HFD
I believe you've misconstrued bookworm's post (either that, or I have, and he'll be along in a minute to correct me!).
The axes of reference that I believe bookworm is referring to (and certainly I'm referring to) when talking of pitch and yaw are the aircraft's axes. Any turn (whether level, climbing or descending) comprises a) a pitching motion around the aircraft's lateral axis together with b) a yawing motion around the aircraft's normal axis; the relative magnitudes of these two motions depend on the bank angle. Whilst rolling into a bank initiates the process, a key question to be answered (and understood) is what causes the pitching motion and what causes the yawing motion. These two motions are the secondary effects of roll. In other words, having created a sideways force by inclining the lift vector, why does the aeroplane take up a circular arc rather than merely 'lift' sideways? Or, to put it another way, if the sideways force (earth reference) is automatically a centripetal force, how come the vertical component (earth reference) doesn't have the same effect (and continually loop the aeroplane)?
Bookworm was, I believe, suggesting that some of the confusion in this thread arises from some posters interchanging yaw and sideslip as if they are the same thing. They are not! Edited to add that, even in the case of a 60deg bank turn for larger pitch influence, or 15deg bank turn for larger yaw influence, the rates of yaw and pitch are low compared to some other flight regimes and hence more difficult to perceive ... maybe this is part of the confusion.
Last edited by Islander2; 29th March 2007 at 18:49.