Discussion \n\n\n\tThe EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0122, dated June 4, 2019 (''EASA AD 2019-0122'') (also referred to as the Mandatory Continuing Airworthiness Information, or ''the MCAI''), to correct an unsafe condition for certain Airbus SAS Model A318 airplanes; Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; A320-211, -212, -214, -216, -231, -232, and -233 airplanes; and Model A321-111, -112, - 131, -211, -212, -213, -231, and -232 airplanes. Model A320-215 airplanes are not certified by the FAA and are not included on the U.S. type certificate data sheet; this AD therefore does not include those airplanes in the applicability. \n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2014-24-07, Amendment 39-18040 (79 FR 72124, December 5, 2014) (''AD 2014-24-07''). AD 2014-24-07 applied to certain Airbus SAS Model A318 series airplanes; Model A319-111, -112, - 113, -114, -115, -131, -132, and -133 airplanes; A320-211, -212, -214, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211, - 212, -213, -231, -232 airplanes. The NPRM published in the Federal Register on September 6, 2019 (84 FR 46900). The NPRM was prompted by a report of a crack found in the side box beam flange of the fuselage at the FR 43 level during a fatigue test campaign. The NPRM proposed to continue to require repetitive rototest inspections for cracking; corrective actions if necessary; and modification of the torsion box, which would terminate the repetitive inspections. The NPRM also proposed to require certain revised compliance times. The FAA is issuing this AD to address cracking in the side box beam flange of the fuselage, which could affect the structural integrity of the airplane. \n\nComments \n\n\n\tThe 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. \n\nSupport for the NPRM \n\n\n\tUnited Airlines stated its support for the NPRM. \n\nRequest To Use a Certain Revision of the Service Information \n\n\n\tJetBlue requested that Airbus Service Bulletin A320-53-1251, Revision 03, dated September 19, 2016, and not Airbus Service Bulletin A320-53-1251, Revision 04, dated May 17, 2019, be used for accomplishing the actions specified in the proposed AD and paragraphs (2) and (3) of EASA AD 2019-0122. JetBlue stated that Airbus Service Bulletin A320-53-1251, Revision 04, dated May 17, 2019, does not require any additional work compared to Airbus Service Bulletin A320- 53-1251, Revision 03, dated September 19, 2016. \n\tThe FAA disagrees with the commenter's request. Paragraph (2) of EASA AD 2019-0122 specifically requires compliance in accordance with Airbus Service Bulletin A320-53-1251, Revision 04, dated May 17, 2019, due to changes highlighted in the Accomplishment Instructions for certain configurations. However, paragraph (5) of EASA AD 2019-0122 provides credit for Airbus Service Bulletin A320-53-1251, dated November 16, 2012; Airbus Service Bulletin A320-53-1251, Revision 01, dated October 18, 2013; Airbus Service Bulletin A320-53-1251, Revision 02, dated February 11, 2016; and Airbus Service Bulletin A320-53-1251, Revision 03, dated September 19, 2016; if the actions are accomplished before the effective date of the AD. This AD provides the same allowance for credit since EASA AD 2019-0122 is incorporated by reference. This AD has not been changed in this regard. \n\nRequest To Clarify the Applicability \n\n\n\tDelta Airlines (DAL) requested that certain language be added to the applicability paragraph of the proposed AD. DAL stated that paragraph (c) of the proposed AD applies to certain Model A310, A320, and A321 family airplanes as identified in EASA AD 2019-0122. DAL stated that EASA AD 2019-0122 provides additional applicability details, namely exclusions of manufacturer serial numbers based upon a certain Airbus modification embodied in production. DAL suggested that similar language be added to paragraph (c) of the proposed AD. \n\tThe FAA agrees to clarify the applicability of this AD. By incorporation by reference of EASA AD 2019-0122 into this AD, the same production modification applicability exceptions identified in EASA AD 2019-0122 apply to this AD. These exceptions are addressed by the statement ''. . . as identified in European Aviation Safety Agency (EASA) AD 2019-0122'' in paragraph (c) of this AD. We have not changed this AD in this regard. \n\tIn addition, this AD and EASA AD 2019-0122 are not applicable to Model A310 airplanes as the commenter stated. This AD has not been changed in this regard. \n\nConclusion \n\n\n\tThe 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: \n\tAre consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\nRelated IBR Material Under 1 CFR Part 51 \n\n\n\tEASA AD 2019-0122 describes procedures for repetitive rototest inspections for cracking; corrective actions if necessary; and modification of the torsion box, which terminates the repetitive inspections. This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 851 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: \n\n((Page 8385)) \n\n\n\n\n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Retained actions from AD 2014-24-07... 178 work-hours x $85 per $31,334 $46,464 $39,540,864 \n\thour = $15,130. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tThe new requirements of this AD add no new economic burden. \n\tThe FAA has received no definitive data that would enable the agency to provide cost estimates for the on-condition actions specified in this AD. \n\nAuthority for This Rulemaking \n\n\n\tTitle 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. \n\tThe 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. \n\nRegulatory Findings \n\n\n\tThis 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Will not affect intrastate aviation in Alaska, and \n\t(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. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.