Check the Demister Filter Element and the Filter Cartridge using Pressure Ports (LE BOZEC)

TASK 21-26-42-200-004-A
Check the Demister Filter Element and the Filter Cartridge using Pressure Ports (LE BOZEC)

ZONE: 120

1. Reason for the Job
Refer to the MPD TASK: 212643-11
CHECK DEMISTER FILTER ELEMENT AND FILTER CARTRIDGE USING PRESSURE PORTS (LE BOZEC)

NOTE: The effectivity of this task is "ALL". To know if this task is applicable to your aircraft, refer to the MPD task applicability. The information on weight variant groups is given in the MPD introductions.

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

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
97D21503000000	1	TEST TOOL-TWO SPEED FANS
EMA84	1	MANOMETER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
120	AVIONICS COMPARTMENT
824

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-26-43-600-018-A	Servicing of the Demister Filter
TASK 21-26-43-600-019-A	Servicing of the Filter Cartridge
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 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
TASK 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access
CMM 212600
Check for Blockage of the Demister Filter with the Pressure Ports ** ON A/C NOT FOR ALL
Check for Blockage of the Filter Cartridge with Pressure Ports ** ON A/C NOT FOR ALL
Test Tool Installation ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 21-26-42-010-058-B ** ON A/C NOT FOR ALL

A. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at access door 824.
(2) Open access door 824 (Ref. AMM TASK 52-41-00-010-002).

Subtask 21-26-42-861-056-B ** ON A/C NOT FOR ALL

B. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

NOTE: The energization of the aircraft electrical circuits starts the full test of the ventilation system. The test continues for 2 minutes approximately.
Do not connect the manometer until this test is completed.

Subtask 21-26-42-860-051-B ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) For the demister filter element:

Check for Blockage of the Demister Filter with the Pressure Ports ** ON A/C NOT FOR ALL

(a) Remove the protective caps from the pressure ports. The pressure ports of the demister filter are green.
(b) Connect the EMA84 MANOMETER to the pressure ports.
(2) For the filter cartridge:

Check for Blockage of the Filter Cartridge with Pressure Ports ** ON A/C NOT FOR ALL

(a) Remove the protective caps from the pressure ports. The pressure ports of filter cartridge are black.
(b) Connect the EMA84 MANOMETER to the pressure ports.

Subtask 21-26-42-480-050-D ** ON A/C NOT FOR ALL

D. Installation of the Test Tool

Test Tool Installation ** ON A/C NOT FOR ALL

(1) Disconnect the aircraft electrical connector (1) from the duct temperature sensor (2).
(2) Connect the connector (3) of the 97D21503000000 TEST TOOL-TWO SPEED FANS (4) to the duct temperature sensor (2).
(3) Connect the aircraft electrical connector (1) to the 97D21503000000 TEST TOOL-TWO SPEED FANS (4).
(4) On the 97D21503000000 TEST TOOL-TWO SPEED FANS (4), set the switch to the HIGH SPEED position.

4. Procedure
Subtask 21-26-42-210-060-A ** ON A/C NOT FOR ALL

A. Check for Blockage
(1) For the demister filter element:
(a) If the differential pressure is more than 12.5 mbar (0.18 psi):
1 Clean the filter CMM 212600 or replace it by a new one (Ref. AMM TASK 21-26-43-600-010).
(2) For the filter cartridge:
(a) If the differential pressure is more than 16.5 mbar (0.24 psi):
1 Clean the filter CMM 212600 or replace it by a new one (Ref. AMM TASK 21-26-43-600-011).

5. Close-up
Subtask 21-26-42-862-056-B ** ON A/C NOT FOR ALL

A. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

Subtask 21-26-42-080-051-D ** ON A/C NOT FOR ALL

B. Removal of the Test Tool

Test Tool Installation ** ON A/C NOT FOR ALL

(1) Disconnect the aircraft electrical connector (1) from the 97D21503000000 TEST TOOL-TWO SPEED FANS (4).
(2) Disconnect the connector (3) of the 97D21503000000 TEST TOOL-TWO SPEED FANS (4) from the duct temperature sensor (2).
(3) Connect the aircraft electrical connector (1) to the duct temperature sensor (2).

Subtask 21-26-42-860-052-B ** ON A/C NOT FOR ALL

C. Put the aircraft back to its initial configuration.
(1) Disconnect the EMA84 MANOMETER from the pressure ports.
(2) Install the protective caps on the pressure ports.

Subtask 21-26-42-410-057-B ** ON A/C NOT FOR ALL

D. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access door 824 (Ref. AMM TASK 52-41-00-410-002).
(3) Remove the access platform(s).

[Rev.8 from Aug 2017] 2026.04.02 06:11:06 UTC