DOC AIRBUS | AMM A320FPermitted Damage and Defects on Hydraulic Tubing
TASK 20-23-11-200-001-A
Permitted Damage and Defects on Hydraulic Tubing
This procedure is applicable to:
A. Consumable Materials
B. Referenced Information
3. Job Set-up
Subtask 20-23-11-869-058-A
Subtask 20-23-11-210-071-A
[Rev.10 from 2021]
2026.04.01 04:47:08 UTC
Permitted Damage and Defects on Hydraulic Tubing
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1. Reason for the JobThis procedure is applicable to:
- Titanium-alloy (Ti-3Al-2.5V) tubes ref. ABS5004, sizes -04 to -16
- Corrosion-resistant steel (21-6-9) tubes ref. ASNA3288, sizes -04 to -24
- Aluminum-alloy (6061-T6) tubes ref. ASNA3410 and DAN40, sizes -04 to -16 and -24.
A. Consumable Materials
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.04CMA2) | Wash Primer_- - Structure |
| (Material No.04EAC2) | Primer Polyurethane Paint_- Corrosion Inhibiting Structure |
| (Material No.04JAA3) | Top Coat Polyurethane_- - External Structure |
| (Material No.06CMD9) | Silicone Adhesive Sealant-General Purpose One part legacy |
| (Material No.08BAA9) | Non Aqueous Cleaner-General - - |
| (Material No.10ABC1) | Surface Pretreatment-Light Alloys Chemical Conversion Yellow - |
| (Material No.14FAB1) | Abrasive-- Scotch Brite Pads - |
| (Material No.14SBA1) | Textile-Lint free Cotton - |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 20-23-11-300-005-A | Repair of Titanium-Alloy Hydraulic Tubes with HARRISON Sleeves and Unions |
| TASK 20-23-11-300-802-A | Repair of Fire Protection Sleeves on Pipes in the Pylon Area |
| TASK 20-23-11-911-001-A | Installation of the Hydraulic Tubes |
Subtask 20-23-11-869-058-A
A. Not Applicable
4. ProcedureSubtask 20-23-11-210-071-A
A. Damage and Defects not Permitted on Hydraulic Tubing
(1) If necessary, clean the hydraulic tube with a Textile-Lint free Cotton - (Material No.14SBA1) and Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(2) Damage that is not permitted:
(3) Find and remove the root cause of chafing before the next flight.
Subtask 20-23-11-210-068-A (1) If necessary, clean the hydraulic tube with a Textile-Lint free Cotton - (Material No.14SBA1) and Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(2) Damage that is not permitted:
- Measured damage that is not in the permitted tolerances
- Corrosion pits and cracks.
(3) Find and remove the root cause of chafing before the next flight.
B. Permitted Damage and Defects on the Hydraulic Tubing
(2) Measure the damage (permitted defect depth on a tube):
(a) For deformation of the tube (when the wall thickness is not decreased) such as wrinkles, dents/bulges or impressions, the maximum permitted damage (Type A) is:
1 Tolerance without a time limit:
2 Tolerance with a time limit (grace period):
(b) For the removal of the material (surface damage) such as notches, scratches, grooves or chafing, the maximum permitted damage (Type B) is:
1 Tolerance without a time limit:
2 Tolerance with a time limit (grace period):
(3) If the measured damage is in the tolerance, do these protection steps:
(a) Clean with the Textile-Lint free Cotton - (Material No.14SBA1) and a Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(b) Rub with the Abrasive-- Scotch Brite Pads - (Material No.14FAB1) .
(c) Clean with the Textile-Lint free Cotton - (Material No.14SBA1) and a Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(d) Apply protection:
1 For aluminum alloy (6061-T6) tubes:
Subtask 20-23-11-210-061-A NOTE: This procedure is not applicable to the tubes in the engine area. You can refer to the engine manufacturer's instructions for repairs of the tubes in the engine area.
(1) Clean with Textile-Lint free Cotton - (Material No.14SBA1) and Non Aqueous Cleaner-General - - (Material No.08BAA9) .(2) Measure the damage (permitted defect depth on a tube):
(a) For deformation of the tube (when the wall thickness is not decreased) such as wrinkles, dents/bulges or impressions, the maximum permitted damage (Type A) is:
1 Tolerance without a time limit:
- 1% of the Outside Diameter (OD) of the tube
- 1.4% for ABS5004, size-16.
