DOC AIRBUS | AMM A320FPartial Replacement of the Abradable Liner with Large Circular Patches [CFMB]
TASK 72-23-00-300-807-A
Partial Replacement of the Abradable Liner with Large Circular Patches
Defects more than 0.12 in (3 mm) deep and 0.50 in.2 (3.2 cm2) in surface and with fan case base metal exposed. This task refers to a procedure for the in-place of the abradable liner by installation of large circular patches with maximum diameter of 3.94 in (100 mm).
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 72-23-00-941-112-A ** ON A/C NOT FOR ALL
Subtask 72-23-00-320-068-A ** ON A/C NOT FOR ALL
Subtask 72-23-00-410-137-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:42:09 UTC
Partial Replacement of the Abradable Liner with Large Circular Patches
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
CAUTION:
DURING THE REPAIR OF THE ABRADABLE LINER OF THE FAN INLET CASE, MAKE SURE THAT:
- THE AREA STAYS DRY, WITHOUT DUST AND WELL VENTILATED
- THE TEMPERATURE STAYS BETWEEN 64 DEG.F (18 DEG.C) AND 82 DEG.F (28 DEG.C)
- THE RELATIVE HUMIDITY STAYS BETWEEN 40 AND 70 PERCENT.
ZONE: 400
1. Reason for the JobDefects more than 0.12 in (3 mm) deep and 0.50 in.2 (3.2 cm2) in surface and with fan case base metal exposed. This task refers to a procedure for the in-place of the abradable liner by installation of large circular patches with maximum diameter of 3.94 in (100 mm).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE |
| No specific | 1 | GUN - HOT AIR |
| No specific | 1 | HEAT SOURCE - RADIANT |
| No specific | 1 | LIGHT SOURCE - WHITE |
| No specific | 1 | MAGNIFYING GLASS POWER 10X |
| No specific | 1 | MAGNIFYING GLASS POWER 20X |
| No specific | 1 | MAT - PROTECTIVE |
| No specific | 1 | PAINTBRUSH |
| No specific | 1 | PUNCH - CUTTING |
| No specific | 1 | SCALPEL |
| No specific | 1 | VACUUM CLEANER |
| No specific | AR | WARNING NOTICE(S) |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP1039) | acetone |
| (Material No.CP1041) | isopropyl alcohol |
| (Material No.CP2244) | primer 1200 |
| (Material No.CP2297) | RTV 147 A |
| (Material No.CP2298) | Catalyst 147 B |
| (Material No.CP2306) | 3M 5490 tape |
| (Material No.CP2339) | RTV 630 |
| (Material No.CP2674) | lint-free cloth |
| (Material No.CP2772) | abrasive cloth |
| (Material No.CP5061) | temporary marking |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 72-21-00-000-005-A | Removal of the Spinner Front Cone |
| TASK 72-21-00-000-006-A | Removal of the Spinner Rear Cone |
| TASK 72-21-00-000-007-A | Removal of the Fan Rotor Blades |
| TASK 72-21-00-400-005-A | Installation of the Spinner Front Cone |
| TASK 72-21-00-400-006-A | Installation of the Spinner Rear Cone |
| TASK 72-21-00-400-007-A | Installation of the Fan Rotor Blades |
| TASK 72-23-00-000-009-A | Removal of the Forward Acoustical Panels of the Fan |
| TASK 72-23-00-000-025-A | Removal of the Mid Acoustical Panels |
| TASK 72-23-00-210-004-A | Visual Inspection of the Fan Frame Assembly |
| TASK 72-23-00-300-806-A | Partial Replacement of the Abradable Liner with Square/Rectangular Patches |
| TASK 72-23-00-400-009-A | Installation of the Forward Acoustical Panels of the Fan |
| TASK 72-23-00-400-025-A | Installation of the Mid Acoustical Panels |
| SPM 706613380025 | |
Fan Inlet Case - Abradable Liner Repair with Circular PatchesSubtask 72-23-00-941-112-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Put a WARNING NOTICE(S) in position to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than five minutes before you do this procedure.
(3) On 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) in position to tell persons not to energize FADEC 1(2).
Subtask 72-23-00-010-145-A ** ON A/C NOT FOR ALL (1) On the center pedestal, on ENG panel 115VU:
(a) Put a WARNING NOTICE(S) in position to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than five minutes before you do this procedure.
