SECTION 7
CESSNA
AIRPLANE & SYSTEMS DESCRIPTIONS
MODEL 172RG
equipped with a spring-loaded retaining arm which will help rotate the
window outward and hold it there. An openable window is also available
for the right door, and functions in the same manner as the left window. I:
required, either window may be opened at any speed up to 164 KIAS. The
cabin top windows (if installed), rear side windows, and rear window are
of
the fixed type and cannot be opened.
CONTROL LOCKS
A control lock is provided to lock the aileron and elevator control
surfaces to prevent damage to these systems by wind buffeting while the
airplane is parked. The lock consists of a shaped steel rod with a red meta]
flag attached to it. The flag is labeled CONTROL LOCK, REMOVE
BEFORE STARTING ENGINE. To install the control lock, align the hole
in the top of the pilot's control wheel shaft with the hole in the top of the
shaft collar on the instrument panel and insert the rod into the aligned
holes. Installation of the lock will secure the ailerons in a neutral position
and the elevators in a slightly trailing edge down position. Proper
installation of the lock will place the red flag over the ignition switch. In
areas where high or gusty winds occur, a control surface lock should be
installed over the vertical stabilizer and rudder. The control lock and any
other type of locking device should be removed prior to starting the engine.
ENGINE
The airplane is powered by a horizontally-opposed, four-cylinder,
overhead-valve, air-cooled, carbureted engine with a wet sump oil system.
The engine is a Lycoming Model O-360-F1A6 and is rated at 180 horsepower
at 2700 RPM. Major accessories include a starter, belt-driven alternator,
and propeller governor on the front of the engine and dual magnetos, fuel
pump, vacuum pump, and full-flow oil filter on the rear of the engine.
ENGINE CONTROLS
Engine manifold pressure is controlled by a throttle located on the
center area of the switch and control panel. The throttle operates in a
conventional manner; in the full forward position, the throttle is open, and
in the full aft position, it is closed. A friction lock, which is a round knurled
disk, is located at the base of the throttle and is operated by rotating the
lock clockwise to increase friction or counterclockwise to decrease it.
The mixture control, mounted near the propeller control, is a red knob
with raised points around the circumference and is equipped with a lock
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1 July 1979
CESSNA
SECTION 7
MODEL 172RG
AIRPLANE & SYSTEMS DESCRIPTIONS
button in the end of the knob. The rich position is full forward, and full aft is
the idle cut-off position. For small adjustments, the control may be moved
forward by rotating the knob clockwise, and aft by rotating the knob
counterclockwise. For rapid or large adjustments, the knob may be moved
forward or aft by depressing the lock button in the end of the control, and
then positioning the control as desired.
ENGINE INSTRUMENTS
Engine operation is monitored by the following instruments: oil
pressure gage, oil temperature gage, cylinder head temperature gage,
tachometer, manifold pressure gage and fuel pressure
gage.
An economy
mixture (EGT) indicator and carburetor air temperature gage are also
available.
The oil pressure gage, located on the left side of the instrument panel,
is operated by oil pressure. A direct pressure oil line from the engine
delivers oil at engine operating pressure to the oil pressure gage. Gage
markings indicate that minimum idling pressure is 25 PSI (red line), the
normal operating range is 60 to 90 PSI (green arc), and maximum pressure
is 100 PSI (red line).
Oil temperature is indicated by a gage below the oil pressure gage. The
gage is operated by an electrical resistance type temperature sensor which
receives power from the airplane electrical system. Gage markings
indicate the normal operating range (green arc) which is 100°F (38°C) to
245°F (118°C), and the maximum (red line) which is 245°F (118°C).
The cylinder head temperature gage, adjacent to the oil temperature
gage, is operated by an electrical-resistance type temperature sensor on
the engine which receives power from the airplane electrical system. Gage
markings indicate the normal operating range (green arc) which is 200°F
(93°C) to 500°F (260°C) and the maximum (red line) which is 500°F (260°C).
The engine-driven mechanical tachometer is located on the lower right
side of the pilot's control column. The instrument is calibrated in incre-
ments of 100 RPM and indicates both engine and propeller speed. An hour
meter below the center of the tachometer dial records elapsed engine time
in hours and tenths. Instrument markings include a normal operating
range (multiple width green arc) of 2100 to 2700 RPM, and a maximum (red
line) of 2700 RPM.
The manifold pressure gage is located on the lower left side of the
pilot's control column. The gage is direct reading and indicates induction
air manifold pressure in inches of mercury. It has a normal operating
range (green arc) of 15 to 25 inches of mercury.
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