EASA AD No.: 2014-0218

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EASA AIRWORTHINESS DIRECTIVE 

AD No.: 2014-0218 

Date: 29 September 2014 

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 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]. 

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 dated 18 October 2013. 

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

Warning Computer – Modification / 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 

registered in Canada which have been modified in accordance with SAAB AB 

modification (mod.) No. 2650 and/or mod. No. 2859. 

Note: This AD does not apply to Model 340B aeroplanes with s/n 170, 342, 

362, 363, 367, 372, 379, 385, 395, 405, 409, 431, 441 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, SAAB developed a modified stall 

warning system, incorporating improved stall warning logic, and issued Service 

Bulletin (SB) 340-27-098 and SB 340-27-099, providing instructions to replace 

the Stall Warning Computer (SWC) with a new SWC, and 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 installation of the 

improved SWC. 

After that AD was issued, in-service experience with the improved stall warning 

system revealed cases of premature stall warning activation during the take-off 
EASA AD No.: 2014-0218

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phase. In numerous recorded cases, the onset of stall warning occurred without 

the 6 minute delay after weight off wheels. 

This condition, if not corrected, could lead to premature stick shaker activation 

and consequent increase in pilot workload during the take-off phase, possibly 

resulting in reduced control of the aeroplane. 

To correct this unsafe condition, EASA issued AD 2013-0254 retaining the 

requirements of EASA AD 2011-0219, which was superseded, to require 

deactivation of the ice speed curves in the improved 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 Warning System installation), 

SB 340-27-121 (activation of improved SWC for aeroplanes 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 modification 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 aeroplanes modified in 

accordance with SAAB AB mod. No. 2650 and/or mod. No. 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 the requirements of EASA AD 

2013-0254, which is superseded, and requires modification of the Stall Warning 

and Identification System and replacement of the SWC with an improved unit. 

Effective Date: 13 October 2014 

Required Action(s) 

and Compliance 

Time(s): 

Required as indicated, unless accomplished previously: 

Requirements retained from EASA AD 2013-0254: 

(1) Within 30 days after 25 October 2013 [the effective date of EASA AD 

2013-0254], accomplish the following actions, as applicable 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 have 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 this 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 of SAAB SB 

340-27-121, or 

(2.2) For aeroplanes with an extended wing tip, replace the SWC with 

SWC P/N 0020AK7-1 in accordance with the instructions of SAAB 

SB 340-27-122. 

(3) Prior to, or concurrent with, modification of an 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, SB 340-27-109, as 

applicable for aeroplane configuration. 

(4) After modification of an aeroplane as required by paragraph (2) of this AD, 
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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 issue dated 01 September 2011. 

SAAB SB 340-27-099 original issue dated 01 September 2011. 

SAAB SB 340-27-116 original issue dated 18 October 2013. 

SAAB SB 340-27-120 original issue dated 11 July 2014. 

SAAB SB 340-27-121 original issue dated 11 July 2014. 

SAAB SB 340-27-122 original issue dated 11 July 2014. 

SAAB SB 340-27-109 original issue dated 14 April 2014. 

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 21 July 2014 as PAD 14-118 for consultation until 

18 August 2014. 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 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.