SECTION 7
CESSNA
AIRPLANE & SYSTEMS DESCRIPTIONS
MODEL 172RG
TABLE OF CONTENTS (Continued)
Page
Hydraulic System............................................................................................7-27
Brake System ................................................................................................... 7-27
Electrical System............................................................................................7-29
Master Switch........................................................................................... 7-29
Avionics Power Switch...........................................................................7-31
Ammeter.....................................................................................................7-31
Alternator Control Unit and Low-Voltage Warning Light
7-31
Circuit Breakers And Fuses ...................................................................7-32
Ground Service Plug Receptacle .......................................................... 7-33
Lighting Systems ............................................................................................ 7-33
Exterior Lighting ..................................................................................... 7-33
Interior Lighting...................................................................................... 7-33
Cabin Heating, Ventilating And Defrosting System ...............................7-35
Pitot-Static System And Instruments.........................................................7-35
Airspeed Indicator ................................................................................... 7-37
Vertical Speed Indicator .........................................................................7-38
Altimeter.................................................................................................... 7-38
Vacuum System And Instruments.............................................................. 7-38
Attitude Indicator..................................................................................... 7-38
Directional Indicator............................................................................... 7-38
Suction Gage............................................................................................. 7-40
Stall Warning System .................................................................................... 7-40
Avionics Support Equipment .......................................................................7-40
Audio Control Panel ....................................................................................... 7-40
Transmitter Selector Switch ..................................................................7-42
Audio Selector Switches .........................................................................7-42
Corn Auto Audio Selector Switch ......................................................... 7-43
Corn Both Audio Selector Switch ......................................................... 7-43
Auto Audio Selector Switch ...................................................................7-44
Annunciator Lights Brightness and Test Switch ..............................7-44
Sidetone Operation...................................................................................7-44
Microphone - Headset Installations ............................................................ 7-45
Static Dischargers...........................................................................................7-46
7
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2
1 July 1979
CESSNA
SECTION 7
:MODEL 172RG
AIRPLANE & SYSTEMS DESCRIPTIONS
INTRODUCTION
This section provides description and operation of the airplane and its
systems . Some equipment described herein is optional and may not be
installed in the airplane. Refer to Section 9, Supplements, for details of
other optional systems and equipment.
AIRFRAME
The airplane is an all-metal, four-place, high-wing, single-engine
,airplane equipped with retractable tricycle landing gear and designed for
;general utility purposes.
The construction of the fuselage is a conventional formed sheet metal
bulkhead, stringer, and skin design referred to as semimonocoque. Major
items of structure are the front and rear carry-through spars to which the
wings are attached, a bulkhead with attaching plates at the base of the
forward doorposts for the lower attachment of the wing struts, and the
orgings and structure for the retractable main landing gear in the lower
leftportion of the fuselage center section. Four engine mount stringers are
also attached to the forward doorposts and extend forward to the firewall. A
tunnel incorporated into the fuselage structure below the engine, in front of
he firewall, is required for the forward retracting nose wheel.
The externally braced wings, containing the fuel tanks, are
constructed of a front and rear spar with formed sheet metal ribs, doublers, and
stringers . The entire structure is covered with aluminum skin. The front
;pars are equipped with wing-to-fuselage and wing-to-strut attach
fittings. The aft spars are equipped with wing-to-fuselage attach fittings, and
ire partial-span spars. Conventional hinged ailerons and single-slot type
flaps are attached to the trailing edge of the wings. The ailerons are
constructed of a forward spar containing balance weights, formed sheet
metal ribs and "V" type corrugated aluminum skin joined together at the
railing edge. The flaps are constructed basically the same as the ailerons,
with the exception of balance weights and the addition of a formed sheet
metal leading edge section.
The empennage (tail assembly) consists of a conventional vertical
stabilizer, rudder, horizontal stabilizer, and elevator. The vertical
stabilizerconsists of a forward and aft spar, formed sheet metal ribs and
reinforcements , a wrap-around skin panel, formed leading edge skin, and a
dorsal . The rudder is constructed of a formed leading edge skin containing
tinge halves, a center wrap-around skin panel, ribs, an aft wrap-around
;kin panel which is joined at the trailing edge of the rudder by a filler strip,
anda ground adjustable trim tab at the base of the trailing edge. The top of
L July 1979
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