Cessna SkyHawk 172 1966 User manual

THERE ARE MORE CESSNAS FLYING THAN ANY OTHER MAKE
II
CESSNA
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OWNER'S MANUAL
WORLD"S LARGEST PRODUCER OF GENERAL AVIATION AIRCRAFT SINCE 1956

PERFORMANCE - SPECIFICATIONS
GROSS WEIGHT . . . . .
SPEED:
Top Speed at Sea Level . . .
Cruise, 75% Power at 7000 ft
RANGE:
Cruise, 75% Power at 7000 ft
36 Gal. No Reserve
Optimum Range at 10, 000 ft
36 Gal. No Reserve
RATE OF CLIMB AT SEA LEVEL
SERVICE CEILING
TAKE-OFF:
Ground Run .
Total Distance Over 50-Foot Obstacle.
LANDING:
Landing Roll . . . . . . . . . . . .
Total Distance Over 50-Foot Obstacle.
EMPTY WEIGHT (Approximate) .
BAGGAGE .......... .
WING LOADING: Pounds/Sq Foot
POWER LOADING: Pounds/HP
FUEL CAPACITY: Total ....
OIL CAPACITY: Total . . . . .
PROPELLER: Fixed Pitch (Diameter)
ENGINE:
Continental Engine No.
Horse Power .....
MODEL 172
2300 lbs
138 mph
130 mph
. 550 miles
4. 2 hours
130 mph
. 670 miles
6.6 hours
102 mph
. 645 fpm
13, 100 ft
865 ft
15 25 ft
. 520 ft
1250 ft
1260 lbs
120 lbs
13. 2
15.9
. 39 gal.
. 8 qts
. 76 inches
. O-300-C*
. 145
SKYHAWK
2300 lbs
139 mph
131 mph
555 miles
4. 2 hours
131 mph
670 miles
6. 6 hours
102 mph
645 fpm
13, 100 ft
865 ft
1525 ft
520 ft
1250 ft
1330 lbs
120 lbs
13.2
15.9
39 gal.
8 qts
76 inches
O-300-D
145
*The Model Fl 72, which is manufactured by Reims Aviation S. A., Rei ms (Marne) France, is
identical to the 172 except that it is powered by an O-300-D engine, m. anufaeturcd under license
by l~olls Hoyce, Crewe, England. All 172 information in this manual pertains to the F172 as well.
D61G-1J RA.ND 300 8/71

CONGRATULATIONS ........ .
Welcome to the ranks of Cessna owners! Your Cessna has been designed
and constructed to give you the most in performance, economy, and com-
fort. It is our desire that you will find flying it, either for business or
pleasure, a pleasant and profitable experience.
This Owner's Manual has been prepared as a guide to help you get the
most pleasure and utility from your Model 172/Skyhawk. It contains in-
formation about your Cessna's equipment, operating procedures, and
performance; and suggestions for its servicing and care. We urge you
to read it from cover to cover, and to refer to it frequently.
Our interest in your flying pleasure has not ceased with your purchase of
a Cessna. World-wide, the Cessna Dealer Organization backed by the
Cessna Service Department stands ready to serve you. The following
services are offered by most Cessna Dealers:
FACTORY TRAINED PERSONNEL to provide you with courteous
expert service.
FACTORY APPROVED SERVICE EQUIPMENT to provide you
with the most efficient and accurate workmanship possible.
A STOCK OF GENUINE CESSNA SERVICE PARTS on hand
when you need them.
THE LATEST AUTHORITATIVE INFORMATION FOR SERV-
ICING CESSNA AIRPLANES, since Cessna Dealers have all
of the Service Manuals and Parts Catalogs, kept current by
Service Letters and Service News Letters, published by Cessna
Aircraft Company.
We urge all Cessna owners to use the Cessna Dealer Organization to the
fullest.
A current Cessna Dealer Directory accompanies your new airplane. The
Directory is revised frequently, and a current copy can be obtained from
your Cessna Dealer. Make your Directory one of your cross-country
flight planning aids; a warm welcome awaits you at every Cessna Dealer.

