
torsion mode. In this case it had nothing to do with the type of
engine.

It is not clear whether it was a stock amount of variable twist or
somebody
manually twisted them beyond the design limits.

Paul Lamar

The engine was an 0-320.   I will try to get the rest of the story.
Jerry

The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.