Textron 172R180HP, Pilot Operating Handbook

Page: 212 / 396

SECTION 7 CESSNA
MODEL 172R (180 HP) AIRPLANE & SYSTEMS DESCRIPTION
&WARNING
UNUSABLE FUEL LEVELS FOR THIS AIRPLANE
WERE DETERMINED IN ACCORDANCE WITH
FEDERAL AVIATION REGULATIONS. FAILURE
TO OPERATE THE AIRPLANE IN COMPLIANCE
WITH FUEL LIMITATIONS SPECIFIED IN
SECTION 2 MAY FURTHER REDUCE THE
AMOUNT OF FUEL AVAILABLE IN FLIGHT.
FUEL FUEL LEVEL
TOTAL TOTAL
TOTAL USABLE
TANKS (QUANTITY
FUEL
UNUSABLE ALL FLIGHT
EACH TANK) CONDITIONS
Two Full (28.0) 56.0 3.0 53.0
Figure 7-5. Fuel Quantity Data in U.S. Gallons
FUEL DISTRIBUTION
I
Fuel flows by gravity from the two wing tanks to a three-position
selector valve, labeled BOTH, RIGHT and LEFT and on to the
'reservoir tank. From the reservoir tank, fuel flows through the
auxiliary fuel pump, past the fuel shutoff valve, through the fuel
strainer to an engine driven fuel pump.
From the engine driven fuel pump, fuel is delivered to the fuel/air
control unit, where it is metered and directed to a fuel distribution
valve (manifold) which distributes it to each cylinder. Fuel flow into
each cylinder is continuous, and flow rate is determined by the
amount of air passing through the fuel/air control unit.
7-24
Oct 4/01