an option, enter his best esti-
mate of ground speed and
C, R, S,
or H fol-
by a nu-
A failure occurred and the
BACKUP mode used for
manual navigation (MN) is the
only means of valid naviga-
tion. The operator may use
the computer as a dead reck-
oning devise by entering
ground speed and track data.
The operator should update
present position as soon as
possible, because it is pos-
sible significant navigation er-
rors may have accumulated.
C, R, S,
or H fol-
by a nu-
A failure has occurred in the
system and the operator
should not use the system.
The 9V battery has failed. The
system will still operate but all
stored data will be lost when
set is turned off. Data must be
A failure occurred and the op-
erator should not use the sys-
3-3-16. Entering Data.
This initial data is inserted before navigating with the
a. Spheroid of operation, when using UTM coordi-
b. UTM or LAT/LONG coordinates of present posi-
c. Magnetic Variation (MAG VAR) of present posi-
d. Coordinates of desired destination - 0 through 5
and H: (6 through 9 are normally used for target store
locations; but may also be used for destinations.) It is not
necessary to enter all destinations in the same coordi-
It is not necessary to enter destinations un-
less steering information is required, unless it
is desired to update present position by over-
flying a destination, or unless a present posi-
tion MAG VAR computation is desired. If a
present position MAG VAR running update is
desired, destination MAG VAR must be enter-
ed. The operator may enter one or more des-
tination variations to effect the variation up-
date; it is not necessary for all destinations to
have associated MAG VAR entered.
e. Variation of destinations.
3-3-17. Entering Spheroid and/or Variation.
a. MODE selector UTM, LAT/LONG or BACKUP.
b. DISPLAY selector SPH-VAR.
c. DEST DISP thumbwheel P, numeral, or H as
d. KYBD pushbutton Press. Observe display
freezes and TGT STR indicator blanks. Press KYBD
pushbutton again and observe left display blanks. If no
spheroid data is to be entered, KYBD pushbutton
Press again, go to step g.
e. Spheroid data (table 3-3-3) Entry. (Example:
IN0). Press keys 3, 3, 5, 5, and 0. Left display should
f. ENT key Press if no variation data are to be
g. KYBD pushbutton Press, if variation data is to
be entered, and note right display blanks.
h. Variation data Enter. (Example: E001.2, press
keyboard keys 2, 2, 0, 0, 1 and 2. Press ENT key, the
entire display will blank and TGT STR number will re-
appear, display should indicate IN0 E001.2.)
If operation is to occur in a region with relative-
ly constant variation, the operator enters vari-
ation only for present position, and the com-
puter will use this value throughout the flight.
Table 3-3-3 Spheroid Data Codes