Blend Repair of the High Pressure Compressor (HPC) Rotor Blades Stages 1-9 [CFMB]

TASK 72-31-00-300-004-A
Blend Repair of the High Pressure Compressor (HPC) Rotor Blades Stages 1-9

ZONE: 400

1. Reason for the Job
This TASK is the blend repair of the HPC rotor blades with a borescope blend tool.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 1M(3 FT)
No specific	AR	BORESCOPE - BLENDING
No specific	1	VIDEO - MONITOR
No specific	1	VIDEO CAMERA
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 20 and 15 lbf.in (0.23 and 0.17 m.daN )
No specific	Torque wrench: range to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )
No specific	Torque wrench: range to between 85 and 75 lbf.in (0.96 and 0.85 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2101)	graphite grease
(Material No.CP2619)	Never Seez-Pure Nickel, Special
(Material No.CP8001)	lockwire 0.032 in. (0.8 mm) dia.
(Material No.CP8002)	lockwire 0.032 in. (0.8 mm) dia

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-710-006-B	Minimum Idle Check
TASK 71-13-00-010-040-B	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-B	Closing of the Fan Cowl Doors
TASK 72-63-00-400-002-A	Installation of the Handcranking Drive Cover
TASK 78-30-00-081-041-B	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-B	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-B	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-B	Closing of the Thrust Reverser Doors
TASK 80-11-10-400-002-A	Installation of the Pneumatic Starter
HPC Blade Borescope Blending Tool
Blend Area Example
Borescope Blend Tool Tip Selection/Blend Tip Installation
Compressor Blades Inspection Areas

3. Job Set-up
Subtask 72-31-00-941-057-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).

Subtask 72-31-00-010-064-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(2) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(3) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(4) Put an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 72-31-00-040-055-A ** ON A/C NOT FOR ALL

C. Make the thrust reverser unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 72-31-00-010-065-A ** ON A/C NOT FOR ALL

D. Open the thrust reverser doors: (Ref. AMM TASK 78-36-00-010-040)
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR

4. Procedure
Subtask 72-31-00-220-050-A ** ON A/C NOT FOR ALL

A. Blending Limits

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! INSPECT/CHECK ! MAXIMUM !

! ! BLENDABLE LIMITS !

!------------------------------------------------------------------------------

! (1) Tears, nicks, dents, missing material ! !

! and erosion on the leading and trailing ! !

! edge of stages 1-4 compressor blade found ! !

! in Dim. B of the airfoil. ! !

!------------------------------------------------------------------------------

! NOTE: Blend repair of the leading and trailing edges can not extend into !

! the airfoil root fillet (R). !

! NOTE: More than one blend in the same area is permitted if the total !

! material removed from the initial contour is not more than the limit !

! that can be repaired. !

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! (a) No maximum number of blended damage ! Maximum depth is 0.080 in. !

! areas. ! (2.03 mm) after you blend. !

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! (2) Tears, nicks, dents, missing material ! !

! and erosion on the leading and trailing ! !

! edge of stages 1-4 compressor blade ! !

! found in Dim. A. ! !

-------------------------------------------------------------------------------

! NOTE: More than one blend in the same area is permitted if the total !

! material removed from the initial contour is not more than the limit !

! that can be repaired. !

-------------------------------------------------------------------------------

! (a) No maximum number of blended damage ! Maximum blended area is 0.30 !

! areas. ! x 0.30 in. (7.6 x 7.6 mm) !

! ! after you blend. !

-------------------------------------------------------------------------------

! (b) No maximum number of dents. ! Maximum depth is 0.080 in. !

! ! (2.03 mm). !

! ! Maximum deflection from !

! ! initial contour is 0.080 in. !

! ! (2.03 mm). !

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! (c) No maximum number of missing tip ! (a) Individual blades with !

! corners. ! missing material greater than !

! ! 0.30x0.30 in. (7.6 x 7.6 mm) !

