DOC AIRBUS | TSM A320FAltitude or Airspeed Disagree between the CAPT PFD or F/O PFD and Standby Horizon Indicator or ISIS (Aircraft with RVSM capability on the three ADIRUs)
TASK 34-13-00-810-998-B
Altitude or Airspeed Disagree between the CAPT PFD or F/O PFD and Standby Horizon Indicator or ISIS (Aircraft with RVSM capability on the three ADIRUs)
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 34-13-00-700-054-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:32:32 UTC
Altitude or Airspeed Disagree between the CAPT PFD or F/O PFD and Standby Horizon Indicator or ISIS (Aircraft with RVSM capability on the three ADIRUs)
1. Possible Causes
- PROBE-L STATIC, 1 [7DA1]
- PROBE-L STATIC, 2 [7DA2]
- PROBE-R STATIC, 1 [8DA1]
- PROBE-R STATIC, 2 [8DA2]
- SENSOR-ANGLE OF ATTACK, 1 [3FP1]
- SENSOR-ANGLE OF ATTACK, 2 [3FP2]
- ADM-R STATIC PRESSURE [19FP4]
- ADM-L STATIC PRESSURE [19FP5]
- ADM-R STATIC PRESSURE [19FP6]
- ADM-L STATIC PRESSURE [19FP7]
- PROBE-L STATIC, 3 [7DA3]
- PROBE-R STATIC, 3 [8DA3]
- SENSOR-ANGLE OF ATTACK, 3 [3FP3]
- PRESS SW-CABIN PRESS DET [14WN]
- ADM-STBY STATIC PRESSURE [19FP8]
- IND-ISIS [22FN]
- PROBE-PITOT, 1 [9DA1]
- PROBE-PITOT, 2 [9DA2]
- PROBE-PITOT, 3 [9DA3]
- ADM-L TOTAL PRESSURE [19FP1]
- ADM-R TOTAL PRESSURE [19FP2]
- ADM-STBY TOTAL PRESSURE [19FP3]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 34-14-00-810-996-A | NAV IR X FAULT or NAV ADR X FAULT ECAM Warning without Maintenance Message |
| AMM 30-31-00-710-001 | Operational Test of the Probe Ice Protection |
| AMM 30-31-00-720-001 | Functional Check of the Insulation Resistance of the Pitot Probe Heater |
| AMM 34-10-00-170-001 | Flushing of the Principal Total Pressure Lines |
| AMM 34-10-00-170-002 | Flushing of the Principal Static Pressure Lines |
| AMM 34-10-00-170-003 | Draining and Flushing of Standby Pneumatic Circuits |
| AMM 34-11-15-000-001 | Removal of the Pitot Probe |
| AMM 34-11-15-200-001 | Inspection/Check of the Pitot Probe |
| AMM 34-11-15-400-001 | Installation of the Pitot Probe |
| AMM 34-11-16-000-001 | Removal of the Static Probe |
| AMM 34-11-16-400-002 | Installation of the Static Probe |
| AMM 34-11-17-000-001 | Removal of the Air Data Module |
| AMM 34-11-17-400-001 | Installation of the Air Data Module |
| AMM 34-11-19-000-001 | Removal of the Angle of Attack Sensor |
| AMM 34-11-19-400-001 | Installation of the Angle of Attack Sensor |
| AMM 34-13-00-720-009 | Functional Test of the Altitude and Airspeed Data (A/C without RVSM capability on ADIRU 3) |
| AMM 34-13-00-720-010 | Functional Test of the ADM Accuracy |
| AMM 34-13-00-790-002 | Leak Test of the Principal Static and Total Air Data System |
| AMM 34-21-00-720-001 | Functional Test of the Standby Airspeed Indicator |
| AMM 34-21-00-720-002 | Functional Test of the Standby Altimeter |
| AMM 34-21-00-790-001 | Low-Range Leak Test of the Standby Pneumatic Circuits |
| AMM 34-22-25-000-001 | Removal of the ISIS Indicator |
| AMM 34-22-25-170-001 | Draining and Flushing of the Standby Static and Standby Total Pressure lines (ISIS) |
| AMM 34-22-25-400-001 | Installation of the ISIS Indicator |
| AMM 34-22-25-720-001 | Functional Test of the ISIS Indicator |
| AMM 34-22-25-790-001 | Low range Leak Test of the Standby Pneumatic circuits |
| AMM 52-73-12-000-001 | Removal of the Cabin-Pressure Detection Pressure-Switch |
| AMM 52-73-12-400-001 | Installation of the Cabin-Pressure Detection Pressure-Switch |
| SRM 53001101 | |
| TSM TASK 34-13-00-03 | AIR DATA - TASK SUPPORTING DATA |
Subtask 34-13-00-700-054-A ** ON A/C NOT FOR ALL
A. If one of the ECAM warnings that follow is shown:
Subtask 34-13-00-720-052-A ** ON A/C NOT FOR ALL - NAV IR 1 FAULT
- NAV IR 2 FAULT
- NAV IR 3 FAULT
- NAV ADR 1 FAULT
- NAV ADR 2 FAULT
- NAV ADR 3 FAULT,
do the troubleshooting procedure (Ref. TSM TASK 34-14-00-810-996).
