AD 2015-20-06

This AD becomes effective November 10, 2015.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of November 10, 2015.

You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2015-0684 or in person at the Docket Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC.

For service information identified in this AD, contact Viking Air Limited, 9574 Hampden Road, Sidney, British Columbia V8L 8V5, Canada; telephone 250-656-7227; fax 250-656-0673; email technical.publications@vikingair.com; Internet http://www.vikingair.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. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-0684.

Aziz Ahmed, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228 7329; fax 516-794 5531.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Viking Air Limited (Type Certificate Previously Held by Bombardier, Inc.) Model DHC-7-1 and DHC-7-100 airplanes. The NPRM published in the Federal Register on April 13, 2015 (80 FR 19572).

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF-2014-34, dated October 2, 2014, dated (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for all Viking Air Limited (Type Certificate Previously Held by Bombardier, Inc.) Model DHC-7-1 and DHC-7-100 airplanes. The MCAI states:

Longitudinal cracks were discovered in the outboard nacelles upper longeron channels and angles at station XN1 78. The cracks were partially hidden by bearing blocks, Part Number (P/N) 75420978, at the nacelle latch locations. Undetected, these cracks may lead to the loss of stiffness in the forward engine mount; which may lead to a catastrophic failure.

Required actions include a one-time detailed visual inspection for cracking of the outboard nacelles upper longeron channels and angles. Corrective actions include repair, if necessary. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2015-0684-0002.

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (80 FR 19572, April 13, 2015) 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 (80 FR 19572, April 13, 2015) for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM (80 FR 19572, April 13, 2015).

Viking Air Limited has issued Service Bulletin V7-54-02, Revision NC, dated December 14, 2012. The service information describes procedures for an inspection for cracks in the outboard nacelles upper longeron channels and angles; and repair if necessary. 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 of this AD.

We estimate that this AD affects 10 airplanes of U.S. registry.

We also estimate that it will take about 3 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD on U.S. operators to be $2,550, or $255 per product.

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in 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.

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.

You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2015-0684; 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 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.

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):