DOC AIRBUS | AMM A320FFunctional Check of NLG Shock Absorber Charge Pressure and Fluid Level
TASK 12-12-32-610-002-A
Functional Check of NLG Shock Absorber Charge Pressure and Fluid Level
Refer to the MPD TASK: 322113-01
FUNCTIONAL CHECK OF NLG SHOCK ABSORBER CHARGE PRESSURE AND FLUID LEVEL.
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 12-12-32-941-075-A
Subtask 12-12-32-614-084-A
Subtask 12-12-32-410-056-A
[Rev.10 from 2021]
2026.03.31 22:54:54 UTC
Functional Check of NLG Shock Absorber Charge Pressure and Fluid Level
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 JobRefer to the MPD TASK: 322113-01
FUNCTIONAL CHECK OF NLG SHOCK ABSORBER CHARGE PRESSURE AND FLUID LEVEL.
NOTE: The NLG shock absorber charge pressure and fluid level must be measured with the aircraft in heavy configuration and in light configuration. This procedure does the heavy configuration check first and then the light configuration check. If necessary, the light configuration check can be done first followed by the heavy configuration check, refer to Task 12-12-32-610-002-A01.
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 charge pressure and fluid level, you can do Task 12-12-32-610-001-A or Task 12-12-32-610-001-A01. If you do Task 12-12-32-610-001-A or Task 12-12-32-610-001-A01, you must jack the aircraft.
NOTE: For the tasks completed with the aircraft in a weight-on-wheels configuration, the aircraft must be stable (no movement of persons in the aircraft).
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 200 BAR (2900 PSI) - PRESSURE |
| No specific | AR | NITROGEN COMPRESSED SOURCE - GROUND |
| No specific | 1 | RULER - GRADUATED |
| No specific | AR | SAFETY BARRIER(S) |
| No specific | 1 | 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 12-12-32-611-001-A | NLG Shock Absorber Oil Replenishment and Nitrogen Filling (Aircraft on Wheels) |
| TASK 32-00-00-081-002-A | Removal of the Safety Devices from the Landing Gear Doors |
| 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 12-12-32-941-075-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 12-12-32-010-056-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 below 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 below the NLG.
Subtask 12-12-32-614-084-A
A. Functional Check of the NLG Shock Absorber Charge-Pressure and Fluid Level in Heavy Aircraft Configuration
(2) Read the values H1 and H2 for the aircraft in the related figure for the recorded temperature.
Limit of the H Dimension ** ON A/C NOT FOR ALL
Limit of the H Dimension ** ON A/C NOT FOR ALL
Limit of the H Dimension ** ON A/C NOT FOR ALL
Limit of the H Dimension ** ON A/C NOT FOR ALL
(a) Connect the nitrogen source hose (16) to the NITROGEN COMPRESSED SOURCE - GROUND.
(b) Connect the nitrogen source hose (16) to the three-way valve (13).
(c) Connect the filling hose (12) to the three-way valve (13).
(e) Connect the filling hose (12) to the end fitting (1) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (14) and (15) on the three-way valve (13) and the control valve on the nitrogen source. Blow nitrogen through the charging equipment to bleed the system.
(g) Close the control valve on the nitrogen source.
(h) Close the control valves (14) and (15) on the three-way valve (13).
(5) 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).
(6) Do a check of the CHARGING EQUIPMENT - FLUID, STANDARD for leaks as follows:
(a) Make sure that the charging valve (6) and the control valve (14) on the three-way valve (13) are closed.
(b) Slowly open the control valve (15) on the three-way valve (13).
(c) Use a CONTACT DIGITAL THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F), to measure and record the temperature of the NLG shock absorber adjacent to the charging valve (6). Make sure that the thermometer touches the shock absorber outer-cylinder.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
(e) Use the recorded dimension H and the temperature values to identify the correct pressure for the 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
(f) Slowly open the control valve of the nitrogen source. Add nitrogen until the pressure read on the pressure gage is the same as the correct pressure plus or minus 0.5 bar (7.2519 psi).
(g) Close the control valve of the nitrogen source.
