On Nov 20, 1:05*pm, "bumper" wrote:
No answer on your questions . . . however, I do know there was at least one
incidence of the 4-blade prop making like a Frisbee. One minute it was
dragging the Pawnee through the air, the next it was on it's own and
accelerating away from the plane.

Guess it's important to re-torque the prop bolts?

bumper

That brings to mind a local story. There was a group of retired
geezers rebuilding an Aeronica 7AC Champ. The engine had just been
hung on the mounts and one of the group decided to see how it look
with the prop. He hung the prop on the crankshaft flange collars and
went looking for the prop bolts. Another of the group tried to rotate
the prop out of the way.

The engine which had set for years burst into life as the impulse
magnetos hadn't yet been wired to the ignition switch or the throttle
cable run to the cockpit. The engine revved to redline and then ran
out of gas in the carburetor float bowl which launched the unbolted
prop through the hangar wall.

All geezers present were by then face down on the floor or hiding
under old cars. The story came to light when various members of the
group showed up at the airport restaurant and were forced to explain
the bandages covering cuts received while diving for cover.