DOC AIRBUS | AMM A320FCheck/Adjustment of the NLG Extension/Steering Proximity Sensors with the Aircraft Weight on Wheels
TASK 32-31-73-820-006-A-01
Check/Adjustment of the NLG Extension/Steering Proximity Sensors with the Aircraft Weight on Wheels
To do a check and/or adjustment of proximity sensor 24GA (25GA) and its related targets with the aircraft weight on wheels with over-inflation of the shock absorber.
This task can be used to temporarily release the aircraft to service only for 50FC as an alternative to the AMM task 32-32-73-820-006-A
After 50FC:
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 32-31-73-941-067-A
(a) Connect one end of the nitrogen supply hose (16) to the nitrogen source (17).
(b) Connect the other end of the nitrogen supply hose (16) to the three-way valve (14).
(c) Connect one end of the filling hose (13) to the three-way valve (14).
(e) Connect the other end of the filling hose (13) to the end fitting (2) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (15) and (11) on the three-way valve (14).
(g) Slowly open the control valve (10) on the nitrogen source (17) to bleed the system through the CHARGING EQUIPMENT - FLUID, STANDARD.
(h) Close the control valve (10) on the nitrogen source (17).
(i) Close the control valves (11) and (15) on the three-way valve (14).
(2) Install the M21930 FILLING ASSEMBLY on the charging valve (4) as follows:
(a) Remove the blanking cap (5) from the charging valve (4).
(b) Move the wrench (9) up to the knurled shoulder (3) and install the M21930 FILLING ASSEMBLY on the charging valve (4).
(c) Turn the core (7) of the M21930 FILLING ASSEMBLY clockwise with the knurled shoulder (3).
(a) Make sure that the charging valve (4) and the control valve (15) on the three-way valve (14) are closed.
(b) Slowly open the control valve (11) on the three-way valve (14).
(c) Use the THERMOMETER-SURFACE CONTACT to measure the temperature of the NLG shock absorber adjacent to the charging valve (4). Record this temperature.
(d) Make sure that the THERMOMETER-SURFACE CONTACT touches the shock absorber outer-cylinder.
(f) Refer the NLG pressure/extension data (weight on wheels) to find the shock absorber charge-pressure for the recorded dimension H and temperature (Ref. AMM TASK 12-14-32-614-004).
(g) Slowly open the control valve (10) on the nitrogen source (17).
(h) Fill nitrogen until the pressure gage (12) shows the pressure of plus or minus 0.5 bar (7 psi) given in the NLG pressure/extension data (weight on wheels).
(i) Close the control valve (10) on the nitrogen source (17).
(j) Wait for a minimum of 5 minutes to let the pressure become stable.
(k) Make sure that there are no leaks in the CHARGING EQUIPMENT - FLUID, STANDARD.
(l) Close the control valve (11) on the three-way valve (14).
1 Slowly open the charging valve (4) with the M21930 FILLING ASSEMBLY.
2 Slowly open the control valve (11) on the three-way valve (14).
3 Read and record the pressure shown on the pressure gage (12).
4 Identify this pressure as "P CONST".
5 Use the THERMOMETER-SURFACE CONTACT to measure the temperature of the NLG shock absorber adjacent to the charging valve (4).
6 Make sure that the THERMOMETER-SURFACE CONTACT touches the shock absorber outer-cylinder.
8 Measure dimension H.
(c) Inflate the shock absorber with nitrogen until you get a dimension H of 444 +2 mm or -2 mm (17.480 +0.079 in. or -0.079 in.).
(d) Lift the NLG wheels as follows:
2 Lift the NLG wheels (Ref. AMM TASK 07-12-00-582-001).
(f) When the shock absorber extends to dimension H MAX, continue to inflate it until the pressure is equal to "P CONST" +40 bar (580 psi).
Subtask 32-31-73-820-063-A
Subtask 32-31-73-410-067-A
[Rev.10 from 2021]
2026.04.01 00:46:04 UTC
Check/Adjustment of the NLG Extension/Steering Proximity Sensors with the Aircraft Weight on Wheels
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:
MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR AND DOORS. MOVEMENT OF THE LANDING GEAR AND DOORS CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
WARNING:
OBEY THE HYDRAULIC SAFETY PROCEDURES.
WARNING:
DO NOT LET COMPRESSED GAS TOUCH YOUR SKIN. THE GAS CAN GO THROUGH THE SKIN AND MAKE BUBBLES IN THE BLOOD. THIS CONDITION CAN KILL YOU.
