DOC AIRBUS | AMM A320FInspection of the Magnetic Chip Detectors for Debris [IAE]
TASK 79-00-00-200-011-A
Inspection of the Magnetic Chip Detectors for Debris
This task gives instructions on how to check the debris found on the Magnetic Chip Detectors (MCDs).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 79-00-00-941-060-A ** ON A/C NOT FOR ALL
Subtask 79-00-00-210-069-A ** ON A/C NOT FOR ALL
Subtask 79-00-00-420-051-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 13:00:43 UTC
Inspection of the Magnetic Chip Detectors for Debris
WARNING:
DO NOT LET ENGINE OIL STAY ON YOUR SKIN FOR A LONG TIME. FLUSH THE OIL FROM YOUR SKIN WITH WATER. THE OIL IS POISONOUS AND CAN GO THROUGH YOUR SKIN AND INTO YOUR BODY.
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.
CAUTION:
DO NOT LET ENGINE FUEL OR OIL FALL ON THE ENGINE. UNWANTED FUEL OR OIL MUST BE REMOVED IMMEDIATELY WITH A CLEAN LINT FREE CLOTH. THE FUEL OR OIL CAN CAUSE DAMAGE TO THE SURFACE PROTECTION AND TO SOME PARTS.
ZONE: 400
1. Reason for the JobThis task gives instructions on how to check the debris found on the Magnetic Chip Detectors (MCDs).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | CONTAINER - CLEAN, APPLICABLE |
| No specific | AR | MAGNIFYING GLASS POWER 05X |
| No specific | AR | WARNING NOTICE(S) |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.V01-277) | Kerosine |
| (Material No.08BBD1) | Non Aqueous Cleaner-- Isopropyl Alcohol - |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-010-A | Opening of the Fan Cowls 437AL(447AL),438AR(448AR) |
| TASK 71-13-00-410-010-A | Closing of the Fan Cowls 437AL(447AL),438AR(448AR) |
| TASK 79-22-45-000-010-A | Removal of the Magnetic Chip Detector |
| TASK 79-22-45-400-010-A | Installation of the Magnetic Chip Detector |
Build DebrisSubtask 79-00-00-941-060-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
4. Procedure(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
Subtask 79-00-00-210-069-A ** ON A/C NOT FOR ALL
A. General
(1) It is recommended that a database must be maintained against each engine to record the following data for each MCD inspection:
(a) Record the quantity and location of the metallic debris found at each MCD inspection that does not lead to an engine or external gearbox rejection.
(b) The total engine and gearbox hours and cycles accumulated at each MCD inspection.
(c) If the MCD's were used to diagnose a possible engine or accessory impending problem, results and any metallic debris samples should also be retained.
(d) If metallic debris samples were collected from any of the filter screens, results and any metallic debris samples collected should also be retained.
(2) The debris must be examined with a MAGNIFYING GLASS POWER 05X.
(3) Refer to the flowchart for an overview of this procedure.
Subtask 79-00-00-210-070-A ** ON A/C NOT FOR ALL (1) It is recommended that a database must be maintained against each engine to record the following data for each MCD inspection:
(a) Record the quantity and location of the metallic debris found at each MCD inspection that does not lead to an engine or external gearbox rejection.
(b) The total engine and gearbox hours and cycles accumulated at each MCD inspection.
(c) If the MCD's were used to diagnose a possible engine or accessory impending problem, results and any metallic debris samples should also be retained.
(d) If metallic debris samples were collected from any of the filter screens, results and any metallic debris samples collected should also be retained.
(2) The debris must be examined with a MAGNIFYING GLASS POWER 05X.
(3) Refer to the flowchart for an overview of this procedure.
B. Types of Debris
(1) There are five main types of debris found on MCDs and in filters. They are: build debris, magnetic fines, slivers, metallic flakes and chips.
This is unwanted material that is accidentally left in the engine when it is assembled. The build debris comes from machine operations when the components are made. When the material is broken it can look the same as gear or steel seal material.
