Originally Posted by
JPerrone
There is a force-vector reason that you might need to hold rudder; but this might not prove to be true for a "real" model or airplane. With a cross wind, there's some sideways force. This is applied against the entire side of the craft. The total force behind the CG is trying to make the plane turn into the wind; the total force in front of the CG is trying to turn the plane away from the wind. If those forces equal; then there's no need to hold rudder.
The vertical stabilizer has a lot of area; the area behind the CG could be greater than the area in front; and the plane would essentially want to weathervane, ie , turn into the wind.
This is all theoretical of course. I would not be surprised if most airplane designs were such that the area of the airplane behind the CG is close to the area in front, so that the plane doesn't experience these imbalances
Regards
You're still not getting it JPerrone. That is seriously wrong. There is NO sidewind to the aircraft. It does not feel a sidewind blowing on its fin or fuselage.
A steady wind does NOT cause a force on an aircraft in flight. Forces cause accelerations and there is no acceleration. The moving air mass is a frame of reference that is moving relative to the ground and the entire set of dynamics of the aircraft is in the air's frame of reference. You are still trying to do flight dynamics based on a point on the ground but aircraft handling knows nothing about the ground, only the air it is in. It doesn't know there is a steady state wind at all.
The wind is only relevant to us for navigation.
You are over-thinking this and introducing fake physics to make this far too complicated and in error.
It's very simple. If the plane is going a bit to the left of where the pilot wants, he turns a bit to the right. Turn by banking, not yawing by rudder. Assess and adjust as required. It really is that easy.