TM 55-1510-219-10 NOTE Aircraft  must  be  connected  to  a ground power unit if INS alignment   is   performed   prior   to engine starting.  In this event, the engines  must  not  be  started  until after the INS is placed in the NAV mode. 1.    Applicable  circuit  breakers   Check depressed. 2.    INS  Mode  selector  (MSU) ALIGN. Confirm following: a.    (CDU) FROM-TO  display indicates "1 2". b.    (CDU) INSERT/ADVANCE pushbutton light illuminates. c.    (CDU)  BAT    lamp    illuminates  for approx. 12 seconds, then extinguishes     when     in     alignment state 8. NOTE Avoid passenger or cargo loading or  any  activity  which  may  cause aircraft    to    change    position    or attitude     during     alignment.          If aircraft is moved during alignment,  it  will  be  necessary  to restart   alignment   by   setting   the mode selector to STBY, then back to  ALIGN  and  reinserting  present position data. 3.    (CDU) DIM knob Adjust for optimum brightness of CDU displays. 4.    (CDU)       AUTO/MAN/TEST switch AUTO. 5.    (CDU)   Data   selector   L/L   POS   or UTM POS, as desired. (Observe coordinates of last present position prior to INS   shutdown   appear   in   data   displays.)   NOTE   The stored heading procedure should have  been  performed within  the  last week. 6.      Perform      recommended      stored heading alignment preflight procedure: a.    Appropriate circuit breakers Depress (including those for magnetic compass system.) b.    (MSU) Mode selector NAV. (Observe  (CDU)  FROM-TO  display  indicates  "1  2", and INSERT/ADVANCE pushbutton illuminates.) NOTE Aircraft   must   not   be   towed   or taxied during INS alignment. Movement    of    this    type    during alignment causes large navigation errors.  If aircraft is moved during alignment,    restart    alignment    by setting   mode   selector   to   STBY, then back to ALIGN and reinserting present position. Passenger   or   cargo   loading   in   the   aircraft   could cause the type of motion which affects the accuracy of alignment.      Any   activity   which   causes   the   aircraft   to change  attitude  shall  be  avoided  during  the  alignment period. c.    (CDU) DIM knob Adjust for maximum brightness of CDU displays. d.    (CDU) AUTO/MAN/TEST switch AUTO. e.    (CDU)   Data   selector   UL   POS   or UTM POS. (Observe coordinates of last present position prior to INS turn-off appear in data displays.) f.    (CDU) AUTO/MAN/TEST switch Press   and   hold   for   test.      Confirm following on CDU: (Left  and  right  data  displays  indicate  "88°88.8  N/S" and "88°88.8 E/W" respectively.) (FROM-TO display indicates "8.8".) (The   following   pushbuttons   and   lamps   illuminate: ROLL   LIM,   HOLD,   INSERT/ADVANCE,   WYPT   CHG, ALERT, BAT (on CDU and MSU), WARN, and READY NAV.) g.    (CDU) AUTO/MAN/TEST switch Release.  Confirm following: (Data   displays   indicate   coordinates   in   computer memory; all lamps and pushbuttons illuminated in Step F except INSERT/ADVANCE pushbutton light go out.) h.    If  UTM  coordinates  are  to  be  used Verify that appropriate Grid coefficients have been loaded. 3-47