Evening,
But is that secondary 'yaw' effect what is removed by using co-ordinated controls?
So *if* the turn was completely balanced, personally I don't think that there would be any yaw.
However my flying experience extends to 5 or 6 solos in air cadet gliders, if anyone is more informed than me please do jump in!
Ah one other thought... If we are considering the vertical axis to constantly remain 'vertical', would you consider a turn where there is 90 degrees of bank (unlikely, I know!) to be yawing the aircraft?
All the best,
James