Jet fuel is a kerosene-type fuel made up of hydrocarbon molecules. Typically a colorless or straw-colored liquid, the two most widely used categories are Jet A and Jet A-1. The main difference between the two is the freeze point, which is defined as the temperature where wax crystals disappear under laboratory testing.
Jet A is used mainly in the United States. Developed in the 1950s, this fuel has a freeze point of minus 40ºC or below. Jet A-1 is defined with a lower freeze point of minus 47ºC or below, and is the most commonly used Jet fuel in locations outside of the US. Although the two fuels are manufactured to different specifications, they can be used interchangeably. A key difference lies in the additives contained within the fuel. Par exemple, Jet A does not usually contain
