Removal of the Trimmable Horizontal Stabilizer (THS) Actuator

TASK 27-44-51-000-001-A
Removal of the Trimmable Horizontal Stabilizer (THS) Actuator

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.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

ZONE: 310
FIN: 9CE

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 3M (10 FT)- ADJUSTABLE
No specific	1	CAP - BLANKING
No specific	1	CONTAINER 5 L (1.32 USGAL)
No specific	1	COVER - BLANKING, HYDRAULIC RESISTANT
No specific	AR	MAT - PROTECTIVE
No specific	AR	PAD - PROTECTIVE FOAM
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	STEPLADDER 0.5 M (1.6 FT)
No specific	AR	TAPE - ADHESIVE
No specific	1	WARNING NOTICE(S)
No specific	1	WRENCH - STANDARD
0U145920	2	TOOL-MANUAL CRANKING STOP,THS ACTUATOR
0U190360	1	PIN-RIGGING,THS ACTUATOR,MECHANICAL INPUT LEVER
0U190834	1	TOOL-ZERO POSITIONING,THS ACTUATOR
0U190844	2	TOOL-RELEASE,POB
98D27403500000	1	PITCH TRIM CONTROL LOCKING
98D27407502000	1	SUPPORT STRUT-R I,THS ACTUATOR
98D27407517000	1	TOOL SET-R I,THS
98D27407533000	1	FRAME - THS ACTUATOR SUPPORT
OR	OR
98D27407533001	1	FRAME-THS ACTUATOR,SUPPORT
98D27408624000	1	DEVICE-R I,THS ACTUATOR
A1-91-265	1	HOIST-MINILIFT
A3-91-267	1	HOIST-MINILIFT,THS ACTUATOR

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
310	FUSLG TAIL SECTION AFT OF AFT PRESS BHD
312AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 27-44-51-000-802-A	Removal of the Electrical Load Sensing Device
TASK 27-44-51-710-001-A	Operational Check of THS Actuator No-Back Device
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-00-00-910-002-A	Safety Procedures of the Hydraulic System
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 29-23-00-863-001-A	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
TASK 29-23-00-863-002-A	Pressurize the Yellow Hydraulic System from the Green Hydraulic System through the PTU with the Ground Service Cart
Job Set-Up
Manual Cranking Stop Tool Installation
THS Actuator - Bonding Leads, Mechanical Input and Hydraulic Connections ** ON A/C NOT FOR ALL
THS Actuator - Bonding Leads, Mechanical Input and Hydraulic Connections ** ON A/C NOT FOR ALL
Electrical Connections
Primary Upper Attachment (for THSA P/N 47145-2XX) ** ON A/C NOT FOR ALL
Primary Upper Attachment (for THSA P/N 47145-1XX) ** ON A/C NOT FOR ALL
Removal and Installation Device 98D27408624000
Primary Lower Attachments

3. Job Set-up
Subtask 27-44-51-010-050-A

A. Get Access
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position.
(2) Open access door 312AR.

Subtask 27-44-51-860-050-A

B. Aircraft Maintenance Configuration

Job Set-Up

Manual Cranking Stop Tool Installation

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.

(1) If the hydraulic pressure is available:
(a) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(b) Pressurize the Green and the Yellow hydraulic systems (Ref. AMM TASK 29-23-00-863-001) or (Ref. AMM TASK 29-23-00-863-002).
(c) Turn the pitch-trim control wheel in the flight compartment and put the THS actuator (1) to the zero position.
(d) Depressurize the Green and Yellow hydraulic systems and put them in the maintenance configuration (Ref. AMM TASK 29-00-00-864-001).
(e) Depressurize the reservoirs of the Green and Yellow hydraulic systems.
(Ref. AMM TASK 29-14-00-614-001).
(f) 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.

(2) If the hydraulic pressure is not available:
(a) Depressurize the Green and Yellow systems and put them in the maintenance configuration (Ref. AMM TASK 29-00-00-864-001).
(b) Depressurize the reservoirs of the Green and Yellow hydraulic systems (Ref. AMM TASK 29-14-00-614-001).
(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.