! ! missing tip corners after !

! ! blend on both leading and !

! ! trailing edges are not !

! ! permitted. !

! ! (b) Any number of blades for !

! ! each stage 1 thru 4, up to !

! ! 0.30x0.30 in. (7.6 x 7.6 mm) !

! ! missing tip corners after !

! ! blend if the downstream !

! ! damage is serviceable. !

! ! (c) For stage 2, a maximum of !

! ! 4 blades up to 0.40x0.040 in. !

! ! (10.2x10.2 mm) and 46 blades !

! ! up to !

! ! 0.30x0.30 in. (7.6 x 7.6 mm) !

! ! missing tip corners after !

! ! blend for total of 50 blades !

! ! with missing tip corners. !

! ! (d) For stage 3, a maximum of !

! ! 5 blades up to 0.40x0.040 in. !

! ! (10.2x10.2 mm) and 51 blades !

! ! up to !

! ! 0.30x0.30 in. (7.6 x 7.6 mm) !

! ! missing tip corners after !

! ! blend for total of 56 blades !

! ! with missing tip corners. !

! ! (e) For stage 4, a maximum of !

! ! 6 blades up to 0.40x0.040 in. !

! ! (10.2x10.2 mm) and 57 blades !

! ! up to !

! ! 0.30x0.30 in. (7.6 x 7.6 mm) !

! ! missing tip corners after !

! ! blend for total of 63 blades !

! ! with missing tip corners. !

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! (3) Tears, nicks, dents, missing material ! !

! and erosion on the leading and trailing ! !

! edge of stages 5-9 compressor blade ! !

! found in dimension Dim. B of the airfoil! !

-------------------------------------------------------------------------------

! (a) No maximum number of blended damage ! Maximum blendable limits: !

! areas. ! 0.080 in. (2.03 mm) max !

! ! depth after you blend. !

-------------------------------------------------------------------------------

! (4) Tears, nicks, dents, missing material ! !

! and erosion on the leading and trailing ! !

! edge of stages 5-9 compressor blade ! !

! found in area Dim. A. ! !

-------------------------------------------------------------------------------

! (a) Up to 20 percent of the blades in each! Maximum area is 0.20 x 0.20 !

! stage can have tears, nicks, erosion ! in. (5.1 x 5.1 mm) after you !

! and material that is not there. ! blend. !

-------------------------------------------------------------------------------

! (b) No maximum number of dents. ! Maximum depth is 0.080 in. !

! ! (2.03 mm). !

! ! Maximum deflection from !

! ! initial contour is 0.080 in. !

! ! (2.03 mm). !

-------------------------------------------------------------------------------

! (5) Tears, nicks, dents, missing material ! Maximum blend limit 0.060 in. !

! and erosion on the leading and trailing !(1.52 mm) max depth after you !

! edge of stages 1-9 compressor blade you ! blend. !

! find in the lower 25% of the airfoil. ! !

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! (a) No maximum number of blended damage ! !

! areas. ! !

-------------------------------------------------------------------------------

! (b) Blend repair of the leading and ! !

! trailing edges can not go into the airfoil ! !

! root fillet (R). ! !

-------------------------------------------------------------------------------

Subtask 72-31-00-320-053-A ** ON A/C NOT FOR ALL

B. Perform Blade Blending

NOTE: Equivalent substitutes for the BORESCOPE - BLENDING and VIDEO CAMERA and VIDEO - MONITOR are not permitted unless approved by CFMI.

(1) Measure the damaged area as follows:

NOTE: Do not install or remove the tool tip from the drive shaft head with the drive shaft head in the zero degree position. If you remove the tool tip with the drive shaft head in the zero degree position, the drive belt will disengage.

(a) Put the drive shaft head (2) in the 90 degree position. Install the measuring grid tip (5) onto the drive shaft head (2) and tighten the lockscrew. This will prevent damage to the rotor blades or the blend tool.
(b) Put the measuring grid tip (5) in the zero degree position and put the tool (4) into the borescope port.
(c) Monitor the measuring grid tip (5), and position the drive shaft head (2) to the 90 degree position.
(d) Put the measuring grid tip (5) near the HPC blade damage area.

