Piper Cherokee Six - Airspeed Indicator

PIPER
CHEROKEE
SIX
SERVICE
MANUAL
TABLE
IX-V.
ALTIMETER
(cont)
Cause
Trouble
Remedy
Altimeter
sticks
at
altitude
or
does
not
change
with
change
of
altitude.
Altimeter
changes
reading
as
aircraft
is
banked.
Altimeter
requires
resetting
frequently.
Water
or
restriction
in
static
line.
Water
in
static
line.
Temperature
compensator
inoperative.
Remove
static
lines
from
all
instruments,
blow
line
clear
from
cockpit
to
pitot
head.
Remove
static
lines
from
all
instruments.
and
blow
line
clear
from
cockpit
to
pitot
head.
Change
instrument.
NOTE
When.
any
connections
in
the
static
system
are
opened
for
check,
system
must
be
rechecked
per
F.A.R.
23.1325.
9-33.
REMOVAL
AND
REPLACEMENT.
Refer
to
Paragraph
9-74
of
this
section.
9-34.
AIRSPEED
INDICATOR.
9-35.
GENERAL.
The
airspeed
indicator
provides
a
means
of
indicating
the
speed
of
the
airplane
passing
through
the
air.
The
airspeed
indication
is
the
differential
pressure
reading
between
pitot
air
to
pressure
and
static
air
pressure.
This
instrument
has
the
diaphragm
vented
to
the
pitot
air
source
and
the
case
is
vented
to
the
static
air
system.
As
the
airplane
increases
speed,
the
pitot
air
pressure
increases,
causing
the
diaphragm
to
expand.
A
mechanical
linkage
picks
up
this
motion
and
moves
the
instrument
pointer
to
the
indicated
speed.
The
instrument
dial
is
calibrated
in
knots
and
miles
per
hour,
and
also
has
the
necessary
operating
range
markings
for
safe
operation
of
the
airplane.
INSTRUMENTS
Revised:
6/18/76
2K19