AD 2017-22-09

This AD is effective December 11, 2017.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of December 11, 2017.

For service information identified in this final rule, contact Saab AB, Saab Aeronautics, SE-581 88, Linköping, Sweden; telephone +46 13 18 5591; fax +46 13 18 4874; email saab340techsupport@saabgroup.com; Internet http://www.saabgroup.com. You may view this referenced service information at the FAA, Transport Standards Branch, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0777.

Shahram Daneshmandi, Aerospace Engineer, International Section, Transport Standards Branch, FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356; telephone 425-227-1112; fax 425-227-1149.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Saab AB, Saab Aeronautics Model SAAB 340B airplanes. The NPRM published in the Federal Register on August 15, 2017 (82 FR 38621) (“the NPRM”).

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2017-0067, dated April 24, 2017 (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 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 various Service Bulletins (SB) providing instructions to replace the 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.

Consequently, EASA issued AD 2014-0218 [which corresponds to FAA AD 2016-22-15, Amendment 39-18704 (81 FR 76843, November 4, 2016)] to require installation and activation of the improved SWC. That [EASA] AD excluded certain SAAB 340B aeroplanes by s/n [serial number].

Since EASA AD 2014-0218 was issued, SAAB developed a technical solution applicable for some of those previously excluded aeroplanes, and issued SB 340-27-117 and SB 340-27-118, providing instructions to modify and activate the new SWC.

For the reasons described above, this [EASA] AD requires installation and activation of the improved SWC.

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-2017-0777.

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

We reviewed the relevant data and determined that air safety and the public interest require adopting this AD as proposed except for minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

Saab AB, Saab Aeronautics has issued Service Bulletin 340-27-117, dated January 23, 2017. This service information describes procedures for modifying the stall warning system.

Saab AB, Saab Aeronautics has also issued Service Bulletin 340-27-118, dated January 23, 2017. This service information describes procedures for installing new stall warning computers and activating the modified stall warning system.

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.

We estimate that this AD affects 4 airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

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.

This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes to the Director of the System Oversight Division.

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.

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

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

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):