(d) Use the 0U190844 TOOL-RELEASE,POB and a 1/2 inch socket to move the THS actuator (1) to the zero position (Ref. AMM TASK 27-44-51-710-001).
(3) Safety the THSA for removal:
(a) Put the 0U145920 TOOL-MANUAL CRANKING STOP,THS ACTUATOR (82) in position on the screw jack (83). Do this on each side of the nut assembly (2) of the THS actuator (1).
(b) Install and tighten the bolts (81).
(c) Put the WARNING NOTICE(S) in the flight compartment to tell persons not to operate the pitch controls.
(d) Put the 0U190360 PIN-RIGGING,THS ACTUATOR,MECHANICAL INPUT LEVER in the mechanical input of the THS actuator (1).
(e) Put the 0U190834 TOOL-ZERO POSITIONING,THS ACTUATOR between the THS actuator (1) and the nut assembly (2).
(f) Put the 98D27407502000 SUPPORT STRUT-R I,THS ACTUATOR in position and set the THS in the 0 deg. position.
(g) Put the 98D27403500000 PITCH TRIM CONTROL LOCKING on the pitch-trim control wheel in the flight compartment.
(h) Put the MAT - PROTECTIVE in the area of the THS actuator (1) to prevent damage to the aircraft structure.

Subtask 27-44-51-865-050-A

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

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
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/ELAC1/NORM/SPLY	15CE1	B06
49VU	FLIGHT CONTROLS/THS/ACTR/MOT2	19CE2	B04
** ON A/C ALL
105VU	FLT CTL/ELAC1/STBY SPLY	16CE1	A01
121VU	FLIGHT CONTROLS/THS ACTR/MOT3	19CE3	Q17
121VU	FLIGHT CONTROLS/THS ACTR/MOT1	19CE1	Q16

4. Procedure
Subtask 27-44-51-020-050-A

A. Removal of the Trimmable Horizontal Stabilizer (THS) Actuator
(1) Disconnect the bonding straps (20), (21) and (22) from the THS actuator (1):

THS Actuator - Bonding Leads, Mechanical Input and Hydraulic Connections ** ON A/C NOT FOR ALL

(a) Remove the nuts (25), washers (24) and bolts (23).
(b) Disconnect the bonding straps (20), (21) and (22) from the brackets (26), (27) and (28).
(c) Safety the bonding straps (20), (21) and (22) away from the THS actuator (1).
(2) Disconnect the mechanical system link-plate (29) from the input lever (30) of the THS actuator (1):

THS Actuator - Bonding Leads, Mechanical Input and Hydraulic Connections ** ON A/C NOT FOR ALL

(a) Remove and discard the cotter pins (37).
(b) Remove the nuts (38), the washers (39) and the bolts (40).
(c) Disconnect the link-plate (29) from the input lever (30).
(3) Disconnect the Green and the Yellow hydraulic systems from the THS actuator (1):

THS Actuator - Bonding Leads, Mechanical Input and Hydraulic Connections ** ON A/C NOT FOR ALL

CAUTION: PUT APPLICABLE COVERS ON THE ELECTRICAL EQUIPMENT TO PREVENT CONTAMINATION BY HYDRAULIC FLUID.

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT HYDRAULIC LINES ON UNIONS. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL LOOSEN OR TIGHTEN THE UNION TOO MUCH.

(a) Put the CONTAINER 5 L (1.32 USGAL) in position below the hydraulic valve blocks (31) and (34).
(b) Put the COVER - BLANKING, HYDRAULIC RESISTANT on the electrical equipment, which is installed in the area below the THS actuator (1).
(c) Disconnect the hoses from the Green hydraulic system:
1 Remove the lockwire:

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.

a Cut and remove the lockwire from the union nuts of the flexible hoses (32) and (33) to the valve block (31).
2 Disconnect the flexible hoses (32) and (33) from the high and the low pressure connections of the valve block (31).
3 Do a visual inspection of the flexible hoses (32) and (33).
4 Put the CAP - BLANKING on the flexible hoses (32) and (33).
5 Put the CAP - BLANKING on the open connections of the valve block (31).
6 Temporarily attach the flexible hoses (32) and (33) to the aircraft structure, clear of the THS actuator (1).
(d) Disconnect the hoses from the Yellow hydraulic system:
1 Remove the lockwire:

a Cut and remove the lockwire from the union nuts of the flexible hoses (35) and (36) to the valve block (34).
2 Disconnect the flexible hoses (35) and (36) from the high and the low pressure connections of the valve block (34).
3 Do a visual inspection of the flexible hoses (35) and (36).
4 Put the CAP - BLANKING on the flexible hoses (35) and (36).
5 Put the CAP - BLANKING on the open connections of the valve block (34).
6 Temporarily attach the flexible hoses (35) and (36) to the aircraft structure, clear of the THS actuator (1).
(e) Remove the container from below the hydraulic valve blocks (31) and (34).
(4) Disconnect the electrical connections from the THS actuator (1):

