# Control Surfaces working in reverse?

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the Control Surfaces on my swept wings of my simple plane seem to be working in the wrong direction when i pitch up and down

is this correct or am i attaching them wrong? It doesn't seem to matter what way i rotate them in the SPH

top view of plane

nose pulled up, front control surfaces go down, opposite to what i would think they should do

nose pushed down, front control surfaces go up

the view from other side

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When they're in front of the CoG, they'll seem like they're pointing the wrong direction, but they're pushing the nose instead of the tail is all that's happening. It looks weird, but it should still work fine.

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When you want to pitch up, the back control surface angles upward to make the back of the plane go downward, and since the second pair of control surfaces is closer to the front, it angles downward to push air under itself, to make the front of the plane lift up.

And the opposite is for pitching down.

...what is the issue again?

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The only thing wrong is the fact that the ailerons are moving which the shouldn't if your trying to change the attack angle (The elevators are fine). Also when flying make sure you use q & e to turn and not a & d (rudder).

Edited by what-the
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It has to do with Newton's Third Law of Motion; " To every action there is always an equal and opposite reaction: or the forces of two bodies on each other are always equal and are directed in opposite directions."

So, as was mentioned earlier, control surfaces in front of the centre of mass (CoM) will want to orientate themselves in such a way that the front is pushed up (to increase the pitch) and vice versa for the control surfaces to the rear of the CoM.

The rest really explains itself. If you need me to elaborate further, however, just ask.

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It has to do with the way control surfaces are mapped automatically. It's done using the same logic as RCS thrusters. That's why all the control surfaces in KSP behave a bit differently than standard airplane style. For example, if you in a coordinated left turn, pitching up to stay level, and then try to roll right:

Ã¢â‚¬Â¢ the ailerons work properly, but in order to help the roll,

Ã¢â‚¬Â¢ the rudder moves left (pushing the nose down) and

Ã¢â‚¬Â¢ the elevators split up and down like elevons (also pushing the nose down).

Maybe someday we will be able to map control surfaces manually. But until then, we can get better results by removing the rudder and putting the elevators as close to centerline as possible.

I like your idea of putting the ailerons forward of the CG. That actually has a beneficial effect of pushing the wing up when you pitch up, and pushing the wing down when you pitch down. It's more responsive to your commands. Unfortunately, that means breaking the rule of putting the wing slightly aft of the CG. But if it works, it works.

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The screenshots look correct. I did, however, notice that the canards (in front of the CG, otherwise they're not strictly canards at all) seem to point the wrong way in some of my designs. They still give torque in the right direction, but visually they go the wrong way.

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canards (in front of the CG, otherwise they're not strictly canards at all) seem to point the wrong way in some of my designs. They still give torque in the right direction, but visually they go the wrong way.

I've noticed this sometimes, too.

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it'd be nice (hint hint) if someone, maybe the devs, could include a mapping to restrict surfaces to a particular mapping (or at least, a function to make it part of the part.cfg) because vertical non-symmetry rudders REALLY screw up roll control

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yeah i guess i thought the front control surfaces would go up to pull the nose up but instead they go down to push the nose up, same result just looks weird

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• 1 year later...

so basicly they haven't fixed it and they don't plan to? Game's not worth buying then.

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so basicly they haven't fixed it and they don't plan to? Game's not worth buying then.

Haven't fixed what? as pointed out nearly quarter of a year ago the OPs "problem" was a misunderstanding.

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It's not a problem indeed, the wings are just in front of the CoM. Also, this is indeed old. Don't necro guys please.