{"id":"F2006B07579","name":"AD/VAT/5 - Control Column Torque Tube Bearing Spigots - Modification","slug":"ad-vat-5-control-column-torque-tube-bearing-spigots-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50200,"registerId":"commonwealth-F2006B07579-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/VAT/5 - Control Column Torque Tube Bearing Spigots - 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/5 Control Column Torque Tube Bearing\n\nSpigots - Modification\n\nApplicability: Victa Airtourer 100 and 115 with S/Nos. 1 to 16. Document:  Victa SB No. 6.\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\n3/63\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument applies specifically to Victa Airtourer 100 and 115 aircraft with serial numbers 1–16 and mandates a modification per Victa SB No. 6 to be completed before 1 September 1971 (see “Applicability”, “Document”, “Compliance”). There is no text in the supplied document indicating an expansion or narrowing of that scope from an earlier or different intent; the scope in the supplied text is narrow and fixed."},"complexity_factors":["Very short and specific directive: single modification requirement with a single, clear compliance deadline (see “Compliance”).","Narrow applicability: only Victa Airtourer 100 and 115 with serial numbers 1–16 are affected (see “Applicability”).","Technical detail is delegated to an external document (Victa SB No. 6), requiring access to that service bulletin for full instructions (see “Document”).","Compliance requires technical maintenance skills and parts availability, which adds operational complexity despite regulatory simplicity.","No exemptions, alternatives or enforcement procedures are set out in the text provided, leaving procedural detail to regulator practice or other instruments."],"plain_english_summary":"### What this directive does\n\nThis Airworthiness Directive (AD/VAT/5) requires a specific mechanical modification to the control column torque tube bearing spigots on certain Victa Airtourer aeroplanes. The AD identifies the affected aeroplanes, points to the service document that sets out the modification, and sets a hard deadline for compliance.\n\n- Requirement: Modify the control column torque tube bearing spigots (AD/VAT/5). (See heading and title.)\n- Which aircraft: Victa Airtourer 100 and 115, serial numbers 1 to 16. (See “Applicability”.)\n- How to do it: Follow Victa Service Bulletin No. 6. (See “Document”.)\n- When: The modification had to be completed before 1 September 1971. (See “Compliance”.)\n\n### Who is affected\n\n- Owners and operators of Victa Airtourer 100 and 115 aircraft with serial numbers 1–16 are directly affected. (See “Applicability”.)\n- Maintenance organisations or engineers who perform airframe modifications will carry out the work by following Victa SB No. 6. (See “Document”.)\n- The Civil Aviation Safety Authority (noted in the header) issues and enforces the AD.\n\n### Why it matters (what the instrument does mechanically and operationally)\n\n- Mechanically: it alters or upgrades the torque tube bearing spigots on the control column assembly. The AD itself specifies the requirement and points to the service bulletin for the technical steps. (See title and “Document”.)\n- Operationally: affected aircraft must receive the specified modification by the stated compliance date. That creates an obligation on owners/operators to arrange and pay for the work, and on maintenance providers to perform it according to the service bulletin.\n\n### Costs, incentives and trade-offs (based on the directive's mechanics)\n\n- Who pays: owners/operators of the specified aircraft must bear the direct costs of parts, labour and any associated downtime. (Implied by the mandatory compliance requirement and the listing of affected aircraft.)\n- Who decides: the regulator issues the mandatory requirement; owners decide how and when before the deadline to arrange the work; maintenance providers decide whether to offer the service and at what price. (See header and “Compliance”.)\n- Compliance burden: the AD imposes a clear compliance action and deadline (before 1 September 1971) and requires following an external service document (Victa SB No. 6). The technical nature of the task means the work will typically require qualified maintenance personnel and access to the service bulletin. (See “Document” and “Compliance”.)\n- Effects on private enterprise: maintenance and parts suppliers can perform the work and charge for it; market demand for that work is concentrated and limited to the small set of affected aircraft (S/N 1–16). The AD does not itself set prices or suppliers; it sets a mandatory specification to be followed. (See “Applicability” and “Document”.)\n- Implementation risk and opportunity cost: if parts, expertise, or documentation are scarce, owners may face delays or higher costs to comply. The AD gives no exemptions or alternatives in the text provided; compliance requires following the service bulletin. (See “Document” and “Compliance”.)\n\n### Practical implications and likely behaviour changes\n\n- Owners/operators will either arrange the modification before the compliance date or need to address regulatory consequences for non-compliance (the AD imposes the requirement). (See “Compliance”.)\n- Maintenance providers competent to perform the modification will be engaged to carry out the work to the specification in Victa SB No. 6. (See “Document”.)\n\nNote: The directive text supplied states the mechanical requirement, the affected models/serial numbers, the reference service document, and the compliance deadline. The text provided does not include an explicit statement of the problem or empirical rationale for the modification; the AD itself is the source of the mandatory action. (See entire AD text: heading, “Applicability”, “Document”, “Compliance”.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a historical Airworthiness Directive from 1963 (reference 3/63) with a compliance deadline of 1971. It represents the original scope of such safety directives — targeted, time-limited, and specific to particular aircraft serial numbers. There is no evidence of scope creep; it remains a narrow technical safety order."},"complexity_factors":["Extremely short document (approximately 100 words)","Only 4 operative provisions: applicability, document reference, compliance deadline, and subject matter","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: if you own this specific aircraft, you must do this specific thing by this specific date","Single technical reference to manufacturer service bulletin rather than detailed technical specifications within the instrument itself"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) requiring specific repairs or modifications to aircraft.\n\n**What it does:**\nOrders owners of specific Victa Airtourer aeroplanes to modify the **control column torque tube bearing spigots** (metal pins or projections that allow the control column to pivot smoothly). This is a mechanical fix to prevent potential control system failure.\n\n**Who it affects:**\n- Owners and operators of **Victa Airtourer 100 and 115** aircraft\n- Specifically those with **serial numbers 1 through 16** (early production models)\n\n**What must be done:**\n- Follow the instructions in **Victa Service Bulletin No. 6** (the manufacturer's official repair notice)\n- Complete the modification **before 1 September 1971**\n\n**Why it matters:**\nControl columns are what pilots use to steer the aircraft. If the bearing spigots fail, the pilot could lose control of the plane. This directive ensures a known mechanical defect in early-model aircraft is fixed before it causes an accident."}},"importantCases":[],"_links":{"self":"/api/acts/ad-vat-5-control-column-torque-tube-bearing-spigots-modification","history":"/api/acts/ad-vat-5-control-column-torque-tube-bearing-spigots-modification/history","analysis":"/api/acts/ad-vat-5-control-column-torque-tube-bearing-spigots-modification/analysis","conflicts":"/api/acts/ad-vat-5-control-column-torque-tube-bearing-spigots-modification/conflicts","importantCases":"/api/acts/ad-vat-5-control-column-torque-tube-bearing-spigots-modification/important-cases","documents":"/api/acts/ad-vat-5-control-column-torque-tube-bearing-spigots-modification/documents"}}