{"id":"F2006B09035","name":"AD/DHC-2/18 - Tailplane Rear Spar - Inspection and Modification","slug":"ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52732,"registerId":"commonwealth-F2006B09035-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-2/18 - Tailplane Rear Spar - Inspection and 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)  DHC-2 (Beaver) Series Aeroplanes\n\n \n\nAD/DHC-2/18 Tailplane Rear Spar - Inspection and Modification 7/77\n\nApplicability: All models.\n\n \n\nDocument: De Havilland Aircraft of Canada SB No. 2/19.\n\n \n\nCompliance: Initially inspect within 25 hours time in service after 8 July 1977 and thereafter as per requirement document.\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\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 a discrete, single-issue airworthiness directive focused specifically on the DHC-2 Beaver tailplane rear spar. It has not expanded beyond its original safety purpose. The document appears to be a historical directive from 1977 (as indicated by '7/77' in the reference number), and its scope remains tightly confined to the specific inspection and modification requirement originally intended."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 1 defined term implicitly referenced (the Service Bulletin)","No cross-references to other legislation beyond the enabling regulation (CAR 1998, Part 39)","Simple conditional structure: single compliance deadline plus ongoing requirement","No exceptions, exemptions, or nested conditions","Single applicability criterion ('All models')","Relies entirely on external technical document (Service Bulletin) for substantive detail"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nIt requires owners and operators of **De Havilland DHC-2 \"Beaver\" aircraft** to inspect and modify the **tailplane rear spar** (a critical structural component at the back of the plane that helps control pitch and stability).\n\n**Who it affects:**\n- All owners and operators of DHC-2 Beaver series aeroplanes in Australia\n- Maintenance engineers working on these aircraft\n\n**What must be done:**\n- **Initial inspection:** Must be completed within 25 hours of flying time after 8 July 1977\n- **Ongoing compliance:** Follow the requirements in **De Havilland Service Bulletin No. 2/19** (the manufacturer's official technical instruction)\n\n**Why it matters:**\nAirworthiness Directives are legally enforceable safety mandates. Failure to comply means the aircraft cannot legally fly. This particular AD addresses potential structural defects in the tail section that could affect flight safety if left unaddressed."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text supplied sets the directive's scope as applying to all DHC-2 models and requires an initial inspection within 25 hours followed by actions in the referenced service bulletin. There is no information in the instrument itself indicating a change from an earlier or different scope; therefore there is no evidence in this text that the scope has changed from any original intent."},"complexity_factors":["References an external technical document (De Havilland SB No. 2/19) for procedural detail rather than including procedures in the AD itself, requiring access to and interpretation of that document.","Short, fixed initial compliance window (25 hours time in service after 8 July 1977) creates scheduling pressure for operators.","Scope is broad in applicability (all DHC-2 models) but vague as to what constitutes a required modification or the repeat intervals (delegated to the requirement document).","Enforcement and technical judgement depend on two layers (CASA authority and manufacturer service bulletin), creating potential coordination and interpretation needs between regulator, owner/operator and maintenance providers."],"plain_english_summary":"This airworthiness directive requires every De Havilland DHC‑2 (Beaver) operator to inspect the tailplane rear spar within 25 hours TIS after 8 July 1977 and to carry out any required modification and ongoing inspections per De Havilland Service Bulletin No. 2/19. Compliance is the owner/operator’s legal responsibility, enforced by CASA under the Civil Aviation Regulations, and may cause near‑term downtime, inspection and modification costs charged by maintenance providers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification","history":"/api/acts/ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification/history","analysis":"/api/acts/ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification/analysis","conflicts":"/api/acts/ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification/important-cases","documents":"/api/acts/ad-dhc-2-18-tailplane-rear-spar-inspection-and-modification/documents"}}