TM 1-1510-225-10
3B-61
acknowledge the annunciation and restore time as the
foremost annunciation.
(b) Freeze Position. When FREEZE is
selected on the Start 1 page, the position on the first
line of the page will be frozen. Typically, the GPS
position as displayed on this page will continuously
change as the GPS solution updates, even when
stationary on the ground. When frozen, the position
can be copied to other pages as desired or used to
begin initialization of the GPS receiver.
When a position is entered manually at line 1,
left or right, the position is automatically frozen for use.
To unfreeze, select the freeze line and select again.
The position frozen on the first line is used by the
system as waypoint 00 when loading a flight plan for
active use and as the starting position of the model
aircraft function. If waypoint 00 is not at the desired
starting position when initializing the system, enter the
desired position on the Start 1 page and either load a
new flight plan from the alternate flight plan or erase
the flight plan, see the following paragraph. The start
position will then be inserted as waypoint 00 in the
flight plan.
(c) Erasing System Data. On the Start 3
page, two selections are available to erase the active
flight plan and the user waypoint and markpoint lists.
The erase function requires confirmation by the
operator, and when confirmed will erase data from the
CDU’s memory. Erasure does not affect the flight
plans, user waypoint and markpoint lists, or radio
presets on the data cartridge.
(d) FMS Guidance Configuration. On the
Navigation Configuration 1 page, the current mode of
flight can be inspected by the pilot or overridden at
pilot request. Refer to Figure 3B-24 and Table 3B -16.
Under normal operation, the FMS will automatically
configure the FMS for the current mode of flight,
selecting
either
TERMINAL,
EN
ROUTE,
or
APPROACH. If a different flight mode is desired,
including OCEANIC, select the FLT MODE line select
to activate the desired mode. The flight mode not only
affects the scaling of deviation pointers, but also sets
the limits of the GPS RAIM function and navigation
accuracy limits. The system bank limit can be entered
on the Navigation Configuration 1 page. The bank
limit applies to FMS guidance during execution of the
flight plan.
(e) External Alert Configuration. On the
Navigation Configuration 2 page, alert thresholds can
be entered to configure the FMS alerts to desired limits
that the pilot wishes to maintain. When the FMS
reaches
the
alert
threshold,
an
appropriate
annunciation or external alert is provided to advise the
pilot. When crosstrack deviation is exceeded, an XTK
ALERT annunciation is provided until the aircraft is
maneuvered back into desired limits. When the speed
of the aircraft exceeds the speed alert limits, a
SPEED annunciation is provided until the aircraft’s
speed is throttled back within limits.
Figure 3B-24. Navigation Configuration Page
Access and Functions
