Removal of the Ignition Cables [PW11]

TASK 74-21-61-000-802-A
Removal of the Ignition Cables

WARNING: USE NECESSARY PRECAUTIONS WHEN YOU DO WORK ON THE ENGINE IGNITION SYSTEM. THIS SYSTEM HAS HIGH ENERGY AND CAN CAUSE INJURY OR DEATH BY ELECTRICAL SHOCK.

WARNING: BEFORE YOU REMOVE/INSTALL IGNITION COMPONENTS:

WAIT FOR SOME MINUTES AFTER THE IGNITION SYSTEM IS USED
MAKE SURE THAT THE ENG/MODE SELECTOR SWITCH IS IN THE NORM POSITION.

AFTER YOU REMOVE THE IGNITER LEAD FROM THE IGNITER PLUG, IMMEDIATELY PUT THE IGNITION LEAD TERMINAL IN CONTACT WITH A GOOD GROUND TO LET ALL OF THE ELECTRICAL ENERGY OUT OF THE SYSTEM. THE IGNITION SYSTEM VOLTAGE IS VERY HIGH. IF YOU DO NOT OBEY THESE INSTRUCTIONS, INJURY OR DEATH CAN OCCUR.

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: 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.

ZONE: 400
FIN: 4038JH ** ON A/C NOT FOR ALL
FIN: 4039JH ** ON A/C NOT FOR ALL

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	COVER - PROTECTION

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 71-00-00-860-833-A	Procedure to Prevent Engine Motoring
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 72-21-11-000-801-A	Removal of the Lower BiFi
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
Removal of the Ignition Cables

3. Job Set-up
Subtask 74-21-61-941-055-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).

Subtask 74-21-61-865-053-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 74-21-61-010-054-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 74-21-61-040-052-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 74-21-61-010-055-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 74-21-61-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the Ignition Cables

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

(1) Find the ignition cable A or B (1) attached to the igniter plug and the ignition exciter from the 3 to 5 o'clock positions on the engine.
(2) Remove the ignition cable (1) from the engine as follows:

CAUTION: USE A SECOND WRENCH TO HOLD THE MATING PARTS WHEN YOU LOOSEN OR TIGHTEN THE TUBE OR HOSE NUTS. IF YOU DO NOT OBEY THIS CAUTION, YOU CAN TWIST OR CAUSE DAMAGE TO THE TUBES OR HOSES.

CAUTION: DO NOT BEND OR TWIST THE IGNITION CABLES. REMOVE THE CABLE ENDS STRAIGHT FROM THE IGNITER PLUG RECEPTACLES. IF NECESSARY, UNCLIP THE IGNITION CABLE FROM THE SPRING CLIPS TO REMOVE TENSION FROM THE CABLE. IF YOU DO NOT OBEY THIS CAUTION, YOU CAN CAUSE DAMAGE TO THE CABLE ENDS AND/OR IGNITER PLUG CERAMIC.

(a) Look to see if SB C-74-00-0001A has been incorporated before you perform the maintenance steps below.

NOTE: This Service Bulletin changes the igniter to exciter plug cable routing at the igniter plug end so that the igniter plug (upper) will be connected to ignition system B and the igniter plug (lower) will be connected to ignition system A.

(b) If the Service Bulletin is used, the cables should be routed per the Service Bulletin.

NOTE: The figures in this procedure show the pre Service Bulletin configuration.

(c) Disconnect the ignition cable (1) from the igniter plug.
(d) Disconnect the ignition cable (1) from the ignition exciter.
(e) Remove the ignition cables (1) from the lower BiFi (Ref. AMM TASK 72-21-11-000-801).
(f) Disengage the ignition cable (1) from the spring clips.
(g) Remove the ignition cable (1).
(h) Place the ignition cable (1) in a suitable container.
(3) Examine the assembly for unwanted objects, damage and correct assembly.
(4) Installation of protection covers:

CAUTION: INSTALL PROTECTION COVERS ON ALL THE OPENINGS IMMEDIATELY TO PREVENT DAMAGE TO THE ENGINE.

(a) Install COVER - PROTECTION as necessary to prevent damage to the engine.

[Rev.10 from 2021] 2026.04.01 13:02:02 UTC