{"id":"F2006B08344","name":"AD/CESSNA 400/59 - Fuselage Tailcone Structure - Modification","slug":"ad-cessna-400-59-fuselage-tailcone-structure-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115751,"registerId":"commonwealth-F2006B08344-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/59 - Fuselage Tailcone Structure - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Cessna 400 Series Aeroplanes\n\n \n\nAD/CESSNA 400/59 Fuselage Tailcone Structure - Modification 11/78\n\nApplicability: All 401 and 411 series.\n\nAll model 402 with S/Nos. 402-0001 to 402B1361; All model 404 with S/Nos. 404-0001 to 404-0233; All model 414 with S/Nos. 414-0001 to 414A0071; All model 421 with S/Nos. 421-0001 to 421C0511; All model 441 with S/Nos. 441-0001 to 441-0059.\n\n \n\nDocument: Cessna SL ME78-24.\n\n \n\nCompliance: Within 100 hours time in service after 30 November 1978.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1976},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"The directive retains its original narrow scope, targeting only specific Cessna 400-series aircraft identified by model and serial number for a one-time structural modification."},"complexity_factors":["Single-page directive with no defined terms or interpretation section","One straightforward compliance requirement with no exceptions or conditional logic","Technical details delegated to external manufacturer document (Cessna Service Letter ME78-24)","Applicability determined by simple list of aircraft models and serial numbers"],"plain_english_summary":"**What this is:** An Airworthiness Directive (a mandatory safety order) requiring specific Cessna aircraft owners to modify the tail section of their planes.\n\n**Who it affects:** Owners and operators of specific twin-engine Cessna models (401, 411, 402, 404, 414, 421, and 441 series) with particular serial numbers—essentially older aircraft manufactured before certain dates.\n\n**What you must do:** Inspect and modify the **fuselage tailcone structure** (the rear section of the aircraft body) following the technical instructions in **Cessna Service Letter ME78-24**. This work must be completed within **100 hours of flying time** after 30 November 1978.\n\n**Why it matters:** This prevents potential structural failures in the tail section that could compromise flight safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-59-fuselage-tailcone-structure-modification","history":"/api/acts/ad-cessna-400-59-fuselage-tailcone-structure-modification/history","analysis":"/api/acts/ad-cessna-400-59-fuselage-tailcone-structure-modification/analysis","conflicts":"/api/acts/ad-cessna-400-59-fuselage-tailcone-structure-modification/conflicts","importantCases":"/api/acts/ad-cessna-400-59-fuselage-tailcone-structure-modification/important-cases","documents":"/api/acts/ad-cessna-400-59-fuselage-tailcone-structure-modification/documents"}}