{"id":"F2006B03578","name":"AD/BEA 121/14 Amdt 3 - Fuselage/Mainplane Attachments","slug":"ad-bea-121-14-amdt-3-fuselage-mainplane-attachments","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43145,"registerId":"commonwealth-F2006B03578-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEA 121/14 Amdt 3 - Fuselage/Mainplane Attachments","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)  Beagle B121 (Pup) Series Aeroplanes\n\n \n\nAD/BEA 121/14\n\nAmdt 3\n\n\nFuselage/Mainplane Attachments 11/77\n\n \n\nApplicability: All model B121 Series 1 fitted with fuselage to mainplane attachment fittings NOT modified in accordance with a scheme approved by the manufacturer.\n\n \n\nRequirement: Action in accordance with Scottish Aviation SB No. B121/75. Compliance:  As detailed in the Requirement Document.\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":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The text supplied sets a focused scope: all Beagle B121 Series 1 aircraft that retain the original fuselage-to-mainplane attachment fittings are subject to the directive unless previously modified under a manufacturer-approved scheme (\"Applicability\"). The instrument itself does not indicate any expansion or narrowing of scope relative to an earlier instrument; it references amendment numbering (Amdt 3) but provides no comparative language showing a change in applicability or substantive scope within the supplied text."},"complexity_factors":["Narrow, specific applicability limited to B121 Series 1 aircraft with original fuselage-to-mainplane fittings (low breadth complexity) (\"Applicability\")","Substantive requirements are contained in an external document (Scottish Aviation SB No. B121/75) rather than in the AD text itself, creating dependence on external material for implementation (moderate complexity) (\"Requirement\")","Compliance detail deferred to a Requirement Document which is not reproduced here, leaving timing, procedures and acceptance criteria unspecified in the AD (adds implementation uncertainty)","Exemption condition hinges on prior modification under a manufacturer‑approved scheme, which requires documentary verification and may invite interpretive questions (moderate complexity) (\"Applicability\")","Short, straightforward regulatory structure (low procedural complexity), but practical cost, parts and labour implications vary by operator and are not specified"],"plain_english_summary":"The Civil Aviation Safety Authority has issued an airworthiness directive requiring owners/operators of Beagle B121 Series 1 aeroplanes still fitted with original fuselage‑to‑mainplane attachment fittings to carry out the work specified in Scottish Aviation Service Bulletin No. B121/75, with timing and detail set by the referenced Requirement Document.\n\nAffected operators must obtain and fund the mandated inspections/repairs; aircraft previously modified under a manufacturer‑approved scheme are the only explicit exemption."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 3 to an existing Airworthiness Directive originally issued in November 1977 (as indicated by '11/77'). The scope remains tightly focused on the specific structural safety issue of fuselage-to-mainplane attachments in Beagle B121 Series 1 aircraft. There is no evidence of scope creep; the amendments likely update compliance times, clarify applicability, or incorporate revised manufacturer guidance without expanding beyond the original safety purpose."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory text","No defined terms section — relies entirely on external reference to Scottish Aviation SB No. B121/75","Single, clear applicability criterion (unmodified B121 Series 1 aircraft)","No nested conditions, exceptions, or cross-references to other legislation","Simple binary compliance structure: either modified per approved scheme (exempt) or not (must comply)","External incorporation by reference to a single technical document rather than detailed prescription in the instrument itself"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft instead of cars.\n\n**What it does:** It requires owners and operators of specific **Beagle B121 (Pup) Series 1 aeroplanes** to inspect and potentially fix a critical structural problem — the attachment points where the wings (mainplane) connect to the fuselage (the main body of the aircraft).\n\n**Who it affects:** Anyone who owns or operates a Beagle B121 Series 1 aircraft that **hasn't** already been modified with an approved manufacturer's fix for the wing attachment fittings.\n\n**What must be done:** Operators must follow the instructions in **Scottish Aviation Service Bulletin No. B121/75** — a technical document from the original manufacturer detailing the required inspection or repair work. The exact deadlines and methods are set out in that bulletin.\n\n**Why it matters:** The fuselage-to-wing attachments are literally what keeps the wings attached to the plane. If these fittings fail, the wing could separate from the aircraft in flight — with catastrophic consequences. This AD ensures potentially dangerous aircraft are identified and fixed before they fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bea-121-14-amdt-3-fuselage-mainplane-attachments","history":"/api/acts/ad-bea-121-14-amdt-3-fuselage-mainplane-attachments/history","analysis":"/api/acts/ad-bea-121-14-amdt-3-fuselage-mainplane-attachments/analysis","conflicts":"/api/acts/ad-bea-121-14-amdt-3-fuselage-mainplane-attachments/conflicts","importantCases":"/api/acts/ad-bea-121-14-amdt-3-fuselage-mainplane-attachments/important-cases","documents":"/api/acts/ad-bea-121-14-amdt-3-fuselage-mainplane-attachments/documents"}}