Originally Posted by
WLIU
As for composite props, we are talking about two different stresses that will cause the engine to fail. A composite prop puts less load on the crankshaft flange. That is good. But the torsional resonance issues will destroy the engine components on the other end of the crank. In both cases you will find yourself looking at a landing off the airport. I have a friend who ran into this and the engine rebuild was very costly. The engine only flew with the inappropriate lightweight prop for 50 hours or so. The problem was fortunately identified on the ground. A lot of expensive internal parts went into the trash that are normally inspected and reused in an overhaul. An issue that it is not wise to ignore.