{"id":"F2006B08950","name":"AD/DH114/39 - Nose Undercarriage Radius Rod Adjusting Screw - Replacement","slug":"ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52590,"registerId":"commonwealth-F2006B08950-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH114/39 - Nose Undercarriage Radius Rod Adjusting Screw - Replacement","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)  DH114 (Heron) Series Aeroplanes\n\n \n\nAD/DH114/39 Nose Undercarriage Radius Rod NK\n\nAdjusting Screw - Replacement\n\n \n\nApplicability: All models.\n\n \n\nDocument: Hawker Siddeley TNS Heron (114) No. U.16. Compliance: Before 1 November 1973.\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 safety directive. Airworthiness Directives are inherently narrow in scope — each addresses a specific defect or unsafe condition in a specific aircraft type. There is no evidence of scope creep; the directive does exactly what its title suggests and nothing more."},"complexity_factors":["Extremely short — only 8 substantive lines of regulatory text","Single, unambiguous operative requirement (replacement of one named part)","No defined terms section — all terms are either common mechanical vocabulary or reference external technical documents","No conditional logic, exceptions, or nested provisions","Simple binary applicability (all models) with no carve-outs or exemptions","Cross-reference to only one external technical document (Hawker Siddeley TNS Heron No. U.16), which is standard practice for aircraft maintenance directives"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nOrders owners and operators of **DH114 (Heron) series aeroplanes** to replace the **nose undercarriage radius rod adjusting screw** — a specific mechanical component in the aircraft's front landing gear.\n\n**Who it affects:**\nAnyone who owns or operates any model of the DH114 Heron aircraft (a British-made twin-engine airliner from the 1950s–60s).\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If this part isn't replaced by the deadline (**1 November 1973**), the aircraft cannot legally fly. The directive references a technical document (Hawker Siddeley TNS Heron No. U.16) that presumably details the defect or failure mode that makes this replacement necessary — likely a structural or mechanical flaw that could compromise the nose landing gear's integrity.\n\n**Key point:** This is a **time-expired historical directive**. The compliance date passed over 50 years ago. It remains on the statute books as part of Australia's aviation safety record, but would only be relevant today if someone were restoring or attempting to return a Heron aircraft to service."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Based on the AD text supplied, the scope appears unchanged: it applies to all DH114 Heron models and mandates replacement of the nose undercarriage radius rod adjusting screw by the stated deadline. The AD delegates technical procedures and the detailed rationale to the referenced manufacturer document (Hawker Siddeley TNS Heron (114) No. U.16). There is no indication in the excerpt that the applicability or the required action has been broadened or narrowed from what is expressed here."},"complexity_factors":["Single, discrete mandatory action (replace a specific component) reduces procedural complexity.","Clear, fixed compliance deadline limits scheduling ambiguity but creates time pressure.","Applicability to 'All models' increases scope of operational coverage and aggregate cost for fleet operators.","Technical execution and justification are delegated to an external manufacturer document (U.16), so implementers must obtain and follow that document.","AD text lacks in‑line technical detail or stepwise instructions, increasing reliance on external materials and competent maintenance personnel.","Regulatory enforcement is straightforward (a mandatory AD) but practical complexity depends on parts availability and maintenance scheduling."],"plain_english_summary":"This AD mandates replacement of the nose undercarriage radius‑rod adjusting screw on all DH114 (Heron) models, to be completed before 1 November 1973, citing Hawker Siddeley TNS Heron (114) No. U.16 for technical procedure. It affects every operator/owner of the type: compliance is compulsory, maintenance organisations carry out the work, and operators bear parts, labour and downtime costs — failure to comply risks regulatory breach."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement","history":"/api/acts/ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement/history","analysis":"/api/acts/ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement/analysis","conflicts":"/api/acts/ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement/conflicts","importantCases":"/api/acts/ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement/important-cases","documents":"/api/acts/ad-dh114-39-nose-undercarriage-radius-rod-adjusting-screw-replacement/documents"}}