W DOC AIRBUS | TSM A320F

Erroneous Radio-Altimeter Height Indication

TASK 34-42-00-810-844-A
Erroneous Radio-Altimeter Height Indication

1. Possible Causes
  • ANTENNA-RA RCPTN, 1 [5SA1]
  • ANTENNA-RA XMSN, 1 [6SA1]
  • coaxial cables between the RA transceiver 1 (2SA1) and the radio altimeter antennas
  • XCVR-RA, 1 [2SA1]
  • ANTENNA-RA RCPTN, 2 [5SA2]
  • ANTENNA-RA XMSN, 2 [6SA2]
  • coaxial cables between the RA transceiver 2 (2SA2) and the radio altimeter antennas
  • XCVR-RA, 2 [2SA2]
2. Job Set-up Information
 A. Consumable Materials
REFERENCE
DESIGNATION
(Material No.08BBD1)
Non Aqueous Cleaner-- Isopropyl Alcohol -
(Material No.14SBA1)
Textile-Lint free Cotton -
 B. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 34-42-00-810-850-A
Test of coaxial cables and replacement of antennas for the Radio-Altimeter side RA2 (2SA2)
ESPM 2052230
ESPM 2053230
ASM 344201
AWM 344201
ASM 344202
AWM 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 34-42-11-615-001
Cleaning of the External Surface of the Radio Altimeter Antennas
AMM 34-42-11-920-001
Radio Altimeter Antennas and Coaxial Cables Replacement
AMM 34-42-33-400-001
Installation of the Radio Altimeter Transceiver
3. Fault Confirmation
Subtask 34-42-00-700-054-A
A. Not applicable, you cannot confirm this fault on the ground.
4. Fault Isolation
Subtask 34-42-00-810-098-A
A. If the fault symptom is identified by the:
ECAM warning NAV RA DEGRADED and/or
ECAM warning L/G GEAR NOT DOWN and/or
Crew observation Radio Altimeter - Undue retard call out on approach and/or
Crew observation Radio Altimeter - Retard call out at take off and/or
Crew observation Radio Altimeter - NAV mode not engageable above 30ft and/or
Crew observation Radio Altimeter - Early flare and LAND/FLARE mode on ILS approach and/or
Crew observation Radio altimeter - Radio Altitude discrepancy between CAPT and F/O PFD and/or
Crew observation Radio Altimeter - Untimely TAWS alert and/or
Crew observation Radio Altimeter - Absence or interruption of auto call out and/or
Crew observation Radio Altimeter - LAND/FLARE mode not engageable in autoland and/or
Crew observation Radio Altimeter - AUTOLAND warning light in ILS approach and/or
Crew observation Radio Altimeter - Loss of ALPHA FLOOR and/or
Crew observation Radio Altimeter - Disconnection of high AOA autopilot not possible:

  • Clean the external surface of the radio altimeter antennas with Non Aqueous Cleaner-- Isopropyl Alcohol - (Material No.08BBD1) and a Textile-Lint free Cotton - (Material No.14SBA1) AMM 34-42-11-615-001.
NOTE: ECAM warning "NAV RA DEGRADED" will be reset in the Flight Phase 2 (engine start + 30s).
Subtask 34-42-00-810-099-A
CAUTION: DO NOT INTERCHANGE THE RA TRANSCEIVERS FOR THE NEXT FLIGHT. THE FAULT DETECTED WILL REMAIN.
B. After the subsequent flight, if one or more of these above entries is (are) shown in the log-book:
Troubleshooting installation of the Radio-Altimeter side RA1 (2SA1):

   (1) If you find signs of water on the connectors and coaxial cables of the antennas: dry them.
   (2) Make sure that the coaxial cables between the RA transceiver 1 (2SA1) and the radio altimeter antennas are in correct condition (no corrosion) ASM 344201: Pin AA/C and pin AB/C.
     (a) If the antenna coaxial cables are not in correct condition:
     (b) If the antenna coaxial cables are in correct condition:
Subtask 34-42-00-810-114-A
C. After subsequent flight, if one or more of these above entries is (are) shown in the log-book:
   (1) Do the test of the Radio Altimeter coaxial cables between the RA transceiver 1 XCVR-RA, 1 [2SA1] and the radio altimeter antennas ANTENNA-RA RCPTN, 1 [5SA1] and ANTENNA-RA XMSN, 1 [6SA1] as per ESPM 2052230 AWM 344201.
     (a) If the test of coaxial cables is not satisfactory:
     (b) If the test of coaxial cables is satisfactory:
  • Do the test of the coaxial cables and replacement of antennas for the Radio-Altimeter side RA2 (2SA2) (Ref. TSM TASK 34-42-00-810-850).
  • Go to Para. E.
Subtask 34-42-00-810-101-A
CAUTION: DO NOT INTERCHANGE THE RA TRANSCEIVERS FOR THE NEXT FLIGHT. THE FAULT DETECTED WILL REMAIN.
D. After the subsequent flight, if one or more of these above entries is (are) shown in the log-book:
Troubleshooting installation of the Radio-Altimeter side RA2 (2SA2):

   (1) If you find signs of water on the connectors and coaxial cables of the antennas: dry them.
   (2) Make sure that the coaxial cables between the RA transceiver 2 (2SA2) and the radio altimeter antennas are in correct condition (no corrosion) ASM 344202: Pin AA/C and pin AB/C.
     (a) If the antenna coaxial cables are not in correct condition:
     (b) If the antenna coaxial cables are in correct condition:
Subtask 34-42-00-810-115-A
E. After subsequent flight, if one or more of these above entries is (are) shown in the log-book:
   (1) Do the test of the Radio Altimeter coaxial cables between the RA transceiver 2 XCVR-RA, 2 [2SA2] and the radio altimeter antennas ANTENNA-RA RCPTN, 2 [5SA2] and ANTENNA-RA XMSN, 2 [6SA2] as per ESPM 2052230 AWM 344202.
     (a) If the test of coaxial cables is not satisfactory:
       1 After subsequent flight, if one or more of these above entries is (are) shown in the log-book:
     (b) If the test of coaxial cables is satisfactory:
Subtask 34-42-00-810-123-A
F. After subsequent flight, if one or more of these above entries is (are) shown in the log-book:
   (1) Install a new RA transceiver 2 (2SA2) AMM 34-42-33-400-001.
[Rev.8 from Aug 2018] 2026.04.04 04:33:11 UTC
"WTRUIB" 2025