B. Test
(1) Check of the altitude/airspeed tolerances34-13-00-03 TSM TASK 34-13-00-03 .
(a) If the values are in the tolerances:
1 Do a visual check to make sure that the quick-disconnect couplings, on the hose of each ADM are correctly attached to their related probes.
2 Connect the disconnected quick-disconnect couplings, if necessary.
3 After the connection, make sure that you can see the colored ring on the quick-disconnect couplings.
4 Pull the connectors to make sure that they are correctly connected.
5 Do the the functional test of the altitude and airspeed data AMM 34-13-00-720-009.
4. Fault Isolation(1) Check of the altitude/airspeed tolerances
(a) If the values are in the tolerances:
- No other maintenance step is necessary.
1 Do a visual check to make sure that the quick-disconnect couplings, on the hose of each ADM are correctly attached to their related probes.
2 Connect the disconnected quick-disconnect couplings, if necessary.
3 After the connection, make sure that you can see the colored ring on the quick-disconnect couplings.
4 Pull the connectors to make sure that they are correctly connected.
5 Do the the functional test of the altitude and airspeed data AMM 34-13-00-720-009.
CAUTION:
IF THERE WAS AN AIRSPEED OR ALTITUDE DISCREPANCY REPORT ON THE PREVIOUS FLIGHT, DO A RESET OF THE TWO ELAC'S (OFF-ON OF THE ELAC 1 AND 2 PUSHBUTTON SWITCHES ON THE OVERHEAD PANEL) WITH THE THREE HYDRAULIC SYSTEMS DEPRESSURIZED.
Subtask 34-13-00-810-272-A ** ON A/C NOT FOR ALL A. If the test for altitude and airspeed data is in the tolerances:
(1) Do the inspection/check of the pitot probe AMM 34-11-15-200-001.
(2) Do the functional check of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(3) Do the flushing of the principal total pressure-lines AMM 34-10-00-170-001.
(4) Do the flushing of the principal static pressure-lines AMM 34-10-00-170-002.
(5) Do the draining and flushing of standby pneumatic circuits AMM 34-10-00-170-003.
(6) Do the leak check of the principal/main static and total air data-system AMM 34-13-00-790-002.
(7) Do the low-range leak test of the standby pneumatic circuits AMM 34-21-00-790-001.
Subtask 34-13-00-810-272-B ** ON A/C NOT FOR ALL (1) Do the inspection/check of the pitot probe AMM 34-11-15-200-001.
(2) Do the functional check of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(3) Do the flushing of the principal total pressure-lines AMM 34-10-00-170-001.
(4) Do the flushing of the principal static pressure-lines AMM 34-10-00-170-002.
(5) Do the draining and flushing of standby pneumatic circuits AMM 34-10-00-170-003.
(6) Do the leak check of the principal/main static and total air data-system AMM 34-13-00-790-002.
(7) Do the low-range leak test of the standby pneumatic circuits AMM 34-21-00-790-001.
A. If the test for altitude and airspeed data is in the tolerances:
(1) Do the inspection/check of the pitot probe AMM 34-11-15-200-001.
(2) Do the functional check of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(3) Do the flushing of the principal total pressure-lines AMM 34-10-00-170-001.
(4) Do the flushing of the principal static pressure-lines AMM 34-10-00-170-002.
(5) Do the draining and flushing of the standby static and standby total pressure-lines (ISIS) AMM 34-22-25-170-001.
(6) Do the leak test of the principal static and total air data-system AMM 34-13-00-790-002.
