{"abstract":"We are adopting a new airworthiness directive (AD) for certain Bell Model 206B and 206L helicopters. This AD requires installing a placard beneath the engine power dual tachometer and revising the operating limitations section of the rotorcraft flight manual (RFM). This AD was prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady-state operations. These actions are intended to alert pilots to avoid certain engine speeds during steady- state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter.","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/2013/11/05/2013-24037.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"78 FR 66252","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD is effective December 10, 2013.","disposition_notes":null,"docket_ids":["Docket No. FAA-2013-0488","Directorate Identifier 2008-SW-002-AD","Amendment 39-17619","AD 2013-20-13"],"dockets":[],"document_number":"2013-24037","effective_on":"2013-12-10","end_page":66254,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2013/11/05/2013-24037.xml","html_url":"https://www.federalregister.gov/documents/2013/11/05/2013-24037/airworthiness-directives-bell-helicopter-textron-canada-limited-bell-helicopters","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2013-24037?publication_date=2013-11-05","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2013-11-05/2013-24037/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":154,"last_updated":"2026-08-26 06:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2013-11-05/pdf/2013-24037.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2013-24037.pdf?1383572907","publication_date":"2013-11-05","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2013/11/05/2013-24037.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":{"supporting_documents":[{"title":"U.S. DOT/FAA - See Attachments","document_id":"FAA-2013-0488-0005"},{"title":"U.S. DOT/FAA - See Attachments","document_id":"FAA-2013-0488-0002"}],"regulatory_plan":{"html_url":"https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives","title":"Airworthiness Directives"},"comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2013-0488","supporting_documents_count":2,"docket_id":"FAA-2013-0488","regulation_id_number":"2120-AA64","title":"2008-SW-002-AD Bell Helicopter Textron Canada, Ltd., Models 206B and 206L, to require revising the limitations in the rotorcraft flight manual of steady-state operations and installing a placard.","checked_regulationsdotgov_at":"2013-11-25T06:00:10Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":66252,"subtype":null,"title":"Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters","toc_doc":"Bell Helicopter Textron Canada Limited (Bell) Helicopters","toc_subject":"Airworthiness Directives:","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":78}