Removal of the Recirculation Filter Cartridge

TASK 21-21-41-000-001-A
Removal of the Recirculation Filter Cartridge

WARNING: MAKE SURE THAT AIR IS NOT SUPPLIED TO THE AIR CONDITIONING SYSTEM FROM THE MAIN ENGINE, THE APU OR A GROUND SOURCE. HOT COMPRESSED AIR CAN CAUSE INJURY TO PERSONNEL.

CAUTION: BE VERY CAREFUL WHEN YOU DO WORK ON OR NEAR THE AIR-CONDITIONING DUCTS. THE DUCTS ARE MADE OF THIN MATERIAL AND YOU CAN EASILY BREAK THEM.

NOTE: The procedure is the same for recirculation filter cartridges 4012HM and 4013HM.

ZONE: 130
FIN: 4012HM
FIN: 4013HM

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

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	1	GLOVES - LATEX OR NITRILE
No specific	1	GOGGLES - SAFETY
No specific	1	LIGHT SOURCE - TORCH
No specific	1	OVERALL WITH HOOD
No specific	AR	PLUG - BLANKING
No specific	1	RESPIRATOR - PARTICULATE (NIOSH CLASS N, EN149:2001)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
130	FWD CARGO COMPT AFT BULKHEAD OF AVNCS COMPT TO FWD PRESSURE BULKHEAD OF WING CENTER BOX
191CB, 191DB, 825

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 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-003-A	Open the FWD or Aft Cargo-Compartment Door with the Hand Pump
Recirculation Filter Cartridge

3. Job Set-up
Subtask 21-21-41-861-050-A

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

Subtask 21-21-41-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4012HM (RECIRC FILTER CARTRIDGE 1)
122VU	AIR COND/RECIRC FAN/L/CTL	2HG	X20
122VU	AIR COND/RECIRC FAN/L/SPLY	1HG	X18
FOR FIN: 4013HM (RECIRC FILTER CARTRIDGE 2)
122VU	AIR COND/RECIRC FAN/R/CTL	11HG	W20
122VU	AIR COND/RECIRC FAN/R/SPLY	3HG	W18

Subtask 21-21-41-941-050-A

C. Safety Precautions
(1) In the cockpit, on AIR COND panel 30VU:
(a) Make sure that the APU BLEED pushbutton switch is released (the OFF legend is on).
(b) Make sure that the ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are released (the OFF legends are on).
(c) Make sure that the PACK 1 and the PACK 2 pushbutton switches are released (the OFF legends are on).
(d) Make sure that the HOT AIR pushbutton switch is released (the OFF legend is on).
(e) Put the WARNING NOTICE(S) in position to tell persons not to operate these pushbutton switches.
(2) At access doors 191CB and 191DB:
(a) On the HP and the LP ground connectors, put the WARNING NOTICE(S) in position to tell persons not to supply the ground air.

Subtask 21-21-41-010-050-A

D. Get Access
(1) Open forward cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(2) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position below forward cargo-compartment door 825.
(3) Remove the access panel from partition FR 34 or FR 35.7 (Ref. AMM TASK 25-54-12-000-001).

4. Procedure
Subtask 21-21-41-020-052-A

A. Removal of the Recirculation Filter Cartridge

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.

(1) Use the equipment that follow:
(a) Plastic disposal bags (38 in. (0.9652 m) x 48 in. (1.2192 m), 40 USgal (151.4177 l) to 42 USgal (158.9886 l)).
(b) Personal protective equipment and clothing:

RESPIRATOR - PARTICULATE (NIOSH CLASS N, EN149:2001)
GOGGLES - SAFETY
GLOVES - LATEX OR NITRILE
OVERALL WITH HOOD
LIGHT SOURCE - TORCH.

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.

(2) Removal of the recirculation filter cartridge (3):
(a) For the recirculation filter housing (1), part number 34800B200-1:
1 Hold the recirculation filter cartridge (3) and turn the fastener (2) counterclockwise to the UNLOCKED position.
(b) For the recirculation filter housing (1), part number QB0658 series:
1 Hold the recirculation filter cartridge (3) and turn the lever (2) counterclockwise.
2 Pull the lever (2).
(c) Remove the recirculation filter cartridge (3) from the recirculation filter housing (1).

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.

(3) Put the recirculation filter cartridge (3) in a plastic disposal bag and discard it.
(4) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.03.31 23:00:50 UTC