ORIGINAL: XJet
I guess I'm spoilt because I fly mainly very well designed profiles -- most of which have virtually no coupling in knife-edge, which means that they're really quite easy to fly on the sticks.
I have to admit that flying a plane that kife-edges very poorly can be a handful -- but I only ever had one plane (a fatty) that flew like that and I got rid of it.
We've got a guy in our club who can fly almost anything knife-edge -- he delights onlookers by doing an entire (dead straight) KE pass along the runway with his CMP P51 Mustang. No mixing either :-)
You just don't get it. The mixing should be on at all times, because the coupling you see in knife-edge is just a symptom that... well the plane coupling issues. Coupling is not knife-edge specific, it will be present at all times. Try flat turns using rudder only and you will see that exact same coupling your model displays in knife-edge flight.
This is not about knife-edge, but correcting a bad behaviour of the model to improve every manuever where rudder is appliede. Be that pointrolls, harriers, hover or whatever.
Somehow a have a feeling you just want to stir things up. The give away is you been spoilt with great flying planes that all have virtually no coupling. Because about all planes does have coupling. Identifying it and knowing how to correct it is another thing
