DOC AIRBUS | TSM A320FFailure of FWD Waste-Water Ice-Protection System
TASK 30-71-00-810-805-A
Failure of FWD Waste-Water Ice-Protection System
1. Possible Causes
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 30-71-00-710-058-A ** ON A/C NOT FOR ALL Subtask 30-71-00-710-058-B ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 30-71-00-810-055-A
Subtask 30-71-00-860-054-A
[Rev.8 from Aug 2018]
2026.04.04 04:29:46 UTC
Failure of FWD Waste-Water Ice-Protection System
1. Possible Causes
- CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU]
- DRAINMAST "F" [4DU]
- wiring
- CONTROL UNIT, POTABLE WATERICE PROTECTION- [3DW]
- SENSOR,TEMPERATURE- [40DU]
HEATER-ELEMENT WASTE-WATER DE-ICING (41DU) - HEATER-TAPE, [42DU]
- microfuse
- CONTROL UNIT, WASTE WATER ICE PROTECTION- [140DU]
- SENSOR,TEMPERATURE- [141DU]
HEATER ELEMENT-WASTE WATER DE ICING (142DU) HEATER ELEMENT-WASTE WATER DE ICING (146DU) HEATER ELEMENT-WASTE WATER DE ICING (147DU) - HEATER [48DU]
- HEATER [49DU]
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | SPRAY - COOLING |
| REFERENCE | DESIGNATION |
|---|---|
| AMM 30-71-00-710-002 | Operational Test of the Waste-Water Ice-Protection Heater-Elements |
| AMM 30-71-00-740-001 | BITE Test of the Drainmast Ice Protection (through CIDS SYSTEM/TEST) |
| ASM 307101 | |
| AMM 30-71-17-000-001 | Removal of the Waste-Water De-icing Sensor |
| AMM 30-71-17-400-001 | Installation of the Waste-Water De-icing Sensor |
| AMM 30-71-34-000-001 | Removal of the Waste-Water Ice-Protection Control-Unit |
| AMM 30-71-34-400-001 | Installation of the Waste-Water Ice-Protection Control-Unit |
| AMM 30-71-51-000-001 | Removal of the Drain Mast |
| AMM 30-71-51-400-001 | Installation of the Drain Mast |
| AMM 30-71-53-000-001 | Removal of the Waste-Water De-icing Heater Elements |
| AMM 30-71-53-000-003 | Removal of the Waste-Water De-icing Heater Elements |
| AMM 30-71-53-400-001 | Installation of the Waste-Water De-icing Heater Elements |
| AMM 30-71-53-400-003 | Installation of the Waste-Water De-icing Heater Elements |
| AMM 30-73-00-740-001 | BITE Test of the Potable Water Ice-Protection |
| AMM 30-73-34-000-001 | Removal of the Potable and Waste Water Ice Protection Control Unit |
| AMM 30-73-34-400-001 | Installation of the Potable and Waste Water Ice Protection Control Unit |
Subtask 30-71-00-710-058-A ** ON A/C NOT FOR ALL Subtask 30-71-00-710-058-B ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 30-71-00-810-055-A
A. If the green 'UNIT' LED of the CONTROL UNIT 5DU does not come on:
Replace the CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
Subtask 30-71-00-810-056-A Replace the CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
B. If the green HTR LED of CONTROL UNIT 5DU does not come on:
(1) Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
(2) If the fault continues:
(a) Replace DRAINMAST "F" [4DU] or only the cover or the heater tube assembly AMM 30-71-51-000-001 and AMM 30-71-51-400-001.
(3) If the fault continues:
(a) Do a check and repair the wiring between:
Subtask 30-71-00-810-058-A (1) Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
- Resistance of value the temperature sensor:
| TEMPERATURE | RESISTANCE VALUE IN OHM |
|---|---|
| -10deg C (14deg F) | 1784+-9 |
| 0deg C (32deg F) | 1854+-8 |
| +10deg C (50deg F) | 1926+-6 |
| +20deg C (68deg F) | 2000+-5 |
| +30deg C (86deg F) | 2076+-5 |
| +40deg C (104deg F) | 2153+-6 |
- Resistance value of the heater:
| PART NUMBER | RESISTANCE VALUE IN OHM |
|---|---|
| 4-60000H800-00 | 57+-3 |
| 4-60000H840-00 | 57+-3 |
| 4-60000H880-00 | 118+-5 |
| 4-60000H882-00 | 118+-5 |
| 4-60000H883-00 | 118+-5 |
(2) If the fault continues:
(a) Replace DRAINMAST "F" [4DU] or only the cover or the heater tube assembly AMM 30-71-51-000-001 and AMM 30-71-51-400-001.
