Removal of the Drain Mast

TASK 30-71-51-000-001-A
Removal of the Drain Mast

WARNING: ISOLATE THE ELECTRICAL CIRCUITS FROM THE RELATED EQUIPMENT AND THE ENVIRONMENT.

FIN: 14DU
FIN: 24DU ** ON A/C NOT FOR ALL
FIN: 4DU

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	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
FOR [14DU] (DRAINMAST "F")
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
FOR [14DU] (DRAINMAST "F")
FOR [24DU] (DRAINMAST "F")
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
FOR [4DU] (DRAINMAST "F")
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [14DU] (DRAINMAST "F")
162DW
FOR [14DU] (DRAINMAST "F")
FOR [24DU] (DRAINMAST "F")
151GF, 162DW
FOR [4DU] (DRAINMAST "F")
131EF
131SF
131CG

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
Drain Mast ** ON A/C NOT FOR ALL
Drain Mast ** ON A/C NOT FOR ALL
Drain Mast ** ON A/C NOT FOR ALL
Drain Mast ** ON A/C NOT FOR ALL
Drain Mast ** ON A/C NOT FOR ALL
FOR [14DU] (DRAINMAST "F")
TASK 25-55-12-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR65
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
FOR [14DU] (DRAINMAST "F")
FOR [24DU] (DRAINMAST "F")
TASK 25-55-12-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR65
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
TASK 53-42-14-000-001-A	Removal of the Aft Cargo-Compartment Floor-Panels Zone 150
FOR [14DU] (DRAINMAST "F")
FOR [4DU] (DRAINMAST "F")
TASK 38-10-00-614-002-A	Depressurization of the Potable Water System
FOR [14DU] (DRAINMAST "F")
FOR [24DU] (DRAINMAST "F")
FOR [4DU] (DRAINMAST "F")
TASK 38-10-00-614-002-A	Depressurization of the Potable Water System
FOR [4DU] (DRAINMAST "F")
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
TASK 53-22-14-000-001-A	Removal of the Forward Cargo-Compartment Floor-Panels

3. Job Set-up
Subtask 30-71-51-861-051-A

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

Subtask 30-71-51-865-059-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
2000VU	WASTE WIP-DRAINMAST-FWD	1DU	B06
** ON A/C NOT FOR ALL
2000VU	DRAINMAST-FWD	1DU	B03
** ON A/C NOT FOR ALL
2000VU	WASTE WIP-DRAINMAST-FWD	1DU	B03
2000VU	WASTE WIP-HEATER-CTL	9DU	B02
2000VU	WASTE WIP-HEATER-LINE	8DU	B01
** ON A/C NOT FOR ALL
2000VU	WASTE WIP-HEATER-CTL	9DU	B05
2000VU	WASTE WIP-HEATER-LINE	8DU	B04
** ON A/C NOT FOR ALL
2001VU	POT/WASTE WIP-HEATER-CTL	32DW	D02
** ON A/C NOT FOR ALL
2001VU	WASTE WIP-HEATER-LINE	31DU	E04
** ON A/C ALL
2001VU	WASTE WIP-DRAINMAST-AFT	11DU	E01
** ON A/C NOT FOR ALL
2001VU	POT/WASTE WIP HEATER CTL	32DW	D02
2001VU	WASTE WIP-HEATER-LINE	22DU	E04
2001VU	WASTE WIP-HEATER-CTL	10DU	E03
2001VU	WASTE WIP-DRAINMAST-MID	21DU	E02

Subtask 30-71-51-010-050-D ** ON A/C NOT FOR ALL

C. Get Access
(1) FOR [4DU] (DRAINMAST "F"), [14DU] (DRAINMAST "F")
(a) Depressurize the potable water system (Ref. AMM TASK 38-10-00-614-002).
(b) Operate the wash basin faucet to remove any remaining water still in the potable water lines.
(c) Make sure that the wash basin plug is installed in the wash basin drain-hole:

To prevent remaining water from the potable water lines to drain down to the drain mast.

(d) Operate the galley faucets to remove any remaining water still in the potable water lines.
(2) FOR [4DU] (DRAINMAST "F")
(a) Open the forward cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(b) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(c) Set cargo-compartment light switch 6LU to ON.
(d) Remove floor panel 131SF to get access to forward drain mast (4DU) (Ref. AMM TASK 53-22-14-000-001).
(3) FOR [14DU] (DRAINMAST "F")
(a) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(b) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(c) Set cargo-compartment light switch 8LU to ON.
(d) Remove partition 162DW to get access to aft drain mast (14DU) (Ref. AMM TASK 25-55-12-000-001).

