{"id":"F2006B06156","name":"AD/PC-6/6 - Tail Plane - Modification","slug":"ad-pc-6-6-tail-plane-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46964,"registerId":"commonwealth-F2006B06156-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-6/6 - Tail Plane - 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)  Pilatus Porter PC-6 Series Aeroplanes\n\n \n\nAD/PC-6/6 Tail Plane - Modification 3/66\n\nApplicability: All models with S/Nos. 1 to 580. Document:  Pilatus SB No. 27A. Compliance:  Before 15 April 1966.\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 historical Airworthiness Directive from 1966 (indicated by '3/66' in the reference). It remains within its original scope as a specific safety mandate for a particular aircraft type and serial number range. There is no evidence of scope creep — it does exactly what it says on the tin: mandates a tail plane modification for early-model Pilatus PC-6 aircraft."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","No defined terms section — uses plain aviation terminology","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Simple conditional structure: single applicability criterion (serial numbers 1-580) and single compliance deadline","No exceptions, exemptions, or nested conditions","Single operational requirement: comply with manufacturer's Service Bulletin before specified date"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for a specific type of aircraft.\n\n**What it does:**\n- Requires owners/operators of **Pilatus Porter PC-6 series aeroplanes** (specifically those with serial numbers 1 to 580) to modify the **tail plane** (the horizontal stabiliser at the rear of the aircraft that helps control pitch).\n\n**Who it affects:**\n- Anyone who owns or operates a Pilatus PC-6 aircraft with serial numbers 1 through 580.\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety instructions. If you don't comply by the deadline (**15 April 1966**), you cannot legally fly the aircraft. This particular directive references a **Service Bulletin (SB No. 27A)** from the manufacturer (Pilatus), which contains the technical details of the required modification.\n\n**Key details:**\n- **Document reference:** AD/PC-6/6 (the 6th AD issued for the PC-6 type)\n- **Compliance deadline:** Before 15 April 1966\n- **Source document:** Pilatus Service Bulletin No. 27A (this tells mechanics exactly what work to do)"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The document, as provided, sets the scope explicitly: all Pilatus PC-6 aeroplanes with serial numbers 1–580 are required to receive the tail‑plane modification specified in Pilatus SB No. 27A by 15 April 1966. The text contains no indication that the scope was expanded or reduced from an earlier instrument; therefore there is no evidence in this text of a change from the original scope."},"complexity_factors":["Narrow, specific applicability limited to PC-6 serial numbers 1–580","Single mandatory action defined by reference to an external technical document (Pilatus SB No. 27A)","Clear, single compliance deadline (Before 15 April 1966)","AD text contains no procedural detail, exemptions, alternative compliance procedures or enforcement language — reliance on external SB increases operational dependence on manufacturer documentation","No explanatory or evidentiary material in the text to clarify rationale or risk assessment"],"plain_english_summary":"This AD mandates a tail‑plane modification for all Pilatus PC‑6 aeroplanes S/N 1–580, to be carried out per Pilatus Service Bulletin No. 27A by 15 April 1966. Owners/operators must schedule, fund and complete the work.\n\nBy referencing the service bulletin, the directive makes the manufacturer’s technical instructions legally binding, creating a safety‑driven compliance, downtime and cost burden despite the AD itself not stating the technical steps or rationale."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-6-6-tail-plane-modification","history":"/api/acts/ad-pc-6-6-tail-plane-modification/history","analysis":"/api/acts/ad-pc-6-6-tail-plane-modification/analysis","conflicts":"/api/acts/ad-pc-6-6-tail-plane-modification/conflicts","importantCases":"/api/acts/ad-pc-6-6-tail-plane-modification/important-cases","documents":"/api/acts/ad-pc-6-6-tail-plane-modification/documents"}}