Repair of the Engine Wiring Harness in the Harness Firewall Area [CFML]

TASK 73-21-60-300-802-A
Repair of the Engine Wiring Harness in the Harness Firewall Area

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

ZONE: 210
ZONE: 400

1. Reason for the Job
A. This procedure gives instructions to repair the copper braid of the harness installed in the firewall area Ref. Fig. Copper Braid for the Firewall and Permitted Limits of the Defective Area.

NOTE: You can use equivalent alternatives for standard tools and equipment.

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	1	PLIERS - END-CUTTING
No specific	1	PLIERS - TWISTING, SPECIAL
No specific	AR	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP1041)	isopropyl alcohol
(Material No.CP2628)	3M-363 tape
(Material No.CP2674)	lint-free cloth
(Material No.CP8005)	safetywire 0.024 in. (0.6 mm)

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD
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

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
Copper Braid for the Firewall and Permitted Limits of the Defective Area
3M-363 Tape
Safetywire 0.024 in. (0.6 mm)

3. Job Set-up
Subtask 73-21-60-941-085-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 73-21-60-010-105-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 73-21-60-040-065-A

C. Deactivation of the Thrust Reverser (T/R) 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 T/R system for ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 73-21-60-010-106-A

D. Get Access
(1) Open the T/R 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.

Subtask 73-21-60-990-052-A

E. Applicable Parts
The subsequent table gives a list of the part numbers that are applicable to this repair. All part numbers are applicable to all paragraphs unless specified differently.

Part Number	Service Bulletin	CSN	Designation
362-085-705-0	72-0015	(03–180–00A, 73–21–60)	Harness HJ5A
362-085-805-0	72-0015	(04–190–00A, 73–21–60)	Harness HJ5B
362-086-205-0	72-0015	(08–210–00A, 73–21–60)	Harness HJ8A
362-086-206-0	72-0019	(08–210–00B, 73–21–60)	Harness HJ8A
362-086-305-0	72-0015	(09–140–00A, 73–21–60)	Harness HJ8B
362-086-306-0	73-0012	(09–140–00B, 73–21–60)	Harness HJ8B
362-086-305-0	77-0001	(09–140–00C, 73–21–60)	Harness HJ8B

Table - Applicable Parts

4. Procedure
Subtask 73-21-60-220-060-A

A. Dimensional Information

Copper Braid for the Firewall and Permitted Limits of the Defective Area

3M-363 Tape

Safetywire 0.024 in. (0.6 mm)

NOTE: The dimensional data identified within this procedure was designed using millimeters as the base unit of measurement for dimensional values. The conversion to inches is rounded to two additional decimal digits than millimeters. For minimum dimensions, converted values are rounded up. For maximum dimensions, converted values are rounded down. To avoid conversion errors, do not re-convert from inches to millimeters.

NOTE: Reference dimensions do not require inspection.

Description	Minimum In-Process Dimension	Maximum In-Process Dimension	Minimum Finish Dimension	Maximum Finish Dimension	Reference Dimension
DIM. A (defective area)	-	-	-	80 mm (3.15 in.)	-
ANGLE D (defective area)	-	-	-	360 degrees	-
DIM. B (tape width)	-	-	50 mm (1.97 in.)	-	-
DIM. C (tape overlap)	-	-	5 mm (0.20 in.)	-	-

Table - Dimensional Information

Subtask 73-21-60-020-066-A

B. If necessary, loose the clamps as required until the area to repair is clear.

Subtask 73-21-60-210-058-A

C. Do a visual inspection of the area to repair. This repair only applies on harness branches in firewall braiding.

Subtask 73-21-60-110-052-A

D. Clean the external copper braid around the area to repair with a lint-free cloth (Material No.CP2674) moist with isopropyl alcohol (Material No.CP1041) .

Subtask 73-21-60-350-057-A

E. Prepare the area to repair as follows:
(1) Remove all material from the area to repair.
(2) Cut the strands of the damaged copper braid with the PLIERS - END-CUTTING.
(3) Make sure that the heat-shrinkable sleeve (black) under the copper braid is not worn.

Subtask 73-21-60-350-055-A

F. Wind the 3M-363 tape (Material No.CP2628) as follows:

3M-363 Tape

(1) Apply the first piece of 3M-363 tape (Material No.CP2628) starting from the end of the metallic transition.
(2) Make two turns minimum and three turns maximum with the first 3M-363 tape (Material No.CP2628) .
(3) Apply the second 3M-363 tape (Material No.CP2628) with an overlap minimum 5 mm (0.20 in.) on the first 3M-363 tape (Material No.CP2628) and a complete overlap of the braiding.

NOTE: An overlap on the heat-shrinkable sleeve is permitted.

(4) Make two turns minimum and three turns maximum with the second 3M-363 tape (Material No.CP2628) .

Subtask 73-21-60-350-056-A

G. Apply the CP8005safetywire 0.024 in. (0.6 mm) as follows:

Safetywire 0.024 in. (0.6 mm)

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL SAFETYWIRE. EACH TIME YOU CUT SAFETYWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE SAFETYWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(1) Start to apply the CP8005safetywire 0.024 in. (0.6 mm) from the metallic transition side as follows:
(a) Cut a piece of CP8005safetywire 0.024 in. (0.6 mm) approximately 500 mm (19.69 in.) long.
(b) Hold the two ends of the piece of CP8005safetywire 0.024 in. (0.6 mm) with the hands and put its middle part approximately 5 mm (0.20 in.) from the end of the copper braid.
(c) Make two turns around the first 3M-363 tape (Material No.CP2628) .
(2) Twist the two strands approximately three turns with PLIERS - TWISTING, SPECIAL, to brake on.
(3) Cross the strands three times around the 3M-363 tape (Material No.CP2628) in a homogeneous and equidistant way.
(4) Make two turns approximately 5 mm (0.20 in.) from the edge of the second 3M-363 tape (Material No.CP2628) .
(5) Twist the two strands approximately five to seven turns with PLIERS - TWISTING, SPECIAL, to brake on again.
(6) Cut and fold the twist on itself.

Subtask 73-21-60-210-059-A

H. Do a visual inspection of the repaired area.
(1) If the aluminum adhesive tape does not covered completely the copper braid, do the repair again.
(2) If the stainless steel wire has not three successive crossings, do the repair again.

Subtask 73-21-60-410-085-A

I. Put the harness back on its supports.

5. Close-up
Subtask 73-21-60-410-083-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the T/R cowl doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR.

Subtask 73-21-60-440-059-A

B. Do the reactivation of the T/R system after ground maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 73-21-60-410-084-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 13:07:23 UTC