There are three commercial grades of aviation turbine fuel available:
Jet B
Jet A
Jet A1
Jet B
This was the original American aviation turbine fuel. It is what is termed a wide cut, wide range, or
wide distillate as it is manufactured from mixing 70% gasoline with 30% kerosene. This has
several very important effects:
A high vapour pressure (2.6 psi)
A low flash point (below 0°C)
A low fire point (below 0°C)
A low freezing point
A lower SG
Reduced lubricity
Greater fuel loss through evaporation
As can be seen from the first three points, Jet B is a greater fire risk, which reduces crash
survivability. Its use increases the wear in the fuel components, and if it is added to an aircraft
that normally uses Jet A or Jet A1, it requires the fuel control system to be adjusted as its mass
per unit of weight is less. Jet B is not used as a commercial fuel except in areas such as Alaska
or Canada where its lower freezing quality is useful in arctic conditions.