Manual Operation Check of the Variable Bleed Valve Doors [CFMB]

TASK 75-31-00-200-002-A
Manual Operation Check of the Variable Bleed Valve Doors

ZONE: 400

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 2M (6 FT) - ADJUSTABLE
No specific	AR	WARNING NOTICE(S)
856A2501	1	WRENCH-VBV MANUAL CONTROL

B. Work Zones and Access Panels

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

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
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 72-23-00-000-027-A	Removal of the Fan Duct Panels
TASK 72-23-00-400-027-A	Installation of the Fan Duct Panels
TASK 75-31-00-640-801-A	Re-greasing of the Variable Bleed Valve (VBV) System
TASK 75-31-70-400-002-A	Installation of the Variable Bleed Valve position Sensor
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

3. Job Set-up
Subtask 75-31-00-941-066-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 75-31-00-010-079-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.

Subtask 75-31-00-040-061-A ** ON A/C NOT FOR ALL

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

Subtask 75-31-00-010-080-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 75-31-00-010-081-A ** ON A/C NOT FOR ALL

A. Remove the fan duct panel, on the left or right of the No. 4 strut (Ref. AMM TASK 72-23-00-000-027).

Subtask 75-31-00-710-053-A ** ON A/C NOT FOR ALL

B. Operational check of the VBV system.
(1) Engage the 856A2501 WRENCH-VBV MANUAL CONTROL (856A2501G01) in the free end of the half of the VBV linkage system.
(2) Operate the system manually in the two directions, and make sure that it operates smoothly and freely.

NOTE: If necessary, re-grease the variable bleed valve system (Ref. AMM TASK 75-31-00-640-801).

(3) With the VBV actuators manually positioned on the CLOSED stop, verify that the sensor arm of the VBV position sensor (RVDT) is well aligned with the reference mark.

Subtask 75-31-00-861-050-A ** ON A/C NOT FOR ALL

C. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 75-31-00-865-052-A ** ON A/C NOT FOR ALL

D. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 1000EM1 (ENGINE1)
49VU	ENGINE/1/FADEC A/AND EIU 1	2KS1	A04
121VU	ENGINE/ENG1/FADEC B/AND EIU 1	4KS1	R41
FOR FIN: 1000EM2 (ENGINE2)
49VU	ENGINE/2/FADEC A/AND EIU 2	2KS2	A05
121VU	ENGINE/ENG2/FADEC B	4KS2	Q40

Subtask 75-31-00-860-054-A ** ON A/C NOT FOR ALL

E. On the left or right MCDU, get the AIDS menu page.

Subtask 75-31-00-710-055-A ** ON A/C NOT FOR ALL

F. Check of the Variable Bleed Valve (VBV) position (only with the Aircraft Integrated Data System (AIDS) option)
(1) On maintenance panel 50VU, push the ENG FADEC GND PWR 1 and 2 pushbutton switches (the ON legends come on).

ACTION	RESULT
On the MCDU:	On the MCDU display:
Push the MCDU MENU mode key.	The MCDU MENU page comes into view.
Push the line key adjacent to the < AIDS indication.	The AIDS page comes into view.
Push the line key adjacent to the PARAM ALPHA CALL-UP> indication.	The AIDS PARAM ALPHA CALL-UP page comes into view.
On the AIDS PARAM ALPHA CALL-UP page, enter ALPHA code VBV.	Make sure that the VBV is between -0.8 and 0 degrees. If the VBV is not between -0.8 and 0 degrees, do this task (Ref. AMM TASK 75-31-70-400-002) to correctly install the sensor. If the value that you read is between 54 and 64 degrees, this value is not correctly indicated by the AIDS. Do step (2) below to know the correct VBV position.

(2) If necessary, calculate the correct VBV value:
(a) Correct value = Read value - 64 degrees.
1 Example: If the AIDS displays 63.5 degrees:
63.5 - 64 = -0.5
The correct value is -0.5 degrees.

Subtask 75-31-00-410-078-A ** ON A/C NOT FOR ALL

G. Install the fan duct panels (Ref. AMM TASK 72-23-00-400-027).

5. Close-up
Subtask 75-31-00-410-079-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 75-31-00-440-061-A ** ON A/C NOT FOR ALL

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

Subtask 75-31-00-410-080-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 13:08:32 UTC