The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to GE CF34-10E series turbofan engines. We published the proposed AD in the Federal Register on January 17, 2007 (72 FR 1946). That action proposed to require revising the combustor case published life limit and removing combustor cases from service before reaching a reduced life limit.
Examining the AD Docket
You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility 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.
Comments
We provided the public the opportunity to participate in the development of thisAD. We received no comments on the proposal or on the determination of the cost to the public.
Elimination of Paragraph (g)
After we issued the proposed AD, our review indicated that we should simplify the compliance by eliminating paragraph (g). That paragraph is redundant to paragraph (f), and would only add an additional requirement for the operators to show compliance after removal of every affected part. We eliminated the proposed AD paragraph (g), and re-codified the paragraphs, in this AD.
Conclusion
We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.
Costs of Compliance
We estimate that this AD will affect 42 CF34-10E series turbofan engines installed on airplanes of U.S. registry. This combustor case removal does not impose any additional labor costs if performed at the time of scheduled engine overhaul. The financial burden to the operators (prorate) is about $140,080 per engine due to the reduction in the life limit. Based on these figures, and on the prorating for the usage of the combustor cases, we estimate the cost of the AD on U.S. operators to be $5,886,720.
Authority for This Rulemaking
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.
Regulatory Findings
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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive: