Servicing of the Demister Filter

TASK 21-26-43-600-018-A
Servicing of the Demister Filter

WARNING: PUT ON GLOVES, A COVERALL WITH A HOOD, GOGGLES AND A PARTICULATE RESPIRATOR BEFORE YOU TOUCH THE FILTER. THE FILTER REMOVES SMALL PARTICLES (SMOKE, DUST, LINT, FIBERS, POLLEN) AND INFECTIOUS MATERIALS (BACTERIA, VIRUSES, MOLD SPORES, FUNGI) FROM THE AIR. THESE MATERIALS CAN CAUSE ILLNESS.

WARNING: DO NOT LET THE FILTER TOUCH YOUR SKIN. DO NOT SHAKE OR HIT THE FILTER. DO NOT LET THE FILTER FALL. DO NOT USE COMPRESSED AIR TO CLEAN THE FILTER OR FILTER HOUSING. THIS CAN CAUSE THE INFECTIOUS MATERIAL TO BECOME AIRBORNE. DISCARD THE FILTER IN A PLASTIC DISPOSAL BAG. IF YOU DO NOT OBEY THESE INSTRUCTIONS, INFECTIOUS MATERIAL FROM THE FILTER CAN CAUSE ILLNESS.

WARNING: PUT ALL AIR FILTERS THAT YOU REMOVE FROM THE AIRCRAFT INTO PLASTIC DISPOSAL BAGS. AIR FILTERS CAN CONTAIN INFECTIOUS MATERIALS WHICH CAN CAUSE ILLNESS. OBEY AIRLINE POLICY AND LOCAL HEALTH DEPARTMENT AND LAW ENFORCEMENT REGULATIONS FOR DISPOSAL OF INFECTIOUS MATERIALS.

CAUTION: USE ONLY THE GROUND SERVICE NETWORK TO SUPPLY ELECTRICITY BECAUSE THE AVIONICS VENTILATION SYSTEM IS NOT SERVICEABLE. IF YOU ENERGIZE THE AIRCRAFT ELECTRICAL CIRCUITS WITHOUT THE VENTILATION SYSTEM YOU WILL CAUSE DAMAGE TO ELECTRICAL EQUIPMENT.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
824

C. Referenced Information

REFERENCE	DESIGNATION
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 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access
Demister Air Filter ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 21-26-43-862-109-A ** ON A/C NOT FOR ALL

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

Subtask 21-26-43-861-114-A ** ON A/C NOT FOR ALL

B. Energize the ground service network (Ref. AMM TASK 24-42-00-861-001).

Subtask 21-26-43-865-117-A ** ON A/C NOT FOR ALL

C. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10

Subtask 21-26-43-010-093-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at the access door 824.
(2) Open the access door 824.

4. Procedure
Subtask 21-26-43-020-080-A ** ON A/C NOT FOR ALL

A. Removal of the Demister Filter
(1) Move the locking handle of the cover (3) to the top to release the handle.
(2) Pull the handle to remove the filter/cover assembly.

NOTE: Make sure that the plate (2) is in the correct position.

(3) Disengage the tabs one by one from the top to the bottom to remove the filter element (1) from the cover (3).

Subtask 21-26-43-615-067-A ** ON A/C NOT FOR ALL

B. Remove the demister filter and replace it by a new or restored one.

Subtask 21-26-43-160-072-A ** ON A/C NOT FOR ALL

C. Clean the component interfaces and the adjacent area.

Subtask 21-26-43-210-080-A ** ON A/C NOT FOR ALL

D. Do an inspection of the component interfaces and the adjacent area.

NOTE: Make sure that the plate (2) is in the correct position.

Subtask 21-26-43-420-081-A ** ON A/C NOT FOR ALL

E. Installation of the Demister Filter
(1) Engage the tabs of the cover (3) into the recesses of the filter element (1). Apply pressure to assemble the two components.
(2) Engage the filter element (1) in the body.
(3) Lock the handle of the cover (3) into the body.

5. Close-up
Subtask 21-26-43-410-088-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) Close the access door 824 (Ref. AMM TASK 52-41-00-410-002).
(3) Remove the access platform(s).

Subtask 21-26-43-865-118-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10

Subtask 21-26-43-861-115-A ** ON A/C NOT FOR ALL

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

Subtask 21-26-43-862-110-A ** ON A/C NOT FOR ALL

D. De-energize the ground service network (Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.03.31 23:03:13 UTC