DOC AIRBUS | AMM A320FInstallation of the MLG Uplock Assembly
TASK 32-31-44-400-001-A
Installation of the MLG Uplock Assembly
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Expendable Parts
D. Referenced Information
3. Job Set-up
Subtask 32-31-44-860-051-A
Subtask 32-31-44-420-050-A
Subtask 32-31-44-410-051-A
[Rev.10 from 2021]
2026.04.01 00:45:22 UTC
Installation of the MLG Uplock Assembly
WARNING:
MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.
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:
OBEY THE HYDRAULIC SAFETY PROCEDURES.
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 | CONTAINER - HYDRAULIC FLUID RESISTANT |
| No specific | 2 | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 1.63 and 1.52 m.daN (12.02 and 11.21 lbf.ft )  | |
| No specific | Torque wrench: range to between 7.8 and 6.8 m.daN (57.52 and 50.15 lbf.ft ) | |
| No specific | Torque wrench: range to between 15.33 and 13.87 m.daN (113.05 and 102.29 lbf.ft ) | |
| 98DNSA20208060 | 2 | RIGGING PIN |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.04JMD9) | Top Coat Polyurethane-- Decorative Furnishing |
| (Material No.06LCG9) | Non Hardening Jointing Putty-Medium Temp. Area - - |
| (Material No.08BBB1) | Non Aqueous Cleaner-- Petroleum Based - |
| (Material No.14QFB1) | Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 32 | COTTER PIN | AIPC 32-31-03-22-060 |
| 3 | COTTER PIN | AIPC 32-31-03-22-120 |
| 15 | COTTER PIN | AIPC 32-31-03-22-260 |
| 28 | COTTER PIN | AIPC 32-31-03-22-260 |
| 32 | COTTER PIN | AIPC 32-31-83-40-070 |
| 15 | COTTER PIN | AIPC 32-31-83-40-170 |
| 28 | COTTER PIN | AIPC 32-31-83-40-170 |
| 3 | COTTER PIN | AIPC 32-31-83-40-320 |
| 38 | COTTER PIN | AIPC 32-33-03-01-170 |
| 38 | COTTER PIN | AIPC 32-33-83-01-020 |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 12-12-29-611-001-A | Fill the Hydraulic Fluid Reservoir with a Hand Pump |
| TASK 20-28-00-912-802-A | Electrical Bonding - General Maintenance Procedure |
| 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 29-00-00-910-002-A | Safety Procedures of the Hydraulic System |
| TASK 29-10-00-864-001-A | Depressurize the Green Hydraulic System |
| TASK 29-14-00-614-001-A | Depressurization of the Hydraulic Reservoirs |
| TASK 29-23-00-860-001-A | Disconnection of the Isolation Coupling of the Power Transfer Unit (PTU) |
| TASK 29-23-00-860-002-A | Connection of the Isolation Coupling of the Power Transfer Unit (PTU) |
| TASK 32-00-00-860-001-A | Flight Configuration Precautions with Electrical Power |
| TASK 32-00-00-860-001-A-01 | Flight Configuration Precautions without Electrical Power |
| TASK 32-00-00-860-002-A | Ground Configuration after Flight Configuration with Electrical Power |
| TASK 32-00-00-860-002-A-01 | Ground Configuration after Flight Configuration without Electrical Power |
| 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 |
| TASK 32-31-00-720-002-A | Functional Test of the Normal Extension and Retraction of the Landing Gear |
| TASK 32-33-00-720-001-A | Functional Check of Free-Fall Extension |
| TASK 51-75-13-916-002-A | Repair to a layer of Corrosion Preventive Compound |
MLG Uplock Assembly 2509GM (2510GM)Subtask 32-31-44-860-051-A
A. Aircraft Maintenance Configuration
(1) Make sure that the PTU isolation coupling is disconnected (Ref. AMM TASK 29-23-00-860-001).
(2) Make sure that the aircraft electrical circuits are energized (Ref. AMM TASK 24-41-00-861-002).
(3) Make sure that the flight configuration precautions were obeyed (Ref. AMM TASK 32-00-00-860-001).
(4) Make sure that the Green hydraulic system is depressurized (Ref. AMM TASK 29-10-00-864-001).
(5) Make sure that the reservoir of the Green hydraulic system is depressurized (Ref. AMM TASK 29-14-00-614-001).
Subtask 32-31-44-865-051-A (1) Make sure that the PTU isolation coupling is disconnected (Ref. AMM TASK 29-23-00-860-001).
(2) Make sure that the aircraft electrical circuits are energized (Ref. AMM TASK 24-41-00-861-002).
