Mooney M20M - Artificial Horizon; Compass-Trouble Shooting

MOONEY
AIRCRAFT
CORPORATION
M20M
SERVICE AND
MAINTENANCE
MANUAL
34-22-01
COMPASS
TROUBLE
SHOOTING
TROUBLE
PROBABLE CAUSE
REMEDY
Excessive
card
error.
Compass
not
properly
Compensate
instrument.
compensated.
External
magnetic
interference.
Locate
magnetic
interference
and
eliminate
if
possible.
Excessive card oscillation.
Improper
instrument
mounting. Align
instrument.
Insufficient
liquid.
Replace
instrument.
Sluggish
card.
Weak
card
magnets.
Replace
instrument.
Excessive
pivot
friction
or
Replace
instrument.
broken
jewel.
Instrument
too
heavily
Correct
excess
compensation.
compensated.
Liquid leakage.
Loose
bezel
screws.
Tighten
screws.
Broken
cover
glass.
Replace
instrument.
Defective
sealing gaskets.
Replace
instrument.
Discolored
luminous
markings Age
Replace
instrument.
or
discolored
damping liquid.
Defective
light.
Burnt
out
lamp
or
broken
Check
lamp
or
wiring continuity.
circuit.
34-23-00
ARTIFICIAL
HORIZON
The
vacuum-powered
artificial
horizon
gym
indicates aircraft
attitude
relative
to
straight
and
level
flight.
Maintenance
is
similar
to
that
required
for the directional
gym compass.
34-23-01
GYRO-HORIZON
TROUBLE SHOOTING
TROUBLE
PROBABLE
CAUSE REMEDY
Horizon bar does
not
respond.
Dirty
air
filter
thigh
vacuum
Examine
filter
and clean
or
replace
if
indication),
necessary.
Insufficient
vacuum
resulting
Correct insufficient
vacuum
as
follows:
from
the
following:
1.
Vacuum
regulating
valve
1.
Adjust
valve.
improperly adjusted.
2.
Pump
failure.
2.
Repair
or
replace
pump.
3.
Vacuum
line
kinked,
leaking,
3.
Locate and
repair.
Check for
or
too
long
for
its diameter,
collapsed
inner wall
of flexible hose.
Horizon bar does
not
settle.
Defective
mechanism.
Replace
instrument.
Insufficient
vacuum.
Correct for insufficient
vacuum as
outlined above.
4-99 34-22-01
OLDWILLWAYNE