CHAPTER 2. FUELS AND FUEL ADDITIVES

TB 55-9150-200-24

CHAPTER 2

FUELS AND FUEL ADDITIVES

Section I. TURBINE ENGINE FUELS

2-1. General.

a. Turbine fuels are high-quality fuels covering the general heavy gasoline and kerosine boiling range. They do not

contain dyes or tetraethyl lead.

b. One of the major differences between the wide-boiling and the kerosine types is the fuel volatility. JP-4 type

fuels have a wider boiling range with their initial boiling point considerably below that of kerosine. As a group, these fuels

have lower specific gravities than kerosine types. Wide-boiling range fuels have Reid Vapor Pressures of 2-3 pounds

and flash points of below room temperature. The kerosine type fuels have Reid Vapor Pressures of less then 0.5 pound

and flash points higher then 100° (38° ). Wide-boiling range fuels generally have lower freezing points than kerosine

type fuels.

c. Military specification MIL-T-5624 covers JP-4 and JP-5 fuels. Jet A, Jet Al and Jet B are commercial fuels which

conform to the American Society for Testing Materials specification ASTM-D-1 655.

d. Jet B is a JP-4 type fuel; its freezing point is -56° (-49°C) instead of -72°F (-58°C).

e. JP-5, Jet A, and Jet A-1 are kerosine-type fuels.

f. ASTM Jet A and A-1 differ primarily in fuel freezing point. Jet A is considered suitable down to fuel temperatures

of -36° (-38° ), while Jet A-1 has a minimum requirement of -54° (48°C).

g. JP-4 is a fuel consisting of approximately 65% gasoline and 35% light petroleum distillate, with rigidly specified

properties.

h. JP-5 is a specially refined kerosine having a minimum flash point of 140"F and a freezing point of -51° (-46°C).

i. JP-8 is a specially refined kerosine having a minimum flash point of 110F and a freezing point of -54° (-48° ).

j. JP-4 is the Army standard fuel for turbine engines.

2-2. Identification.

a. Turbine engine fuel specifications, characteristics, freezing points, flash points, ASTM grades and NATO code

numbers are listed in table 2-2.

b. Table 2-3 lists the Army standard, alternate and emergency fuels for fixed and rotary wing turbine powered aircraft.

c. Jet fuels at commercial airports are usually identified by brand names or the American Society for Testing and

Materials (ASTM) grades in lieu of NATO code numbers. Table 2-4 contains a list of current brand name products that

may be encountered in the USA and at overseas commercial airfields.

2-3. Special Precautions.

a. See aircraft manuals for special precautions in using various turbine fuels.

b. The use of kerosine fuels (JP-5 type) in turbine engines dictates the need for observance of special precautions. Both

ground starts and air restarts at low temperature may be more difficult due to negligible vapor pressure. Kerosine fuels

having a freezing point of -40° (-40° ) limit the altitude of a mission to 28,000 feet (8400m) under "standard day"

conditions. Those having a freezing point of -67° (-55° ) limit the altitude of a mission to 33,000 feet (9900m) under

"standard day" conditions. The above altitude limits need not be complied with if an engine fuel heater is used.

Change 2

2-1