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.
Applicable circuit breakers -Check depressed.
Mode selector switch (fig. 3-24) ALIGN.
Confirm the following:
TO-FROM display (fig. 325) indicates
annunciator (CDU) illuminates.
seconds then extinguishes when INS
advances to alignment state "8".
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
brightness of CDU displays.
Data selector (CDU) L/L POS or UTM POS,
as desired. Observe coordinates of last
present position prior to INS shutdown appear
in data displays.
Aircraft must not be towed or taxied
during INS alignment. Movement of
this type during alignment causes
large navigational errors. If aircraft
is moved during alignment, restart
alignment by setting mode selector
switch to STBY, then back to ALIGN
and reinserting present position.
Passenger or cargo loading in the
aircraft could cause the type of motion
alignment. Any activity which causes
the aircraft to change attitude shall be
avoided during the alignment period.
Press and hold for test. Confirm the
following on CDU:
Left and right data displays indicate "88"88.8 N/S and
"88°88.8" E/W respectively.
TO-FROM display indicates "8.8".
The following pushbuttons and annunciators illuminate:
ROLL LIM, HOLD, INSERT/ ADVANCE, WYPT CHG,
ALERT, BAT (on CDU and MSU), WARN and READY
Release. Confirm the following: 3.
Data displays indicate coordinates in
Observe left-hand data display indicates
the desired track in computer memory
and right data display indicates status
alignment state "9" to alignment state
"8". Observe right data display will be
Monitor data display for malfunction
codes. Observe if the 26V 400 Hz
power is off, ".03184" will appear in
the right data display and WARN
annunciator illuminates. If magnetic
compass is off, ".03184" will appear in
annunciator is extinguished.
If there are malfunction codes,
Change 2 3-50