Capt PB
I like your "its stirred up the air and that took energy" approach. Its clearly good to have a variety of ways to give students a feel for lift dependent drag and I'm sure Mr Lanchester would approve of that one!
Cheers
JF
PS Sorry, I forgot to respond to your body axes point. Absolutely. The early days of long and heavy fuselages and smallish wings (say the F104, but it applies to plenty of others) produced the odd departure with the mechanism being termed "inertia cross coupling" If you roll such a beast quickly it wants to rotate about ITS long axes (naturally) SO, if you had a stack of AOA on at the time you started the roll, that AOA became sideslip after 90 deg of roll. 90 deg further on it was negative AOA - you get the picture I'm sure. So inertias were cross coupling with aerodynamics and produced pretty severe results.
If an aircaft has highish aero forces and lightish inertia forces (like any GA aircraft say) then as you do the start of the roll the directional stability works normally (overpowers the inertia effects) and reduces the sideslip that would otherwise result after 90 deg.
Sorry if I'm teaching granny to suck eggs
JF
[This message has been edited by John Farley (edited 18 November 2000).]