' Moving the wing forward on a pattern model to keep the airplane stable is the wrong direction to go, and a big old time pattern Myth and the wrong correction to fix the problem. '
Hi Bryan,
At the risk of been seen as argumentative ;
Take the example of a pre-existing design that is, for the sake of this conversation, E powered with single prop drive and is already borderline in yaw damping/stability for F3A purposes.
Replace the single prop with a contra.
Two things result immediately;
- The CG is moved forward.
- The effective side area is increased by the extra prop - but this increase is at the front - thus adversely affecting yaw damping/stability.
In this scenario moving the wing forward to re-establish CG as % of MAC and or to re-establish relative side areas would seem reasonable to me.
Brian