(3) If the fault continues:
(a) Do a check and repair the wiring between:
- CONTROL UNIT 5DU connector A/4 and DRAINMAST 4DU connector A/D
- CONTROL UNIT 5DU connector A/5 and DRAINMAST 4DU connector A/E
- CONTROL UNIT 5DU connector A/8 and DRAINMAST 4DU connector A/B
- DRAINMAST 4DU connector A/C and GND
- DRAINMAST 4DU connector A/A and GND ASM 307101.
C. If the green 'UNIT' LED and the green 'HTR' LED of the CONTROL UNIT 5DU do not come on:
Do a check for the subsequent signals:
Replace the CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(2) If there is no GND:
Do a check and repair the wiring between CONTROL UNIT 5DU connector A/15 and GND ASM 307101.
(3) If there is no 115 VAC:
Do a check and repair the wiring between CONTROL UNIT 5DU connector A/14 and CB 1DU ASM 307101.
Subtask 30-71-00-810-057-A ** ON A/C NOT FOR ALL Do a check for the subsequent signals:
- 115 VAC at CONTROL UNIT 5DU connector A/14,
- GND at CONTROL UNIT 5DU connector A/15 ASM 307101.
Replace the CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(2) If there is no GND:
Do a check and repair the wiring between CONTROL UNIT 5DU connector A/15 and GND ASM 307101.
(3) If there is no 115 VAC:
Do a check and repair the wiring between CONTROL UNIT 5DU connector A/14 and CB 1DU ASM 307101.
D. If the green UNIT LED and the green HTR LED of CONTROL UNIT 5DU come on:
(1) Do the BITE test of the potable-water ice-protection system AMM 30-73-00-740-001.
(2) If the green III/IV LED of CONTROL UNIT 3DW does not come on:
(a) Do a check of the related microfuses.
(b) If the microfuses are OK:
1 Replace CONTROL UNIT, POTABLE WATERICE PROTECTION- [3DW] AMM 30-73-34-000-001 and AMM 30-73-34-400-001.
(c) If the fault continues:
1 Remove the insulation from around the SENSOR 40DU, HEATER 42DU and HEATER 41DU.
2 Apply SPRAY - COOLING to the SENSOR 40DU for at least 10 s.
3 Stop for approximately 120 s.
4 Do a check of the temperature of HEATER 42DU and HEATER 41DU.
5 If a heater stays cold:
a Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
(d) If the fault continues:
1 If HEATER 42DU and HEATER 41DU stay cold:
Replace SENSOR,TEMPERATURE- [40DU] AMM 30-71-17-000-001 and AMM 30-71-17-400-001.
2 If HEATER 41DU stays cold:
ReplaceHEATER-ELEMENT WASTE-WATER DE-ICING (41DU) AMM 30-71-53-000-001 and AMM 30-71-53-400-001.
3 If HEATER 42DU stays cold:
Replace HEATER-TAPE, [42DU] AMM 30-71-53-000-001 and AMM 30-71-53-400-001.
(e) If one microfuse is not OK:
1 Do a check for a short circuit ASM 307101.
2 Replace the microfuse .
Subtask 30-71-00-810-057-B ** ON A/C NOT FOR ALL (1) Do the BITE test of the potable-water ice-protection system AMM 30-73-00-740-001.
(2) If the green III/IV LED of CONTROL UNIT 3DW does not come on:
(a) Do a check of the related microfuses.
(b) If the microfuses are OK:
1 Replace CONTROL UNIT, POTABLE WATERICE PROTECTION- [3DW] AMM 30-73-34-000-001 and AMM 30-73-34-400-001.
(c) If the fault continues:
1 Remove the insulation from around the SENSOR 40DU, HEATER 42DU and HEATER 41DU.
2 Apply SPRAY - COOLING to the SENSOR 40DU for at least 10 s.
3 Stop for approximately 120 s.
4 Do a check of the temperature of HEATER 42DU and HEATER 41DU.
5 If a heater stays cold:
a Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
- Resistance values of the temperature sensor:
| TEMPERATURE | RESISTANCE VALUE IN OHM |
|---|---|
| -10deg C (14deg F) | 1784+-9 |
| 0deg C (32deg F) | 1854+-8 |
| +10deg C (50deg F) | 1926+-6 |
| +20deg C (68deg F) | 2000+-5 |
| +30deg C (86deg F) | 2076+-5 |
| +40deg C (104deg F) | 2153+-6 |
- Resistance values of the heater:
| PART NUMBER | RESISTANCE VALUE IN OHM |
|---|---|
| 4-60000H800-00 | 57+-3 |
| 4-60000H840-00 | 57+-3 |
| 4-60000H880-00 | 118+-5 |
| 4-60000H882-00 | 118+-5 |
| 4-60000H883-00 | 118+-5 |
(d) If the fault continues:
1 If HEATER 42DU and HEATER 41DU stay cold:
Replace SENSOR,TEMPERATURE- [40DU] AMM 30-71-17-000-001 and AMM 30-71-17-400-001.
