Airworthiness Directives; Saab AB, Saab Aerosystems Airplanes

[Federal Register Volume 77, Number 237 (Monday, December 10, 2012)]
[Rules and Regulations]
[Pages 73279-73282]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-29169]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0672; Directorate Identifier 2011-NM-261-AD; 
Amendment 39-17276; AD 2012-24-06]
RIN 2120-AA64


Airworthiness Directives; Saab AB, Saab Aerosystems Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Saab AB, Saab Aerosystems Model 340A (SAAB/SF340A) and SAAB 340B 
airplanes. This AD was prompted by reports of stall events during icing 
conditions where the natural stall warning (buffet) was not identified. 
This AD requires replacing the stall warning computer (SWC) with a new 
SWC, which provides an artificial stall

[[Page 73280]]

warning in icing conditions, and modifying the airplane for the 
replacement of the SWC. We are issuing this AD to prevent natural stall 
events when operating in icing conditions, which, if not corrected, 
could result in loss of control of the airplane.

DATES: This AD becomes effective January 14, 2013.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of January 14, 
2013.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Shahram Daneshmandi, Aerospace 
Engineer, International Branch, ANM-116, Transport Airplane 
Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; 
telephone (425) 227-1112; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on June 27, 2012 (77 FR 
38224). That NPRM proposed to correct an unsafe condition for the 
specified products. The Mandatory Continuing Airworthiness Information 
(MCAI) states:

    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 [European Aviation Safety 
Agency (EASA)] 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.

You may obtain further information by examining the MCAI in the AD 
docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received. The National 
Transportation Safety Board stated that it supports the NPRM (77 FR 
38224, June 27, 2012).

Request To Revise Company Name and Email Address

    Saab AB (the commenter) requested that we revise the NPRM (77 FR 
38224, June 27, 2012) throughout to change the name of the Saab company 
referenced in the NPRM from ``Saab AB, Saab Aerosystems'' to the new 
company name, ``Saab AB, Aeronautics.'' The commenter also requested to 
change the company email address referenced in the NPRM from 
``[email protected]'' to 
``[email protected].''
    We agree with the intent of the commenter's request. The FAA is in 
the process of changing the type certificate data sheet (TCDS) to 
reflect the name change. We will use the name identified in the current 
TCDS so as not to delay issuance of the final rule. Once the TCDS has 
been changed, we will use the new name in subsequent ADs. We changed 
the email address appropriately in paragraph (m) of this AD.

Request To Revise Text in Summary Section and Paragraph (e) of the NPRM 
(77 FR 38224, June 27, 2012)

    Saab AB requested that we revise the second and third sentences in 
the Summary section and a related sentence in paragraph (e) of the NPRM 
(77 FR 38224, June 27, 2012). In the Summary section, the commenter 
requested that we revise the following text to clarify that the 
airplane had been certified with natural buffet--as the stall warning--
in icing conditions, and explained that replacement of the SWC would 
increase the safety level by introducing an artificial stall warning 
for icing conditions.

    This proposed AD was prompted by reports of stall events during 
icing conditions which were not accompanied with a prior stall 
warning. This proposed AD would require replacing the stall warning 
computer (SWC) with a new SWC, and modifying the airplane for the 
replacement of the SWC.

    The commenter suggested the following text.

    This proposed AD was prompted by reports of stall events during 
icing conditions where the natural stall warning (buffet) was not 
identified. This proposed AD would require replacing the stall 
warning computer (SWC) with a new SWC, which provides an artificial 
stall warning in icing conditions, and modifying the airplane for 
the replacement of the SWC.

    The commenter also requested that the first sentence in paragraph 
(e) of the NPRM (77 FR 38224, June 27, 2012) be changed to match the 
new wording.
    We agree with the request for the reasons provided by the 
commenter. Therefore, we changed the wording in the Summary section and 
paragraph (e) of this AD as proposed by the commenter.

Request To Revise Text in Paragraph (i) of the NPRM (77 FR 38224, June 
27, 2012)

    Saab AB requested that we revise paragraph (i) of the NPRM (77 FR 
38224, June 27, 2012), which reads ``As of effective date of this AD, 
do not install any SWC having P/N 0020AK, 0020AK1, 0020AK2, 0020AK4, or 
0020AK3 MOD 1 on any airplane,'' to ``After modification of an airplane 
as required by paragraph (g) and (h) of this AD, do not install any SWC 
having P/N 0020AK, 0020AK1, 0020AK2, 0020AK4, or 0020AK3 MOD 1 on any 
airplane.'' The commenter stated that this change would allow an 
operator, during the compliance time, to install an SWC having the same 
part number of the failed SWC.
    We agree because there is a potential problem with availability of 
the new part. Therefore, we have changed the wording in paragraph (i) 
of this AD to match the intent of the commenter's request.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously--except for minor 
editorial changes. We have determined that these changes:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM (77 FR 38224, June 27, 2012) for correcting the unsafe condition; 
and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM (77 FR 38224, June 27, 2012).

