Visual Inspection of the Junction Box [CFMB]

TASK 72-23-00-210-007-A
Visual Inspection of the Junction Box

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	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2242)	RTV 732

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-B	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-B	Closing of the Fan Cowl Doors
TASK 72-23-00-300-046-A	Replacement of Lateral Bracket Plate on the Junction Box
TASK 78-30-00-081-041-B	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-B	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-B	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-B	Closing of the Thrust Reverser Doors
Junction Box

3. Job Set-up
Subtask 72-23-00-941-097-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 72-23-00-010-123-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(2) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(3) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(4) Put an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 72-23-00-040-078-A ** ON A/C NOT FOR ALL

C. Make the thrust reverser unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 72-23-00-010-136-A ** ON A/C NOT FOR ALL

D. Open the thrust reverser doors (Ref. AMM TASK 78-36-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR

4. Procedure
Subtask 72-23-00-210-067-A ** ON A/C NOT FOR ALL

A. Visual Inspection of the Junction Box

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Crack on the two lateral bracket plates.	One crack 0.78 in. (20 mm) max length.	Stop crack by drilling a 0.12 in. (3 mm) hole at each end of the crack. Clean the part. Apply RTV 732 (Material No.CP2242) or equivalent to the inner face of the affected area
	Any amount	Replace the lateral bracket plate (Ref. AMM TASK 72-23-00-300-046).
2.Loose or missing rivet on the two lateral bracket plates	Not serviceable	Replace the lateral bracket plate (Ref. AMM TASK 72-23-00-300-046).

Subtask 72-23-00-210-068-A ** ON A/C NOT FOR ALL

B. Visual Inspection of the Junction Box (PRE CFM SB 72-0845)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Crack on the lateral stiffeners.	One crack per stiffener is permitted if the crack is not going over the radius with lateral faces	Stop crack by drilling a 0.12 in. (3 mm) hole at each end of the crack. Clean the part with light duty aqueous cleaning. Apply RTV 732 (Material No.CP2242) or equivalent to the crack and drilled hole
Wear on the lateral stiffeners	Any amount if not going through the skin

Subtask 72-23-00-210-069-A ** ON A/C NOT FOR ALL

C. Visual Inspection of the Junction Box (POST CFM SB 72-0845)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Crack on the lateral stiffeners	Not serviceable
Wear on the lateral stiffeners	Any amount if not going through the skin

5. Close-up
Subtask 72-23-00-410-130-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser doors (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 72-23-00-440-073-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 72-23-00-410-115-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:41:56 UTC