2 If HEATER 41DU stays cold:
Replace
3 If HEATER 42DU stays cold:
Replace HEATER-TAPE, [42DU] AMM 30-71-53-000-001 and AMM 30-71-53-400-001.
(e) If one microfuse is not OK:
1 Do a check for a short circuit ASM 307101.
2 Replace the microfuse .
D. If the green I/II LED of CONTROL UNIT 140DU does not come on:
(1) Do a check of the related microfuses.
(2) If the microfuses are OK:
(a) Replace the CONTROL UNIT, WASTE WATER ICE PROTECTION- [140DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(3) If the fault continues:
(a) Do a check for the subsequent signals:
1 Remove the insulation from around SENSOR 141DU, the HEATERS 142DU, 146DU and 147DU.
2 Apply SPRAY - COOLING to the SENSOR 141DU for at least 10 s.
3 Stop for approximately 120 s.
4 Do a check of the temperature of the HEATERS 142DU, 146DU and 147DU.
5 If one of the HEATERS stays cold:
a Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
(c) If the fault continues:
1 If the HEATERS 142DU, 146DU and 147DU stay cold:
Replace SENSOR,TEMPERATURE- [141DU] AMM 30-71-17-000-001 and AMM 30-71-17-400-001.
2 If HEATER 142DU stays cold:
ReplaceHEATER ELEMENT-WASTE WATER DE ICING (142DU) AMM 30-71-53-000-003 and AMM 30-71-53-400-003.
3 If HEATER 146DU stays cold:
ReplaceHEATER ELEMENT-WASTE WATER DE ICING (146DU) AMM 30-71-53-000-003 and AMM 30-71-53-400-003.
4 If HEATER 147DU stays cold:
ReplaceHEATER ELEMENT-WASTE WATER DE ICING (147DU) AMM 30-71-53-000-003 and AMM 30-71-53-400-003.
(d) If there is no 115 VAC:
1 Do a check and repair the wiring between:
CONTROL UNIT 140DU connector A/14 and CB 8DU.
(e) If there is no 28 VDC:
1 Do a check and repair the wiring between:
CONTROL UNIT 140DU connector A/16 and CB 9DU.
(f) If there is no GND:
1 Do a check and repair the related wiring between:
(a) Do a check for a short circuit ASM 307101.
(b) Replace the microfuse.
Subtask 30-71-00-810-057-D ** ON A/C NOT FOR ALL (1) Do a check of the related microfuses.
(2) If the microfuses are OK:
(a) Replace the CONTROL UNIT, WASTE WATER ICE PROTECTION- [140DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(3) If the fault continues:
(a) Do a check for the subsequent signals:
- 115 VAC at CONTROL UNIT 140DU connector A/14
- 28 VDC at CONTROL UNIT 140DU connector A/16
- GND at CONTROL UNIT 140DU connector A/12
- GND at CONTROL UNIT 140DU connector A/15 ASM 307101.
1 Remove the insulation from around SENSOR 141DU, the HEATERS 142DU, 146DU and 147DU.
2 Apply SPRAY - COOLING to the SENSOR 141DU for at least 10 s.
3 Stop for approximately 120 s.
4 Do a check of the temperature of the HEATERS 142DU, 146DU and 147DU.
5 If one of the HEATERS stays cold:
a Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
- Resistance values of the temperature sensor:
| TEMPERATURE | RESISTANCE VALUE IN OHM |
|---|---|
| -10deg C (14deg F) | 1784+-9 |
| 0deg C (32deg F) | 1854+-8 |
| +10deg C (50deg F) | 1926+-6 |
| +20deg C (68deg F) | 2000+-5 |
| +30deg C (86deg F) | 2076+-5 |
| +40deg C (104deg F) | 2153+-6 |
- Resistance values of the heater:
| PART NUMBER | RESISTANCE VALUE IN OHM |
|---|---|
| 4-60000H800-00 | 57+-3 |
| 4-60000H840-00 | 57+-3 |
| 4-60000H880-00 | 118+-5 |
| 4-60000H882-00 | 118+-5 |
| 4-60000H883-00 | 118+-5 |
(c) If the fault continues:
1 If the HEATERS 142DU, 146DU and 147DU stay cold:
Replace SENSOR,TEMPERATURE- [141DU] AMM 30-71-17-000-001 and AMM 30-71-17-400-001.
