{"abstract":"The FAA is superseding Airworthiness Directive (AD) 2021-20-10 for certain Leonardo S.p.a. Model AB139 and AW139 helicopters. AD 2021- 20-10 required removing from service a certain part-numbered main gearbox (MGB) spherical bearing lock nut (lock nut) that is installed on certain part-numbered MGBs and replacing it with a newly designed MGB lock nut. AD 2021-20-10 also prohibited installing any MGB with the affected MGB lock nut and prohibited installing any affected MGB lock nut on any helicopter. Since the FAA issued AD 2021-20-10, it was discovered that a part number (P/N) was incorrectly listed and that the applicability needed to be clarified. This AD retains the requirements of AD 2021-20-10 and clarifies the applicability. The FAA is issuing this AD to address the unsafe condition on these products.","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/2022/12/27/2022-28090.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"39","title":14}],"citation":"87 FR 79232","comment_url":"https://www.regulations.gov/commenton/FAA-2022-0465-0007","comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD is effective January 31, 2023.","disposition_notes":null,"docket_ids":["Docket No. FAA-2022-0465","Project Identifier AD-2022-00330-R","Amendment 39-22288","AD 2022-27-03"],"dockets":[{"supporting_documents":[{"title":"U.S. DOT/FAA – Supplemental AD Documents","document_id":"FAA-2022-0465-0008"},{"title":"Supporting AD Documents","document_id":"FAA-2022-0465-0002"}],"agency_name":"FAA","documents":[{"comment_count":0,"comment_start_date":"2022-12-27","updated_at":"2024-11-06T21:45:03.695-05:00","comment_url":"https://www.regulations.gov/commenton/FAA-2022-0465-0007","allow_late_comments":true,"id":"FAA-2022-0465-0007","comment_end_date":null,"regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":2,"id":"FAA-2022-0465","title":"AD-2022-00330-R Leonardo S.p.a. AB139, AW139  Main Rotor Drive – Main Gearbox Bearing Lock Nut"}],"document_number":"2022-28090","effective_on":"2023-01-31","end_page":79235,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2022/12/27/2022-28090.xml","html_url":"https://www.federalregister.gov/documents/2022/12/27/2022-28090/airworthiness-directives-leonardo-spa-helicopters","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2022-28090?publication_date=2022-12-27","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2022-12-27/2022-28090/mods.xml","not_received_for_publication":null,"page_length":4,"page_views":{"count":480,"last_updated":"2026-08-25 10:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2022-12-27/pdf/2022-28090.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2022-28090.pdf?1671803134","publication_date":"2022-12-27","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2022/12/27/2022-28090.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":[{"title":"U.S. DOT/FAA – Supplemental AD Documents","document_id":"FAA-2022-0465-0008"},{"title":"Supporting AD Documents","document_id":"FAA-2022-0465-0002"}],"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-2022-0465","supporting_documents_count":2,"docket_id":"FAA-2022-0465","document_id":"FAA-2022-0465-0007","regulation_id_number":"2120-AA64","title":"AD-2022-00330-R Leonardo S.p.a. AB139, AW139  Main Rotor Drive – Main Gearbox Bearing Lock Nut","checked_regulationsdotgov_at":"2024-11-07T22:00:16Z"},"regulations_dot_gov_url":"https://www.regulations.gov/commenton/FAA-2022-0465-0007","significant":false,"signing_date":null,"start_page":79232,"subtype":null,"title":"Airworthiness Directives; Leonardo S.p.a. Helicopters","toc_doc":"Leonardo S.p.a. Helicopters","toc_subject":"Airworthiness Directives:\n","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":87}