Aristocles:
I never said that it was a big issue. In fact our laptop PC`s allow us to compute for a non-normal fuel distribution anyway if one so wishes I just posted to put the info out there for those who might want to learn. By the way, have you never emptied the outer tanks on the ground after a tanking sector when the conditions are conducive to upper wing frost and then ground tranferred to put warm fuel back into the outers to avoid having to de-ice?