Costs of Compliance

    We estimate that this AD will affect 162 products of U.S. registry. 
We also estimate that it will take about 78 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $85 per work-hour. Required parts will cost about $33,000 per 
product. Where the service information lists required parts costs that 
are covered under warranty, we

[[Page 73281]]

have assumed that there will be no charge for these parts. As we do not 
control warranty coverage for affected parties, some parties may incur 
costs higher than estimated here. Based on these figures, we estimate 
the cost of this AD to the U.S. operators to be $6,420,060, or $39,630 
per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD will not have a substantial direct 
effect on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979);
    3. Will not affect intrastate aviation in Alaska; and
    4. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the NPRM (77 FR 38224, June 27, 2012), 
the regulatory evaluation, any comments received, and other 
information. The street address for the Docket Operations office 
(telephone (800) 647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2012-24-06 Saab AB, Saab Aerosystems: Amendment 39-17276. Docket No. 
FAA-2012-0672; Directorate Identifier 2011-NM-261-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective January 14, 
2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Saab AB, Saab Aerosystems Model 340A (SAAB/
SF340A) and SAAB 340B airplanes, certificated in any category, as 
identified in paragraphs (c)(1) and (c)(2) of this AD, except 
airplanes that have SAAB Modification 2650 and/or 2859 installed. 
This AD does not apply to airplanes with serial numbers 170, 342, 
362, 363, 367, 372, 379, 385, 395, 405, 409, 431, and 455.
    (1) Model 340A (SAAB/SF340A) airplanes, serial numbers 004 
through 159 inclusive.
    (2) Model SAAB 340B airplanes, serial numbers 160 through 459 
inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 27: Flight 
Controls.

(e) Reason

    This AD was prompted by reports of stall events during icing 
conditions where the natural stall warning (buffet) was not 
identified. We are issuing this AD to prevent natural stall events 
when operating in icing conditions, which, if not corrected, could 
result in loss of control of the airplane.

(f) Compliance

    You are responsible for having the actions required by this AD 
performed within the compliance times specified, unless the actions 
have already been done.

(g) Replacement

    (1) For airplanes with basic wing tips: Within 24 months after 
the effective date of this AD, replace all stall warning computers 
(SWCs) having part number (P/N) 0020AK, 0020AK1, 0020AK2, or 
0020AK4, with a new SWC P/N 0020AK6, in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-27-098, 
Revision 01, dated April 13, 2012.
    (2) For airplanes with extended wing tips: Within 24 months 
after the effective date of this AD, replace the SWC P/N 0020AK3 MOD 
1 with a new SWC P/N 0020AK7, in accordance with the Accomplishment 
Instructions of Saab Service Bulletin 340-27-099, Revision 01, dated 
April 13, 2012.

(h) Concurrent Modification

    Before or concurrently with the accomplishment of the 
requirements of paragraph (g) of this AD: Modify the airplane in 
accordance with the Accomplishment Instructions of Saab Service 
Bulletin 340-27-097, Revision 03, dated April 19, 2012.

(i) Parts Installation Prohibition

    After accomplishing the replacement required by paragraph (g) of 
this AD and the modification required by paragraph (h) of this AD, 
do not install any SWC having P/N 0020AK, 0020AK1, 0020AK2, 0020AK4, 
or 0020AK3 MOD 1 on any airplane.

(j) Credit for Previous Actions

    This paragraph provides credit for actions required by paragraph 
(h) of this AD, if those actions were performed before the effective 
date of this AD using the service bulletin specified in paragraph 
(j)(1), (j)(2), or (j)(3) of this AD, which are not incorporated by 
reference in this AD.
    (1) Saab Service Bulletin 340-27-097, dated September 1, 2011.
    (2) Saab Service Bulletin 340-27-097, Revision 01, dated 
September 26, 2011.
    (3) Saab Service Bulletin 340-27-097, Revision 02, dated October 
7, 2011.

(k) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, ANM-
116, International Branch, Transport Airplane Directorate, FAA, has 
the authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the International Branch, send it to ATTN: Shahram 
Daneshmandi, Aerospace Engineer, International Branch, ANM-116, 
Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone (425) 227-1112; fax (425) 227-1149. 
Information may be emailed to: [email protected]. 
Before using any approved AMOC, notify your appropriate principal 
inspector, or lacking a principal inspector, the manager of the 
local flight standards district office/

[[Page 73282]]

certificate holding district office. The AMOC approval letter must 
specifically reference this AD.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.

(l) Related Information

    Refer to MCAI European Aviation Safety Agency Airworthiness 
Directive 2011-0219, dated November 11, 2011, and the service 
information specified in paragraphs (l)(1) through (l)(3) of this 
AD, for related information.
    (1) Saab Service Bulletin 340-27-097, Revision 03, dated April 
19, 2012.
    (2) Saab Service Bulletin 340-27-098, Revision 01, dated April 
13, 2012.
    (3) Saab Service Bulletin 340-27-099, Revision 01, dated April 
13, 2012.

(m) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Saab Service Bulletin 340-27-097, Revision 03, dated April 
19, 2012.
    (ii) Saab Service Bulletin 340-27-098, Revision 01, dated April 
13, 2012.
    (iii) Saab Service Bulletin 340-27-099, Revision 01, dated April 
13, 2012.
    (3) For service information identified in this AD, contact Saab 
AB, Saab Aeronautics, SE-581 88, Link[ouml]ping, Sweden; telephone 
+46 13 18 5591; fax +46 13 18 4874; email 
[email protected]; Internet http://www.saabgroup.com.
    (4) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. 
For information on the availability of this material at the FAA, 
call 425-227-1221.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on November 21, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-29169 Filed 12-7-12; 8:45 am]
BILLING CODE 4910-13-P

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T02:58:14.402768+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

40ff15fa4e45d2446475e6c8e47855492624c480934f9b1bab1f08d77fa7bf8e

Text SHA-256

d0a7a9cfcb779292a87b556f5aee51ee67a8e07fd34d17d80fd8c26c9118f878