Detailed Visual Inspection of the Ignition System [PW11]

TASK 74-00-00-210-802-A
Detailed Visual Inspection of the Ignition System

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 400

1. Reason for the Job
Use this procedure to do a detailed visual inspection of the ignition system.
For more information about the ignition system, refer to (74-00-00-00U).
2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
(Material No.P05-005)	lint-free cotton cloth
(Material No.P11-078)	alcohol, isopropyl

B. Work Zones and Access Panels

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

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-860-832-A	Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-802-A	Closing of the Fan Cowl Doors
TASK 73-21-63-000-802-A	Removal of the Electronic Engine Control (EEC) Wiring Harness (W03)
TASK 73-21-63-400-802-A	Installation of the Electronic Engine Control (EEC) Wiring Harness (W03)
TASK 73-21-64-000-802-A	Removal of the Electronic Engine Control (EEC) Wiring Harness (W04)
TASK 73-21-64-400-802-A	Installation of the Electronic Engine Control (EEC) Wiring Harness (W04)
TASK 73-25-34-400-802-A	Installation of the Engine Interface Unit (EIU)
TASK 74-11-01-000-801-A	Removal of the Ignition Exciter
TASK 74-11-01-400-801-A	Installation of the Ignition Exciter
TASK 74-21-00-100-801-A	Cleaning of the Ignition Exciter, Ignition Cables and Igniters
TASK 74-21-01-000-801-A	Removal of the Igniter Plug
TASK 74-21-01-400-801-A	Installation of the Igniter Plug
TASK 74-21-61-000-802-A	Removal of the Ignition Cables
TASK 74-21-61-400-802-A	Installation of the Ignition Cables
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-805-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
TASK 78-36-00-410-802-A	Closing of the Thrust Reverser Cowl-Doors
Ignition System

3. Job Set-up
Subtask 74-00-00-941-056-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832)

Subtask 74-00-00-865-067-A ** ON A/C NOT FOR ALL

B. Open, safety and tag these circuit breakers in this sequence:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENG 1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENG 2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42

Subtask 74-00-00-010-057-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR

Subtask 74-00-00-040-053-A ** ON A/C NOT FOR ALL

D. Deactivation of the Thrust Reverser for Ground 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 78-30-00-040-805).

Subtask 74-00-00-010-058-A ** ON A/C NOT FOR ALL

E. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL 462AR

4. Procedure
Subtask 74-00-00-210-052-A ** ON A/C NOT FOR ALL

A. Visual Inspection of the Ignition Exciter

WARNING: IGNITION SYSTEM VOLTAGE IS DANGEROUSLY HIGH. THE IGNITION SWITCH MUST BE IN THE "OFF" POSITION BEFORE REMOVING OR INSTALLING ANY IGNITION COMPONENTS. AFTER DISCONNECTING CABLE FROM IGNITER PLUG, DISCHARGE CURRENT BY GROUNDING IGNITION CABLE TERMINAL TO ENSURE COMPLETE DISSIPATION OF ENERGY FROM THE SYSTEM. FAILURE TO FOLLOW THIS PROCEDURE COULD RESULT IN SEVERE INJURY TO PERSONNEL.

WARNING: THE IGNITION SWITCH MUST BE IN THE "OFF" POSITION BEFORE YOU REMOVE IGNITION COMPONENTS. THE IGNITION SYSTEM USES HIGH ENERGY WHICH IS DANGEROUS. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY OR DEATH CAN BE THE RESULT.

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

(1) Do a visual inspection of the ignition exciter as follows:
see the sheet 1 of the figure and Table 601.

NOTE: Arcing is identified by pitting or discoloration on the contact button. Flashover is identified by carbon tracking, which is identified by narrow black carbon deposits that start from the contact button and continue along the ceramic inner side wall.

(a) Disconnect the ignition leads and wiring harnesses (W03) and (W04) from the ignition exciter (Ref. AMM TASK 74-11-01-000-801), (Ref. AMM TASK 73-21-64-000-802) and (Ref. AMM TASK 73-21-63-000-802).
(b) Examine the ignition exciter.
(c) Connect the ignition leads and wiring harnesses (W03) and (W04) to the ignition exciter (Ref. AMM TASK 74-11-01-400-801), (Ref. AMM TASK 73-21-64-400-802) and (Ref. AMM TASK 73-21-63-400-802).

