Installation of the Latching Unit

TASK 52-31-21-400-013-A
Installation of the Latching Unit

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

CAUTION: IMMEDIATELY AFTER YOU OPEN THE CARGO COMPARTMENT DOOR, RECORD ON THE WORK CARD ON THE DOOR, THE DATE AND TIME WHEN YOU OPENED IT. IF THE CARGO COMPARTMENT DOOR STAYS OPEN FOR 12 HOURS OR MORE, YOU MUST BLEED THE HYDRAULIC SYSTEM RELATED TO IT. IF YOU DO NOT OBEY THESE PRECAUTIONS, THE DOOR CAN CLOSE SUDDENLY WHEN YOU SET THE DOOR TO "CLOSE". THIS CAN CAUSE DAMAGE TO THE DOOR AND TO THE AIRCRAFT STRUCTURE.

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

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03HBD9)	Synthetic Ester base Grease-General Purpose Low Temp -
(Material No.12ABB1)	Corrosion Preventive Compound-Water Displacing Hard Film -
(Material No.12ABC1)	Corrosion Preventive Compound_Water Displacing Soft Film -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
825AR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
206	COTTER PIN	AIPC 52-31-21-34-030
203	COTTER PIN	AIPC 52-31-21-34-150
172	COTTER PIN	AIPC 52-31-21-34-240
221	COTTER PIN	AIPC 52-31-21-40-040
223	COTTER PIN	AIPC 52-31-21-40-040
225	COTTER PIN	AIPC 52-31-21-40-040
206	COTTER PIN	AIPC 52-31-82-44-030
203	COTTER PIN	AIPC 52-31-82-44-160
172	COTTER PIN	AIPC 52-31-82-44-230

E. Referenced Information

REFERENCE	DESIGNATION
TASK 12-22-52-640-002-A	Lubrication of Cargo Door
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-31-00-720-001-A	Functional Check of Forward Cargo Compartment Door, Comprising Functional Checks of Locking Mechanism, Interlock Mechanism, Drift Pin Mechanism and Safety Mechanism
TASK 52-31-11-820-002-A	Adjustment of the Door Mechanism
Latching Unit

3. Job Set-up
Subtask 52-31-21-860-067-A

A. Aircraft Maintenance Configuration
(1) Make sure that the FWD cargo-compartment door (referred to as cargo door) is opened and safetied with the actuator safety locks (Ref. AMM TASK 52-30-00-860-001).
(2) Make sure that the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the opened cargo door.
(3) Make sure that the access panel 825AR is removed from the cargo door.

Subtask 52-31-21-865-084-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
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N31
** ON A/C ALL
122VU	DOORS/CARGO	1MJ	T12
123VU	Y HYD/ELEC/PUMP	3802GX	AB06
123VU	Y HYD/ELEC/ELEC PUMP/NORM	3801GX	AB03

4. Procedure
Subtask 52-31-21-910-064-A

A. Preparation for Installation
(1) Make sure that the parts retained from the removed component are clean and in the correct condition.
(2) Clean the component interfaces and the adjacent area.
(3) Do an inspection of the component interfaces and the adjacent area.
(4) Apply a layer of Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to:

the inner and outer sliding surfaces of the sleeves (211),(214),(229),(240),
the sliding surfaces of the bushes (181), (209), (216), (228), (230), (235), (236), (241) and (239),
the shaft of all other bolts.

