Removal of the Electrical Harness HJ2B for the Channel B Ignition System [CFML]

TASK 71-51-43-000-810-A
Removal of the Electrical Harness HJ2B for the Channel B Ignition System

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.

ZONE: 400
FIN: 4178KS

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 2M (6 FT) - ADJUSTABLE
No specific	AR	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
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 70-70-00-910-804-A	Electrical Standard Practices
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 72-24-07-000-801-A	Removal of the Fireproof Plate
TASK 74-11-05-000-801-A	Removal of Ignition Exciter 1
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
Electrical Harness for the Channel B Ignition System HJ2B (PRE and POST SB 72-0402)

3. Job Set-up
Subtask 71-51-43-941-088-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 71-51-43-010-108-A

B. 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 2M (6 FT) - ADJUSTABLE in position under the right fan cowl door.

Subtask 71-51-43-040-060-A

C. 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 nacelle maintenance (Ref. AMM TASK 78-30-00-040-807).

Subtask 71-51-43-010-120-A

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

4. Procedure
Subtask 71-51-43-020-090-A

A. Removal of the Electrical Harness for the Channel B Ignition System
(1) Remove the four bolts (41) and the exciter shroud lid (42) from the exciter shroud (43) to get access to the ignition exciter (40) (Ref. AMM TASK 74-11-05-000-801).
(2) Before you remove the electrical harness (2) make a record of the harness routing to help during installation.
(3) Disconnect the electrical connectors that follow (Ref. AMM TASK 70-70-00-910-804):

Disconnect the electrical connector (21) from the receptacle on the channel B Electronic Engine Control (EEC) (23).
Disconnect the electrical connector (39) from the ignition exciter (40).
Disconnect the electrical connector (1) from the receptacle on the Pylon Junction Box (PJB) (6).

(4) Carefully pull the electrical harness (2) out of the spring clips on the support brackets (38), (34) and (30).
(5) Remove the fireproof plate and fireproof block (33) (Ref. AMM TASK 72-24-07-000-801).
(6) Remove the electrical harness (2) from the fireproof block (33).
(7) Disconnect the electrical connector (9) at the support bracket (16) as follow:
(a) Disconnect the electrical connector (15) from the aft side of the support bracket (16).
(b) Remove the two bolts (14) that attach the electrical connector (9) to the support bracket (16).
(c) Manually move the electrical connector (9) away from the support bracket (16).
(8) Disconnect the electrical connector (13) at the support bracket (12) as follow:
(a) Disconnect the electrical connector (10) from the forward side of the support bracket (12).
(b) Remove the two bolts (11) that attach the electrical connector (13) to the support bracket (12).
(c) Manually move the electrical connector (13) away from the support bracket (12).
(9) Remove the bolt (4) that attaches the P-clamp (3) to the support bracket (5).
(10) Remove the bolt (46) that attaches the P-clamp (47) to the support bracket (17).
(11) Carefully pull the electrical harness (2) out of the spring clips on the support brackets (7), (16), (17), (18), (22), (20), (25), (26), (28), (29) (30), (34), (38), (44) and (45).
(12) Remove the electrical harness (2) from the engine.
(13) Make a record of the location and position of the P-clamps (3) and (47) on the electrical harness (2) to help during installation.
(14) Remove the P-clamp (3) and (47) from the electrical harness (2).
(15) Install COVER - PROTECTION and CAP - PROTECTION on all open connectors and receptacles.

[Rev.10 from 2021] 2026.04.02 06:33:29 UTC