Removal of the Ignition Lead 1 [CFML]

TASK 74-21-05-000-802-A
Removal of the Ignition Lead 1

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.

ZONE: 400
FIN: 4002JH11
FIN: 4002JH12

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
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 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
Ignition Lead 1 (PRE and POST SB 72-0402)

3. Job Set-up
Subtask 74-21-05-941-051-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 74-21-05-865-052-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 74-21-05-010-052-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

Subtask 74-21-05-040-051-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 maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 74-21-05-010-053-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

4. Procedure
Subtask 74-21-05-020-051-A

A. Removal of the Ignition Lead 1

CAUTION: DO NOT TWIST OR BEND THE IGNITION LEADS. IF YOU DO, DAMAGE TO THE LEADS CAN OCCUR.

(1) Remove the four bolts (4) that attach the exciter box shroud lid (3) to the exciter box shroud (1).
(2) Remove the exciter box shroud lid (3) from the exciter box shroud (1).
(3) Remove the hose clamp (32) that attaches the exciter rubber air manifold (5) to the ignition lead 1 (33) plenum.
(4) Remove the exciter rubber air manifold (5) from the ignition lead 1 (33) plenum.
(5) Remove the bolt (41) and loop clamp (40) that attach the ignition lead 1 (33) to the support bracket (11).
(6) Remove the bolt (35) and loop clamp (36) that attach the ignition lead 1 (33) to the air tube bracket (34).
(7) Remove the hose clamp (38) that attaches the main igniter cooling shroud (37) halves to the ignition lead 1 (33) and remove the main igniter cooling shroud (37) halves from the igniter 1 (left) (39).
(8) Disconnect the ignition lead 1 (33) B-nut from the ignition exciter 1 (31).

NOTE: Make sure that you pull the ignition lead 1 (33) straight out (no side loading).

(9) Disconnect the ignition lead 1 (33) B-nut from the igniter 1 (left) (39).
(10) Remove the ignition lead 1 (33) from the engine.
(11) Remove and discard the silicone washer (42) on the insulator at the igniter end of the ignition lead 1 (33).
(12) Install COVER - PROTECTION and CAP - PROTECTION on all the open ports, open tubes, open hoses and connectors.

[Rev.10 from 2021] 2026.04.01 03:08:51 UTC