Detailed Inspection of Mechanical Parts of Door Locking Systems

TASK 52-51-00-220-001-A
Detailed Inspection of Mechanical Parts of Door Locking Systems

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 220

1. Reason for the Job
Refer to the MPD TASK: 525111-01
DETAILED INSPECTION OF MECHANICAL PARTS OF DOOR LOCKING SYSTEMS
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	BRUSH - BRISTLED, SOFT
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.08BBD1)	Non Aqueous Cleaner-- Isopropyl Alcohol -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
220	FWD CAB UTILITY AREAS

D. 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)
Mechanical Parts of the Cockpit Door

3. Job Set-up
Subtask 52-51-00-860-086-A

A. Aircraft Maintenance Configuration
(1) Make sure that the access to the cockpit is available.
(2) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 52-51-00-865-119-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
122VU	DOORS/PAX/MONG	1MQ	T13
** ON A/C NOT FOR ALL
122VU	DOORS CKPT LOCK	1MQ	T13
122VU	COCKPIT DOOR LOCK SYSTEM	1MQ	T13

Subtask 52-51-00-010-054-B

C. Get Access

Mechanical Parts of the Cockpit Door

(1) Remove the two rod covers (4) and (8) as follows:
(a) Remove the caps (1), (5) and (9) from the screws (2), (6) and (10).
(b) Remove the screws (2), (6) and (10) with the washers (3), (7) and (11) from the rod covers (4) and (8).
(c) Disconnect the rod covers (4) and (8) from the cockpit door (13).
(2) Remove the screws (20) and the cover profile (21) from the lavatory wall (17).
(3) Remove the screws (18) and the cover plates (19) from the lavatory wall (17).

4. Procedure
Subtask 52-51-00-110-050-B

A. Clean the Cockpit Door Bolting Mechanisms
(1) Clean the components that follow with a Textile-Lint free Cotton - (Material No.14SBA1) , or a BRUSH - BRISTLED, SOFT and the Non Aqueous Cleaner-- Isopropyl Alcohol - (Material No.08BBD1) :

The latch assemblies (25), (26) and (27)
The latch tenons (28)
The D-ring mechanism (30)
The connection rods (29)
The eye-ends (32)
The bellcrank levers (33).

(a) Dry the cleaned components with a dry and clean Textile-Lint free Cotton - (Material No.14SBA1) .

Subtask 52-51-00-220-054-B

B. Detailed Inspection of Mechanical Parts of Door Locking Systems
(1) Examine the electrical release strikes (22) for:

Wear and cracks of the catch (14) and the tab-lever (16)
Wear and broken coils of the spring (15)
Burned or broken wires of the electrical cables
Rough or worn areas of the cable insulation in the areas of the cables that you can see.

(2) Examine the door bolting systems for:

Wear, cracks, distortion and other damage of the latch assemblies (25), (26) and (27)
Wear, cracks and free movement of the latch tenons (28) of the latch assemblies (25), (26) and (27)
Cracks, distortion, free movement and other damage of the D-ring (30)
Cracks, wear, distortion and other damage of the eye-ends (32) and the bellcrank levers (33)
Missing or broken lockwire (31).

(3) If you find a defective component, replace it.

5. Close-up
Subtask 52-51-00-410-051-B

A. Installation of the Rod Covers
(1) Install the two rod covers (4) and (8) as follows:
(a) Put the rod covers (4) and (8) in their installation position of the cockpit door (13).
(b) Make sure that the mounting holes of the rod covers (4) and (8) align with the attachment holes of the mounting block (12).
(c) Attach rod covers (4) and (8) with the screws (2), (6) and (10) and the washers (3), (7) and (11).
(d) Install the caps (1), (5) and (9) on the screws (2), (6) and (10).
(2) Put the cover plates (19) in their installation positions on the lavatory wall housing (17) and install the screws (18).
(3) Put the cover profile (21) in the installation position on the lavatory wall housing (17) and install the screws (20).

Subtask 52-51-00-865-120-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
122VU	DOORS/PAX/MONG	1MQ	T13
** ON A/C NOT FOR ALL
122VU	DOORS CKPT LOCK	1MQ	T13
122VU	COCKPIT DOOR LOCK SYSTEM	1MQ	T13

Subtask 52-51-00-860-087-A

C. Put the aircraft back to the serviceable condition.
(1) Make sure that the cockpit door is open.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:28:24 UTC