Visual Inspection of the Thrust Reverser Electrical Harnesses [CFML]

TASK 71-51-43-210-801-A
Visual Inspection of the Thrust Reverser Electrical Harnesses

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: 400

1. Reason for the Job
A. This procedure gives the instructions to do an inspection of the thrust reverser electrical harnesses
B. The harnesses of the hydraulic thrust reverser actuation system (HTRAS) include

Right primary lock channel A electrical harness (4771EG)
Right primary lock channel B electrical harness (4772EG)
Isolation Control Unit (ICU) channel A electrical harness (4765EG)
ICU channel B electrical harness (4766EG)
Direction Control Unit (DCU) channel A electrical harness (4767EG)
DCU channel B electrical harness (4768EG)
Tertiary Locking System (TLS) power electrical harness (PJB to LH Break) (4773EG)
TLS power electrical harness (LH Break to TLS) (4774EG)
Left primary lock/TLS channel A and B electrical harness (LH Break to LH SLFA) (4769EG)
Left primary lock/TLS channel A and B electrical harness (LH Break to RH Break) (4770EG).

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	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CPNCL02662)	isopropyl alcohol

C. 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

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 71-51-43-000-805-A	Removal of the HTRAS/CLP Harnesses - ICU Channel A and Channel B
TASK 71-51-43-000-806-A	Removal of the Thrust Reverser Actuation System Electrical Harnesses
TASK 71-51-43-000-813-A	Removal of the Thrust Reverser Harnesses - Right Upper Actuator Channel A and Channel B Harnesses
TASK 71-51-43-400-805-A	Installation of the HTRAS/CLP Harnesses - ICU Channel A and Channel B
TASK 71-51-43-400-806-A	Installation of the Thrust Reverser Actuation System Electrical Harnesses
TASK 71-51-43-400-813-A	Installation of the Thrust Reverser Harnesses - Right Upper Actuator Channel A and Channel B Harnesses
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-30-00-440-807-A	Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU)
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
Thrust Reverser Electrical Harnesses

3. Job Set-up
Subtask 71-51-43-941-094-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 71-51-43-010-114-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 71-51-43-040-054-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 71-51-43-010-115-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 71-51-43-210-051-A

A. Visual inspection of the Thrust Reverser Electrical Harnesses
(1) Do the visual inspection of the right primary lock channel A electrical harness (1), right primary lock channel B electrical harness (2), Isolation Control Unit (ICU) channel A electrical harness (3), ICU channel B electrical harness (4), Direction Control Unit (DCU) channel A electrical harness (5), DCU channel B electrical harness (6), Tertiary Locking System (TLS) power electrical harness (PJB to Left Hand (LH) Break) (7), TLS power electrical harness (LH Break to TLS) (8), Left primary lock/TLS channel A and B electrical harness (LH Break to LH SLFA) (9), Left primary lock/TLS channel A and B electrical harness (LH Break to Right Hand (RH) Break) (10):

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Damage, cracking, missing rubber or swelling of the connector receptacle interfacial seal	Not serviceable.	If damaged, replace the applicable electrical harness (Ref. AMM TASK 71-51-43-000-813) and (Ref. AMM TASK 71-51-43-400-813), (Ref. AMM TASK 71-51-43-000-806) and (Ref. AMM TASK 71-51-43-400-806), (Ref. AMM TASK 71-51-43-000-805) and (Ref. AMM TASK 71-51-43-400-805).
2.Contamination of the connector receptacle interfacial seal	Any amount that can be removed by isopropyl alcohol (Material No.CPNCL02662) .
3.Signs of arcing or electrical failure on the electrical connectors and contacts	Not serviceable.	If damaged, replace the applicable electrical harness (Ref. AMM TASK 71-51-43-000-813) and (Ref. AMM TASK 71-51-43-400-813), (Ref. AMM TASK 71-51-43-000-806) and (Ref. AMM TASK 71-51-43-400-806), (Ref. AMM TASK 71-51-43-000-805) and (Ref. AMM TASK 71-51-43-400-805).
4.Worn threads, stripped threads, corrosion or other damage on the connectors and backshells	Not serviceable.	If damaged, replace the applicable electrical harness (Ref. AMM TASK 71-51-43-000-813) and (Ref. AMM TASK 71-51-43-400-813), (Ref. AMM TASK 71-51-43-000-806) and (Ref. AMM TASK 71-51-43-400-806), (Ref. AMM TASK 71-51-43-000-805) and (Ref. AMM TASK 71-51-43-400-805).
5.Oil or dirt on exposed parts	Any amount that can be removed by cleaning with isopropyl alcohol (Material No.CPNCL02662) .
6.Bent or broken pins	Not serviceable.	If damaged, replace the applicable electrical harness (Ref. AMM TASK 71-51-43-000-813) and (Ref. AMM TASK 71-51-43-400-813), (Ref. AMM TASK 71-51-43-000-806) and (Ref. AMM TASK 71-51-43-400-806), (Ref. AMM TASK 71-51-43-000-805) and (Ref. AMM TASK 71-51-43-400-805).
7.Damaged polyether ether ketone or metal overbraid	Missing polyether ether ketone overbraid less than 0.5 in.2 (322.58 mm2) in area and less than 2.0 in. (50.80 mm) in length is permitted but should be repaired. Abraded areas on the metal overbraid under the polyether ether ketone are acceptable. Broken strands are acceptable as long as they do not create an exposure or hole larger than 0.1 in. (2.54 mm) in length or width. Exposure or hole up to 0.5 in. (12.70 mm) in length or width may be repaired. Reject the harness if there is any damage to the PTFE conductor insulation beneath the metal and fiberglass overbraid. Minor abrasion is acceptable providing the insulation layer is intact.	If overbraid is damaged within serviceable limits, repair (Ref. AMM D/O 71-51-43-30). If overbraid is damaged beyond serviceable limits, replace the applicable electrical harness (Ref. AMM TASK 71-51-43-000-813) and (Ref. AMM TASK 71-51-43-400-813), (Ref. AMM TASK 71-51-43-000-806) and (Ref. AMM TASK 71-51-43-400-806), (Ref. AMM TASK 71-51-43-000-805) and (Ref. AMM TASK 71-51-43-400-805).
8.Dents, welds which have cracks or other damage	Not serviceable.	If damaged, replace the applicable electrical harness (Ref. AMM TASK 71-51-43-000-813) and (Ref. AMM TASK 71-51-43-400-813), (Ref. AMM TASK 71-51-43-000-806) and (Ref. AMM TASK 71-51-43-400-806), (Ref. AMM TASK 71-51-43-000-805) and (Ref. AMM TASK 71-51-43-400-805).

5. Close-up
Subtask 71-51-43-410-085-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser 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 71-51-43-440-052-A

B. Do the reactivation of the thrust reverser system after nacelle maintenance (Ref. AMM TASK 78-30-00-440-807).

Subtask 71-51-43-410-086-A

C. Close Access
(1) Remove the access platform(s).
(2) 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.
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.02 06:33:30 UTC