Montague

Heh, actually in flight, you don't need to have the clunk move to the front of the tank. And in practice it doesn't.

When you dive, there's enough G-force to hold the fuel at the back of the tank, so your plane runs out of air before your engine runs out of fuel. Holding the plane still and nose-low isn't something that happens in flight unless you really work at it.

And yes, you CAN take most models up really high, and do a shallow dive long enough with a nearly empty tank to get the engine to die. But it's actually rather hard to do, and not worth worrying about.

I have several tanks where the clunk can't move to the front of the tank except during a sudden stop, and when it does, it gets stuck. Those planes do as good a job as any at emptying the tank.

(I also don't run the tank dry with the engine anyway. I land with a little fuel in the tank most of the time, the pump the tank empty. When pumping out if I want the last bit of fuel, I'll hold the plane up at a slight angle, which helps, but I usually don't bother).