shown in figure 7-12. The Fuels Maintenance Officer
of each activity maintains a list of these officially des-
ignated personnel. This list is updated at least quarterly.
2. During defueling operations, maintenance not
directly required to facilitate the defueling operation is
NOT to be performed.
3. Aircraft will be spotted 100 feet from all struc-
tures and other aircraft. Grounding and tiedown pad-
eyes must be available. In addition, at least one fire
extinguisher must be available in the immediate vicinity
of the operation.
4. Only defueled aviation turbine fuel can be re-
issued to aircraft. All defueled AVGAS is downgraded
and not used as aviation fuel.
5. Suspect aviation turbine fuel must be removed
from the aircraft using a defueler only (not a refueler/de-
fueler) and deposited in a designated holding tank.
Ultimate disposition will depend on the results of later
laboratory tests. Every effort should be made to reclaim
off-specification fuel as JP-5, F-76 or fuel oil reclaimed
6. All fuel removed from turbine engine aircraft
is assumed to be a mixture of JP-4 and JP-5. Defueled
turbine fuel must not be returned to JP-5 storage tanks
without first confining the flash point of the fuel to be
140°F or higher.
7. Fuel containing leak-detection dye can be reis-
sued to aircraft of the same squadron as long as the
squadrons requesting official signs a statement that the
fuel is nonsuspect and is safe for use.
Refuelers/defuelers may be used to defuel
dyed fuel. However, this may present logistics
problems since it may take several loads of fuel
to flush the dye out of the refueler/defueler. The
fuel may appear off-color when sampled prior
to issue to another squadrons aircraft.
8. The Fuels Maintenance Officer will personally
decide the disposition of all defueled products.
9. The defueling unit is required to maintain a
flooded suction above the anti-vortex splash plate in its
tank to minimize turbulence and possible ingestion of
air. Historically, a minimum of 1,000 gallons has been
required in the defueling unit to resolve turbulence and
air ingestion problems. Because of the wide variety of
configurations of pump piping systems and tank sizes,
1,000 gallons of product mayor may not be enough. It
is up to the local commands to determine the minimum
amount by using manufacturers technical manuals and
10. The valve(s) that control the flow of fuel from
the tank to the upstream side of the pump remain closed
during defueling operations. This is to prevent the re-
circulation of product in the tank. The valve(s) may be
opened to prime the pump only when the pump is not
11. If, during the defuel operation, the pump starts
to lose prime or cavitates, the operation must be discon-
tinued until the problem is resolved and the fuel super-
visor authorizes a restart. At no time will a restart be
authorized without waiting a minimum of 1 MINUTE
to allow relaxation of any static charges.
12. At no time will defueler tank tops be opened
during defueling operations.
13. Every aircraft defueling operation requires a
minimum of three personnel: the defuel truck operator
(supplied by the fuel division), a nozzle operator (sup-
plied by the squadron), and a fire watch (supplied by the
14. A special log of each defueling operation is
maintained. The following minimum information is
contained in the log:
a. Complete list of all squadron personnel
authorized to sign defuel request forms. This list must
at least quarterly.
All abnormal happenings.
Aircraft buno number.
Grade of product.
Amount of product actually defueled.
Scheduled amount to have been defueled.
Disposition of product.
Times when the defuel operation was
started and completed.
j. Names of the defueler operator and squad-
ron personnel present during the defuel operation.