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.
CAUTION:
MAKE SURE THAT THE AIRCRAFT IS EMPTY OF ALL PERSONNEL. IF THERE ARE PERSONNEL IN THE AIRCRAFT, MAKE SURE THAT THEY DO NOT MOVE. MOVEMENT OF PERSONS IN THE AIRCRAFT CAN CAUSE INCORRECT CHECK/ADJUSTMENT OF THE PROXMITY SENSORS.
CAUTION:
MAKE SURE THAT YOU PUT THE WHEEL CHOCK(S) IN POSITION ONLY AT THE MLG WHEELS AND NOT AT THE NLG WHEELS. WHEEL CHOCKS INSTALLED AT THE NLG WHEELS CAN CAUSE BLOCKAGE TO THE SHOCK ABSORBER EXTENSION.
1. Reason for the JobTo do a check and/or adjustment of proximity sensor 24GA (25GA) and its related targets with the aircraft weight on wheels with over-inflation of the shock absorber.
This task can be used to temporarily release the aircraft to service only for 50FC as an alternative to the AMM task 32-32-73-820-006-A
After 50FC:
- You must do AMM task 32-31-73-820-006-A for the adjustment of the NLG extension/steering proximity sensors.
- You must do AMM task 12-12-32-610-001-A for a check of the NLG shock-absorber fluid level and charge pressure.
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 2M (6 FT) |
| No specific | 1 | CHARGING EQUIPMENT - FLUID, STANDARD |
| No specific | AR | CHOCK - WHEEL(S) |
| No specific | 1 | GAGE 200 BAR (2900 PSI) - PRESSURE |
| No specific | AR | SAFETY BARRIER(S) |
| No specific | 1 | THERMOMETER-SURFACE CONTACT |
| No specific | AR | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 0.85 and 0.5 m.daN (75.22 and 44.25 lbf.in )  | |
| 98D32203502000 | 2 | SAFETY PIN - NLG DOOR |
| D23156000 | 1 | PIN-SAFETY |
| M21930 | 1 | FILLING ASSEMBLY |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.03GBB1) | Synthetic Oil base Grease-General Purpose Clay Thickened - |
| (Material No.03HBD9) | Synthetic Ester base Grease-General Purpose Low Temp - |
| (Material No.14CCB6) | Testing Medium-Leak Detection - Oxygen System |
| (Material No.14VGC1) | Individual Compound-- Nitrogen Gaseous |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 711 | NOSE GEAR |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 05-57-00-200-001-A | Aircraft Stability |
| TASK 05-57-00-200-001-B | Aircraft Stability |
| TASK 05-57-00-200-001-C | Aircraft Stability |
| TASK 07-12-00-582-001-A | Jacking of the Nose Landing Gear |
| TASK 10-11-00-555-015-A | Procedure for the Installation of Wheel Chocks on Aircraft |
| TASK 12-11-28-650-003-A | Pressure Refuel with Automatic Control |
| TASK 12-14-32-614-004-A | Check of the NLG Shock Absorber Charge-Pressure |
| TASK 12-22-32-640-002-A | Lubrication of Nose Landing Gear and Doors |
| 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 29-10-00-863-001-A | Pressurize the Green Hydraulic System with a Hydraulic Ground Power-Cart |
| TASK 29-10-00-863-002-A | Pressurize the Yellow Hydraulic System with a Hydraulic Ground Power-Cart |
| TASK 29-10-00-864-001-A | Depressurize the Green Hydraulic System |
| TASK 29-10-00-864-002-A | Depressurize the Yellow Hydraulic System |
| TASK 31-36-00-740-008-A | Access to the Parameter Call-Up Menus |
| TASK 32-00-00-481-001-A | Installation of the Safety Devices on the Landing Gears |
| TASK 32-00-00-481-002-A | Installation of the Safety Devices on the Landing Gear Doors |
| TASK 32-22-00-010-001-A | Nose Gear Doors - Ground Doors Opening |
| TASK 32-22-00-410-001-A | Nose Gear Doors - Ground Doors Closing |
| TASK 32-31-73-200-002-A | Inspection of the NLG Proximity Sensor and Target Clearances |
| TASK 32-31-73-820-006-A | Adjustment of the NLG Extension/Steering Proximity Sensors |
Safety AreaSubtask 32-31-73-941-067-A
A. Safety Precautions
(1) Before you lift the aircraft, identify a safety area.
