Converting pounds to liters required

[Mr. Maximus]

I was just curious what simple formula you guys use to convert pounds to liters required when uplifting fuel?


require 5000 pounds = ? liters.

[pohm1]

Divide the total lbs by 1.76

5000lbs=2841L

[kumul1]

That formula is for Jet A1 and at a Specific Gravity of 0.800 at MSL in ISA conditions.
For AVGAS, divide lbs by 1.58 and that is based on an SG of 0.720 at MSL in ISA conditions.

[Only]

If you want a quick thumb suck calculation, take 5000 devide by half, plus 10%.
5000/2= 2500
2500+10%
=2500+250
=2750 liters

On the smaller turbines that does not take that much fuel the difference is smaller.
This is for Jet A1.

[pithblot]

For Jet A1, the EWAG is multiply lbs by 0.6.
If you want more accuracy, then subtract a further 5 percent.

5000lbs x 0.6 = 3000
3000 - (300/2) = 2850 lt

[FERetd]

Mr. Maximus, this might help wherever you are.


US Gal x 3.785 x sg = Kgs
Imp Gal x 4.546 x sg = Kgs
Litres x sg = Kgs
Kgs x 2.2046 = Lbs
Kgs ÷ 3.785 ÷ sg = US Gal
Kgs ÷ 4.546 ÷ sg = Imp Gal
Kgs ÷ sg = Litres
Lbs ÷ 2.2046 = Kgs

Our fuel gauges were in Kgs, so for Lbs you will need to do one more sum.


e.g. 5000 Lbs ÷ 2.2046 = 2268 Kgs ÷ 0.78(sg) = 2908 litres

An sg of 0.78 is a good average for Jet A1 in warm climates (lower in hotter climates and higher in colder climates)but the refueller should be able to give you the actual sg on the day.

You will then know exactly how many litres you should get - also a good cross reference for fuel gauge accuracy.

I am sorry that despite originally being in a neat chart, Pprune does not seem to like the formatting.

[flyingtool]

This might help.

5000/10% is 500 x 6 is 3000litres + 10%

[FERetd]

Mr. Maximus, as you can see, rules of thumb give a wide range of answers.

Some less, some more. In the case of less, will you have enough? In the case of more, you will certainly have enough, plus more weight and less cash.

So you can pick a number or calculate THE number.

Your choice.

[Journey Man]

A rule of thumb I use is:

REQUIRED (lbs) +10% + 5% then half that amount.

I.e. 5000 lbs + 500 lbs + 250 lbs = 5750

Then 5750 / 2 = 2875 L.


I find working in these few steps quick and easy for mental calculations and gets me within he ballpark for the amounts of fuel I take. YMMV.

[C4]

There is an app for exactly that.. Called "Fuel Uplift". It works very well.

[virgin camel]

The last time I was in old blighty,
1.46£ gave you about 1 liter.

[cavortingcheetah]

There are tables in the Jeppesen if you know where to look for them and if you've ever strayed far enough from electronic back ups to senility so as to be able to flight plan and fly in the good old fashioned hands on manly way so enamoured of beautiful women enveloped in the hot passion of scented Arabian nights.

[extreme P]

http://i68.photobucket.com/albums/i2/pikachu01_2006/FuelConversions_page2.gif (http://s68.photobucket.com/user/pikachu01_2006/media/FuelConversions_page2.gif.html)

[The Maestro]

What works best I find is simply Multiply needed pounds by 0.57

Thus 5000 x 0.57 = 2850 liters

For liters back to pounds, divide by 0.57

Thus 2850/0.57 = 5000 lbs


Hope this helps.

[zac21]

And for small amounts of fuel (Jet). If you need say 500 pounds, ask the refueller for 150 litres per side.

500 X 3 divided by 10 gives you 150 litres per side. Quite accurate in the low numbers but will always give you a tad more and never less.
The higher the amount the less accurate it gets as it gives you more, but it will never give you LESS.:ok:

[DunePrune]

Pounds x 0.4536 = kilograms divided by SG = liters. No rules of thumb. This is exact.