Piper PA-28-161 Pilot Operating Handbook page 239

SECTION 9
SUPPLEMENT 7
Figure 7-3 (cont)
PIPER AIRCRAFT CORPORATION
PA-28·161, WARRIOR II
5. TRIM WARNING LIGHT (TRIM) - Illuminates continuously
whenever trim power is not on or the system has not been preflight
tested. Flashes and is accompanied by an audible warning whenever
a manual trim fault is detected. The TRIM warning light will
illuminate steady and be accompanied by a steady audible tone
whenever an autotrim failure occurs. The autotrim system is moni-
tored 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 trim power switch 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
preflight test is 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.
10. APPROACH (APR) MODE SELECTOR BUTTON - When
pushed, will select the Approach mode. This mode provides all
angle intercept (with HSI) or a fixed angle intercept of 45° (with
DG), automatic beam capture and tracking of VOR, RNAV or
LOC
sig~als
plus glide slope coupling in the case of an lLS. The
!'·c:
>-~ --~
;a in
c~
the APR mode is greater than the gain in the NA V
me>:.., . .
;,~APR
annunciator will flash until the automatic capture
seq ut:nce is initiated.
REPORT: VB-1180 ISSUED: AUGUST 1
~.
1982
9-62, 16 of 26