{"id":"F2006B06868","name":"AD/SD3-60/24 - Propeller Blade Model M10876K","slug":"ad-sd3-60-24-propeller-blade-model-m10876k","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114748,"registerId":"commonwealth-F2006B06868-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SD3-60/24 - Propeller Blade Model M10876K","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nShort SD3-60 Series Aeroplanes\n\nAD/SD3-60/24 Propeller Blade Model M10876K 11/87\n\nDM\n\nApplicability: All Shorts SD3-60 aircraft fitted with Hartzell Model HC-B5HP-3( )/M10876K propellers.\n\nRequirement: Action in accordance with Shorts SD3-60 Service Bulletin No SD360-61-06.\n\nNote: Hartzell Service Bulletin No 154 refers.\n\nCompliance: (i) Blades with 0 to 3000 hours time in service since new will require inspection of the blade internal bearing hole in accordance with Hartzell Service Bulletin 136D prior to completing 3000 hours total time in service.\n\n    (ii) For blades in excess of 3000 hours time in service and which have accumulated in excess of 300 flights since the last inspection in accordance with Hartzell Service Bulletin 136D are required to be reinspected in accordance with Hartzell Service Bulletin 136D prior to accumulating an additional 100 flights.\n\n    (iii) Blades which have accumulated less than 300 flights are required to be reinspected in accordance with Hartzell Service Bulletin 136D at 300 flights or the accumulation of 100 additional flights from 24 August 1987 whichever is the greater.\n\n    (iv) Following completion of initial inspection as required by sub-paras (i), (ii) or (iii), as applicable, all blades must be inspected in accordance with Hartzell Service Bulletin 136D at each and every subsequent 300 flight interval until retired from service.\n\n    (v) All model M10876K blades are to be retired from service by 31 March 1988.\n\nBackground: There have been a limited number of M10876K blade shank cracks with one blade separating from an aircraft. Cause of the shank crack appears to be related to minor corrosion pits located in the blade internal bearing hole. Blade bearing hole corrosion has already been addressed by Hartzell Service Bulletin 136D. A replacement blade M10876ASK will be available from mid-August 1987.","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":4,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: addressing a specific safety defect in a specific propeller model on a specific aircraft type. The compliance structure, while detailed, directly serves the single purpose of mitigating the identified blade crack risk through inspection and retirement timelines."},"complexity_factors":["Multiple conditional compliance pathways based on flight hours and flight counts (5 sub-paragraphs with interlocking conditions)","Cross-references to external technical documents (Shorts Service Bulletin SD360-61-06 and Hartzell Service Bulletin 136D) without reproducing their content","Date-based calculation requirement ('whichever is the greater' comparison between flight count and calendar date)","Nested temporal logic: initial inspection triggers different ongoing obligations than subsequent inspections","Technical aviation terminology requiring domain knowledge (time in service, flight intervals, blade shank, bearing hole corrosion)"],"plain_english_summary":"This CASA Airworthiness Directive orders inspections and eventual removal of Hartzell M10876K propeller blades fitted to Shorts SD3-60 aircraft due to corrosion-prone bearing holes that have led to a blade separating in flight. \n\nIt affects operators and maintenance engineers — requiring urgent, scheduled inspections and mandatory retirement of the affected blades by 31 March 1988 to prevent in‑flight failure and catastrophic damage."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument sets inspection and retirement requirements for M10876K blades and applies to all Shorts SD3-60 aircraft fitted with those blades. The text contains no indication that the scope has been expanded or narrowed from an earlier intent."},"complexity_factors":["Narrow applicability to a specific airframe and propeller model (Shorts SD3-60 with Hartzell M10876K).","Cross-references to external technical documents: Shorts Service Bulletin SD360-61-06 and Hartzell Service Bulletins 136D and 154.","Multiple, conditional compliance timings (Compliance (i)–(iii)) based on hours-in-service and flight counts.","Recurring inspection requirement at fixed flight intervals (Compliance (iv)).","Mandatory retirement date for all affected blades (Compliance (v)).","Operational and economic impacts fall directly on aircraft operators (inspection, replacement, downtime).","Technical inspection procedures are prescribed by the referenced service bulletin rather than by the directive itself."],"plain_english_summary":"This Airworthiness Directive requires operators of Shorts SD3-60 aircraft fitted with Hartzell M10876K propeller blades to carry out recurring inspections of the blade internal bearing hole per Hartzell Service Bulletin 136D and to retire all M10876K blades by 31 March 1988. It responds to observed shank cracks linked to corrosion pits and one blade separation (Background); the inspection timetable uses flight-hour and flight-count thresholds and imposes inspection, replacement and downtime costs on aircraft operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-60-24-propeller-blade-model-m10876k","history":"/api/acts/ad-sd3-60-24-propeller-blade-model-m10876k/history","analysis":"/api/acts/ad-sd3-60-24-propeller-blade-model-m10876k/analysis","conflicts":"/api/acts/ad-sd3-60-24-propeller-blade-model-m10876k/conflicts","importantCases":"/api/acts/ad-sd3-60-24-propeller-blade-model-m10876k/important-cases","documents":"/api/acts/ad-sd3-60-24-propeller-blade-model-m10876k/documents"}}