64.18 Turbine Engine Fuel Systems

64.18.2 Describe the distinguishing features of aviation turbine fuel (AVTUR/Jet A1).

AVTUR, commonly known as Jet A-1, is a kerosene-based fuel used in turbine engines.

Its distinguishing features include:

Appearance:
Jet A-1 is normally clear and colourless to pale straw in appearance.

Lower volatility:
It evaporates less readily than aviation gasoline. This reduces vapour formation and makes it less susceptible to vapour lock.

Higher flash point:
Jet A-1 has a minimum flash point of approximately 38°C, making it less flammable during normal handling than aviation gasoline. However, its vapour can still ignite under suitable conditions.

Low freezing point:
Jet A-1 has a maximum freezing point of approximately −47°C, allowing it to remain usable at the low temperatures encountered during high-altitude flight.

Greater density:
Jet A-1 is heavier than aviation gasoline, with a typical density of approximately 0.8 kg per litre. The exact density varies with temperature and fuel batch.