DOC AIRBUS | AMM A320FBoro-Blend Repair of the Booster Blades Airfoils [CFML]
TASK 72-21-20-320-802-A
Boro-Blend Repair of the Booster Blades Airfoils
Self explanatory
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 72-21-20-941-062-A
Subtask 72-21-20-220-061-A
Subtask 72-21-20-410-054-A
[Rev.10 from 2021]
2026.04.01 02:51:44 UTC
Boro-Blend Repair of the Booster Blades Airfoils
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.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
CAUTION:
BEFORE YOU USE THE TOOL GIVEN IN THIS TASK, CONTACT SAFRAN AIRCRAFT ENGINES TO GET INFORMATION ABOUT THE APPLICABLE TOOL TRAINING. IF YOU DO NOT OBEY THIS INSTRUCTION, YOU CAN CAUSE DAMAGE TO THE EQUIPMENT.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | WARNING NOTICE(S) |
| 9471M44P01 | 1 | BORESCOPE BLEND TOOL |
| 956A6629 | 1 | SET, ENDOSCOPIC FPI CHEMICALS - BOOSTER, HPC, LPT BLAD |
| 956A6630 | 1 | SET, ENDOS. FPI AIR FILTRATION - BOOSTER, HPC, LPT BLA |
| 956A6631 | 1 | SET, ENDOSCOPIC FPI COMMON VISION - LP TURBINE BLADES |
| 956A6632 | 1 | SET, ENDOSCOPIC FPI CALIBRATION - BOOSTER, HPC, LPT BL |
| 956A6633 | 1 | SET, ENDOSCOPIC FPI - LP COMPRESSOR BLADES |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP2721) | abrasive cloth, silicon carbide |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 210 | CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD |
| 400 | POWER PLANT, NACELLES AND PYLONS |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 72-21-20-000-801-A | Removal of the Fan Blades |
| TASK 72-21-20-400-801-A | Installation of the Fan Blades |
Borescope Blend Tool InstallationSubtask 72-21-20-941-062-A
A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put the WARNING NOTICE(S) in position to tell persons not to operate:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put the WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
Subtask 72-21-20-020-053-A (1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put the WARNING NOTICE(S) in position to tell persons not to operate:
- The ENG/MODE selector switch
- The ENG/MASTER 1(2) control switch.
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put the WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
B. Removal of the Fan Rotor Blades
(1) Remove the fan rotor blades (Ref. AMM TASK 72-21-20-000-801).
(2) Make sure that you number each blade as you remove it, to make sure that each blade is installed in its initial position.
Subtask 72-21-20-480-050-A (1) Remove the fan rotor blades (Ref. AMM TASK 72-21-20-000-801).
(2) Make sure that you number each blade as you remove it, to make sure that each blade is installed in its initial position.
C. Tool Installation ( 9471M44P01 BORESCOPE BLEND TOOL)
(2) Install the blending tool on the drive shaft head (2).
(3) Tighten the lockscrew.
(4) Switch ON the light source to the blending tool.
(5) Position the blending tool to the 0-degree position and put the polishing ball tip (4) into the borescope port.
(6) Monitor the blending tool and position the drive shaft head (2) to the 90-degree position.
Subtask 72-21-20-080-050-A CAUTION:
DO NOT INSTALL OR REMOVE A TOOL TIP FROM THE HEAD WITH BEARING IF IT IS SET IN THE 0-DEGREE POSITION. IF YOU DO, THE DRIVE BELT WILL DISENGAGE.
(1) Position the drive shaft head (2) to the 90-degree position. (2) Install the blending tool on the drive shaft head (2).
(3) Tighten the lockscrew.
(4) Switch ON the light source to the blending tool.
(5) Position the blending tool to the 0-degree position and put the polishing ball tip (4) into the borescope port.
(6) Monitor the blending tool and position the drive shaft head (2) to the 90-degree position.
D. Tool Removal ( 9471M44P01 BORESCOPE BLEND TOOL)
(a) Remove the polishing ball tip (4) from the borescope port.
