DOC AIRBUS | AMM A320FCheck NLG Shock Absorber Fluid Level and Charge Pressure ("Two-Point Check" - Aircraft on Jacks to start)
TASK 12-12-32-610-001-A
Check NLG Shock Absorber Fluid Level and Charge Pressure ("Two-Point Check" - Aircraft on Jacks to start)
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 12-12-32-941-073-A
Subtask 12-12-32-582-056-A
Subtask 12-12-32-410-054-A
[Rev.10 from 2021]
2026.03.31 22:54:51 UTC
Check NLG Shock Absorber Fluid Level and Charge Pressure ("Two-Point Check" - Aircraft on Jacks to start)
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.
ZONE: 711
1. Reason for the JobNOTE: The NLG shock absorber fluid level and charge pressure must be measured with the aircraft lifted on jacks and on the ground. This procedure does the aircraft-on-jacks check first and then the on-ground check. If necessary, the on-ground check can be done first followed by the on-jacks check, refer to Task 12-12-32-610-001-A01.
NOTE: This procedure can be done with the aircraft fully lifted on jacks (Ref. Task 07-11-00-581-001-A) or lifted at the forward jacking point (Ref. Task 07-11-00-581-003-A).
NOTE: This procedure must be done a minimum of 2 hours after the last aircraft operation. This will make sure that the shock absorber values recorded are accurate.
NOTE: As an alternative procedure to check the NLG shock absorber fluid level and charge pressure, you can do Task 12-12-32-610-002-A or Task 12-12-32-610-002-A01. If you do Task 12-12-32-610-002-A or Task 12-12-32-610-002-A01, it is not necessary for the aircraft to be on jacks.
2. Job Set-up InformationA. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 2M (6 FT) |
| No specific | AR | CHARGING EQUIPMENT - FLUID, STANDARD |
| No specific | 1 | GAGE 0 TO 2000 PSI (0 TO 138 BAR) - PRESSURE |
| No specific | 1 | GAGE 200 BAR (2900 PSI) - PRESSURE |
| No specific | AR | NITROGEN COMPRESSED SOURCE - GROUND |
| No specific | 1 | RULER - STEEL |
| No specific | AR | SAFETY BARRIER(S) |
| No specific | 2 | THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) |
| No specific | 1 | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in )  | |
| 98D32203502000 | 2 | SAFETY PIN - NLG DOOR |
| M21930 | 1 | FILLING ASSEMBLY |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.14CCB6) | Testing Medium-Leak Detection - Oxygen System |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 711 | NOSE GEAR |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 07-11-00-581-001-A | Lifting for Aircraft Maintenance Operations |
| TASK 07-11-00-581-003-A | Lifting of the Aircraft at the Forward Jacking Point, MLG Wheels on the Ground |
| TASK 07-11-00-586-001-A | Lowering of the Aircraft at Forward Jacking Point, MLG Wheels on the Ground |
| TASK 07-11-00-586-002-A | Lowering of the Aircraft for Maintenance Operations |
| TASK 12-12-32-611-001-A | NLG Shock Absorber Oil Replenishment and Nitrogen Filling (Aircraft on Wheels) |
| 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 |
Subtask 12-12-32-941-073-A
A. Safety Precautions
(1) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(2) Make sure that the ground safety locks are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(3) On panel 400VU, make sure that the landing-gear control-lever 6GA is in the DOWN position.
(4) Put a WARNING NOTICE(S) on panel 400VU, to tell persons not to operate the landing-gear controls.
(5) Put a WARNING NOTICE(S) in position to tell persons not to operate the NLG doors.
Subtask 12-12-32-010-054-A (1) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(2) Make sure that the ground safety locks are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(3) On panel 400VU, make sure that the landing-gear control-lever 6GA is in the DOWN position.
(4) Put a WARNING NOTICE(S) on panel 400VU, to tell persons not to operate the landing-gear controls.
(5) Put a WARNING NOTICE(S) in position to tell persons not to operate the NLG doors.
B. 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.
4. ProcedureWARNING:
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.
Subtask 12-12-32-582-056-A
A. Lift the Aircraft on Jacks
(1) Lift the aircraft on jacks (Ref. AMM TASK 07-11-00-581-001) or (Ref. AMM TASK 07-11-00-581-003).
Subtask 12-12-32-614-080-A (1) Lift the aircraft on jacks (Ref. AMM TASK 07-11-00-581-001) or (Ref. AMM TASK 07-11-00-581-003).
