TM 55-1510220-10 NOTE Extra    precision    values    are    always added  to  normal  values  regardless  of which  key  (N/S)  is  pressed  to  initiate the entry. The normal entry establishes the hemisphere. 10. INSERT/ADVANCE pushbutton Press.    Observe  latitude  and  longitude data is displayed in UTM and INSERT/ADVANCE   pushbutton   light extinguishes. NOTE The computer will convert coordinates in  the  overlap  area;  however  display values will reference appropriate zone. NOTE The  "W"  key  may  be  used  to  initiate easting    entries;    however    computer will  always  interpret  such  entries  as an  "E"  input.    "E"  will  be  displayed in normal UTM display. NOTE Extra    precision    values    are    always added    to    normal    values.        As    an example,    South    4,    476.995    m    will display   "4476S"   in   normal   display and  "995"  in  extra  precision  display. There is no rounding between the two displays. (b) To insert geographic coordinates of aircraft present position: NOTE Prior to pressing INSERT/ ADVANCE pushbutton, any incorrectly loaded data can be corrected    by    pressing    the    CLEAR pushbutton and loading correct data. 1. Data  selector  UIL  POS.    Observe  that prior   to   initial   load,      the   INSERT/ ADVANCE  pushbutton  annunciator  is illuminated. 2. To   load   latitude   data   Press   keys   in sequence,  starting  with  "N"  or  "S"  to indicate  north  or  south.    Example:  42' 54.0' North = N 4 2 5 4 0. Observe that latitude appears in the left data display as keys are pressed. 3. INSERT/ADVANCE pushbutton Press.  Observe pushbutton annunciator remains illuminated. 4. To    load    longitude  data  Press  keys  in sequence,  starting  with  "W"  or  "E"  to indicate     west     or     east.          Example: 87'54.9' West = W  8 7 5 4 9.  Observe that   longitude   appears   in   right   data display as keys are pressed. 5. INSERT/ADVANCE pushbutton Press.  Observe pushbutton annunciator extinguishes. NOTE The  computer  retains  all  information from  the  previous  NAV  mode.    Only present   position   has   to   be   reloaded. Waypoint  and  TACAN  does  not  need to be reloaded if it is correct. (5) To program destinations or TACAN coordinates: NOTE If  latitude  and  longitude  coordinates are    being    used,    skip    step    a    and proceed  with  step  b.    Enter  all  of  the data     for     a     given     destination     or TACAN  before  starting  to  enter  data for another. (a) Insertion of UTM waypoint coordinates: 1. Data  selector  UTM  WY  PT.    If  this  is the first insertion   into   the   selected waypoint   since   turn-on,   observe   data displays indicate "0" (N) and approximately "31'166"(E).  Otherwise, data displays will indicate last coordinates inserted into related waypoint. Change 2  3-54