{"id":"F2006B06335","name":"AD/PR/7 - Operating Cylinder - Replacement","slug":"ad-pr-7-operating-cylinder-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47513,"registerId":"commonwealth-F2006B06335-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PR/7 - Operating Cylinder - Replacement","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/7 Operating Cylinder - Replacement NK\n\nApplicability: All models detailed in SB No. 61-564 not incorporating Mod. No. (c) VP 2422 (SB 61-540).\n\n \n\nDocument: Dowty Rotol SB No. 61-564. (Mod. No. (c) VP 2480). Compliance: Before 1 January 1970.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\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 discrete, single-issue Airworthiness Directive from 1970 addressing a specific mechanical defect or wear issue in Dowty Rotol propeller operating cylinders. It has not expanded beyond its original narrow technical scope."},"complexity_factors":["Single, specific mechanical component requirement (operating cylinder replacement)","Limited applicability scope (specific propeller models from one manufacturer)","Single compliance condition (deadline-based, not flight hours or cycles)","One exemption criterion (pre-existing modification VP 2422)","No nested definitions or cross-references to other legislation","Document relies on external technical reference (Service Bulletin) rather than spelling out technical details in the legislative text itself"],"plain_english_summary":"This is a **Civil Aviation Safety Authority (CASA) Airworthiness Directive** — essentially a mandatory safety order for aircraft.\n\n**What it does:**\nRequires the **replacement of operating cylinders** on certain Dowty Rotol variable-pitch propellers.\n\n**Who it affects:**\nOwners and operators of aircraft fitted with Dowty Rotol propellers that match the models listed in Service Bulletin No. 61-564, **unless** those propellers already have Modification No. VP 2422 installed (as detailed in Service Bulletin 61-540).\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If this applies to your aircraft, you **must** replace the operating cylinder before 1 January 1970 to keep the aircraft legally airworthy. Flying without complying could ground the aircraft or create safety risks.\n\n**Key details:**\n- **Compliance deadline:** Before 1 January 1970\n- **Technical reference:** Dowty Rotol Service Bulletin No. 61-564 (which references Modification No. VP 2480)\n- **Exemption:** Propellers with Mod. VP 2422 already installed are exempt"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument retains a narrowly targeted operative scope: it mandates replacement of the operating cylinder for the propeller models listed in Dowty Rotol SB No. 61-564, except where Mod. No. (c) VP 2422 has already been incorporated. The requirement is tied to the referenced service bulletin and a fixed compliance date (before 1 January 1970). The text does not expand or contract that scope beyond these stated conditions."},"complexity_factors":["Narrow, specific technical scope limited to propellers listed in a single service bulletin (reduces breadth). (Applicability)","Cross-reference dependence on external manufacturer service bulletin for procedural detail (requires locating and following SB No. 61-564). (Document)","A single hard compliance deadline creates scheduling pressure but simplifies legal analysis (Compliance)","Exemption tied to a specific modification (VP 2422) requires verification of modification status for each propeller. (Applicability)","Lack of alternative compliance or administrative detail in the AD itself shifts implementation complexity to operators and maintenance organisations. (Document)"],"plain_english_summary":"This directive mandates replacing the operating cylinder on specific Dowty Rotol variable‑pitch propellers identified in manufacturer SB No. 61‑564, unless the propeller already has Mod. No. (c) VP 2422. Affected aircraft owners/operators must arrange and pay for the work, carried out by licensed maintenance providers per the service bulletin, and complete it by 1 January 1970."},"summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a standalone directive imposing a one-off replacement requirement; it does not amend any other legislative instrument."},"complexity_factors":["Very short directive text","Single replacement action specified","Compliance deadline is in the distant past"],"plain_english_summary":"This airworthiness directive (AD/PR/7) applies to specific Dowty Rotol variable pitch propellers. It requires replacement of the operating cylinder as detailed in Dowty Rotol Service Bulletin No. 61-564 (Modification No. (c) VP 2480). The work must be completed before 1 January 1970. The directive covers all propeller models listed in that service bulletin that have not already incorporated Modification No. (c) VP 2422 (per Service Bulletin 61-540). Because the compliance deadline was over 50 years ago, this AD is now historical. However, any affected propeller that was not modified by that date would not meet the airworthiness requirement. Aircraft owners, operators and maintenance organisations dealing with older aircraft equipped with these propellers should check the modification status to ensure continued compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pr-7-operating-cylinder-replacement","history":"/api/acts/ad-pr-7-operating-cylinder-replacement/history","analysis":"/api/acts/ad-pr-7-operating-cylinder-replacement/analysis","conflicts":"/api/acts/ad-pr-7-operating-cylinder-replacement/conflicts","importantCases":"/api/acts/ad-pr-7-operating-cylinder-replacement/important-cases","documents":"/api/acts/ad-pr-7-operating-cylinder-replacement/documents"}}