Aviation Fuels

Aviation fuels are specialised types of petroleum-based fuel used to power aircraft. They are refined to a higher specification under greater quality control than fuels used in less critical applications, such as heating or road transport and often contain additives to reduce the risk of liquid fuel icing at low temperatures or the explosion of fuel vapour at high temperatures.

Types of aviation fuel:

AVGAS

AVGAS is the most commonly used fuel for piston engines. Some gas turbines can run on AVGAS but it is not the fuel of choice and is normally only used in the case when kerosine or jet fuel is not available. AVGAS contains a highly toxic lead additive in order to achieve high octane ratings and is coloured according to the grade

Avgas 100

The standard high octane fuel for aviation piston engines. It has a high lead content and is dyed green. There are two major specifications for Avgas 100. The ASTM D 910 and UK DEF STAN 91-90. These two specifications are essentially the same but differ over antioxidant content, oxidation stability requirements and max lead content.

Avgas 100LL

This grade is the low lead version of Avgas 100. Low lead is a relative term. There is still up to 0.56 g/litre of lead in Avgas 100LL. This grade is listed in the same specifications as Avgas 100, namely ASTM D 910 and UK DEF STAN 91-90.

Avgas 100LL is dyed blue.

Jet fuel:

jet fuelis a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is clear to straw-colored in appearance.

Civil jet fuel:

The most commonly used fuels for commercial aviation are Jet A and Jet A-1 which are produced to a standardised international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B which is used for its enhanced cold-weather performance.

Jet fuel is similar to kerosene, and has a much higher flash-point than gasoline (e.g. AVGAS) used in piston-engine aircraft. This is an important safety feature, in that the risk of fire in general use, and especially following an accident, is much lower for turbo-jet aircraft.

military jet fuel:

JP-4:

JP-4 used to be the primary jet fuel for the USAF but was phased out in the 1990s because of safety problems. A few airforces around the world still use it but there is very little production.

JP-4 is the military equivalent of Jet B with the addition of corrosion inhibitor and anti-icing additives; it meets the requirements of the U.S. Military Specification MIL-PRF-5624S Grade JP-4. The UK Military specification for this grade is DEF STAN 91-88 AVTAG/FSII (formerly DERD 2454),where FSII stands for Fuel Systems Icing Inhibitor. NATO Code F-40.

JP-8:

JP-8 is the military equivalent of Jet A-1 with the addition of corrosion inhibitor and anti-icing additives; it meets the requirements of the U.S. Military Specification MIL-T-83188D. It is the dominant military jet fuel grade for NATO airforces. The UK also have a specification for this grade namely DEF STAN 91-87 AVTUR/FSII (formerly DERD 2453). NATO Code F-34.

JP-5:

JP-5 is a high flash point kerosine meeting the requirements of the U.S. Military Specification MIL-PRF-5624S Grade JP-5. The UK Military specification for this grade is DEF STAN 91-86 AVCAT/FSII (formerly DERD 2452). This is primarily jet fuel for use in aircraft carriers. NATO Code F-44.

Omid Mohammadi

Maintenance Engineer Of I.R.I

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Aviation Fuels

by Omid Mohammadi time to read: 2 min
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