EASA AD No.: 20 1 5

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TE. CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 1 / 2 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. 

## EASA AIRWORTHINESS DIRECTIVE

AD No

. : 20 1 5 - 0 0 8 0

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 E U 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 pers on 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, Arti cle 14(4) exemption]. 

### Design Approval Holder’s Name: AIRBUS Type/Model designation(s): A318, A319, A320 and A321 aeroplanes
TCDS Number: EASA.A.0 64
F oreign AD: Not applicable Supersedure: None



### ATA 27 Flight Controls

– Trimmable Horizontal Stabilizer Actuator

– Identification / Replacement
Manufacturer(s): Airbus (formerly Airbus Industrie) Applicability: Airbus A318

- 111, A318

- 112, A318

- 121, A318

- 122, A319

- 111, A319

- 112, A319

- 113, A319

- 114, A319

- 115, A319

- 131, A319

- 132, A319

- 133, A320

- 211, A320

- 212, A320

- 214, A320

- 215, A320

- 216, A320

- 231, A320

- 232, A320

- 233, A321

- 111, A321

- 112, A321

- 131, A321

- 211, A321

- 212, A321

- 213, A321

- 231 and A321

- 232 aero planes, all manufacturer serial numbers

. Reason: During endurance qualification tests on A380 Trimmable Horizontal Stabilizer Actuator (THSA), a partial loss of the no

- back brake (NBB) efficiency was experienced. Investigation results concluded that this particular malfunction was due to an ageing/endura nce issue of the surfaces of the NBB carbon friction disks, leading to a partial loss of braking efficiency in some specif ic aerodynamic load conditions. Due to design similarity on A320 family fleet, the same tests were initiated by the T HSA manufacturer on certain SA type T HSA, sampled from the field. Subject tests confirmed that T HSA Part Number (P/N) 4714 5 series, as installed on A320 family aeroplane s , are also affected by this partial loss of NBB efficiency. This condition, if not detected and corrected, an d in conjunction with the power gear train not able to keep the ball screw in its last commanded position, could lead to an uncommanded movement of the THS, possibly resulting in loss of control of the aeroplane

. For the reasons described abov e, this AD requires the removal from service of each affected T HSA , w ith the intent of in

- shop NBB carbon disk replacement.
Effective Date: 2 1 May 2015EASA AD No.: 20 1 5

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TE. CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 2 / 2 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. Required A ction(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 47145

- XXX (X XX in the P/N stands for any numerical value )

. Note 2: For the purpose of this AD, a serviceable THSA is a unit wh i c h 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 replacement , whichever is later

. NBB disc replacement can be accomplished through UTC Aerospace Systems (UTAS) Service Bulletin ( SB ) 47145

- 27

- 17

. (1) Not later than the date specified in Table 1 of this AD, as applicable, determine the FC accumulated by each affected THSA since first installation on an aeroplane , or since last NBB replacement (see N ote 3 of this AD) , whichever is later, and , for those having reached or exceeded on that date the corresponding number of FC specified in Table 1 of this AD , replace the THSA with a serviceable unit (see N ote 2 of this AD) in accordance with the instructions of Airbus SB A320

- 27

- 1242

. Note 3: 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 T HSA with a serviceable unit (see Note 2 of this AD) in accordance with the instructions of Airbus SB A3 2 0

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. 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 ) 31 December 2015 40 000 FC 31 December 2016 36 000 FC 31 December 2017 33 600 FC 31 December 2018 31 600 FC 31 December 2019 30 000 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 P/N 47145

- XXX on an aeroplane, provided the unit is a serviceable unit, as defined in Note 2 of this AD

. Ref. Public ations: Airbus SB A320

- 27

- 1242 original i ssue dated 09 February 2015

. UTAS SB 47145

- 27

- 17 original issue dated 16 February 2015

. The use of later approved revisions of th e s e document s 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. This AD was posted on 27 M arch 201 5 as PAD 15

- 0 2 8 for consultation until 2 4 April 2015

. The Comment Response Document can be found at http://ad.easa.europa.eu

. 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 conte nt of the requirements in this AD, please contact: AIRBUS

– Airworthiness Office

– EIAS, Fax +33 5 61 93 44 51, E

- mail: account.airworth

- eas@airbus.com

.