(2) Switch OFF the light source to the blending tool.
(3) Put the drive shaft head (2) to the 90-degree position.
(4) Loosen the lockscrew and remove the blending tool from the drive shaft head (2).
4. ProcedureCAUTION:
DO NOT INSTALL OR REMOVE A TOOL TIP FROM THE HEAD WITH BEARING IF IT IS SET IN THE 0-DEGREE POSITION. IF YOU DO, THE DRIVE BELT WILL DISENGAGE.
(1) Put the drive shaft head (2) to the 0-degree position. (a) Remove the polishing ball tip (4) from the borescope port.
(2) Switch OFF the light source to the blending tool.
(3) Put the drive shaft head (2) to the 90-degree position.
(4) Loosen the lockscrew and remove the blending tool from the drive shaft head (2).
Subtask 72-21-20-220-061-A
A. Dimensional Limits
Subtask 72-21-20-290-050-A NOTE: The dimensional data identified within this procedure was designed using millimeters as the base unit of measurement for the dimensional values. The conversion to inches is rounded to two additional decimal digits in relation to the conversion to millimeters. For the minimum dimensions, the converted values are rounded up. For the maximum dimensions, the converted values are rounded down. To avoid conversion errors, do not re-convert from inches to millimeters.
Table 801 - Dimensional Limits | DESCRIPTION | MINIMUM IN-PROCESS DIMENSION | MAXIMUM IN-PROCESS DIMENSION | MINIMUM FINISH DIMENSION | MAXIMUM FINISH DIMENSION | REFERENCE DIMENSION |
|---|---|---|---|---|---|
| A. Definition of the critical areas: (Area A) for all the stages and (Area N) for stage 3 only. | |||||
| Dim. H | | | | | 24 mm (0.94 in.) |
| Dim. Q | | | | | 16.53 mm (0.6508 in.) |
| Dim. T | | | | | 23.13 mm (0.9106 in.) |
| Dim. S | | | | | 32.5 mm (1.280 in.) |
| B. Blending limits of the leading and/or trailing edges for all the stages (Area B): | |||||
| Dim. P | | | | 1.0 mm (0.039 in.) | |
| Cumulative length of the blend repairs | | | | 14 mm (0.55 in.) | |
| Maximum cumulative depth of the chord reduction | | | | 1.0 mm (0.039 in.) | |
| Dim. K | | | | 10 mm (0.39 in.) | |
| C. Blend repair proportion on the leading and trailing edges: | |||||
| Dim. L | | | 6 x Dim.P | | |
| Radius R | | | 5 x Dim.P | | |
| Radius r | | | 2 x Dim.P | | |
B. Do a borescope inspection of the Low Pressure Compressor (LPC) blades as follows:
(1) Turn the fan rotor clockwise (aft looking forward).
(2) Mark the first blade that you inspect to make sure that all the blades are inspected.
(3) Count the number of the blades which are already blended.
(a) For each stage, a maximum of five blades can be blended on area B.
(b) Make sure that these conditions are respected after the repair.
(4) Find and measure the area to be repaired.
(a) Write down the inspection results:
(c) If the recorded inspection results are less than the permitted limits, find the length of the blend that is necessary to keep the minimum blend radius.
(d) Calculate the minimum blend radius at five times the depth of the defect.
Subtask 72-21-20-320-051-A (1) Turn the fan rotor clockwise (aft looking forward).
(2) Mark the first blade that you inspect to make sure that all the blades are inspected.
(3) Count the number of the blades which are already blended.
(a) For each stage, a maximum of five blades can be blended on area B.
(b) Make sure that these conditions are respected after the repair.
(4) Find and measure the area to be repaired.
(a) Write down the inspection results:
- the dimension for each blade.
- the location for each blade.
(c) If the recorded inspection results are less than the permitted limits, find the length of the blend that is necessary to keep the minimum blend radius.
(d) Calculate the minimum blend radius at five times the depth of the defect.
C. Boro-blend the trailing edges of the stage-2 LPC blades, the leading and trailing edges of the stage-3 LPC blades, and the leading edges of the stage-4 LPC blades.
