AD 2013-02-06

This AD is effective February 12, 2013.

We must receive comments on this AD by March 14, 2013.

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: 202-493-2251.

• 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 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 received a report of an engine shutdown and turbine case burn-through, preceded by exceedance of the engine exhaust gas temperature (EGT) limit and loss of engine oil. Investigation revealed that the event was caused by damage to the HPT stage 2 nozzle due to inadequate part cooling. HPT stage 2 nozzles, part numbers (P/Ns) 2101M24G01, 2101M24G02, and 2101M24G03, are identified as having the inadequate cooling design. This condition, if not corrected, could result in HPT stage 2 nozzle failure, leading to uncontrolled fire, engine shutdown, and damage to the airplane.

We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

This AD requires initial and repetitive borescope inspections and removal from service before further flight if burn holes are detected, in HPT stage 2 nozzles, P/Ns 2101M24G01, 2101M24G02, and 2101M24G03. This AD also requires mandatory removal from service of these HPT stage 2 nozzles at the next engine shop visit.

No domestic operators use this product. Therefore, we find that notice and opportunity for prior public comment are unnecessary, and that good cause exists for making this amendment effective in less than 30 days.

This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include the Docket Number FAA-2012-1293 and Directorate Identifier 2012-NE-45-AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of 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 AD.

We estimate that this AD will affect no engines installed on airplanes of U.S. registry. We also estimate that it would take about two hours per engine to perform a borescope inspection of the HPT stage 2 nozzle. The average labor rate is $85 per work hour. Required parts would cost about $487,312 per engine. Based on these figures, we estimate the cost of this proposed AD to U.S. operators to be $0.

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):