Equipment And Tools; Wing Twist And Stabilizer Angle-Of-Incidence; Wing; Wing Skin - Cessna T182 Series Service Manual

MODEL 182 & T182 SERIES SERVICE MANUAL
18-1. STRUCTURAL REPAIR.
18-9. REPAIR MATERIALS.
Thickness of a mate-
rial on which a repair is to be made can easily be de-
18-2. REPAIR CRITERIA.
Although this section
termined by measuring with a micrometer.
In gen-
outlines repair permissible on structure of the air-
eral, material used in Cessna aircraft covered in
craft, the decision of whether to repair or replace a
this manual is made from 2024 aluminum alloy, heat
major unit of structure will be influenced by such
treated to a -T3, -T4, or -T42 condition.
If the type
factors as time and labor available, and by a com-
of material cannot readily be determined, 2024-T3
parison of labor costs with the price of replacement
may be used in making repairs, since the strength
assemblies.
Past experience indicates that replace-
of -T3 is greater than -T4 or -T42 (-T4 and -T42
ment, in many cases, is less costly than major re-
may be used interchangeably, but they may not be
pair. Certainly, when the aircraft must be restored
substituted for -T3).
When necessary to form a part
to its airworthy condition in a limited length of time.
with a smaller bend radius than the standard cold
replacement is preferable.
Restoration of a damaged
bending radius for 2024-T4, use 2024-0 and heat
aircraft to its original design strength, shape, and
treat to 2024-T42 after forming. The repair mate-
alignment involves careful evaluation of the damage,
rial used in making a repair must equal the gauge of
followed by exacting workmanship in performing the
the material being replaced unless otherwise noted.
repairs.
This section suggests the extent of struc-
It is often practical to cut repair pieces from service
tural repair practicable on the aircraft, and supple-
parts listed in the Parts Catalog.
A few components
ments Federal Aviation Regulation, Part 43.
Con-
(empennage tips, for example) are fabricated from
suit the factory when in doubt about a repair not
thermo-formed plastic or glass-fiber constructed
specifically mentioned here.
material.
18-3. EQUIPMENT AND TOOLS.
18-10. WING.
18-4. SUPPORT STANDS.
Padded, reinforced saw-
18-11. DESCRIPTION. The wing assemblies are a
horse or tripod type support stands, sturdy enough to
semicantilever type employing semimoncoque type
support any assembly placed upon them, must be
of structure. Basically, the internal structure con-
used to store a removed wing or tailcone.
Plans for
sists of built-up front and rear spar assemblies, a
local fabrication of support stands are contained in
formed auxiliary spar assembly and formed sheet
figure 18-1.
The fuselage assembly, from the tail-
metal nose, intermediate, and trailing edge ribs.
cane to the firewall, must NOT be supported from
Stressed skin, riveted to the rib and spar structures,
the underside, since the skin bulkheads are not de-
completes the rigid structure.
Access openings
signed for this purpose. Adapt support stands to
(hand holes with removable cover plates) are located
fasten to the wing attach points or landing gear attach
in the underside of the wing between the wing root
points when supporting a fuselage.
and tip section. These openings afford access to
aileron bellcranks, flap bellcranks, electrical wiring,
18-5. FUSELAGE REPAIR JIGS. Whenever a repair
strut attach fittings, control cables and pulleys, and
is to be made which could affect structural alignment,
control disconnect points.
suitable jigs must be used to assure correct align-
ment of major attach points, such as fuselage, fire-
18-12. WING SKIN.
wall, wing and landing gear.
These fuselage repair
jigs are obtainable from the factory.
18-13. NEGLIGIBLE DAMAGE.
Any smooth dents
in the wing skin that are free from cracks, abrasions
18-6. WING JIGS. These jigs serve as a holding fix-
and sharp corners, which are not stress wrinkles and
ture during extensive repair of a damaged wing, and
do not interfere with any internal structure or mech-
locates the root rib, leading edge and tip rib of the
anism, may be considered as negligible damage.
In
wing.
These jigs are also obtainable from the factory.
areas of low stress intensity, cracks, deep scratches,
or deep, sharp dents, which after trimming or stop-
18-7. WING TWIST AND STABILIZER ANGLE-OF-
drilling can be enclosed by a two-inch circle, can be
INCIDENCE.
considered negligible if the damaged area is at least
one diameter of the enclosing circle away from all
18-8. Wing twist (washout) and horizontal stabilizer
existing rivet lines and material edges.
Stop drilling
angle-of-incidence are shown below.
Stabilizers do
is considered a temporary repair and a permanent
not have twist. Wings have no twist from the root to
repair must be made as soon as practicable.
the lift strut station. All twist in the wing panel
occurs between this station and the tip rib. See figure
18-14.
REPAIRABLE DAMAGE. Figure 18-4 out-
18-2 for wing twist measurement.
lines typical repair to be employed in patching skin.
Before installing a patch, trim the damaged area to
half inch radius at each corner, and de-burr.
The
Twist (Washout)
3
°
sides of the hole should lie span-wise or chord-wise.
A circular patch may also be used.
If the patch is
STABILIZER
Angle of Incidence -3
°
30'
patch type of repair; if in an area where flush rivets
18-2