Subtask 30-71-51-010-050-E ** ON A/C NOT FOR ALL

C. Get Access
(1) FOR [4DU] (DRAINMAST "F"), [14DU] (DRAINMAST "F"), [24DU] (DRAINMAST "F")
(a) Do the depressurization of the potable water system (Ref. AMM TASK 38-10-00-614-002).
(b) Operate the washbasin faucet to remove the remaining water from the potable water lines.
(c) Make sure that the washbasin plug is installed in the washbasin drain hole.
(d) Operate the galley faucets to remove the remaining water from the potable water lines.
(2) FOR [4DU] (DRAINMAST "F")
(a) Open the forward cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(b) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(c) Set cargo-compartment light switch 6LU to the ON position.
(d) Remove floor panel 131EF (Ref. AMM TASK 53-22-14-000-001).
(3) FOR [14DU] (DRAINMAST "F"), [24DU] (DRAINMAST "F")
(a) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(b) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(c) Set cargo-compartment light switch 8LU to the ON position.
(d) Remove partition 162DW (Ref. AMM TASK 25-55-12-000-001).
(e) Remove floor panel 151GF (Ref. AMM TASK 53-42-14-000-001).

Subtask 30-71-51-010-050-F ** ON A/C NOT FOR ALL

C. Get Access
(1) FOR [4DU] (DRAINMAST "F"), [14DU] (DRAINMAST "F")
(a) Do the depressurization of the potable water system (Ref. AMM TASK 38-10-00-614-002).
(b) Operate the washbasin faucet to remove the remaining water from the potable water lines.
(c) Make sure that the washbasin plug is installed in the washbasin drain hole.

NOTE: The washbasin plug prevents the remaining water in the water lines to flow to the drain mast.

(d) Operate the galley faucets to remove the remaining water from the potable water lines.
(2) FOR [4DU] (DRAINMAST "F")
(a) Open the forward cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(b) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(c) Set CARGO COMPT LIGHT switch 6LU to ON.
(d) Remove floor panel 131EF (Ref. AMM TASK 53-22-14-000-001).
(3) FOR [14DU] (DRAINMAST "F")
(a) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) or (Ref. AMM TASK 52-30-00-860-003).
(b) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(c) Set CARGO COMPT LIGHT switch 8LU to ON.
(d) Remove partition 162DW (Ref. AMM TASK 25-55-12-000-001).

Subtask 30-71-51-010-050-J ** ON A/C NOT FOR ALL

C. Get Access
(1) FOR [4DU] (DRAINMAST "F"), [14DU] (DRAINMAST "F")
(a) Release the pressure of the potable water system (Ref. AMM TASK 38-10-00-614-002).
(b) Operate the wash basin faucet to remove any remaining water still in the potable water lines.
(c) Make sure that the wash basin plug is installed in the wash basin drain hole, to prevent any remaining water still in the potable water lines draining down to the drain mast.
(d) Operate the galley faucets to remove any remaining water still in the potable water lines.
(2) FOR [4DU] (DRAINMAST "F")
(a) Open the FWD cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(b) Set the CARGO COMP LIGHT switch 6LU to ON.
(c) Remove the floor panel 131CG to get access to the DRAINMAST-FWD (4DU) (Ref. AMM TASK 53-22-14-000-001).
(3) FOR [14DU] (DRAINMAST "F")
(a) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at the DRAINMAST-AFT (14DU).
(b) Open the AFT cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(c) Set the CARGO COMP LIGHT switch 8LU to ON.
(d) Remove the partition 162DW to get access to the DRAINMAST-AFT (14DU).

4. Procedure
Subtask 30-71-51-020-050-B ** ON A/C NOT FOR ALL

A. Removal of the Drain Mast
(1) Remove and discard the cable ties from the electrical wires.

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.

(2) Disconnect the electrical connector (6) from the drain mast (1).
(3) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.

CAUTION: BE VERY CAREFUL WHEN YOU REMOVE/INSTALL THE BELLOWS FROM /TO THE DRAIN MAST PIPE. IF YOU CAUSE DAMAGE TO THE BELLOWS YOU MUST REPLACE IT. TO REPLACE THE BELLOWS IT IS NECESSARY TO REMOVE THE CARGO FLOOR PANELS FOR ACCESS.

CAUTION: DO NOT USE TOOLS TO REMOVE/INSTALL THE BELLOWS FROM/TO THE DRAIN MAST PIPE. YOU CAN CAUSE DAMAGE TO THE DRAIN MAST PIPE VERY EASILY. IF YOU CAUSE DAMAGE TO THE DRAIN MAST PIPE, YOU MUST INSTALL A NEW DRAIN MAST.

(4) Remove the insulation from the pipe end (3).
(5) Loosen the clamps (4) and remove the sleeve (5) from the pipe end of the drain mast (1).
(6) Put the PLUG - BLANKING on the disconnected pipe end (3) in the aircraft.
(7) Remove the screws (2) from the drain mast (1).
(8) Carefully remove the drain mast (1) from the fuselage.

Subtask 30-71-51-020-050-C ** ON A/C NOT FOR ALL

A. Removal of the Drain Mast
(1) Remove the screws (2) from the drain mast (1).

(2) Carefully disconnect the extensible bellow (5) as follows:
(a) Loosen the screw of the clamp (4).
(b) Remove the clamp (4).
(c) Carefully and slowly disconnect the extensible bellow (5) from the drain mast pipe (6).
(d) Put the PLUG-BLANKING in each disconnected line end.

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.

(3) Disconnect the electrical connector (3).
(4) Carefully remove the drain mast (1) from the fuselage.
(5) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.

[Rev.10 from 2021] 2026.04.01 08:23:01 UTC