{"id":"F2006B06290","name":"AD/PMC/35 Amdt 1 - Propeller Blade Butt Retention Thread - Eddy Current Inspection","slug":"ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47364,"registerId":"commonwealth-F2006B06290-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PMC/35 Amdt 1 - Propeller Blade Butt Retention Thread - Eddy Current Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPropellers \\- Variable Pitch \\- McCauley\n\nAD/PMC/35\n\nAmdt 1\n\n  \n\nPropeller Blade Butt Retention Thread \\- Eddy Current Inspection\n\n  \n13/88\n\nApplicability: All threaded blade McCauley propellers.\n\nRequirement: In addition to the dye penetrant inspection described in the appropriate McCauley Propeller Service Manual, conduct an eddy current inspection of the tapered thread butt section of the propeller blade in accordance with technique approved by the Secretary.\n\nEddy Current Technique ATG/NDI/EC/5 constitutes one such technique. Copies of this technique, and test samples may be obtained through regional offices of the Authority.\n\nCompliance: 1. Each time propeller is overhauled.\n\n2. Whenever propeller disassembly will allow inspection of the blade butt retention threads.\n\nBackground: Two recent local failures have occurred at the butt thread section of McCauley propeller blades. One other cracked blade has been detected using eddy current equipment. All subject blades had shot peened and truncated threads. Laboratory tests indicate that the compressive surface formed by the shot peening process may prevent detection of substantial cracks when inspecting with dye penetrants.\n\nThis Amendment raised to clarify reinspection requirements.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","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: ensuring cracked propeller blades are detected before failure. The amendment merely clarifies reinspection timing rather than expanding coverage to new propeller types, new inspection methods, or new operational contexts."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined terms implicitly used (eddy current, dye penetrant) — both explained through context","Simple conditional structure: two clear trigger events for compliance","No cross-references to other legislation beyond generic 'Civil Aviation Regulations 1998' citation","Single technical requirement with one approved alternative method referenced (Technique ATG/NDI/EC/5)","No nested exceptions or layered definitions"],"plain_english_summary":"This CASA Airworthiness Directive requires owners and maintainers of McCauley variable‑pitch propellers to use eddy‑current inspections on the blade butt‑retention threads because shot‑peened surfaces can hide cracks from dye‑penetrant tests. Inspections are mandated at every propeller overhaul and whenever the blade attachment threads are exposed. The amendment clarifies when re‑inspections must be carried out after disassembly to prevent undetected cracks and potential in‑flight propeller failure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment clarifies reinspection requirements rather than expanding applicability: the directive still applies to all threaded McCauley propellers, but now specifies mandatory eddy‑current inspection at each overhaul and whenever disassembly allows, and requires an approved technique (e.g. ATG/NDI/EC/5) obtainable from the Authority."},"complexity_factors":["Technical requirement: mandates a specific non‑destructive test (eddy current) targeting a narrow component area (tapered thread butt), requiring specialist equipment and skill.","Approval discretion: inspection technique must be 'approved by the Secretary' (administrative approval step); ATG/NDI/EC/5 is an example rather than exhaustive.","Compliance triggers: two distinct timing rules — (1) each overhaul, and (2) whenever disassembly permits inspection — requiring operators to track both scheduled and opportunistic opportunities.","Operational burden: operators/maintenance organisations bear costs to acquire technique, equipment or send samples; Authority supplies technique and test samples via regional offices.","Detection trade‑off: background states dye penetrant can miss cracks on shot‑peened/truncated threads, creating a technical justification but also operational uncertainty about when additional testing is necessary.","Scope clarity: amendment specifically clarifies reinspection requirements, adding a procedural change rather than new substantive prohibitions.","Recordkeeping and procedural integration: maintenance providers must integrate the eddy‑current step into existing overhaul and disassembly workflows."],"plain_english_summary":"This directive requires an additional eddy‑current inspection of the tapered thread butt on all threaded McCauley propeller blades, to be done alongside the existing dye‑penetrant check. The inspection technique must be approved by the Secretary; ATG/NDI/EC/5 is given as an acceptable method and test samples are available from the Authority. Operators and maintenance organisations must carry out the eddy‑current check at each propeller overhaul and whenever disassembly allows inspection, because shot‑peened/truncated threads can hide cracks from dye penetrant."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection","history":"/api/acts/ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection/history","analysis":"/api/acts/ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection/analysis","conflicts":"/api/acts/ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection/conflicts","importantCases":"/api/acts/ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection/important-cases","documents":"/api/acts/ad-pmc-35-amdt-1-propeller-blade-butt-retention-thread-eddy-current-inspection/documents"}}