TM 1-1510-223-10 touch  control  steering  (TCS)  switch  on  the  control  wheel and   maneuvering   the   aircraft   to   a   new   vertical   speed reference   and   then   releasing   the   switch.      The   vertical speed  reference  can  also  be  changed  by  the  use  of  the pitch wheel on the autopilot controller. When    the    vertical    speed    mode    is    engaged,    VS (green) will be annunciated on the EADI, and the vertical speed  target  will  be  displayed  in  the  lower  left  comer  of the EADI. When the vertical speed reference is changed by  using  the  pitch  wheel  on  the  autopilot  controller,  the EADI's    will    indicate    the    commanded    vertical    speed reference.  Actual aircraft vertical speed will be displayed on  the  vertical  speed  indicator.    Selecting  vertical  speed (VS) will reset all previously selected vertical modes. Vertical speed mode may be cancelled by: Depressing the VS pushbutton switch-indicator on the flight director mode selector Selecting another vertical mode Selecting the go-around mode Selecting the standby mode Coupling to the cross-side EFIS Selecting   an   alternate   ATT   source   on   the   display controller (14) Indicated airspeed hold mode.   Activation of   the   IAS   pushbutton   indicator-selector   switch   on   the flight director mode selector automatically commands the flight  director  to  maintain  the  present  indicated  airspeed. The  referenced  airspeed  can  be  changed  by  depressing the  touch  control  steering  (TCS)  switch  on  the  control wheel,    maneuvering    the    aircraft    to    a    new    indicated airspeed,  then  releasing  the  TCS  switch.    The  airspeed reference  can  also  be  changed  by  using  the  pitch  wheel on  the  autopilot  controller.    When  the  airspeed  mode  is engaged,  IAS  (green)  will  be  annunciated  on  the  EADI, and the indicated airspeed target will be displayed in the lower  left  comer  of  the  EADI.  Actual  aircraft  indicated airspeed   will   be   displayed   on   the   airspeed   indicator. When  the  indicated  airspeed  hold  mode  is  selected,  all previously selected vertical modes will be reset The indicated airspeed mode may be cancelled by: Depressing the IAS pushbutton switch-indicator on the flight director mode selector Selecting another vertical mode Selecting go-around Coupling to the cross-side EFIS (15) Altitude   hold   mode.      The   altitude   hold mode  is  a  vertical  flight  director  mode  which  is  used  to maintain  a  barometric  altitude  reference.    The  vertical command   for   altitude   hold   is   displayed   on   the   flight director   pitch   command   cue   on   the   EADI.   To   select altitude hold, depress the ALT pushbutton switch-indicator located    on    the    flight    director    mode    selector,    while operating     in     any     lateral     mode.     The     ALT     (green) annunciator will be illuminated on the EADI while altitude hold mode is active.  The vertical axis of the flight director will  maintain  the  barometric  altitude  at  the  time  of  mode engagement  The  reference  altitude  may  be  change  by depressing the touch control steering (TCS) switch on the control   wheel,   maneuvering   the   aircraft   to   the   desired altitude, then releasing the TCS switch. The altitude hold mode may be can be cancelled by: Moving the pitch wheel on the autopilot controller Depressing   the   ALT   pushbutton   switch-indicator   on the flight director mode selector Selecting any other vertical mode Coupling to the cross-side EFIS Selecting   an   alternate   ATT   source   on   the   display controller. (16)    Altitude    preselect    mode.         The    altitude preselect  (ALT  SEL)  mode  is  used  in  conjunction  with another vertical mode to achieve automatic capture, flare, and  level-off  onto  a  preselected  altitude.    The  ALT  SEL mode  is  armed  by  depressing  the  ALT  SEL  pushbutton switch-indicator on the flight director mode selector.  The desired   altitude   is   entered   into   the   altitude   preselector display window using the SET knob. When  armed,  the  ALT  SEL  mode  is  annunciated  on the    EADI.    Vertical    speed    hold    mode    (VS    HOLD), indicated airspeed hold (IAS), or pitch hold can be used to fly  to  the  selected  altitude.    When  reaching  the  bracket altitude,   the   system   automatically   switches   to   the   ALT SEL CAP mode and the previous pitch mode is cancelled. A  command  is  then  generated  to  asymptotically  capture the selected altitude.  The ALT SEL mode is cancelled in altitude hold (ALT) or after glideslope capture.  ALT SEL capture  is  annunciated  on  the  EADI  by  a  green  ASEL  at the vertical capture annunciation location.  To indicate the transition to capture, ASEL will be enclosed in a white box for 5 seconds. The aircraft will remain in the ALT SEL capture mode until the following conditions exist simultaneously: ALT error is less than 25 feet 3-55