DOC AIRBUS | TSM A320FTroubleshoot the Engine after a Thrust Power (N1) Fluctuates event
TASK 71-00-00-810-878-A
Troubleshoot the Engine after a Thrust Power (N1) Fluctuates event
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 71-00-00-710-138-A ** ON A/C NOT FOR ALL
Subtask 71-00-00-860-092-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:35:07 UTC
Troubleshoot the Engine after a Thrust Power (N1) Fluctuates event
1. Possible Causes
- INTEGRATED FUEL PUMP AND CONTROL [4360KS]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 71-00-00-810-854-A | Troubleshoot the Engine after a Surge - Forward Thrust event |
| TSM TASK 73-11-00-810-808-A | Integrated Fuel Pump and Control/FMV-Track Check Channel A |
| TSM TASK 73-11-00-810-813-A | Integrated Fuel Pump and Control/FMV-Track Check Channel B |
| TSM TASK 73-21-00-810-869-A | EEC Internal Failure GO IF |
| TSM TASK 73-21-00-810-870-A | EEC Internal Failure Level B |
| TSM TASK 73-21-00-810-878-A | EEC Internal Failure Level A NO GO |
| TSM TASK 76-11-00-810-824-A | Autothrust Instinctive Disconnect Hardwired Discrete Signal Failure Channel A |
| TSM TASK 76-11-00-810-825-A | TRA Signal Failure Channel A |
| TSM TASK 76-11-00-810-826-A | TRA Signal Failure Channel B |
| TSM TASK 76-11-00-810-827-A | Autothrust Instinctive Disconnect Hardwired Discrete Signal Failure Channel B |
| TSM TASK 77-11-00-810-808-A | N1 Sensor Electrical Failure Channel B |
| TSM TASK 77-11-00-810-809-A | N1 Sensor Electrical Failure Channel A |
| AMM 36-11-00-710-802 | Operational Test of the Bleed Air System |
| AMM 71-00-00-710-805 | Test No. 4 - Power Acceleration/Deceleration Test |
| AMM 72-00-00-210-812 | General visual Inspection (GVI) of the Engine Exhaust Area |
| AMM 72-00-00-210-813 | General Visual Inspection (GVI) of the Engine Inlet Area |
| AMM 72-35-00-290-801 | Borescope Inspection of the High Pressure Compressor (HPC) Assembly |
| AMM 72-41-00-290-802 | Borescope Inspection of the Combustion Chamber and HPT Nozzle Guide Vanes |
| AMM 72-51-00-290-802 | Borescope Inspection of the High Pressure Turbine (HPT) |
| AMM 72-53-00-200-801 | Borescope Inspection of the Low Pressure Turbine (LPT) Assembly |
| AMM 73-11-01-000-801 | Removal of the Integrated Fuel Pump and Control (IFPC) |
| AMM 73-11-01-400-801 | Installation of the Integrated Fuel Pump and Control (IFPC) |
| AMM 73-21-00-200-806 | Electronic Engine Control (EEC) Sensing System Check |
| AMM 73-21-00-710-806 | Test No.7 - EEC Operation Test (Self Test) |
| AMM 76-11-00-710-804 | Operational Test of the Throttle Control Unit |
| AMM 77-00-00-00- |
Subtask 71-00-00-710-138-A ** ON A/C NOT FOR ALL
A. Investigate the Engine after a Thrust Power (N1) Fluctuates event
(1) Using the Multipurpose Control and Display Unit (MCDU) test the FADEC system for any recorded faults AMM 73-21-00-710-806.
(2) Any EEC monitored faults are transmitted to the aircraft Centralized Fault Display Interface Unit (CFDIU). The MCDU allows interactive dialog with the EEC. Use the MCDU to review the previous flight leg fault information, scheduled maintenance fault information and ground fault information. If there are any faults reported troubleshoot them first.
(3) If the only affected parameter is N1 it is an indication system fault. Refer to AMM 77-00-00-00- for aircraft indication information.
4. Fault Isolation(1) Using the Multipurpose Control and Display Unit (MCDU) test the FADEC system for any recorded faults AMM 73-21-00-710-806.
(2) Any EEC monitored faults are transmitted to the aircraft Centralized Fault Display Interface Unit (CFDIU). The MCDU allows interactive dialog with the EEC. Use the MCDU to review the previous flight leg fault information, scheduled maintenance fault information and ground fault information. If there are any faults reported troubleshoot them first.
(3) If the only affected parameter is N1 it is an indication system fault. Refer to AMM 77-00-00-00- for aircraft indication information.
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.
