TM 55-1510-222-10 (p)   Distance  and  time  to  waypoint  other  than next waypoint 1. WYPT CHG pushbutton - Press. Observe WYPT CHG and INSERT/ADVANCE pushbutton annunciator illuminates. 2. Key 0 - Press. Observe FROM side of TO-FROM data display changes to 0. 3. Key corresponding to desired waypoint - Press. Observe TO side of TO-FROM data display changes to desired waypoint number. NOTE Do not press INSERT/ADVANCE push-  button.    This  would  cause  an immediate flight plan change. 4. Data selector - DIS/TIME. Observe  distance  to  desired  waypoint  appears  in  left data  display  to  nearest  nautical  mile.    Time  to  reach desired   waypoint   at   present   groundspeed   appears   in right data display to nearest tenth of a minute. 5. CLEAR pushbutton - Press. Observe   INS   returns   to   normal   operation.      Observe INSERT/ADVANCE and WYPT CHG pushbutton annunciators   extinguish.      Waypoints   defining   current navigation leg appear in TO-FROM display. (q)   Distance     and     time     between     any     two waypoints: 1. WYPT CHG pushbutton - Press. Observe WYPT CHG and INSERT/ADVANCE pushbutton annunciators illuminate. 2. Keys corresponding to desired waypoints - Press in sequence. Observe   desired   waypoint   numbers   appear   in   TO- FROM data display as keys are pressed. 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   groundspeed 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 annunciator  extinguishes;.    Waypoints  defining  current navigation leg appear in TO-FROM 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   TO-FROM   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 30 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   annunciators   illuminate.      Station   number flashing discontinues. 6. Key  indicating  desired  TACAN  station number - Press. Observe number will appear in left digit location of TO- FROM data display. NOTE If     wrong     key     is     pressed,     press CLEAR;   displays   will   revert   to   that indicated in step 2. 7. INSERT/ADVANCE pushbutton ·- Press. 3-58