TM 1-1510-218-10 8A-15 NOTE Pause  a  few  seconds  after  each  step  to allow time for the proper indications. (1)   Set alert controller more than 1000 feet above altitude indicated on pilot's altimeter.  The pilot's altimeter alert light should be extinguished. (2)   Decrease the alert controller to within 1000    feet    of    the    pilot's    altimeter setting.          The     alert     light     should illuminate. (3)   Decrease  the  controller  to  less  than 250  feet  above  the  pilot's  altimeter setting.          The     alert     light     should extinguish. (4)   Increase the controller to 300 ± 50 feet  above  the  pilot's  altimeter indication   and   check   that   the   alert light illuminates. (5)   Set the desired altitude. b.   Autopilot. (1)   Autopilot controller UP TRIM and DN TRIM    annunciators    –    Check    not illuminated. CAUTION A  steady  illumination  of  UP  TRIM  or  DN TRIM annunciator indicates that the automatic synchronization is not functioning and the autopilot should not be engaged. (2)   Turn knob – Center. (3)   ELEV TRIM switch – On. (4)   Control wheel – Hold to mid travel. (5)   AP  button  –  Press.     AP  ENGAGE and   YD  ENGAGE   annunciators   on autopilot  controller  will  flash.    Servo clutches will engage.  FD flag on ADI should be in view. (6)   Control movement – Check. (a)   Rudder pedals – Overpower slowly.  YD ENGAGE annunciator stops flashing. (b)   Control wheel – Overpower slowly in  both   pitch  and  roll  axis.    AP ENGAGE annunciator stops flashing.  FD flag on ADI retracts. If   autopilot   or   yaw   damper   disengages during overpower test or if AP ENGAGE or YD    ENGAGE    annunciator    continues    to flash,    the    system    is    considered    non- operative  and  should  not  be  used.    The elevator  trim  system  must  not  be  forced beyond the limits that are indicated on the elevator trim tab indicator. (7)   Elevator trim follow-up – Check. (a)   Control  wheel  –  Hold  aft  of  mid travel.      Trim   wheel   should   run nose    down    after    approximately 3 seconds. Trim down annunciator should illuminate after approximately 8 seconds. (b)   Control  wheel  –  Hold  forward  of mid travel.  Trim wheel should run nose up after approximately 3 seconds,    trim    up    annunciator should illuminate after approximately 8 seconds, and AP TRIM FAIL annunciator and MASTER WARNING lights should illuminate after approximately 15 seconds. (8)   AP/YD & TRIM DISC button – Press through  second  level.    Autopilot  and yaw  damper  should  disengage  and ELEV TRIM OFF annunciator should illuminate.    AP  ENG  and  YD  ENG annunciators    on    instrument    panel should flash five times. (9)   ELEV TRIM switch  –  OFF,  then  On. ELEV TRIM OFF annunciator should extinguish. (10)   AP    –    Re-engage    and    overpower another time. (11)   Turn  controller  –  Check  that  control wheel follows in each applied direction and center. (12)   Pitch     wheel     –     Check     that     trim responds  to  pitch  wheel  movement. UP TRIM and DN TRIM annunciators may illuminate. (13)   Heading  bug  –  Center  and  engage HDG.    Check  that  control  follows  a turn in each direction. WARNING