EASA AD No.: 20 11

- 02 1 9

E ASA Form 110 Page 1 / 2 

## EASA AIRWORTHINESS DIRECTIVE

AD No

. : 20 1 1

- 02 1 9

Date : 11 Novem ber 2011

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 EC 1702/2003, Part 21A.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 Age ncy [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]. 

### Type Approval Holder’s Name :

S AAB AB, Aero nautics Type/Model designation(s) :

SF 340 A and 340B aeroplanes

TCDS Num ber : EASA. A.06 8

F oreign AD : N ot applicable

Supersedure : N one



### ATA 27 Flight Controls

– Stall Warning/Identification System

– Replacement

Manufacturer(s): S AAB AB, Aeronautics (former ly S AAB Aerosystems ).

Applicability: Model SF 340A aeroplanes, serial number s (s/n) 004 th rough 159 inclusive, and Model 340B aeroplanes, s / n 160 through 459 inclusive, except aeroplanes that have SA A B Modification (Mod.) No. 2650 and/or Mod. No. 2859 installed

. Note: This AD does not apply to aeroplanes with s/n 170, 342, 362, 363, 367, 372, 3 79, 385, 395, 405, 409, 431 and 455.

Reason: A few n atural stall events , specifically when operating in icing conditions, ha ve been experienced on SAAB 340 series aeroplanes

, without receiving a prior stall warning

. This condition, if not corrected, could result in loss of control of the aeroplane

. To address this potential unsafe condition, a modified stall warning system

, incorporating improved stall warning logic, has been developed

. SAAB have issued Service Bulletin (SB) 340

- 27

- 098 and SB 340

- 27

- 099

, w hich include instructions to replace the present Stall Warning C omputer (SWC) with a new SWC

, and instructions to activate the new SWC . The new system includes stall warning curves optimized for operation in icing conditions , which are activated by selecti on of Engine Anti

- Ice

. For the reasons described above, this AD requires the replacement of the SWC

, by installing new SWC Part Number ( P/N ) 0020AK6 o n aeroplanes with basic wing tip , and installing a new SWC P/N 0020AK7 on aeroplanes with extended wing ti p , as applicable to aeroplane configuration.

Effective Date: 25 November 2011EASA AD No.: 20 11

- 02 1 9

E ASA Form 110 Page 2 / 2 Required A ction(s) and Compliance Time(s) : Required as indicated , unless accomplished previously: (1) Within 24 months after the effective date of this AD, accomplish the follo wing actions, as applicable to aeroplane configuration: (1 .1 ) For aeroplanes with basic wing tip, replace the SWC P/N 0020AK

or P/N 0020AK1

, or P/N 0020AK2

, or P/N 0020AK4

, with a new SWC P/N 0020AK6

, in accordance with the instructions of SAAB SB 340

- 27

- 0 98

. ( 1. 2) For aeroplanes with extended wing tip

, r eplace the SWC P/N 0020AK3 MOD 1 with a new SWC P/N 0020AK7

, in accordance with the instructions of SAAB SB 340

- 27

- 099. (2) Concurrent Requirement : Prior to, or concurrent with, modification of an aeroplane as required by paragraph (1) of this AD, modify the aeroplane in accordance with the instructions of SAAB SB 340

- 27

- 097 (SAAB Mod.3311)

. ( 3 ) After modification of an aeroplane as required by paragraph (1 .1 ) or ( 1. 2) of this AD, as applicable, do not insta ll any SWC P/N 0020AK, or P/N 0020AK1, or P/N 0020AK2, or P/N 0020AK4, or P/N 0020AK3 MOD 1 on that aeroplane.

Ref. Public ations: SAAB SB 34 0

- 27

- 097 original issue dated 01 September 2011, or Revision 01 dated 26 September 2011 , or R evision 02 dated 07 Oc tober 2011

. SAAB SB 340

- 27

- 098 original issue dated 01 September 2011.

SAAB SB 340

- 27

- 09 9 original issue dated 0 1 September 2011.

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. This AD was posted on 10 October 2011 as PAD 11

- 106 for consultation until 07 November 2011. The Comment Response Document can be found at http://ad.easa.europa.eu/

. 3. Enquiries regarding this A D 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: Saab AB, Support and Services

, SE

- 581 88 Linköping, Sweden

, Fax: +46 13 184874

, E

- mail: saab340.techsupport@s aabgroup.com

.