DOC AIRBUS | AMM A320FOperational Check Of Synchronized Locking Feedback Actuator (SLFA) for Locking Capability [CFML]
TASK 78-31-00-710-808-A
Operational Check Of Synchronized Locking Feedback Actuator (SLFA) for Locking Capability
Refer to the MPD TASK: 783100-L1
OPERATIONAL CHECK OF SYNCHRONIZED LOCKING FEEDBACK ACTUATOR (SLFA) FOR LOCKING CAPABILITY.
This procedure gives the instructions to do a check of the primary locks on the two upper actuators.
During this check you will lock one actuator at a time and then try to manually deploy the translating cowl (transcowl). The transcowl will not deploy if the lock functions correctly.
You must do a check of each of the two primary locks independently. In the first part of the check, the left actuator is locked and the right actuator is unlocked. In the second part of the check, the right actuator is locked and the left actuator is unlocked.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 78-31-00-941-066-A
Subtask 78-31-00-710-080-A
Subtask 78-31-00-440-059-A
[Rev.10 from 2021]
2026.04.01 03:34:58 UTC
Operational Check Of Synchronized Locking Feedback Actuator (SLFA) for Locking Capability
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.
ZONE: 400
1. Reason for the JobRefer to the MPD TASK: 783100-L1
OPERATIONAL CHECK OF SYNCHRONIZED LOCKING FEEDBACK ACTUATOR (SLFA) FOR LOCKING CAPABILITY.
This procedure gives the instructions to do a check of the primary locks on the two upper actuators.
During this check you will lock one actuator at a time and then try to manually deploy the translating cowl (transcowl). The transcowl will not deploy if the lock functions correctly.
You must do a check of each of the two primary locks independently. In the first part of the check, the left actuator is locked and the right actuator is unlocked. In the second part of the check, the right actuator is locked and the left actuator is unlocked.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE |
| No specific | 1 | INSPECTION CREEPER |
| No specific | AR | WARNING NOTICE(S) |
| No specific | 1 | WRENCH - SPEED, SQUARE DRIVE |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1) | |
| 437AL, 438AR | |
| FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2) | |
| 447AL, 448AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-803-A | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-803-A | Closing of the Fan Cowl Doors |
| TASK 78-30-00-040-807-A | Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU) |
| TASK 78-30-00-440-807-A | Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU) |
| TASK 78-31-41-000-804-A | Removal of the Thrust Reverser Left Hand Upper Actuator |
| TASK 78-31-41-000-805-A | Removal of the Thrust Reverser Right Hand Upper Actuator |
| TASK 78-31-41-040-802-A | Unlocking of the Thrust-Reverser Upper Actuators |
| TASK 78-31-41-400-804-A | Installation of the Thrust Reverser Left Hand Upper Actuator |
| TASK 78-31-41-400-805-A | Installation of the Thrust Reverser Right Hand Upper Actuator |
| TASK 78-31-41-440-802-A | Locking of the Thrust-Reverser Upper Actuators |
| TASK 78-31-43-440-802-A | Unlocking of the Right Lower Actuator (Synchronized Manual Locking Actuator) |
| TASK 78-32-50-410-801-A | Manually Stow the Translating Cowl |
| TASK 78-37-00-040-803-A | Deactivation of the Electrical Tertiary Lock System |
| TASK 78-37-00-440-803-A | Activation of the Electrical Tertiary Lock System |
Operation Check of the Primary Locking System (PLS)Subtask 78-31-00-941-066-A
A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put the WARNING NOTICE(S) in position to tell persons not to operate:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put the WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
Subtask 78-31-00-010-072-A (1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put the WARNING NOTICE(S) in position to tell persons not to operate:
- The ENG/MODE selector switch
- The ENG/MASTER 1(2) control switch.
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put the WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.
Subtask 78-31-00-040-063-A (1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.
C. Deactivation of the Thrust Reverser System for Maintenance
Subtask 78-31-00-040-064-A WARNING:
YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.
(1) Do the deactivation of the thrust reverser system for nacelle maintenance (Ref. AMM TASK 78-30-00-040-807). D. Deactivation of the electrical tertiary lock system
(1) Deactivate the electrical tertiary lock (Ref. AMM TASK 78-37-00-040-803).
