HEADQUARTERS OH-58A, Technical Manual

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TM 55-1520-228-10
(2) Gravity Refueling.
(a) Ground helicopter at receptacle located
adjacent to filler cap on helicopter to filler-nozzle and
remove filler cap.
(b) Rotate inner sleeve clockwise until
sleeve clears port in bottom of fuel receiver. Refer to
figure 2-23.
(c) Position nozzle into port of fuel re-
ceiver.
(d) Fill to specified level.
(e) Remove nozzle and rotate inner sleeve
counterclockwise until gravity refueling port is closed
and flange of inner sleeve is in contact with rivet at base
of receiver cylinder.
(f) Reinstall filler cap.
(g) Disconnect fuel nozzle ground and
rewind hose.
(h) Disconnect fuel nozzle ground and
rewind hose.
(i) Disconnect servicing unit ground at
grounding stake.
e. After Rapid Refueling.
(1) The pilot shall be advised by the refueling
crew that fuel cap(s) are secure and ground cable have
been removed.
(2) Crew members and passengers can enter
aircraft.
f. Defueling and Draining.
(1) Remove fuel cap; rotate inner sleeve
clockwise until end of sleeve clears port in bottom of
fuel receiver.
(2) Insert a suction pickup from a defueler ve-
hicle into fuel filler opening and remove all possible fuel.
(3) To complete defueling, drain remaining
fuel into a suitable container by opening fuel cell sump
drain.
2-79. ENGINE OIL SYSTEM SERVICING.
An engine high oil level coupled with a transmis-
sion low oil level condition indicates a possible
failure of engine gearbox seal(s) which is allow-
ing oil to transfer from the transmission through
the freewheeling unit.
Engine oil tank is located aft of engine and oil cooler fan.
Oil level is checked by a “trapped ball” sight gage on tank
(figure 2-20 and figure 2-21). Ball must be seen floating
in oil for safe oil level. Refer to table 2-1 for authorized
oil.
2-80. TRANSMISSION AND GEARBOX OIL
SYSTEM SERVICING.
a. Transmission. A sight glass located on trans-
mission housing (Figure 2-20 and Figure 2-21) is used
to check oil level in transmission. Oil level must be vis-
ible in sight glass. If oil is visible, additional oil is not
required. If oil is not visible in sight glass, add oil to cen-
ter dot only. Refer to table 2-1 for authorized oil.
b. Gearbox. A sight glass is provided for ease in
checking oil level. Refer to table 2-1 for authorized oil.
Fill to the line for standard gear. Fill to 1/8–inch below
line when high gear or floats are installed.
2-81. HYDRAULIC SYSTEM SERVICING.
The hydraulic reservoir (figure 2-20 and figure 2-21) is
located on forward side of transmission. A sight glass
with ball float or line level is provided to determine low
quantity of fluid in reservoir. Fill to overflow lip in reser-
voir. Refer to table 2-1 for authorized fluid.
2-82. BLADE GRIPS AND PILLOW BLOCKS
SERVICING.
Grease Lubricated Hub. Blade grips and pillow blocks
on main rotor hub are lubricated with grease through
lubrication fittings. The grips have a relief valve located
on each pitch horn.
Change 12 2-63