Aviation fuel
Overview
 
Aviation fuel is a specialized type of petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

-based fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

 used to power aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport
Road transport
Road transport or road transportation is transport on roads of passengers or goods. A hybrid of road transport and ship transport is the historic horse-drawn boat.-History:...

, and often contains additives to reduce the risk of icing or explosion due to high temperatures, among other properties.

Most aviation fuels available for aircraft are kinds of petroleum spirit
Petroleum ether
Petroleum ether, also known as benzine, VM&P Naphtha, Petroleum Naphtha, Naphtha ASTM, Petroleum Spirits, X4 or Ligroin, is a group of various volatile, highly flammable, liquid hydrocarbon mixtures used chiefly as nonpolar solvents...

 used in engines with spark plugs, i.e.
Encyclopedia
Aviation fuel is a specialized type of petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

-based fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

 used to power aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport
Road transport
Road transport or road transportation is transport on roads of passengers or goods. A hybrid of road transport and ship transport is the historic horse-drawn boat.-History:...

, and often contains additives to reduce the risk of icing or explosion due to high temperatures, among other properties.

Most aviation fuels available for aircraft are kinds of petroleum spirit
Petroleum ether
Petroleum ether, also known as benzine, VM&P Naphtha, Petroleum Naphtha, Naphtha ASTM, Petroleum Spirits, X4 or Ligroin, is a group of various volatile, highly flammable, liquid hydrocarbon mixtures used chiefly as nonpolar solvents...

 used in engines with spark plugs, i.e. piston and Wankel rotary engines, or fuel for jet turbine engines, which is also used in diesel aircraft engines. Alcohol, alcohol mixtures and other alternative fuels may be used experimentally, but alcohol is not permitted in any certified aviation fuel specification.

Avgas
Avgas
Avgas is an aviation fuel used to power piston-engine aircraft. Avgas is distinguished from mogas , which is the everyday gasoline used in cars and some non-commercial light aircraft...

 is sold in much lower volumes, but to many more individual aircraft, whereas jet fuel
Jet fuel
Jet fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is clear to straw-colored 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...

 is sold in high volumes to large aircraft operated typically by airlines, military and large corporate aircraft.

The Convention on International Civil Aviation
Convention on International Civil Aviation
The Convention on International Civil Aviation, also known as the Chicago Convention, established the International Civil Aviation Organization , a specialized agency of the United Nations charged with coordinating and regulating international air travel...

, which came into effect in 1947, exempted air fuels from tax. Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and the USA oppose a worldwide levy on aviation fuel, but a number of other countries have expressed interest.

Avgas

Avgas (aviation gasoline) is an aviation fuel used to power spark-ignited piston-engine aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

. It can be distinguished from mogas (motor gasoline), which is the everyday petroleum spirit used in cars
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

. Avgas is formulated for stability, safety, and predictable performance under a wide range of environments, and is typically used in aircraft that use reciprocating
Reciprocating engine
A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types...

 or Wankel engine
Wankel engine
The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...

s.
Dyes for the fuel are required in some countries:
Table of Aviation Fuel Types
Country Fuel Lead content Status Dye
Worldwide 80/87 Low lead Phased out, difficult to obtain red
Worldwide 82UL Unleaded Not produced since 2008 purple
Worldwide 100LL Low lead Most commonly used aviation fuel blue
Worldwide 100/130 4 grams of lead per US gallon (1.1 g/l) In process of being replaced by 100LL green
Worldwide 91/96 Discontinued (sometimes produced for races) brown
Worldwide 115/145 Discontinued (mainly military use) purple

Jet fuel

Jet fuel is a clear to straw-colored fuel, based on either an unleaded kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

 (Jet A-1), or a naphtha
Naphtha
Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons, i.e., a component of natural gas condensate or a distillation product from petroleum, coal tar or peat boiling in a certain range and containing certain hydrocarbons. It is a broad term covering among the...

-kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

 blend (Jet B). It is similar to diesel fuel, and can be used in either compression ignition engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

s or turbine engines.

