Comments 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 ''Docket No. FAA-2021-0782 and Project Identifier MCAI-2021-00915-A'' 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 Doug Rudolph, Aviation Safety Engineer, FAA, General Aviation & Rotorcraft Section, International Validation Branch, 901 Locust, Room 301, Kansas City, MO 64106. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. \n\nBackground \n\n\n\tThe European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0189-E, dated August 9, 2021 (referred to after this as ''the MCAI''), to address an unsafe condition on ELPROP 3-1-1P propellers that are installed on, but not limited to, AERO Models AT- 3R100 and AT-4LSA airplanes. The MCAI states: \n\n\n\tOccurrences have been reported of finding cracks on the propeller hub during service inspections. Cracks were detected on the propeller hub surface, near the blade attachment bolt holes and in the blade root area. \n\tThis condition, if not detected and corrected, could lead to loss of the propeller blade with consequent loss of control of the aeroplane. \n\tTo address this unsafe condition, AERO issued (mandatory service bulletin) MSB EPB.01.B to provide inspection instructions for certain propellers, and EASA issuedEmergency AD 2009-0134-E to require repetitive detailed visual inspections of those propeller hubs and, depending on findings, replacement. \n\tSince that (EASA) AD was issued, additional occurrences were reported of finding propeller hub cracks. Prompted by these findings, AERO issued MSB EPB.02.B applicable to propellers with s/n 3E.089 and higher. \n\tFor the reason described above, this (EASA) AD retains the requirements of EASA Emergency AD 2009-0134-E, which is superseded, and expands the Applicability to all propeller s/n. \n\n\n\tYou may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021- 0782. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tThe FAA reviewed AERO Mandatory Service Bulletin (MSB) EPB.01.B, Issue 1, dated May 14, 2009, which applies to propellers with serial numbers 3E.001 through 3E.088; and AERO MSB EPB.02.B, Issue 1, dated July 20, 2021, which applies to propellers with serial numbers 3E.089 and larger. This service information specifies procedures for inspecting the propeller hub for cracks and contacting the design approval holder for corrective action. This 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 ADDRESSES. \n\nFAA's Determination \n\n\n\tThis product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI and service information referenced above. The FAA is issuing this AD because it has determined the unsafe condition described previously is likely to exist or develop on other products of the same type design. \n\nAD Requirements \n\n\n\tThis AD requires accomplishing the actions specified in the service information already described. \n\nDifferences Between This AD and the MCAI \n\n\n\tThe MCAI applies to the Model AT-4LSA airplane, and this AD does not \n\n((Page 55687)) \n\nbecause it does not have an FAA type certificate. \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\tThe FAA has found that the risk to the flying public justifies foregoing notice and comment prior to adoption of this rule because there are noairplanes currently on the U.S. registry and thus, it is unlikely that the FAA will receive any adverse comments or useful information about this AD from U.S. operators. Accordingly, notice and opportunity for prior public comment are unnecessary pursuant to 5 U.S.C. 553(b)(3)(B). \n\tIn 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\nCosts of Compliance \n\n\n\tThere are currently no affected airplanes on the U.S. registry. In the event an affected airplane becomes a U.S. registered airplane, the following is an estimate of the costs to comply with this AD. \n\tThe FAA estimates that it would take .5 work-hour per airplane to comply with the inspection requirement in this AD. The average labor rate is $85 per work-hour. Based on these figures, the FAA estimates the cost of this AD to be $42.50 per airplane, per inspection cycle. \n\tCorrective action if cracks are found would vary significantly from airplane to airplane. Therefore, the FAA is unable to estimate what the cost of corrective action would be per airplane. \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 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\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.