{"id":"F2006B06308","name":"AD/PR/1 - Pitch Lock Cylinder - Modification","slug":"ad-pr-1-pitch-lock-cylinder-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47423,"registerId":"commonwealth-F2006B06308-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PR/1 - Pitch Lock Cylinder - 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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Propellers - Variable Pitch - Dowty Rotol\n\n \n\nAD/PR/1 Pitch Lock Cylinder - Modification NK\n\nApplicability: All model (c) R193/4-30-4/50, (c) R184/4-30/4/50, (c) R179/4-20-4/33. Document: Dowty Rotol SB No. 61-231.\n\nCompliance: As detailed in the Requirement Document.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1500},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive addressing a specific mechanical defect in specific propeller models. It maintains its original narrow scope as a targeted safety mandate."},"complexity_factors":["Extremely narrow applicability (only 3 specific propeller part numbers)","Delegates all technical requirements to an external service bulletin (SB 61-231)","No conditional logic, exceptions, or definitions within the instrument itself","Single, straightforward compliance requirement"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by the Civil Aviation Safety Authority (CASA) that requires owners and operators to modify the **pitch lock cylinder** on specific aircraft propellers.\n\n**What it does:**\nThe directive mandates a mechanical modification to prevent failures in the propeller's pitch control system. The pitch lock cylinder is a component that stops propeller blades from changing their angle (pitch) unintentionally during flight.\n\n**Who it affects:**\nAnyone operating aircraft fitted with these specific Dowty Rotol propeller models:\n- (c) R193/4-30-4/50\n- (c) R184/4-30/4/50  \n- (c) R179/4-20-4/33\n\n**What must be done:**\nOperators must follow the technical instructions in **Dowty Rotol Service Bulletin No. 61-231** to perform the modification. This is not optional—non-compliance means the aircraft cannot legally fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pr-1-pitch-lock-cylinder-modification","history":"/api/acts/ad-pr-1-pitch-lock-cylinder-modification/history","analysis":"/api/acts/ad-pr-1-pitch-lock-cylinder-modification/analysis","conflicts":"/api/acts/ad-pr-1-pitch-lock-cylinder-modification/conflicts","importantCases":"/api/acts/ad-pr-1-pitch-lock-cylinder-modification/important-cases","documents":"/api/acts/ad-pr-1-pitch-lock-cylinder-modification/documents"}}