How to make a space plane that doesn't roll over and explode on the runway constantly

[firerider521]

Title says it all. I'm really tired of this.

EDIT: Okay, sorry for the supernoob post. I know I didn't include much information. It seems that my problem had something to do with placing the landing gears on the wings. I don't know why this made me crash, but I somehow fixed it. Again, sorry for the dumb post, I was frustrated. Could a mod delete this thread, or at least lock it?

Edited July 10, 2013 by firerider521

[AnalogAddict]

Some folks swear by straight up and down landing gear versus angled off of a circular fuselage to prevent random explosions.

I personally use angled landing gear and place my rear set of gear right behind my CoM. Therefore, when I go to pull up, my plane actually lifts off versus having to ride out the entirety of the runway. (Note this is something that is trialed and errored until you get it right for your plane) This means that my plane is not over speeding which I believe causes the physics of ksp to randomly throw one wing higher than the other, which then begins to resonate within the craft and everything blows up.

Look at the design of one of my SSTO Space Planes, maybe it'll give you some tips on how to place your landing gear or at least some reference for an example that does work.

http://forum.kerbalspaceprogram.com/showthread.php/30368-Laythe-Nuke-SP-SSTO-20-OK%21

I'm not where I can fix the action group #1, it seems you should bind #1(or w/e you choose) to LV-N Toggle Motor. Not sure why, but that action group didn't survive the upload.

Also while in the spaceplane hanger, lower your craft until one of your gear begins to go inside the floor. Use that as a "ruler" to place your other gear at appropriate heights. I find that a level craft is a happy craft.

Edited July 10, 2013 by AnalogAddict

[Krisism]

I have this problem too fiverider. Half of my designs will just totally veer to one side which makes zero sense when you use symmetry and angle snap. I wish there was a better way to understand it, because at this point it feels like a bug in the game to me. Why would something completely symmetrical veer so hard to one side? Unfortunately, I just completely scrap those designs once it starts happening and start all over. Rocket building is so much easier/less buggy. I can build a rocket to do what I want it to on the first run almost every time, no funny business.

Edit: I've been testing, sadly, for hours - to try and figure more out. I've used literally just the fuselage, wheels and an engine on the top (angle snap to make sure). Even in these scenarios, there was massive veer. No control surfaces, sas, or lift. So that could only mean it is an issue in the wheels or in the body/fuselage itself. I've tried so many different configurations of wheels, straight, angled, ect. - and it doesn't seem to have that much effect. If I change the body type of the fuselage however, makes all the difference. No idea why. Maybe some pods/fuselage are not stable for flight? I can't explain it any other way This drives me totally nuts.

Edited July 11, 2013 by Krisism

[Lazro]

Most spaceplanes will just veer to the left slowly upon launch. It is, unfortunately, normal, but having an avionics package on your craft and tapping the pitch-right key when it starts to veer will usually fix the problem.

[Snooze]

To counter veer make sure you have either of two things:

Twin vertical stabilizers.

Or

That your nose-wheel (if in a tricycle configuration) is NOT attached to your command pod/cockpit. It's something to do with how parts attach to it.

[Krisism]

That your nose-wheel (if in a tricycle configuration) is NOT attached to your command pod/cockpit. It's something to do with how parts attach to it.

Excellent tip. I hadn't thought of this, but it's possible the command pod could apply torque to the wheel I guess. Pretty much all my design that fail had this in common. 'Cmon Jeb, back to the testing grounds!' (Actually I've probably killed the entire Kerbal race during testing )

Edit: After some preliminary testing, this is holding up. Major improvement moving the wheel off the command pod. I also find it a big help to trim up slightly (alt + a few times) so that it takes off as soon as it has sufficient speed.

Edited July 11, 2013 by Krisism

[firerider521]

Thanks for the replies, I wasn't expecting anyone to care

But it seems that a lot of people are having this problem as well, so I'm not alone!

[AnalogAddict]

Thanks for the replies, I wasn't expecting anyone to care

But it seems that a lot of people are having this problem as well, so I'm not alone!

