in last digit of right display.
AI will be set to approxi-
mately three times the num-
ber of hours in NAV.
(13.) Flight course changes.
Manual flight plan change inser-
WYPT CHG pushbutton -
Press. Observe WYPT CHG
2. Select new FROM and TO
3. WYPT CHG pushbutton -
waypoint numbers appear in
FROM-TO data displays as
keys are pressed.
Selecting zero as FROM waypoint will
cause desired track to be defined by com-
puted present position (inertial present
position plus fixes) and TO waypoint.
4. INSERT/ADVANCE push-
- Press. Observe
WYPT CHG and INSERT/
Waypoint zero always contains ramp
coordinates if no manual flight plan
changes are made. When a manual flight
plan change is made, present position at
instant of insertion is stored in waypoint
(14.) After landing procedures:
If INS will be unattended for an extended
period, it should be shut down.
Do not leave INS operating unless aircraft
or ground power and cooling air are avail-
able to system.
The INS may be shut down, downmoded
to STBY or ALIGN mode, or operated in
the navigation mode after landing. The
determining factor in choosing course of
action is expected length of time before
the next takeoff.
Do not tow or taxi aircraft during INS
alignment. Movement during alignment
requires restarting alignment.
(a.) Transient stops.
Action to be taken during a transient stop
depends upon time available and on
availability of accurate parking coordi-
nates (latitude and longitude.)
1. Realignment - INS operat-
(Recommended if sufficient time and accurate
parking coordinates are available.)
INS can be downmoded to perform a
realignment and azimuth gyro calibration.
Alignment to produce an alignment state
number of 5 can be accomplished in
approximately 17 minutes. During the 17
minute period, an automatic azimuth
gyro recalibration is determined on basis
of difference between inertial present
position before downmoding and inserted
present position. To obtain further refine-
ment of azimuth gyro drift rate, calcu-
lated on basis of newly computed error
data, INS can be left in alignment mode
for a longer period, allowing the align-
ment state number to attain some value
lower than 5.
2. Data selector - STBY, then
3. Present position coordinates
- Insert, according to proce-
I n s e r t i o n or