In forward flight, the helicopter's equilibrium is affected by CG, lift vector, drag, tail rotor effects, etc.
To roll that helicopter you tilt the disk so the lift vector and weight create a couple. Once they no longer create that couple, rolling stops. Of course, the attitude may not have been level in equilibrium. This means the couple may be a different magnitude for equalt left vs right tilting of the lift vector.
When you input cyclic, you induce a cyclic pitch change that results in the disk tiliting. As pointed out previously, the amount of that change is subject to the blade pitch while in equilibrium, relative flow velocities, amount of flapping, etc.
There's also a rigging factor to consider. If roll in the collective does not create a linear change in blade pitch, then displacement left vs displacement right would only cause the same pitch change if the equilibirum were at a point of symmetry in the roll rigging.
That's some of the stuff I considered may explain this phenomena. After thinking through that list I realized it would be more incredible if the same input resulted in the SAME roll rate vice resulting in different roll rates.
I think the only way that roll rates could be balance would be if it were designed that way...that may come at the cost of something else.
Last edited by heedm; 18th July 2002 at 07:15.