I may be wrong.... but.....
Say you elect to fly manually - no A/T, no FD on your side. So you turn your FD off, and deselect speed mode (ie A/T armed). This makes the other pilots FD master, and there is no FD pitch bar, since there is no pitch (speed) mode selected - since you deselected it to keep the A/T armed.
So to keep the FD on for the other pilot, a speed/pitch mode has to be selected and therefore the A/T has to be off to keep manual thrust. But this will only be the case when using a "path" pitch mode (ie: App, V/S, VNAV, Alt Hold)
Is this correct? Or am I mistaken?
I'm trying hard to put an example into words - but I tried it a few days ago, and to keep the other FD doing it's thing as well as me being able to have manual thrust - I had to have the A/T off rather than armed to do so. I'll see if I can come up with an example!!
[This message has been edited by 2 and 70 (edited 06 September 2000).]