{"abstract":"This amendment revises the hydraulic systems design and test requirements of the airworthiness standards for transport category airplanes. The amendment adds appropriate existing Joint Aviation Requirements (JAR) standards to achieve harmonization; moves some of the existing regulatory text to a new advisory circular (AC) 25.1435-1; consolidates and/or separates certain subparagraphs for clarity; and revises airplane static proof pressure test requirements to allow a complete functional (dynamic) airplane test at the hydraulic system relief pressure. These revisions were developed in cooperation with the Joint Aviation Authorities (JAA) of Europe, Transport Canada, and the U.S. and European aviation industry through the Aviation Rulemaking Advisory Committee (ARAC). These changes benefit the public interest by standardizing certain requirements, concepts, and procedures contained in the airworthiness standards without reducing, but potentially enhancing, the current level of safety.","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/2001/05/16/01-12232.html","cfr_references":[{"chapter":null,"citation_url":null,"part":25,"title":14}],"citation":"66 FR 27396","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"Effective June 15, 2001.","disposition_notes":null,"docket_ids":["Docket No. 28617","Amendment No. 25-104"],"dockets":[],"document_number":"01-12232","effective_on":"2001-06-15","end_page":27403,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2001/05/16/01-12232.xml","html_url":"https://www.federalregister.gov/documents/2001/05/16/01-12232/revision-of-hydraulic-systems-airworthiness-standards-to-harmonize-with-european-airworthiness","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/01-12232?publication_date=2001-05-16","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2001-05-16/01-12232/mods.xml","not_received_for_publication":null,"page_length":8,"page_views":{"count":606,"last_updated":"2026-07-27 08:15:03 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2001-05-16/pdf/01-12232.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2001-05-16","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2001/05/16/01-12232.txt","regulation_id_number_info":{"2120-AF79":{"issue":"200104","html_url":"https://www.federalregister.gov/regulations/2120-AF79/revision-of-hydraulics-systems-airworthiness-standards-to-harmonize-with-european-airworthiness-stan","title":"Revision of Hydraulics Systems Airworthiness Standards To Harmonize With European Airworthiness Standards for Transport Category Airplanes","xml_url":"http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=200104&RIN=2120-AF79&operation=OPERATION_EXPORT_XML","priority_category":"Substantive, Nonsignificant"}},"regulation_id_numbers":["2120-AF79"],"regulations_dot_gov_info":{},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":27396,"subtype":null,"title":"Revision of Hydraulic Systems Airworthiness Standards To Harmonize With European Airworthiness Standards for Transport Category Airplanes","toc_doc":"Hydraulic systems standards revision to harmonize with European standards","toc_subject":"Airworthiness standards:","topics":["Aircraft","Aviation safety","Reporting and recordkeeping requirements"],"type":"Rule","volume":66}