Rockets are easy. Planes on the other hand...

[nine_iron]

My only successful plane

Part count = 9

[BGog42]

SSTO Spaceplanes are my my obsession and my bane. They are quite difficult to build and drive me MAD. But man the feeling of accomplishment is unmatched. I recently built a single-stage-to-laythe plane and I must have put in 40 hours working on that thing. MAD I tell you!

[bsalis]

I believe the reason is that the controls aren't even smooth. Even when fine controls are turned on (caps lock), the plane keeps rocking up and down when turning or exiting out of a turn.

Sound like a lack of static stability or too much dynamic stability. Flying to fast can also make things twitchy.

Best way to learn to fly is using an aircraft that is really well balanced and stable... with some practice, it's becomes a lot easier flying with keyboard.

[The Error]

Remember, due to KSP Wierd Physicsâ„¢, you should use control surfaces on the back (elevators, ailerons, or elevons) ad well as a canard of some type on the front. I have found that every plane I've built flies best with with forward and trailing control surfaces.

I think this is because the only way to maneuver with trialing edge-only controls is to use rudder/elevons to shove the tail of the plane around, when you really want to be leading with the nose. I don't use FAR, but I assume you'll still want canards or something forward - failing that, Go Really Fastâ„¢ and use a delta-wing design.

[Pipcard]

Adding canards helped a lot.

[Nao]

I'm currently experimenting with making spaceplanes. The problem I'm currently having is not having enough pitch control (as well as rocking in various directions when trying to do that). My plane barely pitches when taking off and doing banking turns.

And I actually made it into orbit once with an SSTO spaceplane today. Getting back down is the real challenge.

edit: This is the plane (slightly modified from the one that I took into orbit)

img snip

Having a tail will solve most of your problems. Momentum is force times length, your controls are very close to CoM so they don't give much pitch momentum at all.

Also If you have troubles at high speeds move the intakes behind CoM somehow.

Oh and your CoM is probably more forward than it looks because of gear weight glitch, set your craft CoM/CoL before placing it. That's why you need so much stick pressure to keep it flying.

(Some more things i had saved about building planes but never posted)

Things to note when building planes in stock ksp (and in mostly in FAR too):

CoL should be just behind CoM - everybody says that but there are a lot more to it:

- landing gear add weight in VAB/SPH but are weightless in flight, this makes CoM in SPH show incorrectly with gear in place.

- changes in CoM due to fuel burn , it's always good to have tanks bot at the front and rear to transfer fuel and balance the ship in flight (more fuel at the front - more stable flight) (more stick down to fly level means more stability)

- wings and control surfaces have different lift curve, if you place control surfaces at the front the CoL will drift forward as the attitude (AoA) increases (you can check dynamic stability of your craft in SPH by [shift] rotating the whole craft with CoM and CoL visible)

And more on construction, and stability:

- wings lift is greatest when the wing part is perpendicular to movement direction, that means if we angle the wings (ie. for appearance) left and right wing will provide different lift when plane yaws resulting in roll forces. Also since in KSP in level flight we have positive AoA, rolling the plane will create yaw - and vice versa, destabilizing the plane.

That's why its important to have some kind of a tail with wing surfaces on it (the longer the better).

Also wings and control surfaces provide lift at the part root so the closer we place them to the centerline the less impact they will create (ie. canards placed at the centerline will not give any roll force even thou it would look like they should)

- Intakes generate a lot of drag at high speeds, if they are before CoM they will make plane unstable (just like having an open parachute at the nose of a rocket does). Having CoL further behind CoM will increase stability but it requires a lot of control surfaces (preferably at the end of a long tail)

[kanelives]

are there any good plane mod packs? I have b9 but meh.

[Just_Testing]

Try to keep things simple would be my advice

This plane can hit speeds of ~2500 m/s, circumnavigate Kerbin twice without landing and make it to either of the poles in 13 minutes.

And here, my first SSTO - start small, as small as you can, before scaling it up. Balancing these things and keeping them stable after re-entry is an absolute bitch, be wary.

As for the turning off the runway problem, I think it's something to do with the fuselage flexing under the craft's weight, causing the nose wheel(s) to move laterally, resulting in aggressive sideways movement. Try strutting the cockpit to something further back, and make sure it doesn't bend when physics loads.

Edited October 4, 2013 by Just_Testing
forgot to talk about the first plane

[epicbuilder333]

i've had this issue. My explaination?

true that!

[Jean Deaux]

I'm with you, absolutely hate the space planes for the same reason, waaaay too hard to control. I've found Lazers to be my Salvation when it comes to flight control, it flies smooth and makes maintaining your heading much less complicated. If they could work out the jerkiness of the control surfaces that would be awesome, I know hooking up the joystick did little to improve upon that aspect.

I've been at this a while and am only just now getting one or two designs to actually fly, big or small. Only once have I actually made it to space, haven't been able to do it again with the same craft so clearly I have some learning to do. I'm feeling your pain, ranting right there with you. Good luck!