TM 1-1520-240-10
3-3-21
all waypoints are put in a list and the start and end way-
points are entered. Both sequence modes can be flown
in the order they are in the list or in reverse order. Direc-
tions will be displayed to the waypoint next on the list until
approximately 10 seconds before overflying the way-
point at which time the display will advance to the next
waypoint and the new waypoint number will blink for ten
seconds. One consecutive and one random sequence
may be stored in the system.
3-3-48. To-To Route Mode.
The system has the ability to provide steering information
onto a course defined by the start and end waypoints.
Only the second waypoint will be overflown. The distance
displayed is the distance to the course when outside 2
nautical miles of the course and the distance to the sec-
ond waypoint when inside 2 nautical miles of the course.
3-3-49. General Operating Procedures for Entering
Data.
The panel display consists of four line LCD readout. The
top line of the display is reserved for the display of Fly-To-
destination number and destination name/International
Civil Aeronautic Organization (ICAO) identifier, EPE in
meters, mode of GPS and mode of AN/ASN-128B opera-
tion and target store number. The remaining lines will
display data in accordance with the DISPLAY and MODE
switches. When depressing the KYBD key for the first
time in an entry procedure, the display freezes, kybd is
displayed in the bottom right corner indicating the display
is in the keyboard mode and the input field under key-
board control blinks. If it is not desired to change the
display field under control, the pilot can advance to the
next field of the display by depressing the KYBD key
again. Depressing ENT key (whether or not new data has
been entered) causes the display to blank momentarily
and return with the latest computed data. To abort a
keyboard operation, move the mode or display switch to
another position.
NOTE
All keys activate upon release after being de-
pressed. Keys should be depressed and im-
mediately released in one continuous motion.
a. Data Entry. To display a letter, first depress the LTR
key corresponding to the position of the desired letter on
a key. Then depress the key which contains the desired
letter. For example, to enter an L, first depress The LTR
RIGHT key, then depress the 4 key.
b. Keyboard Correction Capability. The last charac-
ter entered may be cleared by depressing the CLR key.
If the CLR key is depressed twice in succession, the field
is cleared but remains under control (indicated by blink-
ing) and the last valid data entered is displayed.
c. Destination Variation Constraint. The magnetic
variation associated with a destination must be entered
AFTER the coordinates for that destination are entered.
The order of entry for present position is irrelevant.
d. Impossibility of Entering Unacceptable Data. In
most cases the computer program will reject unaccept-
able data (for example, a MGRS area W1 does not exists
and will be rejected). If the operator attempts to insert
unacceptable data, the unacceptable data will be dis-
played on the panel and then the selected field will blink
after ENT key is pressed displaying the last valid data.
NOTE
The computer cannot prevent insertion of er-
roneous data resulting, for example, from hu-
man or map errors.
e. Procedure for Displaying Wind Speed and Direc-
tion.
NOTE
In MGRS mode, wind speed is displayed in
km/hr; in LAT/LONG mode, wind speed is dis-
played in knots. Wind direction is defined as
the direction from which the wind originates.
(1)
Set MODE switch to LAT/LONG (MGRS
may also be used).
(2)
Set DISPLAY switch to WINDUTC/DATA
and observe display.
(3)
The display indicates:
SP;XXXKn
DIR:XXX_
f. Procedure for Displaying/Entering UTC and Dis-
playing GPS Status.
(1)
Set MODE switch to LAT/LONG (MGRS
may also be used).
(2)
Set DISPLAY switch to WIND-UTC/DATA
and observe the wind speed/direction display.
(3)
Depress ENT key. Observe that the CDU
display indicates year XX, day XXX and indicates hours,
minutes, and seconds of UTC time: XX Hours, XX Min-
utes, XX Seconds.
(4)
To enter year, day, and time depress the
KYBD key to select the field for input shown as a blinking
field, enter the desired data and depress the ENT key.
(5)
To display GPS status depress the ENT to
display selection menu.
1>SEA CURRENT
2>SURFACE WIND
3>GPS STATUS
4>DATA LOAD end
(6)
To select the GPS STATUS page depress
the 3 key.