Removal of the Lower Part of the Mixer Unit
TASK 21-21-43-000-002-A
Removal of the Lower Part of the Mixer Unit
Do this task to get access to the Pressure Bulkhead at FR35 FWD Face as requested by MPD task 533152-01.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 21-21-43-860-053-A Subtask 21-21-43-865-053-A
Subtask 21-21-43-020-051-A
[Rev.10 from 2021]
2026.04.02 07:25:03 UTC
Removal of the Lower Part of the Mixer Unit
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.
WARNING:
MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.
WARNING:
DO NOT TOUCH THE COMPONENT UNTIL IT IS SUFFICIENTLY
COOL TO PREVENT BURNS.
CAUTION:
DO NOT PUT YOUR WEIGHT ON THE DUCTS. IT IS VERY EASY TO BREAK THEM.
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.
ZONE: 130
1. Reason for the JobDo this task to get access to the Pressure Bulkhead at FR35 FWD Face as requested by MPD task 533152-01.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 2M (6 FT) |
| No specific | AR | CAP - BLANKING |
| No specific | AR | PLUG - BLANKING |
| No specific | AR | SAFETY CLIP - CIRCUIT BREAKER |
| No specific | AR | WARNING NOTICE(S) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 130 | FWD CARGO COMPT AFT BULKHEAD OF AVNCS COMPT TO FWD PRESSURE BULKHEAD OF WING CENTER BOX |
| 825 |
| 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 06-41-53-00 | FUSELAGE-DESCRIPTION AND OPERATION |
Subtask 21-21-43-860-053-A Subtask 21-21-43-865-053-A
B. Open, safety and tag this(these) circuit breaker(s):
Subtask 21-21-43-941-052-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC | 52HH | D08 |
| ** ON A/C NOT FOR ALL | |||
| 122VU | AIR COND/FLOW/MIXER/FLAP | 3HB | V22 |
| 122VU | AIR COND/ZONE TEMP CTL/28VDC/SYS2 | 4HK | V20 |
| 122VU | AIR COND/ZONE TEMP CTL/28VDC/SYS1 | 3HK | V19 |
| 122VU | AIR COND/ZONE TEMP CTL/115VAC/SYS2 | 2HK | V18 |
| 122VU | AIR COND/ZONE TEMP CTL/115VAC/SYS1 | 1HK | V17 |
| ** ON A/C ALL | |||
| 122VU | AIR COND/RECIRC FAN/R/CTL | 11HG | W20 |
| 122VU | AIR COND/RECIRC FAN/R/SPLY | 3HG | W18 |
| 122VU | AIR COND/RECIRC FAN/L/CTL | 2HG | X20 |
| 122VU | AIR COND/RECIRC FAN/L/SPLY | 1HG | X18 |
| ** ON A/C NOT FOR ALL | |||
| 122VU | AIR COND/TEMP CTL SYS 2/CHAN A/115VAC | 53HH | W22 |
| 122VU | AIR COND/TEMP CTL SYS 2/CHAN A/28VDC | 55HH | W21 |
| 122VU | AIR COND/TEMP CTL SYS 1/CHAN A/115VAC | 49HH | X22 |
| 122VU | AIR COND/TEMP CTL SYS 1/CHAN A/28VDC | 51HH | X21 |
| 122VU | AIR COND/TEMP CTL SYS 2/CHAN B/28VDC | 56HH | Y21 |
| 122VU | AIR COND/TEMP CTL SYS 2/CHAN B/115VAC | 54HH | Y20 |
| 122VU | AIR COND/TEMP CTL SYS 1/CHAN B/115VAC | 50HH | Y18 |
C. Safety Precautions
(1) On the overhead panel, on panel 30VU:
(a) Make sure that the APU BLEED pushbutton switch is in the off position (the ON legend is off).
(b) Make sure that the ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are in the off position (the OFF legends are on).
(c) Make sure that the PACK 1 and the PACK 2 pushbutton switches are in the off position (the OFF legends are on).
(d) Make sure that the HOT AIR pushbutton switch is in the off position (the OFF legend is on).
(e) Put a WARNING NOTICE(S) in position to tell persons not to operate these pushbutton switches.
(2) On the HP and the LP ground connectors:
(a) Put the WARNING NOTICE(S) in position to tell persons not to supply the ground air.
Subtask 21-21-43-010-051-A (1) On the overhead panel, on panel 30VU:
(a) Make sure that the APU BLEED pushbutton switch is in the off position (the ON legend is off).
(b) Make sure that the ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are in the off position (the OFF legends are on).
(c) Make sure that the PACK 1 and the PACK 2 pushbutton switches are in the off position (the OFF legends are on).
(d) Make sure that the HOT AIR pushbutton switch is in the off position (the OFF legend is on).
(e) Put a WARNING NOTICE(S) in position to tell persons not to operate these pushbutton switches.
(2) On the HP and the LP ground connectors:
(a) Put the WARNING NOTICE(S) in position to tell persons not to supply the ground air.
D. Get Access
(1) Open the FWD cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-001).
(2) Put the ACCESS PLATFORM 2M (6 FT) in position at the FWD cargo-compartment door 825.
(3) Remove the access panels at partition FR34 (Ref. AMM D/O 06-41-53-00), (Ref. AMM TASK 25-54-12-000-001).
4. Procedure(1) Open the FWD cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-001).
(2) Put the ACCESS PLATFORM 2M (6 FT) in position at the FWD cargo-compartment door 825.
(3) Remove the access panels at partition FR34 (Ref. AMM D/O 06-41-53-00), (Ref. AMM TASK 25-54-12-000-001).
Subtask 21-21-43-020-051-A
A. Removal of the Lower Part of the Mixer Unit
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Remove the clamp (3) and disconnect the sleeve (2).
(4) Remove the clamps (7) and disconnect the sleeves (6).
(5) Remove the nut (17), the washers (18) and the bolt (19).
(6) Disconnect the tie rod (16) from the lower part of the mixer unit (8).
(7) Remove the nuts (10), the washers (11) and the screws (13) from the top of the mixer unit (14).
(8) Hold the lower part of the mixer unit (8) in position and remove the bolts (4) and the washers (5).
(9) Remove the lower part of the mixer unit (8) from the aircraft structure.
(10) Remove and discard the seal (12).
(11) Put a PLUG - BLANKING on the open end of:
CAUTION:
MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT.
(1) Disconnect the electrical connectors (1), (9) and (15). (2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Remove the clamp (3) and disconnect the sleeve (2).
(4) Remove the clamps (7) and disconnect the sleeves (6).
(5) Remove the nut (17), the washers (18) and the bolt (19).
(6) Disconnect the tie rod (16) from the lower part of the mixer unit (8).
(7) Remove the nuts (10), the washers (11) and the screws (13) from the top of the mixer unit (14).
(8) Hold the lower part of the mixer unit (8) in position and remove the bolts (4) and the washers (5).
(9) Remove the lower part of the mixer unit (8) from the aircraft structure.
(10) Remove and discard the seal (12).
(11) Put a PLUG - BLANKING on the open end of:
- The lower part of the mixer unit (8)
- The upper part of the mixer unit (14)
- The sleeves (2) and (6).
Lower Part of the Mixer Unit