B777 Fuel Measuring Stick Manual Notes 2c6u41

B777 Fuel Measuring Stick Manual Notes

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The Model 777-200LR/300ER/FREIGHTER airplane has magnetic type dripless fuel measuring sticks. Eight fuel measuring sticks are installed in each main fuel tank and two fuel measuring sticks are installed in each side of the center fuel tank. In this procedure the fuel measuring sticks are referred to as fuel sticks 1 and 2 for the center fuel tank and fuel sticks 3 thru 10 for the main fuel tanks. Find the airplane attitude (Pitch & Roll): Look at the FUEL QTY 2/2 maintenance page. (Positive pitch is nose up. Positive sense for the roll displayed on the maintenance page is LEFT WING DOWN). The main body of this procedure is a set of conversion tables for the usable fuel load in kilograms (at a fuel density of 0.810 kgs/liter) versus fuel stick readings and airplane attitude in degrees of pitch and roll. Fuel Density Corrections: If the fuel density is not equal to 0.810 kg/liter, then a correction will be needed to obtain the correct stick readings for a given fuel load. The correction factor is defined as follows: Correction factor =[Nominal density (0.810 kg/L)] / [Actual (measured) density]. If SG = 0.780 then Correction Factor = 0.810/0.780 = 1.03846 Density correction for a known fuel quantity that is to be loaded: Corrected Fuel Load = (Correction Factor) x (Desired Fuel Load) If Fuel load 28700kgs on each main tank then Corrected fuel load to be chkd in table = 1.03846 x 28700 = 29804Kgs The certified maximum usable fuel load of each main fuel tank is 31,590 kilograms (39000 liters at a fuel density of 0.810 kg/liter). When the total fuel load is less than 63,180 kilograms put all of the fuel in the main fuel tanks. If additional fuel is required, fill each main fuel tank with 31,590 kilograms of fuel and put the fuel that remains in the center fuel tank. In some cases: 2 sticks will cover a certain Fuel Qty; hence check both sticks on each wing for that particular fig. Eg. 24000Kgs can be chkd at Stick 6 & 7.

To back track from Fuel stick reading to find actual fuel onboard:   

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Find Correction Factor from Fuel SG Eg. Actual Fuel SG = 0.780 then Corrected Factor = 0.810 / 0.780 = 1.03846 Find A/C Pitch and Roll Eg. Pitch = 0.00 & Roll = 0.00 Go to the stick (approx. fig known) from I/B to O/B Eg. When you reach Stick 6 you get a reading of 15.4 And when you reach Stick 7 you get a reading of 6.8 Stick 6 corelates to 24051Kgs from the conversion table Stick 7 corelates to 23987Kgs from the conversion table Avg of the 2 = (24051+23987) / 2 = 24019Kgs Now Actual Fuel Load = Corrected Fuel Load / Correction Factor = 24019 / 1.03846 = 23129Kgs in each main tanks Hence for the example the actual FOB = 23129 x 2= 46258Kgs