{"abstract":"The FAA is adopting a new airworthiness directive (AD) for all Bell Textron Canada Limited (BTCL) Model 407 and 427 helicopters. This AD was prompted by a report that certain expandable blade bolts installed on the main rotor blade may not have received the correct heat treatment, which could result in stress corrosion cracking of the expandable blade bolts. This AD requires removing the expandable blade bolts from service and replacing them with a part eligible for installation. This AD also prohibits the installation of an affected expandable blade bolt on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.","action":"Final rule; request for comments.","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/2025/06/23/2025-11449.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"39","title":14}],"citation":"90 FR 26424","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD is effective July 8, 2025.","disposition_notes":null,"docket_ids":["Docket No. FAA-2025-1111","Project Identifier MCAI-2025-00675-R","Amendment 39-23067","AD 2025-13-01"],"dockets":[{"supporting_documents":[],"agency_name":"FAA","documents":[{"comment_count":0,"comment_start_date":"2025-06-23","updated_at":"2025-08-08T00:04:50.544-04:00","comment_url":"https://www.regulations.gov/commenton/FAA-2025-1111-0001","allow_late_comments":false,"id":"FAA-2025-1111-0001","comment_end_date":"2025-08-08","regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":0,"id":"FAA-2025-1111","title":"MCAI-2025-00675-R; : Bell Textron Canada Limited 407, 427 – Expandable Blade Bolt incorrect heat treatment"}],"document_number":"2025-11449","effective_on":"2025-07-08","end_page":26427,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2025/06/23/2025-11449.xml","html_url":"https://www.federalregister.gov/documents/2025/06/23/2025-11449/airworthiness-directives-bell-textron-canada-limited-helicopters","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2025-11449?publication_date=2025-06-23","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2025-06-23/2025-11449/mods.xml","not_received_for_publication":null,"page_length":4,"page_views":{"count":362,"last_updated":"2026-08-25 14:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2025-06-23/pdf/2025-11449.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2025-11449.pdf?1750259709","publication_date":"2025-06-23","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2025/06/23/2025-11449.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":0,"agency_id":"FAA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2025-1111","supporting_documents_count":0,"docket_id":"FAA-2025-1111","document_id":"FAA-2025-1111-0001","regulation_id_number":"2120-AA64","title":"MCAI-2025-00675-R; : Bell Textron Canada Limited 407, 427 – Expandable Blade Bolt incorrect heat treatment","checked_regulationsdotgov_at":"2025-08-08T04:04:49Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":26424,"subtype":null,"title":"Airworthiness Directives; Bell Textron Canada Limited Helicopters","toc_doc":"Bell Textron Canada Limited Helicopters","toc_subject":"Airworthiness Directives","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":90}