Visual Inspection of the Variable Bleed Valve (VBV) Ducts in Composite Material Including Seals (POST SB LEAP 72-00-0206 and/or POST SB LEAP 72-00-0271) [CFML]

TASK 72-24-80-200-801-A-01
Visual Inspection of the Variable Bleed Valve (VBV) Ducts in Composite Material Including Seals (POST SB LEAP 72-00-0206 and/or POST SB LEAP 72-00-0271)

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

1. Reason for the Job
This procedure gives criteria for visual inspection of the VBV ducts in composite material including seals.

NOTE: The inspection criteria below are applicable after removal of frayed composite.

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

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	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 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 72-24-80-000-801-A	Removal of the Variable Bleed Valve (VBV) Ducts
TASK 72-24-80-400-801-A	Installation of the Variable Bleed Valve (VBV) Ducts
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
Visual Inspection of the VBV Ducts in Composite Material
Example of Visual Indications on VBV Ducts in Composite Material
Spalling or Fiber Tearing Examples and Authorized Zones

3. Job Set-up
Subtask 72-24-80-941-057-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 72-24-80-010-064-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.

Subtask 72-24-80-040-057-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 ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 72-24-80-010-065-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 72-24-80-210-056-A

A. Do a visual inspection of the VBV ducts in composite material including seals:
See Sheet 1 of the figure:

Visual Inspection of the VBV Ducts in Composite Material

(1) Visual inspection of all areas of the VBV ducts (2), (7), (11), (18), (24), (28), (34) and (36):
See Sheets 2, 3, 4, 5, 6, 7, 8 and 9 of the figure:

Visual Inspection of the VBV Ducts in Composite Material

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Delamination NOTE: Delamination=Opening between two plies	Any dimension up to 0.500 in. (12.7 mm) on the whole part Example of Visual Indications on VBV Ducts in Composite Material	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).
2.Junction mold line	Any amount Example of Visual Indications on VBV Ducts in Composite Material	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).
3.Nicks, dents, scratches	Any number up to 0.0039 in. (0.10 mm) in depth	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).
4.Porosity	Any amount	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).
5.Coloration	Example of Visual Indications on VBV Ducts in Composite Material	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).
6.Crazing	Example of Visual Indications on VBV Ducts in Composite Material	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).
7.Spalling and fiber tearing	Spalling or Fiber Tearing Examples and Authorized Zones	Replace the VBV ducts (Ref. AMM TASK 72-24-80-000-801) and (Ref. AMM TASK 72-24-80-400-801).

(2) Visual inspection of floating and replaceable nuts (3), (9), (12), (17), (21), (26), (33) and (38) and floating nut plates (4), (8), (13), (19), (22), (29), (35) and (39) of the VBV ducts (2), (7), (11), (18), (24), (28), (34) and (36):

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Missing	Not serviceable.
2.Looseness	Not serviceable.
3.Damage	Not serviceable.

(3) Visual inspection of seals (1), (5), (6), (10), (15), (14), (16), (20), (25), (23), (27), (30), (32), (31), (37) and (40):

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Signs of wear, textile delamination and color change	Not serviceable.
2.Breaks, cracks and scratches	Not serviceable.
3.Bubbles	Not serviceable.

5. Close-up
Subtask 72-24-80-410-063-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 72-24-80-440-057-A

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

Subtask 72-24-80-410-064-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 02:53:26 UTC