TM 1-1510-262-10
2-94. FUEL TYPES.
Approved fuel types are as follows:
a. Army Standard Fuels. Army standard fuel is JP-8.
b. Alternate Fuels. Army Alternate fuels are JP-4 and JP-5.
c. Emergency Fuel. Avgas is an emergency fuel and subject to 150-hour time limit.
Table 2-11.
Standard, Alternate, and Emergency Fuels
EMERGENCY FUEL
ENGINE
ARMY STANDARD FUEL
ALTERNATE TYPE
TYPE
*MAX. HOURS
PT6A
MIL-T-83133
MIL-T-5624
150
MIL-G-5572
Grade JP-8
Grade JP-4/5
Any AV Gas
MIL-T-5624
Grade JP-4
* Maximum operating hours with indicated fuel between engine overhauls (TBO).
2-95. USE OF FUELS.
Fuel is used as follows:
a. Fuel limitations. Fuel limitations are outlined in Chapter 5. For the purpose of recording, fuel mixtures shall
be identiied as to the major component of the mixture, except when the mixture contains leaded gasoline. The use
of emergency fuels other than standard will be entered in the FAULTS/REMARKS column of DA Form 2408-13,
Aircraft Maintenance and Inspection Record, noting the type of fuel, additives, and duration of operation.
b. Use of Kerosene Fuels. The use of kerosene fuels (JP-5 type) in turbine engines dictates the need for ob-
servance of special precautions. Both ground starts and air restarts at low temperature may be more dificult due to
low vapor pressure. Kerosene fuels having a freezing point of -40C (-40F), limit the maximum altitude of a mission
to 28,000 feet under standard day conditions.
c. Mixing of Fuels in Aircraft Tanks. When changing from one type of authorized fuel to another, for example
JP-4 to JP-5, it is not necessary to drain the aircraft fuel system before adding the new fuel.
d. Fuel Speciications. Fuels having the same NATO code number are interchangeable. Jet fuels conforming
to ASTM D-1655 speciication may be used when MIL-T-5624 fuels are not available. This usually occurs during
cross-country lights where aircraft using NATO F-44 (JP-5) are refueling with NATO F-40 (JP-4) or Commercial
ASTM Type B fuels. Whenever this condition occurs, the engine operating characteristics may change in that lower
operating temperature, slower acceleration, lower engine speed, easier starting, and shorter range may be experi-
enced. The reverse is true when changing from F-40 (JP-4) fuel to F-44 (JP-5) or Commercial ASTM Type A-I fuels.
Most commercial turbine engines will operate satisfactorily on either kerosene or JP-4 type fuel. The difference in
speciic gravity may possibly require fuel control adjustments; if so, the recommendations of the manufacturers of
the engine and airframe are to be followed.
2-96. SERVICING OIL SYSTEM.
An integral oil tank occupies the cavity formed between the accessory gearbox housing and the compressor inlet
case on the engine. The tank has a calibrated oil dipstick and an oil drain plug. Avoid spilling oil. Any oil spilled
must be removed immediately. Use a cloth moistened in solvent to remove oil. Overilling may cause a discharge
of oil through the accessory gearbox breather, during engine operation until a satisfactory level is reached. Service
oil system as follows:
2-95
