{"id":"F2006B07554","name":"AD/VAT/21 - Fuel Tank Retention Buttons - Modification","slug":"ad-vat-21-fuel-tank-retention-buttons-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50148,"registerId":"commonwealth-F2006B07554-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/VAT/21 - Fuel Tank Retention Buttons - 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/21 Fuel Tank Retention Buttons - Modification 11/64\n\nApplicability: Victa Airtourer 100 and 115 with S/Nos. 1 to 75. Document:  Victa SB No. 44.\n\nCompliance: Within 100 hours time in service after 20 November 1964.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1964. It has not expanded beyond its original narrow purpose of addressing a specific mechanical defect in specific aircraft."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","No defined terms section","No cross-references to other legislation (only references a service bulletin)","Simple conditional logic: if you own this specific aircraft, you must do this specific action by this deadline","Single compliance requirement with clear applicability criteria (specific model and serial number range)","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft instead of cars.\n\n**What it requires:** Owners or operators of specific **Victa Airtourer 100 and 115 aeroplanes** (serial numbers 1 to 75) must modify the **fuel tank retention buttons** — the parts that hold the fuel tanks in place. The modification must follow the instructions in **Victa Service Bulletin No. 44**.\n\n**When it must be done:** Within **100 hours of flying time** after **20 November 1964**.\n\n**Why it matters:** Fuel tank retention buttons are critical safety components. If they fail, fuel tanks could detach or leak — potentially causing fire, engine failure, or loss of control. This AD ensures older Airtourer aircraft receive a necessary safety fix before the problem causes an accident.\n\n**Who is affected:** Anyone operating the specific Victa Airtourer models listed (a light, single-engine aircraft popular in Australia for training and private flying)."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive as provided sets a narrow, specific requirement (modification per Victa SB No. 44) for a defined subset of aircraft (Airtourer 100 and 115, S/N 1–75) with a clear compliance deadline (within 100 hours after 20 November 1964). There is no information in the text indicating a change from an earlier or original scope."},"complexity_factors":["Narrow technical scope: applies only to Victa Airtourer 100 and 115 with serial numbers 1–75 (Applicability).","Single, specified means of compliance: requires following Victa Service Bulletin No. 44 (Document), which is technical in nature.","Defined and short compliance window: within 100 hours time in service after a specific date (Compliance).","Implied operational burden on owners/operators to arrange qualified maintenance and bear costs (Document; Compliance).","Limited procedural detail in the text about alternative compliance or enforcement, leaving implementation and discretionary approvals to the administering authority (Document; Compliance — implied)."],"plain_english_summary":"This airworthiness directive requires owners/operators of Victa (A.E.S.L.) Airtourer 100 and 115 aircraft (serial nos. 1–75) to have the fuel tank retention buttons modified per Victa Service Bulletin No. 44 within 100 hours time-in-service after 20 November 1964. Costs, scheduling and documentation of the mandated work fall to the aircraft owners/operators to retain airworthiness."}},"importantCases":[],"_links":{"self":"/api/acts/ad-vat-21-fuel-tank-retention-buttons-modification","history":"/api/acts/ad-vat-21-fuel-tank-retention-buttons-modification/history","analysis":"/api/acts/ad-vat-21-fuel-tank-retention-buttons-modification/analysis","conflicts":"/api/acts/ad-vat-21-fuel-tank-retention-buttons-modification/conflicts","importantCases":"/api/acts/ad-vat-21-fuel-tank-retention-buttons-modification/important-cases","documents":"/api/acts/ad-vat-21-fuel-tank-retention-buttons-modification/documents"}}