DOC AIRBUS | AMM A320FBorescope Blending of the High Pressure Compressor (HPC) Blades [CFML]
TASK 72-31-05-300-801-A
Borescope Blending of the High Pressure Compressor (HPC) Blades
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 72-31-05-941-050-A
Subtask 72-31-05-410-050-A
[Rev.10 from 2021]
2026.04.01 13:04:16 UTC
Borescope Blending of the High Pressure Compressor (HPC) Blades
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.
ZONE: 400
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 1M(3 FT) |
| No specific | AR | WARNING NOTICE(S) |
| 9471M44 | 1 | BORESCOPE BLEND TOOL |
| 956A1604 | 1 | BORESCOPE BLEND TOOL |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1) | |
| 437AL, 438AR, 451AL, 452AR | |
| FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2) | |
| 447AL, 448AR, 461AL, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-803-A | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-803-A | Closing of the Fan Cowl Doors |
| TASK 72-00-00-290-812-A | Engine Borescope Examination Preparation |
| TASK 72-00-00-820-802-A | Find the Zero Index Mark of the High Pressure Compressor (HPC) Rotor |
| TASK 72-00-00-820-803-A | Turning of the N2 Rotor |
| TASK 72-24-00-300-801-A | Borescope Plug D Removal and Installation Procedure |
| TASK 72-24-01-000-801-A | Removal of Segment Shrouds 1 thru 5 |
| TASK 72-24-01-400-801-A | Installation of Segment Shrouds 1 thru 5 |
| TASK 72-30-00-290-801-A | Borescope Inspection of the High Pressure Compressor Section |
| TASK 73-29-00-740-803-A | Idle Test (Menu Mode) |
| TASK 78-30-00-040-809-A | Deactivation of the Thrust Reverser System for Ground Maintenance |
| TASK 78-30-00-440-809-A | Reactivation of the Thrust Reverser System after Ground Maintenance |
| TASK 78-36-00-010-806-A | Opening of the Thrust Reverser Cowl Doors |
| TASK 78-36-00-410-806-A | Closing of the Thrust Reverser Cowl Doors |
Blend Repair Areas (Stages 1-10)Subtask 72-31-05-941-050-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 a 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 a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
Subtask 72-31-05-010-050-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 a 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 a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.
Subtask 72-31-05-040-050-A (1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.
C. Deactivation of the Thrust Reverser System for Maintenance
Subtask 72-31-05-010-051-A WARNING:
YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.
(1) Do the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-809). D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
4. Procedure(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
CAUTION:
MAKE SURE THE TEMPERATURE OF THE ENGINE AND OF THE AREAS ADJACENT TO THE BORESCOPE INSPECTION PORTS IS LESS THAN 150 °F (65.6 °C). DO NOT DO A BORESCOPE INSPECTION IF THE ADJACENT AREAS ARE TOO HOT TO TOUCH. DO THE BORESCOPE INSPECTION WHEN THE ENGINE TEMPERATURE IS LESS THAN 150 F(65.6 C). THIS WILL PREVENT DAMAGE TO THE BORESCOPE EQUIPMENT.
Subtask 72-31-05-320-050-A A. General
(1) This task gives instructions on blending with a borescope blending tool to remove nicks, dents and tears on the airfoil leading and trailing edges. Cracks are unserviceable and cannot be repaired with this task.
Subtask 72-31-05-320-051-A (1) This task gives instructions on blending with a borescope blending tool to remove nicks, dents and tears on the airfoil leading and trailing edges. Cracks are unserviceable and cannot be repaired with this task.
B. Setup the Equipments
(1) Make sure that the engine internal and external temperature is less than 150 deg.F (65.56 deg.C) before you insert the borescope into the engine.