Electrical Connections

(a) Disconnect electrical connectors 9CE-E and 9CE-F (49) from the command Rotary Variable Differential Transducer (RVDT) (50).
(b) Disconnect electrical connectors 9CE-A, 9CE-B, 9CE-C and 9CE-D (51) from the pitch-trim actuator (52).
(c) Disconnect electrical connectors 9CE-G and 9CE-H (53) from the monitor RVDT (54).
(d) Put the CAP - BLANKING on the connections of the RVDTs (50) and (54) and the pitch-trim actuator (52).
(e) Do a visual inspection of the electrical connectors 9CE-A, 9CE-B, 9CE-C, 9CE-D, 9CE-E, 9CE-F, 9CE-G and 9CE-H.
(f) Put the CAP - BLANKING on the electrical connectors:

9CE-A, 9CE-B, 9CE-C, 9CE-D (51)
9CE-E, 9CE-F (49)
9CE-G, 9CE-H (53).

(5) Disconnect the primary upper attachment of the THS actuator (1):

Primary Upper Attachment (for THSA P/N 47145-2XX) ** ON A/C NOT FOR ALL

Primary Upper Attachment (for THSA P/N 47145-1XX) ** ON A/C NOT FOR ALL

(a) Remove the lockwire:

1 Cut and remove the lockwire from the left and the right screws (42).
(b) Remove the screws (42) and the washers (43). Make sure that the washer (45) and (if installed) the shim(s) (44) do not fall from the primary attachment.

NOTE: The washer (45) and (if applicable) the shim(s) (44) are loose in the primary attachment and can fall when you remove the screws (42).

(c) Move the bolts (46) away from the connection of the attachment forks (3) and the gimbal ring (41).
(d) Remove the washers (45) from between the bolts (46), the retainer nuts (47) and (if installed) the shim(s) (44). Identify the locations of the shim(s) (44) and the washers (45) to make the installation easier.
(e) Remove the bolts (46) from the connection of the attachment forks (3) and the gimbal ring (41).
(f) Safety the sliding bushes (48) in the attachment forks (3) with the TAPE - ADHESIVE.
(g) Safety the two spherical bearings (57) in the gimbal ring (41) with the TAPE - ADHESIVE.

NOTE: The adhesive tape safeties the bearings (57) during the maintenance or movement of the THS actuator.

(6) Do a visual inspection of the work area.
(a) Make sure that the items that follow are clean, not damaged and that they show no corrosion:

The attachment forks (3)
The attachment arms (4)
The mechanical input mechanism.

(7) Do a visual inspection of the attachment components that you will use again.
(a) Make sure that the items that follow are clean, not damaged and that they show no corrosion:

The bolts
The nuts
The bushes.

Subtask 27-44-51-480-050-A

B. Installation of the R/I-Device THS Actuator
(1) Put the 98D27408624000 DEVICE-R I,THS ACTUATOR in position. If necessary, use a STEPLADDER 0.5 M (1.6 FT) to help you install the device.