(3) Make sure that the safety devices are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(4) Make sure that the aircraft is parked on a flat surface.
(5) Put the CHOCK - WHEEL(S) at the MLG wheels (Ref. AMM TASK 10-11-00-555-015).
(a) Make sure that there is a clearance of approximately 25 mm (0.984 in.) between the forward chocks and the MLG wheels.
(6) On panel 400VU:
(a) Make sure that the landing-gear control-lever (6GA) is in the DOWN position.
(b) Put the WARNING NOTICE(S) in position to tell persons not to operate the landing-gear controls.
(7) Put the WARNING NOTICE(S) in position to tell persons not to operate the NLG doors.
Subtask 32-31-73-860-076-A (1) Before you lift the aircraft, identify a safety area.
NOTE: Local safety regulations can have more rules and information applicable to safety areas.
(2) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.(3) Make sure that the safety devices are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(4) Make sure that the aircraft is parked on a flat surface.
(5) Put the CHOCK - WHEEL(S) at the MLG wheels (Ref. AMM TASK 10-11-00-555-015).
(a) Make sure that there is a clearance of approximately 25 mm (0.984 in.) between the forward chocks and the MLG wheels.
(6) On panel 400VU:
(a) Make sure that the landing-gear control-lever (6GA) is in the DOWN position.
(b) Put the WARNING NOTICE(S) in position to tell persons not to operate the landing-gear controls.
(7) Put the WARNING NOTICE(S) in position to tell persons not to operate the NLG doors.
B. Aircraft Maintenance Configuration
(2) Make sure that the aircraft is stable (wheels on the ground) before you extend the shock absorber (Ref. AMM TASK 05-57-00-200-001).
(3) On panel 110VU, set the PARKING BRK control-switch to the OFF position.
Subtask 32-31-73-010-064-A WARNING:
BE CAREFUL IF ONLY ONE ENGINE IS INSTALLED. IT IS NOT PERMITTED TO LIFT THE AIRCRAFT WITH THIS PROCEDURE.
(1) If the engines are not installed on the aircraft, refuel the center tank (Ref. AMM TASK 12-11-28-650-003). (2) Make sure that the aircraft is stable (wheels on the ground) before you extend the shock absorber (Ref. AMM TASK 05-57-00-200-001).
(3) On panel 110VU, set the PARKING BRK control-switch to the OFF position.
C. Get Access
(2) Install the 98D32203502000 SAFETY PIN - NLG DOOR in the linkage of each forward NLG door (Ref. AMM TASK 32-00-00-481-002).
(3) Put the ACCESS PLATFORM 2M (6 FT) in position at the NLG.
Subtask 32-31-73-860-077-A WARNING:
MAKE SURE THAT THE TRAVEL RANGES OF THE LANDING GEAR DOORS ARE CLEAR.
(1) Open the NLG doors (Ref. AMM TASK 32-22-00-010-001). (2) Install the 98D32203502000 SAFETY PIN - NLG DOOR in the linkage of each forward NLG door (Ref. AMM TASK 32-00-00-481-002).
(3) Put the ACCESS PLATFORM 2M (6 FT) in position at the NLG.
D. Aircraft Maintenance Configuration
(1) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the Green, Blue and Yellow hydraulic systems.
(2) Lubricate the lower-bearing of the NLG leg barrel and the nose-wheel steering actuator (Ref. AMM TASK 12-22-32-640-002).
Subtask 32-31-73-080-050-A (1) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the Green, Blue and Yellow hydraulic systems.
(2) Lubricate the lower-bearing of the NLG leg barrel and the nose-wheel steering actuator (Ref. AMM TASK 12-22-32-640-002).
E. Removal of the Ground Support Equipment
(1) Make sure that the passenger/crew doors, the emergency exits and the cargo doors are closed and locked or fully open and locked.
(2) Remove the access platform(s).
(3) If the CHOCK - WHEEL(S) are installed at the NLG wheels, remove them.
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
4. Procedure(1) Make sure that the passenger/crew doors, the emergency exits and the cargo doors are closed and locked or fully open and locked.
(2) Remove the access platform(s).
(3) If the CHOCK - WHEEL(S) are installed at the NLG wheels, remove them.
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
NOTE: The aircraft must be stable and no persons must move in the aircraft during this procedure.