(3) On 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) in position to tell persons not to energize FADEC 1(2).
B. Get Access
(1) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position.
(2) Install the MAT - PROTECTIVE in the lower half of the inlet cowl.
(3) Remove the spinner front cone (Ref. AMM TASK 72-21-00-000-005).
(4) Remove the spinner rear cone (Ref. AMM TASK 72-21-00-000-006).
4. Procedure(1) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position.
(2) Install the MAT - PROTECTIVE in the lower half of the inlet cowl.
(3) Remove the spinner front cone (Ref. AMM TASK 72-21-00-000-005).
(4) Remove the spinner rear cone (Ref. AMM TASK 72-21-00-000-006).
Subtask 72-23-00-320-068-A ** ON A/C NOT FOR ALL
A. Repair the damaged areas of the abradable liner.
(1) Measure the clearance between the fan blade tip and abradable liner at eight equally spaced locations as follows:
(a) Use the No. 1 fan blade as a reference to remove the influence of the fan blade length.
(b) Make a record of the dimensions.
(2) Remove a sufficient amount of fan blades to get access to the repair area (Ref. AMM TASK 72-21-00-000-007).
(3) Find the forward and middle acoustic panel attachment screws.
(a) Remove the screws but keep the acoustic panels in position (Ref. AMM TASK 72-23-00-000-009) and (Ref. AMM TASK 72-23-00-000-025).
(4) Use temporary marking (Material No.CP5061) and make a circular mark on the abradable liner around the damaged area.
(a) Make the cut on the circular mark around the damaged/repair area.
(b) Continue to make cuts to remove as much of the damaged abradable liner as possible.
(c) After you remove the damaged abradable liner, make sure that the diameter of the repair area is 3.94 in. (100 mm) or less.
(e) Use abrasive cloth (Material No.CP2772) 80 or 120 grit to make the surface of the fan inlet case rough at the repair area.
Subtask 72-23-00-110-058-A ** ON A/C NOT FOR ALL (1) Measure the clearance between the fan blade tip and abradable liner at eight equally spaced locations as follows:
(a) Use the No. 1 fan blade as a reference to remove the influence of the fan blade length.
(b) Make a record of the dimensions.
(2) Remove a sufficient amount of fan blades to get access to the repair area (Ref. AMM TASK 72-21-00-000-007).
(3) Find the forward and middle acoustic panel attachment screws.
(a) Remove the screws but keep the acoustic panels in position (Ref. AMM TASK 72-23-00-000-009) and (Ref. AMM TASK 72-23-00-000-025).
(4) Use temporary marking (Material No.CP5061) and make a circular mark on the abradable liner around the damaged area.
WARNING:
BE CAREFUL WHEN YOU USE SHARP OR POINTED TOOLS. THESE TOOLS CAN CAUSE AN INJURY TO YOU.
(5) Cut the abradable liner material with a SCALPEL to the base metal at the location of the damage as follows: (a) Make the cut on the circular mark around the damaged/repair area.
(b) Continue to make cuts to remove as much of the damaged abradable liner as possible.
(c) After you remove the damaged abradable liner, make sure that the diameter of the repair area is 3.94 in. (100 mm) or less.
WARNING:
WHEN YOU DRILL, MACHINE, BLEND, GRIND OR SAND PARTS, USE PROTECTIVE CLOTHING, GLOVES, DUST MASK AND GOGGLES.
BE CAREFUL NOT TO BREATHE THE DUST OR LET IT TOUCH YOUR SKIN.
DUST AND PARTICLES ARE DANGEROUS FOR YOUR HEALTH.
(d) Use abrasive cloth (Material No.CP2772) , 80 or 120 grit, and sand to remove all the remaining abradable liner material that you could not remove with the SCALPEL. (e) Use abrasive cloth (Material No.CP2772) 80 or 120 grit to make the surface of the fan inlet case rough at the repair area.
WARNING:
WHEN YOU USE COMPRESSED AIR:
(6) Use clean shop air or a VACUUM CLEANER to remove all unwanted pieces of the abradable liner material, dust and hand sanding residue. - USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
- DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS
- DO NOT LET THE PRESSURE BE MORE THAN 30 PSIG (200 KPA).
