EASA AD No.: 2014-0218

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 1/3 Proprietary document. Copies are not controlled. Co nfirm revision status through the EASA-Internet/Int ranet. 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2014-0218

Date: 29 September 2014

Note: This Airworthiness Directive (AD) is issued b y EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the European Communit y, its Member States and of the European third countries that participate in the ac tivities of EASA under Article 66 of that Regulation.

This AD is issued in accordance with EU 748/2012, P art 21.A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the continuing airworthiness of an aircraft shall be en sured by accomplishing any applicable ADs. Conseque ntly, no person may operate an aircraft to which an AD applies, except in accordan ce with the requirements of that AD, unless otherwi se 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, A rticle 14(4) exemption].



### Design Approval Holder’s Name: SAAB AB, Aeronautics Type/Model designation(s): SF340A and 340B aeroplanes

TCDS Number: A.068

Foreign AD: Not applicable

Supersedure: This AD supersedes EASA AD 2013-0254 d ated 18 October 2013.



### ATA 27 Flight Controls – Stall Warning and Identification System / Stall

Warning Computer – Modification / Replacement

Manufacturer(s): SAAB AB, Aeronautics (formerly SAA B Aerosystems)

Applicability: Model SF340A aeroplanes serial numbe rs (s/n) 004 through 159 inclusive, and Model 340B aeroplanes s/n 160 through 459 inclusive , except aeroplanes registered in Canada which have been modified in ac cordance with SAAB AB modification (mod.) No. 2650 and/or mod. No. 2859. Note: This AD does not apply to Model 340B aeroplan es with s/n 170, 342, 362, 363, 367, 372, 379, 385, 395, 405, 409, 431, 4 41 and 455.

Reason: A few natural stall events, specifically wh en operating in icing conditions, have been experienced on SAAB 340 series aeroplanes, wit hout receiving a prior stall warning. This condition, if not corrected, could result in l oss of control of the aeroplane. To address this potential unsafe condition, SAAB de veloped a modified stall warning system, incorporating improved stall warnin g logic, and issued Service Bulletin (SB) 340-27-098 and SB 340-27-099, providi ng instructions to replace the Stall Warning Computer (SWC) with a new SWC, an d instructions to activate the new SWC. The new system included stall warning curves optimized for operation in icing conditions, which are activated by selection of Engine Anti-Ice. Consequently, EASA issued AD 2011-0219 to require i nstallation of the improved SWC. After that AD was issued, in-service experience wit h the improved stall warning system revealed cases of premature stall warning ac tivation during the take-offEASA AD No.: 2014-0218

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 2/3 Proprietary document. Copies are not controlled. Co nfirm revision status through the EASA-Internet/Int ranet. phase. In numerous recorded cases, the onset of sta ll warning occurred without the 6 minute delay after weight off wheels. This condition, if not corrected, could lead to pre mature stick shaker activation and consequent increase in pilot workload during th e take-off phase, possibly resulting in reduced control of the aeroplane. To correct this unsafe condition, EASA issued AD 20 13-0254 retaining the requirements of EASA AD 2011-0219, which was supers eded, to require deactivation of the ice speed curves in the improve d SWC on Saab 340 aeroplanes, in accordance with SAAB SB 340-27-116. Since EASA AD 2013-0254 was issued, SAAB developed a technical solution to eliminate the premature activation of the stall warning ice curves and issued SB 340-27-120 (modification of the existing Stall W arning System installation), SB 340-27-121 (activation of improved SWC for aerop lanes with a basic wing tip) and SB 340-27-122 (activation of improved SWC for aeroplanes with an extended wing tip). SAAB SB 340-27-120 provides mod ification and installation instructions valid for pre- and post-SB 340-27-097, SB 340-27-098, SB 340-27-099 and SB 340-27-116 aeroplanes. For aer oplanes modified in accordance with SAAB AB mod. No. 2650 and/or mod. N o. 2859 which are no longer registered in Canada, SAAB AB issued SAAB AB SB 340-27-109 to provide modification and installation instructions to remove the ice speed curve function. For the reasons described above, this AD retains th e requirements of EASA AD 2013-0254, which is superseded, and requires modifi cation of the Stall Warning and Identification System and replacement of the SW C with an improved unit.

Effective Date: 13 October 2014

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly: Requirements retained from EASA AD 2013-0254: (1) Within 30 days after 25 October 2013 [the effec tive date of EASA AD 2013-0254], accomplish the following actions, as ap plicable to aeroplane configuration, in accordance with the instructions of SAAB SB 340-27-116. (1.1) For aeroplanes with basic wing tip that have been modified in accordance with SAAB SB 340-27-098, deactivate the stall speed curves in the SWC part number (P/N) 0020AK6. (1.2) For aeroplanes with extended wing tip that ha ve been modified in accordance with SAAB SB 340-27-099, deactivate the stall speed curves in the SWC P/N 0020AK7. New requirements of this AD: (2) Within 18 months after the effective date of th is AD, accomplish the actions as specified in paragraph (2.1) or (2.2) of this AD , as applicable to aeroplane configuration. (2.1) For aeroplanes with a basic wing tip, replace the SWC with SWC P/N 0020AK6-1 in accordance with the instructions o f SAAB SB 340-27-121, or (2.2) For aeroplanes with an extended wing tip, rep lace the SWC with SWC P/N 0020AK7-1 in accordance with the instructio ns of SAAB SB 340-27-122. (3) Prior to, or concurrent with, modification of a n aeroplane as required by paragraph (2) of this AD, modify the Stall Warning and Identification System in accordance with the instructions of SAAB SB 340-27-120 or, for aeroplanes post-mod No 2650 and/or post-mod 2859, S B 340-27-109, as applicable for aeroplane configuration. (4) After modification of an aeroplane as required by paragraph (2) of this AD,EASA AD No.: 2014-0218

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 3/3 Proprietary document. Copies are not controlled. Co nfirm revision status through the EASA-Internet/Int ranet. do not install any SWC P/N 0020AK, or P/N 0020AK1, or P/N 0020AK2, or P/N 0020AK4, or P/N 0020AK3 MOD 1 P/N 0020AK6, or P /N 0020AK7 on that aeroplane.

Ref. Publications: SAAB SB 340-27-098 original issu e dated 01 September 2011. SAAB SB 340-27-099 original issue dated 01 Septembe r 2011. SAAB SB 340-27-116 original issue dated 18 October 2013. SAAB SB 340-27-120 original issue dated 11 July 201 4. SAAB SB 340-27-121 original issue dated 11 July 201 4. SAAB SB 340-27-122 original issue dated 11 July 201 4. SAAB SB 340-27-109 original issue dated 14 April 20 14. The use of later approved revisions of these docume nts is acceptable for compliance with the requirements of this AD.

Remarks: 1. If requested and appropriately substantiated, EA SA can approve Alternative Methods of Compliance for this AD. 2. This AD was posted on 21 July 2014 as PAD 14-118 for consultation until 18 August 2014. The Comment Response Document can b e found at http://ad.easa.europa.eu

. 3. Enquiries regarding this AD should be referred t o the Safety Information Section, Certification Directorate, EASA. E-mail: ADs@easa.europa.eu

. 4. For any question concerning the technical conten t of the requirements in this AD, please contact: Saab AB, Support and Services SE-581 88 Linköping, Sweden Fax: +46 13 184874 E-mail: saab340.techsupport@saabgroup.com

.