Re: weight calculation
"The other important calculation for load sheets involves the fuel, whose centre of gravity can move around as it is consumed."
This is similar to driving a tanker of liquid. There are three stages - full, empty and half full, all of which affect speed and braking. To stop all the liquid rushing forward at the red traffic light, or the milk turning to butter, there are baffles in the tank, and / or a series of tanks. Of course, the tanker does not consume the contents on the journey.