This chapter will cover characteristics of fuels and
quality surveillance. The fuels that the ABF will most
commonly work with at naval activities are automo-
tive gasoline (MOGAS) and jet engine (JP) fuels. You
need to know the basic characteristics of these fuels to
understand the need for safety and caution in handling
them. This chapter includes the basic characteristics
of gasolines and jet engine fuels that fuel-handling
personnel should know.
PROPERTIES OF FUELS
LEARNING OBJECTIVE: Describe the charac-
teristics and properties of the fuels commonly
handled by the ABF.
Motor gasolines and jet engine fuels are petroleum
products manufactured from crude oil by oil refiner-
ies. Through distillation, the crude oil is separated into
fractions, which are groups of compounds having
boiling points within a given range. Nearly all of the
distillate fractions may be used as fuels. These frac-
tions (which include gasoline, kerosene, jet fuels, and
diesel fuel) are known as distillate fuels.
Distillate fuels are flammable liquids. This means
they burn when ignited. Under proper conditions they
even explode with forces similar to those of TNT or
dynamite. Death can result if the vapors of any of these
fuels are inhaled in sufficient quantities. Serious skin
irritation also can result from contact with the fuels in
the liquid state.
In the liquid form petroleum fuels are lighter than
water, and in the vapor form they are heavier than air.
So any water present in these fuels usually settles to
the bottom of the container. On the other hand, vapors
of these fuels, when released in the air, also tend to
remain close to the ground. This increases the danger
to personnel and property. From safety and health
standpoints, motor gasolines and jet engine fuels must
be handled with caution.
SOURCE OF ENERGY
Petroleum fuel is a liquid containing heat energy
that turns into mechanical energy in an engine. An
engine fuel must be made to suit the engine in which
it is to be used. In the case of the aircraft engine, the
fuel must also be suitable for the aircraft under a wide
variety of operating conditions. There is no such thing
as a universal fuel since a fuel suited for a gasoline
engine does not work in a diesel engine and vice versa.
MOGAS (NATO Code Number F-46) is a gaso-
line composed of a mixture of highly volatile liquid
hydrocarbons designed for use in internal combustion
engines. It is composed of the lower boiling elements
of petroleum and is explosive and volatile, and must
be handled with extreme caution.
The octane number of MOGAS is
The octane number is a numerical measure of the
antiknock properties of motor fuel, based on the per-
centage of volume of isooctane in a standard reference
fuel. For example, a motor fuel that produces the same
degree of knocking as a standard reference fuel con-
taining 80 percent isooctane has an octane number of
80. Octane number also may be referred to as octane
rating. Because MOGAS has a low octane rating, it
may cause knocking in engines.
JP-5 (NATO Code Number F-44) is best described
as a kerosene-type jet fuel. It was developed to provide
a higher flash-point fuel that could be stored on board
more safely than either gasoline or earlier jet fuels.
Like gasoline, it is a mixture of liquid hydrocarbons
produced from petroleum. However, JP-5 is composed
of higher boiling components than gasoline and is not
as explosive and volatile as gasoline. JP-5 is the only
grade of jet fuel authorized for fueling aircraft on