EASA AD No.: 2012-0061R1

TE.CAP.00110-003 © European Aviation Safety Agency. All rights reserved. 1/3

Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.

EASA AIRWORTHINESS DIRECTIVE

AD No.: 2012-0061R1

Date: 30 November 2012

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with 

Regulation (EC) No 216/2008 on behalf of the European Community, its Member States and 

of the European third countries that participate in the activities of EASA under Article 66 of that 

Regulation.

This AD is issued in accordance with EU 748/2012, Part 21.A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the 

continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate 

an aircraft to which an AD applies, except in accordance with the requirements of that AD, unless otherwise specified by the Agency 

[EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption].

Design Approval Holder’s Name :

AIRBUS

Type/Model designation(s) :

A330-300 and A340-200/-300 aeroplanes

TCDS Numbers: EASA.A.004 and EASA.A.015

Foreign AD: Not applicable

Revision: This AD revises AD 2012-0061 dated 11 April 2012, including the Correction 

dated 12 April 2012.

ATA 27 Flight Controls – Trimmable Horizontal Stabilizer Actuator 

Ballscrew Lower Splines – Inspection / Replacement

Manufacturer(s): Airbus (formerly Airbus Industrie)

Applicability: Airbus A330-301, A330-302, A330-303, A330-321, A330-322, A330-323, 

A330-341, A330-342 and A330-343 aeroplanes, all manufacturer serial 

numbers (MSN).

Airbus A340-211, A340-212, A340-213, A340-311, A340-312 and A340-313

aeroplanes, all MSN.

Reason: Some Trimmable Horizontal Stabilizer Actuators (THSA), Part Number (P/N)

47147-500, have been found with corrosion, affecting the ballscrew lower 

splines between the tie bar and the screw-jack.

The results of the technical investigations have identified that the corrosion 

was caused by a combination of:

- Contact/friction between the tie bar and the inner surface of the ballscrew 

leading to the removal of Molykote (corrosion protection) at the level of the 

tie bar splines,

- Humidity ingress initiating surface oxidation starting from areas where 

Molykote is removed, and

- Water retention in THSA lower part leading to corrosion spread out and to 

the creation of a brown deposit (iron oxide).

The results of the technical investigations have also concluded that THSA P/N 

47147-500 and P/N 47147-700 ballscrews might be affected by this corrosion 

issue. 
EASA AD No.: 2012-0061R1

TE.CAP.00110-003 © European Aviation Safety Agency. All rights reserved. 2/3

Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.

THSA P/N 47147-400 ballscrews might be affected as well, but should no 

longer be in service, and modified into P/N 47147-500, as required by EASA 

AD 2010-0192 and EASA AD 2010-0193.

This condition, if not detected and corrected, may lead, in case of ballscrew 

rupture, to loss of transmission of THSA torque loads from the ballscrew to 

the tie-bar, prompting THSA blowback, possibly resulting in loss of control of 

the aeroplane.

To correct this potential unsafe condition, EASA issued AD 2012-0061 to

require repetitive visual inspections of the ballscrew lower splines of THSA 

having P/N 47147-500 or P/N 47147-700 to detect corrosion and, depending 

on findings, the accomplishment of applicable corrective actions.

Since that AD was issued, Airbus published new Service Bulletin (SB) A330-

27-3194 or Airbus SB A340-27-4187 (Airbus modification 202802), which 

allow installation in service of an improved THSA P/N 47172-530.

For the reasons described above, this AD is revised to specify that installation 

of THSA P/N 47172-530 is an alternative (optional) terminating action to the 

repetitive inspections required by this AD.

Effective Date: Revision 1: 07 December 2012

Original Issue: 25 April 2012

Required action(s) 

and Compliance 

Time(s):

Required as indicated, unless accomplished previously:

(1) Initially, within the compliance time indicated in Table 1 of this AD, as 

applicable, and thereafter, at intervals not to exceed 24 months, 

accomplish a visual inspection of the gaps between screw shaft and tie 

rod teeth of the THSA having P/N 47147-500 and P/N 47147-700, in 

accordance with the instructions of Airbus SB A330-27-3179 or SB A340-

27-4175, as applicable to aeroplane type.

