2012-15690. Airworthiness Directives; Saab AB, Saab Aerosystems Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Saab AB, Saab Aerosystems Model 340A (SAAB/SF340A) and SAAB 340B airplanes. 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. We are proposing this AD to prevent natural stall events when operating in icing conditions, which if not corrected may result in loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by August 13, 2012.

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: [phone].
• 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 AD, contact Saab AB, Saab Aerosystems, SE-581 88, Linköping, Sweden; telephone [phone]; fax [phone]; email [e-mail]; Internet http://www.saabgroup.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. 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;​; 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 this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) 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, Washington 98057-3356; telephone [phone]; fax [phone].

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-2012-0672; Directorate Identifier 2011-NM-261-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

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2011-0219, dated November 11, 2011 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. 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, 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 [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.

Required actions also include modifying the airplane for the replacement of the SWC. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Saab has issued the following service bulletins:

• SAAB Service Bulletin 340-27-097, Revision 03, dated April 19, 2012.
• SAAB Service Bulletin 340-27-098, Revision 01, dated April 13, 2012.
• SAAB Service Bulletin 340-27-099, Revision 01, dated April 13, 2012.

The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

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 the same type design.

Differences Between This AD and the MCAI or Service Information

EASA AD 2011-0219, dated November 11, 2011, prohibits installation of certain part numbers following the accomplishment of the replacement required by paragraph (g) of this AD. This AD prohibits installation of those part numbers as of the effective date of this AD.

Costs of Compliance

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

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

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

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

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

§ 39.13

[Amended]

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

Saab AB, Saab Aerosystems: Docket No. FAA-2012-0672; Directorate Identifier 2011-NM-261-AD.

(a) Comments Due Date

We must receive comments by August 13, 2012.

(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 number 2650 and/or 2859 installed.

(1) Model 340A (SAAB/SF340A) airplanes serial numbers 004 through 159 inclusive.

(2) Model SAAB 340B airplanes, serial numbers 160 through 459 inclusive.

Note 1 to paragraph (c) of this AD:

This AD does not apply to airplanes with serial number 170, 342, 362, 363, 367, 372, 379, 385, 395, 405, 409, 431, and 455.

(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 which were not accompanied with a prior stall warning. We are issuing this AD to prevent natural stall events when operating in icing conditions, which if not corrected may 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 tip: 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 tip: 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

As of the effective date 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 SAAB Service Bulletin 340-27-097, dated September 1, 2011; or SAAB Service Bulletin 340-27-097, Revision 01, dated September 26, 2011; or 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 [phone]; fax [phone]. Information may be emailed to: [e-mail]. 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) 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 EASA 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.

Issued in Renton, Washington, on June 21, 2012.

John P. Piccola,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.