Cessna 177 SERIES Service Manual

18-1. STRUCTURAL
REPAIR.
(empennage
tips, for
example)
are fabricated
from
thermo-formed
plastic or glass
fiber constructed
18-2. REP.IR
CRITERIA.
Although
this section
material.
outlines
repair permissible
on
structure
of the air-
craft.
the decision
of whether
to repair
or replace
a
18-8. WING
ANGLE-OF-INCIDENCE.
Angle-of-
major unit
of structure
will
be influenced
by
such
incidence
and
wing twist
are listed
in the
following
factors
as time
and labor
available
and by
a com-
chart. The
cantilever
wing
has a uniform
twist
parison
of labor
costs
with
the price
of replacement
from
the root
rib to
the tip
rib.
The amount
of
assemblies.
Past
experience
indicates
that
replace-
twist
between
these two
ribs is
the difference
be-
ment.
in many
cases,
is less
costly
than
major
re-
tween
the angle-of-incidence
at the
root and
the
pair.
Certainly,
when
the aircraft
must
be restored
angle-of-incidence
at the
tip. See
figure
18-2.
to its
airworthy
condition in
a limited length
of time,
replacement
is
preferable.
Restoration
of a
damag-
Angle-of-incidence,
Root-------------
+330
'
ed aircraft
to its original
design
strength,
shape and
Angle-of-incidence,
Tip--------------
+ 30'
alignment
involves
careful
evaluation
of the
damage,
Twist
(Washout)
---------------------
3
°
followed
by exacting
workmanship
in
performing
the
repairs.
This
section
suggests
the
extent of
struc-
18-9.
WING.
tural
repair practicable
on
the aircraft
and supple-
ments
Federal
Aviation
Regulation,
Part 43.
Con-
18-10.
DESCRIPTION.
The
wing is
sheet-metal
suit
the factory
when
in doubt
about
a repair
not
constructed,
with
a single
main
spar,
two fuel
spars,
specifically
mentioned
here.
formed
ribs
and stringers.
The
front
fuel spar
also
serves as an
auxiliary spar and
is the forward wing
18-3. EQUIPMENT
AND TOOLS.
attaching
point.
An inboard
section
forward
of the
main
spar is
sealed to
form an integral
fuel
bay
18-4.
SUPPORT
STANDS.
Padded, reinforced
saw-
area.
The main
spar consists
of
milled spar
caps
horse or
tripod type
support
stands,
sturdy enough
to
and
attaching
fittings joined
by a
web section.
The
support
any assembly
placed
upon them,
must
be used
aft fuel
spar is
a formed
channel.
The
front
fuel
to store
a removed
wing or tailcone.
Plans
for local
spar is
a built-up
assembly consisting
of
a formed
fabrication
of
support
stands are
contained
in
figure
channel,
doubler,
attach
strap
and support
angle.
18-1. The
fuselage assembly,
from
the tailcone
to the
Stressed
skin, riveted
to the ribs,
spars and
string-
firewall,
must
NOT be
supported
from the
underside,
ers,
completes
the wing
structure.
Access
openings
since
the skin
bulkheads
are not
designed
for this
pur-
(hand holes
with removable
cover plates)
are located
pose.
Adapt support
stands
to fasten
to the
wing-
in
the underside
of the
wing between
the
wing root
attach points
or
landing
gear attach-points
when
sup-
and
tip section.
These
openings
afford access
to
the
porting
a fuselage.
flap
and aileron
bellcranks,
flap drive
pulleys,
flap
actuator in
left wing,
flap and aileron
control
cable
18-5.
FUSELAGE
REPAIR
JIGS.
Whenever
a repair
disconnect
points,
fuel
transmitter,
air scoop
con-
is
to be
made
which
could
affect
structural
alignment,
nectors
and
electrical
wiring.
suitable jigs
must be used to assure
correct align-
ment of
major
attach points,
such
as fuselage,
fire-
18-11.
WING
SKIN.
wall,
wing and landing gear.
These fuselage
repair
jigs
are obtainable
from the
factory.
18-12.
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
and
sharp corners,
which
are not
stress
wrinkles
fixture
during
extensive
repair
of a damaged
wing,
and
do not
interfere
with
any internal
structure
or
and
locates
the root
rib, leading
edge
and tip
rib of
mechanism,
may
be considered
as negligible
damage
the
wing. These
jigs
are also
obtainable
from the
in any
area of the
wing.
Outboard
of wing station
factory.
40.00
in areas
of low
stress
intensity,
cracks,
deep
scratches or sharp
dents, which after trimming
or
18-7.
REPAIR MATERIALS.
Thickness
of a mate-
stop
drilling can
be enclosed
by a two-inch
circle,
rial on
which a
repair is
to be made
can easily
be de-
can
be considered
negligible
if
the damaged
area
is
termined
by measuring
with a micrometer.
In gen-
at least one
diameter
of the
enclosing
circle away
eral,
material
used in
Cessna
aircraft
covered
in
from all
existing
rivet lines
and material
edges.
this
manual
is made
from 2024
aluminum
alloy,
heat
The area
on the
lower surface
of
the wing
between
treated to
a -T3,
-T4, or
-T42 condition.
If
the
the
two stringers
adjacent
to the
main spar
is not
type
of material
cannot
readily
be determined,
2024-
considered
low
stress
intensity.
Stop drilling
is
T3
may be used
in making
repairs,
since the strength
considered
a temporary
repair and
a permanent
re-
of -T3 is
greater than
-T4 or -T42
(-T4 and
-T42
pair
should be
made as soon
as practicable.
may
be
used interchangeably,
but they
may
not be
substituted
for -T3.
When
necessary
to form
a part
18-13.
REPAIRABLE
DAMAGE.
Repairs
must not
with a smaller
bend radius
than the standard
cold
be made to
the upper or lower
wing skin
inboard of
bending
radius for 2024-T4,
use 2024-0
and heat
station
40.00 without factory
approval.
However, an
treat
to 2024-T42
after forming.
The
repair mate-
entire
skin may
be replaced
without
factory approval.
rial used in
making a repair
must
equal the gauge
of
Refer to Section
1 for
wing station
locations.
Figure
the material
being repaired
unless
otherwise
noted.
18-4 outlines
typical repairs
to be
employed in
patch-
It is often practical
to cut
repair pieces from
service
ing skin. Before
installing a
patch, trim the
damag-
parts listed in
the Parts Catalog.
A few components
ed area to form
a rectangular
pattern, leaving
at
18-2

Cessna 177 SERIES Specifications

General

Manufacturer	Cessna
Engine Type	Piston
Wingspan	35 ft 6 in (10.82 m)
Seating Capacity	4
Number Built	4, 295
Engine	Lycoming O-360
Horsepower	180 hp
Maximum Takeoff Weight	2, 500 lb (1, 134 kg)