TM 1-1510-223-10 been  selected,  TGT  (green)  will  be  enunciated  on  the EHSL.  When the target alert feature has been selected, the area beyond the selected range and 7.5 degrees on either   side   of   aircraft   heading   is   monitored   for   radar returns of level 3 (red) or greater.  If a level 3 or greater return  is  detected  and  triggers  the  system,  TGT  will  be enunciated   in   amber   on   the   EHSL.      Target   alert   is selectable in all but the 300 nautical-mile range. (5)   Sector   scan   angle   pushbutton   selector switch.        The     alternate-action,     sector     scan     angle pushbutton  selector  switch  is  used  to  select  either  the normal   14   looks   per   minute   120-degree   scan   or   the faster   update   28   looks   per   minute   60-degree   sector scan. (6) Antenna  tilt  angle  control.    The  rotary antenna  tilt  angle  control,  placarded  TILT,  is  used  to select  the  angle  of  the  antenna  beam  with  relation  to earth  plane.    Clockwise  rotation  tilts  the  beam  upward from 0 to 15 degrees.  Counterclockwise rotation tilts the beam   down-ward   from   0   to   15   degrees.      The   scale range between +5 degrees and -5 degrees is expanded for ease of use. (7) Lightning sensor system mode selector switch. (a) OFF.    Disables   lightning   sensor system. (b) STBY.     In   the   standby   (STBY) mode,  lightning  data  is  not  displayed.    However,  the receiving    and    processing    equipment    is    active    and lightning strikes are being counted and accumulated. (c) LX.   The LX mode is the normal working mode of the lightning sensor system.  Lightning strikes are collected, processed, and displayed. (d) CLR/TST.      When    clear/test    is selected,  all  memory  of  past  strikes  and  symbols  are erased.      After   3   seconds   the   system   enters   the   test mode. In  the  test  mode,  simulated  lightning  signals  are fed  into  the  test  loop  in  the  antenna  and  a  lightning strike  is  simulated  at  a  bearing  of  45  degrees  at  25 nautical miles.  A lightning alert is also generated along the  outermost  range  ring  at  a  bearing  of  45  degrees. This  simulated  strike  will  progress  in  severity  through level three within 15 seconds of entry into the test mode. If  the  mode  selector  is  left  in  the  CLR/TST  mode,  the alert   and   strike   symbols   will   reduce   in   severity   and disappear.  The lightning rate symbol will disappear after approximately 2 minutes. NOTE The lightning sensor system antenna is used in this test and as a result, any real lightning activity   that   occurs   while   the   test   is   in operation may also be displayed. (8) Radar system mode selector switch. (a) OFF.  Turns the radar system off. (b) SBY.  Places the radar system in standby.    This  is  a  ready  state  with  the  antenna  scan stopped,   the   transmitter   inhibited,   and   the   memory erased.  STBY will be displayed on the EHSI. (c) WX.     Selecting   WX   places   the radar   system   in   the   weather   detection   mode.      WX (green) will be enunciated on the EHSL.  The system is fully  operational  and  all  internal  parameters  are  set  for enroute  weather  detection.    Automatic  or  variable  gain control may be used.  Radar display levels are depicted in  four  colors  as  described  in  figure  3-31.    If  WX  is selected   prior   to   the   expiration   of   the   initial   system warm-up    period    (approximately    45    seconds),    WAIT green)  will  be  enunciated  on  the  EHSI.    In  wait  mode, the  transmitter  and  antenna  scan  is  inhibited  and  the memory  is  erased.    Upon  completion  of  the  warm-up period,   the   system   will   automatically   switch   to   WX mode. (d) GMAP.    Selecting  GMAP  places the  radar  system  in  the  ground  mapping  mode.    The system  is  fully  operational  and  all  internal  parameters are set to enhance returns from the ground and reduce returns from weather targets. Weather    type    targets    are    not    calibrated when   the   radar   is   in   the   GMAP   mode. Because of this, the pilot should not use the GMAP mode for weather detection. As   a   constant   reminder   that   GMAP   has   been selected,  the  GMAP  legend  is  displayed  and  the  color scheme is changed to cyan, yellow, and magenta.  Cyan represents    the    least    reflective    return,    yellow    is    a moderate  return,  and  magenta  is  a  strong  return.    If ground mapping is selected prior to the expiration of the warm-up   period   (approximately   45   seconds),   a   white WAIT legend will be displayed.  In the WAIT mode, the transmitter  and  antenna  scan  will  be  inhibited  and  the memory  is  erased.    Upon  completion  of  the  warm-up period,   the   system   will   automatically   switch   to   the GMAP mode. (e) FP.   Selection  of  the  FP  position places    the    radar    system    in    the    flight    plan    mode permitting  the  display  of  navigation  data  on  the  EFIS with    radar    data    omitted.        This    position    allows    an extended MAP display range (up to 1200 nautical miles) to be selected for navigation data. 3-81