NOTE: The damaged pipe can stay in operation with no time limit.
| OD DASH | OUTSIDE DIAMETER OD | TYPE A (without material removal) | ||||||
|---|---|---|---|---|---|---|---|---|
| -4 | 6.35 | 1/4 | 0.06 | 0.003 | 0.06 | 0.003 | 0.06 | 0.003 |
| -6 | 9.53 | 3/8 | 0.10 | 0.004 | 0.10 | 0.004 | 0.10 | 0.004 |
| -8 | 12.70 | 1/2 | 0.13 | 0.005 | 0.13 | 0.005 | 0.13 | 0.005 |
| -10 | 15.88 | 5/8 | 0.16 | 0.006 | 0.16 | 0.006 | 0.16 | 0.006 |
| -12 | 19.05 | 3/4 | 0.19 | 0.008 | 0.19 | 0.008 | 0.19 | 0.008 |
| -16 | 25.40 | 1 | 0.25 | 0.010 | 0.25 | 0.010 | 0.36 | 0.014 |
| -20 | 31.75 | 1-1/4 | 0.32 | 0.013 | - | - | - | - |
| -24 | 38.10 | 1-1/2 | 0.38 | 0.015 | 0.38 | 0.015 | - | - |
- The damage must not be more than 1.5% of the OD of the tube.
- The damage must be in the straight area of the pipe, not in a bend.
- You must replace the damaged pipe before 750 Flight Hours (FH), 750 flight cycles or 4 months, whichever comes first.
| OD DASH | OUTSIDE DIAMETER OD | TYPE A (without material removal) | ||||||
|---|---|---|---|---|---|---|---|---|
| -4 | 6.35 | 1/4 | 0.10 | 0.004 | 0.10 | 0.004 | 0.10 | 0.004 |
| -6 | 9.53 | 3/8 | 0.14 | 0.006 | 0.14 | 0.006 | 0.14 | 0.006 |
| -8 | 12.70 | 1/2 | 0.19 | 0.008 | 0.19 | 0.008 | 0.19 | 0.008 |
| -10 | 15.88 | 5/8 | 0.24 | 0.009 | 0.24 | 0.009 | 0.24 | 0.009 |
| -12 | 19.05 | 3/4 | 0.29 | 0.011 | 0.29 | 0.011 | 0.29 | 0.011 |
| -16 | 25.40 | 1 | 0.38 | 0.015 | 0.38 | 0.015 | 0.38 | 0.015 |
| -20 | 31.75 | 1-1/4 | 0.48 | 0.019 | - | - | - | - |
| -24 | 38.10 | 1-1/2 | 0.57 | 0.023 | 0.57 | 0.023 | - | - |
1 Tolerance without a time limit:
- 5% of the tube wall thickness (T).
NOTE: The damaged pipe can stay in operation with no time limit.
| OD DASH | WALL THICKNESS T | TYPE B (with material removal) | ||||||
|---|---|---|---|---|---|---|---|---|
| -4 | 0.41 | 0.016 | 0.02 | 0.001 | - | - | 0.02 | 0.001 |
| -4 | 0.89 | 0.035 | - | - | 0.04 | 0.002 | - | - |
| -6 | 0.51 | 0.020 | 0.03 | 0.001 | - | - | 0.03 | 0.001 |
| -6 | 0.89 | 0.035 | - | - | 0.04 | 0.002 | - | - |
| -8 | 0.66 | 0.026 | 0.03 | 0.001 | - | - | 0.03 | 0.001 |
| -8 | 0.89 | 0.035 | - | - | 0.04 | 0.002 | - | - |
| -10 | 0.84 | 0.033 | 0.04 | 0.002 | - | - | 0.04 | 0.002 |
| -10 | 0.89 | 0.035 | - | - | 0.04 | 0.002 | - | - |
| -12 | 0.99 | 0.039 | 0.05 | 0.002 | - | - | 0.05 | 0.002 |
| -12 | 0.89 | 0.035 | - | - | 0.04 | 0.002 | - | - |
| -16 | 1.32 | 0.052 | 0.07 | 0.003 | - | - | 0.07 | 0.003 |
| -16 | 1.22 | 0.048 | - | - | 0.06 | 0.002 | - | - |
| -20 | 0.61 | 0.024 | 0.03 | 0.001 | - | - | - | - |
| -24 | 0.61 | 0.024 | 0.03 | 0.001 | - | - | - | - |
| -24 | 0.89 | 0.035 | - | - | 0.04 | 0.002 | - | - |
- The damage must not be more than 20% of the tube wall thickness (T).
- The damage must be in the straight area of the pipe, not in a bend.
