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 April 2, 2010 (75 FR 16696). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:
During accomplishment of Damage Tolerant--Airworthiness Limitation Item task 712106-01-01 from A330 ALS Part 2, an A330 operator found a Fluorescent Penetrant Inspection (FPI) indication in the head of the shank filet radius in one of the Pratt & Whitney (PW) forward (FWD) engine mount pylon bolts.
Investigation has confirmed that this FPI indication was due to a quality manufacturing process issue which led to a bolt non- conformance and is also applicable to aftward (AFT) mount pylon bolts.
Dual-bolt fractures could lead to inability for mount assembly to sustain loads which may lead to an engine mount failure and consequently to engine separation from the aeroplane during flight, which would constitute an unsafe condition.
This AD requires a one time detailed visual inspection of the FWD and AFT mount pylon bolts on all A330 aeroplanes fitted with PW engines (8 bolts per engine) and replacement of any affected bolt.
You may obtain further information by examining the MCAI in the AD docket.
Comments
We gave the public the opportunity to participate in developing this AD. We considered the comments received.
Requests To Refer to the Latest Pratt & Whitney Service Information
Delta Airlines and Pratt & Whitney--Cheshire Engine Center request that we revise the NPRM to refer to Pratt & Whitney Service Bulletin PW4G-100-71-35, Revision 1, dated December 4, 2009, for determining suspect bolts, rather than Pratt & Whitney Service Bulletin PW4G-100- 71-35, dated March 14, 2008, which was referenced in the NPRM as the appropriate source for determining suspect bolts. The commenters statethat Pratt & Whitney Service Bulletin PW4G-100-71-35, Revision 1, dated December 4, 2009, corrected suspect bolt serial numbers, and the serial number range of suspect bolts was reduced.
We agree with the requests. Since fewer parts are listed and no parts are added in Pratt & Whitney Service Bulletin PW4G-100-71-35, Revision 1, dated December 4, 2009, we have revised paragraph (h) of this AD to refer to Pratt & Whitney Service Bulletin PW4G-100-71-35, Revision 1, dated December 4, 2009, as the appropriate source for determining suspect bolts. We have also revised paragraph (h) of this AD to provide credit to operators that used Pratt & Whitney Service Bulletin PW4G-100-71-35, dated March 14, 2008, to determine suspect bolts before the effective date of this AD.
Conclusion
We 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 determined that these changes 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 41 products of U.S. registry. We also estimate that it will take about 7 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Required parts will cost about $16,672 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 $707,947, or $17,267 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: