View Full Version : DIFFERENCE between jet A1 and JETA in detail
whats the diff btwn Jet A1 and Jet A
Straight & Level
2nd Feb 2011, 06:01
The fuel Freeze Point. Jet A -40 degrees C and Jet A1 -47 degrees C.
Dave Clarke Fife
2nd Feb 2011, 09:59
The only thing to add to the correct answer above is that, as far as I'm aware, you can only find Jet A in North America
The Aeroshell book confirms the info given by the two posters above - and not much else.
Jet A-1
Jet A-1 is a kerosine grade of fuel suitable for most turbine engined aircraft.
It has a flash point minimum of 38°C (100°F) and a freeze point maximum of –47°C. It is widely available outside the U.S.A. The main specifications for Jet A-1 grade (see below) are the UK specification DEF STAN 91-91 (Jet A-1) NATO code F-35, (formerly DERD 2494) and the ASTM specification D 1655 (Jet A-1).
Although developed basically as a military jet fuel, D.Eng RD 2494, issued by the Ministry of Defence, was adopted as the standard UK civil jet fuel. It is now renamed as DEF STAN 91-91 and defines the requirements for a kerosine type fuel (Jet A-1 grade) having a maximum freeze point of – 47°C.
Jet A-1 according to the DEF STAN 91-91 specification is very similar to Jet A-1 defined by the ASTM D 1655 except for a small number of areas where DEF STAN 91-91 is more stringent.
Jet A
Jet A is a kerosine grade fuel, normally only available in the U.S.A. It has
the same flash point as Jet A-1 but a higher freeze point maximum (–40°C).
It is supplied against the ASTM D 1655 (Jet A) specification. Jet A is used within the United States by domestic and international airlines.
but how does it affect the specific gravity of the fuel??..
i set an amount of fuel during refueling but eicas shows diff amount of fuel
hope someone can help me on this
thanks in advance
Old Fella
7th Feb 2011, 07:34
As others have said the primary difference in the two types of fuel is the Freezing Point, Jet A freezing at a higher temperature than Jet A-1 and Jet A-1 has an anti-static additive. There is no measurable difference in the SG of types if they are both at the same temperature. Each has a nominal SG ranging from 0.78 to 0.82 and if you uploaded an amount of fuel which should have resulted in a predetermined weight of fuel on board, after refuel, but had a discrepancy you need to look at why. Did you check SG of fuel in aircraft tanks before beginning to refuel? Did you check SG of uplifted fuel? Are you sure you knew the amount of fuel in tanks before uplift? There are many variables to be considered.