AD 2005-18-16

This AD becomes effective October 13, 2005.

You may examine the AD docket on the Internet at http://dms.dot.gov or in Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC.

Robert Grant, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7757; fax (781) 238-7199.

The FAA proposed to amend 14 CFR part 39 with a proposed airworthiness directive. The proposed AD applies to GE CF34-3A1 turbofan engines with certain HPT rotating components installed. We published the proposed AD in the Federal Register on August 16, 2004 (69 FR 50344). That action proposed a requirement for removal from service of certain HPT components prior to their exceeding designated life limits.

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Offices 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.

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

One commenter states that the AD should identify the specific engines to which it applies or identify the applicable engines by the maintenance manual used. We agree that applicability should be clarified. We have reworded the AD to indicate that it applies only to CF34-3A1 engines installed on Bombardier series Regional Jet Model CL-600-2B19 (Regional Jet Series 100 and 440) airplanes with one or more of certain HPT rotating components installed.

Another commenter states that a note should be added to the AD indicating that this AD does not apply to CF34-3A1 engines installed on Challenger aircraft. We agree. We have clarified this AD to indicate that it applies only to engines installed on Bombardier series Regional Jet Model CL-600-2B19 (Regional Jet Series 100 and 440) airplanes with one or more of certain HPT rotating components installed.

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

We estimate that this AD would affect eight CF34-3A1 turbofan engines installed on airplanes of U.S. registry. We estimate that no affected engine has a listed HPT rotating component near its original type design life limit. Therefore, we estimate that this AD will not result in any additional direct labor or part costs.

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 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); 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 at the address listed under ADDRESSES.

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration 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: