User's Manual Part 2

T
2
CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
Use or disclosure of information on this page is subject to the restrictions in the proprietary notice of this document.
6--28
Table 6--4. TCAS Fault Reporting and Corrective Actions
Status
Annunciator
Failure Possible corrective Action
TCAS
PASS
The T
2
CAS TCAS function
passes its own internal BITE
test
T
2
CAS TCAS function is operational. If other
annunciators are on, the problem is in the indicated
subsystem or aircraft wiring.
TCAS
FAIL
The T
2
CAS TCAS function
has failed its own internal
BITE test
Replace the T
2
CAS computer unit.
TOP
ANT
The top antenna DC
resistance test indicates a
failure
Remove the T
2
CAS computer unit. Use a multimeter
to measure the DC resistances indicated in Table 6--5
for the top antenna. Repair antenna cables or replace
the antenna as required.
BOT
ANT
The bottom antenna DC
resistance test indicates a
failure
Remove the T
2
CAS computer unit. Use a multimeter
to measure the DC resistance indicated in Table 6--5
for the bottom antenna. Repair antenna cable(s) or
replace the antenna as required.
HDG Heading input function not
used
Not applicable
TA
DISP
T raffic advisory display
discrete signals No.1 or No. 2
indicate a failure
Check wiring and power to TA display. (On both sides
of the Flight Deck, if two are installed.) Make sure
that RA/TA valid discrete 1 and 2 (RMP--7E and
RMP--7J) are <3.5 V dc to ground. Repair wiring or
replace display as required.
RA
DISP
Resolution advisory display
discrete signals No.1 or No. 2
indicate a failure
Check wiring and power to RA displays. Make sure
that RA valid discrete 1 and 2 (RMP--14C and
RMP--13E) are <3.5 V dc to ground. Repair wiring or
replace display as required.
RAD
ALT
Radio altitude source No.1 or
No. 2 is invalid or has failed
Check wiring and power to the radio altimeters. For
analog radio altimeters, make sure the RAD ALT No.1
and No.2 valid discrete (RMP--2K and RBP--3C) are
>18.5 V dc. Repair wiring or replace radio altimeter
as required.
XPDR
BUS
Mode S Transponder No.1 or
No. 2 is invalid or has failed.
Check wiring and power to the transponders. Check
for data on XT 429 bus No.1 and No.2 (RMP--14F/G
and RMP--14H/J). Repair wiring or replace
transponder as required. If the Single Mode S
T ransponder program pin (RMP--10D) is not grounded
in installations using --XX003, --XX004 TCAS
Computer Units, a XPDR Bus Fault may be
displayed.
ATT Attitude input function not
used.
Not applicable