Subtask 32-31-73-820-060-A A. Alignment of the NLG Wheels to Zero Degree Position
(1) On right center instrument-panel 400VU, make sure that:
(3) If the NLG wheels are not aligned, do the steps that follow:
(a) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(b) On the NLG, make sure that the towing lever is in the normal (engaged) position.
(c) Make sure that the N/WS hand wheels and the rudder pedals are in the neutral position.
(d) Pressurize the Green or Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-001) (Ref. AMM TASK 29-10-00-863-002).
1 Put the ground-towing control lever to the towing position.
2 Install the D23156000 PIN-SAFETY.
(f) Depressurize the Green or Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-001) (Ref. AMM TASK 29-10-00-864-002).
(g) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
Subtask 32-31-73-614-050-A (1) On right center instrument-panel 400VU, make sure that:
- The landing-gear control-lever (6GA) is in the DOWN position
- The A/SKID & N/WS STRG switch is set to the ON position.
(3) If the NLG wheels are not aligned, do the steps that follow:
(a) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(b) On the NLG, make sure that the towing lever is in the normal (engaged) position.
(c) Make sure that the N/WS hand wheels and the rudder pedals are in the neutral position.
(d) Pressurize the Green or Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-001) (Ref. AMM TASK 29-10-00-863-002).
NOTE: The nose wheels must be at zero degree position.
(e) On N/WS deactivation electrical box 5GC: 1 Put the ground-towing control lever to the towing position.
2 Install the D23156000 PIN-SAFETY.
(f) Depressurize the Green or Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-001) (Ref. AMM TASK 29-10-00-864-002).
(g) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
WARNING:
MAKE SURE THAT THE STANDARD CHARGING EQUIPMENT IS SAFE AND THAT YOU CAN USE IT ABOVE 150 BAR (2175 PSI). THIS WILL PREVENT INJURY TO PERSONNEL AND/OR DAMAGE TO EQUIPMENT.
CAUTION:
ALWAYS ADD NITROGEN SLOWLY WHEN YOU PRESSURIZE THE SHOCK ABSORBER. IF YOU ADD THE NITROGEN TOO QUICKLY, THE TEMPERATURE WILL INCREASE AND HAVE AN EFFECT ON THE SHOCK ABSORBER PRESSURE.
CAUTION:
MAKE SURE THAT YOU REMOVE THE SAFETY STAY BEFORE YOU INFLATE THE NLG SHOCK ABSORBER. IF YOU INFLATE THE NLG SHOCK ABSORBER WITH THE SAFETY STAY INSTALLED, DAMAGE TO THE FUSELAGE CAN OCCUR.
B. Over-Inflation of the NLG Shock Absorber to Fully Extended Position NOTE: You must use Individual Compound-- Nitrogen Gaseous (Material No.14VGC1) when you fill the NLG shock absorber. This will keep the oxygen level low.
(1) Install the CHARGING EQUIPMENT - FLUID, STANDARD on the M21930 FILLING ASSEMBLY as follows: (a) Connect one end of the nitrogen supply hose (16) to the nitrogen source (17).
(b) Connect the other end of the nitrogen supply hose (16) to the three-way valve (14).
(c) Connect one end of the filling hose (13) to the three-way valve (14).
NOTE: The length of the filling hose (13) must not be more than 3 m (9.84 ft.).
(d) Remove the blanking cap (1) and the plug (6) from the M21930 FILLING ASSEMBLY. (e) Connect the other end of the filling hose (13) to the end fitting (2) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (15) and (11) on the three-way valve (14).
(g) Slowly open the control valve (10) on the nitrogen source (17) to bleed the system through the CHARGING EQUIPMENT - FLUID, STANDARD.
(h) Close the control valve (10) on the nitrogen source (17).
(i) Close the control valves (11) and (15) on the three-way valve (14).
CAUTION:
MAKE SURE THAT YOU USE A GAGE WITH THE SPECIFIED PRESSURE RANGE (0 BAR TO 200 BAR AND ACCURATE TO +/- 0.5 BAR). THIS IS NECESSARY TO GET AN ACCURATE PRESSURE MEASUREMENT.
(j) Install the GAGE 200 BAR (2900 PSI) - PRESSURE (12) on the three-way valve (14). (2) Install the M21930 FILLING ASSEMBLY on the charging valve (4) as follows:
(a) Remove the blanking cap (5) from the charging valve (4).
(b) Move the wrench (9) up to the knurled shoulder (3) and install the M21930 FILLING ASSEMBLY on the charging valve (4).