B. Clean the repair area with acetone (Material No.CP1039) or isopropyl alcohol (Material No.CP1041) .
Subtask 72-23-00-220-053-A ** ON A/C NOT FOR ALL C. Do a visual inspection of the fan case base metal. Use a LIGHT SOURCE - WHITE and a MAGNIFYING GLASS POWER 10X or a MAGNIFYING GLASS POWER 20X as follows:
(1) Refer to the following limits:
(a) Scratches up to 0.001 in. (0.025 mm) in depth are considered uninterpretable and are permitted.
(b) Nicks up to 0.001 in. (0.025 mm) in depth are considered uninterpretable and are permitted.
(c) Dents up to 0.002 in. (0.051 mm) n depth are considered uninterpretable and are permitted.
(2) If you find indications during visual inspection, the abradable liner cannot be repaired using this procedure. To complete the repair of the liner, do the partial replacement of the abradable liner with square/rectangular patches procedure (Ref. AMM TASK 72-23-00-300-806).
Subtask 72-23-00-340-059-A ** ON A/C NOT FOR ALL (1) Refer to the following limits:
(a) Scratches up to 0.001 in. (0.025 mm) in depth are considered uninterpretable and are permitted.
(b) Nicks up to 0.001 in. (0.025 mm) in depth are considered uninterpretable and are permitted.
(c) Dents up to 0.002 in. (0.051 mm) n depth are considered uninterpretable and are permitted.
(2) If you find indications during visual inspection, the abradable liner cannot be repaired using this procedure. To complete the repair of the liner, do the partial replacement of the abradable liner with square/rectangular patches procedure (Ref. AMM TASK 72-23-00-300-806).
D. Apply the abradable liner patch to the case repair area as follows:
(1) Prepare the abradable liner patch as follows:
(a) From a (spare) new fan inlet case abradable cartridge (refer to EIPC 72230065 item 375), cut the abradable liner patch.
(c) Hand-blend the bottom and the edges of the abradable liner patch with abrasive cloth (Material No.CP2772) .
(d) Use a PUNCH - CUTTING or an equivalent tool to make one 0.12 in. (3.0 mm) diameter vent hole at the center of the abradable liner patch. If the abradable liner patch is larger than 3 in. (76 mm), use a PUNCH - CUTTING or equivalent tool to make 4-6 additional vent holes, evenly spaced, with a diameter of 0.12 in. (3.0 mm).
1 Remove the abradable liner material from the PUNCH - CUTTING or equivalent tool and keep it.
Subtask 72-23-00-340-060-A ** ON A/C NOT FOR ALL (1) Prepare the abradable liner patch as follows:
(a) From a (spare) new fan inlet case abradable cartridge (refer to EIPC 72230065 item 375), cut the abradable liner patch.
WARNING:
BE CAREFUL WHEN YOU USE SHARP OR POINTED TOOLS. THESE TOOLS CAN CAUSE AN INJURY TO YOU.
(b) Cut the abradable liner patch at the equivalent dimension of the repair area. (c) Hand-blend the bottom and the edges of the abradable liner patch with abrasive cloth (Material No.CP2772) .
(d) Use a PUNCH - CUTTING or an equivalent tool to make one 0.12 in. (3.0 mm) diameter vent hole at the center of the abradable liner patch. If the abradable liner patch is larger than 3 in. (76 mm), use a PUNCH - CUTTING or equivalent tool to make 4-6 additional vent holes, evenly spaced, with a diameter of 0.12 in. (3.0 mm).
1 Remove the abradable liner material from the PUNCH - CUTTING or equivalent tool and keep it.
NOTE: The abradable liner material can be used to make a plug for the vent hole after the final application of the bonding compound.
E. Prepare the bonding compound SPM 706613380025 as follows:
(2) Mix 10 parts of Catalyst 147 B (Material No.CP2298) with 100 parts of RTV 147 A (Material No.CP2297) or RTV 630 (Material No.CP2339) at a temperature range between 64 deg.F (18 deg.C) and 82 deg.F (28 deg.C).
(3) Mix the bonding compound slowly to prevent air bubbles.
(4) Mix the bonding compound manually or mechanically to get a homogeneous bonding compound.
(5) Make sure that the bonding compound does not contain air bubbles.
