On Thu, 30 Jun 2005 11:19:37 -0400, Kevin O'Brien
kevin@org-header-is-my-domain-name wrote:

But they have wood cores. I had thought he made all-compo ones. Guess not.

I'm not an aerodynamics engineer, or any kind of engineer, I just read
a lot and am cursed with this memory recall that can remember
portions of LOTS of stuff, but not necessarily the original source of
the recall.

I read somewhere that metal props can and do pick up certain
frequencies of vibration and can amplify the vibrations under the
right circumstances. When this happens, the vibrations can fracture a
portion of the prop blade and sometimes the entire blade.

Cutting down a metal prop can bring it into a resonant frequency that
the prop did not previously experience.

At the opposite end of the vibration spectrum is the wood prop which
actually dampens vibration.

Somewhere in the middle are composite props. Perhaps closer to the
wood end of the vibration spectrum would be the composite wood/carbon
fiber props, I'm guessing.

I did a little searching on Google about this subject and found
information that indicates Longs, Vari's, Velocities and Cozy's have
suffered a number of prop failures for a variety of reasons.

I don't have the information to know whether they suffer more prop
failures than tractor prop airplanes as a group. But having the prop
on an extension, which a number of the genre do, I would think would
make the prop more sensitive to turbulent air, regardless what it's
made of.

Corky Scott