{"id":"F2006B08329","name":"AD/CESSNA 400/43 Amdt 8 - Engine Exhaust System","slug":"ad-cessna-400-43-amdt-8-engine-exhaust-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115736,"registerId":"commonwealth-F2006B08329-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/43 Amdt 8 - Engine Exhaust System","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 400 Series Aeroplanes\n\nAD/CESSNA 400/43\n\nAmdt 8\n\n  \nEngine Exhaust System 13/97\n\nApplicabilility: All model 401, 401A, 401B,402,402A,402B,414,414A,421,421A and 421B series aeroplanes.\n\nRequirement: 1. Inspect applicable aircraft engine exhaust system assemblies in accordance with the provisions of Cessna SIL ME75-17 and Cessna SIL ME79-32.\n\n    2. Inspect exhaust system components in accordance with the provisions of Table II of Cessna SIL No. ME79-32.\n\n    3. Replace multi-segment ‘V’ band exhaust clamps listed in Table III of Cessna SIL No. ME79-32.\n\nNote: FAA AD 75-23-08 R5 Amdt 39-5451 refers.\n\nCompliance: 1. At intervals not exceeding 50 hours time in service.\n\n    2. At intervals not exceeding 100 hours time in service.\n\n    3. At intervals not exceeding 750 hours time in service.\n\nThis airworthiness directive becomes effective on 4 December 1997.\n\nBackground: This amendment deletes the 421C series aeroplane from the AD applicability. This model aircraft has a modified exhaust system which is not subject to the defects addressed by this directive.\n\nAmendment 7 of this airworthiness directive became effective on 20 August 1992. Amendment 6 of this airworthiness directive became effective on 12 March 1987. The original issue of this airworthiness directive became effective on 31 March 1975.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment narrowed the AD's scope by removing the 421C series from applicability because that model has a modified exhaust system not subject to the addressed defects; earlier versions applied to the 421C. Compliance tasks and intervals remain the operative obligations for the retained models."},"complexity_factors":["Cross-references several Cessna Service Instructions (SIL ME75-17, ME79-32) which require consulting external documents to determine exact procedures and part lists.","Different mandatory compliance intervals for different tasks (50, 100 and 750 hours) increase maintenance scheduling complexity.","Multiple aircraft models covered (401, 401A/B, 402, 402A/B, 414/414A, 421/421A/421B) require fleet-specific applicability checks.","Specific part replacement requirement (multi-segment ‘V’ band clamps listed in Table III of SIL ME79-32) creates reliance on parts availability and correct identification.","Amendment history and a change in applicability (421C excluded) require maintainers to track versions to determine current obligations.","Low administrative discretion: compliance is mandatory, limiting operator choice about inspection frequency and replacement timing."],"plain_english_summary":"This airworthiness directive mandates that operators of specified Cessna 400/401/402/414/421 series aeroplanes inspect engine exhaust assemblies and certain components and replace listed multi‑segment ‘V’‑band exhaust clamps in accordance with the cited Cessna Service Instructions. Inspections are required at 50‑ or 100‑hour intervals depending on the task, and clamp replacement at 750 hours. The directive binds aircraft owners/operators and maintenance providers, who pay for inspections, parts and scheduling; it narrows applicability by excluding the 421C because that model has a modified exhaust."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"This amendment narrows the scope by removing the Cessna 421C series from applicability. The original 1975 directive covered all 400 series aircraft, but this version explicitly excludes the 421C because its modified exhaust system doesn't suffer from the defects addressed. This is a scope reduction rather than expansion."},"complexity_factors":["Very short document (under 300 words)","Only 3 defined compliance intervals (50, 100, 750 hours)","References external technical documents (Cessna Service Information Letters) rather than reproducing requirements in full","Simple conditional logic: if you operate this aircraft model, you must do these three things","No nested exceptions or cross-references to other legislation beyond a single note about the corresponding FAA directive","Single amendment purpose clearly stated in Background section"],"plain_english_summary":"This safety order requires regular inspections and periodic clamp replacement of engine exhaust systems on specified Cessna twin‑engine models to prevent carbon monoxide leaks and engine fires. It affects owners, operators, and maintenance organisations of the listed aircraft. The latest corrective amendment narrows the rule by removing the 421C—whose redesigned exhaust no longer shares the safety issue—while continuing scheduled checks for the remaining models."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-43-amdt-8-engine-exhaust-system","history":"/api/acts/ad-cessna-400-43-amdt-8-engine-exhaust-system/history","analysis":"/api/acts/ad-cessna-400-43-amdt-8-engine-exhaust-system/analysis","conflicts":"/api/acts/ad-cessna-400-43-amdt-8-engine-exhaust-system/conflicts","importantCases":"/api/acts/ad-cessna-400-43-amdt-8-engine-exhaust-system/important-cases","documents":"/api/acts/ad-cessna-400-43-amdt-8-engine-exhaust-system/documents"}}