(c) Turn the core (7) of the M21930 FILLING ASSEMBLY clockwise with the knurled shoulder (3).
NOTE: This will install the seal (8) on the charging valve (4).
(3) Do a check of the CHARGING EQUIPMENT - FLUID, STANDARD for leaks as follows: (a) Make sure that the charging valve (4) and the control valve (15) on the three-way valve (14) are closed.
(b) Slowly open the control valve (11) on the three-way valve (14).
(c) Use the THERMOMETER-SURFACE CONTACT to measure the temperature of the NLG shock absorber adjacent to the charging valve (4). Record this temperature.
(d) Make sure that the THERMOMETER-SURFACE CONTACT touches the shock absorber outer-cylinder.
NOTE: If possible, you must measure the temperature at the top of the cylinder (through the vent hole) at the aft part of the main fitting.
(e) Measure and record dimension H of the shock absorber extension. (f) Refer the NLG pressure/extension data (weight on wheels) to find the shock absorber charge-pressure for the recorded dimension H and temperature (Ref. AMM TASK 12-14-32-614-004).
(g) Slowly open the control valve (10) on the nitrogen source (17).
(h) Fill nitrogen until the pressure gage (12) shows the pressure of plus or minus 0.5 bar (7 psi) given in the NLG pressure/extension data (weight on wheels).
(i) Close the control valve (10) on the nitrogen source (17).
(j) Wait for a minimum of 5 minutes to let the pressure become stable.
(k) Make sure that there are no leaks in the CHARGING EQUIPMENT - FLUID, STANDARD.
(l) Close the control valve (11) on the three-way valve (14).
CAUTION:
ALWAYS ADD NITROGEN SLOWLY WHEN YOU PRESSURIZE THE SHOCK ABSORBER. IF YOU ADD THE NITROGEN TOO QUICKLY, THE TEMPERATURE WILL INCREASE AND HAVE AN EFFECT ON THE SHOCK ABSORBER PRESSURE.
CAUTION:
OBEY THESE PRECAUTIONS TO LET THE NLG WHEELS MOVE FORWARD DURING THE SHOCK ABSORBER EXTENSION:
- MAKE SURE THAT THE AREA IN FRONT OF THE NLG IS CLEAR
- DO NOT PUT THE JACK BEFORE DIMENSION "H" IS 444 MM (17.4803 IN.).
CAUTION:
DURING THE PROCEDURE, MAKE SURE THAT THE PRESSURE IN THE SHOCK ABSORBER DOES NOT INCREASE TO MORE THAN + 50 BAR (+725 PSI) OF THE P CONSTANT. IF IT DOES, IT CAN CAUSE DAMAGE TO THE SHOCK ABSORBER.
(4) Inflate the NLG shock absorber as follows: NOTE: It is possible that the dimension H will not increase gradually, but can increase in steps because of the friction in the bearings. The indicated pressure will stay approximately constant at all the time the NLG extends, until the full extension of 449 +2 mm or -2 mm (17.677 +0.079 in. or -0.079 in.).
NOTE: Before the NLG extends to 449 +2 mm or -2 mm (17.677 +0.079 in. or -0.079 in.), if the pressure in the shock absorber increases by 20 bar (290 psi), stop inflation procedure and contact AIRBUS.
(a) Record the NLG shock absorber charge-pressure, temperature and dimension H as follows: 1 Slowly open the charging valve (4) with the M21930 FILLING ASSEMBLY.
2 Slowly open the control valve (11) on the three-way valve (14).
3 Read and record the pressure shown on the pressure gage (12).
4 Identify this pressure as "P CONST".
5 Use the THERMOMETER-SURFACE CONTACT to measure the temperature of the NLG shock absorber adjacent to the charging valve (4).
6 Make sure that the THERMOMETER-SURFACE CONTACT touches the shock absorber outer-cylinder.
NOTE: If possible, you must measure the temperature at the top of the cylinder (through the vent hole) at the aft part of the main fitting.
7 Record this temperature and identify it as "T CONST". 8 Measure dimension H.
NOTE: This dimension H will be used to get the initial position of the NLG shock absorber (not over-inflated).
(b) Slowly open the control valve (10) on the nitrogen source (17). (c) Inflate the shock absorber with nitrogen until you get a dimension H of 444 +2 mm or -2 mm (17.480 +0.079 in. or -0.079 in.).
