Adjustment of the Cockpit Door - Latch Mechanism

TASK 52-51-00-820-809-A
Adjustment of the Cockpit Door - Latch Mechanism

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
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	FLASHLIGHT
No specific	1	MIRROR - INSPECTION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	Torque wrench: range to between 0.374 and 0.306 m.daN (33.10 and 27.08 lbf.in )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.14QFB1)	Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -

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)
TASK 52-51-00-710-002-A	Operational Test of the Cockpit-Door Locking System (CDLS)
TASK 52-51-00-820-001-A	Adjustment of the Cockpit Door, Electrical Release Strikes and Latch Mechanisms
Cockpit Door - Adjustment of the Latch Mechanism

3. Job Set-up
Subtask 52-51-00-860-136-A

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

Subtask 52-51-00-865-153-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

4. Procedure
Subtask 52-51-00-820-062-A

A. Adjustment of the Cockpit Door - Latch Mechanism
(1) If necessary, use the FLASHLIGHT and/or the MIRROR - INSPECTION to do the adjustment of dimension Q.
(2) Close the cockpit door (1).
(3) Make sure that the D-ring (25) of the center latch mechanism (20) stays in its recess.
(4) Make sure that the top and bottom latch tenons (15) are in the fully closed position before the center latch tenon (21) engages.
(5) Adjust dimension Q of the center latch mechanism (20) as follows:

NOTE: Dimension Q is used to make sure that the center latch tenon (21) engages correctly in the catch (22) of the center electrical release-strike.

(a) Measure dimension Q of the center latch mechanism (20).
(b) Make sure that dimension Q is between 7 mm (0.2756 in.) and 9 mm (0.3543 in.).

NOTE: The rear face of the center latch tenon (21) has three arrow marks:

If you see no arrow mark when the cockpit door (1) is closed, then dimension Q is more than 9 mm (0.3543 in.).
If you can see more than one full arrow mark when the cockpit door (1) is closed, then dimension Q is less than 7 mm (0.2756 in.).

(c) If dimension Q of the center latch mechanism (20) is not correct, adjust it as follows:
1 Remove the plugs (23) from the screws (24).
2 Loosen the screws (24) and move the center latch mechanism (20) until dimension Q is correct.
3 Tighten the screws (24).
4 Install the plugs (23).
(6) Adjust dimensions Q of the top and lower latch mechanisms (14) as follows:

NOTE: Dimensions Q are used to make sure that the latch tenons (15) engage correctly in the catchs (16) of the upper and lower electrical release-strikes.

(a) Measure dimensions Q of the top and lower latch mechanisms (14).
(b) Make sure that dimensions Q are between 7 mm (0.2756 in.) and 9 mm (0.3543 in.).

NOTE: The rear face of each latch tenon (15) has three arrow marks:

If you see no arrow mark when the cockpit door (1) is closed, then dimension Q is more than 9 mm (0.3543 in.).
If you can see more than one full arrow mark when the cockpit door (1) is closed, than dimension Q is less than 7 mm (0.2756 in.).

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

CAUTION: USE THE DOUBLE WRENCHING PROCEDURE TO TORQUE THE JAM NUTS. USE ONE WRENCH ON THE JAM NUT AND A SECOND WRENCH ON THE ROD. ALSO MAKE SURE THAT YOU DO NOT APPLY TOO MUCH TORQUE TO THE JAM NUTS. IF YOU DO NOT USE THIS PROCEDURE, THE APPLIED TORQUE CAN TWIST THE BELL CRANK. IF YOU APPLY TOO MUCH TORQUE, THE BELL CRANK WILL BREAK.

1 Remove the two rod covers (5) and (12) as follows:
a Remove the caps (2), (8) and (9) from the screws (3), (7) and (10).
b Remove the screws (3), (7) and (10) together with the washers (4), (6) and (11) from the rod covers (5) and (12).
c Disconnect the rod covers (5) and (12) from the cockpit door (1).
2 Remove and discard the lockwire from the jam nuts (17) and the safety device (18).
3 Loosen the jam nuts (17) at each end of the connection rods (19).
4 Turn the connection rods (19) to adjust the latch tenons (15) and (21) correctly.

NOTE: The connection rods (19) have a right thread at one end and a left thread at the other end.
Thus, you can adjust their length if you turn the rods body.

5 TORQUE the jam nuts (17) against the rods body to between 0.374 and 0.306 m.daN (33.10 and 27.08 lbf.in )

.
6 Safety the jam nuts (17) with the 14QFB1Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - on the safety devices (18).
7 Install the rod covers (5) and (12) as follows:
a Put the rod covers (5) and (12) in their installation position on the cockpit door (1).
b Make sure that the mounting holes of the rod covers (5) and (12) align with the attachment holes of the mounting block (13).
c Attach the rod covers (5) and (12) with the washers (4), (6) and (11) and the screws (3), (7) and (10).
d Install the caps (2), (8) and (9) on the screws (3), (7) and (10).
(7) Do a visual check for the correct adjustment of the latch tenons (15) and (21).

NOTE: The rear face of each latch tenon has three arrow marks. If you can see only the last (inboard) full arrow-mark when the cockpit door is closed, then the adjustment is correct.

Subtask 52-51-00-865-160-A

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
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 52-51-00-710-073-A

C. Operational Test of the Cockpit Door and the Latch Mechanism
(1) Do an operational test of the cockpit door (1) and the latch mechanism (Ref. AMM TASK 52-51-00-710-002).
(2) If the results of the test are unsatisfactory or you cannot adjust dimension Q as in step 4.A:

Do the adjustment procedure of the cockpit door (1), the electrical release strikes and the latch mechanisms (Ref. AMM TASK 52-51-00-820-001).

5. Close-up
Subtask 52-51-00-860-137-A

A. Put the aircraft back to the serviceable condition.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 07:23:58 UTC