(2) Put the grinding tip close to the repair area.
(3) Align the blending tool tip with the area to be blended.
(a) Check for the correct movement across the total length of the area.
(b) Do not start the drive motor (14) at this time.
(4) Use the primary blade edge grinding tip (1) and mark the two sides of the repair area.
(a) Refer to the blend limits.
(5) With the drive motor (14) off, apply pressure on the grind tool to blend the repair area.
(6) After sufficient practice with the grinding tip on the blade leading-edge surface, start the motor with the ON/OFF switch (16).
(a) Use the motor speed control (6) to increase the speed.
1 If the grinding tip does not turn freely, you must apply less pressure to the surface of the blade edge.
(7) Blend the area. Refer to Table 801 and
(a) After the blending, make sure that the contour and the thickness of the Leading Edge (LE) and the Trailing Edge (TE) are equal to their initial values.
(b) Remove a minimum of 0.025 mm (0.0010 in.) of base metal when you repair more than the depth of the defect, but do not blend more than the permitted limits (do not exceed Dim. P).
(c) When dimension D between two blend repairs is less than or equal to two times the depth of the repair, then blend the bottom of the two repairs tangentially.
(d) When dimension K is less than 10 mm (0.394 in.), then remove the shaded area shown on
1 Blend the repair with the blade tip.
(e) The maximum chord reduction permitted is dimension P on the leading or trailing edges. Refer to Table 801.
1 Use dimension P if you do two opposite blendings.
(8) Stop the drive motor (14).
(9) Remove the grinding tool. Refer to Para.3.D.
Subtask 72-21-20-320-052-A CAUTION:
DO NOT BLEND AREA A (ALL STAGES) AND AREA N (STAGE 3 ONLY).
IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO AREAS A AND N WILL OCCUR.
(1) Install the grinding tool. Refer to Para.3.C. CAUTION:
MAKE SURE THAT THE BLEND TIP IS POINTED AWAY FROM THE OPERATOR IN THE 90-DEGREE POSITION. START THE DRIVE MOTOR AND MAKE SURE THAT THE TIP TURNS IN THE CLOCKWISE DIRECTION. IF IT TURNS COUNTERCLOCKWISE, EXAMINE THE DRIVE BELT FOR POSSIBLE TWISTED INSTALLATION.
(a) Make sure that the tool turns in the clockwise direction. (2) Put the grinding tip close to the repair area.
(3) Align the blending tool tip with the area to be blended.
(a) Check for the correct movement across the total length of the area.
(b) Do not start the drive motor (14) at this time.
(4) Use the primary blade edge grinding tip (1) and mark the two sides of the repair area.
(a) Refer to the blend limits.
(5) With the drive motor (14) off, apply pressure on the grind tool to blend the repair area.
(6) After sufficient practice with the grinding tip on the blade leading-edge surface, start the motor with the ON/OFF switch (16).
(a) Use the motor speed control (6) to increase the speed.
1 If the grinding tip does not turn freely, you must apply less pressure to the surface of the blade edge.
(7) Blend the area. Refer to Table 801 and
(a) After the blending, make sure that the contour and the thickness of the Leading Edge (LE) and the Trailing Edge (TE) are equal to their initial values.
(b) Remove a minimum of 0.025 mm (0.0010 in.) of base metal when you repair more than the depth of the defect, but do not blend more than the permitted limits (do not exceed Dim. P).
(c) When dimension D between two blend repairs is less than or equal to two times the depth of the repair, then blend the bottom of the two repairs tangentially.
(d) When dimension K is less than 10 mm (0.394 in.), then remove the shaded area shown on
1 Blend the repair with the blade tip.
(e) The maximum chord reduction permitted is dimension P on the leading or trailing edges. Refer to Table 801.
1 Use dimension P if you do two opposite blendings.
(8) Stop the drive motor (14).
(9) Remove the grinding tool. Refer to Para.3.D.
D. Blend the leading edges of the stage-2 LPC blades through the booster inlet.
(1) (2) Refer to Para. 4.C.(7) for the blending instructions.
