Installation of a VBV Inter-connecting Flexible Shaft (Typical) [CFMB]

TASK 75-31-30-400-001-A
Installation of a VBV Inter-connecting Flexible Shaft (Typical)

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 1M(3 FT)
No specific	AR	WARNING NOTICE(S)

B. 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

C. 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 72-23-00-400-027-A	Installation of the Fan Duct Panels
TASK 73-29-00-710-040-B	Operational Test of the FADEC on the Ground (with Engine Motoring)
TASK 73-29-00-710-040-B-02	Operational Test of the FADEC on the Ground (with Engine Non motoring)
TASK 75-31-00-200-002-A	Manual Operation Check of the Variable Bleed Valve Doors
TASK 75-31-00-820-001-A	Adjustment of the Reference CLOSED Position of the VBV System
TASK 75-31-20-820-001-A	Set the Variable Bleed Valve Assembly to the Closed position
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
VBV Inter-connecting Flexible Shaft (Typical)

3. Job Set-up
Subtask 75-31-30-860-052-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
(3) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.

Subtask 75-31-30-010-059-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Make sure that the fan cowl doors are open: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(2) Make sure that the thrust reverser doors are open: (Ref. AMM TASK 78-36-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR.

Subtask 75-31-30-040-055-A ** ON A/C NOT FOR ALL

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

4. Procedure
Subtask 75-31-30-420-052-A ** ON A/C NOT FOR ALL

A. Installation of the VBV inter-connecting flexible shaft:
(1) Make sure that the VBV doors are in the reference CLOSED position. If not do this:
(a) Set the VBV system sector which includes the master bleed valve and ballscrew actuator to the CLOSED position (Ref. AMM TASK 75-31-20-820-001).
(b) Close the other sector of the VBV system (the one without the master bleed valve and ballscrew actuator) (Ref. AMM TASK 75-31-00-820-001).
(2) Install the inter-connecting flexible shaft as follows:

PRE SB CFM56-5 72-0119
Not applicable
End of PRE SB CFM56-5 72-0119

POST SB CFM56-5 72-0119

CAUTION: THE INNER DIAMETER OF THE NEW FERRULE HAS BEEN INCREASED AS THE HEXAGONAL END OF THE NEW MAIN FLEXIBLE SHAFT HAS BEEN ENLARGED.

(a) Flexible shaft/ferrule configuration.
do not mix old and new configuration of flexible shaft/ferrule assembly.
End of POST SB CFM56-5 72-0119

(b) Engage the hexagonal end (spring end) of the flexible shaft in the applicable actuator assembly, through the fan frame strut.
(c) Compress the spring, and engage the opposite end of the flexible shaft in the adjacent actuator assembly.
(d) Make sure that the VBV system is still in the reference CLOSED position. If not, adjust the VBV doors reference CLOSED (Ref. AMM TASK 75-31-00-820-001).
(e) Do a manual operation check of the Variable Bleed Valve doors (Ref. AMM TASK 75-31-00-200-002)
(f) Do an operational test of the FADEC on the ground (with engine motoring) (Ref. AMM TASK 73-29-00-710-040).
(3) Install fan duct panels (Ref. AMM TASK 72-23-00-400-027).

5. Close-up
Subtask 75-31-30-410-054-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 thrust reverser cowl doors: (Ref. AMM TASK 78-36-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR.
(3) Remove the access platform(s).

Subtask 75-31-30-440-052-A ** ON A/C NOT FOR ALL

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

Subtask 75-31-30-410-056-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close 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 WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 13:08:30 UTC