{"abstract":"We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires installing new in-line fuses for the fuel level float switch and new in-line fuses for the pressure switch, as applicable, and changing the wiring. The proposed actions would affect the left and right wing forward spars, center wing forward spar, forward auxiliary fuel tank, and aft auxiliary fuel tank, as applicable. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.","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/2011/04/01/2011-6633.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"76 FR 18022","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD is effective May 6, 2011.","disposition_notes":null,"docket_ids":["Docket No. FAA-2010-0958","Directorate Identifier 2010-NM-188-AD","Amendment 39-16641","AD 2011-07-04"],"dockets":[],"document_number":"2011-6633","effective_on":"2011-05-06","end_page":18024,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2011/04/01/2011-6633.xml","html_url":"https://www.federalregister.gov/documents/2011/04/01/2011-6633/airworthiness-directives-the-boeing-company-model-dc-9-14-dc-9-15-and-dc-9-15f-airplanes-and-dc-9-20","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2011-6633?publication_date=2011-04-01","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2011-04-01/2011-6633/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":338,"last_updated":"2026-04-04 10:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2011-04-01/pdf/2011-6633.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2011-04-01","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2011/04/01/2011-6633.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":{"checked_regulationsdotgov_at":"2011-04-21T08:04:13Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":18022,"subtype":null,"title":"Airworthiness Directives; The Boeing Company Model DC-9-14, DC-9-15, and DC-9-15F Airplanes; and DC-9-20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes","toc_doc":"Boeing Co. Model DC914, DC915, and DC915F Airplanes; and DC920, DC930, DC940, and DC950 Series Airplanes","toc_subject":"Airworthiness Directives:","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":76}