SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 1/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

FLIGHT CONTROLS - TRIMMABLE HORIZONTAL STABILIZER ACTUATOR (THSA)

THSA SCREW SHAFT LOWER SPLINES INSPECTION

1. Planning information.

A. Effectivity.

This Service Bulletin concerns Trimmable Horizontal Stabilizer

Actuator (THSA) 47147-Series.

B. Concurrent requirements.

Not applicable

C. Reason.

This Service Bulletin describes the results of the engineering

investigation performed to treat the acceptable corrosion on the

lower splines of the THSA screw shaft.

D. Description.

On various THSA units corrosion marks have been found on the lower

splines of the screw shaft.

Those splines connect the THSA screw shaft and the fail safe tie

bar.

Those splines would be in use in case of the very unlikely rupture

of the THSA screw shaft.

NOTE: The fail safe tie bar is made of corrosion resistance steel,

so that there is no corrosion issue.

NOTE: Because the screw shaft/fail safe tie bar splines are not

loaded in normal operation, there is a gap between them.

E. Compliance.

(1) Inspection before THSA reaches 13 years since -400

(retrofit/new).

(2) For units >13 years, inspection within 3 months from AD

issuance.

F. Approval.

The technical content of this Service Bulletin has been approved

under the authority of the EASA Design Organisation Approval No.

EASA.21J.031
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 2/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

G. Manpower.

- Elastic claw stop removal = Half an hour

- Inspection = 1 hour

- Elastic claw stop re-installation = Half an hour

Total time = 2 manhours

H. Weight and balance.

Not changed.

I. Electrical load data.

Not changed.

J. Software accomplishment summary.

Not applicable.

K. References.

This SB is covered by aircraft Service Bulletins A330-27-3179 and

A340-27-4175

Under no circumstances shall the modified equipment, resulting

from the application of this SB, be installed on the aircraft type

unless the corresponding modification, and if applicable, its

aircraft SB are approved

L. Publications affected.

Not applicable.

M. Interchangeability or intermixability of parts.

Refer to Service Bulletins A330-27-3179 and A340-27-4175 .

2. Material information.

A. Material - Price and availability.

PNR KEYWORD QTY

Unit Price

(USD)

Validity

1/1/11

LEAD TIME

(DAYS)

FE194-044

(490315-100)

ELASTIC CLAW

STOP 1 14789.13 45(IF NEEDED)

FE194-000-21

(490273) TAB WASHER 1 677.12 7

FE194-000-36

(490062-100) SPRING WASHER 2 227.42 45(IF NEEDED)

NAS1351-3H6P

(4668-102) SCREW 2 1.73 7
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 3/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

B. Material necessary for each component.

(1) Material to be purchased.

NEW PNR KEYWORD OLD PNR QTY INSTRUCTIONS

FE194-000-21

(490273) TAB WASHER N/A 1 EXPANDABLEPART

FE194-000-36

(490062-100) SPRING WASHER N/A 2 EXPANDABLEPARTS

NAS1351-3H6P

(4668-102) SCREW N/A 2 EXPANDABLEPARTS

(2) Material supplied by the operator.

PNR KEYWORD QTY INSTRUCTIONS

23320CA080

(695011-080) LOCKWIRE AR F0111

C. Material necessary for each spare.

(1) Material to be purchased.

Refer to 2.B.(1) above.

(2) Material supplied by the operator.

Refer to 2.B.(2) above.

D. Reidentified parts.

Not applicable.

E. Tooling - Price and availability.

- Socket wrench 0U147991 Drawing Issue A.

- Zero setting tool 0U191066.

- Mechanical input rigging pin 0U191067.
∅ 41.3 + 0.1

+ 0

1.6259”

4XR1 0

-1

0.0394” 0

-0.0394”

+0.0079”

0

Material : 35NCD16 (BS-835M30)

(AISI 3135)

Strength : 900-1100 MPA

Red RAL 3027 Polyurethane

paint were indicated

Drawing of tool 0U147991

Figure 1

SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 4/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 5/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

3. Accomplishment instructions.

A. General view before dissasembly.

General view before dissasembly

Figure 2

Screws (3-50)

Lower elastic

claw stop (3-80

Tab washer (3-20)

Special nut (3-10)

Spring washer (3-30)
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 6/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

B. General view showing area to be inspected.

View showing area to be inspected after disassembly

Figure 3

A

B

C

NOTE: To perform the inspection, remove the two keys 3-70 (not

illustrated refer to IPL 27-44-55), and keep them for

re-installation.
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 7/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

C. Visual inspection of the lower end of the screw shaft on the

following area:

(1)Screw shaft internal splines end, see Figure 3 view A.

(2)Screw shaft bottom face, see Figure 3 view B.

(3)Screw shaft thread underneath the lower claw stop, see Figure

3 view C.

NOTE: The aim of this visual inspection is to classify level of

corrosion of the lower end of the screw shaft in 3 different

categories.

