Background \n\n\n\tThe European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Emergency AD 2021-0125-E, dated May 7, 2021 (referred to after this as ''the MCAI''), to address an unsafe condition for the specified products. The MCAI states: \n\n\n\tErrors have been identified in the ALS section of the EMM (Engine Maintenance Manual), including errors in the formula to determine the equivalent flight cycles of critical parts, and certain part numbers. It was also determined that, inadvertently, certain M601E engines have a compressor case P/N M601-154.61 installed, the life limit of which is not listed in the ALS section of the applicable EMM. \n\tThese conditions, if not corrected, may lead to operation of an engine beyond the life limit of one or more critical parts, possibly resulting in failure of the engine and consequent reduced control of the aeroplane. \n\tTo address this potential unsafe conditions, GEAC issued (GEAC Alert Service Bulletin (ASB) ASB-M601D-72-00-00-0075, ASB-M601E-72- 00-00-0106, ASB-M601F-72-00-00-0057 and ASB-M601Z-72-00-00-0057 (issued as a single document)), providing instructions to recalculate the consumed life of certain \n\n((Page 31602)) \n\ncritical parts, and (GEAC ASB-M601E-72-30-00-0105), providing instructions for certain M601E engines to replace the compressor case with an eligible part. \n\tFor the reason described above, this (EASA) AD requires replacement of critical parts, the recalculated life of which exceeds the applicable life limit, and replacement of the compressor case on certain M601E engines. \n\n\n\tYou may obtain further information by examining the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0499. \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 existor develop in other products of the same type design. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tThe FAA reviewed GE Aviation Czech ASB-M601F-72-00-00-0057 (00), ASB-M601E-72-00-00-0106 (00), ASB-M601D-72-00-00-0075 (00), and ASB- M601Z-72-00-00-0057 (00) (single document; formatted as service bulletin identifier (revision number)), dated May 7, 2021. This ASB specifies procedures for calculating consumed life of the critical parts. 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\nOther Related Service Information \n\n\n\tThe FAA reviewed GE Aviation Czech ASB-M601E-72-30-00-0105 (00) (formatted as service bulletin identifier (revision number)), dated May 7, 2021. This ASB introduces life limits to compressor case P/N M601- 154.61. \n\nAD Requirements \n\n\n\tThis AD requires recalculating the life of critical parts and, depending on the results of the recalculation, replacement of critical parts. This AD also requires replacement of compressor case, part number M601-154.61, installed on GEAC M601E model turboprop engines. \n\nDifferences Between the AD and the Service Information \n\n\n\tEASA Emergency AD 2021-0125-E, dated May 7, 2021, applies to GEAC M601D, M601D-1, M601D-2, M601D-11, M601D-11NZ, M601E, M601E-11, M601E- 11A, M601E-11AS, M601E-11S, M601E-21, M601F, M601FS, M601F-11, M601F- 22, M601F-32, M601T, and M601Z model turboprop engines. This AD does not include GEAC M601D, M601D-1, M601D-2, M601D-11NZ, M601E, M601E-21, M601FS, M601F-11, M601F-22, M601F-32, M601T, and M601Z model turboprop engines as these engine models are not type certificated in the United States. \n\nInterim Action \n\n\n\tThe FAA considers this AD to be an interim action. This unsafe condition is still under investigation by the manufacturer and, depending on the results of that investigation, the FAA may consider further rulemaking action.Justification 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. In May 2021, the FAA received a notification from the manufacturer about their discovery of errors with the formula for calculating the life limit of critical parts located in the ALS of the EMM. The manufacturer also discovered that compressor case, P/N M601-154.61, which was modified and installed in GEAC M601E model turboprop engines, had no corresponding life limit listed in the ALS of the corresponding EMM. As a result of discovering these errors, the manufacturer published service information providing instructions to update the formula used to recalculate life limits on critical parts and introduce a life limit for compressor case P/N M601-154.61. \n\tCritical parts exceeding their life limits can result in failure of the engine, further resulting in uncontained release of a critical part, damage to the engine, and damage to the airplane. The FAA considers the failure of a critical part to be an urgent safety issue that requires immediate action to avoid damage to the engine and airplane. \n\tAccordingly, notice and opportunity 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 ''Docket No. FAA-2021-0499 and Project Identifier MCAI-2021-00571-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 docketof this AD. Submissions containing CBI should be sent to Barbara Caufield, 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 \n\n((Page 31603)) \n\nan 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\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 9 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\tCostper Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Recalculate life of critical parts.... 1 work-hour x $85 per $0 $85 $765 \n\thour = $85. Replace compressor case............... 10 work-hours x $85 per 64,655 65,505 589,545 \n\thour = $850. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tThe FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. \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.