Removal of the Electrical Harness from the Pylon to the Core Fire Detector Elements [CFML]

TASK 71-52-43-000-803-A
Removal of the Electrical Harness from the Pylon to the Core Fire Detector Elements

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.

FIN: 4204KS
FIN: 4205KS

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	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
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 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 from the Pylon to the Core Fire Detector Elements

3. Job Set-up
Subtask 71-52-43-941-058-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 a 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 71-52-43-010-091-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 1M(3 FT) in position.

Subtask 71-52-43-040-075-A

C. Deactivation of the Thrust Reverser System for Nacelle 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 71-52-43-010-092-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 71-52-43-020-065-A

A. Removal of the Left (Channel A) Electrical Harness (4204KS) and the Right (Channel B) Electrical Harness (4205KS) from the Pylon to the Core Fire Detector Elements
(1) Before you remove the left channel A harness (4204KS) (15) and right channel B harness (4205KS) (6), make a record of the harness routing to help during installation.
(2) Disconnect the left channel A harness (4204KS) (15) from the left responder (8) as follows:
(a) Remove the screw (10) that attaches the harness clamp (2) to the left responder (8).
(b) Remove the two nuts (3) and (9), and the left channel A harness (4204KS) (15) from the responder (8).
(c) Remove the bolt (11) that attaches the left channel A harness (4204KS) (15) to the support bracket (13).
(d) Remove the bolt (14) that attaches the harness clamp to the support bracket (16).
(e) Remove the left channel A harness (4204KS) (15) from the spring clip on the support bracket (1).
(f) Move the free end of the left channel A harness (4204KS) (15) over the engine to the right side.
(3) Put the ACCESS PLATFORM 1M(3 FT) in position under the right thrust reverser cowl door.
(4) Disconnect the right channel B harness (4205KS) (6) from the right responder (8) as follows:
(a) Remove the screw (10) that attaches the harness clamp (2) to the responder (8).
(b) Remove the two nuts (3) and (9), and the right channel B harness (4205KS) (6) from the responder (8).
(c) Remove the bolt (5) that attaches the right channel B harness (4205KS) (6) to the support bracket (7).
(d) Remove the bolt (4) that attaches the harness clamp to the support bracket (7).
(5) Disconnect the right channel B harness (4205KS) (6) and the left channel A harness (4204KS) (15) from the pylon interface (25) as follows:
(a) Disconnect the electrical connector (24) of the right channel B harness (4205KS) (6) from the pylon interface (25).
(b) Disconnect the electrical connector (23) of the left channel A harness (4204KS) (15) from the pylon interface (25).
(6) Remove the right channel B harness (4205KS) (6) and the left channel A harness (4204KS) (15) from the fire seal (19) as follows:
(a) Remove the four screws (22) from the pylon cover (21).
(b) Remove the outer half of the fire seal (19) from the pylon frame (20).
(c) Remove the right channel B harness (4205KS) (6) and the left channel A harness (4204KS) (15) from the grooves in the fire seal (19).
(7) Disconnect the right channel B harness (4205KS) (6) and the left channel A harness (4204KS) (15) from the support bracket (30) as follows:
(a) Remove the bolt (32) that attaches the P-clamp (31) and the right channel B harness (4205KS) (6) to the support bracket (30).
(b) Remove the bolt (28) that attaches the P-clamp (29) and the left channel A harness (4204KS) (15) to the support bracket (30).
(8) Remove the right channel B harness (4205KS) (6) and the left channel A harness (4204KS) (15) from the engine.
(9) Make a written record of the location and position of the P-clamps (29) and (31) on the harnesses (6) and (15) to help during installation.
(10) Remove the P-clamps (29) and (31) from the harnesses (6) and (15).
(11) Install COVER - PROTECTION and CAP - PROTECTION on all the connectors.

[Rev.10 from 2021] 2026.04.01 06:38:53 UTC