80 FR 78699 - Airworthiness Directives; Saab AB, Saab Aeronautics (Formerly Known as Saab AB, Saab Aerosystems) Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 242 (December 17, 2015)

We propose to supersede Airworthiness Directive (AD) 2012-24- 06 for certain Saab AB, Saab Aeronautics (formerly known as Saab AB, Saab Aerosystems) Model 340A (SAAB/SF340A) and SAAB 340B airplanes. AD 2012-24-06 requires 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. Since we issued AD 2012-24-06, a determination was made that airplanes with certain modifications were excluded from the AD applicability and are affected by the identified unsafe condition and the SWC required by AD 2012-24-06 contained erroneous logic. This proposed AD would add airplanes to the applicability, and would add requirements to replace the existing SWCs with new, improved SWCs and modify the airplane for the new replacement of the SWC. We are proposing this AD to prevent natural stall events during operation in icing conditions, which could result in loss of control of the airplane.

[Federal Register Volume 80, Number 242 (Thursday, December 17, 2015)]
[Proposed Rules]
[Pages 78699-78701]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-30560]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-6544; Directorate Identifier 2014-NM-198-AD]
RIN 2120-AA64


Airworthiness Directives; Saab AB, Saab Aeronautics (Formerly 
Known as Saab AB, Saab Aerosystems) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to supersede Airworthiness Directive (AD) 2012-24-
06 for certain Saab AB, Saab Aeronautics (formerly known as Saab AB, 
Saab Aerosystems) Model 340A (SAAB/SF340A) and SAAB 340B airplanes. AD 
2012-24-06 requires 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. 
Since we issued AD 2012-24-06, a determination was made that airplanes 
with certain modifications were excluded from the AD applicability and 
are affected by the identified unsafe condition and the SWC required by 
AD 2012-24-06 contained erroneous logic. This proposed AD would add 
airplanes to the applicability, and would add requirements to replace 
the existing SWCs with new, improved SWCs and modify the airplane for 
the new replacement of the SWC. We are proposing this AD to prevent 
natural stall events during operation in icing conditions, which could 
result in loss of control of the airplane.

DATES: We must receive comments on this proposed AD by February 1, 
2016.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    For service information identified in this proposed rule, 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. 
You may view this referenced 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.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
6544; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this proposed AD, 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.

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

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2015-6544; 
Directorate Identifier 2014-NM-198-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On November 21, 2012, we issued AD 2012-24-06, Amendment 39-17276 
(77 FR 73279, December 10, 2012). AD 2012-24-06 applies to certain Saab 
AB, Saab Aerosystems Model 340A (SAAB/SF340A) and SAAB 340B airplanes. 
AD 2012-24-06 was prompted by reports of stall events during icing 
conditions where the natural stall warning (buffet) was not identified. 
AD 2012-24-06 requires 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. 
We issued AD 2012-24-06 to prevent natural stall events during 
operation in icing conditions, which, if not corrected, could result in 
loss of control of the airplane.
    Airplanes with certain modifications were excluded from the 
applicability of AD 2012-24-06, Amendment 39-17276 (77 FR 73279, 
December 10, 2012). Since we issued AD 2012-24-06, we have determined 
that those modifications for airplanes identified in the applicability 
of AD 2012-24-06 are now subject to the identified unsafe

[[Page 78700]]

condition. In addition, a new, improved SWC has been designed to 
replace the existing SWC, as well as the SWC required by AD 2012-24-06. 
The installation of the new SWC includes modifying the airplane.
    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Union, has issued EASA 
Airworthiness Directive 2014-0218, dated September 29, 2014 (referred 
to after this as the Mandatory Continuing Airworthiness Information, or 
``the MCAI''), to correct an unsafe condition for certain Saab AB, Saab 
Aeronautics Model 340A (SAAB/SF340A) and SAAB 340B airplanes. The 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, 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 [http://ad.easa.europa.eu/ad/2011-0219, which corresponds to FAA AD 2012-24-
06, Amendment 39-17276 (77 FR 73279, December 10, 2012)] to require 
installation of the improved SWC.
    After that [EASA] AD was issued, in-service experience with the 
improved stall warning system revealed cases of premature stall 
warning activation during the take-off 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 
[http://ad.easa.europa.eu/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, 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 [EASA] 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.

    You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
6544.

Related Service Information Under 1 CFR Part 51

    Saab AB, Saab Aeronautics has issued the following service 
information:
     Saab Service Bulletin 340-27-109, dated April 14, 2014.
     Saab Service Bulletin 340-27-116, dated October 18, 2013.
     Saab Service Bulletin 340-27-120, dated July 11, 2014.
     Saab Service Bulletin 340-27-121, dated July 11, 2014.
     Saab Service Bulletin 340-27-122, dated July 11, 2014.
    The service information describes procedures for deactivating the 
stall warning speed curves in the SWCs for certain airplanes; replacing 
the existing SWCs with new, improved SWCs, and modifying the airplane 
for the new replacement of the SWC. This service information is 
reasonably available because the interested parties have access to it 
through their normal course of business or by the means identified in 
the ADDRESSES section.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of these 
same type designs.