(h) After the pressure has been adjusted, wait for a minimum of 5 minutes to make sure that the pressure is stable. This will make sure that there are no leaks in the charging equipment.
(i) Close control valve (15) on the three-way valve (13).
(7) Do a check of the NLG shock absorber charge pressure as follows:
(a) Use a CONTACT DIGITAL THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F), to measure and record the temperature of the NLG shock absorber adjacent to the charging valve (6). Make sure that the thermometer touches the shock absorber outer-cylinder.
(c) Slowly open the control valve (15) on the three-way valve (13). Read and record the pressure shown on the pressure gage (11).
(d) 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
(e) Use the pressure and temperature value tables to identify the correct dimension H for the shock absorber extension. Compare this value with the dimension H you recorded in step (7)(d).
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
(f) If the value of dimension H you recorded is the same as the correct dimension H value plus or minus 10 mm (0.3937 in.) , do step (9).
(g) If the difference between the value of dimension H you recorded and the correct dimension H value is more than 10 mm (0.3937 in.), do step (8).
(8) Inflate the NLG shock absorber as follows:
(b) Continue to inflate the shock absorber until the shock absorber extends by 30 mm (1.1811 in.) more.
(c) When the pressure has become stable, record the pressure shown on the pressure gage (11).
(d) Slowly open the control valve (14) on the three-way valve (13). Deflate the shock absorber until the dimension H is correct as recorded in step (7)(e).
(f) Wait for a minimum of 10 minutes to let the pressure become stable in the shock absorber.
(g) Open the control valve (15) and measure and record the pressure on the pressure gage (11).
(h) Check that the dimension H compares with the correct dimension H plus or minus 10 mm (0.3937 in.) as recorded in step (7)(e).
(i) If necessary, do steps (8)(a) thru (h) again to adjust dimension H.
(9) When the dimension H is correct, close the control valve (15) on the three-way valve (13).
(10) Close the charging valve (6) with the FILLING ASSEMBLY.
(11) Close the control valve of the nitrogen source.
(12) Slowly open the control valve (14) to release the pressure in the charging system.
(13) Make sure that the measured dimension H is between the values H1 and H2.
(14) If the recorded dimension H is not between the values H1 and H2, the aircraft is not in a correct configuration. Put the aircraft in a heavy configuration to get dimension H between H1 and H2, related to the type of the aircraft.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL
(16) Remove the pressure gage (11).
(17) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD.
(18) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in ).
(20) Install the blanking cap (7) on the charging valve (6).
Subtask 12-12-32-614-086-A NOTE: You must use a STEEL - RULER - GRADUATED 1 mm (0.0394 in.) to measure and record the shock absorber extension, dimension H.
(1) Use a CONTACT DIGITAL THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F), ACCURACY plus or minus 2 DEG.C (35.60 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. (2) Read the values H1 and H2 for the aircraft in the related figure for the recorded temperature.
Limit of the H Dimension ** ON A/C NOT FOR ALL Limit of the H Dimension ** ON A/C NOT FOR ALL Limit of the H Dimension ** ON A/C NOT FOR ALL Limit of the H Dimension ** ON A/C NOT FOR ALL CAUTION:
MAKE SURE THAT THE AIRCRAFT WEIGHT AND BALANCE STAY IN THE SPECIFIED LIMITS WHILE YOU SELECT A CORRECT CONFIGURATION.
(3) Put the aircraft in a heavy configuration to get dimension H between H1 and H2. NOTE: To get the necessary Center of Gravity (CG) and weight configuration for this task refer to the TSM Task 32-31-00-810-876. This Task gives the 'H' values for each aircraft weight and CG. The aircraft must be in the heavy configuration as follows:
(4) Install the CHARGING EQUIPMENT - FLUID, STANDARD on the M21930 FILLING ASSEMBLY as follows: - operational Empty Weight (OEW), aircraft full of fuel and with no load.
(a) Connect the nitrogen source hose (16) to the NITROGEN COMPRESSED SOURCE - GROUND.
(b) Connect the nitrogen source hose (16) to the three-way valve (13).
(c) Connect the filling hose (12) to the three-way valve (13).