(3) Make sure that the flight configuration precautions were obeyed (Ref. AMM TASK 32-00-00-860-001).
(4) Make sure that the Green hydraulic system is depressurized (Ref. AMM TASK 29-10-00-864-001).
(5) Make sure that the reservoir of the Green hydraulic system is depressurized (Ref. AMM TASK 29-14-00-614-001).
B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
Subtask 32-31-44-941-052-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | L/G/LGCIU/SYS1/NORM | 1GA | C09 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | HYDRAULIC/G HYD/PUMP ENG1/CTL | 1701GK | H12 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/G HYD/PUMP ENG1/CTL | 1701GK | R35 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/G HYD/PUMP ENG1/MONG | 1702GK | R34 |
| ** ON A/C ALL | |||
| 121VU | HYDRAULIC/LGCIU/SYS2 | 2GA | Q35 |
| 121VU | HYDRAULIC/LGCIU/SYS1/GRND SPLY | 52GA | Q34 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/G HYD/PUMP ENG1/MONG | 1702GK | R33 |
C. Safety Precautions
(1) Make sure that the WARNING NOTICE(S) are in position to tell persons not to pressurize the Green hydraulic system:
Subtask 32-31-44-560-050-A (1) Make sure that the WARNING NOTICE(S) are in position to tell persons not to pressurize the Green hydraulic system:
- On the panel 40VU in the cockpit
- On the ground service panel of the Green hydraulic system.
D. Preparation of the Replacement Component
(1) View D
(a) Remove and discard the cotter pin (32) from the removed uplock assembly (8).
(b) Remove the nut (31), the washer (30), the bolt (39) and remove the lever (29) from the uplock assembly (8).
(c) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the splined shaft of the new uplock assembly (8), the bolt (39) and the washer (30).
(d) Put the lever (29) in position on the splined shaft of the uplock assembly (8). Make sure that the master splines are aligned.
(e) Install the bolt (39), the washer (30) and the nut (31).
(f) Safety the nut (31) with a new AIPC 32-31-03-22-060 COTTER PIN (32) or AIPC 32-31-83-40-070 COTTER PIN (32).
(2) Make sure that the dimension "X" of the new component is the same of that retained from the removed component.
(3) If necessary adjust to "Dimension X":
(b) Loosen the eye end-lock nut.
(c) Turn the eye end in or out until the "Dimension X" is reached.
(d) Tighten the eye end-lock nut and TORQUE to between 15.33 and 13.87 m.daN (113.05 and 102.29 lbf.ft ).
(e) Safety the eye end with14QFB1 Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -
Subtask 32-31-44-560-051-A (1) View D
(a) Remove and discard the cotter pin (32) from the removed uplock assembly (8).
(b) Remove the nut (31), the washer (30), the bolt (39) and remove the lever (29) from the uplock assembly (8).
(c) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the splined shaft of the new uplock assembly (8), the bolt (39) and the washer (30).
(d) Put the lever (29) in position on the splined shaft of the uplock assembly (8). Make sure that the master splines are aligned.
(e) Install the bolt (39), the washer (30) and the nut (31).
(f) Safety the nut (31) with a new AIPC 32-31-03-22-060 COTTER PIN (32) or AIPC 32-31-83-40-070 COTTER PIN (32).
(2) Make sure that the dimension "X" of the new component is the same of that retained from the removed component.
(3) If necessary adjust to "Dimension X":
WARNING:
USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.
(a) Cut and remove the lockwire from the eye end-lock nut. (b) Loosen the eye end-lock nut.
(c) Turn the eye end in or out until the "Dimension X" is reached.
(d) Tighten the eye end-lock nut and TORQUE to between 15.33 and 13.87 m.daN (113.05 and 102.29 lbf.ft )
. (e) Safety the eye end with
E. Preparation for Installation
(1) Clean the mating surfaces with Non Aqueous Cleaner-- Petroleum Based - (Material No.08BBB1) and dry them with filtered compressed air.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.
4. Procedure(1) Clean the mating surfaces with Non Aqueous Cleaner-- Petroleum Based - (Material No.08BBB1) and dry them with filtered compressed air.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.
Subtask 32-31-44-420-050-A
A. Installation of the MLG Uplock Assembly 2509GM (2510GM)
(1) Install the MLG Uplock Assembly (8) view B:
(a) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (11), the bushes (1) and the washer (12).
(b) If removed, install the inner bush (1).
(c) Put the uplock assembly (8) in position on the aircraft structure.
(d) Install the outer bush (1), the washer (12), the bolt (11) and the nut (2).
(e) TORQUE the nut (2) to between 7.8 and 6.8 m.daN (57.52 and 50.15 lbf.ft ) .
