Cessna 172S Nav III User Manual

CESSNA
MODEL 172S NAV
III
SECTION 7
AIRPLANE AND SYSTEMS DESCRIPTION
ENGINE (Continued)
IGNITION AND STARTER SYSTEM (Continued)
Ignition and starter operation is controlled by a rotary-type switch
located on the left switch and control panel. The MAGNETOS
switch is labeled clockwise, OFF, R, L, BOTH, and START. The
engine
should be operated on both magnetos (BOTH position)
except for magneto checks. The
Rand L positions are for checking
purposes and emergency use
only. When the MAGNETOS switch is
rotated to the spring
loaded START position, (with the master switch
in the ON position), the starter contactor is closed and the starter,
now energized, will crank the engine. When the switch is
released,
it will automatically return to the BOTH position.
AIR INDUCTION SYSTEM
The engine air induction system receives ram air through an intake
on the lower front portion of the engine cowling. The intake is
covered by an air filter which removes dust and other foreign matter
from the induction air.
Airflow passing through the filter enters an air
box. The air box has a spring-loaded alternate air door. If the air
induction
filter should become blocked, suction created by the
engine
will open the door and draw unfiltered air from inside the
lower cowl area. An open alternate air door will result in an
approximate 10% power loss at full throttle. After passing through
the air
box, induction air enters a fuel/air control unit under the
engine, and is then ducted to the engine
cylinders through intake
manifold tubes.
EXHAUST SYSTEM
Exhaust gas from each cylinder passes through riser assemblies to
a
muffler and tailpipe. Outside air is pulled in around shrouds
which are constructed around the outside
of the muffler to form
heating chambers which
supply heat to the cabin.
(Continued Next Page)
172SPHAUS-00
U.S. 7-35

Cessna 172S Nav III Specifications

General

Brand	Cessna
Model	172S Nav III
Category	Aircrafts
Language	English