mutt
Definitely per hour on long range airplanes. (3%)
Taking a nearly empty 744F ex LAX recently the refueller tried to load the ZFW instead of required fuel (360000lbs instead of 270000lbs) he stopped when he could get no more in at about 356000lbs. The new FPL had an increased burn of about 35000lbs. After about 13 hours in the air we still had 90000+ in the tanks on landing. Total endurance 19 hours +
Not a very efficient way to take 11000lbs of freight 6000 miles!