In use

Aviation fuel is often dispensed from a tanker or bowser, which is driven up to parked aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 and helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s. Some airports have pumps similar to filling station
Filling station
A filling station, also known as a fueling station, garage, gasbar , gas station , petrol bunk , petrol pump , petrol garage, petrol kiosk , petrol station "'servo"' in Australia or service station, is a facility which sells fuel and lubricants...

s up to which aircraft must taxi. Some airports also have permanent piping to parking areas for large aircraft.

Regardless of the method, aviation fuel is transferred to an aircraft via one of two methods: overwing or underwing. Overwing fuelling is used on smaller planes, helicopters, and all piston-engine aircraft. Overwing fuelling is similar to car
Čar
Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...

 fuelling — one or more fuel ports are opened and fuel is pumped in with a conventional pump. Underwing fuelling, also called single-point, is used on larger aircraft and for jet fuel exclusively. For single-point fuelling, a high-pressure hose is attached and fuel is pumped in at 40 PSI and a maximum of 45 PSI. Anything higher needs to be stopped, for it can cause damage to the wings. Since there is only one attachment point, fuel distribution between tanks is either automated or it is controlled from a control panel at the fuelling point or in the cockpit. A dead man's switch
Dead man's switch
A dead man's switch is a switch that is automatically operated in case the human operator becomes incapacitated, such as through death or loss of consciousness....

 is also used to control fuel flow. An early use of pressure refuelling was on the de Havilland Comet
De Havilland Comet
The de Havilland DH 106 Comet was the world's first commercial jet airliner to reach production. Developed and manufactured by de Havilland at the Hatfield, Hertfordshire, United Kingdom headquarters, it first flew in 1949 and was a landmark in aeronautical design...

 and Sud Aviation Caravelle
Sud Aviation Caravelle
The Sud Aviation SE 210 Caravelle was the first short/medium-range jet airliner produced by the French Sud Aviation firm starting in 1955 . The Caravelle was one of the more successful European first generation jetliners, selling throughout Europe and even penetrating the United States market, with...

.http://www.flightglobal.com/pdfarchive/view/1952/1952%20-%200274.html

Because of the danger of confusing the fuel types, a number of precautions are taken to distinguish between avgas and jet fuel beyond clearly marking all containers, vehicles, and piping. Avgas is treated with either a red, green, or blue dye, and is dispensed from nozzle
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe via an orifice....

s with a diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

 of 40 millimetre
Millimetre
The millimetre is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length....

s (49 millimetres in the USA). The aperture on fuel tanks of piston-engined aircraft cannot be greater than 60 millimetres in diameter. Jet fuel is clear to straw-colored, and is dispensed from a special nozzle called a "J spout" that has a rectangular opening larger than 60 millimetres in diameter, so as not to fit into avgas ports. However, some jet and turbine aircraft, such as some models of the Astar helicopter, have a fuelling port too small for the J spout, and thus require a smaller nozzle to be installed to be refuelled efficiently.

Energy content

The net energy content for aviation fuels depends on their composition. Some typical values are:
  • BP Avgas 80, 44.65 MJ
    Joule
    The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...

    /kg, density at 15 C is 690 kg/m3
    Cubic metre
    The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...

  • Kerosene type BP Jet A-1, 43.15 MJ
    Joule
    The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...

    /kg, density at 15 C is 804 kg/m3
    Cubic metre
    The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...

  • Kerosene type BP Jet TS-1, (for lower temperatures) 43.2 MJ
    Joule
    The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...

    /kg, density at 15 C is 787 kg/m3
    Cubic metre
    The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...


Chemical composition

Aviation fuels consist of blends of over a thousand chemicals, primarily hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

s (paraffin
Paraffin
In chemistry, paraffin is a term that can be used synonymously with "alkane", indicating hydrocarbons with the general formula CnH2n+2. Paraffin wax refers to a mixture of alkanes that falls within the 20 ≤ n ≤ 40 range; they are found in the solid state at room temperature and begin to enter the...

s, olefins
Alkene
In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...

, naphthenes
Cycloalkane
Cycloalkanes are types of alkanes that have one or more rings of carbon atoms in the chemical structure of their molecules. Alkanes are types of organic hydrocarbon compounds that have only single chemical bonds in their chemical structure...

