Re: http://www.charlesriverrc.org/articl...tailsizing.htm

That's handy, thanks!

Re:
V-tails are usually designed with 110 degrees

They may be built that way, but that's not "designed".

Well, sure it is, but the designer might not have employed any engineering. Anyhow, for stab areas of 20-25% 110 degrees yields a functional though perhaps not ideal vertical stab area, so I suppose that is why it is one of those old rule of thumb principles.

MJD