2 If HEATER 142DU stays cold:
Replace
3 If HEATER 146DU stays cold:
Replace
4 If HEATER 147DU stays cold:
Replace
(d) If there is no 115 VAC:
1 Do a check and repair the wiring between:
CONTROL UNIT 140DU connector A/14 and CB 8DU.
(e) If there is no 28 VDC:
1 Do a check and repair the wiring between:
CONTROL UNIT 140DU connector A/16 and CB 9DU.
(f) If there is no GND:
1 Do a check and repair the related wiring between:
- CONTROL UNIT 140DU connector A/12 and GND
- CONTROL UNIT 140DU connector A/15 and GND ASM 307101.
(a) Do a check for a short circuit ASM 307101.
(b) Replace the microfuse.
D. If the green UNIT LED and the green HTR LED of CONTROL UNIT 5DU come on:
(1) Do the BITE test of the potable-water ice-protection system AMM 30-73-00-740-001.
(2) If the green III/IV LED of CONTROL UNIT 3DW does not come on:
(a) Do a check of the related microfuses.
(b) If the microfuses are OK:
1 Replace CONTROL UNIT, POTABLE WATERICE PROTECTION- [3DW] AMM 30-73-34-000-001 and AMM 30-73-34-400-001.
(c) If the fault continues:
1 Remove the insulation from around the SENSOR 141DU, the HEATER 48DU,HEATER 49DU and HEATER 142DU.
2 Apply SPRAY - COOLING to the SENSOR 141DU for at least 10 s.
3 Stop for approximately 120 s.
4 Do a check of the temperature of HEATER 48DU, HEATER 49DU and HEATER 142DU.
5 If one of the HEATERS stays cold:
a Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
(d) If the fault continues:
1 If HEATER 48DU, HEATER 49DU and HEATER 142DU stay cold:
Subtask 30-71-00-710-059-A (1) Do the BITE test of the potable-water ice-protection system AMM 30-73-00-740-001.
(2) If the green III/IV LED of CONTROL UNIT 3DW does not come on:
(a) Do a check of the related microfuses.
(b) If the microfuses are OK:
1 Replace CONTROL UNIT, POTABLE WATERICE PROTECTION- [3DW] AMM 30-73-34-000-001 and AMM 30-73-34-400-001.
(c) If the fault continues:
1 Remove the insulation from around the SENSOR 141DU, the HEATER 48DU,HEATER 49DU and HEATER 142DU.
2 Apply SPRAY - COOLING to the SENSOR 141DU for at least 10 s.
3 Stop for approximately 120 s.
4 Do a check of the temperature of HEATER 48DU, HEATER 49DU and HEATER 142DU.
5 If one of the HEATERS stays cold:
a Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
- Resistance values of the temperature sensor:
| TEMPERATURE | RESISTANCE VALUE IN OHM |
|---|---|
| -10deg C (14deg F) | 1784+-9 |
| 0deg C (32deg F) | 1854+-8 |
| +10deg C (50deg F) | 1926+-6 |
| +20deg C (68deg F) | 2000+-5 |
| +30deg C (86deg F) | 2076+-5 |
| +40deg C (104deg F) | 2153+-6 |
- Resistance values of the heater:
| PART NUMBER | RESISTANCE VALUE IN OHM |
|---|---|
| 4-60000H800-00 | 57+-3 |
| 4-60000H840-00 | 57+-3 |
| 4-60000H880-00 | 118+-5 |
| 4-60000H882-00 | 118+-5 |
| 4-60000H883-00 | 118+-5 |
(d) If the fault continues:
1 If HEATER 48DU, HEATER 49DU and HEATER 142DU stay cold:
- Replace
[40DU] AMM 30-71-17-000-001 and AMM 30-71-17-400-001.
- Replace HEATER [48DU] AMM 30-71-53-000-001 and AMM 30-71-53-400-001.
- Replace HEATER [49DU] AMM 30-71-53-000-001 and AMM 30-71-53-400-001.
- Replace
HEATER ELEMENT-WASTE WATER DE ICING (142DU) AMM 30-71-53-000-001 and AMM 30-71-53-400-001.
- Do a check for a short circuit ASM 307101.
- Replace the microfuse .
E. Do the test as given in Para. 3.A.
5. Close-upSubtask 30-71-00-860-054-A
A. Put the aircraft back to its initial configuration.