{"abstract":"This amendment revises an existing airworthiness directive (AD), applicable to BMW Rolls-Royce GmbH (BRR) Models BR700-710A1-10 and BR700-710A2-20 turbofan engines. The existing AD requires initial and repetitive visual inspections of the engine compressor and combustion core fairings (also referred to as the engine core fairings) and fasteners for correct installation and damage, and verification that the engine core fairing fasteners are torqued to a higher torque value. This amendment increases the repetitive inspection interval to 150 hours time-in-service (TIS) following an initial inspection and follow-on inspection at the current 50 hours TIS interval. This amendment also requires an initial inspection and follow-on inspection at a 50 hours TIS interval following any engine core fairing or fastener removal, repair, or replacement. Repair of engine core fairings has been added as an alternate to engine core fairing replacement, and an inspection for loose engine core fairing(s) has been included to verify correct installation on the engine. Finally, this amendment adds a new paragraph in the compliance section allowing the option to incorporate redesigned core engine fairings as the terminating action to the required repetitive inspections. This amendment is prompted by results of repetitive inspections that indicate that the inspection interval can be increased safely, and by introduction of redesigned engine core fairings. The actions specified by this AD are intended to prevent engine compressor or combustion core fairing detachment and damage to the engine bypass duct, resulting in engine failure and damage to the airplane.","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/1999/11/19/99-29823.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"39","title":14}],"citation":"64 FR 63180","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"Effective December 27, 1999.","disposition_notes":null,"docket_ids":["Docket No. 98-ANE-74-AD","Amendment 39-11425","AD 98-24-03 R1"],"dockets":[],"document_number":"99-29823","effective_on":"1999-12-27","end_page":63182,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":null,"html_url":"https://www.federalregister.gov/documents/1999/11/19/99-29823/airworthiness-directives-bmw-rolls-royce-gmbh-models-br700--710a1-10-and-br700-710a2-20-turbofan","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/99-29823?publication_date=1999-11-19","mods_url":"https://www.govinfo.gov/metadata/granule/FR-1999-11-19/99-29823/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":29,"last_updated":"2026-08-24 18:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-1999-11-19/pdf/99-29823.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"1999-11-19","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/1999/11/19/99-29823.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":{"checked_regulationsdotgov_at":"2011-09-21T12:40:30Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":63180,"subtype":null,"title":"Airworthiness Directives; BMW Rolls-Royce GmbH Models BR700- 710A1-10 and BR700-710A2-20 Turbofan Engines","toc_doc":null,"toc_subject":null,"topics":[],"type":"Rule","volume":64}