Subtask 71-00-00-810-145-A ** ON A/C NOT FOR ALL A. Do the steps that follow:
(1) If the crew alert warning messages related to the engine stall appear, refer to troubleshoot the engine after a surge - forward thrust event (Ref. TSM TASK 71-00-00-810-854).
(2) If the maintenance messages related to the Throttle Resolver Angle (TRA) signal failure on channel A appear with the ECAM warning for engine one Throttle Lever Angle (TLA) fault or engine throttle lever fault, refer to TRA signal failure (Ref. TSM TASK 76-11-00-810-825).
(3) If the maintenance messages related to the TRA signal failure on channel B appear with the ECAM warning for engine one TLA fault or engine throttle lever fault, refer to TRA signal failure (Ref. TSM TASK 76-11-00-810-826).
(4) If the maintenance messages related to the A/THR instinctive disconnect on channel A appear with the ECAM warning for engine FADEC status, refer to autothrust instinctive disconnect hardwired discrete signal failure (Ref. TSM TASK 76-11-00-810-824).
(5) If the maintenance messages related to the A/THR instinctive disconnect on channel B appear with the ECAM warning for engine FADEC status, refer to autothrust instinctive disconnect hardwired discrete signal failure (Ref. TSM TASK 76-11-00-810-827).
(6) If the maintenance messages related to the Fuel Metering Valve (FMV) track check on channel A appear with the ECAM warning for engine FADEC status maintenance and/or the ECAM warning for engine fuel control fault and engine fuel valve fault, refer to integrated fuel pump and control/FMV-track check channel A (Ref. TSM TASK 73-11-00-810-808).
(7) If the maintenance messages related to the FMV track check on channel B appear with the ECAM warning for engine FADEC status maintenance and/or the ECAM warning for engine fuel control fault and engine fuel valve fault, refer to integrated fuel pump and control/FMV-track check channel B (Ref. TSM TASK 73-11-00-810-813).
(8) If the maintenance messages related to the EEC internal failure short time dispatch appear with the ECAM warning for engine minor fault, refer to EEC internal failure level B (Ref. TSM TASK 73-21-00-810-870).
(9) If the maintenance messages related to the EEC internal failure GO IF appear with the ECAM warning for GO IF MMEL, refer to EEC internal failure GO IF (Ref. TSM TASK 73-21-00-810-869).
(10) If the maintenance messages related to the EEC internal failure NO GO appear with the ECAM warning for NO GO and/or engine FADEC system fault refer to EEC internal failure level A NO GO (Ref. TSM TASK 73-21-00-810-878).
(11) If the maintenance messages related to the N1 speed sensor failure on channel A appear with the ECAM warning for engine FADEC system fault or engine sensor fault and amber crosses on N1, refer to N1 sensor electrical failure (Ref. TSM TASK 77-11-00-810-809).
(12) If the maintenance messages related to the N1 speed sensor failure on channel B appear with the ECAM warning for engine FADEC system fault or engine sensor fault and amber crosses on N1, refer to N1 sensor electrical failure (Ref. TSM TASK 77-11-00-810-808).
(13) If there are no EEC monitored faults or messages recorded, make sure that the Throttle Control Unit (TCU) input to the EEC is functioning correctly AMM 76-11-00-710-804.
(14) If you do not find any problems, check the burner pressure sensing lines AMM 73-21-00-200-806.
(15) If you do not find any problems, make sure that the aircraft pneumatic system is operating properly AMM 36-11-00-710-802.
(16) If you do not find any problems:
(a) Replace INTEGRATED FUEL PUMP AND CONTROL [4360KS] AMM 73-11-01-000-801 and AMM 73-11-01-400-801.
(17) If you do not find any problems, do an engine run (if you have not done one) and a power assurance test AMM 71-00-00-710-805.
(18) If the fault continues, the engine gaspath is suspect. Inspect the engine gaspath as follows below.
(19) Visually inspect the engine inlet area AMM 72-00-00-210-813.
(20) If damage is found beyond acceptable limits, remove the engine from service.
(21) If you do not find any problems, visually inspect the engine exhaust area AMM 72-00-00-210-812.
(22) If you do not find any problems, borescope inspect the High Pressure Compressor (HPC) AMM 72-35-00-290-801.
(23) If you do not find any problems, borescope inspect the High Pressure Turbine (HPT) AMM 72-51-00-290-802.
(24) If you do not find any problems, borescope inspect the combustion chamber area AMM 72-41-00-290-802.
(25) If you do not find any problems, borescope inspect the Low Pressure Turbine (LPT) AMM 72-53-00-200-801.
