DOC AIRBUS | TSM A320FLow Power or Slow/Hung Acceleration on Engine 1
1. Possible Causes
· FMU (400KC)
· PUMP-HP/LP-FUEL
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
75-00-00-810-804-B Hung Start/Hot Start/Stall - Effect of HPC Bleed System on Engine Operation
Ref. AMM 24-41-00-861-002 Energize the Aircraft Electrical Circuits from the External Power
Ref. AMM 24-41-00-862-002 De-energize the Aircraft Electrical Circuits Supplied from the External
Power
Ref. AMM 31-60-00-860-002 EIS Stop Procedure
Ref. AMM 71-00-00-700-011 Test No.13 : Pretested Replacement Engine Test
Ref. AMM 71-00-00-710-018 Discontinued Start, Restart and Shutdown Procedures
Ref. AMM 71-00-00-710-043 Normal Engine Automatic Start Procedure
Ref. AMM 71-00-00-710-047 Normal Engine Manual Start Procedure
Ref. AMM 71-13-00-010-010 Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 71-13-00-410-010 Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 72-00-00-200-016 Inspection of the HP Compressor
Ref. AMM 72-31-11-100-010 Cleaning of the LP Compressor Blades
Ref. AMM 73-12-41-000-010 Removal of the Low Pressure (LP)/High Pressure (HP) Fuel Pump
Ref. AMM 73-12-41-400-010 Installation of the Low Pressure (LP)/High Pressure (HP) Fuel Pump
Ref. AMM 73-12-42-000-010 Removal of the Fuel Filter Element
Ref. AMM 73-12-42-400-010 Installation of the Fuel Filter Element
Ref. AMM 73-22-51-700-801 Functional Test of the P4.9 (P5) Sensor System
Ref. AMM 73-22-52-000-010 Removal of the Fuel Metering Unit (FMU)
REFERENCE DESIGNATION
Ref. AMM 73-22-52-400-010 Installation of the Fuel Metering Unit (FMU)
Ref. AMM 75-32-42-200-010 Inspection of the VSV Mechanism
Ref. AMM 75-32-52-700-011 Functional Test of the HPC Stage 7 Bleed Valve with Test Set
IAE2R19437
Ref. AMM 75-32-54-700-011 Functional Test of the HPC Stage 10 Bleed Valve with Test Set
IAE2R19437
3. Fault Confirmation
Subtask 73-00-00-860-203-A
A. Job Set-up
(1) Energize the aircraft electrical circuits
Ref. AMM 24-41-00-861-002 .
(2) On the panel 50VU, release the ENG FADEC GND PWR pushbutton switch.
Subtask 73-00-00-710-208-A
B. Test
(1) On the panel 50VU, push the ENG FADEC GND PWR 1 pushbutton switch and release it again.
NOTE: This action resets the FADEC memory.
(2) Adjust the brightness of the MCDU screen.
(3) Push the INIT mode key. The INIT page comes into view.
(4) Enter a new flight number.
(5) Start the engine 1 with the normal engine automatic start procedure Ref. AMM 71-00-00-710-043 or
the normal engine manual start procedure Ref. AMM 71-00-00-710-047 .
NOTE: Operation of the engine for at least 3 minutes erases the LAST LEG REPORT related to the
last flight and the new fault is recorded in the EEC LAST LEG REPORT.
(6) Do an acceleration and deceleration check Ref. AMM 71-00-00-700-011 .
(7) Do a shutdown of the engine 1 with the discontinued start, restart and shutdown procedure Ref.
AMM 71-00-00-710-018 .
(8) Read the LAST LEG REPORT of the FADEC (1A and 1B) menu on the MCDU (Ref. 70-00-00 Page
Block 301 Task Supporting Data).
(a) Make a record of the maintenance message.
(b) Make a record of the channel, FADEC 1A or FADEC 1B, that found the fault.
(9) Fully decrease the brightness of the MCDU screen (display off).
4. Fault Isolation
Subtask 73-00-00-810-135-B
A. If the fault symptom is identified by either of the crew observations:
(1) ENG 1 - Low Power
(2) ENG 1 - Slow/hung acceleration,
or the acceleration/deceleration times given in Ref. AMM 71-00-00-700-011 were not achieved:
(3) Open the fan cowls 437AL and 438AR Ref. AMM 71-13-00-010-010 .
(4) Do a check of the P2T2 sensor for contamination or obstruction. If contamination or obstruction is
found, clean the probe.
(5) Examine the P4.9 (P5) pressure probe for leaks, damage and water contamination Ref.
AMM 73-22-51-700-801 .
(6) If the fault continues:
(a) Replace the FILTER ELEMENT-FUEL (2000EM) Ref. AMM 73-12-42-000-010 and Ref.
AMM 73-12-42-400-010 . If you find metal debris on the filter, do a check for contamination on
engine 1.
(7) If the fault continues:
(a) Do the inspection of the VSV mechanism Ref. AMM 75-32-42-200-010 .
(8) If the fault continues:
(a) Do a functional test of the HPC stage 7 bleed valve Ref. AMM 75-32-52-700-011 and of the
HPC stage 10 bleed valve Ref. AMM 75-32-54-700-011 .
NOTE: For additional information on bleed valve effects on engine operation, refer to (Ref.
75-00-00 Page Block 301 Task Supporting Data) and (Ref. TSM 75-00-00-810-804) .
(9) If the fault continues:
(a) Do an inspection of the HP compressor Ref. AMM 72-00-00-200-016 .
(10) If the fault continues:
(a) Do a visual inspection of the air offtakes for signs of leakage on engine 1.
(11) If the fault continues:
(a) Replace the FMU (400KC) Ref. AMM 73-22-52-000-010 and Ref. AMM 73-22-52-400-010 .
(12) If the fault continues:
(a) Replace the PUMP-HP/LP-FUEL Ref. AMM 73-12-41-000-010 and Ref.
AMM 73-12-41-400-010 .
(13) If the fault continues:
(a) Do a cleaning of the LP compressor Ref. AMM 72-31-11-100-010 .
5. Close-up
Subtask 73-00-00-860-204-A
A. Put the aircraft back to its initial configuration.
(1) On the MCDU control panel, set the UPPER and LOWER DISPLAY potentiometers to OFF Ref.
AMM 31-60-00-860-002 .
(2) On the panel 50VU, push the ENG FADEC GND PWR 1 pushbutton switch.
(3) De-energize the aircraft electrical circuits Ref. AMM 24-41-00-862-002 .
(4) Make sure that the fan cowls 437AL and 438AR are closed Ref. AMM 71-13-00-410-010 . [Rev.6 from Feb 2017] 2026.04.04 04:36:07 UTC