Find the Zero Index Mark of the N1 Rotor [CFML]

TASK 72-00-00-820-805-A
Find the Zero Index Mark of the N1 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 N1 rotor. This task is done before you examine all the blades in each stage of the Low Pressure Compressor (LPC) rotor and Low Pressure Turbine (LPT) rotor.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)
956A7616	1	MAT, PROTECTION - INLET COWL

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP5061)	temporary marking

C. Referenced Information

REFERENCE	DESIGNATION
Find the Zero Index Mark of the N1 Rotor

3. Job Set-up
Subtask 72-00-00-941-256-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:

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).

4. Procedure
Subtask 72-00-00-820-052-A

A. Do these steps to turn or index the N1 rotor.
(1) Put the 956A7616 MAT, PROTECTION - INLET COWL in the inlet cowl.
(2) Find the No. 1 fan blade.

NOTE: The No. 1 fan blade is adjacent to a machined dimple in the top area of the platform front shroud.

(3) Use of the temporary marking.

CAUTION: ON THE FAN BLADE, PUT A MARK WITH CP5061 TEMPORARY MARKING ON THE CONVEX SIDE METALLIC LEADING EDGE ONLY. IF YOU PUT MARKS WITH THIS TEMPORARY MARKING ON OTHER LOCATIONS, YOU CAN CAUSE DAMAGE TO THE FAN BLADE.

(a) Use the temporary marking (Material No.CP5061) and put a mark on the No. 1 fan blade convex side metallic leading edge to identify it easily.
(4) Align the leading edge of the No. 1 fan blade with the T12 sensor.

NOTE: The T12 sensor is approximately at the 12 o'clock position as you look in the inlet cowl.

(5) Remove the 956A7616 MAT, PROTECTION - INLET COWL.

5. Close-up
Subtask 72-00-00-942-078-A

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:50:25 UTC