Cessna T188C - Page 229

MODEL
188 &
T188 SERIES
SERVICE MANUAL
3. Drain line at airbox
exhaust crossover pipe and
heat exchanger section.
c. Remove safety
wire from mounting bolts and
is available for cabin
heat and windshield defrost air
bolts securing
airbox
to fuel-air control
unit, and
remove airbox
with its gasket.
11B-51. INSPECTION.
Since exhaust systems
of
d.
Reverse the preceding steps for
installation, this type
are subject to burning, cracking
and gen-
using all new
gaskets, align per
figure 11B-4.
eral
deterioration
from alternate
thermal stresses
e. Rig throttle
and mixture controls according
to and vibrations, inspection
is important and should
paragraph 11A-53.
be accomplished every 100
hours of operation. Also.
f. Connect air
inlet temperature probe wiring.
a thorough inspection
of the engine exhaust system
should
be made
to detect cracks
causing leaks
which
11B-43. CLEANING AND INSPECTION. (Refer to could result in loss of engine power. To inspect the
Section 11A.)
engine
exhaust system, proceed as
follows:
a. Remove engine cowling as required so that ALL
11B-44. INDUCTION AIR FILTER
REPLACEMENT.
surfaces of the exhaust assemblies
can be visually
a. Remove
left
hand engine
cowling,
inspected.
b. Remove
wing nut on air filter, and
remove
NOTE
filter cover.
c. Change filter element according to criteria in Especially check the areas adjacent to welds
section 2 or more often in dusty climates. and slip joints. Look for gas deposits in
surrounding area, indicating that exhaust
11B-44A.
INSTALLATION OF INLET
DUCTS (Refer gases
are escaping through a crack
or hole
to Section 11A), or around the slip joints.
11B-45. ALTERNATE AIR VALVE CONTROL b. After visual inspection, an air leak check should
RIGGING. (See figure
llA-5.)
be made on the exhaust
system as follows:
a. Pull Alternate Air Control out approximately 1. Attach the pressurs side of an industrial
3. 375"
vacuum
cleaner
to the
tailpipe
opening,
using
a
b. Remove engine cowling
as necessary for access.
rubber plug to effect
a seal as required.
It is possible to rig the rotary air valve with the
cowling
installed.
NOTE
c. Rotate valve sleeve until alternate air port is
fully open. The inside of the vacuum cleaner hose should
d. Clamp control housing so sleeve arm (56) clears be free of any contamination that might be
housing (53) end by at least 1/8". blown into the engine exhaust system.
e. Connect control wire (55) to arm (56).
f. Push alternate air
control in and insure approxi-
2. With vacuum cleaner
operating, all joints
mate 1/8" cushion. in the exhaust system may be checked manually by
feel, or by using a soap and water solution and
11B-46. PROPELLER CONTROL. (Refer to watching for bubbles. All joints should be free of
Section 13.) air leaks.
11B-47. STARTING
SYSTEM. (Refer to
Section 11.)
NOTE
11B-48. COOLING SYSTEM. Ram air for cooling At annual inspection of aircraft, LH exhaust
enters through an intake opening in the front portion tee & exhaust risers should be removed and
of the engine cowling. It is directed around the cyl- a visual inspection made of internal hea. ex-
inders with
baffles,
and is exhausted
through
fixed
changer.
cooling air exits on both side cowlings at the aft end.
A third exit is located
underneath on the rear sections
11B-52. TURBOCHARGING
SYSTEM. A turbo-
of both left and right cowlings. A cooling lip is in- charged engine exhibits some different character-
stalled in the lower outlet which facilitates engine istics from a normally aspirated engine. Following
cooling by directing
airflow outward from the
aircraft is a description
pointing to some of the differing
contour at that point. characteristics. This turbocharged configuration
differs also, because of the Inflight-fixed waste gate.
11B-49. EXHAUST SYSTEM. (See figure 11B-7. ) Please read the following carefully to insure com-
plete
understanding
of the
operational
characteristics.
11B-50. DESCRIPTION. The
exhaust gases from
a. Induction air is taken in
through an opening in
each cylinder pass thru riser assemblies into an ex- the left side of the cowling, ducted through an auto-
haust manifold. This manifold connects the risers motive type paper air filter, through the rotary air
to the turbocharger turbine inlet, and to the ground valve (closed position) and into the compressor sec-
adjustable wastegate. As the gases pass through the tion of the turbocharger, where it is compressed by
turbine, some of its energy turns the turbine wheel the turbine driven centrifugal compressor.
which in
turn drives the compressor wheel.
The b. The pressurized
air is directed through
the
waste gate shunts
a preset percent of exhaust to
the throttle body where
it is metered according to throttle
tailpipe, thereby, controlling turbocharger speed, i.e. valve setting, into the induction manifold, and into
output. A heater, consisting of a shroud around the the individual cylinders.
Revision 1 11B-15