B737-700
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 397; Flight Crew Type 19000
Confusion; Communication Breakdown; Workload
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
General None Reported / Taken
Airport; Company Policy; Procedure
We received the weight and balance report at pushback. Our fuel gauges showed 18.8; but the wing tanks were only about 8.3 per side; with 2.2 in the center. I mentioned to the Operations Agent that it appeared they didn't completely fill the wing tanks; and she said that ZZZ is an 'over the wing' fueling station and it's because of the fuel density. I have no idea what an 'over the wing' fueling station means; but using 6.5 for fuel density puts us in the range (+/- 2%) of the gauges. No problem here. Now for the confusion.If you add the fuel; add up the fuel in (6;700 lbs.) plus the gallons added (1949 gallons at a fuel density of 6.5 equals 12;669 lbs.) the total is 19;369. However; the FOB on the Fuel summary shows 18;800. The numbers don't add up on the Weight and Balance report. The only way I can get 18.8 on the gauges with 6.7 inbound and 1949 gallons added is with a fuel density of 6.2.The simple math in the fuel summary block of the Weight and Balance Report does not add up.
When looking at the fuel summary box on the weight and balance report; fuel in (6;700 lbs.) plus fuel added (1;949 gallons at fuel density of 6.5 is 12;699 lbs.) equals 19;369 lbs. However; the fuel on board showed 18;800. The numbers don't add up and we couldn't figure out why.
B737-700 Flight Crew reported confusion with the final fuel numbers.