Subtask 72-23-00-370-055-A ** ON A/C NOT FOR ALL CAUTION:
USE THE BONDING COMPOUND LESS THAN 2 HOURS AFTER MIXING. IF YOU DO NOT OBEY THIS INSTRUCTION, THE BONDING OF THE ABRADABLE LINER PATCHES WILL NOT BE SATISFACTORY.
(1) Use the bonding compound in less than two hours after mixing. (2) Mix 10 parts of Catalyst 147 B (Material No.CP2298) with 100 parts of RTV 147 A (Material No.CP2297) or RTV 630 (Material No.CP2339) at a temperature range between 64 deg.F (18 deg.C) and 82 deg.F (28 deg.C).
(3) Mix the bonding compound slowly to prevent air bubbles.
(4) Mix the bonding compound manually or mechanically to get a homogeneous bonding compound.
(5) Make sure that the bonding compound does not contain air bubbles.
F. Remove the grease from the case repair area and the abradable liner patch with a clean lint-free cloth (Material No.CP2674) soaked in acetone (Material No.CP1039) or isopropyl alcohol (Material No.CP1041) and do as follows:
(1) Wait 30 minutes before you apply the primer.
Subtask 72-23-00-370-056-A ** ON A/C NOT FOR ALL (1) Wait 30 minutes before you apply the primer.
G. Apply primer 1200 (Material No.CP2244) on the case as follows:
(2) Dry at a temperature between 64 deg.F (18 deg.C) and 82 deg.F (28 deg.C) for 45 minutes and do as follows:
(a) Bond the abradable liner patch one hour or less after the primer is dry.
Subtask 72-23-00-340-061-A ** ON A/C NOT FOR ALL CAUTION:
BEFORE YOU APPLY THE PRIMER, MAKE SURE THAT THE REPAIR AREA IS FULLY CLEAN AND WITHOUT OIL PARTICLES.
WHEN YOU APPLY THE PRIMER, BE CAREFUL NOT TO APPLY TOO MUCH OF IT.
AFTER YOU APPLIED THE PRIMER, BE CAREFUL NOT TO TOUCH IT.
IF YOU DO NOT OBEY THESE INSTRUCTIONS, YOU CAN DECREASE THE ADHERENCE OF THE PATCH TO THE CASE.
(1) Apply primer 1200 (Material No.CP2244) with a lint-free cloth (Material No.CP2674) or a clean PAINTBRUSH on the rough area without grease. (2) Dry at a temperature between 64 deg.F (18 deg.C) and 82 deg.F (28 deg.C) for 45 minutes and do as follows:
(a) Bond the abradable liner patch one hour or less after the primer is dry.
H. Apply bonding compound on the case, at the bottom and on the edges of the abradable liner patch.
Subtask 72-23-00-340-062-A ** ON A/C NOT FOR ALL I. Bond the abradable liner patch as follows:
(1) Insert the abradable liner patch into the repair area.
(2) Use firm finger pressure to push the abradable liner patch into the repair area/circular hole.
(3) Continue to apply a firm finger pressure around the edges of the abradable liner patch to remove unwanted bonding compound and entrapped air.
(4) When you push all of the unwanted bonding compound and entrapped air to the surface of the abradable liner, plug the vent holes with the abradable liner vent hole plugs.
(5) Remove the remaining bonding compound from the surfaces of the abradable liner with a lint-free cloth (Material No.CP2674) before polymerization.
(6) Hold the abradable liner patch in its position as follows:
(a) For abradable liner patches with a maximum diameter of 1.97 in. (50 mm), use 3M 5490 tape (Material No.CP2306) .
(b) For abradable liner patches with a diameter larger than 1.97 in. (50 mm), use a push rod or equivalent tool to hold the patch in its position.
Subtask 72-23-00-340-063-A ** ON A/C NOT FOR ALL (1) Insert the abradable liner patch into the repair area.
(2) Use firm finger pressure to push the abradable liner patch into the repair area/circular hole.
(3) Continue to apply a firm finger pressure around the edges of the abradable liner patch to remove unwanted bonding compound and entrapped air.
(4) When you push all of the unwanted bonding compound and entrapped air to the surface of the abradable liner, plug the vent holes with the abradable liner vent hole plugs.
(5) Remove the remaining bonding compound from the surfaces of the abradable liner with a lint-free cloth (Material No.CP2674) before polymerization.
