I have the Hor-tail at 22.4 sq ft and the verticals at 14.88 sq ft total. I have a sub fin of 1.94 sq ft + the fin at 5.55 sq ft for a total of 7.44 sq ft each side. This is a vertical of .046. I worked on this last night before bedtime and was tired and sleepy. I found a mistake in my math from last night so the vertical changed from .045 that I quoted earlier to .046.Dan,
Using your wing and your desired H-tail coefficient of .52, and a 14' lever arm (your 11' from TE of wing to front of H-stab + approx 2.5' from TE to CG + plus approx 1' from LE of H-stab to MAC of H-stab), I figured an H-stab+elevator size of 21 sq ft. Close to what you got?
Using the same method for the V-stab and rudders and your desired Vertical tail coefficient, I came up with 15.3 sq ft. In the ballpark?
I'll figure my numbers later, they'll be close to this. I was thinking theoretically the H-stab could probably be a bit smaller than the standard Raymer formula because of the endplates formed by the V-stabs and rudders. But it's always good to have a little bit extra pitch authority especially in a one-off with some unknowns.
25 feet long: Just a foot longer than a C-152 and your wings are just a foot longer. With wings folded back at the spars, they'll still be a bit shorter than than the tail. The whole thing would fit in a standard 40' long shipping container with room for parts and a workbench in the front.
I'm ignoring the end plate effect of the verticals and like you I like to error on the high side of pitch authority.
The .046 will give it good yaw stability and I like large rudder authority so the percentage of rudder to fin area will be on the large side to keep the crosswind component as high as possible with the good yaw stability.
Room in a 40' container sounds good.
Added -- found another mistake so the numbers are correct now.