EASA AD No.: 2015-0081

TE.CAP.00110-004 © 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.: 2015-0081 

Date: 07 May 2015 

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 EU 1321/2014 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 [EU 

1321/2014 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): 

A300-600, A300-600ST and A310 aeroplanes 

TCDS Numbers: EASA.A.014 and EASA.A.172 

Foreign AD: Not applicable 

Supersedure: None 

ATA 27 Flight Controls – Trimmable Horizontal Stabilizer Actuator – 

Identification / Replacement 

Manufacturer(s): Airbus (formerly Airbus Industrie)

Applicability: Airbus A300 B4-601, A300 B4-603, A300 B4-620, A300 B4-622, 

A300 B4-605R, A300 B4-622R, A300 C4-605R variant F, A300 C4-620, 

A300 F4-605R, A300 F4-622R, A300 F4-608ST, A310-203, A310-203C, 

A310-204, A310-221, A310-222, A310-304, A310-308, A310-322, A310-324 

and A310-325, aeroplanes, all manufacturer serial numbers. 

Reason: During endurance qualification tests on a Trimmable Horizontal Stabilizer 

Actuator (THSA) concerning another aeroplane type, a partial loss of the noback brake (NBB) efficiency was experienced. Investigation results concluded 

that this partial loss of braking efficiency in some specific aerodynamic load 

conditions was due to polishing and auto-contamination of the NBB carbon 

friction disks. 

Due to design similarity on the A300-600, A300-600ST and A310 fleet, the 

same tests were initiated by the THSA manufacturer on certain type THSA, 

sampled from the field. Subject tests confirmed that THSA Part Number (P/N) 

47142 series, as installed on the A300-600, A300-600ST and A310 fleet, are 

also affected by this partial loss of NBB efficiency. 

This condition, if not detected and corrected, and in conjunction with the power 

gear not able to keep the ball screw in its last commanded position, could 

potentially lead to an uncommanded movement of the Horizontal Stabilizer, 

possibly resulting in loss of control of the aeroplane. 

For the reasons described above, this AD requires the removal from service of 

each affected THSA, with the intent of in-shop NBB carbon disk replacement. 

Effective Date: 21 May 2015 
EASA AD No.: 2015-0081

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 2/3 

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

Required Action(s) 

and Compliance 

Time(s): 

Required as indicated, unless accomplished previously: 

Note 1: The THSA affected by the requirements of this AD are only those 

identified by P/N 47142-403, 47142-413, 47142-414, or 47142-423. 

EASA AD 2010-0224 required installation of three secondary retention plates 

for the gimbal bearings on the THSA upper primary attachment, which involved 

a THSA P/N change from -300 series to -400 series. 

Note 2: For the purpose of this AD, a serviceable THSA is a unit (as identified 

in Note 1 of this AD), which has not exceeded the flight cycle (FC) limits 

specified in Table 1 of this AD, since first installation of the THSA on an 

aeroplane, or since last NBB disk replacement (see Note 4 of this AD), 

whichever is later; or a THSA with a different P/N, not affected by the 

requirements of this AD. 

Note 3: The life limits as specified in the current revision of ALS Part 4 are still 

relevant for the affected THSA, as applicable to aeroplane model. This AD 

addresses a replacement limit for the NBB disks installed on the THSA, not the 

life limit for the THSA itself. 

(1) Not later than the date specified in Table 1 of this AD, as applicable, 

determine the FC accumulated by each THSA since first installation on an 

aeroplane, or since last NBB replacement (see Note 4 of this AD), 

whichever is later, and, for those having reached or exceeded on that date 

the corresponding number of FC as specified in Table 1 of this AD, replace 

the THSA with a serviceable unit (see Note 2 of this AD) in accordance 

with the instructions of Airbus Service Bulletin (SB) A300-27-6070, or 

Airbus SB A300-27-9022, or Airbus SB A310-27-2106, as applicable. 

Note 4: In case no maintenance records concerning last NBB disk replacement 

are available, the FC accumulated since first installation of the THSA on an 

aeroplane apply. 

(2) From each date as specified in Table 1 of this AD, and before exceeding 

the FC limit corresponding to each date, as applicable, replace each THSA 

with a serviceable unit (see Note 2 of this AD) in accordance with the 

instructions of Airbus SB A300-27-6070, or Airbus SB A300-27-9022, or 

Airbus SB A310-27-2106, as applicable. 

Table 1 – THSA Removal for NBB Disks Replacement

Date 

THSA FC Limit (since first installation on an 

aeroplane, or since last NBB replacement, 

whichever is later) 

01 February 2016 30 000 FC 

01 February 2017 20 000 FC 

01 February 2019 14 600 FC 

Conditions for the installation of a THSA on an aeroplane: 

(3) From each date specified in Table 1 of this AD, as applicable, it is allowed 

to install a THSA on an aeroplane, provided the unit has not exceeded the 

corresponding number of FC specified in Table 1, since first installation on 

an aeroplane, or since last NBB replacement, whichever occurred later. 

Ref. Publications: Airbus SB A300-27-6070 original issue, dated 17 February 2015. 

Airbus SB A300-27-9022 original issue, dated 17 February 2015. 

Airbus SB A310-27-2106 original issue, dated 17 February 2015. 

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

compliance with the requirements of this AD. 
EASA AD No.: 2015-0081

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 3/3 

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

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

Alternative Methods of Compliance for this AD. 

2. This AD was posted on 30 March 2015 as PAD 15-029 for consultation 

until 27 April 2015. No comments were received during the consultation 

period. 

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

Section, Certification 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 – EIAW (Airworthiness Office), 

E-mail: continued.airworthiness-wb.external@airbus.com.