(7) Do the low-range leak test of the standby pneumatic circuits AMM 34-22-25-790-001.
Subtask 34-13-00-810-257-A ** ON A/C NOT FOR ALL (1) Do the inspection/check of the pitot probe AMM 34-11-15-200-001.
(2) Do the functional check of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(3) Do the flushing of the principal total pressure-lines AMM 34-10-00-170-001.
(4) Do the flushing of the principal static pressure-lines AMM 34-10-00-170-002.
(5) Do the draining and flushing of the standby static and standby total pressure-lines (ISIS) AMM 34-22-25-170-001.
(6) Do the leak test of the principal static and total air data-system AMM 34-13-00-790-002.
(7) Do the low-range leak test of the standby pneumatic circuits AMM 34-22-25-790-001.
B. If the test shows a different altitude value from ADR1 (compared to ADR2 and ADR3) or from ADR2 (compared to ADR1 and ADR3):
(1) Do the flushing of the principal static pressure-lines (ADM4 and ADM5 or ADM6 and ADM7 only) AMM 34-10-00-170-002.
(2) Do a visual check of the static probes:
(a) If one of these static probes is damaged, replace it:
(a) If one of these AOA sensors is damaged, replace it:
(5) Do the functional test of the ADM accuracy for ADM4, ADM5, ADM6 and ADM7 only AMM 34-13-00-720-010.
(a) If one value is different, replace the defective ADM:
Subtask 34-13-00-810-258-A ** ON A/C NOT FOR ALL (1) Do the flushing of the principal static pressure-lines (ADM4 and ADM5 or ADM6 and ADM7 only) AMM 34-10-00-170-002.
(2) Do a visual check of the static probes:
(a) If one of these static probes is damaged, replace it:
- PROBE-L STATIC, 1 [7DA1] , PROBE-L STATIC, 2 [7DA2] , PROBE-R STATIC, 1 [8DA1] or PROBE-R STATIC, 2 [8DA2] AMM 34-11-16-000-001 and AMM 34-11-16-400-002.
(a) If one of these AOA sensors is damaged, replace it:
- SENSOR-ANGLE OF ATTACK, 1 [3FP1] or SENSOR-ANGLE OF ATTACK, 2 [3FP2] AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
(5) Do the functional test of the ADM accuracy for ADM4, ADM5, ADM6 and ADM7 only AMM 34-13-00-720-010.
(a) If one value is different, replace the defective ADM:
- ADM-R STATIC PRESSURE [19FP4] , ADM-L STATIC PRESSURE [19FP5] , ADM-R STATIC PRESSURE [19FP6] or ADM-L STATIC PRESSURE [19FP7] AMM 34-11-17-000-001 and AMM 34-11-17-400-001.
- Replace the AOA1(2) sensor:
SENSOR-ANGLE OF ATTACK, 1 [3FP1] or SENSOR-ANGLE OF ATTACK, 2 [3FP2] AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
C. If the test shows a different altitude value from ADR3 (compared to ADR1 and ADR2):
(1) Do the draining and flushing of standby pneumatic circuits AMM 34-10-00-170-003.
(2) Do a visual check of the static probes:
(a) If one of these static probes is damaged, replace it:
(a) If the SENSOR-ANGLE OF ATTACK, 3 [3FP3] is damaged, replace it AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
(4) Do the low-range leak test of the standby pneumatic circuits AMM 34-21-00-790-001.
(5) Do the functional test of the standby altimeter AMM 34-21-00-720-002.
(6) Do the functional test of the ADM accuracy for ADM8 only AMM 34-13-00-720-010.
(a) If the value is different:
1 Replace the PRESS SW-CABIN PRESS DET [14WN] AMM 52-73-12-000-001 and AMM 52-73-12-400-001.
2 If the fault continues:
Subtask 34-13-00-810-259-A ** ON A/C NOT FOR ALL (1) Do the draining and flushing of standby pneumatic circuits AMM 34-10-00-170-003.
(2) Do a visual check of the static probes:
(a) If one of these static probes is damaged, replace it:
- PROBE-L STATIC, 3 [7DA3] or PROBE-R STATIC, 3 [8DA3] AMM 34-11-16-000-001 and AMM 34-11-16-400-002.
(a) If the SENSOR-ANGLE OF ATTACK, 3 [3FP3] is damaged, replace it AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
(4) Do the low-range leak test of the standby pneumatic circuits AMM 34-21-00-790-001.
