TM 1-1510-225-10
3C-56
continuous self-test is intended to advise only of major
component failures. The pilot initiated self-test is more
extensive than the continuous self-test and is
recommended as a check on system operation
whenever thunderstorm activity is noted on the
display. Press the TEST button when in the options
mode to manually initiate a test. Refer to Figure
3C-26.
Figure 3C-26. Test Options Mode
The system will initially power up with the
heading stabilization feature on. Should the aircraft's
heading gyro fail, the heading stabilization feature can
be turned off. To turn the heading display on or off,
press the NEXT button to highlight heading display
and press ON / OFF as appropriate. Refer to Figure
3C-27. When on, the heading of the aircraft will
appear as a digital indication at the top of the display
when in either weather mode.
Figure 3C-27. Heading Options
(7) Navaid Option. This option creates a
weather avoidance and navigational view. Refer to
Figure 3C-28. Using data from the LORAN or GPS,
this option provides simultaneous display of both
thunderstorm and flight information on the system
screen. The course line, selected waypoints, and a
course deviation indicator are graphically displayed.
Up to 10 waypoints may be displayed within the
selected nautical mile range. The CDI is calibrated to
indicate the course deviation up to 5 nm on either side
of the course line. Up to six user selectable data items
can be displayed. The navaid option is selected from
the main menu. Display range, groundspeed,
estimated time en route, bearing, crosstrack error, and
estimated time of arrival are automatically displayed.
The data or its position can be changed through the
Navaid Setup function on the Options menu.
Figure 3C-28. Navaid Option
The Navaid Setup grid lists 14 data items and
includes a blank space. Refer to Table 3C-6. Up to
six items can be displayed on the weather-mapping
screen. To select an item from the grid, move the
highlight by pressing the NEXT button. Refer to Figure
3C-29. The data items available for selection are
dependent upon the specific information provided by
the LORAN or GPS receiver. If an item on the grid is
not available from the receiver, that grid space will
include an asterisk.
Table 3C-6. Navigation Data Items
USER SELECTIONS
ABBR
Bearing to Active Waypoint
Brg
Crosstrack Error
XTK
Estimated Time of Arrival
ETA