- You must replace the damaged pipe before 750 FH, 750 flight cycles or 4 months, whichever comes first.
| OD DASH | WALL THICKNESS T | TYPE B (with material removal) | ||||||
|---|---|---|---|---|---|---|---|---|
| -4 | 0.41 | 0.016 | 0.08 | 0.003 | - | - | 0.08 | 0.003 |
| -4 | 0.89 | 0.035 | - | - | 0.18 | 0.007 | - | - |
| -6 | 0.51 | 0.020 | 0.10 | 0.004 | - | - | 0.10 | 0.004 |
| -6 | 0.89 | 0.035 | - | - | 0.18 | 0.007 | - | - |
| -8 | 0.66 | 0.026 | 0.13 | 0.005 | - | - | 0.13 | 0.005 |
| -8 | 0.89 | 0.035 | - | - | 0.18 | 0.007 | - | - |
| -10 | 0.84 | 0.033 | 0.17 | 0.007 | - | - | 0.17 | 0.007 |
| -10 | 0.89 | 0.035 | - | - | 0.18 | 0.007 | - | - |
| -12 | 0.99 | 0.039 | 0.20 | 0.008 | - | - | 0.20 | 0.008 |
| -12 | 0.89 | 0.035 | - | - | 0.18 | 0.007 | - | - |
| -16 | 1.32 | 0.052 | 0.26 | 0.010 | - | - | 0.26 | 0.010 |
| -16 | 1.22 | 0.048 | - | - | 0.24 | 0.010 | - | - |
| -20 | 0.61 | 0.024 | 0.12 | 0.005 | - | - | - | - |
| -24 | 0.61 | 0.024 | 0.12 | 0.005 | - | - | - | - |
| -24 | 0.89 | 0.035 | - | - | 0.18 | 0.007 | - | - |
(a) Clean with the Textile-Lint free Cotton - (Material No.14SBA1) and a Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(b) Rub with the Abrasive-- Scotch Brite Pads - (Material No.14FAB1) .
(c) Clean with the Textile-Lint free Cotton - (Material No.14SBA1) and a Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(d) Apply protection:
1 For aluminum alloy (6061-T6) tubes:
- Apply chromate treatment (alodine) Surface Pretreatment-Light Alloys Chemical Conversion Yellow - (Material No.10ABC1) .
- Complete the protection with Primer Polyurethane Paint_- Corrosion Inhibiting Structure (Material No.04EAC2) .
- Apply finish paint Top Coat Polyurethane_- - External Structure (Material No.04JAA3) .
- Apply protection with Wash Primer_- - Structure (Material No.04CMA2) .
- Complete the protection with Primer Polyurethane Paint_- Corrosion Inhibiting Structure (Material No.04EAC2) .
C. Special Case of ASNA3760 Union and ASNA3759 Sleeve
(1) These Harrison fittings are roller-swaged on titanium-alloy hydraulic tubes (Ref. AMM TASK 20-23-11-300-005).
(2) ASNA3760 union:
No cracks are permitted on the ASNA3760 union, with or without leaks.
If the union has a crack, you must replace it.
(3) ASNA3759 sleeve:
A crack behind the sleeve shoulder (skirt area, i.e. nut side) is permitted if there is no leak.
Then, it is not necessary to replace the sleeve.
Subtask 20-23-11-210-064-A ** ON A/C NOT FOR ALL (1) These Harrison fittings are roller-swaged on titanium-alloy hydraulic tubes (Ref. AMM TASK 20-23-11-300-005).
(2) ASNA3760 union:
No cracks are permitted on the ASNA3760 union, with or without leaks.
If the union has a crack, you must replace it.
(3) ASNA3759 sleeve:
A crack behind the sleeve shoulder (skirt area, i.e. nut side) is permitted if there is no leak.
Then, it is not necessary to replace the sleeve.
D. Special Damage Criteria of Fire Protection Sleeves on Pipes in the Pylon Area
(a) Measure the length (L) and the depth (D) of the damage.
(b) If the damage dimensions are less than the limits given in the table that follows, the pipe can stay in operation.
(c) If the dimensions are less than the permitted limits but the cut or slit is in the outer bend of the pipe:
(2) Gouge or abrasion damage on a fire protection sleeve (for Type 1 and Type 2)
(a) Measure the depth (D), the length (L) and the width (W) of the damage.
(b) Make sure that the damage dimensions are less than the limits given in the table that follows. Do the applicable action if necessary.
(c) Repair the pipe if necessary (Ref. AMM TASK 20-23-11-300-802).
