{"abstract":"We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 787 airplanes. This AD requires a repetitive maintenance task for electrical power deactivation on Model 787 airplanes. This AD was prompted by the determination that a Model 787 airplane that has been powered continuously for 248 days can lose all alternating current (AC) electrical power due to the generator control units (GCUs) simultaneously going into failsafe mode. This condition is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power. We are issuing this AD to prevent loss of all AC electrical power, which could result in loss of control of 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/2015/05/01/2015-10066.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"80 FR 24789","comment_url":"http://www.regulations.gov/commenton/FAA-2015-0936-0001","comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD is effective May 1, 2015.","disposition_notes":null,"docket_ids":["Docket No. FAA-2015-0936","Directorate Identifier 2015-NM-058-AD","Amendment 39-18153","AD 2015-09-07"],"dockets":[{"supporting_documents":[{"title":"U.S. DOT/FAA - Various Supplemental AD Documents","document_id":"FAA-2015-0936-0004"}],"agency_name":null,"documents":[{"comment_count":4,"comment_start_date":"2015-05-01","updated_at":"2025-06-20T01:55:34.003-04:00","comment_url":"https://www.regulations.gov/commenton/FAA-2015-0936-0001","allow_late_comments":true,"id":"FAA-2015-0936-0001","comment_end_date":null,"regulations_dot_gov_open_for_comment":true}],"supporting_documents_count":1,"id":"FAA-2015-0936","title":"2015?NM?058?AD The Boeing Company Model 787 airplanes"}],"document_number":"2015-10066","effective_on":"2015-05-01","end_page":24791,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2015/05/01/2015-10066.xml","html_url":"https://www.federalregister.gov/documents/2015/05/01/2015-10066/airworthiness-directives-the-boeing-company-airplanes","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2015-10066?publication_date=2015-05-01","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2015-05-01/2015-10066/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":8584,"last_updated":"2026-04-04 18:15:03 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2015-05-01/pdf/2015-10066.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2015-10066.pdf?1430397936","publication_date":"2015-05-01","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2015/05/01/2015-10066.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 - Various Supplemental AD Documents","document_id":"FAA-2015-0936-0004"}],"regulatory_plan":{"html_url":"https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives","title":"Airworthiness Directives"},"comments_count":4,"agency_id":"FAA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2015-0936","supporting_documents_count":1,"docket_id":"FAA-2015-0936","document_id":"FAA-2015-0936-0001","regulation_id_number":"2120-AA64","title":"2015?NM?058?AD The Boeing Company Model 787 airplanes","checked_regulationsdotgov_at":"2025-06-21T08:55:03Z"},"regulations_dot_gov_url":"http://www.regulations.gov/commenton/FAA-2015-0936-0001","significant":false,"signing_date":null,"start_page":24789,"subtype":null,"title":"Airworthiness Directives; The Boeing Company Airplanes","toc_doc":"The Boeing Company Airplanes","toc_subject":"Airworthiness Directives:","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":80}