{"abstract":"The FAA is superseding an existing airworthiness directive (AD), which applies to all Model 737-300, -400, and -500 series airplanes. That AD currently requires inspecting to determine if certain carriage spindles are installed, repetitive inspections for corrosion and indications of corrosion on affected carriage spindles, and if necessary, related investigative and corrective actions. That AD also provides an optional terminating action. This new AD mandates the optional terminating action, which eliminates the need for the repetitive inspections. This AD results from reports of corrosion found on carriage spindles that are located on the outboard trailing edge flaps. We are issuing this AD to detect and correct corrosion of the carriage spindle, which could result in fracture. Fracture of both the inboard and outboard carriage spindles, in the forward ends through the large diameters, on a flap, could adversely affect the airplane's continued safe flight and landing.","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/2011/02/18/2011-3651.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"76 FR 9498","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This AD becomes effective March 25, 2011.","disposition_notes":null,"docket_ids":["Docket No. FAA-2010-0379","Directorate Identifier 2009-NM-210-AD","Amendment 39-16609","AD 2011-04-10"],"dockets":[],"document_number":"2011-3651","effective_on":"2011-03-25","end_page":9501,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2011/02/18/2011-3651.xml","html_url":"https://www.federalregister.gov/documents/2011/02/18/2011-3651/airworthiness-directives-the-boeing-company-model-737-300--400-and--500-series-airplanes","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2011-3651?publication_date=2011-02-18","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2011-02-18/2011-3651/mods.xml","not_received_for_publication":null,"page_length":4,"page_views":{"count":214,"last_updated":"2026-04-04 18:15:03 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2011-02-18/pdf/2011-3651.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2011-02-18","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2011/02/18/2011-3651.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":"2011-03-10T08:59:11Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":9498,"subtype":null,"title":"Airworthiness Directives; The Boeing Company Model 737-300, -400, and -500 Series Airplanes","toc_doc":"Boeing Co. Model 737300, 400, and 500 Series Airplanes","toc_subject":"Airworthiness Directives:","topics":["Air transportation","Aircraft","Aviation safety","Incorporation by reference","Safety"],"type":"Rule","volume":76}