TM 55-1510-219-10 Present   Position   Check   and Update." (d) UTM   present   position   check   and update: NOTE UTM  data  may  be  loaded  in  any order and, until final entry, a value may be reloaded. 1. Data selector UTM POS. (Observe    UTM    coordinates    of    present    position appear in data displays.) 2. HOLD pushbutton Press (when    aircraft    passes    over known position reference.) (Observe HOLD pushbutton light illuminates. Coordinates   in   data   display   freeze   at   values   present when HOLD pushbutton was pressed.) NOTE While   HOLD   pushbutton   light   is illuminated,  TACAN  and  data  link updates are inhibited. 3. Load    zone    and    easting    by pressing    keys    in    sequence, starting with "E". (Example:    Zone    16,    425    km    East    =    E16    425. Observe zone and easting in kilometers appear in right data display as keys are pressed.) 4. INSERT/ADVANCE pushbutton Press. (Observe INSERT/ADVANCE pushbutton light remains illuminated.) 5. Load     northing     by     pressing keys    in    sequence,    starting with   "N"   or   "S"   to   indicate north or south hemisphere. (Example:   North   4749   km   =   N   4749.      Observe northing  kilometers  appear  in  left  data  display  as  keys are pressed.) 6. INSERT/ADVANCE pushbutton Press. (Observe INSERT/ADVANCE pushbutton light remains illuminated.) 7. INSERT/ADVANCE pushbutton Press. (Observe  extra  precision  display  related  to  present position northing and easting, to nearest meter, appears in left and right data displays, respectively.) 8. Load   extra   precision   easting value    by    pressing    keys    in sequence, starting with "E". (Example:  297  m  East  =  E  297.    Observe  easting meters    appear    in    right    data    display    as    keys    are pressed.) 9. INSERT/ADVANCE push- button Press. (Observe INSERT/ADVANCE pushbutton light remains illuminated.) 10. Load  extra  precision  northing value    by    pressing    keys    in sequence, starting with "N" or "S". (Example:    901    m    North    =    N    901.    Observe Northing meters appear in left data display as keys are pressed.    The  value  is  always  added  to  normal  value regardless of which key (N/S) is pressed to initiate entry. Normal entry establishes the hemisphere.) NOTE The   "W"   key   may   be   used   to initiate  easting  entries;  however, the computer will always interpret such entries as an "E" input. NOTE The    extra    precision    values    are always added to normal values. NOTE Any    data    inserted    when    HOLD pushbutton lamp is not illuminated    will    be    rejected    by computer. 11. INSERT/ADVANCE pushbutton Press. (Observe INSERT/ADVANCE and HOLD pushbutton lights remain illuminated.  North position error and east position  error  in  kilometers  will  appear  in  left  and  right data displays, respectively.) 12. If   WARN      lamp   illuminates, proceed to step (13); otherwise  proceed  to  step  (9) in procedure: "Extra Precision Geographic   Present   Position Check and Update." 3-65