Airworthiness Directives; International Aero Engines AG Engines

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-2555; Project Identifier AD-2025-00433-E]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; International Aero Engines AG Engines</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA proposes to adopt a new airworthiness directive (AD) for certain International Aero Engines AG (IAE AG) Model V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, V2531-E5, and V2533-A5 engines. This proposed AD was prompted by a manufacturer investigation that revealed that certain 3rd stage HPC rotor blades were susceptible to shroud wear and blade failure. This proposed AD would require replacement of affected 3rd stage HPC rotor blades with parts eligible for installation. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this proposed AD by January 2, 2026. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • <E T="03">Federal eRulemaking Portal:</E> Go to <E T="03">regulations.gov.</E> Follow the instructions for submitting comments. • <E T="03">Fax:</E> (202) 493-2251. • <E T="03">Mail:</E> U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. • <E T="03">Hand Delivery:</E> Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-2555; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Carol Nguyen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7655; email: <E T="03">carol.nguyen@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-2555; Project Identifier AD-2025-00433-E” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may revise this proposal because of those comments. Except 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 <E T="03">regulations.gov</E> , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. <HD SOURCE="HD1">Confidential Business Information</HD> CBI 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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Carol Nguyen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. <HD SOURCE="HD1">Background</HD> The FAA received multiple reports of failed 3rd stage HPC rotor blades that resulted in engine fires, unplanned engine removals, aborted takeoffs, and in-flight shutdowns (IFSD). A manufacturer investigation revealed that 3rd stage HPC rotor blade part numbers (P/Ns) 6A8353 or 6A8688, installed on IAE AG Model V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, V2531-E5, and V2533-A5 engines were susceptible to shroud wear and blade fractures. As a result, the manufacturer has developed an improved coating process that increases the durability of the shroud coating, mitigating wear and reducing the risk of blade fractures. This condition, if not addressed, could result in engine fire, reduced control of the airplane, and engine IFSD. <HD SOURCE="HD1">FAA's Determination</HD> The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. <HD SOURCE="HD1">Proposed AD Requirements in This NPRM</HD> This proposed AD would require a full set replacement of affected 3rd stage HPC rotor blades with parts eligible for installation. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD, if adopted as proposed, would affect 1,496 engines installed on aircraft of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: <GPOTABLE COLS="5" OPTS="L2,nj,i1" CDEF="s75,r50,10,10,12"> <TTITLE>Estimated Costs</TTITLE> <CHED H="1">Action</CHED> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> Cost on U.S. operators </CHED> <ROW> <ENT I="01">Replace full set of 3rd stage HPC rotor blades with reworked blades</ENT> <ENT>1 work-hours × $85 per hour = $85</ENT> <ENT>$30,000</ENT> <ENT>$30,085</ENT> <ENT>$45,007,160</ENT> </ROW> </GPOTABLE> <HD SOURCE="HD1">Authority for This Rulemaking</HD> Title 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. The 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. <HD SOURCE="HD1">Regulatory Findings</HD> The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed 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. For the reasons discussed above, I certify this proposed regulation: (1) Is not a “significant regulatory action” under Executive Order 12866, (2) Would not affect intrastate aviation in Alaska, and (3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. <LSTSUB> <HD SOURCE="HED">List of Subjects in 14 CFR Part 39</HD> Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. </LSTSUB> <HD SOURCE="HD1">The Proposed Amendment</HD> Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: <HD SOURCE="HED">PART 39—AIRWORTHINESS DIRECTIVES</HD> 1. The authority citation for part 39 continues to read as follows: <HD SOURCE="HED">Authority: </HD> 49 U.S.C. 106(g), 40113, 44701. <SECTION> <SECTNO>§ 39.13 </SECTNO> <SUBJECT>[Amended]</SUBJECT> </SECTION> 2. The FAA amends § 39.13 by adding the following new airworthiness directive: <EXTRACT> <FP SOURCE="FP-2"> <E T="04">International Aero Engines AG:</E> Docket No. FAA-2025-2555; Project Identifier AD-2025-00433-E. </FP> <HD SOURCE="HD1">(a) Comments Due Date</HD> The FAA must receive comments on this airworthiness directive (AD) by January 2, 2026. <HD SOURCE="HD1">(b) Affected ADs</HD> None. <HD SOURCE="HD1">(c) Applicability</HD> This AD applies to International Aero Engines AG (IAE AG) Model V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, V2531-E5, and V2533-A5 engines with a 3rd stage high-pressure compressor (HPC) rotor blade having part numbers (P/N) 6A8353 or P/N 6A8688 installed. <HD SOURCE="HD1">(d) Subject</HD> Joint Aircraft System Component (JASC) Code 7230, Turbine Engine Compressor Section. <HD SOURCE="HD1">(e) Unsafe Condition</HD> This AD was prompted by multiple reports of failed 3rd stage HPC rotor blades that resulted in engine fires, unplanned engine removals, aborted takeoffs, and in-flight shutdowns (IFSD). The FAA is issuing this AD to prevent failure of the 3rd stage HPC rotor blades. The unsafe condition, if not address ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 12k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━