Cessna 1969-1976 172 Series Service Manual page 67

4-5. REPAIR. A damaged wing may be repaired in
accordance with instructions outlined in Section 18,
which supplements F e d e r a l Aviation Regulation, P a r t
43. Extensive r e p a i r s of wing skin and structure a r e
best accomplished by using the wing alignment repair
jig, which may be obtained f r o m Cessna. The wing
jig s e r v e s not only
as a
holding fixture, making work
on the wing easier, but also a s s u r e s absolute align-
ment of the repaired wing.
4-6. INSTALLATION.
a. Hold wing in position and install bolts, bushings,
washers and nuts attaching wing s p a r s to fuselage
fittings.
as
marked.
b. Install bolts, spacers, and nuts to secure upper
and lower ends of wing s t r u t to wing and fuselage fit-
tings.
c. Route flap and aileron cables, using guide wires.
(See note in paragraph 4-4. )
d. Connect:
l t i o n s outlined in Section 12).
Be s u r e eccentric bushings a r e positioned
1. Electrical wires a t wing root disconnects.
2 . Fuel lines
at
wing root. (Refer to precau-
3. Pitot line ( if left wing is being installed).
4. Wing leveler vacuum tube, if installed,
at
wing root.
e. Rig aileron system. (Section 6.)
f. Rigflap system (Section 7 . )
g. Refuel wing tank and check for leaks. (Refer to
precautions outlined in Section 12.
)
h. Check operation of wing tip lights and landing
and taxi lights thru 1970 Models.
i. Check operation of fuel gage.
j. Install wing root fairings.
I
NOTE
Be s u r e to insert soundproofing panel in wing
gap, if such a panel was installed originally,
before replacing wing root fairings.
k. Install all wing inspection plates, interior panels
and upholstery.
4- 7. ADJUSTMENT (CORRECTING WING-HEAVY"
CONDITION. ) (Refer to figure 4-1. ) If considerable
control wheel p r e s s u r e is required to keep the wings
level in normal flight, a wing-heavy condition exists.
a.
Remove wing fairing s t r i p on the wing-heavy
side of the aircraft.
b. Loosen nut (10) and rotate bushings (8) simul-
taneously until the bushings a r e positioned with the
thick side of the eccentrics up. This will lower the
trailing edge of the wing, and decrease wing-heavi-
n e s s by increasing angle-of-incidence of the wing.
Be s u r e to rotate the eccentric bushings simul-
taneously.
stroy the alignment between the off-center
bolt holes in the bushings, thus exerting
a
shearing force on the bolt, with possible dam-
age to the hole in the wing spar.
Rotating them separately will de-
C.
Tighten nut and reinstall fairing strip.
d. Test-fly the aircraft. If the wing-heavy condi-
tion still exists, remove fairing s t r i p on the "lighter"
wing, loosen nut, and rotate bushings simultaneously
until the bushings a r e positioned with the thick side of
the eccentrics down.
edge of the wing, thus increasing wing-heaviness to
balance heaviness in the opposite wing.
test flight.
4-8. WING STRUTS. (Refer to figure 4-2.)
4-9. DESCRIPTION. Each wing has
a
single lift
strut which transmits
a
part of the wing load to the
lower portion of the fuselage. The strut consists of
a
streamlined tube riveted to two end fittings for at-
tachment
at
the fuselage and wing.
This will r a i s e the trailing
e. Tighten nut, install fairing strip, and repeat
4-10. REMOVAL AND INSTALLATION.
a.
Remove s c r e w s f r o m strut fairings and slide
b. Remove fuselage and wing inspection plates at
c. Support wing securely, then remove nut and bolt
d. Remove nut, bolt, and spacer used to attach
e. Reverse preceding steps to install strut.
fairings along strut.
strut junction points.
securing strut to fuselage.
strut to wing, then remove strut from aircraft.
4-11. REPAIR. Wing strut repair is limited to r e -
placement of tie-downs and attaching parts. A badly
dented, cracked, or deformed wing strut should be
replaced.
4-12. FIN. (Refer to figure 4-3.)
4-13.
DESCRIPTION. The fin is primarily of metal
construction, consisting of ribs and spars covered
with skin. Fin tips a r e of ABS construction. Hinge
I
brackets
at
the fin r e a r spar attach the rudder.
4-14. REMOVAL. The vertical fin on the Models
172 and F172 may be removed without f i r s t removing
the rudder. However, for access and ease of hand-
ling, the rudder may be removed by following proce-
dures outlined in Section 10.
a.
Remove fairings on either side of fin.
b. Disconnect flashing beacon lead,
tail
navigation
light lead, antennas and antenna leads, and rudder
cables, if rudder has not been removed.
NOTE
The flashing beacon electric lead that routes
into the fuselage may be cut, then spliced (or
quick-disconnects used)
at
installation.
c. Remove s c r e w s attaching dorsal to fin.
d. Disconnect elevator cable from elevator bell-
e. Remove bolts attaching fin r e a r spar to fuselage
f.
Remove bolts attaching fin front s p a r to fuselage
g. Retain any shims installed between the r e a r spar
crank.
fitting.
bulkhead, and remove fin.
of the fin and the fuselage fitting.
Remove upper elevator stop bolts.
Change 2 4-3