TM 55-1510-221-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
G. AVIONICS FLIGHT CHECKS (CONT)
NOTE
The first digit from the left indicates "I" for NAV
mode. The second and third digits will be blank
unless a malfunction code Is indicated. The
fourth digit is used for stored heading and shall
be blank The fifth digit is decremented at
certain time intervals when using TACAN
update. This provides an indication of the
relative quality of position updating obtained
The sixth digit indicates operating mode and
will read "4" to indicate TACAN updating
(4)
If malfunction codes occur,
press and release the TEST
switch repeatedly, recording
all malfunction codes until the
second and third digits again
indicate an action or code, or
go blank Refer to TM 55-
1510-221-10 for code
definitions.
(5)
WARN lamp - Check dim.
m
UTM Position - Check as follows:
(1)
Data selector - UTM - POS
(2)
Left-hand display - Read northing in kilometers.
(3)
Right-hand display - Read zone, then easting in kilometers.
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