TM 1-1510-218-10 3-82 CAUTION Persistent clusters of two or more discharge  points  indicate  thunderstorms.   There are several atmospheric phenomena that  can  cause  isolated  discharge  points.   Clusters  of  two  or  more  discharge  points indicate   thunderstorm   activity   when   they reappear    persistently    after    clearing    the screen. Additionally, should the heading stabilization fail, it is necessary to press the CLEAR button for properly oriented data following an aircraft heading change. Press the   MENU  button  to  return  to  the  main menu. NOTE The date is set before the time. (4)   Time/Date Mode.  The TIME/DATE mode can   be   selected   only   from   the   main   menu.      The time/date mode menu displays four items: stopwatch, elapsed time, time of day, and day, month, and year.   Refer   to   Figure   3-115.      When   first   selecting   the time/date mode, the stopwatch digits will be highlighted.  To use the  stopwatch function, press the START  button  to  start  or  stop.    Pressing  the   RESET  button  will  immediately  reset  the  timer.    To  use  the elapsed   time   feature,   press   the    NEXT   button   to highlight the elapsed time digits and press the START button   to   start   or   stop  the  counter.    Pressing  the RESET button will reset the elapsed timer. BFG BRT OFF TIME/DATE MENU NEXT START RESET Stopwatch : 00 : 00 : 00    Elapsed Time : 02 : 48 : 22 14 : 35 : 26 05   Feb   96 Figure 3-115.  Time/Date Mode To set the current date or the correct time, press the  NEXT  button to highlight the digits to be changed.   Press the  UP or DOWN button to step the digits to the proper   value.      When   either   the   time   or   date   are highlighted, the   RESET   and  START  button  legends are replaced with UP and DOWN. (5)   Options   Mode.    The  options  mode  can only  be  selected  from  the  main  menu.    The  system continuously    self-tests    many    functions.        Refer    to Figure 3-116.  Results are indicated by CONTINUOUS TEST:   OK   or   FAULT.      CONTINUOUS   TEST:   OK indicates  that  all  internal  self–test  items  have  been operating    properly.        The    continuous    self-test    is intended  to  advise  only  of  major  component  failures.   The  pilot initiated self-test is more extensive than the continuous  self-test  and  is  recommended  as  a  check on system operation whenever thunderstorm activity is noted on the display.  Press the  TEST button when in the options mode to manually initiate the test. BFG BRT OFF OPTIONS MENU NEXT TEST     Continuous Test : OK        HDG Stabilization : ON    Heading Display : ON Navaid Setup Figure 3-116.  Options Test Mode 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 3-117.      When   on,   the   heading   of   the   aircraft   will appear as a digital indication at the top of the display when in either weather mode.