before filling the corresponding auxiliary tanks.
Secure applicable fuel tank filler cap. Make
sure latch tab on cap is pointed aft.
Disconnect bonding cables from aircraft.
2-91. DRAINING MOISTURE FROM FUEL SYSTEM.
Twelve (12) fuel drains are installed (plus two
drains for the ferry fuel system, when installed) to
remove sediment from the fuel system.
2-92. FUEL TYPES.
Approved fuel types are as follows:
Army Standard Fuels. Army standard fuel is
Alternate Fuels, Army Alternate fuels are
JP-5 and JP-8.
Emergency Fuel. Avgas is an emergency
fuel and subject to 150 hour time limit.
2-93. USE OF FUELS.
Fuel is used as follows:
outlined in Chapter 5. For the purpose of recording, fuel
mixtures shall be identified as to the major component
of the mixture, except when the mixture contains leaded
gasoline. The use of any 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
Use of Kerosene Fuels. The use of
kerosene 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 low vapor pressure. Kerosene fuels
having a freezing point of -40° C (-40° F), limit the
maximum altitude of a mission to 28,000 feet under
standard day conditions.
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.
Fuel Specifications. Fuels having the same
NATO code number are interchangeable. Jet fuels
conforming to ASTM D-1655 specification may be used
when MIL-T-5624 fuels are not available. This usually
occurs during cross-country flights 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 experienced. 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 specific
gravity may possibly require fuel control adjustments; if
so, the recommendations of the manufacturers of the
engine and airframe are to be followed.
2-94. 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. Overfilling 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:
Open the access door on the upper
cowling to gain access to the oil filler cap and dipstick.
A cold oil check is unreliable. If
possible, check oil within 10 minutes
after engine shutdown. If over 10
minutes have elapsed, motor the
engine for 40 seconds, then check. If
over 10 hours have elapsed, start the
engine and run for 2 minutes, then
check. Add oil as required. Do not
If oil level is over 2 quarts low, motor
or run engine as required, and service as necessary.
Remove oil filler cap.
Insert a clean funnel, with a screen
incorporated, into the filler neck.
Replenish with oil to within 1 quart
below MAX mark or the MAX COLD on dipstick