I Jl."72 I
ii
lght o( airplane
*Maximum ":..r depressed and
with nose g tat•ng beacon
an optiooal ro l
Installed.
PRINCIPAL
DIMENSIONS

TABLE OF CONTENTS
======================Page=
SECTION I - OPERATING CHECK LIST .............. 1-1
SECTION II - DESCRIPTION AND
OPERATING DETAILS ...................... 2-1
SECTION Ill - OPERATING LIMITATIONS ............. 3-1
SECTION IV- CARE OF THE AIRPLANE ............ 4-1
OWNER FOLLOW-UP SYSTEM ........................... 4-8
SECTION V - OPERATIONAL DATA ...................... 5-1
SECTION VI - OPTIONAL SYSTEMS ...................... 6-1
ALPHABETICAL INDEX ........................................ lndex-1
This manual describes the operation and performance of both
the Cessna Model 172 and the Cessna Skyhawk. Equipment
described as "Optional" denotes that the subject equipment
is optional on the Model 172. Much of this equipment is
standard on the Skyhawk model.
iii

b.
C.
d.
e.
f.
EXTERIOR
Turn on master switch and check fuel quanfl
tily indicators, then turn master switch off.
Check ignition switch "OFF".
Check fuel selector valve handle "BOTH ON."
On first flight of day and after each fueling,
pull out strainer drain knob for about four
seconds, to clear fuel strainer of possible
water and sediment.
Remove control wheel lock.
Check baggage door for security.
@)
a.
b.
C.
d.
e.
12\ a. Remove rudder gust lock, if installed. 15' a.
~ b. Disconnect tail tie-down. ~
b.
-@ a. Check main wheel tire for proper inflation.
b. Inspect airspeed static source hole on side of
fuselage for stoppage (left side only). f6\
c. Disconnect wing tie-down. ~
Figure 1-1.
iv
Note
Visually check fuel filler
caps, inspection plates,
and general aircraft condi-
tion during waJk .. around
inspection.
If night flight is planned,
check operation of all
lights, and make sure a
flashlight is available.
Check oil level. Do not operate with lesc,
than six quarts. Fill for extended flight.
Check propeller and spinner for nicks and
security.
Check nose wheel strut and tire for proper
inflation.
Disconnect tie-down rope.
Make vh,ual check to insure that fuel strainer
drain valve is closed after draining operation.
Remove pitot tube cover, if installed, and
check pitot tube openin1,t for stoppage.
Check fuel tank vent opening for stoppage.
Sameas ®·

~ §ection
OPERATING CHECK LIST
One of the first steps in obtaining the utmost performance, service,
and flying enjoyment from your Cessna is to familiarize yourself with
your airplane's equipment, systems, and controls. This can best be done
by reviewing this equipment while sitting in the airplane. Those items
whose function and operation are not obvious are covered in Section II.
Section I lists, in Pilot's Check List form, the steps necessary to
operate your airplane efficiently and safely. It is not a check list in its
true form as it is considerably longer, but it does cover briefly all of
the points that you should know for a typical flight.
The flight and operational characteristics of your airplane are normal
in all respects. There are no "unconventional" characteristics or opera-
tions that need to be mastered. All controls respond in the normal way
within the entire range of operation. All airspeeds mentioned in Sections
I and II are indicated airspeeds. Corresponding calibrated airspeed may
be obtained from the Airspeed Correction Table in Section V.
BEFORE ENTERING THE AIRPLANE.
(1) Make an exterior inspection in accordance with figure 1-1.
BEFORE STARTING THE ENGINE.
(1) Seats and Seat Belts -- Adjust and lock.
(2) Brakes -- Test and set.
(3) Radios and Rotating Beacon -- "OFF."
(4) Fuel Selector -- "BOTH ON."
1-1

