How to design a laterally stable spaceplane?

[Aghanim]

For some reason every spaceplane that I designed always swerve either right or left and crashed at the runway. Even FAR diagnostics tool and simulation doesn't help at all. I already use symmetry mode yet sometime the center of lift is not aligned with thrust

[theflyingfish]

FAR has a well known bug where for some reason the Center of Lift isn't symmetrical, even if all the wing and tank parts are. It's only visual. The CoL is actually aligned, its just a display bug in KSP. So the Center of Lift isn't the problem.

If it's a problem on the runway takeoff roll, it's probably your landing gear setup doing something wonky. Make sure your main gear is right behind the center of mass, with your nose gear far forward. A picture of the problem aircraft would help.

If it's a lateral stability problem in the air, that could be a serious issue with your aerodynamic design. Again, post a picture and we can help.

[Aghanim]

Here is my ship design

EDIT: It rolls at the runway. Every time I accelerate several seconds later the plane will either go left or right and rolls and everything explodes

Edited July 30, 2013 by Aghanim

[Aghanim]

EDIT: It has been merged with my other reply

Edited July 30, 2013 by Aghanim

[antbin]

Your Center of Lift (blue arrow) is too far behind your Center of Mass (yellow ball). The back of your plane is lifting off first and "wheel-barrow"ing the weight onto the front wheels.

[strongest_2hu]

Having two landing gear in front (and two in back) is flirting with disaster in all but a few cases. In general, if you have more than three, you're gonna have a bad time.