Background \n\n\n\tOn March 18, 2020, an Airbus Model A321-231 airplane, powered by IAE V2533-A5 model turbofan engines, experienced an uncontained HPT 1st-stage disk failure that resulted in high-energy debris penetrating the engine cowling. Based on a preliminary analysis of this event, on March 21, 2020, the FAA issued Emergency AD 2020-07-51, which requires the removal from service of certain HPT 1st-stage disks installed on IAE V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, and V2533-A5 model turbofan engines. \n\tSince the FAA issued AD 2020-07-51, the manufacturer conducted a root cause analysis and identified a different population of HPT 1st- stage and HPT 2nd-stage disks that are affected by the unsafe condition and require removal from service. This condition, if not addressed, could result in failure of the HPT, uncontained HPT failure, damage to the engine, damage to the airplane, and loss of the airplane. TheFAA is issuing this AD to address the unsafe condition on these products. \n\nFAA's Determination \n\n\n\tThe FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. \n\nAD Requirements \n\n\n\tThis AD requires the removal from service of certain HPT 1st-stage and HPT 2nd-stage disks installed on IAE V2500-A1, V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, V2531-E5, and V2533-A5 model turbofan engines. \n\nInterim Action \n\n\n\tThe design approval holder is currently developing a modification to address the unsafe condition identified in this AD. Once this modification is developed, the FAA might consider additional rulemaking. \n\nJustification for Immediate Adoption and Determination of the Effective Date \n\n\n\tSection 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq.) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for ''good cause,'' finds that those procedures are ''impracticable, unnecessary, or contrary to the public interest.'' Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause. \n\tAn unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies foregoing notice and comment prior to adoption of this rule. On March 18, 2020, an Airbus Model A321-231 airplane, powered by IAE V2533-A5 model turbofan engines, experienced an uncontained HPT 1st- stage disk failure that resulted in an aborted takeoff. The uncontained failure of the HPT 1st-stage disk resulted in high-energy debrispenetrating the engine cowling. The FAA published Emergency AD (EAD) 2020-07-51 on March 21, 2020 (followed by publication in the Federal Register on April 13, 2020, as a Final Rule, Request for Comments (85 FR 20402)), to remove from service HPT 1st-stage disks identified as having the highest risk of failure. Based on the root cause analysis performed since that event, the manufacturer has identified a different population of affected HPT 1st-stage and HPT 2nd-stage disks that are affected by the same unsafe condition and require removal from service. These HPT disks have the highest risk of failure and require removal within 50 flight cycles or 30 days after the effective date of this AD, whichever comes first, to prevent additional HPT disk failures and maintain an acceptable level of safety. This unsafe condition may result in loss of the airplane. \n\tThe FAA considers removal of certain HPT 1st-stage and HPT 2nd- stage disks to be an urgent safety issue. Accordingly, notice andopportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b)(3)(B). In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forego notice and comment. \n\nComments Invited \n\n\n\tThe FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under ADDRESSES. Include the docket number FAA-2020-1168 and Project Identifier AD-2020-01568-E at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this final rule because of those comments. \n\tExcept for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to https://www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule. \n\nConfidential Business Information \n\n\n\tCBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this AD contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this AD, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as ''PROPIN.'' The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this AD. Submissions containing CBI should be sent to Nicholas Paine, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. \n\nRegulatory Flexibility Act \n\n\n\tThe requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because FAA has determined that it has good cause to adopt this rule without prior notice and comment, RFA analysis is not required. \n\n((Page 460)) \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 4 engines installed on airplanes of U.S. registry. \n\tThe FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Remove HPT 1st-stage or HPT 2nd-stage 92 work-hours x $85 per $300,000 $307,820 $1,231,280 \n\tdisk from service. hour = $7,820. ---------------------------------------------------------------------------------------------------------------- \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, and \n\t(2) Will not affect intrastate aviation in Alaska. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.