Textron Aviation Cessna 172S NAV III Skyhawk SP, Information Manual

Page: 140 / 490

SECTION 4 CESSNA
NORMAL PROCEDURES MODEL 172S NAV III
KAP 140 AUTOPILOT
U.S.
CRUISE
Normal cruise is performed between 45% and 75% power. The engine
RPM and corresponding fuel consumption for various altitudes can be
determined by using the data in Section 5.
NOTE
Cruise flight should use 75% power as much as possible
until the engine has operated for a total of 50 hours or oil
consumption has stabilized. Operation at this higher power
will ensure proper seating of the piston rings and is
applicable to new engines, and engines in service following
cylinder replacement or top overhaul of one or more
cylinders.
The Cruise Performance charts in Section 5 provide the pilot with flight
planning information for the Model 172S in still air with speed fairings
installed. Power, altitude, and winds determine the time and fuel
needed to complete any flight.
The Cruise Performance Table, Figure 4-3, shows the true airspeed
and nautical miles per gallon during cruise for various altitudes and
percent powers, and is based on standard conditions and zero wind.
This table should be used as a guide, along with the available winds
aloft information, to determine the most favorable altitude and power
setting for a given trip. The selection of cruise altitude on the basis of
the most favorable wind conditions and the use of low power settings
are significant factors that should be considered on every trip to reduce
fuel consumption.
In addition to power settings, proper leaning techniques also contribute
to greater range and are figured into cruise performance tables. To
achieve the recommended lean mixture fuel consumption figures
shown in Section 5, the mixture should be leaned using the Exhaust
Gas Temperature (EGT) indicator as noted.
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172SPHAUS-05
4-34
For
Training
Purposes
Only