14.      INS
  Note: the aircraft must not be towed or taxied during alignment.
a.      Select each MSU switch to ALIGN.
b.      Press TEST button & check:-
figure 8 appears in all spaces of both data displays
all CDU lights, except keyboard and CLEAR lights illuminate.
NS appears in LH data display, EW in RH.
88 appears in FROM-TO indicator.
MSU READY NAV and BAT lights illuminate.
        Repeat on other CDU; note, test button interrogates
        computer which responds as above.
c.      Check CDU WARN light and MSU BAT light extinguished.
A 10 sec. illumination of the BAT light on the CDUs
during the align period indicates that battery power is operating normally.
d.      Load Present Position
e.      Set data selector to POS
Press North or South key for latitude as required.
Press numbered keys in sequence for Present Position Latitude
-check correct latitude in LH data display.
Press INSERT key-check that the loaded latitude presentation in the LH display is accurate to +/- 0.1’-
INSERT light stays on. Press East or West keys for longitude as required.
Press numbered keys in sequence for Present Position longitude
-check correct longitude in RH display.
Press INSERT key. Check:-
INSERT light extinguishes.
Present Position Lat. and Long. Appear in LH and RH displays respectively, to an accuracy of +/- 0.1’
Repeat for other INS
f.      At some convenient stage, copy the Present Position
    from no.2 CDU onto the flight log: then check this
    against the Present Position at the front of the
    Aerodrome Folder. This must be done whether the E/O
    has loaded Pres. Position himself or not.