TM 1-1510-225-10 8-14 b.  DC loads (Parallel within 10%): (1)  75% maximum – LOW IDLE (2)  85% maximum – HIGH IDLE. (3)  85% maximum – Ground Operations. 12.  AVIONICS MASTER PWR – ON. 13.  STANDBY HORIZON – ON, and uncaged. 14.  EFIS POWER switches – ON. 15.  AP/TRIM POWER switch – ON. 16.  Autopilot self-test – Monitor. a.  Allow   3-4   minutes   for   gyros   to   erect, HDG and ATTITUDE flags clear. b.  A/P    FAIL    and    A/F    TRIM    FAIL    – Annunciators illuminate upon initial application   of   AP/TRIM   POWER   and then extinguish (followed by an audio test tone)  after  successful  completion  of  the self-test.    Allow  60  seconds  after  gyros are valid. c.   Repeat self-test on copilot's side. CAUTION Taxi with caution. The autopilot temporarily engages the servos during the automatic    self-test.        Be    prepared    to overpower the autopilot as required. NOTE Illumination   of   the   AP   FAIL   annunciator other than during initial power-up indicates a   failure.      This   failure   annunciation   will result  in  power  being  removed  from  the roll, pitch, yaw, pitch trim, and rudder trim servos.      The   flight   director   may   remain functional  depending  upon  the  nature  of the    failure.        The    continuous    self-test feature   may   also   inhibit   flight   director, autopilot,   and   electric   trim   use   without illumination of the AP FAIL annunciator. 17.  Engine instruments – Check. 8-28.  BEFORE TAXIING. * 1.  CABIN signs – As required. * 2.  BLEED AIR VALVES – As required. * 3.  AFT BLOWER – As required. * 4.  Avionics – Check and set. * 5.  EFIS – TEST. H 6.  Flight controls/autopilot system – Check. a.  AP XFER switch – Select pilot’s side. b.  AP mode selector button (AP) – Press to engage autopilot. If unable to overpower the autopilot in any axis, do not use. c.   Flight  controls  –  Overpower  autopilot  in pitch, roll and yaw axis. d.  Auto trim – Check. (1)  Apply nose up force on control wheel –  Note  nose  down  trim  motion  after approximately 3 seconds. (2)  Apply   nose   down   force   on   control wheel  –  Note  nose  up  trim  motion after approximately 3 seconds. (3)  Press right rudder – Note left rudder trim motion after approximately 3 seconds. (4)  Press left rudder – Note right rudder trim motion after approximately 3 seconds. (5)  Select   HDG   mode   –   Observe   FD commands and control wheel motion correspond    to    movement    of    the heading selector knob. (6)  AP  DISC  &  TRIM  INTRPT  –  Press and release. Note autopilot disconnection, flashing AP annunciation,   and   aural   disconnect tone. e.  Manual electric trim – Check. (1)  Pilot  and  copilot  control  wheel  trim switches – Check. WARNING