Draining and Flushing of Standby Pneumatic Circuits

TASK 34-22-25-170-001-A
Draining and Flushing of Standby Pneumatic Circuits

CAUTION: BEFORE YOU DO THE FLUSHING AND/OR DRAINING, MAKE SURE THAT:

YOU DISCONNECT THE QUICK-DISCONNECT COUPLINGS OF THE ADM'S
YOU REMOVE THE ISIS INDICATOR.

IF YOU DO NOT OBEY THESE INSTRUCTIONS, DAMAGE TO THESE COMPONENTS CAN OCCUR DURING THE FLUSHING AND/OR DRAINING.

ZONE: 120
FIN: 19FP3 ** ON A/C NOT FOR ALL
FIN: 19FP8 ** ON A/C NOT FOR ALL

1. Reason for the Job
Refer to the MPD TASK: 342200-02
DRAINING AND FLUSHING OF STANDBY PNEUMATIC CIRCUITS

To remove the water from the standby static pressure lines.
To remove dust and particles from the standby static and standby total pressure lines.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 1M(3 FT)
No specific	AR	NITROGEN COMPRESSED SOURCE 2 BAR (29 PSI) - DRY
No specific	AR	PLUG - BLANKING
No specific	AR	WIRE - NYLON
No specific	Torque wrench: range to between 4 and 3.6 m.N (35.40 and 31.86 lbf.in )
No specific	Torque wrench: range to between 13 and 12 m.N (115.04 and 106.19 lbf.in )
98D34003500000	2	ADAPTER COVER-STATIC PORT
98D34103002000	1	ADAPTERS - AIR DATA SYSTEM FLUSHING
98D34103004001	1	CLEANER-PITOT PROBE

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
120	AVIONICS COMPARTMENT
811

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
11	ORING	AIPC 52-73-01-02-030
11	ORING	AIPC 52-73-81-02-030

D. Referenced Information

REFERENCE	DESIGNATION
TASK 10-11-00-555-013-A	Installation of the Aircraft Protection Equipment
TASK 10-11-00-555-014-A	Removal of the Aircraft Protection Equipment
TASK 12-24-34-600-001-A	Bleeding of the Standby Air Data System
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 34-22-25-000-001-A	Removal of the Integrated Standby Instrument System (ISIS) Indicator
TASK 34-22-25-400-001-A	Installation of the Integrated Standby Instrument System (ISIS) Indicator
TASK 34-22-25-790-001-A	Low range Leak Test of the Standby Pneumatic circuits
Pressure Lines
Cabin-Pressure Detection Pressure-Switch 14WN - Static Line and Restrictor
Connection of the Quick-Disconnect Coupling

3. Job Set-up

NOTE: The hose couplings are self-sealing.

Subtask 34-22-25-861-051-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 34-22-25-010-051-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Put the ACCESS PLATFORM 1M(3 FT) in position in zone 110 at access door 811.
(2) Open access door 811.

Subtask 34-22-25-210-051-A ** ON A/C NOT FOR ALL

C. Inspection of the Quick-Disconnect Coupling

(1) Disconnect the quick-disconnect coupling from pitot probe 9DA3.
(2) Do a visual inspection of the quick-disconnect coupling and make sure that there is no unwanted material or blockage in it.
(3) Connect the quick-disconnect coupling again to pitot probe 9DA3.
(4) Make sure that you can see the blue ring on the quick-disconnect coupling.
(5) Pull the quick-disconnect coupling to make sure that it is correctly attached.
(6) Make sure that the quick-disconnect coupling is correctly engaged (the pin on the quick-disconnect male part is fully engaged into the groove in the quick-disconnect female part).

Subtask 34-22-25-020-052-B ** ON A/C NOT FOR ALL

D. Aircraft Maintenance Configuration
(1) If the aircraft protection equipment is installed, remove it (Ref. AMM TASK 10-11-00-555-014).
(2) Drain the standby air-data system (Ref. AMM TASK 12-24-34-600-001).
(3) Disconnect the quick-disconnect coupling (4) from the standby static pressure Air Data Module (ADM) 19FP8 and the quick-disconnect coupling (8) from the standby total pressure ADM 19FP3.
(4) Disconnection of the static line (13):

Cabin-Pressure Detection Pressure-Switch 14WN - Static Line and Restrictor ** ON A/C NOT FOR ALL

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE RESTRICTOR WHEN YOU DISCONNECT/CONNECT THE STATIC LINE. IF YOU DO NOT USE A SECOND WRENCH, YOU CAN CAUSE DAMAGE TO THE PRESSURE SWITCH AND/OR THE STATIC LINE.

