Andyede, an excellent summary of the intuitive understanding I've gained the last few days. Having worked doing physics and electrical engineering for many years the steady state equation

Applied Torque=Drag at Steady State Roll Rate

tells me much about the roll behavior (there are very many systems that follow the same sort of force balance analysis). I sort of worked the problem backwards having an intuitive understanding of the behavior, then trying to understand all the details. The devil is always in the details, so I posted my random thoughts here to keep me honest.


I don't think the stopping of the roll is quite as simple. The rapid angular deceleration when the ailerons are released is close to opposite, but the behavior around zero roll rate is determined by other factors. The standard analogy would be a mass on a spring on a table. The behavior around zero displacement is controlled by the mass, stiffness of the spring, and damping. The system can oscillate or exponentially damp to zero. I'm not sure that the simple spring analogy is very accurate for an airplane. It might be if you put a wing in a wind tunnel, had a constant wind, and restricted motion to only rolling. There is a lot of coupling between forward energy, pitch, yaw and roll in aircraft so the damping and stiffness about zero roll rate appears to be very complex.

Ben is correct, for my Killer Kaos, by the time I complete a few rolls I'm already turning into the next pass and would not notice the roll characteristics as it approaches zero roll rate. I am not a pilot, but my limited full-scale experience says Bax is correct -- stopping roll does not seem to require reverse control input. I don’t remember any planes that tended to oscillate in roll so the damping must be pretty good even at very slow roll rates. I’d be curious if an aerobatic or fighter pilot notices the final roll behavior when coming out of a rip-roaring axial roll.


Carl