Background \n\n\n\tThe EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2020-0271, dated December 8, 2020 (EASA AD 2020-0271) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for Leonardo S.p.A. (formerly Finmeccanica S.p.A, AgustaWestland S.p.A., Agusta S.p.A.; and AgustaWestland Philadelphia Corporation, formerly Agusta Aerospace Corporation) Model AB139, AW139, and AW189 helicopters, all serial numbers. Although EASA AD 2020-0271 applies to Model AB139, AW139, and AW189 helicopters, all serial numbers, this AD applies to helicopters with an affected part installed instead. \n\tThis AD was prompted by a report of the in-flight failure of one of the three stainless steel external rings bonded to the main rotor swashplate boot installed on Model AB139 and AW139 helicopters. The broken ring, under the effects of the centrifugal force, was released from the main rotor swashplate boot and impacted one tail rotor blade, causing extensive damage. Investigation revealed that the failure of the external ring was caused by fatigue initiated by corrosion. A contributing factor to the external ring failure was disbonding at the four points where the affected ring was bonded to the main rotor swashplate boot. Leonardo S.p.a. Model AW189 helicopters have a similar design, therefore, this model may be subject to the same unsafe condition revealed on the Model AB139 and AW139 helicopters. Since EASA AD 2020-0271 was published, there have been two more reports of discrepant main rotor boots. \n\tThe FAA is issuing this AD to address corrosion, cracking, and damage to the adhesive (e.g., disbonding) of any stainless steel external ring bonded to the main rotor swashplate boot, which could result in release of a ring from the main rotor swashplate boot, resulting in damage to, and reduced control of, the helicopter. See the EASA AD for additional background information. \n\nRelated IBR Material Under 1 CFR Part 51 \n\n\n\tEASA AD 2020-0271 specifies procedures for repetitive detailed inspections (DET) of the affected external rings for corrosion (including superficial oxidation), and cracks, and, depending on findings, polishing corrosion, and replacing an affected external ring with a serviceable part. EASA AD 2020-0271 also requires repetitive inspections for damage of the adhesive (e.g., disbonding) between the bonding areas of the affected external rings and the main rotor swashplate boot and re-applying the adhesive if necessary. For certain helicopters, EASA AD 2020-0271 requires a one-time restoring of the adhesive between the bonding areas of the affected external rings and the main rotor swashplate boot. For all helicopters, EASA AD 2020-0271 allows, under certain conditions, (re)installation of an affected part on a helicopter. \n\tThis material is reasonably available because the interested parties have accessto it through their normal course of business or by the means identified in the ADDRESSES section. \n\nFAA's Determination \n\n\n\tThese products have been approved by the aviation authority of another country, and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the State of Design Authority, the FAA has been notified of the unsafe condition described in the MCAI referenced above. The FAA is issuing this AD after evaluating all pertinent information and determining that the unsafe condition exists and is likely to exist or develop on other products of these same type designs. \n\nRequirements of This AD \n\n\n\tThis AD requires accomplishing the actions specified in EASA AD 2020-0271, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this AD. \n\nExplanation of Required Compliance Information \n\n\n\tIn the FAA's ongoing efforts to improve the efficiency of theAD process, the FAA initially worked with Airbus and EASA to develop a process to use certain EASA ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has since coordinated with other manufacturers and civil aviation authorities (CAAs) to use this process. As a result, EASA AD 2020-0271 is incorporated by reference in the FAA final rule. This AD would, therefore, require compliance with EASA AD 2020-0271 in its entirety, through that incorporation, except for any differences identified as exceptions in the regulatory text of this AD. Using common terms that are the same as the heading of a particular section in the EASA AD does not mean that operators need comply only with that section. For example, where the AD requirement refers to ''all required actions and compliance times,'' compliance with this AD requirement is not limited to the section titled ''Required Action(s) and Compliance Time(s)'' in the EASA AD. Service information specified in EASA AD 2020-0271 that is required for compliance with EASA AD 2020-0271 is available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0512. \n\nFAA's Justification and Determination of the Effective Date \n\n\n\tSection 553(b)(3)(B) of the Administrative Procedure Act (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. TheFAA has found that the risk to the flying public justifies foregoing notice and comment prior to adoption of this rule because the in-flight failure of a stainless steel external ring bonded to the main rotor swashplate boot could result in damage to, and reduced control of, the helicopter. In addition, the compliance time for the required action is shorter than the time necessary for the public to comment and for publication of the final rule. Based on the average utilization rate for the affected Model AB139 and AW139 helicopters, it would take approximately one month for an affected helicopter to reach 25 hours time-in-service. Therefore, notice and \n\n((Page 33500)) \n\nopportunity for prior public comment are impracticable and contrary to 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 relevant data, views, or arguments about this AD. Send your comments to an address listed under ADDRESSES. Include ''Docket No. FAA-2021-0512; Project Identifier MCAI- 2020-01621-R'' at the beginning of your comments. The most helpful comments reference a specific portion of the AD, 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 AD 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 AD. \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 Darren Gassetto, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; telephone (516) 228- 7323; email Darren.Gassetto@faa.gov. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking. \n\nRegulatory Flexibility Act (RFA) \n\n\n\tThe requirements of the 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 the FAA has determined that it has good cause to adopt this rule without notice and comment, RFA analysis is not required. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 142 helicopters of U.S. registry. The FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Initial inspection of external boot 3 work-hours x $85 per $0 $255 $36,210 \n\trings and adhesive restoration. hour = $255. Reporting after initial inspection.... 1 work-hour x $85 per 0 85 12,070 \n\thour = $85. Repetitive inspections of boot rings 0.5 work-hour x $85 per 0 42.50 6,035 \n\tand adhesive. hour = $42.50 per \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\n\n\tEstimated Costs of On-Condition Actions ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Polishcorrosion.............................. 0.5 work-hour x $85 per hour = $0 $42.50 \n\t$42.50. Replace affected ring......................... 1 work-hour x $85 per hour = $85 300 385 Reapply adhesive.............................. 1 work-hour x $85 per hour = $85 0 85 ---------------------------------------------------------------------------------------------------------------- \n\nPaperwork Reduction Act \n\n\n\tA federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB control number. The control number for the collection of information required by this AD is 2120- 0056. The paperwork cost associated with this AD has been detailed in the Costs of Compliance section of this document and includes time for reviewing instructions, as well as completing and reviewing the collection of information. Therefore, all reporting associated with this AD is mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Pkwy., Fort Worth, TX 76177-1524. \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\n((Page 33501)) \n\nRegulatory Findings \n\n\n\tThe FAA determined that this AD would not have federalism implications under Executive Order 13132. This AD would 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 this regulation: \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.