TM 1-1510-218-10 3B-53 d.     Longitude  –  Input.    Use  East or  West  key  first,  followed  by the known longitude in degrees,  minutes  and  tenths of minute. e.     ENTER key  –  Press  to  enter the longitude into memory. 4.     EST GS:. a.     If on the ground, verify that 0 is displayed and press ENTER. b.     If    in    flight,    Input    estimated groundspeed, then press ENTER. 5.     APPROVE?   –   Press   ENTER   to approve   all   of   the   data   on   the initialization   page   and   enter   the data in memory.  The first page of the  flight  plan  menu  (FPLS)  will now appear. NOTE The  configuration  of  the  main  data  base can be reviewed at any time after initialization.  Since so many of the system capabilities depend upon the data base it is important    to    review    which    geographic region   and   which   navigational   elements within these regions are actually loaded in the data base. (4)   Reviewing the Data Base. CAUTION The data base should be reviewed prior to takeoff, since the system cannot provide a navigation  function  while  the  data  base is being loaded. 1.   DAT    key    –    Press    as    required    to display the DATA 2 menu page. 2.   Menu item UPDATE D/BASE – Select using  the  menu  selection  procedure.   The     UPDATE     D/BASE     page     will display. 3.   Menu item REVIEW D/BASE – Select.   The     REVIEW     D/BASE     page     will display.    Only  the  geographic  regions followed by an * are presently contained in the main data base. 4.   Desired   geographic   region   –  Select.   The   review   elements   page   for   the selected  region  will  display.    Only  the geographic  regions  followed  by  an  * are   presently  contained  in  the  main data base. 5.   DAT   key    –   Press   to   return   to   the review  data  base  page.    Navigational elements  stored  for  each  of  the  other geographic  regions  with  an  *  can  be viewed by repeating steps 4 and 5 as many times as necessary. (5)   Configuring the Data Base. CAUTION If  the  VOR  and  DME  (TACAN)  sensors  are to  be  utilized,  navaids  for  the  geographic regions in which flight is to occur must be loaded in the data base. NOTE Since   not   all   the   worldwide   data   on   the revision  diskette  can  be  contained  at  one time in the main data base, it is necessary to   select   which   geographic   regions   and which  navigational  elements  within  these regions  will  be  loaded  into  the  data  base.   The    data    base    does    not    need    to    be reconfigured  if  there  are  no  configuration changes from the previous loading. The    system    must    be    turned    on    and initialization    must    be    complete    before configuring the data base. 1.   Data loader cover – Open. 2.   Update    diskette    –    Insert    into    data loader.   The  diskette  will  not  lock  into place if it is positioned incorrectly. 3.   DAT key  – Press twice or as required to display the DATA 2 menu page. 4.   Menu item 5  – Select as follows: a.   Cursor   -   or   ¯    key    –   Press   to position cursor over item 5. b.   ENTER key  –  Press.    The  update data base page will display. 5.   Menu item 2  – Select as follows: a.   Cursor   -   or   ¯    key    –   Press   to position cursor over item 2.