Background \n\n\n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters with serial number (S/N) up to and including 1254 (except S/N 1235). The NPRM published in the Federal Register on April 16, 2021 (86 FR 20089). In the NPRM, the FAA proposed to require modifying the T/R control within 360 hours time-in-service (TIS) by installing a Teflon washer and performing a functional test in accordance with specified portions of Airbus Helicopters Alert Service Bulletin ASB EC135-67A-031, Revision 0, dated March 30, 2017 (ASB EC135-67A-031). Based on the results of the functional test, the NPRM proposed to require making repairs in accordance with FAA-approved procedures. The NPRM was prompted by EASA AD 2017-0147, dated August 10, 2017 (EASA AD 2017-0147), issued by EASA, which is the Technical Agent for the Member States of the European Union, to correct an unsafe condition for Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and EC635T3 helicopters. EASA advises that several cases of insufficient clearance between a certain T/R bearing connection and the helicopter structure were detected during inspections of helicopters on the production line. EASA states that this condition, if not corrected and in the case of an unglued bearing, could lead to blockage of the pedal controlling the T/R thrust and loss of the T/R control. EASA further advises that this could result in a forced landing with damage to the helicopter and injury to the occupants. \n\tAccordingly, EASA AD 2017-0147 requires modifying the T/R control installation by adding a Teflon washer, which reduces the degree of freedom in case of a drifting bearing at the affected connection. EASA AD 2017-0147 also requires a functional test for clearance, and depending on the results, either accomplishing additional corrective actions or contacting Airbus Helicopters for instructions. \n\nComments \n\n\n\tThe FAA received no comments on the NPRM or on the determination of the costs. \n\nConclusion \n\n\n\tThese helicopters have been approved by EASA and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the European Union, EASA has notified the FAA about the unsafe condition described in its AD. The FAA reviewed the relevant data and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these helicopters. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tThe FAA reviewed ASB EC135-67A-031 for Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and EC635T3 helicopters. For S/Ns up to 1254 inclusive, except S/N 1235, this service information specifies retrofitting a Teflon washer on the T/R controls, performing a functional test of the modified T/R control installation to inspect for clearance, and making any necessary adjustments. This service information advises that S/N 1255 and up will have the Teflon washer installed in production. \n\tThis service information 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\nDifferences Between This AD and the EASA AD \n\n\n\tThe EASA AD sets compliance times at 12 months, while this AD requires compliance within 360 hours TIS. The EASA AD applies to Airbus Helicopters Model EC635T1, EC635T2+, EC635T3, EC635P2+, and EC635P3 helicopters; this AD does not because these models do not have an FAA type certificate. The EASA AD requires contacting Airbus Helicopters for approved repair procedures; this AD requires a repair using FAA- approved procedures. The EASA AD requires revising the ''aircraft maintenance program,'' whereas this AD does not because not all U.S. operators are required to have a maintenance program. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 331 helicopters of U.S. registry. Labor rates are estimated at $85 per work-hour. Based on these numbers, the FAA estimates the following costs to comply with this AD. \n\tModifying the T/R control installation and conducting a functional test takes about 3 work-hours and parts cost about $25 for an estimated cost of $280 per helicopter and $92,680 for the U.S. fleet. \n\tIf required, adjusting the clearance takes about 1 work-hour for an estimated cost of $85 per helicopter. \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 helicopters 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 \n\n((Page 35601)) \n\nresponsibilities 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.