Topic Author
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Mass Of Fuel

Sat Nov 04, 2000 3:33 am

Does anyone know the mass in pounds of a gallon of jet fuel? Thanks.
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RE: Mass Of Fuel

Sat Nov 04, 2000 3:41 am

6.7 lb/gallon. 150 gallons per 1000 lbs.
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RE: Mass Of Fuel

Sat Nov 04, 2000 3:45 am

It depends on the density of fuel which can vary.
Average fuel is about 0.8 kg per liter which comes to approx. 6.55 lbs per gallon
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RE: Mass Of Fuel

Sat Nov 04, 2000 6:46 am

There is some variation based on manufacture, type and the temperture of the fuel. A pound of fuel for example will take up less space on a -10 day then on a 70 degree day.

Most of the books I see plan on 6.8 lbs be gallon of Jet A.
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Joined: Tue May 18, 1999 2:41 am

RE: Mass Of Fuel

Sat Nov 04, 2000 7:24 am

Actually it's 0.72kg/l for 100LL fuel. (that's 6lbs/gallon).

I seriously think I just creamed my pants without any influence from any outside variables.
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RE: Mass Of Fuel

Sat Nov 04, 2000 12:35 pm

The weight for a given volume of Jet A changes with temperature. At 15.6C Jet A-1 is 1.78lbs/l, however if the temperature were to rise above this the fuel would expand. In this case 1/l of fuel is going to weigh less than 1.78lbs/l.

This is called the specific gravity of the fuel. It is a measurement taken whenever needed to let the flight crew know how much their fuel weighs. If for example an aircraft took on 40,000L of fuel at 1.6390lbs/l the total weight of fuel is 65,560lbs. If the SG for the fuel was 1.8040lbs/l the total fuel weight would be 72,160lbs. That's a difference of 6600lbs.

This is important for crews when calculating balance fields, or V speeds etc. Hope this answers your question.


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RE: Mass Of Fuel

Sat Nov 04, 2000 1:22 pm

Just as NKP S2 wrote. The nominal weight of Jet A is 6.7 lbs per gallon. This is the average weight when calculating gallons pumped versus pounds indicated or performing a known quantity on a fuel tank with an inop fuel quantity system. Normally at the beginning of the work shift we'll call the fuel tank farm to get the most accurate specific gravity. It varies usually 6.7 - 6.8 lbs per gallon. But as previously said, 6.7 is nominal.
You're only as good as your last departure.

I Fuel

Mon Nov 06, 2000 1:21 am

I fuel 737, md 90's 757. and we use 6.7
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RE: What Is A Gallon?!

Mon Nov 06, 2000 8:48 am

When discussing "gallons", it is important to discriminate between US Gallons and Imperial. In Europe and of course the UK, a gallon is 160 ounces and known as an Imperial Gallon. Because of this potential for confusion, the whole world delivers fuel in Litres, unless of course it is the USA or a protectorate!! Roughly, there are 3.785 litres in a US Gallon at standard temperatures (15 C/59F).

Our company uses metric measure for fuel calculations. It is so much easier!

Best Regards,


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