[FAR] planes NEVER stay straight on the runway

[lukeoftheaura]

Hi,

All my FAR planes go eather left or right off the runway, and whenever I try to correct this, they fall over. any suggestions?

[RainDreamer]

How are you trying to correct that? Might help us figure what is wrong.

My initial suspicion is that it is just your wheels placement.

[Tex_NL]

Please post some pictures. Preferably in the SPH with CoM, CoL and landing gear visible.

[lukeoftheaura]

pics here:

[LethalDose]

Huh. First pass makes think it actually looks really good. Where is the CoM in comparison to the aft gear (a profile pic would be great)?

I would also move the fore gear back to give the plane a higher AoA on the runway.

Other than that, it looks like it should be really stable. How fast is it moving when it starts to veer? Are you using any other mods?

[jake9039]

this also happens to me in stock too!

[lukeoftheaura]

Huh. First pass makes think it actually looks really good. Where is the CoM in comparison to the aft gear (a profile pic would be great)?

I would also move the fore gear back to give the plane a higher AoA on the runway.

Other than that, it looks like it should be really stable. How fast is it moving when it starts to veer? Are you using any other mods?

Only far and kerbpaint.

[Hodo]

pics here:

http://i.imgur.com/cDd99Wxl.jpg

http://i.imgur.com/BynUd0L.jpg

I can say after looking at your plane, the problem looks like your landing gear is the issue.

The nose gear is set at a steep angle and sometimes they don't always go on straight when attached like that. This means the nose gear could be turned ever so slightly left or right which is causing your issue.

The other problem is your main gear, the ones on your wings are probably to far back away from the point of rotation on the aircraft. This is a common problem, the easiest fix is to bump those main gear a bit further forward near the CoM marker. The nose gear you should move back to a more flat area near the nose.

Also check to see if your craft is getting some wing flex on take off that is causing your landing gear to change camber.

[Voculus]

Are your rear wheels too far behind the CoM? Does the plane veer only when pulling up, or does it happen just when getting up to speed?

[lukeoftheaura]

Are your rear wheels too far behind the CoM? Does the plane veer only when pulling up, or does it happen just when getting up to speed?

all the time

[MalfunctionM1Ke]

I think here is your solution http://forum.kerbalspaceprogram.com/threads/52080-Basic-Aircraft-Design-Explained-Simply-With-Pictures

Just scroll down in the first Post until you get to "common landing gear problem"

[Tex_NL]

Looks to me your rear wheels are too far back as several others have already said.

What happens is pretty simple: With your wheels this far back you'll need to go pretty darn fast in order to pull up. The lift from the high speed will start to raise the rear of the plane and the majority of the weight will remain on the single front wheel. Commonly known as wheelbarrowing. Your plane will start to fall over wither to the left or right.

Move the rear wheels forward to just behind the CoM to make it easier to lift the nose at lower speed. Problem solved.

Edited December 10, 2014 by Tex_NL