(a) Disconnect the static line (13) from the restrictor (12).
(b) Remove the restrictor (12) and the O-ring (11) from the cabin-pressure detection pressure-switch 14WN (10).
(c) Remove the O-ring (11) from the restrictor (12) and discard the O-ring (11).
(d) Put the PLUG-BLANKING in each disconnected line end.
(5) Remove the water drain plug (2) from the water drain (1).
(6) In the cockpit, on left center instrument-panel 401VU:
(a) Remove the Integrated Standby Instrument System (ISIS) indicator 22FN (6) (Ref. AMM TASK 34-22-25-000-001).
(7) Connection of the hoses:
(a) Connect the 3-pin adapter (98D34103002100) of the 98D34103002000 ADAPTERS - AIR DATA SYSTEM FLUSHING to the hose (5) of the ISIS indicator (6).
(b) Connect the 2-pin adapter (98D34103002102) of the 98D34103002000 ADAPTERS - AIR DATA SYSTEM FLUSHING to the hose (7) of the ISIS indicator (6).
(c) Connect the hoses to the NITROGEN COMPRESSED SOURCE 2 BAR (29 PSI) - DRY.
(8) Attach the hoses to prevent movement.

4. Procedure
Subtask 34-22-25-170-050-B ** ON A/C NOT FOR ALL

A. Draining and Flushing of the Standby Static and the Standby Total Pressure Lines
(1) Blow the gas into the hoses (5) and into the hose (7), from one to the other, at a pressure of 2 bars (29 psi). Do this for approximately 5 minutes.
(2) Clean draining hole of the pitot probe 3 with 98D34103004001 CLEANER-PITOT PROBE and a WIRE - NYLON diameter 0.6 mm (0.023 inch) then 0.7 mm (0.027 inch).

NOTE: The WIRE-NYLON must have a length of 5 mm (0.1968 in.) to prevent contact between the metal tool element and the pitot probe.

(3) Make sure that there is no contamination in the pressurized gas at these outlets:

L static probe 3 and R static probe 3
Pitot probe 3
Water drain
Pipe of the cabin-pressure detection pressure-switch.

(4) Put the 98D34003500000 ADAPTER COVER-STATIC PORT on the L static probe 3 then on the R static probe 3.
(5) Make sure that the flow of gas is correct at :

The pipe of the pressure switch
The water drain.

(6) Stop the flow of gas.

Subtask 34-22-25-860-059-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to its initial configuration.

Pressure Lines ** ON A/C NOT FOR ALL

(1) Disconnect the NITROGEN COMPRESSED SOURCE 2 BAR (29 PSI) - DRY.
(2) Removal of the adapters:
(a) Disconnect the 2-pin adapter (98D34103002102) of the 98D34103002000 ADAPTERS - AIR DATA SYSTEM FLUSHING from the hose (7) of the ISIS indicator (6).
(b) Disconnect the 3-pin adapter (98D34103002100) of the 98D34103002000 ADAPTERS - AIR DATA SYSTEM FLUSHING from the hose (5) of the ISIS indicator (6).
(3) Install the water drain plug (2) on the water drain (1).
(4) Connection of the static line (13):

Cabin-Pressure Detection Pressure-Switch 14WN - Static Line and Restrictor ** ON A/C NOT FOR ALL

(a) Remove the PLUG-BLANKING from each disconnected line end.
(b) Install the new AIPC 52-73-01-02-030 ORING (11) or the new AIPC 52-73-81-02-030 ORING (11) on the restrictor (12).
(c) Install the restrictor (12) on cabin-pressure detection pressure-switch 14WN (10).
(d) TORQUE the restrictor (12) to between 4 and 3.6 m.N (35.40 and 31.86 lbf.in )

.
(e) Install the static line (13) on the restrictor (12).

(f) TORQUE the static line (13) to between 13 and 12 m.N (115.04 and 106.19 lbf.in )

.
(5) Connect the quick-disconnect coupling (8) to standby total-pressure ADM 19FP3 and the quick-disconnect coupling (4) to standby static-pressure ADM 19FP8.

Connection of the Quick-Disconnect Coupling ** ON A/C NOT FOR ALL

(6) Make sure that you can see the blue ring on the quick-disconnect couplings (4) and (8).
(7) Pull the quick-disconnect couplings (4) and (8) to make sure that they are correctly attached.
(8) In the cockpit, on left center instrument-panel 401VU:
(a) Install ISIS indicator 22FN (6) (Ref. AMM TASK 34-22-25-400-001).
(9) Disconnect the hoses.
(10) Tell a second approved mechanic to do a visual inspection of the quick-disconnect fitting connection only (the signatures of the two mechanics are mandatory).
(11) If you removed the aircraft protection equipment, install it (Ref. AMM TASK 10-11-00-555-013).

Subtask 34-22-25-790-051-A ** ON A/C NOT FOR ALL

C. Leak test
(1) Make sure that all the hoses are connected correctly.
(2) Do a leak test of the standby air data system
(Ref. AMM TASK 34-22-25-790-001).

5. Close-up
Subtask 34-22-25-410-051-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(3) Close the access door 811.
(4) Remove the access platform(s).

Subtask 34-22-25-862-050-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to its initial configuration.
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 00:59:58 UTC