(f) Safety the nut (2) with a new AIPC 32-31-03-22-120 COTTER PIN (3) or AIPC 32-31-83-40-320 COTTER PIN (3).
(2) Install the Strut A (4) view E:
(a) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (20) and the washer assembly (19), the washers (18) and (17).
(b) Put the washer assembly (19) and the strut (4) in position.
(c) Install the bolt (20), the washer (18), (17) and the nut (16).
(d) Safety the nut (16) with a new AIPC 32-31-03-22-260 COTTER PIN (15) or AIPC 32-31-83-40-170 COTTER PIN (15).
(e) Put the bonding strap (13) in position and install the bolt (14), the washer (22) and the nut (21) (Ref. AMM TASK 20-28-00-912-802).
(3) Install the Strut B (10) view F:
(a) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (23) and the washers (25), (26) and the washer assembly (24).
(b) Put the washer assembly (24) and the strut (10) in position and install the bolt (23), the washers (25), (26) and the nut (27).
(c) Safety the nut (27) with a new AIPC 32-31-03-22-260 COTTER PIN (28) or AIPC 32-31-83-40-170 COTTER PIN (28).
(4) Install the Hydraulic hoses view B:
(a) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(b) Remove the blanking plugs and connect the hydraulic hoses (7) and (9) to the uplock assembly (8) TORQUE the connections to between 1.63 and 1.52 m.daN (12.02 and 11.21 lbf.ft ).
(c) Mark the connections with Top Coat Polyurethane-- Decorative Furnishing (Material No.04JMD9) .
(d) Remove the blanking caps from the electrical connectors.
(e) Make sure that all the electrical connections are clean and in the correct condition.
(f) Connect the electrical connectors (5) and (6) to the uplock assembly (8).
(5) Install the Free Fall Extension Rod (35) view D:
(a) Install the 98DNSA20208060 RIGGING PIN at rigging points 1 and 2.
(b) If necessary, adjust the adjustable rod (35) as follows:
2 Release the lockwashers (40) and adjust the length of the rod (35).
3 Make sure that all the installed rigging pins can be moved freely and easily.
4 Install the nuts (41) and safety with lockwire14QFB1 Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -
(c) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (33), the bush (34) and the washer (37).
(d) Put the rod (35) in position and install the bush (34), the bolt (33), the washer (37) and the nut (36).
(e) Safety the nut (36) with a new AIPC 32-33-03-01-170 COTTER PIN (38) or AIPC 32-33-83-01-020 COTTER PIN (38).
(f) Remove the rigging pins at rigging points 1 and 2.
Subtask 32-31-44-865-052-A (1) Install the MLG Uplock Assembly (8) view B:
(a) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (11), the bushes (1) and the washer (12).
(b) If removed, install the inner bush (1).
(c) Put the uplock assembly (8) in position on the aircraft structure.
(d) Install the outer bush (1), the washer (12), the bolt (11) and the nut (2).
(e) TORQUE the nut (2) to between 7.8 and 6.8 m.daN (57.52 and 50.15 lbf.ft )
. (f) Safety the nut (2) with a new AIPC 32-31-03-22-120 COTTER PIN (3) or AIPC 32-31-83-40-320 COTTER PIN (3).
(2) Install the Strut A (4) view E:
(a) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (20) and the washer assembly (19), the washers (18) and (17).
(b) Put the washer assembly (19) and the strut (4) in position.
(c) Install the bolt (20), the washer (18), (17) and the nut (16).
(d) Safety the nut (16) with a new AIPC 32-31-03-22-260 COTTER PIN (15) or AIPC 32-31-83-40-170 COTTER PIN (15).
(e) Put the bonding strap (13) in position and install the bolt (14), the washer (22) and the nut (21) (Ref. AMM TASK 20-28-00-912-802).
(3) Install the Strut B (10) view F:
(a) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (23) and the washers (25), (26) and the washer assembly (24).
(b) Put the washer assembly (24) and the strut (10) in position and install the bolt (23), the washers (25), (26) and the nut (27).
(c) Safety the nut (27) with a new AIPC 32-31-03-22-260 COTTER PIN (28) or AIPC 32-31-83-40-170 COTTER PIN (28).
(4) Install the Hydraulic hoses view B:
(a) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(b) Remove the blanking plugs and connect the hydraulic hoses (7) and (9) to the uplock assembly (8) TORQUE the connections to between 1.63 and 1.52 m.daN (12.02 and 11.21 lbf.ft )
. (c) Mark the connections with Top Coat Polyurethane-- Decorative Furnishing (Material No.04JMD9) .