STARTING THE ENGINE.
(1) Master Switch -- "ON".
(2) Carburetor Heat -- Cold.
(3) Mixture -- Rich.
(4) Primer -- 2-5 strokes (depending on temperature).
(5) Throttle -- Open 1/8''.
(6) Propeller Area -- Clear.
(7) Ignition Switch -- "BOTH".
(8) Starter -- "Engage.
BEFORE TAKE-OFF.
(1) Flight Controls -- Check.
(2) Trim Tab -- "TAKE-OFF'' setting.
(3) Cabin Doors -- Latched and locked.
(4) Throttle Setting -- 1700 RPM.
(5) Engine Instruments -- Check.
(6) Carburetor Heat -- Check operation.
(7) Magnetos -- Check (75 RPM maximum differential between mag-
netos).
(8) Flight Instruments and Radios -- Set.
(9) Suction Gage -- Check (4. 6 to 5. 4 inches of mercury).
TAKE-OFF.
NORMAL TAKE-OFF.
(1) Wing Flaps -- 0°
(2) Carburetor Heat -- Cold.
(3) Power -- Full throttle (applied smoothly).
(4) Elevator Control -- Lift nosewheel at 60 MPH.
(5) Climb Speed -- 85 MPH.
MAXIMUM PERFORMANCE TAKE-OFF.
(1) Wing Flaps -- 0°
(2) Carburetor Heat -- Cold.
1-2

(3) Brakes -- Apply.
(4) Power -- Full throttle.
(5) Brakes -- Release.
(6) Elevator Control -- Slightly tail low.
(7) Climb Speed -- 65 MPH (with obstacles ahead).
CLIMB.
NORMAL CLIMB.
(1) Airspeed -- 80 to 90 MPH.
(2) Power -- Full throttle.
(3) Mixture -- Full rich (unless engine is rough).
MAXIMUM PERFORMANCE CLIMB.
(1) Airspeed -- 80 MPH at sea level to 77 MPH at 10,000 feet.
(2) Power -- Full throttle.
(3) Mixture -- Full rich (unless engine is rough).
CRUISING.
(1) Power -- 2200 to 2700 RPM.
(2) Trim Tab -- Adjust.
(3) Mixture -- Lean.
LET-DOWN.
(1) Mixture -- Rich.
(2) Power -- As desired.
(3) Carburetor Heat -- As required to prevent carburetor icing.
BEFORE LANDING.
(1) Mixture -- Rich
(2) Fuel Selector -- "BOTH ON."
1-3

(3) Carburetor Heat -- Apply full heat before closing throttle.
(4) Airspeed -- 70 to 80 MPH (flaps up).
(5) Wing Flaps -- As desired.
(6) Airspeed -- 65 to 75 MPH (flaps down).
NORMAL LANDING.
(1) Touchdown -- Main wheels first.
(2) Landing Roll -- Lower nosewheel gently.
(3) Braking -- Minimum required.
AFTER LANDING.
(1} Wing Flaps - - Up
(2) Carburetor Heat -- Cold.
SECURE AIRCRAFT.
1-4
(1) Mixture -- Full lean.
(2) All Switches -- Off.
(3) Brakes -- Set.
(4) Control Lock -- Installed.

~ !!!iection
DESCRIPTION AND OPERATING DETAILS
The following paragraphs describe the systems and equipment whose
function and operation is not obvious when sitting in the airplane. This
section also covers in somewhat greater detail some of the items listed
in Check List form in Section I that require further explanation.
FUEL SYSTEM.
Fuel is supplied to the engine from two aluminum tanks, one in each
wing. From these tanks, fuel flows by gravity through a selector valve
and a strainer to the carburetor.
Refer to figure 2-1 for fuel quantity data. For fuel system servicing
information, refer to Lubrication and Servicing Procedures in Section IV.
I
FUEL QUANTITY DATA (U.S. GALLONS)
USABLE FUEL
ADDITIONAL UNUSABLE
TOTAL
FUEL
TANKS
NO.
ALL FLIGHT USABLE
FUEL
FUEL
VOLUME
CONDITIONS
(LEVEL FLIGHT) (LEVEL FLIGHT) EACH
LEFT WING
l 18.0
gal. 1.0 gal.
0.5 gal. 19.5 gal.
RIGHT WING
l 18.0
gal.
1.0 gal. 0.5 gal.
19.5 gal.
Figure 2-1.
2-1