(d) Replace the pipe if one or more of these condition(s) is (are) applicable:
Subtask 20-23-11-210-064-B ** ON A/C NOT FOR ALL NOTE: There are two types of fire protection sleeves on rigid hydraulic pipes:
(1) Cut or slit damage on a fire protection sleeve (applicable for Type 1 and Type 2) - Type 1: "silicone sleeve", thickness of 3 mm (0.12 in.), refer to F00030530
- Type 2: "silicone sleeve + braided fiberglass", thickness of 5 mm (0.20 in.), refer to F00032201
- D290-10052-012-00 = Type 1
- D290-10052-018-00 = Type 1
- D290-10102-013-00 = Type 1
- D290-10104-000-00 = Type 1
- D004-10400-001-00 = Type 2
- D290-10052-013-00 = Type 2
- D290-10052-014-00 = Type 2
- D290-10052-016-00 = Type 2
- D290-10052-020-00 = Type 2
- D290-10102-012-00 = Type 2
- D290-10102-014-00 = Type 2
- D290-10558-000-00 = Type 2
- D290-10560-000-00 = Type 2
- D290-18002-000-00 = Type 2.
(a) Measure the length (L) and the depth (D) of the damage.
(b) If the damage dimensions are less than the limits given in the table that follows, the pipe can stay in operation.
| DAMAGE | PERMITTED LIMITS |
|---|---|
| Axial cut or slit | D <= 0.8 mm (0.03 in.) L <= 76 mm (3 in.) |
| Radial cut or slit | D <= 0.8 mm (0.03 in.) L <= 6.3 mm (0.25 in.) |
- You must regularly (every month) monitor the damage for all changes of size.
NOTE: A cut in the silicone material can become larger. This can occur if it is in an area with force such as the outer bend of the pipe.
(d) If one damage dimension is more than the permitted limits, you must replace the pipe. (2) Gouge or abrasion damage on a fire protection sleeve (for Type 1 and Type 2)
(a) Measure the depth (D), the length (L) and the width (W) of the damage.
(b) Make sure that the damage dimensions are less than the limits given in the table that follows. Do the applicable action if necessary.
| DAMAGE DIMENSION | ACTION |
|---|---|
| D <= 0.8 mm (0.03 in.) L <= 25.4 mm (1 in.) W <= 6.3 mm (0.25 in.) | The pipe can stay in operation. |
| For pipes with Type 1 fire protection sleeve only: 0.8 mm (0.03 in.) < D <= 1.5 mm (0.06 in.) L <= 25.4 mm (1 in.) W <= 6.3 mm (0.25 in.) | Repair the pipe. |
| For pipes with Type 2 fire protection sleeve only: D = You can see the braided-fiberglass protection sleeve but it is not damaged L <= 25.4 mm (1 in.) W <= 6.3 mm (0.25 in.) | Repair the pipe. |
(d) Replace the pipe if one or more of these condition(s) is (are) applicable:
- One of the dimensions (L or W) is more than the permitted limits (for pipes with Type 1 and Type 2 fire protection sleeve) or
- The depth (D) is more than 1.5 mm (0.06 in.) (for pipes with Type 1 fire protection sleeve only) or
- The braided-fiberglass protection sleeve (for pipes with Type 2 fire protection sleeve only) is damaged or
- The fire protection sleeve is damaged with damage on the pipe.
D. Special Damage Criteria of Fire Protection Sleeves on Pipes in the Pylon Area
(a) Measure the length (L) and the depth (D) of the damage.
(b) If the damage dimensions are less than the limits given in the table that follows, the pipe can stay in operation.
(c) If the dimensions are less than the permitted limits but the cut or slit is in the outer bend of the pipe:
(2) Gouge or abrasion damage on a fire protection sleeve (for Type 1 and Type 2)
(a) Measure the depth (D), the length (L) and the width (W) of the damage.
(b) Make sure that the damage dimensions are less than the limits given in the table that follows. Do the applicable action if necessary.
(c) Repair the pipe if necessary (Ref. AMM TASK 20-23-11-300-802).
