Airworthiness Directives; Pratt & Whitney Turbofan Engines

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2023-2523; Project Identifier AD-2023-01086-E; Amendment 39-22709; AD 2024-06-04]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Pratt & Whitney Turbofan Engines</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney (PW) Model PW1519G, PW1521G, PW1521GA, PW1521G-3, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A engines. This AD was prompted by an updated analysis of an event involving an International Aero Engines, LLC (IAE LLC) Model PW1127GA-JM engine, which experienced a high-pressure compressor (HPC) 7th-stage integrally bladed rotor (IBR-7) separation that resulted in an engine shutdown and aborted takeoff. This AD requires performing an angled ultrasonic inspection (AUSI) of certain high-pressure turbine (HPT) 1st-stage hubs, HPT 2nd-stage hubs, and HPC 8th-stage disks for cracks and, depending on the results of the inspections, replacing the HPT 1st-stage hubs, HPT 2nd-stage hubs, or HPC 8th-stage disks. This AD also requires accelerated replacement of certain HPC 7th-stage rotors, HPC 8th-stage disks, HPC rear hubs, HPT 1st-stage hubs, HPT 2nd-stage hubs, HPT 1st-stage air seals, HPT 2nd-stage air seals, HPT 1st-stage blade retaining plates, and HPT 2nd-stage blade retaining plates. The FAA is issuing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This AD is effective April 11, 2024. The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of April 11, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2023-2523; 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 final rule, any comments received, and other information. The address for Docket Operations is 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">Material Incorporated by Reference:</E> • For Pratt & Whitney service information identified in this AD, contact International Aero Engines, LLC, 400 Main Street, East Hartford, CT 06118; phone: (860) 565-0140; email: <E T="03">help24@pw.utc.com;</E> website: <E T="03">connect.prattwhitney.com.</E> • You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2023-2523. <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">Background</HD> The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain PW Model PW1519G, PW1521G, PW1521GA, PW1521G-3, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A engines. The NPRM published in the <E T="04">Federal Register</E> on January 9, 2024 (89 FR 1038). The NPRM was prompted by an incident involving an Airbus Model A320neo airplane powered by IAE LLC Model PW1127GA-JM engines that experienced a failure of the HPC IBR-7 resulting in an engine shutdown and aborted take-off. Following this event, the manufacturer conducted a records review of production and field-returned parts and re-evaluated their engineering analysis methodology. The new analysis found that the failure of the HPC IBR-7 was caused by a nickel powdered metal anomaly, similar in nature to an anomaly previously observed. The analysis also concluded that there is an increased risk of failure for additional nickel powdered metal parts in certain nickel powdered metal production campaigns, and these parts are susceptible to failure much earlier than previously determined. In the NPRM, the FAA proposed to require performing an AUSI of certain HPT 1st-stage hubs, HPT 2nd-stage hubs, and HPC 8th-stage disks for cracks and, depending on the results of the inspections, replacing the HPT 1st-stage hubs, HPT 2nd-stage hubs, or HPC 8th-stage disks. The FAA also proposed to require accelerated replacement of certain HPC 7th-stage rotors, HPC 8th-stage disks, HPC rear hubs, HPT 1st-stage air seals, HPT 2nd-stage air seals, HPT 1st-stage hubs, HPT 2nd-stage hubs, HPT 1st-stage blade retaining plates, and HPT 2nd-stage blade retaining plates. The FAA is issuing this AD to address the unsafe condition on these products. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received comments from five commenters. The commenters were the Air Line Pilots Association, International (ALPA), Delta Air Lines, Inc. (DAL), Lufthansa Technik AG (Lufthansa), PW, and Transport Canada Civil Aviation (TCCA). ALPA supported the NPRM without change. DAL, Lufthansa, PW, and TCCA requested changes to the proposed AD. The following presents the comments received on the NPRM and the FAA's response to each comment. <HD SOURCE="HD1">Request To Clarify Unsafe Condition</HD> DAL requested that the FAA update paragraph (e) of the proposed AD or create a new paragraph to clarify why the HPC IBR-7 does not require repetitive AUSIs. Delta noted that the HPC IBR-7 was the part that originally separated during an event outlined in the proposed AD, leading to engine shutdown and aborted takeoff, which prompted this AD. The FAA disagrees with the request to update paragraph (e) or add a paragraph to the AD that clarifies why there are no repetitive AUSIs for the HPC IBR-7. The AUSI for the HPC IBR-7 was not available when the NPRM was written and to address the unsafe condition quickly, the FAA did not want to delay the issuance of this AD in order to add the AUSI for the HPC IBR-7. Since this AD is considered an interim action, the FAA will consider adding the AUSI for the HPC IBR-7 or other actions in the future. The FAA did not change this AD as a result of this comment. <HD SOURCE="HD1">Request To Update Definition for Parts Eligible for Installation</HD> DAL requested that the FAA update paragraph (i)(3) of the proposed AD to clarify installation eligibility for new/not service run HPC/HPT hardware that is not currently installed on an engine. Delta stated that HPC/HPT hardware scanned at production are scanned per the non-destructive inspection procedure (NDIP) and may not list service bulletin status so clarification is needed to determine hardware eligibility based off service bulletin status as well as NDIP status. The FAA disagrees with the request to update the definition of parts eligible for installation to include new/not service run parts because new parts inspected at production would not have the NDIP listed in their paperwork. The service documents require the AUSI of new parts prior to installation with no allowance for parts inspected at production. The FAA did not change this AD as a result of this comment. <HD SOURCE="HD1">Request To Update Definition of Engine Shop Visit and HPC Engine Shop Visit</HD> DAL requested that the FAA update the definitions for “engine shop visit” and “HPC engine shop visit” in paragraph (i)(5) and (6) of the proposed AD to provide clarity and avoid ambiguity. Delta noted that the definition for “engine shop visit” includes the term “pairs” when defining separation of major mating engine flanges. Delta stated that this does not clearly define what constitutes an “engine shop visit,” as the term “pairs” may be interpreted as separation of two or more different lettered flanges. Delta also stated that the phrase “when the HPC rotor assembly is removed from the engine” used in the definition for an “HPC engine shop visit” does not clearly describe the different scenarios that may constitute HPC engine shop visits since the HPC rotor assembly can be at different levels of exposure depending on the shop visit type. The FAA partially agrees with the request. The FAA agrees to update the definition of an “HPC shop visit” in paragraph (i)(6) of this AD to: “For the purposes of this AD, an `HPC engine shop visit' is when the HPC rotor assembly is removed from the HPC module.” The FAA disagrees with the request to update the definition for an “engine shop visit” because the definition used in this AD is standard and taken from the World Airlines Technical Operations Glossary. The FAA notes that the term “pairs” of major mating engine flanges refers to the mating surfaces on each individual part of the bolted joint. <HD SOURCE="HD1">Request To Include Alert Service Bulletin (ASB) Issue Numbers in Tables</HD> DAL requested that the FAA update Table 1 to Paragraph (g)(3) and Table 2 to Paragraph (g)(7) of the proposed AD to include the issue numbers of the ASBs that are listed in the Applicable (serial number) S/N listing, Applicable service bulletin and the Table S/N is listed in columns. DAL noted that certain ASBs, such as 72-00-0196 Issue 002, were revised to include additional serial numbers in the effectivity, so different ASB issue numbers contain different serial number effectivity. The FAA agrees with the request and has ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 41k characters. 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