Removal and Installation Device 98D27408624000

(2) Connect transport rail 98D27408624040 to the applicable structure points at STA3451 (FR72) with the pip pins.
(3) Put adaptor 98D27408624110 between transport rail 98D27408624040 and the applicable structure point at STA3406 (FR71).
(4) Connect adaptor 98D27408624110 to the structure point at STA3406 (FR71) and to transport rail 98D27408624040 with the pip pins.
(5) Put rod 98D27408624042 in position at the applicable structure points at STA3406 (FR71).
(6) Connect rod 98D27408624042 to the structure points at STA3406 (FR71) with the pip pins.
(7) Connect transport frame 98D27408624046 to the roller assembly of transport rail 98D27408624040 with the pip pin.
(8) Put strives 98D27408624100 between rod 98D27408624042 and the brackets on transport frame 98D27408624046.
(9) Connect strives 98D27408624100 to rod 98D27408624042 and to transport frame 98D27408624046 with the pip pins.
(10) Move the roller assembly attached to transport frame 98D27408624046 along transport rail 98D27408624040 to the THS actuator (1).
(11) Put transport frame 98D27408624046 in position on the THS actuator (1).
(12) Connect transport frame 98D27408624046 to the THS actuator (1) with lifting adaptors 98D27408624258.
(13) Move the spindle nut, on the threaded rod of spindle 98D27408624118 to the center.
(14) Put spindle 98D27408624118 between rod 98D27408624042 and transport frame 98D27408624046.
(15) Connect spindle 98D27408624118 to rod 98D27408624042 and to transport frame 98D27408624046 with the pip pins.
(16) Install the A3-91-267 HOIST-MINILIFT,THS ACTUATOR on transport rail 98D27408624040.

NOTE: If the A3-91-267 HOIST-MINILIFT,THS ACTUATOR is not available, you can also use the A1-91-265 HOIST-MINILIFT.

(17) Connect fastener 98D27408624252 to the shackle of the A3-91-267 HOIST-MINILIFT,THS ACTUATOR with the pip pin.

Subtask 27-44-51-020-059-A ** ON A/C NOT FOR ALL

C. Removal of the THS Actuator (for THS Actuator P/N 47145-1XX)
(1) Disconnect the primary lower attachment of the THS actuator (1):

Primary Lower Attachments ** ON A/C NOT FOR ALL

(a) Remove and discard the cotter pins (65).
(b) Remove the nuts (66) from the connection of the left and right anti-rotation brackets (68) to the nut assembly (2).
(c) Remove the left and the right anti-rotation brackets (68).
(d) Install the nuts (66) again on the bolts (69) to hold the bolts (69) in position.
(e) Release the retainer washers (71) from the retainer nuts (70).
(f) Hold the secondary pins (74) with a WRENCH - STANDARD. Use a hook wrench, part of the 98D27407517000 TOOL SET-R I,THS, to remove the retainer nuts (70) from the secondary pins (74).
(g) Remove and discard the retainer washers (71).
(h) Release the retainer washers (73) from the retainer nuts (72).
(i) Hold the primary pins (75) with a WRENCH - STANDARD. Use a hook wrench, part of the 98D27407517000 TOOL SET-R I,THS, to remove the retainer nuts (72) from the primary pins (75).
(j) Remove and discard the retainer washers (73).
(k) Remove the secondary pins (74) and the primary pins (75) from the nut assembly (2).
(l) Move the bushes (77) in the direction of the screw shaft centerline, clear of the attachment arms (4).
(m) Put the PAD - PROTECTIVE FOAM on the valve outlets of the THS actuator (1). This is to prevent damage to the pressure bulkhead during the removal.
(2) Disconnect the secondary upper attachment (60) of the THS actuator (1):

Primary Upper Attachment (for THSA P/N 47145-1XX) ** ON A/C NOT FOR ALL

(a) Hold the THS actuator (1) with the spindle 98D27408624118.

Removal and Installation Device 98D27408624000 ** ON A/C NOT FOR ALL

(b) Remove and discard the cotter pins (61).
(c) Remove the parts that follow from the connection of the secondary upper attachment (60) and the structure:

The nuts (62)
The washers (63)
The bolts (64)
The bushes (80).

(3) Use the 98D27407502000 SUPPORT STRUT-R I,THS ACTUATOR, and put the stabilizer in the nose-up position (approximately -8°).
(4) Lower the THS actuator (1).
(5) Remove the spacers (76) from the attachment arms (4).

Primary Lower Attachments ** ON A/C NOT FOR ALL

(6) Remove the pip pin and disconnect spindle 98D27408624118 from transport frame 98D27408624046.

Removal and Installation Device 98D27408624000 ** ON A/C NOT FOR ALL

(7) Remove the pip pins and disconnect strives 98D27408624100 from transport frame 98D27408624046.

