W DOC AIRBUS | TSM A320F

Core Vibrations Higher than or Equal to 4.2 Units (1.68 Ips), and Less than 5.4 Units (2.16 Ips) on Engine 1 or 2

TASK 77-00-00-810-865-A
Core Vibrations Higher than or Equal to 4.2 Units (1.68 Ips), and Less than 5.4 Units (2.16 Ips) on Engine 1 or 2

1. Possible Causes
  • wiring, connectors and receptacles
  • SENSOR-NO. 1 BRG VIB [4002EV]
  • TRF vibration sensor
  • Engine
  • SENSOR-TRF VIB [4003EV]
  • EVMU [2EV]
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
AR
BRUSH - BRISTLED
No specific
1
MEGOHMMETER 100 MOHMS
No specific
AR
PLIERS - NOSE, SOFT, LONG
 B. Consumable Materials
REFERENCE
DESIGNATION
(Material No.CP2011)
stoddard solvent
 C. Referenced Information
REFERENCE
DESIGNATION
AMM 71-11-00-210-001
Visual Inspection of the Air Intake Cowl
AMM 71-11-00-210-040
Visual Inspection of the Air Intake Cowl
AMM 71-50-00-210-001
Visual Inspection of the Power Plant Wire Harness
AMM 71-50-00-210-040
Visual Inspection of the Power Plant Wire Harnesses
AMM 72-31-00-290-001
Inspection of the High Pressure Compressor Rotor Assembly
AMM 72-31-00-290-002
Inspection of the High Pressure Compressor Rotor Assembly
AMM 72-52-00-290-001
Borescope Inspection of HPT Blades (from the front and the rear)
AMM 73-21-50-210-001
Visual Inspection of the Wiring Harness
AMM 73-21-50-210-002
Visual Inspection of the Wiring Harnesses
AMM 77-31-10-720-001
Electrical Test of the No. 1 Bearing Vibration Sensor
AMM 77-31-10-720-002
Electrical Test of the No. 1 Bearing Vibration Sensor
AMM 77-31-30-000-001
Removal of the Turbine Rear Frame Vibration Sensor
AMM 77-31-30-000-002
Removal of the Turbine Rear Frame Vibration Sensor
AMM 77-31-30-400-001
Installation of the Turbine Rear Frame Vibration Sensor
AMM 77-31-30-400-002
Installation of the Turbine Rear Frame Vibration Sensor
ASM 773202
AMM 77-32-34-710-040
Operational Check of EVMU through CFDS for Advisory Indication on ECAM
AMM 77-32-34-860-041
Change the configuration of the Accelerometer
AMM 77-32-34-869-041
Change the configuration of the Accelerometer
AMM 79-00-00-281-002
Check of the Electrical Master Chip Detector (EMCD) for Particles
AMM 79-00-00-281-003
Check of FWD Sump, AFT Sump, AGB, and TGB Scavenge Screens
AMM 79-21-10-210-002
Check of the Lubrication Unit Magnetic Plugs and Scavenge Screens
AMM 79-35-00-040-042
Replacement of the Main Oil Supply Filter and Check of the Electrical Chip Detector Visual Indicator (pop-out)
3. Fault Confirmation
Subtask 77-00-00-710-155-A ** ON A/C NOT FOR ALL
A. Test
   (1) Not applicable, the fault is evident.
4. Fault Isolation
Subtask 77-00-00-810-122-A ** ON A/C NOT FOR ALL
A. If momentary vibration on ECAM is between 4.2 and 5.4 units but in order of less than 1 minute and provided indication did not repeat during the flight or following flights:
  • no maintenance action is required.
NOTE: If the engine core vibration level is reported at the installation, dispatch the aircraft.
   (1) If the crew observation identifies ENG1/2 - CORE VIB higher than or equal to 4.2 units and less than 5.4 units.
NOTE: If the vibration level is associated to high speed (max. cont, climb, or take off): High pressure turbine may be the cause it is recommended to do the trouble shooting procedure in no more than 25 cycles; engine removal should be scheduled.
NOTE: If the vibration level is associated to low speed (descent, approach, taxi) : High pressure compressor may be the cause; Contact CFM to define cycles extension.
   (2) If the fault symptom is identified on the lower ECAM display unit by the crew observation ENG1/2 - CORE VIB higher than or equal to 4.2 units and less than 5.4 units for less than one minute, but intermittently repeated:
     (a) Do a check of the wiring, connectors and receptacles ASM 773202 between:
  • the No. 1 bearing vibration sensor (4002EV) and the EVMU (2EV),
  • the TRF vibration sensor (4003EV) and the EVMU (2EV).
     (b) Disconnect the harnesses from the No. 1 bearing and the TRF sensors.
       1 If damage is found:
  • repair or replace as required.
