Piper PA-28-236 DAKOTA, Pilot Operating Handbook

Page: 314 / 367

SECTION 9 PIPER AIRCRAFT CORPORATION
SUPPLEMENT 9 PA-28-236, DAKOTA
REPORT: VB-910 ISSUED: JULY 23, 1982
9-64
Figure 7-3 (cont)
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 auto trim 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 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 wet.
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 approximately 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 signals plus glide slope coupling in the case of an ILS. The
tracking gain of the APR mode is greater than the gain in the NAV
mode. The APR annunciator will flash until the automatic capture
sequence is initiated.