{"abstract":"The FAA proposes to adopt a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) Model PW4074D, PW4077D, PW4084D, PW4090, and PW4090-3 engines. This proposed AD was prompted by the discovery of a quality escape involving incorrect shot peening on certain high-pressure compressor (HPC) drum rotor disk assemblies. This proposed AD would require visually inspecting the HPC drum rotor disk assembly for incorrect shot peen coverage and, depending on the results of the inspection, replacing the HPC drum rotor disk assembly with a part eligible for installation. This proposed AD would also require removing and replacing certain HPC drum rotor disk assemblies before reaching certain life limits. The FAA is proposing this AD to address the unsafe condition on these products.","action":"Notice of proposed rulemaking (NPRM).","agencies":[{"raw_name":"DEPARTMENT OF TRANSPORTATION","name":"Transportation Department","id":492,"url":"https://www.federalregister.gov/agencies/transportation-department","json_url":"https://www.federalregister.gov/api/v1/agencies/492","parent_id":null,"slug":"transportation-department"},{"raw_name":"Federal Aviation Administration","name":"Federal Aviation Administration","id":159,"url":"https://www.federalregister.gov/agencies/federal-aviation-administration","json_url":"https://www.federalregister.gov/api/v1/agencies/159","parent_id":492,"slug":"federal-aviation-administration"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2026/03/24/2026-05686.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"39","title":14}],"citation":"91 FR 13984","comment_url":null,"comments_close_on":"2026-05-08","correction_of":null,"corrections":[],"dates":"The FAA must receive comments on this proposed AD by May 8, 2026.","disposition_notes":null,"docket_ids":["Docket No. FAA-2026-2724","Project Identifier AD-2025-01606-E"],"dockets":[{"supporting_documents":[],"agency_name":"FAA","documents":[{"comment_count":3,"comment_start_date":"2026-03-24","updated_at":"2026-05-09T01:56:41.865-04:00","comment_url":"https://www.regulations.gov/commenton/FAA-2026-2724-0001","allow_late_comments":false,"id":"FAA-2026-2724-0001","comment_end_date":"2026-05-09","regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":0,"id":"FAA-2026-2724","title":"AD-2025-01606-E; Pratt & Whitney Division Model PW4074D, PW4077D, PW4084D, PW4090, and PW4090-3 engines; high-pressure compressor (HPC) drum rotor disk assemblies"}],"document_number":"2026-05686","effective_on":null,"end_page":13987,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/03/24/2026-05686.xml","html_url":"https://www.federalregister.gov/documents/2026/03/24/2026-05686/airworthiness-directives-pratt-and-whitney-division-engines","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-05686?publication_date=2026-03-24","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-03-24/2026-05686/mods.xml","not_received_for_publication":null,"page_length":4,"page_views":{"count":220,"last_updated":"2026-06-16 20:15:03 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-03-24/pdf/2026-05686.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-05686.pdf?1774269910","publication_date":"2026-03-24","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/03/24/2026-05686.txt","regulation_id_number_info":{"2120-AA64":{"issue":"202504","html_url":"https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives","title":"Airworthiness Directives","xml_url":"http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=202504&RIN=2120-AA64&operation=OPERATION_EXPORT_XML","priority_category":"Routine and Frequent"}},"regulation_id_numbers":["2120-AA64"],"regulations_dot_gov_info":{"supporting_documents":[],"regulatory_plan":{"html_url":"https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives","title":"Airworthiness Directives"},"comments_count":3,"agency_id":"FAA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2026-2724","supporting_documents_count":0,"docket_id":"FAA-2026-2724","document_id":"FAA-2026-2724-0001","regulation_id_number":"2120-AA64","title":"AD-2025-01606-E; Pratt & Whitney Division Model PW4074D, PW4077D, PW4084D, PW4090, and PW4090-3 engines; high-pressure compressor (HPC) drum rotor disk assemblies","checked_regulationsdotgov_at":"2026-05-10T01:55:11Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":13984,"subtype":null,"title":"Airworthiness Directives; Pratt & Whitney Division Engines","toc_doc":"Pratt and Whitney Division Engines","toc_subject":"Airworthiness Directives","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Proposed Rule","volume":91}