Inside the fuel tanks of a 747

The B-747 has always been an amazing airplane. What a lot of people don't realize is that the horizontal tail has an optional fuel tank that can hold over 22,000 pounds of fuel. This to keep the CG of the airplane a bit aft for the first part of the trip ie. more economical Then the tail fuel automatically transfers to the main feed tanks at a prescribed time at cruise altitude.
Perhaps even more amazing than that is the fuel system on the B-747/400 model is now computer controlled as opposed to the older versions which had a fuel control panel that would make most professional flight engineers weep with joy.