Subtask 78-31-00-010-073-A (1) Deactivate the electrical tertiary lock (Ref. AMM TASK 78-37-00-040-803).
E. Make sure the thrust reverser is in the fully stowed position before you start this check. If it is not, manually stow the translating cowl (Ref. AMM TASK 78-32-50-410-801).
4. ProcedureSubtask 78-31-00-710-080-A
A. Operation Check of the Primary Locking System
(2) Put the ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position on the left side of the engine.
(3) Put the INSPECTION CREEPER in position under the thrust reverser.
(4) Make sure that the lock on the right lower Synchronized Manual Locking Actuator (SMLA) is unlocked (Ref. AMM TASK 78-31-43-440-802).
(5) Unlock the primary lock on the upper right Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-040-802).
(6) Make sure the primary lock on the upper left Synchronized Locking Feedback Actuator (SLFA) is in the LOCKED position (Ref. AMM TASK 78-31-41-040-802).
(7) Try to manually deploy the transcowl as follows:
(a) Put the WRENCH - SPEED, SQUARE DRIVE in the socket of one of the Manual Drive Units (MDUs). Make sure that the square drive of the WRENCH - SPEED, SQUARE DRIVE is fully engaged in the MDU.
(b) Turn the WRENCH - SPEED, SQUARE DRIVE until you hear a click (or a set of clicks).
(c) A click from the MDU tells you that the clutch has slipped. This tells you that the left primary lock works correctly.
(d) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the left primary lock. Replace the left upper Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-804) (Ref. AMM TASK 78-31-41-400-804).
(f) Put the WRENCH - SPEED, SQUARE DRIVE in the other MDU and turn it until you hear a click. A click from both the left and right MDUs tells you that the left primary lock is good.
(g) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the left primary lock. Replace the left upper actuator Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-804) (Ref. AMM TASK 78-31-41-400-804).
(8) Unlock the primary lock on the upper left Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-040-802).
(9) Lock the primary lock on the upper right Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-440-802).
(10) Make sure that the lock on the right lower Synchronized Manual Locking Actuator (SMLA) is unlocked (Ref. AMM TASK 78-31-43-440-802).
(11) Try to manually deploy the transcowl as follows:
(a) Put the WRENCH - SPEED, SQUARE DRIVE in the socket of one of the Manual Drive Units (MDUs). Make sure that the square drive of the WRENCH - SPEED, SQUARE DRIVE is fully engaged in the MDU.
(b) Turn the WRENCH - SPEED, SQUARE DRIVE until you hear a click (or a set of clicks).
(c) A click from the MDU tells you that the clutch has slipped. This tells you that the right primary lock works correctly.
(d) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the right primary lock. Replace the right upper Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-805) (Ref. AMM TASK 78-31-41-400-805).
(f) Put the WRENCH - SPEED, SQUARE DRIVE in the other MDU and turn it until you hear a click. A click from both the left and right MDUs tells you that the right primary lock is good.
(g) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the right primary lock. Replace the right upper actuator Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-805) (Ref. AMM TASK 78-31-41-400-805).
(12) Lock the primary lock on the upper left Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-440-802).
(13) Remove the access platform(s).
(14) Remove the INSPECTION CREEPER from under the thrust reverser.
5. Close-upCAUTION:
DO NOT OPEN THE THRUST REVERSER WHEN THE TRANSLATING COWL IS DEPLOYED BY MORE THAN 10 INCHES (254 MM). DO NOT DEPLOY THE TRANSLATING COWL WHEN THE THRUST REVERSER IS OPEN. WHEN THE THRUST REVERSER IS OPEN IT CAN HIT THE WING IF THE TRANSLATING COWL IS MOVED TO THE DEPLOYED POSITION. THIS CAN CAUSE DAMAGE TO THE THRUST REVERSER AND THE WING.
(1) Put the ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position on the right side of the engine. (2) Put the ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position on the left side of the engine.
(3) Put the INSPECTION CREEPER in position under the thrust reverser.
