Why won't my planes take off?

[hollyfeld]

I have a very frustrating, recurring problem with planes. I cannot get a simple plane down the runway without it losing yaw control and crashing! This has been a problem for me across many versions of KSP. I try tweaking everything I can think of: types/number of wheels, steering on wheels enabled/disabled, wing shape/size/placement, control surfaces size/placement/authority control/deployment, reaction wheels setting/quantity, engine quantity/size/placement, ...and probably more. I've even tried with all three levels of runway; at level 3, the plane seems to take a little longer to start wobbling, but still does long before I reach a speed that will allow take-off. I'm using only stock plane parts (see list of mods below).

AAAARRRRGH! I have a Career Mode game with several contracts that require flying around Kerbin, and I can't even get off the %&*@! ground. Specifically, once my plane exceeds ~35 m/s, a yaw wobble begins that only gets worse as my speed increases. Eventually, my SAS cannot halt the swerving, and almost immediately my own keyboard control cannot override the swerving. I swing off the runway and crash. Every. Single. Time.

My KSP version is 1.2.1 (updated by Steam), and these are the mods I have: DMagic Orbital Science, Extraplanetary Launchpads, Firespitter (came bundled with USI mods), SCANSat, Tarsier Space Technology, TweakScale, and six USI mods (Asteroid Recycling Tech, Freight Transport Tech, Konstruction, Exploration Pack, Submarine Pack, and Modular Kolonization System). Also, below is a Dropbox link for my most recent plane design if anyone wishes to see it.

https://www.dropbox.com/s/pfob9s7m77vrfsa/Exploration Plane.craft?dl=0

[HebaruSan]

The rear landing gear is too far back. It should be just behind the center of mass, so it's easier to tilt the plane up on it like a seesaw.

The craft has almost no pitch control. Try putting a horizontally-oriented control surface near the front or the back of the plane, or tilt those tailplanes more towards 45°.

Try using just one forward landing gear instead of two. With a 2x2 setup like this, KSP planes tend to lose stability as one of the wheels slightly lifts off the ground and the other then imparts a yaw force.

[Tex_NL]

Recurring questions like this is why I stared the FAQ.

At the same time I wonder why I even bothered to do it. Clearly people do not read it.