(5) Do the functional test of the standby altimeter AMM 34-21-00-720-002.
(6) Do the functional test of the ADM accuracy for ADM8 only AMM 34-13-00-720-010.
(a) If the value is different:
1 Replace the PRESS SW-CABIN PRESS DET [14WN] AMM 52-73-12-000-001 and AMM 52-73-12-400-001.
2 If the fault continues:
- Replace the ADM-STBY STATIC PRESSURE [19FP8] AMM 34-11-17-000-001 and AMM 34-11-17-400-001.
- Replace the AOA1(2) sensor:
SENSOR-ANGLE OF ATTACK, 1 [3FP1] or SENSOR-ANGLE OF ATTACK, 2 [3FP2] AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
D. If the test shows a different airspeed value from ADR1 (compared to ADR2 and ADR3), from ADR2 (compared to ADR1 and ADR3) or from ADR3 (compared to ADR1 and ADR2):
(1) Do a visual check of the pitot probes:
(a) If one of these pitot probes is damaged, replace it:
(3) Do the draining and flushing of standby total pressure-lines AMM 34-10-00-170-003.
(4) Do the leak test of the principal/main static and total air data-system AMM 34-13-00-790-002.
(5) Do the low-range leak test of the standby pneumatic circuits AMM 34-21-00-790-001.
(6) Do the functional test of the standby airspeed indicator AMM 34-21-00-720-001.
(7) Do the operational test of the probe ice protection AMM 30-31-00-710-001.
(a) If the test gives a maintenance message, do the troubleshooting procedure related to the maintenance message.
(8) Do the functional check of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(9) Do the functional test of the ADM accuracy for ADM1, ADM2 and ADM3 only AMM 34-13-00-720-010.
(a) If one value is different:
Subtask 34-13-00-810-258-B ** ON A/C NOT FOR ALL (1) Do a visual check of the pitot probes:
(a) If one of these pitot probes is damaged, replace it:
- PROBE-PITOT, 1 [9DA1] , PROBE-PITOT, 2 [9DA2] or PROBE-PITOT, 3 [9DA3] AMM 34-11-15-000-001 and AMM 34-11-15-400-001.
(3) Do the draining and flushing of standby total pressure-lines AMM 34-10-00-170-003.
(4) Do the leak test of the principal/main static and total air data-system AMM 34-13-00-790-002.
(5) Do the low-range leak test of the standby pneumatic circuits AMM 34-21-00-790-001.
(6) Do the functional test of the standby airspeed indicator AMM 34-21-00-720-001.
(7) Do the operational test of the probe ice protection AMM 30-31-00-710-001.
(a) If the test gives a maintenance message, do the troubleshooting procedure related to the maintenance message.
(8) Do the functional check of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(9) Do the functional test of the ADM accuracy for ADM1, ADM2 and ADM3 only AMM 34-13-00-720-010.
(a) If one value is different:
- Replace the defective ADM: ADM-L TOTAL PRESSURE [19FP1] , ADM-R TOTAL PRESSURE [19FP2] or ADM-STBY TOTAL PRESSURE [19FP3] AMM 34-11-17-000-001 and AMM 34-11-17-400-001.
E. If the test shows a different altitude value from ADR3 (compared to ADR1 and ADR2):
(1) Do the draining and flushing of the standby static and standby total pressure-lines (ISIS) AMM 34-22-25-170-001.
(2) Do a visual check of the static probes:
(a) If one of these static probes is damaged, replace it:
(a) If the SENSOR-ANGLE OF ATTACK, 3 [3FP3] is damaged, replace it AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
(4) Do the low-range leak test of the standby pneumatic circuits AMM 34-22-25-790-001.
(5) Do the functional test of the ISIS indicator AMM 34-22-25-720-001.
(a) If the value is different:
1 Replace the PRESS SW-CABIN PRESS DET [14WN] AMM 52-73-12-000-001 and AMM 52-73-12-400-001.
2 If the fault continues:
(a) If the value is different:
1 Replace the PRESS SW-CABIN PRESS DET [14WN] AMM 52-73-12-000-001 and AMM 52-73-12-400-001.
2 If the fault continues:
Subtask 34-13-00-810-259-B ** ON A/C NOT FOR ALL (1) Do the draining and flushing of the standby static and standby total pressure-lines (ISIS) AMM 34-22-25-170-001.