Table 1 – Initial THSA inspection

Calendar time accumulated by 

the THSA, on 25 April 2012 [the 

effective date of the original issue 

of this AD] (See Note 1)

Compliance time

Less than 13 years since first 

flight on an aeroplane as THSA 

P/N 47147-400, or since the 

THSA first flight after its 

modification in accordance with 

the instructions of Airbus SB 

A330-27-3052 or Airbus SB 

A340-27-4059

Before accumulating 13 years, but 

not before accumulating 11 years 

since first flight on an aeroplane

as THSA P/N 47147-400 or since 

the THSA first flight after its 

modification in accordance with 

the instructions of Airbus SB 

A330-27-3052 or Airbus SB A340-

27-4059

(See Note 1)

Equal to or more than 13 years 

since first flight on an aeroplane

as THSA P/N 47147-400 or since 

the THSA first flight after its 

modification in accordance with 

the instructions of Airbus SB 

A330-27-3052 or Airbus SB 

A340-27-4059

Within 3 months after 25 April 

2012 [the effective date of the 

original issue of this AD]

Note 1: Some THSA P/N 47147-500 (and further derivative with P/N 47147-

700) were originally THSA P/N 47147-400 and were subsequently modified in 

service. In this case, the time accumulated by the THSA needs to be 

calculated from the first installation on aeroplane as THSA P/N 47147-400.
EASA AD No.: 2012-0061R1

TE.CAP.00110-003 © European Aviation Safety Agency. All rights reserved. 3/3

Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.

Some THSA P/N 47147-500 (and further derivative with P/N 47147-700) were 

originally THSA P/N 47147-200, -210, -213, -300, -303 or -350 and were 

subsequently modified in service in accordance with the instructions of Airbus 

SB A330-27-3052 or Airbus SB A340-27-4059. In this case, the time 

accumulated by the THSA needs to be calculated from the first flight on 

aeroplane after its modification in accordance with the instructions of Airbus 

SB A330-27-3052 or Airbus SB A340-27-4059.

(2) If, during any of the inspections as required by paragraph (1) of this AD, 

corrosion is found, replace the affected THSA with a serviceable part 

within the applicable compliance time as defined in Paragraph 1.E.(2) of 

Airbus SB A330-27-3179 or Airbus SB A340-27-4175, as applicable to 

aeroplane type.

(3) Replacement of a THSA with a THSA having P/N 47147-500 or P/N 

47147-700 does not constitute terminating action for the repetitive 

inspections as required by paragraph (1) of this AD.

(4) Modification of an aeroplane (installation of an improved THSA) in 

accordance with the instructions of:

- Airbus SB A330-27-3182 or Airbus SB A340-27-4178 (Airbus 

modification 200238), or

- Airbus SB A330-27-3194 or Airbus SB A340-27-4187 (Airbus 

modification 202802), 

as applicable to aeroplane type, constitutes terminating action for the 

repetitive inspections as required by paragraph (1) of this AD for that 

aeroplane.

(5) Within 90 days after accomplishment of each inspection as required by 

paragraph (1) of this AD, as applicable, report the results, including no 

findings, to Airbus.

(6) After 25 April 2012 [the effective date of the original issue of this AD], do 

not install a THSA having P/N 47147-500 or P/N 47147-700, unless the 

THSA is classified as Type 1 (no corrosion) in accordance with criteria 

defined in Airbus SB A330-27-3179 or Airbus SB A340-27-4175, and 

thereafter inspected and, depending on findings, corrected in compliance 

with the requirements of this AD.

Ref. Publications: Airbus SB A330-27-3179 at Original issue dated 14 February 2012.

Airbus SB A330-27-3052 at Original issue dated 9 July 1998.

Airbus SB A330-27-3182 at Original issue dated 14 February 2012.

Airbus SB A330-27-3194 at Original issue dated 08 October 2012.

Airbus SB A340-27-4175 at Original issue dated 14 February 2012.

Airbus SB A340-27-4059 at Original issue dated 28 July 1998.

Airbus SB A340-27-4178 at Original issue dated 14 February 2012.

Airbus SB A340-27-4187 at Original issue dated 08 October 2012.

The use of later approved revisions of these documents is acceptable for 

compliance with the requirements of this AD.

Remarks : 1. If requested and appropriately substantiated, EASA can approve 

Alternative Methods of Compliance for this AD.

2. Based on the required actions and the compliance time, EASA have 

decided to issue a Final AD with Request for Comments, postponing the 

public consultation process until after publication.

3. Enquiries regarding this AD should be referred to the Safety Information 

Section, Executive Directorate, EASA. E-mail ADs@easa.europa.eu

4. For any question concerning the technical content of the requirements in 

this AD, please contact AIRBUS – Airworthiness Office – EIAL; 

E-mail: airworthiness.A330-A340@airbus.com.