{"abstract":"The FAA is adopting a new airworthiness directive (AD) for all BRP-Rotax GmbH & Co KG (Rotax) Model 915 iSc2 C24 and 915 iSc3 C24 engines. This AD was prompted by a report of a certain collar nut that was not installed on the propeller gearbox. This AD requires a visual inspection of the propeller gearbox to determine if a collar nut is installed on the propeller shaft and, if not installed, replacement of the propeller gearbox with a serviceable propeller gearbox. 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/2026/03/04/2026-04280.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"91 FR 10513","comment_url":"http://www.regulations.gov/commenton/FAA-2026-1321-0001","comments_close_on":"2026-04-20","correction_of":null,"corrections":[],"dates":"This AD is effective March 19, 2026.","disposition_notes":null,"docket_ids":["Docket No. FAA-2026-1321","Project Identifier MCAI-2025-01769-E","Amendment 39-23261","AD 2026-04-02"],"dockets":[{"supporting_documents":[{"title":"U.S. DOT/FAA - Supplemental AD Documents","document_id":"FAA-2026-1321-0002"}],"agency_name":"FAA","documents":[{"comment_count":0,"comment_start_date":"2026-03-04","updated_at":"2026-03-04T09:58:07.255-05:00","comment_url":"https://www.regulations.gov/commenton/FAA-2026-1321-0001","allow_late_comments":false,"id":"FAA-2026-1321-0001","comment_end_date":"2026-04-21","regulations_dot_gov_open_for_comment":true}],"supporting_documents_count":1,"id":"FAA-2026-1321","title":"MCAI-2025-01769-E; BRP-Rotax GmbH & Co KG Model 915 iSc2 C24, 915 iSc3 C24 Engines; Engine – Propeller Gearbox – Inspection"}],"document_number":"2026-04280","effective_on":"2026-03-19","end_page":10515,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/03/04/2026-04280.xml","html_url":"https://www.federalregister.gov/documents/2026/03/04/2026-04280/airworthiness-directives-brp-rotax-gmbh-and-co-kg-formerly-brp-powertrain-gmbh-and-co-kg-and","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-04280?publication_date=2026-03-04","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-03-04/2026-04280/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":118,"last_updated":"2026-04-04 22:15:03 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-03-04/pdf/2026-04280.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-04280.pdf?1772545522","publication_date":"2026-03-04","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/03/04/2026-04280.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-2026-1321-0002"}],"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-2026-1321","supporting_documents_count":1,"docket_id":"FAA-2026-1321","document_id":"FAA-2026-1321-0001","regulation_id_number":"2120-AA64","title":"MCAI-2025-01769-E; BRP-Rotax GmbH & Co KG Model 915 iSc2 C24, 915 iSc3 C24 Engines; Engine – Propeller Gearbox – Inspection","checked_regulationsdotgov_at":"2026-03-05T17:55:03Z"},"regulations_dot_gov_url":"http://www.regulations.gov/commenton/FAA-2026-1321-0001","significant":false,"signing_date":null,"start_page":10513,"subtype":null,"title":"Airworthiness Directives; BRP-Rotax GmbH & Co KG (Formerly BRP-POWERTRAIN GMBH & CO KG and Bombardier-Rotax GmbH) Engines","toc_doc":"BRP-Rotax GmbH and Co KG (Formerly BRP-POWERTRAIN GMBH and CO KG and Bombardier-Rotax GmbH) Engines","toc_subject":"Airworthiness Directives","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":91}