(2) Setup the articulating 956A1604 BORESCOPE BLEND TOOL or the rigid 9471M44 BORESCOPE BLEND TOOL. The rigid 9471M44 BORESCOPE BLEND TOOL is recommended for all stages. However, the articulating 956A1604 BORESCOPE BLEND TOOL is recommended for stages 8-10 in the lower 50 percent span. Do a borescope blend to the blisks and blade airfoils as follows:
(b) Remove the borescope plugs (C thru M) from the HPC stator case assembly (Ref. AMM TASK 72-00-00-290-812), engine borescope examination preparation and as follows:
1 Tag the removed borescope plugs to identify its access port (C thru M).
Subtask 72-31-05-320-052-A (1) Make sure that the engine internal and external temperature is less than 150 deg.F (65.56 deg.C) before you insert the borescope into the engine.
(2) Setup the articulating 956A1604 BORESCOPE BLEND TOOL or the rigid 9471M44 BORESCOPE BLEND TOOL. The rigid 9471M44 BORESCOPE BLEND TOOL is recommended for all stages. However, the articulating 956A1604 BORESCOPE BLEND TOOL is recommended for stages 8-10 in the lower 50 percent span. Do a borescope blend to the blisks and blade airfoils as follows:
NOTE: Both borescope kits have "User Manuals" provided by the vendor.
(a) Install the N2 rotor turning equipment (Ref. AMM TASK 72-00-00-820-803). (b) Remove the borescope plugs (C thru M) from the HPC stator case assembly (Ref. AMM TASK 72-00-00-290-812), engine borescope examination preparation and as follows:
1 Tag the removed borescope plugs to identify its access port (C thru M).
C. Borescope Blend Procedure
(2) For stages 1 through 3, remove the shroud segment 2 (Ref. AMM TASK 72-24-01-000-801).
(3) To access the Stage 1 blisk borescope port (D) for blending damage (Ref. AMM TASK 72-24-00-300-801).
(4) Zero index the compressor rotor (Ref. AMM TASK 72-00-00-820-802).
(5) Find the dimensions of the necessary blend repair as follows:
(a) Installation of the measuring grid tip:
(c) Put the borescope drive shaft head into the compressor through the applicable borescope access port.
(d) Turn ON the borescope light source.
(e) Monitor the borescope image of the measuring grid tip while you move the 9471M44 BORESCOPE BLEND TOOL measuring grid tip from the zero-degree position to the 90-degree position.
(f) Monitor the borescope image of the measuring grid tip as follows:
1 Put the measuring grid tip near each blisk and blade airfoil damaged area. Use the grid tip to find and record the dimensions of the damage as follows:
b The maximum length of the damaged area.
c The location of the edges of the damaged area from the nearest edge of the airfoil.
(g) Find if a blend repair is permitted for each damaged area in the blisk and blade airfoil as follows:
1 Examine the blend repair limits for the blisk and blade airfoils.
2 Compare the data for the location of each damaged area to the blend repair limits.
3 For each damaged area that you are permitted to repair in a blisk and blade airfoil, calculate the minimum blend repair length as six times dimension A (the maximum depth of the damage).
5 Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position. Lock the tool spindle in place with the supplied lock pin and remove the measuring grid tip by turning Counter-Clockwise (CCW).
(6) Blend each blisk and blade airfoil damaged area that can be repaired.
or
(b) Install the blending tip into the tool drive shaft head.
1 If you use the 9471M44 BORESCOPE BLEND TOOL, put the drive shaft head in the 90-degree position.
2 If you use the 956A1604 BORESCOPE BLEND TOOL:
a Make sure the tool is in the zero-degree (straight) position.
b Use the blending tip tool (BKT-C) to loosen the collar from the collet end to insert the tip with threads facing out.
Tighten the collar so the collet end is grasping the tip.
c Utilizing the blending shaft grip tool (BKT-T), grasp the first thread of the threaded section of the shaft so it does not turn.
(c) Put the borescope drive shaft head into the compressor through the borescope access port.
(d) Turn on the borescope light source.
1 If you use the 9471M44 BORESCOPE BLEND TOOL, put the head in the 90-degree position.
(e) Monitor the borescope image of the blending tip while you put the blending tip near the blisk and blade damaged area.
(f) Put the blending tip in the location of the damaged area with the borescope kit motor off to find the minimum blend area as follows:
1 Use the blending tip to put two marks at three times dimension A (the maximum depth of the damage) on either side of the damage center.
b The distance between the two marks will be the minimum blend length of the repair.