B. Adjust the Charge Pressure of the NLG Shock Absorber (Aircraft on Jacks)
(1) Make sure that the shock absorber is fully extended. Dimension H must be between 447 mm (17.5984 in.) and 451 mm (17.7559 in.).
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
(a) Connect the nitrogen source hose (18) to the NITROGEN COMPRESSED SOURCE - GROUND.
(b) Connect the nitrogen source hose (18) to the three-way valve (12).
(c) Connect the filling hose (11) to the three-way valve (12).
(e) Connect the filling hose (11) to the end fitting (2) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (13) and (19) on the three-way valve (12) and the control valve of the nitrogen source. Blow nitrogen through the charging equipment to bleed the system with nitrogen.
(g) Close the control valves (13) and (19) on the three-way valve (12) and the control valve of the nitrogen source.
(3) Install the M21930 FILLING ASSEMBLY on the charging valve (6) as follows:
(a) Remove the blanking cap (7) from the charging valve (6).
(b) Move the wrench (9) up to the knurled shoulder (3) and install the M21930 FILLING ASSEMBLY on the charging valve (6).
(c) Turn the core (8) of the M21930 FILLING ASSEMBLY clockwise with the knurled shoulder (3). This will install the seal (4) on the charging valve (6).
(4) Do a check of the charging equipment for leaks as follows:
(a) Make sure that the charging valve (6) and the control valve (13) on the three-way valve (12) are closed.
(b) Slowly open the control valve (19) on the three-way valve (12).
(c) Slowly open the control valve of the nitrogen source. Add nitrogen until the pressure shown on the pressure gage is 19 bar (275.5716 psi).
(d) Close the control valve of the nitrogen source.
(e) Let the pressure become stable, continue after a minimum of five minutes. This will make sure that there are no leaks in the charging equipment.
(f) Close the control valve (19) on the three-way valve (12).
(5) Do a check of the NLG shock absorber charge pressure as follows:
(a) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure and record the temperature adjacent to the charging valve (6). Make sure that the thermometer touches the shock absorber outer-cylinder. If possible, measure the temperature at the top part of the cylinder (through the vent hole) at the aft part of the main fitting.
(b) Use the M21930 FILLING ASSEMBLY to open the charging valve (6). Open the control valve (19) and record the pressure shown on the pressure gage (10).
(c) Close the control valve (19) and the charging valve (6).
(d) Refer to the table and use the recorded temperature value to identify the correct charge pressure.
(e) If the recorded pressure value is the same as the correct pressure plus or minus 0.5 bar (7.2519 psi), go to step (7).
(6) If the pressure is incorrect, inflate the NLG shock absorber as follows:
(b) Use the M21930 FILLING ASSEMBLY to open the charging valve (6).
(c) Gradually open the control valve of the nitrogen source to adjust the charge pressure in the shock absorber. Do this until you get the correct value as identified in step (5)(d).
(d) Close the control valve (19) on the three-way valve (12).
(e) Use the M21930 FILLING ASSEMBLY to close the charging valve (6).
(f) Let the pressure become stable, continue after fifteen minutes.
(g) Open the control valve (19) on the three-way valve (12) and the charging valve (6). Make sure that the pressure gage (10) shows the same pressure as the correct pressure in step (5)(d) plus or minus 0.5 bar (7.2519 psi).
(h) If necessary, do steps (a) to (g) again to adjust the pressure.
(7) Remove the equipment as follows:
(a) Close the control valve (19) on the three-way valve (12).
(b) Use the M21930 FILLING ASSEMBLY to close the charging valve (6).
(c) Close the control valve of the nitrogen source.
(d) Open the control valve (13) to release the pressure. Remove the nitrogen source from the three-way valve (12). Close the control valve (13).
(f) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD from the charging valve (6).
(g) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in ).
(h) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (6).
(i) Install the blanking cap (7) on the charging valve (6).
Subtask 12-12-32-586-054-A (1) Make sure that the shock absorber is fully extended. Dimension H must be between 447 mm (17.5984 in.) and 451 mm (17.7559 in.).
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NOTE: Use an applicable RULER - STEEL to measure dimension H.
(2) Install the CHARGING EQUIPMENT - FLUID, STANDARD on the M21930 FILLING ASSEMBLY as follows: (a) Connect the nitrogen source hose (18) to the NITROGEN COMPRESSED SOURCE - GROUND.