- Corrosion type III

- Corrosion type II

- Corrosion type I

D. Corrosion type criteria.

(1)CORROSION TYPE III

Without cleaning, inspect the gaps between screw shaft and

tie bar splines.

Corrosion type III is characterised by:

- Presence of a pasty brown compound generated by iron oxide.

- This compound is mainly localised between screw shaft and

tie rod lower splines.

- Corrosion is classified as type III, when compound fully

clogs lower splines gaps, i.e all SIX gaps are clogged by

pasty brown compound.
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 8/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

Screw shaft/tie bar cross section

Figure 4

Screw shaft

Fail safe tie bar

Schematic of type III

corrosion, all six gaps

are clogged by corrosion

Gap
View showing corrosion type III

Figure 5

View showing corrosion type III

Figure 6

Compound between inner

splines of the screw

shaft

Compound localized

inside thread end groove

of the tie rod

Compound localized

inside thread end groove

of the tie rod

Compound inside screw

shaft inner splines

SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 9/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 10/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

Screw shaft/tie bar cross section

Figure 7

Screw shaft

Fail safe tie bar

Schematic of type III corrosion,

all six edges of splines are

corroded/serrated

Edge
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 11/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

Clean screw shaft threads, bottom face of the screw and

elastic claw stop keys grooves with Isopropylic alcohol or

local approved solvent.

Corrosion is also classified as type III when ALL SIX screw

shaft splines are affected by corrosion.

Screw shaft splines corrosion is characterized by corrosion

pits along inner splines edges of the screw shaft. Edges are

serrated.

THSAs affected by corrosion type III must have screw shaft

integrity checked as per AMM task 27-44-51-220-801 and THSA

removed within 10 days.

View showing corrosion type III

Figure 8

All splines are oxidized

Edges of lower screw shaft splines are

serrated, corrosion pits are visible on

edges
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 12/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

Screw shaft/tie bar cross section

Figure 9

Screw shaft

Fail safe tie bar

Schematic of type II corrosion,

at least one edge of splines is

corroded/serrated

Edge
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 13/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

(2)CORROSION TYPE II

(a)Screw shaft splines corrosion is characterised by corrosion

pits along inner splines edges of the screw shaft. Edges

are serrated.

If at least one of the six screw shaft splines is not

affected by corrosion ,corrosion is classified as type II.

NOTE: if all SIX screw shaft splines are affected by

corrosion, corrosion is classified as type III.

Edges of lower screw shaft splines

are serrated, corrosion pits are

visible on edges

View showing corrosion type II

Figure 10
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 14/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

(b)Corrosion is also classified type II if:

NOTE: The first ten threads starting from the bottom of the

screw shaft are located under the elastic claw stop.

1 Corrosion pits are found on the lower thread of the screw

shaft. (refer to Figure 11).

View showing corrosion type II on lower threads

of the screw shaft

Figure 11

Presence of corrosion

on threads ends of

the screw shaft
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 15/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

2 Corrosion pits are found on the screw shaft key groove.

(refer to Figure 12).

View showing corrosion type II on key groove of

the screw shaft

Figure 12

Presence of

corrosion

on key groove
SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 16/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.

3 Corrosion pits are found on the screw shaft bottom face

(refer to Figure 13).

View showing corrosion type II on bottom face

of the screw shaft

Figure 13

Presence of corrosion

type II on lower surface

of the screw shaft

THSAs affected by corrosion type II must have screw shaft

integrity checked as per AMM task 27-44-51-220-801 and THSA

removed within 24 months or 4400 flight cycles (whichever

occurs first).

(3) CORROSION TYPE I

If the screw shaft lower splines/thread condition does not

meet any of the type III or type II condition, the screw

shaft is considered not corroded, classified as type I.

THSAs in condition type I must be re-checked as per Service

Bulletin 47147-27-18 every 24 months.

E. Close up

NOTE: Re-install the two keys 3-70.
Gap between splines

on the lower splines

ends fully clogged by

compound?

Yes

No

Yes Are all 6 splines

edges of the

screw

corroded?

No

Screw shaft integrity

checked as per

AMM task

27 ---44 ---51 ---220 ---801

Yes

No

Without cleaning, visual inspection of the

gaps between screw shaft and tie rod splines

Clean screw shaft threads, bottom face of

the screw and elastic claw stop key grooves

Visual inspection

Is corrosion shown on

lower face, thread,

splines edges and/or

key grooves?

Repeat check

within 24 months

Test is

successful

Test is

successful

Replace THSA

before further

flight

Replace THSA

before further

flight

Replace THSA

within

24 months/4400FC

Replace THSA

within 10 days

TYPE III

TYPE I

TYPE II

No

No

Yes

Yes

Screw shaft integrity

checked as per

AMM task

27 ---44 ---51 ---220 ---801

SERVICE BULLETIN

PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE

BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEX FRANCE FAX 33-1-34326310

Goodrich Actuation Systems FA3T1

Page 17/17

DATE : FEB 17/12

REVISION : 47147-27-18

The data and information contained in this document are the property of GOODRICH Actuation Systems. Copy and distribution to a third party are strictly forbidden.