As far as I can tell, if you select less than 100% fuel in the loadout, the forward fuel tank is filled first, and any remaining fuel goes into the rear tank - so for instance starting with 50% fuel (262 litres) fills the front tank (232 litres) completely, with the rear 292 litre tank then holding 30 litres. I wonder if this is correct, or whether they should be filled evenly? The manual isn't entirely clear, but I think it implies that both tanks should be emptied together until almost empty, and accordingly the 50% fuel loadout results in the centre of gravity being rather far forward compared to a normal situation, possibly making the lack of up trim situation when landing worse. Any thoughts?