Rendegade,

Have attention for this picture, the angles are better visible.

Even the Taurus does fly with an angle of attack of 10 degrees (light/dark blue) at (controlled!) low airspeed the AOA of the stabilizer in the down wash is less than 2 degrees (orange/green). We also see the flight path indicator and later the development of the vortex of the wing tip.

There are a lot of posts about this, read this for example.

http://www.rcuniverse.com/forum/fb.asp?m=8319781


I wouldn't worry about any 'downwash' off the main wing either. I have somewhere a publication where the chief aerodynamicist for BAC (who have the time, money, requirement, tools etc to find out) states that the local change in the freestream direction (downwash) due to the lift produced by the wing can extend as far back as 1.25 chords behind the trailing edge of the wing. If a 100 ton airplane, operating at speeds, AOA's and lift coefficients unapproachable by any model airplane, and influencing cubic acres of air can get the downwash to extend as far as 1.25 chords behind the wing, I would go so far as to say that no normal (wing at front, tail at back) model airplane will have any downwash effect that could possibly influence any tailplane. He also stated that this wash actually reduces the lift generated by the wing (like the wing was 'climbing a hill' all the time). I think you can forget any 'downwash' calculations with wing/tail setting angles.
Evan, WB #12.


I do show that 1,25 short distance in the photograph.

When these kind of theories are right, than we have to believe the stabilizer would have to function under an AOA of 10 degrees? Of course not and we see for the Taurus the AOA of the stab is less than 1/5 th of that of the wing, so even a flat plate often can do the job.

For me these are facts of dowh wash I count with, not only for my gliders but also in the design of the Simla I am working on these days.

Cees