Mooney M20M - Airspeed Indicator-Trouble Shooting; Altimeter; Rateof-Climb Indicator Trouble Shooting; Vertical Speed Indicator

SERVICE AND
MAINTENANCE
MANUAL
M20M
MOONEY
AIRCRAFT
CORPORATION
34-11-00
AIRSPEED
INDICATOR
Radial
Red
Line
195
KIAS
Registers
airspeed
in knots.
Air
pressure
difference
Yellow
Are
174-195
KIAS
between
impact
air,
pitot
tube,
and
static air
(static
Green
Are 65-174
KIAS
ports
on
each
side
of
the
aircraft
tailcone)
operates
the
airspeed
indicator.
An
electrically
heated
pitot
head
White Are
59-110
KIAS
prevents
ice
obstruction
in
flight.
NOTE
The
airspeed
indicator dial
markings
are
as
follows:
See Section
27-95-00
for
stall
warning
systems.
34-11-01
AIRSPEED
INDICATOR
TROUBLE
SHOOTING
TROUBLE
PROBABLE
CAUSE
REMEDY
Instrument
pointer
does
not
Leak
in
instrument
Check
for leak and
seal
case
or
static
indicate
properly.
lines.
Obstruction
in
pitot
tube.
Clean
out
obstruction.
Instrument
pointer
oscillates.
Leak
in
instrument
case or
in
Check
for
leak and
seal
lines.
pitot
lines.
34-12-00
VERTICAL
SPEED
INDICATOR
This instrument
has
a
single
needle
and
two
adjoining
Converts barometric
pressure
changes
within
the static
scales
that read
from
0
to
2000
feet
per
minute,
top
side
for
ascent rate
and
bottom
side
for
descent
rate.
port
lines
to
aircraft
ascent
or
descent
rate;
readings
The
recessed,
slotted
screw
at
the
lower
left
of
the
are
in
feet
per
minute.
instrument
case
is
used
to
"zero" the
indicator
when
the
aircraft
is
on
the
ground.
34-12-01
RATE-OF-CLIMB
INDICATOR
TROUBLE
SHOOTING.
(VERTICAL
SPEED
INDICATOR)
TROUBLE
PROBABLE
CAUSE
REMEDY
Pointer does
not set
on zero.
Aging
of
diaphragm.
Turn
setting
screw
to
reset
pointer
at
zero.
Tap
instrument
while
resetting.
Pointer fails
to
respond.
Obstruction
in
static
line.
Disconnect
static line
from instruments.
(Includes
water)
Apply
low
pressure
air
(10-25
PSI
max.)
to
instrument
end
of
static
line.
Check
both
static
ports
for air
flow.
Depress
static
drain
valve
and
check
for
water.
Keep
depressed
until
air
is
free of
moisture.
Reconnect
static
line
to
instruments
and leak
check.
Pointer
oscillates.
Leaks
in
static
line.
Disconnect
all instruments
connected
to
the
static
line.
Check
individual
instruments
and
test
installation
for
leaks.
Defective
mechanism.
Replace
instrument.
34-1
3-00
-ALTIMETER
The
altimeter
operates
by
absolute
pressure
and
converts
barometric
pressure
to
altitude;
reading
is
in
feet
above
mean sea
level.
The
altimeter
has
a
fixed
dial with
three
pointers
to
indicate
hundreds,
thousands,
and
tens
of
thousands of feet. Barometric
pressure
is
sensed
through
the
static
vents.
A
knob
adjusts
a
movable
dial
behind
a
small window
in
the face of the
main
dial
to
indicate
local
barometric
pressure.
This
corrects
the
altimeter
reading
for
prevailing
conditions.
34-11-00
4-99
OLDWILLWAYNE