Originally Posted by crab@
oTW - even with a teetering head helo and a TR that is above the MR hub, I don't agree that you will have a right roll as you always have to tilt the disc to the left to oppose the TR drift - I think the best you can expect is laterally level fuselage in that condition. The disc is 'flying' left and will tend to drag the fuselage with it.
the fuselage will be level except for the moment caused by the height of the T/R thrust not being in the same plane as the Torque which must be opposed.
In this example height of T/R wrt the disk is the only thing influencing the roll required to counter that 'mismatch'
The point is : you
could measure the 'heights' of the horizontal components from the CoG - but the height of the CoG cancels out so it becomes the height of the T/R horizontal vector compared with the height of the plane in which the torque is delivered.
So a T/R hypothetically above the plane of the disk will lead to the counter intuitive roll direction... (in a teetering rotorhead)
Head coupling might modify that since to produce a M/R horizontal component which is equal and opposite to T/R thrust some roll moment from that will occur.