Cessna Skyhawk 172N Pilot Operating Handbook page 129

CESSNA
SECTION 7
MODEL 172N
AIRPLANE
&
SYSTEMS DESCRIPTIONS
all of the fuel in one tank, and. after switching to the
opposite tank, expect an equal duration from the remain­
ing fuel. The airspace in both fuel tanks is interconnected
by a vent line and, therefore, some sloshing of fuel between
tanks can be expected when the tanks are nearly full and
the wings are not level.
The fuel system is equipped with drain valves to provide a means for
the examination of fuel in the system for contamination and grade. The
system should be examined before the first flight of every day and after
each refueling. by using the sampler cup provided to drain fuel from the
wing tank sumps, and by utilizing the fuel strainer drain under an access
panel on the right side of the engine cowling. The fuel tanks should be filled
after each flight to prevent condensation.
BRAKE SYSTEM
The airplane has a single-disc, hydraulically-actuated brake on each
main landing gearwheel. Each brake is connected, by a hydraulic line, to a
master cylinder attached to each of the pilot's rudder pedals. The brakes
are operated by applying pressure to the top of either the left (pilot's) or
right (copilot's) set of rudder pedals, which are interconnected. When the
airplane is parked. both main wheel brakes may be set by utilizing the
parking brake which is operated by a handle under the left side of the
instrument panel. To apply the parking brake, set the brakes with the
rudder pedals, pull the handle aft, and rotate it 90° down.
For maximum brake life, keep the brake system properly maintained,
and minimize brake usage during taxi operations and landings.
Some of the symptoms of impending brake failure are: gradual
decrease in braking action after brake application, noisy or dragging
brakes, soft or spongy pedals. and excessive travel and weak braking
action. If any of these symptoms appear, the brake system is in need of
-
immediate attention,
If,
during taxi or landing roll, braking action de­
creases, let up on the pedals and then re-apply the brakes with heavy
pressure. If the brakes become spongy or pedal travel increases, pumping
the pedals should build braking pressure. If one brake becomes weak or
fails, use the other brake sparingly while using opposite rudder, as
required, to offset the good brake.
-'­
ELECTRICAL SYSTEM
The airplane is equipped with a 28-volt. direct-current electrical
system (see figure 7-7). The system is powered by an engine-driven, 60­
1 July 1978 7-23