Find the Zero Index Mark of the High Pressure Compressor (HPC) Rotor [CFML]

TASK 72-00-00-820-802-A
Find the Zero Index Mark of the High Pressure Compressor (HPC) Rotor

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 task is to find the zero index of the high pressure compressor (HPC) rotor. This task is done before you examine all the blades in each stage of the high pressure compressor (HPC) rotor and high pressure turbine (HPT) rotor.
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 3.8 MM (0.15 IN)
No specific	1	DRIVE - HANDLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 20.0 and 15.0 lbf.in (0.23 and 0.17 m.daN )
No specific	Torque wrench: range to between 84.0 and 76.0 lbf.in (0.95 and 0.86 m.daN )
No specific	Torque wrench: range to between 215.3 and 194.8 lbf.in (2.43 and 2.20 m.daN )
9481M92	1	ELECTRONIC TURNOVER TOOL

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP1064)	milk of magnesia
(Material No.CP2101)	graphite grease
(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 72-00-00-820-803-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
High Pressure Compressor Zero Index

3. Job Set-up
Subtask 72-00-00-941-211-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, and
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 72-00-00-010-286-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 72-00-00-040-142-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 72-00-00-010-287-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 72-00-00-020-087-A

A. Find the Zero Index Mark of the High Pressure Compressor (HPC) Rotor (N2)
(1) Remove the motoring pad cover and install a DRIVE - HANDLE (3/4-Inch) or the 9481M92 ELECTRONIC TURNOVER TOOL (Ref. AMM TASK 72-00-00-820-803).
(2) Remove the borescope plug from the borescope port L.
(3) Insert BORESCOPE DIA 3.8 MM (0.15 IN) into the borescope port L.
(4) Identify the zero index mark for the HPC rotor as follows:
(a) Use the BORESCOPE DIA 3.8 MM (0.15 IN) to view the rotor blade platform for the ninth-stage HPC rotor.

NOTE: The rotor blade platform for the ninth-stage HPC rotor is aft of borescope port L.

(b) Slowly turn the DRIVE - HANDLE (3/4-Inch) or 9481M92 ELECTRONIC TURNOVER TOOL clockwise direction forward looking aft to turn the HPC rotor.

NOTE: The HPC ninth-stage leading edge rotor blades will turn in the same clockwise direction when viewing aft with the BORESCOPE.

(c) Look through the BORESCOPE DIA 3.8 MM (0.15 IN) until the first locking lug comes into view.
(d) Very slowly, continue to turn the HPC rotor until the second locking lug comes into view.

NOTE: The second locking lug is two blades away from the first locking lug.

(e) Align the leading edge of the blade that follows the second blade lock lug with the leading edge of the ninth-stage compressor stator vane.

NOTE: This will be blade No. 1.

(f) When the manual motoring procedure is used to identify the zero index mark, do this step:
1 Count the number of ninth-stage blades to know when a full turn of the HPC rotor is complete. The ninth-stage of the HPC rotor has 64 blades (60 blades plus 4 locking blades).
(g) When the electric motoring procedure is used to identify the zero index mark, do this step:
1 Use the manufacturer's instructions to set the electric motor tool display to zero degrees.
(5) All stages of the HPC rotor and HPT rotor are now zero-indexed in relation to each other.
(6) Remove the BORESCOPE DIA 3.8 MM (0.15 IN) from borescope port L.
(7) Install the borescope plug L as follows:
(a) Do a visual inspection of the threads on the borescope port.

NOTE: Minor damage of the threads, including burrs or galling, can be repaired. For thread information (Ref. AMM TASK 72-00-00-290-812). If you repair the threads, make sure that you do not let any debris enter the engine.

(b) Put milk of magnesia (Material No.CP1064) or CP2619Never Seez-Pure Nickel, Special or graphite grease (Material No.CP2101) on the threads of the inner and outer borescope plugs.
(c) TORQUE the inner borescope plug to between 84.0 and 76.0 lbf.in (0.95 and 0.86 m.daN )

.
(d) Loosen the inner borescope plug one quarter turn and TORQUE the inner plug again to between 20.0 and 15.0 lbf.in (0.23 and 0.17 m.daN )

.
(e) Compress the spring and TORQUE the outer borescope plug to between 215.3 and 194.8 lbf.in (2.43 and 2.20 m.daN )

.
(8) Remove the DRIVE - HANDLE (3/4-Inch) or 9481M92 ELECTRONIC TURNOVER TOOL and install the motoring pad cover (Ref. AMM TASK 72-00-00-820-803).

5. Close-up
Subtask 72-00-00-410-245-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 72-00-00-440-135-A

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

Subtask 72-00-00-410-246-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 02:50:23 UTC