(d) Remove the blanking caps from the electrical connectors.
(e) Make sure that all the electrical connections are clean and in the correct condition.
(f) Connect the electrical connectors (5) and (6) to the uplock assembly (8).
(5) Install the Free Fall Extension Rod (35) view D:
(a) Install the 98DNSA20208060 RIGGING PIN at rigging points 1 and 2.
(b) If necessary, adjust the adjustable rod (35) as follows:
WARNING:
USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.
1 Remove and discard the lockwire and loosen the nuts (41). 2 Release the lockwashers (40) and adjust the length of the rod (35).
3 Make sure that all the installed rigging pins can be moved freely and easily.
4 Install the nuts (41) and safety with lockwire
(c) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the bolt (33), the bush (34) and the washer (37).
(d) Put the rod (35) in position and install the bush (34), the bolt (33), the washer (37) and the nut (36).
(e) Safety the nut (36) with a new AIPC 32-33-03-01-170 COTTER PIN (38) or AIPC 32-33-83-01-020 COTTER PIN (38).
(f) Remove the rigging pins at rigging points 1 and 2.
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 32-31-44-860-052-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | L/G/LGCIU/SYS1/NORM | 1GA | C09 |
| ** ON A/C NOT FOR ALL | |||
| 49VU | HYDRAULIC/G HYD/PUMP ENG1/CTL | 1701GK | H12 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/G HYD/PUMP ENG1/CTL | 1701GK | R35 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/G HYD/PUMP ENG1/MONG | 1702GK | R34 |
| ** ON A/C ALL | |||
| 121VU | HYDRAULIC/LGCIU/SYS2 | 2GA | Q35 |
| 121VU | HYDRAULIC/LGCIU/SYS1/GRND SPLY | 52GA | Q34 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | HYDRAULIC/G HYD/PUMP ENG1/MONG | 1702GK | R33 |
C. Preparation for Test
(1) Connect the PTU isolation coupling (Ref. AMM TASK 29-23-00-860-002).
(2) If the flight configuration precautions were obeyed, put the aircraft back to the serviceable condition (Ref. AMM TASK 32-00-00-860-002).
(3) Remove the CONTAINER - HYDRAULIC FLUID RESISTANT.
(4) Remove the access platform(s).
(5) Remove the WARNING NOTICE(S).
(6) Make sure that the work area is clean and clear of tools and other items.
(7) Close the applicable MLG door (Ref. AMM TASK 32-12-00-410-001).
(8) If necessary fill the reservoir of the Green hydraulic system to the correct level (Ref. AMM TASK 12-12-29-611-001).
Subtask 32-31-44-720-050-A (1) Connect the PTU isolation coupling (Ref. AMM TASK 29-23-00-860-002).
(2) If the flight configuration precautions were obeyed, put the aircraft back to the serviceable condition (Ref. AMM TASK 32-00-00-860-002).
(3) Remove the CONTAINER - HYDRAULIC FLUID RESISTANT.
(4) Remove the access platform(s).
(5) Remove the WARNING NOTICE(S).
(6) Make sure that the work area is clean and clear of tools and other items.
(7) Close the applicable MLG door (Ref. AMM TASK 32-12-00-410-001).
(8) If necessary fill the reservoir of the Green hydraulic system to the correct level (Ref. AMM TASK 12-12-29-611-001).
D. Do the Test
(1) Do the functional test of the MLG (Ref. AMM TASK 32-31-00-720-002).
(2) Do the functional test of the free-fall extension system of the MLG (Ref. AMM TASK 32-33-00-720-001).
(3) Open the applicable MLG door (Ref. AMM TASK 32-12-00-010-001).
(4) Make sure that there is no hydraulic fluid leakage from the uplock assembly.
5. Close-up(1) Do the functional test of the MLG (Ref. AMM TASK 32-31-00-720-002).
(2) Do the functional test of the free-fall extension system of the MLG (Ref. AMM TASK 32-33-00-720-001).
(3) Open the applicable MLG door (Ref. AMM TASK 32-12-00-010-001).
(4) Make sure that there is no hydraulic fluid leakage from the uplock assembly.
Subtask 32-31-44-410-051-A
A. Close Access
(1) Apply corrosion protection to the nuts, bolts, washers, hydraulic pipes and adjacent areas (Ref. AMM TASK 51-75-13-916-002).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the applicable MLG door (Ref. AMM TASK 32-12-00-410-001).
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(1) Apply corrosion protection to the nuts, bolts, washers, hydraulic pipes and adjacent areas (Ref. AMM TASK 51-75-13-916-002).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the applicable MLG door (Ref. AMM TASK 32-12-00-410-001).
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.