(b) Connect the nitrogen source hose (18) to the three-way valve (12).
(c) Connect the filling hose (11) to the three-way valve (12).
NOTE: It is recommended to use a filling hose (11) of less than 3 m (9.84 ft.) long. A filling hose length of more than 3 m (9.84 ft.) will decrease pressure measurement accuracy.
(d) Remove the blanking cap (1) and the plug (5) from the M21930 FILLING ASSEMBLY. (e) Connect the filling hose (11) to the end fitting (2) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (13) and (19) on the three-way valve (12) and the control valve of the nitrogen source. Blow nitrogen through the charging equipment to bleed the system with nitrogen.
(g) Close the control valves (13) and (19) on the three-way valve (12) and the control valve of the nitrogen source.
CAUTION:
MAKE SURE THAT YOU USE A GAGE WITH THE SPECIFIED PRESSURE RANGE. THIS IS NECESSARY TO GET AN ACCURATE PRESSURE MEASUREMENT.
(h) Install the GAGE 0 TO 2000 PSI (0 TO 138 BAR) - PRESSURE (10) on the three-way valve (12). (3) Install the M21930 FILLING ASSEMBLY on the charging valve (6) as follows:
(a) Remove the blanking cap (7) from the charging valve (6).
(b) Move the wrench (9) up to the knurled shoulder (3) and install the M21930 FILLING ASSEMBLY on the charging valve (6).
(c) Turn the core (8) of the M21930 FILLING ASSEMBLY clockwise with the knurled shoulder (3). This will install the seal (4) on the charging valve (6).
(4) Do a check of the charging equipment for leaks as follows:
(a) Make sure that the charging valve (6) and the control valve (13) on the three-way valve (12) are closed.
(b) Slowly open the control valve (19) on the three-way valve (12).
(c) Slowly open the control valve of the nitrogen source. Add nitrogen until the pressure shown on the pressure gage is 19 bar (275.5716 psi).
(d) Close the control valve of the nitrogen source.
(e) Let the pressure become stable, continue after a minimum of five minutes. This will make sure that there are no leaks in the charging equipment.
(f) Close the control valve (19) on the three-way valve (12).
(5) Do a check of the NLG shock absorber charge pressure as follows:
(a) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure and record the temperature adjacent to the charging valve (6). Make sure that the thermometer touches the shock absorber outer-cylinder. If possible, measure the temperature at the top part of the cylinder (through the vent hole) at the aft part of the main fitting.
(b) Use the M21930 FILLING ASSEMBLY to open the charging valve (6). Open the control valve (19) and record the pressure shown on the pressure gage (10).
(c) Close the control valve (19) and the charging valve (6).
(d) Refer to the table and use the recorded temperature value to identify the correct charge pressure.
(e) If the recorded pressure value is the same as the correct pressure plus or minus 0.5 bar (7.2519 psi), go to step (7).
(6) If the pressure is incorrect, inflate the NLG shock absorber as follows:
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.
(a) Open the control valve (19) on the three-way valve (12). (b) Use the M21930 FILLING ASSEMBLY to open the charging valve (6).
(c) Gradually open the control valve of the nitrogen source to adjust the charge pressure in the shock absorber. Do this until you get the correct value as identified in step (5)(d).
(d) Close the control valve (19) on the three-way valve (12).
(e) Use the M21930 FILLING ASSEMBLY to close the charging valve (6).
(f) Let the pressure become stable, continue after fifteen minutes.
(g) Open the control valve (19) on the three-way valve (12) and the charging valve (6). Make sure that the pressure gage (10) shows the same pressure as the correct pressure in step (5)(d) plus or minus 0.5 bar (7.2519 psi).
(h) If necessary, do steps (a) to (g) again to adjust the pressure.
(7) Remove the equipment as follows:
(a) Close the control valve (19) on the three-way valve (12).
(b) Use the M21930 FILLING ASSEMBLY to close the charging valve (6).
(c) Close the control valve of the nitrogen source.
(d) Open the control valve (13) to release the pressure. Remove the nitrogen source from the three-way valve (12). Close the control valve (13).
NOTE: Do not remove the charging equipment if you do the aircraft-on-ground measurement after the aircraft-on-jacks measurement. If you do not remove the charging equipment, go to Para.4.C.
(e) Remove the pressure gage (10). (f) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD from the charging valve (6).
(g) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in )
. (h) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (6).
(i) Install the blanking cap (7) on the charging valve (6).
