wrote in message
ups.com...
I'm wondering if fitting turbine engines on the old airframes
didn't pull something loose in the wing/mount.

Turbines run a whole lot smoother than the round Pratts that were on
originally. They don't have the power pulses that radial engines have.

I assume he was referring to the increased thrust that was probably obtained
with the turbine installation, which would create higher forces on the
structure transmitting that thrust to the airframe.

Of course, one would think that in a turbine retro-fit, that structure would
be upgraded to compensate. Hopefully, that's not actually the problem.

But I don't think Otis was suggesting that turbines would cause more fatigue
due to vibration than the original engines.

Pete