2-2
LEFr FUEL TANK RIGHT FUEL TANK
········• ........... ···
FUEL
STRAINER
ENGINE
PRIMER
FUEL
SYSTEM
····SCHEMATIC····
THROTTLE
------=KJ
CARBURETOR ..,, _,,.
--- __ .. ___ ... .................... ija
TO
ENGINE
•
Figure 2-2.
MIXTURE
CONTROL
KNOB

FUEL STRAINER DRAIN KNOB.
Refer to fuel strainer servicing procedures, Section IV.
ELECTRICAL SYSTEM.
Electrical energy is supplied by a 14-volt, direct-current system
powered by an engine-driven generator. A 12-volt battery is located on
the left-hand forward portion of the firewall.
CIRCUIT BREAKERS.
All electrical circuits in the airplane, except the clock circuit, are
protected by circuit breakers. The clock has a separate fuse mounted
adjacent to the battery. The stall warning transmitter and horn circuit
and turn-and-bank indicator circuit are protected by a single automati-
cally resetting circuit breaker mounted behind the instrument panel.
The remaining circuits are protected by "push-to-reset'' breakers on
the instrument panel.
GENERATOR WARNING LIGHT.
The red generator warning light indicates generator output. The
light remains off as long as the generator functions properly. If a mal-
function interrupts generator output, the light will illuminate. It also
will illuminate when the battery or external power is on, before starting
the engine, and whenever engine speed is insufficient to produce gen-
erator output. The light does not show battery drain.
LANDING LIGHTS (OPT).
A three-position, push-pull switch controls the optional landing
lights. To turn one lamp on for taxiing, pull the switch out to the first
stop. To turn both lamps on for landing, pull the switch out to the sec -
ond stop.
ROTATING BEACON (OPT).
The rotating beacon should not be used when flying through clouds or
overcast; the moving beams reflected from water droplets or particles in
the atmosphere, particularly at night, can produce vertigo and loss of
orientation.
2-3

CABIN HEATING AND VENTILATION SYSTEM.
For cabin ventilation, pull the "CABIN AIR" knob out. To raise the
air temperature, pull the "CABIN HT" knob out approximately 1/4" to
1/2" for a small amount of cabin heat. Additional heat is available by
pulling the knob out farther; maximum heat is available with the "CABIN
HT" knob pulled full out and the "CABIN AIR" knob pushed full in. When
no heat is desired in the cabin, the "CABIN HT" knob is pushed full in.
Front cabin heat and ventilating air is supplied by outlet holes spaced
across a cabin manifold just forward of the pilot's and copilot's feet. Rear
cabin heat and air is supplied by two ducts from the manifold, one extend-
ing down each side of the cabin. Windshield defrost air is also supplied by
a duct leading from the cabin manifold.
Separate adjustable ventilators supply additional air; one near each
upper corner of the windshield supplies air for the pilot and copilot, and
two optional ventilators in the rear cabin ceiling supply air to the rear
seat passengers.
STARTING ENGINE.
Ordinarily the engine starts easily with one or two strokes of the
primer in warm temperatures to six strokes in cold weather, with the
throttle open approximately 1/8 inch. In extremely cold temperatures,
it may be necessary to continue priming while cranking.
Weak intermittent explosions followed by puffs of black smoke from
the exhaust stack indicates overpriming or flooding. Excess fuel can be
cleared from the combustion chambers by the following procedure: Set
the mixture control full lean and the throttle full open; then crank the
engine through several revolutions with the starter. Repeat the start-
ing procedure without any additional priming.
If the engine is underprimed (most likely in cold weather with a cold
engine) it will not fire at all, and additional priming will be necessary.
As soon as the cylinders begin to fire, open the throttle slightly to keep
it running.
After starting, if the oil gage does not begin to show pressure within
30 seconds in the summertime and about twice that long in very cold
weather, stop engine and investigate. Lack of oil pressure can cause
2-4

