TM 55-1510-219-MTF
PROCEDURE TROUBLESHOOTING REFERENCE
(2)
INSERT/ADVANCE key - Depress.
(3)
Left-hand and right-hand displays - Read arc-seconds
related to present inertial position to the nearest a tenth
of a second.
(4)
HOLD key - Depress to return to INS normal operation.
h. Magnetic variation - Check as follows:
(5)
Keys 3 and 9 - Depress simultaneously.
(6)
Right-hand display - Read magnetic variation to a tenth
of an arc-minute. Compare with local values.
NOTE
While operating in the NAV mode, magnetic variation
is computed when aircraft roll is less than 9° and the
magnetic heading input is valid (absence of error
code 17).
(7)
DATA/SELCTOR - Momentarily set to any position
except L/L WYPT to return to normal INS display
mode.
i.
Distance and Time to Next Waypoint - Check as follows:
4-15