       2 If no damage is found:
     (c) Do the electrical test of the No. 1 bearing vibration sensor (4002EV) AMM 77-31-10-720-002.
       1 If the resistance values are out of the limits, replace the SENSOR-NO. 1 BRG VIB [4002EV] at the next shop maintenance opportunity.
NOTE: The No. 1 bearing vibration sensor cannot be replaced on-wing.
     (d) Do an electrical test of the TRF vibration sensor:
       1 Disconnect the aircraft harness from the vibration sensor connectors. If necessary, use PLIERS - NOSE, SOFT, LONG.
       2 Measure the insulation resistance with a MEGOHMMETER 100 MOHMS between:
. pins 1 and 2
. pins 1 and 3
. pin 2 and connector body
. pin 3 and connector body,
       3 The insulation resistance is expected to be greater than 20 megohms. If one of these measurements are less than 20 megohms, the sensor is not serviceable.
       4 If the TRF vibration sensor is not serviceable, it must be replaced AMM 77-31-30-000-001 and AMM 77-31-30-400-001.
     (e) If nothing is found:
  • do the operational test of the Engine Vibration Monitoring Unit (EVMU) through the Centralized Fault Display System (CFDS) AMM 77-32-34-710-040.
     (f) If nothing is found:
  • Dispatch the aircraft. Vibration level must be monitored closely.
NOTE: HP unbalance is the first cause of core vibration, may be not perceptible through trouble shooting actions. The presence of high N2 vibration requires to schedule the engine removal for root cause identification at shop level.
   (3) If the fault symptom is identified on the lower ECAM display unit by the crew observation ENG1/2 - CORE VIB higher than or equal to 4.2 units and less than 5.4 units for more than one minute:
  • open the cowlings AMM 71-11-00-210-040 and do a visual inspection around the engine (centerbody plug, piping and brackets fan cowl and core cowl area).
     (a) Do a check and an inspection of the accessories and QEC components. This includes the check and inspection of:
  • the accessory gear box mounts,
  • the link and brackets of the accessories to make sure they are loose or broken,
  • the cowling brackets, hinges and rigging,
  • the pneumatic system for correct condition and rigging.
       1 If the check is not correct:
  • repair or replace as required.
     (b) If nothing is found:
       1 Do a check of the wiring, connectors and receptacles ASM 773202 between:
  • the SENSOR-NO. 1 BRG VIB [4002EV] and the EVMU (2EV),
  • the SENSOR-TRF VIB [4003EV] and the EVMU [2EV] .
       2 Disconnect the harnesses from the No. 1 bearing and the TRF sensors,
         a If damage is found:
  • repair or replace as required.
         b If no damage is found:
       3 Do an electrical test of the No. 1 bearing vibration sensor and the TRF vibration sensor:
  • disconnect the aircraft harness from the vibration sensor connectors. If necessary, use PLIERS - NOSE, SOFT, LONG.
  • measure the insulation resistance with a MEGOHMMETER 100 MOHMS between:
    . pins 1 and 2
    . pins 1 and 3
    . pin 2 and connector body
    . pin 3 and connector body,
    the insulation resistance is expected to be greater than 20 megohms.
         a If one of these measurements is less than 20 megohms:
  • the sensor is not serviceable.
         b If one of the two vibration sensors is found not serviceable:
NOTE: If the TRF vibration sensor is not serviceable, it should be replaced AMM 77-31-30-000-001 and AMM 77-31-30-400-001.
NOTE: The No. 1 bearing vibration sensor cannot be replaced on-wing.
     (c) If nothing is found:
  • do the operational test of the Engine Vibration Monitoring Unit (EVMU) through the Centralized Fault Display System (CFDS) AMM 77-32-34-710-040.
     (d) Do a check of the lubrication unit magnetic plugs and screens AMM 79-21-10-210-002.
       1 If you find magnetic particles:
       2 If no magnetic particles are found:
     (e) If nothing is found:
     (f) If nothing is found:
  • dispatch the aircraft. Vibration level must be monitored closely and reported to CFMI on a regular basis.
Subtask 77-00-00-810-122-B ** ON A/C NOT FOR ALL
A. If momentary vibration on ECAM is between 4.2 and 5.4 units but in order of less than 1 minute and provided indication did not repeat during the flight or following flights:
  • no maintenance action is required.
NOTE: If the engine core vibration level is reported at the installation, dispatch the aircraft.
   (1) If the crew observation identifies ENG1/2 - CORE VIB higher than or equal to 4.2 units and less than 5.4 units.
NOTE: If the vibration level is associated to high speed (max. cont, climb, or take off): High pressure turbine may be the cause it is recommended to do the trouble shooting procedure in no more than 25 cycles; engine removal should be scheduled.
NOTE: If the vibration level is associated to low speed (descent, approach, taxi) : High pressure compressor may be the cause; Contact CFM to define cycles extension.
