TM 1-1510-225-10 3B-199 The    system    will    initially    power    up    with    the heading  stabilization  feature  on.    Should  the  aircraft heading gyro fail, the heading stabilization feature can be  turned  off.    To  turn  the  heading  display  on  or   off, press  the   NEXT  button  to  highlight  heading  display and press  ON / OFF  as  appropriate.    Refer  to  Figure 3B-157.      When   on,   the   heading   of   the   aircraft   will appear as a digital indication at the top of the display when in either weather mode. Figure 3B-157.  Heading Options (6)   Navaid   Option.      This   option   creates   a weather  avoidance  and  navigational  view.    Refer  to Figure  3B -158.    Using  data  from  the  KLN-90B,  this option provides simultaneous display of both thunderstorm   and   flight   information   on   the   system screen.    The  course  line,  selected  waypoints,  and  a course  deviation  indicator  are  graphically  displayed.   Up to ten waypoints may be display with the selected nautical  mile  range.   The  CDI  is  calibrated  to  indicate the  course  deviation  up  to  5  nautical  miles  on  either side of the course line.  Up to six user-selectable data items can be displayed.  The navaid option is selected from  the  main  menu.    Display  range,  ground  speed, estimated time en route, bearing, crosstrack error, and estimated  time  of  arrival  are  automatically displayed.   The  data  or  its  position  can  be  changed  through  the Navaid Setup function on the Options menu. Figure 3B-158.  Navaid Option The  Navaid  Setup  grid  lists  14  data  items  and includes  a  blank  space.    Refer  to  Table  3B -111  for data    items    definitions.        Up    to    six    items    can    be displayed on the weather-mapping screen.  To select an  item  from  the  grid,  move  the  highlight  by  pressing the  NEXT button.  Refer to Figure 3B -159.    The  data items  available  for  selection  are  dependent  upon  the specific information provided by the KLN-90B receiver.   If an item on the grid is not available from the receiver, that grid space will include an asterisk. Table 3B-111.  Navigation Data Items ABBR USER SELECTIONS Brg Bearing to Active Waypoint ETA Estimated Time of Arrival ETE Estimated Time En Route GS Ground Speed Lat Latitude Long Longitude MESA Minimum Enroute Safe Altitude MSA Minimum Safe Altitude Mvar Magnetic Variation at Present Position Rng Range to Active Waypoint Time Stormscope System Stopwatch Trk Track WPT Waypoint Identifier XTK Crosstrack Error