(g) Move the blending tip.
(h) Make sure you know what the necessary movements are for the blending tip, that the borescope view is in the center of the blend area and that it is clear before you turn the motor on.
(i) After sufficient practice with the grind tool on the defect surface, do these steps:
1 Turn ON the drive motor using the ON/OFF switch.
2 Use the speed control to increase the speed.
3 Start the initial blend movements slowly and apply only light pressure to the blisk and blade damaged area.
5 Make sure that you put a contour on the edge of the compressor blade and remove sharp edges.
(k) Put the borescope drive shaft head in the zero-degree position and remove the blending tool from the borescope access port.
(l) Remove the blending tip from the drive shaft head:
2 If you use the 956A1604 BORESCOPE BLEND TOOL, make sure the drive shaft head is in the zero-degree (straight) position.
a Insert the blend tip into the blending tip tool and tighten the collar at the collet end to firmly hold the blend tip.
b Use the blending shaft grip tool to grasp the first thread of the threaded section of the shaft so it does not turn.
(7) Polish the blended compressor airfoil:
1 Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position.
b While the 9471M44 BORESCOPE BLEND TOOL polishing tip is in the 90-degree position, move the tool until it points away from you and briefly operate the motor as follows:
(b) Put the borescope drive shaft head into the compressor through the correct borescope access port.
(c) Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position.
(d) Turn the motor on and polish the surface of the blisks and blades repaired area with the polishing tip.
(e) Turn the motor off.
(f) Put the borescope drive shaft head in the zero-degree position and remove the polishing tip from the borescope access port.
(g) Do a borescope inspection of the blisk and blade airfoil blended areas to make sure all the defects have been removed and there are no sharp edges (Ref. AMM TASK 72-30-00-290-801).
(8) Turn OFF the borescope light source after you complete all of the repairs.
(9) Install the borescope plugs C thru M (Ref. AMM TASK 72-30-00-290-801).
(a) Install the borescope plug D (Ref. AMM TASK 72-24-00-300-801).
(10) Remove the N2 rotor turning equipment from the engine assembly (Ref. AMM TASK 72-00-00-820-803).
(11) Install the Accessory Gearbox (AGB) crank pad cover (Ref. AMM TASK 72-00-00-820-803).
(12) Do an inspection of the borescope plugs and the crank pad cover as follows:
(a) Make sure you installed the borescope plugs correctly (Ref. AMM TASK 72-30-00-290-801).
(b) Make sure you installed the crank pad cover correctly (Ref. AMM TASK 72-00-00-820-803).
(c) Make sure that there are no remaining borescope electrical leads or video cables on the engine assembly.
(d) Install shroud segment 2 (Ref. AMM TASK 72-24-01-400-801).
5. Close-upCAUTION:
INSTALL/REMOVE THE MEASURING GRID TIP WITH THE 9471M44 DRIVE SHAFT HEAD IN THE 90-DEGREE POSITION. IF YOU INSTALL/REMOVE THE TIP WITH THE DRIVE SHAFT HEAD IN A DIFFERENT POSITION, THE DRIVE BELT WILL DISENGAGE.
CAUTION:
REMOVE/INSTALL THE POLISHING TIP WITH THE 9471M44 DRIVE SHAFT HEAD IN THE 90-DEGREE POSITION. IF YOU INSTALL/REMOVE THE TIP WITH THE DRIVE SHAFT HEAD IN A DIFFERENT POSITION, THE DRIVE BELT WILL DISENGAGE.
(1) Do an inspection of the blisks and blades (Ref. AMM TASK 72-30-00-290-801) before you do the blend procedure. (2) For stages 1 through 3, remove the shroud segment 2 (Ref. AMM TASK 72-24-01-000-801).
(3) To access the Stage 1 blisk borescope port (D) for blending damage (Ref. AMM TASK 72-24-00-300-801).
(4) Zero index the compressor rotor (Ref. AMM TASK 72-00-00-820-802).
