DOC AIRBUS | AMM A320FDetailed Inspection of THSA Ball Screw Shaft Lower Splines
TASK 27-44-51-220-802-A
Detailed Inspection of THSA Ball Screw Shaft Lower Splines
This inspection is necessary when the THSA is older than 20 years.
Refer to the OIT 999.0021/12-00 and ISB 27-1214 (and Vendor SB 47145-27-16).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 27-44-51-860-069-A ** ON A/C NOT FOR ALL
Subtask 27-44-51-110-050-A ** ON A/C NOT FOR ALL
Subtask 27-44-51-410-066-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.03.31 23:51:34 UTC
Detailed Inspection of THSA Ball Screw Shaft Lower Splines
WARNING:
PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:
- THE FLIGHT CONTROLS
- THE FLIGHT CONTROL SURFACES
- THE LANDING GEAR AND THE RELATED DOORS
- COMPONENTS THAT MOVE.
WARNING:
OBEY THE HYDRAULIC SAFETY PROCEDURES.
WARNING:
MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1. Reason for the JobThis inspection is necessary when the THSA is older than 20 years.
Refer to the OIT 999.0021/12-00 and ISB 27-1214 (and Vendor SB 47145-27-16).
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE |
| No specific | AR | MAT - PROTECTIVE |
| No specific | AR | SAFETY CLIP - CIRCUIT BREAKER |
| No specific | AR | WARNING NOTICE(S) |
| 0U190360 | 1 | PIN-RIGGING,THS ACTUATOR,MECHANICAL INPUT LEVER |
| 98D27403500000 | 1 | PITCH TRIM CONTROL LOCKING |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.08BAA9) | Non Aqueous Cleaner-General - - |
| (Material No.14SBA1) | Textile-Lint free Cotton - |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 310 | FUSLG TAIL SECTION AFT OF AFT PRESS BHD |
| 312AR |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 27-44-51-000-003-A | Removal of the Lower Claw Stop |
| TASK 27-44-51-400-003-A | Installation of the Lower Claw Stop |
| TASK 29-00-00-864-001-A | Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action |
Inspection Area of the THSA Ball Screw Shaft Lower SplinesSubtask 27-44-51-860-069-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
(1) Make sure that the THS actuator is in the zero position.
(a) Put the WARNING NOTICE(S) in the cockpit to tell persons not to operate the pitch controls.
(b) Put the 98D27403500000 PITCH TRIM CONTROL LOCKING on the pitch-trim control wheel in the cockpit.
(2) Depressurization of the hydraulic systems:
(a) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(b) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the Green and Yellow hydraulic systems:
Subtask 27-44-51-865-069-A ** ON A/C NOT FOR ALL (1) Make sure that the THS actuator is in the zero position.
(a) Put the WARNING NOTICE(S) in the cockpit to tell persons not to operate the pitch controls.
(b) Put the 98D27403500000 PITCH TRIM CONTROL LOCKING on the pitch-trim control wheel in the cockpit.
(2) Depressurization of the hydraulic systems:
(a) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(b) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the Green and Yellow hydraulic systems:
- In the cockpit on the hydraulic section 40VU of the overhead panel
- On the ground service panels of the Green and Yellow hydraulic systems.
B. Open, safety and tag this(these) circuit breaker(s):
Subtask 27-44-51-010-067-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/ELAC1/NORM/SPLY | 15CE1 | B11 |
| 49VU | FLIGHT CONTROLS/THS/ACTR/MOT2 | 19CE2 | B09 |
| 105VU | FLT CTL/ELAC1/STBY SPLY | 16CE1 | A01 |
| 121VU | FLIGHT CONTROLS/THS ACTR/MOT3 | 19CE3 | Q17 |
| 121VU | FLIGHT CONTROLS/THS ACTR/MOT1 | 19CE1 | Q16 |
C. Get Access
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position.
(2) Open the access door 312AR.
(3) Safety Precautions
(a) Put the 0U190360 PIN-RIGGING,THS ACTUATOR,MECHANICAL INPUT LEVER in the mechanical input of the THS actuator.
(b) Put a MAT - PROTECTIVE in the area of the THS actuator to prevent damage to the aircraft structure.
(4) Remove the lower claw stop (Ref. AMM TASK 27-44-51-000-003).
4. Procedure(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position.
(2) Open the access door 312AR.
(3) Safety Precautions
(a) Put the 0U190360 PIN-RIGGING,THS ACTUATOR,MECHANICAL INPUT LEVER in the mechanical input of the THS actuator.
(b) Put a MAT - PROTECTIVE in the area of the THS actuator to prevent damage to the aircraft structure.
(4) Remove the lower claw stop (Ref. AMM TASK 27-44-51-000-003).
Subtask 27-44-51-110-050-A ** ON A/C NOT FOR ALL
A. Cleaning
(1) Clean the inspection area with a Textile-Lint free Cotton - (Material No.14SBA1) and Non Aqueous Cleaner-General - - (Material No.08BAA9) (if necessary).
Subtask 27-44-51-220-060-A ** ON A/C NOT FOR ALL (1) Clean the inspection area with a Textile-Lint free Cotton - (Material No.14SBA1) and Non Aqueous Cleaner-General - - (Material No.08BAA9) (if necessary).
B. Detailed Inspection of the THSA Ball Screw after the Cleaning
(1) Do the detailed visual inspection, refer to the latest revision of ISB 27-1214.
5. Close-up(1) Do the detailed visual inspection, refer to the latest revision of ISB 27-1214.
Subtask 27-44-51-410-066-A ** ON A/C NOT FOR ALL
A. Close Access
(1) Install the lower claw stop (Ref. AMM TASK 27-44-51-400-003).
(a) Make sure that you do the test after the installation of the lower claw stop (refer also to the installation procedure above).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the access door 312AR.
Subtask 27-44-51-865-070-A ** ON A/C NOT FOR ALL (1) Install the lower claw stop (Ref. AMM TASK 27-44-51-400-003).
(a) Make sure that you do the test after the installation of the lower claw stop (refer also to the installation procedure above).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the access door 312AR.
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 27-44-51-860-070-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | FLIGHT CONTROLS/ELAC1/NORM/SPLY | 15CE1 | B11 |
| 49VU | FLIGHT CONTROLS/THS/ACTR/MOT2 | 19CE2 | B09 |
| 105VU | FLT CTL/ELAC1/STBY SPLY | 16CE1 | A01 |
| 121VU | FLIGHT CONTROLS/THS ACTR/MOT3 | 19CE3 | Q17 |
| 121VU | FLIGHT CONTROLS/THS ACTR/MOT1 | 19CE1 | Q16 |
C. Put the aircraft back to the serviceable condition.
(1) Remove the access platform(s).
(2) Remove the WARNING NOTICE(S).
(1) Remove the access platform(s).
(2) Remove the WARNING NOTICE(S).