{"id":"F2006B08880","name":"AD/DH 104/37 - Aileron Mass Balance Weight Assembly","slug":"ad-dh-104-37-aileron-mass-balance-weight-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52351,"registerId":"commonwealth-F2006B08880-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 104/37 - 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)  DH 104 (Dove) Series Aeroplanes\n\n \n\nAD/DH 104/37 Aileron Mass Balance Weight Assembly 7/87 DM\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with British Aerospace TNS 245 Issue 1. Compliance:  1. Carry out the visual inspection within 14 days after 30 April 1987 and,\n\n2. If no corrosion is evident visually, carry out the radiographic inspection within 50 hours time in service after 30 April 1987 but no later than 31 July 1987.\n\n \n\nBackground: A case has been reported on a Heron aircraft 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\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to all DH 104 models and imposes inspection requirements specific to the aileron mass balance weight assembly. The instrument text contains no indication that the scope (affected aircraft or the component targeted) was altered from an earlier intent; it sets a single, focused scope as supplied."},"complexity_factors":["Short, specific procedural requirements (visual inspection then conditional radiography) reduce legal complexity.","Reference to an external technical document (British Aerospace TNS 245 Issue 1) increases operational complexity because detailed steps and remedies are delegated outside the AD text.","Technical nature of radiographic inspection requires specialist skills and equipment, adding logistical complexity for operators.","Tight compliance windows (14 days; 50 hours TIS; hard deadline 31 July 1987) increase scheduling pressure and implementation risk.","No corrective action details in the AD text itself — further action depends on the content of the referenced TNS or subsequent approvals."],"plain_english_summary":"This directive requires operators of DH.104 (Dove) series aeroplanes to inspect the aileron mass‑balance weight assembly following British Aerospace TNS 245 Issue 1: a visual check within 14 days after 30 April 1987, and—if no visible corrosion—a radiographic (X‑ray) inspection within 50 hours TIS or by 31 July 1987. Prompted by reported internal corrosion that could cause aileron flutter, the rule shifts costs and scheduling burden to owners/operators and may produce short‑term downtime and specialist radiography costs."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued in 1987 for a specific aircraft type and component. It has not expanded beyond its original purpose of mandating corrosion inspections on DH 104 Dove aileron balance weights."},"complexity_factors":["Single, specific mechanical component addressed","Only two compliance actions required (visual then conditional radiographic)","Simple temporal deadlines (14 days, 50 hours, 31 July 1987)","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single condition (if no corrosion evident) triggering second action","Total length: approximately 200 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 **DH 104 (Dove) series aeroplanes** to inspect the **aileron mass balance weight assembly** — a component that prevents dangerous vibration (flutter) in the aircraft's wing flaps (ailerons).\n\n**Who it affects:**\nAnyone who owns or operates any model of the DH 104 Dove aircraft.\n\n**What must be done:**\n- **Within 14 days after 30 April 1987:** Perform a visual inspection for corrosion\n- **If no corrosion found:** Perform an X-ray inspection (radiographic inspection) within 50 flight hours after 30 April 1987, but no later than 31 July 1987\n\n**Why it matters:**\nA similar aircraft (the Heron) experienced severe internal corrosion in this part. If the balance weight fails or falls off, the ailerons could flutter uncontrollably, causing catastrophic loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-104-37-aileron-mass-balance-weight-assembly","history":"/api/acts/ad-dh-104-37-aileron-mass-balance-weight-assembly/history","analysis":"/api/acts/ad-dh-104-37-aileron-mass-balance-weight-assembly/analysis","conflicts":"/api/acts/ad-dh-104-37-aileron-mass-balance-weight-assembly/conflicts","importantCases":"/api/acts/ad-dh-104-37-aileron-mass-balance-weight-assembly/important-cases","documents":"/api/acts/ad-dh-104-37-aileron-mass-balance-weight-assembly/documents"}}