W DOC AIRBUS | TSM A320F

Loss of the Altitude Bus 1 of the RA Transceiver 2 Identified by the EFCS1 or the EFCS2


TASK 34-42-00-810-805-A
Loss of the Altitude Bus 1 of the RA Transceiver 2 Identified by the EFCS1 or the EFCS2


1. Possible Causes
  • XCVR-RA, 2 [2SA2]
  • wiring
  • ANTENNA-RA RCPTN, 2 [5SA2]
  • ANTENNA-RA XMSN, 2 [6SA2]
  • coaxial cable
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ESPM 2053230
AMM 27-96-00-740-001
BITE Test of the EFCS (Ground Scanning)
ASM 344202
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 34-42-33-000-001
Removal of the Radio Altimeter Transceiver
AMM 34-42-33-400-001
Installation of the Radio Altimeter Transceiver
3. Fault Confirmation
Subtask 34-42-00-865-054-A
A. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
121VUCOM NAV/RAD ALTM/21SA2K12
Subtask 34-42-00-740-056-A
B. Test
   (1) Do the BITE test of the EFCS (ground scanning) AMM 27-96-00-740-001.
4. Fault Isolation
Subtask 34-42-00-810-056-A
A. If the test gives the maintenance message RA2:
   (1) If the fault continues:
  • do a check and repair the wiring of the ALTITUDE BUS 1 from the XCVR-RA, 2 [2SA2] to the first terminal block ASM 344202.
     (a) If the fault continues:
       1 If the fault continues:
       2 If the fault continues:
Subtask 34-42-00-740-057-A
B. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:33:07 UTC