Installation of the Feed Back Position Pick-Off Unit
TASK 27-51-19-400-001-A
Installation of the Feed Back Position Pick-Off Unit
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 27-51-19-860-051-A
Subtask 27-51-19-860-052-A
Subtask 27-51-19-410-050-A
[Rev.10 from 2021]
2026.03.31 23:52:38 UTC
Installation of the Feed Back Position Pick-Off Unit
WARNING:
PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:
- THE FLIGHT CONTROLS
- THE FLIGHT CONTROL SURFACES
- THE LANDING GEAR AND THE RELATED DOORS
- COMPONENTS THAT MOVE.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 3M (10 FT) |
| No specific | Torque wrench: range to between 0.96 and 0.87 m.daN (84.96 and 76.99 lbf.in ) ![]() | |
| 98D27803000000 | 1 | LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.06LCG9) | Non Hardening Jointing Putty-Medium Temp. Area - - |
| (Material No.08BAA9) | Non Aqueous Cleaner-General - - |
| (Material No.14SBA1) | Textile-Lint free Cotton - |
| (Material No.14VGE1) | Individual Compound-- Zinc Powder - |
| (Material No.666400) | ELECOLIT 414 |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 148 | MAIN GEAR WELL AND HYDRAULIC COMPARTMENT |
| 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 24-41-00-862-002-A | De-energize the Aircraft Electrical Circuits Supplied from the External Power |
| TASK 24-41-00-862-002-A-01 | De-energize the Aircraft Electrical Circuits Supplied from the APU |
| TASK 24-41-00-862-002-A-02 | De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2) |
| TASK 27-00-00-080-002-A | Removal of the Flap/Slat Control-Lever Locking Tool (98D27803000000) |
| TASK 27-00-00-480-002-A | Installation of the Flap/Slat Control-Lever Locking Tool (98D27803000000) |
| TASK 27-50-00-866-009-A | Retraction of the Flaps on the Ground |
| TASK 27-50-00-866-009-A-01 | Retraction of the Flaps/Slats on the Ground |
| TASK 27-54-00-710-001-A | Operational Test of the Flap System |
| TASK 27-54-00-820-001-A | Adjustment of the Flap Drive System |
| TASK 31-32-00-860-006-A | Procedure to Get Access to the SYSTEM REPORT/TEST F/CTL Page |
| TASK 32-12-00-010-001-A | Open the Main Gear Doors for Access |
| TASK 32-12-00-410-001-A | Close the Main Gear Doors after Access |
Subtask 27-51-19-860-051-A
A. Aircraft Maintenance Configuration
(1) Make sure that the main doors of the main gear are open (Ref. AMM TASK 32-12-00-010-001).
(2) Make sure that the ACCESS PLATFORM 3M (10 FT) is in position at the opening of the main door of the main gear.
(3) Make sure that the flaps are in the retracted position (Ref. AMM TASK 27-50-00-866-009) because a new FPPU is delivered locked in its zero position.
(4) Make sure that the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION is installed on the slat/flap control lever (Ref. AMM TASK 27-00-00-480-002).
Subtask 27-51-19-865-051-A (1) Make sure that the main doors of the main gear are open (Ref. AMM TASK 32-12-00-010-001).
(2) Make sure that the ACCESS PLATFORM 3M (10 FT) is in position at the opening of the main door of the main gear.
(3) Make sure that the flaps are in the retracted position (Ref. AMM TASK 27-50-00-866-009) because a new FPPU is delivered locked in its zero position.
(4) Make sure that the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION is installed on the slat/flap control lever (Ref. AMM TASK 27-00-00-480-002).
B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
4. Procedure| PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B07 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B02 |
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/FLP/CTL AND/MONG/SYS2 | 8CV | Q21 |
Subtask 27-51-19-860-052-A
A. Preparation for Installation
(1) Do an inspection of the component interfaces and the adjacent area.
(2) Use a Textile-Lint free Cotton - (Material No.14SBA1) and the Non Aqueous Cleaner-General - - (Material No.08BAA9) to clean the:
(4) Apply a quantity of the prepared mixture or apply Elecolit 414 to the related electrical bonding areas (refer to the related figure):
(a) Make sure that you apply the material on the mating areas on the FPPU and on the differential gearbox.
(5) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the threads of the screws (1).
Subtask 27-51-19-420-050-A (1) Do an inspection of the component interfaces and the adjacent area.
(2) Use a Textile-Lint free Cotton - (Material No.14SBA1) and the Non Aqueous Cleaner-General - - (Material No.08BAA9) to clean the:
- mating area of the FPPU
- mating area of the differential gearbox.
(4) Apply a quantity of the prepared mixture or apply Elecolit 414 to the related electrical bonding areas (refer to the related figure):
(a) Make sure that you apply the material on the mating areas on the FPPU and on the differential gearbox.
(5) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the threads of the screws (1).
