TM 55-1510-219-10 i.    Present position data Insert. NOTE After  present  position  'has  been inserted and computer has advanced   to   state   "7",   present position     cannot     be     reinserted without    downmoding    to    STBY and restarting alignment. j.    Data selector DSRTK/STS (Observe   that   the   left   data   display   indicates   the desired  track  stored  in  computer  memory  and  that  the right data display indicates status "-194.") NOTE If the fourth digit from the right, in the   right   data   display   is   blank, then a valid heading has not been stored.        Proceed    with    normal preflight procedure. k.    Monitor  the  right  data  display  for  a change  from  alignment  state  "9"  to alignment   state   "8".      This   will   be indicated by a reading of "--184". l.    Monitor   the   right   data   display   for malfunction codes (table 3-5). (Loss   of   26   VAC   is   indicated   by   an   illuminated WARN lamp and a reading of ".03184" in the right-hand display.    An  inoperative  magnetic  compass  system  is indicated by an extinguished WARN lamp and a reading of ".03184" in the right-hand display.) NOTE If above displays appear, a stored heading   alignment   may   not   be possible. m.    If    there    are    malfunction  codes, proceed to ABNORMAL PROCEDURES in this chapter. n.    When alignment state "7" is reached, the INS will advance to the NAV mode. (Observe that "---05" will appear in the STS display.) NOTE To  achieve  best  accuracy,  engine start   and   heavy   loading   activity should be delayed until entry into NAV mode. NOTE With the data selector in either the L/L    WY    PT    or    UTM    WY    PT position,    waypoint    and    TACAN station data may be loaded at any time  after  turn-on.    The  operator should    occasionally    switch    the data   selector   to   DSRTK/STS   to monitor  system  status  indicators in the right data display. (2) (CDU)  AUTO/MAN/TEST    switch  Press and hold.  Confirm: 1.    Left and right data displays indicate "88°88.8   N/S"   and   "88°88.8   E/W" respectively. 2.    FROM-TO display is "8.8". 3.    Following pushbuttons and lamps illuminate: ROLL LIM, HOLD, INSERT/ADVANCE,   WYPT CHG, ALERT,  BAT  (on  CDU  and  MSU), WARN and READY NAV. (3) TEST   switch   Release.      (Observe   data displays indicate coordinates in computer memory; also all   lamps   and   pushbuttons   lighted   in   step   7   except INSERT/ADVANCE pushbutton extinguish.) (4) Appropriate grid coefficients Verify loaded (if UTM coordinates are to be used.) (5) Verify UTM grid coefficients. 1.  Data selector UTM WYPT. 2.  Keys "5" and "9" Press simultaneously. Observe FROM-TO display is blank.  Earth flatness coefficient  appears  in  left  display.    The  relative  earth radius, in meters, appears in right display.) NOTE These   values   are   retained   from turn-on to turn-on unless changed by operator. 3.    Verify    that    values    correspond    to those   required   for   spheroid   being used. 3-48