These are very small steel particles which show as a black sludge on the MCD. When the oil is removed they show as dull hair like slivers. Fines come from permitted engine wear. Bearing skid can also make fines, but the increased quantity will show during the analysis of MCD samples. Fines are usually found on engines that have operated for only a short time since new, repair or overhaul. Fines are less than 0.020 in. (0.51 mm) in length and width.
(c) Slivers
These are small, slender, brittle strands of metal. A sliver can be long, but width is not more than 0.020 in. (0.51 mm). A metallic sliver can resemble a single strand of hair. When broken into smaller pieces, a sliver will become fines.
(d) Chips
These are very thick flakes or pieces of metal which usually have one smooth machined surface. The opposite surface is rough and irregular. Chips are more than 0.020 in. (0.51 mm) in length and width as well as having a thickness.
(e) Metallic Flakes
Metallic flakes come from these components; ball bearings, roller bearings and gear teeth. Flakes that have an irregular shape must be examined to find their origin.
1 Ball bearing and ball bearing track flakes are usually almost circular with radial cracks. When the flake is clean, the shiny side is much brighter than other types of flake. The shiny side also has small scratches which go across each other.
2 Roller bearing and roller bearing track flakes are usually almost rectangular in shape. When the flake is clean, the shiny side is much brighter than other types of flake. The shiny side has small scratches which go accross each other.
3 Gear teeth flakes are shiny with an irregular shape. They are usually thicker and not as bright as ball or roller bearing flakes.
4 Any flakes are more than 0.020 in. (0.51 mm) in length and width.
Subtask 79-00-00-010-060-A ** ON A/C NOT FOR ALL Subtask 79-00-00-210-101-A ** ON A/C NOT FOR ALL (1) There are five main types of debris found on MCDs and in filters. They are: build debris, magnetic fines, slivers, metallic flakes and chips.
NOTE: Make sure that debris is metallic. Coke or carbon particles are not debris (crush if necessary to help determine the composition of debris).
(a) Build Debris This is unwanted material that is accidentally left in the engine when it is assembled. The build debris comes from machine operations when the components are made. When the material is broken it can look the same as gear or steel seal material.
NOTE: Build debris is usually found during the first 1000 hours of operation.
(b) Magnetic Fines These are very small steel particles which show as a black sludge on the MCD. When the oil is removed they show as dull hair like slivers. Fines come from permitted engine wear. Bearing skid can also make fines, but the increased quantity will show during the analysis of MCD samples. Fines are usually found on engines that have operated for only a short time since new, repair or overhaul. Fines are less than 0.020 in. (0.51 mm) in length and width.
(c) Slivers
These are small, slender, brittle strands of metal. A sliver can be long, but width is not more than 0.020 in. (0.51 mm). A metallic sliver can resemble a single strand of hair. When broken into smaller pieces, a sliver will become fines.
(d) Chips
These are very thick flakes or pieces of metal which usually have one smooth machined surface. The opposite surface is rough and irregular. Chips are more than 0.020 in. (0.51 mm) in length and width as well as having a thickness.
(e) Metallic Flakes
Metallic flakes come from these components; ball bearings, roller bearings and gear teeth. Flakes that have an irregular shape must be examined to find their origin.
1 Ball bearing and ball bearing track flakes are usually almost circular with radial cracks. When the flake is clean, the shiny side is much brighter than other types of flake. The shiny side also has small scratches which go across each other.
2 Roller bearing and roller bearing track flakes are usually almost rectangular in shape. When the flake is clean, the shiny side is much brighter than other types of flake. The shiny side has small scratches which go accross each other.
3 Gear teeth flakes are shiny with an irregular shape. They are usually thicker and not as bright as ball or roller bearing flakes.
4 Any flakes are more than 0.020 in. (0.51 mm) in length and width.
D. Examine the Magnetic Chip Detectors (MCDs)
(1) Examine the master MCD.