B. Installation of the Feed Back Position Pick-Off Unit
(1) Make sure that all zero marks on the FPPU are aligned.
(2) Remove the tie-wrap (3).
(3) Install the FPPU carefully on the gearbox.
(4) Install the screws (1) and the washers (2).
(5) TORQUE the screws (1) to between 0.96 and 0.87 m.daN (84.96 and 76.99 lbf.in )
.
(6) Do a bonding test between the main bonding point of the power control unit and the FPPU flange. The resistance must not be more than 20 milliohms.
(7) Remove the blanking caps from the electrical connectors.
(8) Make sure that all the electrical connections are clean and in the correct condition.
(9) Connect the electrical connectors 27CV-A and 27CV-B to the FPPU.
Subtask 27-51-19-865-052-A (1) Make sure that all zero marks on the FPPU are aligned.
(2) Remove the tie-wrap (3).
(3) Install the FPPU carefully on the gearbox.
(4) Install the screws (1) and the washers (2).
(5) TORQUE the screws (1) to between 0.96 and 0.87 m.daN (84.96 and 76.99 lbf.in )
. (6) Do a bonding test between the main bonding point of the power control unit and the FPPU flange. The resistance must not be more than 20 milliohms.
(7) Remove the blanking caps from the electrical connectors.
(8) Make sure that all the electrical connections are clean and in the correct condition.
(9) Connect the electrical connectors 27CV-A and 27CV-B to the FPPU.
C. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 27-51-19-740-050-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B07 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1 | 6CV | B02 |
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/FLP/CTL AND/MONG/SYS2 | 8CV | Q21 |
D. Do a Check of the Position Pick-Off Units (PPUs) on the Centralized Fault Display-System (CFDS)
(1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) Remove the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION from the slat/flap control lever (Ref. AMM TASK 27-00-00-080-002).
(3) Get access to the SYSTEM REPORT/TEST (F/CTL) page on the Multipurpose Control Display-Unit (MCDU) (Ref. AMM TASK 31-32-00-860-006).
(4) Do a check of the flap PPU angles (deg) at the slat/flap control lever position ZERO on the MCDU as follows:
(5) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
Subtask 27-51-19-820-050-A (1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) Remove the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION from the slat/flap control lever (Ref. AMM TASK 27-00-00-080-002).
(3) Get access to the SYSTEM REPORT/TEST (F/CTL) page on the Multipurpose Control Display-Unit (MCDU) (Ref. AMM TASK 31-32-00-860-006).
(4) Do a check of the flap PPU angles (deg) at the slat/flap control lever position ZERO on the MCDU as follows:
| ACTION | RESULT |
|---|---|
1.On the MCDU:
| On the MCDU:
|
| 2.Push (in) the NEXT PAGE button. |
|
| 3.Push (in) the line key SYSTEM DATA FLP >. |
|
| 4.Push (in) the line key < PPU. |
NOTE: The APPU and the FPPU synchro angles must not be different by more than 1.3 deg. The LH APPU and the RH APPU synchro angles must not be different by more than 0.7 deg. |
| 5.Push the line key < RETURN frequently until the CFDS menu page is shown. | |
| ------------------------------------------------------------------------------- |
| ! ! |
| ! SFCC 1 ! |
| ! PPU DATE (DEG) ! |
| ! DATE:XXX XX UTC:XXXX ! |
| ! LH APPU FPPU RH APPU ! |
| ! ***.* ***.* ***.* ! |
| ! ***HEX ***HEX ***HEX *** ! |
| !-----------------------------------------------------------------------------! |
| ! OTHER SFCC ! |
| ! LH APPU FPPU RH APPU ! |
| ! ***.* ***.* ***.* *** ! |
| ! ***HEX ***HEX ***HEX ! |
| !-----------------------------------------------------------------------------! |
| ! <RETURN PRINT> ! |
| !-----------------------------------------------------------------------------! |
| ! Table 1 ! |
| ! PPU DATA (DEG) displayed on the MCDU at the flap position ZERO ! |
| ! ! |
| ------------------------------------------------------------------------------- |
E. Adjustment
Subtask 27-51-19-710-050-A 5. Close-upNOTE: The difference between the LH APPU and the FPPU must be in the limits plus or minus 1.3 deg maximum). The difference between the RH APPU and the FPPU must be in the limits (plus or minus 1.3 deg maximum). The difference between the LH APPU and the RH APPU must be in the limits (plus or minus 0.7 deg maximum).
(1) If necessary, do an adjustment of the flap drive system (Ref. AMM TASK 27-54-00-820-001). Subtask 27-51-19-410-050-A
A. Close Access
(1) Remove the access platform(s).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the main doors of the main gear (Ref. AMM TASK 32-12-00-410-001).
(1) Remove the access platform(s).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the main doors of the main gear (Ref. AMM TASK 32-12-00-410-001).
Electrical Bonding Area of the FPPU