Calculated Fuel Needed - Now you need more to compensate for fuel Weight

[stevehudd]

Is this Title true? Even though I have always just used a planner, I always wandered as 120,000lbs is a lot of weight in fuel so do you now not need to add extra fuel to compensate?:8

[Hand Solo]

Yes, always has been, although it should be included in your planning tables. If you want to take extra above the planned fuel then you need to factor in how much more you need just to carry that extra to destination.

[stevehudd]

Thanks for clearing that up :)

[Intruder]

Our computer-generated flight plans also have a fuel adjustment table for payloads up to 10 Tonnes above and below planned payload. It is expressed in Kg fuel per Tonne of payload. Beyond +/- 10T, a new flight/fuel plan has to be calculated.

I suppose you could do a double iteration to come closer to finding out how much extra fuel is burned to carry the extra fuel, but the numbers get very small very quickly.

[barit1]

You can always search for "Breguet Range Equation" to see the effect of the range variables.

[stevehudd]

Thanks guys, I am only a PPL'er but I use Level - D sim 767, Do the uk do KG instead of Lb's now. Only asking as I did flying in florida and did Lbs and the 767 i was using was in Lbs

[blackmail]

hello barit 1,
"breguet range" in NM =[ L/DxTAS ]/TSFC x ln(TOW/LANDING WEIGHT)
for b738 : to account for additional fuel burn : 2.5% of the additional fuel x flight time(hrs). e.g. 3500kg extra for a 2hrs flight = 0.025x3500x2.0=175kg:rolleyes:

kind regards,
bm