Originally Posted by
Owain Glyndwr
Sorry, I have to disagree with you on fin and rudder remaining effective at high AoA.
I think what mm43 was saying was that rudder is *more* effective than aileron in the stall regime, which is undoubtedly true. Obviously at extreme AoA this effectiveness will decrease - possibly rapidly.
That graphic you've posted (thanks by the way - very illuminating) shows that rudder effectiveness on that design approaches 0 at around 60deg AoA. AF447 maxed out in the 40s. Fig. 9 suggests that rudder remains significantly effective at that point.