Loss of the Radio Altimeter Data to the TCAS

TASK 34-43-00-810-832-A
Loss of the Radio Altimeter Data to the TCAS

1. Possible Causes

CMPTR-TCAS [1SG]
ANTENNA-RA RCPTN, 1 [5SA1]
ANTENNA-RA XMSN, 1 [6SA1]
ANTENNA-RA RCPTN, 2 [5SA2]
ANTENNA-RA XMSN, 2 [6SA2]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-42-11-000-001	Removal of the Radio Altimeter Antenna
AMM 34-42-11-400-001	Installation of the Radio Altimeter Antenna
AMM 34-43-00-740-001	BITE Test of the TCAS
AMM 34-43-34-000-001	Removal of the TCAS Computer
AMM 34-43-34-400-001	Installation of the TCAS Computer

3. Fault Confirmation
Subtask 34-43-00-865-059-A ** ON A/C NOT FOR ALL

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	COM NAV/RAD ALTM/2	1SA2	K12
121VU	COM NAV/RAD ALTM/1	1SA1	K11
121VU	COM NAV/TCAS	4SG	K10

Subtask 34-43-00-740-104-A ** ON A/C NOT FOR ALL

B. Test
(1) Do the BITE test of the TCAS AMM 34-43-00-740-001.

4. Fault Isolation
Subtask 34-43-00-810-084-A ** ON A/C NOT FOR ALL

A. If the BITE test gives the maintenance message TCAS (1SG):

replace the CMPTR-TCAS [1SG] AMM 34-43-34-000-001 and AMM 34-43-34-400-001.
if the fault continues, do the fault isolation given in para. B.

Subtask 34-43-00-810-085-A ** ON A/C NOT FOR ALL

B. If the test does not give the maintenance message TCAS (1SG):
(1) pull-out the circuit breaker 1SA1 for radio-altimeter receiver 1
(a) if the fault clears:

replace the ANTENNA-RA RCPTN, 1 [5SA1] and ANTENNA-RA XMSN, 1 [6SA1] AMM 34-42-11-000-001 and AMM 34-42-11-400-001.

(b) if the fault continues:

replace the ANTENNA-RA RCPTN, 2 [5SA2] and ANTENNA-RA XMSN, 2 [6SA2] AMM 34-42-11-000-001 and AMM 34-42-11-400-001.

Subtask 34-43-00-740-106-A ** ON A/C NOT FOR ALL

C. Do the test given in para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:13 UTC