TAXIING DIAGRAM
CODE
WIND DIRECTION t
• •
NOTE
Strong quartering tail winds require caution.
Avoid sudden bursts of the throttle and sharp
braking when the airplane is in this attitude.
Use the steerable nose wheel and rudder to
maintain direction.
Figure 2-3.
2-5

serious engine damage. After starting, avoid the use of carburetor
heat unless icing conditions prevail.
TAXIING.
When taxiing, it is important that speed and use of brakes be held to
a minimum and that all controls be utilized (see taxiing diagram, figure
2-3) to maintain directional control and balance.
Taxiing over loose gravel or cinders should be done at low engine
speed to avoid abrasion and stone damage to the propeller tips.
BEFORE TAKE-OFF.
WARM-UP.
Since the engine is closely cowled for efficient in-flight engine cool-
ing, precautions should be taken to avoid overheating during prolonged
engine operation on the ground.
MAGNETO CHECK.
The magneto check should be made at 1700 RPM as follows: Move
ignition switch first to "R" position, and note RPM. Next move switch
back to "BOTH" to clear the other set of plugs. Then move switch to
the "L" position and note RPM. The difference between the two mag-
netos operated individually should not be more than 75 RPM. If there
is a doubt concerning operation of the ignition system, RPM checks at
higher engine speeds will usually confirm whether a deficiency exists.
An absence of RPM drop may be an indication of faulty grounding of
one side of the ignition system or should be cause for suspicion that the
magneto timing has been "bumped-up" and is set in advance of the set-
ting specified.
TAKE-OFF.
POWER CHECK.
It is important to check full-throttle engine operation early in the
2-6

take-off run. Any signs of rough engine operation or sluggish engine
acceleration is good cause for discontinuing the take-off. H this occurs,
you are justified in making a thorough full-throttle, static runup before
another take-off is attempted. The engine should run smoothly and turn
approximately 2230-2330 RPM with carburetor heat off.
For improved take-off and climb performance, an optional McCauley
lCl 72/EM 7651 climb propeller is available. This propeller has a full-
throttle static RPM range of 2320-2420 RPM.
Full-throttle runups over loose gravel are especially harmful to pro-
peller tips. When take-offs must be made over a gravel surface, it is
very important that the throttle be advanced slowly. This allows the air-
plane to start rolling before high RPM is developed, and the gravel will
be blown back of the propeller rather than pulled into it. When unavoid-
able small dents appear in the propeller blades, they should be immedi-
ately corrected as described in Section IV under propeller care.
Prior to take-off from fields above 5000 feet elevation, the mixture
should be leaned to give maximum RPM in a full-throttle, static runup.
WI NG FLAP SETTINGS.
Normal and obstacle clearance take-offs are performed with wing
flaps up. The use of 10° flaps will shorten the ground run approximately
10%, but this advantage is lost in the climb to a 50-foot obstacle. There-
fore, the use of 10° flaps is reserved for minimum ground runs or for
take-off from soft or rough fields with no obstacles ahead.
H 10° of flaps are used in ground runs, it is preferable to leave them
extended rather than retract them in the climb to the obstacle. The ex-
ception to this rule would be in a high altitude take-off in hot weather
where cli\l'lb would be marginal with flaps 10°.
Flap settings of 30° to 40° are not recommended at any time for take-off.
PERFORMANCE CHARTS.
Consult the take-off chart in Section V for take-off distances under
various gross weight, altitude, and headwind conditions.
CROSSWIND TAKE-OFFS.
Take-offs into strong crosswinds normally are performed with the
2-7