   (2) If the fault symptom is identified on the lower ECAM display unit by the crew observation ENG1/2 - CORE VIB higher than or equal to 4.2 units and less than 5.4 units for less than one minute, but intermittently repeated:
     (a) Do a check of the wiring, connectors and receptacles ASM 773202 between:
  • the No. 1 bearing vibration sensor (4002EV) and the EVMU (2EV),
  • the TRF vibration sensor (4003EV) and the EVMU (2EV).
     (b) Disconnect the harnesses from the No. 1 bearing and the TRF sensors.
       1 If damage is found:
  • repair or replace as required.
       2 If no damage is found:
     (c) Do the electrical test of the No. 1 bearing vibration sensor (4002EV) AMM 77-31-10-720-001.
       1 If the resistance values are out of the limits, replace the SENSOR-NO. 1 BRG VIB [4002EV] at the next shop maintenance opportunity.
NOTE: The No. 1 bearing vibration sensor cannot be replaced on-wing.
     (d) Do an electrical test of the TRF vibration sensor:
       1 Disconnect the aircraft harness from the vibration sensor connectors. If necessary, use PLIERS - NOSE, SOFT, LONG.
       2 Measure the insulation resistance with a MEGOHMMETER 100 MOHMS between:
. pins 1 and 2
. pins 1 and 3
. pin 2 and connector body
. pin 3 and connector body.
       3 The insulation resistance is expected to be greater than 20 Megohms. If one of these measurements are less than 20 Megohms, the sensor is not serviceable.
       4 If the TRF vibration sensor is not serviceable, it must be replaced AMM 77-31-30-000-002 and AMM 77-31-30-400-002.
     (e) If nothing is found:
  • do the operational test of the Engine Vibration Monitoring Unit (EVMU) through the Centralized Fault Display System (CFDS) AMM 77-32-34-710-040.
     (f) If nothing is found:
  • Dispatch the aircraft. Vibration level must be monitored closely.
NOTE: HP unbalance is the first cause of core vibration, may be not perceptible through trouble shooting actions. The presence of high N2 vibration requires to schedule the engine removal for root cause identification at shop level.
   (3) If the fault symptom is identified on the lower ECAM display unit by the crew observation ENG1/2 - CORE VIB higher than or equal to 4.2 units and less than 5.4 units for more than one minute:
  • open the cowlings AMM 71-11-00-210-001 and do a visual inspection around the engine (centerbody plug, piping and brackets fan cowl and core cowl area).
     (a) Do a check and an inspection of the accessories and QEC components. This includes the check and inspection of:
  • the accessory gear box mounts,
  • the link and brackets of the accessories to make sure they are loose or broken,
  • the cowling brackets, hinges and rigging,
  • the pneumatic system for correct condition and rigging.
       1 If the check is not correct:
  • repair or replace as required.
     (b) If nothing is found:
       1 Do a check of the wiring, connectors and receptacles ASM 773202 between:
  • the SENSOR-NO. 1 BRG VIB [4002EV] and the EVMU (2EV),
  • the SENSOR-TRF VIB [4003EV] and the EVMU [2EV] .
       2 Disconnect the harnesses from the No. 1 bearing and the TRF sensors,
         a If damage is found:
  • repair or replace as required.
         b If no damage is found:
       3 Do an electrical test of the No. 1 bearing vibration sensor and the TRF vibration sensor:
  • disconnect the aircraft harness from the vibration sensor connectors. If necessary, use PLIERS - NOSE, SOFT, LONG.
  • measure the insulation resistance with a MEGOHMMETER 100 MOHMS between:
    . pins 1 and 2
    . pins 1 and 3
    . pin 2 and connector body
    . pin 3 and connector body,
    the insulation resistance is expected to be greater than 20 megohms.
         a If one of these measurements is less than 20 megohms:
  • the sensor is not serviceable.
         b If one of the two vibration sensors is found not serviceable:
NOTE: If the TRF vibration sensor is not serviceable, it should be replaced AMM 77-31-30-000-002 and AMM 77-31-30-400-002.
NOTE: The No. 1 bearing vibration sensor cannot be replaced on-wing.
     (c) If nothing is found:
  • do the operational test of the Engine Vibration Monitoring Unit (EVMU) through the Centralized Fault Display System (CFDS) AMM 77-32-34-710-040.
     (d) Do a check of the electric master magnetic chip detector visual indicator AMM 79-35-00-040-042 and the magnetic chip detector AMM 79-00-00-281-002 and the scavenge screen plugs AMM 79-00-00-281-003.
       1 If you find magnetic particles:
       2 If no magnetic particles are found:
     (e) If nothing is found:
     (f) If nothing is found:
  • dispatch the aircraft. Vibration level must be monitored closely and reported to CFMI on a regular basis.
[Rev.8 from Aug 2018] 2026.04.04 04:37:34 UTC
"AVIABRAIN" 2025