Visual Inspection of the Drain Mast

TASK 30-71-51-200-001-A
Visual Inspection of the Drain Mast

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

B. 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 30-71-00-710-001-A	Operational Test of the Drainmast Ice Protection
TASK 30-71-51-000-001-A	Removal of the Drain Mast
TASK 30-71-51-400-001-A	Installation of the Drain Mast
Visual Inspection of Drain Mast (4DU, 14DU and 24DU) ** ON A/C NOT FOR ALL
Allowable Damage Limits for Drain Mast Fairing (4DU, 14DU and 24DU) ** ON A/C NOT FOR ALL
Visual Inspection of Drain Mast (4DU, 14DU and 24DU) ** ON A/C NOT FOR ALL
Allowable Damage Limits for Drain Mast Fairing (4DU, 14DU and 24DU) ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 30-71-51-860-051-A

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

Subtask 30-71-51-865-062-A

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

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
** ON A/C ALL
2001VU	WASTE WIP-DRAINMAST-AFT	11DU	E01
** ON A/C NOT FOR ALL
2001VU	WASTE WIP-DRAINMAST-MID	21DU	E02

Subtask 30-71-51-010-053-A

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at the related Drain Mast.

4. Procedure
Subtask 30-71-51-210-050-A

A. General
The drain mast cover is an aerodynamic cover made of aluminum. It has a wall thickness of 1.2 mm (0.0472 in.) (without corrosion-paint and lacquer).
(1) General requirements:
A serviceable drain mast must have:

No lateral deformation
No cracks
No scratches and abrasions with a depth of more than max. 50% of the cover material thickness 0.6 mm (0.0236 in.).

If the corrosion protection is damaged, make the scratches smooth.
Repair the surface protection and paint coating after repair of scratches and abrasion.
(2) Damage limits:

NOTE: If the dents depth in Zone 2 is less than 3.0 mm (0.1181 in.), no maintenance action (replacement) is necessary.

The drain mast cover is divided into 4 Zones with special zone-limits:

Zone 1: max. dent depth 0.0 mm (0.0000 in.)
Zone 2: max. dent depth 3.0 mm (0.1181 in.)
Zone 3: max. dent depth 0.0 mm (0.0000 in.)
Zone 4: max. dent depth 0.0 mm (0.0000 in.).

(3) Visual inspection of the drain mast:
Do a visual inspection of the drain mast for cracks, scratches, dents, deformation and abrasion.
Make sure that the bolts, which connect the drain mast to the fuselage, are tight.
Do a check of the adjacent area for damage.
(a) If you find scratches and abrasion with a depth less than 50% of the material thickness, 0.6 mm (0.0236 in.):

Do an operational test of the drain mast (Ref. AMM TASK 30-71-00-710-001) to make sure that the drain mast operates correctly.

1 If the operational test is correct and the corrosion protection is not damaged:

No additional test or replacement is necessary.

2 If the operational test is correct but the corrosion protection is damaged:

Remove the applicable drain mast (Ref. AMM TASK 30-71-51-000-001) and send it to the workshop to repair. After repair, install the drain mast (Ref. AMM TASK 30-71-51-400-001).

3 If the operational test is not correct:

Replace the related drain mast or only the cover or the heater tube assembly (Ref. AMM TASK 30-71-51-000-001) (Ref. AMM TASK 30-71-51-400-001).

(b) If you find cracks, scratches, dents, deformation and abrasion which are not in the given limits and zone-limits:

Replace the related drain mast or only the cover or the heater tube assembly (Ref. AMM TASK 30-71-51-000-001) (Ref. AMM TASK 30-71-51-400-001).

5. Close-up
Subtask 30-71-51-865-063-A

A. 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
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
** ON A/C ALL
2001VU	WASTE WIP-DRAINMAST-AFT	11DU	E01
** ON A/C NOT FOR ALL
2001VU	WASTE WIP-DRAINMAST-MID	21DU	E02

Subtask 30-71-51-860-052-A

B. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002)

Subtask 30-71-51-410-054-A

C. Close Access
(1) Remove the access platform.

[Rev.10 from 2021] 2026.04.01 00:32:02 UTC