Differences Between This Proposed AD and the MCAI or Service 
Information

    The applicability in the MCAI excludes airplanes which have been 
modified by Saab AB mod No. 2650 or mod No. 2859; however, this 
proposed AD does not exclude those airplanes because this proposed AD 
requires corrective actions for U.S. N-registered airplanes that have 
either modification installed.
    Paragraph (2) of the MCAI requires replacement of the existing SWCs 
within 18 months after the effective date of the MCAI. However, due to 
the urgency of the identified unsafe condition, we have determined that 
this replacement must be done within 12 months after the effective date 
of this AD, as specified in paragraph (h) of this proposed AD.
    These differences have been coordinated with the EASA and Saab AB, 
Saab Aeronautics.

Costs of Compliance

    We estimate that this proposed AD will affect 105 airplanes of U.S. 
registry.
    We also estimate that it would take about 78 work-hours per product 
to comply with the actions required by this proposed AD. The average 
labor rate is $85 per work-hour. Required parts would cost about 
$33,000 per product. Based on these figures, we estimate the cost of 
this proposed AD on U.S. operators to be $4,161,150, 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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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

[[Page 78701]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    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.

List of Subjects in 14 CFR Part 39

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

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 removing Airworthiness (AD) 2012-24-
06, Amendment 39-17276 (77 FR 73279, December 10, 2012), and adding the 
following new AD:

Saab AB, Saab Aeronautics: Docket No. FAA-2015-6544; Directorate 
Identifier 2014-NM-198-AD.

(a) Comments Due Date

    We must receive comments by February 1, 2016.

(b) Affected ADs

    This AD replaces AD 2012-24-06, Amendment 39-17276 (77 FR 73279, 
December 10, 2012).

(c) Applicability

    This AD applies to Saab AB, Saab Aeronautics (formerly known as 
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.
    (1) Model 340A (SAAB/SF340A) airplanes, serial numbers 004 
through 159 inclusive.
    (2) Model SAAB 340B airplanes, serial numbers 160 through 459 
inclusive, except serial numbers 170, 342, 362, 363, 367, 372, 379, 
385, 395, 405, 409, 431, 441, and 455.

(d) Subject

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

(e) Reason

    This AD was prompted by a determination that airplanes with 
certain modifications were excluded from AD 2012-24-06, Amendment 
39-17276 (77 FR 73279, December 10, 2012), and are affected by the 
identified unsafe condition and the stall warning computer (SWC) 
required by AD 2012-24-06 contained erroneous logic. We are issuing 
this AD to prevent natural stall events during operation in icing 
conditions, which could result in loss of control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Deactivation of Stall Speed Curves

    For airplanes identified in paragraphs (g)(1) and (g)(2) of this 
AD: Within 30 days after the effective date of this AD, do the 
deactivation specified in paragraph (g)(1) or (g)(2) of this AD, as 
applicable to airplane configuration, in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-27-116, 
dated October 18, 2013.
    (1) For airplanes with a basic wing tip that has been modified 
in accordance with Saab Service Bulletin 340-27-098: Deactivate the 
stall speed curves in the SWC having part number (P/N) 0020AK6.
    (2) For airplanes with an extended wing tip that has been 
modified in accordance with Saab Service Bulletin 340-27-099: 
Deactivate the stall speed curves in the SWC having part number (P/
N) 0020AK7.

(h) Replacement of SWCs

    Within 12 months after the effective date of this AD: Do the 
replacement specified in paragraph (h)(1) or (h)(2) of this AD, as 
applicable.
    (1) For airplanes with basic wing tips: Replace all SWCs with 
new, improved SWCs having P/N 0020AK6-1, in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-27-121, 
dated July 11, 2014.
    (2) For airplanes with extended wing tips: Replace all SWCs with 
new, improved SWCs having P/N 0020AK7-1, in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-27-122, 
dated July 11, 2014.

(i) Concurrent Modification

    Before or concurrently with the accomplishment of the applicable 
requirements of paragraph (h) of this AD, do the actions specified 
in paragraph (i)(1) or (i)(2) of this AD, as applicable to airplane 
configuration.
    (1) For airplanes on which either Saab AB mod No. 2650 or mod 
No. 2859 is not installed: Modify the stall warning and 
identification system, in accordance with the Accomplishment 
Instructions of Saab Service Bulletin 340-27-120, dated July 11, 
2014.
    (2) For airplanes on which either Saab AB mod No. 2650 or mod 
No. 2859 is installed, or on which both mods are installed: Modify 
the stall warning and identification system, in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-27-109, 
dated April 14, 2014.

(j) Parts Installation Prohibitions

    After doing the replacement required by paragraph (h) of this 
AD, no person may install any SWC having P/N 0020AK, 0020AK1, 
0020AK2, 0020AK4, 0020AK6, 0020AK7, or 0020AK3 MOD 1, on any 
airplane.

(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, 
WA 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/certificate holding district office. The 
AMOC approval letter must specifically reference this AD.
    (2) Contacting the Manufacturer: For any requirement in this AD 
to obtain corrective actions from a manufacturer, the action must be 
accomplished using a method approved by the Manager, International 
Branch, ANM-116, Transport Airplane Directorate, FAA; or the 
European Aviation Safety Agency (EASA); or Saab AB, Saab 
Aeronautics' EASA Design Organization Approval (DOA). If approved by 
the DOA, the approval must include the DOA-authorized signature.

Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) EASA Airworthiness Directive 2014-0218, dated September 29, 
2014, for related information. This MCAI may be found in the AD 
docket on the Internet at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2015-6544.
    (2) 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. You may view this 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.


    Issued in Renton, Washington, on November 23, 2015.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 2015-30560 Filed 12-16-15; 8:45 am]
 BILLING CODE 4910-13-P