This is my dream's thread....

Thx for take your time, sure I'll learn more every time...

Mike, the way you got to the Tempest is amazing; I was always concern about wing and stab up or down move and effect on plane....

Doc, a friend tell me that wing tip is like trainer tip; it make the plane stable, as Dick say, make dihedral job

tph1, I was trying to get a formula to CG placement too without find nothing about; I guess it's a very personal parameter for every plane and designers have to play with it to match the plane they want, all around the engine; I'm newbie to design, just trying to learn, and maybe I'm making all wrong, but with Extra I'm building, must move CG rearback about 2" for balance, from wood prototype CG placement; I think it will loss longitudinal stability like Mike say and will be very "wild" tail for me (better than unflayable), but since it's a project, I take the risk and see what happend; I'll post the results.

I have Typhoon 2000 and Patriot 3D plans, and CG are in diferent place; distance between wing and stab are diferent too, not to talk about aifoil, engine-wing spacing, double tapered wing vs a straight trailing edge, etc.... too much numbers to work for me at this moment