{"id":"F2006B08395","name":"AD/CESSNA 500/20 Amdt 2 - Tailcone Skin and Vertical Fin Spar Interference","slug":"ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115838,"registerId":"commonwealth-F2006B08395-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 500/20 Amdt 2 - Tailcone Skin and Vertical Fin Spar Interference","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 500 (Citation) Series Aeroplanes\n\nAD/CESSNA 500/20\n\nAmdt 2\n\n  \n\nTailcone Skin and Vertical Fin Spar Interference\n\n  \n9/85\n\nApplicability: All models 500 and 501 with S/Nos 0001 to 0663\\. Requirement: Action in accordance with:\n\nCessna SB53-13 Rev 2 and Cessna SB55-4 (as applicable)\n\nCompliance: Unless already accomplished within, 100 hours time in service after 31 December 1983 or at the next scheduled inspection for Maintenance Release issue after 31 December 1983, whichever is the later.\n\nNote: No further action is required for aircraft previously inspected in accordance with Cessna S.L. No. SL53-2 and where no interference was detected.\n\nBackground: The manufacturer is aware that possible interference between the vertical fin forward spar and the upper tailcone skin may exist on the applicable aircraft.\n\nAmendment 2 of this Directive revises aircraft serial number applicability and the revision status of the Requirement Document.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2498},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"Amendment 2 revises the aircraft serial number applicability (which specific planes are covered) and updates the revision status of the referenced technical documents."},"complexity_factors":["Reliance on external technical documents (Cessna Service Bulletins) not reproduced in the directive","Conditional compliance deadline requiring comparison of two dates","Exemption clause for previously inspected aircraft"],"plain_english_summary":"A mandatory airworthiness directive requires owners of Cessna Model 500 and 501 jets (S/N 0001–0663) to inspect and, if needed, repair the forward spar/upper tailcone interference that can rub and damage the tail structure, following Cessna Service Bulletins 53‑13 (Rev 2) and 55‑4. Work must be done by the later of 100 flight hours after Dec 31, 1983, or the next scheduled inspection. Aircraft inspected per Service Letter SL53‑2 with no interference need take no action. Amendment 2 updates serials and document references."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference","history":"/api/acts/ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference/history","analysis":"/api/acts/ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference/analysis","conflicts":"/api/acts/ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference/conflicts","importantCases":"/api/acts/ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference/important-cases","documents":"/api/acts/ad-cessna-500-20-amdt-2-tailcone-skin-and-vertical-fin-spar-interference/documents"}}