{"id":"F2006B08960","name":"AD/DH114/48 - Aileron Mass Balance Weight Assembly","slug":"ad-dh114-48-aileron-mass-balance-weight-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52534,"registerId":"commonwealth-F2006B08960-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH114/48 - Aileron Mass Balance Weight Assembly","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/DH114/48 Aileron Mass Balance Weight Assembly 7/87\n\nApplicability: All models.\n\n \n\nRequirement: 1. Action in accordance with British Aerospace TNS W19 Issue 1, or\n\n \n\n2. Inspect in accordance with a scheme approved by the Secretary. Compliance: Unless already accomplished;\n\n1. In accordance with the Requirement Document, but no later than 31 August 1987.\n\n\n \n\n2.    At the next inspection for Maintenance Release issue after 30 June 1987 but no later than 31 August 1987.\n\n \n\nBackground: A case has been reported of severe internal corrosion. Loss or failure of the balance assembly may cause aileron flutter or severe handling problems.\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, time-limited safety directive targeting a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of addressing aileron mass balance corrosion in DH114 Herons."},"complexity_factors":["Single, specific aircraft type (DH114 Heron)","Only two compliance pathways (manufacturer's instructions or Secretary-approved scheme)","Fixed, absolute deadline (31 August 1987)","No defined terms section, no cross-references to other legislation","Background explanation provided in plain language","Total length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nOrders owners and operators of **DH114 (Heron) series aeroplanes** to inspect or replace the **aileron mass balance weight assembly** — a component that prevents dangerous vibrations (flutter) in the aircraft's wing flaps (ailerons).\n\n**Why it matters:**\nSevere internal corrosion has been found in these assemblies. If the balance weight fails or falls off, the ailerons could flutter uncontrollably, causing **loss of control** or **severe handling problems**.\n\n**Who must act:**\nAnyone operating these specific British-made aircraft.\n\n**What must be done:**\n- **Option 1:** Follow the manufacturer's technical instructions (British Aerospace TNS W19 Issue 1), **or**\n- **Option 2:** Use an alternative inspection scheme approved by the Secretary (of the Department of Transport).\n\n**Deadlines:**\n- If following the manufacturer's document: by **31 August 1987**\n- If using an approved alternative scheme: at the next scheduled maintenance check after **30 June 1987**, but no later than **31 August 1987**"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive applies to \"All models\" of the DH114 (Heron) series and mandates inspection or action to address reported internal corrosion of the aileron mass balance weight assembly. The text provides no indication that the instrument's scope was altered from its stated purpose of mitigating the corrosion-related risk; it is limited to the specified aircraft and assembly and to the two compliance routes described (Applicability; Requirement; Background)."},"complexity_factors":["Short, focused scope limited to the DH114 (Heron) series (Applicability)","Two straightforward compliance routes: follow a named technical document or an alternate Secretary‑approved inspection scheme (Requirement)","Hard deadline plus an alternate maintenance‑release trigger creates modest scheduling complexity (Compliance)","Reference to an external technical document (British Aerospace TNS W19 Issue 1) requires operators to obtain and follow that material (Requirement)","Regulatory discretion in approving alternate schemes introduces administrative variability (Requirement)","Technical nature of the work requires qualified maintenance resources, which can affect logistics and cost (Requirement; Background)"],"plain_english_summary":"This AD requires all De Havilland DH114 (Heron) aircraft to have the aileron mass‑balance weight assembly modified/serviced per British Aerospace TNS W19 Issue 1 or inspected under a Secretary‑approved scheme by the specified maintenance deadlines (unless already done). It applies to owners/operators of all Heron models.\n\nThe measure responds to reported severe internal corrosion that could cause aileron flutter or handling failure; compliance imposes inspection/repair costs, parts/labour and aircraft downtime."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh114-48-aileron-mass-balance-weight-assembly","history":"/api/acts/ad-dh114-48-aileron-mass-balance-weight-assembly/history","analysis":"/api/acts/ad-dh114-48-aileron-mass-balance-weight-assembly/analysis","conflicts":"/api/acts/ad-dh114-48-aileron-mass-balance-weight-assembly/conflicts","importantCases":"/api/acts/ad-dh114-48-aileron-mass-balance-weight-assembly/important-cases","documents":"/api/acts/ad-dh114-48-aileron-mass-balance-weight-assembly/documents"}}