NOTE: Each square on the grid is 0.039 x 0.039 in. (1.00 x 1.00 mm).
The overall grid size is 0.197 x 0.197 in. (5.00 x 5.00 mm).

(e) Write down the damage result such as defect size and location.
(f) Compare the recorded blade damage against the permitted blend limits.

NOTE: Make sure the blade damage is less than the permitted blend limits.

(g) If the damage is less than permitted limits, find the length of the blend necessary to keep the minimum blend radius.
(h) Calculate the minimum blend radius at two times the depth of the defect, or one time on both sides of the center of the blade defect.
(i) Put the drive shaft head (2) in the zero degree position, and remove the tool from the borescope port.
(j) Put the drive shaft head (2) in the 90 degree position. Loosen the lockscrew, and remove the measuring grid tip (5) from the drive shaft head.
(2) Blade blending procedure

NOTE: Do not blend airfoil root radius (R).

NOTE: When blending rotor blades, blend in a radial direction in relation to the engine centerline. Avoid removing metal from leading and trailing edges of airfoil sections in such a way that the edges become thin or sharp; blend so as to maintain approximately the original contour.

NOTE: The finish on the blended area must be as close to the original finish as possible.

(a) Put the drive shaft head (2) in the 90 degree position, and use the applicable grind tip to blend the HPC stage damaged.

NOTE: Use longer blend tool tips for the forward blades, and shorter blend tool tips for the aft blades.

(b) Apply the light source to the blend tool.

NOTE: Do not install or remove a tool tip from the drive shaft head with the drive shaft head in the zero degree position. If you remove the tool tip with the drive shaft head in the zero degree position, the drive belt will disengage.

NOTE: Make sure the blend tip is pointed away from the operator in the 90 degree position. Start the drive motor and make sure the tip rotates in the clockwise direction. If the direction of rotation is counter clockwise, check the drive belt for possible twisted installation.

(3) Put the blend tool tip in the zero degree position. Put the blend tool tip into the compressor, through the borescope access port.
(4) Put the primary blade edge grinding tip (1) in the borescope port, view the tool tip and move the tool tip from the zero degree to the 90 degree position.
(5) Put the primary blade edge grinding tip (1) near the HPC blade defect.
(6) Align the blend tool tip with the blade defect and check for correct movement across the total length of the area to be blended.

NOTE: Do not start the drive motor (14) at this time.

NOTE: Make sure the blend tool tip correctly touches across the total area to be blended.

(7) Use the primary blade edge grinding tip (1) and mark the two sides of the blade defect.

NOTE: The minimum blend radius should be two times the depth of the defect, or one time on both sides of the center of the blade defect.

(8) Start the drive motor (14) and apply pressure to the grid tip (1) at the defect area.
(a) After sufficient practice with the grind tip (1) on the blade leading edge surface, turn on the motor using the on/off switch (16) and use the motor speed control (6) to increase speed.

NOTE: If the grind tip (1) does not turn freely, apply less pressure to the blade edge surface.

(9) During blending, make sure that you put a contour on the edge of the blade and remove the sharp edges.
(10) Stop the drive motor (14).
(11) Put the grind tip (1) in the zero degree position.
(12) Remove the grind tip (1) from the borescope access port.
(13) Put the grind tip (1) in the 90 degree position.
(14) Loosen the lockscrew and remove the grind tip (1) from the drive shaft head (2).

(15) Install the polishing ball tip (4) onto the drive shaft head (2) and tighten the lockscrew. This will prevent damage to the rotor blades or the blend tool.

