{"id":"F2006B09996","name":"AD/FU24/49 - Centre Wing, Outboard Rear Fitting - Inspection and Modification","slug":"ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55343,"registerId":"commonwealth-F2006B09996-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/FU24/49 - Centre Wing, Outboard Rear Fitting - Inspection and 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/FU24/49  Centre Wing, Outboard Rear Fitting - Inspection and Modification\n\nApplicability: All model FU24-950 with S/Nos. prior to 189. Document:  Aerospace SB ASB/FU/018.\n\nCompliance: 1. Inspect within 25 hours time in service after 15 December 1975.\n\n \n\n2. Modify within 100 hours time in service after 15 December 1976.\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\n1/76\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied AD does not contain any text indicating a change to its original scope. It sets applicability (FU24-950 with S/Ns prior to 189) and prescribes an inspection and a modification with specific compliance windows and a referenced service bulletin. No amendment history or alteration to scope is present in the document provided."},"complexity_factors":["Narrow applicability limited to FU24-950 aircraft with serial numbers prior to 189 (requires checking serial numbers).","Two-step compliance schedule with different deadlines tied to calendar reference dates (25 hours after 15 Dec 1975; 100 hours after 15 Dec 1976).","Dependence on an external technical document (Aerospace SB ASB/FU/018) for inspection and modification procedures.","Mandatory regulatory nature (Part 39 AD) creates operational and administrative compliance requirements for operators.","Absence of detailed rationale, cost, or enforcement information in the text increases need to consult supplementary material or regulator guidance."],"plain_english_summary":"# What this directive does\n\n- This is an airworthiness directive (AD) issued under the Civil Aviation Regulations, Part 39 (Civil Aviation Safety Authority). It applies to a specific set of aircraft and sets mandatory inspection and modification tasks.\n\n- Applicability: All Airparts (NZ) Ltd. FU24-950 aeroplanes with serial numbers prior to 189. (See: \"Applicability: All model FU24-950 with S/Nos. prior to 189.\")\n\n- Required actions and timing: Operators of the affected aeroplanes must:\n  - Carry out an inspection of the centre wing outboard rear fitting within 25 hours time in service after 15 December 1975. (See: \"Inspect within 25 hours time in service after 15 December 1975.\")\n  - Carry out a modification of the same fitting within 100 hours time in service after 15 December 1976. (See: \"Modify within 100 hours time in service after 15 December 1976.\")\n\n- Reference document: The AD refers to Aerospace Service Bulletin ASB/FU/018 for the technical details of the inspection and modification. (See: \"Document: Aerospace SB ASB/FU/018.\")\n\n# Who this affects and who decides\n\n- Affected parties: Owners and operators of FU24-950 aircraft with serial numbers before 189. They are required to perform the inspection and later the modification on the specified schedule.\n\n- Decision authority: The Civil Aviation Safety Authority issued the AD under Part 39; it prescribes mandatory compliance steps and deadlines. The technical method and procedures are referenced to the Aerospace service bulletin.\n\n# How it works mechanically\n\n- The AD identifies the subset of aircraft to which it applies (serial number cut-off).\n- It sets two discrete compliance windows tied to calendar reference dates: a short-term inspection (within 25 hours TIS after 15 December 1975) and a later mandatory modification (within 100 hours TIS after 15 December 1976).\n- The AD delegates the technical details of how to inspect and how to modify to the referenced service bulletin (Aerospace SB ASB/FU/018).\n\n# Compliance, incentives and burdens (source-based)\n\n- Compliance is mandatory for the specified aircraft: operators must schedule and perform the inspection and, later, the modification in the stated time windows.\n- The AD relies on an external technical document (Aerospace SB ASB/FU/018) for the procedures; operators must obtain and follow that bulletin to complete the required work.\n- The document itself does not state costs, penalties, or enforcement mechanisms beyond the AD requirements; operators therefore bear the practical burden of arranging and paying for the inspection and modification, and of determining compliance timing by reference to serviceable time-in-service records.\n\n# Note on rationale\n\n- The AD text supplied sets mandatory actions and timing but does not include an explicit statement of the safety issue or empirical rationale for the measures. The AD references the service bulletin for technical content but does not describe the underlying problem or expected benefits within the supplied text.\n\n(All quoted timing and applicability language taken directly from the AD: \"Applicability: All model FU24-950 with S/Nos. prior to 189.\"; \"Document: Aerospace SB ASB/FU/018.\"; \"Inspect within 25 hours time in service after 15 December 1975.\"; \"Modify within 100 hours time in service after 15 December 1976.\")"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1976 addressing a specific structural defect in a limited aircraft population. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document — only 4 substantive lines of requirements","Single defined applicability criterion (model FU24-950, S/Nos. prior to 189)","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Simple two-step compliance timeline with clear hour-based deadlines","No nested conditions, exceptions, or discretionary provisions","References only one external technical document (Aerospace SB ASB/FU/018)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific **Airparts FU24-950 aircraft** (a type of agricultural aeroplane) with serial numbers below 189.\n\n**What it requires:**\n- **Inspection:** Owners/operators must inspect a specific part of the aircraft — the **centre wing outboard rear fitting** — within 25 hours of flying time after 15 December 1975.\n- **Modification:** They must also modify this same fitting within 100 hours of flying time after 15 December 1976.\n\n**Why it matters:**\nThis AD addresses a potential structural weakness in the wing attachment area. If left unchecked, this could lead to wing failure and catastrophic accidents. The phased approach (inspect first, modify later) allowed operators to continue limited operations while ensuring safety and planning for the permanent fix.\n\n**Who must comply:**\nAnyone operating the affected FU24-950 aircraft in Australia. Non-compliance means the aircraft cannot legally fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification","history":"/api/acts/ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification/history","analysis":"/api/acts/ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification/analysis","conflicts":"/api/acts/ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification/important-cases","documents":"/api/acts/ad-fu24-49-centre-wing-outboard-rear-fitting-inspection-and-modification/documents"}}