Mooney M20K - Directional Gyro Compass

MOONEY AIRCRAFT
CORPORATION M20K
SERVICE
AND
MAINTENANCE MANUAL
3413-01
-ALTIMETER TROUBLE
SHOOT1NG
TROUBLE
PROBABLE CAUSE
REMEDY
Excess
scale
error.
Improper
calibration
Replace
instrument.
adjustment.
Excessive
pointer
oscillation. Defective mechanism.
Replace
instrument.
High reading.
Static
pressure
system
leak.
ETm’nate
leak
in static
pressure
system
Setting
knob is hard
to turn.
Wrong
lubn’cant
or
lack
Replace
instrument.
of
lubrication.
Inner
reference marker
fails
to
Marker
out
of
engagement.
Replacement
instrument.
mxR
wf~en
setting
knob
is
rotated
Setting
knob
set-screw
is Excessive vibration.
Tighten
instrument
screw
if loose.
loose
or
missing.
Replace
instrument
if
screw
is
missing.
Cracked
or
loose
cover
Excessive
vibration.
Replace
instrument.
glass.
Dull
or
discolored luminous
Age.
Replace
instrument.
markings.
Barometric scale
and Shift in mechanism.
Reset
pointers.
reference
markers
are
out
of
synchronization
with
pointers.
Batometn’e
scale and
Slippage
of
mating
parts.
Replace
instrument.
reference
markers
are
out
of
synchronization.
34-2090 DIRECTIONAL GYRO COMPASS
directional
heading.
Vacuum
pressure
for
satisfactory
This
vacuum-ope~ated
instrument
indicates
the
operation
is
4.25 ~-.2
to
5.5 +0.0/-.2. The
vacuum
heading
reference.
systemfilters
should
be
changed
each 500 hours
or
at
one
year
intervals,
whichever
occurs
first.
(See
The
directional
gym
rotor
is air driven and
rotates
with
Trouble
Shooting
Chart,
for maintenance
instructions.)
its
spin
a>ds
horizontal.
The knob is
used
to
reset
basic
34-2091 DIRECTIONAL
GYRO
TROUBLE SHOOT1NG
TROUBLE PROBABLE CAUSE
REMEDY
Excessive
drift
in either
Dirty
air filter
thigh
vacuum
Inspect
filter.
Replace
if
necessary.
direction,
indication).
Excessive vibration.
Test
with
vibrometer. If
vibration
amplitude
is
more
than .004
inch,
examine
shock
mountings
to
see
if
connections
are
pulling
on
instrument.
Insufficient
vacuum.
If
vacuum
Correct
for insufficient
vacuum
as
indication is
below
4.25 IN.
Hg.,
follows:
check
as
follows:
Vacuum
regulating
valve
1.
Adjust
vacuum
regulating
valve.
improperly adjusted.
34-13-01
OLDWILLWAYNE