Quote Originally Posted by FLATS ONLY View Post
They were not all failure of material. Installing propellers & making correct keys for each prop is what's important. Installing the propeller correctly is where it's at.
That makes a lot of sense. Where parts join and torque is transferred can easily become failure points. Improper fit would just increase those stresses.

The keyway concern was discussed but may be hard to find until HB cleans the thread up.