AD 2013-26-09

This AD becomes effective February 14, 2014.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7779; fax: 781-238-7199; email: frederick.zink@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to the specified products. The NPRM was published in the Federal Register on August 6, 2013 (78 FR 47581). The NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

Some cracks have been reported on the second stage turbine disc of ASTAZOU XIV engines inducted into a Repair Centre. These cracks are located in the serrations of the disc. The results of the technical investigation concluded that the cracks were present on non-shot peened second stage turbine discs (discs on which AB 138 modification was not incorporated), and on second stage turbine discs that were shot peened during their service life (discs on which AB 138 modification was incorporated after initial service use without shot peening). Until now, no crack has been reported on second stage turbine discs shot peened since new, these discs accounting for more than half of all ASTAZOU XIV flight hours. It was not possible to clearly identify what caused the cracks.

This condition, if not corrected, could lead to some events of disc serrations rupture, possibly resulting in uncontained second stage turbine blade release with consequent damage to, and reduced control of, the helicopter.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2013-0575-0002.

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (78 FR 47581, August 6, 2013). However, we did make an editorial change to the preamble of this AD.

We reviewed the available data and determined that air safety and the public interest require adopting this AD with the changes described previously. We determined that these changes will not increase the economic burden on any operator or increase the scope of this AD.

We estimate that this AD will affect about 6 engines of U.S. registry. We also estimate that it will take about 5 hours per engine to comply with this AD. The average labor rate is $85 per hour. Required parts will cost about $6,560 per engine. Based on these figures, we estimate the cost of this AD on U.S. operators to be $41,910.

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 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 to the extent that it justifies making a regulatory distinction, 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.

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):