TM 55-1510-222-10 NOTE • Extra precision values are added to normal values and normal displays are not rounded off. • Normal longitude-latitude coordinates must always be loaded prior to extra precision values. • Directions  N  or  S  and  E  or  W  are established during normal coordinate  entry.    Either  key  may be   used   to   initiate   entry   during extra   precision   loads   and   values will   be   added   to   extra   precision values without affecting direction. • It  is  characteristic  of  the  computer display    routine    to    add    0.2    arc- seconds to any display of 59.9 arc- seconds.      Value   in   computer   is loaded by operator. 14.  Proceed to step 6 in procedure:  Normal Geographic Present Position Check and Update. (c)   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    annunciator    illuminates. Coordinates  in  data  display  freezes  at  values  present when HOLD pushbutton was pressed. NOTE While HOLD pushbutton annunciator is illuminated, TACAN, GPS 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 annunciator 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 annunciator 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 pushbutton - Press. Observe INSERT/ADVANCE pushbutton annunciator 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. • The  extra  precision  values  are always added to normal values. • Any  data  inserted  when  HOLD pushbutton  annunciator  is  not illuminated 3-62