Syd, thank you for your answers but surely there has to be an axis of rotation if the body rotates.
The essence of a helicopter in the hover is that it does not move or rotate - it is in static equilibrium - and there is no axis of rotation. It means that the sum of linear forces is zero and the turning effects (couples/torques) are balanced.
When analysing this you must be sure that you have identified all the linear forces and all the couples. It is my ability to do the latter that has thrown doubts in my mind.
If my sentence is correct then applying lateral cyclic gives a force acting at the rotor head which, again, if not aligned with the vertical C of G, will produce a rolling moment as well as a lateral force to oppose TR drift.
That is true and is one couple I am pretty sure of. But what is it balanced by?