(5) Find the dimensions of the necessary blend repair as follows:
(a) Installation of the measuring grid tip:
CAUTION:
INSTALL THE MEASURING GRID TIP WITH THE 9471M44 DRIVE-SHAFT HEAD IN THE 90-DEGREE POSITION. IF YOU INSTALL THE TIP WITH THE DRIVE SHAFT HEAD IN A DIFFERENT POSITION, THE DRIVE BELT WILL DISENGAGE.
1 Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position. Lock the drive shaft head in place with the supplied lock pin. Install the measuring grid tip by hand tightening in the clockwise direction. NOTE: The 956A1604 BORESCOPE BLEND TOOL does not utilize any measurement tips. All measurements of damage must be made using the 9471M44 BORESCOPE BLEND TOOL and it's measurement tips.
(b) Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the zero-degree position. (c) Put the borescope drive shaft head into the compressor through the applicable borescope access port.
(d) Turn ON the borescope light source.
(e) Monitor the borescope image of the measuring grid tip while you move the 9471M44 BORESCOPE BLEND TOOL measuring grid tip from the zero-degree position to the 90-degree position.
(f) Monitor the borescope image of the measuring grid tip as follows:
1 Put the measuring grid tip near each blisk and blade airfoil damaged area. Use the grid tip to find and record the dimensions of the damage as follows:
NOTE: Each square of the measuring grid tip is 0.039 in. (0.99 mm) X 0.039 in. (0.99 mm).
a The maximum depth of the damaged area. b The maximum length of the damaged area.
c The location of the edges of the damaged area from the nearest edge of the airfoil.
(g) Find if a blend repair is permitted for each damaged area in the blisk and blade airfoil as follows:
1 Examine the blend repair limits for the blisk and blade airfoils.
2 Compare the data for the location of each damaged area to the blend repair limits.
3 For each damaged area that you are permitted to repair in a blisk and blade airfoil, calculate the minimum blend repair length as six times dimension A (the maximum depth of the damage).
CAUTION:
DO NOT DO MORE BLEND REPAIRS THAN THE MAXIMUM NUMBER PERMITTED PER STAGE. TO MAKE SURE THAT YOU OBEY THIS MAXIMUM NUMBER, COUNT ALL THE EXISTING BLENDS AND REFER TO THE "BLEND REPAIR AREAS" FIGURE.
a Adjust the damaged area to the center in the blend repair calculated. NOTE: Make sure the minimum blend area does not extend into area A.
Area A extends above the airfoil root fillet for all stages. Any cracks are unserviceable and cannot be blended.
4 Put the 9471M44 BORESCOPE BLEND TOOL head in the zero-degree position and remove the borescope shaft from the access port. Area A extends above the airfoil root fillet for all stages. Any cracks are unserviceable and cannot be blended.
5 Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position. Lock the tool spindle in place with the supplied lock pin and remove the measuring grid tip by turning Counter-Clockwise (CCW).
(6) Blend each blisk and blade airfoil damaged area that can be repaired.
NOTE: Use the figure
as a reference for the limits on the number of airfoils and adjacent airfoils that can be blended for each stage. Blends cannot extend into area A or DIM F and cannot be more than the depth limits. Any cracks are unserviceable and cannot be blended.
(a) Get the correct blending tip for the size and/or the shape of the blisk and blade damaged area. as a reference for the limits on the number of airfoils and adjacent airfoils that can be blended for each stage. Blends cannot extend into area A or DIM F and cannot be more than the depth limits. Any cracks are unserviceable and cannot be blended.
or
(b) Install the blending tip into the tool drive shaft head.
1 If you use the 9471M44 BORESCOPE BLEND TOOL, put the drive shaft head in the 90-degree position.
CAUTION:
INSTALL/REMOVE THE BLENDING TIP WITH THE 9471M44 DRIVE-SHAFT HEAD IN THE 90-DEGREE POSITION.