(3) Available alternative procedures. Do a hand blending with strips ofCP2721 abrasive cloth, silicon carbide SPM 704111 .
(4) Alternative procedureSPM 704112 .
(5) Alternative procedure. Use the boro-blending tool kit (part of the 9471M44P01 BORESCOPE BLEND TOOL). Refer to Para. 4.C.
(a) Make sure that you use the boro-blending tool kit (part of the 9471M44P01 BORESCOPE BLEND TOOL) through the booster inlet and not through a borescope hole.
Subtask 72-21-20-320-053-A (1) (2) Refer to Para. 4.C.(7) for the blending instructions.
(3) Available alternative procedures. Do a hand blending with strips of
(4) Alternative procedure
(5) Alternative procedure. Use the boro-blending tool kit (part of the 9471M44P01 BORESCOPE BLEND TOOL). Refer to Para. 4.C.
(a) Make sure that you use the boro-blending tool kit (part of the 9471M44P01 BORESCOPE BLEND TOOL) through the booster inlet and not through a borescope hole.
E. Do a polishing of the blade as given below:
(1) Install the polishing tool. Refer to Para.3.C.
(2) Put the ON/OFF switch (16) to ON to start the drive motor (14).
(3) Polish the blended surface.
(4) Stop the drive motor (14).
(5) Remove the polishing tool. Refer to Para.3.D.
Subtask 72-21-20-290-051-A (1) Install the polishing tool. Refer to Para.3.C.
(2) Put the ON/OFF switch (16) to ON to start the drive motor (14).
(3) Polish the blended surface.
(4) Stop the drive motor (14).
(5) Remove the polishing tool. Refer to Para.3.D.
F. Do a borescope inspection of the blended areas:
(1) Use the borescope kit (part of the 9471M44P01 BORESCOPE BLEND TOOL).
(2) Make sure that all the areas to be repaired are blended.
Subtask 72-21-20-230-051-A (1) Use the borescope kit (part of the 9471M44P01 BORESCOPE BLEND TOOL).
(2) Make sure that all the areas to be repaired are blended.
G. Do the Fluorescent Penetrant Inspection (FPI).
(1) Do the FPI (sensitivity, level 3) of the blade repaired with the 956A6629 SET, ENDOSCOPIC FPI CHEMICALS - BOOSTER, HPC, LPT BLAD, 956A6630 SET, ENDOS. FPI AIR FILTRATION - BOOSTER, HPC, LPT BLA, 956A6632 SET, ENDOSCOPIC FPI CALIBRATION - BOOSTER, HPC, LPT BL, 956A6633 SET, ENDOSCOPIC FPI - LP COMPRESSOR BLADES and 956A6631 SET, ENDOSCOPIC FPI COMMON VISION - LP TURBINE BLADESSPM 703221 FLUORESCENT PENETRANT INSPECTION-PORTABLE WATER-WASHABLE.
(a) Make sure that there are no cracks.
5. Close-up(1) Do the FPI (sensitivity, level 3) of the blade repaired with the 956A6629 SET, ENDOSCOPIC FPI CHEMICALS - BOOSTER, HPC, LPT BLAD, 956A6630 SET, ENDOS. FPI AIR FILTRATION - BOOSTER, HPC, LPT BLA, 956A6632 SET, ENDOSCOPIC FPI CALIBRATION - BOOSTER, HPC, LPT BL, 956A6633 SET, ENDOSCOPIC FPI - LP COMPRESSOR BLADES and 956A6631 SET, ENDOSCOPIC FPI COMMON VISION - LP TURBINE BLADES
(a) Make sure that there are no cracks.
Subtask 72-21-20-410-054-A
A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the fan rotor blades (Ref. AMM TASK 72-21-20-400-801).
Subtask 72-21-20-942-057-A (1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the fan rotor blades (Ref. AMM TASK 72-21-20-400-801).
B. Put the aircraft back to its initial configuration.
(1) Remove the WARNING NOTICE(S).
(1) Remove the WARNING NOTICE(S).