Lu, what's with the permanent thumbs down mate?
Regarding your comment about the gyroscopic pitch change mechanism on the Cheyenne(although I haven't seen it), it sounds a lot like a stabilising device.
Some gyroscopic forces must certainly be associated with whirling massive components, but as Nick Lappos pointed out above, the actual movement of rotor blades is fundamentally an aerodynamic thing.
Harking back to the old Huey again, the pitch change is accomplished by hooking up the pitch change rods from the swash plate to the stab bar (you may already know about this so apologies if it's telling you how to suck eggs) which is the rod mounted at 90 degrees to the rotor blades, and connected to them via the pitch change links and an oil-filled damper.
Basically, the stab bar whirls around and tries to remain rigid in space, and if the rotor blades are perturbed by turbulent air, the design of the connecting rods in the system leads to a pitch input to correct the disturbance.
For pilot-induced cyclic pitch changes, the swash plate moves the control tubes which act through the stab bar system to the pitch change links, leading to cyclic pitch changes on the blades causing them to fly to the new desired position.
So I guess what I'm saying is, gyroscopics have a place in rotor design, but aerodynamic forces are what makes the blades fly as they do. What you're talking about above sounds like it's designed as a stablilising system, and the pitch inputs to the blades are still what lead to disc movement.
To Dave Jackson et al, enjoying reading your posts. A bit of constructive discussion is a good thing!
[ 06 August 2001: Message edited by: Arm out the window ]