TM 1-1500-204-23-3
Figure 2-17. Full Grip Push/Pull-Type Coupling
Figure 2-18. Straight Flow Ball / Valve-Type Coupling
Figure 2-19. Ball Lock-Type Coupling
i.
Closed-Circuit Refueling Receptacles. Closed-
Circuit Refueling (CCR) is a system of equipment in which
a special aircraft fill port (receiver) and a special nozzle
mate to form a vapor-proof seal. This system prevents
vapors from escaping at the aircraft fill port, and so
reduces the danger of ignition from static electricity or
engine heat. Use of closed-circuit equipment is especially
,desirable when aircraft are being serviced by the riot
refueling method. Hot refueling is used to reduce the
ground time needed to refuel aircraft, particularly
helicopters used in support of combat operations. Closed
-circuit refueling prevents spills, prevents fuel vapors from
escaping at the aircraft fill port, and prevents dirt, water
or, and other contaminants from entering the aircraft fuel
supply during refueling. These factors contribute to safe
ground operations by reducing fire hazards and contribute
to safe flight operations by protecting the quality of the
fuel used.
(1)
Types. Any closed system of aircraft
refueling depends on two basic pieces of equipment: a
receiver that is mounted in the aircraft, and a nozzle.
These two pieces of equipment are designed for each
other, to mate or lock together before fuel can flow
through them. The Army has two such equipment
systems, the CCR system that: is part of the Forward
Area Refueling Equipment (FAIRE) system and the D-1
pressure system (also called the centerpoint system).
(2)
Inspection. The CC:R receiver as shown in
figure 2-20 is inspected as follows:
(a) Check
receiver
structural
support
assembly for damage, corrosion, and galling of flanges
and webs.
(b) Check retainer four condition, cracks, or
scoring of grooved breakaway tabs. Replace a retainer if
damaged.
(c) Check
receiver
for
condition
and
corrosion, floats for freedom, and fuel nozzle receptacle
for scoring or damage.
(3)
Maintenance. Maintenance of the] CCR
receiver consists of inspection (and replacement if
necessary)
in
accordance
with
the
applicable
maintenance manuals. Scoring and nicks iin the
cylindrical fuel nozzle opening may be repaired by
polishing
out
damage.
Refer
to
the
applicable
maintenance manual for polishing procedures.
j.
Fuel System Troubleshooting. Troubleshooting
should be accomplished in accordance with applicable
aircraft maintenance manuals. A typical troubleshooting
chart and a schematic are shown in table 2-9 and figure 2-
21.
2-33
