{"abstract":"We are adopting a new airworthiness directive (AD) for all Pratt & Whitney Division (PW) turbofan engine model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 with a certain second- stage high-pressure turbine (HPT) air seal part number installed. This AD was prompted by discovery of cracks in second-stage HPT air seals. This AD requires inspection and removal from service of HPT air seals that fail inspection. We are issuing this AD to prevent failure of the second-stage HPT air seal, which could lead to an uncontained engine failure and damage to the airplane.","action":"Final rule.","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/2013/08/13/2013-19429.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"78 FR 49111","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD is effective September 17, 2013. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of September 17, 2013.","disposition_notes":null,"docket_ids":["Docket No. FAA-2013-0072","Directorate Identifier 2013-NE-04-AD","Amendment 39-17525","AD 2013-15-09"],"dockets":[],"document_number":"2013-19429","effective_on":"2013-09-17","end_page":49113,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2013/08/13/2013-19429.xml","html_url":"https://www.federalregister.gov/documents/2013/08/13/2013-19429/airworthiness-directives-pratt-and-whitney-division-turbofan-engines","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2013-19429?publication_date=2013-08-13","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2013-08-13/2013-19429/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":139,"last_updated":"2026-04-04 20:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2013-08-13/pdf/2013-19429.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2013-19429.pdf?1376311995","publication_date":"2013-08-13","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2013/08/13/2013-19429.txt","regulation_id_number_info":{"2120-AA64":{"issue":"202410","html_url":"https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives","title":"Airworthiness Directives","xml_url":"http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=202410&RIN=2120-AA64&operation=OPERATION_EXPORT_XML","priority_category":"Routine and Frequent"}},"regulation_id_numbers":["2120-AA64"],"regulations_dot_gov_info":{"checked_regulationsdotgov_at":"2013-11-05T05:01:15Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":49111,"subtype":null,"title":"Airworthiness Directives; Pratt & Whitney Division Turbofan Engines","toc_doc":"Pratt and Whitney Division Turbofan Engines","toc_subject":"Airworthiness Directives:","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":78}