Background \n\n\n\tThe EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2020-0282, dated December 17, 2020 (EASA AD 2020-0282) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for Airbus Helicopters Deutschland GmbH Model EC135 P1, EC135 P2, EC135 P2+, EC135 P3, EC135 T1, EC135 T2, EC135 T2+, EC135 T3, EC635 P2+, EC635 P3, EC635 T1, EC635 T2+, and EC635 T3 helicopters, all variants, all serial numbers. Model EC635 P2+, EC635 P3, EC635 T1, EC635 T2+, and EC635 T3 helicopters are not certificated by the FAA and are not included on the U.S. type certificate data sheet, except where the U.S. type certificate data sheet explains that the Model EC635T2+ helicopter having serial number 0858 was converted from Model EC635T2+ to Model EC135T2+. This AD, therefore, does not include Model EC635 P2+, EC635 P3, EC635 T1, EC635 T2+, and EC635 T3 helicopters in the applicability. \n\tFurthermore, although EASA AD 2020-0282 applies to all Model EC135 P1, EC135 P2, EC135 P2+, EC135 P3, EC135 T1, EC135 T2, EC135 T2+, and EC135 T3 helicopters, this AD applies to helicopters with an affected part installed instead. \n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Airbus Helicopters Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters. The NPRM published in the Federal Register on June 1, 2021 (86 FR 29216). The NPRM was prompted by a report that during an investigation related to an accident on an Airbus Helicopters Model EC130B4 helicopter, geometrical non-conformities were observed in the TRB root section. EASA issued AD 2020-0187, dated August 21, 2020, to address this issue on Model EC130B4 and EC130T2 helicopters and the FAA issued corresponding AD 2021-10-25, Amendment 39-21558 (86 FR 29176, June 1, 2021). The Airbus Helicopters Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters have a similar design and production requirements to the affected Model EC130B4 helicopter, and an inspection of the affected parts detected geometrical non-conformities in some instances. The NPRM proposed to require a one-time inspection (dimensional check) of the TRB for conformity and, depending on the findings, replacement of certain affected parts, as specified in EASA AD 2020-0282. The NPRM also proposed to prohibit rework, repair, or modification of affected parts in the affected area of the TRB assembly root. \n\tThe FAA is issuing this AD to address geometrical non-conformities in the TRB root section, which could lead to crack initiation and consequent blade failure, resulting in loss of control of the helicopter. See the MCAI for additional background information. \n\nComments \n\n\n\tThe FAA gave the public the opportunity to participatein developing this final rule. The FAA received no comments on the NPRM or on the determination of the cost to the public. \n\n((Page 50243)) \n\nConclusion \n\n\n\tThe FAA reviewed the relevant data 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 Service Information Under 1 CFR Part 51 \n\n\n\tEASA AD 2020-0282 requires a one-time inspection (dimensional check) to verify TRB conformity, and, depending on findings, replacement of each affected part classified as Category B (non- compliant TRB assembly). EASA AD 2020-0282 also prohibits rework, repair, or modification of affected parts in the critical section (affected area of the TRB assembly root). \n\tThis 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 341 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\tLabor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- 4 work-hours x $85 per hour = $340........................... $0 $340 $115,940 ---------------------------------------------------------------------------------------------------------------- \n\n\n\tThe FAA estimates the following costs to do any necessary on- condition actions that would be required based on the results of any required actions. The FAA has no way of determining the number of helicopters that might need these on-condition actions: \n\n\n\tEstimated Costs of On-Condition Actions ------------------------------------------------------------------------ \n\tCost per \n\tLabor cost Parts cost product ------------------------------------------------------------------------ 10 work-hours x $85 per hour = $850... $4,400 $5,250 ------------------------------------------------------------------------ \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.