Arrow PA-28R-201 Pilot's Operating Handbook And Faa Approved Airplane Flight Manual page 278

SECTION 9
SUPPLEMENT 7
Figure 7-3 (cont)
PIPER AIRCRAFT CORPORATION
PA-28R-201, ARROW
or absence of glideslope pointers in KI 52SA). The autopilot reverts
to pitch attitude hold operation. If a valid glideslope signal returns
within six seconds, the autopilot will automatically recouple in the
GS mode. If the valid signal does not return within six seconds, the
autopilot will remain in pitch attitude hold mode until such time that
a valid glideslope returns and the aircraft passes thru the glide-
slope. At that point GS couple will re-occur.
5. TRIM WARNING LIGHT (TRIM) - IIluminates continuously
whenever trim power is not on or the system has not been preflight
tested. The TRIM warning light flashes and is accompanied by an·
audible warning whenever a manual trim fault is detected. The
Manual Trim System is monitored for the trim servo running
without a command. The TRIM warning light will illuminate
and be accompanied by an audible tone whenever an autotrim
failure occurs. The autotrim system is monitored for the
following failures: trim servo running without a command; trim
servo not running when commanded to run; trim servo running in
the wrong direction. The pitch trim circuit breaker may be cycled off
to silence the continuous tone but the trim fail light will remain
on. The manual electric trim may be used but the autopilot should
not be engaged.
6. AUTOPILOT ANNUNCIATOR (AP) - Illuminates continuously
whenever the autopilot is engaged. Flashes approximately 12 times
whenever the autopilot is disengaged (an aural alert will also sound
for 2 seconds).
7. AUTOPILOT ENGAGE (AP ENG) BUTTON - When pushed,
engages autopilot if all logic conditions are met.
8. PREFLIGHT TEST (TEST) BUTTON - When momentarily
pushed, initiates preflight test sequence which automatically turns
on all annunciator lights, tests the roll and pitch rate monitors, tests
the autotrim fault monitor, checks the manual trim drive voltage
and tests all autopilot valid and dump logic. If the preflight is
successfully passed, the AP annunciator light will flash for approxi-
mately 6 seconds (an aural tone will also sound simultaneously with
the annunciator flashes). The autopilot cannot be engaged until the
autopilot preflight tests are successfully passed.
9. BACK COURSE APPROACH (BC) MODE SELECTOR
BUTTON - When pushed, will select the Back Course Approach
mode. This mode functions identically to the approach mode except
that response to LOC signals is reversed. Glide slope coupling is
inhibited in the Back Course Approach mode.
REPORT: VB-1365
ISSUED: SEPTEMBER 15,1988
9-70,
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