(a) Remove master MCD (Ref. AMM TASK 79-22-45-000-010).
1 If metallic debris is found, refer to step 4.D.(2).
2 If master MCD is clean, go to Para. 5. Close-up (engine is acceptable).
(2) Examine all MCDs.
(a) Remove all MCDs (Ref. AMM TASK 79-22-45-000-010).
(b) If there is metallic debris:
1 Make a record of the position of the plug.
2 Examine the debris on the MCD with a MAGNIFYING GLASS POWER 05X.
3 Make a record of the quantity and type of debris contamination.
4 Collect the debris in a CONTAINER - CLEAN, APPLICABLE.
a If material is identified as build debris, go to Para. 5. Close-up (build debris is acceptable).
b If material is identified as fines or slivers, refer to step 4.E.(1).
c If material is identified as chips or flakes, refer to step 4.E.(2).
Subtask 79-00-00-210-065-A ** ON A/C NOT FOR ALL (1) Examine the master MCD.
(a) Remove master MCD (Ref. AMM TASK 79-22-45-000-010).
1 If metallic debris is found, refer to step 4.D.(2).
2 If master MCD is clean, go to Para. 5. Close-up (engine is acceptable).
(2) Examine all MCDs.
(a) Remove all MCDs (Ref. AMM TASK 79-22-45-000-010).
(b) If there is metallic debris:
1 Make a record of the position of the plug.
2 Examine the debris on the MCD with a MAGNIFYING GLASS POWER 05X.
3 Make a record of the quantity and type of debris contamination.
4 Collect the debris in a CONTAINER - CLEAN, APPLICABLE.
a If material is identified as build debris, go to Para. 5. Close-up (build debris is acceptable).
b If material is identified as fines or slivers, refer to step 4.E.(1).
c If material is identified as chips or flakes, refer to step 4.E.(2).
NOTE: A description of the debris can be found above, refer to step 4.B.
E. Action Based on Type of Material Found on Magnetic Chip Detectors (MCDs)
(1) Fines or slivers
1 If no, go to Para. 5. Close-up (engine is acceptable).
2 If yes, refer to step 4.E.(1)(b).
(b) Inspect the scavenge oil filter.
1 Was metallic debris found in the scavenge oil filter?
Examine the master MCD and affected MCD at 25 hours (+/- 5 hours) intervals for a minimum of 100 flight hours.
If the quantity of the debris found at each inspection increases, reject the engine or gearbox.
If the quantity of the debris found at each inspection decreases, return the engine to the standard MCD inspection interval after 100 hours are completed.
(2) Chips or flakes
1 If yes, save the debris for later analysis and refer to step 4.E.(2)(b).
2 If no, save the debris for later analysis and refer to step 4.E.(2).(d).
(b) Examine the scavenge filter.
1 Did the scavenge oil filter have metallic debris covering an area more than 0.25 in.2 (161.29 mm2)?
a If yes, reject the engine or gearbox.
b If no, refer to step 4.E.(2)(c).
(c) Send all of the collected metallic debris out for analysis and wait for the analysis to be completed and the debris composition to be determined before any further flights, refer to step 4.E.(2)(f).
(d) Examine the scavenge filter.
1 Did the scavenge oil filter have metallic debris covering an area more than 0.25 in.2 (161.29 mm2)?
a If yes, reject the engine or gearbox.
b If no, refer to step 4.E.(2)(e).
(e) Send all of the collected metallic debris out for analysis.
1 Return the engine to service on a reduced MCD inspection interval as follows:
1 Does the debris analysis confirm bearing material?
5. Close-up(1) Fines or slivers
NOTE: Reference flow charts to aid in troubleshooting.
(a) Do the fines and slivers cover more than half the circumference of the MCD? 1 If no, go to Para. 5. Close-up (engine is acceptable).
2 If yes, refer to step 4.E.(1)(b).
(b) Inspect the scavenge oil filter.
