400 - 76 = 324 kgs
From the report, "Using an average fuel consumption of 200 kg/hr" (3.33 kg/min)
… about 97 minutes!
20:45 to 22:22 = 1hr 37 minutes!
I think you have to recalculate that. With the XFER pumps OFF from starting engines you cant get as low as 74kg in the main tank.
Just remember your groundrun after the ASB ( supplytank fuel sensor check )
skadi