{"id":"F2006B06211","name":"AD/PHZL/39 Amdt 1 - Propeller Damper - Replacement","slug":"ad-phzl-39-amdt-1-propeller-damper-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47101,"registerId":"commonwealth-F2006B06211-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/39 Amdt 1 - Propeller Damper - 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 - Hartzell\n\n \n\nAD/PHZL/39\n\nAmdt 1\n\n\nPropeller Damper - Replacement 4/76\n\n \n\nApplicability: All HC-C2YK-2CG( )/( )C7666A-2 and HC-C2YK-2CLG( )/( ) JC7666A-2\n\npropellers fitted with C-1576 damper assemblies.\n\n \n\nRequirement: Replace the C-1576 damper assembly with a new or reconditioned assembly.\n\n \n\nNote: Hartzell SB 110A refers.\n\n \n\nCompliance: Before installation on an aircraft following each reconditioning completed after 30 April 1976.\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":1502},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment appears to maintain the original scope of the 1976 directive regarding damper assembly replacement for specific Hartzell propeller models. There is no indication of expansion to additional propeller types or fundamental changes to the safety objective."},"complexity_factors":["Single operative requirement with no exceptions or nested conditions","Limited applicability to specific propeller model numbers requiring technical aviation knowledge","Compliance trigger depends on external maintenance events (reconditioning) rather than calendar time","Cross-reference to external technical document (Hartzell SB 110A) for implementation details"],"plain_english_summary":"This is a mandatory **Airworthiness Directive** (a legally binding safety order) issued by the Civil Aviation Safety Authority. It requires aircraft owners and maintenance engineers to replace specific damper assemblies in certain Hartzell propellers.\n\n**Who it affects:**\nAnyone operating or maintaining aircraft fitted with these specific Hartzell propeller models:\n* HC-C2YK-2CG( )/( )C7666A-2\n* HC-C2YK-2CLG( )/( )JC7666A-2\n\n*Only applies if the propeller has a C-1576 damper assembly installed.*\n\n**What you must do:**\nReplace the C-1576 damper assembly with a new or reconditioned assembly before installing the propeller on any aircraft. This applies every time the propeller is reconditioned (overhauled/repaired) after 30 April 1976.\n\n**Why it matters:**\nDamper assemblies reduce vibrations in variable-pitch propellers. This directive prevents potential failure of these components, which could damage the propeller or engine and compromise flight safety. Technicians should also consult Hartzell Service Bulletin 110A for technical guidance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-39-amdt-1-propeller-damper-replacement","history":"/api/acts/ad-phzl-39-amdt-1-propeller-damper-replacement/history","analysis":"/api/acts/ad-phzl-39-amdt-1-propeller-damper-replacement/analysis","conflicts":"/api/acts/ad-phzl-39-amdt-1-propeller-damper-replacement/conflicts","importantCases":"/api/acts/ad-phzl-39-amdt-1-propeller-damper-replacement/important-cases","documents":"/api/acts/ad-phzl-39-amdt-1-propeller-damper-replacement/documents"}}