{"id":"F2006B04829","name":"AD/CA25/1 Amdt 2 - Life Limited Components","slug":"ad-ca25-1-amdt-2-life-limited-components","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44630,"registerId":"commonwealth-F2006B04829-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CA25/1 Amdt 2 - Life Limited Components","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)  \nSkyfox Aviation (Hedaro) CA25 Series Aeroplanes\n\nAD/CA25/1\n\nAmdt 2\n\n  \nLife Limited Components 2/96\n\nApplicability: All CA22A/25, CA25, CA25N aircraft.\n\nRequirement: The following components are to be retired from service at the times shown: Component Maximum Time in Service\n\nWing Front and Rear Spars 4000 Hours Wing Lift Struts and Carry-Through Structure 4000 Hours Horizontal Stabiliser Spar 8000 Hours All Other Structure, Except Doors and Fairings 8000 Hours\n\nCompliance: As specified in the Requirement, with effect from 1 February 1996.\n\nBackground: The life limits in this directive are the best estimates of when fatigue cracking will become unacceptably likely.\n\nAmendment 1 extended the life limits of the components based on stress and fatigue analyses supplied by the manufacturer. This Amendment includes the CA25N and clarifies the definition of other primary structure.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This Amendment extends the AD to include the CA25N model and clarifies the definition of \"other primary structure.\" It follows Amendment 1, which extended life limits based on manufacturer-supplied stress and fatigue analyses; those prior changes adjusted the retirement times that operators must observe. (See: \"Background\"; \"Applicability\"; \"Requirement\")."},"complexity_factors":["Clear, short list of components and single metric for retirement (hours in service) reduces technical complexity (\"Requirement\").","Obligation to track hours-in-service imposes administrative compliance tasks on operators (implied by \"Requirement\").","Technical judgment embedded in life-limit estimates and reliance on fatigue analyses introduces scientific uncertainty and implementation risk (\"Background\").","Inclusion of multiple aircraft models (CA22A/25, CA25, CA25N) requires operators of different subtypes to check applicability (\"Applicability\").","Clarification of what counts as \"other primary structure\" reduces legal ambiguity but requires interpretation of that definition in maintenance records (\"Background\").","Compliance effective date fixed in time creates transitional scheduling for operators (\"Compliance\")."],"plain_english_summary":"This Airworthiness Directive forces retirement of specified structural components on Skyfox (Hedaro) CA22A/25 and CA25N aeroplanes after set hours-in-service to limit fatigue-crack risk (mandatory from 1 Feb 1996). It adds CA25N and clarifies what counts as “other primary structure.”\n\nOwners/operators must track component hours and pay for removal/replacement, creating predictable demand for parts and maintenance and shifting fatigue-management costs onto operators."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original 1996 directive covered CA22A/25 and CA25 aircraft. Amendment 1 expanded the scope by extending life limits based on new engineering analysis. This Amendment 2 further expands scope by adding the CA25N variant and clarifying structural definitions, moving from a narrow original application to a broader coverage of the aircraft family."},"complexity_factors":["Very short document (approximately 250 words)","Only 4 defined component categories with specific hour limits","Simple tabular structure for requirements","Minimal cross-referencing (only refers to previous amendments in background)","No nested conditions or exceptions — straightforward compliance deadline","Single applicability clause covering three aircraft variants"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance actions on aircraft.\n\n**What it does:**\nThis directive sets **strict time limits** on how long certain parts of Skyfox Aviation CA25 series aeroplanes can remain in service before they must be permanently retired (replaced). These \"life limited components\" are critical structural parts that can develop dangerous fatigue cracks over time.\n\n**Which aircraft are affected:**\n- CA22A/25\n- CA25\n- CA25N\n\n**The retirement deadlines:**\n| Component | Maximum Flight Hours |\n|-----------|---------------------|\n| Wing front and rear spars (the main structural beams inside the wings) | 4,000 hours |\n| Wing lift struts and carry-through structure (parts that transfer wing loads to the fuselage) | 4,000 hours |\n| Horizontal stabiliser spar (main beam in the tailplane) | 8,000 hours |\n| All other primary structure (except doors and fairings) | 8,000 hours |\n\n**Why it matters:**\nFatigue cracks in aircraft structures can lead to catastrophic failure. This directive prevents accidents by forcing owners to replace aging structural components before they become unsafe. The time limits are based on engineering analysis of when cracks become \"unacceptably likely.\"\n\n**History:**\n- Original directive issued February 1996\n- Amendment 1 extended some life limits based on new manufacturer data\n- **This Amendment 2** adds the CA25N variant to the rules and clarifies what counts as \"other primary structure\""}},"importantCases":[],"_links":{"self":"/api/acts/ad-ca25-1-amdt-2-life-limited-components","history":"/api/acts/ad-ca25-1-amdt-2-life-limited-components/history","analysis":"/api/acts/ad-ca25-1-amdt-2-life-limited-components/analysis","conflicts":"/api/acts/ad-ca25-1-amdt-2-life-limited-components/conflicts","importantCases":"/api/acts/ad-ca25-1-amdt-2-life-limited-components/important-cases","documents":"/api/acts/ad-ca25-1-amdt-2-life-limited-components/documents"}}