Visual Inspection of the Igniter [CFML]

TASK 74-21-10-210-801-A
Visual Inspection of the Igniter

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: BEFORE YOU START WORK ON THE IGNITION SYSTEM, MAKE SURE THAT THE IGNITION EXCITERS ARE DE-ENERGIZED FOR A MINIMUM OF FIVE MINUTES. ALSO DO NOT TOUCH THE ELECTRICAL CONTACTS. THE IGNITION SYSTEM VOLTAGE IS VERY HIGH, AND THE IGNITION EXCITERS CAN HAVE AN ELECTRICAL CHARGE EVEN WHEN NOT ENERGIZED. IF YOU DO NOT OBEY THESE PRECAUTIONS, INJURY CAN OCCUR.

1. Reason for the Job
Self 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	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. 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

C. 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 72-52-00-290-803-A	Borescope Inspection of High Pressure Turbine
TASK 74-21-10-000-802-A	Removal of the No. 1 (Left) Igniter
TASK 74-21-10-000-803-A	Removal of the No. 2 (Right) Igniter
TASK 74-21-10-400-802-A	Installation of the No. 1 (Left) Igniter
TASK 74-21-10-400-803-A	Installation of the No. 2 (right) Igniter
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
Igniter

3. Job Set-up
Subtask 74-21-10-941-058-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 74-21-10-865-066-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42

Subtask 74-21-10-010-068-A

C. 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 74-21-10-040-060-A

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

Subtask 74-21-10-010-069-A

E. 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

Subtask 74-21-10-020-065-A

F. Remove the igniter (Ref. AMM TASK 74-21-10-000-802) or (Ref. AMM TASK 74-21-10-000-803).

4. Procedure
Subtask 74-21-10-210-052-A

A. Do a Visual Inspection of the Igniter

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Body for: Wear from contact with the combustion chamber	Any amount, 0.030 in. (0.76 mm) deep. No wear completely through the shell is permitted.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Wear through the body from internal arcing	No wear through the body is permitted.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
2.Tip for: Distortion	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Electrode loose or missing	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Tip electrode height in relation to the shell tip	0.25 in. (6.35 mm) max depth below the tip.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Ceramic material cracked or missing pieces	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
3.Threaded connector end for: NOTE: Do a borescope inspection of the high-pressure turbine rotor when the pin electrodes have missing pieces (Ref. AMM TASK 72-52-00-290-803). Dirt/grease in the terminal well	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Cracked or missing ceramic pieces	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Arcing or erosion on the button contact	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).
Carbon track on the ceramics	Not serviceable.	Replace the igniter (Ref. AMM TASK 74-21-10-000-802) and (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-000-803) and (Ref. AMM TASK 74-21-10-400-803).

5. Close-up
Subtask 74-21-10-420-065-A

A. Install the igniter (Ref. AMM TASK 74-21-10-400-802) or (Ref. AMM TASK 74-21-10-400-803).

Subtask 74-21-10-410-062-A

B. 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 74-21-10-440-056-A

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

Subtask 74-21-10-410-063-A

D. 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 74-21-10-865-067-A

E. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42

[Rev.10 from 2021] 2026.04.01 13:04:18 UTC