TM 1-1520-240-10
4-1-23
CAUTION
Keep the protective caps on the ANVIS
whenever it is not in use. Operate the AN-
VIS only under darkened conditions.
NOTE
Ensure ANVIS operator procedures have
been completed.
8. P-PGM/OP/CP-PGM switch — OP.
NOTE
The system ON and FAIL lights will not be
visible if the center console lights are turned
off.
9. ADJ/ON/OFF switch — ON. SYS ON and
FAIL lights illuminated and BIT will initiate
automatically.
10. FAIL light — Check. Light should go out
after ten seconds. BIT is complete.
NOTE
Allow 1 minute for display warmup. Display
intensity is preset to low each time ADJ/ON/
OFF switch is set from OFF to On.
If a fault is displayed in the DU, acknowledge fault and
re-run BIT to confirm fault. If the fault remains notify
AVUM personnel.
11. BRT/DIM switch — As desired.
12. DSPL POS control — As required. Center
display in field of view.
13. Display aligned to horizon — Check. Tight-
en OU clamp.
4-1-34. Operator Self Test (BIT).
1. BIT/ACK switch — Press to BIT and hold.
The ON and FAIL LIGHT will illuminate. At
end of BIT, FAIL indicator will extinguish
(lamp will not be visible when center con-
sole lights are off).
2. Display Units(s) — Verify symbol generator
test mode software for CH-47 (figure 4-1-9).
3. BIT/ACK switch — Release.
4-1-35. Displayed System Faults.
The system self test is divided into power-up or operator
initialized built-in-test (BIT) and in-flight BIT. The faults
result as warnings and messages that blink at a rate of
two per second in the Display Units.
Part of the BIT is a periodic test that is performed auto-
matically along with normal system operation. This BIT
monitors and/or tests SDC functions and/or signals. A
failure of the SDC, NAV signals, pilot’s DU, or copilot’s
DU will illuminate the converter control FAIL light and
display a FAIl message CPM, SDR, SA, PS NAV, PDU or
CPDU on the Display Unit. An ATT (gyro invalid), IAS
(indicated air speed out of range), or MSL (MSL altitude
out of range) sensor failure warning message will be
displayed when condition exists. ATT, IAS, MSL, NAV,
PDU, CPDU, and all SDC faults can be cleared by setting
BIT/ACK switch to ACK.
The following helicopter status messages are also dis-
played.
1. The caption MST (first priority) indicates
operation of the mater caution warning
lamp. This message will disappear during
the reset of the main warning lamp opera-
tion.
2. The caption MEM (second priority) indi-
cates that the doppler data is not updated.
A previous computed data is available. This
message will appear simultaneously with
the MEM lamp on the doppler operating
panel.
3. The caption HOOK (third priority) indicates
the selected cargo hook has been opened
in the helicopter. The message will appear
after the reset of the master caution warning
light when any of the cargo hooks have
been opened.
Setting BIT/ACK switch to ACK will not clear MST, MEM,
HOOK status messages, or FIRE warning from the DU.
