Lu, Lu, Lu,
1. Flapping has nothing to do with cone angle.
2. Precession has nothing to do with cone angle.
3. While the tip path plane changes with the introduction of cyclic, and the disc is tilted left (American heicopter) due to tail rotor roll, neither of these have anything to do with cone angle.
I suggest you look up the definition of cone angle, and then mix in all the other complications. Again, we are stuck on basics.
Dave:
Changes in cone angle do affect the RRPM due to the conservation of angular momentum. Coning angle is a function of G (or to be more accurate: the lift being produced by the blades) Vs RRPM where and increase in lift or a decrease in RRPM will increase cone angle.
Thus, when you flare the aircraft, you are (apart from aerodynamic flare effects) increasing the G and therefore the apparent weight of the aircraft. The cone angle thus increases. As the cone angle increases, the CofG of the blade moves closer to the center of rotation, and the RRPM increases (conservation of angular momentum). The RPM increase is limited by the fact that an RRPM increase will cause more centripetal (or centrifugal if you prefer) force thereby trying to reduce the cone angle. The engine spools down to get the RRPM back to 100% (governed turbine here) and a new equilibrium is found. As you relax the flare or bunt, the reverse happens: G is reduced, thus coning angle, thus CofG moves out again, and according to conservation of angular momentum, the RRPM droops until the engine can catch up and restore equilibrium.
The old analagy is the ice skating bint. She enters a spin and then draws her arms into her body. She goes much faster, her dress lifts higher and we can enjoy seeing her knickers (why else would you watch ice skating?) . She then puts her arms out and slows down, her skirt falls and there is no point watching any further. Conservation of viewer intrest...I mean angular momentum!!
As for teetering heads, you have bought Lu's line on Bell teetering systems. Despite Lu's theories, the Bell blades do flap individually without an equal flap down on the other side. Accordingly, they react the same with regard to cone angle and conservation of angular momentum. And all those whom have flown the Huey can tell you, there is a LOT of coning angle visible after a touch down auto if you are anything like me!!
What is the knuckle joint effect? Is that what I experience when I get drunk and gob off in the bar, or is it another term for Hookes Joint Effect?