, and aromatics), as well as additives, such as antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

s and metal deactivators, and impurities. Principal components include n-heptane and isooctane
2,2,4-Trimethylpentane
2,2,4-Trimethylpentane, also known as isooctane, iso-octane, is an organic compound with the formula 3CCH2CH2. It is one of several isomers of octane . This particular isomer is the standard for 100 point on the octane rating scale...

. Like other fuels, blends of aviation fuel used in spark-ignited piston-engined aircraft are often described by their octane rating
Octane rating
Octane rating or octane number is a standard measure of the anti-knock properties of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating...

.

Safety precautions

Any fuelling operation can be very dangerous, and aviation fuel has a number of unique characteristics which must be accommodated. As an aircraft flies through the air, it can accumulate a charge of static electricity
Static electricity
Static electricity refers to the build-up of electric charge on the surface of objects. The static charges remain on an object until they either bleed off to ground or are quickly neutralized by a discharge. Static electricity can be contrasted with current electricity, which can be delivered...

. If this is not dissipated before fuelling, an electric arc can occur, which may ignite fuel vapors. To prevent this, aircraft are electrically bonded to the fuelling apparatus before fuelling begins, and are not disconnected until fuelling is complete. Some regions require the aircraft and/or fuel truck to be grounded, as well.

Aviation fuel can cause severe environmental damage, and all fuelling vehicles must carry equipment to control fuel spills. In addition, fire extinguisher
Fire extinguisher
A fire extinguisher or extinguisher, flame entinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations...

s must be present at any fuelling operation, and airport firefighting forces are specially trained and equipped to handle aviation fuel fires and spills. Aviation fuel must be checked daily and before every flight for contaminants, such as water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 or dirt.

Many airlines now require safety belts be left unfastened should passengers be aboard when refuelling happens.'

See also

  • Aviation biofuel
    Aviation biofuel
    Aviation biofuel is a biofuel used for aircraft. Aviation biofuel is widely considered by the aviation industry to be one of the primary means by which the industry can reduce its carbon footprint. After a multi-year technical review from aircraft makers, engine manufacturers and oil companies,...

  • Avgas
    Avgas
    Avgas is an aviation fuel used to power piston-engine aircraft. Avgas is distinguished from mogas , which is the everyday gasoline used in cars and some non-commercial light aircraft...

  • Environmental impact of aviation
  • Jet fuel
    Jet fuel
    Jet fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is clear to straw-colored 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...

  • Kerosene
    Kerosene
    Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

  • JP-1
    JP-1
    JP-1 was an early jet fuel, specified in 1944 by the U.S. government . It was a pure kerosene fuel with high flash point and a freezing point of −60 °C...

  • JP-4
    JP-4
    JP-4, or JP4 was a jet fuel, specified in 1951 by the U.S. government . It was a 50-50 kerosene-gasoline blend. It has lower flash point than JP-1, but was preferred because of its greater availability. It was the primary U.S. Air Force jet fuel between 1951 and 1995. Its NATO code is F-40...

  • JP-5
    JP-5
    JP-5 or JP5 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 and has a...

  • JP-6
    JP-6
    Jet Propellant 6 is a type of jet fuel developed for General Electric YJ93 jet engine of the XB-70 Valkyrie supersonic aircraft. JP-6 was similar to JP-5 but with a lower freezing point and improved thermal oxidative stability...

  • JP-7
    JP-7
    JP-7 is a jet fuel developed by the U.S. Air Force for use in supersonic aircraft because of its high flash point and thermal stability. It is the fuel used in the Pratt & Whitney J58 engines, used in the Lockheed SR-71 Blackbird. The air compression of Mach 3+ cruising flight generates very high...

  • JP-8
    JP-8
    JP-8, or JP8 is a jet fuel, specified and used widely by the US military. It is specified by MIL-DTL-83133 and British Defence Standard 91-87, and similar to commercial aviation's Jet-A....

  • JPTS
    JPTS
    JPTS stands for Jet Propellant Thermally Stable , and was created specifically for the Lockheed U-2 reconnaissance aircraft....

  • Rocket fuel
  • Swift fuel


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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