(16) Put the polishing ball tip (4) in the zero degree position and put it into the borescope access port. Next, put the drive shaft head (2) in the 90 degree position.
(17) Polish the blended surface and stop the drive motor (14).
(18) Put the polishing ball tip (4) in the zero degree position and remove from the borescope port.
(19) Use the standard borescope probe 1 configuration (magnified 1 : 1 at 7 in. (177 mm)) and inspect the blended blades to make sure you removed all the defect.

5. Close-up
Subtask 72-31-00-410-066-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Install the stage 1 thru 5 borescope plugs (S2 thru S6) as follows:
(a) Apply graphite grease (Material No.CP2101) or CP2619Never Seez-Pure Nickel, Special to the threads and pressure face of the borescope plugs.
(b) Install the borescope plug in the borescope port. Tighten the borescope plug by hand.
(c) TORQUE the borescope plugs to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(d) Wirelock the borescope plugs. Use CP8001lockwire 0.032 in. (0.8 mm) dia. or CP8002lockwire 0.032 in. (0.8 mm) dia.
(2) Install the stage 6, 7 and 8 borescope plugs (S7, S8 and S9) as follows:

CAUTION: MAKE SURE YOU FULLY SCREW THE INNER CAP IN. IF NOT FULLY SCREWED IN, THE INNER CAP OF THE BORESCOPE PLUG WILL DEFLECT THE COMPRESSOR REAR CASE AS THE OUTER CAP IS TIGHTENED. THIS WILL CAUSE BINDING OF THE COMPRESSOR ROTOR.

(a) Make sure the borescope port is open. Insert the 0.37 in. (9.40 mm) diameter tapered rod in the borescope port.
(b) Apply graphite grease (Material No.CP2101) or CP2619Never Seez-Pure Nickel, Special to the threads and pressure face of the borescope plugs.
(c) Put the plug in the correct borescope port and tighten the inner plug by hand. Use the outer plug to turn the inner plug.
(d) TORQUE the inner plug to between 85 and 75 lbf.in (0.96 and 0.85 m.daN )

. Loosen half a turn and RETORQUE to between 20 and 15 lbf.in (0.23 and 0.17 m.daN )

more than the running torque.
(e) Compress the plug spring and tighten the outer plug by hand.

NOTE: If the inner plug is correctly installed and the threads are not damaged, you can install the outer plug by hand. If the outer plug cannot be fully installed by hand, the inner plug is not correctly installed. Remove the plug and repeat steps (c), (d) and (e).

(f) TORQUE the outer plug to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )

(g) Wirelock all 3 outer plugs together with CP8001lockwire 0.032 in. (0.8 mm) dia. or CP8002lockwire 0.032 in. (0.8 mm) dia.
(3) Remove the tool used to rotate the core.
(a) Remove the 856A1488 MOTOR, DRIVE - CORE ENGINE ROTATION (856A1488P01 or P02) from the starter pad of the AGB if installed.
(b) Install the handcranking drive pad cover (Ref. AMM TASK 72-63-00-400-002) if removed.
(c) Install the starter (Ref. AMM TASK 80-11-10-400-002) if removed.
(4) Make sure that the work area is clean and clear of tools and other items.
(5) Close the thrust reverser doors: (Ref. AMM TASK 78-36-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR.

Subtask 72-31-00-440-055-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 72-31-00-710-051-A ** ON A/C NOT FOR ALL

C. Test

CAUTION: DO NOT OPERATE THE ENGINE WITHOUT A CORRECTLY INSTALLED COVER ON THE N2 HANDCRANKING DRIVE PAD. IF THE COVER IS NOT INSTALLED CORRECTLY, THE ENGINE CAN HAVE OIL LEAKAGE. THIS CAN CAUSE ENGINE FAILURE.

(1) Do a minimum idle check (Ref. AMM TASK 71-00-00-710-006) and check for leaks.

Subtask 72-31-00-410-067-A ** ON A/C NOT FOR ALL

D. Close Access
(1) Close the fan cowl doors: (Ref. AMM TASK 71-13-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 12:59:57 UTC