TM 55-1510-219-MTF
PROCEDURE TROUBLESHOOTING REFERENCE
F. AVIONICS FLIGHT CHECKS (CONT)
NOTE
The first digit from the left indicates "1" 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 55-1510-219-10 for
code definitions.
(5)
WARN lamp - Check dim.
l.
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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