Cessna 152 - Page 123

CESSNA
MODEL
152
SECTION7
AIRPLANE
&
SYSTEMS
DESCRIPTIONS
tanks
(
one
in
each
wing),
a
fuel
shutoff
valve,
fuel
strainer,
manual
primer,
and
carburetor.
Refer
to
figure
7-5
for
fuel
quantity
data
for
both
systems.
Fuel
flows
by
gravity
from
the
two
wing
tanks
to
a
fuel
shutoff
valve.
With
the
valve
in
the
ON
position,
fuel
flows
through
a
strainer
to
the
carburetor.
From
the
carburetor,
mixed
fuel
and
air
flows
to
the
cylinders
through
intake
manifold
tubes.
The
manual
primer
draws
its
fuel
from
the
fuel
strainer
arid
injects
it
into
the
cylinder
intake
ports.
Fuel
system
venting
is
essential
to
system
operation.
Blockage
of
the
venting
system
will
result
in
a
decreasing
fuel
flow
and
eventual
engine
stoppage.
Venting
is
accomplished
by
an
interconnecting
line
from
the
right
fuel
tank
to
the
left
tank.
The
left
tank
is
vented
overboard
through
a
vent
line
which
is
equipped
with
a
check
valve,
and
protrudes
from
the
bottom
surface
of
the
left
wing
near
the
wing
strut
attach
point.
The
right
fuel
tank
filler
cap
is
also
vented.
Fuel
quantity
is
measured
by
two
float-type
fuel
quantity
transmitters
(
one
in
each
tank)
and
indicated
by
two
electrically-operated
fuel
quantity
indicators
on
the
lower
left
portion
of
the
instrument
panel.
An
empty
tank
is
indicated
by
a
red
line
and
the
letter
E.
When
an
indicator
shows
an
empty
tank,
approximately
.75
gallon
remains
in
either
a
standard
or
long
range
tank
as
unusable
fuel.
The
indicators
cannot
be
relied
upon
for
accurate
readings
during
skids,
slips,
or
unusual
attitudes.
The
amount
of
unusable
fuel
is
relatively
small
due
to
the
dual
outlets
at
each
tank.
The
maximum
unusable
fuel
quantity,
as
determined
from
the
most
critical
flight
condition,
is
about
1~5
gallons
total.
This
quantity
was
not
exceeded
by
any
other
reasonable
flight
condition,
including
pro-
longed
30
second
full-rudder
sideslips
in
the
landing
configuration.
Takeoffs
have
not
been
demonstrated
with
less
than
2
gallons
total
fuel
(1
gallon
per
tank).
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.
When
the
airplane
is
equipped
with
long
range
tanks,
it
may
be
serviced
to
a
reduced
fuel
capacity
to
permit
heavier
cabin
loadings.
This
is
accomplished
by
filling
each
tank
to
the
bottom
of
the
indicator
on
the
fuel
filler
neck.
When
filled
to
this
level,
the
tank
contains
13
gallons
(12.25
usable
in
all
flight
conditions).
1
July
1978
7-21