Repair of Drain Mast System

TASK 49-17-00-300-001-A
Repair of Drain Mast System

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 4M (13 FT)-ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

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 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 49-16-45-000-003-A	Removal of the Air Intake Diffuser and Elbow (131-9(A))
TASK 49-16-45-400-003-A	Installation of the Air Intake Diffuser and Elbow (131-9(A))
TASK 52-41-00-010-001-A	Open the APU Doors for Access
TASK 52-41-00-410-001-A	Close the APU Doors after Access
TASK 52-41-22-000-001-A	Removal of the APU Access Door and the related Door Mechanism
TASK 52-41-22-400-001-A	Installation of the APU Access Door and the related Door Mechanism
Drain Mast Assy

3. Job Set-up
Subtask 49-17-00-860-050-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Put the warning notices on panel 25VU to tell persons not to start the APU.
(2) Energize the ground service network (Ref. AMM TASK 24-41-00-861-002).
(3) Make sure that the hydraulic systems are depressurized (Ref. AMM TASK 29-00-00-864-001).

Subtask 49-17-00-865-052-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-17-00-010-051-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE below the access doors 315AL and 316AR.
(2) Open the APU access doors 315AL, 316AR. (Ref. AMM TASK 52-41-00-010-001)
(3) Set the light switch 11LJ to on.
(4) Remove the Air Intake Diffuser and Elbow (Ref. AMM TASK 49-16-45-000-003).
(5) If necessary remove the APU access door 316AR (Ref. AMM TASK 52-41-22-000-001).

4. Procedure
Subtask 49-17-00-300-050-A ** ON A/C NOT FOR ALL

A. Repair of the Drain Mast System
(1) Carefully remove rivets (2-6) of the Drain Mast Assembly (7).
(2) Remove drilled-out rivets and drilling chips.
(3) Clean new structure parts before installation
(4) Surface protection and sealant has to be restored in accordance to SRM 51-72-11.
(5) Put Drain Mast Assembly (7) in position and install with same rivet type to Access Door Assembly. If oversize rivet types are necessary for installation use standards detailed in table 1.

5. Close-up
Subtask 49-17-00-410-051-A ** ON A/C NOT FOR ALL

A. Close Access
(1) If removed install the APU access door 316AR (Ref. AMM TASK 52-41-22-400-001).
(2) Install the Air Intake Diffuser and Elbow (Ref. AMM TASK 49-16-45-400-003).
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Set the light switch 11LJ to off.
(5) Close the APU access doors 316AR 315AL (Ref. AMM TASK 52-41-00-410-001) .
(6) Remove the access platform(s).

Subtask 49-17-00-865-053-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
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-17-00-860-051-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration.
(1) De-energize the ground service network (Ref. AMM TASK 24-41-00-862-002)
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.01 01:28:28 UTC