J Johnson, A center mounted tail on a canard has virtually no
 lever arm
 length and would be huge, if moved back wetted area and CG
 problems are a
 concern. The wing tip rudders deflect outward only on most designs and
 affect drag far from the CG to yaw the aircraft, and a 2 degree
 incidence is
 believed to turn drag into a small thrust vector when not deflected.

 george grimes

George, I think we're in agreement! Having the tail right near
the props is not going to have alot of effect [hence the thought
of extending the tail [empennage] . Control of asymmetric thrust using
drag /tip rudders seem's to be counter intuitive in that during single
engine operations one needs ever ounce of thrust they can get..

I think the better option here [my opinion only] would be to create
some form of a dual props in an axial config, best of both worlds
so to speak.

Fwiw

J. Johnson

You guys are missing a little something. The Rutan rudders move only
out. They do more with drag than they do with side force.
Since the lever arm is so great a little bit of drag goes a long way.
Pardon the pun :)

Sort of like th split ailerons on the Northrop flying wing.

Paul Lamar



From my reading on the subject they only move out so as to avoid the
need to balance them, and I agree on the function by drag point.
Decker, Michael