Piper Pawnee Brave - 2 E13; 10-7. Pitot and Static System; Maintenance

PAWNEE
BRAVE
SERVICE
MANUAL
NOTE
For
easy
removal
of
instruments
in
top
panel,
remove
trim
cover,
then
remove
the
two
mounting
screws
on
each
side
of
the
panel;
pull
the
panel
back
as
far
as
possible
and
refer
to
procedures
a
through
c
of
this
paragraph.
d.
Several
instruments
are
held
in
place
by
a
metal
bracket.
To
remove
this
type
instrument,
disconnect
the
wiring
or
plumbing;
remove
nuts
securing
bracket
to
instrument;
then
remove
instrument
from
the
front
side
of
the
panel.
CAUTION
Cap
open
lines
and
cover
pressure
connections
on
the
instruments
to
prevent
thread
damage
and
entrance
of
foreign
material.
Wire
terminals
should
be
insulated
or
tied
up
so
they
will
not
ground
accidentally
or
short
on
another
terminal.
10-6.
INSTALLATION
OF
INSTRUMENTS.
Installation
procedures
are
basically
the
reverse
of
the
removal
procedures.
Several
items
that
should
be
noted
are:
a.
Make
sure
wire
terminals
are
clean
and
plugs
or
caps
are
removed
from
fittings.
b.
If
thread
lubricant
or
sealer
is
used,
be
sure
to
use
it
sparingly
and
apply
on
male
threads
only.
c.
Tighten
fittings,
wire
terminal
connections,
and
instrument
mounting
hardware
firmly,
but
do
not
overtighten,
especially
on
instruments
with
plastic
cases.
10-7.
PITOT
AND
STATIC
SYSTEM.
10-8.
DESCRIPTION.
The
pitot
system
transfers
ram
air
pressure,
taken
in
by
the
pitot
mast
on
the
underside
of
the
left
wing,
through
tubing
to
the
airspeed
indicator.
The
static
system
vents
the
altimeter
and
airspeed
indicator,
through
tubing
to
two
static
vents,
one
on
each
side
of
the
turtledeck
just
aft
of
the
cockpit.
A
pitot
system
drain
valve
is
located
on
the
underside
of
the
left
wing
just
aft
of
the
main
spar
and
in
the
wing
root
fairing.
The
sump
for
the
static
system
is
located
to
the
left
of
the
pilot's
seat
on
the
side
of
the
console
below
the
fuel
shutoff
valve.
An
alternate
static
source
valve
is
located
under
the
crash
roll
through
the
slot
between
the
two
lower
instrument
panels.
A
placard
on
the
crash
roll
clearly
marks
the
location
and
directions
for
use.
10-9.
MAINTENANCE.
Frequent
maintenance
of
the
pitot
and
static
systems
is
necessary
to
insure
proper
operation
of
altimeter
and
airspeed
indicator.
Obstructions,
moisture,
or
leaks
in
the
pitot
system
will
create
false
airspeed
readings,while
static
system
malfunctions
will
affect
the
readings
of
both
instruments.
Pitot
and
static
system
drains
should
be
opened
after
washing
the
aircraft
or
any
time
the
system
is
exposed
to
moisture.
Check
pitot
tube
daily
for
insects,
grass,
or
any
other
obstructions
that
may
prevent
air
from
entering.
Check
static
vents
for
wax,
dirt,
or
any
obstructions
that
may
block
the
ports.
Check
fittings
and
clamps
for
security
and
rubber
hose
for
general
condition.
Cleanliness
and
security
are
the
important
factors
for
system
maintenance.
Reference
to
Federal
Aviation
Agency
Advisory
Circular
AC
No.
AC
43-203A
provides
general
information
concerning
the
test
equipment
used,
and
precautions
to
be
taken
when
performing
such
tests.
INSTRUMENTS
2E13
Revised:
9/30/75