Grades and Specifications
Aviation Fuels - Grades, Specifications and Additives
Shell Aviation fuels fall into two basic groups: aviation gasoline, for use in reciprocating or piston engines; aviation turbine fuels (jet fuels), for use in turbo-fan, turbo-jet and turbo-prop engines. There is a third group known as power boost fluids but these are low volume specialist fuels and are not covered in this section (for more details about power boost fluids such as Methmix, contact Shell Aviation via this web site). The various grades and specifications of aviation gasolines and jet fuels are described in the following sections.
All Shell aviation fuels are produced to stringent manufacturing specifications. At every stage between refinery and aircraft tank, fuel quality is checked by sampling and laboratory analysis, to ensure that the fuel conforms to the requirements specified for the grade when it is delivered to the aircraft. The Shell Aviation Quality Assurance System is organised on a world wide basis, made easier because Shell Aviation Service is provided directly in many countries of the world; a representation matched by no other supplier of aviation fuel.
Copies of the specifications cited in our website can be obtained from the following authorities:
DEF STAN specifications
Ministry of Defence
Directorate of Standardisation
65 Brown Street
Glasgow G2 8EX
Phone +44 141 224 2496
Fax +44 141 224 2503
Website: Ministry of Defence website
(All DEF STAN specs are freely available from this web site).
ASTM specifications are published annually in the ASTM Book of Standards, Section 5 (in paper and CD). Copies available from
100 Barr Harbor Drive
Phone +1 610 832 9585
Fax +1 610 832 9555
Website ASTM website
(Specifications are available for a charge.)
US Military Specifications
Department of Defense
Building 4/ Section D
700 Robins Avenue
Phone +1 215 697 2667
Fax +1 215 697 1462
Website Department of Defense website
IATA Guidance Material
IATA issue an excellent guide covering commercial aviation fuels and additives. The 4th Edition has just been published and can be obtained from
800 Place Victoria
PO Box 113
Canada H6Z 1M1
Phone +1 514 874 0202
Fax +1 514 874 2661
Website IATA website
AFQRJOS Check List for Jet A-1
The Joint Systems Check List for Jet A-1 is maintained by Shell Aviation on behalf of the industry. The current edition is Issue 22; please click the link below to download it.
Aviation Jet Fuel Additives
Additives may be included in aviation fuels to improve fuel performance - generally by eliminating undesirable effects - or to meet specific requirements of certain aircraft or airline operators.
Additives may be included in aviation fuels to improve fuel performance - generally by eliminating undesirable effects - or to meet specific requirements of certain aircraft or airline operators. They are added in quantities that are often only measurable in parts per million.
The additive content of jet fuels varies considerably, depending on whether the fuel is for civil or military use. Additive packages for Avgas, on the other hand, are fairly standard. Only additives that have been through a detailed and comprehensive evaluation and approval process are permitted.
Tetra-ethyl lead is added to improve the anti-knock characteristics of Avgas. There are pressures to eliminate this additive on environmental grounds. Alternative ways of boosting the octane rating of Avgas have still to be found however.
Antioxidants (gum inhibitors) must be used in Avgas to prevent the formation of gum and other antioxidation products. Jet fuels, which are inherently more stable than gasolines, may contain them, depending on the treatment process used during manufacture.
A metal deactivator - now rarely used - may be added to nullify the effects of dissolved trace metals, especially copper, which can impair the thermal stability of jet fuels.
Corrosion inhibitors can be used to reduce corrosion in fuel system and improve the lubricity - lubricating properties - of jet fuels.
Fuel system icing inhibitors reduce the freezing point of any water that may be in the fuel system and prevent the formation of ice crystals that could restrict fuel flow. They are mandatory in military Jet but are not used in civil aircraft that have fuel heaters. They may be added to either Jet or Avgas during the fuelling of small aircraft.
Static dissipater additives minimise the hazardous effects of static charges that build up during movement of jet fuels. They are sometimes used in Avgas as well.