The blades, being held by only two bolts each, can move (or
swing) chordwise in the hub......
Even with those bolts torqued to spec we had blade movement between the
plates. Fretting was evident on the blade bushings and mating plate
surfaces. Scared us.



When ground testing my auto engine with an old style 3 blade IVO prop, I
took several still photos. Some of the photos appeared to show the blades
advancing or retreating much like that of a helicopter.....not sure if this
was a trick of the camera or actually happening. After about 10 hours of
ground time I found damage to the base of the blades. Now that the engine
is flying with an MT prop I have been unable to duplicate that effect in any
of my photos.
Russell Sherwood
Houston, TX