The v_tail area should not include the rudder - that has a separate area value.
What I’m saying is that when you enter values into the flight model and go into dev/debug mode, you can see the boundaries and location of the various surface areas the sim has calculated to use. When you put in wings, for example, the boundary markers show up (overlay) at approximately the area of the wings as rendered in the 3D model. Same with H_stab. Adding ailerons and elevators show independently, but correctly, and move when you deflect them.
However, when you enter the V_Tail area, sans rudder, the generated boundaries are only half the size of the rendered v_tail. This was replicated across every aircraft I tried. To get the boundary to display correctly, you had to enter twice the surface area of the actual V_tail. My theory is that it’s either rendering the boundaries incorrectly, or it’s expecting too large a value.
The first scenario - if the sim is purely following the generated boundary, would cause a lack of rudder authority. The second scenario - if we tried to conform the boundaries to the 3D model, could potentially cause too much stability, control authority (and weathervaning, etc). The third possibility is that entering the correct real-world area value is correct and the sim treats it as such, but just renders the boundary locations wrong, which would be misleading upon debug.
I’ve asked Asobo several times, here and in the dev forum and there’s been no official response and none of the few folks that have discussed this can reach consensus on the rationale.
(Edit to correct “rudder” to “v_tail” in the third paragraph)