(6) Hold the abradable liner patch in its position as follows:
(a) For abradable liner patches with a maximum diameter of 1.97 in. (50 mm), use 3M 5490 tape (Material No.CP2306) .
(b) For abradable liner patches with a diameter larger than 1.97 in. (50 mm), use a push rod or equivalent tool to hold the patch in its position.
J. Cure the abradable liner patch as follows:
Subtask 72-23-00-210-072-A ** ON A/C NOT FOR ALL WARNING:
USE THERMAL GLOVES WHEN YOU MOVE OR TOUCH HOT OR COLD PARTS. HOT OR COLD PARTS CAN CAUSE INJURY.
(1) Use a HEAT SOURCE - RADIANT, GUN - HOT AIR or an equivalent tool to increase the temperature of the patch to between 194 deg.F (90 deg.C) and 212 deg.F (100 deg.C) and keep the abradable liner patch at this temperature range for 1.25 to 1.5 hours to cure the bonding compound. K. Do a quality check of the abradable liner patch as follows:
(1) Examine all the joints and the abradable liner patch areas to make sure that there are no trapped air bubbles or missing material.
(2) If you find trapped air bubbles or missing material in the joints, do the repair again.
Subtask 72-23-00-340-064-A ** ON A/C NOT FOR ALL (1) Examine all the joints and the abradable liner patch areas to make sure that there are no trapped air bubbles or missing material.
(2) If you find trapped air bubbles or missing material in the joints, do the repair again.
L. Blend the abradable liner patch as follows:
(2) Get the record of clearance measurements from Para. 4.A.(1).
(3) Blend the abradable liner repair area to the contour and dimensions of the adjacent areas.
Subtask 72-23-00-230-052-A ** ON A/C NOT FOR ALL WARNING:
WHEN YOU DRILL, MACHINE, BLEND, GRIND OR SAND PARTS, USE PROTECTIVE CLOTHING, GLOVES, DUST MASK AND GOGGLES.
BE CAREFUL NOT TO BREATHE THE DUST OR LET IT TOUCH YOUR SKIN.
DUST AND PARTICLES ARE DANGEROUS FOR YOUR HEALTH.
(1) Use the abrasive cloth (Material No.CP2772) . (2) Get the record of clearance measurements from Para. 4.A.(1).
(3) Blend the abradable liner repair area to the contour and dimensions of the adjacent areas.
M. Do a final quality check of the abradable liner patch as follows:
(1) For scratches, scores, nicks, and dents, apply the limits that follow:
(3) If the final quality check does not agree with the requirements, do the repair again.
Subtask 72-23-00-140-054-A ** ON A/C NOT FOR ALL (1) For scratches, scores, nicks, and dents, apply the limits that follow:
- The length of a defect/damage: 0.196 in. (4.98 mm) or less
- The minimum distance between two damaged locations: 1.97 in. (50.0 mm)
- The maximum depth of the damage: 0.118 in. (3.00 mm) or less
- The number of damaged areas for 3.93 in.2 (2535.5 mm2): three or less.
(3) If the final quality check does not agree with the requirements, do the repair again.
N. Remove loose abradable material and dust from the case repair area with a VACUUM CLEANER.
Subtask 72-23-00-420-085-A ** ON A/C NOT FOR ALL O. Install the forward and middle acoustical panels screws with the correct torque (Ref. AMM TASK 72-23-00-400-009) and (Ref. AMM TASK 72-23-00-400-025).
Subtask 72-23-00-420-086-A ** ON A/C NOT FOR ALL 5. Close-upSubtask 72-23-00-410-137-A ** ON A/C NOT FOR ALL
A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the spinner rear cone (Ref. AMM TASK 72-21-00-400-006).
(3) Install the spinner front cone (Ref. AMM TASK 72-21-00-400-005).
(4) Remove the MAT - PROTECTIVE from the inlet cowl.
(5) Remove the access platform(s).
(6) Remove the WARNING NOTICE(S).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the spinner rear cone (Ref. AMM TASK 72-21-00-400-006).
(3) Install the spinner front cone (Ref. AMM TASK 72-21-00-400-005).
(4) Remove the MAT - PROTECTIVE from the inlet cowl.
(5) Remove the access platform(s).
(6) Remove the WARNING NOTICE(S).