AD 2005-25-12

Effective December 28, 2005. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of December 28, 2005.

We must receive any comments on this AD by February 13, 2006.

Use one of the following addresses to comment on this AD:

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.

• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.

• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.

• Fax: (202) 493-2251.

• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Turbomeca, 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 15, for the service information identified in this AD.

Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7175; fax (781) 238-7199.

The Direction Generale de L'Aviation Civile (DGAC), which is the airworthiness authority for France, notified us that an unsafe condition might exist on Turbomeca Astazou XIV B and XIV H turboshaft engines that have operated with an air intake noise suppressor. The DGAC advises that several cases of failure of 2nd stage axial compressor wheel blades have occurred in service. An investigation revealed that these failures result from aerodynamic-induced stresses caused by improperly installed air intake noise suppressors. An improperly installed air intake noise suppressor has too great an angular position on the air intake casing. This in turn results in downstream airflow turbulence causing high stresses in the 2nd stage axial compressor wheel blades.

We have reviewed and approved the technical contents of Turbomeca Alert Service Bulletin (ASB) No. A283 72 0800, dated February 5, 2004, that describes instructions for ultrasonic inspection of 2nd stage axial compressor wheel blades. The DGAC classified this alert service bulletin as mandatory and issued AD F-2004-029, dated February 18, 2004, in order to ensure the airworthiness of these Astazou XIV B and XIV H turboshaft engines in France.

These Astazou XIV B and XIV H turboshaft engines are manufactured in France and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Under this bilateral airworthiness agreement, the DGAC kept the FAA informed of the situation described above. We have examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

The unsafe condition described previously is likely to exist or develop on other Turbomeca Astazou XIV B and XIV H turboshaft engines of the same type design. We are issuing this AD to prevent failure of 2nd stage axial compressor wheel blades, leading to in-flight engine shutdown and autorotation landing. This AD requires:

• Before further flight, ensuring proper installation of air intake noise suppressors; and

• For engines operated with improperly installed air intake noise suppressors, removing the engine and performing an ultrasonic inspection of 2nd stage axial compressor wheel blades, within 50 flight hours or 6 months after the effective date of this AD, whichever occurs first, and replacing blades that fail inspection.

You must use the service information described previously to perform the removals, blade inspections, replacements, and installations required by this AD.

Since an unsafe condition exists that requires the immediate adoption of this AD, we have found that notice and opportunity for public comment before issuing this AD are impracticable, 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 us any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. FAA-2005-23004; Directorate Identifier 2005-NE-42-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of the DMS Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

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 have 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 the regulation:

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); and

3. 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 summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES.

Under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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