Cessna T188C - Page 373

MODEL
188
&
T188
SERIES
SERVICE
MANUAL
17-52.
REPAIRABLE
DAMAGE.
Skin patches
shown
17-57.
REPAIRABLE
DAMAGE.
Fuselage
skin re-
in figure
17-4 may
be used to
repair skin
damage.
pairs
may
be accomplished
in the
same manner
as
Access
to the dorsal
area of the
fin may be gained
by wing
skin repairs
outlined in paragraph
17-16.
removing
the horizontal
closing rib
at the bottom of
Stringers,
formed skin
flanges, bulkhead
channels,
the
fin. Access
to the internal
fin structure is
best and
similar parts
may be repaired
as shown in
gained by removing skin attaching rivets on one side figure 17-5.
of the
rear spar
and
ribs,
and springing
back the
skin. Access
to the stabilizer
structure may
be
17-58. DAMAGE
NECESSITATING
REPLACEMENT
gained by removing
skin attaching
rivets on
one side
OF PARTS. Fuselage
skin major
repairs may
be
of the rear spar and ribs,
and springing back the
accomplished in the same
manner as the wing re-
skin. If the damaged area would
require a repair
pairs outlined in paragraph 17-17.
Damaged fittings
which
could not
be made between
adjacent
ribs,
or
should be
replaced.
a repair
would
be
located
in an area
with
compound
curves,
see
the
following
paragraph.
17-59.
FIREWALL
DAMAGE
may
be
repaired
by
17-53. DAMAGE NECESSITATING
REPLACEMENT
removing the damaged
material and splicing in a
OF PARTS. If the damaged
area would require a
new section of material.
The new portion should
patch which would not be made between adjacent ribs, be lapped over the old material, sealed with Pro-
or the repair
would be located in an area
with com- Seal #700 (Coast
Pro-Seal Co., Chemical
Division,
pound
curves, complete
skin
panels
should be
re-
2235 Beverly
Blvd
Los Angeles,
California),
com-
placed. Ribs and spars may be repaired, but re- pound or equivalent, and secured with stainless
placement
is generally preferable. Where
damage steel rivets.
Damaged or deformed angles
and
is extensive, replacement of the entire assembly is stiffeners may be repaired as shown in figure 17-10,
recommended.
or they may be
replaced. A
severely damaged
fire-
wall
should
be replaced
as
a unit.
Seal
around
all
17-54. FUSELAGE.
(Except tubular structure.)
holes and openings
in firewall with Pro-Seal
#700
compound
or equivalent.
17-55.
The
fuselage
tallcone
is of semimonocoque
17-60.
ENGINE
COWLING
construction, consisting of formed bulkheads, longi-
tudinal
stringers,
reinforcing
channels,
and
skin
17-61.
REPAIR
OF
COWLING
SKINS.
If
extensively
platings.
The
fuselage
skins
and
supporting
struc-
damaged,
complete
sections
of
colwing
should
be
re-
tures
which
surround
the tubular
structure,
from the
placed.
Standard
insert-type
skin patches,
however,
tailcone
to
the firewall,
are
not stress
members
but
may be
used If
repair
parts are
formed
to fit.
Small
are
essentially
just
covering.
The tubular
structure
cracks
may
be stop-drilled
and dents
straightened
Is
discussed
later
in this
section.
if they
are
reinforced
on the
inner
side
with
a doubler
of the same material.
17-56. NEGLIGIBLE
DAMAGE.
Refer to
paragraph
17- 15.
Mild
corrosion
appearing
upon
alclad
surfaces
17-62.
REPAIR
OF
REINFORCEMENT
ANGLES
does not
necessarily
indicate
incipient
failure
of
the
Cowl
reinforcement
angles,
if damaged,
should
be
base
metal.
However,
corrosion
of all
types
should
replaced.
Due
to their
small
size
they
are easier
be
carefully
considered,
and
approved
remedial
ac-
to replace
than
to
repair.
tion
taken. Small
cans appear
in the skin structure
of all
metal
airplanes.
It is
strongly
recommended,
17-63.
BONDED
FORWARD
ACCESS
DOORS.
however,
that wrinkles
which appear
to have
origin-
ated
from
other sources,
or
which
do not
follow
the
17-64.
REPAIRABLE
DAMAGE.
Bonded
doors
may
general
appearance
of the
remainder
of the
skin
b repaired
by the same
method
used
for
rivited
panels,
be thoroughly
investigated.
Wrinkles
over
structure.
Rivets
are
a satisfactory
substitute
for
stringers
which
disappear
when
the rivet
pattern
is
bonded
seams
on
the assemblies.
The strength
of
removed
may
be
considered
negligible.
However,
the bonded
seams
may
be
replaced
by a
single
3/32,
the stringer
rivet
holes may
not align
perfectly
with
2117-AD
rivet per
running
inch of bonded
seam.
the skin
holes
because
of a permanent
"set"
in the
The
standard
repair
procedures
outlined
in AC43.
stringer.
If this
is apparent,
replacement
of the
13-1
are
also
applicable
to bonded
doors.
stringer
will usually
restore the original
strength
characteristics
of the area.
Wrinkles
occuring on
open areas
which
disappear
when the
rivets
at the
17-66.
FUSELAGE
TUBULAR
STURCTURE.
edge
of the sheet
are
removed,
or
a wrinkle
which
is
hand-removable,
may
often
be repaired
by
the addi-
17-67.
The fuselage
tubular
structure,
illustrated
in
tion
of a 1/2
x 1/2 x .060-inch
2024-T4
extruded
an-
figure
17-11,
is fabricated
of chrome-molybdenum
gle, riveted
over
the wrinkle
and
extended
to
within
4130
steel
aircraft
tubing
welded
together.
Gussets,
1/16
to
1/8-inch
of
the nearest
structural
members,
channels,
angles,
tabs and
fittings,
also of
4130
steel,
Rivet
pattern
should
be
identical
to
the existing
manu-
are welded
to the
tubular
assembly
to complete
the
factured
seam
at the
edge of
the sheet.
Neglible
dam-
structure.
The structure
is not heat
treated.
age to stringers,
formed
skin flanges,
bulkhead chan-
nels,
and
like parts
is
similar
to that
for the
wing
17-68.
GENERAL
CONSIDERATIONS.
Federal
stringers
and ribs, outlined in paragraph
17-19. Aviation
Regulations, Part 43, list persons
author-
ized
to perform
repairs
and outlines
standards
of
performance. Given in these standards of perfor-
17-11