Table 601 - Ignition Exciter Inspection

Examine	Damage	Disposition
Exciter case for:
Scratches	Scratches are found	Scratches are permitted if the scratch does not go through the plating and is less than 0.003 in. (0.076 mm) depth, 0.015 in. (0.381 mm) width or 1.0 in. (25.40 mm) length. If the scratch exceeds permitted limits, replace the ignition exciter (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801).
Dents	Dents are found	Dents are permitted if the dent is not more than two percent of the total case area, does not affect the fit or function and is not more than 0.03 in. (0.762 mm) in depth. If the dent exceeds the limit, replace the ignition exciter (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801).
Cracks or abrasions	Cracks or abrasions are found	No cracks or abrasions are permitted. Replace the ignition exciter (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801).
Exciter input connector for:
Broken or bent pins	Broken or bent pins are found	If the pins are bent more than ten degrees or broken, replace the ignition exciter to (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801). If the pins are bent less than ten degrees, straighten the pins. Use a socket contact (of the correct size) over the bent pin to make it straight. Do not use needle nose pliers.
Exciter mounting bracket holes for:
Elongation	Elongation is found	Mounting bracket hole elongation is permitted if elongation is not more than 0.3 in. (7.62 mm). If elongation exceeds the limit, replace the ignition exciter (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801).
Exciter input/output connector threads for:
Damage	Thread damage is found	No thread damage is permitted. Chasing of the threads is not permitted. Replace the ignition exciter (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801).
Exciter output receptacle well for:
Damage, signs of arcing or flashover on the contact button	Signs of damage, arcing or flashover is found	Small quantities of discoloration or pitting of the contact button can be removed (Ref. AMM TASK 74-21-00-100-801). If you cannot remove the button discoloration or pitting, replace the ignition exciter (Ref. AMM TASK 74-11-01-000-801) and (Ref. AMM TASK 74-11-01-400-801).

Subtask 74-00-00-210-053-A ** ON A/C NOT FOR ALL

B. Visual Inspection of the Igniter Plug(s)

WARNING: DURING THE INSPECTION, MAKE SURE THAT:

YOU MOVE OR TOUCH THE IGNITER PLUGS CAREFULLY
YOU DO NOT HIT THE IGNITER PLUGS OR LET THEM FALL.

IF THE IGNITER PLUGS BECOME DAMAGED, DANGEROUS ELECTRICAL ARCING OR GAS LEAK PATHS CAN OCCUR. THIS CAN CAUSE DEATH OR INJURY TO PERSONS.

(1) Do a visual inspection of the igniter plug(s) as follows:
see the sheets 1, 2 and 3 of the figure and Table 602.

NOTE: The igniter plug may show signs of superficial corrosion due to tarnishing of the external surfaces. This condition is normal and does not affect the form, fit or function of the igniter. Cleaning or trying to remove the tarnish is not necessary.

NOTE: The use of a thread chasing die is not permitted on the igniter plug. The threads are silver plated and have a tight tolerance to ensure proper fit is achieved. Excessive rework of the threads can cause installation damage.

NOTE: Breaks in the ceramic insulator can be found when you shake the igniter plug and listen for rattling sounds.

(a) Remove the igniter plug(s) from the engine (Ref. AMM TASK 74-21-01-000-801).
(b) Clean the igniter plug (Ref. AMM TASK 74-21-00-100-801).
(c) Examine the igniter plug(s).
(d) Install the igniter plug(s) (Ref. AMM TASK 74-21-01-400-801).

Table 602 - Igniter Plug Inspection

Examine	Damage	Disposition
Igniter plug gaskets for:
Damage	Damage is found	Replace gasket
Igniter plug coupling thread and wrench flats for:
Corrosion	Surface corrosion is found	Permitted
Igniter plug and shell coupling threads for:
Damage	Thread damage is found	If a small quantity of thread damage (nicks, dents or burrs) is found, repair the threads with a fine file (PN AMS Swiss No. 2). If the threads are damaged more than the small file can repair, replace the igniter plug (Ref. AMM TASK 74-21-01-000-801) and (Ref. AMM TASK 74-21-01-400-801).
Igniter plug ceramic insulator for:
Breaks, cracks or looseness	Breaks, cracks or looseness found	Not permitted. Replace the igniter plug (Ref. AMM TASK 74-21-01-000-801) and (Ref. AMM TASK 74-21-01-400-801).
Igniter plug semiconductor for:
Radial cracks or missing pieces	Cracks or missing pieces found	Not permitted. Replace the igniter plug (Ref. AMM TASK 74-21-01-000-801) and (Ref. AMM TASK 74-21-01-400-801).
Igniter plug barrel Outer Diameter (OD) for:
Oil, dirt and conductive contamination	Contamination is found	No contamination is permitted. Clean the igniter plug barrel OD with a clean lint-free cotton cloth (Material No.P05-005) and P11-078alcohol, isopropyl (Ref. AMM TASK 74-21-00-100-801).
Igniter plug ground shell for:
Erosion	Ground shell inner diameter is more than 0.33 in. (8.382 mm).	Replace the igniter plug (Ref. AMM TASK 74-21-01-000-801) and (Ref. AMM TASK 74-21-01-400-801).
	Depth measured from the end of the igniter plug ground shell to the tip of the center electrode is more than 0.125 in. (3.175 mm).	Replace the igniter plug (Ref. AMM TASK 74-21-01-000-801) and (Ref. AMM TASK 74-21-01-400-801).
Igniter plug terminal well for:
Oil, dirt and conductive contamination	Contamination is found	No contamination is permitted. Clean the igniter plug terminal well with a clean lint-free cotton cloth (Material No.P05-005) and P11-078alcohol, isopropyl (Ref. AMM TASK 74-21-00-100-801).
Arcing or flashover	Signs of arcing or flashover are found	No arcing and/or flashover is permitted. Small quantities of arcing or flashover can be removed (Ref. AMM TASK 74-21-00-100-801). If the arcing cannot be removed, replace the igniter plug (Ref. AMM TASK 74-21-01-000-801) and (Ref. AMM TASK 74-21-01-400-801).

