Magnetic Compass; Adjustment Of Compass; General; 10-41A - Piper ARROW III Service Manual

TABLE X-VI. AIRSPEED TUBES AND INDICATOR (cont)
Trouble
Instrument reads high.
Instrument reads low.
Airspeed changes as
aircraft is banked.
When any connections in static system are opened for checking, system
must be checked per Part 23.1325.
10-39. REMOVAL AND REPLACEMENT. (Refer to Paragraph 10-76 of this section.)

10-40. MAGNETIC COMPASS.

10-41. GENERAL. The magnetic compass is a self-contained instrument. This instrument has an individual
light which is 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
and at least once a year.
10-41a. ADJUSTMENT OF COMPASS. Before attempting to compensate compass, every effort should be
made to place the aircraft in simulated flight conditions; check to see that the doors are closed, flaps in
retracted position, engine running, throttle set at cruise position and aircraft in level flight attitude. Aircraft
master switch, alternator switch and all radio switches should be in the ON position. All other cockpit
controlled electrical switches should be in the OFF position.
a. Set adjustment screws of compensator on zero. Zero position of adjusting screws is when the dot of the
screw is lined up with the dot of the frame.
b. Head aircraft on a magnetic North heading. Adjust N-S adjustment screw until compass reads exactly
North.
c. Head aircraft on a magnetic East heading and do the same as step b, adjusting E-W adjusting screw.
d. Head aircraft on a magnetic South heading and note resulting South error. Adjust N-S adjusting screw
until one-half of this error has been removed.
Revised: 2/13/89
CHEROKEE ARROW III SERVICE MANUAL
Pointer not on zero.
Leaking static system.
Pointer not on zero.
Leaking static system.
Pitot head not aligned
correctly.
Water in pitot line.
Cause
NOTE
2G4
Remedy
Replace instrument.
Find leak and correct.
Replace instrument.
Find leak and correct.
Realign pitot head.
Remove lines from static
instruments and blow
out lines from cockpit
to pitot head.
INSTRUMENTS