Specific gravity
Thread Starter
Join Date: Apr 2002
Location: Bristol
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
Specific gravity
what is the specific gravity of jet a1?
i need the value coz i'm doing an assignment on a/c docs, and fuel prices are quoted in gallons, fuel burn is in lbs,
thanks in advance!
stick
i need the value coz i'm doing an assignment on a/c docs, and fuel prices are quoted in gallons, fuel burn is in lbs,
thanks in advance!
stick
Moderator
... but, be wary .... the SG depends on a variety of things including crude source and fuel mass temperature.
For planning purposes I would expect 0.80 to be closer to the mark.
For routine use, either measure a sample with an hydrometer or check with the fuel supplier as they pay by weight so they measure the SG accurately at each delivery.
For planning purposes I would expect 0.80 to be closer to the mark.
For routine use, either measure a sample with an hydrometer or check with the fuel supplier as they pay by weight so they measure the SG accurately at each delivery.
Join Date: Feb 2002
Location: The Sandpit
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
Would be inclined to agree with John here rather than Gengis. Working on the ramp SG checks (carried out before each refuel) shows values of 0.8 and slightly below for most UK conditions.
Did work in Canada one winter and SG's of 0.82 were the norm, but the oat and fuel temp were in the -20 degs region.
Did work in Canada one winter and SG's of 0.82 were the norm, but the oat and fuel temp were in the -20 degs region.
Specific Gravity of Fuel
Not that this is something I normally get excited about driving a Cherokee but I followed the thread and then tried it on the E6B function on my Palm Pilot.
That alleges (at 10 C) that Jet A has an SG of 0.82 (i.e 8.2 lbs / Imp Gal) Jet B an SG of 0.79 and Avgas 0.70.
It needs a temp of 45 C to get Jet A to 0.79 and -30 C to get to 0.85.
I don't suppose (for my purposes) that I need worry too much and I certainly haven't added anything to the thread but as an engineer (civil not aeronautical) this has exercised my brain somewhat - and I thank you all for adding to my store of knowledge.
DGG
That alleges (at 10 C) that Jet A has an SG of 0.82 (i.e 8.2 lbs / Imp Gal) Jet B an SG of 0.79 and Avgas 0.70.
It needs a temp of 45 C to get Jet A to 0.79 and -30 C to get to 0.85.
I don't suppose (for my purposes) that I need worry too much and I certainly haven't added anything to the thread but as an engineer (civil not aeronautical) this has exercised my brain somewhat - and I thank you all for adding to my store of knowledge.
DGG
Moderator
People,
Be wary of ANY "standard" sg figures - unless you are talking comparatively trivial quantities then you must get the actuals from the fuel farm or run a reading yourself.
The real numbers can vary quite a bit. For the GA piston guys and gals this is not too important due to small quantities but do be aware that one can see variations (Australia for example) such a 100/130 down near 0.69 through to 100LL near 0.72.
Be wary of ANY "standard" sg figures - unless you are talking comparatively trivial quantities then you must get the actuals from the fuel farm or run a reading yourself.
The real numbers can vary quite a bit. For the GA piston guys and gals this is not too important due to small quantities but do be aware that one can see variations (Australia for example) such a 100/130 down near 0.69 through to 100LL near 0.72.