anyone who flys the jug even occasionally will know that the main tank appears to be made of cardboard. if anything hits you, its a guaranteed main tank leak. the aux tank is nowhere near as vulnerable and my impression is that the jug's aux is similar in vulnerability to other fighter tanks (ie. probably modelled about right.)
the main and aux tanks are right next to each other under the pilot. they are both armoured, self sealing tanks. I realise this doesnt make them indestructable, but I reckon the main tank drains too quickly as well as being too easy to damage. these fuel tanks are actually part of the armour protection design for the pilot (theres no armour plate around the pilot in the areas covered by the tanks.) theres even some extra protection under the tanks as the jug has an armoured belly for ditching.
Its so vulnerable that I expect to take a main tank hit every other jug sortie so, even though 75% is usually enough, I generally up with 100% just so I can save some in the aux tank to get home with. then I have to burn off the rest to get down to fighting weight.
Im pretty sure something is amiss with the jug main tank damage model - pls have a look at it!
phwoarr!