Cessna 172N - Page 65

CESSNA
MODEL 172N
SECTION
5
PERFORMANCE
INTRODUCTION
Performance data
charts
on
the
following
pages
are
presented
so
that
you
may know
what
to expect
from the
airplane
under various
conditions,
and also, to facilitate the
planning
of flights
in
detail
and
with
reasonable
accuracy. The
data
in the charts has been computed
from actual flight tests with the airplane and engine
in
good
condition
and using average
piloting
techniques.
It should be noted that
the
performance
information
presented
in
the range and
endurance
profile
charts
allows for 45
minutes
reserve
fuel
based on 45Vo
power.
Fuel flow
data for
cruise
is based
on
the
recommended
lean
mixture
setting. Some
indeterminate variables
such
as
mixture
leaning
technique,
fuel metering
characteristics,
en-
gine
and
propeller
condition, and air
turbulence
may account for varia-
tions of. LOVo or more in range
and endurance. Therefore, it is impor-
tant
to
utilize
aII available
information to estimate
the fuel required
for
the
particular
flight.
USE OF
PERFORMANCE
CHARTS
Performance
data
is
presented
in tabular or
graphical
form
to
illus-
trate
the
effect of
different
variables.
Sufficiently
detailed
information
is
provided
in the
tables so that conservative
values
can
be selected
and used to determine the
particular
performance
figure
with
reasona-
ble
accuracy.
SAMPLE
PROBLEM
The following
sample
flight
problem
utilizes information from the
various charts to
determine
the
predicted
performance
data for
a
typi-
cal flight. The following information
is known:
AIRPLANE
CONFIGURATION
Takeoff weight
Usable fuel
TAKEOFF
CONDITIONS
F ield
pressure
altitude
Temperature
Wind
component along
runway
Fietd length
2250
Pounds
40
Gallons
1500 Feet
28oC
(16oC
above
standard)
12 Knot
Headwind
3500 Feet
5-3