{"id":"F2006B07594","name":"AD/VW/3 - Rear Bearing","slug":"ad-vw-3-rear-bearing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50253,"registerId":"commonwealth-F2006B07594-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/VW/3 - Rear Bearing","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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Volkswagen Derivative Piston Engines\n\n \n\nAD/VW/3 Rear Bearing 8/88\n\nApplicability: Revmaster R2100 series engines.\n\n \n\nRequirement: Modify the No 1 main bearing (rear) by providing a locating dowel for both bearing halves.\n\nCompliance: Unless already accomplished, at next disassembly of the crankcase assembly. Background:               This Directive has been issued to reflect the requirements of cancelled Airworthiness\n\nDirective ANO 106 AD/REV/3.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\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 AD restates and reflects requirements of a previously cancelled directive (Background) and does not indicate any expansion of applicability or additional requirements beyond installing locating dowels on the No. 1 main bearing for Revmaster R2100 engines and timing the work at next crankcase disassembly (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow applicability: limited to Revmaster R2100 series engines (Applicability).","Single, well-defined technical action: install locating dowel to both bearing halves (Requirement).","Clear, time-flexible compliance trigger: at next crankcase disassembly rather than immediate action (Compliance).","Low regulatory-document complexity: short text with one requirement and an administrative background note (Requirement; Background).","Practical implementation factors: mechanical installation requires parts, tooling and qualified maintenance personnel even though not described in detail (Requirement)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators and maintenance providers of Revmaster R2100 piston engines to fit locating dowels to both halves of the No. 1 (rear) main bearing. The modification must be completed at the next crankcase disassembly if not already done.\n\nIt replaces a cancelled AD administratively; the one‑off mechanical change imposes parts and labour costs on the owner/operator but can be scheduled with routine maintenance rather than forcing immediate grounding."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a straightforward technical maintenance requirement for a specific engine type. It has not expanded beyond its original purpose of ensuring proper bearing retention in Revmaster engines."},"complexity_factors":["Extremely short document (under 150 words)","Only one substantive requirement with a single condition","No defined terms section","No cross-references to other legislation (only references a cancelled predecessor directive)","Simple temporal trigger for compliance ('at next disassembly')","Single applicability criterion (one engine series)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to a specific type of aircraft engine: the **Revmaster R2100 series**.\n\n**What it requires:**\nOwners or operators of these engines must modify the rear main bearing (called the \"No 1 main bearing\") by adding a locating dowel to both halves of that bearing. A \"dowel\" is a small metal pin that keeps parts properly aligned and prevents them from shifting.\n\n**When to do it:**\nThe modification must be done at the next time the engine's crankcase is taken apart for maintenance, unless it has already been done.\n\n**Why it matters:**\nThis directive replaces an older safety order (ANO 106 AD/REV/3) that was cancelled. The change ensures the rear bearing stays properly positioned, which is critical for engine reliability and flight safety. If the bearing shifts, it could cause engine failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-vw-3-rear-bearing","history":"/api/acts/ad-vw-3-rear-bearing/history","analysis":"/api/acts/ad-vw-3-rear-bearing/analysis","conflicts":"/api/acts/ad-vw-3-rear-bearing/conflicts","importantCases":"/api/acts/ad-vw-3-rear-bearing/important-cases","documents":"/api/acts/ad-vw-3-rear-bearing/documents"}}