{"abstract":"The FAA proposes to adopt a new airworthiness directive (AD) for certain TCM IO-520, TSIO-520, and IO-550 reciprocating engines with certain SAP cylinder assemblies installed. This proposed AD would require initial and repetitive inspections and compression tests to detect cracks in those cylinders with more than 750 flight hours time- in-service (TIS). This proposed AD results from reports of cracks in the area of the exhaust valve and separation of cylinder heads from the barrels of SAP cylinder assemblies with certain part numbers. We are proposing this AD to prevent separation of the cylinder head, which could result in immediate loss of engine power, possible structural damage to the engine, and possible fire in the engine compartment.","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/2008/04/11/E8-7711.html","cfr_references":[{"chapter":null,"citation_url":null,"part":39,"title":14}],"citation":"73 FR 19772","comment_url":null,"comments_close_on":"2008-06-10","correction_of":null,"corrections":[],"dates":"We must receive any comments on this proposed AD by June 10, 2008.","disposition_notes":null,"docket_ids":["Docket No. FAA-2007-0051","Directorate Identifier 2007-NE-37-AD"],"dockets":[],"document_number":"E8-7711","effective_on":null,"end_page":19775,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2008/04/11/E8-7711.xml","html_url":"https://www.federalregister.gov/documents/2008/04/11/E8-7711/airworthiness-directives-teledyne-continental-motors-tcm-io-520-tsio-520-and-io-550-series-engines","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/E8-7711?publication_date=2008-04-11","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2008-04-11/E8-7711/mods.xml","not_received_for_publication":null,"page_length":4,"page_views":{"count":1588,"last_updated":"2026-08-26 12:15:06 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2008-04-11/pdf/E8-7711.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2008-04-11","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2008/04/11/E8-7711.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-2007-0051-0045"},{"title":"U.S. DOT/FAA - See Attachments","document_id":"FAA-2007-0051-0041"},{"title":"U.S. DOT/FAA -  See Attachment","document_id":"FAA-2007-0051-0039"},{"title":"U.S. DOT/FAA - See Attachments","document_id":"FAA-2007-0051-0038"},{"title":"U.S. DOT/FAA - See Attachments","document_id":"FAA-2007-0051-0036"}],"comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2007-0051","supporting_documents_count":5,"docket_id":"FAA-2007-0051","regulation_id_number":null,"title":"2007-NE-37-AD","checked_regulationsdotgov_at":"2011-11-14T02:23:48Z"},"regulations_dot_gov_url":null,"significant":false,"signing_date":null,"start_page":19772,"subtype":null,"title":"Airworthiness Directives; Teledyne Continental Motors (TCM) IO-520, TSIO-520, and IO-550 Series Engines with Superior Air Parts, Inc. (SAP) Cylinder Assemblies Installed","toc_doc":"Teledyne Continental Motors (TCM) IO-520, et al.","toc_subject":"Airworthiness Directives:","topics":["Air transportation","Aircraft","Aviation safety","Safety"],"type":"Proposed Rule","volume":73}