{"id":"F2006B04168","name":"AD/BEECH 76/10 Amdt 2 - Engine Mount Support Structure","slug":"ad-beech-76-10-amdt-2-engine-mount-support-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43921,"registerId":"commonwealth-F2006B04168-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 76/10 Amdt 2 - Engine Mount Support Structure","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)  Beechcraft 76 (Duchess) Series Aeroplanes\n\n \n\n# AD/BEECH 76/10\n\nAmdt 2\n\nApplicability: All models.\n\n# Engine Mount Support Structure 2/91\n\n \n\nRequirement: Visually inspect the engine mount channels P/Nos. 105-980000 -19, -21, -23, -25 for cracks in the area adjacent to the anchor nut securing the engine mount bolt.\n\n \n\nNote 1: If mount channel is cracked, visually inspect the associated keel and structure for cracks and structural distress.\n\n \n\nNote 2: Defective mount channels and associated structure are to be repaired to a scheme acceptable to the Authority.\n\n \n\nNote 3: Beechcraft SB No 2018 introduces a kit to provide inspection plates to facilitate the engine mount/nacelle channel inspection.\n\n \n\nCompliance: Within 100 hours’ time in service after 30 April 1984, or at the next scheduled inspection for Maintenance Release issue after 30 April 1984, whichever occurs first and thereafter at intervals not exceeding 100 hours’ time in service.\n\n \n\nBackground: This Directive was raised in issue to include a recurring inspection due to reports of engine mount channel failure. Further defects have been reported since the initial one time inspection.\n\n \n\nThis amendment introduces SB No 2018 which supersedes and cancels Beechcraft Service Instruction No 1237.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing Airworthiness Directive. The amendment simply updates the referenced service bulletin (replacing Service Instruction No 1237 with SB No 2018) to provide better access for inspections. The core safety purpose — recurring inspection of engine mount channels — remains unchanged from the original 1984 directive."},"complexity_factors":["Single, specific mechanical component targeted (engine mount channels with 4 specific part numbers)","Straightforward inspection requirement with clear time intervals (100 hours)","Only 3 brief notes providing supplementary guidance","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1988","No conditional logic or nested exceptions — applies to 'All models' uniformly","Total length is approximately 250 words","Clear compliance deadline with simple 'whichever occurs first' formulation"],"plain_english_summary":"This CASA Airworthiness Directive orders owners and operators of Beechcraft 76 \"Duchess\" aircraft in Australia to inspect the engine-to-wing mount channels for cracks, initially within a short deadline and then every 100 flight hours. \n\nIf cracks are found, surrounding structure must be checked and defective parts repaired using CASA‑approved methods. The rule prevents catastrophic engine separation after repeated reports of mounting failures."},"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":4,"scope_assessment":{"changed":true,"description":"Scope was expanded from the initial one‑time inspection to a recurring inspection program and incorporation of a Beechcraft service bulletin kit. The Background states the Directive was raised to include a recurring inspection due to further reports of mount channel failure (Background), and the amendment introduces SB No 2018 which supersedes Service Instruction No 1237 (amendment statement)."},"complexity_factors":["Technical specificity of affected components (engine mount channels P/N 105-980000-19, -21, -23, -25) increases need for qualified maintenance and correct part identification (Requirement).","Recurring inspection interval tied to flight hours and maintenance-release scheduling creates an ongoing compliance burden for operators (Compliance).","Repair obligation requires an approval scheme acceptable to the Authority, introducing bureaucratic discretion and potential processing time/costs (Note 2).","If cracks are found, mandatory follow-up inspection of associated keel/structure expands scope of work and potential repair complexity (Note 1).","Introduction of Beechcraft SB No 2018 and cancellation of Service Instruction No 1237 imposes document/parts-upgrade management on operators and maintenance organisations (Note 3; amendment statement).","Applicability to all models broadens affected population and reduces exemption complexity (Applicability).","Integration with existing maintenance-release processes (Compliance) requires coordination between scheduled inspections and AD timing."],"plain_english_summary":"This Directive requires owners/operators of all Beechcraft 76 (Duchess) aircraft to visually inspect engine mount channels P/N 105-980000‑19, -21, -23, -25 for cracks adjacent to the anchor nut, and to inspect/repair associated keel structure if cracks are found. Compliance is within 100 hours’ time‑in‑service after 30 April 1984 or at the next maintenance‑release inspection, and thereafter every 100 hours. Repairs must follow a scheme acceptable to the Civil Aviation Safety Authority; Beechcraft SB No 2018 supplies inspection plates and supersedes Service Instruction No 1237. Costs fall to operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-76-10-amdt-2-engine-mount-support-structure","history":"/api/acts/ad-beech-76-10-amdt-2-engine-mount-support-structure/history","analysis":"/api/acts/ad-beech-76-10-amdt-2-engine-mount-support-structure/analysis","conflicts":"/api/acts/ad-beech-76-10-amdt-2-engine-mount-support-structure/conflicts","importantCases":"/api/acts/ad-beech-76-10-amdt-2-engine-mount-support-structure/important-cases","documents":"/api/acts/ad-beech-76-10-amdt-2-engine-mount-support-structure/documents"}}