Jet fuel, aviation turbine fuel (ATF), or avtur, is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colourless to straw-coloured in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized 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.
CAS Number, 70892-11-4 (fuel oil no. 5) , 8008-20-6 (kerosene) , 64742-47-8 (Aviation Kerosene)
Properties Appearance, Straw-colored liquid
Density, 775.0–840.0 g/L
Melting point, −47 °C (−53 °F; 226 K)
Boiling point, 176 °C (349 °F; 449 K)
Hazards Safety data sheet, NFPA 704, 220
Flash point, 38 °C (100 °F; 311 K)
Autoignition temperature, 210 °C (410 °F; 483 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa)
Jet fuel is a mixture a variety of hydrocarbons. Because the exact composition of jet fuel varies widely based on petroleum source, it is impossible to define jet fuel as a ratio of specific hydrocarbons. Jet fuel is therefore defined as a performance specification rather than a chemical compound.
Furthermore, the range of molecular mass between hydrocarbons (or different carbon numbers) is defined by the requirements for the product, such as the freezing point or smoke point. Kerosene-type jet fuel (including Jet A and Jet A-1) has a carbon number distribution between about 8 and 16 (carbon atoms per molecule); wide-cut or naphtha-type jet fuel (including Jet B), between about 5 and 15.
Jet fuels are sometimes classified as kerosene or naphtha-type. Kerosene-type fuels include Jet A, Jet A-1, JP-5 and JP-8. Naphtha-type jet fuels, sometimes referred to as "wide-cut" jet fuel, include Jet B and JP-4.
It is very important that jet fuel be free from water contamination. During flight, the temperature of the fuel in the tanks decreases, due to the low temperatures in the upper atmosphere. This causes precipitation of the dissolved water from the fuel. The separated water then drops to the bottom of the tank, because it is denser than the fuel. Since the water is no longer in solution, it can form droplets which can supercool to below 0 °C. If these super cooled droplets collide with a surface they can freeze and may result in blocked fuel inlet pipes. This was the cause of the British Airways Flight 38 accident. Removing all water from fuel is impractical; therefore, fuel heaters are usually used on commercial aircraft to prevent water in fuel from freezing.
There are several methods for detecting water in jet fuel. A visual check may detect high concentrations of suspended water, as this will cause the fuel to become hazy in appearance. An industry standard chemical test for the detection of free water in jet fuel uses a water-sensitive filter pad that turns green if the fuel exceeds the specification limit of 30 ppm (parts per million) free water. A critical test to rate the ability of jet fuel to release emulsified water when passed through coalescing filters is ASTM standard D3948 Standard Test Method for Determining Water Separation Characteristics of Aviation Turbine Fuels by Portable Separometer.
A sailor inspects a sample of JP-5 jet fuel aboard an amphibious transport dock ship. Military organizations around the world use a different classification system of JP (for "Jet Propellant") numbers. Some are almost identical to their civilian counterparts and differ only by the amounts of a few additives; Jet A-1 is similar to JP-8, Jet B is similar to JP-4.Other military fuels are highly specialized products and are developed for very specific applications.
Was an early jet fuel specified in 1944 by the United States government (AN-F-32). It was a pure kerosene fuel with high flash point (relative to aviation gasoline) and a freezing point of −60 °C (−76 °F). The low freezing point requirement limited availability of the fuel and it was soon superseded by other "wide cut" jet fuels which were kerosene-naphtha or kerosene-gasoline blends. It was also known as avtur.
An obsolete type developed during World War II. JP-2 was intended to be easier to produce than JP-1 since it had a higher freezing point, but was never widely used.
Was an attempt to improve availability of the fuel compared to JP-1 by widening the cut and loosening tolerances on impurities to ensure ready supply. In his book Ignition. An Informal History of Liquid Rocket Propellants, John D. Clark described the specification as, "remarkably liberal, with a wide cut (range of distillation temperatures) and with such permissive limits on olefins and aromatics that any refinery above the level of Kentucky moonshiner's pot still could convert at least half of any crude to jet fuel". It was even more volatile than JP-2 and had high evaporation loss in service.