You definitely are not alone, I fought with this issue for quite some time until I developed a pattern of placing landing gear in the same fashion. Yet, I realized quickly that hindered my ability to go "outside-the-box" as it were with my spaceplane/plane designs. Unfortunately, as with most other things in this game, its a matter of trial and error.

[FleetAdmiralJ]

Yeah, I couldn't tell what was happening with my planes when they were doing that. I think it was partly wheels, but I also figured that it was partly the flaps, that they weren't all going the same direction when I placed them. There was one set of flaps - I think they went on the wings - which NEVER seemed to go the right direction no matter how I put them on (unless they were right and all the other ones were wrong).

In any case, I've had about 2 successful takeoffs in about 30 tries, which is one reason I don't spend a lot of time making space planes, heh

[Tiron]

There's another way around this, involving something I discovered that was painfully obvious after the fact. Like 'First five minutes of high school physics' kind of obvious.

Your ability to get the nose off the ground is primarily a leverage issue: on most designs the rearmost set of landing gear acts as a fulcrum, with the control surfaces being the input points(and the entire PLANE being both load and the lever arm itself). This is why adding a set of canards on the nose helps a lot in getting the nose up sooner: Being so far forward of the rear landing gear gives them way more leverage.

But what it boils down to is that if your control surfaces are too close to the rear landing gear, it's not going to be able to get the nose up on the ground because they've got no bloody leverage. Most of my designs have the control surfaces pretty far back so moving the rear gear forward helps a LOT in getting it off the ground faster. It also makes it harder to get off the runway without destroying things on the back, though!

Getting off the ground sooner means you're not rolling on the runway as much, and don't get up to speeds that are nearly as high. On some of my poorer designs in this respect, they couldn't get the nose off the ground until over 100 m/s, despite not actually "stalling" until about 30-40 m/s-ish. Granted most of my designs are modified ravenspear Mk3s (some of them VERY heavily modified), and it can't get the nose up on the ground at all!

Edited July 11, 2013 by Tiron

[brickviking]

This is a noob question.... are space planes designed to do a launch off a runway, go into space, then return (hopefully) safely? I'm pretty new to space simulator games in general.

(Post 5)

[Lazro]

Yeah, that's the idea, but me, personally, I just muck about in-atmo

[AlexanderB]

Some folks swear by straight up and down landing gear versus angled off of a circular fuselage to prevent random explosions.

This helps a lot for me, just make sure the thing is level, not nose-up and everything becomes a lot better.

I personally use angled landing gear and place my rear set of gear right behind my CoM. Therefore, when I go to pull up, my plane actually lifts off versus having to ride out the entirety of the runway.

And this too, just make sure you don't hit the engines on the rear on your way up..

[mellojoe]

ANGLE EVERTHING!

Angle your tail fins. Use double tail fins. Angle your main wings slightly up or slightly down. For some reason, having a slight angle balances the left//right forces and keeps everything mostly level. I was having huge, huge problems with planes for the longest time. Someone gave me this advice to angle stuff, and I haven't had nearly as many problems. Most of my plane designs now work, as opposed to nearly always failing. And finally, angle the entire craft on the runway. Make sure the rear landing gear is slightly lower than the front. Do this by either angling the rear landing gear slightly outward or add them to the wings instead of fusealage.

GOOD LUCK!

[Colonel_Panic]

Another thing to keep in mind, just in case... mounting the rear landing gear 'backwards' can also contribute to this problem. If you're at a loss, try flipping them around.

[Rayador]

maybe try to get your center of lift a little more to the back a bit.

i had the same struggle for a long time but then i noticed that the center of lift was too close to my center of mass

maybe this helps

[foamyesque]

This thread is three years old, @Rayador. For anyone playing with modern KSP, BTW, who comes across this, the space-plane veering effect is usually due to the rear gears being lifted off the ground before the nose gears are, resulting in a center of drag well ahead of the center of mass and the attendant yaw instability. In a trike layout you want your main gear just barely behind your CoL.

[Val]

@Rayador While it is generally not a problem to post in an old thread if the topic is still relevant, giving answers or advice to game mechanic questions asked more than 2 years ago is not considered productive.