Determination of HPT Blade Tip Material Loss Using Tip Notches [CFML]

TASK 72-00-00-290-824-A
Determination of HPT Blade Tip Material Loss Using Tip Notches

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.

1. Reason for the Job
This section provides information to estimate the High Pressure Turbine (HPT) blade tip material loss using the blade tip notches.
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	1	BORESCOPE DIA 0.16 TO 0.24 IN (4 TO 6 MM) - FLEXIBLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 97 and 83 lbf.in (1.10 and 0.94 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2619)	Never Seez-Pure Nickel, Special

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

D. Referenced Information

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 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
HPT Stage Blade Tip Notch Location and Depth

3. Job Set-up
Subtask 72-00-00-941-258-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 WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(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 72-00-00-010-355-A

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 72-00-00-040-169-A

C. Deactivation of the Thrust Reverser System for Maintenance

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 maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 72-00-00-010-356-A

D. Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

4. Procedure
Subtask 72-00-00-290-147-A

A. Do the borescope examination preparation (Ref. AMM TASK 72-00-00-290-812).

Subtask 72-00-00-820-053-A

B. Manually or electrically motor the HPC rotor (Ref. AMM TASK 72-00-00-820-803).

Subtask 72-00-00-820-054-A

C. Do the N2 rotor find the zero index mark (Ref. AMM TASK 72-00-00-820-802).

Subtask 72-00-00-020-111-A

D. Do further preparation as follows:
(1) Remove the borescope plugs from port S. See sheet 1 of the figure.

HPT Stage Blade Tip Notch Location and Depth

(a) Put an identification tag on each borescope plug.
(2) Insert BORESCOPE DIA 0.16 TO 0.24 IN (4 TO 6 MM) - FLEXIBLE into position for the inspection.

Subtask 72-00-00-290-148-A

E. Identifying tip notched blades
(1) HPT stage 1 and stage 2 blade tip notches are visible through borescope port S.
(2) Identify HPT stage 1 blade position 1 by the trailing edge corner chamfer.
(3) Identify HPT stage 1 tip notched blades. There are 60 HPT stage 1 blades. Blade position 1 and blade position 31 are tip notched during assembly on the convex surface. See sheet 2 of the figure.

HPT Stage Blade Tip Notch Location and Depth

(4) Use Table 601 to determine amount of material loss on stage 1 blade position 1 and stage 1 blade position 31.
(a) 0.010 in. (0.254 mm) tip notch 0.38 in. (9.652 mm) from the trailing edge at the assembly.
(b) 0.020 in. (0.508 mm) tip notch 0.80 in. (20.320 mm) from the trailing edge at the assembly.

Table 601: HPT STG1 Blade Tip Notch Condition

Number of visible Tip Notches	Condition
2	Material loss on the blade tip less than 0.010 in. (0.254 mm)
1	Material loss on the blade tip between 0.010 in. (0.254 mm) and 0.020 in. (0.508 mm)
0	Material loss on the blade tip greater than 0.020 in. (0.508 mm)

(5) Identify the HPT stage 2 tip notched blades. There are 68 HPT stage 2 blades. Blade position 1 and blade position 35 are tip notched during assembly on the concave surface. See sheet 3 of the figure.

HPT Stage Blade Tip Notch Location and Depth

(6) Use Table 602 to determine the amount of material loss on the stage 2 blade position 1 and stage 1 blade position 35.
(a) 0.010 in. (0.254 mm) tip notch 0.80 in. (20.320 mm) from the trailing edge at the assembly.
(b) 0.020 in. (0.508 mm) tip notch 0.94 in. (23.876 mm) from the trailing edge at the assembly.

Table 602: HPT STG2 Blade Tip Notch Condition

Number of visible Tip Notches	Condition
2	Material loss on the blade tip less than 0.010 in. (0.254 mm)
1	Material loss on the blade tip between 0.010 in. (0.254 mm) and 0.020 in. (0.508 mm)
0	Material loss on the blade tip greater than 0.020 in. (0.508 mm)

Subtask 72-00-00-080-082-A

F. When the inspection is completed, remove BORESCOPE DIA 0.16 TO 0.24 IN (4 TO 6 MM) - FLEXIBLE.

Subtask 72-00-00-420-101-A

G. Install the borescope plugs in port S as follows:
(1) Do a visual inspection of the borescope plugs and the borescope ports (Ref. AMM TASK 72-00-00-290-812).
(2) Remove the identification tag from the borescope plug S before the installation of the plug.
(3) Verify borescope plug antirotation feature quality:
(a) Holding the borescope plug in one hand and holding the area near the tab, turn the antirotation feature one full revolution.
(b) Replace the borescope plug if there is no clicking sound when you turn the antirotation feature in the clockwise or counterclockwise direction.
(4) Put CP2619Never Seez-Pure Nickel, Special on the borescope plug threads and the mating surfaces.
(5) Install the borescope plugs S on the borescope port.
(a) TORQUE the borescope plug to between 97 and 83 lbf.in (1.10 and 0.94 m.daN )

Subtask 72-00-00-080-083-A

H. Remove the motoring tool (Ref. AMM TASK 72-00-00-820-803).

5. Close-up
Subtask 72-00-00-410-307-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 72-00-00-440-159-A

B. Do the reactivation of the thrust reverser after maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 72-00-00-410-308-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).

[Rev.10 from 2021] 2026.04.01 02:51:05 UTC