NOTE: The filling hose (12) length must not be more than 3 m (9.84 ft.).
(d) Remove the plug (5) from the M21930 FILLING ASSEMBLY. (e) Connect the filling hose (12) to the end fitting (1) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (14) and (15) on the three-way valve (13) and the control valve on the nitrogen source. Blow nitrogen through the charging equipment to bleed the system.
(g) Close the control valve on the nitrogen source.
(h) Close the control valves (14) and (15) on the three-way valve (13).
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.
(i) Install the GAGE 200 BAR (2900 PSI) - PRESSURE ACCURACY 0.5 bar (7.2519 psi) (11) on the three-way valve (13). (5) 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).
(6) Do a check of the CHARGING EQUIPMENT - FLUID, STANDARD for leaks as follows:
(a) Make sure that the charging valve (6) and the control valve (14) on the three-way valve (13) are closed.
(b) Slowly open the control valve (15) on the three-way valve (13).
(c) Use a CONTACT DIGITAL THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F), to measure and record the temperature of the NLG shock absorber adjacent to the charging valve (6). Make sure that the thermometer touches the shock absorber outer-cylinder.
NOTE: If possible, measure the temperature at the top part of the cylinder (through the vent hole) at the aft part of the main fitting.
(d) 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 (g) Close the control valve of the nitrogen source.
(h) After the pressure has been adjusted, wait for a minimum of 5 minutes to make sure that the pressure is stable. This will make sure that there are no leaks in the charging equipment.
(i) Close control valve (15) on the three-way valve (13).
(7) Do a check of the NLG shock absorber charge pressure as follows:
(a) Use a CONTACT DIGITAL THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F), to measure and record the temperature of the NLG shock absorber adjacent to the charging valve (6). Make sure that the thermometer touches the shock absorber outer-cylinder.
NOTE: 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) Slowly open the charging valve (6) with the M21930 FILLING ASSEMBLY. (c) Slowly open the control valve (15) on the three-way valve (13). Read and record the pressure shown on the pressure gage (11).
(d) 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 (g) If the difference between the value of dimension H you recorded and the correct dimension H value is more than 10 mm (0.3937 in.), do step (8).
(8) 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) Slowly open the control valve of the nitrogen source. Inflate the shock absorber with nitrogen until the dimension H is correct as recorded in step (7)(e). (b) Continue to inflate the shock absorber until the shock absorber extends by 30 mm (1.1811 in.) more.
(c) When the pressure has become stable, record the pressure shown on the pressure gage (11).
(d) Slowly open the control valve (14) on the three-way valve (13). Deflate the shock absorber until the dimension H is correct as recorded in step (7)(e).
NOTE: Steps (b) thru (d) are to decrease the effect of the friction in the shock absorber on the measured value of the dimension H.
(e) Close the control valve (15) on the three-way valve (13). (f) Wait for a minimum of 10 minutes to let the pressure become stable in the shock absorber.
(g) Open the control valve (15) and measure and record the pressure on the pressure gage (11).
(h) Check that the dimension H compares with the correct dimension H plus or minus 10 mm (0.3937 in.) as recorded in step (7)(e).
(i) If necessary, do steps (8)(a) thru (h) again to adjust dimension H.
(9) When the dimension H is correct, close the control valve (15) on the three-way valve (13).
(10) Close the charging valve (6) with the FILLING ASSEMBLY.
(11) Close the control valve of the nitrogen source.
(12) Slowly open the control valve (14) to release the pressure in the charging system.
(13) Make sure that the measured dimension H is between the values H1 and H2.
(14) If the recorded dimension H is not between the values H1 and H2, the aircraft is not in a correct configuration. Put the aircraft in a heavy configuration to get dimension H between H1 and H2, related to the type of the aircraft.
NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NLG Shock Absorber - Dimension H ** ON A/C NOT FOR ALL NOTE: You must not remove the charging equipment and the filling assembly if you do the light aircraft configuration measurement after the heavy aircraft configuration measurement. If you do not remove the charging equipment and the filling assembly go to Para.4.B.(7).
(15) Remove the nitrogen source hose (16) from the nitrogen source. (16) Remove the pressure gage (11).