minimum flap setting necessary for the field length, to minimize the
drift angle immediately after take-off. The airplane is accelerated to
a speed slightly higher than normal, then pulled off abruptly to prevent
possible settling back to the runway while drifting. When clear of the
ground, make a coordinated turn into the wind to correct for drift.
CLIMB.
CLIMB DATA.
For detailed data, refer to the Maximum Rate-Of-Climb Data chart
in Section V.
NOTE
H your aircraft is equipped with a 7651 climb pro-
peller, slight improvement in climb performance
may be expected over that shown in Section V.
CLIMB SPEEDS.
Normal climbs are performed at 80 to 90 MPH with flaps up and full
throttle for best engine cooling. The mixture should be full rich unless
the engine is rough due to too rich a mixture. The best rate-of-climb
speeds range from 80 MPH at sea level to 77 MPH at 10,000 feet. H
an obstacle dictates the use of a steep climb angle, the best angle-of-
climb speed should be used with flaps up and full throttle. These speeds
vary from 65 MPH at sea level to 71 MPH at 10,000 feet.
NOTE
Steep climbs at these low speeds should be of short
duration to improve engine cooling.
GO-AROUND CLIMB.
In a balked landing (go-around) climb, the wing flap setting should
be reduced to 20° immediately after full power is applied. Upon reach-
ing a safe airspeed, the flaps should be slowly retracted to the full up
position.
2-8

CRUISE.
Normal cruising is done between 65% and 75% power. The power
settings required to obtain these powers at various altitudes and outside
air temperatures can be determined by using your Cessna Power Com-
puter of the OPERATIONAL DATA, Section V.
NOTE
The Cruise and Range Performance chart on page 5-4
outlines complete cruise figures for the Model 172
equipped with a standard propeller. The table on page
5-5 shows the RPM and speed differentials for a given
%BHP to be considered when figuring cruise perform-
ance if your airplane is equipped with a 7651 climb
propeller.
Cruising can be done most efficiently at high altitudes because of
lower air density and therefore lower airplane drag. This is illustrated
in the following table which shows performance at 75% power at various
altitudes.
OPTIMUM CRUISE PERFORMANCE
ALTITUDE RPM I
TRUE
AIRSPEED I RANGE
Sea Level
2450 123 520
5000 ft. 2560 128 540
7000ft. Full Throttle
130 550
All figures are based on lean mixture, 36 gallons of fuel (no re-
serve), zero wind, standard atmospheric conditions, and 2300 pounds
gross weight.
Carburetor ice, as evidenced by an unexplained drop in RPM, can
be removed by application of full carburetor heat. Upon regaining the
original RPM (with heat off}, use the minimum amount of heat (by
trial and error) to prevent ice from forming. Since heated air causes
a richer mixture, readjust the mixture setting when carburetor heat is
used continuously in cruising flight.
2-9

STALLS.
The stall characteristics are conventional and aural warning is pro-
vided by a stall warning horn which sounds between 5 and 10 MPH above
the stall in all configurations.
Power-off stall speeds at maximum gross weight and aft e.g. posi-
tion are presented on page 5-2 as calibrated airspeeds since indicated
airspeeds are unreliable near the stall.
LANDING.
Normal landings are made power-off with any flap setting. Slips are
prohibited in full flap approaches because of a downward pitch en-
countered under certain combinations of airspeed and sideslip angle.
SHORT FIELD LANDINGS.
For a short field landing, make a power-off approach at approxi-
mately 67 MPH with flaps 40°, and land on the main wheels first. Im-
mediately after touchdown, lower the nose gear to the ground and apply
heavy braking as required. Raising the flaps after landing will provide
more efficient braking.
CROSSWIND LANDINGS.
When landing in a strong crosswind, use the minimum flap setting re-
quired for the field length. Use a wing-low, crab, or a combination method
of drift correction and land in a nearly level attitude. Hold a straight
course with the steerable nosewheel and occasional braking if necessary.
The maximum allowable crosswind velocity is dependent upon pilot
capability rather than airplane limitations. With average pilot technique,
direct crosswinds of 15 MPH can be handled with safety.
COLD WEATHER OPERATION.
STARTING.
Prior to starting on a cold morning, it is advisable to pull the pro-
2-10