Fuel Uplift
Fuel to be loaded: the required ramp/block fuel minus fuel already on board, converted from mass to volume using fuel density.
Formula
Variables
Example
Need 4000 kg, 1500 kg on board, SG 0.8: uplift = 2500 kg ÷ 0.8 = 3125 L
How it works
Fuel uplift tells you how much fuel volume needs to be added to the aircraft so that the total fuel on board reaches the required dispatch amount. The first step is to find the missing fuel mass by subtracting the fuel already in the tanks from the required ramp fuel. Because fuel is usually measured into the aircraft by volume, that missing mass is then divided by fuel density to convert kilograms into litres.
When to use it
Use this when planning refuelling before departure, especially at airports where fuel is delivered by volume but flight planning gives fuel requirements in mass. It is also useful for load sheets, dispatch calculations, and checking tanker or bowser quantities.
Worked example, step by step
Required ramp fuel = 5600 kg Fuel already on board = 2100 kg Missing fuel mass = 5600 - 2100 = 3500 kg Fuel density = 0.79 kg/L Uplift volume = 3500 ÷ 0.79 = 4430.38 L Final answer: about 4430 L of fuel must be uplifted
Common mistakes to avoid
- Subtracting density from mass instead of dividing by density
- Using litres when the inputs are in kilograms without converting units
- Forgetting that fuel already on board reduces the amount that still needs to be loaded
Did You Know?
Jet A-1 density varies with temperature (~0.775–0.840 kg/L), so bowsers meter volume in litres while flight plans work in mass — the density figure ties the two together.
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