k. CDU Validity Checks For UTM Coordinate
The CDU checks the parameters of all data en-
tered through the scratchpad. Any non-valid characters
are flagged as erroneous. Valid parameters are as shown
in table 3-19.
UTM Coordinate Data Valid Entries
1 60 for the first two characters. C H, J N and P X for the third character.
A H, J N and P V for the most significant character.
E or W and 0 180.0 degrees.
AU, BE, EV, IN, C0, C6 and MA. MA is not currently utilized.
1 19 and H and 0. H and 0.are synonymous.
l. LATT/LONG Coordinate Entries for Waypoint
LATT/LONG coordinates, including mag-
netic variation, may be entered into the waypoint coordi-
nates as a single character string. The following is a typi-
cal format used when entering LATT/LONG coordinates
and magnetic variation.
74 degrees 25.9 minutes
120 degrees 57.6 minutes
10.5 degrees East Magnetic
When LATT/LONG and magnetic variation are all en-
tered, the required sequence is latitude, longitude, then
A complete entry of LATT/LONG coordinates and mag-
netic variation data is not required under all circum-
stances. Data entered in the scratchpad is always left jus-
tified. The following rules apply when an incomplete set of
LATT/LONG coordinates and magnetic variation data is
to be entered into the CDU scratchpad.
Leading zeros are required when entering
degrees or minutes of latitude and longi-
tude, i.e., N0905.5W01010.3 represents an
entry of 9 degrees 5.5 minutes North lati-
tude and 10 degrees 10.3 minutes West lon-
Rule 1 Latitude Range of Degrees. South latitude range
for entering degrees is 00 80 North latitude range for en-
tering degrees is 00 84.
Rule 2 Longitude Range of Degrees. The range for en-
tering degrees is 000 180.
Rule 3 Latitude Change. A change in latitude must be
accompanied by a change in longitude. Entry of magnetic
variation is optional. If magnetic variation is not entered,
its value defaults to the value associated with present
Rule 4 Magnetic Variation Change. A change can be
made to magnetic variation without changing LATT/LONG
coordinate data or affecting their values.
When an incomplete set of LATT/LONG coordi-
nates and magnetic variation is entered into PPOS, the
following exception applies:
A change in latitude must be accompanied
by a change in longitude. Magnetic variation