Curebores

That seems to have done the trick. Thank you very much. Another quick question. Using the rudder for more than a second or so at a time will cause the plane to roll rather than yaw, which makes the fine tuning for landing a bit of a challenge. Any idea why that's happening?

Hi there. I'm having problems with a plane I am trying to build. This plane can take off (if a little bit squirrley), fly straight, climb to 6k+ (or 30k+ with the rocket), and land. The problem comes when trying to do any kind of sustained turn. You can just about fight it round in small increments, but try and turn hard either by banking or roll/pitch and it will have you doing aerobatics until you hit the ground. A previous version of the plane flew very well, with none of those problems. It had no science or service bay (0.35t less weight and about 1.5m shorter) and different landing gear (the basic ones, which would randomly explode sometimes) but otherwise identical. Obviously the wings etc were in slightly different positions for balance. I have no idea what's wrong with it. According to everything I know about aircraft design in KSP (Which admittedly is only slightly more than nothing) this thing should fly true. It is too long/heavy? Have I just completely messed up everything? Any help would be appreciated.