Ah we were taught only to use the bottom two on the wing tanks. This is probably why. Of course they do this for every student flight where it's really only nec

Ah we were taught only to use the bottom two on the wing tanks. This is probably why. Of course they do this for every student flight where it's really only necessary before the first flight of the day. So I think this plays into it (not wanting to waste too much fuel). Also the 7ml is not my figure. The "shotglass" is usally more than half full. I agree 7ml is not a lot.