(Moved from "Affecting Thrust, Propeller". See photo there for an image of this aircraft.) Perhaps you might know one thing that I can't see in the available photos. I looks like the aircraft has elevons extending from outboard of the vertical stabilizers to near the tips, rather than separate elevators and ailerons. Do you know which configuration was in use? Some of the stuff in Nickel & Wohlfart's book suggest that separate surfaces might be desirable in a flying plank, and I was wondering what the Opel's designer was using. The other piece of information I'd like to know was the approximate aspect ratio. Looks mighty small, although he appears to be making use of that to increase the chord and maybe get a little more pitch damping out of the wing. I'm completely guessing on that latter - any thoughts?