Fuel Consumption Question

[TwStD]

Ok, I'm running a stock, unmodded instance of KSP. I am trying to build a decent atmospheric plane to get me to the other side of the planet for a survey mission, and I believe I have built a plane that is capable of that. The only problem I am having is with fuel consumption changing the balance and center of mass on the plane, causing it to become uncontrollable about two thirds of the way through the flight. Is there a way, without modding the game, to tell the engines which tank to pull fuel from so that I can keep it balanced for center of mass? Thanks in advance.

Edited February 4, 2015 by TwStD

[vexx32]

The only easy way to do this is to find a part that has fuel crossfeed disabled, and attach the engines to your plane using that part to block flow from the tanks to the engines. Then, you can attach a fuel line from the tank you want to be drawing fuel from to each engine.

You'll probably need to experiment a fair bit to get the result you want, though. Fuel flow rules can be a mite tricky to figure out.

[Bilfr3d]

If my memory serves me correctly there was a user that posted a huge investigating on fuel flow methods... I cannot remember where it is though.

[LordFjord]

Fuel flow rules have been researched extensively here.

Its no easy topic though.

However, what you can do to fix it easily, just pump around some fuel from the back to the front of your plane. You can do this in flight. That should help to stabilize it again and you won't need to rebuild or to change it.

Google tossed me this

that explains how to do that.

[Red Iron Crown]

Another option you might consider is disabling the tanks that you want drained last, then reenable them as needed.

[TwStD]

Thanks for the help guys. I was unaware of the fuel pumping mechanic. I should be able to pump fuel out of the rear tanks before the forward tanks deplete, giving me balance while maintaining access to fuel per the fuel flow rules.