Removal and Installation Device 98D27408624000 ** ON A/C NOT FOR ALL

(8) Temporarily safety the bushes (77) and (78) in the nut assembly (2). Do this at the primary lower attachment with the TAPE - ADHESIVE.

Primary Lower Attachments ** ON A/C NOT FOR ALL

(9) Move the THS actuator (1) forward on transport rail 98D27408624040 to a position above access door 312AR.
(10) Connect fastener 98D27408624252 to the secondary upper attachment (60) with the pip pins.

Removal and Installation Device 98D27408624000 ** ON A/C NOT FOR ALL

(11) Remove lifting adaptors 98D27408624258 from the connection of transport frame 98D27408624046 to the THS actuator (1).

Removal and Installation Device 98D27408624000 ** ON A/C NOT FOR ALL

(12) Remove transport frame 98D27408624046.
(13) Put the 98D27407533000 FRAME - THS ACTUATOR SUPPORT98D27407533001 FRAME-THS ACTUATOR,SUPPORT in position below access door 312AR.
(14) Lower the THS actuator (1) through access door 312AR.
(15) Put the THS actuator (1) in position on the 98D27407533000 FRAME - THS ACTUATOR SUPPORT98D27407533001 FRAME-THS ACTUATOR,SUPPORT.
(16) Connect the THS actuator (1) to the 98D27407533000 FRAME - THS ACTUATOR SUPPORT98D27407533001 FRAME-THS ACTUATOR,SUPPORT as applicable.
(17) Remove the pip pins and disconnect the fastener 98D27408624252 from the secondary upper attachment (60).

Removal and Installation Device 98D27408624000 ** ON A/C NOT FOR ALL

(18) Remove the oil breather cap (7) from the oil filler plug (5) and install the storage cap (6).

Job Set-Up ** ON A/C NOT FOR ALL

Subtask 27-44-51-020-059-B ** ON A/C NOT FOR ALL

C. Removal of the THS Actuator (for THS Actuator P/N 47145-2XX)
(1) Disconnect the primary lower attachment of the THS actuator (1):

Primary Lower Attachments

Primary Upper Attachment (for THSA P/N 47145-2XX) ** ON A/C NOT FOR ALL

(a) Hold the THS actuator (1) with spindle 98D27408624118.

Removal and Installation Device 98D27408624000

(b) Remove the Electrical Load Sensing Device (ELSD) from the secondary upper attachment (60) of the THS actuator (Ref. AMM TASK 27-44-51-000-802).

NOTE: The ELSD is a part of THS actuator. If you send a removed THS actuator to the workshop, you must make sure that you send it together with its ELSD.

Primary Lower Attachments

(6) Remove the pip pin and disconnect spindle 98D27408624118 from transport frame 98D27408624046.

Removal and Installation Device 98D27408624000

(7) Remove the pip pins and disconnect strives 98D27408624100 from transport frame 98D27408624046.

Removal and Installation Device 98D27408624000

(8) Temporarily safety the bushes (77) and (78) in the nut assembly (2). Do this at the primary lower attachment with the TAPE - ADHESIVE.

Primary Lower Attachments

Removal and Installation Device 98D27408624000

(11) Remove lifting adaptors 98D27408624258 from the connection of transport frame 98D27408624046 to the THS actuator (1).

Removal and Installation Device 98D27408624000

(12) Remove transport frame 98D27408624046.
(13) Put the 98D27407533000 FRAME - THS ACTUATOR SUPPORT98D27407533001 FRAME-THS ACTUATOR,SUPPORT in position below access door 312AR.
(14) Lower the THS actuator (1) through access door 312AR.
(15) Put the THS actuator (1) in position on the 98D27407533000 FRAME - THS ACTUATOR SUPPORT98D27407533001 FRAME-THS ACTUATOR,SUPPORT.
(16) Connect the THS actuator (1) to the 98D27407533000 FRAME - THS ACTUATOR SUPPORT98D27407533001 FRAME-THS ACTUATOR,SUPPORT as applicable.
(17) Remove the pip pins and disconnect fastener 98D27408624252 from the secondary upper attachment (60).

Removal and Installation Device 98D27408624000

(18) Remove the oil breather cap (7) from the oil filler plug (5) and install the storage cap (6).

Job Set-Up

[Rev.10 from 2021] 2026.04.01 04:39:44 UTC