Subtask 52-31-21-420-075-A

B. Assembly of the Latching Unit
(1) Assemble the bellcrank (215) on the bellcrank lever (234) as follows:
(a) Install the sleeves (240) in the bellcrank (215).
(b) Install the bushes (239) and (241) in the upper fork end of the bellcrank lever (234).
(c) Put the bellcrank (215) in position in the upper fork end of the bellcrank lever(234).
(d) Install the bolt (232), the washers (233) and the nut (224).
(e) Tighten the nut (224) and safety it with the new AIPC 52-31-21-40-040 COTTER PIN (223).
(2) Connect the bellcrank (215) to the link rod (181) as follows:
(a) Put the lower eye-end of the link rod (181) on the fork-end of the bellcrank (215).
(b) Install the bolt (237), the washers (238), the bushes (239) and (241) and the nut (222) on the bellcrank lever (215).
(c) Tighten the nut (222) and safety it with the new AIPC 52-31-21-40-040 COTTER PIN (221).
(3) Assemble the latch hook (210) on the bellcrank lever (234) as follows:
(a) Install the sleeve (229) in the latch hook (210).
(b) Install the bushes (228) and (230) in the lower fork-end of the bellcrank lever (234).
(c) Put the latch hook (210) in the lower fork end of the bellcrank lever (234) and install the bolt (231), the washers (227) and the nut (226).
(d) Tighten the nut (226) and safety it with the new AIPC 52-31-21-40-040 COTTER PIN (225).

Subtask 52-31-21-420-076-A

C. Installation of the Latching Unit
(1) Connect the link rod (181) to the link lever (175)as follows:
(a) Put the eye-end of the link rod (181) to the fork-end of the link lever (175)
(b) Install the bolt (178), the washers (179), the bushes (180) and (182) and the nut (173).
(c) Tighten the nut (173) and safety it with the new AIPC 52-31-21-34-240 COTTER PIN (172) or AIPC 52-31-82-44-230 COTTER PIN (172).
(2) Attach the bellcrank (215) to the cargo door frame as follows:
(a) Install the bush (216) into the cargo door frame .
(b) Move the bellcrank (215) inboard until you can install the sleeve (214) correctly.
(c) Install the sleeve (214), bolt (213), the washers (205) and the nut (204).
(d) Tighten the nut (204) and safety it with the new AIPC 52-31-21-34-150 COTTER PIN (203) or AIPC 52-31-82-44-160 COTTER PIN (203).
(3) Attach the bellcrank (215) to the cargo door frame as follows:
(a) Install the bushes (209) into the cargo door door frame.
(b) Assemble the sleeve (211) into the latch hook (210).
(c) Move the latch hook (210) inboard until you can install the bolt (212).
(d) Install the bolt (212), the washers (208) and the nut (207).
(e) Tighten the nut (207) and safety it with the new cotter pin (206).
(f) Tighten the nut (207) and safety it with the new AIPC 52-31-21-34-030 COTTER PIN (206) or AIPC 52-31-82-44-030 COTTER PIN (206).
(4) Install the travel limit bolt (217), the washers (201) and the nut (202).

Subtask 52-31-21-820-062-A

D. Adjustment Procedure
(1) Adjust the length of the link rod (181) until the lower dead center of the applicable latching unit is correct (Ref. AMM TASK 52-31-11-820-002).
(2) Make sure that the latching units are correctly lubricated after the final adjustment. (Ref. AMM TASK 12-22-52-640-002).

Subtask 52-31-21-720-061-A

E. Do the functional test of the latching mechanism (Ref. AMM TASK 52-31-00-720-001).

5. Close-up
Subtask 52-31-21-865-085-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
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N31
** ON A/C ALL
122VU	DOORS/CARGO	1MJ	T12
123VU	Y HYD/ELEC/PUMP	3802GX	AB06
123VU	Y HYD/ELEC/ELEC PUMP/NORM	3801GX	AB03

Subtask 52-31-21-410-071-A

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Apply Corrosion Preventive Compound_Water Displacing Soft Film - (Material No.12ABC1) or Corrosion Preventive Compound-Water Displacing Hard Film - (Material No.12ABB1) to all the components of the locking units and to the adjacent cargo
(3) Install the access panel 825AR on the cargo door.
(4) Remove the actuator safety locks and close the FWD cargo door (Ref. AMM TASK 52-30-00-860-002).
(5) Remove the access platform(s).

[Rev.10 from 2021] 2026.04.02 06:27:54 UTC