IF YOU INSTALL/REMOVE THE BLENDING TIP WITH THE DRIVE SHAFT HEAD IN A DIFFERENT POSITION, THE DRIVE BELT WILL DISENGAGE.
a Lock the tool spindle in place with the supplied lock pin. Install the grind tip by hand tightening in the Clockwise (CW) direction. - Make sure that you do not use the tips with a red base because these tips are not for this tool.
- Make sure that the tip turns in the CW direction.
NOTE: During operation, a tip that turns in the CW direction will be tightened by the force of the operation.
- If the tool tip turns in the CCW direction, the drive belt could be twisted. Use the tool manufacturer's instructions to repair the drive tool.
2 If you use the 956A1604 BORESCOPE BLEND TOOL:
a Make sure the tool is in the zero-degree (straight) position.
b Use the blending tip tool (BKT-C) to loosen the collar from the collet end to insert the tip with threads facing out.
Tighten the collar so the collet end is grasping the tip.
c Utilizing the blending shaft grip tool (BKT-T), grasp the first thread of the threaded section of the shaft so it does not turn.
CAUTION:
BE CAREFUL NOT TO BEND THE SHAFT WHEN YOU LOOSEN/INSTALL THE TIP OR HOLD THE THREADED SHAFT. DAMAGE TO THE SHAFT CAN CAUSE TOO MUCH VIBRATION.
d Tighten the blending tip. - Use the blending tip tool with tip inserted to hand tighten the blending tip onto the shaft until you can no longer screw the tip with the tool.
- Make sure that you only use tips with a red band at the base because they are specially made for this tool.
(c) Put the borescope drive shaft head into the compressor through the borescope access port.
(d) Turn on the borescope light source.
1 If you use the 9471M44 BORESCOPE BLEND TOOL, put the head in the 90-degree position.
(e) Monitor the borescope image of the blending tip while you put the blending tip near the blisk and blade damaged area.
(f) Put the blending tip in the location of the damaged area with the borescope kit motor off to find the minimum blend area as follows:
1 Use the blending tip to put two marks at three times dimension A (the maximum depth of the damage) on either side of the damage center.
NOTE: Only blend to a depth that is necessary to completely remove the defect.
a Make sure minimum blend length does not extend into area A or DIM F which extend above the root fillet. b The distance between the two marks will be the minimum blend length of the repair.
(g) Move the blending tip.
CAUTION:
DO NOT START THE MOTOR DURING THIS OPERATION. IF YOU DO, DAMAGE TO THE BLISK AND BLADES CAN OCCUR.
1 Move the blending tip to simulate the movement necessary to start the blend repair across the minimum blend repair length. (h) Make sure you know what the necessary movements are for the blending tip, that the borescope view is in the center of the blend area and that it is clear before you turn the motor on.
(i) After sufficient practice with the grind tool on the defect surface, do these steps:
1 Turn ON the drive motor using the ON/OFF switch.
2 Use the speed control to increase the speed.
3 Start the initial blend movements slowly and apply only light pressure to the blisk and blade damaged area.
NOTE: If the grind tool does not turn freely, apply less pressure to the blade edge.
4 When the blend movements become correct, increase the speed and pressure of the blending tip on the blisk and blade damage. 5 Make sure that you put a contour on the edge of the compressor blade and remove sharp edges.
NOTE: There are no polishing tips for the flexible 956A1604 BORESCOPE BLEND TOOL. Pay extra attention to make sure no sharp edges or high metal is left after the grinding operation.
(j) Turn off the drive motor. (k) Put the borescope drive shaft head in the zero-degree position and remove the blending tool from the borescope access port.
(l) Remove the blending tip from the drive shaft head:
CAUTION:
MAKE SURE THAT THE TOOL TIP IS ALWAYS INSTALLED (ALSO DURING THE STORAGE).
IF YOU DO NOT OBEY THIS INSTRUCTION, THE DRIVE BELT CAN BECOME DISENGAGED.
CAUTION:
INSTALL/REMOVE THE BLENDING TIP WITH THE 9471M44 DRIVE-SHAFT HEAD IN THE 90-DEGREE POSITION.
