{"id":"F2006B06214","name":"AD/PHZL/50 - A-4025 Spring Retainer - Inspection","slug":"ad-phzl-50-a-4025-spring-retainer-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47109,"registerId":"commonwealth-F2006B06214-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/50 - A-4025 Spring Retainer - Inspection","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/50 A-4025 Spring Retainer - Inspection 2/84\n\nApplicability: Five bladed turbine propellers model HC-B5MP-3 Series, as listed in Service Letter No. 149.\n\n \n\nDocument: Hartzell Service Letter No. 149.\n\n \n\nCompliance: At next reconditioning or rectification necessitating disassembly, whichever is the sooner.\n\n \n\nBackground: The manufacturer advises that a significant number of retainers have been discovered possessing an inclusion consequently a one off inspection is required to preclude the possibility of retainer failure.\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":1713},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains its original targeted scope: a specific inspection for a identified manufacturing defect in a single part number. No expansion beyond the original safety purpose."},"complexity_factors":["Narrow applicability limited to specific propeller model (HC-B5MP-3 Series)","Single, clear compliance trigger (next disassembly event)","Minimal conditional logic or exceptions","Technical aviation terminology requires domain knowledge"],"plain_english_summary":"**What this does:** This is a safety rule requiring a one-time inspection of a specific aircraft part—the A-4025 spring retainer—on certain Hartzell five-bladed propellers (model HC-B5MP-3 series).\n\n**Who it affects:** Aircraft operators, owners, and maintenance organisations responsible for these specific propeller models.\n\n**What you must do:** Have the spring retainer inspected the next time the propeller is taken apart for reconditioning (overhaul) or repair—whichever happens first. The inspection looks for manufacturing defects (called \"inclusions,\" which are impurities or gaps inside the metal) that could cause the retainer to break.\n\n**Why it matters:** The manufacturer discovered that some retainers were made with internal defects that could lead to failure during operation. This rule ensures potentially dangerous parts are identified and replaced before they cause propeller failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-50-a-4025-spring-retainer-inspection","history":"/api/acts/ad-phzl-50-a-4025-spring-retainer-inspection/history","analysis":"/api/acts/ad-phzl-50-a-4025-spring-retainer-inspection/analysis","conflicts":"/api/acts/ad-phzl-50-a-4025-spring-retainer-inspection/conflicts","importantCases":"/api/acts/ad-phzl-50-a-4025-spring-retainer-inspection/important-cases","documents":"/api/acts/ad-phzl-50-a-4025-spring-retainer-inspection/documents"}}