TM 1-1510-225-10 3A-105 NOTE An  offset  waypoint  is  used  in  the  same manner as any other waypoint. The offset waypoint uses station declination,   if   available,   or   it   uses   the calculated magnetic variation of the parent waypoint.      All   points   defined   by   a   VHF navaid in the national/international airspace   system   are   based   on   the   VHF navaid    station    declination.        Since    the magnetic  variation  and  station  declination may not be the same at a given navaid, the calculated position and the defined position may differ. An   offset   waypoint   may   be   inserted   in   any waypoint ident field.  The offset waypoint is retained in memory  after  system  shutdown  only  if  entered  on  a stored flight plan. 1.   Cursor   –   Position   over   the   desired waypoint IDENT field. NOTE More  than  one  offset  waypoint  is  allowed from  one  parent,  using  *,  *1,  *A1,  etc.,  as identifying notation. 2.   Parent waypoint identifier  – Insert with an * following the entry. NOTE If   field   blinks,   parent   waypoint   does   not exist  in  CDU  memory  or  in  database  and must be defined on a Flight Plan page. 3.   ENTER key – Press. 4.   Desired radial – Insert. 5.   ENTER key – Press. 6.   Desired    distance    –    Insert    (nautical miles  and  tenths  of  a  nautical  mile, 399.9 maximum). 7.   ENTER key – Press. 8.   POS coordinates – Verify for reasonability. 9.   ENTER key – Press. z.   Database Update Procedures.  1.   Aircraft power – Apply. 2.   Current database update card  – Insert into CDU. 3.   ON Key – Press to turn on system. 4.   To update, perform the following. CAUTION If  an  interruption  of  the  update  process  is desired,  remove  the  update  disk.    Do  not turn off the power to stop the update. a.     1  key   –  Press  to  select  BEGIN UPDATE,  if  required.  If update is not   desired,   press   the   2  key  to restart the  system. b.     ENTER key – Press. The Updating Database page appears indicating database memory initialization. NOTE After initialization, the message COMPLETE     and     the     changing     update percentage    appear     indicating     that     the update is in progress. If update is successful: c. ENTER   key    -   Press   to   restart navigation or turn system off. If  the  database  update  fails,  the  error  message FAILED will be displayed.  Press the 1 key to retry the update or use the following procedure. NOTE Sometimes   when   a   retry   is   initiated,   a display such as CHECKING FOR DATABASE CARD may appear momentarily. 5.   Update card – Remove. 6.   System – Turn OFF. 7.   Update card – Re-insert into CDU. 8.   System – Turn ON and retry update using update procedure. 9.   If  the  update  card  is  the  wrong  database type, the message CARD INVALID will be displayed.  Press the 1 key to retry update or use the following procedure.