{"id":"F2006B06296","name":"AD/PMC/41 Amdt 1 - Propeller Hub Eddy Current Inspection","slug":"ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47384,"registerId":"commonwealth-F2006B06296-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PMC/41 Amdt 1 - Propeller Hub Eddy Current Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/PMC/41 and issues the following AD under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nPropellers \\- Variable Pitch \\- McCauley\n\nAD/PMC/41\n\nAmdt 1\n\n  \nPropeller Hub Eddy Current Inspection 1/2004\n\nApplicability: All McCauley threaded propeller hubs.\n\nRequirement: Inspect the threaded area of the propeller hub assembly where the blade retention nut screws into the propeller hub using either:\n\n    The eddy current inspection (ECI) procedure detailed in McCauley standard practices manual (SPM) 101; or\n\n    b. An approved ECI procedure.\n\nNote 1: NDI/EC/McCauley/41 constitutes one such technique.\n\nNote 2: NDI/EC/McCauley/41 is only approved for the requirement detailed in this Directive. Refer CAR 2A (1988)\n\nCompliance: Whenever the propeller is dissembled to a point that would allow access to the propeller hub threaded area.\n\nThis Amendment becomes effective on 22 January 2004.\n\nBackground: This amendment includes reference to the manufacturers procedure that is a required task to be carried out each overhaul. NDI/EC/McCauley/41 is approved only for the inspection requirement of this Directive.\n\nA number of threaded hubs have failed during take-off resulting in propeller blade loss.\n\nThe original issue of this Directive became effective 21 April 1988.\n\n![Signature of James Coyne, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nJim Coyne\n\n![](image.001.png)Delegate of the Civil Aviation Safety Authority 4 December 2003\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 24 December 2003.\n\n  \n\nPage 1 of 1","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: preventing propeller hub failures through mandatory eddy current inspections. The 2004 amendment merely clarifies inspection procedures and aligns them with manufacturer overhaul requirements, without expanding the scope beyond McCauley threaded propeller hubs."},"complexity_factors":["Single page document with straightforward structure (Applicability, Requirement, Compliance, Background)","Only 2 defined inspection methods referenced (manufacturer's SPM 101 or approved alternative)","Simple trigger condition for compliance: 'whenever propeller is disassembled to allow access'","No nested exceptions, cross-references to other legislation, or conditional logic chains","Limited technical jargon, with key terms (eddy current inspection) explained through context","Single amendment to existing directive, not a complex legislative rewrite"],"plain_english_summary":"Australia’s aviation safety regulator (CASA) requires specialised eddy‑current inspections of McCauley propeller hub threads — using the manufacturer’s inspection manual or an approved alternative — whenever a propeller is disassembled enough to access the threads. \n\nIt affects owners, operators, licensed maintenance engineers and overhaul facilities. The amendment clarifies the manufacturer’s procedure as the primary method after blade separations during take‑off revealed catastrophic hub failures."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"This amendment explicitly references and requires the manufacturer’s ECI procedure (McCauley SPM 101 / NDI/EC/McCauley/41) as the task to be carried out at overhaul and clarifies that NDI/EC/McCauley/41 is approved only for this Directive. Mechanically, it adds the manufacturer’s procedure and a limited approval note to the existing inspection requirement (Requirement; Notes; Background)."},"complexity_factors":["Technical requirement: non‑destructive eddy‑current inspection (ECI) which requires specialist NDI capability and training (Requirement)","Applicability: covers all McCauley threaded propeller hubs, so affects all operators of those props (Applicability)","Compliance trigger: inspection timing is conditional — \"whenever the propeller is dissembled\" — so timing depends on maintenance schedules (Compliance)","Document references: relies on external procedures (McCauley SPM 101 and NDI/EC/McCauley/41) and an approval regime for alternative ECI methods (Requirement, Notes)","Limited approval scope: NDI/EC/McCauley/41 is explicitly approved only for this Directive, restricting discretion over technique choice (Note 2, Background)"],"plain_english_summary":"This AD requires inspection of the threaded area of all McCauley variable‑pitch propeller hubs (where the blade retention nut screws in) using an eddy‑current inspection (ECI) procedure — either McCauley SPM 101 or another CASA‑approved ECI. Inspections must be done whenever the propeller is disassembled sufficiently to access the hub threads.\n\nAircraft owners/operators pay for and arrange the inspection; the CASA delegate prescribes the inspection method and has noted that NDI/EC/McCauley/41 is approved only for this Directive and is referenced as the manufacturer’s overhaul task."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection","history":"/api/acts/ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection/history","analysis":"/api/acts/ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection/analysis","conflicts":"/api/acts/ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection/conflicts","importantCases":"/api/acts/ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection/important-cases","documents":"/api/acts/ad-pmc-41-amdt-1-propeller-hub-eddy-current-inspection/documents"}}