TM 55-1510-219-10 NOTE Do   not   press   INSERT/ADVANCE pushbutton.  This would cause an immediate flight plan change. 3. Data selector DIS/TIME. (Observe distance between desired waypoints appears   in   left   data   display   to   nearest   nautical   mile. Time   to   travel   between   desired   waypoints   at   present ground  speed  appears  in  right  data  display  to  nearest tenth of a minute.) 4. CLEAR pushbutton Press. (Observe INS returns to normal operation.) (Observe    WYPT    CHG    and    INSERT/    ADVANCE pushbutton    light    extinguishes.        Waypoints    defining current navigation leg appear in FROMTO data display.) (r) Distance to any TACAN station: 1. Data selector DIS/TIME. (Observe    distance    to    next    waypoint    to    nearest nautical   mile   is   in   left   data   display.      Time   to   next waypoint  to  nearest  tenth  of  a  minute  is  in  right  data display.) 2. Keys "7" and "9" Press simultaneously. (Observe  number  of  TACAN  station  being  used  for navigation   flashes   on   and   off   in   FROM-TO   display. Distance to TACAN station to nearest nautical mile is in left data display.  Time to next waypoint is in right data display.) 3. If  in  aided  TACAN    operation Monitor display. (Observe station number is selected every 15 seconds.) 4. If not in aided TACAN operation   Perform   steps   (5) through (7). 5. WYPT CHG pushbutton Press. (Observe INSERT/ADVANCE and WYPT CHG pushbutton  light  illuminates.    Station  number  flashing discontinues.) 6. Key indicating desired TACAN station number - Press. (Observe  number  will  appear  in  left  digit  location  of FROM-TO data display.) NOTE If   wrong   key   is   pressed,   press CLEAR; displays will revert to that indicated in step (2). 7. INSERT/ADVANCE pushbutton Press. (Observe INSERT/ADVANCE and WYPT CHG pushbutton   lights   extinguish.      The   loaded   digit   will appear in right position of FROM-TO display and will be flashing on and off.  Distance to that station to nearest nautical   mile   appears   in   left   data   display.      The   right display continues to display time to next waypoint.) 8. Data selector WIND, momentarily. (Returns INS to normal display mode.) NOTE If in aided TACAN operation and if the desired  station  is  not  being  selected, exit   aided   operation   per   procedure: "Switching    From    Aided    to    Unaided Inertial  Operation",  perform  steps  (1) (8), and then return to aided operation per procedure: "Aided TACAN Operation". (s) Coordinates of any waypoint: 1. Data   selector   L/L   WYPT   or UTM WYPT. 2. Waypoint thumbwheel Set desired   waypoint.      Observe following: (L/L    WYPT:    Latitude    and    longitude    of    desired waypoint, to a tenth of a minute, appear in left and right data displays, respectively.) (UTM   WYPT:   Northing   and   zone   with   easting   of desired waypoint, to a kilometer, appear in left and right data displays, respectively.) 3. INSERT/ADVANCE pushbutton   Press.      Observe following: (L/L    WYPT:    The    arc-seconds    related    to    desired waypoint,  latitude,  and  longitude,  to  a  tenth  of  an  arc- second, appear in left and right data displays, respectively.) (UTM  WYPT:  The  extra  precision  display  related  to desired    waypoint    northing    and    easting,    in    meters, appear   in   left   and   right   data   displays,   respectively.) 3-61