(4) Make sure that the lock on the right lower Synchronized Manual Locking Actuator (SMLA) is unlocked (Ref. AMM TASK 78-31-43-440-802).
(5) Unlock the primary lock on the upper right Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-040-802).
(6) Make sure the primary lock on the upper left Synchronized Locking Feedback Actuator (SLFA) is in the LOCKED position (Ref. AMM TASK 78-31-41-040-802).
(7) Try to manually deploy the transcowl as follows:
(a) Put the WRENCH - SPEED, SQUARE DRIVE in the socket of one of the Manual Drive Units (MDUs). Make sure that the square drive of the WRENCH - SPEED, SQUARE DRIVE is fully engaged in the MDU.
(b) Turn the WRENCH - SPEED, SQUARE DRIVE until you hear a click (or a set of clicks).
(c) A click from the MDU tells you that the clutch has slipped. This tells you that the left primary lock works correctly.
(d) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the left primary lock. Replace the left upper Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-804) (Ref. AMM TASK 78-31-41-400-804).
NOTE: In case of actuator replacement, repeat steps (7)(a) thru (7)(d).
(e) Remove the WRENCH - SPEED, SQUARE DRIVE from the MDU. (f) Put the WRENCH - SPEED, SQUARE DRIVE in the other MDU and turn it until you hear a click. A click from both the left and right MDUs tells you that the left primary lock is good.
(g) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the left primary lock. Replace the left upper actuator Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-804) (Ref. AMM TASK 78-31-41-400-804).
NOTE: In case of actuator replacement, repeat steps (7)(a) thru (7)(g).
(h) Remove the WRENCH - SPEED, SQUARE DRIVE from the MDU. (8) Unlock the primary lock on the upper left Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-040-802).
(9) Lock the primary lock on the upper right Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-440-802).
(10) Make sure that the lock on the right lower Synchronized Manual Locking Actuator (SMLA) is unlocked (Ref. AMM TASK 78-31-43-440-802).
(11) Try to manually deploy the transcowl as follows:
(a) Put the WRENCH - SPEED, SQUARE DRIVE in the socket of one of the Manual Drive Units (MDUs). Make sure that the square drive of the WRENCH - SPEED, SQUARE DRIVE is fully engaged in the MDU.
(b) Turn the WRENCH - SPEED, SQUARE DRIVE until you hear a click (or a set of clicks).
(c) A click from the MDU tells you that the clutch has slipped. This tells you that the right primary lock works correctly.
(d) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the right primary lock. Replace the right upper Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-805) (Ref. AMM TASK 78-31-41-400-805).
NOTE: In case of actuator replacement, repeat steps (11)(a) thru (11)(d).
(e) Remove the WRENCH - SPEED, SQUARE DRIVE from the MDU. (f) Put the WRENCH - SPEED, SQUARE DRIVE in the other MDU and turn it until you hear a click. A click from both the left and right MDUs tells you that the right primary lock is good.
(g) If the transcowl moves more than 0.5 in. (12.70 mm) before you hear a click, there is a problem with the right primary lock. Replace the right upper actuator Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-000-805) (Ref. AMM TASK 78-31-41-400-805).
NOTE: In case of actuator replacement, repeat steps (11)(a) thru (11)(g).
(h) Remove the WRENCH - SPEED, SQUARE DRIVE from the MDU. (12) Lock the primary lock on the upper left Synchronized Locking Feedback Actuator (SLFA) (Ref. AMM TASK 78-31-41-440-802).
(13) Remove the access platform(s).
(14) Remove the INSPECTION CREEPER from under the thrust reverser.
Subtask 78-31-00-440-059-A
A. Activation of the electrical tertiary lock system
(1) Activate the electrical tertiary lock (Ref. AMM TASK 78-37-00-440-803).
Subtask 78-31-00-440-060-A (1) Activate the electrical tertiary lock (Ref. AMM TASK 78-37-00-440-803).
B. Do the reactivation of the thrust reverser system after nacelle maintenance (Ref. AMM TASK 78-30-00-440-807).
Subtask 78-31-00-410-069-A C. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.
(3) Remove the WARNING NOTICE(S).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.
(3) Remove the WARNING NOTICE(S).