(d) Lift the NLG wheels as follows:
NOTE: This will decrease the ground friction load on the tires and make self-adjustment of the wheels easy.
1 Apply Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) or Synthetic Oil base Grease-General Purpose Clay Thickened - (Material No.03GBB1) on the jacking dome of the jack. 2 Lift the NLG wheels (Ref. AMM TASK 07-12-00-582-001).
WARNING:
DURING THE OVER-INFLATION PROCEDURE, MAKE SURE THAT THERE IS NO MOVEMENT OF THE JACKING DOME IN ITS MATING CUP. IF THERE IS A MOVEMENT OF THE JACKING DOME, IMMEDIATELY STOP THE OVER-INFLATION PROCEDURE. MOVEMENT OF THE JACKING DOME CAN CAUSE INJURY TO THE PERSONS AND DAMAGE TO THE SHOCK ABSORBER.
(e) Slowly inflate the shock absorber until dimension H increases to 449 +2 mm or -2 mm (17.677 +0.079 in. or -0.079 in.). Identify this as "H MAX". (f) When the shock absorber extends to dimension H MAX, continue to inflate it until the pressure is equal to "P CONST" +40 bar (580 psi).
NOTE: The NLG shock absorber is in fully extended position at this time. The pressure of P CONST + 40 bar (580 psi) will make sure that:
- The shock absorber will stay in the fully extended position
- The NLG wheels are centered during adjustment/check of all the sensors for all the temperature changes.
C. Check/Adjustment of the NLG Proximity Sensors
(2) If the dimensions are incorrect, do the adjustment of proximity sensor 24GA (25GA) and the related targets (Ref. AMM TASK 32-31-73-820-006).
Subtask 32-31-73-710-055-A NOTE: It is not necessary to lift the aircraft on jacks. The shock absorber is already in its fully extended position on the ground.
(1) Do a dimensional check of proximity sensor 24GA (25GA) and the related targets (Ref. AMM TASK 32-31-73-200-002). (2) If the dimensions are incorrect, do the adjustment of proximity sensor 24GA (25GA) and the related targets (Ref. AMM TASK 32-31-73-820-006).
D. Test of the Landing-Gear Proximity Sensors
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Do a test of the landing-gear proximity sensors with the NLG extended:
(a) Do a check of LGCIU1 and LGCIU2 label 021 as follows:
1 Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).
Subtask 32-31-73-586-054-A (1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Do a test of the landing-gear proximity sensors with the NLG extended:
(a) Do a check of LGCIU1 and LGCIU2 label 021 as follows:
1 Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).
| ACTION | RESULT |
|---|---|
| 1.With the MCDU keyboard, on the AIDS PAR LAB CALL-UP page, enter the parameter labels with the alphanumeric keys. NOTE: The format is EQ/SYS/LAB/SDI.
NOTE: You can enter the two parameter labels, left for LGCIU1 and right for LGCIU2, on the same page. | |
| If 24GA senses the weight-off-wheels condition, bit 12 in the DATABITS column shows 0. |
| If 25GA senses the weight-off-wheels condition, bit 12 in the DATABITS column shows 0. |
E. Lowering of the NLG Wheels
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Carefully lower the NLG wheels on ground (Ref. AMM TASK 07-12-00-582-001).
Subtask 32-31-73-614-051-A (1) Make sure that the work area is clean and clear of tools and other items.
(2) Carefully lower the NLG wheels on ground (Ref. AMM TASK 07-12-00-582-001).
F. Deflation of the NLG Shock Absorber
(2) Slowly open the control valve (15) on the three-way valve (14).
(3) Deflate the shock absorber until dimension H is less than 10 mm (0.394 in.) of the initial dimension H recorded during step 4.B.(4).
(4) Inflate the NLG shock absorber to initial dimension H recorded during step 4.B.(4).
(5) If a temperature change occurs between inflation and deflation of the shock absorber:
(7) Remove the CHARGING EQUIPMENT - FLUID, STANDARD and the M21930 FILLING ASSEMBLY as follows:
(a) Close the control valve (11) on the three-way valve (14).
(b) Close the charging valve (4) with the M21930 FILLING ASSEMBLY.
(c) Close the control valve (10) on the nitrogen source (17).
(d) Slowly open the control valve (15) to release the pressure.
(e) Remove the nitrogen source (17) from the three-way valve (14).
(f) Remove the pressure gage (12).
(g) Remove the M21930 FILLING ASSEMBLY from the charging valve (4).