(2) Do a visual check of the static probes:
(a) If one of these static probes is damaged, replace it:
- PROBE-L STATIC, 3 [7DA3] or PROBE-R STATIC, 3 [8DA3] AMM 34-11-16-000-001 and AMM 34-11-16-400-002.
(a) If the SENSOR-ANGLE OF ATTACK, 3 [3FP3] is damaged, replace it AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
(4) Do the low-range leak test of the standby pneumatic circuits AMM 34-22-25-790-001.
(5) Do the functional test of the ISIS indicator AMM 34-22-25-720-001.
(a) If the value is different:
1 Replace the PRESS SW-CABIN PRESS DET [14WN] AMM 52-73-12-000-001 and AMM 52-73-12-400-001.
2 If the fault continues:
- Replace the IND-ISIS [22FN] AMM 34-22-25-000-001 and AMM 34-22-25-400-001.
(a) If the value is different:
1 Replace the PRESS SW-CABIN PRESS DET [14WN] AMM 52-73-12-000-001 and AMM 52-73-12-400-001.
2 If the fault continues:
- Replace the ADM-STBY STATIC PRESSURE [19FP8] AMM 34-11-17-000-001 and AMM 34-11-17-400-001.
- Replace the AOA1(2) sensor:
SENSOR-ANGLE OF ATTACK, 1 [3FP1] or SENSOR-ANGLE OF ATTACK, 2 [3FP2] AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
F. If the test shows a different airspeed value from ADR1 (compared to ADR2 and ADR3), from ADR2 (compared to ADR1 and ADR3) or from ADR3 (compared to ADR1 and ADR2):
(1) Do a visual check of the pitot probes:
(a) If one of these pitot probes is damaged, replace it:
(3) Do the draining and flushing of standby total pressure-lines (ISIS) AMM 34-22-25-170-001.
(4) Do the leak test of the principal static and total air data-system AMM 34-13-00-790-002.
(5) Do the low-range leak test of the standby pneumatic circuits AMM 34-22-25-790-001.
(6) Do the functional test of the ISIS indicator AMM 34-22-25-720-001.
(a) If the value is different:
(a) If the test gives a maintenance message, do the troubleshooting procedure related to the maintenance message.
(8) Do the functional test of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(9) Do the functional check of the ADM accuracy for ADM1, ADM2 and ADM3 only AMM 34-13-00-720-010.
(a) If one value is different:
Subtask 34-13-00-810-277-A ** ON A/C NOT FOR ALL (1) Do a visual check of the pitot probes:
(a) If one of these pitot probes is damaged, replace it:
- PROBE-PITOT, 1 [9DA1] , PROBE-PITOT, 2 [9DA2] or PROBE-PITOT, 3 [9DA3] AMM 34-11-15-000-001 and AMM 34-11-15-400-001.
(3) Do the draining and flushing of standby total pressure-lines (ISIS) AMM 34-22-25-170-001.
(4) Do the leak test of the principal static and total air data-system AMM 34-13-00-790-002.
(5) Do the low-range leak test of the standby pneumatic circuits AMM 34-22-25-790-001.
(6) Do the functional test of the ISIS indicator AMM 34-22-25-720-001.
(a) If the value is different:
- Replace the IND-ISIS [22FN] AMM 34-22-25-000-001 and AMM 34-22-25-400-001.
(a) If the test gives a maintenance message, do the troubleshooting procedure related to the maintenance message.
(8) Do the functional test of the insulation resistance of the pitot probe heater AMM 30-31-00-720-001.
(9) Do the functional check of the ADM accuracy for ADM1, ADM2 and ADM3 only AMM 34-13-00-720-010.
(a) If one value is different:
- Replace the defective ADM: ADM-L TOTAL PRESSURE [19FP1] , ADM-R TOTAL PRESSURE [19FP2] or ADM-STBY TOTAL PRESSURE [19FP3] AMM 34-11-17-000-001 and AMM 34-11-17-400-001.
G. If the fault continues:
Subtask 34-13-00-720-053-A ** ON A/C NOT FOR ALL - Do a check to make sure that there is no impact on the fuselage around the AOA and the static probes SRM 53001101.
- Replace the AOA sensor of the related circuit AMM 34-11-19-000-001 and AMM 34-11-19-400-001.
H. Do the test given in Para. 3.