TM 1-1510-218-10 3B-48 (2)   Airport Page.   The airport page is used to display  the  elevation  and  the  position  of  the  Airport Reference  Point  (ARP)  of  a  selected  airport.    If  the selected   airport   is   contained   in   the   data   base,   the above  information  will  be  displayed  when  the  airport ICAO  identifier  is  inputted.    User-defined airports can be   created   by   inputting   the   above   data   into   their respective fields and approving the page. ICAO AIRPORT IDENTIFIER: ^– Airport ICAO identifier or other user-defined airport identifier. ELEV: FT.     – Airport elevation to the nearest  10  feet  referenced  to sea level. LAT: LON:     – Position in latitude and longitude of the ARP. APPROVE?     – A cursor field used to approve a user defined airport. (3)   Data/Time Page.   The data displayed on the data/time page is for reference only and can not be changed from this page. DATE     – The  current  Greenwich  date in   the   sequence   day-month- year. GMT     – The  current  Greenwich  mean time. DEP TIME     – The    departure    time    that   is defined as the time (GMT) the system first calculated a groundspeed   that   exceeded 50 knots. FLT TIME     – The  flight  time  in  hours  and minutes,  which  is  defined  as the   elapsed   time   since   the system first calculated a groundspeed   that   exceeded 50 knots. (4)   Update   Data   Base   Page.       This   page serves  as  a  master  menu  for  initiating  three  types  of data base operations: reviewing the present configuration  of  what  is  currently  loaded  in  the  data base,   modifying   the   configuration   of   what   is   to   be loaded into the data base, and loading the data base with the data loader. SEL MENU ITEM: ^– The   number   associated   with the    desired    menu    item    is entered in this field. REVIEW D/BASE     – This menu item is selected to display  additional  data  base review pages that are used to review what is presently loaded in the data base.  The pages accessed via this menu item are the review data base page and the review elements page. SELECT D/BASE     – This menu item is selected to display  additional  data  base modification    pages    that    are used   to   configure   the   data base    prior    to    being    loaded with the data loader. NEXT UPDATE     – A   non-enterable   cursor   field that   displays   the   Greenwich date indicating when the next 28-day    data    base    revision update is due. LOAD D/BASE?     – A flashing cursor field  used to initiate  a  loading  of  the  data base with the data loader. *ON GROUND SELECT ONLY ^– *AFTER D/BASE COMPLETE (5)   Review  Data  Base  Page.    This  page  is used to review those regions of the world having data presently   loaded   in   the   data   base.      The   world   is divided into 10 regions, all of which are displayed on this  page.    The  data  base  cannot  be  modified,  from this page. SEL MENU ITEM     – The   number   associated   with the desired geographic region can be entered in this field to display    the    region's    review elements page. Directly   below   the   SEL   MENU   ITEM:,   the   10 regions display.  The * denotes that data is presently loaded in the data base for that region.  No * indicates that data for those regions have not been loaded in the data base. (6)   Review   Elements  Page.      This  page  is used to review the navigational elements loaded in the data  base  for  a  particular  region  of  the  world.    The data base cannot be modified from this page. NAVAID*     – Navaids   include   VORTAC's, VOR/DME's,  VOR's  TACAN's DME's and ILS DME's.  The * denotes  that  navaids  for  that region are presently loaded in