Q15-16. What component in the in-flight refueling
To perform an operational check of the air refueling
system prevents pressure surges in the
probe system, the hydraulic system must be pressurized
hydraulic return system from unlocking the
to 3,000 psi, external electrical power applied, and the
probe-actuating cylinder during flight?
in-flight refueling circuit breaker engaged. Before
actuating the system, ensure that all personnel and
Q15-17. Prior to performing an operational check on
equipment are clear of the area of probe travel. The
the in-flight refueling system, what actions
extension cycle rotates the probe from its stored locked
must you take?
position to an extend locked position.
Q15-18. What should the complete extension and
Position the fuel probe switch to EXTEND. Check
retraction time cycles be when performing an
for proper probe extension and probe locking. If
operational check on the in-flight refueling
operation of the probe is not smooth, check for air in the
system?
system. Position the fuel probe switch to RETRACT
and check for proper probe retraction. The complete
WING FOLD SYSTEMS
extension cycle should be from 5 to 7 seconds, with the
retraction cycle taking from 9 to 11 seconds.
LEARNING OBJECTIVES: Identify the
types of wing fold systems. Identify their
Troubleshooting of the system should include a
components and applicable maintenance re-
thorough knowledge of the malfunction compared to
quirements.
proper system operation and referral to system
schematics and troubleshooting tables provided in the
There are miscellaneous differences in the design
MIM. System rigging, component removal and
a n d o p e r a t i n g c h a r a c t e r i s t i c s o f t h e va r i o u s
installation, and all other maintenance should be in
hydraulically operated systems, and the wing fold
accordance with the procedures and safety precautions
systems are no exception. Basically similar com-
outlined in the MIM.
ponents perform similar functions with only minor
variation in part nomenclature and physical design.
Intermediate maintenance of faulty components
consists of cure-date kit installation and testing in
The wing fold system described in the following
accordance with the "Intermediate Maintenance"
paragraphs will point out some of these differences.
section of the MIM or the applicable (03) overhaul
Refer to the wing fold system schematic shown in
manual.
figure 15-12 as you read the following paragraphs.
Figure 15-12.--Wing fold schematic (spread and locked condition).
15-13
