Piper PA-28-161, Maintenance Manual

Page: 587 / 1104

PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL
PAGE 19
Nov 30/06 3H19
34-20-00
(3) Adjustment
Before attempting to compensate compass, place the aircraft in simulated flight conditions.
Check to see that the doors are closed, flaps in retracted position, engine running, throttle set
at 1000 rpm or low idle, 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. Use a brass or other non-magnetic screwdriver to
make adjustments to compensator screws.
(a) Place airplane on compass rose designed and intended for adjusting magnetic
compasses.
(b) 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.
(c) Align airplane with magnetic North heading on the compass rose. Adjust N-S adjustment
screw until compass reads exactly North.
(d) Align airplane with magnetic East heading on the compass rose. Adjust E-W adjusting
screw until compass reads exactly East.
(e) Align airplane with magnetic South heading and note error. Adjust N-S adjusting screw
until one-half of the error has been removed.
(f) Align airplane with magnetic West heading and note error. Adjust E-W adjusting screw
until one-half of the error has been removed.
(g) Align airplane with magnetic north. Note heading being indicated on magnetic compass
(may not be North) and enter on compass deviation (correction) card.
(h) Align airplane with successive magnetic 30° headings, i. e., 030°, 060°, 090°, 120°, etc.
Enter actual compass reading on each heading on compass deviation (correction) card.
(i) If deviations (difference between actual magnetic heading and what compass indicates on
that particular heading) exceeds ± 10° on any heading:
1 Check to be sure no magnetic metals are near compass (tools, flashlights, pocket
knives, wristwatches, etc.)
2 Check to be sure screwdriver being used to make adjustments is either fiber or non-
magnetic metal, such as brass.
(j) When satisfied that errors in excess of 10° is fault of the instrument, replace instrument.
(k) After installing new instrument, repeat steps (1) through (8).
D. Magnetometer/OAT Sensor Assembly (See Figure 2, Sheet 3.)
The Magnetometer / OAT Sensor Assembly (Mag/OAT) is mounted on a wing access cover plate in
the underside of the outboard left wing and supplies magnetic heading information to the Primary
Flight Display (PFD). The cover plate - Mag/OAT sensor assembly is removed and installed as a unit.
(1) Removal
(a) Remove eight (8) screws and support cover plate with your hand.
(b) Drop cover plate down sufficient to reach inside and disconnect the wiring harness.
(c) Remove cover plate - Mag/OAT sensor assembly.
(2) Installation
(a) Connect the Mag/OAT sensor assembly wiring harness.
(b) Position the cover plate - Mag/OAT sensor assembly in the access hole with the arrow on
the magnetometer pointing forward.
(c) Secure with screws (8).