I've been making my own airplanes. They are are cross between SPAD and the Sturdy Birdy. I use coroplast to make the wings and PVC for the fuselage. I copied the 3/4 inch Aluminum channel coming out of the fuselage from the sturdy birdy. Great planes "Durapane" also uses this Aluminum Channel in their design. The result is a plane that is easy to construct, has a place to mount the electronics, and can survive rough treatment. I have built 3 so far and they all fly extremely well with one exception. They want to climb. I have to add a lot of down elevator so that they will fly straight. The planes are balanced. I've even made one nose heavy, but still it wants to climb.

I have noticed in the design of the sturdy Birdy II that they angle the engine down. My guess is they have the same problem and have solved it by making the engine pull down on the front of the plane. This design has to result in a loss of efficiency. I don't want to angle my engine down and I don't want to keep adding weight to the front of the airplane. My wing is as far back as I can go.

What is causing my planes to climb? Is there anything else I can do to keep this plane from climbing?