I'm not certain, but I think there are a few piston planes out there with reversing pitch control. I think the Queen-Air may be one. I know that when you get a prop stuck in feathered position in a Cesna 402, that it is impossible to start the engine on the ground.
I wonder what the pitch control is on helicopters? I see linkage rods that come up to the rotors, but I'm not sure what device moves them up and down. I was told a story once in flight school, which of course means it could be as false as true, but that a Ranger pilot lost pitch control and reached up thru the interior panels and manually operated the linkage by hand. He could only select full deflections though.
Helicopter blades change pitch
cyclically, in sync with rotor RPM. This is done by means of a
swash plate, which is under those linkage rods you saw. The pilot has two controls: one called the "collective," which raises and lowers the swash plate (thereby changing the pitch of the blades without regard to their position around the circle of motion) and the "cyclic" (if I have the word right), which
tilts the swash plate, thereby causing the blades to "wobble," as it were. This causes the plane of the spinning blades to tilt, thereby causing the force vector developed by the spinning blades to tilt as well. It is the horizontal component of this tilted thrust vector that propels the helicopter.
(steely)
a Ranger pilot lost pitch control and reached up thru the interior panels You may be thinking of the incident where a Forest Service Hiller lost the control linkage, and a passenger climbed out and used the marlinspike on his Leatherman tool to hold the linkage together.
http://www.helis.com/stories/impsit.php
d.o.l.
Criminal Number 18F