(17) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD.
(18) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in )
. WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
(19) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (6). (20) Install the blanking cap (7) on the charging valve (6).
B. Functional Check of the NLG Shock Absorber Charge-Pressure and Fluid Level in Light Aircraft Configuration
(2) Make sure that the thermometer touches the shock absorber outer-cylinder.
(4) Read the values H3 and H4 in the figure for the aircraft for the related recorded temperature.
Limit of the H Dimension ** ON A/C NOT FOR ALL
Limit of the H Dimension ** ON A/C NOT FOR ALL
Limit of the H Dimension ** ON A/C NOT FOR ALL
Limit of the H Dimension ** ON A/C NOT FOR ALL
(a) Connect one end of the the nitrogen source hose (16) to the NITROGEN COMPRESSED SOURCE - GROUND.
(b) Connect the other end of the nitrogen source hose (16) to the three-way valve (13).
(c) Connect one end of the filling hose (12) to the three-way valve (13).
(e) Connect the other end of the filling hose (12) to the end fitting (1) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (14) and (15) on the three-way valve (13).
(g) Slowly open the control valve on the nitrogen source to bleed the system through the charging equipment.
(h) Close the control valve on the nitrogen source.
(i) Close the control valves (14) and (15) on the three-way valve (13).
(7) 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 (14) on the three-way valve (13) are closed.
(b) Slowly open the control valve (15) on the three-way valve (13).
(c) Use a CONTACT DIGITAL 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 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
(g) Use the recorded dimension H and the 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) Slowly open the control valve of the nitrogen source.
(i) Fill nitrogen until the pressure read on the pressure gage (11) is the same as the correct pressure plus or minus 0.5 bar (7 psi).
(j) Close the control valve of the nitrogen source.
(k) Wait for a minimum of five minutes to let the pressure become stable.
(9) Do a check of the NLG shock-absorber charge pressure as follows:
(a) Use a CONTACT DIGITAL 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) Slowly open the charging valve (6) with the M21930 FILLING ASSEMBLY.
(e) Slowly open the control valve (15) on the three-way valve (13).
(f) Read and record the pressure shown on the pressure gage (11).
(g) Measure and record the 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
(h) Use the pressure and temperature value tables to identify the correct dimension H for the NLG shock-absorber extension. Compare this value with the dimension H you recorded in step (9)(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 value of dimension H you recorded is the same as the correct dimension H value plus or minus 10 mm (0.39 in.), do step (10).
(j) If the difference between the value of dimension H you recorded and the correct dimension H value is more than 10 mm (0.39 in.):
(a) Close the control valve (15) on the three-way valve (13).
(b) Close the charging valve (6) with the M21930 FILLING ASSEMBLY.
(c) Close the control valve of the nitrogen source.
(d) Slowly open the control valve (14) to release the pressure.
(e) Remove the nitrogen source from the three-way valve (13).
(f) Remove the pressure gage (11).
(g) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD from the charging valve (6).
(11) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in ).
(13) Install the blanking cap (7) on the charging valve (6).
5. Close-upNOTE: It is not necessary to do the procedure (light-aircraft configuration check) immediately, if:
- The NLG shock-absorber charge pressure and extension is correct after the heavy-aircraft configuration check. The aircraft can continue to fly for a maximum of eight days before you must do the light-aircraft configuration check.
NOTE: You must use a STEEL - RULER - GRADUATED - 1 mm (0.04 in.) to measure and record the dimension H of the NLG shock-absorber extension.
(1) Use a CONTACT DIGITAL THERMOMETER -45 TO 70 DEG.C (-49 TO 158 DEG.F), precision of plus or minus 2 DEG.C (35.60 DEG.F) to measure the temperature of the NLG shock absorber adjacent to the charging valve (6). (2) Make sure that the thermometer touches the 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.
(3) Record this temperature. (4) Read the values H3 and H4 in the figure for the aircraft for the related recorded temperature.
