As always with really off the wall ideas like this you can learn a lot from doing what you're planning in a smaller scale. Make up a test glider from foam for the fuselage and simple flat sheet for the surfaces. 1 inch blue foam for the fuselage cut and sanded to the approximate profile and taper and 1/16 sheet for all the surfaces and a wingspan of 18 to 20 inches.

If you can't make it fly in a stable manner as a glider it won't do any better with an engine and radio. The CG will likely be at or just in front of the "trailing edge" of the rear wing.

You can try those strakes but I'm not sure that they'll be effective enough.

The test glider is the definately the way to go. Thanks for making that point Bruce!

Ok here is a crazy idea, sort of a Hail Mary pass if everything else fails. How about a steerable engine? Think outboard boat engine. I would think that +/- 10 degrees would be enough. The mechanics would be easy enough to design, the issue is whether the servo load would be too much. What do you think?

Larry

I see no reason why it couldn't work. Backwards airfoils don't work? Yea sure, and you can't fly a flat bottom wing upside down either. The CG would have to be way back, probably behind the wing. A tricycle gear plane would tip backwards unless you moved the main gear to a weird looking rearward position. A "taildragger" could look normal and would in fact be a trike. The tailwheel would have to be tall enough to have the fuseilage sit almost level on the ground.
If you made it electric, you could reverse the motor direction for taxiing to complete the illusion.

When I sailed Hobie 14 sailboats, I would occasionally sail the boat backwards as a stunt. I pulled the boom way over center causing the rear of the sail to become the leading edge. I had to hold the tiller with a death grip because the rudders wanted to snatch over one way or another. That's what your servos will be dealing with on the plane unless the ailerons, rudder, and elevator are moved to the other side of the airfoil.

Some wing tip endplates might be able to act as verticle stabs without making the plane look too weird.

Directing the engine would be fine for steering as a substitute for a rudder but it won't replace the missing vertical area.... well it would if you could install a sensing gyro and some predictive computer control of the engine thrust and allow it to sweep back and forth like a windshield wiper to dynamically stabilize the craft. Or if you were to hook up the same sort of sensors and controller to some split drag "rudders" at the wing tips like the B2. But I suspect that would require more computing power and feedback than a typical heli gyro could provide and those are the only ones I can think of that are easily adaptable.

Not sure if its of any help.but the Wright brothers design was unusual,stab up front,rudder? airfoil?

Actually the Wright Flyer was a canard; with flying stab up front, under camber airfoil, with a dual rudder at the rear, very short coupled.

Actually, someone has beat you to it! In the Q&A forum under "what to do with an old trainer", there's pics of a trainer with wings reversed. Fake ailerons marked on wings, and looks like new elevators put on other side of "foreplanes". Also, looks like he's made an all-flying rudder/fin from the pics. Flies apparently!

I LOVE this idea - might buy a cheap ARTF trainer just to try it on.

Cam

camdyson,

Thanks for the lead. I didn't think that this was a new idea, I just couldn't find the kind of proof that you found. It doesn't bother me that others have done this before. I jus think it is an interesting problem to solve and should turn a few heads at the field. From the two pictures in that link it appears that a lot of what has been discussed here is similar to some of the techniques that was built into this model. Seeing it in real life and apparently in flying condition is really encouraging.

To things did catch my eye. First the post is relatively new 6/9/07 and second, it looks to me like this plane has its main wing turned around so that it is flying in its proper direction (but I could be wrong). If so, I would like to build one where the wing profile is reversed.

Thanks again, good work!

Larry

It would be fun to have a challange at the local club to build some of these things and have some competitions related to looks, aerobatics, and overal creativity.

Tall Paul as a lark installed a Kadet wing on backwards one day and flew it. I would imagine that it changed the stall charactaristics somewhat but on the whole he didn't have any trouble with it.

But that didn't have ailerons on it. when you start trying to control the model with front mounted surfaces a lot of bad things may start to happen. Flutter issues come to mind for one. There may well be control effect issues as well. No one does it that way so you're on your own to experiment on that one.

The vertical stabilizing area issue will still be the biggest one though. Look up some info on "vertical tail volume coefficient" and run some numbers to get a feel for it all.

BMatthews;

Control surfaces on the front suffer from "Dynamic Instability" If you deflect the surface, it "bites into" the air and the airstream exerts a force on it in the same direction it is moving. Now the actuator has to hold opposite to keep from overtravelling. Around the center, this can flip from side to side in a big hurry and in some cases the surface can be stripped from the airframe. At best you're flapping around unpredictably putting high oscillating loads on your servo.

See the sailboat rudder comment from B.L.E.

Moving surfaces on the front of a flying control surface are a bad idea, trust me.

N

Wanna know if it's possible to layout a model that looks like it'd fly in one direction but in fact is going to fly in the opposite direction?

Take a look at the thing in the "swept wing divergence" (or whatever the title is) thread.