Discussion
The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0020, dated January 31, 2019 (``EASA AD 2019-0020'') (also referred to as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for all Airbus SAS Model A350-941 and -1041 airplanes.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus SAS Model A350-941 and -1041 airplanes. The NPRM published in the Federal Register on April 9, 2019 (84 FR 14038). The NPRM was prompted by reports of cracks within the ring gears of an SGRA resulting from a change in the raw material manufacturing process. The NPRM proposed to require replacement of affected parts with serviceable parts.
The FAA is issuing this AD to address cracking of SGRA ring gears. This condition, if not detected and corrected, could, in combination withan independent failure on the second SGRA of the same slat surface, lead to detachment of the slat surface, possibly resulting in reduced control of the airplane and injury to persons on the ground. See the MCAI for additional background information.
Comments
The FAA gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment.
Support for the NPRM
The Air Line Pilots Association, International; Stephanie Lok; and an anonymous commenter indicated their support for the NPRM.
Request To Clarify Requirements for Group 1 Airplanes
Delta Air Lines (Delta) requested that a statement be added to paragraph (g) of this AD to clarify that the installation of affected parts was prohibited for Group 1 airplanes before 15,000 flight hours. Delta asserted that the AD could be interpreted as allowing the installation of affected parts on those airplanes during that time period.
The FAA does not agree that an additional statement to paragraph (g) of this AD is necessary. The FAA has confirmed with EASA that since the safety assessment was performed on the life of the airplane and not the life of the affected part, a restriction to limit the affected parts prior to 15,000 flight hours is not necessary. Therefore, the commenter's interpretation that installation of affected parts could be allowed prior to 15,000 flight hours is correct. This AD has not been changed in this regard.
Request To Modify Serial Number Table
Delta requested that the serial numbers of final assembly line units be removed from Table 1 of certain Liebherr service information instead of noting that they are to be excluded.
The FAA does not agree with the commenter's request. Although the proposal may provide a more straightforward presentation of the serial numbers, obtaining new service information with revised serial number tables from the manufacturer would delay publication of this AD. This delay would be inappropriate since the FAA has determined that an unsafe condition exists and that the required actions must be accomplished to ensure continued safety. The FAA also has determined that the serial number table in the Liebherr service information provides the information necessary to comply with this AD. Therefore, this AD has not been changed in this regard.
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Request To Clarify Location of Identification Mark
Delta requested that certain Airbus service information be updated to clarify the location of a certain marking on the identification plate. Delta noted that the Liebherr service information refers to the specified marking, but does not show the marking's location, while the Airbus service information does not refer to the marking at all.
The FAA disagrees with obtaining revised service information because it would delay publication of this AD, which would be inappropriate for the reasonsstated previously. However, the FAA agrees to clarify the location of the specified marking on the identification plate. The FAA has confirmed with EASA that the marking will be on both ``A'' faces of the identification plate, as depicted in Figure 1 of the Liebherr service information. This AD has not been changed in this regard.
Conclusion
The FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes:
Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.
Related IBR Material Under 1 CFR Part 51
EASA AD 2019-0020 describes procedures for replacing the affected SGRAs. This material is reasonably available because the interested partieshave access to it through their normal course of business or by the means identified in the ADDRESSES section.
Costs of Compliance
The FAA estimates that this AD affects 12 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions ----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- 25 work-hours x $85 per hour = $2,125........................ (*) $ * $2,125 * $25,500 ----------------------------------------------------------------------------------------------------------------
* The FAA has received no definitive data that would enable the agency to provide cost estimates for the partsspecified in this AD.
According to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. The FAA does not control warranty coverage for affected individuals. As a result, the FAA has included all known costs in the cost estimate.
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.
The FAA is 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.
This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes and associated appliances to the Director of the System Oversight Division.
Regulatory Findings
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) Will not affect intrastate aviation in Alaska, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.