Limit of the H Dimension ** ON A/C NOT FOR ALL Limit of the H Dimension ** ON A/C NOT FOR ALL Limit of the H Dimension ** ON A/C NOT FOR ALL Limit of the H Dimension ** ON A/C NOT FOR ALL CAUTION:
MAKE SURE THAT THE AIRCRAFT WEIGHT AND BALANCE STAY IN THE SPECIFIED LIMITS WHILE YOU SELECT A CORRECT CONFIGURATION.
(5) Put the aircraft in a light configuration to get dimension H between H3 and H4. NOTE: To get the necessary Center of Gravity (CG) and weight configuration for this task refer to the TSM Task 32-31-00-810-876. This tasks gives the 'H' values for each aircraft weight and CG. The aircraft is near to its lightest empty weight:
(6) Install the CHARGING EQUIPMENT - FLUID, STANDARD on the M21930 FILLING ASSEMBLY as follows: - Aircraft defueled and with no load.
(a) Connect one end of the the nitrogen source hose (16) to the NITROGEN COMPRESSED SOURCE - GROUND.
(b) Connect the other end of the nitrogen source hose (16) to the three-way valve (13).
(c) Connect one end of the filling hose (12) to the three-way valve (13).
NOTE: The filling hose (12) length must not be more than 3 m (9.84 ft.).
(d) Remove the plug (5) from the M21930 FILLING ASSEMBLY. (e) Connect the other end of the filling hose (12) to the end fitting (1) of the M21930 FILLING ASSEMBLY.
(f) Slowly open the control valves (14) and (15) on the three-way valve (13).
(g) Slowly open the control valve on the nitrogen source to bleed the system through the charging equipment.
(h) Close the control valve on the nitrogen source.
(i) Close the control valves (14) and (15) on the three-way valve (13).
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 precision of 0.5 bar (7 psi) (11) on the three-way valve (13). (7) 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).
(8) Do a check of the CHARGING EQUIPMENT - FLUID, STANDARD for leaks as follows: (a) Make sure that the charging valve (6) and the control valve (14) on the three-way valve (13) are closed.
(b) Slowly open the control valve (15) on the three-way valve (13).
(c) Use a CONTACT DIGITAL 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 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 (i) Fill nitrogen until the pressure read on the pressure gage (11) is the same as the correct pressure plus or minus 0.5 bar (7 psi).
(j) Close the control valve of the nitrogen source.
(k) 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.
(l) Close control valve (15) on the three-way valve (13). (9) Do a check of the NLG shock-absorber charge pressure as follows:
(a) Use a CONTACT DIGITAL 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) Slowly open the charging valve (6) with the M21930 FILLING ASSEMBLY.
(e) Slowly open the control valve (15) on the three-way valve (13).
(f) Read and record the pressure shown on the pressure gage (11).
(g) Measure and record the 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 (j) If the difference between the value of dimension H you recorded and the correct dimension H value is more than 10 mm (0.39 in.):
- Do the NLG shock-absorber oil replenishment and nitrogen filling procedure (Ref. AMM TASK 12-12-32-611-001).
(a) Close the control valve (15) on the three-way valve (13).
(b) Close the charging valve (6) with the M21930 FILLING ASSEMBLY.
(c) Close the control valve of the nitrogen source.
(d) Slowly open the control valve (14) to release the pressure.
(e) Remove the nitrogen source from the three-way valve (13).
(f) Remove the pressure gage (11).
(g) Remove the M21930 FILLING ASSEMBLY and the CHARGING EQUIPMENT - FLUID, STANDARD from the charging valve (6).
(11) TORQUE the charging valve (6) to between 0.8 and 0.5 m.daN (70.80 and 44.25 lbf.in )
. WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
(12) Use Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) to do a leak check of the charging valve (6). (13) Install the blanking cap (7) on the charging valve (6).
Subtask 12-12-32-410-056-A
A. Close Access
(1) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from the linkage of each forward NLG door (Ref. AMM TASK 32-00-00-081-002).
(2) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).
Subtask 12-12-32-942-074-A (1) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from the linkage of each forward NLG door (Ref. AMM TASK 32-00-00-081-002).
(2) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).
B. Removal of the Equipment.
(1) Remove the SAFETY BARRIER(S).
(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 BARRIER(S).
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.