{"id":"F2006B07602","name":"AD/WILGA/1 Amdt 3 - Airworthiness Limitation","slug":"ad-wilga-1-amdt-3-airworthiness-limitation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50282,"registerId":"commonwealth-F2006B07602-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/WILGA/1 Amdt 3 - Airworthiness Limitation","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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  PZL 104 (Wilga) Series Aeroplanes\n\n \n\n# AD/WILGA/1\n\nAmdt 3\n\nApplicability: All models.\n\n# Airworthiness Limitation 10/97\n\n \n\nRequirement: 1. For aeroplanes up to Series 21, except aircraft with manufacturer number CF21950952, CF21950954, CF21950959, CF21950960 and CF21950961: Retire\n\nthe fuselage spar framework CE 111500 (wing carry through spar) from service.\n\n \n\n2. Retire the airframe from service.\n\n \n\nNote: PZL Service Bulletin No 10496025 refers.\n\n \n\nCompliance: 1. For requirement 1, before 2600 hours time in service.\n\n \n\n2. For requirement 2, before 5200 hours time in service. This amendment is effective from 11 September 1997.\n\nBackground: This directive specifies the airworthiness limitations of the PZL-104 Wilga 80 airframe. This amendment reflects the latest issue of the applicable mandatory service bulletin. Extension of the service life from 2600 hours to 5200 hours for early models no longer requires replacement of the lower main wing ferrule. For later models, no items need be replaced to achieve the service life of 5200 hours.\n\n \n\nAmendment 1 of this AD extended the fatigue life limitation from 2400 hours to 5200 hours.\n\n \n\nAmendment 2 clarified the actions required to extend the airframe fatigue life limitation to 5200 hours.\n\n \n\nAmendment 2 of this Airworthiness Directive became effective on 22 June 1995.\n\n \n\nAmendment 1 of this Airworthiness Directive became effective on 27 December 1990.\n\n \n\nThe original issue of this Airworthiness Directive became effective on 1 November 1990.\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":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original 1990 directive set a 2,400-hour life limit. Amendment 1 (1990) extended this to 5,200 hours. Amendment 2 (1995) clarified the technical steps to achieve this extension. Amendment 3 (1997) further refined the requirements, removing the need for lower main wing ferrule replacement on early models and simplifying compliance for later models. The scope has evolved from simple retirement orders to a more nuanced, model-differentiated fatigue management regime."},"complexity_factors":["Short, single-purpose directive with only 2 substantive requirements","Limited conditional logic: two applicability categories (early vs late models) plus 5 specific serial number exemptions","No defined terms section — uses plain technical language (spar, ferrule, airframe)","Minimal cross-referencing: only references one service bulletin (PZL Service Bulletin No 10496025)","Clear compliance deadlines expressed in flight hours (not calendar time)","Historical amendment trail included but does not affect current interpretation"],"plain_english_summary":"This CASA Airworthiness Directive is a mandatory retirement schedule for PZL 104 Wilga aircraft in Australia: it imposes flight‑hour limits on continued operation to prevent metal‑fatigue failure (central wing spar and whole‑airframe limits), with five specific serial-numbered aircraft exempt from one requirement.\n\nIt affects owners/operators of these Wilgas and has been amended three times as structural life data and design improvements evolved."},"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Yes. The directive’s scope has been altered from earlier issues: Amendment 1 increased the fatigue life limit (from 2,400 hours) to 5,200 hours and Amendment 2 clarified steps to obtain the extended life. The current amendment (effective 11 Sep 1997) sets the spar retirement at 2,600 hours for certain early models and the airframe retirement at 5,200 hours, and removes a prior lower‑main‑wing ferrule replacement requirement for early models (Background; Amendments 1–2)."},"complexity_factors":["Conditional applicability: Requirement 1 applies only to \"aeroplanes up to Series 21\" with specific manufacturer‑number exceptions (Requirement 1).","Two-tier service‑life limits: separate retirement deadlines for the spar (2,600 hours) and the airframe (5,200 hours) (Compliance: 1 & 2).","Explicit manufacturer‑number exclusions increase identification and record‑checking burden (Requirement 1).","Dependency on external technical material (PZL Service Bulletin No 10496025) for implementation detail (Note).","Amendment history and prior life‑limit changes require reconciling earlier maintenance records (Background; Amendments 1–2).","Operational compliance requires accurate tracking of time‑in‑service and coordination of part removal or aircraft disposal (Requirements & Compliance).","Differential treatment of early vs later models and changes to required replacements (Background) create variant‑specific maintenance rules."],"plain_english_summary":"This airworthiness directive requires retirement of a specific fuselage spar (CE 111500) on early PZL‑104 Wilga aeroplanes before 2,600 hours time in service and mandates retirement of the entire airframe before 5,200 hours. It applies to all Wilga models but contains serial‑number exceptions for the spar requirement.\n\nAircraft owners/operators must monitor hours‑in‑service, remove the listed spar or retire the aeroplane by the stated hour limits, and follow the referenced PZL service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-wilga-1-amdt-3-airworthiness-limitation","history":"/api/acts/ad-wilga-1-amdt-3-airworthiness-limitation/history","analysis":"/api/acts/ad-wilga-1-amdt-3-airworthiness-limitation/analysis","conflicts":"/api/acts/ad-wilga-1-amdt-3-airworthiness-limitation/conflicts","importantCases":"/api/acts/ad-wilga-1-amdt-3-airworthiness-limitation/important-cases","documents":"/api/acts/ad-wilga-1-amdt-3-airworthiness-limitation/documents"}}