Magnetic Compass; Adjustment Of Compass; Troubleshooting (Magnetic Compass) - Piper Dakota Maintenance Manual

MAGNETIC COMPASS

The magnetic compass is a self-contained instrument. This instrument has a light connected to the
instrument lighting circuit. The compass correction card is located in the card holder mounted on the
instrument. The compass should be swung whenever instruments or radios are changed or once a year
whichever comes first.

ADJUSTMENT OF COMPASS

Before attempting to compensate compass, place aircraft in simulated flight conditions: doors closed, flaps
retracted, engine running, throttle set at cruise, and aircraft in level flight attitude. Set master switch, alternator
switch and all radio switches ON. Set all other cockpit controlled electrical switches OFF.
l. Set adjustment screws of compensator at zero. Zero position of adjusting screws is when dot of screw
is lined up with dot of frame.
2. Head aircraft on magnetic north heading. Adjust N-S adjustment screw until compass reads north.
3. Head aircraft on magnetic east heading and adjust E-W adjusting screw until compass reads east.
4. Head aircraft on magnetic south heading and note resulting south error. Adjust N-S adjusting screw
until one-half of this error is removed.
S. Head aircraft on magnetic west and adjust E-W adjustment screw until one-half of this error is
removed.
6.- Head aircraft in successive magnetic 30° headings and record compass readings on deviation card.
CHART 3404. TROUBLESHOOTING (MAGNETIC COMPASS)
Trouble
Exeessive card error.
Excessive card oscillation.
Card sluggish.
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
—NOTE—
Deviations must not exceed +10º on any heading.
Cause
Compass not properly
compensated.
External magnetic inter-
ference.
Insufficient liquid.
Weak card magnet.
Excessive pivot friction or
broken jewel.
2D19
Remedy
Compensate instrument.
Locate magnetic inter-
ference and eliminate if
possible.
Replace instrument.
Replace instrument.
Replace instrument.
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Reissued: August 1, 1986