Fuel System - Cessna 152 Training Manual

Fuel System

Fuel is supplied to the engine from two integral wing tanks. From these, fuel
flows by gravity feed through the fuel shut-off valve and the fuel strainer,
manual primer to the carburettor.
The fuel capacity is:
Standard Tanks - Total usable fuel 24.5 US gallons (91 litres), total
capacity 26 US gallons (98 litres);
Long Range Tanks - Total usable fuel 37.5 US gallons (141 litres),
total capacity 39 US gallon (147 litres).
The long range tanks, although specified in the pilot's operating handbook, are
a relatively uncommon installation, and not specified on the type certification
data. Some Cessna 152's with standard tanks may have post manufacturer
auxiliary tanks installed to increase fuel capacity.
The amount of fuel we can put into fuel tanks is limited by the volume of the
tanks, and therefore usable fuel is always provided in volume, such as gallons
and litres.
However, the carburettor and engine are only sensitive to the mass of fuel, and
not to the volume. The engine will consume a certain mass (lbs or kgs) of fuel
per hour.
Fuel has a wide variation in specific gravity (weight of fuel per volume) mostly
depending on temperature and type of fuel. Therefore, variations in specific
gravity of fuel can have a significant effect on the mass of fuel in the tanks and
therefore the range and endurance.
For practical purposes the specific gravity of Avgas is taken as 0.72 kgs/lt.
The fuel valve is located on the floor of the cockpit between the pilot and co-
pilot seats. The valve has two positions: ON and OFF.
With the valve in the ON position, fuel flows through a strainer to the
carburettor. The fuel strainer is mounted at the firewall in the lower engine
compartment. The strainer is equipped with a quick-drain valve which provides
a means of draining trapped water and sediment from the fuel system. The
Fuel Fuel
Strainer strainer
by D. Bruckert & O. Roud © 2004
CESSNA 152 TRAINING MANUAL
Illustration 6a Fuel Strainer
Quick-drain Control Quick-drain control
Page 47