C. Lower the Aircraft
(1) Lower the aircraft onto its wheels (Ref. AMM TASK 07-11-00-586-002) or (Ref. AMM TASK 07-11-00-586-001).
Subtask 12-12-32-614-081-A (1) Lower the aircraft onto its wheels (Ref. AMM TASK 07-11-00-586-002) or (Ref. AMM TASK 07-11-00-586-001).
D. Check of the NLG Shock Absorber Charge-Pressure (Aircraft on Ground)
(a) Connect one end of the nitrogen source hose (18) to the nitrogen source.
(b) Connect the other end of the nitrogen source hose (18) to the three-way valve (12).
(c) Connect one end of the filling hose (11) to the three-way valve (12).
(e) Connect the other end of the filling hose (11) to the end fitting (2) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (13) and (19) on the three-way valve (12).
(g) Slowly open the control valve on the nitrogen source to bleed the system through the charging equipment.
(h) Close the control valves (13) and (19) on the three-way valve (12).
(i) Close the control valve on the nitrogen source.
(2) Install the M21930 FILLING ASSEMBLY on the charging valve (6) as follows:
(a) Remove the blanking cap (7) from the charging valve (6).
(b) Move the wrench (9) up to the knurled shoulder (3) and install the M21930 FILLING ASSEMBLY on the charging valve (6).
(c) Turn the core (8) of the M21930 FILLING ASSEMBLY clockwise with the knurled shoulder (3).
(a) Make sure that the charging valve (6) and the control valve (13) on the three-way valve (12) are closed.
(b) Open the control valve (19) on the three-way valve (12).
(c) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure the temperature of the NLG shock absorber adjacent to the charging valve (6).
(d) Make sure that the thermometer touches the NLG shock absorber outer-cylinder.
(f) Measure and record dimension H of the NLG shock-absorber extension.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
(g) Use the recorded dimension H and temperature values to identify the correct pressure for the NLG shock-absorber extension.
NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL
NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL
NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL
NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL
(h) Gradually open the control valve of the nitrogen source.
(i) Fill nitrogen until the pressure gage (10) shows the necessary pressure plus or minus 0.5 bar (7 psi).
(j) Close the control valve of the nitrogen source.
(k) Do a check of the pressure in the charging equipment.
(l) Wait for a minimum of five minutes to let the pressure become stable.
(4) Do a check of the NLG shock-absorber charge pressure as follows:
(a) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure the temperature of the NLG shock absorber adjacent to the charging valve(6).
(b) Make sure that the thermometer touches the NLG shock-absorber outer-cylinder.
(d) Use the M21930 FILLING ASSEMBLY to slowly open the charging valve (6).
(e) Open the control valve (19) on the three-way valve (12).
(f) Read and record the pressure shown on the pressure gage (10).
(g) Measure and record the shock absorber extension, dimension H.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
(h) Use the recorded pressure and temperature values to identify the correct dimension H for the shock absorber extension. Compare this value with the dimension H recorded in step (g).
NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL
NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL
NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL
NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL
(i) If the recorded H value is the same as the correct dimension H plus or minus 10 mm (0.39 in.), go to step (5).
(j) If the dimension H is incorrect, do the NLG shock-absorber oil replenishment and nitrogen filling procedure (Ref. AMM TASK 12-12-32-611-001).
(5) Remove the charging equipment as follows:
(a) Close the control valve (19) on the three-way valve (12).
(b) Use the M21930 FILLING ASSEMBLY to close the charging valve (6).
(c) Open the control valve (13) on the three-way valve (12) to release the pressure.
(d) Remove the nitrogen source from the three-way valve (12).
(e) Remove the pressure gage (10).
(f) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD from the charging valve (6).
(g) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in ).
(h) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (6).
(i) Install the blanking cap (7) on the charging valve (6).
5. Close-upNOTE: It is not necessary to do the procedure that follows (aircraft-on-ground check) immediately, if:
- The NLG shock-absorber charge pressure and extension is correct after the aircraft-on-jacks check. The aircraft can continue to fly for a maximum of eight days before you must do the aircraft-on-ground check.
NOTE: The aircraft must be stable and no persons must move in the aircraft during this procedure.
(1) Install the CHARGING EQUIPMENT - FLUID, STANDARD on the M21930 FILLING ASSEMBLY as follows: (a) Connect one end of the nitrogen source hose (18) to the nitrogen source.
(b) Connect the other end of the nitrogen source hose (18) to the three-way valve (12).