IF YOU INSTALL/REMOVE THE BLENDING TIP WITH THE DRIVE SHAFT HEAD IN A DIFFERENT POSITION, THE DRIVE BELT WILL DISENGAGE.
1 If you use the 9471M44 BORESCOPE BLEND TOOL, put the borescope drive shaft head in the 90-degree position. Lock the tool spindle in place with the supplied lock pin and turn the grinding tip CCW to remove it. 2 If you use the 956A1604 BORESCOPE BLEND TOOL, make sure the drive shaft head is in the zero-degree (straight) position.
a Insert the blend tip into the blending tip tool and tighten the collar at the collet end to firmly hold the blend tip.
b Use the blending shaft grip tool to grasp the first thread of the threaded section of the shaft so it does not turn.
CAUTION:
BE CAREFUL NOT TO BEND THE SHAFT WHEN YOU LOOSEN/INSTALL THE TIP OR HOLD THE THREADED SHAFT. DAMAGE TO THE SHAFT CAN CAUSE TOO MUCH VIBRATION.
c Loosen and remove the blending tip. - Use the blending tip tool to loosen and remove the blending tip.
(7) Polish the blended compressor airfoil:
NOTE: There are no polishing tips for the flexible 956A1604 BORESCOPE BLEND TOOL. The lower rotational speeds of the tool do not warrant the need for a polishing tip.
(a) Install the polishing tip into the drive shaft head. 1 Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position.
CAUTION:
INSTALL/REMOVE THE BLENDING TIP WITH THE 9471M44 DRIVE-SHAFT HEAD IN THE 90-DEGREE POSITION.
IF YOU INSTALL/REMOVE THE BLENDING TIP WITH THE DRIVE SHAFT HEAD IN A DIFFERENT POSITION, THE DRIVE BELT WILL DISENGAGE.
a Lock the tool spindle in place with the supplied lock pin. Install the polishing tip by hand and tighten it in the CW direction. b While the 9471M44 BORESCOPE BLEND TOOL polishing tip is in the 90-degree position, move the tool until it points away from you and briefly operate the motor as follows:
- Make sure that the tip turns in the CW direction.
NOTE: During operation, a tip that turns in the CW direction will be tightened by the force of the operation.
- If the tool tip turns in the CCW direction, the drive belt can be twisted. Use the tool manufacturer's instructions to repair the drive tool.
(b) Put the borescope drive shaft head into the compressor through the correct borescope access port.
(c) Put the 9471M44 BORESCOPE BLEND TOOL drive shaft head in the 90-degree position.
(d) Turn the motor on and polish the surface of the blisks and blades repaired area with the polishing tip.
(e) Turn the motor off.
(f) Put the borescope drive shaft head in the zero-degree position and remove the polishing tip from the borescope access port.
(g) Do a borescope inspection of the blisk and blade airfoil blended areas to make sure all the defects have been removed and there are no sharp edges (Ref. AMM TASK 72-30-00-290-801).
(8) Turn OFF the borescope light source after you complete all of the repairs.
(9) Install the borescope plugs C thru M (Ref. AMM TASK 72-30-00-290-801).
(a) Install the borescope plug D (Ref. AMM TASK 72-24-00-300-801).
(10) Remove the N2 rotor turning equipment from the engine assembly (Ref. AMM TASK 72-00-00-820-803).
(11) Install the Accessory Gearbox (AGB) crank pad cover (Ref. AMM TASK 72-00-00-820-803).
(12) Do an inspection of the borescope plugs and the crank pad cover as follows:
(a) Make sure you installed the borescope plugs correctly (Ref. AMM TASK 72-30-00-290-801).
(b) Make sure you installed the crank pad cover correctly (Ref. AMM TASK 72-00-00-820-803).
(c) Make sure that there are no remaining borescope electrical leads or video cables on the engine assembly.
(d) Install shroud segment 2 (Ref. AMM TASK 72-24-01-400-801).
Subtask 72-31-05-410-050-A
A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
Subtask 72-31-05-440-050-A (1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-809).
Subtask 72-31-05-410-051-A C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).
Subtask 72-31-05-710-050-A (1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).