(d) Replace the pipe if one or more of these condition(s) is (are) applicable:
Subtask 20-23-11-210-062-A NOTE: There are two types of fire protection sleeves on rigid hydraulic pipes:
(1) Cut or slit damage on a fire protection sleeve (applicable for Type 1 and Type 2) - Type 1: "silicone sleeve", thickness of 3 mm (0.12 in.), refer to F00030530
- Type 2: "silicone sleeve + braided fiberglass", thickness of 5 mm (0.20 in.), refer to F00032201
- D290-10052-012-00 = Type 1
- D290-10052-018-00 = Type 1
- D290-10102-013-00 = Type 1
- D290-10104-000-00 = Type 1
- D004-10400-001-00 = Type 2
- D290-10052-013-00 = Type 2
- D290-10052-014-00 = Type 2
- D290-10052-016-00 = Type 2
- D290-10052-020-00 = Type 2
- D290-10102-012-00 = Type 2
- D290-10102-014-00 = Type 2
- D290-10552-000-00 = Type 2
- D290-10560-000-00 = Type 2
- D290-18002-000-00 = Type 2.
(a) Measure the length (L) and the depth (D) of the damage.
(b) If the damage dimensions are less than the limits given in the table that follows, the pipe can stay in operation.
| DAMAGE | PERMITTED LIMITS |
|---|---|
| Axial cut or slit | D <= 0.8 mm (0.03 in.) L <= 76 mm (3 in.) |
| Radial cut or slit | D <= 0.8 mm (0.03 in.) L <= 6.3 mm (0.25 in.) |
- You must regularly (every month) monitor the damage for all changes of size.
NOTE: A cut in the silicone material can become larger. This can occur if it is in an area with force such as the outer bend of the pipe.
(d) If one damage dimension is more than the permitted limits, you must replace the pipe.(2) Gouge or abrasion damage on a fire protection sleeve (for Type 1 and Type 2)
(a) Measure the depth (D), the length (L) and the width (W) of the damage.
(b) Make sure that the damage dimensions are less than the limits given in the table that follows. Do the applicable action if necessary.
| DAMAGE DIMENSION | ACTION |
|---|---|
| D <= 0.8 mm (0.03 in.) L <= 25.4 mm (1 in.) W <= 6.3 mm (0.25 in.) | The pipe can stay in service. |
| For pipes with Type 1 fire protection sleeve only: 0.8 mm (0.03 in.) < D <= 1.5 mm (0.06 in.) L <= 25.4 mm (1 in.) W <= 6.3 mm (0.25 in.) | Repair the pipe. |
| For pipes with Type 2 fire protection sleeve only: D = You can see the braided-fiberglass protection sleeve but it is not damaged L <= 25.4 mm (1 in.) W <= 6.3 mm (0.25 in.) | Repair the pipe. |
(d) Replace the pipe if one or more of these condition(s) is (are) applicable:
- One of the dimensions (L or W) is more than the permitted limits (for pipes with Type 1 and Type 2 fire-protection sleeve) or
- The depth (D) is more than 1.5 mm (0.06 in.) (for pipes with Type 1 fire-protection sleeve only) or
- The braided-fiberglass protection sleeve (for pipes with Type 2 fire-protection sleeve only) is damaged or
- The fire protection sleeve is damaged with damage on the pipe.
E. Special Case for Hydraulic Pipe Bushes at RIB5
Bush Wear Limits on Pipe at RIB5 ** ON A/C NOT FOR ALL
Bush Wear Limits on Pipe at RIB5 ** ON A/C NOT FOR ALL
(1) Use Non Aqueous Cleaner-General - - (Material No.08BAA9) and Textile-Lint free Cotton - (Material No.14SBA1) to clean the pipe and remove the sealant, if necessary.
(2) Remove the half-cleat at RIB5.
(3) Visually examine the pipe bush wear:
(a) If the wear on the bush is more than 0.89 mm (0.0350 in.), remove the pipe bush and replace the hydraulic tube (Ref. AMM TASK 20-23-11-911-001).
(b) If the wear on the bush is less than 0.89 mm (0.0350 in.):
Bush Wear Limits on Pipe at RIB5 ** ON A/C NOT FOR ALL Bush Wear Limits on Pipe at RIB5 ** ON A/C NOT FOR ALL (2) Remove the half-cleat at RIB5.
(3) Visually examine the pipe bush wear:
(a) If the wear on the bush is more than 0.89 mm (0.0350 in.), remove the pipe bush and replace the hydraulic tube (Ref. AMM TASK 20-23-11-911-001).
(b) If the wear on the bush is less than 0.89 mm (0.0350 in.):
- Apply the Silicone Adhesive Sealant-General Purpose One part legacy (Material No.06CMD9) and install the half-cleat, or
- Install the half-cleat and do an inspection of the pipe bush again at the next maintenance visit, before 36 months, 12000 FH or 8000 flight cycles, whichever occurs first.