Installation of the Filter Assembly

TASK 21-26-43-400-003-A
Installation of the Filter Assembly

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.

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

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
824

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-26-43-920-001-A	Discard Filter Cartridge (PALL)
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
Filter Assembly

3. Job Set-up
Subtask 21-26-43-860-052-A ** ON A/C NOT FOR ALL

A. Make sure that the ground service network is energized (Ref. AMM TASK 24-42-00-861-001).

Subtask 21-26-43-010-067-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position below the rear avionics compartment door (824).
(2) Make sure that the access door 824 is open.

Subtask 21-26-43-865-073-A ** ON A/C NOT FOR ALL

C. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

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
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AE02
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04

4. Procedure
Subtask 21-26-43-420-060-B ** ON A/C NOT FOR ALL

A. Installation of the Filter Assembly
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Remove the blanking plugs from the disconnected line ends.
(4) Install the filter body (3).
(5) Install the screws (1) and the nuts (2). Do not fully tighten at this time.
(6) Attach the bonding strap (12) to the filter body (3) with the screw (11), the washer (10) and the nut (9). Tighten the nut (9).
(7) Install the drain hose (6).
(8) Install the clamp (7) and tighten.
(9) Tighten the screws (1).
(10) Install the flexible sleeve (5).
(11) Install and tighten the clamps (4).

NOTE: Use the clamps (4) kept during the removal procedure.

(12) Make sure that the attachments (8) are correctly tightened.
(13) Release the two fastener devices, open the door and install the filter as mentioned in (Ref. AMM TASK 21-26-43-920-001).

5. Close-up
Subtask 21-26-43-410-063-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 21-26-43-865-074-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
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AE02
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04

Subtask 21-26-43-862-071-A ** ON A/C NOT FOR ALL

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

[Rev.10 from 2021] 2026.04.02 06:11:06 UTC