Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on August 16, 2007 (72 FR 45963). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:
It has been found the development of cracks in the forward fuselage right hand (RH) side skin during full-scale fatigue tests. Those cracks may quickly reach their critical length, reducing the aircraft structural integrity, with possible rapid decompression of the aircraft.
The corrective action includes rework of the aircraft structure on the forward fuselage LH (left-hand) and RH sides. You may obtain further information by examining the MCAI in the AD docket.
Relevant Service Information
EMBRAER has issued Service Bulletin 145-53-0067, Revision 02, dated August 28, 2007. We referred to EMBRAER Service Bulletin 145-53-0067, Revision 01, dated February 27, 2007, as the appropriate source of service information for doing the actions specified in the NPRM. The procedures in Revision 02 of the service bulletin are essentially the same as those procedures in Revision 01. Revision 02 revises the illustrations and makes editorial changes. We have revised paragraph (f)(1) and Table 1 of this AD to also refer to Revision 02 of the service bulletin.
Comments
We gave the public the opportunity to participate in developing this AD. We considered the comment received.
Request To Extend Grace Period
American Eagle Airlines requests that we extend the grace period specified in the NPRM. The commenter states that the compliance time of "prior to the accumulation of 22,000 total flight cycles or within 6 months after the effective date of this AD, whichever is later'' would impose an excessive strain on the operator due to labor requirements and time out of service. The commenter notes that anumber of its aircraft are near the 22,000 total flight cycle threshold and suggests that we change the grace period to within 2,000 flight cycles after the effective date of this AD.
We do not agree with the commenter's request to extend the grace period. In developing an appropriate compliance time for this action, we considered the urgency associated with the subject unsafe condition, the availability of required parts, and the practical aspect of accomplishing the required modification within a period of time that corresponds to the normal scheduled maintenance for most affected operators. However, according to the provisions of paragraph (g) of the final rule, we may approve requests to adjust the compliance time if the request includes data that prove that the new compliance time would provide an acceptable level of safety. We have not changed this final rule in this regard.
Conclusion
We reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously. We determined that this change will not increase the economic burden on any operator or increase the scope of the AD.
Differences Between This AD and the MCAI or Service Information
We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.
We might also have required different actions in this AD from those in the MCAI in order to follow our FAA policies. Any such differences are highlighted in a Note within the AD.
Costs of Compliance
We estimate that this AD will affect 624 products of U.S. registry. We also estimate that it will takeabout 60 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. Required parts will cost about $1,210 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these parts. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $3,750,240, or $6,010 per product.
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 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 this AD:
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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
Examining the AD Docket
You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains the NPRM, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA 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 AD: