Cessna Skyhawk Owner's Manual page 23

AIRSPEED
CORRECTION
TABLE
OPTIMUM CRUISE
PERFORMANCE
IAS 40
50 60
70 80
90
100
110 120
130 140
ALTITUDE RPM TRUE
AIRSPEED
RANGE
FLAPS
UP
CAS 55
58 65
72
-82
91 101 110
120
129 139
Sea Level 2490
123
575
5000 ft.
2600
128 600
FLAPS
DOWN
CAS
48
54
63
72 82
93 105
• •
• •
9000 ft.
Full Throttle
132 620
Figure
5-1. To achieve
the
lean mixture fuel consumption
figures
shown in Section
V,
the
mixture should be leaned as follows: pull mixture control out
until
engine RPM peaks and begins
to
fall off,
then
enrichen slightly back
to
peak RPM.
Carburetor
ice, as evidenced by an
unexplained
drop in RPM, can be
removed by application of full carburetor heat. Upon regaining
the origi-
nal RPM (with heat off),
use
the
minimum amount of heat
(by
trial
and
error)
to
prevent ice from forming. Since
the
heated
air
causes a richer
mixture, readjust
the
mixture setting when carburetor heat is
to
be used
continuously in cruise flight.
The use of full carburetor heat is recommended during flight
in heavy
rain
to
avoid
the
possibility of engine stoppage due
to
excessive water
in-
gestion
or carburetor ice. The mixture
setting
should be readjusted for
smoothest operation.
POWER
OFF
STALLING
SPEEDS
MPH
-
CAS
In extremely
heavy rain,
the
use of partial carburetor
heat
(control
approximately
2/3
out),
and part
throttle
(closed
at
least one inch),
may
'
be necessary
to
retain adequate power. Power
changes
should be made
ANGLE OF
BANK
cautiously followed by prompt adjustment of
the
mixture for
smoothest
CONDITION
0° 20°
40°
60•
operation.
FLAPS
UP
57
59
65
81
STALLS.
2300
LBS.
GROSS FLAPS
10°
52
54
59 74
The
stall
characteristics are
conventional
and aural warning
is pro-
WEIGHT
vided by
a stall warning horn which sounds
between 5
and
10 MPH
above
the
stall
in all configurations.
FLAPS
40°
49
51 56
69
Power-off
stall speeds at
maximum
gross
weight
and aft
c.g.
posi-
tion are
presented on page
5-2 as calibrated
airspeeds
since indicated
Figure
5-2.
airspeeds are unreliable near
the
stall.
5-2 2-11