{"id":"F2006B07581","name":"AD/VAT/7 - Lower Tailplane Shroud - Modification","slug":"ad-vat-7-lower-tailplane-shroud-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50208,"registerId":"commonwealth-F2006B07581-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/VAT/7 - Lower Tailplane Shroud - 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)  Victa and A.E.S.L. Airtourer Series Aeroplanes\n\n \n\nAD/VAT/7 Lower Tailplane Shroud - Modification 5/63\n\nApplicability: Victa Airtourer 100 and 115 with S/Nos. 1 to 13. Document:  Victa SB No. 8.\n\nCompliance: Before 1 September 1971.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive, as written, sets a focused requirement: modify the lower tailplane shroud on Victa Airtourer 100 and 115 aircraft S/N 1–13 in accordance with Victa SB No. 8 by 1 September 1971. The text supplied contains no indication that the scope was expanded or narrowed beyond that original, specific applicability and requirement."},"complexity_factors":["Very narrow applicability (specific models and serial numbers specified in ‘Applicability’)","Single, time-limited compliance action (one modification with a single deadline in ‘Compliance’)","External dependence on a manufacturer service bulletin for the required method (Victa SB No. 8 referenced in ‘Document’)","Lack of procedural detail in the directive text (no exemptions, alternative compliance methods, or verification procedures stated)","Historic/vintage instrument dating to 1963/1971 increases contextual uncertainty but not statutory complexity"],"plain_english_summary":"This Airworthiness Directive (AD/VAT/7) mandates a modification to the lower tailplane shroud on Victa Airtourer 100 and 115 aircraft serials 1–13, to be carried out per Victa Service Bulletin No. 8 before 1 September 1971. Owners/operators must arrange and fund the work; the regulator enforces compliance. It imposes a short-term maintenance cost and downtime to address an unspecified airworthiness concern."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue Airworthiness Directive from 1963 (as indicated by the '5/63' suffix, meaning May 1963). It has not grown beyond its original purpose; it addresses one specific modification to one specific component on a limited production run of aircraft. The document appears complete and unaltered from its original intent."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","Only 4 operative elements: applicability (aircraft type + serial range), reference document (Service Bulletin No. 8), compliance deadline, and brief description of the modification","No defined terms section","No cross-references to other legislation or regulations beyond the enabling authority (Civil Aviation Regulations 1998, Part 39)","No conditional logic, exceptions, or nested provisions","Single, unambiguous compliance requirement with fixed deadline"],"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.\n\n**What it does:**\nIt requires owners and operators of specific Victa Airtourer aircraft to modify the \"lower tailplane shroud\" (a protective covering or fairing around the bottom part of the tailplane, which is the horizontal stabiliser at the rear of the plane).\n\n**Who it affects:**\n- **Aircraft:** Victa Airtourer 100 and 115 models\n- **Serial numbers:** Only aircraft with serial numbers 1 through 13 (the earliest production models)\n- **Operators:** Anyone flying or maintaining these specific aircraft\n\n**What must be done:**\nThe modification must be carried out following **Victa Service Bulletin No. 8** (the manufacturer's official technical instruction for this fix).\n\n**Deadline:**\nThe work had to be completed **before 1 September 1971**.\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. They are issued when a safety defect or unsafe condition is discovered in an aircraft type. Failing to comply means the aircraft cannot legally fly. This particular AD addressed a specific structural or aerodynamic issue with the tail section of early-model Airtourers that required a physical modification to ensure safe flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-vat-7-lower-tailplane-shroud-modification","history":"/api/acts/ad-vat-7-lower-tailplane-shroud-modification/history","analysis":"/api/acts/ad-vat-7-lower-tailplane-shroud-modification/analysis","conflicts":"/api/acts/ad-vat-7-lower-tailplane-shroud-modification/conflicts","importantCases":"/api/acts/ad-vat-7-lower-tailplane-shroud-modification/important-cases","documents":"/api/acts/ad-vat-7-lower-tailplane-shroud-modification/documents"}}