Subtask 74-00-00-210-054-A ** ON A/C NOT FOR ALL

C. Visual Inspection of the Ignition Cables
(1) Do a visual inspection of the ignition cables as follows:
see the sheets 1, 2 and 4 of the figure and Table 603.

(a) Disconnect igniter cable A or B from the igniter plug and then from the ignition exciter (Ref. AMM TASK 74-21-61-000-802).
(b) Examine igniter cable A or B.
(c) Connect igniter cable system A or B to the igniter plug and then ignition exciter (Ref. AMM TASK 74-21-61-400-802).

Table 603 - Ignition Cable Inspection

Examine	Damage	Disposition
Igniter cable conduit for:
Cuts, abrasions or other damage	Chafing that goes through the outer conduit assembly braid with a length no more than 1.0 in. (25.4 mm) or more than one half of the circumference is permitted. Chafing areas must be separated by 3.0 in. (76.2 mm) and the total amount of chafing must not be more than ten percent of the total cable length. Small contact wear is permitted to the conduit core. No damage is permitted to the conduit core. To prevent more chafing, move cable tension between spring clips to make sure there is no interference condition.	Replace the ignition cable. Refer to (Ref. AMM TASK 74-21-61-000-802) and (Ref. AMM TASK 74-21-61-400-802).
Oil, dirt or conductive contaminants	Contamination is found	No contamination of the cable conduit is permitted. Clean the conduit with a clean lint-free cotton cloth (Material No.P05-005) and P11-078alcohol, isopropyl (Ref. AMM TASK 74-21-00-100-801).
Igniter cable lead assembly contact for:
Heavy pitting or wear	Heavy pitting or wear found	Not pitting or wear permitted. Replace the ignition cable (Ref. AMM TASK 74-21-61-000-802) and (Ref. AMM TASK 74-21-61-400-802).
Igniter cable lead assembly contact tips for:
Arcing	Signs of arcing is found	No arcing permitted. Small quantities of arcing can be removed (Ref. AMM TASK 74-21-00-100-801). If the arcing cannot be removed, replace the ignition cable (Ref. AMM TASK 74-21-61-000-802) and (Ref. AMM TASK 74-21-61-400-802).
Igniter cable ceramic insulator for:
Flashover	Signs of flashover is found (without structural damage to the insulator)	Clean the igniter cable ceramic insulator with a clean lint-free cotton cloth (Material No.P05-005) and P11-078alcohol, isopropyl (Ref. AMM TASK 74-21-00-100-801).
	Signs of flashover is found (with structural damage to the insulator)	Replace the ignition cable (Ref. AMM TASK 74-21-61-000-802) and (Ref. AMM TASK 74-21-61-400-802).
Igniter cable coupling nuts for:
Rounded corners	Rounded corners found	Replace the ignition cable (Ref. AMM TASK 74-21-61-000-802) and (Ref. AMM TASK 74-21-61-400-802).
Igniter cable tube and elbow for:
Looseness or damage	Looseness or damage found	Replace the ignition cable (Ref. AMM TASK 74-21-61-000-802) and (Ref. AMM TASK 74-21-61-400-802).

(2) Examine the assembly for foreign objects, damage and correct assembly.

5. Close-up
Subtask 74-00-00-410-057-A ** ON A/C NOT FOR ALL

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 78-36-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL 462AR

Subtask 74-00-00-440-053-A ** ON A/C NOT FOR ALL

B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-805).

Subtask 74-00-00-410-058-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).
(3) Make sure that all the circuit breakers shown in the paragraph Procedure of the engine interface unit installation are closed. If they are not, close them in the recommended sequence
(Ref. AMM TASK 73-25-34-400-802)

Subtask 74-00-00-865-068-A ** ON A/C NOT FOR ALL

D. Remove the safety clips and tags and close these circuit breakers in this sequence:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 1000EM1 (ENGINE1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
FOR FIN: 1000EM2 (ENGINE2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42

[Rev.10 from 2021] 2026.04.02 07:39:42 UTC