Aucky, I was interested in the transient Tq spike whilst rolling around the longitudinal axis, not the increase reqd to maintain S&L.
As far as I understand, when rolling Rt, the Tq will rise due to the difference in V of the advancing and retreating blades (assuming fwd flight). The Lift increase on the advancing side will be multiplied by the V squared which will be greater than the reduction of Lift on the retreating side. this leads to a net increase in Lift (whilst rolling), and therefore a net increase in Drag too. Hence a short lived Tq Spike. Add to that a bit of right boot to maintain balance as the ac wants to yaw left in sympathy and you have a noticeable Tx Tq inc.
It looks like the opposite should be true when rolling left. Indeed it does, but every time I observe it it seems a much smaller change. there must be some other force masking the effect. I can't think which one though...
Last edited by CPGAH; 21st October 2012 at 18:56.