Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Airbus Model A310 series airplanes. That NPRM was published in the Federal Register on April 20, 2007 (72 FR 19826). That NPRM proposed to require revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate new limitations for fuel tank systems.
Actions since NPRM Was Issued
After we issued the NPRM, Airbus published the A310 Fuel Airworthiness Limitations, Document 95A.1930/05, Issue 2, dated May 11, 2007 (approved by the European Aviation Safety Agency (EASA) on July 6, 2007) (hereafter referred to as "Document 95A.1930/05''). In the NPRM, we referred to Issue 1 of Document 95A.1930/05, dated December 19, 2005, as the appropriate source of service information for accomplishing the actions proposed in the NPRM. The fuel airworthiness limitations specified in Issue2 of Document 95A.1930/05 are the same as those in Issue 1 of Document 95A.1930/05. Airbus has revised certain task titles in Section 1 of Issue 2 of Document 95A.1930/05 and has clarified the applicability and corrected certain airplane maintenance manual (AMM) references in Section 2 of the document. Therefore, we have revised this AD by referring to Issue 2 of Document 95A.1930/05 as the appropriate source of service information.
After we issued the NPRM, EASA issued airworthiness directive 2007- 0096 R1, dated May 2, 2007, to correct certain compliance times; our NPRM included the correct compliance times, which we explained as differences between the NPRM and EASA airworthiness directive 2006- 0202, dated July 11, 2006. The compliance times in this AD already correspond with the compliance times of EASA airworthiness directive 2007-0096 R1. Therefore, we have revised paragraph (k) of this AD to refer to EASA airworthiness directive 2007-0096 R1.
After we issued the NPRM, Airbus published Operator Information Telex (OIT) SE 999.0079/07, Revision 01, dated August 14, 2007, to identify the applicable sections of the Airbus A310 AMM necessary for accomplishing the tasks specified in Section 1 of Document 95A.1930/05. We have added a note to paragraph (f) of this AD to refer to that OIT.
Comments
We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.
Request To Revise "Relevant Service Information'' Section
Airbus requests that we revise the "Relevant Service Information'' section to state that "Section 1, `Maintenance/Inspection Tasks,' of Document 95A.1930/05 describes certain FAL inspections, which are periodic inspections of certain features for latent failures that could contribute to a fire.'' In the NPRM, we specified that the latent failures could contribute to an ignition source. As justification, Airbus states that not all three tasks identified in Section1 of Document 95A.1930/05 contribute to minimizing the risk of an ignition source: Only Task 3 minimizes the risk of an ignition source, while Tasks 1 and 2 minimize the occurrence of a combustible environment. We agree with Airbus's statements. However, we have not revised this AD in this regard since the "Relevant Service Information'' section is not retained in a final rule.
Request To Revise the Unsafe Condition
Airbus states that it does not agree that there is an unsafe condition on Model A310 series airplanes, prior to accomplishing the maintenance/inspection tasks in Section 1 of Document 95A.1930/05. Airbus agrees that performing these tasks contributes to minimizing the risk of either an ignition source (Task 3) or the occurrence of a combustible environment (Tasks 1 and 2). In regard to the critical design configuration control limitations (CDCCLs), Airbus states that no unsafe condition exists at delivery, and that no unsafe condition will develop provided that operators observe the CDCCLs after delivery. Airbus further states that the CDCCLs are introduced to reduce the risk that an operator may inadvertently alter the design or installation, thus introducing a less safe configuration.
We infer Airbus would like us to revise the unsafe condition in this AD to incorporate its comments. We do not agree to revise the unsafe condition of this AD. Fuel airworthiness limitations (FALs) are items arising from a systems safety analysis that have been shown to have failure modes associated with an unsafe condition, as defined in FAA Memorandum 2003-112-15, "SFAR 88--Mandatory Action Decision Criteria,'' dated February 25, 2003. These FALs are identified in failure conditions for which an unacceptable probability of ignition risk could exist if specific tasks or practices or both are not performed in accordance with a manufacturer's requirements. As Airbus notes, if an operator does not observe the CDCCLs after delivery, then an unsafe condition could occur. For this reason we must mandate Document 95A.1930/05 to ensure the CDCCLs are observed. We have not changed this AD in this regard.
Request To Clarify the Requirements of Paragraph (h)
Airbus requests that we revise paragraph (h) of the NPRM to state that operators are required to update their internal procedures and documentation to ensure appropriate management and control of the CDCCLs specified in Section 2 of Document 95A.1930/05. Airbus states that paragraph (h) of the NPRM is unclear about what an operator is expected to do with the CDCCLs. Airbus further states that paragraph (h) of the NPRM tells operators to add the CDCCLs to the ALS, but Airbus states that it has already done so. Airbus also states that the ALS is part of the type certification (TC) documentation and is not changed by operators.
Although we understand Airbus' concern and welcome any feedback that would improve the readability or usability of an AD, the suggested language is too vagueto be legally enforceable, so we cannot use it in this AD. We understand that Airbus has revised its airworthiness limitations document. However, according to 14 CFR 39.7, no person may operate a product unless the requirements of an applicable AD have been met. The burden is placed on the operator, not on the manufacturer, to ensure that the requirements of an AD are met. The requirement, as stated in the NPRM, is for the operator to revise its copy of the airworthiness limitations document. This ensures that each affected operator maintains a current copy of the required airworthiness limitations.
Concerning Airbus' statement that paragraph (h) of the NPRM does not clearly specify what an operator is expected to with the CDCCLs, we would like to clarify that paragraph (h) requires that affected operators revise their copies of the airworthiness limitations document to include the CDCCL requirements. This is the only requirement imposed under this AD for CDCCLs; once this revision has been accomplished, compliance with paragraph (h) of this AD has been completed. Subsequently, 14 CFR 91.403(c) requires an affected operator to comply with the revised Airworthiness Limitations document. Ensuring that one's maintenance program and the actions of its maintenance personnel are in accordance with the Airworthiness Limitations is required, but not by the AD. According to 14 CFR 91.403(c), no person may operate an aircraft for which airworthiness limitations have been issued unless those limitations have been complied with. Therefore, there is no need to further expand the requirements of the AD beyond that which was proposed because section 91.403(c) already imposes the appropriate required action after the airworthiness limitations are revised. We have not changed this AD in this regard.
Change to Paragraph (f)
We have also clarified the compliance time in paragraph (f) of this AD by adding the word "thereafter'' to more clearly state that * * * the repetitive inspections must be accomplished thereafter * * *''
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 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.
Costs of Compliance
This AD affects about 69 airplanes of U.S. registry. The required actions take about 2 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $11,040, or $160 per airplane.
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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.
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 Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):