{"id":"F2006B06623","name":"AD/ROBIN/25 - Aileron Mass Balance","slug":"ad-robin-25-aileron-mass-balance","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48489,"registerId":"commonwealth-F2006B06623-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ROBIN/25 - Aileron Mass Balance","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nRobin Aviation Series Aeroplanes\n\nAD/ROBIN/25 Aileron Mass Balance 12/95\n\nApplicability: HR 100-285, \\-250TR, and \\-289, all serial numbers.\n\nRequirement: Visually inspect the integrity of the fusion lines of all of the brazing of the aileron mass balance tubing attachments. Replace the assembly where any doubt may exist as to the integrity of the bond.\n\nNote: DGAC AD 79-178-IMP(A) refers.\n\nCompliance: Unless already accomplished in accordance with the DGAC AD within the last 100 hours time in service, within 50 hours time in service after the effective date of this Directive; thereafter at intervals not exceeding 100 hours time in service.\n\nThe effective date of this Directive is 9 November 1995.\n\nBackground: Loss of a control surface mass balance may cause flutter which could lead to loss of the aircraft.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive continues to target the same aircraft models and the same component risk described in the Background. Its mechanical requirements — visual inspection of brazed aileron mass-balance attachments and replacement where bond integrity is doubtful, with the same timing mechanism referencing prior DGAC compliance — are consistent with the stated safety purpose and do not indicate an expansion or narrowing of scope from that stated purpose (Applicability; Requirement; Compliance; Note; Background)."},"complexity_factors":["Narrow technical scope limited to specific aircraft types and parts (Applicability; Requirement).","Recurring inspection schedule with an initial conditional window tied to a prior DGAC action (Compliance; Note).","Subjective standard for replacement — \"where any doubt may exist\" — which creates variability in inspector judgement (Requirement).","Cross-reference to an external (DGAC) airworthiness directive, requiring operators to track compliance history against that standard (Note; Compliance).","Practical need for maintenance expertise to inspect brazed fusion lines (Requirement)."],"plain_english_summary":"This directive requires visual inspection of brazed aileron mass‑balance attachments on specified Robin HR 100 variants and replacement where the brazed joint’s integrity is in doubt. It applies to owners/operators and maintenance organisations. It aims to prevent loss of mass balance and flutter (risking structural failure). Inspections must occur within a 50‑hour initial window (unless previously done under the referenced DGAC AD) and recur every 100 hours, imposing recurring maintenance cost and inspector judgment calls."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical failure mode on specific aircraft. It has not expanded beyond its original technical scope."},"complexity_factors":["Very short document (under 200 words)","Only 3 defined applicability criteria (specific aircraft models)","Single technical requirement with one conditional exception (prior compliance under French DGAC AD)","No cross-references to other Australian legislation beyond the enabling regulations (CAR 1998 Part 39)","Simple temporal compliance structure (one-time + recurring interval)"],"plain_english_summary":"This is a **safety order** (called an \"Airworthiness Directive\") issued by Australia's aviation safety regulator for specific French-made Robin aeroplanes.\n\n**What it does:**\n- Requires owners/operators of certain Robin HR 100 series aircraft to **inspect the welded joints** on a small but critical part called the \"aileron mass balance\" — a weight attached to the wing's control surfaces that prevents dangerous vibrations (flutter) at high speeds.\n- If the inspection shows any doubt about whether the welds are sound, the entire assembly must be replaced.\n\n**Who it affects:**\n- Owners and operators of Robin HR 100-285, HR 100-250TR, and HR 100-289 aircraft (all serial numbers).\n- Maintenance engineers who work on these planes.\n\n**Why it matters:**\n- If the mass balance breaks off due to faulty welding, the wing can start vibrating uncontrollably (flutter), which can destroy the aircraft and kill everyone on board. This directive was issued after such failures were identified as a risk.\n\n**When to comply:**\n- First inspection within 50 flight hours after 9 November 1995 (unless already done under a French directive within the previous 100 flight hours).\n- Then re-inspect every 100 flight hours thereafter."}},"importantCases":[],"_links":{"self":"/api/acts/ad-robin-25-aileron-mass-balance","history":"/api/acts/ad-robin-25-aileron-mass-balance/history","analysis":"/api/acts/ad-robin-25-aileron-mass-balance/analysis","conflicts":"/api/acts/ad-robin-25-aileron-mass-balance/conflicts","importantCases":"/api/acts/ad-robin-25-aileron-mass-balance/important-cases","documents":"/api/acts/ad-robin-25-aileron-mass-balance/documents"}}