W DOC AIRBUS | TSM A320F

NAI System Failed Closed with the NAI Pushbutton Switch Pushed

TASK 30-21-00-810-813-A
NAI System Failed Closed with the NAI Pushbutton Switch Pushed

1. Possible Causes
  • damaged tubes
  • NACELLE ANTI-ICE UPPER VALVE AND ATTACHMENT HARDWARE [4010DN]
  • NAI SOLENOID BLOCK [4190KS]
  • NACELLE ANTI-ICE LOWER VALVE AND ATTACHMENT HARDWARE [4011DN]
  • W03 HARNESS [4087KS]
  • W04 HARNESS [4088KS]
  • PRESS XDCR-ENGINE AIR INTAKE ANTI ICE, 2 [4003DN]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 71-00-00-810-835-A
Component and Harness Intermittent Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults
AMM 30-21-00-040-803
Deactivation of the NAI Upper Valve with the Thrust Reverser Door Open
AMM 30-21-00-040-804
Deactivation of the NAI Lower Valve with the Thrust Reverser Door Open
AMM 30-21-00-440-803
Reactivation of the NAI Upper Valve with the Thrust Reverser Door Open
AMM 30-21-00-440-804
Reactivation of the NAI Lower Valve with the Thrust Reverser Door Open
AMM 30-21-00-710-002
Operational Test of the Engine Air Intake Ice Protection (with the Engines in operation)
AMM 30-21-12-000-801
Removal of the Nacelle Anti-Ice Sense-Tubes
AMM 30-21-12-400-801
Installation of the Nacelle Anti-Ice Sense-Tubes
AMM 30-21-21-000-801
Removal of the Nacelle Anti-Ice Solenoid-Manifold
AMM 30-21-21-400-801
Installation of the Nacelle Anti-Ice Solenoid-Manifold
AMM 30-21-23-000-801
Removal of the Nacelle Anti-Ice Fan-Pressure-Transducer
AMM 30-21-23-400-801
Installation of the Nacelle Anti-Ice Fan-Pressure-Transducer
AMM 30-21-51-000-802
Removal of the Upper Anti-Ice Valve
AMM 30-21-51-000-803
Removal of the Lower Anti-Ice Valve
AMM 30-21-51-400-802
Installation of the Upper Anti-Ice Valve
AMM 30-21-51-400-803
Installation of the Lower Anti-Ice Valve
AMM 31-32-00-860-012
Procedure to Get Access to the SYSTEM REPORT/TEST/ENG Page
AWM 715134
AMM 73-21-63-000-802
Removal of the Electronic Engine Control (EEC) Wiring Harness (W03)
AMM 73-21-63-400-802
Installation of the Electronic Engine Control (EEC) Wiring Harness (W03)
AMM 73-21-64-000-802
Removal of the Electronic Engine Control (EEC) Wiring Harness (W04)
AMM 73-21-64-400-802
Installation of the Electronic Engine Control (EEC) Wiring Harness (W04)
AMM 78-36-00-010-802
Opening of the Thrust Reverser Cowl-Doors
AMM 78-36-00-410-802
Closing of the Thrust Reverser Cowl-Doors
3. Fault Confirmation
Subtask 30-21-00-730-050-A ** ON A/C NOT FOR ALL
A. Test
   (1) Do the operational test of the engine air intake ice protection AMM 30-21-00-710-002.
   (2) On the MCDU screen, get access to the SYSTEM REPORT/TEST/ENG menu page AMM 31-32-00-860-012.
     (a) On the SYSTEM REPORT/TEST/ENG menu page, push the line key adjacent to the FADEC 1(2) A(B) indication.
The EEC 1(2) CHAN A(B) page come into view.
     (b) Push the line key adjacent to the GND SCANNING indication, the GROUND SCANNING menu page comes into view.
       1 If there is the maintenance message, go to the Para. Fault Isolation.
       2 If the maintenance message does not come into view again, do the component and harness intermittent for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-835).
         a If you find no fault, send the engine back to service and monitor the engine to make sure that the maintenance message does not come into view again.
4. Fault Isolation
WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
CAUTION: MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.
Subtask 30-21-00-810-062-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
   (1) Open the right thrust reverser cowl-door AMM 78-36-00-010-802.
Do a check of the NAI sense tubes along its entire length for damage:
     (a) If the NAI sense tubes are damaged:
     (b) If the NAI sense tubes are not damaged:
  • Do a check for correct torque values of the nuts, sense tube nuts and fittings AMM 30-21-12-400-801.
       1 If the B nuts are loose:
  • Do a check of the condition of the B nuts and replace them if damaged.
  • Tighten the B nuts to the applicable value AMM 30-21-12-400-801.
  • Do the deactivation of the upstream NAI valve (open locked position) AMM 30-21-00-040-803.
