EASA AD No.: 2011-0219

EASA Form 110 Page 1/2

EASA AIRWORTHINESS DIRECTIVE

AD No.: 2011-0219

Date: 11 November 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 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].

Type Approval Holder’s Name :

SAAB AB, Aeronautics

Type/Model designation(s) :

SF340A and 340B aeroplanes

TCDS Number : EASA.A.068

Foreign AD : Not applicable

Supersedure : None

ATA 27 Flight Controls – Stall Warning/Identification System –

Replacement

Manufacturer(s): SAAB AB, Aeronautics (formerly SAAB Aerosystems).

Applicability: Model SF340A aeroplanes, serial numbers (s/n) 004 through 159 inclusive, 

and Model 340B aeroplanes, s/n 160 through 459 inclusive, except

aeroplanes that have SAAB 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, 379, 385, 395, 405, 409, 431 and 455.

Reason: A few natural stall events, specifically when operating in icing conditions, 

have 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,

which include instructions to replace the present Stall Warning Computer 

(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 selection 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 on aeroplanes 

with basic wing tip, and installing a new SWC P/N 0020AK7 on aeroplanes 

with extended wing tip, as applicable to aeroplane configuration.

Effective Date: 25 November 2011
EASA AD No.: 2011-0219

EASA Form 110 Page 2/2

Required Action(s) 

and Compliance

Time(s):

Required as indicated, unless accomplished previously:

(1) Within 24 months after the effective date of this AD, accomplish the 

following 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 340-27-098.

(1.2) For aeroplanes with extended wing tip, replace 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 install 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. Publications: SAAB SB 340-27-097 original issue dated 01 September 2011, or Revision 

01 dated 26 September 2011, or Revision 02 dated 07 October 2011.

SAAB SB 340-27-098 original issue dated 01 September 2011.

SAAB SB 340-27-099 original issue dated 01 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 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:

Saab AB, Support and Services, SE-581 88 Linköping, Sweden,

Fax: +46 13 184874, E-mail: saab340.techsupport@saabgroup.com.