AD 2013-07-10

This AD is effective May 20, 2013.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of May 20, 2013.

For service information identified in this AD, contact International Aero Engines, 628 Hebron Avenue, Suite 400, Glastonbury, CT 06033; phone: 860-368-3823; fax: 860-755-6876. You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781-238-7125.

Martin Adler, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7157; fax: 781-238-7199; email: martin.adler@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM published in the Federal Register on January 9, 2013 (78 FR 1776). That NPRM proposed to require the replacement of all No. 4 bearing internal scavenge tubes, P/N 2A2074-01. That NPRM also proposed to require checking the alignment of the No. 4 bearing external scavenge tube, P/N 6A5254, and if it fails the check, proposed to require replacement of the external scavenge tube.

We gave the public the opportunity to participate in developing this AD. The following presents the comment received on the proposal and the FAA's response to the comment.

The National Transportation Safety Board (NTSB) requested that the AD include a maximum number of allowable cycles for the No. 4 bearing internal scavenge tube. The NTSB is concerned that the proposed AD requirement to remove the internal scavenge tube at the next combustor module-level exposure has the potential to leave the tube installed indefinitely.

We do not agree. Required maintenance provides sufficient limitations on the maximum number of cycles that the No. 4 bearing internal scavenge tube can experience. We did not change the AD.

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD as proposed.

We estimate that this AD will affect 123 engines installed on airplanes of U.S. registry. We estimate that it will take 1.5 hours per engine to replace the No. 4 bearing internal scavenge tube, and 3 hours per engine to replace the No. 4 bearing external scavenge tube. Required parts will cost $25,251 per engine. The average labor rate is $85 per hour. Based on these figures, we estimate the cost of the AD on U.S. operators to be $3,152,921.

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 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 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.

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):