The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to GE CF6-80C2 series turbofan engines. We published the proposed AD in the Federal Register on November 12, 2003 (68 FR 64001). That action proposed to require replacing certain HPT stage 1 disks at or before reaching a new reduced life cycle limit.
Comments
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 overall impact to him is minimal. The commenter does not request any changes to the proposal as written. The FAA agrees.
One commenter requests that the proposal be withdrawn. The commenter believes that an AD is not necessary because the lower life limit has already been published by the manufacturer in Chapter 5, Airworthiness Limitations, of the engine manual.
The FAA does not agree. Changes to life limits that appear only in a manual or type certificate data sheet, even if FAA-approved, are not enforceable for all operators. Life limit reductions from the original certified limits become enforceable for all operators only through the AD process (14 CFR part 39).
Conclusion
We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD as proposed.
Changes to 14 CFR Part 39--Effect on the AD
On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. That regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. The material previously was included in each individual AD. Since the material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
There are about 526 CF6-80C2A5F, CF6-80C2B5F, CF6-80C2B7F, and CF6- 80C2D1Fturbofan engines of the affected design in the worldwide fleet. We estimate that 208 engines installed on airplanes of U.S. registry would be affected by this AD. The action does not impose any additional labor costs. The prorated cost of a new HPT stage 1 disk is about $43,306 per engine. Based on these figures, and on the prorating for the usage of the HPT stage 1 disks, the cost of the AD on U.S. operators is estimated to be $9,007,648.
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 by sending a request to us at the address listed under ADDRESSES. Include "AD Docket No. 2003-NE-46-AD" in your request.
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.
39.13 [Amended]
2. The FAA amends 39.13 by adding the following new airworthiness directive (AD):