{"id":"F2006B04889","name":"AD/CASA/9 - Engine Controls - Propeller Feathering System","slug":"ad-casa-9-engine-controls-propeller-feathering-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44696,"registerId":"commonwealth-F2006B04889-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CASA/9 - Engine Controls - Propeller Feathering System","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)  Casa 212 Series Aeroplanes\n\n \n\nAD/CASA/9 Engine Controls - Propeller Feathering System 6/87\n\nApplicability: All model CASA-212 with S/No’s referenced in the Requirement Document. Requirement:               Action in accordance with CASA S.B. No. 212-76-04.\n\nNote: FAA AD No. 87-05-06 Amendment 39-5561 also refers.\n\n \n\nCompliance: Modify prior to 31 December 1987.\n\n \n\nBackground:  The possibility of loss of propeller control system integrity is not sufficiently remote for this class of aeroplane.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\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, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating a propeller system modification."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly referenced (the Service Bulletin)","No nested conditional logic or exceptions","Single straightforward requirement: comply with external technical document","Clear applicability criteria (specific aircraft model and serial numbers)","Simple compliance deadline (fixed date)","No cross-references to other legislation beyond a related FAA directive mentioned in a note"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA).\n\n**What it does:**\nIt requires owners and operators of specific CASA-212 series aircraft to modify their **propeller feathering system** (the mechanism that allows pilots to stop a propeller from spinning and angle its blades to reduce drag, typically used during engine failure).\n\n**Who it affects:**\n- Owners and operators of CASA-212 aircraft with specific serial numbers listed in CASA Service Bulletin 212-76-04\n- This is a Spanish-built twin-turboprop aircraft used for transport, skydiving, and military purposes\n\n**What must be done:**\n- Aircraft must be modified according to the technical instructions in **CASA Service Bulletin 212-76-04**\n- The work had to be completed before **31 December 1987**\n\n**Why it matters:**\nThe safety risk was that the propeller control system could fail, potentially causing loss of control over the propeller during flight. This could lead to dangerous situations like uncontrolled propeller rotation or inability to feather the propeller during engine failure, increasing drag and making the aircraft harder to control.\n\n**Key point:** This is a **time-critical safety mandate** — not optional. Non-compliance would make the aircraft unairworthy (illegal to fly)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The source text sets a requirement for modification of specified CASA-212 aircraft and specifies the service bulletin and compliance date. There is no indication within this text that the applicability or required actions differ from the directive's stated purpose: to address insufficiently remote risk of loss of propeller control system integrity (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Reference to external documents required for compliance (Requirement: CASA S.B. No. 212-76-04; Requirement Document listing serial numbers)","Technical nature of the required modification (propeller feathering system) requiring licensed maintenance personnel and parts","Fixed compliance deadline requiring scheduling and possible operational disruption (Compliance: modify prior to 31 December 1987)","Cross-reference to a foreign regulator's AD (FAA AD No. 87-05-06), which may require alignment or additional checks","The AD text omits detailed procedures and the serial-number list, forcing reliance on other documents"],"plain_english_summary":"This Airworthiness Directive mandates modification of the propeller feathering system on specified CASA‑212 airframes, to be carried out per CASA Service Bulletin No. 212‑76‑04 and completed by 31 December 1987. It addresses an identified risk to propeller control integrity and notes alignment with FAA AD No. 87‑05‑06.\n\nThe AD affects owners/operators of the listed serial‑number aircraft and the maintenance organisations that must perform the work; operators are responsible for costs, scheduling and compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-casa-9-engine-controls-propeller-feathering-system","history":"/api/acts/ad-casa-9-engine-controls-propeller-feathering-system/history","analysis":"/api/acts/ad-casa-9-engine-controls-propeller-feathering-system/analysis","conflicts":"/api/acts/ad-casa-9-engine-controls-propeller-feathering-system/conflicts","importantCases":"/api/acts/ad-casa-9-engine-controls-propeller-feathering-system/important-cases","documents":"/api/acts/ad-casa-9-engine-controls-propeller-feathering-system/documents"}}