Was a 50-50 kerosene-gasoline blend. It had lower flash point than JP-1, but was preferred because of its greater availability. It was the primary United States Air Force jet fuel between 1951 and 1995. Its NATO code is F-40. It is also known as avtag.
Is a yellow kerosene-based jet fuel developed in 1952 for use in aircraft stationed aboard aircraft carriers, where the risk from fire is particularly great. JP-5 is a complex mixture of hydrocarbons, containing alkanes, naphthenes, and aromatic hydrocarbons that weighs 6.8 pounds per U.S. gallon (0.81 kg/l) and has a high flash point (min. 60 °C or 140 °F). Because some US naval air stations, Marine Corps air stations and Coast Guard air stations host both sea and land based naval aircraft, these installations will also typically fuel their shore-based aircraft with JP-5, thus precluding the need to maintain separate fuel facilities for JP-5 and non-JP-5 fuel. In addition, JP-5 may well have been used by other countries for their military aircraft. Its freezing point is −46 °C (−51 °F). It does not contain antistatic agents. JP-5 is also known as NCI-C54784. JP-5's NATO code is F-44. It is also called AVCAT fuel for Aviation Carrier Turbine fuel.
The JP-4 and JP-5 fuels, covered by the MIL-DTL-5624 and meeting the British Specification DEF STAN 91-86 AVCAT/FSII (formerly DERD 2452), are intended for use in aircraft turbine engines. These fuels require military-unique additives that are necessary in military weapon systems, engines, and missions.
Is a type of jet fuel developed for the General Electric YJ93 jet engine of the XB-70 Valkyrie supersonic aircraft. JP-6 was ideal for the high altitude bomber, being similar to JP-5 but with a lower freezing point ( freezing point: −65 °F ) and improved thermal oxidative stability. When the XB-70 program was cancelled, the JP-6 specification, MIL-J-25656, was also cancelled.
Was developed for the twin Pratt & Whitney J58 turbojet/ramjet engines of the SR-71 Blackbird and has a high flash point to better cope with the heat and stresses of high speed supersonic flight.
Is a jet fuel, specified and used widely by the U.S. military. It is specified by MIL-DTL-83133 and British Defence Standard 91-87. JP-8 is a kerosene-based fuel, projected to remain in use at least until 2025.
The United States military uses JP-8 as a "universal fuel" in both turbine-powered aircraft and diesel-powered ground vehicles. It was first introduced at NATO bases in 1978. Its NATO code is F-34.
Is a gas turbine fuel for missiles, specifically the Tomahawk containing the TH-dimer TetraHydroDiMethylCycloPentadiene produced by catalytic hydrogenation of methylpentadiene dimer.
Is a gas turbine fuel for missiles, specifically the ALCM. It contains a mixture of (in decreasing order) endo-tetrahydrodicyclopentadiene, exo-tetrahydrodicyclopentadiene, and adamantane. It is produced by catalytic hydrogenation of dicyclopentadiene. It superseded JP-9 fuel, achieving a lower low-temperature service limit of −65 °F (−54 °C).
Was developed in 1956 for the Lockheed U-2 spy plane.
Designates a series of experimental boron-containing "high energy fuels" intended for long range aircraft. The toxicity and undesirable residues of the fuel made it difficult to use. The development of the ballistic missile removed the principal application of zip fuel.
Has been working with the USAF to develop a synthetic jet fuel blend that will help them reduce their dependence on imported petroleum. The USAF, which is the United States military's largest user of fuel, began exploring alternative fuel sources in 1999. On December 15, 2006, a B-52 took off from Edwards Air Force Base for the first time powered solely by a 50–50 blend of JP-8 and Syntroleum's FT fuel. The seven-hour flight test was considered a success. The goal of the flight test program was to qualify the fuel blend for fleet use on the service's B-52s, and then flight test and qualification on other aircraft.