  • Do the test given in Para. 3.
       2 If the maintenance message does not come into view again:
       3 If the maintenance message comes into view again:
  • Do the deactivation of the downstream NAI valve (open locked position) AMM 30-21-00-040-804.
  • Do the test given in Para. 3.
         a If the maintenance message does not come into view again,
         b If the maintenance message comes into view again,
  • Do the reactivation of the downstream NAI valve AMM 30-21-00-440-804.
  • Do the reactivation of the upstream NAI valve AMM 30-21-00-440-803.
  • Make sure that the electrical connector P59 of the harness W03 is correctly engaged in receptacle J59 of the NAI solenoids block.
  • If it is not correctly engaged, engage it:
  • Do the test given in Para. 3.
         c If the fault continues, or if the electrical connector P59 of the WO3 harness is correctly engaged in receptacle J59 of the NAI solenoids block:
  • Disconnect electrical connector P59 of the NAI lower SOV of the NAI solenoids block.
  • Examine electrical receptacle J59 of the NAI lower SOV for bent pins, contamination, corrosion or visual signs of damage.
         d If you find damage on electrical receptacle J59:
         e If you find no damage on receptacle J59:
  • Examine electrical connector P59 of the W03 harness for bent pins, contamination, corrosion or visual signs of damage.
         f If you find damage on electrical connector P59:
         g If you find no damage on electrical connector P59:
  • On receptacle J59 of the NAI lower SOV, do a resistance check AWM 715134 between pin J59/1 and pin J59/2 of the NAI solenoids block.
         h If the resistance is not between 2 ohm and 2.6 kohm:
         i If the resistance is between 2 ohm and 2.6 kohm:
  • Make sure that the electrical connector P58 of the harness W03 is correctly engaged in receptacle J58 of the NAI solenoids block.
  • If it is not correctly engaged, engage it:
  • Do the test given in Para. 3.
  • If the fault continues, or if the electrical connector P58 of the harness W03 is correctly engaged in receptacle J58 of the NAI solenoids block:
  • Disconnect electrical connector P58 of the NAI upper SOV of the NAI solenoids block,
  • Examine electrical receptacle J58 of the NAI upper SOV for bent pins, contamination, corrosion or visual signs of damage.
         j If you find damage on electrical receptacle J58:
         k If you find no damage on receptacle J58:
  • Examine electrical connector P58 of the W04 harness for bent pins, contamination, corrosion or visual signs of damage.
         l If you find damage on electrical connector P58:
         m If you find no damage on electrical connector P58:
  • On receptacle J58 of the NAI upper SOV, do a resistance check AWM 715134 between pin J58/1 and pin J58/2 of the NAI solenoids block.
         n If the resistance is not between 2 ohm and 2.6 kohm:
         o If the resistance is between 2 ohm and 2.6 kohm:
  • Disconnect electrical connector P17 from the NAI fan pressure transducer.
  • Examine electrical receptacle J17 of the NAI fan pressure transducer for bent pin, contamination, corrosion or visual signs of damage.
         p If you find damage on electrical receptacle J17:
         q If you find no damage on electrical receptacle J17, do a resistance check AWM 715134 between:
  • Pin J17/3 of the NAI fan pressure transducer and P17/12 the NAI fan pressure transducer
  • Pin J17/4 of the NAI fan pressure transducer and P17/11 the NAI fan pressure transducer
  • Pin J17/6 of the NAI fan pressure transducer and P17/7 the NAI fan pressure transducer
  • Pin J17/8 of the NAI fan pressure transducer and P17/9 the NAI fan pressure transducer.
         r If the resistance is more than 12.5 kohm:
5. Close-up
Subtask 30-21-00-942-054-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) Make sure that the work area is clean and clear of tools and other items.
     (a) Close the right thrust-reverser cowl-door AMM 78-36-00-410-802.
[Rev.8 from Aug 2018] 2026.04.04 04:29:32 UTC
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