Greetings, all.As I sit here in a college class without access to my manuals at home, I am boggled that searches all over the internet turn up nothing on the Jet Fuel conversion of Pound/Gallon. I know that Jet Fuel has a certain weight per gallon.Can someone here answer what that figure is? I know Avgas and Jet fuel are different. I am particularly looking for Jet Fuel here for airliner use.Here is the issue I have that created the problem question:Flying a 757 for 1 hour burns 7,000 pounds of fuel (for the engine config I am using) -- so how many gallons of fuel do I order?

6.7lbs/gal

Knikolaes,The specific density for fuel is dependant on the temperature of the fuel. To make your headache worse I think it is about 0.86 kg/l (that is kilograms per liter) at 15 degrees Celsius or something.Cheers,

Pilots like to use weight (not volume) because it is independent of temperature.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

MANY MANY thanks to all. At least a rough close number was all I needed. Nothing precise. i always overestimate when it comes to fuel anyway (I'd rather have too much than too little), but i try to rely as little on "fuel planners" that "do the work for me" as possible. i like to be able to learn how to do things. After all, you never know when the flight computer will break down or malfunction -- them we'd need our brains to do the calculating.I knew about the density and temp thing. I never gave it much thought, though, until i was trying to convert these weights for a project I was working on. On average, i do use the default 15C for calculations in FS. The real world, however -- well -- that gets more complicated.

a rough approximation would be.drop the zeros and multiply by 8 to get an "aside" burn.ie you burn 1000 total lbs, is roughly 10x8=80 gallons a side or 160 gallons total.used this in the beech 1900 all the time. needed 1200 more pounds of gas, add 100 gallons a side (12x8=96 then round up).

Innnteresting. Writing that down.