# SERVICE BULLETIN PRODUCT SUPPORT DEPARTMENT 13, AVENUE DE L’EGUILLETTE -- SAINT-OUEN L’AUMONE BOITE POSTALE 7186 95056 CERGY PONTOISE CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 EXPANDABLE PART FE194-000-36 (490062-100) SPRING WASHER N/A 2 EXPANDABLE PARTS NAS1351-3H6P

(4668-102) SCREW N/A 2 EXPANDABLE PARTS (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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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

GapView 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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 CEDEXFRANCE 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.