Originally Posted by
tdracer
To be clear, the numbers I posted above are the max fuel weights allowed per the AFM - turns out that's based on a density of .885 which is exceptionally high for jet fuel (but not out of line for gasoline).
Obviously with a more typical .78-.80 density the volume (53,600 gallons, plus another 3,300 gallons for stab fuel) will limit the mass of fuel carried.
That's interesting. My FCOM shows almost exactly the 163 and 173 ton numbers stating "Usable fuel at level attitude, fuel density = 0.8029 kilograms per liter". Not sure if that is written by Boeing or the company.
I think the 173 ton and 163 ton numbers are what you may be able to reasonably expect but the higher AFM values(I added it up to almost 184 tons for the freighter) are the maximum allowable if you happen to come across some very cold fuel available somewhere. Maybe if you are find some Jet A-1 fuel available above ground at -42 degrees C, you could exceed fuel tank weight limitations. I'll let someone else do the calculations.