{"id":"F2006B06333","name":"AD/PR/4 - Application of Pre-Primer to Propeller Blades","slug":"ad-pr-4-application-of-pre-primer-to-propeller-blades","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47506,"registerId":"commonwealth-F2006B06333-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PR/4 - Application of Pre-Primer to Propeller Blades","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/4 Application of Pre-Primer to Propeller Blades NK\n\nApplicability: As detailed in the requirement document.\n\n \n\nDocument: Dowty Rotol SB No. 61-157 (Mod. No. (c) VP 1941).\n\n \n\nCompliance: Before installation in an aircraft following next overhaul completed after 28 February 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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text does not indicate any change in scope from the original intent. It prescribes a single mandatory action (application of pre-primer) for the propellers identified in the external requirement document and specifies the technical source (Dowty Rotol SB No. 61-157) and a compliance timing trigger (installation after the next overhaul completed after 28 February 1966). No amendment or narrowing/broadening of scope is stated in the provided text."},"complexity_factors":["Short, narrowly framed requirement: single action (apply pre-primer) with a single timing condition (before installation after next overhaul).","Reliance on two external documents for scope and technical detail: \"requirement document\" (for applicability) and Dowty Rotol SB No. 61-157 (for method).","Ambiguous applicability in this text: \"As detailed in the requirement document\" shifts key scope determination outside the instrument.","No procedural or enforcement detail in the text (no record-keeping, inspection, or penalty provisions), increasing practical uncertainty despite substantive simplicity.","Historic compliance trigger date (28 February 1966) may create interpretive or archival issues for implementers referencing legacy overhauls and records."],"plain_english_summary":"This instrument requires that specified Dowty Rotol variable‑pitch propeller blades receive a “pre‑primer” per Dowty Rotol SB No. 61‑157 (Mod. No. (c) VP 1941) before being fitted to an aircraft after their next overhaul completed after 28 February 1966. It applies to blades identified in the external requirement document, obliges maintenance organisations/operators to follow the service bulletin, and shifts material and labour costs to whoever performs the overhaul. The directive delegates scope and technical detail to the cited external documents and is silent on verification/enforcement."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be the original scope of the directive. It is a discrete, single-issue safety directive addressing a specific manufacturing defect or maintenance requirement for one propeller manufacturer. There is no evidence of scope creep or expansion beyond the original technical purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 1 defined term implicitly referenced (the Service Bulletin)","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Simple conditional logic: single trigger event (overhaul after specific date) leading to single action (apply pre-primer before installation)","No nested exceptions or conditional sub-clauses","Clear, unambiguous applicability clause referencing external technical document"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998. It mandates a specific safety modification for certain aircraft propellers.\n\n**What it does:**\n- Requires the application of a \"pre-primer\" (a preparatory coating) to propeller blades made by Dowty Rotol (a specific manufacturer)\n- The work must be done according to the manufacturer's Service Bulletin No. 61-157\n\n**Who it affects:**\n- Owners and operators of aircraft with **Dowty Rotol variable-pitch propellers**\n- Specifically those propellers being overhauled and reinstalled in aircraft\n\n**When it applies:**\n- **Before** any affected propeller can be installed in an aircraft\n- Only if the propeller's **next overhaul after 28 February 1966** has been completed\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety orders. This one addresses a specific corrosion or adhesion issue with propeller blades that required a manufacturing process change (applying a pre-primer coating). Non-compliance means the propeller cannot legally be fitted to an aircraft, keeping unsafe equipment out of the sky."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pr-4-application-of-pre-primer-to-propeller-blades","history":"/api/acts/ad-pr-4-application-of-pre-primer-to-propeller-blades/history","analysis":"/api/acts/ad-pr-4-application-of-pre-primer-to-propeller-blades/analysis","conflicts":"/api/acts/ad-pr-4-application-of-pre-primer-to-propeller-blades/conflicts","importantCases":"/api/acts/ad-pr-4-application-of-pre-primer-to-propeller-blades/important-cases","documents":"/api/acts/ad-pr-4-application-of-pre-primer-to-propeller-blades/documents"}}