(c) Connect one end of the filling hose (11) to the three-way valve (12).
NOTE: The length of the filling hose (11) must not be more than 3 m (9.84 ft.). A filling hose length of more than 3 m (9.84 ft.) will decrease the precision of the pressure measurement.
(d) Remove the blanking cap (1) and the plug (5) from the M21930 FILLING ASSEMBLY. (e) Connect the other end of the filling hose (11) to the end fitting (2) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (13) and (19) on the three-way valve (12).
(g) Slowly open the control valve on the nitrogen source to bleed the system through the charging equipment.
(h) Close the control valves (13) and (19) on the three-way valve (12).
(i) Close the control valve on the nitrogen source.
CAUTION:
MAKE SURE THAT YOU USE A GAGE WITH THE SPECIFIED PRESSURE RANGE. THIS IS NECESSARY TO GET AN ACCURATE PRESSURE MEASUREMENT.
(j) Install the GAGE 200 BAR (2900 PSI) - PRESSURE (10) on the three-way valve (12). (2) Install the M21930 FILLING ASSEMBLY on the charging valve (6) as follows:
(a) Remove the blanking cap (7) from the charging valve (6).
(b) Move the wrench (9) up to the knurled shoulder (3) and install the M21930 FILLING ASSEMBLY on the charging valve (6).
(c) Turn the core (8) of the M21930 FILLING ASSEMBLY clockwise with the knurled shoulder (3).
NOTE: This will install the seal (4) on the charging valve (6).
(3) Do a check of the charging equipment for leaks as follows: (a) Make sure that the charging valve (6) and the control valve (13) on the three-way valve (12) are closed.
(b) Open the control valve (19) on the three-way valve (12).
(c) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure the temperature of the NLG shock absorber adjacent to the charging valve (6).
(d) Make sure that the thermometer touches the NLG shock absorber outer-cylinder.
NOTE: If possible, you must measure the temperature at the top part of the cylinder (through the vent hole) at the aft part of the main fitting.
(e) Record this temperature (f) Measure and record dimension H of the NLG shock-absorber extension.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL (i) Fill nitrogen until the pressure gage (10) shows the necessary pressure plus or minus 0.5 bar (7 psi).
(j) Close the control valve of the nitrogen source.
(k) Do a check of the pressure in the charging equipment.
(l) Wait for a minimum of five minutes to let the pressure become stable.
NOTE: This will make sure that there are no leaks in the charging equipment.
(m) Close the control valve (19) on the three-way valve (12). (4) Do a check of the NLG shock-absorber charge pressure as follows:
(a) Use a THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F) to measure the temperature of the NLG shock absorber adjacent to the charging valve(6).
(b) Make sure that the thermometer touches the NLG shock-absorber outer-cylinder.
NOTE: If possible, you must measure the temperature at the top part of the cylinder (through the vent hole) at the aft part of the main fitting.
(c) Record this temperature. (d) Use the M21930 FILLING ASSEMBLY to slowly open the charging valve (6).
(e) Open the control valve (19) on the three-way valve (12).
(f) Read and record the pressure shown on the pressure gage (10).
(g) Measure and record the shock absorber extension, dimension H.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Positive Temperatures ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL NLG Pressure/Extension Data (Weight on Wheels) - Negative Temperatures ** ON A/C NOT FOR ALL (j) If the dimension H is incorrect, do the NLG shock-absorber oil replenishment and nitrogen filling procedure (Ref. AMM TASK 12-12-32-611-001).
(5) Remove the charging equipment as follows:
(a) Close the control valve (19) on the three-way valve (12).
(b) Use the M21930 FILLING ASSEMBLY to close the charging valve (6).
(c) Open the control valve (13) on the three-way valve (12) to release the pressure.
(d) Remove the nitrogen source from the three-way valve (12).
(e) Remove the pressure gage (10).
(f) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD from the charging valve (6).
(g) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in )
. (h) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (6).
(i) Install the blanking cap (7) on the charging valve (6).
Subtask 12-12-32-410-054-A
A. Close Access
(1) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from the linkage of each forward NLG door (Ref. AMM TASK 32-22-00-410-001).
(2) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).
Subtask 12-12-32-942-072-A (1) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from the linkage of each forward NLG door (Ref. AMM TASK 32-22-00-410-001).
(2) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).
B. Removal of the Equipment
(1) Remove the safety barriers.
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(1) Remove the safety barriers.
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.