(8) TORQUE the charging valve nut (4) to between 0.85 and 0.5 m.daN (75.22 and 44.25 lbf.in ).
(9) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (4).
(10) Install the blanking cap (5) on the charging valve (4).
Subtask 32-31-73-710-056-A WARNING:
MAKE SURE THAT THERE ARE NO PERSONS OR EQUIPMENT IN THE TRAVEL AREA OF THE SHOCK ABSORBER BEFORE YOU DEFLATE IT. DURING THE DEFLATION, THE SHOCK ABSORBER CAN MOVE SUDDENLY. THIS CAN CAUSE INJURY TO PERSONNEL AND/OR DAMAGE TO EQUIPMENT.
WARNING:
MAKE SURE THAT YOU DO NOT DEFLATE THE SHOCK ABSORBER BELOW 20 BAR (290 PSI) LESS THAN THE SHOWN P CONSTANT. WAIT UNTIL THE AIRCRAFT STARTS TO GO DOWN THEN CONTINUE TO SLOWLY DEFLATE THE SHOCK ABSORBER. IF THE PRESSURE IS NOT SUFFICIENT, THERE IS A RISK OF INJURY TO PERSONNEL AND/OR DAMAGE TO EQUIPMENT.
CAUTION:
RELEASE THE PRESSURE IN THE SHOCK ABSORBER SLOWLY. IF YOU DO NOT DO IT SLOWLY, OIL CAN SPILL FROM THE SHOCK-ABSORBER CHARGING VALVE.
(1) Open the charging valve (4) with the M21930 FILLING ASSEMBLY. (2) Slowly open the control valve (15) on the three-way valve (14).
(3) Deflate the shock absorber until dimension H is less than 10 mm (0.394 in.) of the initial dimension H recorded during step 4.B.(4).
(4) Inflate the NLG shock absorber to initial dimension H recorded during step 4.B.(4).
(5) If a temperature change occurs between inflation and deflation of the shock absorber:
NOTE: Refer to the NLG pressure/extension data (weight on wheels) to inflate the NLG shock absorber to the correct dimension H (Ref. AMM TASK 12-14-32-614-004).
(6) Make sure that there is no leakage during deflation of the shock absorber. (7) Remove the CHARGING EQUIPMENT - FLUID, STANDARD and the M21930 FILLING ASSEMBLY as follows:
(a) Close the control valve (11) on the three-way valve (14).
(b) Close the charging valve (4) with the M21930 FILLING ASSEMBLY.
(c) Close the control valve (10) on the nitrogen source (17).
(d) Slowly open the control valve (15) to release the pressure.
(e) Remove the nitrogen source (17) from the three-way valve (14).
(f) Remove the pressure gage (12).
(g) Remove the M21930 FILLING ASSEMBLY from the charging valve (4).
(8) TORQUE the charging valve nut (4) to between 0.85 and 0.5 m.daN (75.22 and 44.25 lbf.in )
. (9) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (4).
(10) Install the blanking cap (5) on the charging valve (4).
G. Test of the Landing-Gear Proximity Sensors
(1) Do a test of the landing-gear proximity sensors with the NLG compressed as follows:
(a) Do a check of LGCIU1 and LGCIU2 label 021 as follows:
1 Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).
(2) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
5. Close-up(1) Do a test of the landing-gear proximity sensors with the NLG compressed as follows:
(a) Do a check of LGCIU1 and LGCIU2 label 021 as follows:
1 Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).
| ACTION | RESULT |
|---|---|
| 1.With the MCDU keyboard, on the AIDS PAR LAB CALL-UP page, enter the parameter labels with the alphanumeric keys: NOTE: The format is EQ/SYS/LAB/SDI.
NOTE: You can enter the two parameter labels, left for LGCIU1 and right for LGCIU2, on the same page. | |
| If 24GA senses the weight-on-wheels condition, bit 12 in the DATABITS column shows 1. |
| If 25GA senses the weight-on-wheels condition, bit 12 in the DATABITS column shows 1. |
Subtask 32-31-73-410-067-A
A. Close Access
(1) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from the NLG doors.
(2) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).
Subtask 32-31-73-942-065-A (1) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from the NLG doors.
(2) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).
B. Removal of Equipment
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the SAFETY BARRIER(S).
(3) Remove the WARNING NOTICE(S).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the SAFETY BARRIER(S).
(3) Remove the WARNING NOTICE(S).