1 Was metallic debris found in the scavenge oil filter?
- If no, go to Para. 5. Close-up (engine is acceptable).
- If yes, go to Para. 5. Close-up (engine is acceptable).
- If no, refer to step 4.E.(1)(b)1_b_.
- If yes, reject the engine or gearbox.
- If no, return the engine to service on a reduced MCD inspection interval as follows:
Examine the master MCD and affected MCD at 25 hours (+/- 5 hours) intervals for a minimum of 100 flight hours.
If the quantity of the debris found at each inspection increases, reject the engine or gearbox.
If the quantity of the debris found at each inspection decreases, return the engine to the standard MCD inspection interval after 100 hours are completed.
(2) Chips or flakes
NOTE: Reference the flow chart to aid in troubleshooting.
NOTE: Contact IAE CTS if bearing material is found within the first 1000 hours of operation after engine overhaul.
(a) Were there more than ten chips/flakes found? 1 If yes, save the debris for later analysis and refer to step 4.E.(2)(b).
2 If no, save the debris for later analysis and refer to step 4.E.(2).(d).
(b) Examine the scavenge filter.
1 Did the scavenge oil filter have metallic debris covering an area more than 0.25 in.2 (161.29 mm2)?
a If yes, reject the engine or gearbox.
b If no, refer to step 4.E.(2)(c).
(c) Send all of the collected metallic debris out for analysis and wait for the analysis to be completed and the debris composition to be determined before any further flights, refer to step 4.E.(2)(f).
(d) Examine the scavenge filter.
1 Did the scavenge oil filter have metallic debris covering an area more than 0.25 in.2 (161.29 mm2)?
a If yes, reject the engine or gearbox.
b If no, refer to step 4.E.(2)(e).
(e) Send all of the collected metallic debris out for analysis.
1 Return the engine to service on a reduced MCD inspection interval as follows:
- Examine the master MCD and affected MCD at 25 hours (+/- 5 hours) intervals for a minimum of 100 flight hours.
- If the quantity of debris found at each inspection increases, reject the engine or gearbox.
- When debris analysis is complete, immediately refer to step 4.E.(2)(f).
1 Does the debris analysis confirm bearing material?
NOTE: Bearing material includes any of the following materials AMS6490/M50, AMS6278/M50 NiL, AMS6440/52100 and AMS6414/SAE 4340*.
*AMS6414/SAE 4340 should only be treated as bearing material when silver (Ag) plating is also found (reference SIL225 for guidance).
a If no, return engine to service on a reduced MCD inspection interval as follows: *AMS6414/SAE 4340 should only be treated as bearing material when silver (Ag) plating is also found (reference SIL225 for guidance).
- If engine was already on a reduced MCD inspection interval, take those hours already completed into account.
- Ensure that at least four 25 hours (+/- 5 hours) MCD inspection intervals were completed. If the quantity of debris found at each inspection increases, reject the engine or gearbox.
- If the quantity of the debris found at each inspection decreases, return the engine to the standard MCD inspection interval.
Subtask 79-00-00-420-051-A ** ON A/C NOT FOR ALL
A. Installation of the MCDs
(1) Clean the MCD.
(a) Put the MCD into Kerosine (Material No.V01-277) or Non Aqueous Cleaner-- Isopropyl Alcohol - (Material No.08BBD1) .
(2) Install clean MCDs (Ref. AMM TASK 79-22-45-400-010).
Subtask 79-00-00-410-060-A ** ON A/C NOT FOR ALL Subtask 79-00-00-942-053-A ** ON A/C NOT FOR ALL (1) Clean the MCD.
(a) Put the MCD into Kerosine (Material No.V01-277) or Non Aqueous Cleaner-- Isopropyl Alcohol - (Material No.08BBD1) .
(2) Install clean MCDs (Ref. AMM TASK 79-22-45-400-010).
C. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the WARNING NOTICE(S).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the WARNING NOTICE(S).