5. Close-up(1) If the crew alert warning messages related to the engine stall appear, refer to troubleshoot the engine after a surge - forward thrust event (Ref. TSM TASK 71-00-00-810-854).
(2) If the maintenance messages related to the Throttle Resolver Angle (TRA) signal failure on channel A appear with the ECAM warning for engine one Throttle Lever Angle (TLA) fault or engine throttle lever fault, refer to TRA signal failure (Ref. TSM TASK 76-11-00-810-825).
(3) If the maintenance messages related to the TRA signal failure on channel B appear with the ECAM warning for engine one TLA fault or engine throttle lever fault, refer to TRA signal failure (Ref. TSM TASK 76-11-00-810-826).
(4) If the maintenance messages related to the A/THR instinctive disconnect on channel A appear with the ECAM warning for engine FADEC status, refer to autothrust instinctive disconnect hardwired discrete signal failure (Ref. TSM TASK 76-11-00-810-824).
(5) If the maintenance messages related to the A/THR instinctive disconnect on channel B appear with the ECAM warning for engine FADEC status, refer to autothrust instinctive disconnect hardwired discrete signal failure (Ref. TSM TASK 76-11-00-810-827).
(6) If the maintenance messages related to the Fuel Metering Valve (FMV) track check on channel A appear with the ECAM warning for engine FADEC status maintenance and/or the ECAM warning for engine fuel control fault and engine fuel valve fault, refer to integrated fuel pump and control/FMV-track check channel A (Ref. TSM TASK 73-11-00-810-808).
(7) If the maintenance messages related to the FMV track check on channel B appear with the ECAM warning for engine FADEC status maintenance and/or the ECAM warning for engine fuel control fault and engine fuel valve fault, refer to integrated fuel pump and control/FMV-track check channel B (Ref. TSM TASK 73-11-00-810-813).
(8) If the maintenance messages related to the EEC internal failure short time dispatch appear with the ECAM warning for engine minor fault, refer to EEC internal failure level B (Ref. TSM TASK 73-21-00-810-870).
(9) If the maintenance messages related to the EEC internal failure GO IF appear with the ECAM warning for GO IF MMEL, refer to EEC internal failure GO IF (Ref. TSM TASK 73-21-00-810-869).
(10) If the maintenance messages related to the EEC internal failure NO GO appear with the ECAM warning for NO GO and/or engine FADEC system fault refer to EEC internal failure level A NO GO (Ref. TSM TASK 73-21-00-810-878).
(11) If the maintenance messages related to the N1 speed sensor failure on channel A appear with the ECAM warning for engine FADEC system fault or engine sensor fault and amber crosses on N1, refer to N1 sensor electrical failure (Ref. TSM TASK 77-11-00-810-809).
(12) If the maintenance messages related to the N1 speed sensor failure on channel B appear with the ECAM warning for engine FADEC system fault or engine sensor fault and amber crosses on N1, refer to N1 sensor electrical failure (Ref. TSM TASK 77-11-00-810-808).
(13) If there are no EEC monitored faults or messages recorded, make sure that the Throttle Control Unit (TCU) input to the EEC is functioning correctly AMM 76-11-00-710-804.
(14) If you do not find any problems, check the burner pressure sensing lines AMM 73-21-00-200-806.
(15) If you do not find any problems, make sure that the aircraft pneumatic system is operating properly AMM 36-11-00-710-802.
(16) If you do not find any problems:
(a) Replace INTEGRATED FUEL PUMP AND CONTROL [4360KS] AMM 73-11-01-000-801 and AMM 73-11-01-400-801.
(17) If you do not find any problems, do an engine run (if you have not done one) and a power assurance test AMM 71-00-00-710-805.
(18) If the fault continues, the engine gaspath is suspect. Inspect the engine gaspath as follows below.
(19) Visually inspect the engine inlet area AMM 72-00-00-210-813.
(20) If damage is found beyond acceptable limits, remove the engine from service.
(21) If you do not find any problems, visually inspect the engine exhaust area AMM 72-00-00-210-812.
(22) If you do not find any problems, borescope inspect the High Pressure Compressor (HPC) AMM 72-35-00-290-801.
(23) If you do not find any problems, borescope inspect the High Pressure Turbine (HPT) AMM 72-51-00-290-802.
(24) If you do not find any problems, borescope inspect the combustion chamber area AMM 72-41-00-290-802.
(25) If you do not find any problems, borescope inspect the Low Pressure Turbine (LPT) AMM 72-53-00-200-801.
Subtask 71-00-00-860-092-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.
(1) Make sure that the work area is clean and clear of tools and other items.