dCl/da
"i'm sure someone as on the ball as you can figure out how to use such an output to give a whole raft of useful information."
cut the sarcasm, it doesn't suit a helicopter designer? more like Crab's style.
"One obvious one would be how well a turn is coordinated, perhaps? " yea that why I said "sideslip?" (obviously !)
Lonewolf thank you for your informative answer, I wonder if that is to help the fact that the swashplate is not orientated it the same plane as the zero-pitch plane?
(dCl/da any view on that? Maybe try googling it?)
[ and glad you see where the 90kts comes from, some others on here found it hard to understand (surprisingly !) ]