{"abstract":"The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to certain serial numbers (SN's) of NARCO Avionics Inc. AT150 transponders. This proposal would require modification to the transponder by adding a resistor and transistor to the circuit board. This proposal is prompted by reports of AT150 transponders not recognizing and responding properly to Mode S interrogations from Mode S ground stations and Traffic Alert and Collision Avoidance System (TCAS-II) airborne equipment. The actions specified by the proposed AD are intended to prevent loss of aircraft airspace separation and the possibility of mid-air collision.","action":"Notice of proposed rulemaking (NPRM).","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/2003/02/20/03-4056.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"68 FR 8161","comment_url":null,"comments_close_on":"2003-04-21","correction_of":null,"corrections":[],"dates":"Comments must be received by April 21, 2003.","disposition_notes":null,"docket_ids":["Docket No. 2002-NE-32-AD"],"dockets":[],"document_number":"03-4056","effective_on":null,"end_page":8162,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2003/02/20/03-4056.xml","html_url":"https://www.federalregister.gov/documents/2003/02/20/03-4056/airworthiness-directives-narco-avionics-inc-at150-transponders","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/03-4056?publication_date=2003-02-20","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2003-02-20/03-4056/mods.xml","not_received_for_publication":null,"page_length":2,"page_views":{"count":505,"last_updated":"2026-08-24 20:15:14 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2003-02-20/pdf/03-4056.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2003-02-20","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2003/02/20/03-4056.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":{},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":8161,"subtype":null,"title":"Airworthiness Directives; NARCO Avionics Inc. AT150 Transponders","toc_doc":"NARCO Avionics Inc.","toc_subject":"Airworthiness directives:","topics":["Air transportation","Aircraft","Aviation safety","Safety"],"type":"Proposed Rule","volume":68}