{"id":"F2006B09983","name":"AD/FU24/36 - Fuselage Structure - Modification","slug":"ad-fu24-36-fuselage-structure-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55292,"registerId":"commonwealth-F2006B09983-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/FU24/36 - Fuselage Structure - Modification","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)  Airparts (NZ) Ltd. FU 24 Series Aeroplanes\n\n \n\nAD/FU24/36 Fuselage Structure - Modification 1/71\n\nApplicability: All models fitted with Fibreglass Hopper P/N 249368. Document:  Air Parts SL No. 4.\n\nCompliance: Forthwith.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \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":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1971 (as indicated by '1/71' in the identifier). It addresses one specific structural modification for one specific aircraft component. There is no evidence of scope creep; it remains tightly focused on its original safety purpose."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory content","No defined terms section; all terminology is standard aviation nomenclature","Single, unambiguous compliance requirement ('Forthwith') with no conditional exceptions","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Refers to external technical document (Service Letter No. 4) but does not reproduce its contents","No nested logic, temporal phases, or alternative compliance methods"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of certain Airparts (NZ) Ltd FU 24 series aircraft to modify the **fuselage structure** (the main body of the plane). Specifically, it applies to planes fitted with a **Fibreglass Hopper** — a container typically used for agricultural spraying or firefighting — with part number 249368.\n\n**Who it affects:** Anyone who owns or operates an FU 24 series aircraft with this specific fibreglass hopper installed.\n\n**What they must do:** They must follow the modification instructions in **Air Parts Service Letter No. 4** (a technical document from the manufacturer). The word **\"Forthwith\"** means immediately — there's no grace period. The aircraft cannot legally fly until this is done.\n\n**Why it matters:** Airworthiness Directives are legally binding safety fixes. They typically issue when CASA or the manufacturer discovers a defect, damage risk, or structural weakness that could affect flight safety. Ignoring this directive grounds the aircraft and exposes the operator to serious penalties."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The provided directive text applies to all models fitted with Fibreglass Hopper P/N 249368 and mandates modification pursuant to Air Parts SL No. 4 with immediate effect. There is no indication in the supplied text that the scope has been altered from an earlier or original intent; the AD’s scope is stated directly in the applicability line."},"complexity_factors":["Narrow applicability limited to aircraft fitted with Fibreglass Hopper P/N 249368 (Applicability)","Mandatory immediate compliance language: “Forthwith” creates timing pressure (Compliance)","Technical instructions are external: Air Parts SL No. 4 contains the actual modification procedure (Document)","AD text contains minimal technical detail, requiring operators to obtain and rely on another document (Document)","No exemptions, alternatives, or staged compliance in the AD text increases operational and logistical complexity (Compliance)"],"plain_english_summary":"The Civil Aviation Safety Authority mandates immediate modification of any aircraft fitted with Fibreglass Hopper P/N 249368, requiring operators/owners to carry out the work “forthwith” in accordance with Air Parts SL No. 4. Compliance is compulsory and enforced under Part 39.\n\nThe AD delegates technical steps to that external service letter, so operators bear direct costs, downtime and must obtain the SL for implementation; the directive itself gives no safety rationale, cost estimate or timing alternatives."}},"importantCases":[],"_links":{"self":"/api/acts/ad-fu24-36-fuselage-structure-modification","history":"/api/acts/ad-fu24-36-fuselage-structure-modification/history","analysis":"/api/acts/ad-fu24-36-fuselage-structure-modification/analysis","conflicts":"/api/acts/ad-fu24-36-fuselage-structure-modification/conflicts","importantCases":"/api/acts/ad-fu24-36-fuselage-structure-modification/important-cases","documents":"/api/acts/ad-fu24-36-fuselage-structure-modification/documents"}}